Optical wheel, light conversion device, and projector

Abstract

To provide an optical wheel, a light conversion device, and a projector capable of reducing weight and size of a wheel.SOLUTION: An optical wheel includes a rotatable wheel, and a balancer that is rotated with the wheel and corrects rotation balance of the wheel, the wheel has a disk-shaped board that has a first surface, and a second surface in a side opposite to the first surface, a color light changing body that is disposed on the first surface and emits light having a peak wavelength different from the peak wavelength of incident light, and multiple fins that are disposed on the second surface and extend toward an outer circumferential edge of the board from a part in a center side of the board. The balancer is disposed between two mutually opposing fins from among multiple fins.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to an optical wheel, an optical conversion device, and a projector.

Background Art

[0002] Conventionally, a phosphor wheel device that is adopted in a projector and emits fluorescence obtained by converting the wavelength of incident blue light is known (see, for example, Patent Document 1). The phosphor wheel device described in Patent Document 1 includes a motor, a phosphor wheel substrate, a first balancer, and a second balancer. The motor has a rotor, and the phosphor wheel substrate is attached to one end side of the rotation axis of the motor. The first balancer is located on one end side of the motor and fixed to the phosphor wheel substrate, and the second balancer is integrally attached to the rotor on the other end side of the rotation axis of the motor. In the phosphor wheel substrate, a phosphor layer concentric with the rotation axis is provided on the surface of one end side of the rotation axis. The first balancer and the second balancer are formed in a flat hollow cylindrical shape.

[0003] Here, if the center of gravity position of the phosphor wheel substrate does not coincide with the rotation axis, not only reliability cannot be ensured, but also a problem occurs in that noise increases. On the other hand, in the phosphor wheel device described in Patent Document 1, the center of gravity position of the phosphor wheel substrate is adjusted by cutting at least one of the first balancer and the second balancer with a cutting machine.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, at a position close to the rotation axis, the variation range of the balance due to the cutting of the balancer is small. For this reason, in the phosphor wheel device described in Patent Document 1, it is necessary to configure the balancer to be large, and the weight of each balancer tends to be large. When each balancer becomes large, there is a problem that the size of the phosphor wheel device on the rotation axis becomes large. Further, when the weight of each balancer becomes large, the influence of the inertia load becomes large, and there is a problem that a motor that generates a large torque is required. For these reasons, a wheel configuration that can achieve weight reduction and size reduction has been demanded.

Means for Solving the Problems

[0006] The optical wheel according to the first aspect of the present disclosure includes a rotatable wheel and a balancer that rotates together with the wheel and corrects the rotational balance of the wheel. The wheel includes a disk-shaped substrate having a first surface and a second surface opposite to the first surface, a color light modifier disposed on the first surface and emitting 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 fins that face each other among the plurality of fins.

[0007] The light conversion device according to the second aspect of the present disclosure includes the optical wheel according to the first aspect and a motor that rotates the optical wheel.

[0008] The projector according to the third aspect of the present disclosure includes the light conversion device according to the second aspect, a light source that emits light incident on the light conversion device, an image generation device that generates image light from the light emitted from the light conversion device, and a projection optical device that projects the generated image light.

Brief Description of the Drawings

[0009]

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Embodiments for Carrying Out the Invention

[0010] [First Embodiment] Hereinafter, the first embodiment of the present disclosure will be described with reference to the drawings. [Schematic Configuration of Projector] FIG. 1 is a schematic diagram showing the configuration of a projector 1 according to the present embodiment. The projector 1 according to the present embodiment projects image light according to image information. As shown in FIG. 1, the projector 1 includes an exterior housing 11 and an image projection device 2 housed in the exterior housing 11. In addition, although not shown, the projector 1 includes a control device that controls the operation of the projector 1, a power supply device that supplies power to the electronic components of the projector 1, and a cooling device that cools the components to be cooled of the projector 1.

[0011] [Configuration of Image Projection Device] The image projection device 2 forms image light according to the input image information and projects the formed image light. The image projection device 2 includes a light source device 3, a homogenizing optical system 21, a color separation optical system 22, a relay optical system 23, an image generation device 24, a housing for optical components 25, and a projection optical device 26.

[0012] The light source device 3 emits illumination light to the homogenizing optical system 21. The configuration of the light source device 3 will be described in detail later. The homogenizing optical system 21 homogenizes the illumination light emitted from the light source device 3. The homogenized illumination light passes through the color separation optical system 22 and the relay optical system 23 and illuminates the modulation region of a light modulation element 243 described later. The homogenizing optical system 21 includes two lens arrays 211, 212, a polarization conversion element 213, and a superposition lens 214. The color separation optical system 22 separates the illumination light incident from the homogenizing optical system 21 into red, green, and blue color lights. The color separation optical system 22 includes two dichroic mirrors 221, 222 and a reflection mirror 223 that reflects the blue light separated by the dichroic mirror 221.

[0013] The relay optical system 23 is provided on the optical path of red light, which is longer than the optical paths of other color lights, to suppress the loss of red light. The relay optical system 23 includes an incident-side lens 231, relay lenses 233, and reflection mirrors 232 and 234. In this embodiment, red light is guided to the relay optical system 23. However, the present invention is not limited to this. For example, a color light whose optical path is longer than that of other color lights may be blue light, and a configuration may be adopted in which blue light is guided to the relay optical system 23.

[0014] The image generation device 24 generates image light from the light emitted from the light source device 3. That is, the image generation device 24 generates image light from the light emitted from the wavelength conversion device 5A of the light source device 3 described later. Specifically, the image generation device 24 modulates the incident red, green, and blue color lights, and synthesizes the modulated color lights to generate image light. The image generation device 24 includes three field lenses 241 provided according to the incident color light, three incident-side polarizing plates 242, three light modulation elements 243, three exit-side polarizing plates 244, and one color synthesis optical system 245.

[0015] The light modulation element 243 modulates the light from the light source device 3 to form image light. Specifically, the light modulation element 243 modulates the color light incident from the incident-side polarizing plate 242 according to the image signal, and emits the modulated color light. The three light modulation elements 243 include a light modulation element 243R that modulates red light, a light modulation element 243G that modulates green light, and a light modulation element 243B that modulates blue light. An example of the light modulation element 243 is a transmissive liquid crystal panel.

[0016] The color synthesis optical system 245 synthesizes the three color lights modulated by the light modulation elements 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 configured by a substantially rectangular cross dichroic prism, but it may be configured by a plurality of dichroic mirrors.

[0017] The housing 25 for optical components houses the above-described homogenizing optical system 21, color separation optical system 22, relay optical system 23, and image generation device 24 therein. Note that a design optical axis Ax1 is set for the image projection device 2, and the housing 25 for optical components holds the homogenizing optical system 21, color separation optical system 22, relay optical system 23, and image generation device 24 at predetermined positions on the optical axis Ax1. The light source device 3 and the projection optical device 26 are arranged at predetermined positions on the optical axis Ax1. The projection optical device 26 projects the image light incident from the image generation device 24 onto a projection surface such as a screen. That is, the projection optical device 26 projects the image light formed by the image generation device 24. The projection optical device 26 can be, for example, a combination lens including a plurality of lenses (not shown) and a lens barrel 261 that houses the plurality of lenses.

[0018] [Configuration of Light Source Device] FIG. 2 is a schematic diagram showing the configuration of the light source device 3. The light source device 3 emits illumination light for illuminating the image generation device 24 to the homogenizing optical system 21. As shown in FIG. 2, the light source device 3 includes a light source housing 31, a light source 32, an afocal optical element 33, a first phase difference element 34, a diffusing transmission element 35, a light separation / combination element 36, a first condenser element 37, a second phase difference element 38, a second condenser element 39, a diffusing optical element 40, a third phase difference element 41, and a wavelength conversion device 5A.

[0019] In the light source device 3, an optical axis Ax2 extending linearly and an optical axis Ax3 that is orthogonal to the optical axis Ax2 and extends linearly are set. The optical axis Ax3 overlaps with the optical axis Ax1 in the homogenizing optical system 21. The light source 32, afocal optical element 33, first phase difference element 34, diffusing transmission element 35, light separation / combination element 36, second phase difference element 38, second condenser element 39, and diffusing optical element 40 are arranged on the optical axis Ax2. The wavelength conversion device 5A, first condenser element 37, light separation / combination element 36, and third phase difference element 41 are arranged on the optical axis Ax3. In the following description, three mutually perpendicular directions are defined as the +X direction, the +Y direction, and the +Z direction. In this embodiment, the +X direction is the direction in which the light source 32 emits light along the optical axis Ax2, and the +Z direction is the direction in which the light source device 3 emits illumination light along the optical axis Ax3. Although not shown, the direction opposite to the +X direction is defined as the -X direction, the direction opposite to the +Y direction is defined as the -Y direction, and the direction opposite to the +Z direction is defined as the -Z direction.

[0020] [Configuration of the Light Source Housing] The light source housing 31 houses the light source 32, the afocal optical element 33, the first phase difference element 34, the diffusion transmission element 35, the optical separation / combination element 36, the first condenser element 37, the second phase difference element 38, the second condenser element 39, the diffusion optical element 40, the third phase difference element 41, and the wavelength conversion device 5A. The light source housing 31 is a sealed housing that makes it difficult for dust and the like to enter the interior.

[0021] [Configuration of the Light Source] The light source 32 includes at least one solid-state light-emitting element 321, and at least one solid-state light-emitting element 321 emits light in the +X direction to the diffusion optical element 40 and the wavelength conversion device 5A. The solid-state light-emitting element 321 emits blue light as excitation light. For example, the solid-state light-emitting element 321 is an LD (Laser Diode) that emits laser light with a peak wavelength of 440 nm. The light emitted by the light source 32 is s-polarized blue light BLs with respect to the optical separation / combination element 36. However, it is not limited to this, and the light emitted by the light source 32 may be p-polarized blue light BLp with respect to the optical separation / combination element 36, or may be blue light in which s-polarization and p-polarization are mixed. In the latter case, the first phase difference element 34 can be omitted.

[0022] [Configuration of the Afocal Optical Element] The afocal optical element 33 adjusts the beam diameter of the blue light BLs incident from the light source 32 in the +X direction. The afocal optical element 33 is composed of a lens 331 that condenses the incident light and a lens 332 that collimates the light beam condensed by the lens 331. Note that the afocal optical element 33 may be omitted.

[0023] [Configuration of the first retardation element] The first retardation element 34 is provided between the lens 331 and the lens 332. The first retardation element 34 converts a part of the incident blue light BLs into blue light BLp and emits light containing s-polarized blue light BLs and p-polarized blue light BLp. The first retardation element 34 may be rotated about an axis along the optical axis Ax2 by a rotating device. In this case, according to the rotation angle of the first retardation element 34, the ratio of the s-polarized component to the p-polarized component in the blue light emitted from the first retardation element 34 can be adjusted.

