WO2017059472A1

WO2017059472A1 - Lighting device comprising a laser light module

Info

Publication number: WO2017059472A1
Application number: PCT/AT2016/060069
Authority: WO
Inventors: Andreas Luger
Original assignee: Zkw Group Gmbh
Priority date: 2015-10-05
Filing date: 2016-09-23
Publication date: 2017-04-13
Also published as: AT517734A1; AT517734B1

Abstract

The invention relates to a lighting device (1) having at least one laser light module (2), wherein the laser light module (2) comprises at least one laser light source (3) and at least one light-emitting region in the form of at least one conversion element (4), and wherein when the at least one laser light source (3) is switched on, said at least one laser light source (3) emits a laser light beam (L1, L2) so that the at least one conversion element (4) is irradiated by at least one laser light beam (S1, S2), and wherein a diagnostic device (5) is provided, which is designed for checking the functioning of the laser light module (2), and wherein the at least one conversion element (4) emits light (W1, W2), in particular white light, e.g. mixed light, in particular white mixed light. At least one optically active optic element (6) is provided, which optic element (6) can assume a locked state, in which locked state the optic element (6) weakens laser light beams in terms of the irradiation strength thereof, and wherein the at least one optic element (6) is arranged such that laser light beams output from the laser light module (2) must pass through the optic element (6), and wherein the at least one optic element (6) can be controlled in accordance with information from the diagnostic device (5) in such a way that in the event of an inability to function of the laser light module (2) determined by the diagnostic device (5), the at least one optic element (6) is switched into the locked state or remains in the locked state.

Description

LIGHTING DEVICE WITH A LASER LIGHT MODULE

The invention relates to an illumination device having at least one laser light module, wherein the laser light module has at least one laser light source and at least one light emitting region in the form of at least one conversion element, and wherein at least one laser light source is switched on, at least one laser light source emits a laser light beam, so that's at least one

Conversion element is irradiated with at least one laser light beam, and wherein a diagnostic device is provided, which is adapted to check the laser light module for its functionality, and wherein the at least one

Conversion element light, in particular white light, e.g. Mixed light, in particular white mixed light, emitted.

Furthermore, the invention relates to a headlamp, in particular motor vehicle headlamp, with at least one such lighting device.

In addition, the invention also relates to a light module for a headlight, in particular for a motor vehicle headlight, which at least one such

Lighting device comprises or which is in the form of such

Lighting device is formed.

A laser light module is a light source containing one or more laser light sources, e.g. one or more semiconductor laser and / or one or more laser diodes, comprises which / which together or emit a largely collimated light beam.

Furthermore, such a laser light module comprises at least one conversion element,

in particular a wavelength conversion element, as described below.

Lasers usually emit monochromatic light or light in a narrow

Wavelength range off. In a motor vehicle headlight, however, white mixed light is desired or required by law for the radiated light, so that

Laser light sources in a motor vehicle headlight can not be used easily. For converting monochromatic light into white or polychromatic light especially in connection with white light emitting diodes (LEDs) or

Luminescence conversion LEDs, often used so-called conversion elements.

Such a conversion element is e.g. in the form of a photoluminescent converter or photoluminescent element or comprises at least one

Photoluminescence converter or at least one photoluminescent element. These usually have at least one photoluminescent dye. The light of a typically colored (e.g., blue) light (also referred to as "excitation light") LED excites the photoluminescent dye for photoluminescence, whereupon the light

Photoluminescent dye itself emits light of other wavelengths (e.g., yellow). In this way, part of the irradiated light of one wavelength range can be converted into light of another wavelength range. As a rule, a further portion of the incident light (excitation light) is scattered and / or reflected by the conversion element. The scattered and / or reflected light and that through

Photoluminescence emitted light then superimpose additively and result in e.g. to white mixed light. The mechanism of photoluminescence can be distinguished depending on the lifetime of the excited state in fluorescence (short life) and phosphorescence (long life).

The conversion elements are between reflective and transmissive

Distinguished conversion elements. In reflective conversion elements, the light converted by the conversion element is emitted on the same side from which the excitation light strikes the conversion element. In transmissive

Conversion elements, the converted light from the side which faces away from the side on which the excitation light impinges emitted.

The present invention is suitable in principle for both laser light modules with transmissive and reflexive conversion elements.

The field of application of the present invention is predominantly in the field of motor vehicle headlights. However, the invention can also be used in other areas, such as in the automotive taillights area or for lights inside a vehicle, especially a motor vehicle. The invention can be used in particular in the entire motor vehicle sector (cars, trucks, motorcycles, etc.). The advent of laser technology in the automotive headlamp industry is bringing a series of new challenges, especially in the field of laser safety. The one in one

Headlamp used laser or laser light modules usually have such benefits that they are to be regarded as laser devices of Class 4 (according to IEC60825-1), for example, a power in the range of 4 watts; this corresponds to the highest possible hazard potential by laser systems. As long as a laser module is undamaged, the danger potential is similarly low, as with known LED headlights. On the other hand, if the laser module is restricted in its functionality, e.g. damage (e.g., damaged conversion element, e.g., damaged phosphor layer, for example) may cause laser light to leak, which can result in severe eye injury to living beings, particularly humans.

