HEADLAMP FOR VEHICLES

Abstract

The invention relates to a headlamp for vehicles comprising an imaging unit and comprising an optical unit for generating a predefined light distribution, which has a plurality of light spots, the lights each being produced by projection of at least one light pixel of the imaging unit, and comprising a control unit containing a control signal for controlling the light pixels of the imaging unit and/or for controlling optical elements of the optical unit arranged upstream of the light pixels, a light focal point of the light distribution being arranged displaceably depending on the control signal, and the control signal being designed in such a way that the light focal point is arranged in a right edge region and/or left edge region of the light distribution.

Claims

1. A headlamp for vehicles comprising: an imaging unit comprising an optical unit for generating a light distribution, which has a plurality of light spots, each of the plurality of light spots being produced by projection of at least one of a plurality of light pixels of the imaging unit; and a control unit configured to generate a control signal for controlling the plurality of light pixels or for controlling optical elements of the optical unit arranged upstream of the plurality of light pixels, wherein a light focal point of the light distribution is displaceable depending on the control signal, and wherein the control signal causes the light focal point to be arranged in a right edge region or a left edge region of the light distribution.

2. The headlamp of claim 1, wherein the edge region of the light distribution is located outside a carriageway of the vehicle.

3. The headlamp of claim 1, the control signal causes the light distribution to have illumination fields arranged in a fan shape on a measuring wall, wherein an illumination field in the right edge region or left edge region has a greater light intensity than an illumination field in a central area of the light distribution.

4. The headlamp of claim 3, wherein the control signal causes the plurality of light spots in the illumination fields to have an increasing illumination level in a horizontal direction or in a direction of a light/dark boundary.

5. The headlamp of claim 4, wherein each of the plurality of light spots have an illumination level, and wherein the control signal causes the illumination level of the plurality of light spots close to the light/dark boundary, which are arranged in the right edge region or the left edge region of the light distribution, to be greater than the illumination level of the plurality of light spots located in the central area of the light distribution.

6. The headlamp of claim 5, wherein the control signal causes isolines of light spots close to the light/dark boundary, which are arranged in the right edge region or the left edge region of the light distribution, extending exclusively in the right edge region or the left edge region.

7. The headlamp of claim 1, wherein the control signal causes a transition gradient between a right end illumination field and a central illumination field or a transition gradient between a left end illumination field and the central illumination field.

8. The headlamp of claim 1, wherein the plurality of light spots define an illumination level, and wherein the control signal causes a transition gradient of the illumination level in a transition region between a right edge illumination field and a central illumination field to be greater than a transition gradient of the illumination level in a transition region between a left end illumination field and the central illumination field.

9. The headlamp of claim 1, wherein the vehicle defines a vehicle track, and wherein a boundary edge between an illumination field in a left edge region and a neighboring illumination field in front of the vehicle extends along an edge of the vehicle track.

10. The headlamp of claim 1, wherein the vehicle defines a vehicle track, and a detection unit is provided for detecting an edge of the vehicle track; and the control signal is generated depending on a detection signal of the detection unit, so that a boundary edge between the right edge region or the left edge region and a neighboring illumination field coincides with the edge of the vehicle track.

11. The headlamp of claim 1, wherein the light distribution defines a width that extends in an angle range between +45 and 60 in a horizontal direction.

12. The headlamp of claim 1, wherein the light distribution defines an illumination field, and wherein the illumination field at the left edge region or the right edge region of the light distribution comprises a light/dark boundary section facing horizontal, the light spots of which have an illumination level which decreases continuously in a horizontal direction.

13. The headlamp of claim 1, wherein the light/dark boundary section extends away from a central area to the left edge region or the right edge region, forming an enlarged vertical width.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] One embodiment of the invention is elucidated in more detail below with reference to the drawings. Wherein:

[0017] FIG. 1 shows a block diagram of a headlamp according to the invention;

[0018] FIG. 2 shows a schematic representation of an illumination of an area in the front of the vehicle;

[0019] FIG. 3 shows a schematic representation of a light distribution L.sub.1 on a measurement screen for generation of a city light distribution; and

[0020] FIG. 4 shows a schematic representation of a light distribution L.sub.2 on a measurement screen for generation of a country road light distribution.

