Headlamp for motor vehicle

Abstract

The invention relates to a headlamp for a motor vehicle, comprising: at least one light source (1); an optical device having a plurality of optical components, which is designed to shape and project the light emitted from the at least one light source into the exterior of the motor vehicle in such a way that a low beam distribution (23) of the headlight is generated, the low beam distribution has a light-dark boundary (21) and a light portion arranged above the light-dark boundary (21) for implementing an OS function; at least one refractive structure (14), which is arranged on at least one of the optical components and has a plurality of structural elements (16), the structure (14) being provided for deflecting light passing through the optical components into a region above a light-dark boundary (21) in order to achieve an OS function; wherein at least one of the structural elements (16) is ring-shaped or partially ring-shaped.

Description

Technical Field

[0001] The invention relates to a headlamp for a motor vehicle according to the preamble of claim 1. The invention also relates to a method for producing an optical component of a headlamp according to the preamble of claim 15. Background Art

[0002] Among other things, such headlamps must meet the optical requirements of the corresponding certification area, such as ECE, CCC or SAE. The photometric measurements to be met also include so-called OS values ​​(Overhead Sign Value). These are measuring points located above the light-dark boundary of the light distribution. Such regulations are used to ensure that, for example, highway signs, which are located above the roadway, can be reliably recognized and read by the driver.

[0003] The light intensity that must be achieved at the corresponding measuring points is relatively low. These measuring points are located at relatively large positive vertical angles. The requirement to operate these measuring points is in a certain contradiction with the main requirement for the low beam, namely that no or almost no light should be emitted into the traffic space above the light-dark boundary. The entire headlamp is basically designed for this.

[0004] A headlamp of the above-mentioned type is known from DE 10 2009 020 593 A1. In the headlamp described therein, a secondary optical system is provided which is designed as a plano-convex projection lens and has more than one hundred discretely distributed protrusions on its convex surface, which serve to realize the OS function. In addition to the increased manufacturing costs and the possible increased probability of errors, the geometric structures added to the projection lens usually have the great disadvantage that they are visible when viewing the headlamp and thus negatively affect the external appearance of the headlamp.

[0005] Another headlamp is known from DE102016109132A1. The headlamp described therein comprises a plurality of first light sources configured as light emitting diodes for high beam and low beam. The headlamp also comprises a primary optical device, which is composed of two optical waveguides, into which the light from the light emitting diodes is coupled. The headlamp also comprises a secondary optical device configured as a projection lens, which can project the light from the primary optical device into the external space of the motor vehicle. Here, the light distribution generated by the headlamp has a horizontal light-dark boundary and a light portion arranged above the light-dark boundary for realizing an OS function (overhead sign function). In order to produce this OS function, a prismatic step is configured on the first light conductor in the light conductor of the primary optical device, through which the light leaving the second light conductor in the light conductor can enter the first light conductor. This portion of light entering the first light conductor from the second light conductor is deflected upward by the secondary optical device, so that it reaches the area above the light-dark boundary of the low beam.

[0006] A disadvantage here is that the additional geometric structures on the primary optics or on the projection lens mean increased manufacturing costs and can lead to an increased probability of error. The increased probability of error can be caused by shape deviations in terms of functionality or by air inclusions, schlieren, flow lines, etc. in terms of optical quality. Summary of the invention

[0007] The problem underlying the invention is to create a headlamp of the type mentioned at the outset which can be produced more simply and more cost-effectively. Furthermore, a method for producing an optical component of a headlamp is to be specified.

[0008] This is achieved according to the invention by a headlamp of the type mentioned in the introduction having the characterizing features of claim 1 and by a method of the type mentioned in the introduction having the characterizing features of claim 15. The dependent claims relate to preferred embodiments of the invention.

[0009] According to claim 1, at least one of the structural elements is configured as an annular or partially annular. Here, a plurality of structural elements, preferably all structural elements, in the structural elements of the refractive structure can be configured as annular or partially annular. Thus, the structural element can deflect part of the light passing through the structural element in a desired direction, just like a Fresnel lens.

[0010] There is the following feasible scheme: the structural elements configured as annular or partially annular are arranged coaxially or concentrically with each other. Here, the diameter of the first structural element in the structural element configured as annular or partially annular can be smaller than the diameter of the second structural element in the structural element configured as annular or partially annular.