In order to avoid such accidents, special laser safety devices are required. The laser modules currently in use have integrated a special protection system that detects damage or malfunction of the laser module via sensors, and subsequently detects a specific signal level on a laser

Output diagnostic line. A higher-level control unit checks the diagnostic signal on the diagnostic line and switches off the laser module if necessary. The time until the laser module is switched off, for example, 250 ms. Will that be

However, if the diagnostic signal is ignored, the damaged laser remains illuminated.

In the simplest case, a diagnostic device consists of at least one sensor or a diagnostic device comprises at least one sensor, or it is one

Diagnostic device associated with at least one sensor. For example, the sensor may be a photodiode. Based on the photon flux measured by the photodiode, e.g. It can be determined whether harmful laser light or too much harmful laser light emerges from the laser light module or can escape. For this purpose, the photodiode transmits measurement signals, in particular current signals as a function of the photon flux, to the diagnostic device. The strength of the measurement signal, for example the current signal is related to limits and from this evaluation, a diagnostic signal is generated. This diagnostic signal is typically in turn a current signal, with two levels - according to the functionality or non-functioning of the

Laser light module. Accordingly, of course, several such sensors, such as photodiodes

be provided, which are arranged at different positions in the lighting module and / or in the laser light module.

The sensors measure e.g. the excitation laser light (blue light), wherein a sole evaluation of the corresponding output signal for monitoring the

Functioning can be sufficient.

Alternatively or additionally, different color channels can also be measured in the mixed light (red light components and / or green light component and / or blue light components), and the diagnostic device compares these measured values with one another and / or sets them in relation to predetermined limit values and decides on the basis of these

Information about the functionality of the laser light module. The

Functionality of the conversion element and thus of the laser light module can, for example, directly derived from the measurement levels (for example, a red light measurement = zero, i.e. no red light component in the mixed light, means that the converter is defective or is no longer in the correct position). In addition, a difference and / or quotient evaluation can be performed to provide additional parameters for the

Decision to determine whether the functionality is given or not.

It can, as will be described, be provided that directly on hand

Information of the diagnostic device is decided on the inventive "shutdown", wherein optionally may be provided that a parent

Headlamp control unit on the operating state of the laser light module or the

Lighting device is informed, but is not involved in the shutdown process itself.

However, it can also be provided that the diagnostic device transmits the ascertained information or the information that functionality or inoperability is present to the control unit, which then causes the "shutdown" according to the invention.

In this case, "functional capability" of the laser light module is to be understood in particular as meaning that the laser light module does not emit dangerous laser light If no dangerous laser light emerges from the laser light module, the laser light module is "in working order" Functioning is given. If the check by the diagnostic device shows that dangerous laser light is emitted, then it is "non-functional".

The functionality may e.g. can be determined by measuring green and / or red components in the laser light module, i. from the at least one conversion element radiated mixed light. If the green and / or red component is outside a defined value range and / or below a defined value

Limit value or below defined limits for red or green, it will

Laser light module classified as non-functional.

Alternatively or in addition to the classification described above, the non-functional ability can also be determined by means of a change in the ratio of red to blue in the mixed light.

As an alternative or in addition to the classifications described, the non-functional ability can also be radiated by means of an excessive blue component in the radiated

Mixed light can be determined. This also applies analogously to excitation light sources from the UV range (laser emission wavelengths less than 400 nm).

In particular, the at least one photodiode is wavelength-sensitive, and preferably the diagnostic device comprises (or consists of, or is associated with) two or more such wavelength-sensitive photodiodes. It is also possible to use identical photodiodes with upstream different color filters. Thus, on the one hand, the laser power can be measured before impinging on the conversion element, but further light fluxes of the converted white light (for example, the blue, red, green components) can also be measured. Is e.g. the measurement signal of red light is equal to / nearly zero, so the functionality is no longer given. It can also be provided to set the blue light component in the light originating from the conversion element in relation to the excitation power of the laser light, or the individual wavelength-specific measurement signals from the conversion mixed light can be used to control the correct color distribution of the fluorescence.

More generally, "healthiness" or "non-healthiness" is considered to be functional if the measurement signals and / or their relationships lie within certain predetermined target ranges. In particular, is one of these measurement signals or one of these relationships outside its defined

Target ranges, this means the "non-functioning" of the laser light module.

The absolute values of the target ranges of the measurement levels depend on the individual

Laser light modules, which are supplied by the respective manufacturer usually together with the diagnostic device. For example, it may be provided in the case of laser light modules that the status changes (= diagnostic signal jumps from the state "functional" to "non-functional") if the green-to-blue ratio deviates by 30% from the predefined setpoint.

If this exemplary barrier is reduced (for example, 15%), then you increase security, but also produces more failures.

