JPWO2018198949A1 - Wavelength conversion element, light emitting device and lighting device - Google Patents

Abstract

The wavelength conversion element (1) includes a support member (2) having a support surface (2a) and a wavelength conversion member (40) disposed above the support surface (2a). , A radiation surface (6) located on the opposite side of the support surface (2a), and the radiation surface (6) includes a peripheral region (6a) including a periphery of the radiation surface (6) and a peripheral region (6a). At least a portion of the peripheral region (6a) has a first top (P1) projecting from the central region (6b) in a direction away from the support surface (2a); The radiation surface (6) has a first inclined portion (S1) that is inclined from the first top portion (P1) toward the center region (6b) toward the support surface (2a).

Description

  The present disclosure relates to a wavelength conversion element, and a light emitting device and a lighting device including the same.

  Conventionally, a light emitting device using an excitation light source and a wavelength conversion element has been proposed (for example, see Patent Document 1). As a light emitting device of this type, a light emitting device disclosed in Patent Document 1 will be described with reference to FIG. FIG. 25 is a schematic view of a conventional light emitting device.

  The light emitting device 1063 disclosed in Patent Document 1 includes an excitation light source 1070, an excitation light condensing lens 1139, a wavelength conversion element (phosphor wheel 1071) to which a phosphor layer 1131 is attached, and a light guide device 1075. Be composed.

  In the phosphor wheel 1071, the phosphor layer 1131 is attached to the base material 1130 via the reflection layer 1138. The base material 1130 is formed of a heat transfer member such as a copper plate, on which a reflective layer 1138 formed by silver deposition or the like is provided. The reflection layer 1138 reflects the excitation light and the light generated by the phosphor.

  Excitation light emitted from the excitation light source 1070 is condensed by the excitation light condensing lens, and is irradiated on the phosphor layer 1131. Then, the excitation light is absorbed by the phosphor in the phosphor layer 1131. Accordingly, the phosphor emits fluorescence. This fluorescence is guided to the light guide device 1075.

  At this time, it has been proposed to use a heat transfer member such as a copper plate as the base material 1130 to disperse the heat generated in the phosphor layer to the entire heat transfer member and effectively radiate the heat.

JP 2010-85740 A

  In the light emitting device 1063 disclosed in Patent Document 1, which emits excitation light to a phosphor layer to obtain emission light, in order to emit emission light with higher brightness, light with a high light density is applied to a wavelength conversion element. In this case, the temperature is locally increased in a region of the phosphor layer 1131 where the excitation light is irradiated. Such an increase in the temperature of the phosphor layer causes a sharp decrease in the conversion efficiency of the phosphor and damage to the wavelength conversion element.

  Therefore, an object of the present disclosure is to provide a wavelength conversion element capable of sufficiently converting excitation light into fluorescence and having increased mechanical strength, and a light emitting device and a lighting device including the wavelength conversion element.

  In order to solve the above problems, one embodiment of a wavelength conversion element according to the present disclosure includes a support member having a support surface, and a wavelength conversion member disposed above the support surface, wherein the wavelength conversion member is A radiating surface positioned opposite to the support surface, the radiating surface including a peripheral region including a periphery of the radiation surface, and a central region surrounded by the peripheral region, and at least a part of the peripheral region Has a first apex projecting from the central region in a direction away from the support surface, and the radiating surface is inclined toward the support surface from the first apex toward the central region. It has a slope.

  As described above, in the wavelength conversion element in which the wavelength conversion member is fixed on the support member, the linear expansion coefficients of the support member and the wavelength conversion member may be different. In such a case, the thickness of the wavelength conversion member is larger, the stress applied to the wavelength conversion member with the temperature change of the wavelength conversion element is reduced, and the wavelength conversion member can be prevented from peeling from the support member. .

  On the other hand, when the thickness of the wavelength conversion member is small, the temperature rise of the wavelength conversion member can be suppressed. Therefore, in the wavelength conversion element of the present disclosure, if the central region where the film thickness of the wavelength conversion member is thin is irradiated with the excitation light, the excitation light can be sufficiently converted into the fluorescent light by suppressing the temperature rise of the wavelength conversion member.

  In addition, by providing a peripheral portion where the thickness of the wavelength conversion member is thicker around the center region, the wavelength conversion member can be supported against changes in the environmental temperature of the wavelength conversion element and changes in temperature when the wavelength conversion element emits light. Peeling from the member can be suppressed. That is, in the wavelength conversion element according to the present embodiment, the mechanical strength can be increased.

  In one aspect of the wavelength conversion element according to the present disclosure, the central region may include a flat portion whose inclination is gentler than that of the first inclined portion.

  In one aspect of the wavelength conversion element according to the present disclosure, a plurality of minute projections may be formed on the radiation surface of the first inclined portion.

  In one aspect of the wavelength conversion element according to the present disclosure, an arrangement region of the support surface where the wavelength conversion member is arranged may be a flat surface.

  In one aspect of the wavelength conversion element according to the present disclosure, a film thickness of the wavelength conversion member at the first top may be larger than a film thickness of the central region.

  In one aspect of the wavelength conversion element according to the present disclosure, a film thickness of the wavelength conversion member in the central region may be 15 μm or more and 35 μm or less.

  In one aspect of the wavelength conversion element according to the present disclosure, the wavelength conversion member may include a plurality of first phosphor particles made of the same material in the central region and the first top.

  In one aspect of the wavelength conversion element according to the present disclosure, the wavelength conversion member may include a transparent binding material that binds the plurality of first phosphor particles.

  In one aspect of the wavelength conversion element according to the present disclosure, the wavelength conversion member may include a plurality of scattering particles bonded to the transparent bonding material.

  In one aspect of the wavelength conversion element according to the present disclosure, the total volume of the plurality of first phosphor particles may be 35% or more and 62% or less with respect to the volume of the wavelength conversion member.

  Further, in one aspect of the wavelength conversion element according to the present disclosure, in a cross section of the wavelength conversion member, a total cross-sectional area of the plurality of first phosphor particles is 40% or more with respect to a cross-sectional area of the wavelength conversion member. It may be 80% or less.

  In one aspect of the wavelength conversion element according to the present disclosure, the radiation surface of the first inclined portion is formed with a plurality of minute protrusions, and at least a part of the plurality of minute protrusions is A part of the plurality of first phosphor particles may be formed by projecting from the emission surface.

In one aspect of the wavelength conversion element according to the present disclosure, the wavelength conversion member includes second phosphor particles different from the plurality of first phosphor particles, and the plurality of first phosphor particles are Ce. There were activated _{(Y x Gd 1-x)} 3 (Al y Ga 1-y) 5 O 12 (0.5 ≦ x ≦ 1,0.5 ≦ y ≦ 1), or Ce have been activated (La _{1-x1, Y x1) 3} Si 6 N 11 comprises a (0 ≦ x1 ≦ 1), the second phosphor particles, Ce is activated _{(La 1-x2, Y x2} ) 3 Si 6 N 11 ( 0 ≦ x2 ≦ 1, x1 ≠ x2).

  Further, in one aspect of the wavelength conversion element according to the present disclosure, the peripheral region is disposed at a position opposite to the first apex with respect to the central region, and is positioned away from the support surface from the central region. The radiation surface may have a second inclined portion inclined toward the support surface from the second peak toward the central region.

  In one aspect of the wavelength conversion element according to the present disclosure, the height of the first apex from the support surface may be higher than the height of the second apex.

  Further, in one aspect of the wavelength conversion element according to the present disclosure, in a top view of the support surface, the wavelength conversion member has an elongated shape, and the first apex is disposed in a longitudinal direction of the wavelength conversion member. May be arranged at the end in the direction perpendicular to the direction.

  In one aspect of the wavelength conversion element according to the present disclosure, the wavelength conversion element may further include a reflection member disposed between the wavelength conversion member and the support member.

In one aspect of the wavelength conversion element according to the present disclosure, the support member may include silicon (Si), silicon carbide (SiC), sapphire (Al ₂ O ₃ ), aluminum nitride (AlN), or diamond.

One embodiment of the wavelength conversion element according to the present disclosure includes a support member having a support surface, and a wavelength conversion member disposed above the support surface, wherein the wavelength conversion member generates the first fluorescence. A plurality of first phosphor particles, a plurality of second phosphor particles generating second fluorescence having a spectrum different from the first fluorescence, the plurality of first phosphor particles, and the plurality of second phosphor particles; A plurality of first phosphor particles and a plurality of scattering particles different from the plurality of second phosphor particles, the plurality of first phosphor particles and the plurality of second phosphor particles. The body particles include (La _1-x1 , Y _x1 ) ₃ Si ₆ N ₁₁ (0 ≦ x1 ≦ 1) with Ce activated, and the plurality of second phosphor particles have Ce activated (La). _{1-x2, Y x2) 3} Si 6 N 11 (0 ≦ x2 ≦ 1, x1 ≠ x ) Including the.

  As described above, since the wavelength conversion member includes the first phosphor particles and the second phosphor particles that emit fluorescence having mutually different spectra, by adjusting the mixing ratio of each particle, the emission light can be more freely emitted. The chromaticity coordinates can be adjusted.

  In one aspect of the wavelength conversion element according to the present disclosure, the scattering particles may include a metal oxide or a nitride.

  In one aspect of the wavelength conversion element according to the present disclosure, a median diameter of the plurality of first phosphor particles and the plurality of second phosphor particles may be 2 μm or more and 30 μm or less.

  Further, in one aspect of the wavelength conversion element according to the present disclosure, a median diameter of the plurality of first phosphor particles and the plurality of second phosphor particles may be 3 μm or more and 9 μm or less.

One embodiment of a light-emitting device according to the present disclosure is a light-emitting device including the wavelength conversion element and an excitation light source that irradiates the wavelength conversion element with excitation light. 1000 cd / mm ² or more.

  One embodiment of a light emitting device according to the present disclosure is a light emitting device including the wavelength conversion element and an excitation light source that irradiates the wavelength conversion element with excitation light, wherein the excitation light is on the second top side. And enters the radiation surface obliquely, and the wavelength conversion member converts the wavelength of the excitation light.

  Further, one aspect of the lighting device according to the present disclosure may include the light emitting device, and a light projecting member that receives light emitted from the light emitting device and emits projection light.

  In one aspect of the lighting device according to the present disclosure, the excitation light includes a straight line orthogonal to an optical axis of the excitation light at a position where the excitation light is incident on the wavelength conversion member, and includes a straight line parallel to the support surface, With respect to a plane perpendicular to the support surface, the projection light may be emitted toward the excitation light source from the plane.

  According to the present disclosure, it is possible to provide a wavelength conversion element capable of sufficiently converting excitation light into fluorescence and having increased mechanical strength, and a light emitting device and a lighting device including the wavelength conversion element.

FIG. 1 is a schematic cross-sectional view illustrating a configuration of the wavelength conversion element according to the first embodiment. FIG. 2 is a diagram illustrating a shape of the support surface of the wavelength conversion element according to the first embodiment when viewed from above. FIG. 3 is a photograph of a cross section of the wavelength conversion element according to the first embodiment observed with a scanning electron microscope. FIG. 4 is a schematic cross-sectional view illustrating a configuration of the lighting device according to Embodiment 1. FIG. 5 is an enlarged view near the wavelength conversion element of the light emitting device according to the first embodiment. FIG. 6 is a diagram illustrating optical characteristics of the wavelength conversion element according to the first embodiment. FIG. 7 is a graph showing a measurement result of luminance of light emitted from the wavelength conversion member according to the first embodiment. FIG. 8 is a graph showing measurement results of respective surface shapes when the wavelength conversion member of the wavelength conversion element according to Embodiment 1 is manufactured by three different methods. FIG. 9 is a schematic cross-sectional view illustrating a configuration of a wavelength conversion element according to a first modification of the first embodiment. FIG. 10 is a schematic diagram illustrating a configuration of a light emitting device and a lighting device according to a second modification of the first embodiment. FIG. 11 is a top view illustrating a configuration of a wavelength conversion element according to a second modification of the first embodiment. FIG. 12 is a schematic cross-sectional view illustrating a configuration of the wavelength conversion element according to the second embodiment. FIG. 13 is a photograph obtained by observing a cross section of the wavelength conversion element according to Embodiment 2 with a scanning electron microscope. FIG. 14 is a graph showing a spectrum of emitted light when the wavelength conversion element according to Embodiment 2 is irradiated with excitation light having a peak wavelength of 447 nm. FIG. 15 is a graph showing changes in chromaticity coordinates of emitted light when the ratio between the first phosphor particles and the scattering particles is changed in the wavelength conversion element according to the second embodiment. FIG. 16 is a graph showing the results of measuring the peak wavelength dependence of the excitation light on the chromaticity coordinates of the emitted light in the wavelength conversion element according to the second embodiment. FIG. 17 is a diagram showing the refractive index and the thermal conductivity of a material that can constitute the wavelength conversion member. FIG. 18 shows the temperature of the quantum efficiency between the La ₃ Si ₆ N ₁₁ : Ce phosphor used in the wavelength conversion member according to the _third embodiment and the Y ₃ Al ₅ O ₁₂ : Ce phosphor used in the first embodiment. It is a figure which shows dependency. FIG. 19 is a diagram illustrating characteristics of a light emitting device equipped with the wavelength conversion element according to the third embodiment. FIG. 20 is a graph showing the results of measuring the luminance distribution of the light emitting region on the phosphor surface when the driving current of the semiconductor light emitting device of the light emitting device according to Embodiment 3 is 2.3 amps. FIG. 21 is a schematic sectional view showing the configuration of the wavelength conversion element according to the fourth embodiment. FIG. 22 is a graph showing the spectral characteristics of the emitted light of the light emitting device using the wavelength conversion element according to the fourth embodiment. FIG. 23 is a diagram illustrating a change in chromaticity coordinates of emitted light when the configuration of the wavelength conversion element is changed in the light emitting device equipped with the wavelength conversion element according to the fourth embodiment. FIG. 24A is a schematic cross-sectional view illustrating a configuration of a lighting device according to Embodiment 5. FIG. 24B is an enlarged cross-sectional view of the wavelength conversion element according to Embodiment 5 and the vicinity thereof. FIG. 24C is a schematic perspective view showing the lighting device according to Embodiment 5, and a projected image projected from the lighting device. FIG. 24D is a photograph showing the shape of the wavelength conversion member according to Embodiment 5. FIG. 24E is a graph showing a first measurement result of the film thickness of the wavelength conversion element according to Embodiment 5. FIG. 24F is a graph illustrating a second measurement result of the film thickness of the wavelength conversion element according to Embodiment 5. FIG. 24G is a graph showing a third measurement result of the film thickness of the wavelength conversion element according to Embodiment 5. FIG. 24H is a graph showing a color distribution in a light emitting region of the wavelength conversion element according to Embodiment 5. FIG. 25A is a schematic cross-sectional view illustrating a wavelength conversion element and an irradiation direction of excitation light in the light emitting device according to Embodiment 6. FIG. 25B is a graph illustrating a luminance distribution of the wavelength conversion element of the light emitting device according to Embodiment 6. FIG. 25C is a table illustrating an overview of experimental results of the light emitting device according to Embodiment 6. FIG. 26 is a diagram illustrating a configuration of a conventional light emitting device.

  Hereinafter, embodiments will be described with reference to the drawings. Each of the embodiments described below shows a specific example of the present disclosure. Therefore, numerical values, shapes, materials, components, arrangement positions of components, connection forms, and the like shown in the following embodiments are examples and do not limit the present disclosure. Therefore, among the components in the following embodiments, components not described in the independent claims of the present disclosure are described as arbitrary components. The drawings are schematic or conceptual, and the relationship between the thickness and the width of each part, the size ratio between the parts, and the like are not necessarily the same as actual ones. Even when substantially the same part is represented, the dimensions and ratios may be represented differently depending on the drawings. In some cases, redundant description of substantially the same configuration may be omitted.

