Light source device and projector

Abstract

The invention provides a light source device and a projector, which have a rectangle extending in one direction and generate illumination light with suppressed optical density. This light source device is provided with: a light source unit that emits light including a first light beam; a light amplification optical system that generates amplified light obtained by amplifying light along a first axis; an overlapping optical system that overlaps the amplified light emitted from the light amplifying optical system with a region to be illuminated; and a light scanning unit that scans the amplified light incident from the light amplification optical system in a direction along a second axis orthogonal to the first axis in the region to be illuminated, a cross-section of the first light beam based on a surface orthogonal to the optical axis of the light amplification optical system having a shape having a long side and a short side, the short side of the first light beam being along the first axis.

Description

TECHNICAL FIELD

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

[0002] As a light source device for a projector, a light source device that illuminates a light modulating device such as a liquid crystal panel by scanning light emitted from an optical element on the light modulating device in time has been proposed. A projector having 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 is disclosed in Patent Literature 1 described below.

[0003] Patent Literature 1: Japanese Patent Application Laid-Open No. 2007-225956

[0004] In the projector of Patent Literature 1, the polygon mirror reflects light emitted from the light source device and converges it on the liquid crystal light valve, and thus there is a problem that the light density of illumination light for a rectangle extending in a direction orthogonal to the scanning direction of the liquid crystal light valve becomes high. SUMMARY

[0005] To solve the above problem, according to a first aspect of the present application, there is provided a light source device including: a light source section that emits light including first light rays; a light amplifying optical system that generates amplified light obtained by amplifying the light along a first axis; an overlapping optical system that overlaps the amplified light emitted from the light amplifying optical system with an illuminated region; and a light scanning section that scans the amplified light incident from the light amplifying optical system in the illuminated region in a direction along a second axis orthogonal to the first axis, a cross section of the first light rays based on a face perpendicular to an optical axis of the light amplifying optical system being a shape having a long side and a short side, the short side of the first light rays being along the first axis.

[0006] According to a second aspect of the present application, there is provided a projector including: the light source device of the first aspect; a light modulating device that modulates light incident from the light source device according to image information; and a projection optical device that projects light modulated by the light modulating device. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 is a diagram showing a schematic structure of the projector of the first embodiment viewed from the +Y side.

[0008] Figure 2 is a diagram showing a schematic structure of the projector of the first embodiment viewed from the +Z side.

[0009] Figure 3 is a diagram showing a relationship established among the optical components when viewed from the Y axis direction.

[0010] Figure 4 is a diagram showing the cross-sectional shape of each color light ray emitted from the light source section.

[0011] Figure 5A is an explanatory diagram of the action of the blue light ray when the transmission optical element is rotated.

[0012] Figure 5B is an explanatory diagram of the action of the blue light ray when the transmission optical element is rotated.

[0013] Figure 5C is an explanatory diagram of the action of the blue light ray when the transmission optical element is rotated.

[0014] Figure 5D is an explanatory diagram of the action of the blue light ray when the transmission optical element is rotated.

[0015] Figure 5E is an explanatory diagram of the action of the blue light ray when the transmission optical element is rotated.

[0016] Figure 6 is a diagram showing the action of the light transmitted through the transmission optical element at the time of color switching.

[0017] Figure 7 is a diagram showing the relationship established between the optical components when viewed from the Z-axis direction.

[0018] Figure 8 is a plan view showing the schematic structure of the light amplification optical system of the first modification example, viewed from the +Y side.

[0019] Figure 9 is a perspective view showing the main part of the light source section of the second modification example.

[0020] Figure 10 is a plan view of the projector of the second embodiment, viewed from the +Y side.

[0021] Figure 11 is a plan view of the projector of the second embodiment, viewed from the +Z side.

[0022] BRIEF DESCRIPTION OF THE DRAWINGS

[0023] 1, 101: Light source device; 2: Light modulation device; 2a: Image forming area; 4: Projection optical device; 10, 11: Light source unit; 9: Light emission area; 20, 120, 200: Optical magnification optical system; 21, 121: First cylindrical lens; 21a: First lens; 21b: First substrate; 22, 122: Second cylindrical lens; 22a: Second lens; 22b: Second substrate; 30: Overlapping optical system; 40: Light scanning unit; 50: Field lens; 100, 110: Projector; 10B1: Blue light-emitting element (light-emitting element); 10B2: Collimating lens; 130: Substrate; 130a: First surface; 130b: Second surface; 210: Cylindrical lens; 220: Parallelizing lens; LB: Blue ray (first ray); LG: Green ray (second ray); LR1: Red ray (first ray); LR2: Red ray (third ray). Detailed Implementation

[0024] Hereinafter, an embodiment of the present invention will be described using the accompanying drawings.

[0025] The projector in this embodiment is an example of a liquid crystal projector that uses a liquid crystal panel as a light modulation device.

[0026] In the following figures, to facilitate observation of the constituent elements, the scales of the dimensions may vary depending on the constituent elements. In the following figures, an XYZ orthogonal coordinate system will be used for illustration as needed. The X-axis is an axis parallel to the illumination axis of the light source device. The illumination axis is defined as the axis along the principal ray of the illumination light emitted from the light source device. The Z-axis is an axis perpendicular to the X-axis and is along the rotation axis O of the transmission optical element 41. The Y-axis is an axis perpendicular to both the X-axis and the Z-axis. The Z-axis in this embodiment corresponds to an example of the "first axis" of the present invention, and the Y-axis in this embodiment corresponds to an example of the "second axis" of the present invention.

[0027] In the following description of the structure and configuration of each component, the side (+X side) and the other side (-X side) along the X-axis direction will sometimes be referred to as the "X-axis direction", the side (+Y side) and the other side (-Y side) along the Y-axis direction will be referred to as the "Y-axis direction", and the side (+Z side) and the other side (-Z side) along the Z-axis direction will be referred to as the "Z-axis direction".

[0028] Figure 1 This is a top view showing the schematic structure of the projector of this embodiment as viewed from the +Y side.

[0029] Figure 2 This is a top view showing the schematic structure of the projector of this embodiment as viewed from the +Z side.

[0030] like Figure 1 andFigure 2 As shown in the figure, the projector 100 of the present embodiment has a light source device 1, a light modulation device 2, an incident-side polarizing plate 3a, an emission-side polarizing plate 3b, and a projection optical device 4.

[0031] The light source device 1 has a light source section 10, a light amplification optical system 20, a superposition optical system 30, a light scanning section 40, and a field lens 50.

[0032] The light source section 10 includes a blue light emitting section 10B, a green light emitting section 10G, and a red light emitting section 10R. The light source section 10 causes the blue light emitting section 10B, the green light emitting section 10G, and the red light emitting section 10R to emit light at different timings, respectively. The blue light emitting section 10B, the green light emitting section 10G, and the red light emitting section 10R of the light source section 10 of the present embodiment are constituted by one package structure. Alternatively, the blue light emitting section 10B, the green light emitting section 10G, and the red light emitting section 10R can have independent package structures.

[0033] The blue light emitting section 10B includes a blue light emitting element 10B1, which is a laser diode that emits blue light rays LB, and a collimator lens 10B2 that parallelizes the blue light rays LB. The blue light rays LB are, for example, laser light having a blue wavelength band of 450 nm ± 5 nm.

[0034] The green light emitting section 10G includes a green light emitting element 10G1, which is a laser diode that emits green light rays LG, and a collimator lens 10G2 that parallelizes the green light rays LG. The green light rays LG are, for example, laser light having a green wavelength band of 530 nm ± 5 nm.

