Patent · US Expired

Focal length varying device for camera

US4870439A · kind A · utility

16Cited by
1References
24Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 13, 1989
Grant dateSep 26, 1989
Priority date
Expiry dateJan 13, 2009

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02B7/10
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A focal length varying device for a camera comprises a photo taking optical system having a variable focal length; a discriminating device for discriminating whether or not adequate photographing is possible; and a system for automatically changing the focal length of the photo taking optical system on the basis of the result of discrimination made by the discriminating device.

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