| 摘要 |
PROBLEM TO BE SOLVED: To provide a liquid crystal display device capable of adjusting luminance even when there are a bright area and a dark area in a screen so that the areas can easily be seen, and to provide a luminance adjusting method. SOLUTION: Broadcast waves received by an antenna 101 are demodulated by a demodulator circuit 102, and a video signal is inputted to a dividing network 103 and a liquid crystal display circuit 107. The dividing network 103 divides the video period of the video signal into m periods in the horizontal direction and into n periods in the vertical direction according to the arrangement of a light source 106 of backlight, then the divided video signals are inputted to an APL (average luminances) detecting circuit 104, which detects each average luminance (APL) of the video signals and outputs them to a signal processing circuit 109, and an arithmetic calculation is performed for adjusting a gain according to the height of the APL by using the APL detection results of each area and respective correlations of respective areas. An inverter control circuit 105 controls the duty factor of an inverter of each light source 106 to adjust the brightness of the light source 106.
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