Patent ID: 7808474

Claim:
A light control circuit for a display control drive device on a semiconductor substrate, the light control circuit comprising: a plurality of input terminals adapted to be coupled to a plurality of optical sensors; a common sampling circuit that samples the outputs of the optical sensors inputted through the input terminals; a level determination circuit that determines levels of voltages sampled by the sampling circuit; an output terminal through which a result of said determination by the level determination circuit is outputted; and an input selecting circuit provided between the input terminals and the sampling circuit, wherein the sampling circuit samples the outputs of the optical sensors sequentially inputted through the input terminals in a temporally dispersed manner by the input selecting circuit, and wherein the level determination circuit includes a plurality of registers constructed to hold a plurality of discrimination results corresponding to the levels of the voltages in chronological order so that discrimination results for one said optical sensor are stored consecutively into each said register; a plurality of majority decision determination circuits coupled to the plurality of registers and configured to determine a majority of the discrimination results based on values held in the plurality of registers and to output a result of majority determination; and an encoder configured to encode the result of the majority determination and to output the result of encoding as a result of the determination to control a brightness of a backlight for a display panel.