Optical wheel, light conversion device, and projector

Abstract

The utility model provides an optical wheel, a light conversion device and a projector, which can realize light weight and miniaturization of the wheel. The optical wheel is provided with a rotatable wheel and a balancer that rotates together with the wheel and corrects the rotational balance of the wheel. The wheel is provided with: a disc-shaped substrate having a first surface and a second surface on the opposite side to the first surface; a color light changing body that is disposed on the first surface and that emits light having a peak wavelength different from the peak wavelength of the incident light; and a plurality of fins disposed on the second surface and extending from a portion on the center side of the substrate toward the outer peripheral edge of the substrate. The balancer is disposed between two of the plurality of fins that face each other.

Description

Technical Field

[0001] The utility model relates to an optical wheel, a light conversion device and a projector. Background Art

[0002] Conventionally, there is known a phosphor wheel device used in a projector that emits fluorescent light obtained by converting the wavelength of incident blue light (see, for example, Patent Document 1).

[0003] The fluorescent wheel device described in Patent Document 1 includes a motor, a fluorescent wheel substrate, a first balancer, and a second balancer. The motor has a rotor, and the fluorescent wheel substrate is attached to one end of the motor's rotating shaft. The first balancer is fixed to the fluorescent wheel substrate at one end of the motor, and the second balancer is integrally attached to the rotor at the other end of the motor's rotating shaft. Furthermore, a fluorescent layer is provided on the surface of the fluorescent wheel substrate on one end of the rotating shaft, concentric with the rotating shaft.

[0004] The first balancer and the second balancer are formed in a flat hollow cylindrical shape.

[0005] Here, if the center of gravity of the phosphor wheel substrate does not coincide with the rotation axis, not only reliability cannot be ensured, but also noise increases.

[0006] In contrast, in the fluorescent substance wheel device described in Patent Document 1, the center of gravity position of the fluorescent substance wheel substrate is adjusted by cutting at least one of the first balancer and the second balancer using a cutting machine.

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2021-85953. Utility Model Content

[0008] However, near the rotating shaft, the fluctuation in balance caused by the balancer's cutting is small. Therefore, the fluorescent wheel device described in Patent Document 1 requires a larger balancer, which tends to increase the weight of each balancer. As each balancer becomes larger, the size of the fluorescent wheel device on the rotating shaft increases. Furthermore, as the weight of each balancer increases, the inertial load increases, requiring a motor that generates high torque.

[0009] Therefore, a lightweight and compact wheel structure is desired.

[0010] The optical wheel disclosed herein comprises: a rotatable wheel; and a balancer that rotates together with the wheel to correct the rotational balance of the wheel, the wheel comprising: a disc-shaped substrate having a first surface and a second surface on the side opposite to the first surface; a color changer that is arranged on the first surface and emits light having a peak wavelength different from the peak wavelength of the incident light; and a plurality of fins that are arranged on the second surface and extend from a portion on the center side of the substrate toward the outer periphery of the substrate, the balancer being arranged between two opposing fins among the plurality of fins.

[0011] The light conversion device disclosed in the present disclosure includes the optical wheel and a motor for rotating the optical wheel.

[0012] The projector disclosed herein includes: the light conversion device; a light source that emits light incident on the light conversion device; an image generating device that generates image light based on the light emitted from the light conversion device; and a projection optical device that projects the generated image light. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram showing the structure of the projector according to the first embodiment.

[0014] Figure 2 This is a schematic diagram showing the structure of the light source device according to the first embodiment.

[0015] Figure 3 This is a perspective view showing the wavelength conversion device according to the first embodiment.

[0016] Figure 4 This is a perspective view showing the wavelength conversion device according to the first embodiment.

[0017] Figure 5 This is an exploded perspective view showing the wavelength conversion device according to the first embodiment.

[0018] Figure 6 This is an exploded perspective view showing the wavelength conversion device according to the first embodiment.

[0019] Figure 7 This is a diagram showing the wavelength conversion device according to the first embodiment as viewed from the side opposite to the incident side of the excitation light.

[0020] Figure 8 This is a diagram showing the wavelength conversion device according to the second embodiment as viewed from the side opposite to the incident side of the excitation light.

[0021] Figure 9 This is a diagram illustrating the direction of the shear force acting on the sample fixed to the substrate of the second embodiment.

[0022] Figure 10The figure shows the intersection angle α between the extension direction of the upstream fin toward the outer peripheral edge and the tangent line to the substrate at the intersection position of the extension direction of the upstream fin and the outer peripheral edge of the substrate in the second embodiment.

[0023] Figure 11 The diagram shows an intersection angle β between the extension direction of the downstream fin toward the outer peripheral edge and the tangent line to the substrate at the intersection of the extension direction of the downstream fin and the outer peripheral edge of the substrate in the second embodiment.

[0024] Figure 12 This is a diagram showing a wavelength conversion device according to a first modified example of the wavelength conversion device according to the second embodiment.

[0025] Figure 13 This is a diagram showing a wavelength conversion device according to a second modified example of the wavelength conversion device according to the second embodiment.

[0026] Figure 14 This is a perspective view showing a wavelength conversion device according to a third embodiment.

[0027] Figure 15 It is a perspective view showing a deformation of the enlarged portion of the wavelength conversion device according to the third embodiment.

[0028] Figure 16 It is a perspective view showing a wavelength conversion device according to a fourth embodiment.

[0029] Figure 17 It is a schematic diagram showing the structure of an image projection device included in a projector according to a fifth embodiment.

[0030] Figure 18 This is a plan view of the light conversion device according to the fifth embodiment as viewed from the light incident side.

[0031] Description of labels

[0032] 1, 1G: Projector; 2: Image projection device; 24: Image generation device; 26: Projection optical device; 3: Light source device; 32: Light source; 5A, 5B, 5C, 5D, 5E: Wavelength conversion device (light conversion device); 51A, 51B, 51E, 51F: Phosphor wheel (optical wheel); 52A, 52E, 52F: Wheel; 53, 53F: Substrate; 531: First surface; 532: Second surface; 533: Opening; 534: Protrusion; 535: Step; 54: Wavelength converter (color changer); 55: Reflecting portion; 56: Fin; 56A: Fin (upstream fin); 56B: Fin (downstream fin); 561: First end portion; 562: Second end portion; 563: Connecting portion; 57A, 57B, 57C, 57D: Balancer; 58: Motor; 581: Motor body; 582: Support substrate; 5821: Control circuit; 583: Rotating body; 5831: Columnar portion; 5832: Flange portion; 5833: Through hole; 59: Fin; 59A: Fin (Fin on the upstream side); 59B: Fin (Fin on the downstream side); 591, 592: Enlarging portion; 7: Image projection device; 71: Light source; 74: Image generating device; 8: Light conversion device; 81: Color wheel (optical wheel); 82: Wheel; 84: Wavelength changer (color light changer). DETAILED DESCRIPTION

[0033] First embodiment

[0034] Hereinafter, a first embodiment of the present disclosure will be described with reference to the drawings.

[0035] Schematic structure of a projector

[0036] Figure 1 Schematic diagram showing the configuration of the projector 1 according to this embodiment.

[0037] The projector 1 of this embodiment projects image light corresponding to image information. Figure 1 As shown, the projector 1 includes an outer casing 11 and an image projection device 2 housed in the outer casing 11. Although not shown in the figure, the projector 1 also includes a control device for controlling the operation of the projector 1, a power supply device for supplying power to electronic components of the projector 1, and a cooling device for cooling an object to be cooled by the projector 1.

[0038] Structure of image projection device

[0039] The image projection device 2 forms image light corresponding to input image information and projects the formed image light. The image projection device 2 includes a light source device 3, a uniformizing optical system 21, a color separation optical system 22, a relay optical system 23, an image generating device 24, an optical component housing 25, and a projection optical device 26.

[0040] The light source device 3 emits illumination light toward the uniformizing optical system 21. The structure of the light source device 3 will be described in detail later.

[0041] The homogenizing optical system 21 homogenizes the illumination light emitted from the light source device 3. The homogenized illumination light illuminates the modulation area of ​​the light modulator 243, described later, via the color separation optical system 22 and the relay optical system 23. The homogenizing optical system 21 includes two lens arrays 211 and 212, a polarization conversion element 213, and a superimposing lens 214.

[0042] The color separation optical system 22 separates the illumination light input from the uniformization optical system 21 into red, green, and blue light. The color separation optical system 22 includes two dichroic mirrors 221 and 222 and a reflection mirror 223 that reflects the blue light separated by the dichroic mirror 221 .

[0043] The relay optical system 23 is located in the optical path of red light, which has a longer optical path than the other colored light, to minimize red light loss. The relay optical system 23 includes an incident-side lens 231, a relay lens 233, and reflectors 232 and 234. In this embodiment, red light is directed to the relay optical system 23. However, this is not limiting. For example, a configuration may be employed in which the colored light having a longer optical path than the other colored light is blue light and directed to the relay optical system 23.

[0044] The image generating device 24 generates image light based on the light emitted from the light source device 3. Specifically, the image generating device 24 generates image light based on the light emitted from the wavelength conversion device 5A (described later) of the light source device 3. Specifically, the image generating device 24 modulates the incident red, green, and blue light, synthesizes the modulated light, and generates image light.

[0045] The image generating device 24 includes three field lenses 241 , three incident-side polarizing plates 242 , three light modulating elements 243 , three outgoing-side polarizing plates 244 , and a color synthesis optical system 245 , which are arranged according to the incident color light.

[0046] The light modulator 243 modulates the light from the light source device 3 to form image light. Specifically, the light modulator 243 modulates the color light incident from the incident-side polarizer 242 according to the image signal and emits the modulated color light. The three light modulators 243 include a light modulator 243R that modulates red light, a light modulator 243G that modulates green light, and a light modulator 243B that modulates blue light. A transmissive liquid crystal panel can be used as an example of the light modulator 243.

[0047] The color synthesis optical system 245 synthesizes the three colored lights modulated by the light modulators 243R, 243G, and 243B. The image light synthesized by the color synthesis optical system 245 is incident on the projection optical device 26. In this embodiment, the color synthesis optical system 245 is composed of a substantially rectangular cross dichroic prism, but it can also be composed of multiple dichroic mirrors.

[0048] The optical component housing 25 houses the uniformizing optical system 21, color separation optical system 22, relay optical system 23, and image generation device 24. Furthermore, a design optical axis Ax1 is set in the image projection device 2, and the optical component housing 25 holds the uniformizing optical system 21, color separation optical system 22, relay optical system 23, and image generation device 24 at predetermined positions along the optical axis Ax1. The light source device 3 and the projection optical system 26 are arranged at predetermined positions along the optical axis Ax1.

[0049] The projection optical device 26 projects the image light incident from the image generating device 24 onto a projection surface such as a screen. In other words, the projection optical device 26 projects the image light formed by the image generating device 24. The projection optical device 26 may be, for example, a lens assembly having a plurality of lenses (not shown) and a lens barrel 261 housing the plurality of lenses.

[0050] Structure of light source device

[0051] Figure 2 It is a schematic diagram showing the structure of the light source device 3.

[0052] The light source device 3 emits illumination light for illuminating the image generating device 24 toward the uniformizing optical system 21. Figure 2 As shown, the light source device 3 has a light source shell 31, a light source 32, an afocal optical element 33, a first phase difference element 34, a diffuse transmission element 35, a light separation and synthesis element 36, a first focusing element 37, a second phase difference element 38, a second focusing element 39, a diffuse optical element 40, a third phase difference element 41 and a wavelength conversion device 5A.

