A portable computer has a keyboard and a display unit mounted to a base unit. The base unit is equipped with a battery for generating a reference voltage. The display unit has a plasma display and a housing for containing the plasma display. This housing is rotated to an open position for permitting...http://www.google.se/patents/US5583529?utm_source=gb-gplus-sharePatent US5583529 - Portable apparatus having a flat panel type display unit
