Light source device and projector

Abstract

To provide a light source device and a projector capable of generating rectangular illumination light extending in a direction orthogonal to a scanning direction.SOLUTION: The light source device according to the aspect of the invention includes the light source section adapted to emit the light including the first light beam and the second light beam arranged in the direction along the first axis toward the direction crossing the first axis, the light expansion optical system adapted to generate the expanded light obtained by expanding the light in the direction along the second axis perpendicular to the first axis, the superimposing optical system adapted to superimpose the expanded light emitted from the light expansion optical system on the illumination target area, and the light scanning section adapted to scan the light entering the light scanning section from the superimposing optical system on the illumination target area in the direction along the first axis.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] As a light source device for use in a projector, a light source device has been proposed that illuminates a light modulation device such as a liquid crystal panel by temporally scanning light emitted from an optical element on the light modulation device. Patent Document 1 listed below discloses a projector that includes a light source device including a light source lamp, a liquid crystal light valve, a polygon mirror provided between the light source device and the liquid crystal light valve, and a projection lens. [Prior art documents] [Patent documents]

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

[0004] In the projector of Patent Document 1, the polygon mirror reflects the light emitted from the light source device and focuses it onto the liquid crystal light valve, making it difficult to effectively generate rectangular illumination light that extends in a direction perpendicular to the scanning direction for the liquid crystal light valve. [Means for solving the problem]

[0005] In order to solve the above problem, according to a first aspect of the present invention, there is provided a light source device comprising: a light source unit that emits light including a first light ray and a second light ray aligned in a direction along a first axis in a direction intersecting the first axis; an optical expansion optical system that generates expanded light by expanding the light in a direction along a second axis perpendicular to the first axis; a superposition optical system that superimposes the expanded light emitted from the optical expansion optical system on an illuminated area; and an optical scanning unit that scans the light incident from the superposition optical system in a direction along the first axis on the illuminated area.

[0006] Furthermore, according to a second aspect of the present invention, there is provided a light source device comprising: a light source section that emits light including a plurality of light rays emitted from a light-emitting point on the same plane; a first lenticular lens and a second lenticular lens that generate magnified light by expanding the light in a direction along a third axis; a superposition optical system that superimposes the magnified light on an illuminated area; and a light scanning section that scans the magnified light emitted from the superposition optical system in a direction along a fourth axis perpendicular to the third axis.

[0007] According to a third aspect of the present invention, there is provided a projector comprising a light source device of the first or second aspect, a light modulation device that modulates light incident from the light source device in accordance with image information, and a projection optical device that projects the light modulated by the light modulation device. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a plan view showing a schematic configuration of the projector as viewed from the +Y side. [Figure 2] FIG. 2 is a plan view showing a schematic configuration of the projector as viewed from the +Z side. [Figure 3] 10 is a diagram showing the relationship between the optical members when viewed in a plane in the Y-axis direction. FIG. [Figure 4A] 10A and 10B are explanatory diagrams of the behavior of blue light rays when a transmissive optical element rotates. [Figure 4B] 10A and 10B are explanatory diagrams of the behavior of blue light rays when a transmissive optical element rotates. [Figure 4C] 10A and 10B are explanatory diagrams of the behavior of blue light rays when a transmissive optical element rotates. [Figure 4D] 10A and 10B are explanatory diagrams of the behavior of blue light rays when a transmissive optical element rotates. [Figure 4E] 10A and 10B are explanatory diagrams of the behavior of blue light rays when a transmissive optical element rotates. [Figure 5] 10A and 10B are diagrams illustrating the behavior of light passing through a transmissive optical element when switching colors. [Figure 6] 10 is a diagram showing the relationship between the optical members when viewed in a plane in the Z-axis direction. FIG. [Figure 7] FIG. 10 is a plan view showing a schematic configuration of the optical magnifying optical system of the first modified example as viewed from the +Y side. [Figure 8] FIG. 10 is a perspective view showing a main part of a light source unit of a second modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The projector of this embodiment is an example of a liquid crystal projector that uses a liquid crystal panel as a light modulation device. In the following drawings, the dimensions of some components may be shown at different scales to make them easier to see. In the following drawings, an XYZ Cartesian coordinate system will be used 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 the 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 transmissive optical element 41. The Y axis is an axis perpendicular to the X axis and Z axis. The Y axis in this embodiment corresponds to an example of the "first axis" in the present invention, and the Z axis in this embodiment corresponds to an example of the "second axis" in the present invention.

[0010] Hereinafter, when describing the configuration and arrangement of each component, one side (+X side) and the other side (-X side) along the X axis may be collectively referred to as the "X-axis direction," one side (+Y side) and the other side (-Y side) along the Y axis may be collectively referred to as the "Y-axis direction," and one side (+Z side) and the other side (-Z side) along the Z axis may be collectively referred to as the "Z-axis direction."

[0011] FIG. 1 is a plan view showing a schematic configuration of a projector according to this embodiment as viewed from the +Y side. FIG. 2 is a plan view showing a schematic configuration of the projector of this embodiment as viewed from the +Z side. As shown in FIGS. 1 and 2, a projector 100 of this embodiment includes a light source device 1, a light modulation device 2, an incident-side polarizing plate 3a, an exit-side polarizing plate 3b, and a projection optical device 4.

[0012] The light source device 1 includes a light source section 10, a light expanding optical system 20, a superimposing optical system 30, a light scanning section 40, and a field lens 50. The light source unit 10 includes a blue light-emitting unit 10B, a green light-emitting unit 10G, and a red light-emitting unit 10R. The light source unit 10 causes the blue light-emitting unit 10B, the green light-emitting unit 10G, and the red light-emitting unit 10R to emit light at different times. In the light source unit 10 of this embodiment, the blue light-emitting unit 10B, the green light-emitting unit 10G, and the red light-emitting unit 10R are configured in a single package structure. Alternatively, the blue light-emitting unit 10B, the green light-emitting unit 10G, and the red light-emitting unit 10R may have independent package structures.