  Further, in this specification, the term “upward” does not indicate an upward direction (vertically upward) in absolute space recognition, but is a term defined by a relative positional relationship based on a stacking order in a stacked configuration. Used as Also, the term "above" refers not only to the case where two components are spaced apart from each other and there is another component between the two components, but also The same applies to the case where two components are arranged and touch each other.

(Embodiment 1)
Hereinafter, the wavelength conversion element according to the first embodiment will be described with reference to the drawings.

[Basic configuration]
FIG. 1 is a schematic cross-sectional view illustrating a configuration of a wavelength conversion element 1 according to the present embodiment. As shown in FIG. 1, the wavelength conversion element 1 according to the present embodiment is an element including a support member 2 having a support surface 2a and a wavelength conversion member 40 disposed above the support surface 2a.

  The support member 2 is a member that supports the wavelength conversion member 40. In the present embodiment, the support member 2 has a plate shape, and supports the wavelength conversion member 40 via the reflection member 3 arranged on the planar support surface 2a. The support member 2 functions as a heat sink that dissipates heat generated by the wavelength conversion member 40.

  The wavelength conversion member 40 includes a plurality of first phosphor particles 41 that absorb the excitation light 84 and emit fluorescence, and a transparent binding material 42 that couples the plurality of first phosphor particles 41. The wavelength conversion member 40 has a bonding surface 7 located on the support surface 2a side and a radiation surface 6 located on the opposite side of the support surface. The radiation surface 6 includes the radiation surface 6 that faces the bonding surface 7, receives the excitation light 84, and emits the emission light 95. An area of the support surface 2a facing the bonding surface 7 is an arrangement area 2d where the wavelength conversion member 40 is arranged. In the present embodiment, the arrangement area 2d is a plane.

  Emission light 95 including first emission light 85 and second emission light 91 is emitted from emission surface 6 of wavelength conversion member 40. The first emission light 85 is the scattered excitation light 84. The second outgoing light 91 is fluorescent light whose wavelength has been converted from the excitation light 84. Further, the radiation surface 6 of the wavelength conversion member 40 includes a plurality of minute protrusions 5a and a plurality of minute recesses 5b.

  The radiation surface 6 includes a peripheral region 6a including the peripheral edges E1 and E2 of the radiation surface 6, and a central region 6b surrounded by the peripheral region 6a. At least a part of the peripheral region 6a has a first top P1 protruding from the central region 6b in a direction away from the support surface 2a. The radiation surface 6 has a first inclined portion S1 that is inclined toward the support surface 2a from the first top P1 toward the central region 6b. The radiation surface 6 has a large number of microscopic unevenness microscopically, but macroscopically, the radiation surface 6 is inclined toward the support surface 2a from the first top P1 toward the central region 6b. It has one inclined portion S1. The wavelength conversion member 40 includes a plurality of first phosphor particles 41 made of the same material in the central region 6b and the first top P1.

  In the present embodiment, a plurality of minute projections 5a are formed on the radiation surface 6 of the first inclined portion S1. Here, the minute projections 5a are projections that are detected in large numbers when the radiation surface 6 is viewed microscopically. The dimension of the minute protrusion 5a in the direction parallel to the support surface 2a is 50% or less of the thickness of the wavelength conversion member 40. The central region 6b includes a flat portion F1 whose inclination is gentler than that of the first inclined portion S1. In addition, in the example shown in FIG. 1, the flat portion F1 is a part of the central region 6b, but the entire central region 6b may be the flat portion F1. Further, the peripheral region 6a may include the flat portion F1. In addition, minute unevenness may be formed in the flat portion F1 here, as long as it is macroscopically flat. For example, the flat portion F1 may include unevenness whose dimension in the direction parallel to the support surface 2a is about 50% or less of the thickness of the wavelength conversion member 40.

  In the present embodiment, the peripheral region 6a is disposed at a position opposite to the first top P1 with respect to the central region 6b, and projects from the central region 6b in a direction away from the support surface 2a. It has a top P2. The radiation surface 6 has a second inclined portion S2 that is inclined toward the support surface 2a from the second top portion P2 toward the central region 6b.

As described above, in the present embodiment, the thickness of the wavelength conversion member 40 is thicker near the first top P1 and the second top P2 of the peripheral region 6a than in the central region 6b. That is, a concave shape is formed from the first top P1 to the second top P2. As shown in FIG. 1, the film thickness _{d e} is the first apex P1 of the wavelength conversion member 40, larger than the thickness _{d c} in the central region _{6b (d e> d c)} .

  In the present embodiment, the height from support surface 2a to first top P1 is higher than the height from support surface 2a to second top P2. Here, as described later, the excitation light 84 is obliquely incident on the central region 6b of the wavelength conversion member 40. Therefore, when the height from the support surface 2a to the first top P1 is higher than the height from the support surface 2a to the second top P2 as in the present embodiment, the excitation light 84 is transmitted from the second top P2 side. By being incident in the direction toward the first top P1, it is possible to reduce the possibility that the excitation light 84 is blocked by the peripheral region 6a of the wavelength conversion member 40. Therefore, the ratio of the component of the excitation light 84 incident on the central region 6b can be increased. That is, the utilization efficiency of the excitation light 84 can be improved.

  In the wavelength conversion member 40 shown in FIG. 1, in the cross section passing through the central region 6b, as described above, the first apex P1 projecting from the central region 6b is provided in one peripheral region 6a (the peripheral region 6a on the right side in FIG. It is formed. The radiation surface 6 has a third inclined portion S3 that is sharply inclined toward the support surface 2a from the first top P1 toward the periphery E1 of the radiation surface 6. Similarly, a second top P2 is formed in the other peripheral area 6a (the peripheral area 6a on the left side in FIG. 1). The radiating surface 6 has a fourth inclined portion S4 that is sharply inclined from the second top portion P2 toward the peripheral edge E2 of the radiating surface 6 toward the support surface 2a.

  The reflection member 3 is disposed between the wavelength conversion member 40 and the support member 2 and reflects at least one of excitation light and fluorescence. In the present embodiment, the reflection member 3 is a reflection film formed on the support surface 2a of the support member 2.

  The function of the wavelength conversion element 1 having the configuration described above will be described. In the wavelength conversion element 1 according to the present embodiment, the excitation light 84 emitted from an excitation light source (not shown) is incident on the radiation surface 6 of the wavelength conversion member 40. In the present embodiment, laser light is used as the excitation light 84. At this time, the excitation light 84 is light of high light density in which light of high light intensity is converged in a predetermined small area. In FIG. 1, most of the excitation light 84 incident on the wavelength conversion element 1 is incident on an excitation region 150 which is a part of the central region 6 b of the radiation surface 6.

  The excitation light 84 incident on the excitation region 150 is incident on the first phosphor particles 41 or the transparent binder 42 of the wavelength conversion member 40. The interface between media having different refractive indices, that is, the interface between air and the wavelength conversion member 40 and the interface between the first phosphor particles 41 and the transparent binder 42 are provided on the radiation surface 6 and the inside of the wavelength conversion member 40. Exists. For this reason, the excitation light 84 incident on the wavelength conversion member 40 is irregularly reflected or multiple-reflected on the radiation surface 6 and inside the wavelength conversion member 40, and a part of the excitation light 84 is the first emission light 85 (shown in FIG. 1). The light is emitted from the wavelength conversion member 40 as a solid arrow). At this time, the first outgoing light 85 is irregularly or multiplely reflected by the radiation surface 6 of the wavelength conversion member 40 and the interface existing inside. Therefore, the directivity of the excitation light 84 made of laser light in the first emission light 85 is reduced. Therefore, the wavelength conversion element 1 can emit the first emission light 85 as light whose emission direction is omnidirectional. That is, in the wavelength conversion element 1 according to the present embodiment, a sufficient scattering action can be ensured.

  On the other hand, a part of the excitation light 84 is absorbed by the first phosphor particles 41 and emitted as wavelength-converted fluorescence. This fluorescence is reflected directly or after being irregularly or multiplely reflected on the interface between the first phosphor particles 41 and the transparent binder 42, and then emitted from the emission surface 6 of the wavelength conversion member 40 (see FIG. 1). (Dashed arrow shown).

  Therefore, the emission surface 95 of the wavelength conversion element 1 emits the emission light 95 that is a mixed light in which the first emission light 85 and the second emission light 91 are mixed. At this time, the region from which the emission light 95 is emitted is from the emission region 151 which is a region larger than the excitation region 150 because both the first emission light 85 and the second emission light 91 are multiple-reflected in the wavelength conversion member 40. Is emitted.

  Hereinafter, more specific embodiments including optional components that are not essential will be described.

  As shown in FIG. 1, in the wavelength conversion element 1, the reflection member 3 is disposed on the support surface 2 a of the support member 2, and the wavelength conversion member 40 is disposed on the surface of the reflection member 3. The reflection member 3 includes a first reflection film 3b mainly made of metal, a second reflection film 3c mainly made of a dielectric multilayer film, and an adhesion layer 3a for adhering the support member 2 and the first reflection film 3b. including.

  The wavelength conversion member 40 includes a plurality of first phosphor particles 41 and a transparent binder 42 that couples the plurality of first phosphor particles 41. The plurality of first phosphor particles 41 may be dispersed in the transparent binder 42.

As the first phosphor particles 41, the wavelength of the excitation light is, if it is 490nm or less of blue light above 420 nm, cerium (Ce) is activated _{(Y x Gd 1-x)} 3 (Al y Ga 1-y An yttrium aluminum garnet (YAG) phosphor such as ₅ O ₁₂ (0.5 ≦ x ≦ 1, 0.5 ≦ y ≦ 1) can be used. The median diameter D50 of the first phosphor particles 41 included in the wavelength conversion member is, for example, 2 μm or more and 30 μm or less. When such first phosphor particles 41 are used, the thickness of the wavelength conversion member 40 is, for example, 2 μm or more and 50 μm or less in the excitation region 150.

Other materials that constitute the first phosphor particles 41 include europium (Eu) activated α-SiAlON, Eu activated (Ba, Sr) Si ₂ O ₂ N _2, etc. according to the wavelength of light emitted from the phosphor. Can be used. At this time, when the first phosphor particles 41 convert the excitation light 84 into the second emission light 91, the heat generated by the first phosphor particles 41 is quickly discharged to the support member 2. It is made of a material having a high rate, for example, a material having a power of 5 W / mK or more.

  The transparent binder 42 may be formed of a transparent material having a large difference in refractive index from the first phosphor particles 41. Thereby, the light scattering effect at the interface between the first phosphor particles 41 and the transparent binder 42 can be enhanced. The material forming the transparent binder 42 is, for example, a transparent material containing silicon (Si) and oxygen (O) as main components, and examples thereof include glass, silsesquioxane, and silicone.

  In the wavelength conversion member 40, the plurality of first phosphor particles 41 quickly convert the heat generated in the first phosphor particles 41 to the support member 2 when converting the excitation light 84 into the second emission light 91. It may have a configuration capable of discharging heat. Specifically, the plurality of first phosphor particles 41 having higher thermal conductivity than the transparent binder 42 are arranged close to each other. The transparent binder 42 is filled between the plurality of first phosphor particles 41. At this time, since the excitation light 84 is scattered at the interface between the first phosphor particles 41 and the transparent binder 42, the larger the area of the interface, the better. Therefore, the first phosphor particles 41 adjacent to each other may be separated from each other by more than the wavelength of the excitation light 84 while being close to each other, and the transparent binder 42 may be filled therebetween. At this time, there is no problem even if the adjacent first phosphor particles 41 partially contact.

The material forming the support member 2 has a high thermal conductivity and a small difference in thermal expansion coefficient from the transparent binder 42 in order to more efficiently absorb the heat generated in the wavelength conversion element 1. Is also good. For example, the material forming the support member 2 may be a material having a thermal conductivity of 20 W / mK or more and a thermal expansion coefficient of 1 × 10 ⁻⁵ / K or less. Specifically, the support member 2 may include silicon (Si), silicon carbide (SiC), sapphire (Al ₂ O ₃ ), aluminum nitride (AlN), diamond, or the like. Further, the support member 2 may be a semiconductor crystal substrate or a ceramic substrate made of these materials.

The reflection member 3 has a high reflectance in, for example, the spectrum of the excitation light 84 and the spectrum of the fluorescence generated by the first phosphor particles 41. That is, of the excitation light 84 incident on the wavelength conversion member 40 and the first emission light 85 and the second emission light 91 generated by the wavelength conversion member 40, the light reaching the reflection member 3 is efficiently converted into the wavelength conversion member 40. It has the function of reflecting to the side. Therefore, the first reflection film 3b is specifically formed using a metal film such as aluminum (Al), silver (Ag), a silver alloy, and platinum (Pt). The second reflection film 3c is formed as a multilayer film using a dielectric film such as SiO ₂ , Al ₂ O ₃ , ZrO ₂ , and TiO ₂ .

  The support surface 2a of the support member 2 on which the reflection member 3 is formed may be flat and mirror-finished. Thereby, the reflection member 3 formed on the support surface 2a can be formed of a flat film. Therefore, the first outgoing light 85 and the second outgoing light 91 reaching the reflecting member 3 can be efficiently reflected.

[Detailed configuration and manufacturing method]
Subsequently, a specific shape and dimensions of the wavelength conversion element 1 will be described in addition to a manufacturing method. The method of manufacturing the wavelength conversion element 1 will be specifically described, including a method that is not essential.

  First, a wafer-shaped member serving as a base of the support member 2 is prepared. In this embodiment, a wafer that is a silicon substrate having a diameter of 3 inches and a thickness of 0.38 mm is prepared as the support member 2. As the silicon substrate, a substrate whose support surface 2a side is mirror-finished and planarized by mechanochemical polishing is used.

Subsequently, the reflection member 3 is formed by sequentially forming the adhesion layer 3a, the first reflection film 3b, and the second reflection film 3c on the support surface 2a, which is one main surface of the support member 2, by an evaporation method or the like. I do. More specifically, the reflection member 3 is, in order from the support member 2 side, an adhesion layer 3 a made of Al ₂ O ₃ having a thickness of 127 nm and Ni having a thickness of 27 nm, and Ag having a thickness of 150 nm. first reflecting film 3b, and includes a second reflecting layer 3c having a thickness is _Al 2 _{O 3} and the thickness of 75nm is SiO ₂ and the thickness of 25nm made of TiO ₂ Metropolitan of 28nm. The second reflection film 3c has both functions of a surface protection layer for protecting the first reflection film 3b and a reflection layer for suppressing light absorption in the first reflection film 3b made of metal. . In addition, the adhesion layer 3a suppresses peeling of the reflection member 3 from the support member 2 in a dicing step described later when the wafer is divided into individual wavelength conversion elements 1.

  Subsequently, a screen mesh print mask having a plurality of predetermined openings is disposed above the support surface 2a of the support member 2. At this time, the openings are formed two-dimensionally at a pitch of 2 mm or more and 10 mm or less in the plane. In the present embodiment, one having a pitch of 3.5 mm and one having a pitch of 5 mm were manufactured. For example, at a pitch of 5 mm, about 100 openings are formed within a range of 3 inches in diameter. The screen mesh print mask is formed by weaving, for example, metal fibers such as stainless steel or synthetic fibers such as polyester. Printing by passing through a mesh network makes it possible to form a thin film by printing because the volume of the paste passing therethrough is smaller than that of an opening mask made of metal or the like. In addition, by using a shape conforming to the desired shape of the wavelength conversion member 40 as the shape of the opening, the shape of the wavelength conversion member 40 can be freely formed. Further, the thickness of the screen mesh print mask can be set according to a desired film thickness of the wavelength conversion member 40 of the wavelength conversion element 1.

