DE102016213428B4 - Lighting device and method for generating a light distribution in an environment by means of a light source and a converter element - Google Patents

Abstract

Lighting device (1) for generating a predetermined light distribution (9) in an environment (8) of the lighting device (1), comprising: - a light source (2) for generating a light beam (3) from excitation light (3 '), - a converter element ( 4) for generating a converter light (6) when excited by the excitation light (3 '), - an optical device (7) for aligning the converter light (6) in the environment (8), and - an adjusting device (11) for setting a predetermined first position pattern (14 '), which provides a sequence of several relative positions of the light beam (3) with respect to the converter element (4), so that by the first position pattern (14') in total on the converter element (4) by a light spot (5 ) of the excitation light (3 ') is determined, from which the predetermined light distribution (9) results when aligned by the optical device (7), wherein the lighting device (1) for generating the predetermined light distribution (9) is designed to be redundant by at least one second position pattern (17 ') is provided by the adjusting device (11) through which a second light path (17) different from the first light track (14) is defined, from which when aligned by the optical device (7) also the predetermined light distribution (9) or a light distribution which satisfies a predetermined similarity criterion with respect to the predetermined light distribution (9), wherein a sequence of cyclically repeated positions is defined by the first position pattern (14 ') and the at least one second position pattern (17 ') provides the sequence offset by a predetermined spatial offset (18), wherein the adjusting device (11) is adapted to switch at least temporarily between a plurality of discrete position patterns (14', 17 '), wherein a Switching device (20) is adapted to check a predetermined switching condition (23) n and when the switching condition (23) is satisfied, to generate a switching signal, and wherein the adjusting device (11) is set up to change between the first position pattern (14 ') and the at least one second position pattern (17') as a function of the switching signal, wherein the switching means (20) comprises a sensor element (21) for detecting contamination of the converter element (4) and / or a spectral distribution (22) of the converter light (6), and the switching condition (23) includes that the contamination is a predetermined fouling criterion and or the spectral distribution (22) satisfies a predetermined distribution criterion (22 ').

Description

The invention relates to a lighting device for generating a predetermined light distribution in an environment of the lighting device. The lighting device may be configured, for example, as a motor vehicle headlight. The light distribution is generated with a light generated by a converter element. The invention also includes a method for generating the light distribution in the environment on the basis of the light source and the converter element.

In the lighting device according to the invention, white light may e.g. be generated by a blue-emitting LED (light emitting diode) or by means of a laser source as a light source, wherein the converter element, e.g. based on a phosphor, e.g. Phosphorus, broadband produces a yellow portion. It is possible to install the phosphor externally, either as a transmitted light version or reflexively, the second has the advantage of being able to better dissipate the heat via a massive metallic reflector (currently 20 W electrical power are common).

Laser light sources can cause the so-called dark spot syndrome: After only a few hundred hours of operation, a black spot appears in or on the phosphor, which massively suffers the light output. This stain is created mainly by attracting dirt particles through the laser beam and accelerating through the same in the direction of the phosphor where they burn. At this dark spot, the temperature also rises rapidly, while the light output suffers.

A second difficulty is to dissipate the resulting waste heat. If it is not possible to cool sufficiently, on the one hand the yellowing of the glue of the phosphor threatens, whereby also a dark spot develops. On the other hand, a so-called rollover threatens: If the phosphor is too hot, its efficiency decreases such that it can no longer give off converted (yellow) light because it is pumped excessively.

From the DE 10 2012 213 036 A1 For example, a lighting device with a phosphor wheel is known. This device is also based on the generation of converter light by excitation by means of a laser, which is also referred to as LARP (Laser Activated Separate Phosphorus). In this case, the converter element can be a rotating phosphor wheel in order to distribute the laser beam power of the laser radiation occurring on average over a larger area and thus to reduce the phosphor degradation. At any given time, a light spot is formed on the converter element at the point of impact of the laser beam, which describes an annular or circular path on the converter element over time due to the rotation of the converter element. This trace of the luminous spot is referred to below as a light trail.

