Phosphor wheel, light source device equipped with the same, and projection type video 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 device. [Background technology]

[0002] Conventionally, many projection-type image display devices have been developed, for example, three-panel projection-type image display devices that separate and combine the three primary colors of R (red), G (green), and B (blue) to display images.

[0003] For example, a projection-type image display device generates white light by irradiating a phosphor wheel with blue gamut light emitted from a light source unit, and then synthesizing the generated yellow gamut light with the blue gamut light emitted from the light source unit. This white light is then further separated into three primary colors of light, modulated separately, and the modulated color lights are recombined to generate image light.

[0004] Projection display devices are being developed to achieve even higher brightness in order to improve visibility during the day and to project onto larger screens, which requires improvements in the light conversion efficiency of the phosphor wheel.

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

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2019-174599 Summary of the Invention [Problem to be solved by the invention]

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

[0008] An object of the present 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] A phosphor wheel according to the present disclosure includes a substrate, an intermediate layer disposed on the substrate and containing light-diffusing particles, and a phosphor layer formed in a ring shape on the intermediate layer. The phosphor layer has grooves recessed from the substrate toward the exposed surface of the phosphor layer, and the grooves include a plurality of first grooves extending in a direction intersecting the circumferential direction of the phosphor layer and spaced apart in the circumferential direction. The intermediate layer is filled between the phosphor layer, including the grooves, and the substrate. The phosphor layer has grooves recessed from the substrate toward the exposed surface of the phosphor layer. The intermediate layer has a base formed on the substrate and protrusions that fill the grooves from the base, and the light-diffusing particles are contained in both the base and the protrusions.

[0010] A light source device according to the present disclosure includes the above-described phosphor wheel, a light source unit that generates illumination light, and a light-guiding optical system that guides the illumination light from the light source unit to the phosphor wheel.

[0011] A projection-type image display device according to the present disclosure includes the above-described light source device, an illumination optical system that supplies light to the color separation / combining prism, and a projection optical system that projects the combined light. [Effects of the Invention]

[0012] The present disclosure can provide a phosphor wheel, a light source device, and a projection-type image display device that can be easily manufactured. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic diagram showing the overall configuration of a projection-type image display device according to a first embodiment; [Figure 2] Schematic diagram showing an example of the configuration of the phosphor wheel in Figure 1 [Figure 3] Cross-sectional view of the arrows III-III in Figure 2(a) [Figure 4] Cross-sectional view of arrows IV-IV in Figure 2(a) [Figure 5] Flowchart showing the manufacturing process of phosphor wheels [Figure 6A] Cross-sectional view showing the manufacturing process of the phosphor wheel [Figure 6B] Cross-sectional view showing the manufacturing process of the phosphor wheel [Figure 6C] Cross-sectional view showing the manufacturing process of the phosphor wheel [Figure 6D] Cross-sectional view showing the manufacturing process of the phosphor wheel [Figure 7] FIG. 10 is a front view of a phosphor wheel according to a second embodiment. [Figure 8] Cross-sectional view taken along the arrows VIII-VIII in Figure 7 DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, more detailed explanation than necessary may be omitted. For example, detailed explanation of well-known matters or redundant explanation of substantially the same configuration may be omitted. This is to avoid unnecessary redundancy in the following explanation and to facilitate understanding by those skilled in the art.

[0015] The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0016] (Embodiment 1) 1 to 6D, a first embodiment will be described below. As a specific example of a projection display device according to the present disclosure, a projection display device having a DMD as a light modulation element will be described below.

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

[0018] The light source device 10 includes a plurality of blue semiconductor lasers (hereinafter referred to as "LDs") 201 and 202 as light source units, a light-guiding optical system 20 that guides illumination light 30, which is color light of blue range components 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 the light emitted from the LD 201. The lens group 220 includes convex lenses 221 and 223 and is an afocal lens that re-collimates the light emitted from the LD 202. The LDs 201 and 202 emit color light of blue range components in a wavelength range from 447 nm to 462 nm.

[0019] When the light emitted from the LD 201 passes through the convex lens 211 and the concave lens 212, it is shaped into parallel light with a desired beam width, and then passes through the diffusion plate 204 and reaches the dichroic mirror 206.

