Edwardo D Lara Deceased521 N Kingston St, Gilbert, AZ 85233

5055862, Oct 8, 1991

Dec 20, 1989

7/454086

Lorin K. Hansen - Fremont CA
Richard J. Gable - Mountain View CA
Edwardo D. Lara - Sacramento CA
William A. Lloyd - Los Altos CA
Keith E. McFarland - Woodside CA
Jack H. Sayre - San Jose CA
Stephen D. White - Santa Clara CA

Xerox Corporation - Stamford CT

G01D 1506

346154

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.

5061948, Oct 29, 1991

May 30, 1990

7/532467

Lorin K. Hansen - Fremont CA
Edwardo D. Lara - Sacramento CA
William A. Lloyd - Los Altos CA
Jack H. Sayre - St. John, CA
Stephen D. White - Santa Clara CA

Xerox Corporation - Stamford CT

G01D 1506

346155

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.