EP3168527A1 - Light module for a vehicle headlamp and motor vehicle headlamp with such a light module - Google Patents

Abstract

The invention relates to a light module (10) for a vehicle headlight, comprising at least one LED light source (12) for emitting an LED light beam (18), at least one laser light source (14) for emitting a laser light beam (30) and a conversion device (16), which is arranged such that the LED light beam (18) in an LED light distribution (28) and the laser light beam (30) in a laser light distribution (36) on the conversion device (16) meet, and which is designed such that incident light beam (18, 30) a secondary light beam (40) is emitted. It is proposed that the conversion device (16) be spatially separated and arranged separately from the at least one LED light source (12), and that the light module (10) at least one deflection device (48) with a plurality of independently controllable and movable deflection elements (50) for selectively reflecting at least a portion of the secondary light beam (40) and for generating a Abstrahllichtverteilung (7) of the light module (10).

Description

The present invention relates to a light module for a vehicle headlight. The light module comprises at least one LED light source for emitting an LED light beam and at least one laser light source for emitting a laser light beam. Furthermore, the light module comprises a conversion device which is arranged with respect to the light sources such that the LED light beam with an LED light distribution and the laser light beam with a laser light distribution strike the conversion device, and which is designed such that the light bundles striking the conversion device cause the emission of a secondary light beam from the conversion device.

The invention also relates to a motor vehicle headlight having a housing with a through a transparent cover has closed light exit opening. In the housing at least one light module for generating a Abstrahllichtverteilung is arranged, which passes through the cover on a roadway in front of a motor vehicle equipped with the headlight.

In the field of automotive lighting, especially in motor vehicle headlamps, the use of high-performance light sources with the highest possible luminance is desired. As a result, high-intensity lighting devices can be realized with a small space. The radiated light distributions must have certain, usually prescribed by law properties. These properties relate both to a form of light distribution (extension in the horizontal and / or vertical direction) and a light intensity distribution (brightness distribution) within the light distribution. For the headlights of a motor vehicle (e.g., low beam, high beam, position light, daytime running light, fog light, etc.), white light is usually desired.

With laser light sources, such as semiconductor laser diodes, high radiation performance can be achieved. However, laser light sources emit mostly almost monochromatic, coherent and highly collimated laser light, which can not be used directly in this form as radiated light of the illumination device. Laser light sources are therefore used in automotive lighting with a conversion device or a wavelength converter. At least part of the light generated and emitted by the light sources is converted directly into light of another color when it hits the wavelength converter.

In order to compensate for the low luminous flux provided by the laser diodes, it is known from the prior art to use hybrid systems which, in addition to a laser light source, also have at least one conventional light source, for example in the form of an LED or an LED array. The resulting emission light distribution of a hybrid system comprises a basic light distribution that is generated by the LED light source. The laser light source generates a spot-like laser light distribution, which can have a higher illuminance than the basic light distribution and serves to illuminate one or more concentrated areas of the emission light distribution in order there to locally increase the light intensity. The spotlight distribution is often no brighter than the base light. In the superimposition of spot and background light, however, results in the higher illuminance in the spot-like range of light distribution. Such a hybrid system is, for example, from the EP 2 487 407 A2 known. In this case, the conversion device is arranged directly on the LED chip and completely covers the light-emitting surface of the LED light source.

The laser light source and the LED light source can illuminate a common wavelength converter. When the emitted light hits the wavelength converter, eg, a fluorescent phosphor body, electrons in the wavelength converter are raised to a higher energy level with photon absorption. However, the electrons can not maintain this level and therefore fall back to their original ground state almost immediately. In doing so, they release the absorbed energy and the emission of fluorescence light occurs. This means that photons (ie light rays) of a certain wavelength (of a certain color) are emitted. That's the way it is it is possible for at least part of the light generated and emitted by the light sources to be converted into light of another color as soon as it hits the wavelength converter. Thus, for example, blue LED or laser light is at least partially converted into yellow light by a conversion device with phosphorus. Overlaying the unconverted blue light and the converted yellow light gives the desired white light.

