Light source device and projector

Abstract

To provide a light source device that can emit light with high parallelism.SOLUTION: A light source device of the present invention comprises: a first light source unit that emits first light in a first wavelength range; a second light source unit that emits second light in a second wavelength range; a third light source unit that emits third light in a third wavelength range; and a transmissive optical element that transmits the rays of light. The transmissive optical element is rotatable centered on a rotation axis extending along a first direction. A cross-sectional shape perpendicular to a principal ray of the light emitted from each light source unit is a shape having a major axis extending along the first direction. The first light is incident on a first position of the transmissive optical element. The second light is incident on a second position of the transmissive optical element. The third light is incident on a third position of the transmissive optical element. In the transmissive optical element, an incidence surface on which the rays of light are incident and an emission surface from which the rays of light incident from the incidence surface are emitted, are parallel to each other.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] 2. Description of the Related Art 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 scanning light emitted from a light emitting element on the light modulation device in time.

[0003] The following Patent Document 1 discloses a projector including 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. In this projector, the light source device emits light having an elliptical light beam cross section. The polygon mirror reflects the light emitted from the light source device and scans the light in the minor axis direction of the elliptical light beam cross section on the image forming area of ​​the liquid crystal light valve. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2007-225956 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, when a polygon mirror is used for scanning light, as in the projector of Patent Document 1, even if completely parallel light is incident on the polygon mirror, the parallelism of the light is lost due to the polygon mirror. That is, since the polygon mirror reflects light while rotating, the angle of incidence of the light on the reflecting surface of the polygon mirror changes over time, and the parallel light incident on the polygon mirror becomes light with a certain divergence angle and illuminates the liquid crystal light valve. As a result, various problems related to the image quality of the projector may occur, such as a decrease in brightness and contrast in the liquid crystal light valve, the occurrence of color unevenness, and light loss in the projection lens. [Means for solving the problem]

[0006] In order to solve the above problem, a light source device according to one embodiment of the present invention includes a first light source unit that emits a first light in a first wavelength band, a second light source unit that emits a second light in a second wavelength band different from the first wavelength band, a third light source unit that emits a third light in a third wavelength band different from the first wavelength band and the second wavelength band, and a transmissive optical element that is made of a rotatably supported light-transmitting member and transmits each of the first light, the second light, and the third light. The transmissive optical element is rotatable about a rotation axis that extends along a first direction that intersects each of the incident direction of the first light, the incident direction of the second light, and the incident direction of the third light. The cross-sectional shape perpendicular to the principal ray of the first light emitted from the first light source unit has a major axis that extends along the first direction. The cross-sectional shape perpendicular to the principal ray of the second light emitted from the second light source unit has a major axis that extends along the first direction. A cross-sectional shape perpendicular to a principal ray of the third light emitted from the third light source unit has a long axis extending along the first direction. The first light is incident on the transmissive optical element at a first position. The second light is incident on the transmissive optical element at a second position different from the first position. The third light is incident on the transmissive optical element at a third position different from the first position and the second position. In the transmissive optical element, an entrance surface on which the first light, the second light, and the third light are incident and an exit surface from which the first light, the second light, and the third light incident from the entrance surface are exited are parallel to each other.

[0007] A projector of one embodiment of the present invention comprises a light source device of one embodiment of the present invention, a light modulation device that modulates light including the first light, the second light, and the third light emitted from the transmissive optical element of the light source device based on image information, and a projection optical device that projects the light modulated by the light modulation device. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a plan view showing a schematic configuration of a projector according to a first embodiment. [Diagram 2] FIG. 2 is a side view of the projector. [Diagram 3] FIG. 2 is a perspective view of a transmissive optical element. [Figure 4] 4 is a schematic diagram showing light emitted from a second light source unit. FIG. [Figure 5A] 1A and 1B are schematic diagrams for explaining the behavior of light when a transmissive optical element rotates. [Figure 5B] FIG. 5B is a schematic diagram showing a continuation of FIG. 5A. [Figure 5C] FIG. 5C is a schematic diagram showing a continuation of FIG. 5B. [Figure 5D] FIG. 5D is a schematic diagram showing a continuation of FIG. 5C. [Figure 5E] FIG. 5B is a schematic diagram showing a continuation of FIG. 5D. [Figure 5F] FIG. 5B is a schematic diagram showing a continuation of FIG. 5E. [Figure 6] FIG. 11 is a diagram showing the relationship between the illuminance distribution of light and the propagation distance. [Figure 7] FIG. 2 is a cross-sectional view of the optical modulation device. [Figure 8] FIG. 11 is a plan view showing a schematic configuration of a projector according to a second embodiment. [Figure 9] FIG. 11 is a plan view showing a schematic configuration of a projector according to a third embodiment. [Figure 10] FIG. 2 is a side view of the projector. [Figure 11] FIG. 11 is a plan view showing a schematic configuration of a projector according to a fourth embodiment. [Figure 12] FIG. 2 is a side view of the projector. [Figure 13] FIG. 13 is a plan view showing a schematic configuration of a projector according to a fifth embodiment. [Figure 14] FIG. 2 is a schematic diagram showing how three color lights are scanned on a light modulation device. [Figure 15] FIG. 13 is a plan view showing a schematic configuration of a projector according to a sixth embodiment. [Figure 16] FIG. 13 is a plan view showing a schematic configuration of a projector according to a seventh embodiment. [Figure 17] FIG. 13 is a plan view showing a schematic configuration of a projector according to an eighth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [First embodiment] Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. The projector of this embodiment is an example of a liquid crystal projector that uses a liquid crystal panel as a light modulation device. In the drawings, the dimensions of the components may be shown on different scales in order to make the components easier to see.

[0010] Fig. 1 is a plan view showing a schematic configuration of a projector 20 of this embodiment. Fig. 2 is a side view showing a schematic configuration of the projector 20. In Fig. 2, the first light source section 11, the third light source section 13, the first reflecting element 17, the second reflecting element 18, etc. are omitted from illustration. Fig. 3 is a perspective view of a transmissive optical element 14.

[0011] As shown in FIGS. 1 and 2, a projector 20 of the present embodiment includes a light source device 10, a light modulation device 21, an exit side polarizing plate 22, and a projection optical device .

[0012] The light source device 10 of this embodiment includes a first light source section 11, a second light source section 12, a third light source section 13, a transmissive optical element 14, a rotary drive device 15, a first reflecting element 17, and a second reflecting element 18.

[0013] In the following, the XYZ Cartesian coordinate system is used in the drawings as necessary for explanation. The X-axis is an axis parallel to the optical axis AX2 of the second light source unit 12. The optical axis AX2 of the second light source unit 12 is defined as an axis along the principal ray of the second light LG emitted from the second light source unit 12. The Y-axis is an axis perpendicular to the X-axis and is an axis along the rotation axis C1 of the transmissive optical element 14. The Z-axis is an axis perpendicular to the X-axis and Y-axis and is an axis parallel to the optical axis AX1 of the first light source unit 11 and the optical axis AX3 of the third light source unit 13. The optical axis AX1 of the first light source unit 11 is defined as an axis along the principal ray of the first light LB emitted from the first light source unit 11. The optical axis AX3 of the third light source unit 13 is defined as an axis along the principal ray of the third light LR emitted from the third light source unit 13. The Y-axis direction in this embodiment corresponds to the first direction in the claims, and the Z-axis direction in this embodiment corresponds to the second direction in the claims.

[0014] 1, the first light source unit 11 emits a first light LB in a first wavelength band toward the transmissive optical element 14 (-Z side). The second light source unit 12 emits a second light LG in a second wavelength band toward the transmissive optical element 14 (+X side). The third light source unit 13 emits a third light LR in a third wavelength band toward the transmissive optical element 14 (+Z side).

[0015] The optical axis AX1 of the first light source unit 11 and the optical axis AX3 of the third light source unit 13 are located on the same axis. The optical axis AX2 of the second light source unit 12 is perpendicular to the optical axis AX1 of the first light source unit 11 and the optical axis AX3 of the third light source unit 13. With this configuration, for example, when each light source unit includes a cooling member such as a heat sink, it is not necessary to arrange the cooling member or the flow path of the cooling air at an angle. This increases the degree of freedom in the layout of the components that configure the projector 20, and allows the projector 20 to be made smaller.

[0016] Although the basic configurations of the light source sections 11, 12, and 13 are similar, Figures 2 and 3 show the detailed configuration of the second light source section 12, so below we will explain the specific configuration of the second light source section 12 using Figures 2 and 3.

[0017] As shown in Fig. 2 and Fig. 3, the second light source unit 12 includes a plurality of second light-emitting elements 26 and a substrate 29. The second light-emitting elements 26 are configured from laser diodes that emit light beams LG0 in a second wavelength band. Therefore, the light beams LG0 emitted from the second light-emitting elements 26 are linearly polarized light having coherence, and are laser beams with a narrow beam width and high parallelism. The second wavelength band is, for example, a green wavelength band of 530 nm ± 5 nm. That is, the light beams LG0 emitted from the second light-emitting elements 26 are green light.

[0018] The second light-emitting elements 26 are arranged in a row at predetermined intervals along the Y-axis direction. In the present embodiment, the second light source unit 12 includes five second light-emitting elements 26, but the number of the second light-emitting elements 26 is not particularly limited as long as the second light-emitting elements 26 are arranged in a row along the Y-axis direction.

[0019] FIG. 4 is a diagram showing a cross section perpendicular to the traveling direction of the second light LG emitted from the second light source unit 12. In the case of this embodiment, since the light ray LG0 is emitted from each of the five second light emitting elements 26, the second light LG emitted from the second light source unit 12 is the entire light flux including the five light rays LG0 as shown in FIG. 4. Therefore, the outer edge of the second light LG is defined as the outer edge of the figure circumscribing the five light rays LG0. Also, the main ray of the second light LG is defined as the light ray passing through the center of the figure circumscribing the five light rays LG0. In this case, the cross-sectional shape perpendicular to the main ray of the second light LG is a belt-like shape having a long axis extending along the Y-axis direction and a short axis extending along the Z-axis direction. It is desirable that the length Lz of the short axis of the cross-sectional shape perpendicular to the main ray of the second light LG is appropriately shorter than the length LVz of the short axis extending along the Z-axis direction of the light modulation device 21. For example, the ratio Lz / LVz of the length Lz of the minor axis of the cross-sectional shape perpendicular to the principal ray of the second light LG to the length LVz of the minor axis of the light modulation device 21 is preferably 1 / 2 or less. Considering area illumination described later, it is more preferable that the ratio Lz / LVz is 1 / 4 or less. Hereinafter, the second light LG is referred to as green light LG. According to this embodiment, it is possible to generate light having a cross-sectional shape with a major axis extending along the Y-axis direction without using an optical system such as a light beam width adjustment optical system.

[0020] The substrate 29 supports the multiple second light-emitting elements 26. Although not shown, a heat sink for cooling the multiple second light-emitting elements 26 may be provided on one of the two main surfaces of the substrate 29 opposite to the side on which the multiple second light-emitting elements 26 are provided.

