Phosphor wheel and projection-type image display device

Abstract

To provide a phosphor wheel capable of improving cooling efficiency, and a projection-type image display device including the same.SOLUTION: The phosphor wheel includes: a disk-shaped base plate; a phosphor ring that is arranged circularly or part of a circular on a first plane of the base plate; a motor that drives to rotate the base plate; multiple blade-shaped convexes that are arranged in rotation symmetrically on a second plane opposite the first plane of the base plate; and a circular cover that is placed at the opposite side of the convexes on the base plate to close-cover at least a part of the multiple convexes and rotates together with the base plate.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a phosphor wheel and a projection-type image display device including the same. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there exists a phosphor that receives strong light from a laser light source and performs wavelength conversion, in particular a phosphor wheel that rotates to dissipate heat, or a projection type image display device that uses the same.

[0003] With the advancement of solid-state light source technology, the light source of projection-type image display devices is gradually being replaced from conventional discharge tube lamps to LEDs or lasers, which have advantages such as long life, no mercury, and no risk of explosion. In particular, lasers have a small light output from a single unit, but the etendue of the light output is relatively small, so multiple lasers are unitized in an array and used as a light source, and high-output projectors with output exceeding 5,000 lumens are also being commercialized.

[0004] Lasers that emit blue wavelength light have excellent efficiency and output, and the mainstream configuration is to combine this with a phosphor that receives blue light and produces yellow light to obtain white light for illumination.

[0005] Projection-type image display devices equipped with solid-state light sources are also required to have higher output. However, even YAG-based devices, which have a relatively high conversion efficiency, can only use about half of the incident energy as light, and the rest becomes heat. If this heat is not removed, the phosphor temperature will rise, resulting in a decrease in the phosphor efficiency and reliability, so a cooling method must be used in combination.

[0006] Generally, a phosphor wheel is used that is made by forming the phosphor into an annular shape and rotating it with a motor, thereby expanding the effective surface area of ​​the phosphor even when the excitation light from the laser is focused into a point shape, and promoting heat exchange with the air. The following cooling methods have been proposed in the past.

[0007] For example, Patent Document 1 describes a second disk, Patent Document 2 shows that the heat source generated by receiving light is located outside the annular substrate and the wind generated by the rotating fan blades is directly received by the optical components to dissipate heat, and Patent Document 3 shows that multiple heat dissipation fins are provided on the back surface of the disk substrate. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 6689027 [Patent Document 2] JP 2003-156796 A [Patent Document 3] Patent No. 6696427 Summary of the Invention [Problem to be solved by the invention]

[0009] However, even if the second disk is provided in Patent Document 1, the cooling effect is not necessarily obtained, and actually forming and supporting the configuration of Patent Document 3 requires high strength and highly accurate processing, which makes it very expensive to realize. In recent years, there has been a demand for even higher brightness, and it has become necessary to provide a phosphor wheel equipped with an efficient cooling means.

[0010] An object of the present disclosure is to provide a phosphor wheel with improved cooling efficiency and a projection-type image display device including the same. [Means for solving the problem]

[0011] The phosphor wheel of the present disclosure comprises a disk-shaped substrate, a phosphor ring arranged in a ring shape or as part of a ring shape on a first surface of the substrate, a motor for driving and rotating the substrate, a plurality of blade-shaped protrusions arranged in rotational symmetry on a second surface of the substrate opposite the first surface, and an annular cover arranged on the opposite side of the substrate from the protrusions, tightly covering at least a portion of the plurality of protrusions, and rotating integrally with the substrate.

