Patent ID: 7580024

Claim:
A receiving unit which receives a video signal; a signal-processing unit which performs a specific process on the video signal received at the receiving unit; a luminance-curve converter which converts the input/output characteristic of the luminance level of an input video signal in the signal-processing unit; a display device which displays an image represented by the video signal that is an output of the luminance-curve converter; a histogram-extracting unit which generates histogram distribution data for a luminance level of a video signal that is to be input to the luminance-curve converter; characteristic-control-data output unit which sets a characteristic to the luminance-curve converter so that the converter emphasizes a low-luminance region when the histogram distribution data shows that the image represented by the input video signal includes the low-luminance region; a first control-signal generating unit which generates a control signal that reduces the amount of light emitted from a backlight to a value corresponding to a value obtained by integrating data from a controlling part of the low-luminance region output from the luminance-curve converter; a second control-signal generating unit which determines darkness of the image from the histogram distribution data and generates a control signal that reduces the amount of light emitted from the backlight in accordance with the darkness of the image; and a selector which selects and outputs one of the control signals output from the first and second control-signal generating units, which reduces the amount of light emitted from the backlight.