[0053] An optical axis Ax2 extending linearly and an optical axis Ax3 extending linearly and perpendicular to the optical axis Ax2 are set in the light source device 3. The optical axis Ax3 overlaps with the optical axis Ax1 in the uniformizing optical system 21.

[0054] The light source 32 , the afocal optical element 33 , the first phase difference element 34 , the diffuser and transmissive element 35 , the light separation and combination element 36 , the second phase difference element 38 , the second light converging element 39 , and the diffuser optical element 40 are arranged on the optical axis Ax2 .

[0055] The wavelength converter 5A, the first light converging element 37 , the light separating and combining element 36 , and the third phase difference element 41 are arranged on the optical axis Ax3 .

[0056] In the following description, three mutually orthogonal directions are referred to as the +X direction, the +Y direction, and the +Z direction. In this embodiment, the +X direction is the direction in which light source 32 emits light along optical axis Ax2, and the +Z direction is the direction in which light source device 3 emits illumination light along optical axis Ax3. Although not shown in the figure, the direction opposite to the +X direction is referred to as the -X direction, the direction opposite to the +Y direction is referred to as the -Y direction, and the direction opposite to the +Z direction is referred to as the -Z direction.

[0057] Structure of light source housing

[0058] The light source housing 31 houses a light source 32, an afocal optical element 33, a first phase difference element 34, a diffuser and transmissive element 35, a light separation and combination element 36, a first light converging element 37, a second phase difference element 38, a second light converging element 39, a diffuser optical element 40, a third phase difference element 41, and a wavelength converter 5A. The light source housing 31 is a sealed housing that is difficult for dust and the like to infiltrate.

[0059] Light source structure

[0060] The light source 32 includes at least one solid-state light-emitting element 321. This element 321 emits light toward the optical diffuser 40 and wavelength converter 5A in the +X direction. The solid-state light-emitting element 321 emits blue light as excitation light. For example, the solid-state light-emitting element 321 is a laser diode (LD) that emits laser light with a peak wavelength of 440 nm.

[0061] The light emitted by the light source 32 is s-polarized blue light BLs relative to the light separation and combination element 36. However, the light emitted by the light source 32 is not limited to this. The light emitted by the light source 32 may be p-polarized blue light BLp relative to the light separation and combination element 36, or may be a mixture of s-polarized and p-polarized blue light. In the latter case, the first phase difference element 34 can be omitted.

[0062] Structure of afocal optical elements

[0063] The afocal optical element 33 adjusts the beam diameter of the blue light BLs incident in the +X direction from the light source 32. The afocal optical element 33 is composed of a lens 331 that converges the incident light and a lens 332 that collimates the beam converged by the lens 331. Alternatively, the afocal optical element 33 may be omitted.

[0064] Structure of the first phase difference element

[0065] The first phase difference element 34 is disposed between lens 331 and lens 332. The first phase difference element 34 converts a portion of the incident blue light BLs into blue light BLp, emitting light containing s-polarized blue light BLs and p-polarized blue light BLp. The first phase difference element 34 can also be rotated about a rotation axis along the optical axis Ax2 by a rotating device. In this case, the ratio of the s-polarized component to the p-polarized component in the blue light emitted from the first phase difference element 34 can be adjusted according to the rotation angle of the first phase difference element 34.

[0066] Structure of the diffuse transmission element

[0067] The diffuser transmissive element 35 uniformizes the illuminance distribution of the blue light beams BLp and BLs incident in the +X direction from the lens 332. The blue light beams BLs and BLp that have passed through the diffuser transmissive element 35 are incident on the light separation and combination element 36. Examples of the diffuser transmissive element 35 include a holographic structure, a structure in which a plurality of small lenses are arranged on a surface perpendicular to the optical axis, and a structure in which the surface through which light passes is roughened.

[0068] In addition, a beam homogenizing optical element having a pair of multiple lenses may be used instead of the diffusion transmission element 35 .

[0069] Structure of the light separation and combination element

[0070] The light separating and combining element 36 has a function as a light separating element for separating incident light and a function as a light combining element for combining light incident from two directions.

[0071] The light separation and synthesis element 36 is a polarization beam splitter that separates the s-polarization component and the p-polarization component contained in the incident light. Specifically, the light separation and synthesis element 36 reflects the s-polarization component and transmits the p-polarization component. In addition, the light separation and synthesis element 36 has a color separation characteristic that transmits light with a wavelength above a specified wavelength, regardless of whether the s-polarization component or the p-polarization component is incident on the light separation and synthesis element 36. Therefore, of the blue light BLp and BLs incident on the light separation and synthesis element 36 from the diffuse transmission element 35, the p-polarized blue light BLp passes through the light separation and synthesis element 36 in the +X direction and enters the second phase difference element 38. On the other hand, the s-polarized blue light BLs is reflected by the light separation and synthesis element 36 in the -Z direction and enters the first focusing element 37.

[0072] Alternatively, the light separation and combination element 36 may have the following functions: a half mirror function, allowing a portion of the light incident from the light source 32 via the diffuser and transmissive element 35 to pass through and reflecting the remaining light; and a dichroic mirror function, reflecting the blue light incident from the diffuser optical element 40 and transmitting fluorescence incident from the wavelength converter 5A and having a wavelength longer than that of the blue light. In this case, the first phase difference element 34 can be omitted.

[0073] Structure of the first light concentrating element

[0074] The first light concentrating element 37 constitutes the pickup optical system. The first light concentrating element 37 converges the blue light BLs reflected in the -Z direction by the light separation and combination element 36 onto the wavelength converter 54 (described later) of the phosphor wheel 51A included in the wavelength converter 5A. Furthermore, the first light concentrating element 37 collimates the fluorescence YL incident in the +Z direction from the wavelength converter 54 and emits the collimated fluorescence YL toward the light separation and combination element 36. In this embodiment, the first light concentrating element 37 is composed of three lenses 371, 372, and 373, but the number of lenses comprising the first light concentrating element 37 is not limited.

[0075] Schematic structure of wavelength conversion device

[0076] The wavelength converter 5A includes a phosphor wheel 51A that converts the wavelength of blue light BLs incident from the first light converging element 37 and emits fluorescent light YL. The phosphor wheel 51A is a so-called reflective wavelength converter and emits fluorescent light YL in a direction opposite to the incident direction of the blue light BLs, which serves as excitation light. The structure of the wavelength converter 5A will be described in detail later.

[0077] The fluorescence YL emitted from the wavelength converter 5A in the +Z direction is collimated by the first light converging element 37 and then enters the light separating and combining element 36. As described above, the light separating and combining element 36 has the property of transmitting the fluorescence YL. Therefore, the fluorescence YL entering the light separating and combining element 36 in the +Z direction passes through the light separating and combining element 36 and enters the third phase difference element 41.

[0078] Structure of the second phase difference element

[0079] The second phase difference element 38 is positioned in the +X direction relative to the light separation and combination element 36. Specifically, the second phase difference element 38 is positioned between the light separation and combination element 36 and the second light converging element 39. The second phase difference element 38 converts the blue light BLp that passes through the light separation and combination element 36 in the +X direction into circularly polarized blue light BLc. The blue light BLc that passes through the second phase difference element 38 in the +X direction enters the second light converging element 39.

[0080] Structure of the second light-concentrating element

[0081] The second light concentrating element 39 converges the blue light BLc, which has passed through the light separating and combining element 36 in the +X direction and entered from the second phase difference element 38, toward the optical diffuser 40. Furthermore, the second light concentrating element 39 collimates the light entering from the optical diffuser 40 in the -X direction and emits the collimated light toward the second phase difference element 38. In this embodiment, the second light concentrating element 39 is composed of three lenses 391, 392, and 393, but the number of lenses that constitute the second light concentrating element 39 is not limited.

[0082] Structure of diffusion optical elements

[0083] The optical diffuser 40 diffuses the incident blue light BLc at the same diffusion angle as the fluorescence YL emitted from the wavelength converter 5A. Specifically, the optical diffuser 40 reflects and diffuses the blue light BLc incident from the second light converging element 39 in the +X direction in the -X direction. The optical diffuser 40 is a reflective element that causes the incident blue light BLc to undergo Lambertian reflection. Furthermore, the optical diffuser 40 can be rotated by a rotating device about an axis parallel to the optical axis Ax2.

[0084] The blue light BLc diffused by the optical diffuser 40 passes through the second light-concentrating element 39 and then enters the second phase difference element 38. The blue light BLc entering the optical diffuser 40 is converted into circularly polarized light with an opposite rotation direction when reflected by the optical diffuser 40. Therefore, the blue light BLc entering the second phase difference element 38 via the second light-concentrating element 39 is converted by the second phase difference element 38 into s-polarized blue light BLs. Furthermore, the blue light BLs is reflected in the +Z direction by the light separation and combination element 36 and enters the third phase difference element 41. In other words, the light entering the third phase difference element 41 from the light separation and combination element 36 is white light containing a mixture of blue light BLs and fluorescent light YL.

[0085] Structure of the third phase difference element

[0086] The third phase difference element 41 converts the white light containing the blue light BLs and the fluorescence YL incident from the light separation and combination element 36 into white light containing a mixture of s-polarized light and p-polarized light. The converted white light is emitted in the +Z direction as illumination light LT and enters the uniformization optical system 21.

[0087] Structure of wavelength conversion device

[0088] Figure 3 and Figure 4 : is a perspective view showing the wavelength conversion device 5A. Figure 3 1 is a perspective view showing the wavelength conversion device 5A viewed from the incident side of the blue light BLs. Figure 41 is a perspective view showing the wavelength conversion device 5A viewed from the side opposite to the incident side of the blue light BLs.

[0089] Figure 5 and Figure 6 : is an exploded perspective view showing the wavelength conversion device 5A. Figure 5 1 is an exploded perspective view showing the wavelength conversion device 5A viewed from the incident side of the blue light BLs. Figure 4 1 is an exploded perspective view showing the wavelength conversion device 5A viewed from the side opposite to the incident side of the blue light BLs.

[0090] The wavelength converter 5A is a light converter that emits colored light having a peak wavelength different from the peak wavelength of the incident light. In other words, the wavelength converter 5A emits converted light by converting the wavelength of the incident excitation light. Specifically, the wavelength converter 5A emits fluorescent light YL, which has a wavelength band longer than that of the incident excitation light, i.e., blue light BLs.

[0091] like Figures 3 to 6 As shown, the wavelength conversion device 5A includes a fluorescent wheel 51A and a motor 58. The fluorescent wheel 51A and the motor 58 are combined to form a suction unit for sucking cooling gas into the wavelength conversion device 5A.

[0092] Motor structure

[0093] First, the motor 58 will be described.

[0094] The motor 58 rotates the fluorescent wheel 51A around the rotation axis Rx. The motor 58 includes a motor body 581 , a support substrate 582 , and a rotating body 583 .

[0095] Although detailed illustration is omitted, the motor body 581 includes a rotor and a stator that rotates the rotor.

[0096] The support substrate 582 supports the motor body 581. Figure 4 and Figure 6 As shown, the support substrate 582 includes a control circuit 5821, which is connected to the aforementioned control device via the flexible printed circuit board FP. The control circuit 5821 drives the motor body 581 based on an electrical signal input via the flexible printed circuit board FP.

[0097] Rotating body 583 is fixed to the rotor of motor body 581 and rotates integrally with the rotor. Rotating body 583 is connected to fluorescent body wheel 51A and rotates together with fluorescent body wheel 51A through motor body 581. Rotating body 583 is arranged on the fluorescent body wheel 51A side relative to motor body 581.

