EP3140591B1 - Generating a light emission pattern in a far field - Google Patents

Description

The invention relates to a lighting device for a headlight for generating a Lichtabstrahlmusters in a far field, comprising at least one phosphor surface and at least one spaced from the phosphor surface light source for emitting primary light for illuminating the phosphor surface, whereby an associated Lichtabstrahlmuster can be generated. The invention is particularly applicable to a vehicle headlamp, especially for a passenger or truck.

WO 2011/160680 A1 discloses a light source assembly comprising a primary light source and a secondary light source, the primary light source configured to illuminate the secondary light source, the secondary light source comprising a polyhedron having at least first and second phosphor surfaces, wherein the primary light source comprises at least one laser or light emitting diode; wherein a drive mechanism is attached to the primary light source or to the secondary light source.

US 2006/0227087 A1 discloses laser display systems that generate at least one scanning laser beam to produce one or more phosphors on a screen that emits light to form images. The phosphor materials may include phosphor materials.

EP 2 359 605 B1 discloses a luminous means having at least one semiconductor laser adapted to emit primary radiation having a wavelength between 360 nm and 485 nm inclusive, and at least one conversion means downstream of the semiconductor laser and adapted to convert at least a portion of the primary radiation into secondary radiation with one of the The radiation emitted by the lamp radiation has an optical coherence length which is at most 50 microns, wherein the conversion agent has a concentration of color centers or luminous dots, which is at least 10 ^ 7 / μm ^ 3 and the color centers or Luminous dots are statistically distributed in the conversion means, and wherein a radiated from the primary radiation focal spot of the conversion means has an area of at most 0.5 square millimeters.
The WO 2013/164276 A1 discloses a vehicle lighting device having at least one semiconductor light source and at least one can be irradiated by the semiconductor light source reflector device each having at least one tiltable reflector element, wherein at least one tiltable reflector element is coated with phosphor. The reflector device can also be adjustable, in particular longitudinally displaceable or rotatable about one or more axes.
It is the object of the present invention to at least partially overcome the disadvantages of the prior art, and in particular to provide an improved possibility for the multi-faceted adjustment of a Lichtabstrahlmusters means of a "remote phosphor" device.

This object is solved according to the features of the independent claim. Preferred embodiments are in particular the dependent claims.

This lighting device has the advantage that it can be switched with a comparatively small design effort between different Lichtabstrahlmustern.

The fact that the fluorescent surfaces can be introduced into the illumination surface comprises that the fluorescent surfaces are arranged at a distance from the at least one light source. This corresponds to a "remote phosphor" arrangement.

In particular, the far field may be a field or space at a distance of at least two meters to a distance of several hundred meters in front of the headlight.

The illumination surface may correspond in particular in size and extent and shape factor to a light spot generated by the primary light.

A phosphor surface has at least one phosphor or conversion (color) substance which at least partially converts or converts the primary light incident thereon into secondary light of different wavelength, in particular of a larger wavelength. This wavelength conversion is basically known and need not be further elaborated here. For example, a phosphor may partially convert incident blue primary light into yellow secondary light, so that a total of blue-yellow or white mixed light with corresponding proportions of primary light and secondary light is radiated from the phosphor surface. In principle, however, a full conversion is possible.

That phosphor surfaces are different may include, in particular, that they have a different shape, a different type of phosphor (s) and / or a different phosphor distribution. The different phosphor distribution may include a different concentration of the phosphor and / or a different thickness of the phosphor surface. The Different types of phosphor may include completely different phosphors (eg phosphor A in one phosphor surface and phosphor B in another phosphor surface) or partially different phosphors (eg phosphor A in one phosphor surface and phosphors A and B in another phosphor surface). Different fluorescent surfaces cause correspondingly different light emission patterns when irradiated with primary light. Thus, to generate a light emission pattern with inhomogeneous color distribution, at least one associated phosphor surface may be inhomogeneously coated with at least one phosphor, eg with an inhomogeneous layer thickness and / or an inhomogeneous phosphor concentration of at least one phosphor, in particular over a large area. By changing a light color of the light emission pattern by means of a different phosphor distribution of two alternately illuminable phosphor surfaces, in turn, certain boundary conditions of the vehicle and / or the driver can be better taken into account. For example, the light color can be adapted to the presence of fog or rain, but also, for example, to a combination of fog or rain with an old or a young driver. Also, the peculiarities of color blind or partially color blind (eg with a red / green weakness) can now be considered. This, in turn, can achieve greater traffic safety. It may also be additional comfort for the driver or passengers are generated.

At least one phosphor surface may have a uniform distribution of phosphor. This enables a uniformly illuminating light emission pattern.

Additionally or alternatively, at least one phosphor surface may have a non-uniform distribution of at least one phosphor. This allows in a particularly simple manner, for example, in terms of brightness and / or a light color multi-shaped Lichtabstrahlmuster. In particular, at least one phosphor surface may comprise a plurality of phosphors which are distributed unevenly over the phosphor surface. As a result, multi-colored light emission patterns can be provided in a particularly simple manner. If a partial region of the dye surface has partial regions in which a plurality of phosphors are present, it is easy to produce a light emission pattern with subregions that merge into one another. However, a phosphor surface may also have separate subregions with different phosphor concentrations and / or phosphors or phosphor mixtures. Additionally or alternatively, the subregions with different phosphor concentrations may adjoin one another and fill at least one subarea of the illumination surface in a coherent manner. For this purpose, for example, partial areas with a hexagonal-polygonal structure and / or as a combination of different geometric shapes are provided, in particular in the sense of a complete "tesselation" (eg a so-called "Penrose tesselation").

