Picture signal processing circuit

Abstract

Abstract PURPOSE:To improve durability and reliability of a picture signal processing circuit capable of adjusting the brightness by detecting operation of a setting for setting the brightness of the picture, generating a digitally changing brightness setting signal and adjusting the brightness of the picture based thereon. CONSTITUTION:On the surface panel of a light source unit 12, brightness setting switches 30a, 30b are disposed. A comparator 38 compares a reference signal supplied from a D/A converter 36 with the output signal of an image process circuit 26, drives a diaphragm 24 through a diaphragm drive circuit 44 in accordance with the difference, then changes the quantity of light of an illuminating light from a lamp 22 incoming to a light guide 16. Thereby, the brightness of an object to be photographed is adjusted, and as a result, the brightness of a picture signal outputted from a CCD 20 is adjusted. At the same time, the output of the comparator 38 is supplied to an AGC circuit 28, the gain of the output video signal of the image processing circuit is changed, and the brightness of a display picture of a color monitor 14 is changed. Thereby, the brightness of the picture is adjusted.

Inventors

• 👤 Tadashi Kato
• 👤 正 加藤
• 👤 Yutaka Takahashi
• 👤 豊 高橋
• 👤 Masahide Sugano
• 👤 菅野　正秀
• 👤 Masahiko Sasaki
• 👤 雅彦 佐々木

Bibliographic Details