ILLUMINATION DEVICE FOR A MOTOR VEHICLE HEADLIGHT

Description

[0001] The invention relates to a lighting device for a motor vehicle headlight for generating an asymmetrical low beam light distribution, wherein the low beam light distribution has a homogeneous light distribution in the area below the intersection point HV of the horizontal line HH and the vertical line VV of a measuring screen for measuring a light distribution up to at least -3° along the vertical line VV, wherein the lighting device comprises the following: a light source for emitting light, a diaphragm with a diaphragm edge, wherein the diaphragm is arranged such that the diaphragm edge contributes to generating an asymmetrical low beam light distribution, and wherein the diaphragm comprises a first and a second diaphragm section, wherein the second diaphragm section is arranged higher than the first diaphragm section - seen in a correctly installed state of the lighting device in a motor vehicle - and wherein the first and the second diaphragm sections are connected to one another by a connecting section of the diaphragm, a projection optics system comprising an optical axis, which projection optics system is configured to image the low beam light distribution generated by the diaphragm in combination with the light source in the direction of a main emission direction in front of the lighting device.

[0002] Furthermore, the invention relates to a motor vehicle headlight comprising at least one lighting device according to the invention.

[0003] Typically, apertures with an aperture edge for generating a low beam light distribution in lighting devices are designed in such a way that the upper side reflects and deflects light emitted by the lamp.

[0004] In particular, the connecting section of the aperture ensures that light is deflected in such a way that it is no longer directed onto the projection optics system and is therefore missing for the generation or formation of the low beam light distribution.

[0005] Especially in the area below the cut-off line in the vicinity of the intersection point HV, i.e. below the asymmetric rise or at the beginning of the rise of the low beam light distribution, inhomogeneities occur, which leads to a shadow area below the intersection point HV.

[0006] The term "homogeneous" in this context means the absence of sudden changes between light and dark areas in the light distribution.

[0007] DE 10 2008 015246 A1 and US 2008 / 239741 A1 disclose known lighting devices for a motor vehicle headlight.

[0008] It is an object of the invention to provide an improved lighting device.

[0009] This problem is solved by the features of claim 1.

[0010] It can be provided that the longitudinal extension of the connecting section along the main radiation direction is one third, preferably one quarter, of the focal length of the projection optical system.

[0011] All information on value ranges in this description is to be understood as including any and all sub-ranges thereof, e.g. the information 1 to 10 is to be understood as including all sub-ranges starting from the lower limit of 1 and the upper limit of 10, ie all sub-ranges begin with a lower limit of 1 or greater and end with an upper limit of 10 or less, e.g. 1 to 1.7, or 3.2 to 8.1, or 5.5 to 10.

[0012] The "main radiation direction" is the direction in which the lamp emits the most light due to its directivity.

[0013] Advantageously, the main radiation direction coincides with the optical axis of the projection optics system.

[0014] It can be provided that the diaphragm edge has an asymmetry edge which contributes to generating the asymmetrical increase in the low beam light distribution, wherein the end edge of the deflection surface forms the asymmetry edge of the diaphragm edge.

[0015] It can be provided that the first and the second aperture section each extend substantially in a horizontal plane - seen in a correctly installed state of the lighting device in a motor vehicle - wherein the first and the second aperture section have an offset along a second virtual axis, wherein the second virtual axis is arranged orthogonal to the first virtual axis and the main radiation direction.

[0016] It can be provided that the light source is formed from several light-emitting diodes.

[0017] It can be provided that the illuminant comprises one or more attachment optics, preferably collimators for parallelizing light rays.

[0018] It can be provided that the area of ​​homogeneous light distribution in the low beam light distribution below the intersection point HV extends along the horizontal line HH from at least -4° to at least +4°.

[0019] The object is also achieved by a motor vehicle headlight comprising at least one lighting device according to the invention.

