JP2019035981A - Phosphor wheel, light source device, projection type video display device, and manufacturing method of phosphor wheel - Google Patents

Abstract

To provide a phosphor wheel capable of improving fluorescent efficiency and thermal conductivity.SOLUTION: A phosphor wheel 1 comprises: a substrate 104; a light reflection layer 107 formed over one surface of the substrate 104; a phosphor layer 101; and an adhesion layer 103 which is positioned between the light reflection layer 107 and the phosphor layer 101 for adhering the light reflection layer 107 and the phosphor layer 101. The adhesion layer 103 contains particles 132 the thermal conductivity of which is higher than that of a base material 131 of the adhesion layer 103 and the light reflectivity of which is higher than that of the light reflection layer 107.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to a phosphor wheel used in, for example, a light source device included in a projection display apparatus.

  Patent Document 1 discloses a configuration of a phosphor wheel in which a titanium oxide layer is provided on a substrate and a phosphor layer is provided on the titanium oxide layer. Such a phosphor wheel has a fluorescent light emitting plate having a fluorescent light emitting portion disposed opposite to the excitation light source, and a reflecting portion having titanium oxide disposed on the opposite side of the excitation light source and joined to the fluorescent light emitting portion. With. When excitation light from the excitation light source is applied to the fluorescent light emitting unit, the fluorescent light emitting unit converts the wavelength of the excitation light, and the wavelength-converted excitation light is reflected by the reflection unit.

  In such a phosphor wheel, the reflectance of the reflecting portion is improved by titanium oxide, so that the light utilization efficiency can be increased and the cost can be reduced.

JP 2013-228598 A

  The present disclosure provides a phosphor wheel with improved fluorescence efficiency and thermal conductivity.

  The phosphor wheel in the present disclosure is located between a substrate, a light reflection layer formed on one surface of the substrate, a phosphor layer, the light reflection layer, and the phosphor layer, and the light reflection And an adhesive layer that adheres the phosphor layer, and the adhesive layer is a particle having a higher thermal conductivity than the base material of the adhesive layer, and has a light reflectance higher than that of the light reflecting layer. Contains high particles.

  According to the present disclosure, the fluorescence efficiency and thermal conductivity of the phosphor wheel are improved.

FIG. 1 is a plan view of the phosphor wheel according to the first embodiment. FIG. 2 is a schematic cross-sectional view of the phosphor wheel according to the first embodiment. FIG. 3 is a diagram showing the influence of the thickness of the adhesive layer on the temperature of the phosphor layer. FIG. 4 is a diagram showing changes in the reflectance of the reflecting surface when the thickness of the adhesive layer is changed for each of the three types of light reflecting layers having different reflectances. FIG. 5 is a diagram illustrating a configuration of the light source device according to the first embodiment. FIG. 6 is a diagram showing a configuration of the projection display apparatus according to the first embodiment. FIG. 7 is a plan view of the phosphor wheel according to the second embodiment. FIG. 8 is a schematic cross-sectional view of the first phosphor layer of the phosphor wheel according to the second embodiment. FIG. 9 is a schematic cross-sectional view of the second phosphor layer of the phosphor wheel according to the second embodiment. FIG. 10 is a diagram illustrating a configuration of the light source device according to the second embodiment. FIG. 11 is a diagram showing a configuration of the projection display apparatus according to the second embodiment.

  Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary 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 the following description from becoming unnecessarily redundant and to facilitate understanding by those skilled in the art.

  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. The accompanying drawings are schematic and are not necessarily exact. In each figure, substantially the same configuration is denoted by the same reference numeral, and redundant description may be omitted or simplified.

(Embodiment 1)
[1-1-1. Overall structure of phosphor wheel]
Hereinafter, the configuration of the phosphor wheel according to Embodiment 1 will be described with reference to FIGS. 1 and 2. FIG. 1 is a plan view of the phosphor wheel according to the first embodiment. 2 is a schematic cross-sectional view of the phosphor wheel according to Embodiment 1 (a schematic cross-sectional view taken along the line II-II in FIG. 1).

  As shown in FIGS. 1 and 2, the phosphor wheel 1 according to the first embodiment includes a substrate 104, a light reflection layer 107, a phosphor layer 101, an adhesive layer 103, and a motor 106.

  The substrate 104 is a disk-shaped plate that is rotationally driven by a motor 106. Although the material of the board | substrate 104 is not specifically limited, The board | substrate 104 is formed with aluminum, for example. Since aluminum has a relatively high thermal conductivity, heat dissipation of the substrate 104 can be improved. Further, since the substrate 104 is formed of aluminum, the weight of the substrate 104 can be reduced. The thickness of the substrate 104 is, for example, 1.5 mm or less.

  A light reflecting layer 107 is formed on at least one surface of the substrate 104. In other words, the light reflection layer 107 is a reflection-enhancing film for improving (increasing) the reflectivity of the surface of the substrate 104 and has a higher reflectivity than the surface (one surface) of the substrate 104. The light reflecting layer 107 is made of, for example, silver or a silver alloy. Although not shown in detail, the light reflecting layer 107 includes an undercoat layer and a topcoat layer. For example, the light reflecting layer 107 is deposited on the entire surface of one surface of the substrate 104. The light reflecting layer 107 may be partially deposited on one surface of the substrate 104.

  The adhesive layer 103 is located between the light reflecting layer 107 and the phosphor layer 101 in the stacking direction, and is in direct contact with each of the light reflecting layer 107 and the phosphor layer 101, so that the light reflecting layer 107 and the phosphor layer 101 are in contact with each other. 101 is bonded. The adhesive layer 103 is formed in a ring shape (annular shape) on the circumference of the same distance from the rotation center of the phosphor wheel 1 on the light reflection layer 107 of the substrate 104. That is, the adhesive layer 103 is formed in a belt shape along the circumferential direction. Further, the adhesive layer 103 is formed not on the entire surface of the light reflecting layer 107 but partially. As shown in FIG. 2, the width of the adhesive layer 103 is the same as the width of the phosphor layer 101 or slightly smaller than the width of the phosphor layer 101 in a plan view (when viewed from a direction perpendicular to the substrate 104). wide. Therefore, the adhesive layer 103 contacts almost the entire lower surface of the phosphor layer 101.

