Lighting device for vehicles

Abstract

Lighting device for vehicles with a light source unit (1) containing a number of light sources (2), with an optical unit (3) arranged in front of the light source unit (1) in the main radiation direction (H) and containing a number of optical elements (4, 5, 8) for imaging the light source (2) according to a predetermined light distribution (6), with an additional element (12) containing a release (13) for the light source (2), characterized in that - that the additional element is designed as an adjustment diaphragm (12) and the release as a diaphragm opening (13), wherein the adjustment diaphragm (12) runs in a diaphragm plane (B) extending perpendicular to an optical axis (A) of the optical unit (3) between a light entry surface (11) of the optical unit (3) and a light source plane (L) receiving the light source (2), - that the light source (2) has a contour running in the light source plane (L) with light source edges (14, 15, 16) which delimit a light-emitting surface (22) of the light source (2), - that the aperture (13) is arranged at a focal point of the optical unit (3), wherein the aperture (13) has a number of aperture edges (17, 18, 19) delimiting the aperture, and wherein a aperture edge designed as a preferred aperture edge (18) serves to image a light / dark boundary (7) of the light distribution, - that the light source (2) is arranged in the light source plane (L) in such a way that a lower longitudinal edge (15) of the light source (2) in a vertical projection onto the aperture (13) intersects a lower aperture edge (18) of the aperture (13) or converges with the same.

Description

[0001] The invention relates to a lighting device for vehicles with a light source unit containing a number of light sources, with an optical unit arranged in front of the light source unit in the main radiation direction and containing a number of optical elements for imaging the light source according to a predetermined light distribution, with an additional element containing a release for the light source.

[0002] DE 10 2013 107 355 A1 discloses a lighting device for vehicles comprising a light source unit and an optical unit arranged in front of the same in the main radiation direction for generating a predetermined light distribution. The light source unit comprises LED light sources as light sources, which are positioned on a light input side of the optical unit. The LED light sources are located in an object plane for the light distribution to be generated, wherein a contour of the rectangular light source is imaged by means of upstream optical elements of the optical unit. The light sources are each located at a focal point of the upstream optical element. When assembling the lighting device, the problem arises that the LED light source must be arranged precisely at the focal point of the upstream optical element. If the light source is not arranged precisely at the focal point of the optical element, the light image of the light source changes.The light distribution is massively affected. It is therefore important to adjust the light source precisely.

[0003] To adjust a light source with respect to an upstream optical unit, it is known from EP 2 327 926 A1 to arrange an additional element between a circuit board carrying the light source and an optical element of the optical unit. This additional element has fastening means so that the light source is arranged in a defined relative position to the optical element. For this purpose, the additional element has spring elements that engage the circuit board of the light source on the one hand and the carrier of the optical element on the other. The light source is arranged in a recess of the additional element, specifically at the focal point of the upstream optical element. Although the known additional element enables the compensation of tolerance deviations during the production of the components carrying the optical element and the light source, the manufacturing effort required to provide the additional element is relatively high.

[0004] It is therefore an object of the present invention to further develop a lighting device for vehicles in such a way that an adjustment of light sources to an optical unit can be simplified in a cost-effective manner.

[0005] To achieve this object, the invention in conjunction with the preamble of claim 1 is characterized in that the additional element is designed as an adjustment diaphragm and the release as a diaphragm opening, wherein the adjustment diaphragm runs in a diaphragm plane running perpendicular to an optical axis of the optical unit between a light entry surface of the optical unit and a light source plane receiving the light source, that the light source has a contour running in the light source plane with light source edges that delimit a light-emitting surface of the light source, that the diaphragm opening is arranged in a focal point of the optical unit, wherein the diaphragm opening has a number of diaphragm edges delimiting the same and wherein a diaphragm edge designed as a preferred diaphragm edge serves to image a light / dark boundary of the light distribution, that the light source is arranged in the light source plane in such a way thatthat a lower longitudinal edge of the light source, in a vertical projection onto the aperture, intersects or converges with a lower aperture edge of the aperture.