[0013] Blue light-emitting unit 10B includes light-emitting element 10B1, which is a laser diode that emits blue light LB, and collimating lens 10B2 that collimates blue light LB. Blue light LB is, for example, laser light having a blue wavelength band of 450 nm±5 nm. Green light-emitting unit 10G includes light-emitting element 10G1, which is a laser diode that emits green light LG, and collimating lens 10G2 that collimates green light LG. Green light LG is, for example, laser light having a green wavelength band of 530 nm±5 nm. The red light emitter 10R includes a light emitting element 10R1 made of a laser diode that emits a red light beam LR, and a collimating lens 10R2 that collimates the red light beam LR. The red light beam LR is, for example, a laser beam having a red wavelength band of 650 nm±5 nm. In this embodiment, the cross-sectional shape perpendicular to the principal ray of each of the color light beams LB, LG, and LR emitted by the light source unit 10 is, for example, substantially square. The light-emitting surfaces of the light-emitting elements 10B1, 10G1, and 10R1 of the light-emitting units 10B, 10G, and 10R are arranged on the same plane. In other words, the light source unit 10 of this embodiment emits illumination light L including a plurality of color light rays LB, LG, and LR emitted from light-emitting points on the same plane.

[0014] In this embodiment, the blue light LB corresponds to an example of the "first light ray" of the present invention, and the green light LG corresponds to an example of the "second light ray" of the present invention.

[0015] Based on this configuration, the light source unit 10 of this embodiment emits illumination light L, which includes color light rays LB, LG, and LR emitted in time sequence, toward the optical magnification system 20. Therefore, the illumination light L emitted by the light source unit 10 is monochromatic light including any one of the color light rays LB, LG, and LR. In the illumination light L emitted by the light source unit 10, the blue light rays LB, green light rays LG, and red light rays LR are aligned in the Y-axis direction. In other words, the blue light rays LB, green light rays LG, and red light rays LR enter the optical magnification system 20 via different optical paths.

[0016] The optical magnification optical system 20 magnifies the illumination light L emitted from the light source unit 10 along the Z-axis direction to generate rectangular magnified illumination light WL extending along the Z-axis. The magnified illumination light WL in this embodiment corresponds to an example of the "magnified light" in the present invention.

[0017] The light magnifying optical system 20 of this embodiment has a first lenticular lens 21 and a second lenticular lens 22. In this embodiment, the first lenticular lens 21 and the second lenticular lens 22 are separate lenses, which makes it easy to manufacture the lenses.

[0018] The first lenticular lens 21 and the second lenticular lens 22 have the same shape, and therefore the lens pitch of the first lenticular lens 21 and the second lenticular lens 22 is the same.

[0019] The first lenticular lens 21 includes a first substrate 21b, which is a flat, light-transmitting substrate, and a plurality of first lenses 21a provided on the first substrate 21b. The plurality of first lenses 21a are provided on the first substrate 21b so as to be aligned in the Z-axis direction. Each of the first lenses 21a is a cylindrical convex lens that has positive power in the Z-axis direction and no power in the Y-axis direction. Therefore, each of the first lenses 21a splits the illumination light L incident from the light source unit 10 into a plurality of light beams in the Z-axis direction. Each light beam is diffused in the Z-axis direction, where the lens has power.

[0020] The second lenticular lens 22 includes a second substrate 22b, which is a flat, light-transmitting substrate, and a plurality of second lenses 22a provided on the second substrate 22b. The plurality of second lenses 22a are provided on the second substrate 22b so as to be aligned in the Z-axis direction. The plurality of second lenses 22a correspond to the plurality of first lenses 21a of the first lenticular lens 21, respectively. Each of the second lenses 22a is a cylindrical convex lens that has positive power in the Z-axis direction and no power in the Y-axis direction.

[0021] The second lenticular lens 22, in the Z-axis direction having lens power, forms an image of each first lens 21a of the first lenticular lens 21 together with the downstream superimposition optical system 30 onto or near the image forming area 2a of the light modulation device 2, which is the illuminated area.

[0022] The first lenticular lens 21 and the second lenticular lens 22 transmit the illumination light L incident from the light source unit 10 without changing the traveling direction in the Y-axis direction, in which they have no lens power. The illumination light L transmitted through the first lenticular lens 21 and the second lenticular lens 22 in the Y-axis direction is condensed by the superimposing optical system 30 onto the image forming region 2a of the light modulation device 2 or in the vicinity thereof.

[0023] In this way, the light magnifying optical system 20 of this embodiment diffuses the illumination light L emitted from the light source unit 10 in the Z-axis direction, and generates rectangular magnified illumination light WL extending in the Z-axis direction. The rate of change (degree of diffusion) of the light beam width in the Z-axis direction in the light magnification optical system 20 can be adjusted, for example, by adjusting the optical properties such as the curvature and refractive index of each lens constituting the first lenticular lens 21 and the second lenticular lens 22.

[0024] The optical scanning unit 40 scans the illuminated area in the Y-axis direction with the magnified illumination light WL incident from the optical magnifying optical system 20. Specifically, the optical scanning unit 40 scans the image forming area 2a of the optical modulation device 2 arranged in the illuminated area in the Y-axis direction with the band-shaped magnified illumination light WL extending in the Z-axis direction. Therefore, the optical scanning unit 40 can efficiently illuminate the entire image forming area 2a by scanning the band-shaped magnified illumination light WL in its short direction. Since the magnified illumination light WL overlap each other in the Y-axis direction, the uniformity of the intensity distribution in the image forming area 2a can be improved.

