Wavelength conversion device, light source device, and projector

Abstract

The invention provides a wavelength conversion device, a light source device and a projector, which can improve the bonding strength of a base material and a wavelength conversion element. This wavelength conversion device is provided with: a base material comprising copper and / or a copper alloy; a copper oxide layer formed on the first surface of the substrate; a bonding reinforcement layer which is a tin oxide layer that contains tin oxide and is laminated on the copper oxide layer; a bonding layer disposed on the bonding reinforcement layer; and a wavelength conversion element disposed on the bonding layer.

Description

Technical Field

[0001] The invention relates to a wavelength conversion device, a light source device and a projector. Background Art

[0002] In the past, the following projector is known, which includes: an illumination device that emits illumination light; a color separation optical system that separates red light, green light, and blue light from the illumination light; three light modulation devices that modulate the separated color lights; a synthesis optical system that synthesizes the modulated color lights; and a projection optical device that projects the synthesized image light (for example, refer to patent document 1).

[0003] The illumination device for a projector described in Patent Document 1 includes a first light source unit that emits excitation light having a first wavelength band, and a wavelength conversion element that converts the incident excitation light into fluorescence having a second wavelength band different from the first wavelength band.

[0004] The wavelength conversion element comprises a wavelength conversion layer, a first substrate, a first intermediate layer, a second substrate, and a second intermediate layer. The first substrate, the first intermediate layer, the wavelength conversion layer, the second intermediate layer and the second substrate are stacked in this order from the side where the excitation light is incident.

[0005] The first substrate is formed of a ceramic heat dissipation substrate.

[0006] The first intermediate layer is provided between the wavelength conversion layer and the first substrate. The first intermediate layer is composed of a first bonding layer provided on the first surface of the wavelength conversion layer and a second bonding layer provided on the first substrate. The first bonding layer and the second bonding layer are respectively composed of a siloxane compound with high light transmittance.

[0007] The wavelength conversion layer emits fluorescence when the excitation light is incident thereon. The wavelength conversion layer includes a phosphor layer, a total reflection layer, a reflection enhancement layer, a first degradation prevention layer, a reflection layer, and a second degradation prevention layer.

[0008] The second intermediate layer is composed of a silver layer and a nanosilver layer, and bonds the second substrate to the wavelength conversion layer.

[0009] The second substrate is formed of, for example, a metal heat dissipation substrate formed of copper.

[0010] Patent Document 1: Japanese Patent Application Publication No. 2021-144163

[0011] However, in the wavelength conversion device described in Patent Document 1, the second substrate made of copper is bonded to the wavelength conversion layer via the second intermediate layer made of a silver layer and a nanosilver layer. In this structure, it is difficult to increase the bonding strength between the copper substrate and the wavelength conversion layer.

[0012] Therefore, a structure capable of further improving the bonding strength and enhancing the quality of the wavelength conversion device is desired. Summary of the invention

[0013] The wavelength conversion device disclosed in the present invention comprises: a substrate composed of either copper or a copper alloy; a copper oxide layer formed on the first surface of the substrate; a bonding reinforcement layer, which is a tin oxide layer containing tin oxide and stacked on the copper oxide layer; a bonding layer arranged on the bonding reinforcement layer; and a wavelength conversion element arranged on the bonding layer.

[0014] Another wavelength conversion device disclosed in the present invention comprises: a substrate having a first surface and being composed of either copper or a copper alloy; a diffusion suppression layer containing tin oxide and being arranged on the first surface; a bonding layer arranged on the diffusion suppression layer; and a wavelength conversion element arranged on the bonding layer.

[0015] The light source device disclosed in the present invention includes: a solid light source that emits excitation light; and the wavelength conversion device of the first aspect described above that converts the wavelength of the excitation light.

[0016] The projector disclosed in the present invention includes: the light source device of the second aspect; an image light generating device that generates image light based on the light from the light source device; and a projection optical device that projects the generated image light. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram showing the structure of the projector according to the first embodiment.

[0018] Figure 2 It is a schematic diagram showing the structure of the light source device according to the first embodiment.

[0019] Figure 3 It is a cross-sectional view showing the wavelength conversion device according to the first embodiment.

[0020] Figure 4 This is a graph showing the relationship between the amount ratio of oxygen and the tensile strength when the amount of tin in the bonding strengthening layer is set to 1 in the first embodiment.

[0021] Figure 5 This is a graph showing the relationship between the thickness of the joint reinforcement layer and the tensile strength between the joint reinforcement layer and the joint layer in the first embodiment.

[0022] Figure 6 It is a figure which shows the result of component analysis of the wavelength conversion device of 1st Embodiment.

[0023] Figure 7 It is a cross-sectional view showing a wavelength conversion device according to a second embodiment.

[0024] Figure 8 It is a figure which shows the result of component analysis of the wavelength conversion device of 2nd Embodiment.

[0025] Fig. 9 This is a diagram showing a SEM image of a part of the cross section of the sample of the second embodiment.

[0026] Fig.10 This is a diagram showing a SEM image of a part of the cross section of the wavelength conversion device according to the second embodiment.

[0027] Fig.11 This is a graph showing the relationship between the amount ratio of oxygen and the tensile strength when the amount of tin in the diffusion suppression layer is set to 1 in the second embodiment.

[0028] Description of symbols

[0029] 1: projector; 30: image light generating device; 36: projection optical device; 4: light source device; 41: solid light source; 5A, 5B: wavelength conversion device; 51: substrate; 52: base material; 511: first surface; 512: second surface; 521: first surface; 522: second surface; 53: copper oxide layer; 54: heat dissipation component; 55: grease; 56: bonding reinforcement layer; 57: bonding layer; 571: first bonding layer; 572: second bonding layer; 573: third bonding layer; 58: wavelength conversion element; 581: reflection layer; 582: phosphor layer; 59: diffusion suppression layer. DETAILED DESCRIPTION

[0030] First Embodiment

[0031] Hereinafter, a first embodiment of the present disclosure will be described based on the drawings.

[0032] Schematic structure of a projector

[0033] Figure 1 1 is a schematic diagram showing the structure of the projector 1 according to the present embodiment.

[0034] The projector 1 of this embodiment projects image light corresponding to image information. Figure 1 As shown, the projector 1 includes an outer casing 2 and an image projection device 3 housed in the outer casing 2. Although not shown in the figure, the projector 1 includes a control device for controlling the operation of the projector 1, a power supply device for supplying power to electronic components of the projector 1, and a cooling device for cooling a cooling object of the projector 1.

[0035] External shell structure

[0036] The outer casing 2 has a front portion 21 , a back portion 22 , a left side surface portion 23 , a right side surface portion 24 , and a top surface portion and a bottom surface portion (not shown), and is formed in a substantially rectangular parallelepiped shape as a whole.

[0037] The front portion 21 and the back portion 22 constitute surfaces that are opposite to each other in the outer casing 2. The front portion 21 has an opening that exposes an end portion of a projection optical device 36 to be described later on the light emitting side.

[0038] The left side surface 23 and the right side surface 24 constitute surfaces on the opposite sides of the outer casing 2. The top surface and the bottom surface constitute surfaces on the opposite sides of the outer casing 2.

[0039] In the following description, three mutually orthogonal directions are defined as +X direction, +Y direction, and +Z direction. Moreover, the +Z direction is defined as the direction from the back portion 22 toward the front portion 21, the +X direction is defined as the direction from the right side face portion 24 toward the left side face portion 23, and the +Y direction is defined as the direction from the bottom face portion toward the top face portion. Although not shown in the figure, the direction opposite to the +X direction is defined as -X direction, the direction opposite to the +Y direction is defined as -Y direction, and the direction opposite to the +Z direction is defined as -Z direction. The axis along the +X direction is defined as the X axis, the axis along the +Y direction is defined as the Y axis, and the axis along the +Z direction is defined as the Z axis.

[0040] Structure of image projection device

[0041] The image projection device 3 forms image light corresponding to input image information and projects the formed image light. The image projection device 3 includes a light source device 4 , an image light generating device 30 , and a projection optical device 36 .

[0042] The light source device 4 emits illumination light toward the uniformizing optical system 31. The structure of the light source device 4 will be described in detail later.

[0043] The image light generating device 30 generates image light based on the illumination light emitted from the light source device 4. The image light generating device 30 includes a uniformizing optical system 31, a color separation optical system 32, a relay optical system 33, a light modulating device 34, and an optical component housing 35.

[0044] The uniformizing optical system 31 uniformizes the illumination light emitted from the light source device 4. The uniformized illumination light illuminates a modulation area of ​​a light modulation element 343 described later via the color separation optical system 32 and the relay optical system 33. The uniformizing optical system 31 includes two lens arrays 311 and 312, a polarization conversion element 313, and a superimposing lens 314.

[0045] The color separation optical system 32 separates the illumination light incident from the uniformization optical system 31 into red, green, and blue light. The color separation optical system 32 includes: two dichroic mirrors 321 and 323; a reflection mirror 322 for reflecting the blue light separated by the dichroic mirror 321; a lens 324 disposed between the dichroic mirror 321 and the reflection mirror 322; and a lens 325 disposed between the dichroic mirrors 321 and 323.

[0046] The relay optical system 33 is provided in the optical path of the red light which is longer than the optical paths of other colored lights, so as to suppress the loss of the red light. The relay optical system 33 includes an incident side lens 331, a relay lens 333, and reflectors 332 and 334. In the present embodiment, the red light is guided to the relay optical system 33. However, the present invention is not limited thereto, and for example, the colored light which has a longer optical path than other colored lights may be regarded as blue light, and the blue light may be guided to the relay optical system 33.

