Xerox Corporation

Jack H Sayre

Stephen David White

Lorin K Hansen

William A Lloyd

Keith E McFarland

Edwardo D Lara

Richard J Gable

In a device for producing an electrostatic image along a scan line of a recording medium by means of a recording device including an array of stylus electrodes arranged in a series of groups cooperable with a series of complementary electrodes, each of the stylus electrode groups cooperates with a portion of two adjacent complementary electrodes whereby writing is accomplished by imposing a charge pattern upon the recording medium in the region of a stylus electronic group when both the stylus electrode group and its cooperating pair of complementary electrodes are actuated contemporaneously. As each complementary electrode is actuated it induces a non-uniform residual potential distribution in the recording medium of a portion of the region of the next adjacent stylus electrode group. The electrostatic writing method comprises first perturbing a region of the recording medium by imposing a first non-uniform residual potential distribution on one portion thereof coextensive with the overlapping portion of a complementary electrode, then perturbing another portion of the same region by imposing a second non-uniform residual potential distribution thereon coextensive with the overlapping portion of another adjacent complementary electrode, wherein the first and second non-uniform residual potential distributions tend to cancel one another, and then writing a charge pattern upon the entire region.

Electrographic marking with modified addressing to eliminate striations

A preferred embodiment of the present invention is directed to a removal of a ghost image created during a processing of a film laminate medium by an electrographic plotter. A recording of an image on the film medium induces a ghosting potential over a developing station. The ghosting potential causes a spurious image to be developed by the developing station. The recorded image is created by depositing a charge on a dielectric layer of the film. A relationship exists between the deposited charge and the ghosting potential. By use of information known to the system, the ghosting potential may be estimated and reduced. A preferred method estimates the magnitude of the ghosting potential by use of the relationship between deposited charge and ghosting potential. A counteracting potential is applied to the system to reduce the ghosting potential over the developing station. The reduction of the ghosting potential substantially removes the ghost image created during the processing of the film laminate.

Film ghost removal in electrographic plotters by voltage bias of the

A method of producing an electrostatic image along scan lines of a recording medium with recording means including a series of stylus electrodes arranged in a longitudinally extending array and divided into two groups, with the stylus members of each group being connected in parallel with one another along the array. A series of complementary electrodes is arranged in a longitudinally extending array and cooperates with sets of stylus electrodes for depositing a charge pattern upon a selected region of recording medium when the sets of stylus electrodes and selected complementary electrodes are pulsed contemporaneously. The method comprises the steps of delivering data, comprising a writing potential or a non-writing potential, to the stylus electrodes of both groups, and overriding certain of the data with a non-writing potential for defining the sets of stylus electrodes within the groups.

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St. John, Canada

Jack H Sayre