A stage lighting fixture

Abstract

A light generation system (1) providing, in operation, system light and comprising a first laser light source (2) configured to generate a first light beam (9) being emitted in and having a main optical axis extending in a first direction (D1), a second laser light source (3) configured to generate a second light beam (10) being emitted in and having a main optical axis extending in a third direction (D3), a wavelength conversion unit (4) being configured to convert the second light beam (11) into a converted light beam (12) being emitted in a fourth direction (D4), and comprising a wavelength conversion member (29) and a heat sink element (30) arranged in thermal contact with the wavelength conversion member, a beam tilting diffusor (5) configured to transmit, diffuse and tilt around a tilting angle (β) the first light beam (9) into a diffused first light beam (25) propagating in and having a main optical axis extending in a second direction (D2), the second direction (D2) being different from the first direction (D1) and extending in the tilting angle (β) with the first direction (D1), and a dichroic reflecting unit (6) being arranged downstream of the beam tilting diffusor (5) and downstream the wavelength conversion unit (4) such as to receive both the diffused first light beam (25) and the converted light beam (12), to transmit the diffused first light beam (25) in a fifth direction (D5), and to reflect the converted light beam (12) in the fifth direction (D5), or the dichroic reflecting unit (6) being arranged downstream of the beam tilting diffusor (5) such as to receive both the diffused first light beam (25) and the converted light beam (12), to transmit the converted light beam (12) in a fifth direction (D5) and to reflect the diffused first light beam (25) in the fifth direction (D5).

Description

[0001] A stage lighting fixture

[0002] FIELD OF THE INVENTION

[0003] The invention relates to a light generation system comprising a first laser light source, a second laser light source, a wavelength conversion unit, a dichroic reflecting unit, and a reflecting unit. The invention further relates to a lamp or a luminaire comprising such a light generation system.

[0004] As used herein, the term “blue light” is intended to refer to light with a peak wavelength falling within the wavelength interval of 420 nm to 500 nm, such as in the range of 440 nm to 490 nm.

[0005] As used herein, the term “green light” is intended to refer to light with a peak wavelength falling within the wavelength interval of 500 nm to 540 nm.

[0006] As used herein, the term “yellow light” is intended to refer to light with a peak wavelength falling within the wavelength interval of 540 nm to 580 nm.

[0007] As used herein, the term “orange light” is intended to refer to light with a peak wavelength falling within the wavelength interval of 580 to 600 nm.

[0008] As used herein, the term “red light” is intended to refer to light with a peak wavelength falling within the wavelength interval of 600 to 700 nm.

[0009] As used herein, the terms “upstream” and “downstream” are intended to be understood relative to the direction of propagation of light through the light generation system.

[0010] BACKGROUND OF THE INVENTION

[0011] Luminaires, such as stage lighting fixtures, are used in touring, stage, DJ, and Club area applications. Stage lighting fixtures use high-brightness extreme-cool-white light sources such as discharge lamps, e.g., Philips MSR lamps. It is desired to improve the performance of luminaires, such as stage lighting fixtures.

[0012] US 2023 / 0280003 Al discloses a light generating system comprising a light generating device, a luminescent material layer, and optics, where the light generating device is configured to generate polarized laser radiation, the luminescent material layer comprises a luminescent material configured in a light-receiving relationship with the light generating device and configured to convert at least part of the polarized laser radiation into luminescent material radiation, the light generating system is configured to generate in an operational mode system light at least comprising the luminescent material radiation, the optics comprise first optics and second optics. The first optics are configured to change the polarization of the polarized laser radiation, and the second optics have one or more of a polarization dependent transmission and a polarization dependent reflection for the polarized laser radiation, The light generating device and the optics are configured such that, relative to an optical path of the luminescent material radiation emanating from the luminescent material, the second optics are configured downstream from the first optics and the luminescent material.

[0013] In laser-phosphor lighting, the most basic configuration for color tunable light source in that blue laser light is converted to green-yellow light using a phosphor while a second laser source is directed to preferably a polarization maintaining diffusor for obtaining the same beam profile as the green-yellow light. In such a configuration green-yellow and blue beam are combined using a polarizing beam splitter for blue light. However, this configuration is rather lossy, and combining laser light with light of other wavelengths is rather difficult at a single polarization maintaining diffusor as quarter wave plates work mostly for a single wavelength. On the other hand, in a transmissive diffusor mode such a configuration is not intrinsically eye safe because in the case of diffusor failure direct laser light is transmitted through the system.

[0014] It is therefore desired to provide a light generation system, such as a stage lighting fixture, with which light losses are lowered or minimized as compared to the prior art solutions, and which is also eye safe.

[0015] SUMMARY OF THE INVENTION

[0016] It is an object of the present invention to overcome this problem, and to provide a light generation system with which light losses are lowered or minimized as compared to the prior art solutions, and which is also eye safe.

[0017] According to a first aspect of the invention, this and other objects are achieved by means of a light generation system providing, in operation, system light, the light generating system comprising a first laser light source, a second laser light source, a wavelength conversion unit, a beam shifting diffusor, and a dichroic reflecting unit, where the first laser light source is configured to generate a first light beam being first blue laser light, the first light beam being emitted in and having a main optical axis extending in a first direction, DI, the beam tilting diffusor is configured to transmit, diffuse and tilt around a tilting angle, P, the first light beam into a diffused first light beam propagating in and having a main optical axis extending in a second direction, D2, the second direction, D2, being different from the first direction, DI, and extending in the tilting angle, , with the first direction, DI, the second laser light source is configured to generate a second light beam being second blue laser light, the second light beam being emitted in and having a main optical axis extending in a third direction, D3, the wavelength conversion unit being configured to convert the second light beam into a converted light beam, the converted light beam being emitted in a fourth direction, D4, the wavelength conversion unit comprises a wavelength conversion member and a heat sink element arranged in thermal contact with the wavelength conversion member, and the dichroic reflecting unit being arranged downstream of the reflecting unit and downstream of the wavelength conversion unit such as to receive both the diffused first light beam and the converted light beam, the dichroic reflecting unit being configured to either transmit the diffused first light beam in a fifth direction, D5, and reflect the converted light beam in the fifth direction, D5, or the dichroic reflecting unit being arranged downstream of the beam tilting diffusor and downstream the wavelength conversion unit such as to receive both the diffused first light beam and the converted light beam, the dichroic reflecting unit being configured to transmit the converted light beam in the fifth direction D5, and reflect the diffused first light beam in the fifth direction. Thereby, the dichroic reflecting unit ensures that the first light beam and the converted light beam are merged to an added light beam, the added light beam forming the system light.

[0018] Thereby, and especially by providing a beam tilting diffusor configured to diffuse the first light beam into a diffused first light beam and to tilt the direction of propagation of the diffused first light beam into a second direction, D2, being different from the first direction, DI, a light generation system with which light losses are lowered or minimized as compared to the prior art solutions, and which is also eye safe, is provided for.

[0019] The first direction, DI, may be normal to a first main surface of the beam tilting diffusor. That is, the first direction, DI, may be arranged under an angle, 0, with respect to the first main surface of the beam tilting diffusor, where the angle 0 is 90 degrees. The advantage of this configuration is to enable better projection, e.g., focus the first light beam (with respect to a normal to the surface) onto the beam tilting diffuser.

