Phosphor wheel and light source device equipped therewith, projection type image display device

Abstract

To provide a phosphor wheel, a light source device, and a projection type video display device, capable of facilitating production.SOLUTION: A phosphor wheel (50) includes a substrate (51), an intermediate layer (54) arranged on the substrate (51), and a phosphor layer (52) formed in a circular ring shape on the intermediate layer (54). An edge part of the phosphor layer (52) in a radial direction of the circular ring shape and an edge part of the intermediate layer (54) in a region where the phosphor layer (52) is positioned in the radial direction of the circular ring shape are exposed to an outside. The phosphor layer (52) includes a groove part (55) recessed from a substrate (51) side to an exposed surface (52a) side of the phosphor layer (52). The intermediate layer (54) includes a base part (54b) formed on the substrate (51), and a protrusion (54c) packing the groove part (55) from a base part (54b). A light diffusion particle (54a) is included both in the base part (54b) and in the protrusion (54c).SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a phosphor wheel, a light source device including the same, and a projection-type image display apparatus.

Background Art

[0002] Conventionally, many developments have been made on projection-type image display apparatuses, for example, a three-panel projection-type image display apparatus that performs color separation and synthesis on the three primary colors of R (red) / G (green) / B (blue) for display.

[0003] In the projection-type image display apparatus, for example, blue-region colored light emitted from a light source unit is irradiated onto a phosphor wheel to generate yellow-region colored light, and the generated yellow-region colored light is combined with the blue-region colored light emitted from the light source unit to produce white light. This white light is further separated into three primary colored lights, each colored light is modulated, and the modulated colored lights are combined again to generate image light.

[0004] Projection-type image display apparatuses are being developed for further higher brightness to improve visibility in daytime and enable projection onto larger screens. Accordingly, there is a demand for improving the light conversion efficiency of the phosphor wheel.

[0005] Patent Document 1 proposes a phosphor wheel in which a light-transmissive member and a scattering element held by the light-transmissive member are provided in a groove of a traveling direction changing portion.

Prior Art Literature

Patent Literature

[0006]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0007] However, in the technology described in Patent Document 1, an adhesive layer and a reflective film are laminated between the wavelength conversion layer and the substrate, making the manufacturing of the phosphor wheel complicated.

[0008] The purpose of this disclosure is to provide a phosphor wheel, a light source device, and a projection-type image display device that can be easily manufactured. [Means for solving the problem]

[0009] The phosphor wheel according to this disclosure comprises a substrate, an intermediate layer containing light-diffusing particles and disposed on the substrate, and a phosphor layer formed in an annular shape on the intermediate layer. The phosphor layer has grooves recessed from the substrate side toward the exposed surface side of the phosphor layer, and the grooves extend in a direction intersecting the circumferential direction of the phosphor layer and include a plurality of first grooves formed at intervals in the circumferential direction. The intermediate layer is filled between the phosphor layer and the substrate, including the grooves. The phosphor layer has grooves recessed from the substrate side toward the exposed surface side of the phosphor layer. The intermediate layer has a base formed on the substrate and a convex portion filling the grooves from the base, and the light-diffusing particles are contained in both the base and the convex portion.

[0010] Furthermore, the light source device according to this disclosure comprises the phosphor wheel described above, a light source unit that generates illumination light, and a light guide optical system that guides the illumination light from the light source unit to the phosphor wheel.

[0011] Furthermore, the projection-type image display device according to this disclosure comprises the above-mentioned light source device, an illumination optical system that supplies light to a color separation and synthesis prism, and a projection optical system that projects the synthesized light. [Effects of the Invention]

[0012] This disclosure provides a phosphor wheel, a light source device, and a projection-type image display device that can be easily manufactured. [Brief explanation of the drawing]

[0013] [Figure 1] Schematic diagram showing the overall configuration of the projection-type video display device according to Embodiment 1. [Figure 2] Schematic diagram showing a configuration example of the phosphor wheel of Fig. 1 [Figure 3] Cross-sectional view taken along line III-III in Fig. 2(a) [Figure 4] Cross-sectional view taken along line IV-IV in Fig. 2(a) [Figure 5] Flowchart showing the manufacturing flow of a phosphor wheel [Figure 6A] Cross-sectional view showing a manufacturing step of a phosphor wheel [Figure 6B] Cross-sectional view showing a manufacturing step of a phosphor wheel [Figure 6C] Cross-sectional view showing a manufacturing step of a phosphor wheel [Figure 6D] Cross-sectional view showing a manufacturing step of a phosphor wheel [Figure 7] Front view of a phosphor wheel according to Embodiment 2 [Figure 8] Cross-sectional view taken along line VIII-VIII in Fig. 7 DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments will be described in detail with appropriate reference to the drawings. However, an unnecessarily detailed description may be omitted. For example, detailed descriptions of already well-known matters and repeated descriptions for substantially the same configuration may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art.

[0015] It should be noted that the accompanying drawings and the following description are provided to allow those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter recited in the claims thereby.

[0016] (Embodiment 1) Hereinafter, Embodiment 1 will be described with reference to Figs. 1 to 6D. A projection-type image display device having a DMD as a light modulation element will be described below as a specific example of the projection-type image display device according to the present disclosure.