[0012] The projection type image display device according to the present disclosure comprises the above-mentioned phosphor wheel, a light source which irradiates light onto the phosphor wheel, a light modulation element which modulates illumination light including light from the phosphor wheel into image light, and a projection lens which projects the image light. Effect of the Invention

[0013] The present disclosure can provide a phosphor wheel with improved cooling efficiency and a projection-type image display device including the same. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram showing a configuration of an illumination device using a phosphor wheel according to a first embodiment; [Diagram 2] Front view of phosphor wheel [Diagram 3] Enlarged cross-sectional view of the end showing the structure around the phosphor [Figure 4] Rear perspective view of the phosphor wheel [Diagram 5] FIG. 2 is an exploded perspective view showing the relationship between the wheel base plate and the annular cover. [Figure 6A] FIG. 2 is a rear view of the phosphor wheel showing the state in which the wheel substrate and the annular cover are integrated together. [Figure 6B] Rear view of the phosphor wheel showing air flow through the blades [Figure 7A] FIG. 13 is an explanatory diagram showing the air flow around the heat dissipation blades in a comparative example. [Figure 7B] FIG. 1 is an explanatory diagram showing the air flow around the heat dissipation blades in each configuration. [Figure 7C] FIG. 1 is an explanatory diagram showing the air flow around the heat dissipation blades in each configuration. [Figure 8] FIG. 13 is an exploded perspective view showing the relationship between the wheel base plate and an annular cover having a different shape in a modified example. [Figure 9] FIG. 13 is a rear view showing a state in which the wheel base plate and an annular cover having a different shape are integrated together in a modified example. [Figure 10]FIG. 11 is an explanatory diagram showing the air flow around the heat dissipation blades in a modified example. [Figure 11] FIG. 13 is a side view showing a state in which the wheel base plate and an annular cover having a different shape are integrated together in a modified example. [Figure 12] FIG. 13 is a diagram showing a configuration of a projection type image display device using an illumination device according to a second embodiment; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, the embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed explanation than necessary may be omitted. For example, detailed explanation of already well-known matters or duplicate explanation of substantially the same configuration may be omitted. This is to avoid the following explanation becoming unnecessarily redundant and to facilitate understanding by those skilled in the art.

[0016] The embodiments of the present disclosure will be described with reference to the drawings. 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.

[0017] (Embodiment 1) [1-1. Description of lighting device 100] Hereinafter, a lighting device 100 using a phosphor wheel according to the first embodiment will be described with reference to Figures 1 to 7. In the following description, "image" includes "still image" and "moving image".

[0018] FIG. 1 is a diagram showing the configuration of lighting device 100 according to the first embodiment. FIG. 2 is a front view showing the front side of the phosphor wheel. FIG. 3 is an enlarged cross-sectional view of the end of the phosphor wheel. FIG. 4 is a perspective view of the phosphor wheel from the back. FIG. 5 is a diagram showing the relationship between the wheel substrate and the annular flat plate. FIG. 6 is a back view after integration. FIG. 7 is a diagram for explaining the air flow near the periphery of the heat dissipation fin in each configuration. In this specification, the front view is the direction in which light from light source 101 enters phosphor wheel 107, and the back view is the direction in which light is emitted from phosphor wheel 107 toward dichroic mirror 105.

[0019] Blue light emitted in the -X direction from light source 101, which includes multiple blue laser diodes for excitation light sources and collimating lenses paired with them, is converged and collimated by lenses 102 and 103 that constitute an afocal system, and enters diffuser 104. The blue laser light that enters diffuser 104 is diffused by diffuser 104, and then enters dichroic mirror 105. Dichroic mirror 105 has the property of reflecting blue light and transmitting other colored light.

[0020] Dichroic mirror 105 is disposed at an angle of 45 degrees with respect to the optical axis of the blue laser light from light source 101. The blue light from diffuser plate 104 is reflected by dichroic mirror 105, passes through condenser lens 106, and is collected on phosphor ring 109 arranged in an annular shape on wheel substrate 108 of phosphor wheel 107. Wheel substrate 108 is rotated by motor 110, so that even when the energy of the irradiated light is high, the incident area is expanded on the circumference of the phosphor related to the fluorescence, and heat generation during fluorescence can be suppressed.

[0021] Here, phosphor ring 109 has a characteristic of receiving blue light as excitation light and emitting yellow light. Yellow fluorescence (hereinafter referred to as "yellow light") from phosphor ring 109 is reflected by filler 112 (see FIG. 3) contained in adhesive layer 111 applied between phosphor ring 109 and wheel substrate 108, and is returned in the +Y direction. The yellow light traveling in the +Y direction passes through condenser lens 106 and then enters dichroic mirror 105 again. Since dichroic mirror 105 has a characteristic of transmitting colored light other than blue light, the incident yellow light passes through dichroic mirror 105 and proceeds in the +Y direction. The yellow light incident on lenses 113 and 114 is focused on the entrance surface of rod integrator 115, which has a rectangular opening and is arranged in front of it.

