Wavelength conversion device, light source device, and projector

Abstract

The present invention provides a wavelength conversion device, a light source device, and a projector, which can suppress the enlargement of the device structure and improve the wavelength conversion efficiency of the phosphor layer by efficiently cooling the phosphor layer, thereby generating bright fluorescence. The wavelength conversion device of the present invention includes: a rotation driving unit; a wheel substrate; a phosphor layer formed on a first surface of the wheel substrate; and a cooling fin unit provided on a second surface of the wheel substrate. The cooling fin unit has a base portion joined to the wheel substrate and a plurality of heat dissipation fins. The second surface of the wheel substrate includes a first region corresponding to the phosphor layer and a second region closer to the central axis side than the first region. The second surface of the wheel substrate is separated from the wheel substrate side surface of the base portion, whereby a space is formed between the wheel substrate and the base portion, and a connecting portion for thermally connecting the second surface of the wheel substrate and the wheel substrate side surface of the base portion is disposed at least in the second region of the second surface.

Description

Technical Field

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

[0002] In recent years, as a light source device used in a projector, there has been a technique of irradiating excitation light emitted from a laser light source onto a phosphor layer and using fluorescence obtained by wavelength conversion in the phosphor layer as illumination light. In order to generate high-brightness illumination light, it is necessary to increase the output of the laser light source. However, if the output of the excitation light irradiated onto the phosphor layer is increased, the wavelength conversion efficiency of the phosphor layer will decrease due to temperature rise.

[0003] Therefore, as disclosed in Patent Documents 1 and 2 below, by using a fluorescent wheel having a phosphor layer formed on a rotatable wheel, the phosphor layer is cooled by the rotation of the fluorescent wheel, thereby improving the wavelength conversion efficiency.

[0004] In the light source device disclosed in Patent Document 1 above, a space for sealing the wheel substrate is formed, and heat is transmitted through the space to the heat sink of the housing disposed opposite to the heat sink of the wheel substrate, thereby dissipating heat from the phosphor layer.

[0005] In addition, in the light source device disclosed in Patent Document 2 above, on the back surface opposite to the front surface of the wheel substrate on which the phosphor layer is formed, a heat sink is provided at a position inside the phosphor formation region. Thus, the heat sink rotates together with the wheel substrate, and air is sent to the phosphor layer formation region by the heat sink to dissipate heat from the phosphor layer.

[0006] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2020-201387

[0007] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2016-66061

[0008] However, in the light source device disclosed in Patent Document 1 above, when heat is transmitted through the space to the heat sink on the housing side, since the heat sink on the housing side has a non-rotating structure, it is difficult to sufficiently dissipate heat from the phosphor layer.

[0009] In addition, in the light source device disclosed in Patent Document 2 above, the heat of the phosphor layer is concentrated at a position outside the heat sink. Therefore, in order to obtain sufficient cooling performance, it is necessary to increase the rotation speed of the heat sink, resulting in a problem that the structure becomes large due to the enlargement of the drive source for rotating the wheel substrate.

[0010] In addition, when the laser light source is made to have a higher output in order to generate illumination light with higher brightness, increasing the size of the heat sink is considered to improve the cooling performance of the phosphor layer. However, if the size of the heat sink is increased, the weight of the heat sink increases, and thus a large driving source is required as a driving source for rotating the fluorescent wheel, resulting in problems such as an increase in the size of the device structure and an increase in weight.

[0011] Therefore, it is desirable to provide a new technology that can suppress an increase in the size of the device structure and can improve the wavelength conversion efficiency of the phosphor layer by efficiently cooling the phosphor layer, thereby generating bright fluorescence. Summary of the Invention

[0012] To solve the above problems, according to a first aspect of the present invention, a wavelength conversion device includes: a rotation driving unit; a wheel substrate having thermal conductivity and rotated about a central axis by the rotation driving unit; a phosphor layer formed around the central axis on a first surface of the wheel substrate; and a cooling fin unit provided on a second surface of the wheel substrate opposite to the first surface. The cooling fin unit has a base portion joined to the wheel substrate and a plurality of heat sinks provided on a side of the base portion opposite to the wheel substrate side. The second surface of the wheel substrate includes a first region corresponding to the phosphor layer and a second region closer to the central axis side than the first region. The second surface of the wheel substrate is separated from a surface of the base portion on the wheel substrate side, thereby forming a space between the wheel substrate and the base portion. A connecting portion that thermally connects the second surface of the wheel substrate and the surface of the base portion on the wheel substrate side is disposed at least in the second region of the second surface.

[0013] According to a second aspect of the present invention, a light source device includes: the wavelength conversion device according to the above aspect; and an excitation light source that emits excitation light toward the wavelength conversion device.

[0014] According to a third aspect of the present invention, a projector includes: the light source device according to the above aspect; a light modulation device that modulates light from the light source device according to image information; and a projection optical device that projects the light modulated by the light modulation device. Brief Description of the Drawings

[0015] Figure 1 is a schematic configuration diagram of a projector according to an embodiment.

[0016] Figure 2 is a schematic configuration diagram showing a light source device according to an embodiment.

[0017] Figure 3 is an exploded perspective view showing a schematic configuration of a wavelength conversion device.

[0018] Figure 4A This is a view of the wavelength conversion device as seen from the back side of the base portion.

[0019] Figure 4B This is a top view of the wavelength conversion device as seen from the wheel substrate side.

[0020] Figure 5 This is a cross-sectional view of the wavelength conversion device.

[0021] Figure 6 This is an exploded perspective view of the wavelength conversion device according to the second embodiment.

[0022] Figure 7 This is a view showing the operation of the wavelength conversion device.

[0023] Figure 8 This is an exploded perspective view of the wavelength conversion device according to the third embodiment.

[0024] Figure 9 This is a cross-sectional view of the wavelength conversion device.

[0025] Figure 10 This is a top view of the wavelength conversion device according to the first modification as seen from the wheel substrate side.

[0026] Figure 11 This is an exploded perspective view of the wavelength conversion device according to the second modification as seen from the wheel substrate side.

[0027] Reference Numeral Explanation

[0028] 1: Projector; 2: Light source device; 4B, 4G, 4R: Light modulation device; 20, 120, 220, 220A: Wavelength conversion device; 21: Rotation drive unit; 22: Wheel substrate; 23: Phosphor layer; 24, 124: Cooling fin unit; 30: Base portion; 31: Heat sink; 33: Solder; 35, 135: Connection portion; 36: Columnar body; 36a: First columnar body group; 36am: First columnar body; 36b: Second columnar body group; 36bm: Second columnar body; 37, 38: Annular body; 40: First light source (excitation light source); 70, 170: Thermal diffusion auxiliary member; 121: Opening portion (air inflow portion); 130a: Outer peripheral opening portion (air outflow portion); 136: Rod-shaped body; 700: Evaporation portion; 701: Condensation portion; 705: Housing; E: Excitation light; H: Heat; O: Central axis; R1: Outer region (first region); R2: Inner region (second region); S, S1: Space; Y: Fluorescence. Detailed Description of the Embodiment

[0029] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0030] In addition, in the drawings used in the following description, in order to facilitate understanding of the features, the feature portions are sometimes enlarged for convenience, and the dimensional ratios of the respective structural elements are not necessarily the same as the actual ones.

[0031] (First Embodiment)

[0032] Figure 1 is a schematic structural diagram of the projector of the present embodiment.

