EP3218645B1 - Individual headlight for a motor vehicle - Google Patents

Description

The invention relates to a single headlight for a motor vehicle, with at least one light source for emitting at least a first and a second light beam, and with a first and a second controllable deflection element for the respective variable deflection of the first and the second light beam into a respective first and second solid angle range on a given lighting area. The corresponding solid angle areas on the illumination surface correspond to the respective illuminated areas, which are illuminated by the respective light beams. The invention also relates to a motor vehicle with such a single headlight and a method for operating such a single headlight.

A beam of light is used in beam-guided individual headlights in order to travel over a predetermined lighting surface, that is to say to scan or scan, and thus to illuminate. The lighting surface can thus be excited to emit light, for example. The light beam is variably deflected via controllable deflection elements, so that individual points on the illumination surface are scanned in succession. Similarly, this is known from a cathode ray tube screen that is illuminated with an electron beam.

For example, the DE 10 2010 048 659 B4 a lighting device of a motor vehicle, with a light source, a micromirror arrangement, an absorber and at least one optical element. Light from the light source falls on the micromirror arrangement and is reflected by it, depending on the configuration of the micromirror arrangement, onto the absorber or onto an optical element.

The DE 10 2012 002 232 A1 describes a lighting device of a vehicle, with laser light sources and with optics for setting a light distribution, the laser light sources emitting laser light of the colors red, green or blue. The optics include two mirror systems, each with fixed or movable mirror elements. A mirror element of the first mirror system is assigned to the laser light sources, by means of which the laser light is deflected onto the second mirror system in such a way that the laser light reflected by the second mirror system appears white.

The DE 197 37 653 A1 describes a lighting device with a large number of electronically controllable micro mirrors which can be switched between two mirror settings and which form a mirror surface which is illuminated by a light source. By switching part of the micromirrors, a light distribution of a light leaving a light exit opening can be varied.

In the WO 2014/121 315 A1 a headlight for motor vehicles is described. The headlight comprises a first group of at least two laser sources and a second group of at least two laser sources. The first and the second group of laser sources each generate at least two light bands. The light strips are directed onto a light conversion means via a beam deflecting means.

From the WO 2014/121 314 A1 shows a headlight for a motor vehicle. In the headlamp, a modulated light beam is directed onto a light conversion means via a pivotable micromirror. The light image generated on the light conversion means is projected onto a roadway.

It is the object of the present invention to achieve improved illumination of the surroundings of a motor vehicle.

This object is achieved by the subject matter of the independent claims. Advantageous embodiments result from the dependent claims, the description and the figures.

The invention relates to a single headlight, that is to say a single headlight, for a motor vehicle which has at least one light source for emitting a first and a second light beam. It So at least two light beams are emitted by one or more light sources. The single headlight further comprises at least one first and at least one second controllable deflection element for the respective variable deflection of the first and the second light beam in a respective first and second solid angle range onto a predetermined lighting surface. More than two light beams can also be provided here, for example three light beams each with at least one deflection element, so that the individual headlight then has at least three deflection elements. In particular, the single headlight can have a control unit for controlling the deflection elements. The respective solid angle areas correspond to the respective illuminated areas on the illumination surface, which are illuminated by the respective light beams. A partial area, the respective illumination area, of the illumination surface is scanned or scanned or scanned by the light beams, and thus illuminated or illuminated. The light rays can also be pulsed. The solid angle ranges can be determined by at least two respective extreme positions of the controllable deflection elements. In these and in a large number of intermediate positions of the deflection elements, the respective deflection elements can then direct the respective light beams on the points assigned to the extreme and intermediate positions in the respective illumination area. In the respective extreme positions, the respective light beam can be directed onto the edge of the illuminated area by the controllable deflection element.

