Light source device and projection type video display device

Abstract

This light source device comprises: a light source element that outputs light source light which is light in a first wavelength region; a selection reflection element that divides the light source light into first light and second light; a first light direction conversion element that reflects the first light in a second direction; and a wavelength conversion element that converts the first light into third light. The selection reflection element emits the second light and the third light in a third direction. The light source element outputs the light source light in a direction different from the second direction.

Description

Technical Field

[0001] The present invention relates to a light source device and a projection type video display device including the same.

Background Art

[0002] Conventionally, there has been a projection type video display device that irradiates a phosphor wheel with light from a light source and generates white light using the light from the light source and the generated light.

[0003] For example, in a projection type video display device, blue light irradiated from a light source is irradiated onto a phosphor wheel to generate fluorescence, and the generated fluorescence and the blue light irradiated from the light source are combined to generate white light. This white light is further separated into three primary color lights, modulated for each color light, and the modulated color lights are combined again to generate video light.

[0004] For example, in Patent Document 1, a light source or a phosphor wheel is disposed in either region in a plan view with the optical axis from which light is emitted from the light source device as a boundary, and the phosphor wheel is irradiated with the light from the light source. Also described is a light source device that emits blue light and fluorescence in a time-division manner.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] However, in the technique described in Patent Document 1, since the light source and the phosphor wheel are arranged so as to surround the optical axis of the light emitted from the light source device, the size of the light source device becomes large.

[0007] An object of the present disclosure is to provide a light source device and a projection type video display device that can be miniaturized.

[0008] The light source device according to the present disclosure includes a light source element that outputs light source light which is light in a first wavelength range, a selective reflection element that reflects a part of the light source light and transmits the remaining part of the light source light, thereby separating the light source light into first light and second light, a first light direction conversion element that is disposed at a position to receive the first light emitted from the selective reflection element in a first direction and reflects the first light in a second direction, and a wavelength conversion element that is disposed at a position to receive the first light reflected in the second direction by the first light direction conversion element and converts the first light into third light which is light in a second wavelength range. The first light direction conversion element reflects the third light emitted from the wavelength conversion element in a third direction opposite to the first direction. The selective reflection element transmits the third light reflected by the first light direction conversion element. From the selective reflection element, the second light and the third light are emitted in the third direction. The light source element outputs the light source light in a direction different from the second direction.

[0009] Further, a projection type video display device according to the present disclosure includes the above-described light source device, and a light modulation unit that generates video light using the second light and the third light emitted from the light source device. And a projection optical system that projects the video light.

[0010] The present disclosure can provide a light source device and a projection type video display device that can be miniaturized.

Brief Description of Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5A

Figure 5B

Figure 5C

Figure 5D

Figure 5E

Figure 5F

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Embodiments for Carrying Out the Invention

[0012] Hereinafter, embodiments will be described in detail with appropriate reference to the drawings. However, a more detailed description than necessary may be omitted. For example, detailed descriptions of already well-known matters and duplicate descriptions of substantially the same configurations may be omitted. This is to avoid making the following description unnecessarily redundant and to facilitate the understanding of those skilled in the art.

[0013] Note that the attached drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0014] (Embodiment 1) [1-1. Configuration of Light Source Device] Hereinafter, the light source device according to Embodiment 1 will be described with reference to FIGS. 1 and 2. In Embodiment 1, for example, a light source device used in a projection type video display device will be described. FIG. 1 is a schematic configuration diagram showing a configuration example of the light source device. FIG. 2 is a front view of the wavelength conversion element. In each figure, the direction in which light is emitted from the light source unit 3 is defined as the Z direction, the plane on which the wavelength conversion element 25 receives light is defined as the XZ plane formed by the Z direction and the X direction orthogonal to the Z direction, and the direction orthogonal to the XZ plane is defined as the Y direction.

[0015] The light source device 1 includes a light source unit 3, a first light direction conversion element 13, a polarization conversion element 15, a selective reflection element 17, and a wavelength conversion element 25. The light source device 1 further includes a convex lens 5, a diffusion plate 7, and a concave lens 11 on the optical path between the light source unit 3 and the first light direction conversion element 13, a condenser lens 21 and 23 on the optical path between the first light direction conversion element 13 and the wavelength conversion element 25, and a condenser element 19 and a rod integrator 33 after the selective reflection element 17.

[0016] The light source unit 3 includes a light source element 3a that emits light source light Lc0 and a collimator lens 3b that collimates the light source light Lc0 emitted from the light source element 3a. The collimator lens 3b is disposed corresponding to the light source element 3a, and the light source unit 3 includes a plurality of sets of light source elements 3a and collimator lenses 3b. The light source element 3a outputs light in a blue wavelength range as light in a first wavelength range. In Embodiment 1, as an example, a configuration in which the light source element 3a is a laser light source element and outputs P-polarized blue light will be described.

[0017] The collimated light source light Lc0 is incident on the subsequent convex lens 5, reducing its light beam width, and then is incident on the subsequent diffusion plate 7, where it is diffused and the uniformity of the light is improved. The light source light Lc0 with improved light uniformity is incident on the subsequent concave lens 11 and is collimated again into a parallel light beam.