[0024] [Configuration of the diffusing transmission element] The diffusing transmission element 35 equalizes the illuminance distribution of the blue light BLp and BLs incident from the lens 332 in the +X direction. The blue light BLs and BLp that have passed through the diffusing transmission element 35 are incident on the optical separation and synthesis element 36. Examples of the configuration of the diffusing transmission element 35 include a configuration having a hologram, a configuration in which a plurality of small lenses are arranged on a plane orthogonal to the optical axis, and a configuration in which the surface through which light passes is a rough surface. Note that instead of the diffusing transmission element 35, a homogenizer optical element having a pair of multi-lenses may be employed.

[0025] [Configuration of the optical separation and synthesis element] The optical separation and synthesis element 36 has a function as an optical separation element that separates incident light and a function as an optical synthesis element that synthesizes light incident from two directions. The optical separation and synthesis element 36 is a polarizing beam splitter that separates the s-polarized component and the p-polarized component contained in the incident light. Specifically, the optical separation and synthesis element 36 reflects the s-polarized component and transmits the p-polarized component. Also, the optical separation and synthesis element 36 has a color separation characteristic of transmitting light having a predetermined wavelength or longer regardless of whether it is an s-polarized component or a p-polarized component. Therefore, among the blue light BLp and BLs incident from the diffusing transmission element 35 to the optical separation and synthesis element 36, the p-polarized blue light BLp passes through the optical separation and synthesis element 36 in the +X direction and is incident on the second retardation element 38. On the other hand, the s-polarized blue light BLs is reflected in the -Z direction by the optical separation and synthesis element 36 and is incident on the first condenser lens 37. Note that the optical separation and combination element 36 may have the function of a half mirror that allows part of the light incident from the light source 32 through the diffusion transmission element 35 to pass through and reflects the remaining light, and the function of a dichroic mirror that reflects the blue light incident from the diffusion optical element 40, transmits the fluorescence incident from the wavelength conversion device 5A and having a wavelength longer than that of the blue light. In this case, the first retardation element 34 can be omitted.

[0026] [Configuration of the First Condensing Element] The first condensing element 37 constitutes a pickup optical system. The first condensing element 37 condenses the blue light BLs reflected in the -Z direction by the optical separation and combination element 36 onto a wavelength converter 54 of a phosphor wheel 51A included in the wavelength conversion device 5A. Further, the first condensing element 37 collimates the fluorescence YL incident from the wavelength converter 54 in the +Z direction and emits the collimated fluorescence YL to the optical separation and combination element 36. In the present embodiment, the first condensing element 37 is composed of three lenses 371, 372, and 373, but the number of lenses constituting the first condensing element 37 is not limited.

[0027] [Schematic Configuration of the Wavelength Conversion Device] The wavelength conversion device 5A includes a phosphor wheel 51A that converts the wavelength of the blue light BLs incident from the first condensing element 37 and emits fluorescence YL. The phosphor wheel 51A is a so-called reflective wavelength conversion element and emits fluorescence YL in a direction opposite to the incident direction of the blue light BLs, which is the excitation light. Note that the configuration of the wavelength conversion device 5A will be described in detail later.

[0028] The fluorescence YL emitted from the wavelength conversion device 5A in the +Z direction is collimated by the first condensing element 37 and then enters the optical separation and combination element 36. As described above, since the optical separation and combination element 36 has the property of transmitting the fluorescence YL, the fluorescence YL incident on the optical separation and combination element 36 along the +Z direction passes through the optical separation and combination element 36 and enters the third retardation element 41.

[0029] [Configuration of the Second Retardation Element] The second retardation element 38 is arranged in the +X direction with respect to the optical separation and combination element 36. That is, the second retardation element 38 is arranged between the optical separation and combination element 36 and the second condenser lens 39. The second retardation element 38 converts the blue light BLp that has passed through the optical separation and combination element 36 in the +X direction into circularly polarized blue light BLc. The blue light BLc that has passed through the second retardation element 38 in the +X direction is incident on the second condenser lens 39.

[0030] [Configuration of the second condenser lens] The second condenser lens 39 condenses the blue light BLc that has passed through the optical separation and combination element 36 in the +X direction and is incident from the second retardation element 38 onto the diffusing optical element 40. Also, the second condenser lens 39 collimates the light incident from the diffusing optical element 40 in the -X direction and emits it to the second retardation element 38. In this embodiment, the second condenser lens 39 is composed of three lenses 391, 392, and 393, but the number of lenses constituting the second condenser lens 39 is not limited.

[0031] [Configuration of the diffusing optical element] The diffusing optical element 40 diffuses the incident blue light BLc at the same diffusion angle as the fluorescence YL emitted from the wavelength conversion device 5A. Specifically, the diffusing optical element 40 reflects and diffuses the blue light BLc incident from the second condenser lens 39 in the +X direction in the -X direction. The diffusing optical element 40 is a reflecting element that Lambert reflects the incident blue light BLc. Note that the diffusing optical element 40 may be rotated about a rotation axis parallel to the optical axis Ax2 by a rotating device. The blue light BLc diffused by the diffusing optical element 40 is incident on the second retardation element 38 after passing through the second condenser lens 39. When the blue light BLc incident on the diffusing optical element 40 is reflected by the diffusing optical element 40, it is converted into circularly polarized light with the opposite rotation direction. For this reason, the blue light BLc incident on the second retardation element 38 via the second condenser lens 39 is converted into s-polarized blue light BLs by the second retardation element 38. Then, the blue light BLs is reflected in the +Z direction by the optical separation and combination element 36 and is incident on the third retardation element 41. That is, the light incident on the third retardation element 41 from the optical separation and combination element 36 is white light in which the blue light BLs and the fluorescence YL are mixed.

[0032] [Configuration of the third phase difference element] The third phase difference element 41 converts the white light including the blue light BLs and the fluorescence YL incident from the optical separation and combination element 36 into white light in which s-polarized light and p-polarized light are mixed. The white light thus converted is emitted in the +Z direction as illumination light LT and is incident on the above-described homogenizing optical system 21.

[0033] [Configuration of the wavelength conversion device] FIGS. 3 and 4 are perspective views showing the wavelength conversion device 5A. More specifically, FIG. 3 is a perspective view showing the wavelength conversion device 5A as viewed from the incident side of the blue light BLs, and FIG. 4 is a perspective view showing the wavelength conversion device 5A as viewed from the side opposite to the incident side of the blue light BLs. FIGS. 5 and 6 are exploded perspective views showing the wavelength conversion device 5A. More specifically, FIG. 5 is an exploded perspective view showing the wavelength conversion device 5A as viewed from the incident side of the blue light BLs, and FIG. 4 is an exploded perspective view showing the wavelength conversion device 5A as viewed from the side opposite to the incident side of the blue light BLs. The wavelength conversion device 5A is an optical conversion device that emits colored light having a peak wavelength different from the peak wavelength of the incident light. In other words, the wavelength conversion device 5A emits converted light obtained by converting the wavelength of the incident excitation light. Specifically, the wavelength conversion device 5A emits fluorescence YL, which is converted light having a wavelength range longer than the wavelength range of the incident excitation light, i.e., blue light BLs. As shown in FIGS. 3 to 6, the wavelength conversion device 5A includes a phosphor wheel 51A and a motor 58. The phosphor wheel 51A and the motor 58 are combined to form a suction portion that sucks the cooling gas into the wavelength conversion device 5A.

[0034] [Configuration of the motor] First, the motor 58 will be described. The motor 58 rotates the phosphor wheel 51A about the rotation axis Rx. The motor 58 includes a motor body 581, a support substrate 582, and a rotor 583. Although detailed illustration of the motor body 581 is omitted, it has a rotor and a stator that rotates the rotor. The support substrate 582 supports the motor body 581. As shown in FIGS. 4 and 6, the support substrate 582 has a control circuit 5821, and the control circuit 5821 is connected to the above-described control device via the flexible printed circuit board FP. The control circuit 5821 drives the motor body 581 according to an electrical signal input via the flexible printed circuit board FP.

[0035] The rotating body 583 is fixed to the rotor of the motor body 581 and rotates integrally with the rotor. The rotating body 583 is connected to the phosphor wheel 51A and is rotated together with the phosphor wheel 51A by the motor body 581. The rotating body 583 is disposed on the phosphor wheel 51A side with respect to the motor body 581. As shown in FIG. 5, the rotating body 583 has a columnar portion 5831 and a flange portion 5832.

[0036] The columnar portion 5831 is a portion that protrudes in the +Z direction in a columnar shape around the rotation axis Rx. The flange portion 5832 is a portion disposed outside the columnar portion 5831 and is formed in a disk shape centered on the rotation axis Rx. The flange portion 5832 engages with the protrusion 534 of the wheel 52A of the phosphor wheel 51A. Specifically, the flange portion 5832 contacts the end portion in the -Z direction of the protrusion 534. 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 insertion holes 5833 penetrating the flange portion 5832 along the rotation axis Rx are provided at the peripheral edge of the flange portion 5832. The plurality of insertion holes 5833 are provided at equal intervals in the circumferential direction centered on the rotation axis Rx. More specifically, each of the plurality of insertion holes 5833 is provided at a position corresponding to the protrusion 534 in the flange portion 5832. A screw SC for connecting the rotating body 583 to the phosphor wheel 51A is inserted into each insertion hole 5833 in the +Z direction. Then, the rotating body 583 and the phosphor wheel 51A are connected by fixing the screw SC inserted through the insertion hole 5833 to the protrusion 534.

[0037] [Configuration of the phosphor wheel] The phosphor wheel 51A corresponds to an optical wheel and is rotated by a motor 58. The phosphor wheel 51A includes a wheel 52A and a balancer 57A. The wheel 52A is rotatable by the motor 58. The wheel 52A includes a substrate 53, a wavelength converter 54, a reflection part 55, and a plurality of fins 56.

[0038] [Configuration of the substrate] The substrate 53 is configured in a disk shape. It supports the wavelength converter 54, the reflection part 55, and the plurality of fins 56. The substrate 53 is rotated about a rotation axis Rx by a motor 58 having a rotor 583 connected to the substrate 53. The substrate 53 is configured in a ring shape centered on the rotation axis Rx and is formed of, for example, metal. The substrate 53 has a first surface 531, a second surface 532, and an opening 533. The first surface 531 is a surface facing the +Z direction. The wavelength converter 54 and the reflection part 55 are arranged on the first surface 531. The second surface 532 is a surface on the opposite side of the first surface 531 and faces the -Z direction. The plurality of fins 56 are arranged on the second surface 532. The opening 533 penetrates the substrate 53 from the first surface 531 to the second surface 532 along the rotation axis Rx. The opening 533 is formed in a circular shape when viewed from the +Z direction, which is the incident side of the excitation light. Although it will be described in detail later, when the substrate 53 rotates, an air flow circulates into the opening 533 from the space in the +Z direction with respect to the substrate 53.