[0033] As Figure 1 shown, the projector 1 of the present embodiment is a projection type image display device that displays an image on the screen SCR. The projector 1 includes a light source device 2, a color separation optical system 3, a light modulation device 4R, a light modulation device 4G, a light modulation device 4B, a synthesis optical system 5, and a projection optical device 6.

[0034] The light source device 2 emits white illumination light WL toward the color separation optical system 3. The structure of the light source device 2 will be described in detail later.

[0035] The color separation optical system 3 separates the illumination light WL emitted from the light source device 2 into red light LR, green light LG, and blue light LB. The color separation optical system 3 includes a first dichroic mirror 7a, a second dichroic mirror 7b, a first total reflection mirror 8a, a second total reflection mirror 8b, a third total reflection mirror 8c, a first relay lens 9a, and a second relay lens 9b.

[0036] The first dichroic mirror 7a separates the illumination light WL from the illumination device 2 into light including red light LR, green light LG, and blue light LB. The first dichroic mirror 7a transmits the red light LR and reflects the light including the green light LG and the blue light LB. On the other hand, the second dichroic mirror 7b reflects the green light LG and transmits the blue light LB. Thus, the second dichroic mirror 7b separates the light including the green light LG and the blue light LB into the green light LG and the blue light LB.

[0037] The first total reflection mirror 8a is disposed in the optical path of the red light LR and reflects the red light LR that has passed through the first dichroic mirror 7a toward the light modulation device 4R. On the other hand, the second total reflection mirror 8b and the third total reflection mirror 8c are disposed in the optical path of the blue light LB and guide the blue light LB that has passed through the second dichroic mirror 7b to the light modulation device 4B. The green light LG is reflected from the second dichroic mirror 7b toward the light modulation device 4G.

[0038] The first relay lens 9a and the second relay lens 9b are disposed on the light emission side of the second dichroic mirror 7b in the optical path of the blue light LB. The first relay lens 9a and the second relay lens 9b compensate for the light loss of the blue light LB caused by the longer optical path length of the blue light LB than the optical path lengths of the red light LR and the green light LG.

[0039] The light modulation device 4R modulates the red light LR according to the image information to form image light corresponding to the red light LR. The light modulation device 4G modulates the green light LG according to the image information to form image light corresponding to the green light LG. The light modulation device 4B modulates the blue light LB according to the image information to form image light corresponding to the blue light LB.

[0040] The light modulation device 4R, the light modulation device 4G, and the light modulation device 4B respectively use transmissive liquid crystal panels, for example. In addition, polarizing plates (not shown) are respectively arranged on the incident side and the emission side of the liquid crystal panel.

[0041] A field lens 10R is arranged on the incident side of the light modulation device 4R. The field lens 10R makes the incident red light LR parallel. A field lens 10G is arranged on the incident side of the light modulation device 4G. The field lens 10G makes the incident green light LG parallel. A field lens 10B is arranged on the incident side of the light modulation device 4B. The field lens 10B makes the incident blue light LB parallel.

[0042] The image light emitted from the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B is incident on the combining optical system 5. The combining optical system 5 combines the image light corresponding to the red light LR, the green light LG, and the blue light LB respectively, and emits the combined image light toward the projection optical device 6. The combining optical system 5 uses a cross dichroic prism, for example.

[0043] The projection optical device 6 has a plurality of projection lenses. The projection optical device 6 magnifies and projects the image light combined by the combining optical system 5 toward the screen SCR. Thereby, an enlarged image is displayed on the screen SCR.

[0044] Hereinafter, the structure of the light source device 2 will be described.

[0045] Figure 2 It is a schematic structural diagram of the light source device 2 of the present embodiment.

[0046] As Figure 2 shown, the light source device 2 has a first light source 40 as an excitation light source, a collimating optical system 41, a dichroic mirror 42, a collimating and condensing optical system 43, a wavelength conversion device 20, a second light source 44, a condensing optical system 45, a diffusion plate 46, and a collimating optical system 47.

[0047] The first light source 40 is composed of a semiconductor laser 40a that emits blue pump light E composed of a laser. The peak luminous intensity of the pump light E is, for example, 445 nm. In addition, as the semiconductor laser 40a, a semiconductor laser that emits blue light with a wavelength other than 445 nm (for example, 455 nm, 460 nm) can also be used. The optical axis ax of the first light source 40 is perpendicular to the illumination optical axis 100ax of the light source device 2. In addition, the first light source 40 may be configured such that a plurality of semiconductor lasers 40a are arranged in an array in a plane perpendicular to the optical axis ax of the first light source 40.

[0048] The collimating optical system 41 includes a first lens 41a and a second lens 41b. The collimating optical system 41 makes the light emitted from the first light source 40 substantially parallel. The first lens 41a and the second lens 41b are each composed of a convex lens.

[0049] The dichroic mirror 42 is disposed in the optical path between the collimating optical system 41 and the collimating and condensing optical system 43 at an orientation that intersects the optical axis ax of the first light source 40 and the illumination optical axis 100ax at an angle of 45° respectively. The dichroic mirror 42 reflects the blue light component and transmits the red light component and the green light component. Therefore, the dichroic mirror 42 reflects the pump light E and the blue light B described later and transmits the yellow fluorescence Y.

[0050] The collimating and condensing optical system 43 converges the pump light E that has passed through the dichroic mirror 42 and makes it incident on the wavelength conversion device 20, and makes the fluorescence Y emitted from the wavelength conversion device 20 substantially parallel. The collimating and condensing optical system 43 includes a first lens 43a and a second lens 43b. The first lens 43a and the second lens 43b are each composed of a convex lens.

[0051] The second light source 44 is composed of a semiconductor laser having the same wavelength band as that of the first light source 40. The second light source 44 may be composed of one semiconductor laser or a plurality of semiconductor lasers. In addition, the second light source 44 may be composed of a semiconductor laser having a wavelength band different from that of the semiconductor laser of the first light source 40.

[0052] The condensing optical system 45 includes a first lens 45a and a second lens 45b. The condensing optical system 45 converges the blue light B emitted from the second light source 44 on or near the diffusion surface of the diffusion plate 46. The first lens 45a and the second lens 45b are each composed of a convex lens.

[0053] The diffusion plate 46 diffuses the blue light B emitted from the second light source 44 and generates blue light B having a light distribution similar to the light distribution of the fluorescence Y emitted from the wavelength conversion device 20. As the diffusion plate 46, for example, ground glass made of optical glass can be used.

[0054] The collimating optical system 47 includes a first lens 47a and a second lens 47b. The collimating optical system 47 makes the light emitted from the diffusion plate 46 substantially parallel. The first lens 47a and the second lens 47b are each formed of a convex lens.

[0055] The blue light B emitted from the second light source 44 is reflected by the dichroic mirror 42, and is combined with the fluorescence Y emitted from the wavelength conversion device 20 and transmitted through the dichroic mirror 42 to generate white illumination light WL. The illumination light WL is incident on the uniform illumination optical system 80.

[0056] The uniform illumination optical system 80 includes a first lens array 81, a second lens array 82, a polarization conversion element 83, and a superposition lens 84.

[0057] The first lens array 81 includes a plurality of first lenses 81a for dividing the illumination light WL from the light source device 2 into a plurality of partial light beams. The plurality of first lenses 81a are arranged in a matrix in a plane perpendicular to the illumination optical axis 100ax.

[0058] The second lens array 82 includes a plurality of second lenses 82a corresponding to the plurality of first lenses 81a of the first lens array 81. The plurality of second lenses 82a are arranged in a matrix in a plane perpendicular to the illumination optical axis 100ax.

