Patent ID: 6714179
Filing Date: 2004-03-30
Classification: G09G,H03M

Abstract:
A system for actuating a liquid crystal display, comprising:(a) a matrix of liquid crystal pixels; (b) a digital-to-analog converter adapted to apply at an output a pixel charging voltage corresponding to a calibrated multi-bit digital signal received at an input and coupled to the matrix to apply the pixel charging voltage to at least one pixel; (c) a reference voltage generator adapted to apply one of at least a first and second reference voltages at an output; (d) a comparator with first and second inputs and an output, the first input coupled to the output of the reference voltage generator and the second input coupled to the output of the digital-to-analog converter, the comparator adapted to provide one of two signals at the output depending upon which input receives a higher voltage; (e) a digital calibrator coupled at a first output to the input of the digital-to-analog converter and adapted to: receive at a first input an uncalibrated multi-bit digital signal, modify the uncalibrated multi-bit digital signal based at least in part on the output of the comparator to produce the calibrated multi-bit digital signal, and apply the calibrated multi-bit digital signal to the first output; (f) a second digital-to-analog converter adapted to apply at an output a pixel charging voltage corresponding to a calibrated multi-bit digital signal received at an input from the digital converter and coupled to the matrix to apply the pixel charging voltage to at least one pixel; and (g) a multiplexer circuit, wherein the digital-to-analog converters are coupled to the second input of the comparator through the multiplexer circuit and the reference voltage generator is coupled to the first input of the comparator through the multiplexer circuit.