EP3014171B1 - Vehicle headlamp - Google Patents

Description

The invention relates to a headlamp for vehicles, with a plurality of light sources and an optical system assigned to the light sources, a first lighting unit with at least one light source for generating a first, dynamically variable luminous image and a second, laser lighting unit with at least one laser light source, at least one Beam deflection unit and at least one light conversion unit are provided, and the optics for merging the two light images, which are set up by the first light unit and on the light conversion unit of the second, laser light unit to produce a total light distribution on a roadway, the at least one beam deflection unit being around At least one axis of pivotable micromirrors is formed, the first lighting unit having a plurality of light sources and individual optics assigned to the light sources.

A headlight of this type is, for example, from the US 2011/0249460 A1 known. In addition to a conventional headlight module for a low beam distribution, this headlight also has a scanning laser system in which two laser beams deflected via moving micromirrors generate a luminous image on a fluorescent matrix, which is projected onto a roadway using a lens in order to generate a dynamically changeable light configuration there .

With one in the US 2008/0013329 A1 In the disclosed headlights, a flat laser element with individual, individually controllable light fields is provided, with the light fields each being assigned a microlens of a preceding microlens array, which projects the light image generated in each case onto a roadway.

In the case of other headlights for generating dynamically variable illuminated images, such as those in the DE 10 2008 013 603 A1 or in the DE 10 2011 054 234 A1 are shown and described, an array of individual, individually controllable light sources, preferably LEDs, is provided, with each light source being associated with individual optics or light guidance in the form of a light guide or a reflector. The luminous image present on the light exit surface of the light guides is projected onto the road by means of optics, generally a lens.

On the other hand, headlights have also become known in which a central light source is provided, the light of which is projected onto a roadway via a plurality of light guides and via special optics in order to produce a dynamically variable light distribution thereon. Digital light processors (DLPs) are sometimes used for light distribution, as in the US 7156542 B2 , or mechanically movable and therefore selectively controllable light guide, such as in the DE 40 06 938 A1 . The document EP 2 525 140 A2 discloses a headlight for vehicles. The document WO 2014/121315 also discloses a headlight for vehicles. The documents US 2011/0249460 and US 2012/0008098 also disclose headlights for vehicles.

State-of-the-art headlights of the type mentioned allow a lighting pattern that can be dynamically adapted to the respective driving conditions, but there is an increased need for further functionalities in adaptive headlight systems, especially with regard to high-beam functions and a higher resolution of the lighting image. Regardless of these requirements, however, the production costs should be within a reasonable range.

Accordingly, it is an object of the invention to provide a headlamp of the type in question which offers a high dynamic resolution at the lowest possible cost, in particular in a long range of the headlamp illumination.

This object is achieved with a headlamp of the type specified at the outset, in which, according to the invention, the light sources of the first lighting unit are LEDs, and the at least one light conversion unit of the laser lighting unit is provided on the first lighting unit in the region of the light exit surface thereof.

Thanks to the invention, there is obtained a headlamp which offers a high resolution, although the number of individual light sources lies in a frame which does not cause any problems in terms of cost or technical implementation, for example in terms of cooling and dimensions.

Since the light sources of the first light unit are LEDs, there is a large selection with regard to the spectral light distribution and the light intensities at favorable pricing. It can also be advantageous if the optics have two separate optics units, each lighting unit being assigned one optics unit.

On the other hand, in view of the small size, it may be advisable for the optics to have a single common optics unit which is assigned to both lighting units.

Another sensible variant provides that the at least one optical unit is designed as a lens.

Particularly with regard to ease of servicing, it is expedient if the at least one laser light source, the at least one beam deflection unit and the at least one light conversion unit of the laser lighting unit are combined in one structural unit. An extremely proven variant is characterized in that the at least one beam deflection unit is designed as a micromirror that can be pivoted about at least one axis. Furthermore, with regard to a good adaptation of the luminous image, it is advantageous if the first lighting unit has individual light sources arranged in at least two rows and a plurality of columns, the individual light sources being controllable for generating a dynamically variable light distribution on a roadway.

It also improves the adaptability if the at least one beam deflection unit is set up to generate a dynamically variable luminous image consisting of selectively illuminable segments on the light conversion unit.

• Fig. 1 schematisch die wesentlichen Bauteile eines nicht erfindungsgemäßen Scheinwerfers,
• Fig. 2 eine erste Ausführungsform eines Scheinwerfers nach der Erfindung,
• Fig. 3 eine weitere Ausführungsform eines Scheinwerfers nach der Erfindung,
• Fig. 4 das Leuchtbild der ersten Leuchteinheit mit einer Mehrzahl von Lichtquellen,
• Fig. 5 das Leuchtbild der zweiten Laser-Leuchteinheit und
• Fig. 6 die aus den Leuchtbildern nach Fig. 4 und 5 zusammengesetzte Gesamtlichtverteilung.

