Phosphor wheel and light-emitting device

Abstract

This transmissive-type phosphor wheel (1B) comprises: a phosphor substrate (10B) which is an annular substrate composed of a phosphor material; a metal member (20B) which holds the phosphor substrate (10B); and a rotary part which rotates the phosphor substrate (10B) and the metal member (20B) about an axis extending in the thickness direction of the phosphor substrate (10B). When the phosphor substrate (10B) is viewed in a plan view, the phosphor substrate (10B) has an annular region which does not overlap the metal member (20B), and the metal member (20B) is composed of: a first heat dissipation member (23B) disposed on the main surface side of the phosphor substrate (10B); and a second heat dissipation member (24B) disposed on the side opposite the main surface of the phosphor substrate (10B). The first heat dissipation member (23B) and the second heat dissipation member (24B) sandwich and hold the phosphor substrate (10B), and a plurality of heat dissipation fins (202) are provided to one among the first heat dissipation member (23B) and the second heat dissipation member (24B).

Description

Technical Field

[0001] The present invention relates to a phosphor wheel and a light emitting device.

Background Art

[0002] Conventionally, a transmissive fluorescence emission module (phosphor wheel) that is excited by excitation light to generate fluorescence has been known. The transmissive fluorescence emission module is applied to, for example, a light emitting device such as a projector.

[0003] As an example of the transmissive fluorescence emission module, Patent Document 1 discloses a light source device. This light source device (transmissive fluorescence emission module) includes a phosphor substrate composed of a plate-shaped glass member, a fluorescence generation unit, a dichroic film positioned between the phosphor substrate and the fluorescence emission unit, and a light emission unit that emits excitation light for exciting the fluorescence generation unit.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, it is known that when the temperature of the fluorescence generation unit increases due to irradiation with excitation light, a phenomenon (so-called temperature quenching phenomenon) occurs in which the generated fluorescence decreases. For example, in the transmissive fluorescence emission module disclosed in Patent Document 1, since the heat dissipation property of the fluorescence generation unit is not sufficient, the temperature quenching phenomenon easily occurs, and as a result, the fluorescence emitted from the fluorescence emission unit decreases. Therefore, in such a transmissive fluorescence emission module, the light utilization efficiency may be lowered.

[0006] Furthermore, there is also a risk that the phosphor substrate may be damaged due to the thermal stress generated in the phosphor substrate by irradiation with excitation light.

[0007] Therefore, the present invention provides a phosphor wheel and a light-emitting device that can suppress the risk of damage due to thermal stress.

Means for Solving the Problems

[0008] A phosphor wheel according to an aspect of the present invention is a transmissive phosphor wheel, and includes a phosphor substrate that is an annular substrate made of a phosphor material, a metal member that holds the phosphor substrate, and a rotating unit that rotates the phosphor substrate and the metal member about an axis extending in the thickness direction of the phosphor substrate. When the phosphor substrate is viewed in plan view, the phosphor substrate has an annular region that does not overlap with the metal member. The metal member includes a first heat radiating member disposed on the main surface side of the phosphor substrate and a second heat radiating member disposed on the opposite side of the main surface of the phosphor substrate. The first heat radiating member and the second heat radiating member hold the phosphor substrate by sandwiching the phosphor substrate therebetween, and a plurality of heat radiating fins are provided on one of the first heat radiating member and the second heat radiating member.

Effects of the Invention

[0009] According to the present invention, it is possible to provide a phosphor wheel and a light-emitting device with high light utilization efficiency.

Brief Description of the Drawings

[0010]

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Mode for Carrying Out the Invention

[0011] Hereinafter, a transmissive fluorescence emission module and the like according to an embodiment of the present invention will be described in detail with reference to the drawings.

[0012] In addition, each of the embodiments described below shows comprehensive or specific examples. Numerical values, shapes, materials, components, arrangement positions and connection forms of components, manufacturing processes, order of manufacturing processes, etc. shown in the following embodiments are examples, and are not intended to limit the present invention.

[0013] Also, each figure is a schematic diagram and is not necessarily drawn precisely. Therefore, for example, scales and the like do not necessarily match in each figure. Also, in each figure, substantially the same configuration is denoted by the same reference numeral, and overlapping descriptions are omitted or simplified.

[0014] In this specification, terms indicating the relationship between elements such as parallel or orthogonal, terms indicating the shape of elements such as circular shape, and numerical ranges are not expressions representing only a strict meaning, but are expressions meaning ranges that are substantially equivalent, for example, including differences of about several percent.

[0015] Also, in this specification and the drawings, the x-axis, y-axis, and z-axis indicate the three axes of a three-dimensional orthogonal coordinate system. In the embodiment, two axes parallel to the third main surface of the phosphor substrate are the x-axis and y-axis, and an axis orthogonal to the x-axis and y-axis is the z-axis.

[0016] (Embodiment 1) [Configuration] First, the configuration of the transmissive fluorescence emission module 1 according to this embodiment will be described with reference to the drawings. FIG. 1A is a perspective view of the transmissive fluorescence emission module 1 according to this embodiment. FIG. 1B is an exploded perspective view of the transmissive fluorescence emission module 1 according to this embodiment.

[0017] As shown in FIGS. 1A and 1B, the transmissive fluorescence emission module 1 is a module including a phosphor substrate 10 made of a phosphor material, a metal member 20, a rotating portion 30, and two light emitting portions 200. For simplicity, in FIGS. 1A and 1B, one light emitting portion 200 is shown. The same may be described in the following figures. Also, the transmissive fluorescence emission module 1 may include one light emitting portion 200. The transmissive fluorescence emission module 1 is used, as an example, in a light emitting device typified by a projector and a lighting device. In this embodiment, the transmissive fluorescence emission module 1 is used in a projector.

[0018] In this embodiment, the rotating portion 30 rotates the phosphor substrate 10 and the like in the direction of the arrow R shown in FIG. 1A around the axis B1, and further, the phosphor substrate 10 receives the excitation light L1 and emits transmitted light L2 including fluorescence. The transmissive fluorescence emission module 1 is a light transmissive module that uses the transmitted light L2 as projection light output by the projector. That is, the phosphor substrate 10 is used as a light transmissive phosphor wheel.

[0019] The components included in the transmissive fluorescence emission module 1 will be described below.

[0020] First, the light emitting unit 200 will be described.

[0021] The light emitting unit 200 is a light source that emits excitation light L1. The excitation light L1 is light that excites the phosphor material constituting the phosphor substrate 10. The light emitting unit 200 is, for example, a semiconductor laser light source or an LED (Light Emitting Diode) light source, and is driven by a drive current to emit excitation light L1 of a predetermined color (wavelength).

[0022] In the present embodiment, the light emitting unit 200 is a semiconductor laser light source. The semiconductor laser element included in the light emitting unit 200 is, for example, a GaN-based semiconductor laser element (laser chip) composed of a nitride semiconductor material. In the present embodiment, the light emitting unit 200, which is a semiconductor laser light source, is a light emitting device of a collimating lens integrated TO-CAN type. Note that the light emitting unit 200 may be a multi-chip type laser as shown in JP-A-2016-219779, or the collimating lens and the TO-CAN may be separate.

[0023] As an example, the light emitting unit 200 emits laser light within the range from near ultraviolet to blue having a peak wavelength in the range of 380 nm or more and 490 nm or less as the excitation light L1. At this time, the peak wavelength of the excitation light L1 is, for example, 455 nm, and the excitation light L1 is blue light.

[0024] Next, the phosphor substrate 10 will be described.

[0025] The phosphor substrate 10 is a flat substrate having two main surfaces facing each other. The two main surfaces are the third main surface 11 and the fourth main surface 12. The third main surface 11 and the fourth main surface 12 are planes here.

[0026] Furthermore, the phosphor substrate 10 will be described in detail with reference to FIGS. 2 and 3.

[0027] FIG. 2 is a plan view of the phosphor substrate 10, the metal member 20, and the rotating portion 30 according to the present embodiment. In FIG. 2, the light emitting portion 200 is omitted. FIG. 3 is a bottom view of the phosphor substrate 10 and the metal member 20 according to the present embodiment. In FIG. 3, the rotating portion 30 and the light emitting portion 200 are omitted. Here, the plan view is a view of the transmissive fluorescent emission module 1 seen from the negative z-axis direction, and the bottom view is a view of the transmissive fluorescent emission module 1 seen from the positive z-axis direction. Also, the viewpoint in the plan view is the plan view, and the viewpoint in the bottom view is the bottom view.

[0028] The phosphor substrate 10 is a substrate having a circular shape in plan view, that is, a disk shape. Here, the center of the circular shape of the phosphor substrate 10 is defined as the center point C1. Furthermore, since the phosphor substrate 10 is provided with a first through hole H1, more specifically, the shape of the phosphor substrate 10 is an annular shape. The first through hole H1 is a hole that penetrates the phosphor substrate 10 in the thickness direction (z-axis direction) of the phosphor substrate 10 and is a circular hole in plan view. The center of the circular shape of the first through hole H1 coincides with the center point C1. That is, the phosphor substrate 10 is provided in a circular ring shape on a circumference having an equal distance from the center point C1 of the phosphor substrate 10 and is provided in a belt shape along the circumferential direction in plan view.

[0029] The outer diameter of the phosphor substrate 10 having an annular shape (that is, the diameter of the outer circle in the bottom view of FIG. 3) is preferably, for example, 30 mm or more and 90 mm or less, more preferably 35 mm or more and 70 mm or less, and even more preferably 40 mm or more and 50 mm or less, but is not limited thereto. When the transmissive fluorescent emission module 1 is applied to a projector, the outer diameter of the phosphor substrate 10 is determined so as to fit into the housing of the projector.

[0030] Also, the inner diameter of the phosphor substrate 10 (that is, the diameter of the inner circle in the bottom view of FIG. 3) is smaller than the outer diameter of the phosphor substrate 10, and is preferably 15 mm or more and 45 mm or less as an example, more preferably 17.5 mm or more and 35 mm or less, and even more preferably 20 mm or more and 25 mm or less, but is not limited thereto. Also, the inner diameter of the phosphor substrate 10 is also the diameter of the first through hole H1.

[0031] The thickness of the phosphor substrate 10 (that is, the length in the z-axis direction) is preferably 50 μm or more and 700 μm or less. The thickness of the phosphor substrate 10 is more preferably 80 μm or more and 500 μm or less, and even more preferably 100 μm or more and 300 μm or less.

[0032] The phosphor substrate 10 is composed of a phosphor material. That is, the phosphor substrate 10 is a member composed only of the phosphor material as the main component. More specifically, the phosphor substrate 10 is a substrate composed of a sintered phosphor composed only of the phosphor material.

[0033] Here, the sintered phosphor in this specification will be described.

[0034] The sintered phosphor is a fired body in which the raw material powder of the phosphor material (as an example, the granulated body obtained by granulating the raw material powder of the phosphor material), which is the main component described above, is fired at a temperature lower than the melting point of the phosphor material. Also, in the sintered phosphor, the raw material powders are bonded to each other during the firing process. Therefore, the sintered phosphor hardly requires a binder for bonding the granulated bodies. More specifically, the sintered phosphor does not require any binder at all. The binder is, for example, a transparent resin in Patent Document 1 described above. Also, the binder is a material such as an Al2O3 material and a glass material (that is, SiO d (0 < d ≤ 2)) and the like are used as known materials. Similarly, not limited to the binder, the sintered phosphor hardly requires materials other than the phosphor material that the sintered phosphor has (hereinafter referred to as other materials), and more specifically, does not require any other materials at all.

[0035] For example, when the total volume of the sintered phosphor is 100 vol%, the volume of the phosphor material in the total volume of the sintered phosphor is preferably 70 vol% or more. Further, it is more preferable that the volume of the phosphor material in the total volume of the sintered phosphor is 80 vol% or more, even more preferably 90 vol% or more, and even more preferably 95 vol% or more.

[0036] In other words, when the total volume of the sintered phosphor is 100 vol%, the volume of other materials (such as a binder) in the total volume of the sintered phosphor is preferably less than 30 vol%. Further, it is more preferable that the volume of other materials (such as a binder) in the total volume of the sintered phosphor is 20 vol% or less, even more preferably 10 vol% or less, and even more preferably 5 vol% or less.

[0037] When the vol% of other materials in the total volume of the sintered phosphor is high (that is, the proportion of the volume of other materials is large), phonon scattering occurs due to defects existing at the interface between the phosphor material and other materials. As a result, the thermal conductivity of the sintered phosphor decreases. In particular, when the volume of other materials is 30 vol% or more, the decrease in thermal conductivity is significant. Also, non-radiative recombination at the above interface increases, and the luminous efficiency decreases. In other words, the lower the vol% of other materials in the total volume of the sintered phosphor (that is, the smaller the proportion of the volume of other materials), the higher the thermal conductivity and the luminous efficiency. For the above reasons, the sintered phosphor of the present invention has a volume of other materials in the total volume of the sintered phosphor of less than 30%.

[0038] Here, the phosphor material will be described.