[0020] Alternatively, the first direction, DI, may be arranged under an angle, 0, with respect to the first main surface of the beam tilting diffusor, and the angle, 0, may be in a range from 90 to 20 degrees. The advantage of this configuration is that the diffused first light beam becomes more symmetric (with respect to a normal to the surface). In the latter case, the chosen interval of the angle 0 has been shown to be an optimal compromise between avoiding light losses and taking into account the placement of a lens dump and / or a fourth beam focusing element, both being described further below, when these are present.

[0021] The angle 0 may be at least 20 degrees, at least 22 degrees, at least 25 degrees, at least 30 degrees such as for example 25 degrees or 30 degrees. The higher the angle the more compact the light generating system.

[0022] The angle 0 may be at most 85 degrees, at most 65 degrees, at most 60 degrees, at most 90 degrees. The lower the angle the less distortion in the beam shape (or spot shape), because at higher angles the beam shape (or spot shape) becomes distorted.

[0023] The angle 0 may be in a range from 20 to 90 degrees, such as in a range from 25 to 90 degrees, such as in a range from 30 to 90 degrees, such as in a range from 40 to 90 degrees. Such a range is an optimum between compactness of the system and less distortion in the beam shape (or spot shape).

[0024] The beam tilting diffusor may be configured to tilt the light beam to a second direction, D2, having an angle, y, with respect to a second main surface opposite to the first main surface of the beam tilting diffusor, wherein the angle, y, is in a range from 20 to 90 degrees, such as in a range from 25 to 90 degrees, such as in a range from 30 to 90 degrees, such as in a range from 40 to 90 degrees.

[0025] The beam tilting diffusor may comprise a first optical element configured to redirect at least part of the first light beam. For instance, the first optical element may be at least one of a refractive optical element, exemplary refractive optical elements being an array of non-symmetric microprisms, or a prismatic sawtooth structure, or a plurality of non- spherical lenslets; and a diffractive optical element, exemplary diffractive optical elements being a phase grating, a ruled grating, or a holographic optical element, or a surface relief element.

[0026] An array of linear, non-symmetric microprisms provides the advantage of being particularly well suited for effectively deflecting a collimated or nearly collimated light beam.

[0027] Holographic films provide the advantage of being especially well suited for effectively collimating and changing the direction of a beam of light.

[0028] Diffractive optical elements and substrates comprising a prismatic sawtooth structure provide the advantage of being especially well suited for effectively changing the direction of a beam of light. Gratings provide the advantage of being especially well suited for effectively changing the direction of a beam of light while having a particular simple structure.

[0029] The beam tilting diffusor may comprise a second optical element being a light scattering optical element, exemplary light scattering optical elements being a volume scatterer or a surface scatterer.

[0030] Still further, the beam tilting diffusor may comprise one of: a combination of (i) the first optical element and (ii) the second optical element, the second optical element being arranged downstream the first optical element, and a combination of (i) the second optical element, and (ii) the first optical element, the first optical element being arranged downstream the second optical element.

[0031] Thereby, an especially well functioning beam tilting diffusor capable of transmitting, diffusing, and tilting around a tilting angle, , the first light beam into a diffused first light beam in a particularly efficient way with a particularly low loss of light.

[0032] The light generation system may further comprise a further dichroic reflecting unit arranged upstream of the dichroic reflecting unit, the further dichroic reflecting unit being configured to (i) transmit the second light beam, and reflect the converted light beam, or (ii) reflect the second light beam, and transmit the converted light beam, and the dichroic reflecting unit may be configured to reflect the diffused first light beam in the fifth direction, D5, and transmit the converted light beam in the fifth direction, D5, such that the diffused first light beam and the converted light beam are merged to an added light beam, the added light beam forming the system light.

[0033] The dichroic reflecting unit may be arranged downstream of the beam tilting diffusor such as to receive both the diffused first light beam and the converted light beam, the dichroic reflecting unit being configured to transmit the diffused first light beam in a fifth direction, D5, and reflect the converted light beam in the fifth direction, D5, and the second direction, D2, and the fifth direction, D5, is the same direction.

[0034] The dichroic reflecting unit may be arranged downstream of the beam tilting diffusor such as to receive both the diffused first light beam (in the second direction, D2) and the converted light beam, the dichroic reflecting unit being configured to transmit the diffused first light beam in a fifth direction, D5, and reflect the converted light beam in the fifth direction, D5, and the second direction, D2, and the fifth direction, D5 are mutually different directions, and the light generation system further comprises at least one reflecting unit, the at least one reflecting unit being configured to reflect the diffused first light beam in the fifth direction, D5. In either case it is thereby ensured that the diffused first light beam propagates in the fifth direction, D5, before reaching and being transmitted by the dichroic reflecting unit. Thereby it is ensured that the diffused first light beam is properly and without light loss transmitted by the dichroic reflecting unit.

[0035] The light generation system may further comprise a first beam focusing element arranged between the second laser light source and the wavelength conversion unit, the first beam focusing element being configured to focus the second light beam onto the wavelength conversion unit and to collimate the converted light beam.

[0036] Thereby, it is ensured that all of the second light beam is impinging on the wavelength conversion unit and thus becomes converted. Thereby light losses in the system are lowered.

[0037] The first beam focusing element may comprise a lens or a lens assembly. Thereby, a particularly simple beam focusing element is provided for.

[0038] The wavelength conversion member comprises a luminescent material of the type A3BsOi2:Ce, where A may denote one or more of Y, La, Gd, Tb and Lu, especially at least one or more of Y, Gd, Tb and Lu, and where B may denote one or more of Al, Ga, In and Sc. In embodiments, the wavelength conversion member comprises one or more luminescent materials.

[0039] The luminescent material may comprise one or more of MS:Eu2+ and / or M2SisN8:Eu2+and / or MAISiN.vEu2and / or Ca2AlSi3O2Ns:Eu2+, etc., wherein M comprises one or more of Ba, Sr and Ca, especially in embodiments at least Sr. Hence, in embodiments, the luminescent may comprise one or more materials selected from the group consisting of (Ba,Sr,Ca)S:Eu, (Ba,Sr,Ca)AlSiN3:Eu and (Ba,Sr,Ca)2SisN8:Eu. In these compounds, europium (Eu) is substantially or only divalent, and replaces one or more of the indicated divalent cations. In general, Eu will not be present in amounts larger than 10% of the cation; its presence will especially be in the range of about 0.5 to 10%, more especially in the range of about 0.5 to 5% relative to the cation(s) it replaces.

