Patent ID: 6166787
Filing Date: 2000-12-26
Classification: G02B,G02F

Abstract:
An optical display device comprising:an optical cell having a cell front with at least one cell region being capable of an optically transmissive mode and an optically nontransmissive mode with reference to the cell front;an optically active material contained in the optical cell, the optically active material responsive to an applied electrical field such that optical properties of the material are controllably changeable;reflective means for reflecting light incident upon the reflective means toward the cell front, said reflective means associated with the optical cella prismatic film including a prismatic surface facing the cell front and an opposite surface opposite the prismatic surface, the prismatic surface comprising a series of prisms, each of said prisms having a first face and a second face intersecting the first face; the first face oriented to refract light obliquely intercepting the first face, the second face oriented to minimize refractive, reflective and optical interactions of the light with the second face; the prismatic film, the cell, and the reflective means optically cooperating such that light entering a display at an incident angle is emitted from the display at an exiting angle distinct from the incident angle for viewing of the display, the incident angle and the exiting angle measured relative to a normal axis orthogonally extending from a viewing plane substantially parallel to the cell front.