LIGHTING DEVICE FOR A MOTOR VEHICLE

Abstract

Lighting device for a motor vehicle including a light source and/or an optical part. A substrate including electrical tracks, the light source and/or optical part being fastened to the substrate, and a part forming an electrical ground for the electrical tracks. The substrate includes a cut-out forming a tab, electrical tracks of the substrate extending onto the tab, at least one of the tracks on the tab making electrical contact with the ground-forming part.

Claims

1. A lighting device for a motor vehicle, comprising a light source and/or an optical part, a substrate comprising electrical tracks, said light source and/or optical part being fastened to said substrate, and a part forming an electrical ground for said electrical tracks, characterized in that the substrate comprises a cut-out forming a tab, electrical tracks of the substrate extending onto said tab, at least one of said tracks on said tab making electrical contact with the ground-forming part.

2. The lighting device as claimed in claim 1, wherein the ground-forming part is a heat sink.

3. The lighting device as claimed in claim 2, wherein the tab comprises at least one deposit of an electrically conductive material on at least a portion of the tracks of the tab in electrical contact with the ground-forming part.

4. The lighting device as claimed in claim 3, wherein said deposit forms a protuberance.

5. The lighting device as claimed in claim 2, wherein the ground-forming part comprises at least one protuberance arranged so as to ensure electrical contact with at least a portion of the tracks of the tab.

6. The lighting device as claimed in claim 2, wherein the cut-out is a slot.

7. The lighting device as claimed in claim 2, wherein the tab extends between a base and a free end, the base being adjacent to a means for fastening the substrate to a frame of the lighting device.

8. The lighting device as claimed in claim 7, wherein the fastening means is a screw.

9. The lighting device as claimed in claim 2, wherein it comprises an optical system arranged to deviate a light beam emitted by the light source and/or the optical part, a position of said optical system being independent of the deformations of the substrate.

10. The lighting device as claimed in claim 2, wherein the contact between the tab and the ground-forming part is maintained by elastic deformation of the tab.

11. The lighting device as claimed in claim 2, wherein the device is a fog light.

12. The lighting device as claimed in claim 3, wherein the ground-forming part comprises at least one protuberance arranged so as to ensure electrical contact with at least a portion of the tracks of the tab.

13. The lighting device as claimed in claim 3, wherein the cut-out is a slot.

14. The lighting device as claimed in claim 3, wherein the tab extends between a base and a free end, the base being adjacent to a means for fastening the substrate to a frame of the lighting device.

15. The lighting device as claimed in claim 3, wherein it comprises an optical system arranged to deviate a light beam emitted by the light source and/or the optical part, a position of said optical system being independent of the deformations of the substrate.

16. The lighting device as claimed in claim 3, wherein the contact between the tab and the ground-forming part is maintained by elastic deformation of the tab.

17. The lighting device as claimed in claim 3, wherein the device is a fog light.

18. The lighting device as claimed in claim 4, wherein the ground-forming part comprises at least one protuberance arranged so as to ensure electrical contact with at least a portion of the tracks of the tab.

19. The lighting device as claimed in claim 4, wherein the cut-out is a slot.

20. The lighting device as claimed in claim 4, wherein the tab extends between a base and a free end, the base being adjacent to a means for fastening the substrate to a frame of the lighting device.

Description

[0065] Other features and advantages of the invention will become apparent from reading the following detailed description of one embodiment, for the understanding of which reference should be made to the appended drawings, in which:

[0066] FIG. 1 is a perspective view of a lighting device for a motor vehicle according to the invention, in which an LED 3 is fastened to the substrate 2 and the ground-forming part 4 is a heat sink in thermal contact with the LED 3,

[0067] FIG. 2a is a view from above of a tab (7) formed by cutting out an edge of the substrate (2),

[0068] FIG. 2b is a view from above of a tab (7) formed by cutting out an edge of the substrate (2), the cut-out (6) forming a slot,

[0069] FIG. 2c is a view from above of a tab (7) formed by cutting out non-adjacently to an edge of the substrate, the cut-out forming a slot,

[0070] FIG. 2d is a view from above of a tab (7) formed by cutting out non-adjacently to an edge of the substrate, said cut-out not forming a slot,

[0071] FIG. 3a shows a tab (7) comprising a base (7b) and a free end (7a) on which a tin deposit forming a protuberance (9) has been made,

[0072] FIG. 3b shows a tab (7) comprising a base (7b) and a free end (7a) on which a tin deposit forming a protuberance (9) has been made, ensuring electrical contact with a ground-forming part (4) comprising a protuberance (4a),

[0073] FIG. 3c shows a tab (7) comprising a base (7b) and a free end (7a) on which a tin deposit forming a protuberance (9) has been made,

[0074] FIG. 4 is a sectional view of a device according to the invention in which an LED is mounted on a submount secured to the heat sink and an optical part is fastened to the substrate,

[0075] FIG. 5 is a perspective view of a fog light according to the invention.

