DE102020119939A1 - Headlight for a vehicle and vehicle with such a headlamp - Google Patents

Abstract

The present invention relates to a headlight (10) for a vehicle (11), comprising: a lens arrangement (12) with a first lens (13), a second lens (14) and a third lens (15), and a light source (16 ) for emitting light rays (17) through the lens arrangement (12), the first lens (13) having a first light entry surface (18), for introducing the light rays (17) from the light source (16) into the lens arrangement (12), and has a first light exit surface (19), the second lens (14) has a second light entry surface (20) and a second light exit surface (21), and the third lens (15) has a third light entry surface (22) and a third light exit surface (23), for directing the light rays (17) out of the lens arrangement (12) and into the vicinity of the headlight (10), and wherein the first lens (13), the second lens (14) and the third lens (15) each have a positive refractive power to combine the light rays ( 17). The invention also relates to a vehicle (11) with at least one headlight (10) according to the invention.

Description

The present invention relates to a headlight for a vehicle, having a lens arrangement with a first lens, a second lens and a third lens, and a light source for emitting light rays through the lens arrangement, the first lens having a first light entry surface for introducing the light rays from the light source into the lens arrangement, and has a first light exit surface, the second lens has a second light entry surface and a second light exit surface, and the third lens has a third light entry surface and a third light exit surface, for guiding the light beams out of the lens arrangement and into the area surrounding the headlight , having. The invention also relates to a vehicle with such a headlight.

Headlights for vehicles such as cars, trucks or motorcycles have a light source and optics for the targeted guidance of the light beams from the light source onto the road and into the area surrounding the vehicle. Conventional optics in vehicle headlights usually have one or two lenses. When using new types of light sources, however, such optics do not depict sharply enough, pick up too few beam cones and/or have problems with the softest possible display of individual pixels of the light source. Optics with more than two lens elements are also known. So far, however, these have not been configured with sufficient light efficiency for headlamp applications in the vehicle sector, are relatively expensive and/or too large. For example, a conventional headlight for vehicles with multiple lens elements goes out of the WO 2017/143371 A1 out.

The object of the present invention is to at least partially take account of the problems described above. In particular, it is the object of the present invention to provide a compact, inexpensive and flexible headlight with the sharpest possible lens for a vehicle and a vehicle with at least one such headlight.

The above object is solved by the patent claims. In particular, the above object is achieved by the headlight according to claim 1 and the vehicle according to claim 15. Further advantages of the invention result from the dependent claims, the description and the figures. Features that are described in connection with the headlight naturally also apply in connection with the vehicle according to the invention and vice versa, so that the disclosure of the individual aspects of the invention is and/or can always be referred to alternately.

According to a first aspect of the present invention, there is provided a headlight for a vehicle. The headlight has a lens arrangement with a first lens, a second lens and a third lens. The headlight further includes a light source for outputting light rays through the lens assembly. The first lens has a first light entry surface, for introducing the light beams from the light source into the lens arrangement, and a first light exit surface. The second lens has a second light entry surface and a second light exit surface. The third lens has a third light entry surface and a third light exit surface for directing the light beams out of the lens arrangement and into the area surrounding the headlight. The first lens, the second lens and the third lens each have a positive refractive power for combining the light rays or at least a majority of the light rays.

Within the scope of the present invention, a one- or two-lens system conventional for vehicle headlights has been turned away and a lens arrangement with three lenses, in particular with exactly three lenses with up to six optically effective surfaces, has been developed. An optically effective surface is to be understood here as a surface that directs light rays that extend through the optical surface from an entry direction into the optical surface into an exit direction from the optical surface, which differs from the entry direction. By dividing the lenses or by dividing a conventional lens into three lens elements, the refractive power is also divided accordingly. The distribution of the refractive power in turn ensures a relatively low tolerance sensitivity with regard to light refraction. In addition, by dividing the refractive power, a particularly high imaging quality with regard to the light beams on the road and/or in the area surrounding the headlight or the vehicle can be achieved. Due to the high image quality and the resulting light efficiency, both legal requirements and customer requirements can be easily met with regard to the light output that can be achieved. In addition, projections of light-dark boundaries on a surface in front of the vehicle with a sufficient gradient can be made possible, even if cornering light scenarios are implemented by switching any pixels on the light source. With the lens arrangement according to the invention and in particular the configuration of the individual lenses, a high-beam light matrix with channels that can be clearly separated can also extend into an outer area a light distribution of the headlight are provided.