[0040] The luminescent material may comprise a luminescent material of the type M’XM2-2XAX6 doped with tetravalent manganese, wherein M’ comprises an alkaline earth cation, M comprises an alkaline cation, and x is in the range of 0-1, wherein A comprises a tetravalent cation, for instance comprising one or more of silicon and titanium, wherein X comprises a monovalent anion, at least comprising fluorine. Herein, M’xM2-2xAX6 doped with tetravalent manganese, may further also shortly be indicated as “phosphor”, i.e. the phrase " phosphor comprising M’xM2-2xAX6 doped with tetravalent manganese" may in an embodiment also be read as M’xM2-2xAX6 doped with tetravalent manganese phosphor, or (tetraval ent) Mn-doped M’xM2-2xAX6 phosphor, or shortly "phosphor". Relevant alkaline cations (M) are sodium (Na), potassium (K) and rubidium (Rb). Optionally, also lithium and / or cesium may be applied. In a preferred embodiment, M comprises at least potassium. In yet another embodiment, M comprises at least rubidium. The phrase “wherein M comprises at least potassium” indicates for instance that of all M cations in a mole M’xNfc- 2xAXe , a fraction comprises K+and an optionally remaining fraction comprises one or more other monovalent (alkaline) cations (see also below). In another preferred embodiment, M comprises at least potassium and rubidium. Optionally, the M’xM2-2xAX6 luminescent material has the hexagonal phase. In yet another embodiment, the M’xM2-2xAX6 luminescent material has the cubic phase. Relevant alkaline earth cations (M’) are magnesium (Mg), strontium (Sr), calcium (Ca) and barium (Ba), especially one or more of Sr and Ba. Thereby, a wavelength conversion member providing a particularly efficient and complete conversion of the second light beam into light of the desired peak wavelength is obtained.

[0041] The wavelength conversion unit may be configured to generate a converted light beam having a peak emission wavelength in a wavelength range from 500 nm to 580 nm, or from 510 nm to 580 nm.

[0042] The light generation system may further comprise a first beam homogenizer being configured to homogenize the first light beam into a homogenized first light beam.

[0043] The first beam homogenizer may also be configured to homogenize the first light beam and the third light beam into the homogenized first light beam.

[0044] Thereby, the first beam is provided with a uniform power over the crosssection of the beam. This in turn provides for a more uniform first light beam, and eventually a more uniform added light beam or system light.

[0045] The light generation system may further comprise a second beam homogenizer being configured to homogenize the second light beam into a homogenized second light beam.

[0046] Thereby, the second light beam is provided with a uniform power over the cross-section of the beam. This in turn provides for a more uniform second light beam, and eventually a more uniform added light beam or system light.

[0047] The light generation system may further comprise a third beam homogenizer being configured to homogenize the added light beam into a homogenized added light beam. Thereby, the added light beam is provided with a uniform power over the cross-section of the beam. This in turn provides for a more uniform added light beam or system light.

[0048] The light generation system may further comprise a partially reflecting unit arranged between the first laser source and the beam tilting diffusor and configured to reflect a part of the first light beam in a sixth direction, D6, towards the second light beam, and a beam combining unit arranged between the second laser source and the dichroic reflecting unit and configured to combine the part of the first light beam and the second light beam.

[0049] Thereby, it is ensured that a part of the first light beam is reflected and merged with the second light beam, while only a part of the first light beam is propagating through the beam shifting diffusor. Thereby it becomes possible to change the combination of light eventually forming the added light beam or system light to comprise a larger fraction of converted light.

[0050] The light generation system may further comprise at least one third laser source arranged adjacent to the first laser source, the at least one third laser source being configured to generate a third light beam being a light beam of a color different from blue, the third light beam being emitted in the first direction, DI.

[0051] The light generation system may further comprise a third beam focusing element arranged between the first laser source and the beam shifting diffusor, the third beam focusing element being configured to focus the first light beam onto the beam shifting diffusor.

[0052] Alternatively, if a second beam homogenizer is provided, the light generation system may further comprise a third beam focusing element arranged between the second beam homogenizer and the beam shifting diffusor, the third beam focusing element being configured to focus the homogenized first light beam onto the beam shifting diffusor.

[0053] Thereby, it is ensured that all of the first light beam is impinging on the beam tilting diffusor and thus becomes both diffused and directionally changed. Thereby light losses in the system are lowered.

[0054] The light generation system may further comprise a further reflecting unit arranged between the wavelength conversion unit and the dichroic reflecting unit, the further reflecting unit being configured to reflect the converted light beam towards the dichroic reflecting unit.

[0055] Thereby, it becomes possible to provide a light generation system in which the wavelength conversion unit is used in a transmissive mode, in which the second light beam impinges on the wavelength conversion unit on one side thereof, is converted during transmission through the wavelength conversion unit, and the converted light beam is emitted from the wavelength conversion unit from an opposite side thereof.

[0056] The further reflecting unit may further comprise a heat sink element.

[0057] Thereby, the temperature of the further reflecting unit may be kept down, and negative effects from the heat on the reflected light may be mitigated.

[0058] The light generation system may further comprise a fourth beam focusing element arranged between the beam tilting diffusor and the reflecting unit, the fourth beam focusing element being configured to collimate the diffused first light beam.

[0059] Thereby, it is ensured that the beam reflected by the reflecting unit is a collimated light beam, which in turn provides for a well-defined beam after reflections as well as lowers light losses in the system.

[0060] The dichroic reflecting unit may further be configured to receive the second light beam, or if a second beam homogenizer is provided the homogenized second light beam, and transmit the second light beam, or the homogenized second light beam, in the third direction, D3, towards the wavelength conversion unit, and wherein the wavelength conversion unit further is configured to reflect the converted light beam back towards the dichroic reflecting unit in the fourth direction, D4.

[0061] Alternatively, the dichroic reflecting unit may further be configured to receive the second light beam and reflect the second light beam in an eighth direction, D8, towards the wavelength conversion unit, and wherein the wavelength conversion unit further is configured to reflect the converted light beam back towards the dichroic reflecting unit in the fourth direction, D4.

[0062] Thereby, it becomes possible to provide a light generation system in which the wavelength conversion unit is used in a reflective mode, in which the second light beam impinges on the wavelength conversion unit on one side thereof, is converted during transmission through the wavelength conversion unit, and the converted light beam is reflected and emitted from the wavelength conversion unit from the same side thereof.

[0063] The light generation system may further comprise a beam dump arranged and configured to absorb at least parts of the first light beam propagating past the beam tilting diffusor and / or parts of the diffused light beam propagating past the fourth beam focusing element. In other words, the beam dump is arranged and configured to absorb parts of the first light beam not being transmitted, diffused, and tilted by the beam tilting diffusor and / or parts of the diffused light beam not being collimated by the fourth beam focusing element. Generally, a beam dump, also known as a beam block, a beam stop, or a beam trap, is a device designed to absorb the energy of photons or other particles within an energetic beam. Thereby, the safety, and especially the eye safety, of the light generation system is increased even further by ensuring that rays of light otherwise leaving the light generation system uncontrollably are thus absorbed.

[0064] The system light may comprise the diffused first light beam and the converted second light beam, and the system light may be white light having a correlated color temperature in a range from 2700 K to 9000 K and a CRI of at least 70, preferably having a correlated color temperature in a range from 3500 to 9000 K and a CRI of at least 80.

[0065] The first laser light source may comprise any one of: a laser light source configured to generate a blue light beam, a laser light source configured to generate a blue light beam and a laser light source configured to generate a red light beam, and a laser bank.

[0066] The second laser light source may comprise any one of a laser light source configured to generate a light beam of any color, and a laser bank.

