Title:
【発明の名称】カメラの絞り制御装置
Document Type and Number:
Japanese Patent JP3083176
Kind Code:
B2
Abstract:
PURPOSE:To enable accurate stop value detection even when the characteristic of Hall elements detecting the stop value is fluctuated. CONSTITUTION:The shutter speed and the gain of a signal processing circuit 4 are set so that the output signal of the signal processing circuit 4 becomes the set proper level by opening a diaphragm 2 while packing up the image of an object with a constant illuminance. Then, the shutter speed and the gain of the signal processing circuit 4 are properly changed, and the exposure control is performed so that the, output of the signal processing circuit 4 becomes the proper level by controlling the diaphragm 2 to obtain the proper level of the output signal of the signal processing circuit 4. The stop value voltage data from an A/D converter 15 is stored in an EEPROM10 as reference stop value voltage data in the prescribed stop value. In normal use, the stop value voltage data to be outputted from the A/D converter 15 and this reference stop value voltage data are compared to detect the stop value of the diaphragm 2.
Inventors:
Hiroyuki Tarumi
Tomoyuki Kurashige
Takuya Imade
Tomoyuki Kurashige
Takuya Imade
Application Number:
JP17181091A
Publication Date:
September 04, 2000
Filing Date:
June 18, 1991
Export Citation:
Assignee:
株式会社日立製作所
株式会社日立画像情報システム
株式会社日立画像情報システム
International Classes:
G03B7/10; G03B7/085; H04N5/238; (IPC1-7): G03B7/10; G03B7/085
Domestic Patent References:
| JP59232319A | ||||
| JP6111729A | ||||
| JP3144426A | ||||
| JP3144546A | ||||
| JP56133953A | ||||
| JP2187737A |
Attorney, Agent or Firm:
Kenjiro Take