Phosphor wheel and light emitting device

Abstract

To provide a phosphor wheel and a light-emitting device having high light utilization efficiency.SOLUTION: The phosphor wheel 1B is a transmissive phosphor wheel 1B, and is disposed to be bonded to a phosphor substrate 10B that is a substrate made of only a phosphor material, and a main surface of the phosphor substrate 10B, A light source device includes a metallic member 20B provided with a plurality of first heat radiation fins 202 so as to protrude in a direction opposite to a main surface, and a rotator 30B that rotates the phosphor substrate 10B and the metallic member 10B around a shaft extending in a thickness direction of the phosphor substrate 20B, wherein the phosphor substrate 10B has an annular region 10B that does not overlap with the metallic member 20B in a plan view of the phosphor substrate A11, and an opening 206 is provided in a region between the plurality of first heat radiation fins 202 in the metallic member in a plan view of the metallic member. 20B 20B.SELECTED DRAWING: Figure 16

Description

[Technical Field]

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

[0002] 2. Description of the Related Art Conventionally, a transmissive fluorescent light emitting module (phosphor wheel) that emits fluorescent light when excited by excitation light has been known. The transmissive fluorescent light emitting module is applied to light emitting devices such as projectors.

[0003] As an example of a transmissive fluorescence-emitting module, a light source device is disclosed in Patent Document 1. This light source device (transmissive fluorescence-emitting module) includes a phosphor substrate made of a plate-shaped glass member, a fluorescence generating unit, a dichroic film positioned between the phosphor substrate and the fluorescence-emitting unit, and a light emitting unit that emits excitation light that excites the fluorescence generating unit. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-9242 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, it is known that when the temperature of the fluorescence generating unit increases due to irradiation with excitation light, a phenomenon occurs in which the amount of fluorescence generated decreases (so-called thermal quenching). For example, in the transmissive fluorescence emitting module disclosed in Patent Document 1, the thermal quenching phenomenon is likely to occur because the heat dissipation of the fluorescence generating unit is insufficient, and as a result, the fluorescence emitted from the fluorescence emitting unit decreases. Therefore, in such a transmissive fluorescence emitting module, the light utilization efficiency may be low.

[0006] Therefore, the present invention provides a phosphor wheel and a light emitting device that have high light utilization efficiency. [Means for solving the problem]

[0007] A phosphor wheel according to one embodiment of the present invention is a transmissive phosphor wheel comprising: a phosphor substrate, which is a substrate made only of phosphor material; a metal member bonded to a main surface of the phosphor substrate and having a plurality of first heat dissipation fins protruding in the opposite direction from the main surface; and a rotating unit that rotates the phosphor substrate and the metal member around an axis extending in the thickness direction of the phosphor substrate. When the phosphor substrate is viewed in a plane, the phosphor substrate has a circular ring-shaped region that does not overlap with the metal member, and when the metal member is viewed in a plane, an opening is provided in the region between the plurality of first heat dissipation fins in the metal member. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a phosphor wheel and a light emitting device with high light utilization efficiency. [Brief explanation of the drawings]

[0009] [Figure 1A] FIG. 1A is a perspective view of a transmissive fluorescence emission module according to a first embodiment. [Figure 1B] FIG. 1B is an exploded perspective view of the transmissive fluorescence emission module according to the first embodiment. [Figure 2] FIG. 2 is a plan view of the phosphor substrate, the metal member, and the rotating portion according to the first embodiment. [Figure 3] FIG. 3 is a bottom view of the phosphor substrate and the metal member according to the first embodiment. [Figure 4] FIG. 4 is a cross-sectional view showing a cut surface of a part of the transmissive fluorescent light-emitting module taken along line IV-IV in FIG. 1A. [Figure 5] FIG. 5 is a perspective view showing the appearance of the projector according to the first embodiment. [Figure 6] FIG. 6 is a schematic diagram showing a transmissive fluorescent light emitting module in the projector according to the first embodiment. [Figure 7]FIG. 7 is a perspective view showing a housing according to the first embodiment. [Figure 8] FIG. 8 is a plan view of the phosphor substrate, metal member, and rotating part included in the transmissive fluorescence light-emitting module according to the study example. [Figure 9] FIG. 9 is a plan view of the phosphor substrate, the metal member, and the rotating portion according to the first embodiment. [Figure 10] FIG. 10 is a perspective view of a phosphor substrate, a metal member, and a rotating part included in a transmissive fluorescence light-emitting module according to a study example. [Figure 11] FIG. 11 is a perspective view of the phosphor substrate, the metal member, and the rotating portion according to the first embodiment. [Figure 12] FIG. 12 is a diagram showing the temperature profile of the phosphor substrate according to the study example and the first embodiment. [Figure 13A] FIG. 13A is a perspective view of a transmissive fluorescence emission module according to a first modification of the first embodiment. [Figure 13B] FIG. 13B is an exploded perspective view of the transmissive fluorescence emission module according to the first modification of the first embodiment. [Figure 14] FIG. 14 is a perspective view of a transmissive fluorescence light-emitting module according to the second modification of the first embodiment. [Figure 15] FIG. 15 is a bottom view of a phosphor substrate and a metal member according to the third modification of the first embodiment. [Figure 16] FIG. 16 is a perspective view of a phosphor wheel according to the second embodiment. [Figure 17] FIG. 17 is a front view of a phosphor substrate according to the second embodiment. [Figure 18] FIG. 18 is a side view of the phosphor substrate shown in FIG. [Figure 19] FIG. 19 is a perspective view of the metal member according to the second embodiment as viewed from the negative side of the z axis. [Figure 20] FIG. 20 is a perspective view of the metal member according to the second embodiment as viewed from the positive side of the z axis. [Figure 21] 21 is a partially enlarged side view of the metal member of FIG. 20. FIG. [Figure 22]FIG. 22 is a diagram showing the verification results of the actual prototype of the phosphor wheel according to the second embodiment. [Figure 23A] FIG. 23A is a diagram showing a metal member used in a prototype according to Comparative Example 1. FIG. [Figure 23B] FIG. 23B is a diagram showing a metal member used in a prototype according to the second embodiment. [Figure 24] FIG. 24 is a diagram showing another verification result of the actual prototype of the phosphor wheel according to the second embodiment. [Figure 25] FIG. 25 is a diagram showing a cut surface used in the analysis of the metal member according to the second embodiment. [Figure 26] FIG. 26 is a diagram showing an analysis result of a fluid flow near an opening of a metal member according to the second embodiment. [Figure 27] FIG. 27 is a perspective view of a metal member according to a modification of the second embodiment, as viewed from the negative side of the z axis. [Figure 28] FIG. 28 is a diagram for explaining the conditions for the shape of the first heat dissipation fin shown in FIG. [Figure 29] FIG. 29 is a perspective view of the metal member according to the third embodiment as viewed from the negative side of the z axis. [Figure 30] FIG. 30 is a perspective view of the metal member according to the third embodiment as viewed from the positive side of the z axis. [Figure 31] FIG. 31 is a side view of a metal member according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, a transmissive fluorescent light emitting module according to an embodiment of the present invention will be described in detail with reference to the drawings.

[0011] The embodiments described below are all comprehensive or specific examples, and the numerical values, shapes, materials, components, arrangement and connection of the components, manufacturing processes, and the order of the manufacturing processes shown in the following embodiments are merely examples and are not intended to limit the present invention.

[0012] Furthermore, each figure is a schematic diagram and is not necessarily an exact illustration. Therefore, for example, the scales of the figures do not necessarily match. Furthermore, in each figure, substantially the same components are given the same reference numerals, and redundant explanations are omitted or simplified.

[0013] In this specification, terms indicating the relationship between elements, such as parallel or perpendicular, terms indicating the shape of elements, such as circular, and numerical ranges are not expressions that only express a strict meaning, but are expressions that also include a substantially equivalent range, for example, a difference of about a few percent.

[0014] In the present specification and drawings, the x-axis, y-axis, and z-axis represent three axes of a three-dimensional Cartesian coordinate system. In the embodiment, the x-axis and y-axis are two axes parallel to the third main surface of the phosphor substrate, and the z-axis is an axis perpendicular to the x-axis and y-axis.

[0015] (Embodiment 1) [composition] First, the configuration of a transmissive fluorescence emitting module 1 according to the present embodiment will be described with reference to the drawings. Fig. 1A is a perspective view of the transmissive fluorescence emitting module 1 according to the present embodiment. Fig. 1B is an exploded perspective view of the transmissive fluorescence emitting module 1 according to the present embodiment.

[0016] As shown in FIGS. 1A and 1B, the transmissive fluorescence light-emitting module 1 is a module including a phosphor substrate 10 made of a phosphor material, a metal member 20, a rotating section 30, and two light-emitting sections 200. For simplicity, only one light-emitting section 200 is shown in FIGS. 1A and 1B. This may also be the case in the following figures. The transmissive fluorescence light-emitting module 1 may also include only one light-emitting section 200. The transmissive fluorescence light-emitting module 1 is used in light-emitting devices such as projectors and lighting devices, for example. In this embodiment, the transmissive fluorescence light-emitting module 1 is used in a projector.

[0017] In this embodiment, rotating unit 30 rotates phosphor substrate 10 and other components around axis B1 in the direction of arrow R shown in FIG. 1A, and phosphor substrate 10 receives excitation light L1 and emits transmitted light L2 containing fluorescence. Transmissive fluorescence light-emitting module 1 is a light-transmitting module that uses transmitted light L2 as projection light output by the projector. In other words, phosphor substrate 10 is used as a light-transmitting phosphor wheel.

[0018] The components of the transmissive fluorescence emission module 1 will be described below.

[0019] First, the light emitting section 200 will be described.

[0020] 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 that constitutes 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).

[0021] In this 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) made of a nitride semiconductor material. In this embodiment, the light emitting unit 200, which is a semiconductor laser light source, is a TO-can type light emitting device integrated with a collimating lens. The light emitting unit 200 may be a multi-chip type laser as disclosed in JP 2016-219779 A, ​​or the collimating lens and the TO-can may be separate entities.

[0022] For example, the light emitting unit 200 emits laser light in the near-ultraviolet to blue range having a peak wavelength of 380 nm to 490 nm as the excitation light L1. In this case, the peak wavelength of the excitation light L1 is, for example, 455 nm, and the excitation light L1 is blue light.

[0023] Next, the phosphor substrate 10 will be described.

[0024] The phosphor substrate 10 is a flat substrate having two main surfaces facing back to back. The two main surfaces are a third main surface 11 and a fourth main surface 12. Here, the third main surface 11 and the fourth main surface 12 are flat surfaces.

[0025] Further, the phosphor substrate 10 will be described in detail with reference to FIGS.

[0026] FIG. 2 is a plan view of the phosphor substrate 10, metal member 20, and rotating unit 30 according to this embodiment. The light-emitting unit 200 is omitted from FIG. 2. FIG. 3 is a bottom view of the phosphor substrate 10 and metal member 20 according to this embodiment. The rotating unit 30 and light-emitting unit 200 are omitted from FIG. 3. Note that the transmissive fluorescence-emitting module 1 viewed from the negative direction of the z axis is referred to as a plan view, and the transmissive fluorescence-emitting module 1 viewed from the positive direction of the z axis is referred to as a bottom view. The viewpoint in the plan view is referred to as a plan view, and the viewpoint in the bottom view is referred to as a bottom view.

