AT517733A1 - Laser unit with aperture for reduction of aberrant light and laser module - Google Patents

Abstract

In a laser unit (10) for a vehicle headlight, laser light (14) is generated by a laser light source (11) and collimated with collimator optics (13) and directed to a deflection mirror (15) associated with the laser unit (10). In this case, the laser light spreads predominantly along a regular light path (14); deviating therefrom, there are further light components, aberrant light (23a, 23b) whose optical path has at least one additional reflection (24) on or in an optical component. The collimator optics (13) contains, in addition to at least one optical component (12), a diaphragm (25), which is preferably arranged outside an envelope (22) of the regular light path (14) and which blocks at least part of the aberrant laser light (23a, 23b) before it can fall on the deflection mirror (15).

Description

Laser unit with aperture to reduce aberrant light

The invention relates to a laser unit for a vehicle headlight with a laser light source, preferably laser diode, for emitting laser light and with a collimator, which comprises at least one optical component, wherein the collimator is adapted to collimate laser light emitted from the light source and on one of the laser unit directed deflecting mirror, wherein the laser light propagates predominantly along a regular light path. The invention also relates to a laser module having a plurality of laser units and to a vehicle headlight having a laser unit or a laser module of the type mentioned.

As used in this disclosure, optical device means an optical component having light-gathering or scattering properties, and more specifically a shape reflector (eg, a hollow or convex mirror) or a refractive component, such as an optical lens or a refractive homogenization element, including combinations of these components could be. Furthermore, the regular light path is understood to be the light path through which a light beam emitted by the laser light source in the maximum of the radiation passes through the optical system, ignoring unwanted reflections or scattering effects. As a regular laser beam, laser light propagating along the regular light path is understood to mean a deviation (transverse distance from the path of the maximum or angular deviation) at which the intensity drops to a predetermined fraction, typically half, of the intensity at the maximum is. In addition, unwanted reflections on optical components are ignored for the regular light path. The regular laser beam usually has a defined, dependent on the type of light source cross-section. The regular light path is usually selected so that it runs along the optical axis of the collimator optics, since this is easier to treat in terms of lighting technology than away from the optical axis (so-called "oblique") beam bundles The diameter of the laser beam is typically a few millimeters, eg 2 mm, and the beam divergence is on the order of a few mrads, often much lower, for example at 0.3 to 0, the laser diode is typically circular or elliptical. 5 mrad.

The use of laser light sources in motor vehicles, in particular for headlights of motor vehicles, is currently gaining in importance, since laser diodes enable more flexible and efficient solutions, whereby the luminance of the light bundle and the light output can be increased considerably and high-resolution scanning AFS headlight systems can be realized.

In known lighting devices in vehicles, however, the laser beam is not emitted directly from the lighting device or the headlight in order to avoid endangering the eyes of humans and other living beings by the extremely concentrated light beam of high power. Rather, the laser beam is directed to an intermediate conversion element containing a material for luminance conversion, called "phosphor" for short, which converts the laser light, for example a wavelength in the blue region, into visible light, preferably white light, which becomes visible light In the context of the present invention, "phosphor" is generally understood to mean a substance or a substance mixture which converts light of one wavelength into light of another wavelength or of a wavelength mixture - so-called "wavelength conversion", in particular "white" light to create. In most cases, the conversion element is preceded by a programmed pivotable mirror (with respect to the beam path of the laser light), which serves as a deflection mirror to direct the laser beam to different locations on the planar conversion element. In order to achieve that on the conversion element well-defined light spots or (with a moving mirror) light pattern are generated, the light originating from the laser light source is collimated by means of an optical arrangement, which is referred to here as collimator optics. The collimating optics is located (with respect to the beam path) between the light source and the mirror, usually immediately after the laser light source, and may comprise a plurality of optical components and / or light-limiting components, but is often formed by a single optical lens. Due to the programmed movement of the mirror, the laser beam generates a luminous image on the conversion element, and this luminous image is projected onto the roadway of a road by an optical arrangement, for example an imaging optics with reflectors and / or preferably lenses.

In this illumination device, therefore, a focused laser beam, or a plurality of such focused laser beams, is directed onto a deflection device, which can be used, for example, as a MEMS device.

Scanning mirror is formed with a highly reflective mirror surface, guided and deflected by the deflection so that the laser beam falls on other optical components and there a luminescent phosphor (so-called "phosphor") spatially excited.