A reasonable range for the above ratio is between 15% and 30%.

It is an object of the invention to provide a lighting device comprising at least one laser light module, in which, even in the case of non-functioning of the laser light module, the escape of dangerous laser light radiation, in particular high intensity laser light beams in a tightly focused beam with small divergence, from the lighting device can be prevented.

This object is achieved with an illumination device mentioned above in that according to the invention at least one optically active optical element is provided, which optical element can assume a blocking state, in which blocking state the

Optic element attenuates laser light rays in terms of their irradiance, and wherein the at least one optical element is arranged such that of the

Laser light beam exiting laser light rays must pass through the optical element, and wherein the at least one optical element in response to information of the diagnostic device is controlled such that at a diagnosed by the diagnostic device non-functioning of the laser light module, the at least one

Optic element is switched to the blocking state or remains in the blocking state. If the non-functional capability of the laser light module is thus determined, the blocking state of the at least one optical element is activated or remains activated, so that no light, in particular no laser light, can emerge from the illumination device or the emergent light, in particular exiting laser light before exiting, such as in particular further described yet, is so weakened that no danger is given.

Furthermore, this object is achieved with a headlight, in particular a motor vehicle headlight, with at least one such lighting device.

In addition, this object is still achieved with a light module for a headlight, in particular for a motor vehicle headlight, which comprises at least one such lighting device or which in the form of such

Lighting device is formed.

It can be provided that, in the blocking state, the at least one optical element attenuates laser light beams with respect to their irradiance, in that the at least one optical element is light-scattering, in particular highly scattering.

This strongly scattering state causes the opening angle of a laser beam passing through the optical element to increase significantly, and thus the

Irradiance of the laser beam in the blocking state of the optical element is significantly lower than without optical element or in an on state of the optical element (see the comments below). The required safety distance to the

Lighting device shortened accordingly.

Such an optically active optical element has e.g. the property that it can switch between a strong light-scattering state and a substantially completely transparent state. For example, the state which the optical element assumes depends on an electrical voltage applied to the optical element.

Typically, this means "no" voltage = transparent, and "applied" voltage = scattering. Such an optically active optical element may, for example, be a PDLC disk. The PDLC disk has the property that it may vary depending on the one between a transparent and a strongly scattering state.

Output luminous flux maximum

laser module

maximum

Output [Im] Loss [%] Loss [%]

[cd] without PDLC disc 51.68 0.00 31.720.5 0.00

PDLC disc

(more transparent 39.20 24.15 20.867.1 34.22

Status)

PDLC disc

6,95 86,55 36,8 99,88

(scattering state)

By a "disk" is meant in this text a disc-shaped body which is not restricted in its cross-section, it may therefore be a circular disc, but the disc may also have a rectangular or square cross-section or any other shape suitable for the disc According to the purposes of the invention, suppose.

It can be provided that, in the blocking state, the at least one optical element attenuates laser light beams with respect to their irradiance, in that the at least one optical element has a light-absorbing design.

With a light-absorbing optical element similar attenuations can be achieved as in the above-mentioned table.

It is therefore preferable that the optical element in its blocking state has a lower transmittance than in its on-state. In particular, it is advantageous if the optical element can provide this property for the wavelength of the laser light used, for example for blue laser light. However, it can also be provided that an optical element is used which provides this property essentially in the entire wavelength range of the visible light. As a rule, only an optically active optical element will be used. at

Using two or more optical elements, these can be functionally, i. in particular be identical from their blocking states ago, but it may also be that different functioning optical elements, which differ in particular by different blocking states are used.

It can be provided that the at least one optical element can assume at least two optical states, the blocking state and an on-state, wherein in the on-state the optical element

+) is more translucent than in the blocking state, preferably substantially completely translucent, and / or

+) less light scattering than in the blocking state, in particular substantially non-light scattering.

It can be provided that, in the on-state, the at least one optical element is optically transparent, in particular completely optically transparent, or translucent.

Optimally, the optical element in the transmission state is 100% transparent, in particular in the relevant wavelength range for visible light.

It is preferably provided that the at least one optical element can be controlled in dependence on information of the diagnostic device in such a way that the at least one optical element is switched into the on-state or in the case of a functioning of the laser light module established by the diagnostic device

Pass state remains.

That is, the control can be performed such that the optical element is usually in the

Lock state is, so no case laser light

+) can escape to the outside, or in any case

+) the outgoing laser light is strongly attenuated, or

+) is scattered in such a way that no bundled laser beam can reach the outside. Only when the functionality of the laser light module has been determined, accordingly no per se no dangerous laser light to the outside of the

Lighting device can get out, the on state of the

Optic element activated.

It may be advantageous if the diagnostic device is arranged in the laser light module or is part of the laser light module.

In this way, the diagnostic device is independent of external influences.

A laser light module in which the diagnostic device and also at least one optically active optical element are part of the laser light module, eg. integrated into the laser light module, forms an independent module, which alone can guarantee the laser safety according to the invention, in particular when the diagnostic device can control the optical element itself directly, because then none

Data communication to a parent headlight control unit is necessary.