[0025] In this embodiment, a field lens 50 is provided between the optical scanning unit 40 and the light modulation device 2. The field lens 50 deflects the magnified illumination light WL incident from the optical scanning unit 40. This allows the optical scanning unit 40 to efficiently illuminate the image formation area 2a of the light modulation device 2 with the magnified illumination light WL.

[0026] In this embodiment, the optical scanning unit 40 scans the expanded illumination light WL incident from the superimposing optical system 30 on the image forming area 2a of the light modulation device 2 in the Y-axis direction. The optical scanning unit 40 includes a transmissive optical element 41 and a rotation driving unit 45 . The transmissive optical element 41 is made of a rotatably supported light-transmitting member. The transmissive optical element 41 is rotatable about a rotation axis O extending along the Z-axis direction. The transmissive optical element 41 is connected to a rotation drive unit 45 formed of a motor or the like. The transmissive optical element 41 rotates about the rotation axis O by being driven by the rotation drive unit 45.

[0027] The transmissive optical element 41 is made of a transmissive material such as optical glass (e.g., BK7), quartz, or resin. The transmissive optical element 41 of this embodiment has a front surface 41a and a back surface 41b that intersect with the rotation axis O, and four side surfaces 41c that are perpendicular to the front surface 41a and the back surface 41b. That is, the shape of the transmissive optical element 41 is a regular rectangular prism having six flat surfaces including the front surface 41a, the back surface 41b, and the four side surfaces 41c. The cross-sectional shape of the transmissive optical element 41 cut along a plane perpendicular to the rotation axis O is a square. That is, the four side surfaces 41c have the same area, and two opposing side surfaces are parallel to each other. The rotation axis O coincides with the center of the square-shaped transmissive optical element 41.

[0028] The transmitting optical element 41 rotates around the rotation axis O and transmits the magnified illumination light WL emitted from the optical magnifying optical system 20. Therefore, the side surface onto which the magnified illumination light WL emitted from the optical magnifying optical system 20 enters the transmitting optical element 41 is not fixed, but changes over time. Similarly, the side surface onto which the magnified illumination light WL incident on the transmitting optical element 41 is emitted into external space is not fixed, but changes over time. In the transmitting optical element 41, the side surface onto which the magnified illumination light WL emitted from the optical magnifying optical system 20 enters is referred to as the "incident surface." The side surface from which the magnified illumination light WL incident from the incident surface exits is referred to as the "exit surface." In this case, the incident surface and the exit surface change over time and are either two of the four side surfaces 41c that are parallel to each other.

[0029] In this specification, when two surfaces of the transmissive optical element 41 are said to be parallel to each other, the angle between the two surfaces is said to be in the range of 0±5 degrees, taking into consideration the processing accuracy of the glass material that makes up the translucent member, the allowable range of parallelism of light, etc.

[0030] In this embodiment, the transmissive optical element 41 has four side surfaces 41c, but the number of side surfaces does not necessarily have to be four, and is preferably 2×m (m: a natural number greater than or equal to 2). That is, the number of side surfaces is preferably an even number, such as 6 or 8. If the number of side surfaces is an even number, each of the side surfaces is parallel to the side surface opposite it, and there are no non-parallel side surfaces. This reduces the generation of stray light in the transmissive optical element 41, and improves light utilization efficiency.

[0031] The light modulation device 2 is provided on the light emission side of the light scanning unit 40 on the illumination optical axis AX. The light modulation device 2 modulates the expanded illumination light WL emitted from the light scanning unit 40 in accordance with image information to form image light. A transmissive liquid crystal panel is used for the light modulation device 2. The driving method for the liquid crystal panel is not particularly limited, and may be a twisted nematic (TN) method, a vertical alignment (VA) method, an in-plane switching (IPS) method, or the like.

[0032] Here, it is desirable to set the size of the expanded illumination light WL in the Z-axis direction (expansion direction of the expanded illumination light WL) that illuminates the image forming area 2a of the light modulation device 2 to be slightly larger than the size of the image forming area 2a of the light modulation device 2. Based on simulations, the present inventors have found that it is desirable to expand the size of the expanded illumination light WL outward by 0.5 mm or more.

[0033] 3 is a diagram showing the relationships between the optical components when viewed in a plane in the Y-axis direction. In order to make the diagram easier to understand, the optical scanning unit 40, field lens 50, and incident-side polarizing plate 3a, which are not used in the description, are omitted from the illustration in FIG.

[0034] In Figure 3, the lens pitch of the first lenticular lens 21 and the second lenticular lens 22 is a, the beam width of the magnified illumination light WL in the Z-axis direction is a1, the lens-to-lens distance between the first lenticular lens 21 and the second lenticular lens 22 is b, and the distance between the superimposing optical system 30 and the light modulation device 2 is b1.

[0035] The light emitted from the first lens 21a of the first lenticular lens 21 is collimated by the second lens 22a of the second lenticular lens 22 and is imaged on the image forming area 2a of the light modulation device 2 by the superposition optical system 30. Therefore, the relationship a:a1=b:b1 holds among the above-mentioned lens pitch a, light beam width a1, inter-lens distance b, and distance b1. Therefore, the light beam width a1 is defined by a1=a×b1 / b.

[0036] As mentioned above, it is desirable to consider a margin of 1.0 mm or more on both sides for the beam width in the Z-axis direction of the magnified illumination light WL. Therefore, when the margin of the magnified illumination light WL is taken into consideration, the dimension S in the Z-axis direction of the image formation area 2a satisfies the relationship of the following equation (1). S<(a×b1 / b)-1.0 Equation (1)

[0037] If the above formula (1) is satisfied, the magnified illumination light WL can illuminate the image forming area 2a of the light modulation device 2 satisfactorily even if there is variation in the installation of optical components or the precision of the lenticular lens is poor.

