EP3686483A1 - Lighting device for a motor vehicle headlight - Google Patents

Abstract

Lighting device (10) for a motor vehicle headlight, the lighting device comprising: - at least a first light source (50) for emitting light beams in a first emission direction (X1), - a first deflection device (100) with a deflection surface (110), which is set up for this purpose is to deflect at least part of the light beams of the at least one first light source (50) in a second radiation direction (X2), and - a second deflection device (200) with a plurality of independently controllable and movable deflection elements for deflecting at least a part of the light beams light beams deflected by the first deflection device (100) in a third emission direction (X3) and for generating a light distribution in front of the lighting device (10), the first deflection device (100) comprising at least one second light source (60) which has at least one second light source ( 60) has a main emission direction, in we The light rays of the second light source can be emitted, the at least one second light source (60) being arranged on the deflection surface (110) of the first deflection device (100) in such a way that the main emission direction is parallel to the second emission direction (X2).

Description

• zumindest eine erste Lichtquelle zur Ausstrahlung von Lichtstrahlen in eine erste Abstrahlrichtung,
• eine erste Umlenkeinrichtung mit einer Umlenkfläche, welche dazu eingerichtet ist, zumindest einen Teil der Lichtstrahlen der zumindest einen ersten Lichtquelle in eine zweite Abstrahlrichtung umzulenken, und
• eine zweite Umlenkeinrichtung mit einer Vielzahl von unabhängig voneinander ansteuerbaren und bewegbaren Umlenkelementen zum Umlenken zumindest eines Teils der Lichtstrahlen der von der ersten Umlenkeinrichtung umgelenkten Lichtstrahlen in eine dritte Abstrahlrichtung und zur Erzeugung einer Lichtverteilung vor die Beleuchtungsvorrichtung.

The invention relates to a lighting device for a motor vehicle headlight, the lighting device comprising:

• at least one first light source for emitting light rays in a first emission direction,
• a first deflection device with a deflection surface, which is set up to deflect at least some of the light beams of the at least one first light source into a second radiation direction, and
• a second deflection device with a plurality of independently controllable and movable deflection elements for deflecting at least some of the light beams of the light beams deflected by the first deflection device into a third radiation direction and for generating a light distribution in front of the lighting device.

The invention further relates to a motor vehicle headlight, comprising at least one lighting device according to the invention.

In the development of the current headlight systems, the focus is increasingly on the desire to be able to project a high-resolution light image onto the road, which can be changed quickly and adapted to the respective traffic, road and light conditions.

The term "roadway" is used here for the purpose of simplified illustration, because of course it depends on the local conditions whether a photograph is actually on the roadway or extends beyond it, for example on the edge of the roadway.

In principle, the light image is described on the basis of a projection onto a vertical surface in accordance with the relevant standards relating to automotive lighting technology, with a variably controllable reflector surface consisting of a plurality of micromirrors is formed and reflects light rays emitting from a first illuminant in a radiation direction of the headlight.

Any light functions with different light distributions can be implemented, such as a low beam light distribution, a cornering light light distribution, a city light light distribution, a motorway light light distribution, a cornering light light distribution, a high beam light distribution or the mapping of glare-free high beam. Furthermore, symbol projections can also take place, such as danger symbols, navigation arrows, manufacturer logos or the like.

For the micromirror arrangement, the so-called "digital light processing" projection technology - DLP for short - is preferably used, in which images are generated by modulating a digital image onto a light beam. In this case, a rectangular arrangement of movable micromirrors, also referred to as pixels, divides the light beam into partial areas and then reflects or deflects it pixel by pixel either into the projection path or out of the projection path.

The basis for this technology is preferably an optoelectronic component which contains the rectangular arrangement in the form of a matrix of micromirrors and their control technology, for example a "digital micromirror device" - DMD for short.

A DMD microsystem is an area light modulator (Spatial Light Modulator, SLM) that consists of micro-mirror actuators arranged in a matrix, i.e. tiltable or pivotable reflecting surfaces, for example with an edge length of about 7 microns. The mirror surfaces are designed in such a way that they can be moved by the action of electrostatic fields.

