Light-emitting diode arrangement and motor vehicle headlamp

• US 20060076572A1
• Filed: 09/29/2005
• Published: 04/13/2006
• Est. Priority Date: 09/29/2004
• Status: Active Grant

• Current Assignee: OSRAM OLED GMBH (Ams-Osram AG)
• Original Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Inventors: Huber, Rainer, Hofmann, Markus, Wanninger, Mario, Sailer, Michael, Reill, Joachim, Engl, Moritz, Grotsch, Stefan, Lang, Kurt-Jurgen
• Granted Patent: US 7,683,395 B2
• Time in Patent Office: Days
• US Class Current: 257/99
• CPC Class Codes: F21S 41/143 the main emission direction of the LED being parallel to the optical axis of the illuminating device
• CPC Class Codes: F21S 45/435 circulating the gas within a closed system
• CPC Class Codes: F21S 45/46 using liquid
• CPC Class Codes: F21S 45/47 Passive cooling, e.g. using fins, thermal conductive elements or openings
• CPC Class Codes: F21S 45/48 with means for conducting heat from the inside to the outside of the lighting devices, e.g. with fins on the outer surface of the lighting device
• CPC Class Codes: F21S 45/49 Attachment of the cooling means
• CPC Class Codes: F21S 45/60 Heating of lighting devices, e.g. for demisting
• CPC Class Codes: F21V 29/51 using condensation or evaporation of a fluid, e.g. heat pipes
• CPC Class Codes: F21V 29/67 characterised by the arrangement of fans
• CPC Class Codes: F21V 29/71 using a combination of separate elements interconnected by heat-conducting means, e.g. with heat pipes or thermally conductive bars between separate heat-sink elements
• CPC Class Codes: F21V 29/89 Metals
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A light-emitting diode arrangement having at least one light-emitting diode chip (1), each light-emitting diode chip (1) being assigned at least one optical element (4). In addition, the light-emitting diode arrangement has at least one heat-conducting element (13) which is suitable to carry away the heat generated by the light-emitting diode chip, and at least one cooling apparatus which is suitable to carry heat away from the heat-conducting element. The light-emitting diode arrangement is particularly well suited, for example, to use in motor vehicle headlamps.

Claims

1. Light-emitting diode arrangement, comprising:

at least one light-emitting diode chip (1), each light-emitting diode chip (1) being assigned at least one optical element (4);

at least one heat-conducting element (13) which is suitable to carry away the heat generated by the light-emitting diode chips; and

at least one cooling apparatus which is suitable to pick up the heat carried away by the heat-conducting element.

2. The light-emitting diode arrangement according to claim 1, in which at least one of the light-emitting diode chips (1) is a thin-film light-emitting diode chip.

3. The light-emitting diode arrangement according to claim 1, in which the optical element (4) is at least partly formed in the manner of at least one of the following optical elements:

CPC, CEC, CHC.

4. The light-emitting diode arrangement according to claim 1, in which the optical element (4) has a radiation input opening (b) which has an area which is at most twice as large as a total radiation output surface of the light-emitting diode chips (1) assigned to the optical element (4).

5. The light-emitting diode arrangement according to claim 1, in which a cooling element (14) is applied to the heat-conducting element.

6. The light-emitting diode arrangement according to claim 1, in which the cooling apparatus is suitable to carry away heat by means of free or forced convection.

7. The light-emitting diode arrangement according to claim 1, in which the cooling apparatus is provided by at least one of the following heat-conducting elements:

heat-conducting material (20), heat pipe (24), thermosyphon (23), liquid cooling system circuit (21).

8. The light-emitting diode arrangement according to claim 1, in which the cooling apparatus is suitable for transporting heat generated by the light-emitting diode chips to a location at which it is used for specific heating.

9. The light-emitting diode arrangement according to claim 1, in which the heat generated by the light-emitting diode chips (1) is used for de-icing.

10. A motor vehicle headlamp having a light-emitting diode arrangement according to claim 1, which is provided as a light source (11) of the motor vehicle headlamp.

11. The motor vehicle headlamp according to claim 10, in which a cooling apparatus carries the heat generated by light-emitting diode chips (1) of the light-emitting diode arrangement away to a covering glass (25a, 25b) of the motor vehicle headlamp, the heat being used there for heating the covering glass.

12. The motor vehicle headlamp according to claim 10, in which the cooling apparatus carries the heat generated by the light-emitting diode chips (1) away to the covering glass (25a, 25b) of a motor vehicle headlamp, the heat being used there for de-icing the covering glass (25a, 25b).

13. The motor vehicle headlamp according to claim 10, in which the cooling apparatus carries the heat generated by the light-emitting diode chips (1) away to an optical element (18) of the motor vehicle headlamp, the heat being used there for heating the optical element (18).

14. The motor vehicle headlamp according to claim 10, in which the cooling apparatus carries the heat generated by the light-emitting diode chips (1) away to the optical element (18) of the motor vehicle headlamp, the heat being used there for de-icing the optical element (18).

15. The motor vehicle headlamp according to claim 10, in which the cooling apparatus comprises at least one of the following elements:

cooling element (14), fan (19), heat-conducting material (20), heat pipe (24), thermosyphon (23), liquid circuit (21), wire (27).

16. The motor vehicle headlamp according to claim 10, in which an absorber (28) which is suitable to convert an infrared or UV radiation into heat is applied to the covering glass (25a, 25b) of the motor vehicle headlamp.

17. The motor vehicle headlamp according to claim 10, which, in addition to the light-emitting diode chip (1), contains an infrared LED (30) which irradiates the covering glass (25a, 25b) of the motor vehicle headlamp.