DE102017217915A1 - Light conversion device, manufacturing method therefor and lighting device - Google Patents

Abstract

The invention relates to a light conversion device (68) for a lighting device (10), comprising a conversion element (72) which is configured to convert a primary light beam having a primary wavelength into a secondary light beam having a secondary wavelength different from the primary wavelength. According to the invention, it is proposed to provide an electrically conductive conductor structure (84) which comprises at least one conductor element (86), wherein the conductor element (86) at least partially within the conversion element (72) and / or on at least one side of the conversion element (72) Surface of the conversion element (72) is arranged.

Description

The invention relates to a light conversion device for a lighting device, comprising a conversion element which is configured to at least partially convert a primary light beam having a primary wavelength into a secondary light beam having a secondary wavelength different from the primary wavelength. Furthermore, the invention relates to a lighting device and a method for producing a light conversion device.

Light conversion devices are used in so-called "laser activated remote phosphor" (LARP) systems to convert by means of a conversion element of a laser irradiated, usually narrow-band, blue primary light at least partially in secondary light, such as yellow conversion light, which then in the superposition of the yellow Conversion light with the proportion of unconverted primary radiation white mixed light (useful light) results, which is preferred for applications in vehicle headlights in the EC-standardized white field of the CIE color chart. The term phosphorus is here colloquially referred to a phosphor element (conversion element), which is adapted to convert primary light into secondary light, wherein the chemical element phosphorus does not have to be included. So the term phosphor material should not imply that the chemical element phosphorus must be included.

In general, the wavelength conversion is preferably a down-conversion, so the conversion radiation (secondary light beam) is lower energetic (longer wavelength) than the pump radiation (primary light beam). The pump radiation is preferably blue light. In general, a pump radiation in a shorter wavelength range is conceivable, for example in the UV range. Furthermore, conversion radiation in the infrared is also conceivable (for example for a night-vision function or for data transmission), but it is preferably visible light.

A wavelength-converted part of a primary light emitted from a wavelength conversion element or phosphor is called a conversion light. This is emitted as a conversion light beam from the phosphor element.

The phosphor is also referred to as a wavelength conversion element. A phosphor can be understood as meaning any substance, in particular solid, which makes wavelength conversion possible. The wavelength conversion can be based, for example, on fluorescence or phosphorescence. It may include up-conversion to shorter wavelengths and down-conversion to longer wavelengths

Depending on the selected wavelength conversion element, a primary radiation (excitation light) can be converted into conversion light of other wavelengths, with a down-conversion, for example, into blue, green, yellow, red light or IR radiation.

With the combination of a pump radiation source of high power density, such as a laser, and a spaced apart arranged fluorescent element that emits light in response to the pump radiation towards conversion light, light sources high luminance can be realized. The pump radiation is incident on an irradiation surface of the phosphor element, and the conversion light is emitted at a radiating surface. When operated in transmission, the Einstrahl- and the radiating surface are opposite to each other in the present relevant operation in reflection they coincide. Not necessarily the entire pump radiation must be converted (full conversion), but also an unconverted part thereof with the conversion light in mixture can be used as illumination light (partial conversion).
The conversion light is emitted at the emitting surface typically Lambertsch. Even if the pump radiation upstream of the phosphor element is usually bundled, ie a corresponding beam has an opening angle of only a few degrees, in the case of partial conversion the unconverted part of the pump radiation, for example, due to scattering processes in the phosphor element, fanned out similarly to the conversion light.

In a LARP system usually two different converter arrangements can be used. The converter arrangement can be designed, for example, as a transmissive arrangement or as a reflective arrangement. The advantage with the reflective variant lies in the better thermal connection of the converter, since, in contrast to the transmissive variant, no optically transparent heat sink, such as a substrate, for example, on which the phosphor is arranged, is required. Thus, for example, in the reflective variant, the phosphor can be arranged on a metallic mirror whose thermal conductivity is markedly increased in comparison with the light-transmitting substrate, such as sapphire. The main advantage of the transmissive variant lies in the device-technically simple design of a complete optical system. Thus, a first optical system for supplying the excitation radiation to the phosphor can be provided in the beam path between the laser diode and the phosphor. Subsequent to the phosphor, a further optics can be arranged, which images useful light emitted by the phosphor. In the reflective variant both optics or optical subsystems are arranged conditionally in the same half-space, which is expensive in terms of device technology and can degrade system efficiency. In the case of the transmissive variant, on the other hand, the optics or the optical subsystems can be arranged in a respective half space, ie before and after the phosphor. This leads in particular to a more generous installation space for the optics.

In transmissive laser-phosphor arrays, the phosphor is usually applied to a transparent support. Due to the high heat development in the phosphor (for example by Stokes shift) support materials are selected with a high thermal conductivity, for example sapphire.

In reflective laser-phosphor arrangements, the phosphor is usually applied to a reflective support, in particular to a reflective metal, for example aluminum or coated aluminum.

