Laser printing method and substrate

• US 6,140,267 A
• Filed: 05/24/1999
• Issued: 10/31/2000
• Est. Priority Date: 09/12/1997
• Status: Expired due to Fees

• Current Assignee: Nocopi Technologies, Inc.
• Original Assignee: Nocopi Technologies, Inc.
• Inventors: Gundjian, Arshavir
• Primary Examiner(s): Hess, Bruce H.
• Application Number:
  US09/317,315
• Time in Patent Office: 526 Days
• Field of Search: 427/150-152, 430/945, 503/201, 503/204, 503/226
• US Class Current: 503/201
• CPC Class Codes: B41M 3/144 using fluorescent, luminescent or iridescent effects
• CPC Class Codes: B41M 5/267 Marking of plastic artifacts, e.g. with laser
• CPC Class Codes: B41M 5/30 using chemical colour formers B41M5/34 takes precedence
• CPC Class Codes: B41M 5/34 Multicolour thermography
• CPC Class Codes: Y10S 430/146 Laser beam

Abstract

A method and substrate for printing information wherein at least one coating is applied to a substrate, the coating having a colorformer leucodye and at least one color activator. The colorformer leucodye and at least one activator react when heated to exhibit a chromic change of at least one of a color change visible in normal light and a fluorescence visible only in ultraviolet light. The at least one coating is heated with at least one laser beam to effect the chromic change at selected points to thereby print information.

Claims

1. A method for printing information on a substrate comprising the steps of:

applying at least one layer to a substrate comprising a colorformer leucodye and a color activator, wherein the colorformer leucodye and the activator react when heated to exhibit a chromic change of a color change visible in normal light and a fluorescence visible only in ultraviolet light; and

heating the at least one layer with at least one laser beam to effect the chromic change at selected points to thereby print information.

2. The method according to claim 1, wherein the step of heating comprises using a CO₂ 10.6 μ

wavelength or a YAG 1.06 μ

wavelength laser.

3. The method according to claim 1, wherein the heating is to a temperature above about 60°

C. to below about 100°

C.

4. The method according to claim 1, wherein the activator and at least one colorformer leucodye are in a micronized form.