[0059] The second lens array 82 and the superposition lens 84 image the images of the respective first lenses 81a of the first lens array 81 near the image formation regions of the light modulation devices 4R, 4G, and 4B, respectively.

[0060] The polarization conversion element 83 converts the light emitted from the second lens array 82 into linearly polarized light in one direction. The polarization conversion element 83 includes, for example, a polarization separation film and a retardation plate (not shown).

[0061] The superposition lens 84 converges the respective partial light beams emitted from the polarization conversion element 83 and overlaps them near the image formation regions of the light modulation devices 4R, 4G, and 4B, respectively.

[0062] Next, the structure of the wavelength conversion device 20 will be described.

[0063] Figure 3 is an exploded perspective view showing a schematic structure of the wavelength conversion device 20.

[0064] As Figure 3 shown, the wavelength conversion device 20 of the present embodiment includes a rotation driving unit 21 and a rotating body 29. The rotating body 29 includes a wheel substrate 22, a phosphor layer 23, and a cooling fin unit 24.

[0065] The phosphor layer 23 generates heat when the fluorescent Y emits light. When the temperature of the phosphor layer 23 is too high, the wavelength conversion efficiency of the fluorescent Y decreases, and the amount of light emitted by the fluorescent Y may decrease. In the wavelength conversion device 20 of the present embodiment, as described later, by efficiently cooling the phosphor layer 23, the decrease in the fluorescence conversion efficiency due to the increase in the temperature of the phosphor layer 23 is suppressed.

[0066] The rotation driving unit 21 is composed of a motor device. The rotation driving unit 21 has a rotation support portion 21a that can rotate about a central axis O as an imaginary axis. The rotation support portion 21a supports the cooling fin unit 24 so that it can rotate. An opening 24b for inserting the shaft portion 21b of the rotation support portion 21a is provided in the cooling fin unit 24.

[0067] The cooling fin unit 24 rotates about the central axis O by being supported by the rotation driving unit 21. The cooling fin unit 24 is supported by the rotation support portion 21a of the rotation driving unit 21 via screw members 19.

[0068] In the following description, the radial direction with respect to the central axis O is simply referred to as the "radial direction". The direction away from the central axis O in the radial direction is called the "radial outer side", and the direction approaching the central axis O in the radial direction is called the "radial inner side". The circumferential direction about the central axis O is simply referred to as the "circumferential direction".

[0069] The wheel substrate 22 has a front surface 22a as the first surface and a back surface 22b on the opposite side of the front surface 22a. The back surface 22b of the wheel substrate 22 is connected to the cooling fin unit 24. The wheel substrate 22 is made of, for example, a circular metal plate such as aluminum or copper with excellent heat dissipation properties. That is, in the present embodiment, the wheel substrate 22 has thermal conductivity.

[0070] The phosphor layer 23 is formed in a circular ring shape around the central axis O on the front surface 22a of the wheel substrate 22. That is, the phosphor layer 23 is arranged in a ring shape around the central axis O. The phosphor layer 23 is disposed on the outer peripheral side of the front surface 22a of the wheel substrate 22.

[0071] Based on such a structure, the rotating body 29 including the wheel substrate 22, the phosphor layer 23, and the cooling fin unit 24 can rotate about the central axis O by the rotation driving unit 21.

[0072] As Figure 2 shown, the phosphor layer 23 is excited by the excitation light E incident from the upper surface 23a, and yellow fluorescence Y including red light and green light is emitted from the upper surface 23a. The phosphor layer 23 uses, for example, YAG:Ce in which cerium ions (for example, Ce3 12 ) are added to a garnet crystal (YAG) of Y3Al5O + ). In addition, appropriate scattering elements (not shown) may be included in the phosphor layer 23.

[0073] In this embodiment, a reflecting member 25 is provided between the back surface 23b of the phosphor layer 23 and the front surface 22a of the wheel substrate 22. The reflecting member 25 reflects the light emitted from the back surface 23b of the phosphor layer 23 toward the upper surface 23a side.

[0074] As Figure 3 shown, the cooling fin unit 24 has a base portion 30 and a plurality of cooling fins 31. The base portion 30 is joined to the wheel substrate 22. The base portion 30 is formed of, for example, a circular plate made of a metal such as aluminum or copper with excellent heat dissipation properties. The base portion 30 has the same outer shape as the wheel substrate 22.

[0075] The base portion 30 has a front surface 30a and a back surface 30b. The front surface 30a of the base portion 30 is the surface facing the wheel substrate 22, that is, the "surface on the wheel substrate 22 side". The back surface 30b of the base portion 30 is the surface facing the opposite direction to the front surface 30a and is mounted on the rotary support portion 21a of the rotary drive portion 21.

[0076] Figure 4A is a view of the wavelength conversion device 20 as viewed from the back surface 30b side of the base portion 30.

[0077] As Figure 4A shown, a plurality of cooling fins 31 are provided on the back surface 30b of the base portion 30. That is, a plurality of cooling fins 31 are provided on the side of the base portion 30 opposite to the wheel substrate 22 side. In this embodiment, the plurality of cooling fins 31 are formed integrally with the base portion 30. The plurality of cooling fins 31 are located radially outside the rotary drive portion 21 and extend radially toward the outer edge side of the base portion 30. Each cooling fin 31 is bent in an arcuate shape and is formed to extend in an inclined direction with respect to the outer edge normal of the base portion 30.

[0078] Based on such a structure, the cooling fin unit 24 rotates the plurality of cooling fins 31 together with the base portion 30 about the central axis O, and on the back surface 30b side of the base portion 30, the air sucked from the radially inner side (central axis O side) is caused to generate a wind flowing toward the radially outer side along the cooling fins 31 by centrifugal force. In the case of this embodiment, the wind generated by the cooling fins 31 is also used to cool the rotary drive portion 21 mounted at the central portion of the base portion 30.

[0079] In addition, regardless of the shape of the cooling fins 31 and the rotation direction of the base portion 30, the cooling fin unit 24 generates an air flow from the radially inner side of the base portion 30 toward the radially outer side.

[0080] Figure 4B is a top view of the wavelength conversion device 20 as viewed from the wheel substrate 22 side. In addition, for ease of viewing the drawing, Figure 4B it is illustrated in a state where a part of the wheel substrate 22 is cut away.

[0081] Figure 5 This is a cross-sectional view of the wavelength conversion device 20.

[0082] As Figure 5 shown, the reverse side 22b of the wheel substrate 22 includes an outer region R1 as the first region and an inner region R2 as the second region. In Figure 5 order to make the drawings easy to observe, reference numerals indicating the outer region R1 and the inner region R2 are shown on the upper side of the wheel substrate 22.

[0083] The outer region R1 is a region corresponding to the phosphor layer 23. The inner region R2 is a region located closer to the central axis O side than the outer region R1.

[0084] In the present embodiment, the outer region R1 corresponds to a region that overlaps the outer shape of the phosphor layer 23 formed on the front side 22a of the wheel substrate 22 in a plane. In addition, the outer region R1 does not need to be exactly the same as the outer shape of the phosphor layer 23, and it is sufficient to have an area similar to the outer shape of the phosphor layer 23.

[0085] The wavelength conversion device 20 of the present embodiment further includes a connecting portion 35 that thermally connects the reverse side 22b of the wheel substrate 22 to the front side 30a of the base portion 30. The connecting portion 35 is disposed at least in the inner region R2 of the reverse side 22b of the wheel substrate 22. In the case of the present embodiment, the connecting portion 35 is disposed over the entire reverse side 22b including the inner region R2 and the outer region R1.

