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Browse Prior Art Database

SCAVENGELESS DEVELOPER UNIT WITH ELECTRONICALLY COMMUTATED DONOR ROLL

IP.com Disclosure Number: IPCOM000027060D
Original Publication Date: 1995-Feb-28
Included in the Prior Art Database: 2004-Apr-07
Document File: 2 page(s) / 80K

Publishing Venue

Xerox Disclosure Journal

Abstract

U.S. Patent 5,289,240 to Wayman discloses a "scavengeless" developer unit for a xerographic printer. This developer unit includes a rotating donor roll for conveying toner particles to a charge-retentive surface for electrostatic development. The donor roll has defined on the surface thereof a set of longitudinal electrodes. By providing AC bias to these electrodes as the electrodes pass near the charge-retentive surface, the toner on the surface of the roll near the activated electrodes will detach from the roll to form a powder cloud near the charge-retentive surface. Particles in this powder cloud will adhere electrostatically to charged areas on the charge-retentive surface, to develop an electrostatic latent image.

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XEROX DISCLOSURE JOURNAL

SCAVENGELESS DEVELOPER Proposed Classification UNIT WITH ELECTRONICALLY US. C1.355/259 COMMUTATED DONOR ROLL
Int. Jeffrey J. Folkins C1. G03g 15/06

U.S. Patent 5,289,240 to Wayman discloses a "scavengeless" developer unit for a xerographic printer. This developer unit includes a rotating donor roll for conveying toner particles to a charge-retentive surface for electrostatic development. The donor roll has defined on the surface thereof a set of longitudinal electrodes. By providing AC bias to these electrodes as the electrodes pass near the charge-retentive surface, the toner on the surface of the roll near the activated electrodes will detach from the roll to form a powder cloud near the charge-retentive surface. Particles in this powder cloud will adhere electrostatically to charged areas on the charge-retentive surface, to develop an electrostatic latent image.

As the donor roll rotates, it is desirable to apply AC bias only to those longitudinal electrodes which happen to be passing near the charge-retentive surface at a particular time. Conventionally, the selective activation of desired electrodes could be performed by commutator brushes contacting the electrodes in the desired position near the charge-retentive surface. However, this brush-commutation may be a significant source of wear.

The commutation function, by which certain electrodes passing near the charge-retentive surface are AC biased, can be performed electronically. A...