The plurality of phosphor surfaces are arranged on a plurality of translationally displaceable carriers. This results in the advantage that a position of the phosphor surfaces in a mechanically simple manner, namely by means of a displacement of the at least one carrier, is variable. In particular, a particular translational position of the carrier may correspond to an associated Lichtabstrahlmuster.
The phosphor surfaces may, for example, be arranged in layers or as a layer or layer system on the carrier. The carrier may have a plate-like or disc-like basic shape. The carrier preferably consists of a highly conductive material, for example of metal or sapphire, for effective heat removal from the phosphor. The wearer may be cooled.

It is a development that from each phosphor surface, white or whitish light, in particular by only partial conversion generated mixed light, can be emitted. As a result, in particular phosphor surfaces can be excluded in which the mixed light is generated only after the phosphor surface by superposition, e.g. in that different colored radiation generated by the phosphor surface comes together behind or behind the phosphor surface. For example, phosphor surfaces can be excluded so as to have closely juxtaposed (narrowly localized) regions with different phosphors (e.g., in stripe form or grouped as pixels), the phosphors producing secondary light with respective color fractions of the blend light. Therefore, in particular strips or pixels with primary color-producing phosphors, e.g. the primary colors red, green and / or blue (RGB color space) or cyan, magenta and / or yellow (CMY color space).

However, use of two phosphors with different colors of the secondary light generated by them is also conceivable in principle, e.g. for a change between a daytime running light or a parking light with white color and a turn signal function (for example for a direction change display) with yellow color.

It is a further development that the light reflected or backscattered by the phosphor surface is used as useful light for generating the light emission pattern in the far field ("reflective arrangement"). This may mean in particular that this light of the phosphor surface is selectively reflected (eg by attachment to a reflective support). Alternatively or additionally, the light emerging at the side of the phosphor surface facing away from the incident primary light may be used as useful light for generating a light emission pattern in the far field ("transmitted light arrangement" or "transmissive arrangement").

The at least one light source is basically not limited in its kind. For particularly effective wavelength conversion, a light source having a narrow spectral band is preferred, such as semiconductor light sources, e.g. a light emitting diode (LED) or in particular a laser diode. It is a development that at least one light source is a semiconductor light source. In one variant, the at least one semiconductor light source comprises at least one light-emitting diode. The at least one light-emitting diode may itself contain at least one wavelength-converting phosphor (conversion LED). The at least one light-emitting diode can be in the form of at least one light-emitting diode or in the form of at least one LED chip. Several LED chips can be mounted on a common substrate ("submount"). Instead of or in addition to inorganic light emitting diodes, e.g. based on InGaN or AlInGaP, organic LEDs (OLEDs, for example polymer OLEDs) can generally also be used. Alternatively, the at least one semiconductor light source may be e.g. have at least one diode laser or be such. The at least one semiconductor light source may be equipped with at least one own and / or common optics for beam guidance, e.g. at least one Fresnel lens, collimator, and so on.

The primary light generated by at least one light source may be split into two or more different light beams, e.g. by means of a beam splitter. The light of several light sources may alternatively or additionally be combined or combined in a light beam.

The control device may be coupled to at least one motor for moving the phosphor surfaces or may have at least one such motor. The at least one motor may in particular translate at least one carrier for the phosphor surfaces translationally, in particular linearly. The control device may be electronics. The control device may be part of a lighting device which can be installed as a module in the vehicle or may be provided in the vehicle and connected thereto after installation of a lighting device, in particular with a motor of the lighting device.

It is a development that at least two phosphor surfaces are arranged at a distance from each other, e.g. separated by a gap or an edge or a corner. It is still a further development that at least two phosphor surfaces are arranged directly adjacent to one another, e.g. arranged virtually gap-free adjacent or formed as subregions of a consistently formed larger (multiple or group) fluorescent surface.

The shape of a phosphor surface is not limited and may be at least partially planar or curved. The phosphor surface may be freely shaped and e.g. have multiple facets. Also, fluorescent surfaces may protrude from the ground plane, for example by tilting or tilting.

The phosphor surface may be preceded by a stationary or co-displaceable optics, for example for beam shaping and / or spectral filtering of a light beam incident on the phosphor surface and / or beam shaping and / or spectral filtering of a light emitted by the phosphor surface (including a mixed light). The optics may have one or more optical elements, e.g. at least one lens, at least one concentrator, at least one collimator, at least one reflector, at least one aperture, at least one filter, etc.

It is also a further development that at least one currently illuminable phosphor surface (which is thus located within the illumination surface) has optics for directing the light emitted by the at least one phosphor surface is connected downstream of the far field. This downstream ("secondary") optic is in particular not rotatable together with the phosphor surfaces and serves, for example, for beam shaping and / or spectral filtering of the light emitted by the phosphor surface (including a mixed light). The optics may have one or more optical elements, for example at least one lens, concentrator, collimator, reflector, aperture, filter, etc. If a plurality of phosphor surfaces illuminate, they may illuminate the same and / or different regions of the downstream optics.