[0027] The phosphor substrate 10 is a substrate having a circular shape in a plan view, that is, a disk shape. Here, the center of the circle of the phosphor substrate 10 is defined as a center point C1. Furthermore, the phosphor substrate 10 is provided with a first through-hole H1, and therefore, more specifically, the shape of the phosphor substrate 10 is annular. 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 a plan view. The center of the circle of the first through-hole H1 coincides with the center point C1. In other words, the phosphor substrate 10 is provided in a circular ring shape on a circumference at an equal distance from the center point C1 of the phosphor substrate 10, and is provided in a band shape along the circumferential direction in a plan view.

[0028] The outer diameter of the annular phosphor substrate 10 (i.e., the diameter of the outer circle when viewed from below in FIG. 3) is, for example, but not limited to, preferably 30 mm to 90 mm, more preferably 35 mm to 70 mm, and even more preferably 40 mm to 50 mm. When the transmissive fluorescence light-emitting module 1 is applied to a projector, the outer diameter of the phosphor substrate 10 is determined so that it will fit into a housing provided in the projector.

[0029] The inner diameter of the phosphor substrate 10 (i.e., the diameter of the inner circle when viewed from below in FIG. 3) is smaller than the outer diameter of the phosphor substrate 10, and is preferably 15 mm to 45 mm, more preferably 17.5 mm to 35 mm, and even more preferably 20 mm to 25 mm, but is not limited to these. The inner diameter of the phosphor substrate 10 is also the diameter of the first through-hole H1.

[0030] The thickness of the phosphor substrate 10 (i.e., the length in the z-axis direction) is preferably 50 μm or more and 700 μm or less, more preferably 80 μm or more and 500 μm or less, and even more preferably 100 μm or more and 300 μm or less.

[0031] The phosphor substrate 10 is made of a phosphor material. That is, the phosphor substrate 10 is a member made only of a phosphor material, which is a main component. More specifically, the phosphor substrate 10 is a substrate made of a sintered phosphor that is made only of a phosphor material.

[0032] The sintered phosphor in this specification will now be described.

[0033] A sintered phosphor is a fired body obtained by firing raw material powder of a phosphor material (for example, a granulated body obtained by granulating raw material powder of a phosphor material), which is the above-mentioned main component, 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 together. More specifically, the sintered phosphor does not require any binder at all. As an example, in the above-mentioned Patent Document 1, the binder is a transparent resin. The binder is a known material such as an Al2O3 material and a glass material (that is, SiO d (0 < d ≤ 2)) and the like are used. 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.

[0034] For example, when the total volume of the sintered phosphor is 100 vol%, it is preferable that the volume of the phosphor material in the total volume of the sintered phosphor is 70 vol% or more. Also, it is better that the volume of the phosphor material in the total volume of the sintered phosphor is 80 vol% or more, even better at 90 vol% or more, and even better still at 95 vol% or more.

[0035] In other words, when the total volume of the sintered phosphor is 100 vol%, it is preferable that the volume of other materials (for example, a binder) in the total volume of the sintered phosphor is less than 30 vol%. Also, it is better that the volume of other materials (for example, a binder) in the total volume of the sintered phosphor is 20 vol% or less, even better at 10 vol% or less, and even better still at 5 vol% or less.

[0036] When the vol% of other materials in the entire volume of the sintered phosphor is high (i.e., the volume ratio of other materials is high), phonon scattering occurs due to defects present 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. In addition, non-radiative recombination at the interface also increases, resulting in a decrease in luminous efficiency. In other words, the lower the vol% of other materials in the entire volume of the sintered phosphor (i.e., the smaller the volume ratio of other materials), the more improved the thermal conductivity and luminous efficiency. For the above reasons, the sintered phosphor of the present invention has a volume of other materials in the entire volume of the sintered phosphor that is less than 30%.

[0037] Here, the phosphor material will be described.

[0038] The phosphor material is, for example, a material composed of a crystalline phase having a garnet structure. The garnet structure is A3B2C3O 12 The crystal structure is expressed by the general formula: Element A is a rare earth element such as Ca, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, and Lu, element B is an element such as Mg, Al, Si, Ga, and Sc, and element C is an element such as Al, Si, and Ga. Examples of such garnet structures include YAG (yttrium aluminum garnet), LuAG (lutetium aluminum garnet), and Lu2CaMg2Si3O. 12 (Lutetium Calcium Magnesium Silicon Garnet) and TAG (Terbium Aluminum Garnet). In this embodiment, the phosphor material is (Y 1-x Ce x )3Al2Al3O 12 (That is, (Y 1-x Ce x )3AlO 12)(0.0001 ≦ x < 0.1), that is, it is composed of a crystal phase represented by YAG.

[0039] Further, 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 as the unreacted raw material in the total volume of the sintered phosphor is 5 vol% or less.

[0040] Note that the crystal phase constituting the phosphor material may be a solid solution of a plurality of garnet crystal phases having different chemical compositions. Such solid solutions include (Y 1-x Ce x )3Al2Al3O 12 a garnet crystal phase represented by (0.001 ≦ x < 0.1) and (Lu 1-y Ce y )3Al2Al3O 12 a solid solution of a garnet crystal phase represented by (0.001 ≦ y < 0.1) ((1 - a)(Y 1-x Ce x )3Al5O 12 ·a(Lu 1-y Ce y )3Al2Al3O 12 (0 < a < 1)). Also, such solid solutions include (Y 1-x Ce x )3Al2Al3O 12 a garnet crystal phase represented by (0.001 ≦ x < 0.1) and (Lu 1-z Ce z )2CaMg2Si3O 12 a solid solution of a garnet crystal phase represented by (0.0015 ≦ z < 0.15) ((1 - b)(Y 1-x Ce x )3Al2Al3O 12 ·b(Lu 1-z Ce z )2CaMg2Si3O 12Examples include (0 < b < 1). Since the phosphor material is 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 wider, 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.

[0041] In addition, the crystal phase constituting the phosphor material may contain a crystal phase with a chemical composition deviated from the crystal phase represented by the general formula A3B2C3O 12 Examples of such crystal phases include a crystal phase rich in Al with respect to the crystal phase represented by (Y 1-x Ce x )3Al2Al3O 12 (0.001 ≤ x < 0.1), which is (Y 1-x Ce x )3Al 2+δ Al3O 12 (δ is a positive number). Examples of such crystal phases also include a crystal phase rich in Y with respect to the crystal phase represented by (Y 1-x Ce x )3Al2Al3O 12 (0.001 ≤ x < 0.1), which is (Y 1-x Ce x ) 3+ζ Al2Al3O 12 (ζ is a positive number), etc. These crystal phases have a chemical composition deviated from the crystal phase represented by the general formula A3B2C3O 12 but maintain the garnet structure.

[0042] Furthermore, the crystal phase constituting the phosphor material may contain a heterogeneous phase having a structure other than the garnet structure.

[0043] In addition, when viewed from above, 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 two circles indicated by dashed lines. The center of the annular shape of the region A1 overlaps with the center point C1 of the phosphor substrate 10. Furthermore, excitation light L1 is incident on the region A1. More specifically, the excitation light L1 emitted from the light emitting portion 200 enters the region A1 from the third main surface 11 side (i.e., the negative side of the z-axis).

[0044] In region A1 of phosphor substrate 10, the phosphor material made of YAG receives excitation light L1 and emits fluorescence. More specifically, when excitation light L1 is irradiated onto the phosphor material, fluorescence is emitted from the phosphor material as wavelength-converted light. In other words, the wavelength-converted light emitted from the phosphor material is light with a longer wavelength than the wavelength of excitation light L1.

[0045] In this embodiment, the wavelength-converted light emitted from the phosphor material includes yellow fluorescence. The phosphor material, for example, absorbs light with a wavelength of 380 nm or more and 490 nm or less, and emits yellow fluorescence with a peak fluorescence wavelength in the wavelength range of 490 nm or more and 580 nm or less. By using YAG as the phosphor material, it is possible to easily emit fluorescence with a peak fluorescence wavelength in the wavelength range of 490 nm or more and 580 nm or less.

[0046] 1A, 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. 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. The transmitted light L2 that passes through the phosphor substrate 10 contains fluorescence, which is wavelength-converted yellow light, and excitation light L1, which is wavelength-unconverted blue light. In other words, the transmitted light L2 is a combination of these lights, and is white light.

[0047] Furthermore, the phosphor substrate 10 does not need to be supported by other components. In other words, the phosphor substrate 10 has rigid properties. When the phosphor substrate 10 is a sintered phosphor and the thickness of the phosphor substrate 10 is within the above range, the phosphor substrate 10 has rigid properties. Furthermore, compared to the fluorescence generating section formed from paint containing a phosphor and a transparent resin as disclosed in Patent Document 1, the phosphor substrate 10 according to this embodiment has much more rigid properties.

[0048] Next, the metal member 20 will be described.

[0049] The metal member 20 is a component made of a metal material. The metal member 20 is a member bonded to one of the main surfaces of the phosphor substrate 10. In this embodiment, as shown in FIGS. 1A and 1B, the metal member 20 is located on the negative side of the z-axis relative to the phosphor substrate 10, and is bonded to the third main surface 11. As will be described in detail later, the material used for the metal member 20 is aluminum, which is lightweight and has high thermal conductivity, in consideration of the load on the rotating part 30, which is a motor, and thermal conductivity.

[0050] In this embodiment, the metal member 20 is bonded to the third main surface 11 of the phosphor substrate 10 via a bonding layer. In this case, a silicone resin is used as the bonding layer to mitigate the difference in thermal expansion coefficient between the rotating portion 30 and the phosphor substrate 10. However, the rotating portion 30 may be made of other materials, such as Cu or Fe, and the adhesive may be other epoxy resins or highly thermally conductive adhesives containing nano-Ag or nano-Cu. The thickness of the bonding layer may be 5 μm to 40 μm, preferably 10 μm to 20 μm. The metal member 20 may be directly attached to 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 with bolts or screws. In a sandwich structure without using an adhesive, the other member is preferably made of metal from the perspective of heat dissipation, but may also be made of a resin material.

[0051] Furthermore, the metal member 20 according to this embodiment has a main body portion 21 and a plurality of first heat dissipation fins 22.

[0052] The main body 21 is a flat-plate-shaped member that is laminated on the phosphor substrate 10. The main body 21 has two main surfaces that face 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 that are parallel to each other. In this embodiment, the main body 21 is bonded 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 21 is bonded to the third main surface 11 of the phosphor substrate 10 via a bonding layer. The flat-plate shape of the main body 21 increases the bonding area between the phosphor substrate 10 and the metal member 20 (here, the main body 21). The flat-plate shape of the main body 21 is not limited to a rectangular parallelepiped shape, but also includes a cylindrical shape, a truncated cone shape, and the like.

[0053] 2 and 3, the shape of the main body portion 21 is circular in plan view and bottom view. 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. In other words, the shape of the main body portion 21 is a truncated cone. The truncated cone-shaped main body portion 21 has a first side surface portion 213. The first side surface portion 213 is an inclined surface that widens from the second main surface 212 toward the first main surface 211. The inclined first side surface portion 213 is not parallel to the z-axis.

[0054] Furthermore, since the second through-hole H2 is provided in the main body 21, the shape of the main body 21 is a truncated cone shape in which the second through-hole H2 is provided. Furthermore, the shape of the main body 21 is annular in plan view and bottom view. The second through-hole H2 is a hole that penetrates the main body 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 21 overlaps with the center point C1 of the phosphor substrate 10.

[0055] The outer diameter of the main body 21 is smaller than the outer diameter of the phosphor substrate 10. Here, the outer diameter of the main body 21 means the diameter of the first main surface 211 of the main body 21. The outer diameter of the main body 21 is, for example, preferably 20 mm to 70 mm, more preferably 25 mm to 55 mm, and even more preferably 30 mm to 40 mm, but is not limited to these. In this embodiment, the outer diameter of the main body 21 is 34 mm, that is, the radius of the main body 21 is 17 mm.