[0035] The red light emitting section 10R includes a red light emitting element 10R1, which is constituted by a laser diode that emits red light rays LR, and a collimator lens 10R2 that parallelizes the red light rays LR. The red light rays LR are, for example, laser light having a red wavelength band of 650 nm ± 5 nm.

[0036] The light emitting surfaces of the light emitting elements 10B1, 10G1, 10R1 of the respective light emitting sections 10B, 10G, 10R are arranged on the same plane. That is, in other words, the light source section 10 of the present embodiment emits illumination light L that includes a plurality of light rays LB, LG, LR of respective colors emitted from light emitting points on the same plane.

[0037] In the present embodiment, the blue light rays LB correspond to an example of the "first light rays" of the present application, the green light rays LG correspond to an example of the "second light rays" of the present application, and the red light rays LR correspond to an example of the "third light rays" of the present application.

[0038] According to such a configuration, the light source section 10 of the present embodiment emits the illumination light L containing the light rays LB, LG, LR of each color emitted in time series toward the light amplifying optical system 20. Therefore, the illumination light L emitted by the light source section 10 becomes monochromatic light containing any one of the light rays LB, LG, LR of each color. In the illumination light L emitted by the light source section 10, the blue light rays LB, the green light rays LG, and the red light rays LR are arranged in the Y-axis direction. That is, the blue light rays LB, the green light rays LG, and the red light rays LR are incident on the light amplifying optical system 20 through different optical paths.

[0039] The light amplifying optical system 20 amplifies the illumination light L emitted from the light source section 10 in the Z-axis direction, and generates the rectangularly shaped amplified illumination light WL extending along the Z-axis. The amplified illumination light WL of the present embodiment corresponds to an example of the "amplified light" of the present application.

[0040] The light amplifying optical system 20 of the present embodiment has a first cylindrical lens 21 and a second cylindrical lens 22. In the present embodiment, the first cylindrical lens 21 and the second cylindrical lens 22 are separate lenses, and thus the manufacture of the lenses becomes easy.

[0041] The first cylindrical lens 21 and the second cylindrical lens 22 have the same shape. Therefore, the lens pitch of the first cylindrical lens 21 and the second cylindrical lens 22 is equal.

[0042] The first cylindrical lens 21 includes a first base material 21b that is a light-transmissive substrate in a flat plate shape, and a plurality of first lenses 21a provided to the first base material 21b. The plurality of first lenses 21a are provided to the first base material 21b in a manner of being arranged in the Z-axis direction. Each first lens 21a is a cylindrical convex lens having positive refractive power in the Z-axis direction and having no refractive power in the Y-axis direction. Therefore, each first lens 21a divides the illumination light L incident from the light source section 10 into a plurality of light ray bundles in the Z-axis direction. Each light ray bundle is diffused in the Z-axis direction having the lens refractive power.

[0043] The second cylindrical lens 22 includes a second base material 22b that is a light-transmissive substrate in a flat plate shape, and a plurality of second lenses 22a provided to the second base material 22b. The plurality of second lenses 22a are provided to the second base material 22b in a manner of being arranged in the Z-axis direction. The plurality of second lenses 22a respectively correspond to the plurality of first lenses 21a of the first cylindrical lens 21. Each second lens 22a is a cylindrical convex lens having positive refractive power in the Z-axis direction and having no refractive power in the Y-axis direction.

[0044] The second cylindrical lens 22, together with the rear-stage overlapping optical system 30, images the image of each first lens 21a of the first cylindrical lens 21 in the image forming region 2a of the light modulating device 2 or in the vicinity thereof, which is the illuminated region, in the Z-axis direction having the lens refractive power.

[0045] The first cylindrical lens 21 and the second cylindrical lens 22 transmit the illumination light L incident from the light source section 10 without changing the traveling direction of the illumination light L in the Y-axis direction in which the lens power is not present. The illumination light L that has been transmitted through the first cylindrical lens 21 and the second cylindrical lens 22 in the Y-axis direction is condensed by the superposition optical system 30 on or near the image formation region 2a of the light modulation device 2.

[0046] Thus, the light amplification optical system 20 of the present embodiment diffuses the illumination light L emitted from the light source section 10 in the Z-axis direction, and generates rectangular amplified illumination light WL extending in the Z-axis direction.

[0047] Further, the rate of change of the beam width (diffusion degree) in the Z-axis direction in the light amplification optical system 20 can be adjusted, for example, by adjusting the optical characteristics such as the curvature and the refractive index of each lens constituting the first cylindrical lens 21 and the second cylindrical lens 22.

[0048] The light scanning section 40 scans the amplified illumination light WL incident from the light amplification optical system 20 in the Y-axis direction in the illuminated region. Specifically, the light scanning section 40 scans the band-shaped amplified illumination light WL extending in the Z-axis direction in the image formation region 2a of the light modulation device 2 disposed in the illuminated region in the Y-axis direction. Thus, the light scanning section 40 can efficiently illuminate the entire image formation region 2a by scanning the band-shaped amplified illumination light WL in the short side direction thereof. The amplified illumination light WL overlaps each other in the Y-axis direction, and thus the uniformity of the intensity distribution of the image formation region 2a can be improved.

[0049] In the present embodiment, a field lens 50 is provided between the light scanning section 40 and the light modulation device 2. The field lens 50 deflects the amplified illumination light WL incident from the light scanning section 40. Thus, the light scanning section 40 can efficiently illuminate the image formation region 2a of the light modulation device 2 with the amplified illumination light WL.

[0050] In the present embodiment, the light scanning section 40 scans the amplified illumination light WL incident from the superposition optical system 30 in the Y-axis direction on the image formation region 2a of the light modulation device 2.

[0051] The light scanning section 40 has a transmissive optical element 41 and a rotation driving section 45.

[0052] The transmissive optical element 41 is constituted by a light-transmissive member supported so as to be rotatable. The transmissive optical element 41 can rotate about a rotation axis O extending in the Z-axis direction. The transmissive optical element 41 is linked to the rotation driving section 45 constituted by a motor or the like. The transmissive optical element 41 rotates about the rotation axis O by the driving of the rotation driving section 45.

[0053] As the glass material constituting the light-transmissive member of the transmission optical element 41, an optical glass such as BK7, quartz, a resin, or the like is used. The transmission optical element 41 of the present embodiment has a surface 41a and a back surface 41b intersecting the rotation axis O, and four side surfaces 41c in contact with the surface 41a and the back surface 41b perpendicularly. That is, the transmission optical element 41 has a shape of a regular quadrangular prism having six planes including the surface 41a, the back surface 41b, and the four side surfaces 41c. The cross-sectional shape of the transmission optical element 41 obtained by cutting with a plane perpendicular to the rotation axis O is a square. That is, the four side surfaces 41c have the same area, and the two side surfaces opposing each other are parallel to each other. The rotation axis O coincides with the center of the square transmission optical element 41.

[0054] The transmission optical element 41 transmits the magnified illumination light WL emitted from the light magnifying optical system 20 while rotating around the rotation axis O. Therefore, the side surface of the transmission optical element 41 on which the magnified illumination light WL emitted from the light magnifying optical system 20 is incident is not fixed to one, but varies with time. Similarly, the side surface of the transmission optical element 41 on which the magnified illumination light WL incident thereto is emitted to the outside is not fixed to one, but varies with time. In the transmission optical element 41, the side surface on which the magnified illumination light WL emitted from the light magnifying optical system 20 is incident is referred to as an "incident surface". The side surface on which the magnified illumination light WL incident to the incident surface is emitted is referred to as an "emission surface". In this case, the incident surface and the emission surface vary with time, and are any one of the two side surfaces parallel to each other among the four side surfaces 41c.