It is also a development that the lighting device has at least one shell-like reflector, which is connected downstream of at least one currently illuminated phosphor surface. The at least one currently illuminable phosphor surface is preferably located in the region of a focal spot of the reflector illuminated by it.

In particular, at least two light emission patterns may have a different white light color. It is a development that they have the same shape. Thus, a light-emitting pattern may only be changed in color, e.g. to adapt to changed lighting conditions.

It is also possible to provide two disjoint (non-overlapping) portions of a phosphor surface with different phosphors each homogeneous.

It is an embodiment that at least one phosphor surface can be moved into the illumination surface by means of a pure translational movement (that is to say without a rotational component). The at least one phosphor surface thus retains its orientation in space. This makes it possible to achieve a particularly simple movement.

A trajectory or trajectory of the at least one phosphor surface is basically arbitrary and therefore may also be curved. The trajectory may be in a three-dimensional space or in a plane. For a particularly simple movement, the translation movement may be a linear or rectilinear translational movement.

In addition, the translational movement may be superimposed by a rotational movement of the at least one phosphor surface, in particular in order to achieve a pivoting of the phosphor surface. Also, instead of or in addition to a linear translational movement, at least one phosphor surface displaced on a curved trajectory or trajectory may be used.

It is still an embodiment that at least one phosphor surface is movable by means of a translational movement and additionally a rotational movement in the illumination surface. This also includes a pivoting movement of the at least one phosphor surface. The rotational movement may include a fulcrum or a rotation axis within the at least one phosphor surface, within a carrier of the phosphor surface, or spaced therefrom.

However, lighting devices are excluded in which a movement of the at least one phosphor surface, in particular of all phosphor surfaces, can be described purely by rotation, in particular by a solid or fixed to the light fulcrum or to describe a space fixed axis of rotation.

It is still an embodiment that a Lichtabstrahlmuster by means of at least one stationary aligned primary light beam (ie "static") can be generated. This means in particular that a light path of at least one primary light beam does not change with time, but remains stationary or fixed. The Lichtabstrahlmuster is generated completely in particular at any time. This embodiment is particularly easy to implement.

It is a development that is particularly preferred for this embodiment that the at least one primary light beam has a significant cross-sectional size. This results in the advantage that the primary light beam can simultaneously illuminate a large area of the at least one phosphor surface which can currently be illuminated in the determined position.

It is also an embodiment that a Lichtabstrahlmuster by means of a movement of at least one primary light beam (ie "dynamic") can be generated. This makes possible - in particular line by line - scanning or "scanning" illumination of the phosphor surface, in which at least one primary light beam successively illuminates different regions of the at least one phosphor surface. As a result, differently shaped light emission patterns can be generated by means of a same phosphor surface located in the same position. It is also possible to perform the movement of the primary light beam non-resonant, so not periodically to describe lines and columns, but to handle the movement of the primary light beam completely free.

It is a further embodiment that a plurality (ie, at least two) phosphor surfaces are arranged on at least one common, translational, in particular linear, displaceable or movable carrier. This results in the advantage that a position of all phosphor surfaces of the common carrier in a mechanically simple manner, namely by means of a displacement of this carrier, is changeable. In particular, a particular translational, in particular linear, position of the carrier may correspond to an associated light emission pattern. This embodiment comprises that all the phosphor surfaces are arranged on exactly one common carrier. This embodiment also includes that the phosphor surfaces are arranged on a plurality of carriers, wherein at least one Carrier, in particular on a plurality of carriers, in each case at least two phosphor surfaces are arranged.

It is yet a further embodiment that the at least one translationally, in particular linear, displaceable carrier has a plurality of translucent, in particular linear, displaceable carrier, each having a plurality of phosphor surfaces, wherein in the illumination surface in each case a respective fluorescent surface of a respective carrier can be introduced. Consequently, the light emission pattern of the lighting device can be generated by adding the individual light emission patterns of the phosphor surfaces of the individual substrates located in the illumination surface. A change in the Lichtabstrahlmusters can be achieved by a shift of one or more of these carriers and thus a replacement of at least one phosphor surface in the illumination surface. This embodiment enables in a simple manner a particularly diverse embodiment of the Lichtabstrahlmusters. This allows a Lichtabstrahlmuster produce in a particularly compact manner.

The carriers may in particular be mutually displaceable carriers. The supports may have the same basic shape, e.g. a strip-like basic shape. The carriers may be arranged in a row adjacent to each other, in particular collinear.

The simultaneous illumination of the phosphor surfaces of a plurality of carriers can be implemented, for example, by means of one or more primary light beams. The plural primary light beams may be e.g. be generated by at least one respective light source, alternatively by means of a common light source and subsequent splitting of the primary light beam into a plurality of partial beams.

In general, the light emission pattern may be individualized by simultaneous illumination of several be translatable, in particular linear, movable phosphor surfaces to be generated.

The headlight may in particular be a vehicle headlight. The vehicle may be an aircraft, a waterborne vehicle, or a land vehicle. The land-based vehicle may be a motor vehicle. Particularly preferred is the use of the vehicle headlight in a truck or passenger car. Different positions of the at least one phosphor surface can be used to generate different automobile light emission patterns, e.g. for producing a low beam, a high beam, a fog light, etc. Alternatively or additionally, uniformly shaped light emitting patterns with different light color can be provided, e.g. a bluish daytime running light and a less "blue" position light for nocturnal use.