[0021] As shown in FIG. 1, the first light source unit 11 includes a plurality of first light-emitting elements 25 and a substrate 29. The first light-emitting element 25 is composed of a laser diode that emits a light beam LB0 in a first wavelength band. Therefore, the light beam LB0 emitted from the first light-emitting element 25 is a laser light that is linearly polarized light having coherence, has a narrow beam width, and is highly parallel. The first wavelength band is, for example, a blue wavelength band of 450 nm±5 nm. That is, the light beam LB0 emitted from the first light-emitting element 25 is blue light. Note that, although a laser diode is given as the first light-emitting element 25 in this embodiment, it is not limited thereto, and a light source such as an LED or a lamp, an optical system that adjusts the polarization direction of light, an optical system that adjusts the beam width, a color wheel, or the like is used to generate a light beam with a ratio Lz / LVz of 1 / 2 or less, and the laser diode can be replaced.

[0022] The multiple first light-emitting elements 25 are arranged in a row at predetermined intervals from each other along the Y-axis direction, i.e., the direction perpendicular to the paper surface of Fig. 1. In this embodiment, the first light source unit 11 includes five first light-emitting elements 25, but the number of the first light-emitting elements 25 is not particularly limited as long as the multiple first light-emitting elements 25 are arranged in a row along the Y-axis direction. Hereinafter, the first light LB is referred to as blue light LB.

[0023] The third light source unit 13 includes a plurality of third light-emitting elements 27 and a substrate 29. The third light-emitting elements 27 are configured from laser diodes that emit light beams LR0 in a third wavelength band. Therefore, the light beams LR0 emitted from the third light-emitting elements 27 are linearly polarized light having coherence, and are laser beams with a narrow beam width and high parallelism. The third wavelength band is, for example, a red wavelength band of 650 nm±5 nm. That is, the light beams LR0 emitted from the third light-emitting elements 27 are red light.

[0024] The third light-emitting elements 27 are arranged in a row at predetermined intervals from each other along the Y-axis direction, i.e., the direction perpendicular to the paper surface of Fig. 1. In this embodiment, the third light source unit 13 includes five third light-emitting elements 27, but the number of the third light-emitting elements 27 is not particularly limited as long as the third light-emitting elements 27 are arranged in a row along the Y-axis direction. Hereinafter, the third light LR is referred to as red light LR.

[0025] As shown in FIG. 1, the transmissive optical element 14 is provided at a position where the optical axis AX1 and the optical axis AX3 intersect with the optical axis AX2. The transmissive optical element 14 is composed of a rotatably supported light-transmitting member. As the glass material of the light-transmitting member constituting the transmissive optical element 14, for example, optical glass such as BK7, quartz, resin, or other light-transmitting materials are used. The transmissive optical element 14 is rotatable about a rotation axis C1 extending along the Y-axis direction. The rotation axis C1 is connected to a rotation drive device 15 including a motor or the like. The transmissive optical element 14 rotates about the rotation axis C1 by being driven by the rotation drive device 15.

[0026] As shown in Fig. 3, the transmissive optical element 14 has a first surface 14a and a second surface 14b that intersect with the rotation axis C1, and four side surfaces 14c1, 14c2, 14c3, and 14c4 that are in contact with the first surface 14a and the second surface 14b perpendicularly. That is, the shape of the transmissive optical element 14 is a regular rectangular prism having six planes including the first surface 14a, the second surface 14b, and the four side surfaces 14c1, 14c2, 14c3, and 14c4. The cross-sectional shape of the transmissive optical element 14 cut along a plane perpendicular to the rotation axis C1 is a square. That is, the four side surfaces 14c1, 14c2, 14c3, and 14c4 have the same area, and the two side surfaces that face each other are parallel to each other.

[0027] The transmissive optical element 14 transmits each of the blue light LB, green light LG, and red light LR emitted from each light source unit 11, 12, and 13 while rotating around the rotation axis C1. Therefore, the side surface on which each color light LB, LG, and LR emitted from each light source unit 11, 12, and 13 enters the transmissive optical element 14 is not determined, but changes over time. In the transmissive optical element 14, the side surface on which each color light LB, LG, and LR emitted from each light source unit 11, 12, and 13 enters is called the incident surface. The side surface from which each color light LB, LG, and LR incident from the incident surface exits is called the exit surface. In this case, the incident surface and the exit surface change over time and are either of two parallel side surfaces among the four side surfaces 14c1, 14c2, 14c3, and 14c4.

[0028] In this specification, when the two side surfaces of the transmissive optical element 14 are said to be parallel to each other, the angle between the two side surfaces is said to be "parallel" when it is within the range of 0±5 degrees, taking into consideration the processing accuracy of the glass material constituting the light-transmitting member, the allowable range of parallelism of light, etc.

[0029] As shown in FIG. 1, the blue light LB is incident on the first position P1 of the transmissive optical element 14. The green light LG is incident on the transmissive optical element 14 on a second position P2 different from the first position P1. The red light LR is incident on the transmissive optical element 14 on a third position P3 different from the first position P1 and the second position P2. That is, the blue light LB, the green light LG, and the red light LR are incident on different positions of the transmissive optical element 14. In particular, in the case of this embodiment, the first light source unit 11, the second light source unit 12, and the third light source unit 13 are in a positional relationship rotated 90 degrees around the intersection of the optical axis AX1, the optical axis AX3, and the optical axis AX2, so that the blue light LB, the green light LG, and the red light LR are incident on different side surfaces of the transmissive optical element 14.

[0030] In this embodiment, the transmissive optical element 14 has four side surfaces 14c1, 14c2, 14c3, and 14c4, but the number of side surfaces does not necessarily have to be four, and is preferably 2×m (m: a natural number equal to or greater than 2). That is, the number of side surfaces is preferably an even number, such as six or eight. If the number of side surfaces is an even number, each of the side surfaces is parallel to the side surface facing the side surface, and there is no side surface that does not have a parallel pair. This reduces the generation of stray light in the transmissive optical element 14, and improves the light utilization efficiency.

[0031] The transmissive optical element 14 may be made of quartz. In the transmissive optical element 14, as the amount of light transmitted through the light-transmitting member increases, the amount of light absorbed by the light-transmitting member increases, and thermal distortion may occur in the light-transmitting member. In this case, the polarization direction of each color light LB, LG, and LR emitted from each light source unit 11, 12, and 13 is disturbed, and the linearly polarized light incident on the light-transmitting member becomes elliptically polarized light and is emitted from the light-transmitting member. As a result, in the projector 20, by using a laser diode for each light-emitting element, the effect of obtaining a predetermined contrast without providing an incident side polarizing plate cannot be obtained. That is, even though a laser diode is used for each light-emitting element, it becomes necessary to use an incident side polarizing plate to align the polarization direction. Therefore, in order to obtain the above effect, it is desirable to use a glass material with a small Young's modulus and a small thermal expansion coefficient as a glass material with little thermal distortion, and it is desirable to use quartz as an example.

[0032] The following describes the behavior of each color light LB, LG, LR when it passes through the transmitting optical element 14. Although the incident direction and the emission direction of each color light LB, LG, LR are different from each other, the behavior of each color light LB, LG, LR is common to each other. Therefore, here, the green light LG emitted from the second light source unit 12 will be used for the description.

[0033] 5A to 5F are schematic diagrams for explaining the behavior of the green light LG when the transmissive optical element 14 rotates. In this example, when viewed from the +Y side, the transmissive optical element 14 rotates clockwise around the rotation axis C1, and time passes from FIG. 5A to FIG. 5F.

[0034] 5A to 5F, the angle between the optical axis AX2 and a straight line M that passes through the rotation axis C1 and is perpendicular to the side surface 14c1 of the transmissive optical element 14 is defined as the rotation angle ω of the transmissive optical element 14. In reality, the green light LG has a certain luminous flux width in the Z-axis direction, but here we focus on the behavior of the light ray LG0 that travels on the optical axis AX2.

[0035] 5A shows the initial state of the transmissive optical element 14. That is, the transmissive optical element 14 is not rotated, the straight line M overlaps with the optical axis AX2, and the rotation angle ω is 0 degrees. In this case, the light ray LG0 is perpendicularly incident on the side surface 14c1, and therefore travels along the optical axis AX2 inside the transmissive optical element 14 without being refracted at the side surface 14c1. Next, the light ray LG0 is perpendicularly incident on the side surface 14c3 that is parallel to the side surface 14c1. Therefore, the light ray is emitted from the transmissive optical element 14 without being refracted at the side surface 14c3 either, and travels along the optical axis AX2.

[0036] Next, as shown in FIG. 5B, when the transmissive optical element 14 rotates by a rotation angle ω, the light ray LG0 is incident on the side surface 14c1 at an incident angle equal to the rotation angle ω. Therefore, the light ray LG0 is refracted in the direction shown in the figure (to the +Z side) and travels inside the transmissive optical element 14. Next, the light ray LG0 is also incident on the side surface 14c3 at a predetermined incident angle, so it is refracted at the side surface 14c3 and is emitted from the transmissive optical element 14. At this time, since the side surfaces 14c1 and 14c3 are parallel to each other, the incident angle of the light ray LG0 on the side surface 14c1 and the incident angle of the light ray LG0 on the side surface 14c3 are equal, and the refraction angle of the light ray LG0 incident on the side surface 14c1 and the refraction angle of the light ray LG0 emitted from the side surface 14c3 have the same absolute value but are opposite in sign. This cancels out the refraction angle of the light ray LG0 when it enters the side surface 14c1 and the refraction angle when it emerges from the side surface 14c3. As a result, the light ray LG0 travels parallel to the optical axis AX2 at a position displaced by a displacement amount d from the optical axis AX2 to the +Z side.

[0037] Next, as shown in Fig. 5C, when the rotation angle ω of the transmissive optical element 14 becomes larger than that of Fig. 5B, the angle of incidence of the light ray LG0 becomes larger, and the angle of refraction becomes larger. Therefore, the displacement amount d of the light ray LG0 from the optical axis AX2 becomes larger than that of Fig. 5B. In addition, the state in which the light ray LG0 travels parallel to the optical axis AX2 is always maintained. When the rotation angle ω is between 0 degrees and 45 degrees, the displacement amount d increases monotonically as the rotation angle ω increases.

[0038] Next, as shown in FIG. 5D, when the rotation angle ω of the transmissive optical element 14 exceeds 45 degrees, the incident surface of the light ray LG0 changes from the side surface 14c1 to the side surface 14c2. At this time, the light ray LG0 is refracted at the side surface 14c2, but the refraction direction is different from that in the period up to FIG. 5C, and it is refracted in the direction shown in the figure (-Z side). The exit surface of the light ray LG0 also changes from the side surface 14c3 to the side surface 14c4, but since the side surfaces 14c2 and 14c4 are parallel to each other, the relationship in which the refraction angle of the light ray LG0 at the time of incidence on the side surface 14c3 and the refraction angle at the time of emission from the side surface 14c4 cancel each other remains the same as in the period up to FIG. 5C. As a result, the light ray LG0 travels parallel to the optical axis AX2 at a position displaced from the optical axis AX2 to the -Z side by a displacement amount d.

[0039] Next, as shown in Fig. 5E, when the rotation angle ω of the transmissive optical element 14 becomes larger than that of Fig. 5D, the incident angle of the light ray LG0 becomes smaller, and the refraction angle becomes smaller. Therefore, the displacement amount d of the light ray LG0 from the optical axis AX2 becomes smaller than that of Fig. 5D. In this way, when the rotation angle ω is between 45 degrees and 90 degrees, the displacement amount d decreases monotonically as the rotation angle ω increases.