[0047] The light modulator 34 modulates the incident red, green and blue light, synthesizes the modulated light, and forms image light. The light modulator 34 includes three field lenses 341, three incident-side polarizing plates 342, three light modulators 343, three outgoing-side polarizing plates 344, and one color synthesis optical system 345, which are arranged according to the incident color light.

[0048] The light modulator 343 modulates the light from the light source device 4 to form image light. Specifically, the light modulator 343 modulates the color light incident from the incident side polarizer 342 according to the image signal and emits the modulated color light. The three light modulators 343 include a light modulator 343R that modulates red light, a light modulator 343G that modulates green light, and a light modulator 343B that modulates blue light. As the light modulator 343, a transmissive liquid crystal panel can be exemplified.

[0049] The color synthesis optical system 345 synthesizes the three color lights modulated by the light modulating elements 343R, 343G, and 343B. The image light synthesized by the color synthesis optical system 345 is incident on the projection optical device 36. In the present embodiment, the color synthesis optical system 345 is composed of a substantially rectangular cross dichroic prism, but may also be composed of a plurality of dichroic mirrors.

[0050] The optical component housing 35 accommodates the above-mentioned uniformizing optical system 31, color separation optical system 32, and relay optical system 33. In addition, a designed optical axis Ax is set in the image projection device 3, and the optical component housing 35 holds the uniformizing optical system 31, color separation optical system 32, relay optical system 33, and light modulator 34 at a predetermined position on the optical axis Ax. The light source device 4, the light modulator 34, and the projection optical device 36 are arranged at predetermined positions on the optical axis Ax.

[0051] The projection optical device 36 projects the image light incident from the light modulator 34 onto a projection surface such as a screen. That is, the projection optical device 36 projects the image light formed by the light modulator 34. The projection optical device 36 may be, for example, a lens assembly having a plurality of lenses and a lens barrel housing the plurality of lenses.

[0052] Structure of light source device

[0053] Figure 2 It is a schematic diagram showing the structure of the light source device 4.

[0054] The light source device 4 emits the illumination light WL in the +X direction toward the uniformizing optical system 31. Figure 2 As shown, the light source device 4 includes a solid light source 41, a diffuser and transmissive portion 42, a light separator 43, a first light focusing element 44, a wavelength converter 5A, a second light focusing element 45, a diffuser member 46, and a light source housing CA.

[0055] An optical axis Ax1 along the Z axis and an optical axis Ax2 along the X axis are set in the light source device 4, and the optical axis Ax1 and the optical axis Ax2 are perpendicular to each other. Optical components of the light source device 4 are arranged on the optical axis Ax1 or the optical axis Ax2.

[0056] Specifically, the solid light source 41 , the diffuse transmission portion 42 , the light separation portion 43 , the first light focusing element 44 , and the wavelength conversion device 5A are arranged on the optical axis Ax1 .

[0057] The optical diffusion member 46, the second light converging element 45, and the light separator 43 are arranged on the optical axis Ax2. That is, the light separator 43 is arranged at the intersection of the optical axis Ax1 and the optical axis Ax2.

[0058] The optical axis Ax2 is connected to the optical axis Ax of the image projection device 3 via the lens array 311 of the uniformizing optical system 31 .

[0059] Structure of solid light source

[0060] The solid light source 41 emits light in the −Z direction. The solid light source 41 includes a light emitting element 411 and a substrate 412 .

[0061] The light emitting element 411 emits blue light BL. The blue light BL is excitation light for exciting the phosphor of the wavelength conversion device 5A. The light emitting element 411 is, for example, a semiconductor laser that emits laser light having a peak wavelength of 455 nm.

[0062] The substrate 412 is fixed to the inner surface of the light source casing CA in a state of supporting the light emitting element 411. The substrate 412 receives heat from the light emitting element 411 and transfers the received heat to the heat dissipation member HD exposed to the outside of the light source casing CA.

[0063] Structure of the diffusion transmission part

[0064] The diffuser transmission part 42 diffuses the blue light BL incident from the solid light source 41 and emits light with uniform illumination distribution. The blue light BL emitted from the diffuser transmission part 42 is incident on the light separation part 43. The diffuser transmission part 42 can be exemplified by a structure having a hologram, a structure having a plurality of small lenses arranged on a plane orthogonal to the optical axis, and a structure having a rough surface through which light passes.

[0065] In addition, the light source device 4 may also use a beam homogenizing optical element having a pair of multi-lens arrays instead of the diffuser and transmissive portion 42. On the other hand, when the diffuser and transmissive portion 42 is used, the distance from the solid light source 41 to the light separator 43 can be shortened compared to when the beam homogenizing optical element is used.

[0066] Structure of light separation unit

[0067] The light separation section 43 has a function of a half mirror that allows a part of the blue light BL incident from the solid light source 41 via the diffuse transmission section 42 to pass through and reflects the other blue light BL. That is, the light separation section 43 allows a part of the blue light BL incident from the diffuse transmission section 42, i.e., the first part of the light, to pass through in the -Z direction and enter the first light focusing element 44, and reflects the other blue light BL, i.e., the second part of the light, in the -X direction and enter the second light focusing element 45.

[0068] The light separation unit 43 also has a function of a dichroic mirror that reflects the fluorescence YL incident in the +Z direction from the wavelength conversion device 5A and transmits the blue light BL incident in the +X direction from the optical diffusion member 46 .

[0069] Structure of the first light concentrating element

[0070] The first light focusing element 44 focuses the first partial light transmitted through the light separation unit 43 on the wavelength conversion device 5A. The first light focusing element 44 collimates the fluorescence YL incident from the wavelength conversion device 5A and causes the fluorescence to enter the light separation unit 43 along the +Z direction.

[0071] Schematic structure of wavelength conversion device

[0072] The wavelength conversion device 5A is a reflective wavelength conversion element that diffuses the converted light after converting the wavelength of the incident light in the direction opposite to the incident direction of the light and emits it. The light emitted from the wavelength conversion device 5A is, for example, non-polarized fluorescence YL having a peak wavelength in the range of 500nm to 700nm, and the fluorescence YL includes green light and red light. The structure of the wavelength conversion device 5A will be described in detail later.

[0073] The fluorescence YL emitted from the wavelength converter 5A passes through the first condensing element 44 along the optical axis Ax1 and enters the light separator 43. The fluorescence YL entering the light separator 43 is reflected in the +X direction by the light separator 43 and emitted to the outside of the light source device 4 along the optical axis Ax2.

[0074] Structure of the second light focusing element

[0075] The second light condensing element 45 condenses the second partial light incident from the light separator 43 onto the optical diffuser 46. The second light condensing element 45 collimates the blue light incident from the optical diffuser 46 and causes the collimated blue light to enter the light separator 43 along the +Z direction.

[0076] Structure of diffusion optics

[0077] The diffusion optical component 46 reflects and diffuses the blue light BL incident from the second light focusing element 45 at a diffusion angle substantially the same as that of the fluorescence YL emitted from the wavelength conversion device 5A, or at a diffusion angle slightly smaller than that of the fluorescence YL. That is, the diffusion optical component 46 reflects and diffuses the incident light without converting the wavelength of the incident light.

[0078] The blue light BL reflected in the +X direction by the optical diffusion member 46 passes through the second light condensing element 45 , and then passes through the light separator 43 in the +X direction to be emitted to the outside of the light source device 4 together with the fluorescence YL.

[0079] As described above, illumination light WL emitted to the outside of light source device 4 is white light mixed with blue light BL and fluorescent light YL including green light and red light. Illumination light WL is emitted from light source device 4 in the +X direction through passage CA1 of light source casing CA.

[0080] Structure of housing for light source

[0081] The light source housing CA is a housing of the light source device 4, and is one of the internal housings housed inside the outer housing 2. The light source housing CA houses the solid light source 41, the diffuse transmission portion 42, the light separation portion 43, the first light focusing element 44, the wavelength conversion device 5A, the second light focusing element 45, and the diffuse optical component 46. In the present embodiment, the light source housing CA is a sealed housing into which dust is difficult to enter. However, the present invention is not limited thereto, and the light source housing CA can be used as long as it can house the above-mentioned optical components.

[0082] The light source casing CA has a passage opening CA1. The passage opening CA1 is an opening portion through which the illumination light WL passes through the light source casing CA.

[0083] Detailed structure of wavelength conversion device

[0084] Figure 3 is a diagram showing a cross section of the wavelength conversion device 5A along the XZ plane. That is, Figure 3 1 is a diagram showing a cross section of the wavelength converter 5A along a plane defined by the −Z direction, which is the incident direction of the blue light BL with respect to the wavelength converter 5A, and the +X direction perpendicular to the −Z direction.

[0085] As described above, the wavelength conversion device 5A emits the fluorescent light YL in the +Z direction, which is converted light having a wavelength band longer than the wavelength band of the blue light BL incident in the -Z direction. Figure 3 As shown, the wavelength conversion device 5A includes a substrate 51, a heat dissipation component 54, a grease 55, a bonding reinforcement layer 56, a bonding layer 57, and a wavelength conversion element 58. In the wavelength conversion device 5A, the wavelength conversion element 58, the bonding layer 57, the bonding reinforcement layer 56, the substrate 51, the grease 55, and the heat dissipation component 54 are arranged in this order toward the -Z direction which is the incident direction of the blue light BL.