[0086] Here, thermally connecting the reverse side 22b to the front side 30a by the connecting portion 35 means that the reverse side 22b and the front side 30a are directly or indirectly connected in a state where heat can be transferred between them via the connecting portion 35. That is, the connecting portion 35 can be directly joined to the reverse side 22b or the front side 30a without sandwiching other components, or other components such as an adhesive material can be sandwiched between the connecting portion 35 and the reverse side 22b or the front side 30a.

[0087] By thermally connecting the wheel substrate 22 to the base portion 30 using the connecting portion 35, the wavelength conversion device 20 of the present embodiment can efficiently transfer heat from the wheel substrate 22 to the base portion 30 via the connecting portion 35.

[0088] As Figure 5 shown, in the case of the present embodiment, the connecting portion 35 is integrally formed with the base portion 30. That is, the connecting portion 35 is formed to protrude from the front side 30a of the base portion 30 toward the wheel substrate 22 side. In the present embodiment, the connecting portion 35 is joined to the reverse side 22b of the wheel substrate 22 by solder 33. Since the solder 33 has excellent thermal conductivity, heat can be efficiently transferred from the wheel substrate 22 side to the base portion 30 side.

[0089] In addition, as the bonding material for the bonding connection portion 35, it is not limited to the solder 33, and a bonding material with excellent heat transfer properties can also be used.

[0090] In addition, the connection portion 35 can also be integrally formed with the reverse side 22b of the wheel substrate 22. Alternatively, the connection portion 35 can also be composed of a component different from the wheel substrate 22 and the base portion 30.

[0091] The connection portion 35 is interposed between the reverse side 22b of the wheel substrate 22 and the front side 30a of the base portion 30, thereby partially separating the reverse side 22b of the wheel substrate 22 from the front side 30a of the base portion 30. The wavelength conversion device 20 of the present embodiment forms a space S between the wheel substrate 22 and the base portion 30 by separating the reverse side 22b of the wheel substrate 22 from the front side 30a of the base portion 30. The space S is composed of a region where the connection portion 35 is not arranged.

[0092] In the present embodiment, a through hole 32 penetrating between the front side 30a and the reverse side 30b is provided in the base portion 30. The through hole 32 communicates the space S formed between the wheel substrate 22 and the base portion 30 with the outside. That is, in the present embodiment, the through hole 32 functions as an air inflow portion for allowing air to flow into the space S and an air outflow portion for allowing air to flow out of the space S.

[0093] As Figure 4B shown, the connection portion 35 includes a plurality of columnar bodies 36 and annular bodies 37, 38. The plurality of columnar bodies 36 include a plurality of first columnar bodies 36am and a plurality of second columnar bodies 36bm.

[0094] The plurality of first columnar bodies 36am are arranged at equal intervals in the circumferential direction of the central axis O. Each first columnar body 36am has a cylindrical shape. The connection portion 35 of the present embodiment includes a first columnar body group 36a composed of a plurality of first columnar bodies 36am. The first columnar body group 36a is arranged in the inner region R2 of the reverse side 22b of the wheel substrate 22.

[0095] The plurality of second columnar bodies 36bm are arranged at equal intervals in the circumferential direction of the central axis O with respect to the first columnar body group 36a and are arranged on the radially outer side. Each second columnar body 36bm has a cylindrical shape. The connection portion 35 of the present embodiment includes a second columnar body group 36b composed of a plurality of second columnar bodies 36bm. The second columnar body group 36b is arranged in the outer region R1 of the reverse side 22b of the wheel substrate 22.

[0096] The annular body 37 is formed in an annular shape with respect to the central axis O. The annular body 37 is disposed in the inner region R2 of the reverse side 22b of the wheel substrate 22. The annular body 37 is disposed radially inside the first columnar body group 36a. In the case of the present embodiment, the annular body 37 is disposed along the inner peripheral end of the reverse side 22b of the wheel substrate 22.

[0097] The annular body 38 is formed in an annular shape with respect to the central axis O. The annular body 38 is disposed radially outside the second columnar body group 36b. In the case of the present embodiment, the annular body 38 is disposed along the outer peripheral end of the reverse side 22b of the wheel substrate 22. In the present embodiment, a part of the annular body 38 is disposed overlapping the outer region R1 in the reverse side 22b of the wheel substrate 22. Further, the annular body 38 may be disposed outside the outer region R1.

[0098] As Figure 4B shown, the positions of the first columnar body 36am constituting the first columnar body group 36a and the second columnar body 36bm constituting the second columnar body group 36b in the radial direction are different from each other. That is, the first columnar body 36am and the second columnar body 36bm are disposed in a manner that they are not arranged linearly in the radial direction.

[0099] As Figure 2 shown, the wavelength conversion device 20 of the present embodiment causes the excitation light E from the first light source 40 to be incident on the upper surface 23a of the phosphor layer 23 that is rotated by the rotation driving unit 21, thereby emitting fluorescence Y. When the fluorescence Y is emitted, the phosphor layer 23 generates heat. The heat of the phosphor layer 23 is transferred to the wheel substrate 22.

[0100] The heat of the wheel substrate 22 is transferred from the reverse side 22b of the wheel substrate 22 to the base portion 30 via the connecting portion 35. The heat of the base portion 30 is released via the heat sink 31 provided on the reverse side 30b of the base portion 30.

[0101] Here, generally, the farther away from the heat source, the more difficult it is for heat to be transferred. Therefore, heat cannot be well transferred to the portion of the heat sink that is far from the heat source, and it is difficult for the entire heat sink to function effectively.

[0102] In the case of the present embodiment, since the phosphor layer 23 is provided on the radial outer side of the wheel substrate 22, the cooling performance of the heat sink 31 can be improved by transferring heat well to the radial inner side of the heat sink 31.

[0103] In the case of the present embodiment, the heat of the phosphor layer 23 is transferred to the radially inner side far from the phosphor layer 23 as the heat source through the wheel substrate 22. The heat transferred to the wheel substrate 22 is efficiently transferred to the inner side (center axis O side) of the base portion 30 via the connecting portion 35 in the inner region R2 on the radially inner side of the phosphor layer 23, that is, the first columnar body group 36a and the annular body 37. The heat transferred to the radially inner side (center axis O side) of the base portion 30 is efficiently transferred to the radially inner side (center axis O side) of the heat sink 31 provided on the reverse side 30b of the base portion 30.

[0104] Thus, in the wavelength conversion device 20 according to the present embodiment, the heat of the phosphor layer 23 can be transferred to the radially inner side of the heat sink 31 far from the phosphor layer 23 as the heat source.

[0105] In the wavelength conversion device 20 of the present embodiment, the heat of the wheel substrate 22 propagates to the base portion 30 through the space S formed between the wheel substrate 22 and the base portion 30. That is, the heat of the phosphor layer 23 can be transferred to the base portion 30 via the space S formed between the wheel substrate 22 and the base portion 30, and is transferred from the base portion 30 to the entire heat sink 31. The heat transferred to the base portion 30 is released via the heat sink 31.

[0106] However, due to the heat of the wheel substrate 22, the air in the space S between the wheel substrate 22 and the base portion 30 is heated. In the case of the present embodiment, the space S communicates with the outside through the through hole 32 formed in the base portion 30. Therefore, the air heated and thermally expanded in the space S is discharged to the outside via the through hole 32. Therefore, it is possible to suppress the occurrence of a malfunction such as deformation or detachment of the wheel substrate 22 and the base portion 30 due to the increase in the internal pressure of the space S caused by the thermally expanded air.