Applicants have observed that it is of particular importance that the laser beam only illuminate the highly reflective mirror surface of the deflection device. The mirror surface has a very high reflectivity, which is typically over 99%. The part of the light which is not reflected is deposited in the mirror surface in the form of heat, which leads to heating of the component to which the mirror surface belongs. By appropriate measures - namely passive or active cooling by dissipating the heat towards the headlight housing, usually by heat conduction and / or ventilation - this heating of the component is compensated to avoid that the component or the deflection deformed by excessive heating or gets destroyed. The surfaces of the device outside the mirror surface have significantly lower reflectivities than the highly reflective mirror surface itself, typically 50 to 60%. There is therefore a risk that laser light conducted past the mirror surface will strongly heat the component or the deflection device and lead to undesired deformation or thermal destruction.

In addition, from the normal beam path in a laser system of the type considered here, different light - hereinafter referred to as aberrant light - basically disadvantageous, since the phosphor is excited by such aberrant light in areas to which the regular laser beam just not. Thus, in the light distribution even regions that are supposed to remain unlit, not completely darkened, resulting in a falsification of the desired light image and the resulting light distribution on the street.

But the appearance of aberrant light can not be completely prevented for at least two reasons. On the one hand, deviations of the laser light source, e.g. Defects in the laser light source or incorrect adjustment, cause some of the laser radiation to deviate from the regular direction of the laser beam. On the other hand, the collimator optical system contains optical components, in particular optical lenses, on the surfaces of which reflections occur that are undesirable in themselves but unavoidable for physical reasons (Fresnel reflection). Although these parasitic reflections can be largely suppressed by suitable coatings of the refractive surfaces, remaining effects of about 1% per interface remain. At a currently used laser power of e.g. up to 35 W, this results in the considerable value of 350 mW, which is lost as aberrant light.

It is known to use for limiting the laser beam to the outside pinhole; However, these diaphragms limit the regular laser beam itself and therefore lead to loss of light output.

It is therefore an object of the invention to reduce or eliminate as far as possible the effects of laser light which deviates from the regular beam path, in particular aberrant light which is produced by unwanted reflections on refractive surfaces. However, the regular light beams of the laser light should not be obstructed.

This object is achieved by a lighting module of the type specified in that the collimator according to the invention is associated with a diaphragm, which propagates at least a portion of aberrant laser light, which propagates along an optical path, which differs from the regular light path and at least one additional reflection on or in includes an optical component of the collimator, fades out before it falls on the deflection mirror - ie before it can reach the deflection mirror. In this case, the diaphragm can be arranged at any suitable location in the light path of the aberrant light, in particular after or even before the location where the additional reflection (in the absence of diaphragm and thus unblocked light path) takes place.

According to the invention, therefore, an additional aperture is provided which serves to impinge on the mirror component only that light which impinges on the mirror surface; On the other hand, the diaphragm absorbs aberrant light which does not correspond to the focused laser beam. On the one hand, this prevents the MEMS component from being excessively heated or even destroyed by light, which is caused by the above-mentioned parasitic reflections, and, on the other hand, reduces the total light deviating from the regular beam path in the optical system, which is achievable by the phosphor Contrast benefits.

The diaphragm according to the invention can also be designed so that the aperture is arranged with its optically effective opening limit outside of an envelope of the regular light path, whereby no light of the regular laser beam is shaded to the phosphor out. In this regard, a limitation of the efficiency with respect to the laser radiation generated by the laser light source is avoided. In other words, the aperture can be dimensioned so that the regular beam path of a properly adjusted laser beam can pass through the aperture invention unhindered. Of course, moreover, care must be taken to ensure that the diaphragm according to the invention and its suspension nowhere obstruct the beam path of the laser beam, neither before nor after the deflection at the deflection mirror.

The solution according to the invention provides additional advantages in addition to the thermal relief of the mirror component achieved in this way. Aberrant light, which is reflected off the mirror surface or even with an irregular beam direction over the mirror surface, hits the phosphor uncontrollably, and this will be excited and emit white light. This would lead to unwanted light images and stray light on the road, to exceeding the permissible limits for glare and stray light in headlights.