Subsequently, a phosphor paste in which the first phosphor particles 41 are mixed with a solution in which a raw material constituting the transparent binder 42 is dissolved in an organic solvent is produced. At this time, using a Ce-activated Y ₃ Al ₅ O ₁₂ phosphor having a median diameter D50 of _3, 4, 6, and 9 μm, respectively, the median diameter of the first phosphor particles 41 is changed as a parameter, and the phosphor paste is Make it. In the wavelength conversion member 40 according to the present embodiment, as the transparent binder 42, a transparent material whose main component is polymethylsilsesquioxane is used. Therefore, as the phosphor paste, one obtained by dispersing a plurality of the first phosphor particles 41 in a transparent binder obtained by dissolving silsesquioxane in an organic solvent was used. At this time, an organic solvent having a lower boiling point than the temperature in the high-temperature curing step described later is selected. After the high-temperature curing step, the mixing ratio is determined so that the ratio between the first phosphor particles 41 and the transparent binder 42 becomes a desired value. The amount of the organic solvent is determined so that the above-mentioned phosphor paste has a desired viscosity.

  Subsequently, the phosphor paste produced in the above process is injected into the opening of the screen mesh print mask above the wafer. At this time, the phosphor paste is arranged so as to sufficiently fill the opening.

  Subsequently, the unnecessary phosphor paste overflowing from the opening with the squeegee is removed, and the screen mesh print mask is pressed against the supporting surface 2a of the wafer and separated therefrom, so that the phosphor paste filled in the opening is removed from the supporting surface 2a. Transfer to

  Subsequently, the print mask is removed, and the wafer on which the plurality of phosphor pastes are formed in a predetermined pattern on the surface is heated in a high-temperature furnace or the like at a temperature of about 200 ° C. for about 2 hours, for example. By this high-temperature curing step, the raw material of the transparent binder in the phosphor paste is condensed, and a wafer-shaped wavelength conversion element in which the plurality of first phosphor particles 41 are fixed in the transparent binder 42 is formed. The wavelength conversion element 1 manufactured as described above will be described with reference to FIG.

  FIG. 2 is a diagram illustrating a shape of the support surface 2a of the wavelength conversion element 1 according to the present embodiment when viewed from above. FIG. 2 shows a photograph (a) of a part of the wavelength conversion element 1 manufactured using the above-described manufacturing process when viewed from the top, and a plan view in which one wavelength conversion element 1 shown in the photograph (a) is enlarged ( b) are shown. In the plan view (b), the shapes of the wavelength conversion member 40 and the support member 2 in the wavelength conversion element 1 are schematically shown. In addition, the frame shown by the broken line in the photograph (a) and the plan view (b) shows the outline of the support member 2 after being separated as described later.

  In this embodiment, a plurality of wavelength conversion members 40 are formed on a wafer using a screen mesh print mask in which circular openings having a diameter of 2.6 mm are formed at a pitch of 3.7 mm.

  Next, the wafer to which a plurality of the wavelength conversion members 40 having a film thickness of 2 μm or more and 50 μm or less fixed by the above process is divided by dicing. Specifically, using a dicing blade having a blade width of 0.2 mm, the wafer is divided at a pitch of 3.7 mm. At this time, since the divided portion having a width of 0.2 mm corresponding to the thickness of the dicing blade is cut by the dicing blade, the wavelength conversion element 1 of 3.5 mm square as shown in the plan view (b) of FIG. 2 is manufactured. You.

  The wavelength conversion element 1 in which the wavelength conversion member 40 having a film thickness of 2 μm or more and 50 μm or less is formed on the support member 2 by the above manufacturing method can be easily manufactured.

  The features of the wavelength conversion element 1 manufactured as described above will be described in more detail with reference to FIGS. FIG. 3 is a photograph obtained by observing a cross section of the wavelength conversion element 1 according to the present embodiment using a scanning electron microscope (SEM). FIG. 3 shows a cross section taken along line III-III shown in FIG. FIG. 3 shows a cross-sectional photograph (a) and an enlarged photograph (b) in which a part thereof is enlarged. The enlarged photograph (b) is an enlarged photograph of a broken-line frame portion of the sectional photograph (a). The embedding resin shown in FIG. 3 is a resin used for observation with a scanning electron microscope, and is not a component of the wavelength conversion element 1.

  As shown in FIG. 2, the peripheral portion of the support member 2 is exposed from the wavelength conversion member 40 when the support surface 2 a is viewed from above. That is, in the wavelength conversion element 1, the arrangement area of the wavelength conversion member 40 is formed to be smaller than the outer shape of the support member 2. By forming the wavelength conversion element 1 in this manner, when the wavelength conversion element 1 is used, for example, as a component of a light emitting device, an area around the wavelength conversion element 1 where the wavelength conversion member 40 is not formed is formed by a collet or the like. By chucking and transporting, it can be easily fixed to a place where the wavelength conversion element 1 is arranged, such as a base of a light emitting device.

  As shown in FIG. 3, the wavelength conversion element 1 includes a support member 2 which is a silicon substrate, a reflection member 3 formed of a silver film, a dielectric multilayer film and the like disposed on the support member 2, and a reflection member. And a wavelength conversion member 40 disposed on the light-emitting element 3. The wavelength conversion member 40 includes a plurality of first phosphor particles 41 and a transparent binder 42 made of silsesquioxane. In the example shown in FIG. 3, the thickness of the wavelength conversion member 40 was about 20 μm. The first phosphor particles 41 are dispersed in the transparent binder 42, but the adjacent first phosphor particles 41 are close to each other. With this arrangement, the heat generated in the first phosphor particles 41 can be efficiently conducted to the support member 2 via the adjacent first phosphor particles 41. That is, heat generated in the first phosphor particles 41 can be mainly transmitted to the support member 2 via the first phosphor particles 41 having a higher thermal conductivity than the transparent binder 42. A plurality of minute projections 5a are formed on the surface (radiation surface 6) of the wavelength conversion member 40. At least a part of the plurality of minute protrusions 5 a is formed by protruding a part of the plurality of first phosphor particles 41 on the radiation surface 6. That is, the minute protrusions 5a are formed along the surface of the first phosphor particles 41. A minute concave portion 5b is formed beside the minute convex portion 5a. By forming minute irregularities on the surface of the wavelength conversion member 40 in this manner, the excitation light 84 can be efficiently scattered. Further, as shown in the cross-sectional photograph (a) of FIG. 3, gentle irregularities are formed at intervals of about 5 to 10 particles. The period of the gentle unevenness, that is, the interval between the adjacent convex portions or the interval between the adjacent concave portions is larger than 50% of the average film thickness of the uneven portion of the wavelength conversion member 40 and is about 5 times or less. As described above, the excitation light 84 can be more efficiently scattered by forming gentle unevenness on the surface of the wavelength conversion member as compared with the minute unevenness.

[Light emitting device and lighting device]
Next, a light emitting device and a lighting device using the wavelength conversion element according to Embodiment 1 will be described in detail with reference to FIG. FIG. 4 is a schematic cross-sectional view illustrating a configuration of lighting device 201 according to the present embodiment.

  As shown in FIG. 4, lighting device 201 according to the present embodiment includes light emitting device 101 and light projecting member 220.

  The light projecting member 220 is an optical member that receives the light 95 emitted from the light emitting device 101 and emits the projection light 96. In the present embodiment, light projecting member 220 is a curved mirror such as a parabolic mirror.

  The light emitting device 101 according to the present embodiment mainly includes the above-described wavelength conversion element 1, the semiconductor light emitting device 110, and the light collecting optical member 120.

  In the light emitting device 101, the semiconductor light emitting device 110 and the wavelength conversion element 1 are fixed to the base 50. The base 50 is a housing made of a metal such as an aluminum alloy.

  The semiconductor light emitting device 110 is an excitation light source that irradiates the wavelength conversion element with excitation light. In the present embodiment, the semiconductor light emitting device 110 is, for example, a TO-CAN type semiconductor laser, and is connected to the printed circuit board 160. The semiconductor light emitting device 111 is mounted on the semiconductor light emitting device 110. The semiconductor light emitting device 110 is inserted into an opening formed on the bottom surface of the base 50. The outgoing light 81 emitted from the semiconductor light emitting element 111 is emitted upward in FIG.

  The light collecting optical member 120 includes a lens 120a and a reflective optical element 120b having a reflective surface. The lens 120a and the reflection optical element 120b are arranged above the semiconductor light emitting device 110.

  The light emitting device 101 further includes a printed circuit board 160 on which the light detector 130 is mounted. The printed circuit board 160 is disposed on the bottom side of the base 50, and a connector 170 for connection to an external circuit is connected to the printed circuit board 160.

  The semiconductor light emitting device 111 is a multi-mode laser having an optical waveguide having a width of 10 μm or more. The reflection optical element 120b is, for example, a reflection mirror on which a plurality of concave mirror surfaces are formed. With this configuration, the outgoing light 81 emitted upward from the semiconductor light emitting element 111 in FIG. 4 becomes parallel light from the lens 120a and enters the reflective optical element 120b. The outgoing light 81 incident on the reflective optical element 120b is reflected downward by the concave mirror surface of the reflective optical element 120b in FIG. 4, and becomes the excitation light 84 for irradiating the wavelength conversion element 1 from obliquely above. That is, the excitation light 84 applied to the wavelength conversion element 1 is partially converted by the wavelength conversion member 40 of the wavelength conversion element 1, and the first emission light 85 composed of scattered light and the second emission light composed of fluorescent light are emitted. The emitted light 95 is composed of the emitted light 91 and emitted from the light emitting device 101.

  The outgoing light 95 emitted from the light emitting device 101 becomes the projection light 96 which is substantially parallel light by the light projecting member 220 and is emitted from the lighting device 201.

  The light emitting device 101 includes a connector 170. The connector 170 is a connector that can be connected to an external circuit. Accordingly, power can be externally applied to the semiconductor light emitting device 110 and the printed circuit board 160. The light emitting device 101 further includes a light detector 130 such as a photodiode. Photodetector 130 is mounted on printed circuit board 160. Thus, light from the wavelength conversion element 1 can be received, and a detection signal indicating the light emitting state of the light emitting device 101 can be output to the outside. Further, on the upper part of the wavelength conversion element 1, a light transmitting member 140, for example, a cover glass is arranged. The light transmitting member 140 is attached to a holder 53 formed of a metal such as aluminum similarly to the base 50, and is fixed so as to cover the wavelength conversion element 1 and the condensing optical member 120 fixed to the base 50. . Thereby, the light-collecting optical member 120 and the wavelength conversion element 1 constituting the light emitting device 101 can be protected. In the light emitting device 101 according to the present embodiment, the semiconductor light emitting device 110 and the condensing optical member 120 are disposed above the printed circuit board 160 used for electric wiring, and the wavelength converting element 1 disposed below is disposed obliquely upward. From the excitation light 84 can be incident. Therefore, the light emitting device 101 can be made thin.

  The excitation light 84 is obliquely incident on the radiation surface 6 from the second top P2 side, and the wavelength conversion member 40 converts the wavelength of the excitation light 84. As described above, the excitation light 84 is incident from the second top P2 side toward the first top P1, so that the excitation light 84 can be reduced from being blocked by the peripheral region 6a of the wavelength conversion member 40. Therefore, the ratio of the component of the excitation light 84 incident on the central region 6b can be increased. That is, the utilization efficiency of the excitation light 84 can be improved.

  Further, in the above configuration, the beam shape of the excitation light 84 is shaped using the reflection optical element 120b. With this configuration, the light intensity distribution of the excitation light 84 applied to the wavelength conversion element 1 can be made uniform.

  In the present embodiment, as shown in FIG. 4, the projection light 96 is emitted in a direction substantially opposite to the direction in which the excitation light 84 enters the wavelength conversion member 40. In other words, at a position where the excitation light 84 is incident on the wavelength conversion member 40, a straight line orthogonal to the optical axis of the excitation light 84, including a straight line parallel to the support surface, and a plane PV perpendicular to the support surface 2a. The projection light 96 is emitted from the plane PV toward the excitation light source (semiconductor light emitting device 110).

  Further, the light emitting device 101 emits light using the semiconductor light emitting device 110 which is a semiconductor laser device and the wavelength conversion element 1 including a phosphor. Therefore, light with higher luminance can be emitted from the wavelength conversion element 1 than when a light emitting diode or the like is used. The light emitted from the light emitting device 101 can be radiated to a distant place using the light projecting member 220.

[Fixation of wavelength conversion element]
In the light emitting device 101 according to the present embodiment, a detailed configuration near the fixed portion of the wavelength conversion element 1 will be described with reference to the drawings. FIG. 5 is an enlarged view near the wavelength conversion element 1 of the light emitting device 101 shown in FIG.

  The wavelength conversion element 1 has a rectangular support member 2 when viewed from above the support surface 2a. Then, the wavelength conversion member 40 is formed on the reflection member 3 on the support surface 2a.

  On the base 50 of the light emitting device 101, a concave storage portion 50a having a rectangular shape in a top view and one size larger than the outer shape of the support member 2 is formed. Then, the wavelength conversion element 1 is fixed to the bottom surface of the storage unit 50a.

  The wavelength conversion element 1 is fixed to the base 50 by an adhesive member 55. As the adhesive member 55, for example, an adhesive resin mainly containing silicone resin, epoxy resin, or the like, or a solder mainly containing AuSn, SnAgCu, or the like can be used.

  Further, in the light emitting device 101 according to the present embodiment, the light shielding cover 51 is disposed above the storage unit 50a of the base 50 in which the wavelength conversion element 1 is stored. The light-shielding cover 51 has an opening for allowing the excitation light 84 and the emission light 95 to pass therethrough, and is formed of a metal plate having a black surface. Specifically, it is a stainless steel plate painted black or an aluminum alloy plate whose surface is black anodized. The light-shielding cover 51 is disposed so as to cover at least a part of the peripheral region 6a in the wavelength conversion member 40 of the wavelength conversion element 1. The light shielding cover 51 is firmly fixed to the base 50 with, for example, screws 52. As a result, the excitation light 84 is applied to the area of the support surface 2a of the wavelength conversion element 1 where the wavelength conversion member 40 is not formed, thereby suppressing generation of stray light.

  The emitted light 95 emitted from the wavelength conversion member 40 in the direction of the side wall 50b of the storage unit 50a is attenuated by multiple reflection in the space between the storage unit 50a and the light shielding cover 51. As a result, it is possible to suppress the stray light from being included in the projection light 96 of the lighting device.

  Further, the wavelength conversion member 40 of the wavelength conversion element 1 has a concave shape in which the thickness of the central region 6b is small and the thickness of the peripheral region 6a is larger than that of the central region 6b. For this reason, when manufacturing the light emitting device 101, it is possible to suppress the light shielding cover 51 from contacting the light emitting region located in the central region 6b of the wavelength conversion member 40. That is, even when the light-shielding cover 51 approaches the wavelength conversion member 40, the light-shielding cover 51 contacts the peripheral region 6a before the central region 6b of the wavelength conversion member 40. It is difficult to contact the region 151. For this reason, it can suppress that the optical characteristic of the output light 95 of the wavelength conversion element 1 falls.

  Further, in the present embodiment, a part or all between the side surface of the support member 2 and the storage part 50a may be filled with the adhesive member 55. Thereby, the heat transmitted from the wavelength conversion member 40 to the support member 2 can be more effectively conducted to the base 50.

  With the above configuration, the wavelength conversion element 1 according to the present embodiment and the light emitting device 101 using the same can emit high-luminance emission light. Such a light emitting device 101 can realize the lighting device 201 having a high luminous intensity when the lighting device 201 is configured using the small light projecting member 220. Therefore, the light emitting device 101 according to this embodiment is suitable as a light source used for a headlight of a vehicle or the like.

[Operation and effect]
Next, the operation and effect of the wavelength conversion element 1 according to the present embodiment will be described based on experimental data with reference to the drawings.

  The experimental data was evaluated by mounting the wavelength conversion element 1 on the light emitting device 101 shown in FIG. The luminance of the emitted light 95 from the light emitting device 101 and the surface temperature of the wavelength conversion element 1 are measured using thermography from above in FIG. 4 with the light projecting member 220 removed from the lighting device 201 shown in FIG. did. The method of measuring the surface temperature is not limited to thermography, and may be another method.