[0107] In addition, in the wavelength conversion device 20 of the present embodiment, the heat of the wheel substrate 22 is also efficiently transferred to the radially outer side of the base portion 30 via the connecting portion 35 provided in the outer region R1, that is, the second columnar body group 36b and the annular body 38. That is, in the case of the present embodiment, the heat of the wheel substrate 22 is efficiently transferred to the entire radial direction of the base portion 30. Therefore, heat can be efficiently transferred from the base portion 30 to the entire radial direction of the heat sink 31. Thus, by transferring the heat of the base portion 30 to the entire radial direction of the heat sink 31, heat can be efficiently dissipated from the entire heat sink 31.

[0108] In the case of the present embodiment, the plurality of heat sinks 31 rotate as the rotating body 29 rotates, thereby generating a wind from the radially inner side (center axis O side) of the base portion 30 toward the radially outer side. Therefore, cold air before heat absorption is supplied to the radially inner side (center axis O side) of the heat sink 31.

[0109] Therefore, in the wavelength conversion device 20 according to the present embodiment, by supplying cold air from the radially inner side (center axis O side) of the heat sink 31 that has received heat from the wheel substrate 22 toward the radially outer side, the entire heat sink 31 can be efficiently cooled. Therefore, the wavelength conversion device 20 of the present embodiment can improve the wavelength conversion efficiency of the phosphor layer 23 by efficiently cooling the phosphor layer 23, thereby generating bright fluorescence Y.

[0110] As described above, in the wavelength conversion device 20 according to the present embodiment, heat can be efficiently transferred to the radially inner side (center axis O side) of the heat sink 31 that is far from the phosphor layer 23 as a heat source. Moreover, by sending cold air from the radially inner side (center axis O side) of the heat sink 31, the cooling performance of the heat sink 31 can be improved. Therefore, the cooling performance of the heat sink 31 can be improved without increasing the size of the heat sink 31.

[0111] In addition, if the heat sink is enlarged, the weight of the heat sink unit increases. Therefore, as a rotation drive unit that rotates the heat sink unit, a large-sized motor device with a large driving force is required, resulting in a problem of increasing the size of the wavelength conversion device.

[0112] In contrast, in the wavelength conversion device 20 of the present embodiment, as described above, the enlargement of the heat sink 31 can be suppressed, so that the above problems can be suppressed. Thus, according to the present embodiment, a wavelength conversion device 20 can be provided that suppresses the enlargement of the device structure and improves the wavelength conversion efficiency of the phosphor layer 23 by efficiently cooling the phosphor layer 23, thereby generating bright fluorescence Y.

[0113] In addition, in the wavelength conversion device 20 of the present embodiment, the connecting portion 35 includes a plurality of columnar bodies 36.

[0114] According to this structure, a structure is formed in which the wheel substrate 22 and the base portion 30 are partially connected. Therefore, compared with the case where the connecting portion 35 is provided on the entire back surface 22b of the wheel substrate 22, an increase in the weight of the wavelength conversion device 20 can be suppressed. In addition, since the power burden on the rotation drive unit 21 can be reduced, a small-sized component can be used as the rotation drive unit 21.

[0115] In addition, in the wavelength conversion device 20 of the present embodiment, the connecting portion 35 includes a first columnar body group 36a composed of a plurality of first columnar bodies 36am arranged in the circumferential direction of the center axis O.

[0116] According to this structure, the wheel substrate 22 and the base portion 30 are partially connected in the circumferential direction of the central axis O. Thus, the rotating bodies of the wheel substrate 22 and the cooling fin unit 24 can rotate while maintaining balance with respect to the central axis O. Therefore, the power burden on the rotation driving unit 21 can be reduced. In addition, since heat can be propagated from the wheel substrate 22 toward the base portion 30 side in the circumferential direction of the central axis O, the annular phosphor layer 23 can be cooled uniformly. Therefore, the cooling efficiency of the phosphor layer 23 can be improved.

[0117] In addition, in the wavelength conversion device 20 of the present embodiment, the connecting portion 35 includes a second columnar body group 36b that is disposed radially outside the first columnar body group 36a and is composed of a plurality of second columnar bodies 36bm arranged in the circumferential direction of the central axis O.

[0118] According to this structure, by having the second columnar body group 36b radially outside the first columnar body group 36a, the heat conductivity from the wheel substrate 22 toward the base portion 30 side in the radial direction can be further improved. Therefore, the phosphor layer 23 can be cooled more efficiently.

[0119] In addition, in the wavelength conversion device 20 of the present embodiment, the first columnar body 36am constituting the first columnar body group 36a and the second columnar body 36bm constituting the second columnar body group 36b are different in position in the radial direction with respect to the central axis O.

[0120] According to this structure, compared with the case where the positions of the first columnar body 36am and the second columnar body 36bm are the same in the radial direction, the gap between the first columnar body 36am and the second columnar body 36bm can be sufficiently ensured. Thereby, heat can be uniformly transferred from the entire surface of the wheel substrate 22 toward the base portion 30 side, and therefore the cooling performance of the phosphor layer 23 can be further improved.

[0121] In addition, in the wavelength conversion device 20 of the present embodiment, the second columnar body group 36b is disposed in the outer region R1 corresponding to the phosphor layer 23.

[0122] According to this structure, the heat of the phosphor layer 23 can be transferred to the radially outer side of the heat sink 31 through the second columnar body group 36b. Therefore, by transferring heat from the wheel substrate 22 side to the entire radial direction of the heat sink 31, the cooling performance of the phosphor layer 23 can be further improved.

[0123] In addition, in the wavelength conversion device 20 of the present embodiment, the connecting portion 35 includes annular bodies 37 and 38 formed in a ring shape with respect to the central axis O.

[0124] According to this structure, the wheel substrate 22 and the base portion 30 are partially connected by the annular bodies 37 and 38. Therefore, compared with the case where the connecting portion 35 is provided on the entire back surface 22b of the wheel substrate 22, an increase in the weight of the wavelength conversion device 20 can be suppressed. In addition, since the power burden on the rotation drive unit 21 can be reduced, a small-sized component can be used as the rotation drive unit 21.

[0125] In addition, since the wheel substrate 22 and the base portion 30 are thermally connected in the entire circumferential direction, the annular phosphor layer 23 can be cooled uniformly. Therefore, the cooling efficiency of the phosphor layer 23 can be improved.

[0126] In addition, in the wavelength conversion device 20 of the present embodiment, the wheel substrate 22 and the connecting portion 35 are joined by solder.

[0127] According to this structure, heat can be efficiently transferred from the wheel substrate 22 side to the base portion 30 side via solder having excellent thermal conductivity. In addition, although the weight of the solder is large, in the present embodiment, by forming the connecting portion 35 into the above-described columnar body or annular body, the weight of the wavelength conversion device 20 can be suppressed.

[0128] The light source device 2 of the present embodiment includes a wavelength conversion device 20 and a first light source 40 that emits excitation light E toward the wavelength conversion device 20.

[0129] According to the light source device 2 of the present embodiment, since it has the wavelength conversion device 20 that suppresses the enlargement of the device structure and generates bright fluorescence Y, bright illumination light WL can be emitted in a small size.

[0130] The projector 1 of the present embodiment includes: a light source device 2; light modulation devices 4B, 4G, and 4R that modulate the light emitted from the light source device 2 according to an image signal; and a projection optical device 6 that projects the light modulated by the light modulation devices 4B, 4G, and 4R.

