EP3372890A1 - Motor vehicle headlamp light module - Google Patents

Abstract

Disclosed is a motor vehicle headlamp light module with a semiconductor light source and a projection lens which generates a light distribution in which an edge of the semiconductor light source is imaged as a cut-off line, wherein the projection lens has a first partial area which generates a first partial light distribution and has a second partial area, which generates a second partial light distribution which overlaps with the first partial light distribution. The light module is characterized in that the projection lens has a third partial area which generates a third partial light distribution which is delimited by the cut-off and which overlaps with the first partial light distribution and the second partial light distribution, wherein the first partial light distribution and the second partial light distribution lies below the light-dark boundary generated by the third partial area.

Description

The present invention relates to a motor vehicle headlight light module according to the preamble of claim 1. Such a light module is known from EP 3 043 109 A1 known. The known light module has a semiconductor light source and a projection lens which is arranged in a light bundle emanating from the semiconductor light source and which generates a light distribution from the light bundle in which an edge of a light exit surface of the semiconductor light source is imaged as a cut-off line. The projection lens has a first partial region which generates a first partial light distribution, and has a second partial region which generates a second partial light distribution which overlaps with the first partial light distribution. The first subarea is delimited from the second subarea by a pronounced bend in the light entry surface of the projection lens.

The known light module is an example of a direct imaging light module. Such light modules enable generation of light distributions with a minimum number of components. Usually, a direct imaging system consists of one or more light sources and a single projection optics, which is usually a projection lens.

The generation of a cut-off line with a direct imaging system is eg also from EP 1 447 617 2 known. There, the lower edge of an LED line is displayed as a cut-off line. Furthermore, from the patent US Pat. No. 7,648,262 B2 It is known to use a segmented lens to optimize light distribution. The optimized in this patent light distribution corresponds to a low beam with increase (asymmetric low beam). Segmentation of the lens surface for the benefit of color correction is not applied. From the EP 2 924 339 A1 is also known a direct imaging light module. Both at the EP 2 924 339 A1 as well as at the EP 3 043 109 A1 be generated with different portions of the projection lens partial light distributions, which have a color fringe at their edges. By suitable overlaying of a reddish color fringe of a partial light distribution with a bluish fringe of a different partial light distribution, the troublesome color fringe is eliminated.

Also known are light modules that create a light-dark boundary by the image of a shutter in the beam path.

The object of the invention is to provide a cost-effective and efficient A motor vehicle headlamp light module that generates a light distribution that has a cut-off line.

From the above-mentioned prior art, the present invention differs by the characterizing features of claim 1. These provide that the projection lens has a lying between the first portion and the second portion third portion, which is adapted to a third partial light distribution generate, which is limited at the intended use of the motor vehicle headlamp light module from the light-dark boundary generated as an image of the edge of the semiconductor light source overlapping and superimposed with the first partial light distribution and the second partial light distribution, wherein the first partial light distribution and the second partial light distribution below lie a line that is under normal use of the motor vehicle headlamp light module below the light-dark boundary generated by the central portion and a distance of a minimum of 0.5 ° to a maximum of 2 ° from this Hell-Dunke l limit has. Location information such as under or over in this application always refer to an arrangement as they result in a proper use of the motor vehicle headlamp light module.

By these features, a color space-compensated light distribution having a large vertical width and a high-contrast cut-off line is achieved with a simply constructed direct imaging system. The invention is based on the recognition that with the middle portion alone a partial light distribution with a high-contrast cut-off line and without disturbing color fringes. This light distribution has the property that it has only a small width in the direction transverse to the cut-off line, which is a vertical direction when the light module is used as intended. This is advantageous for the brightness at the cut-off line, but on the other hand means that the front end of the light module lying between the cut-off line and the vehicle into which the light module is installed is only insufficiently illuminated. This disadvantage is eliminated by the other two partial light distributions, which are generated with parts of the projection lens which are farther from the center of the lens and which are superimposed for illuminating the apron. In addition, these partial light distributions enhance the brightness in the lateral areas and in the core area of the total light distribution resulting from the superposition. Color fringes occurring at the edges of these partial light distributions are compensated for by superimposing a bluish fringe of color with a reddish fringe, so that overall, ie including the contribution of the white partial light distribution of the central partial region, a color-neutral light distribution appears. Above all, the partial light distributions of the two partial regions of the projection lens located farther away from the center of the lens are superimposed with the partial white distribution of the central partial region (ie no or at least no pronounced color fringe).