[0098] like Figure 5As shown, the rotating body 583 has a columnar portion 5831 and a flange portion 5832 .

[0099] The columnar portion 5831 is a portion that projects in the +Z direction in a cylindrical shape with the rotation axis Rx as the center.

[0100] The flange portion 5832 is located outside the columnar portion 5831 and is formed into a disk shape centered on the rotation axis Rx. The flange portion 5832 engages with the protrusion 534 of the wheel 52A of the fluorescent wheel 51A. Specifically, the flange portion 5832 contacts the end of the protrusion 534 in the -Z direction.

[0101] When viewed from the +Z direction, the outer diameter of the flange portion 5832 is larger than the outer diameter of the motor body 581. A plurality of through holes 5833 are provided on the periphery of the flange portion 5832 so as to penetrate the flange portion 5832 along the rotation axis Rx.

[0102] The plurality of through-holes 5833 are arranged at equal intervals in the circumferential direction centered on the rotation axis Rx. Specifically, the plurality of through-holes 5833 are provided in the flange portion 5832 at positions corresponding to the protrusions 534. The screws SC connecting the rotating body 583 to the fluorescent body wheel 51A pass through each through-hole 5833 in the +Z direction. The screws SC passing through the through-holes 5833 are then fixed to the protrusions 534, thereby connecting the rotating body 583 to the fluorescent body wheel 51A.

[0103] Structure of phosphor wheel

[0104] The fluorescent substance wheel 51A corresponds to an optical wheel, and is rotated by a motor 58. The fluorescent substance wheel 51A includes a wheel 52A and a balancer 57A.

[0105] The wheel 52A is rotatable by a motor 58. The wheel 52A includes a substrate 53, a wavelength converter 54, a reflecting portion 55, and a plurality of fins 56.

[0106] Substrate structure

[0107] The substrate 53 is disk-shaped and supports the wavelength converter 54, the reflector 55, and the plurality of fins 56. The substrate 53 is rotated about a rotation axis Rx by a motor 58 having a rotating body 583 connected to the substrate 53. The substrate 53 is annular centered about the rotation axis Rx and is formed, for example, of metal. The substrate 53 has a first surface 531, a second surface 532, and an opening 533.

[0108] The first surface 531 is a surface facing the +Z direction. The wavelength converter 54 and the reflector 55 are arranged on the first surface 531 .

[0109] The second surface 532 is a surface on the opposite side to the first surface 531 and faces the −Z direction. A plurality of fins 56 are arranged on the second surface 532 .

[0110] The opening 533 extends through the substrate 53 along the rotation axis Rx, from the first surface 531 to the second surface 532. The opening 533 is formed into a circular shape when viewed from the incident side of the excitation light, i.e., the +Z direction. When the substrate 53 rotates, air flows from the space in the +Z direction relative to the substrate 53 into the opening 533, as described in detail later.

[0111] Structure with multiple protrusions

[0112] like Figure 4 and Figure 6 As shown, the base plate 53 further has a plurality of protrusions 534 .

[0113] Multiple protrusions 534 are provided at equal intervals in the circumferential direction centered on the rotation axis Rx, outside the opening 533 in the second surface 532 and near the inner periphery of the opening 533. Specifically, the multiple protrusions 534 protrude from the second surface 532 in the -Z direction toward the rotating body 583. Each of the multiple protrusions 534 has a threaded hole for inserting a screw SC along the +Z direction. By fastening a screw SC, which is inserted through a through hole 5833 in the rotating body 583 along the +Z direction, to the threaded hole of each protrusion 534, the substrate 53 of the fluorescent wheel 51A is connected to the rotating body 583.

[0114] Structure of wavelength converter and reflector

[0115] The wavelength converter 54 is a color-changing element disposed on the first surface 531 of the substrate 53. The wavelength converter 54 emits light having a peak wavelength different from the peak wavelength of the incident light. Specifically, the wavelength converter 54 emits fluorescent light YL having a peak wavelength longer than the peak wavelength of the incident blue light BLs. In other words, the wavelength converter 54 emits fluorescent light YL, which has a wavelength band different from that of the incident excitation light, or blue light BLs.

[0116] The wavelength converter 54 includes a fluorescent material that is excited by incident excitation light and emits fluorescent light YL, which is converted light having a wavelength longer than that of the excitation light.

[0117] like Figure 3 and Figure 5 As shown, the wavelength converter 54 is formed in an annular shape with the rotation axis Rx as the center when viewed from the +Z direction, and is fixed to the outside of the opening 533 on the first surface 531 of the substrate 53 .

[0118] The reflecting portion 55 is disposed between the first surface 531 of the substrate 53 and the wavelength converter 54. The reflecting portion 55 reflects light incident from the wavelength converter 54 toward the wavelength converter 54 side.

[0119] The reflective portion 55 can be configured as a reflective layer provided on the first surface 531 or the wavelength converter 54. In this case, the reflective portion 55 may be a reflective layer provided on substantially the entire surface of the first surface 531. Furthermore, if the first surface 531 has sufficiently high light reflectivity, the first surface 531 can be used as the reflective portion 55.

[0120] Multiple fin structure

[0121] The plurality of fins 56 rotates together with the substrate 53, generating airflow to dissipate heat transferred from the wavelength converter 54. The plurality of fins 56 are provided on the second surface 532 of the substrate 53 facing the motor 58. Specifically, the plurality of fins 56 are provided integrally on the second surface 532. Figure 5 As shown, the plurality of fins 56 extend from a portion of the base plate 53 on the rotation axis Rx side toward the outer periphery of the base plate 53. That is, the plurality of fins 56 extend from a portion on the center side of the base plate 53 toward the outer periphery of the base plate 53.

[0122] The plurality of fins 56 are arranged around the opening 533. Specifically, the plurality of fins 56 are arranged at equal intervals in the circumferential direction around the rotation axis Rx around the opening 533. When the fluorescent wheel 51A is rotated by the motor 58, the plurality of fins 56 rotate integrally with the substrate 53.

[0123] Each of the plurality of fins 56 has a first end portion 561 , a second end portion 562 , and a connecting portion 563 .

[0124] The first end portion 561 is an end portion on the rotation axis Rx side of the fin 56. The first end portion 561 is arranged outside the opening 533 and in the vicinity of the inner peripheral edge of the opening 533.

[0125] The second end portion 562 is an end portion of the fin 56 on the outer peripheral edge side of the substrate 53 and is disposed on the outer peripheral edge of the second surface 532 of the substrate 53. Alternatively, the second end portion 562 may be located slightly closer to the rotation axis Rx than the outer peripheral edge of the substrate 53.

[0126] Figure 7 This is a diagram showing the wavelength conversion device 5A viewed from the side opposite to the incident side of the excitation light. Figure 7 1 is a plan view showing the wavelength conversion device 5A viewed from the -Z direction.

[0127] like Figure 7As shown, each fin 56 extends in a curved shape as viewed from the -Z direction, moving from the first end 561 toward the outer peripheral edge of the substrate 53, thereby becoming located in a direction opposite to the rotational direction RD of the substrate 53. In other words, each fin 56 is formed in an arc shape as viewed from the -Z direction. However, the present invention is not limited to this, and each fin 56 may also extend in a curved shape as viewed from the first end 561 toward the outer peripheral edge of the substrate 53, thereby becoming located in the rotational direction RD.

[0128] Alternatively, each fin 56 may extend linearly when viewed from the -Z direction. In this case, each fin 56 may extend radially with the rotation axis Rx as the center, or may extend linearly in the direction of rotation RD or in the direction opposite to the rotation direction RD as it moves from the first end 561 toward the outer peripheral edge of the substrate 53.

[0129] Furthermore, each fin 56 may be arranged at a position where an extension line of the fin 56 extending toward the rotation axis Rx does not intersect the rotation axis Rx. In other words, the extension line of each fin 56 extending toward the rotation axis Rx does not intersect the rotation axis Rx. Furthermore, the number of fins 56 may be varied as appropriate, as long as there are two or more.

[0130] The connecting portion 563 is a stepped portion provided on the portion of the fin 56 on the rotation axis Rx side including the first end portion 561. The connecting portion 563 is a portion of the fin 56 that protrudes less from the second surface 532 in the -Z direction than other portions. When the fluorescent wheel 51A is coupled to the motor 58, the connecting portion 563 can contact the +Z direction surface of the flange portion 5832 of the rotating body 583.

[0131] In addition, the connection portion 563 does not necessarily need to be a step portion. That is, the surface of each fin 56 facing the rotating body 583 can function as the connection portion 563 and contact the flange portion 5832 of the rotating body 583. On the other hand, each of the multiple fins 56 does not need to contact the rotating body 583.

[0132] A flow path is formed between the plurality of fins 56 to allow gas to flow from the space in the +Z direction relative to the phosphor wheel 51A into the opening 533 when the phosphor wheel 51A rotates. In other words, a flow path is formed between adjacent pairs of the plurality of fins 56 to allow gas to flow from the rotation axis Rx side toward the outer peripheral edge of the substrate 53.

[0133] Balancer structure

[0134] The balancer 57A rotates together with the wheel 52A to correct the rotational balance of the wheel 52A. Figure 4 、 Figure 6 as well as Figure 7As shown, the balancer 57A is provided on the second surface 532 of the substrate 53. Specifically, the balancer 57A is arranged between two adjacent fins 56A and 56B among the plurality of fins 56 so as to contact the second surface 532. More specifically, the balancer 57A is arranged approximately in the center of the two fins 56A and 56B in the circumferential direction centered on the rotation axis Rx.

[0135] Specifically, the balancer 57A is fixed to the outer peripheral portion of the substrate 53 on the second surface 532. For example, the balancer 57A is arranged outside a concentric circle having a diameter of 80% of the diameter of the substrate 53, among the concentric circles having the same center as the substrate 53.

[0136] Such a balancer 57A may be exemplified by a metal body such as a copper plate fixed with an adhesive or the like, or a stack of balancer components having the same weight or a stack of balancer components having different weights.

[0137] Alternatively, the balancer 57A may be formed of an adhesive. Examples of such adhesives include photocurable adhesives such as ultraviolet curable adhesives, resin adhesives such as acrylic adhesives and epoxy adhesives, resin adhesives containing metals, brazing materials such as silver solder, and solder.

[0138] Furthermore, the balancer 57A may be a combination of the materials exemplified above.

[0139] Effects of the First Embodiment

[0140] The projector 1 according to the present embodiment described above provides the following effects.

[0141] The projector 1 includes a light source 32 , a wavelength conversion device 5A, an image generating device 24 , and a projection optical device 26 .

[0142] The light source 32 emits light that enters the wavelength conversion device 5A.

[0143] The image generating device 24 generates image light based on the light emitted from the wavelength conversion device 5A.

[0144] The projection optical device 26 projects the generated image light.

[0145] The wavelength converter 5A is a light converter that converts the wavelength of incident blue light to emit fluorescent light YL. The wavelength converter 5A includes a fluorescent wheel 51A as an optical wheel and a motor 58 that rotates the fluorescent wheel 51A.

[0146] The fluorescent wheel 51A includes a rotatable wheel 52A and a balancer 57A that rotates together with the wheel 52A and corrects the rotational balance of the wheel 52A. The wheel 52A includes a disc-shaped substrate 53 , a wavelength converter 54 , and a plurality of fins 56 .