[0067] The first laser light source and the second laser light source may be combined into one laser light arrangement having an array of laser light sources and from which the light is divided into the first light beam and the second light beam.

[0068] Thereby, a more compact light generation system may be obtained.

[0069] The invention further relates to a lamp or a luminaire comprising a light generation system according to the invention.

[0070] The lamp or the luminaire may, thanks to the light generation system, provide system light which may comprise the diffused first light beam and the converted second light beam, and the system light may be white light having a correlated color temperature in a range from 2700 K to 9000 K and a CRI of at least 70, or at least 80.

[0071] The lamp or luminaire may be any type of lamp and luminaire, but particularly a stage lighting luminaire or fixture.

[0072] The terms “upstream” and “downstream” relate to an arrangement of items or features relative to the propagation of the light from a light generating means (here the especially the light source), wherein relative to a first position within a beam of light from the light generating means, a second position in the beam of light closer to the light generating means is “upstream”, and a third position within the beam of light further away from the light generating means is “downstream”. The term “white light”, and similar terms, herein, is known to the person skilled in the art. It may especially relate to light having a correlated color temperature (CCT) between about 1800 K and 20000 K, such as between 2000 and 20000 K, especially 2700- 20000 K, for general lighting especially in the range of about 2000-7000 K, such as in the range of 2700 K and 6500 K. In embodiments, e.g. for backlighting purposes, or for other purposes, the correlated color temperature (CCT) may especially be in the range of about 7000 K and 20000 K. Yet further, in embodiments the correlated color temperature (CCT) is especially within about 15 SDCM (standard deviation of color matching) from the BBL (black body locus), especially within about 10 SDCM from the BBL, even more especially within about 5 SDCM from the BBL.

[0073] In specific embodiments, the correlated color temperature (CCT) may be selected from the range of 6000-12000 K, like selected from the range of 7000-12000 K, like at least 8000 K. Yet further, in embodiments the correlated color temperature (CCT) may be selected from the range of 6000-12000 K, like selected from the range of 7000-12000 K, in combination with a CRI of at least 70.

[0074] In the present invention a laser light source especially refers to a laser diode and a superluminescent diode.

[0075] It is noted that the invention relates to all possible combinations of features recited in the claims.

[0076] BRIEF DESCRIPTION OF THE DRAWINGS

[0077] 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.

[0078] Fig. 1 schematically shows an embodiment of a light generation system according to the invention.

[0079] Fig. 2 schematically shows another embodiment of a light generation system according to the invention.

[0080] Fig. 3 schematically shows another embodiment of a light generation system according to the invention.

[0081] Fig. 4 schematically shows another embodiment of a light generation system according to the invention.

[0082] Fig. 5 schematically shows another embodiment of a light generation system according to the invention. Fig. 6 schematically shows another embodiment of a light generation system according to the invention.

[0083] Fig. 7 schematically shows another embodiment of a light generation system according to the invention.

[0084] Fig. 8 schematically shows another embodiment of a light generation system according to the invention.

[0085] Figs. 9A and 9B show a schematic illustration of a beam tilting diffusor of a light generation system according to the invention.

[0086] Figs. 10A and 10B show schematic illustrations of a part of a light generation system illustrating the placement of a beam dump of the light generation system.

[0087] Figs. 11 A and 1 IB show schematic illustrations of a part of another light generation system illustrating the placement of a beam dump of the light generation system.

[0088] As illustrated in the figures, the sizes of layers and regions are exaggerated for illustrative purposes and, thus, are provided to illustrate the general structures of embodiments of the present invention. Like reference numerals refer to like elements throughout.

[0089] DETAILED DESCRIPTION

[0090] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which currently preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled person.

[0091] Fig. 1 schematically shows an embodiment of a light generation system 1 according to an embodiment of the invention. Generally, and irrespective of the embodiment, the light generation system 1 comprises a first laser light source 2, a second laser light source 3, a wavelength conversion unit 4, a beam tilting diffusor 5, and a dichroic reflecting unit 6. Optionally, and as shown on Fig. 1, the light generation system 1 may further comprise a reflecting unit 7. Optionally, and as shown on Fig. 1, the light generation system 1 may still further comprise a first beam homogenizer 15 and / or a second beam homogenizer 8.

[0092] The first laser light source 2 is configured to generate a first light beam 9. The first light beam 9 may be a blue light beam. The first light beam 9 is emitted in a first direction DI. The first light beam 9 comprises a main optical axis extending in the first direction DI. The first laser light source 2 may comprise a laser light source configured to generate a blue light beam. The first laser light source 2 may be a laser 201 or a laser bank. The first laser light source 2 may further comprise a collimating lens 202.

[0093] The second laser light source 3 is configured to generate a second light beam 10. The second light beam 10 is emitted in a third direction D3. The second light beam 10 comprises a main optical axis extending in the third direction D3. The third direction D3 and the first direction DI may be mutually parallel. The second light beam 10 may be a light beam of in principle any color. The second light beam 10 may be of another color than the first light beam 9. The second laser light source 3 may be a laser 301 or a laser bank. The second laser light source 3 may further comprise a collimating lens 302.

[0094] The first laser light source and the second laser light source may also be provided as a single laser light engine that generates two laser beams 9 and 10 as the first and second laser light source 2 and 3, respectively. The first laser light source and the second laser light source may also be provided as a single laser light engine that generates one laser beam, which is then split or tapped into two laser beams 9 and 10 as the first and second laser light source 2 and 3, respectively.

[0095] The optional first beam homogenizer 15 is configured to homogenize light. The first beam homogenizer 15 is arranged to receive the first light beam 9. The first beam homogenizer 15 is arranged and configured to homogenize the first light beam 9 to form a homogenized first light beam 28.

[0096] The optional second beam homogenizer 8 is configured to homogenize light. The second beam homogenizer 8 is arranged to receive the second light beam 10. The second beam homogenizer 8 is arranged and configured to homogenize the second light beam 10 to form a homogenized second light beam 11.

[0097] The beam tilting diffusor 5 is arranged to receive the first light beam 9. The beam tilting diffusor 5 is arranged and configured to convert the first light beam 9 to form a diffused first light beam 25. In case a first beam homogenizer 15 is provided, the beam tilting diffusor 5 is arranged to receive the homogenized first light beam 28. The beam tilting diffusor 5 is then arranged and configured to convert the homogenized first light beam 28 to form the diffused first light beam 25. The beam tilting diffusor 5 is further arranged and configured to change or tilt around a tilting angle the direction of propagation of the diffused first light beam 25 from the first direction DI into a second direction D2. The diffused first light beam 25 comprises a main optical axis extending in the second direction D2. The angle between the first direction DI and the second tilted direction D2 is defined as the tilting angle P, cf. Figs. 1, 10A and 11 A. The first direction DI and the second direction D2 may form an obtuse tilting angle with each other. Generally, and as shown in Figs. 9A and 9B, the beam tilting diffusor 5 comprises a first optical element 51 and a second optical element 52. The first optical element 51 may be a refractive optical element or a diffractive optical element. The second optical element 52 may be a light scattering element or a diffusing element. The first optical element 51 may be any one of an array of linear, non- symmetric microprisms, a holographic film, a diffractive optical element, a substrate comprising a prismatic sawtooth structure, and a grating. The first optical element 51 may be arranged downstream of the second optical element 52. Alternatively, the second optical element 52 may be arranged downstream of the first optical element 51. The beam tilting diffusor 5 further comprises a first main surface 53 and a second main surface 54 opposite to the first main surface 53. The first direction DI generally forms an angle 0 being equal to or larger than 90 degrees with the first main surface 53. As shown in Fig. 1, the first direction DI is perpendicular to (0 = 90 degrees) to the first main surface 53. The second direction D2 generally forms an angle, y, with respect to the second main surface 54 of the beam tilting diffusor 5 - cf. Fig. 10A. The angle, y, may be in a range from 20 to 90 degrees.