[0056] The inner diameter of the main body 21 only needs to be smaller than the outer diameter of the main body 21, and here is the same as the inner diameter of the phosphor substrate 10, but is not limited to this. The inner diameter of the main body 21 is also the diameter of the second through hole H2.

[0057] 2 and 3, in plan view and bottom view, a portion of the first through hole H1 and a portion of the second through hole H2 overlap. More specifically, in plan view, the entire first through hole H1 and the entire second through hole H2 overlap. In other words, the diameter of the first through hole H1 (the inner diameter of the phosphor substrate 10) and the diameter of the second through hole H2 (the inner diameter of the main body portion 21) are equal. Furthermore, in plan view and bottom view, the center of the circle of the first through hole H1 and the center of the circle of the second through hole H2 overlap with the center point C1 of the phosphor substrate 10.

[0058] The transmissive fluorescence-emitting module 1 according to this embodiment includes a phosphor substrate 10 and a metal member 20. The metal member 20 is bonded to the third main surface 11 of the phosphor substrate 10. Therefore, even if heat is generated in the phosphor substrate 10 due to irradiation with excitation light L1, the heat is easily transferred from the phosphor substrate 10 to the metal member 20. Furthermore, the metal material constituting the metal member 20 generally has a higher thermal conductivity than phosphor materials such as YAG. This allows the heat to easily transfer within the metal member 20 and be easily dissipated from the surface of the metal member 20 exposed to the air. In other words, by configuring the phosphor substrate 10 and the metal member 20 as described above, the heat is easily dissipated from the phosphor substrate 10. In other words, the heat dissipation properties of the phosphor substrate 10 can be improved.

[0059] Here, the effects of the transmissive fluorescence emitting module 1 according to this embodiment will be described.

[0060] As described above, in the transmissive fluorescence light-emitting module disclosed in Patent Document 1, if thermal quenching occurs, the light utilization efficiency will decrease. However, in the present embodiment, the heat is easily dissipated from the phosphor substrate 10, so that the temperature rise of the phosphor substrate 10 due to irradiation with excitation light L1 can be suppressed. As a result, thermal quenching is less likely to occur, and the decrease in fluorescence is suppressed.

[0061] Moreover, the transmissive fluorescence-emitting module 1 according to this embodiment does not include any component for supporting the phosphor substrate 10. Such a component is, for example, the phosphor substrate disclosed in Patent Document 1. This phosphor substrate is a substrate made of a plate-shaped glass member that supports the fluorescence generating unit and the like.

[0062] Here, the behavior of light disclosed in Patent Document 1 will be explained. Patent Document 1 discloses that excitation light is incident on the phosphor substrate from the atmosphere. Furthermore, the excitation light incident on the phosphor substrate passes through the phosphor substrate and enters the fluorescence generating unit, where fluorescence is generated. However, in Patent Document 1, due to the difference between the refractive index of the phosphor substrate and that of the atmosphere, a portion of the excitation light incident on the phosphor substrate from the atmosphere is reflected toward the atmosphere. In other words, optical loss of the excitation light occurs at the interface between the phosphor substrate and the atmosphere. As a result, compared to when a portion of the excitation light is not reflected, less excitation light enters the fluorescence generating unit, and therefore less fluorescence is generated in the fluorescence generating unit. In other words, the transmissive fluorescence-emitting module disclosed in Patent Document 1 has the problem of low light utilization efficiency.

[0063] In contrast to this, in the present embodiment, as described above, the transmissive fluorescence-emitting module 1 according to the present embodiment does not include a component for supporting the phosphor substrate 10 (for example, the phosphor substrate described above). Therefore, there is no optical loss of the excitation light L1 as described above, and 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.

[0064] In summary, in the transmissive fluorescence emission module 1 according to this embodiment, the temperature quenching phenomenon is unlikely to occur and there is no optical loss of the excitation light L1, so that the light utilization efficiency can be improved.

[0065] In this embodiment, the metal member 20 has a main body portion 21.

[0066] The main body 21 having the above configuration increases the area where the phosphor substrate 10 and the metal member 20 (here, the main body 21) are joined together. Therefore, even if heat is generated in the phosphor substrate 10 due to irradiation with the excitation light L1, the heat is more easily dissipated from the phosphor substrate 10.

[0067] Here, the thickness D21 of the main body 21 will be described with reference to FIG.

[0068] Fig. 4 is a cross-sectional view showing a cut surface of a part of the transmissive fluorescence emission module 1 taken along the line IV-IV in Fig. 1A. Note that Fig. 4 shows a side view of the light emitting section 200.

[0069] The thickness D21 (length in the z-axis direction) of the main body 21 is preferably thicker than the thickness of the phosphor substrate 10. This improves thermal conductivity. On the other hand, if the phosphor substrate 10 is too thick, the load on the rotating unit 30, which serves as a motor, increases, shortening its lifespan. Therefore, the thickness D21 of the main body 21 may be, for example, 0.2 mm to 50 mm, preferably 0.5 mm to 10 mm, and even more preferably 1 mm to 5 mm. The thicker the thickness D21 of the main body 21, the more easily the heat is dissipated from the phosphor substrate 10. On the other hand, the thinner the thickness D21 of the main body 21, the smaller the volume of the main body 21, and therefore the weight of the main body 21. Therefore, the rotating unit 30 can rotate the phosphor substrate 10 and the like with less energy. Therefore, the thickness D21 of the main body 21 should be within the above range.

[0070] Next, the plurality of first heat dissipation fins 22 of the metal member 20 will be described.

[0071] The multiple first heat dissipation fins 22 are protrusions that stand in the opposite direction from the main body 21 toward the phosphor substrate 10. In other words, the multiple first heat dissipation fins 22 are in contact with the main body 21 and are regions that protrude in the negative direction of the z-axis. FIG. 4 also shows thicknesses D22 of the multiple first heat dissipation fins 22. Note that the thicknesses D22 of the multiple first heat dissipation fins 22 are the same, but this is not limited to this. The thickness D22 is preferably thicker than the thickness D21 of the main body 21. For 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.

[0072] The thicker the thickness D22, the greater the heat dissipation effect. On the other hand, a thicker thickness D22 increases the weight, increasing the load on the rotating unit 30 (the motor). Furthermore, to maintain rigidity against rotation, the circumferential thickness of the first heat dissipation fins 22 must be increased. A thinner circumferential thickness of the first heat dissipation fins 22 reduces thermal conductivity from the main body 21, resulting in reduced heat dissipation performance. When the thickness D22 is 5 mm, the circumferential thickness of the first heat dissipation fins 22 is preferably in the range of 0.2 mm to 3 mm, and more preferably in the range of 0.4 mm to 2 mm. The circumferential thickness may vary; the above range is an average value excluding portions that are thicker due to factors such as screw fastening.

[0073] 1A, 1B, 2, and 3, twelve first heat dissipation fins 22 are provided. In plan view, the twelve first heat dissipation fins 22 are provided so as to extend radially. More specifically, the twelve first heat dissipation fins 22 are arranged so as to extend radially with respect to the axis B1. In other words, the twelve first heat dissipation fins 22 have a shape that extends radially from the center point C1 of the phosphor substrate 10. The twelve first heat dissipation fins 22 extend radially at equal intervals from the center point C1.

[0074] For example, when n first heat dissipating fins 22 are provided, "spreading at equal intervals" means that the angle formed between the extension direction of one first heat dissipating fin 22 and the extension direction of another first heat dissipating fin 22 adjacent to that first heat dissipating fin 22 is 360°÷n. In Fig. 2, the extension direction D1 of one first heat dissipating fin 22 and the extension direction D2 of another first heat dissipating fin 22 adjacent to that first heat dissipating fin 22 are indicated by dashed dotted lines. In this embodiment, the angle formed between the extension direction D1 of one first heat dissipating fin 22 of the twelve first heat dissipating fins 22 and the extension direction D2 of the other first heat dissipating fin 22 is 30°.

[0075] Although twelve first heat dissipation fins 22 are provided here, the present invention is not limited to this and there may be provided one or more first heat dissipation fins 22. The plurality of first heat dissipation fins 22 are not limited to the above and may be arranged in a matrix shape or a ring shape centered at a central point C1, for example.

[0076] 3, in bottom view, each of the plurality of first heat dissipation fins 22 includes a region that protrudes toward the center point C1. The protruding region of each of the plurality of first heat dissipation fins 22 protrudes inward from the inner circle of the main body 21 and is provided at a position that overlaps with the second through hole H2. In the present embodiment, all of the first through holes H1 and all of the second through holes H2 overlap, and therefore the protruding region of each of the plurality of first heat dissipation fins 22 is provided at a position that overlaps with the first through hole H1 and the second through hole H2.

[0077] 2 and 4, each of the multiple first heat dissipation fins 22 has a second side surface 221 at a position farthest from the axis B1. The second side surface 221 of each of the multiple first heat dissipation fins 22 is a slope that widens in the positive direction of the z-axis. The sloped second side surface 221 is not parallel to the z-axis. The second side surface 221 and the first side surface 213 of the main body 21 are connected flush with each other. The second side surface 221 and the first side surface 213 are parallel to each other at the connection point.

[0078] Providing the metal member 20 with the plurality of first heat dissipation fins 22 increases the surface area of ​​the metal member 20, making it easier for heat to be dissipated from the metal member 20. As a result, the heat generated in the phosphor substrate 10 by irradiation with the excitation light L1 is more easily dissipated from the phosphor substrate 10.

[0079] In this embodiment, the metal member 20 is made of Al. Al is a metal material that exhibits high thermal conductivity, and the thermal conductivity of Al is 237 W / m·K. The thermal conductivity of YAG, which constitutes the phosphor material, is 11.2 W / m·K. Therefore, by making the metal member 20 of Al, the heat dissipation properties of the phosphor substrate 10 can be further improved.

[0080] The metal member 20 may be made of a material other than Al or Cu, and may be made of, for example, one or more metal elements or alloys selected from Ni, Pd, Rh, Mo, W, and Cu. The thermal conductivities of the respective elements are as follows: Ni: 83 W / m·K, Pd: 73 W / m·K, Rh: 150 W / m·K, Mo: 135 W / m·K, W: 163 W / m·K, and Cu: 395 W / m·K. Therefore, by making the metal member 20 out of these metal materials, the heat dissipation properties of the phosphor substrate 10 can be further improved.

[0081] Next, the rotating part 30 will be described.

[0082] The rotating part 30 is located on the negative side of the z-axis relative to the metal member 20. In other words, 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, the rotating part 30 is provided at a position overlapping with the phosphor substrate 10 in plan view.

[0083] The rotating unit 30 is a member that rotates the phosphor substrate 10 and the metal member 20 around an axis B1 that extends in the thickness direction (z-axis direction) of the phosphor substrate 10, and is, for example, a motor. More specifically, in this embodiment, the rotating unit 30 rotates the phosphor substrate 10 and the metal member 20 around the axis B1 in the direction of arrow R shown in FIG. 1A. Note that the rotating unit 30 may rotate the phosphor substrate 10 and the metal member 20 in the direction opposite to the direction of arrow R shown in FIG. 1A. As shown in FIG. 1B, the axis B1 is an axis that passes through the center point C1 of the phosphor substrate 10.

[0084] The rotating part 30 has a disk part 31 and a rotating shaft whose axis is the axis B1. The disk part 31 is a flat member that has a circular shape in a plan view, 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.

