Systems, compositions, and methods for full color laser engraving of ID documents

• US 20030234292A1
• Filed: 12/24/2002
• Published: 12/25/2003
• Est. Priority Date: 12/24/2001
• Status: Active Grant

• Current Assignee: L-1 Secure Credentialing, LLC (Advent International Corporation)
• Original Assignee: L-1 Secure Credentialing, LLC (Advent International Corporation)
• Inventors: Jones, Robert
• Granted Patent: US 7,793,846 B2
• Time in Patent Office: Days
• US Class Current: 235/491
• CPC Class Codes: B41M 3/14 Security printing securities B42D25/29
• CPC Class Codes: B41M 3/142 using chemical colour-formers or chemical reactions, e.g. leuco-dye/acid, photochromes
• CPC Class Codes: B41M 5/286 using compounds undergoing unimolecular fragmentation to obtain colour shift, e.g. bleachable dyes
• CPC Class Codes: B41M 5/323 Organic colour formers, e.g. leuco dyes
• CPC Class Codes: B41M 5/34 Multicolour thermography
• CPC Class Codes: B41M 5/46 characterised by the light-to-heat converting means; characterised by the heat or radiation filtering or absorbing means or layers
• CPC Class Codes: B42D 25/00 Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof printing processes to produce identification or security features B41M3/14
• CPC Class Codes: B42D 25/23 Identity cards
• CPC Class Codes: B42D 25/382 absorbing or reflecting infrared light
• CPC Class Codes: B42D 25/387 absorbing or reflecting ultraviolet light
• CPC Class Codes: B42D 25/41 using electromagnetic radiation B42D25/435 takes precedence
• CPC Class Codes: B42D 25/435 using electromagnetic radiation, e.g. laser
• CPC Class Codes: G06K 1/126 by photographic or thermographic registration recording apparatus for measuring instruments G01D15/00

Abstract

In one embodiment, the invention provides a method for forming a full color laser engraved image on an ID card. As described below, a special image capable layer is prepared that is addressable by one or more near infrared (NIR) lasers. Each type of particle contained within the image capable layer is associated with a particular color (e.g., cyan, magenta, or yellow) and is responsive (i.e., can selectively absorb) a particular wavelength of laser energy to form a laser engraved pixel in that respective color. In one embodiment, the particles are selected such that the wavelengths that they respond to do not overlap significantly. By providing discrete physical particles and preventing a given particle from responding to more than one laser wavelength, it can be possible to minimize so-called “cross talk” between the cyan, magenta, and yellow centers and minimize contamination and/or chemical mixing of image formers. This helps to ensure image accuracy and quality.

Claims

1. A method of producing an identification document comprising the steps of:

providing at least a first color dye in a document layer, the first color dye experiencing a transformation upon excitation;

providing at least a first sensitive dye in proximity of the first color dye;

exciting the first sensitive dye with a laser to excite the first color dye.

2. The method of claim 1, wherein the exciting step causes the first sensitive dye to release heat.

3. The method of claim 2, wherein the released heat excites the first color dye so as to experience a transformation.

4. The method of claim 3, wherein the transformation is a unimolecular transformation to a colored state.

5. The method of claim 4, wherein the laser comprises at least one of an infrared laser, a near infrared laser and a ultra-violet light laser.

6. An identification document comprising

a core adhesively bound to,

an imaging layer comprising a mixture including a first color dye, the first color dye experiencing a transformation upon excitation, and a first sensitive dye, wherein exciting the first sensitive dye with a laser excites the first color dye.

7. The document of claim 6, wherein exciting the first color dye causes the first color dye transform to a colored state.