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

[0021] The color light of the blue range component transmitted through dichroic mirror 206 is incident on condenser lens 230. Condenser lens 230 gradually collects the color light of the blue range component, and forms spot 40 on phosphor wheel 50 where illumination light (color light of the blue range component) 30 is collected.

[0022] The phosphor layer 52 excited by the spot 40 emits color light of a yellow range component that includes color light of green and red range components. The phosphor wheel 50 is made up of a substrate 51, and by rotating it about a central axis 50a, it is possible to suppress a temperature rise in the phosphor layer 52 due to color light of a blue range component and to maintain stable fluorescence conversion efficiency. Light incident on the phosphor layer 52 fluoresces and emits color light of green and red range components, which then exits the phosphor wheel 50. Furthermore, light emitted toward the substrate 51 is diffused and reflected by an intermediate layer 54 (see FIG. 4) and exits the phosphor wheel.

[0023] The color light of green and red region components emitted from phosphor layer 52 is emitted as natural light with a random polarization state, and is converted again into approximately parallel light by condenser lens 230, and then enters dichroic mirror 206. Since dichroic mirror 206 has the property of reflecting 96% or more of color light containing green and red region components, the light reflected by dichroic mirror 206 enters condenser lens 104 and is collected on rod integrator 105.

[0024] On the other hand, the light emitted from the LD 202 reaches the dichroic mirror 206. The light emitted from the LD 202 passes through the dichroic mirror 206 as it is, enters the condenser lens 104, and is collected on the rod integrator 105.

[0025] In this way, the yellow gamut light containing green and red gamut components emitted from phosphor wheel 50 and the blue gamut light from LD 202 are combined by dichroic mirror 206 and focused as white light on rod integrator 105. These red, green, and blue gamut light components exhibit good three primary colors, and by color combining these color lights, it is possible to obtain light emission characteristics with good white balance, and by performing ON / OFF control with DMD 106, it is possible to convert them into colors with desired chromaticity coordinates.

[0026] Rod integrator 105 is a solid rod made of a transparent material such as glass. Rod integrator 105 generates light with a uniform light intensity distribution by internally reflecting incident light multiple times. Note that 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 approximately image the light emitted from rod integrator 105 onto DMD 106. The light emitted from rod integrator 105 passes through lenses 122 and 123, is reflected by mirror 134, and then enters total internal reflection prism (hereinafter referred to as "TIR prism") 130. TIR prism 130 is formed of a prism having a substantially triangular prism shape, and totally reflects light that enters the prism at an angle equal to or greater than the critical angle. The light that enters TIR prism 130 from mirror 134 is totally reflected by this prism surface and enters color separation / combining prism 340 of light modulation section 330.

[0028] The light modulation section 330 includes a color separation / combination prism 340 that separates the colors of incident light, and DMDs 106B, 106R, and 106G that serve as light modulation elements that modulate the separated light.

[0029] Color separation / combining prism 340 is composed of three prisms 340B, 340R, and 340G, with a blue-reflecting dichroic coating layer 185 formed on the surface of prism 340B adjacent to prism 340R, and a reflective dichroic coating layer 186 that reflects color light of the red range component formed on the surface of prism 340R adjacent to prism 340G. Prism 340B is a substantially triangular prism, and light incident from TIR prism 130 passes through prism 340B and then reaches blue-reflecting dichroic coating layer 185.

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

[0031] On the other hand, the red-reflecting dichroic coating layer 186 is configured to reflect wavelengths corresponding to red-range color light and transmit other light (green-range color light and blue-range color light). The red-reflecting dichroic coating layer 186 has a characteristic that, for example, when the angle of incidence on the coated surface is 11 degrees, the wavelength of green-range color light at which the transmittance is 50% is 596 nm. White color light incident from the TIR prism 130 and reaches the inside of prism 340B in the color separation / combining prism 340 is incident on the blue-reflecting dichroic coating layer 185 provided inside prism 340B, and the blue-range color light is reflected. After that, the blue-range color light is totally reflected on the surface of prism 340B and forms an approximate image on the DMD 106B.

[0032] On the other hand, the green and red color light components are incident on prism 340R after passing through blue-reflecting dichroic coating layer 185. Prism 340R is a prism having a substantially triangular prism shape, and the light incident from prism 340B passes through prism 340R and then reaches red-reflecting dichroic coating layer 186. Of the green and red color light components that have reached this point, the red color light component is reflected by red-reflecting dichroic coating layer 186, and the red color light component is then totally reflected by the surface of prism 340R due to the gap provided between prism 340R and prism 340B, before being approximately imaged on DMD 106R.