It can be provided that the at least one optical element directly from the

Diagnostic device is controlled.

The advantage of controlling the at least one optical element directly via the diagnostic device, and preferably still arranging the diagnostic device in the laser light module, is that the safety circuit according to the invention is independent of external influences.

Moreover, an advantage of this embodiment is that, in the event that the

Laser light module from the lighting device or such a lighting device is removed from a headlight or even removed, and is turned on in this disassembled state, the protective effect is still given.

It can be provided that the diagnostic device with an external control device, in particular a vehicle-side or headlight-side controller or a Control unit of the lighting device, is connected and this control unit controls the at least one optical element.

The term "external" refers to the laser module, i.e., such a controller is located outside the laser module

Control unit also be used to control other headlamp functionality and / or other lighting units than the laser module or control.

It can be provided that the at least one optical element is switched into the blocking state as soon as the non-operationality of the laser light module is detected.

However, in the period until the switching of the optical element, an escape of dangerous laser light may still occur. Likewise, the case may arise that from a further error case there is no switching of the optical element in the

Lockout comes.

It is therefore advantageous if the at least one optical element is basically in the blocking state and is switched into the on-state by the diagnostic device only when the functionality of the laser light module is recognized.

It is advantageous if the functionality of the laser light module through the

Diagnostic device, preferably at regular intervals (cycle time), e.g. every 175ms, checked.

The check is thus preferably de facto running, i. permanently and preferably during operation.

It can be provided that the at least one optical element is designed as a disk.

It can be provided, in particular, that the at least one optical element is formed at least partially, preferably completely from polymer-dispersed-liquid-crystal (PDLC), or at least partially from one, preferably from a suspended particle device (SPD). PDLC is highly scattering in the blocking state and is transparent in the on state. Since the PDLC disc has a high transmission both in the transparent and in the strongly scattering state, there is no heating of the disc.

The switching time of a PDLC disc is typically in the range of 10 ms.

Furthermore, it can be provided that an optical device arranged downstream of the at least one conversion element in the light propagation direction is provided, which light emitted by the conversion element is in the form of a light distribution or a partial light distribution, e.g. in the form of a high beam spot, in an area in front of the

Illuminating device images.

Such a configuration is particularly important for a lighting device for a headlight, in particular a motor vehicle headlight, or for a light module for such a headlight, in particular motor vehicle headlights, of importance.

For example, it may be provided that the optical device comprises a reflector, e.g. an open-space reflector, and arranged in the light propagation direction after this reflector lens or lens arrangement, in particular a projection lens or

Projection lens assembly includes.

Embodiments of the headlamp optical device are approximately

a) Open space reflectors (without lens)

b) projection system (combination of reflector, in particular with elliptic or hyperbolic basic shape and projection lens (s))

c) direct-imaging lens systems

Accordingly, the at least one optical element can in principle be arranged at any desired position in the beam path.

It can be provided that the at least one optical element in

Seen light propagation direction is arranged immediately after the conversion element, for example in which it is part of the laser light module. Preferably, the optical element is in this case mounted in a light exit region of the laser light module and covers this light exit region preferably completely or at least in such a way that the entire light emerging from the laser light module must pass through the optical element.

It can be provided that the at least one optical element in

Seen light propagation direction after the optical device is arranged.

In this case, the optical element is preferably mounted in a light exit area of the lighting device and covers this light exit area

Lighting device preferably completely or at least in such a way that the entire light emerging from the lighting device must pass through the optical element.

It can be provided that the at least one optical element is arranged between the reflector and the lens or lens arrangement.

Preferably, the optical element is in this case mounted in a light exit region of the reflector and preferably covers this light exit region of the reflector completely or at least in such a way that the entire light emitted by the reflector has to pass through the optical element.

In the case of lens arrangements with a plurality of lenses, the at least one optical element or at least one of the optical elements could also be arranged between individual lenses.

It can be provided that the at least one optical element on its

Light entrance surface and / or at its light exit surface light reflecting, in particular light reflecting, is formed, e.g. by the light entry surface and / or the

Light exit surface with a light-reflecting, especially light-reflecting

Coating is provided.

The antireflection coating can be effected, for example, by means of an AR coating (anti-reflection coating) and / or a moth-eye structure. Due to the antireflective coating, the efficiency can be increased by approx. 10%. Furthermore, it can advantageously be provided that in the event of failure of the diagnostic device or in the event of failure of one or more measuring devices, eg sensors such as the sensors described above, which supply the diagnostic device with measurement information, the at least one optical element is switched into the blocking state or, if it is in the locked state, remains in this.

In the following the invention is discussed in more detail with reference to the drawing. In this shows

1 shows an exemplary basic construction of a known lighting device for a vehicle headlight or in the form of a vehicle headlight,

2 shows a lighting device from FIG. 1, according to the invention, according to a first embodiment of the invention,

3 shows a lighting device from FIG. 1, according to the invention, according to a second embodiment of the invention,

4 shows a lighting device from FIG. 1, according to the invention, expanded according to a third embodiment of the invention, FIG.

