Patent · US Expired

Shutter control circuit for cameras

US3952318A · kind A · utility

2Cited by

6References

13Claims

0Family size

Assignee

Asahi Kogaku Kogyo Kabushiki Kaisha · JP

Inventors

Chiharu Mori
Masahiro Kawasaki · Saitama, JP
Hirokazu Ando · Kariya, JP

Key dates

Filing date	Oct 9, 1974
Grant date	Apr 20, 1976
Priority date	—
Expiry date	Oct 9, 1994

Classification

Technology area (CPC G)Physics
CPC primaryG03B7/083
WIPO fieldOptics
WIPO sectorInstruments

Abstract

An electrical system to be used in a camera for controlling exposure time. The electrical system includes a pair of substantially identical constant voltage sources respectively having inputs connected together. A buffer circuit is coupled between an interconnection of these inputs and the collector of a compression transistor to which a photosensitive means is connected and whose base is coupled to one of the constant voltage sources. A timing circuit is coupled to an expansion transistor, whose base is coupled to the other of the constant voltage sources.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.