[0055] In the present specification, in the case where two surfaces of the transmission optical element 41 are parallel to each other, the angle formed by the two surfaces is referred to as "parallel" in the case where the angle is within a range of 0 ± 5 degrees, considering the machining accuracy of the glass material constituting the light-transmissive member, the allowable range of parallelism of light, and the like.

[0056] In the case of the present embodiment, the transmission optical element 41 has four side surfaces 41c, but the number of side surfaces can not necessarily be four, and is preferably 2 x m (m: a natural number of 2 or more). That is, the number of side surfaces is preferably an even number such as six, eight, or the like. If the number of side surfaces is an even number, all the side surfaces are parallel to the side surface opposing thereto, and there is no side surface that is not parallel. Thus, the generation of stray light in the transmission optical element 41 is less, and the light utilization efficiency can be improved.

[0057] The light modulating device 2 is disposed on the light emission side of the light scanning section 40 on the illumination light axis AX. The light modulating device 2 modulates the magnified illumination light WL emitted from the light scanning section 40 according to image information, and forms image light. The light modulating device 2 uses a transmissive liquid crystal panel. As a driving method of the liquid crystal panel, a twisted nematic (TN) method, a vertical alignment (VA) method, an in-plane switching (IPS) method, or the like is used, and is not particularly limited.

[0058] Here, the size of the magnified illumination light WL in the Z-axis direction that illuminates the image formation region 2a of the light modulating device 2 is preferably set to be slightly larger than the size of the image formation region 2a of the light modulating device 2. The present inventors have obtained the following insight based on simulation: it is desirable to expand the size of the magnified illumination light WL outward by 0.5 mm or more.

[0059] Figure 3 is a view showing the relationship established between the optical components when viewed in the Y-axis direction. In Figure 3 , the illustration of the light scanning section 40, the field lens 50, and the incident-side polarizing plate 3a that are not used in the explanation are omitted for easy viewing of the figure.

[0060] In Figure 3 , the lens pitch of the first cylindrical lens 21 and the second cylindrical lens 22 is set to a, the beam width of the magnified illumination light WL in the Z-axis direction is set to a1, the inter-lens distance of the first cylindrical lens 21 and the second cylindrical lens 22 is set to b, and the distance between the superposition optical system 30 and the light modulating device 2 is set to b1.

[0061] The light emitted from the first lens 21a of the first cylindrical lens 21 is parallelized by the second lens 22a of the second cylindrical lens 22, and is imaged on the image formation region 2a of the light modulating device 2 by the superposition optical system 30. Therefore, in the above lens pitch a, the beam width a1, the inter-lens distance b, and the distance b1, the relationship a:a1=b:b1 is established. Therefore, the beam width a1 is defined by a1=a×b1 / b.

[0062] As described above, the beam width of the magnified illumination light WL in the Z-axis direction preferably has a margin of 1.0 mm or more on both sides. Therefore, when the margin of the magnified illumination light WL is taken into account, the size S of the image formation region 2a in the Z-axis direction satisfies the following relationship of Equation (1).

[0063] S<(a×b1 / b)-1.0 Equation (1)

[0064] If Equation (1) above is satisfied, the magnified illumination light WL can well illuminate the image formation region 2a of the light modulating device 2 even in the case of installation deviation of the optical components or poor precision of the cylindrical lenses.

[0065] Here, as Figure 1 As shown, the magnified illumination light WL is divided into multiple overlapping diffused beams along the Z-axis. Therefore, the uniformity of the optical density along the Z-axis of the magnified illumination light WL is relatively high.

[0066] On the other hand, such as Figure 2 As shown, the magnified illumination light WL is incident on the image forming region 2a of the optical modulation device 2 in a converging state along the Y-axis. Therefore, the optical density of the magnified illumination light WL in the Y-axis direction tends to be relatively high. Thus, if the optical density becomes too high, it may cause heat-induced damage to the image forming region 2a of the optical modulation device 2 and the incident-side polarizer 3a, which will be described later, thereby reducing reliability.

[0067] In contrast, the inventors investigated a structure that could suppress the optical density in the Y-axis direction of the amplified illumination light WL to a lower level, and obtained the following insight: the optical density in the illuminated area varies depending on the orientation of the various colored rays LB, LG, LR emitted from the light-emitting portions 10B, 10G, 10R of the light source 10 and the amplification direction (Z-axis direction) of the illumination light L by the optical amplification system 20. Then, the inventors completed the light source device 1 of this embodiment.

[0068] Next, the cross-sectional shapes of the various colored rays LB, LG, and LR emitted from the light source 10 will be explained.

[0069] Figure 4 It is a diagram showing the cross-sectional shapes of the various colored rays LB, LG, and LR emitted from the light source 10. Figure 4 The cross-sectional shapes of the planes perpendicular to the principal ray for each color ray LB, LG, and LR are shown. Furthermore, the principal rays of each color ray LB, LG, and LR are parallel to the illumination optical axis AX.

[0070] like Figure 4 As shown, in the light source unit 10 of this embodiment, the light-emitting surfaces of the light-emitting elements 10B1, 10G1, and 10R1 of each light-emitting unit 10B, 10G, and 10R are rectangular. For example, the cross-section of the blue light ray LB emitted from the blue light-emitting element 10B1 is an elliptical shape having a long side (major axis) along the short side direction of the rectangular light-emitting surface and a short side (minor axis) along the long side direction of the rectangular light-emitting surface. The cross-sections of the green light ray LG emitted from the green light-emitting element 10G1 and the red light ray LR emitted from the red light-emitting element 10R1 are also elliptical in shape, similar to the blue light ray LB.

[0071] The short sides of the blue light LB, the green light LG, and the red light LR are in the Z-axis direction. In addition, the long sides of the blue light LB, the green light LG, and the red light LR are in the Y-axis direction. The blue light LB, the green light LG, and the red light LR are arranged in the Y-axis direction.

[0072] In the light source device 1 of the present embodiment, the light amplification direction (Z-axis direction) of the light amplification optical system 20 that amplifies the illumination light WL coincides with the short side direction of each of the blue light LB, the green light LG, and the red light LR that is emitted from the light source unit 10 as the illumination light L and that is incident on the light amplification optical system 20. That is, the light amplification optical system 20 does not diffuse each of the blue light LB, the green light LG, and the red light LR in the long side direction, but diffuses each of the blue light LB, the green light LG, and the red light LR in the short side direction to generate the amplified illumination light WL.

[0073] According to this structure, compared with a case in which each of the blue light LB, the green light LG, and the red light LR is amplified in the long side direction, by diffusing each of the blue light LB, the green light LG, and the red light LR in the short side direction, it is possible to suppress the optical density of the amplified illumination light WL to be lower.

[0074] Here, the ratio of the length of the long side direction to the length of the short side direction of the cross section of each of the blue light LB, the green light LG, and the red light LR is referred to as an aspect ratio. That is, a light ray having a large aspect ratio has an elongated shape compared with a light ray having a small aspect ratio.

[0075] In the light source device 1 of the present embodiment, the long side direction of the aspect ratio of the cross section of the illumination light L emitted from the light source unit 10 is the Y-axis direction as shown in FIG. 1. Figure 4 Here, in a case in which each of the blue light LB, the green light LG, and the red light LR is emitted in time series as in the light source unit 10 of the present embodiment, the aspect ratio of the cross section of the illumination light L corresponds to the aspect ratio of the cross section of each of the blue light LB, the green light LG, and the red light LR. In addition, in a case in which a plurality of (for example, two) each of the blue light LB, the green light LG, and the red light LR is emitted from the light source unit 10, a region that contains two each of the blue light LB, the green light LG, and the red light LR corresponds to the cross section of the illumination light L, and the aspect ratio of the region corresponds to the aspect ratio of the illumination light L.