[0039] The phosphor material is, for example, a material composed of a crystal phase having a garnet structure. The garnet structure is A3B2C3O 12It has a crystal structure represented by the general formula. As the element A, rare earth elements such as Ca, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, and Lu are applicable. As the element B, elements such as Mg, Al, Si, Ga, and Sc are applicable. As the element C, elements such as Al, Si, and Ga are applicable. Such garnet structures include YAG (Yttrium Aluminum Garnet), LuAG (Lutetium Aluminum Garnet), Lu2CaMg2Si3O 12 (Lutetium Calcium Magnesium Silicon Garnet) and TAG (Terbium Aluminum Garnet), etc. In this embodiment, the phosphor material is (Y 1-x Ce x )3Al2Al3O 12 (that is, (Y 1-x Ce x )3Al5O 12 )(0.0001 ≦ x < 0.1), that is, it is composed of YAG, a crystal phase represented by

[0040] Also, when the phosphor material is composed of YAG, Al2O3 may be used as a raw material. In this case, in the sintered phosphor, Al2O3 may remain as an unreacted raw material. However, the unreacted raw material Al2O3 is different from the above binder. Also, when the total volume of the sintered phosphor is 100 vol%, the volume of Al2O3, which is the unreacted raw material, in the total volume of the sintered phosphor is 5 vol% or less.

[0041] Note that the crystal phase constituting the phosphor material may be a solid solution of a plurality of garnet crystal phases with different chemical compositions. Such solid solutions include (Y 1-x Ce x )3Al2Al3O 12 (0.001 ≦ x < 0.1) and a garnet crystal phase represented by (Lu 1-y Cey ) 3Al2Al3O 12 (0.001 ≦ y < 0.1) represented by a garnet crystal phase solid solution ((1 - a)(Y 1-x Ce x ) 3Al5O 12 ·a(Lu 1-y Ce y ) 3Al2Al3O 12 (0 < a < 1)) can be mentioned. Also, as such a solid solution, (Y 1-x Ce x ) 3Al2Al3O 12 (0.001 ≦ x < 0.1) represented by a garnet crystal phase and (Lu 1-z Ce z ) 2CaMg2Si3O 12 (0.0015 ≦ z < 0.15) represented by a garnet crystal phase solid solution ((1 - b)(Y 1-x Ce x ) 3Al2Al3O 12 ·b(Lu 1-z Ce z ) 2CaMg2Si3O 12 (0 < b < 1)) etc. can be mentioned. By the phosphor material being composed of a solid solution of a plurality of garnet crystal phases with different chemical compositions, the fluorescence spectrum of the fluorescence emitted by the phosphor material becomes broader, and the green light component and the red light component increase. Therefore, a projector that emits projection light with a wide color gamut can be provided.

[0042] Also, the crystal phase constituting the phosphor material may include a crystal phase with a chemical composition shift with respect to the crystal phase represented by the above general formula A3B2C3O 12 . As such a crystal phase, for the crystal phase represented by (Y 1-x Ce x ) 3Al2Al3O 12 (0.001 ≦ x < 0.1), Al-rich (Y 1-x Ce x ) 3Al 2+δ Al3O 12 (δ is a positive number) can be mentioned. Also, as such a crystal phase, for (Y 1-x Ce x ) 3Al2Al3O 12(0.001 ≦ x < 0.1) represented crystal phase is rich in Y (Y 1-x Ce x ) 3+ζ Al2Al3O 12 (ζ is a positive number), etc. These crystal phases have a chemical composition deviation from the crystal phase represented by the general formula A3B2C3O 12 but maintain the garnet structure.

[0043] Furthermore, the crystal phase constituting the phosphor material may include heterogeneous phases having structures other than the garnet structure.

[0044] Also, when viewed in plan view, the phosphor substrate 10 has an annular region A1 that does not overlap with the metal member 20. In each of FIGS. 1B, 2, and 3, the region A1 corresponds to the region between the two circles indicated by the dashed-dotted line. The center of the annular shape of the region A1 overlaps with the center point C1 of the phosphor substrate 10. Further, excitation light L1 is incident on the region A1. More specifically, the excitation light L1 emitted from the light emitting portion 200 is incident on the region A1 from the third main surface 11 side (that is, the negative z-axis side).

[0045] In the region A1 of the phosphor substrate 10, the phosphor material made of YAG receives the excitation light L1 and emits fluorescence. More specifically, when the excitation light L1 irradiates the phosphor material, fluorescence is emitted from the phosphor material as wavelength-converted light. That is, the wavelength-converted light emitted from the phosphor material is light having a wavelength longer than that of the excitation light L1.

[0046] In the present embodiment, the wavelength-converted light emitted from the phosphor material includes fluorescence that is yellow light. The phosphor material absorbs light having a wavelength of 380 nm or more and 490 nm or less, for example, and emits fluorescence that is yellow light having a fluorescence peak wavelength in the region of 490 nm or more and 580 nm or less. By configuring the phosphor material with YAG, it is possible to easily emit fluorescence having a fluorescence peak wavelength in the region of 490 nm or more and 580 nm or less.

[0047] In the present embodiment, as shown in FIG. 1A, a part of the incident excitation light L1 is wavelength-converted by the phosphor material, passes through the phosphor substrate 10, and is emitted from the fourth main surface 12 side. Further, the other part of the incident excitation light L1 is not wavelength-converted by the phosphor material, passes through the phosphor substrate 10, and is emitted from the fourth main surface 12 side. The transmitted light L2 that has passed through the phosphor substrate 10 includes fluorescence that is wavelength-converted yellow light and excitation light L1 that is non-wavelength-converted blue light. That is, the transmitted light L2 is light in which these lights are combined and is white light.

[0048] Further, the phosphor substrate 10 does not need to be supported by other components. That is, the phosphor substrate 10 has a rigid property. The phosphor substrate 10 is a sintered phosphor, and since the thickness of the phosphor substrate 10 is within the above range, the phosphor substrate 10 has a rigid property. Also, compared with a fluorescence generating portion formed of a paint containing a phosphor and a transparent resin disclosed in Patent Document 1, the phosphor substrate 10 according to the present embodiment has a much more rigid property.

[0049] Next, the metal member 20 will be described.

[0050] The metal member 20 is a component formed of a metal material. Also, the metal member 20 is a member provided by being joined to one main surface of the phosphor substrate 10. In the present embodiment, as shown in FIGS. 1A and 1B, the metal member 20 is located on the negative z-axis side of the phosphor substrate 10 and is provided by being joined to the third main surface 11. Although it will be described in detail later, as for the material of the metal member 20, Al which is lightweight and has high thermal conductivity is used in consideration of the load on the rotating portion 30 which is a motor and the thermal conductivity.

[0051] In this embodiment, the metal member 20 is joined to the third main surface 11 of the phosphor substrate 10 via a bonding layer. In this case, as the bonding layer, a silicone resin is used to mitigate the difference in the coefficient of thermal expansion between the rotating portion 30 and the phosphor substrate 10. However, the material of the rotating portion 30 may be other materials such as Cu or Fe, and the adhesive member may also be other epoxy resins or a highly thermally conductive adhesive containing nano Ag or nano Cu. Also, the thickness of the bonding layer may be 5 μm or more and 40 μm or less, and more preferably 10 μm or more and 20 μm or less. Note that the metal member 20 may have a structure in which it directly contacts the third main surface 11 of the phosphor substrate 10 without using an adhesive. In this case, the phosphor substrate 10 may be sandwiched between the metal member 20 and another member (not shown), and the metal member and the other member may be joined by bolts or screws. Note that in the case of the sandwich structure without using an adhesive, the other member may be made of metal from the viewpoint of heat dissipation, but may also be made of a resin material.

[0052] Furthermore, the metal member 20 according to this embodiment includes a main body portion 21 and a plurality of heat dissipation fins 22.

[0053] The main body portion 21 is a flat plate-shaped member provided so as to be laminated with the phosphor substrate 10. The main body portion 21 also has two main surfaces facing each other. The two main surfaces are a first main surface 211 and a second main surface 212. Here, the first main surface 211 and the second main surface 212 are planes parallel to each other. In this embodiment, the main body portion 21 is joined to the third main surface 11 of the phosphor substrate 10 via a bonding layer (not shown). More specifically, the first main surface 211 of the main body portion 21 is joined to the third main surface 11 of the phosphor substrate 10 via a bonding layer. Also, since the main body portion 21 has a flat plate shape, the area where the phosphor substrate 10 and the metal member 20 (here, the main body portion 21) are joined becomes wider. Also, the flat plate shape of the main body portion 21 is not limited to a rectangular parallelepiped shape, and also means a cylindrical shape, a frustum of a cone shape, and the like.

[0054] As shown in FIGS. 2 and 3, in plan view and bottom view, the shape of the main body portion 21 is circular. Also, the area of the first main surface 211 of the main body portion 21 is larger than the area of the second main surface 212 of the main body portion 21. That is, the shape of the main body portion 21 is a frustum of a cone shape. Further, the main body portion 21 having a frustum of a cone shape has a first side surface portion 213. The first side surface portion 213 is an inclined surface that extends from the second main surface 212 toward the first main surface 211. Also, the first side surface portion 213 that is an inclined surface is not parallel to the z-axis.

[0055] Further, since the second through hole H2 is provided in the main body portion 21, the shape of the main body portion 21 is a shape in which the second through hole H2 is provided in the frustum of a cone shape. Also, in plan view and bottom view, the shape of the main body portion 21 is an annular shape. The second through hole H2 is a hole that penetrates the main body portion 21 in the thickness direction (z-axis direction) of the phosphor substrate 10, and is a circular hole in plan view. The center of the annular shape that is the shape of the main body portion 21 overlaps with the center point C1 of the phosphor substrate 10.

[0056] The outer diameter of the main body portion 21 is smaller than the outer diameter of the phosphor substrate 10. Here, the outer diameter of the main body portion 21 means the diameter of the first main surface 211 of the main body portion 21. The outer diameter of the main body portion 21 is preferably, for example, 20 mm or more and 70 mm or less, more preferably 25 mm or more and 55 mm or less, and even more preferably 30 mm or more and 40 mm or less, but is not limited thereto. In the present embodiment, the outer diameter of the main body portion 21 is 34 mm, that is, the radius of the main body portion 21 is 17 mm.

[0057] Also, the inner diameter of the main body portion 21 only needs to be smaller than the outer diameter of the main body portion 21. Here, it is the same size as the inner diameter of the phosphor substrate 10, but is not limited thereto. Also, the inner diameter of the main body portion 21 is also the diameter of the second through hole H2.

[0058] In the present embodiment, as shown in FIGS. 2 and 3, in plan view and bottom view, a part of the first through-hole H1 and a part of the second through-hole H2 overlap. More specifically, when viewed in plan view, all of the first through-hole H1 and all of the second through-hole H2 overlap. That is, the diameter of the first through-hole H1 (inner diameter of the phosphor substrate 10) is equal to the diameter of the second through-hole H2 (inner diameter of the main body portion 21). Further, in plan view and bottom view, the circular center of the first through-hole H1 and the circular center of the second through-hole H2 overlap with the center point C1 of the phosphor substrate 10.

[0059] The transmissive fluorescent light-emitting module 1 according to the present embodiment includes a phosphor substrate 10 and a metal member 20. This metal member 20 is provided by being joined to the third main surface 11 of the phosphor substrate 10. Therefore, even when heat is generated in the phosphor substrate 10 by the irradiation of the excitation light L1, the heat easily moves from the phosphor substrate 10 to the metal member 20. Also, generally, the metal material constituting the metal member 20 has a higher thermal conductivity than a phosphor material such as YAG. Thereby, the heat easily moves through the metal member 20 and is easily radiated from the surface where the metal member 20 is exposed to the atmosphere. That is, by configuring the phosphor substrate 10 and the metal member 20 as described above, the heat is easily radiated from the phosphor substrate 10. That is, the heat dissipation property of the phosphor substrate 10 can be enhanced.

[0060] Here, the effects of the transmissive fluorescent light-emitting module 1 according to the present embodiment will be described.

[0061] As described above, in the transmissive fluorescent light-emitting module disclosed in Patent Document 1, when the temperature quenching phenomenon occurs, the light utilization efficiency becomes low. However, in the present embodiment, since the heat is easily radiated from the phosphor substrate 10, an increase in the temperature of the phosphor substrate 10 due to the irradiation of the excitation light L1 can be suppressed. Thereby, since the temperature quenching phenomenon hardly occurs, a decrease in fluorescence is suppressed.

[0062] Moreover, the transmissive fluorescence emission module 1 according to the present embodiment does not include components for supporting the phosphor substrate 10. Such components are, for example, the phosphor substrate disclosed in Patent Document 1. This phosphor substrate is a substrate composed of a plate-shaped glass member that supports a fluorescence generation portion and the like.

[0063] Here, the behavior of light disclosed in Patent Document 1 will be described. In Patent Document 1, it is disclosed that excitation light is incident from the atmosphere onto the phosphor substrate. Further, the excitation light incident on the phosphor substrate passes through the phosphor substrate and is incident on the fluorescence generation portion, and fluorescence is generated in the fluorescence generation portion. By the way, in Patent Document 1, due to the difference between the refractive index of this phosphor substrate and the refractive index of the atmosphere, a part of the excitation light incident on the phosphor substrate from the atmosphere is reflected toward the atmosphere side. That is, light loss of the excitation light occurs at the interface between the phosphor substrate and the atmosphere. As a result, since the excitation light incident on the fluorescence generation portion decreases compared to the case where a part of the excitation light is not reflected, the fluorescence generated in the fluorescence generation portion also decreases. That is, in the transmissive fluorescence emission module disclosed in Patent Document 1, there is a problem that the light utilization efficiency is low.

