Headlights for a motor vehicle

Abstract

Headlights for a motor vehicle, comprising a plurality of light sources (1) from which light (17) is emitted during operation of the lighting device, wherein the light sources (1) are arranged side by side in a first direction (X), a collimation optic (2) with a plurality of collimation lenses (4), each having an inlet surface (5) and an outlet surface (6), wherein the collimation lenses (4) are arranged side by side in the first direction (X), a secondary optic (2) comprising at least one transparent substrate (8) with an inlet surface (9) and an outlet surface (10), wherein two sections arranged side by side in the first direction (X) are provided on the at least one substrate (8), wherein an array (11) of cylindrical lenses (12) is arranged in a first of the sections and wherein no array (11) of cylindrical lenses (12) is arranged in a second of the sections, wherein the lighting device is configured tothat the light (17) emanating from one of the light sources (1) passes successively through the entrance surface (5) and the exit surface (6) of one of the collimating lenses (4) and subsequently through one of the sections of the secondary optics (2), wherein in the second section an array (13) of refractive structures (14) is arranged, each having a prism (15) on the entrance surface (9) and a prism (16) on the exit surface (10) of the at least one substrate (8), wherein the refractive structures (14) are configured such that light (17) emanating from the collimating optics (2) passes successively through the two prisms (15, 16) of one of the refractive structures (14).

Description

[0001] The present invention relates to a headlight for a motor vehicle according to the preamble of claim 1.

[0002] A headlight of the aforementioned type is known from DE 10 2021 122 953 B3. The headlight described therein comprises a plurality of light sources from which light emanates during operation of the lighting device, a collimating optical system with a plurality of collimating lenses, each having an entrance surface and an exit surface through which the light emanating from the light sources passes, and a secondary optical system with a transparent substrate on which a plurality of arrays of cylindrical lenses are arranged, wherein the light emanating from the collimating optical system passes through the arrays of cylindrical lenses, wherein the collimating lenses are arranged in at least two rows, wherein in each of the rows at least two of the collimating lenses are arranged next to one another in a first direction and wherein the rows are arranged next to one another in a second direction, preferably perpendicular to the first direction.In this case, only one array of cylindrical lenses on the entrance surface is assigned to a first row of collimating lenses, and a first array of cylindrical lenses on the entrance surface and a second array of cylindrical lenses on the exit surface are assigned to a second row of collimating lenses.

[0003] A disadvantage is that, in this embodiment of the headlight, the exit surface of the secondary optics visible from the road has sections with cylindrical lenses and sections without cylindrical lenses, with the sections without cylindrical lenses being flat and without any structuring. Thus, structured sections and adjacent unstructured sections are visible from the road, which impairs the appearance of the headlight. If the unstructured sections of the exit surface are also assigned sections of the entrance surface without cylindrical lens arrays, the collimation lens arranged behind these unstructured sections is visible from the road, which further impairs the appearance of the headlight.

[0004] The problem underlying the present invention is to provide a headlight of the type mentioned at the outset, the external appearance of which is not impaired by unstructured sections of the exit surface of the transparent substrate.

[0005] This is achieved according to the invention by a headlight of the type mentioned above with the characterizing features of claim 1. The subclaims relate to preferred embodiments of the invention.

[0006] According to claim 1, an array of refractive structures is arranged in the second section, each having a prism on the entrance surface and a prism on the exit surface of the at least one substrate, wherein the refractive structures are configured so that light emanating from the collimation optics passes successively through the two prisms of one of the refractive structures. Due to the prisms on the section of the exit surface of the transparent substrate not provided with an array of cylindrical lenses, the exit surface appears comparatively homogeneous when viewed from the street. Furthermore, the collimation lens arranged behind the section not provided with an array of cylindrical lenses can be at least partially concealed by the refractive structures.

[0007] The refractive structures can be designed to not change, or only slightly change, the degree of collimation of the light emitted by the collimation optics. Thus, the intended light function is not impaired, or only slightly impaired, by the refractive structures.

[0008] It is possible for each of the prisms to extend in the first direction over at least part of the second section without changing its cross-section, in particular wherein each of the prisms extends in the first direction over the entire second section without changing its cross-section. As a result, the entire extent of the section not provided with an array of cylindrical lenses in the first direction may be provided with a structure that has a similar appearance to the section provided with an array of cylindrical lenses.