[0039] [Configuration of the plurality of protrusions] As shown in FIGS. 4 and 6, the substrate 53 further has a plurality of protrusions 534. The plurality of protrusions 534 are provided at equal intervals in the circumferential direction centered on the rotation axis Rx at positions near the inner peripheral edge of the opening 533 outside the opening 533 on the second surface 532. That is, each of the plurality of protrusions 534 protrudes in the -Z direction from the second surface 532 toward the rotating body 583. Each of the plurality of protrusions 534 has a threaded hole into which the screw SC is inserted along the +Z direction. The screw SC inserted through the insertion hole 5833 of the rotating body 583 in the +Z direction is fixed to the threaded hole of each protrusion 534, thereby connecting the substrate 53 of the phosphor wheel 51A and the rotating body 583.

[0040] [Configuration of Wavelength Converter and Reflection Part] The wavelength converter 54 is a color light changer 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 fluorescence YL having a peak wavelength longer than the peak wavelength of the incident blue light BLs. That is, the wavelength converter 54 emits fluorescence YL, which is light in a wavelength band different from the wavelength band of the incident blue light BLs, which is the excitation light. The wavelength converter 54 contains a phosphor that is excited by the incidence of the excitation light and emits fluorescence YL, which is converted light having a wavelength longer than the wavelength of the excitation light. As shown in FIGS. 3 and 5, the wavelength converter 54 is formed in a ring shape centered on the rotation axis Rx when viewed from the +Z direction and is fixed outside the opening 533 on the first surface 531 of the substrate 53. The reflection part 55 is disposed between the first surface 531 of the substrate 53 and the wavelength converter 54. The reflection part 55 reflects the light incident from the wavelength converter 54 to the wavelength converter 54 side. The reflection part 55 can be configured as a reflection layer provided on the first surface 531 or the wavelength converter 54. In this case, the reflection part 55 may be a reflection layer provided on substantially the entire surface of the first surface 531. In addition, when the first surface 531 has sufficiently high light reflectivity, the first surface 531 can be adopted as the reflection part 55.

[0041] [Configuration of Multiple Fins] The plurality of fins 56 rotate together with the substrate 53 to generate an air flow that dissipates the heat transmitted 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 side. Specifically, the plurality of fins 56 are integrally provided on the second surface 532. As shown in FIG. 5, each of the plurality of fins 56 extends from the portion on the rotation axis Rx side of the substrate 53 toward the outer peripheral edge side of the substrate 53. That is, each of the plurality of fins 56 extends from the portion on the center side of the substrate 53 toward the outer peripheral edge side of the substrate 53. The plurality of fins 56 are arranged side by side around the opening 533. More specifically, the plurality of fins 56 are arranged at equal intervals in the circumferential direction centered on the rotation axis Rx around the opening 533. When the phosphor wheel 51A rotates by the motor 58, the plurality of fins 56 rotate integrally with the substrate 53.

[0042] Each of the plurality of fins 56 has a first end portion 561, a second end portion 562, and a connecting portion 563. The first end portion 561 is the end portion on the rotation axis Rx side of the fin 56. The first end portion 561 is disposed outside the opening 533 and in the vicinity of the inner peripheral edge of the opening 533. The second end portion 562 is the end portion on the outer peripheral edge side of the substrate 53 of the fin 56, and is disposed on the outer peripheral edge of the second surface 532 of the substrate 53. Note that the second end portion 562 may be located slightly on the rotation axis Rx side from the outer peripheral edge of the substrate 53.

[0043] FIG. 7 is a view of the wavelength conversion device 5A as seen from the side opposite to the incident side of the excitation light. That is, FIG. 7 is a plan view showing the wavelength conversion device 5A as seen from the -Z direction. As shown in FIG. 7, each fin 56 extends in a curved shape such that, when viewed from the -Z direction, it is positioned in a direction opposite to the rotation direction RD of the substrate 53 as it extends from the first end portion 561 toward the outer peripheral edge side of the substrate 53. That is, each fin 56 is formed in an arc shape when viewed from the -Z direction. However, not limited to this, each fin 56 may extend in a curved shape such that, when viewed from the -Z direction, it is positioned in the rotation direction RD as it extends from the first end portion 561 toward the outer peripheral edge of the substrate 53. Alternatively, each fin 56 may extend linearly when viewed from the -Z direction. In this case, each fin 56 may extend radially about the rotation axis Rx, and may extend linearly such that it is positioned in the rotation direction RD, or in a direction opposite to the rotation direction RD, as it extends from the first end portion 561 toward the outer peripheral edge side of the substrate 53. Note that each fin 56 may be disposed at a position where the extension line on the rotation axis Rx side does not intersect the rotation axis Rx. That is, the extension line of each fin 56 extending toward the rotation axis Rx side may not intersect the rotation axis Rx. Also, the number of fins 56 can be appropriately changed as long as it is 2 or more.

[0044] The connecting portion 563 is a stepped portion provided in a portion of the fin 56 on the rotation axis Rx side including the first end portion 561. The connecting portion 563 is a portion where the protruding dimension in the -Z direction from the second surface 532 of the fin 56 is smaller than the protruding dimensions of other portions. The connecting portion 563 is such that when the phosphor wheel 51A and the motor 58 are connected, the +Z direction surface of the flange portion 5832 of the rotating body 583 can come into contact. Note that the connecting portion 563 does not necessarily have to be a stepped portion. That is, the surface of each fin 56 facing the rotating body 583 may function as the connecting portion 563 and come into contact with the flange portion 5832 of the rotating body 583. On the other hand, each of the plurality of fins 56 does not necessarily have to come into contact with the rotating body 583. Between such a plurality of fins 56, a flow path is formed through which gas flowing into the opening 533 from the +Z direction space with respect to the phosphor wheel 51A can flow when the phosphor wheel 51A rotates. That is, between two adjacent fins 56 among the plurality of fins 56, a flow path through which gas flows from the rotation axis Rx side toward the outer peripheral edge side of the substrate 53 is formed.

[0045] [Configuration of the Balancer] The balancer 57A rotates together with the wheel 52A and corrects the rotational balance of the wheel 52A. The balancer 57A is provided on the second surface 532 of the substrate 53 as shown in FIGS. 4, 6, and 7. More specifically, the balancer 57A is disposed in contact with the second surface 532 between two adjacent fins 56A and 56B among the plurality of fins 56. More specifically, the balancer 57A is disposed substantially at the center of the two fins 56A and 56B in the circumferential direction centered on the rotation axis Rx. Specifically, the balancer 57A is fixed to a portion on the outer peripheral edge side of the substrate 53 on the second surface 532. For example, the balancer 57A is disposed outside a concentric circle having 80% of the diameter of the substrate 53 among concentric circles having the same center as the substrate 53.

[0046] Such a balancer 57A can be exemplified by a metal body such as a copper plate fixed by an adhesive or the like, a laminate of balancer constituent members having the same weight, and a laminate of balancer constituent members having different weights from each other. Alternatively, the balancer 57A can be constituted by an adhesive. Examples of such an adhesive include photocurable adhesives such as ultraviolet curable adhesives, resin-based adhesives such as acrylic adhesives and epoxy adhesives, resin-based adhesives containing metals, brazing materials such as silver solder, and soldering materials. In addition, the balancer 57A may be a combination of the substances exemplified above.

[0047] [Effects of the First Embodiment] The projector 1 according to the present embodiment described above has the following effects. The projector 1 includes a light source 32, a wavelength conversion device 5A, an image generation device 24, and a projection optical device 26. The light source 32 emits light that is incident on the wavelength conversion device 5A. The image generation device 24 generates image light from the light emitted from the wavelength conversion device 5A. The projection optical device 26 projects the generated image light.

[0048] The wavelength conversion device 5A is a light conversion device that emits fluorescence YL with the wavelength of incident blue light converted. The wavelength conversion device 5A includes a phosphor wheel 51A as an optical wheel and a motor 58 that rotates the phosphor wheel 51A. The phosphor wheel 51A includes a rotatable wheel 52A and a balancer 57A that rotates with the wheel 52A and corrects the rotational balance of the wheel 52A. The wheel 52A includes a disk-shaped substrate 53, a wavelength converter 54, and a plurality of fins 56. The substrate 53 has a first surface 531 and a second surface 532 on the side opposite to the first surface 531. The wavelength converter 54 corresponds to a color light 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 the present embodiment, the wavelength converter 54 emits fluorescence YL having a peak wavelength different from the peak wavelength of the incident blue light BLs. The plurality of fins 56 are disposed on the second surface 532 and extend from the center side of the substrate 53 toward the outer peripheral edge of the substrate 53. The balancer 57A is disposed between two fins 56A and 56B that face each other among the plurality of fins 56.

[0049] According to such a configuration, since the balancer 57A is provided on the substrate 53, the rotational balance of the wheel 52A can be corrected. Therefore, the inertia load of the wheel 52A can be reduced. Further, the balancer 57A is disposed between two fins 56A and 56B that face each other among the plurality of fins 56 disposed on the second surface 532. Therefore, the area where the balancer 57A can be disposed on the substrate 53 can be expanded, so that the balancer 57A can be disposed at a position away from the rotation axis Rx of the substrate 53. Thereby, even if the weight of the balancer 57A is small, the rotational balance of the substrate 53 can be corrected and the influence of the inertia load can be reduced. In addition, it is not necessary to provide an outer peripheral edge portion such as a flange for disposing the balancer 57A on the substrate 53. Therefore, the substrate 53 can be lightened, and thus the phosphor wheel 51A can be lightened, and the phosphor wheel 51A can be miniaturized. Further, when the diameter of the substrate provided with the outer peripheral edge portion where the fins 56 are not disposed is the same as the diameter of the substrate 53 on which the balancer 57A is disposed between the two fins 56A and 56B, in the latter substrate 53 according to the present embodiment, the size of the fins 56 extending toward the outer peripheral edge of the substrate 53 can be increased. Thereby, the cooling efficiency of the substrate 53 provided with the wavelength converter 54 can be enhanced.

[0050] In addition, since the inertia load of the phosphor wheel 51A can be reduced and the phosphor wheel 51A can be lightened, a low-torque motor can be adopted as the motor 58. Therefore, the cost of the motor 58 employed in the wavelength conversion device 5A as the light conversion device can be reduced. Further, since the phosphor wheel 51A can be rotated stably, the projector 1 capable of stably projecting the image light can be configured.

[0051] In the phosphor wheel 51A, the balancer 57A is disposed at a portion on the outer peripheral edge side of the substrate 53. According to such a configuration, since the balancer 57A is provided at a portion on the outer peripheral edge side of the substrate 53, the weight of the balancer 57A, and thus the weight of the phosphor wheel 51A, can be reduced as compared with the case where the balancer 57A is disposed on the center side of the substrate 53.

[0052] In the phosphor wheel 51A, the balancer 57A is fixed to the second surface 532. According to such a configuration, the balancer 57A disposed between the two fins 56A and 56B can be stably disposed on the substrate 53.