[0064] On the other hand, in the present embodiment, as described above, the transmissive fluorescence emission module 1 according to the present embodiment does not include components (for example, the above-described phosphor substrate) for supporting the phosphor substrate 10. Therefore, since there is no light loss of the excitation light L1 as described above, the excitation light L1 incident on the phosphor substrate 10 increases. As a result, the fluorescence generated by the phosphor material in the phosphor substrate 10 increases.

[0065] In summary, in the transmissive fluorescence emission module 1 according to the present embodiment, the temperature quenching phenomenon hardly occurs, and since there is no light loss of the excitation light L1, the light utilization efficiency can be improved.

[0066] Further, in the present embodiment, the metal member 20 has a main body portion 21.

[0067] Since the main body portion 21 has the above configuration, the area where the phosphor substrate 10 and the metal member 20 (here, the main body portion 21) are joined becomes wider. Therefore, even when heat is generated in the phosphor substrate 10 due to the irradiation of the excitation light L1, the heat is more easily dissipated from the phosphor substrate 10.

[0068] Here, the thickness D21 of the main body portion 21 will be described with reference to FIG. 4.

[0069] FIG. 4 is a cross-sectional view showing a partial cut surface of the transmissive fluorescence emission module 1 along the line IV-IV in FIG. 1A. In FIG. 4, a side view of the light emitting portion 200 is shown.

[0070] The thickness D21 (the length in the z-axis direction) of the main body portion 21 is preferably thicker than the thickness of the phosphor substrate 10. This is because the heat conductivity is improved. On the other hand, if the thickness of the phosphor substrate 10 becomes too thick, the load on the rotating portion 30, which is a motor, becomes high and the lifespan becomes short. Therefore, as an example, the thickness D21 of the main body portion 21 may be 0.2 mm or more and 50 mm or less, more preferably 0.5 mm or more and 10 mm or less, and even more preferably 1 mm or more and 5 mm or less. The thicker the thickness D21 of the main body portion 21, the easier it is for the heat to be dissipated from the phosphor substrate 10. On the other hand, the thinner the thickness D21 of the main body portion 21, the smaller the volume of the main body portion 21, that is, the weight of the main body portion 21 decreases. Therefore, the rotating portion 30 can rotate the phosphor substrate 10, etc. with less energy. Thus, the thickness D21 of the main body portion 21 is preferably within the above range.

[0071] Furthermore, the plurality of heat dissipation fins 22 of the metal member 20 will be described.

[0072] The plurality of heat dissipation fins 22 are projections standing upright in a direction opposite to the direction from the main body 21 toward the phosphor substrate 10. That is, the plurality of heat dissipation fins 22 are in contact with the main body 21 and are regions protruding in the negative z-axis direction. Further, in FIG. 4, the thickness D22 of the plurality of heat dissipation fins 22 is shown. Note that although the thickness D22 of each of the plurality of heat dissipation fins 22 is the same, it is not limited thereto. The thickness D22 is preferably greater than the thickness D21 of the main body 21. As an example, the thickness D22 may be 1 mm or more and 150 mm or less, more preferably 2 mm or more and 30 mm or less, and even more preferably 3 mm or more and 10 mm or less.

[0073] Note that the greater the thickness D22, the higher the heat dissipation effect. On the other hand, when the thickness D22 increases, the weight increases, and the load on the rotating part 30, which is a motor, increases. Also, in order to maintain the rigidity against rotation, it is necessary to increase the circumferential thickness of the plurality of heat dissipation fins 22. When the circumferential thickness of the plurality of heat dissipation fins 22 is thin, the thermal conductivity from the main body 21 becomes low, and as a result, the heat dissipation performance deteriorates. When the thickness D22 is 5 mm, the circumferential thickness of the plurality of heat dissipation fins 22 is preferably in the range of 0.2 mm or more and 3 mm or less, and more preferably in the range of 0.4 mm or more and 2 mm or less. Note that the circumferential thickness may vary, and the above range is the average value excluding the portions where the thickness has increased due to the influence of screwing or the like.

[0074] As shown in FIGS. 1A, 1B, 2, and 3, here, 12 heat dissipation fins 22 are provided. When viewed in plan, the 12 heat dissipation fins 22 are provided so as to extend radially. More specifically, the 12 heat dissipation fins 22 are arranged so as to extend radially with respect to the axis B1. That is, the 12 heat dissipation fins 22 have a shape that extends radially about the center point C1 of the phosphor substrate 10. The 12 heat dissipation fins 22 extend radially so as to spread at equal intervals about the center point C1.

[0075] For example, when n heat dissipation fins 22 are provided, "extending at equal intervals" means that the angle formed by the direction in which one heat dissipation fin 22 extends and the direction in which another heat dissipation fin 22 adjacent to the one heat dissipation fin 22 extends is 360°÷n. In FIG. 2, the direction D1 in which one heat dissipation fin 22 extends and the direction D2 in which another heat dissipation fin 22 adjacent to the one heat dissipation fin 22 extends are indicated by a dashed-dotted line. In the present embodiment, among the 12 heat dissipation fins 22, the angle formed by the direction D1 in which one heat dissipation fin 22 extends and the direction D2 in which the other heat dissipation fin 22 extends is 30°.

[0076] Here, 12 heat dissipation fins 22 are provided, but the present invention is not limited to this, and one or more heat dissipation fins 22 may be provided. Further, the plurality of heat dissipation fins 22 are not limited to the above, and may be arranged, for example, in a matrix shape or in an annular shape centered on the center point C1.

[0077] Furthermore, as shown in FIG. 3, in a bottom view, each of the plurality of heat dissipation fins 22 includes a region protruding toward the center point C1. The protruding regions included in each of the plurality of heat dissipation fins 22 protrude inside the circle inside the main body 21 and are provided at positions overlapping the second through-hole H2. In the present embodiment, since all of the first through-hole H1 and all of the second through-hole H2 overlap, the protruding regions included in each of the plurality of heat dissipation fins 22 are provided at positions overlapping the first through-hole H1 and the second through-hole H2.

[0078] Also, as shown in FIGS. 2 and 4, each of the plurality of heat dissipation fins 22 has a second side surface portion 221 at the position farthest from the axis B1. The second side surface portion 221 of each of the plurality of heat dissipation fins 22 is an inclined surface that extends in the positive z-axis direction. Further, the second side surface portion 221 that is an inclined surface is not parallel to the z-axis. Furthermore, the second side surface portion 221 and the first side surface portion 213 of the main body 21 are connected flush. Also, the second side surface portion 221 and the first side surface portion 213 are parallel to each other at the connection location.

[0079] Since the metal member 20 has a plurality of heat dissipation fins 22, the surface area of the metal member 20 increases, so that heat is more easily released from the metal member 20. As a result, the heat generated in the phosphor substrate 10 by the irradiation of the excitation light L1 is more easily dissipated from the phosphor substrate 10.

[0080] Also, in the present embodiment, the metal member 20 is made of Al. Al is a metal material having a high thermal conductivity, and the thermal conductivity of Al is 237 W / m·K. The thermal conductivity of YAG constituting the phosphor material is 11.2 W / m·K. Therefore, since the metal member 20 is made of Al, the heat dissipation property of the phosphor substrate 10 can be further enhanced.

[0081] Note that the metal member 20 may be made of other than Al or Cu, and for example, it may be made of one or more metal elements or alloys selected from Ni, Pd, Rh, Mo, W, and Cu. The thermal conductivity of each element is 83 W / m·K for Ni, 73 W / m·K for Pd, 150 W / m·K for Rh, 135 W / m·K for Mo, 163 W / m·K for W, and 395 W / m·K for Cu. Therefore, since the metal member 20 is made of these metal materials, the heat dissipation property of the phosphor substrate 10 can be further enhanced.

[0082] Next, the rotating part 30 will be described.

[0083] The rotating part 30 is located on the negative z-axis side of the metal member 20. That is, the metal member 20 is located between the rotating part 30 and the phosphor substrate 10. Here, the rotating part 30 is joined to the metal member 20. Also, as shown in FIG. 2, in plan view, the rotating part 30 is provided at a position overlapping the phosphor substrate 10.

[0084] The rotating part 30 is a member that rotates the phosphor substrate 10 and the metal member 20 around an axis B1 extending in the thickness direction (z-axis direction) of the phosphor substrate 10, and is, for example, a motor. More specifically, in the present embodiment, the rotating part 30 rotates the phosphor substrate 10 and the metal member 20 in the direction of the arrow R shown in FIG. 1A around the axis B1. Note that the rotating part 30 may rotate the phosphor substrate 10 and the metal member 20 in a direction opposite to the direction of the arrow R shown in FIG. 1A. As shown in FIG. 1B, the axis B1 is an axis passing through the center point C1 of the phosphor substrate 10.

[0085] In addition, the rotating part 30 has a disk part 31 and a rotating shaft having the axis B1 as its axis. The disk part 31 has a circular shape in plan view and is a flat plate-shaped member as shown in FIG. 2. The diameter of the disk part 31 is the same as the diameter of the main body part 21 of the metal member 20.

[0086] As described above, the rotating part 30 is joined to the metal member 20. More specifically, the disk part 31 is joined to a plurality of heat radiation fins 22 of the metal member 20. As shown in FIG. 2, the disk part 31 is arranged so as to cover the negative z-axis side of the metal member 20.

[0087] The disk part 31 and the plurality of heat radiation fins 22 may be joined by bolts or screws, etc. Also, in the present embodiment, the disk part 31 is joined to the plurality of heat radiation fins 22 via a joining layer. In this case, as an example, the same joining layer as the joining layer that joins the metal member 20 and the phosphor substrate 10 is used.

[0088] Thus, the transmissive fluorescence emission module 1 according to the present embodiment includes the rotating part 30. Thereby, since the phosphor substrate 10 etc. rotate around the axis B1, an air flow is generated. The generated air flow cools the phosphor substrate 10. Thereby, even when the excitation light L1 is irradiated, an increase in the temperature of the phosphor substrate 10 can be suppressed, so that a temperature quenching phenomenon hardly occurs and a decrease in fluorescence is suppressed. That is, the light utilization efficiency of the transmissive fluorescence emission module 1 can be increased.

[0089] Also, as described above, in the present embodiment, the heat dissipation fins 22 of the metal member 20 are provided so as to extend radially. Therefore, when the phosphor substrate 10 or the like is rotated by the rotating portion 30, a strong air flow with a higher flow velocity is generated.

[0090] Furthermore, in the present embodiment, the first through hole H1 and the second through hole H2 are provided so as to overlap each other. For this reason, when the phosphor substrate 10 or the like is rotated by the rotating portion 30, a stronger air flow with an even higher flow velocity is generated.

[0091] In FIG. 1A, an example of the air flow is shown by a dashed-dotted arrow. That is, the air flow sequentially passes between the first through hole H1, the second through hole H2, and the plurality of heat dissipation fins 22 and heads toward the region A1 of the phosphor substrate 10. As a result, the heat generated in the region A1 by the irradiation of the excitation light L1 is cooled by the air flow, so that the temperature rise of the phosphor substrate 10 is suppressed. That is, by providing the heat dissipation fins 22 of the metal member 20 so as to extend radially, the heat dissipation property of the transmissive fluorescence emission module 1 can be further enhanced. And further, by providing the first through hole H1 and the second through hole H2 so as to overlap each other, a stronger air flow with an even higher flow velocity is generated. Therefore, the temperature rise of the phosphor substrate 10 is further suppressed.

[0092] Also, as described above, each of the plurality of heat dissipation fins 22 includes a region protruding toward the center point C1. For this reason, the air flow easily passes between the first through hole H1, the second through hole H2, and the plurality of heat dissipation fins 22. Therefore, an air flow with an even higher flow velocity is generated, and the temperature rise of the phosphor substrate 10 is further suppressed.

[0093] Here, in the present embodiment, the disk portion 31 is arranged so as to cover the metal member 20. For this reason, when the phosphor substrate 10 or the like is rotated by the rotating portion 30, the generated air flow easily heads toward the region A1, and the temperature rise of the phosphor substrate 10 is further suppressed.

[0094] In addition, in the present embodiment, a plurality of heat dissipation fins 22 are provided between the main body 21 and the disk part 31. In this case, a gap is provided between one heat dissipation fin 22 and another heat dissipation fin 22 adjacent to the one heat dissipation fin 22. That is to say, by providing this gap, the metal member 20 is lightened. Therefore, the rotating part 30 can rotate the phosphor substrate 10 and the metal member 20 with less energy.

[0095] [Configuration of Projector] The transmissive fluorescent light emitting module 1 configured as described above is used in the projector 500 shown in FIG. 5. FIG. 5 is a perspective view showing the appearance of the projector 500 according to the present embodiment. FIG. 6 is a schematic diagram showing the transmissive fluorescent light emitting module 1 in the projector 500 according to the present embodiment. Hereinafter, the configuration of the projector 500 according to the present embodiment will be described with reference to FIG. 6.

[0096] As shown in FIG. 6, the projector 500 according to the present embodiment includes a transmissive fluorescent light emitting module 1. The projector 500 also includes a housing 300, a first optical element 301, a second optical element 302, a third optical element 303, a fourth optical element 304, and a display element (not shown).