Each micromirror can be individually adjusted in angle and generally has two stable end states, between which it is possible to switch up to 5000 times within a second, for example.

The number of micromirrors corresponds to the resolution of the projected image, whereby a micromirror can represent one or more pixels. DMD chips with high resolutions in the megapixel range are now available.

In currently used motor vehicle headlights, the light distribution generated, for example for a glare-free high beam, can be dynamically controlled such that oncoming vehicles are detected and the light distribution generated, for example, by a matrix of LED light sources is darkened in the direction of the oncoming vehicle.

In general, there is the problem in the area of high-resolution lighting systems, in particular in the area of DMD technology, that a fully functional light function cannot be expected due to restrictions due to the light source that can be used for illuminating the DMD. In particular, a fully functional high beam with a high maximum (greater than 100 lx) and a width of +/- 20 ° (measured according to an ECE measuring screen) cannot be achieved. The high beam distribution that can be generated by a DMD or DLP module is relatively narrow with a maximum expected width of +/- 10 °.

For this reason, additional modules must be added, which generate the full width of the high beam or high beam distribution, these additional modules typically have to be placed anywhere in the headlight and are undesirable in terms of design and the space taken up in the motor vehicle headlight.

It is an object of the invention to provide an improved lighting device.

This object is achieved in that the first deflection device comprises at least one second light source, which at least one second light source has a main emission direction in which light rays from the second light source can be emitted, the at least one second light source being arranged on the deflection surface of the first deflection device in this way, that the main radiation direction is parallel to the second radiation direction.

The at least one first light source is configured, for example, to implement basic lighting or apron lighting in front of the lighting device, the at least one second light source being provided to generate an additional light spot, for example for high beam distribution in front of the lighting device, or to the first deflection device map.

The main emission direction of the at least one second light source should be as close as possible or almost parallel or completely parallel to the second emission direction, since the second deflection device - if it is designed as a DMD - is specified with very small light entry angle ranges, i.e. If light rays hit the DMD micromirrors too steeply or too flatly, this can lead to backlighting of the micromirrors, which in turn leads to scattered light in the projecting light image and thus to poor light-dark contrast, which is extremely important when used for a motor vehicle headlight.

Small angular deviations - as long as they are within the specified angular range of the DMD - are however permissible and geometrically necessary when using two second light sources (due to the offset of the light sources to each other).

It should be noted that the term “projectable in front of the lighting device” means projecting in the direction of travel of a motor vehicle in which the lighting device is installed.

In this context, the term “direction of travel” denotes the direction in which a driven motor vehicle moves as designed. In this context, a technically possible reversing is not defined as the direction of travel.

“Main emission direction” is to be understood as the direction in which the first or the second light source emits the most or the most light due to its directivity.

It can advantageously be provided that the at least one second light source is arranged in the geometric center of the deflection surface of the first deflection device. wherein the deflection surface preferably has a recess for the at least one second light source.

The geometric center is also understood to mean, for example, the geometric center of gravity. This corresponds mathematically to the averaging of all points within a figure, in this case a surface. Such surfaces can, for example, also be designed as quadrics, that is to say surfaces of second order.

The point in the case of a paraboloid (or hyperboloid) in which the axis of rotation about which a parabola (or hyperbola) is rotated to produce a paraboloid intersects the paraboloid surface is also understood as a geometric center, for example.

The first deflection device can, for example, be designed such that it or the deflection surface has an opening or opening through which the at least one second light source can emit light beams onto the second deflection device.

It can be provided that the first deflection device has a holder on which the deflection surface is arranged, the holder having an opening in which the at least one second light source is arranged.

In a practical embodiment of the invention it can be provided that the holder is designed as a heat sink and is designed to dissipate the heat generated at the at least one second light source.

It can be favorable if the first deflection device has exactly one second light source.

It can be provided that the at least one second light source is designed as a light-emitting diode or as a laser light source with a light conversion means.