[0022] In this way, it is possible to generate yellow light from blue excitation light. In this configuration, the final output is the light emitted from rod integrator 115, and a necessary optical system is provided beyond the exit surface to perform the function. It is not necessary to use a rod integrator, and a lens array consisting of rectangular lenses can be used instead of lenses 113, 114 and rod integrator 115.

[0023] The configuration of the phosphor wheel 107 will be described in detail below. As described above, the phosphor ring 109 is arranged on one first surface 108a of the wheel substrate 108, on a circumference at a predetermined distance from the center of the wheel substrate 108, so that the center of the wheel substrate 108 and the center of the phosphor ring 109 are coaxial. Hereinafter, the first surface 108a of the wheel substrate 108 is also referred to as the surface of the wheel substrate 108.

[0024] The phosphor ring 109 is, for example, a ceramic made by baking a phosphor, and a phosphor that receives blue light and emits yellow light is used as the phosphor. As described above, the phosphor ring 109 is fixed onto the wheel substrate 108 by the adhesive layer 111. Filler 112 is kneaded into this adhesive layer 111 so that it is diffusely distributed. The filler 112 has a higher thermal conductivity than the material of the adhesive layer 111 and has higher light reflecting properties than the wheel substrate 108, and is, for example, titanium oxide.

[0025] On the other hand, the material of the wheel substrate 108 may be an aluminum alloy because of its thermal conductivity, availability, and workability. As a result, the phosphor in the phosphor ring 109 that receives the excitation light emits light without directionality, but the yellow light emitted toward the wheel substrate 108 is reflected by the filler 112 in the adhesive layer 111 before reaching the wheel substrate 108. The yellow light reflected by the filler 112 re-enters the phosphor ring 109, passes through the phosphor ring 109, and is emitted from the surface side of the phosphor ring 109. This makes it unnecessary to provide a reflective layer that was previously provided on the surface of the wheel substrate 108. When the wheel substrate 108 has a reflective layer formed by deposition or the like, the phosphor wheel 107 is very expensive, but according to the present disclosure, the reflective layer is unnecessary, so that the same performance can be achieved at a low cost.

[0026] In this embodiment, the filler 112 is exemplified as titanium oxide, but other materials can be used as long as they have excellent thermal conductivity and reflectance, and the same effect can be obtained with zinc oxide, for example. Also, although ceramic is exemplified as the phosphor of the phosphor ring 109, the same effect can be obtained by further applying an organic phosphor in which phosphor powder is mixed with a resin binder on top of titanium oxide applied to the wheel substrate 108.

[0027] A vane portion 118 is provided on a second surface 108b of the wheel substrate 108 opposite to the first surface 108a on which the phosphor ring 109 is arranged, and is arranged so as to overlap at least the area where the phosphor ring 109 is attached (see Figs. 3 and 7B). The vane portion 118 is configured by arranging a plurality of spiral vanes 118a at rotationally symmetric positions about the rotation axis of the wheel substrate 108. The inner and outer ends of the phosphor ring 109 are included between the inner and outer ends of the vane 118a.

[0028] The blade portion 118 increases the heat dissipation area, and as the wheel substrate 108 rotates, an air flow is generated from near the center of the phosphor wheel 107 toward the outer periphery of the wheel substrate 108, promoting heat exchange between the wheel substrate 108, the second surface 108b of the wheel substrate 108 opposite the surface on which the phosphor ring 109 is installed, the surface of the blades 118a, and the air.