[0020] The invention is explained in more detail below with reference to exemplary drawings. Fig. 1 a side view of an exemplary lighting device, comprising a lamp, a diaphragm and a projection optics system, wherein the lamp in combination with the diaphragm produces a low beam light distribution which is imaged by the projection optics system in the direction of a main emission direction in front of the lighting device, Fig. 2 the lighting device from Fig. 1 in a perspective, rear (lamp-side along the direction of the main beam direction) view from above; Fig. 3 a perspective view of the panel from the example from Fig. 1, wherein the diaphragm has a diaphragm edge which contributes to generating the low beam light distribution, wherein the diaphragm has a first and a second diaphragm section which are connected to one another by a connecting section, and wherein the connecting section has a deflection surface which is designed to deflect at least a part of the light of the illuminant which is incident on the deflection surface onto the projection optical system, Fig. 4 a perspective view of the diaphragm from Fig. 3from behind, wherein the deflection surface extends along a plane which has a surface vector which encloses an angle to the main radiation direction and to a first virtual axis which is orthogonal to the main radiation direction and in a horizontal plane, Fig. 5 the first angle enclosed by the surface vector and the first virtual axis seen in the main radiation direction, Fig. 6 the second angle enclosed by the surface vector and the main radiation direction seen along the first virtual axis, wherein the main radiation direction points to the left, ie starting from a right-handed Cartesian coordinate system (where the main radiation direction corresponds to the x-axis) seen against the y-axis or against the positive direction of the y-axis, Fig.Fig. 7 shows a low-beam light distribution generated by a lighting device from the prior art, wherein the area below the intersection point HV is inhomogeneous, and Fig. 8 shows a low-beam light distribution generated by a lighting device according to the invention, wherein the area below the intersection point HV is homogeneous.

[0021] By way of introduction, it should be noted that in the variously described embodiments, identical parts are provided with identical reference symbols or component designations. The disclosures contained throughout the description can be applied analogously to identical parts with identical reference symbols or component designations. Furthermore, the positional information chosen in the description, such as top, bottom, side, etc., refers to the directly described and illustrated figure, and these positional information must be applied analogously to the new position in the event of a change in position.

[0022] Fig. 1 shows an exemplary lighting device 10 for a motor vehicle headlight for generating an asymmetrical low beam light distribution 50, where the low beam light distribution 50 a homogeneous light distribution in the area 51 below the intersection point HV of the horizontal line HH and the vertical line VV of a measuring screen for measuring a light distribution of at least -3° along the vertical line VV.

[0023] The lighting device 10 includes a light source 100 to emit light, whereby in the example shown the light source 100 than several light-emitting diodes. Of course, the light source can also be designed differently. In particular, the light source can 100have a plurality of LEDs arranged next to and / or one above the other in a matrix. The LEDs are preferably individually controllable, so that they can be individually switched on and off and / or dimmed. The LEDs are preferably controlled automatically (e.g., by a control unit).

[0024] Furthermore, the lighting device comprises 10 an aperture 200 with a bezel edge 200a, where the aperture 200 is arranged in such a way that the aperture edge 200a to create an asymmetrical low beam light distribution 50 participates.

[0025] The aperture 200 comprises a first and a second aperture section 210, 220, which, among other things, Fig. 2 can be seen. The second aperture section 220 is to the first aperture section 210- seen in a correctly installed state of the lighting device in a motor vehicle - arranged in a raised position, wherein the first and second aperture sections 210, 220 through a connecting section 230 the aperture 200 are connected to each other.

[0026] Furthermore, the lighting device comprises 10 a projection optics system 300, which is set up to pass through the aperture 200 Low beam light distribution generated in combination with the lamp 50 in the direction of a main radiation direction X in front of the lighting device 10 The projection optics system 300 In the example shown, it is designed as a projection lens. The projection lens or the projection optics system 300 projects an image of a light source inside the lighting device 10 in the area of ​​a focal area (e.g. a focal plane) of the projection optics system300 generated low beam light distribution in front of the lighting device 10.

[0027] The aperture 200 is rigid, with the aperture edge 200a in the focal area of ​​the projection optics system 300 (a focal plane or focal point or a focal point cloud or Petzval surface).

