Patent ID: 6519012
Filing Date: 2003-02-11
Classification: G09G,H04N

Abstract:
A liquid crystal-based light valve system with contrast control, the light valve system comprising:a light input, through which light having a first direction of polarization is received; a ferroelectric liquid-crystal-based spatial light modulator including signal processing electronics and array of pixels, the array of pixels configured to receive light from the light input and including: an array of pixel electrodes, each pixel electrode defining the location of one pixel in the array of pixels and independently switchable by the signal processing electronics between a first voltage level corresponding to a first pixel condition, in which light exiting the pixel has a second direction of polarization, and a second voltage level corresponding to a second pixel condition, in which light exiting the pixel has a third direction of polarization that is within 5 degrees of orthogonal to the second direction of polarization, a transparent electrode Fat a third voltage level between the first voltage level and the second voltage level and a layer of ferroelectric liquid crystal material sandwiched between the transparent electrode and the array of pixel electrodes; an analyzer having orthogonal directions of maximum transmissivity and minimum transmnissivity, the analyzer positioned to receive the light exiting the array of pixels and aligned with: the direction of minimum transmissivity within 5 degrees of the second direction of polarization, and the direction of maximum transmissivity within 5 degrees of the third direction of polarization; and a voltage controller configured to adjust at least one of the first voltage level and the second voltage level through a first range of voltages and a second range of voltages, respectively.