Light module and lighting device for a motor vehicle comprising such a light module

Abstract

A light module includes at least one light source, a light source support, and an optical element suitable for receiving rays emitted by the light source. The optical element includes structure for positioning the optical element in a predefined position on the support and an elastic attachment device for attaching the optical element in the predefined position on the support.

Claims

1. A light module comprising: a printed circuit board comprising a series of light sources mounted along a transverse direction on a front face of the printed circuit board such that each light source has a light emitting path which extends along a longitudinal direction away from the front face of the printed circuit board; an optical element coupled to the printed circuit board, the optical element comprising a series of microlenses arranged along the transverse direction; an alignment mechanism configured to align the optical element with the printed circuit board such that each microlens in the series of microlenses is provided in the light emitting path of a respective one of the light sources in the series of light sources; and a heat conduction member shaped and dimensioned to correspond to the printed circuit board, the heat conducting member being fixed to the printed circuit board such that a front face of the heat conduction member is coupled to a rear face of the printed circuit board to conduct heat generated by the series light sources away from the series of microlenses.

2. The light module of claim 1, wherein the heat conduction member is a metal heat conduction member.

3. The light module of claim 1, wherein the heat conduction member further comprises a light module mounting hole for mounting the heat sink of the housing to the light module.

4. The light module of claim 2, wherein: the printed circuit board further comprises electrical components mounted only on the front face of the printed circuit board, and the rear face of the printed circuit board is a smooth surface of insulating material which contacts the front face of the metal heat conduction member to conduct heat generated by the series light sources away from the series of microlenses.

5. The light module according to claim 4, further comprising at least one screw to attach the metal heat conduction member to the printed circuit board.

6. The light module of claim 1, wherein the alignment mechanism comprises: at least one indexing pin coupled to the optical element, and at least one indexing opening in the printed circuit board, wherein each indexing opening being shaped and dimensioned to correspond to a respective indexing pin such that the at least one indexing pin engages a respective one of the at least one indexing opening to align the series of microlenses with the series of lighting devices when the lighting module is assembled.

7. The light module of claim 6, wherein the a heat conduction member further comprises at least one additional indexing opening being shaped and dimensioned to correspond to a respective indexing pin such that the at least one indexing pin further engages a respective one of the at least one additional indexing opening of the heat conduction member when the lighting module is assembled.

8. The light module of claim 1, wherein the at least one indexing pin is an integral part of the optical element.

9. The light module of claim 1, wherein the at least one indexing pin and the optical element are made of different materials as separate parts of an optical element assembly.

10. The light module of claim 1, wherein the heat conduction member further comprises a light module mounting hole.

11. A light module assembly comprising: a plurality of the light modules of claim 10; a heat sink having a plurality of mounting surfaces each being configured to receive a respective one of the plurality of light modules, each mounting surface having at least one heat sink mounting hole corresponding to a respective one of the light module mounting holes; and a plurality of screws each engaging a respective light module mounting hole and a corresponding heat sink mounting hole when the plurality of light modules are mounted on respective mounting surface of the heat sink.

12. The light module assembly of claim 11, wherein a rear face of each heat conduction member contacts a respective mounting surface of the heat sink such that the heat conduction member conducts heat toward the heat sink and away from the microlenses.

13. A light device for a vehicle comprising: a housing for the light device, the housing comprising: a heat sink having a vertical wall including a front face including a mounting surface and a rear face including heat fins, and a lens having a rear input surface facing the mounting surface of the heat sink, the lens being coupled to the heat sink such that the rear input surface of the lens is spaced apart from the mounting surface of the heat sink along a longitudinal direction of the light device; and a light module mounted to the mounting surface of the heat sink, the light module comprising: a printed circuit board comprising a series of light sources mounted along a transverse direction on a front face of the printed circuit board such that each light source has a light emitting path which extends along the longitudinal direction away from the front face of the printed circuit board; an optical element coupled to the printed circuit board, the optical element comprising a series of microlenses arranged along the transverse direction; an alignment mechanism configured to align the optical element with the printed circuit board such that each microlens in the series of microlenses is provided in the light emitting path of a respective one of the light sources in the series of light sources; and a heat conduction member shaped and dimensioned to correspond to the printed circuit board, the heat conducting member being fixed to the printed circuit board such that a front face of the heat conduction member is coupled to a rear face of the printed circuit board, at least one screw configured to attach the light module to the mounting surface of the heat sink such that the light path of each of the light sources is incident on the rear face of the lens.

14. The light device of claim 13, wherein a rear face of the heat conduction member is coupled to the mounting surface of the heat sink such that the heat conduction member conducts heat toward the heat sink and away from the microlenses.