[0017] [1-1. Configuration] FIG. 1 is a schematic diagram showing the overall configuration of a projection-type image display apparatus 1 according to an embodiment. The projection-type image display apparatus 1 of FIG. 1 includes a light source device 10 that supplies light to a color separation / combination prism 340, the color separation / combination prism 340, and a projection optical system 140 that projects combined light color-combined in the color separation / combination prism 340.

[0018] The light source device 10 includes a plurality of blue semiconductor lasers (hereinafter referred to as "LDs") 201 and 202 serving as a light source unit, a light guiding optical system 20 that guides illumination light 30, which is colored light in a blue region emitted from the blue semiconductor lasers 201 and 202, to a phosphor wheel 50, and the phosphor wheel 50. The light guiding optical system 20 includes a plurality of lens groups 210 and 220, a mirror 203, a dichroic mirror 206, and condenser lenses 104 and 230. The lens group 210 includes a convex lens 211 and a concave lens 212, and is an afocal lens that re-collimates light emitted from the LD 201. The lens group 220 includes convex lenses 221 and 223, and is an afocal lens that re-collimates light emitted from the LD 202. The LDs 201 and 202 emit colored light in the blue region with a wavelength range from 447 nm to 462 nm.

[0019] Light emitted from the LD 201 is shaped into parallel light having a desired beam width when passing through the convex lens 211 and the concave lens 212, and reaches the dichroic mirror 206 after passing through a diffusion plate 204.

[0020] The dichroic mirror 206 has a characteristic of transmitting colored light in the blue region, and reflecting 96% or more of colored light in the green and red regions, for example. The colored light in the blue region from the LD 201 incident on the dichroic mirror 206 passes through the dichroic mirror 206 as it is, and travels toward the condenser lens 230.

[0021] The colored light in the blue region transmitted through the dichroic mirror 206 is incident on the condenser lens 230. While gradually condensing the colored light in the blue region, the condenser lens 230 forms a spot 40 where the illumination light (colored light in the blue region) 30 is condensed on the phosphor wheel 50.

[0022] The phosphor layer 52, excited by spot 40, emits yellow-region color light, including green and red-region color light. The phosphor wheel 50 is made of substrate 51 and rotates around the central axis 50a, thereby suppressing the temperature rise of the phosphor layer 52 due to blue-region color light and stably maintaining fluorescence conversion efficiency. Light incident on the phosphor layer 52 fluoresces green and red-region color light and emits from the phosphor wheel 52. The light emitted towards the substrate 51 is diffusely reflected by the intermediate layer 54 (see Figure 4) and emitted from the phosphor wheel.

[0023] The green and red colored light emitted from the phosphor layer 52 is emitted as natural light with random polarization states, converted back into nearly parallel light by the condenser lens 230, and then incident on the dichroic mirror 206. Since the dichroic mirror 206 has the characteristic of reflecting more than 96% of colored light including green and red components, the light reflected by the dichroic mirror 206 is incident on the condenser lens 104 and focused on the rod integrator 105.

[0024] Meanwhile, the light emitted from LD202 reaches the dichroic mirror 206. The light emitted from LD202 passes directly through the dichroic mirror 206, enters the condenser lens 104, and is focused onto the rod integrator 105.

[0025] In this way, the yellow component color light, including the green and red components, emitted from the phosphor wheel 50, and the blue component color light from the LD202 are combined by the dichroic mirror 206 and focused as white light by the rod integrator 105. These red, green, and blue component color lights exhibit good primary colors, and these color lights can be combined to obtain good white balance emission characteristics. Furthermore, by controlling the ON / OFF state with the DMD106, they can be converted into colors with desired chromaticity coordinates.

[0026] The rod integrator 105 is a solid rod made of a transparent material such as glass. The rod integrator 105 generates light with a uniform light intensity distribution by reflecting the incident light multiple times inside. The rod integrator 105 may also be a hollow rod whose inner wall is made of a mirror surface.

[0027] Lenses 122 and 123 are relay lenses that substantially focus the light emitted from the rod integrator 105 onto the DMD 106. The light emitted from the rod integrator 105 is transmitted through lenses 122 and 123 and reflected by mirror 134 before entering the internal total internal reflection prism (hereinafter referred to as "TIR prism") 130. The TIR prism 130 is composed of a substantially triangular prism shape and totally reflects light that enters the prism at an angle greater than or equal to the critical angle. Light that enters the TIR prism 130 from mirror 134 is totally reflected at this prism surface and enters the color separation and synthesis prism 340 of the light modulation unit 330.

[0028] The light modulation unit 330 includes a color separation and synthesis prism 340 that separates the colors of incident light, and DMD106B, 106R, and 106G as light modulation elements that modulate the separated light.

[0029] The color separation and synthesis prism 340 is composed of three prisms 340B, 340R, and 340G. A blue-range reflective dichroic coating layer 185 is formed on the surface of prism 340B that is close to prism 340R, and a red-range reflective dichroic coating layer 186 is formed on the surface of prism 340R that is close to prism 340G. Prism 340B is a roughly triangular prism-shaped prism, and light incident from the TIR prism 130 passes through prism 340B before reaching the blue-range reflective dichroic coating layer 185.

[0030] The blue-spectrum reflective dichroic coating layer 185 is configured to reflect wavelengths corresponding to the blue component of color light and transmit other light (green component of color light and red component of color light). For example, when the incident angle on the coated surface is 27 degrees, the blue-spectrum reflective dichroic coating layer 185 has the characteristic that the wavelength at which the transmittance of green component color light is 50% is 505 nm.

