Lighting device for motor vehicle headlight

Abstract

A lighting device (10) for motor vehicle headlights, comprising: a first optical module (100) for generating a light distribution; a beam baffle (400) including optically correlated baffle edges (410) for generating light and dark boundaries; and a projection lens (300) with an optical axis (A) configured to image light generated by the first optical module (100) in front of the lighting device (10), wherein the projection lens (300) is constructed as a Fresnel lens, the Fresnel lens including a substrate (310) and a plurality of annular stepped portions arranged at the substrate (310). 320), wherein each stepped portion (320) has a main surface (320a) for projecting a beam of light from at least one optical module (100) onto an illumination device (10) and a slope (320b) extending from the substrate (310) to the main surface (320a), wherein the main surface (320a) of each stepped portion (320) is curved and has a focal point (F1, F2, F3, F4), which is arranged horizontally and / or vertically by the optical axis of a Fresnel lens, and wherein adjacent stepped portions (320) have different focal points (F1, F2, F3, F4) from each other.

Description

Technical Field

[0001] This invention relates to a lighting device for motor vehicle headlights, the lighting device comprising the following:

[0002] - At least one first optical module, having at least one light source, for generating a light distribution along the main radiation direction, wherein the optical module is configured to emit a light beam along the main radiation direction.

[0003] - A projection lens, having an optical axis, configured to image light generated by a first optical module in front of an illumination device, wherein the projection lens is constructed as a Fresnel lens, the Fresnel lens comprising a substrate and a plurality of annular studs arranged concentrically on the substrate, wherein each stud has a main surface for projecting a beam from at least one optical module in front of the illumination device and an inclined surface extending from the substrate to the main surface.

[0004] - A beam baffle (sometimes also called a beam aperture or beam diaphragm), wherein the beam baffle includes optically associated baffle edges (sometimes also called aperture edges) for generating light and dark boundaries, wherein the baffle edges intersect the optical axis of a Fresnel lens, and wherein a first optical module is arranged on the upper side of the beam baffle and cooperates with the optically associated baffle edges of the beam baffle to generate a light distribution.

[0005] Furthermore, the present invention relates to a motor vehicle headlight having at least one lighting device according to the present invention. Background Technology

[0006] Fresnel lenses (more accurately: Fresnel step lenses) are optical lenses that enable the construction of large and thick lenses with shorter focal lengths without the weight and volume of traditional lenses.

[0007] The reduction in volume in a Fresnel lens is achieved by distributing the light across annular regions. In each of these regions, the thickness is reduced, resulting in a series of annular steps in the lens. Because light refracts only at the principal surface of the lens, the angle of refraction depends not on the thickness but only on the angle between the two surfaces of the lens. Therefore, the lens retains its optical properties, although image quality is compromised by the stepped structure, but this has no impact in many applications. An example of this is the illumination beam path in all types of headlights. Summary of the Invention

[0008] The objective of this invention is to provide an improved lighting device.

[0009] The task is solved by the following: each step portion is constructed with a curved main surface and has at least one focal point, which is arranged by the horizontal and / or vertical movement of the optical axis of the Fresnel lens, and wherein adjacent steps portions have different focal points from each other.

[0010] This can be configured, for example, so that each step or the main surface of the step has multiple sections, each with a different focal point. Thus, for example, it can be configured such that, viewed from the position where the lighting device is installed in a motor vehicle headlight, the upper half of the step has a different focal point than the lower half of the step.

[0011] Two light images (Lichtbilders) are generated in a distribution with, for example, two focal points (one above and one below the optical axis in the vertical direction or one of the baffle edges), which are vertically offset from each other. Therefore, it is applicable to light images that are horizontally offset from each other. In the overlap of these offset light images, blurring occurs, which is advantageous in compensating for color effects at light-dark boundaries and in the dissolving of light-dark boundaries.

[0012] Here, the light distribution can be moved along the horizontal and / or vertical directions from about 1 / 10° to several tenths of a degree (measured at a measurement screen corresponding to the legal framework conditions, such as a measurement screen in the sense of the ECE guidelines).

[0013] The concept of "optical axis" refers to an optical axis that is also the axis of symmetry of a Fresnel lens, that is, intersecting the Fresnel lens essentially at the center or midpoint.

