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Browse Prior Art Database

SYSTEM AND METHOD EMPLOYING PULSES TO REDUCE IMAGE ARTIFACTS

IP.com Disclosure Number: IPCOM000026519D
Original Publication Date: 1992-Aug-31
Included in the Prior Art Database: 2004-Apr-06
Document File: 6 page(s) / 356K

Publishing Venue

Xerox Disclosure Journal

Abstract

In ionographic devices such as those described in U.S. Patent No. 4,463,363 to Gundlach et al., an ion producing device generates ions to be directed to an imaging surface. Figure 1 illustrates the structure of an ionographic print head, 1010, including ion chamber 1012 and coronode 1014 supported within the chamber. Coronode controller 1200 supplies high voltage pulses, on the order of several thousand volts D.C., to coronode 1014. Reference potential source 1018, connected to the wall of chamber 1012, maintains head 1010 at voltage Vref. The corona discharge at coronode 1014 creates a source of ions (preferably positive) which are attracted to the chamber wall held at VH. Inlet channel 1020 delivers pressurized air into the chamber from a suitable source, 1022. Air flows out of ion chamber 1012 to the exterior of head 1010 through modulation channei 1024. As the air passes through chamber 1012, it carries ions into modulation channel 1024, past modulation bar 2028. Ions allowed to pass out of head 1010, through modulation channel 1024, are directed to charge receptor 1034. Subsequently, the ions come under the influence of conductive plate 1030 and a backing layer, which charge receptor dielectric surface 1031, where plate 1030 is slidingly connected via shoe 1032 to a voltage supply.

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Page 1 of 6

XEROX DISCLOSURE JOURNAL

SYSTEM AND METHOD Proposed Classification EMPLOYING PULSES TO REDUCE
IMAGE ARTIFACTS
Frank C. Genovese

U.S. C1.346/159 Int. C1. GOlD 15/06

1033 1032 1030

FIG. I

XEROX DISCLOSURE JOURNAL - Vol. 17,Xo. 4 July/August 1992 215

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Page 2 of 6

SYSTEM AND METHOD EMPLOYING PULSES TO REDUCE IMAGE ARTIFACTS (Cont'd)

FIG. 2

216 XEROX DISCLOSURE JOURNAL - VOL 17, NO. 4 July/August 1992

[This page contains 1 picture or other non-text object]

Page 3 of 6

SYSTEM AND METHOD EMPLOYING PULSES TO REDUCE IMAGE ARTIFACTS (Cont'd)

FROM MOTION DETECTOR 121 0

FIG. 3

XEROX DISCLOSURE JOURNAL - Vol. 17, No. 4 July/August 1992 217

[This page contains 1 picture or other non-text object]

Page 4 of 6

SYSTEM AND METHOD EMPLOYING PULSES TO REDUCE IMAGE ARTIFACTS (Cont'd)

In ionographic devices such as those described in U.S. Patent No. 4,463,363 to Gundlach et al., an ion producing device generates ions to be directed to an imaging surface. Figure 1 illustrates the structure of an ionographic print head, 1010, including ion chamber 1012 and coronode 1014 supported within the chamber. Coronode controller 1200 supplies high voltage pulses, on the order of several thousand volts D.C., to coronode 1014. Reference potential source 1018, connected to the wall of chamber 1012, maintains head 1010 at voltage Vref. The corona discharge at coronode 1014 creates a source of ions (preferably positive) which are attracted to the chamber wall held at VH. Inlet channel 1020 delivers pressurized air into the chamber from a suitable source,
1022. Air flows out of ion chamber 1012 to the exterior of head 1010 through modulation channei 1024. As the air passes through chamber 1012, it carries ions into modulation channel 1024, past modulation bar 2028. Ions allowed to pass out of head 1010, through modulation channel 1024, are directed to charge receptor 1034. Subsequently, the ions come under the influence of conductive plate 1030 and a backing layer, which charge receptor dielectric surface 1031, where plate 1030 is slidingly connected via shoe 1032 to a voltage supply.

Motion detector 1210 detects when charge receptor dielectric surface 1031 moves an amount corresponding to a certain fraction of an image pixel and then sends a pulse to coronode controller 1200, as will be discussed in detail below. Motion detector 1210 can be a precision shaft encoder, of the optical or electromagnetic type, coupled to receptor dielectric surface 103 1. Once ions have been swept into modulation channel 1024 by the transport fluid, the ion- laden fluid stream is rendered intelligible. This rendering is accomplished by individually switching the electrodes of modulation bar 2028 in modulation channel 1024, between a blocking voltage source 1036 and a reference potential 1037 by means of a switch within controller 1100. Moreover, gray levels may be provided by supplying a continuously variable voltage signal to the modul...