Light source device and projector

Abstract

To provide a light source device and a projector capable of suppressing failure of an optical member in a subsequent stage.SOLUTION: A light source device according to an aspect of the invention includes a light source section adapted to emit light, a light scanning section adapted to scan the light entering the light source section, and a movable section adapted to move in conjunction with the light scanning section, wherein the light scanning section has a transmissive optical element including a plane of incidence which the light emitted from the light source section enters, and an exit surface which is parallel to the plane of incidence, and through which the light having entered through the plane of incidence is emitted, and the transmissive optical element rotates around a rotational axis to thereby scan an illumination target area with the light entering from the light source section, the movable part does not overlap the optical path of the light emitted from the light source part when the transmission optical element rotates, and overlaps the optical path of the light emitted from the light source part when the transmission optical element does not rotate.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Conventionally, there is a projector that illuminates a light modulation device such as a liquid crystal panel by scanning light emitted from a light-emitting element over time on the light modulation device. Patent Document 1 listed below discloses a projector that includes a light source device including a light source lamp, a liquid crystal light valve, a polygon mirror provided between the light source device and the liquid crystal light valve, and a projection lens. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-225956 Summary of the Invention [Problem to be solved by the invention]

[0004] In the projector of Patent Document 1, if the rotation of the polygon mirror stops for some reason, light continues to be locally irradiated onto the downstream optical components, which could cause problems such as deformation or damage to the optical components due to heat. [Means for solving the problem]

[0005] In order to solve the above problems, according to a first aspect of the present invention, there is provided a light source device comprising: a light source unit that emits light; a light scanning unit that scans the light incident from the light source unit; and a movable unit that moves in conjunction with the light scanning unit, wherein the light scanning unit has a transmissive optical element including an incident surface into which the light emitted from the light source unit is incident and an exit surface that is parallel to the incident surface and exits the light incident from the incident surface, wherein the transmissive optical element rotates around a rotation axis to scan the light incident from the light source on an illuminated surface, and wherein the movable unit does not overlap with the optical path of the light emitted from the light source unit when the transmissive optical element rotates, and overlaps with the optical path of the light emitted from the light source unit when the transmissive optical element does not rotate.

[0006] According to a second aspect of the present invention, there is provided a projector comprising the light source device of the first aspect, an optical modulation device that modulates the light emitted from the light source device based on image information, and a projection optical device that projects the light emitted from the optical modulation device. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a plan view showing a schematic configuration of a projector according to a first embodiment. [Figure 2] FIG. 2 is a plan view of the optical scanning unit as viewed from a direction along the illumination optical axis. [Figure 3] 10A and 10B are diagrams illustrating a state of the light blocking member when the transmissive optical element does not rotate. [Figure 4A] 10A and 10B are schematic diagrams illustrating the behavior of white light when a transmissive optical element rotates. [Figure 4B] 10A and 10B are schematic diagrams illustrating the behavior of white light when a transmissive optical element rotates. [Figure 4C] 10A and 10B are schematic diagrams illustrating the behavior of white light when a transmissive optical element rotates. [Figure 4D] 10A and 10B are schematic diagrams illustrating the behavior of white light when a transmissive optical element rotates. [Figure 4E] 10A and 10B are schematic diagrams illustrating the behavior of white light when a transmissive optical element rotates. [Figure 4F]10A and 10B are schematic diagrams illustrating the behavior of white light when a transmissive optical element rotates. [Figure 5] FIG. 10 is a plan view of the optical scanning unit of the first modified example, viewed from a direction along the illumination optical axis. [Figure 6] FIG. 10 is a plan view of the optical scanning unit of the second modified example, viewed from the direction along the illumination optical axis. [Figure 7] FIG. 11 is a side cross-sectional view of the optical scanning unit of the third modified example, as viewed from the direction along the rotation axis. [Figure 8] FIG. 10 is a perspective view showing the main configuration of a movable portion of a second embodiment. [Figure 9] FIG. 10 is a plan view showing a schematic configuration of a projector according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] (First embodiment) A first embodiment of the present invention will be described below with reference to the drawings. The projector of this embodiment is an example of a liquid crystal projector that uses a liquid crystal panel as a light modulation device. In the drawings below, the dimensions of some components may be shown on different scales to make them easier to see.

[0009] FIG. 1 is a plan view showing a schematic configuration of a projector according to this embodiment. 1, a projector 100 of this embodiment includes a light source device 1, a light modulation device 2, an exit-side polarizing plate 3, and a projection optical device 4. The light source device 1 includes a light source unit 10, a light scanning unit 12, and a movable unit 30.

[0010] The following description will be given using an XYZ Cartesian coordinate system in the drawings as necessary. The X axis is an axis parallel to the illumination optical axis AX of the light source device 1. The illumination optical axis AX of the light source device 1 is defined as an axis along the chief ray of the light emitted from the light source unit 10. The Y axis is an axis perpendicular to the X axis and is an axis along the rotation axis O of the transmissive optical element 13 of the optical scanning unit 12. The Z axis is an axis perpendicular to the X axis and Y axis.

[0011] The light source unit 10 is disposed on the -X side of the optical scanning unit 12. The light source unit 10 emits white light L as illumination light. The light source unit 10 includes a plurality of light-emitting elements 10a each made of a laser diode. The plurality of light-emitting elements 10a are arranged in a row along the Y-axis direction at predetermined intervals. The light source unit 10 of this embodiment emits white light L including light rays from each of the light-emitting elements 10a aligned in the Y-axis direction. Therefore, the cross-sectional shape perpendicular to the principal ray of the white light L emitted by the light source unit 10 is a strip shape having a major axis extending along the Y-axis direction.

[0012] The optical scanning unit 12 is provided on the illumination optical axis AX between the light source unit 10 and the light modulation device 2. The optical scanning unit 12 scans the illuminated area with white light L incident from the light source unit 10. Specifically, the optical scanning unit 12 scans the strip-shaped white light L extending in the Y-axis direction in the Z-axis direction in the light modulation area 2c of the light modulation device 2 arranged in the illuminated area. In this way, by scanning the white light L in one axial direction, it is possible to illuminate the entire rectangular light modulation area 2c with the white light L.

[0013] The movable part 30 is connected to the optical scanning part 12 and moves in conjunction with the optical scanning part 12. The configuration of the movable part 30 will be described later.

[0014] The light modulation device 2 is provided on the light emission side of the light source device 1 on the illumination optical axis AX. The light modulation device 2 modulates the white light L emitted from the light source device 1 in accordance with image information to form image light. A transmissive liquid crystal panel is used for the light modulation device 2. The liquid crystal panel may or may not include a color filter. If the liquid crystal panel includes a color filter, a projector 100 capable of color display can be realized. If the liquid crystal panel does not include a color filter, a projector 100 capable of monochrome display can be realized. The liquid crystal panel can be driven by any method, including twisted nematic (TN), vertical alignment (VA), and in-plane switching (IPS) methods, without any particular limitation.

[0015] The exit-side polarizing plate 3 is provided on the illumination optical axis AX between the light modulation device 2 and the projection optical device 4. The exit-side polarizing plate 3 transmits linearly polarized light in a specific direction that is emitted from the light modulation device 2 toward the projection optical device 4. In the case of this embodiment, a laser diode is used for each light-emitting element 10a of the light source section 10, and therefore linearly polarized light is emitted from the light source device 1. Therefore, the entrance-side polarizing plate that is provided on the light entrance side of the light modulation device 2 can be omitted.