[0097] The housing 300 is a metal case that houses the phosphor substrate 10, the metal member 20, the rotating part 30, the first optical element 301, the second optical element 302, and the fourth optical element 304. The housing 300 houses a part of each of the two light emitting parts 200 and a part of the third optical element 303. The internal space of the housing 300 is a closed space. Therefore, the phosphor substrate 10, the metal member 20, the rotating part 30, the first optical element 301, the second optical element 302, and the fourth optical element 304 are protected by the housing 300 and are not easily contaminated by dust and dirt.

[0098] The first optical element 301, the second optical element 302, and the third optical element 303 are optical members for controlling the optical path of the transmitted light L2 output from the transmissive fluorescence emission module 1. As an example, each of the first optical element 301, the second optical element 302, and the third optical element 303 is a lens for condensing the transmitted light L2. As shown in FIG. 6, the first optical element 301, the second optical element 302, and the third optical element 303 are arranged on the fourth main surface 12 side of the phosphor substrate 10. Further, when it is necessary to reduce the size of the projector 500, it is required to reduce the distance between the transmissive fluorescence emission module 1 and the first optical element 301, the second optical element 302, and the third optical element 303.

[0099] The fourth optical element 304 is an optical member for controlling the optical path of the excitation light L1 output from the two light emitting portions 200. As an example, the fourth optical element 304 is a lens for condensing the transmitted light L2. As shown in FIG. 6, the fourth optical element 304 is arranged on the third main surface 11 side of the phosphor substrate 10. Further, as shown in FIG. 6, by condensing the excitation light L1 by the fourth optical element 304, the excitation light L1 also enters the phosphor substrate 10 from an oblique direction (that is, a direction different from perpendicular to the third main surface 11).

[0100] The display element is a substantially planar element that controls the transmitted light L2 and outputs it as an image. In other words, the display element generates light for an image. Specifically, the display element is a transmissive liquid crystal panel. Further, for example, the display element may be a reflective liquid crystal panel or a DLP (Digital Light Processing) having a DMD.

[0101] Subsequently, the behavior of light in FIG. 6 will be described.

[0102] The excitation light L1 emitted by the light emitting unit 200 enters the region A1 of the phosphor substrate 10 in the transmissive fluorescence emitting module 1. A part of the incident excitation light L1 is wavelength-converted by the phosphor material included in the region A1 and transmitted through the phosphor substrate 10 as fluorescence. The other part of the incident excitation light L1 is not wavelength-converted by the phosphor material included in the region A1 and is transmitted through the phosphor substrate 10. The transmitted light L2 transmitted through the phosphor substrate 10 is a composite light including fluorescence which is yellow light and excitation light L1 which is blue light not wavelength-converted, and is white light. Further, the transmitted light L2 is emitted from the phosphor substrate 10. That is, as described above, in the present embodiment, the phosphor substrate 10 is used as a light transmissive phosphor wheel.

[0103] Also, as described above, since the shape of the region A1 is an annular shape, when the phosphor substrate 10 and the like are rotated by the rotating unit 30, the excitation light L1 easily enters the region A1. Therefore, it becomes easier to use the phosphor substrate 10 as a phosphor wheel.

[0104] The transmitted light L2 emitted from the phosphor substrate 10 is condensed and emitted by the first optical element 301, the second optical element 302, and the third optical element 303. Note that the first optical element 301, the second optical element 302, and the third optical element 303 do not necessarily have to condense the transmitted light L2 emitted from the phosphor substrate 10. For example, the first optical element 301, the second optical element 302, and the third optical element 303 may substantially collimate or weakly expand and radiate the emitted transmitted light L2. The emission angle of the transmitted light L2 emitted from the first optical element 301, the second optical element 302, and the third optical element 303 may be an emission angle at which light can be efficiently transmitted in the projector 500 and the lighting device in which the transmissive fluorescence emitting module 1 is used.

[0105] The transmitted light L2 emitted from the first optical element 301, the second optical element 302, and the third optical element 303 travels toward a display element (not shown). The light for the video generated by the display element becomes projection light that is projected onto a screen in an enlarged manner. That is, the transmitted light L2 is light that is used as the projection light output by the projector 500. Note that an optical element or the like (not shown) may be provided between the third optical element 303 and the display element, and the optical path of the transmitted light L2 may be controlled by the optical element.

[0106] In the present embodiment, the transmissive fluorescence emission module 1 includes a light emitting unit 200 that emits excitation light L1 incident on the region A1. The region A1 is a region that does not overlap with the metal member 20 on the phosphor substrate 10. Therefore, light loss such as the excitation light L1 being reflected by the metal member 20 is less likely to occur. For this reason, the excitation light L1 can easily enter the phosphor substrate 10 and generate fluorescence, which is light whose wavelength has been converted.

[0107] Also, in the present embodiment, in a plan view, the shape of the main body 21 is circular. On the first main surface 211 and the second main surface 212 facing each other, the area of the first main surface 211 is larger than the area of the second main surface 212. That is, the shape of the main body 21 is a frustum of a cone. Also, as described above, the excitation light L1 enters the region A1 of the phosphor substrate 10 obliquely from an oblique direction. Therefore, with the main body 21 having the above configuration, it becomes difficult for the excitation light L1 to be blocked by the metal member 20. That is, it is possible to suppress the light loss of the excitation light L1 due to the shielding by the metal member 20. Therefore, the excitation light L1 can easily reach the region A1 of the phosphor substrate 10. From the above, a transmissive fluorescence emission module 1 with higher light utilization efficiency is realized.

[0108] Also, in the present embodiment, the projector 500 includes a transmissive fluorescence emission module 1 with high light utilization efficiency. Therefore, a projector 500 with high light utilization efficiency is realized.

[0109] Since the internal space of the housing 300 is a closed space to suppress contamination such as dust and dirt, heat tends to accumulate. In the present embodiment, the first through hole H1 and the second through hole H2 are provided. Therefore, when the phosphor substrate 10 or the like is rotated by the rotating unit 30, the airflow generated travels from the third main surface 11 side of the phosphor substrate 10 toward the fourth main surface 12 side. For this reason, since the airflow circulates throughout the internal space of the housing 300, the heat generated in the phosphor substrate 10 by the irradiation of the excitation light L1 easily moves from the housing 300 to the outside. Therefore, the heat is more easily dissipated from the phosphor substrate 10.

[0110] Furthermore, the housing 300 will be described in more detail.

[0111] FIG. 7 is a perspective view showing the housing 300 according to the present embodiment. As shown in FIG. 7, the housing 300 has nine components. The nine components are a front member 311, a first left side member 312, a second left side member 313, a first right side member 314, a second right side member 315, a first bottom member 316, a second bottom member 317, a top member 318, and a rear member 319. The housing 300 also has connecting members (such as screws) for connecting the nine components to each other.

[0112] Each of the nine components is formed by, for example, metal plates such as steel plates being subjected to sheet metal processing. That is, each of the nine components is formed by cutting or bending a metal plate. The housing 300 is a case in which such nine components are combined. Since each of the nine components of the housing 300 has a sheet metal structure, it is possible to reduce the weight, for example, compared to a housing having a die-cast structure.

[0113] [Manufacturing Method] Here, the manufacturing method of the phosphor substrate 10 will be briefly described.

[0114] The phosphor material included in the phosphor substrate 10 is (Y 0.999 Ce 0.001 )3Al5O 12It is a material composed of the crystal phase represented by. Also, all the phosphor materials are composed of Ce-activated phosphors. 3+ It is composed of activated phosphors.

[0115] In order to manufacture the phosphor substrate 10, the following three types were used as raw materials as compound powders. Specifically, Y2O3 (purity 3N, Nippon Yttrium Co., Ltd.), Al2O3 (purity 3N, Sumitomo Chemical Co., Ltd.) and CeO2 (purity 3N, Nippon Yttrium Co., Ltd.) were used.

[0116] First, the above raw materials were weighed so as to obtain a compound (Y 0.999 Ce 0.001 )3Al5O 12 . Next, the weighed raw materials and alumina balls (diameter 10 mm) were put into a plastic pot. The amount of the alumina balls was such that it filled about 1 / 3 of the volume of the plastic pot. Then, pure water was put into the plastic pot, and the raw materials and pure water were mixed using a pot rotating device (manufactured by Nitto Kagaku Co., Ltd., BALL MILL ANZ-51S). This mixing was carried out for 12 hours. In this way, a slurry-like mixed raw material was obtained.

[0117] The slurry-like mixed raw material was dried using a dryer. Specifically, a nylon sheet was laid so as to cover the inner wall of a metal vat, and the mixed raw material was poured above the nylon sheet. The metal vat, the nylon sheet, and the mixed raw material were treated in a dryer set at 150°C for 8 hours and dried. Then, the dried mixed raw material was recovered, and the mixed raw material was granulated using a spray dryer device. Note that an acrylic binder was used as an adhesive (binder) during granulation.

[0118] The granulated mixed raw materials were temporarily molded into a cylindrical shape using an electro-hydraulic press (manufactured by Riken Seiki Co., Ltd., EMP-5) and a cylindrical mold. The pressure during molding was set to 5 MPa. Next, using a cold isostatic pressing device, the molded body after temporary molding was fully molded. The pressure during full molding was set to 300 MPa. Note that after full molding, the molded body was subjected to a heat treatment (debinding treatment) for the purpose of removing the adhesive (binder) used during granulation. The temperature of the heat treatment was set to 500 °C. Also, the time of the heat treatment was set to 10 hours.

[0119] The molded body after heat treatment was fired using a tubular atmosphere furnace. The firing temperature was set to 1675 °C. Also, the firing time was set to 4 hours. The firing atmosphere was a mixed gas atmosphere of nitrogen and hydrogen.

[0120] The cylindrical fired product after firing was sliced using a multi-wire saw. The thickness of the sliced cylindrical fired product was set to approximately 700 μm.

[0121] Using a polishing device, the fired product after slicing was polished to adjust the thickness of the fired product. By performing this adjustment, the fired product becomes the phosphor substrate 10.

[0122] [Temperature of the phosphor substrate] Here, using the transmissive fluorescent emission module according to the study example, the temperature of the phosphor substrate 10 in the transmissive fluorescent emission module 1 according to the present embodiment will be described. First, the transmissive fluorescent emission module according to the study example will be described.

[0123] FIG. 8 is a plan view of the phosphor substrate 10, the metal member 20x, and the rotating part 30 included in the transmissive fluorescent emission module according to the study example. FIG. 9 is a plan view of the phosphor substrate 10, the metal member 20, and the rotating part 30 according to the present embodiment. FIG. 10 is a perspective view of the phosphor substrate 10, the metal member 20x, and the rotating part 30 included in the transmissive fluorescent emission module according to the study example. FIG. 11 is a perspective view of the phosphor substrate 10, the metal member 20, and the rotating part 30 according to the present embodiment.

[0124] As shown in FIGS. 8 and 10, the transmissive fluorescence emission module according to the study example is a module including a phosphor substrate 10, a metal member 20x, and a rotating portion 30. Further, the transmissive fluorescence emission module according to the study example includes two light emission portions 200 (not shown). In the transmissive fluorescence emission module according to the study example, only the shape of the metal member 20x is different from that of the transmissive fluorescence emission module 1 according to the present embodiment.

[0125] Here, the metal member 20x will be described.

[0126] The metal member 20x has the same configuration as the metal member 20 except for the shape. The shape of the metal member 20x is a flat member provided so as to be laminated with the phosphor substrate 10. More specifically, as shown in FIGS. 8 and 10, the shape of the metal member 20x is a cylindrical shape.

[0127] Further, as shown in FIGS. 8, 9, 10, and 11, the outer diameter of the metal member 20 (here, the outer diameter of the main body portion 21) is larger than the outer diameter of the metal member 20x. The outer diameter of the metal member 20x means the diameter of the metal member 20x.

[0128] The outer diameter (diameter) of the metal member 20x is 28 mm. Further, in FIG. 8, the radius D31x of the metal member 20x is shown, and the radius D31x of the metal member 20x is 14 mm.

[0129] Similarly, in FIG. 9, the radius D31 of the main body portion 21 is shown. As described above, the radius D31 of the main body portion 21 is 17 mm.

[0130] Further, when viewed in plan, the phosphor substrate 10 according to the study example has an annular region A1x that does not overlap with the metal member 20x. In each of FIGS. 8 and 9, the region A1x and the region A1 correspond to the region between the two circles indicated by the dashed-dotted line.

[0131] Further, in the present embodiment, when the phosphor substrate 10 is viewed in plan view, the main body portion 21 and the region A1 are adjacent to each other. Here, the circle inside the annular region A1 is in contact with the main body portion 21 (more specifically, the first main surface 211).

[0132] Similarly, in the study example, when the phosphor substrate 10 is viewed in plan view, the metal member 20x and the region A1 are adjacent to each other. The circle inside the annular region A1x is in contact with the metal member 20x.

[0133] Furthermore, the temperature of the phosphor substrate 10 will be described. Here, the temperature of the phosphor substrate 10 when the phosphor substrate 10, the metal member 20x, and the metal member 20 are rotated by the rotating portion 30 and the excitation light L1 is irradiated onto the region A1x and the region A1 will be described. More specifically, the excitation light L1 is irradiated onto the irradiation center position among the region A1x and the region A1. Also, FIGS. 8 and 9 show the irradiation center position distance D32, which is the distance between the center point C1 and the irradiation center position of the excitation light L1, and the irradiation center position distance D32 is 18 mm.