[0033] The green light component that is not reflected by the red reflecting dichroic coating layer 186 is incident on the prism 340G. The prism 340R is a substantially quadrangular prism, and after passing through the prism 340G, it forms a substantial image on the DMD 106G.

[0034] The DMDs 106B, 106R, and 106G are modulated based on various control signals such as video signals to generate image light of different light intensities. Specifically, the DMDs 106B, 106R, and 106G have multiple movable micromirrors. Each micromirror basically corresponds to one pixel. The DMDs 106B, 106R, and 106G change the angle of each micromirror based on various control signals, thereby switching whether or not to direct the reflected light toward the projection optical system 140.

[0035] The color light of the blue range component reflected by DMD 106B re-enters prism 340B, is totally reflected on the surface of prism 340B, and then re-enters blue range reflecting dichroic coating layer 185. After most of the light reflected by blue range reflecting dichroic coating layer 185 passes through prism 340B, the light to be projected as an image (DMD-ON light) enters projection optical system 140 and is then emitted to the projection surface, while the light not to be projected as an image (DMD-OFF light) does not enter projection optical system 140 and is output from prism 340B.

[0036] The color light of the red range component reflected by DMD 106R re-enters prism 340R, is totally reflected on the surface of prism 340R, and then re-enters red range reflecting dichroic coating layer 186. The light that is mostly reflected by red range reflecting dichroic coating layer 186 passes through prism 340R and then re-enters blue range reflecting dichroic coating layer 185 provided on prism 340B. The light that is mostly transmitted by blue range reflecting dichroic coating layer 185 passes through prism 340B, and then light to be projected as an image (DMD-ON light) enters projection optical system 140 and is emitted to the projection surface, while light that is not projected as an image (DMD-OFF light) does not enter projection optical system 140 and is output from prism 340B.

[0037] The green range component color light reflected by DMD 106G re-enters prism 340G and then re-enters red range reflecting dichroic coating layer 186. The light that is mostly transmitted by red range reflecting dichroic coating layer 186 passes through prism 340R and then re-enters blue range reflecting dichroic coating layer 185 provided on prism 340B. The light that is mostly transmitted by blue range reflecting dichroic coating layer 185 passes through prism 340B, and then light to be projected as an image (DMD-ON light) enters projection optical system 140 and is emitted to the projection surface, while light that is not projected as an image (DMD-OFF light) does not enter projection optical system 140 and is output from prism 340B.

[0038] Projection optical system 140 includes multiple lenses and magnifies the color-combined light emitted from color separation / combination prism 340. In this way, the DMD-ON light reflected by DMDs 106B, 106R, and 106G is color-combined again into blue, green, and red color lights within color separation / combination prism 340, and then reaches the projection surface through projection optical system 140 and is perceived as a full-color image. Note that the image includes both still images and moving images.

[0039] [1-2. Phosphor wheel configuration] Next, reference is made to Figures 2 to 4. Figure 2 shows a configuration diagram of the phosphor wheel 50. Figure 2(a) is a diagram of the phosphor wheel 50 as seen from the front in the light incident direction, and Figure 2(b) is a side view of Figure 2(a). Figure 3 is a cross-sectional view taken along the arrows III-III in Figure 2(a). Figure 4 is a cross-sectional view taken along the arrows 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 includes a substrate 51 and a drive motor 53 in its center, and is rotatable about a central axis 50a. The substrate 51 is made of, for example, aluminum, and has a first main surface 51a and a second main surface 51b. The phosphor wheel 50 further includes 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 with the intermediate layer 54 interposed between them. 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-range color light from the condenser lens 230. The phosphor layer 52 is formed using, for example, an inorganic substance such as alumina as a binder. The phosphor layer 52 contains a plurality of phosphor particles 52b inside. The phosphor particles 52b are, for example, Ce-activated YAG yellow phosphors that are excited by the irradiated blue-range color light and emit yellow-range color light containing wavelength components of green and red range color light. A typical chemical structure of the crystalline matrix of these phosphor particles 52b is Y3Al5O 12 The phosphor layer 52 is formed in a circular ring shape when viewed from the front of the substrate 51 in the light incident direction.

