The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 17, 1977
Filed:
Aug. 01, 1975
Kayoshi Tsujimoto, Osaka, JA;
Minolta Camera Kabushiki Kaisha, Osaka, JA;
Abstract
A double-exposure proof camera includes a manual film advance and a solenoid which opens and closes the shutter with energization and de-energization of the solenoid. The solenoid is connected through a thyrister and a semi-conductor switch to a battery, the semi-conductor switch being closed and opened at the initiation and termination of a time interval determined by an RC network whose resistance component is controlled by a scene exposed photosensitive element. The thyrister gate is connected through a series connected pair of switches to a capacitor, one switch being closed with the depression of a shutter release member and the other switch being closed and opened respectively with a film frame being in exposure position and the film frame being advanced to discharge. The capacitor is connected to the battery through a pair of parallel switches, one of which is manually closeable and the other is closed during the advance of the film. A single exposure per film frame is only permitted, except when the manual switch is closed to permit continuous capacitor charging and multiple exposure of a single frame.