However, the described hybrid system has the disadvantage that the heat development of the LED chip acts directly on the conversion device. This leads to a decrease in the conversion efficiency and adversely affects the life and color stability of the LED (including the LED chip and the converter). Furthermore, the light of the laser light source and the light of the LED are mixed only after the impact with the fluorescent element, that is, after the wavelength conversion. If the light sources are not exactly matched in color, this leads to an inhomogeneous color impression of the emitted light of the light module. In addition, such a lighting device, in which the laser light and the LED light are projected by means of a lens on the road, are perceived by other road users as disturbing and in particular dazzle the oncoming traffic.

Based on the described prior art, the present invention seeks to design a light module with at least one LED light source, at least one laser light source and a conversion device to the effect and further that the above-mentioned disadvantages and limitations of the known light module are overcome.

To solve this problem is proposed starting from the light module of the type mentioned that the conversion device is formed separately from the at least one LED light source and spatially separated from this, and that the light module in a beam path of the secondary light beam at least one deflection with a plurality includes independently controllable and movable deflecting elements for selectively reflecting at least a portion of the secondary light beam and for generating a Abstrahllichtverteilung the light module.

Unlike the known lighting devices, the conversion device is therefore not arranged directly on a light exit surface of the LED chip, but outside of the LED housing and that spatially separated and separately from the at least one LED light source. The LED chip and the conversion device thus form two separate units and can be used separately from one another in the light module and be arranged completely independently of one another in the light module. It is also advantageous that a thermal separation of the two heat sources is realized by the spatial separation of the LED light source and the conversion device, so that a local overheating of the light module or the lighting device, in which the light module is installed, can be prevented. An impairment of the conversion properties of the conversion device can be prevented.

The light module also comprises at least one deflection device with a plurality of independently controllable and movable deflecting elements for selectively reflecting at least part of the radiation emitted by the conversion device Secondary light beam. The reflected part of the secondary light beam generates an emission light distribution of the light module, preferably on a roadway in front of a vehicle equipped with the illumination device according to the invention. By selectively moving one or a group of selected deflection elements, the shape of the emission light distribution of the light module but also the distribution of light intensity within the emission light distribution can be varied. The emission light distribution is thus dynamically changeable both in terms of its shape (extent or extent) and in terms of its brightness distribution. The control of the deflecting elements and thus the variation of the emission light distribution can be effected as a function of operating parameters of the motor vehicle (eg vehicle speed, load, steering angle, lateral acceleration, etc.). When activating the deflecting elements, environmental parameters of the vehicle (eg outside temperature, precipitation, driving in a city center, on a country road or a motorway, detected other road users in the surroundings of the vehicle, etc.) can also be taken into account.

By selectively controlling the deflection, the Abstrahllichtverteilung can be switched, for example, between the high beam and low beam. In addition, for example, in the area in which there is an oncoming or preceding vehicle or another road user, the light intensity in the emission light distribution can be purposefully reduced, preferably set to zero (so-called partial remote light function). A dazzling of other road users can thus be effectively reduced. Accordingly, it would also be conceivable that in the area in which an object has been detected in front of the vehicle, the light intensity in the Beam light distribution is selectively increased to highlight the object for the driver of the vehicle (so-called marker light). Furthermore, it is conceivable that the deflection elements for realizing a dynamic curve light function of the Abstrahllichtverteilung (horizontal pivoting) or a light width adjustment (vertical pivoting) are driven to the alignment of the Abstrahllichtbündels or the resulting Abstrahllichtverteilung horizontally and / or vertically or the light intensity distribution within the To vary the light distribution. With the aid of the hybrid system or the hybrid light source, a fixed light distribution is generated on the deflection device. This light distribution is projected onto the road and can be switched on and off pixel by pixel or dimmed (eg by rapid switching on and off with a changed ratio of switch-on and switch-off times). Finally, it would even be conceivable to control the deflecting elements for the LED light bundle and the laser light bundle differently, so that at a largely constant position of the part of the emission light distribution generated by the LED light bundle, the concentrated spot area of the emission light distribution produced by the laser light bundle with greater illuminance relative thereto is moved. The spot area can be moved to increase the range upwards and / or for better illumination of side areas of the light distribution, eg. At the roadside, to the side.

In connection with the present invention is often referred to by a so-called. LED light beam and a so-called. Laser light bundle. This designates only from which light source the respective light beam is emitted. Of course, the LED light bundle can be any Wavelengths or colors from the color spectrum of LEDs and the laser light beam can have any wavelengths or colors from the color spectrum of lasers. Furthermore, the LED light beam can also be used for generating a different part of the emission light distribution than for generating a basic light distribution. Likewise, the laser light beam can be used to produce another part of the emission light distribution than to produce a spotlight distribution. It is quite possible that one recognizes no difference between a laser light beam and a LED light beam based on the emitted light.