[0016] The projection optical device 4 is composed of multiple projection lenses. The projection optical device 4 enlarges and projects the image light modulated by the light modulation device 2 onto a projection surface such as a screen, thereby displaying an image on the projection surface.

[0017] The optical scanning unit 12 includes a transmission optical element 13 and a rotation driving device 14 . The transmitting optical element 13 is composed of a rotatably supported light-transmitting member. The transmitting optical element 13 is rotatable about a rotation axis O extending along the Y-axis direction. The transmitting optical element 13 is connected to a rotation drive device 14 formed of a motor or the like. The transmitting optical element 13 rotates about the rotation axis O by being driven by the rotation drive device 14.

[0018] The transmissive optical element 13 is made of a transmissive material such as optical glass (e.g., BK7), quartz, or resin. The transmissive optical element 13 has a cylindrical shape extending along the rotation axis O. The transmissive optical element 13 of this embodiment has a first surface 13a and a second surface 13b that intersect with the rotation axis O, and four side surfaces 13c that are perpendicular to the first surface 13a and the second surface 13b. That is, the shape of the transmissive optical element 13 is a regular rectangular prism having six flat surfaces including the first surface 13a, the second surface 13b, and the four side surfaces 13c. The cross section of the transmissive optical element 13 cut along a plane perpendicular to the rotation axis O is a square. That is, the four side surfaces 13c have the same area, and two opposing side surfaces are parallel to each other. The rotation axis O coincides with the center of the square-shaped transmissive optical element 13.

[0019] The transmissive optical element 13 transmits the white light L emitted from the light source unit 10 while rotating around the rotation axis O. Therefore, the side surface onto which the white light L emitted from the light source unit 10 enters the transmissive optical element 13 is not fixed, but changes over time. Similarly, the side surface onto which the white light L incident on the transmissive optical element 13 is emitted into external space is not fixed, but changes over time. In the transmissive optical element 13, the side surface onto which the white light L emitted from the light source unit 10 enters is referred to as the "incident surface." The side surface from which the white light L incident from the incident surface exits is referred to as the "exit surface." In this case, the incident surface and the exit surface change over time and are either two of the four side surfaces 13c that are parallel to each other.

[0020] In this specification, when two surfaces of the transmissive optical element 13 are said to be parallel to each other, the angle between the two surfaces is said to be in the range of 0±5 degrees, taking into consideration the processing accuracy of the glass material that makes up the translucent member, the allowable range of parallelism of light, etc.

[0021] In this embodiment, the transmissive optical element 13 has four side surfaces 13c, but the number of side surfaces does not necessarily have to be four, and is preferably 2×m (m: a natural number greater than or equal to 2). That is, the number of side surfaces is preferably an even number, for example, 6, 8, or the like. If the number of side surfaces is an even number, each of the side surfaces is parallel to the side surface opposite it, and there are no non-parallel side surfaces. This reduces the generation of stray light in the transmissive optical element 13, and improves light utilization efficiency.

[0022] The transmissive optical element 13 may be made of quartz. In the transmissive optical element 13, as the amount of light transmitted through the translucent member increases, the amount of light absorbed by the translucent member also increases, potentially causing thermal distortion in the translucent member. In this case, the polarization direction of the white light L emitted from the light source unit 10 is disturbed, and linearly polarized light incident on the translucent member becomes elliptically polarized light before being emitted from the translucent member. As a result, the projector 100 loses the effect of achieving a predetermined contrast without an incident-side polarizing plate by using laser diodes for each light-emitting element 10a of the light source unit 10. In other words, even if the light source unit 10 uses laser diodes, an incident-side polarizing plate is required to align the polarization direction. Therefore, to achieve the above effect, it is desirable to use a glass material with a small Young's modulus and thermal expansion coefficient as a glass material with low thermal distortion, and quartz is a desirable example.

[0023] Next, the movable unit 30 will be described. The movable unit 30 does not overlap with the optical path of the white light L emitted from the light source unit 10 when the transmitting optical element 13 rotates, and overlaps with the optical path of the white light L emitted from the light source unit 10 when the transmitting optical element 13 does not rotate. In this specification, "not overlapping with the optical path of the white light L when the transmitting optical element 13 rotates" does not mean that the optical path does not overlap at all times during rotation of the transmitting optical element 13, but means that the movable unit 30 does not overlap with the optical path of the white light L when the transmitting optical element 13 rotates at a predetermined rotation speed or higher. The movable unit 30 moves in response to centrifugal force caused by the rotation of the transmitting optical element 13, as described below, and does not overlap with the optical path of the white light L when the centrifugal force exceeds a predetermined threshold due to rotation at a predetermined rotation speed or higher. In other words, the movable unit 30 overlaps with the optical path of the white light L when the centrifugal force falls below a predetermined threshold.

[0024] The movable unit 30 has a connecting portion 31 connected to the light scanning unit 12, and a light blocking member 32 rotatably attached to the connecting portion 31. In the movable unit 30 of this embodiment, the connecting portion 31 is connected to the transmissive optical element 13 of the light scanning unit 12. The connecting portions 31 are provided at each of the four corners of the square-shaped transmissive optical element 13. The movable unit 30 of this embodiment has a plurality of connecting portions 31 and light blocking members 32. The plurality of connecting portions 31 include a first connecting portion 31a, a second connecting portion 31b, a third connecting portion 31c, and a fourth connecting portion 31d.

[0025] 1, an imaginary line K1 is set connecting an apex 13d1 where the first side surface 13c1 and the second side surface 13c2 intersect with the rotation axis O, an imaginary line K2 is set connecting an apex 13d2 where the second side surface 13c2 and the third side surface 13c3 intersect with the rotation axis O, an imaginary line K3 is set connecting an apex 13d3 where the third side surface 13c3 and the fourth side surface 13c4 intersect with the rotation axis O, and an imaginary line K4 is set connecting an apex 13d4 where the fourth side surface 13c4 and the first side surface 13c1 intersect with the rotation axis O.

[0026] The connector 31 is disposed at a position that does not overlap with the optical path of the white light L emitted from the light source unit 10. In the present embodiment, when viewed in a plan view in the Y-axis direction along the rotation axis O of the transmissive optical element 13, the connectors 31a to 31d are disposed on the imaginary lines K1 to K4, respectively. Specifically, the first connector 31a is disposed on the imaginary line K1, the second connector 31b is disposed on the imaginary line K2, the third connector 31c is disposed on the imaginary line K3, and the fourth connector 31d is disposed on the imaginary line K4.

[0027] The multiple light blocking members 32 include a first light blocking member 32a, a second light blocking member 32b, a third light blocking member 32c, and a fourth light blocking member 32d. When cut along a plane perpendicular to the rotation axis O, each of the light blocking members 32a to 32d has a thin plate-like cross section. One end of the first light blocking member 32a is rotatably supported by the first connecting portion 31a, one end of the second light blocking member 32b is rotatably supported by the second connecting portion 31b, one end of the third light blocking member 32c is rotatably supported by the third connecting portion 31c, and one end of the fourth light blocking member 32d is rotatably supported by the fourth connecting portion 31d.