4a shows a lighting device similar to that of Figure 4, but without a lens,

Fig. 5 shows schematically a laser light module with integrated diagnostic device and

integrated optical element, with the optical element in the on state, and the corresponding, schematically represented light distributions,

FIG. 6 schematically shows the laser light module from FIG. 5, with the optical element in the blocking state, and the corresponding, schematically illustrated light distribution, which shows a significant decrease in the intensity of the laser light, FIG.

7a and 7b the transmission behavior of an optical element in the form of an SPD element in the blocking state (absorbing) and in the on-state (translucent),

8a and 8b the transmission behavior of an optical element in the form of a PDLC element in the blocking state (strongly scattering) and in the on-state (translucent), 9 shows a typical switch-on behavior of a lighting device according to the invention with functional laser light module,

10 shows the switch-on holding a lighting device according to the invention with non-functional laser light module, and

11 shows the switch-off behavior in the event of a failure in operation during operation of the lighting device.

FIG. 1 shows an exemplary lighting device 1 with a laser light module 2.

In general, the lighting devices according to the invention, and in particular the lighting devices described below, in particular for installation in a motor vehicle headlight, either directly or as part of a light module (or such lighting device may also be designed as a light module).

With such a lighting device, a law may be required

Light distribution or a part of such a light distribution can be generated. Such light distributions may be e.g. around dimmed light distribution (such as a

Low beam distribution, a fog light distribution or AFS functional city light, highway light, motorway light, bad weather light), daytime running lights distribution, high beam distribution, etc.

The lighting device or the laser light module can also be a device or a module that functions according to the laser scanning principle.

The essential components of such a laser light module 2 include at least one laser light source 3 and a conversion element 4, which converts the directed laser light beam of the at least one laser light source 3 into white light.

In the example shown, two laser light sources 3 are provided, which are of these

emitted laser light beams LI, L2 are bundled by an optical system 7 to a common directional laser light beam SL. This laser light beam SL hits the

Conversion element 4, which converts the laser light beam, in particular at least partially, into white light. The white light is emitted by the conversion element 4, applies to a downstream optical device 10, 11, and is of this as already described above in the form of relevant for a motor vehicle headlamp, especially legally prescribed light distribution or partial light distribution, eg in the form of a high beam spot, in an area in front of the lighting device 1 and in an area in front of a vehicle, in which the lighting device 1 is installed, mapped.

In the example shown, the downstream optical device is a reflector 10, e.g. an open space reflector, as well as an in

Light propagation direction behind this reflector arranged lens 11 or

Lens arrangement, in particular a projection lens or a projection lens system.

In the example shown, for the irradiation of the conversion element 4, the laser beam SL is deflected by a laser light beam deflection device, for example a reflector 9, in particular an elliptical reflector, which deflects the laser light onto the conversion element 4, so that a locally concentrated laser light energy density results in the conversion element ,

Preferably, but not necessarily, can still be provided that the laser light beam is split by a separate lens 8 or lens assembly in front of the reflector 9, so that the reflector 9, the conversion element 4 as accurately as possible in a defined area around a focal point or in the Focus of the reflector 9, which focus is in or on the conversion element 4, can illuminate. An alternative construction also works without a reflector or uses a deflection prism.

The conversion element 4 is a in the example shown

transmissive conversion element.

However, the present invention is also suitable for a lighting device with a reflective conversion element.

In addition, only one laser light source can be provided, in this case optics 7 are not necessary.

There may also be provided three or more laser light sources. Furthermore, a diagnostic device 5 is provided, either as an external unit to the laser light module 2, or as a unit integrated in the laser light module 2.

Design options of a diagnostic device 5 that can be used are described in the introduction to the description.

FIGS. 2 to 4 show extensions according to the invention of the illumination device 1 from FIG. 1. The features described as optional in conjunction with FIG. 1 can also be implemented as optional features in these extensions.

The illumination devices 1 from FIGS. 2 to 4 additionally each have an optically active optical element 6. Such an optical element 6 may be in the form of a disk, e.g. be designed as a rectangular or square disc, so it is, for example, a disc-shaped optical element. The object of such an optical element 6 in the most general scope of the invention is, in the on state (also referred to as "operating state") light, preferably white light or mixed light, which is emitted by the conversion element 4 to pass freely, and in the off state (also as

"Safety state") to prevent a collimated laser beam from escaping from the illumination device 1 or from the laser light module 2. Another error that can preferably be prevented also with the present invention is that at which laser beams can scatter without conversion The exit does not take place in a bundled classic laser beam, but still has a high hazard potential.

FIG. 2 shows a lighting device 1 according to the invention, in which the

Optical element 6 seen in the light propagation direction immediately after

Conversion element 4 is arranged and preferably part of the laser light module 2, i. is integrated in the laser light module 2.