[0018] The light source light Lc0 collimated by the concave lens 11 is incident on the first light direction conversion element 13 arranged at an angle of approximately 45 degrees with respect to the optical axis. The first light direction conversion element 13 is, for example, a dichroic polarization separation mirror. In the first light direction conversion element 13, the light source light Lc0 in the first wavelength range emitted from the light source element 3a is transmitted, and the third light Lc3, which is, for example, yellow light wavelength-converted by the wavelength conversion element 25 using the light source light Lc0 from the light source element 3a as the excitation light, is reflected. Therefore, the light source light Lc0 incident on the first light direction conversion element 13 passes through the first light direction conversion element 13 and travels straight without changing its traveling direction and is incident on the polarization conversion element 15. In this way, the first light direction conversion element 13 has the spectral characteristic of transmitting the light source light Lc0, which is P-polarized blue light (light in the first wavelength range), and reflecting the first light Lc1, which is S-polarized blue light, and the third light Lc3, which is yellow light to be described later. The yellow light, which is light in the second wavelength range, is the light wavelength-converted by the wavelength conversion element 25 from the light source light Lc0.

[0019] The polarization conversion element 15 is, for example, a retardation plate such as a quarter-wave plate. The light source light Lc0 incident on the polarization conversion element 15 is converted from P-polarized blue light to circularly polarized blue light. The light source light Lc0 with its polarization direction converted travels straight and is incident on the selective reflection element 17.

[0020] The selective reflection element 17 separates the light source light Lc0 into the first light Lc1, which will be converted into fluorescence later, and the second light Lc2, which is emitted as blue light, by reflecting a part of the light source light Lc0 and transmitting the rest of the light source light Lc0, and also transmits the third light Lc3. The selective reflection element 17 is, for example, a single dichroic mirror.

[0021] The selective reflection element 17 has, for example, a reflectance of the light source light Lc0 (the reflectance of the selective reflection element 17 with respect to the light source light Lc0) of 70% or more, and a transmittance of the third light Lc3 (the transmittance of the selective reflection element 17 with respect to the third light Lc3) of 95% or more. A dielectric film is uniformly formed on the surface of the selective reflection element 17, and the transmittance of the light source light Lc0 is uniform. The direction opposite to the direction in which light is emitted from the light source device 1 (the negative direction of the Z direction) is defined as the first direction, the direction in which light travels from the first light direction conversion element 13 toward the wavelength conversion element (the negative direction of the Y direction) is defined as the second direction, and the direction in which light is emitted from the light source device 1 (the positive direction of the Z direction) is defined as the third direction. In Embodiment 1, the first direction is the direction in which light is reflected by the selective reflection element 17 and travels toward the first light direction conversion element, and the third direction is also the direction in which light passes through the selective reflection element 17. The light source light Lc0 that has passed through the selective reflection element 17 travels straight in the third direction and enters the condenser element 19.

[0022] The first light Lc1 reflected by the selective reflection element 17 passes through the polarization conversion element 15 and is converted from circularly polarized light to S-polarized blue light. The first light Lc1, which is S-polarized blue light, has its traveling direction changed by 90 degrees by the first light direction conversion element 13 and is reflected in the second direction. A condenser lens 21, 23, and a wavelength conversion element 25 are arranged on the optical path in the second direction from the first light direction conversion element 13. The condenser lenses 21 and 23 are arranged between the first light direction conversion element 13 and the wavelength conversion element 25.

[0023] The first light Lc1 reflected in the second direction by the first light direction conversion element 13 passes through the condenser lens 21 and the subsequent condenser lens 23 and is condensed onto a ring-shaped wavelength conversion layer 29 provided in the subsequent wavelength conversion element 25. The wavelength conversion element 25 is, for example, a phosphor wheel.

[0024] The wavelength conversion element 25 includes a substrate 27, a wavelength conversion layer 29 laminated on the substrate 27, and a motor 31 attached to the substrate 27. The wavelength conversion element 25 is arranged such that the first light Lc1 condensed by the condenser lenses 21 and 23 is incident on the annular wavelength conversion layer 29. The wavelength conversion element 25 is rotationally driven by the motor 31. The incident surface of the wavelength conversion layer 29 is arranged parallel to the third direction, that is, parallel to the XZ plane.

[0025] The wavelength conversion layer 29 generates a third light Lc3 having a different wavelength from the incident first light Lc1. The wavelength conversion layer 29 is, for example, a phosphor layer formed using a resin or an inorganic substance such as silicone or alumina as a binder and containing a plurality of phosphor particles therein.

[0026] The phosphor particles of the wavelength conversion layer 29 emit a third light Lc3 in a wavelength range longer than the wavelength range of the incident first light Lc1. The phosphor particles of the wavelength conversion layer 29 are, for example, Ce-activated YAG-based yellow phosphors that are excited by the incident blue-colored light and emit yellow light containing wavelength components of green light and red light. A typical chemical structure of the crystal matrix of these phosphor particles is Y3Al5O 12 is.

[0027] A reflective layer that reflects the third light Lc3 generated in the wavelength conversion layer 29 may be disposed between the substrate 27 and the wavelength conversion layer 29. Thereby, the third light Lc3 that travels toward the substrate 27 in the wavelength conversion layer 29 can be made to travel toward the first light direction conversion element 13, so that the conversion efficiency of fluorescence can be improved.

