Patent · US Expired

Viewfinder for a camera with changeable focal length

US4887109A · kind A · utility

25Cited by
6References
10Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 27, 1988
Grant dateDec 12, 1989
Priority date
Expiry dateMay 27, 2008

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02B23/145
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A camera having a viewfinder and a taking lens changeable in focal length between at least two different focal lengths: a relatively short focal length suitable for wide-angle photography and a relatively long focal length suitable for telephotography and that allows close-up photography when the taking lens is changed to have the long focal length. The viewfinder has at least one movable lens which is axially moved and shifted away from the optical axis of the finder with respect to the axis of the taking lens when the taking lens is changed in focal length, to deflect the optical axis of the finder in order to cancel parallax error, depending on object distance.

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