HEATABLE LENS FOR LUMINAIRES, AND/OR METHODS OF MAKING THE SAME

• US 20120250314A1
• Filed: 04/02/2012
• Published: 10/04/2012
• Est. Priority Date: 02/26/2010
• Status: Active Grant

• Current Assignee: Guardian Glass LLC (KOCH Industries Incorporated)
• Original Assignee: Guardian Industries Corporation (KOCH Industries Incorporated)
• Inventors: Maikowski, David P., McClean, David D., Bourque, Timothy, Hobbs, Christopher
• Granted Patent: US 8,939,606 B2
• Time in Patent Office: Days
• US Class Current: 362/235
• CPC Class Codes: B32B 17/10036 comprising two outer glass sheets
• CPC Class Codes: B32B 17/10201 Dielectric coatings
• CPC Class Codes: B32B 17/10211 Doped dielectric layer, electrically conductive, e.g. SnO2:F
• CPC Class Codes: B32B 17/10541 comprising a light source or a light guide
• CPC Class Codes: B32B 17/10761 containing vinyl acetal
• CPC Class Codes: B32B 17/10788 containing ethylene vinylacetate
• CPC Class Codes: C03C 17/2456 Coating containing TiO2
• CPC Class Codes: C03C 17/3435 comprising a nitride, oxynitride, boronitride or carbonitride
• CPC Class Codes: C03C 17/3482 comprising silicon, hydrogenated silicon or a silicide
• CPC Class Codes: C03C 2217/70 Properties of coatings
• CPC Class Codes: C03C 2217/948 Layers comprising indium tin oxide [ITO]
• CPC Class Codes: C03C 2218/154 by sputtering
• CPC Class Codes: C03C 2218/32 After-treatment
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: F21Y 2115/15 Organic light-emitting diodes [OLED]
• CPC Class Codes: H05B 2203/01 Heaters comprising a particular structure with multiple layers
• CPC Class Codes: H05B 2203/013 Heaters using resistive films or coatings
• CPC Class Codes: H05B 3/84 Heating arrangements specially adapted for transparent or reflecting areas, e.g. for demisting or de-icing windows, mirrors or vehicle windshields

Abstract

Certain example embodiments of this invention relate to heatable glass substrates that may be used in connection with lighting applications, and/or methods of making the same. In certain example embodiments, a glass substrate supports an antireflective (AR) coating on a first major surface thereof, and a conductive coating on a second, opposite major surface thereof. Bus bars connect the conductive coating to a power source in certain example embodiments. The substrate may be heat treated (e.g., heat strengthened and/or thermally tempered), with one or both coatings thereon. The heatable glass substrate thus may help provide a chemical and/or environmental barrier for the luminaire or lighting system disposed behind it. In addition, or in the alternative, the heatable glass substrate may help reduce the amount of moisture (e.g., snow, rain, ice, fog, etc.) that otherwise could accumulate on the luminaire or lighting system.

Claims

1. A lens for a lighting system, comprising:

a glass substrate supporting antireflective and transparent coatings on first and second major surfaces thereof, respectively; and

at least one bus bar in electrical communication with the conductive coating, the at least one bus bar being configured to convey voltage to the conductive coating from an external power source to, in turn, cause the conductive coating to heat up,

wherein the antireflective and transparent coatings are sputtered coatings, and

wherein the substrate is heat treated together with the antireflective and transparent coatings thereon.

2. The lens of claim 1, wherein the antireflective coating comprises, in order moving away from the substrate:

a layer comprising silicon oxynitride;

a layer comprising titanium oxide; and

a layer comprising silicon oxide.

3. The lens of claim 1, wherein the antireflective coating provides a visible transmission increase of 4% points, compared to a situation where no antireflective coating is provided.

4. The lens of claim 1, wherein post heat treatment, the lens has a visible transmission of at least 87%.

5. The lens of claim 1, wherein the conductive coating comprises, in order moving away from the substrate, a layer comprising a transparent conductive oxide (TCO), and a silicon-inclusive overcoat.