DETAILED DESCRIPTION OF THE CURRENT EMBODIMENTS

[0021] A headlamp according to the invention is arranged in a front area of the vehicle and can be used to generate different light distributions L.sub.1, L.sub.2. By way of example, the headlamp can be used to generate a city light distribution L.sub.1 or a country road light distribution L.sub.2 or to generate a highway light distribution.

[0022] The headlamp substantially consists of an imaging unit 1, an optical unit 2 and a control unit 3.

[0023] The imaging unit 1 substantially consists of a matrix of individually controllable light sources 4, for example LED light sources, which are preferably arranged on a common circuit board. By way of example, the imaging unit 1 can comprise 30,000 light sources 4, so that different light distributions, for example low beam light distribution, high beam light distribution and the like, can be generated by controlling them individually, which is to say, moving them into an on or off state or into a dimming state. In the present embodiment example, the imaging unit 1 is controlled by means of a control signal 5 generated by the control unit 3 in such a way that the light pixels formed by the individual light sources 4 are mapped by the optical unit 2 to form light spots of a city light distribution L.sub.1. In so doing, the light spots are preferably arranged next to each other or, if necessary, neighboring light spots overlap each other. The city light distribution L.sub.1 is, for example, visible on a measurement screen.

[0024] The optical unit 2 can, for example, comprise a lens arrangement.

[0025] The control unit 3 receives a detection signal 7 from a detection unit 6, which is evaluated in the control unit 3 to determine whether the vehicle with the headlamp according to the invention is driving in a city. The detection unit 6 is installed in the vehicle carrying the headlamp and can, for example, be configured as a camera that supplies image information as the detection signal 5. If necessary, further parameters or operating parameters of the vehicle can be evaluated in order to recognize the presence of a drive through the city. In such a case, the light pixels 4 of the imaging unit 1 are controlled by the control signal 5 in such a way that the city driving illumination 8 shown in FIG. 2, which corresponds to the city light distribution L.sub.1 on a measurement screen, is generated. If no city driving and/or no street lighting or alternatively town situation is detected, a different light function is generated depending on the driving situation of the vehicle and/or the ambient conditions, for example, a low beam light function, a non-blinding high beam light function, a highway light function or similar.

[0026] The city light distribution L.sub.1 or city driving illumination 8 provided according to the invention as shown in FIG. 2 and FIG. 3 differs from the conventional city light distribution or alternatively conventional city driving illumination in that the control signal 5 acts on the imaging unit 1 in such a way that a light focal point S.sub.R, S.sub.L is arranged in a right and/or left edge region R.sub.R, R.sub.L of the light distribution L.sub.1 or alternatively city driving illumination 8. In the present embodiment example, a left light focal point S.sub.L is located in a left edge region R.sub.L when viewed horizontally and a right light focal point S.sub.R is located in a right edge region R.sub.R of the light distribution L.sub.1 or alternatively city driving illumination 8 (area in the front of the vehicle) when viewed horizontally.

[0027] The left edge region R.sub.L and the right edge region R.sub.R of the light distribution L.sub.1 or alternatively city driving illumination 8 are respectively located outside a carriageway 9, which is delimited by edge-side lane markings 10. The edge regions R.sub.L and R.sub.R of the city light distribution therefore, for example, illuminate a sidewalk or cycle path when driving through the city. The maximum illumination level of the left half or the right half of the light distribution L.sub.1 (city driving illumination 8) is located in these edge regions R.sub.L and R.sub.R.