The headlight is made available in particular as a vehicle headlight for a motor vehicle, preferably for a road vehicle such as a passenger car, a truck and/or a motorcycle. Combining the light beams can be understood as reducing the angle between the light beams. In particular, the lens arrangement and/or the first lens, the second lens and the third lens are arranged and designed for iteratively combining the light beams. In other words, the lens arrangement is preferably designed in such a way that the light beams and/or a light cone with the light beams are brought together a little further from lens to lens or through each lens. Merging should in particular not be understood to mean merging to a focal point. The lens arrangement can therefore be configured such that an angle of a first cone of light between the light source and the first lens is greater than an angle of a second cone of light between the first lens and the second lens, and that the angle of the second cone of light between the first lens and of the second lens is greater than an angle of a third cone of light between the second lens and the third lens. The first light cone, the second light cone and the third light cone are each to be understood as part of an overall light beam from the light source through the lens arrangement into the area surrounding the headlight. In addition, at least the second light cone and the third light cone are to be understood as an imaginary light cone in which a respective truncated light cone is lengthened to form an imaginary light cone tip with the stated angle. The positive refractive power of the lenses can also be configured in such a way that the light exit angle of the light rays always remains in the positive range and/or the light rays are not brought together in a focal point before exiting the third light exit surface. That is, the refractive power of the lenses and/or the lens arrangement is designed in such a way that the light rays or at least a majority of the light rays are prevented from merging at a focal point within the lens arrangement and/or between the first light entry surface and the third light exit surface.

The three lenses are preferably arranged one behind the other along an optical axis through at least the first lens and the second lens, with the second lens in particular being arranged after the first lens and the third lens being arranged after the second lens in a light exit direction from the light source. The lenses are also preferably arranged concentrically or at least approximately concentrically to one another and/or one behind the other.

According to a further embodiment of the present invention, it is possible that in a headlight the first light entry surface, the second light entry surface, the second light exit surface and/or the third light entry surface each have an aspherical surface and/or are each configured as an aspherical surface. By means of the aspherization of at least one of the light entry surfaces or the light exit surfaces, a relatively high imaging quality can be achieved with a small overall size in the proposed lens arrangement. The first light entry surface can have a straight and/or flat surface, in particular a straight circular surface. The first light exit surface preferably has a spherical surface or is designed as a spherical surface.

Furthermore, it is possible with a headlight according to the invention that the third light exit surface has a free-form surface and/or is configured as a free-form surface. The free-form surface can be adapted to the respective usage needs of the headlight. For example, a strategy for connection to the apron can be aimed at, which enables a combination with additional systems in the headlight. Within the scope of the present invention, it was found that, in comparison to known systems with a rotationally symmetrical light exit surface, relatively inexpensive, space-saving optics with high quality in terms of light output can be implemented.

It is of particular advantage if the free-form surface in a headlight according to the present invention is the free-form surface in a headlight that is installed in the vehicle for directing the light beams at an angle to an optical axis of the first lens and/or the second lens and to a substrate indicating on which the vehicle is located, configured and designed. Put simply, this is intended to ensure that the light cone from the headlight in the vehicle is directed onto the road, even if the headlight as such is installed in the vehicle in such a way that the optical axis of at least the first lens and/or the second lens extends parallel or substantially parallel to the road or to the ground of the vehicle. The free-form surface is configured and designed to direct at least a portion of the light beams obliquely to the optical axis of the first lens and/or the second lens and to the vehicle's underbody. Accordingly, the free-form surface can partially deviate from an otherwise rotational symmetry of the third lens and/or the third light exit surface. As a result of this deviation, the light image can be changed in such a way that the connection of the headlight to, for example, a headlight element that generates a front field, such as a projection module and/or a reflector system, is improved. In particular, the deviation is designed to direct the light rays towards the ground on which the vehicle with a headlight installed therein is located. The free-form surface can also be designed to cancel out an imaging effect of the headlight. The free-form surface is to be understood in particular as neither a spherical nor an aspherical surface shape.