[0085] As described above, the rotating portion 30 is joined to the metal member 20. More specifically, the disk portion 31 is joined to the plurality of first heat dissipation fins 22 of the metal member 20. As shown in FIG. 2 , the disk portion 31 is disposed so as to cover the negative side of the metal member 20 in the z-axis direction.

[0086] The disk portion 31 and the plurality of first heat dissipation fins 22 may be joined by bolts, screws, or the like. In the present embodiment, the disk portion 31 is joined to the plurality of first heat dissipation fins 22 via a joining layer. In this case, the joining layer may be the same as the joining layer that joins the metal member 20 and the phosphor substrate 10, for example.

[0087] As described above, the transmissive fluorescence-emitting module 1 according to this embodiment is equipped with a rotating section 30. This causes the phosphor substrate 10 and other components to rotate around axis B1, generating an airflow. This generated airflow cools the phosphor substrate 10. This makes it possible to suppress an increase in the temperature of the phosphor substrate 10 even when irradiated with excitation light L1, making it less likely for thermal quenching to occur and suppressing a decrease in fluorescence. In other words, the light utilization efficiency of the transmissive fluorescence-emitting module 1 can be improved.

[0088] As described above, in this embodiment, the first heat dissipation fins 22 of the metal member 20 are provided to extend radially. Therefore, when the phosphor substrate 10 is rotated by the rotating unit 30, a strong airflow with a higher flow rate is generated.

[0089] Furthermore, in the present embodiment, the first through-hole H1 and the second through-hole H2 are provided so as to overlap each other, so that when the phosphor substrate 10 or the like is rotated by the rotating unit 30, a stronger airflow with a higher flow rate is generated.

[0090] 1A, an example of the airflow is indicated by dashed arrows. Specifically, the airflow passes through the first through-hole H1, the second through-hole H2, and the gaps between the multiple first heat dissipation fins 22, in this order, toward the region A1 of the phosphor substrate 10. This allows the heat generated in the region A1 by irradiation with the excitation light L1 to be cooled by the airflow, thereby suppressing a rise in temperature of the phosphor substrate 10. In other words, by providing the first heat dissipation fins 22 of the metal member 20 so as to extend radially, the heat dissipation performance of the transmissive fluorescence light-emitting module 1 can be further improved. Furthermore, by providing the first through-hole H1 and the second through-hole H2 so as to overlap, a stronger airflow with a higher flow rate is generated. This further suppresses a rise in temperature of the phosphor substrate 10.

[0091] As described above, each of the first heat dissipation fins 22 includes a region that protrudes toward the center point C1. This makes it easier for the airflow to pass through the first through-holes H1, the second through-holes H2, and between the first heat dissipation fins 22. This generates an airflow with a higher flow rate, further suppressing the rise in temperature of the phosphor substrate 10.

[0092] In this embodiment, the disk portion 31 is disposed so as to cover the metal member 20. Therefore, the airflow generated when the phosphor substrate 10 or the like is rotated by the rotating portion 30 is more likely to flow toward the region A1, and the rise in temperature of the phosphor substrate 10 is further suppressed.

[0093] Furthermore, in this embodiment, a plurality of first heat dissipation fins 22 are provided between the main body 21 and the disk 31. In this case, a gap is provided between one first heat dissipation fin 22 and another first heat dissipation fin 22 adjacent to that one first heat dissipation fin 22. In other words, the provision of this gap reduces the weight of the metal member 20. Therefore, the rotating unit 30 can rotate the phosphor substrate 10 and the metal member 20 with less energy.

[0094] [Projector configuration] The transmissive fluorescence emission module 1 configured as above is used in a projector 500 shown in Fig. 5. Fig. 5 is a perspective view showing the appearance of projector 500 according to this embodiment. Fig. 6 is a schematic diagram showing transmissive fluorescence emission module 1 in projector 500 according to this embodiment. The configuration of projector 500 according to this embodiment will be described below with reference to Fig. 6.

[0095] 6, projector 500 according to this embodiment includes a transmissive fluorescence emission module 1. 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).

[0096] The housing 300 is a metal case that houses the phosphor substrate 10, the metal member 20, the rotating unit 30, the first optical element 301, the second optical element 302, and the fourth optical element 304. The housing 300 houses a portion of each of the two light emitting units 200 and a portion 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 unit 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 less likely to be contaminated by dust and dirt.

[0097] 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. Furthermore, if the projector 500 needs to be made smaller, it is necessary 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.

[0098] 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 units 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 disposed on the third main surface 11 side of the phosphor substrate 10. Also, as shown in FIG. 6, the excitation light L1 is condensed by the fourth optical element 304, so that the excitation light L1 is also incident on the phosphor substrate 10 from an oblique direction (i.e., a direction different from perpendicular to the third main surface 11).

[0099] 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 the image. Specifically, the display element is a transmissive liquid crystal panel. Alternatively, for example, the display element may be a reflective liquid crystal panel or a DLP (Digital Light Processing) having a DMD.

[0100] Next, the behavior of light in FIG. 6 will be described.

[0101] The excitation light L1 emitted by the light emitting unit 200 is incident on the region A1 of the phosphor substrate 10 in the transmissive fluorescence light-emitting module 1. A portion of the incident excitation light L1 is wavelength-converted by the phosphor material contained in the region A1 and passes through the phosphor substrate 10 as fluorescence. The other portion of the incident excitation light L1 passes through the phosphor substrate 10 without being wavelength-converted by the phosphor material contained in the region A1. The transmitted light L2 that passes through the phosphor substrate 10 is a composite light containing yellow fluorescence and wavelength-unconverted blue excitation light L1, and is white light. The transmitted light L2 is then emitted from the phosphor substrate 10. In other words, as described above, in this embodiment, the phosphor substrate 10 is used as a light-transmitting phosphor wheel.

[0102] Furthermore, as described above, since the shape of the region A1 is annular, the excitation light L1 is more likely to be incident on the region A1 when the phosphor substrate 10 or the like is rotated by the rotating unit 30. This makes it easier to use the phosphor substrate 10 as a phosphor wheel.

[0103] The transmitted light L2 emitted from the phosphor substrate 10 is collected 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 have to collect 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. It is only necessary that the radiation angle of the transmitted light L2 emitted from the first optical element 301, the second optical element 302, and the third optical element 303 is a radiation angle that allows efficient light transmission in the projector 500 and lighting device in which the transmissive fluorescence light-emitting module 1 is used.

[0104] 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). Light for an image generated by the display element becomes projection light that is enlarged and projected onto a screen. In other words, the transmitted light L2 is light that is used as projection light output by the projector 500. Note that an optical element (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.

[0105] In this embodiment, the transmissive fluorescence-emitting module 1 has a light-emitting section 200 that emits excitation light L1 that is incident on region A1. Region A1 is a region of the phosphor substrate 10 that does not overlap with the metal member 20. This makes it difficult for light loss, such as reflection of the excitation light L1 by the metal member 20, to occur. This allows the excitation light L1 to easily enter the phosphor substrate 10 and generate fluorescence, which is wavelength-converted light.

[0106] In this embodiment, the shape of the main body 21 is circular in plan view. The first main surface 211 and the second main surface 212 are located back to back, and 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 truncated cone. As described above, the excitation light L1 is incident on the region A1 of the phosphor substrate 10 from an oblique direction. Therefore, when the main body 21 has the above configuration, the excitation light L1 is less likely to be blocked by the metal member 20. In other words, it is possible to suppress light loss of the excitation light L1 due to blocking by the metal member 20. Therefore, the excitation light L1 is more likely to reach the region A1 of the phosphor substrate 10. As a result, a transmissive fluorescence-emitting module 1 with higher light utilization efficiency is realized.

[0107] Furthermore, in this embodiment, the projector 500 includes the transmissive fluorescent light-emitting module 1 that has high light utilization efficiency, thereby realizing the projector 500 with high light utilization efficiency.

[0108] The internal space of the housing 300 is a closed space to prevent contamination by dust and dirt, and therefore heat tends to build up. In the present embodiment, a first through-hole H1 and a second through-hole H2 are provided. Therefore, the airflow generated when the phosphor substrate 10 and other components are rotated by the rotating unit 30 flows from the third main surface 11 side to the fourth main surface 12 side of the phosphor substrate 10. As a result, the airflow circulates throughout the internal space of the housing 300, and heat generated in the phosphor substrate 10 due to irradiation with the excitation light L1 is more likely to move from the housing 300 to the outside. This makes it easier for the heat to be dissipated from the phosphor substrate 10.

[0109] Next, the housing 300 will be described in more detail.

[0110] Fig. 7 is a perspective view showing housing 300 according to this embodiment. As shown in Fig. 7, housing 300 has nine components. The nine components are a front surface member 311, a first left side surface member 312, a second left side surface member 313, a first right side surface member 314, a second right side surface member 315, a first bottom surface member 316, a second bottom surface member 317, a top surface member 318, and a back surface member 319. Housing 300 also has connecting members (screws, etc.) for connecting the nine components to one another.

[0111] Each of the nine components is formed by, for example, processing a metal plate such as a steel plate. In other words, each of the nine components is formed by cutting or bending a metal plate. Housing 300 is a case in which these nine components are combined. Because each of the nine components of housing 300 has a sheet metal structure, it is possible to make it lighter than, for example, a housing with a die-cast structure.

[0112] [Manufacturing method] Here, a method for manufacturing the phosphor substrate 10 will be briefly described.

[0113] The phosphor material contained in the phosphor substrate 10 is (Y 0.999 Ce 0.001 )3AlO 12 The phosphor material is a material composed of a crystalline phase represented by the formula: 3+ It is composed of activated phosphor.

[0114] The following three types of compound powders were used as raw materials to manufacture the phosphor substrate 10. 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.

[0115] First, a compound with a stoichiometric composition (Y 0.999 Ce 0.001 )3AlO 12The raw materials were weighed so that the weight of the raw materials was 100g. Next, the weighed raw materials and alumina balls (diameter 10mm) were placed in a plastic pot. The amount of alumina balls was such that they filled about 1 / 3 of the volume of the plastic pot. Then, pure water was placed in the plastic pot, and the raw materials and pure water were mixed using a pot rotating device (BALL MILL ANZ-51S, manufactured by Nitto Chemical Co., Ltd.). This mixing was carried out for 12 hours. In this way, a slurry-like mixed raw material was obtained.

[0116] The slurry-like mixed raw material was dried using a dryer. Specifically, a Naflon sheet was laid to cover the inner wall of a metal tray, and the mixed raw material was poured above the Naflon sheet. The metal tray, Naflon sheet, and mixed raw material were treated and dried for 8 hours in a dryer set at 150°C. The dried mixed raw material was then collected and granulated using a spray dryer. An acrylic binder was used as the adhesive (binder) during granulation.

[0117] The granulated mixed raw material was pre-molded into a cylindrical shape using an electric hydraulic press (EMP-5, manufactured by Riken Seiki Co., Ltd.) and a cylindrical mold. The pressure during molding was 5 MPa. Next, the pre-molded molded body was finally molded using a cold isostatic pressing device. The pressure during final molding was 300 MPa. The molded body after final molding was subjected to a heat treatment (binder removal treatment) in order to remove the adhesive (binder) used during granulation. The temperature of the heat treatment was 500°C. The heat treatment time was 10 hours.

[0118] The molded body after the heat treatment was sintered using a tubular atmosphere furnace. The sintering temperature was 1675°C. The sintering time was 4 hours. The sintering atmosphere was a mixed gas atmosphere of nitrogen and hydrogen.

[0119] The cylindrical fired product after firing was sliced ​​using a multi-wire saw, and the thickness of the sliced ​​cylindrical fired product was set to about 700 μm.