[0131] According to the projector 1 of the present embodiment, a small-sized projector with excellent display quality and high efficiency can be realized.

[0132] (Second Embodiment)

[0133] Hereinafter, a second embodiment of the present invention will be described.

[0134] The basic structure of the wavelength conversion device of the second embodiment is the same as that of the first embodiment, and the structures of the wheel substrate and the connecting portion are different from those of the first embodiment. Therefore, the same reference numerals are given to the basic structures common to the first embodiment, and their detailed descriptions are omitted.

[0135] Figure 6 is an exploded perspective view of the wavelength conversion device 120 of the second embodiment.Figure 7 It is a perspective view showing the function of the wavelength conversion device 120. In addition, Figure 7 For ease of observing the drawings, it is illustrated in a state where a part of the wheel substrate 22 is cut away.

[0136] As Figure 6 shown, the wavelength conversion device 120 of the present embodiment includes a rotation driving unit 21 and a rotating body 129. The rotating body 129 includes a wheel substrate 22, a phosphor layer 23, and a cooling fin unit 124.

[0137] The connecting portion 135 of the present embodiment includes a plurality of rod-shaped bodies 136 and an annular body 37. The plurality of rod-shaped bodies 136 radially extend from the inner region R2 toward the outer region R1. The plurality of rod-shaped bodies 136 are connected to the annular body 37 on the radially inner side. The height of the rod-shaped body 136 is equal to the height of the annular body 37.

[0138] As Figure 7 shown, the rod-shaped body 136 has a shape corresponding to the heat sink 31 formed on the reverse side 30b of the base portion 30. When the rod-shaped body 136 is viewed in the direction along the central axis O, it has the same outer shape as the heat sink 31. The rod-shaped body 136 is bent in an arcuate shape and formed in a spiral radial shape so as to extend in an inclined direction with respect to the outer edge normal of the base portion 30.

[0139] The rod-shaped bodies 136 are respectively arranged at positions corresponding to every other heat sink 31 in the circumferential direction. That is, the number of rod-shaped bodies 136 is half the number of heat sinks 31.

[0140] In the present embodiment, the connecting portion 135 has a structure in which only the radially inner sides of the rod-shaped bodies 136 are connected by the annular body 37.

[0141] On the outer peripheral surface 130 of the rotating body 129 of the present embodiment, a plurality of outer peripheral openings 130a, which are air outflow portions communicating with the space S1 formed between the wheel substrate 22 and the base portion 30, are formed. That is, the outer peripheral openings 130a are provided on the outer peripheral surface 130, which is the outer periphery of the space S1.

[0142] The space S1 formed between the wheel substrate 22 and the base portion 30 communicates with the outside through the outer peripheral openings 130a. In addition, in the present embodiment, a through hole 32 may be provided in the base portion 30, but since the space S1 communicates with the outside through the outer peripheral openings 130a, the through hole 32 may be omitted as needed (refer to Figure 3 ).

[0143] In the wavelength conversion device 120 of the present embodiment, on the inner circumferential side of the annular wheel substrate 22, a plurality of opening portions 121 serving as air inflow portions are formed along the circumferential direction. The plurality of opening portions 121 are formed in the inner region R2 that constitutes the space S1. Each opening portion 121 is arranged so as not to overlap with the connecting portion 135 in the axial direction along the central axis O. That is, the space S1 communicates with the outside through each opening portion 121.

[0144] According to the wavelength conversion device 120 of the present embodiment, the same effects as those of the above-described embodiment can be achieved. That is, in the present embodiment, the heat of the wheel substrate 22 is efficiently transferred to the radially inner side (central axis O side) of the base portion 30 through the connecting portion 135 formed by the rod-shaped body 136 in the inner region R2 located more radially inward than the phosphor layer 23. The heat transferred to the radially inner side (central axis O side) of the base portion 30 is efficiently transferred to the radially inner side (central axis O side) of the heat sink 31 provided on the reverse side 30b of the base portion 30.

[0145] In this way, according to the wavelength conversion device 120 of the present embodiment, heat can be efficiently transferred to the radially inner side (central axis O side) of the heat sink 31 that is far from the phosphor layer 23 serving as a heat source. Moreover, by sending cold air from the radially inner side (central axis O side) of the heat sink 31, the cooling performance of the heat sink 31 is improved, and thus the phosphor layer 23 can be efficiently cooled.

[0146] Further, in the wavelength conversion device 120 of the present embodiment, when the rotating body 129 rotates about the central axis O, air is sucked into the space S1 through the plurality of opening portions 121 formed in the wheel substrate 22. The air that has entered the space S1 travels along the rod-shaped body 136 toward the radially outer side and is discharged to the outside through the outer peripheral opening portion 130a formed on the outer peripheral surface 130 of the rotating body 129.

[0147] Here, when fluorescence Y is generated, the air in the space S1 between the wheel substrate 22 and the base portion 30 is heated by the heat of the wheel substrate 22. In the case of the present embodiment, the air that has been heated in the space S1 and thermally expanded is efficiently discharged to the outside together with the air that flows from the opening portion 121 toward the outer peripheral opening portion 130a. Thereby, it is possible to suppress the occurrence of a malfunction such as deformation or detachment of the wheel substrate 22 and the base portion 30 due to an increase in the internal pressure of the space S1 caused by the thermally expanded air.

[0148] In addition, the air that flows from the opening portion 121 toward the outer peripheral opening portion 130a is also used for cooling the base portion 30 and the wheel substrate 22. Therefore, according to the present embodiment, the cooling performance of the phosphor layer 23 can be further improved.

[0149] (Third Embodiment)

[0150] Hereinafter, a third embodiment of the present invention will be described.

[0151] The basic structure of the wavelength conversion device according to the third embodiment is the same as that of the first embodiment, and the difference from the first embodiment is the structure having a heat diffusion assisting member. Therefore, the same reference numerals are given to the basic structures common to the first embodiment, and their detailed descriptions are omitted.

[0152] Figure 8 FIG. 7 is an exploded perspective view of the wavelength conversion device 220 according to the third embodiment. Figure 9 FIG. 9 is a cross-sectional view showing the main part structure of the wavelength conversion device 220.

[0153] As shown in Figure 8 FIG. 14, the wavelength conversion device 220 according to the present embodiment includes a rotation driving unit 21 and a rotating body 229. The rotating body 229 includes a wheel substrate 22, a phosphor layer 23, a cooling fin unit 24, and a heat diffusion assisting member 70 interposed between the wheel substrate 22 and the base portion 30.

[0154] In the present embodiment, the heat diffusion assisting member 70 is located between the back surface 22b of the wheel substrate 22 and the connecting portion 35. The connecting portion 35 thermally connects the back surface 22b of the wheel substrate 22 and the front surface 30a of the base portion 30 via the heat diffusion assisting member 70.

[0155] The heat diffusion assisting member 70 is provided in a ring shape around the central axis O. The heat diffusion assisting member 70 is arranged radially between the annular bodies 37 and 38. The heat diffusion assisting member 70 is arranged so as to overlap with a plurality of columnar bodies 36.

[0156] That is, the heat diffusion assisting member 70 is arranged so as not to overlap with the annular bodies 37 and 38 in the axial direction. In the present embodiment, the wheel substrate 22 and the base portion 30 are joined via the annular bodies 37 and 38. In addition, in the case of the present embodiment, the height of the annular bodies 37 and 38 is set to the height obtained by adding the columnar bodies 36 and the heat diffusion assisting member 70 together.

[0157] Next, the structure of the heat diffusion assisting member 70 will be described.