[0086] Structure of the substrate

[0087] The substrate 51 is made of copper or a copper alloy. The substrate 51 supports the wavelength conversion element 58 bonded by the bonding reinforcing layer 56 and the bonding layer 57. The substrate 51 includes a base material 52 and a copper oxide layer 53.

[0088] The substrate 52 is a plate-like body made of copper or a copper alloy. The substrate 52 supports the wavelength conversion element 58 and transfers heat transferred from the wavelength conversion element 58 to the heat dissipation member 54 via the grease 55. The substrate 52 has a first surface 521 and a second surface 522.

[0089] The first surface 521 is a surface facing the +Z direction in the substrate 52. A copper oxide layer 53 is formed on the first surface 521.

[0090] The second surface 522 is the surface of the substrate 52 on the opposite side to the first surface 521. The second surface 522 faces the heat sink 54 via the grease 55. In addition, the substrate 52 only needs to contain copper and copper alloys at a predetermined ratio or more, for example, more than 90% of the composition of the substrate 52 can be copper or copper alloys. In addition, the substrate 52 may also contain impurities.

[0091] The copper oxide layer 53 is composed of a copper oxide film formed at least on the first surface 521 of the substrate 52. The copper oxide layer 53 may be a natural oxide film naturally formed on the substrate 52, or may be an oxide film formed on the substrate 52 by a predetermined treatment. As a predetermined treatment, for example, a treatment of heating the substrate 52 to 200° C. in a constant temperature bath can be cited. The heat treatment can be performed after the substrate 52 is degreased with alcohol, immersed in a soft etching solution for a predetermined time, and dried with a dryer.

[0092] Alternatively, the copper oxide layer 53 may not be present.

[0093] Structure of heat dissipation components and grease

[0094] The heat dissipation member 54 dissipates the heat of the wavelength conversion element 58 transferred from the base material 52. The heat dissipation member 54 can be constituted by a heat sink having a plurality of fins 541, for example.

[0095] The grease 55 is a heat-conducting grease provided between the second surface 522 of the base material 52 and the heat dissipation member 54 . The grease 55 transfers the heat transferred from the second surface 522 to the heat dissipation member 54 .

[0096] In addition, if a copper substrate made of copper or a copper alloy is subjected to processing such as stamping and rolling, the copper substrate may be warped. In other words, warping may occur in the base material 52. In such a case, the heat dissipation component 54 is fixed to the base material 52 via the grease 55 with the convex direction of the warping of the base material 52 being the side of the heat dissipation component 54, thereby suppressing the reduction in the bonding strength between the base material 52 and the wavelength conversion element 58.

[0097] Structure of bonding reinforcement layer

[0098] The bonding reinforcement layer 56 is a tin oxide layer stacked on the copper oxide layer 53. The bonding reinforcement layer 56 has the function of improving the bonding strength and adhesion strength between the substrate 52 and the bonding layer 57, and further improving the bonding strength between the substrate 52 and the wavelength conversion element 58. The composition and thickness of the bonding reinforcement layer 56 will be described in detail later.

[0099] Structure of the bonding layer

[0100] The bonding layer 57 bonds the base material 52 and the wavelength conversion element 58 together with the bonding reinforcing layer 56. The bonding layer 57 includes a first bonding layer 571, a second bonding layer 572, and a third bonding layer 573.

[0101] The first bonding layer 571 is stacked on the bonding reinforcing layer 56. The first bonding layer 571 includes any one of silver (Ag), gold (Au), platinum (Pt), and palladium (Pd). In the present embodiment, the first bonding layer 571 includes silver particles.

[0102] The second bonding layer 572 is stacked on the first bonding layer 571. The second bonding layer 572 is a bonding layer containing metal nanoparticles, more specifically, a bonding layer containing nanoparticles of a noble metal. In this embodiment, the second bonding layer 572 is composed of a silver nanopaste containing silver nanoparticles.

[0103] The third bonding layer 573 is stacked on the second bonding layer 572. The third bonding layer 573 contains any noble metal of silver, gold, platinum, and palladium. In this embodiment, the third bonding layer 573 contains silver particles that are easily bonded to the silver nanoparticles contained in the second bonding layer 572 during firing, similarly to the first bonding layer 571. That is, the first bonding layer 571 and the third bonding layer 573 are auxiliary bonding layers for the second bonding layer 572 as the main bonding layer.

[0104] Such a bonding layer 57 is fired at, for example, 200° C., whereby the silver particles of each of the first bonding layer 571 and the third bonding layer 573 and the silver nanoparticles of the second bonding layer 572 are diffusion-bonded by thermocompression bonding. Thus, the substrate 52 and the wavelength conversion element 58 are bonded.

[0105] Structure of wavelength conversion element

[0106] The wavelength conversion element 58 is provided at the end in the +Z direction into which the blue light BL is incident in the wavelength conversion device 5A. The wavelength conversion element 58 includes a reflective layer 581 and a fluorescent layer 582 .

[0107] The reflective layer 581 is stacked on the third bonding layer 573. That is, the reflective layer 581 is arranged on the substrate 52 side in the wavelength conversion element 58. The reflective layer 581 reflects light incident from the phosphor layer 582 toward the phosphor layer 582. The reflective layer 581 may be composed of a multilayer film including a total reflection film.

[0108] The phosphor layer 582 is stacked on the side opposite to the substrate 52 with respect to the reflective layer 581. That is, the phosphor layer 582 is stacked on the incident side of the blue light BL with respect to the reflective layer 581. The phosphor layer 582 contains a phosphor that is excited by the incident blue light BL. As the phosphor, for example, a YAG:Ce phosphor containing cerium as an activator can be cited. The blue light BL is directly incident on the phosphor layer 582 from the first focusing element 44, and the phosphor layer 582 emits fluorescence YL by the incidence of the blue light BL.

[0109] Composition of the bonding reinforcement layer

[0110] When selecting the material of the bonding reinforcement layer 56, the inventors of the present application formed a bonding reinforcement layer 56 containing tin oxide and a bonding reinforcement layer 56 containing nickel, and measured the tensile strength when using each bonding reinforcement layer 56. The unit of tensile strength is N.

[0111] In the measurement of tensile strength, a target sample in which a bonding reinforcing layer 56 and a bonding layer 57 as tin oxide layers were formed on a substrate 52, and a comparative sample in which a bonding reinforcing layer 56 and a bonding layer 57 as nickel layers were formed on a substrate 52 were prepared. Then, the substrate 52 of each sample was fixed, and a jig was bonded to the bonding layer 57 of each sample with an area of ​​3 mm square using an adhesive, and then the jig was stretched in a direction away from the substrate 52, thereby measuring the tensile strength of each sample.

[0112] In the comparative sample, the tensile strength of the nickel layer after vapor deposition was 248 N. In contrast, in the target sample, the tensile strength of the tin oxide layer after vapor deposition was 560 N.

[0113] Next, the inventors of the present application measured the tensile strength of each sample after subjecting each sample to a thermal shock test in which cooling to -20°C and heating to 100°C were alternately repeated 500 times.

[0114] The tensile strength of the comparative sample after the thermal shock test was 104 N. In contrast, the tensile strength of the target sample after the thermal shock test was 458 N.

[0115] This shows that the bonding strengthening layer 56 is more preferably a tin oxide layer than a nickel layer.

[0116] Composition of tin oxide in the bonding strengthening layer

[0117] The inventors of the present application studied the composition of tin oxide contained in the bonding reinforcement layer 56 on the basis of improving the bonding strength between the substrate 52 and the bonding layer 57 by using the bonding reinforcement layer 56. That is, the inventors of the present application changed the molar composition ratio of tin oxide, measured the bonding strength between the substrate 52 and the bonding layer 57, and studied the appropriate molar composition ratio of tin oxide in the bonding reinforcement layer 56. In addition, the measurement method of the tensile strength measured as the bonding strength is the same as the measurement method using the jig described above.

[0118] Figure 4 This is a graph showing the relationship between the ratio of the amount of oxygen in the bonding reinforcing layer 56 when the amount of tin is set to 1 and the tensile strength of the bonding layer 57 .

[0119] like Figure 4As shown in FIG. 1 , when the amount of tin in the bonding reinforcement layer 56 is set to 1, the amount of oxygen is set to the amount of oxygen, and when the amount of oxygen is 1, that is, when substantially all of the tin oxide contained in the bonding reinforcement layer 56 is tin monoxide, the tensile strength is 142 N. In addition, the crystal structure of tin monoxide is tetragonal.

[0120] On the other hand, when the molar ratio of oxygen is 1.3, the tensile strength is 397 N, and when the molar ratio of oxygen is 1.7, the tensile strength is 370 N. That is, it is known that the tensile strength in the case where the tin oxide constituting the bonding reinforcement layer 56 is tin monoxide and tin dioxide is higher than the tensile strength in the case where substantially all of the tin oxide constituting the bonding reinforcement layer 56 is tin monoxide. In addition, the crystal structure of tin dioxide is a rutile structure.

[0121] On the other hand, when the amount ratio of oxygen to tin in the bonding reinforcing layer 56 is 2, the tensile strength is 400 N. That is, it is found that the tensile strength is highest when substantially all of the tin oxide contained in the bonding reinforcing layer 56 is tin dioxide.

[0122] According to the measurement results of such tensile strength, when the tensile strength required in the case where a bonding reinforcement layer 56 containing tin oxide is provided in the wavelength conversion device 5A is set to be greater than 300N, by making the molar ratio of oxygen greater than 1.3, the substrate 52 and the bonding layer 57 can be firmly bonded, and the wavelength conversion element 58 can be firmly bonded to the substrate 52 through the bonding reinforcement layer 56 and the bonding layer 57.