[0028] In this way, the first light Lc1, which is blue light condensed on the wavelength conversion layer 29 of the wavelength conversion element 25 by the condenser lenses 21 and 23, is wavelength-converted into fluorescence, and the traveling direction of the light is changed by 180 degrees, and the light is incident on the condenser lenses 23 and 21 in this order and collimated. The third light Lc3, which is fluorescence, is natural light in the yellow wavelength range so as to constitute, for example, white light in combination with the blue light emitted from the light source element 3a.

[0029] The third light Lc3 that exits the light collecting lens 21 and is made parallel enters the first light direction conversion element 13. As described above, the first light direction conversion element 13 has the property of reflecting light in the wavelength region of the third light Lc3, so it changes the traveling direction of the light by 90 degrees. The third light Lc3 whose traveling direction has been changed by 90 degrees by the first light direction conversion element 13 passes through the subsequent polarization conversion element 15 and the selective reflection element 17 and enters the light collecting element 19.

[0030] The light collecting element 19 is, for example, a light collecting lens and is arranged at a position to receive the light emitted from the selective reflection element 17 in the third direction. A rod integrator 33 is arranged downstream of the light collecting element 19, and the light collecting element 19 collects the incident light onto the rod integrator 33.

[0031] The second light Lc2 that has passed through the selective reflection element 17 and the third light Lc3 from the wavelength conversion element 25 enter the light collecting element 19 and are collected, and enter a rod integrator 33 having an incident end arranged at a substantially light collecting position of the light collecting element 19. The light with the beam flux homogenized by the rod integrator 33 exits from the exit end of the rod integrator 33.

[0032] [1- 2 . Effects, etc.] As described above, in Embodiment 1, the light source device 1 includes a light source element 3a that outputs light source light Lc0 which is light in a first wavelength range, and a selective reflection element 17 that reflects a part of the light source light Lc0 and transmits the remainder of the light source light Lc0, thereby separating the light source light Lc0 into a first light Lc1 and a second light Lc2, and transmitting a third light Lc3 which is light in a second wavelength range. The light source device 1 further includes a first light direction conversion element 13 that is disposed at a position to receive the first light Lc1 emitted from the selective reflection element 17 in a first direction, and that reflects the first light Lc1 and the third light Lc3, and a wavelength conversion element 25 that is disposed at a position to receive the light reflected in a second direction by the first light direction conversion element 13, and that converts the incident first light Lc1 into the third light Lc3. The first light Lc1 emitted from the selective reflection element 17 is reflected in a second direction by the first light direction conversion element 13 and then enters the wavelength conversion element 25. The third light Lc3 emitted from the wavelength conversion element 25 is reflected in a third direction opposite to the first direction by the first light direction conversion element 13 and then enters the selective reflection element 17. From the selective reflection element 17, the second light Lc2 and the third light Lc3 are emitted in the third direction. The light source element 3a outputs the light source light Lc0 in a direction different from the second direction.

[0033] The selective reflection element 17 separates the light source light Lc0 into the first light Lc1 and the second light Lc2, transmits the third light Lc3 which is light in the second wavelength range, and emits the second light and the third light in the third direction. Therefore, the second light and the third light can be emitted from the light source device 1 simultaneously. Also, since it is not necessary to dispose the light source element 3a and the wavelength conversion element 25 to face each other, the light source device 1 can be miniaturized.

[0034] In particular, since the light source unit 3 and the wavelength conversion element 25 are disposed such that the direction in which the light source light Lc0 is emitted from the light source element 3a coincides with the direction in which light is emitted from the rod integrator 33, further miniaturization of the light source device 1 can be achieved.

[0035] In Embodiment 1 shown in FIG. 1, the first light direction conversion element 13 was arranged at an angle of approximately 45 degrees with respect to the optical axis. However, in order to maximize its spectroscopic characteristics, the angle of the first light direction conversion element 13 with respect to the optical axis may be different from approximately 45 degrees. In that case, other components may be arranged according to that angle. Here, an example in which the light source light Lc0 emitted from the light source element 3a is P-polarized is shown. However, the same configuration is possible even when the light source light Lc0 emitted from the light source element 3a is S-polarized.

[0036] Next, a light source device 1A, which is a modification of the light source device 1 of Embodiment 1, will be described with reference to FIG. 3. The light source device 1A is configured such that the selective reflection element 17 of the light source device 1 is displaceable. The light source device 1 of Embodiment 1 and the light source device 1A of the modification are common in configuration except for this point and the points described below.

[0037] The selective reflection element 17A of the light source device 1A has characteristics in which the reflectance of the light source light Lc0 within its plane is different. As shown in FIG. 4, the lower region of the selective reflection element 17A has a large reflectance of the light source light Lc0, and the reflectance of the light source light Lc0 decreases as it transitions to the upper region of the selective reflection element 17A. The selective reflection element 17A is configured such that the reflectance of the light source light Lc0 (the reflectance of the selective reflection element 17A with respect to the light source light Lc0) continuously changes along a predetermined direction, for example, the slide direction (the direction of the arrow in FIG. 4). Such a selective reflection element 17A can obtain such characteristics, for example, by gradually increasing the thickness of the reflection film from the lower region to the upper region.