In addition, the solution according to the invention provides protection against erroneous misadjustments of the laser diode and / or the optical components, as components are hit outside of the highly reflective surface of the deflecting mirror by a misaligned laser beam and thus could be heated inadmissible. If the laser beam is displaced, for example due to erroneous adjustment or due to impact during operation, the mirror is not destroyed due to the deviating laser radiation but, thanks to the invention, merely heats the diaphragm according to the invention. This can be detected for example by a temperature monitoring, which detects excessive heating as a fault and shuts off the laser for safety reasons.

In an advantageous embodiment of the invention, a diaphragm between the collimator and the deflection mirror can be arranged. Here, a positioning immediately before the deflection mirror is considered favorable. This allows the masking of aberrant light due to unwanted reflections on optical components of the collimator optics.

In another advantageous embodiment of the invention, a diaphragm may be arranged in front of the first optical component of the collimator optics. It can thereby be achieved that laser light components which emanate from the laser light source at a large angle and would propagate in the collimator optics under undesired reflections are masked out.

These two embodiments can also be combined, i. It can ever be provided before and after the collimator an aperture.

For example, the aperture may have a preferably circular or oval (in particular ellipsoidal shaped) opening, the inner diameter of which allows the passage of, preferably the unimpeded passage of, the laser light according to the regular light path. Alternatively, the opening may have a different shape, e.g. square or rectangular, which surrounds the cross section of the regular ray.

It may also help simplify the design of the components of the laser unit when the bezel is integrated with a lens mount for holding one of the optical components of the collimator optics.

As a safety measure, it may also be provided that the diaphragm has a temperature sensor for monitoring an impermissible heating as a sign of a faulty adjustment of the optical components.

The laser unit according to the invention is also suitable for a laser module comprising a plurality of laser units according to the invention, the laser units directing their laser light onto a common mirror; In this case, the laser units may have their own collimator optics, which also usually focus the laser light of the laser units on the mirror surface of a common converter element. The laser units may also have a common collimator optics, so that a laser module for a vehicle headlight with a plurality of laser units, each with a laser light source - preferably laser diode - is formed for emitting laser light, with a collimator optics as described above, wherein the laser light of the laser units merged and on a common mirror is passed. The invention is particularly advantageous in a vehicle headlamp with a laser unit and / or a laser module of the type mentioned.

The invention, together with further embodiments and advantages, will be described below with reference to some embodiments, which are illustrated in the accompanying drawings and are not to be construed as limiting the invention. The drawings show in schematic form

1 shows an overview of the beam path in a headlight with a laser unit;

FIG. 2 shows the beam path between the laser light source and the mirror, the regular beam path and exemplary aberrant light components being shown; FIG.

Fig. 3 is an enlarged view of a controllable mirror;

4 shows an embodiment of the invention in which a diaphragm according to the invention is arranged between collimator optics and mirror;

5 shows the geometry of the diaphragm of FIG. 4;

FIG. 6 shows another type of aberrant light with a thick lens of the collimator optics; FIG.

FIG. 7 shows an embodiment of the invention with a diaphragm according to the invention connected upstream of the lens of FIG. 6; FIG. and

8 shows a further embodiment of the invention with a laser module having a plurality of laser light sources and a diaphragm according to the invention in a common collimator optics.

In Fig. 1, a typical beam path is sketched in a scanning laser headlight 9, which is basically known type, but is also used in the invention. The laser head 9 (which is shown here only schematically and without housing) has one or more laser units 10 (only one laser unit is shown), which generates a laser beam. For this purpose, each laser unit as a light source to a laser diode 11 which emits laser light, and a collimator optical system 13, which forms the laser light into a laser beam 14 and directed to a laser unit associated with the deflection mirror 15. The collimator optics 13 comprises one or more optical components 12 arranged one behind the other, for example a single optical lens or two lenses arranged directly behind one another.

The deflection mirror 15 comprises a programmed adjustable mirror surface 16, typically in the form of a plane mirror plate, which is pivotable by (not shown) adjusting components about two axes 18x, 18y transversely to the propagation direction of the laser beam. A control unit 50 assigned to the laser unit supplies power to the light source 11 and controls the setting components of the pivot axes 18x, 18y. By means of the deflection mirror 15, the laser beam is converted to a phosphor 55, which converts the incident laser light into visible light, where a light image 54 is generated there as a result of the scanning movement of the deflection mirror; This light image is projected by an imaging optics 56, here for example an optical lens, as a light distribution 60 on the roadway of a road. The collimator optics thus additionally serves to focus the laser light emitted by the light source onto the converter element 55, which follows the deflection mirror 15 in the regular light path. Focusing serves to concentrate the laser beam onto a light spot (spot) of defined size.