  The adhesive layer 103 includes a base material 131. The base 131 is made of, for example, resin silicone. The adhesive layer 103 (base material 131) contains particles 132 that improve the light reflectivity and the thermal conductivity of the adhesive layer 103. The particles 132 have higher thermal conductivity than the base material 131 of the adhesive layer 103 and higher light reflectance than the light reflecting layer 107.

  The phosphor layer 101 (phosphor ring) emits fluorescence when irradiated with excitation light. The phosphor layer 101 is disposed on the adhesive layer 103, and the adhesive layer 103 protrudes on both sides in the width direction of the phosphor layer 101 in plan view. The phosphor layer 101 is formed in a ring shape (annular shape) on the circumference having the same distance from the rotation center of the phosphor wheel 1. That is, the phosphor layer 101 is formed in a band shape along the circumferential direction in plan view. The phosphor layer 101 is formed in a ring shape in advance, and then adhered and fixed to the light reflecting layer 107 (substrate 104) by the adhesive layer 103. The adhesive layer 103 is applied by a dispenser, for example, but may be screen-printed, and the method for forming the adhesive layer 103 is not particularly limited.

  The phosphor layer 101 is composed of phosphor particles 111 and a binder 112. Specifically, the phosphor particles 111 are YAG-based yellow phosphor particles. In the phosphor layer 101, in order to improve the light conversion efficiency, it is preferable that the amount of the phosphor particles 111 contributing to the conversion from excitation light to fluorescence is large. That is, the phosphor layer 101 should have a larger phosphor ratio (phosphor particle content ratio).

  The binder 112 is a mixture other than the phosphor particles 111 constituting the phosphor layer 101. The binder 112 is formed of an inorganic material having high thermal conductivity such as alumina. The thermal conductivity of alumina is 10 times or more that of resin silicone, and the phosphor layer 101 is composed of the phosphor particles 111 and the binder 112 formed of alumina, so that high thermal conductivity is achieved. The phosphor layer 101 can be realized.

  The motor 106 rotationally drives the phosphor wheel 1. The motor 106 is, for example, an outer rotor type motor, but is not particularly limited.

[1-1-2. Detailed configuration of adhesive layer]
As described above, as the base material 131 of the adhesive layer 103, for example, a resin silicone having an adhesive function is used. Thereby, the distortion produced by the difference in the thermal expansion coefficient between the light reflection layer 107 (substrate 104) and the phosphor layer 101 can be buffered, and the shape of the phosphor wheel 1 can be maintained. In consideration of the characteristic of buffering the strain, a dimethyl resin silicone may be used as the resin silicone used for the adhesive layer 103. Further, the dimethyl resin silicone is advantageous in that it does not easily discolor even during long-term use, and the light transmittance is unlikely to decrease.

  On the other hand, the resin silicone itself has a low thermal conductivity. For this reason, in the phosphor wheel 1, the resin silicone that is the base material 131 includes particles 132 that have higher thermal conductivity than the resin silicone and higher light reflectance than the light reflecting layer 107. . The adhesive layer 103 including the particles 132 can simultaneously realize suppression of distortion caused by the difference in thermal expansion coefficient between the phosphor layer 101 and the substrate 104, improvement in thermal conductivity, and improvement in light reflectance. it can.

  Thus, in order to realize improvement in reflectance and improvement in thermal conductivity by the particles 132, the particles 132 are formed of, for example, titanium oxide, alumina, or a mixture of titanium oxide and alumina. In particular, in titanium oxide, alumina, and a mixture of titanium oxide and alumina, titanium oxide is particularly desirable in terms of reflectivity and thermal conductivity. When resin silicone is used as the base material 131 and the particles 132 are formed of titanium oxide, the content of the particles 132 is 10% of the entire adhesive layer 103 in consideration of strain buffering properties, reflectance, and thermal conductivity. % Or more and about 20% or less.

  By the way, as the thickness of the adhesive layer 103 is reduced, the thermal resistance is reduced, so that the temperature rise of the phosphor layer 101 is suppressed. FIG. 3 is a diagram illustrating the influence of the thickness of the adhesive layer 103 on the temperature of the phosphor layer 101. Note that the temperature of the phosphor layer 101 shown on the vertical axis in FIG. 3 is normalized to 1 by estimating the temperature when the thickness of the adhesive layer 103 is 0 μm. Note that FIG. 3 shows the temperature when titanium oxide is used as the particles 132.

  As described above, the thermal conductivity of the particles 132 formed of titanium oxide or alumina is about 10 times or more that of the resin silicone. For this reason, when the thickness of the adhesive layer 103 is increased, the temperature rise is greater when the adhesive layer 103 contains particles 132 (graph 301) and when the adhesive layer 103 does not contain particles 132 (graph 302). Smaller than.

  When the temperature of the phosphor layer 101 rises, a phenomenon called temperature quenching that reduces the light conversion efficiency occurs. For this reason, the temperature of the phosphor layer 101 is preferably low. In other words, the adhesive layer 103 should be thin. Considering the upper limit temperature of the phosphor wheel 1 based on the fluorescence efficiency, the thickness of the adhesive layer 103 is, for example, 80 μm or less.

  On the other hand, as the thickness of the adhesive layer 103 is increased, the strain buffering property and the reflectance are improved. Therefore, in order to suppress the temperature rise of the phosphor layer 101, the thickness of the adhesive layer 103 is preferably reduced within a range in which the strain buffering property and the reflectance are ensured. Therefore, the thickness of the adhesive layer 103 necessary for securing the strain buffering property and the thickness of the adhesive layer 103 necessary for securing the reflectance will be described.