[0029] Furthermore, in the present invention, an annular cover 121 is thermally bonded and fixed to the end surface 120 of the blade portion 118 opposite to the installation surface of the wheel substrate 108 and the phosphor ring 109. Specifically, the annular cover 121 is a metal material with good thermal conductivity such as thin aluminum, and can be realized by brazing or fixing it with a thermally conductive adhesive. The thicker the annular cover 121 is, the easier it is to handle the parts until it is fixed and conduct heat, but since it is installed near the outer periphery of the phosphor wheel 107, if the moment of inertia becomes large, a load is applied to the motor 110, and there is a concern that the desired rotation speed cannot be achieved and the reliability of the motor 110 cannot be guaranteed. Therefore, it is recommended to use a thin plate of aluminum material with good thermal conductivity and low specific gravity. The relationship is shown in Figures 4 and 5.

[0030] The following describes the dimensional relationship of this annular cover 121. If an outer diameter end 122 of the annular cover 121 is CDmax and an outer diameter end 123 (FIG. 2) of the phosphor ring 109 is PDmax, the two have the following relationship. PDmax≦CDmax···(1) formula

[0031] That is, the outer diameter of the annular cover 121 is equal to or greater than the outer diameter of the phosphor ring 109 .

[0032] Please refer to Fig. 6. Fig. 6 is a view further seen from the rear side on the motor side. If the diameter of the inner diameter side opening end 124 of the annular cover 121 is CDmin and the diameter of the inner diameter side opening end 125 (Fig. 2) of the phosphor ring 109 is PDmin, the two may have the following relationship. PDmin≦CDmin···(2) formula

[0033] This relationship is due to the fact that the temperature reduction effect is poor when CDmin, i.e., the inner diameter side of the annular cover 121, is smaller than the phosphor. Here, we will explain using Figures 7A-7C, which show schematic diagrams of the air flow involved in heat dissipation. Figures 7A-7C show the air flow during rotation in a cross section at a position corresponding to the AA part in Figure 6A.

[0034] Fig. 7A shows a comparative example with no annular cover 121, in which some air does not reach the outer periphery of the blades and escapes to the outside. Fig. 7B shows a case where an annular cover 121 with a small inner circumference is provided up to the inner periphery of the blades (PDmin>CDmin), in which the taken-in air does not escape, but stagnation occurs at the inlet where the air is taken in, hindering the overall flow.

[0035] Fig. 7C shows the case where the diameter CDmin of the inner diameter opening end 124 of the annular cover 121 is equivalent to the diameter dimension inside the phosphor (PDmin = CDmin), and it can be seen that the air escapes before stagnation occurs because the radial width of the annular cover 121 has been reduced. Incidentally, the expected phosphor temperature reduction effect was not significantly different between the conventional configuration of Fig. 7A and the configuration of Fig. 7B, in which the radial width of the annular cover is reduced, and the temperature reduction is 3 to 5% with the configuration of Fig. 7C.

[0036] As a modification of the first embodiment, a phosphor wheel 107A having an annular cover 126 of a different shape will be described with reference to Figures 8, 9, 10, and 11. Figure 8 is a diagram showing the relationship between the wheel substrate 108 and cover 126 of a different shape. Figure 9 is a rear view of the integrated phosphor wheel 107A with motor 110 omitted. Figure 10 shows the air flow during rotation in a cross section at a position corresponding to part BB in Figure 9. Figure 11 is a side view of phosphor wheel 107A.

[0037] Like the above-described annular cover 121, the annular cover 126 is also thermally coupled and fixed to the end surface 120 of the blade portion 118. As for the outer diameter of this annular cover 126, similarly to the annular cover 121, when the outer diameter 127 of the annular cover 126 is defined as CDmax and the outer diameter end 123 of the phosphor ring 109 is defined as PDmax, the following relationship is also established. PDmax≦CDmax···(3) formula

[0038] 8 and 9, an annular cover 126 has a standing bent portion 128 on its inner diameter side. CDB is the diameter of the base of the standing bent portion 128 on the inner diameter side from the flat plate portion 126a of the cover 126, i.e., the diameter of the boundary between the standing bent portion 128 bent on the inner diameter side and the flat plate portion 126a. CDT is the diameter of the tip of the standing bent portion 128 on the inner diameter side, and FDmin is the diameter of an imaginary circle 130 that is tangent to the inner diameter side ends of each of the multiple blades 118a, and FDmin is the diameter of the imaginary circle 130 that is tangent to the inner diameter side ends of each of the multiple blades 118a, so the following relationship holds: CDT≦FDmin≦CDB≦PDmin (4) formula