The generation of a light trail can also be used to set or adjust the light distribution in the environment. This is from the DE 10 2012 208 566 A1 the so-called vector-based scanning of a converter element by means of a laser known. The laser is designed here as a vector scanner and moves the light spot on the converter element along a scan path, whereby the tracer is formed. The scan path is described by vector data. An alternative to vector-based sampling is line-by-line rasterizing, for which a line scanner is provided to move the laser beam.

From the CN 102 809 881 A For example, a light source system and an associated projection system are known. The light source system includes a light source that emits exciting light, a moving device provided with a wavelength conversion optical material, and an adjusting device. The excitation light irradiates the optical wavelength conversion material. When the moving device is in a periodically moved state, the light spot position irradiated by the exciting light on the moving device moves on a first working track. The adjusting device serves to set the light spot position, so that the light spot position irradiated by the set excitation light on the moving device moves on a second working track. The first working track is separated from the second working track.

WO 2014/121 314 A1 discloses a headlight for motor vehicles with at least one modulatable laser light source whose laser beam is directed to a light conversion means via a pivotable micromirror controlled by a mirror drive and to a projection system for projecting the light image generated at the light conversion means onto the light Roadway in which at least two laser light sources are provided, which is associated with a laser driver for modulating the beam intensity, between each laser light source and the micromirror is arranged an optical system for forming a laser beam with a predetermined beam cross-section, the micromirror oscillates at an fixed frequency about an axis the shaped beams of the at least two laser light sources are deflected over the micromirrors to form at least two contiguous horizontal bands of light on the luminous area.

From the DE 10 2013 226 652 A1 A method is known for operating a lighting apparatus with n> 1 light generating means for generating a respective primary light beam and a phosphor surface spaced from the light generating means, the method comprising: illuminating an ith partial surface of the phosphor surface with i light generating means if a desired positive brightness value thereon illuminated sub-area falls below or reaches a next higher i-th brightness threshold from a group of n-1 positive, successively increasing brightness thresholds, otherwise illuminate with n light generating device, where i and n are integer natural numbers and i = [1,. .., n] applies.

The invention has for its object to efficiently generate converter light from the excitation light of a light source in a lighting device by means of a converter element.

The object is solved by the subject matters of the independent claims. Advantageous developments of the invention are disclosed by the features of the dependent claims, the following description and the figures.

The invention provides a lighting device for generating a predetermined light distribution in an environment of the lighting device. The light distribution describes a function of the light intensity as a function of the emission direction. The light distribution can represent, for example, a dipped-beam light distribution or a high-beam light distribution for a motor vehicle headlight. To generate the light distribution, a light source for generating a light beam of excitation light, a converter element for generating a converter light when excited by the excitation light and an optical device for aligning the converter light are provided in the environment. The generation of the converter light may be based on luminescence, e.g. on phosphorescence or fluorescence. In this case, in order not to depend on a single spot on the converter element, but e.g. to perform the vector-based or line-raster-based scanning, the converter element and the light beam are moved relative to each other. For this purpose, an adjusting device for setting a predetermined first position pattern is provided. This first position pattern thus provides a sequence of several relative positions of the light beam with respect to the converter element. Thus, for example, the first position pattern can specify the sum of the positions for the vector-based scanning or the line-by-line scanning or rastering. As a result of the first position pattern, a total of the first luminous trace caused by the luminous spot of the excitation light is produced on the converter element. The first position pattern thus defines this first tracer path. The first tracer does not have to be visible or permanently present in its entire length. However, the entire first tracer track is typically traversed or traversed so fast that for a person the light distribution is at least substantially constant or non-flickering. In other words, the first tracer is preferably traversed or traversed in less than 100 milliseconds, in particular less than 50 milliseconds. From the entire first tracer track, the predetermined light distribution in the surroundings results from the alignment effected by the optical device.

If only the same tracer is traversed or traversed during each operation of the lighting device, the described wear effect may result, i. along the tracer track, the converter element is worn or darkened or yellowed.

