Patent ID: 7106321
Filing Date: 2006-09-12
Classification: G09G

Abstract:
1. A reference voltage generation circuit which generates multi-valued reference voltages for generating a gray scale value corrected by gamma correction based on gray scale data, the reference voltage generation circuit comprising: a positive polarity ladder resistor circuit including: a first ladder resistor circuit formed of a plurality of first resistor circuits connected in series, a first switching circuit inserted between a first power source line supplied with a first power source voltage and one end of the first ladder resistor circuit, a second switching circuit inserted between a second power source line supplied with a second power source voltage and the other end of the first ladder resistor circuit, and first to i-th reference voltage output switching circuits respectively inserted between first to i-th division nodes (“i” is an integer larger than or equal to 2) and first to i-th reference voltage output nodes, the first to i-th division nodes being formed by dividing the first ladder resistor circuit by the first resistor circuits; and a negative polarity ladder resistor circuit including: a second ladder resistor circuit formed of a plurality of second resistor circuits connected in series, a third switching circuit inserted between the first power source line and one end of the second ladder resistor circuit, a fourth switching circuit inserted between the second power source line and the other end of the second ladder resistor circuit, and (i+1)th to wherein the first and second switching circuits and the first, to i-th reference voltage output switching circuits are controlled based on a first switching control signal, and wherein the third and fourth switching circuits and the (i+1)th to