Furthermore, it is possible that in a headlight according to the present invention, the first light exit surface has a spherical surface and/or is configured as a spherical surface. A spherical surface can be manufactured relatively inexpensively compared to an aspherical surface. Tests within the scope of the present invention have shown that the first lens with the spherical light exit surface can nevertheless adequately meet the desired quality requirements with regard to imaging quality of the lens arrangement.

In a headlight according to the invention, the focal length of the lens arrangement is preferably in a range between 10 mm and 40 mm. When using an SSL illuminant as the light source, the focal length of the lens arrangement is preferably in a range between 25 mm and 30 mm, in particular at a value of approximately 28 mm. With the values mentioned, a particularly good image quality can be achieved when using SSL lamps.

In a headlight according to the present invention, an SSL light source is used in particular as the light source and/or the light source has at least one SSL light source. In combination with the proposed lens arrangement, a high light output can thus be achieved, which can also be brought onto the road in a clearly visible manner. The interaction of the lens arrangement with an SSL illuminant and/or a corresponding SSL pixel light source enables functions and light distributions that correspond to previous premium matrix modules that are significantly more expensive than the proposed system. With the present solution, for example, complicated and correspondingly high-priced silicone primary optics can be dispensed with.

The imaging of SSL lamps that are relatively small in terms of surface area makes it possible to have systems with short focal lengths in the aforementioned ranges of between 25 mm and 30 mm, for example, which can be built relatively compactly, compared to commercially available systems. The use of SSL multipixel lamps also enables premium matrix headlight functions such as a high-resolution matrix high beam to be implemented. However, this also requires new types of optical systems in order to project the light distributions generated on the light source into the street space as desired, taking into account a wide variety of requirements and specifications. This means that SSL lamps cannot be combined with just any optic. However, this is possible with the proposed lens arrangement. Current premium matrix systems, which are based on individual LEDs with silicon primary optics, have a relatively long focal length and require a correspondingly large amount of space. In addition, such systems are comparatively inefficient in terms of the power required and the resulting light output.

According to a further embodiment variant of the present invention, it is possible that in a headlight the first lens has a diameter in a range between 25 mm and 35 mm, the second lens has a diameter in a range between 40 mm and 50 mm and/or the third lens has a diameter in a range between 50 mm and 60 mm. Despite the compact design, relatively large lens diameters can be used in the proposed lens arrangement. These make it possible to record a correspondingly large opening angle of the light cone from the light source, for example 90° to 160°, and thus to keep the distance between the light source and the lens arrangement and/or the first lens small. This results in a high light efficiency of more than 50%, for example, with typical LED emission characteristics or, depending on the light source used, a desired emission characteristic with an additional compact design. Particularly preferably, the first lens has a diameter in a range between 30 mm and 34 mm, the second lens has a diameter in a range between 42 mm and 46 mm and/or the third lens has a diameter in a range between 51 mm and 55 mm . The first lens preferably has the smallest diameter of the three lenses. The third lens can have the largest diameter of the three lenses. With this design, the inventive, iterative combination of the light beams or narrowing of the light cone can be achieved in a compact and material-saving manner.

In addition, with a headlight according to the present invention, it is possible for the first light entry surface to be at a distance of less than 8 mm, in particular less than 5 mm, from the light source. When trying in the frame According to the present invention, it has been found that the desired light output can still be achieved with this configuration and a relatively compact headlight is nevertheless provided.

In a headlight according to the invention, the first lens is preferably made of glass. This prevents or reduces damage and/or wear from the possible increased thermal stress due to the proximity of the first lens to the light source. The second lens and the third lens can also be made of glass or plastic. The first light entry surface and/or the first light exit surface of the first lens can have an anti-reflection coating. An anti-reflection coating and/or a corresponding structuring of the first lens further increases the efficiency and effectiveness of the lens arrangement and also serves to avoid reactivation of any SSL light source for improved function of the headlight.

In addition, in a headlight according to the invention, the first light exit surface can have a smaller radius of curvature than the second light exit surface and/or a smaller radius of curvature than the third light exit surface. In particular, the first lens has the greatest refractive power of the three lenses. The second lens and the third lens can thus be built correspondingly more compactly or with a relatively small diameter. This ultimately leads to an improved overall compactness of the headlight and a resulting weight saving and cost reduction.