[0038] The incident-side polarizing plate 3a is disposed on the light incident side of the light modulation device 2 along the illumination optical axis AX. The exit-side polarizing plate 3b is disposed on the light exit side of the light modulation device 2 along the illumination optical axis AX. The transmission axes of the incident-side polarizing plate 3a and the exit-side polarizing plate 3b are perpendicular to each other.

[0039] The incident-side polarizing plate 3a transmits a linearly polarized component of the expanded illumination light WL emitted from the light source unit 10 in a specific direction toward the light modulation device 2. The exit-side polarizing plate 3b transmits the linearly polarized component of the expanded illumination light WL in a specific direction toward the projection optical device 4. In this embodiment, because the light source unit 10 uses a laser light-emitting element, the illumination light L incident from the light source unit 10 is linearly polarized. However, in the transmissive optical element 41, as the amount of light transmitted through the translucent member increases, the amount of light absorbed by the translucent member also increases, which may cause thermal distortion of the translucent member. In this case, the polarization direction of the illumination light L emitted from the light source unit 10 is disturbed, and the linearly polarized light incident on the translucent member becomes elliptically polarized and exits the translucent member. In this embodiment, the provision of the incident-side polarizing plate 3a allows the linearly polarized component in a specific direction to enter the light modulation device 2 even when the polarization direction of the illumination light L is disturbed. In addition, if quartz, a glass material with a small Young's modulus and thermal expansion coefficient, is used as the transmitting optical element 41, it is less likely to cause disturbance in the polarization direction, so the incident-side polarizing plate 3a provided on the light incident side of the light modulation device 2 can be omitted.

[0040] The projection optical device 4 is composed of a plurality of projection lenses, and projects the image light modulated by the light modulation device 2 onto a projection surface such as a screen in an enlarged scale. As a result, an image is displayed on the projection surface.

[0041] The following describes in detail the behavior of the magnified illumination light WL when it passes through the transmitting optical element 41. Note that the colored light rays LB, LG, and LR contained in the magnified illumination light WL behave similarly, so the following describes the behavior of the blue light rays LB and the behavior when switching from the blue light rays LB to the green light rays LG.

[0042] 4A to 4E are schematic diagrams for explaining the behavior of the blue light LB when the transmissive optical element 41 rotates. In this example, when viewed from the +Z side, the transmissive optical element 41 rotates clockwise around the rotation axis O, and time passes from FIG. 4A to FIG. 4E. The rotation driver 45 is not shown in FIGS. 4A to 4E.

[0043] 4A to 4E, the angle formed by the illumination optical axis AX and a straight line M connecting the rotation axis O with the apex 41d1, which is the intersection of the side surfaces 41c1 and 41c2, is defined as the rotation angle ω of the transmissive optical element 41. In reality, the blue light ray LB has a predetermined luminous flux width in the Z-axis direction, but here we will focus on the behavior of the chief ray traveling on the illumination optical axis AX. In Figures 4A to 4E, the left side shows the displacement m of the principal ray of the blue light LB from the illumination optical axis AX, and the right side shows how the blue light LB scans the image formation area 2a, which is the illuminated area.

[0044] 4A is a diagram showing the initial state in which a blue light ray LB is incident on the transmissive optical element 41. In the state shown in FIG. 4A, the line M and the illumination optical axis AX overlap, and the rotation angle ω is 0 degrees. At this time, the blue light ray LB is incident on the end of the side surface 41c2 on the +Y side at an incident angle (45 degrees). The blue light ray LB is refracted in the direction shown in the figure (toward the +Y side) and travels inside the transmissive optical element 41. Next, the blue light ray LB is also incident on the side surface 41c4 at the same incident angle as on the side surface 41c2, so it is refracted at the side surface 41c4 and emerges from the transmissive optical element 41. At this time, because side surface 41c2 and side surface 41c4 are parallel to each other, the angle of incidence of blue light LB with respect to side surface 41c2 is equal to the angle of incidence of blue light LB with respect to side surface 41c4, and the refraction angle of blue light LB incident on side surface 41c2 and the refraction angle of blue light LB emerging from side surface 41c4 have opposite signs but equal absolute values. As a result, the refraction angle of blue light LB upon incidence on side surface 41c2 and the refraction angle upon emergence from side surface 41c4 cancel each other out. As a result, blue light LB travels parallel to illumination optical axis AX at a position displaced by displacement amount m toward the +Y side from illumination optical axis AX. As a result, the blue light LB emitted from the transmitting optical element 41 is incident on the end 2a1 on the +Y side of the image forming area 2a of the light modulation device 2, which is the illuminated area.

[0045] Next, as shown in Figure 4B, when the rotation angle ω of the transmissive optical element 41 becomes larger than that shown in Figure 4A, the angle of incidence of the blue light beam LB becomes smaller, and the angle of refraction also becomes smaller. Therefore, the displacement m of the blue light beam LB from the illumination optical axis AX becomes smaller than that shown in Figure 4A. Furthermore, the state in which the blue light beam LB travels parallel to the illumination optical axis AX is always maintained. When the rotation angle ω is between 0 degrees and 45 degrees, the displacement m decreases monotonically as the rotation angle ω increases. As a result, the blue light LB emitted from the transmission optical element 41 is incident on the −Y side of the image forming area 2a of the light modulation device 2, compared to the case of FIG. 4A.