15. The light device of claim 14, wherein: the heat conduction element is a metal heat conduction element, the printed circuit board further comprises electrical components mounted only on the front face of the printed circuit board, and the rear face of the printed circuit board is a smooth surface of insulating material which contacts the front face of the metal heat conduction member to conduct heat generated by the series light sources away from the series of microlenses.

16. The light device of claim 15, further comprising at least one screw to attach the metal heat conduction member to the printed circuit board.

17. The light device of claim 13, wherein the alignment mechanism comprises: at least one indexing pin coupled to the optical element, and at least one indexing opening in the printed circuit board, wherein each indexing opening being shaped and dimensioned to correspond to a respective indexing pin such that the at least one indexing pin engages a respective one of the at least one indexing opening to align the series of microlenses with the series of lighting devices when the lighting module is assembled.

18. The light device of claim 17, wherein the a heat conduction member further comprises at least one additional indexing opening being shaped and dimensioned to correspond to a respective indexing pin such that the at least one indexing pin further engages a respective one of the at least one additional indexing opening of the heat conduction member when the lighting module is assembled.

19. The light module of claim 13, wherein the at least one indexing pin is an integral part of the optical element.

20. The light module of claim 13, wherein the at least one indexing pin and the optical element are made of different materials as separate parts of an optical element assembly.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Other features, details and advantages of the invention will become clearer on reading the description that follows as a non-limiting example, with reference to the appended drawings in which:

(2) FIG. 1 is an exploded view of a light module according to a first embodiment of the invention, representing, in particular, the front faces of the elements that constitute the module,

(3) FIG. 2 is an exploded view of the light module of FIG. 1, in particular showing the rear faces of the elements shown in FIG. 1,

(4) FIG. 3 is a perspective view of an assembled light module, according to a first embodiment of the invention,

(5) FIG. 4 is a perspective view of a lighting device comprising several light modules according to the invention, and

(6) FIG. 5 is an exploded view of a light module according to a second embodiment of the invention, from a perspective similar to that of FIG. 1.

DETAILED DESCRIPTION

(7) In the figures, the parts shown in more than one figure have been given the same reference number.

(8) Hereinafter, the terms longitudinal, vertical and transverse refer to directions relative to an axis corresponding to the general direction of the rays emitted by the light source. The longitudinal direction corresponds to the general direction of the light rays emitted by the light source. The front/forward direction denotes the direction in which the light rays are emitted by the light source, the rear/backward direction designating the opposite direction.

(9) The abovementioned directions can also be seen as an L, V, T trihedron shown in the figures.

(10) The light module 1 comprises at least one light source 2, a light source 2 support 3 and an optical element 4 arranged in the path of the rays emitted by the light source 2, in particular to deflect them and arrange them to help create a motor vehicle lighting and/or signaling beam.

(11) In a first embodiment of the invention, shown in FIGS. 1 to 4, the light module 1 comprises five light sources 2.

(12) The support 3 is generally in the form of a thin panel, delimited by a first face 39 on which the light sources 2 are arranged, and a second face 391 opposite the first. These two faces are delimited by an upper edge, a lower edge, and two side edges. The support 3 can, in particular, comprise a printed circuit board, on which the light sources 2 and electronic components are arranged.

(13) The end of the first face 39 of the support 3 in the vicinity of the upper edge is narrower than the end of the first face 39 in the vicinity of the lower edge. The reduction in width is produced by at least one narrowed area 36 formed by a shoulder 37, which creates a bearing surface 38 substantially parallel to the upper edge of the support 3.

(14) The light sources 2 are arranged on the part of the support 3 arranged between the narrowed area 36 and the lower edge. The light sources 2 are arranged in a transverse series, perpendicular to the side edges of the support 3.

(15) The support 3 comprises, on the first face 39 between the lower edge and the light sources 2, one or more electronic components 31. These electronic components 31 may be of any type and nature allowing a function to be performed in connection with the light module 1, such as the selective activation of one or more light sources 2.

(16) The support 3 further comprises a first indexing opening 32 and a second indexing opening 33, one arranged in the vicinity of the upper edge of the support 3 and the other in the vicinity of the lower edge. In the example shown, these openings 32 and 33 have a cylindrical or essentially cylindrical cross section. The two indexing openings 32 and 33 can be through-openings, i.e. extending from one face of the support 3 to the other.

(17) The support 3 further comprises an oblong indexing hole 34, which is arranged in the vicinity of the first indexing opening 32 and the light sources 2, and a central through-bore 35.