6. The lens of claim 1, wherein the antireflective coating comprises, in order moving away from the substrate, high and low refractive index layers.

7. The lens of claim 1, wherein the conductive coating comprises a layer comprising a transparent conductive oxide (TCO) sandwiched between first and second layers comprising silicon oxynitride.

8. The lens of claim 7, wherein the TCO is indium tin oxide.

9. The lens of claim 7, wherein the layer comprising the TCO has an index of refraction of 1.7-2.1 at 550 nm.

10. The lens of claim 9, wherein the layer comprising the TCO has a sheet resistance of 10-30 ohms/square and a physical thickness of 100-170 nm.

11. The lens of claim 9, wherein the first and second layers comprising silicon oxynitride each have refractive indexes of 1.45-2.10 at 550 nm, and an extinction coefficient k of <

0.01 at 550 nm.

12. The lens of claim 11, wherein the physical thicknesses of the first and second layers comprising silicon oxynitride are 55-125 nm.

13. The lens of claim 11, wherein the first and second layers comprising silicon oxynitride each have refractive indexes of 1.7+/−

0.2 at 550 nm, and wherein the layer comprising the TCO has a refractive index of 1.9+/−

0.1 at 550 nm.

14. The lens of claim 1, wherein the heat treatment is thermal tempering.

15. A lighting system, comprising:

one or more solid state lights;

the lens of claim 1, interposed between the one or more solid state lights and a viewer of the lighting system; and

a power source operable to drive the conductive coating of the lens at a power density of 1-6 W/in².

16. The lighting system of claim 15, wherein the one or more solid state lights comprise an array of organic and/or inorganic light emitting diodes.

17. The lighting system of claim 15, wherein the lens is spaced apart from the one or more solid state lights.

18. A lighting system, comprising:

one or more solid state lights; and

a lens spaced apart from the one or more solid state lights, the lens comprising;

a first glass substrate supporting a sputter-deposited antireflective coating on a major surface thereof; and

a second glass substrate supporting a sputter-deposited conductive coating on a major surface thereof, the first and second substrates being laminated to one another such that coated surfaces thereof face away from one another;

wherein the first substrate with the antireflective coating thereon and/or the second with the conductive coating thereon is/are heat treated.

19. A method of making a heatable lens for a lighting system, the method comprising:

sputtering depositing a multilayer antireflective coating on a first major surface of a glass substrate;

sputtering depositing a multilayer conductive coating on a second major surface of the glass substrate, the first and second major surfaces being opposite one another;

heat treating the glass substrate with the multilayer antireflective and conductive coatings thereon; and

disposing at least one bus bar on the glass substrate such that the at least one bus bar is in electrical communication with the conductive coating so as to heat the substrate when voltage is provided from an external power source.

20. The method of claim 19, wherein the antireflective coating comprises, in order moving away from the substrate:

a layer comprising silicon oxynitride;

a layer comprising titanium oxide; and

a layer comprising silicon oxide.

21. The method of claim 20, wherein the conductive coating comprises a layer comprising a transparent conductive oxide (TCO) sandwiched between first and second layers comprising silicon oxynitride.

22. The method of claim 21, wherein the layer comprising the TCO has a sheet resistance of 10-30 ohms/square and a physical thickness of 100-170 nm.

23. The method of claim 22, wherein the physical thicknesses of the first and second layers comprising silicon oxynitride are 55-125 nm.

24. The method of claim 21, wherein the first and second layers comprising silicon oxynitride each have refractive indexes of 1.7+/−

0.2 at 550 nm and an extinction coefficient k of <

0.01 at 550 nm, and wherein the layer comprising the TCO has a refractive index of 1.9+/−

0.1 at 550 nm.

25. The method of claim 19, wherein the heat treatment is thermal tempering.

26. A method of making a lighting system, the method comprising:

making a lens in accordance with the method of claim 19;

providing a solid state light source;

providing the lens in spaced apart relation to the light source; and

connecting the at least one bus bar of the lens to an external power source.