[0158] As shown in Figure 9 FIG. 31, the heat diffusion assisting member 70 according to the present embodiment includes a heat-conductive housing 705 enclosing a working fluid, and the working fluid is changed between a liquid phase and a gas phase by an evaporation portion 700 and a condensation portion 701. In addition, the material for forming the housing 705 is a metal having heat conductivity such as copper.

[0159] The working fluid is enclosed in the housing 705 in a reduced pressure state. Therefore, the working fluid evaporates at a boiling point lower than that under atmospheric pressure in the space within the housing 705. In addition, water can be used as the working fluid.

[0160] The evaporation unit 700 evaporates the liquid working fluid and changes the liquid working fluid into a gaseous working fluid using heat transferred from the phosphor layer 23. The evaporation unit 700 includes a liquid retaining unit 703 for retaining the liquid working fluid and includes a region where the liquid retaining unit 703 is disposed.

[0161] The condensation unit 701 condenses the gas phase working fluid and changes the gas phase working fluid into the liquid phase working fluid. The condensation unit 701 is a portion including the radially inner region in the housing 705 .

[0162] The liquid retaining portion 703 is arranged at a position corresponding to the fluorescent layer 23. That is, the liquid retaining portion 703 is arranged to face the fluorescent layer 23 in the axial direction. The liquid retaining portion 703 has an annular outer shape when viewed from above in the axial direction.

[0163] The working fluid of the liquid phase is infiltrated and retained in the liquid holding portion 703. Therefore, the liquid holding portion 703 adopts a porous body with multiple holes, a fiber molded body, so that the working fluid of the liquid phase is infiltrated. As the forming material of the porous body, metals such as stainless steel, copper, glass, ceramics and other inorganic substances can be used. As the forming material of the fiber, metals such as stainless steel, copper, glass and other inorganic substances can be used. As the molded body, a molded body in which the fiber is compressed and molded to form a non-woven fabric, a molded body made of a mesh by weaving, etc. can be cited.

[0164] Furthermore, in the present embodiment, the positions of the evaporation portion 700 and the condensation portion 701 , except for the liquid retaining portion 703 , are changed according to the operating state of the heat diffusion auxiliary member 70 .

[0165] Based on such a structure, the heat H transferred to the heat diffusion auxiliary member 70 is transferred to the housing 705 via the wheel substrate 22. The evaporation unit 700 evaporates the liquid phase working fluid held in the liquid holding unit 703 using the heat H, and changes the liquid phase working fluid into a gas phase working fluid. At this time, the phosphor layer 23 is cooled by absorbing heat of vaporization of the liquid phase working fluid via the wheel substrate 22.

[0166] The working fluid that changes from the liquid phase to the gas phase retains the heat from the phosphor layer 23, and moves mainly as a flow T1 toward the central axis O side (radially inward) to reach the condensation portion 701. The condensation portion 701 condenses the working fluid in the gas phase, and changes the working fluid in the gas phase to the working fluid in the liquid phase. At this time, the working fluid in the gas phase dissipates heat and condenses. The heat released from the working fluid in the gas phase is released from the condensation portion 701 to the outside of the heat diffusion auxiliary component 70.

[0167] On the other hand, the working fluid that has changed from the gas phase to the liquid phase moves mainly as the flow T2 toward the evaporation portion 700 on the radially outer side.

[0168] In addition, the working medium flows T1 and T2 represent the main flow routes of the working fluid, and the flow of the working fluid is not limited thereto.

[0169] Here, in the case of the present embodiment, when the heat diffusion assisting member 70 operates, since the wheel substrate 22 rotates, a centrifugal force directed radially outward of the wheel substrate 22 is generated. As a result, the centrifugal force acts on the working fluid that changes from the gas phase to the liquid phase and promotes the movement radially outward. The liquid-phase working fluid that has moved to the evaporation section 700 is held by the liquid holding section 703.

[0170] Thus, the heat diffusion assisting member 70 of the present embodiment is a so-called vapor chamber, and by continuously and repeatedly causing evaporation and condensation of the working fluid, heat diffusion is achieved in the plane, thereby enabling cooling of the phosphor layer 23.

[0171] In the wavelength conversion device 220 of the present embodiment, the heat of the phosphor layer 23 is transferred to the heat diffusion assisting member 70 via the wheel substrate 22. The heat diffusion assisting member 70 diffuses the heat received from the wheel substrate 22 in the plane. Therefore, the connecting portion 35 formed by the first columnar body group 36a and the second columnar body group 36b can efficiently transfer the heat received from the heat diffusion assisting member 70 to the entire base portion 30. Therefore, by efficiently dissipating heat from the entire heat sink 31, the cooling efficiency of the phosphor layer 23 can be further improved, thereby generating bright fluorescence Y.

[0172] In addition, the technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

[0173] For example, in the above-described embodiment, the case where the connecting portions 35 and 135 are arranged in the outer region R1 and the inner region R2 on the back surface 22b of the wheel substrate 22 is cited as an example, but in the present invention, the connecting portion may be arranged only in the inner region R2.

[0174] (First Modification Example)

[0175] Hereinafter, the first modification example of the present invention will be described.

[0176] This modification example is a modification example related to the first embodiment. In the first embodiment, the case where the plurality of columnar bodies 36 constituting the connecting portion 35 are cylindrical shapes is cited as an example, but the shape of the columnar bodies is not limited thereto.

[0177] Figure 10 is a top view of the connecting portion of this modification example.

[0178] As Figure 10As shown, in this modification example, the plurality of columnar bodies 36 constituting the connecting portion 35 may also be, for example, a prismatic shape such as a quadrangular prism shape. In addition, the columnar body 36 is not limited to a quadrangular prism shape, and may be a triangular prism shape, a pentagonal prism shape, or a polygonal prism column with six or more sides. Alternatively, the columnar body 36 may also be an elliptical column shape.

[0179] (Second Modification Example)

[0180] Hereinafter, the second modification example of the present invention will be described.

[0181] This modification example is a modification example related to the third embodiment. In the third embodiment, an example of using a steam chamber as the heat diffusion assisting member is given, but the heat diffusion assisting member is not limited thereto.

[0182] Figure 11 is an exploded perspective view of the wavelength conversion device of this modification example.

[0183] The wavelength conversion device 220A of this modification example uses a heat diffusion assisting member 170 made of a graphite sheet as the rotating body 229A. The graphite sheet is, for example, a sheet formed by laminating two-dimensional crystallized carbon layers in a layered manner.

[0184] In addition, in the above embodiment, an example of applying a projector of one aspect of the present invention to a projector having three light modulation devices is shown, but it is not necessarily required to have a plurality of light modulation devices, and it may also have only one light modulation device.

[0185] Furthermore, the specific structures such as the number, arrangement, shape, and material of various structural elements constituting the projector are not limited to the above embodiment, and can be appropriately changed.

[0186] The wavelength conversion device according to an aspect of the present invention may also have the following structure.

[0187] A wavelength conversion device according to one aspect of the present invention includes: a rotation driving unit; a wheel substrate having thermal conductivity and rotating about a central axis by the rotation driving unit; a phosphor layer formed around the central axis on a first surface of the wheel substrate; and a cooling fin unit provided on a second surface of the wheel substrate opposite to the first surface. The cooling fin unit has a base portion joined to the wheel substrate and a plurality of heat dissipation fins provided on a side of the base portion opposite to the wheel substrate side. The second surface of the wheel substrate includes a first region corresponding to the phosphor layer and a second region closer to the central axis side than the first region. The second surface of the wheel substrate is separated from the surface of the base portion on the wheel substrate side, thereby forming a space between the wheel substrate and the base portion. A connecting portion for thermally connecting the second surface of the wheel substrate and the surface of the base portion on the wheel substrate side is disposed at least in the second region of the second surface.