[0046] Next, as shown in FIG. 4C, when the rotation angle ω of the transmissive optical element 41 becomes 45 degrees, which is larger than that shown in FIG. 4B, the line M and the illumination optical axis AX overlap, and the blue light ray LB is incident perpendicularly on the side surface 41c2. In other words, the incident angle of the blue light ray LB with respect to the side surface 41c2 is 0 degrees. Therefore, since the blue light ray LB is incident perpendicularly on the side surface 41c2, it travels along the illumination optical axis AX inside the transmissive optical element 41 without being refracted at the side surface 41c2. Next, the blue light ray LB is also incident perpendicularly on the side surface 41c4, which is parallel to the side surface 41c2. Therefore, the blue light ray LB is emitted from the transmissive optical element 41 without being refracted at the side surface 41c4 either, and travels along the illumination optical axis AX. At this time, the blue light ray LB emitted from the transmissive optical element 41 is incident on the center of the image formation region 2a of the light modulation device 2 in the Y-axis direction.

[0047] Next, as shown in FIG. 4D, when the rotation angle ω of the transmissive optical element 41 exceeds 45 degrees, the incident position of the blue light LB shifts from the center of the side surface 41c2 toward the side surface 41c3. At this time, the blue light LB is refracted at the side surface 41c2, but the refraction direction is different from that in the period up to FIG. 4B, and it is refracted in the direction shown in the figure (toward the -Y direction). The relationship in which the refraction angle of the blue light LB when it enters the side surface 41c2 and the refraction angle when it exits the side surface 41c4 cancel each other out remains unchanged from the period up to FIG. 4B. As a result, the blue light LB travels parallel to the illumination optical axis AX at a position displaced by a displacement m toward the -Y direction from the illumination optical axis AX. When the rotation angle ω is between 45 degrees and 90 degrees, the displacement m increases monotonically as the rotation angle ω increases. As a result, the blue light LB emitted from the transmitting optical element 41 is incident on the −Y side of the center of the image forming area 2a of the light modulation device 2.

[0048] Next, as shown in FIG. 4E, the rotation angle ω of the transmissive optical element 41 reaches a maximum, and the displacement m reaches a maximum while maintaining the state in which the blue light ray LB travels parallel to the illumination optical axis AX. As a result, the blue light LB emitted from the transmitting optical element 41 is incident on the end 2a2 on the −Y side of the image forming area 2a of the light modulation device 2, which is the illuminated area. In this way, the blue light beam LB incident on the side surface 41c2 of the rotating transmissive optical element 41 can scan the image forming area 2a of the light modulation device 2 in the Y-axis direction.

[0049] 4E, the apex 41d2 of the transmissive optical element 41, which is located at the boundary between the side surface 41c2 and the side surface 41c3, overlaps with the illumination optical axis AX. In this embodiment, at the timing shown in FIG. 4E, the light source unit 10 switches the emitted illumination light L from blue light LB to green light LG.

[0050] FIG. 5 is a diagram showing the behavior of light transmitted through the transmission optical element 41 when the blue light LB is switched to the green light LG. 5, at the timing when the top 41d2 of the transmissive optical element 41 overlaps with the illumination optical axis AX, the blue light LB or the green light LG is incident on both side surfaces 41c2 and 41c3 of the transmissive optical element 41 and is emitted from side surfaces 41c4 and 41c1, respectively. In other words, when switching from blue light LB to green light LG, the blue light LB and the green light LG emitted from the transmissive optical element 41 are separated into two in the Y-axis direction. For example, if the blue light LB and the green light LG are incident on both ends of the image forming area 2a in the Y-axis direction, respectively, different colored lights will be incident sequentially on the same area (both ends in the Y-axis direction) of the image forming area 2a, resulting in a degradation in the quality of the projected image due to color mixture.

[0051] In contrast, in the projector 100 of this embodiment, when the expanded illumination light WL is split into two in the Y-axis direction after passing through the transmissive optical element 41, the size of the image forming area 2a is set so that the two split lights are incident outside the image forming area 2a, thereby making it possible to suppress the occurrence of color mixing.

[0052] However, if the luminous flux width in the Y-axis direction of the illumination light L emitted by the light source unit 10 is increased, the time during which the illumination light L is separated into two increases, and the time during which the illumination light L emitted by the light source unit 10 is not incident on the image forming area 2a increases, resulting in a problem of reduced utilization efficiency of the illumination light L emitted from the light source unit 10.

[0053] The inventors considered that if the beam width of the illumination light L is too narrow, it will cause localized heat generation in the image forming area 2a, and conversely, if the beam width of the illumination light L is too wide, the utilization efficiency of the illumination light L in the image forming area 2a will decrease as described above, and therefore it is desirable to make the beam width of the illumination light L less than half that of the image forming area 2a.

[0054] Fig. 6 is a diagram showing the relationships between the optical components when viewed in a plane in the Z-axis direction. To make the diagram easier to understand, Fig. 6 omits the illustration of the optical scanning unit 40, field lens 50, and incident-side polarizing plate 3a, which are not used in the description. Fig. 6 also shows the blue light-emitting unit 10B of the light source unit 10.

[0055] In Figure 6, the dimension in the Y-axis direction of the light-emitting region 11 of the light-emitting element 10B1 of the blue light-emitting unit 10B is c, the beam width in the Y-axis direction of the expanded illumination light WL is c1, the focal length of the collimating lens 10B2 of the blue light-emitting unit 10B is d, and the distance between the superimposing optical system 30 and the light modulation device 2 is d1.

