Xerox Corporation

Larry G Hogestyn

Nero R Lindblad

Neil A Frankel

William H Wayman

Delmer G Parker

Daniel M Bray

Edward J Gutman

Kenneth W Pietrowski

Robert E Grace

Rasin Moser

Samuel P Mordenga

Darryl L Pozzanghera

Charles M Gardiner

Clive R Daunton

Jeffrey C Folkins

Kenneth L Timmons

An image transfer apparatus with the capacity to reduce or clean wire history. The cleaning is performed by supplying a voltage burst to shift, relative to nominal, the D.C. component of the electrode bias relative to the electrical bias of the donor member during the movement of the inter-imaging region through the development zone. A voltage shift may also be applied to electrically bias the donor member relative to the photoreceptor belt during the movement of the inter-imaging region through the development zone. These voltage shifts may be conducted individually or simultaneously.

Hybrid scavengeless development using direct current voltage shift to remove wire history

A preconditioning process and dual electrostatic brush cleaning apparatus for reducing adhesion of toner particles on the photoreceptor surface such that cleaning of the photoreceptor is enhanced. Preconditioning of the brush and/or the photoreceptor in the cleaning apparatus allows for cleaning of dual polarity toners, CAD toners and DAD toners. The preconditioning of the brush does not need replenishing once the print operation begins due to the electrostatics that maintain a constant predetermined level of toner in the brush.

Preconditioning of photoreceptor and cleaner brush

Developer A.sub.t is modified using a magnetic brush structure disposed in an admix channel of a developer housing. The brush structure includes a stationary magnet arrangement, a rotating shell and a trim bar. A variable speed motor is provided for rotating the shell at different speeds for controlling developer triboelectrification performance.

Developer at modification using a variable speed magnetic roller in an

Pre pretransfer treatment for multiple toner toner images increases the operating latitude for pretransfer/transfer. In one embodiment of the invention, a pre pretransfer corona device is used to drive the tribos of two multiple toner images toward each other prior to pretransfer. A single constant current corona discharge device is used in this embodiment. Subsequent pretransfer treatment serves to reduce the delta tribo between the two images thereby providing an operating latitude of 3 micro coul/g.

Pre-pretransfer treatment to increase transfer latitude in tri-level

A printing machine of the type including an image receiving member having a charge retentive surface with a first developed image being disposed in a first zone and a second developed image being disposed in a second zone is provided. The printing machine preferably including a corona generator positioned adjacent the charge retentive surface and characterized by an electrical parameter; a first control device for setting the electrical parameter to a first level for disposing the first developed image at a first charge level as the first developed image is passed by the corona generator; a second control device for changing the electrical parameter to a second level for disposing the second developed image at a second charge level as the second developed image is passed by the corona generator; and a cleaning member, contacting the charge retentive surface, for substantially removing both the first developed image and a portion of the second developed image from the the charge retentive surface, wherein the capacity of the cleaning member to remove the first developed image and the portion of the second developed image from the charge retentive surface depends on the magnitudes of the first and second levels.

Apparatus and method for removing developer material

In an electrostatograhic imaging device of the type forming a multilevel electrostatic latent image on a surface of the imaging member, and developing the multilevel electrostatic latent image with at least two types of toner, and a brush cleaner for removal of toner and debris remaining after transfer of the image to another surface, the brush is maintained in a condition loaded with a first toner type providing abrasive characteristics at the fibers of the brush, for abrading the photoreceptor for removal of toner of said second type.

Method and apparatus for increasing toner loading of a cleaning brush

An electrophotographic printing machine in which an electrostatic latent image is recorded on a photoconductive surface. One portion of the latent image is a discharged area with the other portion of the latent image being a charged area. The discharged image area is developed with toner particles of a first color and polarity by a first developer unit. No greater than 2% by volume of these toner particles have a diameter greater than about 20 microns. The first developer unit generates a weak magnetic field in the development zone and a strong magnetic field at the entrance and exit of the development zone. A second developer unit develops the charged image area with toner of a second color and polarity. The colors of the toners are different from one another.

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Ontario, NY, United States of America

Larry G Hogestyn