  The light emitting device 101 includes a semiconductor light emitting device 110 for irradiating the wavelength conversion element 1 with the excitation light 84. Further, a reflection optical element 120b for shaping the beam of the excitation light 84 applied to the wavelength conversion element 1 is provided. The wavelength conversion element 1 and the semiconductor light emitting device 110 are firmly fixed to the base 50 with a material having high thermal conductivity in order to radiate the generated heat to the outside.

  As shown in FIG. 1, the wavelength conversion element 1 fixed to the base 50 is irradiated with the excitation light 84 in an oblique direction with respect to the radiation surface 6. The excitation light 84 is a laser light having a peak wavelength of 430 nm or more and 470 nm or less. A part of the excitation light 84 applied to the emission surface 6 is absorbed by the first phosphor particles 41 of the wavelength conversion member 40, converted into fluorescence having another wavelength, and emitted from the emission surface 6 in all directions. The second emitted light 91 is emitted.

  On the other hand, of the light that has entered the wavelength conversion member 40, the light that has not been absorbed by the first phosphor particles 41 is reflected on the surface or inside the wavelength conversion member 40, and the first emission light 85 from the wavelength conversion member 40. Radiated as At this time, the light reflected inside the wavelength conversion member 40 is multiple-reflected by the plurality of first phosphor particles 41 and emitted from the radiation surface 6 of the wavelength conversion member 40. For this reason, the light reflected inside the wavelength conversion member 40 is emitted as the first outgoing light 85 emitted in all directions from the emission surface 6 of the wavelength conversion member 40. On the other hand, the light reflected from the radiation surface 6 of the wavelength conversion member 40 or the vicinity of the radiation surface 6 and radiated as the first emission light 85 also has minute projections and depressions on the radiation surface 6 of the wavelength conversion member 40. Alternatively, the light is scattered and reflected at the interface between the first phosphor particles 41 and the transparent binder 42 existing in the vicinity of the radiation surface 6 and emitted. For this reason, light reflected at or near the radiation surface 6 and radiated as the first outgoing light 85 is also radiated in all directions from the radiation surface 6 of the wavelength conversion member 40.

  As a result, the emission surface 6 of the wavelength conversion member 40 emits the emission light 95 that is a mixed light in which the first emission light 85 and the second emission light 91 emitted in all directions are mixed. At this time, for example, as shown in FIG. 1, the wavelength conversion member 40 has a concave shape in which the thickness of the central region 6b is smaller than the maximum thickness of the peripheral region 6a. The central region 6b, which is the concave bottom surface, has a flat portion F1 with a small change in thickness. Further, the flat portion F1 near the concave bottom portion may be set to be larger than the excitation region 150 of the excitation light 84 and the light emission region 151 of the emission light 95. Thereby, the chromaticity distribution of the emitted light 95 emitted from the wavelength conversion member 40 can be made uniform.

  As a result, when the first outgoing light 85 is blue light and the second outgoing light 91 is yellow light, the wavelength conversion member 40 can emit outgoing light 95 composed of white light with a small chromaticity distribution bias.

  Next, optical characteristics when the wavelength conversion element 1 of the present embodiment is irradiated with the excitation light 84 having a predetermined light density will be described with reference to FIG. FIG. 6 is a diagram illustrating optical characteristics of the wavelength conversion element 1 according to the present embodiment.

First, the graph (a) of FIG. 6 is a diagram showing the temperature dependence of the quantum efficiency of the Ce-activated Y ₃ Al ₅ O ₁₂ phosphor particles used as the first phosphor particles 41. The quantum efficiency of the Ce-activated Y ₃ Al ₅ O ₁₂ phosphor particles decreases as the temperature increases, and when the temperature exceeds 150 ° C., the quantum efficiency starts to decrease rapidly.

  The graph (b) in FIG. 6 shows that the excitation light 84 is irradiated to the wavelength conversion member 40, and the excitation light scattered and reflected by the wavelength conversion member 40 and the excitation light 84 are absorbed and converted by the wavelength conversion member 40 and emitted. FIG. 7 is a diagram for explaining chromaticity coordinates of emitted light 95 (white light), which is mixed light obtained by mixing fluorescent light with white light. In the present embodiment, an excitation light source that emits outgoing light that is blue laser light having chromaticity coordinates (0.161, 0.014) and fluorescent light having chromaticity coordinates (0.426, 0.547) are used. An experiment was performed using phosphor particles (YAG) that emitted light. Therefore, in the graph (b) of FIG. 3, the chromaticity coordinates (0.161, 0.014) and the straight line (trajectory of the mixed light) connecting (0.426, 0.547) and the blackbody radiation locus (0.317, 0.327), which are the chromaticity coordinates where.

  Graphs (c) and (e) of FIG. 6 show that the wavelength conversion element 1 according to the present embodiment has a square-shaped excitation having an optical output of about 3.2 watts and an irradiation range of about 0.7 mm on a side. It is the result of measuring the relationship between the thickness of the light emitting region portion of the wavelength conversion member 40 and the peak temperature of the surface of the wavelength conversion member 40 when the light 84 is incident. The graph (c) of FIG. 6 shows the result of comparison when the median diameter D50 of the first phosphor particles is 3 μm, 4 μm, 6 μm, and 9 μm. Here, the volume ratio between the first phosphor particles 41 and the transparent binder 42 was 45:65. In the graph (e) of FIG. 6, the measurement was performed by setting the median diameter D50 of the first phosphor particles 41 to 6 μm and changing the volume ratio between the first phosphor particles 41 and the transparent binder 42. 38%, 45%, 55%, and 65% described in the figure are the ratios of the transparent binder 42 to the wavelength conversion member 40. That is, when the volume Vb of the transparent binder and the volume Vf of the first phosphor particles are used, the ratio is expressed as Vb / (Vf + Vb).

  That is, when these ratios are converted into the ratio Vf / (Vf + Vb) of the first phosphor particles 41 to the wavelength conversion member 40, they are 62%, 55%, 45%, and 35%, respectively.

  As described above, when the temperature of the phosphor particles increases, the conversion efficiency of the phosphor decreases. In particular, when the temperature exceeds 150 ° C., the conversion efficiency is sharply reduced. In such a case, the amount of heat generated by the wavelength conversion member 40 increases rapidly, causing quenching in the conversion of the phosphor, and the light emitting device hardly emits light. For example, when the external environment changes and the temperature of the phosphor particles significantly increases, the light emitting device may not emit light. In graphs (c) and (e) of FIG. 6, when the thickness of the wavelength conversion member 40 is 35 μm or less, the peak temperature of the surface temperature of the wavelength conversion member 40 is 150 ° C. or less. Therefore, in the light emitting device 101 according to the present embodiment, the thickness of the wavelength conversion member 40 may be 35 μm or less so that the wavelength conversion element 1 can stably emit high-luminance white light.

  On the other hand, as for the graphs (d) and (f) of FIG. 6, similarly to the graphs (c) and (e) of FIG. 6, the luminous intensity of the emitted light 95 when the configuration of the wavelength conversion member 40 is changed. FIG. 6 is a diagram illustrating a chromaticity change.

  As described above, the target of the chromaticity coordinates of the white light is (0.317, 0.327). Therefore, the range where the x value of the chromaticity coordinates is 0.30 or more and 0.35 or less, which is a correlated color temperature close to the white light of the target, is set as the target range. Regarding the x value, the smaller the thickness of the wavelength conversion member 40, the lower the x value of the chromaticity coordinates, and the larger the thickness, the higher the x value. That is, as the thickness of the wavelength conversion member 40 decreases, the white light becomes more pale, and as the thickness increases, the white light becomes more yellowish. This is because when the thickness of the wavelength conversion member 40 is reduced, the excitation light 84 is emitted without being sufficiently converted into fluorescence by the wavelength conversion member 40, so that the ratio of the first emission light 85 in the emission light 95 is reduced. This is because the ratio becomes higher than the ratio of the second emission light 91. On the other hand, when the thickness of the wavelength conversion member 40 is increased, the excitation light 84 is mostly converted into fluorescence by the wavelength conversion member 40, so that the ratio of the second emission light 91 to the first This is because the ratio of the outgoing light 85 becomes higher.

  The first emission light 85 emitted from the wavelength conversion member 40 is light that is emitted after the excitation light 84 is irregularly or multiplely reflected at the interface between the first phosphor particles 41 and the transparent coupling material 42. In addition, a part of the first emission light 85 includes the excitation light 84 which reaches the reflection member 3 in the process of irregular reflection or multiple reflection and is reflected. As shown in graphs (d) and (f) of FIG. 6, when the thickness of the wavelength conversion member 40 exceeds 15 μm, the chromaticity x of the chromaticity coordinates of the emitted light 95 with respect to the thickness of the wavelength conversion member 40 increases. Rate will be slow. This is presumably because the ratio of the excitation light 84 that does not reach the reflecting member 3 in the process of irregular reflection or multiple reflection of the first emission light 85 becomes dominant.

  On the other hand, when the thickness of the wavelength conversion member 40 is smaller than 15 μm, the chromaticity x of the chromaticity coordinates of the emitted light 95 sharply decreases as the thickness decreases. This is because the excitation light 84 is emitted from the light emitting region 151 with almost no irregular reflection and multiple reflection inside the wavelength conversion member 40. Therefore, in order to stably adjust the chromaticity coordinates of the output light 95, the thickness of the wavelength conversion member 40 may be 15 μm or more.

  As described above, the range in which the x value of the chromaticity coordinates is 0.30 or more and 0.35 or less is set as the target range. In order to realize this target range, the thickness of the wavelength conversion member 40 may be 15 μm or more, as shown in graphs (d) and (f) of FIG.

  As a result of the above examination, the film thickness in the central region 6b of the wavelength conversion member 40 is in the range of 15 μm or more and 35 μm or less from the viewpoint of the surface temperature of the wavelength conversion member 40 and the viewpoint of the chromaticity of the emitted light 95. You may. When the median diameter D50 of the first phosphor particles 41 is set to 3 μm or more and 9 μm or less as shown in graphs (c) to (f) of FIG. 6, the film thickness of the wavelength conversion member 40 is set to 15 μm or more and 35 μm or less. Can be set in a range. Further, the total volume (that is, volume ratio) of the first phosphor particles 41 can be set to be 38% or more and 62% or less with respect to the volume of the wavelength conversion member 40. At this time, in the cross section of the wavelength conversion member 40 as shown in FIG. 3, the total cross-sectional area of the first phosphor particles 41 is about 40% or more and about 80% or less with respect to the cross-sectional area of the wavelength conversion member 40.

The effect of the above embodiment will be described with reference to FIG. FIG. 7 is a graph showing a measurement result of luminance of emitted light 95 emitted from wavelength conversion member 40 according to the present embodiment. The graph (a) in FIG. 7 shows the result of measuring the relationship between the drive current applied to the semiconductor light emitting device 110 used to emit the excitation light 84 and the luminance peak value in the emission area of the emission light 95. Further, in the graph (a) of FIG. 7, the wavelength conversion member 40 having a film thickness of 42 μm is used together with the result of the light emitting device using the wavelength conversion member 40 having a film thickness of 20 μm according to the present embodiment. 9 shows the results of the light emitting device of the comparative example. In this measurement, the wavelength conversion element 1 is irradiated with the excitation light 84 having a peak wavelength of 446 nm at an ambient temperature (Ta) of 25 ° C. and an optical output of about 3.2 watts at a drive current (I _f ) of 2.3 A. did.

In the light emitting device of the comparative example, the luminance peak value is saturated at a drive current of about 2 amps. That is, when the driving current is about 2 amperes or more, the luminance peak value hardly increases even if the driving current is increased. As described above, in the light emitting device of the comparative example, when the power of the excitation light 84 increases with the driving current, the surface temperature of the wavelength conversion member 40 and the temperature of the first phosphor particles 41 of the wavelength conversion member 40 increase. It is considered that the conversion efficiency of the first phosphor particles 41 sharply decreases. On the other hand, in the wavelength conversion element 1 of the present embodiment, even when the driving current is 2 amperes or more, the luminance peak of the emitted light 95 increases as the driving current increases, and a light emitting device exceeding the peak luminance of 1000 cd / mm ² can be realized. . The graph (b) of FIG. 7 shows a luminance distribution in the light emitting region 151 of the wavelength conversion element 1 when the driving current is 2.3 amps. As shown in the graph (b) of FIG. 7, the width of the light emitting region 151 is about 0.8 mm, and the luminance of the emitted light 95 is 1000 cd / mm ² or more in the high luminance region of the luminance distribution. In addition, a luminance of 1000 cd / mm ² or more and a flat region can be obtained with a width of 0.2 mm or more. That is, a light-emitting device having a light-emitting region 151 with a flat luminance distribution and high luminance can be realized.

  Next, an example of the surface shape of the wavelength conversion element 1 will be described in detail with reference to FIG. FIG. 8 is a graph showing measurement results of respective surface shapes when the wavelength conversion member 40 of the wavelength conversion element 1 according to the first embodiment is manufactured by three different methods. The graph (a1) in FIG. 8 shows that the opening of the screen mesh print mask is a circular opening with a diameter of 2.6 mm, the thickness is 62 μm, and the volume ratio between the first phosphor particles 41 and the transparent binder 42 is 60%. : 40% phosphor paste was printed. The graph (b1) in FIG. 8 shows that the opening of the screen mesh print mask is a circular opening having a diameter of 2.6 mm, the thickness is 41 μm, and the volume ratio between the first phosphor particles 41 and the transparent binder 42 is 60%. : 40% phosphor paste printed. The graph (C1) in FIG. 8 shows that the opening of the screen mesh printing mask is a rectangular opening having a width of 3.4 mm, the thickness is set to 62 μm, and the volume ratio between the first phosphor particles 41 and the transparent binder 42 is 40%. : Printed as 60%. Graphs (a2), (b2), and (c2) in FIG. 8 are graphs obtained by adding a scale to indicate the sizes of the graphs (a1), (b1), and (c1), respectively, and tracing them.

  The mesh used here may be, for example, a mesh formed of a material not containing Fe. When printing is performed using a mesh formed of a material containing Fe, fine powder of Fe is mixed into the wavelength conversion member, and a part of the first emission light or the second emission light is absorbed, and the efficiency is reduced. By using a mesh formed of a material containing no Fe, the above-described decrease in efficiency can be suppressed.

  In the results shown in the graphs (a1) and (a2) of FIG. 8, the thickness of the central region of the wavelength conversion member 40 is 44 μm, and the wavelength conversion member 40 has a convex shape in which the central region is thicker than the peripheral region. In this case, although the change in the thickness of the wavelength conversion member 40 near the light emitting region is small as described above, the temperature of the wavelength conversion member 40 increases due to the large thickness, and it is difficult to increase the brightness of the light emitting device.

  According to the results shown in the graphs (b1) and (b2) of FIG. 8, the wavelength conversion member 40 has a film thickness in the central region of about 20 μm or more and 24 μm or less, and can suppress the temperature rise of the wavelength conversion member 40. However, since the film thickness may change in the range of 20 μm to 24 μm in the light emitting region, chromaticity unevenness of the light emitting region of the emitted light may occur.

  On the other hand, in the results shown in the graphs (c1) and (c2) in FIG. 8, the film thickness in the central region of the wavelength conversion member 40 is 18 μm, and the film thickness in the peripheral region is 24 μm. Thus, the wavelength conversion member 40 has a concave shape. For this reason, the thickness of the central region of the wavelength conversion member 40 can be set to 35 μm or less, and the change in the thickness of the central region can be suppressed. Therefore, by suppressing the temperature rise of the wavelength conversion member 40 in the light emitting region, the excitation light can be sufficiently converted into fluorescence, and the chromaticity unevenness of the emitted light in the light emitting region can be suppressed.

