Browse Prior Art Database

HYBRID PIN COROTRON/SCOROTRON ARRANGEMENT FOR CHARGING

IP.com Disclosure Number: IPCOM000025834D
Original Publication Date: 1988-Jun-30
Included in the Prior Art Database: 2004-Apr-04
Document File: 2 page(s) / 94K

Publishing Venue

Xerox Disclosure Journal

Abstract

The function of the xerographic charging system is to provide a uniform known electrical potential to the photoreceptor. To this end, the charging device, power supply and process controls are designed to operate together to compensate for imperfect photoreceptor behavior.

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XEROX DISCLOSURE JOURNAL

HYBRID PIN COROTRON/SCOROTRON Proposed Classification ARRANGEMENT FOR CHARGING U.S. C1.355/3CH Mark S. Jackson Int. C1. G03g 15/00

The function of the xerographic charging system is to provide a uniform known electrical potential to the photoreceptor. To this end, the charging device, power supply and process controls are designed to operate together to compensate for imperfect photoreceptor behavior.

Present practice in charging devices for negatively charged photoreceptors is the use of pin scorotrons, as described, for example, in United States Patent No. 4,725,732 to Lang et al. The biased screedgrid promotes uniform charging, and control of the grid potential allows charging to, without exceeding, the desired potential. Scorotrons generally suffer from inefficiency (low plate current to total current ratio), but the pin configuration aids this problem to some extent. The smaller corona volume, compared to similar wire devices, also greatly reduces the amount of ozone generated at a given total current.

Application of the pin scorotron to higher process speeds is complicated by the need for multiple pin arrays. This is driven only partially by the need to deliver more current to the photoreceptor. Because it is desired to allow time for the fast component of dark decay to go to completion under the charging device (to relieve stress on the process control system) there is a need for the charging device to grow linearly with the process speed. The result is large, expensive devices that even with the advantages of the pin configuration, ge...