[0123] Tensile strength as a function of the thickness of the bond reinforcement layer

[0124] Generally, when a thin film is formed on a film-forming object using a sputtering device or an evaporation device, first, an island-shaped thin film is formed on the surface of the film-forming object, and then each island-shaped thin film is bonded to each other and grows into a continuous film. In contrast, the inventors of the present application have found that if the bonding reinforcement layer 56 as a tin oxide layer is in an island shape, the precious metal such as silver contained in the bonding layer 57 is in direct contact with the copper oxide layer 53, and the adhesion between the bonding reinforcement layer 56 and the bonding layer 57 is not good. That is, the inventors of the present application have found that in order to ensure the adhesion between the bonding reinforcement layer 56 and the bonding layer 57, the bonding reinforcement layer 56 and the bonding layer 57 need to be completely in contact in the mutually opposing regions.

[0125] Figure 5 : is a graph showing the relationship between the thickness of the bonding reinforcement layer 56 and the tensile strength between the bonding reinforcement layer 56 and the bonding layer 57. The thickness of the bonding reinforcement layer 56 is the dimension along the incident direction of the blue light BL with respect to the wavelength conversion device 5A, that is, the dimension along the -Z direction. The same is true for other layers.

[0126] Based on the above findings, the inventors of the present application changed the thickness of the bonding reinforcement layer 56 and measured the tensile strength between each bonding reinforcement layer 56 and the bonding layer 57. The measurement of the tensile strength was the same as the measurement method using the jig described above.

[0127] According to the relationship between the thickness of the bonding reinforcement layer 56 and the above tensile strength Figure 5 It is known that sufficient tensile strength can be ensured when the thickness of the bonding reinforcement layer 56 reaches 10 nm. In other words, when the thickness of the bonding reinforcement layer 56 reaches 10 nm, the tin oxide film becomes a continuous film, and it is estimated that the bonding reinforcement layer 56 and the bonding layer 57 are completely in contact in the mutually opposing region.

[0128] Furthermore, it is found that when the thickness of the bonding reinforcement layer 56 is 20 nm or more, even if variations occur in the film forming step or other steps, sufficient tensile strength and sufficient adhesion can be ensured.

[0129] Therefore, from the viewpoint of the adhesion between the bonding reinforcing layer 56 and the bonding layer 57 , the thickness of the bonding reinforcing layer 56 is preferably 10 nm or more, and more preferably 20 nm or more.

[0130] Diffusion suppression of copper atoms by the bonding strengthening layer

[0131] Although detailed illustrations are omitted, the inventors of the present application have found that the result of component analysis of the bonding layer stacked on the copper substrate and fired is that copper atoms move from the base material 52 and the copper oxide layer 53 to the surface of the first bonding layer 571 in the bonding layer 57. Specifically, it is known that when each layer is formed by vapor deposition, the silver film is composed of a plurality of crystals, but in this case, copper atoms easily diffuse from the crystal interface of the silver film to the inside of the silver film and precipitate on the surface of the silver film.

[0132] The fired bonding material such as the second bonding layer 572 is composed of silver nanoparticles and a protective agent. When the protective agent is volatilized by heating, the silver nanoparticles of the second bonding layer 572 diffuse with the silver particles of the first bonding layer 571 and the third bonding layer 573 to form metal bonding with each other. If copper atoms are present on the silver film, the metal bonding between the silver nanoparticles and the silver particles is hindered, so the bonding between the substrate 52 and the bonding layer 57 is hindered, which further becomes a cause of reducing the bonding strength between the substrate 52 and the wavelength conversion element 58.

[0133] Based on such findings, the inventors of the present application have determined that it is necessary to provide a protective layer between the substrate 51 having the base material 52 and the copper oxide layer 53 and the bonding layer 57 to suppress the diffusion of copper atoms into the bonding layer 57 .

[0134] In contrast, in the wavelength conversion device 5A, as described above, a bonding reinforcement layer 56 containing tin oxide is provided as a diffusion suppression layer for copper atoms between the copper oxide layer 53 formed on the substrate 52 and the bonding layer 57 containing silver particles and silver nanoparticles. It is known that such a bonding reinforcement layer 56 can suppress the diffusion of copper atoms into the bonding layer 57.

[0135] Figure 6 1 is a diagram showing the results of component analysis in the +Z direction of the base material 52 , the copper oxide layer 53 , the junction reinforcing layer 56 , and the junction layer 57 of the wavelength conversion device 5A.

[0136] Specifically, the results of the component analysis are shown in Figure 6 As shown, it can be seen that the copper atoms from the substrate 52 and the copper oxide layer 53 diffuse from the copper oxide layer 53 to a thickness of 25 nm in the bonding reinforcement layer 56 having a thickness of 50 nm containing tin oxide. In other words, it can be seen that it is difficult for the copper atoms from the substrate 52 and the copper oxide layer 53 to advance beyond a position of 25 nm from the surface of the bonding reinforcement layer 56 on the substrate 52 side toward the bonding layer 57 on the side opposite to the substrate 52 relative to the bonding reinforcement layer 56.

[0137] Therefore, by setting the thickness of the bonding reinforcement layer 56 disposed between the substrate 52 and the bonding layer 57 to be greater than 25 nm, preferably greater than 30 nm, it is possible to prevent the diffusion of copper atoms into the bonding layer 57. That is, from the perspective of suppressing the diffusion of copper atoms into the bonding layer 57 by using the bonding reinforcement layer 56, the thickness of the bonding reinforcement layer 56 is preferably greater than 25 nm, more preferably greater than 30 nm.

[0138] This can improve the bonding strength between the substrate 52 and the bonding layer 57, and further improve the bonding strength of the wavelength conversion element 58 to the substrate 52. In this case, the bonding reinforcement layer 56 functions as a diffusion suppression layer that suppresses diffusion of copper atoms.

[0139] Effects of the First Embodiment

[0140] The projector 1 according to the present embodiment described above has the following effects.

[0141] The projector 1 includes a light source device 4, an image light generating device 30, and a projection optical device 36. The image light generating device 30 generates image light based on light from the light source device 4, and the projection optical device 36 projects the generated image light.

[0142] The light source device 4 includes a solid light source 41 that emits excitation light and a wavelength conversion device 5A that converts the wavelength of the excitation light.

[0143] The wavelength conversion device 5A includes a substrate 52 , a copper oxide layer 53 , a bonding reinforcing layer 56 , a bonding layer 57 , and a wavelength conversion element 58 .

[0144] The substrate 52 is made of either copper or a copper alloy.

[0145] The copper oxide layer 53 is formed on the first surface 521 of the substrate 52 .

[0146] The junction strengthening layer 56 is a tin oxide layer that contains tin oxide and is stacked on the copper oxide layer 53 .

[0147] The bonding layer 57 is disposed on the bonding reinforcement layer 56 .

[0148] The wavelength conversion element 58 is disposed on the bonding layer 57 .

[0149] According to such a structure, since the copper oxide layer 53 is formed on the first surface 521 , it is possible to suppress the degradation of the base material 52 formed of copper or a copper alloy.

[0150] In addition, by stacking the bonding reinforcement layer 56 as a tin oxide layer on the copper oxide layer 53, the adhesion between the bonding reinforcement layer 56 and the bonding layer 57 can be improved, thereby improving the adhesion between the substrate 52 and the bonding layer 57. In addition, by the bonding reinforcement layer 56 functioning as a diffusion suppression layer, the movement of copper atoms from the substrate 52 and the copper oxide layer 53 to the bonding layer 57 can be suppressed.

[0151] Therefore, the bonding strength between the wavelength conversion element 58 and the substrate 52 by the bonding layer 57 can be improved, and a stable wavelength conversion device 5A can be formed. In addition, this can form a light source device 4 that can stably emit light, and further, a projector 1 that can stably project image light.

[0152] In the wavelength conversion device 5A, the wavelength conversion element 58 includes a reflection layer 581 and a phosphor layer 582. The reflection layer 581 is disposed on the substrate 52 side in the wavelength conversion element 58, and the phosphor layer 582 is stacked on the reflection layer 581. Specifically, the phosphor layer 582 is a layer containing a phosphor excited by incident light, and is stacked on the side opposite to the substrate 52 with respect to the reflection layer 581.

[0153] According to such a configuration, the wavelength conversion device 5A can be configured as a stable reflection-type wavelength conversion device.

[0154] In the wavelength conversion device 5A, the bonding layer 57 includes a first bonding layer 571 which is stacked on the bonding reinforcing layer 56 and contains any one of silver, gold, platinum, and palladium. In the present embodiment, the first bonding layer 571 contains silver.

[0155] Here, the tin oxide layer constituting the bonding reinforcing layer 56 also has high adhesion to the bonding layer 57 including the first bonding layer 571, so that the bonding strength between the wavelength conversion element 58 and the substrate 52 by the bonding layer 57 can be improved. Therefore, a stable wavelength conversion device 5A can be formed.

[0156] In the wavelength conversion device 5A, the bonding layer 57 includes, in addition to the first bonding layer 571, a second bonding layer 572 stacked on the first bonding layer 571 and containing silver nanoparticles, and a third bonding layer 573 stacked on the second bonding layer 572 and containing any one of silver, gold, platinum and palladium. In the present embodiment, the third bonding layer 573 contains silver like the first bonding layer 571.

