Light source device and projector

Abstract

A light source device and a projector. Provided are a light source device capable of generating rectangular illumination light extending in a direction perpendicular to a scanning direction, and a projector. This light source device is provided with: a light source unit that emits light including a first light beam and a second light beam arranged in a direction along a first axis in a direction intersecting the first axis; a light amplification optical system that generates amplified light obtained by amplifying the light in a direction along a second axis perpendicular to the 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 light incident from the overlapping optical system over the region to be illuminated in a direction 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 is proposed which illuminates a light modulation device such as a liquid crystal panel by causing light emitted from an optical element to scan over time on the light modulation device. A projector is disclosed in Patent Literature 1 below which has 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.

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

[0004] In the projector of Patent Literature 1, the polygon mirror reflects and condenses light emitted from the light source device on the liquid crystal light valve, so it is difficult to generate a rectangular illumination light extending in a direction perpendicular to the scanning direction well with respect to the liquid crystal light valve. 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 which emits light including a first light ray and a second light ray arranged in a direction along a first axis, in a direction intersecting the first axis; a light amplification optical system which generates amplified light obtained by amplifying the light in a direction along a second axis perpendicular to the first axis; an overlapping optical system which overlaps the amplified light emitted from the light amplification optical system with an illuminated region; and a light scanning section which scans light incident from the overlapping optical system on the illuminated region in a direction along the first axis.

[0006] Further, according to a second aspect of the present application, there is provided a light source device including: a light source section which emits light including a plurality of light rays emitted from a light emitting point on the same plane; a first cylindrical lens and a second cylindrical lens which generate amplified light obtained by amplifying the light in a direction along a third axis; an overlapping optical system which overlaps the amplified light with an illuminated region; and a light scanning section which scans the amplified light emitted from the overlapping optical system in a direction along a fourth axis perpendicular to the third axis.

[0007] According to a third aspect of the present application, there is provided a projector including: the light source device of the first aspect or the second aspect; a light modulation device which modulates light incident from the light source device according to image information; and a projection optical device which projects light modulated by the light modulation device. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1is a plan view showing the schematic configuration of the projector as viewed from the +Y side.

[0009] Figure 2 is a plan view showing the schematic configuration of the projector as viewed from the +Z side.

[0010] Figure 3 is a diagram showing the relationship established between the optical components when viewed in the Y-axis direction.

[0011] Figure 4A is an explanatory diagram of the behavior of blue light when the transmissive optical element is rotated.

[0012] Figure 4B is an explanatory diagram of the behavior of blue light when the transmissive optical element is rotated.

[0013] Figure 4C is an explanatory diagram of the behavior of blue light when the transmissive optical element is rotated.

[0014] Figure 4D is an explanatory diagram of the behavior of blue light when the transmissive optical element is rotated.

[0015] Figure 4E is an explanatory diagram of the behavior of blue light when the transmissive optical element is rotated.

[0016] Figure 5 is a diagram showing the behavior of light that passes through the transmissive optical element at the time of color switching.

[0017] Figure 6 is a diagram showing the relationship established between the optical components when viewed in the Z-axis direction.

[0018] Figure 7 is a plan view showing the schematic configuration of the light amplification optical system of the first modified example as viewed from the +Y side.

[0019] Figure 8 is a perspective view showing the main part of the light source section of the second modified example.

[0020] BRIEF DESCRIPTION OF THE DRAWINGS

[0021] 1: light source device; 2: light modulation device; 2a: image forming region; 4: projection optical device; 10, 210: light source portion; 11: light emitting region; 20, 120: light amplification optical system; 21, 121: 1st cylindrical lens; 21a: 1st lens; 21b: 1st base material; 22, 122: 2nd cylindrical lens; 22a: 2nd lens; 22b: 2nd base material; 30: superposition optical system; 40: light scanning portion; 130a: 1st surface; 130b: 2nd surface; 50: field lens; 100: projector; 10B1: light emitting element; 10B2: collimator lens; 130: base material; LB: blue light (1st light); LG: green light (2nd light); LR1: red light (1st light); LR2: red light (3rd light). DETAILED DESCRIPTION

[0022] Hereinafter, an embodiment of the present application will be described using the drawings.

[0023] The projector of the present embodiment is an example of a liquid crystal projector using a liquid crystal panel as a light modulation device.

[0024] In the following respective drawings, in order to easily observe respective structural elements, the scale of the size is sometimes shown to be different according to the structural elements. In the following drawings, XYZ orthogonal coordinate system is used for explanation as necessary. The X axis is an axis parallel to the illumination optical axis of the light source device. The illumination optical axis is defined as an axis along the chief ray of the illumination light emitted from the light source device. The Z axis is an axis perpendicular to the X axis, and is an axis along the rotation axis O of the transmission optical element 41. The Y axis is an axis perpendicular to the X axis and the Z axis. The Y axis of the present embodiment corresponds to an example of the "1st axis" of the present application, and the Z axis of the present embodiment corresponds to an example of the "2nd axis" of the present application.

