Eastman-Kodak Company

Orville C Rodenberg

William Mey

Edward T Miskinis

Salvatore Leone

Susan E Riblett

Donald Saul Rimai

Michel Frantz Molaire

John W May

George R Walgrove, Iii

William T Gruenbaum

Richard C Baughman

Gary B Bertram

Bijay S Saha

Kelly Stephen Robinson

Paul L Nielsen

James F Paxon

James C Minor

Catherine D Newell

Andrew J Mauer

William Joseph Hagen

Bruce D MacLellan

David L Dunaway

Francis M Paczkowski

Rose M Bothner

Susan Pike Farnand

Susan E Ribletty

Magnetic carrier particles are removed from a photoconductive image member by subjecting the carrier particles to a magnetic field while or after exposing the photoconductive image member to erasing radiation in the absence of a substantial electrical field affecting the carrier particles.

Method and apparatus for scavenging carrier employing a magnetic field

The present invention relates to carrier particles which are used in image reproduction machines that include a magnetic brush for cleaning an imaging member. These carrier particles are utilized by the magnetic brush to clean the imaging member. The carrier particles include magnetic particles having a particle size distribution ranging from about 150 microns in diameter to about 1 micron in diameter. Preferably at least about 50% by weight of the magnetic particles have a diameter of less than about 45 microns. Preferably the carrier particles have an aspect ratio of about 8 and are made of stainless steel or iron.

Size distribution of carrier particles for use in a magnetic brush

In electrographic apparatus a latent image on a flexible photoconductor is developed with toner particles at a development station and subsequently transferred to a receiver sheet, such as a copy sheet, and then fused to the sheet. Sometimes unwanted particles are on the photoconductor, including the area where an image is to be developed on the photoconductor. These particles are removed by a magnetic brush system located closely adjacent the surface of the photoconductor prior to the charging station. By means of a pair of tapered skis the cleaning pressure across the photoconductor is maintained at a uniform pressure during cleaning of the photoconductor so that the photoconductor is uniformly cleaned.

Tapered ski supports for a film cleaning device

An electrostatographic copier/printer has an image member with at least one portion which can selectively be imaged to receive an electrostatic image to be toned. A toning station is operable to bring the developer into contact with the image member portion so as to produce a toner image according to the electrostatic image if the portion has been imaged and to leave a small amount of background toner uniformly deposited if the image member portion has not been imaged. The background toner on the non-imaged portion serves to assist subsequent detack operation. A plurality of different color toning stations may be provided, and, if so, the black toner toning station is preferably used to leave the background toner.

Detack enhancement for electrostatographic document copiers/printers

A photoconductor element is provided that has non-blurring latent image keeping memory which is suitable for multiple electrophotographic copying from a single imaging step. The element preferably incorporates a charge generation layer which comprises a phthalocyanine dye or pigment. The copying method involves simultaneous application of corona charge and an image exposure to the element followed by uniform irradiation of the element. Thereafter a plurality of copies can be made by the step sequence of toner deposition, toner transfer, and toner heat fusion to a receiver.

Photoconductor element for making multiple copies and process for using

A xeroprinting master is formed by depositing a corona charge injection modifying material on a master substrate which includes a charge transport layer. The material can block the injection of charge that would otherwise inject into the charge transport layer or it can inject charge that would otherwise remain on the surface of the master. Preferably, the deposit is made by a conventional printer such as an ink jet, impact or thermal printer and the resulting deposit is not fused before use in xeroprinting.

Xeroprinting using a corona charge injection modifying material

Color toner images are transferred in registry to a receiving sheet held on a transfer drum. To facilitate releasing the sheet with the last image the drum surface is roughened, providing at least 0.002 inches between peaks and valleys. To offset difficulties created by such roughening in initial securing of the sheet to the drum, a transfer field is not applied as the leading edge of the sheet leaves the nip. The transfer field is applied after a short portion of the sheet, for example, 0.25 inches has left the nip.

Multicolor image transfer method and apparatus

Xeroprinting is performed without fusing a master toner image. A master toner image is made by conventional electrophotography, for example, by charging, imagewise exposing and applying toner to a photoconductive imaging member to create a first toner image. The first toner image is charged with charges of a first polarity opposite that of the toner image and the member is erased with erase illumination through its base. This creates a toner image with a charge opposite that of the original toner image which is tightly held by opposite charges which have migrated to the portion of the electrophotosensitive member just under the toner. The imaging member is then toned again with toner of the same polarity as the original toner to create a second toner image that overlies the first toner image. The imaging member is again erased through its base, and the second toner image is transferred to a receiving sheet without disturbing the first toner image. The toner image may then be used as a master to repeat the process but without the necessity of creating the master toner image again.

Charge retention xeroprinting

In multi-color reversal development, good color balance is obtained by changing the time duration of exposure for each different color frame. A dot printer apparatus produces a series of different color-resolved electrostatic latent images on a recording member. The apparatus includes an array of discrete elements for dot recording on the recording medium. The elements are selectively enable for predetermined periods of time during a cycle of operation to form a color-resolved electrostatic latent image on the recording member. Each charge latent image is developed with selected toner particles according to its resolved color. A control signal representative at least in part of the resolved color of each latent image is produced, and the control signal determines the enablement time of the elements during each cycle of operation according to each resolved color.

Dot printer with toner characteristic compensation means

Electrically photosensitive materials comprising electrically photosensitive colorant particles dispersed in a liquefiable, electrically insulating carrier containing a binder polymer and electropolymerizable bisphenol-acrylate monomers or mixtures of such monomers are disclosed. The disclosed materials are employed in photoelectrophoretic processes wherein the colorant particles are caused to migrate by the action of light and an electric field, while the material is electrohardened by the electric field.

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Rochester, NY, United States of America

Orville C Rodenberg