The invention and further advantages are explained in more detail below on the basis of exemplary embodiments which are illustrated in the drawing. In this show

• Fig. 1 schematically the essential components of a headlight not according to the invention,
• Fig. 2 a first embodiment of a headlamp according to the invention,
• Fig. 3 another embodiment of a headlamp according to the invention,
• Fig. 4 the luminous image of the first lighting unit with a plurality of light sources,
• Fig. 5 the light pattern of the second laser light unit and
• Fig. 6 that from the illuminated pictures 4 and 5 composite total light distribution.

It will start on Fig. 1 Reference, which shows a headlight roughly schematically. In this and the following figures, not all parts are shown which are essential for the function of the invention. For the sake of simplicity, other parts which are well known to the person skilled in the art and also necessary for a headlight, such as a housing, adjusting devices, etc., have been omitted.

To the right of Fig. 1 one recognizes a first lighting unit 1, which, which is shown and described in more detail below, has an array of individual light sources, in particular LEDs, which can be controlled individually or in groups. The individual light sources in this figure are also associated with individual optics, not shown, which are designed, for example, in the form of a light guide or a reflector and generate a luminous image on a light exit surface 2, which can be projected onto the road by means of optics, here using a lens 3 .

Furthermore, a second, namely a laser lighting unit 4 is provided, which in Fig. 1 is shown on the left and which has as essential components a laser light source 5, which generates a laser beam 6, a beam deflection unit 7, which is designed here as a micromirror, and a light conversion unit 8. Such scanning laser light units are known, wherein the laser beam 6 generates a predeterminable luminous image by means of a micromirror of the beam deflection unit 7 which swings around one or about two axes and which is also projected onto the roadway by means of further optics, here a lens 9, and is combined with the luminous image generated by the first lighting unit 1 to form an overall luminous image or an overall light distribution on the road.

Although two lenses 3 and 9 are shown here, this should not rule out that other optical constructions can be used. So the two lenses 3 and 9 one further optics, for example a lens, can be arranged downstream or optics can also be used which also use reflectors.

The laser light source 5 can, for example, generate a laser beam 6 with blue light, which is converted into white light on a phosphor of the light conversion unit 8. Although only a single laser lighting unit 4 is shown in this example, it is entirely possible to use at least one further laser unit, which in turn guides the laser beam to the light conversion unit 8 either by scanning the same beam deflection unit or via a further beam deflection unit.

As can also be seen from the prior art, it is possible to apply a laser layer to the phosphor layer of the light conversion unit from behind, with the radiation of the light converted into phosphor being emitted to the front.

In Fig. 2 A first embodiment of the invention is shown, the first lighting unit 1 being shown in more concrete terms in one of the preferred embodiments and the same reference numerals being used for comparable parts. On the front of the first lighting unit 1, one can see individual optics 10, which are designed here as reflectors, at the base - in Fig. 2 not visible - light sources, preferably LEDs, are arranged. In the present case, the lighting unit 1 has light sources arranged in three rows and 2 × 8 and 1 × 28 columns and, accordingly, many individual optics 10 or reflectors. Here, too, a light conversion unit 8 is provided in the area of the light exit surface of the first lighting unit 1, via which a laser beam 6 generated by a laser light source 5, deflected by an oscillating micromirror of a beam deflection unit 7, scans. Here, the laser lighting unit 4 is formed by the laser light source 5, the beam deflection unit 7 and the light conversion unit 8 arranged on the first lighting unit 1.

In contrast to the execution after Fig. 1 here is a lens 11 and 2 common to light units 1 and 4, namely a lens is provided which merges the luminous image present on the exit surfaces of the optics 10 and the luminous image determined by the scanning laser beam 6 on the light conversion unit 8 and can project onto a roadway.

In Fig. 3 is a further embodiment of a headlight according to the invention is shown schematically, the principle of those after Fig. 2 corresponds, the same reference numerals also being used for comparable parts. The first lighting unit 1 here consists of a light source unit 12 with individual light sources 13, which are designed as LEDs and are arranged in three rows of 26 columns. This light source unit 12 or the individual light sources 13 is assigned a primary optic 14 which, according to the number of LEDs or light sources 13, here 78, has individual totally reflecting light guides 15 which run forward and open into a light exit surface 16. A light conversion unit 8, which is scanned by the laser beam 6, is in turn arranged on this light exit surface 16, the monochromatic laser light being converted into a light (white light) that can be used for illumination of the roadway.

In the executions after Fig. 2 and 3rd it can be seen that a number of the light exit openings of the individual light sources are covered by the light conversion unit 8 with a corresponding phosphor surface. Here there is the possibility that the spectral light distribution of the individual light sources 13 or LEDs in Fig. 3 is matched to the phosphor of the light conversion unit 8 in such a way that they illuminate it or also excite it to light up, as a result of which the in the Fig. 2 and 3rd shown area for the lighting is not "lost". However, it is also possible not to illuminate the corresponding area by the individual light sources, in which case the individual light sources can also be omitted in this area.