[0025] Hereinafter, in explaining the structure and arrangement of respective components, one side (+X side) and the other side (-X side) in the direction along the X axis are collectively referred to as the "X axis direction", one side (+Y side) and the other side (-Y side) in the direction along the Y axis are collectively referred to as the "Y axis direction", and one side (+Z side) and the other side (-Z side) in the direction along the Z axis are collectively referred to as the "Z axis direction".

[0026] Figure 1 is a plan view showing the schematic structure of the projector of the present embodiment as viewed from the +Y side.

[0027] Figure 2 is a plan view showing the schematic structure of the projector of the present embodiment as viewed from the +Z side.

[0028] As Figure 1 and Figure 2As shown, the projector 100 of the present embodiment includes 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.

[0029] The light source device 1 includes 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.

[0030] 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 configured by one package. Alternatively, the blue light emitting section 10B, the green light emitting section 10G, and the red light emitting section 10R can be configured by independent packages.

[0031] The blue light emitting section 10B includes a light emitting element 10B1, which is a laser diode that emits blue light rays LB, and a collimator lens 10B2 that makes the blue light rays LB parallel. The blue light rays LB are, for example, laser light having a blue wavelength band of 450 nm ± 5 nm.

[0032] The green light emitting section 10G includes a light emitting element 10G1, which is a laser diode that emits green light rays LG, and a collimator lens 10G2 that makes the green light rays LG parallel. The green light rays LG are, for example, laser light having a green wavelength band of 530 nm ± 5 nm.

[0033] The red light emitting section 10R includes a light emitting element 10R1, which is a laser diode that emits red light rays LR, and a collimator lens 10R2 that makes the red light rays LR parallel. The red light rays LR are, for example, laser light having a red wavelength band of 650 nm ± 5 nm.

[0034] In the present embodiment, the cross-sectional shape of each of the color light rays LB, LG, and LR emitted by the light source section 10, which is perpendicular to the chief ray, is, for example, substantially square.

[0035] The light emitting surfaces of the light emitting elements 10B1, 10G1, and 10R1 of the respective light emitting sections 10B, 10G, and 10R are arranged on the same plane. That is, the light source section 10 of the present embodiment emits illumination light L that includes a plurality of each color light rays LB, LG, and LR emitted from light emitting points on the same plane.

[0036] In the present embodiment, the blue light rays LB correspond to an example of the "first light rays" of the present application, and the green light rays LG correspond to an example of the "second light rays" of the present application.

[0037] Based on 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 in time series to the light amplifying optical system 20. Therefore, the illumination light L emitted from 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 from 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.

[0038] 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 rectangular-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.

[0039] The light amplifying optical system 20 of the present embodiment has a first lenticular lens 21 and a second lenticular lens 22. In the present embodiment, the first lenticular lens 21 and the second lenticular lens 22 are separate lenses, and thus the manufacture of the lenses becomes easy.

[0040] The first lenticular lens 21 and the second lenticular lens 22 have the same shape. Therefore, the lens pitch of the first lenticular lens 21 and the second lenticular lens 22 is equal.

[0041] The first lenticular lens 21 includes a first base material 21b which is a flat plate-shaped light-transmissive substrate, 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 of the first lenses 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 of the first lenses 21a divides the illumination light L incident from the light source section 10 into a plurality of light beams in the Z-axis direction. Each of the light beams is diffused in the Z-axis direction having lens power.

[0042] The second lenticular lens 22 includes a second base material 22b which is a flat plate-shaped light-transmissive substrate, 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 lenticular lens 21. Each of the second lenses 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.

[0043] The second cylindrical lens 22, together with the superimposition optical system 30 of the subsequent stage, causes the image of each first lens 21a of the first cylindrical lens 21 to be imaged in the vicinity of the image formation region 2a of the light modulation device 2, which is the illuminated region, or the like in the Z-axis direction having the lens power.

[0044] The first cylindrical lens 21 and the second cylindrical lens 22 cause the traveling direction of the illumination light L incident from the light source section 10 to be transmitted without change in the Y-axis direction not having the lens power. The illumination light L transmitted through the first cylindrical lens 21 and the second cylindrical lens 22 in the Y-axis direction is condensed on the image formation region 2a of the light modulation device 2 or the like by the superimposition optical system 30.