  Further, in the present embodiment, in the wavelength conversion element 1 in which the wavelength conversion member 40 is fixed on the support member 2, the linear expansion coefficients of the support member 2 and the wavelength conversion member 40 are different. In such a case, when the wavelength conversion member 40 is thicker, the stress applied to the wavelength conversion member 40 due to the temperature change of the wavelength conversion element 1 is reduced, and the wavelength conversion member is prevented from peeling off from the support member. be able to. In the graphs (b1), (b2), (c1), and (c2) of FIG. 8, fluorescence is emitted, and the thickness of the wavelength conversion member 40 is large around the central region where the thickness of the wavelength conversion member 40 is small. A peripheral part is provided. For this reason, peeling of the wavelength conversion member 40 from the support member 2 can be suppressed in response to a change in the environmental temperature of the wavelength conversion element 1 or a change in the temperature when the wavelength conversion element 1 emits light. That is, in the wavelength conversion element 1 according to the present embodiment, the mechanical strength can be increased. Further, by increasing the thickness of the peripheral region 6a, the heat radiation efficiency from the central region 6b where the temperature becomes relatively high to the peripheral region 6a can be increased.

  Therefore, as the shape of the wavelength conversion member 40, a concave shape having a small film thickness in the central region as shown in graphs (c1) and (c2) of FIG. 8 is optimal. Further, in the wavelength conversion element 1 shown in the graphs (c1) and (c2) in FIG. 8, the film thickness of the wavelength conversion member 40 including the peripheral region is 35 μm or less. Therefore, no matter where the wavelength conversion member 40 is irradiated with the excitation light 84, the temperature rise of the wavelength conversion member 40 can be suppressed. For this reason, even when the excitation light 84 is irradiated to a portion other than the central region of the wavelength conversion member 40 when adjusting the position of the excitation region irradiated with the excitation light 84 at the time of manufacturing the light emitting device, the wavelength conversion member It is possible to suppress the deterioration caused by the temperature rise of the forty.

  The wavelength conversion member 40 as shown in the graphs (c1) and (c2) of FIG. 8 may be configured such that the volume ratio of the first phosphor particles 41 and the transparent binder 42 is appropriately determined according to the size of the wavelength conversion member. It can be realized by adjusting. Further, the direction of scanning of the squeegee in the fluorescent paste printing step also affects the shape of the wavelength conversion member 40. For example, in the wavelength conversion member 40 shown in the graphs (b1) and (b2) of FIG. 8, the squeegee is scanned from the left side to the right side in the drawing in the fluorescent paste printing step of forming the wavelength conversion member 40. For this reason, it is considered that the thickness of the right end of the wavelength conversion member 40 was the largest due to an increase in the amount of the phosphor paste at the end of the printing mask opening on the scanning end point side in the fluorescent paste printing step.

(Modification 1 of Embodiment 1)
Next, a wavelength conversion element according to a first modification of the first embodiment will be described with reference to the drawings. FIG. 9 is a schematic cross-sectional view illustrating a configuration of a wavelength conversion element 1B according to the present modification.

In the wavelength conversion element 1B according to the present modified example, the thickness d _c of the central region 6b of the wavelength conversion member 40B is in the range of 15μm or 35μm or less in the same manner as the first embodiment. On the other hand, in the present modification, only a part of the film thickness of the peripheral region 6a of the wavelength conversion member 40B is thicker than the film thickness of the central region 6b. Maximum Specifically, in FIG. 9, the maximum thickness _{d e2} of the right edge region 6a as shown in FIG. 9 is larger than the thickness _{d c} of the center region _{(d e2>} d c), the left peripheral region 6a the film thickness is about the same as the thickness d _c of the central region 6b.

  According to this configuration, when the wavelength conversion element 1B is fixed to the storage section 50a of the light emitting device 101 as shown in FIG. 5 and the light shielding cover 51 is disposed, the light shielding cover 51 is placed in the central region 6b (or flat) of the wavelength conversion member 40. The contact with the portion F1) can be suppressed.

  The wavelength conversion element 1B having such a configuration can be manufactured by adjusting the shape of the screen mesh print mask and the scanning condition of the squeegee as shown in graphs (b1) and (b2) of FIG. .

(Modification 2 of Embodiment 1)
Subsequently, a wavelength conversion element, a light emitting device, and a lighting device according to a second modification of the first embodiment will be described with reference to the drawings. The wavelength conversion element, the light emitting device, and the lighting device according to the present modification have different configurations from the wavelength conversion element 1, the light emitting device 101, and the lighting device 201 shown in FIG. FIG. 10 is a schematic diagram illustrating a configuration of a light emitting device 101B and a lighting device 201B according to the present modification. FIG. 11 is a top view illustrating a configuration of a wavelength conversion element 1C of the present modification.

  The illuminating device 201B mainly includes a light emitting device 101B that emits outgoing light 95 that is white light, a light projecting member 220, dichroic mirrors 314B and 314R, three image display elements 350B, 350G and 350R, and a projection device. A lens 365. The illumination device 201B further includes a reflection mirror 331R, 332R, 331B, and 332B, and a dichroic prism 360.

  The light projecting member 220 converts the outgoing light 95 into projection light 96 that is parallel light. The dichroic mirror 314B is a mirror that reflects only blue light and transmits green light and red light in the projection light 96 that is white light. The dichroic mirror 314B is a mirror that reflects only red light and transmits green light among green light and red light transmitted through the dichroic mirror 314B.

  The image display elements 350B, 350G, and 350R are optical elements that superimpose blue, green, and red video information, respectively. In the present embodiment, each image display element includes a liquid crystal panel element.

  The reflection mirrors 331R and 332R are mirrors that reflect red light. The reflection mirrors 331B and 332B are mirrors that reflect blue light. The dichroic prism 360 is an optical element that multiplexes and outputs incident blue light, green light, and red light.

  The projection lens 365 is a lens that projects the combined light 385 incident from the dichroic prism 360.

  The light emitting device 101B mainly includes a light source unit 320, a condensing optical member 120, and a wavelength conversion element 1C. The light source unit 320 includes a heat sink 325 and a plurality of excitation light sources arranged on the heat sink. In the present modified example, the light source unit 320 includes, for example, three semiconductor light emitting devices 110 as a plurality of excitation light sources, as shown in FIG. Each of the three semiconductor light emitting devices 110 is, for example, a nitride semiconductor laser device having an optical output of 4 watts and a center wavelength of an emission wavelength near 445 nm. The semiconductor light emitting device 110 is a device in which a nitride semiconductor laser element is mounted on a TO-CAN package. The semiconductor light emitting device 110 further includes a lens 120a that is a collimating lens fixed to a TO-CAN package.

  Outgoing light emitted from the nitride semiconductor laser element of the semiconductor light emitting device 110 becomes collimated light by the lens 120a and enters the condenser lens 120c. Then, the excitation light 84 having a total optical output of 12 watts collected by the condenser lens 120c travels toward the wavelength conversion element 1C. As described above, the light collecting optical member 120 includes the lens 120a and the light collecting lens 120c.

  The wavelength conversion element 1C is a phosphor wheel in the present modification, and has a disk-shaped support member 2 made of an aluminum alloy plate, for example, as shown in FIG. Then, a wavelength conversion member 40C is formed in a ring shape on the outer peripheral region of the support surface 2a of the support member 2.

In the wavelength conversion member 40C, for example, first phosphor particles made of Ce-activated Y ₃ (Al, Ga) ₅ O ₁₂ phosphor are mixed and fixed to a transparent binder 42 such as silsesquioxane. In addition, as for the wavelength conversion element 1C shown in FIG. 10, a cross section of the wavelength conversion element 1C along the line XX in FIG. 11 is shown.

  At this time, the thickness of the wavelength conversion member 40C of the wavelength conversion element 1C is 15 μm or more and 35 μm or less in the excitation region 150 irradiated with the excitation light 84 as described in the first embodiment. The maximum thickness of the peripheral region of the wavelength conversion member 40C is larger than the thickness of the central region. Here, the peripheral region of the wavelength conversion member 40C includes a ring-shaped region including the inner peripheral edge 40i of the ring-shaped wavelength conversion member 40C illustrated in FIG. 11 and a ring-shaped region including the outer peripheral edge 40e. The central region is a region between the peripheral region including the inner peripheral edge 40i and the peripheral region including the outer peripheral edge 40e.

  Also in this modification, the wavelength conversion member 40C may have a configuration in which the film thickness of the entire region is in the range of 15 μm or more and 35 μm or less, and the central region of the wavelength conversion member 40C is thinner than the peripheral region.

  The rotation shaft 191 of the rotation mechanism 190 is connected to the center of the support member 2 of the wavelength conversion element 1C having such a configuration. During the operation of the light emitting device 101B, the wavelength conversion element 1C rotates with the rotation of the rotation mechanism 190. Then, the excitation light 84 is focused on the excitation area 150 of the wavelength conversion member 40C by the condenser lens 120c. At this time, the excitation light 84 condensed on the wavelength conversion member 40C is combined with the first emission light 85 that is the excitation light 84 scattered by the first phosphor particles 41 and the transparent binder 42 included in the wavelength conversion member 40C. The light emitted from the light emitting device 101B is emitted as emission light 95, which is white light mixed with the second emission light 91, which is the fluorescence whose wavelength has been converted by the first phosphor particles 41.

  In this configuration, the wavelength conversion element 1C prevents the rotation mechanism 190 from continuously irradiating the excitation light 84 to a specific position of the wavelength conversion member 40C. As a result, even when the wavelength conversion member 40C is irradiated with the strong excitation light 84, the temperature rise in the light emitting region can be suppressed, so that the emission light 95 with higher luminance can be emitted.

  The outgoing light 95 is converted into projection light 96 as parallel light by the light projecting member 220 as a condenser lens, and is converted into projection light 389 as image light by the following operation inside the illumination device 201B. First, the projection light 96 is separated by the dichroic mirror 314B into a blue light 379B having a main wavelength band of 430 nm or more and 500 nm or less, and a yellow light 379Y as the remaining light. The blue light 379B is reflected by the reflection mirrors 331B and 332B, passes through a polarizing element (not shown), becomes polarized light, and enters the image display element 350B. On the other hand, the yellow light 379Y is separated by the dichroic mirror 314R into a green light 379G having a main wavelength band of 500 nm to 580 nm and a red light 379R having a main wavelength band of 580 nm to 660 nm. The red light 379R is reflected by the reflection mirrors 331R and 332R, passes through a polarizing element (not shown), becomes polarized light, and enters the image display element 350R. The green light 379G is polarized by transmitting through a polarizing element (not shown) and enters the image display element 350G. The blue light 379B, the green light 379G, and the red light 379R that have entered the image display elements 350B, 350G, and 350R respectively are signal light on which video information is superimposed by each image display element and a polarizing element (not shown) on the emission side thereof. 380B, 380G and 380R. The signal lights 380B, 380G, and 380R are applied to the dichroic prism 360 and combined to form a combined light 385. By passing the combined light 385 through a projection lens, projection light 389, which is video light, can be obtained.

In the above configuration, the excitation light 84 emitted from the semiconductor light emitting device 110 and applied to the wavelength conversion member 40C has an optical output of 10 W or more, and is applied to an area of the excitation area 150 having an area of 1 mm ² or less. At this time, the light density of the excitation light in the excitation region 150 is set so that the light density peak is at least 17 W / mm ² or more. Here, the thickness of the wavelength conversion member 40C in the light emitting region 151 is in a range of 15 μm or more and 35 μm or less. As described above, according to such a wavelength conversion member 40C, since the excitation light 84 can be converted into the emission light 95 while suppressing a temperature rise, the conversion can be performed at a conversion efficiency of 200 lm / W, for example. Therefore, it is possible to easily realize a light emitting device that emits the emission light 95 having a luminance peak of 1000 cd / mm ² or more.

  As described above, in a light emitting device that converts light emitted from a semiconductor light emitting device such as a semiconductor laser device using a phosphor and emits the light, the saturation of the conversion efficiency in the phosphor is suppressed, and a high-luminance light emitting device is obtained. Can be provided.

(Embodiment 2)
Next, a wavelength conversion element according to the second embodiment will be described. The wavelength conversion element according to the present embodiment differs from the wavelength conversion element 1 according to the first embodiment in that the wavelength conversion member includes scattering particles other than the first phosphor particles. Hereinafter, the wavelength conversion element according to the present embodiment will be described with reference to the drawings, focusing on differences from the wavelength conversion element 1 according to the first embodiment.

  FIG. 12 is a schematic sectional view showing the configuration of the wavelength conversion element 1D according to the present embodiment. The wavelength conversion member 40D of the wavelength conversion element 1D according to the present embodiment includes, in addition to the first phosphor particles 41 and the transparent binder 42, a plurality of scattering particles bound to the transparent binder 42.

In the wavelength conversion member 40D, as the first phosphor particles 41, the median diameter D50 is less 30μm or 2 [mu] m, for example _{(Y x Gd 1-x)} 3 (Al y Ga 1-y) 5 O 12: Ce (0. A phosphor such as 5 ≦ x ≦ 1, 0.5 ≦ y ≦ 1) is used. As the transparent binder 42 that binds the first phosphor particles 41, for example, a transparent material such as dimethyl silicone, silsesquioxane, or low-melting glass can be used. As the silsesquioxane, for example, polymethylsilsesquioxane or the like can be used. Further, as the scattering particles 43, non-emitting particles composed of a material having a median diameter D50 of 0.3 μm or more and 18 μm or less and having little absorption for excitation light and fluorescence are mixed.

As the scattering particles 43, for example, a transparent material having a high thermal conductivity and a large difference in refractive index from the transparent binder 42 is used. The scattering particles may include metal oxides or nitrides. Specifically, the scattering particles 43 are formed of Al ₂ O ₃ , TiO ₂ , ZrO ₂ , ZnO, BN, or the like. The volume ratio of the scattering particles 43 to the first phosphor particles 41 is, for example, 10 vol% or more and 90 vol% or less.

The thickness of the wavelength conversion member 40D, as in the first embodiment, the thickness d _c of the center region is thinner than the maximum thickness d _e of the peripheral region, the wavelength conversion member 40D, the film thickness of the entire area 15μm The range is at least 35 μm.

  Further, a void 45 may be provided inside the wavelength conversion member 40D. In the present embodiment, voids 45 are formed inside the wavelength conversion member 40D and near the interface between the wavelength conversion member 40D and the reflection member 3.

  In the wavelength conversion element 1D thus configured, the chromaticity coordinates of the emitted light 95 can be freely designed according to the spectrum of the excitation light 84. Specifically, by changing the ratio between the first phosphor particles 41 and the scattering particles 43 of the wavelength conversion member 40D according to the spectrum of the excitation light 84, the chromaticity of each light emitting device using the wavelength conversion element 1D is changed. Coordinates can be adjusted. In other words, even if the spectrum of the excitation light 84 varies for each semiconductor light emitting device due to the structural variation of the semiconductor light emitting device that emits the excitation light 84, the scattering included in the first phosphor particles 41 according to the spectrum of the excitation light 84. The chromaticity coordinates can be adjusted by adjusting the ratio of the particles. Hereinafter, the wavelength conversion element 1D of the present embodiment will be described in detail with reference to FIGS.

In the wavelength conversion member 40D of the wavelength conversion element 1D of the present embodiment, the first median diameter D50 as the phosphor particles 41 is 6μm of _Y 3 _Al 5 _O 12: Ce phosphor is used. Then, polymethylsilsesquioxane is used as the transparent binder 42 for fixing the first phosphor particles 41. Al ₂ O ₃ particles having a median diameter D50 of 3 μm are mixed as the scattering particles 43 which are non-light emitting particles. The refractive index of Al ₂ O ₃ is 1.77, and the refractive index difference from silsesquioxane having a refractive index of 1.5 is large. The thermal conductivity of Al ₂ O ₃ is as high as 30 W / mK. With this configuration, the light scattering property inside the wavelength conversion member 40D can be improved, and the thermal conductivity of the wavelength conversion member 40D can be increased.