In order to improve the illumination, the illumination area has two edge areas and a central area, the edge areas making up a large part of the illumination area. The central area and the two edge areas are disjoint, that is to say each different from one another without an overlap. The two illumination areas both extend into the central area and in addition each include only one, each different from the two edge areas. In the central area, which may include a center of the illumination area, for example, part of the edge of the respective illumination areas is located. This has the advantage that the central area is not only illuminated by one light beam, but by at least two light beams. Since the edges of the illuminated areas have a particularly high brightness, the brightness in the central area is particularly greatly increased in comparison to the two edge areas, in particular by more than a factor of two. As The result is a spatial light distribution generated by the irradiation of the lighting surface with the light beams, which is emitted by the single headlight into an environment of the motor vehicle, in a region of the light distribution corresponding to the central region, preferably the center of the light distribution, which is particularly bright. This corresponds to the requirements an illumination of the surroundings of the motor vehicle caused by the light distribution, since strong illumination by a particularly bright light is desired in a central region and weaker illumination by a less bright light in an edge region. In this way, the required minimum brightness values can also be reached more easily in a central area of the light distribution, so that the light source also has a lower beam power and can be designed to be weaker.

In an advantageous embodiment it is provided that the light beams each have the same wavelength or wavelength distribution. This has the advantage that multiple light beams can be generated with just a single light source. In addition, a uniform color of the light distribution is achieved in the different areas, especially in the different edge areas.

In a particularly advantageous embodiment, it is provided that the illumination surface comprises a surface of a, in particular fluorescent, converter element for converting the light beams into light of a different, larger wavelength. This has the advantage that a particularly pleasant spectrum of a light distribution emitted into the surroundings of the motor vehicle is achieved with the light rays.

In an alternative embodiment it is provided that the illumination surface comprises a transparent surface of the individual headlight, in particular a surface of a pane and / or a surface of an optical lens of the individual headlight. The pane can, for example, be part of a front glazing of the individual headlight. This has the advantage that an environment of the motor vehicle can be illuminated directly by the light rays of the light source without wavelength conversion, and a light distribution is generated in this environment that is particularly bright in the middle. By adjusting the wavelength of the light emitted by the light source, the illumination of the surroundings can also be set particularly precisely.

In a particularly advantageous embodiment it is provided that the two illumination areas overlap in the central area. Thus, an overlap area of the illumination area can be illuminated by the first light beam and the second light beam, a first remaining area of the illumination area, which differs from the overlap area, can be illuminated by the first and not by the second light beam, and a second remaining area of the illumination area, which is different from the overlap area and the first remaining area, can be illuminated by the second and not by the first light beam. The first and / or the second remaining area each correspond to a large part of the first or second solid angle area. The overlap area can preferably correspond to between 5 and 15% of the respective total illumination areas or between 5 and 15% of the solid angle areas or a solid angle area between 2.5 and 5 ° of at least one of the deflection elements. This has the advantage that maximum brightness can be achieved in the central area or in the overlap area by overlapping the illumination areas.

In a further embodiment it is provided that at least one of the two deflection elements is arranged more distant from one of the two edge regions than from the other edge region and the illumination region assigned to this deflection element comprises the edge region distant from this deflection element. With a given geometrical arrangement of the illumination surface and the deflection elements, the average distance between the deflection element and the assigned illumination area can be maximized. In this way, the angular misalignment of the light beam within the illuminated area can be reduced. This has the advantage that the resolution in the central area is improved. This corresponds to the requirements for a light distribution for a motor vehicle.

According to the invention, the deflection elements each comprise at least one micromirror. Micromirrors are usually operated resonantly or quasi-statically for beam deflection. Accordingly, in an edge area in which a direction of movement of a deflected beam has to be reversed, very long dwell times of the beam on the illumination surface become generated. This applies above all to the resonant operating mode. Since, according to Talbot's law, the brightness of an irradiated area point results from the intensity and residence time of the beam at this area point, the brightness is smallest in the middle of the illuminated area and greatest at the edge of the illuminated area. The factor between the edge area and the center for a micromirror is typically between 10 and 90. The use of micromirrors therefore has the advantage that the brightness improvement in the central area is particularly high. An average brightness in the central area can thus be increased by a factor of, for example, at least 10 and up to 90 in the central area compared to an average brightness in the edge areas.

In a further embodiment it is provided that the light source comprises a semiconductor light source, in particular a laser diode and / or a light-emitting diode. This has the advantage that the light rays are generated particularly efficiently and that particularly high luminance levels can be achieved when using a laser diode.

The invention also includes a motor vehicle with a single headlight according to one of the described embodiments.