[0028] Fig. 2 is a plan view of the light scanning unit 12 as viewed from the direction along the illumination optical axis AX. Fig. 2 illustrates a state in which any side surface 13c of the transmissive optical element 13 is perpendicular to the illumination optical axis AX. 2, the connecting portions 31 are provided on both ends of the top 13d of the transmissive optical element 13 in the Y-axis direction along the rotation axis O. Specifically, the connecting portions 31 include a first connecting portion 311 connected to one side (+Y side) in the Y-axis direction and a second connecting portion 312 connected to the other side (-Y side) in the Y-axis direction. The rotation drive device 14 includes a rotating portion 14a connected to the first surface 13a of the transmissive optical element 13, and a driving portion 14b that rotates the rotating portion 14a around the rotation axis O. The rotation axis of the light blocking member 32 in the connecting portion 31 is an axis parallel to the rotation axis O of the transmissive optical element 13.

[0029] In this way, in the movable section 30, the plurality of light blocking members 32 are connected at both ends in the long side direction to the transmissive optical element 13 via the connecting sections 31, so that the plurality of light blocking members 32 are connected in a stable state to the rotating transmissive optical element 13. Therefore, each light blocking member 32 can achieve a smooth rotational movement in a stable state relative to the rotating transmissive optical element 13.

[0030] When the transmissive optical element 13 rotates, centrifugal force causes the light-shielding members 32 to rotate in a direction such that the end opposite the end connected to the connecting portion 31 moves away from the side surface 13c of the transmissive optical element 13. The centrifugal force acting on each light-shielding member 32 increases in proportion to the rotational speed of the transmissive optical element 13. When the transmissive optical element 13 rotates at a predetermined rotation speed or more and the centrifugal force exceeds a predetermined threshold, each light-shielding member 32 no longer overlaps with the illumination optical axis AX, and eventually, as shown in FIG. 1 , each light-shielding member 32a to 32d opens in the direction along the imaginary lines K1 to K4. When the transmissive optical element 13 rotates in this manner, the multiple light-shielding members 32 do not cover the side surface 13c of the transmissive optical element 13 in the direction along the illumination optical axis AX, and do not block the white light L incident on the transmissive optical element 13.

[0031] Here, when the white light L emitted from the light source unit 10 is incident on each of the vertices 13d1 to 13d4 of the transmissive optical element 13, the white light L straddles each of the vertices 13d1 to 13d4 and is incident on two side surfaces 13c. If the white light L is incident on both side surfaces 13c simultaneously in this manner, the white light L transmitted through the transmissive optical element 13 is split into two and simultaneously enters both ends of the light modulation region 2c of the light modulation device 2, making it impossible to generate desired image light. For this reason, it is preferable not to allow the white light L to be incident on each of the vertices 13d1 to 13d4 of the transmissive optical element 13 around the time when each of the vertices 13d1 to 13d4 of the transmissive optical element 13 overlaps with the illumination optical axis AX.

[0032] In the light source device 1 of this embodiment, the output of the light source unit 10 is turned off in accordance with the timing before and after each of the apexes 13d1 to 13d4 of the transmissive optical element 13 is positioned on the illumination optical axis AX. With this configuration, the output of the light source unit 10 is turned off at the timing when each of the apexes 13d1 to 13d4 of the transmissive optical element 13 is positioned on the illumination optical axis AX, so the white light L is not blocked by each of the connecting portions 31a to 31d provided on each of the apexes 13d1 to 13d4. Therefore, the white light L emitted from the light source unit 10 can be used efficiently.

[0033] On the other hand, when the transmissive optical element 13 is not rotating, centrifugal force does not act on each light blocking member 32. For example, when the rotation of the rotating transmissive optical element 13 is stopped, the rotation speed of the transmissive optical element 13 gradually decreases. At this time, each light blocking member 32 rotates in a direction such that the end opposite to the side connected to the connecting portion 31 approaches the vertical direction, and when the centrifugal force eventually falls below a predetermined threshold, some of the light blocking members 32 approach the transmissive optical element 13 and overlap with the illumination optical axis AX.

[0034] FIG. 3 is a diagram showing the state of each light blocking member 32 when the transmissive optical element 13 does not rotate. 3, when the transmissive optical element 13 does not rotate, each light-shielding member 32 is disposed along the +Z side, which is the vertical direction, due to its own weight. As a result, in the direction along the illumination optical axis AX, the light-shielding member 32 is disposed between the light source unit 10 and the side surface 13c forming the incident surface onto which the white light L emitted from the light source unit 10 is incident. In other words, the light-shielding member 32 overlaps with the optical path of the white light L emitted from the light source unit 10.

[0035] 3, the light blocking member 32 is in contact with the side surface 13c that forms the incident surface, but the positional relationship between the light blocking member 32 and the side surface 13c changes depending on the positional relationship between the position where the rotation of the transmitting optical element 13 stops and the rotation axis O. In any case, when the transmitting optical element 13 does not rotate, the light blocking member 32 is disposed between the light source unit 10 and the side surface 13c of the transmitting optical element 13 so as to overlap with the optical path of the white light L.

[0036] The behavior of the white light L when it passes through the transmission optical element 13 will be described below. 4A to 4F are schematic diagrams for explaining the behavior of the white light L when the transmissive optical element 13 rotates. In this example, when viewed from the +Y side, the transmissive optical element 13 rotates clockwise around the rotation axis O, and the state shown is one in which time has passed from FIG. 4A to FIG. 4F. The rotation drive device 14 is not shown in FIGS. 4A to 4F.

[0037] 4A to 4F, the angle formed between the illumination optical axis AX and a straight line M that passes through the rotation axis O and is perpendicular to the side surface 13c1 of the transmitting optical element 13 is defined as the rotation angle ω of the transmitting optical element 13. In reality, the white light L has a predetermined luminous flux width in the Z-axis direction, but here we will focus on the behavior of the light ray L1a, which is the chief ray traveling on the illumination optical axis AX.

[0038] 4A shows the initial state of the transmissive optical element 13. That is, the transmissive optical element 13 is not rotated, the straight line M and the illumination optical axis AX overlap, and the rotation angle ω is 0 degrees. In this case, the light ray L1a is incident perpendicularly on the side surface 13c1, and therefore travels along the illumination optical axis AX inside the transmissive optical element 13 without being refracted at the side surface 13c1. Next, the light ray L1a is also incident perpendicularly on the side surface 13c3 that is parallel to the side surface 13c1. Therefore, the light ray L1a is emitted from the transmissive optical element 13 without being refracted at the side surface 13c3 either, and travels along the illumination optical axis AX.

[0039] Next, as shown in FIG. 4B , when the transmissive optical element 13 rotates by a rotation angle ω, the light ray L1a is incident on the side surface 13c1 at an incident angle equal to the rotation angle ω. Therefore, the light ray L1a is refracted in the direction shown in the figure (toward the +Z side) and travels inside the transmissive optical element 13. Next, the light ray L1a is incident on the side surface 13c3 at a predetermined incident angle, so it is refracted at the side surface 13c3 and is emitted from the transmissive optical element 13. At this time, because the side surfaces 13c1 and 13c3 are parallel to each other, the incident angle of the light ray L1a with respect to the side surface 13c1 and the incident angle of the light ray L1a with respect to the side surface 13c3 are equal, and the refraction angle of the light ray L1a incident on the side surface 13c1 and the refraction angle of the light ray L1a emitted from the side surface 13c3 have opposite signs but equal absolute values. This cancels out the refraction angle of light ray L1a when it enters side surface 13c1 and the refraction angle when it emerges from side surface 13c3. As a result, light ray L1a travels parallel to the illumination optical axis AX at a position displaced by a displacement amount d from the illumination optical axis AX toward the +Z side.