[0006] The particular advantage of the invention is that the adjustment effort can be reduced, particularly during manufacture of the lighting device. The costs for the additional element serving as an adjustment diaphragm, which runs as a diaphragm in a plane between a light source plane and a light entry plane of an optical unit, are relatively low. The adjustment diaphragm is arranged with its diaphragm opening in a defined position, namely at a focal point of the optical unit, wherein a preferred diaphragm edge of the adjustment diaphragm is imaged by the optical unit to form a light / dark boundary of the generated light distribution. The basic idea of ​​the invention is therefore that a preferred diaphragm edge of the adjustment diaphragm is used to image the light / dark boundary, not a light source edge.The light source can thus, for example, be tilted or rotated around an optical axis of the optical unit without changing the position of the light / dark boundary. Only a change in the light intensity in the light distribution is accepted. The position of the light / dark boundary is not affected. Advantageously, the lighting device can be manufactured with tolerances insensitive to the relative position of the light source to the optical unit, without the need for subsequent readjustment.

[0007] According to a further development of the invention, the adjustment diaphragm, as a diaphragm layer, is integrally bonded to the optical element of the optical unit on a side of an optical element facing the light source. Advantageously, the application of the diaphragm layer allows the preferred diaphragm edge to be precisely applied during production. The preferred diaphragm edge is precisely matched to an optical element of the illumination optics. The diaphragm layer or the fixation of the preferred diaphragm edge defines the light / dark boundary in the light distribution to be imaged. Even if the light source is not optimally aligned with the diaphragm opening created by the diaphragm layer, the light / dark boundary is always sharply imaged. This advantageously allows for the definition of the light / dark boundaries to be tolerance-insensitive. The adjustment effort can be reduced.If the light source is not optimally adjusted, this only affects the light intensity distribution in the light distribution, but not the light / dark boundary position.

[0008] According to a further development of the invention, the aperture layer is produced by vapor deposition or painting. The aperture layer is thus relatively thin, so that no additional space is required.

[0009] According to a further development of the invention, the contour of the aperture is adapted to the contour of the light source, with the preferred aperture always being a straight line or a straight line with a 15° slope in the case of an asymmetric low-beam distribution. The aperture is always larger than a light-emitting surface of the light source, so that the largest possible proportion of the luminous flux emitted by the light source can be transmitted.

[0010] According to a further development of the invention, the optical element of the optical unit has a collimating lens section and, on a side facing the light source, an axial extension section, wherein the extension section has a light entry surface. The light entry surface is provided with the diaphragm layer. The provision of an axial extension section advantageously creates thermal buffering or decoupling of the light source from the temperature-sensitive collimating lens section. The axial extension section is preferably formed from a material that is thermally insulating compared to the collimating section.

[0011] According to a further development of the invention, the collimating lens section of the optical element is made of a plastic material, and the axial extension section is made of a thermally insulating plastic material. For example, the axial extension section can be made of a silicone material, thus creating thermal decoupling between the light source and the collimating lens section, which is made of, for example, a polycarbonate.

[0012] According to a further development of the invention, the collimating lens section and the axial extension section can be made of a glass material and integrally connected to one another. This advantageously simplifies manufacturing.

[0013] According to a further development of the invention, the optical unit comprises a microlens array with a plurality of fixed microlenses. For example, the microlenses can have a cylindrical outer surface for horizontally deflecting the light. Another outer surface of the microlenses can have prismatic surfaces, thus ensuring vertical deflection of the light. The light collected by the collimating lens section can thus be expanded in the vertical and horizontal directions according to the predetermined light distribution.

[0014] An embodiment of the invention is explained in more detail below with reference to the drawings.

[0015] They show: Fig. 1 a schematic plan view of a lighting device, Fig. 2 a section of a rear view of an optical element provided with an adjustment diaphragm with a diaphragm opening and Fig. 3 a schematic representation of a light distribution with a light / dark boundary.