[0147] The substrate 53 has a first surface 531 and a second surface 532 on the opposite side to the first surface 531 .

[0148] The wavelength converter 54 corresponds to a color changer. The wavelength converter 54 is disposed on the first surface 531 and emits light having a peak wavelength different from the peak wavelength of the incident light. In this embodiment, the wavelength converter 54 emits fluorescent light YL having a peak wavelength different from the peak wavelength of the incident blue light BLs.

[0149] The plurality of fins 56 are arranged on the second surface 532 and extend from the center side of the substrate 53 toward the outer peripheral edge of the substrate 53 .

[0150] The balancer 57A is disposed between two fins 56A and 56B facing each other among the plurality of fins 56 .

[0151] According to such a configuration, since the balancer 57A is provided on the base plate 53, the rotational balance of the wheel 52A can be corrected, thereby reducing the inertial load of the wheel 52A.

[0152] Furthermore, the balancer 57A is disposed between two opposing fins 56A and 56B among the plurality of fins 56 disposed on the second surface 532. This increases the area within the base plate 53 where the balancer 57A can be disposed, allowing the balancer 57A to be disposed at a position away from the rotation axis Rx of the base plate 53. Consequently, even with a light weight balancer 57A, the rotational balance of the base plate 53 can be corrected, and the influence of inertial load can be reduced.

[0153] Furthermore, the substrate 53 does not need to be provided with an outer peripheral portion, such as a flange, for arranging the balancer 57A. This allows the substrate 53 to be lightweight, and furthermore, the phosphor wheel 51A can be made smaller. Furthermore, if the diameter of the substrate having an outer peripheral portion without fins 56 is the same as the diameter of the substrate 53 having the balancer 57A arranged between the two fins 56A and 56B, the size of the fins 56 extending toward the outer peripheral edge of the substrate 53 can be increased in the latter substrate 53 of this embodiment. This improves the cooling efficiency of the substrate 53 having the wavelength converter 54 arranged thereon.

[0154] Furthermore, the inertial load of the phosphor wheel 51A can be reduced, making the phosphor wheel 51A lightweight. This allows the use of a low-torque motor as the motor 58, thereby reducing the cost of the motor 58 used in the wavelength converter 5A, which serves as the light conversion device. Furthermore, since the phosphor wheel 51A can be stably rotated, the projector 1 can be configured to stably project image light.

[0155] In the fluorescent substance wheel 51A, the balancer 57A is arranged at a portion on the outer peripheral edge side of the substrate 53 .

[0156] According to this structure, since the balancer 57A is provided on the outer peripheral side of the substrate 53 , the balancer 57A can be made lighter, and thus the phosphor wheel 51A can be made lighter, compared to a case where the balancer 57A is arranged on the center side of the substrate 53 .

[0157] In the fluorescent substance wheel 51A, the balancer 57A is fixed to the second surface 532 .

[0158] According to such a configuration, the balancer 57A disposed between the two fins 56A and 56B can be stably disposed on the base plate 53 .

[0159] In the phosphor wheel 51A, the color changer is a wavelength converter 54 that converts the wavelength of incident light.

[0160] With such a configuration, it is possible to configure the fluorescent body wheel 51A capable of achieving the above-mentioned effects.

[0161] Second embodiment

[0162] Next, a second embodiment of the present disclosure will be described.

[0163] The projector of this embodiment has the same structure as the projector 1 of the first embodiment, but the fixing position of the balancer between the two fins is different. In the following description, the same or substantially the same parts as those already described are denoted by the same reference numerals and the description thereof is omitted.

[0164] Schematic structure of projector and light source device

[0165] Figure 8 This is a top view of the wavelength conversion device 5B of this embodiment as viewed from the +Z direction. In other words, Figure 8 1 is a plan view showing the wavelength converter 5B viewed from the side opposite to the incident side of the blue light BLs serving as the excitation light.

[0166] The projector of this embodiment has a second device in place of the wavelength converter 5A. Figure 8The light source device of this embodiment has the same structure and function as the projector 1 of the first embodiment, except for the wavelength converter 5B shown. That is, the light source device of this embodiment has the same structure and function as the light source device 3 of the first embodiment, except for the wavelength converter 5B instead of the wavelength converter 5A.

[0167] Structure of wavelength conversion device

[0168] The wavelength converter 5B has the same structure and function as the wavelength converter 5A of the first embodiment, except for a different arrangement of the balancer. Specifically, the wavelength converter 5B of this embodiment has the same structure and function as the wavelength converter 5A, except for including a phosphor wheel 51B in place of the phosphor wheel 51A. Specifically, the wavelength converter 5B includes the phosphor wheel 51B and a motor 58. The wavelength converter 5B corresponds to a light converter.

[0169] Structure of phosphor wheel

[0170] The phosphor wheel 51B corresponds to an optical wheel and has the same function as the phosphor wheel 51A. The phosphor wheel 51B includes a wheel 52A and a balancer 57B. As described in the first embodiment, the wheel 52A includes a substrate 53, a wavelength converter 54, a reflector 55, and a plurality of fins 56.

[0171] The balancer 57B is made of the same material as the balancer 57A of the first embodiment and has the same structure as the balancer 57A.

[0172] The balancer 57A of the first embodiment is provided between two adjacent fins 56A and 56B on the second surface 532. Specifically, the balancer 57A is fixed to the second surface 532 between the two fins 56A and 56B and spaced apart from the fins 56A and 56B.

[0173] In contrast, the balancer 57B contacts at least one of the two adjacent fins 56A and 56B. In this embodiment, the balancer 57B is fixed to each of the two fins 56A and 56B by contacting them. That is, in addition to being fixed to the upstream fin 56A and the downstream fin 56B of the two fins 56A and 56B in the rotation direction RD of the wheel 52A, the balancer 57B is also fixed to the second surface 532. In addition, the upstream fin 56A is the fin of the two fins 56A and 56B located in the rotation direction RD. The downstream fin 56B is the fin of the two fins 56A and 56B located in the direction opposite to the rotation direction RD.

[0174] Shear force acting on the balancer

[0175] Figure 9: is a diagram illustrating the direction of the shear force acting on the sample SM fixed on the rotating substrate 53. Figure 9 The arrow in the diagram indicates the direction of the force, not the magnitude of the force.

[0176] Here, the shear force acting on the sample SM fixed to the second surface 532 of the substrate 53 will be described.

[0177] While the substrate 53 is rotating, shear forces in various directions act on the sample SM.

[0178] Specifically, when the rotation of the substrate 53 is started, a shear force corresponding to the inertial force F1 and the centrifugal force F3 that are caused by the change in the rotation speed of the substrate 53 acts on the sample SM. In other words, while the rotation speed of the wheel 52A is increasing, a shear force corresponding to the inertial force F1 in the rotation direction RD of the substrate 53 and the centrifugal force F3 that is directed radially outward of the substrate 53 acts on the sample SM.

[0179] When the substrate 53 rotates at a constant speed, only the shear force corresponding to the centrifugal force F3 acts on the sample SM.

[0180] When the rotation of the substrate 53 is decelerated, a shear force corresponding to the inertial force F2 and the centrifugal force F3 accompanying the change in the rotation speed of the substrate 53 acts on the sample SM. In other words, while the rotation speed of the substrate 53 is decelerated, a shear force corresponding to the inertial force F2 and the centrifugal force F3 in a direction opposite to the rotation direction RD of the substrate 53 acts on the sample SM.

[0181] Such a shear force also acts on the balancer fixed to the base plate 53 .

[0182] Therefore, the balancer 57B is fixed in contact with each of the upstream fin 56A and the downstream fin 56B.

[0183] Thus, even if an inertial force F1 in the rotation direction RD acts on the balancer 57B when the rotation of the base plate 53 starts, the balancer 57B can be supported by the upstream fins 56A. Even if an inertial force F2 in the direction opposite to the rotation direction RD acts on the balancer 57B when the rotation of the base plate 53 slows down, the balancer 57B can be supported by the downstream fins 56B.

[0184] The intersection angle between the fin extension direction and the tangent line

[0185] Figure 10 1 and 2 show an intersection angle α between an extension direction D1 of the upstream fin 56A toward the outer peripheral edge and a tangent line L1 to the substrate 53 at an intersection of the extension direction D1 of the fin 56A and the outer peripheral edge of the substrate 53 .

[0186] As described above, when the rotation of the wheel 52A starts, the inertial force F1 acts on the balancer 57B. Figure 10 As shown in FIG. 1 , assuming that the direction of extension of the upstream fin 56A, which contacts the balancer 57B, toward the outer peripheral edge is defined as extension direction D1, and the portion of the tangent line to the substrate 53 at the intersection of the extension direction D1 and the outer peripheral edge of the substrate 53 extending from the intersection toward the direction opposite to the rotational direction RD is defined as tangent line L1, the intersection angle α between the extension direction D1 and the tangent line L1 is preferably 90° or less. Specifically, the intersection angle α between the extension direction D1 and the tangent line L1, which extends in the direction opposite to the rotational direction RD, is preferably 90° or less, centered at the intersection.

[0187] Furthermore, the extending direction D1 is the extending direction of the fin 56A toward the outer peripheral edge side of the substrate 53 .

[0188] When the crossing angle α exceeds 90°, the surface of the upstream fin 56A facing the direction opposite to the rotation direction RD, that is, the surface in contact with the balancer 57B, faces the outside of the substrate 53. In this case, the fin 56A cannot easily withstand the inertial force F1 of the balancer 57B.

[0189] In contrast, when the crossing angle α is 90° or less, the upstream fins 56A can easily support the balancer 57B, which is subjected to the inertial force F1. In particular, when the crossing angle α is less than 90°, the gas flowing between the fins 56 can be easily discharged during the rotation of the phosphor wheel 51B. In this case, the cooling performance of the substrate 53 and the wavelength converter 54 can be improved compared to when the crossing angle α is 90° or greater.

[0190] Therefore, when the upstream fin 56A contacts the balancer 57B, the crossing angle α is preferably equal to or smaller than 90°, and more preferably smaller than 90°.

[0191] Figure 11 1 and 2 , which illustrate an intersection angle β between an extension direction D2 of the downstream fin 56B toward the outer peripheral edge and a tangent line L2 to the substrate 53 at an intersection of the extension direction D2 of the fin 56B and the outer peripheral edge of the substrate 53 .

[0192] As described above, when the rotation of the wheel 52A is decelerated, the inertial force F2 in the direction opposite to the rotation direction RD of the wheel 52A acts on the balancer 57B. Figure 11 As shown, when the extension direction of the fin 56B on the downstream side contacted by the balancer 57B toward the outer peripheral side is assumed to be the extension direction D2, and the tangent of the substrate 53 at the intersection position of the extension direction D2 of the fin 56B and the outer peripheral edge of the substrate 53 is the tangent L2, the intersection angle β between the extension direction D2 and the tangent L2 is preferably 90°.

[0193] Furthermore, the extending direction D2 is the extending direction of the fin 56B toward the outer peripheral edge side of the substrate 53 .

[0194] When the crossing angle β is smaller than 90°, the surface of the downstream fin 56B in the rotation direction RD, that is, the surface in contact with the balancer 57B, faces the outside of the substrate 53. In this case, the fin 56B is less likely to bear the inertial force F2 of the balancer 57B.