Since laser devices generally emit coherent, monochromatic light or light in a narrow wavelength range, but in a motor vehicle headlight, white mixed light is generally preferred or prescribed by law for the emitted light, so-called light conversion elements for converting essentially monochromatic light are in the direction of radiation of the laser device Light arranged in white or polychromatic light, whereby “white light” is understood to mean light of such a spectral composition which produces the color impression “white” in humans. This light conversion element is designed, for example, in the form of one or more photoluminescence converters or photoluminescence elements, with incident laser beams from the laser device striking the light conversion element, which as a rule has photoluminescent dye, and excite this photoluminescent dye for photoluminescence, and thereby light in a wavelength different from the light of the irradiating laser device Emits wavelength ranges. The light output of the light conversion element essentially has characteristics of a Lambertian radiator.

With light conversion elements, a distinction is made between reflective and transmissive conversion elements.

The terms "reflective" and "transmissive" refer to the blue portion of the converted white light. In the case of a transmissive structure, the main direction of propagation of the blue light component after passing through the converter volume or conversion element is essentially the same direction as the direction of propagation of the output laser beam. In the case of a reflective structure, the laser beam is reflected or deflected at an interface attributable to the conversion element, so that the blue light component has a different direction of propagation than the laser beam, which is usually designed as a blue laser beam.

It can furthermore be provided that the at least one second light source has a front lens system, which front lens system is designed as a collimator.

A collimator is understood to mean such a device which is set up to align light beams parallel to one another.

Advantageously, provision can be made for the at least one first light source to be followed by a front lens system.

The attachment optics are thus located in the beam path of the first light source between the first light source and the first deflection device.

It can be provided here that the front lens system is designed as a collimator.

It can advantageously be provided that the second deflection device is designed as a digital micromirror array with a plurality of micromirrors which can be arranged next to one another in the manner of an array and can be controlled individually or in groups.

Each micromirror can be individually adjusted in its angle and usually has two stable end states between which it can be tilted.

The second deflection device can advantageously be designed as a DMD.

By moving individual or a group of selected deflection elements in a targeted manner, the shape of the radiation light distribution of the lighting device, but also the light intensity distribution within the radiation light distribution, can be varied. The radiation distribution can thus be changed dynamically both in terms of its shape (extension and / or extension) and in terms of its brightness distribution. The control of the deflection elements, and thus the variation of the light distribution, can take place depending on the operating parameters of the motor vehicle (e.g. vehicle speed, loading, steering angle, lateral acceleration, etc.). When controlling the deflection elements, environmental parameters of the vehicle (e.g. outside temperature, precipitation, other road users detected in the vehicle's surroundings, etc.) can also be taken into account.

It can be provided that the at least one first light source is designed as at least one light-emitting diode.

It is preferably provided that in the event that two or more light emitting diodes are provided, each light emitting diode can be controlled independently of the other light emitting diodes.

Each light-emitting diode can thus be switched on and off independently of the other light-emitting diodes of a light source, and preferably, if the light-emitting diodes are dimmable, can also be dimmed independently of the other light-emitting diodes of the light source.

It can further be provided that the lighting device comprises at least two first light sources, preferably exactly two first light sources.

It can be advantageous if the first radiation direction is parallel to the third radiation direction.

It can be provided that the deflection surface of the first deflection device is designed as a hyperbolic or as a parabolic reflector.

In principle, the deflection surface can also have other shapes, for example an ellipsoid.

It can be provided that the first deflection device bundles light beams from the at least one first light source to a point which is located behind the second deflection device in the direction of the second radiation direction.

The object is also achieved by a motor vehicle headlight with at least one lighting device according to the invention.