According to an advantageous development of the present invention, the LED light distribution illuminates a surface on a first side of the conversion device as homogeneously as possible. The LED light distribution preferably illuminates the entire surface on the first side of the conversion device as homogeneously as possible. Thus, the conversion device emits incident light of the LED light distribution also over a large area. This light can be used particularly advantageously for generating a large area in the secondary light beam. In this way, after the deflection of the secondary light bundle by the deflection device, for example, a large-area basic light distribution can be generated as the emission light distribution.

Advantageously, a first optical element for generating a homogeneous surface illumination of the entire surface of the first side of the conversion device is arranged in a beam path of the LED light beam between the at least one LED light source and the conversion device. The optical element deflects the light emitted by the LED light source Light rays on the surface, preferably on the entire surface, the first side of the conversion device. By means of the optically active element, the LED light beam emitted by the LED light source can illuminate the surface of the first side of the conversion device in a particularly homogeneous manner. This can ultimately lead to a particularly homogeneous large-area basic light distribution. The first optical element can in particular be designed as a reflector, for example as a parabolic or elliptical reflector. It is also possible that the optical element is formed as a lens. Preferably, the optical element is a concave mirror or a converging lens.

According to a preferred embodiment of the present invention, the laser light distribution illuminates a luminous spot on a surface of a first side of the conversion device. A light spot is in particular a limited or concentrated area in its extent. Preferably, only a partial area of the surface of the first side of the conversion device is illuminated with the laser light distribution. Thus, the conversion device emits incident light of the laser light distribution also concentrated. This light can be used particularly advantageously for generating a small, particularly brightly illuminated spot area in the secondary light bundle. In this way, after the deflection of the secondary light beam by the deflection device, for example, a concentrated spot can be generated as the emission light distribution. The emission light distribution can also be formed from a superimposition of the basic light distribution generated by the LED light bundle and the spot generated by the laser light bundle.

Advantageously, in a beam path of the Laser light beam disposed between the at least one laser light source and the conversion device, a second optical element for generating the illuminated spot of the laser light distribution on the surface of the conversion device. By means of the optical element, a particularly concentrated laser light beam for generating the spot can be widened and / or the laser light beam can be specifically directed into a specific area on the surface of the first side of the conversion device. The optical element can in particular be designed such that it breaks, scatters, reflects or bundles an incident light beam. In this respect, the second optical element may also be formed as a reflector or as an optical lens.

The first side of the conversion device illuminated as completely as possible by the LED light bundle can produce a particularly large-area homogeneous light intensity distribution in the emission light distribution of the light module. This can be used to generate a base or base light. The concentrated area illuminated by the laser light bundle on the first side of the conversion device can produce a concentrated spot area with high light intensity distribution in the emission light distribution of the light module. The light intensity in the spot area generated by the laser light beam is preferably greater than the light intensity in the base light generated by the LED light beam.

Preferably, the LED light beam emitted from the LED light source and the laser light beam emitted from the laser light source strike the same side of the conversion direction. The laser light distribution and the LED light distribution can be at least partially on the same areas of the surface of the first side of the conversion device, so that the laser light beam and the LED light beam partially mix before they hit the conversion device. This leads, in particular in the transition regions between the regions of the secondary light beam generated by the laser light bundle and the regions of the secondary light beam generated by the LED light bundle and thus also in the emission light distribution of the light module, to a particularly homogeneous overall impression with regard to brightness and / or color.

It is conceivable that the at least one LED light source emits light of a first wavelength, so that the light, for example, appears blue. This light hits the first side of the conversion device and is partially converted to light of a second wavelength, for example yellow light. The unconverted light of the first wavelength is superimposed on the converted light of the second wavelength, resulting in the sum of light of a desired color, for example white light. Of course, the LED light source may also emit differently colored (not blue) light of the first wavelength, which is then partially converted by the conversion device with another wavelength-converting material (non-phosphorus) into light of a second wavelength. An overlay of the unconverted light of the first wavelength and the converted light of the second wavelength gives the light of the desired color.