[0195] When the crossing angle β exceeds 90°, the balancer 57B, which is subjected to the inertial force F2, can be easily supported by the downstream fins 56B. However, fins 56B become upstream fins 56 relative to the downstream fins 56B. Furthermore, when the crossing angle β exceeds 90°, the fins 56 extend in the rotation direction RD as they move from the center of the substrate 53 toward the outer periphery. Therefore, when the crossing angle β of all fins 56 exceeds 90°, that is, when the extension direction D2 of each fin 56 is inclined toward the rotation direction RD, it becomes difficult to discharge the gas flowing between the fins 56 during the rotation of the wheel 52A. In this case, the cooling performance of the substrate 53 and the wavelength converter 54 is reduced.

[0196] In contrast, when the crossing angle β is 90°, the downstream fins 56B can easily support the balancer 57B, which is subjected to the inertial force F2. Furthermore, the gas flowing between the fins 56 when the wheel 52A rotates can be easily discharged, thereby maintaining high cooling performance for the substrate 53 and the wavelength converter 54.

[0197] Therefore, when the downstream fin 56B contacts the balancer 57B, the crossing angle β is preferably 90°.

[0198] Therefore, when the balancer 57B contacts the fin 56A located upstream of the balancer 57B in the rotation direction RD, the crossing angle α of the upstream fin 56A is preferably 90° or less. Furthermore, when the balancer 57B contacts the fin 56B located downstream of the balancer 57B in the direction opposite to the rotation direction RD, the crossing angle β of the downstream fin 56B is preferably 90°.

[0199] In the wavelength converter 5B of this embodiment, the balancer 57B contacts both the upstream fin 56A and the downstream fin 56B. Therefore, the intersection angles α and β of the fins 56 are preferably 90°. That is, in this embodiment, the intersection angle between the extending direction of the fin 56 and the tangent line to the wheel 52A at the intersection of the extending direction of the fin 56 and the outer peripheral edge of the wheel 52A is preferably 90°.

[0200] Furthermore, when the projector is powered on and the light source device is illuminated, for example, the rotation speed of the wheel 52A increases rapidly. This is because, in order to suppress a local temperature rise in the wavelength converter 54 caused by the incident excitation light, the wheel 52A must be rotated to move the irradiation spot of the excitation light in the wavelength converter 54. Therefore, when the wheel 52A starts rotating, a large shear force acts on the balancer.

[0201] On the other hand, when the projector's power is turned off, for example, and the light source device is turned off, the rotational speed of the wheel 52A slowly decreases. This is because, as long as the light source 32 is turned off, the excitation light does not enter the wavelength converter 54, suppressing the temperature rise of the wavelength converter 54. Therefore, there is no need to rapidly reduce the rotational speed of the wheel 52A by braking. Therefore, the shear force acting on the balancer during the deceleration of the wheel 52A is smaller than the shear force acting on the balancer during the initial rotation of the wheel 52A.

[0202] Therefore, it is preferable to prioritize suppressing separation of the balancer 57B by the upstream fins 56A and to arrange the plurality of fins 56 so that the crossing angle of the fins 56 is 90° or less.

[0203] Effects of the Second Embodiment

[0204] The projector according to the present embodiment described above has the following effects in addition to the same effects as those of the projector 1 according to the first embodiment.

[0205] In the fluorescent wheel 51B as the optical wheel, the balancer 57B is fixed to at least one of the two fins 56A and 56B sandwiching the balancer 57B. Specifically, the balancer 57B is fixed in contact with each of the two fins 56A and 56B.

[0206] As described above, when the fluorescent wheel 51B starts rotating and when the rotation is decelerated, a large force is applied in the tangential direction of the substrate 53. Therefore, in order to prevent the balancer from peeling off from the substrate 53, the balancer needs to be firmly fixed to the substrate.

[0207] By fixing the balancer 57B to the upstream fin 56A and the downstream fin 56B, even if a large shear force acts on the balancer 57B during the start-up and deceleration of the rotation of the fluorescent wheel 51B, the fins 56A and 56B can support the balancer 57B subjected to the shear force. This prevents the balancer 57B from falling off the substrate 53.

[0208] In the fluorescent substance wheel 51B, the balancer 57B is fixed to the fin 56A of the two fins 56A and 56B, which is arranged on the upstream side with respect to the fin 56B on the downstream side in the rotation direction RD of the wheel 52A.

[0209] As described above, the tangential force acting on the balancer during rotational startup is greater than the tangential force acting on the balancer during rotational deceleration. Therefore, by securing the balancer 57B to the fin 56A located upstream in the rotational direction RD of the wheel 52A, the upstream fin 56A can support the shear force acting on the balancer 57B. This effectively prevents the balancer 57B from falling off the base plate 53.

[0210] Furthermore, the balancer 57B is fixed to the upstream fin 56A and the downstream fin 56B. Therefore, when the rotation of the wheel 52A is decelerated, the fin 56B can bear the shear force applied to the balancer 57B. Therefore, the balancer 57B can be effectively prevented from falling off the base plate 53.

[0211] In the fluorescent material wheel 51B, assuming that the extension direction of the upstream fin 56A toward the outer peripheral edge is D1, and the portion of the tangent line to the substrate 53 at the intersection of the extension direction D1 and the outer peripheral edge of the substrate 53 extending from the intersection toward the side opposite to the rotation direction RD is tangent line L1, the intersection angle α between the extension direction D1 and the tangent line L1 is 90° or less. Preferably, the intersection angle α is less than 90°.

[0212] With this structure, the upstream fins 56A can easily support the balancer 57B, which is subjected to a shear force corresponding to the inertial force F1 when the phosphor wheel 51B rotates. This effectively prevents the balancer 57B from falling off the substrate 53. Furthermore, when the intersection angle α is less than 90°, the gas flowing between the fins 56 during the rotation of the phosphor wheel 51B can be further discharged outside the phosphor wheel 51B compared to when the intersection angle α is 90°. This improves the cooling performance of the substrate 53 and the wavelength converter 54.

[0213] In the fluorescent wheel 51B, the intersection angle between the outer peripheral extension direction of the fin 56 to which the balancer 57B is fixed and the tangent line to the substrate 53 at the intersection of the outer peripheral extension direction of the fin 56 and the outer peripheral edge of the substrate 53 is 90°. In other words, among the multiple fins 56, the intersection angle α of the upstream fin 56A and the downstream fin 56B sandwiching the balancer 57B may be 90°, and the intersection angle β of the downstream fin 56B may be 90°. Alternatively, the intersection angles of the multiple fins 56 may be 90°.

[0214] With this structure, the balancer 57B contacts the upstream fins 56A, and the intersection angle α of the upstream fins 56A is 90°. This allows the upstream fins 56A to easily support the balancer 57B, which is subject to shearing forces when the phosphor wheel 51B starts rotating. Furthermore, the balancer 57B contacts the downstream fins 56B, and the intersection angle β of the downstream fins 56B is 90°. This allows the downstream fins 56B to easily support the balancer 57B, which is subject to shearing forces when the phosphor wheel 51B decelerates rotating. This effectively prevents the balancer 57B from detaching from the substrate 53.

[0215] Furthermore, since the intersection angles α and β are 90°, the gas flowing between the fins 56 during the rotation of the phosphor wheel 51B can be discharged to the outside of the phosphor wheel 51B, compared to a case where the intersection angles α and β exceed 90°. This improves the cooling performance of the substrate 53 and the wavelength converter 54.

[0216] Variation of the Second Embodiment

[0217] In the wavelength converter 5B of the second embodiment, the balancer 57B is fixed to each of the upstream fin 56A and the downstream fin 56B. However, this is not limiting. The balancer may be in contact with one of the upstream fin 56A and the downstream fin 56B relative to the balancer in the rotational direction RD, but not in contact with the other fin.

[0218] Figure 12 This is a diagram of a phosphor wheel 51C of a wavelength conversion device 5C according to a first modified example of the wavelength conversion device 5B of the second embodiment, as viewed from the −Z direction. Figure 13 This is a diagram of a phosphor wheel 51D of a wavelength conversion device 5D according to a second modified example of the wavelength conversion device 5B of the second embodiment, as viewed from the −Z direction.

[0219] For example, Figure 12 The phosphor wheel 51C of the wavelength conversion device 5C shown has the same structure and function as the phosphor wheel 51B of the wavelength conversion device 5B, except that the phosphor wheel 51C includes a balancer 57C instead of the balancer 57B. Figure 13 The phosphor wheel 51D of the wavelength converter 5D shown has the same structure and function as the phosphor wheel 51B of the wavelength converter 5B, except that it includes a balancer 57D instead of the balancer 57B. Although not shown, the wavelength converters 5C and 5D each include a motor 58, which rotates the phosphor wheels 51C and 51D.

[0220] The balancers 57C and 57D are made of the same material as the balancers 57A and 57B, and are arranged between two fins 56 adjacent to each other in the rotation direction RD, similarly to the balancers 57A and 57B, and are fixed to the second surface 532 .

[0221] Figure 12 The illustrated balancer 57C is fixed in contact with only the upstream fin 56A and does not contact the downstream fin 56B.

[0222] In the wavelength converter 5C, as described above, the intersection angle α of the upstream fins 56A is preferably 90° or less, and the intersection angle α of each fin 56 is preferably 90° or less. Furthermore, in the wavelength converter 5C, the intersection angle α of the upstream fins 56A is more preferably less than 90°, and the intersection angle α of each fin 56 is more preferably less than 90°.

[0223] Figure 13 The illustrated balancer 57D does not contact the upstream fin 56A but contacts and is fixed to the downstream fin 56B.

[0224] In the wavelength conversion device 5D, as described above, the crossing angle β of the downstream fins 56B is preferably 90°, and the crossing angle β of each fin 56 is preferably 90°.

[0225] Third embodiment

[0226] Next, a third embodiment of the present disclosure will be described.

[0227] The projector of this embodiment has the same structure as the projector 1 of the first embodiment, but the shape of the fins of the phosphor wheel is different. In the following description, the same or substantially the same parts as those already described are denoted by the same reference numerals and their description is omitted.

[0228] Schematic structure of projector and light source device

[0229] Figure 14 It is a perspective view showing a wavelength conversion device 5E according to this embodiment.

[0230] The projector of this embodiment has a second device in place of the wavelength converter 5A. Figure 14 In other words, the light source device of this embodiment has the same structure and function as the light source device 3 of the first embodiment, except that the wavelength converter 5E is replaced by the wavelength converter 5A.

[0231] Structure of wavelength conversion device

[0232] The wavelength converter 5E has the same structure and function as the wavelength converter 5A of the first embodiment, except that the fins extend from the second surface of the wheel. Specifically, the wavelength converter 5E of this embodiment has the same structure and function as the wavelength converter 5A, except that it includes a phosphor wheel 51E in place of the phosphor wheel 51A. Specifically, the wavelength converter 5E includes the phosphor wheel 51E and a motor 58. The wavelength converter 5E corresponds to a light converter.

[0233] Structure of phosphor wheel

[0234] The fluorescent substance wheel 51E includes the wheel 52E instead of the wheel 52A and further includes the balancer 57B. Alternatively, the fluorescent substance wheel 51E may include the balancer 57C or the balancer 57D instead of the balancer 57B.

[0235] The wheel 52E has the same structure and function as the wheel 52A of the first embodiment, except that it includes a plurality of fins 59 instead of the plurality of fins 56. That is, the wheel 52E includes a substrate 53, a wavelength converter 54, a reflector 55, and a plurality of fins 59.

[0236] Multiple fin structure

[0237] The plurality of fins 59 have the same structure and function as the plurality of fins 56 of the first embodiment, except for the inclusion of the enlarged portion 591. Specifically, the plurality of fins 59 are integrally provided on the second surface 532 and are arranged at substantially equal intervals along the periphery of the opening 533 of the substrate 53. The plurality of fins 59 extend from the portion on the rotation axis Rx side toward the outer periphery of the substrate 53.

