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:
Oct. 21, 1986
Filed:
Oct. 15, 1982
Roger H Therrien, Waterloo, CA;
Maninderpal S Chahal, Kitchener, CA;
NCR Canada Ltd, Mississauga, CA;
Abstract
A system is disclosed for automatically controlling the light intensity of a light source as a function of the amount of light received by a photosensor. In a preferred embodiment the light source illuminates a reference background which, in turn, reflects the light incident thereon to a photosensor in a video camera. In response to this reflected light, the photosensor produces a video signal which is proportional to the amount of light reflected thereon. A first processor is responsive to the reception of the video signal over a preselected period of time and provides a first signal which is proportional to the amount of reflected light received by the photosensor over that preselected period of time. A second processor is responsive to the first signal and generater a control signal to automatically cause an adjustable power supply to change the voltage applied to the light source as a function of the amplitude of the control signal. The second processor is also controlled by a sensor signal initiated by the presence of the object to be copied.