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:
Aug. 19, 1980
Filed:
Jan. 08, 1979
Robert R Parker, Wheeling, IL (US);
Bell & Howell Company, Chicago, IL (US);
Abstract
A changeover control arrangement is provided for projection apparatus to allow two identical projection apparatus with identical changeover control arrangements and interconnected by a multi-conductor changeover interconnection cable to be utilized alternately and sequentially for multi-reel presentations or other projection formats requiring the operation of more than one projection apparatus. The changeover control arrangement of each projection apparatus includes a momentary actuated changeover control switch that is interconnected over the changeover interconnection cable to activate an illumination generating source; for example, an LED device. The illumination generating source has no electrical connections to the electrical or ground reference system of the projection apparatus in which the illumination generating source is physically disposed. The illumination generating source of each control arrangement is disposed adjacent a photosensitive transistor to render the photosensitive transistor conductive upon the illumination generating source being activated. The changeover control arrangement also includes circuitry to control the operation projection mode of the projection apparatus over a changeover control line connected to the photosensitive transistor. Upon operation of the momentary actuated changeover control switch of the first projection apparatus in the projection disabled mode, the illumination generating source in the second interconnected projection apparatus is activated over the changeover interconnection cable to render the photosensitive transistor conductive whereupon the changeover control line conditions the second projector apparatus to the projection disabled mode. In the audio and visual disabled mode, a circuit path provided by the control circuitry and changeover control arrangement of the second projector apparatus is removed to condition the first projection apparatus to the projection enabled mode.