Patent · US Expired

Camera apparatus for preventing double-exposure of film returned to a self-thrusting cassette

US4994833A · kind A · utility

29Cited by
2References
3Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMar 12, 1990
Grant dateFeb 19, 1991
Priority date
Expiry dateMar 12, 2010

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03B2217/266
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

In a camera for exposing a filmstrip normally stored in a light-tight cassette which is inherently capable of thrusting the filmstrip out of the cassette regardless of the exposure condition of the filmstrip but has a film-exposure status indicator movable from an unexposed position for providing a visible indication that the filmstrip is generally unexposed, to a partly exposed position for providing a visible indication that the filmstrip is partly exposed, and to an exposed position for providing a visible indication that the filmstrip is substantially exposed, apparatus is provided for preventing exposure of the filmstrip when the status indicator is in its exposed position and for permitting exposure of the filmstrip when the status indicator is in its unexposed or partly exposed position.

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