The light module according to the invention is particularly suitable for use as a cornering light module and / or static cornering light module or as a basic light module.

By suitable shaping of the lens surfaces, the light module according to the invention generates the cut-off line from the projection optics themselves. Compared to systems with a shutter, the number of components required is reduced. The implementation of the color correction by segmentation of the lens leads to an additional cost advantage over the known systems.

A preferred embodiment is characterized in that the first subregion and the second subregion lie on different sides of an optical axis of the projection lens.

It is also preferable for the first subarea to be above the optical axis when the light module is used as intended and the second subarea to be below the optical axis.

It is also preferable that the center of the third portion lies on the optical axis.

Furthermore, it is preferred that the three partial light distributions are equally wide in the horizontal direction when the light module is used as intended.

It is also preferable for the first partial light distribution and the second partial light distribution to be wider in the vertical direction than the third partial light distribution when the light module is used as intended.

A further preferred embodiment is characterized in that the projection lens is smooth in the region of its optical surfaces and has no steps.

It is also preferred that a light entry surface of the projection lens facing the semiconductor light source is subdivided horizontally into three subareas which merge without steps and without kinking. It is further preferred that the lens is integral with a frame serving as a lens holder.

Another preferred embodiment is characterized in that the lens and the frame are made of the same material.

It is also preferred that an end of the frame facing away from the lens in the direction of the optical axis is arranged for fastening a circuit board having a semiconductor light source and a cooling element.

Furthermore, it is preferred that the frame has form-locking structures which, together with complementary form-fitting structures of the circuit board and / or the cooling element, fix the position of the semiconductor light source relative to the projection lens in the direction of the optical axis and transverse to the optical axis.

A further preferred embodiment is characterized in that the semiconductor light source has at least two juxtaposed light exit surfaces, which are adjacent to one another in a direction transverse to the optical axis and along this direction are limited by aligned edges.

Further advantages will be apparent from the dependent claims, the description and the attached figures.

It is understood that the above and the hereinafter to be explained features not only in the particular combination given, but also in other combinations or alone, without departing from the scope of the present invention.

Figur 1

eine perspektivische Ansicht eines Basiselements eines Ausführungsbeispiels eines erfindungsgemäßen Lichtmoduls;

Figur 2

schematisch einen Vertikalschnitt durch ein Ausführungsbeispiel eines erfindungsgemäßen Lichtmoduls mit einem Basiselement gemäß Figur 1;

Figur 3

eine Draufsicht auf ein Beispiel einer Halbleiterlichtquelle;

Figur 4

Wendelbilddarstellungen des zentralen Teilbereichs der Projektionslinse; und

Figur 5

verschiedene Teillichtverteilungen und ihre Überlagerung zu einer Gesamtlichtverteilung eines erfindungsgemäßen Lichtmoduls.

Embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description. In this case, the same reference numerals in different figures denote the same or at least functionally comparable elements. In each case, in schematic form:

FIG. 1

a perspective view of a base member of an embodiment of a light module according to the invention;

FIG. 2

schematically a vertical section through an embodiment of a light module according to the invention with a base element according to FIG. 1 ;

FIG. 3

a plan view of an example of a semiconductor light source;

FIG. 4

Helical image representations of the central portion of the projection lens; and

FIG. 5

different partial light distributions and their superposition to a total light distribution of a light module according to the invention.

In the following description of individual figures, clearly recognizable features are also addressed in other figures, without any explicit reference being made to the respective other figure. FIG. 1 shows one Rear perspective view of a base member 10 of an embodiment of a motor vehicle headlamp light module 12 according to the invention, as shown in FIG FIG. 2 is shown in a vertical section. The x-direction indicates the main emission direction of the light module 12. The H direction indicates the direction of the horizontal direction perpendicular to the traveling direction in the intended use, and the V direction indicates the direction of the vertical for this case. The base element 10 is in one piece and preferably consists of a uniform material. The material is preferably a transparent plastic such as PVC or PMMA.