[0031] On the other hand, the red-band reflective dichroic coating layer 186 is configured to reflect wavelengths corresponding to the red-band component of color light and transmit other light (green-band component of color light and blue-band component of color light). The red-band reflective dichroic coating layer 186 has the characteristic that, for example, at an incident angle of 11 degrees on the coating surface, the wavelength at which the transmittance of green-band component color light is 596 nm is 596 nm. White color light that enters from the TIR prism 130 and reaches prism 340B in the color separation and synthesis prism 340 is incident on the blue-band reflective dichroic coating layer 185 provided inside prism 340B, where the blue-band component of color light is reflected, and then the blue-band component of color light is totally reflected at the surface of prism 340B and then substantially imaged onto the DMD 106B.

[0032] Meanwhile, the green and red colored light passes through the blue-reflecting dichroic coating layer 185 and then enters the prism 340R. The prism 340R is a roughly triangular prism, and the light incident from the prism 340B passes through the prism 340R and then reaches the red-reflecting dichroic coating layer 186. The green and red colored light that reaches it is reflected by the red-reflecting dichroic coating layer 186, and then the red colored light is totally reflected at the surface of the prism 340R through the air gap between the prism 340R and the prism 340B, and then roughly imaged onto the DMD106R.

[0033] The green color light that was not reflected by the red-band dichroic coating layer 186 enters prism 340G. Prism 340R is a roughly rectangular prism and, after passing through prism 340G, is roughly imaged onto DMD106G.

[0034] Based on various control signals such as video signals, the DMD106B, 106R, and 106G are modulated to generate video light of different light intensities. Specifically, the DMD106B, 106R, and 106G have multiple movable micro-mirrors. Each micro-mirror basically corresponds to one pixel. The DMD106B, 106R, and 106G switch whether or not to direct the reflected light towards the projection optical system 140 by changing the angle of each micro-mirror based on various control signals.

[0035] The blue-spectrum light reflected by DMD106B is re-entered by prism 340B, undergoes total internal reflection on the surface of prism 340B, and then re-enters the blue-spectrum dichroic coating layer 185. The light that is mostly reflected by the blue-spectrum dichroic coating layer 185 passes through prism 340B, and the light to be projected as an image (DMD-ON light) is incident on the projection optical system 140 and then emitted onto the projection surface, while the light that is not to be projected as an image (DMD-OFF light) is not incident on the projection optical system 140 but is output from prism 340B.

[0036] The red-spectrum light reflected by DMD106R is re-entered by prism 340R, undergoes total internal reflection on the surface of prism 340R, and then re-enters the red-spectrum dichroic coating layer 186. The light, which is mostly reflected by the red-spectrum dichroic coating layer 186, passes through prism 340R and then re-enters the blue-spectrum dichroic coating layer 185 on prism 340B. The light, which is mostly transmitted by the blue-spectrum dichroic coating layer 185, passes through prism 340B, and the light to be projected as an image (DMD-ON light) is incident on the projection optical system 140 and then emitted onto the projection surface, while the light not to be projected as an image (DMD-OFF light) does not enter the projection optical system 140 but is output from prism 340B.

[0037] The green gamut component of the colored light reflected by DMD106G is re-entered by prism 340G and then re-entered by the red gamut reflective dichroic coating layer 186. The light that is mostly transmitted through the red gamut reflective dichroic coating layer 186 passes through prism 340R and then re-entered by the blue gamut reflective dichroic coating layer 185 on prism 340B. The light that is mostly transmitted through the blue gamut reflective dichroic coating layer 185 passes through prism 340B, and the light to be projected as an image (DMD-ON light) is incident on the projection optical system 140 and then emitted onto the projection surface, while the light that is not to be projected as an image (DMD-OFF light) does not enter the projection optical system 140 but is output from prism 340B.

[0038] The projection optical system 140 is equipped with multiple lenses and magnifies the color-combined light emitted from the color separation and synthesis prism 340. In this way, the DMD-ON light reflected by the DMDs 106B, 106R, and 106G is color-combined again within the color separation and synthesis prism 340, separating the blue, green, and red light, before reaching the projection surface through the projection optical system 140 and being perceived as a full-color image. The image includes both still and moving images.

[0039] [1-2. Phosphor Wheel Configuration] Next, refer to Figures 2-4. Figure 2 shows a diagram of the phosphor wheel 50. Figure 2(a) is a view of the phosphor wheel 50 from the front in the direction of light incidence, and Figure 2(b) is a view of Figure 2(a) from the side. Figure 3 is a cross-sectional view taken along the line III-III in Figure 2(a). Figure 4 is a cross-sectional view taken along the line IV-IV in Figure 2(a). In each figure, the plane on which the phosphor wheel 50 receives illumination light is defined as the XY plane, and the direction perpendicular to the XY plane is defined as the Z direction. The Z direction is also defined as the vertical direction.

