WO2018198949A1

WO2018198949A1 - Wavelength converting element, light-emitting device, and illumination device

Info

Publication number: WO2018198949A1
Application number: PCT/JP2018/016230
Authority: WO
Inventors: 高瀬　裕志; 山中　一彦
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2017-04-27
Filing date: 2018-04-20
Publication date: 2018-11-01
Also published as: JP7028863B2; JPWO2018198949A1

Abstract

A wavelength converting element (1) comprises: a support member (2) having a support surface (2a); and a wavelength converting member (40) that is disposed above the support surface (2a). The wavelength converting member (40) has a radiating surface (6) that is located on the opposite side from the support surface (2a). The radiating surface (6) includes a peripheral region (6a) that includes the periphery of the radiating surface (6) and a central region (6b) that is surrounded by the peripheral region (6a). At least part of the peripheral region (6a) has a first apex (P1) that protrudes from the central region (6b) in a direction away from the support surface (2a). The radiating surface (6) has a first inclined section (S1) that is inclined toward the support surface (2a) in the direction from the first apex (P1) toward the central region (6b).

Description

Wavelength conversion element, light emitting device, and illumination device

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

Conventionally, a light-emitting device using an excitation light source and a wavelength conversion element has been proposed (see, for example, Patent Document 1). As this type of light-emitting device, 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. Composed.

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

The excitation light emitted from the excitation light source 1070 is condensed by the excitation light condensing lens and irradiated to the phosphor layer 1131. 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, by using a heat transfer member such as a copper plate as the base material 1130, it has been proposed to dissipate heat effectively by distributing the heat generated in the phosphor layer to the entire heat transfer member.

JP 2010-85740 A

In the light emitting device 1063 that obtains the emitted light by irradiating the phosphor layer with the excitation light disclosed in Patent Document 1, in order to emit the emitted light with higher luminance, the light having a high light density is irradiated on the wavelength conversion element. In this case, the temperature rises locally in the region where the excitation light of the phosphor layer 1131 is irradiated. Such an increase in the temperature of the phosphor layer causes a rapid 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 that can sufficiently convert excitation light into fluorescence and that has increased mechanical strength, and a light-emitting device and an illumination apparatus that include the wavelength conversion element.

In order to solve the above problem, one aspect 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, and the wavelength conversion member includes: A radiation surface located on the opposite side of the support surface, the radiation surface including a peripheral region including a peripheral edge of the radial surface and a central region surrounded by the peripheral region, and at least a part of the peripheral region; Has a first apex protruding from the central region in a direction away from the support surface, and the radiation surface is inclined to the support surface side from the first apex toward the central region. It has an inclined part.

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, when the wavelength conversion member is thicker, the stress applied to the wavelength conversion member along with the temperature change of the wavelength conversion element is relieved, and the wavelength conversion member can be prevented from peeling off from the support member. .

On the other hand, the thinner the wavelength conversion member, the more the temperature increase 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 excitation light, the excitation light can be sufficiently converted to fluorescence by suppressing the temperature increase of the wavelength conversion member.

In addition, by providing a peripheral portion with a thick wavelength conversion member around the central region, the wavelength conversion member is supported against changes in the environmental temperature of the wavelength conversion element and temperature changes when the wavelength conversion element emits light. The 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.

Further, in one aspect of the wavelength conversion element according to the present disclosure, the central region may include a flat portion having a gentler inclination than the first inclined portion.

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

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

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

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

Moreover, 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 portion.

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

Further, in one aspect of the wavelength conversion element according to the present disclosure, the wavelength conversion member may include a plurality of scattering particles combined with the transparent binder.

Moreover, 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 the cross section of the wavelength conversion member, the total cross-sectional area of the plurality of first phosphor particles is 40% or more with respect to the cross-sectional area of the wavelength conversion member. It may be 80% or less.

Further, in one aspect of the wavelength conversion element according to the present disclosure, a plurality of minute convex portions are formed on the radiation surface of the first inclined portion, and at least a part of the plurality of minute convex portions is the A part of the plurality of first phosphor particles may be formed by projecting on the radiation surface.

In the 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 includes 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 (0 ≦ x1 ≦ 1), and the second phosphor particles are activated with Ce (La _1-x2 , Y _x2 ) ₃ Si ₆ N ₁₁ ( 0 ≦ x2 ≦ 1, x1 ≠ x2) may be included.

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 central region with respect to the first top portion, and from the central region in a direction away from the support surface. And the radiating surface may have a second inclined portion inclined toward the support surface from the second top portion toward the central region.

Further, in one aspect of the wavelength conversion element according to the present disclosure, the first top portion may be higher in height from the support surface than the second top portion.

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

Moreover, in one aspect of the wavelength conversion element according to the present disclosure, a reflection member disposed between the wavelength conversion member and the support member may be further provided.

In the 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.

Moreover, one mode 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, and the wavelength conversion member generates first fluorescence. A plurality of first phosphor particles, a plurality of second phosphor particles generating second fluorescence having a spectrum different from that of the first fluorescence, the plurality of first phosphor particles, and the plurality of second phosphor particles. A plurality of first fluorescent particles, and a plurality of first fluorescent particles which are bonded to the transparent binder and are different from 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) in which Ce is activated, and the plurality of second phosphor particles are activated in Ce (La _{_{_{_{1-x2, Y x2) 3}}}} Si 6 N 11 (0 ≦ x2 ≦ 1, x1 ≠ x ) Including the.

Thus, since the wavelength conversion member includes the first phosphor particles and the second phosphor particles that emit fluorescence having different spectra, it is possible to adjust the mixing ratio of each particle to more freely emit light. The chromaticity coordinates can be adjusted.

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

Moreover, in one aspect of the wavelength conversion element according to the present disclosure, the median diameters 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, the median diameters 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.

In addition, one aspect of the 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, and the luminance of light emitted from the light emission apparatus is 1000 cd / mm ² or more.

Moreover, one mode of the 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, and the excitation light is on the second top side. The wavelength conversion member wavelength-converts the excitation light.

Moreover, one aspect of the illumination device according to the present disclosure may include the light-emitting device and a light projecting member that emits projection light when incident light is emitted from the light-emitting device.

Further, in one aspect of the illumination device according to the present disclosure, the excitation light is 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, and includes a straight line parallel to the support surface, The projection light may be emitted from the plane toward the excitation light source with respect to a plane perpendicular to the support surface.

According to the present disclosure, it is possible to provide a wavelength conversion element that can sufficiently convert excitation light into fluorescence and that has increased mechanical strength, and a light-emitting device and an illumination apparatus that include the wavelength conversion element.

FIG. 1 is a schematic cross-sectional view showing the configuration of the wavelength conversion element of the first embodiment. FIG. 2 is a diagram illustrating the shape of the support surface of the wavelength conversion element according to Embodiment 1 in a top view. 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 showing the configuration of the lighting apparatus according to Embodiment 1. FIG. 5 is an enlarged view of the vicinity of 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 the measurement result of the luminance of the emitted light emitted from the wavelength conversion member according to the first embodiment. FIG. 8 is a graph showing measurement results of each surface shape 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 showing the configuration of the wavelength conversion element according to the first modification of the first embodiment. FIG. 10 is a schematic diagram illustrating the configuration of the light emitting device and the lighting device according to the second modification of the first embodiment. FIG. 11 is a top view showing the configuration of the wavelength conversion element according to the second modification of the first embodiment. FIG. 12 is a schematic cross-sectional view showing the configuration of the wavelength conversion element according to the second embodiment. FIG. 13 is a photograph of a cross section of the wavelength conversion element according to the second embodiment observed 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 in the chromaticity coordinates of the emitted light in the wavelength conversion element according to the second embodiment. FIG. 17 is a diagram illustrating a refractive index and a thermal conductivity of a material that can constitute the wavelength conversion member. 18 shows the temperature of the quantum efficiency of the La ₃ Si ₆ N ₁₁ : Ce phosphor used in the wavelength conversion member according to Embodiment 3 and the Y ₃ Al ₅ O ₁₂ : Ce phosphor used in Embodiment 1. FIG. It is a figure which shows dependency. FIG. 19 is a diagram showing the 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 drive current of the semiconductor light emitting device of the light emitting device according to Embodiment 3 is 2.3 amperes. FIG. 21 is a schematic cross-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 including the wavelength conversion element according to the fourth embodiment. FIG. 24A is a schematic cross-sectional view showing the configuration of the lighting apparatus according to Embodiment 5. FIG. 24B is an enlarged cross-sectional view of the wavelength conversion element according to Embodiment 5 and its surroundings. FIG. 24C is a schematic perspective view illustrating the illumination apparatus according to Embodiment 5 and a projection image projected from the illumination apparatus. 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 showing a second measurement result of the film thickness of the wavelength conversion element according to the fifth embodiment. 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 the light emitting region of the wavelength conversion element according to the fifth embodiment. FIG. 25A is a schematic cross-sectional view showing the irradiation direction of the wavelength conversion element and the excitation light in the light emitting device according to Embodiment 6. FIG. 25B is a graph showing a luminance distribution of the wavelength conversion element of the light-emitting device according to Embodiment 6. FIG. 25C is a table showing an outline 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, each embodiment will be described with reference to the drawings. Note that each of the embodiments described below shows a specific example of the present disclosure. Therefore, numerical values, shapes, materials, components, and arrangement positions and connection forms of the components shown in the following embodiments are merely examples, and are not intended to limit the present disclosure. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims of the present disclosure are described as arbitrary constituent elements. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between the parts, and the like are not necessarily the same as actual ones. Even in the case where substantially the same part is represented, the dimensions and ratio may be represented differently depending on the drawing. In some cases, duplicate descriptions for substantially the same configuration may be omitted.