[0098] The light generation system comprises at least one reflecting unit 7. The at least one reflecting unit 7 is arranged downstream of the beam tilting diffusor 5 such as to receive the diffused first light beam 25 propagating in the second direction D2. The at least one reflecting unit 7 is arranged and configured to reflect the diffused first light beam 25 in a fifth direction D5. The fifth direction D5 may be perpendicular to the first direction DI. The fifth direction D5 may form an acute angle with the second direction D2. The at least one reflecting unit 7 may for instance be a mirror or a reflecting film or coating arranged on a substrate. As will be clear from the embodiments of Figs. 7 and 8 described further below, the at least one reflecting unit 7 and the beam tilting diffusor 5 may in some embodiments be one and the same element, such that the beam tilting diffusor 5 also performs the function of the at least one reflecting unit 7, namely to change the direction of propagation of the diffused first light beam 25 from the second direction D2 to the fifth direction D5.

[0099] The wavelength conversion unit 4 is arranged to receive the second light beam

[0100] 10. The wavelength conversion unit 4 is arranged and configured to convert the second light beam 10 into a converted light beam 12. In case a second beam homogenizer 8 is provided, the wavelength conversion unit 4 is arranged to receive the homogenized second light beam

[0101] 11. The wavelength conversion unit 4 is then arranged and configured to convert the homogenized second light beam 11 into a converted light beam 12. Generally, and irrespective of the embodiment, the wavelength conversion unit 4 is further arranged and configured to transmit or reflect the converted light beam 12. The wavelength conversion unit 4 comprises a wavelength conversion member 29 and a heat sink element 30. The heat sink element 30 is arranged in thermal contact with the wavelength conversion member 29 such as to provide cooling of the wavelength conversion member 29. The heat sink element 30 may for instance be a heat dissipating substrate or material, such as a metal.

[0102] In the embodiment shown in Fig. 1, the wavelength conversion unit 4 is particularly arranged and configured to reflect the converted light beam 12 back towards the dichroic reflecting unit 6 described further below in a fourth direction D4. The wavelength conversion unit 4 is thus used in a reflective mode or setup. The wavelength conversion unit 4 may thus comprise a reflecting device or layer arranged underneath the wavelength conversion member 29. In this case, the third direction D3 and the fourth direction D4 are mutually opposite directions. The wavelength conversion member 29 may be a phosphor. For example, the wavelength conversion member 29 may be a green-yellow phosphor. For example, the wavelength conversion member 29 may be a YAG phosphor such as illustrated by the graph inserted in Fig. 1 and showing the reflectance of the dichroic reflecting unit 6 as a function of wavelength, and especially wavelengths around those created by the wavelength conversion member 29 and thus contained in the converted light beam 12. For instance, the wavelength conversion member 29 may comprise a luminescent material of the type A3B5O 12: Ce, wherein A may comprise one or more of Y, La, Gd, Tb and Lu, especially (at least) one or more of Y, Gd, Tb and Lu, and wherein B may comprise one or more of Al, Ga, In and Sc. For instance, the wavelength conversion member 29 may configured to generate a converted light beam 12 having a peak emission wavelength in a wavelength range from 510 nm to 580 nm.

[0103] The dichroic reflecting unit 6 is arranged downstream of the beam tilting diffusor 5 and the wavelength conversion unit 4. The dichroic reflecting unit 6 may further be arranged downstream of the reflecting unit 7 and the second laser source 3, and, where provided, also the second beam homogenizer 8, respectively. Generally, and irrespective of the embodiment, the dichroic reflecting unit 6 is arranged to receive both the diffused first light beam 25 propagating in the fifth direction D5 and the converted light beam 12 propagating in the fourth direction D4.

[0104] In the embodiment shown in Fig. 1, the dichroic reflecting unit 6 is particularly arranged and configured to transmit the diffused first light beam 25 such that the diffused first light beam 25 still propagates in the fifth direction D5. The dichroic reflecting unit 6 is further arranged and configured to transmit the second light beam 10. The dichroic reflecting unit 6 is, where a second beam homogenizer 8 is provided, further arranged and configured to transmit the homogenized second light beam 11. The dichroic reflecting unit 6 is further arranged and configured to reflect the converted light beam 12 in the fifth direction D5. Thereby, the diffused first light beam 25 and the converted light beam 12 are merged to an added light beam 26. To obtain this, the second light beam 10, and where a second beam homogenizer 8 is provided the homogenized second light beam 11, is in the embodiment show in Fig. 1 propagating in a third direction D3 being perpendicular to the fifth direction D5.

[0105] Generally, the dichroic reflecting unit 6 is configured to reflect light of a wavelength or wavelength range corresponding to the light generated by the wavelength conversion unit 4. For instance, when the wavelength conversion unit 4 is a green-yellow phosphor, the dichroic reflecting unit 6 is configured to reflect green-yellow light.

[0106] The light generation system 1 may further comprise a first beam focusing element 13. The first beam focusing element 13 is arranged between the second laser source 3 and the wavelength conversion unit 4. The first beam focusing element 13 is more particularly arranged between the dichroic reflecting unit 6 and the wavelength conversion unit 4. The first beam focusing element 13 is more particularly arranged and configured to focus the second light beam 10 onto the wavelength conversion unit 4. In case a second beam homogenizer 8 is provided, the first beam focusing element 13 is more particularly arranged and configured to focus the homogenized second light beam 11 onto the wavelength conversion unit 4. The first beam focusing element 13 may for instance be a lens or an array of lenses.

[0107] The light generation system 1 may further optionally comprise a third beam homogenizer 16. The third beam homogenizer 16 is configured to homogenize light. The third beam homogenizer 16 is arranged and configured to homogenize the added light beam 26 such as to form a homogenized added light beam 27.

[0108] The light generation system 1 thus generates an output in the form of the added light beam 26, or the homogenized added light beam 27 if a third beam homogenizer 16 is provided, comprising blue light and light, such as green-yellow light, converted by the wavelength conversion unit 4.

[0109] Fig. 2 schematically shows another embodiment of a light generation system 100 according to the invention. The light generation system 100 differs from the light generation system 1 described above with reference to Fig. 1 in virtue of the following features.

