Browse Prior Art Database

SPLIT TRANSFER COROTRON SHIELD DESIGN CONCEPT

IP.com Disclosure Number: IPCOM000027285D
Original Publication Date: 1996-Feb-29
Included in the Prior Art Database: 2004-Apr-07
Document File: 2 page(s) / 78K

Publishing Venue

Xerox Disclosure Journal

Abstract

An electrostatic field is required to achieve image transfer to a copy sheet in an electrophotographic printing machine or copier. The electrostatic field is provided by a corotron having a dynamic current representing the difference between supplied current and return current. The dynamic current is the transfer field control mechanism which is monitored by sensing the return current flowing through the corotron shield. In order to monitor shield current, the corotron shield must be isolated from machine ground, other current sources, and returned back to an appropriate power supply. This is easily achieved with for a single device corotron. However, for a dual corotron sharing a common shield such as a transfer and detack corotron, total current delivered to the multiple devices limits performance and stresses copy substrates. As a corrective action, it is proposed that the common shield be split into two elements.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 69% of the total text.

Page 1 of 2

XEROX DISCLOSURE JOURNAL

SPLIT TRANSFER COROTRON SHIELD DESIGN CONCEPT Fernando P. Yulo
Robert A. Gross

Proposed Classification

U.S. C1.355/221 Int. C1. G03g 15/02

XEROX DISCLOSURE JOURNAL - Vol. 21, No. 1 January/February 1996 41

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

Page 2 of 2

SPLIT TRANSFER COROTRON SHIELD DESIGN CONCEPT (Cont'd)

An electrostatic field is required to achieve image transfer to a copy sheet in an electrophotographic printing machine or copier. The electrostatic field is provided by a corotron having a dynamic current representing the difference between supplied current and return current. The dynamic current is the transfer field control mechanism which is monitored by sensing the return current flowing through the corotron shield. In order to monitor shield current, the corotron shield must be isolated from machine ground, other current sources, and returned back to an appropriate power supply. This is easily achieved with for a single device corotron. However, for a dual corotron sharing a common shield such as a transfer and detack corotron, total current delivered to the multiple devices limits performance and stresses copy substrates. As a corrective action, it is proposed that the common shield be split into two elements.

The accompanying Figure illustrates the concept which may be applied to a variety of designs including an isolated spot on the shield. Referring to the Figure, there is shown a dual corotron 10 providin...