Browse Prior Art Database

HIGH SECURITY COPYING PROCESS WITH PLYWOODING PHOTORECEPTOR

IP.com Disclosure Number: IPCOM000027348D
Original Publication Date: 1996-Apr-30
Included in the Prior Art Database: 2004-Apr-07
Document File: 2 page(s) / 46K

Publishing Venue

Xerox Disclosure Journal

Abstract

A defect of laser printers using coherent light, known as plywooding, is the appearance of interference artifacts in the photoreceptor for grey images. These patterns are specific to a particular photoreceptor and can be used to "fingerprint" or identify the photoreceptor that made a particular copy. By deliberately adjusting a copier to produce this plywood effect in a light grey background region, copiers in secure installations can produce uniquely identifiable copies, and allow auditing of copy generation or verification that copies were made on a particular "authorized" machine.

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XEROX DISCLOSURE JOURNAL

HIGH SECURITY COPYING Proposed Classification PROCESS WITH PLYWOODING U.S. C1.430/066 PHOTORECEPTOR Int. C1. G03g 15/04 Ronald E. Godlove
Huoy-Jen Yuh
John S. Chambers
Rachel Forgit
Robert E. McCumiskey
Kamran U. Zaman

A defect of laser printers using coherent light, known as plywooding, is the appearance of interference artifacts in the photoreceptor for grey images. These patterns are specific to a particular photoreceptor and can be used to "fingerprint" or identify the photoreceptor that made a particular copy. By deliberately adjusting a copier to produce this plywood effect in a light grey background region, copiers in secure installations can produce uniquely identifiable copies, and allow auditing of copy generation or verification that copies were made on a particular "authorized" machine.

REFERENCE

Xerox Disclosure Journal, Vol. 20, No. 2, MadApril 1995, pages 195-197.

XEROX DISCLOSURE JOURNAL - Vol. 21, No. 2 MarcWApril 1996 187

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188 XEROX DISCLOSURE JOURNAL - Vol. 21, No. 2 MarcMApril 1996

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