  First, the thickness of the adhesive layer 103 for ensuring the strain buffering property will be described. The thickness of the adhesive layer 103 for ensuring the strain buffering property can be calculated from the amount of strain generated by the mechanical strength characteristics of the substrate 104, the adhesive layer 103, and the phosphor layer 101. For example, it is assumed that the substrate 104 is formed of aluminum, YAG-based yellow phosphor particles are used as the phosphor particles 111 of the phosphor layer 101, and alumina is used as the binder 112 of the phosphor layer 101. When dimethyl resin silicone is used as the base material 131 for the adhesive layer 103 and the particles 132 are formed of titanium oxide, the thickness of the adhesive layer 103 is preferably 30 μm or more. This numerical value is determined in consideration of the result of a reliability test such as a heat cycle test.

  Next, the thickness of the adhesive layer 103 for ensuring the reflectance will be described. The light conversion efficiency (fluorescence efficiency) of the phosphor layer 101 is high in the reflectivity of the adjacent reflecting surface (the surface for reflecting fluorescence formed by the adhesive layer 103, the light reflecting layer 107, and the substrate 104). Depends on. This is because the reflecting surface reflects the excitation light that has not been incident on the phosphor particles 111 (which has not contributed to the fluorescence conversion), so that the excitation light is incident on the phosphor particles 111 in the phosphor layer 101. This is because the fluorescence output increases.

  The fluorescence emitted from the phosphor particles 111 is emitted in all directions. For this reason, fluorescence output can be increased by reflecting fluorescence by the reflective surface. Thus, the higher the reflectance at the reflecting surface, the higher the fluorescence output. Note that the reflectance of the reflection surface is determined by the reflection characteristics of the adhesive layer 103 and the light reflection layer 107.

  Here, the relationship between the thickness of the adhesive layer 103 and the reflectance of the reflecting surface will be described. FIG. 4 is a diagram showing the relationship between the thickness of the adhesive layer 103 and the reflectance of the reflecting surface. FIG. 4 is a diagram showing changes in the reflectance of the reflecting surface when the thickness of the adhesive layer 103 is changed for each of the three types of light reflecting layers 107 having different reflectances. As the adhesive layer 103, dimethyl silicone was used as the base material 131, and an adhesive containing titanium oxide in a weight content of 10% to 15% was used as the particles 132.

  In FIG. 4, the change when the reflectance of the light reflection layer 107 is 90% when the adhesive layer 103 is not provided is 0 μm, and the change when the reflectance of the light reflection layer 107 is 70%. The graph 402 shows the change when the reflectance of the light reflection layer 107 is 50%.

  As shown in the graph 401, the graph 402, and the graph 403, regardless of the reflectance of the light reflecting layer 107, the reflectance of the reflecting surface is saturated when the thickness of the adhesive layer 103 exceeds a certain value. Specifically, when the thickness of the adhesive layer 103 is 60 μm or more, the reflectance of the reflecting surface is saturated and does not change regardless of the reflectance of the light reflecting layer 107 (the reflectance of the substrate 104). However, the higher the reflectance of the light reflecting layer 107, the more saturated the reflectance becomes due to the formation of the thin adhesive layer 103. In FIG. 4, when the reflectance of the light reflecting layer 107 exceeds 90%, the reflectance of the reflecting surface is saturated if the thickness of the adhesive layer 103 is 30 μm.

  As described above, in order to improve the reflectance of the reflecting surface and reduce the thickness of the adhesive layer 103, the reflectance of the substrate 104 (light reflecting layer 107) is preferably 90% or more. The material of the substrate 104 is preferably aluminum or an aluminum alloy from the viewpoints of rigidity, thermal conductivity, and lightness for maintaining the rotation as a phosphor wheel. However, it is difficult for aluminum or an aluminum alloy to have a reflectance of 90% or more by itself.

  Therefore, in the phosphor wheel 1, the light reflecting layer 107 formed of silver or a silver alloy is provided on the surface of the substrate 104 formed of aluminum, and the reflectance of the reflecting surface is 90% or more. In addition, as the light reflecting layer 107, an aluminum film, a dielectric multilayer film, or the like can be used.

  As described above, the phosphor wheel 1 is preferably formed as follows, for example.

  -The light reflection layer 107 formed on the surface of the substrate 104 may have a reflectance of 90% or more.

  The adhesive layer 103 preferably includes at least particles 132 formed of titanium oxide.

  The thickness of the adhesive layer 103 is preferably 30 μm or more and 80 μm or less in order to ensure reliability (strain buffering property) and fluorescence efficiency.

[1-1-3. Effect]
As described above, the phosphor wheel 1 includes the substrate 104, the light reflection layer 107 formed on one surface of the substrate 104, the phosphor layer 101, and the light reflection layer 107 and the phosphor layer 101. And an adhesive layer 103 that adheres the light reflecting layer 107 and the phosphor layer 101 to each other. The adhesive layer 103 includes particles 132 having higher thermal conductivity than the base material 131 of the adhesive layer 103 and higher light reflectance than the light reflecting layer 107.

  Thus, by including the particles 132 in the adhesive layer 103, the fluorescence efficiency and thermal conductivity of the phosphor wheel 1 are improved.

  For example, the light reflection layer 107 includes a silver alloy and has a light reflectance of 90% or more.

  Thereby, reflection of the fluorescence emitted from the phosphor layer 101 can be enhanced.

  For example, the thickness of the adhesive layer 103 is 30 μm or more and 80 μm or less.

  Thereby, the reliability (strain buffering property) and fluorescence efficiency of the phosphor wheel 1 can be ensured.

  For example, the particles 132 contained in the adhesive layer 103 are formed of titanium oxide.

  Thus, according to the particles 132 formed of titanium oxide, the fluorescence efficiency and thermal conductivity of the phosphor wheel 1 can be improved.