[0053] In the phosphor wheel 51A, the color light converter is the wavelength converter 54 that converts the wavelength of the incident light. According to such a configuration, the phosphor wheel 51A capable of achieving the above-described effects can be configured.

[0054] [Second Embodiment] Next, a second embodiment of the present disclosure will be described. The projector according to the present embodiment has the same configuration as the projector 1 according to the first embodiment, but the fixed position of the balancer between the two fins is different. In the following description, the same reference numerals are given to the parts that are the same as or substantially the same as the parts already described, and the description thereof is omitted.

[0055] [Schematic Configuration of Projector and Light Source Device] FIG. 8 is a plan view of the wavelength conversion device 5B according to the present embodiment as viewed from the +Z direction. In other words, FIG. 8 is a plan view showing the wavelength conversion device 5B as viewed from the side opposite to the incident side of the blue light BLs which is the excitation light. The projector according to the present embodiment has the same configuration and function as the projector 1 according to the first embodiment, except that the wavelength conversion device 5B shown in FIG. 8 is provided instead of the wavelength conversion device 5A. That is, the light source device according to the present embodiment has the same configuration and function as the light source device 3 according to the first embodiment, except that the wavelength conversion device 5B is provided instead of the wavelength conversion device 5A.

[0056] [Configuration of Wavelength Conversion Device] The wavelength conversion device 5B has the same configuration and functions as the wavelength conversion device 5A according to the first embodiment, except for the arrangement mode of the balancer. Specifically, the wavelength conversion device 5B according to this embodiment has the same configuration and functions as the wavelength conversion device 5A, except that it includes a phosphor wheel 51B instead of the phosphor wheel 51A. That is, the wavelength conversion device 5B includes a phosphor wheel 51B and a motor 58. The wavelength conversion device 5B corresponds to an optical conversion device.

[0057] [Configuration of the phosphor wheel] The phosphor wheel 51B corresponds to an optical wheel and has the same functions as the phosphor wheel 51A. The phosphor wheel 51B includes a wheel 52A and a balancer 57B. The wheel 52A includes a substrate 53, a wavelength converter 54, a reflection part 55, and a plurality of fins 56 as shown in the first embodiment. The balancer 57B is made of the same material as the balancer 57A according to the first embodiment and is configured in the same manner as the balancer 57A.

[0058] The balancer 57A according to the first embodiment was provided between two fins 56A and 56B adjacent to each other on the second surface 532. Specifically, the balancer 57A was fixed to the second surface 532 between the two fins 56A and 56B and spaced apart from each of the fins 56A and 56B. In contrast, the balancer 57B is in contact with at least one of two adjacent fins 56A and 56B. In this embodiment, the balancer 57B is fixed in contact with each of the two fins 56A and 56B. That is, the balancer 57B is fixed in contact with 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, respectively, and is also fixed in contact with the second surface 532. Note that the upstream fin 56A is the fin located in the rotation direction RD among the two fins 56A and 56B. The downstream fin 56B is the fin located in the direction opposite to the rotation direction RD among the two fins 56A and 56B.

[0059] [Shearing force acting on the balancer] FIG. 9 is a diagram for explaining the direction of the shearing force acting on the sample SM fixed to the rotating substrate 53. The arrows in FIG. 9 indicate the acting direction of the force, not the magnitude of the force. Here, the shearing force acting on the sample SM fixed to the second surface 532 of the substrate 53 will be described. While the substrate 53 is rotating, shearing forces in various directions act on the sample SM. Specifically, at the start of rotation of the substrate 53, shearing forces corresponding to the inertial force F1 and the centrifugal force F3 associated with the change in the rotation speed of the substrate 53 act on the sample SM. That is, while the rotation speed of the wheel 52A is increasing, shearing forces corresponding to the inertial force F1 in the rotation direction RD of the substrate 53 and the centrifugal force F3 toward the outer side in the radial direction of the substrate 53 act on the sample SM. When the substrate 53 is rotating at a constant speed, only the shearing force corresponding to the centrifugal force F3 acts on the sample SM. At the time of deceleration of the rotation of the substrate 53, shearing forces corresponding to the inertial force F2 and the centrifugal force F3 associated with the change in the rotation speed of the substrate 53 act on the sample SM. That is, while the rotation speed of the substrate 53 is decreasing, shearing forces corresponding to the inertial force F2 in the direction opposite to the rotation direction RD of the substrate 53 and the centrifugal force F3 act on the sample SM. Such shearing forces also act on the balancer fixed to the substrate 53.

[0060] From these facts, the balancer 57B is in contact with and fixed to each of the upstream fin 56A and the downstream fin 56B. Thereby, even when the inertial force F1 in the rotation direction RD acts on the balancer 57B at the start of rotation of the substrate 53, the balancer 57B can be supported by the upstream fin 56A. Even when the inertial force F2 in the direction opposite to the rotation direction RD acts on the balancer 57B at the time of deceleration of the rotation of the substrate 53, the balancer 57B can be supported by the downstream fin 56B.

[0061] [Intersection angle between the extending direction of the fin and the tangent line] FIG. 10 is a diagram showing the extension direction D1 of the outer peripheral edge side of the upstream fin 56A, and the intersection angle α between the extension direction D1 of the fin 56A and the tangent line L1 of the substrate 53 at the intersection position of the extension direction D1 of the fin 56A and the outer peripheral edge of the substrate 53. As described above, when the wheel 52A starts to rotate, the inertial force F1 acts on the balancer 57B. On the other hand, as shown in FIG. 10, the extension direction of the outer peripheral edge side of the upstream fin 56A with which the balancer 57B contacts is defined as the extension direction D1, and when the tangent line portion extending from the intersection position to the side opposite to the rotation direction RD at the tangent line of the substrate 53 at the intersection position of the extension direction D1 and the outer peripheral edge of the substrate 53 is defined as the tangent line L1, the intersection angle α between the extension direction D1 and the tangent line L1 is preferably 90° or less. That is, with the intersection position as the center, the intersection angle α from the extension direction D1 to the tangent line L1 in the direction opposite to the rotation direction RD is preferably 90° or less. Note that the extension direction D1 is the extension direction of the fin 56A toward the outer peripheral edge side of the substrate 53.

[0062] When the intersection angle α exceeds 90°, the surface of the upstream fin 56A in the direction opposite to the rotation direction RD, that is, the surface with which the balancer 57B contacts, faces the outside of the substrate 53. In such a case, it becomes difficult for the fin 56A to receive the balancer 57B on which the inertial force F1 acts. On the other hand, when the intersection angle α is 90° or less, the balancer 57B on which the inertial force F1 acts can be easily received by the upstream fin 56A. In particular, when the intersection angle α is less than 90°, it becomes easier to discharge the gas flowing between the fins 56 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 as compared with the case where the intersection angle α is 90° or more. Therefore, when the upstream fin 56A and the balancer 57B are in contact, the intersection angle α is preferably 90° or less, and more preferably less than 90°.

[0063] FIG. 11 is a diagram showing the extension direction D2 of the downstream fin 56B toward the outer peripheral edge side, and the intersection angle β between the extension direction D2 of the fin 56B and the tangent line L2 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. As described above, when the rotation of the wheel 52A is decelerated, an inertial force F2 in the direction opposite to the rotation direction RD of the wheel 52A acts on the balancer 57B. On the other hand, as shown in FIG. 11, when the extension direction of the downstream fin 56B in contact with the balancer 57B toward the outer peripheral edge side is defined as the extension direction D2, and the tangent line 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 defined as the tangent line L2, the intersection angle β between the extension direction D2 and the tangent line L2 is preferably 90°. The extension direction D2 is the extension direction of the fin 56B toward the outer peripheral edge side of the substrate 53.

[0064] When the intersection angle β is less than 90°, the surface in the rotation direction RD of the downstream fin 56B, that is, the surface in contact with the balancer 57B, faces the outside of the substrate 53. In such a case, it becomes difficult for the fin 56B to receive the balancer 57B on which the inertial force F2 acts. When the intersection angle β exceeds 90°, the balancer 57B on which the inertial force F2 acts can be easily received by the downstream fin 56B. However, the fin 56B becomes the upstream fin with respect to the fin 56 on the downstream side of the fin 56B. And when the intersection angle β exceeds 90°, the fin 56 extends so as to be positioned in the rotation direction RD from the central part of the substrate 53 toward the outer peripheral edge side. Therefore, when the intersection angle β related to all the fins 56 exceeds 90°, that is, when the extension direction D2 of each fin 56 inclines 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 deteriorates. On the other hand, when the crossing angle β is 90°, the balancer 57B on which the inertial force F2 acts can be easily received by the downstream fin 56B. In addition, since the gas flowing between the fins 56 during the rotation of the wheel 52A can be easily discharged, the cooling performance of the substrate 53 and the wavelength converter 54 can be maintained high. From these facts, when the downstream fin 56B and the balancer 57B are in contact with each other, the crossing angle β is preferably 90°.

[0065] From the above, when the balancer 57B comes into contact with the upstream fin 56A positioned in the rotational direction RD with respect to the balancer 57B, the crossing angle α related to the upstream fin 56A is preferably 90° or less. Further, when the balancer 57B comes into contact with the downstream fin 56B positioned in the direction opposite to the rotational direction RD with respect to the balancer 57B, the crossing angle β related to the downstream fin 56B is preferably 90°. In the wavelength conversion device 5B according to the present embodiment, since the balancer 57B is in contact with each of the upstream fin 56A and the downstream fin 56B, the crossing angles α and β related to each fin 56 are preferably 90°. That is, in the present embodiment, the crossing angle between the extending direction of the fin 56 and the tangent line of the wheel 52A at the crossing position between the extending direction of the fin 56 and the outer peripheral edge of the wheel 52A is preferably 90°.

[0066] When the light source device is turned on, for example, when the power of the projector is turned on, the rotational speed of the wheel 52A rapidly increases. This is because it is necessary to rotate the wheel 52A to move the irradiation spot of the excitation light on the wavelength converter 54 in order to suppress the local temperature rise of the wavelength converter 54 due to the incidence of the excitation light. Therefore, a large shearing force acts on the balancer at the start of rotation of the wheel 52A. On the other hand, when the light source device is turned off, such as when the power of the projector is turned off, the rotational speed of the wheel 52A gradually decreases. This is because as long as the light source 32 is turned off, excitation light does not enter the wavelength converter 54, and the temperature rise of the wavelength converter 54 can be suppressed. Therefore, there is no need to rapidly decrease the rotational speed of the wheel 52A by a brake. Accordingly, the shearing force acting on the balancer when the wheel 52A decelerates is smaller than the shearing force acting on the balancer when the wheel 52A starts rotating. From these facts, it is preferable that each of the plurality of fins 56 is arranged so that the crossing angle related to the fin 56 is 90° or less, giving priority to suppressing the peeling of the balancer 57B by the upstream fin 56A.