[0014] Typically, in the following text, the concepts of position or orientation, such as “horizontal,” “vertical,” “horizontal,” “vertical,” “above,” “below,” “front,” “rear,” “below,” “above,” etc., refer to the compliant installation position of the independent projection module in the headlight of a motor vehicle.

[0015] Furthermore, it should be noted that the expression "arranged in a horizontal and / or vertical manner" includes movement in a horizontal or vertical plane, meaning that the focal point can also be arranged to move along or in the direction of the optical axis.

[0016] It can be configured such that the beam baffle has a longitudinal axis, wherein the longitudinal axis of the beam baffle is arranged in a horizontal plane when the lighting device is installed in the headlight of a motor vehicle, and wherein the optically related baffle edge is configured to generate an asymmetric light and dark boundary, and wherein the first optical module cooperates with the optically related baffle edge of the beam baffle to generate a near light distribution.

[0017] The lighting device may be configured to include at least one second light module with at least one light source for generating a far-beam distribution.

[0018] The near beam distribution and, for example, the connected high beam distribution form the total beam distribution, wherein the possible gaps between these beam distributions are also not clearly projected due to the moving focus, thereby closing the gaps that appear between the near beam distribution and the high beam distribution.

[0019] The second optical module can be positioned on the lower side of the beam baffle.

[0020] It can be configured such that the main surface of the stepped section is convex or concave.

[0021] The step portion can be configured such that the main surface and the inclined surface of the step portion form the edge of the step portion in a common intersection line, wherein the edge of the step portion has a distance of less than 20 μm, preferably less than 10 μm, and preferably less than 5 μm from the adjacent edge of the step portion.

[0022] This task is also solved by a motor vehicle headlight with at least one lighting device according to the invention. Attached Figure Description

[0023] The invention is then described in more detail with reference to exemplary drawings, herein:

[0024] Figure 1 A side view of an exemplary illumination device with a projection lens configured as a Fresnel lens is shown, wherein the Fresnel lens includes a plurality of substantially concentric stepped portions, and

[0025] Figure 2 Showing from Figure 1 A cross-sectional view of the stepped section of a Fresnel lens. Detailed Implementation

[0026] Figure 1 An exemplary lighting device 10 for motor vehicle headlights is shown, the lighting device including a first light module 100 having at least one light source for generating a low beam distribution along the main radiation direction, wherein the first light module 100 is configured to emit a beam along the main radiation direction.

[0027] In addition, the lighting device 10 includes a projection lens 300 with an optical axis A, which is configured to image light generated by the first light module 100 in front of the lighting device 10, wherein the projection lens 300 is constructed as a Fresnel lens.

[0028] The Fresnel lens includes a substrate 310 and a plurality of annular stepped portions 320 arranged on the substrate 310, the stepped portions 320 being substantially concentric with each other, wherein each stepped portion 320 has a main surface 320a for projecting a beam of light from at least one optical module 100 onto an illumination device 10 and a bevel 320b extending from the substrate 310 to the main surface 320a, as shown in Figure 2 This is more clearly visible in the middle.

[0029] Furthermore, the main surface 320a and the inclined surface 320b of the stepped portion 320 form the stepped portion edge 320c in a common intersection line, wherein the stepped portion edge 320c has a distance of less than 20μm, preferably less than 10μm, and preferably less than 5μm from the adjacent stepped portion edge 320c.

[0030] Additionally, the lighting device 10 includes a beam baffle 400 with a longitudinal axis, wherein the longitudinal axis of the beam baffle 400 is arranged in a horizontal plane when the lighting device 100 is installed in the headlight of a motor vehicle, wherein the beam baffle 400 includes an optically associated baffle edge 410 for generating asymmetric light and dark boundaries, wherein the baffle edge 410 intersects the optical axis A of the Fresnel lens.

[0031] The first optical module 100 is positioned above the beam baffle and cooperates with the optically related baffle edge 410 of the beam baffle 400 to generate near-light distribution.

[0032] Generally, in the following text, given the concepts of position or orientation, such as, for example, “horizontal,” “vertical,” “horizontal,” “vertical,” “above,” “below,” “front,” “rear,” “below,” “above,” etc., the compliant installation position of an independent lighting device in a motor vehicle headlight is referred to.