[0040] The phosphor wheel 50 is a circular plate that can be rotated relative to a central axis 50a, comprising a substrate 51 and a drive motor 53 in the center. The substrate 51 is made of aluminum, for example, and has a first main surface 51a and a second main surface 51b. The phosphor wheel 50 further comprises an intermediate layer 54 laminated on the substrate 51 and a phosphor layer 52 laminated on the intermediate layer 54. The phosphor layer 52 is laminated on the first main surface 51a of the substrate 51 via the intermediate layer 54. The drive motor 53 is attached to the second main surface 51b of the substrate 51.

[0041] The exposed surface 52a of the phosphor layer 52 is irradiated with blue-region colored light from the condenser lens 230. The phosphor layer 52 is formed using an inorganic substance such as alumina as a binder. The phosphor layer 52 contains multiple phosphor particles 52b. The phosphor particles 52b are, for example, Ce-activated YAG-based yellow phosphors that are excited by the irradiated blue-region colored light and emit yellow-region colored light that includes wavelength components of green-region and red-region colored light. The typical chemical structure of the crystalline matrix of these phosphor particles 52b is Y3Al5O 12 The phosphor layer 52 is formed in an annular shape when viewed from the front in the direction of light incidence on the substrate 51.

[0042] The phosphor layer 52 has a base portion 52c that extends continuously parallel to the substrate 51, a protrusion 52d that projects from the base portion 52c toward the substrate 51, and a groove portion 55 that is recessed between adjacent protrusions 52d toward the exposed surface 52a of the phosphor layer 52 from the substrate 51 side.

[0043] The groove 55 includes a plurality of first grooves 56 formed at intervals in the circumferential direction DB of the phosphor layer 52. The groove 55 also includes second grooves 57 formed at intervals in a direction intersecting the circumferential direction DB of the phosphor layer 52.

[0044] Each of the multiple first grooves 56 extends in a direction intersecting the circumferential direction DB of the phosphor layer 52, for example, in the radial direction (radial direction of the substrate 51) DA of the phosphor layer 52. Similarly, each of the multiple second grooves 57 extends in the circumferential direction DB of the phosphor layer 52 and is formed concentrically around the phosphor layer 52. The common features of the first grooves 56 and the second grooves 57 are described below in the explanation of the groove portion 55.

[0045] No groove 55 is formed in the base 52c of the phosphor layer 52, and the top 59 of the groove 55 does not reach the exposed surface 52a. In other words, the thickness D1 of the phosphor layer 52 is longer than the depth D2 of the groove 55, and the exposed surface 52a of the phosphor layer 52 is located a predetermined distance closer to the illumination light incidence than the top 59 of the groove 55. The thickness of the base 52c is, for example, 10 μm to 100 μm. The base 52c is effective in allowing the phosphor layer 52 to maintain its annular shape and can improve the durability of the phosphor layer 52.

[0046] The protrusions 52d of the phosphor layer 52 have wall portions 58 that extend toward the substrate 51 side as side walls constituting the first groove 56 and the second groove 57. As shown in Figure 3, the wall portions 58 may be inclined portions that are inclined with respect to a direction perpendicular to the first main surface 51a of the substrate 51, or they may extend in a direction perpendicular to the first main surface 51a of the substrate 51. Therefore, the first groove 56 and the second groove 57 may have a wedge shape or a rectangular shape in their longitudinal cross-section. The inclined wall portion 58 of the first groove 56 is also referred to as the first inclined portion, and the inclined wall portion 58 of the second groove 57 is also referred to as the second inclined portion.

[0047] The formation of the wall portion 58 prevents the yellow-region color light generated by the phosphor particles 52b of the phosphor layer 52 from leaking out of the phosphor layer 52 in the radial direction DA, even when the yellow-region color light propagates parallel to the exposed surface 52a, by being reflected by the wall portion 58.

[0048] The intermediate layer 54 has light-diffusing particles 54a that reflect light incident into the intermediate layer 54, a base portion 54b that is continuously formed in an annular shape on the substrate 51, and a protrusion 54c that projects from the base portion 54b toward the exposed surface 52a of the phosphor layer 52. The protrusion 54c of the intermediate layer 54 fills the grooves 55 of the phosphor layer 52.

[0049] The light-diffusing particles 54a are particles with a different refractive index from the binder, which is the main component of the intermediate layer 54. The light-diffusing particles 54a are contained in both the base portion 54b and the convex portion 54c. Therefore, the yellow-region color light traveling from the phosphor layer 52 toward the substrate 51 is reflected toward the exposed surface 52a of the phosphor layer 52 by the light-diffusing particles 54a in the base portion 54b of the intermediate layer 54. This suppresses the absorption of the energy of the yellow-region color light by the substrate 51.

[0050] Furthermore, since the yellow-region color light that has advanced into the grooves 55 of the phosphor layer 52 is reflected by the light-diffusing particles 54a within the protrusions 54c of the intermediate layer 54, leakage of the yellow-region color light from the phosphor layer 52 in the radial direction DA can be further suppressed.

[0051] The spacing Lg1 of each of the multiple first grooves 56 is smaller than the spot 40 of light irradiated onto the phosphor wheel 50. For example, as shown in Figure 2(a), when illumination light 30 of blue-region component color light with an elliptical shape is irradiated onto the phosphor layer 52, the illumination light 30 on the phosphor wheel 50 is irradiated such that the minor axis direction of the ellipse of the spot 40 is the radiation direction DA of the phosphor wheel 50. In this case, the spacing Lg1 of each of the first grooves 56 is smaller than the spot diameter Rs1 in the major axis direction of the ellipse of the spot 40. Therefore, even if the light whose wavelength has been converted in the phosphor layer 52 propagates in the tangential direction of the circumferential direction DB, it is reflected by the walls 58 and light-diffusing particles 54a of the first grooves 56 and comes to have a component that propagates perpendicularly to the substrate 51.

