US20020188053A1 - Composition and process for the sealing of microcups in roll-to-roll display manufacturing - Google Patents

Composition and process for the sealing of microcups in roll-to-roll display manufacturing Download PDF

Info

Publication number
US20020188053A1
US20020188053A1 US09/874,391 US87439101A US2002188053A1 US 20020188053 A1 US20020188053 A1 US 20020188053A1 US 87439101 A US87439101 A US 87439101A US 2002188053 A1 US2002188053 A1 US 2002188053A1
Authority
US
United States
Prior art keywords
poly
styrene
composition
methylstyrene
solvent
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US09/874,391
Inventor
HongMei Zang
Xiaojia Wang
Rong-Chang Liang
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
E Ink California LLC
Original Assignee
Sipix Imaging Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sipix Imaging Inc filed Critical Sipix Imaging Inc
Priority to US09/874,391 priority Critical patent/US20020188053A1/en
Priority to TW090123324A priority patent/TWI301211B/en
Assigned to SIPIX IMAGING, INC. reassignment SIPIX IMAGING, INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: LIANG, RONG-CHANG, WANG, XIANJIA, ZANG, HONGMEI
Priority to CNB011364483A priority patent/CN1237140C/en
Priority to CA002448440A priority patent/CA2448440A1/en
Priority to KR1020037015909A priority patent/KR100859305B1/en
Priority to PCT/US2002/017632 priority patent/WO2002098977A1/en
Priority to MXPA03011144A priority patent/MXPA03011144A/en
Priority to EP02737371A priority patent/EP1401953A1/en
Priority to JP2003502091A priority patent/JP4322663B2/en
Priority to US10/222,297 priority patent/US7005468B2/en
Priority to US10/222,454 priority patent/US7144942B2/en
Priority to US10/310,681 priority patent/US7205355B2/en
Publication of US20020188053A1 publication Critical patent/US20020188053A1/en
Priority to US11/582,844 priority patent/US8361356B2/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • CCHEMISTRY; METALLURGY
    • C09DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09JADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J153/00Adhesives based on block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Adhesives based on derivatives of such polymers
    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/165Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on translational movement of particles in a fluid under the influence of an applied field
    • G02F1/166Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect
    • G02F1/167Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect by electrophoresis
    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/1341Filling or closing of cells
    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/165Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on translational movement of particles in a fluid under the influence of an applied field
    • G02F1/1675Constructional details
    • G02F1/1679Gaskets; Spacers; Sealing of cells; Filling or closing of cells
    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/133377Cells with plural compartments or having plurality of liquid crystal microcells partitioned by walls, e.g. one microcell per pixel
    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/1334Constructional arrangements; Manufacturing methods based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/1347Arrangement of liquid crystal layers or cells in which the final condition of one light beam is achieved by the addition of the effects of two or more layers or cells
    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/1347Arrangement of liquid crystal layers or cells in which the final condition of one light beam is achieved by the addition of the effects of two or more layers or cells
    • G02F1/13475Arrangement of liquid crystal layers or cells in which the final condition of one light beam is achieved by the addition of the effects of two or more layers or cells in which at least one liquid crystal cell or layer is doped with a pleochroic dye, e.g. GH-LC cell