[0067] [Effects of the Second Embodiment] The projector according to the present embodiment described above has the same effects as the projector 1 according to the first embodiment, and also has the following effects. In the phosphor wheel 51B as an optical wheel, the balancer 57B is fixed to at least one of the two fins 56A and 56B sandwiching the balancer 57B. More specifically, the balancer 57B is fixed in contact with each of the two fins 56A and 56B.

[0068] As described above, a large force is applied in the tangential direction of the substrate 53 when the phosphor wheel 51B starts rotating and decelerates. Therefore, in order to suppress the peeling of the balancer from the substrate 53, it is necessary to firmly fix the balancer to the substrate. On the other hand, since the balancer 57B is fixed to each of the upstream fin 56A and the downstream fin 56B, even if a large shearing force acts on the balancer 57B at the time of starting rotation and decelerating rotation of the phosphor wheel 51B, the balancer 57B on which the shearing force acts can be received by the fins 56A and 56B. Therefore, the dropout of the balancer 57B from the substrate 53 can be suppressed.

[0069] In the phosphor wheel 51B, the balancer 57B is fixed to the upstream fin 56A that is arranged in the rotational direction RD of the wheel 52A with respect to the downstream fin 56B among the two fins 56A and 56B. As described above, the tangential force acting on the balancer at the start of rotation is greater than the tangential force acting on the balancer at the time of rotational deceleration. For this reason, since the balancer 57B is fixed to the upstream fin 56A located in the rotational direction RD of the wheel 52A, the upstream fin 56A can receive the balancer 57B on which the shearing force acts. Therefore, the dropout of the balancer 57B from the substrate 53 can be effectively suppressed. Note that since the balancer 57B is in contact with and fixed to not only the upstream fin 56A but also the downstream fin 56B, the fin 56B can receive the balancer 57B on which the shearing force acts when the rotation of the wheel 52A decelerates. Therefore, the dropout of the balancer 57B from the substrate 53 can be effectively suppressed.

[0070] In the phosphor wheel 51B, taking the extending direction D1 to the outer peripheral edge side of the upstream fin 56A, when a tangent portion that extends to the side opposite to the rotational direction RD from the intersection position is defined as the tangent L1 at the intersection of the extending direction D1 and the outer peripheral edge of the substrate 53 on the tangent of the substrate 53 at the intersection position, the intersection angle α between the extending direction D1 and the tangent L1 is 90° or less. Preferably, the intersection angle α is less than 90°. According to such a configuration, the upstream fin 56A can more easily receive the balancer 57B on which the shearing force corresponding to the inertial force F1 acts during the rotation of the phosphor wheel 51B. Therefore, the dropout of the balancer 57B from the substrate 53 can be more effectively suppressed. Further, if the intersection angle α is less than 90°, compared with the case where the intersection angle α is 90°, the gas flowing between the fins 56 during the rotation of the phosphor wheel 51B can be more discharged to the outside of the phosphor wheel 51B. For this reason, the cooling performance of the substrate 53 and the wavelength converter 54 can be enhanced.

[0071] In the phosphor wheel 51B, the intersection angle between the extending direction of the fin 56 to the outer peripheral edge side where the balancer 57B is fixed and the tangent line of the substrate 53 at the intersection position between the extending direction of the fin 56 to the outer peripheral edge side and the outer peripheral edge of the substrate 53 is 90°. That is, among the plurality of fins 56, the intersection angle α related to the upstream fin 56A sandwiching the balancer 57B and the downstream fin 56B may be 90°, and the intersection angle β related to the downstream fin 56B may be 90°, or the intersection angle related to each of the plurality of fins 56 may be 90°.

[0072] According to such a configuration, since the balancer 57B contacts the upstream fin 56A and the intersection angle α related to the upstream fin 56A is 90°, the balancer 57B on which a shearing force acts at the start of rotation of the phosphor wheel 51B can be easily received by the upstream fin 56A. Further, since the balancer 57B contacts the downstream fin 56B and the intersection angle β related to the downstream fin 56B is 90°, the balancer 57B on which a shearing force acts at the deceleration of rotation of the phosphor wheel 51B can be easily received by the downstream fin 56B. The detachment of the balancer 57B from the substrate 53 can be effectively suppressed. Furthermore, since each of the intersection angles α and β is 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 as compared with the case where the intersection angles α and β exceed 90°. Thereby, the cooling performance of the substrate 53 and the wavelength converter 54 can be enhanced.

[0073] [Modification of the Second Embodiment] In the wavelength conversion device 5B according to the second embodiment, it is assumed that the balancer 57B is fixed in contact with each of the upstream fin 56A and the downstream fin 56B. However, the present invention is not limited to this, and the balancer may contact one of the upstream fin 56A and the downstream fin 56B in the rotation direction RD with respect to the balancer and may not contact the other fin.

[0074] FIG. 12 is a view of the phosphor wheel 51C of the wavelength conversion device 5C according to the first modification of the wavelength conversion device 5B according to the second embodiment, as viewed from the -Z direction. FIG. 13 is a view of the phosphor wheel 51D of the wavelength conversion device 5D according to the second modification of the wavelength conversion device 5B according to the second embodiment, as viewed from the -Z direction. For example, the phosphor wheel 51C of the wavelength conversion device 5C shown in FIG. 12 has the same configuration and function as the phosphor wheel 51B of the wavelength conversion device 5B, except that it includes a balancer 57C instead of the balancer 57B. The phosphor wheel 51D of the wavelength conversion device 5D shown in FIG. 13 has the same configuration and function as the phosphor wheel 51B of the wavelength conversion device 5B, except that it includes a balancer 57D instead of the balancer 57B. Although not shown, each of the wavelength conversion devices 5C and 5D includes a motor 58, and the phosphor wheels 51C and 51D are rotated by the motor 58. The balancers 57C and 57D are made of the same material as the balancers 57A and 57B, and are arranged between two adjacent fins 56 in the rotation direction RD and fixed to the second surface 532, similar to the balancers 57A and 57B.

[0075] The balancer 57C shown in FIG. 12 is fixed in contact only with the upstream fin 56A and does not contact the downstream fin 56B. In the wavelength conversion device 5C, as described above, the intersection angle α related to the upstream fin 56A is preferably 90° or less, and the intersection angle α related to each fin 56 is preferably 90° or less. Further, in the wavelength conversion device 5C, the intersection angle α related to the upstream fin 56A is more preferably less than 90°, and the intersection angle α related to each fin 56 is more preferably less than 90°.

[0076] The balancer 57D shown in FIG. 13 is not in contact with the upstream fin 56A and is fixed in contact with the downstream fin 56B. In the wavelength conversion device 5D, as described above, the intersection angle β related to the downstream fin 56B is preferably 90°, and the intersection angle β related to each fin 56 is preferably 90°.

[0077] [Embodiment 3] Next, Embodiment 3 of the present disclosure will be described. The projector according to this embodiment has the same configuration as the projector 1 according to the first embodiment, but the shape of the fins provided on the phosphor wheel is different. In the following description, parts that are the same as or substantially the same as the parts already described will be given the same reference numerals and the description thereof will be omitted.

[0078] [Schematic Configuration of Projector and Light Source Device] FIG. 14 is a perspective view showing a wavelength conversion device 5E according to this embodiment. The projector according to this embodiment has the same configuration and functions as the projector 1 according to the first embodiment, except that it includes the wavelength conversion device 5E shown in FIG. 14 instead of the wavelength conversion device 5A. That is, the light source device according to this embodiment has the same configuration and functions as the light source device 3 according to the first embodiment, except that it includes the wavelength conversion device 5E instead of the wavelength conversion device 5A.

[0079] [Configuration of Wavelength Conversion Device] The wavelength conversion device 5E has the same configuration and functions as the wavelength conversion device 5A according to the first embodiment, except that the standing portions of the fins from the second surface of the wheel are different. More specifically, the wavelength conversion device 5E according to this embodiment has the same configuration and functions as the wavelength conversion device 5A, except that it includes a phosphor wheel 51E instead of the phosphor wheel 51A. That is, the wavelength conversion device 5E includes a phosphor wheel 51E and a motor 58. The wavelength conversion device 5E corresponds to an optical conversion device.

[0080] [Configuration of Phosphor Wheel] The phosphor wheel 51E includes a wheel 52E instead of the wheel 52A and also includes a balancer 57B. Note that the phosphor wheel 51E may include a balancer 57C or a balancer 57D instead of the balancer 57B. Wheel 52E has the same configuration and function as wheel 52A according to the first embodiment, except that it includes a plurality of fins 59 instead of the plurality of fins 56. That is, wheel 52E includes a substrate 53, a wavelength converter 54, a reflection part 55, and a plurality of fins 59.

[0081] [Configuration of a plurality of fins] The plurality of fins 59 have the same configuration and function as the plurality of fins 56 according to the first embodiment, except that they include an enlarged part 591. That is, 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. Each of the plurality of fins 59 extends from a portion on the rotation axis Rx side toward the outer peripheral edge of the substrate 53. The plurality of fins 59 include two fins 59A and 59B sandwiching the balancer 57B. Fin 59A is an upstream fin located in the rotation direction RD of the substrate 53 with respect to the balancer 57B, and fin 59B is a downstream fin located in the direction opposite to the rotation direction RD with respect to the balancer 57B.

[0082] Each of the plurality of fins 59 has a second end portion 562, a first end portion 561 and a connecting portion 563 (not shown in FIG. 14), and further has an enlarged part 591. The enlarged part 591 is a portion where the fin thickness increases as it approaches the second surface 532 on which the fin 59 is provided. Specifically, the enlarged part 591 is a portion where the dimension of the fin 59 in the rotation direction RD increases as it approaches the second surface 532. The outer surface of the enlarged part 591 is a planar inclined surface inclined with respect to the second surface 532. That is, the outer surface of the enlarged part 591 is a planar C surface. The enlarged portion 591 is provided on the surface of at least one of the fins 59A and 59B that faces the balancer 57B. In the present embodiment, the balancer 57B is fixed to the fin 59A with a photocurable adhesive such as an ultraviolet curable adhesive in a state of being in contact with the enlarged portion 591 of the upstream fin 59A. Further, the balancer 57B is fixed to the fin 59B with a photocurable adhesive in a state of being in contact with the enlarged portion 591 of the downstream fin 59B. As described above, the balancer 57B is fixed to the second surface 532.

[0083] In the present embodiment, the enlarged portion 591 is provided not only on each of the surface of the upstream fin 59A that faces the balancer 57B and the surface of the downstream fin 59B that faces the balancer 57B, but also on each of the surface of each fin 59 that faces the rotation direction RD and the surface of each fin 59 that faces the direction opposite to the rotation direction RD. That is, in the wavelength conversion device 5E according to the present embodiment, the enlarged portion 591 is provided on each of the surface of each of the plurality of fins 59 that faces the rotation direction RD and the surface of each of the plurality of fins 59 that faces the direction opposite to the rotation direction RD. However, not limited to this, the fin 59A may have the enlarged portion 591 only on the surface facing the balancer 57B, and the fin 59B may have the enlarged portion 591 only on the surface facing the balancer 57B.