Also, in this specification, the term “upward” does not indicate the upward direction (vertically upward) in absolute space recognition, but is a term defined by a relative positional relationship based on the stacking order in the stacking configuration. Used as In addition, the term “above” means not only when two components are spaced apart from each other and another component is present between the two components, but the two components are in close contact with each other. It is also applied to the case where two components are in contact with each other.

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

[Basic configuration]
FIG. 1 is a schematic cross-sectional view showing the configuration of the 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 disposed 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 binder 42 that binds the plurality of first phosphor particles 41. The wavelength conversion member 40 has a joint 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 is opposed to the bonding surface 7 and includes the radiation surface 6 on which the excitation light 84 is incident and the emission light 95 is emitted. Of the support surface 2a, a region facing the bonding surface 7 is an arrangement region 2d where the wavelength conversion member 40 is arranged. In the present embodiment, the arrangement region 2d is a plane.

The outgoing light 95 including the first outgoing light 85 and the second outgoing light 91 is emitted from the radiation surface 6 of the wavelength conversion member 40. The first outgoing light 85 is scattered excitation light 84. The second emitted light 91 is fluorescence obtained by converting the wavelength of the excitation light 84. Moreover, the radiation surface 6 of the wavelength conversion member 40 includes a plurality of minute convex portions 5a and a plurality of minute concave portions 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 apex P1 that protrudes 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 radiating surface 6 is formed with a large number of microscopic irregularities microscopically, but when viewed macroscopically, the radiating surface 6 is inclined to the support surface 2a side from the first top P1 toward the central region 6b. It has 1 inclined part 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 apex P1.

In the present embodiment, a plurality of minute convex portions 5a are formed on the radiation surface 6 in the first inclined portion S1. In addition, the micro convex part 5a here is a convex part detected when a radiation surface 6 is microscopically seen. The dimension of the minute projection 5a in the direction parallel to the support surface 2a is 50% or less of the film thickness of the wavelength conversion member 40. Further, the central region 6b includes a flat portion F1 whose inclination is gentler than that of the first inclined portion S1. 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. Further, the flat portion F1 referred to here may be formed with minute irregularities, as long as it is macroscopically flat. For example, the flat part F 1 may include unevenness whose dimension in the direction parallel to the support surface 2 a is about 50% or less of the film 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 portion P1 with respect to the central region 6b, and protrudes 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 film thickness of the wavelength conversion member 40 is thicker than the central region 6b in the vicinity of the first top portion P1 and the second top portion P2 of the peripheral region 6a. That is, a concave shape is formed from the first top portion P1 to the second top portion 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 the support surface 2a to the first top portion P1 is higher than the height from the support surface 2a to the second top portion P2. Here, as will be described later, the excitation light 84 is incident on the central region 6 b of the wavelength conversion member 40 obliquely. Therefore, as in the present embodiment, 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, the excitation light 84 is transmitted from the second top P2 side. By being incident in the direction toward the first apex P 1, the excitation light 84 can be reduced from being blocked by the peripheral region 6 a of the wavelength conversion member 40. Therefore, it is possible to increase the proportion of the component incident on the central region 6b in the excitation light 84. That is, the utilization efficiency of the excitation light 84 can be increased.

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 protruding from the central region 6b is formed in one peripheral region 6a (the peripheral region 6a on the right side in FIG. 1). It is formed. The radiating surface 6 has a third inclined portion S3 that sharply inclines toward the support surface 2a from the first top portion P1 toward the peripheral edge E1 of the radiating surface 6. In the other peripheral area 6a (the peripheral area 6a on the left side in FIG. 1), a second apex P2 is formed in the same manner. The radiating surface 6 has a fourth inclined portion S4 that sharply inclines toward the support surface 2a from the second top portion P2 toward the peripheral edge E2 of the radiating surface 6.

The reflection member 3 is a member that 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 2 a of the support member 2.

The function of the wavelength conversion element 1 having the above-described configuration will be described. In the wavelength conversion element 1 according to the present embodiment, 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 having a high light density in which light having strong light intensity is converged in a predetermined small region. In FIG. 1, most of the excitation light 84 incident on the wavelength conversion element 1 is incident on the excitation region 150 that 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. In addition, on the radiation surface 6 and inside of the wavelength conversion member 40, there are interfaces of media having different refractive indexes, that is, an interface between air and the wavelength conversion member 40 and an interface between the first phosphor particles 41 and the transparent binder 42. Exists. For this reason, the excitation light 84 incident on the wavelength conversion member 40 is irregularly reflected or multiple-reflected inside and on the radiation surface 6 of the wavelength conversion member 40, and a part of the excitation light 84 is the first outgoing light 85 (shown in FIG. 1). The light is emitted from the wavelength conversion member 40 as a solid line arrow). At this time, the first outgoing light 85 is irregularly reflected or multiply reflected by the radiation surface 6 of the wavelength converting member 40 and the interface existing inside. Therefore, the directivity of the excitation light 84 made of laser light is reduced in the first outgoing light 85. Therefore, the wavelength conversion element 1 can radiate the first outgoing light 85 as light whose outgoing 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 is emitted as wavelength-converted fluorescence. This fluorescent light is irregularly reflected or multiple-reflected directly or on the interface between the first phosphor particles 41 and the transparent binder 42, and then the second emitted light 91 (see FIG. 1) from the radiation surface 6 of the wavelength conversion member 40. Radiated as a dashed arrow).

Therefore, from the radiation surface 6 of the wavelength conversion element 1, the outgoing light 95 which is a mixed light in which the first outgoing light 85 and the second outgoing light 91 are mixed is emitted. At this time, the region where the emitted light 95 is emitted is from the light emitting region 151 that is larger than the excitation region 150 because both the first emitted light 85 and the second emitted light 91 are multiple-reflected within the wavelength conversion member 40. 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 closely attaching 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 bonds 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 ) Yttrium-aluminum-garnet (YAG) -based phosphors such as ₅ O ₁₂ (0.5 ≦ x ≦ 1, 0.5 ≦ y ≦ 1) can be used. And the median diameter D50 of the 1st fluorescent substance particle 41 contained in a wavelength conversion member is 2 micrometers or more and 30 micrometers or less, for example. Moreover, when using such 1st fluorescent substance particle 41, the film thickness of the wavelength conversion member 40 is 2 micrometers or more and 50 micrometers or less in the excitation area | region 150, for example.

As other materials constituting the first phosphor particles 41, europium (Eu) activated α-SiAlON, Eu activated (Ba, Sr) Si ₂ O ₂ N _2, etc., depending on 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 emitted light 91, the heat generated in the first phosphor particles 41 is quickly exhausted to the support member 2; It is composed of a material having a high rate, for example, a material having 5 W / mK or more.

The transparent binder 42 may be formed of a transparent material having a large refractive index difference 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 for forming the transparent binder 42 is, for example, a transparent material mainly composed of silicon (Si) and oxygen (O), and examples thereof include glass, silsesquioxane, and silicone.

In the wavelength conversion member 40, when the plurality of first phosphor particles 41 convert the excitation light 84 into the second emission light 91, the heat generated in the first phosphor particles 41 is quickly supplied to the support member 2. You may have the structure which can exhaust heat. Specifically, the plurality of first phosphor particles 41 having a higher thermal conductivity than the transparent binder 42 are arranged close to each other. A 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 area of the interface is preferably as large as possible. Therefore, the structure may be such that the adjacent first phosphor particles 41 are close to each other but separated by the wavelength of the excitation light 84 or more, and the transparent binder 42 is filled therebetween. At this time, there is no problem even if the adjacent first phosphor particles 41 are in contact with each other.

The material forming the support member 2 is a material having a high thermal conductivity and a small difference in thermal expansion coefficient from that of the transparent binder 42 in order to more efficiently absorb the heat generated in the wavelength conversion element 1. 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. The support member 2 may be a semiconductor crystal substrate or a ceramic substrate made of these materials.

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

And the support surface 2a of the support member 2 on which the reflecting member 3 is formed may be a flat and mirror-finished surface. Thereby, the reflecting member 3 formed on the support surface 2a can be formed of a flat film. Therefore, the 1st emitted light 85 and the 2nd emitted light 91 which reached | attained the reflection member 3 can be reflected efficiently.

[Detailed configuration and manufacturing method]
Next, a specific shape and size of the wavelength conversion element 1 will be described with a manufacturing method. In addition, about the manufacturing method of the wavelength conversion element 1, including the method which is not essential, it demonstrates concretely.

First, a wafer-like member as a base of the support member 2 is prepared. In the present 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, the one on which the support surface 2a side is processed into a mirror surface and a flat surface by mechanochemical polishing is used.

Subsequently, the reflective member 3 is formed by sequentially forming the adhesion layer 3a, the first reflective film 3b, and the second reflective film 3c on the support surface 2a, which is one main surface of the support member 2, by an evaporation method or the like. To do. More specifically, the reflecting member 3 includes, in order from the support member 2 side, an adhesion layer 3a 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 reflective film 3c has both functions of a surface protective layer for protecting the first reflective film 3b and a reflective layer for suppressing light absorption in the first reflective film 3b made of metal. . In addition, the adhesion layer 3 a suppresses the reflection member 3 from being peeled from the support member 2 in a dicing process when a wafer described later is divided into individual wavelength conversion elements 1.

