Patent · US Expired

Automatic focusing device for use in a camera

US4825237A · kind A · utility

22Cited by
2References
5Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 17, 1988
Grant dateApr 25, 1989
Priority date
Expiry dateMar 17, 2008

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02B7/282
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

An automatic focusing device for use in a camera using photographic lenses having a variable power region in which an entire focal length of a variable power optical system comprising a variable power lens group, a focusing lens group and a macro lens group disposed on an identical optical axis can optionally be set by the variable power lens group between a shortest focal length and a longest focal length, a macro region capable of macro photographing by the macro lens group, a variable power focusing region from an infinite position to a nearest position on the optical axis corresponding to an object distance from an infinite distance to a nearest distance and a macro focusing region capable of macro photographing in a predetermined region disposed from a nearest position on a side opposite to an infinite position.

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