Particularly preferred is an embodiment of the lighting device as a vehicle headlight or as a part thereof, wherein the vehicle headlight as an AFS ("Adaptive Frontlighting System") - or an ADB ("Adaptive Driving Beam") - headlights is set up. By changing the position of at least one luminous surface, a simple actionable change of the light emission pattern (eg the light color or color distribution) in response to external influences is possible. Such influences may include environmental parameters, such as a weather situation, a condition of a lane, a time of day, a position of the sun, etc., or driver-specific parameters such as age, fatigue, level of experience, and so on. Such parameters can be detected by a corresponding type of sensor of the vehicle, for example, a camera, a rain sensor, a distance sensor, etc. In particular, it is also possible within the framework of an AFS or ADB system to cover certain combinations of parameters in the light distribution automatically (in particular without driver involvement). So not just adjusting the color to, for example, the presence of fog, but also to the combination of fog with an old or a young driver. Also, the peculiarities of color blind or partially color blind (eg, with a red / green weakness) can be considered. This, in turn, can achieve greater traffic safety. It may also be additional comfort for the driver or passengers are generated.

Fig.1

zeigt als Schnittdarstellung in Seitenansicht eine Leuchtvorrichtung gemäß einem ersten Ausführungsbeispiel mit einem linear verschieblichen Träger;

Fig.2

zeigt in Draufsicht einen linear verschieblichen Träger mit mehreren Leuchtstoffflächen;

Fig.3

zeigt als Schnittdarstellung in Seitenansicht eine Leuchtvorrichtung gemäß einem zweiten Ausführungsbeispiel; und

Fig.4

zeigt als Schnittdarstellung in Seitenansicht eine Leuchtvorrichtung gemäß einem dritten Ausführungsbeispiel.

The above-described characteristics, features, and advantages of this invention, as well as the manner in which they will be achieved, will become clearer and more clearly understood in connection with the following schematic description of exemplary embodiments which will be described in detail in conjunction with the drawings. In this case, the same or equivalent elements may be provided with the same reference numerals for clarity.

Fig.1

shows a sectional side view of a lighting device according to a first embodiment with a linearly displaceable carrier;

Fig.2

shows in plan view a linearly displaceable carrier with a plurality of phosphor surfaces;

Figure 3

shows a sectional side view of a lighting device according to a second embodiment; and

Figure 4

shows a sectional side view of a lighting device according to a third embodiment.

Fig.1 shows a lighting device 1, for example, for a vehicle headlight E. The vehicle headlight E may eg be installed in a motor vehicle, for example in a passenger car, a truck or a motorcycle. The vehicle headlight E generates a light emission pattern L in a far field F around the vehicle, in particular in front of the vehicle.

The lighting device 1 has a plate-like or disk-like carrier 2 for three planar phosphor volumes, which are referred to below as fluorescent surfaces 3a to 3c. The phosphor surfaces 3 a, 3 b and 3 c lie next to one another in a row on a flat surface of the carrier 2. The phosphor surfaces 3a to 3c may be e.g. be sprayed or printed on the support 2. Alternatively, the phosphor surfaces 3a to 3c may have been applied to the carrier 2 as respective prefabricated platelets (e.g., ceramic platelets), e.g. be glued on.

The lighting device 1 further comprises a light source in the form of a laser 4, which e.g. blue primary light P emits. The blue primary light P preferably, but not necessarily, has a peak wavelength in the wavelength range from 360 nm to 480 nm, in particular from 400 nm to 460 nm. The laser 4 may e.g. have one or more laser diodes. The primary light P is radiated obliquely onto the carrier 2 through a small window 5 in a dish-shaped reflector 6 and can there generate an illumination surface 7 which corresponds to the light spot. Due to the only small window 5 and the oblique radiation light losses due to re-radiation in the laser 4 are low.

The beam path of the primary light P remains unchanged in time, ie stationary. As a result, a temporally non-changing (static) planar provision of the illumination surface 7 is achieved.

Between the laser 4 and the illumination surface 7, an optic 8 indicated here by a lens is interposed, for example for beam collimation. Also, the primary light P impinging on the illumination surface 7 may be approximately parallelized instead of being focused as indicated. If a focusing beam path is used, it is also possible, for example, not to put the phosphor surfaces 3a to 3c in the focus of the beam of the primary light beam P (ie in particular after the focus or in the divergent beam again to position) to adjust the size of the illumination surface 7 easier to be able to.

It is a development that the laser 4 and the possible existing optics 8 are located in a common housing and together form a unit. It is alternatively possible to guide the primary light P via a glass fiber to the carrier 2 or to its fluorescent surfaces 3a, 3b or 3c.

The carrier 2 can be displaced along its extended plane by a translatory linear movement, here along a displacement direction V. The carrier 2 assumes different positions, in each of which one of the phosphor surfaces 3a, 3b or 3c lies in the illumination surface 7 or the phosphor surfaces 3a to 3c alternately in the illumination surface 7 can be introduced. In still other words, the carrier 2 can be linearly displaced so that in each case one of the phosphor surfaces 3a, 3b or 3c can be illuminated by the primary light beam P. The phosphor areas 3a to 3c are each shown larger than the illumination area 7. However, this is not necessarily necessary, but gives the advantage that free areas of the carrier 2 are not mitbeleuchtet. The illumination surface 7 can be limited by means of a mechanical diaphragm. This can be connected to the carrier 2.