Subsequently, a screen mesh printing mask in which a plurality of predetermined openings are formed is disposed above the support surface 2 a of the support member 2. At this time, the openings are two-dimensionally formed at a pitch of 2 mm to 10 mm in the plane. In the present embodiment, a 3.5 mm pitch product and a 5 mm pitch product were produced. For example, at a pitch of 5 mm, about 100 openings are formed within a diameter of 3 inches. The screen mesh printing mask is formed by weaving metal fibers such as stainless steel or synthetic fibers such as polyester, for example. By printing through the mesh of the mesh, the volume of the paste that passes is smaller than that of an opening mask made of metal or the like, so that a thin film can be formed by printing. Moreover, the shape of the wavelength conversion member 40 can be freely formed by using a shape that matches the shape of the desired wavelength conversion member 40 as the shape of the opening. Further, the thickness of the screen mesh printing mask can be set according to the 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 the raw material constituting the transparent binder 42 dissolved in an organic solvent is produced. At this time, using Ce-activated Y ₃ Al ₅ O ₁₂ phosphors with median diameters D50 of _3, 4, 6, and 9 μm, respectively, the median diameter of the first phosphor particles 41 was changed as a parameter, and the phosphor paste was changed. Make it. In the wavelength conversion member 40 according to the present embodiment, a transparent material whose main component is polymethylsilsesquioxane is used as the transparent binder 42. Therefore, as the phosphor paste, a material obtained by dispersing a plurality of the first phosphor particles 41 in a transparent binder in which silsesquioxane is dissolved in an organic solvent is used. At this time, an organic solvent having a low boiling point with respect to the temperature in the high temperature curing step described later is selected. Then, 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-described phosphor paste has a desired viscosity.

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

Subsequently, unnecessary phosphor paste overflowing from the opening with a squeegee is removed, and the screen mesh printing mask is pressed against the support surface 2a of the wafer to release it, so that the phosphor paste filled in the opening is supported on the support surface 2a. Transcript to.

Subsequently, the printing mask is removed, and the wafer on which a plurality of phosphor pastes are formed in a predetermined pattern is heated in a high temperature furnace or the like, for example, at a temperature of about 200 ° C. for about 2 hours. By this high temperature curing process, the raw materials of the transparent binder in the phosphor paste are condensed, and a wafer-like 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 in this way will be described with reference to FIG.

FIG. 2 is a diagram showing the shape of the support surface 2a of the wavelength conversion element 1 according to the present embodiment in a top view. FIG. 2 includes a photograph (a) in a top view of a part of the wavelength conversion element 1 manufactured using the above manufacturing process, and an enlarged plan view of one wavelength conversion element 1 shown in the photograph (a). b). 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 with a broken line in a photograph (a) and a top view (b) shows the outline of the supporting member 2 after being separated into pieces so that it may mention later.

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

Next, the wafer on which a plurality of wavelength conversion members 40 having a film thickness of 2 μm or more and 50 μm or less produced by the above process are fixed is divided by dicing. Specifically, it is divided at a pitch of 3.7 mm using a dicing blade having a blade width of 0.2 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 3.5 mm square wavelength conversion element 1 as shown in the plan view (b) of FIG. 2 is manufactured. The

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 characteristics of the wavelength conversion element 1 manufactured in this way will be described in more detail with reference to FIGS. FIG. 3 is a photograph of a cross section of the wavelength conversion element 1 according to the present embodiment observed with 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 the broken-line frame part of the cross-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 in a top view of the support surface 2 a. That is, in the wavelength conversion element 1, the arrangement region 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 way, when the wavelength conversion element 1 is used as, for example, a component of a light emitting device, a region where the wavelength conversion member 40 around the wavelength conversion element 1 is not formed is formed by a collet or the like. By chucking and carrying, it can be easily fixed at a place where the wavelength conversion element 1 is disposed, such as a base of a light emitting device.

As shown in FIG. 3, the wavelength conversion element 1 includes a support member 2 that is a silicon substrate, a reflection member 3 composed of a silver film, a dielectric multilayer film, and the like disposed on the support member 2, and a reflection member. 3 is provided with a wavelength conversion member 40 disposed on the surface 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 film 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. By arranging in this way, the heat generated in the first phosphor particles 41 can be efficiently conducted to the support member 2 through the adjacent first phosphor particles 41. That is, the heat generated in the first phosphor particles 41 can be mainly conducted to the support member 2 through the first phosphor particles 41 having a higher thermal conductivity than the transparent binder 42. A plurality of minute convex portions 5 a 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 a part of the plurality of first phosphor particles 41 protruding on the radiation surface 6. That is, the minute convex part 5a along the surface of the first phosphor particle 41 is formed. A minute recess 5b is formed beside the minute protrusion 5a. Thus, by forming minute irregularities on the surface of the wavelength conversion member 40, the excitation light 84 can be efficiently scattered. Furthermore, 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 this gentle unevenness, that is, the interval between adjacent convex portions or the interval between adjacent concave portions is larger than 50% of the average film thickness of the concave and convex portions of the wavelength conversion member 40 and about 5 times or less. In this way, the excitation light 84 can be scattered more efficiently by forming the rough irregularities on the surface of the wavelength conversion member in comparison with the minute irregularities.

[Light emitting device and lighting device]
Next, a light-emitting device and an illumination 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 showing the configuration of the illumination device 201 according to the present embodiment.

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

The light projecting member 220 is an optical member that emits the projection light 96 when the emitted light 95 from the light emitting device 101 is incident thereon. In the present embodiment, the 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 condensing 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. A 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 emitted light 81 emitted from the semiconductor light emitting element 111 is emitted upward in FIG.

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

The light emitting device 101 further includes a printed circuit board 160 on which a photodetector 130 is mounted. The printed circuit board 160 is disposed on the bottom surface 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 multimode laser having an optical waveguide width of 10 μm or more. The reflective optical element 120b is, for example, a reflective mirror on which a plurality of concave mirror surfaces are formed. With this configuration, the outgoing light 81 emitted upward in FIG. 4 from the semiconductor light emitting element 111 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. That is, the excitation light 84 irradiated to the wavelength conversion element 1 is partly converted by the wavelength conversion member 40 of the wavelength conversion element 1, and the first emission light 85 made of scattered light and the second emission made of fluorescence. It becomes the emitted light 95 comprised with the incident light 91, and is radiate | emitted from the light-emitting device 101. FIG.

The emitted light 95 emitted from the light emitting device 101 is emitted from the illumination device 201 as projection light 96 that is substantially parallel light by the light projecting member 220.

The light emitting device 101 includes a connector 170. The connector 170 is a connector that can be connected to an external circuit. As a result, electric power can be applied to the semiconductor light emitting device 110 and the printed circuit board 160 from the outside. The light emitting device 101 further includes a photodetector 130 such as a photodiode. The photodetector 130 is mounted on the printed circuit board 160. Thereby, the light from the wavelength conversion element 1 is received, and a detection signal indicating the light emission state of the light emitting device 101 can be output to the outside. Moreover, the translucent member 140 which is a cover glass, for example is arrange | positioned on the wavelength conversion element 1 upper part. The translucent member 140 is attached to a holder 53 formed of a metal such as aluminum, like 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 condensing optical member 120 and the wavelength conversion element 1 which comprise 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 electrical wiring, and obliquely above the wavelength conversion element 1 disposed below. The excitation light 84 can be incident from the above. Therefore, the light emitting device 101 can be thinned.

Further, the excitation light 84 is obliquely incident on the radiation surface 6 from the second apex 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 in the direction from the second apex P2 side toward the first apex 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, it is possible to increase the proportion of the component incident on the central region 6b in the excitation light 84. That is, the utilization efficiency of the excitation light 84 can be increased.

In the above configuration, the beam shape of the excitation light 84 is shaped using the reflective optical element 120b. With this configuration, the light intensity distribution of the excitation light 84 irradiated 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 almost opposite to the direction in which the excitation light 84 enters the wavelength conversion member 40. In other words, it is a straight line perpendicular to the optical axis of the excitation light 84 at a position where the excitation light 84 is incident on the wavelength conversion member 40, and includes a straight line parallel to the support surface and 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. For this reason, light with a high brightness | luminance can be radiate | emitted from the wavelength conversion element 1 rather than the case where a light emitting diode etc. are used. Then, the light emitted from the light emitting device 101 can be irradiated far away using the light projecting member 220.

[Fixing 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 of the vicinity of 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 in a top view of the support surface 2a. And the wavelength conversion member 40 is formed on the reflection member 3 of the support surface 2a.

The base 50 of the light emitting device 101 is formed with a storage portion 50a having a rectangular shape when viewed from the top and having a concave shape that is slightly larger than the outer shape of the support member 2. And the wavelength conversion element 1 is fixed to the bottom face of the storage part 50a.

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

Furthermore, in the light emitting device 101 according to the present embodiment, the light shielding cover 51 is disposed on the upper part of the storage unit 50a in the base 50 in which the wavelength conversion element 1 is stored. The light shielding cover 51 is formed with an opening for allowing the excitation light 84 and the outgoing light 95 to pass therethrough, and is formed of a black metal plate. 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 6 a 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 screws 52, for example. As a result, the excitation light 84 is applied to the region of the support surface 2a of the wavelength conversion element 1 where the wavelength conversion member 40 is not formed, and the generation of stray light is suppressed.

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, stray light can be suppressed from being included in the projection light 96 of the illumination device.

Furthermore, the wavelength conversion member 40 of the wavelength conversion element 1 has a concave shape in which the central region 6b is thin and the peripheral region 6a is thicker than the central region 6b. For this reason, when manufacturing the light-emitting device 101, it can suppress that the light shielding cover 51 contacts the light emission area | region located in the center area | region 6b of the wavelength conversion member 40. FIG. That is, even when the light shielding cover 51 approaches the wavelength conversion member 40, the light emission in the flat portion F 1 of the central region 6 b of the wavelength conversion member 40 is brought into contact with the peripheral region 6 a before the central region 6 b 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 emitted light 95 of the wavelength conversion element 1 falls.