Definitions

  • the electrophoretic display is a non-emissive device based on the electrophoresis phenomenon influencing charged pigment particles suspended in a solvent.
  • An EPD typically comprises a pair of opposed, spaced-apart plate-like electrodes, with spacers predetermining a certain distance between the electrodes.
  • One of the electrodes is typically transparent.
  • a suspension composed of a colored solvent and suspended charged pigment particles is enclosed between the two plates.
  • the pigment particles migrate by attraction to the plate of polarity opposite that of the pigment particles.
  • the color showing at the transparent plate may be determined by selectively charging the plates to be either the color of the solvent or the color of the pigment particles. Reversal of plate polarity will cause the particles to migrate back to the opposite plate, thereby reversing the color.
  • Intermediate color density (or shades of gray) due to intermediate pigment density at the transparent plate may be obtained by controlling the voltage or charging time.
  • EPD electrophoretic display
  • partitions were proposed between the two electrodes for dividing the space into smaller cells. See, e.g., M. A Hopper and V. Novotny, IEEE Trans. Electr. Dev., Vol ED 26, No. 8, pp 1148-1152 (1979).
  • partition-type EPD some difficulties are encountered in the formation of the partitions and the process of enclosing the suspension. Furthermore, it is also difficult to keep different colors of suspensions separate from each other in the partition-type EPD.
  • microencapsulated EPDs have a substantially two dimensional arrangement of microcapsules each containing an electrophoretic composition comprising a dielectric fluid with charged pigment particles suspended therein and the particles visually contrast with the dielectric solvent.
  • the microcapsules can be formed by interfacial polymerization, in-situ polymerization or other known methods such as in-liquid curing or simple/complex coacervation.
  • microcapsules after their formation, may be injected into a cell housing two spaced-apart electrodes, or they may be “printed” into or coated on a transparent conductor film.
  • the microcapsules may also be immobilized within a transparent matrix or binder that is itself sandwiched between the two electrodes.
  • the EPDs prepared by these prior art processes in particular the microencapsulation process, as disclosed in U.S. Pat. Nos. 5,930,026, 5,961,804, and 6,017,584, have several shortcomings.
  • the EPDs manufactured by the microencapsulation process suffer from sensitivity to environmental changes (in particular sensitivity to moisture and temperature) due to the wall chemistry of the microcapsules.
  • the EPDs based on the microcapsules have poor scratch resistance due to the thin wall and large particle size of the microcapsules.
  • microcapsules are embedded in a large quantity of polymer matrix which results in a slow response time due to the large distance between the two electrodes and a low contrast ratio due to the low payload of pigment particles. It is also difficult to increase the surface charge density on the pigment particles because charge-controlling agents tend to diffuse to the water/oil interface during the microencapsulation process. The low charge density or zeta potential of the pigment particles in the microcapsules also results in a slow response rate. Furthermore, because of the large particle size and broad size distribution of the microcapsules, the prior art EPD of this type has poor resolution and addressability for color applications.
  • the cells of the improved EPD are formed from a plurality of microcups which are formed integrally with one another as portions of a structured two-dimensional array assembly. Each microcup of the array assembly is filled with a suspension or dispersion of charged pigment particles in a dielectric solvent, and sealed to form an electrophoretic cell.
  • the substrate web upon which the microcups are formed includes a display addressing array comprising preformed conductor film, such as ITO conductor lines.
  • the conductor film (ITO lines) is coated with a radiation curable polymer precursor layer.
  • the film and precursor layer are then exposed imagewise to radiation to form the microcup wall structure.
  • the precursor material is removed from the unexposed areas, leaving the cured microcup walls bonded to the conductor film/support web.
  • the imagewise exposure may be accomplished by UV or other forms of radiation through a photomask to produce an image or predetermined pattern of exposure of the radiation curable material coated on the conductor film.
  • the mask may be positioned and aligned with respect to the conductor film, i.e., ITO lines, so that the transparent mask portions align with the spaces between ITO lines, and the opaque mask portions align with the ITO material (intended for microcup cell floor areas).
  • the conductor film i.e., ITO lines
  • the microcup array may be prepared by a process including embossing a thermoplastic or thermoset precursor layer coated on a conductor film with a pre-patterned male mold, followed by releasing the mold.
  • the precursor layer may be hardened by radiation, cooling, solvent evaporation, or other means during or after the embossing step.
  • Solvent-resistant, thermomechanically stable microcups having a wide range of size, shape, pattern and opening ratio can be prepared by either one of the aforesaid methods.
  • the manufacture of a monochrome EPD from a microcup assembly involves filling the microcups with a single pigment suspension composition, sealing the microcups, and finally laminating the sealed array of microcups with a second conductor film pre-coated with an adhesive layer.
  • a color EPD its preparation from a microcup assembly involves sequential selective opening and filling of predetermined microcup subsets.
  • the process includes laminating or coating the preformed microcups with a layer of positively working photoresist, selectively opening a certain number of the microcups by imagewise exposing the positive photoresist, followed by developing the resist, filling the opened cups with a colored electrophoretic fluid, and sealing the filled microcups by a sealing process. These steps may be repeated to create sealed microcups filled with electrophoretic fluids of different colors.
  • the array may be filled with different colored compositions in predetermined areas to form a color EPD.
  • Various known pigments and dyes provide a wide range of color options for both solvent phase and suspended particles.
  • Known fluid application and filling mechanisms may be employed.
  • the sealing of the microcups after they are filled with a dispersion of charged pigment particles in a dielectric fluid can be accomplished by overcoating the electrophoretic fluid with a solution containing a thermoplastic or thermoset precursor.
  • a sealing composition that is immiscible with the electrophoretic fluid and preferably has a specific gravity lower than the dielectric fluid.
  • the sealing is then accomplished by hardening the precursor by solvent evaporation, interfacial reaction, moisture, heat, radiation, or a combination of curing mechanisms.
  • the sealing can be accomplished by dispersing a thermoplastic or thermoset precursor in the electrophoretic fluid before the filling step.
  • thermoplastic or thermoset precursor is immiscible with the dielectric solvent and has a specific gravity lower than that of the solvent and the pigment particles.
  • the thermoplastic or thermoset precursor phase separates from the electrophoretic fluid and forms a supernatant layer at the top of the fluid.
  • the sealing of the microcups is then conveniently accomplished by hardening the precursor layer by solvent evaporation, interfacial reaction, moisture, heat, or radiation. UV radiation is the preferred method to seal the microcups, although a combination of two or more curing mechanisms as described above may be used to increase the throughput of sealing.
  • the improved EPDs may also be manufactured by a synchronized roll-to-roll photolithographic exposure process as described in the co-pending application, U.S. Ser. No. 09/784,972, filed on Feb. 25, 2001.
  • a photomask may be synchronized in motion with the support web using mechanisms such as coupling or feedback circuitry or common drives to maintain the coordinated motion (i.e., to move at the same speed).
  • the web moves into a development area where the unexposed material is removed to form the microcup wall structure.
  • the microcups and ITO lines are preferably of selected size and coordinately aligned with the photomask, so that each completed display cell (i.e., filled and sealed microcup) may be discretely addressed and controlled by the display driver.
  • the ITO lines may be pre-formed by either a wet or a dry etching process on the substrate web.
  • the synchronized roll-to-roll exposure photolithographic process also enables continuous web processes of selective opening, filling and sealing of pre-selected subsets of the microcup array.
  • the microcup array may be temporarily sealed by laminating or coating with a positive-acting photoresist composition, imagewise exposing through a corresponding photomask, and developing the exposed area with a developer to selectively open a desired subset of the microcups.
  • a positive-acting photoresist composition imagewise exposing through a corresponding photomask
  • developing the exposed area with a developer to selectively open a desired subset of the microcups.
  • developer in this context refers to a suitable known means for selectively removing the exposed photoresist, while leaving the unexposed photoresist in place.
  • the array may be sequentially filled with several different color compositions (typically three primary colors) in a pre-determined cell pattern.
  • the imagewise exposure process may employ a positively working photoresist top laminate or coating which initially seals the empty microcups.
  • the microcups are then exposed through a mask (e.g., a loop photomask in the described roll-to-roll process) so that only a first selected subset of microcups are exposed.
  • Development with a developer removes the exposed photoresist and thus opens the first microcup subset to permit filling with a selected color pigment dispersion composition, and sealing by one of the methods described herein.
  • the exposure and development process is repeated to expose and open a second selected microcup subset, for filling with a second pigment dispersion composition, with subsequent sealing. Finally, the remaining photoresist is removed and the third subset of microcups is filled and sealed.
  • Liquid crystal displays may also be prepared by the method as described above when the electrophoretic fluid is replaced by a suitable liquid crystal composition having the ordinary refractive index matched to that of the isotropic cup material.
  • the liquid crystal in the microcups In the “on” state, the liquid crystal in the microcups is aligned to the field direction and is transparent. In the “off” state, the liquid crystal is not aligned and scatters light.
  • the diameter of the microcups is typically in the range of 0.5-10 microns.
  • the roll-to-roll process may be employed to carry out a sequence of processes on a single continuous web, by carrying and guiding the web to a plurality of process stations in sequence.
  • the microcups may be formed, filled or coated, developed, sealed, and laminated in a continuous sequence.
  • the synchronized roll-to-roll process may be adapted to the preparation of a wide range of structures or discrete patterns for electronic devices formable upon a support web substrate, e.g., patterned conductor films, flexible circuit boards and the like.
  • a pre-patterned photomask is prepared which includes a plurality of photomask portions corresponding to structural elements of the subject device. Each such photomask portion may have a pre-selected area of transparency or opacity to radiation so as to form an image of such a structural element upon the correspondingly aligned portion of the web during exposure.
  • the method may be used for selective curing of structural material, or may be used to expose positively or negatively acting photoresist material during manufacturing processes.
  • these multiple-step processes may be carried out roll-to-roll continuously or semi-continuously, they are suitable for high volume and low cost production. These processes are also efficient and inexpensive as compared to other processes for manufacturing display products.
  • the improved EPD involving microcups is not sensitive to environment, such as humidity and temperature.
  • the display is thin, flexible, durable, easy-to-handle, and format-flexible. Since the EPD comprises cells of favorable aspect ratio and well-defined shape and size, the bi-stable reflective display has excellent color addressability, high contrast ratio and color saturation, fast switching rate and response time.
  • Sealing of the microcups by a continuous web process is one of the most critical steps in the roll-to-roll manufacturing of the improved EPDs.
  • the sealing layer In order to prepare a high quality display, the sealing layer must have at least the following characteristics: (1) free of defects such as entrapped air bubble, pin holes, cracking or leaking, etc; (2) good film integrity and barrier properties against the display fluid such as dielectric fluids for EPDs; and (3) good coating and adhesion properties. Since most of the dielectric solvents used in EPDs are of low surface tension and low viscosity, it has been a major challenge to achieve a seamless, defect-free sealing with good adhesion properties for the microcups.
  • thermoplastic elastomers having good compatibility with the microcups and good barrier properties against the display fluid are particularly useful.
  • useful thermoplastic elastomers include di-block, tri-block or multi-block copolymers represented by the formulas ABA or (AB)n in which A is styrene, ⁇ -methylstyrene, ethylene, propylene or norbonene; B is butadiene, isoprene, ethylene, proplyene, butylene, dimethoylsiloxane or propylene sulfide; and A and B cannot be the same in the formula.
  • the number, n is ⁇ 1, preferably 1-10.
  • copolymers include poly(styrene-b-butadiene), poly(styrene-b-butadiene-b-styrene), poly(styrene-b-isoprene-b-styrene), poly(styrene-b-ethylene/butylene-b-styrene), poly(styrene-b-dimethylsiloxane-b-styrene), poly(( ⁇ -methylstyrene-b-isoprene), poly( ⁇ -methylstyrene-b-isoprene-b- ⁇ -methylstyrene), poly( ⁇ -methylstyrene-b-propylene sulfide-b- ⁇ -methylstyrne), and poly( ⁇ -methylstyrene-b-dimethylsiloxane-b- ⁇ -methylstyrene).
  • thermoplastic elastomers A review of the preparation of the thermoplastic elastomers can be found in N. R. Legge, G. Holden, and H. E. Schroeder ed., “Thermoplastic Elastomers”, Hanser Publisher (1987).
  • Commercially available styrene block copolymers such as Kraton D and G series from Shell Chemical Company are particularly useful.
  • Crystalline rubbers such as poly(ethylene-co-propylene-co-5-methylene-2-norbomene) or EPDM (ethylene-propylene-diene terpolymer) rubbers and their grafted copolymers have also been found very useful.
  • the hard block of the thermoplastic elastomers phase separates during or after the drying of the sealing overcoat and serves as the physical crosslinker of the soft continuous phase.
  • the sealing composition of the present invention significantly enhances the modulus and film integrity of the sealing layer throughout the coating and drying processes.
  • Thermoplastic elastomers having low critical surface tension (lower than 40 dyne/cm) and high modulus or Shore A hardness (higher than 60) have been found useful probably because of their favorable wetting property and film integrity over the display fluid.
  • thermoplastic elastomer is dissolved in a solvent or solvent mixture which is immiscible with the display fluid in the microcups and exhibits a specific gravity less than that of the display fluid.
  • Low surface tension solvents are preferred for the overcoating composition because of their better wetting properties over the microcup surface and the electrophoretic fluid.
  • Solvents or solvent mixtures having a surface tension lower than 35 dyne/cm are preferred. A surface tension lower than 30 dyne/cm is more preferred.
  • Suitable solvents include alkanes (preferably C 6-12 alkanes such as heptane, octane or Isopar solvents from Exxon Chemical Company, nonane, decane and their isomers), cycloalkanes (preferably C 6-12 cycloalkanes such as cyclohexane, decalin and the like), alkylbenzenes (preferably mono- or di-C 1-6 alkyl benzenes such as toluene, xylene and the like), alkyl esters (preferably C 2-5 alkyl esters such as ethyl acetate, isobutyl acetate and the like) and C 3-5 alkyl alcohols (such as isopropanol and the like and their isomers.
  • alkanes preferably C 6-12 alkanes such as heptane, octane or Isopar solvents from Exxon Chemical Company, nonane, decane and their is
  • the composition of the present invention enables the continuous sealing of wider microcups, particularly those having a width greater than 100 microns. Wider microcups are preferred in some applications because of their higher microcup opening-to-wall ratio and better display contrast ratio.
  • the sealing composition of the present invention enables the formation of a sealing layer less than 3 microns thick which is typically difficult to achieve by using traditional sealing compositions. The thinner sealing layer shortens the distance between the top and bottom electrodes and results in a faster switching rate.
  • Co-solvents and wetting agents may also be included in the composition to improve the adhesion of the sealant to the microcups and provides a wider coating process latitude.
  • Other ingredients such as crosslinking agents, vulcanizers, multifunctional monomers or oligomers, and high Tg polymers that are miscible with one of the blocks of the thermoplastic elastomer are also highly useful to enhance the physicomechanical properties of the sealing layer during or after the overcoating process.
  • the sealed microcups may be post treated by UV radiation or thermal baking to further improve the barrier properties.
  • the adhesion of the sealing layer to the microcups may also be improved by the post-curing reaction, probably due to the formation of an interpenetration network at the microcup-sealing sealing layer inter-phase.
  • FIG. 1 is a schematic cross-section of an EPD, showing three microcup cells in a neutral condition.
  • FIG. 2 is a schematic cross-section of the EPD of FIG. 1, but with two of the cells charged, to cause the pigment to migrate to one plate.
  • FIGS. 3 A- 3 C shows the contours of an exemplary microcup array, FIG. 3A showing a perspective view, FIG. 3B showing a plan view, and FIG. 3C showing an elevation view, the vertical scale being exaggerated for clarity.
  • FIGS. 4A and 4B show the basic processing steps for preparing the microcups involving imagewise photolithographic exposure through a photomask (“top exposure”) of the conductor film coated with a thermoset precursor, to UV radiation.
  • FIGS. 5A and 5B show alternative processing steps for preparing the microcups involving imagewise photolithography combining the top exposure and bottom exposure principles, whereby the walls are cured in one lateral direction by top photomask exposure and in the perpendicular lateral direction by bottom exposure through the opaque base conductor film (“combined exposure”).
  • FIGS. 6 A- 6 D are a sequence of cross sections of a microcup array, illustrating the steps of assembling a monochrome display.
  • microcup refers to the cup-like indentations, which may be created by methods such as micro-embossing or imagewise exposure as described in the co-pending patent applications identified above.
  • the plural form “microcups” in a collective context may in general refer to the microcup assembly comprising a plurality of such microcups integrally formed or joined to make a structured two-dimensional microcup array.
  • cell in the context of the present invention, is intended to mean the single unit formed from a sealed microcup.
  • the cells are filled with charged pigment particles dispersed in a solvent or solvent mixture.
  • microcups or cells when describing the microcups or cells, is intended to indicate that the microcup or cell has a definite shape, size, pattern and aspect ratio which are predetermined according to the specific parameters of the manufacturing process.
  • the term “aspect ratio” is a commonly known term in the art and is the depth to width ratio or the depth to diameter ratio of the microcup opening.
  • imagewise exposure means exposure of radiation-curable material or photoresist composition to radiation, such as UV, using one of the methods of the invention, whereby the portions of the material so exposed are controlled to form a pattern or “image” corresponding to the structure of the microcups, e.g., the exposure is restricted to the portions of the material corresponding to the microcup walls, leaving the microcup floor portion unexposed.
  • imagewise exposure means exposure on the portions of material corresponding to the cup opening, leaving the microcup walls unexposed.
  • the pattern or image may be formed by such methods as exposure through a photomask, or alternatively by controlled particle beam exposure, and the like.
  • FIGS. 1 and 2 are schematic cross-section views of an exemplary microcup array assembly embodiment, simplified for clarity, showing a microcup array assembly ( 10 ) of three microcup cells ( 12 a, b, and c ).
  • each cell ( 12 ) of array ( 10 ) comprises two electrode plates ( 11 , 13 ), at least one of which is transparent ( 11 ), such as an ITO electrode, the electrodes ( 11 ) and ( 13 ) bounding two opposite faces of the cell ( 12 ).
  • the microcup cell array assembly ( 10 ) comprises a plurality of cells which are disposed adjacent to one another within a plane to form a layer of cells ( 12 ) enclosed between the two electrodes layers ( 11 ) and ( 13 ).
  • Three exemplary cells ( 12 a ), ( 12 b ), and ( 12 c ) are shown, bounded by their respective electrode plates ( 11 a ), ( 11 b ), and ( 11 c ) (transparent) and ( 13 a ), ( 13 b ), and ( 13 c ) (back plates), it being understood that a large number of such cells are preferably arrayed two-dimensionally (to the right/left and in/out of the plane in FIG.
  • FIG. 1 shows an example in which each cell ( 12 ) is bounded by separate electrode plates ( 11 ) and ( 13 ) having the width of a single cell.
  • the cells are of well-defined shape and size and are filled with a colored dielectric solvent ( 14 ) in which charged pigment particles ( 15 ) are suspended and dispersed.
  • the cells ( 12 ) may be each filled with the same composition of pigment and solvent (e.g., in a monochrome display) or may be filled with different compositions of pigment and solvent (e.g., in a color display).
  • FIG. 1 shows three different color combinations as indicated by the different hatch pattern in each cell ( 12 a ), ( 12 b ), and ( 12 c ), the solvents being designated ( 14 a ), ( 14 b ), and ( 14 c ) respectively, and the pigment particles being designated ( 15 a ), ( 15 b ), and ( 15 c ) respectively.
  • the microcup cells ( 12 ) each comprise enclosing walls ( 16 ) bounding the cells on the sides (within the plane of array ( 10 )) and floor ( 17 ) bounding the cell on one face, in this example the face adjacent to electrode ( 13 ).
  • each cell On the opposite face (adjacent electrode ( 11 )) each cell comprises sealing cap portion ( 18 ). Where the sealing cap portion is adjacent to the transparent electrode ( 11 ) (as in FIG. 1), the sealing cap ( 18 ) comprises a transparent composition.
  • the floor ( 17 ) and the sealing cap ( 18 ) are shown as separate cell portions distinct from adjacent electrodes ( 13 ) and ( 11 ) respectively, alternative embodiments of the microcup array ( 10 ) of the invention may comprise an integral floor/electrode structure or an integral sealing cap/electrode structure.
  • FIG. 2 is a schematic cross-section of the EPD of FIG. 1, but with two of the cells charged ( 12 a and 12 c ), to cause the pigment to migrate to one plate.
  • the charged particles ( 15 ) migrate (i.e., toward electrode ( 11 ) or ( 13 ) depending on the charge of the particle and electrode), such that either the color of the pigment particle ( 15 ) or the color of the solvent ( 14 ) is seen through the transparent conductor film ( 11 ).
  • At least one of the two conductors ( 11 ) or ( 13 ) is patterned (separately addressable portions ) to permit a selective electric field to be established with respect to either each cell or with respect to a pre-defined group of cells (e.g., to form a pixel).
  • FIGS. 3 A- 3 C shows the contours of an exemplary portion of a microcup array, FIG. 3A showing a perspective view, FIG. 3B showing a plan view, and FIG. 3C showing an elevation view, the vertical scale being exaggerated for clarity.
  • the opening area of each individual microcup may preferably be in the range of about 10 2 to about 5 ⁇ 10 5 ⁇ m 2 , more preferably from about 10 3 to about 5 ⁇ 10 4 ⁇ m 2 .
  • the width w of the microcup ( 12 ) may vary over a wide range, and is selectable to suit the desired final display characteristics.
  • the width w of the microcup openings preferably is in the range of from about 15 to about 450 ⁇ m, and more preferably from about 25 to about 300 ⁇ m from edge to edge of the openings.
  • Each microcup may form a small segment of a pixel of the final display, or may be a full pixel.
  • the wall thickness t relative to the cup width w may vary over a large range, and is selectable to suit the desired final display characteristics.
  • the microcup wall thickness is typically from about 0.01 to about 1 times the microcup width, and more preferably about 0.05 to about 0.25 times the microcup width.
  • the opening-to-total area ratio is preferably in the range of about 0.1 to about 0.98, more preferably from about 0.3 to about 0.95.