[0045] Thus, the light amplification optical system 20 of the present embodiment causes the illumination light L emitted from the light source section 10 to diverge in the Z-axis direction, and generates the rectangularly shaped amplified illumination light WL extending in the Z-axis direction.

[0046] Further, for example, the rate of change (degree of divergence) of the beam width in the Z-axis direction in the light amplification optical system 20 can be adjusted 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.

[0047] The light scanning section 40 causes the amplified illumination light WL incident from the light amplification optical system 20 to scan in the illuminated region in the Y-axis direction. Specifically, the light scanning section 40 causes the band-shaped amplified illumination light WL extending in the Z-axis direction to scan 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 causing the band-shaped amplified illumination light WL to scan 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.

[0048] 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.

[0049] In the present embodiment, the light scanning section 40 causes the amplified illumination light WL incident from the superimposition optical system 30 to scan in the Y-axis direction on the image formation region 2a of the light modulation device 2.

[0050] The light scanning section 40 has a transmissive optical element 41 and a rotational driving section 45.

[0051] The transmission optical element 41 is composed of a light-transmissive member supported so as to be rotatable. The transmission optical element 41 is rotatable about a rotation axis O extending in the Z-axis direction. The transmission optical element 41 is coupled to a rotation drive section 45 composed of a motor or the like. The transmission optical element 41 is rotated about the rotation axis O by driving of the rotation drive section 45.

[0052] 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 perpendicularly connected to the surface 41a and the back surface 41b. That is, the transmission optical element 41 has a shape of a right 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 cut with a plane perpendicular to the rotation axis O is a square. That is, the four side surfaces 41c have the same area, and two of the side surfaces opposite to each other are parallel to each other. The rotation axis O coincides with the center of the square transmission optical element 41.

[0053] The transmission optical element 41 transmits the enlarged illumination light WL emitted from the light enlargement optical system 20 while rotating about the rotation axis O. Therefore, the side surface on which the enlarged illumination light WL emitted from the light enlargement optical system 20 is incident on the transmission optical element 41 is not determined to be one, but varies with time. Similarly, the side surface on which the enlarged illumination light WL incident on the transmission optical element 41 is emitted to the outside is not determined to be one, but varies with time. In the transmission optical element 41, the side surface on which the enlarged illumination light WL emitted from the light enlargement optical system 20 is incident is referred to as an "incident surface". The side surface on which the enlarged illumination light WL incident on 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 of the four side surfaces 41c which are parallel to each other.

[0054] In the present specification, in the case where two surfaces of the transmission optical element 41 are parallel to each other, the case where the angle formed by the two surfaces is within the range of 0 ± 5 degrees is referred to as "parallel" in consideration of the machining accuracy of the glass material constituting the light-transmissive member, the allowable range of parallelism of light, and the like.

[0055] In 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 is a natural number of two 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 surfaces opposite thereto, and there is no side surface which is not parallel. Thus, the generation of stray light in the transmission optical element 41 is less, and the light use efficiency can be improved.

[0056] The light modulating device 2 is provided 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.

[0057] Here, it is preferable that the size in the Z-axis direction of the magnified illumination light WL (the magnification direction of the magnified illumination light WL) that illuminates the image forming region 2a of the light modulating device 2 be set to be slightly larger than the size of the image forming region 2a of the light modulating device 2. The present inventors have obtained the following insight based on simulation: it is preferable that the size of the magnified illumination light WL be expanded by 0.5 mm or more to the outside.

[0058] 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 observation of the view.

[0059] 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 in the Z-axis direction of the magnified illumination light WL is set to a1, the lens interval 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.

[0060] The light emitted from the first lens 21a of the first cylindrical lens 21 is parallelized at the second lens 22a of the second cylindrical lens 22, and is imaged on the image forming region 2a of the light modulating device 2 by the superposition optical system 30. Therefore, for the lens pitch a, the beam width a1, the lens interval distance b, and the distance b1 described above, the relationship a:a1=b:b1 is established. Therefore, the beam width a1 is defined by a1=a×b1 / b.

[0061] As described above, it is preferable that the beam width in the Z-axis direction of the magnified illumination light WL be considered to have a margin of 1.0 mm or more on both sides. Therefore, when the margin of the magnified illumination light WL is considered, the size S in the Z-axis direction of the image forming region 2a satisfies the relationship of the following equation (1).

[0062] S<(a×b1 / b)-1.0 Equation (1)

[0063] If the above formula (1) is satisfied, even in the case where the installation deviation of the optical member, the precision difference of the cylindrical lens is large, the magnified illumination light WL can be well illuminated on the image forming region 2a of the light modulation device 2.

