Steven C Tuttle

US Patent:

52912434, Mar 1, 1994

Filed:

Feb 5, 1993

Appl. No.:

8/014474

Inventors:

Dean A. Heckman - Palmyra NY
Steven R. Tuttle - Rochester NY
Irshad H. Qureshi - Fairport NY

Assignee:

Xerox Corporation - Stamford CT

International Classification:

G03G 2100
G09C 500

US Classification:

355201

Abstract:

A system for printing security documents which have copy detection or tamper resistance in plural colors with a single pass electronic printer printing an integrated image controlled by an image generation system which electronically generates a safety background image pattern with first and second interposed color patterns which is electronically merged with alphanumeric information and a protected signature into an integrated electronic image for the printer. The single pass printer preferably has an imaging surface upon which two latent images thereof are interposed, developed with two differently colored developer materials, and simultaneously transferred to the substrate in a single pass. The color patterns are preferably oppositely varying density patterns of electronically generated pixel dot images with varying spaces therebetween. Preferably a portion of the alphanumeric information is formed by a special secure font, such as a low density shadow copy.