(18) The optical element 4 is arranged facing the first face 39 of the support 3, i.e. the face on which the light sources 2 are arranged. The optical element 4 is in the form of a thin panel, delimited by an inner face 49 that faces the support 3 when the light module is assembled, and an outer face 40 opposite the inner face 49. The width and thickness of the optical element 4 are essentially identical to those of the support 3, and it is shorter in length than the support 3. According to the orientation chosen and shown, in particular, in FIG. 1, the width corresponds to the dimension of the optical element 4 and the support 3 in the transverse direction, the thickness corresponds to the dimension of the optical element 4 and the support 3 in the longitudinal direction, and the length corresponds to the dimension of the optical element 4 and the support 3 in the vertical direction.

(19) The optical element 4 comprises an elastic holding portion 62, a portion 64 for treating the light rays and an attachment portion 66.

(20) The portion 64 for treating the light rays of the optical element 4 comprises one or more microlenses 42, which are arranged in a transverse series in the example shown. The microlens or microlenses 42 protrude from the outer face 40 of the optical element 4, being hemispherical or essentially hemispherical in shape and arranged to cooperate with the light sources 2. As described below, the microlenses 42 are aligned facing the light sources 2 when the optical element 4 is fitted against the support 3, having a longitudinal clearance so as not to crush the light sources 2 when the optical element 4 is pressed against the support 3. The microlenses 42 cooperate with the light sources 2 so as to project the light rays emitted by the light sources 2 in a controlled manner.

(21) These microlenses 42 form primary optical elements 41 when, as described below, the light module 1 formed in part by the optical element 4 is mounted in a lighting device 10 that further comprises a projection lens 104 that thus forms a secondary optical element.

(22) The optical element 4 further comprises a recess 43 and the microlenses 42 are arranged along one of the edges delimiting said recess. In the example shown, the recess is essentially rectangular in shape. It should be noted that the role of this recess 43 is to allow the heat produced by the light sources 2 to be released by air circulation.

(23) Between the portion 64 for treating the light rays and the attachment portion 66, the optical element 4 comprises an arrangement 44 designed to create a clearance between the optical element 4 and the support 3 when said two parts are pressed together. It is therefore possible to arrange a bulky electronic component on the support 3.

(24) The optical element 4 comprises, on the inner face 49, an indexing pin 45 (shown in FIG. 2) that is oblong in shape, arranged on an edge delimiting the recess 43 opposite the microlenses 42. Thus, when the light module 1 is being assembled, the indexing pin 45 of the optical element 4 extends towards the support 3.

(25) The attachment portion 66 of the optical element 4 comprises a through-bore 47. In the example shown, the bore 47 is circular in shape.

(26) The elastic holding portion 62 of the optical element 4 comprises two elastic attachment means 46 arranged respectively on each of the side edges of the optical element 4. These elastic attachment means 46 are arranged on either side of the optical element 4, in the vicinity of the upper edge of the optical element 4. The elastic attachment means 46 extend the panel forming the support element in a substantially perpendicular direction, on the side of the inner face 49, i.e. said elastic attachment means 46 extend in the opposite direction to the microlenses 42.

(27) Each elastic attachment means 46 comprises a frame 461 and an elastic blade 462.

(28) The frame 461 is formed by two longitudinal posts 463 that are integral with the panel of the optical element 4 and extend it in a substantially perpendicular direction, at one of the side edges of the optical element 4. The two longitudinal posts 463 are linked at their free end by a segment 464 which is thus arranged at a distance from the panel of the optical element 4 and carries, at its middle, the elastic blade 462, which extends from the segment 464 in the direction approaching the panel of the optical element 4. This elastic blade 462 is inclined relative to the parallel longitudinal posts 463 insofar as it extends towards the inside of the optical element 4. In other words, it has a transverse component so as to extend in a direction approaching the elastic blade 462 of the other elastic attachment means 46.

(29) As described in greater detail below, the elastic attachment portion 66 is configured in such a way that, when the optical element 4 is in the predefined position, each of the frames 461, and in particular the lower longitudinal post 463, rests on the bearing surface 38 formed by the corresponding shoulder 37 of the support 3, and the free end of each elastic blade 462, opposite the segment 464, is in contact with the second face 391 of the support. The cooperation of the posts 463 and elastic blades 462 of the optical element 4 with the appropriate shapes provided on the support 3 help hold the optical element 4 in position.

(30) The light module 1 further comprises a heat conduction member 8 against which the support 3 presses. The heat conduction member 8 comprises a base 5, the shapes and dimensions of which are essentially similar to those of the support 3.