[0011] It can be provided that at least one of the structural elements is designed as a partially annular structure, so that the structural element extends in the circumferential direction over less than 360°, in particular only over a sector of a circle. As a result, only a smaller part of the optical component on which the refractive structure is arranged is modified, so that the optical component can more effectively realize its original function.

[0012] It is possible that the structural elements of the at least one structure have a width of between 0.5 mm and 1.0 mm. Such dimensions make the refractive structures easier to produce than, for example, microscopic structures.

[0013] It may be provided that at least one of the optical components is designed as a lens, in particular as an aspherical lens, into which the refractive structure is integrated.

[0014] Alternatively, it can be provided that at least one of the optical components is designed as a lens with a Fresnel structure, the refractive structure being integrated into the Fresnel structure. In this case, the Fresnel structure can include an annular step, each of which has a useful side and an interfering side, the useful side being a region of the step that is provided for light to pass through it, and the interfering side being a region of the step that is not provided for light to pass through it, both the useful side and the interfering side of the Fresnel structure enclosing an angle of attack with the optical axis of the lens. The geometric structure of the refractive structure integrated into the Fresnel structure can be given by a deterministic method with a suitable algorithm. As a result, no optimization loop is required and iterations are omitted.

[0015] There is a feasible solution as follows: the integration of the refractive structure into the Fresnel structure causes a partial change in the angle of attack of the interfering side of the Fresnel structure, in particular, the useful side of the Fresnel structure is not changed by the integration of the refractive structure into the Fresnel structure. By maintaining the geometry of the useful side, the original function of the Fresnel structure is not impaired. Light scattered on the interfering side of the Fresnel structure generally produces scattered light, which is deflected into a spatial angle range above the light-dark boundary. This scattered light may lead to an increase in glare, especially in the forward direction or in the so-called HV value area. By changing the angle of attack of the interfering side of the Fresnel structure, the spatial angle range into which the scattered light is deflected is moved upward. This makes it possible to: on the one hand reduce the undesired glare in the forward direction, and on the other hand increase the overhead sign value.

[0016] It can be provided that the headlight comprises a primary optics and a secondary optics, in particular the primary optics is provided for shaping the light originating from the at least one light source so as to produce an extended light distribution, and the secondary optics is provided for converting the extended light distribution produced by the primary optics into a light distribution corresponding to the low beam distribution of the headlight. In this case, the secondary optics can have a projection lens.

[0017] There is the possibility that the refractive structure is arranged on the projection lens of the secondary optics. In this case, the refractive structure can be integrated into the coupling-in side or coupling-out side of the projection lens of the secondary optics.

[0018] According to claim 15, the optical component is produced from plastic by injection molding, the refractive structure being produced during the injection molding. In this way, an additional work step for introducing the refractive structure into the optical component is omitted. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be described in more detail below with the aid of the accompanying drawings.

[0020] Figure 1 shows a schematic side view of a headlamp according to the invention with exemplary depicted light rays;

[0021] Figure 2 Show according to Figure 1 A perspective view of a first embodiment of a projection lens for a headlight, wherein the projection lens is provided with a Fresnel structure;

[0022] Figure 3a A portion of a Fresnel structure in which a refractive structure for realizing an OS function is not integrated is shown;

[0023] Figure 3b A partial view of a Fresnel structure in which a refractive structure for realizing an OS function is integrated is shown;

[0024] Figure 4a Show according to Figure 3a A schematic cross-sectional view of a portion of a Fresnel structure;

[0025] Figure 4b Show according to Figure 3b A schematic cross-sectional view of a portion of a Fresnel structure;

[0026] Figure 5a Show according to Figure 4a The cross-sectional views are exaggerated to show schematic details;

[0027] Figure 5b Show according to Figure 4b The cross-sectional views are exaggerated to show schematic details;

[0028] Figure 6 A perspective view showing a second embodiment of a projection lens of a headlamp according to the invention, wherein the projection lens is provided with a Fresnel structure in which refractive structures for realizing an OS function are integrated in sections;

[0029] Figure 7 A perspective view showing a projection lens of a headlamp according to the prior art;

[0030] Figure 8 A perspective view showing a third embodiment of a projection lens for a headlamp according to the present invention;

[0031] Fig. 9 shows the light distribution generated by a headlamp without a refractive structure for implementing an OS function;

[0032] Fig.10 Shown by Figure 1 The light distribution produced by the headlights. DETAILED DESCRIPTION

[0033] In the figures, identical components and components having the same function are provided with the same reference symbols.