[0084] [Effects of the Third Embodiment] The projector according to the present embodiment described above has the same effects as the projector according to the second embodiment, and further has the following effects. In the phosphor wheel 51E as the optical wheel, the balancer 57B is fixed with a photocurable adhesive in a state of being in contact with at least one of the two fins 59A and 59B. The at least one fin has an enlarged portion 591 with which the balancer 57B comes into contact, and the fin thickness increases as it goes toward the second surface 532. In the phosphor wheel 51E according to the present embodiment, the balancer 57B is fixed by a photocurable adhesive in a state of being in contact with each of the two fins 59A and 59B. Each of the fins 59A and 59B has a fin thickness that increases as it goes toward the second surface 532 and has an enlarged portion 591 with which the balancer 57B comes into contact. At least a part of the balancer 57B is in contact with the enlarged portion 591 of the fin 59A, and at least another part of the balancer 57B is in contact with the enlarged portion 591 of the fin 59B.

[0085] According to such a configuration, when applying the photocurable adhesive for fixing 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 made to spread over the photocurable adhesive. Accordingly, it is possible to facilitate curing of the photocurable adhesive, suppress the occurrence of uncured regions in the photocurable adhesive, and effectively suppress detachment of the balancer 57B from the substrate 53.

[0086] In the phosphor wheel 51E, the outer surface of the enlarged portion 591 is formed in one of a curved shape and a flat shape. In the present embodiment, the outer surface of the enlarged portion 591 is formed in a flat shape. According to such a configuration, compared to the case where the outer surface of the enlarged portion 591 is formed in a stepped shape, the thickness of the photocurable adhesive applied to the enlarged portion 591 can be made more uniform, and light can be made to spread over the photocurable adhesive. Accordingly, the occurrence of uncured regions in the photocurable adhesive can be effectively suppressed, and detachment of the balancer 57B from the substrate 53 can be more effectively suppressed.

[0087] Note that the wavelength conversion device 5E includes balancers 57B that come into contact with the upstream fin 59A and the downstream fin 59B, respectively. Each of the plurality of fins 59 has an enlarged portion 591, and the enlarged portion 591 is provided on each of the surface of each fin 59 facing the rotational direction RD and the surface facing the direction opposite to the rotational direction RD. However, not limited to this, the enlarged portion 591 may be provided on the surface of one of the fins 59A and 59B that faces the balancer 57B.

[0088] Further, the wavelength conversion device 5E may include at least one of the balancers 57A, 57C, and 57D instead of or in addition to the balancer 57B. When the wavelength conversion device 5E includes the balancer 57C that contacts the upstream fin 59A, the enlarged portion 591 may be provided only on the surface of the upstream fin 59A that faces the balancer 57C among the plurality of fins 59, or may be provided on each fin 59. When the wavelength conversion device 5E includes the balancer 57D that contacts the downstream fin 59B, the enlarged portion 591 may be provided only on the surface of the downstream fin 59B that faces the balancer 57D among the plurality of fins 59, or may be provided on each fin 59.

[0089] [Modification of the Third Embodiment] FIG. 15 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. The enlarged portion 591 is a portion where the fin thickness of the fin 59 increases as it approaches the second surface 532, and the outer surface of the enlarged portion 591 is assumed to be a planar inclined surface inclined with respect to the second surface 532. However, it is not limited to this. For example, as shown in FIG. 15, the plurality of fins 59 included in the phosphor wheel 51E of the wavelength conversion device 5E may include an enlarged portion 592 instead of the enlarged portion 591. The outer surfaces facing the adjacent fins 59 in the enlarged portion 592 are formed in a curved surface shape. That is, the outer surface of the enlarged portion 592 is a curved R surface. More specifically, the outer surface of the enlarged portion 592 is a concave curved surface. Even when a balancer is provided so as to contact at least one of the upstream fin 59A and the downstream fin 59B having the curved surface-shaped enlarged portion 592, the same effect as the case where the balancer is provided so as to contact at least one of the fins 59A and 59B having the planar enlarged portion 591 can be achieved.

[0090] [Fourth Embodiment] Next, a fourth embodiment of the present disclosure will be described. The projector according to the present embodiment has the same configuration as the projector according to the first embodiment, but is different in that the substrate included in the phosphor wheel has a stepped portion and the balancer is disposed on the stepped portion. In the following description, parts that are the same as or substantially the same as the parts already described will be denoted by the same reference numerals and the description thereof will be omitted.

[0091] [Configuration of Projector and Light Source Device] FIG. 16 is a perspective view showing a wavelength conversion device 5F according to the present embodiment. The projector according to the present embodiment has the same configuration and functions as the projector 1 according to the first embodiment, except that it includes the wavelength conversion device 5F shown in FIG. 16 instead of the wavelength conversion device 5A. That is, the light source device according to the present embodiment has the same configuration and functions as the light source device 3 according to the first embodiment, except that it includes the wavelength conversion device 5F instead of the wavelength conversion device 5A.

[0092] [Configuration of Wavelength Conversion Device] The wavelength conversion device 5F has the same configuration and functions as the wavelength conversion device 5A according to the first embodiment, except that the substrate has a stepped portion and the stepped portion suppresses the movement of the adhesive toward the rotation axis Rx side. More specifically, the wavelength conversion device 5F according to the present embodiment has the same configuration and functions as the wavelength conversion device 5A, except that it includes a phosphor wheel 51F instead of the phosphor wheel 51A. The wavelength conversion device 5F corresponds to an optical conversion device.

[0093] [Configuration of Phosphor Wheel] The phosphor wheel 51F corresponds to an optical wheel. The phosphor wheel 51F includes a wheel 52F and a balancer 57B. Note that the phosphor wheel 51F may include at least any one of balancers 57A, 57C, and 57D instead of or in addition to the balancer 57B. The wheel 52F has the same configuration and function as the wheel 52A, except that the wheel 52F includes a substrate 53F instead of the substrate 53. That is, the wheel 52F includes a substrate 53F, a wavelength converter 54, a reflection part 55, and a plurality of fins 56. Note that the wheel 52F may include a plurality of fins 59 having enlarged parts 591 and 592 shown in the third embodiment instead of the plurality of fins 56. Further, among the plurality of fins 56, two fins 56A and 56B sandwiching the balancer 57B may include enlarged parts similar to the enlarged parts 591 and 592.

[0094] [Configuration of Substrate] The substrate 53F has the same configuration and function as the substrate 53, except that the substrate 53F further has a stepped part 535. That is, the substrate 53F has a second surface 532, a first surface 531 (not shown in FIG. 16), an opening 533, a protrusion 534, and further has a plurality of stepped parts 535. Each of the plurality of stepped parts 535 is a recess provided between two adjacent fins 56 among the plurality of fins 56 on the second surface 532 and at a portion on the outer peripheral edge side of the substrate 53F. That is, the thickness of the substrate 53F at the stepped part 535 is smaller than the thickness of the substrate 53F at a portion other than the stepped part 535. In the present embodiment, the stepped part 535 is continuously formed up to the outer peripheral edge of the substrate 53F. However, the present invention is not limited to this, and the stepped part 535 may be a recess provided between the inner peripheral edge and the outer peripheral edge of the substrate 53F. A balancer is provided on at least one of the plurality of stepped parts 535. For example, when the phosphor wheel 51F includes the balancer 57B, the balancer 57B is disposed on the stepped part 535 so as to be in contact with each of the upstream fin 56A and the downstream fin 56B, and is fixed to each of the fins 56A, 56B, and the stepped part 535 with an optical curable adhesive or the like.

[0095] [Effect of the Fourth Embodiment] The projector according to the present embodiment described above has the same effects as those of the second embodiment, and also has the following effects. In the phosphor wheel 51F as the optical wheel, the substrate 53F has a stepped portion 535 provided on the outer peripheral edge side at the second surface 532. The thickness of the substrate 53F in the stepped portion 535 is smaller than the thickness of the substrate 53F in the portion other than the stepped portion 535. The balancer included in the phosphor wheel 51F is fixed to the stepped portion 535 with an optical curable adhesive. According to such a configuration, it is possible to suppress the occurrence of curing defects in the optical curable adhesive due to the flow of the optical curable adhesive toward the center side of the substrate 53F before the optical curable adhesive cures. Therefore, it is possible to suppress a reduction in the fixing strength of the balancer to the substrate 53F. In addition, since the movement of the optical curable adhesive toward the center side of the substrate 53F can be suppressed, it is possible to suppress the displacement of the position of the balancer.

[0096] [Fifth Embodiment] Next, a fifth embodiment of the present disclosure will be described. The projector according to the present embodiment has the same configuration as the projector 1 according to the first embodiment, but is different in that it includes a color wheel as an optical conversion device. In the following description, parts that are the same as or substantially the same as the parts already described will be denoted by the same reference numerals and the description thereof will be omitted.

[0097] [Configuration of the Projector] FIG. 17 is a schematic diagram showing the configuration of an image projection device 7 included in the projector 1G according to the present embodiment. The projector 1G according to the present embodiment has the same configuration and functions as the projector 1 according to the first embodiment, except that it includes the image projection device 7 shown in FIG. 17 instead of the image projection device 2.

[0098] [Configuration of the Image Projection Device] The image projection device 7 projects image light corresponding to the input image information, similar to the image projection device 2 according to 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 generation device 74, and a projection optical device 26. The light source 71 emits white illumination light toward the light conversion device 8. The light source 71 may have the same configuration as the light source device 3 described in the above-described first to fourth embodiments, or may have other configurations.

[0099] 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 generation device 74. The image generation device 74 modulates the light incident from the second reflecting member 73 to generate image light. Red light, green light, and blue light are sequentially incident on the image generation device 74 from the light conversion device 8 via the respective reflecting members 72 and 73. The image generation device 74 generates a red image during the period when red light is incident, a green image during the period when green light is incident, and a blue image during the period when blue light is incident. In the present embodiment, the image generation device 74 is configured by a DMD (Digital Micromirror Device). The projection optical device 26 projects the image generated by the image generation device 74.

[0100] [Configuration of the light conversion device] FIG. 18 is a plan view of the light conversion device 8 as viewed from the light incident side. 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 the present embodiment, the light conversion device 8 emits light in a wavelength range different from the wavelength range 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 among the incident illumination light. Such a light conversion device 8 includes a color wheel 81 and a motor 58 that rotates the color wheel 81.

[0101] [Configuration of the color wheel] The color wheel 81 is an optical wheel that sequentially emits red light, green light, and blue light among the illumination light incident from the light source 71 by being rotated by the motor 58. The color wheel 81 includes a wheel 82 and at least one of the balancers 57A, 57B, 57C, 57D. The wheel 82 is rotatable by the motor 58. The wheel 82 has the same configuration and function as the wheel 52A, except that it includes a wavelength changer 84 instead of the wavelength converter 54 according to the first embodiment. That is, the wheel 82 includes a substrate 53, a wavelength changer 84, a reflection part 55, and a plurality of fins 56. Note that the wheel 82 may include a plurality of fins 59 having enlarged parts 591 and 592 instead of the plurality of fins 56. Further, the substrate 53 included in the wheel 82 may not include the opening 533.