[0076] On the other hand, as shown in FIG. 2 and FIG. 3, the long side direction of the aspect ratio of the cross section of the amplified illumination light WL emitted from the light amplification optical system 20 is the Z-axis direction. Figure 1 and Figure 2 That is, in the present embodiment, the light amplification optical system 20 amplifies each of the blue light LB, the green light LG, and the red light LR that has a long side in the Y-axis direction in the Z-axis direction, and it is possible to generate the amplified illumination light WL that has a long side in the Z-axis direction well.

[0077] The present inventors have obtained the insight that the more the color light rays LB, LG, LR emitted from the light source section 10 have an elongated shape, the greater the effect of aligning the light amplification direction of the amplified illumination light WL with the short direction of the color light rays LB, LG, LR. Therefore, in the light source device 1 of the present embodiment, the aspect ratios of the blue light rays LB, the green light rays LG, and the red light rays LR are each set to 3 times or more. In this way, by using the light source section 10 that emits illumination light L containing light rays having an aspect ratio of 3 times or more, it is possible to further improve the suppression effect of the light density of the amplified illumination light WL.

[0078] An incident-side polarizing plate 3a is disposed on the light incident side of the light modulating device 2 on the illumination light axis AX. An emission-side polarizing plate 3b is disposed on the light emission side of the light modulating device 2 on the illumination light axis AX. The transmission axes of the incident-side polarizing plate 3a and the emission-side polarizing plate 3b are orthogonal to each other.

[0079] The incident-side polarizing plate 3a transmits linearly polarized light components in a specific direction in the amplified illumination light WL emitted from the light source section 10 toward the light modulating device 2. The emission-side polarizing plate 3b transmits linearly polarized light in a specific direction emitted from the light modulating device 2 toward the projection optical device 4. In the case of the present embodiment, since the light source section 10 uses a laser light emitting element, the illumination light L incident from the light source section 10 becomes linearly polarized light. However, in the transmission optical element 41, as the amount of light that transmits the light-transmissive member increases, the amount of light that is absorbed by the light-transmissive member also increases, and sometimes thermal strain occurs in the light-transmissive member. In this case, the polarization direction of the illumination light L emitted from the light source section 10 becomes disordered, and the linearly polarized light incident on the light-transmissive member becomes elliptically polarized light and is emitted from the light-transmissive member. In the case of the present embodiment, by providing the incident-side polarizing plate 3a, even in the case where the polarization direction of the illumination light L has become disordered, it is possible to cause linearly polarized light components in a specific direction to be incident on the light modulating device 2.

[0080] In addition, in the case where a glass material having a small Young's modulus and a small thermal expansion coefficient, i.e., quartz, is used as the transmission optical element 41, it is not easy for the polarization direction to become disordered, and therefore it is also possible to omit the incident-side polarizing plate 3a provided on the light incident side of the light modulating device 2.

[0081] The projection optical device 4 is composed of a plurality of projection lenses. The projection optical device 4 amplifies and projects the image light modulated by the light modulating device 2 toward a projection target such as a screen. As a result, an image is displayed on the projection target.

[0082] Hereinafter, the operation when the amplified illumination light WL transmits the transmission optical element 41 will be described in detail. In addition, the operations of the color light rays LB, LG, LR included in the amplified illumination light WL are the same, and therefore, hereinafter, the operation of the blue light rays LB and the operation when the blue light rays LB are switched to the green light rays LG will be described.

[0083] Figures 5A to 5E is a diagram for explaining the action of the blue light ray LB when the transmission optical element 41 rotates. In this example, a state is shown in which, as viewed from the +Z side, the transmission optical element 41 rotates clockwise around the rotation axis O, and the blue light ray LB is incident on the end portion 41c2 of the side surface 41c2 on the +Y side. Figure 5A toward Figure 5E passes time. In Figures 5A to 5E the illustration of the rotation driving section 45 is omitted.

[0084] In Figures 5A to 5E , the angle formed by the straight line M of the intersection point, i.e., the top portion 41d1, of the connecting side surfaces 41c1 and 41c2 and the rotation axis O and the illumination optical axis AX is defined as the rotation angle ω of the transmission optical element 41. In addition, the blue light ray LB actually has a prescribed beam width in the Z-axis direction, but the action of the chief ray traveling on the illumination optical axis AX is considered here.

[0085] In addition, in Figures 5A to 5E , the displacement amount m of the chief ray of the blue light ray LB with respect to the illumination optical axis AX is shown on the left side, and a case in which the blue light ray LB scans the image formation region 2a as the illuminated region is shown on the right side.

[0086] Figure 5A is a diagram showing an initial state in which the blue light ray LB is incident on the transmission optical element 41. In Figure 5A the state shown, the straight line M overlaps the illumination optical axis AX, and the rotation angle ω is 0 degrees. At this time, the blue light ray LB is incident on the end portion of the +Y side of the side surface 41c2 at an incident angle (45 degrees). The blue light ray LB is refracted in the direction shown (+Y side) and travels inside the transmission optical element 41. Next, the blue light ray LB is also incident on the side surface 41c4 at the same incident angle as the side surface 41c2, and thus is refracted at the side surface 41c4 and emitted from the transmission optical element 41. At this time, the side surface 41c2 and the side surface 41c4 are parallel to each other, and thus the incident angle of the blue light ray LB with respect to the side surface 41c2 is equal to the incident angle of the blue light ray LB with respect to the side surface 41c4, and the refractive angle of the blue light ray LB incident on the side surface 41c2 is opposite in sign and equal in absolute value to the refractive angle of the blue light ray LB emitted from the side surface 41c4. As a result of this, the refractive angle when the blue light ray LB is incident on the side surface 41c2 and the refractive angle when the blue light ray LB is emitted from the side surface 41c4 cancel out. As a result, the blue light ray LB travels in parallel with the illumination optical axis AX at a position displaced from the illumination optical axis AX by the displacement amount m in the +Y side.

[0087] As a result of this, the blue light ray LB emitted from the transmission optical element 41 is incident on the end portion 2a1 of the +Y side of the image formation region 2a of the light modulating device 2 as the illuminated region.

[0088] Next, as Figure 5B As shown, when the rotation angle ω of the transmission optical element 41 is compared to... Figure 5A When the angle of incidence of the blue ray LB is large, the angle of refraction also decreases. Therefore, the displacement m of the blue ray LB relative to the illumination optical axis AX is greater than that of the ray LB. Figure 5A The time is small. Furthermore, the blue light LB is always kept parallel to the illumination optical axis AX. During the rotation angle ω from 0 degrees to 45 degrees, the displacement m decreases monotonically with increasing rotation angle ω.

[0089] Therefore, with Figure 5A In contrast, blue light LB emitted from the transmission optical element 41 is incident on the -Y side of the image forming region 2a of the light modulation device 2.

[0090] Next, as Figure 5C As shown, when the rotation angle ω of the transmission optical element 41 becomes more than... Figure 5B At a greater 45 degrees, the straight line M overlaps with the illumination optical axis AX, and the blue light LB is incident perpendicularly to the side 41c2. That is, the incident angle of the blue light LB relative to the side 41c2 is 0 degrees. Therefore, since the blue light LB is incident perpendicularly to the side 41c2, it will not be refracted at the side 41c2, but will travel along the illumination optical axis AX inside the transmission optical element 41. Next, the blue light LB is also incident perpendicularly to the side 41c4, which is parallel to the side 41c2. Therefore, the blue light LB is emitted from the transmission optical element 41 at the side 41c4 without refraction and travels along the illumination optical axis AX. At this time, the blue light LB emitted from the transmission optical element 41 is incident on the central part of the image forming region 2a of the light modulation device 2 in the Y-axis direction.

