Lighting and/or signaling device for a motor vehicle incorporating a material having thermal anisotropy

• US 7,621,664 B2
• Filed: 09/27/2006
• Issued: 11/24/2009
• Est. Priority Date: 09/30/2005
• Status: Active Grant

• Current Assignee: Valeo Vision (Valeo SE)
• Original Assignee: Valeo Vison
• Inventors: Nicolai, Jean-Marc
• Primary Examiner(s): Ward; John A
• Application Number:
  US11/535,590
• Publication Number:
  US 20070076422A1
• Time in Patent Office: 1,154 Days
• Field of Search: 362/545, 362/547, 362/249, 362/548, 423/448
• US Class Current: 362/547
• CPC Class Codes: B60Q 1/0041 of several lamps in relation to each other
• CPC Class Codes: B60Q 1/10 due to vehicle inclination, e.g. due to load distribution
• CPC Class Codes: B60Q 1/1415 Dimming circuits
• CPC Class Codes: F21S 41/148 the main emission direction of the LED being perpendicular to the optical axis
• CPC Class Codes: F21S 41/151 arranged in one or more lines
• CPC Class Codes: F21S 41/663 by switching light sources by switching incandescent light sources F21S41/162
• CPC Class Codes: F21S 43/14 Light emitting diodes [LED]
• CPC Class Codes: F21S 45/43 using gas
• CPC Class Codes: F21S 45/47 Passive cooling, e.g. using fins, thermal conductive elements or openings
• CPC Class Codes: F21V 25/00 Safety devices structurally associated with lighting devices gas- tight or water-tight arrangements F21V31/00; in general F16P; protective circuit arrangements per se H02H7/00
• CPC Class Codes: F21V 29/74 with fins or blades
• CPC Class Codes: F21V 29/75 with fins or blades having different shapes, thicknesses or spacing
• CPC Class Codes: F21V 29/763 the planes containing the fins or blades having the direction of the light emitting axis
• CPC Class Codes: F21V 29/767 the planes containing the fins or blades having directions perpendicular to the light emitting axis
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: F28D 2021/0029 Heat sinks
• CPC Class Codes: F28F 21/02 of carbon, e.g. graphite

Abstract

The device comprises at least one power light emitting diode light source and other means able to constitute one or more heat sources of such a nature as to affect the thermal environment of the light emitting diode light source. In accordance with the invention, the device also comprises a support piece formed at least partially from a material based on anisotropic graphite supporting the light emitting diode light source and opposing an effect of the other means on the thermal environment of the light emitting diode light source. According to other characteristics, the support piece comprises at least one thermal dissipation heat sink and the device can comprise a fan able to force a circulation of air through the heat sink.

Claims

1. A lighting and/or signaling device for a motor vehicle comprising at least one power light emitting diode light source and at least one other light source of heat, comprising a support piece at least partially formed from a material comprising an anisotropic graphite, said support piece comprising a first surface for supporting said power light emitting diode light source and a second surface for separating said power light emitting diode light source from said at least one other light source of heat to oppose an effect of heat from said at least one other light source of heat on a thermal environment of said at least one power light emitting diode light source, each of said first surface and said second surface comprising anisotropic properties that facilitate transferring heat away from each of said at least one power light emitting diode light source and said at least one other light source of heat;

wherein said second surfaces comprise a wall separating said at least one power light emitting diode light source from the said at least one other light source of heat;

wherein said wall has a thermal resistance greater across its thickness than longitudinally.

2. The lighting and/or signaling device according to claim 1, wherein said support piece comprises at least one thermal dissipation heat sink.

3. The lighting and/or signaling device according to claim 2, wherein said at least one thermal dissipation heat sink comprises at least one part formed from a different material based on anisotropic graphite, said part having a privileged thermal conductivity direction that is parallel to a plurality of fins on said thermal dissipation heat sink.

4. The lighting and/or signaling device according to claim 2, wherein said at least one thermal dissipation heat sink comprises at least one part made from aluminum.

5. The lighting and/or signaling device according to claim 2, wherein said at least one thermal dissipation heat sink comprises at least one part formed from a material based on anisotropic graphite, said part having a privileged thermal conductivity direction that is parallel to a plurality of fins on said thermal dissipation heat sink, wherein said support piece and said at least one thermal dissipation heat sink being an integral one-piece construction.

6. The lighting and/or signaling device according to claim 1, further comprising at least one element conferring mechanical strength on the support.

7. The lighting and/or signaling device according to claim 6, wherein said at least one element comprises at least one electronic substrate on which said power light emitting diode light source is mounted.