[0102] The wavelength changer 84 corresponds to a color light changer and emits light having a peak wavelength different from the peak wavelength of the incident light. That is, the wavelength changer 84 emits light in a wavelength band different from the wavelength band of the incident light. Similar to the wavelength converter 54, the wavelength changer 84 is configured in a ring shape centered on the rotation axis Rx of the wheel 82 and is fixed outside the opening 533 on the first surface 531 of the substrate 53. The wavelength changer 84 is divided into three in the circumferential direction centered on the rotation axis Rx. That is, the wavelength changer 84 has three wavelength change regions 841 arranged at equal intervals in the circumferential direction centered on the rotation axis Rx. The three wavelength change regions 841 are connected in series, whereby the wavelength changer 84 is configured in a ring shape.

[0103] The three wavelength change regions 841 include a red region 841R, a green region 841G, and a blue region 841B. When the color wheel 81 is rotated by the motor 58, the illumination light emitted from the light source 71 is sequentially incident on the red region 841R, the green region 841G, and the blue region 841B. The red-use area 841R is a color filter that absorbs green light and blue light and transmits red light among the incident illumination light. The red light transmitted through the red-use area 841R is reflected by the reflection part 55, passes through the red-use area 841R again, and is emitted from the color wheel 81. The green-use area 841G is a color filter that absorbs red light and blue light and transmits green light among the incident illumination light. The green light transmitted through the green-use area 841G is reflected by the reflection part 55, passes through the green-use area 841G again, and is emitted from the color wheel 81. The blue-use area 841B is a color filter that absorbs red light and green light and transmits blue light among the incident illumination light. The blue light transmitted through the blue-use area 841B is reflected by the reflection part 55, passes through the blue-use area 841B again, and is emitted from the color wheel 81. Thus, the wavelength converter 84 is a color filter that sequentially emits color lights in a plurality of different wavelength bands.

[0104] [Effects of the Fifth Embodiment] The projector 1G including such a light conversion device 8 exhibits the same effects as the projector 1 according to the first embodiment. The color wheel 81 as an optical wheel includes a rotatable wheel 82 and a balancer that rotates together with the wheel 82 to correct the rotational balance of the wheel 82. As the balancer, at least one of the balancers 57A, 57B, 57C, and 57D can be adopted. The wheel 82 includes a disk-shaped substrate 53, a wavelength converter 84, and a plurality of fins. As the fin, one of the fins 56 and 59 can be adopted. As described above, the substrate 53 has a first surface 531 and a second surface 532 opposite to the first surface 531. The wavelength changer 84 corresponds to a color light changer and is disposed on the first surface 531. White light is incident on the wavelength changer 84 as light in the first wavelength range. The wavelength changer 84 emits color light in a wavelength range different from that of the white light wavelength range. That is, light in the first wavelength range is incident on the wavelength changer 84, and the wavelength changer 84 sequentially emits red light, green light, and blue light. Each of the red light, green light, and blue light corresponds to light having a peak wavelength different from the peak wavelength of the incident light, in other words, light in a wavelength band different from the wavelength band of the incident light. As described above, the plurality of fins 56 are disposed on the second surface 532 and extend from the central portion of the substrate 53 toward the outer peripheral edge of the substrate 53. The same applies when a plurality of fins 59 are employed. The balancer 57A is disposed between two fins facing each other among the plurality of fins. The same applies when balancers 57B, 57C, and 57D are employed.

[0105] According to such a configuration, for example, when the balancer 57A is employed, since the balancer 57A is provided on the substrate 53, the rotational balance of the wheel 82 can be corrected. Therefore, the inertia load of the wheel 82 can be reduced. Also, for example, when the fin 56 is employed, the balancer 57A is disposed between two fins 56 facing each other among the plurality of fins 56 disposed on the second surface 532. For this reason, the area where the balancer 57A can be disposed on the substrate 53 can be expanded, so that the balancer 57A can be disposed at a position away from the rotation axis Rx of the substrate 53. Thereby, even if the weight of the balancer 57A is small, the rotational balance of the substrate 53 can be corrected and the influence of the inertia load can be reduced. In addition, it is not necessary to provide a peripheral portion on the outer peripheral edge portion of the substrate 53 where the balancer is arranged but the fins are not arranged. Therefore, the substrate 53 can be lightened, and thus the color wheel 81 can be lightened, and the color wheel 81 can be miniaturized. Further, when the diameter of the substrate provided with the peripheral portion is the same as the diameter of the substrate 53 in which the balancer 57A is arranged between the two fins 56, in the latter substrate 53, the dimension of the fin 56 extending toward the outer peripheral edge of the substrate 53 can be increased. Each wavelength changing region 841 absorbs a part of the incident light and thus becomes hot. Such heat is transmitted to the fins 56 through the substrate 53 and dissipated, so that by increasing the dimension of the fins 56, the cooling efficiency of the substrate 53 provided with the wavelength changer 84 can be increased. Such an effect is the same when the balancers 57B, 57C, and 57D are employed in the color wheel 81, and is also the same when the fins 59 are employed in the color wheel 81.

[0106] On the other hand, when the balancers 57B, 57C, and 57D are employed in the color wheel 81, the same effects as those of the projector according to the second embodiment described above can be achieved. Also, when a plurality of fins 59 are employed in the color wheel 81, the same effects as those of the projector according to the third embodiment described above can be achieved. Furthermore, when the color wheel 81 includes the substrate 53F instead of the substrate 53, the same effects as those of the projector according to the fourth embodiment described above can be achieved.

[0107] In the color wheel 81, the wavelength changer 84 is a color light changer, and more specifically, it is a color filter that emits light in a predetermined wavelength band among the incident light. According to such a configuration, a color wheel 81 capable of achieving the effects of the optical wheel described above can be configured.

[0108] [Modifications of the Embodiment] The present disclosure is not limited to the above-described embodiments, and modifications, improvements, etc. within the scope that can achieve the object of the present disclosure are included in the present disclosure. In each of the above embodiments, it was assumed that the balancer 57A was fixed to the second surface 532, and the balancer 57B was fixed to each of the second surface 532, the upstream fins 56A and 59A, and the downstream fins 56B and 59B. Also, it was assumed that the balancer 57C was fixed to each of the second surface 532 and the upstream fins 56A and 59A, and the balancer 57D was fixed to each of the second surface 532 and the downstream fins 56B and 59B. However, the present disclosure is not limited to this, and when the balancer is fixed to the fin, the balancer does not necessarily have to be fixed to the second surface 532.

[0109] In the first to fourth embodiments above, the wavelength conversion devices 5A, 5B, 5C, 5D, 5E, and 5F as the light conversion devices were assumed to be reflective wavelength conversion devices having a reflection portion 55 and emitting fluorescence in a direction opposite to the incident direction of the excitation light. In the fifth embodiment above, the light conversion device 8 was assumed to be a reflective light conversion device having a reflection portion 55 and emitting red, green, and blue light in a direction opposite to the incident direction of white light. However, the present disclosure is not limited to this, and the light conversion device of the present disclosure may be a transmissive light conversion device that emits light having a changed or converted wavelength along the incident direction of light. For example, the wavelength conversion devices 5A, 5B, 5C, 5D, 5E, and 5F according to the first to fourth embodiments may employ a substrate 53 having light transmissivity and may not be provided with the reflection portion 55. Also, for example, in the light conversion device 8 according to the fifth embodiment, the wavelength changer 84 may be provided outside the substrate 53 when viewed from the incident side of white light, and the substrate 53 may not be provided with the reflection portion 55.

[0110] In the first to fourth embodiments above, the wavelength conversion devices 5A, 5B, 5C, 5D, 5E, and 5F as the light conversion devices were assumed to be employed in the light source device 3 provided in the projector. In the fifth embodiment above, the light conversion device 8 was assumed to be employed in the image projection device 7 provided in the projector 1G. However, the present disclosure is not limited to this, and the light conversion device of the present disclosure may be employed in an electronic device other than a projector, and may be employed in, for example, a lighting device.

[0111] In the above-described first to fourth embodiments, the projector is assumed to include three light modulation elements 243R, 243G, and 243B. However, the present disclosure is not limited thereto, and can also be applied to projectors including two or less or four or more light modulation elements. In the above-described fifth embodiment, the projector 1G is assumed to include one image generation device 74. That is, the projector 1G is assumed to include one light modulation element. However, the present disclosure is not limited thereto, and the projector 1G may include a plurality of light modulation elements.

[0112] In the above-described first to fourth embodiments, the image projection device 2 is assumed to be configured in a substantially L shape as shown in FIG. 1. However, the present disclosure is not limited thereto, and the image projection device 2 may be configured in a substantially U shape, for example. That is, the configuration of the image projection device constituting the projector is not limited to the above. The same applies to the projector 1G according to the fifth embodiment.

[0113] In the above-described first to fourth embodiments, the light modulation element 243 included in the image generation device 24 is assumed to be configured by a transmissive liquid crystal panel in which the light incident surface and the light exit surface are different. However, the present disclosure is not limited thereto, and the light modulation device constituting the image generation device 24 may be configured by a reflective liquid crystal panel in which the light incident surface and the light exit surface are the same. Further, any light modulation device that can modulate an incident light beam to form an image according to image information may use a light modulation element other than liquid crystal, such as a device using a micromirror such as DMD. In the above-described fifth embodiment, the image generation device 74 is assumed to be configured by a DMD. However, the present disclosure is not limited thereto, and the image generation device 74 may be configured to include at least one liquid crystal panel.

[0114] [Summary of the Present Disclosure] The summary of the present disclosure is appended below. [Appendix 1] A rotatable wheel, A balancer that rotates with the wheel and corrects the rotational balance of the wheel. The wheel A disk-shaped substrate having a first surface and a second surface opposite to the first surface. A color light modifier disposed on the first surface and emitting light having a peak wavelength different from the peak wavelength of the incident light. A plurality of fins disposed on the second surface and extending from a central portion 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. An optical wheel characterized by the above.

[0115] According to such a configuration, since the balancer is provided on the substrate, the rotational balance of the wheel can be corrected. Therefore, the inertia load of the wheel can be reduced. Further, the balancer is disposed between two fins facing each other among the plurality of fins disposed on the second surface. For this reason, the area where the balancer can be disposed on the substrate can be expanded, so that the balancer can be disposed at a position away from the rotation axis of the substrate. Thereby, even if the weight of the balancer is small, the rotational balance of the substrate can be corrected and the influence of the inertia load can be reduced. In addition, it is not necessary to provide an outer peripheral edge portion where the balancer is disposed but the fins are not disposed at the outer peripheral edge portion of the substrate. That is, it is not necessary to provide an outer peripheral edge portion such as a flange for disposing the balancer on the substrate. Therefore, the weight of the substrate can be reduced, and thus the weight of the optical wheel can be reduced, and the optical wheel can be miniaturized. Further, when the diameter of the substrate provided with the peripheral portion is the same as the diameter of the substrate on which the balancer is disposed between the two fins, in the latter substrate, the dimensions of the fins extending toward the outer peripheral edge of the substrate can be increased. Thereby, the cooling efficiency of the substrate provided with the color light modifier can be enhanced.