Suitable phosphors may be selected from a group of materials containing oxidic or (oxi-) nitridic materials such as garnets, orthosilicates, nitrido (alumo) silicates, nitridoorthosilicates or halides or halophosphates. Concrete examples may include doped yttrium aluminum garnets such as YAG: Ce, doped lutetium-aluminum garnets such as LuAG: Ce, doped silicon nitride materials such as Eu-doped CaAlSiN3 or the like. Doping materials may generally be selected from a group including, for example, Ce, Tb, Eu, Yb, Pr, Tm and / or Sm. Furthermore, additional dopants are possible, so co-dopants.

The phosphor element may for example comprise a matrix material, such as a ceramic, a glass or a plastic material, in which then the phosphor is arranged distributed over discrete areas, for. B. molded in grains of ceramic or in particle form in the glass / plastic. The phosphor element may, for example, also be a monocrystal of the phosphor, such as a YAG: Ce monocrystal.

1. a) ein Emitter mit kleiner emittierender Fläche und möglichst homogener Leuchtdichte;
2. b) hohe optische Effizienz;
3. c) ein Sicherheitskonzept, um eine Degradation oder Beschädigung des Konversionselements zu registrieren; und
4. d) eine effiziente Entwärmung des Konversionselements.

For such a light conversion device, the following properties are necessary in particular:

1. a) an emitter with a small emitting surface and the most homogeneous possible luminance;
2. b) high optical efficiency;
3. c) a security concept to register a degradation or damage of the conversion element; and
4. d) efficient heat dissipation of the conversion element.

Previously known devices solve only some of the aspects a) to d), which are recognizable in a conflict of goals. In particular, there is a need for systems in which the security concept as well as the efficient heat dissipation are realized simultaneously.

The invention has for its object to improve light conversion devices of the type mentioned, in particular to the effect that the desired properties can be realized as possible simultaneously.

As a solution, the subject of the independent claims is proposed.

According to the invention, it is proposed to provide an electrically conductive conductor structure which comprises at least one conductor element, wherein the conductor element, preferably in terms of volume and / or surface, at least partially disposed within the conversion element and / or on at least one side of the conversion element on a surface of the conversion element. With the features according to the invention, the heat generated in the conversion element can be dissipated by means of the conductor structure. A volume embedding is given in particular when the conductor element is in contact with the conversion element on all its sides. An embedding in which at least one side of the conductor element is exposed on a surface of the conversion element and at least one side viewed in the thickness direction of the conversion element below the surface in contact with the conversion element is referred to as areal. Furthermore, the resistance or the impedance or the inductance of the conductor structure can be measured in order to detect any impairment or damage to the conductor structure or the conversion element. Due to the improved cooling, a smaller area can be used as an emitter or a smaller area can be illuminated with the laser. Thus, the available for the conversion laser radiation power per unit area and thus also the emission-side luminance of the conversion radiation or the useful radiation, whereby the optical efficiency can be increased. Overall, this results in an improved light conversion device compared to the known embodiments.

Advantageous developments emerge by features of the dependent claims.

It is preferred that the conversion element is formed substantially as a plate element having a first broad side, a second broad side and an edge region, wherein the conductor element on the surface of at least one of Broad sides is arranged and / or wherein the conductor element is arranged on one of the broad sides and at least partially on the edge region. Preferably, the conductor element is arranged on the entire edge region. It is preferred that the conversion element is designed as a rectangular, square or circular plate element. Depending on the geometry or the shape of the conversion element and the arrangement of the conductor structure, the heat dissipation and the optical efficiency can be improved and adapted to the desired installation conditions. The metallic conductor element, for example, can additionally reflect back light emerging from the conversion element, which would otherwise be lost for the conversion. Thus, the optical efficiency can be increased.

It is preferred that the conductor structure comprises a first conductor element and a second conductor element, wherein the first conductor element is arranged on the first broad side and the second conductor element on the second broad side, so that the conversion element forms a dielectric of a capacitor arrangement formed from the conductor elements. With this embodiment, the reliability with which an impairment of the conversion element or the conductor structure can be detected can be increased.

It is preferred that the conductor structure comprises a first conductor element and a second conductor element. Preferably, the first conductor element on the first broad side and the second conductor element on the second broad side is arranged. Preferably, the first conductor element serves as a transmitting coil and the second conductor element as a receiving coil. The conductor elements are preferably firmly connected to the conversion element. If the conversion element is damaged or broken, the conductor elements connected to it are also damaged, which leads to a change in the coil inductance. With this embodiment, the reliability with which an impairment of the conversion element or the conductor structure can be detected can be increased.

It is preferred that at least one conductor element, in particular the entire conductor structure, is transparent. Thus, the light path is influenced by the conductor structure as little as possible, so that a smaller dimension of the conversion element is needed. Thus, the size of the conversion element can be further reduced.

