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RAMP CHARGE DEVELOPMENT

IP.com Disclosure Number: IPCOM000025541D
Original Publication Date: 1986-Feb-28
Included in the Prior Art Database: 2004-Apr-04
Document File: 2 page(s) / 55K

Publishing Venue

Xerox Disclosure Journal

Abstract

In an electrophotographic printing machine, the development system employs an electrically biased developer roil. During printing machine cycie up and cycle down, the potential between the developer roll and photoconductive member is such that there IS potential on the developer roll and no potential on the photoconductive member. Under these circumstances, there 1s excessive wrong sign development, In order to solve this problem, the voltage on the developer roll and the voltage on the photoconductive member are controlled to ramp at the same time. ThLs minimizes the positive field and does not produce any negative fields. The system requires the use of a constant ramp circuit that converts an input step voltage and ramps the power supply to its proper level. Because of the different potentials that the photoconductive member and the developer roll are set at, the ramp times are different. The maximum error voltage occurs at the maximum voltage. This requires that the end of each ramp meet. This is achieved by calculating the difference in voltage between the photoconductive member and the developer roll and adjusting the turn on time of the developer roll ramp.

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XEROX DISCLOSURE JOURNAL

RAMP CHARGE DEVELOPMENT

Proposed Thomas A. Hayes, Jr. Classification

U.S. CI. 118/637

Int. C1. BQ5b 5/02

In an electrophotographic printing machine, the development system employs an electrically biased developer roil. During printing machine cycie up and cycle down, the potential between the developer roll and photoconductive member is such that there IS potential on the developer roll and no potential on the photoconductive member. Under these circumstances, there 1s excessive wrong sign development, In order to solve this problem, the voltage on the developer roll and the voltage on the photoconductive member are controlled to ramp at the same time. ThLs minimizes the positive field and does not produce any negative fields. The system requires the use of a constant ramp circuit that converts an input step voltage and ramps the power supply to its proper level. Because of the different potentials that the photoconductive member and the developer roll are set at, the ramp times are different. The maximum error voltage occurs at the maximum voltage. This requires that the end of each ramp meet. This is achieved by calculating the difference in voltage between the photoconductive member and the developer roll and adjusting the turn on time of the developer roll ramp.

Volume 11 Number 1 January/February 1986 5

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

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    XEROX DISCLOSURE JOURNAL
Volume 11 Number 1 January/February 1...