Fluorescent light-emitting module and light-emitting device

Abstract

To provide a fluorescent light emitting module and a light emitting device that have high light utilization efficiency, and have high reliability.SOLUTION: A fluorescent light emitting module 1c comprises a phosphor board 10c that is a board made of a sintered phosphor comprising a phosphor material, and a rotating part 100 for rotating the phosphor board 10c around an axis A1 extending in a thickness direction of the phosphor board 10c.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a fluorescent light-emitting module and a light-emitting device using the same. [Background technology]

[0002] Fluorescence light-emitting modules that receive excitation light and emit fluorescence have been known in the past, and are used in light-emitting devices such as projectors.

[0003] As an example of a fluorescence-emitting module, Patent Document 1 discloses a light source device including a light-emitting unit that emits excitation light, a fluorescence-generating unit that is excited by the excitation light and generates fluorescence, and a phosphor substrate made of a plate-shaped glass member that supports the fluorescence-generating unit, etc. In this fluorescence-emitting module, excitation light is incident on the phosphor substrate from the atmosphere. Furthermore, the excitation light that has entered the phosphor substrate passes through the phosphor substrate and enters the fluorescence-generating unit, where fluorescence is generated. [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] In the above-described fluorescence-emitting module, due to the difference in refractive index between the atmosphere and the phosphor substrate, part of the excitation light incident on the phosphor substrate from the atmosphere is reflected toward the atmosphere. As a result, less excitation light is incident on the fluorescence generating unit than when part of the excitation light is not reflected, and therefore less fluorescence is generated in the fluorescence generating unit. Therefore, the above-described fluorescence-emitting module has the problem of low light utilization efficiency.

[0006] In the above-described fluorescence-emitting module, the fluorescence generating section on the phosphor substrate is composed of a phosphor material and a transparent resin. In the fluorescence generating section, the phosphor material generates the most heat when irradiated with excitation light. The heat generated in the phosphor material is thermally conducted and dissipated through the transparent resin. However, because the transparent resin has low thermal conductivity (i.e., high thermal resistance), it is difficult to efficiently dissipate the heat generated in the phosphor material. This heat causes a phenomenon in which the amount of generated fluorescence decreases (the so-called thermal quenching phenomenon), resulting in a significant change in the chromaticity of the light output from the fluorescence-emitting module. Furthermore, because the linear expansion coefficient of the transparent resin is significantly different from that of the fluorescence generating section and the phosphor substrate, the heat easily causes the fluorescence generating section to peel off from the phosphor substrate. This chromaticity change and peeling, among other issues, pose a problem of low reliability for the fluorescence-emitting module.

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a fluorescent light-emitting module and a light-emitting device that are highly efficient in light utilization and highly reliable. [Means for solving the problem]

[0008] A fluorescence-emitting module according to one aspect of the present invention includes a phosphor substrate, which is a substrate made of a sintered phosphor having a phosphor material, and a rotating unit that rotates the phosphor substrate around an axis extending in the thickness direction of the phosphor substrate.

[0009] Furthermore, a fluorescent light-emitting module according to an aspect of the present invention includes a phosphor substrate, which is a substrate made of a sintered phosphor having a phosphor material and a high thermal conductivity material having a thermal conductivity of 100 W / m·K or more and 300 W / m·K or less.

[0010] A light emitting device according to an aspect of the present invention includes the above-described fluorescence light emitting module. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a fluorescent light-emitting module and a light-emitting device that have high light utilization efficiency and high reliability. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a perspective view of a fluorescence light-emitting module according to a second embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing a cut surface of a part of the fluorescent light-emitting module taken along line II-II in FIG. [Figure 3] FIG. 3 is a perspective view showing the appearance of the projector according to the first embodiment. [Figure 4A] FIG. 4A is a diagram showing a fluorescent light emitting module in the projector according to the first embodiment. [Figure 4B] FIG. 4B is a diagram showing the energy efficiency of transmitted light according to the first embodiment. [Figure 5A] FIG. 5A is a perspective view of a mold for manufacturing the phosphor substrate according to the first embodiment. [Figure 5B] FIG. 5B is a diagram showing the relationship between the Ce concentration of YAG:Ce and the thickness of the phosphor substrate according to the first embodiment. [Figure 5C] FIG. 5C shows the relationship between the Ce concentration of YAG:Ce and the temperature of the phosphor substrate according to the first embodiment. [Figure 5D] FIG. 5D shows the relationship between the spot size expansion ratio of the phosphor substrate according to the first embodiment. [Figure 6] FIG. 6 is a cross-sectional view of a phosphor substrate according to another example 1 of the second embodiment. [Figure 7] FIG. 7 is a cross-sectional view of a phosphor substrate according to Alternative Example 2 of Embodiment 2. As shown in FIG. [Figure 8] FIG. 8 is a perspective view of the fluorescence light-emitting module according to the first embodiment. [Figure 9] 9 is a cross-sectional view showing a cut surface of a part of the fluorescent light-emitting module taken along line IX-IX in FIG. [Figure 10] FIG. 10 is a schematic diagram showing the configuration of the projector according to the first embodiment. [Figure 11] FIG. 11 is a perspective view of a fluorescence light-emitting module according to the third embodiment. [Figure 12] 12 is a cross-sectional view showing a cut surface of a part of the fluorescent light-emitting module taken along line XII-XII in FIG. [Figure 13] FIG. 13 is a perspective view of a fluorescence light-emitting module according to the fourth embodiment. [Figure 14] FIG. 14 is a perspective view of a mold for manufacturing the phosphor substrate according to the fourth embodiment. [Figure 15] FIG. 15 is a perspective view of a fluorescence light-emitting module according to the fifth embodiment. [Figure 16] 16 is a cross-sectional view showing a cut surface of a part of the fluorescent light-emitting module taken along line XVI-XVI in FIG. [Figure 17] FIG. 17 is a perspective view of a fluorescence light-emitting module according to the sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, a fluorescence light emitting module according to an embodiment of the present invention will be described in detail with reference to the drawings.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] In this specification and drawings, the x-axis, y-axis, and z-axis represent the three axes of a three-dimensional Cartesian coordinate system. In each embodiment, the direction parallel to the axis direction is defined as the z-axis, and the two axes perpendicular to the z-axis are defined as the x-axis and y-axis.

[0018] (Embodiment 1) [Fluorescence module configuration] First, the configuration of a fluorescence-emitting module 1c according to the present embodiment will be described with reference to the drawings. Fig. 8 is a perspective view of the fluorescence-emitting module 1c according to the present embodiment. Fig. 9 is a cross-sectional view showing a cut surface of a part of the fluorescence-emitting module 1c taken along line IX-IX in Fig. 8.

[0019] As shown in FIGS. 8 and 9 , the fluorescence-emitting module 1c is a module including a phosphor substrate 10c made of a sintered phosphor, an anti-reflection layer 30, a blue-transmitting dichroic multilayer film 40, a rotating unit 100, a fourth optical element 304, and two light-emitting units 200. For simplicity, only one light-emitting unit 200 is shown in FIG. 8 . This same designation may also be used in the following figures. The fluorescence-emitting module 1c may also include only one light-emitting unit 200. The fluorescence-emitting module 1c is used in light-emitting devices such as projectors and lighting devices. In this embodiment, a projector using the fluorescence-emitting module 1c will be described as an example. The phosphor substrate 10c is used as a light-transmitting phosphor wheel that receives excitation light L1 and emits transmitted light L2 containing fluorescence. The transmitted light L2 is used as projection light output by the projector.

[0020] The components of the fluorescence light-emitting module 1c will be described below.

[0021] <Explanation of the light output part> The light emitting unit 200 is a light source that emits excitation light L1. The excitation light L1 is light that excites the phosphor substrate 10c, which is a sintered phosphor. In other words, the excitation light L1 is light that excites the phosphor material contained in the sintered phosphor that constitutes the phosphor substrate 10c. Note that FIG. 9 shows a side view of the light emitting unit 200. The light emitting unit 200 is, for example, a semiconductor laser light source or an LED (Light Emitting Diode) light source, and is driven by a drive current to emit excitation light L1 of a predetermined color (wavelength).

[0022] In 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 two light emitting units 200 may be multi-chip type lasers as shown in Japanese Patent Application Laid-Open No. 2016-219779, which is a patent document, or the collimating lens and the TO-can may be separate entities.

[0023] 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.

[0024] <Explanation of rotating parts> The rotating unit 100 is a member that rotates the phosphor substrate 10c around an axis A1 extending in the thickness direction (z-axis direction) of the phosphor substrate 10c, and is, for example, a motor. More specifically, in this embodiment, the rotating unit 100 rotates the phosphor substrate 10c, the anti-reflection layer 30, and the blue-transmitting dichroic multilayer film 40 around the axis A1 in the direction of the arrow shown in FIG. 8. When the center of the circular phosphor substrate 10c in a planar view is defined as a center point C1, the axis A1 passes through the center point C1, i.e., penetrates the phosphor substrate 10c. Here, the planar view is when the fluorescence-emitting module 1c is viewed from the positive direction of the z-axis. Note that the internal components of the rotating unit 100 are omitted from the illustration in FIG. 9.

[0025] As shown in FIG. 9, the phosphor substrate 10c is provided at a position overlapping with the rotating portion 100 in plan view.

[0026] <Fourth optical element> 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 Excitation light L1 9 shows a side view of the fourth optical element 304.

[0027] <Explanation of phosphor substrate> The phosphor substrate 10c is a substrate made of a sintered phosphor having a phosphor material, and is a substrate having a circular shape as described above. That is, the phosphor substrate 10c has a disk shape having a flat surface. Specifically, here, the phosphor substrate 10c is a substrate made only of a sintered phosphor, and the sintered phosphor has only the phosphor material as a main component.

[0028] Here, the sintered phosphor in the present embodiment will be described.

[0029] A sintered phosphor is a fired body obtained by firing raw material powder of a phosphor material (as an 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. Further, 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 to each other. 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. Further, as the binder, Al2O3 materials, glass materials (that is, SiO d (0 < d ≤ 2)) and the like are used as known materials. Similarly, not limited to the binder, the sintered phosphor hardly requires materials other than the phosphor material that the sintered phosphor has (hereinafter referred to as other materials), and more specifically, does not require any other materials at all.

[0030] For example, when the total volume of the sintered phosphor is 100 vol%, the volume of the phosphor material in the total volume of the sintered phosphor is preferably 70 vol% or more. Further, it is more preferable that the volume of the phosphor material in the total volume of the sintered phosphor is 80 vol% or more, even more preferable that it is 90 vol% or more, and even more preferable that it is 95 vol% or more.

[0031] In other words, when the total volume of the sintered phosphor is 100 vol%, the volume of other materials (such as a binder) in the total volume of the sintered phosphor is preferably less than 30 vol%. Further, it is more preferable that the volume of other materials (such as a binder) in the total volume of the sintered phosphor is less than 20 vol%, even more preferable that it is less than 10 vol%, and even more preferable that it is less than 5 vol%.

[0032] 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%.

[0033] Here, the phosphor material will be described. 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:Ce.

[0034] In addition, when the phosphor material is composed of YAG:Ce, Al2O3 may be used as a raw material. In this case, in the sintered phosphor, Al2O3 may remain as an unreacted raw material. However, the unreacted raw material Al2O3 is different from the above binder. Also, when the total volume of the sintered phosphor is 100 vol%, the volume of Al2O3, which is the unreacted raw material in the total volume of the sintered phosphor, is 5 vol% or less.

[0035] Note that the crystal phase constituting the phosphor material may be a solid solution of a plurality of garnet crystal phases with different chemical compositions. Such solid solutions include (Y 1-x Ce x )3Al2Al3O 12 a garnet crystal phase represented by (0.001 ≦ x < 0.1) and (Lu 1-y Ce y )3Al2Al3O 12 a solid solution with 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 with 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 broader, and the green light component and the red light component increase. Therefore, a projector that emits projection light with a wide color gamut can be provided.

[0036] In addition, the crystal phase constituting the phosphor material may contain a crystal phase with a chemical composition shifted from the crystal phase represented by the above general formula A3B2C3O 12 Examples of such a crystal phase include (Y 1-x Ce x )3Al2Al3O 12 where Al is rich with respect to the crystal phase represented by (0.001 ≤ x < 0.1), (Y 1-x Ce x )3Al 2+δ Al3O 12 (δ is a positive number). Examples of such a crystal phase also include (Y 1-x Ce x )3Al2Al3O 12 where Y is rich with respect to the crystal phase represented by (0.001 ≤ x < 0.1), (Y 1-x Ce x ) 3+ζ Al2Al3O 12 (ζ is a positive number), etc. These crystal phases have a chemical composition shifted from the crystal phase represented by the general formula A3B2C3O 12 but maintain the garnet structure.

[0037] Furthermore, the crystal phase constituting the phosphor material may contain a heterogeneous phase having a structure other than the garnet structure.

[0038] In the present embodiment, the phosphor material composed of YAG:Ce receives the light incident from the negative z-axis direction of the phosphor substrate 10c as excitation light L1 and emits fluorescence. More specifically, when the light emitted from the light emitting unit 200 is irradiated onto the phosphor material as excitation light L1, fluorescence is emitted from the phosphor material as wavelength-converted light. That is, the wavelength-converted light emitted from the phosphor material is light having a wavelength longer than the wavelength of the excitation light L1.

[0039] 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:Ce 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.

[0040] As described above, a portion of the excitation light L1 incident on the phosphor material is wavelength-converted by the phosphor material and passes through the phosphor substrate 10c. The remaining portion of the excitation light L1 passes through the phosphor substrate 10c without being wavelength-converted by the phosphor material. The transmitted light L2 that passes through the phosphor substrate 10c 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 two types of light, and is white light. For example, if the balance between fluorescence and excitation light L1 in the transmitted light L2 is disrupted, the chromaticity of the transmitted light L2 will change. More specifically, if the fluorescence decreases, the proportion of excitation light L1 increases, and the proportion of blue light in the transmitted light L2 will increase.

[0041] As shown in FIG. 8, in this embodiment, the excitation light L1 is irradiated onto a position at a radius R from the center point C1 of the phosphor substrate 10c.

[0042] <Explanation of the coating layer> <Blue-transmitting dichroic multilayer film> The blue-transmission dichroic multilayer film 40 is located in the negative z-axis direction of the phosphor substrate 10c. The blue-transmission dichroic multilayer film 40 has a transmission-reflection characteristic of transmitting excitation light L1 and reflecting fluorescence. In this embodiment, the blue-transmission dichroic multilayer film 40 has a transmission-reflection characteristic of transmitting blue light and reflecting yellow light.