[0040] Next, as shown in Figure 4C, when the rotation angle ω of the transmissive optical element 13 becomes larger than that of Figure 4B, the angle of incidence of the light ray L1a becomes larger, and the angle of refraction also becomes larger. Therefore, the displacement d of the light ray L1a from the illumination optical axis AX becomes larger than that of Figure 4B. Furthermore, the state in which the light ray L1a travels parallel to the illumination optical axis AX is always maintained. When the rotation angle ω is between 0 degrees and 45 degrees, the displacement d increases monotonically as the rotation angle ω increases.

[0041] Next, as shown in FIG. 4D, when the rotation angle ω of the transmissive optical element 13 exceeds 45 degrees, the incident surface of the light ray L1a changes from the side surface 13c1 to the side surface 13c2. At this time, the light ray L1a is refracted at the side surface 13c2, but the refraction direction is different from that in the period up to FIG. 4C, and the light ray L1a is refracted in the direction shown in the figure (toward the -Z side). The exit surface of the light ray L1a also changes from the side surface 13c3 to the side surface 13c4. However, because the side surfaces 13c2 and 13c4 are parallel to each other, the refraction angle of the light ray L1a when it enters the side surface 13c3 and the refraction angle when it exits the side surface 13c4 cancel each other out, as in the period up to FIG. 4C. As a result, the light ray L1a travels parallel to the illumination optical axis AX at a position displaced by a displacement amount d toward the -Z side from the illumination optical axis AX.

[0042] Next, as shown in Fig. 4E, when the rotation angle ω of the transmissive optical element 13 becomes larger than that of Fig. 4D, the angle of incidence of the light ray L1a becomes smaller, and the angle of refraction also becomes smaller. Therefore, the displacement d of the light ray L1a from the illumination optical axis AX becomes smaller than that in Fig. 4D. In this way, when the rotation angle ω is between 45 degrees and 90 degrees, the displacement d monotonically decreases as the rotation angle ω increases.

[0043] Next, as shown in FIG. 4F, when the rotation angle ω of the transmissive optical element 13 reaches 90 degrees, the incident surface changes from the side surface 13c1 in the initial state to the side surface 13c2, but the behavior of the light ray L1a becomes the same as in the initial state shown in FIG. 4A.

[0044] As described above, if the incident and exit surfaces of the transmitting optical element 13 are parallel to each other, the traveling direction of the light ray L1a does not change regardless of the rotation angle ω of the transmitting optical element 13. Instead, the light ray L1a translates in a direction parallel to the illumination optical axis AX over time. When the rotation angle ω is 0°, the displacement d of the light ray L1a is 0. As the rotation angle ω ranges from 0° to 45°, the displacement d increases toward either the +Z or −Z side. As soon as the rotation angle ω exceeds 45°, the displacement direction reverses while the absolute value of the displacement d remains the same. As the rotation angle ω ranges from 45° to 90°, the displacement d decreases. When the rotation angle ω reaches 90°, the displacement d becomes 0. After 90°, the above behavior is repeated. Therefore, as the transmitting optical element 13 rotates once, the displacement d of the light ray L1a repeats the above cycle four times. The amount of displacement of the light ray L1a can be set appropriately by adjusting the parameters of the transmitting optical element 13, such as the refractive index and size.

[0045] As described above, the light source device 1 of this embodiment includes a light source unit 10 that emits white light L, an optical scanning unit 12 that scans the white light L incident from the light source unit 10, and a movable unit 30 that moves in conjunction with the optical scanning unit 12. The optical scanning unit 12 has a transmissive optical element 13 that includes an incident surface onto which the white light L emitted from the light source unit 10 is incident and an exit surface that is parallel to the incident surface and from which the white light L incident from the incident surface exits. The transmissive optical element 13 scans the illuminated area with the white light L incident from the light source unit 10 by rotating around a rotation axis O. The movable unit 30 does not overlap with the optical path of the white light L emitted from the light source unit 10 when the transmissive optical element 13 rotates, and overlaps with the optical path of the white light L emitted from the light source unit 10 when the transmissive optical element 13 does not rotate. Note that "not overlapping with the optical path" also includes momentary overlap between the white light L and the movable unit 30 within a range that does not affect image formation.

[0046] According to the light source device 1 of this embodiment, when the transmissive optical element 13 does not rotate, the optical path of the white light L emitted from the light source unit 10 can be blocked. Therefore, when the rotation of the transmissive optical element 13 in the optical scanning unit 12 stops, it is possible to prevent the white light L from continuing to be irradiated onto optical components arranged in a subsequent stage, which can cause problems such as deformation or damage due to heat in the optical components. Furthermore, since the movable unit 3 can move in conjunction with the rotation of the transmissive optical element 13 of the optical scanning unit 12 without performing special electrical control or the like, the reliability of the interlock can be improved.

[0047] According to the projector 100 of this embodiment, when the transmissive optical element 13 is not rotating, the white light L from the light source unit 10 is not emitted to the outside, and therefore it is possible to prevent problems such as deformation or breakage due to heat in the light modulation device 2. Therefore, it is possible to provide a projector 100 that is excellent in reliability and durability.

[0048] (First Modification) Next, a first modified example of the first embodiment will be described. The light source device of this modification differs from the first embodiment in the configuration of the optical scanning unit, but the other configurations are the same. Therefore, the same reference numerals are used for the members that are the same as those in the first embodiment, and detailed descriptions thereof will be omitted.

[0049] Fig. 5 is a plan view of the optical scanning unit 12A of this modified example as viewed from the direction along the illumination optical axis AX, showing a state in which any side surface 13c of the transmissive optical element 13 is perpendicular to the illumination optical axis AX. 5, in the optical scanning unit 12A of this modified example, the connecting portion 131 is connected to the rotating portion 14a of the rotary drive device 14. One end of the light blocking member 32 in the long side direction is connected to the rotary drive device 14 via the connecting portion 131. In this modified example, the connecting portion 131 is provided on the rotary drive device 14 side rather than on the transmissive optical element 13, and therefore the connecting portion 131 does not overlap with the side surface 13c of the transmissive optical element 13. Therefore, compared to when the connecting portion is provided on the transmissive optical element 13, the white light L can be made to be incident on the side surface 13c of the transmissive optical element 13 more efficiently.

[0050] In this way, the light source device including the optical scanning unit 12A of this modified example can further improve the light utilization efficiency of the white light L emitted from the light source unit 10. Furthermore, a projector including this light source device can be realized that has excellent light utilization efficiency, reliability, and durability.

[0051] (Second Modification) Next, a second modified example of the first embodiment will be described. The light source device of this modification differs from the first embodiment in the configuration of the optical scanning unit, but the other configurations are the same. Therefore, the same reference numerals are used for the members that are the same as those in the first embodiment, and detailed descriptions thereof will be omitted.

