GRADATION CORRECTION DEVICE

摘要

PURPOSE:To realize the gradation correction device implementing a quick response in following a change in a video image scene stably and smoothly by solving a problem of mis-detection of a control signal due to effect of noise or the like resulting in vibrating a correction output in the gradation correction device used for a television receiver. CONSTITUTION:An output of a lookup table memory 11 is fed to a constant multiple circuit 31 and an output signal of the circuit 31 and an output signal of a lookup table arithmetic circuit 10 are added by an adder 32 and the result of the addition is set to the lookup table memory 11. Moreover, a video scene change detection circuit 33 is provided between an output terminal of the lookup table arithmetic circuit 10 and a coefficient control terminal of the constant multiple circuit 31 to change a coefficient of the constant multiple circuit 31 in response to a change in a video image scene thereby implementing the gradation correction in following a change in a video image scene stably and smoothly with immunity to noise.