Patent ID: 7248254

Claim:
A gamma correcting circuit comprising: a basic voltage generating circuit which has one end connected to a first high-potential power supply and the other end connected to a first low-potential power supply and generates and outputs a plurality of basic voltages by dividing a voltage difference between a voltage of said first high-potential power supply and a voltage of said first low-potential power supply; a gamma correction resistor circuit having a plurality of resistor elements connected in series between a second high-potential power supply and a second low-potential power supply, and gray-scale voltage output terminals and n (n being a positive integer >1) reference-voltage output terminal groups, both provided at respective nodes between said resistor elements, each of said n reference-voltage output terminal groups including a maximum of u (u being a positive integer >1) reference-voltage output terminal candidates; and a gamma correction adjusting circuit having n gamma characteristic adjusting units in association respectively with said n reference-voltage output terminal groups, each of said n gamma characteristic adjusting units selects one of a maximum v (v being a positive integer >1) basic voltages supplied from said basic voltage generating circuit as a reference voltage based on correction adjustment data and selects an output terminal for said selected reference voltage from said maximum of u reference-voltage output terminal candidates included in the associated one of said n reference-voltage output terminal groups based on said correction adjustment data, said gamma characteristic adjusting units each comprising: a data latch which fetches and latches said correction adjustment data at a predetermined timing; a reference voltage selector which receives a plurality of basic voltages and selects and outputs one of said basic voltages as a reference voltage based on said correction adjustment data latched by said data latch; a node selector which has a first terminal, a second terminal, a switch circuit and a plurality of voltage output terminals that comprise the associated reference-voltage output terminal group and selects, from said voltage output terminals of said associated reference-voltage output terminal group, the reference-voltage output terminal which is connected to said first terminal and said second terminal by said switch circuit, based on said correction adjustment data latched by said data latch; and an operational amplifier having a positive input terminal to which an output of said reference voltage selector is input, a negative output terminal connected to said first terminal and an output terminal connected to said second terminal.