Display drive device and drive controlling method

A display device which performs image display based on the display data composed of digital signals, said display device comprising:

• a display panel in which two-dimensional array of a plurality of display pixels is performed;
• and
• a data driver including:
• a scanning driver which sequentially scans a display pixel cluster of each line of the display panel and sets the scanned display pixel cluster in a selective state;
• a gradation voltage setting circuit which performs voltage division of a provided highest reference voltage and a provided lowest reference voltage, and produces a plurality of gradation voltages corresponding to each luminosity gradation of the display data;
• a gradation conversion circuit which produces a display signal voltage of a different voltage level for each luminosity gradation of the display data based on the plurality of gradation voltages produced by the gradation voltage setting circuit, wherein two different voltage levels of the display signal voltage are produced for the luminosity gradations in a predetermined period;
• and
• a display signal voltage output circuit which applies the display signal voltage to the display pixels;
• wherein in the data driver, a center voltage of the two voltage levels of the display signal voltage at a highest luminosity gradation of the luminosity gradations of the display data is set to a potential higher than the center voltage in a lowest luminosity gradation of the luminosity gradations by only an amount corresponding to a correction voltage that is set based on characteristics of the display pixels;
• wherein a difference of voltage level for the center voltage between a first highest gradation voltage and a second highest gradation voltage which correspond to the two voltage levels of the display signal voltages at the highest luminosity gradation, and a difference of voltage level for the center voltage between a first lowest gradation voltage and a second lowest gradation voltage which correspond to the two voltage levels of the display signal voltages at the lowest luminosity gradation are set to an equivalent value;
• wherein a first voltage range comprised of the difference between the first highest gradation voltage and the first lowest gradation voltage, and a second voltage range comprised of the difference between the second highest gradation voltage and the second lowest gradation voltage are charged by only an amount corresponding to a change of the highest reference voltage or the lowest reference voltage, when at least one of the highest reference voltage or the lowest reference voltage is changed;
• and
• wherein a change characteristic value of the center voltage is maintained constant for each luminosity gradation of the display data.

A drive controlling method for a display drive device which drives a display panel comprising a plurality of display pixels based on display data composed of digital signals, the method comprising:

• performing voltage division of a provided highest reference voltage and a provided lowest reference voltage, and producing a plurality of a gradation voltages corresponding to each luminosity gradation of the display data;
• producing a display signal voltage of a different voltage level for each luminosity gradation of the display data based on the produced plurality of gradation voltages, wherein two different voltage levels of the display signal voltage are produced for the luminosity gradations in a predetermined period;
• setting a center voltage of the two voltage levels of the display signal voltage at a highest luminosity gradation of the luminosity gradations by only an amount corresponding to a correction voltage that is set based on characteristics of the display pixels;
• setting a difference of voltage level for the center voltage between a first highest gradation voltage and a second highest gradation voltage which correspond to the two voltage levels of the display signal voltages at the highest luminosity gradation, and a difference of voltage level for the center voltage between a first lowest gradation voltage and a second lowest gradation voltage which correspond to the two voltage levels of the display signal voltages at the lowest luminosity gradation to an equivalent value;
• changing a first voltage range comprised of the difference between the first highest gradation voltage and the first lowest gradation voltage, and a second voltage range comprised of the difference between the second highest gradation voltage and the second lowest gradation voltage by only an amount corresponding to a change of the highest reference voltage or the lowest reference voltage, when at least one of the highest reference voltage or the lowest reference voltage is changed;
• maintaining a change characteristic value of the center voltage constant for each luminosity gradation of the display data.