[0033] Each stepped portion 320 has a curved main surface 320a and has focal points F1, F2, F3, F4 respectively. These focal points F1, F2, F3, F4 are arranged horizontally and / or vertically by the optical axis A of the Fresnel lens, and adjacent stepped portions 320 have different focal points F1, F2, F3, F4 from each other.

[0034] As in Figure 1 As can be seen, the outermost step of the Fresnel lens is the focal point F1, and the innermost step is associated with the focal point F2, etc.

[0035] The curved main surface 320a of the stepped section can be convex or concave; in Figure 2 The exemplary stepped portion is constructed with a convex main surface 320a.

[0036] In addition, from Figure 1An exemplary lighting device includes a second light module 200 having at least one light source for generating a high beam distribution, wherein the second light module 200 is arranged on the underside of the beam baffle 400.

[0037] Reference Symbol List

[0038] 10 lighting fixtures

[0039] 100 First optical module

[0040] 200 Second optical module

[0041] 300 projection lens

[0042] 310 matrix

[0043] 320 steps

[0044] 320a Main Face

[0045] 320b inclined plane

[0046] 320c stepped edge

[0047] 400mm beam deflector

[0048] 410 Baffle edge

[0049] F1, F2, F3, F4 focus

Claims

1. A lighting device (10) for a motor vehicle headlight, the lighting device (10) comprising: - At least one first optical module (100) having at least one light source for generating a light distribution along the main radiation direction, wherein the first optical module (100) is configured to emit a light beam along the main radiation direction. - A projection lens (300) with an optical axis (A) configured to image light generated by the first optical module (100) in front of the illumination device (10), wherein the projection lens (300) is constructed as a Fresnel lens, the Fresnel lens comprising a base (310) and a plurality of annular stepped portions (320) arranged on the base (310), the stepped portions (320) being substantially concentrically arranged with each other, wherein each stepped portion (320) has a main surface (320a) for projecting the light beam of the at least one first optical module (100) onto the illumination device (10) in front of it and a slope (320b) extending from the base (310) to the main surface (320a). - A beam baffle (400), wherein the beam baffle (400) includes an optically associated baffle edge (410) for generating a light-dark boundary, wherein the baffle edge (410) intersects the optical axis (A) of the Fresnel lens, and wherein the first optical module (100) is disposed on the upper side of the beam baffle and cooperates with the optically associated baffle edge (410) of the beam baffle (400) to generate a light distribution. Its features are, Each step (320) has a curved main surface (320a) and at least one focal point (F1, F2, F3, F4) arranged horizontally and / or vertically by the optical axis (A) of the Fresnel lens, and adjacent steps (320) have different focal points (F1, F2, F3, F4) from each other.

2. The lighting device according to claim 1, characterized in that, The beam baffle has a longitudinal axis, wherein the longitudinal axis of the beam baffle (400) is arranged in a horizontal plane in the installed state of the lighting device (10) in the motor vehicle headlight, and wherein the optically associated baffle edge is configured to generate an asymmetrical light and dark boundary, and wherein the first light module (100) cooperates with the optically associated baffle edge (410) of the beam baffle (400) to generate a near light distribution.

3. The lighting device according to claim 1 or 2, characterized in that, The lighting device (10) includes at least one second light module (200) with at least one light source for generating a far-beam distribution.

4. The lighting device according to claim 3, characterized in that, The second optical module (200) is located on the lower side of the beam baffle (400).

5. The lighting device according to any one of claims 1 to 2, characterized in that, The main surface (320a) of the stepped portion (320) has a convex or concave structure.

6. The lighting device according to any one of claims 1 to 2, characterized in that, The main surface (320a) and the inclined surface (320b) of the stepped portion (320) form a stepped edge (320c) in a common intersection line, wherein the stepped edge (320c) has a spacing of less than 20 μm with the adjacent stepped edge (320c).

7. The lighting device according to claim 6, characterized in that, The spacing is less than 10 μm.

8. The lighting device according to claim 6, characterized in that, The spacing is less than 5 μm.

9. A motor vehicle headlight, having at least one lighting device (10) according to any one of claims 1 to 8.

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