In the present embodiment, a void 45 may be further formed inside the wavelength conversion member 40D. Such a void 45 is used when the first phosphor particles 41 made of Y ₃ Al ₅ O ₁₂ : Ce and the transparent binder 42 made of polysilsesquioxane are mixed to form a phosphor paste. Compared with the first phosphor particles 41 and the scattering particles 43, the structure can be easily achieved by reducing the ratio of the transparent binder 42 and curing at a high temperature.

  Specifically, the ratio Vb / (Vf + Vs) of the volume Vb of the transparent binder 42, which is silsesquioxane, to the total volume (Vf + Vs) of the volume Vf of the first phosphor particles 41 and the volume Vs of the scattering particles 43. Is set to 40% or less. Then, a phosphor paste composed of a mixture of the transparent binder 42, the first phosphor particles 41, and the scattering particles 43 dissolved in the organic solvent is formed on the support member 2, and then high-temperature annealing at about 200 ° C. is performed. Thus, the organic solvent in the paste is vaporized.

  The cross-sectional structure of the wavelength conversion element 1D manufactured by the above method will be described with reference to FIG. FIG. 13 is a photograph obtained by observing a cross section of the wavelength conversion element 1D according to the present embodiment with a scanning electron microscope. FIG. 3 shows a cross-sectional photograph (a) and an enlarged photograph (b) of a part thereof. The enlarged photograph (b) is an enlarged photograph of a broken-line frame portion of the sectional photograph (a).

  As shown in FIG. 13, a reflection member 3 is formed on a support member 2 which is a silicon substrate, and a wavelength conversion member 40D is fixed thereon. The thickness of the wavelength conversion member 40D is 24 μm, and the first phosphor particles 41 and the scattering particles 43 are dispersed in the transparent binder 42 inside the wavelength conversion member 40D. Further, voids 45 are scattered inside the wavelength conversion member 40D and at the interface with the reflection member 3. As described above, according to the manufacturing method of the present embodiment, the wavelength conversion member 40D in which the first phosphor particles 41 and the scattering particles 43 are dispersed and the voids 45 are interspersed inside the transparent binder 42 can be easily formed. realizable.

  According to the wavelength conversion element 1D, the excitation light 84 that has entered the inside of the wavelength conversion member 40D can be more efficiently scattered and extracted from the wavelength conversion member 40D. In addition, since a part of the void 45 is in contact with the second reflection film 3c of the reflection member 3 which is a dielectric, the excitation light is effectively reduced while reducing the energy loss due to the excitation light and the fluorescence entering the metal surface. , Can scatter fluorescence.

  Further, the wavelength conversion member 40D of the present embodiment includes scattering particles 43 which are non-light emitting particles. The chromaticity coordinates of the emitted light 95 can be easily adjusted by changing the volume ratio of the scattering particles 43 in the wavelength conversion member 40D.

  Since the semiconductor light emitting device, which is a semiconductor laser device composed of a nitride semiconductor, has a slight individual difference in the wavelength of the emitted light, the light emitting device using the semiconductor light emitting device has an individual difference in the chromaticity of the emitted light. Can occur. Therefore, a method of adjusting the chromaticity of emitted light by changing the ratio between the first phosphor particles 41 and the scattering particles 43 in the wavelength conversion member 40D in which the scattering particles 43 are mixed will be described with reference to FIGS. explain.

  FIG. 14 is a graph showing a spectrum of emission light 95 when the wavelength conversion element 1D according to the present embodiment is irradiated with excitation light 84 having a peak wavelength of 447 nm. The first emission light 85 has a sharp peak at a wavelength of 447 nm, and the second emission light 91 has a broad peak from a wavelength of 500 nm to 700 nm. In FIG. 14, in order to show the spectral characteristics of the second emission light 91, the spectrum 10 times the intensity of the second emission light 91 is shown by a broken line.

FIG. 15 is a graph showing a change in the chromaticity coordinates of the emitted light 95 when the ratio between the first phosphor particles 41 and the scattering particles 43 is changed in the wavelength conversion element 1 according to the present embodiment. . At this time, YAG: Ce phosphor particles having a median diameter D50 of 6 μm were used as the first phosphor particles 41, and Al ₂ O ₃ particles having a median diameter D50 of 3 μm were used as the scattering particles. Silsesquioxane was used as the transparent binder 42. The ratio Vb / (Vf + Vs + Vb) of the volume Vb of the transparent binder 42 to the sum of the volume Vf of the first phosphor particles 41, the volume Vs of the scattering particles 43, and the volume Vb of the transparent binder 42 was 35%. . Then, six types of wavelength conversion elements 1D in which the volume ratio Vf / (Vf + Vs) between the first phosphor particles 41 and the scattering particles 43 are 76%, 73%, 69%, 65%, 61% and 51%, respectively. Was prepared. Then, laser light having a peak wavelength of 447 nm was irradiated as excitation light 84 to each wavelength conversion element 1D, and the chromaticity coordinates of the emitted light 95 were plotted in FIG. The solid line shown in FIG. 15 indicates the locus of blackbody radiation.

  As a result, by increasing the ratio of the first phosphor particles 41, the chromaticity coordinates x and y can be increased, that is, shifted to white light close to yellow. By increasing the number of the scattering particles 43, the chromaticity coordinates x and y can be reduced, that is, shifted to white light close to blue. Now, when the chromaticity coordinates (0.317, 0.327) are set as the target of the chromaticity coordinates, the volume ratio between the first phosphor particles 41 and the scattering particles 43 is set to 61%, so that the desired chromaticity coordinates can be obtained. Outgoing light can be obtained. Therefore, the chromaticity coordinates of the emitted light can be easily set to the predetermined chromaticity coordinates by changing the volume ratio between the first phosphor particles 41 and the scattering particles 43.

  Further, in the wavelength conversion element 1D of the present embodiment, by adjusting the structure according to the peak wavelength of the excitation light 84, the chromaticity coordinates of the light emitted from the light emitting device can be adjusted. This adjustment method will be described with reference to FIG.

  FIG. 16 is a graph showing the results of measuring the peak wavelength dependence of the excitation light on the chromaticity coordinates of the emitted light 95 in the wavelength conversion element 1D according to the present embodiment. At this time, in the wavelength conversion element 1D, the volume ratio Vf / (Vf + Vs) of the first phosphor particles 41 and the scattering particles 43 is 76%, 73%, 69%, 65%, and 61%, as shown in FIG. , 51%, and the change of the chromaticity coordinate y was plotted using the peak wavelength of the excitation light 84 of 438 nm, 441 nm, 444 nm, 447 nm, and 451 nm.

  As shown in FIG. 16, for example, when the chromaticity y of the chromaticity coordinates is set to 0.327, even if the peak wavelength of the excitation light changes from about 440 nm to about 447 nm, the ratio of the scattering particles 43 is reduced. By changing the chromaticity coordinates, the chromaticity coordinates of the emitted light can be set to predetermined chromaticity coordinates.

  Further, in the present embodiment, the effect of scattering light can be enhanced by increasing the difference in the refractive index between the transparent binder and the first phosphor particles and the scattering particles. Thereby, propagation of light inside the wavelength conversion member 40D can be suppressed. As a result, the emitted light 95 can be emitted from the light emitting region 151 having substantially the same area as the excitation region 150. In the present embodiment, the scattering of light is enhanced by forming a void 45 in the wavelength conversion member 40D. As a result, the area of the light emitting region 151 can be made closer to the area of the excitation region 150.

In the present embodiment, as in the first embodiment, in the luminance distribution of the outgoing light 95 on the radiation surface 6, a light emitting region 151 having a luminance of 200 cd / mm ² or more exists over a width of about 0.7 mm. That is, the same light emitting region 151 as the excitation region 150 can be realized. In the vicinity of the peak, a region having a luminance of 1000 cd / mm ² or more and a uniform width over a width of 0.2 mm or more can be realized.

(Embodiment 3)
Subsequently, a wavelength conversion element and a light emitting device according to Embodiment 3 will be described. The wavelength conversion element and the light emitting device according to the present embodiment differ from those of Embodiments 1 and 2 in the material constituting the wavelength conversion member, and are identical in other points. Hereinafter, the wavelength conversion element and the light emitting device according to the present embodiment will be described with reference to the drawings, focusing on differences from the first and second embodiments.

In the present embodiment, as the material constituting the first phosphor particles 41 contained in the wavelength conversion member _{40, (La x Y 1-} x) 3 Si 6 N 11: Ce (0.5 ≦ x ≦ 1) Is used. FIG. 17 is a diagram illustrating the refractive index and the thermal conductivity of a material that can form the wavelength conversion member 40. FIG. 17 shows the refractive index for light having a wavelength of 550 nm. Among the materials shown in FIG. 17, as the phosphor material, a phosphor which absorbs blue light having a wavelength of about 430 nm to 470 nm and emits yellow fluorescence having a wavelength range of about 520 nm to 650 nm was examined. _{Specifically, (Y x Gd 1-x} ) 3 (Al y Ga 1-y) 5 O 12: a phosphor represented by Ce (0.5 ≦ x ≦ 1,0.5 ≦ y ≦ 1) _{, (La x Y 1-x} ) 3 Si 6 N 11: a phosphor represented by Ce (0.5 ≦ x ≦ 1) , (Ba x Sr 1-x) SiO 4: Eu (0 ≦ x ≦ 1 a phosphor represented _{by), (Ba x Sr 1-} x) Si 2 O 2 N 2: comparing the phosphor represented by Eu (0 ≦ x ≦ 1) . Among these phosphors in FIG. _{17, (Y x Gd 1-} x) 3 (Al y Ga 1-y) 5 O 12: Ce (0.5 ≦ x ≦ 1,0.5 ≦ y ≦ 1) Y ₃ Al ₅ O ₁₂ which is a central base material of the phosphor material represented by: and a phosphor material represented by (La _x Y _1-x ) ₃ Si ₆ N ₁₁ : Ce (0.5 ≦ x ≦ 1) La ₃ Si ₆ N ₁₁ which is the central base material of the above is shown. As the material used as the scattering particles 43, Al ₂ O ₃ , TiO ₂ , ZnO and BN are shown. Silsesquioxane, dimethyl silicone, and low-melting glass are shown as materials used as the transparent binder 42. As a material constituting the wavelength conversion member, a material having high thermal conductivity may be used. Further, in order to suppress that the excitation light incident on the wavelength conversion member 40 propagates in the wavelength conversion member 40 in the lateral direction, the difference in the refractive index between the phosphor particles and the transparent binder, the scattering particles and the transparent binder May be large. From this viewpoint, the phosphor material may be either a Y ₃ Al ₅ O ₁₂ : Ce phosphor or a La ₃ Si ₆ N ₁₁ : Ce phosphor. The scattering particles may be any of Al ₂ O ₃ , ZnO, and BN.

Hereinafter, characteristics of the wavelength conversion member according to the present embodiment will be described with reference to FIGS. FIG. 18 shows the temperature of the quantum efficiency between the La ₃ Si ₆ N ₁₁ : Ce phosphor used in the wavelength conversion member according to the present embodiment and the Y ₃ Al ₅ O ₁₂ : Ce phosphor used in the first embodiment. It is a figure which shows dependency. The quantum efficiency shown in FIG. 18 is the efficiency of irradiating a phosphor with an excitation wavelength of 450 nm and converting it into fluorescence. Note that FIG. 18 shows relative values when the quantum efficiency when the ambient temperature (Ta) is 25 ° C. is 100%, as the quantum efficiency. Compared with the Y ₃ Al ₅ O ₁₂ : Ce phosphor, La ₃ Si ₆ N ₁₁ : Ce has a smaller decrease rate of the quantum efficiency at a higher temperature. Therefore, La ₃ Si ₆ N ₁₁ : Ce used in the wavelength conversion member according to the present embodiment is more suitable as a material constituting the wavelength conversion member of a light emitting device having a high light density of excitation light.

FIG. 19 is a diagram illustrating characteristics of a light emitting device equipped with the wavelength conversion element according to the present embodiment. In the wavelength conversion element according to the present embodiment, (La _0.84 Y _0.16 ) ₃ Si ₆ N ₁₁ : Ce having a median diameter D50 of 9 μm is used as the first phosphor particles 41, and the median diameter D50 is 3 μm. Al ₂ O ₃ particles were used as the scattering particles 43. A wavelength conversion member 40 in which the first phosphor particles 41 and the scattering particles 43 are dispersed in a transparent binder 42 whose main component is silsesquioxane was used. The composition ratio of the first phosphor particles, the scattering particles, and the transparent binder is 18%: 22 in terms of volume ratio in the step of constructing the wavelength conversion member. %: Set to be 60%. Further, as the configuration of the wavelength conversion element 1 and the light emitting device 101 used when measuring the characteristics, the same configuration as that of the first embodiment shown in FIGS. 4 and 5 was used. The thickness of the wavelength conversion member 40 of the wavelength conversion element 1 was about 25 μm near the light emitting region 151.

  FIG. 19 is a graph in which the peak value of the luminance of the light emitting region 151 of the wavelength conversion member is plotted against the current applied to the semiconductor light emitting device 110 in the light emitting device 101 described above. At this time, the environmental temperature (Ta) of the light emitting device 101 was set to 85 ° C.

In FIG. 19, a light emitting device of a comparative example using a YAG: Ce phosphor as the first phosphor particles shown in FIG. 7 and using a wavelength conversion member having a film thickness of 42 μm operates at an ambient temperature (Ta) of 85 ° C. The characteristics in the case where they are performed are also shown. Similarly, the characteristics when the light emitting device according to Embodiment 1 using the YAG: Ce phosphor as the first phosphor particles and using the wavelength conversion member 40 having a thickness of 20 μm at an ambient temperature of 85 ° C. are also shown. It is shown. Compared with the comparative example, the light emitting device of Embodiment 1 has a high rate of increase in luminance with an increase in drive current even at a drive current of ^{2 A} or more, and a peak value of luminance reaches 800 cd / mm ² or more. However, even when the drive current was further increased, the rate of increase in luminance was reduced, and the luminance was saturated at less than 900 cd / mm ² . This is because the temperature of the wavelength conversion member 40 rises due to heat received from the environment by the wavelength conversion member 40 and heat generated when the excitation light 84 is converted into the second emission light 91, so that the quantum efficiency sharply increases. It is considered to be lower. On the other hand, in the wavelength conversion element according to the present embodiment, the first phosphor particles, decrease in quantum efficiency is small with respect to temperature increase _{(La x Y 1-x)} 3 Si 6 N 11: Ce (0 ≦ x ≦ 1) A phosphor is used. Therefore, the luminance reached 800 cd / mm ² or more at an ambient temperature of 85 ° C. and a driving current of 2 amps, and the luminance did not saturate even at a driving current of more than 900 cd / mm ² at a driving current of 2.3 amps. FIG. 20 is a graph showing a result of measuring the luminance distribution of the light emitting region 151 on the phosphor surface when the driving current of the semiconductor light emitting device 110 of the light emitting device 101 is 2.3 amps in the luminance measurement of FIG. is there. In FIG. 20, the luminance distribution when the environmental temperature is 25 ° C. is also shown by dotted lines. As shown in FIG. 20, the luminance distribution at an environmental temperature of 85 ° C. is about 20% lower than the luminance distribution at an environmental temperature of 25 ° C. This is mainly due to the temperature dependency of the semiconductor light emitting device, and not due to a decrease in the quantum efficiency of the wavelength conversion element. Therefore, it is possible to further increase the luminance by appropriately controlling the temperature of the semiconductor light emitting device. .

As described above, in this embodiment mode, a light-emitting device capable of high-temperature operation at high luminance with a peak luminance of 900 cd / mm ² or more even at an environmental temperature of 85 ° C. can be realized. Such a light emitting device is most suitable for a lighting device requiring high-temperature operation, for example, a headlight of a vehicle.

(Embodiment 4)
Next, a wavelength conversion element according to the fourth embodiment will be described. In a conventional light emitting device such as the light emitting device described in Patent Literature 1, the chromaticity coordinates of the emitted light are regulated by the type of the phosphor contained in the phosphor layer, so that the chromaticity coordinates of the emitted light are adjusted. Difficult to do. Therefore, in the present embodiment, a wavelength conversion element and a light emitting device that can increase the degree of freedom in adjusting the chromaticity coordinates of emitted light will be described.