The invention also relates to a method for operating a single headlight, that is to say a single headlight, for a motor vehicle. This comprises emitting a first and a second light beam through a light source. It also includes a variable deflection of the first and the second light beam into a respective first and second solid angle range on a predetermined illumination surface by a first and a second controllable deflection element. The lighting area has two edge areas and a central area, and the edge areas make up a large part of the lighting area. The deflection element can be controlled, for example, by a control unit. Finally, the method comprises illuminating respective illuminating areas on the illuminating surface that correspond to the respective solid angle areas, both of which extend into the central area and moreover each comprise only one of the two edge areas. Illumination can take place by moving the respective illumination areas with the respective light beam.

All of the features and combinations of features mentioned above in the description and the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures can be used not only in the respectively specified combination but also in other combinations or on their own without the scope of To leave the invention insofar as they come within the scope of the claims. Embodiments of the invention are thus also to be regarded as encompassed and disclosed, which are not explicitly shown and explained in the figures, but can be derived from the explanations explained and can be generated by separate combinations of features.

Fig. 1

eine schematische Darstellung einer beispielhaften Ausführungsform eines Einzelscheinwerfers; und

Fig. 2

eine schematische Darstellung einer beispielhaften Lichtverteilung auf einer Beleuchtungsfläche wie sie durch eine weitere beispielhafte Ausführungsform eines Einzelscheinwerfers erzeugbar ist.

Exemplary embodiments of the invention are explained in more detail below with the aid of schematic drawings. Show it:

Fig. 1

a schematic representation of an exemplary embodiment of a single headlight; and

Fig. 2

a schematic representation of an exemplary light distribution on an illumination surface as it can be generated by a further exemplary embodiment of a single headlight.

Identical or functionally identical elements are provided with the same reference symbols in the different figures.

Fig. 1 shows a schematic representation of an exemplary embodiment of a single headlight. In the example shown, the individual headlight 1 has a first light source 2 and a second light source 3, which in the present case are of identical construction and emit monochromatic light of a predetermined wavelength, for example 450 nm, in the form of a first light beam 4 and a second light beam 5, for example as laser diodes. In the present case, the individual headlight 1 also comprises a first and a second optical system 6, 7, which can each contain a plurality of optical components. In the present case, these are, for example, a filter element 8, 9, a fixed deflection element 10, 11 and respective optical lenses 12, 13. The individual headlight 1 further comprises a first controllable deflection element 14 and a second controllable deflection element 15. Finally, the individual headlight 1 in the example shown, there is also a fluorescent converter element 16 and here a converging lens 17. The illustration here is a sectional illustration perpendicular to an illumination surface 20 of the converter element 16, which is designed as a plane. The illumination surface 20 can alternatively also be curved.

The respective first and second light beams 4, 5 pass through the respective first and second optical systems 6, 7 after being emitted by the first and second light sources 2, 3, in order to then strike the first and second deflection elements 14, 15, respectively. The two light beams 4, 5 are variably deflected at these controllable deflection elements 14, 15. Due to the variable deflection, the two light beams 4, 5 sweep over a respective first and second solid angle range α ₁ , α ₂ . In the figure, the light beam 4, 5 is shown in three exemplary positions or positions of the deflection elements 14, 15, so that the first light beam 4 is shown as splitting into first light beams 4a, 4b, 4c and the second light beam 5 as being in three Splitting light rays 5a, 5b, 5c. The respective middle light rays 4b, 5b correspond to a deflection by the deflection element 14, 15 in a neutral position, the respective edge light rays 4a, 4c, 5a, 5c correspond to a deflection of the respective light rays 4, 5 by the two deflection elements 15, 15 in extreme positions. The deflection elements 14, 15 are each pivoted between these two extreme positions in order to cover the first and the second solid angle range α ₁ , α ₂ with the respective light beam. In the illustration, the two solid angle regions α ₁ , α _{2 are} each shown two-dimensionally in an xz plane, but in this example they also include a region which extends in the y direction perpendicular to the xz plane.