[0043] Specifically, the blue-transmitting dichroic multilayer film 40 is composed of dichroic layers made of dielectric multilayer films, etc. By controlling the dielectric materials and / or the configuration of the multilayer films that make up the dichroic layers, the blue-transmitting dichroic multilayer film 40 can have a predetermined reflectance for a predetermined wavelength and high transmission characteristics for blue wavelengths.

[0044] For example, if such a blue-transmission dichroic multilayer film 40 were not provided, a portion of the fluorescence generated in the phosphor material would be emitted from the phosphor substrate 10c in the negative direction of the z-axis and would not be usable as projection light for the projector. By providing the blue-transmission dichroic multilayer film 40, this portion of the fluorescence would be reflected by the blue-transmission dichroic multilayer film 40 in the positive direction of the z-axis. This means that the entire fluorescence generated in the phosphor material in the phosphor substrate 10c is more likely to be directed in the positive direction of the z-axis. This improves the light utilization efficiency of the fluorescence-emitting module 1c. Furthermore, the blue-transmission dichroic multilayer film 40 also functions as an anti-reflection film for the excitation light L1 (blue light), enabling an increased amount of excitation light L1 incident on the phosphor substrate 10c compared to a case where the blue-transmission dichroic multilayer film 40 is not provided.

[0045] <Anti-reflection layer> Furthermore, an antireflection layer 30 is located in the positive direction of the z-axis of the phosphor substrate 10c.

[0046] The antireflection layer 30 is a layer that prevents, or more specifically, suppresses, reflection of the transmitted light L2. That is, the antireflection layer 30 is a layer that suppresses the transmitted light L2 traveling in the positive direction of the z axis from being reflected and traveling in the negative direction of the z axis.

[0047] The anti-reflection layer 30 reduces the reflectance of the transmitted light L2 emitted from the fluorescence light-emitting module 1c, in other words, improves the transmittance of the transmitted light L2, thereby increasing the amount of transmitted light L2 emitted from the fluorescence light-emitting module 1c. As a result, the amount of transmitted light L2 that can be used as projection light for a projector, for example, increases. This makes it possible to improve the light utilization efficiency of the fluorescence light-emitting module 1c.

[0048] The antireflection layer 30 may be composed of, for example, a dielectric film or a fine uneven structure (so-called moth-eye structure) with a period smaller than the wavelength of light in the visible light region. When the antireflection layer 30 is composed of a dielectric film, the antireflection layer 30 can be easily manufactured by including an inorganic compound in the antireflection layer 30. In this case, the antireflection layer 30 includes one or more inorganic compounds selected from SiO2, TiO2, Al2O3, ZnO, Nb2O5, MgF, etc.

[0049] 8 and 9 show a configuration in which an anti-reflection layer 30 and a blue-transmission dichroic multilayer film 40 are provided, the fluorescence-emitting module 1c does not necessarily have to include the anti-reflection layer 30 and the blue-transmission dichroic multilayer film 40. In this case, the rotating section 100 and the phosphor substrate 10c are in contact with each other via an adhesive member.

[0050] The planar shapes of the antireflection layer 30 and the blue transmission dichroic multilayer film 40 are, for example, the same as the shape of the phosphor substrate 10c, i.e., a circle. Although not shown, the antireflection layer 30 and the blue transmission dichroic multilayer film 40 may also be annular, arranged to overlap the position where the excitation light L1 is irradiated in planar view. In this case, the center of the annular shape overlaps with the center point C1 of the phosphor substrate 10c.

[0051] The antireflection layer 30 and the blue transmission dichroic multilayer film 40 are sufficiently thinner than the phosphor substrate 10c. For example, the thickness of each of the antireflection layer 30 and the blue transmission dichroic multilayer film 40 is, for example, 0.1 μm to 50 μm, but is not limited to this. Therefore, the antireflection layer 30 and the blue transmission dichroic multilayer film 40 are not components for supporting the phosphor substrate 10c.

[0052] <Effect of rotating parts> It is known that when the temperature of the phosphor substrate 10c increases due to irradiation with excitation light L1, a phenomenon occurs in which the emitted fluorescence decreases (so-called temperature quenching phenomenon). For example, when temperature quenching occurs in the fluorescence-emitting module disclosed in Patent Document 1, the fluorescence emitted from the fluorescence generating unit decreases, resulting in problems such as a decrease in the light utilization efficiency of the fluorescence-emitting module.

[0053] Furthermore, the fluorescence-emitting module 1c according to this embodiment is equipped with a rotating part 100. This causes the phosphor substrate 10c and other components to rotate about the axis A1, generating an airflow. This generated airflow cools the phosphor substrate 10c. In other words, the heat dissipation properties of the phosphor substrate 10c are improved. This makes it possible to suppress an increase in the temperature of the phosphor substrate 10c, thereby suppressing a decrease in fluorescence. In other words, the light utilization efficiency of the fluorescence-emitting module 1c can be improved. Furthermore, because a decrease in fluorescence is suppressed, changes in the chromaticity of the transmitted light L2 can be suppressed. This makes it possible to achieve a highly reliable fluorescence-emitting module 1c.

[0054] <Diameter of phosphor substrate> The diameter of the disc-shaped phosphor substrate 10c is, for example, preferably 30 mm to 90 mm, more preferably 35 mm to 70 mm, and even more preferably 40 mm to 50 mm, but is not limited to these.

[0055] <Benefits of no substrate> As described above, the fluorescence-emitting module 1c according to this embodiment does not include components for supporting the phosphor substrate 10c (such as the transparent phosphor substrate disclosed in Patent Document 1). In other words, the fluorescence-emitting module 1c according to this embodiment has a substrate-less structure. Therefore, unlike Patent Document 1, reflection of the excitation light L1 (i.e., optical loss of the excitation light L1) at the interface between the phosphor substrate and the atmosphere does not occur. Because there is no optical loss of the excitation light L1 at the interface, the excitation light L1 incident on the phosphor substrate 10c increases. As a result, the fluorescence generated by the phosphor material in the phosphor substrate 10c increases. In other words, the light utilization efficiency of the fluorescence-emitting module 1c can be improved. Furthermore, because the fluorescence-emitting module 1c does not include components for supporting the phosphor substrate 10c, the peeling of the fluorescence generating unit disclosed in Patent Document 1 does not occur. This results in a highly reliable fluorescence-emitting module 1c.

[0056] <Effect of blue-transmitting dichroic multilayer film> Furthermore, by providing the blue-transmission dichroic multilayer film 40, it is possible to suppress Fresnel reflection of the excitation light L1, which is blue light, at the interface between the atmosphere and the phosphor substrate 10c, which would occur if the blue-transmission dichroic multilayer film 40 were not provided. In other words, the blue-transmission dichroic multilayer film 40 can suppress light loss due to reflection of the excitation light L1. By providing such a blue-transmission dichroic multilayer film 40, the excitation light L1 incident on the phosphor substrate 10c increases. As a result, the fluorescence generated by the phosphor material in the phosphor substrate 10c increases.

[0057] <Effects of sintered phosphor> Further, the effect of the phosphor substrate 10c being made of a sintered phosphor will be described below.

[0058] For example, in Patent Document 1, a transparent resin corresponds to the binder. The refractive index of known binders containing this transparent resin is often different from the refractive index of phosphor materials such as YAG:Ce. Therefore, when phosphor materials such as YAG:Ce are combined with a binder, light scattering occurs. In this case, light loss occurs due to the scattering of light.

[0059] However, as described above, the sintered phosphor according to the present embodiment hardly requires a binder. Therefore, in the sintered phosphor, light loss due to light scattering and the like is unlikely to occur. In other words, by providing the fluorescence light-emitting module 1c with the phosphor substrate 10c made of the sintered phosphor, the light utilization efficiency of the fluorescence light-emitting module 1c can be improved.

[0060] <Adhesion> The rotating part 100 and the phosphor substrate 10c are in contact with each other via an adhesive. Taking into consideration the load on the rotating part 100 itself (the motor) and its thermal conductivity, the rotating part 100 is made of lightweight, highly thermally conductive aluminum. The outer diameter of the rotating part 100 is equal to or less than twice the radius R. Silicone resin is used as the adhesive to reduce the difference in thermal expansion coefficients between the rotating part 100 and the phosphor substrate 10c. However, the rotating part 100 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.

[0061] <Diameter of phosphor substrate> Here, the inventors have studied the relationship between the energy efficiency of the transmitted light L2 and the diameter of the phosphor substrate 10c, and the results of this study are shown in FIG.

[0062] 4B is a diagram showing the energy efficiency of transmitted light L2 according to the present embodiment, showing the results of an investigation into phosphor substrate 10c having a diameter (shown as φ in FIG. 4B) of 5 mm to 90 mm.

[0063] The horizontal axis at the bottom represents the energy of the excitation light L1. Here, the incident area of ​​the excitation light L1 on the phosphor substrate 10c is 2 mm 2 Therefore, the upper horizontal axis indicates the density of excitation energy (excitation density) in the incident area by the excitation light L1.

[0064] The vertical axis represents the energy efficiency of the transmitted light L2. The vertical axis also represents the normalized value of the energy of the transmitted light L2 for each data indicating the diameter of the phosphor substrate 10c, where the energy of the transmitted light L2 when the energy of the excitation light L1 is 0.5 W is set to 100%. For example, for data indicating a phosphor substrate 10c with a diameter of 5 mm, the vertical axis represents the normalized value of the energy of the transmitted light L2 emitted from the phosphor substrate 10c with a diameter of 5 mm when the energy of the excitation light L1 is 0.5 W, where the vertical axis represents the normalized value. Similarly, for data indicating a phosphor substrate 10c with a diameter of 30 mm, the vertical axis represents the normalized value of the energy of the transmitted light L2 emitted from the phosphor substrate 10c with a diameter of 30 mm when the energy of the excitation light L1 is 0.5 W.

[0065] The greater the energy of the excitation light L1, the more likely it is that the temperature of the phosphor substrate 10c will rise, and the more likely it is that thermal quenching will occur. When thermal quenching occurs, the energy of the transmitted light L2 will drop sharply. As shown in Figure 4B, for phosphor substrates 10c with a diameter of 5 mm or greater and 65 mm or less, there is a region where the energy of the transmitted light L2 drops sharply. For example, for a phosphor substrate 10c with a diameter of 30 mm, this region appears when the energy of the excitation light L1 increases from 70 W to 100 W.

[0066] 4B also shows that the larger the diameter of the phosphor substrate 10c, the more this region shifts toward higher energy excitation light L1. In other words, FIG. 4B shows that the larger the diameter of the phosphor substrate 10c, the less likely thermal quenching occurs. This can be explained as follows.

[0067] Heat generated by irradiation with the excitation light L1 moves, for example, from the region irradiated with the excitation light L1 (for example, the position of radius R from the center point C1) to the region not irradiated with the excitation light L1. The larger the diameter of the phosphor substrate 10c, the larger the region not irradiated with the excitation light L1. This region not irradiated with the excitation light L1 corresponds to the region to which heat moves from the region irradiated with the excitation light L1. Therefore, the larger the diameter of the phosphor substrate 10c, the easier it is for heat generated by irradiation with the excitation light L1 to move, making it less likely that the temperature of the phosphor substrate 10c will rise. As a result, the thermal quenching phenomenon is less likely to occur. In other words, the larger the diameter of the phosphor substrate 10c, the more efficiently transmitted light L2 can be obtained in regions where the energy of the excitation light L1 is high.

[0068] Furthermore, the inventors' studies have revealed that, for example, in order to achieve an output light of 15,000 lm from light source module 600, the energy of excitation light L1 needs to be approximately 100 W. Note that light source module 600, which will be described in detail in FIG. 4A, is an optical module including a fluorescent light-emitting module 1c and optical elements.

[0069] As described above, the diameter of the phosphor substrate 10c is, for example, preferably 30 mm or more and 90 mm or less, more preferably 35 mm or more and 70 mm or less, and even more preferably 40 mm or more and 50 mm or less.

[0070] When the diameter of the phosphor substrate 10c is within the above range, it is possible to obtain highly efficient transmitted light L2 (for example, 90% or more on the vertical axis of FIG. 4B) when the energy of the excitation light L1 is 100 W.

[0071] That is, the diameter of the phosphor substrate 10c is appropriately set according to the output light of the light source module 600. Note that if the diameter of the phosphor substrate 10c is large, the size of the light source module 600 increases. As a result, the size of the light-emitting device such as the projector 500 and the lighting device increases, and the commercial value of the light-emitting device decreases.

[0072] Therefore, for example, when the output light of the light source module 600 is 15,000 lm as described above, the diameter of the phosphor substrate 10c is preferably 40 mm or more and 50 mm or less.

[0073] <Thickness of phosphor substrate> The thickness of the phosphor substrate 10c (i.e., the length in the z-axis direction) is preferably 50 μm to 700 μm, more preferably 80 μm to 500 μm, and even more preferably 100 μm to 300 μm.

[0074] The thicker the phosphor substrate 10c, the higher the thermal conductivity of the phosphor substrate 10c, which means that the heat dissipation properties of the phosphor substrate 10c are improved.

[0075] On the other hand, the thicker the phosphor substrate 10c, the more easily the excitation light L1 is scattered by the phosphor substrate 10c. As a result, the light-emitting spot area of ​​the transmitted light L2 on the phosphor substrate 10c increases when viewed from above. As a result, for example, in a projector, optical elements such as lenses arranged on the optical path of the transmitted light L2 become larger, which causes problems such as an increase in the size of the projector itself.

[0076] Furthermore, the thicker the phosphor substrate 10c, the larger the volume of the phosphor substrate 10c. As a result, a larger amount of phosphor material and highly thermally conductive material is required to manufacture one phosphor substrate 10c, which is also disadvantageous in terms of cost.

[0077] For these reasons, it is preferable that the thickness of the phosphor substrate 10c is within the above range.

[0078] [Study of Ce concentration] As described above, the phosphor material according to the present embodiment is YAG:Ce((Y 1-x Ce x )3AlO 12)(0.0001 ≦ x < 0.1)). Here, the Ce concentration in YAG:Ce will be described. The Ce concentration is the elemental ratio of Ce to the total of Y and Ce (that is, Ce / (Y + Ce) (%)), and is a numerical value of x × 100 (%).

[0079] <Ce Concentration and Thickness> First, the relationship between the Ce concentration and the thickness of the phosphor substrate 10c will be described.