It is preferred that the conductor structure is connected to a heat sink in order to allow a warming of the conversion element. The conversion element may be arranged on a substrate which forms a heat sink. In this case, the conductor structure may also be connected to the substrate. With an additional heat sink, the cooling of the conversion element can be further improved.

It is preferred that the conversion element has a conversion element thickness, wherein preferably the conversion element thickness is substantially constant over the conversion element, wherein the conversion element thickness, in particular in a cross section, is reduced as a function of the conductor structure in order to allow a substantially constant overall height of the light conversion device , With this embodiment, the conductor structure is at least partially embedded in the conversion element. Thus, the contact is increased, whereby the heat dissipation can be further improved.

It is preferred that the conversion element has a conversion element thickness, wherein the conversion element thickness increases steadily starting from an edge region of the conversion element towards a middle region of the conversion element. If the conversion element is made thinner toward the edge, the light-emitting surface or the light-emitting volume can be visibly reduced. Thus, the heat input, especially at the edge, can be further reduced. The cooling is thus further facilitated.

Preferably, the light conversion device comprises an evaluation device which can be connected to the conductor structure, wherein the evaluation device is designed to detect the impedance and / or the ohmic resistance and / or the capacitance and / or the inductance of the conductor structure, based on the detected impedance and / or capacitance / or inductance to determine damage to the conversion element and / or the conductor structure. The evaluation device can determine the impedance or the resistance of the conductor structure at regular intervals and optionally store it in a memory device. By a continuous or temporal evaluation of the detected measured values, the evaluation device can determine whether an impairment of the conductor structure and / or the conversion element is present.

It is preferred that the conductor structure comprises a conductor element with a plurality of interconnected conductor segments, wherein at least one conductor segment extends at a distance from the edge of the conversion element along an edge region of the conversion element, in particular on the first and / or second broad side.

It is preferred that the conductor structure comprises a conductor element having a plurality of interconnected conductor segments, wherein at least one conductor segment extends from an edge region of the conversion element to an opposite edge region of the conversion element. Preferably, the conductor segments run meandering over at least one of the broad sides.

It is preferred that the conductor structure comprises a conductor element having a plurality of interconnected conductor segments, wherein a conductor segment forms a sheet conductor segment, which extends along the circumferential direction of the conversion element and in particular is formed in a circular arc.

It is preferred that the conductor structure comprises a conductor element with a plurality of interconnected conductor segments, wherein at least one other conductor segment forms a radial conductor segment which runs along a radial direction of the conversion element.

It is preferred that the conductor structure comprises a conductor element with a plurality of interconnected conductor segments, wherein at least one conductor segment forms a middle region segment, of which in particular the radial conductor segments preferably extend to the arc conductor segment, wherein in particular the middle region segment has an opening and in particular is of annular design ,

It is also conceivable that the at least one conductor structure at least partially or completely form a cooking curve and / or at least partially or completely in the form of a Sierpinski triangle and / or at least partially or completely in the form of a Mandelbrot set. This has the advantage that the phosphor is covered over the largest possible area of the line track in predetermined areas.

The invention further provides a lighting device, in particular for a motor vehicle, for generating an illumination light beam, having a laser device which is designed to emit a laser light beam; and a previously described light conversion device (LARP = laser activated remote phosphor arrangement), wherein the laser light beam can be fed into the light conversion device as a primary beam such that the illumination beam can be generated based on the secondary light beam generated by the light conversion device.

The vehicle equipped with the lighting device according to the invention may be an aircraft or a water-bound vehicle or a land-bound vehicle. The land-based vehicle may be a motor vehicle or a rail vehicle or a bicycle. Particularly preferably, the vehicle is a truck or a passenger car or a motorcycle. The vehicle may further be configured as a non-autonomous or partially autonomous or autonomous vehicle.

• - Bereitstellen eines Konversionselements, das ausgebildet ist, einen Primärlichtstrahl, der eine Primärwellenlänge aufweist, in einen Sekundärlichtstrahl zu konvertieren, der eine von der Primärwellenlänge verschiedene Sekundärwellenlänge aufweist;
• - Erzeugen einer elektrisch leitfähigen Leiterstruktur, die wenigstens ein Leiterelement umfasst, wobei das Leiterelement, vorzugsweise volumenmäßig und/oder flächenmäßig, wenigstens teilweise innerhalb des Konversionselements oder auf wenigstens einer Seite des Konversionselements an einer Oberfläche des Konversionselements erzeugt wird.

The invention further provides a method for producing a previously described light conversion device with the steps:

• Providing a conversion element configured to convert a primary light beam having a primary wavelength into a secondary light beam having a secondary wavelength different from the primary wavelength;
• - Producing an electrically conductive conductor structure comprising at least one conductor element, wherein the conductor element, preferably in terms of volume and / or surface, is generated at least partially within the conversion element or on at least one side of the conversion element on a surface of the conversion element.

The advantages and effects stated for the light conversion device according to the invention apply equally to the lighting device equipped with the light conversion device and to the method and vice versa. Accordingly, for device features also process features or vice versa can be formulated.