Due to the variable deflection of the two light beams 4, 5, a respective first illumination area 18 and second illumination area 19 of an illumination surface 20 of the converter element 16 are illuminated or scanned by the respective light rays 4, 5. The respective light beam 4, 5 is thus repeatedly guided or moved over the respective illumination area 18, 19, so that in the present case the illumination surface 20 is excited to light up in the removed illumination areas 18, 19. The light beams 4a, 4c, 5a, 5c deflected in the extreme positions of the respective deflection elements 14, 15 each determine an edge of the associated respective illumination area 18, 19 and excite it Emitting a light on. Since the deflection elements 14, 15 are designed here as micromirrors, the deflection elements 14, 15 are moved back and forth between the two extreme positions. Since the deflection elements 14, 15 have a speed of zero in the extreme positions, and the brightness results from a given intensity and a given time of stay at a point according to Talbot's law, the brightness is at the edge of the respective illumination areas 18, 19 many times higher than in a central area of the two illumination areas 18, 19.

In the present example, the two illumination areas 18, 19 adjoin one another in a center of the illumination surface 20, so that this center is particularly bright. However, the two illumination areas 18, 19 could not directly adjoin one another, but rather be separated by a small area of the illumination surface 20 that is not illuminated by the light beams 4, 5. Particularly advantageously, the two illumination areas 18, 19 can also overlap. In all cases, increased brightness is achieved in a central area 21, in which the two illumination areas 18, 19 extend, whereas in a respective first edge area 22 and in a second edge area 23 of the illumination surface 20, only the usual, according to the prior art usual brightness is achieved. Since in the present example the central region 21 corresponds to a central region of a light distribution and thus a center of an illumination of an environment of the motor vehicle, this arrangement is particularly advantageous. In the arrangement shown here by way of example, the respective light sources 2, 3 and deflection elements 14, 15 are arranged symmetrically with respect to the illumination surface 20. Of course, asymmetrical arrangements are also possible.

It is also possible to adjust the respective deflection elements 14, 15 such that an average distance between the respective illumination area 18, 19 and the deflection element 14, 15 is maximized. In this case, at least one of the two deflection elements 14, 15, in the present case both, is arranged further away from one of the two edge regions 22, 23 than from the respective other edge region 23, 22. Thus, in the present case, the first deflection element 14 is further away from the second edge region 23 arranged than from the first edge region 22. Accordingly, the second deflection element 15 is arranged further away from the first edge region 22 than from the second Edge area 23. The respective illumination areas 18, 19 can now be shifted by adjusting the corresponding solid angle area α ₁ , α ₂ such that the respective deflection elements 14, 15 scan or move off the more distant edge areas 23, 22 of the illumination surface 20. In the present case, the illumination area 19 would no longer comprise the second edge area 23 but the first edge area 22 and the first illumination area 18 would no longer include the first edge area 22 but the second edge area 23. Moreover, the edges of the respective edge light beams 4c and 5c would no longer be Illumination areas 18, 19 lie in the central area 21, but rather the edges corresponding to the marginal light beams 4a, 5a. In this way, a smaller angular offset can be achieved, as a result of which the resolution in the central region 21 and partial regions of the edge regions 22, 23 adjoining the central region 21 are improved.

Fig. 2 shows a schematic representation of an exemplary lighting surface of a further exemplary embodiment of a single headlight. The illumination surface 20, which extends in an xy plane, has a first illumination area 18, a second illumination area 19 and a third illumination area 24. The first and second illumination areas 18, 19 overlap in a first central area 21. Both illumination areas 18, 19 are designed here in a rectangular shape and together likewise form a rectangle which extends mainly in the x direction. The third illumination area 24 likewise forms a rectangle, which extends mainly in the x direction and, in the example shown, is longer in this direction than each of the two illumination areas 18, 19. In the present case, the third illumination area is offset in the y direction from the first two illumination areas 18, 19 are arranged and overlap with the first illumination area 18 in a second central area 25 and with the second illumination area 19 in a third central area 26. All three central areas 21, 25, 26 in turn overlap in an area which in this example is one Center M of the illumination surface 20 comprises. A maximum brightness can thus be achieved by overlapping all three illumination areas 18, 19, 24 in the center M and a region of the illumination surface 20 surrounding them. The illumination surface is here symmetrical with respect to an axis of symmetry A, which runs through the center M in the y direction.