Preferably, the optical element 6 is in this case mounted in a light exit region of the laser light module 2 and covers this light exit region preferably completely or at least in such a way that the entire light emerging from the laser light module 2 has to pass through the optical element 6. FIG. 3 shows a lighting device 1 according to the invention, in which the

Optical element 6 seen in the light propagation direction after the optical device 10, 11, i. is arranged in particular after the lens or lens assembly 11.

In this case, the optical element 6 is preferably mounted in a light exit area of the lighting device 1 and covers this light exit area

Lighting device 1 preferably completely or at least in such a way that the entire light emerging from the lighting device 1 must pass through the optical element 6.

FIG. 4 shows a lighting device 1 according to the invention, in which the

Optical element 6 seen in the light propagation direction between the reflector 10 and the lens or lens assembly 11 is arranged.

In this case, the optical element 6 is preferably arranged in a light exit region of the reflector 10 and covers this light exit region of the reflector 10

preferably completely or at least in such a way that the entire light emitted by the reflector 10 must pass through the optical element 6.

In the blocking state, the optical element 6 is designed such that it attenuates by the optical element 6 passing laser light beams with respect to their irradiance.

For example, the optical element 6 is light-scattering, in particular highly light-scattering, formed.

Fig. 4a shows an arrangement which is constructed analogously to that of Figure 4, with the difference that in the apparatus of Figure 4a, no lens 11 is provided and the reflector 10 is adjusted accordingly. The devices according to FIGS. 2 and 3 can also be modified accordingly.

FIG. 5 shows a laser light module 2 with a conversion element 4 and with an optical element 6 in the light exit region of the laser light module 2. Furthermore, the laser light module 2 has a diagnostic device 5, which can check the functionality of the laser light module 2. Furthermore, the laser light module 2 is assigned a control unit 12. The control unit 12 may be part of the laser light module, eg part of the in the Laser light module integrated diagnostic device, or an external control device, such as a headlight-side control device or a control device of the lighting device 1 be.

FIG. 5 shows the optical element 6 in the on-state in which the optical element is in a substantially completely transparent state.

The schematic light distributions in FIG. 5 show what happens in the event of a fault

Laser light module 2 could happen: on the one hand, in this case, a more or less "normal", that is uninfluenced light distribution, as you would from a

Lighting device with an illustrated laser light module 2 with the emitted light from the conversion element 4 would be generated (upper schematic light distribution) set, on the other hand, but about a damage to the laser light module 2 from this also a concentrated laser beam emerge (bottom

Light distribution).

In the schematic representation of FIG. 6, therefore, the optical element 6 is in the blocking state due to the detected error case (non-functioning) assumed in FIG. in a, in particular strong, light scattering state, so that the opening angle of a passing through the optical element laser beam increases significantly and thus the irradiance of the laser beam in the off state of

Optic element is significantly less than without optical element or in an on state of the optical element.

As can be seen in FIG. 6 in the right-hand area, shown very schematically, no light distribution is generated on the basis of the light originating from the conversion element 4, since light emitted by the latter no longer emerges from the light source

As a result of the attenuation (= strong decrease in intensity of the laser light or decrease in irradiance) as a result of the optical element, as a result of scattering and / or absorption of the laser light, may be increased as shown, the light distribution and the illuminance decreases significantly.

An optical element 6 used according to the invention can, as described above, distinguish between a (strongly) scattering state and a transparent, translucent state or between a (strongly) absorbing and a transparent,

change translucent state.

An example of a latter optical element is a so-called Suspended Particle Device (SPD) 6, which is shown roughly schematically in FIGS. 7a and 7b, and which is arranged between an absorbing (blocking) (FIG. 7a) and a translucent (blowing) state. (Figure 7b) can be switched.

Typically, such an SPD comprises a liquid crystal film 605, particularly a polymer liquid crystal film. This liquid crystal film 605 is composed of a

Polymer matrix with liquid crystals, e.g. Liquid crystal molecules or particles 604 having anisotropic (directional) optical properties in an electric field which are stochastically (random) oriented when no voltage is applied.

The liquid crystal film 614 or polymer matrix is sandwiched between two conductive elements 601, 602, e.g. coated polyester films, embedded. For example, an ITO layer (indium tin oxide) can serve as the conductive layer. If a voltage 603 is applied to the two conductive elements 601, 602, then the, for example "rod-like structured" liquid crystal (molecules) or particles 615 are oriented in a preferred direction, as is schematically indicated in FIG. 7b, and FIG SPD 6 becomes transparent or translucent, translucent, semitransparent), so that incident light rays L can pass through the optical element 6 substantially unhindered.

If the voltage is removed (power off), then orient the

Liquid crystals again after a disordered state and the disc is again opaque (opaque), as shown in Figure 7a, where the incident light rays L scattered (L ', L ").

FIGS. 8a and 8b show, roughly schematically, an optical element 6 in the form of a PDLC element, which can be switched between a strongly scattering state and a transparent or preferably translucent state.

