Title:
【発明の名称】映像信号処理装置
Document Type and Number:
Japanese Patent JP3375557
Kind Code:
B2
Abstract:
An automatic gain controlling circuit controls a gain of a video signal from an imager having an electronic shutter function according to a gain control signal. An average detecting circuit detects an average level of a luminance signal of the video signal. An automatic exposure controlling circuit generates the gain control signal according to the luminance average level in response to a mode signal indicative of the cycle of the ac line and generates a timing signal corresponding to the ac line and a shutter speed control signal together with electronic shutter control signal generation circuit at a unit of the voltage variation cycle of the ac line according to the luminance average level such that a shutter interval of the imager is changed stepwise and each of the shutter intervals is an integer times the voltage variation cycle of the ac line. The automatic exposure controlling range is expanded by changing the shutter speed stepwise from 1/100 sec, 2/100 sec 3/100 sec at 50-Hz-ac area, for example, to provide coarse exposure controlling and fine automatic gain controlling is provided every shutter interval to suppress flicker.
Inventors:
Kazuo Oda
Masaki Kariya
Masaki Kariya
Application Number:
JP2214199A
Publication Date:
February 10, 2003
Filing Date:
January 29, 1999
Export Citation:
Assignee:
Matsushita Electric Industrial Co., Ltd
International Classes:
H04N5/21; H04N5/235; H04N5/238; H04N5/243; H04N5/335; H04N5/351; H04N5/353; H04N5/355; H04N5/357; H04N5/369; H04N5/372; H04N5/374; H04N5/378; (IPC1-7): H04N5/235; H04N5/21; H04N5/335
Domestic Patent References:
| JP200032330A | ||||
| JP11155107A | ||||
| JP1227582A |
Attorney, Agent or Firm:
Role Masaaki (3 others)