[0120] The sliced ​​fired product was polished using a polishing device to adjust the thickness of the fired product. By performing this adjustment, the fired product becomes the phosphor substrate 10.

[0121] [Temperature of phosphor substrate] Here, the temperature of the phosphor substrate 10 in the transmissive fluorescence emitting module 1 according to the present embodiment will be described using a transmissive fluorescence emitting module according to a study example. First, the transmissive fluorescence emitting module according to the study example will be described.

[0122] Fig. 8 is a plan view of the phosphor substrate 10, metal member 20x, and rotating section 30 included in the transmissive fluorescence emission module according to the study example. Fig. 9 is a plan view of the phosphor substrate 10, metal member 20, and rotating section 30 according to the present embodiment. Fig. 10 is a perspective view of the phosphor substrate 10, metal member 20x, and rotating section 30 included in the transmissive fluorescence emission module according to the study example. Fig. 11 is a perspective view of the phosphor substrate 10, metal member 20, and rotating section 30 according to the present embodiment.

[0123] 8 and 10, the transmissive fluorescence-emitting module according to the study example is a module including a phosphor substrate 10, a metal member 20x, and a rotating section 30. The transmissive fluorescence-emitting module according to the study example also includes two light-emitting sections 200 (not shown). In the transmissive fluorescence-emitting module according to the study example, only the shape of the metal member 20x differs from the transmissive fluorescence-emitting module 1 according to the present embodiment.

[0124] Here, the metal member 20x will be described.

[0125] The metal member 20x has the same configuration as the metal member 20 except for its shape. The metal member 20x is a flat plate-shaped member that is laminated on the phosphor substrate 10. More specifically, as shown in Figs. 8 and 10, the metal member 20x is cylindrical.

[0126] 8, 9, 10, and 11, the outer diameter of the metal member 20 (here, the outer diameter of the main body 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.

[0127] The metal member 20x has an outer diameter (diameter) of 28 mm. Also, 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.

[0128] 9 also shows the radius D31 of the main body 21. As described above, the radius D31 of the main body 21 is 17 mm.

[0129] In addition, when viewed from above, 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 Fig. 8 and Fig. 9, the region A1x and the region A1 correspond to the region between the two circles indicated by the dashed dotted lines.

[0130] In the present embodiment, the main body 21 and the region A1 are adjacent to each other when the phosphor substrate 10 is viewed from above. Here, the inner circle of the annular region A1 is in contact with the main body 21 (more specifically, the first main surface 211).

[0131] Similarly, in the studied example, the metal member 20x and the region A1 are adjacent to each other in a plan view of the phosphor substrate 10. The inner circle of the annular region A1x is in contact with the metal member 20x.

[0132] Next, 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 20x are rotated by the rotating unit 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 of 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.

[0133] 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. Both the measurement line M1 and the measurement line M2 are virtual straight lines parallel to the x-axis. In FIG. 12, the position at a distance of 0 mm corresponds to the center point C1 in FIGS. 8 and 9.

[0134] 12, in the study example, the temperature at the distance of 18 mm, which is the irradiation center position of the excitation light L1 (i.e., the position away from the distance of 0 mm by the irradiation center position distance D32), is the highest compared to other positions. Also, in the present embodiment, a similar tendency is shown.

[0135] However, when comparing the study example and this embodiment, the temperature in the center position of irradiation with the excitation light L1 in this embodiment is lower than the temperature in the study example.

[0136] As described above, the radius D31 of the main body 21 is larger than the radius D31x of the metal member 20x. In other words, the main body 21 is located closer to the irradiation center position of the excitation light L1 than the metal member 20x. Therefore, even if heat is generated in the phosphor substrate 10 due to irradiation with the excitation light L1, the heat is more likely to transfer from the phosphor substrate 10 to the main body 21 (i.e., the metal member 20). Therefore, in this embodiment, the heat dissipation properties of the phosphor substrate 10 can be further improved.

[0137] To summarize the above, in this embodiment, when the phosphor substrate 10 is viewed in a plan view, the main body portion 21 and the region A1 are adjacent to each other. Furthermore, 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.

[0138] This allows the heat generated by irradiation with the excitation light L1 to be easily transferred from the phosphor substrate 10 to the main body portion 21 (that is, the metal member 20), thereby further improving the heat dissipation properties of the phosphor substrate 10.

[0139] (First Modification of First Embodiment) Next, a transmissive fluorescence emitting module 1a according to Modification 1 of Embodiment 1 will be described with reference to Fig. 13A and Fig. 13B. Fig. 13A is a perspective view of the transmissive fluorescence emitting module 1a according to this modification. Fig. 13B is an exploded perspective view of the transmissive fluorescence emitting module 1a according to this modification.

[0140] The transmissive fluorescence-emitting module 1a according to this modification is a module including a phosphor substrate 10, a metal member 20a, a rotating section 30, and two light-emitting sections 200. For simplicity, only one light-emitting section 200 is shown in FIGS. 13A and 13B.

[0141] That is, the transmissive fluorescence emitting module 1a according to this modification is different from the transmissive fluorescence emitting module 1 according to the first embodiment in that it includes a metal member 20a instead of the metal member 20.

[0142] Here, the metal member 20a will be described. Except for the shape, the metal member 20a has the same configuration as the metal member 20. The metal member 20a has a main body portion 21a and a plurality of first heat dissipation fins 22a.

[0143] The main body portion 21a is a flat plate-shaped member that is provided so as to be stacked on the phosphor substrate 10.

[0144] Moreover, the shape of the main body 21a is circular in plan view. Furthermore, since the second through-hole H2 is provided in the main body 21a, the shape of the main body 21a is annular.

[0145] The main body 21 also has a first side surface portion 213a. As shown in Fig. 13A, the first side surface portion 213a stands upright in the vertical direction from the phosphor substrate 10, that is, extends in a direction parallel to the z-axis.

[0146] Next, the multiple first heat dissipation fins 22a of the metal member 20a will be described. The multiple first heat dissipation fins 22 are protrusions that stand in the direction opposite to the direction from the main body 21 toward the phosphor substrate 10.

[0147] 13A and 13B, twelve first heat dissipation fins 22a are provided here. In plan view, the twelve first heat dissipation fins 22a are provided so as to extend radially.

[0148] Each of the first heat dissipation fins 22a has a second side surface 211a at a position farthest from the axis B1. Like the first side surface 213a, the second side surface 211a of each of the first heat dissipation fins 22a extends in a direction parallel to the z-axis. The second side surface 211a and the first side surface 213a of the main body 21a are connected flush with each other. The second side surface 211a and the first side surface 213a are parallel to each other at the connection point.

[0149] In addition, in plan view, the phosphor substrate 10 according to the first modification 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 lines.

[0150] Thus, the transmissive fluorescence-emitting module 1a includes the phosphor substrate 10, the metal member 20a, the rotating section 30, and the two light-emitting sections 200. This realizes a transmissive fluorescence-emitting module 1a that can improve the light utilization efficiency, similar to the transmissive fluorescence-emitting module 1 according to the first embodiment.

[0151] (Modification 2 of Embodiment 1) Next, a transmissive fluorescence emitting module according to Modification 2 of Embodiment 1 will be described with reference to FIG.

[0152] 14 is a perspective view of a transmissive fluorescence emitting module according to Modification 2 of this embodiment. Note that the light emitting section 200 is omitted in FIG.

[0153] The transmissive fluorescence emission module according to this modification differs from the transmissive fluorescence emission module 1a according to the first modification in that it includes a cover 40 in addition to the components included in the transmissive fluorescence emission module 1a according to the first modification.

[0154] The cover 40 is a member made of resin or metal and includes a cover main body 41 and a flow path 42. The cover 40 is not rotated by the rotating part 30.

[0155] The cover main body 41 is a member that covers the phosphor substrate 10 and the metal member 20a. In this modification, a portion of the rotating unit 30 is exposed from a circular hole provided on the negative side of the z-axis of the cover main body 41. In other words, the cover main body 41 covers the other portions of the rotating unit 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 that is generated when the phosphor substrate 10 and the metal member 20a are rotated by the rotating unit 30.

[0156] The flow path portion 42 is a member connected to the cover main body portion 41. In a plan view, the flow path portion 42 is provided at a position overlapping with the area A2 onto which the excitation light L1 is incident. Furthermore, the above-mentioned controlled airflow flows through the flow path portion 42.

[0157] With the cover 40 having the above configuration, the airflow generated when the phosphor substrate 10 and other components are rotated by the rotating unit 30 is directed toward region A2. More specifically, the airflow passes through the negative z-axis side of region A2. An example of the airflow is indicated by the dashed-dotted arrow in FIG. 14 . The generated airflow cools the phosphor substrate 10. In other words, thermal quenching is less likely to occur and the decrease in fluorescence is suppressed, thereby further improving the light utilization efficiency of the transmissive fluorescence-emitting module according to this modified example.

[0158] (Third Modification of First Embodiment) Next, a transmissive fluorescence emitting module according to a third modification of the first embodiment will be described with reference to FIG.

[0159] Fig. 15 is a bottom view of the phosphor substrate 10 and the metal member 20b according to Modification 3 of the present embodiment. The rotating unit 30 and the light emitting unit 200 are omitted from Fig. 15. In Fig. 15, the area A3 of the phosphor substrate 10 according to Modification 3 corresponds to the area between the two circles indicated by the dashed dotted lines.

[0160] In this modification, the shape of the plurality of first heat dissipation fins 22b is different from the shape of the plurality of first heat dissipation fins 22 shown in the above embodiment. The plurality of first heat dissipation fins 22b have a curved arc shape when viewed from below. In other words, the plurality of first heat dissipation fins 22b have a spiral shape. Because the plurality of first heat dissipation fins 22b have such a shape, a strong airflow with a higher flow rate is generated when the phosphor substrate 10 or the like is rotated by the rotating unit 30.

[0161] The transmissive fluorescence-emitting module 1 according to this embodiment only needs to include a phosphor substrate 10, a metal member 20, and a rotating part 30. When the phosphor substrate 10 is viewed from above, it only needs to have a circular ring-shaped area A1 that does not overlap with the metal member 20.

[0162] The provision of the metal member 20 facilitates heat dissipation from the phosphor substrate 10. This makes it difficult for the thermal quenching phenomenon to occur, thereby suppressing the decrease in fluorescence.

[0163] Moreover, the transmissive fluorescence-emitting module 1 does not include any components for supporting the phosphor substrate 10. Therefore, there is no optical loss of the excitation light L1 as described above, and 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.

[0164] Furthermore, by providing the rotating unit 30, the phosphor substrate 10 and other components rotate around the axis B1, generating an air current. This generated air current cools the phosphor substrate 10. This makes it possible to suppress an increase in the temperature of the phosphor substrate 10 even when irradiated with excitation light L1, making it less likely for thermal quenching to occur and suppressing a decrease in fluorescence.

[0165] In summary, in the transmissive fluorescence emitting module 1, the temperature quenching phenomenon is unlikely to occur and there is no optical loss of the excitation light L1, so that the light utilization efficiency can be improved.

[0166] (Embodiment 2) 1A and 1B, a transmissive fluorescence-emitting module 1 has been described in which a phosphor substrate 10 provided with a first through-hole H1, a metal member provided with a second through-hole H2, and a rotating unit 30 are connected and assembled. In this transmissive fluorescence-emitting module 1, the first through-hole H1 and the second through-hole H2 are assembled to overlap, and an airflow generated when the phosphor substrate 10 and other components are rotated by the rotating unit 30 flows from the third main surface 11 side to the fourth main surface 12 side of the phosphor substrate 10. In other words, heat generated in the phosphor substrate 10 due to irradiation with excitation light L1 is cooled by passing the airflow generated when the phosphor substrate 10 and other components are rotated by the rotating unit 30 through the first through-hole H1 and the second through-hole H2 (by causing air to flow).