[0076] A lighting device (1) comprises a substrate (2), a ground-forming part (4), and an LED (3), said LED (3) being fastened to the substrate (2). The substrate has a cut-out (6) forming a tab (7).

[0077] In one preferred embodiment illustrated in FIG. 1, the ground-forming part (4) is a heat sink formed of an aluminum element, in thermal contact with the LED (3).

[0078] In the embodiment illustrated in FIG. 1, the frame (5) of the lighting device (1) is molded onto the ground-forming part (4). The cut-out (6) is a void forming a tab (7), which comprises a base (7b) and a free end (7a). The base (7b) is adjacent to a means (8) for fastening the substrate to the frame (5), consisting of a screw. The device comprises an optical system (not shown) arranged so as to deviate the light rays emitted by the LED (3). Said optical system is fastened to the frame (5) of the lighting device (1): the position of said optical system is therefore here independent of deformations of the substrate.

[0079] In the embodiment illustrated in FIG. 3a, the tab (7) comprising a base (7a) and a free end (7b) comprises a tin deposit (9) forming a protuberance. The ground-forming part (4) comprises a protuberance (4a) which cooperates with the tin deposit (9) so as to ensure electrical contact between at least one of the electrical tracks of the tab (7) and the heat sink (4).

[0080] In the embodiment illustrated in FIG. 3b, the tab (7) comprising a base (7a) and a free end (7b) does not comprise a protuberance. The ground-forming part (4) comprises a protuberance (4a) which cooperates with the free end (7b) of the tab so as to ensure electrical contact between at least one of the electrical tracks of the tab (7) and the heat sink (4).

[0081] In the embodiment illustrated in FIG. 3c, the tab (7) comprising a base (7a) and a free end (7b) comprises a tin deposit (9) forming a protuberance. The ground-forming part (4) does not comprise a protuberance; it is a planar surface which cooperates with the free end (7b) of the tab so as to ensure electrical contact between at least one of the electrical tracks of the tab (7) and the heat sink (4).

[0082] In all of the embodiments illustrated in FIGS. 1 to 3b, the tab formed by the cut-out (6) is deformed so as to ensure electrical contact between an electrical track on a free end of the tab (7a) and the heat sink (4), and the base (7b) of the tab is held on the frame by the fastening screw (8). In this way, deformation of the tab (7) does not cause deformation of the substrate: vertical movement of the LED (3) is thus limited and any loss of luminous efficiency of the module (1) is thus prevented.

[0083] In the embodiment illustrated in FIG. 4, the ground-forming part is a heat sink (14) and the light source is a submount-mounted LED (13). Said LED (13) is secured to the heat sink (14), electrically connected to the tracks of the substrate by wire connections, and emits light through a through-opening (20) through the substrate (12). An optical part (21) is fastened to the substrate so as to deviate a light beam emitted by the LED (13). The frame (15) of the lighting device (11) is molded onto the heat sink (14). The cut-out (16) is a void forming a tab (17), which comprises a base (17b) and a free end (17a). The base (17b) is adjacent to a means (18) for fastening the substrate to the frame (15), consisting of a screw. An optical system (not shown) is arranged so as to deviate a light beam from the optical part (21). Said optical system is fastened to the frame (15, not shown) of the lighting device (11): the position of said optical system is therefore independent of deformations of the substrate.

[0084] In the embodiment illustrated in FIG. 4, the tab formed by the cut-out (6) is deformed so as to ensure electrical contact between an electrical track on a free end of the tab (7a) and the heat sink (4), and the base (7b) of the tab is held on the frame by the fastening screw (8). In this way, deformation of the tab (7) does not cause deformation of the substrate: vertical movement of the optical part (3) is thus limited and any loss of luminous efficiency of the module (1) is thus prevented.

[0085] The above description clearly explains how the invention achieves the objectives that were set therefor, and in particular how manufacturing costs due to the use of an added part to ensure contact between the substrate and the ground-forming part are eliminated while limiting movement of the LED and/or of the optical part and/or a decrease in luminous efficiency.

[0086] The invention is not limited to the embodiments specifically given in this document by way of non-limiting examples, and extends in particular to all equivalent means and to any technically operational combination of these means. Thus, the features, variants and various embodiments of the invention may be combined with one another, in various combinations, as long as they are not mutually incompatible or mutually exclusive.