Patent ID: 6650383
Filing Date: 2003-11-18
Classification: G02F

Abstract:
A reflective liquid crystal lightvalve for modulating the polarization of incident light within a specified band of wavelengths into on and off states, the lightvalve comprising:a pixelated reflective backplane; a first liquid crystal layer, positioned proximate the pixelated reflective backplane, the first liquid crystal layer being tuned in the off state to switch incident light at the center of the specified band of wavelengths into a state that is not fully off; and a second liquid crystal layer, positioned proximate the first liquid crystal layer wherein the first liquid crystal layer is positioned between the second liquid crystal layer and the pixelated reflective backplane, the second liquid crystal layer having a birefringence which, at a given depth within its thickness, is substantially equal and opposite to a birefringence of a layer within the first liquid crystal layer that is located at a matching distance from a midplane separating the first and second liquid crystal layers.