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

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

[0044] The plurality of first grooves 56 each extend in a direction intersecting the circumferential direction DB of the phosphor layer 52, for example, in the radial direction DA of the phosphor layer 52 (the radial direction of the substrate 51). The plurality of second grooves 57 each extend in the circumferential direction DB of the phosphor layer 52 and are formed concentrically with the phosphor layer 52. Note that the configuration common to the first grooves 56 and the second grooves 57 will be described below in the explanation of the groove portion 55.

[0045] No grooves 55 are formed in base 52c of phosphor layer 52, and tops 59 of grooves 55 do not reach exposed surface 52a. In other words, thickness D1 of phosphor layer 52 is greater than depth D2 of grooves 55, and exposed surface 52a of phosphor layer 52 is located a predetermined distance closer to the illumination light incident side than tops 59 of grooves 55. Base 52c has a thickness of, for example, 10 μm to 100 μm. Base 52c is effective in maintaining the annular shape of phosphor layer 52 and can improve the durability of phosphor layer 52.

[0046] The protrusions 52d of the phosphor layer 52 have wall portions 58 extending toward the substrate 51 as side walls that define the first grooves 56 and the second grooves 57. 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, as shown in FIG. 3 , or may extend in a direction perpendicular to the first main surface 51a of the substrate 51. Therefore, the first grooves 56 and the second grooves 57 may have a wedge-shaped or rectangular cross section. The inclined wall portions 58 of the first grooves 56 are also referred to as first inclined portions, and the inclined wall portions 58 of the second grooves 57 are also referred to as second inclined portions.

[0047] By forming the wall portion 58, even if the color light of the yellow gamut component generated by the phosphor particles 52b of the phosphor layer 52 travels parallel to the exposed surface 52a, the color light of the yellow gamut component can be prevented from being reflected by the wall portion 58 and leaking from the phosphor layer 52 in the radiation direction DA.

[0048] The intermediate layer 54 has light diffusing particles 54a that reflect light that has entered the intermediate layer 54, a base 54b that is continuously formed in a circular ring shape on the substrate 51, and protrusions 54c that protrude from the base 54b toward the exposed surface 52a of the phosphor layer 52. The protrusions 54c of the intermediate layer 54 fill the grooves 55 of the phosphor layer 52.

[0049] The light-diffusing particles 54a are particles with a refractive index different from that of 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 protrusions 54c. Therefore, color light of the yellow gamut component traveling from the phosphor layer 52 toward the substrate 51 is reflected by the light-diffusing particles 54a in the base portion 54b of the intermediate layer 54 toward the exposed surface 52a of the phosphor layer 52. This makes it possible to prevent the energy of the color light of the yellow gamut component from being absorbed by the substrate 51.

[0050] In addition, the color light of the yellow gamut component that travels into the groove portion 55 of the phosphor layer 52 is also reflected by the light diffusing particles 54a in the convex portion 54c of the intermediate layer 54, thereby further suppressing the leakage of the color light of the yellow gamut component from the phosphor layer 52 in the radiation direction DA.

[0051] The spacing Lg1 between the plurality of first grooves 56 is smaller than the spot 40 of light irradiated onto the phosphor wheel 50. For example, as shown in FIG. 2( a), when elliptical illumination light 30 of color light of the blue gamut component is irradiated onto the phosphor layer 52, the illumination light 30 is irradiated such that the minor axis direction of the ellipse of the spot 40 of the illumination light 30 on the phosphor wheel 50 is aligned with the radiation direction DA of the phosphor wheel 50. In this case, the spacing Lg1 between the first grooves 56 is smaller than the spot diameter Rs1 of the ellipse of the spot 40. Therefore, even if the light whose wavelength has been converted by the phosphor layer 52 travels in a tangential direction to the circumferential direction DB, it is reflected by the wall portions 58 of the first grooves 56 and the light diffusing particles 54 a, and has a component traveling in the perpendicular direction to the substrate 51.