[0009] It can be provided that the refractive structures are arranged next to one another in a second direction that is perpendicular to the first direction, in particular wherein the refractive structures are arranged periodically in the second direction such that the extent of the structures in the second direction and the distances between adjacent structures in the second direction are the same for several, preferably for all, refractive structures. As a result, under certain circumstances, the entire extent of the section not provided with an array of cylindrical lenses in the second direction is also provided with a structuring that has a similar appearance to the section provided with an array of cylindrical lenses.

[0010] The first direction can correspond to a horizontal direction when the headlight is installed in the vehicle and the second direction can correspond to the vertical direction when the headlight is installed in the vehicle.

[0011] It is possible for the cylindrical lenses of the array of cylindrical lenses to be arranged side by side in the first direction, while the cylindrical axes of the cylindrical lenses extend in the second direction. This vertical arrangement of the cylinder axes achieves a horizontal spreading of the light passing through the substrate.

[0012] It can be provided that, in each of the refractive structures, the prism on the entrance surface of the substrate is offset from the prism on the exit surface of the substrate, in particular offset in the second direction. The refractive structures can be configured such that the light emanating from the collimation optics undergoes a beam offset by the prisms of the refractive structures, in particular a beam offset in the second direction. Such a beam offset does not affect the collimation state of the light passing through the substrate.

[0013] It is possible for the refractive structures to be configured so that the light emitted by the collimating optics, which strikes a prism on the substrate's entrance surface, exits exclusively through the prism on the substrate's exit surface, which is enclosed by the same refractive structure. This ensures that the light entering the substrate through the prism on the entrance surface is not scattered at the transition areas between neighboring prisms.

[0014] It can be provided that, for each of the refractive structures, the cross-section of the prism on the entrance surface of the substrate is point-symmetric to the cross-section of the prism on the exit surface of the substrate. This ensures that the change in direction that the light undergoes through the prism on the entrance surface is reversed by the prism on the exit surface, so that the light passing through the substrate only experiences a beam offset but no change in direction.

[0015] It is possible for the edges of the prisms of the refractive structures to be rounded. These rounded edges prove advantageous for the production of the substrates containing the prisms, for example, when the substrates are plastic injection-molded parts. However, the radii of the rounded edges should be comparatively small to avoid glare.

[0016] It can be provided that the secondary optics has a transparent substrate on which both the first section with the array of cylindrical lenses and the second section with the refractive structures are arranged.

[0017] Alternatively, it can be provided that the secondary optics has at least two transparent substrates, wherein the first section with the array of cylindrical lenses is arranged on a first of the transparent substrates and wherein the second section with the refractive structures is arranged on a second of the transparent substrates.

[0018] It is possible for the secondary optics to have a plurality of first sections, each with an array of cylindrical lenses. Alternatively or additionally, the secondary optics can also have a plurality of second sections, each with an array of refractive structures.

[0019] It can be provided that one of the collimating lenses and a first section with an array of cylindrical lenses or a second section with an array of refractive structures are assigned to each of the light sources in such a way that the light emanating from the light source passes successively through the assigned collimating lens and the assigned array of cylindrical lenses or through the assigned array of refractive structures. With such a design, the array of refractive structures can preferably completely conceal the assigned collimating lens.

[0020] The invention is explained in more detail below with reference to the accompanying drawings. In the drawings: Fig. 1 is a schematic side view of a headlight according to the invention; Fig. 2 a front view of the headlight according to Fig. 1, wherein in the front view the refractive structures in the second section of the transparent substrate are not shown in order to allow a view of the collimating lens arranged behind it; Fig. 3 a sectional view of a substrate of the secondary optics of the headlight according to Fig. 1 with schematically indicated beam path of the light passing through the secondary optics.

[0021] In the figures, identical or functionally equivalent parts are provided with the same reference symbols. A Cartesian coordinate system is shown in some figures for better orientation.

[0022] The headlight shown in the figures comprises a plurality of light sources 1, a collimation optic 2 and a secondary optic 3 (see Fig. 1). In Fig. 1 only shows one of the light sources 1.