[0080] The inventors examined the output light of the light source module 600 shown in FIG. 4A (that is, the transmitted light L2) to be white light as an example. More specifically, in the CIE color system, the relationship between the Ce concentration of YAG:Ce and the thickness of the phosphor substrate 10c was examined such that the chromaticity coordinates (x, y) of this output light were within (0.308 or more and 0.318 or less, 0.324 or more and 0.334 or less). The results of this examination are shown in FIG. 5B. The CIE color system is a color system defined by the CIE (International Commission on Illumination).

[0081] FIG. 5B is a diagram showing the relationship between the Ce concentration of YAG:Ce and the thickness of the phosphor substrate 10c according to the present embodiment.

[0082] In FIG. 5B, the vertical axis represents the thickness of the phosphor substrate 10c, and the horizontal axis represents the Ce concentration. Here, examinations are being conducted at Ce concentrations of 0.01%, 0.05%, 0.1%, 0.2%, and 0.3% respectively.

[0083] In FIG. 5B, the thicknesses of three phosphor substrates 10c are shown at each Ce concentration. At each Ce concentration, when the thickness of the phosphor substrate 10c is within the above three ranges (more specifically, within the range from the thinnest thickness to the thickest thickness), the output light of the light source module 600 becomes white light (that is, light with chromaticity coordinates within the above range). In other words, when the relationship between the Ce concentration of YAG:Ce and the thickness of the phosphor substrate 10c shown in FIG. 5B is satisfied, the chromaticity coordinates of the output light of the light source module 600 are within the above range.

[0084] In FIG. 5B, it is shown that the lower the Ce concentration, the thicker the phosphor substrate 10c. In the YAG:Ce according to the present embodiment, since Ce functions as an emission center, the lower the Ce concentration, the less wavelength-converted light is generated. Therefore, in order for the chromaticity coordinates of the output light to be within the above range, the lower the Ce concentration, the thicker the phosphor substrate 10c.

[0085] The thicker the phosphor substrate 10c, for example, the less likely the phosphor substrate 10c is to break, such as being less likely to crack. Therefore, the thicker the phosphor substrate 10c, the higher the reliability of the phosphor substrate 10c, that is, the fluorescence emission module 1c. For example, if the thickness of the phosphor substrate 10c is 100 μm or more, the reliability of the fluorescence emission module 1c can be sufficiently increased. Therefore, the Ce concentration is preferably 0.1% or less.

[0086] Furthermore, the examination conducted regarding the relationship between the Ce concentration and the temperature of the phosphor substrate 10c will be described using FIG. 5C. Also in this examination, as in the above, the relationship between the Ce concentration and the thickness of the phosphor substrate 10c shown in FIG. 5B is satisfied so that the chromaticity coordinates of the output light of the light source module 600 are within the above range.

[0087] <Ce Concentration and Temperature> FIG. 5C shows the relationship between the Ce concentration of YAG:Ce according to the present embodiment and the temperature of the phosphor substrate 10c. More specifically, in FIG. 5C, the temperature of the phosphor substrate 10c when the excitation light L1 is irradiated is shown for each Ce concentration shown in FIG. 5C. At this time, in the light source module 600, the phosphor substrate 10c and the like are rotated at 7200 rpm. As described above, also in FIG. 5C, the relationship between the Ce concentration and the phosphor substrate 10c shown in FIG. 5B is satisfied. That is, the lower the Ce concentration, the thicker the phosphor substrate 10c.

[0088] As shown in FIG. 5C, the lower the Ce concentration, the lower the temperature of the phosphor substrate 10c. Further, as shown in FIG. 5B, since the lower the Ce concentration, the thicker the phosphor substrate 10c, heat due to irradiation with the excitation light L1 is likely to move. Therefore, the lower the Ce concentration, the more the increase in the temperature of the phosphor substrate 10c is suppressed. That is, the lower the Ce concentration, the more the temperature quenching phenomenon can be suppressed.

[0089] In addition, the inventors have clarified that in order to sufficiently suppress the temperature quenching phenomenon, it is necessary to keep the temperature of the phosphor substrate 10c at 150° C. or lower. Therefore, from the viewpoint of suppressing the temperature quenching phenomenon, the Ce concentration is preferably 0.1% or less.

[0090] Furthermore, the study conducted on the relationship between the Ce concentration and the spot size expansion ratio will be described. In this study as well, as in the above, the relationship between the Ce concentration shown in FIG. 5B and the thickness of the phosphor substrate 10c is satisfied so that the chromaticity coordinates of the output light of the light source module 600 are within the above range.

[0091] FIG. 5D shows the relationship with the spot size expansion ratio of the phosphor substrate 10c according to the present embodiment. The spot size expansion ratio indicates the ratio between the incident area where the excitation light L1 is incident and the exit area where the transmitted light L2 exits on the phosphor substrate 10c. More specifically, the spot size expansion ratio is a value indicated by exit area / incident area (%). Further, the exit area has the same meaning as the above-described light emission spot area.

[0092] <Ce Concentration and Spot Size> As shown in FIG. 5D, the higher the Ce concentration, the lower the spot size expansion ratio. Further, as shown in FIG. 5B, since the higher the Ce concentration, the thinner the phosphor substrate 10c, the optical path of the excitation light L1 and the wavelength-converted light in the phosphor substrate 10c is short. Therefore, light scattering of the excitation light L1 and the wavelength-converted light in the phosphor substrate 10c is suppressed. Thus, the higher the Ce concentration, the more the increase in the spot size expansion ratio can be suppressed.

[0093] As explained in [Projector Configuration], if the light emission spot area of ​​transmitted light L2 is large, first optical element 301 and second optical element 302 that collect transmitted light L2 will become large, which will also result in a large projector 500. Conversely, by lowering the spot size expansion rate and reducing the light emission spot area of ​​transmitted light L2, projector 500 can be made more compact.

[0094] The inventors have also clarified that, for example, in order to apply the fluorescent light-emitting module 1c to the projector 500, the spot size expansion rate needs to be 250% or less. In other words, the Ce concentration should be 0.05% or more.

[0095] <Summary> From the above, the inventors' investigations have revealed that the phosphor material is YAG:Ce((Y 1-x Ce x )3AlO 12 )(0.0005≦x<0.001)).

[0096] This reduces the possibility of damage to the phosphor substrate 10c, thereby improving the reliability of the fluorescence-emitting module 1c. Furthermore, the temperature quenching phenomenon in the phosphor substrate 10c can be suppressed, resulting in a fluorescence-emitting module 1c with high light utilization efficiency. Furthermore, the projector 500, which is an example of a light-emitting device, can be made more compact.

[0097] The Ce concentration is more preferably 0.06% or more and 0.09% or less, and even more preferably 0.07% or more and 0.08% or less.

[0098] [Manufacturing method] Here, a method for manufacturing the phosphor substrate 10c will be briefly described.

[0099] The phosphor material is (Y 0.999 Ce 0.001 )3AlO 12 The phosphor materials are all composed of a crystalline phase expressed by Ce.3+ It is composed of activated phosphor.

[0100] To manufacture the phosphor substrate 10c, the following three types of compound powder were used as raw materials. Specifically, the raw materials were Y2O3, Al2O3, and CeO2. The purity and manufacturers of the respective materials were: Y2O3, 3N purity, from Nippon Yttrium Co., Ltd.; Al2O3, 3N purity, from Sumitomo Chemical Co., Ltd.; and CeO2, 3N purity, from Nippon Yttrium Co., Ltd.

[0101] Stoichiometric compounds (Y 0.999 Ce 0.001 )3AlO 12 As the raw materials, Y2O3, Al2O3, and CeO2 were weighed out so that the ratio of the raw materials to the total weight of the mixture was 1000. Next, the weighed raw materials and alumina balls (diameter 10 mm) 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.

[0102] The mixed raw materials were granulated using a spray dryer. Polyvinyl alcohol was used as a binder during granulation.

[0103] 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 with a bottom. The molding pressure was 5 MPa.

[0104] Next, the pre-molded molded body was subjected to final molding 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 (de-binder 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.

[0105] The molded body after the heat treatment was fired in a tubular atmosphere furnace at a firing temperature of 1675°C for 4 hours in a mixed gas atmosphere of nitrogen and hydrogen.

[0106] The cylindrical fired product after firing was sliced ​​using a multi-wire saw. The sliced ​​fired product was then polished to adjust the thickness of the fired product. This adjustment resulted in the fired product becoming the phosphor substrate 10c.

[0107] [Projector configuration] Next, projector 500 will be described. Fluorescence-emitting module 1c configured as described above is used in projector 500 and a lighting device (not shown) shown in FIG. 3. FIG. 3 is a perspective view showing the appearance of projector 500 according to this embodiment. FIG. 10 is a schematic diagram showing the configuration of projector 500 according to this embodiment. FIG. 4A is a schematic diagram showing fluorescence-emitting module 1c in projector 500 according to this embodiment. Note that, like FIG. 9, FIG. 4A shows a cross-sectional view of a portion of fluorescence-emitting module 1c, two light-emitting sections 200 in a side view, and the internal components of rotating section 100 are omitted.

[0108] As shown in FIG. 10 , the projector 500 according to this embodiment includes a light source module 600. Similar to known projectors, the projector 500 also includes a uniformizing optical system 601, a display element unit 602, a light projecting unit 603, and a control circuit 604 that controls the display element unit 602. The uniformizing optical system 601 is configured with two multi-lens arrays (MLAs). The display element unit 602 is a substantially planar element that controls transmitted light L2 that is output from the fluorescence emission module 1c and passes through the uniformizing optical system 601 to output an image. In other words, the display element unit 602 generates light for the image. Specifically, the display element unit 602 is a transmissive liquid crystal panel. The display element unit 602 separates the transmitted light L2 into red light, green light, and blue light. The separated red light, green light, and blue light are then optically modulated by the corresponding display element units 602. As a result, an image is generated, and the red, green, and blue lights are wavelength-combined by a cross prism (not shown), which serves as an RGB combining unit. The light projecting unit 603 is a Tessar type. The transmitted light L2 output from the fluorescence light-emitting module 1c is controlled by the uniformizing optical system 601, the display element unit 602, and the light projecting unit 603, in that order, to become projected light that is enlarged and projected onto, for example, a screen. The control circuit 604 is a circuit that controls the display element unit 602 and is realized, for example, by a microcomputer, but may also be realized by a processor. However, this configuration is not limited to this, and the uniformizing optical system 601 may be a kaleidoscope-type structure such as a light pipe. Furthermore, projectors and light-emitting devices that do not require uniformity in the projected image may not have the uniformizing optical system 601. The display element unit 602 may be a DMD (Digital Micromirror Device) or LCOS (Liquid Crystal on Silicon). Furthermore, for example, the display element unit 602 may be a reflective liquid crystal panel or a DLP (Digital Light Processing) having a DMD. In time-division and monochrome projectors and light-emitting devices, the transmitted light L2 does not need to be separated into red, green, and blue light. The light projecting unit 603 may be of another type, such as a Gaussian type.

[0109] Furthermore, light source module 600 is an optical module including fluorescence light-emitting module 1c, first optical element 301, second optical element 302, and third optical element 303. In other words, projector 500, which is an example of a light-emitting device, includes fluorescence light-emitting module 1c.

[0110] The first optical element 301, the second optical element 302, and the third optical element 303 are optical components for controlling the optical path of the transmitted light L2 output from the fluorescence-emitting module 1c. As an example, the first optical element 301, the second optical element 302, and the third optical element 303 are each a lens for focusing the transmitted light L2. As described above, the thicker the phosphor substrate 10c, the larger the light-emitting spot area of ​​the transmitted light L2 due to scattering. In this case, the first optical element 301, the second optical element 302, and the third optical element 303 become larger, and accordingly, the projector 500 also becomes larger. Therefore, it is necessary to control the light-emitting spot area of ​​the transmitted light L2, that is, to control the thickness of the phosphor substrate 10c.

[0111] As described above, the fourth optical element 304 collects and controls the optical path of the excitation light L1 output from the two light emitting units 200.

[0112] Next, the behavior of light in FIG. 4A will be described.

[0113] The excitation light L1 emitted by the light emitting unit 200 is incident on the blue-transmitting dichroic multilayer film 40 via the fourth optical element 304. The excitation light L1 then enters the phosphor substrate 10c. A portion of the incident excitation light L1 is wavelength-converted by the phosphor material and passes through the phosphor substrate 10c as fluorescence. The other portion of the incident excitation light L1 passes through the phosphor substrate 10c without being wavelength-converted by the phosphor material. The transmitted light L2 that passes through the phosphor substrate 10c is a composite light containing the fluorescence, which is yellow light, and the excitation light L1, which is blue light that has not been wavelength-converted, and is therefore white light. The transmitted light L2 then enters the anti-reflection layer 30. The transmitted light L2 then exits the fluorescence-emitting module 1c (more specifically, the phosphor substrate 10c) with a substantially Lambertian light distribution.

[0114] The transmitted light L2 emitted from the fluorescence-emitting module 1c 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 fluorescence-emitting module 1c. 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 fluorescence-emitting module 1c is used.

[0115] The transmitted light L2 (i.e., the output light of the light source module 600) emitted from the first optical element 301, the second optical element 302, and the third optical element 303 proceeds to the uniformizing optical system 601. As described above, the transmitted light L2 output from the light source module 600 is controlled in the order of the uniformizing optical system 601, the display element unit 602, and the light projecting unit 603, and 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.

[0116] Furthermore, in this embodiment, a portion of the excitation light L1 is wavelength-converted by the phosphor material and passes through the phosphor substrate 10c. The other portion of the excitation light L1 passes through the phosphor substrate 10c without being wavelength-converted by the phosphor material. In this way, transmitted light L2 that has passed through the phosphor substrate 10c can be used as, for example, projection light. In other words, a fluorescence light-emitting module 1c that can be used as a light-transmitting phosphor wheel is realized.

[0117] Furthermore, in this embodiment, projector 500, which is an example of a light emitting device, includes fluorescent light emitting module 1c with high light utilization efficiency, thereby realizing projector 500 with high light utilization efficiency.

[0118] <Placement> As described above, the transmitted light L2 is emitted from the phosphor substrate 10c with a substantially Lambertian light distribution. In order to efficiently control the transmitted light L2 emitted from the phosphor substrate 10c with a substantially Lambertian light distribution, it is necessary to arrange the first optical element 301 close to the phosphor substrate 10c. On the other hand, since it is only necessary for the fourth optical element 304 to focus the excitation light L1 on the phosphor substrate 10c, the distance from the phosphor substrate 10c to the exit surface of the fourth optical element 304 can be made greater than the distance from the phosphor substrate 10c to the incident side surface of the first optical element 301. (For example, in this case, the spot size of the excitation light L1 on the phosphor substrate 10c is smaller than the spot size of the transmitted light L2.) Therefore, it is preferable to install the rotating unit 100 in the negative direction of the z-axis of the phosphor substrate 10c so that there is no interference between the rotating unit 100 and the optical elements (first optical element 301, second optical element 302, third optical element 303, and fourth optical element 304).