In order to avoid this, or at least delay it in time, so that a total number of operating hours of the lighting device and in particular of the converter element can be increased, it is provided that the lighting device is designed to be redundant for generating the predetermined light distribution. For this purpose, by the adjusting device at least one further position pattern, i. at least a second position pattern provided. By each further, second position pattern is a different light trail from the first light trail, i. a second tracer track, different from the first tracer track, but from which, in effect, the orientation of the optical device causes the predetermined distribution of light in the surroundings. By means of a further position pattern, therefore, the luminous spot of the excitation light is guided on the converter element along another track or tracer track. In this case, however, it is furthermore ensured that the intended light distribution, that is to say the orientation of the optical unit, is determined by the resulting converter light which emanates from the further, second luminous trace. the predetermined light distribution, or a light distribution that satisfies a predetermined similarity criterion with respect to the predetermined light distribution results.

In the case of the phosphor wheel described at the outset, therefore, a tracer track represents, for example, the described circular trajectory on the converter element. A further tracer track can then be a further trajectory but has a different radius or is offset axially. In this case, however, the converter element and the light beam are adjusted in such a way that, for example, by the adjusting device, that of the other Tracer light outgoing light again the predetermined light distribution or a light distribution that meets a predetermined similarity criterion with respect to the predetermined light distribution results. The similarity criterion may, for example, state that the two light distributions (of which one results before and one after the change) should be congruent with respect to the local brightness distribution to at least 90 percent, in particular at least 95 percent. Another similarity criterion may state that at each point of the local brightness distribution the relative difference should be less than 20 percent, in particular less than 10 percent.

A single trace of light is thus the quantity of points on the converter element to be illuminated to completely generate the light distribution. The tracer track can be traversed cyclically repeatedly to thereby continuously provide the light distribution. A different further tracer track is then another set of points to be illuminated on the converter element with the same effect. Each trace of light can be used permanently as an alternative to another trace of light in order to provide the predetermined light distribution, without causing a temporal interruption of the generation of the predetermined light distribution. Thus, a tracer is not a single trajectory of a total trajectory, e.g. in vector-based sampling or line-based sampling to produce the complete light distribution.

This results in the advantage that after a wear of a tracer track can be switched to a further tracer track or changed by the further, second position pattern is activated, and then the converter element can be further used in an unworn area. It can also be switched on a preventive basis regularly between different position patterns in order to slow down the wear of each tracer track and / or locally lower a temperature.

In the described vector-based sampling, the first position pattern is a sequence of cyclically repeated positions. In order to provide a further second position pattern that is redundant for this purpose, it is provided that the sequence of the positions of the position pattern is offset by a predetermined spatial offset. Thus, the tracer tracks of two position patterns have the same shape, but are shifted or offset by the spatial offset. This has the advantage that no costly conversion of the speed profile and / or the motion profile of the scanner is necessary. It can e.g. the converter element are shifted by the offset.

The invention also includes optional developments, by the characteristics of which additional benefits.

If the first position pattern is a line pattern of parallel lines, that is to say, for example, a line-by-line scan or column-by-scan, it is preferably provided that at least one further, second position pattern is provided by providing an identical line pattern to this line pattern which is less than shifted as a line spacing. Thus, for example, in a line-by-line scan or rasterization, it may be provided that the first pose pattern is the odd line, i. every other line starting with line 1, comprises and another, second position pattern, the even lines, so also every second line starting with line 2, so offset by one line, provides. Each line pattern has a line spacing of two lines of the overall line pattern and the offset is then one line.

In order to avoid that a luminous trace is heated too much, provides a development that the adjusting device is adapted to superimpose a stepless or continuous relative movement of the light beam and the converter element, starting from the first position pattern, the continuous relative movement preferably transverse to a longitudinal extent of the tracer path runs. As a result, then arise with each movement more position patterns. In other words, the tracer track of the first position pattern is continuously shifted on the converter element. A straight line section of the tracer track is thereby preferably transversely to the line course, that is, perpendicular to it or moved laterally. This results in a continuous change of the acted upon by the excitation light points of the converter element. The movement can be permanent or temporary.