[0157] According to such a structure, the bonding layer 57 includes the second bonding layer 572 and the third bonding layer 573 in addition to the first bonding layer 571, thereby improving the bonding strength between the wavelength conversion element 58 and the substrate 52 by the bonding layer 57. Therefore, a stable wavelength conversion device 5A can be formed.

[0158] In the wavelength conversion device 5A, the thickness of the bonding strengthening layer 56 is 10 nm or more.

[0159] According to such a structure, the bonding reinforcing layer 56 containing tin oxide can be formed as a continuous layer, and the bonding strength with the bonding layer 57 can be improved. Therefore, a stable wavelength conversion device 5A can be configured.

[0160] In the wavelength conversion device 5A, the thickness of the bonding strengthening layer 56 is 20 nm or more.

[0161] According to such a structure, the bonding strength between the bonding reinforcing layer 56 and the bonding layer 57 can be further improved, and the wavelength conversion element 58 can be stably bonded to the base material 52. Therefore, a stable wavelength conversion device 5A can be configured.

[0162] In the wavelength conversion device 5A, in the molar composition ratio of the tin oxide film constituting the junction strengthening layer 56 , when the substance amount of tin is 1, the substance amount of oxygen is 1.3 or more and 2.0 or less.

[0163] According to such a structure, the adhesion strength between the bonding reinforcing layer 56, which is a tin oxide layer, and the bonding layer 57 can be increased, so that the wavelength conversion element 58 can be stably bonded to the substrate 52. Therefore, a stable wavelength conversion device 5A can be configured.

[0164] Second Embodiment

[0165] Next, the second embodiment of the present disclosure is described. The wavelength conversion device of this embodiment has the same structure as the wavelength conversion device 5A of the first embodiment, but is different in that a diffusion suppression layer 59 is provided instead of the bonding reinforcement layer 56 of the wavelength conversion device 5A. In addition, in the following description, the same reference numerals are attached to the parts that are the same or substantially the same as the parts that have been described, and the description thereof is omitted.

[0166] The light source device of this embodiment has a wavelength conversion device 5A instead of the wavelength conversion device 5A. Figure 7 The wavelength converter 5B shown has the same structure and function as the light source device 4 of the first embodiment. The wavelength converter 5B has the same structure and function as the wavelength converter 5A of the first embodiment except that it has a diffusion suppression layer 59 instead of the bonding reinforcement layer 56 .

[0167] Detailed structure of wavelength conversion device

[0168] Figure 7 is a diagram showing a cross section of the wavelength conversion device 5B along the XZ plane. That is, Figure 7 1 is a diagram showing a cross section of the wavelength converter 5B along a plane defined by the −Z direction, which is the incident direction of the blue light BL with respect to the wavelength converter 5B, and the +X direction perpendicular to the −Z direction.

[0169] As described above, the wavelength conversion device 5B emits the fluorescent light YL in the +Z direction, which is converted light having a wavelength band longer than the wavelength band of the blue light BL incident in the -Z direction. Figure 7 As shown, the wavelength conversion device 5B includes a substrate 51, a heat dissipation component 54, a grease 55, a diffusion suppression layer 59, a bonding layer 57, and a wavelength conversion element 58. In the wavelength conversion device 5B, the wavelength conversion element 58, the bonding layer 57, the diffusion suppression layer 59, the substrate 51, the grease 55, and the heat dissipation component 54 are arranged in this order toward the -Z direction which is the incident direction of the blue light BL.

[0170] Structure of the substrate

[0171] The substrate 51 is made of either copper or a copper alloy. The substrate 51 supports the wavelength conversion element 58 bonded by the diffusion suppression layer 59 and the bonding layer 57. The substrate 51 has a first surface 511 and a second surface 512. The first surface 511 is a surface of the substrate 51 in the +Z direction, and the second surface 512 is a surface on the opposite side of the first surface 511.

[0172] The substrate 51 includes a base material 52 and a copper oxide layer 53. The second surface 522 is a surface of the base material 52 on the opposite side to the first surface 521 and constitutes the second surface 512. The copper oxide layer 53 constitutes the first surface 511.

[0173] Structure of the diffusion suppression layer

[0174] The diffusion suppression layer 59 is a tin oxide layer stacked on the copper oxide layer 53. That is, the diffusion suppression layer 59 is stacked on the first surface 511. The diffusion suppression layer 59 has a function of suppressing the diffusion of copper atoms from the substrate 51 to the bonding layer 57. Thus, in the wavelength conversion device 5B, the adhesion between the diffusion suppression layer 59 and the bonding layer 57 is improved, and the bonding strength between the substrate 52 and the wavelength conversion element 58 is further improved. The thickness and composition of the diffusion suppression layer 59 will be described in detail later.

[0175] Structure of the bonding layer

[0176] The bonding layer 57 bonds the diffusion suppression layer 59 and the wavelength conversion element 58, and further bonds the substrate 51 and the wavelength conversion element 58. The bonding layer 57 includes a first bonding layer 571, a second bonding layer 572, and a third bonding layer 573.

[0177] The first bonding layer 571 is stacked on the diffusion suppression layer 59. The bonding layer 57 is fired at, for example, 200° C., whereby the silver particles of the first bonding layer 571 and the third bonding layer 573 are diffusion-bonded to the silver nanoparticles of the second bonding layer 572 by thermocompression bonding. Thus, the diffusion suppression layer 59 formed on the substrate 51 is bonded to the wavelength conversion element 58, and further, the substrate 51 is bonded to the wavelength conversion element 58.

[0178] Diffusion suppression layer suppresses the diffusion of copper atoms

[0179] Although detailed illustrations are omitted, the inventors of the present application conducted a component analysis on the bonding layer stacked on the copper substrate and fired, and found that copper atoms moved from the substrate 52 and the copper oxide layer 53 to the surface of the first bonding layer 571 in the bonding layer 57. In detail, it is known that when each layer is formed by evaporation, the silver film is composed of a plurality of crystals, but in this case, copper atoms easily diffuse from the crystal interface of the silver film to the inside of the silver film and precipitate on the surface of the silver film.

[0180] The sintered bonding material such as the second bonding layer 572 is composed of silver nanoparticles and a protective agent. When the protective agent is volatilized by heating, the silver nanoparticles of the second bonding layer 572 diffuse with the silver particles of the first bonding layer 571 and the third bonding layer 573 to form metal bonding with each other. If copper atoms are present on the silver film, the metal bonding between the silver nanoparticles and the silver particles is hindered, so the bonding between the substrate 51 and the bonding layer 57 is hindered, which further becomes a cause of reducing the bonding strength between the substrate 51 and the wavelength conversion element 58.

[0181] Based on such findings, the inventors of the present application have determined that it is necessary to provide a protective layer between the substrate 51 having the base material 52 and the copper oxide layer 53 and the bonding layer 57 to suppress the diffusion of copper atoms into the bonding layer 57 .

[0182] In contrast, in the wavelength conversion device 5B, as described above, a diffusion suppression layer 59 containing tin oxide is provided as a diffusion suppression layer for copper atoms between the copper oxide layer 53 formed on the substrate 52 and the bonding layer 57 containing silver particles and silver nanoparticles. It is known that such a diffusion suppression layer 59 can suppress the diffusion of copper atoms into the bonding layer 57.

[0183] Figure 8 1 is a diagram showing the results of component analysis in the +Z direction of the base material 52 , the copper oxide layer 53 , the diffusion suppression layer 59 , and the bonding layer 57 of the wavelength conversion device 5B.

[0184] Specifically, the results of the component analysis are shown in Figure 8 As shown, it can be seen that the copper atoms from the substrate 52 and the copper oxide layer 53 diffuse from the copper oxide layer 53 to a thickness of 25 nm in the diffusion suppression layer 59 having a thickness of 50 nm containing tin oxide. In other words, it can be seen that it is difficult for the copper atoms from the substrate 52 and the copper oxide layer 53 to advance beyond a position of 25 nm from the surface of the diffusion suppression layer 59 on the substrate 52 side toward the bonding layer 57 on the side opposite to the substrate 52 with respect to the diffusion suppression layer 59.

[0185] Therefore, when the thickness of the diffusion suppression layer 59 is defined as the dimension along the incident direction of the blue light BL with respect to the wavelength conversion device 5B, that is, the -Z direction, the diffusion suppression layer 59 disposed between the substrate 52 and the bonding layer 57 is set to have a thickness of 25 nm or more, preferably 30 nm or more, thereby preventing copper atoms from diffusing into the bonding layer 57. That is, from the viewpoint that the diffusion suppression layer 59 suppresses the diffusion of copper atoms into the bonding layer 57, the thickness of the diffusion suppression layer 59 is preferably 25 nm or more, and more preferably 30 nm or more.

[0186] This can improve the bonding strength between the substrate 51 and the bonding layer 57 , and further improve the bonding strength of the wavelength conversion element 58 to the substrate 51 .

[0187] Fig. 9 : is a figure which shows the SEM (Scanning Electron Microscope: scanning electron microscope) image of a part of the cross section of the sample SM, Fig.10 It is a diagram showing a SEM image of a part of the cross section of the wavelength conversion device 5B.

[0188] The inventors of the present application compared a SEM image showing a portion of the cross section of the sample SM with a SEM image showing a portion of the cross section of the wavelength converter 5B. The sample SM has the same structure as the wavelength converter 5B except that the diffusion suppression layer 59 is not provided.

[0189] like Fig. 9 As shown, in the sample SM, since there is no diffusion suppression layer 59, it can be considered that the copper atoms from the substrate 51 diffuse to the surface of the bonding layer 57 on the substrate 51 side. Therefore, it can be seen that in the sample SM, the silver nanoparticles cannot diffuse to the surface of the bonding layer 57 on the substrate 51 side, and the bonding layer 57 cannot be sufficiently adhered to the substrate 51.

