Patent · US Expired

Stop device for photographic camera

US4897682A · kind A · utility

5Cited by
0References
7Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMay 13, 1988
Grant dateJan 30, 1990
Priority date
Expiry dateMay 13, 2008

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03B9/06
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A stop device having a plurality of stop blades pivotably disposed about an optical axis with an adjacent pair partially overlapping each other and adapted for defining an aperture opening with their inner edges. Each of the inner edges of the stop blades has a first inner edge portion for partially defining a circular aperture opening when the stop device is set to the full aperture position or a position equivalent thereto and a second inner edge portion for partially defining a substantially circular small aperture opening when the stop device is set to a predetermined intermediate aperture position for providing an aperture opening smaller than that provided in the full aperture position. Accordingly, this stop device is capable of providing the substantially circular aperture opening not only in the full aperture position but also in the predetermined intermediate aperture position.

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