  For example, the particles 132 contained in the adhesive layer 103 are formed of alumina.

  Thus, according to the particles 132 formed of alumina, the fluorescence efficiency and thermal conductivity of the phosphor wheel 1 can be improved.

  For example, the particles 132 contained in the adhesive layer 103 may include particles formed of titanium oxide and particles formed of alumina.

  Thus, if the particles 132 formed of titanium oxide and the particles 132 formed of alumina are mixed in the adhesive layer 103, the fluorescence efficiency and thermal conductivity of the phosphor wheel 1 can be improved.

  Further, for example, the substrate 104 has a disk shape, and the phosphor layer 101 and the adhesive layer 103 have a band shape along the circumferential direction of the substrate 104.

  Thereby, since the phosphor layer 101 and the adhesive layer 103 are selectively disposed only in a necessary region of the light reflecting layer 107, the component cost of the phosphor layer 101 and the adhesive layer 103 can be reduced.

  In addition, the phosphor wheel 1 is manufactured by forming the light reflecting layer 107 on one surface of the substrate 104, forming the phosphor layer 101, and forming the adhesive layer 103 on the light reflecting layer 107. By placing the phosphor layer 101 on the adhesive layer 103, the molded phosphor layer 101 is adhered and fixed to the light reflecting layer 107. The adhesive layer 103 has a thermal conductivity higher than that of the base material of the adhesive layer 103. The particles 132 are high particles 132 that have a light reflectance higher than that of the light reflecting layer 107.

  Thereby, the phosphor wheel 1 with improved fluorescence efficiency and thermal conductivity can be manufactured.

[1-2-1. Light source device including phosphor wheel]
Next, the light source device according to Embodiment 1 will be described with reference to FIG. FIG. 5 is a diagram illustrating a configuration of the light source device according to the first embodiment.

  As shown in FIG. 5, the light source device 5 according to the first embodiment includes a phosphor wheel 1 and a plurality of first lasers 502. The first laser 502 is an example of an excitation light source.

  The light source device 5 includes a plurality of collimator lenses 503, a convex lens 504, a diffusion plate 505, a concave lens 506, a dichroic mirror 507, a convex lens 508, and a convex lens 509. These optical components are an example of an optical system that guides the emitted light from the first laser 502 to the phosphor wheel 1. The light source device 5 includes a plurality of second lasers 522, a plurality of collimator lenses 523, a convex lens 524, a diffusion plate 525, a convex lens 510, and a rod integrator 511.

  Light emitted from each of the plurality of first lasers 502 is collimated by a collimator lens 503 disposed on the emission side of the first laser 502. On the emission side of the plurality of collimator lenses 503, a convex lens 504 that reduces the beam width by combining the lights of the first lasers 502 emitted from the plurality of collimator lenses 503 is disposed. The light whose beam width has been reduced by the convex lens 504 enters a diffusion plate 505 disposed on the exit side of the convex lens 504. The diffuser plate 505 reduces the non-uniformity of the light flux that could not be eliminated by the convex lens 504.

  The light emitted from the diffusion plate 505 enters the concave lens 506. The concave lens 506 collimates the light incident from the diffusion plate 505.

  The collimated light emitted from the concave lens 506 is incident on a dichroic mirror 507 disposed on the exit side of the concave lens 506. The dichroic mirror 507 is disposed at an angle of 45 degrees with respect to the optical axis, transmits light in the wavelength region of the light emitted from the first laser 502, and emits fluorescence emitted from the phosphor wheel 1. It has the characteristic of reflecting light in the wavelength range of. Accordingly, the light emitted from the concave lens 506 that has entered the dichroic mirror 507 is transmitted through the dichroic mirror 507, and is incident on the phosphor wheel 1 in a state where the light flux is converged by entering the convex lens 508 and the convex lens 509 in this order.

  The phosphor wheel 1 is disposed so that the phosphor layer 101 faces the convex lens 509. The light of the first laser 502 converged by the convex lens 508 and the convex lens 509 is irradiated as excitation light that excites the phosphor particles 111 in the phosphor layer 101. Here, as described above, the phosphor layer 101 included in the phosphor wheel 1 has a ring shape, and the phosphor wheel 1 is rotated by the motor 106, so that excitation light is concentrated on one point of the phosphor layer 101. Irradiation is suppressed.

  The excitation light from the first laser 502 incident on the phosphor layer 101 is wavelength-converted. That is, the excitation light from the first laser 502 is converted into fluorescence having a wavelength range different from that of the excitation light. Further, the fluorescence emitted from the phosphor layer 101 is converted in the traveling direction by 180 degrees with respect to the light incident on the phosphor layer 101. That is, the fluorescence is emitted to the convex lens 509 side. The fluorescence incident on the convex lens 509 is incident on the convex lens 508, converted into parallel light, and incident on the dichroic mirror 507.

  As described above, the dichroic mirror 507 is disposed at an angle of 45 degrees with respect to the optical axis of fluorescence. The dichroic mirror 507 has a characteristic of transmitting light in the wavelength region of the emitted light of the first laser 502 and reflecting light in the wavelength region of fluorescence from the phosphor layer 101 (phosphor wheel 1). Yes. Therefore, the fluorescence incident on the dichroic mirror 507 is reflected and the traveling direction changes by 90 degrees.

  On the other hand, light emitted from each of the plurality of second lasers 522 is converted into parallel light by a collimator lens 523 disposed on the emission side of the second laser 522. On the emission side of the plurality of collimator lenses 523, a convex lens 524 that reduces the beam width by combining the lights of the second lasers 522 emitted from the plurality of collimator lenses 523 is disposed. The light whose beam width is reduced by the convex lens 524 is incident on the diffusion plate 525 disposed on the exit side of the convex lens 524. The diffusion plate 525 reduces the non-uniformity of the light flux that could not be eliminated by the convex lens 524.

