# US 2014/0197241 A1 · Covert coating for authentication of materials

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2014/0197241 A1
- Document ID: US20140197241A1
- Status: Published application
- Kind: A1
- Application number: 13/743,442
- Filed: 2013-01-17
- Published: 2014-07-17
- Earliest claimed: 2013-01-17
- Assignees: Spectra Systems Corporation
- Inventors: Nabil Lawandy
- Web page: https://patentgrep.com/patent/US20140197241A1

## CPC

- G06K 19/0614: {the marking being selective to wavelength, e.g. color barcode or barcodes only visible under UV or IR (methods or arrangements for sensing record carriers using a selected wavelength, see G06K7/12)}
- B42D 25/29: Securities; Bank notes
- B42D 25/378: Special inks
- G06K 19/06028: {using bar codes}
- G07D 7/1205: Testing spectral properties
- B42D 2035/34
- G06K: GRAPHICAL DATA READING (image or video recognition or understanding G06V); PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- B42D: BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
- G07D: HANDLING OF COINS OR VALUABLE PAPERS, e.g. TESTING, SORTING BY DENOMINATIONS, COUNTING, DISPENSING, CHANGING OR DEPOSITING

## Abstract

Systems and methods for document and product authentication are provided using a combination of interacting absorption and emission materials that are formed into covert optically encoded markings. The markings are formed from at least one emitter and at least one absorber, that exhibit a first emission in response to a first excitation of the emitter and a change in that emission in response to excitation of the absorber such that various combinations of emitter and absorber materials create a machine readable response that cannot be detected by the human eye.

## Claims

### Claim 1

A security feature for authenticating an article comprising:
at least one emitter material that generates an emission within an emission band in response to a first excitation; and
at least one absorber material that undergoes a change in absorption characteristics within at least a portion of said emission band in response to a second excitation,
wherein said change in said absorption characteristics causes a non-apparent change in said emission.

### Claim 2 (depends on 1)

The security feature of claim 1, further comprising:
said emitter and said absorber disposed within a coating on a substrate.

### Claim 3 (depends on 1)

The security feature of claim 1, further comprising:
said emitter material in a first coating on a substrate; and
said absorber material in a second coating on said substrate.

### Claim 4 (depends on 1)

The security feature of claim 1, wherein said non-apparent change is a machine detectible change in said emission of 5% or less.

### Claim 5 (depends on 1)

The security feature of claim 1, wherein said at least one emitter is selected from the group consisting of: fluorescent materials, phosphorescent materials, up-conversion materials and combinations thereof.

### Claim 6 (depends on 1)

The security feature of claim 1, wherein said at least one absorber is selected from the group consisting of: photochromic materials, thermochromic materials, electrochromic materials, magnetochromic materials, mechanochromic materials and combinations thereof.

### Claim 7 (depends on 1)

The security feature of claim 1, wherein said security feature is a planchette.

### Claim 8 (depends on 7)

The security feature of claim 7, wherein said planchette is incorporated into a substrate material.

### Claim 9 (depends on 1)

The security feature of claim 1, wherein said security feature is a security thread.

### Claim 10 (depends on 9)

The security feature of claim 9, wherein said security thread is incorporated into a substrate material.

### Claim 11 (depends on 1)

The security feature of claim 1, wherein said security feature is a fiber.

### Claim 12 (depends on 11)

The security feature of claim 11, wherein said fiber has a core containing said emitter material and a sheath surrounding said core containing said absorber material.

### Claim 13 (depends on 1)

The security feature of claim 1, wherein said security feature is an arrangement of materials on or in a substrate.

### Claim 14 (depends on 13)

The security feature of claim 13, wherein said arrangement is an arrangement of coating strips containing said emitter material on a substrate, a portion of said strips further including said absorber material.

### Claim 15 (depends on 14)

The security feature of claim 14, wherein said arrangement, when excited visually appears as a solid graphic, said absorbers creating a machine detectable pattern within the solid graphic.

### Claim 16 (depends on 15)

The security feature of claim 15, wherein said detectable pattern is a bar code.