[0040] Next, as shown in FIG. 5F, when the rotation angle ω of the transmissive optical element 14 reaches 90 degrees, the incident surface changes from the side surface 14c1 in the initial state to the side surface 14c2, but the behavior of the light ray LG0 becomes the same as in the initial state shown in FIG. 5A.

[0041] In this way, if the entrance surface and the exit surface of the transmitting optical element 14 are parallel to each other, the traveling direction of the light ray LG0 does not change regardless of the rotation angle ω of the transmitting optical element 14, and the light ray LG0 translates in a direction parallel to the optical axis AX2 over time. When the rotation angle ω is 0 degrees, the displacement amount d of the light ray LG0 is 0, and the displacement amount d increases to either the +Z side or the -Z side when the rotation angle ω is between 0 degrees and 45 degrees. At the moment when the rotation angle ω exceeds 45 degrees, the displacement direction is reversed while the absolute value of the displacement amount d remains the same, the displacement amount d decreases when the rotation angle ω is between 45 degrees and 90 degrees, and when the rotation angle ω becomes 90 degrees, the displacement amount d becomes 0. After 90 degrees, the above behavior is repeated. Therefore, when the transmitting optical element 14 rotates once, the displacement amount d of the light ray LG0 repeats the above cycle for four periods. The displacement amount of the light ray LG0 can be appropriately set by adjusting parameters such as the refractive index and size of the transmitting optical element 14.

[0042] The behavior of light has been described above with a focus only on the light ray LG0 traveling on the optical axis AX2. In reality, however, as shown in FIG. 3, the green light LG extends linearly in the Y-axis direction perpendicular to the Z-axis direction along which the green light LG is displaced. Therefore, the green light LG is scanned within a two-dimensional illuminated area Q on the illuminated surface (light modulation device 21). Although the blue light LB and the red light LR have different emission directions from the green light LG, they are reflected by the reflecting elements 17 and 18 described later and are scanned within the two-dimensional illuminated area Q on the illuminated surface (light modulation device 21) in the same manner as the green light LG. In this way, the transmitting optical element 14 scans the blue light LB, the green light LG, and the red light LR in a direction perpendicular to the Y-axis direction when rotating around the rotation axis C1, thereby scanning within the two-dimensional illuminated area Q on the illuminated surface.

[0043] As shown in FIG. 1, the first reflecting element 17 is provided on the optical path of the blue light LB emitted from the first light source unit 11 between the first light source unit 11 and the transmitting optical element 14. The first reflecting element 17 is composed of a dichroic mirror that reflects red light and transmits blue light. Therefore, the first reflecting element 17 reflects the red light LR emitted from the transmitting optical element 14 and transmits the blue light LB emitted from the first light source unit 11. The angle formed by the first reflecting element 17 and the Z axis is referred to as the tilt angle θ1 of the first reflecting element 17. The tilt angle θ1 of the first reflecting element 17 is greater than 45 degrees.

[0044] The second reflecting element 18 is provided on the optical path of the red light LR emitted from the third light source unit 13 between the third light source unit 13 and the transmitting optical element 14. The second reflecting element 18 is composed of a dichroic mirror that reflects blue light and transmits red light. Therefore, the second reflecting element 18 reflects the blue light LB emitted from the transmitting optical element 14 and transmits the red light LR emitted from the third light source unit 13. The angle formed by the second reflecting element 18 and the Z axis is referred to as the tilt angle θ2 of the second reflecting element 18. The tilt angle θ2 of the second reflecting element 18 is greater than 45 degrees.

[0045] Since the inclination angle θ2 of the second reflecting element 18 is set to be greater than 45 degrees, the blue light LB reflected by the second reflecting element 18 travels obliquely with respect to the optical axis AX2 so as to approach the optical axis AX2. Similarly, since the inclination angle θ1 of the first reflecting element 17 is set to be greater than 45 degrees, the red light LR reflected by the first reflecting element 17 travels obliquely with respect to the optical axis AX2 so as to approach the optical axis AX2.

[0046] As a result, the blue light LB reflected by the second reflecting element 18, the green light LG emitted from the transmitting optical element 14, and the red light LR reflected by the first reflecting element 17 are incident on the first microlens array 43 in the front stage of the light modulation device 21 from different directions and overlap on the first microlens array 43, as described below. In the case of this embodiment, the incident angle of the green light LG to the first microlens array 43 is 0 degrees. In other words, the green light LG is perpendicularly incident on the first microlens array 43. The incident angle of the blue light LB to the first microlens array 43 is α1. The incident angle of the red light LR to the first microlens array 43 is α2.

[0047] The light modulation device 21 is provided on the light emission side of the light source device 10 on the optical axis AX2. The light modulation device 21 modulates each of the blue light LB, green light LG, and red light LR emitted from the light source device 10 according to image information to form image light. A transmissive liquid crystal panel is used as the light modulation device 21. The liquid crystal panel does not include a color filter. The driving method of 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.

[0048] It is preferable to consider the installation position of the optical modulation device 21 as follows. Fig. 6 is a schematic diagram showing the change in illuminance distribution when light emitted from five light-emitting elements propagates a certain distance. In Fig. 6, the horizontal axis indicates the position of the light-emitting element in a direction perpendicular to the light propagation direction, and the vertical axis indicates the propagation distance.

[0049] As shown in FIG. 6, when the light emitted from each light-emitting element is an ideal Gaussian beam, when five equally spaced light-emitting elements are turned on, the light emitted from each light-emitting element diverges according to the divergence angle as the light propagates, and the beam diameter gradually increases, causing the lights to overlap each other. Furthermore, when the light emitted from each light-emitting element has propagated a predetermined distance, the composite illuminance distribution becomes flat with almost no unevenness. Therefore, it is desirable to set the distance from each light-emitting element to the illuminated surface, that is, the distance from each light-emitting element to the light modulation device 21, so that it coincides with the distance at which the composite illuminance distribution of multiple lights becomes flat. This allows a uniform illuminance distribution to be obtained in the light modulation device 21.

[0050] FIG. 7 is a cross-sectional view of the optical modulation device 21. As shown in FIG. As shown in FIG. 7, the liquid crystal panel constituting the light modulation device 21 has a light modulation region in which a plurality of blue subpixels PX1, a plurality of green subpixels PX2, and a plurality of red subpixels PX3 are periodically arranged in a matrix. The blue subpixel PX1 modulates blue light LB. The green subpixel PX2 modulates green light LG. The red subpixel PX3 modulates red light LR. One pixel, which is the minimum unit of an image, is composed of one blue subpixel PX1, one green subpixel PX2, and one red subpixel PX3. A light-shielding film 55 called a black matrix is ​​provided between two adjacent subpixels. The blue subpixel PX1 of this embodiment corresponds to the first subpixel in the claims. The green subpixel PX2 of this embodiment corresponds to the second subpixel in the claims. The red subpixel PX3 of this embodiment corresponds to the third subpixel in the claims.

[0051] The first microlens array 43 is provided on the light incident side of the first substrate 57 constituting the liquid crystal panel. The first microlens array 43 has a configuration in which a plurality of first microlenses 431 are arranged in a matrix. The first microlens array 43 collects each of blue light, green light, and red light and guides them to the sub-pixels PX1, PX2, and PX3 of the light modulation device 21. One first microlens 431 is formed of a lenticular lens and is arranged across one pixel, that is, across three sub-pixels PX1, PX2, and PX3 of different colors aligned in one direction. In this embodiment, a lenticular lens is given as the first microlens 431, but the present invention is not limited to this, and it is also possible to adopt a microlens in which square lenses are arranged in a brick-like manner, a microlens in which lenses are arranged to correspond to sub-pixels in a delta arrangement, a microlens array with a honeycomb structure, or the like.

[0052] As described above, the blue light LB, the green light LG, and the red light LR are incident on the first microlens 431 at different incident angles, and therefore travel in different directions and are collected. As a result, the blue light LB is incident on the blue subpixel PX1, the green light LG is incident on the green subpixel PX2, and the red light LR is incident on the red subpixel PX3. That is, the first microlens array 43 causes the blue light LB emitted from the second reflecting element to be incident on the blue subpixel PX1, the green light LG emitted from the transmitting optical element to be incident on the green subpixel PX2, and the red light LR emitted from the first reflecting element to be incident on the red subpixel PX3. The first microlens array 43 in this embodiment corresponds to the light collecting element in the claims.

[0053] The second microlens array 44 is provided on the light exit side of the second substrate 58 constituting the liquid crystal panel. The second microlens array 44 has a configuration in which a plurality of second microlenses 441 are arranged in a matrix. The second microlens array 44 collimates each color light emitted from the liquid crystal panel. The second microlens 441 is provided for each sub-pixel. Note that in the present embodiment, an example has been given in which each color light is collimated after it is emitted from the liquid crystal panel, but instead of this configuration, the second microlens array 44 may be disposed on the light entrance side of the liquid crystal panel, and each color light may be collimated before it enters the liquid crystal panel.

[0054] As shown in Fig. 1, the exit side polarizing plate 22 is provided between the light modulation device 21 and the projection optical device 23 on the optical axis AX2. The exit side polarizing plate 22 transmits linearly polarized light in a specific direction emitted from the light modulation device 21 toward the projection optical device 23. In the case of this embodiment, since a laser diode is used for each light emitting element, linearly polarized light is emitted from the light source device 10. Therefore, an entrance side polarizing plate provided on the light entrance side of the light modulation device 21 is not necessary. Of course, an entrance side polarizing plate may be provided to improve contrast.

[0055] The projection optical device 23 is composed of a plurality of lenses. The projection optical device 23 enlarges and projects the image light modulated by the light modulation device 21 onto a projection surface such as a screen. As a result, an image is displayed on the projection surface.

[0056] [Effects of the first embodiment] The light source device 10 of this embodiment includes a first light source unit 11 that emits blue light LB, a second light source unit 12 that emits green light LG, a third light source unit 13 that emits red light LR, and a transmissive optical element 14 that is made of a rotatably supported light-transmitting member and transmits the color lights LB, LG, and LR. The transmissive optical element 14 is rotatable about a rotation axis C1 that extends along the Y-axis direction. The cross-sectional shapes perpendicular to the principal rays of the blue light LB emitted from the first light source unit 11, the green light LG emitted from the second light source unit 12, and the red light LR emitted from the third light source unit 13 have a long axis that extends along the Y-axis direction. The blue light LB is incident on a first position P1 of the transmissive optical element 14. The green light LG is incident on a second position P2 of the transmissive optical element 14. The red light LR is incident on a third position P3 of the transmissive optical element 14. In the transmissive optical element 14, an incident surface onto which the blue light LB, green light LG, and red light LR are incident and an exit surface from which the blue light LB, green light LG, and red light LR incident from the incident surface exit are parallel to each other.

[0057] The projector 20 of this embodiment comprises a light source device 10, an optical modulation device 21 that modulates the blue light LB, green light LG, and red light LR emitted from the transmissive optical element 14 of the light source device 10 based on image information, and a projection optical device 23 that projects the light modulated by the optical modulation device 21.