  Light emitted from the diffusion plate 525 enters the concave lens 526. The concave lens 526 converts the light incident from the diffusion plate 525 into parallel light.

  The collimated light emitted from the concave lens 526 enters the dichroic mirror 507 disposed on the exit side of the concave lens 526 from a direction different from the fluorescence emitted from the phosphor wheel 1 by 90 degrees. As described above, the dichroic mirror 507 has a characteristic of transmitting light in the wavelength region of the emitted light of the second laser 522. The light from the concave lens 526 that has entered the dichroic mirror 507 passes through the dichroic mirror 507. As a result, the fluorescence emitted from the phosphor wheel 1 and the light emitted from the second laser 522 are emitted in the same direction.

  The fluorescence emitted from the phosphor wheel 1 and the light emitted from the second laser 522 are converged by the convex lens 510 and enter the rod integrator 511. The rod integrator 511 is an example of a light uniformizing unit, and the intensity distribution of the light emitted by the rod integrator 511 is uniformed.

  Note that light emitted from the second laser 522 is light in the blue wavelength region, and light emitted from the first laser 502 is light in the ultraviolet to blue wavelength region. The phosphor wheel 1 is excited by light (excitation light) emitted from the first laser 502, and emits yellow fluorescence including both green and red wavelength regions. Therefore, the rod integrator 511 emits white light with a uniform intensity distribution.

[1-2-2. Effect]
As described above, the light source device 5 includes the phosphor wheel 1, the first laser 502, and the optical system that guides the emitted light from the first laser 502 to the phosphor wheel 1. The first laser 502 is an example of an excitation light source.

  In such a light source device 5, the fluorescent efficiency and thermal conductivity of the phosphor wheel 1 are improved.

[1-3-1. Projection-type image display device having light source device]
Next, the projection display apparatus according to Embodiment 1 will be described with reference to FIG. FIG. 6 is a diagram showing a configuration of the projection display apparatus according to the first embodiment.

  As shown in FIG. 6, the projection display apparatus 15 includes the light source device 5 described above. The projection display apparatus 15 includes a convex lens 531, a convex lens 532, a convex lens 533, a total reflection prism 534, a color prism 536, a DMD (Digital Micromirror Device) 538, a DMD 539, a DMD 540, and a projection lens. 541.

  In the following, the details of the light source device 5 are omitted, and the behavior of white light emitted from the rod integrator 511 will be described.

  White light emitted from the rod integrator 511 is mapped to each of DMD 538, DMD 539, and DMD 540, which will be described later, by a relay lens system including three convex lenses of a convex lens 531, a convex lens 532, and a convex lens 533.

  The light transmitted through the convex lens 531, the convex lens 532, and the convex lens 533 constituting the relay lens system enters the total reflection prism 534. The total reflection prism 534 has two glass blocks, and a minute gap 535 is provided between the two glass blocks. The light that has entered the total reflection prism 534 is reflected by the minute gap 535 and enters the color prism 536.

  The color prism 536 has three glass blocks, a first glass block, a second glass block, and a third glass block. The first glass block is a glass block arranged opposite to DMD 538, the second glass block is a glass block arranged opposite to DMD 539, and the third glass block is arranged opposite to DMD 540. Glass block.

  A minute gap 537 is provided between the first glass block and the second glass block. In addition, the color prism 536 has a dichroic surface that reflects light in the blue wavelength region on the first glass block side between the first glass block and the second glass block.

  Of the white light that has entered the color prism 536 from the total reflection prism 534, the light in the blue wavelength region is reflected by the dichroic surface, and is totally reflected at the gap provided between the color prism 536 and the total reflection prism 534. Then, the traveling direction is changed and the light enters the blue DMD 538.

  On the other hand, the light that has passed through the minute gap 537 and entered the second glass block becomes yellow light including light in both the red wavelength range and the green wavelength range. Yellow light is incident on a dichroic surface provided at the boundary surface between the second glass block and the third glass block of the color prism 536. This dichroic surface has a characteristic of reflecting light in the red wavelength range (hereinafter also referred to as red light) and transmitting light in the green wavelength range (hereinafter also referred to as green light). Therefore, yellow light is separated into red light and green light on the dichroic surface. Specifically, among yellow light, red light is reflected on the dichroic surface, and green light is transmitted through the dichroic surface and is incident on the third glass block.

  The red light reflected on the dichroic surface is totally reflected by being incident on the minute gap 537 at an incident angle greater than the critical angle, and is incident on the DMD 539 for red.

  The green light incident on the third glass block goes straight and enters the green DMD 540.

  Each of the DMD 538, the DMD 539, and the DMD 540 is driven by a video circuit (not shown), and each pixel is switched on / off corresponding to the image information. Thereby, the reflection direction of the light incident on each pixel of DMD 538, DMD 539, and DMD 540 changes for each pixel.

  In each of DMD 538, DMD 539, and DMD 540, the light reflected by the pixels in the ON state passes through the above-described path in the reverse direction, is synthesized by the color prism 536, becomes white light, and enters the total reflection prism 534. . The light incident on the total reflection prism 534 enters the minute gap 535 at an angle smaller than the critical angle and passes through the minute gap 535 as it is. The light transmitted through the minute gap 535 is enlarged and projected onto a screen (not shown) by the projection lens 541.

[1-3-2. Effect]
As described above, the projection display apparatus 15 includes the light source device 5. In such a projection display apparatus 15, the fluorescence efficiency and thermal conductivity of the phosphor wheel 1 are improved.

(Embodiment 2)
[2-1-1. Configuration of phosphor wheel]
Hereinafter, the structure of the phosphor wheel according to the second embodiment will be described with reference to FIGS. FIG. 7 is a plan view of the phosphor wheel according to the second embodiment. FIG. 8 is a schematic cross-sectional view of the first phosphor layer of the phosphor wheel according to Embodiment 2 (schematic cross-sectional view taken along line VIII-VIII in FIG. 7). FIG. 9 is a schematic cross-sectional view (schematic cross-sectional view taken along line IX-IX in FIG. 7) of the second phosphor layer of the phosphor wheel according to the second embodiment.