[0028] As can be seen from FIG. 2, the city driving illumination 8 consists of a plurality of illumination fields 12, 13, 13, 14, 15 arranged in a fan shape, in each of which light spots are preferably arranged with the same illumination level. A central illumination field 12 is arranged in a central area M of the city light distribution L.sub.1 or alternatively of the city driving illumination 8. A longitudinal central plane or alternatively a longitudinal central axis of the vehicle runs in this central illumination field 12. On the left side of the illumination field 12, there is an adjoining transitional illumination field 13 (longitudinal hatching in FIG. 2), which in turn is adjoined on a side facing away from the central illumination field 12 by a left end illumination field 14 (cross-hatching in FIG. 2). The left illumination field 14 is located in a left edge region R.sub.L of the light distribution L.sub.1 or alternatively city driving illumination 8.

[0029] On the right side of the central illumination field 12, there is an adjoining transitional illumination field 13 (longitudinal hatching in FIG. 2), which in turn is adjoined on a side facing away from the central illumination field 12 by a right end illumination field 15 (cross-hatching in FIG. 2). The right illumination field 15 is located in a right edge region R.sub.R of the light distribution L.sub.1 or alternatively city driving illumination 8.

[0030] The central illumination field 12 has light spots with the lowest illumination level. The left end illumination field 14 and the right end illumination field 15 have light spots with the highest illumination level. The transitional illumination fields 13, 13 have light spots, the illumination level of which is stronger than that of the central illumination field 12, but lesser than the illumination level of the left end illumination field 14 and the right end illumination field 15.

[0031] It can be seen that neighboring illumination fields 12, 13, 13, 14, 15 have light spots of different illumination level.

[0032] FIG. 3 shows that a left light focal point S.sub.L is located in the left end illumination field 14 and a right light focal point S.sub.R is located in the right end illumination field 15. It can be seen that a light/dark boundary HDG of the light distribution L.sub.1 extends in the left edge region 14 and in the right edge region 15 in an area close to the horizontal H, whereas in the center area 12 it extends away from the horizontal H. Light spots of the left illumination field 14 and of the right illumination field 15, which are located in an area close to the light/dark boundary HDG, have a greater illumination level than the light spots of the center illumination field 12, which are located in an area close to the light/dark boundary HDG. This is made clear in FIG. 3 by the course of isolines 60 lx, which are marked with the reference numbers 16 and 17, and the course of the isolines 40 lx, which are marked with the reference numbers 18 and 19. The isoline 20 of the central area close to the light/dark boundary HDG only has an illumination level of 20 lx.

[0033] It is understood that within the illumination fields 12, 13, 13, 14, 15, the illumination level of the light spots increases in the direction of the horizontal H or light/dark boundary HDG, so that a homogeneous light distribution is ensured over the depth of the area in the front of the vehicle.

[0034] As can be seen from FIG. 2, the illumination fields 12, 13, 13, 14, 15 taper in the direction of the light/dark boundary HDG or in the direction of a central point of the light distribution L.sub.1 or alternatively of the city driving illumination 8.

[0035] FIG. 3 also shows that illumination level transitions between the peripheral illumination fields 14, 15 on the one hand and the central illumination field 12 on the other, which is to say, in the transitional illumination fields 13, 13, do not occur abruptly, but rather according to a gradient G.sub.1 with a comparatively mild pitch (mild pitch in terms of amount). This ensures a smooth transition between the end illumination fields 14, 15 on the one hand and the central illumination field 12 on the other. This smooth transition extends substantially in the transitional illumination fields 13, 13.

[0036] Preferably, the illumination level transitions between the illumination fields 12, 13, 13, 14, 15 are not abrupt, but rather extend along a curved or straight line with a comparatively mild pitch. In this way, a smooth transition is created between the neighboring illumination fields 12, 13, 13, 14, 15.

[0037] FIG. 2 also shows that a left boundary edge kL, which extends between the left end illumination field 14 and the left transitional illumination field 13, and a right boundary edge kR, which extends between the right end illumination field 15 and the right transitional illumination field 13, sweep over the vehicle marking 10 on the edge of the carriageway 9. This means that the carriageway 9 is less strongly illuminated than the left edge region R.sub.L and the right edge region R.sub.R, which are located outside the carriageway 9.