[0119] (Embodiment 2) [Fluorescence module configuration] Next, a fluorescence-emitting module 1 according to a second embodiment will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a perspective view of the fluorescence-emitting module 1 according to the present embodiment. Fig. 2 is a cross-sectional view showing a cut surface of a part of the fluorescence-emitting module 1 taken along line II-II in Fig. 1.

[0120] The fluorescence light-emitting module 1 is a module including a phosphor substrate 10 made of a sintered phosphor, an anti-reflection layer 30, a blue-transmitting dichroic multilayer film 40, a rotating unit 100, and two light-emitting units 200. For simplicity, only one light-emitting unit 200 is shown in FIGS. 1 and 2.

[0121] That is, in this embodiment, the phosphor substrate 10 is different from the phosphor substrate 10c according to the first embodiment in that the phosphor substrate 10 is made of a sintered phosphor having a phosphor material and a highly thermally conductive material.

[0122] <Explanation of phosphor substrate> The phosphor substrate 10 is a substrate composed of a sintered phosphor having a phosphor material and a high thermal conductivity material, and is a substrate having a circular shape as described above. That is, the phosphor substrate 10 has a disk shape having a plane. Specifically, here, the phosphor substrate 10 is a substrate composed only of a sintered phosphor, and the sintered phosphor has only a phosphor material and a high thermal conductivity material as main components.

[0123] More specifically, as shown in FIG. 2, the phosphor substrate 10 is composed of a phosphor structure 11 and a plurality of thermal conduction structures 12. The phosphor structure 11 is a structure composed of the phosphor material included in the sintered phosphor. The plurality of thermal conduction structures 12 are a plurality of structures composed of the high thermal conductivity material included in the sintered phosphor.

[0124] Here, the sintered phosphor in the present embodiment will be described.

[0125] The sintered phosphor is a fired body in which raw material powders of the phosphor material and the high thermal conductivity material (as an example, granulated bodies obtained by granulating raw material powders of these materials), which are the above main components, are fired at a temperature lower than the melting points of these materials. 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 Patent Document 1, the binder is a transparent resin. Also, the binder includes Al2O3 materials and glass materials (that is, SiO d (0 < d ≤ 2)) and the like are used as known materials. Similarly, not limited to the binder, the sintered phosphor hardly requires materials other than the phosphor material and the high thermal conductivity material included in the sintered phosphor (hereinafter referred to as other materials), and more specifically, does not require any other materials at all.

[0126] For example, when the total volume of the sintered phosphor is 100 vol%, the total volume of the phosphor material and the high thermal conductive material in the total volume of the sintered phosphor is preferably 70 vol% or more. In addition, the total volume of the phosphor material and the high thermal conductive material in the total volume of the sintered phosphor is more preferably 80 vol% or more, even more preferably 90 vol% or more, and even more preferably 95 vol% or more.

[0127] In other words, when the total volume of the sintered phosphor is 100vol%, the volume of other materials (for example, binder) in the total volume of the sintered phosphor is preferably less than 30vol%. Also, the volume of other materials (for example, binder) in the total volume of the sintered phosphor is more preferably 20vol% or less, even more preferably 10vol% or less, and even more preferably 5vol% or less.

[0128] <High thermal conductivity material> Next, the multiple heat conduction structures 12 made of a highly thermally conductive material will be described. The shape of the highly thermally conductive material, more specifically, the shape of each of the multiple heat conduction structures 12, is, for example, a particulate shape. The multiple heat conduction structures 12 made of a highly thermally conductive material are arranged on the phosphor substrate 10 so as to be surrounded by the fluorescent structure 11. Although not shown, the multiple heat conduction structures 12 may be arranged so that a portion of each of the multiple heat conduction structures 12 protrudes from the fluorescent structure 11. The fluorescent structure 11 serves as a base material for the multiple heat conduction structures 12. In other words, the multiple heat conduction structures 12 are embedded in the fluorescent structure 11. Some of the multiple heat conduction structures 12 are in contact with each other, i.e., in a so-called string-like state. The particle diameter of each of the multiple heat conduction structures 12, which is in a particulate shape, is, for example, 1 μm or more and 100 μm or less.

[0129] It is known that when the temperature of the phosphor substrate 10 increases due to irradiation with excitation light L1, a phenomenon occurs in which the emitted fluorescence decreases (so-called temperature quenching phenomenon). For example, when temperature quenching occurs in the fluorescence-emitting module disclosed in Patent Document 1, the fluorescence emitted from the fluorescence generating unit decreases, resulting in problems such as a decrease in the light utilization efficiency of the fluorescence-emitting module.

[0130] However, in the present embodiment, since the sintered phosphor contains a highly thermally conductive material, the decrease in fluorescence is suppressed. Specifically, as described below.

[0131] A high thermal conductivity material has a thermal conductivity of 100 W / m·K or more and 300 W / m·K or less, which is higher than that of phosphor materials such as YAG:Ce. Furthermore, the thermal conductivity of a high thermal conductivity material is preferably 130 W / m·K or more and 200 W / m·K or less, and even more preferably 145 W / m·K or more and 170 W / m·K or less. When the sintered phosphor constituting the phosphor substrate 10 contains a high thermal conductivity material, heat generated in the phosphor substrate 10 is easily transferred. In other words, the heat dissipation properties of the phosphor substrate 10 are improved. This suppresses the temperature rise of the phosphor substrate 10 due to irradiation with excitation light L1, thereby suppressing the decrease in fluorescence. In other words, a fluorescence-emitting module 1 with high light utilization efficiency is realized. Furthermore, because the decrease in fluorescence is suppressed, changes in the chromaticity of the transmitted light L2 can be suppressed. Therefore, a fluorescence-emitting module 1 with high reliability is realized.

[0132] Furthermore, when each of the multiple heat conduction structures 12 has a particle shape and the multiple heat conduction structures 12 are in contact with each other, the heat is more easily transmitted through the multiple heat conduction structures 12, thereby further improving the heat dissipation properties of the phosphor substrate 10.

[0133] <Types of high thermal conductive materials> The high thermal conductivity material according to this embodiment is made of W, but as another example, it may be made of the following metal elements in terms of thermal conductivity, melting point, and linear expansion coefficient.

[0134] The high thermal conductivity material is, for example, a material containing at least one of Rh, Mo, W, SiC, and AlN. The high thermal conductivity material may also be composed of one or more metal elements, alloys, or compounds selected from the above materials. The thermal conductivities of the respective elements are 150 W / m K for Rh, 135 W / m K for Mo, 163 W / m K for W, 200 W / m K for SiC, and 150 W / m K for AlN.

[0135] The thermal conductivity of these high thermal conductive materials is higher than the thermal conductivity of YAG:Ce constituting the phosphor material, which is 11.2 W / m K. Therefore, when the sintered phosphor contains these high thermal conductive materials, the heat dissipation property of the phosphor substrate 10 can be improved.

[0136] Furthermore, the melting point of the high thermal conductivity material at normal pressure is preferably 1700°C or higher and 3500°C or lower. For example, the melting points of the above metal elements and compounds at normal pressure are 1963°C for Rh, 2623°C for Mo, 3422°C for W, 2730°C for SiC, and 2200°C for AlN. When the phosphor substrate 10 is manufactured, it may be subjected to a heat treatment (firing) at a high temperature (e.g., 1650°C). Even in such a case, since the melting point of the high thermal conductivity material at normal pressure is 1700°C or higher, the high thermal conductivity material is prevented from melting during the heat treatment. Therefore, the phosphor substrate 10 constituted by a sintered phosphor having a phosphor material and a high thermal conductivity material can be easily manufactured.

[0137] <Thermal expansion coefficient> The linear expansion coefficient of high thermal conductivity materials is 1×10 -7 / K or less. The linear expansion coefficient of the high thermal conductivity material is preferably 1×10 -6 / K or more. In other words, the linear expansion coefficient of the highly thermally conductive material is preferably 8×10 -6 / K). For example, the linear expansion coefficient of the above metal elements and compounds is 8.2 × 10 for Rh. -6 / K, Mo is 4.8 × 10 -6 / K, W is 4.5 × 10 -6 / K, SiC is 3.7×10 -6 / K, AlN is 4.0 × 10 -6 / K.

[0138] The linear expansion coefficient of the highly thermally conductive material is set to the above value, which is close to the linear expansion coefficient of the phosphor material. Therefore, even if the temperature of the phosphor substrate 10 increases due to irradiation with excitation light L1, peeling between the phosphor material and the highly thermally conductive material is suppressed. In other words, a highly reliable fluorescence-emitting module 1 is realized.

[0139] <Summary> In summary, when the high thermal conductivity material is any one of Rh, Mo, W, SiC, and AlN, the thermal conductivity, linear expansion coefficient, and melting point of the high thermal conductivity material satisfy the above-mentioned values. This improves the heat dissipation of the phosphor substrate 10 and prevents peeling between the phosphor material and the high thermal conductivity material. In other words, a highly reliable fluorescent light-emitting module 1 with high light utilization efficiency is realized. Furthermore, since the high thermal conductivity material is prevented from melting during the manufacturing process of the phosphor substrate 10, the phosphor substrate 10 can be easily manufactured.

[0140] <Ratio of high thermal conductive materials> The ratio of the phosphor material and the highly thermally conductive material in the phosphor substrate 10 is, for example, as follows: When the volume of the phosphor material is taken as 100, the volume of the highly thermally conductive material should be between 1 and several tens. The larger the volume of the highly thermally conductive material, the more the heat dissipation of the phosphor substrate 10 can be improved. When the volume of the highly thermally conductive material is within the above range, sufficient heat dissipation of the phosphor substrate 10 can be achieved.

[0141] <High thermal conductivity segmentation> Furthermore, the phosphor substrate 10 according to this embodiment has a first region 21 and a second region 22. That is, the phosphor substrate 10 according to this embodiment is segmented into the first region 21 and the second region 22. More specifically, in a plan view, the phosphor substrate 10 has the first region 21 and a plurality of second regions 22. Note that in FIG. 1, the first region 21 is indicated by a dot, and in FIG. 2, the first region 21 is indicated by a dashed line, and the plurality of second regions 22 are rectangular regions surrounded by dashed double-dashed lines.

[0142] The first region 21 and the plurality of second regions 22 have different contents of the highly thermally conductive material. The plurality of second regions 22 are regions having a higher content of the highly thermally conductive material than the first region 21. In other words, the first region 21 only needs to have a lower content of the highly thermally conductive material than the plurality of second regions 22, and the first region 21 according to this embodiment does not contain the highly thermally conductive material. However, the first region 21 may contain the highly thermally conductive material. Furthermore, the excitation light L1 emitted by the light emitting unit 200 is incident on the first region 21.

[0143] When excitation light L1 is incident on a highly thermally conductive material (more specifically, a plurality of thermally conductive structures 12 made of a highly thermally conductive material), the excitation light L1 is scattered or absorbed by the plurality of thermally conductive structures 12, resulting in a decrease in the amount of fluorescence generated. Therefore, in a case where the phosphor substrate 10 has a first region 21 and a plurality of second regions 22, when excitation light L1 is incident on the first region 21, which contains a smaller amount of highly thermally conductive material, the amount of fluorescence generated in the first region 21 increases. In other words, the light utilization efficiency of the fluorescence light-emitting module 1 can be further improved. It is preferable that the first region 21 does not contain a highly thermally conductive material. This can increase the efficiency of wavelength conversion by the phosphor material.

[0144] 1, when the phosphor substrate 10 is viewed from above, the first region 21 has an annular shape, and the center of the annular shape coincides with the center point C1 of the phosphor substrate 10. The first region 21 is provided in a circular ring shape on a circumference that is equidistant from the center point C1 of the phosphor substrate 10. In other words, the first region 21 is provided in a band shape along the circumferential direction in the planar view.

[0145] Because the first region 21 has the above-described shape, the rotating unit 100 can more easily rotate the phosphor substrate 10 around the axis A1. In other words, it becomes easier to use the phosphor substrate 10 as a phosphor wheel.

[0146] Furthermore, when the phosphor substrate 10 is viewed from above, the multiple second regions 22 are provided on the inside and outside of the annular shape that is the shape of the first region 21. Of the multiple second regions 22, the second region 22 provided on the inside will be referred to as the "inner second region 22," and the second region 22 provided on the outside of the multiple second regions 22 will be referred to as the "outer second region 22."

[0147] The inner second region 22 has a disk shape, and the center of the disk shape overlaps with the center point C1 of the phosphor substrate 10. The inner second region 22 is in contact with the inner surface of the first region 21. The outer second region 22 has a circular ring shape like the first region 21, and the center of the circular ring shape overlaps with the center point C1 of the phosphor substrate 10. The outer second region 22 is in contact with the outer surface of the first region 21. In other words, the first region 21 is sandwiched between the inner second region 22 and the outer second region 22.

[0148] At this time, the heat generated in the first region 21 by irradiation with the excitation light L1 can be transferred to both of the two second regions 22 that sandwich the first region 21. In this case, the heat dissipation properties of the phosphor substrate 10 can be improved compared to, for example, a case in which the fluorescence-emitting module 1 has the second region 22 only on either the inside or outside of the first region 21. This makes it possible to suppress an increase in the temperature of the phosphor substrate 10, thereby further suppressing a decrease in fluorescence.

[0149] 1 and 2, 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 fluorescent structure 11 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 a 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.

[0150] Furthermore, the fluorescence-emitting module 1 according to the present embodiment may be applied to the projector 500 instead of the fluorescence-emitting module 1c according to the first embodiment. In this case as well, the excitation light L1 is incident on the first region 21 of the phosphor substrate 10. In this way, by having the excitation light L1 incident on the first region 21, which has a lower content of the highly thermally conductive material, the amount of fluorescence can be increased, and the light utilization efficiency of the fluorescence-emitting module 1 can be further improved.

[0151] In this case, a portion of the incident excitation light L1 is wavelength-converted by the phosphor material contained in the first region 21 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 first region 21. In this way, transmitted light L2 that has passed through the phosphor substrate 10 can be used as, for example, projection light. In other words, a fluorescence-emitting module 1 that can be used as a light-transmitting phosphor wheel is realized.