[0039] The air flow here is shown in FIG. 10. As shown in FIG. 10, it can be seen that even if the diameter CDT is smaller than the diameter FDmin, the air flows out smoothly. This is because the standing bent portion 128 is inclined toward the rear side, and even if the diameter CDT is equal to or smaller than the diameter FDmin, the standing bent portion 128 functions as a guide for the flow at the air intake portion. The annular cover 126 has a slightly larger radial width than the above-mentioned annular cover 121, and an aperture is also added, so the moment of inertia increases, but if the output of the motor 110 is allowed, the heat dissipation can be assisted over a wide area, and the cooling performance is also superior. In the phosphor wheel 107A of FIG. 10, a temperature reduction of 8 to 10% in the phosphor ring 109 is expected compared to the phosphor wheel of FIG. 7A, according to the simulation results.

[0040] In the above explanation, the phosphor ring 109 is a ceramic made by baking phosphor, but it is clear that the present invention is not limited to this and the same relationship can be applied to a coating type in which phosphor powder is mixed with a binder and then coated and hardened.

[0041] [1-2. Effects, etc.] The phosphor wheel 107 of the first embodiment comprises a disk-shaped wheel substrate 108, a phosphor ring 109 arranged in a ring shape or as part of a ring shape on a first surface 108a of the wheel substrate 108, a motor 110 that drives and rotates the wheel substrate 108, blades 118a as multiple blade-shaped protrusions arranged in rotational symmetry on a second surface 108b opposite the first surface 108a of the wheel substrate 108, and an annular cover 121 that is arranged on the opposite side of the wheel substrate 108 from the blades 118a, tightly covers at least a portion of the multiple blades 118a, and rotates integrally with the wheel substrate 108.

[0042] Phosphor wheel 107 is disposed on the side opposite to wheel substrate 108 of vanes 118a, and is provided with cover 121 that tightly covers at least a portion of vanes 118a, so that air flowing between adjacent vanes 118a can flow smoothly from the inner diameter side to the outer diameter side of cover 121, improving cooling efficiency. Also, it is possible to realize phosphor wheel 107 with a simple and inexpensive configuration that efficiently emits phosphor even under conditions of receiving high-power excitation light, while ensuring reliability.

[0043] The cover 126 also includes an annular flat portion 126a parallel to the wheel substrate 108, and an upright bent portion 128 serving as a guide portion that extends in the opposite direction to the wheel substrate 108 from the inner diameter portion of the flat portion 126a and is bent with an inclination toward the inner diameter side.

[0044] By providing the cover 126 with the upright bent portion 128, it is possible to generate a smooth air flow that flows from the inner diameter side of the blades 118a into spaces between adjacent blades 118a. In addition, since the upright bent portion 128 extends to the side opposite to the wheel substrate 108 side, it is possible to prevent a reduction in the amount of air flowing through the blade portion 118.

[0045] Furthermore, on the second surface 108b of the wheel substrate 108, the vanes 118a include a range corresponding to the position of the phosphor ring 109. Since the relationship CDB≦PDmin in formulas (3) and (4) holds, the vanes 118a extend to the same position in the radial direction as the phosphor ring 109 or to the inner diameter side and outer diameter side across the wheel substrate 108, so that heat generated from the phosphor ring 109 is easily transferred to the vanes 118a via the wheel substrate 108, and the cooling efficiency can be improved.

[0046] In addition, if the diameter of the boundary of upright bent portion 128 bent from flat portion 126a of cover 126 to the inner diameter side is defined as CDB, the diameter of the innermost diameter of upright bent portion 128 is defined as CDT, the diameter of the innermost diameter of phosphor ring 109 is defined as PDmin, and the diameter of the circle tangent to the inner diameter side of blade 118a is defined as FDmin, then the relationship CDT≦FDmin≦CDB≦PDmin holds.