According to an advantageous embodiment, one of the first side (front side) opposite second side (back) of the conversion device and / or between the first and second sides of the conversion device arranged side surfaces of the conversion device light reflecting surfaces. Light of the LED light beam and / or the laser light beam, which is not directly converted into light for the secondary light beam when hitting the surface of the first side of the conversion device, but would leave the conversion device via the rear side and / or the side surfaces as stray light, is turned on the light reflecting surface of the opposite second side and / or reflected on the light reflecting side surfaces, preferably in the direction of the first side of the conversion device. Thus, light can also be used to generate the emission light distribution, which light is not converted directly into light of the secondary light bundle when it strikes the surface of the first side of the conversion device. This results in a particularly high efficiency of the light module. As materials for the light-reflecting surfaces, in particular metals (Al, Ag) or white-reflecting materials (TiO ₂ , BaSO ₄ ) are proposed. Of course, other materials can be used.

According to a further advantageous refinement, a third optical element is arranged in the beam path of the secondary light beam emitted by the conversion device and designed to direct at least a part of the secondary light beam onto the deflection device. The third optical element makes it possible, in particular, to scatter or bundle the light beams of the secondary light beam in a targeted manner, or to direct them into specific areas on the deflection device. Preferably, the third optical element is arranged in the light module such that the secondary light beam is directed to the deflection device, in particular even if the deflection device is not in a beam path of the outgoing from the conversion device secondary light beam is located. As a result, the deflection device can be arranged largely independently of the conversion device in the light module, and there are further degrees of freedom with regard to the arrangement of these devices in the light module. The third optical element is, for example, a condenser comprising one or more converging lenses or a reflector.

Advantageously, the conversion device comprises a material with wavelength-converting properties, in particular phosphorus or another fluorescent material. If the LED light beam and / or the laser light beam of a first wavelength (a first color) hits the conversion device, the conversion device is excited to phosphorescence or fluorescence and emits light of another second wavelength (of a second color). The conversion device is preferably matched to the spectra of the LED light beam and the laser light beam, so that the light of these light beams is converted as efficiently as possible and used to generate the Abstrahllichtverteilung.

According to an advantageous embodiment, the deflection device comprises a digital micromirror array (Digital Mirror Device, DMD), which comprises a multiplicity of individual elements arrayed next to and / or above one another in the form of micromirrors from which the light generated by a light source is reflected. The micromirrors of a DMD complement each other to form a substantially closed reflection surface. Each micromirror can be individually adjusted in its orientation at least about an axis of rotation, preferably freely in three-dimensional space, ie about two axes of rotation.

Suitable actuators for adjusting the micromirrors are, for example, electrostatic actuators or piezoactuators. It would also be conceivable to make the individual micromirrors magnetizable at least in regions, so that a micromirror or a group of several micromirrors can be adjusted by applying a magnetic field. The micromirrors of a DMD generally each have two stable end positions, between which the micromirror can be switched over within a second to a few thousand times, for example up to 5,000 times. Due to the individual adjustability of the individual micromirrors, it is possible for a light beam incident on one of the micromirrors to be reflected either via the projection optics onto the roadway in the emission light distribution or in another direction in which the light beam makes no contribution to the light bundle incident on the roadway or to the emission light distribution. With a digital micromirror array, therefore, parts of the secondary light bundle can be deflected in a targeted manner and thus the light intensity distribution within the emission light distribution can be influenced virtually as desired. Thus, it is possible not only to switch between low beam and high beam, but it can also be selectively influenced areas of the secondary light beam, for example, to specifically increase the intensity of light in these areas or reduce to complete fading, so that the light intensity distribution in the resulting Abstrahllichtverteilung the light module can be varied almost arbitrarily. In the case of rapid switching back and forth of the micromirrors, the resulting emission light distribution of the light module results averaged over time.

The incident on the micromirror array Secondary light beam is composed of light from the LED light distribution and light from the laser light distribution. The secondary light beam strikes the reflection surface of the micromirror array with a specific secondary light distribution. In the secondary light distribution, the LED light distribution preferably generates a larger illuminated area than the spot-shaped area which is illuminated by the laser light distribution. Such a secondary light distribution, which has a high luminous flux and a center with a particularly high luminance, is particularly well suited for illuminating digital micromirror arrays. A realized by a micromirror array reflector surface is very expensive and must therefore be kept as small as possible. A compact and strong light source with a high luminous flux and a selectively high luminance is therefore advantageous, in particular because luminance and luminous flux directly limit the power of the digital micromirror array. A small-sized DMD is also advantageous when it comes to the realization of a compact as possible light module and thus a compact lighting device.

