Light source device and projector

Abstract

To provide a light source device and projector that suppress malfunctions of optical components caused by heat. [Solution] The light source device of the present invention comprises a light source unit that emits light, an optical scanning unit that periodically scans the light emitted from the light source unit, a movable unit that is linked to the optical scanning unit, and a power supply unit that supplies power to the light source unit. The optical scanning unit has a transmissive optical element that rotates about a rotation axis extending in a direction intersecting the direction of incidence of light and scans the light incident from the light source unit. The movable unit is conductive and moves in conjunction with the rotation of the transmissive optical element. The device switches between a first state in which the light source unit and the power supply unit are electrically connected and a circuit is formed to supply power to the light source unit when the transmissive optical element is rotating, and a second state in which the electrical connection between the light source unit and the power supply unit is disconnected and power is not supplied to the light source unit when the transmissive optical element is not rotating.

Description

Technical Field

[0001] The present invention relates to a light source device and a projector.

Background Art

[0002] As a light source device used in a projector, a light source device that illuminates a light modulation device by temporally scanning the light emitted from a light emitting element on a light modulation device such as a liquid crystal panel has been proposed.

[0003] Patent Document 1 below discloses a projector including an illumination device that emits an illumination light beam, a liquid crystal panel that modulates the illumination light beam from the illumination device according to image information, a projection optical system that projects the light beam modulated by the liquid crystal panel, and a rotating prism provided between the illumination device and the liquid crystal panel. In this projector, the rotating prism scans the light emitted from the illumination device by rotating. The light scanned by the rotating prism is modulated by the liquid crystal panel and projected onto a screen.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the projector of Patent Document 1, when the rotating prism is not rotating, the light scanning stops. At this time, there is a risk that problems such as deterioration and breakage due to being exposed to high temperatures may occur due to continuous local irradiation of light on optical components such as the liquid crystal panel.

Means for Solving the Problems

[0006] To solve the above problems, a light source device according to one aspect of the present invention comprises a light source unit that emits light, an optical scanning unit that periodically scans the light emitted from the light source unit, a movable unit that is linked to the optical scanning unit, and a power supply unit that supplies power to the light source unit. The optical scanning unit rotates about a rotation axis that extends in a direction intersecting the direction of incidence of the light and has a transmissive optical element that scans the light incident from the light source unit. The movable unit is a conductive member having electrical conductivity. The movable unit moves in conjunction with the rotation of the transmissive optical element and switches between a first state in which the light source unit and the power supply unit are electrically connected and a circuit is formed to supply power to the light source unit when the transmissive optical element is rotating, and a second state in which the electrical connection between the light source unit and the power supply unit is disconnected and power is not supplied to the light source unit when the transmissive optical element is not rotating.

[0007] A projector according to one aspect of the present invention comprises a light source device according to one aspect of the present invention, an optical modulation device that modulates scanning light emitted from the optical scanning unit according to image information, and a projection optical device that projects image light emitted from the optical modulation device. [Brief explanation of the drawing]

[0008] [Figure 1] This is a plan view showing the schematic configuration of the projector according to the first embodiment. [Figure 2] A side view of the projector. [Figure 3] This is a perspective view of the second optical scanning unit and the second rotary drive device. [Figure 4] This is a schematic diagram showing the light emitted from the second light source. [Figure 5A] This is a schematic diagram illustrating the behavior of light when a transmissive optical element rotates. [Figure 5B] This is a schematic diagram showing a continuation of Figure 5A. [Figure 5C] This is a schematic diagram showing a continuation of Figure 5B. [Figure 5D] This is a schematic diagram showing a continuation of Figure 5C. [Figure 5E] This is a schematic diagram showing a continuation of Figure 5D. [Figure 5F] It is a schematic diagram showing the continuation of FIG. 5E. [Figure 6] It is a plan view showing the schematic configuration of the second rotation driving device. [Figure 7] It is a perspective view showing the configuration of the second rotation driving device. [Figure 8A] It is a cross-sectional view taken along line VIII of FIG. 7 in the first state of the second rotation driving device. [Figure 8B] It is a cross-sectional view taken along line VIII of FIG. 7 in the second state of the second rotation driving device. [Figure 9] It is an equivalent circuit diagram of the second rotation driving device. [Figure 10A] It is a cross-sectional view of the second rotation driving device in the first state in the second embodiment. [Figure 10B] It is a cross-sectional view of the second rotation driving device in the second state in the second embodiment. [Figure 11] It is an equivalent circuit diagram of the second rotation driving device in the second embodiment. [Figure 12A] It is a cross-sectional view of the second rotation driving device in the first state in the third embodiment. [Figure 12B] It is a cross-sectional view of the second rotation driving device in the second state in the third embodiment. [Figure 13] It is a perspective view showing the main part configuration of the second light source unit and the second light scanning unit.

Embodiments for Carrying Out the Invention

[0009] [First Embodiment] Hereinafter, the first embodiment of the present invention will be described with reference to the drawings. The projector of this embodiment is an example of a liquid crystal projector using a liquid crystal panel as a light modulation device. In the following drawings, in order to make each component easy to see, the scale of the dimensions may be shown differently depending on the component.

[0010] FIG. 1 is a plan view showing a schematic configuration of the projector 20 of the present embodiment. FIG. 2 is a side view showing the schematic configuration of the projector 20. In FIG. 2, for ease of viewing the drawing, only the second light source unit and the second light scanning unit are shown for the optical system in the front stage of the light modulation device. FIG. 3 is a perspective view of the second light source unit and the second light scanning unit.

[0011] As shown in FIGS. 1 and 2, the projector 20 of the present embodiment includes a light source device 10, a first reflection mirror 41, a second reflection mirror 42, a green light modulation device 43G, an emission-side polarizing plate 44G, a blue light modulation device 43B, an emission-side polarizing plate 44B, a half-wave plate 46B, a red light modulation device 43R, an emission-side polarizing plate 44R, a half-wave plate 46R, an image light combining element 45, and a projection optical device 23. Note that the projector 20 of the present embodiment includes the half-wave plates 46B and 46R, but does not necessarily have to include them.

[0012] The light source device 10 of the present embodiment includes a first light source unit 11, a second light source unit 12, a third light source unit 13, a first light scanning unit 6, a second light scanning unit 7, a third light scanning unit 8, a first rotation driving device 35, a second rotation driving device 36, and a third rotation driving device 37. Each of the light scanning units 6, 7, and 8 includes transmission optical elements 15, 16, and 17, respectively.

[0013] Hereinafter, in the drawings, explanations will be made using the XYZ orthogonal coordinate system as necessary. The X-axis is an axis parallel to the optical axis AX2 of the second light source unit 12. The optical axis AX2 of the second light source unit 12 is defined as an axis along the principal ray of the green light LG emitted from the second light source unit 12. The Y-axis is an axis orthogonal to the X-axis and is an axis along the rotation axis of each of the transmission optical elements 15, 16, and 17. The Z-axis is an axis orthogonal to the X-axis and the Y-axis. The optical axis AX1 of the first light source unit 11 is defined as an axis along the principal ray of the blue light LB emitted from the first light source unit 11. The optical axis AX3 of the third light source unit 13 is defined as an axis along the principal ray of the red light LR emitted from the third light source unit 13. The Y-axis direction of the present embodiment corresponds to the direction of the claims.

[0014] As shown in Figure 1, the first light source unit 11 emits blue light LB in the first wavelength band toward the first transmissive optical element 15. The second light source unit 12 emits green light LG in the second wavelength band toward the second transmissive optical element 16. The third light source unit 13 emits red light LR in the third wavelength band toward the third transmissive optical element 17. The first light source unit 11, the second light source unit 12, and the third light source unit 13 are arranged side by side in the Z-axis direction and emit light toward the same side (+X side). With this configuration, it is easy to standardize cooling components such as heat sinks for cooling the light source units 11, 12, and 13, and the light source device 10 can be miniaturized.

[0015] Although the basic configurations of each light source unit 11, 12, and 13 are similar, Figures 2 and 3 show the detailed configuration of the second light source unit 12. Therefore, the specific configuration will be explained below using the second light source unit 12 as a representative example.

[0016] As shown in Figures 2 and 3, the second light source unit 12 comprises a plurality of second light-emitting elements 26 and a substrate 29. The second light-emitting elements 26 are composed of laser diodes that emit light rays LG0 in the second wavelength band. Therefore, the light rays LG0 emitted from the second light-emitting elements 26 are linearly polarized laser light with coherence, a narrow beam width, and high parallelism. The second wavelength band is, for example, the green wavelength band of 530 nm ± 5 nm. That is, the light rays LG0 emitted from the second light-emitting elements 26 are green light.

[0017] Multiple second light-emitting elements 26 are arranged in a row along the Y-axis direction at predetermined intervals from one another. In this embodiment, the second light source unit 12 is equipped with five second light-emitting elements 26, but the number of second light-emitting elements 26 is not particularly limited, and it is sufficient for multiple second light-emitting elements 26 to be arranged in a row along the Y-axis direction.

[0018] Figure 4 shows a cross-section perpendicular to the direction of propagation of the green light LG emitted from the second light source unit 12. In this embodiment, since a ray LG0 is emitted from each of the five second light-emitting elements 26, the green light LG emitted from the second light source unit 12 is the entire luminous beam including the five rays LG0, as shown in Figure 4. Therefore, the outer edge of the green light LG is defined as the outer edge of the figure circumscribing the five rays LG0. The principal ray of the green light LG is defined as the ray passing through the center of the figure circumscribing the five rays LG0. In this case, the cross-sectional shape perpendicular to the principal ray of the green light LG is a band-like shape having a major axis extending along the Y-axis and a minor axis extending along the Z-axis. It is desirable that the length Lz of the minor axis of the cross-sectional shape perpendicular to the principal ray of the green light LG is approximately shorter than the length Ly of the major axis extending along the Y-axis of the green light modulation device 43G. For example, the ratio Lz / Ly, which is the length of the short axis Lz of the cross-sectional shape perpendicular to the principal ray of the green light LG and the length Ly of the long axis of the light modulator 43G for green light, is preferably 1 / 2 or less. According to this embodiment, it is possible to generate light having a cross-sectional shape with a long axis extending along the Y-axis without using an optical system such as a beam width adjustment optical system.

[0019] The substrate 29 supports a plurality of second light-emitting elements 26. Although not shown in the figures, a cooling member such as a heat sink for cooling the plurality of second light-emitting elements 26 may be provided on the side of the substrate 29 opposite to the side on which the plurality of second light-emitting elements 26 are provided.

[0020] As shown in Figure 1, the first light source unit 11 comprises a plurality of first light-emitting elements 25 and a substrate 29. The first light-emitting elements 25 are composed of laser diodes that emit light in the first wavelength band. Therefore, the light emitted from the first light-emitting elements 25 is linearly polarized with coherence, has a narrow beam width, and is laser light with high parallelism. The first wavelength band is, for example, the blue wavelength band of 450 nm ± 5 nm. That is, the light emitted from the first light-emitting elements 25 is blue light. In this embodiment, laser diodes are given as the first light-emitting elements 25, but the invention is not limited to laser diodes. Light sources such as LEDs and lamps, along with optical systems for adjusting the polarization direction of light, optical systems for adjusting the beam width, color wheels, etc., can be used to generate light rays with a ratio Lz / Ly of 1 / 2 or less, thereby replacing the laser diodes.