  • the microcup wall height h (which defines the cup depth) is shown exaggerated beyond its typical proportional dimensions for clarity.
  • the height of the microcups is typically in the range of about 5 to about 100 microns ( ⁇ ms), preferably from about 10 to about 50 microns.
  • the height is typically in the range of about 1 to 10 microns and more preferably from about 2 to 5 microns.
  • microcup array assembly For simplicity and clarity, a square microcup arranged in a linear two-dimensional array assembly is assumed in the description herein of the microcup array assembly of the invention.
  • the microcup need not be square, it may be rectangular, circular, or a more complex shape if desired.
  • the microcups may be hexagonal and arranged in a hexagonal close-packed array, or alternatively, triangular cups may be oriented to form hexagonal sub-arrays, which in turn are arranged in a hexagonal close-packed array.
  • the microcups can be of any shape, and their sizes, pattern and shapes may vary throughout the display. This may be advantageous in the color EPD.
  • microcups having a mixture of different shapes and sizes may be produced.
  • microcups filled with a dispersion of the red color may have a different shape or size from the green microcups or the blue microcups.
  • a pixel may consist of different numbers of microcups of different colors. For example, a pixel may consist of a number of small green microcups, a number of large red microcups, and a number of small blue microcups. It is not necessary to have the same shape and number for the three colors.
  • the openings of the microcups may be round, square, rectangular, hexagonal, or any other shapes.
  • the partition area between the openings is preferably kept small in order to achieve a high color saturation and contrast while maintaining desirable mechanical properties. Consequently the honeycomb-shaped opening is preferred over, for example, the circular opening.
  • the microcups may be prepared by microembossing or by photolithography.
  • the male mold may be prepared by any appropriate method, such as a diamond turn process or a photoresist process followed by either etching or electroplating.
  • a master template for the male mold may be manufactured by any appropriate method, such as electroplating. With electroplating, a glass base is sputtered with a thin layer (typically 3000 ⁇ ) of a seed metal such as chrome inconel. It is then coated with a layer of photoresist and exposed to UV. A mask is placed between the UV and the layer of photoresist. The exposed areas of the photoresist become hardened. The unexposed areas are then removed by washing them with an appropriate solvent. The remaining hardened photoresist is dried and sputtered again with a thin layer of seed metal.
  • the master is then ready for electroforming.
  • a typical material used for electroforming is nickel cobalt.
  • the master can be made of nickel by electroforming or electroless nickel deposition as described in “Continuous manufacturing of thin cover sheet optical media”, SPIE Proc. Vol. 1663, pp. 324 (1992).
  • the floor of the mold is typically between about 50 to 400 microns.
  • the master can also be made using other microengineering techniques including e-beam writing, dry etching, chemical etching, laser writing or laser interference as described in “Replication techniques for micro-optics”, SPIE Proc. Vol. 3099, pp. 76-82 (1997).
  • the mold can be made by photomachining using plastics, ceramics or metals.
  • the male mold thus prepared typically has protrusions between about 1 to 500 microns, preferably between about 2 to 100 microns, and most preferred about 4 to 50 microns.
  • the male mold may be in the form of a belt, a roller, or a sheet. For continuous manufacturing, the belt type of mold is preferred.
  • Micro-cups may be formed either in a batchwise process or in a continuous roll-to-roll process as disclosed in the co-pending application, U.S. Ser. No. 09/784,972, filed on Feb. 25, 2001.
  • the latter offers a continuous, low cost, high throughput manufacturing technology for production of compartments for use in electrophoretic or LCDs.
  • the mold Prior to applying a UV curable resin composition, the mold may be treated with a mold release to aid in the demolding process.
  • the UV curable resin may be degassed prior to dispensing and may optionally contain a solvent. The solvent, if present, readily evaporates.
  • the UV curable resin is dispensed by any appropriate means such as, coating, dipping, pouring and the like, over the male mold.
  • the dispenser may be moving or stationary.
  • a conductor film is overlaid the UV curable resin.
  • suitable conductor film include transparent conductor ITO on plastic substrates such as polyethylene terephthalate, polyethylene naphthate, polyaramid, polyimide, polycycloolefin, polysulfone, epoxy and their composites.
  • Pressure may be applied, if necessary, to ensure proper bonding between the resin and the plastic and to control the thickness of the floor of the micro-cups. The pressure may be applied using a laminating roller, vacuum molding, press device or any other like means.
  • the male mold is metallic and opaque, the plastic substrate is typically transparent to the actinic radiation used to cure the resin. Conversely, the male mold can be transparent and the plastic substrate can be opaque to the actinic radiation. To obtain good transfer of the molded features onto the transfer sheet, the conductor film needs to have good adhesion to the UV curable resin which should have a good release property against the mold surface.
  • the microcup array ( 40 ) may be prepared by exposure of a radiation curable material ( 41 a ) coated by known methods onto a conductor electrode film ( 42 ) to UV light (or alternatively other forms of radiation, electron beams and the like) through a mask ( 46 ) to form walls ( 41 b ) corresponding to the image projected through the mask ( 46 ).
  • the base conductor film ( 42 ) is preferably mounted on a supportive substrate base web ( 43 ), which may comprise a plastic material.
  • the dark squares ( 44 ) represent the opaque area and the space between the dark squares represents the transparent area ( 45 ) of the mask ( 46 ).
  • the UV radiates through the transparent area ( 45 ) onto the radiation curable material ( 41 a ).
  • the exposure is preferably directly onto the radiation curable material ( 41 a ), i.e., the UV does not pass through the substrate ( 43 ) or base conductor ( 42 ) (top exposure). For this reason, neither the substrate ( 43 ) nor the conductor ( 42 ) needs to be transparent to the UV or other radiation wavelengths employed.
  • the exposed areas ( 41 b ) become hardened and the unexposed areas (protected by the opaque area ( 44 ) of the mask ( 46 ) are then removed by an appropriate solvent or developer to form the microcups ( 47 ).
  • the solvent or developer is selected from those commonly used for dissolving or reducing the viscosity of radiation curable materials such as methylethylketone (MEK), toluene, acetone, isopropanol or the like.
  • MEK methylethylketone
  • the preparation of the microcups may be similarly accomplished by placing a photomask underneath the conductor film/substrate support web and in this case the UV light radiates through the photomask from the bottom and the substrate needs to be transparent to radiation.
  • FIGS. 5A and 5B Still another alternative method for the preparation of the microcup array of the invention by imagewise exposure is illustrated in FIGS. 5A and 5B.
  • the conductor lines can be used as the photomask for the exposure from the bottom.
  • Durable microcup walls are formed by additional exposure from the top through a second photomask having opaque lines perpendicular to the conductor lines.
  • FIG. 5A illustrates the use of both the top and bottom exposure principals to produce the microcup array ( 50 ) of the invention.
  • the base conductor film ( 52 ) is opaque and line-patterned.
  • the radiation curable material ( 51 a ) which is coated on the base conductor ( 52 ) and substrate ( 53 ), is exposed from the bottom through the conductor line pattern ( 52 ) which serves as the first photomask.
  • a second exposure is performed from the “top” side through the second photomask ( 56 ) having a line pattern perpendicular to the conductor lines ( 52 ).
  • the spaces ( 55 ) between the lines ( 54 ) are substantially transparent to the UV light.
  • the wall material ( 51 b ) is cured from the bottom up in one lateral orientation, and cured from the top down in the perpendicular direction, joining to form an integral microcup ( 57 ).
  • the unexposed area is then removed by a solvent or developer as described above to reveal the microcups ( 57 ).
  • the novel sealing overcoat composition comprises the following ingredients:
  • thermoplastic elastomers having good compatibility with the microcups and good barrier properties against the display fluid are particularly useful.
  • useful thermoplastic elastomers include ABA, and (AB)n type of di-block, tri-block, and multi-block copolymers wherein A is styrene, ⁇ -methylstyrene, ethylene, propylene or norbonene; B is butadiene, isoprene, ethylene, propylene, butylene, dimethylsiloxane or propylene sulfide; and A and B cannot be the same in the formula.
  • the number, n, is ⁇ 1, preferably 1-10.
  • di-block or tri-block copolymers of styrene or ox-methylstyrene such as SB (poly(styrene-b-butadiene)), SBS (poly(styrene-b-butadiene-b-styrene)), SIS (poly(styrene-b-isoprene-b-styrene)), SEBS (poly(styrene-b-ethylene/butylenes-b-stylene)) poly(styrene-b-dimethylsiloxane-b-styrene), poly(( ⁇ -methylstyrene-b-isoprene), poly( ⁇ -methylstyrene-b-isoprene-b- ⁇ -methylstyrene), poly( ⁇ -methylstyrene-b-propylene sulfide-b- ⁇ -methylstyrene), poly( ⁇ -methylstyren
  • thermoplastic elastomers A review of the preparation of the thermoplastic elastomers can be found in N. R. Legge, G. Holden, and H. E. Schroeder ed., “Thermoplastic Elastomers”, Hanser Publisher (1987).
  • Commercially available styrene block copolymers such as Kraton D and G series (from Kraton Polymer, Houston, Tex.) are particularly useful.
  • Crystalline rubbers such as poly(ethylene-co-propylene-co-5-methylene-2-norbomene) or EPDM (ethylene-propylene-diene terpolymer) rubbers such as Vistalon 6505 (from Exxon Mobil, Houston, Tex.) and their grafted copolymers have also been found very useful.
  • the hard block of the thermoplastic elastomers phase separates during or after the drying of the sealing overcoat and serves as the physical crosslinker of the soft continuous phase.
  • the sealing composition of the present invention significantly enhances the modulus and film integrity of the sealing layer throughout the coating and drying processes of the sealing layer.
  • Thermoplastic elastomers having low critical surface tension (lower than 40 dyne/cm) and high modulus or Shore A hardness (higher than 60) have been found useful probably because of their favorable wetting property and film integrity over the display fluid.
  • thermoplastic elastomer is dissolved in a solvent or solvent mixture which is immiscible with the display fluid in the microcups and exhibits a specific gravity less than that of the display fluid.
  • Low surface tension solvents are preferred for the overcoating composition because of their better wetting properties over the microcup walls and the electrophoretic fluid.
  • Solvents or solvent mixtures having a surface tension lower than 35 dyne/cm are preferred. A surface tension of lower than 30 dyne/cm is more preferred.
  • Suitable solvents include alkanes (preferably C 6-12 alkanes such as heptane, octane or Isopar solvents from Exxon Chemical Company, nonane, decane and their isomers), cycloalkanes (preferably C 6-12 cycloalkanes such as cyclohexane and decalin and the like), alkylbezenes (preferably mono- or
  • di-C 1-6 alkyl benzenes such as toluene, xylene and the like
  • alkyl esters preferably C 2-5 alkyl esters such as ethyl acetate, isobutyl acetate and the like
  • C 3-5 alkyl alcohols such as isopropanol and the like and their isomers. Mixtures of alkylbenzene and alkane are particularly useful.
  • Wetting agents such as the FC surfactants from 3M Company, Zonyl fluorosurfactants from DuPont, fluoroacrylates, fluoromethacrylates, fluoro-substituted long chain alcohols, perfluoro-substituted long chain carboxylic acids and their derivatives, and Silwet silicone surfactants from OSi, Greenwich, Conn.
  • FC surfactants from 3M Company, Zonyl fluorosurfactants from DuPont, fluoroacrylates, fluoromethacrylates, fluoro-substituted long chain alcohols, perfluoro-substituted long chain carboxylic acids and their derivatives, and Silwet silicone surfactants from OSi, Greenwich, Conn.
  • crosslinking agents e.g., bisazides such as 4,4′-diazidodiphenylmethane and 2,6-di-(4′-azidobenzal)-4-methylcyclohexanone
  • vulcanizers e.g., 2-benzothiazolyl disulfide and tetramethylthiuram disulfide
  • multifunctional monomers or oligomers e.g., hexanediol, diacrylates, trimethylolpropane, triacrylate, divinylbenzene, diallylphthalene
  • thermal initiators e.g., dilauroryl peroxide, benzoyl peroxide
  • photoinitiators e.g., isopropyl thioxanthone (ITX), Irgacure 651 and Irgacure 369 from Ciba-Geigy
  • the sealing composition is typically overcoated onto partially filled microcups and the overcoated microcups are dried at room temperature.
  • the sealed microcups optionally may be post treated by UV radiation or thermal baking to further improve the barrier properties.
  • the adhesion of the sealing layer to the microcups may also be improved by the post-curing reaction, likely due to the formation of an interpenetration network at the microcup-sealing layer inter-phase.
  • FIGS. 6 A- 6 D The preferred process of preparing the electrophoretic cells is illustrated schematically in FIGS. 6 A- 6 D.
  • the microcup array ( 60 ) may be prepared by any of the alternative methods described in Section III above.
  • the unfilled microcup array made by the methods described herein typically comprises a substrate web ( 63 ) upon which a base electrode ( 62 ) is deposited.
  • the microcup walls ( 61 ) extend upward from the substrate ( 63 ) to form the open cups.
  • the microcups are filled with a suspension of the charged pigment particles ( 65 ) in a colored dielectric solvent composition ( 64 ).
  • the composition is the same in each cup, i.e., in a monochrome display.
  • the microcups are preferably partially filled (to prevent overflow), which can be achieved by diluting the electrophoretic fluid with a volatile solvent (such as acetone, methyl ethyl ketone, isopropanol, hexane, and perfluoro solvent FC-33 from 3M Co.,) and allowing the volatile solvent to evaporate.
  • a volatile solvent such as acetone, methyl ethyl ketone, isopropanol, hexane, and perfluoro solvent FC-33 from 3M Co.
  • a perfluoro volatile solvent such as FC-33 is particularly useful to control the level of partial filling.
  • the microcups are sealed with the sealing composition of the present invention to form a sealing layer ( 66 ).
  • the sealing composition is typically overcoated onto the partially filled microcups and dried on the display fluid.
  • the sealed microcups optionally may be post treated by UV radiation or thermal baking to further improve the barrier properties.
  • the sealed array of electrophoretic microcup cells ( 60 ) is laminated with a second conductor film ( 67 ), preferably by pre-coating the conductor ( 67 ) with an adhesive layer ( 68 ) which may be a pressure sensitive adhesive, a hot melt adhesive, or a heat, moisture, or radiation curable adhesive.
  • the laminate adhesive may be post-cured by radiation such as UV through the top conductor film if the latter is transparent to the radiation.
  • the microcups are preferably filled with charged pigment particles dispersed in a dielectric solvent (e.g., solvent ( 64 ) and pigment particles ( 65 ) in FIG. 6B.).
  • a dielectric solvent e.g., solvent ( 64 ) and pigment particles ( 65 ) in FIG. 6B.
  • the dispersion may be prepared according to methods well known in the art, such as U.S. Pat. Nos. 6,017,584, 5,914,806, 5,573,711, 5,403,518, 5,380,362, 4,680,103, 4,285,801, 4,093,534, 4,071,430, and 3,668,106. See also IEEE Trans. Electron Devices, ED-24, 827 (1977), and J. Appl. Phys. 49(9), 4820 (1978).
  • the charged pigment particles visually contrast with the medium in which the particles are suspended.
  • the medium is a dielectric solvent which preferably has a low viscosity and a dielectric constant in the range of about 2 to about 30, preferably about 2 to about 15 for high particle mobility.
  • suitable dielectric solvents include hydrocarbons such as decahydronaphthalene (DECALIN), 5-ethylidene-2-norbomene, fatty oils, paraffin oil, aromatic hydrocarbons such as toluene, xylene, phenylxylylethane, dodecylbenzene and alkylnaphthalenes, halogenated solvents such as, dichlorobenzotrifluoride, 3,4,5-trichlorobenzotrifluoride, chloropentafluoro-benzene, dichlorononane, pentachlorobenzene, and perfluoro solvents such as perfluorodecalin, perfluorotoluene, perfluoroxylene, FC-43, FC-70 and FC-5060 from 3M Company, St.
  • hydrocarbons such as decahydronaphthalene (DECALIN), 5-ethylidene-2-norbomene, fatty oils, paraffin oil, aromatic hydrocarbon
  • halogen containing polymers such as poly(perfluoropropylene oxide) from TCI America, Portland, Oregon, poly(chlorotrifluoroethylene) such as Halocarbon Oils from Halocarbon Product Corp., River Edge, N.J., perfluoropolyalkylether such as Galden, HT-200, and Fluorolink from Ausimont (Thorofare, N.J.) or Krytox Oils and Greases K-Fluid Series from DuPont, Del.
  • poly(chlorotrifluoroethylene) is used as the dielectric solvent.
  • poly(perfluoropropylene oxide) is used as the dielectric solvent.
  • a non-migrating fluid colorant may be formed from dyes or pigments.
  • Nonionic azo and anthraquinone dyes are particularly useful.
  • useful dyes include, but are not limited to: Oil Red EGN, Sudan Red, Sudan Blue, Oil Blue, Macrolex Blue, Solvent Blue 35, Pylam Spirit Black and Fast Spirit Black from Pylam Products Co., Arizona, Sudan Black B from Aldrich, Thermoplastic Black X-70 from BASF, and anthraquinone blue, anthraquinone yellow 114, anthraquinone red 111, 135, anthraquinone green 28 from Aldrich.
  • Fluorinated dyes are particularly useful when perfluoro solvents are used.
  • the non-migrating pigment particles for generating the color of the medium may also be dispersed in the dielectric medium. These color particles are preferably uncharged. If the non-migrating pigment particles for generating color in the medium are charged, they preferably carry a charge which is opposite from that of the charged, migrating pigment particles. If both types of pigment particles carry the same charge, then they should have different charge density or different electrophoretic mobility. In any case, the dye or pigment for generating the non-migrating fluid colorant of the medium must be chemically stable and compatible with other components in the suspension.
  • the charged, migrating pigment particles may be organic or inorganic pigments, such as TiO 2 , phthalocyanine blue, phthalocyanine green, diarylide yellow, diarylide AAOT Yellow, and quinacridone, azo, rhodamine, perylene pigment series from Sun Chemical, Hansa yellow G particles from Kanto Chemical, and Carbon Lampblack from Fisher. Submicron particle size is preferred. These particles should have acceptable optical characteristics, should not be swollen or softened by the dielectric solvent, and should be chemically stable. The resulting suspension must also be stable against sedimentation, creaming or flocculation under normal operating conditions.
  • the migrating pigment particles may exhibit a native charge, or may be charged explicitly using a charge control agent, or may acquire a charge when suspended in the dielectric solvent.
  • Suitable charge control agents are well known in the art; they may be polymeric or non-polymeric in nature, and may also be ionic or non-ionic, including ionic surfactants such as Aerosol OT, sodium dodecylbenzenesulfonate, metal soaps, polybutene succinimide, maleic anhydride copolymers, vinylpyridine copolymers, vinylpyrrolidone copolymer (such as Ganex from International Specialty Products), (meth)acrylic acid copolymers, N,N-dimethylaminoethyl (meth)acrylate copolymers.
  • Fluorosurfactants are particularly useful as charge controlling agents in perfluorocarbon solvents. These include FC fluorosurfactants such as FC-170C, FC-171, FC-176, FC430, FC431 and FC-740 from 3M Company and Zonyl fluorosurfactants such as Zonyl FSA, FSE, FSN, FSN-100, FSO, FSO-100, FSD and UR from Dupont.
  • FC fluorosurfactants such as FC-170C, FC-171, FC-176, FC430, FC431 and FC-740 from 3M Company
  • Zonyl fluorosurfactants such as Zonyl FSA, FSE, FSN, FSN-100, FSO, FSO-100, FSD and UR from Dupont.
  • Suitable charged pigment dispersions may be manufactured by any of the well-known methods including grinding, milling, attriting, microfluidizing, and ultrasonic techniques. For example, pigment particles in the form of a fine powder are added to the suspending solvent and the resulting mixture is ball milled or attrited for several hours to break up the highly agglomerated dry pigment powder into primary particles. Although less preferred, a dye or pigment for producing the non-migrating fluid colorant may be added to the suspension during the ball milling process.
  • Sedimentation or creaming of the pigment particles may be eliminated by microencapsulating the particles with suitable polymers to match the specific gravity to that of the dielectric solvent.
  • Microencapsulation of the pigment particles may be accomplished chemically or physically. Typical microencapsulation processes include interfacial polymerization, in-situ polymerization, phase separation, coacervation, electrostatic coating, spray drying, fluidized bed coating and solvent evaporation.
  • the suspension comprises charged white particles of titanium oxide (TiO 2 ) dispersed in a black dielectric solution containing a black dye or dispersed uncharged black particles.
  • a black dye or dye mixture such as Pylam Spirit Black and Fast Spirit Black from Pylam Products Co. Arizona, Sudan Black B from Aldrich, Thermoplastic Black X-70 from BASF, or an insoluble black pigment such as carbon black may be used to generate the black color of the solvent.
  • a black dye or dye mixture such as Pylam Spirit Black and Fast Spirit Black from Pylam Products Co. Arizona, Sudan Black B from Aldrich, Thermoplastic Black X-70 from BASF, or an insoluble black pigment such as carbon black may be used to generate the black color of the solvent.
  • the charged TiO 2 particles may be suspended in a dielectric fluid of cyan, yellow or magenta color.
  • the cyan, yellow or magenta color may be generated via the use of a dye or a pigment.
  • the charged TiO 2 particles may be suspended in a dielectric fluid of red, green or blue color generated also via the use of a dye or a pigment.
  • the red, green, blue color system is preferred for most applications.
  • Ebecryl 600 35 parts by weight of Ebecryl 600 (UCB), 40 parts of SR-399 (Sartomer), 10 parts of Ebecryl 4827 (UCB), 7 parts of Ebecryl 1360 (UCB), 8 parts of HDDA, (UCB), 0.05 parts of Irgacure 369 (Ciba Specialty Chemicals) and 0.01 parts of isopropyl thioxanthone (ITX from Aldrich) were mixed homogeneously and used for micro-embossing.
  • microcup formulation prepared in Example 1 was coated onto the treated ITO/PET film with a targeted thickness of about 50 ⁇ m, embossed with a Ni—Co male mold having a 60 (length) ⁇ 60 (width) ⁇ m repetitive protrusion square pattern with 25-50 ⁇ m protrusion height and 10 ⁇ m wide partition lines, UV cured from the PET side for 20 seconds, removed from the mold with a 2′′ peeling bar at a speed of about 4-5 ft/min.
  • Well-defined micro-cups with depth ranging from 25 to 50 ⁇ m were prepared by using male molds having corresponding protrusion heights.
  • Microcup arrays of various dimension such as 70 (length) ⁇ 70 (width) ⁇ 35 (depth) ⁇ 10 (partition), 100 (L) ⁇ 100(W) ⁇ 35(D) ⁇ 10(P), and 100 (L) ⁇ 100(W) ⁇ 30(D) ⁇ 10(P) ⁇ m were also prepared by the same procedure.
  • Example 3 The same as Example 3, except the Ti Pure R706 and Fluorolink were replaced by a polymer coated TiO 2 particles PC-9003 from Elimentis (Highstown, N.J.) and Krytox (Du Pont) respectively. Note: replacing 2 things, Ti & fluorolink, with 1 thing, TiO2 PC-90003 from 2 suppliers, elimentis & krytox??
  • Example 3 The electrophoretic fluid prepared in Example 3 was diluted with a volatile perfluoro co-solvent FC-33 from 3M and coated onto a 35 microns deep microcup array prepared in Example 2.
  • the volatile cosolvent was allowed to evaporate to expose a partially filled microcup array.
  • a 7.5% solution of polyisoprene (97% cis, from Aldrich) in heptane was then overcoated onto the partially filled cups by a Universal Blade Applicator with an opening of 3 mil.
  • the overcoated microcups were then dried at room temperature.
  • a seamless sealing layer of about 7-8 ⁇ m thickness (dry) with acceptable adhesion and uniformity was formed on the microcup array. No observable entrapped air bubble in the sealed microcups was found under microscope.
  • a second ITO/PET conductor precoated with an adhesive layer was laminated onto the sealed microcups.
  • the electrophoretic cell showed satisfactory switching performance with good flexure resistance. No observable weight loss was found after being aged in a 66° C. oven for 5 days.
  • Example 5 The same as Example 5, except the thickness of the polyisoprene layer was reduced to 4 microns by using a blade applicator of 2 mil opening. Pinholes and broken sealing layer were clearly observed under optical microscope.
  • Mw , polyvinylbutyral (Butvar 72, from Solutia Inc., St. Louis, Mo.)
  • thermpoplastic elastomers such as SIS (Kraton D1107, 15% styrene), SBS (Kraton D1101, 31% styrene) SEBS (Kraton G1650 and FG1901, 30% styrene), and EPDM (Vistalon 6505, 57%
  • microcups may also be used for manufacturing microcup arrays for liquid crystal displays.
  • microcup selective filling, sealing and ITO laminating methods of the invention may also be employed in the manufacture of liquid crystal displays.

