Patent ID: 6724379
Filing Date: 2004-04-20
Classification: G09G

Abstract:
A multichannel driver circuit for controlling each of a plurality of channels of a spatial light modulator, said circuit comprising:(a) a control logic processor for providing a digital pixel value; (b) a reference voltage and correction generator that provides as output for all channels a positive half-cycle reference voltage and a negative half-cycle reference voltage, and that provides as output for each channel, based on digital calibration data: (b1) a gain compensation value; (b2) a positive half-cycle correction voltage; and, (b3) a negative half-cycle correction voltage; (c) a channel signal generator for each channel for accepting as input said digital pixel value and said gain compensation value and for providing as output a conditioned gain analog pixel voltage; (d) a flipper circuit for each channel for accepting as input said conditioned gain analog pixel voltage, said positive half-cycle reference voltage, said positive half-cycle correction voltage, said negative half-cycle reference voltage, and said negative half-cycle correction voltage and for providing as output: (d1) a positive half-cycle pixel driver output voltage obtained by conditioning said positive half-cycle reference voltage by said positive half-cycle correction voltage and summing the result with said conditioned gain analog pixel voltage; (d2) a negative half-cycle pixel driver output voltage obtained by conditioning said negative half-cycle reference voltage by said negative half-cycle correction voltage and summing the result with the additive inverse of said conditioned gain analog pixel voltage; (e) a comparator for performing the following operations for each channel: (e1) sampling said positive half-cycle pixel driver output voltage from said flipper circuit and providing a first output signal to said control logic processor indicative that said positive half-cycle pixel driver output voltage is substantially equal to said positive half-cycle reference voltage; (e2) sampling said negative half-cycle pixel driver output voltage from said flipper circuit and providing a second output signal to said control logic processor indicative that said negative half-cycle pixel driver output voltage is substantially equal to said negative half-cycle reference voltage.