[0052] Fig. 6 is a plan view of the optical scanning unit 12B of this modified example as viewed from the direction along the illumination optical axis AX, showing a state in which any side surface 13c of the transmissive optical element 13 is perpendicular to the illumination optical axis AX. 6, the optical scanning unit 12B has a holding unit 21 that holds the transmissive optical element 13, a housing 22 that rotatably supports the holding unit 21, the transmissive optical element 13, and a connecting unit 31. The holding unit 21 and the housing 22 are made of a metal material that is lightweight and has excellent rigidity.

[0053] The holder 21 has a first frame 21a that is connected to the rotating unit 14a of the rotation drive device 14 and that has a first connecting portion 311 of the connecting portion 31 provided therein, a second frame 21b that is arranged on the opposite side of the first frame 21a in the Y-axis direction along the rotation axis O and that has a second connecting portion 312 of the connecting portion 31 provided therein, and a shaft 21c that protrudes from the second frame 21b along the rotation axis O and is rotatably supported by the housing 22. The shaft 21c is arranged coaxially with the rotation axis O. The shaft 21c is rotatably supported by, for example, a bearing member B provided in the housing 22. The housing 22 may further hold the rotation drive device 14 and may be formed, for example, as part of a frame that forms the exterior of the light source device 1.

[0054] The first frame 21a and the second frame 21b are respectively bonded to the first surface 13a and the second surface 13b of the transmissive optical element 13. The first frame 21a and the second frame 21b may be integrally formed in an area not shown, or may be formed as separate bodies.

[0055] In the optical scanning unit 12B of this modified example, the light-shielding member 32 has both ends in the Y-axis direction along the long side connected to the first frame 21a and the second frame 21b of the holding unit 21, so that the light-shielding member 32 can be stably connected to the rotating transmissive optical element 13.

[0056] In the optical scanning unit 12B of this modified example, one end side (+Y side) of the holding unit 21 is supported by the rotary drive device 14, and the other end side (-Y side) of the holding unit 21 is supported by the housing 22 via a bearing member B. According to the optical scanning unit 12B of this modified example, the transmissive optical element 13 held by the holding unit 21 is supported at both ends in the Y-axis direction along the rotation axis O, so that it is possible to suppress the occurrence of axial wobble when the transmissive optical element 13 rotates. Therefore, when the transmissive optical element 13 rotates or when the light blocking member 32 rotates in conjunction with the rotation of the transmissive optical element 13, it is possible to suppress the occurrence of vibrations and noise due to axial wobble of the transmissive optical element 13.

[0057] Furthermore, according to the optical scanning unit 12B of this modified example, the connecting portion 31 is provided on the holding portion 21 instead of the transmissive optical element 13, and therefore the connecting portion 31 is less likely to block the white light L incident on the transmissive optical element 13 than when the connecting portion is provided directly on the transmissive optical element 13. Therefore, the white light L can be more efficiently incident on the transmissive optical element 13.

[0058] In this way, the light source device including the optical scanning unit 12B of this modified example can further improve the light utilization efficiency of the white light L emitted from the light source unit 10. Furthermore, a projector including this light source device can be realized that is excellent in light utilization efficiency, reliability, and durability, as well as quiet with reduced vibration and noise.

[0059] (Third Modification) Next, a third modified example of the first embodiment will be described. The light source device of this modification differs from that of the first embodiment in the configuration of the movable part of the optical scanning unit, but the other configurations are the same. Therefore, the same reference numerals are used for the members that are the same as those of the first embodiment, and detailed descriptions thereof will be omitted.

[0060] FIG. 7 is a side cross-sectional view of the optical scanning unit 12C of this modified example, as viewed from the direction along the rotation axis O. 7, a movable part 30C in an optical scanning part 12C of this modified example has a connecting part 31, a light blocking member 32, and a centrifugal force adjusting member 40. The centrifugal force adjusting member 40 is a member that adjusts the magnitude of the centrifugal force acting on the light blocking member 32.

[0061] In this modified example, the centrifugal force adjustment member 40 is a weight provided on the light blocking member 32. The centrifugal force adjustment member 40 can adjust the centrifugal force acting on the light blocking member 32 depending on the installation position on the light blocking member 32 or the weight of the weight.

[0062] According to the optical scanning unit 12C of this modified example, the centrifugal force acting on the light blocking member 32 can be adjusted to any value by the centrifugal force adjusting member 40 without changing the rotation speed of the transmissive optical element 13.

[0063] (Second embodiment) Next, a second embodiment of the present invention will be described. The light source device of this embodiment differs from that of the first embodiment in the configuration of the movable part, but the other configurations are the same. Therefore, the same reference numerals are used for the members that are the same as those of the first embodiment, and detailed descriptions thereof will be omitted.

[0064] FIG. 8 is a perspective view showing the main configuration of the movable part 130 of this embodiment. As shown in FIG. 8, the movable section 130 of this embodiment includes a connecting section 31, a light blocking member 32, and a rotation suppressing section 33 that suppresses rotation of the light blocking member 32 relative to the connecting section 31. The rotation suppressing portion 33 includes a spring member 34 that applies a biasing force to the light blocking member 32 and a magnet 35 that applies a magnetic force to the light blocking member 32.

[0065] The spring member 34 is formed, for example, by a torsion coil spring. The spring member 34 includes a spring portion 34a formed by a coil spring and a pair of legs 34b provided at both ends of the spring portion 34a and extending in a direction twisted by 90 degrees. Based on this configuration, the spring member 34 receives a torsional load at the central axis of the coil and uses the reaction force to apply a biasing force to the light blocking member 32 to move it toward the side surface 13c of the transmissive optical element 13. The magnet 35 attracts the metal light blocking member 32 by magnetic force. In this way, the rotation suppression unit 33 can efficiently generate a rotation suppression force that suppresses the rotation of the light blocking member 32 by using spring force or magnetic force.

[0066] In the movable section 130 of this embodiment, when the transmissive optical element 13 is not rotating, the rotation suppression section 33 holds the light blocking member 32 in a state where it does not rotate relative to the transmissive optical element 13. Specifically, the rotation suppression section 33 holds the end of the light blocking member 32 opposite the connecting section 31 in a state where it is attracted to the transmissive optical element 13 by the magnet 35, and also holds the light blocking member 32 in a state where it does not rotate relative to the connecting section 31 by the spring force of the spring member 34.

[0067] According to the movable section 330 of this embodiment, when the transmissive optical element 13 is not rotating, the rotation suppression force of the rotation suppression section 33 can hold the light blocking member 32 in a state where it does not rotate relative to the connecting section 31. In the configuration of the first embodiment, even when the transmissive optical element 13 is not rotating, the light blocking member 32 is in a state where it can rotate freely relative to the connecting section 31. Therefore, when the transmissive optical element 13 is not rotating, the light blocking members 32 are arranged side by side on the Z side along the vertical direction due to their own weight, as shown in FIG. 3 , and it is therefore possible to block white light L incident along the X-axis direction that intersects the vertical direction.

[0068] However, for example, in Figure 3, if the projector is installed so that white light L is incident on the transmissive optical element 13 from the Z-axis direction, which is perpendicular to the transmissive optical element 13, it is not possible to block the white light L incident on the transmissive optical element 13.

[0069] In contrast to this, according to the movable section 330 of this embodiment, when the transmissive optical element 13 is not rotating, the rotation suppression section 33 can hold the light blocking member 32 in a state where it does not rotate relative to the connecting section 31. Therefore, even when white light L is incident on the transmissive optical element 13 from the vertical direction, the white light L can be blocked by the light blocking member 32, and the white light L can be suppressed from entering the interior of the transmissive optical element 13.

