Patent · US Expired

Focus detecting photoelectric device

US4039824A · kind A · utility

4Cited by
6References
6Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJul 8, 1975
Grant dateAug 2, 1977
Priority date
Expiry dateJul 8, 1995

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02B7/36
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A focus detecting photoelectric device herein disclosed is usable in a focus control system and is placed on an image plane where an optical image of a subject to be, for example, photographed through an objective lens assembly is focused to detect whether the image has been exactly focused or whether the image is out of focus. An output signal from the photoelectric device herein disclosed is used to control the focus control system to effect the desired focus control in relation to the objective lens assembly. To this end, the focus detecting photoelectric device is composed of at least one group of photoelectric elements, such as photodiodes, connected in series to each other with the cathode of one photoelectric element connected to the anode of the other photoelectric element. These photoelectric elements of the group may be formed on a semiconductor substrate in a predetermined pattern by the use of a known IC circuit making technique.

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