[0038] The light source device 1A includes a slide mechanism 18 for sliding the selective reflection element 17A. The slide mechanism 18 is composed of, for example, a motor, a rack, and a pinion. When the selective reflection element 17A moves in a predetermined direction by the slide mechanism 18, the ratio of the first light Lc1 and the second light Lc2 to be emitted is changed. The operation of the slide mechanism 18 can be performed by the user.

[0039] Therefore, according to the light source device 1A, by sliding and adjusting the selective reflection element 17A, the light amounts of the second light Lc2 and the third light Lc3 emitted from the selective reflection element 17A can be adjusted. For example, when the light flux of the light source light Lc0 is irradiated onto a region of the selective reflection element 17A where the reflectance of the light source light Lc0 is small, the light amount of the second light Lc2, which is blue light, emitted from the selective reflection element 17A can be increased, and the light amount of the third light Lc3, which is yellow light, can be decreased. Further, when the light flux of the light source light Lc0 is irradiated onto a region of the selective reflection element 17A where the reflectance of the light source light Lc0 is large, the light amount of the second light Lc2, which is blue light, emitted from the selective reflection element 17A can be decreased, and the light amount of the third light Lc3, which is yellow light, can be increased.

[0040] In this way, the user can adjust the hue of the light emitted from the light source device 1A by sliding the selective reflection element 17A with the slide mechanism 18. This can be used, for example, when adjusting the initial settings of a projection type video display device.

[0041] (Embodiment 2) Next, with reference to FIGS. 5A to 5F, the light source device 1B of Embodiment 2 will be described. FIG. 5A is a schematic configuration diagram showing a configuration example of the light source device according to Embodiment 2. FIG. 5B is an explanatory diagram for explaining the optical paths of the light obliquely incident on and re-incident on the first light direction conversion element according to Embodiment 2. FIG. 5C is an explanatory diagram for explaining the optical path from when the light is incident on the first light direction conversion element to when it is re-incident according to Embodiment 2. FIG. 5D is an explanatory diagram for explaining P-polarized light with respect to the first light direction conversion element. FIG. 5E is an explanatory diagram for explaining S-polarized light with respect to the first light direction conversion element. FIG. 5F is an explanatory diagram showing an example of the state of linearly polarized light.

[0042] The light source device 1 of Embodiment 1 includes the polarization conversion element 15 composed of one retardation plate, while the light source device 1B of Embodiment 2 includes the polarization conversion element 15B including two quarter-wave plates. The light source device 1B of Embodiment 2 and the light source device 1 of Embodiment 1 are common in configuration except for this point and the points described below.

[0043] When the polarization conversion element is composed of one quarter-wave plate, the separation directions of P-polarized light and S-polarized light are different between the first incidence and the second incidence of blue light on the first light direction conversion element 13, so the separation performance of P-polarized light and S-polarized light may decrease. In the case of the light source device 1 of Embodiment 1, when the light source light Lc0 obliquely enters the first light direction conversion element 13 for the first time, and when the light source light Lc0 is reflected by the selective reflection element 17 and then obliquely enters the first light direction conversion element 13 as the first light Lc1 for the second time, the incident angles on the first light direction conversion element 13 are different. The first light Lc1 transmitted through the first light direction conversion element 13 for the first time mainly has a P-polarization component, but when it obliquely enters the first light direction conversion element 13, an S-polarization component may be included, and the separation of P-polarized light and S-polarized light may not be properly achieved.

[0044] Here, P-polarized light and S-polarized light with respect to the first light direction conversion element 13 will be described. As shown in FIG. 5D, the P-polarized light Lp is a component of light whose vibration plane is parallel to the plane P1 determined by the incident light Lc0a on the first light direction conversion element 13 and the reflected light Lc0b from the first light direction conversion element 13 among the light source light Lc0 incident on the first light direction conversion element 13. Note that since the first light direction conversion element 13 is arranged such that its polarization axis is parallel to the vibration plane of the P-polarized light Lp component of the light source light Lc0 traveling along the optical axis, most of the P-polarized light Lp component of the light source light Lc0 incident on the first light direction conversion element 13 passes through the first light direction conversion element 13. The light source light Lc0 transmitted through the first light direction conversion element 13, that is, the vibration plane of the P-polarized light Lp, is parallel to the plane P1.

[0045] As shown in FIG. 5E, the S-polarized light is a component of light whose electric field vibration plane is perpendicular to the plane P1 determined by the incident light Lc0c on the first light direction conversion element 13 and the reflected light Lc0d from the first light direction conversion element 13 among the light source light Lc0. Note that most of the S-polarization component Ls of the light source light Lc0 is reflected by the first light direction conversion element 13.

[0046] The light source element 3a is arranged such that the plane of vibration of the light passing through the optical axis of the light source light Lc0 emitted from the light source unit 3 passes through the polarization axis (transmission axis) of the first light direction conversion element 13. However, the light source light Lc0 emitted from the light source unit 3 has a certain width in the angle of the plane of vibration. Therefore, the P-polarized Lp component passing through the first light direction conversion element 13 includes cases where the plane of vibration is not necessarily the same as the polarization axis of the first light direction conversion element 13 depending on the incident direction of the light source light Lc0. Thus, the plane of vibration of the P-polarized component Lp0 of the light source light Lc0 passing through the first light direction conversion element 13 varies depending on the direction of the incident light.