In a headlight according to the present invention, the third light exit surface can have a microstructure with a higher roughness than the other light exit surfaces and/or than the light entry surfaces. The microstructure can reduce the visibility of a gap between pixels of the light source in the projected light on the ground in front of the vehicle. In addition, color fringes at edges in the light distribution caused by dispersion can be reduced and, as a result, legal requirements and customer requirements can be better met. The microstructure can be understood in particular as surface structures and/or surface edge changes in the micrometer range.

According to a further aspect of the present invention, a vehicle is provided with at least one headlight as described in detail above. The vehicle according to the invention thus brings with it the same advantages as have been described in detail with reference to the device according to the invention. The vehicle is preferably designed in the form of a road vehicle, in particular in the form of a car, a truck or a motorcycle.

Further measures improving the invention result from the following description of various exemplary embodiments of the invention, which are shown schematically in the figures. All of the features and/or advantages resulting from the claims, the description or the figures, including structural details and spatial arrangements, can be essential to the invention both on their own and in the various combinations.

• 1 eine Lichtquelle mit einer Linsenanordnung für einen Scheinwerfer gemäß einer bevorzugten Ausführungsform der vorliegenden Erfindung, und
• 2 ein Fahrzeug mit erfindungsgemäßen Scheinwerfern.

The invention is explained in more detail below with reference to the attached drawings. show:

• 1 a light source with a lens assembly for a headlight according to a preferred embodiment of the present invention, and
• 2 a vehicle with headlights according to the invention.

Elements with the same function and mode of operation are each provided with the same reference symbols in the figures.

1 FIG. 1 shows a headlight 10 for a vehicle 11 according to a preferred embodiment. The headlight 10 has a lens arrangement 12 with a first lens 13 , a second lens 14 and a third lens 15 . In addition, the headlight 10 has a light source 16 for outputting light rays 17 through the lens arrangement 12 . The first lens 13 has a first light entry surface 18, for introducing the light rays 17 from the light source 16 into the lens arrangement 12 or through which the light rays 17 from the light source 16 enter the first lens 13, and a first light exit surface 19, for forwarding the Light beams 17 exit from the first lens 13 to the second lens 14 or through which the light beams 17 exit from the first lens 13 in the direction of the second lens 14 . The second lens 14 has a second light entry surface 20 for introducing the light rays 17 from the first lens 13 or through which the light rays 17 enter the second lens 14 from the first lens 13, and a second light exit surface 21 for forwarding the light rays 17 from the second lens 14 to the third lens 15 or through which the light beams 17 exit from the second lens 14 in the direction of the third lens 15. The third lens 15 has a third light entry surface 22 for introducing the light rays 17 from the second lens 14 or through which the light rays 17 enter the third lens 15 from the second lens 14, and a third light outlet Ride surface 23, for directing the light beams 17 out of the lens arrangement 12 and into the area surrounding the headlight 10 or through which the light beams 17 are guided out of the third lens 15, on.

The first lens 13, the second lens 14 and the third lens 15 each have a positive refractive power for combining the light beams 17. That is, the light beams 17 are bundled a little more strongly from the light source 16 through each lens 13, 14, 15, but without converging at a focal point within the lens array 12 or after leaving the lens array 12. As in 1 As can be seen, the three lenses 13, 14, 15 are arranged one behind the other along the optical axis 24 and essentially concentrically with one another.

The first light entry surface 18 is designed as a straight or flat surface. The second light entry surface 20, the second light exit surface 21 and the third light entry surface 22 are each designed in the form of an aspherical surface. The third light exit surface 23 is designed as a free-form surface. This is indicated by the partial deviation of the third light exit surface 23 shown in bold from an otherwise spherical third light exit surface 23 . The free-form surface is thus configured in a headlight 10 installed in the vehicle 11 for directing the light beams obliquely to the optical axis 24 of the first lens 13 and the second lens 14 and to a substrate 25 on which the vehicle 11 is located and designed. This can be particular with regard to 2 be recognized, in which a vehicle 11 is shown with the headlight 10. The first light exit surface 19 is configured as a spherical surface.