The illumination surface 7 preferably has an extension (eg of a diameter or an edge length) of at least 20 micrometers. Particularly preferred is an extension of the illumination surface 7 of 50 microns to 500 microns. If the goal is not to achieve a high luminance, a maximum extent of up to 1000 μm is preferred. These values apply in particular to illumination or irradiation with a laser 4 in the form of a laser Laser diode and an incident radiation power of 0.25 W to 60 W. For larger laser powers, these expansion values can be used with correspondingly higher achievable luminance. With higher laser powers, however, it is also possible to use larger expansions, for example a doubling of the area defined by the maximum extent when the laser power is doubled, etc.

At the illuminated phosphor surface (shown here as 3b), the blue primary light P is at least partially converted into yellow secondary light S. In the process, a total of blue-yellow or white mixed light as useful light P, S is radiated from the phosphor surface 3b. Depending on the concentration and / or layer thickness of the blue-yellow-converting phosphor, the useful light P, S may have a neutral white, a bluish-white or a yellowish-white color. Preferably, the useful light P, S of each of the phosphor surfaces 3a to 3c is at least partially within an ECE color space (ie not necessarily white, but for example also yellow, red, etc.).

The phosphor surfaces 3a to 3c are formed differently, for example with respect to their shape and / or phosphor composition. A phosphor composition may, for example, be understood as meaning the presence of one or more specific phosphors, their concentration, their layer thickness and / or their areal distribution or variation thereof. The phosphor surfaces 3a to 3c may in particular have a uniform phosphor composition over their surface.

In the case of the reflective arrangement shown, the useful light P, S is radiated from the same side on which the primary light P is also incident. For this purpose, the carrier 2 is reflective on its side facing the phosphor surfaces 3a to 3c. The carrier 2 is preferably specularly reflective or mirroring executed, in particular for all existing wavelengths, so that both the passing through the phosphor surfaces 3 a, 3 b or 3 c and impinging on the carrier 2 primary radiation P as well as in the direction of the carrier 2 radiated secondary radiation S effectively into the phosphor surfaces 3 a, 3 b or 3c can be thrown back and used with it. This increases a conversion efficiency.

The carrier 2 is for effective heat dissipation of the phosphor surfaces 3a, 3b and 3c, preferably made of metal or a sapphire-on-metal layer stack. It is also possible to arrange a dichroic layer between a non-reflecting support 2 and the phosphor surfaces 3a, 3b and 3c which transmits the primary light P but reflects converted secondary light S on the other hand. Thus, a primary light component of the useful light P, S can be reduced. Such an arrangement is particularly advantageous for the transmissive case (primary light must pass while secondary light should be reflected to achieve higher efficiency).

The useful light P, S, which is radiated from the phosphor surface 3 a, 3 b or 3 c, meets a downstream secondary optics, which is shown here by the shell-like reflector 6. The reflector 6 may, for example, have a spherical, paraboloidal or free-form reflection surface, which may possibly be multi-faceted. The position of the illumination surface 7 and thus also the position of the respective illuminable phosphor surface 3a, 3b or 3c correspond here to a focal spot of the reflector 6. From the secondary optics, the useful light P, S is coupled as Lichtabstrahlmuster L in the far field F.

The secondary optics may have further elements (not shown) for beam shaping of the useful light P, S, eg at least one lens, at least one reflector, a shutter or shutter etc. This may for example be done in such a way that the Reflector 6, the useful light P, S steers in a near-field intermediate plane, which may also include a shutter (o. Fig.). The intermediate plane can then be imaged, for example, by a refractive optical system into the far field F.

By the alternating introduction of the differently configured phosphor surfaces 3a to 3c in the illumination surface 7 respectively associated, different Lichtabstrahlmuster L can be generated. The light emission patterns L may differ in terms of their shape, color and / or color distribution.

In this case, a specific Lichtabstrahlmuster L is generated non-sequentially. This means that a Lichtabstrahlmuster L completely with the carrier 2 and thus also the phosphor surfaces 3a to 3c in exactly one position (corresponding to a particular position) of the carrier 2 can be generated. The carrier 2 thus does not need to move two or more of the phosphor surfaces 3a, 3b or 3c in succession through the primary light P to produce a light emission pattern, but a desired light emission pattern L is produced by illuminating exactly one of the phosphor surfaces 3a to 3c.

It is also possible to change the brightness or laser power of the primary light P as the position of the carrier 2 changes. Thereby, the light emission pattern L can be dimmed, e.g. for generating a daytime running light or a position light.

For example, in a first (linear) position of the carrier 2, only the phosphor surface 3a may be illuminated by the primary light P. Thereby, for example, a light emission pattern L having a bluish-white color and having a shape and intensity suitable for use as a daytime running light may be generated.

By a linear displacement of the carrier 2 by a position such that now only the phosphor surface 3b is illuminated by the primary light P, a second Lichtabstrahlmuster L is generated. The second Lichtabstrahlmuster L differs at least with respect to its shape and / or color, and possibly also with respect to its brightness from the first Lichtabstrahlmuster L. To distinguish the color of their Lichtabstrahlmuster L like the phosphor surfaces 3a and 3b, a different concentration or thickness of the Having contained therein phosphor. For example, the second light-emitting pattern L may emit yellow useful light for use with a turn-signal function. For this purpose, for example, a higher proportion of blue-yellow-converting phosphor may be present in the phosphor surface 3a (for example due to a higher concentration and / or layer density).

