Light-emitting diode arrangement and motor vehicle headlamp

• US 7,683,395 B2
• Filed: 09/29/2005
• Issued: 03/23/2010
• 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: Sailer, Michael, Huber, Rainer, Hofmann, Markus, Wanninger, Mario, Reill, Joachim, Grötsch, Stefan, Engl, Moritz, Lang, Kurt-Jürgen
• Primary Examiner(s): Purvis; Sue
• Assistant Examiner(s): QUINTO, KEVIN V
• Application Number:
  US11/239,723
• Publication Number:
  US 20060076572A1
• Time in Patent Office: 1,636 Days
• Field of Search: 257/79, 257/88, 257/89, 257/90, 257/91, 257/92, 257/93, 257/98, 257/99, 257/100, 257/E33.055, 257/E33.075, 362/459, 362/487, 362/502, 362/503, 362/504, 362/505, 362/506, 362/507
• 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. A motor vehicle headlamp with a light-emitting diode arrangement which is provided as a light source of the motor vehicle, comprising:

at least one light-emitting diode chip, each light-emitting diode chip being assigned at least one optical element;

at least one heat-conducting element configured to dissipate heat generated by the at least one light-emitting diode chip; and

at least one cooling apparatus configured to conduct the heat carried away by the heat-conducting element;

wherein the at least one cooling apparatus conducts the heat generated by the at least one light-emitting diode chip of the light-emitting diode arrangement to one of a covering glass and an optical element of the motor vehicle headlamp for heating said one of the covering glass and the optical element;

wherein the at least one cooling apparatus comprises at least one of a heat pipe and wire; and

wherein the at least one cooling apparatus is in direct contact with at least one of the covering glass and the optical element to conduct the generated heat to the at least one of the covering glass and the optical element.

2. The light-emitting diode arrangement according to claim 1, wherein said at least one light-emitting diode chip comprises a thin-film light-emitting diode chip.

3. The light-emitting diode arrangement according to claim 1, wherein the optical element is at least partly formed as at least one of the following optical elements:

a compound parabolic concentrator (CPC), a compound elliptic concentrator (CEC) and a compound hyperbolic concentrator (CHC).

4. The light-emitting diode arrangement according to claim 1, wherein the optical element includes a radiation input opening having an area which is at most twice as large as a total radiation output surface of said at least one light-emitting diode chip assigned to the optical element.

5. The light-emitting diode arrangement according to claim 1, further comprising a cooling element applied to the at least one heat-conducting element.

6. The light-emitting diode arrangement according to claim 1, wherein the at least one cooling apparatus is configured to conduct heat by free or forced convection.

7. The light-emitting diode arrangement according to claim 1, wherein the cooling apparatus is configured to transport heat generated by the at least one light-emitting diode chip to a location at which said heat is used for specific heating.

8. The light-emitting diode arrangement according to claim 1, wherein the heat generated by the at least one light-emitting diode chip is used for de-icing.

9. The motor vehicle headlamp according to claim 1, wherein the cooling apparatus conducts the heat generated by the at least one light-emitting diode chip to the covering glass of the motor vehicle headlamp for de-icing the covering glass.

10. The motor vehicle headlamp according to claim 1, wherein the cooling apparatus conducts the heat generated by the at least one light-emitting diode chip to the optical element of the motor vehicle headlamp for de-icing the optical element.

11. The motor vehicle headlamp according to claim 1, further comprising an absorber configured to convert an infrared or UV radiation into heat and applied to the covering glass of the motor vehicle headlamp.

12. The motor vehicle headlamp according to claim 1, further comprising an infrared LED which irradiates the covering glass of the motor vehicle headlamp.