Abstract

The invention relates to a novel sealing composition for the manufacture of an electrophoretic or liquid crystal display, and a sealing process using the composition. The composition allows electrophoretic or liquid crystal cells to be seamlessly sealed and the sealing layer free of any defects.

Description

    BACKGROUND
  • The electrophoretic display (EPD) is a non-emissive device based on the electrophoresis phenomenon influencing charged pigment particles suspended in a solvent. This general type of display was first proposed in 1969. An EPD typically comprises a pair of opposed, spaced-apart plate-like electrodes, with spacers predetermining a certain distance between the electrodes. One of the electrodes is typically transparent. A suspension composed of a colored solvent and suspended charged pigment particles is enclosed between the two plates. [0001]
  • When a voltage difference is imposed between the two electrodes, the pigment particles migrate by attraction to the plate of polarity opposite that of the pigment particles. Thus the color showing at the transparent plate may be determined by selectively charging the plates to be either the color of the solvent or the color of the pigment particles. Reversal of plate polarity will cause the particles to migrate back to the opposite plate, thereby reversing the color. Intermediate color density (or shades of gray) due to intermediate pigment density at the transparent plate may be obtained by controlling the voltage or charging time. [0002]
  • Among the advantages of an electrophoretic display (EPD) over other types of flat panel displays is the very low power consumption. This salient advantage makes EPDs particularly suitable for portable and battery powered devices such as laptops, cell phones, personal digital assistants, portable electronic medical and diagnostic devices, global positioning system devices, and the like. [0003]
  • In order to prevent undesired movements of the particles such as sedimentation, partitions were proposed between the two electrodes for dividing the space into smaller cells. See, e.g., M. A Hopper and V. Novotny, IEEE Trans. Electr. Dev., Vol ED 26, No. 8, pp 1148-1152 (1979). However, in the case of the partition-type EPD, some difficulties are encountered in the formation of the partitions and the process of enclosing the suspension. Furthermore, it is also difficult to keep different colors of suspensions separate from each other in the partition-type EPD. [0004]
  • Attempts have been made to enclose the suspension in microcapsules. U.S. Pat. Nos. 5,961,804 and 5,930,026 describe microencapsulated EPDs. These displays have a substantially two dimensional arrangement of microcapsules each containing an electrophoretic composition comprising a dielectric fluid with charged pigment particles suspended therein and the particles visually contrast with the dielectric solvent. The microcapsules can be formed by interfacial polymerization, in-situ polymerization or other known methods such as in-liquid curing or simple/complex coacervation. The microcapsules, after their formation, may be injected into a cell housing two spaced-apart electrodes, or they may be “printed” into or coated on a transparent conductor film. The microcapsules may also be immobilized within a transparent matrix or binder that is itself sandwiched between the two electrodes. [0005]
  • The EPDs prepared by these prior art processes, in particular the microencapsulation process, as disclosed in U.S. Pat. Nos. 5,930,026, 5,961,804, and 6,017,584, have several shortcomings. For example, the EPDs manufactured by the microencapsulation process suffer from sensitivity to environmental changes (in particular sensitivity to moisture and temperature) due to the wall chemistry of the microcapsules. Secondly the EPDs based on the microcapsules have poor scratch resistance due to the thin wall and large particle size of the microcapsules. To improve the handleability of the display, microcapsules are embedded in a large quantity of polymer matrix which results in a slow response time due to the large distance between the two electrodes and a low contrast ratio due to the low payload of pigment particles. It is also difficult to increase the surface charge density on the pigment particles because charge-controlling agents tend to diffuse to the water/oil interface during the microencapsulation process. The low charge density or zeta potential of the pigment particles in the microcapsules also results in a slow response rate. Furthermore, because of the large particle size and broad size distribution of the microcapsules, the prior art EPD of this type has poor resolution and addressability for color applications. [0006]
  • Recently an improved EPD technology was disclosed in co-pending applications, U.S. Ser. No. 09/518,488, filed on Mar. 3, 2000 and U.S. Ser. No. 09/784,972, filed on Feb. 25, 2001. The cells of the improved EPD are formed from a plurality of microcups which are formed integrally with one another as portions of a structured two-dimensional array assembly. Each microcup of the array assembly is filled with a suspension or dispersion of charged pigment particles in a dielectric solvent, and sealed to form an electrophoretic cell. [0007]
  • The substrate web upon which the microcups are formed includes a display addressing array comprising preformed conductor film, such as ITO conductor lines. The conductor film (ITO lines) is coated with a radiation curable polymer precursor layer. The film and precursor layer are then exposed imagewise to radiation to form the microcup wall structure. Following exposure, the precursor material is removed from the unexposed areas, leaving the cured microcup walls bonded to the conductor film/support web. The imagewise exposure may be accomplished by UV or other forms of radiation through a photomask to produce an image or predetermined pattern of exposure of the radiation curable material coated on the conductor film. Although it is generally not required, the mask may be positioned and aligned with respect to the conductor film, i.e., ITO lines, so that the transparent mask portions align with the spaces between ITO lines, and the opaque mask portions align with the ITO material (intended for microcup cell floor areas). [0008]
  • Alternatively, the microcup array may be prepared by a process including embossing a thermoplastic or thermoset precursor layer coated on a conductor film with a pre-patterned male mold, followed by releasing the mold. The precursor layer may be hardened by radiation, cooling, solvent evaporation, or other means during or after the embossing step. This novel micro-embossing method is disclosed in the co-pending application, U.S. Ser. No. 09/518,488, filed Mar. 3, 2000. [0009]
  • Solvent-resistant, thermomechanically stable microcups having a wide range of size, shape, pattern and opening ratio can be prepared by either one of the aforesaid methods. [0010]
  • The manufacture of a monochrome EPD from a microcup assembly involves filling the microcups with a single pigment suspension composition, sealing the microcups, and finally laminating the sealed array of microcups with a second conductor film pre-coated with an adhesive layer. [0011]
  • For a color EPD, its preparation from a microcup assembly involves sequential selective opening and filling of predetermined microcup subsets. The process includes laminating or coating the preformed microcups with a layer of positively working photoresist, selectively opening a certain number of the microcups by imagewise exposing the positive photoresist, followed by developing the resist, filling the opened cups with a colored electrophoretic fluid, and sealing the filled microcups by a sealing process. These steps may be repeated to create sealed microcups filled with electrophoretic fluids of different colors. Thus, the array may be filled with different colored compositions in predetermined areas to form a color EPD. Various known pigments and dyes provide a wide range of color options for both solvent phase and suspended particles. Known fluid application and filling mechanisms may be employed. [0012]
  • The sealing of the microcups after they are filled with a dispersion of charged pigment particles in a dielectric fluid can be accomplished by overcoating the electrophoretic fluid with a solution containing a thermoplastic or thermoset precursor. To reduce or eliminate the degree of intermixing during and after the overcoating process, it is highly advantageous to use a sealing composition that is immiscible with the electrophoretic fluid and preferably has a specific gravity lower than the dielectric fluid. The sealing is then accomplished by hardening the precursor by solvent evaporation, interfacial reaction, moisture, heat, radiation, or a combination of curing mechanisms. Alternatively, the sealing can be accomplished by dispersing a thermoplastic or thermoset precursor in the electrophoretic fluid before the filling step. The thermoplastic or thermoset precursor is immiscible with the dielectric solvent and has a specific gravity lower than that of the solvent and the pigment particles. After filling, the thermoplastic or thermoset precursor phase separates from the electrophoretic fluid and forms a supernatant layer at the top of the fluid. The sealing of the microcups is then conveniently accomplished by hardening the precursor layer by solvent evaporation, interfacial reaction, moisture, heat, or radiation. UV radiation is the preferred method to seal the microcups, although a combination of two or more curing mechanisms as described above may be used to increase the throughput of sealing. [0013]
  • The improved EPDs may also be manufactured by a synchronized roll-to-roll photolithographic exposure process as described in the co-pending application, U.S. Ser. No. 09/784,972, filed on Feb. 25, 2001. A photomask may be synchronized in motion with the support web using mechanisms such as coupling or feedback circuitry or common drives to maintain the coordinated motion (i.e., to move at the same speed). Following exposure, the web moves into a development area where the unexposed material is removed to form the microcup wall structure. The microcups and ITO lines are preferably of selected size and coordinately aligned with the photomask, so that each completed display cell (i.e., filled and sealed microcup) may be discretely addressed and controlled by the display driver. The ITO lines may be pre-formed by either a wet or a dry etching process on the substrate web. [0014]
  • For making color displays from the microcup array, the synchronized roll-to-roll exposure photolithographic process also enables continuous web processes of selective opening, filling and sealing of pre-selected subsets of the microcup array. [0015]
  • The microcup array may be temporarily sealed by laminating or coating with a positive-acting photoresist composition, imagewise exposing through a corresponding photomask, and developing the exposed area with a developer to selectively open a desired subset of the microcups. Known laminating and coating mechanisms may be employed. The term “developer” in this context refers to a suitable known means for selectively removing the exposed photoresist, while leaving the unexposed photoresist in place. [0016]
  • Thus, the array may be sequentially filled with several different color compositions (typically three primary colors) in a pre-determined cell pattern. For example, the imagewise exposure process may employ a positively working photoresist top laminate or coating which initially seals the empty microcups. The microcups are then exposed through a mask (e.g., a loop photomask in the described roll-to-roll process) so that only a first selected subset of microcups are exposed. Development with a developer removes the exposed photoresist and thus opens the first microcup subset to permit filling with a selected color pigment dispersion composition, and sealing by one of the methods described herein. The exposure and development process is repeated to expose and open a second selected microcup subset, for filling with a second pigment dispersion composition, with subsequent sealing. Finally, the remaining photoresist is removed and the third subset of microcups is filled and sealed. [0017]
  • Liquid crystal displays (LCDs) may also be prepared by the method as described above when the electrophoretic fluid is replaced by a suitable liquid crystal composition having the ordinary refractive index matched to that of the isotropic cup material. In the “on” state, the liquid crystal in the microcups is aligned to the field direction and is transparent. In the “off” state, the liquid crystal is not aligned and scatters light. To maximize the light scattering effect of the LCDs, the diameter of the microcups is typically in the range of 0.5-10 microns. [0018]
  • The roll-to-roll process may be employed to carry out a sequence of processes on a single continuous web, by carrying and guiding the web to a plurality of process stations in sequence. In other words, the microcups may be formed, filled or coated, developed, sealed, and laminated in a continuous sequence. [0019]
  • In addition to the manufacture of microcup displays, the synchronized roll-to-roll process may be adapted to the preparation of a wide range of structures or discrete patterns for electronic devices formable upon a support web substrate, e.g., patterned conductor films, flexible circuit boards and the like. As in the process and apparatus for EPD microcups described herein, a pre-patterned photomask is prepared which includes a plurality of photomask portions corresponding to structural elements of the subject device. Each such photomask portion may have a pre-selected area of transparency or opacity to radiation so as to form an image of such a structural element upon the correspondingly aligned portion of the web during exposure. The method may be used for selective curing of structural material, or may be used to expose positively or negatively acting photoresist material during manufacturing processes. [0020]
  • Because these multiple-step processes may be carried out roll-to-roll continuously or semi-continuously, they are suitable for high volume and low cost production. These processes are also efficient and inexpensive as compared to other processes for manufacturing display products. The improved EPD involving microcups is not sensitive to environment, such as humidity and temperature. The display is thin, flexible, durable, easy-to-handle, and format-flexible. Since the EPD comprises cells of favorable aspect ratio and well-defined shape and size, the bi-stable reflective display has excellent color addressability, high contrast ratio and color saturation, fast switching rate and response time. [0021]
  • SUMMARY OF THE INVENTION
  • Sealing of the microcups by a continuous web process is one of the most critical steps in the roll-to-roll manufacturing of the improved EPDs. In order to prepare a high quality display, the sealing layer must have at least the following characteristics: (1) free of defects such as entrapped air bubble, pin holes, cracking or leaking, etc; (2) good film integrity and barrier properties against the display fluid such as dielectric fluids for EPDs; and (3) good coating and adhesion properties. Since most of the dielectric solvents used in EPDs are of low surface tension and low viscosity, it has been a major challenge to achieve a seamless, defect-free sealing with good adhesion properties for the microcups. [0022]
  • It has now been found that microcups filled with a display fluid such as an electrophoretic fluid can be sealed seamlessly and free of defects by a continuous web process using a novel sealing overcoat composition comprising the following ingredients: [0023]
  • (1) a solvent or solvent mixture which is immiscible with the display fluid in the microcups and exhibits a specific gravity less than that of the display fluid; and [0024]
  • (2) a thermoplastic elastomer. [0025]
  • Compositions containing at least a thermoplastic elastomer having good compatibility with the microcups and good barrier properties against the display fluid are particularly useful. Examples of useful thermoplastic elastomers include di-block, tri-block or multi-block copolymers represented by the formulas ABA or (AB)n in which A is styrene, α-methylstyrene, ethylene, propylene or norbonene; B is butadiene, isoprene, ethylene, proplyene, butylene, dimethoylsiloxane or propylene sulfide; and A and B cannot be the same in the formula. The number, n, is ≧1, preferably 1-10. Representative copolymers include poly(styrene-b-butadiene), poly(styrene-b-butadiene-b-styrene), poly(styrene-b-isoprene-b-styrene), poly(styrene-b-ethylene/butylene-b-styrene), poly(styrene-b-dimethylsiloxane-b-styrene), poly((α-methylstyrene-b-isoprene), poly(α-methylstyrene-b-isoprene-b-α-methylstyrene), poly(α-methylstyrene-b-propylene sulfide-b-α-methylstyrne), and poly(α-methylstyrene-b-dimethylsiloxane-b-α-methylstyrene). A review of the preparation of the thermoplastic elastomers can be found in N. R. Legge, G. Holden, and H. E. Schroeder ed., “Thermoplastic Elastomers”, Hanser Publisher (1987). Commercially available styrene block copolymers such as Kraton D and G series from Shell Chemical Company are particularly useful. Crystalline rubbers such as poly(ethylene-co-propylene-co-5-methylene-2-norbomene) or EPDM (ethylene-propylene-diene terpolymer) rubbers and their grafted copolymers have also been found very useful. Not to be bound by the theory, it is believed that the hard block of the thermoplastic elastomers phase separates during or after the drying of the sealing overcoat and serves as the physical crosslinker of the soft continuous phase. The sealing composition of the present invention significantly enhances the modulus and film integrity of the sealing layer throughout the coating and drying processes. Thermoplastic elastomers having low critical surface tension (lower than 40 dyne/cm) and high modulus or Shore A hardness (higher than 60) have been found useful probably because of their favorable wetting property and film integrity over the display fluid. [0026]
  • The thermoplastic elastomer is dissolved in a solvent or solvent mixture which is immiscible with the display fluid in the microcups and exhibits a specific gravity less than that of the display fluid. Low surface tension solvents are preferred for the overcoating composition because of their better wetting properties over the microcup surface and the electrophoretic fluid. Solvents or solvent mixtures having a surface tension lower than 35 dyne/cm are preferred. A surface tension lower than 30 dyne/cm is more preferred. Suitable solvents include alkanes (preferably C[0027] 6-12 alkanes such as heptane, octane or Isopar solvents from Exxon Chemical Company, nonane, decane and their isomers), cycloalkanes (preferably C6-12 cycloalkanes such as cyclohexane, decalin and the like), alkylbenzenes (preferably mono- or di-C1-6 alkyl benzenes such as toluene, xylene and the like), alkyl esters (preferably C2-5 alkyl esters such as ethyl acetate, isobutyl acetate and the like) and C3-5 alkyl alcohols (such as isopropanol and the like and their isomers.
  • In addition to the fact that the electrophoretic cells prepared from microcups may be sealed seamlessly and free of defects by a continuous web process using this novel sealing composition, the composition also has many other advantages. For example, it also exhibits good wetting properties over the filled microcups throughout the coating process and develops a good film integrity over the display fluid even before the solvent evaporates completely. As a result, the integrity of the coating is maintained and no dewetting or beading on the electrophoretic fluid is observed. In addition, the composition of the present invention enables the continuous sealing of wider microcups, particularly those having a width greater than 100 microns. Wider microcups are preferred in some applications because of their higher microcup opening-to-wall ratio and better display contrast ratio. Furthermore, the sealing composition of the present invention enables the formation of a sealing layer less than 3 microns thick which is typically difficult to achieve by using traditional sealing compositions. The thinner sealing layer shortens the distance between the top and bottom electrodes and results in a faster switching rate. [0028]
  • Co-solvents and wetting agents may also be included in the composition to improve the adhesion of the sealant to the microcups and provides a wider coating process latitude. Other ingredients such as crosslinking agents, vulcanizers, multifunctional monomers or oligomers, and high Tg polymers that are miscible with one of the blocks of the thermoplastic elastomer are also highly useful to enhance the physicomechanical properties of the sealing layer during or after the overcoating process. The sealed microcups may be post treated by UV radiation or thermal baking to further improve the barrier properties. The adhesion of the sealing layer to the microcups may also be improved by the post-curing reaction, probably due to the formation of an interpenetration network at the microcup-sealing sealing layer inter-phase.[0029]
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • FIG. 1 is a schematic cross-section of an EPD, showing three microcup cells in a neutral condition. [0030]
  • FIG. 2 is a schematic cross-section of the EPD of FIG. 1, but with two of the cells charged, to cause the pigment to migrate to one plate. [0031]
  • FIGS. [0032] 3A-3C shows the contours of an exemplary microcup array, FIG. 3A showing a perspective view, FIG. 3B showing a plan view, and FIG. 3C showing an elevation view, the vertical scale being exaggerated for clarity.
  • FIGS. 4A and 4B show the basic processing steps for preparing the microcups involving imagewise photolithographic exposure through a photomask (“top exposure”) of the conductor film coated with a thermoset precursor, to UV radiation. [0033]
  • FIGS. 5A and 5B show alternative processing steps for preparing the microcups involving imagewise photolithography combining the top exposure and bottom exposure principles, whereby the walls are cured in one lateral direction by top photomask exposure and in the perpendicular lateral direction by bottom exposure through the opaque base conductor film (“combined exposure”). [0034]
  • FIGS. [0035] 6A-6D are a sequence of cross sections of a microcup array, illustrating the steps of assembling a monochrome display.
  • DETAILED DESCRIPTION OF THE INVENTION I. Definitions
  • Unless defined otherwise in this specification, all technical terms are used herein according to their conventional definitions as they are commonly used and understood by those of ordinary skill in the art. [0036]
  • The term “microcup” refers to the cup-like indentations, which may be created by methods such as micro-embossing or imagewise exposure as described in the co-pending patent applications identified above. Likewise, the plural form “microcups” in a collective context may in general refer to the microcup assembly comprising a plurality of such microcups integrally formed or joined to make a structured two-dimensional microcup array. [0037]
  • The term “cell”, in the context of the present invention, is intended to mean the single unit formed from a sealed microcup. The cells are filled with charged pigment particles dispersed in a solvent or solvent mixture. [0038]
  • The term “well-defined”, when describing the microcups or cells, is intended to indicate that the microcup or cell has a definite shape, size, pattern and aspect ratio which are predetermined according to the specific parameters of the manufacturing process. [0039]
  • The term “aspect ratio” is a commonly known term in the art and is the depth to width ratio or the depth to diameter ratio of the microcup opening. [0040]
  • The term “imagewise exposure” means exposure of radiation-curable material or photoresist composition to radiation, such as UV, using one of the methods of the invention, whereby the portions of the material so exposed are controlled to form a pattern or “image” corresponding to the structure of the microcups, e.g., the exposure is restricted to the portions of the material corresponding to the microcup walls, leaving the microcup floor portion unexposed. In the case of selectively opening photoresist on predetermined portions of the microcup array, imagewise exposure means exposure on the portions of material corresponding to the cup opening, leaving the microcup walls unexposed. The pattern or image may be formed by such methods as exposure through a photomask, or alternatively by controlled particle beam exposure, and the like. [0041]
  • II. The Microcup Array
  • FIGS. 1 and 2 are schematic cross-section views of an exemplary microcup array assembly embodiment, simplified for clarity, showing a microcup array assembly ([0042] 10) of three microcup cells (12 a, b, and c).
  • As shown in FIG. 1, each cell ([0043] 12) of array (10) comprises two electrode plates (11, 13), at least one of which is transparent (11), such as an ITO electrode, the electrodes (11) and (13) bounding two opposite faces of the cell (12).
  • The microcup cell array assembly ([0044] 10) comprises a plurality of cells which are disposed adjacent to one another within a plane to form a layer of cells (12) enclosed between the two electrodes layers (11) and (13). Three exemplary cells (12 a), (12 b), and (12 c) are shown, bounded by their respective electrode plates (11 a), (11 b), and (11 c) (transparent) and (13 a), (13 b), and (13 c) (back plates), it being understood that a large number of such cells are preferably arrayed two-dimensionally (to the right/left and in/out of the plane in FIG. 1) to form a sheet-like display of any selected area and two-dimensional shape. Likewise, several microcup cells may be bounded by a single electrode plate (11) or (13), although, for clarity, FIG. 1 shows an example in which each cell (12) is bounded by separate electrode plates (11) and (13) having the width of a single cell.
  • The cells are of well-defined shape and size and are filled with a colored dielectric solvent ([0045] 14) in which charged pigment particles (15) are suspended and dispersed. The cells (12) may be each filled with the same composition of pigment and solvent (e.g., in a monochrome display) or may be filled with different compositions of pigment and solvent (e.g., in a color display). FIG. 1 shows three different color combinations as indicated by the different hatch pattern in each cell (12 a), (12 b), and (12 c), the solvents being designated (14 a), (14 b), and (14 c) respectively, and the pigment particles being designated (15 a), (15 b), and (15 c) respectively.
  • The microcup cells ([0046] 12) each comprise enclosing walls (16) bounding the cells on the sides (within the plane of array (10)) and floor (17) bounding the cell on one face, in this example the face adjacent to electrode (13). On the opposite face (adjacent electrode (11)) each cell comprises sealing cap portion (18). Where the sealing cap portion is adjacent to the transparent electrode (11) (as in FIG. 1), the sealing cap (18) comprises a transparent composition. Although in the example of FIG. 1, the floor (17) and the sealing cap (18) are shown as separate cell portions distinct from adjacent electrodes (13) and (11) respectively, alternative embodiments of the microcup array (10) of the invention may comprise an integral floor/electrode structure or an integral sealing cap/electrode structure.
  • FIG. 2 is a schematic cross-section of the EPD of FIG. 1, but with two of the cells charged ([0047] 12 a and 12 c), to cause the pigment to migrate to one plate. When a voltage difference is imposed between the two electrodes (11, 13), the charged particles (15) migrate (i.e., toward electrode (11) or (13) depending on the charge of the particle and electrode), such that either the color of the pigment particle (15) or the color of the solvent (14) is seen through the transparent conductor film (11). At least one of the two conductors (11) or (13) is patterned (separately addressable portions ) to permit a selective electric field to be established with respect to either each cell or with respect to a pre-defined group of cells (e.g., to form a pixel).
  • In the example of FIG. 2, two of the cells are shown charged ([0048] 12 a and 12 c), in which the pigment (15 a and 15 c) has migrated to the respective transparent electrode plates (11 a and 11 c). The remaining cell (12 b) remains neutral and pigment (15 b) is dispersed throughout solvent (14 b).
  • FIGS. [0049] 3A-3C shows the contours of an exemplary portion of a microcup array, FIG. 3A showing a perspective view, FIG. 3B showing a plan view, and FIG. 3C showing an elevation view, the vertical scale being exaggerated for clarity. For reflective EPDs, the opening area of each individual microcup may preferably be in the range of about 102 to about 5×105 μm2, more preferably from about 103 to about 5×104 μm2. The width w of the microcup (12) (distance between adjacent walls (16)) may vary over a wide range, and is selectable to suit the desired final display characteristics. The width w of the microcup openings preferably is in the range of from about 15 to about 450 μm, and more preferably from about 25 to about 300 μm from edge to edge of the openings. Each microcup may form a small segment of a pixel of the final display, or may be a full pixel.
  • The wall thickness t relative to the cup width w may vary over a large range, and is selectable to suit the desired final display characteristics. The microcup wall thickness is typically from about 0.01 to about 1 times the microcup width, and more preferably about 0.05 to about 0.25 times the microcup width. The opening-to-total area ratio is preferably in the range of about 0.1 to about 0.98, more preferably from about 0.3 to about 0.95. [0050]
  • The microcup wall height h (which defines the cup depth) is shown exaggerated beyond its typical proportional dimensions for clarity. For EPDs, the height of the microcups is typically in the range of about 5 to about 100 microns (μms), preferably from about 10 to about 50 microns. For LCDs, the height is typically in the range of about 1 to 10 microns and more preferably from about 2 to 5 microns. [0051]