In the present embodiment, part or all of the space between the side surface of the support member 2 and the storage portion 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 configuration as described above, the wavelength conversion element 1 according to the present embodiment and the light emitting device 101 using the wavelength conversion element 1 can emit outgoing light with high luminance. Such a light emitting device 101 can realize a lighting device 201 with high luminous intensity when the lighting device 201 is configured using a small light projecting member 220. Therefore, the light emitting device 101 according to the present embodiment is suitable as a light source used for a vehicle headlamp or the like.

[Operation and effect]
Next, the operation and effect of the wavelength conversion element 1 according to this 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. About the brightness | luminance of the emitted light 95 from the light-emitting device 101, and the surface temperature of the wavelength conversion element 1, it measured using the thermography from the upper direction of FIG. 4 in the state which removed the light projection member 220 from the illuminating device 201 shown in FIG. did. The method for measuring the surface temperature is not limited to thermography, and may be other methods.

The light emitting device 101 includes a semiconductor light emitting device 110 for irradiating the wavelength conversion element 1 with excitation light 84. The reflection optical element 120b for shaping the beam of the excitation light 84 irradiated to the wavelength conversion element 1 is also 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 dissipate generated heat to the outside.

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

On the other hand, of the light incident on the wavelength conversion member 40, the light that is not absorbed by the first phosphor particles 41 is reflected on the surface or inside of the wavelength conversion member 40 and is emitted from the wavelength conversion member 40 to the first outgoing light 85. Is emitted 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 is 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 radiated as first outgoing light 85 radiated in all directions from the radiation surface 6 of the wavelength conversion member 40. On the other hand, the light that is reflected near the radiation surface 6 of the wavelength conversion member 40 or near the radiation surface 6 and is emitted as the first outgoing light 85 is also a minute convex portion, a minute concave portion of the radiation surface 6 of the wavelength conversion member 40, Alternatively, the light is diffused and radiated at the interface between the first phosphor particles 41 and the transparent binder 42 existing in the vicinity of the radiation surface 6. For this reason, the light reflected at or near the radiation surface 6 and emitted as the first outgoing light 85 is also emitted from the radiation surface 6 of the wavelength conversion member 40 in all directions.

As a result, from the radiation surface 6 of the wavelength conversion member 40, the emitted light 95, which is a mixed light in which the first emitted light 85 and the second emitted light 91 emitted in all directions are mixed, is emitted. 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 thinner than the maximum film thickness of the peripheral region 6a. And the center area | region 6b which is a concave bottom face has the flat part F1 with a small change of thickness. Further, the flat portion F 1 near the bottom surface of the concave shape may be set to be larger than the excitation region 150 of the excitation light 84 and the light emission region 151 of the emitted light 95. Thereby, the chromaticity distribution of the outgoing light 95 emitted from the wavelength conversion member 40 can be made uniform.

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

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

First, the graph (a) in FIG. 6 is a diagram showing the temperature dependence of the quantum efficiency of 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) of FIG. 6 irradiates the wavelength conversion member 40 with the excitation light 84, the excitation light scattered and reflected by the wavelength conversion member 40, and the excitation light 84 is absorbed and converted by the wavelength conversion member 40 and emitted. It is a figure for demonstrating the chromaticity coordinate of the emitted light 95 (white light) which is the mixed color light formed by mixing the fluorescence which is. In the present embodiment, an excitation light source that emits outgoing light that is blue laser light with chromaticity coordinates of (0.161, 0.014) and fluorescence with chromaticity coordinates of (0.426, 0.547). Experiments were performed using phosphor particles (YAG). Therefore, in the graph (b) of FIG. 3, a straight line (mixed light trajectory) connecting the chromaticity coordinates (0.161, 0.014) and (0.426, 0.547) and the black body radiation trajectory. The chromaticity coordinates (0.317, 0.327) that intersect with each other were used as chromaticity coordinate targets.

Graphs (c) and (e) in FIG. 6 show the excitation converted into a square shape with a light output of about 3.2 watts and an irradiation range of about 0.7 mm on the wavelength conversion element 1 according to the present embodiment. 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) in 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 set to 45:65. In the graph (e) of FIG. 6, the measurement was performed by changing the volume ratio of the first phosphor particles 41 and the transparent binder 42 while setting the median diameter D50 of the first phosphor particles 41 to 6 μm. 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 represented by Vb / (Vf + Vb).

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

As described above, the phosphor conversion efficiency decreases as the temperature of the phosphor particles increases. In particular, when the temperature is 150 ° C. or higher, the conversion efficiency rapidly decreases. In such a case, the amount of heat generated in the wavelength conversion member 40 increases abruptly, causing quenching in phosphor conversion, and the light emitting device hardly emits light. For example, when the external environment changes and the temperature of the phosphor particles increases significantly, the light emitting device may not emit light. In the 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 wavelength conversion member 40 may have a thickness of 35 μm or less so that the wavelength conversion element 1 can stably emit high-luminance white light.

On the other hand, for the graphs (d) and (f) in FIG. 6, as in the graphs (c) and (e) in FIG. 6, the luminous intensity of the emitted light 95 when the configuration of the wavelength conversion member 40 is changed. It is the figure which showed chromaticity change.

As described above, the target of chromaticity coordinates of white light is (0.317, 0.327). Therefore, the target range is 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. Regarding the x value, the x value of the chromaticity coordinates decreases as the thickness of the wavelength conversion member 40 decreases, and the x value increases as it increases in thickness. That is, as the thickness of the wavelength conversion member 40 becomes thinner, the white light becomes more bluish and as the thickness becomes thicker, 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 radiated without being sufficiently converted into fluorescence by the wavelength conversion member 40, so that the ratio of the first outgoing light 85 in the outgoing light 95 is increased. This is because the ratio of the second emitted light 91 is higher. On the other hand, when the thickness of the wavelength conversion member 40 is increased, most of the excitation light 84 is converted into fluorescence by the wavelength conversion member 40, so that the ratio of the second emission light 91 in the emission light 95 is the first. This is because the ratio of the outgoing light 85 becomes higher.

The first outgoing light 85 emitted from the wavelength conversion member 40 is light that is emitted after the excitation light 84 is irregularly reflected or multiple-reflected at the interface between the first phosphor particles 41 and the transparent binder 42. In addition, a part of the first outgoing light 85 includes the excitation light 84 that reaches the reflection member 3 and is reflected in the process of irregular reflection or multiple reflection. 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 coordinate of the emitted light 95 with respect to the film thickness of the wavelength conversion member 40 increases. The rate will be moderate. This is presumably because the ratio of the excitation light 84 in which the first outgoing light 85 does not reach the reflecting member 3 in the process of irregular reflection or multiple reflection 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 coordinate of the outgoing light 95 is rapidly lowered as the thickness is reduced. 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 outgoing light 95, the thickness of the wavelength conversion member 40 may be 15 μm or more.

As described above, the range where the x value of the chromaticity coordinates is 0.30 or more and 0.35 or less is the target range. In order to realize this target range, as shown in graphs (d) and (f) of FIG. 6, the thickness of the wavelength conversion member 40 may be 15 μm or more.

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. May be. Further, as shown in graphs (c) to (f) of FIG. 6, when the median diameter D50 of the first phosphor particles 41 is 3 μm or more and 9 μm or less, the film thickness of the wavelength conversion member 40 is 15 μm or more and 35 μm or less. Can be set by range. Further, the total volume (that is, volume ratio) of the first phosphor particles 41 can be set to 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% to 80% with respect to the cross-sectional area of the wavelength conversion member 40.

The effect of the said embodiment is demonstrated using FIG. FIG. 7 is a graph showing the measurement result of the luminance of the outgoing light 95 emitted from the 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 for emitting the excitation light 84 and the luminance peak value in the emission region of the emitted light 95. Moreover, the graph (a) of FIG. 7 used the wavelength conversion member 40 with a film thickness of 42 micrometers together with the result of the light-emitting device using the wavelength conversion member 40 with a film thickness of 20 micrometers according to the present embodiment. The result of the light-emitting device of the comparative example is shown. In this measurement, the wavelength conversion element 1 is irradiated with excitation light 84 having a peak wavelength of 446 nm at an environmental 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 driving current of about 2 amperes. That is, at a driving current of 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 drive current, the temperature of the first phosphor particles 41 of the wavelength conversion member 40 is increased along with the surface temperature of the wavelength conversion member 40. This is considered to be because the conversion efficiency of the first phosphor particles 41 is drastically decreased. On the other hand, in the wavelength conversion element 1 of the present embodiment, the luminance peak of the emitted light 95 increases as the driving current increases even when the driving current is 2 amperes or more, and a light emitting device exceeding the peak luminance of 1000 cd / mm ² can be realized. . A graph (b) in 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 amperes. 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, the luminance is 1000 cd / mm ² or more, and a flat region is obtained with a width of 0.2 mm or more. That is, a light emitting device having a flat luminance distribution and a high luminance light emitting region 151 can be realized.

Subsequently, an example of the shape 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 each surface shape when the wavelength conversion member 40 of the wavelength conversion element 1 according to Embodiment 1 is manufactured by three different methods. The graph (a1) in FIG. 8 shows that the opening of the screen mesh printing mask is a circular opening having 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 printed. The graph (b1) in FIG. 8 shows that the opening of the screen mesh printing 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 with a width of 3.4 mm, the thickness is 62 μm, and the volume ratio between the first phosphor particles 41 and the transparent binder 42 is 40%. : 60% printed. 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.