• Fig. 1 eine perspektivische Ansicht einer beispielhaften Beleuchtungsvorrichtung mit ersten Lichtquellen, einer ersten Umlenkeinrichtung mit einer zweiten Lichtquelle und eine zweite Umlenkeinrichtung;
• Fig. 2 die beispielhafte Beleuchtungsvorrichtung aus Fig. 1 in einer anderen Perspektive;
• Fig. 3 einen Schnitt durch die erste Umlenkeinrichtung;
• Fig. 4 eine perspektivische Vorderansicht der ersten Umlenkeinrichtung; und
• Fig. 5 eine perspektivische Rückansicht der ersten Umlenkeinrichtung.

The invention is explained in more detail below using exemplary drawings. Here shows

• Fig. 1 a perspective view of an exemplary lighting device with first light sources, a first deflection device with a second light source and a second deflection device;
• Fig. 2 the exemplary lighting device Fig. 1 in a different perspective;
• Fig. 3 a section through the first deflection device;
• Fig. 4 a perspective front view of the first deflection device; and
• Fig. 5 a rear perspective view of the first deflection device.

Fig. 1 shows an exemplary lighting device 10 for a motor vehicle headlight, the lighting device 10 comprises two first light sources 50 , which are provided for emitting light beams in a first emission direction X1 and are designed as light-emitting diodes, and a first deflection device 100 with a deflection surface 110 , which deflection surface 110 is set up for this purpose is to deflect at least some of the light beams of the first light sources 50 into a second emission direction X2 . The first deflection device 100 further comprises a holder 130 , on which holder 130 the deflection surface 110 is arranged or fastened.

The first light sources 50 are each followed by a front lens system 51 , which front lens systems 51 are designed as collimators and align the light beams emitted by the light sources 50 parallel to one another, the parallel light beams being emitted onto the first deflection device 100 or onto the deflection surface 110 .

The lighting device 10 further comprises a second deflection device 200 , which is designed as a digital micromirror array (DMD for short) with a multiplicity of micromirrors which can be arranged next to one another in an array, individually or in groups, the micromirrors being controllable and movable independently of one another, and the micromirrors for deflecting at least part of the light beams of the light beams deflected by the first deflection device 100 are provided in a third radiation direction X3 and for generating a light distribution in front of the lighting device 10 .

Each micromirror can be individually adjusted in its angle and usually has two stable end states between which it can be tilted.

The first radiation direction X1 can, as in the example shown in FIGS Figures 1 and 2nd can be arranged parallel to the third radiation direction X3.

Fig. 3 shows a more detailed sectional view of the first deflection device 100 , wherein it can be seen that the first deflection device 100 comprises a second light source 60 , which has a main emission direction A , into which light beams of the second light source 60 can be emitted, the second light source 60 being in the geometric center of FIG Deflection surface 110 is arranged. For this purpose, the holder 130 has an opening 140 , in which the second light source 60 is arranged, the deflection surface 110 having a recess 120 for the second light source 60 , so that the light beams emitted by the second light source 60 in the direction of the second emission direction X2 second deflection device 200 can be emitted. The main emission direction A of the second light source 60 is arranged parallel to the second emission direction X2 or emits the second light source 60 essentially in the same direction in which the light rays of the first light sources 50 are deflected by the first deflection device 100 .

The geometric center is also understood to mean, for example, the geometric center of gravity. This corresponds mathematically to the averaging of all points within a figure, in this case a surface. Such surfaces can, for example, also be designed as quadrics, that is to say surfaces of second order.

The deflection surface 110 can be designed, for example, as a parabolic or as a hyperbolic reflector or reflector surface.

The point in the case of a paraboloid (or hyperboloid) in which the axis of rotation about which a parabola (or hyperbola) is rotated to produce a paraboloid (or hyperboloid) intersects the paraboloid surface (hyperboloid surface) can also be understood as a geometric center .

The deflecting surface 110 or the first deflecting device 100 can also be designed such that the light beams of the first light sources are essentially focused on one point, which point is located behind the second deflecting device 200 in the direction of the second emission direction X2 .

This point can also be understood to mean an area with a spatial extent, which generally means that the parallel light beams of one of the first light sources 50 intersect the parallel light beams of the other first light source 50 in one point or area.

