Photoluminescent markings with functional overlayers

• US 8,097,843 B2
• Filed: 05/06/2011
• Issued: 01/17/2012
• Est. Priority Date: 06/18/2009
• Status: Active Grant

• Current Assignee: Performance Indicator, LLC
• Original Assignee: Performance Indicator, LLC
• Inventors: Agrawal, Satish, Kingsley, Edward
• Primary Examiner(s): Kim, Kiho
• Application Number:
  US13/102,100
• Publication Number:
  US 20110260045A1
• Time in Patent Office: 256 Days
• Field of Search: 250/271, 250/461.1, 250/462.1, 250/473.1, 2504842-4845, 235/491, 235/439, 427/7
• US Class Current: 250/271
• CPC Class Codes: B41M 3/144 using fluorescent, luminescent or iridescent effects
• CPC Class Codes: B42D 25/378 Special inks
• CPC Class Codes: B42D 25/382 absorbing or reflecting infrared light
• CPC Class Codes: G06K 19/14 the marking being sensed by radiation
• CPC Class Codes: G06K 2019/06225 using wavelength selection, e.g. colour code
• CPC Class Codes: G07D 7/005 Testing security markings invisible to the naked eye, e.g. verifying thickened lines or unobtrusive markings or alterations
• CPC Class Codes: G07D 7/1205 Testing spectral properties

Abstract

A photoluminescent marking that includes at least one functional overlayer is disclosed. The overlayer generally provides for at least one of selective filtration, reflection and absorption of wavelengths that may cause photolytic degradation of underlying photoluminescent materials. A method of fabrication is provided.

Claims

1. A photoluminescent marking comprising:

a photoluminescent layer comprising at least one type of photoluminescent material and,

at least one functional overlayer disposed over the layer, the overlayer being adapted to selectively filter wavelengths of radiation that cause photolytic degradation of the photoluminescent material.

2. The marking as in claim 1, wherein the overlayer is substantially transmissive of wavelengths that at least one of excite the photoluminescent material and are emitted from the photoluminescent material.

3. The marking as in claim 1, wherein the overlayer comprises at least one colorant to provide the filter.

4. The marking as in claim 3, wherein the colorant comprises absorptive materials.

5. The marking as in claim 1, wherein the overlayer comprises reflective materials to selectively filter the wavelengths of radiation.

6. The marking as in claim 1, further comprising a reflective layer disposed below the photoluminescent layer.

7. The marking as in claim 1, wherein the selectively reflective materials are substantially transmissive of selected wavelengths.

8. The marking as in claim 7, wherein the selected wavelengths comprise at least one of visible wavelengths and infrared wavelengths of electromagnetic radiation.

9. The marking as in claim 1, wherein the photoluminescent layer comprises at least one of a phosphorescent material and a fluorescent material.

10. The marking as in claim 1, wherein the functional overlayer is further adapted to provide a stealth marking.

11. A photoluminescent marking comprising:

a photoluminescent layer comprising at least one type of photoluminescent material and,

at least one functional overlayer disposed over the layer, the overlayer being adapted to selectively filter wavelengths of radiation to enhance the daylight observability of the marking.

12. The marking as in claim 11, wherein the overlayer comprises selectively reflective materials adapted to reflect selected emissions from the photoluminescent materials back into the photoluminescent layer.

13. A method of fabricating a marking, the method comprising:

incorporating at least one type of photoluminescent material into a layer; and

applying a functional overlayer to the layer, wherein the overlayer is adapted to selectively filter wavelengths of radiation that cause photolytic degradation of the photoluminescent material.

14. The method as in claim 13, wherein the type of photoluminescent material is one of a phosphorescent material and a fluorescent material.

15. The method as in claim 13, incorporating comprises mixing the material into a combination of a binder resin, a liquid carrier, a dispersing agent, a rheology modifying agent, a photostabilizer, a de-aerating agent, and a wetting agent.

16. The method as in claim 13, wherein the overlayer is adapted by incorporation of at least one of an absorptive material and a fluorescent material.

17. The method as in claim 13, further comprising incorporating at least one reflective layer in the marking.

18. A photoluminescent marking comprising:

a photoluminescent layer comprising selected photoluminescent materials and,

at least one functional overlayer disposed over the photoluminescent layer, wherein the marking emits wavelengths in the visible region of the electromagnetic spectrum and wherein the functional overlayer comprises at least one of;

(i) selected colorant materials that adjust the daylight color of the marking to render it a stealth marking by either blending imperceptibly with the surrounding area of an object to which the marking is applied, or, when applied to objects that typically have non-photoluminescent markings for traditional usage, renders a daylight color indicative of such traditional markings, and

(ii) selected colorant materials that increase the photolytic stability of the marking, and

(iii) selected fluorescent materials that enhance the daylight observability of the infrared emission, and

(iv) selected colorants to prevent the observability with the naked eye of a printed message that is printed on the photoluminescent layer or any of the functional overlayers (ii) or (iii) above.