IMAGE LUMINANCE DETECTION CIRCUIT, IMAGE LUMINANCE ADJUSTING DEVICE, AND IMAGE LUMINANCE DETECTION METHOD

摘要

PROBLEM TO BE SOLVED: To obtain an image luminance detection circuit, an image luminance adjusting device with high precision of luminance adjustment, which can be miniaturized and an image luminance detection method by performing separation processing of a luminance information signal GD by every piece of screen division information.;SOLUTION: The image luminance detection circuit is provided with a synchronization adjustment circuit 3 which inputs the luminance information signal GD and outputs a synchronous luminance signal CD formed by performing phase control of the luminance information signal GD, an image luminance detection circuit 1 which performs cumulative operations of luminance information signals BD1 to BD4 distributed according to a screen separation signal SD, respectively and generates a luminance adjustment signal HD based on results LD1 to LD4 of the cumulative operations, an image quality adjustment circuit 2 which generates a correction signal QD based on the luminance adjustment signal HD and an adder 4 which adds the synchronous luminance signal CD and the correction signal QD and generates video information ED.;COPYRIGHT: (C)2005,JPO&NCIPI