[0047] Of the cover 121, the portion that is in close contact with or close to the blades 118a is made of an aluminum plate material. Since the portion of the cover 121 that is in close contact with or close to the blades 118a is made of an aluminum plate material, the heat transferred from the blades 118a to the cover 121 is excellently transferred uniformly within the cover 121, and the cooling efficiency can be improved. In addition, by using an aluminum plate material, which is one of the metals with excellent thermal conductivity, the weight of the cover 121 can be reduced, and the load on the motor 110 that rotates and drives the wheel substrate 108 can be reduced.

[0048] Also, the cover 121 is fixed by brazing to the end face 118ab of the blade 118a on the side opposite to the wheel substrate 108. This allows the blade 118a and the cover 121 to be in close contact with each other, so that the air that enters from the inner diameter side of the blade 118a can pass through to the outer diameter side without leaking on the way, improving the cooling efficiency. Furthermore, the brazing improves the thermal conductivity from the blade 118a to the annular cover 121, so that the cover 121 can function as a heat sink, further improving the cooling efficiency.

[0049] Also, the cover 121 may be adhesively fixed to the end surface 118ab of the blade 118a on the side opposite to the wheel substrate 108. This allows the blade 118a and the cover 121 to be in close contact with each other, so that the air entering from the inner diameter side of the blade 118a can pass through to the outer diameter side without leaking on the way, thereby improving the cooling efficiency.

[0050] In addition, an adhesive layer 111 is provided between the wheel substrate 108 and the phosphor ring 109, and bonds the wheel substrate 108 and the phosphor ring 109. This allows the phosphor ring 109 to be reliably fixed to the wheel substrate 108.

[0051] Furthermore, since the adhesive layer 111 contains the filler 112 containing titanium oxide, it is possible to reflect yellow light traveling toward the wheel substrate 108, making it possible to omit a reflective layer.

[0052] (Embodiment 2) [2-1. Description of the projection type image display device] Hereinafter, the configuration of a projection-type image display device 200 equipped with the illumination device 100 of the embodiment 1 shown in Fig. 1 will be described with reference to Fig. 12. Here, illumination device 201 further comprises a blue light optical system in addition to the illumination device 100 of the embodiment 1. In Fig. 12, the same reference numerals are used for components that are the same as those in illumination device 100. The configuration of illumination device 100 is the same as in embodiment 1, so a description thereof will be omitted.

[0053] The illumination device 201 includes the illumination device 100 , a light source 202 , a lens 203 , a lens 204 , a diffusion plate 205 , a mirror 206 , and a dichroic mirror 207 .

[0054] Blue light emitted in the +X direction from light source 202, which is equipped with multiple blue laser diodes and collimating lenses paired with them, is converged and collimated by lenses 203 and 204 that constitute an afocal system, but is incident on diffuser 205 near the convergence position, whereby the intensity distribution is converted to be nearly smooth to a certain extent, and the light is incident on mirror 206 and dichroic mirror 207. Dichroic mirror 207 has the property of reflecting blue light and transmitting other colored light.

[0055] Dichroic mirror 207 causes the yellow light and the blue light that have been transmitted through dichroic mirror 105 to be superimposed on the same optical axis. In this way, the light incident on lens 113 becomes yellow light and blue light, passes through lens 114 and rod integrator 115, and enters relay optical system 208.

[0056] The light emitted from rod integrator 115 passes through relay lenses 209 and 210 as illumination light, is reflected by return mirror 211, passes through field lens 212, and enters total reflection prism 213. Total reflection prism 213 is composed of first prism 214 and second prism 215 fixed with a small gap (air gap) maintained between them. The light entering total reflection prism 213 is totally reflected by surface 216, and then enters color prism unit 218 via surface 217.

[0057] This color prism unit 218 is composed of a first prism 220 having a blue-transmitting dichroic mirror surface 219 that has the property of reflecting blue light, a second prism 222 having a green-transmitting dichroic mirror surface 221 that has the property of reflecting red light and blue light, and a third prism 223 bonded together. However, an air gap is provided between the first prism 220 and the second prism 222 in order to utilize total reflection.