[0167] However, depending on the type of motor used in the rotating part 30, the second through hole H2 of the metal member 20 may fit into the motor shaft of the rotating part 30, and the second through hole H2 may not provide a sufficient gap for air to flow, resulting in the cooling effect not being achieved.

[0168] Therefore, in the second embodiment, a transmissive fluorescence light-emitting module, i.e., a phosphor wheel 1B, that can provide a cooling effect even when the through-hole provided in the center of the metal member cannot provide a cooling effect will be described. The following will mainly describe the differences from the metal member 20 described in the first embodiment.

[0169] [Phosphor Wheel 1B] FIG. 16 is a perspective view of a phosphor wheel 1B according to the second embodiment.

[0170] The phosphor wheel 1B according to the second embodiment is a transmissive phosphor wheel, and similar to the first embodiment, is used in light emitting devices such as projectors and lighting devices.

[0171] As shown in Fig. 16, the phosphor wheel 1B includes a phosphor substrate 10B made of a phosphor material, a metal member 20B, and a rotating part 30B. Note that the same elements as those in Figs. 1A and 1B are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0172] [Phosphor substrate 10B] Fig. 17 is a front view of the phosphor substrate 10B according to Embodiment 2. Fig. 18 is a side view of the phosphor substrate 10B shown in Fig. 17.

[0173] The phosphor substrate 10B is a substrate made of a phosphor material. The phosphor substrate 10B has a circular ring-shaped region that does not overlap with the metal member 20B in a plan view. As shown in Fig. 17, the phosphor substrate 10B has a circular ring-shaped region A11 having an inner diameter R1 and an outer diameter R2 that are approximately equal in distance from a center point C1, and a first through-hole 101B that penetrates the phosphor substrate 10 in the thickness direction (z-axis direction) of the phosphor substrate 10.

[0174] 1A and 1B, the phosphor substrate 10B has a larger inner diameter R1, and a portion of a metal member 20B (described later) is fitted into the first through-hole 101B. As will be described in detail later, on the metal member 20B side, a portion of the metal member 20B is joined with an adhesive or the like to a few millimeters inside the annular region A11. On the side opposite the metal member 20B, a portion of the metal member is fitted into the inner periphery of the annular region A11. In this way, the region excluding a few millimeters inside the annular region A11 forms an annular shape that does not overlap with the metal member 20B in plan view.

[0175] The outer diameter R2 of the phosphor substrate 10B is, for example, 40 mm or more and 50 mm or less, but is not limited to this and may be 35 mm or more and 70 mm or less, or 30 mm or more and 90 mm or less.

[0176] Furthermore, the inner diameter R1 of the phosphor substrate 10B is smaller than the outer diameter R2 of the phosphor substrate 10B, and is, for example, 30 mm or more and 40 mm or less, but is not limited to this and may be 25 mm or more and 60 mm or less, or 20 mm or more and 80 mm or less.

[0177] 18 is, for example, about 0.2 mm, but is not limited to this and may be 0.1 mm or more and 0.3 mm or less, or 0.08 mm or more and 0.5 mm or less. The outer diameter R2, inner diameter R1, and thickness t1 of phosphor substrate 10B may be appropriately determined so that phosphor wheel 1B fits into the housing of a product, such as a projector, to which 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 therefore description thereof will be omitted.

[0179] [Metal member 20B] Fig. 19 is a perspective view of the metal member 20B according to embodiment 2 as viewed from the negative side of the z axis. Fig. 20 is a perspective view of the metal member 20B according to embodiment 2 as viewed from the positive side of the z axis. Fig. 21 is an enlarged side view of a portion of the metal member 20B in Fig. 20. Fig. 21 is an enlarged schematic view of the side surface of the metal member 20B in region L shown in Fig. 20.

[0180] The metal member 20B shown in FIGS. 19 and 20 differs from the metal member 20 shown in FIGS. 1A and 1B mainly in that a plurality of openings 206 are further formed therein.

[0181] The metal member 20B is disposed and bonded to the third main surface 11 of the phosphor substrate 10B. The metal member 20B includes a main body 201, a plurality of first heat dissipation fins 202, second through holes 205, and a plurality of openings 206. In this embodiment, the metal member 20B is also located on the negative side of the z-axis relative to the phosphor substrate 10B, and is bonded to the third main surface 11 (not shown). Note that the material of the metal member 20B is the same as in the first embodiment, and therefore a description thereof will be omitted.

[0182] <Main body 201> The main body 201 is a flat plate-shaped member that fits into the phosphor substrate 10B. The main body 201 is circular. The outer diameter of the main body 201 is smaller than that of the phosphor substrate 10B but larger than the inner diameter of the phosphor substrate 10B. The outer diameter of the main body 201 is, for example, 34 mm, but is not limited to this, and may be 17 mm to 48 mm. The maximum outer diameter of the main body 201 may be equal to or smaller than a value that effectively irradiates the annular region A11 of the phosphor substrate 10B with a laser light source having a diameter of, for example, approximately 1 mm. The minimum outer diameter may be determined appropriately taking into account the rotor shaft diameter of the motor used in the rotating unit 30B and the minimum size at which the opening (described later) functions effectively. The thickness of the main body 201 is, for example, approximately 3 mm, but is not limited to this, and the upper limit may be determined appropriately so that the load applied to the motor used in the rotating unit 30B during rotation does not exceed the tolerance of the motor.

[0183] In this embodiment, as shown in FIG. 20 , the main body 201 has a step region 201a and a mating region 201b on the negative side of the z-axis. As shown in FIG. 21 , the step region 201a is recessed by t2 mm in the z-axis direction relative to the mating region 201b. An adhesive is applied to the step region 201a to bond the metal member 20B to the phosphor substrate 10B. As described in the first embodiment, the adhesive may be, for example, a silicone resin to mitigate the difference in thermal expansion coefficients. However, other epoxy resins or highly thermally conductive adhesives containing nano Ag or nano Cu may also be used. Alternatively, the step region 201a of the metal member 20B may be directly in contact with the third main surface 11 of the phosphor substrate 10 without using an adhesive. In this case, the metal member 20B may be configured to sandwich the phosphor substrate 10B with another metal member (not shown) different from the metal member 20B. For example, by joining a portion of the fitting region 201b of the metal member 20B to a metal member (not shown), the phosphor substrate 10B can be sandwiched between the step region 201a and a portion of the outer peripheral region of the metal member (not shown). The recess t2 of the step region 201a is, for example, about 0.3 mm, but is not limited to this. The recess t2 only needs to allow the surface of the fitting region 201b to protrude beyond the phosphor substrate 10B in the z-axis direction, and can be determined appropriately depending on the thickness of the phosphor substrate 10B.

[0184] In this way, the step region 201a of the main body 201 is joined to the region near the inner peripheral edge of the annular region A11 with an adhesive material, and the surface of the engagement region 201b protrudes from the phosphor substrate 10B in the z-axis direction, so that the metal member 20B engages with the phosphor substrate 10B.

[0185] <First heat dissipation fin 202> When the metal member 20B is viewed from above, the multiple first heat dissipation fins 202 are provided radially from the central axis (center point C1) in an area excluding an area including the central axis of the metal member 20B. The central axis of the metal member 20B is the same axis as the axis B1. In this embodiment, the multiple first heat dissipation fins 202 extend radially at equal intervals from the center point C1 in an area excluding the second through-holes 205 on the negative side of the z axis of the metal member 20B.

[0186] The first heat dissipation fins 202 are provided on the metal member 20B so as to protrude in the direction opposite to the third main surface 11 (not shown). That is, the first heat dissipation fins 202 are provided upright so as to protrude in the direction (the negative direction of the z-axis) from one of the two main surfaces of the phosphor substrate 10B (the third main surface 11) to which the metal member 20B is bonded) toward the other main surface (the fourth main surface 12). The first heat dissipation fins 202 each have the same thickness. In this embodiment, as shown in FIG. 19 and other figures, an example is shown in which each of the first heat dissipation fins 202 has two widths. In the example shown in FIG. 19, the first heat dissipation fin 202b is secured to the disk portion 31 of the rotating portion 30B with screws, and the width of the first heat dissipation fin 202a among the first heat dissipation fins 202 is narrower than the width of the first heat dissipation fin 202b. 19, the first heat dissipation fin 202b is provided to be wider than the first heat dissipation fin 202a because it is screwed to the disk portion 31 of the rotating part 30B. Note that even when the first heat dissipation fin 202b is screwed to the disk portion 31 of the rotating part 30B, the width of the first heat dissipation fin 202a and the width of the first heat dissipation fin 202b may be the same. Furthermore, the first heat dissipation fin 202b is not limited to being screwed to the disk portion 31 of the rotating part 30B, and may be joined to the disk portion 31 of the rotating part 30B with an adhesive. In this case, the width of the first heat dissipation fin 202a and the width of the first heat dissipation fin 202b may be the same.

[0187] The metal member 20B has a plurality of first heat dissipation fins 202, which increases the surface area of ​​the metal member 20B, thereby facilitating heat dissipation from the metal member 20B.

[0188] <Second through-hole 205> The second through-hole 205 is a hole that penetrates the metal member 20B in the thickness direction (z-axis direction) of the metal member 20B. In this embodiment, the shaft center that is the motor shaft of the rotating part 30B passes through the second through-hole 205 and is fitted into it.

[0189] <Aperture 206> When the metal member 20B is viewed in a plane, the openings 206 are provided in regions between the multiple first heat dissipation fins 202 in the metal member 20B. More specifically, when the metal member 20B is viewed in a plane, the openings 206 are provided in regions between the multiple first heat dissipation fins 202 in the metal member 20B, in a region excluding a circular region including the central axis of the metal member 20B and an outer ring region of the metal member 20B. In other words, as shown in FIG. 19 , for example, the openings 206 are provided in regions between the multiple first heat dissipation fins 202 in the metal member 20B, excluding the second through-holes 205 and the main body portion 201.

[0190] By having multiple openings 206, the metal member 20B can direct the airflow generated when the phosphor substrate 10B or the like is rotated by the rotating part 30B from the positive side of the z-axis (the third main surface 11 side) to the negative side of the z-axis (the fourth main surface 12 side) of the phosphor substrate 10B.

[0191] It is considered that the greater the proportion of opening 206 that metal member 20B occupies when metal member 20B is viewed in plan, the more easily heat generated in phosphor substrate 10B due to irradiation with excitation light L1 can be cooled. For this reason, the proportion of opening 206 can be maximized by narrowing the width of multiple first heat dissipation fins 202 and narrowing the annular area of ​​main body 201 within the allowable strength range of metal member 20B depending on the product to which phosphor wheel 1B is applied.

[0192] [Rotating part 30B] The rotating unit 30B has a disk portion 31 and a rotating shaft with an axis B1 as its axis. The rotating unit 30B rotates the phosphor substrate 10B and the metal member 20B around the axis B1 extending in the thickness direction of the phosphor substrate 10B as its center (central axis). The rotating unit 30B is provided at a position overlapping the phosphor substrate 10B in a plan view and is joined to the metal member 20B. The rotating unit 30B is, for example, an outer rotor type motor, but is not particularly limited thereto. The rotating unit 30B drives and rotates the phosphor substrate 10B and the metal member 20B under the control of an electronic circuit (not shown).

