Pioneer Electronic Corporation

Pioneer Corporation

Pioneer Display Products Corporation

Junichi Usui

Masayuki Takeda

Nozomu Kikuchi

Hirofumi Kawaguchi

Shuji Ogawa

An apparatus discriminates a color format. The signal processing paths separate a luminance signal and a color signal from a broadcasting signal based on a plurality of color formats. The direct signal path provides a direct output of the broadcasting signal without separating the luminance signal and the color signal therefrom. The relay device selectively relays the broadcasting signal as input to any one of the respective signal processing paths and the direct signal path. The detection device detects color format variation of the broadcasting signal based on an output signal from the signal processing paths. The discrimination device discriminates the color format of the broadcasting signal based on the broadcasting signal as input through the direct signal path. The control device controls the relay device to relay the broadcasting signal to the direct signal path when color format variation is detected by the detection device.

Apparatus and method for discriminating color format

A video signal processing circuit in which nearly 100% of a largest possible dynamic range can be used, desired contrast is obtained, and desired brightness characteristics are obtained by an increasing in luminance of a screen. The circuit has an RGB amplifier which amplifies three primary color video signals R, G, and B by a predetermined gain and in which the gain is controlled by a gain control signal, A/D converters for converting analog three primary color video signals which are generated from the RGB amplifier into digital signals respectively, inverse gamma correcting circuits for effecting an inverse gamma correction to the three primary color digital video signals respectively, an OR circuit and a peak holding circuit for detecting peak levels of the analog three primary color signals, and a gain control signal generator for generating a gain control signal in accordance with the peak levels. When the peak levels are equal to or larger than a predetermined value, the gain control signal generator supplies the gain control signal to control the RGB amplifier so as to set the level of each of the three primary color digital video signals generated by the A/D converters at a peak value.

Video signal processing circuit providing optimum signal level for inverse gamma correction

Growing community of inventors

Fukuroi, Japan

Junichi Usui