[0058] As shown in the figure, DMDs 224R, 224G, and 224B are provided on the end faces of each prism. These DMDs are equipped with multiple tiny mirrors arranged two-dimensionally, and the tilt direction of each mirror is controlled in two directions according to an external video signal. When the tilt angle is for an ON signal, the reflected light returns to color prism unit 218 as image light at an incident angle of 0°, and when the tilt angle is for an OFF signal, the reflected light is incident again on color prism unit 218 at a large angle as unwanted light. DMD 224B is a blue light modulation element, DMD 224R is a red light modulation element, and DMD 224G is a green light modulation element.

[0059] In DMDs 224R, 224G, and 224B, pixels in the white display mode return to color prism unit 218, and then pass through second prism 215 and first prism 214 of total reflection prism 213, enter projection lens 225, and reach a screen not shown in Fig. 12. Therefore, color display can be achieved by inputting different signals to DMDs 224R, 224G, and 224B.

[0060] Although a configuration using three DMDs is shown in Fig. 12, it is also possible to use a three-panel LCD configuration using blue and yellow light and LCD panels for modulating blue, green, and red.Furthermore, it is also possible to use a single-panel configuration in which phosphors with different characteristics are arranged to change the color light emitted over time, and the signal that drives one DMD is switched according to the illumination timing of that color to obtain a color display on the screen.

[0061] [2-2. Effects, etc.] As described above, the projection type image display device 200 of embodiment 2 comprises phosphor wheel 107, light source 101 that irradiates light onto phosphor wheel 107, DMDs 224R, 224G, 224B that modulate illumination light including light from phosphor wheel 107 into image light, and projection lens 225 that projects the image light.

[0062] By using phosphor wheel 107 with improved cooling efficiency, it is possible to generate light with a higher brightness as illumination light, thereby providing a high-output, high-reliability projection-type image display device 200 with improved brightness of the projected image.

[0063] As described above, the embodiments have been described as examples of the technology disclosed in this application. However, the technology in this disclosure is not limited to these, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made. In addition, it is also possible to combine the components described in the above embodiments to create new embodiments.

[0064] (Outline of the embodiment) (1) The phosphor wheel of the present disclosure comprises a disk-shaped substrate, a phosphor ring arranged in a ring shape or as part of a ring shape on a first surface of the substrate, a motor for driving the substrate to rotate, a plurality of blade-shaped protrusions arranged in rotational symmetry on a second surface of the substrate opposite the first surface, and an annular cover arranged on the opposite side of the substrate from the protrusions, covering at least a portion of the plurality of protrusions, and rotating integrally with the substrate.

[0065] The phosphor wheel is arranged on the opposite side of the substrate from the convex portions and is provided with a cover 121 that covers at least a portion of the multiple convex portions, so that air flowing between adjacent blades 118a can flow smoothly from the inner diameter side to the outer diameter side of cover 121, improving cooling efficiency.

[0066] (2) In the phosphor wheel of (1), the cover has an annular flat portion parallel to the substrate, and a guide portion extending from the inner diameter portion of the flat portion toward the opposite side to the substrate and bent up with an inclination toward the inner diameter side.

[0067] (3) In the phosphor wheel of (1) or (2), the convex portion includes an area on the second surface of the substrate that corresponds to the position of the phosphor ring.

[0068] (4) In the phosphor wheel of (2), if the diameter of the boundary between the flat portion of the cover and the guide portion bent inwardly from the inner diameter side is CDB, the diameter of the innermost diameter of the bent portion is CDT, the diameter of the innermost diameter of the phosphor ring is PDmin, and the diameter touching the convex portion is FDmin, then the relationship is CDT≦FDmin≦CDB≦PDmin.

[0069] (5) In any one of the phosphor wheels (1) to (4), the portion of the cover that is in contact with or adjacent to the protruding portion is made of an aluminum plate.

[0070] (6) In the phosphor wheel according to any one of (1) to (5), the cover is fixed by brazing to the portion of the substrate opposite the protrusion.

[0071] (7) In any one of the phosphor wheels (1) to (5), the cover is adhesively fixed to the portion of the substrate opposite the protrusion.

[0072] (8) In any one of the phosphor wheels (1) to (7), an adhesive layer is provided between the substrate and the phosphor ring to bond the substrate and the phosphor ring.