[0052] The spacing Lg2 between the plurality of second grooves 57 is smaller than the width W of the annular phosphor layer 52 when viewed from the front of the substrate 51 in the light incident direction. Furthermore, the spacing Lg2 between the plurality of 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 FIG. 2( a), when elliptical illumination light 30 is irradiated onto the phosphor layer 52, the spot 40 is irradiated such that the minor axis direction of the ellipse of the ellipse of the spot 40 is aligned with the radiation direction DA of the phosphor wheel 50. In this case, the spacing between the plurality of second grooves 57 is smaller than the spot diameter Rs2 of the spot 40 in the minor axis direction of the ellipse. Therefore, even if the light wavelength-converted by the phosphor layer 52 travels in the radiation direction DA, it is reflected by the wall portions 58 of the first grooves 56 and the light diffusing particles 54a and travels in the Z-axis direction.

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

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

[0055] Next, as shown in FIG. 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] 6C, in step S3, a paste-like filler such as silicone resin containing light-diffusing particles 54a is poured into each groove 55 of phosphor layer 52, and the filler is further layered on phosphor layer 52 so as to form base 54b, thereby forming intermediate layer 54. The filler has adhesive properties before it dries.

[0057] 6D, in step S4, before the intermediate layer 54 dries, the substrate 51 is adhered to the side of the intermediate layer 54 opposite to the side to which the phosphor layer 52 is adhered. Thereafter, the substrate 51 on which the phosphor layer 52 is laminated via the intermediate layer 54 is dried, and the drive motor 53 is attached to the substrate 51, thereby manufacturing the phosphor wheel 50.

[0058] In this way, the filling of the grooves 55 and the formation of the bases 54b can be carried out at the same time, which simplifies the manufacture of the phosphor wheel 50.

[0059] In the above-described manufacturing method, the intermediate layer 54 is laminated after sintering the phosphor layer 52, but this is not limiting. After the intermediate layer 54 is hardened into a ring shape, a portion of the intermediate layer 54 may be scraped off to form the protrusions 54c, and a paste-like binder 52e containing phosphor particles 52b may be poured into the intermediate layer 54 placed in a mold and hardened.

[0060] [1-3. Effects, etc.] As described above, in the first embodiment, the phosphor wheel 50 includes the substrate 51, the phosphor layer 52 formed in a circular ring shape on the substrate 51, and the 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 recessed from the substrate 51 toward the exposed surface 52a 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 formed at intervals 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 grooves 55 are filled with the intermediate layer 54. Therefore, even if light generated in the phosphor layer 52 travels in the direction of the grooves 55, the light is reflected at the boundary between the phosphor layer 52 and the intermediate layer 54 in the grooves 55. Therefore, the fluorescent spot generated from the phosphor layer 52 is prevented from spreading beyond the grooves 55, and a decrease in the light utilization efficiency of the fluorescent light can be prevented. Furthermore, since the plurality of first grooves 56 extend in a direction intersecting the circumferential direction DB, it is possible to prevent light from being emitted in a tangential direction of the circumferential direction DB of the phosphor layer 52.

[0062] Furthermore, because the intermediate layer 54 contains light diffusing particles 54a, light traveling into the grooves 55 is reflected by the light diffusing particles 54a, preventing leakage in the tangential direction of the circumferential direction DB of the phosphor layer 52. In this way, high reflectivity can be achieved without providing a separate reflective layer for the phosphor layer 52, and improved fluorescent light utilization efficiency can be achieved with a simple configuration. Furthermore, omitting the reflective layer simplifies the manufacture of the phosphor wheel 50. Furthermore, because the intermediate layer 54 contains light diffusing particles 54a, the fluorescent light reflectivity can be improved more than if a reflective layer were provided on the substrate 51.

[0063] The thickness D1 of the phosphor layer 52 is greater than the depth D2 of the grooves 55. The phosphor layer 52 has a base 52c on the exposed surface 52a side where no grooves 55 are formed. Because the thickness D1 of the phosphor layer 52 is greater than the depth D2 of the grooves 55, the phosphor layer 52 has a base 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 did not have a base 52c, the illumination light 30 would directly strike the apexes of the convex portions 54c of the intermediate layer 54, and the illumination light 30 striking the apexes of the convex portions 54c would be reflected without being wavelength-converted. This would reduce the fluorescence conversion efficiency of the illumination light 30. Covering the apexes of the convex portions 54c with the base 52c prevents the illumination light 30 from being reflected without being wavelength-converted. Furthermore, when the base 52c has a thickness of 10 μm or more, the groove 55 prevents the phosphor layer 52 from separating, making it easier to maintain the annular shape of the phosphor layer 52 and facilitating manufacturing and handling.

