Xerox Corporation

Eric J Schneider

Zhigang Fan

Jeffrey J Folkins

William W Limburg

Robert C Yu

John Wei-Ping Lin

Keith T Knox

Lesley P Dudek

Joseph G Schram

A method and apparatus are described for detecting photocopier tracking signatures placed on documents produced by color photocopiers. The apparatus includes an input terminal that supplies digital image data representing an input document produced by a color photocopier. The digital image data includes a plurality of pixel values grouped together to form a plurality of color separations that represent the input document. The apparatus also includes an image processing unit that generates an output image based on the digital image data. The image processing unit generates the output image based on differences between corresponding pixel values of at least two of the plurality of color separations. The apparatus further includes an ouput terminal for displaying the output image to view the photocopier tracking signature. Color differences can be detected by combining two or more of the color separations into a resulting monochromatic image and then enhancing the resulting color differences. The combination of the separations exposes small color differences that are not detectable in any of the individual separations, thus enabling the photocopier signature to be detected.

Method and apparatus for detecting photocopier tracking signatures

An apparatus for cleaning a charge retentive surface of a photoreceptor which includes a cleaning blade for removing debris from the charge retentive surface of a photoreceptor. In the environment of a xerographic copier and/or printer, corona effluents are emitted by the high voltage charging devices. These effluents, which are strong oxidizing agents, may be adsorbed by or otherwise attach a cleaning blade polymer matrix. Thereafter, such corona species outgassing from a blade may chemically and/or otherwise attack the photoreceptor during prolonged blade/photoreceptor contact, resulting in print/copy defects, as well as permanent damage to the photoreceptor and/or cleaning blade. The present invention relates to impregnating or otherwise treating the cleaning blade with an antioxidant such that its presence in the blade polymer matrix can prevent corona species penetration or accumulation by chemically neutralizing and destroying the species upon exposure. In one example, the cleaning blade is impregnated with an antioxidant such as 1,3-Diphenylisobenzofuran. Such preventive measures to hinder or eliminate the corona species absorption and accumulation in the cleaning blade polymer matrix can, in principle, be employed to resolve the corona species outgassing problem.

Photoreceptor cleaning apparatus and method

An apparatus for developing a latent image recorded on a photoconductive member in an electrophotographic printing machine having a reservoir for storing a supply of developer material and a magnetic rush roll for transporting material from the reservoir to each of two donor rolls. The developer material has carrier granules and toner particles. The donor rolls receive toner particles from the magnetic brush roll and deliver the toner particles to the photoconductive member at spaced locations in the direction of movement of the photoconductive member to develop the latent image recorded thereon.

Developing device with dual donor rollers including electrically biased

In an ionographic device projecting a stream of ions towards a moving imaging surface, modulated in imagewise fashion, an array of control electrodes corresponding to the ion stream modulating array of electrodes, is arranged adjacent to the path of the ion stream and between the source of the modulated ion stream and the imagaing surface, biased with a voltage preventing previously deposited charge from pertubing the trajectory of subsequently projected ions to limit the amount of ion beam deflection caused by the presence of electrostatic charge patterns on the electroreceptor. The control electrode voltage increases with the period over which the modulation electrode has allowed the flow of ions therepast.

Method and apparatus for controlling ion trajectory perturbations in

An electrophotographic imaging member is disclosed comprising a conductive layer, a charge transport layer comprising an aromatic amine charge transport or hydrazone molecule in a continuous polymeric binder phase, and a contiguous charge generation layer comprising a photoconductive material, a polymeric binder and a hydroxyaromatic antioxidant. An electrophotographic imaging process using this member is also described.

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Webster, NY, United States of America

Eric J Schneider