[0021] Multiple first light-emitting elements 25 are arranged in a row at predetermined intervals from each other along the Y-axis direction, that is, the direction perpendicular to the plane of the paper in Figure 1. The number of first light-emitting elements 25 is not particularly limited; it is sufficient that multiple first light-emitting elements 25 are arranged in a row along the Y-axis direction.

[0022] The third light source unit 13 comprises a plurality of third light-emitting elements 27 and a substrate 29. Each third light-emitting element 27 is composed of a laser diode that emits light in the third wavelength band. Therefore, the light emitted from the third light-emitting elements 27 is linearly polarized with coherence, has a narrow beam width, and is highly parallel laser light. The third wavelength band is, for example, the red wavelength band of 650 nm ± 5 nm. In other words, the light emitted from the third light-emitting elements 27 is red light.

[0023] Multiple third light-emitting elements 27 are arranged in a row at predetermined intervals from each other along the Y-axis direction, that is, the direction perpendicular to the plane of the paper in Figure 1. The number of third light-emitting elements 27 is not particularly limited; it is sufficient that multiple third light-emitting elements 27 are arranged in a row along the Y-axis direction.

[0024] Although the basic configuration of each transmitted optical element 15, 16, and 17 is similar, Figures 2 and 3 show the detailed configuration of the second optical scanning unit 7, so the specific configuration will be described below using the second optical scanning unit 7 as a representative example. Each optical scanning unit 6, 7, and 8 corresponds to an example of the "optical scanning unit" of the present invention. In other words, the light source device 10 of this embodiment is equipped with three optical scanning units.

[0025] As shown in Figures 1 to 3, the second optical scanning unit 7 is located on the optical axis AX2. The second optical scanning unit 7 periodically scans the green light LG emitted from the second light source unit 12. The second optical scanning unit 7 includes a second transmission optical element (transmission optical element) 16. The second transmission optical element 16 is located on the optical axis AX2. The second transmission optical element 16 is composed of a translucent member that is rotatably supported. Translucent materials such as optical glass such as BK7, quartz, or resin are used as the glass material for the translucent member constituting the second transmission optical element 16. The second transmission optical element 16 is rotatable about a second rotation axis C2 that extends along the Y-axis direction intersecting the X-axis direction, which is the incident direction of the green light LG. The second transmission optical element 16 periodically scans the green light LG incident from the second light source unit 12. The second rotation axis C2 is connected to a second rotation drive device 36, which consists of a motor or the like. The second transmission optical element 16 rotates about the second rotation axis C2 by the drive of the second rotation drive device 36.

[0026] As shown in Figure 3, the second transmissive optical element 16 has a third surface 16a and a fourth surface 16b that intersect the second rotation axis C2, and four second surfaces 16c that are perpendicular to the third surface 16a and the fourth surface 16b. In other words, the shape of the second transmissive optical element 16 is a regular quadrangular prism having six planes, including the third surface 16a, the fourth surface 16b, and the four second surfaces 16c. The cross-sectional shape of the second transmissive optical element 16, when cut by a plane perpendicular to the second rotation axis C2, is square. That is, the four second sides 16c have the same area, and two opposing second sides 16c are parallel to each other.

[0027] The second transmissive optical element 16 rotates about the second rotation axis C2 while transmitting the green light LG emitted from the second light source unit 12. Therefore, the second side surface 16c on which the green light LG emitted from the second light source unit 12 enters the second transmissive optical element 16 is not fixed but changes over time. In the second transmissive optical element 16, the second side surface 16c on which the green light LG emitted from the second light source unit 12 enters is called the second incident surface. The second side surface 16c from which the green light LG entering from the second incident surface is emitted is called the second exit surface. In this case, the second incident surface and the second exit surface change over time and are one of two parallel second side surfaces 16c out of four possible second side surfaces 16c.

[0028] In this specification, when two sides of a transmissive optical element are said to be parallel to each other, "parallel" refers to a case where the angle between the two sides is in the range of 0 ± 5 degrees, taking into consideration the processing accuracy of the glass material constituting the light-transmitting member, the allowable range of parallelism of light, etc.

[0029] In this embodiment, the second transmissive optical element 16 has four second sides 16c, but the number of second sides 16c does not necessarily have to be four; it is preferable that there be 2 × n (n: a natural number greater than or equal to 2). That is, it is preferable that the number of second sides 16c be an even number, such as 6 or 8. If the number of second sides 16c is even, each of the second sides 16c is parallel to the second side 16c opposite it, and there are no second sides 16c that do not have a parallel pair. As a result, the generation of stray light in the second transmissive optical element 16 is reduced, and the light utilization efficiency can be increased.

[0030] As shown in Figure 1, the first transmissive optical element (transmissive optical element) 15 is provided on the optical axis AX1. The first transmissive optical element 15 is composed of a translucent member that is rotatably supported. The first transmissive optical element 15 is rotatable about a first rotation axis C1 that extends along the Y-axis direction. The first rotation axis C1 is connected to a first rotation drive device 35. The first transmissive optical element 15 rotates about the first rotation axis C1 by the drive of the first rotation drive device 35.

[0031] The first transmission optical element 15 has a first surface 15a and a second surface 15b that intersect the first rotation axis C1, and four first side surfaces 15c that are perpendicular to the first surface 15a and the second surface 15b. The first transmission optical element 15 rotates about the first rotation axis C1 and transmits blue light LB emitted from the first light source unit 11. In the first transmission optical element 15, the first side surface 15c into which the blue light LB emitted from the first light source unit 11 is incident is called the first incident surface. The first side surface 15c that causes the blue light LB incident from the first incident surface to be emitted is called the first emission surface. The first incident surface and the first emission surface change over time and are one of two of the four first side surfaces 15c that are parallel to each other.

[0032] In this embodiment, the first transmissive optical element 15 has four first sides 15c, but the number of first sides 15c does not necessarily have to be four; it is preferable that there be 2 × m (m: a natural number greater than or equal to 2). That is, it is preferable that the number of first sides 15c be an even number, such as 6 or 8. If the number of first sides 15c is even, each of the first sides 15c is parallel to the first side 15c facing it, and there are no first sides 15c that are not parallel. As a result, the generation of stray light in the first transmissive optical element 15 is reduced, and the light utilization efficiency can be increased.

[0033] The third transmissive optical element (transmissive optical element) 17 is provided on the optical axis AX3. The third transmissive optical element 17 is composed of a light-transmitting member that is rotatably supported. The third transmissive optical element 17 is rotatable about a third rotation axis C3 that extends along the Y-axis. The third rotation axis C3 is connected to a third rotation drive device 37. The third transmissive optical element 17 rotates about the third rotation axis C3 by the drive of the third rotation drive device 37.

[0034] The third transmissive optical element 17 has a fifth surface 17a and a sixth surface 17b that intersect the third rotation axis C3, and four third side surfaces 17c that are perpendicular to the fifth surface 17a and the sixth surface 17b. The third transmissive optical element 17 transmits the red light LR emitted from the third light source unit 13 while rotating about the third rotation axis C3. In the third transmissive optical element 17, the third side surface 17c through which the red light LR emitted from the third light source unit 13 is incident is referred to as the third incident surface. The third side surface 17c that emits the red light LR incident from the third incident surface is referred to as the third emission surface. The third incident surface and the third emission surface change over time and are any one of two parallel third side surfaces 17c among the four third side surfaces 17c.

[0035] In the case of this embodiment, the third transmissive optical element 17 has four third side surfaces 17c, but the number of the third side surfaces 17c does not necessarily have to be four, and it is preferably 2×p (p: a natural number of 2 or more). That is, the number of the third side surfaces 17c is preferably an even number such as 6, 8, etc. If the number of the third side surfaces 17c is an even number, each of all the third side surfaces 17c is parallel to the third side surface 17c facing the third side surface 17c, and there is no non-parallel third side surface 17c. Thereby, the generation of stray light in the third transmissive optical element 17 is reduced, and the light utilization efficiency can be increased.

[0036] The first transmissive optical element 15, the second transmissive optical element 16, and the third transmissive optical element 17 are made of different glass materials and have different refractive indices. Specifically, the refractive index of the first transmissive optical element 15 is smaller than the refractive index of the second transmissive optical element 16, and the refractive index of the second transmissive optical element 16 is smaller than the refractive index of the third transmissive optical element 17. That is, when the refractive index of the first transmissive optical element 15 is n1, the refractive index of the second transmissive optical element 16 is n2, and the refractive index of the third transmissive optical element 17 is n3, the relationship of n1 < n2 < n3 is satisfied.

[0037] Alternatively, the first transmitting optical element 15, the second transmitting optical element 16, and the third transmitting optical element 17 may be made of quartz. In each transmitting optical element 15, 16, and 17, as the amount of light transmitted through the translucent member increases, the amount of light absorbed by the translucent member also increases, which may cause thermal distortion in the translucent member. In this case, the polarization direction of each color light LB, LG, and LR emitted from each light source unit 11, 12, and 13 becomes disordered, and the linearly polarized light incident on the translucent member becomes elliptically polarized light and is emitted from the translucent member. As a result, the effect of obtaining a predetermined contrast without providing an incident polarizer by using laser diodes in each light-emitting element 25, 26, and 27 in the projector 20 is not obtained. That is, even though laser diodes are used in each light-emitting element 25, 26, and 27, it becomes necessary to use an incident polarizer to align the polarization direction. Therefore, in order to obtain the above effect, it is desirable to use a glass material with a small Young's modulus and low coefficient of thermal expansion as a glass material with low thermal distortion, and as an example, it is desirable to use quartz.

[0038] The behavior of each color light LB, LG, and LR as they pass through each of the transmitting optical elements 15, 16, and 17 will be described below. Since the behavior of each color light LB, LG, and LR is common to all of them, the green light LG emitted from the second light source unit 12 will be used as a representative example for this explanation.

[0039] Figures 5A to 5F are schematic diagrams illustrating the behavior of the green light LG as the second transmissive optical element 16 rotates. In this example, viewed from the +Y side, the second transmissive optical element 16 rotates clockwise around the second rotation axis C2, and the diagrams show the progression of time from Figure 5A to Figure 5F.

[0040] In Figures 5A to 5F, the angle between the optical axis AX2 and the straight line M passing through the second rotation axis C2 and perpendicular to the second side surface 16c1 of the second transmitting optical element 16 is defined as the rotation angle ω of the second transmitting optical element 16. In reality, the green light LG has a predetermined luminous beam width in the Z-axis direction, but here we will focus on the behavior of the light ray LG0 traveling along the optical axis AX2.

[0041] Figure 5A shows the initial state of the second transmission optical element 16. That is, the second transmission optical element 16 is not rotating, the straight line M and the optical axis AX2 coincide, and the rotation angle ω is 0 degrees. In this case, the light ray LG0 is incident perpendicular to the second side surface 16c1, and therefore travels through the inside of the second transmission optical element 16 along the optical axis AX2 without being refracted at the second side surface 16c1. Next, the light ray LG0 is also incident perpendicular to the second side surface 16c3, which is parallel to the second side surface 16c1. Therefore, the light ray is emitted from the second transmission optical element 16 without being refracted at the second side surface 16c3 and travels along the optical axis AX2.