[0052] The spacing Lg2 of each of the multiple second grooves 57 is smaller than the width W of the annular phosphor layer 52 when viewed from the front in the direction of light incidence on the substrate 51. Also, the spacing Lg2 of each of the multiple second grooves 57 is smaller than the spot 40 of the illumination light 30 irradiated onto the phosphor wheel 50. For example, as shown in Figure 2(a), when an elliptical illumination light 30 is irradiated onto the phosphor layer 52, the illumination is performed such that the minor axis direction of the ellipse of the spot 40 is the radiation direction DA of the phosphor wheel 50. In this case, the spacing of each of the second grooves 57 is smaller than the spot diameter Rs2 in the minor axis direction of the ellipse of the spot 40. Therefore, even if the light whose wavelength has been converted in the phosphor layer 52 propagates in the radiation direction DA, 2 groove 57 The light is reflected by the wall portion 58 and the light-diffusing particles 54a and propagates in the Z-axis direction.

[0053] Next, the manufacturing method of the phosphor wheel 50 will be described with reference to Figures 5 and 6A-6D. Figure 5 is a flowchart showing the manufacturing flow of the phosphor wheel 50. Figures 6A-6D are cross-sectional views showing the manufacturing process of the phosphor wheel 50, respectively.

[0054] As shown in Figure 6A, in step S1, a binder 52e such as alumina and phosphor particles 52b are mixed and sintered in a ring shape to form a phosphor layer 52.

[0055] Next, as shown in Figure 6B, in step S2, a portion of the phosphor layer 52 is removed to form a plurality of grooves 55 and a plurality of protrusions 52d.

[0056] Next, as shown in Figure 6C, in step S3, a paste-like filler, such as a silicone resin containing light-diffusing particles 54a, is injected into each groove 55 of the phosphor layer 52, and an intermediate layer 54 is formed by laminating the filler so that a base portion 54b is formed on the phosphor layer 52. The filler is adhesive before it dries.

[0057] Next, as shown in Figure 6D, in step S4, the substrate 51 is bonded to the opposite side of the intermediate layer 54 from where the phosphor layer 52 is bonded, before the intermediate layer 54 dries. After this, the substrate 51 with the phosphor layer 52 laminated on it via the intermediate layer 54 is dried, and the drive motor 53 is attached to the substrate 51 to manufacture the phosphor wheel 50.

[0058] In this way, since the filling of the groove 55 and the formation of the base 54b can be performed in a single step, the manufacturing of the phosphor wheel 50 can be simplified.

[0059] In the manufacturing method described above, the phosphor layer 52 was sintered before the intermediate layer 54 was laminated, but this is not the only method. Alternatively, the intermediate layer 54 may be solidified into an annular shape first, then a portion of the intermediate layer 54 may be scraped to form a protrusion 54c, and a paste-like binder 52e containing phosphor particles 52b may be injected into the intermediate layer 54 in a mold and solidified.

[0060] [1-3. Effects, etc.] As described above, in Embodiment 1, the phosphor wheel 50 comprises a substrate 51, a phosphor layer 52 formed in an annular shape on the substrate 51, and an intermediate layer 54 containing light-diffusing particles 54a and disposed between the substrate 51 and the phosphor layer 52. The phosphor layer 52 has grooves 55 that are recessed from the substrate 51 side toward the exposed surface 52a side of the phosphor layer 52. The grooves 55 extend in a direction intersecting the circumferential direction DB of the phosphor layer 52 and include a plurality of first grooves 56 that are spaced apart in the circumferential direction DB. The intermediate layer 54 is filled between the phosphor layer 52 and the substrate 51, including the grooves 55.

[0061] Grooves 55 are formed in the phosphor layer 52, and the intermediate layer 54 is filled in the grooves 55. Therefore, even if light generated in the phosphor layer 52 travels in the direction of the grooves 55, this light is reflected at the boundary between the phosphor layer 52 and the intermediate layer 54 in the grooves 55. Consequently, the fluorescence spots generated from the phosphor layer 52 are prevented from spreading beyond the grooves 55, and a decrease in the light utilization efficiency of fluorescence can be prevented. In addition, since the multiple first grooves 56 extend in a direction intersecting the circumferential direction DB, the emission of light in the tangential direction DB of the phosphor layer 52 can be suppressed.

[0062] Furthermore, since the intermediate layer 54 contains light-diffusing particles 54a, light that has traveled to the groove 55 is reflected by the light-diffusing particles 54a, suppressing leakage in the tangential direction of the circumferential direction DB of the phosphor layer 52. In this way, a high reflectivity can be achieved without providing a separate reflective layer for the phosphor layer 52, and the efficiency of fluorescence utilization can be improved with a simple configuration. In addition, the manufacturing of the phosphor wheel 50 can be simplified by omitting the reflective layer. Moreover, since the intermediate layer 54 contains light-diffusing particles 54a, the reflectivity of fluorescence can be improved compared to providing a reflective layer on the substrate 51.