[0134] FIG. 12 is a diagram showing the temperature profiles of the phosphor substrate 10 according to the study example and the present embodiment. More specifically, the temperature profile of the phosphor substrate 10 according to the study example shows the temperature measured along the measurement line M1 shown in FIG. 8. Similarly, the temperature profile of the phosphor substrate 10 according to the present embodiment shows the temperature measured along the measurement line M2 shown in FIG. 9. Also, both the measurement line M1 and the measurement line M2 are virtual lines of straight lines parallel to the x-axis. Further, in FIG. 12, the position at a distance of 0 mm corresponds to the center point C1 in FIGS. 8 and 9.

[0135] As shown in FIG. 12, in the study example, the temperature at a distance of 18 mm, which is the irradiation center position of the excitation light L1 (that is, the position at a distance of the irradiation center position distance D32 from the distance 0 mm), is the highest temperature compared to other positions. Also, in the present embodiment, a similar tendency is shown.

[0136] However, when comparing the study example and the present embodiment, at the irradiation center position of the excitation light L1, the temperature in the present embodiment is lower than the temperature in the study example.

[0137] As described above, the radius D31 of the main body portion 21 is larger than the radius D31x of the metal member 20x. That is, compared with the metal member 20x, the main body portion 21 is provided at a position closer to the irradiation center position of the excitation light L1. Therefore, even when heat is generated in the phosphor substrate 10 due to the irradiation of the excitation light L1, the heat easily moves from the phosphor substrate 10 to the main body portion 21 (that is, the metal member 20). Thus, in the present embodiment, the heat dissipation property of the phosphor substrate 10 can be further enhanced.

[0138] Summarizing the above, in the present embodiment, when the phosphor substrate 10 is viewed in plan, the main body portion 21 and the region A1 are adjacent to each other. Further, it is preferable that the radius D31 of the main body portion 21 is smaller than the irradiation center position distance D32, and the main body portion 21 is provided at a position closer to the irradiation center position of the excitation light L1. For example, the difference between the radius D31 of the main body portion 21 and the irradiation center position distance D32 may be, for example, 3 mm or less, more preferably 2 mm or less, and even more preferably 1 mm or less.

[0139] Thereby, since the heat generated by the irradiation of the excitation light L1 easily moves from the phosphor substrate 10 to the main body portion 21 (that is, the metal member 20), the heat dissipation property of the phosphor substrate 10 can be further enhanced.

[0140] (Modification Example 1 of Embodiment 1) Next, the transmissive fluorescent emission module 1a according to Modification Example 1 of Embodiment 1 will be described with reference to FIGS. 13A and 13B. FIG. 13A is a perspective view of the transmissive fluorescent emission module 1a according to the present modification example. FIG. 13B is an exploded perspective view of the transmissive fluorescent emission module 1a according to the present modification example.

[0141] The transmissive fluorescence emission module 1a according to this modification example is a module including a phosphor substrate 10, a metal member 20a, a rotating portion 30, and two light emitting portions 200. For simplicity, in FIGS. 13A and 13B, only one light emitting portion 200 is shown.

[0142] That is, the transmissive fluorescence emission module 1a according to this modification example is different from the transmissive fluorescence emission module 1 according to Embodiment 1 in that it includes the metal member 20a instead of the metal member 20.

[0143] Here, the metal member 20a will be described. The metal member 20a has the same configuration as the metal member 20 except for the shape. The metal member 20a has a main body portion 21a and a plurality of heat dissipation fins 22a.

[0144] The main body portion 21a is a flat plate-shaped member provided so as to be laminated with the phosphor substrate 10.

[0145] In addition, in a plan view, the shape of the main body portion 21a is circular. Furthermore, since a second through hole H2 is provided in the main body portion 21a, the shape of the main body portion 21a is an annular shape.

[0146] The main body portion 21 also has a first side surface portion 213a. As shown in FIG. 13A, the first side surface portion 213a stands upright in a direction perpendicular to the phosphor substrate 10, that is, extends in a direction parallel to the z-axis.

[0147] Furthermore, the plurality of heat dissipation fins 22a included in the metal member 20a will be described. The plurality of heat dissipation fins 22 are protrusions that stand upright in a direction opposite to the direction from the main body portion 21 toward the phosphor substrate 10.

[0148] As shown in FIGS. 13A and 13B, here, 12 heat dissipation fins 22a are provided. When viewed in a plan view, the 12 heat dissipation fins 22a are provided so as to extend radially.

[0149] Further, each of the plurality of heat radiation fins 22a has a second side surface portion 211a at a position farthest from the axis B1. The second side surface portion 221a of each of the plurality of heat radiation fins 22a extends in a direction parallel to the z-axis, similar to the first side surface portion 213a. Further, the second side surface portion 221a and the first side surface portion 213a of the main body portion 21a are flush and connected. Also, the second side surface portion 221a and the first side surface portion 213a are parallel to each other at the connection location.

[0150] Further, when viewed in plan, the phosphor substrate 10 according to Modification 1 has an annular region A2 that does not overlap with the metal member 20a. In FIG. 13B, the region A2 corresponds to the region between the two circles indicated by the dashed-dotted line.

[0151] Thus, the transmissive fluorescence emission module 1a includes the phosphor substrate 10, the metal member 20a, the rotating portion 30, and the two light emitting portions 200. Thereby, a transmissive fluorescence emission module 1a capable of enhancing the light utilization efficiency is realized, similar to the transmissive fluorescence emission module 1 according to Embodiment 1.

[0152] (Modification 2 of Embodiment 1) Next, the transmissive fluorescence emission module according to Modification 2 of Embodiment 1 will be described with reference to FIG. 14.

[0153] FIG. 14 is a perspective view of the transmissive fluorescence emission module according to Modification 2 of the present embodiment. In FIG. 14, the light emitting portion 200 is omitted.

[0154] The transmissive fluorescence emission module according to this modification is different from the transmissive fluorescence emission module 1a in that it includes a cover 40 in addition to the components included in the transmissive fluorescence emission module 1a according to Modification 1.

[0155] The cover 40 is a resin or metal member having a cover main body portion 41 and a flow path portion 42. Also, the cover 40 is not rotated by the rotating portion 30.

[0156] The cover main body 41 is a member that covers the phosphor substrate 10 and the metal member 20a. Also, in this modified example, a part of the rotating portion 30 is exposed from a circular hole provided on the negative z-axis side of the cover main body 41. That is, the cover main body 41 covers the other part of the rotating portion 30, the phosphor substrate 10, and the metal member 20a. By providing such a cover main body 41, it is possible to control the airflow generated when the phosphor substrate 10 and the metal member 20a rotate due to the rotating portion 30.

[0157] The flow path portion 42 is a member connected to the cover main body 41. In a plan view, the flow path portion 42 is provided at a position overlapping the region A2 where the excitation light L1 is incident. Further, the controlled airflow described above flows through the flow path portion 42.

[0158] Since the cover 40 has the above configuration, the airflow generated when the phosphor substrate 10 or the like rotates due to the rotating portion 30 heads toward the region A2. More specifically, the airflow passes through the negative z-axis side of the region A2. In FIG. 14, an example of the airflow is shown by a dashed-dotted arrow. The generated airflow cools the phosphor substrate 10. That is, the temperature quenching phenomenon is less likely to occur, and the decrease in fluorescence is suppressed. Therefore, the light utilization efficiency of the transmissive fluorescence emission module according to this modified example can be further improved.

[0159] (Modified Example 3 of Embodiment 1) Next, the transmissive fluorescence emission module according to Modified Example 3 of Embodiment 1 will be described with reference to FIG. 15.

[0160] FIG. 15 is a bottom view of the phosphor substrate 10 and the metal member 20b according to Modified Example 3 of the present embodiment. In FIG. 15, the rotating portion 30 and the light emitting portion 200 are omitted. Also, in FIG. 15, the region A3 included in the phosphor substrate 10 according to Modified Example 3 corresponds to the region between two circles indicated by a dashed-dotted line.

[0161] In this modified example, the shapes of the plurality of radiation fins 22b are different from the shapes of the plurality of radiation fins 22 shown in the above-described embodiment. The plurality of radiation fins 22b have a curved arc shape in a bottom view. In other words, the plurality of radiation fins 22b have a spiral shape. Since the plurality of radiation fins 22b have such a shape, when the phosphor substrate 10 or the like is rotated by the rotating part 30, a strong air flow with a higher flow velocity is generated.

[0162] Note that the transmissive fluorescence emission module 1 according to this embodiment only needs to include a phosphor substrate 10, a metal member 20, and a rotating part 30. Further, when the phosphor substrate 10 is viewed in a plan view, the phosphor substrate 10 only needs to have an annular region A1 that does not overlap with the metal member 20.

[0163] By providing the metal member 20, heat is easily radiated from the phosphor substrate 10. As a result, the temperature quenching phenomenon hardly occurs, and thus the decrease in fluorescence is suppressed.

[0164] Moreover, the transmissive fluorescence emission module 1 does not include components for supporting the phosphor substrate 10 or the like. Therefore, there is no optical loss of the excitation light L1 as described above, and thus the excitation light L1 incident on the phosphor substrate 10 increases. As a result, the fluorescence generated by the phosphor material in the phosphor substrate 10 increases.

[0165] In addition, by providing the rotating part 30, the phosphor substrate 10 or the like rotates about the axis B1, and thus an air flow is generated. The generated air flow cools the phosphor substrate 10. As a result, even when the excitation light L1 is irradiated, the temperature rise of the phosphor substrate 10 can be suppressed, so that the temperature quenching phenomenon hardly occurs and the decrease in fluorescence is suppressed.

[0166] To summarize the above, in the transmissive fluorescence emission module 1, the temperature quenching phenomenon hardly occurs and there is no optical loss of the excitation light L1, so that the light utilization efficiency can be improved.

[0167] (Embodiment 2) In Embodiment 1, for example, as shown in FIGS. 1A and 1B, a transmissive fluorescence emission module 1 is described in which a phosphor substrate 10 provided with a first through hole H1, a metal member 20 provided with a second through hole H2, and a rotating portion 30 are connected and assembled. In this transmissive fluorescence emission module 1, the first through hole H1 and the second through hole H2 are assembled so as to overlap, and the airflow generated when the phosphor substrate 10 and the like are rotated by the rotating portion 30 is directed from the third main surface 11 side of the phosphor substrate 10 toward the fourth main surface 12 side. That is, the heat generated in the phosphor substrate 10 by the irradiation of the excitation light L1 is cooled by passing the airflow generated when the phosphor substrate 10 and the like are rotated by the rotating portion 30 through the first through hole H1 and the second through hole H2 (allowing air to flow).

[0168] However, depending on the type of motor used in the rotating portion 30, the second through hole H2 of the metal member 20 may fit with the motor shaft of the rotating portion 30, and a sufficient gap for allowing air to flow may not be ensured in the second through hole H2, and the cooling effect may not be exhibited.

[0169] Furthermore, it has been found that the stress due to the heat generated in the phosphor substrate 10 by the irradiation of the excitation light L1 is concentrated at several locations on the phosphor substrate 10. Therefore, when the through hole provided at the center of the metal member cannot exhibit a cooling effect, there is a risk of breakage due to stress concentration on the phosphor substrate 10.

[0170] Therefore, in Embodiment 2, a transmissive fluorescence emission module, that is, a phosphor wheel 1B, which can reduce the risk of breakage of the phosphor substrate even when the through hole provided at the center of the metal member cannot exhibit a cooling effect, will be described. Hereinafter, the description will focus on the differences from the metal member 20 described in Embodiment 1.

[0171] [Phosphor Wheel 1B] FIG. 16 is an exploded perspective view of the phosphor wheel 1B according to Embodiment 2. FIG. 17A is a perspective view of the phosphor wheel 1B according to Embodiment 2 as viewed from the positive z-axis side. FIG. 17B is a perspective view of the phosphor wheel 1B according to Embodiment 2 as viewed from the negative z-axis side.

[0172] The phosphor wheel 1B according to Embodiment 2 is a transmissive phosphor wheel, and like Embodiment 1, it is used in a light-emitting device typified by a projector and a lighting device.

[0173] As shown in FIGS. 16, 17A, and 17B, the phosphor wheel 1B includes a phosphor substrate 10B made of a phosphor material, a metal member 20B including a first heat dissipation member 23B and a second heat dissipation member 24B, and a rotating portion 30B. Note that the same reference numerals are given to the same elements as those in FIGS. 1A and 1B, etc., and detailed descriptions thereof are omitted.

[0174] [Phosphor Substrate 10B] The phosphor substrate 10B is an annular substrate made of a phosphor material. The phosphor substrate 10B has an annular region that does not overlap with the metal member 20B when viewed in plan. As shown in FIG. 16, the phosphor substrate 10B has an annular region A11 having an inner diameter and an outer diameter with substantially equal distances from the center point C1, and a first through hole 101B that is a hole penetrating the phosphor substrate 10B in the thickness direction (z-axis direction) of the phosphor substrate 10B.