[0023] The light sources 1 are designed as light-emitting diodes (LEDs), which emit light during operation of the headlight. The LEDs can, in particular, be arranged on a common circuit board. For example, the illustrated embodiment of the headlight can have a row of spaced-apart LEDs. However, it is certainly possible to provide more than one row, such as two rows or three rows of spaced-apart LEDs.

[0024] The light sources 1 are arranged next to one another and spaced apart from one another in a first direction X. If multiple rows are provided, the rows of light sources are arranged next to one another and spaced apart from one another in a second direction Y perpendicular to the first direction X. A sufficient spacing between the LEDs can be thermally advantageous or result in effective heat dissipation of the headlight.

[0025] In particular, the first direction X corresponds to a horizontal direction when the headlight is installed in the vehicle, whereas the second direction Y corresponds to a vertical direction when the headlight is installed in the vehicle. A third direction Z, perpendicular to the first and second directions X, Y, essentially corresponds to the mean propagation direction of the light emanating from the light sources 1.

[0026] The Fig. The embodiment of the collimating optics 2, which is only schematically illustrated in FIG. 1, is formed in one piece and configured so that the light emitted by the light sources 1 passes at least partially through the collimating optics 2 during operation of the lighting device. In the illustrated embodiment, the collimating optics 2 has only one row of three collimating lenses 4 arranged side by side in the first direction X.

[0027] If more than one row of light sources 1 is provided, the collimation optics 2 also has more than one row of collimation lenses 4. The rows of collimation lenses 4 are in this case arranged like the light sources 1 in the second direction Y or in Fig. 1 arranged one below the other.

[0028] It is certainly possible to provide more than three or fewer than three collimating lenses 4 per row.

[0029] The collimating lenses 4 each have an entrance surface 5 facing the light sources 1 and an exit surface 6 opposite the entrance surface 5 (see Fig. 1). Each of the light sources 1 is assigned a collimating lens 4 and arranged in front of the light source 1 in such a way that the light emitted by the light sources 1 is largely collimated by the respectively assigned collimating lens 4.

[0030] It is certainly possible to form the collimation lenses 4 of the collimation optics 2 not as a single piece, but rather on separate substrates, wherein the substrates can be arranged next to one another in the first and / or second directions X, Y. This can result in a column-by-column division or a row-by-row division of the collimation optics 2 into several substrates.

[0031] On the entrance surfaces 5 of the collimating lenses 4, an aperture 7 is arranged between each of the light sources 1 and the associated collimating lens 4 (see Fig. 1). The aperture 7 is formed as an opening in an opaque layer on the entrance surface 5. This opaque layer can be applied to the entrance surface 5, in particular by vapor deposition or painting, whereby the opening can be introduced into the layer by exposure to laser radiation.

[0032] It is certainly possible to design the aperture 7 not as an opening arranged on the entrance surface 5, but as a separate part between the light source 1 and the entrance surface 5.

[0033] The lower edge of one, several or each of the apertures 7 on the entrance surfaces 5 of the collimating lenses 4 (see Fig. 1) can be projected into the exterior of the motor vehicle by the headlight optics formed by the collimation optics 3 and the secondary optics 3 as a horizontal light-dark boundary.

[0034] The secondary optics 3 comprises three transparent substrates 8. It is possible for the secondary optics 3 to comprise fewer or more than three transparent substrates 8. For example, the secondary optics 3 may comprise only one transparent substrate 8. In the Fig. In the embodiment shown in Figure 2, the three transparent substrates 8 are arranged next to one another in the first direction X.

[0035] The transparent substrates 8 each have an entrance surface 9 facing the collimation optics 2 and an exit surface 10 opposite thereto. The two outer substrates 8 each form a first section of the secondary optics 3. Each of these first sections or each of the outer substrates 8 has an array 11 of cylindrical lenses 12 arranged next to one another in the first direction X (see Fig. 2). The cylinder axes of the cylindrical lenses 12 extend in the second direction Y.

[0036] It can be provided that the arrays 11 of cylindrical lenses 12 are arranged on the exit surface 10, and that the entrance surface 9 of the outer substrates 8 is flat. Alternatively, it is possible for arrays 11 of cylindrical lenses 12 to be arranged on both the entrance surface 9 and the exit surface 10.

[0037] During operation of the headlight, the light emanating from the collimation optics 2 passes at least partially through the arrays 11 of cylindrical lenses 12 and is expanded by them in the first direction X or in the horizontal direction.