In addition, light functions such as a low beam or a high beam can also be realized by adjusting the extent of the overlap or, for example, certain illumination areas 18, 19, 24 no longer being illuminated by a respective light beam. For example, in the example shown it is conceivable that lighting the entire illustrated illumination area 20 corresponds to a high beam and, for example, a low beam function can be achieved by the first illumination area 18 no longer being illuminated or illuminated and thus darkened.

Claims (9)

1. Method Individual headlight (1) for a motor vehicle, comprising

   - at least one light source (2, 3) for emitting a first and a second light beam (4, 5),

   - a first and a second controllable deflection element (14, 15) for variably deflecting the first and second light beams (4, 5) onto a predefined illuminated surface (20) within a first and second solid angle range (α1, α2) respectively, wherein illumination zones (18, 19) that are illuminated by said light beams (4, 5) correspond to the solid angle range (α1, α2) on the illuminated surface (20),

   characterised in that

   - the illuminated surface (20) has two peripheral areas (22, 23, 24) and a central area (21, 25, 26), the two peripheral areas (22, 23, 24) making up a large part of the illuminated surface (20);

   - the deflection elements (14, 15) each comprise a micro-mirror and the brightness is smallest in the middle of the illumination zones (18, 19) and is largest at the edge of the illumination zones (18, 19);

   - the two illumination zones (18, 19) both extend into the central area (21, 25, 26) and each comprise only one of the two peripheral areas (22, 23, 24), so that a part of the edge of the respective illumination zone (18, 19) lies in the central area (21, 25, 26) and the brightness in the central area (21, 25, 26) is higher in comparison to the two peripheral areas (22, 23, 24).
2. Individual headlight (1) according to claim 1,
   characterised in that
   the light beams (4, 5) each have the same wavelength or wavelength distribution.
3. Individual headlight (1) according to one of the preceding claims,
   characterised in that
   the illuminated surface (20) comprises a surface of a converter element (16) for converting the light beams (4, 5) into a light at another wavelength.
4. Individual headlight (1) according to one of claims 1 or 2,
   characterised in that
   the illuminated surface (20) comprises a transparent surface of the individual headlight (1), in particular a surface of a disc and/or a surface of an optical lens of the individual headlight (1).
5. Individual headlight (1) according to one of the preceding claims,
   characterised in that
   the two illumination zones (18, 19) overlap in the central area (21, 25, 26).
6. Individual headlight (1) according to one of the preceding claims,
   characterised in that
   at least one of the two deflection elements (14, 15) is arranged further from one of the two peripheral areas (22, 23, 24) than from the other peripheral area (22, 23, 24), and the illumination zone (18, 19) assigned to this deflection element (14, 15) comprises the peripheral area (22, 23, 24) that is further from the deflection element (14, 15).
7. Individual headlight (1) according to one of the preceding claims,
   characterised in that
   the light source (2, 3) comprises a semiconductor light source (2, 3), in particular a laser diode and/or an LED.
8. Motor vehicle with an individual headlight (1) according to one of the preceding claims.
9. Method for operating an individual headlight (1) for a motor vehicle, comprising the steps:

   - emitting of a first and second light beam (4, 5) by at least one light source (2, 3);

   - variable deflecting of the first and second light beam (4, 5) on to a predefined illuminated surface (20) within a first and second solid angle range (α1, α2) respectively, by a first and second controllable deflection element (14, 15), which each comprise a micro-mirror, wherein the illuminated surface (20) has two peripheral areas (22, 23, 24) and a central area (21, 25, 26), the two peripheral areas (22, 23, 24) making up a large part of the illuminated surface (20);

   - illuminating the illumination zones (18,19) corresponding to the respective solid angle ranges (α1, α2) on the illuminated surface, which both extend into the central area (21, 25, 26) and in addition each comprise only one of the two peripheral areas (22, 23, 24), wherein the brightness is smallest in the middle of the illumination zones (18, 19) and is largest at the edge of the illumination zones (18, 19), so that a part of the edge of the respective illumination zone (18, 19) lies in the central area (21, 25, 26) and the brightness in the central area (21, 25, 26) is higher in comparison to the two peripheral areas (22, 23, 24).

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