[0058] When a polygon mirror is used as a means for scanning light as in conventional light source devices, the polygon mirror rotates to reflect light, so the angle of incidence of light incident on the illuminated surface changes over time. Therefore, even if the light incident on the polygon mirror is parallel, the light emitted from the polygon mirror becomes divergent light, so it is extremely difficult to make the light always perpendicular to the illuminated surface. Therefore, in conventional projectors equipped with polygon mirrors, there is a risk of a decrease in brightness and contrast in the light modulation device, the occurrence of color unevenness, a loss of light in the projection optical device, etc., resulting in a decrease in the image quality of the projector.

[0059] In response to the above problem, according to the light source device 10 of the present embodiment, as shown in Figs. 5A to 5F, the blue light LB, the green light LG, and the red light LR are displaced in a direction perpendicular to the traveling direction of each of the colored lights LB, LG, and LR while maintaining a state parallel to the corresponding optical axes AX1, AX2, and AX3 of the colored lights LB, LG, and LR as the transmissive optical element 14 rotates. In addition, since each of the colored lights LB, LG, and LR has an elongated shape having a major axis along the extending direction of the rotation axis C1, each of the colored lights LB, LG, and LR can be scanned in a two-dimensional illumination area Q on an arbitrary illumination surface, specifically, in the light modulation area of ​​the light modulation device 21. As a result, the decrease in brightness and contrast in the light modulation device 21, the occurrence of color unevenness, and the loss of light in the projection optical device 23 are suppressed, and the projector 20 with excellent display quality can be realized with a simple configuration.

[0060] The projector 20 of the present embodiment further includes a first reflecting element 17 that reflects the red light LR emitted from the transmissive optical element 14, a second reflecting element 18 that reflects the blue light LB emitted from the transmissive optical element 14, and a first microlens array 43 that collects and guides the blue light LB reflected by the second reflecting element 18, the green light LG emitted from the transmissive optical element 14, and the red light LR reflected by the first reflecting element 17 to the light modulation device 21. The blue light LB reflected by the second reflecting element 18, the green light LG emitted from the transmissive optical element 14, and the red light LR reflected by the first reflecting element 17 are incident on the first microlens array 43 from different directions. The light modulation device 21 has a blue subpixel PX1 that modulates the blue light LB, a green subpixel PX2 that modulates the green light LG, and a red subpixel PX3 that modulates the red light LR. The first microlens array 43 causes blue light LB emitted from the second reflecting element 18 to be incident on the blue sub-pixel PX1, causes green light LG emitted from the transmissive optical element 14 to be incident on the green sub-pixel PX2, and causes red light LR emitted from the first reflecting element 17 to be incident on the red sub-pixel PX3.

[0061] The projector 20 of this embodiment includes three light-emitting elements 25, 26, and 27 that emit light of different colors, and the three color lights LB, LG, and LR are spatially separated by the arrangement of the reflecting elements 17 and 18 and the action of the first microlens array 43, and each of the color lights LB, LG, and LR can be incident on the corresponding sub-pixels PX1, PX2, and PX3. This makes it possible to realize the projector 20 that can display a color image without using a color filter in the light modulation device 21. In addition, the two-dimensional light modulation device 21 can be illuminated by scanning the color lights LB, LG, and LR, each of which has a major axis in the Y-axis direction, in the Z-axis direction, so that only one transmissive optical element is required, and the device configuration can be simplified and made smaller.

[0062] This type of projector is designed on the premise that the angle of incidence of each color light to the first microlens array is always constant. However, when a polygon mirror is used as a means for scanning light as in conventional light source devices, the polygon mirror rotates to reflect light, so that the angle of incidence of each color light that enters the first microlens array through each reflecting element changes over time. In this case, a problem may occur in that a specific color light enters an adjacent sub-pixel that does not correspond to that color light, thereby reducing the color purity of the displayed image. In addition, a problem may occur in that the amount of light that enters the black matrix of the liquid crystal panel increases, reducing the brightness of the displayed image.

[0063] To address the above problem, according to the projector 20 of this embodiment, the color lights LB, LG, and LR emitted from the transmissive optical element 14 become substantially parallel lights, so there is very little change over time in the angle of incidence of the color lights LB, LG, and LR to the first microlens array 43. This reduces the rate at which a specific color light is incident on an adjacent sub-pixel or black matrix that does not correspond to that color light, making it possible to suppress deterioration in color purity and brightness of the displayed image.

[0064] Furthermore, even if the color lights LB, LG, and LR are coherent laser lights, the color lights LB, LG, and LR are superimposed in time by scanning them two-dimensionally at high speed on the light modulation device 21. This makes it possible to suppress uneven illuminance caused by using a coherent light source.

[0065] Furthermore, according to this embodiment, it is possible to illuminate a substantially rectangular shape without using an optical system for shaping light into a rectangular shape, such as a multi-lens, etc. Therefore, it is possible to relatively shorten the overall optical path length, and by reducing the number of optical components, it is possible to reduce the number of interfaces between the optical system and air, thereby reducing the loss of light due to interface reflection.

[0066] Since the light source device 10 of this embodiment is a scanning type illumination device, it is also possible to turn off each of the light emitting elements 25, 26, 27 when each color light reaches an area in the light modulation area where black is to be displayed. This enables a method of illuminating only areas other than the black display, that is, so-called area illumination, and can sufficiently improve the efficiency of the emitted light intensity relative to the input power compared to the conventional non-scanning type illumination method. Accordingly, the light absorbed by the emission side polarizing plate 22 during black display is reduced, and the load on the emission side polarizing plate 22 can be reduced. This can be expected to have effects such as improved reliability of the emission side polarizing plate 22 and improved contrast by adopting a polarizing plate made of an organic material.

[0067] [Second embodiment] A second embodiment of the present invention will now be described with reference to FIG. The basic configuration of the projector of this embodiment is similar to that of the first embodiment, but the arrangement of some of the light source units is different from that of the first embodiment. FIG. 8 is a schematic configuration diagram of a projector 30 according to the present embodiment. In FIG. 8, components common to those in the first embodiment are given the same reference numerals, and description thereof will be omitted.

[0068] As shown in FIG. 8, a projector 30 of the present embodiment includes a light source device 40, a light modulation device 21, an exit side polarizing plate 22, and a projection optical device .

[0069] The light source device 40 of this embodiment includes a first light source section 11, a second light source section 12, a third light source section 13, a transmissive optical element 14, a rotary drive device 15, a first reflecting element 17, and a second reflecting element 18.

[0070] In the first embodiment, the optical axis AX1 of the first light source unit 11 and the optical axis AX3 of the third light source unit 13 are each perpendicular to the optical axis AX2 of the second light source unit 12. In contrast, in this embodiment, the first light source unit 11 is disposed at a position rotated counterclockwise from a position where the optical axis AX1 is perpendicular to the optical axis AX2. The third light source unit 13 is disposed at a position rotated clockwise from a position where the optical axis AX3 is perpendicular to the optical axis AX2.

[0071] In this embodiment, as described above, the position of the first light source unit 11 has been changed from that in the first embodiment, and therefore the first reflecting element 17 is located at a position that is off the optical path of the blue light LB emitted from the first light source unit 11. In this case, the first reflecting element 17 may be configured as a dichroic mirror that reflects red light and transmits blue light as in the first embodiment, or may be configured as a mirror that reflects incident light regardless of the wavelength band. In addition, the position of the third light source unit 13 has been changed from that in the first embodiment, and therefore the second reflecting element 18 is located at a position that is off the optical path of the red light LR emitted from the third light source unit 13. In this case, the second reflecting element 18 may be configured as a dichroic mirror that reflects blue light and transmits red light as in the first embodiment, or may be configured as a mirror that reflects incident light regardless of the wavelength band.

[0072] The inclination angle θ3 of the first reflecting element 17 is greater than 45 degrees and smaller than the inclination angle θ1 of the first reflecting element 17 in the first embodiment. The inclination angle θ4 of the second reflecting element 18 is greater than 45 degrees and smaller than the inclination angle θ2 of the second reflecting element 18 in the first embodiment. The other configurations of the projector 30 are similar to those of the first embodiment.

[0073] [Effects of the second embodiment] In this embodiment, too, the problems of reduced brightness and contrast in the light modulation device 21, the occurrence of color unevenness, light loss in the projection optical device 23, and uneven illuminance due to the use of a coherent light source can be improved; by reducing the number of optical components, the number of interfaces between the optical system and the air can be reduced, thereby reducing light loss due to interface reflection; light utilization efficiency can be improved without using an optical system to shape light into a rectangle; area lighting is possible; color display is possible with a simple configuration without using a color filter, and deterioration in color purity and brightness of the displayed image can be suppressed, thereby obtaining the same effects as in the first embodiment.

[0074] In a projector in which each color light is distributed to the corresponding sub-pixels by a microlens disposed in front of a light modulation device, it is important to precisely adjust the incidence angle of each color light to the microlens in order to improve the quality of the displayed image. In addition, due to factors such as the processing limit of the microlens, it may be difficult to freely set the incidence angle of each color light. In response to these issues, in the case of this embodiment, as described above, the arrangement of the first light source unit 11 and the third light source unit 13 and the inclination angles θ3, θ4 of the reflecting elements 17, 18 are changed from those of the first embodiment, so that the incidence angle α3 of the blue light LB to the first microlens array 43 can be made smaller than the incidence angle α1 of the blue light LB in the first embodiment. In addition, the incidence angle α4 of the red light LR to the first microlens array 43 can be made smaller than the incidence angle α2 of the red light LR in the first embodiment. In this way, the configuration of this embodiment is suitable when it is desired to relatively reduce the incidence angle of the color light obliquely incident on the first microlens array 43.

[0075] In addition, instead of the configuration of this embodiment, even if the arrangement of the first light source unit 11 and the third light source unit 13 remains the same as in the first embodiment, the inclination angles θ1, θ2 of the reflection elements 17, 18 can be made smaller than in the first embodiment and the distance between the light modulation device 21 and the reflection elements 17, 18 can be increased to reduce the angles of incidence of the blue light LB and the red light LR to the first microlens array 43. In this case, even if the actual distance from each of the light emitting elements 25, 26, 27 to the light modulation device 21 becomes longer than the shortest distance at which the illuminance distribution has a flat shape, a flat-top illuminance distribution can be obtained.

[0076] [Third embodiment] A third embodiment of the present invention will be described below with reference to FIGS. The basic configuration of the projector of this embodiment is similar to that of the first embodiment, but the configuration of each light source unit is different from that of the first embodiment. Fig. 9 is a plan view showing a schematic configuration of a projector 50 of this embodiment. Fig. 10 is a side view showing a schematic configuration of a projector 50 of this embodiment. 9 and 10, components common to those in the drawings of the first embodiment are given the same reference numerals, and description thereof will be omitted.

[0077] As shown in FIGS. 9 and 10, a projector 50 of this embodiment includes a light source device 60, a light modulation device 21, an exit-side polarizing plate 22, and a projection optical device .

[0078] The light source device 60 of this embodiment includes a first light source unit 61, a second light source unit 62, a third light source unit 63, a transmissive optical element 14, a rotary drive device 15, a first reflecting element 17, and a second reflecting element 18.

