Patent · US Expired

Photosensor for optical observing or photographing devices

US4556787A · kind A · utility

3Cited by
3References
5Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 14, 1983
Grant dateDec 3, 1985
Priority date
Expiry dateMar 14, 2003

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02B7/32
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

The photosensor is provided with a light-receiving surface for receiving a reflected image of an object and in which an aperture is provided. The aperture is positioned so as to receive a focused image and means are provided to prevent light from leaking directly to the light-receiving surface from the aperture. Prevention of light leakage permits focusing to be detected at high precision.

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