[0070] Next, a case where the transmissive optical element 13 is rotated in the movable unit 330 of this embodiment will be described. In the movable unit 330 of this embodiment, when the transmissive optical element 13 starts to rotate, centrifugal force corresponding to the rotation speed of the transmissive optical element 13 acts on the light blocking member 32. The rotation suppression unit 33 holds the light blocking member 32 in a state where it does not rotate with respect to the connecting unit 31 while the centrifugal force is below a predetermined threshold. In other words, the light blocking member 32 overlaps with the optical path of the white light L emitted from the light source unit 10.

[0071] On the other hand, when the transmissive optical element 13 rotates at a predetermined rotation speed or more and the centrifugal force exceeds a predetermined threshold, the centrifugal force exceeds the spring force or magnetic force of the rotation suppression unit 33 that suppresses the rotation of the light-blocking member 32. At this time, the end of the light-blocking member 32 opposite the connecting unit 31 rotates in a direction away from the rotation axis O of the transmissive optical element 13, and as shown in FIG. 1 , the end does not overlap with the illumination optical axis AX. As a result, the light-blocking member 32 is not positioned between the light source unit 10 and the side surface 13c that forms the incident surface onto which the white light L emitted from the light source unit 10 is incident, in the direction along the illumination optical axis AX. In other words, the light-blocking member 32 does not overlap with the optical path of the white light L emitted from the light source unit 10.

[0072] Next, a case where the rotation of the transmissive optical element 13 is stopped in the movable part 330 of this embodiment will be described. When the rotation of the transmissive optical element 13 is stopped, the rotation speed of the transmissive optical element 13 decreases and the centrifugal force acting on the light blocking member 32 decreases. Eventually, when the centrifugal force falls below a predetermined threshold, the spring force or magnetic force in the rotation suppression part 33 that suppresses the rotation of the light blocking member 32 exceeds the centrifugal force.

[0073] At this time, the end of the light blocking member 32 opposite the connecting portion 31 moves in a direction approaching the rotation axis O, which is the center of rotation, due to the spring force and magnetic force of the rotation suppressing portion 33. When the rotation of the transmissive optical element 13 eventually stops, the rotation suppressing portion 33 maintains a state in which the light blocking member 32 does not rotate with respect to the connecting portion 31. In other words, the light blocking member 32 overlaps with the optical path of the white light L emitted from the light source unit 10. In this way, the rotation suppression unit 33 can move the light blocking member 32 in a direction overlapping with the optical path of the white light L emitted from the light source unit 10 when the centrifugal force falls below the threshold value.

[0074] The movable unit 330 of this embodiment includes the rotation suppression unit 33, and therefore, even when the incident direction of the white light L on the transmissive optical element 13 is vertical, for example, centrifugal force generated in response to the rotation of the transmissive optical element 13 can be used to effectively switch between a state in which the light blocking member 32 overlaps with the optical path of the white light L and a state in which the light blocking member 32 does not overlap with the optical path of the white light L. Therefore, a projector including a light source device using the movable unit 330 of this embodiment can position the light blocking member 32 at a position where it overlaps with the optical path of the white light L when the transmissive optical element 13 is not rotating, regardless of the installation state of the projector. Therefore, it is possible to provide a high-value-added projector that is excellent in light utilization efficiency, reliability, and durability, and has a high degree of freedom in installation mode.

[0075] (Third embodiment) Next, a third embodiment of the present invention will be described. The light source device of this embodiment differs from the above-described embodiment and modified examples in that the white light emitted from the light source unit is two-dimensionally scanned on the light modulation region 2c of the light modulation device by the light scanning unit, but the other configurations are the same. Therefore, the same reference numerals are used for the components common to the above-described embodiment, and detailed descriptions thereof will be omitted.

[0076] FIG. 9 is a plan view showing a schematic configuration of the projector of this embodiment. 9, a projector 200 of this embodiment includes a light source device 11, a light modulation device 2, an exit-side polarizing plate 3, and a projection optical device 4. The light source device 11 includes a light source section 101, a light scanning section 120, and a movable section 30.

[0077] The light source section 101 of this embodiment includes one light emitting element 101a made of a laser diode. That is, the white light L emitted by the light source section 101 of this embodiment is different from the strip-like light of the above-described embodiment.

[0078] The optical scanning unit 120 scans the white light L incident from the light source unit 101 two-dimensionally in the Y-axis direction and the Z-axis direction in the light modulation region 2c of the light modulation device 2. By scanning the white light L in the two-axis direction, the entire rectangular light modulation region 2c can be illuminated with the white light L.

[0079] The optical scanning unit 120 has a transmitting optical element 13, a rotary drive device 14, a rear-stage transmitting optical element 15, and a rotary drive device 16. The rear-stage transmitting optical element 15 is made of a rotatably supported light-transmitting member. The rear-stage transmitting optical element 15 is rotatable about a rotation axis O1 extending along the Z-axis direction. The rear-stage transmitting optical element 15 is connected to the rotary drive device 16, which is made up of a motor or the like. The rear-stage transmitting optical element 15 rotates about the rotation axis O1 by being driven by the rotary drive device 16.

[0080] The light-transmitting member constituting the rear-stage transmitting optical element 15 is substantially the same as the light-transmitting member constituting the transmitting optical element 13. As the glass material of the light-transmitting member, for example, optical glass such as BK7, quartz, resin, or other light-transmitting materials are used. In particular, in the case of the rear-stage transmitting optical element 15, unlike the transmitting optical element 13, the white light L incident thereon is lower in optical density than the white light L at the time of incidence on the transmitting optical element 13, because the white light L incident thereon is scanned in one direction by the transmitting optical element 13. Therefore, the rear-stage transmitting optical element 15 is more likely to be able to use a resin material with low light resistance and heat resistance than the transmitting optical element 13.

[0081] The rear-stage transmitting optical element 15 has a third surface 15a and a fourth surface 15b that intersect with the rotation axis O1, and four side surfaces 15c that are in contact with the third surface 15a and the fourth surface 15b perpendicularly. That is, the shape of the rear-stage transmitting optical element 15 is a regular quadrangular prism, similar to the transmitting optical element 13.

[0082] The rear-stage transmitting optical element 15 transmits the white light L emitted from the transmitting optical element 13 while rotating around the rotation axis O1. Therefore, the side surface onto which the white light L emitted from the transmitting optical element 13 enters the rear-stage transmitting optical element 15 is not fixed but changes over time. Similarly, the side surface onto which the white light L incident on the rear-stage transmitting optical element 15 is emitted into external space is not fixed but changes over time. In the rear-stage transmitting optical element 15, the second side surface onto which the white light L emitted from the transmitting optical element 13 enters is referred to as the second incident surface. The second side surface from which the white light L incident from the second incident surface exits is referred to as the second exit surface. In this case, the second incident surface and the second exit surface change over time and are either two of the four side surfaces 15c that are parallel to each other.

[0083] In this embodiment, the rear-stage transmitting optical element 15 has four side surfaces 15c, but the number of side surfaces does not necessarily have to be four, and is preferably 2×n (n: a natural number greater than or equal to 2). That is, the number of side surfaces is preferably an even number, for example, 6, 8, or the like. If the number of side surfaces is an even number, each of the side surfaces is parallel to the side surface opposite to it, and there are no non-parallel side surfaces. This reduces the generation of stray light in the rear-stage transmitting optical element 15, and light utilization efficiency can be improved.

