Specular reflector and LED lamps using same
View Patent ↗A specular reflector and LED lamps using embodiments of the reflector are disclosed. Embodiments of the invention provide a reflector for solid state lamps. The reflector can be a specular reflector. The reflector includes a rigid, polymeric substrate and sputtered metal applied to the substrate. In some embodiments, the metal is silver. In some embodiments, the metal is applied without an intervening base coat. In some embodiments, the substrate is made from or includes an aromatic polyester such as polyarylate. The reflector can include a discontinuous or irregular surface yet still exhibit very high overall reflectivity and efficiency because the metal can be applied without an intervening base coat. In some embodiments, the reflector is used in lamps having a retroreflective optical design.
1. A reflector shaped to receive light from at least one LED, the reflector comprising:
a rigid, polymeric substrate with a plurality of adjoining panels joined together around the reflector to form a discontinuous surface shaped so that the at least one LED is to be positioned at an open end of the reflector to shine into the reflector; and
sputtered metal applied to the substrate without an intervening base coat to maintain a reflectivity of at least 90% across creases formed between the adjoining panels.
2. The reflector of claim 1 wherein the substrate comprises aromatic polyester.
3. The reflector of claim 2 wherein the aromatic polyester is polyarylate.
4. The reflector of claim 3 wherein the substrate includes a discontinuous surface and the sputtered metal replicates the discontinuous surface and imparts a surface reflectivity of at least 95% to the reflector.
5. The reflector of claim 4 wherein the sputtered metal comprises silver.
6. The reflector of claim 1 wherein the substrate comprises at least one of a thermoset and polyetherimide.
7. The reflector of claim 6 wherein the substrate includes a discontinuous surface and the sputtered metal replicates the discontinuous surface and imparts a surface reflectivity of at least 95% to the reflector.
8. The reflector of claim 7 wherein the sputtered metal comprises silver.
9. An LED lamp comprising:
at least one LED to produce light;
a power supply electrically connected to the at least one LED; and
a high reflectivity specular retroreflector disposed to receive at least some of the light from the at least one LED, with the at least one LED positioned at an open end of the high-reflectivity specular retroreflector to shine into the high-reflectivity specular retroreflector, the high reflectivity specular retroreflector further comprising a rigid, polymeric substrate with a plurality of adjoining panels joined together around the reflector to form a discontinuous surface and sputtered metal applied to the substrate without an intervening base coat to maintain a reflectivity of at least 90% across creases formed between the adjoining panels.
10. The LED lamp of claim 9 wherein the substrate comprises aromatic polyester, and wherein the sputtered metal is applied to the substrate without an intervening base coat.
11. The LED lamp of claim 10 wherein the aromatic polyester is polyarylate.
12. The LED lamp of claim 11 wherein the substrate includes a discontinuous surface and the sputtered metal replicates the discontinuous surface.
13. The LED lamp of claim 12 wherein the sputtered metal further comprises silver.
14. The LED lamp of claim 13 wherein the average surface reflectivity of the retroreflector is at least 94%.
15. The LED lamp of claim 14 wherein the average surface reflectivity of the retroreflector is at least 95%.
16. The LED lamp of claim 10 wherein the substrate comprises at least one of a thermoset and polyetherimide.
17. The LED lamp of claim 16 wherein the substrate includes a discontinuous surface and the sputtered metal replicates the discontinuous surface so that the average surface reflectivity of the retroreflector is at least 94%.
18. The LED lamp of claim 17 wherein the sputtered metal comprises silver.
19. A method of making a lamp comprising:
providing a rigid, polymeric substrate having a plurality of adjoining panels joined together around the reflector to form a discontinuous surface;
sputtering metal onto the substrate without an intervening base coat so that the metal substantially replicates the discontinuous surface to maintain a reflectivity of at least 90% across creases formed between the adjoining panels to produce a specular reflector;
positioning at least one LED at an open end of the specular reflector so that the at least one LED shines into the specular reflector, which in turn reflects at least a portion of light emitted by the at least one LED; and
connecting a power supply to the at least one LED.
20. The method of claim 19 wherein the sputtering of the metal imparts a surface reflectivity of at least 95% to the specular reflector.
21. The method of claim 20 wherein the metal comprises silver.
22. The method of claim 21 wherein the polymeric substrate comprises polyarylate.
23. The method of claim 21 wherein the polymeric substrate comprises at least one of a thermoset and polyetherimide.
24. The method of claim 19 wherein the sputtering of the metal imparts a surface reflectivity of at least 95% to the specular reflector.
25. The method of claim 24 wherein the metal comprises silver.
26. The method of claim 25 wherein the polymeric substrate comprises polyarylate.
27. The method of claim 25 wherein the polymeric substrate comprises at least one of a thermoset and polyetherimide.
28. A retroreflector shaped to receive light from at least one LED, the retroreflector comprising:
a rigid, polymeric substrate having a plurality of adjoining panels joined together around the reflector to form a discontinuous surface shaped so that the at least one LED is to be positioned at an open end of the retroreflector to shine into the retroreflector; and
sputtered silver applied to the substrate without an intervening base coat to maintain a reflectivity of at least 90% across creases formed between the adjoining panels.
29. The retroreflector of claim 28 wherein the average surface reflectivity of the retroreflector is at least 94%.
30. The retroreflector of claim 29 wherein the average surface reflectivity of the retroreflector is at least 95%.
31. The retroreflector of claim 29 wherein the substrate comprises at least one of thermoset, polyetherimide, aromatic polyester, polycarbonate, ABS and ABS/polycarbonate.
32. The retroreflector of claim 27 wherein the silver is applied without an intervening base coat.
33. The retroreflector of claim 32 wherein the substrate comprises aromatic polyester.
34. The retroreflector of claim 32 wherein the substrate comprises at least one of polyarylate, thermoset and polyetherimide.