[0152] <Effects of high thermal conductivity materials> Furthermore, in the present embodiment, the sintered phosphor constituting the phosphor substrate 10 has a high thermal conductivity material, thereby improving the heat dissipation of the phosphor substrate 10. This makes it possible to suppress the temperature rise of the phosphor substrate 10 due to irradiation with the excitation light L1, thereby suppressing the decrease in fluorescence and realizing a fluorescence light-emitting module 1 with higher light utilization efficiency.

[0153] Furthermore, since the sintered phosphor constituting the phosphor substrate 10 is a highly thermally conductive material, the heat dissipation of the phosphor substrate 10 is improved and the temperature rise of the phosphor substrate 10 can be suppressed, which makes it possible to increase the energy of the excitation light L1 that can be input with a small-sized phosphor wheel. In other words, it becomes possible to emit a large luminous flux of light from a smaller size. As a specific example, the size of a phosphor wheel used in a projector that outputs 6000 lm of light was previously φ65 mm, but by including 60 vol% W as a highly thermally conductive material, it is possible to reduce the size to φ50 mm.

[0154] In summary, a highly reliable fluorescence light-emitting module 1 with high light utilization efficiency is realized.

[0155] [Manufacturing method] Here, a method for manufacturing the phosphor substrate 10 will be briefly described.

[0156] The phosphor material is (Y 0.999 Ce 0.001 )3AlO 12 The phosphor materials are all composed of a crystalline phase expressed by Ce. 3+ It is composed of activated phosphor.

[0157] The following four types of compound powders were used as raw materials to manufacture the phosphor substrate 10. Specifically, the raw materials were Y2O3, Al2O3, CeO2, and W. The purity and manufacturers of each were as follows: Y2O3, 3N purity, from Nippon Yttrium Co., Ltd.; Al2O3, 3N purity, from Sumitomo Chemical Co., Ltd.; CeO2, 3N purity, from Nippon Yttrium Co., Ltd.; and W, 4N purity, from High Pure Chemical Research Institute Co., Ltd.

[0158] Here, two kinds of mixed raw materials are used: a first mixed raw material that does not contain W, and a second mixed raw material that contains W.

[0159] First, the first mixed raw material will be described. 0.999 Ce 0.001 )3AlO 12 As the raw materials, Y2O3, Al2O3, and CeO2 were weighed out so that the ratio of the raw materials to the total weight of the mixture was 1000. Next, the weighed raw materials and alumina balls (diameter 10 mm) 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. Thereafter, 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 first mixed raw material was obtained.

[0160] The first mixed raw material was granulated using a spray dryer. An acrylic binder was used as the adhesive (binder) during granulation.

[0161] Next, the second mixed raw material will be described. 0.999 Cr 0.001 )5O 12 As the raw materials, Y2O3, Al2O3, and CeO2 were weighed out so that the volume of the W was 10 when the volume of the phosphor material to be produced was taken as 100. Next, the weighed Y2O3, Al2O3, CeO2, and W and alumina balls (diameter 10 mm) were placed in a plastic pot. The following procedure was followed in the same way as for the first mixed raw material, and the second mixed raw material was granulated.

[0162] Next, molding of the first mixed raw material and the second mixed raw material will be described with reference to FIG. 5A.

[0163] FIG. 5A is a perspective view of a mold 400 for manufacturing the phosphor substrate 10 according to this embodiment.

[0164] The granulated first mixed raw material and second mixed raw material were pre-molded into a cylindrical shape using an electric hydraulic press (EMP-5, manufactured by Riken Seiki Co., Ltd.) and a cylindrical mold 400 with a bottom. The molding pressure was 5 MPa. At this time, the first mixed raw material not containing W was placed in the sixth region A4 of the mold 400, and the second mixed raw material containing W was placed in the fifth region A3 and seventh region A5 of the mold 400.

[0165] 5A, a first partition 401 and a second partition 402 are provided inside a mold 400. The first partition 401 and the second partition 402 each have a bottomless cylindrical shape. The diameter of the first partition 401 is smaller than the diameter of the second partition 402, and the first partition 401 is disposed inside the second partition 402. The first partition 401 and the second partition 402 are made of a material (e.g., a resin material) that can be removed by heat treatment or the like.

[0166] The mold 400 is divided into three regions by a first partition 401 and a second partition 402. The three regions are a fifth region A3 having a cylindrical shape located at the center of the mold 400, a sixth region A4 having a bottomless cylindrical shape surrounding the fifth region A3, and a seventh region A5 having a bottomless cylindrical shape surrounding the sixth region A4. The fifth region A3 is surrounded by the first partition 401 and the bottom surface of the mold 400. The sixth region A4 is surrounded by the first partition 401, the second partition 402, and the bottom surface of the mold 400. The seventh region A5 is surrounded by the second partition 402 and the bottom and side surfaces of the mold 400.

[0167] Next, the pre-molded body was subjected to final molding using a cold isostatic pressing device, with the pressure during final molding being 300 MPa.

[0168] The molded body after the heat treatment was fired using a tubular atmosphere furnace. The firing temperature was 1675°C. The firing time was 4 hours. The firing atmosphere was a mixed gas atmosphere of nitrogen and hydrogen. The adhesive used during granulation and the resin material used for the first partition 401 and the second partition 402 were decomposed and removed during the temperature rise process, for example, around 500°C.

[0169] The cylindrical fired product after firing was sliced ​​using a multi-wire saw. The sliced ​​fired product was then polished to adjust the thickness of the fired product. This adjustment resulted in the fired product becoming the phosphor substrate 10.

[0170] The first mixed raw material in the sixth region A4 corresponds to the first region 21 of the phosphor substrate 10. The second mixed raw material in the fifth region A3 corresponds to the inner second region 22 of the phosphor substrate 10, and the second mixed raw material in the seventh region A5 corresponds to the outer second region 22 of the phosphor substrate 10.

[0171] The first partition 401 and the second partition 402 may be made of a metal material. In this case, after the first mixed raw material is placed in the sixth area A4 and the second mixed raw material is placed in the fifth area A3 and the seventh area A5, the first partition 401 and the second partition 402 are removed, for example, by being pulled upward. This allows the first mixed raw material to be held in the sixth area A4 and the second mixed raw material to be held in the fifth area A3 and the seventh area A5.

[0172] (Embodiment 3) [Fluorescence module configuration] Next, a fluorescence-emitting module 1d according to a third embodiment will be described with reference to Fig. 11 and Fig. 12. Fig. 11 is a perspective view of the fluorescence-emitting module 1d according to the present embodiment. Fig. 12 is a cross-sectional view showing a cut surface of part of the fluorescence-emitting module 1d taken along line XII-XII in Fig. 11.

[0173] The fluorescence-emitting module 1d is a module including a phosphor substrate 10d made of a sintered phosphor, an antireflection layer 30, a blue-transmitting dichroic multilayer film 40, a rotating unit (not shown), and two light-emitting units 200. For simplicity, only one light-emitting unit 200 is shown in FIGS. 11 and 12. The rotating unit according to this embodiment has the same configuration as the rotating unit 100 described above. Furthermore, in FIG. 11, the axis A1 on the negative side of the z-axis from the blue-transmitting dichroic multilayer film 40 is not shown. The light-emitting unit 200 emits excitation light L1, as described above.

[0174] The fluorescent light-emitting module 1d of this embodiment differs from the fluorescent light-emitting modules 1c and 1 of embodiments 1 and 2 mainly in that the phosphor substrate 10d is composed of a sintered phosphor having a phosphor material and an oxide material that does not contain a luminescent center element.

[0175] The phosphor substrate 10d is a substrate made of a sintered phosphor having a phosphor material and an oxide material not containing a luminescent center element, and is a substrate having a circular shape. That is, the phosphor substrate 10d is a disk shape having a flat surface. The phosphor substrate 10d is a substrate made only of a sintered phosphor, and the sintered phosphor only has a phosphor material as a main component and an oxide material not containing a luminescent center element.

[0176] More specifically, as shown in Fig. 12, the phosphor substrate 10d is composed of a phosphor structure 11d and an oxide structure 13d. As shown in Fig. 11, the phosphor substrate 10d is provided with the phosphor structure 11d and two oxide structures 13d. That is, the phosphor substrate 10d is composed of the phosphor structure 11d and two oxide structures 13d, and the two oxide structures 13d have the same configuration. Each of the two oxide structures 13d is an area surrounded by a dotted line in Fig. 11.

[0177] The fluorescent structure 11d is a structure constituted by the fluorescent material contained in the sintered phosphor. More specifically, the fluorescent structure 11d is a structure constituted only by the fluorescent material contained in the sintered phosphor.

[0178] The oxide structure 13d is a structure constituted by an oxide material that does not contain a luminescent center element contained in the sintered phosphor. More specifically, the oxide structure 13d is a structure constituted only by an oxide material that does not contain a luminescent center element contained in the sintered phosphor. The oxide structure 13d is also an example of a first light-transmitting region of the phosphor substrate 10d. The first light-transmitting region is a region that is constituted only by an oxide material that does not contain a luminescent center element, among a phosphor material and an oxide material that does not contain a luminescent center element, and transmits light (excitation light L1) that excites the phosphor material.

[0179] As described above, the phosphor substrate 10d is a substrate having a circular shape. More specifically, the phosphor substrate 10d is a substrate whose circular shape is formed by combining the phosphor structure 11d and two oxide structures 13d.

[0180] Here, the oxide structure 13d is an annular sector in plan view of the phosphor substrate 10d. That is, the oxide structure 13d has a shape surrounded by two arcs and two straight lines. Note that the annular sector is a term meaning an annular fan, a frustum of a cone, a sector ring, or the like. Further, the fluorescent structure 11d has an oval shape with a part missing in plan view of the phosphor substrate 10d. That is, by combining the oxide structure 13d with the part of the fluorescent structure 11d, the phosphor substrate 10d has a disk shape.

[0181] Here, as shown in FIG. 11, in plan view of the phosphor substrate 10d, the oxide structure 13d is arranged so that the circumference of the phosphor substrate 10d having a circular shape and the outer arc of the two arcs indicating the oxide structure 13d (that is, the arc farther from the axis A1) overlap.

[0182] Note that the sintered phosphor in the present embodiment will be described here.

[0183] The sintered phosphor is a fired body obtained by firing raw material powders of a phosphor material which is the main component described above and an oxide material not containing a luminescence center element (as an example, a granulated body obtained by granulating the raw material powders of these materials) at a temperature lower than the melting points of these materials. Further, 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 to each other. 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. Further, the binder is a material such as an Al2O3 material and a glass material (that is, SiO d (0 < d ≤ 2)) and the like are used as known materials. Similarly, not limited to the binder, the sintered phosphor hardly requires materials other than the phosphor material and the oxide material not containing the luminescence center element that the sintered phosphor has (hereinafter referred to as other materials), and more specifically, does not require any other materials at all.

[0184] For example, when the total volume of the sintered phosphor is 100 vol%, the total volume of the phosphor material and the oxide material not containing the luminescent center element in the total volume of the sintered phosphor is preferably 70 vol% or more. In addition, the total volume of the phosphor material and the oxide material not containing the luminescent center element in the total volume of the sintered phosphor is more preferably 80 vol% or more, even more preferably 90 vol% or more, and even more preferably 95 vol% or more.

[0185] In other words, when the total volume of the sintered phosphor is 100vol%, the volume of other materials (for example, binder) in the total volume of the sintered phosphor is preferably less than 30vol%. Also, the volume of other materials (for example, binder) in the total volume of the sintered phosphor is more preferably 20vol% or less, even more preferably 10vol% or less, and even more preferably 5vol% or less.

[0186] Fluorescent structure 11d, which is made of a phosphor material, receives light incident from the negative z-axis direction of phosphor substrate 10d as excitation light L1 and emits fluorescence. More specifically, light emitted from light emitting unit 200 is irradiated as excitation light L1 onto the phosphor material constituting fluorescent structure 11d, causing fluorescent structure 11d to emit fluorescence as wavelength-converted light. In other words, the wavelength-converted light emitted from fluorescent structure 11d is light with a longer wavelength than the wavelength of excitation light L1.

[0187] The phosphor material according to this embodiment is YAG:Ce, as in the first and second embodiments, but may be any of the other phosphor materials described above. That is, the fluorescent structure 11d according to this embodiment is made of YAG:Ce.

[0188] In this embodiment, the wavelength-converted light emitted from the phosphor material (YAG:Ce) constituting the fluorescent structure 11d 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:Ce 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.

[0189] In the above-described first and second embodiments, the transmitted light L2 includes fluorescent light, which is wavelength-converted yellow light, and excitation light L1, which is wavelength-unconverted blue light, and is a composite of these lights, which is white light.

[0190] However, in the present embodiment, all of the excitation light L1 incident on the fluorescent structure 11d is wavelength-converted by the phosphor material and then transmitted through the fluorescent structure 11d. Therefore, the transmitted light L3 that has passed through the fluorescent structure 11d contains only wavelength-converted light. In other words, the transmitted light L3 is yellow light.

[0191] An example of an oxide material that does not contain a luminescent center element is aluminum oxide (Al2O3), which is a non-luminescent material obtained by removing the luminescent center element from the above-mentioned phosphor material. Note that Al2O3 used as the oxide material that does not contain a luminescent center element is different from the above-mentioned binder. Furthermore, the oxide material that does not contain a luminescent center element is a material with high transmittance in the wavelength region of the excitation light L1.

[0192] In this embodiment, the phosphor material is made of YAG:Ce, and the luminescent center element is, for example, Ce. Therefore, the non-luminescent material obtained by removing the luminescent center element from the phosphor material used in this embodiment is Y3Al5O 12 (i.e., YAG). As described above, the oxide structure 13d according to the present embodiment is made of Y3Al5O 12 (i.e. YAG).

[0193] Y3Al5O 12 The oxide structure 13d configured as above transmits excitation light L1, which is light incident on the phosphor substrate 10d from the negative direction of the z axis. Unlike the phosphor structure 11d, the oxide structure 13d does not convert the wavelength of the excitation light L1. The transmittance of the oxide structure 13d in the wavelength region of the excitation light L1 is sufficient to be 50% or more, preferably 70% or more, even more preferably 80% or more, and even more preferably 90% or more. In other words, the wavelength region of the excitation light L1 remains unchanged before and after passing through the oxide structure 13d, and in this case, the excitation light L1 is blue light.