[0028] Fig. 3 shows the aperture 200 in a perspective view, where it can be seen that the connecting section 230 the aperture a deflection surface 240 with an end edge 241 which end edge 241 a section of the aperture edge 200a the aperture 200 forms.

[0029] As shown in the figures, especially in Fig. 3 can be seen, the aperture edge 200a the aperture 200has an asymmetry edge which is used to generate the asymmetrical increase in the low beam light distribution 50 contributes, whereby the end edge 241 the deflection surface 240 this asymmetry edge of the aperture edge 200a forms.

[0030] The first and second aperture sections 210, 220 each extend - seen in a correctly installed state of the lighting device in a motor vehicle - substantially in a horizontal plane, wherein the first and the second diaphragm section 210, 220 have an offset along a second virtual axis z, wherein the second virtual axis z is orthogonal to the first virtual axis y and the main radiation direction X Furthermore, the deflection surface comprises 240 a side edge 242, which the second aperture section 220 limited in sections and the end edge 241 cuts, whereby the side edge242 a third angle W3 with the optical axis A of the projection optics system 300 from 15° to 20°. The aperture 200 is in the optical axis A located, with the projection optics system 300 is arranged such that the optical axis A intersects the intersection point HV of the measuring screen.

[0031] The one in the main radiation direction X considered left section or the first aperture section 210 is, as already described, slightly below a right section or the second aperture section 220 The connecting section 230 connects the two sections with each other, creating a step or a slanted transition between the sections.

[0032] The longitudinal extension of the connecting section 230along the main emission direction is one third of the focal length of the projection optics system 300 in the figures shown.

[0033] Through the front edge of the left section or the edge of the first aperture section 210 is used to generate a low beam light distribution after imaging by the projection optics system 300 a raised section of the asymmetrical light-dark border on the own side of the road in right-hand traffic. Accordingly, the front edge or edge of the second aperture section 220 a lowered section of the asymmetrical light-dark boundary on the oncoming traffic side.

[0034] To the main radiation direction X a first virtual axis y is arranged orthogonally, wherein the first virtual axis y- seen in a correctly installed state of the lighting device in a motor vehicle - is arranged in a horizontal plane, for example as seen in Fig. 2 or Fig. 4 .

[0035] The deflection surface 240 extends along a flat plane, where the plane has an area vector A as in Fig. 4 can be seen. The area vector A closes seen in the main radiation direction X a first angle W1 from 1° to 3°, preferably from 2°, to the first axis y what in Fig. 5 is shown.

[0036] Furthermore, the area vector A seen along the first axis y a second angle W2 from 1° to 3°, preferably 2°, to the main radiation direction X to dim at least part of the light from the lamp 100, which is applied to the deflection surface 240incident, towards the area 51 below the intersection point HV to at least -3° along the vertical line VV. As in Fig. 6 can be seen, shows the main radiation direction X to the left, ie starting from a right-handed Cartesian coordinate system (where the main radiation direction X corresponds to the x-axis) is viewed against the y-axis or against the positive direction of the y-axis.

[0037] Fig. 7 shows a low beam light distribution 50 generated by a prior art lighting device, showing that the area 51 below the intersection point HV is inhomogeneous. The area 51 can be reflected in the low beam light distribution 50 below the intersection point HV along the horizontal line HH from at least -3° to at least +3°.