[0064] The incident-side polarizing plate 3a is disposed on the light incident side of the light modulation device 2 on the illumination light axis AX. The emission-side polarizing plate 3b is disposed on the light emission side of the light modulation 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 perpendicular to each other.

[0065] The incident-side polarizing plate 3a transmits the linearly polarized component in a specific direction in the magnified illumination light WL emitted from the light source section 10 to the light modulation device 2. The emission-side polarizing plate 3b transmits the linearly polarized light in the specific direction emitted from the light modulation device 2 to 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 transmitted through the light-transmissive member increases, the amount of light 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 is disturbed, and the linearly polarized light incident to 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 is disturbed, the linearly polarized component in the specific direction can be made to be incident to the light modulation device 2.

[0066] Further, 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, since the disturbance of the polarization direction is less likely to occur, the incident-side polarizing plate 3a provided on the light incident side of the light modulation device 2 can also be omitted.

[0067] The projection optical device 4 is constituted by a plurality of projection lenses. The projection optical device 4 magnifies and projects the image light modulated by the light modulation device 2 to a projection surface such as a screen.

[0068] Thus, an image is displayed on the projection surface.

[0069] Hereinafter, the behavior of the magnified illumination light WL when it transmits through the transmission optical element 41 will be described in detail. Further, since the behaviors of the respective color light rays LB, LG, LR included in the magnified illumination light WL are the same, the behavior of the blue light ray LB and the behavior at the time of switching from the blue light ray LB to the green light ray LG will be described below.

[0070] Figures 4A to 4Eis a diagram for illustrating the behavior 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 about the rotation axis O, and the blue light ray LB is incident on the transmission optical element 41. Figure 4A is a diagram for illustrating the behavior 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 about the rotation axis O, and the blue light ray LB is incident on the transmission optical element 41. Figure 4E is a diagram for illustrating the behavior 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 about the rotation axis O, and the blue light ray LB is incident on the transmission optical element 41. Figures 4A to 4E is a diagram for illustrating the behavior 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 about the rotation axis O, and the blue light ray LB is incident on the transmission optical element 41.

[0071] is a diagram for illustrating the behavior 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 about the rotation axis O, and the blue light ray LB is incident on the transmission optical element 41. Figures 4A to 4E is a diagram for illustrating the behavior 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 about the rotation axis O, and the blue light ray LB is incident on the transmission optical element 41.

[0072] Figures 4A to 4E is a diagram for illustrating the behavior 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 about the rotation axis O, and the blue light ray LB is incident on the transmission optical element 41.

[0073] Figure 4A is a diagram for illustrating the behavior 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 about the rotation axis O, and the blue light ray LB is incident on the transmission optical element 41. Figure 4A is a diagram for illustrating the behavior 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 about the rotation axis O, and the blue light ray LB is incident on the transmission optical element 41.

[0074] is a diagram for illustrating the behavior 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 about the rotation axis O, and the blue light ray LB is incident on the transmission optical element 41.

[0075] is a diagram for illustrating the behavior 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 about the rotation axis O, and the blue light ray LB is incident on the transmission optical element 41. Figure 4B ​As shown, when the rotation angle ω of the transmission optical element 41 becomes more than Figure 4A 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 becomes smaller than that of the ray LB. Figure 4A The time is small. Furthermore, the state in which the blue ray LB travels parallel to the illumination optical axis AX is always maintained. During the rotation angle ω from 0 degrees to 45 degrees, the displacement m decreases monotonically with increasing rotation angle ω.

[0076] Therefore, the ratio of the blue light LB emitted from the transmission optical element 41 to the image forming region 2a of the light modulation device 2 is increased. Figure 4A The position is near the -Y side.

[0077] Next, as Figure 4C As shown, when the rotation angle ω of the transmission optical element 41 becomes more than... Figure 4B When the angle is greater than 45 degrees, the angle between the straight line M and the illumination optical axis AX becomes 45 degrees, 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, the blue light LB is incident perpendicularly to the side 41c2, so it does not refract at the side 41c2 and travels 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 does not refract at the side 41c4 and is emitted from the transmission optical element 41, traveling 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.

[0078] Next, as Figure 4D 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 towards the side 41c3, closer to the center of the side 41c2. At this time, the blue light LB is refracted at the side 41c2, but the direction of refraction is different from that at the center. Figure 4B The refraction occurs at different times, in the direction shown in the diagram (-Y side). Furthermore, the angle of refraction when the blue ray LB is incident on side 41c2 cancels out the angle of refraction when it exits from side 41c4. Figure 4B The same period applies. As a result, the blue ray LB travels parallel to the illumination axis AX at a position where it is 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.

[0079] Thus, the blue light LB emitted from the transmission optical element 41 is incident on the image forming area 2a of the light modulation device 2 at a position closer to the -Y side than the center.