According to a preferred refinement, the light module has projection optics in order to optically image the emission light distribution of the light module generated by the deflection device on a roadway in front of a vehicle in which the light module according to the invention is installed. The projection optics in particular comprises a reflector or a projection lens.

Preferably, the laser light beam in the emission light distribution generates a concentrated region having a higher illuminance than another region exclusively generated by the LED light beam Abstrahllichtverteilung. In particular, the LED light distribution generates a basic light distribution in the emission light distribution, which illuminates a large area in front of the vehicle, which extends in particular from one side on a roadway edge to another side on an opposite roadway edge. In contrast, the laser light distribution in the emission light distribution generates, in particular, a luminous-light distribution that illuminates a concentrated area with a higher illuminance than the basic-light distribution. The basic light distribution and the luminous light distribution can together form the emission light distribution. This applies both to a low beam distribution and a high beam distribution as well as for any other light distribution. The light-emitting light distribution can be arranged in the center of the emission light distribution, on one or two opposite sides or at any other point of the emission light distribution. Where exactly the luminous spot lies in the emission light distribution depends on the orientation of the corresponding micromirrors upon which falls the part of the secondary light distribution produced by the laser light beam.

Fig. 1a bis 1d

verschiedene an sich aus dem Stand der Technik bekannte Lichtmodule;

Fig. 2

ein Lichtmodul mit einer Umlenkeinrichtung;

Fig. 3a

ein erfindungsgemäßes Lichtmodul gemäß einer ersten bevorzugten Ausführungsform;

Fig. 3b

einen Ausschnitt aus Fig. 3a;

Fig. 4

ein erfindungsgemäßes Lichtmodul gemäß einer zweiten bevorzugten Ausführungsform;

Fig. 5

einen Kraftfahrzeugscheinwerfer;

Further features and advantageous embodiments of the present invention can be taken from the following description with reference to the figures. Show it:

Fig. 1a to 1d

various light modules known per se from the prior art;

Fig. 2

a light module with a deflection device;

Fig. 3a

an inventive light module according to a first preferred embodiment;

Fig. 3b

a section from Fig. 3a ;

Fig. 4

an inventive light module according to a second preferred embodiment;

Fig. 5

a motor vehicle headlight;

The FIGS. 1a to 1d show known from the prior art light modules 1 with an LED light source 2 and a laser light source 3. Such light modules 1 are also referred to as a hybrid system. Directly on the LED 2, within a housing of the LED or directly on the LED chip, a conversion device 4 is arranged in the form of a fluorescent element. The LED 2 illuminates a backside of the fluorescent element 4 and the laser light source 3 illuminates a front side thereof. The fluorescence element 4 radiates excitation to fluorescence by the laser light emitted by the laser light source 3 and the light emitted by the LED light source 2 LED light visible light. For imaging a secondary light beam 6 emitted by the fluorescence element 4 as an emission light distribution 7 (cf. Fig. 1a where by way of example a low-beam light distribution 7 is shown) on a roadway in front of a motor vehicle equipped with the light module 1 is an optical element 5, for example a projection lens (cf. Fig. 1a . 1b, 1d ) or a reflector (cf. Fig. 1c ) intended.

FIG. 2 also shows a light module 1, which is designed as a hybrid system with a laser light source 3 and an LED light source 2. The conversion device 4 is directly on the LED chip or in the housing of the LED 2 arranged. The LED 2 illuminated viewed in the light exit direction, the back of the conversion device 4 and the laser light source 3 a front. The secondary light beam 6 emitted by the conversion device 4 is directed by an optical element, for example a reflector 8, onto a deflection device 8a. From the deflection device 8a, the light of the secondary light bundle 6 reaches a projection optical system 5 and is imaged by the latter in a distribution light distribution 7 on a roadway in front of a motor vehicle equipped with the light module 1. All in the FIGS. 1a to 1d and Fig. 2 shown embodiments have in common that the conversion device 4 is disposed within the housing of the LED 2 or directly on the LED chip.

