Diffuse high reflectance film

• US 20050136200A1
• Filed: 12/19/2003
• Published: 06/23/2005
• Est. Priority Date: 12/19/2003
• Status: Abandoned Application

• Current Assignee: Sphereoptics Hoffman, LLC
• Original Assignee: Sphereoptics Hoffman, LLC
• Inventors: Bohme, Wolfgang, Durell, Christopher N.
• Application Number:
  US10/742,552
• Publication Number:
  US 20050136200A1
• Time in Patent Office: Days
• US Class Current: 428/35.700
• CPC Class Codes: B32B 2307/416 Reflective
• CPC Class Codes: B32B 2307/418 Refractive
• CPC Class Codes: B32B 2457/202 LCD, i.e. liquid crystal displays
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/322 comprising halogenated polyolefins, e.g. PTFE
• CPC Class Codes: B32B 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: G02B 5/021 the diffusion taking place at the element's surface, e.g. by means of surface roughening or microprismatic structures
• CPC Class Codes: G02B 5/0284 used in reflection
• CPC Class Codes: G02B 5/08 Mirrors vehicle mirrors involving special optical features B60R1/08
• CPC Class Codes: Y10T 428/1352 Polymer or resin containing [i.e., natural or synthetic]

Abstract

A diffuse reflective film including a bottom layer of reflective specular material and a top layer of polytetrafluoroethylene (PTFE) diffuser material for diffusely reflecting at least 96% of light in the portion of the electromagnetic spectrum between about 400 nanometers and about 2500 nanometers, and wherein the diffuse reflective film has a thickness of less than 1500 micrometers.

Claims

1. A diffuse reflective film including a bottom layer of reflective specular material and a top layer of polytetrafluoroethylene (PTFE) diffuser material for diffusely reflecting at least 96% of light within a portion of the electromagnetic spectrum between about 400 nanometers and about 2500 nanometers, and wherein the diffuse reflective film has a thickness of less than 1500 micrometers.

2. A diffuse reflective film according to claim 1, wherein the top layer of PTFE diffuser material comprises Zenith™

PTFE-based diffuse reflectance film.

3. A diffuse reflective film according to claim 1, wherein the bottom layer of reflective specular material comprises thermally induced phase separation (TPIS) layered polymer film.

4. A diffuse reflective film according to claim 1, wherein the top layer of PTFE diffuser material has a thickness of not more than 1000 micrometers.

5. A diffuse reflective film according to claim 1, wherein the bottom layer of reflective specular material has a thickness of not more than 500 micrometers.

6. A diffuse reflective film according to claim 1, wherein an adhesive layer is provided between the top layer of PTFE diffuser material and the bottom layer of reflective specular material.

7. A diffuse reflective film according to claim 1, wherein an adhesive layer is provided on a bottom surface of the bottom layer of reflective specular material.

8. A diffuse reflective film according to claim 1, wherein one of a top and bottom surface of the bottom layer of reflective specular material is more reflective and the top layer of PTFE diffuser material is placed on the more reflective surface.

9. A light conduit including a diffuse reflective film according to claim 1, and further comprising an outer shell and, wherein the diffuse reflective film covers at least a portion of an inner surface of the outer shell.

10. A light box including a diffuse reflective film according to claim 1, and further comprising an outer shell and, wherein the diffuse reflective film covers at least a portion of an inner surface of the outer shell.

11. A liquid crystal display including a diffuse reflective film according to claim 1, and further comprising a light guide directing light from a light source, wherein the diffuse reflective film covers at least a portion of an inner surface of the light guide.

12. A light emitting diode display including a diffuse reflective film according to claim 1, and further comprising a light guide directing light from a light source, wherein the diffuse reflective film covers at least a portion of an inner surface of the light guide.

13. An optical cavity including a diffuse reflective film according to claim 1, and further comprising a light guide directing light from a light source, wherein the diffuse reflective film covers at least a portion of an inner surface of the light guide.

14. A sign cabinet including a diffuse reflective film according to claim 1, and further comprising walls directing light from a light source, wherein the diffuse reflective film covers at least portions of inner surfaces of the walls.

23. A diffuse reflective film according to claim 1, wherein the bottom layer of reflective specular material comprises Vikuiti™

Enhanced Specular Reflector (ESR) layered polymer film.

24. A diffuse reflective film according to claim 1, wherein the bottom layer of reflective specular material comprises a metal film.

15. A method of forming a diffuse reflective film, comprising:

attaching a bottom layer of reflective specular material to a top layer of polytetrafluoroethylene (PTFE) diffuser material for diffusely reflecting at least 96% of light within the portion of the electromagnetic spectrum between about 400 and about 800 nanometers (nm); and

providing the diffuse reflective film with a thickness of less than 1500 micrometers.

16. A method according to claim 15, wherein the top layer of PTFE diffuser material comprises Zenith™

PTFE-based diffuse reflectance film.

17. A method according to claim 15, wherein the bottom layer of reflective specular material comprises thermally induced phase separation (TPIS) layered polymer film.

18. A method according to claim 15, wherein the top layer of PTFE diffuser material has a thickness of not more than 500 micrometers.

19. A method according to claim 15, wherein the bottom layer of reflective specular material has a thickness of not more than 500 micrometers.

20. A method according to claim 15, wherein an adhesive layer is provided between the top layer of PTFE diffuser material and the bottom layer of reflective specular material.

21. A method according to claim 15, wherein the bottom layer of reflective specular material comprises Vikuiti™

Enhanced Specular Reflector (ESR) layered polymer film.

22. A method according to claim 15, wherein the bottom layer of reflective specular material comprises a metal film.