Additionally or alternatively, it is provided that the setting device is set up to step incrementally between a plurality of discrete position patterns, e.g. switch according to a round robin method. By discrete positional patterns is meant that the total number of attitude patterns is finite, unlike the described continuous relative motion. It is thus possible to switch between 2 or 3 or 4 or more than 4 different position patterns step by step. The round-robin method may, for example, provide the sequence 1, 2, 3, 4, 1, 2,.

A merely on-demand switching can be realized by providing a switching means which is arranged to check a predetermined switching condition and to generate a switching signal when the switching condition is satisfied. In this case, the adjusting device is set up to change between the position patterns, ie between the first position pattern and the at least one second position pattern, as a function of the switching signal. For example, the switching condition may indicate that a position pattern should be used for a predetermined period of time, for example, 2 minutes or 10 minutes, and then the switching condition is satisfied, ie, the next position pattern is changed.

According to the switching signal is generated depending on the wear. For this purpose, the switching device has a sensor element for detecting contamination of the converter element and / or a spectral distribution of the converter light. The switching condition includes the fact that the contamination meets a predetermined contamination criterion and / or the spectral distribution of the converter light a predetermined distribution criterion. The contamination criterion and the distribution criterion are in each case adapted in each case to the sensor element. The contamination criterion may, for example, define a shadow formation and / or contrast surfaces or contrast edges in a signal of the sensor element. For this purpose, the sensor element can have, for example, a camera. The distribution criterion may, for example, specify a proportion or an amount of a predetermined light frequency and / or a ratio of at least two predetermined light frequencies. For example, Thus, a ratio for a blue / yellow component or a blue / yellow distribution can be predetermined. If this distribution is not adhered to, the distribution criterion is violated, for example, a yellow component too low and / or a blue component too high.

In order to adjust said relative position between light beam on the one hand and converter element on the other hand, the adjusting device is designed accordingly. It can thus be provided that the setting device is set up to move the converter element in order to change the relative position. Alternatively, it can be provided that the adjusting device moves the light beam. Another alternative provides for movement of both the converter element and the light beam. To move, for example, in individual movement steps, a magnetic coil and a ratchet can be provided. A continuous movement can e.g. be effected by means of an ultrasonic motor or an electric motor. The actuator may also include a mirror or DLP (Digital Light Processing) element or a photonic crystal to direct or redirect the light beam relative to the converter element or to adjust its emission direction. In other words, the laser scanner described may be provided as the light source, the deflection device is then part of the adjusting device.

It is particularly advantageous if the optical device is configured to image the first tracer track and / or the second tracer track out of focus in the environment by capturing or imaging the respective tracer track outside a focal point of the optical device. By means of this deliberately set blurring, a change in the light distribution can be avoided if shifting or changing the luminous trace would result in a sharp change in the light distribution. An additional alternative possibility for correcting a change in the light distribution results from the fact that the optics device is set up to change an optical path for the converter light when changing between at least two position patterns and thereby completely or completely changes the light distribution caused by the change to the new position pattern partially compensate. In other words, the optical device is readjusted to counteract the change in the light distribution. For example, a lens and / or a mirror of the optical device can be moved or changed over.

As already stated, the lighting device according to the invention is particularly advantageous in connection with the provision of a motor vehicle headlight, i. the lighting device is preferably designed as a motor vehicle headlight.

The operation of the lighting device according to the invention results in the following inventive method. A light source generates a light beam of excitation light, and a converter element generates the converter light upon excitation by the excitation light, for example by fluorescence. The optical device aligns the converter light in the environment. The adjusting device sets a predetermined first position pattern, which provides a sequence of several relative positions of the light beam with respect to the converter element. Due to the first position pattern, that is, by the set of all positions of the sequence and thus the amount of all positions of the light spot on the converter element, the total result on the converter element by the light spot a first tracer, from which results in alignment by the optical device, the predetermined light distribution , With orientation here is the optical Imaging the first trace of light into the environment meant.