FIG. 3a shows a light module according to the invention in a first preferred embodiment. The light module is designated in its entirety by the reference numeral 10 and is for installation in a motor vehicle headlight 70 (see. FIG. 5 ) educated. The headlight 70 includes a housing 72, which is preferably made of plastic. In a light exit direction 74, the housing 72 has a light exit opening 76, which is closed by a transparent cover 78. The cover 78 protects the interior of the housing 72 and the headlight components arranged therein from moisture and dirt. The cover plate 78 may be formed as a so-called clear disc without optically effective profiles (for example, prisms or cylindrical lenses). Alternatively, the disc 78 may be provided at least in regions with optically active profiles (so-called diffusion disc). In the interior of the headlight housing 72, an inventive light module 10 is arranged in the illustrated embodiment. The light module 10 is fixed or relative to the spotlight housing 72 movably arranged in the housing 72. In particular, the light module 10 can be arranged to pivot vertically about a horizontal axis (for a headlamp leveling) and / or horizontally pivotable about a vertical axis (for a dynamic cornering function). However, these degrees of freedom can also be realized by a targeted adjustment of the individual DMD elements 50, in particular in the case of a light module 10 which has a DMD as a deflection device 48. The light module 10 generates a desired light distribution, for example a low beam, high beam, position light, daytime running light, or fog light distribution.

The light module 10 comprises at least one LED light source 12, at least one laser light source 14 and a conversion device 16. In the illustrated example, a respective light source 12; 14 is shown. Of course, the light module 10 each also more than the one shown light source 12; 14 have. The LED light source 12 may include one or more LED chips. Several LED chips are preferably arrayed next to and / or above each other. According to the invention, the LED chip or the LED chips of the LED light source 12 are arranged separately and at a distance from the conversion device 16.

The LED light source 12 emits an LED light beam 18 which strikes the conversion device 16. In the example shown, the LED light beam 18 initially strikes a first optically active element 20 and is directed by the latter onto a surface 24 on a first side 26 (front side) of a conversion device 16 (cf. Fig. 3b ). The first optically active element 20 is formed as a concave mirror 22 in the example shown. It could also be designed as a lens, or else a combination of multiple reflectors and / or lenses. The optically active element 20, 22 effects the most homogeneous possible full surface illumination of the entire surface 24 with an LED light distribution 28 generated by the LED light bundle 18.

The laser light source 14 emits a (highly concentrated) laser light beam 30 (so-called laser beam) which strikes the conversion device 16. In the example shown, the laser light beam 30 strikes a second optically active element 32 (FIG. Fig. 3a ) and is also directed by this on the surface 24 on the first side 26 of the conversion device 16. The second optically active element 32 is designed here as a reflector 34. Of course, it may also be designed as a lens, or comprise a combination of a plurality of reflectors and / or lenses. The optically active element 32, 34 effects a punctiform, spot-like illumination of a concentrated area of the surface 24 with a laser light distribution 36 (FIG. 2) generated by the laser light bundle 30 (FIG. Fig. 3b ). It may be necessary to slightly widen the laser beam 30. The laser light distribution 36 preferably illuminates the surface 24 with a light spot 38. The light intensity in the concentrated area of the light spot 38 is greater than in the remaining area of the surface 24 of the conversion device 16.

The LED light source 12 emits light of a particular color or wavelength. In particular, it is proposed that the light emitted by the LED light source 12 is UV (ultraviolet) radiation (in a wavelength range of about 240nm to 450nm, especially 350nm to 450nm) or blue light (in a wavelength range of about 450nm to 500nm) , The Laser light source 14 emits light of a similar wavelength. The conversion device 16 is provided with a fluorescent phosphor. These are, for example, phosphorus or any other fluorescent material. Preferably, the conversion device 16 is tuned to the spectrum of the light generated and emitted by the light sources 12, 14, 18, 30, preferably to a wavelength range between 400 nm and 550 nm. This means that the conversion device 16 has a particularly high efficiency for light of this wavelength.

The light beams 18, 30 emitted by the light sources 12, 14 can be partially (or largely) converted into light of another wavelength as soon as they strike the surface 24 of the conversion device 16. For example, the light of the light sources 12, 14 can be converted to yellow light in a wavelength range between 560nm and 620nm. Together with the unconverted, thus still visible blue light 18, 30, which is scattered without wavelength conversion at the surface 24 of the conversion device 16, resulting from an additive color mixing, a white or whitish light having secondary light beam 40. In a UV laser or a UV LED as a light source is converted into blue and yellow light or in blue, red and green light, so that again results in an additive color mixing white light of the secondary bundle 40.