Note that the mesh used here may be, for example, a mesh formed of a material not containing Fe. When printing is performed with a mesh formed of a material containing Fe, fine powder of Fe is mixed in the wavelength conversion member, and a part of the first emitted light or the second emitted light is absorbed and the efficiency is lowered. By using a mesh formed of a material that does not contain Fe, the above-described decrease in efficiency can be suppressed.

In the results shown in the graphs (a1) and (a2) of FIG. 8, the film thickness of the central region of the wavelength conversion member 40 is 44 μm, and the wavelength conversion member 40 has a convex shape whose central region is thicker than the peripheral region. In this case, as described above, the change in the film thickness of the wavelength conversion member 40 in the vicinity of the light emitting region is small, but since the film thickness is thick, the temperature of the wavelength conversion member 40 is increased, and it is difficult to increase the luminance of the light emitting device.

In 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 the temperature increase of the wavelength conversion member 40 can be suppressed. However, since the film thickness may change in the range of 20 μm to 24 μm in the light emitting region, chromaticity unevenness in the light emitting region of the emitted light may occur.

On the other hand, in the results shown in the graphs (c1) and (c2) of FIG. 8, the film thickness of the central region of the wavelength conversion member 40 is 18 μm, and the film thickness of the peripheral region is 24 μm. Thus, the wavelength conversion member 40 has a concave shape. For this reason, while making the film thickness of the center area | region of the wavelength conversion member 40 into 35 micrometers or less, the change of the film thickness of a center area | 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 to 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 with the temperature change of the wavelength conversion element 1 is alleviated, 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, the wavelength conversion member 40 is thick in the vicinity of the central region that emits fluorescence and the wavelength conversion member 40 is thin. A peripheral part is provided. For this reason, peeling of the wavelength conversion member 40 from the support member 2 can be suppressed with respect to changes in the environmental temperature of the wavelength conversion element 1 and temperature changes when the wavelength conversion element 1 is caused to emit light. That is, in the wavelength conversion element 1 according to the present embodiment, the mechanical strength can be increased. Further, by increasing the film thickness of the peripheral region 6a, it is possible to increase the heat radiation efficiency from the central region 6b that is relatively high temperature to the peripheral region 6a.

Therefore, as the shape of the wavelength conversion member 40, a concave shape having a thin film thickness in the central region as shown in the graphs (c1) and (c2) of FIG. 8 is optimal. Further, in the wavelength conversion element 1 shown in the graphs (c1) and (c2) of FIG. 8, the film thickness of the wavelength conversion member 40 including the peripheral region is 35 μm or less. Therefore, the temperature rise of the wavelength conversion member 40 can be suppressed regardless of where the excitation light 84 is irradiated on the wavelength conversion member 40. For this reason, 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 is not affected even if the excitation light 84 is irradiated to a place other than the central region of the wavelength conversion member 40. Deterioration caused by a temperature increase of 40 can be suppressed.

In addition, the wavelength conversion member 40 as shown in the graphs (c1) and (c2) of FIG. 8 appropriately changes the volume ratio of the first phosphor particles 41 and the transparent binder 42 according to the dimensions of the wavelength conversion member. It can be realized by adjusting. In addition, the scanning direction of the squeegee in the fluorescent paste printing process 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) in FIG. 8, the squeegee is scanned from the left side to the right side in the drawing in the fluorescent paste printing process for forming the wavelength conversion member 40. For this reason, it is considered that the film thickness at the right end of the wavelength conversion member 40 is the largest because the amount of the phosphor paste increases at the end of the print mask opening on the scanning end point side of the fluorescent paste printing process.

(Modification 1 of Embodiment 1)
Subsequently, a wavelength conversion element according to Modification 1 of Embodiment 1 will be described with reference to the drawings. FIG. 9 is a schematic cross-sectional view showing the configuration of the wavelength conversion element 1B according to this 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 this 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. Specifically, in FIG. 9, the maximum film thickness d _e2 of the right peripheral area 6a shown in FIG. 9 is larger than the film thickness d _{c of the} center area (d _e2 > d _c ), and the maximum film thickness of the left peripheral area 6a is the film thickness is about the same as the thickness d _c of the central region 6b.

With this configuration, when the wavelength conversion element 1B is fixed to the storage unit 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. Contact with the part F1) can be suppressed.

The wavelength conversion element 1B having such a configuration can be manufactured by adjusting the shape of the screen mesh printing mask and the scanning condition of the squeegee as shown in the 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 Modification 2 of Embodiment 1 will be described with reference to the drawings. The wavelength conversion element, the light-emitting device, and the illumination device according to this modification are different from the wavelength conversion element 1, the light-emitting device 101, and the illumination device 201 shown in FIG. FIG. 10 is a schematic diagram illustrating the configuration of the light emitting device 101B and the illumination device 201B according to the present modification. FIG. 11 is a top view showing the configuration of the wavelength conversion element 1C of the present modification.

The illumination device 201B mainly includes a light emitting device 101B that emits an emitted 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. A lens 365. The illumination device 201B further includes reflection mirrors 331R, 332R, 331B, and 332B, and a dichroic prism 360.

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

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 combines 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 modification, 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 central wavelength of the emission wavelength in the vicinity of 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 the TO-CAN package.

The emitted 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 is directed to the wavelength conversion element 1C. As described above, the condensing optical member 120 includes the lens 120a and the condensing lens 120c.

The wavelength conversion element 1 C is a phosphor wheel in this modification, and has a disk-shaped support member 2 made of an aluminum alloy plate, for example, as shown in FIG. 11. A wavelength conversion member 40 C is formed in a ring shape in the outer peripheral region of the support surface 2 a 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. Note that the wavelength conversion element 1C shown in FIG. 10 shows a cross section of the wavelength conversion element 1C taken along the line XX of FIG.

At this time, the wavelength conversion member 40C of the wavelength conversion element 1C has a thickness of 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. And the maximum film thickness of the peripheral area | region of the wavelength conversion member 40C is thick compared with the film thickness of a center area | 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 shown 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.

In this modification as well, 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 to 35 μm, 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 as the rotation mechanism 190 rotates. Then, the excitation light 84 is condensed on the excitation region 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 has the first emission light 85 which 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 emitted light 95, which is white light mixed with the second emitted light 91, which is fluorescence converted in wavelength by the first phosphor particles 41.

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

The emitted light 95 becomes projection light 96 that is parallel light by the light projecting member 220 that is a condenser lens, and is converted into projection light 389 that is image light by the following operation inside the illumination device 201B. First, the projection light 96 is separated by the dichroic mirror 314B into blue light 379B having a main wavelength band of 430 nm or more and 500 nm or less and 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 green light 379G having a main wavelength band of 500 nm to 580 nm and 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. Green light 379G passes through a polarizing element (not shown) to become polarized light and enters the image display element 350G. The blue light 379B, the green light 379G, and the red light 379R incident on the

image display elements

350B, 350G, and 350R are respectively signal light on which video information is superimposed by each image display element and a polarization element (not shown) on the emission side. 380B, 380G and 380R. The signal lights 380B, 380G, and 380R are applied to the dichroic prism 360 and combined to become the combined light 385. By passing the combined light 385 through a projection lens, it is possible to obtain projection light 389 that is image light.

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 having an area of 1 mm ² or less in the excitation region 150. 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 film thickness of the wavelength conversion member 40C in the light emitting region 151 is in the range of 15 μm to 35 μm. As described above, according to such a wavelength conversion member 40C, the excitation light 84 can be converted into the outgoing light 95 while suppressing a temperature rise, and therefore, for example, conversion can be performed with a conversion efficiency of 200 lm / W. Therefore, a light emitting device that emits emitted light 95 having a luminance peak of 1000 cd / mm ² or more can be easily realized.

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

(Embodiment 2)
Next, the wavelength conversion element according to Embodiment 2 will be described. The wavelength conversion element according to the present embodiment is different from the wavelength conversion element 1 according to Embodiment 1 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 with a focus on differences from the wavelength conversion element 1 according to the first embodiment.

FIG. 12 is a schematic cross-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 a plurality of scattering particles that are combined with the transparent binder 42 in addition to the first phosphor particles 41 and 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 point glass can be used. As silsesquioxane, for example, polymethylsilsesquioxane can be used. Further, as the scattering particles 43, non-light-emitting particles composed of a material with little mediation with respect to excitation light and fluorescence with a median diameter D50 of 0.3 μm to 18 μm are mixed.

As the scattering particles 43, for example, a transparent material having a high thermal conductivity and a large refractive index difference from the transparent binder 42 is used. The scattering particles may include a metal oxide or nitride. 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 It is in the range of 35 μm or less.

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

In the wavelength conversion element 1D configured as described above, the chromaticity coordinates of the outgoing light 95 can be freely designed according to the spectrum of the excitation light 84. Specifically, the chromaticity is changed for each light emitting device using the wavelength conversion element 1D by changing the ratio of 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. Coordinates can be adjusted. That is, even if the variation of the spectrum of the excitation light 84 occurs in each semiconductor light emitting device due to the variation in the structure 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 according to the present embodiment, a Y ₃ Al ₅ O ₁₂ : Ce phosphor having a median diameter D50 of 6 μm is used as the first phosphor particles 41. Polymethylsilsesquioxane is used as the transparent binder 42 that fixes the first phosphor particles 41. As the scattering particles 43 which are non-light emitting particles, Al ₂ O ₃ particles having a median diameter D50 of 3 μm are mixed. Al ₂ O _{3 has} a refractive index of 1.77 and a large refractive index difference from silsesquioxane having a refractive index of 1.5. Moreover, 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 formed by mixing the first phosphor particles 41 made of Y ₃ Al ₅ O ₁₂ : Ce and the transparent binder 42 made of polysilsesquioxane to form a phosphor paste. Compared with the 1st fluorescent substance particle 41 and the scattering particle | grains 43, it can comprise easily by reducing the ratio of the transparent binder 42 and hardening at high temperature.