In the 4 to 6 three light images of a headlight according to the invention are shown, wherein Fig. 4 the luminous image of a first light unit shows alone, the illumination in this example extending from -1 ° to + 5 ° in the vertical direction and from 15 ° left to 15 ° right in the horizontal direction and a division into three rows of 28 columns each is. It should of course be clear that any division can be made here and, for example, the same number of columns does not have to be provided in every row.

Fig. 5 now shows, on an enlarged scale, an example luminous image which is generated by the second, laser light unit 4. Here, the areas in the horizontal direction from 6 ° left to 6 ° right and in the vertical direction from -1 ° to + 2 ° are preferred, since these Areas provide the majority of the impressions necessary for the driver to drive in the dark.

These two luminous images are overlaid by the optics assigned to the respective light sources or by common optics 11 and combined to form an overall luminous image which is projected onto the road. A corresponding illuminated image is in Fig. 6 shown, from which one can determine the composition of the illuminated pictures 4 and 5 recognizes through the additional lighting of the in Fig. 5 the area shown, the functionality of the headlamp is significantly increased, since a high-resolution laser lighting unit can be used for this area, which enables, for example, a vertical resolution of 0.5 ° in the entire lighting area and of 0.1 ° in the horizontal area.

The values given below may further highlight the advantages of the invention. The maximum illumination of the individual pixels caused by LEDs is currently around 80 to 100 lx, but this is relatively little for high beam. If you take the combination with the laser light unit, which also achieves a maximum of, for example, 80 to 100 lx, you get a high beam that offers lighting in the high beam maximum of 180 to 200 lx, which meets the current requirements for good headlights.

Color effects can also be blurred and a more homogeneous, uniformly colored light image can be created by overlaying different illuminated images.

The combination of the two lighting units also enables a high dynamic resolution to be achieved. The relatively "coarse" pixels of the first lighting unit 1 cover a relatively large area, which is further subdivided by the high-resolution laser lighting unit 4. This means that very small areas can be controlled directly, so that the resolution of the overall system, as already mentioned, can be less than 0.1 ° horizontally and less than 0.5 ° vertically.

The numbers mentioned are only examples and even better values can be achieved in this regard by using even higher resolution two-dimensional laser scanners.

Of course, the areas in which the luminous images are combined can be designed as desired in accordance with the respective requirements, although in no way is a restriction to a high beam intended.

The combination of the two lighting units means that the illumination by the laser lighting unit 4 can also be dispensed with at lower speeds, which is advantageous for safety reasons, since for example when the vehicle is stationary, a light which may be dangerous or unpleasant for the person and emanates from the laser lighting unit is not delivered.

Finally, it should be emphasized that the combination of the two lighting units results in a favorable price-performance ratio compared to headlights based solely on laser scanners.

Claims (7)

1. Headlamp for vehicles, having a plurality of light sources (5, 13) and an optic (3, 9; 11) associated with the light sources
   wherein a first lighting unit (1) with at least one light source (13) for generating a first, dynamically variable illuminated image and a second, laser lighting unit (4) with at least one laser light source (5), at least one beam deflection unit (7) and at least one light conversion unit (8) are provided, and the optics (3, 9; 11) are provided for combining the two light images, which is set up by the first light unit and on the light conversion unit of the second, laser light unit (4) to form a total light distribution on a roadway, the at least one beam deflection unit (7) being designed as a micro-mirror which can be pivoted about at least one axis, the first light unit (1) having a plurality of light sources (13) and individual optics (10, 15) each assigned to the light sources,
   characterised in that
   the light sources (13) of the first lighting unit (1) are LEDs, and the at least one light conversion unit (8) of the laser lighting unit (4) is provided on the first lighting unit (1) in the region of its light exit surface (16) from the individual optics (10, 15).
2. Headlamp according to claim 1, characterised in that the optical system comprises two separate optical units (3, 9), wherein each lighting unit (1, 4) is associated with a respective optical unit.
3. Headlamp according to claim 1, characterised in that the optical system comprises a single common optical unit (11) which is associated with both light units (1, 4).
4. Headlamp according to one of claims 1 to 3, characterised in that at least one optical unit (3, 9; 11) is formed as a lens.
5. Headlamp according to one of claims 1 to 4, characterised in that the at least one laser light source (5), the at least one beam deflection unit (7) and the at least one light conversion unit (8) of the laser light unit (4) are combined in one structural unit.
6. Headlamp according to one of claims 1 to 5, characterised in that the first lighting unit (1) has individual light sources (13) arranged in at least two rows and a plurality of columns, wherein the individual light sources can be controlled to generate a dynamically variable light distribution on a roadway.
7. Headlamp according to one of claims 1 to 8, characterised in that the at least one beam deflection unit (7) is set up to generate a dynamically variable light image consisting of segments that can be selectively illuminated on the light conversion unit (8).

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