Between two glass plates 601, 602 a liquid 614 is accommodated, which contains a liquid crystal (Liquid Crystal) layer 615. If a voltage 603 between the Placed glass slides 601, 602, align the liquid crystals 605 of the layer 604, incident light L can pass through the now transparent or translucent optical element 6 substantially unhindered. When the voltage is removed or an AC voltage is applied, the liquid crystals 605 disperse and the disc becomes opaque (opaque) again, as shown in FIG. 8a, where the incident light beams L are substantially absorbed at the optical element 6.

FIG. 9 shows a typical switch-on process of a lighting device with a laser light module, namely in the upper area a known lighting device and in the lower area an advantageous lighting device according to the invention. If a lighting device is switched on at time t = 0, the laser light module emits laser light from this point in time, which laser light is correspondingly converted into white light or mixed light as described above. Thus, white light or mixed light is already emitted by the illumination device at full intensity (I = 1) at time t = 0 (upper region of FIG. 9).

In an advantageous lighting device according to the invention, however, is a check of the functionality until it is completed, no laser beam and no white or mixed light from the "laser headlamp module" emerge, ie there is no white light or mixed light (despite switched on / switched The test was carried out after about t = 250 ms, when this has been successfully completed, the optics element is switched to Durchläse, white light or mixed light is from this point on with full intensity (I = 1 ) emitted.

Figure 10 shows the turn-on operation of a non-functional laser light module in which, for example, the conversion element is damaged or removed, or the or one of the laser light sources is defective, e.g. moved in their position, etc. is. According to the prior art (upper portion in Figure 10), the laser light module in

Switching on at t = 0 is switched on, the laser light module emits in this example

Laser light with full intensity (I = 1) (like the composition of the false light

Basically, depends heavily on the degree of damage of the conversion element from), which could escape to the outside. Only after t = 250ms, here the non-functioning is recognized, the laser light module is switched off (1 = 0). In the lower area of the intensity profile of the laser light, which could escape from the illumination device is shown. When switching on the

Lighting device, the laser light module is turned on and generates laser light at full intensity, however, the optical element is in the blocking state, so that in the period of t = [0, 250ms] no laser light can escape from the lighting device (1 = 0). At the time t = 250 ms, the diagnostic device has detected that a non-functional capability is present, accordingly, the optical element remains in the blocking state, it can continue to leak no laser light from the lighting device (1 = 0).

Finally, FIG. 11 shows the behavior in the event of non-functioning of an originally intact laser light module, e.g. after a defect of

Conversion element. The non-operationality occurs at a time t = T. The upper part of Figure 11 shows a known lighting device. In the period t = [0, T], the intensity of the exiting laser light I = 0, since the laser light module is intact. At t = T, the laser light module becomes non-functional, in the unfavorable,

In the case shown, the control unit of the lighting device, for example because it does not receive a diagnostic signal, does not switch off the laser light module, laser light may escape, e.g. the laser beam previously deflected completely onto the conversion element can now emerge unhindered from the illumination device (1 = 1). In the best case, in which the control unit receives the correct diagnostic signal (after approx. 250ms), it shuts off the laser light module after 250ms so that no more laser light can escape.

In the lower part, which shows the behavior of an inventive, advantageous

Lighting device shows, about 250ms after t = T, the non-functionality is detected, and the optical element is switched directly via the diagnostic signal in the blocking state, so that subsequently no laser light beam with relevant intensity (I = 0) can escape. The typical reaction time for switching an optical element between on-state and off-state is about 10ms, so that about 260ms after detection of non-functioning no more dangerous laser light from the

Lighting device can escape. If the diagnostic signal fails as a result of, for example, an error or defect, the optical element is also switched to the blocking state, so that no laser light can escape even in this case. An advantage is in particular if, for example, the control unit due to

Line problems LaserEngine or the laser light module does not turn off, in this case, the switching of the optical element prevents unwanted laser light leakage. This gives a control device independent of a safety device.

The advantages of the invention shown in FIGS. 9-11 are obtained, in particular, when the control of the at least one optical element is controlled directly by the diagnostic signal, without an intermediary control device, such that the optical element only assumes a transparent or translucent state. if the laser module is functional, ie the diagnostic device reports no error. If an error is detected or even if, for example, the diagnostic signal fails at all, the optical element remains in a strongly scattering state.

Claims

1. Lighting device (1) with at least one laser light module (2), wherein the laser light module (2) at least one laser light source (3) and at least one

having at least one laser light source (3) this at least one laser light source (3) emits a laser light beam (LI, L2), so that the at least one conversion element (4) with at least one laser light beam (Sl, S2) is irradiated, and wherein a diagnostic device (5) is provided which is adapted to check the laser light module (2) for its functionality, and wherein the at least one conversion element (4) light (Wl , W2), in particular white light, eg Mixed light, in particular white mixed light emitted, characterized in that at least one optically active optical element (6) is provided, which optical element (6) can assume a blocking state, in which blocking state the optical element (6) attenuates laser light beams with respect to their irradiance, and wherein the at least one optical element (6) is arranged such that laser light beams emerging from the laser light module (2) have to pass through the optical element (6), and wherein the at least one optical element (6) depends on information of the

Diagnostic device (5) can be controlled such that at a diagnosed by the device (5) non-functioning of the laser light module (2) the at least one optical element (6) is switched to the blocking state or remains in the blocking state.