[0084] In this embodiment, the transmitting optical element 13 and the subsequent transmitting optical element 15 both have the shape of a regular rectangular prism, but as long as they have parallel entrance and exit surfaces, the transmitting optical element 13 and the subsequent transmitting optical element 15 may have different shapes.

[0085] According to the optical scanning unit 120 of this embodiment, the white light L emitted from the light source unit 101 is scanned in the Z-axis direction by the transmitting optical element 13, and is scanned in the Y-axis direction perpendicular to the Z-axis direction by the rear-stage transmitting optical element 15. In this way, in the optical scanning unit 120 of this embodiment, the transmitting optical element 13 and the rear-stage transmitting optical element 15 two-dimensionally scan the white light L within the light modulation region 2c of the light modulation device 2.

[0086] According to the light source device 11 of this embodiment, when the optical scanning unit 120 is not driven, that is, when the transmissive optical element 13 and the rear-stage transmissive optical element 15 are not rotating, it is possible to block the optical path of the white light L emitted from the light source unit 101. Therefore, when the rotation of the transmissive optical element 13 in the optical scanning unit 120 stops, it is possible to prevent the white light L from continuing to be irradiated onto the optical components arranged in the rear stage, which can cause problems such as deformation or breakage of the optical components due to heat.

[0087] Although the optical scanning unit 120 of this embodiment has been described as having the movable unit 30 disposed in the transmissive optical element 13, the movable unit 30 may be provided in the subsequent transmissive optical element 15. Alternatively, the movable unit 30 may be provided in each of the transmissive optical element 13 and the subsequent transmissive optical element 15.

[0088] The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the above embodiment and modified examples, the light source unit 10 is turned off in synchronization with the timing at which each of the apexes 13d1 to 13d4 is positioned on the illumination optical axis AX, but the light source unit 10 may remain on, and the white light L may be blocked by each of the connecting units 31a to 31d provided on each of the apexes 13d1 to 13d4 and the light blocking member 32. Also, the configuration of the second embodiment may be combined with the configurations of the first to third modified examples.

[0089] In addition, the specific descriptions of the shape, number, arrangement, materials, etc. of each component of the light source device and the projector are not limited to the above-described embodiment and can be modified as appropriate. Furthermore, in the above-described embodiment, an example was shown in which the light source device according to the present invention is mounted on a projector using a liquid crystal panel, but this is not limiting. The light source device according to the present invention may also be applied to a projector using a digital micromirror device as a light modulation device.

[0090] A summary of this disclosure is provided below. (Appendix 1) a light source unit that emits light; a light scanning unit that scans the light incident from the light source unit; a movable part that moves in conjunction with the optical scanning part; Equipped with the optical scanning unit has a transmissive optical element including an incident surface on which the light emitted from the light source unit is incident, and an exit surface that is parallel to the incident surface and exits the light that has entered from the incident surface, the transmissive optical element rotates around a rotation axis to scan the light incident from the light source unit over an illuminated area; The movable part is When the transmitting optical element rotates, it does not overlap with the optical path of the light emitted from the light source unit, The optical path of the light emitted from the light source unit overlaps with the optical path of the light transmitting optical element when the transmitting optical element is not rotated. Light source device.

[0091] According to the light source device having this configuration, when the transmissive optical element is not rotating, the optical path of the light emitted from the light source unit can be blocked by the movable part. Therefore, when the rotation of the transmissive optical element in the optical scanning unit stops, it is possible to prevent problems such as deformation or damage of the optical components due to heat caused by light continuing to be irradiated onto the optical components arranged downstream. Furthermore, since the movable part can move in conjunction with the rotation of the transmissive optical element of the optical scanning unit without special electrical control, the reliability of the interlock can be improved.

[0092] (Appendix 2) the transmissive optical element has a front surface and a back surface that intersect with the rotation axis, and 2×m (m: a natural number equal to or greater than 2) side surfaces that are in contact with the front surface and the back surface, The incident surface and the exit surface are two of the 2×m side surfaces that are parallel to each other. 10. The light source device of claim 1.

[0093] With this configuration, the number of side surfaces is an even number, and therefore all of the side surfaces facing each other are parallel to each other, eliminating any non-parallel side surfaces. As a result, the generation of stray light in the transmissive optical element is reduced, and light utilization efficiency can be improved.

[0094] (Appendix 3) The movable part is connected to the optical scanning part. 10. The light source device of claim 1.

[0095] According to this configuration, it is possible to realize a configuration in which the movable part is moved in conjunction with the operation of the optical scanning part.

[0096] (Appendix 4) The movable part is a connecting portion connected to the optical scanning portion; a light blocking member rotatably attached to the connecting portion, the light blocking member overlaps with the optical path of the light emitted from the light source unit when the transmissive optical element is not rotated; 4. The light source device according to claim 3.

[0097] According to this configuration, the light emitted from the light source section can be blocked by the light blocking member.

[0098] (Appendix 5) the connecting portion is connected to the transmissive optical element, the connecting portion is disposed at a position not overlapping with an optical path of the light emitted from the light source portion, 5. The light source device according to claim 4.

[0099] According to this configuration, the connecting portion does not block the light emitted from the light source portion, so that the light emitted from the light source portion can be efficiently incident on the transmissive optical element.

[0100] (Appendix 6) the transmissive optical element includes a first side surface and a second side surface onto which the light from the light source unit is incident, When viewed in a plan view in a direction along the rotation axis of the transmissive optical element, the connecting portion of the movable portion is disposed on a virtual line connecting the rotation axis and an apex where the first side surface and the second side surface intersect. 6. The light source device according to claim 4 or 5.

[0101] According to this configuration, when the transmissive optical element rotates, the light blocking member opens in the direction along the imaginary line, so that the light incident on the transmissive optical element is not blocked.

[0102] (Appendix 7) the connecting portion includes a first connecting portion connected to one side of the transmissive optical element in a direction along the rotation axis, and a second connecting portion connected to the other side of the transmissive optical element in a direction along the rotation axis, 5. The light source device according to claim 4.

[0103] With this configuration, both ends of the light blocking member along the rotation axis are connected to the transmissive optical element via the connecting portions, so that the light blocking member is connected in a stable state to the rotating transmissive optical element, and therefore the light blocking member can rotate smoothly and stably relative to the rotating transmissive optical element.

[0104] (Appendix 8) the optical scanning unit includes a holding unit that holds the transmissive optical element and a housing that rotatably supports the holding unit, The holding portion is a first frame connected to a rotation drive device that rotates the transmissive optical element and provided with the first connecting portion; a second frame disposed on the opposite side of the first frame in a direction along the rotation axis and provided with the second connecting portion; a shaft portion that protrudes from the second frame along the rotation axis and is rotatably supported by the housing, 8. The light source device according to claim 7.

[0105] According to this configuration, since both ends of the light blocking member in the direction along the rotation axis are connected to the holder, the light blocking member can be stably connected to the rotating transmissive optical element. Furthermore, since the transmissive optical element held by the holder is axially supported at both ends in the direction along the rotation axis, the occurrence of axial wobble during rotation of the transmissive optical element can be suppressed. Therefore, the occurrence of vibrations and noise due to axial wobble of the transmissive optical element can be suppressed.