  • For simplicity and clarity, a square microcup arranged in a linear two-dimensional array assembly is assumed in the description herein of the microcup array assembly of the invention. However, the microcup need not be square, it may be rectangular, circular, or a more complex shape if desired. For example, the microcups may be hexagonal and arranged in a hexagonal close-packed array, or alternatively, triangular cups may be oriented to form hexagonal sub-arrays, which in turn are arranged in a hexagonal close-packed array. [0052]
  • In general, the microcups can be of any shape, and their sizes, pattern and shapes may vary throughout the display. This may be advantageous in the color EPD. In order to maximize the optical effect, microcups having a mixture of different shapes and sizes may be produced. For example, microcups filled with a dispersion of the red color may have a different shape or size from the green microcups or the blue microcups. Furthermore, a pixel may consist of different numbers of microcups of different colors. For example, a pixel may consist of a number of small green microcups, a number of large red microcups, and a number of small blue microcups. It is not necessary to have the same shape and number for the three colors. [0053]
  • The openings of the microcups may be round, square, rectangular, hexagonal, or any other shapes. The partition area between the openings is preferably kept small in order to achieve a high color saturation and contrast while maintaining desirable mechanical properties. Consequently the honeycomb-shaped opening is preferred over, for example, the circular opening. [0054]
  • III. Preparation Of The Microcup Array
  • The microcups may be prepared by microembossing or by photolithography. [0055]
  • IIIa. Preparation of Microcups Array by Microembossing Preparation of the Male Mold
  • The male mold may be prepared by any appropriate method, such as a diamond turn process or a photoresist process followed by either etching or electroplating. A master template for the male mold may be manufactured by any appropriate method, such as electroplating. With electroplating, a glass base is sputtered with a thin layer (typically 3000 Å) of a seed metal such as chrome inconel. It is then coated with a layer of photoresist and exposed to UV. A mask is placed between the UV and the layer of photoresist. The exposed areas of the photoresist become hardened. The unexposed areas are then removed by washing them with an appropriate solvent. The remaining hardened photoresist is dried and sputtered again with a thin layer of seed metal. The master is then ready for electroforming. A typical material used for electroforming is nickel cobalt. Alternatively, the master can be made of nickel by electroforming or electroless nickel deposition as described in “Continuous manufacturing of thin cover sheet optical media”, SPIE Proc. Vol. 1663, pp. 324 (1992). The floor of the mold is typically between about 50 to 400 microns. The master can also be made using other microengineering techniques including e-beam writing, dry etching, chemical etching, laser writing or laser interference as described in “Replication techniques for micro-optics”, SPIE Proc. Vol. 3099, pp. 76-82 (1997). Alternatively, the mold can be made by photomachining using plastics, ceramics or metals. [0056]
  • The male mold thus prepared typically has protrusions between about 1 to 500 microns, preferably between about 2 to 100 microns, and most preferred about 4 to 50 microns. The male mold may be in the form of a belt, a roller, or a sheet. For continuous manufacturing, the belt type of mold is preferred. [0057]
  • Microcup Formation
  • Micro-cups may be formed either in a batchwise process or in a continuous roll-to-roll process as disclosed in the co-pending application, U.S. Ser. No. 09/784,972, filed on Feb. 25, 2001. The latter offers a continuous, low cost, high throughput manufacturing technology for production of compartments for use in electrophoretic or LCDs. Prior to applying a UV curable resin composition, the mold may be treated with a mold release to aid in the demolding process. The UV curable resin may be degassed prior to dispensing and may optionally contain a solvent. The solvent, if present, readily evaporates. The UV curable resin is dispensed by any appropriate means such as, coating, dipping, pouring and the like, over the male mold. The dispenser may be moving or stationary. A conductor film is overlaid the UV curable resin. Examples of suitable conductor film include transparent conductor ITO on plastic substrates such as polyethylene terephthalate, polyethylene naphthate, polyaramid, polyimide, polycycloolefin, polysulfone, epoxy and their composites. Pressure may be applied, if necessary, to ensure proper bonding between the resin and the plastic and to control the thickness of the floor of the micro-cups. The pressure may be applied using a laminating roller, vacuum molding, press device or any other like means. If the male mold is metallic and opaque, the plastic substrate is typically transparent to the actinic radiation used to cure the resin. Conversely, the male mold can be transparent and the plastic substrate can be opaque to the actinic radiation. To obtain good transfer of the molded features onto the transfer sheet, the conductor film needs to have good adhesion to the UV curable resin which should have a good release property against the mold surface. [0058]
  • IIIb. Preparation of Microcup Array by Photolithography
  • The photolithographic processes for preparation of the microcup array are described in FIGS. 4 and 5. [0059]
  • Top Exposure
  • As shown in FIGS. 4A and 4B, the microcup array ([0060] 40) may be prepared by exposure of a radiation curable material (41 a) coated by known methods onto a conductor electrode film (42) to UV light (or alternatively other forms of radiation, electron beams and the like) through a mask (46) to form walls (41 b) corresponding to the image projected through the mask (46). The base conductor film (42) is preferably mounted on a supportive substrate base web (43), which may comprise a plastic material.
  • In the photomask ([0061] 46) in FIG. 4A, the dark squares (44) represent the opaque area and the space between the dark squares represents the transparent area (45) of the mask (46). The UV radiates through the transparent area (45) onto the radiation curable material (41 a). The exposure is preferably directly onto the radiation curable material (41 a), i.e., the UV does not pass through the substrate (43) or base conductor (42) (top exposure). For this reason, neither the substrate (43) nor the conductor (42) needs to be transparent to the UV or other radiation wavelengths employed.
  • As shown in FIG. 4B, the exposed areas ([0062] 41 b) become hardened and the unexposed areas (protected by the opaque area (44) of the mask (46) are then removed by an appropriate solvent or developer to form the microcups (47). The solvent or developer is selected from those commonly used for dissolving or reducing the viscosity of radiation curable materials such as methylethylketone (MEK), toluene, acetone, isopropanol or the like. The preparation of the microcups may be similarly accomplished by placing a photomask underneath the conductor film/substrate support web and in this case the UV light radiates through the photomask from the bottom and the substrate needs to be transparent to radiation.
  • Exposure Through Opaque Conductor Lines
  • Still another alternative method for the preparation of the microcup array of the invention by imagewise exposure is illustrated in FIGS. 5A and 5B. When opaque conductor lines are used, the conductor lines can be used as the photomask for the exposure from the bottom. Durable microcup walls are formed by additional exposure from the top through a second photomask having opaque lines perpendicular to the conductor lines. [0063]
  • FIG. 5A illustrates the use of both the top and bottom exposure principals to produce the microcup array ([0064] 50) of the invention. The base conductor film (52) is opaque and line-patterned. The radiation curable material (51 a), which is coated on the base conductor (52) and substrate (53), is exposed from the bottom through the conductor line pattern (52) which serves as the first photomask. A second exposure is performed from the “top” side through the second photomask (56) having a line pattern perpendicular to the conductor lines (52). The spaces (55) between the lines (54) are substantially transparent to the UV light. In this process, the wall material (51 b) is cured from the bottom up in one lateral orientation, and cured from the top down in the perpendicular direction, joining to form an integral microcup (57).
  • As shown in FIG. 5B, the unexposed area is then removed by a solvent or developer as described above to reveal the microcups ([0065] 57).
  • IV. The Sealing Composition and Process of the Present Invention
  • The novel sealing overcoat composition comprises the following ingredients: [0066]
  • (1) a solvent or solvent mixture which is immiscible with the display fluid in the microcups and exhibits a specific gravity less than that of the display fluid; and [0067]
  • (2) a thermoplastic elastomer. [0068]
  • Compositions containing a thermoplastic elastomer having good compatibility with the microcups and good barrier properties against the display fluid are particularly useful. Examples of useful thermoplastic elastomers include ABA, and (AB)n type of di-block, tri-block, and multi-block copolymers wherein A is styrene, α-methylstyrene, ethylene, propylene or norbonene; B is butadiene, isoprene, ethylene, propylene, butylene, dimethylsiloxane or propylene sulfide; and A and B cannot be the same in the formula. The number, n, is ≧1, preferably 1-10. Particularly useful are di-block or tri-block copolymers of styrene or ox-methylstyrene such as SB (poly(styrene-b-butadiene)), SBS (poly(styrene-b-butadiene-b-styrene)), SIS (poly(styrene-b-isoprene-b-styrene)), SEBS (poly(styrene-b-ethylene/butylenes-b-stylene)) poly(styrene-b-dimethylsiloxane-b-styrene), poly((α-methylstyrene-b-isoprene), poly(α-methylstyrene-b-isoprene-b-α-methylstyrene), poly(α-methylstyrene-b-propylene sulfide-b-α-methylstyrene), poly(α-methylstyrene-b-dimethylsiloxane-b-α-methylstyrene). A review of the preparation of the thermoplastic elastomers can be found in N. R. Legge, G. Holden, and H. E. Schroeder ed., “Thermoplastic Elastomers”, Hanser Publisher (1987). Commercially available styrene block copolymers such as Kraton D and G series (from Kraton Polymer, Houston, Tex.) are particularly useful. Crystalline rubbers such as poly(ethylene-co-propylene-co-5-methylene-2-norbomene) or EPDM (ethylene-propylene-diene terpolymer) rubbers such as Vistalon 6505 (from Exxon Mobil, Houston, Tex.) and their grafted copolymers have also been found very useful. [0069]
  • Not to be bound by the theory, it is believed that the hard block of the thermoplastic elastomers phase separates during or after the drying of the sealing overcoat and serves as the physical crosslinker of the soft continuous phase. The sealing composition of the present invention significantly enhances the modulus and film integrity of the sealing layer throughout the coating and drying processes of the sealing layer. Thermoplastic elastomers having low critical surface tension (lower than 40 dyne/cm) and high modulus or Shore A hardness (higher than 60) have been found useful probably because of their favorable wetting property and film integrity over the display fluid. [0070]
  • The thermoplastic elastomer is dissolved in a solvent or solvent mixture which is immiscible with the display fluid in the microcups and exhibits a specific gravity less than that of the display fluid. Low surface tension solvents are preferred for the overcoating composition because of their better wetting properties over the microcup walls and the electrophoretic fluid. Solvents or solvent mixtures having a surface tension lower than 35 dyne/cm are preferred. A surface tension of lower than 30 dyne/cm is more preferred. Suitable solvents include alkanes (preferably C[0071] 6-12 alkanes such as heptane, octane or Isopar solvents from Exxon Chemical Company, nonane, decane and their isomers), cycloalkanes (preferably C6-12 cycloalkanes such as cyclohexane and decalin and the like), alkylbezenes (preferably mono- or
  • di-C[0072] 1-6 alkyl benzenes such as toluene, xylene and the like), alkyl esters (preferably C2-5 alkyl esters such as ethyl acetate, isobutyl acetate and the like) and C3-5 alkyl alcohols (such as isopropanol and the like and their isomers). Mixtures of alkylbenzene and alkane are particularly useful.
  • Wetting agents (such as the FC surfactants from 3M Company, Zonyl fluorosurfactants from DuPont, fluoroacrylates, fluoromethacrylates, fluoro-substituted long chain alcohols, perfluoro-substituted long chain carboxylic acids and their derivatives, and Silwet silicone surfactants from OSi, Greenwich, Conn.) may also be included in the composition to improve the adhesion of the sealant to the microcups and provide a more flexible coating process. Other ingredients including crosslinking agents (e.g., bisazides such as 4,4′-diazidodiphenylmethane and 2,6-di-(4′-azidobenzal)-4-methylcyclohexanone), vulcanizers (e.g., 2-benzothiazolyl disulfide and tetramethylthiuram disulfide), multifunctional monomers or oligomers (e.g., hexanediol, diacrylates, trimethylolpropane, triacrylate, divinylbenzene, diallylphthalene), thermal initiators (e.g., dilauroryl peroxide, benzoyl peroxide) and photoinitiators (e.g., isopropyl thioxanthone (ITX), Irgacure 651 and Irgacure 369 from Ciba-Geigy) are also highly useful to enhance the physicomechanical properties of the sealing layer by crosslinking or polymerization reactions during or after the overcoating process. [0073]
  • The sealing composition is typically overcoated onto partially filled microcups and the overcoated microcups are dried at room temperature. The sealed microcups optionally may be post treated by UV radiation or thermal baking to further improve the barrier properties. The adhesion of the sealing layer to the microcups may also be improved by the post-curing reaction, likely due to the formation of an interpenetration network at the microcup-sealing layer inter-phase. [0074]
  • V. Preparation Of Electrophoretic Displays From The Microcup Array
  • The preferred process of preparing the electrophoretic cells is illustrated schematically in FIGS. [0075] 6A-6D.
  • As shown in FIG. 6A, the microcup array ([0076] 60) may be prepared by any of the alternative methods described in Section III above. The unfilled microcup array made by the methods described herein typically comprises a substrate web (63) upon which a base electrode (62) is deposited. The microcup walls (61) extend upward from the substrate (63) to form the open cups.
  • As shown in FIG. 6B, the microcups are filled with a suspension of the charged pigment particles ([0077] 65) in a colored dielectric solvent composition (64). In the example shown, the composition is the same in each cup, i.e., in a monochrome display. In carrying out the sealing process of the present invention, the microcups are preferably partially filled (to prevent overflow), which can be achieved by diluting the electrophoretic fluid with a volatile solvent (such as acetone, methyl ethyl ketone, isopropanol, hexane, and perfluoro solvent FC-33 from 3M Co.,) and allowing the volatile solvent to evaporate. When a high boiling point perfluoro solvent such as HT-200 (from Ausimont Colo., Thorofare, N.J.) is used as the continuous phase of the display fluid, a perfluoro volatile solvent such as FC-33 is particularly useful to control the level of partial filling.
  • As shown in FIG. 6C, after filling, the microcups are sealed with the sealing composition of the present invention to form a sealing layer ([0078] 66). The sealing composition is typically overcoated onto the partially filled microcups and dried on the display fluid. The sealed microcups optionally may be post treated by UV radiation or thermal baking to further improve the barrier properties.
  • As shown in FIG. 6D, the sealed array of electrophoretic microcup cells ([0079] 60) is laminated with a second conductor film (67), preferably by pre-coating the conductor (67) with an adhesive layer (68) which may be a pressure sensitive adhesive, a hot melt adhesive, or a heat, moisture, or radiation curable adhesive. The laminate adhesive may be post-cured by radiation such as UV through the top conductor film if the latter is transparent to the radiation.
  • VI. Preparation Of The Pigment/Solvent Suspension Or Dispersion Composition
  • As described herein with respect to the various embodiments of the EPD of the invention, the microcups are preferably filled with charged pigment particles dispersed in a dielectric solvent (e.g., solvent ([0080] 64) and pigment particles (65) in FIG. 6B.). The dispersion may be prepared according to methods well known in the art, such as U.S. Pat. Nos. 6,017,584, 5,914,806, 5,573,711, 5,403,518, 5,380,362, 4,680,103, 4,285,801, 4,093,534, 4,071,430, and 3,668,106. See also IEEE Trans. Electron Devices, ED-24, 827 (1977), and J. Appl. Phys. 49(9), 4820 (1978).
  • The charged pigment particles visually contrast with the medium in which the particles are suspended. The medium is a dielectric solvent which preferably has a low viscosity and a dielectric constant in the range of about 2 to about 30, preferably about 2 to about 15 for high particle mobility. Examples of suitable dielectric solvents include hydrocarbons such as decahydronaphthalene (DECALIN), 5-ethylidene-2-norbomene, fatty oils, paraffin oil, aromatic hydrocarbons such as toluene, xylene, phenylxylylethane, dodecylbenzene and alkylnaphthalenes, halogenated solvents such as, dichlorobenzotrifluoride, 3,4,5-trichlorobenzotrifluoride, chloropentafluoro-benzene, dichlorononane, pentachlorobenzene, and perfluoro solvents such as perfluorodecalin, perfluorotoluene, perfluoroxylene, FC-43, FC-70 and FC-5060 from 3M Company, St. Paul Minn., low molecular weight halogen containing polymers such as poly(perfluoropropylene oxide) from TCI America, Portland, Oregon, poly(chlorotrifluoroethylene) such as Halocarbon Oils from Halocarbon Product Corp., River Edge, N.J., perfluoropolyalkylether such as Galden, HT-200, and Fluorolink from Ausimont (Thorofare, N.J.) or Krytox Oils and Greases K-Fluid Series from DuPont, Del. In one preferred embodiment, poly(chlorotrifluoroethylene) is used as the dielectric solvent. In another preferred embodiment, poly(perfluoropropylene oxide) is used as the dielectric solvent. [0081]
  • A non-migrating fluid colorant may be formed from dyes or pigments. Nonionic azo and anthraquinone dyes are particularly useful. Examples of useful dyes include, but are not limited to: Oil Red EGN, Sudan Red, Sudan Blue, Oil Blue, Macrolex Blue, Solvent Blue 35, Pylam Spirit Black and Fast Spirit Black from Pylam Products Co., Arizona, Sudan Black B from Aldrich, Thermoplastic Black X-70 from BASF, and anthraquinone blue, anthraquinone yellow 114, anthraquinone red 111, 135, anthraquinone green 28 from Aldrich. Fluorinated dyes are particularly useful when perfluoro solvents are used. In the case of a pigment, the non-migrating pigment particles for generating the color of the medium may also be dispersed in the dielectric medium. These color particles are preferably uncharged. If the non-migrating pigment particles for generating color in the medium are charged, they preferably carry a charge which is opposite from that of the charged, migrating pigment particles. If both types of pigment particles carry the same charge, then they should have different charge density or different electrophoretic mobility. In any case, the dye or pigment for generating the non-migrating fluid colorant of the medium must be chemically stable and compatible with other components in the suspension. [0082]
  • The charged, migrating pigment particles may be organic or inorganic pigments, such as TiO[0083] 2, phthalocyanine blue, phthalocyanine green, diarylide yellow, diarylide AAOT Yellow, and quinacridone, azo, rhodamine, perylene pigment series from Sun Chemical, Hansa yellow G particles from Kanto Chemical, and Carbon Lampblack from Fisher. Submicron particle size is preferred. These particles should have acceptable optical characteristics, should not be swollen or softened by the dielectric solvent, and should be chemically stable. The resulting suspension must also be stable against sedimentation, creaming or flocculation under normal operating conditions.
  • The migrating pigment particles may exhibit a native charge, or may be charged explicitly using a charge control agent, or may acquire a charge when suspended in the dielectric solvent. Suitable charge control agents are well known in the art; they may be polymeric or non-polymeric in nature, and may also be ionic or non-ionic, including ionic surfactants such as Aerosol OT, sodium dodecylbenzenesulfonate, metal soaps, polybutene succinimide, maleic anhydride copolymers, vinylpyridine copolymers, vinylpyrrolidone copolymer (such as Ganex from International Specialty Products), (meth)acrylic acid copolymers, N,N-dimethylaminoethyl (meth)acrylate copolymers. Fluorosurfactants are particularly useful as charge controlling agents in perfluorocarbon solvents. These include FC fluorosurfactants such as FC-170C, FC-171, FC-176, FC430, FC431 and FC-740 from 3M Company and Zonyl fluorosurfactants such as Zonyl FSA, FSE, FSN, FSN-100, FSO, FSO-100, FSD and UR from Dupont. [0084]
  • Suitable charged pigment dispersions may be manufactured by any of the well-known methods including grinding, milling, attriting, microfluidizing, and ultrasonic techniques. For example, pigment particles in the form of a fine powder are added to the suspending solvent and the resulting mixture is ball milled or attrited for several hours to break up the highly agglomerated dry pigment powder into primary particles. Although less preferred, a dye or pigment for producing the non-migrating fluid colorant may be added to the suspension during the ball milling process. [0085]
  • Sedimentation or creaming of the pigment particles may be eliminated by microencapsulating the particles with suitable polymers to match the specific gravity to that of the dielectric solvent. Microencapsulation of the pigment particles may be accomplished chemically or physically. Typical microencapsulation processes include interfacial polymerization, in-situ polymerization, phase separation, coacervation, electrostatic coating, spray drying, fluidized bed coating and solvent evaporation. [0086]
  • For a black/white EPD, the suspension comprises charged white particles of titanium oxide (TiO[0087] 2) dispersed in a black dielectric solution containing a black dye or dispersed uncharged black particles. A black dye or dye mixture such as Pylam Spirit Black and Fast Spirit Black from Pylam Products Co. Arizona, Sudan Black B from Aldrich, Thermoplastic Black X-70 from BASF, or an insoluble black pigment such as carbon black may be used to generate the black color of the solvent. For other colored suspensions, there are many possibilities. For a subtractive color system, the charged TiO2 particles may be suspended in a dielectric fluid of cyan, yellow or magenta color. The cyan, yellow or magenta color may be generated via the use of a dye or a pigment. For an additive color system, the charged TiO2 particles may be suspended in a dielectric fluid of red, green or blue color generated also via the use of a dye or a pigment. The red, green, blue color system is preferred for most applications.
  • EXAMPLES Example 1 Microcup Formulation
  • 35 parts by weight of Ebecryl 600 (UCB), 40 parts of SR-399 (Sartomer), 10 parts of Ebecryl 4827 (UCB), 7 parts of Ebecryl 1360 (UCB), 8 parts of HDDA, (UCB), 0.05 parts of Irgacure 369 (Ciba Specialty Chemicals) and 0.01 parts of isopropyl thioxanthone (ITX from Aldrich) were mixed homogeneously and used for micro-embossing. [0088]
  • Example 2 Preparation of Microcup Array
  • A primer solution comprising of 5 parts of Ebecryl 830, 2.6 parts of SR-399 (from Sartomer), 1.8 parts of [0089] Ebecry 1701, 1 part of PMMA (Mw=350,000 from Aldrich), 0.5 parts of Irgacure 500, and 40 parts of methyl ethyl ketone (MEK) was coated onto a 2 mil 60 ohm/sq. ITO/PET film (from Sheldahl Inc., Minn.) using a #3 Myrad bar, dried, and UV cured by using the Zeta 7410 (5 w/cm2, from Loctite) exposure unit for 15 minutes in air. The microcup formulation prepared in Example 1 was coated onto the treated ITO/PET film with a targeted thickness of about 50 μm, embossed with a Ni—Co male mold having a 60 (length)×60 (width) μm repetitive protrusion square pattern with 25-50 μm protrusion height and 10 μm wide partition lines, UV cured from the PET side for 20 seconds, removed from the mold with a 2″ peeling bar at a speed of about 4-5 ft/min. Well-defined micro-cups with depth ranging from 25 to 50 μm were prepared by using male molds having corresponding protrusion heights. Microcup arrays of various dimension such as 70 (length)×70 (width)×35 (depth)×10 (partition), 100 (L)×100(W)×35(D)×10(P), and 100 (L)×100(W)×30(D)×10(P) μm were also prepared by the same procedure.
  • Example 3 Pigment Dispersion
  • 6.42 Grams of Ti Pure R706 were dispersed with a homogenizer into a solution containing 1.94 grams of Fluorolink D from Ausimont, 0.22 grams of Fluorolink 7004 also from Ausimont, 0.37 grams of a fluorinated copper phthalocyanine dye from 3M, 52.54 grams of perfluoro solvent HT-200 (Ausimont). [0090]
  • Example 4 Pigment Dispersion
  • The same as Example 3, except the Ti Pure R706 and Fluorolink were replaced by a polymer coated TiO[0091] 2 particles PC-9003 from Elimentis (Highstown, N.J.) and Krytox (Du Pont) respectively. Note: replacing 2 things, Ti & fluorolink, with 1 thing, TiO2 PC-90003 from 2 suppliers, elimentis & krytox??
  • Example 5 Microcup Sealing
  • The electrophoretic fluid prepared in Example 3 was diluted with a volatile perfluoro co-solvent FC-33 from 3M and coated onto a 35 microns deep microcup array prepared in Example 2. The volatile cosolvent was allowed to evaporate to expose a partially filled microcup array. A 7.5% solution of polyisoprene (97% cis, from Aldrich) in heptane was then overcoated onto the partially filled cups by a Universal Blade Applicator with an opening of 3 mil. The overcoated microcups were then dried at room temperature. A seamless sealing layer of about 7-8 μm thickness (dry) with acceptable adhesion and uniformity was formed on the microcup array. No observable entrapped air bubble in the sealed microcups was found under microscope. A second ITO/PET conductor precoated with an adhesive layer was laminated onto the sealed microcups. The electrophoretic cell showed satisfactory switching performance with good flexure resistance. No observable weight loss was found after being aged in a 66° C. oven for 5 days. [0092]
  • Example 6 Microcup Sealing
  • The same as Example 5, except the thickness of the polyisoprene layer was reduced to 4 microns by using a blade applicator of 2 mil opening. Pinholes and broken sealing layer were clearly observed under optical microscope. [0093]
  • Example 7-14 Microcup Sealing
  • The same as Example 5, except the sealing layer was replaced by polystyrene (Mw=, polyvinylbutyral (Butvar 72, from Solutia Inc., St. Louis, Mo.), and thermpoplastic elastomers such as SIS (Kraton D1107, 15% styrene), SBS (Kraton D1101, 31% styrene) SEBS (Kraton G1650 and FG1901, 30% styrene), and EPDM ([0094] Vistalon 6505, 57% ethylene). The results are summarized in Table 1. As it can be seen from Table 1, thermoplastic elastomers enabled thinner and higher quality sealing even on microcups of wide openings.
    TABLE 1
    Sealing of microcups
    Estimated
    Example dry Cup dimension Coating quality Coating quality
    No. Sealing Polymer Coating solution thickness (L × W × D × P), um (visual) (Microscopic)
    comparative Polyisoprene 7.5% in heptane 4-5 um 60 × 60 × 35 × 10 fair pinholes, broken
    5 (97% cis) layer
    comparative Polyisoprene 7.5% in heptane 7-8 um 60 × 60 × 35 × 10 good good
    6 (97% cis)
    comparative Polystyrene 30% in toluene 7-8 um 60 × 60 × 35 × 10 very poor, incomplete
    7 severe dewetting sealing, defects
    comparative Butvar 72 8.5% in 4-5 um 60 × 60 × 35 × 10 poor fair
    8 isopropanol reproducibility
    9 SIS (Kratone 4% in Heptane 4-5 um 70 × 70 × 35 × 10 good good
    D1107); 15%
    Styrene
    10 SIS (Kratone 4% in Heptane 3-4 um 100 × 100 × 30 × 10 good good
    D1107); 15%
    Styrene
    11 SBS (Kraton 10% in toluene/ 4-5 um 70 × 70 × 35 × 10 good good
    D1101), 31% heptane (20/80)
    styrene
    12 SEBS(Kraton FG 10% in xylene/ 4-5 um 70 × 70 × 35 × 10 good good
    1901, 30% Isopar E (5/95)
    styrene, 1.5%
    maleic anhrdride)
    13 SEBS(Kraton 5% in toluene/ 4-5 um 70 × 70 × 35 × 10 good good
    G1650, 30% heptane (5/95)
    styrene)
    14 EPDM (Vistalon 10% in Isopar E 4-5 um 70 × 70 × 35 × 10 good good
    6505, 57%
    ethylene)
  • While the present invention has been described with reference to the specific embodiments thereof, it should be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the true spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation, materials, compositions, processes, process step or steps, to the objective, spirit and scope of the present invention. All such modifications are intended to be within the scope of the claims appended hereto. [0095]
  • For example, it should be noted that the method of the invention for making microcups may also be used for manufacturing microcup arrays for liquid crystal displays. Similarly, the microcup selective filling, sealing and ITO laminating methods of the invention may also be employed in the manufacture of liquid crystal displays. [0096]
  • It is therefore wished that this invention to be defined by the scope of the appended claims as broadly as the prior art will permit, and in view of the specification if need be. [0097]