[0016] A lighting device for vehicles according to the invention is preferably designed as a headlight which is installed in a front area of ​​a motor vehicle.

[0017] The lighting device comprises a light source unit 1 with a plurality of light sources 2. The light sources 2 are designed as LED light sources, which are mounted as light source chips on a circuit board (not shown).

[0018] An optical unit 3 is arranged in front of the light source unit 1 in the main emission direction H, which essentially consists of an illumination optical unit 4 and a projection optical unit 5. The illumination optical unit 4 serves to parallelize the light emitted by light sources 2. The projection optical unit 5 is designed such that the light coming from the illumination optical unit 4 is deflected according to the predetermined light distribution. In the present exemplary embodiment, the projection optical unit 5 is designed such that a symmetrical low beam distribution 6 corresponding to Fig. 3 is generated with a light / dark boundary 7.

[0019] In the present exemplary embodiment, the illumination optics 4 has a number of optical elements 8, each assigned to the light sources 2, which are each assigned to a light source 2. The optical elements 8 each have a collimating lens section 9 for parallelizing the light and an axial extension section 10 arranged behind the collimating lens section 9 in the main emission direction H. The axial extension section 10 has a light entry surface 11 for the light emitted by the light sources 2. The light entry surface 11 of the optical element 8 is thus arranged on a side of the optical element 8 facing the light source 2. In the present exemplary embodiment, the light entry surface 11 is flat.

[0020] The optical element 8 is provided with an adjustment aperture 12 on its light entry side. The adjustment aperture 12 serves as an additional element to the optical element 8 and has a diaphragm opening 13 as a release, which serves as a passage or passage for the light emitted by the respective light source 2. The adjustment aperture 12 extends in an aperture plane B, which runs adjacent to the light entry surface 11 of the optical element 8. The diaphragm opening 13 of the adjustment aperture 12 is arranged at a focal point of the optical element 8 or the collimation lens section 9.

[0021] Preferably, the adjustment aperture 12 is formed as an aperture layer that is integrally bonded to the light entry surface 11 of the optical element 8. For example, the aperture layer 12 can be applied to the light entry surface 11 of the optical element 8 by vapor deposition or painting. If the aperture layer 12 is applied by vapor deposition, it can have a thickness in the range of 60 nm to 120 nm, for example. If the aperture layer 12 is applied to the light entry surface 11 by painting, for example, it can have a layer thickness in the range of 50 µm to 1 mm.

[0022] The light source 2 extends in a light source plane L, which runs parallel to the aperture plane B. The aperture plane B extends between the light source plane L and the light entry surface 11. The light entry surface 11 is also flat. The light source 2 is thus arranged in the main emission direction H behind the aperture 13, i.e., in the direction of an optical axis A of the optical element 8, offset from the adjustment aperture 12 or the aperture 13.

[0023] The aperture 13 of the adjustment aperture 12 is designed to be adapted in its contour to the contour of the light source 2. In the present embodiment, the light source 2 has a rectangular contour with an upper longitudinal edge 14 and a lower longitudinal edge 15 and the two connecting narrow sides 16. The aperture 13 has an upper aperture edge 17, a lower aperture edge 18 and the same connecting narrow sides 19. As can be seen from Fig. 2, the dimension of the aperture 13 is larger than the dimension of the light source 2 or its light-emitting surface 22.

[0024] The lower diaphragm edge 18 serves as the preferred diaphragm edge, which is imaged by the optical unit 3 to the light / dark boundary 7 of the low-beam distribution 6. The collimation lens section 9 is designed such that the light passing through the diaphragm opening 13 is parallelized. The projection optics 5 effects a corresponding image of this rectangular light spot onto a corresponding measuring screen arranged at a predetermined distance from the vehicle.

