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PRINT COROTRON INDUCTOR IN AN ION PROJECTION PRINTING DEVICE

IP.com Disclosure Number: IPCOM000026233D
Original Publication Date: 1990-Dec-31
Included in the Prior Art Database: 2004-Apr-05
Document File: 2 page(s) / 70K

Publishing Venue

Xerox Disclosure Journal

Abstract

In an ion projection printing device such as that disclosed in U.S. Patent No. 4,463,363 to Gundlach et al., a corona generating wire spans the entire length of the printing head in close proximity to the walls of the printhead body. Any perturbations in the corona wire, or passing air may result in the generation of an electric arc between the positively charged wire and the surrounding walls of the printhead. Concurrently, the arc causes a large current surge through an external corona supply wire which, in turn, generates an electromagnetic field of sufficient strength to disrupt the logic circuitry used to control the ion modulation electrodes of the device. Generally, this disruption will cause defects in the latent ionographic image that become visible upon development of the image. It is, therefore, desirable to reduce the effects of electromagnetic interference caused by corona arcing in an ion projection printing device.

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XEROX DISCLOSURE JOURNAL

PRINT COROTRON INDUCTOR IN AN ION PROJECTION PRINTING DEVICE Int. C1. Gold 15/06 John T. Buzzelli

Proposed Classification US. C1.346/159

In an ion projection printing device such as that disclosed in U.S. Patent No. 4,463,363 to Gundlach et al., a corona generating wire spans the entire length of the printing head in close proximity to the walls of the printhead body. Any perturbations in the corona wire, or passing air may result in the generation of an electric arc between the positively charged wire and the surrounding walls of the printhead. Concurrently, the arc causes a large current surge through an external corona supply wire which, in turn, generates an electromagnetic field of sufficient strength to disrupt the logic circuitry used to control the ion modulation electrodes of the device. Generally, this disruption will cause defects in the latent ionographic image that become visible upon development of the image. It is, therefore, desirable to reduce the effects of electromagnetic interference caused by corona arcing in an ion projection printing device.

The present invention utilizes an inductor, placed serially between the corona supply wire and the corona wire, to reduce electromagnetic interference caused by the arc power surge. For example, in an ion projection printing device having a corona wire charged to approximately +2400 Vdc and surrounding walls at a potential of approximately OVdc, a 2700 pH inductor, inserted seri...