| 摘要 |
PROBLEM TO BE SOLVED: To provide a liquid crystal display device that obtains maximum contrast by driving a liquid crystal element with AC voltage at a high frequency two or more times a frame rate, and corrects mismatching between a central potential of a common electrode voltage caused by DC offset of the liquid crystal element and an inverted central potential of positive-polarity and negative-polarity lamp signals, and a common electrode voltage setting method thereof. SOLUTION: The method includes: selecting video data of gray level where a potential of a positive-polarity lamp signal is equal to a potential of a negative-polarity lamp signal (S1 to S5); detecting a DC potential (Vcedc) of a common electrode where light from a plurality of pixels acquired while the video data is input has lowest luminance (S6 to S9); and measuring the luminance of the light from the plurality of pixels while two voltages Vce(+) and Vce(-) corresponding to a potential associated with the detected potential are alternately switched to be applied to the common electrode of the liquid crystal element, and setting, as common electrode voltages, a first voltage and a second voltage where a ratio of the luminance measured at the time of inputting video data of the maximum gray level to the luminance measured at the time of inputting video data of the minimum gray level is maximum (S10 to S15). COPYRIGHT: (C)2011,JPO&INPIT
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