HEADLIGHT FOR A MOTOR VEHICLE

Description

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

[0002] Such a headlight must, among other things, meet the lighting requirements of the respective approval area, such as ECE, CCC, or SAE. The photometry required also includes so-called OS values ​​(overhead sign values). These are measurement points that lie above the cut-off line of the light distribution.

[0003] A headlight of the type described above is known from DE 10 2016 109 132 A1. The headlight described therein comprises a plurality of first light sources designed as light-emitting diodes for a high beam and a low beam. The headlight further comprises a primary optics system consisting of two light guides, into which the light emitted by the light-emitting diodes is coupled. The headlight further comprises a secondary optics system designed as a projection lens, which can project the light emitted by the primary optics into the exterior of the motor vehicle. The light distribution generated by the headlight has a horizontal cut-off line and light components arranged above this cut-off line to implement an OS function (overhead sign function).To create this OS function, a prismatic step is formed on a first of the primary optics' light guides, through which light emerging from the second of the light guides can enter the first light guide. This portion of the light entering the first light guide from the second light guide is deflected upward by the secondary optics, so that it reaches a region above the cut-off line of the low beam.

[0004] A disadvantage is that additional geometries on the primary optics or projection lens result in increased manufacturing effort and can lead to an increased susceptibility to defects. This increased susceptibility to defects can be caused, for example, by shape deviations in terms of functionality or by air inclusions, streaks, flow lines, or the like in terms of optical quality.

[0005] Another headlight is known from DE 10 2009 020 593 A1. The headlight described therein features a secondary optics system designed as a plano-convex projection lens, which has more than 100 discretely distributed projections on its convex surface, which serve to implement an OS function. In addition to increased manufacturing effort and potentially increased susceptibility to errors, geometries added to the projection lens usually have the major disadvantage of being visible when viewing the headlight and thus negatively affecting its external appearance.

[0006] Another headlight is known from EP 2 730 836 A1. In the headlight described therein, a metallic aperture is provided between a primary lens and a secondary lens. The aperture has reflective surfaces that serve to implement an OS function. The aperture is an additional component, resulting in increased manufacturing, assembly, and adjustment effort.

[0007] The problem underlying the present invention is to create a headlight of the type mentioned at the outset which can be produced more cost-effectively and / or which enables the generation of OS values ​​using simple means.

[0008] This is achieved by a headlight of the type mentioned above with the characterizing features of claim 1. The subclaims relate to preferred embodiments of the invention.

[0009] According to claim 1, the headlight is designed so that a portion of the light emanating from the primary optics is reflected back to the primary optics by the secondary optics, this reflected portion of the light is reflected by the primary optics in the direction of the secondary optics and, after passing through the secondary optics, is deflected into a region above the cut-off line to implement the OS function. With such a design, additional geometries on both the primary optics and the secondary optics can be dispensed with to implement the OS function. Furthermore, this results in simplified manufacturability of the primary optics and the secondary optics. The manufacturing effort can be reduced, for example, by dispensing with additional mold inserts for introducing the additional geometries into the primary optics or the secondary optics.Furthermore, the additional geometries prevent defects such as air pockets or streaks. An additional component such as a reflective baffle or the like is also eliminated. This allows the OS values ​​to be generated without altering a predefined headlight design.

[0010] A further advantage lies in the use of the light reflected back from the secondary optics to generate the OS values. Without deliberate use, this reflected light would spread as disruptive scattered light in the headlight and potentially lead to undesirable effects, such as bright spots in the light distribution or glare.

[0011] It can be provided that the primary optics has a surface facing the secondary optics, which is designed to reflect the portion of the light reflected back by the secondary optics in the direction of the secondary optics. In particular, the surface of the primary optics facing the secondary optics can be oriented such that the normal to the surface encloses an angle equal to or not equal to 0° with the horizontal when the headlight is installed in the motor vehicle. For example, the surface of the primary optics facing the secondary optics can be oriented such that the propagation direction of the portion of the light reflected by the surface in the direction of the secondary optics is inclined upwards and / or downwards relative to the horizontal when the headlight is installed in the motor vehicle.For example, by tilting downwards, this portion of the light can be deflected upwards during projection by the secondary optics, so that it reaches an area above the cut-off line.