[0238] The plurality of fins 59 include two fins 59A and 59B sandwiching the balancer 57B. The fin 59A is located upstream of the balancer 57B in the rotation direction RD of the substrate 53 , and the fin 59B is located downstream of the balancer 57B in the direction opposite to the rotation direction RD.

[0239] The plurality of fins 59 each have a second end portion 562, Figure 14 In addition to the first end portion 561 and the connecting portion 563 (not shown), the embodiment further includes an enlarged portion 591 .

[0240] The expanded portion 591 is the portion where the fin thickness increases as it approaches the second surface 532 on which the fin 59 is provided. Specifically, the expanded portion 591 is the portion where the dimension of the fin 59 in the rotational direction RD increases as it approaches the second surface 532. The outer surface of the expanded portion 591 is a planar, inclined surface that is inclined relative to the second surface 532. In other words, the outer surface of the expanded portion 591 is a planar, C-surface.

[0241] The expanded portion 591 is provided on the surface of at least one of the fins 59A and 59B that faces the balancer 57B. In this embodiment, the balancer 57B is secured to the fin 59A using a light-curing adhesive such as an ultraviolet-curing adhesive while in contact with the expanded portion 591 of the upstream fin 59A. Furthermore, the balancer 57B is secured to the fin 59B using a light-curing adhesive such as an ultraviolet-curing adhesive while in contact with the expanded portion 591 of the downstream fin 59B. Furthermore, as described above, the balancer 57B is secured to the second surface 532.

[0242] In this embodiment, the expanded portion 591 is provided not only on the surface of the upstream fin 59A and the surface of the downstream fin 59B facing the balancer 57B, but also on the surface of each fin 59 facing the rotational direction RD and the surface facing the direction opposite to the rotational direction RD. That is, in the wavelength converter 5E of this embodiment, the expanded portion 591 is provided on the surface of each of the plurality of fins 59 facing the rotational direction RD and the surface facing the direction opposite to the rotational direction RD.

[0243] However, the present invention is not limited thereto. The fin 59A may include the enlarged portion 591 only on the surface facing the balancer 57B, and the fin 59B may include the enlarged portion 591 only on the surface facing the balancer 57B.

[0244] Effects of the Third Embodiment

[0245] The projector according to the present embodiment described above has the following effects in addition to the same effects as those of the projector according to the second embodiment.

[0246] In the fluorescent wheel 51E as an optical wheel, the balancer 57B is fixed with a photocurable adhesive in contact with at least one of the two fins 59A and 59B. The at least one fin has an enlarged portion 591 that increases in thickness toward the second surface 532 and contacts the balancer 57B.

[0247] In the phosphor wheel 51E of this embodiment, the balancer 57B is fixed with a photocurable adhesive while in contact with each of the two fins 59A and 59B. Each fin 59A and 59B has an expanded portion 591, which increases in thickness as it approaches the second surface 532 and contacts the balancer 57B. At least a portion of the balancer 57B contacts the expanded portion 591 of the fin 59A, while at least another portion of the balancer 57B contacts the expanded portion 591 of the fin 59B.

[0248] With this structure, when applying the photocurable adhesive that secures the balancer 57B to the second surface 532 and the fins 59A and 59B, the thickness of the photocurable adhesive can be made substantially uniform. Therefore, when curing the photocurable adhesive, light can be applied throughout the adhesive. This facilitates curing of the photocurable adhesive, preventing the formation of uncured areas in the adhesive and effectively preventing the balancer 57B from detaching from the substrate 53.

[0249] In the fluorescent body wheel 51E, the outer surface of the enlarged portion 591 is formed in one of a curved surface shape and a flat surface shape. In this embodiment, the outer surface of the enlarged portion 591 is formed in a flat surface shape.

[0250] This structure allows the thickness of the photocurable adhesive applied to the enlarged portion 591 to be more uniform, compared to a case where the outer surface of the enlarged portion 591 is formed in a stepped shape, and allows light to spread throughout the photocurable adhesive. This effectively prevents the formation of uncured areas in the photocurable adhesive, and more effectively prevents the balancer 57B from detaching from the substrate 53.

[0251] In addition, the wavelength conversion device 5E has a balancer 57B that contacts the upstream fin 59A and the downstream fin 59B respectively, and the multiple fins 59 respectively have an enlarged portion 591, which is respectively arranged on the surface of each fin 59 facing the rotation direction RD and the surface facing the direction opposite to the rotation direction RD.

[0252] However, the invention is not limited thereto, and the enlarged portion 591 may be provided on the surface of one of the fins 59A and 59B that faces the balancer 57B.

[0253] Furthermore, the wavelength converter 5E may include at least one of the baluns 57A, 57C, and 57D in place of or in addition to the balun 57B. When the wavelength converter 5E includes the balun 57C in contact with the upstream fin 59A, the enlarged portion 591 may be provided only on the surface of the fin 59A upstream of the balun 57C among the plurality of fins 59, which faces the balun 57C, or may be provided on each fin 59. When the wavelength converter 5E includes the balun 57D in contact with the downstream fin 59B, the enlarged portion 591 may be provided only on the surface of the fin 59B downstream of the balun 57D among the plurality of fins 59, which faces the balun 57D, or may be provided on each fin 59.

[0254] Variation of the third embodiment

[0255] Figure 151 is a perspective view showing a modification of the wavelength conversion device 5E according to the third embodiment, and is a perspective view showing an enlarged portion 592 which is a modification of the enlarged portion 591 .

[0256] The expanded portion 591 is a portion of the fin 59 where the fin thickness increases toward the second surface 532. The outer surface of the expanded portion 591 is a planar inclined surface that is inclined relative to the second surface 532. However, the present invention is not limited thereto.

[0257] For example, Figure 15 As shown, the multiple fins 59 of the phosphor wheel 51E of the wavelength conversion device 5E may include an enlarged portion 592 instead of the enlarged portion 591. The outer surface of the enlarged portion 592, which faces the adjacent fin 59, is formed into a curved surface. In other words, the outer surface of the enlarged portion 592 is a curved rounded surface. Specifically, the outer surface of the enlarged portion 592 is a concave curved surface.

[0258] Even when the balancer is set in a manner that contacts at least one of the upstream fin 59A and the downstream fin 59B having the curved expansion portion 592, the same effect can be achieved as when the balancer is set in a manner that contacts at least one of the fins 59A and 59B having the planar expansion portion 591.

[0259] Fourth embodiment

[0260] Next, a fourth embodiment of the present disclosure will be described.

[0261] The projector of this embodiment has the same structure as the projector of the first embodiment, but differs in that the substrate of the phosphor wheel has a stepped portion, and the balancer is disposed on the stepped portion. In the following description, parts that are identical or substantially identical to parts already described are denoted by the same reference numerals, and their description will be omitted.

[0262] Structure of projector and light source device

[0263] Figure 16 It is a perspective view showing a wavelength conversion device 5F according to this embodiment.

[0264] The projector of this embodiment has a second device in place of the wavelength converter 5A. Figure 16 The projector 1 of the first embodiment has the same structure and function as the projector 1 of the first embodiment, except for the wavelength converter 5F shown. That is, the light source device of this embodiment has the same structure and function as the light source device 3 of the first embodiment, except for the wavelength converter 5F instead of the wavelength converter 5A.

[0265] Structure of wavelength conversion device

[0266] The wavelength converter 5F has the same structure and function as the wavelength converter 5A of the first embodiment, except that its substrate includes a stepped portion that prevents the adhesive from moving toward the rotation axis Rx. Specifically, the wavelength converter 5F of this embodiment has the same structure and function as the wavelength converter 5A, except that it includes a phosphor wheel 51F in place of the phosphor wheel 51A. The wavelength converter 5F corresponds to a light converter.

[0267] Structure of phosphor wheel

[0268] The fluorescent wheel 51F corresponds to an optical wheel. The fluorescent wheel 51F includes a wheel 52F and a balancer 57B. Alternatively, the fluorescent wheel 51F may include at least one of the balancers 57A, 57C, and 57D instead of or in addition to the balancer 57B.

[0269] The wheel 52F has the same structure and function as the wheel 52A, except that it includes a substrate 53F instead of the substrate 53. Specifically, the wheel 52F includes the substrate 53F, a wavelength converter 54, a reflector 55, and a plurality of fins 56. Furthermore, the wheel 52F may include a plurality of fins 59 having enlarged portions 591 and 592 as shown in the third embodiment, instead of the plurality of fins 56. Furthermore, the two fins 56A and 56B sandwiching the balancer 57B among the plurality of fins 56 may also include an enlarged portion similar to the enlarged portions 591 and 592.

[0270] Substrate structure

[0271] The substrate 53F has the same structure and function as the substrate 53 except that it also has the step portion 535. Figure 16 In addition to the first surface 531 , the opening 533 , and the protrusion 534 , which are not shown in the figure, the structure further includes a plurality of step portions 535 .

[0272] The multiple steps 535 are recessed portions provided on the second surface 532 between adjacent two of the multiple fins 56 and on the outer periphery of the substrate 53F. Specifically, the thickness of the substrate 53F at the step 535 is smaller than the thickness of the substrate 53F at portions other than the step 535. In this embodiment, the step 535 is formed continuously to the outer periphery of the substrate 53F. However, this is not limiting, and the step 535 may also be a recessed portion provided between the inner periphery and the outer periphery of the substrate 53F.

[0273] A balancer is provided on at least one of the plurality of stepped portions 535. For example, when the fluorescent wheel 51F includes the balancer 57B, the balancer 57B is disposed on the stepped portion 535 so as to contact the upstream fin 56A and the downstream fin 56B, respectively, and is fixed to the fins 56A and 56B and the stepped portion 535 using a light-curing adhesive or the like.

[0274] Effects of the Fourth Embodiment

[0275] The projector according to the present embodiment described above has the following effects in addition to the same effects as those of the second embodiment.

[0276] In the phosphor wheel 51F serving as an optical wheel, the substrate 53F has a stepped portion 535 provided on the outer peripheral edge of the second surface 532. The thickness of the substrate 53F at the stepped portion 535 is smaller than the thickness of the substrate 53F at portions other than the stepped portion 535. The balancer included in the phosphor wheel 51F is fixed to the stepped portion 535 with a photocurable adhesive.

[0277] This structure can prevent the photocurable adhesive from flowing toward the center of the substrate 53F before curing, thereby preventing poor curing of the photocurable adhesive. This can prevent a decrease in the fixing strength of the balancer to the substrate 53F. Furthermore, the photocurable adhesive can be prevented from moving toward the center of the substrate 53F, thereby preventing positional deviation of the balancer.

[0278] Fifth embodiment

[0279] Next, a fifth embodiment of the present disclosure will be described.

[0280] The projector of this embodiment has the same structure as the projector 1 of the first embodiment, but differs in that it includes a color wheel as a light conversion device. In the following description, parts that are the same or substantially the same as those already described are denoted by the same reference numerals, and description thereof is omitted.

[0281] Projector structure

[0282] Figure 17 1 is a schematic diagram showing the configuration of an image projection device 7 included in a projector 1G according to this embodiment.

[0283] The projector 1G of this embodiment has a Figure 17 Except for the image projection device 7 shown, the projector 1 has the same structure and function as the projector 1 of the first embodiment.