[0106] (Appendix 9) the optical scanning unit further includes a rotation drive device that rotates the transmissive optical element, The coupling portion is coupled to the rotation drive device. 5. The light source device according to claim 4.

[0107] According to this configuration, the connecting portion does not overlap with the transmissive optical element, so that light can be made to enter the transmissive optical element efficiently.

[0108] (Appendix 10) the light blocking member is movable in response to centrifugal force caused by rotation of the transmission optical element, the light blocking member overlaps with the optical path of the light emitted from the light source unit when the centrifugal force falls below a predetermined threshold. 9. A light source device according to any one of claims 4 to 8.

[0109] According to this configuration, for example, by stopping the rotation of a rotating transmissive optical element, the rotation speed of the transmissive optical element gradually decreases, and when the centrifugal force falls below a predetermined threshold, the light-shielding member can be superimposed on the optical path of the light.

[0110] (Appendix 11) the movable portion further includes a rotation suppressing portion that suppresses rotation of the light blocking member relative to the connecting portion, the rotation suppression unit moves the light blocking member in a direction overlapping with an optical path of the light emitted from the light source unit when the centrifugal force falls below the threshold value; 11. The light source device of claim 10.

[0111] According to this configuration, by providing a rotation suppression section, it is possible to smoothly switch between a state in which the shading member overlaps with the optical path of the light and a state in which the shading member does not overlap with the optical path of the light, even when, for example, the incident direction of light on the transmissive optical element is along the vertical direction.

[0112] (Appendix 12) the rotation suppressing portion includes at least one of a spring member that applies a biasing force to the light blocking member and a magnet that applies a magnetic force to the light blocking member; 12. The light source device according to claim 11.

[0113] According to this configuration, by utilizing the spring force or magnetic force, it is possible to efficiently generate a rotation suppressing force that suppresses the rotation of the light blocking member.

[0114] (Appendix 13) the movable portion further includes a centrifugal force adjusting member that adjusts the magnitude of the centrifugal force acting on the light blocking member. 13. A light source device according to any one of claims 10 to 12.

[0115] According to this configuration, the centrifugal force acting on the light blocking member can be adjusted to any value by the centrifugal force adjusting member without changing the rotation speed of the transmitting optical element.

[0116] (Appendix 14) a light source device according to any one of Supplementary Note 1 to Supplementary Note 13; a light modulation device that modulates the light incident from the light source device based on image information; a projection optical device that projects the light modulated by the light modulation device, projector.

[0117] With this configuration, when the transmissive optical element is not rotating, light from the light source unit is not emitted to the outside, which prevents the light modulation device from being deformed or damaged by heat, making it possible to provide a projector with excellent reliability and durability. [Explanation of symbols]

[0118] 1, 11...light source device, 2...light modulation device, 3, 30, 30C, 130, 330...movable part, 4...projection optical device, 10, 101...light source part, 12, 12A, 12B, 12C, 120...light scanning part, 13...transmission optical element, 13c...side face, 13d...top part, 14...rotation drive device, 21...holding part, 21a...first frame, 21b...second frame, 21c...shaft part, 22...casing, 3 1,131...connecting portion, 31a...first connecting portion, 31b...second connecting portion, 32...light-shielding member, 33...rotation suppression portion, 34...spring member, 35...magnet, 40...centrifugal force adjustment member, 100,200...projector, 13c1...first side, 13c2...second side, 311...first connecting portion, 312...second connecting portion, K1,K2,K3,K4...virtual line, O...rotation axis, L...white light (light).

Claims

1. a light source unit that emits light; a light scanning unit that scans the light incident from the light source unit; a movable part that moves in conjunction with the optical scanning part; Equipped with the optical scanning unit has a transmissive optical element including an incident surface on which the light emitted from the light source unit is incident, and an exit surface that is parallel to the incident surface and exits the light that has entered from the incident surface, the transmissive optical element rotates around a rotation axis to scan the light incident from the light source unit over an illuminated area; The movable part is When the transmitting optical element rotates, it does not overlap with the optical path of the light emitted from the light source unit, The optical path of the light emitted from the light source unit overlaps with the optical path of the light transmitting optical element when the transmitting optical element is not rotated. Light source device.

2. the transmissive optical element has a front surface and a back surface that intersect with the rotation axis, and 2×m (m: a natural number equal to or greater than 2) side surfaces that are in contact with the front surface and the back surface, The incident surface and the exit surface are two of the 2×m side surfaces that are parallel to each other. The light source device according to claim 1 .

3. The movable part is connected to the optical scanning part. The light source device according to claim 1 .

4. The movable part is a connecting portion connected to the optical scanning portion; a light blocking member rotatably attached to the connecting portion, the light blocking member overlaps with the optical path of the light emitted from the light source unit when the transmissive optical element is not rotated; The light source device according to claim 3 .

5. the connecting portion is connected to the transmissive optical element, the connecting portion is disposed at a position not overlapping with an optical path of the light emitted from the light source portion, The light source device according to claim 4 .

6. the transmissive optical element includes a first side surface and a second side surface onto which the light from the light source unit is incident, When viewed in a plan view in a direction along the rotation axis of the transmissive optical element, the connecting portion of the movable portion is disposed on a virtual line connecting the rotation axis and an apex where the first side surface and the second side surface intersect.

6. The light source device according to claim 4 or claim 5.

7. the connecting portion includes a first connecting portion connected to one side of the transmissive optical element in a direction along the rotation axis, and a second connecting portion connected to the other side of the transmissive optical element in a direction along the rotation axis, The light source device according to claim 4 .

8. the optical scanning unit includes a holding unit that holds the transmissive optical element and a housing that rotatably supports the holding unit, The holding portion is a first frame connected to a rotation drive device that rotates the transmissive optical element and provided with the first connecting portion; a second frame disposed on the opposite side of the first frame in a direction along the rotation axis, the second frame including the second connecting portion; a shaft portion that protrudes from the second frame along the rotation axis and is rotatably supported by the housing, The light source device according to claim 7 .

9. the optical scanning unit further includes a rotation drive device that rotates the transmissive optical element, The coupling portion is coupled to the rotation drive device. The light source device according to claim 4 .

10. the light blocking member is movable in response to centrifugal force caused by rotation of the transmission optical element, the light blocking member overlaps with the optical path of the light emitted from the light source unit when the centrifugal force falls below a predetermined threshold. The light source device according to claim 4 .

11. the movable portion further includes a rotation suppressing portion that suppresses rotation of the light blocking member relative to the connecting portion, the rotation suppression unit moves the light blocking member in a direction overlapping with an optical path of the light emitted from the light source unit when the centrifugal force falls below the threshold value; The light source device according to claim 10.

12. the rotation suppressing portion includes at least one of a spring member that applies a biasing force to the light blocking member and a magnet that applies a magnetic force to the light blocking member; The light source device according to claim 11.

13. the movable portion further includes a centrifugal force adjusting member that adjusts the magnitude of the centrifugal force acting on the light blocking member. The light source device according to any one of claims 10 to 12.

14. a light source device according to any one of claims 1 to 5 and claims 7 to 12; a light modulation device that modulates the light incident from the light source device based on image information; a projection optical device that projects the light modulated by the light modulation device, projector.

Images