[0091] Next, as Figure 5D As shown, when the rotation angle ω of the transmission optical element 41 exceeds 45 degrees, the incident position of the blue light LB changes from the center of side 41c2 towards side 41c3. At this time, the blue light LB is refracted at side 41c2, but the direction of refraction is different from that at the center of side 41c2. Figure 5B The refraction occurs in the direction shown in the diagram (-Y side) at different times. Furthermore, the relationship between the angle of refraction when the blue ray LB is incident on side 41c2 and the angle of refraction when it exits from side 41c4 is the same as that before... Figure 5B The same period applies up to this point. As a result, the blue ray LB travels parallel to the illumination axis AX at a position where it has been displaced by a displacement m from the illumination axis AX to the -Y side. During the rotation angle ω from 45 degrees to 90 degrees, the displacement m increases monotonically with the increase of the rotation angle ω.

[0092] Thus, the blue light LB emitted from the transmission optical element 41 is incident to a position on the -Y side of the central portion of the image forming region 2a of the light modulation device 2.

[0093] Next, as shown in Figure 5E , the rotation angle ω of the transmission optical element 41 becomes maximum, maintaining a state in which the blue light LB travels in parallel with the illumination optical axis AX, and the displacement amount m becomes maximum.

[0094] Thus, the blue light LB emitted from the transmission optical element 41 is incident to the end portion 2a2 on the -Y side of the image forming region 2a of the light modulation device 2 that is the illuminated region.

[0095] Thus, the blue light LB incident to the side surface 41c2 of the rotating transmission optical element 41 can scan the image forming region 2a of the light modulation device 2 in the Y-axis direction.

[0096] In Figure 5E the state shown in FIG. 14, the top portion 41d2 of the transmission optical element 41 located at the boundary of the side surface 41c2 and the side surface 41c3 overlaps with the illumination optical axis AX. In the case of the present embodiment, at the timing shown in Figure 5E , the light source portion 10 switches the emitted illumination light L from the blue light LB to the green light LG.

[0097] Figure 6 is a view showing the behavior of light that passes through the transmission optical element 41 when switching from the blue light LB to the green light LG.

[0098] As shown in Figure 6 , at the timing at which the top portion 41d2 of the transmission optical element 41 overlaps with the illumination optical axis AX, the blue light LB or the green light LG is incident to both the side surface 41c2 and the side surface 41c3 of the transmission optical element 41, and is emitted from the side surface 41c4 and the side surface 41c1, respectively. That is, at the time of switching from the blue light LB to the green light LG, the blue light LB and the green light LG emitted from the transmission optical element 41 are separated into two in the Y-axis direction. For example, in the case where the blue light LB and the green light LG are incident to both ends in the Y-axis direction of the image forming region 2a, respectively, different color lights are incident to the same region (both ends in the Y-axis direction) of the image forming region 2a in time series, causing a quality reduction of the projection image due to color mixing.

[0099] In contrast, in the projector 100 of the present embodiment, the size of the image forming region 2a is set in such a manner that, in the case where the magnified illumination light WL is separated into two in the Y-axis direction when passing through the transmission optical element 41, the two separated lights are caused to be incident to the outside of the image forming region 2a. Thus, it is possible to suppress the generation of color mixing.

[0100] However, if the light beam width of the illumination light L emitted from the light source section 10 in the Y-axis direction is increased, the following problems arise: the time during which the illumination light L is separated into two increases, the time during which the illumination light L emitted from the light source section 10 does not impinge on the image formation region 2a increases, and the utilization efficiency of the illumination light L emitted from the light source section 10 decreases.

[0101] The present inventors believe that if the light beam width of the illumination light L is too narrow, the image formation region 2a is locally heated, and, on the contrary, if the light beam width of the illumination light L is too wide, the utilization efficiency of the illumination light L decreases as described above, and therefore the light beam width of the illumination light L is preferably one-half or less of the image formation region 2a.

[0102] Figure 7 is a view showing the relationship established between the optical components when viewed in the Z-axis direction. In Figure 7 , the illustration of the light scanning section 40, the field lens 50, and the incident-side polarizing plate 3a, which are not used in the explanation, is omitted. In addition, in Figure 7 , the blue light emitting section 10B in the light source section 10 is illustrated.

[0103] In Figure 7 , let the dimension in the Y-axis direction of the light emitting region 9 of the light emitting element 10B1 of the blue light emitting section 10B be c, the light beam width of the magnified illumination light WL in the Y-axis direction be cl, the focal length of the collimator lens 10B2 of the blue light emitting section 10B be d, and the distance between the overlapping optical system 30 and the light modulating device 2 be dl.

[0104] The blue light rays LB emitted from the light emitting region 9 of the light emitting element 10B1 are parallelized by the collimator lens 10B2. The first cylindrical lens 21 and the second cylindrical lens 22 do not have lens power in the Y-axis direction, and therefore the blue light rays LB parallelized by the collimator lens 10B2 pass through the first cylindrical lens 21 and the second cylindrical lens 22. Then, the blue light rays LB are imaged on the image formation region 2a of the light modulating device 2 by the overlapping optical system 30. Therefore, in the above-described dimension c of the light emitting region 9, the light beam width cl, the focal length d, and the distance dl, the relationship c: cl = d: dl holds. Therefore, the light beam width cl is defined by cl = c x dl / d.

[0105] As described above, in consideration of heating and decrease in light utilization efficiency, it is desirable that the light beam width of the magnified illumination light WL in the Y-axis direction be one-half or less of the image formation region 2a. Therefore, in the projector 100 of the present embodiment, the dimension S1 of the image formation region 2a in the Y-axis direction satisfies the following relationship of Equation (2).

[0106] S1 > 2 x c x dl / d Equation (2)

[0107] If the above formula (2) is satisfied, the heat generation of the image forming region can be suppressed, and the light from the light source device efficiently enters the image forming region.

[0108] As described above, the light source device 1 of the present embodiment has the light source section 10 that emits the illumination light L including the blue light ray LB, the green light ray LG, and the red light ray LR, the light amplification optical system 20 that generates the amplified illumination light WL obtained by amplifying the illumination light L in the Z-axis direction, and the light scanning section 40 that scans the amplified illumination light WL incident from the light amplification optical system 20 in the image forming region 2a of the light modulation device 2 as the illuminated region in the Y-axis direction. The cross section of the blue light ray LB based on the YZ plane perpendicular to the chief ray is an elliptical shape having a long side and a short side, and the short side of the blue light ray LB when incident to the light amplification optical system 20 is along the Z-axis.

[0109] According to the light source device 1 of the present embodiment, the illumination light L emitted from the light source section 10 can be converted into the amplified illumination light WL that becomes a long rectangular shape in the Z-axis direction by the light amplification optical system 20. In the case of the present embodiment, the light amplification optical system 20 diffuses each color light ray LB, LG, LR in the short side direction to generate the amplified illumination light WL, and thus, the optical density of the amplified illumination light WL can be suppressed to be low. Therefore, the light scanning section 40 can suppress the damage caused by heat in the incident side polarizing plate 3a and the light modulation device 2, and illuminate the entire region of the image forming region 2a of the light modulation device 2.

[0110] According to the projector 100 of the present embodiment, the amplified illumination light WL emitted from the light source device 1 is scanned on the image forming region 2a of the light modulation device 2, and thus, a bright image can be projected. Further, since the optical density of the amplified illumination light WL is suppressed, the damage caused by heat in the light modulation device 2 is suppressed, and the reliability of the projector 100 can be further improved.