The lighting device is designed to be redundant, in that at least one further position pattern, that is, by the adjusting device, is used. at least one second attitude pattern is provided by which a further tracer track other than the first tracer track, i. a second light tracing different from the first tracer is defined, from which when aligned by the optical device also the predetermined light distribution or a light distribution that satisfies a predetermined similarity criterion with respect to the predetermined light distribution results, wherein by the first position pattern a sequence of cyclically repeated Positions is defined and the at least one second position pattern offset the sequence by a predetermined spatial offset, wherein the adjusting device is adapted to switch at least temporarily between a plurality of discrete position patterns stepwise, wherein a switching means is adapted to check a predetermined switching condition and when satisfied Switching condition to produce a switching signal, and wherein the adjusting device is adapted to, in response to the switching signal between the first position pattern and the at least e change in second position pattern, wherein the switching means comprises a sensor element for detecting contamination of the converter element and / or a spectral distribution of the converter light and includes the switching condition that the pollution meets a predetermined pollution criterion and / or the spectral distribution a predetermined distribution criterion.

The invention also includes developments of the method according to the invention, which have features as they have already been described in connection with the developments of the lighting device according to the invention. For this reason, the corresponding developments of the method according to the invention are not described again here.

• 1 eine schematische Darstellung einer Ausführungsform der erfindungsgemäßen Leuchtvorrichtung;
• 2 eine schematische Darstellung einer weiteren Ausführungsform der erfindungsgemäßen Leuchtvorrichtung.

In the following an embodiment of the invention is described. This shows:

• 1 a schematic representation of an embodiment of the lighting device according to the invention;
• 2 a schematic representation of another embodiment of the lighting device according to the invention.

The exemplary embodiment explained below is a preferred embodiment of the invention. In the exemplary embodiment, the described components of the embodiment each represent individual features of the invention that are to be considered independently of one another, which also each independently further develop the invention and thus also individually or in a different combination than the one shown as part of the invention. Furthermore, the described embodiment can also be supplemented by further features of the invention already described.

In the figures, functionally identical elements are each provided with the same reference numerals.

1 shows a lighting device 1 , which may be configured for example as a motor vehicle headlight. The lighting device 1 has a light source 2 which may be, for example, a laser light source or a light source with one or more light-emitting diodes. The light source 2 can a ray of light 3 from excitation light 3. ' generate on a converter element 4 is directed where the excitation light 3. ' a light spot 5 causes. The converter element 4 can for example be realized on the basis of a phosphor, eg phosphorus.

In the spot of light 5 is due to the excitation by the excitation light 3. ' of the light beam 3 a converter light 6 whose spectral distribution differs from a spectral distribution of the excitation light 3. ' different. For example, the excitation light 3. ' be predominantly blue light while the converter light 6 white light is.

The converter light 6 can by an optical device 7 in an environment 8th the lighting device 1 be guided or directed or aligned. In the neighborhood 8th the converter light 6 forms a light distribution 9 , by the spatial distribution or arrangement, for example, a dipped beam or a high beam for a motor vehicle can be generated. By mapping the light spot 5 about the optics 7 towards the light distribution 9 but only results in a subarea 10 the entire light distribution 9 ,

An adjusting device 11 Therefore, a relative change in position of the light beam 3 effect with respect to the converter element 4. For example, by the adjusting device 11 a pivoting movement 12 of the light beam 3 be effected so that the light spot 5 a path of movement over time 13 on the converter element 4 performs. The entire trajectory 13 thus results in a (first) tracer path 14 from the different positions of the light spot 5 on the converter element 4 , The for creating the light trail 14 required totality of the relative positions of the light beam 3 with respect to the converter element 4 Total results (first) position pattern 14 ' that in the 1 through the first trace of light 14 even graphically represented. The light trail 14 puts in the in 1 shown example, a line pattern in the form of a line grid Z. The optical image of the tracer 14 through the optical device 7 results in the entire light distribution 9 , The light trail 14 thus represents the result of the amount or sum of all relative positions of the light beam 3 with respect to the converter element 4 through which overall the light distribution 9 results. The position pattern 14 ' can be cycled through, for example, with a cycle frequency of more than 20 Hz, in particular more than 50 Hz.