[0110] The light generation system 100 comprises a first laser light source 2 in the form of a laser bank. The first laser light source 2 comprises a plurality, such as an array, of lasers 201. The first laser light source 2 may in this embodiment further comprise a plurality, such as an array, of collimating lenses 202. The light generation system further 100 comprises a third beam focusing element 23. The third beam focusing element 23 is arranged between the first laser light source 2 and the beam tilting diffusor 5. The third beam focusing element 23 is arranged and configured to focus the first light beam 9 onto the beam tilting diffusor 5. In case a first beam homogenizer 15 is provided, the third beam focusing element 23 is more particularly arranged between the first beam homogenizer 15 and the beam tilting diffusor 5. The third beam focusing element 23 is then arranged and configured to focus the homogenized first light beam 28 onto the beam tilting diffusor 5. The third beam focusing element 23 may for instance be a lens or an array of lenses.

[0111] The light generation system 100 may further comprise a fourth beam focusing element 14. The fourth beam focusing element 14 is arranged between the beam tilting diffusor 5 and the reflecting unit 7. The fourth beam focusing element 14 is arranged and configured to de-focus or collimate the diffused first light beam 25. The fourth beam focusing element 14 may for instance be a lens or an array of lenses.

[0112] Fig. 3 schematically shows another embodiment of a light generation system 101 according to the invention. The light generation system 101 differs from the light generation system 100 described above with reference to Fig 2 in virtue of the following features.

[0113] The light generation system 101 comprises a first laser light source 2 in the form of a laser bank. The setup of the light generation system 101 is generally denoted a 1.5 laser bank configuration.

[0114] The light generation system 101 further comprises a partially reflecting unit 17. The partially reflecting unit 17 is arranged between the first laser source 2 and the beam tilting diffusor 5. In case a first beam homogenizer 15 is provided, the partially reflecting unit 17 is more particularly arranged between the first beam homogenizer 15 and the beam tilting diffusor 5. The partially reflecting unit 17 is arranged and configured to reflect a part 91 of the first light beam 9, or in the embodiment shown in Fig. 3 of the homogenized first light beam 28, in a sixth direction D6 towards the second light beam 10. In the embodiment shown the sixth direction D6 is parallel to the fifth direction D5. The light generation system 101 further comprises a beam combining unit 18. The beam combining unit 18 is arranged between the second laser source 3 and the dichroic reflecting unit 6. In case a second beam homogenizer 8 is provided, the beam combining unit 18 is more particularly arranged between the second beam homogenizer 8 and the dichroic reflecting unit 6. The beam combining unit 18 is configured and arranged to combine the part 91 of the first light beam 9 or of the homogenized first light beam 28 and the second light beam 10 or the homogenized second light beam 11. In this embodiment, the wavelength conversion unit 4 thus converts the light beam combined by the beam combining unit 18 into converted light 12.

[0115] Fig. 4 schematically shows another embodiment of a light generation system

[0116] 102 according to the invention. The light generation system 102 differs from the light generation system 100 described above with reference to Fig. 2 in virtue of the following features.

[0117] The light generation system 102 further comprises at least one third laser source 19. The third laser source 19 is arranged adjacent to the first laser source 9. The third laser source 19 is configured to generate a third light beam 20. The third light beam 20 is emitted in the first direction DI. The third light beam 20 is a light beam of a color different from the color of the first light beam 9. The third light beam 20 may be a light beam of a color different from blue. The third light beam 20 is more particularly of a color being transmittable by the dichroic reflecting unit 6. The third light beam 20 may particularly be a red light beam.

[0118] In this embodiment, the first beam homogenizer 15 is, where provided, further arranged to homogenize the first light beam 9 and the third light beam 20 to form the homogenized first light beam 28.

[0119] The light generation system 102 thus generates an output in the form of the added light beam 26, or the homogenized added light beam 27 if a third beam homogenizer 16 is provided, comprising blue light, red light, and converted light, such as green-yellow light, generated by the wavelength conversion unit 4.

[0120] Fig. 5 schematically shows another embodiment of a light generation system

[0121] 103 according to the invention. The light generation system 103 differs from the light generation systems 1 and 100-102 described above with reference to Figs. 1-4 in virtue of the following features.

[0122] Generally, the light generation system 103 is a setup in which both the beam tilting diffusor 5 and the wavelength conversion unit 4 are operated in a transmission mode. The light generation system 103 therefore comprises both a first beam focusing element 13 and a second beam focusing element 24.

[0123] The first beam focusing element 13 is arranged between the second laser source 3 and the wavelength conversion unit 4. The first beam focusing element 13 is more particularly arranged between the dichroic reflecting unit 6 and the wavelength conversion unit 4. The first beam focusing element 13 is more particularly arranged and configured to focus the second light beam 10, or where a second beam homogenizer 8 is provided the homogenized second light beam 11, onto the wavelength conversion unit 4. The first beam focusing element 13 may for instance be a lens or an array of lenses.

[0124] The second beam focusing element 24 is arranged downstream of the wavelength conversion unit 4. The second beam focusing element 24 is arranged and configured to collimate or de-focus the converted light beam 12 generated by the wavelength conversion unit 4.

[0125] The wavelength conversion unit 4 is in this embodiment arranged and configured to transmit light and to emit the converted light beam 12 in a seventh direction D7 being parallel to the third direction D3. The wavelength conversion unit 4 is thus configured to receive the second light beam 10, or where a second beam homogenizer 8 is provided the homogenized second light beam 11, on one side or surface of the wavelength conversion unit 4, to convert the light during transmission through the wavelength conversion unit 4, and to emit the converted light beam 12 from an opposite side of the wavelength conversion unit 4. The wavelength conversion unit 4 is transmissive, at least in the area of or corresponding to the wavelength conversion member 29.

[0126] As may be seen on Fig. 5, the third direction D3, in which the second light beam 10 is propagating, and the seventh direction, D7, in which the converted second light beam 12 is propagating is in this embodiment perpendicular to the first direction DI.

[0127] The light generation system 103 further comprises a further or second reflecting unit 21. The further reflecting unit 21 is arranged between the wavelength conversion unit 4 and the dichroic reflecting unit 6. The further reflecting unit 21 is arranged and configured to reflect the converted light beam 12 in the fourth direction D4 towards the dichroic reflecting unit 6. In this embodiment, the third direction D3 and the seventh direction D7 are perpendicular to the fifth direction D5. The further reflecting unit 21 may for instance be a mirror or a reflecting film or coating arranged on a substrate. Optionally, the further reflecting unit 21 may comprise a heat sink element 22. The heat sink element 22 may for instance be a heat dissipating substrate or material, such as a metal. Fig. 6 schematically shows another embodiment of a light generation system

[0128] 104 according to the invention. The light generation system 104 differs from the light generation systems 1 and 100-103 described above with reference to Figs. 1-5 in virtue of the following features.

[0129] The light generation system 104 does not comprise any reflecting unit 7.

[0130] However, the light generation system 104 comprises a further dichroic reflecting unit 31. The further dichroic reflecting unit 31 is configured to transmit light of a wavelength or wavelength range corresponding to the light generated by the wavelength conversion unit 4 and to reflect light of a wavelength or wavelength range corresponding to the light 9 emitted by the first laser source 2, and in principle also the light 10 emitted by the second laser light source 3.