[0034] Figure 1 The illustrated embodiment of the headlight according to the invention comprises two light sources 1, which are only schematically illustrated, a primary lens system 2 having two optical components 3 connected to one another, and a secondary lens system 4, which in particular has only one optical component designed as a projection lens 5. It is entirely possible for the primary lens system 2 to consist of only one component 3 or of more than two components 3. It is also possible for the secondary lens system 4 to consist of more than one component.

[0035] In this case, the primary optics 2 is provided for shaping the light 6 originating from the light source 1 so that an extended light distribution is generated. Furthermore, the secondary optics 4 is provided for converting the extended light distribution generated by the primary optics 2 into a light distribution corresponding to a low-beam light distribution of a headlight, which has a light-dark boundary and a light component arranged above the light-dark boundary for realizing an OS function.

[0036] The projection lens 5 has an incoupling side 7 for the light 6 originating from the primary optical system 2 and an outcoupling side 8, from which the light 6 can exit. The projection lens 5 is designed as a lens with a Fresnel structure 9, wherein the Fresnel structure 9 is arranged on the outcoupling side 8 of the projection lens 5 (see Figure 1 and Figure 2 ). In the exemplary embodiment shown, the coupling-in side 7 is designed to be flat.

[0037] The Fresnel structure 9 comprises an annular step 10, each of which has a useful side surface 11 and an interfering side surface 12 (see FIG. 3 , Figure 4a and Figure 5a ). Here, the useful side 11 is the area of ​​the step 10 that is provided for light to pass through, while the interfering side 12 is the area of ​​the step 10 that is not provided for light to pass through. Here, both the useful side 11 and the interfering side 12 of the Fresnel structure 9 form an angle of attack α, β with the optical axis 13 of the lens (see Figure 5a ).

[0038] In the embodiment shown, the height of the annular step 10 increases radially outward from the center of the projection lens 5. Figure 4a It can be seen that it shows a radial cross-sectional view of the Fresnel structure 9, wherein Figure 4a The left end of corresponds to the center of the projection lens 5, and Figure 4a The right end of corresponds to the edge of the projection lens 5. It is entirely possible that the height of the step 10 does not change in the radial direction or changes in another way.

[0039] Furthermore, a refractive structure 14 is provided for realizing the OS function, which is integrated at least in sections into the Fresnel structure 9. Figure 3b In the embodiment of the invention, the refractive structure 14 is integrated into the Fresnel structure 9 over the entire outcoupling side 8 of the projection lens 5. Figure 6 In the exemplary embodiment of FIG. 8 , the refractive structure 14 is integrated into the Fresnel structure 9 only in a section 15 on the outcoupling side 8 .

[0040] Corresponding to the step 10 of the Fresnel structure 9, the refractive structure 14 is configured as an annular or partially annular structural element 16 (see Figure 3b In this case, the structural elements 16 of the refractive structure 14 can have a width b in the radial direction of between 0.5 mm and 1.0 mm (see Figure 4b ).

[0041] In the embodiment shown, the height of the structural elements 16 also increases from the center of the projection lens 5 in the radial direction outwards. Figure 4b It can be seen that it shows a radial cross-sectional view of the refractive structure 14, wherein Figure 4b The left end of corresponds to the center of the projection lens 5, and Figure 4b The right end of corresponds to the edge of the projection lens 5. It is entirely possible that the height of the structural element 16 does not change in the radial direction or changes in another way.

[0042] Like the Fresnel structure 9, the structural elements 16 of the refractive structure 14 each have a useful side surface 17 and a disturbing side surface 18 (see Figure 4b and Figure 5b ). In the embodiment shown, the useful side 17 of the refractive structure 14 corresponds to the useful side 11 of the Fresnel structure 9. In particular, the angle of attack α′ of the useful side 17 of the refractive structure 14 is equal to the angle of attack α of the useful side 11 of the Fresnel structure 9. By maintaining the geometry of the useful side 17, the actual function of the Fresnel structure 9, in particular as a projection lens, is not impaired.