[0042] Next, as shown in Figure 5B, when the second transmissive optical element 16 rotates by a rotation angle ω, the light ray LG0 is incident on the second side surface 16c1 at an incident angle equal to the rotation angle ω. Therefore, the light ray LG0 is refracted in the direction shown in the figure (+Z side) and travels inside the second transmissive optical element 16. Next, the light ray LG0 is also incident on the second side surface 16c3 at a predetermined incident angle, so it is refracted at the second side surface 16c3 and emitted from the second transmissive optical element 16. At this time, since the second side surface 16c1 and the second side surface 16c3 are parallel to each other, the incident angle of the light ray LG0 with respect to the second side surface 16c1 is equal to the incident angle of the light ray LG0 with respect to the second side surface 16c3, and the refraction angle of the light ray LG0 incident on the second side surface 16c1 and the refraction angle of the light ray LG0 emitted from the second side surface 16c3 have opposite signs but equal absolute values. As a result, the refraction angle of the ray LG0 upon incidence onto the second side surface 16c1 and the refraction angle upon emission from the second side surface 16c3 cancel each other out. Consequently, the ray LG0 travels parallel to the optical axis AX2 at a position displaced by a displacement amount d to the +Z side from the optical axis AX2.

[0043] Next, as shown in Figure 5C, when the rotation angle ω of the second transmission optical element 16 becomes larger than in Figure 5B, the incident angle of the light ray LG0 increases, and the refraction angle increases. Therefore, the displacement d of the light ray LG0 from the optical axis AX2 becomes larger than in Figure 5B. Also, the state in which the light ray LG0 travels parallel to the optical axis AX2 is always maintained. Between rotation angles ω of 0 and 45 degrees, the displacement d increases monotonically with increasing rotation angle ω.

[0044] Next, as shown in Figure 5D, when the rotation angle ω of the second transmitting optical element 16 exceeds 45 degrees, the incident surface of the light ray LG0 changes from the second side surface 16c1 to the second side surface 16c2. At this time, the light ray LG0 is refracted at the second side surface 16c2, but the direction of refraction changes from the period up to Figure 5C, and it is refracted in the direction shown in the figure (towards -Z). The exit surface of the light ray LG0 also changes from the second side surface 16c3 to the second side surface 16c4, but since the second side surface 16c2 and the second side surface 16c4 are parallel to each other, the relationship in which the refraction angle when the light ray LG0 is incident on the second side surface 16c3 and the refraction angle when it is exited from the second side surface 16c4 cancel each other out remains the same as in the period up to Figure 5C. As a result, the light ray LG0 travels parallel to the optical axis AX2 at a position displaced by a displacement amount d from the optical axis AX2 to the -Z side.

[0045] Next, as shown in Figure 5E, when the rotation angle ω of the second transmissive optical element 16 becomes larger than that in Figure 5D, the incident angle of the light ray LG0 decreases, and the refraction angle decreases. Therefore, the displacement d of the light ray LG0 from the optical axis AX2 becomes smaller than in Figure 5D. Thus, between rotation angles ω of 45 degrees and 90 degrees, the displacement d decreases monotonically with increasing rotation angle ω.

[0046] Next, as shown in Figure 5F, when the rotation angle ω of the second transmissive optical element 16 becomes 90 degrees, the incident surface changes from the initial second side surface 16c1 to the second side surface 16c2, but the behavior of the light ray LG0 becomes the same as the initial state shown in Figure 5A.

[0047] Thus, if the second incident surface and the second exit surface of the second transmission optical element 16 are parallel to each other, the direction of propagation of the light ray LG0 does not change regardless of the rotation angle ω of the second transmission optical element 16, and the light ray LG0 moves in a direction parallel to the optical axis AX2 over time. When the rotation angle ω is 0 degrees, the displacement amount d of the light ray LG0 is 0, and between rotation angles ω from 0 to 45 degrees, the displacement amount d increases to either the +Z side or the -Z side. The moment the rotation angle ω exceeds 45 degrees, the absolute value of the displacement amount d remains the same, but the direction of displacement reverses, and between rotation angles ω from 45 to 90 degrees, the displacement amount d decreases, and when the rotation angle ω reaches 90 degrees, the displacement amount d becomes 0. After 90 degrees, the above behavior is repeated. Therefore, when the second transmission optical element 16 rotates once, the displacement amount d of the light ray LG0 repeats the above cycle for 4 periods. The displacement of the light ray LG0 can be appropriately set by adjusting parameters such as the refractive index and size of the second transmitting optical element 16.

[0048] The above explanation focused only on the light ray LG0 traveling along the optical axis AX2. However, in reality, as shown in Figure 3, the green light LG extends linearly in the Y-axis direction, which is perpendicular to the Z-axis direction in which the green light LG is displaced. Therefore, the green light LG is scanned within a two-dimensional illuminated region Q on the illuminated surface (optical modulator 43G). Similarly, the blue light LB and red light LR are also scanned within a two-dimensional illuminated region Q on the illuminated surface (optical modulators 43B, 43R) after being reflected by the first and second reflection mirrors 41 and 42, respectively, as the green light LG is reflected. In this way, each transmitting optical element 15, 16, and 17 scans the blue light LB, green light LG, and red light LR in a direction perpendicular to the Y-axis direction as they rotate around their respective rotation axes C1, C2, and C3, thereby scanning within a two-dimensional illuminated region Q on the illuminated surface.

[0049] As shown in Figure 1, the first reflective mirror 41 reflects the blue light LB emitted from the first transmitting optical element 15 toward the blue light modulation device 43B. In this way, the first reflective mirror 41 bends the optical path of the blue light LB emitted from the first transmitting optical element 15 from the +X direction to the -Z direction.

[0050] The second reflective mirror 42 reflects the red light LR emitted from the third transmissive optical element 17 toward the red light modulation device 43R. In this way, the second reflective mirror 42 bends the optical path of the red light LR emitted from the third transmissive optical element 17 from the +X direction to the +Z direction.

[0051] The green light modulator 43G modulates the green light LG emitted from the second transmissive optical element 16 of the light source device 10 according to image information to form green image light. The blue light modulator 43B modulates the blue light LB emitted from the first transmissive optical element 15 of the light source device 10 according to image information to form blue image light. The red light modulator 43R modulates the red light LR emitted from the third transmissive optical element 17 of the light source device 10 according to image information to form red image light. A transmissive liquid crystal panel is used in each of the light modulators 43G, 43B, and 43R. The driving method for the liquid crystal panel is not particularly limited and may include twisted nematic (TN) method, vertical alignment (VA) method, transverse field (IPS) method, etc.

[0052] As shown in Figure 1, each optical modulator 43G, 43B, and 43R is equipped with an output polarizer 44G, 44B, and 44R on its optical output side. The output polarizers 44G, 44B, and 44R transmit linearly polarized light in a specific direction.

[0053] The image photosynthesis element 45 receives image light of each color emitted from the green light modulator 43G, the blue light modulator 43B, and the red light modulator 43R, synthesizes image light corresponding to red light LR, green light LG, and blue light LB, and emits the synthesized image light toward the projection optical device 23. For example, a cross dichroic prism is used for the image photosynthesis element 45.

[0054] Half-wave plates 46B and 46R are provided between the blue light modulator 43B and the image photosynthesis element 45, and between the red light modulator 43R and the image photosynthesis element 45, respectively. The half-wave plates 46B and 46R impart a half-wave phase difference to the incident color light, rotating the polarization direction of linearly polarized light by 90 degrees. This makes it possible to make the polarization direction of the green light LG incident on the image photosynthesis element 45 different from the polarization direction of the blue light LB and red light LR incident on the image photosynthesis element 45. This configuration makes it possible to increase the efficiency of the image photosynthesis element 45.

[0055] The projection optical device 23 is composed of multiple projection lenses. The projection optical device 23 magnifies and projects the image light emitted from the image photosynthesis element 45 toward a projection surface such as a screen. As a result, an image is displayed on the projection surface.

[0056] Next, the configurations of each rotary drive unit 35, 36, and 37 will be described. Although the basic configurations of each rotary drive unit 35, 36, and 37 are similar, the specific configuration will be explained below using the second rotary drive unit 36 ​​as an example. In the following explanation, the circumferential direction centered on the second rotation axis C2 may be simply referred to as the "circumferential direction," the direction along the second rotation axis C2 may be simply referred to as the "axial direction," and the direction perpendicular to the second rotation axis C2 may be referred to as the "radial direction."

[0057] Figure 6 is a plan view showing the schematic configuration of the second rotary drive unit 36. As shown in Figure 6, the second rotary drive device 36 comprises a drive unit 50, a shaft unit 52, a conductive unit 60, a movable unit 70, and a holding member 75. The second rotary drive device 36 is provided on the -Y side of the second transmissive optical element 16. The second rotary drive unit 36 ​​is electrically connected to the power supply unit 54. The power supply unit 54 supplies power to the second light source unit 12 via the second rotary drive unit 36.

[0058] As shown in Figure 6, the drive unit 50 is provided on the -Y side of the second transmissive optical element 16. The drive unit 50 is a motor that rotates around the second rotation axis C2. The drive unit 50 rotates around the second rotation axis C2 and rotates the second transmissive optical element 16. A rotation support unit 51 is provided between the drive unit 50 and the second transmissive optical element 16. The rotation support unit 51 rotates together with the drive unit 50 around the second rotation axis C2 and supports the second transmissive optical element 16 so that it can rotate. The rotation support unit 51 is a disc-shaped part that transmits the rotation of the drive unit 50 to the second transmissive optical element 16. A shaft portion 52 extending along the Y axis is connected to the -Y side of the rotation support unit 51. The shaft portion 52 extends from the rotation support unit 51 toward the -Y side along the second rotation axis C2. The shaft portion 52 is cylindrical in shape. The shaft portion 52 is provided coaxially with the drive unit 50 and the rotation support portion 51. Therefore, the shaft portion 52 rotates around the second rotation axis C2 in conjunction with the rotation of the drive unit 50. The rotation support portion 51 is provided at one end of the shaft portion 52, and the conductive portion 60, movable portion 70, and holding member 75 are provided at the other end. Therefore, the shaft portion 52 rotates around the second rotation axis C2 by linking all the components of the second rotation drive device 36 together. As a result, the rotation of the shaft portion 52 causes the second transmitted optical element 16 to rotate around the second rotation axis C2.

[0059] A conductive section 60 is provided on the -Y side of the drive unit 50. Figure 7 is a perspective view showing the configuration of the second rotary drive unit. In Figure 7, the holding member 75 is omitted to make the internal configuration of the second rotary drive unit easier to see. As shown in Figures 6 and 7, the conductive section 60 comprises a first conductive member 61, a second conductive member 62, a third conductive member 63, a fourth conductive member 64, a first brush section 65, a second brush section 66, a third brush section 67, and a fourth brush section 68. The four conductive members 61 to 64 are arranged on the -Y side of the drive unit 50 along the second rotation axis C2 at regular intervals. The conductive section 60 electrically connects the second light source unit 12 and the power supply unit 54 via a movable section 70, which will be described later.