If the carrier 2 is moved linearly one more position further so that only the phosphor surface 3c is illuminated by the primary light P (ie, only the phosphor surface 3c is in the illumination surface 7), a third light emission pattern L is generated, e.g. for use as a fog light or the like

Additionally or alternatively, at least one phosphor surface may be present, which still generates another light emission pattern L, e.g. for use as a low beam, as a high beam, etc. There may also be at least two light emitting patterns L for the same purpose, e.g. as daytime running lights, which differ only in one light color, e.g. in a different whitish hue, for example to be able to respond to environmental parameters of the vehicle such as rain and / or a driver's condition such as his tiredness, e.g. under an AFS or ADB.

The number of phosphor surfaces is not limited and may be, for example, two, three or even more than three.

The linear movement of the carrier 2 for positioning the fluorescent surfaces 3a to 3c with respect to the illumination surface 7 by means of a motor, in particular a linear motor 10. The linear motor 10 may for example at least one electric motor (in particular stepper motor) or at least one actuator (eg at least one piezoelectric actuator with or without lift reinforcement).

The linear motor 10 is coupled to a control device 11, which drives the linear motor 10. The linear motor 10 and the controller 11 may also be integrated in a single component. The control device 11 is set up to control the linear motor 10 in such a way that a phosphor surface 3a, 3b or 3c provided for a specific light emission pattern L is thereby moved linearly into the illumination surface 7. The control device 11 can receive control commands ST for actuating the linear motor 10, which command the light emission pattern L to be generated. These control commands ST are converted by the control device 11 into drive signals for the linear motor 10, and the drive signals are then made available to the linear motor 10 for specifying its linear movement. The control commands ST may originate, for example, from vehicle electronics (not shown). The control commands ST may be based on operations of a driver of the vehicle, e.g. be based on switching on a particular light function such as a high beam, and / or on an automatic selection by the vehicle. The automatic selection may e.g. based on measured values of at least one sensor of the vehicle. Thus, the light emission pattern L may be changed depending on the brightness, weather conditions (e.g., rain or fog), recognition of an object in front of the vehicle, driver's attention, and so on.

In principle, it is also possible to move the carrier 2 linearly in two plane directions. In particular, in this case, the phosphor surfaces on the carrier. 2 By a movement of the carrier 2 in both planar directions (in the direction V and a direction perpendicular to it in the image plane direction) all the different phosphor surfaces can be approached two-dimensionally distributed, eg matrix-shaped, cross-shaped. By a two-dimensional arrangement more phosphor surfaces can be accommodated compact, as in a one-dimensional (eg strip-shaped) arrangement.

It is also possible to excite the phosphor surfaces 3a, 3b or 3c by a plurality of lasers 4, in particular laser diodes, or to generate the illumination surface 7 by primary light P of a plurality of lasers 4. Their light can pass through the same window 5 in the reflector 6, but alternatively also pass through different windows to the phosphor surface 3a, 3b or 3c.

Instead of the stationary illumination, a scanning illumination may also be used.

Fig.2 shows in frontal view another possible carrier 12, which is used for example in place of the carrier 2 in the lighting device 1. The carrier 12 has four fluorescent surfaces 13a, 13b, 13c and 13d arranged next to one another in a 2x2 matrix pattern. Only one phosphor surface 13a, 13b, 13c or 13d is illuminated in each case. Each individual phosphor surface 13a, 13b, 13c or 13d can consequently produce a complete light emission pattern L. By a linear movement of the carrier 12 in its plane (for example, generated by means of the linear motor 10), it can be moved so that each of the phosphor surfaces 13a, 13b, 13c or 13d can be brought into the illumination surface 7 respectively. The linear movement is indicated by the double-sided arrows.

The individual phosphor surfaces 13a, 13b, 13c or 13d contain different distributions of phosphors. For example, the phosphor surface 13a may be homogeneously coated with a blue-yellow converting phosphor of a first layer thickness to produce and radiate a cold-white light. The phosphor surface 13b may be homogeneously coated with a blue-yellow converting phosphor of a second layer thickness, which is thicker than the first layer thickness. As a result, a yellowish-white light can be generated and emitted. A warmer hue can also be achieved by adding a blue-red converting phosphor. The phosphor surface 13c may be homogeneously coated with a blue-yellow-converting phosphor of a third layer thickness, which is smaller than the first layer thickness. As a result, a bluish-white light can be generated and radiated. The phosphor surface 13d may have a plurality of partial regions each occupied differently homogeneously with a blue-yellow converting phosphor. Thus, two outer regions similar to the phosphor surface 13c may be occupied and a middle region may be occupied similarly to the phosphor surface 13a.

However, it is not necessary to use a (2 x 2) pattern of the single phosphor surface. Thus, any other arbitrary division into a (nxm) pattern is possible, where n and m are integers, at least one of which is greater than one. In addition, a length-to-width ratio or aspect ratio of the individual phosphor surfaces is arbitrary. The individual phosphor surfaces need not be rectangular, but may take other forms. Between the phosphor surfaces, there may also be areas that are free of phosphor. Also, an irregular arrangement of the phosphor surfaces is possible. Likewise, the arrangement of the phosphors within a phosphor surface is not limited. Any desired division can be used. Realizations are possible both in a transmissive use (transmitted light arrangement as shown) and in a reflective use of the phosphor.