[0111] (First Modified Example)

[0112] Hereinafter, a first modified example of the above-described embodiment will be described.

[0113] The structure of the light amplification optical system of the present modified example is different from that of the above-described embodiment. Further, the same reference numerals are assigned to the components common to the above-described embodiment, and detailed description will be omitted.

[0114] Figure 8 is a plan view showing the schematic structure of the light amplification optical system 120 of the present modified example as viewed from the +Y side.

[0115] As Figure 8As shown, the optical magnification system 120 of this modified example includes a first lenticular lens 121, a second lenticular lens 122, and a substrate 130. The substrate 130 is a light-transmitting substrate, with the first lenticular lens 121 disposed on a first surface 130a side and the second lenticular lens 122 disposed on a second surface 130b side opposite to the first surface 130a. That is, in the optical magnification system 120 of this modified example, the first lenticular lens 121 and the second lenticular lens 122 are an integral lens.

[0116] In this modified example, since the first cylindrical lens 121 and the second cylindrical lens 122 are integral lenses, alignment of the first cylindrical lens 121 and the second cylindrical lens 122 is not required. Therefore, the assembly process can be simplified according to the light source device using the optical magnification optical system 120 of this modified example.

[0117] (Second variation)

[0118] The following describes a second variation of the above-described embodiment.

[0119] The structure of the light source unit in this variation differs from that in the above embodiment. Furthermore, components common to the above embodiment are labeled with the same reference numerals, and detailed descriptions are omitted.

[0120] Figure 9 This is a perspective view showing the main parts of the light source section 11 in this modified example.

[0121] like Figure 9 As shown, the light source unit 11 of this modified example includes a blue light-emitting unit 60B, a green light-emitting unit 60G, a first red light-emitting unit 60R, and a second red light-emitting unit 61R. The light source unit 11 causes the blue light-emitting unit 60B, the green light-emitting unit 60G, the first red light-emitting unit 60R, and the second red light-emitting unit 61R to emit light at different timings.

[0122] The blue light-emitting part 60B has the same structure as the blue light-emitting part 10B in the first embodiment and emits blue light rays LB. The green light-emitting part 60G has the same structure as the green light-emitting part 10G in the first embodiment and emits green light rays LG. The first red light-emitting part 60R and the second red light-emitting part 61R have the same structure as the red light-emitting part 10R in the first embodiment and emit red light rays LR1 and LR2 respectively.

[0123] In this modified example, the blue light-emitting part 60B, the green light-emitting part 60G, and the first red light-emitting part 60R are arranged sequentially from the +Y side to the -Y side. The second red light-emitting part 61R is arranged side by side with the first red light-emitting part 60R in the Z-axis direction.

[0124] That is, in the present modification example, the illumination light L emitted from the light source section 11 contains the blue light rays LB, the green light rays LG, the red light rays LR1 arranged in the Y-axis direction, and the red light rays LR2 juxtaposed with the red light rays LR1 in the Z-axis direction. Therefore, in the case of the present modification example, the beam width in the Z-axis direction of the illumination light L emitted from the light source section 11 becomes large.

[0125] In the present embodiment, the red light rays LR1 correspond to an example of the "first light rays" of the present application, the green light rays LG correspond to an example of the "second light rays" of the present application, and the red light rays LR2 correspond to an example of the "third light rays" of the present application.

[0126] In the present modification example, the cross sections of the blue light rays LB, the green light rays LG, the red light rays LR1, and the red light rays LR2 also have an elliptical shape as shown in FIG. 6B. The short sides of the blue light rays LB, the green light rays LG, the red light rays LR1, and the red light rays LR2 respectively follow the Z-axis direction, and the long sides of the blue light rays LB, the green light rays LG, the red light rays LR1, and the red light rays LR2 respectively follow the Y-axis direction. Figure 9

[0127] In the present modification example, by making the light amplification direction of the light amplification optical system 20 amplifying the illumination light WL coincide with the short side direction of each of the color light rays LB, LG, LR1, and LR2, it is also possible to suppress the optical density of the amplified illumination light WL to be lower.

[0128] In addition, according to the light source section 11 of the present modification example, by increasing the number of red light rays LR, which are prone to be insufficient in light quantity compared to the blue light rays LB and the green light rays LG, to two, it is possible to further improve the color balance of the illumination light L.

[0129] In the present modification example, the case where the red light rays are set to two is exemplified, but it is also possible to increase the number of blue light rays and green light rays to two respectively. That is, it is possible to arrange two blue light emitting sections 60B in the Y-axis direction, and it is also possible to arrange two green light emitting sections 60G in the Y-axis direction.

[0130] The light amplification optical system 20 does not affect the beam width in the Z-axis direction of the amplified illumination light WL even in the case where the beam width in the Z-axis direction of the illumination light L incident from the light source section 11 changes. Therefore, according to the light source device of the present application, it is possible to generate the rectangular amplified illumination light WL elongated in the Z-axis direction by the light amplification optical system 20 regardless of the beam width of the illumination light L emitted from the light source section 11.

[0131] (Second Embodiment)

[0132] Hereinafter, the projector of the second embodiment will be described.

[0133] ​The configuration of the light amplification optical system of the projector of this embodiment is different from that of the first embodiment. Furthermore, the same reference numerals are given to components common to the above-described embodiments, and detailed description is omitted.

[0134] Figure 10 is a plan view showing the schematic configuration of the projector of this embodiment as viewed from the +Y side. Figure 11 is a plan view showing the schematic configuration of the projector of this embodiment as viewed from the +Z side.

[0135] As shown in Figure 10 and Figure 11 , the projector 110 of this embodiment has a light source device 101, a light modulation device 2, an incident-side polarizing plate 3a, an emission-side polarizing plate 3b, and a projection optical device 4. The light source device 101 has a light source section 10, a beam width reducing optical system 70, a light amplification optical system 200, a superposition optical system 30, and a light scanning section 40.

[0136] As shown in Figure 11 , the beam width reducing optical system 70 has a first mirror 71, a second mirror 72, a first dichroic mirror 74, and a second dichroic mirror 73. The first mirror 71 is disposed on the optical path of the blue light ray LB emitted from the blue light emitting section 10B of the light source section 10, and reflects the blue light ray LB toward the illumination optical axis AX. The second mirror 72 is disposed on the optical path of the red light ray LR emitted from the red light emitting section 10R of the light source section 10, and reflects the red light ray LR toward the illumination optical axis AX.

[0137] The first dichroic mirror 74 is disposed at 45° with respect to the illumination optical axis AX, and is composed of a dielectric multilayer film having an optical characteristic of reflecting blue band light and transmitting light of other bands. The second dichroic mirror 73 is disposed at 45° with respect to the illumination optical axis AX and orthogonal to the first dichroic mirror 74, and is composed of a dielectric multilayer film having an optical characteristic of reflecting red band light and transmitting light of other bands.

[0138] The first dichroic mirror 74 is disposed opposite to the first mirror 71, and reflects the blue light ray LB after being reflected by the first mirror 71 toward the direction along the illumination optical axis AX. The second dichroic mirror 73 is disposed opposite to the second mirror 72, and reflects the red light ray LR after being reflected by the second mirror 72 toward the direction along the illumination optical axis AX. The green light ray LG emitted from the green light emitting section 10G of the light source section 10 transmits the first dichroic mirror 74 and the second dichroic mirror 73, and travels along the illumination optical axis AX.