[0064] Furthermore, the phosphor layer 52 has wall portions 58 that form at least a part of the first grooves 56 and that serve as first inclined portions that extend at an incline so that the first grooves 56 widen toward the substrate 51. As a result, even if light generated in the phosphor layer 52 travels in the direction of the first grooves 56, the light is reflected by the wall portions 58 that extend at an incline, and leakage of the light in the tangential direction of the circumferential direction DB of the phosphor layer 52 can be suppressed.

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

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

[0067] Furthermore, phosphor layer 52 has wall portions 58 that form at least a part of second grooves 57 and serve as second inclined portions that widen toward substrate 51. As a result, even if light generated in phosphor layer 52 travels in the direction of second grooves 57, this light is reflected by wall portions 58 that extend at an incline, and leakage of the light in a direction intersecting with circumferential direction DB of phosphor layer 52 can be suppressed.

[0068] Furthermore, the spacing between the plurality of second grooves 57 is smaller than the width W of the phosphor layer 52 when viewed from the front of the substrate 51 in the light incident direction. The spacing between the plurality of second grooves 57 is also smaller than the length in the radiation direction DA of the spot 40 of the illumination light 30 irradiated onto the phosphor wheel 50. For example, as shown in FIG. 2( a), the spacing between the plurality of 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 by the phosphor layer 52 travels in a direction intersecting the circumferential direction DB, it is reflected by the wall portions 58 of the second grooves 57 and the light diffusing particles 54 a and travels in the Z-axis direction.

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

[0070] 8, in the second embodiment, the longitudinal cross section of the first groove 56 in the first embodiment is changed from, for example, a wedge shape to a trapezoidal shape. Other than this point and the points described below, the first embodiment and the second embodiment have the same configuration, and therefore description thereof will be omitted.

[0071] The groove portion 55A formed in the phosphor layer 52A of the phosphor wheel 50A in the second embodiment has a first groove 56A having a trapezoidal cross section.

[0072] In the phosphor wheel 50A of the second embodiment, the phosphor layer 52A is also formed with grooves 55A, and the grooves 55A are filled with the intermediate layer 54. Therefore, even if light generated in the phosphor layer 52A travels toward the grooves 55A, the light is reflected at the boundary between the phosphor layer 52A and the intermediate layer 54A in the grooves 55A. Therefore, the fluorescent spot generated from the phosphor layer 52A is prevented from spreading beyond the grooves 55A, preventing a decrease in the light utilization efficiency of the fluorescent light. Furthermore, since the multiple first grooves 56A extend in a direction intersecting the circumferential direction DB, light is prevented from escaping in a tangential direction of the circumferential direction DB of the phosphor layer 52A. Furthermore, omitting the reflective layer simplifies the manufacture of the phosphor wheel 50A, and improves the fluorescent light utilization efficiency with a simple configuration.

[0073] As described above, the above-described embodiments have been described as examples of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to these, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made. Furthermore, it is also possible to combine the components described in the above-described embodiments to create new embodiments.

[0074] As described above, the embodiments have been described as examples of the technology of the present disclosure. For this purpose, the accompanying drawings and detailed description have been provided. Therefore, the components described in the accompanying drawings and detailed description may include not only components essential for solving the problem, but also components that are not essential for solving the problem in order to exemplify the above technology. Therefore, the fact that these non-essential components are described in the accompanying drawings or detailed description should not be interpreted as immediately indicating that these non-essential components are essential.

[0075] Furthermore, since the above-described embodiments are intended to illustrate the technology of the present disclosure, various modifications, substitutions, additions, omissions, etc. may be made within the scope of the claims or their equivalents.

[0076] (Outline of the embodiment) (1) The phosphor wheel of the present disclosure comprises a substrate, a phosphor layer formed in a circular ring 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 extending in a direction intersecting the circumferential direction of the phosphor layer and including a plurality of first grooves each 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, eliminating the need to form a reflective film on the substrate, thereby providing a phosphor wheel that can be easily manufactured.

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

[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 so that the first groove widens toward the substrate side.

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

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

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

[0083] (7) In the phosphor wheel of any one of (1) to (6), the groove portion includes a plurality of second grooves extending in the circumferential direction and formed at intervals in a direction intersecting the circumferential direction.

[0084] (8) In the phosphor wheel of (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] (9) In the phosphor wheel of (8), the second groove has a wedge-shaped longitudinal section.