The adjusting device 11 may in the manner described, for example by means of a mirror, a DLP element or a crystal, the light beam 3 according to the pivoting movement 12 move. Additionally or alternatively, a mechanical moving part 15 for moving the converter element 4 be provided. For example, for the illustrated line by line scanning of the converter element 4 through the light beam 3 a gradual feed 16 be effected.

During operation of the lighting device 1 wears the converter element 4 in those places where the light spot 5 incident. In other words, after some time of operation, the converter element 4 along the trail of light 14 Wear and tear, such as yellowing and / or darkening.

To the converter element 4 To wear evenly or to fully exploit its excitable volume is at the lighting device 1 provided, for generating the light distribution 9 not only the first position pattern 14 ' for generating the first light trail 14 but redundantly or independently of this, another (second) tracer 17 to generate, which from another (second) position pattern 17 ' from relative positions of the light beam 3 with respect to the converter element 4 results. In 1 is shown as the position pattern 14 'by a spatial offset 18 can be moved. For example, by means of the mechanical positioning unit 15 a feed 16 be effected. Additionally or alternatively, also the pivoting movement 12 of the light beam 3 be converted accordingly.

Switching between the first position pattern 14 ' and the second position pattern 17 ' can be automated by a changeover device 20 be performed. The changeover device 20 For example, this may include a processor device, such as a microcontroller or a microprocessor, and / or, for example, an integrated circuit. It can be a sensor element 21 be provided, which in the beam path of the converter light 6 can be arranged and a spectral distribution 22 of the converter light 6 can capture. The changeover device 20 can the spectral distribution 22 with a desired distribution 22 'and thereby check whether a predetermined distribution criterion 23 is injured, for example, a yellow part of the spectral distribution 22 is less than a predetermined threshold. The changeover device 20 can then control the actuating device in this case, to move from the position pattern 14 ' on the position pattern 17 ' switch. As the sensor element 21 a sensor device can be used, which can be present anyway, because a blue laser steel is dangerous. As soon as it hits the phosphor, white mixed light is created with rays of light whose directions correspond to a hemisphere. It is no longer a bundled beam. However, if the phosphor breaks, the blue laser beam may leak. One wants to recognize and switch off this situation. Preferably, two sensors are used, one with a yellow color filter and one with a blue color filter. Possibly even a third without filter to control the total amount of light (and the two sensors, since the sum of the values (proportional) must be equal to the filterless sensor).

If changing by the position patterns 14 ' and 17 ' an undesirably large change in the light distribution 9 results, it can be provided with the change and a position and / or configuration of the optical device 7 to compensate for the change in whole or in part.

At the in 1 shown arrangement of light source 2 , Converter element 4 and optics 7 it is a so-called transmitted light, in which the light entry of the excitation light 3. ' on the one hand and the light emission of the converter light 6 on the other hand on different sides of the converter element 4 located.

In 2 is an alternative embodiment of the lighting device 1 shown. By means of a mirror 24 , For example, a metallic reflector, a reflective or reflective embodiment is provided, wherein the excitation light 3. ' on the same side of the converter element 4 enters this, at which also the converter light 6 exit. Also in this embodiment is a change between position patterns in the manner shown 14 ' and 17 ' for example, if it fulfills a distribution criterion 23 possible.

In the following, further possible embodiments of the invention are described:

In order to distribute the load of the phosphor of a converter element, it is moved relative to the laser beam. This can be done either slowly and (optionally) step by step - eg by solenoid and ratchet. This has the advantage of a very simple, inexpensive mechanism (solenoid, spring, ratchet, feed once possible).

If the blue / yellow distribution is monitored, the feed can be made at least once if the ratio is no longer correct.