[0116] [Appendix 2] In the optical wheel according to Appendix 1, The balancer is disposed at a portion on the outer peripheral edge side of the substrate. Optical wheel, characterized in that. According to such a configuration, since the balancer is provided at a portion on the outer peripheral edge side of the substrate, compared with the case where the balancer is disposed on the center side of the substrate, it is possible to reduce the weight of the balancer, and thus, reduce the weight of the optical wheel and reduce the inertia load.

[0117] [Appendix 3] In the optical wheel according to Appendix 1 or Appendix 2, The balancer is fixed to at least one of the two fins. Optical wheel, characterized in that. Here, when the optical wheel starts rotating and decelerates, a large force is applied in the tangential direction of the substrate. Therefore, in order to suppress the peeling of the balancer from the substrate, it is necessary to firmly fix the balancer to the substrate. On the other hand, since the balancer is fixed to at least one of the above fins, even when a large shearing force acts on the balancer at least at one of the start and deceleration of the rotation of the optical wheel, the fin can receive the balancer on which the shearing force acts. Therefore, the dropout of the balancer from the substrate can be suppressed.

[0118] [Appendix 4] In the optical wheel according to Appendix 3, The balancer is fixed to the upstream fin disposed in the rotation direction of the wheel with respect to one of the two fins. Optical wheel, characterized in that. According to such a configuration, the tangential force acting on the balancer at the start of rotation is greater than the tangential force acting on the balancer at the time of rotational deceleration. Therefore, among the two fins sandwiching the balancer, since the balancer is fixed to the upstream fin arranged in the rotational direction of the wheel, the upstream fin can receive the balancer on which the shearing force acts. Accordingly, the dropout of the balancer from the substrate can be effectively suppressed.

[0119] [Appendix 5] In the optical wheel described in Appendix 4, the intersection angle between the extending direction of the upstream fin toward the outer peripheral edge side and the tangent line of the substrate at the intersection position of the extending direction of the upstream fin toward the outer peripheral edge side and the outer peripheral edge of the substrate, and the tangent line portion extending to the side opposite to the rotational direction from the intersection position is less than 90°, characterized optical wheel. According to such a configuration, it is possible to make it easier for the upstream fin to receive the balancer on which the centrifugal force acts during the rotation of the optical wheel. Accordingly, the dropout of the balancer from the substrate can be more effectively suppressed.

[0120] [Appendix 6] In the optical wheel described in Appendix 3, the intersection angle between the extending direction of the at least one fin toward the outer peripheral edge side and the tangent line of the substrate at the intersection position of the extending direction of the at least one fin toward the outer peripheral edge side and the outer peripheral edge of the substrate is 90°, characterized optical wheel. According to such a configuration, since the balancer is fixed to at least one of the two fins facing each other, when the crossing angle is 90°, at least one of the starting rotation and the decelerating rotation of the optical wheel, the balancer on which the shearing force acts can be easily received by the fin to which the balancer is fixed. For example, when the balancer is fixed to the fin on the upstream side in the rotation direction of the wheel, the balancer on which the shearing force acts at the start of rotation can be received by the upstream fin. Also, for example, when the balancer is fixed to the fin on the downstream side in the rotation direction of the wheel, the balancer on which the shearing force acts at the time of decelerating rotation can be received by the downstream fin. Therefore, the detachment of the balancer from the substrate can be effectively suppressed.

[0121] [Appendix 7] In the optical wheel according to any one of Appendices 3 to 6, the balancer is fixed by a photocurable adhesive in a state of being in contact with the at least one fin, the at least one fin has a fin thickness that increases as it goes toward the second surface and has an enlarged portion with which the balancer comes into contact, characterized optical wheel. According to such a configuration, when applying the photocurable adhesive for fixing the balancer to the fin, the thickness of the photocurable adhesive can be made substantially uniform. For this reason, when curing the photocurable adhesive, light can be made to spread through the photocurable adhesive. Therefore, the photocurable adhesive can be easily cured, so that the occurrence of uncured regions in the photocurable adhesive can be suppressed, and the detachment of the balancer from the substrate can be effectively suppressed.

[0122] [Appendix 8] In the optical wheel according to Appendix 7, the outer surface of the enlarged portion is formed in one of a curved shape and a flat shape, characterized optical wheel. According to such a configuration, compared with the case where the outer surface of the enlarged portion is formed in a stepped shape, light can be spread over the photocurable adhesive provided on the enlarged portion. Therefore, the occurrence of uncured regions in the photocurable adhesive can be effectively suppressed, and the detachment of the balancer from the substrate can be more effectively suppressed.

[0123] [Appendix 9] In the optical wheel according to any one of Appendices 1 to 8, the balancer is fixed to the second surface. An optical wheel characterized by this. According to such a configuration, the balancer disposed between the two fins can be stably disposed on the substrate.

[0124] [Appendix 10] In the optical wheel according to any one of Appendices 1 to 9, the substrate has a stepped portion provided on the outer peripheral edge side on the second surface, the thickness of the substrate at the stepped portion is smaller than the thickness of the substrate at portions other than the stepped portion, the balancer is fixed to the stepped portion by a photocurable adhesive. An optical wheel characterized by this. According to such a configuration, it is possible to suppress the photocurable adhesive from flowing toward the center side of the substrate before the photocurable adhesive cures, and to suppress the occurrence of curing defects in the photocurable adhesive. Therefore, it is possible to suppress a reduction in the fixing strength of the balancer to the substrate. Further, since the movement of the photocurable adhesive toward the center side of the substrate can be suppressed, it is possible to suppress the displacement of the position of the balancer.

[0125] [Appendix 11] In the optical wheel according to any one of Appendices 1 to 10, the color light modifier is a wavelength converter that converts the wavelength of incident light. An optical wheel characterized by this. According to such a configuration, a phosphor wheel capable of achieving the effects of the above-described optical wheel can be configured.

[0126] [Appendix 12] In the optical wheel according to any one of Appendices 1 to 10, the color light converter is a color filter that emits light in a predetermined wavelength band among the incident light, characterized optical wheel. According to such a configuration, a color wheel capable of achieving the effects of the above-described optical wheel can be configured.

[0127] [Appendix 13] An optical wheel according to any one of Appendices 1 to 12, and a motor for rotating the optical wheel, characterized in that it comprises. characterized optical conversion device. According to such a configuration, the same effects as those of the above-described optical wheel can be achieved. In addition, the inertia load of the optical wheel can be reduced, and the weight of the optical wheel can be reduced. Therefore, even a low-torque motor can rotate the optical wheel. For this reason, a low-torque motor can be adopted for the optical conversion device, and the cost of the motor adopted for the optical conversion device can be reduced.

[0128] [Appendix 14] An optical conversion device according to Appendix 13, and a light source for emitting light incident on the optical conversion device, an image generation device for generating image light from the light emitted from the optical conversion device, a projection optical device for projecting the generated image light, characterized in that it comprises. characterized projector. According to such a configuration, the same effects as those of the above-described optical 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 configured.

Explanation of Signs

[0129] 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 portion, 54... Wavelength conversion body (color light changing body), 55... Reflection 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... Insertion hole, 59... Fin, 59A... Fin (upstream fin), 59B... Fin (downstream fin), 591, 592... Enlarged portion, 7... Image projection device, 71... Light source, 74... Image generation device, 8... Light conversion device, 81... Color wheel (optical wheel), 82... Wheel, 84... Wavelength changing body (color light changing body).

Claims

1. A rotatable wheel and, A balancer that rotates with the wheel and corrects the rotational balance of the wheel, The wheel is A disc-shaped substrate having a first surface and a second surface opposite to the first surface, A color light modifier disposed on the first surface and emitting light having a peak wavelength different from that of the incident light, A plurality of fins disposed on the second surface and extending from a central portion 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, An optical wheel characterized by the above.

2. In the optical wheel according to Claim 1, The balancer is disposed at a portion on the outer peripheral edge side of the substrate, An optical wheel characterized by the above.

3. In the optical wheel according to Claim 1, The balancer is fixed to at least one of the two fins, An optical wheel characterized by the above.

4. In the optical wheel according to Claim 3, The balancer is fixed to an upstream fin disposed in the rotational direction of the wheel with respect to one of the two fins, An optical wheel characterized by the above.

5. In the optical wheel according to Claim 4, The intersection angle between the extending direction of the upstream fin toward the outer peripheral edge side and the tangent line of the substrate at the intersection position of the extending direction of the upstream fin toward the outer peripheral edge side and the outer peripheral edge of the substrate and extending from the intersection position to the side opposite to the rotational direction is less than 90°, An optical wheel characterized by the above.

6. In the optical wheel according to Claim 3, The intersection angle between the extending direction of the at least one fin toward the outer peripheral edge side and the tangent line of the substrate at the intersection position of the extending direction of the at least one fin toward the outer peripheral edge side and the outer peripheral edge of the substrate is 90°, An optical wheel characterized by the above.

7. In the optical wheel according to any one of Claims 3 to 6, The balancer is fixed by a photocurable adhesive in a state of being in contact with the at least one fin, The at least one fin has an enlarged portion where the fin thickness increases toward the second surface and where the balancer contacts, An optical wheel characterized by the above.

8. In the optical wheel according to Claim 7, The outer surface of the enlarged portion is formed in one of a curved shape and a flat shape. An optical wheel characterized by this.

9. In the optical wheel according to any one of Claims 1 to 6, The balancer is fixed to the second surface. An optical wheel characterized by this.

10. In the optical wheel according to any one of Claims 1 to 6, The substrate has a stepped portion provided on the outer peripheral edge side on the second surface, The thickness of the substrate at the stepped portion is smaller than the thickness of the substrate at portions other than the stepped portion, The balancer is fixed to the stepped portion with an optical curable adhesive. An optical wheel characterized by this.

11. In the optical wheel according to any one of Claims 1 to 6, The color light changer is a wavelength converter that converts the wavelength of incident light. An optical wheel characterized by this.

12. In the optical wheel according to any one of Claims 1 to 6, The color light changer is a color filter that emits light in a predetermined wavelength band of incident light. An optical wheel characterized by this.

13. An optical wheel according to any one of Claims 1 to 6, and A motor for rotating the optical wheel, are provided. An optical conversion device characterized by this.

14. The optical conversion device according to Claim 13, and A light source that emits light incident on the optical conversion device, An image generation device that generates image light from the light emitted from the optical conversion device, A projection optical device that projects the generated image light, are provided. A projector characterized by this.

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