  The wavelength conversion element according to the present embodiment is different from the wavelength conversion element according to the third embodiment in that the wavelength conversion member includes the second phosphor particles in addition to the first phosphor particles. Matches. Hereinafter, the wavelength conversion element according to the present embodiment will be described with reference to FIGS.

  FIG. 21 is a schematic cross-sectional view illustrating a configuration of a wavelength conversion element 1F according to the present embodiment. As shown in FIG. 21, a wavelength conversion element 1F according to the present embodiment includes a support member 2 having a support surface 2a, and a wavelength conversion member 40F disposed above the support surface 2a. Includes a plurality of first phosphor particles 41 that generate first fluorescence and a plurality of second phosphor particles 44 that generate second fluorescence having a spectrum different from that of the first fluorescence. The wavelength conversion member 40F further includes a transparent binding material 42 that couples the plurality of first phosphor particles 41 and the plurality of second phosphor particles 44, and a transparent binding material 42 that couples the plurality of first fluorescent particles. It includes body particles 41 and scattering particles 43 different from the plurality of second phosphor particles 44.

In the present embodiment, both the first phosphor particles 41 and the second phosphor particles 44 have the same basic composition formula with the median diameter D50 of 2 μm or more and 30 μm or less (that is, the same basic composition formula). And phosphor materials having different composition ratios. Note that, similarly to the first phosphor particles 41 according to Embodiment 1, the median diameter D50 of the first phosphor particles 41 and the second phosphor particles 44 may be 3 μm or more and 9 μm or less. Specific basic formula representative of the first phosphor particles 41 and the second phosphor particles 44, for _{example, (La x Y 1-x} ) 3 Si 6 N 11: in Ce (0.5 ≦ x ≦ 1) is there. That is, the plurality of first phosphor particles 41 include (La _1-x1 , Y _x1 ) ₃ Si ₆ N ₁₁ (0 ≦ x1 ≦ 1) with Ce activated, and the plurality of second phosphor particles 44 , Ce activated (La _1-x2 , Y _x2 ) ₃ Si ₆ N ₁₁ (0 ≦ x2 ≦ 1, x1 ≠ x2).

  Further, the wavelength conversion member 40F includes scattering particles 43 that are non-light emitting particles that do not absorb the excitation light. When the median diameter D50 of the scattering particles 43 is closer to the median diameter of each phosphor particle, the scattering efficiency of the scattering particles 43 is higher. Therefore, the median diameter D50 of the scattering particles 43 is, for example, not less than 0.3 μm and not more than 18 μm.

  Like the wavelength conversion element 1F according to the present embodiment, the wavelength conversion member 40F includes the first phosphor particles 41, the scattering particles 43, and the second phosphor particles 44 having a composition different from that of the first phosphor particles 41. Disperse. According to such a wavelength conversion member 40F, the chromaticity coordinates of the emitted light can be adjusted more freely by adjusting the mixing ratio of each particle.

Hereinafter, a specific configuration of the wavelength conversion element 1F of the present embodiment will be described. In the present embodiment, in the wavelength conversion member 40F, La ₃ Si ₆ N ₁₁ : Ce having a median diameter of 12 μm is used as the first phosphor particles 41, and (La) having a median diameter of 9 μm is used as the second phosphor particles 44. _0.84 Y _0.16 ) ₃ Si ₆ N ₁₁ : Ce was used. As the scattering particles 43, Al ₂ O ₃ having a median diameter D50 of 3 μm was used. As the transparent binder 42 for fixing the first phosphor particles 41, the second phosphor particles 44, and the scattering particles 43, a transparent material mainly containing polymethylsilsesquioxane was used.

  At this time, the ratio Vf / (Vf + Vf2) of the volume Vf of the first phosphor particles 41 to the volume Vf2 of the second phosphor particles 44 is larger than 0% and smaller than 100%. The ratio Vs / (Vf + Vf2 + Vs) of the volume Vs of the scattering particles 43 to the volume of the phosphor particles is 10% or more and 90% or less.

FIG. 22 is a graph showing the spectral characteristics of light emitted from a light emitting device using the wavelength conversion element 1F according to the present embodiment. As the first phosphor particles 41 and the second phosphor particles 44 of the wavelength conversion element 1F of the present embodiment, the same basic formula _{(La x Y 1-x)} 3 Si 6 N 11: Ce (0.5 ≦ x ≦ 1). For this reason, the second emission light 91, which is fluorescence having the same spectral shape as that of the first phosphor particles 41 and the second phosphor particles 44, is emitted from the wavelength conversion element 1F. Further, the relationship between the driving current ( _If ) of the semiconductor light emitting device and the luminance was almost the same as the relationship in the light emitting device according to the third embodiment indicated by white circles in FIG.

FIG. 23 is a diagram illustrating a change in chromaticity coordinates of emitted light when the configuration of the wavelength conversion element 1F is changed in the light emitting device equipped with the wavelength conversion element 1F according to the fourth embodiment. In the chromaticity diagram on the left side of FIG. 23, the chromaticity coordinates of the first outgoing light 85 which is the scattered light of the excitation light having the peak wavelength of 445 nm are indicated by reference numeral 85. The chromaticity coordinates of the fluorescence emitted from the first phosphor particles 41 composed of La ₃ Si ₆ N ₁₁ : Ce are indicated by reference numeral 91a. The chromaticity coordinates of the fluorescence emitted from the second phosphor particles 44 composed of (La _0.84 Y _0.16 ) ₃ Si ₆ N ₁₁ : Ce are indicated by reference numeral 91b. Therefore, the outgoing light 95 when the wavelength conversion member is composed of the first phosphor particles 41, the scattering particles 43, and the transparent binder 42 is plotted at any coordinate on the locus 195a. In the case where the wavelength conversion member is composed of the second phosphor particles 44, the scattering particles 43, and the transparent binder 42, the emitted light 95 is plotted at any coordinate on the locus 195b.

  23 is an enlarged view of the vicinity of the chromaticity coordinates (0.33, 0.33) of the chromaticity diagram on the left side.

  Here, as the configuration of the wavelength conversion member of the wavelength conversion element, the first phosphor particles, the second phosphor particles, the scattering particles, and the wavelength conversion elements (a) to (v) in which the volume ratio of the transparent binder is the following three types. c) was prepared and shown in the enlarged view on the right side of FIG.

(A) 18: 0: 22: 60
(B) 0: 18: 22: 60
(C) 9: 9: 22: 60

  At this time, the thickness of each of the wavelength conversion members in the light emitting region 151 was about 25 μm. The chromaticity coordinates of the emitted light 95 were measured by mounting the wavelength conversion element on the light emitting device 101 shown in FIG.

  The chromaticity coordinates 95a, 95b, and 95c in the enlarged view on the right side of FIG. 23 are the chromaticity coordinates of the outgoing light emitted from the wavelength conversion element corresponding to (a), (b), and (c), respectively. As described above, by using phosphors of the same basic color having different composition ratios and changing the mixing ratio, the chromaticity coordinates can be adjusted in a direction other than the locus connecting the excitation light and the fluorescence. That is, the chromaticity coordinates on the chromaticity diagram can be freely adjusted in the x-axis and y-axis directions by changing the ratio of the three types of particles, the first phosphor particles, the second phosphor particles, and the scattering particles. it can. That is, even when mass-producing the light emitting device, only three types of particles, the first phosphor particles, the second phosphor particles, and the scattering particles, need to be prepared in order to obtain desired chromaticity coordinates.

  More specifically, a region A shown in FIG. 23 is a region of the chromaticity of a vehicle headlight defined by Japanese Industrial Standard JIS D 5500. When manufacturing a light emitting device for this purpose, the first phosphor particles, the second phosphor particles, and the scattering particles are prepared, and the ratio thereof is adjusted to produce a wavelength conversion member and a wavelength conversion element. This makes it possible to freely obtain the chromaticity of the hatched area in the chromaticity area defined by the above-mentioned standard.

  Further, the scattering particles 43 included in the wavelength conversion member 40 also have the effect of improving the uniformity of the chromaticity of the emitted light in the light emitting region. That is, the first fluorescence emitted from the first phosphor particles 41 due to the presence of the scattering particles 43 and the second fluorescence emitted from the second phosphor particles 44 can be mixed by scattering. Therefore, emitted light having uniform chromaticity can be emitted from the light emitting region of the wavelength conversion member 40.

  With the above structure, it is possible to provide a light-emitting device that has high luminance of emitted light, high uniformity of chromaticity in a light-emitting region, and can easily adjust chromaticity.

Incidentally, in the wavelength conversion member 40F of the present embodiment, the first phosphor particles 41 and the second phosphor particles 44 median diameter D50 of 2μm or more 30μm following _{(La x Y 1-x)} 3 Si 6 N 11 : Ce (0.5 ≦ x ≦ 1) has been described, but is not limited thereto. Depending on the intensity and spectrum of the emitted light that is required for the light emitting device to be _{used, (Y x Gd 1-x} ) 3 (Al y Ga 1-y) 5 O 12: Ce (0.5 ≦ x ≦ 1, 0.5 ≦ y ≦ 1) can be used. In this case, a material other than silsesquioxane may be used as the transparent binder. For example, the transparent binder 42 is made of a material mainly composed of an inorganic substance such as SiO ₂ , Al ₂ O ₃ , ZnO, Ta ₂ O ₅ , Nb ₂ O ₅ , TiO ₂ , AlN, BN, and BaO. The wavelength conversion element 1 having high reliability can be realized. Further, the scattering particles 43 included in the wavelength conversion member 40F are not limited to Al ₂ O ₃ but may be fine particles such as SiO ₂ , TiO ₂ , and ZnO depending on the use of the light emitting device. In particular, by mixing fine particles of boron nitride (BN) or diamond having high thermal conductivity, the light scattering property of the wavelength conversion member 40F is enhanced, and heat from the phosphor material is efficiently transferred to the support member. Can be.

(Embodiment 5)
Subsequently, a light emitting device and a lighting device according to Embodiment 5 will be described. The light emitting device and the illuminating device according to the present embodiment irradiate excitation light while scanning the surface of the wavelength conversion member between the semiconductor light emitting device 110 and the wavelength conversion element 1 using a movable mirror unit. However, this is different from the light emitting device 101 and the lighting device 201 according to the first embodiment. Hereinafter, the light emitting device and the lighting device according to the present embodiment will be described with reference to the drawings, focusing on differences from light emitting device 101 and lighting device 201 according to the first embodiment.

  FIG. 24A is a schematic cross-sectional view illustrating a configuration of lighting device 201C according to the present embodiment.

  As shown in FIG. 24A, the lighting device 201C includes a light emitting device 101C, a light projecting member 220, and a fourth base 221. The light emitting device 101 </ b> C is a light source that emits the emission light 95 from the wavelength conversion element 1. The illuminating device 201 </ b> C converts the outgoing light 95 by the light projecting member 220 into the projection light 96, which is light having strong directivity, and emits the same.

  The light emitting device 101C includes the wavelength conversion element 1, the semiconductor light emitting device 110, and the lens 120a as in the first embodiment. In the present embodiment, light emitting device 101C includes movable mirror unit 520 in the optical path between lens 120a and wavelength conversion element 1.

  The movable mirror unit 520 includes a movable mirror 520a that is a mirror that can change at least one of a position and a posture, and a holder 520b that holds the movable mirror 520a by a support (not shown). The movable mirror 520a is fixed so that the mirror surface is parallel to the Dy1 direction inclined in the Dz direction with respect to the Dy direction shown in FIG. 24A. The support section is a support member, such as a torsion bar, extending in the Dy1 direction in FIG. 24A, and can tilt the movable mirror 520a in a direction rotating about the Dy1 direction as a central axis. The tilt angle of the movable mirror 520a with respect to the holder 520b can be changed by using electrostatic force or electromagnetic force between the movable mirror 520a and the holder 520b.

  The semiconductor light emitting device 110 is fixed to the second base 550, and the second base 550 is fixed to the base 50. The movable mirror unit 520 is fixed to the third base 540, and the third base 540 is fixed to the base 50.

  In the light emitting device 101C, a printed circuit board 160 is disposed on the bottom surface side of the base 50. The printed circuit board 160 is connected to the second printed circuit board 160b to which the semiconductor light emitting device 110 is connected, the wiring of the movable mirror unit 520, and the connector 170 for connection to an external circuit.

  The outgoing light emitted from the semiconductor light emitting device 110 is condensed by the lens 120a and becomes the outgoing light 83. The outgoing light 83 is reflected by the movable mirror 520a, and then is emitted as excitation light 84 to the wavelength conversion element 1.

  The excitation light 84 applied to the wavelength conversion element 1 is partly wavelength-converted into fluorescence by the wavelength conversion member 40 of the wavelength conversion element 1, and the second emission light 91 made of fluorescence and the second emission light 91 made of scattered light of the excitation light 84. The emitted light 95 is composed of one emitted light 85 and is emitted from the light emitting device 101C.

  The light emitting device 101C includes a connector 170. The connector 170 is a connector that can be connected to an external circuit. Power can be externally applied to the printed circuit board 160 connected to the movable mirror unit 520 and the semiconductor light emitting device 110 via the connector 170. Thus, by adjusting the power applied to the semiconductor light emitting device 110 and the movable mirror unit 520, the emission pattern of the emitted light 95 emitted from the wavelength conversion element 1 can be set more freely.

  The light projecting member 220 constituting the lighting device 201C is a lens in the present embodiment. The light projecting member 220 is held by the fourth base 221 and attached to the base 50 on the wavelength conversion element 1 side of the light emitting device 101C.

  Subsequently, an irradiation region of the wavelength conversion element 1 with the excitation light 84 will be described with reference to FIG. 24B. FIG. 24B is an enlarged sectional view of the wavelength conversion element 1 according to the present embodiment and the periphery thereof. FIG. 24B also shows a top view of the wavelength conversion member 40 of the wavelength conversion element 1 according to the present embodiment. Note that the enlarged cross-sectional view of FIG. 24B corresponds to a cross section taken along line XXIVB-XXIVB shown in the top view of FIG. 24B.

  The top view of FIG. 24B shows an irradiation area 84a of the excitation light 84 at a certain point in time. In the present embodiment, the irradiation area 84a can move, that is, scan, the irradiation area 84a in the Sx1 direction or the Sx2 direction by changing the tilt direction of the movable mirror 520a. By periodically scanning the irradiation area 84a for a time sufficiently shorter than the afterimage time of the human eye, the wavelength conversion element 1 can emit light as an apparent light emitting area of the scanning area 84w which is a scanning range. .

  At this time, by adjusting the power and timing applied to the semiconductor light emitting device 110 and the movable mirror unit 520 so that the excitation light 84 is not irradiated in a part of the scanning region 84w, an arbitrary In time, a region to be irradiated with the excitation light 84 and a region not to be irradiated can be set. That is, by turning off the power applied to the semiconductor light emitting device 110 in an arbitrary tilt direction of the movable mirror 520a, a non-irradiation region can be created.

  FIG. 24C is a schematic perspective view showing a lighting device 201C according to the present embodiment and a projection image 99 projected from lighting device 201C. As shown in FIG. 24C, the illumination device 201C can form the non-irradiation area 599 at an arbitrary position of the projection image 99 formed on the projection target 199. The non-illuminated area 599 can be freely arranged in the projection range. Therefore, when the lighting device 201C of the present embodiment is used as a headlight of a vehicle, the lighting device 201C can be applied to an adaptive driving beam.

  Subsequently, a method for manufacturing the wavelength conversion element 1 used in the present embodiment will be described with reference to FIG. 24D. FIG. 24D is a photograph showing a shape of wavelength conversion member 40 according to the present exemplary embodiment. More specifically, FIG. 24D shows that a reflecting member 3 is formed on a supporting surface 2a of a wafer-shaped supporting member 2 which is, for example, a silicon substrate, and a plurality of the reflecting members 3 are further formed thereon by screen printing as in the first embodiment. 2 is a photograph of a part of the structure in which the wavelength conversion member 40 is formed. FIG. 24D also shows a schematic top view in which the wavelength conversion member 40 is enlarged.