[0060] The first conductive member 61 is positioned furthest to the +Y side among the four conductive members. The first conductive member 61 is connected to the drive unit 50 by a shaft portion 52. The first conductive member 61 comprises a first disc portion 61a, a first connecting portion 61b, and a first shaft hole 61c. The first disc portion 61a is a circular disc shape when viewed from the Y-axis direction. A first shaft hole 61c is formed at the center of the first disc portion 61a, penetrating in the Y-axis direction. The shaft portion 52 is inserted through the first shaft hole 61c. In this embodiment, an insulating layer is provided on at least the outer circumferential surface of the shaft portion 52. Therefore, the shaft portion 52 and the first conductive member 61 are connected in an insulated state. A first sliding portion 61a1 is provided on the side surface of the first disc portion 61a, which slides against the first brush portion 65 described later. The first sliding portion 61a1 constitutes the side surface of the first disc portion 61a.

[0061] The first brush portion 65 is positioned in contact with the first sliding portion 61a1 of the first disc portion 61a. The first brush portion 65 comprises a first contact portion 65a, a first terminal portion 65b, and a first wiring portion 65c. The first contact portion 65a is a brush-shaped conductive member that contacts the first sliding portion 61a1. The first terminal portion 65b is a rod-shaped member that supports the first contact portion 65a and is made of a conductive metal member. The first wiring portion 65c is a wire extending from the end of the first terminal portion 65b opposite to the first contact portion 65a and is connected to the positive electrode 54a of the power supply unit 54. In this way, the first conductive member 61 is electrically connected to the power supply unit 54 via the first brush portion 65. In this embodiment, the first wiring section 65c is connected to the positive terminal 54a of the power supply unit 54, but it may also be connected to the negative terminal 54b of the power supply unit 54.

[0062] A first connecting portion 61b is provided radially outward from the first axial hole 61c on the surface of the first disc portion 61a facing the -Y side. The first connecting portion 61b has a bent shape at the tip of a rod with a circular cross-section as a whole. The first connecting portion 61b comprises a first portion 61b1, a second portion 61b2, and a third portion 61b3. The first portion 61b1 is the portion that extends from the surface of the first disc portion 61a toward the -Y side. The first portion 61b1 is inserted through the second avoidance hole 62d of the second conductive member 62, which will be described later. The end of the first portion 61b1 inserted through the second avoidance hole 62d is connected to the second portion 61b2 on the -Y side of the second conductive member 62. The second portion 61b2 is the portion that extends radially outward from the first portion 61b1. The third portion 61b3 is connected to the radially outer end of the second portion 61b2. The third portion 61b3 is a thin, plate-like portion that extends in the axial direction. The inner surface of the third portion 61b3 is concave and makes good contact with the first conductive member 71, which will be described later. The first conductive member 61 rotates around the second rotation axis C2 in conjunction with the rotation of the shaft portion 52 connected to the drive unit 50.

[0063] The second conductive member 62 is positioned on the -Y side of the first conductive member 61 at a constant distance. The second conductive member 62 comprises a second disc portion 62a, a contact portion 62b, a second shaft hole 62c, and a second avoidance hole 62d. The second disc portion 62a is circular in shape when viewed from the Y-axis direction. A second shaft hole 62c is formed at the center of the second disc portion 62a, penetrating in the Y-axis direction. The shaft portion 52 is inserted through the second shaft hole 62c. A second avoidance hole 62d is formed radially outward from the second shaft hole 62c in the second disc portion 62a. The second avoidance hole 62d is a hole that penetrates in the Y-axis direction. The first portion 61b1 of the first conductive member 61 is inserted through the second avoidance hole 62d. An insulating material is provided on the inner circumferential surface of the second avoidance hole 62d. As a result, the first conductive member 61 and the second conductive member 62 are connected in an insulated state. Also, the shaft portion 52 and the second conductive member 62 are connected in an insulated state. A second sliding portion 62a1 is provided on the side surface of the second disc portion 62a, which slides against the second brush portion 66, described later. The second sliding portion 62a1 constitutes the side surface of the second disc portion 62a.

[0064] The second brush portion 66 is positioned in contact with the second sliding portion 62a1 of the second disc portion 62a. The second brush portion 66 comprises a second contact portion 66a, a second terminal portion 66b, and a second wiring portion 66c. The second contact portion 66a is a brush-shaped conductive member that contacts the second sliding portion 62a1. The second terminal portion 66b is a rod-shaped member that supports the second contact portion 66a and is made of a conductive metal member. The second wiring portion 66c is a wire extending from the end of the second terminal portion 66b opposite to the second contact portion 66a and is connected to the negative electrode 54b of the power supply unit 54. In this way, the second conductive member 62 is connected to the power supply unit 54 via the second brush portion 66. In this embodiment, the second wiring section 66c is connected to the negative terminal 54b of the power supply unit 54, but it may also be connected to the positive terminal 54a of the power supply unit 54.

[0065] A contact portion 62b is provided on a part of the peripheral edge of the second disc portion 62a. The contact portion 62b is a thin plate-shaped member that extends in the axial direction. The inner surface of the contact portion 62b is concave and makes good contact with the second conductive member 72, which will be described later. The second conductive member 62 rotates around the second rotation axis C2 in conjunction with the rotation of the shaft portion 52 connected to the drive unit 50.

[0066] The third conductive member 63 is positioned on the -Y side of the second conductive member 62, at a constant distance. The third conductive member 63 has the same structure as the second conductive member 62, but is positioned 180° apart from the second conductive member 62 around an axis along the X axis. The third conductive member 63 comprises a third disc portion 63a, a contact portion 63b, a third shaft hole 63c, and a third avoidance hole 63d. The third disc portion 63a is circular in shape when viewed from the Y-axis direction. A third shaft hole 63c is formed at the center of the third disc portion 63a, penetrating in the Y-axis direction. The shaft portion 52 is inserted through the third shaft hole 63c. A third avoidance hole 63d is formed radially outward from the third shaft hole 63c in the third disc portion 63a. The third avoidance hole 63d is a hole penetrating in the Y-axis direction. The first portion 64b1 of the fourth conductive member 64, which will be described later, is inserted through the third avoidance hole 63d. An insulating material is provided on the inner circumferential surface of the third avoidance hole 63d. As a result, the third conductive member 63 and the fourth conductive member 64 are connected in an insulated state. In addition, the shaft portion 52 and the third conductive member 63 are connected in an insulated state. A third sliding portion 63a1, which slides against the third brush portion 67, which will be described later, is provided on the side surface of the third disc portion 63a. The third sliding portion 63a1 constitutes the side surface of the third disc portion 63a.

[0067] The third brush portion 67 is positioned in contact with the third sliding portion 63a1 of the third disc portion 63a. The third brush portion 67 comprises a third contact portion 67a, a third terminal portion 67b, and a third wiring portion 67c. The third contact portion 67a is a brush-shaped conductive member that contacts the third sliding portion 63a1. The third terminal portion 67b is a rod-shaped member that supports the third contact portion 67a and is made of a conductive metal member. The third wiring portion 67c is wiring that extends from the end of the third terminal portion 67b opposite to the third contact portion 67a and is connected to the second light source portion 12. In this way, the third conductive member 63 is connected to the second light source portion 12 via the third brush portion 67.

[0068] A contact portion 63b is provided on a part of the peripheral edge of the third disc portion 63a. The contact portion 63b is a thin plate-shaped member that extends in the axial direction. The inner surface of the contact portion 63b is concave and makes good contact with the first conductive member 71, which will be described later. The third conductive member 63 rotates around the second rotation axis C2 in conjunction with the rotation of the shaft portion 52 connected to the drive unit 50.

[0069] The fourth conductive member 64 is positioned on the -Y side of the third conductive member 63 at a constant distance. The fourth conductive member 64 has the same structure as the first conductive member 61, but is positioned 180° differently from the first conductive member 61 around an axis along the X axis. The fourth conductive member 64 comprises a fourth disc portion 64a, a fourth connecting portion 64b, and a fourth shaft hole 64c. The fourth disc portion 64a is a circular disc shape when viewed from the Y-axis direction. A fourth shaft hole 64c is formed in the center of the fourth disc portion 64a, penetrating in the Y-axis direction. A shaft portion 52 is inserted through the fourth shaft hole 64c, and the shaft portion 52 and the fourth conductive member 64 are connected in an insulated state. A fourth sliding portion 64a1 is provided on the side surface of the fourth disc portion 64a, which slides against the fourth brush portion 68 described later. The fourth sliding portion 64a1 constitutes the side surface of the fourth disc portion 64a.

[0070] The fourth brush portion 68 is positioned in contact with the fourth sliding portion 64a1 of the fourth disc portion 64a. The fourth brush portion 68 comprises a fourth contact portion 68a, a fourth terminal portion 68b, and a fourth wiring portion 68c. The fourth contact portion 68a is a brush-shaped conductive member that contacts the fourth sliding portion 64a1. The fourth terminal portion 68b is a rod-shaped member that supports the fourth contact portion 68a and is made of a conductive metal member. The fourth wiring portion 68c is a wiring extending from the end of the fourth terminal portion 68b opposite to the fourth contact portion 68a and is connected to the second light source portion 12. In this way, the fourth conductive member 64 is connected to the second light source portion 12 via the fourth brush portion 68.

[0071] A fourth connecting portion 64b is provided radially outward from the fourth axial hole 64c on the surface of the fourth disc portion 64a facing the +Y side. The fourth connecting portion 64b has a bent shape at the tip of a rod with a circular cross-section as a whole. The fourth connecting portion 64b comprises a first portion 64b1, a second portion 64b2, and a third portion 64b3. The first portion 64b1 is the portion that extends from the surface of the fourth disc portion 64a toward the +Y side. The first portion 64b1 is inserted through the third avoidance hole 63d of the third conductive member 63. The end of the first portion 64b1 inserted through the third avoidance hole 63d is connected to the second portion 64b2 on the +Y side of the third conductive member 63. The second portion 64b2 is the portion that extends radially outward from the first portion 64b1. The third portion 64b3 is connected to the radially outer end of the second portion 64b2. The third portion 64b3 is a thin, plate-like portion that extends in the axial direction. The inner surface of the third portion 64b3 is concave and makes good contact with the second conductive member 72. The fourth conductive member 64 rotates around the second rotation axis C2 in conjunction with the rotation of the shaft portion 52 connected to the drive unit 50.

[0072] Based on this configuration, each conductive member 61 to 64 can be electrically connected to the second light source unit 12 and the power supply unit 54 via the movable part 70.

[0073] As shown in Figure 6, the retaining member 75 is connected to the outer circumference of the shaft portion 52 in the axial direction. The retaining member 75 also functions as a retaining member that integrally holds the four conductive members 61 to 64 that constitute the conductive portion 60 with respect to the shaft portion 52. Therefore, since the retaining member 75 integrally holds the four conductive members 61 to 64 with respect to the shaft portion 52, the four conductive members 61 to 64 can be rotated together with the shaft portion 52.