[0194] Furthermore, phosphor substrate 10d according to this embodiment has a third region 23 and a fourth region 24. That is, phosphor substrate 10d according to this embodiment is segmented into third region 23 and fourth region 24. More specifically, in plan view, phosphor substrate 10d has third region 23 and a plurality of fourth regions 24. Note that in FIG. 11 , third region 23 is indicated by a dot, and in FIG. 12 , third region 23 is indicated by a dashed line, and the plurality of fourth regions 24 are indicated by a rectangular region surrounded by a dashed double-dashed line.

[0195] The third region 23 has the same shape as the first region 21 according to embodiment 2, and the fourth region 24 has the same shape as the second region 22 according to embodiment 2. However, as described above, the phosphor substrate 10d does not include a highly thermally conductive material.

[0196] 11, when the phosphor substrate 10d is viewed from above, the third region 23 has an annular shape, and the center of the annular shape coincides with the center point C1 of the phosphor substrate 10d. The third region 23 is provided in a circular ring shape on a circumference that is equidistant from the center point C1 of the phosphor substrate 10d. That is, the third region 23 is provided in a band shape along the circumferential direction in a planar view. The excitation light L1 emitted by the light emitting unit 200 is incident on the third region 23. More specifically, as shown in FIG. 11, in this embodiment, the excitation light L1 is irradiated at a position of radius R from the center point C1 of the phosphor substrate 10d.

[0197] Furthermore, when the phosphor substrate 10d is viewed in plan, the oxide structure 13d (i.e., the first light-transmitting region) is provided in the third region 23. More specifically, when the phosphor substrate 10d is viewed in plan, a part of the oxide structure 13d and a part of the fluorescent structure 11d are provided in the third region 23. Note that in Fig. 11, among the dots indicating the third region 23, the third region 23 indicated by lighter dots is provided with a part of the oxide structure 13d, and the third region 23 indicated by darker dots is provided with a part of the fluorescent structure 11d.

[0198] Of the excitation light L1 incident on the third region 23, the excitation light L1 incident on the oxide structure 13d is transmitted through the oxide structure 13d. Furthermore, of the excitation light L1 incident on the third region 23, the excitation light L1 incident on the fluorescent structure 11d is wavelength-converted by the fluorescent structure 11d and is emitted as transmitted light L3, which is wavelength-converted light.

[0199] Furthermore, when the phosphor substrate 10d is viewed from above, the multiple fourth regions 24 are provided on the inside and outside of the annular shape that is the shape of the third region 23. Of the multiple fourth regions 24, the fourth region 24 provided on the inside will be referred to as the "inner fourth region 24," and the fourth region 24 provided on the outside will be referred to as the "outer fourth region 24."

[0200] The inner fourth region 24 has a disk shape, and the center of the disk shape overlaps with the center point C1 of the phosphor substrate 10d. The inner fourth region 24 is in contact with the inner surface of the third region 23. The outer fourth region 24 has a circular ring shape like the third region 23, and the center of the circular ring shape overlaps with the center point C1 of the phosphor substrate 10d. The outer fourth region 24 is in contact with the outer surface of the third region 23. In other words, the third region 23 is sandwiched between the inner fourth region 24 and the outer fourth region 24.

[0201] In this embodiment, the sintered phosphor further includes an oxide material that does not include a luminescent center element. The phosphor substrate 10d is composed of only the oxide material of the phosphor material and the oxide material, and has a first light transmission region that transmits light (excitation light L1) that excites the phosphor material.

[0202] As a result, when excitation light L1 is incident on the first light-transmitting region (i.e., oxide structure 13d) made of an oxide material not containing a luminescent center element, the excitation light L1 passes through oxide structure 13d, and excitation light L1 is emitted from phosphor substrate 10d. Similarly, when excitation light L1 is incident on fluorescent structure 11d made of a fluorescent material, the excitation light L1 is wavelength-converted by fluorescent structure 11d, and transmitted light L3, which is wavelength-converted light, is emitted from phosphor substrate 10d.

[0203] Therefore, by rotating the rotating part, the phosphor substrate 10d can emit the excitation light L1 and the wavelength-converted light in a time-division manner. In this embodiment, the phosphor substrate 10d can emit yellow light as the excitation light L1 and blue light as the wavelength-converted light in a time-division manner.

[0204] Furthermore, fluorescence-emitting module 1d according to the present embodiment may be applied to projector 500 in place of fluorescence-emitting module 1c according to embodiment 1. In this case, projector 500 includes a DLP as display element section 602, that is, it can be used as a 1-DLP (one-chip DLP) type projector.

[0205] In this embodiment, the oxide material is aluminum oxide or a non-luminescent material obtained by removing the luminescent center element from a phosphor material.

[0206] These materials have high light transmittance for the excitation light L1 (i.e., light that excites the phosphor material). Therefore, the transmittance of the excitation light L1 in the first light-transmitting region (oxide structure 13d) is high, and loss of the excitation light L1 due to absorption is suppressed. Therefore, a fluorescence-emitting module 1d with high light utilization efficiency can be realized.

[0207] In addition, in the present embodiment, when the phosphor substrate 10d is viewed from above, the phosphor substrate 10d has a third region 23 having an annular shape, the center of the annular shape overlaps with the center (center point C1) of the phosphor substrate 10d, and a first light transmitting region is provided in the third region 23. Furthermore, in the present embodiment, the third region 23 is also provided with a fluorescent structure 11d.

[0208] Since the third region 23 has the above-mentioned shape, when excitation light L1 is incident on the third region 23, it becomes easier to use the phosphor substrate 10d, which can emit excitation light L1 and wavelength-converted light in a time-division manner, as a phosphor wheel.

[0209] In this embodiment, the fluorescence light-emitting module 1d further includes a light emitting section 200 that emits excitation light L1 that excites the phosphor material and enters the third region .

[0210] In this way, the excitation light L1 is incident on the third region 23 in which the fluorescent structure 11d and the oxide structure 13d are provided, so that the fluorescent substrate 10d can more easily emit the excitation light L1 and the wavelength-converted light in a time-division manner.

[0211] In the present embodiment, two oxide structures 13d are provided, but the present invention is not limited to this. For example, one oxide structure 13d may be provided, or three or more oxide structures 13d may be provided.

[0212] In another example of this embodiment, the phosphor material is (Y 1-x Ce x )3AlO 12 When the phosphor is made of a material other than (0.0001≦x<0.1), it is preferable to use a non-luminescent material in which the luminescent center element is removed from the phosphor. 1-y Ce y )3Al2Al3O 12(0.001≦y<0.1), the non-luminescent material obtained by removing the luminescent center element from the phosphor material is Lu3Al5O 12 It is preferable that the information be composed of the following:

[0213] [Manufacturing method] Here, a method for manufacturing the phosphor substrate 10d will be briefly described.

[0214] The phosphor material is (Y 0.999 Ce 0.001 )3AlO 12 The phosphor materials are all composed of a crystalline phase expressed by Ce. 3+ It is composed of activated phosphor.

[0215] To manufacture the phosphor substrate 10d, the following three types of compound powder were used as raw materials. Specifically, the raw materials were Y2O3, Al2O3, and CeO2. The purity and manufacturers of the respective materials were: Y2O3, 3N purity, from Nippon Yttrium Co., Ltd.; Al2O3, 3N purity, from Sumitomo Chemical Co., Ltd.; and CeO2, 3N purity, from Nippon Yttrium Co., Ltd.

[0216] Here, two types of mixed raw materials are used. The two types of mixed raw materials are a first mixed raw material containing CeO2 and a third mixed raw material not containing CeO2. Note that, since the first mixed raw material according to this embodiment is the same as the first mixed raw material according to embodiment 2, the steps up to the granulation of the first mixed raw material will be omitted.

[0217] First, let us consider the third mixed raw material. The compound Y3Al5O with a stoichiometric composition 12 As the raw materials, Y2O3 and Al2O3 were weighed out so that the ratio of the mixed raw material to the total weight of the raw materials was 1000. Next, the weighed Y2O3 and Al2O3 and alumina balls (diameter 10 mm) were placed in a plastic pot. The following procedure was followed in the same manner as for the first mixed raw material, and the third mixed raw material was granulated.

[0218] Next, molding of the first mixed raw material and the third mixed raw material will be described.

[0219] In the manufacturing method according to the present embodiment, a cylindrical mold with a partition provided inside is used, as in the second embodiment. Here, the mold is divided into three regions by two partitions. The first mixed raw material is placed in one of the three regions, and the third mixed raw material is placed in the other two of the three regions. When the cylindrical bottom surface of the mold is viewed from above, the two regions in which the third mixed raw material is placed are each annular sector, and the shape of the one region in which the first mixed raw material is placed is a circle with two annular sectors removed. In other words, two partitions are provided so that the first mixed raw material placed in one region corresponds to the fluorescent structure 11d, and the third mixed raw material placed in the other two regions correspond to two oxide structures 13d.

[0220] Except for the shape of the mold, the phosphor substrate 10d is manufactured by carrying out the same processes as in the first and second embodiments.

[0221] (Fourth embodiment) [Fluorescence module configuration] Next, a fluorescence light emitting module 1f according to the fourth embodiment will be described with reference to Fig. 13. Fig. 13 is a perspective view of the fluorescence light emitting module 1f according to the present embodiment.

[0222] The fluorescence-emitting module 1f is a module including a phosphor substrate 10f made of a sintered phosphor, an anti-reflection layer 30, a blue-transmitting dichroic multilayer film 40, a rotating unit (not shown), and two light-emitting units 200. For simplicity, only one light-emitting unit 200 is shown in FIG. 13. The rotating unit according to this embodiment has the same configuration as the rotating unit 100 described above. The light-emitting unit 200 also emits excitation light L1, as described above.

[0223] The fluorescence-emitting module 1f according to the present embodiment is different from the fluorescence-emitting module 1d according to embodiment 3 mainly in that the phosphor substrate 10f has a second light-transmitting region 14f instead of the first light-transmitting region (oxide structure 13d). In other words, the fluorescent sintered body according to the present embodiment contains only a phosphor material and does not contain an oxide material that does not contain a luminescent center element.

[0224] The phosphor substrate 10f according to this embodiment is a substrate made of a sintered phosphor having a phosphor material. The phosphor substrate 10f according to this embodiment is a substrate having two second light transmitting regions 14f, a third region 23, and a fourth region 24. Phosphor substrate 10f is configured by the fluorescent structure 11d shown in the third embodiment.

[0225] The second light-transmitting region 14f is an opening in the phosphor substrate 10f. That is, the second light-transmitting region 14f is configured by at least one of a through-hole penetrating the phosphor substrate 10f in the thickness direction (z-axis direction) of the phosphor substrate 10f and a cutout portion cut out from the phosphor substrate 10f. Here, the second light-transmitting region 14f corresponds to the cutout portion. The second light-transmitting region 14f has the same shape as the oxide structure 13d (first light-transmitting region) shown in the third embodiment, but is not limited to this.

[0226] Here, the sintered phosphor according to the present embodiment will be described.

[0227] The sintered phosphor is a fired body obtained by firing the raw material powder of the phosphor material (for example, granules obtained by granulating the raw material powder of the phosphor material), which is the main component, at a temperature lower than the melting point of the phosphor material. That is, the sintered phosphor according to the present embodiment is the same as the sintered phosphor according to the first embodiment.

[0228] As described in the third embodiment, when the excitation light L1 is incident on the fluorescent structure 11d, the fluorescent structure 11d emits wavelength-converted light (yellow light) having a wavelength longer than that of the excitation light L1 as transmitted light L3.

[0229] When the excitation light L1 is incident on the second light transmitting region 14f, the second light transmitting region 14f transmits the excitation light L1, which is blue light.

[0230] Furthermore, the phosphor substrate 10f according to this embodiment has segmented third regions 23 and fourth regions 24. More specifically, in plan view, the phosphor substrate 10f has the third region 23 and a plurality of fourth regions 24. In Fig. 13, the third region 23 is indicated by a dot.

[0231] The excitation light L1 emitted by the light emitting portion 200 is incident on the third region 23. More specifically, as shown in Fig. 13, in this embodiment, the excitation light L1 is irradiated onto a position of radius R from the center point C1 of the phosphor substrate 10f.

[0232] Furthermore, when the phosphor substrate 10f is viewed in a plan view, the third region 23 is provided with a second light-transmitting region 14f. More specifically, when the phosphor substrate 10f is viewed in a plan view, a part of the second light-transmitting region 14f and a part of the fluorescent structure 11d are provided in the third region 23. Note that in Fig. 13, among the dots indicating the third region 23, a part of the second light-transmitting region 14f is provided in the third region 23 indicated by a lighter dot, and a part of the fluorescent structure 11d is provided in the third region 23 indicated by a darker dot.

[0233] In this embodiment, the phosphor substrate 10f has a second light-transmitting region 14f that transmits light (excitation light L1) that excites the phosphor material. The second light-transmitting region 14f is configured by at least one of a through-hole that penetrates the phosphor substrate 10f in the thickness direction of the phosphor substrate 10f and a notch formed by cutting out the phosphor substrate 10f.

[0234] As a result, when excitation light L1 enters second light transmission region 14f, excitation light L1 is emitted from phosphor substrate 10f. Similarly, when excitation light L1 enters fluorescent structure 11d made of a fluorescent material, the excitation light L1 is wavelength-converted by fluorescent structure 11d, and transmitted light L3, which is wavelength-converted light, is emitted from phosphor substrate 10f.

[0235] Therefore, as the rotating part rotates, the phosphor substrate 10f can emit the excitation light L1 and the wavelength-converted light in a time-division manner. In this embodiment, the phosphor substrate 10f can emit yellow light as the excitation light L1 and blue light as the wavelength-converted light in a time-division manner.

[0236] Furthermore, fluorescence-emitting module 1f according to the present embodiment may be applied to projector 500 in place of fluorescence-emitting module 1c according to embodiment 1. In this case, projector 500 includes a DLP as display element section 602, that is, it can be used as a 1-DLP (one-chip DLP) type projector.

[0237] In this embodiment, when the phosphor substrate 10f is viewed in a plane, the phosphor substrate 10f has a third region 23 having a circular ring shape, the center of the circular ring shape overlaps with the center (center point C1) of the phosphor substrate 10f, and a second light-transmitting region 14f is provided in the third region 23.

[0238] Furthermore, in this embodiment, the third region 23 is also provided with a fluorescent structure 11d.

[0239] Since the third region 23 has the above-mentioned shape, when excitation light L1 is incident on the third region 23, it becomes easier to use the phosphor substrate 10f, which can emit excitation light L1 and wavelength-converted light in a time-division manner, as a phosphor wheel.

[0240] In this embodiment, the fluorescence light-emitting module 1f further includes a light emitting section 200 that emits excitation light L1 that excites the phosphor material and enters the third region .