[0079] The second light source unit 62 includes one second light emitting element 26 and a second light beam width adjustment optical system 66. The second light beam width adjustment optical system 66 is composed of a cylindrical concave lens 661 and a cylindrical convex lens 662. The cylindrical concave lens 661 has no power in the Z-axis direction and has negative power in the Y-axis direction. The cylindrical convex lens 662 has no power in the Z-axis direction and has positive power in the Y-axis direction. As a result, the second light beam width adjustment optical system 66 expands the light beam width in the Y-axis direction of the green light LG0 emitted from the second light emitting element 26.

[0080] The configurations of the first light source unit 61 and the third light source unit 63 are the same as that of the second light source unit 62. That is, the first light source unit 61 includes one first light emitting element 25 and a first light beam width adjustment optical system 65. The first light beam width adjustment optical system 65 includes a cylindrical concave lens 651 and a cylindrical convex lens 652. The third light source unit 63 includes one third light emitting element 27 and a third light beam width adjustment optical system 67. The third light beam width adjustment optical system 67 includes a cylindrical concave lens 671 and a cylindrical convex lens 672. The color lights LB, LG, and LR emitted from the light beam width adjustment optical systems 65, 66, and 67 are parallel lights whose light beam widths in the Y-axis direction are expanded. That is, each of the first light beam width adjustment optical system 65, the second light beam width adjustment optical system 66, and the third light beam width adjustment optical system 67 is an afocal optical system including a cylindrical lens. The other configuration of the projector 50 is similar to that of the first embodiment.

[0081] [Effects of the third embodiment] In this embodiment, too, the problems of reduced brightness and contrast in the light modulation device 21, the occurrence of color unevenness, light loss in the projection optical device 23, and uneven illuminance due to the use of a coherent light source can be improved; by reducing the number of optical components, the number of interfaces between the optical system and the air can be reduced, thereby reducing light loss due to interface reflection; light utilization efficiency can be improved without using an optical system to shape light into a rectangle; area lighting is possible; color display is possible with a simple configuration without using a color filter, and deterioration in color purity and brightness of the displayed image can be suppressed, thereby obtaining the same effects as in the first embodiment.

[0082] In the present embodiment, since the first light source unit 61, the second light source unit 62, and the third light source unit 63 each include the light beam width adjusting optical systems 65, 66, and 67, by appropriately setting the power in the Y-axis direction of the light beam width adjusting optical systems 65, 66, and 67, regardless of the number of light-emitting elements, the light beam width in the Y-axis direction of each of the color lights LB, LG, and LR can be adjusted to match the size of the light modulation device 21. In addition, since the light beam width adjusting optical systems 65, 66, and 67 are afocal optical systems, the installation position in the X-axis direction of the light modulation device 21 can be freely set.

[0083] [Fourth embodiment] A fourth embodiment of the present invention will be described below with reference to FIGS. The basic configuration of the projector of this embodiment is similar to that of the third embodiment, but the configuration of the light flux width adjusting optical system is different from that of the third embodiment. Fig. 11 is a plan view showing a schematic configuration of the projector 70. Fig. 12 is a side view showing a schematic configuration of the projector 70. 11 and 12, components common to those in the first embodiment are given the same reference numerals, and description thereof will be omitted.

[0084] As shown in FIGS. 11 and 12, a projector 70 of this embodiment includes a light source device 80, a light modulation device 21, an exit-side polarizing plate 22, and a projection optical device 23.

[0085] The light source device 80 of this embodiment includes a first light source unit 81, a second light source unit 82, a third light source unit 83, a transmissive optical element 14, a rotary drive device 15, a first reflecting element 17, and a second reflecting element 18.

[0086] The second light source unit 82 includes one second light emitting element 26 and a second light beam width adjustment optical system 86. The second light beam width adjustment optical system 86 is composed of one meniscus lens. The meniscus lens has a concave surface on the light incident side and a convex surface on the light exit side. The meniscus lens has no power in the Z-axis direction and has power in the Y-axis direction. As a result, the second light beam width adjustment optical system 86 expands the light beam width in the Y-axis direction of the green light LG0 emitted from the second light emitting element 26. In addition, the green light LG emitted from the second light beam width adjustment optical system 86 is a parallel light with an expanded light beam width in the Y-axis direction.

[0087] The configurations of the first light source unit 81 and the third light source unit 83 are similar to the configuration of the second light source unit 82. That is, the first light source unit 81 includes one first light-emitting element 25 and a first light beam width adjustment optical system 85. The first light beam width adjustment optical system 85 is composed of one meniscus lens. The third light source unit 83 includes one third light-emitting element 27 and a third light beam width adjustment optical system 87. The third light beam width adjustment optical system 87 is composed of one meniscus lens. The other configuration of the projector 70 is similar to that of the first embodiment.

[0088] [Effects of the fourth embodiment] In this embodiment, too, the problems of reduced brightness and contrast in the light modulation device 21, the occurrence of color unevenness, light loss in the projection optical device 23, and uneven illuminance due to the use of a coherent light source can be improved; by reducing the number of optical components, the number of interfaces between the optical system and the air can be reduced, thereby reducing light loss due to interface reflection; light utilization efficiency can be improved without using an optical system to shape light into a rectangle; area lighting is possible; color display is possible with a simple configuration without using a color filter, and deterioration in color purity and brightness of the displayed image can be suppressed, thereby obtaining the same effects as in the first embodiment.

[0089] Furthermore, by using each light beam width adjustment optical system 85, 86, 87, the light beam width in the Y-axis direction of each color light LB, LG, LR can be adjusted to match the size of the light modulation device 21 regardless of the number of light-emitting elements, and the installation position in the X-axis direction of the light modulation device 21 can be freely set, thereby obtaining the same effects as in the third embodiment.

[0090] [Fifth embodiment] Hereinafter, a fifth embodiment of the present invention will be described with reference to FIGS. The basic configuration of the projector of this embodiment is similar to that of the first embodiment, but the configuration of the light source device is different from that of the third embodiment. FIG. 13 is a plan view showing a schematic configuration of a projector 90 of the present embodiment. In FIG. 13, components common to those in the first embodiment are given the same reference numerals, and description thereof will be omitted.

[0091] As shown in FIG. 13, a projector 90 of this embodiment includes a light source device 100, a light modulation device 21, an exit side polarizing plate 22, and a projection optical device .

[0092] The light source device 100 of this embodiment includes a first light source section 11, a second light source section 12, a third light source section 13, a transmissive optical element 14, a rotary drive device 15, a light combining element 91, a third reflecting element 93, and a fourth reflecting element 94.

[0093] In this embodiment, the blue light LB emitted from the first light source unit 11, the green light LG emitted from the second light source unit 12, and the red light LR emitted from the third light source unit 13 are directly incident on the transmissive optical element 14 without passing through a reflecting element or the like. The first light source unit 11 rotates counterclockwise from the position of the second light source unit 12 and is disposed at a position tilted toward the +Z side with respect to the optical axis AX2. The third light source unit 13 rotates clockwise from the position of the second light source unit 12 and is disposed at a position tilted toward the -Z side with respect to the optical axis AX2.

[0094] By arranging the light source units 11, 12, and 13 as described above, the blue light LB, the green light LG, and the red light LR are incident on different positions of the transmissive optical element 14. Specifically, the blue light LB is incident on a first position P1 of the transmissive optical element 14. The green light LG is incident on a second position P2 different from the first position P1 of the transmissive optical element 14. The red light LR is incident on a third position P3 different from the first position P1 and the second position P2 of the transmissive optical element 14.

[0095] The light combining element 91 is provided between the transmissive optical element 14 and the light modulation device 21 on the optical axis AX2. The light combining element 91 has a configuration in which a dichroic film that transmits green light and red light and reflects blue light and a dichroic film that transmits green light and blue light and reflects red light cross in an X-shape. The light combining element 91 combines the blue light LB emitted from the transmissive optical element 14, the green light LG emitted from the transmissive optical element 14, and the red light LR emitted from the transmissive optical element 14. Each of the blue light LB, green light LG, and red light LR combined by the light combining element 91 is perpendicularly incident on the light modulation device 21.

[0096] The third reflecting element 93 reflects the blue light LB emitted from the transmitting optical element 14 toward the light combining element 91. The fourth reflecting element 94 reflects the red light LR emitted from the transmitting optical element 14 toward the light combining element 91. It is desirable that the angles of the third reflecting element 93 and the fourth reflecting element 94 are set so that the blue light LB and the red light LR are each perpendicularly incident on the light combining element 91.

[0097] FIG. 14 is a schematic diagram showing how three color lights are scanned on the light modulation device 21. As shown in FIG. As described above, the blue light LB, green light LG, and red light LR are incident on the transmitting optical element 14 at different positions P1, P2, and P3, respectively, and are therefore emitted from the transmitting optical element 14 in different phases. As a result, the blue light LB, green light LG, and red light LR do not overlap with each other in the same region when illuminating the optical modulation device 21, and are scanned in the Z-axis direction over time while illuminating band-shaped regions extending in the Y-axis direction at intervals from each other, as shown in Fig. 14.

[0098] In this way, the blue light LB forms a strip-shaped first illuminated region 21B having a major axis in the Y-axis direction on the light modulation device 21. The green light LG forms a strip-shaped second illuminated region 21G having a major axis in the Y-axis direction on the light modulation device 21. The red light LR forms a strip-shaped third illuminated region 21R having a major axis in the Y-axis direction on the light modulation device 21. Each of the first illuminated region 21B, the second illuminated region 21G, and the third illuminated region 21R is scanned in the Z-axis direction on the light modulation device 21 as the transmissive optical element 14 rotates.

[0099] A control unit (not shown) vertically scans the blue partial image, the green partial image, and the red partial image, which are obtained by dividing the entire image into strips, in synchronization with the scanning of the first illuminated region 21B, the second illuminated region 21G, and the third illuminated region 21R. As a result, the light modulation device 21 modulates different color lights LB, LG, and LR for each of the illuminated regions 21B, 21G, and 21R. That is, the light modulation device 21 modulates the blue light LB in the first illuminated region 21B, modulates the green light LG in the second illuminated region 21G, and modulates the red light LR in the third illuminated region 21R, and a full-color image is formed by scanning each of the illuminated regions 21B, 21G, and 21R in the Z-axis direction. The other configuration of the projector 90 is similar to that of the first embodiment.

[0100] [Effects of the fifth embodiment] In this embodiment, too, the problems of reduced brightness and contrast in the light modulation device 21, the occurrence of color unevenness, light loss in the projection optical device 23, and uneven illuminance due to the use of a coherent light source can be improved; by reducing the number of optical components, the number of interfaces between the optical system and the air can be reduced, thereby reducing light loss due to interface reflection; light utilization efficiency can be improved without using an optical system to shape light into a rectangle; area lighting is possible; color display is possible with a simple configuration without using a color filter, and deterioration in color purity and brightness of the displayed image can be suppressed, thereby obtaining the same effects as in the first embodiment.

[0101] Unlike the previous embodiments, this embodiment is not a projector that makes three color lights incident on one microlens from different directions and spatially separates them, so that all of the color lights LB, LG, and LR can be made to be perpendicularly incident on the light modulation device 21. In this case, according to this embodiment, the state in which the blue light LB, the green light LG, and the red light LR are each perpendicularly incident on the light modulation device 21 is always maintained. This makes it possible to stably obtain images with excellent display quality such as contrast and color reproducibility.