The base element 10 has a projection lens 14 and a frame 16 which is cohesively connected to the projection lens 14. The frame 16 has a first end 18 and a second end 20. The first end 18 is the material fit into the projection lens 14 merging part of the frame 16. Starting from this first end 18, the frame 16 extends into the light exit surface 22 (see FIG. 2 The base element 10 may be designed to be closed around the optical axis in the area of the frame 16, but for thermal reasons it will preferably have openings upwards and downwards.

The here oval optical surface of the projection lens 14 is extended in the illustrated embodiment to a rounded rectangular outer shape of the frame 16. The optical surface may also be round, for example circular. The resulting optically inactive regions 24 of the frame 16 fill the gap between the optically active lens surface and the frame 16 from. The semiconductor light source 28 is mounted on a board 29. The board 29 is fixed in thermal contact on or on a cooling plate 31, which is bolted to the base member 14 with screws 34. The resulting from the extension to the rectangular outer shape frame 16 also serves by the attached eyelets 32 as a fastener between the projection lens 14, board 29 and heat sink 31. The heat sink is an advantageous simple and inexpensive example of a cooling element. If necessary, a cooling element of more complex shape, for example, having cooling fins or cooling pins can be used.

At the second end 20 form-fitting structures are arranged. In the case shown, the positive locking structures are first contact surfaces 36 and reference pins 38. The circuit board 29 and / or a cooling plate 31 carrying the circuit board 29 (cf. FIG. 2 ) have complementary positive locking structures, ie recesses for the reference pins 38 and second contact surfaces for abutment against the first abutment surfaces 36 of the base member 10. The contact surfaces results in a precisely defined, with only minimal positional tolerances associated distance 26 of the projection lens 14 and semiconductor light source 28th The necessary for a good efficiency and short length short focal length of the projection lens 14 required high positioning accuracy of the semiconductor light source 28 and projection lens 14 is made possible in the present invention by the minimum number of components used. In addition, due to the small number of parts also results in a cost savings for material and assembly costs.

FIG. 3 shows a plan view of an example of a semiconductor light source 28. The illustrated semiconductor light source 28 is a horizontally oriented double chip. For automotive headlamp applications, the edges of a single chip 28.1, 28.2 are, for example, 0.3 mm to 1.5 mm long. The chips first emit blue light, which is converted to white light with the help of a yellow fluorescent layer, which rests on the chips, which has blue and yellow-red spectral components. The heat released in this semiconductor light source 28 is due to the cost-effective, no cooling fins having cooling plate 31 from the FIG. 2 derived. But it can also be used cooling fins having cooling fins instead of the cooling plate 31.

A focal point F of the projection lens 14 is preferably in the light exit surface of the semiconductor light source 28. Then, a horizontal edge 28.3 of the light exit surfaces of the semiconductor light source is imaged as a cut-off line. The horizontal edge 28.3 results from the fact that the light exit surfaces of the semiconductor light source are adjacent to one another in an H direction lying transversely to the optical axis and are delimited along this direction by aligned edges.

The board 29 or the circuit board 29 carrying the cooling plate 31 is aligned during assembly of the light module 12 by the interaction of the interlocking elements relative to the projection lens 14 and connected by additional fastening means fixed to the frame 16 of the base member 10. The fastening means are for example screws 40, for example, from the light exit side through recesses in the frame 16 of the base element 10 are screwed into the voltage applied to the contact surfaces or on the board 29 adjacent cooling plate 31. In this context, the cooling plate 31 preferably also serves as a cutting material for the screws 40, which hold the individual elements of the cooling plate 31, the plate 29 and the base element 10 together. If necessary. the attachment can be made against suitable pressure springs so that during assembly still a correct adjustment and locking can be made. The attachment can of course also be done without screws by clipping, clamps or other known techniques.

As a result, a semiconductor light source 28 of the light module 12 is thereby retained in the base element 10 in its correct position relative to the projection lens 14. FIG. 1 shows such a semiconductor light source 28 in such a position without board and without any existing cooling plate.