[0241] In this way, by the excitation light L1 being incident on the third region 23 in which the fluorescent structure 11d and the second light-transmitting region 14f are provided, the fluorescent substrate 10f can more easily emit the excitation light L1 and the wavelength-converted light in a time-division manner.

[0242] [Manufacturing method] Here, a method for manufacturing the phosphor substrate 10f will be briefly described.

[0243] The phosphor material is (Y 0.999 Ce 0.001 )3AlO 12 The phosphor materials are all composed of a crystalline phase expressed by Ce. 3+ It is composed of activated phosphor.

[0244] To manufacture the phosphor substrate 10f, the first mixed raw material was granulated in the same manner as above.

[0245] Next, molding of the first mixed raw material will be described with reference to FIG.

[0246] FIG. 14 is a perspective view of a mold 400f for manufacturing a phosphor substrate 10f according to this embodiment.

[0247] The mold 400f is provided with an inner area A6 and two cutout areas A7.

[0248] The granulated first mixed raw material was pre-molded using an electric hydraulic press (EMP-5, manufactured by Riken Seiki Co., Ltd.) and a bottomed cylindrical mold 400. The first mixed raw material was placed in the inner region A6 of the mold 400f.

[0249] Next, the pre-molded body was subjected to final molding using a cold isostatic pressing device.

[0250] The molded body after the heat treatment was fired using a tubular atmosphere furnace.

[0251] The cylindrical fired product after firing was sliced ​​using a multi-wire saw. The sliced ​​fired product was then polished to adjust the thickness of the fired product. This adjustment resulted in the fired product becoming the phosphor substrate 10f.

[0252] The preliminary molding step, the main molding step, the firing step, the slicing step, and the polishing step are performed under the same conditions as those in the first embodiment.

[0253] By using the mold 400f provided with these two cutout regions A7, a phosphor substrate 10f having two second light transmission regions 14f is manufactured.

[0254] (Embodiment 5) Next, a fluorescence-emitting module 1g according to embodiment 5 will be described with reference to Fig. 15 and Fig. 16. Fig. 15 is a perspective view of fluorescence-emitting module 1g according to the present embodiment. Fig. 16 is a cross-sectional view showing a cut surface of part of fluorescence-emitting module 1g taken along line XVI-XVI in Fig. 15.

[0255] The fluorescence-emitting module 1g is a module including a phosphor substrate 10g made of a sintered phosphor, an antireflection layer 30, a blue-transmitting dichroic multilayer film 40, a rotating unit (not shown), and two light-emitting units 200. For simplicity, only one light-emitting unit 200 is shown in FIGS. 15 and 16. The rotating unit according to this embodiment has the same configuration as the rotating unit 100 described above. Furthermore, in FIG. 15, the axis A1 on the negative side of the z-axis from the blue-transmitting dichroic multilayer film 40 is not shown. The light-emitting unit 200 emits excitation light L1, as described above.

[0256] The fluorescence-emitting module 1g according to the present embodiment is mainly different from the fluorescence-emitting modules 1c, 1, 1d, and 1f according to the first, second, third, and fourth embodiments in the following respect: Specifically, the phosphor substrate 10g is composed of a sintered phosphor having a phosphor material, an oxide material not containing a luminescent center element, and a highly thermally conductive material.

[0257] The phosphor substrate 10g is a substrate composed of a sintered phosphor having a phosphor material, an oxide material not containing a luminescent center element, and a high thermal conductivity material, and is a substrate having a circular shape. That is, the phosphor substrate 10g has a disk shape with a flat surface. The phosphor substrate 10g is a substrate composed only of a sintered phosphor, and the sintered phosphor only has the phosphor material as a main component, the oxide material not containing a luminescent center element, and the high thermal conductivity material.

[0258] More specifically, as shown in Fig. 16, the phosphor substrate 10g is composed of a phosphor structure 11g, an oxide structure 13g, and a plurality of heat conductive structures 12. As shown in Figs. 15 and 16, the phosphor substrate 10g is provided with the phosphor structure 11g, two oxide structures 13g, and a plurality of heat conductive structures 12. That is, the phosphor substrate 10g is composed of the phosphor structure 11g, two oxide structures 13g, and a plurality of heat conductive structures 12, and the two oxide structures 13g have the same configuration. The two oxide structures 13g are the areas surrounded by dotted lines in Fig. 15.

[0259] The fluorescent structure 11g is a structure constituted by a fluorescent material contained in a sintered phosphor. More specifically, the fluorescent structure 11g is a structure constituted only by a fluorescent material contained in a sintered phosphor. The fluorescent structure 11g according to the present embodiment has the same configuration as the fluorescent structure 11d according to the third embodiment except for the shape.

[0260] The oxide structure 13g is a structure constituted by an oxide material that does not contain a luminescent center element contained in the sintered phosphor. More specifically, the oxide structure 13g is a structure constituted only by an oxide material that does not contain a luminescent center element contained in the sintered phosphor. The oxide structure 13g according to the present embodiment has the same configuration as the oxide structure 13d according to the third embodiment except for the shape. That is, the oxide structure 13g is an example of a first light transmission region of the phosphor substrate 10g.

[0261] As described above, the phosphor substrate 10g is a substrate having a circular shape. More specifically, the phosphor substrate 10g is a substrate having a circular shape formed by combining the phosphor structure 11g, two oxide structures 13g, and a plurality of heat conducting structures 12.

[0262] Here, the oxide structure 13g has an annular sector shape in plan view of the phosphor substrate 10g, that is, the oxide structure 13g has a shape surrounded by two arcs and two straight lines.

[0263] Here, as shown in Figure 15, when viewed in a plane of the phosphor substrate 10g, the two oxide structures 13g are arranged so that the outer arc (i.e., the arc farther from axis A1) of the two arcs representing the oxide structures 13g is closer to axis A1 than the circumference of the circular phosphor substrate 10g.

[0264] Furthermore, the shape of the combined fluorescent structure 11g and the plurality of heat conduction structures 12 is a circle with two annular sectorial openings in a plan view of the phosphor substrate 10g. That is, in the combined shape of the fluorescent structure 11g and the plurality of heat conduction structures 12, the oxide structure 13g is combined with the openings, so that the phosphor substrate 10g has a disk shape.

[0265] Furthermore, the plurality of heat conducting structures 12 are arranged on the phosphor substrate 10g so as to be surrounded by the fluorescent structure 11g. Although not shown, the plurality of heat conducting structures 12 may be arranged so that a portion of the plurality of heat conducting structures 12 protrudes from the fluorescent structure 11g. The fluorescent structure 11g serves as a base material for the plurality of heat conducting structures 12. In other words, the plurality of heat conducting structures 12 are embedded in the fluorescent structure 11g.

[0266] On the other hand, the plurality of heat conducting structures 12 are not disposed in the oxide structure 13g on the phosphor substrate 10g, and as shown in Fig. 16, the plurality of heat conducting structures 12 and the oxide structure 13g are not in contact with each other.

[0267] Here, the sintered phosphor in the present embodiment will be described.

[0268] The sintered phosphor is a fired body obtained by firing raw material powders of the phosphor material which is the above-described main component, an oxide material not containing a luminescent center element, and a high thermal conductivity material (as an example, a granulated body obtained by granulating raw material powders of these materials) at a temperature lower than the melting points of these materials. Further, 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 to each other. More specifically, the sintered phosphor does not require any binder at all. As an example, in Patent Document 1 described above, the binder is a transparent resin. Further, as the binder, an Al2O3 material and a glass material (that is, SiO d (0 < d ≤ 2)) and the like are used as known materials. Similarly, not limited to the binder, the sintered phosphor hardly requires materials other than the phosphor material, the oxide material not containing a luminescent center element, and the high thermal conductivity material that the sintered phosphor has (hereinafter referred to as other materials), and more specifically, does not require any other materials at all.

[0269] For example, when the total volume of the sintered phosphor is 100 vol%, the total volume of the phosphor material, the oxide material not containing a luminescent center element, and the high thermal conductivity material in the total volume of the sintered phosphor is preferably 70 vol% or more. Further, the total volume of the phosphor material, the oxide material not containing a luminescent center element, and the high thermal conductivity material in the total volume of the sintered phosphor is more preferably 80 vol% or more, even more preferably 90 vol% or more, and even more preferably 95 vol% or more.

[0270] In other words, when the total volume of the sintered phosphor is 100 vol%, the volume of other materials (for example, a binder) in the total volume of the sintered phosphor is preferably less than 30 vol%. Further, the volume of other materials (for example, a binder) in the total volume of the sintered phosphor is more preferably 20 vol% or less, even more preferably 10 vol% or less, and even more preferably 5 vol% or less.

[0271] Furthermore, the phosphor substrate 10g according to this embodiment has a first region 21 and a second region 22. That is, the phosphor substrate 10g according to this embodiment is segmented into the first region 21 and the second region 22. More specifically, in plan view, the phosphor substrate 10g has the first region 21 and a plurality of second regions 22. Note that, as shown in FIG. 5 16, the first region 21 is indicated by a dashed line, and the plurality of second regions 22 are rectangular regions surrounded by dashed double-dashed lines.

[0272] The first region 21 and the multiple second regions 22 have different amounts of highly thermally conductive material. The multiple second regions 22 have a higher amount of highly thermally conductive material than the first region 21. In other words, the first region 21 only needs to have a lower amount of highly thermally conductive material than the multiple second regions 22, and the first region 21 according to this embodiment does not contain a highly thermally conductive material. However, the first region 21 may contain a highly thermally conductive material. Furthermore, the excitation light L1 emitted by the light emitting unit 200 is incident on the first region 21. More specifically, as shown in FIG. 15 , in this embodiment, the excitation light L1 is irradiated at a position that is a radius R from the center point C1 of the phosphor substrate 10g.

[0273] Furthermore, when the phosphor substrate 10g is viewed in plan, an oxide structure 13g (i.e., a first light-transmitting region) is provided in the first region 21. More specifically, when the phosphor substrate 10g is viewed in plan, a part of the oxide structure 13g and a part of the fluorescent structure 11g are provided in the first region 21. Note that in Fig. 15, among the dots indicating the first region 21, a part of the oxide structure 13g is provided in the first region 21 indicated by a lighter dot, and a part of the fluorescent structure 11g is provided in the first region 21 indicated by a darker dot.

[0274] Of the excitation light L1 incident on the first region 21, the excitation light L1 incident on the oxide structure 13g is transmitted through the oxide structure 13g. Furthermore, of the excitation light L1 incident on the first region 21, the excitation light L1 incident on the fluorescent structure 11g is wavelength-converted by the fluorescent structure 11g and is emitted as transmitted light L3, which is wavelength-converted light.

[0275] In this embodiment, the sintered phosphor further includes an oxide material that does not include a luminescent center element. The phosphor substrate 10g is composed of only the oxide material of the phosphor material and the oxide material, and has a first light-transmitting region that transmits light (excitation light L1) that excites the phosphor material. The first region 21 is provided with the first light-transmitting region.

[0276] As a result, when excitation light L1 is incident on the first light-transmitting region (i.e., oxide structure 13g) made of an oxide material not containing a luminescent center element, the excitation light L1 passes through the oxide structure 13g, and excitation light L1 is emitted from the phosphor substrate 10g. Similarly, when excitation light L1 is incident on fluorescent structure 11g made of a phosphor material, the excitation light L1 is wavelength-converted by fluorescent structure 11g, and transmitted light L3, which is wavelength-converted light, is emitted from the phosphor substrate 10g.

[0277] Therefore, by rotating the rotating part, the phosphor substrate 10g can emit the excitation light L1 and the wavelength-converted light in a time-division manner. In this embodiment, the phosphor substrate 10g can emit yellow light as the excitation light L1 and blue light as the wavelength-converted light in a time-division manner.

[0278] Furthermore, fluorescence-emitting module 1g according to the present embodiment may be applied to projector 500 in place of fluorescence-emitting module 1c according to embodiment 1. In this case, projector 500 includes a DLP as display element section 602, that is, it can be used as a 1-DLP (one-chip DLP) type projector.

[0279] In this embodiment, the oxide material is aluminum oxide or a non-luminescent material obtained by removing the luminescent center element from a phosphor material.

[0280] These materials have high light transmittance for the excitation light L1 (i.e., light that excites the phosphor material). Therefore, the transmittance of the excitation light L1 in the first light-transmitting region (oxide structure 13g) is high, and loss of the excitation light L1 due to absorption is suppressed. Therefore, a fluorescence-emitting module 1g with high light utilization efficiency can be realized.

[0281] (Sixth embodiment) Next, a fluorescence light-emitting module 1h according to the sixth embodiment will be described with reference to Fig. 17. Fig. 17 is a perspective view of the fluorescence light-emitting module 1h according to the present embodiment.

[0282] The fluorescence-emitting module 1h is a module including a phosphor substrate 10h made of a sintered phosphor, an antireflection layer 30, a blue-transmitting dichroic multilayer film 40, a rotating unit (not shown), and two light-emitting units 200. For simplicity, only one light-emitting unit 200 is shown in FIG. 17. The rotating unit according to this embodiment has the same configuration as the rotating unit 100 described above. The light-emitting unit 200 also emits excitation light L1, as described above.

[0283] The fluorescent light-emitting module 1h according to the present embodiment is different from the fluorescent light-emitting module 1g according to embodiment 5 mainly in that the phosphor substrate 10h has a second light-transmitting region 14h instead of the first light-transmitting region (oxide structure 13g). In other words, the fluorescent sintered body according to the present embodiment contains only a phosphor material and a high thermal conductivity material, and does not contain an oxide material that does not contain a luminescent center element.

[0284] That is, the phosphor substrate 10h according to the present embodiment is a substrate constituted by a sintered phosphor having a phosphor material. Also, the phosphor substrate 10h according to the present embodiment is a substrate having two second light transmitting regions 14h, a first region 21, and a second region 22. The sintered phosphor according to the present embodiment is constituted by the phosphor structure 11g shown in the fifth embodiment.

[0285] The second light-transmitting region 14h is an opening in the phosphor substrate 10h. That is, the second light-transmitting region 14h is configured by at least one of a through-hole penetrating the phosphor substrate 10h in the thickness direction (z-axis direction) of the phosphor substrate 10h and a cutout portion cut out of the phosphor substrate 10h. Here, the second light-transmitting region 14h corresponds to the cutout portion. The second light-transmitting region 14h according to the present embodiment has the same configuration as the second light-transmitting region 14f according to embodiment 4, except for the shape. The second light-transmitting region 14h has the same shape as the oxide structure 13g (first light-transmitting region) shown in embodiment 5, but is not limited to this.