The downstream secondary optic, as described, may be a reflector cup, e.g. but also be a far-field imaging refractive optics. This refractive optics may be particularly advantageous for the transmitted light arrangement.

The carrier 12 may be used for a reflective construction e.g. a metallic support, for a transmissive construction e.g. a glass or sapphire carrier.

Figure 3 shows a lighting device 21, for example, for a vehicle headlight E, which is similar to the lighting device 1 is constructed. However, there are now two reflectors 6a and 6b or corresponding reflection regions of a reflector 6a, 6b. In addition, phosphor surfaces 3a and 3d, 3b and 3e or 3f and 3c arranged on opposite surfaces or flat sides of the carrier 2 can now be irradiated simultaneously, namely by different lasers 4a and 4b. In other words, a first illumination surface 7a on a first flat side of the carrier 2 and a second illumination surface 7b on a second flat side of the carrier 2 can be provided.

The reflectors 6a and 6b in turn are illuminated by the phosphor surfaces 3a, 3b or 3c or 3d, 3e or 3f. A light emission pattern L in the far field F (not shown) can then be composed by a superimposition of the useful light emitted by both reflectors 6a and 6b (not shown). This corresponds to an addition of the useful light generated by opposing phosphor surfaces 3a and 3d, 3b and 3e or 3f and 3c.

In this case, for a particular Lichtabstrahlmuster not both lasers 6a, 6b to be in operation. For example, a high beam may be generated by operation of both lasers 6a, 6b, but a low beam, for example, by operation of only one of the lasers 6a or 6b. Consequently, by selectively activating the lasers 6a or 6b in a same position of the carrier 2, different light emission patterns can be provided become. By linear displacement of the carrier 2 in a different position further Lichtabstrahlmuster can be generated, by common and / or respective activation of the laser 4a and 4b.

A light color and / or shape of the light emission patterns emitted by the two reflectors 6a and 6b may be the same or different. Also, a light color of the primary light P emitted from the two lasers 6a, 6b may be the same or different.

Figure 4 shows a lighting device 31, for example, for a vehicle headlamp E, in which now several (here four vertically aligned) strip-like carrier 2a, 2b, 2c and 2d, each with in a row juxtaposed phosphor surfaces A1 to A3, B1 to B3, C1 to C3 or D1 to D3 are present. The carriers 2a, 2b, 2c and 2d are displaceable parallel to one another along their longitudinal axes, as indicated by the double arrows. The carriers 2a to 2d are immediately adjacent to each other (ie here: separated only by a practically negligible narrow gap) arranged.

Instead of as in the lighting device 1 located in a lighting surface 32 phosphor surfaces A2 to D2 at a time (stationary) over a large area with the primary light P to irradiate and use these phosphor surfaces A1 to D3 as quasi-light source for a downstream optics, in the Illuminating surface 32 located fluorescent surfaces A2 to D2 now over time of a concentrated primary light beam P ("dynamic") over or "scanned". For "scanning", in particular line-like, illumination of the illumination surface 32, the primary light P may be deflectable, in particular via at least one movable, in particular pivotable, mirror 33 onto the illumination surface 32, eg similar to a "flying spot" method. The pivotable mirror 33 may be a MEMS component, for example. The laser 4 may be targeted be switched off (or dimmable). The light emission pattern generated in this way may be varied by a change in the illumination pattern in the case of a fixed position or rotational position of the carriers 2a, 2b, 2c and 2d.

The illuminating surface 32, which can be illuminated line by line by the laser 4, comprises a row of phosphor surfaces A1 to A3, B1 to B3, C1 to C3 or D1 to D3, which are arranged next to one another in relation to their direction of displacement. a row comprising the phosphor areas A2, B2, C2 and D2. It is therefore one fluorescent surface of a strip-shaped carrier 2a to 2d illuminated simultaneously. Since the carriers 2a to 2d are linearly displaceable independently of one another, all possible adjacent phosphor surfaces A1 to A3, B1 to B3, C1 to C3 or D1 to D3 can be combined.

The phosphor surfaces A1 to A3, B1 to B3, C1 to C3 or D1 to D3 of a respective strip-shaped carrier 2a to 2d may in particular have a different phosphor composition (eg with respect to a type, amount and / or areal distribution of phosphor) and thereby produce a differently shaped and / or differently colored part of the entire Lichtabstrahlmusters.

A specific Lichtabstrahlstrahlmuster can be adjusted for example by any, but then firmly selected combination of the phosphor surfaces A1 to A3, B1 to B3, C1 to C3 and D1 to D3. The light generated in this process can again be thrown into the far field F by means of optics (not shown), in particular an imaging optic.

For the linear movement of the carriers 2a, 2b, 2c and 2d, respective linear motors 10a to 10d may be used, which are controllable together by the control device 11. The control device 11 can also receive control commands ST for controlling the linear motors 10a to 10d, which predetermine the light emission pattern L to be generated. These Control commands ST are converted by the control device 11 into drive signals for the linear motors 10a to 10d in order to bring the combination of the phosphor areas A1 to D3, corresponding to the desired light emission pattern, into the illumination area 32.