[0175] The phosphor substrate 10B has a larger inner diameter than the phosphor substrate 10 shown in FIGS. 1A and 1B. As shown in FIGS. 17A and 17B, the phosphor substrate 10B is held sandwiched between a first heat dissipation member 23B and a second heat dissipation member 24B that constitute the metal member 20B. The phosphor substrate 10B is held by having a region with a width of several millimeters on the inner peripheral side of the annular region A11 sandwiched between the first heat dissipation member 23B and the second heat dissipation member 24B. Further, the outer diameter of the phosphor substrate 10B is larger than the outer diameters of the first heat dissipation member 23B and the second heat dissipation member 24B, that is, the outer diameter of the metal member 20B, and the inner diameter of the phosphor substrate 10B is slightly smaller than the outer diameters of the first heat dissipation member 23B and the second heat dissipation member 24B. For this reason, the region of the phosphor substrate 10B excluding the region of several millimeters on the inner peripheral side of the annular region A11 is an annular region that does not overlap with the metal member 20B when viewed in plan.

[0176] Here, the outer diameter of the phosphor substrate 10B is, for example, 40 mm or more and 50 mm or less, but is not limited thereto and may be 35 mm or more and 70 mm or less, or may be 30 mm or more and 90 mm or less.

[0177] Also, the inner diameter of the phosphor substrate 10B is, for example, 30 mm or more and 40 mm or less, but is not limited thereto and may be 25 mm or more and 60 mm or less, or may be 20 mm or more and 80 mm or less. Further, the thickness of the phosphor substrate 10B is, for example, about 0.2 mm, but is not limited thereto and may be 0.1 mm or more and 0.3 mm or less, or may be 0.08 mm or more and 0.5 mm or less. Note that the outer diameter R, inner diameter, and thickness of the phosphor substrate 10B may be appropriately determined so as to fit within the housing of a product such as a projector to which the phosphor wheel 1B is applied.

[0178] Other configurations such as the material of the phosphor substrate 10B are the same as those in the first embodiment, and thus the description thereof is omitted.

[0179] [Metal member 20B] The metal member 20B holds the phosphor substrate 10B. In the present embodiment, as shown in FIG. 16 for example, the metal member 20B includes a first heat radiating member 23B disposed on the main surface side (the side of the fourth main surface 12) of the phosphor substrate 10B and a second heat radiating member 24B disposed on the side opposite to the main surface (the fourth main surface 12) of the phosphor substrate 10B (the side of the third main surface 11).

[0180] The metal member 20B shown in FIGS. 16, 17A, and 17B is mainly different in that it is composed of two heat radiating members, namely the first heat radiating member 23B and the second heat radiating member 24B, while the metal member 20 shown in FIGS. 1A and 1B is composed of one heat radiating member.

[0181] As shown in FIGS. 17A and 17B, the first heat radiating member 23B and the second heat radiating member 24B sandwich and hold the phosphor substrate 10B.

[0182] Note that a plurality of heat radiating fins are provided on one of the first heat radiating member 23B and the second heat radiating member 24B. Also, in the examples shown in FIGS. 16, 17A, and 17B, the plurality of heat radiating fins 202 are provided on the first heat radiating member 23B.

[0183] Hereinafter, the first heat radiating member 23B and the second heat radiating member 24B according to the present embodiment will be described.

[0184] FIG. 18 is a perspective view of the first heat radiating member 23B according to Embodiment 2 as viewed from the negative z-axis side. FIG. 19 is a perspective view of the second heat radiating member 24B according to Embodiment 2 as viewed from the negative z-axis side. FIG. 20A is a perspective view of the first heat radiating member 23B and the second heat radiating member 24B holding the phosphor substrate 10B as viewed from the negative z-axis side.

[0185] <The first heat radiating member 23B> As described above, the first heat radiating member 23B is arranged on the main surface side (the side of the fourth main surface 12) of the phosphor substrate 10B as shown in FIG. 16, and is a disk-shaped plate material that rotates about the center point C1 together with the second heat radiating member 24B and the phosphor substrate 10B. In the present embodiment, the first heat radiating member 23B holds the phosphor substrate 10B by sandwiching and holding a region about 5 mm from the inner diameter of the phosphor substrate 10B together with the second heat radiating member 24B.

[0186] As shown in FIG. 18, the first heat radiating member 23B includes a plurality of regions 201, a plurality of heat radiating fins 202, and a plurality of screw holes 203.

[0187] Each of the plurality of regions 201 is a partial region in the inner ring region excluding the outer ring region 204 and the central portion 205 of the first heat radiating member 23B, and becomes a through hole after the heat radiating fins 202 are formed. As shown in FIG. 18, each of the plurality of regions 201 is a through hole penetrating the first heat radiating member 23B. The plurality of regions 201 function as ventilation holes through which the wind generated by the plurality of heat radiating fins 202 passes. The outer diameter of the plurality of regions 201 is, for example, about 26 mm, but is not limited thereto, and may be 15 mm or more and 44 mm or less. The maximum value may be appropriately determined in consideration of the degree of penetration of the heat radiating fins 202 cut up into the second heat radiating member 24B. The minimum value may be appropriately determined in consideration of the dimensions of the disk portion 31 of the motor and the function of the heat radiating fins 202 to cause convection.

[0188] Each of the plurality of heat radiating fins 202 is provided by cutting up a region 201, which is a partial region of the first heat radiating member 23B, toward the negative z-axis side. In other words, the plurality of heat radiating fins 202 are erected on the first heat radiating member 23B when the plurality of regions 201 are cut up toward the negative z-axis side. When the plurality of heat radiating fins 202 sandwich and hold the phosphor substrate 10B together with the second heat radiating member 24B as shown in FIG. 20A, they are erected so as to protrude from the phosphor substrate 10B (and the outer ring region 210 of the second heat radiating member 24B) toward the third main surface 11 side (negative z-axis side).

[0189] The screw hole 203 is a hole used to fix the first heat dissipation member 23B and the second heat dissipation member 24B by screwing. In the present embodiment, three screw holes 203 are provided in a region connecting the central portion 205 and the outer ring region 204 of the first heat dissipation member 23B. Thereby, the first heat dissipation member 23B and the second heat dissipation member 24B can hold (clamp) the phosphor substrate 10B therebetween without using an adhesive member.

[0190] Here, the outer diameter of the first heat dissipation member 23B is approximately the same as the outer diameter of the second heat dissipation member 24B, but is smaller than the outer diameter of the phosphor substrate 10B and larger than the inner diameter of the phosphor substrate 10B. The outer diameter of the first heat dissipation member 23B is, for example, 34 mm, but is not limited thereto, and may be 30 mm or more and 44 mm or less. The maximum value may be, for example, a value equal to or less than the value at which a light source of laser light having a diameter of around 1 mm is effectively irradiated on the annular region A11 of the phosphor substrate 10B. The minimum value may be appropriately determined in consideration of the joining position with the motor used for the rotating portion 30B and the minimum size that can effectively ensure the strength of the first heat dissipation member 23B. Further, the thickness of the first heat dissipation member 23B is, for example, about 0.3 mm, but is not limited thereto, and may be 0.5 mm or more and 5 mm or less. The upper limit thereof may be appropriately determined so that the raised dimension of the heat dissipation fins does not exceed the range in which the joining of the disk portion 31 of the motor and the second heat dissipation member is possible.

[0191] Note that the material of the first heat dissipation member 23B is, for example, Al or the like, but the description is omitted because it is the same as the material of the metal member 20 according to the first embodiment.

[0192] <The second heat dissipation member 24B> As described above, the second heat radiating member 24B is arranged on the side opposite to the main surface (the fourth main surface 12) of the phosphor substrate 10B (the side of the third main surface 11) as shown in FIG. 16, and is a disk-shaped member that rotates about the center point C1 together with the first heat radiating member 23B and the phosphor substrate 10B. In the present embodiment, the second heat radiating member 24B holds (clamps) the phosphor substrate 10B by sandwiching a region about 5 mm from the inner diameter of the phosphor substrate 10B together with the first heat radiating member 23B. Note that the material of the second heat radiating member 24B is, for example, Al or the like, but the description is omitted because it is the same as the material of the metal member 20 according to the first embodiment.

[0193] As shown in FIG. 19, the second heat radiating member 24B includes a plurality of screw holes 203A, a plurality of rod-shaped members 206, an opening region 207, a second through hole 208, and a circular member 209.

[0194] The screw holes 203A are holes used to fix the first heat radiating member 23B and the second heat radiating member 24B by screwing. In the present embodiment, the screw holes 203A are provided in three rod-shaped members 206 that connect the circular member 209 and the outer ring region 210 of the second heat radiating member 24B. Thereby, the first heat radiating member 23B and the second heat radiating member 24B can hold (clamp) the phosphor substrate 10B without using an adhesive member.

[0195] Note that the screw holes 203A may be used to fix the disk portion 31, the first heat radiating member 23B, and the second heat radiating member 24B by screwing. Thereby, since the first heat radiating member 23B, the phosphor substrate 10B, the second heat radiating member 24B, and the rotating portion 30B can be connected, the first heat radiating member 23B, the phosphor substrate 10B, and the second heat radiating member 24B can be easily rotated about the center point C1.

[0196] The rod-shaped member 206 is a member provided for screwing the first heat-radiating member 23B and the second heat-radiating member 24B. The rod-shaped member 206 connects the circular member 209 and the outer ring region 210 of the second heat-radiating member 24B, and fixes the first heat-radiating member 23B and the second heat-radiating member 24B by screwing. Thereby, the first heat-radiating member 23B, the phosphor substrate 10B, and the second heat-radiating member 24B can be fixed with high rigidity, so that even when they are rotated, they can be suppressed from bending and can be easily rotated.

[0197] The opening region 207 is provided in the inner ring region excluding the outer ring region 210 of the second heat-radiating member 24B. More specifically, as shown in FIG. 19, the opening region 207 is provided in the inner ring region of the second heat-radiating member 24, excluding the rod-shaped member 206, the second through-hole 208, and the circular member 209. As shown in FIG. 20A, the opening region 207 is provided so that when the first heat-radiating member 23B and the second heat-radiating member 24B hold the phosphor substrate 10B, a plurality of heat-radiating fins 202 can protrude more than the second heat-radiating member 24B.

[0198] As shown in FIG. 19 and the like, the second through-hole 208 is a hole that penetrates the second heat-radiating member 24B in the thickness direction (z-axis direction) of the second heat-radiating member 24B. The second through-hole 208 is provided in the circular member 209. As shown in FIG. 16, the axis of the motor shaft of the rotating portion 30B passes through and is fitted into the second through-hole 208.

[0199] The circular member 209 is a circular member located at the center of the second heat-radiating member 24B and connected to the rod-shaped member 206. The second through-hole 208 is provided in the central region thereof. Thereby, the second heat-radiating member 24B can be lightened, and since the circular member 209 can be fitted with the motor shaft of the rotating portion 30, the second heat-radiating member 24B can be easily rotated. In the present embodiment, an example of the outer diameter of the circular member 209 is about 13 mm, and an example of the inner diameter thereof is about 11 mm, but it is not limited thereto.

[0200] Here, the outer diameter of the second heat dissipation member 24B is approximately the same as that of the first heat dissipation member 23B, but is smaller than the outer diameter of the phosphor substrate 10B and larger than the inner diameter of the phosphor substrate 10B. The outer diameter of the second heat dissipation member 24B is, for example, 34 mm, but is not limited thereto, and may be 30 mm or more and 48 mm or less. The maximum value thereof may be a value equal to or less than the value at which a light source of a laser beam having a diameter of around 1 mm, for example, is effectively irradiated to the annular region A11 of the phosphor substrate 10B. The minimum value may be appropriately determined in consideration of the joining position with the motor used for the rotating portion 30B and the minimum size that can effectively ensure the strength of the second heat dissipation member 24B. The inner diameter of the second heat dissipation member 24B (the inner diameter of the outer ring region 210) is, for example, about 28 mm, but is not limited thereto, and may be 30 mm or more and 48 mm or less. The maximum value thereof may be a value equal to or less than the value at which a light source of a laser beam having a diameter of around 1 mm, for example, is effectively irradiated to the annular region A11 of the phosphor substrate 10B. The minimum value may be appropriately determined in consideration of the joining position with the motor used for the rotating portion 30B and the minimum size that can effectively ensure the strength of the second heat dissipation member 24B.

[0201] FIG. 20B is a partially enlarged side view of the metal member 20B in FIG. 20A. FIG. 20C is a partially enlarged side view of the metal member 20 shown in FIG. 1B as a comparative example. FIG. 20B shows a perspective view in which the first heat dissipation member 23B and the second heat dissipation member 24B in the region J of FIG. 20A are enlarged. FIG. 20C shows, as a comparative example, a perspective view in which the region K of the metal member 20 shown in FIG. 1B, which is a region corresponding to the region J of the metal member 20B, is enlarged. Note that the same reference numerals are given to the same elements as in FIG. 1B and the like, and detailed descriptions thereof are omitted.

[0202] The thickness of the outer ring region 210 of the second heat radiating member 24B is provided to be lower than the height of the plurality of heat radiating fins 202 provided on the first heat radiating member 23B, as shown in Fig. 20B. More specifically, the thickness of the outer ring region 210 is provided to be lower than the height of the plurality of heat radiating fins 202 raised in the first heat radiating member 23B. As can be seen by comparing regions J1 and J2 in Fig. 20B with regions K1 and K2 in Fig. 20C, the thickness of the metal member 20B (the thickness of the outer ring region 210) according to the present embodiment is provided to be thinner than the thickness of the metal member 20 (the thickness of the heat radiating fins 22). That is, in the present embodiment, the thickness of the outer ring region 210 of the second heat radiating member 24B, which is the thickness in the vicinity of the portion where the phosphor substrate 10B is sandwiched, is decreased.

