Browse Prior Art Database

AUTOMATIC LAMP INTENSITY CONTROL FOR RASTER INPUT SCANNERS

IP.com Disclosure Number: IPCOM000025869D
Original Publication Date: 1988-Aug-31
Included in the Prior Art Database: 2004-Apr-04
Document File: 2 page(s) / 55K

Publishing Venue

Xerox Disclosure Journal

Abstract

Raster input scanners provide sensors for the detection of light reflected from or transmitted through the document. The sensors produce an output proportional to detected light intensity. Lamps used for the illumination of documents in such systems provide varying output responses over time, based on lamp aging and general lamp-to-lamp differences. Accordingly, control of the light source is an important aspect in optimum data acquisition.

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XEROX DISCLOSURE JOURNAL

AUTOMATIC LAMP INTENSITY Proposed Classification CONTROL FOR RASTER INPUT
SCANNERS
Int. C1. H04n
Richard H. Tuhro
David B. Baum
Alisa J. Farrell

U.S. C1.358

Raster input scanners provide sensors for the detection of light reflected from or transmitted through the document. The sensors produce an output proportional to detected light intensity. Lamps used for the illumination of documents in such systems provide varying output responses over time, based on lamp aging and general lamp- to-lamp differences. Accordingly, control of the light source is an important aspect in optimum data acquisition.

Because the output of the sensors is proportional to light intensity, the sensors may be used as part of the lamp control system. Sensor output is converted to a digital signal, in accordance with standard operation of raster input scanners. The digital information thus derived may be compared to a standard or reference value stored in the machine microprocessor control system. Based on the comparison, the result may be used to control a lamp power supply to vary the operating characteristics of the power supply driving the lamp.

Volume 13 Number 4 July/August 1988 223

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224

  XEROX DISCLOSURE JOURNAL Volume 13 Number 4 July/August 1988

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