[0043] However, the angle of attack β' of the interfering side 18 of the refractive structure 14 is not equal to the angle of attack β of the interfering side 12 of the Fresnel structure 9. For example, the angle of attack β of the interfering side 12 of the Fresnel structure 9 is approximately equal to 2°, while the angle of attack β' of the interfering side 18 of the refractive structure 14 is approximately equal to 0°. By changing the angle of attack β' of the interfering side 18 of the refractive structure 14, the spatial angle range in which the scattered light is deflected is shifted upward. Thus, the refractive structure 14 can be used to deflect the light 6 passing through the projection lens 5 into a region above the light-dark boundary in order to realize the OS function. This makes it possible to: on the one hand reduce undesired glare in the forward direction, and on the other hand increase the overhead marking value. This is exemplified in Fig. 9 and Fig.10 Indicated in.

[0044] Fig. 9 The low beam distribution 19 produced by a projection lens 5 having a Fresnel structure 9 in which no refractive structure 14 is integrated is shown. The low beam distribution 19 has a relatively high luminous intensity in a region 20 directly above the light-dark boundary 21, while in a further upper region 22, in which the overhead marking value must be met, only a very low luminous intensity is achieved. As a result, undesired glare occurs in the region 20 in the forward direction, while in the region 22 arranged further up, only a very low overhead marking value is achieved.

[0045] Fig.10 The low beam distribution 23 produced by the projection lens 5 with the refractive structure 14 integrated into the Fresnel structure 9 is shown. The low beam distribution 23 has a reduced luminous intensity in the region 20 directly above the light-dark boundary 21, while a significantly greater luminous intensity is achieved in the region 22 located further up. As a result, less undesired glare occurs in the region 20 in the forward direction, while the value of overhead signs in the region 22 located further up is significantly increased.

[0046] It is entirely possible for the refractive structure 14 to be arranged not on the outcoupling side 8 of the projection lens 5 , but on the incoupling side 7 of the projection lens 5 .

[0047] Figure 7 A projection lens 5 is shown which does not have a Fresnel structure but is designed as a lens, in particular as a plano-convex aspherical lens.

[0048] Figure 8 Shown in its shape and according to Figure 7 However, a refractive structure 14 is integrated in the projection lens 5, which is used to deflect the light passing through the projection lens 5 to a region above the light-dark boundary for realizing the OS function. Here, the refractive structure 14 can be constructed as Figures 2 to 6 The structure 14 of the embodiment of the present invention is similar or identical. In particular, the structure 14 includes structural elements, at least one of which is configured to be annular or partially annular.

[0049] In accordance with Figure 8 In the embodiment of the invention, the refractive structure 14 is arranged on the coupling side 7 of the projection lens 5, in particular on the flat coupling side 7. It is entirely possible that the refractive structure 14 is arranged on the coupling side 8 of the projection lens 5, in particular on the convex coupling side.

[0050] Reference numerals list

[0051] 1 Light Source

[0052] 2 Primary Optics

[0053] 3Optical components of primary optics

[0054] 4 Secondary Optics

[0055] 5. Projection lens for secondary optics

[0056] 6Light from the source

[0057] 7Incoupling side of the projection lens

[0058] 8Outcoupling side of projection lens

[0059] 9Fresnel structure of projection lens

[0060] 10Fresnel structure circular steps

[0061] 11 Useful aspects of Fresnel structures

[0062] 12 Interference side of Fresnel structure

[0063] 13The optical axis of the lens formed by the Fresnel structure

[0064] 14Refraction structure for implementing OS functions

[0065] 15 Segment of the outcoupling side of the projection lens

[0066] 16 Structural elements of refractive structures

[0067] 17 Useful aspects of refractive structures

[0068] 18 Interference side of the refractive structure

[0069] 19 Low beam distribution produced by a projection lens having a Fresnel structure in which no refractive structure is integrated

[0070] 20 The area directly above the light-dark boundary of the low beam distribution

[0071] 21 Low beam distribution light and dark boundary

[0072] 22 The area where the low beam distribution must meet the elevated sign value

[0073] 23 Low beam distribution produced by a projection lens with a refractive structure integrated into the Fresnel structure

[0074] a Width of the structural elements of the refractive structure in the radial direction

