[ii] Patent Number: 4,900,138  Date of Patent: Feb. 13,1990
Primary Examiner—Bruce Y. Arnold
Assistant Examiner—Rebecca D. Gass
Attorney, Agent, or Firm—Cumpston & Shaw
A composite gradient index and curved surface anamorphic lens has a gradient index of refraction and at least one curved surface. Combinations of planar and radial gradients with spherical and cylindrical surfaces are described. A corrector for an light source whose beam divergences are different in orthogonal planes using such a lens and a light beam scanning mechanism are disclosed. In the light beam scanning system, a homogeneous toroidal lens is replaced by a toroidal equivalent gradient-index lens, hereafter referred to as a TEGIL. The lens reduces undesirable displacement of the focus light beam from a scan line on a receptor plane and from the receptor plane itself. The TEGIL comprises a body of gradient-index material having cylindrical faces for generating optical power in a first dimension and whose gradient-index generates optical power in an orthogonal dimension.
36 Claims, 14 Drawing Sheets