Browse Prior Art Database

CURRENT FEEDBACK FAULT DETECTION FOR PRE-CLEAN DICOROTRONS

IP.com Disclosure Number: IPCOM000025902D
Original Publication Date: 1988-Dec-31
Included in the Prior Art Database: 2004-Apr-04
Document File: 2 page(s) / 104K

Publishing Venue

Xerox Disclosure Journal

Abstract

In pre-clean corotrons as found, for example, in the Xerox 1075 or 1090 copiers or the Xerox 5090 duplicator, D.C. current to the shield is monitored, and a fault is declared if the current value falls outside defined limits. This measurement assumes that current supplied by the power supply reflects what is delivered to the photoreceptor and toner. It is possible, however, that some of the supplied current is leaking to ground via an undesired ground path. If the current is leaking to ground, the toner under the pre-clean charging device will not be properly charged, and a cleaning failure will resu 1 t.

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XEROX DISCLOSURE JOURNAL

CURRENT FEEDBACK FAULT DICOROTRONS
Clark V. Lange

Classification Proposed DETECTION FOR PRE-CLEAN U.S. C1.355/3CH

Int. C1. G03G 15/00

34 30

18

I

.

16 32

12 14 T

Volume 13 Number 6 November/December 1988 30 5

[This page contains 1 picture or other non-text object]

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CURRENT FEEDBACK FAULT DETECTION FOR PRE-CLEAN D ICO ROTRONS (Cont'd)

In pre-clean corotrons as found, for example, in the Xerox 1075 or 1090 copiers or the Xerox 5090 duplicator, D.C. current to the shield is monitored, and a fault is declared if the current value falls outside defined limits. This measurement assumes that current supplied by the power supply reflects what is delivered to the photoreceptor and toner. It is possible, however, that some of the supplied current is leaking to ground via an undesired ground path. If the current is leaking to ground, the toner under the pre-clean charging device will not be properly charged, and a cleaning failure will resu 1 t.

As shown in cross-section in the Figure, dicorotron 10, for applying a charge to toner on photoreceptor surface 12, moving in direction 14, has a dielectric coated coronode 16, driven to charging operation with an A.C. power supply 18, supported within a generally U-shaped housing 20 having upper central portion 22, and legs 24,26 extending from the central portion towards charge retentive surface 12. A shield 28 is supported within housing 20, and is driven with a variable D.C. power supply 30 controlling the charging function. Housing 16 may be a plastic material, with the interior walls thereof covered with a conductive coating 32. The dicorotron is arranged to support coronode 16 parallel to...