[0286] Here, the sintered phosphor according to the present embodiment will be described.

[0287] The sintered phosphor is a fired body obtained by firing raw material powders of the phosphor material and the high thermal conductivity material (for example, granules obtained by granulating the raw material powders of these materials) which are the main components described above at a temperature lower than the melting points of these materials. That is, the sintered phosphor according to the present embodiment is the same as the sintered phosphor according to the second embodiment.

[0288] As described in the fifth embodiment, when the excitation light L1 is incident on the fluorescent structure 11g, the fluorescent structure 11g emits wavelength-converted light (yellow light) having a wavelength longer than that of the excitation light L1 as transmitted light L3.

[0289] When the excitation light L1 is incident on the second light transmitting region 14h, the excitation light L1, which is blue light, is transmitted through the second light transmitting region 14h.

[0290] Furthermore, the phosphor substrate 10h according to this embodiment has segmented first regions 21 and second regions 22. More specifically, in plan view, the phosphor substrate 10h has the first region 21 and a plurality of second regions 22. In Fig. 17, the first regions 21 are indicated by dots.

[0291] The excitation light L1 emitted by the light emitting portion 200 is incident on the first region 21. More specifically, as shown in Fig. 17, in this embodiment, the excitation light L1 is irradiated onto a position of radius R from the center point C1 of the phosphor substrate 10h.

[0292] Furthermore, when the phosphor substrate 10h is viewed in a plan view, the first region 21 is provided with a second light-transmitting region 14h. More specifically, when the phosphor substrate 10h is viewed in a plan view, a part of the second light-transmitting region 14h and a part of the fluorescent structure 11g are provided in the first region 21. Note that in Fig. 17, among the dots indicating the first region 21, a part of the second light-transmitting region 14h is provided in the first region 21 indicated by a lighter dot, and a part of the fluorescent structure 11g is provided in the first region 21 indicated by a darker dot.

[0293] The phosphor substrate 10h has a second light-transmitting region 14h that transmits light (excitation light L1) that excites the phosphor material. The second light-transmitting region 14h is configured by at least one of a through-hole that penetrates the phosphor substrate 10h in the thickness direction of the phosphor substrate 10h and a notch formed by cutting out the phosphor substrate 10h. The second light-transmitting region 14h is provided in the first region 21.

[0294] As a result, when excitation light L1 enters second light transmission region 14h, excitation light L1 is emitted from phosphor substrate 10h. Similarly, when excitation light L1 enters fluorescent structure 11g made of a fluorescent material, the excitation light L1 is wavelength-converted by fluorescent structure 11g, and transmitted light L3, which is wavelength-converted light, is emitted from phosphor substrate 10h.

[0295] Therefore, as the rotating part rotates, the phosphor substrate 10h can emit the excitation light L1 and the wavelength-converted light in a time-division manner. In this embodiment, the phosphor substrate 10h can emit yellow light as the excitation light L1 and blue light as the wavelength-converted light in a time-division manner.

[0296] Furthermore, fluorescence-emitting module 1h according to the present embodiment may be applied to projector 500 in place of fluorescence-emitting module 1c according to embodiment 1. In this case, projector 500 includes a DLP as display element section 602, that is, it can be used as a 1-DLP (one-chip DLP) type projector.

[0297] (Other embodiments) While the fluorescence-emitting module and the like according to the present invention have been described above based on various embodiments, the present invention is not limited to these embodiments. As long as they do not deviate from the gist of the present invention, various modifications that would occur to those skilled in the art to the embodiments and other forms constructed by combining some of the components of the various embodiments are also included within the scope of the present invention.

[0298] The fluorescence light-emitting modules 1 and 1c include the phosphor substrates 10 and 10c, the anti-reflection layer 30, the blue-transmitting dichroic multilayer film 40, the rotating section 100, and the light-emitting section 200, but are not limited to this.

[0299] The fluorescence-emitting module 1c simply includes a phosphor substrate 10c and a rotating unit 100. Unlike Patent Document 1, reflection of the excitation light L1 at the interface between the phosphor substrate and the atmosphere does not occur. Therefore, the excitation light L1 incident on the phosphor substrate 10c increases. As a result, the fluorescence generated by the phosphor material in the phosphor substrate 10c increases. Furthermore, because the fluorescence-emitting module 1c does not include components for supporting the phosphor substrate 10c, the peeling of the fluorescence generating unit disclosed in Patent Document 1 does not occur. Furthermore, airflow is generated by the rotation of the rotating unit 100. This generated airflow suppresses the temperature rise of the phosphor substrate 10c, thereby suppressing the decrease in fluorescence. In other words, the light utilization efficiency of the fluorescence-emitting module 1c can be improved. Furthermore, suppressing the decrease in fluorescence suppresses the chromaticity change of the transmitted light L2, and the aforementioned peeling does not occur. This results in a highly reliable fluorescence-emitting module 1c.

[0300] Similarly, the fluorescence-emitting module 1 may include a phosphor substrate 10, which is a substrate composed of a sintered phosphor containing a phosphor material and a highly thermally conductive material. Unlike Patent Document 1, reflection of the excitation light L1 generated at the interface between the phosphor substrate and the atmosphere does not occur. Therefore, 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. Furthermore, because the fluorescence-emitting module 1 does not include components for supporting the phosphor substrate 10, the peeling of the fluorescence generating unit disclosed in Patent Document 1 does not occur. Furthermore, since the sintered phosphor constituting the phosphor substrate 10 contains a highly thermally conductive material, the heat dissipation of the phosphor substrate 10 is improved. This suppresses the temperature rise of the phosphor substrate 10 due to irradiation with the excitation light L1, thereby suppressing the decrease in fluorescence. In other words, a fluorescence-emitting module 1 with high light utilization efficiency can be realized. Furthermore, suppressing the decrease in fluorescence suppresses the chromaticity change of the transmitted light L2, and the above-mentioned peeling does not occur. Therefore, a highly reliable fluorescence-emitting module 1 is realized.

[0301] <Shape of heat conduction structure> In the second embodiment, each of the heat conducting structures 12 has a particle shape, but may have a wire shape, a sheet shape, or a mesh shape as other examples. These other examples will now be described.

[0302] <Mesh shape> Fig. 6 is a cross-sectional view of a phosphor substrate 10a according to Alternative Example 1 of Embodiment 2. Fig. 7 is a cross-sectional view of a phosphor substrate 10b according to Alternative Example 2 of Embodiment 2. Note that Figs. 6 and 7 correspond to the cross-sectional view of Fig. 2, and components such as the anti-reflection layer 30, the blue-transmitting dichroic multilayer film 40, the rotating unit 100, and the light emitting unit 200 are omitted from Figs. 6 and 7.

[0303] As shown in FIG. 6, when each of the heat conducting structures 12a has a wire shape, the wire diameter is, for example, 1 μm to 50 μm and the length is, for example, but not limited to, 10 μm to 500 μm.

[0304] <Sheet shape> 7 shows an example in which each of the plurality of heat conducting structures 12b has a sheet shape. In this case, the fluorescent structure 11 and the plurality of heat conducting structures 12b are stacked. In the inner second region 22, the plurality of heat conducting structures 12b have a circular shape, and in the outer second region 22, the plurality of heat conducting structures 12b have an annular shape.

[0305] Furthermore, although not shown, when each of the plurality of heat conducting structures has a sheet shape, a plurality of through holes may be provided penetrating the sheet shape in the thickness direction. In this case, each of the plurality of heat conducting structures has a mesh shape. In other words, the plurality of meshes in the mesh shape correspond to the plurality of through holes.

[0306] When the plurality of heat conducting structures 12 have these shapes, the heat dissipation properties of the phosphor substrates 10a and 10b can be further improved.

[0307] Furthermore, when the plurality of heat conducting structures each have a mesh shape, it is preferable that the plurality of heat conducting structures be included in the first region 21. In this case, it is preferable that the plurality of heat conducting structures be provided across the first region 21 and the plurality of second regions 22. This can increase the structural strength of the phosphor substrate 10b and suppress cracking of the phosphor substrate 10b.

[0308] However, as described above, it is preferable that the first region 21 does not contain a highly thermally conductive material. This increases the efficiency of wavelength conversion by the phosphor material. Therefore, it is preferable that the first region 21 contains a smaller amount of highly thermally conductive material than the plurality of second regions 22.

[0309] 11, the oxide structure 13d is arranged such that the circumference of the circular phosphor substrate 10d overlaps with the outer arc (i.e., the arc farther from the axis A1) of the two arcs representing the oxide structure 13d in a plan view of the phosphor substrate 10d. However, the present invention is not limited to this.

[0310] For example, an oxide structure 13d may be provided in the same shape and at the same position as the oxide structure 13g shown in FIG.

[0311] Furthermore, in the third to sixth embodiments, yellow light is emitted as the transmitted light L3, but this is not limiting. For example, the phosphor material may be a combination of the yellow phosphor material YAG:Ce and a green phosphor material. In this case, the phosphor substrate can emit yellow and green light as the excitation light L1, and blue light as the wavelength-converted light, in a time-division manner. Furthermore, for example, a red phosphor material may be used instead of the green phosphor material.

[0312] Furthermore, the above-described embodiments can be modified, replaced, added, omitted, and the like in various ways within the scope of the claims or their equivalents. [Explanation of symbols]

[0313] 1, 1c, 1d, 1f, 1g, 1h Fluorescence Emission Module 10, 10a, 10b, 10c, 10d, 10f, 10g, 10h light body substrate 14f, 14h Second light transmission area 21 First Area 22 Second Domain 23 The Third Domain 24 The 4th Domain 100 Chapter 100 200 light exit part C1 center point L1 light up L2, L3 transmitted light R Radius

Claims

1. A phosphor substrate which is a substrate constituted by a sintered phosphor having a phosphor material; a rotating unit that rotates the phosphor substrate around an axis extending in a thickness direction of the phosphor substrate, The sintered phosphor further includes a high thermal conductivity material having a thermal conductivity of 100 W / m K or more and 300 W / m K or less, the high thermal conductivity material is composed of a metal element, the highly thermally conductive material is in the form of particles, wires, sheets, or meshes; The high thermal conductivity material is surrounded by the phosphor material. Fluorescence emission module.

2. A phosphor substrate is a substrate made of a sintered phosphor having a phosphor material and a high thermal conductivity material having a thermal conductivity of 100 W / m K or more and 300 W / m K or less, the high thermal conductivity material is composed of a metal element, the highly thermally conductive material is in the form of particles, wires, sheets, or meshes; The high thermal conductivity material is surrounded by the phosphor material. Fluorescence emission module.

3. The linear expansion coefficient of the high thermal conductive material is 1 × 10 －７ / K or less 3. The fluorescent light-emitting module according to claim 1.

4. The high thermal conductivity material includes at least one of W, Mo, Rh, AlN, and SiC. The fluorescent light-emitting module according to any one of claims 1 to 3.

5. The melting point of the high thermal conductivity material at normal pressure is 1700°C or higher. The fluorescent light-emitting module according to any one of claims 1 to 4.

6. When the phosphor substrate is viewed in plan, The phosphor substrate is A first region; a second region having a higher content of the high thermal conductivity material than the first region; The fluorescent light-emitting module according to any one of claims 1 to 5.

7. When the phosphor substrate is viewed from above, the first region has a circular ring shape; The center of the annular shape overlaps with the center of the phosphor substrate. The fluorescent light-emitting module according to claim 6 .

8. The sintered phosphor further includes an oxide material that does not contain a luminescent center element, the phosphor substrate has a first light-transmitting region that is made of only the oxide material of the phosphor material and the oxide material and transmits light that excites the phosphor material; The first region is provided with the first light transmitting region. The fluorescent light-emitting module according to claim 7 .

9. The oxide material is aluminum oxide or a non-luminescent material obtained by removing the luminescent center element from the phosphor material.

9. The fluorescent light-emitting module according to claim 8.

10. the phosphor substrate has a second light-transmitting region that transmits light that excites the phosphor material; the second light transmitting region is configured by at least one of a through hole penetrating the phosphor substrate in a thickness direction of the phosphor substrate and a notch portion formed by cutting out the phosphor substrate, The first region is provided with the second light transmitting region. The fluorescent light-emitting module according to claim 7 .

11. When the phosphor substrate is viewed from above, the second region is provided inside and outside the annular shape. The fluorescent light-emitting module according to any one of claims 7 to 10.

12. a light emitting section that emits excitation light that excites the phosphor material and that is incident on the first region; The fluorescent light-emitting module according to any one of claims 6 to 11.

13. a part of the incident excitation light is wavelength-converted by the phosphor material contained in the first region and passes through the phosphor substrate; The other part of the incident excitation light is transmitted through the phosphor substrate without being wavelength-converted by the phosphor material contained in the first region.

13. The fluorescent light-emitting module according to claim 12.

14. The sintered phosphor further has an oxide material that does not contain a luminescent center element, The phosphor substrate is made of only the oxide material of the phosphor material and the oxide material, and has a first light-transmitting region that transmits light that excites the phosphor material. The fluorescent light-emitting module according to claim 1 .

15. The oxide material is aluminum oxide or a non-luminescent material obtained by removing the luminescent center element from the phosphor material.

15. The fluorescent light-emitting module according to claim 14.

16. When the phosphor substrate is viewed from above, the phosphor substrate has a third region having an annular shape; the center of the annular shape overlaps with the center of the phosphor substrate; The third region is provided with the first light transmitting region.

16. The fluorescent light-emitting module according to claim 14 or 15.

17. The phosphor substrate has a second light-transmitting region that transmits light that excites the phosphor material, The second light-transmitting region is configured by at least one of a through-hole penetrating the phosphor substrate in a thickness direction of the phosphor substrate and a notch formed by cutting out the phosphor substrate. The fluorescent light-emitting module according to claim 1 .

18. When the phosphor substrate is viewed from above, the phosphor substrate has a third region having an annular shape; the center of the annular shape overlaps with the center of the phosphor substrate; The third region is provided with the second light transmitting region.

18. The fluorescent light-emitting module of claim 17.

19. a light emitting section that emits excitation light that excites the phosphor material and that is incident on the third region; 19. The fluorescent light-emitting module according to claim 16 or 18.

20. The phosphor material is (Y １－ｘ Ce ｘ ) ３ Al ５ O １２ (0.0005≦x<0.001) The fluorescent light-emitting module according to any one of claims 1 to 19.

21. A fluorescent light-emitting module according to any one of claims 1 to 20 is provided. Light-emitting device.

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