Claims (31)

What is claimed is:
1. A composition suitable for sealing electrophoretic cells, which composition comprises:
a) a solvent or solvent mixture which is immiscible with the display fluid contained within the cells and exhibits a specific gravity less than that of the display fluid, and
b) a thermoplastic elastomer.
2. The composition of claim 1 wherein said solvent or solvent mixture has a surface tension of lower than 35 dyne/cm.
3. The composition of claim 2 wherein said solvent or solvent mixture has a surface tension of lower than 30 dyne/cm.
4. The composition of claim I wherein said solvent or solvent mixture is selected from a group consisting of alkanes, cyclic alkanes, alkylbenzenes, alkyl esters and C3-5 alkyl alcohols.
5. The composition of claim 4 wherein said solvent is heptane, octane, nonane, cyclohexane, decalin, toluene, xylene, and their isomers, and mixtures thereof.
6. The composition of claim 1 wherein said thermoplastic elastomer is selected from a group consisting of ABA and (AB)n types of di -block, tri-block and multi-block copolymers, in which:
A is styrene, α-methylstyrene, ethylene, propylene or norbonen e,
B is butadiene, isoprene, ethylene, propylene, butylene, dimethylsiloxane or propylene sulfide, and A and B are not the same, and
n is≧1.
7. The composition of claim 6 wherein n is 1-10.
8. The composition of claim 6 wherein said thermoplastic elastomer is poly(styrene-b-butadiene), (poly(styrene-b-butadiene-b-styrene), poly(styrene-b-isoprene-b-styrene), poly(styrene-b-ethylene/butylenes-b-styrene), poly(styrene-b-dimethylsiloxane-b-styrene), poly((α-methylstyrene-b-isoprene), poly(α-methylstyrene-b-isoprene-b-α-methylstyrene), poly(α-methylstyrene-b-propylene sulfide-b-α-methylstyrene), poly((α-methylstyrene-b-dimethylsiloxane-b-α-methylstyrene), and their grafted co-polymers and derivatives thereof.
9. The composition of claim 1 wherein the thermoplastic elastomer is poly(ethylene-co-propylene-co-5-methylene-2-norbomene), (ethylene-propylene-diene terpolymer), and their grafted co-polymers and derivatives thereof.
10. The composition of claim 1, further comprising a thermoplastic material that is compatible with one of the blocks of the thermoplastic elastomer.
11. The composition of claim 10 wherein the thermoplastic material is selected from the group consisting of polystyrene and poly ((α-methylstyrene).
12. The composition of claim 1, further comprising a wetting agent.
13. The composition of claim 12 wherein said wetting agent is selected from a group consisting of surfactants, ZONYL fluorosurfactants, fluoroacrylates, fluoromethacrylates, fluoro-substituted long chain alcohols, perfluoro-substituted long chain carboxylic acids, SILWET silicone surfactants and their derivatives.
14. The composition of claim 1, further comprising one or more of the following agents: a crosslinking agent, a vulcanizer, a multifunctional monomer or oligomer, a thermal initiator or a photoinitiator.
15. The composition of claim 14 wherein said crosslinking agent is a bisazide such as 4,4′-diazidodiphenylmethane, or 2,6-di-(4′-azidobenzal)-4-methylcyclohexanone), and said vulcanizer is a disulfide such as 2-benzothiazolyl disulfide, or tetramethylthiuram disulfide.
16. A sealing process for the preparation of electrophoretic display, which process comprises:
a) filling an array of microcups with an electrophoretic fluid;
b) overcoating the electrophoretic fluid with a sealing composition comprising:
a solvent or solvent mixture which is immiscible with the display fluid contained within the cells and exhibits a specific gravity less than that of the display fluid,
thermoplastic elastomer; and
c) allowing the sealing composition to dry to form a sealing layer.
17. The process of claim 16, further comprising exposing the sealing layer to UV radiation or thermal baking.
18. The process of claim 16 wherein said solvent or solvent mixture has a surface tension of lower than 35 dyne/cm.
19. The process of claim 18 wherein said solvent or solvent mixture has a surface tension of lower than 30 dyne/cm.
20. The process of claim 16 wherein said solvent or solvent mixture is selected from a group consisting of alkanes, cyclic alkanes, alkylbenzenes, alkyl esters and C3-5 alkyl alcohols.
21. The process of claim 20 wherein said solvent is heptane, octane, nonane, cyclohexane, decalin, toluene, xylene, and their isomers, and mixtures thereof.
22. The process of claim 16 wherein said thermoplastic elastomer is selected from a group consisting of ABA and (AB)n types of di-block, tri-block and multi-block copolymers, in which:
A is styrene, α-methylstyrene, ethylene, propylene or norbonene,
B is butadiene, isoprene, ethylene, propylene, butylene, dimethylsiloxane or propylene sulfide, and A and B are not the same, and
n is≧1.
23. The process of claim 22 wherein n is 1-10.
24. The process of claim 16 wherein said thermoplastic elastomer is poly(styrene-b-butadiene), (poly(styrene-b-butadiene-b-styrene), poly(styrene-b-isoprene-b-styrene), poly(styrene-b-ethylene/butylenes-b-styrene), poly(styrene-b-dimethylsiloxane-b-styrene), poly(α-methylstyrene-b-isoprene), poly(α-mthylstyrene-b-isoprene-b-α-methylstyrene), poly(α-methylstyrene-b-propylene sulfide-b-α-methylstyrene), poly(α-methylstyrene-b-dimethylsiloxane-b-α-methylstyrene), and their grafted co-polymers and derivatives thereof.
25. The process of claim 16 wherein the thermoplastic elastomer is poly(ethylene-co-propylene-co-5-methylene-2-norbornene), (ethylene-propylene-diene terpolymer), and their grafted co-polymers and derivatives thereof.
26. The process of claim 16, further comprising a thermoplastic material that is compatible with one of the blocks of the thermoplastic elastomer.
27. The process of claim 26 wherein the thermoplastic material is selected from the group consisting of polystyrene and poly ((α-methylstyrene).
28. The process of claim 16, further comprising a wetting agent.
29. The process of claim 28 wherein said wetting agent is selected from a group consisting of surfactants, ZONYL fluorosurfactants, fluoroacrylates, fluoromethacrylates, fluoro-substituted long chain alcohols, perfluoro-substituted long chain carboxylic acids, SILWET silicone surfactants and their derivatives.
30. The process of claim 16, further comprising one or more of the following agents: a crosslinking agent, a vulcanizer, a multifunctional monomer or oligomer, a thermal initiator or a photoinitiator.
31. The process of claim 30 wherein said crosslinking agent is a bisazide such as 4,4′-diazidodiphenylmethane, or 2,6-di-(4′-azidobenzal)-4-methylcyclohexanone), and said vulcanizer is a disulfide such as 2-benzothiazolyl disulfide, or tetramethylthiuram disulfide.
US09/874,391 2001-06-04 2001-06-04 Composition and process for the sealing of microcups in roll-to-roll display manufacturing Abandoned US20020188053A1 (en)

Priority Applications (13)

Application Number Priority Date Filing Date Title
US09/874,391 US20020188053A1 (en) 2001-06-04 2001-06-04 Composition and process for the sealing of microcups in roll-to-roll display manufacturing
TW090123324A TWI301211B (en) 2001-06-04 2001-09-21 Composition and process for the sealing of microcups in roll-to-roll display manufacturing
CNB011364483A CN1237140C (en) 2001-06-04 2001-10-17 Components for sealing mini-cup in mfg. of roller-to-roller display device and method thereof
JP2003502091A JP4322663B2 (en) 2001-06-04 2002-06-03 Compositions and methods for sealing microcups in roll-to-roll display manufacturing
MXPA03011144A MXPA03011144A (en) 2001-06-04 2002-06-03 Composition and process for the sealing of microcups in roll-to-roll display manufacturing.
KR1020037015909A KR100859305B1 (en) 2001-06-04 2002-06-03 Composition and process for the sealing of microcups in roll-to-roll display manufacturing
PCT/US2002/017632 WO2002098977A1 (en) 2001-06-04 2002-06-03 Composition and process for the sealing of microcups in roll-to-roll display manufacturing
CA002448440A CA2448440A1 (en) 2001-06-04 2002-06-03 Composition and process for the sealing of microcups in roll-to-roll display manufacturing
EP02737371A EP1401953A1 (en) 2001-06-04 2002-06-03 Composition and process for the sealing of microcups in roll-to-roll display manufacturing
US10/222,297 US7005468B2 (en) 2001-06-04 2002-08-16 Composition and process for the sealing of microcups in roll-to-roll display manufacturing
US10/222,454 US7144942B2 (en) 2001-06-04 2002-08-16 Composition and process for the sealing of microcups in roll-to-roll display manufacturing
US10/310,681 US7205355B2 (en) 2001-06-04 2002-12-04 Composition and process for the manufacture of an improved electrophoretic display
US11/582,844 US8361356B2 (en) 2001-06-04 2006-10-17 Composition and process for the sealing of microcups in roll-to-roll display manufacturing

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US09/874,391 US20020188053A1 (en) 2001-06-04 2001-06-04 Composition and process for the sealing of microcups in roll-to-roll display manufacturing

Related Child Applications (3)

Application Number Title Priority Date Filing Date
US10/222,297 Division US7005468B2 (en) 2001-06-04 2002-08-16 Composition and process for the sealing of microcups in roll-to-roll display manufacturing
US10/222,454 Division US7144942B2 (en) 2001-06-04 2002-08-16 Composition and process for the sealing of microcups in roll-to-roll display manufacturing
US10/310,681 Continuation-In-Part US7205355B2 (en) 2001-06-04 2002-12-04 Composition and process for the manufacture of an improved electrophoretic display

Publications (1)

Publication Number Publication Date
US20020188053A1 true US20020188053A1 (en) 2002-12-12

Family

ID=25363637

Family Applications (3)

Application Number Title Priority Date Filing Date
US09/874,391 Abandoned US20020188053A1 (en) 2001-06-04 2001-06-04 Composition and process for the sealing of microcups in roll-to-roll display manufacturing
US10/222,454 Expired - Lifetime US7144942B2 (en) 2001-06-04 2002-08-16 Composition and process for the sealing of microcups in roll-to-roll display manufacturing
US10/222,297 Expired - Lifetime US7005468B2 (en) 2001-06-04 2002-08-16 Composition and process for the sealing of microcups in roll-to-roll display manufacturing

Family Applications After (2)

Application Number Title Priority Date Filing Date
US10/222,454 Expired - Lifetime US7144942B2 (en) 2001-06-04 2002-08-16 Composition and process for the sealing of microcups in roll-to-roll display manufacturing
US10/222,297 Expired - Lifetime US7005468B2 (en) 2001-06-04 2002-08-16 Composition and process for the sealing of microcups in roll-to-roll display manufacturing

Country Status (9)

Country Link
US (3) US20020188053A1 (en)
EP (1) EP1401953A1 (en)
JP (1) JP4322663B2 (en)
KR (1) KR100859305B1 (en)
CN (1) CN1237140C (en)
CA (1) CA2448440A1 (en)
MX (1) MXPA03011144A (en)
TW (1) TWI301211B (en)
WO (1) WO2002098977A1 (en)

Cited By (62)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020075556A1 (en) * 2000-03-03 2002-06-20 Rong-Chang Liang Electrophoretic display and novel process for its manufacture
US20020126249A1 (en) * 2001-01-11 2002-09-12 Rong-Chang Liang Transmissive or reflective liquid crystal display and novel process for its manufacture
US20020182544A1 (en) * 2000-01-11 2002-12-05 Sipix Imaging, Inc. Process for roll-to-roll manufacture of a display by synchronized photolithographic exposure on a substrate web
US20030035199A1 (en) * 2001-08-20 2003-02-20 Rong-Chang Liang Transflective electrophoretic display
US20030034950A1 (en) * 2001-08-17 2003-02-20 Rong-Chang Liang Electrophoretic display with dual mode switching
US20030043450A1 (en) * 2001-08-28 2003-03-06 Rong-Chang Liang Electrophoretic display with sub relief structure for high contrast ratio and improved shear and/or compression resistance
US20030152849A1 (en) * 2001-02-15 2003-08-14 Mary Chan-Park Process for roll-to-roll manufacture of a display by synchronized photolithographic exposure on a substrate web
US20040027643A1 (en) * 2002-05-30 2004-02-12 Canon Kabushiki Kaisha Dispersion for electrophoretic display, and electrophoretic display device
US20040032391A1 (en) * 2002-08-16 2004-02-19 Rong-Chang Liang Electrophoretic display with dual-mode switching
US20040032389A1 (en) * 2002-08-16 2004-02-19 Rong-Chang Liang Electrophoretic display with dual mode switching
US6751008B2 (en) 2000-03-03 2004-06-15 Sipix Imaging, Inc. Electrophoretic display and novel process for its manufacture
US20040112525A1 (en) * 2002-09-04 2004-06-17 Cheri Pereira Adhesive and sealing layers for electrophoretic displays
US20040120024A1 (en) * 2002-09-23 2004-06-24 Chen Huiyong Paul Electrophoretic displays with improved high temperature performance
US20040169912A1 (en) * 2002-10-31 2004-09-02 Rong-Chang Liang Electrophoretic display and novel process for its manufacture
US20040216837A1 (en) * 2002-09-04 2004-11-04 Cheri Pereira Adhesive and sealing layers for electrophoretic displays
US6831770B2 (en) 2000-03-03 2004-12-14 Sipix Imaging, Inc. Electrophoretic display and novel process for its manufacture
US6833943B2 (en) 2000-03-03 2004-12-21 Sipix Imaging, Inc. Electrophoretic display and novel process for its manufacture
US20050007651A1 (en) * 2000-03-03 2005-01-13 Rong-Chang Liang Electrophoretic display with sub relief structure for high contrast ratio and improved shear and/or compression resistance
US6850355B2 (en) 2001-07-27 2005-02-01 Sipix Imaging, Inc. Electrophoretic display with color filters
US6865012B2 (en) 2000-03-03 2005-03-08 Sipix Imaging, Inc. Electrophoretic display and novel process for its manufacture
US6885495B2 (en) 2000-03-03 2005-04-26 Sipix Imaging Inc. Electrophoretic display with in-plane switching
US20060033677A1 (en) * 2004-08-10 2006-02-16 Kenneth Faase Display device
US7042614B1 (en) 2004-11-17 2006-05-09 Hewlett-Packard Development Company, L.P. Spatial light modulator
EP1666965A1 (en) * 2003-09-12 2006-06-07 Bridgestone Corporation Image display panel production method and image display panel
US20060132579A1 (en) * 2004-12-20 2006-06-22 Palo Alto Research Center Incorporated Flexible electrophoretic-type display
US20060139724A1 (en) * 2002-09-10 2006-06-29 Rong-Chang Liang Electrochromic or electrodeposition display and novel process for their manufacture
US7141279B2 (en) 2002-11-25 2006-11-28 Sipix Imaging, Inc. Transmissive or reflective liquid crystal display and novel process for its manufacture
US20070036919A1 (en) * 2003-01-24 2007-02-15 Xiaojia Wang Adhesive and sealing layers for electrophoretic displays
US20070035497A1 (en) * 2002-09-23 2007-02-15 Chen Huiyong P Electrophoretic displays with improved high temperature performance
US7271947B2 (en) 2002-08-16 2007-09-18 Sipix Imaging, Inc. Electrophoretic display with dual-mode switching
US20070263277A1 (en) * 2001-08-17 2007-11-15 Rong-Chang Liang Electrophoretic display with dual mode switching
WO2008023309A1 (en) * 2006-08-21 2008-02-28 Koninklijke Philips Electronics N.V. A sealed cell structure
US7408696B2 (en) 2000-03-03 2008-08-05 Sipix Imaging, Inc. Three-dimensional electrophoretic displays
US20080220204A1 (en) * 2007-03-08 2008-09-11 Masaru Ohgaki Display panel, method of manufacturing a display panel, and display unit
US20080316564A1 (en) * 2005-12-22 2008-12-25 Eastman Kodak Company Display Devices
WO2009004265A2 (en) * 2007-07-04 2009-01-08 Essilor International (Compagnie Generale D'optique) Transparent film comprising a base film and a coating
US7656493B2 (en) 2007-07-31 2010-02-02 Arthur Alan R Pixel well electrodes
US20100033803A1 (en) * 2003-01-24 2010-02-11 Xiaojia Wang Adhesive and sealing layers for electrophoretic displays
US20100068514A1 (en) * 2008-09-18 2010-03-18 Tesa Se Method for encapsulating an electronic arrangement
US7715088B2 (en) 2000-03-03 2010-05-11 Sipix Imaging, Inc. Electrophoretic display
DE102008060113A1 (en) 2008-12-03 2010-07-29 Tesa Se Method for encapsulating an electronic device
US20110222141A1 (en) * 2010-03-10 2011-09-15 Seiko Epson Corporation Method for enclosing dispersion liquid containing electrophoretic particles and electrophoretic display unit
US8023071B2 (en) 2002-11-25 2011-09-20 Sipix Imaging, Inc. Transmissive or reflective liquid crystal display
EP2465426A1 (en) * 2010-12-20 2012-06-20 General Electric Company Biomedical sensor
US8282762B2 (en) 2001-01-11 2012-10-09 Sipix Imaging, Inc. Transmissive or reflective liquid crystal display and process for its manufacture
WO2013131707A1 (en) 2012-03-07 2013-09-12 Tesa Se Composite system for encapsulating electronic arrangements
US8582197B2 (en) 2000-03-03 2013-11-12 Sipix Imaging, Inc. Process for preparing a display panel
US8587857B2 (en) 2010-10-27 2013-11-19 Industrial Technology Research Institute Electro-wetting display device and non-polar color solution thereof
US8652565B2 (en) 2009-07-29 2014-02-18 Seiko Epson Corporation Sealing method of sealing dispersion liquid containing and electrophoretic particles, and electrophoretic display
US20170108740A1 (en) * 2014-04-04 2017-04-20 Lg Chem, Ltd. Liquid crystal element
US20170166332A1 (en) * 2015-12-10 2017-06-15 Nova Chemicals (International) S.A. Hot Fill Process With Closures Made From High Density Polyethylene Compositions
US20170166430A1 (en) * 2015-12-09 2017-06-15 Nova Chemicals (International) S.A. Hot Fill Process With Closures Made From High Density Unimodal Polyethylene
CN107111176A (en) * 2015-02-16 2017-08-29 株式会社Lg化学 Liquid-crystal apparatus
US9989798B2 (en) 2014-06-27 2018-06-05 Lg Display Co., Ltd. Light controlling apparatus, method of fabricating the light controlling apparatus and transparent display device including the light controlling apparatus with transparent mode and light shielding mode
US20180210312A1 (en) * 2017-01-20 2018-07-26 E Ink California, Llc Color organic pigments and electrophoretic display media containing the same
US10087344B2 (en) 2015-10-30 2018-10-02 E Ink Corporation Methods for sealing microcell containers with phenethylamine mixtures
WO2020033787A1 (en) 2018-08-10 2020-02-13 E Ink California, Llc Driving waveforms for switchable light-collimating layer including bistable electrophoretic fluid
WO2020033175A1 (en) 2018-08-10 2020-02-13 E Ink California, Llc Switchable light-collimating layer including bistable electrophoretic fluid
US10585325B2 (en) 2017-03-09 2020-03-10 E Ink California, Llc Photo-thermally induced polymerization inhibitors for electrophoretic media
US10698265B1 (en) 2017-10-06 2020-06-30 E Ink California, Llc Quantum dot film
US11048124B2 (en) 2019-09-06 2021-06-29 Au Optronics Corporation Liquid crystal panel and manufacturing method thereof
US11314098B2 (en) 2018-08-10 2022-04-26 E Ink California, Llc Switchable light-collimating layer with reflector