[0080] Next, as shown in Figure 4E the rotation angle ω of the transmission optical element 41 becomes the maximum, the state in which the blue light LB travels in parallel with the illumination optical axis AX is maintained, and the displacement amount m becomes the maximum.

[0081] Thus, the blue light LB emitted from the transmission optical element 41 is incident on the end portion 2a2 of the image formation region 2a of the light modulation device 2 on the -Y side as an illuminated region.

[0082] Thus, the blue light LB incident on the side surface 41c2 of the rotating transmission optical element 41 can scan the image formation region 2a of the light modulation device 2 in the Y-axis direction.

[0083] In Figure 4E the state shown in Figure 4E , 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 , the light source portion 10 switches the emitted illumination light L from the blue light LB to the green light LG.

[0084] Figure 5 is a view showing the behavior of the light passing through the transmission optical element 41 at the time of switching from the blue light LB to the green light LG.

[0085] As shown in Figure 5 , 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 on 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 on both ends in the Y-axis direction of the image formation region 2a, respectively, different color lights are incident on the same region (both ends in the Y-axis direction) of the image formation region 2a in time series, resulting in a quality reduction of the projection image caused by color mixing.

[0086] In contrast, in the projector 100 of the present embodiment, the size of the image formation region 2a is set so 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 incident on the outside of the image formation region 2a. Thus, it is possible to suppress the generation of color mixing.

[0087] However, if the beam width of the illumination light L emitted from the light source section 10 in the Y-axis direction is increased all the time, 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.

[0088] The present inventors believe that if the beam width of the illumination light L is too thin, the image formation region 2a is locally heated, and, on the contrary, if the beam width of the illumination light L is too thick, the utilization efficiency of the illumination light L in the image formation region 2a decreases as described above, and therefore the beam width of the illumination light L is preferably one-half or less of the image formation region 2a.

[0089] Figure 6 is a view showing the relationship established between the optical components when viewed in the Z-axis direction. In Figure 6 , 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 6 , the blue light emitting section 10B in the light source section 10 is illustrated.

[0090] In Figure 6 , the dimension of the light emitting element 10B1 of the blue light emitting section 10B in the Y-axis direction at the light emitting region 11 is denoted as c, the beam width of the magnified illumination light WL in the Y-axis direction is denoted as cl, the focal length of the collimator lens 10B2 of the blue light emitting section 10B is denoted as d, and the distance between the superposition optical system 30 and the light modulating device 2 is denoted as dl.

[0091] The blue light rays LB emitted from the light emitting region 11 of the light emitting element 10B1 are parallelized at the collimator lens 10B2. The first cylindrical lens 21 and the second cylindrical lens 22 do not have lens refractive power in the Y-axis direction, and therefore the blue light rays LB, which have been parallelized at the collimator lens 10B2, pass through the first cylindrical lens 21 and the second cylindrical lens 22. Thereafter, the blue light rays LB are imaged on the image formation region 2a of the light modulating device 2 by the superposition optical system 30. Therefore, for the dimension c of the light emitting region 11, the beam width cl, the focal length d, and the distance dl, the relationship c:cl = d:dl holds. Therefore, the beam width cl is defined by cl = c x dl / d.

[0092] As described above, the beam width of the magnified illumination light WL in the Y-axis direction is preferably one-half or less of the image formation region 2a in consideration of heating and a decrease in light utilization efficiency. 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 Expression (2).

[0093] S1 > 2 x c x dl / d Expression (2)

[0094] If the above formula (2) is satisfied, the heat generation of the image formation region can be suppressed, and the light of the light source device can be efficiently incident on the image formation region.

[0095] As described above, the light source device 1 of the present embodiment is provided with: the light source section 10 which emits the illumination light L containing the blue light ray LB, the green light ray LG, and the red light ray LR arranged in the Y-axis direction, along the Y-axis direction; the light amplification optical system 20 which generates the amplified illumination light WL which amplifies the illumination light L in the Z-axis direction; the superposition optical system 30 which superposes the amplified illumination light WL emitted from the light amplification optical system 20 with the image formation region 2a of the light modulation device 2 as an illuminated region; and the light scanning section 40 which scans the light incident from the superposition optical system 30 on the image formation region 2a in the Y-axis direction.

[0096] In other words, the light source device 1 of the present embodiment is provided with: the light source section 10 which emits the illumination light L containing a plurality of light rays LB, LG, LR emitted from light emitting points on the same plane; the first cylindrical lens 21 and the second cylindrical lens 22 which generate the amplified illumination light WL which amplifies the illumination light L in the direction along the Z-axis (the third axis); the superposition optical system 30 which superposes the amplified illumination light WL with the image formation region 2a of the light modulation device 2 as an illuminated region; and the light scanning section 40 which scans the amplified illumination light WL emitted from the superposition optical system 30 in the direction along the Y-axis (the fourth axis).