  As shown in FIGS. 7 to 9, the phosphor wheel 2 according to Embodiment 2 includes a substrate 204, a light reflection layer 207, a first phosphor layer 201, and a second phosphor layer 202. , An adhesive layer 203, an opening 205, and a motor 206.

  The substrate 204 is a disk-shaped plate that is rotationally driven by a motor 206. Although the material of the board | substrate 204 is not specifically limited, The board | substrate 204 is formed with aluminum, for example. Since aluminum has a relatively high thermal conductivity, heat dissipation of the substrate 204 can be improved. Further, since the substrate 204 is formed of aluminum, the weight of the substrate 204 can be reduced. As shown in FIG. 7, the substrate 204 is provided with an opening 205 (through hole). As shown in FIGS. 8 and 9, a light reflecting layer 207 is formed on at least one surface of the substrate 204.

  In other words, the light reflecting layer 207 is a reflection increasing film for improving (increasing) the reflectance of the surface of the substrate 204, and has a higher reflectance than that of the surface of the substrate 204. The light reflection layer 207 is made of, for example, silver or a silver alloy. Although not shown in detail, the light reflecting layer 207 includes an undercoat layer and a topcoat layer.

  The adhesive layer 203 adheres the light reflecting layer 207 and the first phosphor layer 201. The adhesive layer 203 bonds the light reflecting layer 207 and the second phosphor layer 202. The adhesive layer 203 is formed on the circumference of which the distance from the rotation center of the phosphor wheel 2 is equal on the light reflection layer 207 of the substrate 204. The opening 205 and the adhesive layer 203 provided in the substrate 204 are formed so as to form a ring shape. The adhesive layer 203 includes a base material 231. The base material 231 is made of, for example, resin silicone. The adhesive layer 203 (base material 231) contains particles 232 that improve the reflectance of light and the thermal conductivity of the adhesive layer 203. The particles 232 have higher thermal conductivity than the base material 231 of the adhesive layer 203 and higher light reflectance than the light reflecting layer 207.

  The first phosphor layer 201 and the second phosphor layer 202 emit fluorescence when irradiated with excitation light. Each of the first phosphor layer 201 and the second phosphor layer 202 has a partial ring inside the adhesive layer 203 in a plan view and on a circumference having the same distance from the rotation center of the phosphor wheel 2. It is formed in a shape (arc shape). That is, each of the first phosphor layer 201 and the second phosphor layer 202 is formed in a strip shape along the circumferential direction.

  As shown in FIG. 8, the first phosphor layer 201 is composed of phosphor particles 211 and a first binder 212. Also, as shown in FIG. 9, the second phosphor layer 202 is composed of phosphor particles 213 and a second binder 214.

  The phosphor particles 211 and the phosphor particles 213 are different from each other. The phosphor particles 211 are, for example, yellow phosphor particles, and the phosphor particles 213 are, for example, green phosphor particles.

  The first binder 212 and the second binder 214 are formed of an inorganic substance such as alumina, for example. The first binder 212 and the second binder 214 may be formed of different materials, or may be formed of the same material.

  For the same reason as described in the first embodiment, the phosphor wheel 2 may be formed as follows, for example.

  -The light reflection layer 207 formed on the surface of the substrate 204 may have a reflectance of 90% or more.

  The adhesive layer 203 preferably includes at least particles 232 formed of titanium oxide.

  -The thickness of the contact bonding layer 203 is good in it being 30 micrometers or more and 80 micrometers or less.

[2-1-2. Effect]
As described above, in the phosphor wheel 2, the fluorescent efficiency and the thermal conductivity are improved by including the particles 232 in the adhesive layer 203, as in the phosphor wheel 1.

  The number of segments of the phosphor layer is not limited to two, and may be one or three or more. Further, the substrate 204 may not be provided with the opening 205, and may be provided with two or more openings 205.

[2-2-1. Light source device including phosphor wheel]
Next, the light source device according to Embodiment 2 will be described with reference to FIG. FIG. 10 is a diagram illustrating a configuration of the light source device according to the second embodiment.

  As shown in FIG. 10, the light source device 6 according to Embodiment 2 includes a phosphor wheel 2 and a plurality of lasers 602. The laser 602 is an example of an excitation light source.

  The light source device 6 includes a plurality of collimator lenses 603, a convex lens 604, a diffuser plate 605, a concave lens 606, a dichroic mirror 607, a convex lens 608, and a convex lens 609. These optical components are examples of an optical system that guides emitted light from the laser 602 to the phosphor wheel 2. The light source device 6 includes a convex lens 610, a convex lens 611, a mirror 612, a lens 613, a mirror 614, a lens 615, a mirror 616, a lens 617, a convex lens 618, a color wheel 619, and a rod integrator. 620.

  Light emitted from each of the plurality of lasers 602 is collimated by a collimator lens 603 disposed on the emission side of the laser 602. On the emission side of the plurality of collimator lenses 603, a convex lens 604 is arranged to reduce the beam width by collecting the light of the lasers 602 emitted from the plurality of collimator lenses 603. The light whose beam width is reduced by the convex lens 604 is incident on the diffusion plate 605 positioned on the exit side of the convex lens 604. The diffuser plate 605 reduces the non-uniformity of the light flux that could not be eliminated by the convex lens 604. Hereinafter, an example in which the laser 602 emits light in the blue wavelength region will be described.

  The light emitted from the diffuser plate 605 enters the concave lens 606. The concave lens 606 converts the light incident from the diffusion plate 605 into parallel light.