Specifically, the ratio Vb / (Vf + Vs) of the volume Vb of the transparent binder 42 that 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 40% or less. A phosphor paste composed of a transparent binder 42 dissolved in an organic solvent, the first phosphor particles 41 and the scattering particles 43 is formed on the support member 2 and then subjected to high temperature annealing at about 200 ° C. As a result, 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 of a cross section of the wavelength conversion element 1D according to the present embodiment observed with a scanning electron microscope. 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 the broken-line frame part of the cross-sectional photograph (a).

As shown in FIG. 13, the reflection member 3 is formed on the support member 2 which is a silicon substrate, and the wavelength conversion member 40D is fixed thereon. The film 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. Furthermore, voids 45 are scattered in the inside of the wavelength conversion member 40 D and 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 in the transparent binder 42 and the voids 45 are scattered can be easily obtained. 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 reflective film 3c of the reflective member 3 which is a dielectric, the excitation light is effectively reduced while reducing energy loss due to excitation light and fluorescence incident on the metal surface. , Can scatter fluorescence.

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

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

FIG. 14 is a graph showing a spectrum of the emitted light 95 when the wavelength conversion element 1D according to the present embodiment is irradiated with the excitation light 84 having a peak wavelength of 447 nm. The first output light 85 has a sharp peak at a wavelength of 447 nm, and the second output 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 emitted light 91, a spectrum 10 times the intensity of the second emitted light 91 is indicated by a broken line.

FIG. 15 is a graph showing changes 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 is set to 35%. . 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 is 76%, 73%, 69%, 65%, 61%, and 51%, respectively. Was made. Then, each wavelength conversion element 1D was irradiated with laser light having a peak wavelength of 447 nm as excitation light 84, and the chromaticity coordinates of the emitted light 95 were plotted in FIG. In addition, the continuous line shown in FIG. 15 shows the locus | trajectory of black body 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. Further, by increasing 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 used as targets of the chromaticity coordinates, the volume ratio of the first phosphor particles 41 and the scattering particles 43 is set to 61%. Output light can be obtained. Therefore, the chromaticity coordinate of the emitted light can be easily set to the predetermined chromaticity coordinate by changing the volume ratio of the first phosphor particles 41 and the scattering particles 43.

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

FIG. 16 is a graph showing the result of measuring the peak wavelength dependence of the excitation light of 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) between the first phosphor particles 41 and the scattering particles 43 is 76%, 73%, 69%, 65%, 61%, which is the same as that shown in FIG. The change of the chromaticity coordinate y was plotted using those having the peak wavelengths 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 increased. By changing the chromaticity coordinates of the emitted light, the predetermined chromaticity coordinates can be set.

Furthermore, in this embodiment, the effect of scattering light can be enhanced by increasing the refractive index difference between the transparent binder, 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 emitted 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, the luminance is 1000 cd / mm ² or more and a uniform region can be realized over a width of 0.2 mm or more.

(Embodiment 3)
Next, the wavelength conversion element and the light emitting device according to Embodiment 3 will be described. The wavelength conversion element and the light emitting device according to the present embodiment are different from the first and second embodiments 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 with a focus on differences from the first and second embodiments.

In the present embodiment, (La _x Y _1-x ) ₃ Si ₆ N ₁₁ : Ce (0.5 ≦ x ≦ 1) is used as the material constituting the first phosphor particles 41 included in the wavelength conversion member 40. The phosphor material represented by is used. FIG. 17 is a diagram showing the refractive index and the thermal conductivity of the material that can constitute 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 that absorbs blue light with a wavelength of about 430 nm to 470 nm and emits yellow fluorescence with 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 : Ce (0.5 ≦ x ≦ 1) and (Ba _x Sr _1-x ) SiO ₄ : Eu (0 ≦ x ≦ 1) ) And a phosphor represented by (Ba _x Sr _1-x ) Si ₂ O ₂ N ₂ : Eu (0 ≦ x ≦ 1) were compared. FIG. 17 shows (Y _x Gd _1-x ) ₃ (Al _y Ga _1-y ) ₅ O ₁₂ : Ce (0.5 ≦ x ≦ 1, 0.5 ≦ y ≦ 1) among these phosphors. Y ₃ Al ₅ O ₁₂ which is a central base material of the phosphor material represented by the formula (2) 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 a central base material, is shown. As materials used for the scattering particles 43, Al ₂ O ₃ , TiO ₂ , ZnO and BN are shown. Silsesquioxane, dimethyl silicone and low melting point glass are shown as materials used as the transparent binder 42. The material constituting the wavelength conversion member may be a material having high thermal conductivity. Further, in order to suppress the excitation light incident on the wavelength conversion member 40 from propagating in the lateral direction in the wavelength conversion member 40, the refractive index difference between the phosphor particles and the transparent binder, the scattering particles and the transparent binder. The refractive index difference between and may be large. As the phosphor material in terms _Y 3 _Al 5 _O 12: Ce phosphor or _La 3 _Si 6 _N 11: may be any of the Ce phosphor. The scattering particles may be any of Al ₂ O ₃ , ZnO, and BN.

Hereinafter, the characteristics of the wavelength conversion member according to the present embodiment will be described with reference to FIGS. 18 and 19. FIG. 18 shows the temperature of the quantum efficiency of 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 the phosphor with an excitation wavelength of 450 nm and converting it to fluorescence. FIG. 18 shows relative values as the quantum efficiency when the quantum efficiency when the environmental temperature (Ta) is 25 ° C. is 100%. Compared with Y ₃ Al ₅ O ₁₂ : Ce phosphor, La ₃ Si ₆ N ₁₁ : Ce has a lower rate of decrease in quantum efficiency at higher temperatures. 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 the light-emitting device having a high light density of excitation light.

FIG. 19 is a diagram showing 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 a volume ratio in the step of forming the wavelength conversion member, and the ratio of the first phosphor particles: scattering particles: transparent binder is 18%: 22. %: It was set to be 60%. Moreover, the same structure as Embodiment 1 shown in FIG.4 and FIG.5 was used as a structure of the wavelength conversion element 1 and the light-emitting device 101 which were used when measuring the characteristic. The film thickness of the wavelength conversion member 40 of the wavelength conversion element 1 was about 25 μm in the vicinity of the light emitting region 151.

FIG. 19 is a graph plotting the luminance peak value of the light emitting region 151 of the wavelength conversion member with respect to 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, the light emitting device of the comparative example using the YAG: Ce phosphor as the first phosphor particles shown in FIG. 7 and the wavelength conversion member having a film thickness of 42 μm operates at an environmental temperature (Ta) of 85 ° C. The characteristics are also shown. Similarly, the YAG: Ce phosphor is used as the first phosphor particle, and the characteristics when the light emitting device according to the first embodiment using the wavelength conversion member 40 with a film thickness of 20 μm is operated at an environmental 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 luminance increase rate with respect to an increase in driving current even at a driving current of ^{2 A} or more, and the 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 decreased and was saturated at less than 900 cd / mm ² . This is because the temperature of the wavelength conversion member 40 rises due to the heat that the wavelength conversion member 40 receives from the environment and the heat that is generated when the excitation light 84 is converted into the second emitted light 91, so that the quantum efficiency is drastically increased. It is thought that it falls. On the other hand, in the wavelength conversion element according to the present embodiment, as the first phosphor particles, the decrease in quantum efficiency with respect to the temperature rise is small (La _x Y _1-x ) ₃ Si ₆ N ₁₁ : Ce (0 ≦ x ≦ 1) A phosphor is used. Therefore, it reached 800 cd / mm ² or more at an environmental temperature of 85 ° C. and a driving current of 2 amperes, and further, there was no luminance saturation even at a driving current of more than that, reaching 900 cd / mm ² or more at a driving current of 2.3 amperes. FIG. 20 is a graph showing the 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 amperes 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 a dotted line. As shown in FIG. 20, the luminance distribution at the environmental temperature of 85 ° C. is lower by about 20% than the luminance distribution at the environmental temperature of 25 ° C. This is mainly due to the temperature dependence 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, a light-emitting device capable of high-intensity operation at high luminance with a luminance peak value of 900 cd / mm ² or higher can be realized even at an environmental temperature of 85 ° C. Such a light emitting device is most suitable for a lighting device that requires high temperature operation, for example, a vehicle headlamp.

(Embodiment 4)
Next, the wavelength conversion element according to Embodiment 4 will be described. In a conventional light emitting device such as the light emitting device described in Patent Document 1, the chromaticity coordinates of the emitted light are regulated by the type of phosphor contained in the phosphor layer, so 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 Embodiment 3 in that the wavelength conversion member includes the second phosphor particles in addition to the first phosphor particles, and other points. Match in 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 showing the configuration of the wavelength conversion element 1F according to the present embodiment. As shown in FIG. 21, the 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 arranged above the support surface 2a, and the wavelength conversion member 40F. 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 is further coupled to the transparent binder 42 that couples the plurality of first phosphor particles 41 and the plurality of second phosphor particles 44, the transparent binder 42, and the plurality of first fluorescence particles. It includes scattering particles 43 that are different from the body particles 41 and 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 a median diameter D50 of 2 μm or more and 30 μm or less (that is, the same And phosphor materials having different composition ratios. As with 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. A specific basic composition formula representing the first phosphor particles 41 and the second phosphor particles 44 is, for example, (La _x Y _1-x ) ₃ Si ₆ N ₁₁ : Ce (0.5 ≦ x ≦ 1) is there. That is, the plurality of first phosphor particles 41 includes Ce-activated (La _1-x1 , Y _x1 ) ₃ Si ₆ N ₁₁ (0 ≦ x1 ≦ 1), and the plurality of second phosphor particles 44 includes , And Ce activated (La _1-x2 , Y _x2 ) ₃ Si ₆ N ₁₁ (0 ≦ x2 ≦ 1, x1 ≠ x2).