In the example shown in the figures, the second light source 60 is designed as a laser light source with a light conversion element, the second light source 60 being followed by an auxiliary lens 61 in the main emission direction A , which is designed as a collimator.

Fig. 4 shows a perspective front view of the first deflection device 100 , the deflection surface 110 and the recess 120 provided on the deflection surface 110 being recognizable once again.

Fig. 5 shows a perspective rear view of the first deflection device 100 , wherein the holder 130 can be seen more clearly, the holder 130 being designed as a heat sink, which heat sink is designed to dissipate the heat generated at the second light source 60 , preferably to the surroundings. LIST OF REFERENCES Lighting device 10th First light source 50 Front optics first light source 51 Second light source 60 Front optics second light source 61 First deflection device 100 Deflection surface 110 Recess deflection surface 120 bracket 130 Opening bracket 140 Second deflection device 200 First direction of radiation X1 Second direction of radiation X2 Third radiation direction X3 Main emission direction A

Claims (15)

A lighting device (10) for a motor vehicle headlight, the lighting device comprising: - at least one first light source (50) for emitting light beams in a first emission direction (X1), a first deflection device (100) with a deflection surface (110), which is set up to deflect at least some of the light beams of the at least one first light source (50) into a second emission direction (X2), and - a second deflection device (200) with a plurality of deflection elements which can be controlled and moved independently of one another for deflecting at least some of the light beams of the light beams deflected by the first deflection device (100) into a third radiation direction (X3) and for generating a light distribution in front of the lighting device ( 10), characterized in that
the first deflection device (100) comprises at least one second light source (60), which has at least one second light source (60) having a main emission direction, in which light rays from the second light source can be emitted, the at least one second light source (60) being in this way on the deflection surface ( 110) of the first deflection device (100) is arranged such that the main emission direction is parallel to the second emission direction (X2). Lighting device according to claim 1, characterized in that the at least one second light source (60) is arranged in the geometric center of the deflection surface (110) of the first deflection device (100), the deflection surface (110) preferably having a recess (120) for the at least one has second light source (60). Lighting device according to claim 1 or 2, characterized in that the first deflection device (100) has a holder (130) on which the deflection surface (110) is arranged, the holder (130) having an opening (140) in which the at least one second light source (60) is arranged. Lighting device according to claim 3, characterized in that the holder (130) is designed as a heat sink and is designed to dissipate the heat generated at the at least one second light source (60). Lighting device according to one of claims 1 to 4, characterized in that the first deflection device (100) has exactly a second light source (60). Lighting device according to one of claims 1 to 5, characterized in that the at least one second light source (60) is designed as a light-emitting diode or as a laser light source with a light conversion means. Lighting device according to one of claims 1 to 6, characterized in that the at least one second light source (60) has an attachment lens (61), which attachment lens (61) is designed as a collimator. Lighting device according to one of claims 1 to 7, characterized in that the at least one first light source (50) is followed by an attachment lens (51), which attachment lens (51) is preferably designed as a collimator. Lighting device according to one of claims 1 to 8, characterized in that the second deflection device (200) is designed as a digital micromirror array with a plurality of micromirrors which can be controlled next to one another and arranged in an array or individually. Lighting device according to one of claims 1 to 9, characterized in that the at least one first light source (50) is designed as at least one light-emitting diode. Lighting device according to one of claims 1 to 10, characterized in that the lighting device (10) comprises at least two first light sources (50), preferably exactly two first light sources (50). Lighting device according to one of claims 1 to 11, characterized in that the first radiation direction (X1) is parallel to the third radiation direction (X3). Lighting device according to one of claims 1 to 12, characterized in that the deflection surface (110) of the first deflection device (100) is designed as a hyperbolic or as a parabolic reflector. Illumination device according to one of Claims 1 to 13, characterized in that the first deflection device (100) bundles light beams from the at least one first light source (50) onto a point which is behind the second deflection device (200) in the direction of the second emission direction (X2). located. Motor vehicle headlight with at least one lighting device according to one of claims 1 to 14.

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