[0284] Structure of image projection device

[0285] The image projection device 7 projects image light corresponding to input image information, similarly to the image projection device 2 of the first embodiment. The image projection device 7 includes a light source 71, a light conversion device 8, a first reflecting member 72, a second reflecting member 73, an image generating device 74, and a projection optical device 26.

[0286] The light source 71 emits white illumination light toward the light conversion device 8. The light source 71 may have the same structure as the light source device 3 described in the first to fourth embodiments, or may have another structure.

[0287] The first reflecting member 72 and the second reflecting member 73 are reflecting members that guide the light emitted from the light conversion device 8 to the image generating device 74 .

[0288] Image generation device 74 modulates the light incident from second reflective member 73 to generate image light. Red light, green light, and blue light sequentially enter image generation device 74 from light conversion device 8 via reflective members 72 and 73. Image generation device 74 generates a red image during the period of red light incident, a green image during the period of green light incident, and a blue image during the period of blue light incident. In this embodiment, image generation device 74 is comprised of a DMD (Digital Micromirror Device).

[0289] The projection optical device 26 projects the image generated by the image generating device 74 .

[0290] Structure of the light conversion device

[0291] Figure 18 It is a plan view of the light conversion device 8 as viewed from the light incident side.

[0292] The light conversion device 8 converts the incident light. Specifically, the light conversion device 8 emits light having characteristics different from those of the incident light. In this embodiment, the light conversion device 8 emits light having a wavelength band different from that of the illumination light incident from the light source 71. Specifically, the light conversion device 8 sequentially emits red light, green light, and blue light from the incident illumination light.

[0293] Such a light conversion device 8 includes a color wheel 81 and a motor 58 that rotates the color wheel 81 .

[0294] The structure of the color wheel

[0295] The color wheel 81 is an optical wheel that is rotated by the motor 58 and sequentially emits red, green, and blue light from the illumination light incident from the light source 71. The color wheel 81 includes at least one of the balancers 57A, 57B, 57C, and 57D and a wheel 82.

[0296] The wheel 82 is rotatable by the motor 58. The wheel 82 has the same structure and function as the wheel 52A, except that it includes a wavelength shifter 84 instead of the wavelength converter 54 of the first embodiment. Specifically, the wheel 82 includes a substrate 53, a wavelength shifter 84, a reflector 55, and a plurality of fins 56.

[0297] In addition, the wheel 82 may include a plurality of fins 59 each having enlarged portions 591 and 592 instead of the plurality of fins 56. In addition, the base plate 53 included in the wheel 82 may not include the opening 533.

[0298] The wavelength shifter 84 corresponds to a color light shifter and emits light having a peak wavelength different from the peak wavelength of the incident light. In other words, the wavelength shifter 84 emits light having a wavelength band different from the wavelength band of the incident light.

[0299] Like the wavelength converter 54, the wavelength changer 84 is annularly configured with the rotation axis Rx of the wheel 82 as its center. It is fixed to the first surface 531 of the substrate 53, located outside the opening 533. The wavelength changer 84 is divided into three sections circumferentially with the rotation axis Rx as its center. Specifically, the wavelength changer 84 has three wavelength change regions 841 equidistantly spaced about the rotation axis Rx. The three wavelength change regions 841 are connected in series, forming an annular configuration for the wavelength changer 84.

[0300] The three wavelength changing regions 841 include a red region 841R, a green region 841G, and a blue region 841B. The color wheel 81 is rotated by the motor 58, so that illumination light emitted from the light source 71 is incident on the red region 841R, the green region 841G, and the blue region 841B in sequence.

[0301] The red region 841R is a color filter that absorbs green and blue light in the incident illumination light and transmits red light. The red light that has passed through the red region 841R is reflected by the reflection unit 55 , passes through the red region 841R again, and is emitted from the color wheel 81 .

[0302] The green region 841G is a color filter that absorbs red and blue light in the incident illumination light and transmits green light. The green light that has passed through the green region 841G is reflected by the reflection unit 55 , passes through the green region 841G again, and is emitted from the color wheel 81 .

[0303] The blue region 841B is a color filter that absorbs red and green light in the incident illumination light and transmits blue light. The blue light that has passed through the blue region 841B is reflected by the reflection unit 55 , passes through the blue region 841B again, and is emitted from the color wheel 81 .

[0304] As described above, the wavelength shifter 84 is a color filter that sequentially emits colored light of a plurality of different wavelength bands.

[0305] Effects of the Fifth Embodiment

[0306] The projector 1G including such a light conversion device 8 produces the same effects as those of the projector 1 according to the first embodiment.

[0307] The color wheel 81 as an optical wheel includes a rotatable wheel 82 and a balancer that rotates together with the wheel 82 and corrects the rotational balance of the wheel 82. As the balancer, at least one of the balancers 57A, 57B, 57C, and 57D can be used.

[0308] The wheel 82 includes a disk-shaped substrate 53, a wavelength changing body 84, and a plurality of fins.

[0309] As described above, the substrate 53 has the first surface 531 and the second surface 532 on the opposite side to the first surface 531 .

[0310] The wavelength shifter 84 corresponds to a color light shifter and is disposed on the first surface 531. White light enters the wavelength shifter 84 as light in the first wavelength band. The wavelength shifter 84 emits color light in wavelength bands different from the wavelength band of the white light. That is, when the light in the first wavelength band enters the wavelength shifter 84, the wavelength shifter 84 sequentially emits red light, green light, and blue light. The red light, green light, and blue light each correspond to light having a peak wavelength different from the peak wavelength of the incident light; in other words, they correspond to light in wavelength bands different from the wavelength band of the incident light.

[0311] As described above, the plurality of fins 56 are arranged on the second surface 532, and extend from the center portion of the substrate 53 toward the outer peripheral edge of the substrate 53. The same applies to the case where the plurality of fins 59 are used.

[0312] The balancer 57A is arranged between two fins facing each other among the plurality of fins. The same applies to the case where the balancers 57B, 57C, and 57D are used.

[0313] According to such a configuration, for example, when the balancer 57A is used, the balancer 57A is provided on the base plate 53 , so that the rotational balance of the wheel 82 can be corrected. Therefore, the inertial load of the wheel 82 can be reduced.

[0314] Furthermore, for example, when fins 56 are used, the balancer 57A is disposed between two opposing fins 56 among the plurality of fins 56 disposed on the second surface 532. This increases the area within the substrate 53 where the balancer 57A can be disposed, allowing the balancer 57A to be disposed at a position away from the rotation axis Rx of the substrate 53. Thus, even with a light weight balancer 57A, the rotational balance of the substrate 53 can be corrected, and the influence of inertial load can be reduced.

[0315] In addition, there is no need to provide a peripheral portion on the outer peripheral portion of the substrate 53 that is provided with a balancer but not with fins. Therefore, the substrate 53 can be made lighter, and furthermore, in addition to being able to make the color wheel 81 lighter, the color wheel 81 can also be miniaturized. Moreover, when the diameter of the substrate provided with the above-mentioned peripheral portion is the same as the diameter of the substrate 53 provided with the balancer 57A between the two fins 56, in the latter substrate 53, the size of the fins 56 extending toward the outer peripheral edge of the substrate 53 can be increased. Each wavelength change region 841 absorbs a portion of the incident light and thus generates heat. Such heat is transferred to the fins 56 via the substrate 53 and dissipated, so by increasing the size of the fins 56, the cooling efficiency of the substrate 53 provided with the wavelength changer 84 can be improved.

[0316] This effect is also achieved when the color wheel 81 uses the balancers 57B, 57C, and 57D, and when the color wheel 81 uses the fins 59 .

[0317] On the other hand, when the balancers 57B, 57C, and 57D are used as the color wheel 81, the same effects as those of the projector according to the second embodiment can be achieved.

[0318] Furthermore, when the color wheel 81 employs a plurality of fins 59 , the same effects as those of the projector according to the third embodiment can be achieved.

[0319] Furthermore, when the color wheel 81 includes a substrate 53F instead of the substrate 53 , the same effects as those of the projector according to the fourth embodiment can be achieved.

[0320] In the color wheel 81 , the wavelength shifter 84 is a color light shifter, specifically, a color filter that emits light in a predetermined wavelength band among incident light.

[0321] With such a configuration, it is possible to configure the color wheel 81 that can exhibit the effects of the above-mentioned optical wheel.

[0322] Variations of the Embodiments

[0323] The present disclosure is not limited to the above-described embodiments, and modifications and improvements within the scope that can achieve the object of the present disclosure are included in the present disclosure.

[0324] In the above-described embodiments, the balancer 57A is fixed to the second surface 532, and the balancer 57B is fixed to the second surface 532, the upstream fins 56A and 59A, and the downstream fins 56B and 59B, respectively. Furthermore, the balancer 57C is fixed to the second surface 532 and the upstream fins 56A and 59A, respectively, and the balancer 57D is fixed to the second surface 532 and the downstream fins 56B and 59B, respectively. However, this is not limiting, and when the balancer is fixed to the fins, it is not necessary to fix it to the second surface 532.

[0325] In the first to fourth embodiments described above, the wavelength converters 5A, 5B, 5C, 5D, 5E, and 5F, serving as light converters, are reflective-type wavelength converters that have a reflective portion 55 and emit fluorescence in a direction opposite to the incident direction of the excitation light. In the fifth embodiment described above, the light converter 8 is a reflective-type light converter that has a reflective portion 55 and emits red, green, and blue light in directions opposite to the incident direction of the white light. However, this is not limiting. The light converter of the present disclosure may also be a transmissive-type light converter that emits wavelength-modified or converted light along the incident direction of the light. For example, the wavelength converters 5A, 5B, 5C, 5D, 5E, and 5F of the first to fourth embodiments may be configured using a light-transmitting substrate 53 without the reflective portion 55. Furthermore, in the light converter 8 of the fifth embodiment, the wavelength shifter 84 may be disposed outside the substrate 53 as viewed from the incident side of the white light, without the reflective portion 55 disposed on the substrate 53.

[0326] In the first to fourth embodiments described above, the wavelength converters 5A, 5B, 5C, 5D, 5E, and 5F, serving as light conversion devices, are employed in the light source device 3 included in the projector. In the fifth embodiment described above, the light conversion device 8 is employed in the image projection device 7 included in the projector 1G. However, this is not limiting, and the light conversion device disclosed herein may also be employed in electronic devices other than projectors, such as lighting devices.

[0327] In the first to fourth embodiments described above, the projector includes three light modulators 243R, 243G, and 243B. However, the present disclosure is not limited thereto and can be applied to a projector including two or fewer or four or more light modulators.

[0328] In the fifth embodiment described above, the projector 1G includes one image generating device 74. That is, the projector 1G includes one light modulator. However, the present invention is not limited thereto, and the projector 1G may include a plurality of light modulators.

[0329] In the above-mentioned first to fourth embodiments, Figure 1As shown, the image projection device 2 is configured in a substantially L-shape. However, this is not limiting, and the image projection device 2 may also be configured in a substantially U-shape, for example. That is, the structure of the image projection device constituting the projector is not limited to the above-described structure. This also applies to the projector 1G of the fifth embodiment.

[0330] In the first to fourth embodiments described above, the light modulator 243 included in the image generating device 24 is constructed from a transmissive liquid crystal panel with different light incident and light exit surfaces. However, this is not limiting. The light modulator constituting the image generating device 24 may also be constructed from a reflective liquid crystal panel with the same light incident and light exit surfaces. Furthermore, light modulators other than liquid crystals, such as those using micromirrors such as DMDs, may also be used, as long as the light modulator can modulate an incident light beam to form an image corresponding to the image information.