[0047] Also, although the light source light Lc0 is collimated, it has a certain width in the angle of the traveling direction with respect to the optical axis. Therefore, the light source light Lc0 includes light rays that are not parallel to the optical axis but are inclined and incident on the first light direction conversion element 13. As shown in FIG. 5B, for example, when the light source light Lc0, which is linearly polarized blue light in the Y-axis direction, is incident on the first light direction conversion element 13 from the light source unit 3 for the first time, the light beam of the light source light Lc0 that is inclined with respect to the optical axis and incident on the first light direction conversion element 13 includes a component of S-polarized light Ls perpendicular to the incident and reflection surface determined by the incident light and the reflected light. Therefore, a part of the light amount is reflected by the first light direction conversion element 13.

[0048] Also, although the first polarization conversion element 15B and the selective reflection element 17 are omitted in FIG. 5B, when the light passes through the first light direction conversion element 13, is reflected by the selective reflection element 17, and is incident on the first light direction conversion element 13 for the second time, the direction of the reflected light is different from that at the first incidence. Therefore, since the incident and reflection surface determined by the incident light and the reflected light is different, the light passing through the first light direction conversion element 13 cannot be completely converted into S-polarized light at the second incidence with only one quarter-wave plate, and the P-polarized component passes through the first light direction conversion element 13. Thus, the light that is incident on the first polarization conversion element 15 deviating from the optical axis causes a reduction in the light utilization efficiency due to the amount of light passing through the first light direction conversion element 13 at the second incidence.

[0049] As shown in FIGS. 5B and 5C, for the light rays in the light source light Lc0 that are not parallel to the Z axis, the directions of the incident and exit surfaces do not match between the first incidence and the second incidence of the blue light on the first light direction conversion element 13 (see FIG. 5B). Therefore, the directions of the P polarization and the S polarization are different depending on the angle of the incident light. The polarization direction of the P polarization (S polarization) with respect to the first incidence on the first light direction conversion element 13 and the polarization direction of the P polarization (S polarization) with respect to the second incidence are substantially symmetric with respect to the Y axis.

[0050] In the light source device 1 of the first embodiment, the polarization conversion element is constituted by a single quarter-wave plate, and is arranged such that its slow axis forms an angle of 45 degrees with respect to the Y axis. Therefore, in the configuration of the first embodiment, for the light rays that are not parallel to the Z axis, the second incident light on the first light direction conversion element 13, that is, the light whose polarization direction has rotated 90 degrees from the P polarization with respect to the first incidence and has been converted to S polarization, will also include a P polarization component with respect to the second incidence. Therefore, the second incident light on the first light direction conversion element 13 may include a component that passes through the first light direction conversion element 13 and returns to the light source unit 3.

[0051] Therefore, the polarization conversion element 15B of the second embodiment includes a first quarter-wave plate 15Ba and a second quarter-wave plate 15Bb whose slow axes do not coincide. That is, the slow axis (first slow axis) of the first quarter-wave plate 15Ba does not coincide with the slow axis (second slow axis) of the second quarter-wave plate 15Bb. Thereby, the polarization direction at the second incidence on the first light direction conversion element 13 is made to coincide with the S polarization direction with respect to the second incidence. The polarization conversion element 15B mutually converts linearly polarized light and elliptically polarized light.

[0052] The light Lcb included in the light source light Lc0 is incident obliquely to the optical axis on the first light direction conversion element 13. The linearly polarized light Lcb1, which is the light Lcb transmitted through the first light direction conversion element 13, is inclined with respect to the Y-axis as shown in FIG. 5F. When the light Lcb1 is incident on the first light direction conversion element 13 again, it must be reflected toward the wavelength conversion element 25. At this time, the S-polarized light reflected by the first light direction conversion element 13 must be light having the vibration plane of the light Lcb2. The vibration plane of the light Lcb2 is the vibration plane obtained by further rotating the vibration plane of the light Lcb1a, which is the vibration plane of the light Lcb1 converted symmetrically with respect to the Y-axis, by 90 degrees.

[0053] Note that the linearly polarized light Lca1, which is the light Lca traveling along the optical axis included in the light source light Lc0 and transmitted through the first light direction conversion element 13, has a vibration plane along the Y-axis. Therefore, when the light Lca1 is incident on the first light direction conversion element 13 again, the S-polarized light reflected toward the wavelength conversion element 25 is the light Lca2 having a vibration plane on the X-axis.

[0054] The first quarter-wave plate 15Ba and the second quarter-wave plate 15Bb are disposed between the first light direction conversion element 13 and the selective reflection element 17. The first quarter-wave plate 15Ba is disposed such that the slow axis forms an angle of 45 degrees with respect to the Y-axis. When used alone, similar to the first embodiment, linearly polarized light traveling along the optical axis and incident (P-polarized light with respect to the first incidence on the first light direction conversion element 13) is converted into circularly polarized light, and the circularly polarized light reflected by the selective reflection element 17 and incident again is converted into linearly polarized light rotated by 90 degrees (S-polarized light with respect to the first incidence on the first light direction conversion element 13).