[0193] In this embodiment, the shaft center of the rotating part 30B, which is the motor shaft, is fitted into the second through-hole 205 of the metal member 20B.

[0194] [Effects, etc.] As described above, the phosphor wheel 1B according to this embodiment is a transmissive phosphor wheel. The phosphor wheel 1B includes a phosphor substrate 10B, which is a substrate made of a phosphor material, and a metal member 20B bonded to a third main surface 11 of the phosphor substrate 10B. The metal member 20B has a plurality of first heat dissipation fins 202 protruding in a direction opposite to the third main surface 11. The phosphor wheel 1B also includes a rotation unit 30B that rotates the phosphor substrate 10B and the metal member 20B around 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 viewed from above. When viewed from above, the phosphor wheel 1B also includes an opening 206 in a region between the plurality of first heat dissipation fins 202 in the metal member 20B.

[0195] Thus, in this embodiment, the metal member 20B has multiple openings 206, which allows the airflow generated when the phosphor substrate 10B and other components are rotated by the rotating unit 30B to be directed from the positive side of the z axis (the third main surface 11 side) to the negative side of the z axis (the fourth main surface 12 side) of the phosphor substrate 10B. Heat generated in the phosphor substrate 10B due to irradiation with the excitation light L1 is transferred to the metal member 20B bonded to the phosphor substrate 10B, i.e., the first heat dissipation fin 202 and the main body 201, and the metal member 20B is cooled by the airflow passing through the openings 206. In other words, heat from the phosphor substrate 10B is more easily dissipated, thereby suppressing a temperature increase in the phosphor substrate 10B due to irradiation with the excitation light L1. As a result, thermal quenching is less likely to occur, and therefore a decrease in fluorescence is suppressed.

[0196] In phosphor wheel 1B according to the present embodiment, when metal member 20B is viewed in a plan view, each of the plurality of openings is provided in a region between the plurality of first heat dissipation fins 202 in metal member 20B, in a region excluding a circular region including the central axis of metal member 20B and the outer ring region of metal member 20B. By providing the plurality of openings 206 in metal member 20B in this manner, it is possible to direct an airflow generated when phosphor substrate 10B and the like are rotated by rotating unit 30B from the positive side of the z axis (the third main surface 11 side) to the negative side of the z axis (the fourth main surface 12 side) of phosphor substrate 10B.

[0197] Furthermore, in phosphor wheel 1B according to the present embodiment, the multiple first heat dissipation fins 202 are provided radially from the central axis of metal member 20B in a region excluding the region including the central axis of metal member 20B when metal member 20B is viewed in plan view. This makes it possible to generate a strong airflow with a higher flow rate when phosphor substrate 10B and the like are rotated by rotating unit 30B, thereby further improving the heat dissipation performance of phosphor wheel 1B, i.e., the transmissive fluorescence light-emitting module.

[0198] Next, a description will be given of the results of verification conducted by fabricating an actual prototype of the phosphor wheel 1B according to the present embodiment configured as described above.

[0199] Fig. 22 is a diagram showing the verification results for a working prototype of phosphor wheel 1B according to embodiment 2. Fig. 22 shows the verification results of the temperature rise of the sintered phosphor (phosphor substrate 10B) of phosphor wheel 1B according to embodiment 2 when operated for a predetermined time. Note that Fig. 22 also shows, as comparative example 1, the verification results for a working prototype of transmissive fluorescence light-emitting module 1 according to embodiment 1.

[0200] Fig. 23A is a diagram showing a metal member 20 used in a working prototype according to Comparative Example 1. Fig. 23A shows a metal member 20 according to Embodiment 1 that does not have a plurality of openings 206, as a working prototype according to Comparative Example 1. Fig. 23B is a diagram showing a metal member 20B used in a working prototype according to Embodiment 2. Fig. 23B shows a metal member 20B according to the present embodiment that has a plurality of openings 206, as a working prototype according to the present embodiment.

[0201] 22, 23A, and 23B, it can be seen that the temperature rise of the sintered phosphor of the phosphor wheel 1B according to embodiment 2, i.e., the phosphor wheel 1B having the metal member 20B provided with a plurality of openings 206, is 171.7 [K]. On the other hand, it can be seen that the temperature rise of the sintered phosphor of the transmissive fluorescence light-emitting module 1 according to comparative example 1, i.e., the transmissive fluorescence light-emitting module 1 having the metal member 20 without the plurality of openings 206, is 179.3 [K]. From these results, it can be seen that by providing a plurality of openings 206 in the metal member 20B, the temperature rise of the sintered phosphor is suppressed.

[0202] Fig. 24 is a diagram showing another verification result for an actual prototype of phosphor wheel 1B according to embodiment 2. Fig. 24 shows the verification results of the temperature rise of the sintered phosphor of phosphor wheel 1B according to embodiment 2 and the temperature rise of the sintered phosphor of phosphor wheel 1B in Comparative Example 2 when the area of ​​opening 206 is drastically reduced to half.

[0203] From FIG. 24, in the phosphor wheel 1B according to the second embodiment, in the case of the comparative example 2, that is, when the area of ​​the plurality of openings 206 is halved, the temperature rise of the sintered phosphor is 176.0 [K]. In other words, when the area of ​​the plurality of openings 206 is drastically reduced to half as in the comparative example 2, it can be seen that the temperature rise is higher than the temperature rise (171.7 [K]) of the sintered phosphor of the phosphor wheel 1B according to the second embodiment, in which the area of ​​the plurality of openings 206 is large as shown in FIG. 23B. Note that even when the area of ​​the plurality of openings 206 is halved, it is lower than the temperature rise (179.0 [K]) of the sintered phosphor of the transmissive fluorescence light-emitting module 1 according to the first comparative example. This shows that the temperature rise of the sintered phosphor can be suppressed by providing the plurality of openings 206 with a sufficiently large area in the metal member 20B.

[0204] Next, the results of an analysis of the flow of fluid near the opening 206 provided in the metal member 20B according to the second embodiment will be described.

[0205] Fig. 25 is a diagram showing a cross section used in the analysis of metal member 20B according to embodiment 2. Fig. 26 is a diagram showing the analysis results of the fluid flow near opening 206 of metal member 20B according to embodiment 2. Fig. 26 shows a cross section of metal member 20B taken along line XI-XI in Fig. 25, and shows the state of the fluid flow near opening 206 in that cross section using streamlines.

[0206] The openings 206 are provided in the metal member 20B, excluding the second through-holes 205 and the main body 201, in a region between the multiple first heat dissipation fins 202. From the fluid flow diagram in FIG. 26, it can be seen that the openings 206 can direct the airflow generated when the phosphor substrate 10B and other components are rotated by the rotating unit 30B from the positive side of the z-axis to the negative side of the z-axis of the phosphor substrate 10B. Furthermore, from the fluid flow diagram in FIG. 26, it can be seen that convection occurs near the annular region of the first heat dissipation fins 202 and the main body 201. If the openings 206 were not provided in the metal member 20B, the airflow would not be directed from the positive side of the z-axis to the negative side of the z-axis of the phosphor substrate 10B, and thus the above-mentioned convection would not be promoted. Therefore, since the metal member 20B has a plurality of openings 206, air can reliably pass through the openings 206, generating an air flow near the annular region of the first heat dissipation fin 202 and the main body 201, thereby promoting convection near the first heat dissipation fin 202 and the main body 201. This allows the first heat dissipation fin 202 and the main body 201 to be cooled, thereby cooling the heat that is generated in the phosphor substrate 10B due to irradiation with the excitation light L1 and that is transferred to the first heat dissipation fin 202 and the main body 201. As a result, heat from the phosphor substrate 10B is more easily dissipated, i.e., the heat dissipation properties of the phosphor substrate 10B are thought to be improved, and therefore the rise in temperature of the phosphor substrate 10B due to irradiation with the excitation light L1 can be suppressed.

[0207] (Variation) In the second embodiment described above, the first heat dissipation fins 202 are arranged at equal intervals and extend radially, but this is not limiting. As shown in Fig. 27, the first heat dissipation fins 202D may be formed in a multi-blade fan shape.

[0208] Fig. 27 is a perspective view of a metal member 20B according to a modification of embodiment 2, viewed from the negative side of the z-axis. Fig. 28 is a diagram for explaining the conditions for the shape of the first heat dissipation fin 202D shown in Fig. 27. Note that the same elements as those in Fig. 19 and the like are given the same reference numerals, and detailed description thereof will be omitted.

[0209] 27 differs from the metal member 20B shown in Fig. 19 etc. in the shape of the plurality of first heat dissipation fins 202D, but is otherwise similar to the metal member 20B described in the second embodiment.

[0210] More specifically, when the metal member 20B is viewed from above, each of the multiple first heat dissipation fins 202D is provided in an arc shape that is concavely curved in the rotation direction of the metal member 20B in a region excluding a region including the central axis of the metal member 20B. In this embodiment, the multiple first heat dissipation fins 202D are provided in a multi-blade fan shape in a region excluding the second through-holes 205 on the negative side of the z axis of the metal member 20B. The shape of each of the multiple first heat dissipation fins 202D may be formed so that β shown in FIG. 28 is greater than 90 degrees with respect to the rotation direction ω, i.e., the angle β formed between an extension line of the first heat dissipation fin 202D and a tangent line to the metal member 20B is greater than 90 degrees.

[0211] Among the plurality of first heat dissipation fins 202D, the first heat dissipation fin 202D used for fastening to the disk portion 31 of the rotating portion 30B with screws may be provided so as to be wider than the other first heat dissipation fins 202D. Other aspects such as the direction in which the plurality of first heat dissipation fins 202D are erected are the same as those of the plurality of first heat dissipation fins 202 described above, and therefore will not be described again.

[0212] With this configuration, when the phosphor substrate 10B or the like is rotated by the rotating part 30B, a strong air current (air flow) with a higher flow rate can be generated, thereby further improving the heat dissipation properties of the phosphor wheel 1B, i.e., the transmissive fluorescent light-emitting module.

[0213] (Embodiment 3) In the third embodiment, a transmissive fluorescence light-emitting module, i.e., a phosphor wheel, will be described, which has improved heat dissipation compared to the second embodiment. The following description will focus on the differences from the metal member 20B described in the second embodiment.

[0214] The transmissive fluorescence light-emitting module, ie, the phosphor wheel, according to the present embodiment has the same configuration as the phosphor wheel 1B according to the second embodiment, except that it includes a metal member 20C instead of the metal member 20B.

[0215] That is, the phosphor wheel according to this embodiment includes a phosphor substrate 10B, a metal member 20C, and a rotating portion 30B. Note that the same elements as those in the first and second embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0216] [Metal member 20C] Fig. 29 is a perspective view of the metal member 20C according to the third embodiment as viewed from the negative side of the z axis. Fig. 30 is a perspective view of the metal member 20C according to the third embodiment as viewed from the positive side of the z axis.

[0217] The metal member 20C shown in Figures 29 and 30 differs from the metal member 20B shown in Figures 19 and 20 mainly in that it has a main body portion 201C instead of the main body portion 201, and that it also has a plurality of second heat dissipation fins 207.

[0218] The metal member 20C is bonded to the third main surface 11 of the phosphor substrate 10B. The metal member 20C includes a main body 201C, a plurality of first heat dissipation fins 202, a plurality of second heat dissipation fins 207, second through holes 205, and a plurality of openings 206. In this embodiment, the metal member 20C is also located on the negative side of the z-axis relative to the phosphor substrate 10B, and is bonded to the third main surface 11 (not shown). Note that the material of the metal member 20C is the same as in the first embodiment, and therefore a description thereof will be omitted.