[0097] 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 which is rectangular in the Z-axis direction by the light amplification optical system 20. The amplified illumination light WL extends in the direction perpendicular to the light scanning direction of the light scanning section 40. Therefore, the light scanning section 40 can efficiently illuminate the entire region of the image formation region 2a of the light modulation device 2 with the amplified illumination light WL.

[0098] The light amplification optical system 20 of the present embodiment is composed of the first cylindrical lens 21 and the second cylindrical lens 22, and thus can easily generate the amplified illumination light WL which amplifies the illumination light L emitted from the light source section 10 in the uniaxial direction.

[0099] 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 formation region 2a of the light modulation device 2, and thus a bright image can be projected.

[0100] First Modified Example

[0101] Hereinafter, the first modified example of the above-described embodiment will be described.

[0102] The configuration of the light amplification optical system of this modification is different from that of the above-described embodiment. Furthermore, the same reference numerals are assigned to components common to the above-described embodiment, and the description is omitted with respect to details.

[0103] Figure 7 is a plan view showing the schematic configuration of the light amplification optical system 120 when viewed from the +Y side.

[0104] As shown in Figure 7 , the light amplification optical system 120 of this modification has a first columnar lens 121, a second columnar lens 122, and a base material 130. The base material 130 is a light-transmissive substrate, the first columnar lens 121 is provided on the +Y side of the first surface 130a, and the second columnar lens 122 is provided on the -Y side of the second surface 130b opposite to the first surface 130a. That is, in the light amplification optical system 120 of this modification, the first columnar lens 121 and the second columnar lens 122 are an integrated lens.

[0105] In the case of this modification, since the first columnar lens 121 and the second columnar lens 122 are an integrated lens, the alignment of the first columnar lens 121 and the second columnar lens 122 is not required. Therefore, according to the light source device using the light amplification optical system 120 of this modification, the assembly process can be simplified.

[0106] Second Modification

[0107] Hereinafter, the second modification of the above-described embodiment will be described.

[0108] The configuration of the light source section of this modification is different from that of the above-described embodiment. Furthermore, the same reference numerals are assigned to components common to the above-described embodiment, and the description is omitted with respect to details.

[0109] Figure 8 is a perspective view showing the main part of the light source section 210 of this modification.

[0110] As shown in Figure 8 , the light source section 210 of this modification includes a blue light emitting section 60B, a green light emitting section 60G, a first red light emitting section 60R, and a second red light emitting section 61R. The light source section 210 causes the blue light emitting section 60B, the green light emitting section 60G, the first red light emitting section 60R, and the second red light emitting section 61R to emit light at different timings, respectively.

[0111] The blue light emitting portion 60B has the same structure as the blue light emitting portion 10B of the first embodiment and emits blue light rays LB. The green light emitting portion 60G has the same structure as the green light emitting portion 10G of the first embodiment and emits green light rays LG. The first red light emitting portion 60R and the second red light emitting portion 61R have the same structure as the red light emitting portion 10R of the first embodiment and emit red light rays LR1 and LR2, respectively.

[0112] In the present modification, the blue light emitting portion 60B, the green light emitting portion 60G, and the first red light emitting portion 60R are arranged in order from the +Y side to the -Y side. The second red light emitting portion 61R is arranged in the Z-axis direction with the first red light emitting portion 60R.

[0113] That is, in the present modification, the illumination light L emitted from the light source portion 210 contains the blue light rays LB, the green light rays LG, and the red light rays LR1 arranged in the Y-axis direction, and the red light rays LR2 arranged in the Z-axis direction with the red light rays LR1. Therefore, in the case of the present modification, the beam width of the illumination light L emitted from the light source portion 210 in the Z-axis direction becomes large.

[0114] 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.

[0115] According to the light source portion 210 of the present modification, by increasing the number of red light rays LR, which is likely 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.

[0116] In the present modification, the case where the number of red light rays is two is exemplified, but the number of blue light rays and green light rays can also be increased by two each time. That is, it is possible to arrange two blue light emitting portions 60B in the Y-axis direction, or to arrange two green light emitting portions 60G in the Y-axis direction.

[0117] The light amplifying optical system 20 does not affect the beam width of the amplified illumination light WL in the Z-axis direction even in the case where the beam width of the illumination light L incident from the light source portion 210 in the Z-axis direction has changed. Therefore, according to the light source device of the present application, it is possible to generate the rectangular-shaped amplified illumination light WL that extends long in the Z-axis direction using the light amplifying optical system 20 regardless of the beam width of the illumination light L emitted from the light source portion 210.

