Eastman-kodak Company

Salvatore Leone

Donald Saul Rimai

Thomas Nathaniel Tombs

Paul M Borsenberger

Marie B O'Regan

Orville C Rodenberg

Peter S Alexandrovich

William Mey

William K Goebel

Catherine D Newell

Andrew J Mauer

Barrett L Gady

Francis M Paczkowski

Susan Pike Farnand

A method of producing images includes forming an electrostatic latent image on a primary image forming member. A toner image is developed on the primary image forming member using a developer comprising dry toner particles having a mean volume weighted diameter D between 5 .mu.m and 10 .mu.m. The toner particles contain particulate addenda in a concentration range between (3.2/D)% and (5.6/D)%. The toner image is electrostatically transferred from the primary image forming member to an intermediate transfer member having a compliant layer, and then electrostatically transferred from the intermediate transfer member to a receiver.

Optimized particulate surface treatment concentration for

A method and apparatus for reducing triboelectrically generated background development on a photoconductive primary image member bearing an electrostatic latent image pattern including background portions. In an electrophotographic black and white or color copier/printer, the primary image member is moved through a development zone. The image member includes a photoconductive element and a thin protective overcoat layer, the overcoat layer being between 0.1 .mu.m and 15 .mu.m in thickness and of a composition having between about 0.1% and about 10% by weight of a material that is an ionic conducting material and containing an electronegative group. The latent electrostatic image pattern is formed on the overcoat layer. Electrographic developer includes hard magnetic carrier particles and electrically insulative toner particles and moves through the development zone in contacting developing relation with the electrostatic charge pattern. The developer is transported through the zone in response to rotation of a series of alternating polarity magnets formed in a core which effects tumbling of the carrier in the development zone. The toner particles are tribocharged so that substantially all of the particles are negatively charged and the toner particles have a volume weighted diameter of less than 9 .mu.m.

Eliminating triboelectrically generated background in an

An improved method and apparatus for robust transfer of toner images using toner particles having a volume average diameter between about 2 .mu.m and about 9 .mu.m is described. Surprisingly good electrostatic transfer is obtained when the surface charge density of the toner is between 3.0.times.10.sup.-9 coul/cm.sup.2 and 6.5.times.10.sup.-9 coul/cm.sup.2 and when this toner is used in conjunction with a compliant transfer intermediate.

Optimal toner charge for use with a compliant transfer intermediate

Unexpectedly good transfer of electrophotographically-produced images using small toner particles occurs when the image is developed on an electrostatographic recording member, preferably an organic photoconductive element, which has been overcoated with a thin (about 10 nm to about 10 .mu.m thick) layer of a material having a Young's modulus greater than 10 GPa and preferably greater than about 100 GPa. The image is then transferred to an intermediate member which is comprised of an elastomeric blanket between about 0.1 and about 3 cm thick, having a Young's modulus between about 0.5 MPa and about 50 MPa, and preferably between about 1 and about 10 MPa, and having an electrical resistivity between about 10.sup.6 ohm-cm and about 10.sup.12 ohm-cm, by applying an appropriate electrostatic potential between the transfer intermediate member and the photoconductive element. The toned image is transferred from the intermediate transfer member to the receiver by applying an electrostatic field between the receiver and the intermediate transfer member. The blanket material comprising the intermediate transfer member should be overcoated with a thin (between about 0.1 .mu.m and about 25 .mu.m thick) layer of a material having a Young's modulus greater than about 100 MPa and preferably greater than about 1 GPa.

Electrostatographic apparatus and method for improved transfer of small

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

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.

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Rochester, NY, United States of America

Salvatore Leone