[0038] The middle substrate 8 (see Fig. 2) forms a second section of the secondary optics 3. This second section has an array 13 of refractive structures 14, each of which has a prism 15 on the entrance surface 9 and a prism 16 on the exit surface 10 of the substrate 8 (see Fig. 3). Fig. 2, the array 13 of refractive structures 14 is omitted merely to clarify the arrangement of the collimation lens 4 assigned to this section.

[0039] In Fig. 3, only one of the refractive structures 14 is shown. The refractive structures 14 of the array 13 are arranged adjacent to one another in the second direction Y. The refractive structures 14 are arranged periodically in the second direction Y such that the extent of the structures 14 in the second direction Y and the distances between adjacent structures 14 in the second direction Y are the same for several, preferably for all, refractive structures 14.

[0040] In particular, it can be provided that the prisms 15, 16 of adjacent refractive structures are directly connected to one another.

[0041] Furthermore, each of the prisms 15, 16 extends in the first direction X or into the plane of the Fig. 3 into the second section without changing its cross-section.

[0042] In each of the refractive structures 14, the cross section of the prism 15 on the entrance surface 9 of the substrate 8 is point-symmetrical to the cross section of the prism 16 on the exit surface 10 of the substrate 8. The imaginary center of symmetry of this point symmetry lies in a plane located halfway between the entrance surface 9 and the exit surface 10. Furthermore, in each of the refractive structures 14, the prism 15 on the entrance surface 9 of the substrate 8 is offset from the prism 16 on the exit surface 10 of the substrate 8 in the second direction Y (see Fig. 3).

[0043] Fig. 3 shows that the light 17 emanating from the collimation optics 2 is directed downwards by the prism 15 on the entrance surface 9 of the substrate 8 into Fig. 3 is deflected. Due to the point-symmetrical design of the prisms 15, 16, the light 17 is deflected by the prism 16 on the exit surface 10 of the substrate 8 upwards again into Fig. 3 is deflected so that after passing through the substrate 8 it moves again in the same direction as before entering the substrate 8. The light 17 only experiences a slight beam offset.

[0044] By suitable selection of the thickness d of the substrate 8, the height offset h of the prism 15 on the entrance surface 9 of the substrate 8 to the prism 16 on the exit surface 10 of the substrate 8 and the height a of a prism 15, 16, it can be achieved that the degree of collimation of the light 17 emanating from the collimation optics 2 is not changed or is changed only insignificantly.

[0045] The prisms 15, 16 are designed such that the upper edge 15a of the prism 15 is flush with the entrance surface 9 and that the lower edge 16a of the prism 16 is flush with the exit surface 10.

[0046] The edges of the prisms 15, 16 of the refractive structures 14 may be rounded for manufacturing reasons. List of reference symbols 1 light source 2 Collimation optics 3 Secondary optics 4 Collimation lens 5 Entrance surface of the collimating lens 6 Exit surface of the collimating lens 7 aperture 8 Transparent substrate of the secondary optics 9 Entrance surface of the transparent substrate 10 Exit surface of the transparent substrate 11 Array of cylindrical lenses 12 Cylindrical lens of the array 13 Array of refractive structures 14 refractive structure of the array 15 Prism on the entrance surface of the transparent substrate 15a upper edge of the prism on the entrance surface 16 Prism on the exit surface of the transparent substrate 16a lower edge of the prism on the exit surface 17 Light emitted by the collimation optics d Thickness of the transparent substrate h Height offset of the prisms on the entrance surface and the exit surface a Height of the prism QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2021 122 953 B3

[0002]