In addition, the brightness in the luminous image can be varied in a spatially variable manner as a function of the point of impingement of the laser beam on the converter element, for example by modulation of the residence time and / or the laser power; the latter can e.g. be set by adjusting the current supplying the light source in accordance with the mirror position. Of course, the arrangement shown in Figure 1 is only exemplary and other beam paths - for example, with the phosphor 55 transmissive beam path and / or with multiple laser beams, which are directed to a common mirror - can also be used.

FIG. 2 shows a schematic representation of the light profile in the laser unit 8 according to the prior art, in a longitudinal sectional view along the optical axis, which is symbolized by a dot-dash line; FIG. the optical components are shown in section and have a rotationally symmetrical about the optical axis shape, the mirror is, however, shown in a front view. In the example shown here, the collimator optics 13 is realized by two lenses 12 arranged one behind the other. The laser beam 14 is collimated so that it is focused on the conversion element 55 via the deflection mirror 15; it generates on the mirror surface 16 a light spot 20. The laser beam 14 is designed with respect to a regular beam path, which is zero by a minimum number of reflections - in this case zero, so no reflections, but only refraction, since the collimator has no reflective elements - at the optical interfaces of the optical

Components 12 during passage of the laser light 14 through the collimator 13 distinguishes. This regular beam path can also be described by an envelope 22, which surrounds the regular light components. The optical interfaces of the lenses are tempered, for example by AR coatings of known type, to reduce light losses due to reflection 24. However, in general, the reflections 24 can not be completely suppressed. A combination of reflections results in additional - here referred to as aberrant - light components which, like the regular laser beam, propagate forward but do not have its collimated properties; of which, by way of example, two beam paths 23a, 23b are shown. These aberrant light components can thus illuminate undesired regions of the deflection mirror and / or surrounding components; This is symbolized in FIG. 2 by a scattered light region 21 which surrounds the light spot 20.

FIG. 3 shows an exemplary structure of the deflection mirror 15, for example in MEMS technology. The deflection mirror 15 is designed biaxially pivotable, wherein the mirror surface 16 is arranged on a plate-like member which is hung pivotally about a first axis 18y in an intermediate frame 17, which in turn is suspended about a second axis 18x pivotally mounted in a main frame 19. The suspensions are designed, for example, in a known manner as controllable torsion elements, which thus serve as adjusting components for the pivot axes 18x, 18y.

Fig. 4 shows a first embodiment of the invention in a representation analogous to FIG. 2, wherein the Fig. 2 corresponding components are given the same reference numerals. In order to separate out aberrant light components, in particular the light beams 23a, 23b, the collimator optics 13 has an aperture 25, which is arranged here between the last optical component of the collimator optics 12 and the deflection mirror 15. Typically, positioning of the aperture 25 is immediately in front of the mirror 15, i. this as close as possible, advantageous, since this a particularly simple limitation to the working range of the mirror surface 16 can be achieved. The aperture 25 is generally a pinhole with a e.g. circular aperture centered about the optical axis; also a shaping according to an ellipse is often used. As a variant, the opening may have a different shape, e.g. square or rectangular, if this corresponds better to the cross section of the regular beam corresponding to the envelope 22.

In accordance with its intended purpose, the aperture 25 must be shaped and materialized to have high absorption and low reflectance, to avoid generating additional aberrant light by uncontrolled reflected light. Furthermore, the aperture 25 must be able to permanently absorb the light output without being destroyed by light radiation and the resulting thermal load. In addition, no mechanical changes - e.g. due to thermal expansion - which would cause regular portions of the laser beam to be shaded. This can be achieved, for example, by using the aperture as a perforated plate anchored in the housing surrounding the light unit or the spotlight housing made of a suitable thermally conductive material having an absorbent surface - e.g. a metal foil with galvanic black-galvanized surface and / or a coating of heat-resistant lacquer - is formed so that the absorbed light output can be dissipated as heat to the housing.

