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. 24, 1980
Filed:
Apr. 26, 1978
David G Stites, Elgin, IL (US);
John R Flint, Barrington, IL (US);
Michael L Kreuser, Evanston, IL (US);
Bell & Howell Company, Chicago, IL (US);
Abstract
A film transport mechanism moves film from area to area and then stops it to project an image. During the period while the film is being transported, the lens is shuttered and glass flats on either side of the film are opened. This way, the viewer does not see a blurred montage of images being moved across a screen at a high rate of speed, and there is a much less chance of scratching film. The shutter may be either a mechanical blade which cuts across a beam of light or an electrical circuit which dims a light supply to darken the screen. Dimming is preferred to switching a lamp off or on since it is much less damaging to a filament if it remains continuously energized.