Further advantages, effects and features will become apparent from the following embodiment with reference to the accompanying figures. In the figures, like reference numerals designate like features and functions.

• 1 in einer schematischen Ansicht ein Ausführungsbeispiel einer Leuchtvorrichtung;
• 2 in einer schematischen Draufsicht ein erstes Ausführungsbeispiel einer Lichtkonversionseinrichtung;
• 3 eine Schnittansicht entlang III-III aus 2;
• 4 in einer schematischen Draufsicht ein zweites Ausführungsbeispiel einer Lichtkonversionseinrichtung;
• 5 eine Schnittansicht entlang V-V aus 4;
• 6 in einer schematischen Perspektivansicht ein drittes Ausführungsbeispiel einer Lichtkonversionseinrichtung;
• 7 eine Draufsicht der Lichtkonversionseinrichtung aus 6;
• 8 eine Schnittansicht entlang VIII-VIII aus 7;
• 9 eine Variante der Schnittgeometrie aus 8;
• 10 in einer schematischen Perspektivansicht ein viertes Ausführungsbeispiel einer Lichtkonversionseinrichtung;
• 11 in einer schematischen Perspektivansicht ein fünftes Ausführungsbeispiel einer Lichtkonversionseinrichtung;
• 12 in einer schematischen Ansicht die Funktionsweise einer Lichtkonversionseinrichtung;
• 13 in einer schematischen Seitenansicht ein sechstes Ausführungsbeispiel einer Lichtkonversionseinrichtung; und
• 14 in einer schematischen Seitenansicht die Funktionsweise einer Lichtkonversionseinrichtung.

Show it:

• 1 in a schematic view an embodiment of a lighting device;
• 2 in a schematic plan view, a first embodiment of a light conversion device;
• 3 a sectional view along III-III out 2 ;
• 4 in a schematic plan view, a second embodiment of a light conversion device;
• 5 a sectional view along VV out 4 ;
• 6 in a schematic perspective view of a third embodiment of a light conversion device;
• 7 a top view of the light conversion device 6 ;
• 8th a sectional view along VIII-VIII out 7 ;
• 9 a variant of the cutting geometry 8th ;
• 10 in a schematic perspective view of a fourth embodiment of a light conversion device;
• 11 in a schematic perspective view of a fifth embodiment of a light conversion device;
• 12 in a schematic view, the operation of a light conversion device;
• 13 in a schematic side view of a sixth embodiment of a light conversion device; and
• 14 in a schematic side view of the operation of a light conversion device.

It will open 1 Reference is made to an embodiment of a lighting device 10 shows. The lighting device 10 includes a laser light source 12 , which has a narrowband blue primary beam 14 towards a light conversion device 16 radiates. The light conversion device 16 converts the primary light beam 14 partly in a yellow secondary light beam 18 , The primary light beam 16 and the secondary light beam 18 result in superposition white useful light, that of the lighting device 10 is emitted for illumination. Furthermore, the lighting device comprises 10 a control device 20 as well as an evaluation device 106 , which is designed to detect measurement data and / or the laser light source 12 to control. The evaluation device 106 is designed to measure electrical resistance measurements and electrical resistance changes and / or to measure electromagnetically induced induction voltages and changes in this induction voltage and / or to measure, store and evaluate an electrical capacitance and a change in this capacitance. The method of induction monitoring is in US 2016290856 A1 is described in full and for the descriptions of the following embodiments with. The method of capacitive monitoring is in the application DE 10 2017 204 867.0 is described in full and for the descriptions of the following embodiments with. In particular, the evaluation device 106 adapted for, in the presence of a above-described resistive and / or inductive and / or capacitive change, which is greater than a respective threshold value, the laser light source 12 to dim or completely switch off. A measuring method and a suitable circuit device is in the German application EN 10 2016 115 493.8 is described in full and for the descriptions of the following embodiments with. This is a security of the lighting device 10 elevated.

A first embodiment of the light conversion device 16 is in 2 and 3 shown in more detail. The light conversion device 16 includes a substrate 22 , The substrate 22 For example, it is made of sapphire and can be used as a heat sink 23 serve. On the substrate 22 is a conversion element 24 arranged such that the conversion element 24 can be irradiated. The light conversion device 16 is operated in transmission (see 1 ). Between substrate 22 and conversion element 24 a dichroic filter layer (not shown) may be provided which allows incoming primary light to pass through and from the conversion element 24 reflected in the direction of the primary light source backscattered conversion light, so that it conversion light from the conversion element 24 can emerge in the radiation direction. The conversion element, also referred to as a converter 24 preferably comprises a phosphor material which is known per se.