The inner diameter of the aperture of the aperture 25 is determined by the angle of the aberrated light to be suppressed with respect to the optical axis and the beam direction of the regular beam, respectively. This is explained in FIG. 5 with an example. Denoted by the reference numeral 23c is an aberrant light beam emanating from the regular laser light by internal reflection at the mirror-facing surface of the last lens 12 of the collimator optics, reflected a second time on the other surface side of the lens, and thus retracing at the front (towards the mirror). This aberrant light beam 23c has a beam path that deviates from the direction of the optical axis by an angle δ (Greek letter delta). After covering the distance d between the lens 12 and the diaphragm 25, the aberrant light beam 23c is thus at a radial offset

away from the regular laser beam 14, where γ (Greek letter gamma) is the (half) convergence angle of the regular light beam and b is a lateral offset due to the reflection beam path. It suffices, therefore, to design the (e.g., circular) opening of the shutter to have an inner diameter D larger than the diameter L of the regular laser beam at the position of the shutter 25, but not larger than

to hide the aberrant light portions 23c. If the laser beam has a non-circular cross-section, e.g. in the form of an ellipse, this relationship applies to the main directions of the cross section.

It can also be seen from FIG. 5 that it is advantageous to position the diaphragm 25 as close as possible in front of the mirror 15, since this makes it possible to shade most of the aberrant light without impairing the regular laser beam. In addition, here is the value of the offset c greatest, resulting in a high tolerance with respect to the geometric design of the aperture.

Referring again to FIG. 4, the bezel 25 may also be provided with a temperature sensor 26 which monitors the temperature of the bezel. Excessive heating of the aperture 25 indicates an erroneous adjustment of the optical components and / or the light source. Excessive heating may be detected, for example, by the measured temperature rising above a certain preset threshold. Then, the sensor 26 triggers an error condition; Alternatively or in combination, the sensor 26 may trigger a temporary or permanent shutdown of the laser unit. The temperature sensor 26 is favorably arranged on the diaphragm 25 as close as possible to the inner edge, but on the side of the diaphragm 25 facing away from the laser light, in order to avoid measurement distortion due to the light irradiation.

In addition, a laser monitoring sensor 27 (FIG. 1), for example in the form of a photodiode, can be provided, which determines the laser power. The sensor 27 is positioned in the beam path, for example, in front of the first optical component of the collimator optics. The signal from the sensor 27 can be used for a safety shutdown of the laser unit in the event of a laser malfunction. In addition, sensor 27 provides a control to controller 50, for example, to monitor laser intensity for operational variations (e.g., due to heating) and / or due to scanner motion.

FIGS. 6 and 7 show a further embodiment of a laser unit 100, in which aberrant light, which results from the reflection at the outer edge of a lens, is prevented by a diaphragm, which is preferably arranged in front of the relevant lens. It basically applies a beam path as discussed above with reference to FIG. 1; notwithstanding, numerals with an imaginary number 1 are used in Figs. The first lens 112 immediately following the laser light source 111 is shown here as a thick lens with the two principal planes Φ1 and Φ2, which are at a distance t from each other. For example, the laser light source 111 is positioned at a distance from the lens corresponding to the object focal length f of the lens such that the laser beam 22 is parallel collimated (i.e., telecentric) past the lens; by a second lens (not shown in FIGS. 6 and 7), the laser can then be focused on the deflection mirror. The lens height h (diameter of the lens transverse to the optical axis) is also shown.

Light rays which strike the lens 112 at the object side at not too large angles (in particular angles smaller than a) are refracted at the object-side boundary surface 104, move away in the lens material, and are refracted again at the front lens surface 105. The light beam 120 represents a light beam just at the edge of the regular beam path. In contrast, at a large angle from the laser light source 111 outgoing light rays 121 are problematic because they hit the outer lens edge 108, since the lens is limited by the lens height (more precisely: lens diameter) h. If these light components do not escape and / or are absorbed, reflection 107 of the beam occurs at the interface (inwards), and the beam emerges from the lens at a significantly greater angle than aberrant beam 124. The diaphragm 125 stops it aberrant light 124 in that it covers the angular range outside the angle α, which Lichanteile, which differ by additional reflections from the regular beam path, and thus aberrant laser beams represents. On the other hand, light from the laser light source 11 emitting within half the opening angle α should pass through the shutter so as not to decrease the efficiency of the laser light source 111 (e.g., laser diode).