[0073] In the phosphor wheel of (9)(8), the adhesive layer contains particles containing titanium oxide.

[0074] (10) A projection type image display device according to the present disclosure includes a phosphor wheel selected from any one of (1) to (9), a light source that irradiates the phosphor wheel with light, a light modulation element that modulates illumination light including light from the phosphor wheel into image light, and a projection lens that projects the image light.

[0075] By using a phosphor wheel with improved cooling efficiency, it is possible to generate light with a higher brightness as illumination light, thereby providing a projection-type image display device with improved brightness of the projected images. [Industrial Applicability]

[0076] The present disclosure is applicable to an illumination device using a phosphor wheel, and a projection-type image display device using the same. [Explanation of symbols]

[0077] 1 Projection type image display device 100, 201 Lighting equipment 101, 202 light source 102, 103, 203, 204 Afocal lenses 104, 205 Diffuser 105, 207 Dichroic mirror 106 Condenser Lens 107, 107A Phosphor Wheel 108 Wheel Board 109 Phosphor Ring 110 Motor 111 Adhesive layer 112 Filler 113, 114 Lenses 115 Rod Integrator 118 Wing 119 Back side of board 120 Blade end face 121 Cover 122 Outer diameter end of cover 123 Outer diameter end of phosphor ring 124 Inner diameter opening end of cover 125 Inner diameter opening end of phosphor ring 126 Alternative cover 127 Outside diameter of cover of different shape 128 Vertical bend 206, 211 Mirror 208 Relay Optical System 209, 210 Relay lens 212 Field Lens 213 Total Reflection Prism 214 First prism of a total reflection prism 215 Second prism of a total reflection prism 216 Total reflection surface 217 Total reflection prism facing color prism unit 218 Color Prism Unit 219 Blue transmission dichroic mirror surface 220 First Prism of Color Prism Unit 221 Green transmission dichroic mirror surface 222 Second Prism of Color Prism Unit 223 Third Prism of Color Prism Unit 224R, 224G, 224B DMD 225 Projection Lens

Claims

1. A disk-shaped substrate; a phosphor ring disposed annularly or as part of an annular shape on a first surface of the substrate; A motor that rotates the substrate; a plurality of wing-shaped protrusions arranged in a rotational symmetry on a second surface of the substrate opposite to the first surface; an annular cover that is disposed on the opposite side of the protrusions from the substrate, that closely covers at least a portion of the protrusions, and that rotates integrally with the substrate; Phosphor wheel.

2. The cover is An annular flat plate portion parallel to the substrate; a guide portion extending on an inner diameter portion of the flat plate portion toward the opposite side to the substrate and bent upright with an inclination toward the inner diameter side; The phosphor wheel of claim 1 .

3. The second surface of the substrate includes a range corresponding to the position of the phosphor ring. The phosphor wheel of claim 1 .

4. A diameter of a boundary of the guide portion bent from the flat portion of the cover to the inner diameter side is defined as CDB, and a diameter of an innermost diameter of the bent portion is defined as CDT. The innermost diameter of the phosphor ring is defined as PDmin, If the diameter of a virtual circle tangent to the convex portion is FDmin, The relationship is CDT≦FDmin≦CDB≦PDmin. The phosphor wheel of claim 2 .

5. The portion of the cover that is in close contact with or adjacent to the protruding portion is made of an aluminum plate material. The phosphor wheel of claim 1 .

6. The cover is fixed by brazing to a portion of the substrate opposite to the protrusion. The phosphor wheel of claim 1 .

7. the cover is adhesively fixed to a portion of the substrate opposite to the protrusion; The phosphor wheel of claim 1 .

8. an adhesive layer is provided between the substrate and the phosphor ring to bond the substrate and the phosphor ring; The phosphor wheel of claim 1 .

9. The adhesive layer contains particles containing titanium oxide. The phosphor wheel of claim 8.

10. A phosphor wheel according to any one of claims 1 to 9; a light source that irradiates the phosphor wheel with light; a light modulation element that modulates illumination light including light from the phosphor wheel into image light; A projection lens that projects the image light. Projection type image display device.

Images