The conversion element 24 is in this example as a plate element 26 formed, which has a substantially square shape. The conversion element 24 has a substantially constant conversion element thickness d between 50 .mu.m and 1000 .mu.m, here preferably of 200 .mu.m. The conversion element 24 has a first broadside 28 (above) and a second broadside 30 (bottom), which face each other in the transmission direction. Furthermore, the conversion element comprises 24 a plurality of side areas 32 that come together with a narrow section of the respective broadsides 28 . 30 a border area 34 form. More specifically, the border area includes 34 up to about 10% of the dimension of each broadside 28 . 30 starting from the page area 32 along the surface of each broadside 28 . 30 ,

The light conversion device 16 further comprises an electrically conductive conductor structure 36 , The ladder structure 36 is on the conversion element 24 applied. In this example, the ladder structure is 36 at the edge area 34 and on the surface of the first broadside 28 intended.

The ladder structure 36 includes a first conductor element 38 and a second conductor element 40 , The first conductor element 38 includes a plurality of interconnected conductor segments 42 (here: four), on the side area 32 and partly on the surface of the first broadside 28 along the circumferential direction of the conversion element 24 are applied. In other words, the first conductor element 38 along the edge area 34 arranged. Preferably, the first conductor element 38 Metallic running to the side area 32 otherwise escaping light back into the conversion element 24 to reflect back.

The second conductor element 40 includes a plurality of interconnected conductor segments 44 (here: five) on the surface of the first broadside 28 and at a distance from the edge area 34 are arranged. The conductor segments 44 are arranged so that the second conductor element 40 is meander-shaped. The conductor segments run thereby 44 each alternating once along the edge area 34 and once between opposite sections 46 . 48 of the border area 34 , Free ends 50 . 52 of the conductor element 40 can as connections 54 for the control device 20 serve, which will be described in more detail. The conductor segments 44 are made of a thin gold coating. The width of the conductor segments 44 is preferably between about 5 microns and 1000 microns, preferably 10 microns. The width of the conductor segments 44 may be along the length of individual, some or all conductor segments 44 vary. The conductor segments 44 are fixed to the conversion element 24 connected.

In one embodiment, not shown, can also on the second broadside 30 (Bottom) the electrically conductive conductor structure 36 to be appropriate. With this double arrangement can be resistive and / or inductive and / or capacitive measurements to monitor the integrity of the conversion element 24 carry out. Collectively, resistive and / or inductive and / or capacitive measurements are also referred to as impedance measurements. In an inductive measurement that serves on the one hand (for example, the first broadside 28 ) mounted electrically conductive conductor structure 36 as a transmitting coil and on the other side (for example, the second broadside 30 ) mounted electrically conductive conductor structure 36 as a receiving coil.

4 and 5 show a second embodiment of a light conversion device 56 compared to the light conversion device 16 another embodiment of a second conductor element 58 and otherwise identical. The second conductor element 58 includes a plurality of interconnected conductor segments 60 (here: five), which are at a distance from the edge area 34 along the circumferential direction of the conversion element 24 run. As previously described, the width of the conductor segments 60 vary accordingly. The second conductor element 58 also provides free ends 62 . 64 as connections 66 to disposal.

It will be following on the 6 to 8th Reference is made to the third embodiment of a light conversion device 68 demonstrate. The light conversion device 68 includes a substrate 70 , The substrate 70 For example, it is made of sapphire and can be used as a heat sink 71 serve. On the substrate 70 is a conversion element 72 arranged such that the conversion element 72 can be irradiated. The conversion element 72 preferably comprises a phosphor material which is known per se.

The conversion element 72 is as a plate element 74 formed, which has a substantially circular shape. The conversion element 72 here has a substantially constant conversion element thickness d of 200 μm. The conversion element 72 has a first broadside 76 (above) and a second broadside 78 (bottom), which face each other in the transmission direction. Furthermore, the conversion element comprises 72 a page area 80 That together with a narrow section of the respective broadsides 76 . 78 a border area 82 forms. More specifically, the border area includes 82 up to about 10% of the dimension of each broadside 76 . 78 starting from the page area 80 along the surface of each broadside 76 . 78 ,

The light conversion device 68 further comprises an electrically conductive conductor structure 84 , The ladder structure 84 is partially in the conversion element 72 embedded. The ladder structure 84 is here preferably formed in the form of thin aluminum webs. Also conceivable is a design as silver bars, gold bars or copper bars. The ladder structure 84 is at a distance from the edge area 82 , on the surface of the first broadside 76 and on a surface of the substrate 70 intended.

The ladder structure 84 includes a conductor element 86 comprising a plurality of interconnected conductor segments 87 partially at the edge area 82 and partly on the surface of the first broadside 28 are applied.

Two conductor segments extend at a distance from the edge region 82 essentially circular arc-shaped along the circumferential direction of the conversion element 72 and each form a sheet conductor segment 88 ,

In the center of the conversion element 72 For example, a conductor segment may be arranged that is essentially circular and has a middle region segment 90 forms.

Between the mid-range segment 90 and each arc conductor segment 88 may be arranged a plurality of radially extending conductor segments, which the sheet conductor segment 88 with the mid-range segment 90 connect electrically. These conductor segments form radial conductor segments 92 , The Radial conductor segments 92 extend spokes between the mid-range segment 90 and the arc conductor segment 88 ,

In addition, two further conductor segments can be used as connections 94 be present at the edge area 82 and on the substrate 70 are arranged.

As in 8th shown, the conversion element 72 considered in cross-section only at those points where the conductor structure 84 is arranged, a reduced conversion element thickness d on. Consequently, one is from the edge area 82 to the center of the conversion element 72 towards increasing share of the ladder structure 84 in the conversion element 72 embedded. Thus, the embedding of the conductor structure 84 at the location of the greatest irradiation of primary light also largest, whereby the heat dissipation can be improved.

In a variant of this embodiment, not shown, at least one conductor element 86 in the conversion element 72 protrude. The conductor element 86 is so to speak partially embedded or buried and protrudes only partially from the conversion element 72 out. This is also referred to as surface embedding. The width of the conductor segments 87 is preferably 10 microns. The width of the conductor segments 87 may be along the length of individual, some or all conductor segments 87 vary. Preferably, the conductor segments 87 designed in this variant as silver bars. The conductor segments 87 have in particular a rectangular cross-sectional profile, but may also be designed triangular, trapezoidal or freeform.

In a variant not shown here, the conversion element thickness d not only at the points of the ladder structure 84 but generally be configured in the manner described above.

9 shows a variant in which the conductor structure 84 always on the surface of the conversion element 72 is applied. In other words, in this example, no part of the ladder structure 84 in the conversion element 72 embedded.

According to 10 is a fourth embodiment of a light conversion device 96 similar to the light conversion device 68 educated. However, by contrast, it is a mid-range segment 98 circular with an opening 100 educated. In this configuration, the conductor structure may also be formed metallic and opaque.

How out 11 can be seen, a fifth embodiment of a light conversion device 102 additionally a plurality of conductor segments 104 in the ladder structure 84 on, where the conductor segments 104 at the edge area 82 are arranged. The conductor segments are preferred 104 metallic reflective formed to the side area 80 otherwise escaping light back into the conversion element 72 to reflect.

Based on 12 the operation of the invention will be explained in more detail. The control device 20 includes an evaluation device 106 , which is designed to detect, store and evaluate an ohmic resistance. The evaluation device 106 is to the ladder structure 84 (or other conductor structure described herein) and measures intermittently or continuously the ohmic resistance of the conductor pattern 84 , Preferably, the acquired measured values are stored.

Occurs damage 108 a, which may arise for example by thermal or mechanical action and reduces or breaks one of the conductor segments, such as one of the radial conductor segments 92 , so the ohmic resistance of the entire conductor structure changes 84 , This change in the ohmic resistance is provided by the evaluation device 106 recognized. The control device 20 can harm a user on the damage 108 point out and possibly also initiate countermeasures, for example, the power of the laser light source 12 regulate accordingly, for example, to dim or completely off. Furthermore, the evaluation device 106 be configured to measure electromagnetically induced induction voltages and changes in this induction voltage and / or to measure, store and evaluate an electrical capacitance and a change in this capacity.

In 13 and 14 is a sixth embodiment of a light conversion device 110 shown. In contrast to the previously described light conversion devices, the light conversion device comprises 110 for example, the conversion element described above 72 on the but a ladder structure 112 on both broadsides 76 . 78 is arranged. The conversion element 72 thus forms a dielectric 113 and along with the ladder structure 112 a capacitor arrangement 114 , The ladder structure 112 can have any meaningful combination of the previously described conductor elements.

If, as in this embodiment, the electrically conductive conductor pattern 112 also on the second broadside 78 (Bottom) the conductor elements 86 with conductor segments 87 includes, they may be the same or else be attached with a different geometric arrangement. With such double arrangements can be resistive and / or inductive and / or capacitive measurements (such as in the capacitor arrangement 114 ) for monitoring the integrity of the conversion element 72 carry out. Collectively, resistive and / or inductive and / or capacitive measurements are also referred to as impedance measurements. In this example, the conductor segments 87 preferably formed as a thin silver ribs, which on the surface of the conversion element 72 attached or firmly glued to it by means of a glass solder.

In a further embodiment, the conductor elements 86 or the conductor segments 87 be formed of an optically transparent ITO coating (indium tin oxide layer), which is both optically transparent and electrically and thermally conductive. Again, on the second broadside 78 (Bottom) a similar or a non-similar electrically conductive conductor structure 112 (ITO layer) with conductor segments 87 to be appropriate. As described above, such double arrangements permit resistive and / or inductive and / or capacitive measurements for monitoring the integrity of the conversion element 72 carry out. In an inductive measurement serves the mounted on one side conductor element 86 as a transmitting coil and the attached on the other side conductor element 86 as a receiving coil.

Based on 14 the functionality is explained in more detail. The evaluation device 106 is in this case additionally designed such that an impedance of the conductor structure 112 can be determined. Occurs damage 116 the conversion element 72 and / or the ladder structure 112 on, the capacitance of the capacitor arrangement changes 114 , This changes the impedance of the capacitor arrangement 114 , The change in the impedance can in turn by the evaluation 106 be recorded. Subsequently, a user can be informed or, if necessary, countermeasures initiated. Advantage of this configuration is that not only damage to the conductor structure 112 can be measured directly, but also the damage of the conversion element 72 ,

Finally, a method for producing a light conversion device described above will be described. The manufacturing steps are as follows:

First, a conversion element (converter) is applied to a substrate (e.g., sapphire), for example by adhering the conversion element to the substrate with a low melting glass solder.

Preferably, by means of a photolithographic mask, a metallization is carried out, so that the edge region of the converter is bordered by metal. In the same manufacturing step or separately, a metallic conductor structure (for example, round, rectangular, meander-shaped) can also be applied. The ladder structure is also known as the SRS structure (Safety Recognition Structure). Other metallization methods are conceivable, even if they can be more expensive.

Alternatively, the conductor structure can also be made of a transparent material and / or applied in a separate production step.

In the exemplary embodiments, special cases are described for the purpose of illustration. The SRS structures can also be attached simultaneously on both sides. The structure can also - at least partially - be embedded in the phosphor of the conversion element.

In the application, the structure is irradiated from the bottom with a concentrated laser beam (transmission arrangement). A reflection arrangement is also possible. For this purpose, at the bottom of the converter is preferably a reflective surface, which may alternatively be spaced from the converter.

Ideas were presented which fulfill the above-mentioned requirements a) to d) as comprehensively as possible. However, not all benefits must be present or satisfied in all embodiments. In particular, particularly suitable geometries for the conductive structures (conductor structures) of a resistive or capacitive or inductive safety concept are shown, which simultaneously serve for heat dissipation of the converter.

With the described embodiments, it is possible to meet the requirements simultaneously and more effectively.

Thus, the converter can be made small and limited in space due to better cooling, whereby leaking, yellowish-emitting edges on the light-emitting surface can be avoided.

Furthermore, the light which emerges laterally from the converter can be reflected back by the preferably circulating, reflective metallization layer, so that the optical efficiency can be improved.

In addition, the SRS structure provides a safety mechanism that counteracts overheating of the converter, such as the peripheral metal surround of the converter and the SRS structure.

The SRS structure is electrically conductive. Damage to the converter, and thus the SRS structure, usually leads to a change in the conductance of the SRS structure, which can be detected by evaluation electronics.

With the SRS structure mounted on either side of the converter, it forms a capacitor array along with the converter as a dielectric. In this case, damage to the SRS structure or the converter can additionally lead to a change in capacity, which can also be detected with the transmitter.

If the SRS structure is mounted on both sides of the converter, one side can act as an electromagnetic transmitting coil and the other side as an electromagnetic receiving coil. In this case, damage to the SRS structure or the converter can lead to an inductance change, which can also be detected with the transmitter.

LIST OF REFERENCE NUMBERS

10

lighting device

12

Laser light source

14

Primary light beam

16

Light conversion device

18

Secondary beam

20

control device

22

substratum

23

heat sink

24

conversion element

26

panel member

28

first broadside

30

second broadside

32

page range

34

border area

36

conductor structure

38

first conductor element

40

second conductor element

42

conductor segment

44

conductor segment

46

opposite section

48

opposite section

50

free end

52

free end

54

connections

56

Light conversion device

58

second conductor element

60

conductor segment

62

free end

64

free end

66

connections

68

Light conversion device

70

substratum

71

heat sink

72

conversion element

74

panel member

76

first broadside

78

second broadside

80

page range

82

border area

84

conductor structure

86

conductor element

87

conductor segment

88

Arch conductor segment

90

Mid-range segment

92

Radial conductor segment

94

connections

96

Light conversion device

98

Mid-range segment

100

opening

102

Light conversion device

104

conductor segment

106

evaluation

108

damage

110

Light conversion device

112

conductor structure

113

dielectric

114

capacitor arrangement

116

damage

d

Conversion element thickness

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 2016290856 A1 [0039]
• DE 102017204867 [0039]
• DE 102016115493 [0039]

Claims (11)