[0063] Furthermore, the thickness D1 of the phosphor layer 52 is greater than the depth D2 of the groove 55. The phosphor layer 52 also has a base portion 52c on the exposed surface 52a side where the groove 55 is not formed. Since the thickness D1 of the phosphor layer 52 is greater than the depth D2 of the groove 55, the phosphor layer 52 has a base portion 52c that extends continuously toward the exposed surface 52a side, maintaining the annular shape of the phosphor layer 52 and improving the durability of the phosphor layer 52. For example, if the phosphor layer 52 does not have a base portion 52c, the illumination light 30 will directly irradiate the apex of the protrusion 54c of the intermediate layer 54, and the illumination light 30 irradiated onto the apex of the protrusion 54c will be reflected without wavelength conversion. This will reduce the fluorescence conversion efficiency of the illumination light 30. By covering the apex of the protrusion 54c with the base portion 52c, the reflection of the illumination light 30 without wavelength conversion is suppressed. Furthermore, if the base portion 52c has a thickness of 10 μm or more, the groove portion 55 suppresses the separation of the phosphor layer 52, making it easier to maintain the phosphor layer 52 in an annular shape, and thus facilitating manufacturing and handling.

[0064] Furthermore, the phosphor layer 52 has a wall portion 58 as a first inclined portion that forms at least a part of the first groove 56 and extends inclined so that the first groove 56 expands toward the substrate 51. As a result, even if light generated in the phosphor layer 52 propagates in the direction of the first groove 56, this light is reflected by the inclined wall portion 58, and leakage of the phosphor layer 52 in the tangential direction DB is suppressed.

[0065] Furthermore, the spacing between each of the multiple first grooves 56 is smaller than the length in the direction perpendicular to the radiation direction DA of the spot 40 of the illumination light 30 irradiated onto the phosphor wheel 50. For example, as shown in Figure 2(a), when an elliptical illumination light 30 is irradiated onto the phosphor layer 52, the illumination light 30 is irradiated such that the minor axis direction of the ellipse is the radiation direction DA of the phosphor wheel 50. In this case, the spacing between each of the first grooves 56 is smaller than the spot diameter Rs1 in the major axis direction of the ellipse of the spot 40, which is perpendicular to the radiation direction DA of the phosphor layer 52. Therefore, even if the light whose wavelength has been converted in the phosphor layer 52 propagates in the tangential direction of the circumferential direction DB, it is reflected by the wall portion 58 and light-diffusing particles 54a of the first grooves 56 and propagates in the Z-axis direction.

[0066] Furthermore, the groove 55 extends in the circumferential direction DB and includes a plurality of second grooves 57 that are spaced apart in directions intersecting the circumferential direction DB. Since the plurality of second grooves 57 extend in the circumferential direction DB, it is possible to suppress the emission of light from the phosphor layer 52 in the direction intersecting the circumferential direction DB.

[0067] Furthermore, the phosphor layer 52 has a wall portion 58 that forms at least a part of the second groove 57 and extends toward the substrate 51 side as a second inclined portion. As a result, even if light generated in the phosphor layer 52 propagates in the direction of the second groove 57, this light is reflected by the inclined wall portion 58, and leakage in a direction intersecting the circumferential direction DB of the phosphor layer 52 can be suppressed.

[0068] Furthermore, the spacing between each of the multiple second grooves 57 is smaller than the width W of the phosphor layer 52 when viewed from the front in the direction of light incidence on the substrate 51. Also, the spacing between each of the multiple second grooves 57 is smaller than the length of the radial direction DA of the spot 40 of the illumination light 30 irradiated onto the phosphor wheel 50. For example, as shown in Figure 2(a), the spacing between each of the second grooves 57 is smaller than the spot diameter Rs2 in the minor axis direction of the ellipse of the spot 40. Therefore, even if the light whose wavelength has been converted in the phosphor layer 52 propagates in a direction intersecting the circumferential direction DB, it is reflected by the walls 58 and light-diffusing particles 54a of the second grooves 57 and propagates in the Z-axis direction.

[0069] (Embodiment 2) Next, the phosphor wheel 50A of Embodiment 2 will be described with reference to Figures 7 and 8. Figure 7 is a front view of the phosphor wheel 50A according to Embodiment 2. Figure 8 is a cross-sectional view taken along the line VIII-VIII in Figure 7.

[0070] As shown in Figure 8, Embodiment 2 changes the vertical cross-section of the first groove 56 in Embodiment 1 from, for example, wedge-shaped to trapezoidal. Aside from this point and the points described below, Embodiment 1 and Embodiment 2 have the same configuration and will not be described further.

[0071] In Embodiment 2, the groove 55A formed in the phosphor layer 52A of the phosphor wheel 50A has a first groove 56A with a trapezoidal cross-section. Furthermore, the groove 55A in Embodiment 2 does not have a second groove 57.

[0072] In the phosphor wheel 50A of Embodiment 2, grooves 55A are formed in the phosphor layer 52A, and an intermediate layer 54 is filled in the grooves 55A. Therefore, even if light generated in the phosphor layer 52A travels in the direction of the grooves 55A, this light is reflected at the boundary between the phosphor layer 52A and the intermediate layer 54A in the grooves 55A. Consequently, the fluorescent spots generated from the phosphor layer 52A are prevented from spreading beyond the grooves 55A, thus preventing a decrease in the light utilization efficiency of the fluorescence. Furthermore, since the multiple first grooves 56A extend in a direction intersecting the circumferential direction DB, the emission of light in the tangential direction DB of the phosphor layer 52A can be suppressed. In addition, by omitting the reflective layer, the manufacturing of the phosphor wheel 50A can be simplified, and the improvement in fluorescence utilization efficiency can be achieved with a simple configuration.