[0074] Figures 8A and 8B are cross-sectional views of the second rotary drive device along the line VIII-VIII in Figure 7. As shown in Figures 8A and 8B, the retaining member 75 holds the movable part 70. The retaining member 75 has a substantially cylindrical shape. The retaining member 75 is made of a non-conductive material such as resin or plastic. The retaining member 75 includes a shaft through hole 76 and a groove 77. The shaft through hole 76 penetrates the center of the retaining member 75 in the Y-axis direction, and the shaft portion 52 is inserted through it.

[0075] The groove 77 comprises a first retaining groove 78 and a second retaining groove 79. The first retaining groove 78 and the second retaining groove 79 extend radially outward and axially from the through-hole 76. The holding member 75 rotates around the second rotation axis C2 as the drive unit 50 rotates.

[0076] As shown in Figures 6, 7, and 8, a movable part 70 is provided in the groove 77. The movable part 70 comprises a first conductive member 71 and a second conductive member 72. The first retaining groove 78 is provided with the first conductive member 71. The second retaining groove 79 is provided with the second conductive member 72. The first retaining groove 78 movably holds the first conductive member 71 along the radial direction of the retaining member 75, which is perpendicular to the second rotation axis C2. The first conductive member 71 has a cylindrical shape with its axial direction along the Y axis. The first conductive member 71 is made of a conductive material. The first conductive member 71 moves along the radial direction in conjunction with the rotation of the second transmission optical element 16 in the second optical scanning unit 7. The second retaining groove 79 movably holds the second conductive member 72 along the radial direction of the retaining member 75, which is perpendicular to the second rotation axis C2. The second conductive member 72 has a cylindrical shape with its axial direction along the Y axis. The second conductive member 72 is made of a conductive material. The second conductive member 72 moves along the radial direction in conjunction with the rotation of the second transmitted optical element 16 in the second optical scanning unit 7.

[0077] Based on this configuration, the groove 77 can guide the movement of the movable part 70 along its radial direction. As a result, the movable part 70 can move smoothly through the gap of the groove 77 without unnecessary movement.

[0078] Figure 8A is a cross-sectional view of the second rotary drive unit in its first state along the line VIII-VIII in Figure 7. Figure 8B is a cross-sectional view of the second rotary drive unit in its first state along the line VIII-VIII in Figure 7. As shown in Figure 8A, when the second transmissive optical element 16 rotates due to the rotation of the drive unit 50, the shaft 52, the conductive portion 60, and the holding member 75 rotate around the second rotation axis C2. At this time, centrifugal force acts radially outward on the first conductive member 71 and the second conductive member 72, which are held in the first retaining groove 78 and the second retaining groove 79 of the holding member 75, respectively. Therefore, as shown in Figure 8A, the first conductive member 71 and the second conductive member 72 move radially outward due to the centrifugal force. When the first conductive member 71 and the second conductive member 72 move to the radially outermost position of the first retaining groove 78 and the second retaining groove 79, they come into contact with the conductive portion 60.

[0079] In this embodiment, as described above, the movable part 70 is cylindrical, so it can move through the gap of the groove 77 while rotating along the radial direction. As a result, the movable part 70 can move smoothly through the gap of the groove 77 without getting stuck or jammed in the groove 77.

[0080] As shown in Figure 6, the +Y side end of the first conductive member 71 contacts the third portion 61b3 of the first conductive member 61. The -Y side end of the first conductive member 71 contacts the contact portion 63b of the third conductive member 63. The +Y side end of the second conductive member 72 contacts the contact portion 62b of the second conductive member 62. The -Y side end of the second conductive member 72 contacts the third portion 64b3 of the fourth conductive member 64. Each conductive member 61 to 64 electrically connects the second light source unit 12 and the power supply unit 54 via each conductive member 71 and 72. In this way, when the first conductive member 71 and the second conductive member 72 contact each conductive member 61 to 64, a circuit connecting the second light source unit 12 and the power supply unit 54 is formed.

[0081] At this time, the second light source unit 12 and the power supply unit 54 are electrically connected, so power is supplied to the second light source unit 12 from the power supply unit 54. In this embodiment, the state in which the second transmitted optical element 16 is rotating and a circuit is configured to electrically connect the second light source unit 12 and the power supply unit 54 and supply power to the second light source unit 12 is defined as the first state. The configuration of the circuit will be described later.

[0082] In Figure 8B, when the rotation of the drive unit 50 is stopped, the rotation of the second transmitted optical element 16 gradually stops. Consequently, the rotation of the shaft 52, the conductive part 60, and the holding member 75 also gradually stops. Until the rotation of the holding member 75 completely stops, the centrifugal force acting radially outward on the first conductive member 71 and the second conductive member 72 gradually weakens. In other words, gravity becomes greater than the centrifugal force acting on the first conductive member 71 and the second conductive member 72. At this time, at least one of the first conductive member 71 and the second conductive member 72 moves radially inward. Figure 8B shows the moment when, in the direction of gravity, the first conductive member 71 is positioned above the second conductive member 72. For example, as shown by the dotted line in Figure 8B, when the first conductive member 71 separates from the conductive part 60, the circuit connecting the second light source unit 12 and the power supply unit 54 is not formed. Thus, the state during which the circuit connecting the second light source unit 12 and the power supply unit 54 is not formed, and the rotation comes to a complete halt, is defined as the third state.

[0083] In Figure 8B, after the third state, when the rotation of the second transmissive optical element 16 completely stops, the rotation of the shaft portion 52, the conductive portion 60, and the holding member 75 also completely stops. At this time, the first conductive member 71 and the second conductive member 72 are no longer subjected to centrifugal force acting radially outward. In other words, only gravity acts on the first conductive member 71 and the second conductive member 72. Therefore, as shown by the solid line in Figure 8B, the first conductive member 71 or the second conductive member 72 moves radially inward due to gravity. At this time, one of the movable parts 70, which is located on the upper side in the direction of gravity, moves radially inward. As a result, one of the movable parts 70 loses contact with the conductive portion 60. In this way, when the first conductive member 71 or the second conductive member 72 is separated from the conductive portion 60, the circuit connecting the second light source unit 12 and the power supply unit 54 is not formed. In this state, the second light source unit 12 and the power supply unit 54 are not electrically connected, so the second light source unit 12 does not receive power from the power supply unit 54. Thus, when the second transmissive optical element 16 is not rotating, the electrical connection between the second light source unit 12 and the power supply unit 54 is disconnected, and the state in which no power is supplied to the second light source unit 12 is defined as the second state.

[0084] Figure 9 is an equivalent circuit diagram of the second rotational drive device. As shown in Figure 9, each conductive member 71 and 72 acts as a switch, and each conductive member 61 to 64 acts as wiring. Each conductive member 71 and 72 acts as a switch to switch from the first state to the second state when the centrifugal force accompanying the rotation of the second transmissive optical element 16 falls below the force of gravity. In this way, the first conductive member 71 and the second conductive member 72 switch between the first state and the second state. In this way, the power supply to the second light source unit 12 can be stopped when the rotation of the second transmissive optical element 16 weakens. Therefore, when the second transmissive optical element 16 is not rotating, the green light LG emitted from the second light source unit 12 continues to be incident on the green light modulation device 43G, which is a subsequent optical component. This prevents the green light modulation device 43G from being exposed to high temperatures.

[0085] As described above, the light source device 10 of this embodiment includes a second light source unit 12 that emits light, a second optical scanning unit 7 that periodically scans the light emitted from the second light source unit 12, a movable unit 70 that is linked to the second optical scanning unit 7, and a power supply unit 54 that supplies power to the second light source unit 12. The second optical scanning unit 7 rotates around a second rotation axis C2 that extends along the Y-axis direction intersecting the incident direction of the green light LG, and scans the green light LG incident from the second light source unit 12. The device has a first state in which, when the second light source unit 12 is rotating, it electrically connects the second light source unit 12 and the power supply unit 54 to supply power to the second light source unit 12, thereby forming a circuit that switches between two states: when the second light source unit 16 is rotating, it electrically connects the second light source unit 12 and the power supply unit 54 to supply power to the second light source unit 12, and when the second light source unit 16 is not rotating, it disconnects the electrical connection between the second light source unit 12 and the power supply unit 54, thereby not supplying power to the second light source unit 12. Each conductive member 71, 72, in the first state, forms a circuit that supplies power to the second light source unit 12 by contacting the conductive part 60, and in the second state, separates from each conductive member 61-64 to interrupt the circuit. Each conductive member 61-64 forms a circuit that supplies power to the second light source unit 12, and the first state and the second state are switched by the centrifugal force accompanying the rotation of the second transmissive optical element 16. The switch between the first state and the second state does not occur instantaneously, but rather via a third state.

[0086] According to the light source device 10 of this embodiment, a first state in which power is supplied to the second light source unit 12 and a second state in which power is not supplied to the second light source unit 12 can be switched in conjunction with the rotation of the second transmissive optical element 16. Therefore, when the second transmissive optical element 16 is not rotating, the supply of power to the second light source unit 12 can be stopped. As a result, since the irradiation of green light LG from the second light source unit 12 is stopped, the green light modulation device 43G, which is a downstream optical component, continues to be exposed to high temperatures, thereby preventing the green light modulation device 43G from being exposed to high temperatures. Therefore, it is possible to prevent malfunctions such as deterioration or damage to the green light modulation device 43G due to exposure to high temperatures. Furthermore, by switching between the first state and the second state as the second transmissive optical element 16 rotates, the power supply from the power supply unit 54 to the second light source unit 12 can be switched frequently, thus saving power.

[0087] Furthermore, in the light source device 10 of this embodiment, a circuit can be configured to supply power to the second light source unit 12 in instantaneous response to the movement of the second transmissive optical element 16. This improves the accuracy of switching the power supply to the second light source unit 12. In addition, the power supply can be switched without requiring a new device to control the power supply to the second light source unit 12.

[0088] Furthermore, in the light source device 10 of this embodiment, the centrifugal force associated with the rotation of the second transmissive optical element 16 can be utilized, making it easy to switch the circuit that supplies power to the second light source unit 12 without providing a new control device or the like. In addition, since each conductive member 61 to 64 is directly linked to the rotation of the second transmissive optical element 16, malfunctions and other issues can be suppressed.

[0089] Furthermore, in the light source device 10 of this embodiment, a circuit is formed only when each conductive member 71, 72 moves along each retaining groove 78, 79 and comes into contact with each of the conductive members 61 to 64. Therefore, the power supply to the second light source unit 12 can be switched more reliably.

[0090] Furthermore, in the light source device 10 of this embodiment, since the groove 77 is formed linearly along the radial direction, when the second transmissive optical element 16 is not rotating, either the first conductive member 71 or the second conductive member 72 can be separated from the respective conductive members 61-64 by gravity. This makes it easier to switch between the first state and the second state.