[0055] The second quarter-wave plate 15Bb is arranged such that its slow axis is parallel or orthogonal to the Y-axis. When used alone, it converts linearly polarized light (P-polarized light with respect to the first incidence on the first optical direction conversion element 13) whose polarization direction is inclined with respect to the Y-axis (slow axis) into elliptically polarized light whose major axis coincides with the slow axis, regardless of the inclination. The elliptically polarized light that is reflected by the selective reflection element 17 and then incident on the second quarter-wave plate 15Bb again is converted into linearly polarized light whose polarization direction is inclined at an angle (symmetrical) opposite to the first one with respect to the Y-axis (slow axis), which substantially coincides with the polarization direction of P-polarized light with respect to the second incidence on the first optical direction conversion element 13. This becomes S-polarized light with respect to the second incidence when rotated by 90 degrees.

[0056] Thus, by combining and using the first quarter-wave plate 15Ba and the second quarter-wave plate 15Bb, the effects of both are combined, and the polarization direction at the second incidence on the first optical direction conversion element 13 substantially coincides with the S-polarization direction with respect to the second incidence. Therefore, the P-polarization component that passes through the first optical direction conversion element 13 and returns to the light source unit 3 can be reduced. It is possible to prevent the reduction of the blue light reflected by the first optical direction conversion element 13, and it is possible to suppress the reduction of the amount of fluorescence converted by the wavelength conversion element 25.

[0057] The light source light Lc0 emitted from the light source element 3a is converted from linearly polarized blue light (P-polarized light with respect to the first incident surface to the first light direction conversion element 13) to elliptically polarized blue light by passing through the first quarter-wave plate 15Ba and the second quarter-wave plate 15Bb. A part of the light source light Lc0 converted to elliptically polarized blue light is reflected as the first light Lc1 by the selective reflection element 17, and the rest is transmitted as the second light Lc2. The reflected first light Lc1 is converted from elliptically polarized blue light to S-polarized blue light by passing through the first quarter-wave plate 15Ba and the second quarter-wave plate 15Bb again. The first light Lc1 converted to S-polarized blue light (S-polarized light with respect to the second incident surface to the first light direction conversion element 13) is reflected by the first light direction conversion element 13 and travels toward the wavelength conversion element 25. Here, an example of conversion from P-polarized light to S-polarized light is shown, but the same configuration is possible even when converting from S-polarized light to P-polarized light. Among the light source light Lc0, the linearly polarized light (P-polarized light with respect to the first incidence to the first light direction conversion element 13) traveling along the optical axis is not affected by the action of the second quarter-wave plate 15Bb, and thus is converted to circularly polarized light by the first quarter-wave plate 15Ba. The circularly polarized light reflected by the selective reflection element 17 and incident again is converted by the first quarter-wave plate 15Ba into linearly polarized light rotated by 90 degrees (S-polarized light with respect to the first incidence to the first light direction conversion element 13). Since this linearly polarized light rotated by 90 degrees also travels along the optical axis, it is not affected by the action of the second quarter-wave plate 15Bb and can be reflected by the first light direction conversion element 13 toward the wavelength conversion element 25.

[0058] As described above, by using a pair of the first quarter-wave plate 15Ba and the second quarter-wave plate 15Bb to mutually convert linearly polarized light and elliptically polarized light, the separation performance between P-polarized light and S-polarized light can be further improved. Thereby, it is possible to prevent a reduction in the S-polarized blue light reflected by the first light direction conversion element 13 and suppress a reduction in the amount of fluorescence converted by the wavelength conversion element 25.

[0059] (Embodiment 3) Next, with reference to FIGS. 6 and 7, the light source device 1C according to Embodiment 3 will be described. FIG. 6 is a schematic configuration diagram showing a configuration example of the light source device according to Embodiment 3. FIG. 7 is a partial enlarged view of the first light direction conversion element and the selective reflection element of the light source device according to Embodiment 3.

[0060] The selective reflection element 17 of the light source device 1 in Embodiment 1 separated the light source light Lc0 into the first light Lc1 and the second light Lc2 by utilizing the polarization characteristics of the optical element. However, in the light source device 1C of Embodiment 3, the polarization conversion element 15 is omitted, and the light source light Lc0 is separated into the first light Lc1 and the second light Lc2 by using a triangular prism array. Therefore, the light source light Lc0, the first light Lc1, and the second light Lc2 in Embodiment 3 may be in any polarization state or may be unpolarized light. The configuration of the light source device 1C in Embodiment 3 is the same as that of the light source device 1 in Embodiment 1 except for this point and the points described below.

[0061] The first light direction conversion element 13C includes a dichroic mirror 13Ca that transmits the light source light Lc0 and the first light Lc1 and reflects the third light Lc3, and a slit mirror 13Cb that transmits the light source light Lc0 and reflects the first light Lc1. The dichroic mirror 13Ca and the slit mirror 13Cb may be bonded to each other. The slit mirror 13Cb is disposed closer to the light source element 3a than the dichroic mirror 13Ca.