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

[0087] (11) In the phosphor wheel of any one of (7) to (10), the interval between each of the 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.

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

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

[0090] This makes it possible to provide a light source device that can be easily manufactured, since it includes a phosphor wheel that does not require the formation of a reflective film on the substrate.

[0091] (14) A projection type image display device comprising: a light source device according to (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 makes it possible to provide a projection-type image display device that can be easily manufactured, since it includes a phosphor wheel that does not require the formation of a reflective film on the substrate. [Industrial Applicability]

[0093] The present disclosure is applicable to a phosphor wheel that irradiates illumination light and converts the wavelength of the light, a light source device that uses light whose wavelength has been converted by 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 40 spots 50 Phosphor Wheel 50a center axis 51 PCB 51a 1st principal surface 51b Second principal surface 52, 52A Phosphor layer 52a Exposed surface 52b Phosphor particles 52c base 52d convex part 52e Binder 53 Drive motor 54 Middle Class 54a Light diffusing particles 54b base 54c Convex part 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 Optical System 185, 186 Dichroic coating layer 201, 202 Blue semiconductor laser 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 Prisms D1 Thickness D2 Depth DA Radiation Direction DB Circumferential direction Lg1, Lg2 interval Rs1, Rs2 spot diameter W width

Claims

1. A substrate; an intermediate layer disposed on the substrate and including light diffusing particles therein; a phosphor layer formed in a ring shape on the intermediate layer, an end portion of the phosphor layer in a radial direction of the annular shape and an end portion of the intermediate layer in a region where the phosphor layer is located in the radial direction of the annular shape are exposed to the outside; the phosphor layer has a groove recessed from the substrate side toward the exposed surface side of the phosphor layer, The intermediate layer is a base formed on the substrate; a protrusion that fills the groove from the base, the light-diffusing particles are contained in both the base and the protrusions; Phosphor wheel.

2. the groove portion includes a plurality of first grooves extending in a direction intersecting a circumferential direction of the phosphor layer and formed at intervals in the circumferential direction. The phosphor wheel according to claim 1 .

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

4. 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 2 or 3.

5. The first groove has a wedge-shaped longitudinal cross section. The phosphor wheel according to claim 4 .

6. The first groove has a trapezoidal cross section. The phosphor wheel according to claim 4 .

7. a distance between each of the plurality of first grooves is smaller than a length of a spot of light irradiated on the phosphor wheel in a direction perpendicular to the radiation direction of the phosphor layer; The phosphor wheel according to claim 2 .

8. The groove portion includes a plurality of second grooves extending in the circumferential direction and formed at intervals in a direction intersecting the circumferential direction. The phosphor wheel according to claim 2 .

9. the phosphor layer has a second inclined portion that forms at least a part of the second groove and widens toward the substrate side; The phosphor wheel according to claim 8 .

10. The second groove has a wedge-shaped longitudinal cross section. The phosphor wheel according to claim 9 .

11. The second groove has a trapezoidal cross section. The phosphor wheel according to claim 9 .

12. a distance between each of the plurality of second grooves is smaller than a length of the phosphor layer in a radial direction at a spot of light irradiated on the phosphor wheel; The phosphor wheel according to any one of claims 8 to 11.

13. the light-diffusing particles have a refractive index different from that of the intermediate layer; The phosphor wheel according to claim 1 .

14. a phosphor wheel according to any one of claims 1 to 13; a light source unit that generates illumination light; a light guide optical system that guides illumination light from the light source unit to the phosphor wheel; A light source device comprising:

15. The light source device according to claim 14; a light modulation unit that generates image light using light emitted from the light source device; a projection optical system that projects the image light, Projection-type image display device.

16. A substrate; an intermediate layer disposed on the substrate and including light diffusing particles therein; a phosphor layer formed in a ring shape on the intermediate layer, the intermediate layer has a groove and a cross section that is substantially concave-shaped; The groove is filled with the phosphor layer, an end portion of the phosphor layer in a radial direction of the annular shape and an end portion of the intermediate layer in a region where the phosphor layer is located in the radial direction of the annular shape are exposed to the outside; The intermediate layer is a base formed on the substrate; a protrusion protruding from the base toward the phosphor layer, the light-diffusing particles are contained in both the base and the protrusions; Phosphor wheel.

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