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AUTOMATIC GAIN CORRECTION (AGC) VIDEO CORRECTION

IP.com Disclosure Number: IPCOM000026659D
Original Publication Date: 1993-Feb-28
Included in the Prior Art Database: 2004-Apr-06

Publishing Venue

Xerox Disclosure Journal

Abstract

In a raster input scanner of the type having a transparent platen on which the document to be scanned rests, a movable carriage bearing a scanning array such as a CCD for scanning the platen and the document thereon line by line, and a scan lamp to illuminate the document line being scanned, automatic gain correction or AGC typically performs two functions. In addition to dynamically correcting for short term and long term variations in the light output of the scan lamp, AGC circuitry also compensates for component variations which remain fixed in any particular scanner.