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MAIN FLASH LAMP TO PROVIDE PRE-FLASH FUNCTION

IP.com Disclosure Number: IPCOM000027057D
Original Publication Date: 1995-Feb-28
Included in the Prior Art Database: 2004-Apr-07
Document File: 2 page(s) / 53K

Publishing Venue

Xerox Disclosure Journal

Abstract

In an electrophotographic printing machine, it is frequently desirable to illuminate the original document before exposure thereof. This determines the reflectivity of the document. With the reflectivity known, the processing components within the printing machine may be suitably adjusted. Heretofore, this pre-exposure function has been achieved by a unique flash lamp and circuitry. However, the pre-flash light output is not consistent flash to flash and causes copy to copy quality variations. In lieu of the pre-flash lamp and circuitry, one of the main flash lamps may be used to achieve the pre-flash function. A separate trigger signal fires the lamp for pre-flash using the boost voltage without interrupting the charging of the main capacitors to fire the lamps during the main flash. This achieves the pre-flash function more uniformly and minimizes copy quality degradation.

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XEROX DISCLOSURE JOURNAL

MAIN FLASH LAMP TO PROVIDE PRE-FLASH FUNCTION US. C1.355/228 John A. Minchak

Proposed Classification

Int. C1. G03g 15/04

In an electrophotographic printing machine, it is frequently desirable to illuminate the original document before exposure thereof. This determines the reflectivity of the document. With the reflectivity known, the processing components within the printing machine may be suitably adjusted. Heretofore, this pre-exposure function has been achieved by a unique flash lamp and circuitry. However, the pre-flash light output is not consistent flash to flash and causes copy to copy quality variations. In lieu of the pre-flash lamp and circuitry, one of the main flash lamps may be used to achieve the pre- flash function. A separate trigger signal fires the lamp for pre-flash using the boost voltage without interrupting the charging of the main capacitors to fire the lamps during the main flash. This achieves the pre-flash function more uniformly and minimizes copy quality degradation.

XEROX DISCLOSURE JOURNAL - Vol. 20, No. 1 January/February 1995 43

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44 XEROX DISCLOSURE JOURNAL - Vol. 20, No. 1 January/February 1995

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