Families Citing this family (148)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8361356B2 (en) * 2001-06-04 2013-01-29 Sipix Imaging, Inc. Composition and process for the sealing of microcups in roll-to-roll display manufacturing
US7244470B2 (en) * 2001-07-10 2007-07-17 Cantega Technologies Inc. Protection of electrical power systems
US7177066B2 (en) * 2003-10-24 2007-02-13 Sipix Imaging, Inc. Electrophoretic display driving scheme
GB0327215D0 (en) * 2003-11-22 2003-12-24 Koninkl Philips Electronics Nv Active matrix display device and method of producing the same
US7279064B2 (en) * 2003-12-18 2007-10-09 Palo Alto Research Center, Incorporated Method of sealing an array of cell microstructures using microencapsulated adhesive
US9307648B2 (en) 2004-01-21 2016-04-05 Microcontinuum, Inc. Roll-to-roll patterning of transparent and metallic layers
US9039401B2 (en) 2006-02-27 2015-05-26 Microcontinuum, Inc. Formation of pattern replicating tools
US8643595B2 (en) * 2004-10-25 2014-02-04 Sipix Imaging, Inc. Electrophoretic display driving approaches
US8111368B2 (en) * 2006-02-28 2012-02-07 Hewlett-Packard Development Company, L.P. Liquid crystal display
US8029558B2 (en) * 2006-07-07 2011-10-04 Abbott Cardiovascular Systems, Inc. Stent and catheter assembly and method for treating bifurcations
US8830561B2 (en) 2006-07-18 2014-09-09 E Ink California, Llc Electrophoretic display
US20080020007A1 (en) * 2006-07-18 2008-01-24 Zang Hongmei Liquid-containing film structure
US20150005720A1 (en) 2006-07-18 2015-01-01 E Ink California, Llc Electrophoretic display
WO2008014519A2 (en) * 2006-07-28 2008-01-31 Microcontinuum, Inc. Addressable flexible patterns
FR2910642B1 (en) * 2006-12-26 2009-03-06 Essilor Int TRANSPARENT OPTICAL COMPONENT WITH TWO CELL ARRAYS
US8940117B2 (en) 2007-02-27 2015-01-27 Microcontinuum, Inc. Methods and systems for forming flexible multilayer structures
US8274472B1 (en) 2007-03-12 2012-09-25 Sipix Imaging, Inc. Driving methods for bistable displays
US8243013B1 (en) 2007-05-03 2012-08-14 Sipix Imaging, Inc. Driving bistable displays
US20080303780A1 (en) 2007-06-07 2008-12-11 Sipix Imaging, Inc. Driving methods and circuit for bi-stable displays
KR20090061869A (en) * 2007-12-12 2009-06-17 한국전자통신연구원 Electrophoresis display and method of forming the same
EP2245506A4 (en) * 2008-02-26 2011-05-11 Hewlett Packard Development Co Electrophoretic display device
US8462102B2 (en) * 2008-04-25 2013-06-11 Sipix Imaging, Inc. Driving methods for bistable displays
CN102113046B (en) * 2008-08-01 2014-01-22 希毕克斯影像有限公司 Gamma adjustment with error diffusion for electrophoretic displays
WO2010022294A2 (en) 2008-08-20 2010-02-25 Ravenbrick, Llc Methods for fabricating thermochromic filters
KR101787767B1 (en) 2009-04-10 2017-10-18 라벤브릭 엘엘씨 Thermally switched optical filter incorporating a guest-host architecture
US9460666B2 (en) * 2009-05-11 2016-10-04 E Ink California, Llc Driving methods and waveforms for electrophoretic displays
US8436844B2 (en) * 2009-06-18 2013-05-07 Roche Diagnostics Operations, Inc. Bi-stable display fail safes and devices incorporating the same
JP5267955B2 (en) * 2010-01-27 2013-08-21 大日本印刷株式会社 Method for manufacturing electrophoretic display device
CN103080443B (en) 2010-06-01 2015-11-25 雷文布里克有限责任公司 Multi-use architecture component
KR101209550B1 (en) * 2010-09-09 2012-12-07 주식회사 이미지앤머터리얼스 Electrophoretic desplay, image sheet and method of fabricating the same
US8845912B2 (en) 2010-11-22 2014-09-30 Microcontinuum, Inc. Tools and methods for forming semi-transparent patterning masks
CN104536231B (en) * 2011-05-23 2017-10-10 京东方科技集团股份有限公司 Electrochromic display device, its preparation method, cathode construction and micro- lattice array
CA2847185A1 (en) 2011-09-01 2013-03-07 Ravenbrick, Llc Thermotropic optical shutter incorporating coatable polarizers
TW201327517A (en) * 2011-12-21 2013-07-01 Fitipower Integrated Tech Inc Electronic device and method for switching between a first display unit and a second display unit
TWI494679B (en) 2012-01-09 2015-08-01 Sipix Imaging Inc Electrophoretic display fluid
JP5929239B2 (en) * 2012-01-27 2016-06-01 セイコーエプソン株式会社 Electrophoretic dispersion liquid, electrophoretic sheet, electrophoretic device, and electronic apparatus
KR101391373B1 (en) 2012-02-24 2014-05-07 최명준 Composition for encapsulating a display device, method of encapsulating a display device, and a display panel
US9589797B2 (en) 2013-05-17 2017-03-07 Microcontinuum, Inc. Tools and methods for producing nanoantenna electronic devices
JP2015018061A (en) * 2013-07-10 2015-01-29 セイコーエプソン株式会社 Electrophoresis device, method for manufacturing the electrophoresis device, and electronic apparatus
US9188829B2 (en) * 2013-09-09 2015-11-17 E Ink California, Llc Electrophoretic display film for anti-counterfeit application
JP2015075517A (en) * 2013-10-07 2015-04-20 セイコーエプソン株式会社 Electrophoretic display device and manufacturing method of the same
EP3470915B1 (en) 2013-10-22 2021-08-25 E Ink Corporation A wide operating temperature range electrophoretic device
US10317767B2 (en) 2014-02-07 2019-06-11 E Ink Corporation Electro-optic display backplane structure with drive components and pixel electrodes on opposed surfaces
CN103941512B (en) * 2014-04-11 2016-08-17 京东方科技集团股份有限公司 The manufacture method of pixel dividing wall, array base palte and AMECD
KR102314707B1 (en) * 2014-06-27 2021-10-20 엘지디스플레이 주식회사 Light controlling apparatus, method of fabricating the light controlling apparatus, and transparent display device including the light controlling appratus
TWI613498B (en) * 2014-06-27 2018-02-01 電子墨水加利福尼亞有限責任公司 Anisotropic conductive dielectric layer for electrophoretic display
JP6571276B2 (en) 2015-08-31 2019-09-04 イー インク コーポレイション Erasing drawing devices electronically
CN113241041B (en) 2015-09-16 2024-01-05 伊英克公司 Apparatus and method for driving display
US11657774B2 (en) 2015-09-16 2023-05-23 E Ink Corporation Apparatus and methods for driving displays
US10803813B2 (en) 2015-09-16 2020-10-13 E Ink Corporation Apparatus and methods for driving displays
TWI631542B (en) 2015-11-18 2018-08-01 美商電子墨水股份有限公司 Electro-optic displays
US10209530B2 (en) 2015-12-07 2019-02-19 E Ink Corporation Three-dimensional display
CN105500710B (en) * 2015-12-31 2019-01-18 珠海天威飞马打印耗材有限公司 Three-dimensionally shaped material, DLP three-dimensional printer and its forming method
CN108474991B (en) * 2016-01-17 2021-04-20 伊英克加利福尼亚有限责任公司 Polyhydroxy compositions for sealing electrophoretic displays
WO2017123570A1 (en) 2016-01-17 2017-07-20 E Ink California, Llc Surfactants for improving electrophoretic media performance
JP6739540B2 (en) 2016-03-09 2020-08-12 イー インク コーポレイション Method for driving an electro-optical display
US10593272B2 (en) 2016-03-09 2020-03-17 E Ink Corporation Drivers providing DC-balanced refresh sequences for color electrophoretic displays
US10670892B2 (en) 2016-04-22 2020-06-02 E Ink Corporation Foldable electro-optic display apparatus
WO2018060016A1 (en) * 2016-09-27 2018-04-05 Basf Se Star-shaped and triblock polymers with enhanced crosslinkability
US10503041B2 (en) 2016-11-30 2019-12-10 E Ink Corporation Laminated electro-optic displays and methods of making same
US10509294B2 (en) 2017-01-25 2019-12-17 E Ink Corporation Dual sided electrophoretic display
KR102187730B1 (en) 2017-02-15 2020-12-07 이 잉크 캘리포니아 엘엘씨 Polymer additives used in color electrophoretic display media
WO2018160546A1 (en) 2017-02-28 2018-09-07 E Ink Corporation Writeable electrophoretic displays including sensing circuits and styli configured to interact with sensing circuits
KR102174880B1 (en) 2017-03-06 2020-11-05 이 잉크 코포레이션 How to render color images
US9995987B1 (en) 2017-03-20 2018-06-12 E Ink Corporation Composite particles and method for making the same
WO2018183240A1 (en) 2017-03-28 2018-10-04 E Ink Corporation Porous backplane for electro-optic display
EP3607543A4 (en) 2017-04-04 2020-12-16 E Ink Corporation Methods for driving electro-optic displays
US10495941B2 (en) 2017-05-19 2019-12-03 E Ink Corporation Foldable electro-optic display including digitization and touch sensing
US11404013B2 (en) 2017-05-30 2022-08-02 E Ink Corporation Electro-optic displays with resistors for discharging remnant charges
JP2020522741A (en) 2017-05-30 2020-07-30 イー インク コーポレイション Electro-optic display
CN110603484B (en) 2017-06-16 2023-05-02 伊英克公司 Electro-optic medium comprising encapsulated pigments in a gelatin binder
JP6887029B2 (en) 2017-06-16 2021-06-16 イー インク コーポレイション Variable transmittance electrophoresis device
US10802373B1 (en) 2017-06-26 2020-10-13 E Ink Corporation Reflective microcells for electrophoretic displays and methods of making the same
US10921676B2 (en) 2017-08-30 2021-02-16 E Ink Corporation Electrophoretic medium
CN111133501A (en) 2017-09-12 2020-05-08 伊英克公司 Method for driving electro-optic display
US11721295B2 (en) 2017-09-12 2023-08-08 E Ink Corporation Electro-optic displays, and methods for driving same
US10824042B1 (en) 2017-10-27 2020-11-03 E Ink Corporation Electro-optic display and composite materials having low thermal sensitivity for use therein
US11079651B2 (en) 2017-12-15 2021-08-03 E Ink Corporation Multi-color electro-optic media
CN116243504A (en) 2017-12-19 2023-06-09 伊英克公司 Application of electro-optic display
JP7001217B2 (en) 2017-12-22 2022-01-19 イー インク コーポレイション Electrophoresis display device and electronic device
US11248122B2 (en) 2017-12-30 2022-02-15 E Ink Corporation Pigments for electrophoretic displays
RU2754485C1 (en) 2018-01-22 2021-09-02 Е Инк Корпорэйшн Electrooptical displays and methods for actuation thereof
US11143929B2 (en) 2018-03-09 2021-10-12 E Ink Corporation Reflective electrophoretic displays including photo-luminescent material and color filter arrays
US11175561B1 (en) 2018-04-12 2021-11-16 E Ink Corporation Electrophoretic display media with network electrodes and methods of making and using the same
TWI795334B (en) 2018-05-17 2023-03-01 美商伊英克加利福尼亞有限責任公司 Method for producing a display and method of integrating electrophoretic displays
JP7190515B2 (en) 2018-06-28 2022-12-15 イー インク コーポレイション Driving method for variable permeation electrophoresis medium
TWI727374B (en) 2018-07-25 2021-05-11 美商電子墨水股份有限公司 Flexible transparent intumescent coatings and composites incorporating the same
KR20210018523A (en) 2018-08-07 2021-02-17 이 잉크 코포레이션 Flexible encapsulated electro-optical media
US11364566B2 (en) 2018-08-09 2022-06-21 The United States Of America As Represented By The Secretary Of The Army Complex laser folding and fabrication
US11493821B2 (en) 2018-08-14 2022-11-08 E Ink California, Llc Piezo electrophoretic display
WO2020060797A1 (en) 2018-09-20 2020-03-26 E Ink Corporation Three-dimensional display apparatuses
US11656522B2 (en) 2018-09-28 2023-05-23 E Ink Corporation Solar temperature regulation system for a fluid
CN112740087B (en) 2018-10-01 2023-07-04 伊英克公司 Electro-optic fiber and method for manufacturing same
US11635640B2 (en) 2018-10-01 2023-04-25 E Ink Corporation Switching fibers for textiles
JP7108794B2 (en) 2018-10-30 2022-07-28 イー インク コーポレイション Electro-optical media and writable devices incorporating same
KR20230128588A (en) 2018-11-09 2023-09-05 이 잉크 코포레이션 Electro-optic displays
JP7158584B2 (en) 2018-11-30 2022-10-21 イー インク コーポレイション Pressure-sensitive write medium with electrophoretic material
US11402719B2 (en) 2018-12-11 2022-08-02 E Ink Corporation Retroreflective electro-optic displays
CN113168063A (en) 2018-12-12 2021-07-23 伊英克公司 Edible electrode and use in electro-optic displays
US10823373B2 (en) 2018-12-17 2020-11-03 E Ink Corporation Light emitting device including variable transmission film to control intensity and pattern
WO2020131799A1 (en) 2018-12-17 2020-06-25 E Ink Corporation Anisotropically conductive moisture barrier films and electro-optic assemblies containing the same
US11521565B2 (en) 2018-12-28 2022-12-06 E Ink Corporation Crosstalk reduction for electro-optic displays
CN113228151A (en) 2018-12-30 2021-08-06 伊英克加利福尼亚有限责任公司 Electro-optic display
US11567388B2 (en) 2019-02-25 2023-01-31 E Ink Corporation Composite electrophoretic particles and variable transmission films containing the same
US11602806B2 (en) 2019-02-28 2023-03-14 The United States Of America As Represented By The Secretary Of The Army Method and apparatus for performing contactless laser fabrication and propulsion of freely moving structures
US20220154054A1 (en) * 2019-02-28 2022-05-19 Lg Chem, Ltd Encapsulation film
US11456397B2 (en) 2019-03-12 2022-09-27 E Ink Corporation Energy harvesting electro-optic displays
JP2022527696A (en) 2019-03-29 2022-06-03 イー インク コーポレイション Electro-optic display and how to drive it
WO2020219274A1 (en) 2019-04-24 2020-10-29 E Ink Corporation Electrophoretic particles, media, and displays and processes for the production thereof
WO2020223041A1 (en) 2019-04-30 2020-11-05 E Ink Corporation Connectors for electro-optic displays
WO2020226990A1 (en) 2019-05-07 2020-11-12 E Ink Corporation Driving methods for a variable light transmission device
US11761123B2 (en) 2019-08-07 2023-09-19 E Ink Corporation Switching ribbons for textiles
EP4022389A4 (en) 2019-08-26 2023-08-16 E Ink Corporation Electro-optic device comprising an identification marker
GB201914105D0 (en) 2019-09-30 2019-11-13 Vlyte Innovations Ltd A see-through electrophoretic device having a visible grid
US11827816B2 (en) 2019-10-07 2023-11-28 E Ink Corporation Adhesive composition comprising a polyurethane and a cationic dopant
EP4059006A4 (en) 2019-11-14 2023-12-06 E Ink Corporation Methods for driving electro-optic displays
KR20220069973A (en) 2019-11-14 2022-05-27 이 잉크 코포레이션 Electro-optic medium comprising oppositely charged particles and variable transmission device comprising same
KR20220075422A (en) 2019-11-18 2022-06-08 이 잉크 코포레이션 Methods for driving electro-optic displays
EP4078276A1 (en) 2019-12-17 2022-10-26 E Ink Corporation Autostereoscopic devices and methods for producing 3d images
GB2593150A (en) 2020-03-05 2021-09-22 Vlyte Ltd A light modulator having bonded structures embedded in its viewing area
WO2021247450A1 (en) 2020-05-31 2021-12-09 E Ink Corporation Electro-optic displays, and methods for driving same
WO2021247470A1 (en) 2020-06-03 2021-12-09 E Ink Corporation Foldable electrophoretic display module including non-conductive support plate
CA3177382A1 (en) 2020-06-05 2021-12-09 E Ink California, Llc Electrophoretic display device
US11520202B2 (en) 2020-06-11 2022-12-06 E Ink Corporation Electro-optic displays, and methods for driving same
US11846863B2 (en) 2020-09-15 2023-12-19 E Ink Corporation Coordinated top electrode—drive electrode voltages for switching optical state of electrophoretic displays using positive and negative voltages of different magnitudes
AU2021344334B2 (en) 2020-09-15 2023-12-07 E Ink Corporation Improved driving voltages for advanced color electrophoretic displays and displays with improved driving voltages
EP4214574A1 (en) 2020-09-15 2023-07-26 E Ink Corporation Four particle electrophoretic medium providing fast, high-contrast optical state switching
US11450262B2 (en) 2020-10-01 2022-09-20 E Ink Corporation Electro-optic displays, and methods for driving same
KR20230078806A (en) 2020-11-02 2023-06-02 이 잉크 코포레이션 Enhanced push-pull (EPP) waveforms for achieving primary color sets in multi-color electrophoretic displays
EP4237909A1 (en) 2020-11-02 2023-09-06 E Ink Corporation Driving sequences to remove prior state information from color electrophoretic displays
US11657772B2 (en) 2020-12-08 2023-05-23 E Ink Corporation Methods for driving electro-optic displays
KR20230155569A (en) 2021-04-29 2023-11-10 이 잉크 코포레이션 Resolution drive sequence for four-particle electrophoresis display
US11580920B2 (en) 2021-05-25 2023-02-14 E Ink California, Llc Synchronized driving waveforms for four-particle electrophoretic displays
AU2022339893A1 (en) 2021-09-06 2024-01-25 E Ink Corporation Method for driving electrophoretic display device
WO2023043714A1 (en) 2021-09-14 2023-03-23 E Ink Corporation Coordinated top electrode - drive electrode voltages for switching optical state of electrophoretic displays using positive and negative voltages of different magnitudes
US11830448B2 (en) 2021-11-04 2023-11-28 E Ink Corporation Methods for driving electro-optic displays
US11922893B2 (en) 2021-12-22 2024-03-05 E Ink Corporation High voltage driving using top plane switching with zero voltage frames between driving frames
WO2023122142A1 (en) 2021-12-22 2023-06-29 E Ink Corporation Methods for driving electro-optic displays
TW202343004A (en) 2021-12-27 2023-11-01 美商電子墨水股份有限公司 Methods for measuring electrical properties of electro-optic displays
US20230213790A1 (en) 2022-01-04 2023-07-06 E Ink Corporation Electrophoretic media comprising electrophoretic particles and a combination of charge control agents
US20230273495A1 (en) 2022-02-28 2023-08-31 E Ink California, Llc Piezo-electrophoretic film including patterned piezo polarities for creating images via electrophoretic media
WO2023164446A1 (en) 2022-02-28 2023-08-31 E Ink California, Llc Piezoelectric film including ionic liquid and electrophoretic display film including the piezoelectric film
US11830449B2 (en) 2022-03-01 2023-11-28 E Ink Corporation Electro-optic displays
US20230324761A1 (en) 2022-04-08 2023-10-12 E Ink California, Llc Water-resistant sealing layer for sealing microcells of electro-optic devices
WO2023200859A1 (en) 2022-04-13 2023-10-19 E Ink Corporation Display material including patterned areas of encapsulated electrophoretic media
US20230351977A1 (en) 2022-04-27 2023-11-02 E Ink Corporation Color displays configured to convert rgb image data for display on advanced color electronic paper
US20240004255A1 (en) 2022-07-01 2024-01-04 E Ink Corporation Sealing Films and Sealing Compositions for Sealing Microcells of Electro-Optic Devices
US20240078981A1 (en) 2022-08-25 2024-03-07 E Ink Corporation Transitional driving modes for impulse balancing when switching between global color mode and direct update mode for electrophoretic displays

Family Cites Families (51)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3612758A (en) 1969-10-03 1971-10-12 Xerox Corp Color display device
US3668106A (en) * 1970-04-09 1972-06-06 Matsushita Electric Ind Co Ltd Electrophoretic display device
US4093534A (en) * 1974-02-12 1978-06-06 Plessey Handel Und Investments Ag Working fluids for electrophoretic image display devices
US4071430A (en) * 1976-12-06 1978-01-31 North American Philips Corporation Electrophoretic image display having an improved switching time
US4411115A (en) * 1978-04-05 1983-10-25 Usm Corporation Spacer frames for multi-pane glazing units
US4285801A (en) * 1979-09-20 1981-08-25 Xerox Corporation Electrophoretic display composition
US4721739A (en) * 1982-07-01 1988-01-26 Bic Corp. Erasable ink compositions
JPS59171930A (en) 1983-03-18 1984-09-28 Matsushita Electric Ind Co Ltd Electrophoresis display element
US4741988A (en) * 1985-05-08 1988-05-03 U.S. Philips Corp. Patterned polyimide film, a photosensitive polyamide acid derivative and an electrophoretic image-display cell
US4680103A (en) * 1986-01-24 1987-07-14 Epid. Inc. Positive particles in electrophoretic display device composition
US5360026A (en) * 1986-12-04 1994-11-01 Oral Logic, Inc. Tooth cleaning device and method
US4881996A (en) * 1988-02-22 1989-11-21 Ashland Oil, Inc. Splice adhesive for EDPM roofing and splicing method employing same
US5326865A (en) * 1990-06-08 1994-07-05 Hercules Incorporated Arylazo and poly(arylazo) dyes having at least one core radical selected from naphthyl or anthracyl and having at least one 2,3-dihydro-1,3-dialkyl perimidine substituent
US5124405A (en) * 1990-07-27 1992-06-23 Shell Oil Company Method of chemically crosslinking unsaturated polymers
US5352531A (en) * 1990-12-20 1994-10-04 Ozko, Inc. Coating solution for treating basement walls
CA2114650C (en) 1991-08-29 1999-08-10 Frank J. Disanto Electrophoretic display panel with internal mesh background screen
US5234987A (en) * 1992-07-06 1993-08-10 Adco Products, Inc. Solvent-based adhesive composition for roofing membranes
US5279511A (en) 1992-10-21 1994-01-18 Copytele, Inc. Method of filling an electrophoretic display
JPH08510790A (en) 1993-05-21 1996-11-12 コピイテル,インコーポレイテッド Method for preparing electrophoretic dispersion containing two types of particles having different colors and opposite charges
US5380362A (en) * 1993-07-16 1995-01-10 Copytele, Inc. Suspension for use in electrophoretic image display systems
US5403518A (en) * 1993-12-02 1995-04-04 Copytele, Inc. Formulations for improved electrophoretic display suspensions and related methods
US5492963A (en) * 1994-01-11 1996-02-20 Lord Corporation Overcoat and adhesive compositions based on chlorinated polyolefins having high chlorine contents
US5699097A (en) 1994-04-22 1997-12-16 Kabushiki Kaisha Toshiba Display medium and method for display therewith
JPH10501301A (en) * 1994-05-26 1998-02-03 コピイテル,インコーポレイテッド Fluorinated dielectric suspensions for electrophoretic image displays and related methods
DE19517915A1 (en) * 1995-05-16 1996-11-21 Elringklinger Gmbh Process for producing elastomer-coated metal gaskets
US6120839A (en) * 1995-07-20 2000-09-19 E Ink Corporation Electro-osmotic displays and materials for making the same
US6017584A (en) * 1995-07-20 2000-01-25 E Ink Corporation Multi-color electrophoretic displays and materials for making the same
US6120588A (en) * 1996-07-19 2000-09-19 E Ink Corporation Electronically addressable microencapsulated ink and display thereof
US5932648A (en) * 1995-09-15 1999-08-03 Shell Oil Company Low VOC, high solids fumigation adhesive composition
GB2314845A (en) * 1996-06-24 1998-01-14 Shell Int Research Primer composition
US5930026A (en) * 1996-10-25 1999-07-27 Massachusetts Institute Of Technology Nonemissive displays and piezoelectric power supplies therefor
US6294257B1 (en) * 1997-03-11 2001-09-25 Zeon Corporation Conductive elastomer film, method for production thereof, and conductive elastomer composition
US5961804A (en) * 1997-03-18 1999-10-05 Massachusetts Institute Of Technology Microencapsulated electrophoretic display
US6067185A (en) 1997-08-28 2000-05-23 E Ink Corporation Process for creating an encapsulated electrophoretic display
WO1999023174A1 (en) * 1997-10-31 1999-05-14 Cabot Corporation Particles having an attached stable free radical, polymerized modified particles, and methods of making the same
GB2332202A (en) * 1997-12-09 1999-06-16 Courtaulds Coatings Curable epoxy resin compositions
US5914806A (en) * 1998-02-11 1999-06-22 International Business Machines Corporation Stable electrophoretic particles for displays
WO1999056171A1 (en) 1998-04-27 1999-11-04 E-Ink Corporation Shutter mode microencapsulated electrophoretic display
US6184856B1 (en) * 1998-09-16 2001-02-06 International Business Machines Corporation Transmissive electrophoretic display with laterally adjacent color cells
US6312304B1 (en) * 1998-12-15 2001-11-06 E Ink Corporation Assembly of microencapsulated electronic displays
US6327072B1 (en) * 1999-04-06 2001-12-04 E Ink Corporation Microcell electrophoretic displays
JP2001056653A (en) * 1999-06-11 2001-02-27 Ricoh Co Ltd Display liquid for electrophoresis display, display particles, display medium utilizing the foregoing same, display device, display method, display, recording sheet, display and reversible display type signboard
JP5394601B2 (en) * 1999-07-01 2014-01-22 イー インク コーポレイション Electrophoretic medium provided with spacer
US6337761B1 (en) * 1999-10-01 2002-01-08 Lucent Technologies Inc. Electrophoretic display and method of making the same
US6933098B2 (en) * 2000-01-11 2005-08-23 Sipix Imaging Inc. Process for roll-to-roll manufacture of a display by synchronized photolithographic exposure on a substrate web
US6930818B1 (en) 2000-03-03 2005-08-16 Sipix Imaging, Inc. Electrophoretic display and novel process for its manufacture
US6788449B2 (en) * 2000-03-03 2004-09-07 Sipix Imaging, Inc. Electrophoretic display and novel process for its manufacture
US6750844B2 (en) * 2000-06-14 2004-06-15 Canon Kabushiki Kaisha Electrophoretic display device and process for production thereof
TW527529B (en) * 2001-07-27 2003-04-11 Sipix Imaging Inc An improved electrophoretic display with color filters
TW539928B (en) * 2001-08-20 2003-07-01 Sipix Imaging Inc An improved transflective electrophoretic display
TWI308231B (en) * 2001-08-28 2009-04-01 Sipix Imaging Inc Electrophoretic display

