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:
Jun. 08, 1993
Filed:
Jun. 21, 1991
William H Purdy, Seattle, WA (US);
Other;
Abstract
A motion picture film monitor structured and operated in the film path of a film projector, having a plurality of film support rollers for supporting the film as it passes adjacent a plurality of sensors. The plurality of sensors includes at least one proximity sensor positioned preferably adjacent one of the guide rollers and when more than one proximity sensor is spaced closely to each other, a different frequency is used by each proximity sensor. In addition, an optical film presence detector including a light emitter and a light sensor is positioned adjacent another support roller such that when the film passes the film presence detector, it is supported by the roller. A film motion detector using a similar optical system is positioned adjacent one of the support rollers which supports the film in close proximity to the sensor. Electronic circuitry and connections therefore, are structured to allow for a logically configured and miniaturized monitor. An electronic circuit may be used to expand the control capabilities of the monitor.