[0131] Furthermore, the further dichroic reflecting unit 31 is arranged upstream of the dichroic reflecting unit 6. The further dichroic reflecting unit 31 is arranged and configured to transmit the second light beam 11 and reflect the converted light beam 12. Alternatively, the further dichroic reflecting unit 31 is arranged and configured to reflect the second light beam 11 and transmit the converted light beam 12.

[0132] The dichroic reflecting unit 6 here acts to add the converted light 12 and the diffused first light 25 to form the added light beam 26. Therefore, the dichroic reflecting unit 6 is in this embodiment arranged such as to receive the second light beam 10, or the second homogenized light beam 11, and to reflect second light beam 10, or the second homogenized light beam 11, in an eighth direction D8 towards the wavelength conversion unit 4, and to transmit the converted light beam 12 in the fifth direction D5.

[0133] Fig. 7 schematically shows another embodiment of a light generation system

[0134] 105 according to the invention. The light generation system 105 differs from the light generation systems 1 and 100-104 described above with reference to Figs. 1-6 in virtue of the following features.

[0135] The light generation system 105 does not comprise any separate reflecting unit 7. Instead, the beam tilting diffusor 5 is arranged and oriented in such a way that it also performs the function otherwise undertaken by the reflecting unit 7. In other words, the beam tilting diffusor 5 is arranged and oriented so as to tilt the first beam 9, or if a first beam homogenizer 15 is provided as shown in Fig. 7 the homogenized first beam 28, in a second direction D2 which is identical to the fifth direction D5.

[0136] As shown in Fig. 7, this is here obtained by arranging and orienting the beam tilting diffusor 5 perpendicular to the first direction DI, and by engineering the beam tilting diffusor 5 to tilt the incoming light beam 9 or 28 in an angle corresponding to the angle between the first direction DI and the fifth direction D5.

[0137] Fig. 8 schematically shows another embodiment of a light generation system 106 according to the invention. The light generation system 103 differs from the light generation systems 1 and 100-105 described above with reference to Figs. 1-7 in virtue of the following features.

[0138] The light generation system 106 does not comprise any separate reflecting unit 7. Instead, the beam tilting diffusor 5 is arranged and oriented in such a way that it also performs the function otherwise undertaken by the reflecting unit 7. In other words, the beam tilting diffusor 5 is arranged and oriented so as to tilt the first beam 9, or if a first beam homogenizer 15 is provided as shown in Fig. 8 the homogenized first beam 28, in a second direction D2 which is identical to the fifth direction D5.

[0139] As shown in Fig. 8, this is here obtained by arranging and orienting the beam tilting diffusor 5 perpendicular to the fifth direction D5, and by engineering the beam tilting diffusor 5 to tilt the incoming light beam 9 or 28 in an angle corresponding to the angle between the first direction DI and the fifth direction D5.

[0140] Furthermore, the light generation system further 106 comprises a third beam focusing element 23. The third beam focusing element 23 is arranged between the first laser light source 2 and the beam tilting diffusor 5, or if a first beam homogenizer 15 is provided as shown in Fig. 8 between the first beam homogenizer 15 and the beam tilting diffusor 5. The third beam focusing element 23 is arranged and configured to focus the first light beam 9, or if a first beam homogenizer 15 is provided as shown in Fig. 8 the homogenized first light beam 28, onto the beam tilting diffusor 5. The third beam focusing element 23 may for instance be a lens or an array of lenses. In this embodiment, it is also feasible that the third beam focusing element 23 may be configured to undertake a part of the tilting if the first light beam 9, or the homogenized first light beam 28, from the first direction DI towards the fifth direction D5, while the beam tilting diffusor 5 is arranged and configured to complete the tilting if the first light beam 9, or the homogenized first light beam 28, from the first direction DI towards the fifth direction D5.

[0141] The light generation system 106 may further comprise a fourth beam focusing element 14. The fourth beam focusing element 14 is arranged between the beam tilting diffusor 5 and the dichroic reflecting unit 6. The fourth beam focusing element 14 is arranged and configured to de-focus or collimate the diffused first light beam 25. The fourth beam focusing element 14 may for instance be a lens or an array of lenses. The first to seventh directions, D1-D7, used herein may generally be defined as follows. The first direction, DI, is the direction of emission of the first light beam 9. The second direction, D2, is the direction of propagation of the diffused first light beam 25 generated by the beam tilting diffusor 5. The third direction, D3, is the direction of emission of the second light beam 10. The third direction, D3, is also the direction of propagation of the first light beam 10, or the homogenized first light beam 11, when transmitted by the dichroic reflecting unit 6 towards the wavelength conversion unit 4. The fourth direction, D4, is the direction of emission of the converted light beam 12 when reflected from the wavelength conversion unit 4. The fifth direction, D5, is the direction of propagation of the added light beam and where a reflection of the diffused light 25 is provided for of the reflected diffused light beam 25. The sixth direction, D6, is the direction of propagation of the part 91 of the first light beam 9 after reflection by the partially reflecting unit 17. The seventh direction, D7, is the direction of emission of the converted light beam 12 when the second light beam 10 is transmitted through the wavelength conversion unit 4 and converted during the transmission. The eighth direction, D8, is the direction of propagation of the first light beam 10, or the homogenized first light beam 11, when reflected by the dichroic reflecting unit 6 towards the wavelength conversion unit 4.

[0142] The first direction, DI, and the third direction, D3, may be mutually parallel. The third direction, D3, and the fourth direction, D4, may be mutually opposite directions. The second direction, D2, and the fifth direction, D5, may be the same direction. The second direction, D2, and the fifth direction, D5, may alternatively be mutually different directions. The third direction, D3, may be perpendicular to the first direction, DI, and the fourth direction, D4.

[0143] Referring now to Figs. 11A to 12B, the light generation system may further comprise an optional beam dump 32. The beam dump 32 is generally arranged and configured to absorb parts or rays of the first light beam 9 propagating past the beam tilting diffusor 5. In other words, the beam dump 32 is generally arranged and configured to absorb parts or rays of the first light beam 9 not being transmitted, diffused, and tilted by the beam tilting diffusor 5. Fig. 10A illustrates schematically the placement of a beam dump 32 of a light generation system in which the direction DI and the first main surface 53 of the beam tilting diffusor 5 forms a right angle with one another. Fig. 11A illustrates schematically the placement of a beam dump 32 of a light generation system in which the direction DI and the first main surface 53 of the beam tilting diffusor 5 forms a right angle with one another. Where a fourth beam focusing element 14 is provided, the beam dump 32 may also be arranged and configured to absorb and parts or rays of the diffused light beam 25 propagating past the fourth beam focusing element 14. In other words, the beam dump 32 may further be arranged and configured to absorb and parts or rays of the diffused light beam 25 not being collimated by the fourth beam focusing element 14.

[0144] Fig. 10B illustrates schematically the placement of a beam dump 32 of a light generation system comprising a fourth beam focusing element 14 and in which the direction DI and the first main surface 53 of the beam tilting diffusor 5 forms a right angle with one another. Fig. 1 IB illustrates schematically the placement of a beam dump 32 of a light generation system comprising a fourth beam focusing element 14 and in which the direction DI and the first main surface 53 of the beam tilting diffusor 5 forms a right angle with one another.

[0145] 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.

[0146] Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage.