[0203] Here, the thickness of the outer ring region 210 is, for example, about 1 mm, and the thickness of the inner ring portion is about 1.7 mm, but it is not limited thereto, and the total thickness thereof may be 2.5 mm or more and 10 mm or less. The upper limit of the thickness may be appropriately determined so that the rotational load applied to the motor used for the rotating portion 30B does not exceed the tolerance of the motor.

[0204] Note that since the material of the first heat radiating member 23B and the like are the same as those of the metal member 20 according to Embodiment 1, the description thereof is omitted.

[0205] [Rotating portion 30B] The rotating portion 30B has a disk portion 31 and a rotating shaft having a shaft B1 as an axis. The rotating portion 30B rotates the phosphor substrate 10B and the metal member 20B (the first heat radiating member 23B and the second heat radiating member 24B) about a shaft B1 extending in the thickness direction of the phosphor substrate 10B (central axis). The rotating portion 30B is provided at a position overlapping the phosphor substrate 10B in plan view and is joined or screwed to the second heat radiating member 24B. The rotating portion 30B is, for example, an outer rotor type motor, but is not particularly limited. The rotating portion 30B rotationally drives the phosphor substrate 10B and the metal member 20B by being controlled by an electronic circuit (not shown).

[0206] In the present embodiment, the axis of the motor shaft of the rotating portion 30B fits into the second through hole 208 of the second heat radiating member 24B.

[0207] [Effects, etc.] The verification results obtained by simulating the thermal stress on the phosphor substrate 10B according to the present embodiment configured as described above will be described.

[0208] FIG. 21 is a diagram showing the verification results of the thermal stress on the phosphor substrate 10B according to Embodiment 2. In FIG. 21(a), the simulation results of the thermal stress on the phosphor substrate 10B according to the present embodiment are shown as verification results. In the lower part of FIG. 21(a), an enlarged view of the region P of the simulation results of the thermal stress on the phosphor substrate 10B shown in the upper part of FIG. 21(a) is shown, and it is shown that the thermal stress at the location indicated by the circle where the thermal stress is concentrated is 222 MPa. In FIG. 21(b), as a comparative example, the simulation results of the thermal stress on the phosphor substrate 10 according to Embodiment 1 are also shown. In the lower part of FIG. 21(b), an enlarged view of the region Q of the simulation results of the thermal stress on the phosphor substrate 10 shown in the upper part of FIG. 21(b) is shown, and it is shown that the thermal stress at the location indicated by the circle where the thermal stress is concentrated is 241 MPa.

[0209] It can be seen from FIG. 21 that the thermal stress at the location where the thermal stress is concentrated in the phosphor substrate 10B according to Embodiment 2 is reduced by about 8% compared to the thermal stress at the location where the thermal stress is concentrated in the phosphor substrate 10 according to the comparative example.

[0210] Also, in the present embodiment, the phosphor substrate 10B is held sandwiched between the first heat dissipation member 23B and the second heat dissipation member 24B, and is not joined to the first heat dissipation member 23B and the second heat dissipation member 24B by an adhesive member. Since the phosphor substrate 10B is not joined to the first heat dissipation member 23B and the second heat dissipation member 24B by an adhesive member, it is considered that internal stress such as thermal expansion due to heat in the first heat dissipation member 23B and the second heat dissipation member 24B is less likely to be applied to the phosphor substrate 10B. Further, as described with reference to FIG. 20B, the thickness of the second heat dissipation member 24B at the portion in contact with the phosphor substrate 10B is thinner than that of the phosphor substrate 10 in the comparative example. Therefore, from Stoney's formula, it is considered that the stress applied to the phosphor substrate 10B can be relaxed by reducing the thickness of the second heat dissipation member 24B at the portion in contact with the phosphor substrate 10B. Thus, it can be seen that the phosphor wheel 1B according to the present embodiment can suppress the risk of breakage due to stress concentration on the phosphor substrate 10B.

[0211] As described above, the phosphor wheel 1B according to the present embodiment is a transmissive phosphor wheel, and includes a phosphor substrate 10B which is an annular substrate made of a phosphor material, and a metal member 20B that holds the phosphor substrate 10B. Further, the phosphor wheel 1B includes a rotating portion 30B that rotates the phosphor substrate 10B and the metal member 20B about an axis extending in the thickness direction of the phosphor substrate 10B. The phosphor substrate 10B has an annular region A11 that does not overlap with the metal member 20B when the phosphor substrate 10B is viewed in plan. The metal member 20B includes a first heat dissipation member 23B disposed on the main surface side of the phosphor substrate 10B, and a second heat dissipation member 24B disposed on the opposite side of the main surface of the phosphor substrate 10B. The first heat dissipation member 23B and the second heat dissipation member 24B hold the phosphor substrate 10B by sandwiching it. A plurality of heat dissipation fins are provided on one of the first heat dissipation member 23B and the second heat dissipation member 24B.

[0212] As described above, in this embodiment, the metal member 20B is composed of the first heat dissipation member 23B and the second heat dissipation member 24B, and by sandwiching the phosphor substrate 10B, it is possible to alleviate the concentration of stress due to the heat generated in the phosphor substrate 10 by the irradiation of the excitation light L1 on the phosphor substrate 10B. Therefore, the risk of damage to the phosphor substrate 10B due to thermal stress can be suppressed.

[0213] Here, in the phosphor wheel 1B according to this embodiment, the plurality of heat dissipation fins 202 may be provided on the first heat dissipation member 23B. In this case, the thickness of the outer ring region 210 of the second heat dissipation member 24B is preferably provided to be lower than the height of the plurality of heat dissipation fins 202 provided on the first heat dissipation member 23B. Thereby, the thickness of the outer ring region 210 of the second heat dissipation member 24B, which is the thickness in the vicinity of the portion where the phosphor substrate 10B is sandwiched, can be reduced. Therefore, as can be seen from Stoney's formula, by reducing the thickness of the second heat dissipation member 24B in the portion in contact with the phosphor substrate 10B, the stress applied to the phosphor substrate 10B can be alleviated, and the risk of damage due to stress concentration on the phosphor substrate 10B can be suppressed.

[0214] Furthermore, the plurality of heat dissipation fins 202 may be provided by raising a plurality of regions 201 in a region excluding the outer ring region 204 and the central portion 205 of the first heat dissipation member 23B. In this case, the thickness of the outer ring region 210 of the second heat dissipation member 24B is provided to be lower than the height of the plurality of heat dissipation fins 202 raised in the first heat dissipation member 23B. Also, in the inner ring region of the second heat dissipation member 24B, an opening region 207 is provided through which the plurality of heat dissipation fins 202 can protrude from the second heat dissipation member 24B when the first heat dissipation member 23B and the second heat dissipation member 24B hold the phosphor substrate 10B. Thereby, since the thickness of the outer ring region of the first heat dissipation member 23B and the outer ring region 210 of the second heat dissipation member 24B can be reduced as the thickness in the vicinity of the portion where the phosphor substrate 10B is sandwiched, the stress applied to the phosphor substrate 10B can be relaxed. Furthermore, in the metal member 20B, a plurality of heat dissipation fins 202 are provided at positions corresponding to the opening region 207, and the plurality of regions 201 where the plurality of heat dissipation fins 202 are raised function as through holes. Thereby, the airflow generated when the phosphor substrate 10B or the like is rotated by the rotating portion 30B can be directed from the positive side of the z-axis (the side of the third main surface 11) of the phosphor substrate 10B toward the negative side of the z-axis (the side of the fourth main surface 12). The heat generated in the phosphor substrate 10B by the irradiation of the excitation light L1 is transmitted to the metal member 20B in contact with the phosphor substrate 10B, that is, the first heat dissipation member 23B and the second heat dissipation member 24B, and is cooled by the airflow passing through the regions 201 and the opening region 207 and the heat dissipation fins 202. That is, since the heat from the phosphor substrate 10B is more easily dissipated, the temperature rise of the phosphor substrate 10B due to the irradiation of the excitation light L1 can be suppressed. As a result, since the temperature quenching phenomenon hardly occurs, the decrease in fluorescence is suppressed.

[0215] (Modification example) In the above-described Embodiment 2, an example in the case where a plurality of heat radiation fins are provided on the first heat radiation member has been described, but the present invention is not limited thereto. The plurality of heat radiation fins may be provided on the second heat radiation member side. Hereinafter, the first heat radiation member 23C and the second heat radiation member 24C according to the modification will be described. Note that the configurations other than the first heat radiation member 23C and the second heat radiation member 24C are the same as those described in Embodiment 2, and thus the description thereof will be omitted.

[0216] FIG. 22 is a perspective view of the first heat radiation member 23C according to a modification of Embodiment 2 as viewed from the negative z-axis side. FIG. 23 is a perspective view of the second heat radiation member 24C according to a modification of Embodiment 2 as viewed from the negative z-axis side. Note that the same elements as those in FIGS. 18 and 19 are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0217] [First heat radiation member 23C] The first heat radiation member 23C is arranged on the main surface side (the side of the fourth main surface 12) of the phosphor substrate 10B, similarly to the first heat radiation member 23B shown in FIG. 16, and is a disk-shaped plate material that is rotated about the center point C1 together with the second heat radiation member 24C and the phosphor substrate 10B. Also in this modification, the first heat radiation member 23C holds the phosphor substrate 10B by sandwiching and holding a region of about 5 mm from the inner diameter of the phosphor substrate 10B together with the second heat radiation member 24C.

[0218] As shown in FIG. 22, the first heat radiation member 23C includes a plurality of opening regions 201C and a plurality of screw holes 203.

[0219] Each of the plurality of opening regions 201C is provided in an inner ring region excluding the outer ring region 204 and the central portion 205 of the first heat radiation member 23B. More specifically, each of the plurality of opening regions 201C is provided in an inner ring region including a position corresponding to the opening 207C of the second heat radiation member 24C when the first heat radiation member 23C and the second heat radiation member 24C sandwich and hold the phosphor substrate 10B. In this modification, three opening regions 201C are provided as shown in FIG. 22.

[0220] The screw holes 203 are holes used to fix the first heat dissipation member 23C and the second heat dissipation member 24C by screwing. Also in this modified example, three screw holes 203 are provided in a region connecting the outer ring region 204 and the central portion 205 of the first heat dissipation member 23C. Thereby, the first heat dissipation member 23C and the second heat dissipation member 24C can sandwich and hold (clamp) the phosphor substrate 10B without using an adhesive member.

[0221] Note that the outer diameter, inner diameter, thickness, material, etc. of the first heat dissipation member 23C may be in the same size range as the first heat dissipation member 23B, so the description is omitted. However, since no heat dissipation fins are provided on the first heat dissipation member 23C, the thickness can be made thinner than that of the first heat dissipation member 23B. The thickness of the first heat dissipation member 23C can be appropriately determined as long as it can sandwich and hold (clamp) the phosphor substrate 10B and can rotate while maintaining rigidity.

[0222] [Second heat dissipation member 24C] The second heat dissipation member 24C is a disk-shaped member that is arranged on the opposite side (the side of the third main surface 11) of the main surface (the fourth main surface 12) of the phosphor substrate 10B, similar to the second heat dissipation member 24B shown in FIG. 16, and is rotated about the center point C1 together with the first heat dissipation member 23C and the phosphor substrate 10B. Also in this modified example, the second heat dissipation member 24C holds the phosphor substrate 10B by sandwiching and holding (clamping) a region about 5 mm from the inner diameter of the phosphor substrate 10B together with the first heat dissipation member 23C.

[0223] As shown in FIG. 23, the second heat dissipation member 24C includes a plurality of screw holes 203A, a plurality of heat dissipation fins 206C, an opening 207C, and a second through hole 208.

[0224] The screw hole 203A is a hole used to fix the first heat dissipation member 23C and the second heat dissipation member 24C by screwing. In this modification, the screw hole 203A is provided at a position corresponding to three of the plurality of heat dissipation fins 206C and the screw hole 203 of the first heat dissipation member 23C. Thereby, the first heat dissipation member 23C and the second heat dissipation member 24C can sandwich and hold (clamp) the phosphor substrate 10B without using an adhesive member.

[0225] Note that the screw hole 203A may be used to fix the disk portion 31, the first heat dissipation member 23C, and the second heat dissipation member 24C by screwing, similarly to the second embodiment.

[0226] The plurality of heat dissipation fins 206C are provided on the second heat dissipation member 24C so as to protrude in the direction opposite to the third main surface 11 of the phosphor substrate 10B. The plurality of heat dissipation fins 206C are provided radially with respect to the central axis (center point C1) in a region excluding the central portion of the second heat dissipation member 24C when the second heat dissipation member 24C is viewed in plan.

[0227] In this modification, as shown in FIG. 23, the plurality of heat dissipation fins 206C extend radially so as to spread at equal intervals with respect to the center point C1 in a region excluding the second through hole 208 of the second heat dissipation member 24C.

[0228] Further, the plurality of heat dissipation fins 206C are provided on the second heat dissipation member 24C so as to protrude in the direction opposite to the third main surface 11 (not shown) of the phosphor substrate 10B. That is, the plurality of heat dissipation fins 206C are erected so as to protrude in the negative z-axis direction. While the thicknesses of the plurality of heat dissipation fins 206C are the same, there are two widths in the widths of the plurality of heat dissipation fins 206C. That is, the three heat dissipation fins 206C screwed to the disk portion 31 of the rotating portion 30B are provided to be wider than the other heat dissipation fins 206C.

