Optical diffuser with IR and/or UV blocking coating

• US 20070064446A1
• Filed: 01/06/2006
• Published: 03/22/2007
• Est. Priority Date: 09/20/2005
• Status: Active Grant

• Current Assignee: Guardian Glass LLC (KOCH Industries Incorporated)
• Original Assignee: Guardian Industries Corporation (KOCH Industries Incorporated)
• Inventors: Taylor, Thomas, Varaprasad, Desaraju, Sharma, Pramod
• Granted Patent: US 7,771,103 B2
• Time in Patent Office: Days
• US Class Current: 362/618
• CPC Class Codes: C03C 17/04 by fritting glass powder
• CPC Class Codes: C03C 17/3411 with at least two coatings of inorganic materials C03C17/36, C03C17/42 take precedence
• CPC Class Codes: C03C 17/3417 all coatings being oxide coatings
• CPC Class Codes: C03C 2217/452 Glass
• CPC Class Codes: C03C 2217/475 Inorganic materials
• CPC Class Codes: C03C 2217/74 UV-absorbing coatings
• CPC Class Codes: C03C 2218/365 Coating different sides of a glass substrate
• CPC Class Codes: C03C 8/14 Glass frit mixtures having non-frit additions, e.g. opacifiers, colorants, mill-additions
• CPC Class Codes: G02B 1/10 Optical coatings produced by application to, or surface treatment of, optical elements G02B1/08 takes precedence
• 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 5/0221 the surface having an irregular structure G02B5/0226 takes precedence
• CPC Class Codes: G02B 5/0242 by means of dispersed particles
• CPC Class Codes: G02B 5/0278 used in transmission
• CPC Class Codes: G02B 5/0294 adapted to provide an additional optical effect, e.g. anti-reflection or filter
• CPC Class Codes: G02B 5/0891 Ultraviolet [UV] mirrors apparatus for microlithography exposure G03F7/70; X-ray multilayer structures G21K1/06
• CPC Class Codes: G02B 5/208 for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation
• CPC Class Codes: G02B 5/22 Absorbing filters G02B5/201 - G02B5/208 take precedence
• CPC Class Codes: G02F 1/133606 including a specially adapted diffusing, scattering or light controlling members
• CPC Class Codes: G02F 2201/083 infrared absorbing
• CPC Class Codes: G02F 2201/086 UV absorbing

Abstract

A diffuser is provided in an illumination system, where the diffuser is capable of blocking significant amounts of infrared (IR) and/or ultraviolet (UV) radiation. In certain example embodiments of this invention, the diffuser includes a glass substrate which supports an IR/UV coating(s) that blocks significant amounts of IR and/or UV radiation thereby reducing the amount of IR and/or UV radiation which can makes its way through the diffuser. In certain example embodiments, the coating may include particulate in a frit matrix so that the coating may both diffuse visible light and perform IR and/or UV blocking.

Claims

1. An illumination system comprising:

a light source for emitting light, the light emitted from the light source including at least visible light as well as infrared (IR) and/or ultraviolet (UV) radiation;

a diffuser positioned so as to receive light from the light source, the diffuser diffusing visible light received from the light source; and

wherein the diffuser comprises a glass substrate that supports an IR blocking coating, so that the diffuser has a transmission at a wavelength of about 2300 nm of no greater than about 45%.

2. The illumination system of claim 1, wherein the IR blocking coating comprises an IR blocking material in a glass frit.

3. The illumination system of claim 1, wherein the IR blocking material comprises zinc antimonate.

4. The illumination system of claim 1, wherein the IR blocking coating also blocks significant amounts of UV radiation, so that the diffuser has a T_UV (UV transmission) of no greater than about 20%.

5. The illumination system of claim 2, wherein the coating further comprises inorganic oxide(s) of one or more of Ce, Bi, Ti, Sn and/or Sb in the glass frit, for blocking at least some UV radiation.

6. The illumination system of claim 5, wherein the coating comprises, by weight, from about 0.1 to 15% of the inorganic oxide(s) of one or more of Ce, Bi, Ti, Sn and/or Sb.

7. The illumination system of claim 6, wherein the coating comprises, by weight, from about 0.1 to 10% of the inorganic oxide(s) of one or more of Ce, Bi, Ti, Sn and/or Sb.

8. The illumination system of claim 1, wherein the coating comprises, by weight, from about 5 to 50% zinc antimonate, more preferably from about 5 to 40%, and most preferably from about 10 to 35%.

9. The illumination system of claim 1, wherein the coating comprises, by weight, at least about 50% frit, more preferably at least about 60%, even more preferably at least about 70%.

10. The illumination system of claim 1, wherein the diffuser has a transmission at a wavelength of about 2300 nm of no greater than about 30%.

11. The illumination system of claim 1, wherein the diffuser has a transmission at a wavelength of about 2300 nm of no greater than about 20%.

12. The illumination system of claim 1, wherein the diffuser has a T_UV of no greater than about 10%.

13. The illumination system of claim 1, wherein the IR blocking coating is in direct contact with the glass substrate.

14. The illumination system of claim 1, wherein the glass substrate is thermally tempered.

15. The illumination system of claim 1, wherein the coating comprises a low-E coating for blocking IR radiation and at least one layer comprising frit located on the glass substrate over at least the low-E coating.

16. The illumination system of claim 1, wherein the coating comprises a layer comprising tin oxide and a layer comprising frit located over at least the layer comprising tin oxide.

17. The illumination system of claim 1, wherein the diffuser has a transmission at 325 nm of less than 15%, more preferably less than 10%, and most preferably less than 5%.

18. The illumination system of claim 1, wherein the diffuser has a visible transmission of at least about 35%, more preferably at least about 50%, and even more preferably at least about 60%.

19. An optical diffuser for use in an illumination system, the optical diffuser comprising:

a glass substrate that supports an IR and/or UV blocking coating,

wherein the diffuser is characterized by one or both of;

(a) a T_UV (UV transmission) of no greater than about 20%, and wherein the UV blocking coating comprises at least one inorganic metal oxide for blocking significant amounts of UV radiation, and wherein the at least one inorganic metal oxide is provided in a frit; and

/or

(b) a transmission at a wavelength of about 2300 nm of no greater than about 45%.

20. The diffuser of claim 19, wherein the diffuser has both (a) and (b).

21. The diffuser of claim 19, wherein the diffuser has (b), and wherein the diffuser has a transmission at a wavelength of about 2300 nm of no greater than about 30%.

22. The diffuser of claim 19, wherein the coating is at least an IR blocking coating and comprises zinc antimonate.