[0091] Although details are omitted here, in the light source device 10 of this embodiment, the first rotary drive device 35, like the second rotary drive device 36, comprises a drive unit, a shaft unit, a conductive unit, a movable unit, and a holding member. The first rotary drive device 35 is provided on the -Y side of the first transmissive optical element 15. The first rotary drive device 35 rotates about the first rotation axis C1 and rotates the first transmissive optical element 15. The first rotary drive device 35 is electrically connected to a power supply unit (not shown). The power supply unit supplies power to the first light source unit 11 via the first rotary drive device 35.

[0092] According to the light source device 10 of this embodiment, when the first transmitted optical element 15 does not rotate, the blue light LB emitted from the first light source unit 11 continues to be incident on the blue light modulation device 43B, which is a subsequent optical component, thereby suppressing exposure of the blue light modulation device 43B to high temperatures.

[0093] Furthermore, in the light source device 10 of this embodiment, the third rotational drive device 37 comprises a drive unit, a shaft unit, a conductive unit, a movable unit, and a holding member, similar to the first rotational drive device 35 and the second rotational drive device 36. The third rotational drive device 37 is provided on the -Y side of the third transmissive optical element 17. The third rotational drive device 37 rotates about the third rotation axis C3, causing the third transmissive optical element 17 to rotate. The third rotary drive unit 37 is electrically connected to a power supply unit (not shown). The power supply unit supplies power to the third light source unit 13 via the third rotary drive unit 37.

[0094] According to the light source device 10 of this embodiment, when the third transmitted optical element 17 does not rotate, the red light LR emitted from the third light source unit 13 continues to be incident on the red light modulation device 43R, which is a subsequent optical component, thereby suppressing exposure of the red light modulation device 43R to high temperatures.

[0095] The projector 20 of this embodiment includes a light source device 10, optical modulators 43B, 43G, and 43R for each color of light that modulate the light emitted from each optical scanning unit 6, 7, and 8 according to image information, and a projection optical device 23 that projects the light emitted from each color of light modulator 43B, 43G, and 43R.

[0096] According to the projector 20 of this embodiment, since it is equipped with the above-mentioned light source device 10, it is possible to provide a highly reliable projector that suppresses malfunctions such as deterioration and damage caused by exposure of the light modulation devices 43B, 43G, and 43R for each color of light to high temperatures.

[0097] [Second Embodiment] Hereinafter, a second embodiment of the present invention will be described with reference to Figures 10A, 10B, and 11. The basic configuration of the projector in this embodiment is the same as in the first embodiment, but the configuration of the light source device differs from that of the first embodiment. Figure 10A is a cross-sectional view of the second rotary drive device of the light source device in the first state in the second embodiment. Figure 10B is a cross-sectional view of the second rotary drive device of the light source device in the second embodiment in the second state. In other words, Figures 10A and 10B are cross-sectional views of the second rotary drive device. Figures 10A and 10B correspond to Figures 8A and 8B of the first embodiment. In Figures 10A and 10B, components common to the drawings of the first embodiment are denoted by the same reference numerals, and their descriptions are omitted.

[0098] As shown in Figures 10A and 10B, the second rotary drive device 236 of the light source device in this embodiment comprises a drive unit 50, a shaft unit 52, a conductive unit 260, a movable unit 270, and a holding member 275. Figures 10A and 10B show only a portion of the configuration of the second rotary drive device 236. Figure 11 is an equivalent circuit diagram of the second rotary drive device in the second embodiment. As shown in Figure 11, the second rotary drive device 236 is electrically connected to the power supply unit 254. The power supply unit 254 supplies power to the second light source unit 212 via the second rotary drive device 236.

[0099] The conductive portion 260 of this embodiment is capable of electrically connecting the second light source unit 212 and the power supply unit 254 via the movable portion 270. The conductive portion 260 of this embodiment includes a plurality of conductive members 261 and a plurality of brush portions 262.

[0100] The retaining member 275 is connected to the outer circumference of the shaft portion 52 in the axial direction. The retaining member 275 also functions as a retaining member that integrally holds the conductive portion 260 with respect to the shaft portion 52. Therefore, since the retaining member 275 integrally holds the conductive portion 260 with the shaft portion 52, the conductive portion 260 can be rotated together with the shaft portion 52.

[0101] The retaining member 275 holds the movable part 270. The retaining member 275 has a substantially cylindrical shape. The retaining member 275 is made of a non-conductive material such as resin or plastic. The retaining member 275 has a shaft through hole 276 and a groove 277. The shaft through hole 276 penetrates the center of the retaining member 275 in the Y-axis direction, and the shaft portion 52 is inserted through it.

[0102] The groove 277 comprises a first retaining groove 278, a second retaining groove 279, and a third retaining groove 280. The first retaining groove 278, the second retaining groove 279, and the third retaining groove 280 extend radially outward and axially from the shaft through hole 276. In the circumferential direction with respect to the second rotation axis C2, the first retaining groove 278, the second retaining groove 279, and the third retaining groove 280 are provided on the retaining member 275 so as to be arranged at equal intervals. In the second embodiment, the first retaining groove 278, the second retaining groove 279, and the third retaining groove 280 are arranged at 120° intervals around the Y axis. The holding member 275 rotates around the second rotation axis C2 as the drive unit 50 rotates.

[0103] A movable part 270 is provided in the groove 277. The movable part 270 comprises a first conductive member 271, a second conductive member 272, and a third conductive member 273. The first retaining groove 278 is provided with the first conductive member 271. The second retaining groove 279 is provided with the second conductive member 272. The third retaining groove 280 is provided with the third conductive member 273. The first retaining groove 278 movably holds the first conductive member 271 along the radial direction of the retaining member 275, which is perpendicular to the second rotation axis C2. The first conductive member 271 has a cylindrical shape with its axial direction along the Y axis. The first conductive member 271 is made of a conductive material. The first conductive member 271 moves along the radial direction in conjunction with the rotation of the second transmission optical element 16 in the second optical scanning unit 207. The second retaining groove 279 movably holds the second conductive member 272 along the radial direction of the retaining member 275, which is perpendicular to the second rotation axis C2. The second conductive member 272 has a cylindrical shape with its axial direction along the Y axis. The second conductive member 272 is made of a conductive material. The second conductive member 272 moves along the radial direction in conjunction with the rotation of the second transmitted optical element 16 in the second optical scanning unit 207. The third retaining groove 280 movably holds the third conductive member 273 along the radial direction of the retaining member 275, which is perpendicular to the second rotation axis C2. The third conductive member 273 has a cylindrical shape with its axial direction along the Y axis. The third conductive member 273 is made of a conductive material. The third conductive member 273 moves along the radial direction in conjunction with the rotation of the second transmission optical element 16 in the second optical scanning unit 207.

[0104] Based on this configuration, the groove 277 can guide the movement of the movable part 270 along its radial direction. As a result, the movable part 270 can move smoothly through the gap of the groove 277 without unnecessary movement.

[0105] As shown in Figure 10A, when the second transmissive optical element 16 rotates due to the rotation of the drive unit 50, the shaft 52, the conductive portion 260, and the holding member 275 rotate around the second rotation axis C2. At this time, centrifugal force acts radially outward on the first conductive member 271, the second conductive member 272, and the third conductive member 273, which are held in the first retaining groove 278, the second retaining groove 279, and the third retaining groove 280 of the holding member 275, respectively. Therefore, as shown in Figure 10A, the first conductive member 271, the second conductive member 272, and the third conductive member 273 move radially outward due to the centrifugal force. When the first conductive member 271, the second conductive member 272, and the third conductive member 273 move to the radially outermost position of the first retaining groove 278, the second retaining groove 279, and the third retaining groove 280, they come into contact with the conductive portion 60.

[0106] In this embodiment, each conductive member 261 of the conductive portion 260 electrically connects the second light source unit 212 and the power supply unit 254 via the conductive members 271, 272, and 273 of the movable portion 270. In this way, when the first conductive member 271, the second conductive member 272, and the third conductive member 273 come into contact with the conductive portion 260, a circuit is formed that connects the second light source unit 212 and the power supply unit 254.

[0107] At this time, the second light source unit 212 and the power supply unit 254 are electrically connected, so power is supplied to the second light source unit 212 from the power supply unit 254. In this embodiment, when the second transmissive optical element 16 is rotating, a first state is reached in which a circuit is configured to electrically connect the second light source unit 212 and the power supply unit 254 and supply power to the second light source unit 212. The configuration of the circuit will be described later.

[0108] In Figure 10B, when the rotation of the drive unit 50 is stopped, the rotation of the second transmitting optical element 16 gradually stops. Consequently, the rotation of the shaft 52, the conductive part 260, and the holding member 275 also gradually stops. Until the rotation of the holding member 275 completely stops, the centrifugal force acting radially outward on the first conductive member 271, the second conductive member 272, and the third conductive member 273 gradually weakens. In other words, gravity becomes greater than the centrifugal force acting on the first conductive member 271, the second conductive member 272, and the third conductive member 273. At this time, at least one of the first conductive member 271, the second conductive member 272, and the third conductive member 273 moves radially inward. Figure 10B shows the moment when, in the direction of gravity, the first conductive member 271 is positioned above the second conductive member 272 and the third conductive member 273. For example, as shown by the dotted line in Figure 10B, when the first conductive member 271 separates from the conductive portion 260, the circuit connecting the second light source unit 212 and the power supply unit 254 is not formed. In this way, the circuit connecting the second light source unit 212 and the power supply unit 254 is not formed, resulting in a third state until the rotation completely stops.

[0109] In Figure 10B, after the third state, when the rotation of the second transmissive optical element 16 completely stops, the rotation of the shaft portion 52, the conductive portion 260, and the holding member 275 also completely stops. At this time, the first conductive member 271, the second conductive member 272, and the third conductive member 273 are no longer subjected to centrifugal force acting radially outward. In other words, only gravity acts on the first conductive member 271, the second conductive member 272, and the third conductive member 273. At this time, at least one of the first conductive member 271, the second conductive member 272, and the third conductive member 273 moves radially inward due to gravity. For example, in Figure 10B, the first conductive member 271, which is located on the upper side in the direction of gravity, moves radially inward, and contact with the conductive portion 260 is lost. Thus, when at least one of the first conductive member 271, the second conductive member 272, and the third conductive member 273 is separated from the conductive portion 260, the circuit connecting the second light source unit 212 and the power supply unit 54 is not formed. In this state, the second light source unit 212 and the power supply unit 254 are not electrically connected, so the second light source unit 212 does not receive power from the power supply unit 254. Thus, when the second transmissive optical element 16 is not rotating, the electrical connection between the second light source unit 212 and the power supply unit 254 is disconnected, resulting in a second state where no power is supplied to the second light source unit 12.

[0110] As shown in Figure 11, the movable part 270 acts as a switch, and the conductive part 260 acts as wiring. Each conductive member 261 acts as a switch that switches from the first state to the second state when the centrifugal force associated with the rotation of the second transmissive optical element 16 falls below the force of gravity. In this way, the movable part 270 of this embodiment switches between the first state and the second state when the first conductive member 271, the second conductive member 272, and the third conductive member 273 come into contact with or separate from the conductive part 260.