[0118] Furthermore, the technical scope of the present application is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present application.

[0119] Further, the shape, number, arrangement, material, and the like of each structural element of the light source device and the projector are not limited to those described in the above embodiments and can be appropriately changed.

[0120] For example, in the above 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 the projector is applied to a case of displaying a single color, a single color light ray can be emitted from the light source section.

[0121] Hereinafter, a summary of the present disclosure is described.

[0122] Addendum 1

[0123] A light source device includes:

[0124] a light source section that emits light including a first light ray and a second light ray arranged in a direction along a first axis, in a direction intersecting the first axis;

[0125] a light amplification optical system that generates amplified light obtained by amplifying the light in a direction along a second axis perpendicular to the first axis;

[0126] an overlapping optical system that overlaps the amplified light emitted from the light amplification optical system with an illuminated region; and

[0127] a light scanning section that scans light incident from the overlapping optical system on the illuminated region in a direction along the first axis.

[0128] According to the light source device of this configuration, the light emitted from the light source section can be converted into rectangular amplified light extending in a direction along the second axis by the light amplification optical system. The amplified light extends in a direction perpendicular to the light scanning direction of the light scanning section. Therefore, the light scanning section can efficiently illuminate the entire region of the illuminated region with the amplified light.

[0129] Addendum 2

[0130] The light source device according to Addendum 1, wherein

[0131] the light amplification optical system has:

[0132] a first cylindrical lens that divides the light into a plurality of light beams; and

[0133] 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.

[0134] According to this configuration, by using the light amplification optical system composed of the first cylindrical lens and the second cylindrical lens, the amplified illumination light extending in the direction of the second axis can be well generated.

[0135] Note 3

[0136] The light source device according to Note 2, in which

[0137] The first cylindrical lens includes a first base material and a plurality of first lenses provided to the first base material,

[0138] The second cylindrical lens includes a second base material and a plurality of second lenses provided to the second base material.

[0139] According to this structure, the first cylindrical lens and the second cylindrical lens are separate bodies, and thus the manufacture of the lenses becomes easy.

[0140] Note 4

[0141] The light source device according to Note 2, in which

[0142] The light amplification optical system further has a base material that has the first cylindrical lens provided on a first surface side and has the second cylindrical lens provided on a second surface side opposite to the first surface.

[0143] According to this structure, the first cylindrical lens and the second cylindrical lens are one body, and thus the alignment of the first cylindrical lens and the second cylindrical lens is not necessary. Thus, the assembly process can be simplified.

[0144] Note 5

[0145] The light source device according to Note 1, further comprising a field lens that deflects light incident from the light scanning section.

[0146] According to this structure, the light scanning section can efficiently illuminate the illuminated region with the amplified light.

[0147] Note 6

[0148] The light source device according to Note 1, in which

[0149] The light emitted from the light source section further includes a third light ray arranged in a direction along the second axis with the first light ray or the second light ray.

[0150] According to this structure, even in the case where the light source section emits light including light rays arranged in both the first axis and the second axis, the amplified light extending in the direction along the second axis can be generated.

[0151] Note 7

[0152] The light source device according to Note 1, in which

[0153] The first light and the second light are different color lights, and the light source section emits the first light and the second light in time series.

[0154] According to this configuration, the color of light emitted from the light source device can be changed in time series.

[0155] Note 8

[0156] A light source device includes:

[0157] A light source section that emits light including a plurality of light rays emitted from a light emitting point on the same plane;

[0158] A first cylindrical lens and a second cylindrical lens that generate magnified light obtained by magnifying the light in a direction along a third axis;

[0159] An overlapping optical system that overlaps the magnified light with an illuminated region; and

[0160] A light scanning section that scans the magnified light emitted from the overlapping optical system in a direction along a fourth axis perpendicular to the third axis.

[0161] According to the light source device of this configuration, the light including a plurality of light rays emitted from a light emitting point on the same plane is converted into magnified light in a rectangular shape extending in a direction along a third axis by the first cylindrical lens and the second cylindrical lens. The magnified light extends in a direction perpendicular to the light scanning direction of the light scanning section, i.e., the fourth axis. Therefore, the light scanning section can efficiently illuminate the entire region of the illuminated region with the magnified light.

[0162] Note 9

[0163] A projector includes:

[0164] The light source device according to any one of Notes 1 to 8;

[0165] A light modulation device that modulates light incident from the light source device; and

[0166] A projection optical device that projects light modulated by the light modulation device.