[0190] In contrast, Fig.10 As shown, in the wavelength conversion device 5B, it can be considered that the diffusion of copper atoms to the bonding layer 57 is suppressed by the diffusion suppression layer 59. Therefore, since the silver nanoparticles can diffuse to the surface of the bonding layer 57 on the substrate 51 side, it can be known that the bonding layer 57 can be fully adhered to the diffusion suppression layer 59 formed on the substrate 51. As a result, the bonding strength between the substrate 51 and the wavelength conversion element 58 provided on the bonding layer 57 can be improved.

[0191] Composition of tin oxide in the diffusion suppression layer

[0192] The inventors of the present application studied the composition of tin oxide contained in the diffusion suppression layer 59 on the basis of suppressing the diffusion of copper atoms by the diffusion suppression layer 59. That is, the inventors changed the molar composition ratio of tin oxide, measured the bonding strength between the substrate 52 and the bonding layer 57, and studied the appropriate molar composition ratio of tin oxide in the diffusion suppression layer 59.

[0193] In addition, in the measurement of tensile strength, a sample is formed on a substrate 51 with a diffusion suppression layer 59 and a bonding layer 57. The substrate 51 is fixed, and a jig is bonded to the bonding layer 57 with an area of ​​3 mm square using an adhesive. The jig is then stretched in a direction away from the substrate 51, thereby measuring the tensile strength of the sample.

[0194] Fig.11 This is a graph showing the relationship between the ratio of the amount of oxygen in the diffusion suppression layer 59 when the amount of tin is set to 1 and the tensile strength of the bonding layer 57 .

[0195] like Fig.11 As shown in FIG. 1 , when the amount of tin in the diffusion suppression layer 59 is set to 1, the amount of oxygen is set to the amount of oxygen, and when the amount of oxygen is 1.0, that is, when substantially all of the tin oxide contained in the diffusion suppression layer 59 is tin monoxide, the tensile strength is 142 N. In addition, the crystal structure of tin monoxide is tetragonal.

[0196] On the other hand, when the molar ratio of oxygen was 1.3, the tensile strength was 397 N, and when the molar ratio of oxygen was 1.7, the tensile strength was 370 N. That is, it is known that the tensile strength when the tin oxide constituting the diffusion suppression layer 59 is tin monoxide and tin dioxide is higher than the tensile strength when substantially all of the tin oxide constituting the diffusion suppression layer 59 is tin monoxide. In addition, the crystal structure of tin dioxide is a rutile structure.

[0197] On the other hand, when the amount ratio of oxygen to tin in the diffusion suppression layer 59 is 2, the tensile strength is 400 N. That is, it is found that the tensile strength is highest when substantially all of the tin oxide contained in the diffusion suppression layer 59 is tin dioxide.

[0198] From the measurement results of the tensile strength, it is known that if the diffusion suppression layer 59, which is a tin oxide layer, contains tin dioxide, it is believed that the diffusion of copper atoms from the substrate 51 to the bonding layer 57 can be effectively suppressed, and the adhesion between the diffusion suppression layer 59 and the bonding layer 57 can be further improved compared to the case where the tin oxide contained in the diffusion suppression layer 59 is only tin oxide. For example, it is believed that the diffusion suppression layer 59 can effectively suppress the diffusion of copper atoms from the substrate 51 when the molar ratio of oxygen is 1.1 or more and 2.0 or less.

[0199] Specifically, when the above-mentioned tensile strength required in the case of providing a diffusion suppression layer 59 containing tin oxide in the wavelength conversion device 5B is set to 200N or more, by making the amount ratio of oxygen greater than 1.1 and less than 2.0, the diffusion suppression layer 59 formed on the substrate 52 can be firmly bonded to the bonding layer 57, and the wavelength conversion element 58 can be firmly bonded to the substrate 52.

[0200] When the required tensile strength is set to 300 N or more, the diffusion suppression layer 59 and the bonding layer 57 can be firmly bonded to each other by setting the molar ratio of oxygen to 1.3 or more and 2.0 or less, and the wavelength conversion element 58 can be firmly bonded to the substrate 51 .

[0201] Effects of the Second Embodiment

[0202] The projector 1 according to the present embodiment described above has the following effects.

[0203] The projector includes a light source device 4 , an image light generating device 30 , and a projection optical device 36 .

[0204] The image light generating device 30 generates image light based on the light from the light source device 4 , and the projection optical device 36 projects the generated image light.

[0205] The light source device 4 includes a solid light source 41 that emits blue light BL as excitation light, and a wavelength conversion device 5B that converts the wavelength of the blue light BL emitted from the solid light source 41 .

[0206] The wavelength conversion device 5B includes a substrate 51 , a diffusion suppression layer 59 , a bonding layer 57 , and a wavelength conversion element 58 .

[0207] The substrate 51 is made of copper or a copper alloy. The substrate 51 has a first surface 511 .

[0208] Diffusion suppression layer 59 contains tin oxide and is disposed on first surface 511 .

[0209] The bonding layer 57 is disposed on the diffusion suppression layer 59 .

[0210] The wavelength conversion element 58 is disposed on the bonding layer 57 .

[0211] According to such a structure, in the process of bonding the wavelength conversion element 58 to the substrate 51 through the bonding layer 57, the diffusion suppression layer 59 containing tin oxide can suppress the diffusion of copper atoms from the substrate 51 to the bonding layer 57. As a result, it is possible to suppress the reduction in the bonding force of the bonding layer 57 due to the diffusion of copper atoms into the bonding layer 57. Therefore, the bonding strength between the wavelength conversion element 58 and the substrate 51 based on the bonding layer 57 can be improved, and a stable wavelength conversion device 5B can be formed. As a result, the life of the light source device 4 can be extended. In addition, a projector 1 that can stably project image light can be formed, and the life of the projector 1 can be further extended.

[0212] In the wavelength conversion device 5B, the wavelength conversion element 58 includes a reflective layer 581 disposed on the substrate 51 side of the wavelength conversion element 58 and a fluorescent layer 582 stacked on the side opposite to the substrate 51 with respect to the reflective layer 581 .

[0213] According to such a configuration, the wavelength conversion device 5B can be configured as a stable reflection-type wavelength conversion device.

[0214] In the wavelength conversion device 5B, in the molar composition ratio of tin oxide constituting the diffusion suppression layer 59 , when the substance amount of tin is 1, the substance amount of oxygen is 1.1 or more and 2.0 or less.

[0215] According to such a structure, the diffusion suppression layer 59 contains tin dioxide. The diffusion suppression layer 59 containing tin dioxide can effectively suppress the diffusion of copper atoms, thereby improving the adhesion between the diffusion suppression layer 59 and the bonding layer 57. Therefore, the wavelength conversion element 58 and the substrate 51 can be stably bonded, and a stable wavelength conversion device 5B can be formed.

[0216] In the wavelength conversion device 5B, the tin oxide constituting the diffusion suppression layer 59 includes tin oxide having a rutile crystal structure.

[0217] Tin oxide having a rutile crystal structure is tin dioxide. Therefore, the diffusion suppression layer 59 contains tin dioxide. As described above, the diffusion suppression layer 59 containing tin dioxide can effectively suppress the diffusion of copper atoms, thereby improving the adhesion between the diffusion suppression layer 59 and the bonding layer 57. Therefore, the wavelength conversion element 58 and the substrate 51 can be stably bonded, and a stable wavelength conversion device 5B can be formed.

[0218] In the wavelength conversion device 5B, the thickness of the diffusion suppression layer 59 is 30 nm or more.

[0219] According to such a structure, it is possible to reliably suppress the diffusion of copper atoms into the bonding layer 57. Therefore, the bonding strength between the wavelength conversion element 58 and the substrate 51 by the bonding layer 57 can be improved, and a stable wavelength conversion device 5B can be configured.

[0220] In the wavelength conversion device 5B, the bonding layer 57 contains any one of silver, gold, platinum, and palladium, and has a first bonding layer 571 stacked on the diffusion suppression layer 59. In the present embodiment, the first bonding layer 571 contains silver.

[0221] According to such a structure, it is possible to suppress the diffusion of copper atoms from the substrate 51 to the first bonding layer 571 stacked on the diffusion suppression layer 59 .

[0222] Furthermore, the tin oxide layer constituting the diffusion suppression layer 59 has high adhesion to the bonding layer 57 including the first bonding layer 571, and thus can improve the bonding strength between the wavelength conversion element 58 and the substrate 51 by the bonding layer 57. Therefore, a stable wavelength conversion device 5B can be configured.

[0223] In the wavelength conversion device 5B, the bonding layer 57 includes a second bonding layer 572 and a third bonding layer 573 in addition to the first bonding layer 571 .

[0224] The second bonding layer 572 is stacked on the first bonding layer 571 and contains silver nanoparticles.

[0225] The third bonding layer 573 is stacked on the second bonding layer 572 and contains any one of silver, gold, platinum, and palladium. In this embodiment, the third bonding layer 573 contains silver.

[0226] According to such a structure, the bonding layer 57 includes the second bonding layer 572 and the third bonding layer 573 in addition to the first bonding layer 571, thereby improving the bonding strength between the wavelength conversion element 58 and the substrate 51 by the bonding layer 57. Therefore, a stable wavelength conversion device 5B can be formed.

[0227] In the wavelength conversion device 5B, the substrate 51 includes a base material 52 and a copper oxide layer 53 .