[0188] In a wavelength conversion device according to one embodiment of the present invention, the following structure may also be adopted: heat of the phosphor layer is transmitted to the base portion through the space formed between the wheel substrate and the base portion.

[0189] In a wavelength conversion device according to one embodiment of the present invention, the following structure may also be adopted: the connecting portion includes a plurality of columnar bodies.

[0190] In a wavelength conversion device according to one embodiment of the present invention, the following structure may also be adopted: the connecting portion includes a first columnar body group composed of a plurality of first columnar bodies arranged in the circumferential direction around the central axis.

[0191] In a wavelength conversion device according to one embodiment of the present invention, the following structure may also be adopted: the connecting portion includes a second columnar body group, the second columnar body group is arranged on the radially outer side of the first columnar body group with respect to the central axis, and is composed of a plurality of second columnar bodies arranged in the circumferential direction around the central axis.

[0192] In a wavelength conversion device according to one embodiment of the present invention, the following structure may also be adopted: the first columnar bodies constituting the first columnar body group and the second columnar bodies constituting the second columnar body group have different positions in the radial direction of the central axis.

[0193] In a wavelength conversion device according to one embodiment of the present invention, the following structure may also be adopted: the second columnar body group is arranged in a first region corresponding to the phosphor layer in the second surface.

[0194] In a wavelength conversion device according to one embodiment of the present invention, the following structure may also be adopted: the connecting portion includes a plurality of rod-shaped bodies radially extending from the second region toward the first region.

[0195] In a wavelength conversion device according to one embodiment of the present invention, the following structure may also be adopted: the connecting portion includes an annular body formed in a ring shape around the central axis.

[0196] In a wavelength conversion device according to one embodiment of the present invention, the following structure may also be adopted: at least one of the wheel substrate and the base portion is joined to the connecting portion by solder.

[0197] In a wavelength conversion device according to one embodiment of the present invention, the following structure may also be adopted: it further includes: an air inflow portion that allows air to flow into the space; and an air outflow portion that allows air to flow out of the space.

[0198] In a wavelength conversion device according to one embodiment of the present invention, the following structure may also be adopted: the air inflow portion is provided in the second region constituting the space, and the air outflow portion is provided on the outer periphery of the space.

[0199] In the wavelength conversion device according to one embodiment of the present invention, the following structure may also be adopted: the heat sink unit further includes a heat diffusion assisting member, which is interposed between the wheel substrate and the base portion to diffuse heat in the plane, and the connecting portion receives heat from the heat diffusion assisting member.

[0200] In the wavelength conversion device according to one embodiment of the present invention, the following structure may also be adopted: the heat diffusion assisting member includes a heat-conductive housing enclosing a working fluid, and the working fluid is changed between the liquid phase and the gas phase by an evaporation portion and a condensation portion.

[0201] In the wavelength conversion device according to one embodiment of the present invention, the following structure may also be adopted: the heat diffusion assisting member is made of a graphite sheet.

[0202] The light source device according to an embodiment of the present invention may also have the following structure.

[0203] The light source device according to one embodiment of the present invention includes: the above-mentioned wavelength conversion device; and an excitation light source that emits excitation light toward the wavelength conversion device.

[0204] The projector according to an embodiment of the present invention may also have the following structure.

[0205] The projector according to one embodiment of the present invention includes: the above-mentioned light source device; a light modulation device that modulates the light from the light source device according to image information; and a projection optical device that projects the light modulated by the light modulation device.

Claims

1. A wavelength conversion device, characterized in that, The wavelength conversion device has: a rotation driving unit; a wheel substrate having thermal conductivity and rotated about a central axis by the rotation driving unit; a phosphor layer formed around the central axis on a first surface of the wheel substrate; and a cooling fin unit disposed on a second surface of the wheel substrate opposite to the first surface, wherein the cooling fin unit has a base portion joined to the wheel substrate and a plurality of heat dissipation fins provided on a side of the base portion opposite to the wheel substrate side, the second surface of the wheel substrate includes a first region corresponding to the phosphor layer and a second region closer to the central axis side than the first region, the second surface of the wheel substrate is separated from the wheel substrate side surface of the base portion, thereby forming a space between the wheel substrate and the base portion, a connecting portion for thermally connecting the second surface of the wheel substrate and the wheel substrate side surface of the base portion is disposed on the second surface, the connecting portion includes: a first columnar body group composed of a plurality of first columnar bodies arranged in the circumferential direction of the central axis; and a second columnar body group disposed radially outside the first columnar body group with respect to the central axis and composed of a plurality of second columnar bodies arranged in the circumferential direction of the central axis, the first columnar bodies constituting the first columnar body group and the second columnar bodies constituting the second columnar body group have different positions in the radial direction of the central axis, the first columnar body group is disposed in the second region, the second columnar body group is disposed in the first region.

2. The wavelength conversion device according to claim 1, wherein heat of the phosphor layer is transmitted to the base portion through the space formed between the wheel substrate and the base portion.

3. The wavelength conversion device according to claim 1 or 2, wherein the second columnar body group is disposed in the first region corresponding to the phosphor layer on the second surface.

4. The wavelength conversion device according to claim 1 or 2, wherein the connecting portion includes a first annular body formed in a ring shape around the central axis.

5. The wavelength conversion device according to claim 4, wherein the connecting portion includes a second annular body formed in a ring shape with respect to the central axis, the first annular body is disposed radially inside the central axis compared with the first columnar body group, the second annular body is disposed radially outside the central axis compared with the second columnar body group.

6. The wavelength conversion device according to claim 1 or 2, wherein at least one of the wheel substrate and the base portion is joined to the connecting portion by solder.

7. The wavelength conversion device according to claim 1 or 2, wherein the wavelength conversion device further has: an air inflow portion for allowing air to flow into the space; and an air outflow portion for allowing air to flow out of the space.

8. The wavelength conversion device according to claim 7, wherein the air inflow portion is disposed in the second region constituting the space, the air outflow portion is disposed on the outer periphery of the space.

9. The wavelength conversion device according to claim 1 or 2, wherein the cooling fin unit further has a heat diffusion assisting member that is interposed between the wheel substrate and the base portion to diffuse heat in the plane, and the connecting portion is heated by the heat diffusion assisting member.

10. The wavelength conversion device according to claim 5, wherein the cooling fin unit further has a heat diffusion assisting member that is interposed between the wheel substrate and the base portion to diffuse heat in the plane, the connecting portion is heated by the heat diffusion assisting member, and the heat diffusion assisting member is arranged so as not to overlap the first annular body and the second annular body in the direction along the central axis.

11. The wavelength conversion device according to claim 10, wherein the heat diffusion assisting member includes a heat-conductive housing enclosing a working fluid, and the working fluid is changed between a liquid phase and a gas phase by an evaporation portion and a condensation portion.

12. The wavelength conversion device according to claim 9, wherein the heat diffusion assisting member is made of a graphite sheet.

13. A light source device, characterized in that, The light source device includes: the wavelength conversion device according to any one of claims 1 to 12; and an excitation light source that emits excitation light toward the wavelength conversion device.

14. A projector, characterized in that, The projector includes: the light source device according to claim 13; a light modulation device that modulates light from the light source device according to image information; and a projection optical device that projects the light modulated by the light modulation device.

Images