2. Lighting device according to claim 1, characterized in that in the blocking state, the at least one optical element (6) laser light beam attenuates in terms of their irradiance by the at least one optical element (6) light scattering, in particular strongly scattering, is formed.

3. Lighting device according to claim 1, characterized in that in the blocking state, the at least one optical element (6) laser beam attenuates in terms of their irradiance by the at least one optical element (6) is designed to absorb light.

4. Lighting device according to one of claims 1 to 3, characterized in that the at least one optical element (6) can assume at least two optical states, the blocking state and an on-state, wherein in the on-state, the optical element (6)

5. Lighting device according to claim 4, characterized in that in the on state, the at least one optical element (6) is optically transparent, in particular completely optically transparent, or translucent.

6. Lighting device according to one of claims 1 to 5, characterized

in that the at least one optical element (6) is dependent on

Information of the diagnostic device (5) can be controlled such that in a diagnosed by the diagnostic device (5) functioning of the laser light module (2), the at least one optical element (6) is switched to the on state or remains in the on state.

7. Lighting device according to one of claims 1 to 6, characterized

in that the diagnostic device (5) is arranged in the laser light module (1) or is part of the laser light module (1).

8. Lighting device according to one of claims 1 to 7, characterized in that the at least one optical element (6) directly from the diagnostic device (5) can be controlled.

9. lighting device one of claims 1 to 8, characterized in that the diagnostic device (5) with an external control device (12), in particular a vehicle-side or headlight-side control device or a control device of the lighting device is connected, and this control device (12) the at least one Optical element (6) controls.

10. Lighting device according to one of claims 1 to 9, characterized in that the at least one optical element (6) is basically in the blocking state and is switched only upon detection of the functionality of the laser light module (1) by the diagnostic device (5) in the on state ,

11. Lighting device according to one of claims 1 to 10, characterized

characterized in that the functionality of the laser light module (1) by the

Diagnostic device (5), preferably at regular intervals, e.g. every 175 ms, is checked.

12. Lighting device according to one of claims 1 to 11, characterized

characterized in that the at least one optical element (6) is formed as a disc.

13. Lighting device according to one of claims 1 to 12, characterized

in that the at least one optical element (6) is formed at least partially, preferably completely from polymer-dispersed-liquid-crystal (PDLC), or at least partially from one, preferably from a suspended particle device (SPD).

14. Lighting device according to one of claims 1 to 13, characterized

characterized in that a the at least one conversion element (4) in

Seen downstream direction of the optical device (10, 11) is provided, which radiated by the conversion element (4) light (Wl, W2) in the form of a light distribution or a partial light distribution, e.g. in the form of a high-beam spot, in an area in front of the lighting device (1) images.

A lighting device according to claim 14, characterized in that the optical device comprises a reflector (10), e.g. a free-form reflector, as well as an in

Light propagation direction according to this reflector (10) arranged lens (11) or

Lens arrangement, in particular a projection lens or projection lens assembly comprises.

16. Lighting device according to one of claims 1 to 15, characterized

characterized in that the at least one optical element (6) in the light propagation direction Seen immediately after the conversion element (4) is arranged, for example, in which it is part of the laser light module.

17. Lighting device according to one of claims 1 to 15, characterized

in that the at least one optical element (6), viewed in the direction of light propagation, is arranged after the optical device (10, 11).

18. Lighting device according to claim 15, characterized in that the at least one optical element (6) between the reflector (10) and the lens (11) or lens arrangement is arranged.

19. Lighting device according to one of claims 1 to 18, characterized

characterized in that the at least one optical element (6) is formed on its light entry surface and / or on its light exit surface reflecting light, in particular light reflecting, e.g. in that the light entry surface and / or the light exit surface is provided with a light-reflecting, in particular light-reflecting, coating.

20. Lighting device according to one of claims 1 to 19, characterized

characterized in that in case of failure of the diagnostic device or in case of failure of one or more measuring devices, e.g. Sensors, which provide the diagnostic device measurement information, the at least one optical element (6) is switched to the blocking state or remains in the blocking state.

21. Lighting device according to one of claims 1 to 20, characterized

in that the lighting device is designed as a light module for a headlight, in particular for a motor vehicle headlight, or as a headlight, in particular as a motor vehicle headlight.

22 headlights, in particular motor vehicle headlights, with at least one lighting device according to one of claims 1 to 20.

23. Light module for a headlight, in particular for a motor vehicle headlight, which at least one lighting device according to one of the claims 1 to 20 or which is formed in the form of a lighting device according to one of claims 1 to 20.