  The collimated light emitted from the concave lens 606 enters a dichroic mirror 607 disposed on the exit side of the concave lens 606. The dichroic mirror 607 is disposed at an angle of 45 ° C. with respect to the optical axis, reflects the light in the wavelength range of the light emitted from the laser 602, and reflects the wavelength range of the fluorescence emitted from the phosphor wheel 2. It has the characteristic of transmitting the light. Therefore, the light emitted from the concave lens 606 that has entered the dichroic mirror 607 is reflected by the dichroic mirror 607, and then enters the plurality of convex lenses 608 and convex lens 609 in this order, so that the phosphor wheel 2 in a state where the light flux is converged. Is incident on.

  The phosphor wheel 2 is disposed so that any one of the first phosphor layer 201, the second phosphor layer 202, and the opening 205 faces the convex lens 609. When the phosphor wheel 2 is rotated by the motor 206, the first phosphor layer 201, the second phosphor layer 202, and the opening 205 sequentially pass through the positions facing the convex lens 609. In other words, when the phosphor wheel 2 rotates, the light of the laser 602 converged by the convex lens 608 and the convex lens 609 is time-series in the first phosphor layer 201, the second phosphor layer 202, and the opening 205. Is irradiated.

  First, a case where the first phosphor layer 201 is irradiated with the light of the laser 602 will be described. The light of the laser 602 incident on the first phosphor layer 201 is wavelength-converted to first fluorescence and emitted to the convex lens 609. Unlike the light of the laser 602, the first fluorescence is, for example, yellow light (light in the red and green wavelength ranges). The first fluorescence incident on the convex lens 609 is incident on the convex lens 608, converted into parallel light, and incident on the dichroic mirror 607.

  Next, a case where the second phosphor layer 202 is irradiated with the light of the laser 602 will be described. The light of the laser 602 incident on the second phosphor layer 202 is wavelength-converted to second fluorescence and emitted to the convex lens 609. Unlike both the light of the laser 602 and the first fluorescence, the second fluorescence is green light (light in a green wavelength range). The second fluorescence incident on the convex lens 609 is incident on the convex lens 608 to be converted into parallel light and incident on the dichroic mirror 607.

  Finally, a case where the opening 205 is irradiated with light from the laser 602 will be described. The light of the laser 602 that has passed through the opening 205 enters the convex lens 610 and the convex lens 611 in order, and is converted into parallel light.

  The collimated light emitted from the convex lens 611 is changed in its traveling direction by a relay optical system composed of three mirrors 612, 614, 616 and three lenses 613, 615, 617. The light is collimated again and enters the dichroic mirror 607. This light (light of the laser 602) enters the dichroic mirror 607 from a direction that is 90 degrees different from the first fluorescence and the second fluorescence.

  As described above, the first fluorescence, the second fluorescence, and the light of the laser 602 are incident on the dichroic mirror 607 in time series. As described above, the dichroic mirror 607 has a characteristic of reflecting the light of the laser 602 and transmitting the first fluorescence and the second fluorescence. For this reason, the light of the laser 602 is reflected by the dichroic mirror 607 and the traveling direction is changed by 90 degrees, and is incident on the convex lens 618 to converge the light beam. The first fluorescence and the second fluorescence pass through the dichroic mirror 607 and enter the convex lens 618, and the light flux is converged. From the convex lens 618, yellow light as the first fluorescence, green light as the second fluorescence light, and blue light from the laser 602 are sequentially emitted and enter the color wheel 619.

  The color wheel 619 includes a first region that transmits light and a second region that selectively transmits only red light. The color wheel 619 is rotated so that the second region faces the convex lens 618 in at least a part of the period in which the first fluorescence is incident on the color wheel 619. Thereby, the first fluorescence is converted into red light in the color wheel 619. Such control of the phosphor wheel 2 and the color wheel 619 is performed by a synchronization circuit and a wheel driving circuit (not shown).

  Then, red light, green light, and blue light are sequentially emitted from the color wheel 619, and the emitted red light, green light, and blue light are incident on the rod integrator 620. The rod integrator 620 is an example of a light uniformizing unit.

[2-2-2. Effect]
As described above, the light source device 6 includes the phosphor wheel 2, the laser 602, and the optical system that guides the emitted light from the laser 602 to the phosphor wheel 2. The laser 602 is an example of an excitation light source.

  In such a light source device 6, the fluorescence efficiency and thermal conductivity of the phosphor wheel 1 are improved.

  The configuration of the light source that sequentially emits red light, green light, and blue light is not limited to the configuration of the light source device 6. For example, the phosphor particles 211 included in the first phosphor layer 201 may be red phosphor particles. That is, the first fluorescence may be red light, and in this case, the color wheel 619 may be omitted.

  Further, the number of segments of the phosphor layer is not limited to two, and may be one or three or more.

  For example, the light source device 6 may include the phosphor wheel 2 in which the second phosphor layer 202 is replaced with the first phosphor layer 201. In such a phosphor wheel 2, the number of segments of the phosphor layer is one, but the color wheel 619 has a region that transmits red light and a region that transmits green light, so that red light, Green light and blue light are emitted sequentially.

  Further, the light emitted from the laser 602 may be ultraviolet light instead of blue. In this case, in the phosphor wheel 2, a third phosphor layer that is excited by ultraviolet light and emits blue light may be disposed instead of the opening 205. The third phosphor layer emits blue light by including blue phosphor particles. In such a phosphor wheel 2, the number of segments of the phosphor layer is three.

  Further, an opening is provided at the boundary between the first phosphor layer 201 and the second phosphor layer 202 so that the first phosphor layer 201 and the second phosphor layer 202 are not adjacent to each other. Also good.

[2-3-1. Projection-type image display device having light source device]
Next, a projection display apparatus according to Embodiment 2 will be described with reference to FIG. FIG. 11 is a diagram showing a configuration of the projection display apparatus according to the second embodiment.

  As shown in FIG. 11, the projection display apparatus 16 includes the light source device 6 described above. In addition, the projection display apparatus 16 includes a convex lens 621, a convex lens 622, a convex lens 623, a total reflection prism 624, a DMD 626, and a projection lens 627.