[0062] The slit mirror 13Cb has a slit portion 13Cba that transmits the light source light Lc0 and a reflection portion 13Cbb that reflects the first light Lc1. The slit portion 13Cba and the reflection portion 13Cbb are arranged alternately. The slit portion 13Cba is, for example, an opening, and the reflection portion 13Cbb is, for example, a dielectric multilayer film or a metal reflection film. The dielectric multilayer film may be formed as the reflection portion 13Cbb on the surface of the slit mirror 13Cb on the side of the dichroic mirror 13Ca.

[0063] The selective reflection element 17C separates the incident light source light Lc0 into a first light Lc1 and a second light Lc2, reflects the separated first light Lc1, and transmits the second light Lc2 and a third light Lc3. The selective reflection element 17C shifts the first light Lc1 to a position different from that of the light source light Lc0 and emits it in a direction opposite to that of the light source light Lc0.

[0064] The selective reflection element 17C includes a first selective reflection portion 17Ca that transmits the third light Lc3, partially reflects the light source light Lc0, and transmits the remainder, and a second selective reflection portion 17Cb that transmits the third light Lc3 and reflects the light reflected by the first selective reflection portion 17Ca in a direction opposite to that of the light source light. The selective reflection element 17C is, for example, a triangular prism array in which triangular prisms are alternately bonded together. The first selective reflection portion 17Ca is one hypotenuse of the triangular prism, and the second selective reflection portion 17Cb is the other hypotenuse of the triangular prism. Thus, the first selective reflection portion 17Ca and the second selective reflection portion 17Cb are each arranged obliquely with respect to the light rays of the incident light source light Lc0.

[0065] As in Embodiment 3, instead of using the polarization characteristics of the optical element, the light source light Lc0 may be separated into the first light Lc1 and the second light Lc2 using a triangular prism array, and the first light Lc1 may be reciprocated between the selective reflection element 17C and the wavelength conversion element 25 to be converted into the third light Lc3. Even with this configuration, similar to the light source device 1 of Embodiment 1, miniaturization of the light source device 1C can be achieved.

[0066] (Embodiment 4) Next, with reference to FIG. 8, the light source device 1D of Embodiment 4 will be described. FIG. 8 is a schematic configuration diagram showing a configuration example of the light source device according to Embodiment 4.

[0067] The light source device 1 of Embodiment 1 includes one light direction conversion element, while the light source device 1B of Embodiment 4 includes two light direction conversion elements. The configuration of the light source device 1D of Embodiment 4 is common to that of the light source device 1 of Embodiment 1 except for this point and the points described below.

[0068] The light source device 1D includes a first light direction conversion element 13D (an example of a second light direction conversion element) and a second light direction conversion element 14 (an example of a first light direction conversion element), so that the light source unit 3 and the wavelength conversion element 25 are arranged on the same side in a plan view with respect to the optical axis emitted from the light source device 1D. The second light direction conversion element 14 is arranged parallel to the first light direction conversion element 13D and on the opposite side of the first light direction conversion element 13D from the selective reflection element 17. Further, the second light direction conversion element 14 is arranged inclined with respect to the traveling direction of the first light Lc1 separated by the selective reflection element 17 and the traveling direction of the third light Lc3 converted by the wavelength conversion element 25.

[0069] The first light direction conversion element 13D has the characteristic of reflecting S-polarized blue light and transmitting P-polarized blue light and yellow light. Therefore, when light source light Lc0, which is, for example, S-polarized blue light, is output from the light source element 3a, the first light direction conversion element 13D reflects the light source light Lc0. Further, the first light direction conversion element 13D transmits the first light Lc1 reflected by the selective reflection element 17. The first light Lc1 that has passed through the first light direction conversion element 13D travels toward the second light direction conversion element 14.

[0070] The second light direction conversion element 14 changes the traveling direction of the incident first light Lc1 by 90 degrees and reflects the first light Lc1 toward the wavelength conversion element 25. The first light Lc1 incident on the wavelength conversion element 25 is converted into the third light Lc3 and travels toward the second light direction conversion element 14. The second light direction conversion element 14 changes the traveling direction of the incident third light Lc3 by 90 degrees and reflects it toward the first light direction conversion element 13D. The third light Lc3 passes through the first light direction conversion element 13D, the polarization conversion element 15, and the selective reflection element 17 and is incident on the condenser lens 19.

[0071] The light source device 1D of Embodiment 4 can also achieve the same effects as the light source device 1 of Embodiment 1. In particular, in the light source device 1D, since both the light source element 3a and the wavelength conversion element 25 are arranged on one side in a plan view with respect to the direction of the light emitted from the light source device 1D, for example, the light source device 1D can be incorporated into a thin projection type video display device.

[0072] (Embodiment 5) Next, with reference to FIG. 9, the light source device 1E of Embodiment 5 will be described. FIG. 9 is a schematic configuration diagram showing a configuration example of the light source device according to Embodiment 5.

[0073] The light source device 1E of Embodiment 5 also includes two light direction conversion elements, similarly to the light source device 1D of Embodiment 4. The configuration of the light source device 1E of Embodiment 5 is common to that of the light source device 1 of Embodiment 1 except for this point and the points described below.