[0111] In the configuration of the first embodiment, since there are two movable parts 70 and two grooves 77, for example, when the groove 77 stops in a horizontal position relative to the ground, the direction of gravity is perpendicular to the direction in which the movable part 70 moves. Therefore, gravity does not act strongly on the direction in which the movable part 70 moves. As a result, gravity made it difficult for the movable part 70 to move, and there was a possibility that contact with the conductive part 60 would not be severed. Compared to this case, in the second embodiment, contact with the conductive part 260 can be severed regardless of the state in which it stops. Therefore, the power supply to the second light source unit 12 can be stopped more reliably when the rotation of the second transmitted optical element 16 weakens, so that when the second transmitted optical element 16 is not rotating, the green light LG emitted from the second light source unit 12 continues to be incident on the green light modulation device 43G, which is a subsequent optical component, thereby preventing the green light modulation device 43G from being exposed to high temperatures.

[0112] [Third Embodiment] Hereinafter, a third embodiment of the present invention will be described with reference to Figures 12A and 12B. The basic configuration of the projector in this embodiment is the same as in the first embodiment, but the configuration of the light source device differs from that of the first embodiment. Figure 12A is a cross-sectional view of the second rotary drive device in the first state in the third embodiment. Figure 12B is a cross-sectional view of the second rotary drive device in the second state in the third embodiment. In other words, Figures 12A and 12B are cross-sectional views of the second rotary drive device. Figures 12A and 12B correspond to Figures 8A and 8B of the first embodiment. In Figures 12A and 12B, components common to the drawings of the first embodiment are denoted by the same reference numerals, and their descriptions are omitted.

[0113] As shown in Figures 12A and 12B, in the light source device of this embodiment, the second rotary drive device 36 comprises a drive unit 50, a shaft unit 52, a conductive unit 60, a movable unit 70, a holding member 75, and a magnet 92. The configuration other than the magnet 92 is the same as in the first embodiment. The second rotary drive unit 36 ​​is electrically connected to the power supply unit 54. The power supply unit 54 supplies power to the second light source unit 12 via the second rotary drive unit 36.

[0114] A magnet (biasing member) 92 is provided on the outer circumference of the shaft portion 52. The magnet 92 generates a magnetic force by attracting the movable portion 70. The magnet 92 biases the movable portion 70, which is provided in the groove portion 77, radially inward. When the rotation of the second transmitted optical element 16 is stopped, the movable portion 70 is attracted by the magnetic force of the magnet 92. In this case, the magnetic force is greater than the gravitational force acting on the movable portion 70, so the movable portion 70 is located radially inward. In this embodiment, the magnet 92 is provided so as to cover the outer circumference of the shaft portion 52, but it may also be provided only on the outer circumference of the shaft portion 52 that is exposed within the retaining groove 78. Furthermore, the magnet 92 only needs to be provided in at least a portion in the axial direction, and may be provided along the axial direction to correspond to the entire axial range of the movable portion 70. The magnet 92 only needs to be configured to generate a magnetic force that attracts the movable portion 70, and its shape is not particularly limited. In addition, although a magnet 92 is used as a biasing member in this embodiment, a spring that generates a spring force that pulls the movable portion 70 inward in the axial direction may be used instead of the magnet 92.

[0115] As shown in Figure 12A, when the second transmitted optical element 16 rotates due to the rotation of the drive unit 50, the shaft 52, the conductive part 60, and the holding member 75 rotate around the second rotation axis C2. At this time, centrifugal force acts radially outward on the first conductive member 71 and the second conductive member 72, which are held in the first retaining groove 78 and the second retaining groove 79 of the holding member 75, respectively. The centrifugal force acting on the movable part 70 gradually increases as the rotation of the holding member 75 speeds up. At this time, when the centrifugal force acting on the movable part 70 exceeds the magnetic force, the first conductive member 71 and the second conductive member 72 move radially outward. When the first conductive member 71 and the second conductive member 72 move to the radially outermost position of the first retaining groove 78 and the second retaining groove 79, they come into contact with the conductive part 60.

[0116] In this embodiment, the conductive portion 60 electrically connects the second light source unit 12 and the power supply unit 54 via the movable portion 70. When the first conductive member 71 and the second conductive member 72 come into contact with the conductive members 61 to 64, a circuit connecting the second light source unit 12 and the power supply unit 54 is formed.

[0117] At this time, the second light source unit 12 and the power supply unit 54 are electrically connected, so power is supplied to the second light source unit 12 from the power supply unit 54. In this embodiment, when the second transmissive optical element 16 is rotating, a first state is reached in which the second light source unit 12 and the power supply unit 54 are electrically connected, and a circuit is configured to supply power to the second light source unit 12.

[0118] In Figure 12B, when the rotation of the drive unit 50 is stopped, the rotation of the second transmitted optical element 16 gradually stops. Consequently, the rotation of the shaft 52, the conductive part 60, and the holding member 75 also gradually stops. Until the rotation of the holding member 75 completely stops, the centrifugal force acting radially outward on the first conductive member 71 and the second conductive member 72 gradually weakens. In other words, the magnetic force becomes greater than the centrifugal force acting on the first conductive member 71 and the second conductive member 72. At this time, the first conductive member 71 and the second conductive member 72 move radially inward. Figure 12B shows the moment when the first conductive member 71 is positioned above the second conductive member 72 in the direction of gravity, but the first conductive member 71 and the second conductive member 72 may be positioned in opposite directions. For example, as shown by the dotted line in Figure 12B, when the first conductive member 71 separates from the conductive part 60, the circuit connecting the second light source unit 12 and the power supply unit 54 is not formed. In this way, a circuit connecting the second light source unit 12 and the power supply unit 54 is not formed, resulting in a third state that lasts until the rotation completely stops.

[0119] In Figure 12B, after the third state, when the rotation of the second transmissive optical element 16 completely stops, the rotation of the shaft portion 52, the conductive portion 60, and the holding member 75 also completely stops. At this time, the first conductive member 71 and the second conductive member 72 are no longer subjected to centrifugal force acting radially outward. In other words, the centrifugal force is less than the magnetic force. Therefore, as shown by the solid lines in Figure 12B, the first conductive member 71 and the second conductive member 72 move radially inward due to the magnetic force. As a result, contact between the first conductive member 71 and the second conductive member 72 and the conductive portion 60 is broken. In this way, when the first conductive member 71 and the second conductive member 72 are separated from the conductive portion 60, the circuit connecting the second light source unit 12 and the power supply unit 54 is not formed. In this state, the second light source unit 12 and the power supply unit 54 are not electrically connected, so the second light source unit 12 does not receive power from the power supply unit 54. Thus, when the second transmissive optical element 16 is not rotating, the electrical connection between the second light source unit 12 and the power supply unit 54 is disconnected, resulting in a second state where no power is supplied to the second light source unit 12.

[0120] Furthermore, when the second transmissive optical element 16 rotates, the centrifugal force must be greater than the attractive force of the magnet 92. For this reason, the centrifugal force may be adjusted by adjusting the diameter of the shaft portion 52.

[0121] In the configuration of the first embodiment, since no magnet 92 is provided on the outer circumference of the shaft portion 52, when rotation stops, the movable portion 70 moves only by gravity. In this case, for example, if the groove portion 77 stops in a horizontal position relative to the ground, the direction of gravity is perpendicular to the direction in which the movable portion 70 moves. Therefore, gravity does not act strongly on the direction in which the movable portion 70 moves. As a result, the movable portion 70 is difficult to move due to gravity, and there was a possibility that contact with the conductive portion 60 would not be easily severed. Compared to this case, in the configuration of the third embodiment, contact with the conductive portion 260 can be severed by pulling the movable portion 70 radially inward by magnetic force. Therefore, when the rotation of the second transmissive optical element 16 weakens, the power supply to the second light source unit 12 can be stopped more stably. As a result, when the second transmissive optical element 16 is not rotating, the green light LG emitted from the second light source unit 12 continues to be incident on the subsequent optical component, the green light modulation device 43G, effectively suppressing exposure of the green light modulation device 43G to high temperatures.

[0122] [Fourth Embodiment] A fourth embodiment of the present invention will be described below with reference to Figure 13. The basic configuration of the projector in this embodiment is the same as in the first embodiment, but the configuration of each light source unit and each optical scanning unit of the light source device differs from that of the first embodiment. In the following, the second light source unit and the second optical scanning unit will be used as an example for explanation, and the configurations of the first light source unit and the first optical scanning unit and the third light source unit and the third optical scanning unit will not be explained.

[0123] Figure 13 is a perspective view showing the main components of the second light source unit and the second optical scanning unit. In Figure 13, components common to the first embodiment are denoted by the same reference numerals, and their descriptions are omitted. As shown in Figure 13, in the light source device 100 of this embodiment, the second light source unit 32 is equipped with one light-emitting element 32a. Therefore, the green light LG emitted from the second light source unit 32 is composed of a single ray.

[0124] The second optical scanning unit 107 of this embodiment includes a second transmission optical element 16, a second rotary drive device 36, a downstream transmission optical element 56 arranged downstream of the second transmission optical element 16, and a rotary drive device 95 consisting of a motor or the like that drives the downstream transmission optical element 56. Power is supplied to the second light source unit 32 in conjunction with the rotation of the second rotary drive device 36.

[0125] The downstream transmission optical element 56 has the same configuration as the second transmission optical element 16, but is installed in a position where the second transmission optical element 16 is rotated 90 degrees around the X-axis. The rotation drive device 95 is a motor that rotates the downstream transmission optical element 56 around a rotation axis C4 that extends along the Z-axis direction. In this embodiment, since the green light LG passes through two transmissive optical elements 16 and 56, the green light LG is displaced in two mutually orthogonal directions over time. Specifically, as shown in Figure 13, the green light LG emitted from the second light source unit 32 is scanned in the Z-axis direction by the second transmissive optical element 16 and scanned in the Y-axis direction, which is orthogonal to the Z-axis direction, by the downstream transmissive optical element 56. That is, the green light LG emitted from the second light source unit 32 is scanned within a two-dimensional illuminated area Q (green light optical modulator 43G) on the illuminated surface by the second transmissive optical element 16 and the downstream transmissive optical element 56.

[0126] [Effects of the fourth embodiment] According to the light source device of this embodiment, even when using a second optical scanning unit 107 that scans a single green light beam LG emitted from the second light source unit 32 in two directions, it is possible to switch between a first state in which power is supplied to the second light source unit 32 and a second state in which power is not supplied to the second light source unit 32 in conjunction with the rotation of the second transmissive optical element 16. Therefore, when the second transmissive optical element 16 is not rotating, the green light beam LG emitted from the second light source unit 12 continues to be incident on the green light modulation device 43G, thereby preventing the green light modulation device 43G from being exposed to high temperatures. Alternatively, instead of a configuration that links the rotation of the second transmissive optical element 16, a configuration may be adopted in which the first and second states are switched in conjunction with the rotation of the downstream transmissive optical element 56.

[0127] [Summary of this disclosure] A summary of this disclosure is provided below.