[0331] In the fifth embodiment described above, the image generating device 74 is configured by a DMD. However, the present invention is not limited thereto, and the image generating device 74 may be configured to include at least one liquid crystal panel.

[0332] Summary of the Disclosure

[0333] The following is a summary of the present disclosure.

[0334] Note 1

[0335] An optical wheel, characterized in that the optical wheel comprises: a rotatable wheel; and a balancer that rotates with the wheel to correct the rotational balance of the wheel, the wheel comprising: a disc-shaped substrate having a first surface and a second surface on the side opposite to the first surface; a color changer that is arranged on the first surface and emits light with a peak wavelength different from the peak wavelength of the incident light; and a plurality of fins that are arranged on the second surface and extend from a portion on the center side of the substrate toward the outer peripheral edge of the substrate, the balancer being arranged between two opposing fins among the plurality of fins.

[0336] According to this structure, since the balancer is provided on the base plate, the rotational balance of the wheel can be corrected, thereby reducing the inertial load of the wheel.

[0337] Furthermore, the balancer is positioned between two opposing fins among the plurality of fins arranged on the second surface. This expands the area on the substrate where the balancer can be positioned, allowing the balancer to be positioned away from the substrate's rotational axis. This allows the substrate's rotational balance to be corrected even with a light balancer, while also reducing the effects of inertial loads.

[0338] Furthermore, it is not necessary to provide an outer peripheral portion on the outer peripheral portion of the substrate where the balancer is arranged but no fins are arranged. In other words, it is not necessary to provide an outer peripheral portion such as a flange for arranging the balancer on the substrate.

[0339] This allows for a lighter substrate, and furthermore, not only a lighter optical wheel but also a smaller optical wheel. Furthermore, if the diameter of the substrate with the aforementioned peripheral portion is the same as the diameter of the substrate with the balancer positioned between the two fins, the size of the fins extending toward the outer periphery of the substrate can be increased in the latter substrate. This improves the cooling efficiency of the substrate with the color changer.

[0340] Note 2

[0341] The optical wheel according to Supplementary Note 1, wherein the balancer is arranged on an outer peripheral edge side of the substrate.

[0342] According to this structure, the balancer is provided on the outer peripheral side of the substrate. Therefore, compared with the case where the balancer is arranged on the center side of the substrate, the balancer can be made lighter, thereby achieving lighter optical wheels and reducing inertial load.

[0343] Note 3

[0344] The optical wheel according to Supplementary Note 1 or 2, characterized in that the balancer is fixed to at least one of the two fins.

[0345] Here, when the optical wheel starts rotating or decelerates, a large force is applied in the tangential direction of the substrate. Therefore, in order to prevent the balancer from peeling off from the substrate, the balancer needs to be firmly fixed to the substrate.

[0346] In this regard, since the balancer is fixed to the at least one fin, even if a large shear force acts on the balancer during at least one of the start-up and deceleration of the optical wheel, the fin can support the balancer subjected to the shear force. Therefore, it is possible to prevent the balancer from falling off the substrate.

[0347] Note 4

[0348] The optical wheel according to Supplementary Note 3, wherein the balancer is fixed to a fin of the two fins that is arranged on an upstream side relative to one fin in the rotation direction of the wheel.

[0349] With this structure, the tangential force acting on the balancer during rotational startup is greater than the tangential force acting on the balancer during rotational deceleration. Therefore, by securing the balancer to the upstream fin of the two fins sandwiching the balancer in the wheel's rotational direction, the upstream fin can support the balancer under shear force. This effectively prevents the balancer from falling off the baseplate.

[0350] Note 5

[0351] The optical wheel according to Note 4 is characterized in that the intersection angle between the extension direction of the upstream fin to the outer peripheral side and the tangent part is less than 90°, and the tangent part is a tangent part of the tangent of the substrate at the intersection position of the extension direction of the upstream fin to the outer peripheral side and the outer peripheral edge of the substrate, extending from the intersection position to the side opposite to the rotation direction.

[0352] According to this structure, the balancer subjected to centrifugal force when the optical wheel rotates can be easily supported by the upstream fins, thereby more effectively preventing the balancer from falling off the substrate.

[0353] Note 6

[0354] The optical wheel according to Note 3 is characterized in that the intersection angle between the extension direction of the at least one fin toward the outer peripheral side and the tangent of the substrate at the intersection position of the extension direction of the at least one fin toward the outer peripheral side and the outer peripheral edge of the substrate is 90°.

[0355] With this structure, the balancer is fixed to at least one of the two opposing fins. Therefore, by setting the intersection angle to 90°, the fin to which the balancer is fixed can easily support the balancer under shear forces applied during at least one of the optical wheel's rotational start-up and rotational deceleration. For example, if the balancer is fixed to the upstream fin in the wheel's rotational direction, the upstream fin can support the balancer under shear forces applied during rotational start-up. Alternatively, if the balancer is fixed to the downstream fin in the wheel's rotational direction, the downstream fin can support the balancer under shear forces applied during rotational deceleration. This effectively prevents the balancer from detaching from the base plate.

[0356] Note 7

[0357] The optical wheel according to any one of Notes 3 to 6 is characterized in that the balancer is fixed by a photocurable adhesive in a state of being in contact with the at least one fin, and the at least one fin has an enlarged portion in which the fin thickness increases as it approaches the second surface and is in contact with the balancer.

[0358] This structure allows for a substantially uniform thickness of the photocurable adhesive used to secure the balancer to the fins when applied. Consequently, light can be applied to the adhesive during curing. This facilitates curing of the adhesive, preventing the formation of uncured areas in the adhesive and effectively preventing the balancer from detaching from the substrate.

[0359] Note 8

[0360] The optical wheel according to Supplementary Note 7, wherein the outer surface of the enlarged portion is formed in one of a curved surface shape and a flat surface shape.

[0361] This structure allows light to penetrate the photocurable adhesive provided in the enlarged portion more effectively than when the outer surface of the enlarged portion is formed in a stepped shape. Therefore, it is possible to effectively prevent the generation of uncured areas in the photocurable adhesive and more effectively prevent the balancer from detaching from the substrate.

[0362] Note 9

[0363] The optical wheel according to any one of Supplementary Notes 1 to 8, wherein the balancer is fixed to the second surface.

[0364] According to such a configuration, the balancer disposed between the two fins can be stably disposed on the substrate.

[0365] Note 10

[0366] An optical wheel according to any one of Notes 1 to 9, characterized in that the substrate has a step portion provided on the outer peripheral side of the second surface, the thickness of the substrate at the step portion is smaller than the thickness of the substrate at a portion other than the step portion, and the balancer is fixed to the step portion by a photocurable adhesive.

[0367] This structure prevents the photocurable adhesive from flowing toward the center of the substrate before curing, which could result in poor curing. This prevents a decrease in the fixing strength of the balancer to the substrate. Furthermore, it prevents the photocurable adhesive from moving toward the center of the substrate, thus preventing the balancer from shifting.

[0368] Note 11

[0369] The optical wheel according to any one of Supplementary Notes 1 to 10, wherein the color changing body is a wavelength converter that converts the wavelength of incident light.

[0370] According to such a configuration, it is possible to configure a fluorescent wheel capable of exhibiting the effects of the above-mentioned optical wheel.

[0371] Note 12

[0372] The optical wheel according to any one of Supplementary Notes 1 to 10, wherein the color changing body is a color filter that emits light of a predetermined wavelength band among incident light.

[0373] With such a configuration, a color wheel capable of exhibiting the effects of the above-mentioned optical wheel can be configured.

[0374] Note 13

[0375] A light conversion device comprising: the optical wheel according to any one of Supplementary Notes 1 to 12; and a motor for rotating the optical wheel.

[0376] This structure achieves the same effects as the aforementioned optical wheel. Furthermore, in addition to reducing the inertial load of the optical wheel, it also reduces the weight of the optical wheel, enabling even a low-torque motor to rotate the optical wheel. Consequently, the optical conversion device can employ a low-torque motor, thereby reducing the cost of the motor employed in the optical conversion device.

[0377] Note 14

[0378] A projector, characterized in that the projector comprises: the light conversion device described in Appendix 13; a light source that emits light incident on the light conversion device; an image generating device that generates image light based on the light emitted from the light conversion device; and a projection optical device that projects the generated image light.

[0379] According to this structure, the same effects as those of the above-mentioned light conversion device can be achieved. In addition, since the optical wheel can be rotated stably, a projector capable of stably projecting image light can be constructed.

Claims

1. An optical wheel, characterized in that: The optical wheel has: a rotatable wheel; and a balancer that rotates with the wheel and corrects the rotational balance of the wheel, The wheel has: a disc-shaped substrate having a first surface and a second surface opposite to the first surface; a color light changing body disposed on the first surface and emitting light having a peak wavelength different from the peak wavelength of the incident light; as well as a plurality of fins arranged on the second surface and extending from a portion on the central side of the substrate toward an outer peripheral edge of the substrate; The balancer is disposed between two fins facing each other among the plurality of fins.

2. The optical wheel according to claim 1, wherein: The balancer is arranged on the outer peripheral edge side of the substrate.

3. The optical wheel according to claim 1, wherein: The balancer is fixed to at least one of the two fins.

4. The optical wheel according to claim 3, wherein: The balancer is fixed to a fin, of the two fins, which is arranged on the upstream side with respect to one fin in the rotation direction of the wheel.

5. The optical wheel according to claim 4, wherein: The intersection angle between the extension direction of the upstream fin to the outer peripheral side and the tangent part is less than 90°, and the tangent part is a tangent part of the substrate at the intersection position of the extension direction of the upstream fin to the outer peripheral side and the outer peripheral edge of the substrate, extending from the intersection position to the side opposite to the rotation direction.

6. The optical wheel according to claim 3, wherein: An intersection angle between an extension direction of the at least one fin toward the outer peripheral edge and a tangent line to the substrate at an intersection position between the extension direction of the at least one fin toward the outer peripheral edge and the outer peripheral edge of the substrate is 90°.

7. The optical wheel according to any one of claims 3 to 6, characterized in that The balancer is fixed by a light-curing adhesive in a state of contact with the at least one fin. The at least one fin includes an enlarged portion in which a fin thickness increases toward the second surface and the enlarged portion contacts the balancer.

8. The optical wheel according to claim 7, wherein: The outer surface of the expanded portion is formed in one of a curved surface and a flat surface.

9. The optical wheel according to any one of claims 1 to 6, characterized in that The balancer is fixed to the second surface.

10. The optical wheel according to any one of claims 1 to 6, characterized in that The substrate has a step portion provided on the outer peripheral edge side of the second surface, The thickness of the substrate at the step portion is smaller than the thickness of the substrate at portions other than the step portion. The balancer is fixed to the step portion with a photocurable adhesive.

11. The optical wheel according to any one of claims 1 to 6, characterized in that The color changer is a wavelength converter that converts the wavelength of incident light.

12. The optical wheel according to any one of claims 1 to 6, characterized in that The color changer is a color filter that emits light of a predetermined wavelength band among incident light.

13. A light conversion device, characterized in that: The light conversion device comprises: The optical wheel according to any one of claims 1 to 6; and A motor rotates the optical wheel.

14. A projector, characterized in that: The projector features: The light conversion device according to claim 13; a light source that emits light incident on the light conversion device; an image generating device for generating image light based on the light emitted from the light conversion device; and A projection optical device projects the generated image light.

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