[0012] It is possible to provide the surface of the primary optics facing the secondary optics with a reflective coating. This can increase the reflectance of the surface of the primary optics facing the secondary optics, allowing a larger portion of the reflected light to be used to generate the OS values.

[0013] It can be provided that the surface of the primary optics facing the secondary optics is flat or curved and / or that the surface of the primary optics facing the secondary optics is provided with a structure, such as graining. In particular, in the curved design, the surface of the primary optics facing the secondary optics can be concavely or convexly curved. By appropriately inclining and shaping the surface of the primary optics facing the secondary optics, the reflected light can be shaped and reflected again towards the secondary optics such that the shaped and reflected light can be used to generate the desired OS values.

[0014] It is possible for the surface of the primary optics facing the secondary optics to be part of the at least one light exit surface of the primary optics or to correspond to the at least one light exit surface. Alternatively, it can be provided that the surface of the primary optics facing the secondary optics is not part of the at least one light exit surface of the primary optics and / or does not correspond to the at least one light exit surface. In this case, the surface of the primary optics facing the secondary optics can be formed, for example, on a base, in particular a base plate of the primary optics.

[0015] It is possible for the secondary optics to have a light entry surface for the light emanating from the at least one light exit surface of the primary optics, as well as a light exit surface for the light entering through the light entry surface. The light entry surface of the secondary optics can be configured to reflect the portion of the light emanating from the primary optics back to the primary optics.

[0016] It can further be provided that the secondary optics are configured so that the portion of the light reflected from the surface of the primary optics facing the secondary optics in the direction of the secondary optics enters the secondary optics through the light entry surface and subsequently exits the secondary optics through the light exit surface. Thus, the secondary optics can contribute to the realization of the OS function without geometric modification.

[0017] It is possible for the at least one light source to be designed as a light-emitting diode or laser diode, in particular wherein a plurality of light-emitting diodes and / or laser diodes serving as light sources are provided. In particular, the primary optics can have a plurality of light entry surfaces, wherein at least one of the light sources is assigned to each of the light entry surfaces such that the light emanating from the light source enters the assigned light entry surface.

[0018] The invention is explained in more detail below with reference to the accompanying drawings. In the drawings: Fig. 1 a schematic side view of a headlight according to the invention with exemplary light rays drawn in.

[0019] In the figure, identical and functionally identical parts are provided with the same reference numerals.

[0020] The headlight shown comprises a plurality of light sources 1 that emit light 2 during operation of the headlight. The light sources 1 are designed as light-emitting diodes (LEDs). Alternatively, laser diodes can be provided instead of the light-emitting diodes.

[0021] The headlight further comprises a primary optics unit 3 having a plurality of collimation optics units 4, each of which is assigned to one of the light sources 1. For the light 2 of one of the light sources 1, each of the collimation optics units 4 has a light entry surface 5 and a light exit surface 6. It is also possible, for example, for only one common light exit surface to be provided for all collimation optics units 4. The primary optics unit 3 further comprises a base plate 7 on which the collimation optics units 4 are arranged.

[0022] The headlight further comprises a secondary optic 8, which in the illustrated embodiment is designed as a single lens. The lens can be designed, for example, as a plano-convex lens. It is certainly possible to provide a more complex secondary optic, for example, one consisting of multiple components.

[0023] The secondary optics 8, which in the illustrated embodiment is designed as a lens, has a light entry surface 9 for the light 2 emanating from the at least one light exit surface 6 of the primary optics 3 and a light exit surface 10 for the light entering through the light entry surface 9.

[0024] During operation of the headlight, the light 2 emanating from the at least one light exit surface 6 of the primary optics 3 is projected by the secondary optics 8 into the exterior of the motor vehicle, so that a light distribution is generated there which has a horizontal light-dark boundary and light components arranged above this light-dark boundary to implement an OS function.