[0073] As described above, the above embodiments have been explained as examples of the technology disclosed in this application. However, the technology in this disclosure is not limited to these embodiments and can be applied to embodiments that have been modified, replaced, added, or omitted. Furthermore, it is possible to create new embodiments by combining the components described in the above embodiments.

[0074] As described above, embodiments have been explained as examples of the technology in this disclosure. For this purpose, attached drawings and a detailed description have been provided. Therefore, among the components described in the attached drawings and detailed description, there may be not only components that are essential for solving the problem, but also components that are not essential for solving the problem, in order to illustrate the above technology. Therefore, the mere fact that these non-essential components are described in the attached drawings and detailed description should not be immediately assumed to mean that these non-essential components are essential.

[0075] Furthermore, since the embodiments described above are for illustrative purposes of the technology described herein, various modifications, substitutions, additions, omissions, etc., can be made within the claims or their equivalents.

[0076] (Summary of the embodiment) (1) The phosphor wheel of the present disclosure comprises a substrate, a phosphor layer formed in an annular shape on the substrate, and an intermediate layer containing light-diffusing particles 54a and disposed between the substrate and the phosphor layer, wherein the phosphor layer has grooves recessed from the substrate side toward the exposed surface side of the phosphor layer, the grooves extend in a direction intersecting the circumferential direction of the phosphor layer and include a plurality of first grooves formed at intervals in the circumferential direction, and the intermediate layer is filled between the phosphor layer and the substrate, including the grooves.

[0077] This allows for the formation of an intermediate layer containing light-diffusing particles between the phosphor layer and the substrate, thus eliminating the need to form a reflective film on the substrate and providing a phosphor wheel that is easy to manufacture.

[0078] (2) In the phosphor wheel of (1), the thickness of the phosphor layer is greater than the depth of the groove.

[0079] (3) In the phosphor wheel of (1) or (2), the phosphor layer has an inclined portion that forms at least a part of the first groove and extends such that the first groove widens toward the substrate side.

[0080] In the phosphor wheel of (4)(3), the first groove has a wedge shape in its longitudinal cross-section.

[0081] In the phosphor wheel of (5)(3), the first groove is trapezoidal in shape.

[0082] (6) In any one of the phosphor wheels described in (1) to (5), the spacing between each of the multiple first grooves is smaller than the length in the direction perpendicular to the radiation direction of the phosphor layer at the spot of light irradiated onto the phosphor wheel.

[0083] (7) In any one of the phosphor wheels from (1) to (6), the groove portion includes a plurality of second grooves that extend in the circumferential direction and are spaced apart in directions intersecting the circumferential direction.

[0084] In the phosphor wheel of (8)(7), the phosphor layer has a second inclined portion that forms at least a part of the second groove and widens toward the substrate side.

[0085] In the phosphor wheel of (9)(8), the second groove has a wedge shape in its longitudinal cross-section.

[0086] In the phosphor wheel of (10)(8), the second groove has a trapezoidal shape in its longitudinal cross-section.

[0087] In the phosphor wheels of (11)(7) to (10), the spacing between each of the multiple second grooves is smaller than the radial length of the phosphor layer at the spot of light irradiated onto the phosphor wheel.

[0088] (12) In the phosphor wheels of (1) to (11), the light-diffusing particles are particles with a different refractive index from the intermediate layer.

[0089] (13) A light source device comprising one phosphor wheel from (1) to (12), a light source unit that generates illumination light, and a light guide optical system that guides the illumination light from the light source unit to the phosphor wheel.

[0090] This allows for the provision of a light source device that is easy to manufacture, as it incorporates a phosphor wheel that eliminates the need to form a reflective film on the substrate.

[0091] A projection-type image display device comprising a light source device as described in (14)(13), a light modulation unit that generates image light using light emitted from the light source device, and a projection optical system that projects the image light.

[0092] This allows for the provision of a projection-type image display device that is easy to manufacture because it incorporates a phosphor wheel that eliminates the need to form a reflective film on the substrate. [Industrial applicability]

[0093] This disclosure is applicable to a phosphor wheel that irradiates illumination light to convert the wavelength of the light, a light source device that uses the wavelength-converted light from the phosphor wheel, and a projection-type image display device. [Explanation of symbols]

[0094] 1. Projection-type image display device 10 Light source device 20 Light guide optical system 30 Illumination Light 40 spots 50 Phosphor Wheels 50a center axis 51 circuit boards 51a 1st principal surface 51b Second main surface 52, 52A Phosphor layer 52a Exposed surface 52b Phosphorescent particles 52c base 52d convex part 52e Binder 53 Drive motor 54 Middle Class 54a Light-diffusing particles 54b base 54c protrusion 55 Groove 56 First groove 57 Second groove 58 Wall 59 Top 104 Condenser Lens 105 Rod Integrator 106, 106B, 106G, 106R DMD 122, 123 lenses 130 TIR prism 134, 203 Miller 140 projection optics 185, 186 Dichroic coat layer 201, 202 Blue semiconductor lasers 204, 205 Diffuser 206 Dichroic Mirror 210, 220 lens group 211, 221 convex lenses 212 Concave lens 230 Condenser Lens 330 Optical Modulation Section 340-color separation and synthesis prism 340B, 340G, 340R prism D1 Thickness D2 Depth DA radiation direction DB circumferential direction Lg1, Lg2 interval Rs1, Rs2 Spot diameter W width

