Patent · US Expired

Phase difference detector with analog signals

US4849619A · kind A · utility

5Cited by
6References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 11, 1987
Grant dateJul 18, 1989
Priority date
Expiry dateSep 11, 2007

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02B7/346
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A phase difference detector of the type capable of distinguishing a focused state by detecting relative positions of a pair of optical images obtained from an object, comprises sensor means adapted to photoelectrically convert the pair of optical images and to output a first analog electrical signal corresponding to one of the optical images and a second analog electrical signal corresponding to the other optical image, the signals being generated by the photoelectric conversion, at a predetermined period and in a non-destructive manner, and analog arithmetic means for subjecting the pair of analog electrical signals output from the sensor means to a correlative arithmetic operation.

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