[0025] Even if the lower longitudinal edge 15 of the light source 2 does not run horizontally, but is slightly tilted to the side or pivoted about the optical axis A of the optical element 8, wherein the lower longitudinal edge 15 encloses an acute angle φ to a horizontal plane 20, a sharp image of the light / dark boundary 7 in a horizontal H1 of the light distribution 6 is produced, since the optical unit 3 does not image the contour of the light source 2, but rather the contour of the aperture 13, wherein the preferred aperture edge 18 is imaged to the light / dark boundary 7.

[0026] This advantageously creates a sharp light / dark boundary 7 with a predetermined profile, even if the light source 2 is not optimally aligned with the collimation lens section 9. Light intensity losses only occur because a partial area 21 of the light-emitting surface 22 of the light source 2 is covered by the adjustment aperture 12 and thus cannot enter the optical unit 3 or the optical element 9, in Fig. 2 drawn hatched.

[0027] When mounting the light source 2, it must be ensured that the lower longitudinal edge 15 of the light source 2 intersects the lower aperture edge 18 of the aperture 13 or converges with it. If the light-emitting surface 22 of the light source 2, which is smaller in dimension than the aperture 13, were to be arranged within the aperture 13, a tilted arrangement of the light source 2, as shown in Fig.2, can lead to an undesirable tilted arrangement of the light / dark boundary 7.

[0028] According to an alternative embodiment of the invention (not shown), a height h B the aperture 13 shall be designed to a height h Lof the light source 2, so that there is no need to align the lower longitudinal edge 15 of the light source 2 with the preferred aperture edge 18 of the adjustment aperture 12. The disadvantage of this, however, is that due to a possible tilting of the light source 2, the upper longitudinal edge 14 of the light source 2 also intersects the upper aperture edge 17 of the aperture 13, resulting in an increased loss of light intensity. This embodiment of the invention, not shown, is therefore preferably provided for relatively bright light sources 2. In the present exemplary embodiment, the upper longitudinal edge 14 of the light source 2 does not intersect the upper aperture edge 17 of the adjustment aperture 12. The narrow sides 16 of the light sources 2 also do not intersect the narrow sides 19 of the adjustment aperture 12. Ideally, only the lower longitudinal edge 15 of the light source 2 intersects the lower aperture edge 18 of the aperture 12 or converges with it.

[0029] In the present embodiment, the collimating lens section 9 is made of a first plastic material. The axial extension section 10 is made of a second plastic material, which acts as a thermal insulator for the collimating lens section 9. The heat radiated by the light source 2 thus does not impair the collimating lens section 9. In the present embodiment, the collimating lens section 9 is made of a polycarbonate, and the axial extension section 10 is made of a silicone material.

[0030] According to an alternative embodiment of the invention not shown, the collimating lens section 9 and the axial extension section 10 can also consist of a glass material and be connected to one another in one piece.

[0031] According to a further embodiment of the invention, the optical element 8 can also consist only of the collimating lens section 9 consisting of the glass material, wherein the adjustment aperture 12 is applied to a light entry surface of the collimating lens section 9.

[0032] The projection optics 5 has a first microlens array 24 and a second microlens array 26 with a plurality of fixed microlenses 25, 27. The microlens array 24 arranged downstream of the light flux has prisms 25 for vertically deflecting the light. The microlens array 26 arranged upstream of the light flux has cylindrical microlenses 27 for horizontally deflecting the light. The first microlens array 24 is arranged on a first outer surface of the projection optics 5, wherein the first outer surface forms a front side of the projection optics 5, i.e., the front in the main emission direction H. The second microlens array 26 is arranged on a second outer surface of the projection optics 5, which is arranged on the rear side, i.e., the rear side in the main emission direction H, on a rear side of the projection optics 5. The first microlens array 24 is integrally connected to the second microlens array 26.

