Patent · US Expired

Automatic rewinding camera

US4400074A · kind A · utility

21Cited by
5References
25Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 1, 1982
Grant dateAug 23, 1983
Priority date
Expiry dateMar 1, 2002

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03B17/425
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

An automatic rewinding camera wherein an automatic advance of the photographic film by one frame is caused by shutter release operation and rewinding of the photographic film is automatically started when the film is prevented from further advance. The camera has a film-driven sprocket wheel, by the rotation of which film movement signals are produced. A timer circuit maintains, during the passage of a predetermined active time which is shorter than the time required to advance the photographic film by one frame, the camera motor in forward rotation so as to advance the photographic film. The timer circuit is reset by the film movement signals. But when those film signals stop, that is, when the film is fully extended from the cartridge, then the timer is not reset; and the measurement of the full predetermined active time, by the timer, without resetting, results in the motor being reversed to rewind the film.

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