(31) The base 5 has a contact face 50 on which at least a first indexing lug 51 and a second indexing lug 52 are provided, the shape of which matches the first and second openings 32 and 33 provided in the support. When the support 3 is fitted against the base 5, these indexing lugs 51 and 52 are arranged opposite the indexing openings 32 and 33 of the support 3, so as to allow the support 3 to be positioned relative to the base 5.

(32) The base 5 also comprises, on the face opposite the contact face 50 against which the support 3 presses, at least one first gripping finger 55 that extends the base 5 in a substantially perpendicular direction and is arranged at an end of the base 5 in the vicinity, in this case, of the upper edge. In the example shown, a second gripping finger 56 is provided such that said gripping fingers 55 and 56 are each arranged at one end of the base 5. The gripping fingers 55 and 56 can extend over all or part of the width of the base 5.

(33) The gripping fingers 55 and 56 are both intended to allow the base 5 to be gripped in order to allow said base 5, and therefore the entire light module 1, to be oriented correctly before it is attached to a lighting and/or signaling device in the vehicle. For this purpose, the first gripping finger 55 comprises two gripping openings 57 and 58 configured to cooperate with any machine tool that can be used for producing, assembling or adjusting the light module 1. The gripping openings 57 and 58 are arranged on the upper face of the first gripping finger 55. In the embodiment of the example, one of the gripping openings 57 and 58 is a through-opening, and the other is not.

(34) The base 5 further comprises an attachment hole 59 that extends through the thickness of the base from the face opposite the contact face 50 against which the support 3 is pressed. In the example shown, this attachment hole 59 is a through-hole, i.e. it opens on the contact face 50, but it should be noted that it can be a blind hole. As detailed below, the purpose of this attachment hole 59 is to help attach the base 5 and therefore the whole of the light module 1 on a housing of a lighting and/or signaling device. It can, in particular, be tapped in order to receive an attachment screw 7.

(35) Moreover, the base 5 comprises an oblong indexing ring 53, the shape of which is substantially equal to the oblong shape of the indexing hole 34 provided in the support 3.

(36) The base 5 also comprises, substantially at its center, a threaded bore 54, which extends through the thickness of the base 5 from the contact face 50 arranged to be in contact with the support 3. In the example shown, it can be seen, in particular, that the threaded bore 54 is not a through-bore and is actually a blind bore.

(37) The indexing pin 45 of the optical element 4 is arranged to cooperate with the indexing hole 34 and the indexing ring 53 in order to help position the optical element 4 on the support 3.

(38) In reference to FIG. 4, there now follows a description of the light module 1 formed by the cooperation of each of the elements described above. FIG. 3 shows a light module 1 assembled according to the invention.

(39) First, the support 3 is arranged on the heat conduction member 8, and more particularly on its base 5. For this purpose, the second face 391 of the support 3 is positioned facing the contact face 50. The edges of the base 5 and of the support 3 are substantially aligned, thus matching up the indexing means. The indexing lugs 51 and 52 carried by the base 5 penetrate into the indexing openings 32 and 33 provided in the support, thus positioning the support 3 relative to the base 5. In this relative position, the indexing ring 53 is positioned facing the indexing hole 34 of the support 3, and the central bore 35 of the support 3 is aligned with the central threaded bore 54 arranged on the base 5. It should be noted that the diameter of the central bore 35 is greater than that of the central threaded bore 54.

(40) The optical element 4 is then arranged on the support 3, bringing the inner face 49 of the optical element 4 to face the first face 39 of the support 39. The elastic attachment means 46 are then turned towards the support 3. First, the optical element 4 is pre-positioned by resting the lower longitudinal post 463 of the frame 461 of each elastic attachment means 46 on the bearing surface 38 formed by the shoulder edge 37 provided on the support 3. Next, the optical element 4 is slid longitudinally, i.e. perpendicular to the plane defined by the support 3, along said bearing surface 38, it being understood that the shape of the base 5 is defined in such a way as not to impede this sliding movement.

(41) As the optical element 4 is being moved towards the support 3, the elastic blades 462, the original shape of which is inclined towards the center of the optical element 4, come into contact with the side edge of the support 3. The elastic blades 462 are configured to be elastically deformed towards the outside of the optical element 4 and allow the sliding movement to take place.

(42) Moreover, the sliding of the optical element 4 brings the indexing pin 45 arranged on the inner face 49 of the optical element 4 to face the indexing hole 34 provided in the support 3. This can result in an adjustment of the position of the optical element 4 relative to the support 3, in order to allow the indexing pin 45 to be inserted into the indexing hole 34, and then into the indexing ring 53 provided in the base 5 and arranged in the immediate continuation of the indexing hole 34. Therefore, the frame 461 of the elastic attachment means 46 and the indexing pin 45, and the bearing surface 38 formed by the shoulder edge 37 and the indexing hole 34, form means for positioning the optical element 4 on the support in a predefined position.