[0033] The first projection optics 5 or the first microlens field 24 and the second microlens field 26 cover, in projection to the optical axis A, the illumination optics 4, which in the present embodiment is formed by three optical elements 8 arranged next to one another. List of reference symbols 1 light source unit 2 light sources 3 Optical unit 4 Lighting optics 5 Projection optics 6 Low beam distribution 7 Light / dark boundary 8 Optical element 9 Collimating lens section 10 axial extension section 11 Light entry surface 12 Adjustment aperture 13 aperture 14 upper longitudinal edge 15 lower longitudinal edge 16 narrow sides 17 upper panel edge 18 lower panel edge 19 narrow sides 20 horizontal plane 21 sub-area 22 light-emitting surface 23 24 Microlens field 25 microlenses h B , h L Height H Main radiation direction A optical axis B Blend plane L Light source plane H1 Horizontal

Claims

[1] Lighting device for vehicles with a light source unit (1) containing a number of light sources (2), with an optical unit (3) arranged in front of the light source unit (1) in the main radiation direction (H) and containing a number of optical elements (4, 5, 8) for imaging the light source (2) according to a predetermined light distribution (6), with an additional element (12) containing a release (13) for the light source (2), characterized by , - that the additional element is designed as an adjustment diaphragm (12) and the release as a diaphragm opening (13), wherein the adjustment diaphragm (12) runs in a diaphragm plane (B) extending perpendicular to an optical axis (A) of the optical unit (3) between a light entry surface (11) of the optical unit (3) and a light source plane (L) receiving the light source (2), - that the light source (2) has a contour running in the light source plane (L) with light source edges (14, 15, 16) which delimit a light-emitting surface (22) of the light source (2), - that the aperture (13) is arranged at a focal point of the optical unit (3), wherein the aperture (13) has a number of aperture edges (17, 18, 19) delimiting the aperture, and wherein a aperture edge designed as a preferred aperture edge (18) serves to image a light / dark boundary (7) of the light distribution, - that the light source (2) is arranged in the light source plane (L) in such a way that a lower longitudinal edge (15) of the light source (2) in a vertical projection onto the aperture (13) intersects a lower aperture edge (18) of the aperture (13) or converges with the same. [2] Lighting device according to claim 1, characterized bythat the adjustment aperture (12) is integrally connected as an aperture layer to a light entry surface (11) of an optical element (8) of the optical unit (3) facing the light source (2). [3] Lighting device according to claim 1 or 2, characterized by that the diaphragm layer is applied to the light entry surface (11) of the optical element (8) by vapor deposition or painting, wherein the diaphragm opening (13) is left out. [4] Lighting device according to one of claims 1 to 3, characterized by that the aperture (13) of the adjustment aperture (12) is adapted to the contour of the light source (2), wherein an area of ​​the aperture (13) is larger than the light-emitting area (22) of the light source (2). [5] Lighting device according to one of claims 1 to 4, characterized bythat the optical element (8) has a collimating lens section (9) and, on a side facing the light source (2), an axial extension section (10) having the light entry surface (11). [6] Lighting device according to one of claims 1 to 5, characterized by that the collimating lens section (9) is made of a plastic material and the axial extension section (10) is made of a thermally insulating plastic material. [7] Lighting device according to one of claims 1 to 5, characterized by that the collimating lens section (9) and the axial extension section (10) consist of a glass material which are integrally connected to one another. [8] Lighting device according to one of claims 5 to 7, characterized bythat the optical unit (3) has a projection optics (5) arranged in the main emission direction (H) in front of the collimation lens section (9) with a microlens field (24, 26) containing a plurality of fixed microlenses (25, 27). [9] Lighting device according to claim 8, characterized by that the projection optics (5) has on a first outer surface a first microlens field (24) with prism-shaped microlenses (25) for vertical deflection of the light and on a second outer surface a second microlens field (26) with cylindrical microlenses (27) for horizontal deflection of the light. [10] Lighting device according to one of claims 1 to 9, characterized by that the light source unit (1) has a plurality of light sources (2), each of which is assigned an optical element (8) provided with a collimating lens section (9).

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