Method of rendering a document or portion of it resistant to photocopying

• US 5,087,507 A
• Filed: 11/08/1988
• Issued: 02/11/1992
• Est. Priority Date: 11/20/1987
• Status: Expired due to Fees

• Current Assignee: Lipatec Etablissement
• Original Assignee: Lipatec Etablissement
• Inventors: Heinzer, Paul
• Primary Examiner(s): Gallagher, John J.
• Application Number:
  US07/268,754
• Time in Patent Office: 1,190 Days
• Field of Search: 156/277, 427/7, 427/261, 428/916, 428/195, 428/203, 283/109, 283/902, 283/114, 430/10, 355/201
• US Class Current: 428/195.1
• CPC Class Codes: B41M 3/144 using fluorescent, luminescent or iridescent effects
• CPC Class Codes: B42D 25/29 Securities; Bank notes
• CPC Class Codes: B42D 25/36 comprising special materials
• CPC Class Codes: B42D 25/378 Special inks
• CPC Class Codes: B42D 25/45 Associating two or more layers
• CPC Class Codes: B42D 25/47 using adhesives
• CPC Class Codes: G03C 5/08 Photoprinting G03C5/18 takes precedence; Processes and means for preventing photoprinting
• CPC Class Codes: G03G 21/043 by using an original which is not reproducible or only reproducible with a different appearence, e.g. originals with a photochromic layer or a colour background
• CPC Class Codes: Y10S 283/902 Anti-photocopy
• CPC Class Codes: Y10S 428/916 Fraud or tamper detecting
• CPC Class Codes: Y10T 428/24802 Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
• CPC Class Codes: Y10T 428/24868 Translucent outer layer

Abstract

An article with at least a portion carrying symbols representing information to be protected against photocopying is formed by a carrier, a continuous layer covering the portion of the carrier and forming a background thereon, and a mainly discontinuous layer applied on the continuous layer and forming the symbols against the background. One of the layers is an iridescent layer of a color that copies dark and the other of the layers has a dark color. Thus photocopying gives an image without distinction between the symbols and the background.

Claims

1. A method of preparing a document consisting of a sheet at least a portion of which carries alphanumeric or graphical information and resistant to photocopying, the method comprising the steps of:

applying a continuous layer of a color that copies black directly to the portion of the sheet;

applying to the portion of the sheet directly over the layer of color that copies black a continuous layer of an iridescent substance; and

applying to the sheet directly over the iridescent-substance layer a layer forming the information against the continuous layer and having a dark color that also copies black, whereby photocopying gives a black copy without information.

2. An article with at least a portion carrying information to be protected against photocopying, the article consisting essentially of:

a sheet;

a continuous layer of a color that copies black directly covering the portion of the sheet;

a continuous layer covering the portion of the sheet directly over the layer of the color that copies black and constituted as an iridescent layer; and

a layer applied directly on the continuous iridescent layer, forming the information against the continuous layer, and having a dark color that also copies black, whereby photocopying gives a black copy without information.