A faster relative movement can e.g. be effected by means of ultrasonic motor with the aim to obtain a uniform aging over the entire area used.

The phosphor can also be arranged on a rotating disk, which is good for heat dissipation and the mechanism will stabilize itself like a gyroscope.

Particularly preferred is the application of the same idea when the laser light beam sweeps over the phosphor - for example, to build a light distribution line by line or implement for vector-based scanning. In this case the odd and even lines can be used alternately, as in 1 and 2 is illustrated. The phosphor may also be arranged on a drum instead of on the illustrated disc or plate. The drum can also rotate continuously.

By appropriate deliberate blurring in the optical device 7 is still generated in even and odd lines in about the same photograph. A blurred image is also advantageous because you want to achieve a uniform distribution of light, so a fusion of the lines.

Subsequently, one can use N lines in turn (as long as the light distribution is still similar enough and the resolution remains sufficient).

It is also possible to detect contamination - e.g. with sensors for the yellow and blue light components for the detection of fluorescent failure - and only then to change to the next line.

For the realization of the invention, the laser beam (eg by means of a mirror) or the phosphor can be moved. For the realization of the invention, the laser beam can pass through the phosphor ( 1 ) or there is a mirror behind the phosphor ( 2 ). The mirror is preferably made of solid metal and thus the dissipation of heat useful. For the invention, it does not matter in which form the laser beam is guided or moved. The beam could also be split, for example, by a photonic crystal and thus be divided into, for example, several beams or already define a part or even the entire light distribution. The beam split into partial beams by a photonic crystal can also be moved again in order to generate a part of the total light distribution with each partial beam. Such a crystal is particularly interesting when it divides the beam into sub-beams, which hit the center of mirrors of a DLP. The phosphor can then (in the further beam path) in a main reflector (or between DLP and main reflector) sit. You can also move a main reflector.

The main reflector reflects the converted light into the environment.

Overall, therefore, the example shows how can be achieved by the invention, an extension of the lifetime of phosphor for laser light.

LIST OF REFERENCE NUMBERS

1

lighting device

2

light source

3

beam of light

3 '

excitation light

4

converter element

5

spot

6

converter light

7

optical device

8th

Surroundings

9

light distribution

10

subregion

11

setting device

12

pivotal movement

13

trajectory

14

tracer

14 '

position pattern

15

traversing

16

feed

17

tracer

17 '

position pattern

18

offset

19

line spacing

20

changeover

21

sensor element

22

Target distribution

22

distribution

23

distribution criterion

24

mirror

Claims (11)

