LED LIGHTING ASSEMBLY

• US 20100051976A1
• Filed: 11/15/2007
• Published: 03/04/2010
• Est. Priority Date: 11/15/2006
• Status: Abandoned Application

• Current Assignee: Lemnis Lighting Patent Holding B.V.
• Original Assignee: Lemnis Lighting Patent Holding B.V.
• Inventors: Rooymans, Johannes Otto
• Application Number:
  US12/515,025
• Publication Number:
  US 20100051976A1
• Time in Patent Office: Days
• US Class Current: 257/89
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• CPC Class Codes: F21V 19/001 the light sources being semiconductors devices, e.g. LEDs
• CPC Class Codes: F21V 23/0442 activated by means of a sensor, e.g. motion or photodetectors
• CPC Class Codes: F21V 29/70 characterised by passive heat-dissipating elements, e.g. heat-sinks
• CPC Class Codes: F21V 29/85 characterised by the material liquid coolants F21V29/56
• CPC Class Codes: F21Y 2113/13 comprising an assembly of point-like light sources
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 33/641 characterized by the materials
• CPC Class Codes: H05B 45/40 Details of LED load circuits

Abstract

Disclosed is a lighting assembly comprising one or more light emitting diodes (LEDs). The assembly comprises a ceramic disc which is coated with a layer of heat conducting material. The assembly provides sufficient galvanic insulation for it to be used safely even when connected to the electric grid as a power source.

Claims

1. A LED-based lighting assembly comprising:

a) a disc of ceramic material having a mounting surface and an attachment surface;

b) a layer of an electric and heat conducting material covering at least part of the mounting surface of the disc;

c) at least one LED mounted on the mounting surface of the disc, said LED being in heat-conductive contact with the electric and heat conducting material.

2. The lighting assembly of claim 1 wherein the electric and heat conducting material is a metal.

3. The lighting assembly of claim 1 wherein the disc has a thickness in the range of 200 to 500 micrometers.

4. The lighting assembly of claim 3 wherein the layer of electric and heat conducting material has a thickness in the range of from 5 to 40 micrometers, preferably from 10 to 30 micrometers.

5. The lighting assembly of claim 1, wherein the heat conducting material is selected from the group consisting of silver, gold, copper, and aluminum.

6. The lighting assembly of claim 5 wherein the heat conducting material is silver.

7. The lighting assembly of claim 1, further comprising a heat sink attached to the attachment surface of the disc.

8. The lighting assembly of claim 1 which emits light having a color rendering index of at least 80.

9. The lighting assembly of claim 8 which emits light having a color rendering index of at least 90.

10. The lighting assembly of claim 1 which emits light having a color temperature in the range of from 2000 to 8000 K.

11. The lighting assembly of claim 10 which emits light having a color temperature in the range of 2000 K to 3000 K.

12. The lighting assembly of claim 1 comprising a first group of at least 4 LEDs and a second group of at least 1 LED, wherein the first group of at least 4 LEDs forms a rectifier circuit bridge.

13. The lighting assembly of claim 12 wherein the first group of LEDs provides a direct current to the second group of LEDs.

14. The lighting assembly of claim 12 wherein the at least 4 LEDs of the first group are red LEDs emitting light having a peak wave length in the range of 600 nm to 630 nm.

15. The lighting assembly of claim 12 wherein the second group of LEDs comprises at least one green LED emitting light having a peak wave length in the range of 500-560 nm, and at least one blue LED emitting light having a peak wave length in the range of 460-500 nm.

16. The lighting assembly of claim 15 wherein the second group of LEDs consists of 3 green LEDs and one blue LED.

17. The lighting assembly according to claim 13 having a current regulating circuit across the rectifier bridge for adjusting the direct current supplied to the at least one LED of the second group.

18. The lighting assembly of claim 13 wherein the current regulating circuit comprises a phototransistor.

19. The lighting assembly according to claim 14 further comprising at least one amber LED emitting light having a peak wave length in the range of 570 to 590 nm.

20. The lighting assembly according to claim 12 which is fed from an AC power source.

21. The lighting assembly of claim 12 which is fed from a DC power source.

22. The lighting assembly of claim 1 wherein at least one of the LEDs is protected from electrostatic discharge by a varistor in parallel with the at least one LED.

23. The lighting assembly according to claim 1 wherein the disc of ceramic material has an edge, and the layer of heat conducting material has a distance of at least 1 mm from said edge.

24. The lighting assembly according to claim 23, wherein said distance is at least 4 mm.

25. The lighting assembly of claim 1 wherein the LED or LEDs are encapsulated in a hemispheric half ball of substantially transparent material.

26. The lighting assembly of claim 23 wherein the substantially transparent material is an epoxy material or a silicone or polyurethane material.

27. The lighting assembly of claim 1 wherein the color of the emitted light may be adjusted along the black body curve.

28. The lighting assembly of claim 1 having a galvanic insulation of at least 3 kV.

29. The lighting assembly of claim 1 wherein the LEDs are of the horizontal type.

30. The lighting assembly of claim 1 wherein the LEDs are of the vertical type.

31. The lighting assembly of claim 30 wherein the LEDs have similar planar radiation patterns.

32. The lighting assembly of claim 1 wherein the LEDs are arranged in a pattern having at least one axis of symmetry.

33. The lighting assembly of claim 1 comprising at least 2 LEDs, wherein at least 1 LED is of the horizontal type and at least 1 LED is of the vertical type.