[0056] Blue light beam LB emitted from light-emitting region 11 of light-emitting element 10B1 is collimated by collimating lens 10B2. Because first lenticular lens 21 and second lenticular lens 22 have no lens power in the Y-axis direction, blue light beam LB collimated by collimating lens 10B2 passes through first lenticular lens 21 and second lenticular lens 22. Blue light beam LB is then imaged on image forming region 2a of light modulation device 2 by superimposing optical system 30. Therefore, the dimension c of light-emitting region 11, light beam width c1, focal length d, and distance d1 satisfy the relationship c:c1=d:d1. Therefore, light beam width c1 is defined by c1=c×d1 / d.

[0057] As described above, it is desirable that the luminous flux width in the Y-axis direction of the expanded illumination light WL be equal to or less than half of the image forming area 2a, taking into consideration heat generation and a decrease in light utilization efficiency. Therefore, in the projector 100 of this embodiment, the dimension S1 in the Y-axis direction of the image forming area 2a satisfies the relationship of the following equation (2). S1>2×c×d1 / d Formula (2) If the above formula (2) is satisfied, it is possible to suppress heat generation in the image forming area and to allow light from the light source device to be efficiently incident on the image forming area.

[0058] As described above, the light source device 1 of this embodiment includes a light source unit 10 that emits illumination light L in the Y-axis direction, the illumination light L including blue light rays LB, green light rays LG, and red light rays LR that are aligned in the Y-axis direction; an optical expansion optical system 20 that generates expanded illumination light WL by expanding the illumination light L in the Z-axis direction; a superimposition optical system 30 that superimposes the expanded illumination light WL emitted from the optical expansion optical system 20 on the image forming area 2a of the optical modulation device 2, which is the illuminated area; and an optical scanning unit 40 that scans the light incident from the superimposition optical system 30 over the image forming area 2a in the Y-axis direction.

[0059] In other words, the light source device 1 of this embodiment comprises a light source unit 10 that emits illumination light L including multiple light rays LB, LG, and LR emitted from a light-emitting point on the same plane, a first lenticular lens 21 and a second lenticular lens 22 that generate enlarged illumination light WL by enlarging the illumination light L in a direction along the Z axis (third axis), a superimposing optical system 30 that superimposes the enlarged illumination light WL on the image forming area 2a of the light modulation device 2, which is the illuminated area, and an optical scanning unit 40 that scans the enlarged illumination light WL emitted from the superimposing optical system 30 in a direction along the Y axis (fourth axis).

[0060] According to the light source device 1 of this embodiment, the light magnifying optical system 20 can convert the illumination light L emitted from the light source unit 10 into rectangular expanded illumination light WL that is elongated in the Z-axis direction. The expanded illumination light WL extends in a direction perpendicular to the optical scanning direction by the optical scanning unit 40. Therefore, the optical scanning unit 40 can efficiently illuminate the entire image formation region 2a of the light modulation device 2 with the expanded illumination light WL.

[0061] The light magnification optical system 20 of this embodiment is composed of a first lenticular lens 21 and a second lenticular lens 22, and therefore can easily generate magnified illumination light WL by magnifying the illumination light L emitted from the light source unit 10 in one axial direction.

[0062] According to the projector 100 of this embodiment, the expanded illumination light WL emitted from the light source device 1 is scanned over the image forming area 2a of the light modulation device 2, so that a bright image can be projected.

[0063] (First Modification) A first modification of the above embodiment will now be described. This modified example differs from the above embodiment in the configuration of the optical magnification optical system. Note that the same reference numerals are used to designate the same components as those in the above embodiment, and detailed descriptions thereof will be omitted.

[0064] FIG. 7 is a plan view showing a schematic configuration of the light magnifying optical system 120 of this modified example as viewed from the +Y side. 7, the light expanding optical system 120 of this modified example has a first lenticular lens 121, a second lenticular lens 122, and a base material 130. The base material 130 is a light-transmitting substrate, and the first lenticular lens 121 is provided on a first surface 130a side, and the second lenticular lens 122 is provided on a second surface 130b side opposite the first surface 130a. In other words, in the light expanding optical system 120 of this modified example, the first lenticular lens 121 and the second lenticular lens 122 are an integrated lens.

[0065] In the case of this modified example, the first lenticular lens 121 and the second lenticular lens 122 are an integrated lens, so there is no need to align the first lenticular lens 121 and the second lenticular lens 122. Therefore, the light source device using the light magnifying optical system 120 of this modified example can simplify the assembly process.

[0066] (Second Modification) A second modification of the above embodiment will now be described. This modified example differs from the above embodiment in the configuration of the light source unit. Note that the same reference numerals are used to designate the same components as those in the above embodiment, and detailed descriptions thereof will be omitted.

[0067] FIG. 8 is a perspective view showing the main part of a light source section 210 of this modified example. 8, light source unit 210 of this modification includes blue light-emitting unit 60B, green light-emitting unit 60G, first red light-emitting unit 60R, and second red light-emitting unit 61R. Light source unit 210 causes blue light-emitting unit 60B, green light-emitting unit 60G, first red light-emitting unit 60R, and second red light-emitting unit 61R to emit light at different times.

[0068] The blue light-emitting unit 60B has the same configuration as the blue light-emitting unit 10B in the first embodiment and emits blue light LB. The green light-emitting unit 60G has the same configuration as the green light-emitting unit 10G in the first embodiment and emits green light LG. The first red light-emitting unit 60R and the second red light-emitting unit 61R have the same configuration as the red light-emitting unit 10R in the first embodiment and emit red light LR1 and LR2, respectively.

[0069] In this modification, the blue light-emitting unit 60B, the green light-emitting unit 60G, and the first red light-emitting unit 60R are arranged in order from the +Y side to the -Y side. The second red light-emitting unit 61R is arranged next to the first red light-emitting unit 60R in the Z-axis direction. That is, in this modification, the illumination light L emitted by the light source unit 210 includes a blue light ray LB, a green light ray LG, and a red light ray LR1 aligned in the Y-axis direction, and a red light ray LR2 aligned with the red light ray LR1 in the Z-axis direction. Therefore, in this modification, the luminous flux width in the Z-axis direction of the illumination light L emitted by the light source unit 210 is large.