8. The lighting and/or signaling device according to claim 6, wherein said at least one element comprises at least two rigid plates disposed, in a sandwich configuration, on each side of at least part of the material based on anisotropic graphite.

9. The lighting and/or signaling device according to claim 8, wherein at least one of said at least two rigid plates consists of an electronic substrate on which said at least one power light emitting diode light source is mounted.

10. The lighting and/or signaling device according to claim 8, wherein at least one of said at least two rigid plates is a plate forming an earth plane able to fulfill an electromagnetic shielding function.

11. The lighting and/or signaling device according to claim 1, wherein said at least one other light source of heat comprises at least one light source amongst the following:

a power light emitting diode light source, an incandescent lamp and a discharge lamp.

12. The lighting and/or signaling device according to claim 1, wherein said support piece comprises a plurality of walls, in particular disposed obliquely or perpendicular to one another.

13. The lighting and/or signaling device according to claim 1, wherein said support piece comprises a plurality of walls that are mono- or multi-component.

14. A motor vehicle, comprising one lighting and/or signaling device according to claim 1.

15. A lighting and/or signaling device for a motor vehicle comprising at least one power light emitting diode light source and at least one other light source of heat, comprising a support piece at least partially formed from a material comprising an anisotropic graphite, said support piece comprising a first surface for supporting said rower light emitting diode light source and a second surface for separating said rower light emitting diode light source from said at least one other light source of heat to oppose an effect of heat from said at least one other light source of heat on a thermal environment of said at least one rower light emitting diode light source, each of said first surface and said second surface comprising anisotropic properties that facilitate transferring heat away from each of said at least one rower light emitting diode light source and said at least one other light source of heat;

wherein said support piece comprises at least one thermal dissipation heat sink;

wherein said lighting and/or signaling device comprises a fan able to force a circulation of air through said at least one thermal dissipation heat sink.

16. A lighting and/or signaling device for a motor vehicle comprising at least one rower light emitting diode light source and at least one other light source of heat, comprising a support piece at least partially formed from a material comprising an anisotropic graphite, said support piece comprising a first surface for supporting said rower light emitting diode light source and a second surface for separating said rower light emitting diode light source from said at least one other light source of heat to oppose an effect of heat from said at least one other light source of heat on a thermal environment of said at least one rower light emitting diode light source, each of said first surface and said second surface comprising anisotropic properties that facilitate transferring heat away from each of said at least one rower light emitting diode light source and said at least one other light source of heat;

which comprises means cooperating with said support piece so as to allow a rotational adjustment, along at least one predetermined axis, of said support piece.

17. A lighting and/or signaling device for a motor vehicle comprising:

a support;

at least one power light emitting diode mounted on said support; and

at least one other light source of heat;

said support comprising a first surface for supporting said at least one power light emitting diode and a second surface for separating said at least one power light emitting diode from said at least one other light source of heat to oppose an effect of heat from said at least one other light source of heat on a thermal environment of said at least one power light emitting diode;

said support comprising anisotropic graphite and each of said first surface and said second surface comprising anisotropic properties that facilitate transferring heat away from each of said at least one power light emitting diode and said at least one other light source of heat;

wherein said second surfaces comprise a wall separating said at least one rower light emitting diode light source from the said at least one other light source of heat;

wherein said wall has a thermal resistance greater across its thickness than longitudinally.

18. The lighting and/or signaling device as recited in claim 17 wherein said support provides a heat screen between said at least one power light emitting diode and said at least one other light source of heat.

19. The lighting and/or signaling device as recited in claim 17 wherein said support comprises different thermal conductivities on at least two axes.

20. The lighting and/or signaling device as recited in claim 17 wherein said support is a composite construction comprising at least one of the following combinations of two materials:

natural graphite/anisotropic graphite, ceramic/anisotropic graphite or aluminum/anisotropic graphite.

21. The lighting and/or signaling device as recited in claim 17 wherein said support comprises a plurality of components, at least one of said plurality of components being generally L-shaped or T-shaped in cross-section;

said plurality of components comprising different materials.

22. The lighting and/or signaling device as recited in claim 17 wherein said support is a one-piece molded construction.

23. The lighting and/or signaling device as recited in claim 17 wherein said support comprises a plurality of components, at least one of said plurality of components being generally L-shaped or T-shaped in cross-section;

said support further comprising;

a heat sink secured to said L-shaped or T-shaped component.

24. The lighting and/or signaling device according to claim 17, wherein said at least one other light source of heat comprises at least one light source amongst the following:

a power light emitting diode light source, an incandescent lamp and a discharge lamp.