[0075] Angle of attack of the useful side of the α Fresnel structure

[0076] α' Angle of attack of the useful side of the refractive structure

[0077] Attack angle of the interfering side of the β Fresnel structure

[0078] Attack angle of the interfering side of the β' refractive structure

Claims

1. A headlamp for a motor vehicle, comprising: - at least one light source (1), - an optical device having a plurality of optical components, the optical device being configured to shape the light originating from the at least one light source and to project it into the exterior of the motor vehicle so as to generate a low-beam light distribution (23) of the headlight, the low-beam light distribution having a light-dark boundary (21) and a light portion arranged above the light-dark boundary (21) for realizing an OS function, - at least one refractive structure (14), which is arranged on at least one of the optical components and has a plurality of structural elements (16), wherein the structure (14) is provided for deflecting light passing through the optical component into a region above the light-dark boundary (21) for the purpose of realizing an OS function, It is characterized in that at least one of the structural elements (16) is designed to be annular or partially annular.

2. The headlamp according to claim 1, characterized in that: A plurality of structure elements, preferably all structure elements, of the structure elements (16) of the refractive structure (14) are designed to be annular or partially annular.

3. The headlamp according to claim 1 or 2, characterized in that: The structural elements (16) configured in an annular or partially annular shape are arranged coaxially or concentrically with each other.

4. The headlamp according to any one of claims 1 to 3, characterized in that The diameter of a first structural element (16) in the annular or partially annular structure is smaller than the diameter of a second structural element (16) in the annular or partially annular structure.

5. The headlamp according to any one of claims 1 to 4, characterized in that: At least one of the structure elements (16) is designed to be partially annular, so that the at least one structure element extends over less than 360° in the circumferential direction, in particular only over a sector of a circle.

6. The headlamp according to any one of claims 1 to 5, characterized in that The structural elements (16) of the at least one structure (14) have a width (b) between 0.5 mm and 1.0 mm.

7. The headlamp according to any one of claims 1 to 6, characterized in that At least one of the optical components is designed as a lens, in particular as an aspherical lens, into which the refractive structure (14) is integrated.

8. The headlamp according to any one of claims 1 to 6, characterized in that At least one of the optical components is designed as a lens having a Fresnel structure (9), the refractive structure (14) being integrated into the Fresnel structure (9).

9. The headlamp according to claim 8, characterized in that: The Fresnel structure (9) comprises an annular step (10), wherein the step (10) has a useful side surface (11) and an interfering side surface (12), wherein the useful side surface (11) is a region of the step (10) which is configured to allow light to pass through the region, and the interfering side surface (12) is a region of the step (10) which is not configured to allow light to pass through the region, and both the useful side surface (11) and the interfering side surface (12) of the Fresnel structure (9) form an angle of attack (α, β) with the optical axis (13) of the lens.

10. The headlamp according to claim 9, characterized in that: The integration of the refractive structure (14) into the Fresnel structure (9) causes a partial change in the angle of attack (β) of the interfering side (12) of the Fresnel structure (9); in particular, the useful side (11) of the Fresnel structure (9) is not changed by the integration of the refractive structure (14) into the Fresnel structure (9).

11. The headlamp according to any one of claims 1 to 10, characterized in that The headlamp comprises a primary optical system (2) and a secondary optical system (4), in particular, the primary optical system (2) is configured to shape light (6) originating from the at least one light source (1) so as to generate an extended light distribution, and the secondary optical system (4) is configured to convert the extended light distribution generated by the primary optical system (2) into a light distribution corresponding to a low-beam light distribution (23) of the headlamp.

12. The headlamp according to claim 11, characterized in that: The secondary optical system (4) has a projection lens (5).

13. The headlamp according to claim 12, characterized in that: The refractive structure (14) is arranged on a projection lens (5) of a secondary optical device (4).

14. The headlamp according to claim 13, characterized in that: The refractive structure (14) is integrated into the coupling-in side (7) or coupling-out side (8) of the projection lens (5) of the secondary optics (4).

15. Method for producing an optical component of a headlamp according to any one of claims 1 to 14, wherein: A refractive structure (14) is arranged on the optical component, and is used to deflect light passing through the optical component to a region above a light-dark boundary (21) in order to realize an OS function. The optical component is manufactured from plastic by injection molding, and the refractive structure (14) is produced together during the injection molding.

Images