Claims

CLAIMS:

1. A light generation system (1) providing, in operation, system light, the light generating system comprising a first laser light source (2), a second laser light source (3), a wavelength conversion unit (4), a beam tilting diffusor (5), and a dichroic reflecting unit (6), wherein: the first laser light source (2) is configured to generate a first light beam (9) being first blue laser light, the first light beam being emitted in and having a main optical axis extending in a first direction (DI), the beam tilting diffusor (5) is configured to transmit, diffuse, and tilt by a tilting angle (P) the first light beam (9) into a diffused first light beam (25) propagating in and having a main optical axis extending in a second direction (D2), the second direction (D2) being different from the first direction (DI) and extending in the tilting angle ( ) with the first direction, the second laser light source (3) is configured to generate a second light beam (10) being second blue laser light, the second light beam being emitted in and having a main optical axis extending in a third direction (D3), the wavelength conversion unit (4) being configured to convert the second light beam (11) into a converted light beam (12), the converted light beam being emitted in a fourth direction (D4), the wavelength conversion unit (4) comprises a wavelength conversion member (29) and a heat sink element (30) arranged in thermal contact with the wavelength conversion member, and the dichroic reflecting unit (6) being arranged downstream of the beam tilting diffusor (5) and downstream the wavelength conversion unit (4) such as to receive both the diffused first light beam (25) and the converted light beam (12), the dichroic reflecting unit (6) being configured to transmit the diffused first light beam (25) in a fifth direction (D5), and reflect the converted light beam (12) in the fifth direction (D5), or the dichroic reflecting unit (6) being arranged downstream of the beam tilting diffusor (5) and downstream the wavelength conversion unit (4) such as to receive both the diffused first light beam (25) and the converted light beam (12), the dichroic reflecting unit(6) being configured to transmit the converted light beam (12) in a fifth direction (D5) and reflect the diffused first light beam (25) in the fifth direction (D5).

2. A light generation system according to claim 1, wherein the first direction (DI) is arranged under an angle (9) with respect to the first main surface (53) of the beam tilting diffusor (5), wherein the angle (9) is in a range from 29 to 99 degrees.

3. A light generation system according to claim 1, wherein the second direction (D2) is arranged under an angle (y) with respect to a second main surface (54) opposite to the first main surface (53) of the beam tilting diffusor (5), wherein the angle (y) is in a range from 29 to 99 degrees.

4. A light generation system according to any one of the preceding claims, wherein the beam tilting diffusor (5) comprises a first optical element (51) configured to redirect at least part of the first light beam, the first optical element being at least one of: a refractive optical element, an array of non-symmetric microprisms, a prismatic sawtooth structure, or a plurality of non-spherical lenslets; and a diffractive optical element, a phase grating, a ruled grating, or a holographic optical element.

5. A light generation system according to any one of the preceding claims, wherein the beam tilting diffusor (5) comprises a second optical element (52) being a light scattering optical element, a volume scatterer or a surface scatterer or surface relief element.

6. A light generation system according to claims 4 and 5, wherein the beam tilting diffusor (5) comprises one of: a combination of (i) the first optical element (51), and (ii) the second optical element (52), the second optical element (52) being arranged downstream the first optical element (51), and a combination of (i) the second optical element (52), and (ii) the first optical element (51), the first optical element (51) being arranged downstream the second optical element (52).

7. A light generation system according to any one of the preceding claims, wherein one of the following applies: wherein the light generation system further comprising a further dichroic reflecting unit (31) arranged upstream of the dichroic reflecting unit (6), the further dichroic reflecting unit (31) being configured to (i) transmit the second light beam (11), and reflect the converted light beam (12), or (ii) reflect the second light beam (11), and transmit the converted light beam (12); the dichroic reflecting unit (6) being configured to reflect the diffused first light beam (25) in the fifth direction (D5) and transmit the converted light beam (12) in the fifth direction (D5) such that the diffused first light beam (25) and the converted light beam (12) are merged to an added light beam (26), the added light beam forming the system light.

8. A light generation system according to any one of claims 1-6, wherein the dichroic reflecting unit (6) is arranged downstream of the beam tilting diffusor (5) such as to receive both the diffused first light beam (25) and the converted light beam (12), the dichroic reflecting unit (6) being configured to transmit the diffused first light beam (25) in a fifth direction (D5), and reflect the converted light beam (12) in the fifth direction (D5), and wherein: the second direction (D2) and the fifth direction (D5) is the same direction, or the second direction (D2) and the fifth direction (D5) are mutually different directions, and the light generation system further comprises at least one reflecting unit (7), the at least one reflecting unit (7) being configured to reflect the diffused first light beam (25) in the fifth direction (D5).

9. A light generation system according to any one of the preceding claims, and further comprising a first beam focusing element (13) arranged between the second laser light source (3) and the wavelength conversion unit (4), the first beam focusing element (13) being configured to focus the second light beam (11) onto the wavelength conversion unit (4) and to collimate the converted light beam (12).

10. A light generation system according to any one of the preceding claims, wherein: the wavelength conversion member (4) comprising a luminescent material of the type AsBsOn 'e. wherein A denotes one or more of Y, La, Gd, Tb and Lu, especially (atleast) one or more of Y, Gd, Tb and Lu, and wherein B denotes one or more of Al, Ga, In and Sc; and wherein the wavelength conversion unit (4) is configured to generate a converted light beam (12) having a peak emission wavelength in a wavelength range from 500 nm to 580 nm.

11. A light generation system according to any one of the preceding claims, and further comprising one or more of: a first beam homogenizer (15) being configured to homogenize the first light beam (9) into a homogenized first light beam (28), a second beam homogenizer (8) being configured to homogenize the second light beam (10) into a homogenized second light beam (11), and a third beam homogenizer (16) being configured to homogenize the added light beam (26) into a homogenized added light beam (27).

12. A light generation system according to any one of the preceding claims, and further comprising: a partially reflecting unit (17) arranged between the first laser source (2) and the beam tilting diffusor (5) and configured to reflect a part (91) of the first light beam (9) in a sixth direction (D6) towards the second light beam (10), and a beam combining unit (18) arranged between the second laser source (3) and the dichroic reflecting unit (6) and configured to combine the part (91) of the first light beam (9) and the second light beam (10).

13. A light generation system according to any one of the preceding claims, and further comprising: a third beam focusing element (23) arranged between the first laser light source (2) and the beam tilting diffusor (5), the third beam focusing element (23) being configured to focus the first light beam (9) onto the beam tilting diffusor (5); and a fourth beam focusing element (14) arranged downstream of the beam tilting diffusor (5), the fourth beam focusing element (14) being configured to collimate the diffused first light beam (25).

14. A light generation system according to any one of the preceding claims, and further comprising a beam dump (32) configured to absorb at least parts of the first light beam (9) propagating past the beam tilting diffusor (5) and / or parts of the diffused light beam (25) propagating past the fourth beam focusing element (14).

15. A lamp or a luminaire comprising a light generation system according to any one of the preceding claims; and the lamp or the luminaire providing system light comprising the diffused first light beam and the converted second light beam, wherein the system light is white light having a correlated color temperature in a range from 2700 K to 9000 K and a CRI of at least 70.

Images