[0128] (Note 1) A light source that emits light, A light scanning unit that periodically scans the light emitted from the light source unit, A movable part that is linked to the optical scanning unit, A power supply unit that supplies power to the light source unit, Equipped with, The optical scanning unit has a transmissive optical element that rotates about a rotation axis extending in a direction intersecting the direction of incidence of the light, and scans the light incident from the light source unit. The movable part has conductivity, The movable part moves in conjunction with the rotation of the transmissive optical element, When the transmitted optical element is rotating, a first state is formed in which the light source unit and the power supply unit are electrically connected and a circuit is configured to supply power to the light source unit, A light source device that switches between a second state in which the electrical connection between the light source unit and the power supply unit is disconnected and power is not supplied to the light source unit when the transmitted optical element is not rotating.

[0129] This light source device configuration allows switching between a first state in which power is supplied to the light source and a second state in which power is not supplied to the light source, in conjunction with the rotation of the transmissive optical element. Therefore, when the transmissive optical element is not rotating, the power supply to the light source can be stopped. As a result, since the irradiation of light from the light source is stopped, it is possible to prevent, for example, optical components from being exposed to high temperatures due to continuous light irradiation. Therefore, it is possible to prevent malfunctions such as deterioration or damage to optical components caused by exposure to high temperatures. Furthermore, by switching between the first and second states as the transmissive optical element rotates, the power supply from the power unit to the light source can be switched frequently, thus saving power.

[0130] (Note 2) The system further includes a conductive portion that allows the light source unit and the power supply unit to be electrically connected via the movable portion, The light source device as described in Appendix 1, wherein the movable part, in the first state, constitutes a circuit that supplies power to the light source by contacting the conductive part, and in the second state, disconnects the circuit by moving away from the conductive part.

[0131] This configuration allows for the creation of a circuit that instantly responds to the movement of the transmissive optical element and supplies power to the light source. Therefore, the accuracy of switching the power supply to the light source can be improved. Furthermore, the power supply can be switched without requiring a new device to control the power supply to the light source.

[0132] (Note 3) A shaft portion is connected to a drive unit that rotates the transmitted optical element of the optical scanning unit, and extends along the rotation axis, The system further comprises a holding member connected to the outer circumference of the shaft portion and holding the movable portion, The light source device according to Appendix 1 or Appendix 2, wherein the holding member has a groove that movably holds the movable part along a radial direction perpendicular to the rotation axis.

[0133] With this configuration, the groove can guide the movement of the movable part along its radial direction. As a result, the movable part can move smoothly through the gap of the groove without unnecessary movement.

[0134] (Note 4) The light source device according to any one of the appendices 1 to 3, wherein the movable part has a cylindrical conductive member.

[0135] With this configuration, the cylindrical conductive member can move through the gap in the groove while rotating along the radial direction. As a result, the conductive member can move smoothly through the gap in the groove without getting stuck or jammed.

[0136] (Note 5) The light source device according to any one of the appendices 1 to 4, wherein the movable part switches between the first state and the second state by centrifugal force accompanying the rotation of the transmissive optical element.

[0137] This configuration allows for the use of centrifugal force generated by the rotation of the transmissive optical element, making it easy to switch the power supply circuit to the light source without the need for new control devices. Furthermore, since the movable part is directly linked to the rotation of the transmissive optical element, malfunctions can be suppressed.

[0138] (Note 6) The light source device as described in Appendix 5, wherein the movable part switches from the first state to the second state when the centrifugal force falls below gravity.

[0139] In this configuration, the movable part acts as a switch that switches from the first state to the second state when the centrifugal force accompanying the rotation of the transmissive optical element falls below the force of gravity. In this way, the power supply to the light source can be stopped when the rotation of the transmissive optical element weakens, so that when the transmissive optical element is not rotating, the light emitted from the light source continues to incident on the subsequent optical components, thereby preventing the optical components from being exposed to high temperatures.

[0140] (Note 7) The movable part is further provided with a biasing member that biases it toward the rotation axis, The biasing member generates an attractive force that pulls the movable part, The light source device as described in Appendix 5, wherein the movable part switches from the first state to the second state when the centrifugal force falls below the attractive force.

[0141] With this configuration, the movable part can be pulled radially inward by an attractive force, thereby cutting off contact with the conductive part. Therefore, when the rotation of the transmissive optical element weakens, the power supply to the light source can be stopped more stably, and when the transmissive optical element is not rotating, the light emitted from the light source continues to incident on the subsequent optical components, effectively suppressing exposure of the optical components to high temperatures.

[0142] (Note 8) The biasing member is a magnet, The magnet generates a magnetic force using the movable part as an attractive force, The light source device as described in Appendix 7, wherein the movable part switches from the first state to the second state when the centrifugal force falls below the magnetic force.

[0143] With this configuration, the movable part can be attracted radially inward by magnetic force. Therefore, contact with the conductive part can be eliminated with a simple configuration. Thus, when the rotation of the transmitted optical element weakens, the power supply to the light source can be stopped more stably, and when the transmitted optical element is not rotating, the light emitted from the light source continues to incident on the subsequent optical components, effectively suppressing exposure of the optical components to high temperatures.

[0144] (Note 9) The movable part has a first conductive member and a second conductive member, The light source device according to Appendix 3, wherein the groove portion has a first retaining groove for holding the first conductive member and a second retaining groove for holding the second conductive member.

[0145] With this configuration, each conductive member moves along each retaining groove and makes contact with the conductive part, thereby forming a circuit. As a result, the power supply to the light source can be switched more stably.

[0146] (Note 10) The light source device according to Appendix 9, wherein the first retaining groove and the second retaining groove are arranged linearly in the radial direction of the retaining member.

[0147] With this configuration, since each retaining groove is formed linearly along the radial direction, when the transmitted optical element is not rotating, either the first conductive member or the second conductive member can be separated from the conductive part by gravity. This makes it easier to switch between the first and second states.

[0148] (Note 11) The movable part further comprises a third conductive member, The light source device according to Appendix 9 or Appendix 10, wherein the groove portion further has a third retaining groove for holding the third conductive member.

[0149] With this configuration, contact with the conductive part can be severed regardless of the position in which the groove is stopped relative to the ground. Therefore, the power supply to the light source can be more reliably stopped when the rotation of the transmitted optical element weakens, and when the transmitted optical element is not rotating, the light emitted from the light source continues to incident on the subsequent optical components, thereby preventing the optical components from being exposed to high temperatures.

[0150] (Note 12) The light source device according to Appendix 11, wherein the first retaining groove, the second retaining groove, and the third retaining groove are provided on the retaining member so as to be arranged at equal intervals in the circumferential direction with respect to the rotation axis.

[0151] With this configuration, contact with the conductive part can be more reliably severed regardless of the position in which the groove is stopped relative to the ground. Therefore, the power supply to the light source can be more reliably stopped when the rotation of the transmitted optical element weakens, and the light emitted from the light source continues to incident on the subsequent optical components when the transmitted optical element is not rotating, thereby further suppressing exposure of the optical components to high temperatures.

[0152] (Note 13) A light source device described in any one of the appendices 1 through 12, A light modulation device that modulates the scanning light emitted from the aforementioned optical scanning unit according to image information, The system comprises a projection optical device that projects image light emitted from the aforementioned optical modulation device, projector.

[0153] This projector configuration, equipped with the aforementioned light source device, provides a highly reliable projector that suppresses malfunctions such as deterioration and damage caused by exposure of each color optical component to high temperatures. [Explanation of Symbols]

[0154] 6…First optical scanning unit, 7, 107, 207…Second optical scanning unit, 8…Third optical scanning unit, 10…Light source device, 11…First light source unit, 12, 32, 212…Second light source unit, 13…Third light source unit, 15…First transmitted optical element (transmitted optical element), 16…Second transmitted optical element (transmitted optical element), 17…Third transmitted optical element (transmitted optical element), 20…Projector, 23…Projection optical device, 43B…Blue light optical modulator (optical modulator), 43G…Green light optical modulator (optical modulator), 43R…Red light optical Modulation device (optical modulation device), 50...drive unit, 52...shaft unit, 54,254...power supply unit, 60,260...conductive unit, 70,270...movable unit, 71,271...first conductive member, 72,272...second conductive member, 75,275...holding member, 77,277...groove unit, 78,278...first holding groove, 79,279...second holding groove, 92...magnet (biasing member), 273...third conductive member, 280...third holding groove, C1...first rotating shaft (rotating shaft), C2...second rotating shaft (rotating shaft), C3...third rotating shaft (rotating shaft).

Claims

1. A light source that emits light, A light scanning unit that periodically scans the light emitted from the light source unit, A movable part that is linked to the optical scanning unit, A power supply unit that supplies power to the light source unit, Equipped with, The optical scanning unit has a transmissive optical element that rotates about a rotation axis extending in a direction intersecting the direction of incidence of the light, and scans the light incident from the light source unit. The movable part has conductivity, The movable part moves in conjunction with the rotation of the transmissive optical element, When the transmitted optical element is rotating, a first state is formed in which the light source unit and the power supply unit are electrically connected and a circuit is configured to supply power to the light source unit, A light source device that switches between a second state in which the electrical connection between the light source unit and the power supply unit is disconnected and power is not supplied to the light source unit when the transmitted optical element is not rotating.

2. The system further includes a conductive portion that allows the light source unit and the power supply unit to be electrically connected via the movable portion, In the first state, the movable part constitutes a circuit that supplies power to the light source by contacting the conductive part, and in the second state, it disconnects the circuit by moving away from the conductive part. The light source device according to claim 1.

3. A shaft portion is connected to a drive unit that rotates the transmitted optical element of the optical scanning unit, and extends along the rotation axis, The system further comprises a holding member connected to the outer circumference of the shaft portion and holding the movable portion, The holding member has a groove that movably holds the movable part along the radial direction perpendicular to the rotation axis. The light source device according to claim 1.

4. The movable part has a cylindrical conductive member. The light source device according to claim 1.

5. The movable part switches between the first state and the second state by the centrifugal force generated by the rotation of the transmitted optical element. The light source device according to claim 1.

6. The movable part switches from the first state to the second state when the centrifugal force falls below the gravity. The light source device according to claim 5.

7. The movable part is further provided with a biasing member that biases it toward the rotation axis, The biasing member generates an attractive force that pulls the movable part, The movable part switches from the first state to the second state when the centrifugal force falls below the attractive force. The light source device according to claim 5.

8. The biasing member is a magnet, The magnet generates a magnetic force as the attractive force, The movable part switches from the first state to the second state when the centrifugal force falls below the magnetic force. The light source device according to claim 7.

9. The movable part has a first conductive member and a second conductive member, The groove portion has a first retaining groove for holding the first conductive member and a second retaining groove for holding the second conductive member. The light source device according to claim 3.

10. The first retaining groove and the second retaining groove are arranged linearly in the radial direction of the retaining member. The light source device according to claim 9.

11. The movable part further comprises a third conductive member, The groove portion further has a third retaining groove for holding the third conductive member. The light source device according to claim 9.

12. In the circumferential direction with respect to the rotation axis, the first retaining groove, the second retaining groove, and the third retaining groove are provided on the retaining member so as to be arranged at equal intervals. The light source device according to claim 11.

13. A light source device according to any one of claims 1 to 12, A light modulation device that modulates the scanning light emitted from the aforementioned optical scanning unit according to image information, The system comprises a projection optical device that projects image light emitted from the aforementioned optical modulation device, projector.

Images