Cited By (127)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020182544A1 (en) * 2000-01-11 2002-12-05 Sipix Imaging, Inc. Process for roll-to-roll manufacture of a display by synchronized photolithographic exposure on a substrate web
US6933098B2 (en) 2000-01-11 2005-08-23 Sipix Imaging Inc. Process for roll-to-roll manufacture of a display by synchronized photolithographic exposure on a substrate web
US20040196527A1 (en) * 2000-03-03 2004-10-07 Rong-Chang Liang Electrophoretic display and novel process for its manufacture
US6751008B2 (en) 2000-03-03 2004-06-15 Sipix Imaging, Inc. Electrophoretic display and novel process for its manufacture
US6865012B2 (en) 2000-03-03 2005-03-08 Sipix Imaging, Inc. Electrophoretic display and novel process for its manufacture
US7408696B2 (en) 2000-03-03 2008-08-05 Sipix Imaging, Inc. Three-dimensional electrophoretic displays
US8582197B2 (en) 2000-03-03 2013-11-12 Sipix Imaging, Inc. Process for preparing a display panel
US20050007651A1 (en) * 2000-03-03 2005-01-13 Rong-Chang Liang Electrophoretic display with sub relief structure for high contrast ratio and improved shear and/or compression resistance
US6833943B2 (en) 2000-03-03 2004-12-21 Sipix Imaging, Inc. Electrophoretic display and novel process for its manufacture
US6987605B2 (en) 2000-03-03 2006-01-17 Sipix Imaging, Inc. Transflective electrophoretic display
US7715088B2 (en) 2000-03-03 2010-05-11 Sipix Imaging, Inc. Electrophoretic display
US6867898B2 (en) 2000-03-03 2005-03-15 Sipix Imaging Inc. Electrophoretic display and novel process for its manufacture
US6947202B2 (en) 2000-03-03 2005-09-20 Sipix Imaging, Inc. Electrophoretic display with sub relief structure for high contrast ratio and improved shear and/or compression resistance
US6859302B2 (en) 2000-03-03 2005-02-22 Sipix Imaging, Inc. Electrophoretic display and novel process for its manufacture
US20020075556A1 (en) * 2000-03-03 2002-06-20 Rong-Chang Liang Electrophoretic display and novel process for its manufacture
US6831770B2 (en) 2000-03-03 2004-12-14 Sipix Imaging, Inc. Electrophoretic display and novel process for its manufacture
US8520292B2 (en) 2000-03-03 2013-08-27 Sipix Imaging, Inc. Electrophoretic display and process for its manufacture
US6885495B2 (en) 2000-03-03 2005-04-26 Sipix Imaging Inc. Electrophoretic display with in-plane switching
US9081250B2 (en) 2000-03-03 2015-07-14 E Ink California, Llc Electrophoretic display and process for its manufacture
US20020126249A1 (en) * 2001-01-11 2002-09-12 Rong-Chang Liang Transmissive or reflective liquid crystal display and novel process for its manufacture
US6795138B2 (en) 2001-01-11 2004-09-21 Sipix Imaging, Inc. Transmissive or reflective liquid crystal display and novel process for its manufacture
US20040169813A1 (en) * 2001-01-11 2004-09-02 Rong-Chang Liang Transmissive or reflective liquid crystal display and process for its manufacture
US6784953B2 (en) 2001-01-11 2004-08-31 Sipix Imaging, Inc. Transmissive or reflective liquid crystal display and novel process for its manufacture
US8282762B2 (en) 2001-01-11 2012-10-09 Sipix Imaging, Inc. Transmissive or reflective liquid crystal display and process for its manufacture
US20030169387A1 (en) * 2001-01-11 2003-09-11 Rong-Chang Liang Transmissive or reflective liquid crystal display and novel process for its manufacture
US7095477B2 (en) 2001-01-11 2006-08-22 Sipix Imaging, Inc. Transmissive or reflective liquid crystal display and process for its manufacture
US6906779B2 (en) 2001-02-15 2005-06-14 Sipix Imaging, Inc. Process for roll-to-roll manufacture of a display by synchronized photolithographic exposure on a substrate web
US20030152849A1 (en) * 2001-02-15 2003-08-14 Mary Chan-Park Process for roll-to-roll manufacture of a display by synchronized photolithographic exposure on a substrate web
US6850355B2 (en) 2001-07-27 2005-02-01 Sipix Imaging, Inc. Electrophoretic display with color filters
US7679813B2 (en) 2001-08-17 2010-03-16 Sipix Imaging, Inc. Electrophoretic display with dual-mode switching
US7492505B2 (en) 2001-08-17 2009-02-17 Sipix Imaging, Inc. Electrophoretic display with dual mode switching
US7821702B2 (en) 2001-08-17 2010-10-26 Sipix Imaging, Inc. Electrophoretic display with dual mode switching
US7046228B2 (en) 2001-08-17 2006-05-16 Sipix Imaging, Inc. Electrophoretic display with dual mode switching
US20030034950A1 (en) * 2001-08-17 2003-02-20 Rong-Chang Liang Electrophoretic display with dual mode switching
US20070263277A1 (en) * 2001-08-17 2007-11-15 Rong-Chang Liang Electrophoretic display with dual mode switching
US20030035199A1 (en) * 2001-08-20 2003-02-20 Rong-Chang Liang Transflective electrophoretic display
US6751007B2 (en) 2001-08-20 2004-06-15 Sipix Imaging, Inc. Transflective electrophoretic display
US6795229B2 (en) 2001-08-28 2004-09-21 Sipix Imaging, Inc. Electrophoretic display with sub relief structure for high contrast ratio and improved shear and/or compression resistance
US20030043450A1 (en) * 2001-08-28 2003-03-06 Rong-Chang Liang Electrophoretic display with sub relief structure for high contrast ratio and improved shear and/or compression resistance
US7511876B2 (en) * 2002-05-30 2009-03-31 Canon Kabushiki Kaisha Dispersion for electrophoretic display, and electrophoretic display device
US20040027643A1 (en) * 2002-05-30 2004-02-12 Canon Kabushiki Kaisha Dispersion for electrophoretic display, and electrophoretic display device
US7038656B2 (en) 2002-08-16 2006-05-02 Sipix Imaging, Inc. Electrophoretic display with dual-mode switching
US7271947B2 (en) 2002-08-16 2007-09-18 Sipix Imaging, Inc. Electrophoretic display with dual-mode switching
US20040032391A1 (en) * 2002-08-16 2004-02-19 Rong-Chang Liang Electrophoretic display with dual-mode switching
US20040032389A1 (en) * 2002-08-16 2004-02-19 Rong-Chang Liang Electrophoretic display with dual mode switching
US7038670B2 (en) 2002-08-16 2006-05-02 Sipix Imaging, Inc. Electrophoretic display with dual mode switching
US7560004B2 (en) 2002-09-04 2009-07-14 Sipix Imaging, Inc. Adhesive and sealing layers for electrophoretic displays
US20040112525A1 (en) * 2002-09-04 2004-06-17 Cheri Pereira Adhesive and sealing layers for electrophoretic displays
US7166182B2 (en) 2002-09-04 2007-01-23 Sipix Imaging, Inc. Adhesive and sealing layers for electrophoretic displays
US20040216837A1 (en) * 2002-09-04 2004-11-04 Cheri Pereira Adhesive and sealing layers for electrophoretic displays
US20060139724A1 (en) * 2002-09-10 2006-06-29 Rong-Chang Liang Electrochromic or electrodeposition display and novel process for their manufacture
US7245414B2 (en) 2002-09-10 2007-07-17 Sipix Imaging, Inc. Electrochromic or electrodeposition display and novel process for their manufacture
US20040120024A1 (en) * 2002-09-23 2004-06-24 Chen Huiyong Paul Electrophoretic displays with improved high temperature performance
US20070035497A1 (en) * 2002-09-23 2007-02-15 Chen Huiyong P Electrophoretic displays with improved high temperature performance
US7616374B2 (en) 2002-09-23 2009-11-10 Sipix Imaging, Inc. Electrophoretic displays with improved high temperature performance
US7072095B2 (en) * 2002-10-31 2006-07-04 Sipix Imaging, Inc. Electrophoretic display and novel process for its manufacture
US20040169912A1 (en) * 2002-10-31 2004-09-02 Rong-Chang Liang Electrophoretic display and novel process for its manufacture
US7141279B2 (en) 2002-11-25 2006-11-28 Sipix Imaging, Inc. Transmissive or reflective liquid crystal display and novel process for its manufacture
US8023071B2 (en) 2002-11-25 2011-09-20 Sipix Imaging, Inc. Transmissive or reflective liquid crystal display
US9346987B2 (en) 2003-01-24 2016-05-24 E Ink California, Llc Adhesive and sealing layers for electrophoretic displays
US20100033803A1 (en) * 2003-01-24 2010-02-11 Xiaojia Wang Adhesive and sealing layers for electrophoretic displays
US20070036919A1 (en) * 2003-01-24 2007-02-15 Xiaojia Wang Adhesive and sealing layers for electrophoretic displays
US7572491B2 (en) 2003-01-24 2009-08-11 Sipix Imaging, Inc. Adhesive and sealing layers for electrophoretic displays
US7717764B2 (en) 2003-09-12 2010-05-18 Bridgestone Corporation Method of manufacturing image display panel and image display panel
US20070029931A1 (en) * 2003-09-12 2007-02-08 Bridgestone Corporation Method of manufacturing image display panel and image display panel
EP1666965A4 (en) * 2003-09-12 2006-11-08 Bridgestone Corp Image display panel production method and image display panel
EP1666965A1 (en) * 2003-09-12 2006-06-07 Bridgestone Corporation Image display panel production method and image display panel
US20060033677A1 (en) * 2004-08-10 2006-02-16 Kenneth Faase Display device
US7042614B1 (en) 2004-11-17 2006-05-09 Hewlett-Packard Development Company, L.P. Spatial light modulator
US20060103909A1 (en) * 2004-11-17 2006-05-18 Hewlett-Packard Development Company, L.P. Spatial light modulator
US20090051646A1 (en) * 2004-12-20 2009-02-26 Palo Alto Research Center Incorporated Flexible Electrophoretic-Type Display
US7463409B2 (en) 2004-12-20 2008-12-09 Palo Alto Research Center Incorporated Flexible electrophoretic-type display
US20060132579A1 (en) * 2004-12-20 2006-06-22 Palo Alto Research Center Incorporated Flexible electrophoretic-type display
US20080316564A1 (en) * 2005-12-22 2008-12-25 Eastman Kodak Company Display Devices
WO2008023309A1 (en) * 2006-08-21 2008-02-28 Koninklijke Philips Electronics N.V. A sealed cell structure
US20100015557A1 (en) * 2006-08-21 2010-01-21 Koninklijke Philips Electronics N.V. Sealed cell structure
US8153354B2 (en) 2006-08-21 2012-04-10 Koninklijke Philips Electronics N.V. Sealed cell structure
US20080220204A1 (en) * 2007-03-08 2008-09-11 Masaru Ohgaki Display panel, method of manufacturing a display panel, and display unit
US8241731B2 (en) * 2007-03-08 2012-08-14 Ricoh Company, Ltd. Display panel, method of manufacturing a display panel, and display unit
WO2009004265A3 (en) * 2007-07-04 2009-02-12 Essilor Int Transparent film comprising a base film and a coating
FR2918463A1 (en) * 2007-07-04 2009-01-09 Essilor Int TRANSPARENT FILM COMPRISING A BASIC FILM AND A COATING
WO2009004265A2 (en) * 2007-07-04 2009-01-08 Essilor International (Compagnie Generale D'optique) Transparent film comprising a base film and a coating
US20100177272A1 (en) * 2007-07-31 2010-07-15 Hewlet-Packard Development Company LP Pixel well electrodes
US7656493B2 (en) 2007-07-31 2010-02-02 Arthur Alan R Pixel well electrodes
US8199305B2 (en) 2007-07-31 2012-06-12 Hewlett-Packard Development Company, L.P. Pixel well electrodes
US9627646B2 (en) 2008-09-18 2017-04-18 Tesa Se Method for encapsulating an electronic arrangement
EP2166593A1 (en) 2008-09-18 2010-03-24 tesa SE Method for encapsulation of an electronic assembly
US20100068514A1 (en) * 2008-09-18 2010-03-18 Tesa Se Method for encapsulating an electronic arrangement
DE102008047964A1 (en) 2008-09-18 2010-03-25 Tesa Se Method for encapsulating an electronic device
US8460969B2 (en) 2008-12-03 2013-06-11 Tesa Se Method for encapsulating an electronic arrangement
US20110121356A1 (en) * 2008-12-03 2011-05-26 Tesa Se Method for encapsulating an electronic arrangement
DE102008060113A1 (en) 2008-12-03 2010-07-29 Tesa Se Method for encapsulating an electronic device
US8652565B2 (en) 2009-07-29 2014-02-18 Seiko Epson Corporation Sealing method of sealing dispersion liquid containing and electrophoretic particles, and electrophoretic display
US20110222141A1 (en) * 2010-03-10 2011-09-15 Seiko Epson Corporation Method for enclosing dispersion liquid containing electrophoretic particles and electrophoretic display unit
US8289615B2 (en) 2010-03-10 2012-10-16 Seiko Epson Corporation Method for enclosing dispersion liquid containing electrophoretic particles and electrophoretic display unit
US8587857B2 (en) 2010-10-27 2013-11-19 Industrial Technology Research Institute Electro-wetting display device and non-polar color solution thereof
EP2465426A1 (en) * 2010-12-20 2012-06-20 General Electric Company Biomedical sensor
US8718740B2 (en) 2010-12-20 2014-05-06 General Electric Company Biomedical sensor
DE102012203623A1 (en) 2012-03-07 2013-09-12 Tesa Se Composite system for the encapsulation of electronic devices
WO2013131707A1 (en) 2012-03-07 2013-09-12 Tesa Se Composite system for encapsulating electronic arrangements
US20170108740A1 (en) * 2014-04-04 2017-04-20 Lg Chem, Ltd. Liquid crystal element
US10196550B2 (en) * 2014-04-04 2019-02-05 Lg Chem, Ltd. Liquid crystal element
US9989798B2 (en) 2014-06-27 2018-06-05 Lg Display Co., Ltd. Light controlling apparatus, method of fabricating the light controlling apparatus and transparent display device including the light controlling apparatus with transparent mode and light shielding mode
US10203539B2 (en) * 2015-02-16 2019-02-12 Lg Chem, Ltd. Liquid crystal device
CN107111176A (en) * 2015-02-16 2017-08-29 株式会社Lg化学 Liquid-crystal apparatus
US20180011352A1 (en) * 2015-02-16 2018-01-11 Lg Chem, Ltd. Liquid crystal device
US10087344B2 (en) 2015-10-30 2018-10-02 E Ink Corporation Methods for sealing microcell containers with phenethylamine mixtures
US10793750B2 (en) 2015-10-30 2020-10-06 E Ink Corporation Methods for sealing microcell containers with phenethylamine mixtures
US20170166430A1 (en) * 2015-12-09 2017-06-15 Nova Chemicals (International) S.A. Hot Fill Process With Closures Made From High Density Unimodal Polyethylene
US10071895B2 (en) * 2015-12-09 2018-09-11 Nova Chemicals (International) S.A. Hot fill process with closures made from high density unimodal polyethylene
US10071826B2 (en) * 2015-12-10 2018-09-11 Nova Chemicals (International) S.A. Hot fill process with closures made from high density polyethylene compositions
US20170166332A1 (en) * 2015-12-10 2017-06-15 Nova Chemicals (International) S.A. Hot Fill Process With Closures Made From High Density Polyethylene Compositions
US20180210312A1 (en) * 2017-01-20 2018-07-26 E Ink California, Llc Color organic pigments and electrophoretic display media containing the same
US11099452B2 (en) * 2017-01-20 2021-08-24 E Ink California, Llc Color organic pigments and electrophoretic display media containing the same
US11493820B2 (en) * 2017-01-20 2022-11-08 E Ink California, Llc Color organic pigments and electrophoretic display media containing the same
US10782586B2 (en) * 2017-01-20 2020-09-22 E Ink California, Llc Color organic pigments and electrophoretic display media containing the same
US10585325B2 (en) 2017-03-09 2020-03-10 E Ink California, Llc Photo-thermally induced polymerization inhibitors for electrophoretic media
US10698265B1 (en) 2017-10-06 2020-06-30 E Ink California, Llc Quantum dot film
US11493805B2 (en) 2017-10-06 2022-11-08 E Ink California, Llc Quantum dot film with sealed microcells
WO2020033787A1 (en) 2018-08-10 2020-02-13 E Ink California, Llc Driving waveforms for switchable light-collimating layer including bistable electrophoretic fluid
WO2020033175A1 (en) 2018-08-10 2020-02-13 E Ink California, Llc Switchable light-collimating layer including bistable electrophoretic fluid
US11314098B2 (en) 2018-08-10 2022-04-26 E Ink California, Llc Switchable light-collimating layer with reflector
US11397366B2 (en) 2018-08-10 2022-07-26 E Ink California, Llc Switchable light-collimating layer including bistable electrophoretic fluid
US11435606B2 (en) 2018-08-10 2022-09-06 E Ink California, Llc Driving waveforms for switchable light-collimating layer including bistable electrophoretic fluid
US11656526B2 (en) 2018-08-10 2023-05-23 E Ink California, Llc Switchable light-collimating layer including bistable electrophoretic fluid
US11719953B2 (en) 2018-08-10 2023-08-08 E Ink California, Llc Switchable light-collimating layer with reflector
US11048124B2 (en) 2019-09-06 2021-06-29 Au Optronics Corporation Liquid crystal panel and manufacturing method thereof

Also Published As

Publication number Publication date
WO2002098977A1 (en) 2002-12-12
US20030035885A1 (en) 2003-02-20
JP4322663B2 (en) 2009-09-02
CN1389534A (en) 2003-01-08
US7144942B2 (en) 2006-12-05
MXPA03011144A (en) 2004-02-26
JP2005509690A (en) 2005-04-14
KR20040006017A (en) 2004-01-16
US7005468B2 (en) 2006-02-28
US20030004254A1 (en) 2003-01-02
KR100859305B1 (en) 2008-09-19
EP1401953A1 (en) 2004-03-31
CN1237140C (en) 2006-01-18
TWI301211B (en) 2008-09-21
CA2448440A1 (en) 2002-12-12

Similar Documents

Publication Publication Date Title
US7005468B2 (en) Composition and process for the sealing of microcups in roll-to-roll display manufacturing
US8361356B2 (en) Composition and process for the sealing of microcups in roll-to-roll display manufacturing
US6885495B2 (en) Electrophoretic display with in-plane switching
US6751007B2 (en) Transflective electrophoretic display
US6788449B2 (en) Electrophoretic display and novel process for its manufacture
US6795229B2 (en) Electrophoretic display with sub relief structure for high contrast ratio and improved shear and/or compression resistance
US7233429B2 (en) Electrophoretic display
US6850355B2 (en) Electrophoretic display with color filters
US6947202B2 (en) Electrophoretic display with sub relief structure for high contrast ratio and improved shear and/or compression resistance
US6865012B2 (en) Electrophoretic display and novel process for its manufacture
JP2005509690A5 (en)
EP1352288A2 (en) Manufacturing process for electrophoretic display
WO2003009059A1 (en) In-plane switching electrophoretic display
JP2004536344A5 (en)

Legal Events

Date Code Title Description
AS Assignment

Owner name: SIPIX IMAGING, INC., CALIFORNIA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:ZANG, HONGMEI;WANG, XIANJIA;LIANG, RONG-CHANG;REEL/FRAME:012223/0461

Effective date: 20010919

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION