WO2024083732A1

WO2024083732A1 - Lighting arrangement comprising a laser light source

Info

Publication number: WO2024083732A1
Application number: PCT/EP2023/078654
Authority: WO
Inventors: Rifat Ata Mustafa Hikmet; Gábor Toth; Jiang Hong YU; Ties Van Bommel; Olexandr Valentynovych VDOVIN
Original assignee: Signify Holding B.V.
Priority date: 2022-10-18
Filing date: 2023-10-16
Publication date: 2024-04-25

Abstract

A light generation system (100), comprising a laser light arrangement (110) comprising a laser light source (115) arranged to emit laser light (120) and an optical element configured to focus the emitted laser light, a heat sink (130) extending in a first plane, P1, a structure (140) extending in a second plane, P2, parallel to the first plane, P1, wherein the structure is arranged between the laser light arrangement and the heat sink, and is physically separated from the heat sink by a gap (150), the structure comprising a light converting element (160) with a focal area, AL, arranged to receive the focused emitted laser light, and a support element (170) arranged to support the light converting element, and a movement mechanism (200) configured to move the structure in the second plane, P2, between the laser light source arrangement and the heat sink.

Description

Lighting arrangement comprising a laser light source

FIELD OF THE INVENTION

The present invention generally relates to a lighting arrangement comprising a laser light source. More specifically, the present invention is related to a lighting arrangement comprising a laser light source and an element arranged to receive the emitted laser light for absorption and laser light conversion.

BACKGROUND OF THE INVENTION

Laser-based light sources are gathering much interest due to their potential in producing extremely high intensities. By focusing laser light to a relatively small area, a high intensity light source can be achieved. However, one of the factors which limits the obtaining of higher intensities is the temperature of elements arranged to receive the emitted laser light for absorption and laser light conversion. Hence, thermal management solutions are required in order to prevent thermal damage, and it is necessary to dissipate excess heat in order to maintain the reliability of the lighting arrangements of this kind and to prevent premature failure thereof.

However, current thermal management applications of laser-based lighting arrangements may be insufficient and/or inadequate. For example, heat management units and/or profiles may be based on worst case scenarios, which may lead to over-dimensioning of heat sink applications. Consequently, this may lead to (a) big and bulky heat sink(s) and/or larger costs associated with these heat sink(s).

Hence, it is an object of the present invention to try to overcome at least some of the drawbacks of present heat management applications, and to provide laser-based lighting arrangements in which the components thereof are not subjected to damage, or at least in which damage is mitigated, due to high temperatures.

SUMMARY OF THE INVENTION

Hence, it is of interest to overcome at least some of the deficiencies of heat management applications according to present technologies, and to provide a laser-based lighting arrangement which achieves a mitigation of component damage due to high temperatures.

This and other objects are achieved by providing a light generation system having the features in the independent claims. Preferred embodiments are defined in the dependent claims.

Hence, according to a first aspect of the present invention, there is provided a light generation system. The light generation system comprises a laser light arrangement comprising a laser light source arranged to emit laser light, and an optical element configured to focus the emitted laser light. The light generation system further comprises a heat sink extending in a first plane, Pi, and a structure extending in a second plane, P2, parallel to the first plane, Pi, wherein the structure is arranged between the laser light arrangement and the heat sink, and is physically separated from the heat sink by a gap. The structure comprises a light converting element configured to at least partially convert laser light into converted light, wherein the light converting element has a focal area, AL, arranged to receive the focused emitted laser light. The structure further comprises a support element arranged to support the light converting element and at least partially facing the heat sink, wherein the support element is arranged in thermal contact with the light converting element and the heat sink, and is arranged to spread heat from the light converting element to the heat sink. The light generation system further comprises a movement mechanism configured to move the structure in the second plane, P2, between the laser light source arrangement and the heat sink, such that the focused emitted laser light, incident on any first sub-area, Ai,j, of the focal area, AL, subsequently becomes incident on any second sub-area, Ak,i, of the focal area, AL, different from the first sub-area, Aij.

According to a second aspect of the present invention, there is provided a method for light generation via a light generation system. The light generation system comprises a laser light arrangement comprising a laser light source arranged to emit laser light, and an optical element configured to focus the emitted laser light. The light generation system further comprises a heat sink extending in a first plane, Pi, and a structure extending in a second plane, P2, parallel to the first plane, Pi, wherein the structure is arranged between the laser light source and the heat sink, and is physically separated from the heat sink by a gap. The structure comprises a light converting element configured to at least partially convert laser light into converted light, wherein the light converting element has a focal area, AL, arranged to receive the focused emitted laser light. The structure further comprises a support element arranged to support the light converting element and at least partially facing the heat sink, wherein the support element is in thermal contact with the light converting element and the heat sink, and is arranged to spread heat from the light converting element to the heat sink. The method comprises the step of moving the structure in the second plane, P2, between the laser light source arrangement and the heat sink, such that the focused emitted laser light, incident on any first sub-area, Aij, of the focal area, AL, subsequently becomes incident on any second sub-area, Ak,i, different from the first sub-area, Ai,j.

Thus, the present invention is based on the idea of providing a light generation system, wherein a structure comprising a light converting element for laser light conversion is moved by a movement mechanism to change the (sub-) areas of the light converting element subjected to the focused emitted laser light during operation whilst providing heat dissipation.

The present invention is advantageous in that light converting element is conveniently and efficiently moved by the movement mechanism in order to change the (sub-) areas of the light converting element which are subjected to the focused emitted laser light during operation of the light generation system. Consequently, detrimental effects as a result of focusing laser light to a relatively small area of the light converting element and/or during a relatively long time may be avoided, and the effective surface area of the light converting element is increased.

The present invention is further advantageous in that the light generation system is able to efficiently dissipate heat from the light converting element during operation of the system. More specifically, as the support element is in thermal contact with the light converting element and the heat sink, and is arranged to spread heat from the light converting element to the heat sink, the system achieves an effective thermal heat management during operation of the light generation system. In addition, the elongated form of the support element and the heat sink allows for an optimal thermal heat management of the light converting element.

The light generation system according to the first aspect of the present invention comprises a laser light arrangement comprising a laser light source arranged to emit laser light. By “laser light source”, it is here meant one or more light sources arranged or configured to emit laser light. The laser light arrangement further comprises an optical element configured to focus the emitted laser light. By “optical element”, it is here meant substantially any element, device or unit which is configured or arranged to focus the laser light as emitted from the laser light source. The light generation system further comprises a heat sink extending in a first plane, Pi. By “heat sink”, it is here meant substantially any element, structure or component arranged or configured to dissipate heat. The light generation system further comprises a structure extending in a second plane, P2, parallel to the first plane, Pi. Hence, the structure and the heat sink are arranged (extend) in parallel. The structure is arranged between the laser light arrangement and the heat sink, and is physically separated from the heat sink by a gap. Hence, the structure and the heat sink, which are arranged (extend) in parallel, are separated by a gap (distance). The structure comprises a light converting element configured to at least partially convert laser light into converted light, wherein the light converting element has a focal area, AL, arranged to receive the focused emitted laser light. Hence, the laser light arrangement is configured to focus the emitted laser light onto the focal area, AL, of the light converting element. In other words, the focal area, AL, is the area where the emitted laser light rays meet. It will be appreciated that the focal area, AL, also represents a scanning area of the laser light arrangement. By “scanning area”, it is here meant the area which the laser light arrangement is arranged to pass the emitted laser light rays over. The structure further comprises a support element arranged to support the light converting element which at least partially faces the heat sink. By “support element”, it is here meant any kind of element configured or arranged to support the light converting element, such as a (heatspreading) substrate, or the like. The support element is arranged in thermal contact with the light converting element and the heat sink, and is arranged to spread heat from the light converting element to the heat sink. For example, the support element and the light converting element may be in direct physical contact. The light generation system further comprises a movement mechanism configured to move the structure in the second plane, P2, between the laser light source arrangement and the heat sink. By “movement mechanism” it is here meant substantially any mechanism, actuator, arrangement, or the like, which is configured to move an element, unit, arrangement, or the like, coupled or connected thereto. The movement mechanism is hereby configured to move the structure parallel to the (elongation of the) heat sink. The movement mechanism is configured to move the structure such that the focused emitted laser light, incident on any first sub-area, Aij, of the focal area, AL, subsequently becomes incident on any second sub-area, Ak,i, of the focal area, AL, different from the first sub-area, Aij. Hence, the movement mechanism is configured to move the structure such that any first sub-area, Ai , of the focal area, AL, is (first) subjected to the focused emitted laser light, and that any second sub-area, Ak,i, of the focal area, AL, thereafter becomes subjected to the focused emitted laser light. It should be noted that any first sub-area, Aij, of the focal area, AL, and any second sub-area, Ak,i, of the focal area, AL, may be discrete (i.e. separate or distinct from each other). Alternatively, any first sub-area, Aij, and any second sub-area, Ak,i, may partly overlap. By the wording ”sub-area of the focal area”, it is here meant a focused laser light spot on the light converting element, i.e. the portion (spot) of the focal area subjected to the focused laser light.

According to an embodiment of the present invention, the focal area, AL, comprises a predetermined apportionment of sub-areas, A_m,n, of the focal area, AL. Hence, this may be an apportionment or division of the focal area, AL, into a predetermined number and/or arrangement of sub-areas, A_m,n, for the focused emitted laser light. For example, the predetermined apportionment of sub-areas, Am,n, may constitute a matrix or grid. The present embodiment is advantageous in that the movement mechanism may be configured to move the structure such that the focused emitted laser light becomes incident on the focal area, AL, of the light converting element according to the predetermined apportionment of sub-areas, Am,n, thereby obtaining an even larger degree of control of the operation of the light generation system.

The movement mechanism may be configured to move the structure via one of rotation and oscillation. Moving the structure via one of rotation and oscillation in the context of this invention needs to be understood as a repetitive or periodic movement between two or more different states. Thus, a movement back and forth in a regular rhythm. Hence, the movement mechanism may be configured to either move the structure periodically via rotation (in the second plane, P2) or periodically via oscillation (in the second plane, P2). The present embodiment is advantageous in that the movement mechanism, via the rotation or oscillation, achieves an efficient periodic movement of the structure.

According to an embodiment of the present invention, a relation between an area, AT, of a sub-area, Aij, of the focal area, AL, and the focal area, AL, fulfills 2- AT < AL < 8-AT. Hence, as the movement mechanism moves the structure during operation, the emitted laser light becomes incident on an area, AT, of the focal (scanning) area, AL. The present embodiment is advantageous in that it is preferred that the focal area, AL, is at least twice as large as the area, AT, of the sub-area, Aij, to avoid quenching. The present embodiment is further advantageous in that it is preferred that the focal area, AL, is smaller than eight times the area, AT, of the sub-area, Aij, due to a limitation of size and/or weight of the light converting element 160 (and the structure) for a facilitated movement by the movement mechanism. The relation between the area, AT, of a sub-area, Aij, of the focal area, AL, and the focal area, AL, may even more preferred fulfill 3-AT < AL < 6- AT. According to an embodiment of the present invention, a relation between a top surface area, Ps, of the light converting element, and the focal area, AL, fulfills AL < Ps < 3-AL. The present embodiment is advantageous in that it is preferred that the focal area, AL, is smaller than the area, Ps, of the top surface of the light converting element 160 for reasons of safety. The present embodiment is further advantageous in that it is preferred that the area, Ps, of the top surface of the light converting element 160 is smaller than three times the focal area, AL, due to a limitation of size and/or weight of the light converting element 160 (and the structure) for a facilitated movement by the movement mechanism.

The focal area, AL, may have at least one optical property being constant for the focal area, AL such that one or more properties of the converted light may be constant.

Optical property here is meant to include every property of the focal area, AL, influencing the conversion of the incident focused emitted laser light to the converted light. The optical properties may include for example the (phosphor) material of the light converting element, the structural build-up, the surface shape and structure, the light conversion, the reflectivity, or the transmissivity.

It will be appreciated that an optical property of the focal area, AL, being constant directly results in a property of the converted light being constant. A property of the converted light being constant may for example be a color point, a color temperature, a color rendering index, a light distribution or a beam shape of the converted light.

In an example, all optical properties may be constant for the focal area, AL, such that all properties of the converted light may be constant. In other words, the sub-area of the focal area, AL, on which the focused emitted laser light is incident changes due to movement of the structure. However, the properties of the converted light may essentially stay the same, resulting in the capability to keep constant and stable light output across the whole focal area, AL.

According to an embodiment of the present invention, the support element may comprise a magnetic material. The present embodiment is advantageous in that the support element, by the magnetic material, may achieve an efficient motion of the light converting structure it supports with respect to the heat sink.

According to an embodiment of the present invention, the movement mechanism may comprise at least one of a piezo actuator, a magnetic actuator, a linear motor and a rotational motor. The present embodiment is advantageous in that the mentioned devices and/or arrangements may achieve an efficiently motion of the structure with respect to the heat sink. According to an embodiment of the present invention, the structure may further comprise a reflective layer arranged between the light converting element and the support element.

According to an embodiment of the present invention, the gap may have a dimension, d, in a range from 1-50 pm, and wherein the gap is at least partially filled with a fluid.

According to an embodiment of the present invention, the support element may have a first volume, V i, and a first weight, Wi, and the heat sink may have a second volume, V2, and a second weight, W2, wherein at least one of Vi < O.OFV2, and Wi < 0.01 -W2, is fulfilled.

According to an embodiment of the present invention, the light converting element may comprise a ceramic phosphor layer. For example, the ceramic phosphor layer may comprise cerium, Ce, doped Yttrium Aluminum Garnet, YAG.

According to an example of the present invention, the laser light source may be arranged to emit blue laser light within a wavelength range of 400-490 nm.

According to an embodiment of the present invention, at least one of the features that material comprises copper, Cu, the length, 1, is 70-130 mm, the width, w, is 70- 130 mm, the thickness, t, is 1-5 mm, the weight is 55-95 g, is fulfilled for the heat sink.

According to an example of the present invention, there is provided a lighting device selected from the group consisting of a lamp, a luminaire, a projector device, a disinfection device, a photochemical reactor, and an optical wireless communication device, wherein the lighting device comprises the light generation system according to any one of the preceding claims, and a controller configured to control the movement mechanism. Hence, the lighting device may constitute any one of the mentioned devices or arrangements. By the term “controller”, it is here meant substantially any control unit, device, arrangement, or the like, which is arranged or configured to control the movement mechanism of the light generation system.

Further objectives of, features of, and advantages with, the present invention will become apparent when studying the following detailed disclosure, the drawings and the appended claims. Those skilled in the art will realize that different features of the present invention can be combined to create embodiments other than those described in the following.

BRIEF DESCRIPTION OF THE DRAWINGS This and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing embodiment(s) of the invention.

Fig. la schematically shows a light generation system according to an exemplifying embodiment of the present invention,

Fig. lb schematically shows a portion of a light generation system according to an exemplifying embodiment of the present invention,

Figs. 2, 3a, 3b and 4 schematically show a light generation system during operation according to exemplifying embodiments of the present invention, and

Fig. 5 schematically shows devices or arrangements comprising a light generation system according to an exemplifying embodiment of the present invention.

DETAILED DESCRIPTION

Fig. la schematically shows a light generation system 100 according to an exemplifying embodiment of the present invention. The light generation system 100, which may provide system light, comprises a laser light arrangement 110 comprising one or more laser light sources 115 arranged to emit laser light. For example, the laser light arrangement 110 may emit blue laser light within a wavelength range of 400-490 nm. The laser light arrangement 110 further comprises an optical element (not shown) which is configured to focus the emitted laser light. The light generation system 100 further comprises a heat sink 130 extending in a first plane, Pi. Here, the heat sink 130 is exemplified as a plate which elongates in the first plane, Pi. The light generation system 100 further comprises a structure 140 extending in a second plane, P2, parallel to the first plane, Pi. Here, the structure 140 is exemplified as having a form which elongates in the second plane, P2. Hence, the structure 140 and the heat sink 130 are arranged (extend) in parallel, and the structure 140 is arranged between the laser light arrangement 110 and the heat sink 130.

Fig. lb schematically shows a portion of the light generation system 100 according to an exemplifying embodiment of the present invention. Fig. lb represents a zoomed-in view of Fig. la, and it is referred to Fig. la and the associated text for an increased understanding. According to Fig. lb, the structure 140, which is indicated by the dashed rectangle, is physically separated from the heat sink 130 by a gap 150. The gap 150 may have a length dimension, d, perpendicular to the first plane, Pi, and the second plane, P2, which is in a range from 1-500 pm, preferably 1-250 pm, even more preferred 1-100 pm, and most preferred 1-50 pm. The gap 150 may be at least partially filled with a fluid. The structure 140 comprises a light converting element 160 which is configured to at least partially convert laser light into converted light 165. The converted light 165 may be white light, preferably having a correlated color temperature, CCT, in a range from 2000 to 6500 K, and typically with a color rendering index, CRI, of at least 80, preferably > 85.

The light converting element 160, which may have the form of a tile, a plate, or the like, may comprise a ceramic phosphor layer. Furthermore, the ceramic phosphor layer comprises cerium, Ce, doped Yttrium Aluminum Garnet, YAG. The dimensions of the light converting element 160 may comprise a length of 3-30 mm, more preferred 4-20 mm, and most preferred 5-10 mm, a width of 1-10 mm, more preferred 2-7 mm, and most preferred 3- 5 mm, and a thickness of < 1 mm, whereby the shape of the light converting element 160 is preferably elongated. For example, the dimensions of the light converting element 160 may be 4 x 4 x 0.2 mm.

The light converting element 160 has a focal area, AL, arranged to receive the focused emitted laser light from the laser light source(s) of the laser light arrangement. The structure 140 further comprises a support element 170 arranged to support the light converting element 160. Optionally (not shown), the structure 140 may comprise a reflective layer arranged between the light converting element 160 and the support element 170. Furthermore, the support element 170 may comprises a magnetic material. It should be noted that the heat sink 130 may be significantly larger and/or be significantly heavier than the support element 170. Explained differently, the support element 170 may be a low-weight and/or low-volume component compared to the heat sink 130. For example, the support element 170 may have a first volume, V i, and a first weight, Wi, and the heat sink 130 may have a second volume, V2, and a second weight, W2, wherein Vi < O.OFV2 and/or Wi < 0.01 -W2 is fulfilled.

In Fig. lb, the support element 170 is arranged in (direct physical) contact with the light converting element 160 (i.e. is arranged under the light converting element 160), and the support element 170 at least partially faces the (underlying) heat sink 130. The support element 170 may be a (heat spreading) substrate, or the like. The support element 170 is arranged in thermal contact with the light converting element 160 and the heat sink 130, and the support element 170 is arranged to spread heat from the light converting element 160 to the heat sink 130.

The light generation system 100 further comprises a movement mechanism 200, which is schematically indicated in Fig. lb. The movement mechanism 200 is configured to move the structure in the second plane, P2, between the laser light arrangement and the heat sink 130. The movement mechanism 200, may be, or comprise, a piezo actuator, a magnetic actuator, a linear motor, a rotational motor, etc.

Fig. 2 schematically shows a light generation system 100 during operation according to an exemplifying embodiment of the present invention. In the leftmost figure, which may represent a first position of the structure 140, the laser light from the laser light arrangement 110 is incident and focused on a first sub-area, Ai, of the focal area, AL, of the light converting element 160 of the structure 140. The first sub-area, Ai, is exemplified as being provided on a left-hand side portion of the light-converting element 160. Furthermore, the first sub-area, Ai, is exemplified as a spot. The diameter of the spot may preferably be 0.05-3 mm, more preferred 0.1-2 mm, and most preferred 0.2-1 mm. The spot shape is preferably round, but may take on other forms as well.

Thereafter, e.g. after a predetermined time, the movement mechanism is configured to move the structure 140 such that the focused emitted laser light, previously incident on the first sub-area, Ai, of the focal area, AL, becomes incident on a second subarea, A2, of the focal area, AL, different from the first sub-area, Ai. In this center figure, which may represent a second position of the structure 140, the second sub-area, A2, is exemplified as being provided on a center portion of the light-converting element 160. Analogously, the movement mechanism may thereafter be configured to move the structure 140 such that the focused emitted laser light, previously incident on the first sub-area, A2, of the focal area, AL, becomes incident on a third sub-area, A3, of the focal area, AL, different from the first and second sub-areas, Ai, A2. In this right-most figure, which may represent a third position of the structure 140, the third sub-area, A3, is exemplified as being provided on a right-hand side portion of the light converting element 160. Hence, the structure 140 and the light converting element 160 is moved by the movement mechanism from the first position, via the second position, to the third position. As a result, and according to the example in Fig. 2, the effective area of the light converting element 160 is (becomes) three times larger with respect to a stationary situation, i.e. if the structure 140 with the lightconverting element 160 would not be moved. It will be appreciated that the number of subareas of the light-converting element 160 is arbitrary, and that the movement mechanism furthermore may move the structure 140 in two dimensions. Hence, it will be appreciated that the (linear) motion of the movement mechanism for moving the structure 140 shown in Fig. 2 is purely for reasons for understanding, and that many different movements are possible. Figs. 3a and 3b schematically show a light generation system during operation according to an exemplifying embodiment of the present invention.

In Fig. 3a, the laser light from the laser light arrangement is incident and focused on a first sub-area, Ai, of the focal area, AL, of the light converting element 160 of the structure 140. The first sub-area, Ai, is exemplified as being provided on a left-hand side portion of the light-converting element 160. Furthermore, the first sub-area, Ai, is exemplified as a spot, wherein the diameter may be approximately 2 mm. The relation between an area, AT, of the sub-area, Ai, of the focal area, AL, and the focal area, AL, which equally represents the scanning area and is indicated by individually separated spots, fulfills 2- AT < AL < 8-AT. According to another example, the relation between atop surface area, Ps, of the light converting element 160, and the focal area, AL, fulfills AL < Ps < 3 -AL.

In Fig. 3b, the laser light from the laser light arrangement is incident and focused on a first sub-area, Ai, of the focal area, AL, of the light converting element 160 of the structure 140, and the movement mechanism is configured to continuously move the structure 140. Consequently, and compared to the separate (distinct) spots of Fig. 3a, the focal area, AL, of scanning area represent a continuous area. Hence, whereas the sub-areas of the focal area, AL, in Fig. 3a are discrete, the sub-areas of the focal area, AL, in Fig. 3a partly overlap. Similarly with the example of Fig. 3a, the relation between the area, AT, of the subarea, Ai, of the focal area, AL, and the focal area, AL, fulfills 2- AT < AL < 8-AT, and the relation between the top surface area, Ps, of the light converting element 160, and the focal area, AL, fulfills AL < Ps < 3 -AL.

Fig. 4 schematically shows a light generation system during operation according to an exemplifying embodiment of the present invention. Here, the focal area, AL, of the light converting element 160 comprises a predetermined apportionment of sub-areas, Am,n, in the form of a two-dimensional matrix or grid of spots with m = 2 rows and n = 3 columns, i.e. 2 x 3 = 6 sub-areas, A_m,n. It will be appreciated that the number of rows and columns may be arbitrary. In the leftmost figure, the laser light from the laser light arrangement is incident and focused on a first sub-area, A24, of the focal area, AL, of the light converting element 160 of the structure 140. Thereafter, e.g. after a predetermined time, the movement mechanism is configured to move the structure 140 such that the focused emitted laser light, previously incident on the first sub-area, A2,I, of the focal area, AL, becomes incident on a second sub-area, A2,2, and thereafter, on a third sub-area, A2 , of the focal area, AL. Hence, the movement mechanism moves the structure 140 linearly from first sub-area, A24, via the second sub-area, A2,2, to the third sub-area, A2 . Subsequently, the movement mechanism is configured to move the structure 140 to a fourth sub-area, AI,3, a fifth sub-area, Ai, 2, and a sixth sub-area, Ai,i, respectively. As a result, and according to the example in Fig. 4, the effective area of the light converting element 160 is (becomes) six times larger with respect to a stationary situation, i.e. if the structure 140 with the light-converting element 160 would not be moved. Optionally, the path, pattern and/or loop in Fig. 4, which the movement mechanism may be configured to operate according to for movement of the structure 140, may be iterated, reversed, etc., i.e. that the movement mechanism may be configured to move the structure 140 via rotation. Furthermore, it will be appreciated that this path, pattern and/or loop in Fig. 4 represents an example of a (predetermined) path that the movement mechanism may be configured to operate according to, and that the movement mechanism may be configured to operate according to substantially any path, pattern and/or loop. For example, the movement mechanism may be configured to move the structure 140 via oscillation, such as (linear) oscillation between two or more sub-areas arranged linearly.

According to an example of the present invention, the heat sink may comprise copper, Cu. Furthermore, the heat sink length, 1, may be 70-130 mm, such as e.g. 85-115 mm, and its width, w, may be 70-130 mm, such as e.g. 85-115 mm. Furthermore, the thickness, t, may be 1-5 mm, such as 2-4 mm, and the weight may be 55-95 g, such as 65-85g. The characteristics of the heat sink of the light generation system of the present invention may, according to an even more specific and/or preferred example, be exemplified by the data in Table 1.

Table 1

In Table 2, the effect of the size of the heat support element and the gap dimension, d, and the heat sink on the temperature of the phosphor (of the light converting element= is shown. It is shown that with increasing size of the support element and decreasing gap dimension, d, the temperature of the phosphor of the light converting element decreases. These parameters can be optimized for a given application. Table 2 reveals that the temperature of the phosphor of the light converting element placed on a support element with a size of 35 mm x 35 mm at a dimension/distance, d, of 5 pm from the heat sink becomes only 168°C after dissipation of heat with a power of 60 W.

Table 2

Fig. 5 schematically shows examples of (lighting) devices or arrangements which may comprise the light generation system 100 according to any one of the preceding embodiments. For example, there is provided a lamp 1 arranged on a wall 1307 in a room 1300, wherein the lamp 1 is arranged to emit light 1201. The light generation system 100 of the lamp 1 is schematically indicated in the lamp 1. According to another example, there is provided a luminaire 2 arranged in the ceiling 1310 of the room 1300, wherein the luminaire 2 is arranged to emit light 1201. The light generation system 100 of the luminaire 1 is schematically indicated in the luminaire 2. The light generation system 100 may alternatively be arranged in a projector device (system) 3, which may be used to project images 1205 on the wall 1307. According to other, non-disclosed examples, there may be provided a disinfection device, a photochemical reactor, or an optical wireless communication device, comprising the light generation system 100 according to any one of the preceding embodiments. Furthermore, for any one of the above-described examples of the (lighting) devices or arrangements, there may be provided a controller (not shown) configured to control the movement mechanism of the light generation system. The person skilled in the art realizes that the present invention by no means is limited to the preferred embodiments described above. On the contrary, many modifications and variations are possible within the scope of the appended claims. For example, one or more of the heat sink 130, structure 140, the light converting element 160, the support element 170, etc., may have different shapes, dimensions and/or sizes than those depicted/described.

Claims

CLAIMS:

1. A light generation system (100), comprising: a laser light arrangement (110) comprising a laser light source (115) arranged to emit laser light (120) and an optical element configured to focus the emitted laser light, a heat sink (130) extending in a first plane, Pi, a structure (140) extending in a second plane, P2, parallel to the first plane, Pi, wherein the structure is arranged between the laser light arrangement and the heat sink, and is physically separated from the heat sink by a gap (150), the structure comprising: a light converting element (160) configured to at least partially convert laser light into converted light (165), wherein the light converting element has a focal area, AL, arranged to receive the focused emitted laser light, and a support element (170) arranged to support the light converting element and at least partially facing the heat sink, wherein the support element is arranged in thermal contact with the light converting element and the heat sink, and is arranged to spread heat from the light converting element to the heat sink, and a movement mechanism (200) configured to move the structure in the second plane, P2, between the laser light source arrangement and the heat sink, such that the focused emitted laser light, incident on any first sub-area, Ai,j, of the focal area, AL, subsequently after a predetermined time becomes incident on any second sub-area, Ak,i, of the focal area, AL, different from the first sub-area, Aij, and wherein the focal area, AL, has at least one optical property being constant for the focal area, AL such that at least one property of the converted light (165) is constant.

2. The light generation system according to claim 1, wherein the focal area, AL, comprises a predetermined apportionment of sub-areas, A_m,n, of the focal area, AL.

3. The light generation system according to claim 1 or 2, wherein the movement mechanism is configured to move the structure in a repetitive or periodic movement via one of rotation and oscillation.

4. The light generation system according to any one of the preceding claims, wherein a relation between an area, AT, of a sub-area, Aij, of the focal area, AL, and the focal area, AL, fulfills 2-AT < AL < 8-AT.

5. The light generation system according to any one of the preceding claims, wherein a relation between a top surface area, Ps, of the light converting element, and the focal area, AL, fulfills AL < Ps < 3-AL.

6. The light generation system according to any one of the preceding claims, wherein the converted light (165) is white light having a correlated color temperature in a range from 2000 to 6500 K with a color rendering index of at least 80.

7. The light generation system according to any one of the preceding claims, wherein the support element comprises a magnetic material.

8. The light generation system according to any one of the preceding claims, wherein the movement mechanism comprises at least one of a piezo actuator, a magnetic actuator, a linear motor and a rotational motor.

9. The light generation system according to any one of the preceding claims, wherein the structure further comprises a reflective layer arranged between the light converting element and the support element.

10. The light generation system according to any one of the preceding claims, wherein the gap has a dimension, d, in a range from 1-50 pm, and wherein the gap is at least partially filled with a fluid.

11. The light generation system according to any one of the preceding claims, wherein the support element has a first volume, Vi, and a first weight, Wi, and the heat sink has a second volume, V2, and a second weight, W2, wherein at least one of

Vi < 0.01-V₂, and

Wi < 0.01-W₂, is fulfilled.

12. The light generation system according to any one of the preceding claims, wherein the light converting element comprises a ceramic phosphor layer.

13. The light generation system according to any one of the preceding claims, wherein at least one of: the material comprises copper, Cu, the length, 1, is 70-130 mm, the width, w, is 70-130 mm, the thickness, t, is 1-5 mm, the weight is 55-95 g, is fulfilled for the heat sink.

14. A lighting device (1200) selected from the group consisting of a lamp (1), a luminaire (2), a projector device (3), a disinfection device, a photochemical reactor, and an optical wireless communication device, comprising: the light generation system according to any one of the preceding claims, and a controller configured to control the movement mechanism.

15. A method for light generation via a light generation system (100), comprising a laser light arrangement (110) comprising a laser light source arranged to emit laser light (120), and an optical element configured to focus the emitted laser light, a heat sink (130) extending in a first plane, Pi, a structure (140) extending in a second plane, P2, parallel to the first plane, Pi, wherein the structure is arranged between the laser light arrangement and the heat sink, and is physically separated from the heat sink by a gap (150), the structure comprising a light converting element (160) configured to at least partially convert laser light into converted light (165), wherein the light converting element has a focal area, AL, arranged to receive the focused emitted laser light, wherein the focal area, AL, has at least one optical property being constant for the focal area, AL such that at least one property of the converted light (165) is constant, and a support element (170) arranged to support the light converting element and at least partially facing the heat sink, wherein the support element is in thermal contact with the light converting element and the heat sink, and is arranged to spread heat from the light converting element to the heat sink, wherein the method comprises: moving the structure in the second plane, P2, between the laser light source arrangement and the heat sink, such that the focused emitted laser light, incident on any first sub-area, Aij, of the focal area, AL, subsequently after a predetermined time becomes incident on any second sub-area, Ak,i, different from the first sub-area, Aij.