Patent ID: 7656376

Claim:
A gamma voltage generation circuit providing groups of gamma voltages, the gamma voltage generation circuit comprising: a resistor string having a plurality of resistors connected in series and grouped into a plurality of segments, wherein each of the segments provides one of the gamma voltages; a plurality of switches respectively coupled to a plurality of nodes between the resistors in one of the segments; and wherein the switches are closed when one of the groups of the gamma voltages are output and the switches are opened when another one of the groups of the gamma voltages are output, and wherein first, second, third and fourth groups of the gamma voltages are output, each of the segments has first, second, third and fourth resistors connected in series, and the switches comprise: a plurality of first switches, each of which has one end coupled to the node where the first and second resistors are connected, and the other end coupled to the node outputting one of the gamma voltages; a plurality of second switches, each of which has one end coupled to the node where the second and third resistors are connected, and the other end coupled to the node outputting one of the gamma voltages; and a plurality of third switches, each of which has one end coupled to the node where the third and fourth resistors are connected, and the other end coupled to the node outputting one of the gamma voltages.