[0139] According to such a configuration, the beam width reducing optical system 70 can reduce the beam width of the illumination light L by overlapping the chief rays of the blue light ray LB, the green light ray LG, and the red light ray LR with the illumination optical axis AX.

[0140] In this embodiment, the short sides of the blue ray LB, green ray LG, and red ray LR that have passed through the beam width reduction optical system 70 are also along the Z-axis direction.

[0141] The optical amplification system 200 of this embodiment includes a cylindrical lens 210 and a parallel lens 220. The cylindrical lens 210 has the same structure as the first cylindrical lens 21 of the first embodiment. That is, the cylindrical lens 210 has a plurality of lenses 210a composed of cylindrical convex lenses that have positive refractive power in the Z-axis direction and no refractive power in the Y-axis direction. Therefore, the cylindrical lens 210 amplifies the illumination light L incident from the light source 10 by diffusing it in the Z-axis direction.

[0142] The parallelizing lens 220 is composed of a convex lens. For example... Figure 10 As shown, the parallelizing lens 220 parallelizes the light emitted from the cylindrical lens 210 in the Z-axis direction.

[0143] like Figure 11 As shown, the cylindrical lens 210 allows the illumination light L incident from the light source 10 to pass through without changing its direction of travel in the Y-axis direction, which does not have the refractive power of a lens. The illumination light L that has passed through the cylindrical lens 210 in the Y-axis direction is focused by the parallelizing lens 220 onto the image forming region 2a or its vicinity in the light modulation device 2.

[0144] In this way, the optical amplification system 200 of this embodiment diffuses the illumination light L emitted from the light source 10 in the Z-axis direction, generating a rectangular amplified illumination light WL extending in the Z-axis direction.

[0145] Furthermore, the rate of change (diffusion degree) of the beam width in the Z-axis direction of the optical amplification optical system 200 can be adjusted, for example, by adjusting the optical properties such as the curvature and refractive index of each lens constituting the cylindrical lens 210.

[0146] In the optical amplification system 200 of this embodiment, by spreading the various colored light rays LB, LG, LR emitted from the light source 10 in the Z-axis direction along the short side, it is also possible to generate amplified illumination light WL with low light density suppression.

[0147] In the light source device 101 of this embodiment, the light amplification direction (Z-axis direction) of the light amplification optical system 200 for the amplified illumination light WL is aligned with the short-side direction of the light rays LB, LG, and LR incident on the light amplification optical system 200. That is, the light amplification optical system 200 does not diffuse the light rays LB, LG, and LR in the long-side direction, but rather diffuses them in the short-side direction to generate the amplified illumination light WL. Therefore, the optical density of the amplified illumination light WL can be suppressed to a low level.

[0148] Further, the light amplification optical system 200 of the present embodiment makes the amplified illumination light WL parallel by the parallelization lens 220 so as to be incident on the image formation region 2a of the light modulation device 2, and thus, compared to the first embodiment, the superposition optical system 30 and the field lens 50 can be removed.

[0149] In the light amplification optical system 200 of the present embodiment, the parallelization lens 220 is composed of a convex lens. That is, the parallelization lens 220 has a lens power in the Y-axis direction as well, but the structure of the parallelization lens is not limited thereto. For example, the parallelization lens can also be composed of a cylindrical convex lens having a positive power in the Z-axis direction and no power in the Y-axis direction.

[0150] Further, the technical scope of the present application is not limited to the above-described embodiments, and various modifications can be made thereto without departing from the spirit of the present application.

[0151] Further, the specific description of the shape, number, arrangement, material, and the like of each constituent element of the light source device and the projector is not limited to the above-described embodiments, and can be appropriately changed.

[0152] For example, in the above-described embodiments and modified examples, a case where the light source section 10 emits each color light ray LB, LG, LR as illumination light L in time series is exemplified, but if it is applied to a projector for displaying a single color, a single color light ray can also be emitted from the light source section.

[0153] Hereinafter, a summary of the present disclosure is described.

[0154] (Summary 1)

[0155] A light source device includes a light source section that emits light including a first light ray, a light amplification optical system that generates amplified light obtained by amplifying the light along a first axis, and a light scanning section that causes the amplified light incident from the light amplification optical system to scan in a direction along a second axis orthogonal to the first axis in an illuminated region, a cross section of the first light ray based on a plane perpendicular to a chief ray is a shape having a long side and a short side, and the short side of the first light ray when incident on the light amplification optical system is along the first axis.

[0156] According to the light source device of this structure, the light emitted from the light source section can be converted into the amplified light that is a rectangle elongated along the first axis by the light amplification optical system. Further, in the case of the present structure, the light amplification optical system diffuses the light in the short side direction of the first light ray to generate the amplified light, and thus, the optical density of the amplified light can be suppressed to be low. Therefore, the light scanning section can suppress damage caused by heat and illuminate the entire region of the illuminated region.

[0157] (Summary 2)

[0158] The light source device according to the supplementary note 1, wherein the light emitted from the light source section further includes second light rays, the first light rays and the second light rays are arranged in a direction along the second axis, a cross section of the second light rays based on a plane perpendicular to a chief ray is a shape having a long side and a short side, and the short side of the second light rays is along the first axis.

[0159] According to this structure, even in a case where the light source section amplifies light including the first light rays and the second light rays, the amplified light is diffused in the short side direction of the first light rays and the second light rays, and thus it is possible to suppress the optical density of the amplified light to be low.

[0160] (Supplementary Note 3)

[0161] The light source device according to the supplementary note 1 or 2, further comprising an overlapping optical system that overlaps the amplified light emitted from the light amplification optical system with the illuminated region, the light amplification optical system having a first cylindrical lens that divides the light into a plurality of light beams, and a second cylindrical lens that causes the plurality of light beams divided by the first cylindrical lens to be incident on the overlapping optical system.

[0162] According to this structure, by using the light amplification optical system composed of the first cylindrical lens and the second cylindrical lens, the amplified illumination light extending along the first axis is generated, and it is possible to efficiently illuminate the illuminated region by the overlapping optical system.

[0163] (Supplementary Note 4)

[0164] The light source device according to the supplementary note 3, wherein the first cylindrical lens includes a first base material and a plurality of first lenses provided to the first base material, and the second cylindrical lens includes a second base material and a plurality of second lenses provided to the second base material.

[0165] According to this structure, the first cylindrical lens and the second cylindrical lens are separate, and thus the manufacture of the lenses becomes easy.

[0166] (Supplementary Note 5)

[0167] The light source device according to the supplementary note 3, wherein the light amplification optical system further has a base material provided with the first cylindrical lens on a first surface side and provided with the second cylindrical lens on a second surface side opposite to the first surface.

[0168] According to this structure, the first cylindrical lens and the second cylindrical lens are a single lens, and thus the alignment of the first cylindrical lens and the second cylindrical lens is not required. Thus, it is possible to simplify the assembly process of the light amplification optical system.

[0169] (Supplementary Note 6)

[0170] The light source device according to any one of the above 1 or 2, wherein the light amplification optical system has a cylindrical lens that amplifies the light along the second axis, and a parallelization lens that parallelizes the light emitted from the cylindrical lens in a direction along the second axis.

[0171] According to this structure, by using the light amplification optical system composed of the cylindrical lens and the parallelization lens, it is possible to generate the amplified illumination light extending along the first axis.

[0172] (Paragraph 7)

[0173] The light source device according to any one of the above 1 to 6, further comprising a field lens that deflects the light incident from the light scanning section.

[0174] According to this structure, the light scanning section can efficiently illuminate the illuminated region with the amplified light.