[0228] The base material 52 is made of either copper or a copper alloy, and the copper oxide layer 53 is formed on the base material 52 . Furthermore, at least a portion of the first surface 511 of the substrate 51 is made of the copper oxide layer 53 .

[0229] According to such a structure, the adhesion of the diffusion suppression layer 59 to the substrate 51 can be improved by the copper oxide layer 53 , and thus the bonding strength of the wavelength conversion element 58 to the substrate 51 can be improved.

[0230] Variations of the Embodiments

[0231] The present disclosure is not limited to the above-described embodiments, and modifications and improvements within the scope that can achieve the object of the present disclosure are included in the present disclosure.

[0232] In the above embodiment, the wavelength conversion element 58 includes: a reflective layer 581 disposed on the substrate 52 side of the wavelength conversion element 58; and a phosphor layer 582 stacked on the side of the reflective layer 581 opposite to the substrate 52. That is, the wavelength conversion devices 5A and 5B are reflective wavelength conversion devices that emit converted light after converting the wavelength of the excitation light in the direction opposite to the incident direction of the excitation light. However, this is not limited to this, and the reflective layer 581 may not be included in the wavelength conversion element 58. That is, the wavelength conversion devices 5A and 5B may also be configured as transmissive wavelength conversion devices that emit converted light along the incident direction of the excitation light.

[0233] In the above-mentioned embodiment, the bonding layer 57 has a first bonding layer 571 which is arranged on the side opposite to the substrate 52 with respect to the bonding reinforcement layer 56 or the diffusion suppression layer 59 and is stacked on the bonding reinforcement layer 56. Moreover, the first bonding layer 571 contains any one of silver, gold, platinum and palladium. However, it is not limited thereto, and the bonding layer 57 may also contain metals other than silver, gold, platinum and palladium. In addition, the bonding layer 57 may also have only the first bonding layer 571.

[0234] In the above embodiment, the bonding layer 57 includes, in addition to the first bonding layer 571, a second bonding layer 572 stacked on the first bonding layer 571 and containing silver nanoparticles; and a third bonding layer 573 stacked on the second bonding layer 572 and containing any one of silver, gold, platinum and palladium. However, this is not limited to the above, and the second bonding layer 572 may also contain metal nanoparticles other than silver nanoparticles. In addition, the third bonding layer 573 may contain metals other than silver, gold, platinum and palladium, and may also contain a metal different from the first bonding layer 571. Moreover, the bonding layer 57 may not include the third bonding layer 573, but include the first bonding layer 571 and the second bonding layer 572. In addition, the bonding layer 57 may also include a bonding layer having other characteristics different from the first bonding layer 571, the second bonding layer 572 and the third bonding layer 573.

[0235] In the first embodiment, the thickness of the bonding reinforcement layer 56 is 10 nm or more, preferably 20 nm or more, but the present invention is not limited thereto, and the thickness of the bonding reinforcement layer 56 may be less than 10 nm as long as the bonding strength between the substrate and the wavelength conversion element based on the bonding layer can be sufficiently ensured.

[0236] In the second embodiment, the thickness of the diffusion suppression layer 59 is 25 nm or more, preferably 30 nm or more. However, the present invention is not limited thereto, and the thickness of the diffusion suppression layer 59 may be less than 25 nm as long as the migration of copper atoms from the substrate 51 to the bonding layer 57 can be suppressed.

[0237] In the first embodiment described above, in the molar composition ratio of tin oxide constituting the bonding reinforcement layer 56, when the amount of tin substance is set to 1, the amount of oxygen substance is greater than 1.3 and less than 2.0. That is, the bonding reinforcement layer 56 contains tin dioxide. Regarding the molar composition ratio of tin oxide constituting such a bonding reinforcement layer 56, as long as the bonding strength between the bonding reinforcement layer and the bonding layer can be made higher than the required bonding strength, and the bonding strength between the substrate based on the bonding layer and the wavelength conversion element can be fully ensured, it can be appropriately changed. For example, the amount of oxygen substance can be greater than 1.0 and less than 1.3. That is, the bonding reinforcement layer 56 may not contain tin dioxide having a rutile crystal structure.

[0238] In the above-mentioned second embodiment, in the molar composition ratio of tin oxide constituting the diffusion suppression layer 59, when the amount of tin substance is set to 1, the amount of oxygen substance is greater than 1.1 and less than 2.0. That is, the diffusion suppression layer 59 contains tin dioxide. The molar composition ratio of tin oxide constituting such a diffusion suppression layer 59 can be appropriately changed as long as the bonding strength between the diffusion suppression layer and the bonding layer can be made higher than the required bonding strength and the bonding strength between the substrate based on the bonding layer and the wavelength conversion element can be fully ensured. For example, the amount of oxygen substance can be greater than 1.0 and less than 1.1. That is, the diffusion suppression layer 59 may not contain tin dioxide having a rutile crystal structure.

[0239] In the above embodiment, the projector 1 includes three light modulators 343R, 343G, and 343B. However, the present invention is not limited to this, and the present disclosure can also be applied to a projector including two or less or four or more light modulators.

[0240] In the above embodiment, if Figure 1 As shown, the image projection device 3 is configured in a substantially L-shape. However, the present invention is not limited thereto, and the image projection device may be configured in a substantially U-shape, for example.

[0241] In the above embodiment, the light modulator 34 has a transmissive liquid crystal panel with different light incident surfaces and light exit surfaces. However, the present invention is not limited thereto, and the light modulator may also have a reflective liquid crystal panel with the same light incident surface and light exit surface. In addition, as long as the light modulator is capable of modulating an incident light beam to form an image corresponding to image information, a light modulator other than liquid crystal, such as a device using a micromirror, for example, a DMD (Digital Micromirror Device) may be used.

[0242] In the above-described embodiment, the light source device 4 is applied to the projector 1. However, the light source device of the present disclosure is not limited thereto, and may be applied to lighting equipment, headlights of automobiles, and the like.

[0243] Summary of the Disclosure

[0244] The following is a summary of the present disclosure.

[0245] Note 1

[0246] A wavelength conversion device, characterized in that the wavelength conversion device comprises: a substrate, which is composed of either copper or a copper alloy; a copper oxide layer, which is formed on the first surface of the substrate; a bonding reinforcement layer, which is a tin oxide layer containing tin oxide and stacked on the copper oxide layer; a bonding layer, which is arranged on the bonding reinforcement layer; and a wavelength conversion element, which is arranged on the bonding layer.

[0247] According to such a configuration, by forming the copper oxide layer on the first surface of the substrate, it is possible to suppress degradation of the substrate made of copper or a copper alloy.

[0248] Furthermore, by laminating the bonding reinforcing layer as a tin oxide layer on the copper oxide layer, the adhesion between the bonding reinforcing layer and the bonding layer can be improved, and the adhesion between the substrate and the bonding layer can be improved.

[0249] Therefore, the bonding strength between the wavelength conversion element and the substrate by the bonding layer can be improved, and a stable wavelength conversion device can be configured.

[0250] Note 2

[0251] The wavelength conversion device according to Supplementary Note 1 is characterized in that the wavelength conversion element has: a reflective layer, which is arranged on the substrate side of the wavelength conversion element; and a phosphor layer, which is stacked on the side of the reflective layer opposite to the substrate.

[0252] According to such a configuration, the wavelength conversion element includes the reflective layer and the phosphor layer, and thus the wavelength conversion device can be configured as a stable reflective type wavelength conversion device.

[0253] Note 3

[0254] The wavelength conversion device according to Supplementary Note 1 or 2 is characterized in that the bonding layer includes a first bonding layer, which is stacked on the bonding reinforcement layer and contains any one of silver, gold, platinum and palladium.

[0255] Here, the tin oxide layer constituting the bonding reinforcement layer has high adhesion to the bonding layer including the first bonding layer, and thus the bonding strength between the wavelength conversion element and the substrate by the bonding layer can be improved. Therefore, a stable wavelength conversion device can be formed.

[0256] Note 4

[0257] The wavelength conversion device according to Note 3 is characterized in that the bonding layer includes: a second bonding layer, which is stacked on the first bonding layer and contains silver nanoparticles; and a third bonding layer, which is stacked on the second bonding layer and contains any one of silver, gold, platinum and palladium.

[0258] According to such a structure, the bonding layer includes the second bonding layer and the third bonding layer in addition to the first bonding layer, thereby improving the bonding strength between the wavelength conversion element and the substrate by the bonding layer. Therefore, a stable wavelength conversion device can be formed.

[0259] Note 5

[0260] The wavelength conversion device according to any one of Supplementary Notes 1 to 4 is characterized in that the thickness of the bonding strengthening layer is greater than 10 nm.

[0261] According to such a structure, the bonding strengthening layer containing tin oxide can be formed as a continuous layer, and the bonding strength with the bonding layer can be improved. Therefore, a stable wavelength conversion device can be configured.

[0262] Note 6

[0263] The wavelength conversion device according to Supplementary Note 5 is characterized in that the thickness of the bonding strengthening layer is greater than 20 nm.

[0264] According to such a structure, the bonding strength between the bonding reinforcing layer and the bonding layer can be further improved, and the wavelength conversion element and the base material can be stably bonded. Therefore, a stable wavelength conversion device can be constructed.

[0265] Note 7

[0266] The wavelength conversion device according to any one of Supplementary Notes 1 to 6 is characterized in that, in the molar composition ratio of tin oxide constituting the bonding strengthening layer, when the amount of tin is 1, the amount of oxygen is 1.3 or more and 2.0 or less.