[0070] In this embodiment, the red light ray LR1 corresponds to an example of the "first light ray" of the present invention, the green light ray LG corresponds to an example of the "second light ray" of the present invention, and the red light ray LR2 corresponds to an example of the "third light ray" of the present invention.

[0071] According to the light source section 210 of this modification, the color balance of the illumination light L can be further improved by increasing the number of red light rays LR, which tend to be insufficient in light intensity compared to the blue light rays LB and the green light rays LG, to two. Although this modification has been described as an example in which there are two red light beams, the number of blue light beams and the number of green light beams may each be increased to 2. That is, two blue light-emitting units 60B may be arranged side by side in the Y-axis direction, and two green light-emitting units 60G may be arranged side by side in the Y-axis direction.

[0072] The optical magnifying optical system 20 does not affect the beam width in the Z-axis direction of the magnified illumination light WL even when the beam width in the Z-axis direction of the illumination light L incident from the light source unit 210 changes. Therefore, according to the light source device of the present invention, the optical magnifying optical system 20 can generate rectangular magnified illumination light WL that extends elongatedly in the Z-axis direction, regardless of the beam width of the illumination light L emitted from the light source unit 210.

[0073] The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. In addition, the specific descriptions of the shape, number, arrangement, material, etc. of each component of the light source device and projector are not limited to the above-described embodiments and can be changed as appropriate. For example, in the above embodiment and modified examples, the light source unit 10 emits each color light beam LB, LG, and LR in time sequence as illumination light L, but if the application is to a projector that displays a single color, a single color light beam may be emitted from the light source unit.

[0074] A summary of this disclosure is provided below.

[0075] (Appendix 1) a light source unit that emits light including a first light ray and a second light ray aligned in a direction along a first axis in a direction intersecting the first axis; an optical magnification optical system that generates magnified light by magnifying the light in a direction along a second axis perpendicular to the first axis; a superimposing optical system that superimposes the expanded light emitted from the optical expanding optical system on an illuminated area; an optical scanning unit that scans the light incident from the superimposing optical system in a direction along the first axis on the illuminated area; Light source device.

[0076] In the light source device having this configuration, the light magnifying optical system can convert the light emitted from the light source unit into rectangular magnified light extending in the direction along the second axis. The magnified light extends in a direction perpendicular to the optical scanning direction of the optical scanning unit. This allows the optical scanning unit to efficiently illuminate the entire illuminated area with the magnified light.

[0077] (Appendix 2) The light expanding optical system includes a first lenticular lens that divides the light into a plurality of ray bundles, and a second lenticular lens that causes the plurality of ray bundles divided by the first lenticular lens to enter the superimposing optical system. 10. The light source device of claim 1.

[0078] According to this configuration, by using a light magnifying optical system made up of the first lenticular lens and the second lenticular lens, it is possible to satisfactorily generate magnified illumination light extending in the second axis direction.

[0079] (Appendix 3) the first lenticular lens includes a first substrate and a plurality of first lenses provided on the first substrate; The second lenticular lens includes a second substrate and a plurality of second lenses provided on the second substrate. 10. The light source device according to claim 2.

[0080] According to this configuration, the first lenticular lens and the second lenticular lens are separate bodies, which makes it easy to manufacture the lenses.

[0081] (Appendix 4) the optical magnifying optical system further includes a substrate on which the first lenticular lens is provided on a first surface side and the second lenticular lens is provided on a second surface side opposite to the first surface; 10. The light source device according to claim 2.

[0082] According to this configuration, since the first lenticular lens and the second lenticular lens are an integrated lens, there is no need to align the first lenticular lens and the second lenticular lens, which simplifies the assembly process.

[0083] (Appendix 5) Further provided is a field lens that deflects the light incident from the optical scanning unit. 10. The light source device of claim 1.

[0084] According to this configuration, the optical scanning unit can efficiently illuminate the illumination area with expanded light.

[0085] (Appendix 6) the light emitted by the light source unit further includes a third light ray aligned with the first light ray or the second light ray in a direction along the second axis; 10. The light source device of claim 1.

[0086] According to this configuration, even when the light source unit emits light including rays aligned in two directions along the first axis and the second axis, it is possible to generate expanded light extending in the direction along the second axis.

[0087] (Appendix 7) the first light beam and the second light beam are different color lights, and the light source unit emits the first light beam and the second light beam in time sequence. 10. The light source device of claim 1.

[0088] According to this configuration, the color of the light emitted from the light source device can be changed sequentially over time.

[0089] (Appendix 8) a light source unit that emits light including a plurality of light rays emitted from a light emitting point on the same plane; a first lenticular lens and a second lenticular lens that generate expanded light by expanding the light in a direction along a third axis; a superimposing optical system that superimposes the expanded light onto an illuminated area; and an optical scanning unit that scans the expanded light emitted from the superimposing optical system in a direction along a fourth axis perpendicular to the third axis. Light source device.

[0090] With this light source device, the first and second lenticular lenses can convert light containing multiple light rays emitted from a light-emitting point on the same plane into rectangular expanded light extending in a direction along the third axis. The expanded light extends in a direction perpendicular to the fourth axis, which is the optical scanning direction of the optical scanning unit. This allows the optical scanning unit to efficiently illuminate the entire illuminated area with expanded light.