[0025] To implement this OS function, a portion 11 of the light 2 is used, which is reflected back by the light entry surface 9 of the secondary optics 8. This portion 11 of the light 2 strikes a surface 12 of the primary optics 3 facing the secondary optics 8. This surface 12 is the end face of the base plate 7 of the primary optics 3 facing the secondary optics 8. A portion 13 of the reflected portion 11 is reflected back by the surface 12 toward the secondary optics 8. This portion 13 enters the secondary optics 8 through the light entry surface 9 and exits slightly upwards through the light exit surface 10.

[0026] It is entirely possible to use a different surface of the primary optics 3 for reflecting the portion 11 reflected back by the secondary optics 8 instead of the front side of the base plate 7. For example, at least one surface on one or more of the collimation optics 4 can be used. In particular, one or more of the light exit surfaces 6 of the collimation optics 4 can also be used for reflecting the portion 11 of the light 2 reflected back by the secondary optics 8.

[0027] The surface 12 of the primary optics 3 intended for reflecting the portion 11 of the light 2 reflected back by the secondary optics 8 can be oriented such that the normal to the surface 12, when the headlight is installed in the motor vehicle, encloses an angle equal to or different from 0° with the horizontal. For example, the surface 12 of the primary optics 3 facing the secondary optics 8 can be oriented such that the propagation direction of the portion 13 of the light 2 reflected by the surface 12 toward the secondary optics 8 is inclined downward relative to the horizontal when the headlight is installed in the motor vehicle. As a result, this portion 13 of the light is deflected upward upon passing through the secondary optics 8, so that it reaches a region above the cut-off line.Alternatively, the surface 12 of the primary optics 3 facing the secondary optics 8 can also be aligned such that the propagation direction of the portion 13 of the light 2 reflected by the surface 12 in the direction of the secondary optics 8 is inclined upwards relative to the horizontal when the headlight is installed in the motor vehicle.

[0028] It is possible for the surface 12 of the primary optics 3 intended for reflecting the portion 11 of the light 2 reflected back by the secondary optics 8 to be provided with a reflective coating. This allows the reflectance of the surface of the primary optics facing the secondary optics to be increased, so that a larger portion 13 of the reflected light 2 can be used to generate the OS values.

[0029] In the illustrated embodiment, the surface 12 of the primary optics intended for reflecting the portion 11 of light 2 reflected back by the secondary optics 8 is concavely curved. Alternatively, the surface 12 can also be flat or convexly curved. By appropriately designing the surface 12 intended for reflecting the portion 11 of light 2 reflected back by the secondary optics 8, the portion 13 of light 2 can be suitably shaped so that the shaped and reflected portion 13 of light 2 can be used to generate the desired OS values. List of reference symbols

[0030] 1Light source 2Light emanating from the light source 3Primary optics 4Collimation optics 5Light entry surface of the collimation optics 6Light exit surface of the collimation optics 7Base plate of the primary optics 8Secondary optics 9Light entry surface of the secondary optics 10Light exit surface of the secondary optics 11Portion of the light reflected back from the secondary optics 12Surface of the primary optics facing the secondary optics 13Portion of the light reflected towards the secondary optics

Claims

1. Headlamp for a motor vehicle, comprising - at least one light source (1) that emits light (2) when the headlamp is in operation, - a primary lens (3) with at least one light receiving surface (5) which receives the light (2) originating from the at least one light source (1) and at least one light emitting surface (6), - a secondary lens (8) that, when the headlamp is in operation, projects the light (2) originating from the at least one light emitting surface (6) of the primary lens (3) to the exterior of the motor vehicle where it generates a light distribution with a horizontal light-dark cut-off line and light components arranged above this light-dark cut-off line in order to create an overhead sign (OS) function, characterized in that the headlamp is designed such that a portion (11) of the light (2) emitted by the primary lens (3) is reflected back to the primary lens (3) by the secondary lens (8) and that this reflected portion (11) of the light (2) is reflected by the primary lens (3) towards the secondary lens (8), and after passing through the secondary lens (8) is deflected into a region above the light-dark cut-off line to create the overhead sign (OS) function.