[0102] [Sixth embodiment] Hereinafter, a sixth embodiment of the present invention will be described with reference to FIG. The basic configuration of the projector of this embodiment is similar to that of the first embodiment, but the configuration of the light source device is different from that of the first embodiment. FIG. 15 is a plan view showing a schematic configuration of a projector 110 of the present embodiment. In FIG. 15, components common to those in the first embodiment are given the same reference numerals, and description thereof will be omitted.

[0103] As shown in FIG. 15, a projector 110 of this embodiment includes a light source device 120, a light modulation device 21, an exit side polarizing plate 22, and a projection optical device .

[0104] The light source device 120 of this embodiment includes a light source unit 122, a transmissive optical element 14, a rotary drive unit 15, a light separation element 123, a fifth reflecting element 125, and a sixth reflecting element 126. The light source unit 122 includes a first light source unit 11, a second light source unit 12, a third light source unit 13, and a light combining optical system 127.

[0105] The first light source unit 11 is disposed such that the optical axis AX1 of the first light source unit 11 is perpendicular to the optical axis AX2 of the second light source unit 12. The third light source unit 13 is disposed such that the optical axis AX3 of the third light source unit 13 is perpendicular to the optical axis AX2 of the second light source unit 12. The first light source unit 11 emits blue light LB toward the -Z side. The third light source unit 13 emits red light LR toward the -Z side. The second light source unit 12 emits green light LG toward the +X side. In this example, the first light source unit 11 is disposed closer to the second light source unit 12, and the third light source unit 13 is disposed farther from the second light source unit 12, but the opposite may be true.

[0106] The light combining optical system 127 includes a first light combining element 113 and a second light combining element 114. The first light combining element 113 is provided at a position where the optical axis AX1 and the optical axis AX2 intersect. The first light combining element 113 is composed of a dichroic mirror that transmits green light and reflects blue light. The second light combining element 114 is provided at a position where the optical axis AX2 and the optical axis AX3 intersect. The second light combining element 114 is composed of a dichroic mirror that transmits green light and blue light and reflects red light. The light combining optical system 127 combines the blue light LB emitted from the first light source unit 11, the green light LG emitted from the second light source unit 12, and the red light LR emitted from the third light source unit 13 to generate white light LW. As a result, the light source unit 122 emits white light LW. The white light LW is incident on the transmitting optical element 14 without being separated by wavelength band.

[0107] The light separation element 123 is provided between the transmissive optical element 14 and the light modulation device 21 on the optical axis AX2. The light separation element 123 has a configuration in which a dichroic film that transmits green light and red light and reflects blue light and a dichroic film that transmits green light and blue light and reflects red light cross in an X-shape. The light separation element 123 separates the white light LW emitted from the transmissive optical element 14 into blue light LB, green light LG, and red light LR. The blue light LB is emitted from the transmissive optical element 14 toward the -Z side. The red light LR is emitted from the transmissive optical element 14 toward the +Z side. The green light LG is emitted from the transmissive optical element 14 toward the +X side and enters the light modulation device 21.

[0108] The fifth reflecting element 125 is provided on the optical path of the blue light LB emitted from the transmitting optical element 14 toward the -Z side. The fifth reflecting element 125 reflects the blue light LB emitted from the transmitting optical element 14 toward the -Z side and makes it incident on the light modulation device 21. The sixth reflecting element 126 is provided on the optical path of the red light LR emitted from the transmitting optical element 14 toward the +Z side. The sixth reflecting element 126 reflects the red light LR emitted from the transmitting optical element 14 toward the +Z side and makes it incident on the light modulation device 21. The inclination angle θ5 of the fifth reflecting element 125 and the inclination angle θ6 of the sixth reflecting element 126 are both set to be greater than 45 degrees.

[0109] The blue light LB reflected by the fifth reflecting element 125 travels obliquely with respect to the optical axis AX2 so as to approach the optical axis AX2. The red light LR reflected by the sixth reflecting element 126 travels obliquely with respect to the optical axis AX2 so as to approach the optical axis AX2. As a result, the blue light LB reflected by the fifth reflecting element 125, the green light LG emitted from the transmitting optical element 14, and the red light LR reflected by the sixth reflecting element 126 are incident on the first microlens array 43 (see FIG. 7) at the front stage of the light modulation device 21 from different directions and overlap on the first microlens array 43. The other configuration of the projector 110 is similar to that of the first embodiment.

[0110] [Effects of the sixth embodiment] In this embodiment, too, the problems of reduced brightness and contrast in the light modulation device 21, the occurrence of color unevenness, light loss in the projection optical device 23, and uneven illuminance due to the use of a coherent light source can be improved; by reducing the number of optical components, the number of interfaces between the optical system and the air can be reduced, thereby reducing light loss due to interface reflection; light utilization efficiency can be improved without using an optical system to shape light into a rectangle; area lighting is possible; color display is possible with a simple configuration without using a color filter, and deterioration in color purity and brightness of the displayed image can be suppressed, thereby obtaining the same effects as in the first embodiment.

[0111] [Seventh embodiment] The seventh embodiment of the present invention will be described below with reference to FIG. The basic configuration of the projector of this embodiment is similar to that of the sixth embodiment, but the configuration of the light source unit is different from that of the sixth embodiment. FIG. 16 is a plan view showing a schematic configuration of a projector 130 of the present embodiment. In FIG. 16, components common to those in FIG. 15 of the sixth embodiment are given the same reference numerals, and description thereof will be omitted.

[0112] As shown in FIG. 16, a projector 130 of this embodiment includes a light source device 140, a light modulation device 21, an exit side polarizing plate 22, and a projection optical device .

[0113] The light source device 140 of this embodiment includes a light source unit 142, a transmissive optical element 14, a rotary drive unit 15, a light separation element 123, a fifth reflecting element 125, and a sixth reflecting element 126. The light source unit 142 includes a first light source unit 11, a second light source unit 12, a third light source unit 13, and a light combining element 145.

[0114] The first light source unit 11 emits blue light LB toward the -Z side. The second light source unit 12 emits green light LG toward the +X side. The third light source unit 13 emits red light LR toward the +Z side. The first light source unit 11 and the third light source unit 13 are disposed opposite each other on the same axis.

[0115] The light combining element 145 is provided at a position where the optical axis AX1 and the optical axis AX3 intersect with the optical axis AX2. The light combining element 145 has a configuration in which a dichroic film that transmits green light and red light and reflects blue light and a dichroic film that transmits green light and blue light and reflects red light intersect in an X-shape. The light combining element 145 combines the blue light LB emitted from the first light source unit 11, the green light LG emitted from the second light source unit 12, and the red light LR emitted from the third light source unit 13, and emits white light LW. The white light LW is incident on the transmitting optical element 14 without being separated by wavelength band. The other configuration of the projector 130 is similar to that of the sixth embodiment.

[0116] [Effects of the Seventh Embodiment] In this embodiment, too, the problems of reduced brightness and contrast in the light modulation device 21, the occurrence of color unevenness, light loss in the projection optical device 23, and uneven illuminance due to the use of a coherent light source can be improved; by reducing the number of optical components, the number of interfaces between the optical system and the air can be reduced, thereby reducing light loss due to interface reflection; light utilization efficiency can be improved without using an optical system to shape light into a rectangle; area lighting is possible; color display is possible with a simple configuration without using a color filter, and deterioration in color purity and brightness of the displayed image can be suppressed, thereby obtaining the same effects as in the first embodiment.

[0117] [Eighth embodiment] Hereinafter, an eighth embodiment of the present invention will be described with reference to FIG. The basic configuration of the light source device of this embodiment is similar to that of the sixth embodiment, but the configuration of the projector and the light emitted from the light source device are different from those of the sixth embodiment. FIG. 17 is a plan view showing a schematic configuration of a projector 150 of the present embodiment. In FIG. 17, components common to those in the sixth embodiment are given the same reference numerals, and the description thereof will be omitted.

[0118] 17, the projector 150 of this embodiment includes a light source device 160, a light modulation device 21, an emission-side polarizing plate 22, and a projection optical device 23. The difference between the light source device 160 of this embodiment and the light source device of the sixth embodiment is that while the light source device of the sixth embodiment emits white light LW, the light source device 160 emits each color light in a time-division manner.

[0119] The light source device 160 of this embodiment includes a light source unit 122, a transmissive optical element 14, and a rotary drive device 15. The light source unit 122 includes a first light source unit 11, a second light source unit 12, a third light source unit 13, and a light combining optical system 127.

[0120] The first light source unit 11 is disposed such that the optical axis AX1 of the first light source unit 11 is perpendicular to the optical axis AX2 of the second light source unit 12. The third light source unit 13 is disposed such that the optical axis AX3 of the third light source unit 13 is perpendicular to the optical axis AX2 of the second light source unit 12. The first light source unit 11 emits blue light LB toward the -Z side. The third light source unit 13 emits red light LR toward the -Z side. The second light source unit 12 emits green light LG toward the +X side. In this example, the first light source unit 11 is disposed closer to the second light source unit 12, and the third light source unit 13 is disposed farther from the second light source unit 12, but the opposite may be true.

[0121] The light combining optical system 127 includes a first light combining element 113 and a second light combining element 114. The first light combining element 113 is provided at a position where the optical axis AX1 and the optical axis AX2 intersect. The first light combining element 113 is composed of a dichroic mirror that transmits green light and reflects blue light. The second light combining element 114 is provided at a position where the optical axis AX2 and the optical axis AX3 intersect. The second light combining element 114 is composed of a dichroic mirror that transmits green light and blue light and reflects red light.

[0122] In this embodiment, the blue light LB, red light LR, and green light LG are emitted from the transmitting optical element 14 toward the +X side and enter the light modulation device 21 in a time-division manner. As a result, the blue light LB, green light LG, and red light LR do not overlap with each other in the same region when illuminating the light modulation device 21, and each color light is scanned in the Z-axis direction in a time-division manner while illuminating a strip-shaped region extending in the Y-axis direction.

[0123] In the present embodiment, first, on the light modulation device 21, the blue light LB having a major axis in the Y-axis direction forms a first illuminated region, and is scanned in the Z-axis direction on the light modulation device 21 as the transmitting optical element 14 rotates. Next, the red light LR having a major axis in the Y-axis direction forms a second illuminated region, and is scanned in the Z-axis direction on the light modulation device 21 as the transmitting optical element 14 rotates. Finally, the green light LG having a major axis in the Y-axis direction forms a third illuminated region, and is scanned in the Z-axis direction on the light modulation device 21 as the transmitting optical element 14 rotates. In this way, each color light is illuminated and scanned in a time-division manner on the light modulation device 21. In this embodiment, illumination is scanned on the light modulation device 21 in the order of the blue light LB, the red light LR, and the green light LG, but this is not limited to this.

[0124] In this embodiment, a control unit (not shown) vertically scans the blue partial image, the green partial image, and the red partial image in synchronization with the scanning of the first illuminated region, the second illuminated region, and the third illuminated region. As a result, the light modulation device 21 modulates different color lights LB, LG, and LR for each illuminated region. That is, the light modulation device 21 modulates blue light LB in the first illuminated region, modulates green light LG in the second illuminated region, and modulates red light LR in the third illuminated region, and each illuminated region is scanned in the Z-axis direction to form a full-color image.