In the present example, a second side 42 (rear side) of the conversion device 16 opposite the first side is provided with a light-reflecting surface 44. In addition, between the first and second sides 26, 42 disposed side surfaces 46 of the conversion device 16 also have light reflecting surfaces 44. The light rays passing through the surface 24 of the first side 26 of the conversion device 16 are reflected at the light reflecting surfaces 44 and emerge again from the conversion device 16 at the surface 24 of the first side 26. In this case, the reflected light beams with or without conversion to a different wavelength for generating the Abstrahllichtverteilung 7 (see. Fig. 4 ) contribute to the light module 10 so that it has a higher efficiency.

An important aspect of the light module 10 according to the invention is that the conversion device 16 is spatially separated and arranged separately from the light sources 12, 14 in the light module 10. The conversion device 16 can be arbitrarily arranged within the light module 10, for example on any components or optical elements. Of course, the present invention would also work with light of other wavelengths and matched fluorescent materials for the conversion device 16.

The secondary light beam 40 emitted by the conversion device 16 strikes a third optical element 58, which in this example is designed as a converging lens. The third optical element 58 directs the secondary light bundle 40 in the direction of a deflection device 48 (cf. Fig. 4 ). Although the deflection in the Fig. 3a and 3b is not explicitly shown, it is part of the light module 10 shown there according to the first embodiment.

The deflection device 48 comprises a plurality of The part of the secondary light bundle 40 reflected by the deflecting elements 50 generates an emission light distribution 7 of the light module 10. By selectively moving selected deflection elements 50, the shape of the emission light distribution 7 can also be used to distribute the light intensity be varied in the emission light distribution 7. Thus, both the shape and the light intensity distribution in the light beam of the

Abstrahllichtverteilung 7 dynamically changeable. By selectively controlling the deflecting elements 50, the emission light distribution 7 can be switched, for example, between high beam and low beam or any other light distributions. In addition, e.g. in the area in which there is an oncoming or preceding vehicle, the light intensity in the Abstrahllichtverteilung 7 purposefully reduced, preferably set to zero. In particular, dazzling the oncoming traffic can thus be effectively reduced. It is also conceivable, in the area in which an object was detected in front of the vehicle, to increase the light intensity in a targeted manner in order to draw the driver's attention to the object.

In FIG. 4 the deflection device 48 is designed as a digital micromirror array 54 (Digital Mirror Device, DMD). The digital micromirror array 54 consists of a multiplicity of micromirrors 56 arrayed next to and / or above one another, from which the light of the secondary light bundle 40 is reflected. Each micromirror 56 can be individually adjusted in its orientation at least about an axis of rotation, preferably freely in three-dimensional space, ie about two axes of rotation. The micromirrors 56 generally each have two stable ones End positions between which the micromirrors can change up to several thousand times within one second. Due to the individual adjustability of the micromirrors 56, it is possible to specifically deflect certain parts of the secondary light bundle 40 and thus to influence the light intensity distribution within the light bundle of the emission light distribution 7 virtually as desired. Thus, it is possible not only to switch between low beam and high beam, but also individual areas of the secondary light beam 40 can be specifically influenced, for example, to reduce the light intensity in these areas targeted or increase, so that the light intensity distribution in the resulting Abstrahllichtverteilung 7 of the light module 10 in arbitrary areas 7a, 7b can be varied almost arbitrarily.

An important aspect of the present invention is that the at least one LED light source 12 and the at least one laser light source 14 illuminate a common conversion device 16, from which a secondary light beam 40 is emitted onto a deflection device 48. The secondary light bundle 40 is thus composed of light 18 of the LED light distribution 28 and of light 30 of the laser light distribution 36 and strikes the deflecting elements 50 of the deflecting device 48 with a specific secondary light distribution 40. The LED light distribution 28 preferably generates a larger one in the secondary light distribution 40 Illuminated area 7a as the spot-shaped area 7b, which is illuminated by the laser light distribution 36. Such a secondary light distribution 40, which has a high luminous flux and a center with a particularly high luminance, is particularly suitable for illuminating digital micromirror arrays 54. A reflector surface realized by a micromirror array 54 is very large expensive and therefore must be kept as small as possible. A compact and strong light source, such as the laser light source 14, with a high luminous flux and a selectively high luminance is therefore ideal, since luminance and luminous flux directly limit the performance of the digital micromirror array 54.