[0219] <Main body 201C> Except for the size, main body 201C has the same configuration as main body 201 according to embodiment 2. The outer shape of main body 201C is larger than the outer shape of main body 201. Main body 201C is configured as follows.

[0220] The main body 201C is a flat-plate-shaped member and is fitted to the phosphor substrate 10B. The main body 201C has a circular shape, more specifically, an annular shape. The outer diameter of the main body 201C is smaller than that of the phosphor substrate 10B and larger than the inner diameter of the phosphor substrate 10B. The outer diameter of the main body 201C is, for example, 38 mm, but is not limited to this and may be 17 mm to 48 mm. The maximum outer diameter of the main body 201C may be equal to or smaller than a value at which a laser light source having a diameter of, for example, about 1 mm can effectively irradiate the annular region A11 of the phosphor substrate 10B. The minimum outer diameter of the main body 201C may be determined appropriately taking into account the rotor shaft diameter of the motor used in the rotating unit 30B and the minimum size at which the opening described below can effectively function. Thus, the outer shape of the main body 201C is larger than that of the main body 201. As shown in FIG. 29, when viewed from above (i.e., when viewing the metal member 20C in the positive direction of the z-axis), the main body 201C has an area A4 where multiple first heat dissipation fins 202 are not provided.

[0221] Region A4 has an annular shape in plan view, and region A4 corresponds to the region between the two circles indicated by the dashed dotted lines. That is, region A4 corresponds to the region between inner circumference 209, which is closer to center point C1, and outer circumference 210, which is farther from center point C1 than inner circumference 209, in plan view. The center of the annular shape that is region A4 overlaps with center point C1 of phosphor substrate 10B in plan view, and the centers of inner circumference 209 and outer circumference 210 also overlap with center point C1 in plan view.

[0222] Furthermore, the thickness of the main body 201C is, for example, about 3 mm, but is not limited to this, and the upper limit may be appropriately determined so that the load applied to the motor used in the rotating part 30B during rotation does not exceed the tolerance of the motor.

[0223] In this embodiment, as in the second embodiment, the main body portion 201C has a step region 201a and a fitting region 201b on the positive side of the z axis as shown in FIG.

[0224] The step region 201a of the main body portion 201C is joined with an adhesive member to an area near the inner peripheral edge of the annular region A11 of the phosphor substrate 10B, and the surface of the engagement region 201b protrudes from the phosphor substrate 10B in the z-axis direction, so that the metal member 20C engages with the phosphor substrate 10B.

[0225] <First heat dissipation fin 202> When the metal member 20C is viewed from above, the multiple first heat dissipation fins 202 are provided radially from the central axis (center point C1) in a region excluding a region including the central axis of the metal member 20C. In this embodiment, the multiple first heat dissipation fins 202 extend radially from the center point C1 in a region excluding the second through-holes 205 on the negative side of the z-axis of the metal member 20C so as to be equally spaced apart. That is, when viewed from above, each of the multiple first heat dissipation fins 202 extends in a direction from the central axis B1 (center point C1) toward the outer end of the main body 201C. The outer end of the main body 201C is the outer circumference of the circular (more specifically, annular) main body 201C. Note that, in this embodiment, the outer circumference of the circular main body 201C coincides with the outer circumference 210 of the region A4. Each of the first heat dissipation fins 202 extends toward the outer edge of the main body 201C, but does not reach the outer edge (i.e., the outer circumference 210) of the main body 201C. Each of the first heat dissipation fins 202 extends toward the outer edge of the main body 201C, and extends to the inner circumference 209 of the annular area A4.

[0226] Furthermore, the multiple first heat dissipation fins 202 are provided on the metal member 20C so as to protrude in the opposite direction from the third main surface 11 (not shown). In other words, the multiple first heat dissipation fins 202 are provided so as to protrude in the negative direction of the z-axis. The thickness t3 of each of the multiple first heat dissipation fins 202 is the same. FIG. 31 is a side view of the metal member 20C according to this embodiment. The thickness t3 refers to the height of the first heat dissipation fin 202 in the z-axis direction. The thickness t3 of each of the multiple first heat dissipation fins 202 may be different for each first heat dissipation fin 202.

[0227] In the present embodiment, similarly to the metal member 20B according to embodiment 2, each of the plurality of first heat dissipation fins 202 has two widths. In the plurality of first heat dissipation fins 202, the width of first heat dissipation fin 202a is set to be narrower than the width of first heat dissipation fin 202b.

[0228] The metal member 20C has a plurality of first heat dissipation fins 202, which increases the surface area of ​​the metal member 20C, thereby facilitating heat dissipation from the metal member 20C.

[0229] <Second heat dissipation fin 207> When the metal member 20C is viewed from above, the multiple second heat dissipation fins 207 are provided radially from the central axis (center point C1) in an area excluding an area including the central axis of the metal member 20C. In this embodiment, the multiple second heat dissipation fins 207 extend radially at equal intervals from the center point C1 in a area excluding the second through-holes 205 on the positive side of the z axis of the metal member 20C.

[0230] Furthermore, the second heat dissipation fins 207 are provided on the metal member 20C so as to protrude in the opposite direction to the protruding direction of the first heat dissipation fins 202. That is, the second heat dissipation fins 207 are provided upright so as to protrude in the positive direction of the z-axis. In other words, the second heat dissipation fins 207 are provided upright so as to protrude in the direction (positive direction of the z-axis) from the fourth main surface 12 of the two main surfaces of the phosphor substrate 10B toward the third main surface 11.

[0231] The thickness t4 of each of the multiple second heat dissipation fins 207 is the same. As shown in Fig. 31, the thickness t4 refers to the height of the second heat dissipation fin 207 in the z-axis direction. The thickness t4 of each of the multiple second heat dissipation fins 207 may be different for each second heat dissipation fin 207. The thickness t4 is thinner than the thickness t3, but is not limited to this, and may be thicker than the thickness t3.

[0232] Furthermore, one second heat dissipation fin 207 is provided at a position overlapping one first heat dissipation fin 202 in plan view. The same applies to the other multiple second heat dissipation fins 207 other than the one second heat dissipation fin 207. Here, each of the multiple second heat dissipation fins 207 is provided so as to overlap a respective one of the multiple first heat dissipation fins 202a in plan view. Note that three more second heat dissipation fins 207 may be provided so as to overlap a respective one of the three first heat dissipation fins 202a.

[0233] The plurality of second heat dissipating fins 207 shown in FIG. 30 each have the same width, which is the same as the width of the first heat dissipating fins 202a.

[0234] The metal member 20C further has a plurality of second heat dissipation fins 207, which increases the surface area of ​​the metal member 20C and promotes heat dissipation from the metal member 20C.

[0235] <Second through-hole 205> The second through-hole 205 is a hole that penetrates the metal member 20C in the thickness direction (z-axis direction) of the metal member 20C. In this embodiment, the shaft center that is the motor shaft of the rotating part 30B passes through the second through-hole 205 and is fitted into it.

[0236] <Aperture 206> The openings 206 are provided in regions between the multiple first heat dissipation fins 202 in the metal member 20C when viewed in a plane. It can also be said that the openings 206 are provided in regions between the multiple second heat dissipation fins 207 in the metal member 20C when viewed in a plane. More specifically, the openings 206 are provided in regions between the multiple first heat dissipation fins 202 and between the multiple second heat dissipation fins 207 in a region excluding a circular region including the central axis of the metal member 20C and an outer ring region of the metal member 20C when viewed in a plane. In other words, as shown in FIG. 30 , for example, the openings 206 are provided in regions between the multiple first heat dissipation fins 202 in the metal member 20C excluding the second through-holes 205 and the main body portion 201C. Similarly, the openings 206 are provided in the areas between the plurality of second heat dissipation fins 207 in the metal member 20C excluding the second through-holes 205 and the main body portion 201C.

[0237] [Effects, etc.] As described above, in this embodiment, the metal member 20C is provided with the plurality of second heat dissipation fins 207 so as to protrude in the opposite direction to the direction in which the plurality of first heat dissipation fins 202 protrude.

[0238] As a result, the metal member 20C has a plurality of second heat dissipation fins 207, which increases the surface area of ​​the metal member 20C and promotes heat dissipation from the metal member 20C. In other words, heat from the phosphor substrate 10B is more easily dissipated, which makes it possible to suppress a rise in the temperature of the phosphor substrate 10B due to irradiation with the excitation light L1. As a result, thermal quenching is less likely to occur, and therefore a decrease in fluorescence is suppressed.

[0239] (Other embodiments) While the phosphor wheel and the like according to the present invention have been described above based on the embodiments and modifications thereof, the present invention is not limited to these embodiments and modifications. As long as they do not deviate from the gist of the present invention, various modifications that a person skilled in the art would conceive of, or other forms constructed by combining some of the components of the embodiments and modifications, are also included within the scope of the present invention.

[0240] For example, the above-described embodiment and modified examples are merely examples, and it goes without saying that various modifications, additions, omissions, etc. are possible.

[0241] Furthermore, for example, the scope of the present disclosure also includes forms realized by any combination of the components and functions shown in the above-described embodiments and modifications. In addition, the present disclosure also includes forms obtained by applying various modifications to the above-described embodiments and modifications that would occur to a person skilled in the art, and forms realized by any combination of the components and functions in each embodiment within the scope of the present disclosure. Furthermore, for example, it is possible to combine the components described in the embodiments and modifications to create new embodiments.

[0242] Furthermore, the components shown in the accompanying drawings and detailed description may include not only essential components for solving the problem, but also components that are not essential for solving the problem in order to illustrate the above technology. Therefore, the fact that these non-essential components are shown in the accompanying drawings or detailed description should not be interpreted as indicating that these non-essential components are essential. [Explanation of symbols]

[0243] 1B Phosphor Wheel 10B Phosphor substrate 11 Third main surface 20B Metallic parts 201 Main body 30B Rotating part 202 First heat dissipation fin 206 Aperture 207 Second heat dissipation fin A11 Circular domain L1 excitation light

Claims

1. A transmissive phosphor wheel, a phosphor substrate which is a substrate made only of a phosphor material; a metal member bonded to a main surface of the phosphor substrate and provided with a plurality of first heat dissipation fins protruding in a direction opposite to the main surface; a rotating unit that rotates the phosphor substrate and the metal member around an axis extending in a thickness direction of the phosphor substrate, When the phosphor substrate is viewed from above, the phosphor substrate has a ring-shaped region that does not overlap with the metal member, When the metal member is viewed from above, an opening is provided in a region between the plurality of first heat dissipation fins in the metal member. Phosphor wheel.

2. When the metal member is viewed from above, the plurality of first heat dissipation fins are provided radially with respect to the central axis of the metal member in a region excluding a region including the central axis of the metal member. The phosphor wheel according to claim 1 .

3. When the metal member is viewed from above, each of the plurality of first heat dissipation fins is provided in an arc shape that is concavely curved in a rotation direction of the metal member in a region excluding a region including a central axis of the metal member. The phosphor wheel according to claim 1 .

4. The metal member is provided with a plurality of second heat dissipation fins that protrude in a direction opposite to a direction in which the plurality of first heat dissipation fins protrude. The phosphor wheel according to claim 1 .

5. No member supporting the phosphor substrate is provided. The phosphor wheel according to claim 1 .

6. the openings are provided in regions between the plurality of first heat dissipation fins in the metal member, in a region excluding a circular region including a central axis of the metal member and an outer ring region of the metal member, when the metal member is viewed in a plane; The phosphor wheel according to any one of claims 1 to 5.

7. A phosphor wheel according to claim 6, Light-emitting device.

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