On the cooling plate 31 or on the frame 16, a (not shown) can be fixed aperture which projects between the light exit surface of the semiconductor light source 28 and the projection lens 14 in the Lichtabstrahlkegel and limits it so that, if necessary. Only the light entrance surface of the projection lens 28 is illuminated or that is prevented by uncontrolled light propagation outside the actual projection lens 14 lens disturbing light reflections are generated.

Alternatively or additionally, the base element 10, which forms a combination of lens holder and projection lens, may for this purpose be absorptively coated or colored in certain areas. As a result, stylistically seen from the outside, the active, refractive

Lens surface to be highlighted.

The preferably oval inner lens surface can pass directly into a correspondingly oval curved shaped frame 16 of the base member 10, or it is, as in the FIG. 1 is shown, extended to another shape, for example to a rounded rectangular, contoured total area. The then resulting, optically inactive areas 24 in the corners of the surface no longer contribute to the light distribution, but may allow passage of small amounts of light to make the night design of the light module 12. Alternatively, the optically inactive regions 24 are designed to be intransparent. This can be achieved in the manufacture of the base member 10 by a two-component injection molding process. The light entry surface 30 of the projection lens 14 can be sharp-edged into the optically inactive regions 24. However, the light entry surface 30 of the projection lens 14 preferably merges with a continuously curved transition surface into the optically non-effective regions 24 in order to give the exterior design a surface that is continuous without edges.

The projection lens 14 is arranged in a light beam emanating from the semiconductor light source. The projection lens 14 is designed to be smooth both in its light entry surface 30 and in its light exit surface 22 and has no steps in and between their active refractive subregions. The light-emitting surface 30 of the projection lens 14 facing the semiconductor light source 28 is horizontally subdivided into three regions which merge into one another continuously (ie without steps and without appreciable kinking) and which form part of the shaping of the Serve light-dark boundary and serve for another part, an optimization of the light distribution, in particular with respect to a desired color neutrality (if possible, no color fringes). The projection lens has a first subregion 42, a second subregion 44, and a third subregion 46 lying between the first subregion 42 and the second subregion 44. In this case, the first partial area 42 and the second partial area 44 lie on different sides of an optical axis 48 of the projection lens 14. When the light module 12 is used as intended, one of the two partial areas 42, 44 lies above the optical axis 48 and the other of the two partial areas 42 The center of the third portion 46 is preferably located on the optical axis 48. The center is the center of gravity of the projected in the direction of the optical axis 48 in a plane surface of the third portion 46th

The subdivision of the projection lens 14 into these subregions is effected by the above-mentioned subdivision of the semiconductor light source 28 facing light entrance surface 30 of the projection lens 14 in three sub-areas which are arranged successively in the vertical direction and which pass without steps and without appreciable kink into each other, so that Overall, a smooth light entrance surface is maintained.

The FIG. 4 shows a so-called helical image representation of the central third portion 46 of the projection lens 14. In the helical image representation of the light entry region of the third portion 46 is thought, or in a simulation, in a plurality of horizontally adjacent lens segments divided, and the marginal edges of the images are provided, which provides each individual segment of the light-emitting surface of the semiconductor light source 28. FIG. 4 shows an ensemble of such spiral pictures.

How to get in FIG. 4 sees, the upper edges of the spiral images in the vertical direction are very close together, so that overall results in a sharp and straight-running cut-off 50, which results in total by direct imaging of the lower edge 28.3 of the light emitting surface of the double chip of the semiconductor light source 28. Since the helical images of a lens curve more strongly the further one moves away from the center of the lens in the vertical direction, the light-dark boundary in the present invention is generated from the third, mid-lens region 46 of the projection lens 14.