[0229] The second heat radiating member 24C has a plurality of heat radiating fins 206C, so that the surface area of the second heat radiating member 24C increases, and thus the heat radiation of the second heat radiating member 24C is promoted.

[0230] The opening 207C is provided in a region between the plurality of heat radiating fins 206C in the second heat radiating member 24C when the second heat radiating member 24C is viewed in plan. More specifically, the opening 207C is provided in a region between the plurality of heat radiating fins 206C in the second heat radiating member 24C in a circular region including the central axis of the second heat radiating member 24C and in a region (inner ring region) excluding the outer ring region 210 of the second heat radiating member 24C when the second heat radiating member 24C is viewed in plan. That is, as shown in FIG. 23, the opening 207C is provided in the inner ring region excluding the second through hole 208 and the outer ring region 210 of the second heat radiating member 24C.

[0231] Note that when the second heat radiating member 24C is viewed in plan, the larger the ratio of the opening 207C occupying the second heat radiating member 24C, the easier it is to cool the heat generated in the phosphor substrate 10B by the irradiation of the excitation light L1. Therefore, within the allowable strength range of the second heat radiating member 24C depending on the product to which the phosphor wheel 1B is applied, the width of the plurality of heat radiating fins 206C may be narrowed and the outer ring region 210 may be narrowed to maximize the ratio of the opening 207C.

[0232] As shown in FIG. 23 and the like, the second through hole 208 is a hole that penetrates the second heat radiating member 24C in the thickness direction (z-axis direction) of the second heat radiating member 24C. The second through hole 208 is provided at the center of the second heat radiating member 24C. The axis, which is the motor shaft of the rotating portion 30B, passes through and is fitted into the second through hole 208.

[0233] Here, the outer diameter and the inner diameter of the second heat radiating member 24C are approximately the same as the outer diameter and the inner diameter of the first heat radiating member 23C, and may be appropriately determined in the same manner as the outer diameter and the inner diameter of the second heat radiating member 24B. In the second heat radiating member 24C, the thickness of the heat radiating fin 206C and the thickness of the outer ring region 210 may be appropriately determined within the same thickness range as the heat radiating fin 22 and the main body portion 21 in the metal member 20 of the first embodiment, and thus the description here is omitted.

[0234] As described above, the phosphor wheel 1B according to this modification has the same configuration as the phosphor wheel 1B according to the second embodiment. The first heat dissipation member 23C and the second heat dissipation member 24C hold the phosphor substrate 10B by sandwiching it, and a plurality of heat dissipation fins are provided on one of the first heat dissipation member 23C and the second heat dissipation member 24C.

[0235] Thus, in this modification, the metal member 20B is composed of the first heat dissipation member 23C and the second heat dissipation member 24C, and by sandwiching the phosphor substrate 10B, it is possible to relieve the concentration of stress due to heat generated in the phosphor substrate 10B on the phosphor substrate 10B by the irradiation of the excitation light L1. Therefore, it is possible to suppress the risk of damage due to stress concentration on the phosphor substrate 10B.

[0236] Here, in the phosphor wheel 1B according to this modification, the plurality of heat dissipation fins 206C are provided on the second heat dissipation member 24C so as to protrude in the direction opposite to the main surface of the phosphor substrate 10B. When the second heat dissipation member 24C is viewed in plan, an opening 207C is provided in the region between the plurality of heat dissipation fins 206C in the second heat dissipation member 24C.

[0237] Thus, by having the plurality of openings 207C, the second heat dissipation member 24C can cause the airflow generated when the phosphor substrate 10B and the like are rotated by the rotating portion 30B to pass through the plurality of openings 207C and move from the positive z-axis side to the negative z-axis side of the phosphor substrate 10B.

[0238] Here, an opening region 201C is provided in the inner ring region including the position corresponding to the opening 207C of the second heat dissipation member 24C when the first heat dissipation member 23C and the second heat dissipation member 24C sandwich and hold the phosphor substrate 10B. Thereby, the airflow generated when the phosphor substrate 10B and the like are rotated by the rotating portion 30B can be made to pass through the opening region 201C and the plurality of openings 207C and move from the positive z-axis side to the negative z-axis side of the phosphor substrate 10B.

[0239] Therefore, the heat generated in the phosphor substrate 10B by the irradiation of the excitation light L1 is transmitted to the metal member 20B in contact with the phosphor substrate 10B, that is, the first heat dissipation member 23C and the second heat dissipation member 24C, and is cooled by the airflow passing through the opening region 201C and the opening 207C and the heat dissipation fins 206C. That is, since the heat from the phosphor substrate 10B is more easily dissipated, the temperature rise of the phosphor substrate 10B due to the irradiation of the excitation light L1 can be suppressed. As a result, since the temperature quenching phenomenon is less likely to occur, the decrease in fluorescence is suppressed.

[0240] Here, each of the plurality of openings 207C is provided in a region between the plurality of heat dissipation fins 206C in the second heat dissipation member 24C in a region excluding the central portion of the second heat dissipation member 24C and the outer ring region 210 of the second heat dissipation member 24C when the second heat dissipation member 24C is viewed in plan. In this way, by providing the plurality of openings 207C in the second heat dissipation member 24C, the airflow generated when the phosphor substrate 10B and the like are rotated by the rotating portion 30B and passing through the first heat dissipation member 23C can be directed from the positive z-axis side to the negative z-axis side of the phosphor substrate 10B.

[0241] Further, in this modification, the plurality of heat dissipation fins 206C are provided radially with respect to the central axis in a region excluding the central portion of the second heat dissipation member 24C when the metal member 20B is viewed in plan. Thereby, when the phosphor substrate 10B and the like are rotated by the rotating portion 30B, a strong airflow with a higher flow velocity can be generated, so that the heat dissipation performance of the phosphor wheel 1B, that is, the transmissive fluorescence emission module, can be further improved.

[0242] Note that in the above modification, the plurality of heat dissipation fins 206C have been described as being provided so as to spread at equal intervals and extend radially, but it is not limited thereto. A plurality of heat dissipation fins in the shape of a multi-wing fan may be formed.

[0243] More specifically, each of the plurality of heat dissipation fins 206C may be provided in an arc shape that is concave and curved in the rotational direction of the second heat dissipation member 24C in a region excluding the central portion of the second heat dissipation member 24C when the second heat dissipation member 24C is viewed in a plan view. Note that, for the shape of each of the plurality of heat dissipation fins 206C, it may be formed such that the angle formed by the line extending the heat dissipation fin 206C and the tangent line of the second heat dissipation member 24C is greater than 90 degrees with respect to the rotational direction.

[0244] With such a configuration, when the phosphor substrate 10B or the like is rotated by the rotating portion 30B, the second heat dissipation member 24C can generate a stronger air flow (air current) with a higher flow velocity. Therefore, the heat dissipation performance of the phosphor wheel 1B, that is, the transmissive fluorescence emission module, can be further enhanced.

[0245] (Other embodiments) As described above, the phosphor wheel and the like according to the present invention have been described based on the embodiments and modification examples. However, the present invention is not limited to these embodiments and modification examples. As long as the gist of the present invention is not deviated from, various modifications conceived by those skilled in the art applied to the embodiments and modification examples, and other forms constructed by combining some of the components in the embodiments and modification examples are also included in the scope of the present invention.

[0246] For example, the above-described embodiments and modification examples are merely examples, and it goes without saying that various changes, additions, omissions, etc. are possible.

[0247] Also, for example, forms realized by arbitrarily combining the components and functions shown in the above-described embodiments and modification examples are also included in the scope of the present disclosure. In addition, forms obtained by applying various modifications conceived by those skilled in the art to the above-described embodiments and modification examples, and forms realized by arbitrarily combining the components and functions in each embodiment without departing from the gist of the present disclosure are also included in the present disclosure. Further, for example, it is also possible to combine the components described in the embodiments and modification examples to form a new embodiment.

[0248] In addition, among the components described in the accompanying drawings and the detailed description, there may be not only the components essential for solving the problem, but also the components not essential for solving the problem for the purpose of exemplifying the above technology. Therefore, just because those non-essential components are described in the accompanying drawings or the detailed description, it should not be immediately determined that those non-essential components are essential.

Explanation of Signs

[0249] 1B Phosphor wheel 10B Phosphor substrate 20B Metal member 30B Rotating part 23B, 23C First heat dissipation member 24B, 24C Second heat dissipation member 201 Region 202, 206C Heat dissipation fins 204, 210 Outer ring region 205 Central part 207C Opening 201C, 207 Opening region A11 Annular region L1 Excitation light

Claims

1. A transmissive phosphor wheel, comprising: a phosphor substrate which is an annular substrate mainly composed of a phosphor material; a metal member that holds in contact with the phosphor substrate; a rotating part that rotates the phosphor substrate and the metal member about an axis extending in the thickness direction of the phosphor substrate; when the phosphor substrate is viewed in plan view, the phosphor substrate has an annular region that does not overlap with the metal member; the metal member comprises a first heat dissipation member disposed on the main surface side of the phosphor substrate, and a second heat dissipation member disposed on the opposite side of the main surface of the phosphor substrate; the first heat dissipation member and the second heat dissipation member hold the phosphor substrate by sandwiching the phosphor substrate therebetween; one of the first heat dissipation member and the second heat dissipation member is provided with a plurality of heat dissipation fins; the plurality of heat dissipation fins are provided by raising a plurality of regions in an inner ring region excluding a central portion and an outer ring region of the first heat dissipation member; an opening region is provided in an inner ring region of the second heat dissipation member; when the phosphor substrate is viewed in plan view, the positions of the plurality of heat dissipation fins and the position of the opening region correspond to each other; a phosphor wheel.

2. The thickness of an outer ring region of the second heat dissipation member is provided to be lower than a height of the plurality of heat dissipation fins provided on the first heat dissipation member. The phosphor wheel according to claim 1.

3. The thickness of an outer ring region of the second heat dissipation member is provided to be lower than a height of the plurality of heat dissipation fins raised in the first heat dissipation member, and an opening region is provided in an inner ring region of the second heat dissipation member, the opening region allowing the plurality of heat dissipation fins to protrude from the second heat dissipation member when the first heat dissipation member and the second heat dissipation member hold the phosphor substrate. The phosphor wheel according to claim 2.

4. A transmissive phosphor wheel, comprising: a phosphor substrate which is an annular substrate mainly composed of a phosphor material; a metal member that holds in contact with the phosphor substrate; a rotating part that rotates the phosphor substrate and the metal member about an axis extending in the thickness direction of the phosphor substrate; when the phosphor substrate is viewed in plan view, the phosphor substrate has an annular region that does not overlap with the metal member; the metal member comprises a first heat dissipation member disposed on the main surface side of the phosphor substrate, and a second heat dissipation member disposed on the opposite side of the main surface of the phosphor substrate; The first heat radiating member and the second heat radiating member hold the phosphor substrate by sandwiching the phosphor substrate therebetween. One of the first heat radiating member and the second heat radiating member is provided with a plurality of heat radiating fins. The plurality of heat radiating fins are provided on the second heat radiating member so as to protrude in a direction opposite to the main surface of the phosphor substrate. When the second heat radiating member is viewed in a plan view, an opening is provided in a region between the plurality of heat radiating fins in the second heat radiating member. The opening is provided in a region between the plurality of heat radiating fins in the second heat radiating member in a region excluding a central portion of the second heat radiating member and an outer ring region of the second heat radiating member when the second heat radiating member is viewed in a plan view. Each of the plurality of heat radiating fins is provided in an arc shape that is concave and curved in a rotational direction of the second heat radiating member in a region excluding a central portion of the second heat radiating member when the second heat radiating member is viewed in a plan view. Phosphor wheel.

5. The plurality of heat radiating fins are provided radially with respect to a central axis of the second heat radiating member in a region excluding a central portion of the second heat radiating member when the second heat radiating member is viewed in a plan view. The phosphor wheel according to claim 4.

6. A transmissive phosphor wheel, comprising: a phosphor substrate which is an annular substrate composed mainly of a phosphor material; a metal member that contacts and holds the phosphor substrate; a rotating portion that rotates the phosphor substrate and the metal member about an axis extending in a thickness direction of the phosphor substrate, When the phosphor substrate is viewed in a plan view, the phosphor substrate has an annular region that does not overlap with the metal member. The metal member is a first heat radiating member disposed on a main surface side of the phosphor substrate; a second heat radiating member disposed on a side opposite to the main surface of the phosphor substrate, The first heat radiating member and the second heat radiating member hold the phosphor substrate by sandwiching the phosphor substrate therebetween. One of the first heat radiating member and the second heat radiating member is provided with a plurality of heat radiating fins. The plurality of heat radiating fins are provided on the second heat radiating member so as to protrude in a direction opposite to the main surface of the phosphor substrate. When the second heat radiating member is viewed in a plan view, an opening is provided in a region between the plurality of heat radiating fins in the second heat radiating member. In an inner ring region of the first heat radiating member including a position corresponding to the opening when the first heat radiating member and the second heat radiating member hold the phosphor substrate, an opening region is provided. Phosphor wheel. Claim 7 A light emitting device comprising the phosphor wheel according to claim 6. Light emitting device.

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