Lighting device (1) for generating a predetermined light distribution (9) in an environment (8) of the lighting device (1), comprising: a light source (2) for generating a light beam (3) from excitation light (3 '), a converter element (4) for generating a converter light (6) upon excitation by the excitation light (3 '), - An optical device (7) for aligning the converter light (6) in the environment (8), and - An adjusting device (11) for setting a predetermined first position pattern (14 '), which provides a sequence of several relative positions of the light beam (3) with respect to the converter element (4), so that by the first position pattern (14') in total on the converter element (4) a first tracer track (14) caused by a light spot (5) of the excitation light (3 ') is defined, from which the predetermined light distribution (9) results when being aligned by the optical device (7), the lighting device (1) for generating the predetermined light distribution (9) is configured redundant by at least one second position pattern (17 ') is provided by the adjusting device (11) through which a second light path (17) different from the first light track (14) is defined when aligned by the optical device (7) also the predetermined light distribution (9) or a light distribution with respect to the predetermined Lichtverteilunun g (9) satisfies a predetermined similarity criterion, wherein a sequence of cyclically repeated positions is defined by the first position pattern (14 ') and the at least one second position pattern (17') provides the sequence offset by a predetermined spatial offset (18) in which the setting device (11) is set up to switch over at least temporarily between a plurality of discrete position patterns (14 ', 17'), wherein a switching device (20) is set up to check a predetermined switching condition (23) and when the switching condition is satisfied ( 23) to generate a switching signal, and wherein the adjusting device (11) is adapted to change in dependence on the switching signal between the first position pattern (14 ') and the at least one second position pattern (17'), wherein the switching device (20) a sensor element (21) for detecting contamination of the converter element (4) and / or a spectral en distribution (22) of the converter light (6), and the switching condition (23) includes that the fouling satisfies a predetermined fouling criterion and / or the spectral distribution (22) satisfies a predetermined distribution criterion (22 '). Lighting device (1) after Claim 1 in that a line pattern (Z) of parallel lines is defined by the first position pattern (14 ') and the at least one second position pattern (17') provides an identical line pattern (Z) offset from the line pattern (Z). Lighting device (1) according to any one of the preceding claims, wherein the adjusting device (11) is adapted, starting from the first position pattern (14 ') to superimpose this a continuous relative movement of the light beam (3) and the converter element (4). Lighting device (1) according to one of the preceding claims, wherein the contamination criterion and the distribution criterion (22 ') are respectively adapted to the sensor element (21). Lighting device (1) after Claim 4 wherein the contamination criterion defines a shadowing and / or contrasting surfaces or contrasting edges in a signal of the sensor element and wherein the sensor element comprises a camera. Lighting device (1) after Claim 4 wherein the distribution criterion specifies a proportion or an amount of a predetermined light frequency and / or a ratio of at least two predetermined light frequencies. Lighting device (1) according to one of the preceding claims, wherein the adjusting device (11) is adapted to move the converter element (4) and / or the light beam (3) to change the relative position. Lighting device (1) according to one of the preceding claims, wherein the optical device (7) is adapted to image the first tracer track (14) and / or the second tracer track (17) out of focus in the environment (8) by the respective tracer track ( 14, 17) detected outside a focal point of the optical device (7). Lighting device (1) according to any one of the preceding claims, wherein the optical device (7) is adapted to change an optical path for the converter light (6) at a change between at least two position patterns (14 ', 17') and thereby one by the change to compensate for the new position pattern (17 ') caused change in the light distribution (9) at least partially. Lighting device (1) according to one of the preceding claims, wherein the lighting device (1) is designed as a motor vehicle headlight. Method for generating a predetermined light distribution (9) in an environment (8) of a lighting device (1), wherein: a light source (2) generates a light beam (3) from excitation light (3 '), a converter element (4) generates converter light (6) upon excitation by the excitation light (3 '), - An optical device (7), the converter light (6) in the environment (8) aligns, and - an adjusting device (11) a predetermined first position pattern (14 '), which provides a sequence of several relative positions of the light beam (3) with respect to the converter element (4) sets, wherein by the first position pattern (14') total on the converter element ( 4) caused by a light spot (5) of the excitation light (3 ') first tracer track (14') is caused, from which results in alignment by the optical device (7) the predetermined light distribution (9), wherein the lighting device (1) is configured redundantly by at least one second position pattern (17 ') being provided by the adjusting device (11), by which a second light path (17) different from the first light track (14) is defined, from which, when aligned by the optical device (FIG. 7) likewise the predetermined light distribution (9) or a light distribution which fulfills a predetermined similarity criterion with respect to the predetermined light distribution (9), wherein a sequence of cyclically repeated positions is defined by the first position pattern (14 ') and the at least one second position pattern (17') provides the sequence offset by a predetermined spatial offset (18), the setting device (11) being arranged thereto is to switch, at least temporarily, between a plurality of discrete position patterns (14 ', 17'), wherein a switching means (20) is adapted to check a predetermined switching condition (23) and to generate a switching signal when the switching condition (23) is satisfied, and wherein the adjusting device (11) is set up to change between the first position pattern (14 ') and the at least one second position pattern (17') as a function of the switching signal, the switching device (20) comprising a sensor element (21) for detecting contamination the converter element (4) and / or a spectral distribution (22) of the converter light (6) and the switching condition (23) implies that the pollution meets a predetermined contamination criterion and / or the spectral distribution (22) satisfies a predetermined distribution criterion (22 ').

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