This has the further advantage that the helical images there are the brightest and thus a good contrast of the cut-off 50 can be achieved. Furthermore, due to a comparatively small lens curvature of the projection lens 14 in the middle subregion 46, the light hardly undergoes dispersion in the vertical direction, which leads to a light-dark boundary 50 with minimal color fringing. The light distribution generated solely by the third portion 46 is very narrow in the vertical direction and to the area between the cut-off 50, which is about 0.6 ° below the height of the horizon H, and about 5 ° below the horizon H limited. This is not sufficient for an illumination of the vehicle apron. In order to produce a homogeneous illumination before or in the case of the cornering light next to the vehicle, the apron below V = -5 ° must be illuminated. Will all spiral images directly to the cut-off 50 positioned, the apron is dark. To also illuminate this apron uniformly, it is possible to reduce the focal length of the projection lens and thus to increase the helical images. However, this exceeds the feasibility of manufacturing due to the tolerance requirements.

To be able to illuminate the apron nevertheless, spiral images must be lowered. As a consequence of the necessity for the helical images of the third subregion 46 to generate the light-dark boundary 50 approximately at the height of the horizon H, the curved helical images are separated from the upper (first) subregion 42 and lower (second) subregion 44 by a corresponding shape of the first partial surface 30.42 and the second partial surface 30.44 of the light entry surface 24 of the projection lens 14 is lowered. This happens in this way, that is, the surfaces are designed so that all the spiral images of the first subregion 42 and of the second subregion 44 are below a line 50 'parallel to the light-dark boundary 50 and lowered by at least 0.5 ° to a maximum of 2 °. stay. The first partial light distribution 52 and the second partial light distribution 54 are thus below a line 50 ', which is under normal use of the motor vehicle headlamp light module 12 below the generated by the third portion 46 light-dark boundary 50 and a distance of 0.5 ° to minimum The first subarea 42 and the second subarea 44 of the projection lens 14, or the respectively associated subareas 30.42 and 30.44 of the light entry surface 30 of the projection lens 14 are strongly curved, resulting in a color fringing of the respectively associated Wendelbildes leads.

The upper edge of the spiral images from the upper (first) portion 42 of the projection lens 14 has a reddish color fringe, the lower edge of a spectrally complementary bluish color fringe. For the lower (second) portion 44 of the projection lens 14, it behaves vice versa. In order to correct this color effect, the helical images from the upper (first) subregion 42 of the projection lens 14 are superimposed on the helical images from the lower (second) subregion 44. This is done by the partial modification of the shape of the first partial surface 30.42 and the second partial surface 30.44 of the light entry surface 30 of the projection lens. The color fringes complementary in the sense of a color mixture thus result in color neutrality. The overlapping area of the two partial light distributions 52, 54 of the regions 42 and 44, which is closer to the light-dark boundary 50, also falls into the white region of the partial light distribution 56 produced by the central partial region 46. This additionally outshines an additional color fringe there and thus made less noticeable.

The finished light entrance surface 30 of the projection lens 14 thus consists of three partial surfaces: A middle (third) partial surface 30.46, which serves to generate the light-dark boundary 50 and which is already neutral in color, and an upper (first) partial surface 30.42 and a lower (first second) partial surface 30.44, both of which serve to illuminate the apron by lowering the light rays passing through them slightly in comparison to the light rays passing through the middle (third) partial surface 30.46 (directing downwards) and at the same time overlaying them in such a way that color neutrality is achieved.

The three sub-areas 30.42, 30.44 and 30.46 of Light entrance surface 30 of the projection lens 14 and thus also the associated portions 42, 44, 46 of the projection lens 14 have substantially the same lateral spread of each associated light distribution. Before the detail correction of the light entry surface 30, the convexly curved light exit surface 22 of the projection lens 14 is fixed, which has an essentially aspherical, curved shape.

FIG. 5 shows the different partial light distributions and their superposition to a total light distribution. FIG. 5 a shows the first partial light distribution 52 produced by the first partial area 42, and FIG. 5c shows the second partial light distribution generated by the second partial area 44. 54. Both light distributions have a nearly identical shape and differ in the position of their upper and lower fringes, which are marked with r for reddish and b for bluish.