  In the following description, the details of the light source device 6 are omitted, and the behavior of light emitted from the rod integrator 620 will be described.

  The white light emitted from the rod integrator 620 is mapped to a DMD 626 described later by a relay lens system including three convex lenses of a convex lens 621, a convex lens 622, and a convex lens 623.

  The light transmitted through the convex lens 621, the convex lens 622, and the convex lens 623 constituting the relay lens system enters the total reflection prism 624. The total reflection prism 624 has two glass blocks, and a minute gap 625 is provided between the two glass blocks. The light that has entered the total reflection prism 624 is totally reflected by entering the minute gap 625 at an incident angle that is equal to or greater than the critical angle, and enters the DMD 626.

  A video signal synchronized with the phosphor wheel 2 and the color wheel 619 is supplied to the DMD 626 by a circuit (not shown), and ON / OFF of each pixel is switched corresponding to the supplied video signal (image information). Thereby, the reflection direction of the light incident on the DMD 626 changes for each pixel.

  The light reflected by the pixel in the ON state in the DMD 626 enters the total reflection prism 624. The light incident on the total reflection prism 624 enters the minute gap 625 at an angle smaller than the critical angle, and passes through the minute gap 625 as it is. The light transmitted through the minute gap 625 is enlarged and projected onto a screen (not shown) by the projection lens 627.

[2-3-2. Effect]
As described above, the projection display apparatus 16 includes the light source device 6. In such a projection display apparatus 16, the fluorescent efficiency and thermal conductivity of the phosphor wheel 2 are improved.

(Summary)
As described above, Embodiments 1 and 2 have been described as examples of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can also be applied to an embodiment in which changes, replacements, additions, omissions, and the like are appropriately performed. Moreover, it is also possible to combine each component demonstrated in the said Embodiment 1-2 and it can also be set as a new embodiment.

  For example, the stacked structure shown in the cross-sectional view of the above embodiment is an example, and the present disclosure is not limited to the stacked structure. That is, the present disclosure also includes a stacked structure that can realize the characteristic functions of the present disclosure as in the above-described stacked structure. For example, another layer may be provided between the layers of the stacked structure as long as the same function as the stacked structure can be realized.

  In the above embodiment, the main materials constituting each layer of the stacked structure are illustrated, but each layer of the stacked structure includes other materials as long as the same function as the stacked structure can be realized. Also good.

  In addition, among the components described in the accompanying drawings and detailed description, not only the components essential for solving the problem, but also the components not essential for solving the problem in order to exemplify the above technique. May also be included. Therefore, it should not be immediately recognized that these non-essential components are essential as those non-essential components are described in the accompanying drawings and detailed description.

  Further, each of the above-described embodiments is for exemplifying the technique in the present disclosure, and thus various modifications, replacements, additions, omissions, and the like can be performed within the scope of the claims or an equivalent scope thereof.

  The phosphor wheel of the present disclosure can be applied to a projection-type image display device or other illumination device.

DESCRIPTION OF SYMBOLS 1, 2 Phosphor wheel 5, 6 Light source device 15, 16 Projection type image display apparatus 101 Phosphor layer 103, 203 Adhesive layer 104, 204 Substrate 106, 206 Motor 107, 207 Light reflection layer 111, 211, 213 Phosphor particle 112 Binder 131, 231 Base material 132, 232 Particle 201 First phosphor layer 202 Second phosphor layer 205 Opening 212 First binder,
214 Second binder 301, 302, 401, 402, 403 Graph 502 First laser 503, 523, 603 Collimator lens 504, 508, 509, 510, 524, 531, 532, 533, 604, 608, 609, 610 , 611, 618, 621, 622, 623 Convex lens 505, 525, 605 Diffuser plate 506, 526, 606 Concave lens 507, 607 Dichroic mirror 511, 620 Rod integrator 522 Second laser 534, 624 Total reflection prism 535, 537, 625 Micro gap 536 Color prism 538, 539, 540, 626 DMD
541, 627 Projection lens 602 Laser 612, 614, 616 Mirror 613, 615, 617 Lens 619 Color wheel

Claims (10)

A substrate,
A light reflecting layer formed on one surface of the substrate;
A phosphor layer;
An adhesive layer located between the light reflection layer and the phosphor layer, for bonding the light reflection layer and the phosphor layer;
The phosphor layer includes particles having a higher thermal conductivity than the base material of the adhesive layer and having a light reflectance higher than that of the light reflecting layer. The phosphor wheel according to claim 1, wherein the light reflection layer includes a silver alloy and has a light reflectance of 90% or more. The phosphor wheel according to claim 1, wherein the adhesive layer has a thickness of 30 μm or more and 80 μm or less. The phosphor wheel according to any one of claims 1 to 3, wherein the particles contained in the adhesive layer are formed of titanium oxide. The phosphor wheel according to any one of claims 1 to 3, wherein the particles contained in the adhesive layer are formed of alumina. The phosphor wheel according to claim 1, wherein the particles contained in the adhesive layer include particles formed of titanium oxide and particles formed of alumina. The substrate is disk-shaped,
The phosphor wheel according to any one of claims 1 to 6, wherein the phosphor layer and the adhesive layer have a strip shape along a circumferential direction of the substrate. The phosphor wheel according to any one of claims 1 to 7,
An excitation light source;
An optical system that guides the emitted light from the excitation light source to the phosphor wheel.   A projection display apparatus comprising the light source device according to claim 8. Forming a light reflecting layer on one side of the substrate;
Forming a phosphor layer,
Forming an adhesive layer on the light reflecting layer;
By placing the molded phosphor layer on the adhesive layer, the molded phosphor layer is bonded and fixed to the light reflecting layer,
The method for manufacturing a phosphor wheel, wherein the adhesive layer includes particles having higher thermal conductivity than the base material of the adhesive layer, and has higher light reflectance than the light reflecting layer.

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