[0167] According to the projector of this configuration, the magnified light emitted from the light source device scans the image forming region of the light modulation device, and thus a bright image can be projected.

[0168] Note 10

[0169] A projector includes:

[0170] The light source device according to any one of Note 2 to 4, Note 8;

[0171] a light modulating device that modulates light incident from the light source device according to image information; and

[0172] projection optical means that projects light modulated by the light modulating device,

[0173] the light modulating device has an image forming region that generates image light,

[0174] when a lens pitch of the first cylindrical lens and the second cylindrical lens is set to a, a lens pitch distance of the first cylindrical lens and the second cylindrical lens is set to b, and a distance between the overlapping optical system and the light modulating device is set to b1,

[0175] a size S of the image forming region in a direction along an amplification direction of the amplified light satisfies a relationship of the following equation:

[0176] S < (a x b1 / b) - 1.0.

[0177] According to this structure, even in a case where there is a mounting deviation of optical components or a precision difference of cylindrical lenses, light from the light source device can be used to perform good illumination on the image forming region of the light modulating device.

[0178] Addendum 11

[0179] A projector including:

[0180] the light source device according to any one of Addenda 1 to 10;

[0181] a light modulating device that modulates light incident from the light source device according to image information; and

[0182] projection optical means that projects light modulated by the light modulating device,

[0183] the light modulating device has an image forming region,

[0184] the light source portion of the light source device includes a light emitting element that emits the first light, and a collimator lens that makes the first light emitted from the light emitting element parallel,

[0185] when a size in a direction along the first axis at a light emitting region of the light emitting element is set to c, a focal length of the collimator lens is set to d, and a distance between the overlapping optical system and the light modulating device is set to d1,

[0186] a size S1 of the image forming region in a direction along the first axis satisfies a relationship of the following equation:

[0187] S1 > 2 x c x d1 / d.

[0188] According to this structure, it is possible to suppress heat generation in the image forming region, and efficiently cause light of the light source device to be incident on the image forming region.

Claims

1. A light source apparatus comprising: a light source section that emits light including first light and second light arranged in a direction along a first axis, in a direction intersecting the first axis; a light amplification optical system that generates amplified light obtained by amplifying the light in a direction along a second axis perpendicular to the first axis; an overlapping optical system that overlaps the amplified light emitted from the light amplification optical system with an illuminated region; and a light scanning section that scans light incident from the overlapping optical system on the illuminated region in a direction along the first axis.

2. The light source apparatus according to claim 1, wherein the light amplification optical system has: 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.

3. The light source apparatus according to claim 2, 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.

4. The light source apparatus according to claim 2, wherein the light amplification optical system further has a base material that has the first cylindrical lens provided on a first surface side and has the second cylindrical lens provided on a second surface side opposite to the first surface.

5. The light source apparatus according to claim 1, further comprising a field lens that deflects light incident from the light scanning section.

6. The light source apparatus according to claim 1, wherein the light emitted from the light source section further includes third light arranged in a direction along the second axis with the first light or the second light.

7. The light source apparatus according to claim 1, wherein the first light and the second light are different color lights, and the light source section emits the first light and the second light in time series.

8. A light source apparatus comprising: a light source section that emits light including a plurality of light rays emitted from light emitting points on the same plane; a first cylindrical lens and a second cylindrical lens that generate amplified light obtained by amplifying the light in a direction along a third axis; an overlapping optical system that overlaps the amplified light with an illuminated region; and a light scanning section that scans the amplified light emitted from the overlapping optical system in a direction along a fourth axis perpendicular to the third axis.

9. A projector comprising: the light source apparatus according to claim 1 or 8; a light modulation device that modulates light incident from the light source apparatus; and a projection optical device that projects light modulated by the light modulation device.

10. A projector comprising: the light source apparatus according to any one of claims 2 to 4 and 8; a light modulation device that modulates light incident from the light source apparatus 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 forming region, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ When a lens pitch of the first and second cylindrical lenses is set as a, a lens pitch distance of the first and second cylindrical lenses is set as b, and a distance between the superposition optical system and the light modulation device is set as b1, A size S of the image formation region in a direction along the magnification direction of the magnified light satisfies the following relationship: S < (a x b1 / b) - 1.

0.

11. A projector comprising: the light source device according to claim 1; 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 has an image formation region, the light source portion of the light source device includes a light emitting element that emits the first light, and a collimator lens that makes the first light emitted from the light emitting element parallel, when a size in a direction along the first axis at a light emitting region of the light emitting element is set as c, a focal distance of the collimator lens is set as d, and a distance between the superposition optical system and the light modulation device is set as d1, a size S1 of the image formation region in a direction along the first axis satisfies the following relationship: S1 > 2 x c x d1 / d.

Images