(43) When the sliding movement is complete, the optical element 4 is in contact with the support 3, or in the direct vicinity of same, it being understood that said parts are configured in such a way that the light sources 2 are not crushed by the optical element 4 in this desired position. In particular, the microlenses 42 are provided on the edge of the recess 43 and are slightly offset in a longitudinal direction relative to the inner face 49 of the optical element 4. As shown in FIG. 2, the optical element 4 can also be provided with beads 490 allowing the optical element 4 to be pressed against the support 3 without crushing the light sources 2.

(44) The cooperation of the positioning means, i.e. the positioning means 45 carried by the optical element 4 and the complementary positioning means carried by the support 3, in particular, makes it possible to obtain a predefined position, in which the through-bore 47 arranged in the attachment portion 66 of the optical element 4 is positioned in front of the central bore 35 of the support and the central threaded bore 54 of the base 5. These three bores 54, 35 and 47 are therefore aligned and configured to receive a first attachment means 6, it being understood that the through-bore 47 of the optical element 4 has a larger diameter than that of the central threaded bore 54 of the base 5.

(45) In the predefined position, the elastic blades 462 extend beyond the panel forming the support 3 and are no longer in contact with a side edge of said panel. They therefore return to their original shape, tending to move closer together towards the center of the optical element 4. The free end of each elastic blade 462 thus moves into position behind the panel forming the support 3, opposite the second face 391. The support 3 then forms a stop preventing the release of the elastic blades 462 and therefore the release of the optical element 4. If the optical element 4 needs to be replaced, the elastic blades 462 can be pushed apart with a certain force in order to release them from the support 3. During operation, without external intervention by an operator, the positioning of the optical element 4 relative to the support 3 and, therefore, the positioning of the microlenses 42 relative to the light sources 2, is reliable.

(46) Finally, the first attachment means 6 are used to hold the optical element 4, the support 3 and the base 5 together. In the example shown, the first attachment means 6 is an attachment screw, the head of the attachment screw being on the optical element 4 side.

(47) The optical element 4 is then attached relative to the support 3 at three points, and it can be seen that the center of these three points is positioned substantially in the vicinity of the microlenses 42, ensuring the reliable positioning of the microlenses 42 relative to the light sources 2, regardless of manufacturing tolerances.

(48) The method of assembling the light module 1 according to the invention described below is no more than an example of assembly. It is in no way limiting and it would, in particular, be quite possible to first assemble the optical element 4 on the support 3, and then assemble this sub-assembly on the heat conduction member 8 and its base 5.

(49) The light module 1 formed in this way can then be mounted on a housing or a plate of a lighting device via a second attachment means 7, in particular an attachment screw that cooperates with the attachment hole 59 provided in the base 5.

(50) FIG. 4 illustrates a lighting device 10 comprising several light modules 1 according to the invention and, in particular, as has just been described, consisting of a heat conduction member 8, a support 3 and an optical element 4 forming a sub-assembly that can be produced individually and then attached to the housing or plate of the lighting device.

(51) Each light module 1 according to the invention is attached to a plate 102 by a second attachment means 7. In the example shown, the light modules 1 are arranged on an axial end of the plate 102 and are carried by a vertical wall 110 of the plate 102, which also carries, on the opposite face, a heat sink 9, in this case a finned heat sink.

(52) The device moreover comprises a lens 104, arranged at an axial end of the plate 102 opposite that where the light modules 1 are arranged. In this way, an optical system is formed comprising a primary optical element 41 formed by the microlenses 42 in the direct vicinity of the light sources 2 and a secondary optical element 104, each of these optical elements being configured to contribute to the formation of a motor vehicle lighting and/or signaling beam from the light rays initially emitted by the light sources 2.

(53) In particular, it can be seen in FIG. 4 that some of the light modules 1 comprise a different number of light sources 2 and associated microlenses 42. FIG. 5 therefore shows a second embodiment of the light module that differs from the first previously described embodiment in that the support 3 comprises seven light sources 2, the optical element 4 correspondingly comprising seven microlenses 42 forming the primary optical element 41.

(54) As a result, the support 3 is wider at the portion 64 for treating the light rays in order to accommodate the series of light sources 2. The other features and elements of the light module 1 in this second embodiment are identical or essentially identical to those disclosed in the description of the first embodiment.

(55) The embodiments described above are in no way limiting; in particular, it is possible to envisage variants of the invention that only comprise a selection of the features described below in isolation from the other described features, if said selection of features is sufficient to give the invention a technical advantage over or distinguish it from the prior art.