[0091] (Appendix 9) a light source device according to any one of Supplementary Note 1 to Supplementary Note 8; a light modulation device that modulates light incident from the light source device; a projection optical device that projects the light modulated by the light modulation device; Equipped with projector.

[0092] According to a projector having this configuration, the expanded light emitted from the light source device scans the image forming area of ​​the light modulation device, so that a bright image can be projected.

[0093] (Appendix 10) A light source device according to any one of Supplementary Note 2 to Supplementary Note 4 and Supplementary Note 8; a light modulation device that modulates light incident from the light source device in accordance with image information; a projection optical device that projects the light modulated by the light modulation device, the light modulation device has an image forming area that generates image light; When the lens pitch of the first lenticular lens and the second lenticular lens is a, the inter-lens distance between the first lenticular lens and the second lenticular lens is b, and the distance between the superimposing optical system and the light modulation device is b1, A dimension S of the image forming area in a direction along the expansion direction of the expanded light satisfies the following relationship: projector. S<(a×b1 / b)-1.0

[0094] According to this configuration, even if there is variation in the mounting of optical components or the precision of the lenticular lens is poor, the image forming area of ​​the light modulation device can be satisfactorily illuminated with light from the light source device.

[0095] (Appendix 11) a light source device according to any one of Supplementary Note 1 to Supplementary Note 10; a light modulation device that modulates light incident from the light source device in accordance with image information; a projection optical device that projects the light modulated by the light modulation device, the light 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 collimator lens that collimates the first light ray emitted from the light emitting element, When the dimension of the light emitting region of the light emitting element in the direction along the first axis is c, the focal length of the collimator lens is d, and the distance between the superimposing optical system and the light modulation device is d1, A dimension S1 of the image forming area in a direction along the first axis satisfies the following relationship: projector. S1>2×c×d1 / d

[0096] According to this configuration, it is possible to suppress heat generation in the image forming area, while allowing light from the light source device to be efficiently incident on the image forming area. [Explanation of symbols]

[0097] 1...light source device, 2...light modulation device, 2a...image forming area, 4...projection optical device, 10,210...light source section, 11...light emitting area, 20,120...light magnification optical system, 21,121...first lenticular lens, 21a...first lens, 21b...first substrate, 22,122...second lenticular lens, 22a...second lens, 22b...second substrate, 30...superimposing optical system, 40...light scanning section, 130a...first surface, 130b...second surface, 50...field lens, 100...projector, 10B1...light emitting element, 10B2...collimating lens, 130...substrate, LB...blue light ray (first light ray), LG...green light ray (second light ray), LR1...red light ray (first light ray), LR2...red light ray (third light ray).

Claims

1. a light source unit that emits light including a first light ray and a second light ray aligned in a direction along a first axis, in a direction intersecting the first axis; an optical magnification optical system that generates magnified light by magnifying the light in a direction along a second axis perpendicular to the first axis; a superimposing optical system that superimposes the expanded light emitted from the optical expanding optical system on an illuminated area; an optical scanning unit that scans the light incident from the superimposing optical system in a direction along the first axis on the illuminated area, Light source device.

2. the light expanding optical system includes a first lenticular lens that divides the light into a plurality of ray bundles, and a second lenticular lens that causes the plurality of ray bundles divided by the first lenticular lens to enter the superimposing optical system. The light source device according to claim 1 .

3. the first lenticular lens includes a first substrate and a plurality of first lenses provided on the first substrate; The second lenticular lens includes a second substrate and a plurality of second lenses provided on the second substrate. The light source device according to claim 2 .

4. the optical magnifying optical system further includes a substrate on which the first lenticular lens is provided on a first surface side and the second lenticular lens is provided on a second surface side opposite to the first surface; The light source device according to claim 2 .

5. Further provided is a field lens that deflects the light incident from the optical scanning unit. The light source device according to claim 1 .

6. the light emitted by the light source unit further includes a third light ray aligned with the first light ray or the second light ray in a direction along the second axis; The light source device according to claim 1 .

7. the first light beam and the second light beam are different color lights, and the light source unit emits the first light beam and the second light beam in time sequence. The light source device according to claim 1 .

8. a light source unit that emits light including a plurality of light rays emitted from a light emitting point on the same plane; a first lenticular lens and a second lenticular lens that generate expanded light by expanding the light in a direction along a third axis; a superimposing optical system that superimposes the expanded light onto an illuminated area; an optical scanning unit that scans the expanded light emitted from the superimposing optical system in a direction along a fourth axis perpendicular to the third axis, Light source device.

9. The light source device according to claim 1 or claim 8; a light modulation device that modulates light incident from the light source device; a projection optical device that projects the light modulated by the light modulation device; Equipped with projector.

10. a light source device according to any one of claims 2 to 4 and claim 8; a light modulation device that modulates light incident from the light source device in accordance with image information; a projection optical device that projects the light modulated by the light modulation device, the light modulation device has an image forming area; When the lens pitch of the first lenticular lens and the second lenticular lens is a, the inter-lens distance between the first lenticular lens and the second lenticular lens is b, and the distance between the superimposing optical system and the light modulation device is b1, A dimension S of the image forming area in a direction along the expansion direction of the expanded light satisfies the following relationship: projector. S<(a×b1 / b)-1.0

11. The light source device according to claim 1 ; a light modulation device that modulates light incident from the light source device in accordance with image information; a projection optical device that projects the light modulated by the light modulation device, the light 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 beam and a collimator lens that collimates the first light beam emitted from the light emitting element, When the dimension of the light emitting region of the light emitting element in the direction along the first axis is c, the focal length of the collimator lens is d, and the distance between the superimposing optical system and the light modulation device is d1, A dimension S1 of the image forming area in a direction along the first axis satisfies the following relationship: projector. S1>2×c×d1 / d

Images