The lens arrangement 12 shown has a focal length of approximately 28 mm. For this purpose, the light source 16 has an SSL light source. The first lens 13 has a diameter of 31 mm, the second lens 14 has a diameter of 44 mm and the third lens 15 has a diameter of 53 mm. Thus, the first lens 13 has the smallest diameter of the three lenses 13, 14, 15 and the third lens 15 has the largest diameter of the three lenses 13, 14, 15. The first light entry surface 18 is at a distance of approximately 4 mm from the light source 16 . The first lens 13 is made of glass, while the second lens 14 and the third lens 15 are made of plastic. Furthermore, the first light entry surface 18 and the first light exit surface 19 each have an anti-reflection coating. In addition, the third light exit surface 23 has a microstructure with a higher roughness than the other light exit surfaces 19, 21 and than the light entry surfaces 18, 20, 22.

In addition to the illustrated embodiments, the invention permits further design principles. That is, the invention should not be considered limited to the exemplary embodiments explained with reference to the figures. In particular, the type of lens shapes or the type of light entry surfaces 18, 20, 22 and light exit surfaces 19, 21, 23 can deviate from the variants shown.

Reference List

10

headlight

11

vehicle

12

lens arrangement

13

first lens

14

second lens

15

third lens

16

light source

17

beam of light

18

first light entry surface

19

first light exit surface

20

second light entry surface

21

second light exit surface

22

third light entry surface

23

third light exit surface

24

optical axis

25

underground

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• WO 2017/143371 A1 [0002]

Claims (15)

Headlamp (10) for a vehicle (11), comprising: - a lens arrangement (12) with a first lens (13), a second lens (14) and a third lens (15), and - a light source (16) for outputting of light rays (17) through the lens arrangement (12), wherein - the first lens (13) has a first light entry surface (18) for introducing the light rays (17) from the light source (16) into the lens arrangement (12), and a first light exit surface (19), the second lens (14) has a second light entry surface (20) and a second light exit surface (21), and the third lens (15) has a third light entry surface (22) and a third light exit surface (23), for guiding the light beams (17) out of the lens arrangement (12) and into the area surrounding the headlight (10), characterized in that the first lens (13), the second lens (14) and the third lens (15) each have a have positive refractive power for merging the light beams (17). headlight (10) after claim 1 , characterized in that the first light entry surface (18), the second light entry surface (20), the second light exit surface (21) and/or the third light entry surface (22) each have an aspherical surface and/or are each configured as an aspherical surface. Headlight (10) according to one of the preceding claims, characterized in that the third light exit surface (23) has a free-form surface and/or is designed as a free-form surface. headlight (10) after claim 3 , characterized in that the free-form surface in a headlight (10), which is installed in the vehicle (11), for directing the light beams obliquely to an optical axis (24) of the first lens (13) and / or the second lens (14) and is configured and designed towards a ground (25) on which the vehicle (11) is located. Headlight (10) according to one of the preceding claims, characterized in that the first light exit surface (19) has a spherical surface and/or is designed as a spherical surface. Headlight (10) according to one of the preceding claims, characterized in that the focal length of the lens arrangement is in a range between 10 mm and 40 mm. Headlight (10) according to one of the preceding claims, characterized in that the light source (16) has an SSL light source. Headlight (10) according to one of the preceding claims, characterized in that the first lens (13) has a diameter in a range between 25 mm and 35 mm, the second lens (14) has a diameter in a range between 40 mm and 50 mm and/or the third lens (15) has a diameter in a range between 50 mm and 60 mm. Headlight (10) according to one of the preceding claims, characterized in that the first lens (13) has the smallest diameter of the three lenses (13, 14, 15) and the third lens (15) has the largest diameter of the three lenses (13, 14, 15). Headlight (10) according to one of the preceding claims, characterized in that the first light entry surface (18) is at a distance of less than 8 mm from the light source (16). Headlight (10) according to one of the preceding claims, characterized in that the first lens (13) consists of glass. Headlight (10) according to one of the preceding claims, characterized in that the first light entry surface (18) and/or the first light exit surface (19) have an anti-reflection coating. Headlight (10) according to one of the preceding claims, characterized in that the first light exit surface (19) has a smaller radius of curvature than the second light exit surface (21) and/or a smaller radius of curvature than the third light exit surface (23). Headlight (10) according to one of the preceding claims, characterized in that the third light exit surface (23) has a microstructure with a higher roughness than the other light exit surfaces (19, 21) and/or than the light entry surfaces (18, 20, 22). Vehicle (11) with at least one headlight (10) according to one of the preceding claims.

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