[0267] According to such a structure, the bonding reinforcement layer contains tin dioxide. Thus, the bonding strength between the bonding reinforcement layer as the tin oxide layer and the bonding layer can be improved, so that the wavelength conversion element and the substrate can be stably bonded. Therefore, a stable wavelength conversion device can be formed.

[0268] Note 8

[0269] A wavelength conversion device, characterized in that it comprises: a substrate having a first surface and being composed of either copper or a copper alloy; a diffusion suppression layer containing tin oxide and arranged on the first surface; a bonding layer arranged on the diffusion suppression layer; and a wavelength conversion element arranged on the bonding layer.

[0270] According to such a structure, in the process of bonding the wavelength conversion element to the substrate through the bonding layer, the diffusion suppression layer containing tin oxide can be used to suppress the diffusion of copper atoms from the substrate to the bonding layer. Thus, it is possible to prevent the bonding force of the bonding layer from being reduced due to the diffusion of copper atoms into the bonding layer. Therefore, the bonding strength between the wavelength conversion element based on the bonding layer and the substrate can be improved, and a stable wavelength conversion device can be formed.

[0271] Note 9

[0272] The wavelength conversion device according to Supplementary Note 8 is characterized in that the wavelength conversion element has: a reflective layer, which is arranged on the substrate side of the wavelength conversion element; and a phosphor layer stacked on the side of the reflective layer opposite to the substrate.

[0273] According to such a configuration, the wavelength conversion element includes the reflective layer and the phosphor layer, and thus the wavelength conversion device can be configured as a stable reflective type wavelength conversion device.

[0274] Note 10

[0275] In the wavelength conversion device described in Supplementary Note 8 or Supplementary Note 9, it is characterized in that, in the molar composition ratio of tin oxide constituting the diffusion suppression layer, when the amount of tin substance is set to 1, the amount of oxygen substance is greater than or equal to 1.1 and less than or equal to 2.0.

[0276] According to such a structure, the diffusion suppression layer contains tin dioxide. The diffusion suppression layer containing tin dioxide can effectively suppress the diffusion of copper atoms, thereby improving the adhesion between the diffusion suppression layer and the bonding layer. Therefore, the wavelength conversion element and the substrate can be stably bonded, and a stable wavelength conversion device can be formed.

[0277] Note 11

[0278] In the wavelength conversion device according to Supplementary Note 8 or Supplementary Note 9, it is characterized in that the tin oxide constituting the diffusion suppression layer contains tin oxide having a rutile crystal structure.

[0279] Tin oxide having a rutile crystal structure is tin dioxide. Therefore, the diffusion suppression layer contains tin dioxide. As described above, the diffusion suppression layer containing tin dioxide can effectively suppress the diffusion of copper atoms, thereby improving the adhesion between the diffusion suppression layer and the bonding layer. Therefore, the wavelength conversion element and the substrate can be stably bonded, and a stable wavelength conversion device can be formed.

[0280] Note 12

[0281] The wavelength conversion device according to Supplementary Note 10 or 11, characterized in that the thickness of the diffusion suppression layer is greater than or equal to 30 nm.

[0282] According to such a structure, diffusion of copper atoms into the bonding layer can be reliably suppressed, so that the bonding strength between the wavelength conversion element and the substrate by the bonding layer can be improved, and a stable wavelength conversion device can be formed.

[0283] Note 13

[0284] In the wavelength conversion device described in any one of Supplementary Notes 8 to 12, it is characterized in that the bonding layer includes a first bonding layer containing any one of silver, gold, platinum and palladium, and is stacked on the diffusion suppression layer.

[0285] According to such a structure, it is possible to suppress the diffusion of copper atoms from the substrate into the first bonding layer stacked on the diffusion suppression layer.

[0286] Furthermore, the tin oxide layer constituting the diffusion suppression layer has high adhesion to the bonding layer including the first bonding layer, so the bonding strength between the wavelength conversion element and the substrate by the bonding layer can be improved. Therefore, a stable wavelength conversion device can be configured.

[0287] Note 14

[0288] In the wavelength conversion device described in Note 13, it is characterized in that the bonding layer includes: a second bonding layer, which is stacked on the first bonding layer and contains silver nanoparticles; and a third bonding layer, which is stacked on the second bonding layer and contains any one of silver, gold, platinum and palladium.

[0289] According to such a structure, the bonding layer includes the second bonding layer and the third bonding layer in addition to the first bonding layer, thereby improving the bonding strength between the wavelength conversion element and the substrate by the bonding layer. Therefore, a stable wavelength conversion device can be formed.

[0290] Note 15

[0291] The wavelength conversion device according to any one of Notes 8 to 14 is characterized in that the substrate has: a base material, which is composed of any one of copper and a copper alloy; and a copper oxide layer formed on the base material, and at least a portion of the first surface is composed of the copper oxide layer.

[0292] According to such a configuration, the adhesion of the diffusion suppression layer to the substrate can be improved by the copper oxide layer, and therefore the bonding strength of the wavelength conversion element to the substrate can be improved.

[0293] Note 16

[0294] A light source device, characterized in that the light source device comprises: a solid light source that emits excitation light; and a wavelength conversion device as described in any one of Notes 1 to 15, which converts the wavelength of the excitation light.

[0295] According to such a configuration, the same effect as that of the above-mentioned wavelength conversion device is achieved. Thus, a light source device capable of emitting light stably can be configured.

[0296] Note 17

[0297] A projector, characterized in that the projector comprises: a light source device as described in Supplement 16; an image light generating device which generates image light based on the light of the light source device; and a projection optical device which projects the generated image light.

[0298] According to such a configuration, the same effects as those of the above-mentioned light source device are achieved. Thus, a projector capable of stably projecting image light can be constructed.

Claims

1. A wavelength conversion device, characterized in that: The wavelength conversion device has: A substrate composed of any one of copper and a copper alloy; A copper oxide layer formed on the first surface of the substrate; a bonding strengthening layer, which is a tin oxide layer containing tin oxide and stacked on the copper oxide layer; a bonding layer, which is disposed on the bonding strengthening layer; as well as The wavelength conversion element is configured on the bonding layer.

2. The wavelength conversion device according to claim 1, characterized in that: The wavelength conversion element has: a reflective layer disposed on the substrate side of the wavelength conversion element; and A phosphor layer is stacked on the side of the reflective layer opposite to the substrate.

3. The wavelength conversion device according to claim 1 or 2, characterized in that: The bonding layer includes a first bonding layer which is stacked on the bonding reinforcement layer and contains any one of silver, gold, platinum and palladium.

4. The wavelength conversion device according to claim 3, characterized in that: The bonding layer comprises: a second bonding layer, which is stacked on the first bonding layer and contains silver nanoparticles; and The third bonding layer is stacked on the second bonding layer and contains any one of silver, gold, platinum and palladium.

5. The wavelength conversion device according to claim 1 or 2, characterized in that: The thickness of the bonding strengthening layer is greater than 10 nm.

6. The wavelength conversion device according to claim 5, characterized in that: The thickness of the bonding strengthening layer is greater than 20 nm.

7. The wavelength conversion device according to claim 1 or 2, characterized in that: In the molar composition ratio of the tin oxide constituting the bonding strengthening layer, when the amount of tin substance is 1, the amount of oxygen substance is 1.3 or more and 2.0 or less.

8. A wavelength conversion device, characterized in that: The wavelength conversion device has: A substrate having a first surface and made of either copper or a copper alloy; a diffusion suppression layer comprising tin oxide and disposed on the first surface; a bonding layer disposed on the diffusion suppression layer; as well as The wavelength conversion element is configured on the bonding layer.

9. The wavelength conversion device according to claim 8, characterized in that: The wavelength conversion element has: a reflective layer disposed on the substrate side of the wavelength conversion element; and A phosphor layer is stacked on the side of the reflective layer opposite to the substrate.

10. The wavelength conversion device according to claim 8 or 9, characterized in that: In the molar composition ratio of tin oxide constituting the diffusion suppression layer, when the amount of substance of tin is 1, the amount of substance of oxygen is 1.1 or more and 2.0 or less.

11. The wavelength conversion device according to claim 10, characterized in that: The diffusion suppression layer has a thickness of 30 nm or more.

12. The wavelength conversion device according to claim 8 or 9, characterized in that: The tin oxide constituting the diffusion suppression layer includes tin oxide having a rutile crystal structure.

13. The wavelength conversion device according to claim 12, characterized in that: The diffusion suppression layer has a thickness of 30 nm or more.

14. The wavelength conversion device according to claim 8 or 9, characterized in that: The bonding layer includes a first bonding layer containing any one of silver, gold, platinum, and palladium and stacked on the diffusion suppression layer.

15. The wavelength conversion device according to claim 14, characterized in that: The bonding layer comprises: a second bonding layer, which is stacked on the first bonding layer and contains silver nanoparticles; and The third bonding layer is stacked on the second bonding layer and contains any one of silver, gold, platinum and palladium.

16. The wavelength conversion device according to claim 8 or 9, characterized in that: The substrate has: a substrate composed of any one of copper and a copper alloy; and a copper oxide layer formed on the substrate, At least a portion of the first surface is composed of the copper oxide layer.

17. A light source device, characterized in that: The light source device has: a solid light source that emits excitation light; and The wavelength conversion device according to any one of claims 1 to 16, which converts the wavelength of the excitation light.

18. A projector, characterized in that: The projector features: The light source device according to claim 17; an image light generating device for generating image light based on the light of the light source device; and A projection optical device projects the generated image light.

Images