2. A headlamp in accordance with Claim 1, characterized in that the primary lens (3) has a surface (12) facing towards the secondary lens (8) that is designed to reflect the portion (11) of the light (2) reflected back by the secondary lens (8) in the direction of the secondary lens (8).

3. A headlamp in accordance with Claim 2, characterized in that the surface (12) of the primary lens (3) facing towards the secondary lens (8) is designed such that the normal on the surface of the headlamp when the headlamp is installed in the motor vehicle forms an angle equal to 0º or not equal to 0º relative to the horizontal.

4. A headlamp in accordance with one of Claims 2 or 3, characterized in that the surface (12) of the primary lens (3) facing towards the secondary lens (8) is designed such that the direction of propagation of the portion (13) of the light (2) reflected by the surface (12) in the direction of the secondary lens (8) is inclined upwards and / or downwards relative to the horizontal when the headlamp is installed in the motor vehicle.

5. A headlamp in accordance with one of Claims 2 through 4, characterized in that the surface (12) of the primary lens (3) facing towards the secondary lens (8) has a reflective coating.

6. A headlamp in accordance with one of Claims 2 through 5, characterized in that the surface (12) of the primary lens (3) facing towards the secondary lens (8) is designed to be flat or curved and / or that the surface (12) of the primary lens (3) facing towards the secondary lens (8) has a structure, such as a graining.

7. A headlamp in accordance with Claim 6, characterized in that the surface (12) of the primary lens (3) facing towards the secondary lens (8) has a concave or convex curvature.

8. A headlamp in accordance with one of Claims 2 through 7, characterized in that the surface (12) of the primary lens (3) facing towards the secondary lens (8) forms part of the at least one light emitting surface (6) of the primary lens (3) or corresponds to the at least one light emitting surface (6).

9. A headlamp in accordance with one of Claims 2 through 7, characterized in that the surface (12) of the primary lens (3) facing towards the secondary lens (8) does not form part of the at least one light emitting surface (6) of the primary lens (3) and / or does not correspond to the at least one light emitting surface (6).

10. A headlamp in accordance with Claim 9, characterized in that the surface (12) of the primary lens (3) facing towards the secondary lens(8) is formed on a base, in particular on a base plate (7) of the primary lens (3).

11. A headlamp in accordance with one of Claims 1 through 10, characterized in that the secondary lens (8) has a light receiving surface (9) for the light (2) emitted via the at least one light emitting surface (6) of the primary lens (3) and a light emitting surface (10) for the light (2) entering via the light receiving surface (9).

12. A headlamp in accordance with Claim 11, characterized in that the light receiving surface (9) of the secondary lens (8) is designed to reflect the portion (11) of the light (2) emitted by the primary lens (3) back to the primary lens (3).

13. A headlamp in accordance with Claim 11 in its reference back to one of Claims 2 through 10, characterized in that the secondary lens (8) is designed such that the portion (13) of the light (2) reflected by the surface (12) of the primary lens (3) facing towards the secondary lens (8) in the direction of the secondary lens (8) enters the secondary lens (8) via the light receiving surface (9) and is then emitted from the secondary lens (8) via the light emitting surface (10).

14. A headlamp in accordance with one of Claims 1 through 13, characterized in that the at least one light source (1) is designed as an LED or laser diode with, in particular, a plurality of light-emitting diodes or laser diodes being used as light sources (1).

15. A headlamp in accordance with one of Claims 1 through 14, characterized in that the primary lens (3) has a plurality of light receiving surfaces (5) with at least one of the light sources (1) being assigned to each of the light receiving surfaces (5) in such a way that the light (2) emitted by the light source (1) enters the assigned light receiving surface (5).