The third optical element 58 of the light module 10 is formed in this example as a concave mirror 60. The concave mirror 60 directs the secondary light bundle 40 onto the deflection device 48. Starting from the deflection device 48 in the form of the digital micromirror array 54, the emission light bundle 52 is projected by means of projection optics 62, which in this example is a projection lens 64, as emission light distribution 7 on a roadway a vehicle that is equipped with the light module 10 according to the invention. In particular, the projection optics 62 is designed as a condenser 64 which comprises one or two converging lenses.

Claims (12)

A light module (10) for a vehicle headlamp, comprising: - At least one LED light source (12) for emitting an LED light beam (18); - At least one laser light source (14) for emitting a laser light beam (30); - A conversion device (16) which with respect to the light sources (12, 14) is arranged such that the LED light beam (18) with an LED light distribution (28) and the laser light beam (30) with a laser light distribution (36) on the Conversion device (16) meet, and which is designed such that the incident on the conversion device (16) light bundles (18, 30) cause the emission of a secondary light beam (40) from the conversion device (16), characterized in that the Conversion device (16) separately from the at least one LED light source (12) is formed and arranged spatially separated from this, and that the light module (10) in a beam path of the secondary light beam (40) at least one deflection device (48) with a plurality of independently mutually controllable and movable deflecting elements (50) for selectively reflecting at least a portion of the secondary light beam (40) and for generating a Abstrahllichtverteilung (7) of the light module (10). Light module (10) according to claim 1, characterized in that the LED light distribution (28) illuminates a surface (24) on a first side (26) of the conversion device (16) as homogeneously as possible. Light module (10) according to claim 2, characterized in that in a beam path of the LED light beam (18) between the at least one LED light source (12) and the conversion device (16), a first optical element (20) for generating a homogeneous planar Illumination of the entire surface (24) of the first side (26) of the conversion device (16) is arranged. Light module (10) according to one of claims 1 to 3, characterized in that the laser light distribution (36) illuminates a light spot (38) on a surface (24) of a first side (26) of the conversion device (16). Light module (10) according to claim 4, characterized in that in a beam path of the laser light beam (30) between the at least one Laser light source (14) and the conversion device (16) a second optical element (32) for generating the illuminated spot (38) of the laser light distribution (36) on the surface (24) of the conversion device (16) is arranged. Light module (10) according to one of claims 2 to 5, characterized in that one of the first side (26) opposite the second side (42) of the conversion device (16) and / or between the first and second sides (26, 42) arranged side surfaces (46) of the conversion device (16) comprise light-reflecting surfaces (44). Light module (10) according to one of claims 1 to 6, characterized in that in the beam path of the secondary light beam (40), a third optical element (58) is arranged and formed, at least a part of the secondary light beam (40) on the deflection device (48). to steer. Light module (10) according to one of claims 1 to 7, characterized in that the conversion device (16) comprises a material with wavelength-converting properties, in particular phosphorus or another fluorescent material. Light module (10) according to one of claims 1 to 8, characterized in that the deflection device (48) a digital micromirror array (54), hereinafter referred to as Digital Mirror Device or DMD, arranged with a plurality of array-like juxtaposed and / or one above the other, individually or in groups controllable micromirrors (56). Light module (10) according to one of claims 1 to 9, characterized in that the light module (10) has a projection optics (62) to a by the deflection (48) generated Abstrahllichtbündel (52) as Abstrahllichtverteilung (7) of the light module (10) on a roadway in front of a vehicle in which the light module (10) is installed, optically image. Light module (10) according to any one of claims 1 to 10, characterized in that the laser light beam (30) in the emission light distribution (7) generates a concentrated area (7b) with a higher illuminance than a generated exclusively by the LED light beam (18) another area (7a) of the emission light distribution (7). Motor vehicle headlight (70) comprising a housing (72) with a by a transparent cover (78) closed light exit opening (76) and at least one in the housing (72) arranged light module (10) for generating a Abstrahllichtverteilung (7), which through the cover (78) on a roadway in front of a motor vehicle equipped with the headlight (70) passes, characterized in that the light module (10) according to one of claims 1 to 11 is formed.

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