Claims

[1] Headlight for a motor vehicle, comprising - a plurality of light sources (1) from which light (17) emanates during operation of the lighting device, wherein the light sources (1) are arranged next to one another in a first direction (X), - a collimation optic (2) with a plurality of collimation lenses (4), each having an entrance surface (5) and an exit surface (6), wherein the collimation lenses (4) are arranged next to one another in the first direction (X), - a secondary optic (2) comprising at least one transparent substrate (8) with an entrance surface (9) and an exit surface (10), wherein two sections arranged next to one another in the first direction (X) are provided on the at least one substrate (8), wherein an array (11) of cylindrical lenses (12) is arranged in a first of the sections and wherein no array (11) of cylindrical lenses (12) is arranged in a second of the sections, - wherein the illumination device is designed so that the light (17) emanating from one of the light sources (1) passes successively through the entrance surface (5) and the exit surface (6) of one of the collimating lenses (4) and then through one of the sections of the secondary optics (2), characterized by in that an array (13) of refractive structures (14) is arranged in the second section, each of which has a prism (15) on the entrance surface (9) and a prism (16) on the exit surface (10) of the at least one substrate (8), wherein the refractive structures (14) are designed so that light (17) emanating from the collimation optics (2) passes successively through the two prisms (15, 16) of one of the refractive structures (14). [2] Headlight according to claim 1, characterized bythat the refractive structures (14) are designed not to change, or to change only insignificantly, the degree of collimation of the light (17) emanating from the collimation optics (2). [3] Headlight according to one of claims 1 or 2, characterized by that each of the prisms (15, 16) extends in the first direction (X) over at least part of the second section without changing its cross-section, in particular wherein each of the prisms (15, 16) extends in the first direction (X) over the entire second section without changing its cross-section. [4] Headlight according to one of claims 1 to 3, characterized byin that the refractive structures (14) are arranged next to one another in a second direction (Y) which is perpendicular to the first direction (X), in particular wherein the refractive structures (14) are arranged periodically in the second direction (Y) such that the extent of the structures (14) in the second direction (Y) and the distances between adjacent structures (14) in the second direction (Y) are the same for several, preferably for all, refractive structures (14). [5] Headlight according to claim 4, characterized by that the first direction (X) corresponds to a horizontal direction when the headlight is installed in the vehicle and that the second direction (Y) corresponds to the vertical direction when the headlight is installed in the vehicle. [6] Headlight according to claim 5, characterized bythat the cylindrical lenses (12) of the array (11) of cylindrical lenses (12) are arranged next to one another in the first direction (X) and the cylinder axes of the cylindrical lenses (12) extend in the second direction (Y). [7] Headlight according to one of claims 1 to 6, characterized by that in each of the refractive structures (14) the prism (15) on the entrance surface (9) of the substrate (8) is offset from the prism (16) on the exit surface (10) of the substrate (8), in particular is offset in the second direction (Y). [8] Headlight according to claim 7, characterized by that the refractive structures (14) are designed so that the light (17) emanating from the collimation optics (2) undergoes a beam offset by the prisms (15, 16) of the refractive structures (14), in particular a beam offset in the second direction (Y). [9] Headlight according to one of claims 1 to 8, characterized bythat the refractive structures (14) are designed so that the light (17) emanating from the collimation optics (2), which impinges on a prism (15) on the entrance surface (9) of the substrate (8), exits exclusively through the prism (16) on the exit surface (10) of the substrate (8) encompassed by the same refractive structure (14). [10] Headlight according to one of claims 1 to 9, characterized by that in each of the refractive structures (14) the cross section of the prism (15) on the entrance surface (9) of the substrate (8) is point-symmetrical to the cross section of the prism (16) on the exit surface (10) of the substrate (8). [11] Headlight according to one of claims 1 to 10, characterized by that the edges (15a, 16a) of the prisms (15, 16) of the refractive structures (14) are rounded. [12] Headlight according to one of claims 1 to 11, characterized bythat the secondary optics (3) has a transparent substrate (8) on which both the first section with the array (11) of cylindrical lenses (12) and the second section with the refractive structures (14) are arranged. [13] Headlight according to one of claims 1 to 11, characterized by that the secondary optics (3) has at least two transparent substrates (8), wherein the first section with the array (11) of cylindrical lenses (12) is arranged on a first of the transparent substrates (8) and wherein the second section with the refractive structures (14) is arranged on a second of the transparent substrates (8). [14] Headlight according to one of claims 1 to 13, characterized by that the secondary optics (3) has a plurality of first sections, each with an array (11) of cylindrical lenses (12). [15] Headlight according to one of claims 1 to 14, characterized byin that one of the light sources (1) is assigned one of the collimating lenses (4) and a first section with an array (11) of cylindrical lenses (12) or a second section with an array (13) of refractive structures (14) in such a way that the light (17) emanating from the light source (1) passes successively through the assigned collimating lens (4) and the assigned array (11) of cylindrical lenses (12) or through the assigned array (13) of refractive structures (14).

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