Patent ID: 7411596

Claim:
A color image display driving circuit for generating a plurality of voltage signals to be applied to a plurality of pixel formation portions, based on input signals including a first, a second and a third color image signal that respectively represent gradations of a first, a second and a third color constituting three primary colors, the driving circuit comprising: a gradation voltage generation circuit for outputting a gradation voltage group made of a plurality of voltages that represent different gradations, said gradation voltage generation circuit comprising a voltage divider circuit for generating a plurality of voltages, a first variable resistor circuit connected to one side of the voltage divider circuit, and a second variable resistor circuit connected to the other side of the voltage divider circuit; a plurality of selection circuits, each selection circuit being for selecting one of the plurality of voltages in the gradation voltage group in accordance with the input signals; and an output circuit for outputting the plurality of voltages selected by the plurality of selection circuits respectively as the plurality of voltage signals; wherein the plurality of selection circuits successively switch between a first period in which the voltage is selected in accordance with the first color image signal, a second period in which the voltage is selected in accordance with the second color image signal, and a third period in which the voltage is selected in accordance with the third color image signal; wherein the first variable resistor circuit comprises a first selector for switching the resistance of the first variable resistor circuit such that the resistance of the first variable resistor circuit takes on a preset first value corresponding to the first color in the first period, a preset second value corresponding to the second color in the second period, and a preset third value corresponding to the third color in the third period; wherein the second variable resistor circuit comprises a second selector switch for switching the resistance of the second variable resistor circuit such that the resistance of the second variable resistor circuit takes on a preset fourth value corresponding to the first color in the first period, a preset fifth value corresponding to the second color in the second period, and a preset sixth value corresponding to the third color in the third period; and wherein the gradation voltage generation circuit outputs the plurality of voltages generated by the voltage divider circuit as the gradation voltage group and changes a portion of or all voltages constituting the gradation voltage group in response to the switching between the first period, the second period and the third period, and in accordance with the differences between the first color, the second color and the third color in gradation reproducibility of the plurality of pixel formation portions.