[0125] In addition, the timing of each of the first light emitting element 25, the second light emitting element 26, and the third light emitting element 27 emitting light will be described. The first light emitting element 25 emits light from the time when the incidence of light is switched from the side surface 14c4 to the side surface 14c1 with the rotation of the transmissive optical element 14 until the time when the incidence of light is switched from the side surface 14c1 to the side surface 14c2 with the rotation of the transmissive optical element 14. Next, the second light emitting element 26 emits light from the time when the incidence of light is switched from the side surface 14c1 to the side surface 14c2 with the rotation of the transmissive optical element 14 until the time when the incidence of light is switched from the side surface 14c2 to the side surface 14c3 with the rotation of the transmissive optical element 14. Finally, the third light emitting element 27 emits light from the time when the incidence of light is switched from the side surface 14c2 to the side surface 14c3 with the rotation of the transmissive optical element 14 until the time when the incidence of light is switched from the side surface 14c3 to the side surface 14c4. By repeating this, the first light emitting element 25, the second light emitting element 26 and the third light emitting element 27 emit the respective color lights in a time-division manner.

[0126] [Effects of the eighth embodiment] In this embodiment as well, the problems of reduced brightness and contrast in the light modulation device 21, the occurrence of color unevenness, light loss in the projection optical device 23, and uneven illuminance due to the use of a coherent light source can be improved; by reducing the number of optical components, the number of interfaces between the optical system and the air can be reduced, thereby reducing light loss due to interface reflection; light utilization efficiency can be improved without using an optical system to shape light into a rectangle; area lighting is possible; color display is possible with a simple configuration without using a color filter, and deterioration in color purity and brightness of the displayed image can be suppressed.

[0127] In addition, in the case of the present embodiment, since the projector is not a type that makes three color lights incident on one microlens from different directions and spatially separates them, all of the color lights LB, LG, and LR can be made to be perpendicularly incident on the light modulation device 21. In this case, according to the present embodiment, the state in which each of the blue light LB, the green light LG, and the red light LR is perpendicularly incident on the light modulation device 21 is always maintained. This makes it possible to stably obtain images with excellent display quality such as contrast and color reproducibility. In addition, by configuring the color lights to be emitted in a time-division manner, the amount of light incident on the transmissive optical element 14 can be reduced compared to the case in which three color lights are incident on the transmissive optical element 14 at once, so that the temperature rise of the optical element can be suppressed and the influence of thermal distortion can be suppressed.

[0128] 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, one aspect of the present invention can be a configuration in which the characteristic portions of the above-described embodiments are appropriately combined.

[0129] In the light source device of the above embodiment, the shape of the transmissive optical element is an example of a polygonal prism with an even number of side faces. From the viewpoint of less generation of stray light and high light utilization efficiency, a polygonal prism with an even number of side faces is desirable. However, as long as it has a pair of parallel entrance and exit surfaces, the shape may be other than a polygonal prism with an even number of side faces. In addition, the "rotation" in the present embodiment can also include swinging the transmissive optical element to perform a similar scan.

[0130] In addition, the specific description of the shape, number, arrangement, material, etc. of each component of the light source device and the projector is not limited to the above embodiment and can be changed as appropriate. Also, in the above embodiment, an example in which the light source device according to the present invention is mounted on a projector using a liquid crystal panel is shown, but this is not limiting. The light source device according to the present invention may be applied to a projector using a digital micromirror device as a light modulation device.

[0131] [Summary of this disclosure] The following is a summary of this disclosure.

[0132] (Appendix 1) a first light source unit that emits a first light in a first wavelength band; a second light source unit that emits a second light of a second wavelength band different from the first wavelength band; a third light source unit that emits a third light of a third wavelength band different from the first wavelength band and the second wavelength band; a transmissive optical element that is made of a rotatably supported light-transmitting member and transmits each of the first light, the second light, and the third light; Equipped with the transmissive optical element is rotatable about a rotation axis extending along a first direction intersecting each of the incident direction of the first light, the incident direction of the second light, and the incident direction of the third light; a cross-sectional shape perpendicular to a principal ray of the first light emitted from the first light source unit has a major axis extending along the first direction, a cross-sectional shape perpendicular to a principal ray of the second light emitted from the second light source unit has a major axis extending along the first direction, a cross-sectional shape perpendicular to a principal ray of the third light emitted from the third light source unit has a major axis extending along the first direction, the first light is incident on the transmissive optical element at a first position; the second light is incident on the transmissive optical element at a second position different from the first position, the third light is incident on the transmissive optical element at a third position different from the first position and the second position, In the transmissive optical element, an incident surface onto which the first light, the second light, and the third light are incident, and an exit surface from which the first light, the second light, and the third light incident from the incident surface are exited are parallel to each other.

[0133] According to the configuration of Supplementary Note 1, the light emitted from each light source is displaced in a direction perpendicular to the traveling direction of the light while remaining parallel to the optical axis as the transmissive optical element rotates. This allows the light to always be incident on the illuminated surface at a constant angle.

[0134] (Appendix 2) The light source device described in Appendix 1, wherein the transmissive optical element scans two-dimensionally by scanning each of the first light, the second light, and the third light in a direction perpendicular to the first direction when rotated around the rotation axis.

[0135] According to the configuration of Supplementary Note 2, it is possible to illuminate a two-dimensional illumination area by using only one transmissive optical element.

[0136] (Appendix 3) the transmissive optical element has a first surface and a second surface intersecting the rotation axis, and 2×m (m: a natural number equal to or greater than 2) side surfaces in contact with the first surface and the second surface, 3. The light source device according to claim 1, wherein the entrance surface and the exit surface are two of the 2×m side surfaces that are parallel to each other.

[0137] According to the configuration of Supplementary Note 3, since no light is incident on side surfaces that are not parallel to each other, the generation of stray light in the transmissive optical element is reduced, and the light utilization efficiency can be improved.

[0138] (Appendix 4) the first light source unit includes a first light emitting element that emits light in the first wavelength band, the second light source unit includes a second light emitting element that emits light in the second wavelength band, the third light source unit includes a third light emitting element that emits light in the third wavelength band, 4. The light source device according to claim 1, wherein each of the first light-emitting element, the second light-emitting element, and the third light-emitting element is a laser diode that emits laser light.

[0139] According to the configuration of Supplementary Note 4, since linearly polarized laser light is emitted from each light source unit, when a liquid crystal panel is used as a light modulation device of a projector, an incident-side polarizing plate can be omitted.

[0140] (Appendix 5) The first light source unit includes a plurality of the first light emitting elements, The second light source unit includes a plurality of the second light emitting elements, the third light source unit includes a plurality of the third light emitting elements, The plurality of first light emitting elements are arranged along the first direction, The plurality of second light emitting elements are arranged along the first direction, 5. The light source device according to claim 4, wherein the third light emitting elements are arranged along the first direction.

[0141] According to the configuration of Supplementary Note 5, it is possible to generate light having a cross-sectional shape with a major axis extending along the first direction without using an optical system such as a light beam width adjustment optical system.

[0142] (Appendix 6) the first light source unit further includes a first light flux width adjusting optical system that adjusts a light flux width in the first direction of the first light emitted from the first light emitting element, the second light source unit further includes a second light flux width adjusting optical system that adjusts a light flux width in the first direction of the second light emitted from the second light emitting element, The light source device according to claim 4 or 5, wherein the third light source unit further includes a third beam width adjusting optical system that adjusts a beam width in the first direction of the third light emitted from the third light emitting element.

[0143] According to the configuration of Supplementary Note 6, regardless of the number of light emitting elements in each light source section, the luminous flux width in the first direction of each color light can be adjusted in accordance with the size of the illuminated area.

[0144] (Appendix 7) 7. The light source device according to claim 6, wherein each of the first light beam width adjustment optical system, the second light beam width adjustment optical system, and the third light beam width adjustment optical system is an afocal optical system including a cylindrical lens.

[0145] According to the configuration of Supplementary Note 7, the light flux width in the first direction can be adjusted while maintaining the parallelism of each color light.

[0146] (Appendix 8) 8. The light source device according to claim 1, wherein the transmissive optical element is made of quartz.

[0147] According to the configuration of Supplementary Note 8, since the Young's modulus and the thermal expansion coefficient of quartz are small, the thermal distortion of the transmissive optical element is small, and disturbance of the polarization direction of light can be suppressed.

[0148] (Appendix 9) A light source device according to any one of claims 1 to 8, a light modulation device that modulates light including the first light, the second light, and the third light emitted from the transmissive optical element of the light source device based on image information; a projection optical device that projects the light modulated by the light modulation device; A projector equipped with

[0149] According to the configuration of Supplementary Note 9, a color display is possible with a simple configuration, and a projector with excellent image quality can be realized.

[0150] (Appendix 10) a first reflecting element that reflects the third light emitted from the transmissive optical element; a second reflecting element that reflects the first light emitted from the transmissive optical element; a focusing element that focuses the first light reflected by the second reflecting element, the second light emitted from the transmitting optical element, and the third light reflected by the first reflecting element, and guides the focused light to the light modulation device; Further equipped with the first light reflected by the second reflecting element, the second light emitted from the transmissive optical element, and the third light reflected by the first reflecting element are incident on the light collecting element from directions different from each other, The optical modulation device includes: a first sub-pixel that modulates the first light; a second sub-pixel that modulates the second light; a third sub-pixel that modulates the third light, The light-collecting element is The first light emitted from the second reflecting element is incident on the first sub-pixel; The second light emitted from the transmissive optical element is incident on the second sub-pixel; 10. The projector according to claim 9, wherein the third light emitted from the first reflecting element is incident on the third sub-pixel.

[0151] According to the configuration of Supplementary Note 10, a color display is possible without the light modulation device being equipped with a color filter, and a projector excellent in image brightness and color reproducibility can be realized.

[0152] (Appendix 11) the first reflecting element is provided on an optical path of the first light emitted from the first light source unit, and transmits the first light; The projector described in Appendix 10, wherein the second reflecting element is provided on an optical path of the third light emitted from the third light source section and transmits the third light.

[0153] According to the configuration of Supplementary Note 11, the angles of incidence of the first and third lights with respect to the light collecting element can be adjusted by changing the inclination angles of the respective reflecting elements with respect to the optical axis.

[0154] (Appendix 12) The projector described in Appendix 11, wherein an optical axis of the second light source unit is perpendicular to an optical axis of the first light source unit and an optical axis of the third light source unit.

[0155] According to the configuration of Supplementary Note 12, the degree of freedom in the layout of the components that configure the projector can be increased, and the projector can be made smaller.

[0156] (Appendix 13) a light combining element that combines the first light emitted from the transmitting optical element, the second light emitted from the transmitting optical element, and the third light emitted from the transmitting optical element, the first light forms a first illuminated area having a major axis in the first direction on the light modulation device; the second light forms a second illuminated area having a major axis in the first direction on the light modulation device; the third light forms a third illuminated area having a major axis in the first direction on the light modulation device; each of the first illuminated region, the second illuminated region, and the third illuminated region is scanned in a second direction perpendicular to the first direction on the light modulation device in accordance with a rotation of the transmissive optical element; The projector described in Appendix 9, wherein the light modulation device modulates the first light in the first illuminated area, modulates the second light in the second illuminated area, and modulates the third light in the third illuminated area.