[0038] Fig. 8 shows a low beam light distribution 50generated by a lighting device according to the invention 10, where it can be seen that the area 51 below the intersection point HV compared to Fig. 7 is homogeneous. LIST OF REFERENCE SYMBOLS Lighting device... 10 Low beam light distribution... 50 Area... 51 Light bulbs... 100 Aperture... 200 Aperture edge... 200a First aperture section... 210 Second aperture section... 220 Connecting section... 230 Deflection surface... 240 End edge... 241 Side edge... 242 Projection optics system... 300 Main radiation direction... X Virtual axis... y Area vector ... A First angle... W1 Second angle... W2 Third angle... W3

Claims

1. Lighting device (10) for a motor vehicle headlamp for producing an asymmetrical low beam light distribution (50), the low beam light distribution (50) having a homogeneous light distribution in the region (51) below the intersection HV of the horizontal line H-H and the vertical line V-V of a measuring screen for measuring a light distribution up to at least -3° along the vertical line V-V, the lighting device (10) comprising the following - a light source (100) for emitting light, - a diaphragm (200) having a diaphragm edge (200a), wherein the diaphragm (200) is arranged such that the diaphragm edge (200a) cooperates to produce an asymmetric low beam light distribution (50), and wherein the diaphragm (200) comprises a first and a second diaphragm section (210, 220), wherein the second diaphragm section (220) is elevated relative to the first diaphragm section (210), as seen in a correctly installed state of the lighting device in a motor vehicle, and wherein the first and second diaphragm sections (210, 220) are connected to each other by a connecting section (230) of the diaphragm (200), - a projection optics system (300) comprising an optical axis (A), which projection optics system (300) is set up to image the low beam light distribution (50) generated by the diaphragm (200) in combination with the light source in the direction of a main radiation direction (X) in front of the lighting device (10), the connecting section (230) of the diaphragm has a deflecting surface (240) with an end edge (241), which end edge (241) forms a section of the diaphragm edge (200a) of the diaphragm (200), wherein a first virtual axis (y) is arranged orthogonally to the main radiation direction (X), wherein the first virtual axis (y) - viewed in a correctly installed state of the lighting device - is arranged in a horizontal plane, characterized in that the deflection surface (240) extends along a plane, the plane having a surface vector (A), which surface vector (A) includes a first angle (W1) of 1° to 3°, preferably of 2°, relative to the first axis (y) when viewed in the main radiation direction (X), and a second angle (W2) of 1° to 3°, preferably of 2°, relative to the first axis (y) when viewed along the first axis (y), preferably of 2°, to the main radiation direction (X) in order to direct at least part of the light of the illuminant (100), which is incident on the deflection surface (240), in the direction of the region (51) below the intersection point HV to at least -3° along the vertical line V-V.

2. Lighting device according to claim 1, characterized in that the diaphragm edge (200a) has an asymmetrical edge which contributes to generating the asymmetrical rise in the low beam light distribution (50), the end edge (241) of the deflection surface (240) forming the asymmetrical edge of the diaphragm edge (200a).

3. Lighting device according to claim 1 or 2, characterized in that the first and the second aperture sections (210, 220) each extend - as seen in a correctly installed state of the lighting device in a motor vehicle - essentially in a horizontal plane, the first and the second aperture sections (210, 220) having an offset along a second virtual axis (z), the second virtual axis (z) being arranged orthogonally to the first virtual axis (y) and the main radiation direction (X).

4. Lighting device according to one of claims 1 to 3, characterized in that the deflection surface has a side edge (242) which delimits the second aperture section (220) in sections and intersects the end edge (241), the side edge (242) enclosing a third angle (W3) with the optical axis (A) of the projection optics system (300) of 15° to 20°.

5. Lighting device according to one of claims 1 to 4, characterized in that the longitudinal extent of the connecting section (230) along the main radiation direction (X) is at least one third, preferably at least one quarter, of the focal length of the projection optics system (300).

6. Lighting device according to one of claims 1 to 5, characterized in that the light source (100) is formed from a plurality of light-emitting diodes.

7. Lighting device according to one of claims 1 to 6, characterized in that the light source (100) comprises one or more attachment optics, preferably collimators for parallelizing light beams.

8. Lighting device according to one of claims 1 to 4, characterized in that the region (51) of the homogeneous light distribution in the low beam light distribution (50) below the intersection point HV extends along the horizontal line H-H from at least -4° to at least +4°.

9. Motor vehicle headlamp comprising at least one lighting device (10) according to any one of claims 1 to 8.