Claims

1. circuit board and An intermediate layer containing light-diffusing particles and placed on the substrate, The intermediate layer comprises a phosphor layer formed in an annular shape, The ends of the phosphor layer in the radial direction of the annular shape and the ends of the intermediate layer in the region where the phosphor layer is located in the radial direction of the annular shape are exposed to the outside. The phosphor layer has grooves that are recessed from the substrate side toward the exposed surface side of the phosphor layer, The aforementioned intermediate layer is A base formed on the substrate, It has a protrusion that fills the groove from the base, The light-diffusing particles are included in both the base and the protrusion. The groove portion is A plurality of first grooves are formed, each spaced apart in the circumferential direction, extending in a direction intersecting the circumferential direction of the phosphor layer, It includes a plurality of second grooves that extend in the circumferential direction and are formed at intervals in a direction intersecting the circumferential direction, The phosphor layer is irradiated with illumination light having a shape with a short axis direction and a long axis direction. The light spot having a shape with a short axis direction and a long axis direction is arranged such that the short axis direction is the radiation direction of the phosphor layer. The spacing between each of the plurality of first grooves is smaller than the length in the direction perpendicular to the radiation direction of the phosphor layer in the light spot. The spacing between each of the plurality of second grooves is smaller than the length of the phosphor layer in the light spot in the radial direction. Phosphor wheel.

2. The thickness of the phosphor layer is longer than the depth of the groove. The phosphor wheel according to claim 1.

3. The phosphor layer has a first inclined portion that forms at least a part of the first groove and extends so that the first groove widens toward the substrate side. The phosphor wheel according to claim 1 or 2.

4. The first groove has a wedge shape in its longitudinal cross-section. The phosphor wheel according to claim 3.

5. The first groove has a trapezoidal shape in its longitudinal cross-section. The phosphor wheel according to claim 3.

6. The spacing between each of the plurality of first grooves is smaller than the length in the direction perpendicular to the radiation direction of the phosphor layer at the spot of light irradiated onto the phosphor wheel. A phosphor wheel according to any one of claims 1 to 5.

7. The phosphor layer forms at least a portion of the second groove and has a second inclined portion that widens toward the substrate side. The phosphor wheel according to claim 1.

8. The second groove has a wedge shape in its longitudinal cross-section. The phosphor wheel according to claim 7.

9. The second groove has a trapezoidal shape in its longitudinal cross-section. The phosphor wheel according to claim 7.

10. The spacing between each of the plurality of second grooves is smaller than the length of the phosphor layer in the radial direction at the spot of light irradiated onto the phosphor wheel. A phosphor wheel according to any one of claims 7 to 9.

11. The light-diffusing particles are particles with a different refractive index from the intermediate layer. A phosphor wheel according to any one of claims 1 to 10.

12. A phosphor wheel according to any one of claims 1 to 11, A light source unit that generates illumination light, A light guide optical system that guides illumination light from the light source to the phosphor wheel, A light source device equipped with the following features.

13. The light source device according to claim 12, A light modulation unit that generates image light using the light emitted from the light source device, The system comprises a projection optical system for projecting the aforementioned image light, Projection-type image display device.

14. circuit board and An intermediate layer containing light-diffusing particles and placed on the substrate, The intermediate layer comprises a phosphor layer formed in an annular shape, The aforementioned intermediate layer has grooves and a cross-section that is substantially concave. The groove portion is filled with the phosphor layer, The ends of the phosphor layer in the radial direction of the annular shape, and the ends of the intermediate layer in the region where the phosphor layer is located in the radial direction of the annular shape, are exposed to the outside. The aforementioned intermediate layer is A base formed on the substrate, It has a protrusion that extends from the base toward the phosphor layer, The light-diffusing particles are included in both the base and the protrusion. The groove portion is A plurality of first grooves are formed, each spaced apart in the circumferential direction, extending in a direction intersecting the circumferential direction of the phosphor layer, It includes a plurality of second grooves that extend in the circumferential direction and are formed at intervals in a direction intersecting the circumferential direction, The phosphor layer is irradiated with illumination light having a shape with a short axis direction and a long axis direction. The light spot having a shape with a short axis direction and a long axis direction is arranged such that the short axis direction is the radiation direction of the phosphor layer. The spacing between each of the plurality of first grooves is smaller than the length in the direction perpendicular to the radiation direction of the phosphor layer in the light spot. The spacing between each of the plurality of second grooves is smaller than the length of the phosphor layer in the light spot in the radial direction. Phosphor wheel.

15. The phosphor layer has a second base that extends continuously toward the exposed surface side of the phosphor layer, The top of the convex portion is covered by the second base portion. The phosphor wheel according to claim 1 or 14.

16. The second base extends parallel to the substrate, The phosphor wheel according to claim 15.

Images