[0038] FIG. 2 also shows that a central lane marking 21, which extends in the middle of the carriageway 9, falls in the left transitional illumination field 13.

[0039] The city light distribution L.sub.1 according to the invention has an increased illumination width in the horizontal direction compared to conventional city light distributions. In relation to a vertical V, a left illumination width section extends up to an angle .sub.1 of 60 and a right illumination width section extends up to an angle .sub.2 of 45. The illumination width therefore extends from +45 to 60.

[0040] A light/dark boundary HDG of the light distribution L.sub.1 or alternatively of the city driving illumination 8 is substantially formed by the left end illumination field 14 and the right end illumination field 15. In order that a pitching movement of the vehicle caused by unevenness of the carriageway 9 does not have a disturbing effect on the driver, the illumination level of the light spots facing the horizontal H is reduced in such a way that the left illumination field 14 and the right illumination field 15 transition to the horizontal H under a relatively flat illumination level gradient G.sub.1. This means that the illumination level of the end illumination fields 14, 15 is gradually and/or continuously reduced in the direction of the horizontal H.

[0041] In the present embodiment example, the left end illumination field 14 and the right end illumination field 15 each have a light/dark boundary section 23, which extends with an increasing vertical width from the central area M to the edge region R.sub.L or R.sub.R.

[0042] According to an alternative embodiment of the invention, the width of the light/dark boundary section 23 can also be constant.

[0043] By way of example, if the detection unit 6 has detected a failure of the street lighting, the imaging unit 1 is controlled in such a way that a conventional city light distribution is generated in which the light focal point is located in the central area M. This ensures that the light distribution L.sub.1 according to the invention is only generated if there is actually additional external lighting in the carriageway.

[0044] According to an alternative embodiment of the invention not shown, the imaging unit 1 can also comprise other individually controllable light control elements, such as liquid crystal elements.

[0045] According to a further embodiment of the invention, the optical unit 2 can also comprise a micromirror unit, so that the light distribution is generated depending on the position of the micromirrors arranged in a matrix.

[0046] Alternatively, the left end illumination field 14 or the right end illumination field 15 can also be missing in the light distribution L.sub.1 or in the city illumination 8.

[0047] The substantial difference between a country road light distribution L.sub.2 shown in FIG. 4 and the city light distribution L.sub.1 shown in FIG. 3 is that in a transition area between the right end illumination field 15 and the central illumination field 12, the transition takes place with a relatively abrupt transition light gradient G.sub.2. This ensures greater illumination of the right-hand area in the front of the vehicle.

LIST OF REFERENCE NUMERALS

[0048] 1 imaging unit [0049] 2 optical unit [0050] 3 control unit [0051] 4 light sources [0052] 5 control signal [0053] 6 detection unit [0054] 7 detection signal [0055] 8 city driving illumination [0056] 9 carriageway [0057] 10 edge-side lane marking [0058] 12 central illumination field [0059] 13, 13 transitional illumination fields [0060] 14 left end illumination field [0061] 15 right end illumination field [0062] 16 isoline [0063] 17 isoline [0064] 18 isoline [0065] 19 isoline [0066] 20 isoline [0067] 21 central lane marking [0068] HDG light/dark boundary [0069] 23 light/dark boundary section [0070] V vertical [0071] H horizontal [0072] .sub.1, .sub.2 angle [0073] M central area [0074] kL, kR boundary edge [0075] R.sub.L, R.sub.R edge region [0076] S.sub.L, S.sub.R light focal point [0077] L.sub.1, L.sub.2 light distribution [0078] G.sub.1, G.sub.2 transition gradient

[0079] The above description is that of current embodiment of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention. This disclosure is presented for illustrative purposes and should not be interpreted as an exhaustive description of all embodiments of the invention or to limit the scope of the claims to the specific elements illustrated or described in connection with these embodiments. Any reference to elements in the singular, for example, using the articles a, an, the, or said, is not to be construed as limiting the element to the singular.