Furthermore, the wavelength conversion member 40F includes scattering particles 43 that are non-light emitting particles that do not absorb excitation light. The scattering efficiency of the scattering particles 43 is higher when the median diameter D50 of the scattering particles 43 is closer to the median diameter of each phosphor particle. For this reason, 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. To 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 the median diameter is 9 μm (La) 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) between the volume Vf of the first phosphor particles 41 and the volume Vf2 of the second phosphor particles 44 is larger than 0% and smaller than 100%. Further, 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 the emitted light of the 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 according to the present embodiment, the same basic composition formula (La _x Y _1-x ) ₃ Si ₆ N ₁₁ : Ce (0.5 A phosphor satisfying ≦ x ≦ 1) is used. For this reason, the 2nd emitted light 91 which is the fluorescence which has the substantially same spectrum shape as each single spectrum shape of the 1st fluorescent substance particle 41 and the 2nd fluorescent substance particle 44 is radiate | emitted from the wavelength conversion element 1F. In addition, the relationship between the drive current (I _f ) and the luminance of the semiconductor light emitting device was also almost the same as the relationship in the light emitting device according to Embodiment 3 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 in which the wavelength conversion element 1F according to Embodiment 4 is mounted. In the chromaticity diagram on the left side of FIG. 23, the chromaticity coordinates of the first outgoing light 85 that is the scattered light of the excitation light having the peak wavelength of 445 nm are denoted by reference numeral 85. Further, the chromaticity coordinates of fluorescence emitted from the first phosphor particles 41 composed of La ₃ Si ₆ N ₁₁ : Ce are indicated by reference numeral 91a. _{_{_{Then, (La 0.84 Y 0.16) 3}}} Si 6 N 11: indicated by Ce second phosphor code 91b chromaticity coordinates of the fluorescence emitted from the particle 44 composed of. Therefore, the emitted light 95 in the case where 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 addition, the emitted light 95 in the case where the wavelength conversion member is constituted by the second phosphor particles 44, the scattering particles 43, and the transparent binder 42 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) in the left chromaticity diagram.

Here, as a configuration of the wavelength conversion member of the wavelength conversion element, the wavelength conversion elements (a) to (a) to (a) to (a) having the following three types of volume ratios of the first phosphor particles, the second phosphor particles, the scattering particles, and the transparent binder. c) was created 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 film thickness in the light emitting region 151 of the wavelength conversion member was about 25 μm. The chromaticity coordinates of the emitted light 95 were measured by mounting a wavelength conversion element on the light emitting device 101 shown in FIG.

23. The chromaticity coordinates 95a, 95b and 95c in the enlarged view on the right side of FIG. 23 are the chromaticity coordinates of the emitted light emitted from the wavelength conversion elements corresponding to the above (a), (b) and (c), respectively. Thus, by using the same basic color phosphors having different composition ratios and changing the mixing ratio, the chromaticity coordinates can be adjusted in directions other than the locus connecting the excitation light and the fluorescence. In other words, 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 of the first phosphor particles, the second phosphor particles, and the scattering particles. it can. That is, even when a large number of light emitting devices are produced, only three types of particles, the first phosphor particles, the second phosphor particles, and the scattering particles, should be prepared in order to obtain desired chromaticity coordinates.

More specifically, a region A shown in FIG. 23 is a chromaticity region of a vehicle headlamp defined by Japanese Industrial Standards JIS D 5500. When manufacturing a light-emitting device for this application, first phosphor particles, second phosphor particles, and scattering particles are prepared, and their ratios are adjusted to produce a wavelength conversion member and a wavelength conversion element. Thereby, it is possible to freely obtain the chromaticity of the shaded area portion within the chromaticity area defined by the above-mentioned standard.

Further, the scattering particles 43 included in the wavelength conversion member 40 also have an effect of improving the chromaticity uniformity of the emitted light in the light emitting region. In other words, the presence of the scattering particles 43 makes it possible to mix the first fluorescence emitted from the first phosphor particles 41 and the second fluorescence emitted from the second phosphor particles 44 by scattering. Therefore, the emitted light with uniform chromaticity can be emitted from the light emitting region of the wavelength conversion member 40.

With the configuration as described above, 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.

In the wavelength conversion member 40F according to the present embodiment, the median diameter D50 of the first phosphor particles 41 and the second phosphor particles 44 is (La _x Y _1-x ) ₃ Si ₆ N ₁₁ having a median diameter D50 of 2 μm to 30 μm. : Explained using Ce (0.5 ≦ x ≦ 1), but 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) or the like can be used. In this case, a material other than silsesquioxane may be used as the transparent binder. For example, by forming the transparent binder 42 with a material mainly composed of inorganic materials such as SiO ₂ , Al ₂ O ₃ , ZnO, Ta ₂ O ₅ , Nb ₂ O ₅ , TiO ₂ , AlN, BN, BaO, and the like. 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 with 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 do.

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

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

As shown in FIG. 24A, the illumination device 201C includes a light emitting device 101C, a light projecting member 220, and a fourth base 221. The light emitting device 101 C is a light source that emits outgoing light 95 from the wavelength conversion element 1. The illuminating device 201 C converts the emitted light 95 into the projection light 96 that is highly directional light by the light projecting member 220 and emits it.

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, the light emitting device 101C includes a movable mirror unit 520 in the optical path between the lens 120a and the 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 unit (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 portion is a support member that extends in the Dy1 direction in FIG. 24A, such as a torsion bar, and can tilt the movable mirror 520a in a direction that rotates around the Dy1 direction as a central axis. The inclination angle of the movable mirror 520a with respect to the holder 520b can be changed by using an 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. Further, 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 are connected to the printed circuit board 160.

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

The excitation light 84 irradiated to the wavelength conversion element 1 is partly wavelength-converted to fluorescence by the wavelength conversion member 40 of the wavelength conversion element 1, and the second emission light 91 composed of fluorescence and the second light composed of the 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. Electric power can be applied from the outside 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 light 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 illumination device 201C is a lens in the present embodiment. The light projecting member 220 is held on 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 area of the excitation light 84 to the wavelength conversion element 1 will be described with reference to FIG. 24B. FIG. 24B is an enlarged cross-sectional view of the wavelength conversion element 1 according to the present embodiment and its surroundings. 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 the irradiation region 84a of the excitation light 84 at a certain time. In the present embodiment, the irradiation region 84a can be moved, that is, scanned in the Sx1 direction or the Sx2 direction by changing the tilt direction of the movable mirror 520a. By periodically scanning the irradiation region 84a in a time sufficiently shorter than the afterimage time of human eyes, the wavelength conversion element 1 can emit light as an apparent light emitting region, which is the scanning region 84w that is the 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, the scanning region 84w In time, it is possible to set a region where the excitation light 84 is irradiated and a region where the excitation light 84 is not irradiated. That is, the non-irradiation region can be created by turning off the power applied to the semiconductor light emitting device 110 in an arbitrary tilt direction of the movable mirror 520a.

FIG. 24C is a schematic perspective view showing the illumination device 201C according to the present embodiment and a projection image 99 projected from the illumination device 201C. As illustrated in FIG. 24C, the illumination device 201C can form a non-irradiation region 599 at an arbitrary position of the projection image 99 formed on the projection target 199. The non-irradiation region 599 can be freely arranged in the projection range. For this reason, when the lighting device 201C of the present embodiment is used for a vehicle headlamp, it can be applied to an adaptive driving beam (Adaptive Driving Beam).

Then, the manufacturing method of the wavelength conversion element 1 used for this Embodiment is demonstrated using FIG. 24D. FIG. 24D is a photograph showing the shape of the wavelength conversion member 40 according to the present embodiment. More specifically, in FIG. 24D, for example, the reflecting member 3 is formed on the support surface 2a of the wafer-like support member 2 which is a silicon substrate, and a plurality of the reflection members 3 are further formed thereon by using screen printing in the same manner as in the first embodiment. It is a photograph of a part of what formed the wavelength conversion member 40 of. 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 length in the horizontal direction (that is, the longitudinal direction) 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 a pitch of 4 mm in the vertical direction. Therefore, after forming the wavelength conversion member 40, the wavelength conversion element 1 is manufactured by cutting the wafer-like support member 2 at a predetermined pitch.

Next, 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 the measurement results of the film thickness of the wavelength conversion element 1 according to the present embodiment. 24E to 24G show the film thicknesses of the cross sections along the XXIVE-XXIVE line, XXIVF-XXIVF line, and XXIVG-XXIVG line 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 as in the first embodiment, and the film thickness of the peripheral region is slightly thicker than that of the central region. That is, the wavelength conversion member 40 has a concave shape. In the XXIVE-XXIVE line, the film thickness of the wavelength converting member 40 is as constant as about 20 μm. Therefore, the wavelength conversion member 40 according to the present embodiment has a long shape in the top view of the support surface 2a, and the first top portion described in the first embodiment is the longitudinal direction of the wavelength conversion member 40. It is arrange | positioned at the edge part of a direction perpendicular | vertical to.

In the wavelength conversion member 40 having such a configuration, the film thickness of the wavelength conversion member 40 can be made constant with respect to the major axis direction of the scanning region 84w shown in FIG. 24B. On the other hand, with respect to the minor axis direction of the scanning region 84w, by making it concave, the chromaticity change is small, and the wavelength conversion member 40 is peeled from the support member 2 with respect to the temperature change of the wavelength conversion element. Can be suppressed. FIG. 24H is a graph showing a simulation result of the color distribution in the 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 having a small color distribution in a wide light emitting region can be realized.