The limit for the angle α (Greek letter alpha), for which the beam is just refracted at the second interface 105 without hitting the outer lens edge 108, can be described by the following equation:

The aperture 125 is expediently designed in terms of position and inner diameter of the aperture so that rays with an angle α, which meets this condition, can pass unhindered. On the other hand, rays incident at a larger angle α than the above condition will allow to be shaded by the aperture.

The shutter 125 may also be equipped with a temperature sensor 126 for monitoring the shutter for excessive heating and / or with a laser monitoring sensor 127 which is preferably positioned within the aperture of the shutter. Otherwise, the same applies to these sensors 126, 127 as discussed above for the sensors 26, 27 of the first embodiment.

The invention can also be used in arrangements with multiple laser light sources. 8 shows a schematic overview of a beam path in a headlight 209 according to another embodiment of the invention, wherein a laser module 200 comprises a plurality (ie, two or more) laser units 210, 220, 230, each including a laser light source 211, 221, 231 , The laser beams 214, 224, 234 emitted by the light sources 211, 221, 231 are combined by means of a beam combining device 201, for example by means of deflection prisms 202, 222, 232, so that a laser beam or homogenized laser beam 204 is formed; suitable means for merging laser beams are well known to those skilled in the art and do not form the subject of the invention. This so-merged laser beam 204 is - as in the previous embodiments - collimated by means of a common collimator 213 with optical components (lenses) 212 and the thus collimated beam 14 directed to a deflection mirror 15, as explained in the preceding embodiments, a scanning movement to Creation of a light image performs. The collimator optics 213 is equipped with a diaphragm 225, with which aberrant light components are rejected. As explained in the preceding embodiments, the aperture 225 may be positioned at any suitable location, for example, as shown here after the last lens 212 of the collimator optics 213 and the deflection mirror 15. Incidentally, for the aperture 225, what has been said in the preceding embodiments applies to FIG analogous way.

Of course, the embodiments discussed above are intended to be illustrative and not limiting of the invention. The person skilled in the art will readily be able to realize further implementations of the invention which are within the scope of the invention as claimed in the following claims.

Claims (10)

claims Laser unit (10, 100) for a vehicle headlight with a laser light source (11, 111), preferably laser diode, for emitting laser light and with a collimator optics (13,113,213), which comprises at least one optical component (12,112, 212), wherein the collimator optics is configured to collimate laser light emitted by the light source and to direct it to a deflection mirror (15) assigned to the laser unit (10, 100), the laser light (14, 120) predominantly along a regular light path, preferably along an optical axis of the collimator optics, propagated, characterized in that the collimator optics (13, 113, 213) is associated with a diaphragm (25, 125, 225), which at least a portion of aberrant laser light, which along a differs from the regular light path light path with at least one additional reflection ( 24, 107) propagates on or in an optical component of the collimator optics, fades out before it is switched to d en deflecting mirror (15) falls. 2. Laser unit (100) according to claim 1, characterized in that the diaphragm (125) is arranged in front of the first optical component (125) of the collimator optics. 3. laser unit (10) according to claim 1, characterized in that the diaphragm (25, 225) between the collimator optics (13) and the deflection mirror (15) is arranged, preferably immediately in front of the deflection mirror. 4. Laser unit according to one of the preceding claims, characterized in that the diaphragm is arranged outside of an envelope (22) of the regular light path. 5. Laser unit according to one of the preceding claims, characterized in that the diaphragm (25, 125, 225) has a preferably circular or oval opening whose inner diameter allows the passage of the laser light according to the regular light path. 6. Laser unit according to one of the preceding claims, characterized in that the diaphragm is integrated with a lens holder for holding one of the optical components of the collimator optics (13,113, 213). 7. Laser unit according to one of the preceding claims, characterized in that the diaphragm has a temperature sensor for monitoring an inadmissible heating. 8. Laser unit according to one of the preceding claims, characterized in that the collimator optics (13, 113, 213) is also adapted to focus the light emitted by the light source laser light on a converter element (55) in the regular light path to the deflection mirror (15 ) follows. 9. Laser module (200) for a vehicle headlight comprising a plurality of laser units (210, 220, 230) each having a laser light source (211, 221, 231), preferably laser diode, for emitting laser light and with a collimator optics (213) as in one of the preceding claims, wherein the laser light (214, 224, 234) of the laser units is brought together and directed to a common mirror (15). 10. Vehicle headlight (9, 209) with a laser unit (10, 100) and / or a laser module (200) according to one of the preceding claims.