[0157] According to the configuration of Supplementary Note 13, a projector capable of color display can be realized without providing a light-collecting element such as a microlens array in front of the light modulation device.

[0158] (Appendix 14) A light source unit that emits light; a transmissive optical element that is made of a rotatably supported light-transmitting member and transmits the light emitted from the light source unit; Equipped with the light source unit includes a first light-emitting unit that emits a first color light, a second light-emitting unit that emits a second color light different from the first color light, and a third light-emitting unit that emits a third color light different from the first color light and the second color light, the transmissive optical element is rotatable about a rotation axis extending along a first direction intersecting an incident direction of the white light, a cross-sectional shape perpendicular to a principal ray of the light emitted from the light source unit has a major axis extending along the first direction, the light emitted from the light source unit is incident on the transmissive optical element without being separated by wavelength band; A light source device, wherein in the transmissive optical element, an incident surface on which the light emitted from the light source unit is incident and an exit surface from which the light incident from the incident surface is exited are parallel to each other.

[0159] According to the configuration of Supplementary Note 14, the light emitted from the light source unit is displaced in a direction perpendicular to the traveling direction of the light while maintaining a state parallel to the optical axis as the transmissive optical element rotates. This allows the light to be always incident on the illuminated surface at a constant angle.

[0160] (Appendix 15) A first light source that emits a first color light; a second light source that emits a second color light different from the first color light; a third light source that emits a third color light different from the first color light and the second color light; a transmissive optical element that is made of a rotatably supported light-transmitting member and transmits the first color light, the second color light, and the third color light emitted from the first light source, the second light source, and the third light source; Equipped with the transmissive optical element is rotatable about a rotation axis extending along a first direction intersecting an incident direction of the first color light, the second color light, and the third color light; a cross-sectional shape perpendicular to a principal ray of the first colored light, the second colored light, and the third colored light has a major axis extending along the first direction, the first light source, the second light source, and the third light source emit the first color light, the second color light, and the third color light at different times, respectively; In the light source device, in the transmissive optical element, an entrance surface on which the first color light is incident and an exit surface from which the first color light incident from the entrance surface is exited are parallel to each other.

[0161] According to the configuration of Supplementary Note 15, it is possible to improve problems such as a decrease in brightness and contrast in the light modulation device, the occurrence of color unevenness, light loss in the projection optical device, and uneven illuminance caused by using a light source having coherence. Furthermore, by using a configuration in which each color light is emitted in a time-division manner, it is possible to reduce the amount of light incident on the transmissive optical element compared to a case in which three color lights are incident on the transmissive optical element at once, which makes it possible to suppress the temperature rise of the optical element and contributes to suppressing the effects of thermal distortion.

[0162] (Appendix 16) A light source device according to claim 14 or 15. a light modulation device that modulates the light emitted from the transmissive optical element of the light source device based on image information; a projection optical device that projects the light modulated by the light modulation device; A projector equipped with

[0163] According to the configuration of Supplementary Note 16, a projector with excellent image quality can be realized with a simple configuration. [Explanation of symbols]

[0164] Reference Signs List 10,40,60,80,100,120,140...light source device, 11,61,81...first light source section, 12,62,82...second light source section, 13,63,83...third light source section, 14...transmissive optical element, 14c1,14c2,14c3,14c4...side surface, 17...first reflecting element, 18...second reflecting element, 20,30,50,70,90,110,130...projector, 21...light modulation device, 21B...first illuminated area, 21G...second illuminated area, 21R...third illuminated area, 23...projection optical device, 25...first light emitting element, 26...second light emitting element element, 27...third light-emitting element, 43...first microlens array (light-collecting element), 65, 85...first light beam width adjustment optical system, 66, 86...second light beam width adjustment optical system, 67, 87...third light beam width adjustment optical system, 91...light combining element, 122, 142...light source unit, AX1, AX2, AX3...optical axis, C1...rotation axis, LB...blue light (first light), LG...green light (second light), LR...red light (third light), P1...first position, P2...first position, P3...first position, PX1...first sub-pixel, PX2...second sub-pixel, PX3...third sub-pixel, Q...illuminated area.

Claims

1. A first light source unit that emits a first light in a first wavelength band; a second light source unit that emits a second light of a second wavelength band different from the first wavelength band; a third light source unit that emits third light of a third wavelength band different from the first wavelength band and the second wavelength band; a transmissive optical element that is made of a rotatably supported light-transmitting member and transmits each of the first light, the second light, and the third light; Equipped with the transmissive optical element rotates about a rotation axis extending along a first direction intersecting each of the incident direction of the first light, the incident direction of the second light, and the incident direction of the third light; a cross-sectional shape of the first light perpendicular to a principal ray of the first light emitted from the first light source unit has a major axis extending along the first direction, a cross-sectional shape of the second light perpendicular to a principal ray of the second light emitted from the second light source unit has a major axis extending along the first direction, a cross-sectional shape of the third light perpendicular to a principal ray of the third light emitted from the third light source unit has a major axis extending along the first direction, the first light is incident on the transmissive optical element at a first position; the second light is incident on the transmissive optical element at a second position different from the first position, the third light is incident on the transmissive optical element at a third position different from the first position and the second position, In the transmissive optical element, an incident surface onto which the first light, the second light, and the third light are incident and an exit surface from which the first light, the second light, and the third light incident from the incident surface are exited are parallel to each other, The light source device, wherein the first light, the second light, and the third light are incident on the transmissive optical element at angles different from one another in a rotation direction of the transmissive optical element.

2. 2. The light source device of claim 1, wherein the transmissive optical element scans two-dimensionally by scanning each of the first light, the second light, and the third light in a direction perpendicular to the first direction when rotated around the rotation axis.

3. the transmissive optical element has a first surface and a second surface intersecting the rotation axis, and 2×m (m: a natural number equal to or greater than 2) side surfaces in contact with the first surface and the second surface, 3. The light source device according to claim 1, wherein the entrance surface and the exit surface are two of the 2xm side surfaces that are parallel to each other.

4. the first light source unit includes a first light emitting element that emits light in the first wavelength band, the second light source unit includes a second light emitting element that emits light in the second wavelength band, the third light source unit includes a third light emitting element that emits light in the third wavelength band, 3. The light source device according to claim 1, wherein each of the first light emitting element, the second light emitting element, and the third light emitting element is a laser diode that emits laser light.

5. The first light source unit includes a plurality of the first light emitting elements, The second light source unit includes a plurality of the second light emitting elements, The third light source unit includes a plurality of the third light emitting elements, The first light emitting elements are arranged along the first direction, The plurality of second light emitting elements are arranged along the first direction, The light source device according to claim 4 , wherein the third light emitting elements are arranged along the first direction.

6. the first light source unit further includes a first light flux width adjusting optical system that adjusts a light flux width in the first direction of the first light emitted from the first light emitting element, the second light source unit further includes a second light flux width adjusting optical system that adjusts a light flux width in the first direction of the second light emitted from the second light emitting element, The light source device according to claim 4 , wherein the third light source section further comprises a third beam width adjusting optical system that adjusts a beam width in the first direction of the third light emitted from the third light emitting element.

7. The light source device according to claim 6 , wherein each of the first light beam width adjusting optical system, the second light beam width adjusting optical system, and the third light beam width adjusting optical system is an afocal optical system including a cylindrical lens.

8. 3. The light source device according to claim 1, wherein the transmissive optical element is made of quartz.

9. The light source device according to claim 1 or 2, a light modulation device that modulates light including the first light, the second light, and the third light emitted from the transmissive optical element of the light source device based on image information; a projection optical device that projects the light modulated by the light modulation device; A projector equipped with

10. a first reflecting element that reflects the third light emitted from the transmissive optical element; a second reflecting element that reflects the first light emitted from the transmissive optical element; a focusing element that focuses the first light reflected by the second reflecting element, the second light emitted from the transmitting optical element, and the third light reflected by the first reflecting element, and guides the focused light to the light modulation device; Further equipped with the first light reflected by the second reflecting element, the second light emitted from the transmitting optical element, and the third light reflected by the first reflecting element are incident on the light collecting element from directions different from each other, The optical modulation device includes: a first sub-pixel that modulates the first light; a second sub-pixel that modulates the second light; a third sub-pixel that modulates the third light, The light-collecting element is The first light emitted from the second reflecting element is incident on the first sub-pixel; The second light emitted from the transmissive optical element is incident on the second sub-pixel; The projector according to claim 9 , wherein the third light emitted from the first reflecting element is incident on the third sub-pixel.

11. the first reflecting element is provided on an optical path of the first light emitted from the first light source unit, and transmits the first light; The projector according to claim 10 , wherein the second reflecting element is provided on an optical path of the third light emitted from the third light source unit and transmits the third light.

12. The projector according to claim 11 , wherein an optical axis of the second light source unit is perpendicular to an optical axis of the first light source unit and an optical axis of the third light source unit.

13. A first light source unit that emits a first light of a first wavelength band; a second light source unit that emits a second light of a second wavelength band different from the first wavelength band; a third light source unit that emits third light of a third wavelength band different from the first wavelength band and the second wavelength band; a transmissive optical element that is made of a rotatably supported light-transmitting member and transmits each of the first light, the second light, and the third light; the transmissive optical element rotates about a rotation axis extending along a first direction intersecting each of the incident direction of the first light, the incident direction of the second light, and the incident direction of the third light; a cross-sectional shape of the first light perpendicular to a principal ray of the first light emitted from the first light source unit has a major axis extending along the first direction, a cross-sectional shape of the second light perpendicular to a principal ray of the second light emitted from the second light source unit has a major axis extending along the first direction, a cross-sectional shape of the third light perpendicular to a principal ray of the third light emitted from the third light source unit has a major axis extending along the first direction, the first light is incident on the transmissive optical element at a first position; the second light is incident on the transmissive optical element at a second position different from the first position, the third light is incident on the transmissive optical element at a third position different from the first position and the second position, a light source device, in which an incident surface on which the first light, the second light, and the third light are incident and an exit surface from which the first light, the second light, and the third light incident from the incident surface are exited are parallel to each other in the transmissive optical element; a light modulation device that modulates light including the first light, the second light, and the third light emitted from the transmissive optical element of the light source device based on image information; a projection optical device that projects the light modulated by the light modulation device; a light combining element that combines the first light emitted from the transmissive optical element, the second light emitted from the transmissive optical element, and the third light emitted from the transmissive optical element, the first light forms a first illuminated region having a major axis in the first direction on the light modulation device; the second light forms a second illuminated area having a major axis in the first direction on the light modulation device; the third light forms a third illuminated area having a major axis in the first direction on the light modulation device; each of the first illuminated region, the second illuminated region, and the third illuminated region is scanned in a second direction perpendicular to the first direction on the light modulation device in accordance with a rotation of the transmissive optical element; A projector, wherein the light modulation device modulates the first light in the first illuminated area, modulates the second light in the second illuminated area, and modulates the third light in the third illuminated area.

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