  As shown in FIG. 24D, the wavelength conversion member 40 according to the present embodiment has a horizontal (that is, longitudinal) length of 10 mm and a vertical direction (that is, width) in FIG. Direction) has a rectangular shape with a length of 3 mm, and is formed at a pitch of 15 mm in the horizontal direction and at a pitch of 4 mm in the vertical direction. Therefore, after the wavelength conversion member 40 is formed, the wavelength conversion element 1 is manufactured by cutting the wafer-shaped support member 2 at a predetermined pitch.

  Subsequently, the cross-sectional shape of the wavelength conversion element 1 manufactured by the above method will be described with reference to FIGS. 24E to 24G. 24E to 24G are graphs showing measurement results of the film thickness of the wavelength conversion element 1 according to the present embodiment. FIGS. 24E to 24G show the film thicknesses of the cross sections taken along line XXIVE-XXIVE, line XXIVF-XXIVF, and line XXIVG-XXIVG shown in FIG. 24D, respectively. In the XXIVF-XXIVF line and the XXIVG-XXIVG line, the film thickness of the central region is about 20 μm and the film thickness of the peripheral region is slightly thicker than that of the central region, as in the first embodiment. That is, the wavelength conversion member 40 has a concave shape. In the XXIVE-XXIVE line, the film thickness of the wavelength conversion member 40 is approximately constant at about 20 μm. Therefore, the wavelength conversion member 40 according to the present embodiment has an elongated shape in a top view of the support surface 2a, and the first top described in the first embodiment is in the longitudinal direction of the wavelength conversion member 40. At the end in the direction perpendicular to the

  In the wavelength conversion member 40 having such a configuration, the film thickness of the wavelength conversion member 40 can be constant in the major axis direction of the scanning region 84w shown in FIG. 24B. On the other hand, by forming a concave shape in the short axis direction of the scanning area 84w, the chromaticity change is small, and the wavelength conversion member 40 is separated from the support member 2 in response to a temperature change of the wavelength conversion element. Can be suppressed. FIG. 24H is a graph showing a simulation result of a color distribution in a light emitting region of the wavelength conversion element 1 based on the film thickness distribution of the wavelength conversion member 40 described above. The horizontal axis indicates the position, and the vertical axis indicates the chromaticity x. As shown in FIG. 24H, it can be seen that a light emitting device with a small color distribution can be realized in a wide light emitting region.

  In the light emitting device 101C and the lighting device 201C having the above-described configurations, the same effects as those of the light emitting device 101 and the lighting device 201 according to Embodiment 1 can be obtained. In the present embodiment, since the excitation light is scanned on the wavelength conversion element 1 using the movable mirror unit, the degree of freedom of the pattern of the projection image 99 can be increased.

(Embodiment 6)
Next, a light emitting device according to Embodiment 6 will be described with reference to FIGS. 25A to 25C. In the above-described embodiment, the configuration in which the excitation light is irradiated from one obliquely above the wavelength conversion element is described as the configuration of the light emitting device. However, in the light emitting device according to the present embodiment, by irradiating excitation light from a plurality of directions, light with a larger light amount can be emitted from the wavelength conversion element. FIG. 25A is a schematic sectional view showing the irradiation direction of the wavelength conversion element 1F and the excitation light 84 in the light emitting device according to the present embodiment. As shown in FIG. 25A, in the present embodiment, the excitation light 84 is emitted from two directions, one obliquely above and the other obliquely above the wavelength conversion element 1F according to the fourth embodiment. In the configuration example shown in FIG. 25A, the wavelength conversion element 1F is irradiated with the excitation light from two directions along two optical paths symmetric with respect to a plane passing through the excitation region of the excitation light 84 and orthogonal to the support surface 2a. .

Experimental results performed using this configuration example will be described with reference to FIGS. 25B and 25C. FIG. 25B is a graph illustrating a luminance distribution in a light emitting region of the wavelength conversion element 1F according to the present embodiment. FIG. 25C is a table showing an outline of experimental results of the light emitting device according to the present embodiment. FIGS. 25B and 25C show experimental results when the wavelength conversion element 1F is irradiated with the excitation light 84 having a light output of 3.5 W from two directions. That is, in this experiment, the wavelength conversion element 1F was irradiated with the excitation light 84 having a total optical output of 7 W. At this time, the diameter of the light emitting region was adjusted to be approximately 1 mm. Also in this case, as in the first embodiment, as shown in the luminance distribution of the light emitting region in FIG. 25B, the peak luminance exceeding 1000 cd / mm ² and the wavelength conversion member in the light emitting region of 150 ° C. or less of 125 ° C. A surface temperature of 40 was achieved. At this time, as shown in FIG. 25C, assuming that a region having a luminance of 1 / e ² or more of the peak luminance is a light emitting region size, the light emitting region in a direction parallel to the plane of FIG. 25A (a direction parallel to a plane including the excitation light) The width of the light emitting region was 0.9 mm, and the width of the light emitting region in the direction perpendicular to the plane of FIG. 25A (the direction perpendicular to the plane containing the excitation light) was 1.1 mm. A light flux of 1000 lm or more could be emitted from this light emitting region. This luminous flux is very high as a luminous flux from the minute light emitting region as described above.

  As described above, according to the light emitting device that irradiates the wavelength conversion element 1F with a plurality of excitation lights, it is possible to emit a large amount of radiation while maintaining the surface temperature of the wavelength conversion element 1F at a predetermined temperature or lower. it can. Further, in the present embodiment, with respect to the top portion around the wavelength conversion element 1F, the top portion formed in a plane parallel to the paper surface of FIG. 25A is the second top portion, and is formed in a direction passing through the excitation region and perpendicular to the paper surface. The top may be a first top, and the height of the second top from the support surface 2a may be lower than the height of the first top from the support surface 2a. In other words, the height from the support surface 2a of the second top arranged in the plane containing the excitation light 84 is changed to the support surface 2a of the first top arranged in a plane passing through the excitation region and perpendicular to the plane. May be lower than the height from With this configuration, it is possible to prevent a part of the excitation light 84 from being kicked at the second top.

  In the above configuration, two cases of a plurality of excitation lights have been described, but the present invention is not limited thereto. A similar application can be implemented when three or more excitation lights are used.

(Other modified examples)
As described above, the present disclosure has been described based on the embodiments, but the present disclosure is not limited to these embodiments. Without departing from the gist of the present disclosure, various modifications conceivable by those skilled in the art may be applied to the present embodiment, and another embodiment constructed by combining some components in the embodiment may be included in the scope of the present disclosure. Contained within.

  For example, in Embodiment 2 and the like, an example is described in which a transparent material is used as the scattering particles 43, but a material other than a transparent material may be used as the scattering particles 43. The material forming the scattering particles 43 may be any material that has low absorption for the excitation light and the fluorescence and scatters the excitation light, and may be, for example, a white resin.

  Further, the wavelength conversion member 40F according to the fourth embodiment has the shape characteristics of the wavelength conversion member 40 according to the first embodiment, but the configuration of the wavelength conversion member 40F according to the fourth embodiment is not limited thereto. . That is, the wavelength conversion member 40F according to the fourth embodiment does not have to have the same shape as the wavelength conversion member 40 according to the first embodiment. For example, the thickness of the wavelength conversion member 40F may be substantially constant over the entire region.

  As described above, the wavelength conversion element of the present disclosure suppresses a temperature rise of the wavelength conversion member with respect to the excitation light having a high light density, and can easily adjust the chromaticity coordinates of the emitted light. A light-emitting device using an element can easily emit outgoing light with high luminance. Therefore, the wavelength conversion element and the light emitting device using the same according to the present disclosure are useful in various lighting devices such as headlights of vehicles, ships, and trains, light sources for projectors, light sources for spotlights, and medical light sources.

1, 1B, 1C, 1D, 1F Wavelength conversion element 2 Support member 2a Support surface 2d Arranged area 3 Reflective member 3a Adhesive layer 3b First reflective film 3c Second reflective film 5a Micro-projection 5b Micro-recess 6 Radiation surface 6a Peripheral area 6b Central region 7 Joining surface 40, 40B, 40C, 40D, 40F Wavelength conversion member 41 First phosphor particles 42 Transparent binder 43 Scattering particles 44 Second phosphor particles 45 Void 50 Base 50a Storage 50b Side wall 51 Light shielding cover 52 Screw 53, 520b Holder 55 Adhesive member 81, 83, 95 Outgoing light 84 Exciting light 85 First outgoing light 91 Second outgoing light 96 Projection light 99 Projection image 101, 101B, 101C Light emitting device 110 Semiconductor light emitting device 111 Semiconductor light emitting element Reference Signs List 120 condensing optical member 120a lens 120b reflecting optical element 120c condensing lens 1 0 Photodetector 140 Translucent member 150 Exciting region 151 Emitting region 160 Printed circuit board 160b Second printed circuit board 170 Connector 190 Rotating mechanism 191 Rotating axis 199 Projecting object 201, 201B, 201C Illuminating device 220 Light emitting member 221 Fourth Base 314B, 314R Dichroic mirror 320 Light source unit 325 Heat sink 331B, 332B, 331R, 332R Reflection mirror 350B, 350G, 350R Image display device 360 Dichroic prism 365 Projection lens 379B Blue light 379Y Yellow light 379G Green light 379R Red light 80G 380R Signal light 389 Projection light 520 Movable mirror unit 520a Movable mirror 540 Third base 550 Second base 599 Non-irradiated area 1063 Light emitting device (Light source device)
1070 Excitation light source 1071 Phosphor wheel 1075 Light guide device 1130 Base material 1131 Phosphor layer 1138 Reflection layer 1139 Excitation light condensing lens P1 First top S1 First inclined portion

Claims (26)

A support member having a support surface,
A wavelength conversion member disposed above the support surface,
The wavelength conversion member has a radiation surface located on the opposite side of the support surface,
The radiation surface includes a peripheral region including a peripheral edge of the radiation surface, and a central region surrounded by the peripheral region,
At least a portion of the peripheral region has a first top projecting from the central region in a direction away from the support surface,
The wavelength conversion element, wherein the radiation surface has a first inclined portion inclined toward the support surface from the first top toward the central region. The wavelength conversion element according to claim 1, wherein the central region includes a flat portion whose inclination is gentler than the first inclined portion. The wavelength conversion element according to claim 1, wherein a plurality of minute projections are formed on the radiation surface of the first inclined portion. The wavelength conversion element according to any one of claims 1 to 3, wherein an arrangement region of the support surface where the wavelength conversion member is arranged is a flat surface. The wavelength conversion element according to any one of claims 1 to 4, wherein a thickness of the wavelength conversion member at the first top portion is larger than a thickness of the wavelength conversion member in the central region. The wavelength conversion element according to any one of claims 1 to 5, wherein a film thickness of the wavelength conversion member in the central region is 15 µm or more and 35 µm or less. The wavelength conversion element according to any one of claims 1 to 6, wherein the wavelength conversion member includes a plurality of first phosphor particles made of the same material in the central region and the first top. The wavelength conversion element according to claim 7, wherein the wavelength conversion member includes a transparent binding material that binds the plurality of first phosphor particles. The wavelength conversion element according to claim 8, wherein the wavelength conversion member includes a plurality of scattering particles bonded to the transparent bonding material. The wavelength conversion element according to any one of claims 7 to 9, wherein a total volume of the plurality of first phosphor particles is 35% or more and 62% or less with respect to a volume of the wavelength conversion member. In a cross section of the wavelength conversion member, a total of cross sections of the plurality of first phosphor particles is 40% or more and 80% or less with respect to a cross sectional area of the wavelength conversion member. A wavelength conversion element according to the item. A plurality of minute protrusions are formed on the radiation surface of the first inclined portion,
At least a part of the plurality of minute projections is formed by part of the plurality of first phosphor particles protruding from the radiation surface. Wavelength conversion element. The wavelength conversion member includes second phosphor particles different from the plurality of first phosphor particles,
Said plurality of first phosphor particles, Ce is activated _{(Y x Gd 1-x)} 3 (Al y Ga 1-y) 5 O 12 (0.5 ≦ x ≦ 1,0.5 ≦ y ≦ 1) or (La _1-x1 , Y _x1 ) ₃ Si ₆ N ₁₁ (0 ≦ x1 ≦ 1) in which Ce is activated;
The second phosphor particles, Ce is activated _{(La 1-x2, Y x2} ) 3 Si 6 N 11 (0 ≦ x2 ≦ 1, x1 ≠ x2) any one of claims 7 to 12 comprising 3. The wavelength conversion element according to 1. The peripheral area,
The first top portion is disposed at a position opposite to the central region, and has a second top portion projecting from the central region in a direction away from the support surface,
The wavelength conversion element according to any one of claims 1 to 13, wherein the radiation surface includes a second inclined portion inclined from the second top toward the support surface toward the central region. The wavelength conversion element according to claim 14, wherein the first top has a higher height from the support surface than the second top. In a top view of the support surface, the wavelength conversion member has an elongated shape,
The wavelength conversion element according to any one of claims 1 to 15, wherein the first top is disposed at an end of the wavelength conversion member in a direction perpendicular to a longitudinal direction. The wavelength conversion element according to any one of claims 1 to 16, further comprising a reflection member disposed between the wavelength conversion member and the support member. Wherein the support member silicon (Si), of silicon carbide (SiC), and sapphire _{(Al 2 O} 3), the wavelength conversion device according to any one of claims 1 to 17 comprising aluminum nitride (AlN) or diamond. A support member having a support surface,
A wavelength conversion member disposed above the support surface,
The wavelength conversion member,
A plurality of first phosphor particles that generate first fluorescence;
A plurality of second phosphor particles that generate second fluorescence having a spectrum different from the first fluorescence;
A transparent binder that binds the plurality of first phosphor particles and the plurality of second phosphor particles,
Combined with the transparent binder, and includes a plurality of first phosphor particles and scattering particles different from the plurality of second phosphor particles,
The plurality of first phosphor particles include (La _1-x1 , Y _x1 ) ₃ Si ₆ N ₁₁ (0 ≦ x1 ≦ 1) in which Ce is activated,
The wavelength conversion element, wherein the plurality of second phosphor particles include (La _1-x2 , Y _x2 ) ₃ Si ₆ N ₁₁ (0 ≦ x2 ≦ 1, x1 ≠ x2) in which Ce is activated. The wavelength conversion element according to claim 19, wherein the scattering particles include a metal oxide or nitride. 21. The wavelength conversion element according to claim 19, wherein a median diameter of the plurality of first phosphor particles and the plurality of second phosphor particles is 2 μm or more and 30 μm or less. The wavelength conversion element according to any one of claims 19 to 21, wherein the plurality of first phosphor particles and the plurality of second phosphor particles have a median diameter of 3 m or more and 9 m or less. A wavelength conversion element according to any one of claims 1 to 22,
A light emitting device comprising: an excitation light source that irradiates the wavelength conversion element with excitation light,
The luminance of light emitted from the light emitting device is 1000 cd / mm ² or more. A wavelength conversion element according to claim 15,
A light emitting device comprising: an excitation light source that irradiates the wavelength conversion element with excitation light,
The excitation light is obliquely incident on the radiation surface from the second top side,
The light emitting device, wherein the wavelength conversion member converts the wavelength of the excitation light. A light emitting device according to claim 23 or 24,
A lighting device comprising: a light projecting member that receives light emitted from the light emitting device and emits projection light. A straight line orthogonal to the optical axis of the excitation light at a position where the excitation light is incident on the wavelength conversion member, including a straight line parallel to the support surface, and projected onto a plane perpendicular to the support surface. The lighting device according to claim 25, wherein the light is emitted from the plane toward the excitation light source.

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