Alternatively, instead of the scanning illumination, a stationary illumination of the phosphor areas A2 to D2 located in the illumination area 32 may be performed, e.g. through a correspondingly wide, stationary beam of primary light P.

Basically, the number of independently mobile carriers is not limited and may include hundreds or even thousands of independently mobile carriers.

Also, the illuminable area 32 may include multiple lines.

The lighting device 31 may be implemented in a reflective arrangement or in a transmissive arrangement.

Although the invention has been further illustrated and described in detail by the illustrated embodiments, the invention is not so limited and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention.

Thus, in principle, it is possible to choose between a stationary and a scanning irradiation of a fluorescent surface.

Also, instead of or in addition to a linear translational movement, at least one phosphor surface displaced on a curved trajectory or trajectory may be used.

In addition, the translational movement may be superimposed by a rotational movement of the at least one phosphor surface, in particular in order to achieve a pivoting of the phosphor surface.

Generally, "on", "an", etc. may be taken to mean a singular or a plurality, in particular in the sense of "at least one" or "one or more" etc., unless this is explicitly excluded, e.g. by the expression "exactly one", etc.

Also, a number may include exactly the specified number as well as a usual tolerance range, as long as this is not explicitly excluded.

reference numeral

1

Lighting device for a vehicle headlight

2

carrier

3a-f

Fluorescent surfaces

4

laser

4a

laser

4b

laser

5

hole

6

reflector

6a

reflector

6b

reflector

7

illumination area

8th

optics

10

linear motor

11

control device

12

carrier

13a-d

Fluorescent surfaces

21

lighting device

31

lighting device

32

illumination area

33

movable mirror

A1-A3

Fluorescent surface

B1-B3

Fluorescent surface

C1-C3

Fluorescent surface

D1-D3

Fluorescent surface

e

vehicle headlights

F

far field

L

Lichtabstrahlmuster

P

primary light

S

secondary light

Claims (10)

1. Lighting apparatus (1; 21; 31) for a headlight (E) for generating a light emission pattern (L) in a far field (F), comprising

   - at least one light source (4; 4a, 4b) for emitting primary light (P) onto an illumination surface (7; 7a, 7b; 32);

   - at least two different phosphor surfaces (3a-3c; 3a-3f; 13a-13d; A1-D3) which are introducible into the illumination surface (7; 7a, 7b; 32); at least partly alternately by means of at least one translational movement (V); and

   - a control device (11) for positioning the phosphor surfaces (3a-3c; 3a-3f; 13a-13d; A1-D3) in relation to the illumination surface (7; 7a, 7b; 32);

   wherein

   - a respectively associated light emission pattern (L) is generatable in a predetermined position of the phosphor surfaces (3a-3c; 3a-3f; 13a-13d; A1-D3); and

   - the control device (11) is configured, for the purpose of setting a specific light emission pattern (L), to move at least one phosphor surface (3a-3c; 3a-3f; 13a-13d; A1-D3) provided for this purpose into the illumination surface (7; 7a, 7b; 32) by means of at least one translational movement,

   characterized in that the lighting apparatus comprises a plurality of carriers (2a-2d) which are at least translationally displaceable independently of one another and each have a plurality of phosphor surfaces (A1-D3), wherein a phosphor surface (A1-D3) of a respective carrier (2a-2d) is in each case introducible simultaneously into the illumination surface (32).
2. Lighting apparatus (1; 21; 31) according to Claim 1, wherein the phosphor surface (3a-3c; 3a-3f; 13a-13d; A1-D3) is movable into the illumination surface (7; 7a, 7b; 32) by means of a pure translational movement.
3. Lighting apparatus (1; 21; 31) according to Claim 1, wherein the phosphor surface (3a-3c; 3a-3f; 13a-13d; A1-D3) is movable into the illumination surface (7; 7a, 7b; 32) by means of a translational movement and additionally a rotational movement.
4. Lighting apparatus (1; 21; 31) according to any of the preceding claims, wherein the light emission patterns (L) have a different shape, a different light color and/or a different color distribution.
5. Lighting apparatus (1; 21; 31) according to Claim 3, wherein at least two light emission patterns (L) have a differently white light color.
6. Lighting apparatus (1; 21) according to any of the preceding claims, wherein a light emission pattern (L) is generatable by means of at least one primary light beam (P) aligned in a stationary fashion.
7. Lighting apparatus (1; 21) according to any of the preceding claims, wherein the light emission pattern (L) is generatable by means of a movement of at least one primary light beam (P).
8. Lighting apparatus (1; 21; 31) according to any of the preceding claims, wherein at least one phosphor surface (3a-3c; 3a-3f; 13a-13c; A1-D3) has a uniform distribution of phosphor.
9. Lighting apparatus (1; 21; 31) according to any of the preceding claims, wherein at least one phosphor surface (3a-3c; 3a-3f; 13d; A1-D3) has a nonuniform distribution of at least one phosphor.
10. Lighting apparatus (1; 21; 31) according to Claim 9, wherein at least one phosphor surface (3a-3c; 3a-3f; 13a-13d; A1-D3) comprises a plurality of phosphors which are distributed over the phosphor surface (3a-3c; 3a-3f; 13a-13d; A1-D3) nonuniformly with respect to one another.

Images