FIG. 5b shows the third narrow part of the distribution generated by the third portion 46, vertically narrower but a sharp light-dark boundary 50 and already color neutral third partial light distribution 56. The partial light distributions 52, 54, 56 are in the normal use of the light module in the horizontal direction H equal width. The first partial light distribution 52 and the second partial light distribution are wider in the vertical direction 54 than the third partial light distribution 56. These two partial light distributions 52, 54 lie below a line 50 'which, when the motor vehicle headlamp light module 12 is used as intended, below the light generated by the third partial area 46. Dark boundary 50 is located and has a distance of at least 0.5 ° to a maximum of 2 ° from the first cut-off (50). The Angular data refer in each case to angles between light beams which, starting from the motor vehicle headlamp light module according to the invention, impinge on a screen perpendicular to the optical axis and which run in a plane which lies perpendicular to the horizon and in which the optical axis runs. FIG. 5d shows the resulting superposition of the partial light distributions 52, 54 and 56. This result of the overlay has a sharp, light-dark boundary 50, is color-neutral and sufficiently wide in the vertical direction to brightly illuminate the apron. The figures relate to an embodiment with a straight cut-off, as is usual for a cornering light (Cornering light).

Claims (13)

A motor vehicle headlamp light module (12) having a semiconductor light source (28) and a projection lens (14) arranged in a light beam emanating from the semiconductor light source (28) and producing a light distribution from the light beam, in which an edge (28.3) of a light exit surface of the semiconductor light source (28) is depicted as a cut-off line (50), the projection lens (14) having a first partial region (42) which generates a first partial light distribution and has a second partial region (44) which generates a second partial light distribution overlapping overlapping with the first partial light distribution, characterized in that the projection lens (14) has a third partial region (46) lying between the first partial region (42) and the second partial region (44) and configured to generate a third partial light distribution which, when the motor vehicle headlamp light module (12 ) is limited by the light-dark boundary (50) generated as the image of the edge (28.3) of the semiconductor light source (28) overlapping the first partial light distribution and the second partial light distribution, wherein the first partial light distribution and the second partial light distribution lie below a line (50 ') which, when the motor vehicle headlamp light module (12) is used as intended, below that generated by the third partial area (46) Light-dark boundary (50) is located and a distance of at least 0.5 ° to a maximum of 2 ° from the first cut-off (50). Light module (12) according to claim 1, characterized in that the first portion (42) and the second portion (44) lie on different sides of an optical axis (48) of the projection lens (14). Light module (12) according to claim 2, characterized in that the first portion (42) under normal use of the light module (12) above the optical axis (48) and the second portion (44) below the optical axis (48). Light module according to claim 3, characterized in that the center of the third portion lies on the optical axis (48). Light module (12) according to any one of the preceding claims, characterized in that the three partial light distributions in the normal use of the light module (12) in the horizontal direction are the same width. Light module (12) according to one of the preceding claims, characterized in that the first partial light distribution and the second partial light distribution in the intended use of the light module (12) in the vertical direction are wider than the third partial light distribution. Light module (12) according to one of the preceding claims, characterized in that the projection lens (14) is smooth in the region of its optical surfaces and has no steps. Light module (12) according to any one of the preceding claims, characterized in that one of the semiconductor light source (28) facing light entrance surface (30) of the projection lens (14) is divided horizontally into three sub-areas, which merge without steps and without significant kink into each other. Light module (12) according to one of the preceding claims, characterized in that the projection lens (14) is integral with a serving as a lens holder frame (16). Light module (12) according to claim 9, characterized in that the projection lens (14) and the frame (16) consist of the same material. Light module (12) according to claim 9 or 10, characterized in that one of the projection lens (14) in the direction of the optical axis (48) facing away from the end of the frame (16) for fixing a semiconductor light source (28) having board (29) and a cooling plate (31) is arranged. Light module (12) according to claim 9, characterized in that the frame (16) has positive locking structures, which together with complementary positive locking structures of the board (29) and / or the cooling plate (31) the position of the semiconductor light source (28) relative to the projection lens ( 14) in the direction of the optical axis (48) and transverse to the optical axis (48) set. Light module (12) according to any one of the preceding claims, characterized in that the semiconductor light source (28) has at least two juxtaposed light exit surfaces which lie in a direction transverse to the optical axis (48) side by side and along this direction by lying in alignment edges be limited.

Images