[0175] (Paragraph 8)

[0176] The light source device according to the above 2, wherein the light emitted from the light source section further includes a third light ray that is juxtaposed with the first light ray or the second light ray in a direction along the first axis, a cross section of the third light ray based on a plane perpendicular to the chief ray is a shape having a long side and a short side, and the short side of the third light ray is along the first axis.

[0177] According to this structure, even in the case where the light source section emits the light including the three light rays arranged in the two directions of the first axis and the second axis, it is possible to suppress the optical density of the amplified light to be low by diffusing the light in the short side direction of the first light ray, the second light ray, and the third light ray.

[0178] (Paragraph 9)

[0179] The light source device according to the above 8, wherein the first light ray, the second light ray, and the third light ray are different color lights from each other, and the light source section emits the first light ray, the second light ray, and the third light ray in time series.

[0180] According to this structure, it is possible to change the color of the light emitted from the light source device in time series.

[0181] (Paragraph 10)

[0182] The light source device according to any one of the above 1 to 9, wherein an aspect ratio of a cross section of the first light ray is 3 times or more.

[0183] According to this configuration, by using a light source section that emits light containing a first light ray having an aspect ratio of three or more, the effect of suppressing the light density of the amplified light can be further improved.

[0184] (Embodiment 11)

[0185] The light source device according to any one of Embodiments 1 to 10, wherein a long side direction of an aspect ratio of a cross section of the light emitted from the light source section is a direction along the second axis, and a long side direction of an aspect ratio of a cross section of the amplified light emitted from the light amplification optical system is a direction along the first axis.

[0186] According to this configuration, light having a long side in the second axis direction can be amplified in the first axis direction, and amplified light having a long side in the Z axis direction can be favorably generated.

[0187] (Embodiment 12)

[0188] A projector including the light source device according to any one of Embodiments 1 to 11, a light modulation device that modulates light incident from the light source device, and a projection optical device that projects light modulated by the light modulation device.

[0189] According to this configuration, the amplified light emitted from the light source device scans the image formation region of the light modulation device, and thus a bright image can be projected. Furthermore, since the light density of the amplified light is suppressed, damage caused by heat in the light modulation device is suppressed, and the reliability of the projector can be further improved.

[0190] (Embodiment 13)

[0191] A projector including the light source device according to any one of Embodiments 3 to 5, a light modulation device that optically modulates light incident from the light source device in accordance with image information, and a projection optical device that projects light modulated by the light modulation device, the light modulation device having an image formation region that generates image light, wherein, when the lens pitch of the first cylindrical lens and the second cylindrical lens is a, the lens pitch distance of the first cylindrical lens and the second cylindrical lens is b, and the distance between the overlap optical system and the light modulation device is b1, the size S in the direction along the amplification direction of the amplified light in the image formation region satisfies the following relationship:

[0192] S < (a x b1 / b) - 1.0.

[0193] According to this configuration, even in the case of a mounting deviation of an optical member or a difference in precision of a cylindrical lens, the image formation region of the light modulation device can be favorably illuminated with light from the light source device.

[0194] (Note 14)

[0195] A projector having the light source device according to any one of Note 3 to Note 5, a light modulation device that modulates light incident from the light source device according to image information, and a projection optical device that projects light modulated by the light modulation device, the light modulation device having an image formation region, the light source portion of the light source device including a light emitting element that emits the first light, and a collimator lens that collimates the first light emitted from the light emitting element, when a dimension of the light emitting element in a direction along the first axis in a light emitting region is c, a focal length of the collimator lens is d, and a distance between the superposition optical system and the light modulation device is d1, a dimension S1 of the image formation region in the direction along the first axis satisfies the following relationship:

[0196] S1 > 2 x c x d1 / d.

[0197] According to this structure, heat generation of the image formation region can be suppressed, and light from the light source device can be efficiently incident to the image formation region.

Claims

1. A light source device, comprising: The light source emits light containing the first ray; An optical amplification system that generates amplified light by amplifying the light along a first axis; and The optical scanning unit causes the amplified light incident from the optical amplification system to scan the illuminated area in a direction along a second axis orthogonal to the first axis. The first ray has a cross-section based on a plane perpendicular to the principal ray, which has a long side and a short side. The short side of the first ray incident on the optical amplification system is along the first axis.

2. The light source device according to claim 1, wherein, The light emitted by the light source also includes a second ray. The first ray and the second ray are aligned along the second axis. The cross-section of the second ray, based on a plane perpendicular to the principal ray, has a shape with a long side and a short side. The shorter side of the second ray is along the first axis.

3. The light source device according to claim 1, wherein, The light source device also has an overlapping optical system that causes the amplified light emitted from the optical amplification optical system to overlap with the illuminated area. The optical amplification system includes: a first cylindrical lens that splits the light into multiple beams; And a second cylindrical lens, which causes the plurality of beams split by the first cylindrical lens to be incident on the overlapping optical system.

4. The light source device according to claim 3, wherein, The first cylindrical lens includes a first substrate and a plurality of first lenses disposed on the first substrate. The second cylindrical lens includes a second substrate and a plurality of second lenses disposed on the second substrate.

5. The light source device according to claim 3, wherein, The optical amplification system further comprises a substrate having the first cylindrical lens disposed on a first surface and the second cylindrical lens disposed on a second surface opposite to the first surface.

6. The light source device according to claim 1, wherein, The optical amplification system includes: a cylindrical lens that amplifies the light along the first axis; and a parallelizing lens that parallelizes the light emitted from the cylindrical lens in the direction along the first axis.

7. The light source device according to claim 1, wherein, The light source device also includes a field lens that deflects light incident from the light scanning section.

8. The light source device according to claim 2, wherein, The light emitted by the light source also includes a third ray, which is parallel to the first ray or the second ray in a direction along the first axis. The cross-section of the third ray, based on a plane perpendicular to the principal ray, has a shape with a long side and a short side. The short side of the third ray is along the first axis.

9. The light source device according to claim 8, wherein, The first ray, the second ray, and the third ray are different colors of light, and the light source emits the first ray, the second ray, and the third ray in chronological order.

10. The light source device according to any one of claims 1 to 9, wherein, The aspect ratio of the cross section of the first ray is more than 3.

11. The light source device according to any one of claims 1 to 9, wherein, The aspect ratio of the cross-section of the light emitted from the light source is such that the long side is along the second axis. The aspect ratio of the cross section of the amplified light emitted from the optical amplification system has its long side along the first axis.

12. A projector comprising: The light source device according to any one of claims 1-9; An optical modulation device that modulates light incident from the light source device; and A projection optical device that projects light modulated by the light modulation device.

13. A projector comprising: The light source device according to any one of claims 3-5; An optical modulation device that modulates light incident from the light source device according to image information; and A projection optical device that projects light modulated by the light modulation device. The optical modulation device has an image forming region for generating image light. When the lens spacing between the first and second cylindrical lenses is a, the lens distance between the first and second cylindrical lenses is b, and the distance between the overlapping optical system and the optical modulation device is b1, The dimension S of the image forming region along the magnification direction of the magnified light satisfies the following relationship: S < (a × b1 / b) - 1.

0.

14. A projector comprising: The light source device according to any one of claims 3-5; A light modulation device that modulates light incident from the light source device according to image information; and A projection optical device that projects light modulated by the light modulation device. The optical modulation device has an image forming area. The light source unit of the light source device includes: a light-emitting element that emits the first light ray; and a collimating lens that parallelizes the first light ray emitted from the light-emitting element. Let the dimension along the second axis in the light-emitting region of the light-emitting element be c, the focal length of the collimating lens be d, and the distance between the overlapping optical system and the light modulation device be d1. The dimension S1 of the image forming region along the second axis satisfies the following relationship: S1>2×c×d1 / d.

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