Light conversion device (16, 56, 68, 96, 102, 110) for a lighting device (10), comprising: - a conversion element (24, 72), which is formed, a primary light beam (14) having a primary wavelength, at least partially in converting a secondary light beam (18) having a different secondary wavelength from the primary wavelength, characterized by an electrically conductive conductor structure (36, 84, 112) comprising at least one conductor element (38, 40, 58, 86), wherein the conductor element ( 38, 40, 58, 86), - preferably in terms of volume and / or surface, at least partially within the conversion element (24, 72) and / or - on at least one side of the conversion element (24, 72) is arranged on a surface of the conversion element. Light conversion device (16, 56, 68, 96, 102, 110) after Claim 1 , characterized in that the conversion element (24, 72) substantially as a plate member (26, 74) with a first broad side (28, 76), a second broad side (30, 78) and an edge region (34, 82) is formed, wherein the conductor element (38, 40, 58, 86) is arranged on the surface of at least one of the broad sides (28, 30, 76, 82) and / or wherein the conductor element (38, 40, 58, 86) is arranged on one of the broad sides ( 28, 30, 76, 82) and at least partially on the edge region (34, 82) is arranged. Light conversion device (110) after Claim 2 , characterized in that the conductor structure (112) comprises a first conductor element and a second conductor element, wherein the first conductor element on the first broad side (76) and the second conductor element on the second broad side (78) are arranged, so that the conversion element (72 ) forms a dielectric (113) of a capacitor arrangement (114) formed from the conductor elements and / or that the conductor structure (112) comprises a first conductor element and a second conductor element, wherein the first conductor element on the first broad side (76) and the second conductor element the second broad side (78) are arranged, so that the conversion element (72) forms a coil core element of a coil arrangement formed from the conductor elements. Light conversion device (16, 56, 68, 96, 102, 110) according to one of Claims 1 to 3 , characterized in that at least one conductor element (38, 40, 58, 86), in particular the entire conductor structure (36, 84, 112), is transparent. Light conversion device (16, 56, 68, 96, 102, 110) according to one of Claims 1 to 4 , characterized in that the conductor pattern (36, 84, 112) is connected to a heat sink (23, 71) in order to allow a warming of the conversion element (24, 72). Light conversion device (16, 56, 68, 96, 102, 110) according to one of Claims 1 to 5 , characterized in that the conversion element (24, 72) has a conversion element thickness (d), wherein the conversion element thickness (d) over the conversion element (24, 72) is substantially constant, viewed in a cross section, the conversion element thickness (d) in Dependence on the conductor pattern (36, 84, 112) is reduced to allow a substantially constant overall height of the light conversion means (16, 56, 68, 96, 102, 110). Light conversion device (16, 56, 68, 96, 102, 110) according to one of Claims 1 to 5 , characterized in that the conversion element (24, 72) has a conversion element thickness (d), wherein the conversion element thickness (d) starting from an edge region (34, 82) of the conversion element (24, 72) towards a central region of the conversion element (24, 72) is steadily increasing. Light conversion device (16, 56, 68, 96, 102, 110) according to one of Claims 1 to 7 , characterized by an evaluation device (106) which can be connected to the conductor structure (36, 84, 112), wherein the evaluation device (106) detects the impedance and / or the ohmic resistance and / or the capacitance and / or the inductance of the conductor structure (36 , 84, 112) to detect damage to the conversion element (24, 72) and / or the conductor structure (36, 84, 112) based on the detected impedance. Light conversion device (16, 56, 68, 96, 102, 110) according to one of Claims 1 to 7 characterized in that the conductor structure (36, 84, 112) comprises a conductor element with a plurality of interconnected conductor segments, - wherein at least one conductor segment (42) at a distance from the edge region (34) of the conversion element (24) along an edge region ( 34) of the conversion element (24), in particular on the first and / or second broad side (28, 30); and / or - wherein at least one conductor segment (44) extends from an edge region (34) of the conversion element (24) to an opposite edge region (34) of the conversion element (24); and / or - wherein a conductor segment (87) forms a sheet conductor segment (88), which extends along the circumferential direction of the conversion element (72) and in particular is formed in a circular arc; and or - wherein at least one conductor segment (87) forms a radial conductor segment (92) extending along a radial direction of the conversion element (72); and / or - wherein at least one conductor segment (87) forms a central region segment (90), of which, in particular, the radial conductor segments (92) preferably extend to the arc conductor segment (88); and / or - wherein the middle region segment (98) has an opening (100) and in particular is of annular design. A lighting device (10) for a vehicle for generating an illumination light beam, comprising: - A laser light source (12) which is adapted to emit a laser light beam; and - A light conversion device (16, 56, 68, 96, 102, 110) according to any one of the preceding claims, wherein the laser light beam in the light conversion device (16, 56, 68, 96, 102, 110) as the primary beam (14) can be fed, in that the illumination beam can be generated on the basis of the secondary light beam (18) generated by means of the light conversion device (16, 56, 68, 96, 102, 110). Method for producing a light conversion device (16, 56, 68, 96, 102, 110) according to one of the preceding claims, characterized by the steps: - providing a conversion element (24, 72) which is designed to generate a primary light beam (14) a primary wavelength to convert to a secondary light beam (18) having a secondary wavelength different from the primary wavelength; - Producing an electrically conductive conductor structure (36, 84, 112) comprising at least one conductor element (38, 40, 58, 86), wherein the conductor element (38, 40, 58, 86), preferably in terms of volume and / or surface, at least is generated partially within the conversion element (24, 72) or on at least one side of the conversion element (24, 72) on a surface of the conversion element (24, 72).

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