Xerox Corporation

Robert W Anderson

Oscar G Hauser

Frank C Genovese

Lawrence M Hart

Susan J Kremer

Joseph C Mammino

Grace T Brewington

Richard L Schank

Donald S Sypula

Geoffrey M Foley

Dennis A Abramsohn

Paul C Julien

Steven B Bolte

Michael L Grande

Raymond W Stover

Michael Poleshuk

Deborah J Nichol-Landry

Richard W Bigelow

A process for the preparation of colored toners which comprises providing a first toner comprised of resin, pigment particles, internal charge additive, and optional surface additives; adding thereto a second toner comprised of resin, pigment particles, internal charge additive, and optional surface additives; and wherein said toners contain blend compatibility components.

Toner compositions with blend compatibility additives

Disclosed is a process for forming two-color images which comprises (1) charging an imaging member in an imaging apparatus; (2) creating on the member a latent image comprising areas of high, intermediate, and low potential; (3) developing the low areas of potential with a colored developer comprising a colored first toner comprising a polymer resin selected from the group consisting of styrene-butadiene copolymers, styrene-acrylate copolymers, styrene-methacrylate copolymers, and mixtures thereof, a blue first colored pigment of the formula C.sub.32 H.sub.16 N.sub.8 Cu, a cetyl pyridinium chloride charge control agent, a 3,5-di-tertbutyl salicylate compound charge control agent, colloidal silica surface external additives, and metal stearate salt surface external additives; a colored second toner comprising a polymer resin selected from the group consisting of styrene-butadiene copolymers, styrene-acrylate copolymers, styrene-methacrylate copolymers, and mixtures thereof, a cyan second colored pigment of the formula C.sub.104 H.sub.164 N.sub.12 O.sub.8 S.sub.4 Cu, a charge control agent selected from the group consisting of distearyl dimethyl ammonium methyl sulfate and distearyl dimethyl ammonium bisulfate, colloidal silica surface external additives, and metal stearate salt surface external additives; and a color carrier comprising a core and a coating selected from the group consisting of methyl terpolymer, polymethyl methacrylate, and a blend of from about 35 to about 65 percent by weight of polymethylmethacrylate and from about 35 to about 65 percent by weight of chlorotrifluoroethylene-vinyl chloride copolymer, wherein the coating contains from 0 to about 40 percent by weight of the coating of conductive particles; (4) subsequently developing the high areas of potential with a black developer comprising a black toner comprising a second resin present selected from the group consisting of polyesters, styrene-butadiene polymers, styrene-acrylate polymers, styrene-methacrylate polymers, and mixtures thereof, a black pigment, and a charge control additive; and a black carrier comprising a core and a coating selected from the group consisting of chlorotrifluoroethylene-vinyl chloride copolymer containing from 0 to about 40 percent by weight of conductive particles; polyvinylfluoride; and polyvinylchloride; and (5) transferring the developed two-color image to a substrate.

Tri-level imaging processes with adjustable color

An ionographic imaging member has a conductive layer overcoated by a charge accepting layer. Overcoating layers of acrylate, polycarbonate, polyester, polyurethane, acrylic homopolymer or copolymer and the like are provided. Blocking layers may be provided for preventing charge injection and reducing surface charge decay and bulk charge trapping. The charge accepting layer may be doped with a charge clocking material for preventing charge injection. The overcoating and blocking layers may be one and the same.

Blocking and overcoating layers for electroreceptors

In an ionographic device projecting a modulated stream of ions in imagewise fashion towards a moving imaging surface, including an ion printing head having an ion chamber supporting a coronode held at a voltage V.sub.C to produce ions for deposit on an imaging surface and a modulation channel extending from the ion chamber towards the imaging surface through which a stream of ions is directed for imagewise modulation by a plurality of modulation electrodes, electric field distribution within the ion chamber is controlled by selectively varying voltages along the surface regions of the ion chamber to different voltage levels, in an arrangement causing focusing of ion density in the area of the ion chamber adjacent to the modulation channel. An increased ion density in the area of the ion chamber adjacent to the modulation channel assists in providing an increased corona current at the output of the device.

Method and apparatus for increasing corona efficiency in an ionographic

In an ionographic device projecting a stream of ions towards a moving imaging surface, modulated in imagewise fashion, one or more control electrodes may be arranged adjacent to the path of the ion stream and between the source of the modulated ion stream and the imaging surface, biased with a voltage preventing previously deposited charge from perturbing 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.

Method and apparatus for controlling ion trajectory perturbations in

A distributed resistance corona generating device includes an insulating substrate, a resistive material layer deposited on the substrate to a uniform thickness, and a plasma gap separating the resistive material layer into at least two resistive material regions. A voltage is applied to the resistive material regions through electrodes arranged on the resistive material regions so that a uniform resistance is provided between the power supply and the points on the resistive material regions immediately adjacent to the plasma gap. The distributed resistance corona generating device is inherently self regulating to provide a uniform charging potential along the plasma gap.

Distributed resistance corona charging device

A web having phosphor particles uniformly distributed on at least one outer surface of the web, the phosphor particles being substantially white or colorless under ambient room light illumination and which upon excitation by ultraviolet light phosphoresces to emit visible radiation having a wavelength between about 400 nanometers and about 500 nanometers for a detactable period after ultraviolet excitation. Imaged webs having phosphor particles uniformly distributed on at least one outer surface thereof may be employed in an imaging process the steps of illuminating the outer surface bearing an image with ultraviolet light during an electrostatographic imaging cycle to cause the phosphor particles to emit visible light, terminating the illumination of the outer surface bearing the image with the ultraviolet light, detecting the visible light emitted by the phosphor particles and altering at least one element of the electrostatographic imaging cycle in response to the detection of the visible light whereby the electrostatographic imaging cycle is disabled.

System for prevention of unauthorized copying

A thermally activated image bar is disclosed for use in an electrophotographic printer. The image bar comprises at least one transparent prism having a surface closely spaced and parallel with a confronting surface of a transparent member containing an array of transparent heating elements and addressing electrodes thereon to form a gap therebetween. A liquid medium also capable of transmitting light and having an index of refraction matched to that of at least one prism is positioned in the gap. An optical shield bonded to one of the confronting surfaces has at least one aperture aligned with the heating elements to improve optical contrast. This assembly is hermetically sealed within a transparent housing and means are optionally provided to circulate the liquid medium. The heating elements are selectively energized in response to digitized data signals for pulse heating the portions of the liquid medium in the vicinity thereof to form momentary bubbles. The bubbles cause changes in the index of refraction of the medium in the gap, so that selected portions of a sheet of light directed through the prism and into the bubbles are deflected or modulated by the mechanism of total internal reflection. The modulated light may be blocked by a stop or shutter and the unmodulated light may be directed to the precharged photoconductive member of the printer to form latent images or vice versa. Several configurations of the image bar are disclosed for producing latent electrostatic images on a photoconductive member one line of picture elements or pixels at a time. In one embodiment, the optical shield contains a plurality of tunnels which are aligned with the heating elements, so that the bubbles produce a self-pumping action that causes circulation of the liquid medium.

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Fairport, NY, United States of America

Robert W Anderson