Also in the light emitting device 101C and the lighting device 201C having the above-described configuration, the same effects as those of the light emitting device 101 and the lighting device 201 according to Embodiment 1 can be obtained. Moreover, in this Embodiment, since excitation light is scanned on the wavelength conversion element 1 using a movable mirror unit, the freedom degree of the pattern of the projection image 99 can be raised.

(Embodiment 6)
Next, a light-emitting device according to Embodiment 6 will be described with reference to FIGS. 25A to 25C. In the above embodiment, as the configuration of the light emitting device, the configuration in which the excitation light is irradiated from one diagonally upper side of the wavelength conversion element is shown. However, in the light emitting device according to the present embodiment, light having a larger amount of light can be emitted from the wavelength conversion element by irradiating excitation light from a plurality of directions. FIG. 25A is a schematic cross-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 irradiated from two directions, one diagonally upper side and the other diagonally upper side of 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 excitation light from two directions along two optical paths that are symmetrical with respect to a plane that passes through the excitation region of the excitation light 84 and is orthogonal to the support surface 2a. .

Results of experiments performed using this configuration example will be described with reference to FIGS. 25B and 25C. FIG. 25B is a graph showing a luminance distribution in the 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 this embodiment. 25B and 25C show experimental results when the wavelength conversion element 1F is irradiated with excitation light 84 having an optical output of 3.5 W from two directions. That is, in this experiment, the wavelength conversion element 1F was irradiated with excitation light 84 having a total light output of 7 W. At this time, the diameter of the light emitting region was adjusted to be about 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 wavelength conversion member in the light emitting region having a peak luminance exceeding 1000 cd / mm ² and 125 ° C. of 150 ° C. or lower A surface temperature of 40 could be realized. At this time, as shown in FIG. 25C, when a region having a luminance of 1 / e ² or more of the peak luminance is set as the light emitting region size, the direction in the direction parallel to the paper surface of FIG. 25A (the direction parallel to the 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 paper surface of FIG. 25A (the direction perpendicular to the plane containing the excitation light) was 1.1 mm. From this light emitting region, a light flux of 1000 lm or more could be emitted. 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 radiate a large amount of emitted light while maintaining the surface temperature of the wavelength conversion element 1F below a predetermined temperature. it can. Further, in the present embodiment, with respect to the top of the periphery of the wavelength conversion element 1F, the top formed in a plane parallel to the paper surface of FIG. 25A is formed in the direction perpendicular to the paper surface through the excitation region. The top may be the 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 portion disposed in the plane including the excitation light 84 is set to the height of the first top support surface 2a disposed in the plane that passes through the excitation region and is perpendicular to the plane. You may make it lower than the height from. With this configuration, it is possible to suppress a part of the excitation light 84 from being kicked at the second top portion.

In the above configuration, two cases are described as a plurality of excitation lights, but this is not restrictive. The same application can be performed even when three or more excitation lights are used.

(Other variations)
As mentioned above, although this indication was explained based on each embodiment, this indication is not limited to these embodiments. As long as the gist of the present disclosure is not deviated, various modifications conceived by those skilled in the art have been made in the present embodiment, and other forms constructed by combining some components in the embodiment are also within the scope of the present disclosure. Contained within.

For example, in the second embodiment and the like, an example in which a transparent material is used as the scattering particle 43 is shown, but a material other than the transparent material may be used as the scattering particle 43. The material that forms the scattering particles 43 may be any material that has little absorption with respect to excitation light and fluorescence and that scatters excitation light, and may be, for example, a white resin.

Further, the wavelength conversion member 40F according to the fourth embodiment includes 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 to this. . That is, the wavelength conversion member 40F according to the fourth embodiment may not have the shape as the wavelength conversion member 40 according to the first embodiment. For example, the film 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 the temperature increase of the wavelength conversion member with respect to 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 high-luminance outgoing light. Therefore, the wavelength conversion element of the present disclosure and the light emitting device using the same are useful in various illumination devices such as vehicles, ships, train headlights, projector light sources, spotlight light sources, and medical light sources.

1, 1B, 1C, 1D, 1F Wavelength conversion element 2 Support member 2a Support surface 2d Arrangement region 3 Reflective member 3a Adhesion layer 3b First reflection film 3c Second reflection film 5a Minute convex portion 5b Minute concave portion 6 Radiation surface 6a Peripheral region 6b Central region 7 Bonding surface 40, 40B, 40C, 40D, 40F Wavelength conversion member 41 First phosphor particle 42 Transparent binder 43 Scattering particle 44 Second phosphor particle 45 Void 50 Base 50a Storage unit 50b Side wall 51 Shading cover 52 Screw 53, 520b Holder 55 Adhesive member 81, 83, 95 Emitted light 84 Excited light 85 First emitted light 91 Second emitted light 96 Projected light 99 Projected image 101, 101B, 101C Light emitting device 110 Semiconductor light emitting device 111 Semiconductor light emitting element 120 condensing optical member 120a lens 120b reflective optical element 120c condensing lens 1 DESCRIPTION OF SYMBOLS 0 Photodetector 140 Translucent member 150 Excitation area | region 151 Light emission area | region 160 Printed circuit board 160b 2nd printed circuit board 170 Connector 190 Rotating mechanism 191 Rotating shaft 199 Projection object 201, 201B, 201C Illuminating device 220 Light projecting member 221 4th Base 314B, 314R Dichroic mirror 320 Light source unit 325 Heat sink 331B, 332B, 331R, 332R Reflective mirror 350B, 350G, 350R Image display element 360 Dichroic prism 365 Projection lens 379B Blue light 379Y Yellow light 379G Green light 379R Red light 380 380R Signal light 389 Projection light 520 Movable mirror unit 520a Movable mirror 540 Third base 550 Second base 599 Non-irradiation 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 Reflective layer 1139 Excitation light condensing lens P1 First apex S1 First inclined portion

Claims

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 that protrudes from the central region in a direction away from the support surface;
The wavelength conversion element, wherein the radiation surface includes a first inclined portion that is 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 that of the first inclined portion.
The wavelength conversion element according to claim 1, wherein a plurality of minute convex portions 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 film thickness at the first top of the wavelength conversion member is thicker than a film thickness at 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 not less than 15 袖 m and not more than 35 袖 m.
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 portion.
The wavelength conversion element according to claim 7, wherein the wavelength conversion member includes a transparent binder 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 binder.
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.
The cross-sectional area of the wavelength conversion member is such that the total cross-sectional area of the plurality of first phosphor particles is 40% or more and 80% or less in the cross-section of the wavelength conversion member. The wavelength conversion element according to item.
A plurality of minute convex portions are formed on the radiation surface in the first inclined portion,
The at least part of the plurality of minute convex portions is formed by projecting a part of the plurality of first phosphor particles on 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 include Ce-activated (La 1-x2 , Y x2 ) 3 Si 6 N 11 (0 ≦ x2 ≦ 1, x1 ≠ x2). The wavelength conversion element as described in 2.
The peripheral region is
The first top portion is disposed at a position opposite to the central region, and has a second top portion protruding 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 toward the support surface from the second top portion toward the central region.
The wavelength conversion element according to claim 14, wherein the first top portion is higher in height from the support surface than the second top portion.
In the top view of the support surface, the wavelength conversion member has a long shape,
The wavelength conversion element according to any one of claims 1 to 15, wherein the first top portion is disposed at an end portion in a direction perpendicular to a longitudinal direction of the wavelength conversion member.
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.
The wavelength conversion element according to any one of claims 1 to 17, wherein the support member includes silicon (Si), silicon carbide (SiC), sapphire (Al 2 O 3 ), 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 is
A plurality of first phosphor particles generating first fluorescence;
A plurality of second phosphor particles that generate second fluorescence having a spectrum different from that of the first fluorescence;
A transparent binder for binding the plurality of first phosphor particles and the plurality of second phosphor particles;
A scattering particle that binds to the transparent binder and is different from the plurality of first phosphor particles and the plurality of second phosphor particles;
The plurality of first phosphor particles include Ce-activated (La 1-x1 , Y x1 ) 3 Si 6 N 11 (0 ≦ x1 ≦ 1),
The wavelength conversion element, wherein the plurality of second phosphor particles include Ce-activated (La 1-x2 , Y x2 ) 3 Si 6 N 11 (0 ≦ x2 ≦ 1, x1 ≠ x2).
The wavelength conversion element according to claim 19, wherein the scattering particles include a metal oxide or nitride.
The wavelength conversion element according to claim 19 or 20, 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 a median diameter of the plurality of first phosphor particles and the plurality of second phosphor particles is 3 μm or more and 9 μm or less.
The wavelength conversion element according to any one of claims 1 to 22,
A light-emitting device comprising an excitation light source for irradiating the wavelength conversion element with excitation light,
The luminance of the emitted light from the light emitting device is 1000 cd / mm 2 or more.
The wavelength conversion element according to claim 15,
A light-emitting device comprising an excitation light source for irradiating the wavelength conversion element with excitation light,
The excitation light is incident obliquely with respect to the radiation surface from the second top side,
The wavelength conversion member is a light emitting device that converts the wavelength of the excitation light.
A light emitting device according to claim 23 or 24;
An illumination device comprising: a light projecting member that receives light emitted from the light emitting device and emits projection light.
The projection is a straight line that is perpendicular to the 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 and perpendicular to the support surface. The illuminating device according to claim 25, wherein the light is emitted from the plane toward the excitation light source.