[0074] By including the first light direction conversion element 13E and the second light direction conversion element 14E, the light source unit 3 and the wavelength conversion element 25 are arranged on the same side in a plan view with respect to the optical axis of the light emitted from the light source device 1E.

[0075] The first light direction conversion element 13E is arranged to be inclined with respect to the incident light source light Lc0 so as to reflect the incident light source light Lc0 in a direction opposite to the emission direction from the rod integrator 33. The first light direction conversion element 13E has the characteristic of reflecting the incident light source light Lc0 and transmitting the second light Lc2 and the third light Lc3. For example, the first light direction conversion element 13E is a dichroic polarization separation mirror having the characteristic of reflecting S-polarized blue light and transmitting P-polarized blue light and fluorescence.

[0076] The second light direction conversion element 14E is arranged on the side opposite to the condenser lens 19 with respect to the first light direction conversion element 13E. Further, the second light direction conversion element 14E is arranged to be inclined with respect to the traveling direction of the first light Lc1 separated by the selective reflection element 17 and the traveling direction of the third light Lc3 converted by the wavelength conversion element 25.

[0077] The polarization conversion element 15 and the selective reflection element 17 are arranged between the first light direction conversion element 13E and the second light direction conversion element 14E. The polarization conversion element 15 is arranged on the side of the first light direction conversion element 13E, and the selective reflection element 17 is arranged on the side of the second light direction conversion element 14E, respectively.

[0078] When the light source light Lc0, which is, for example, S-polarized blue light, is output from the light source element 3a, the first light direction conversion element 13E changes the traveling direction of the light source light Lc0, which is S-polarized blue light, by 90 degrees and reflects it. The light source light Lc0 reflected by the first light direction conversion element 13E passes through the polarization conversion element 15 and is converted from S-polarization to circular polarization. The light source light Lc0 converted to circular polarization is partially transmitted as the first light Lc1 and the rest is reflected as the second light Lc2 by the selective reflection element 17.

[0079] The second light Lc2 reflected by the selective reflection element 17 passes through the polarization conversion element 15 and is converted from circular polarization to P-polarization, and enters the condenser element 19 through the first light direction conversion element 13E. The first light Lc1 transmitted through the selective reflection element 17 enters the second light direction conversion element 14E.

[0080] The second light direction conversion element 14E is, for example, a reflection mirror. The second light direction conversion element 14E changes the traveling direction of the incident first light Lc1 by 90 degrees and reflects the first light Lc1 toward the wavelength conversion element 25. The first light Lc1 incident on the wavelength conversion element 25 is converted to the third light Lc3 and travels toward the second light direction conversion element 14E. The second light direction conversion element 14E changes the traveling direction of the incident third light Lc3 by 90 degrees and reflects it toward the first light direction conversion element 13E. The third light Lc3 passes through the selective reflection element 17, the polarization conversion element 15, and the first light direction conversion element 13E and enters the condenser element 19.

[0081] The light source device 1E of the fifth embodiment can also obtain the same effects as the light source device 1 of the first embodiment. Also, the embodiment 1Similarly, in the light source device 1E, since both the light source element 3a and the wavelength conversion element 25 are arranged on one side in a plan view with respect to the direction of the light emitted from the light source device 1E, for example, the light source device 1E can be incorporated into a thin projection type video display device.

[0082] (Embodiment 6) Next, the projection type video display device 101 of Embodiment 6 will be described with reference to FIG. 10. FIG. 10 is a diagram showing the configuration of the projection type video display device according to Embodiment 6.

[0083] The projection type video display device 101 uses, as an image forming means, a transmissive liquid crystal panel of an active matrix type in which a thin film transistor is formed in a pixel region and which is of a TN (Twisted Nematic) mode or a VA (Vertical Alignment) mode. The projection type video display device 101 includes a light source device 1F.

[0084] The light source device 1F includes a first flare lens 51 and a second flare lens 53 instead of the condenser lens 19 and the rod integrator 33 of the light source device 1 of Embodiment 1. Note that the projection type video display device 101 may adopt a modified example of the light source device 1 of Embodiment 1 or the light source devices 1B to 1E of Embodiments 2 to 5 instead of the light source device 1 of Embodiment 1, and may have a configuration including a first flare lens 51 and a second flare lens 53 instead of the condenser lens 19 and the rod integrator 33 in each form.

[0085] The light from the selective reflection element 17 is incident on a first flare lens 51 composed of a plurality of lens elements. The light beam incident on the first flare lens 51 is divided into a number of light beams. The divided number of light beams converge on a second flare lens 53 composed of a plurality of lenses. The lens elements of the first flare lens 51 have an aperture shape similar to that of the liquid crystal panels 217, 218, and 219. The focal lengths of the lens elements of the second flare lens 53 are determined such that the first flare lens 51 and the liquid crystal panels 217, 218, and 219 are in a substantially conjugate relationship. The light emitted from the second flare lens 53 is incident on the polarization conversion element 202.

[0086] The projection type image display device 101 further includes a polarization conversion element 202 for aligning the polarization directions, a superimposing lens 203, a dichroic mirror 204 that transmits red light and reflects green and blue light, a dichroic mirror 205 that reflects green light, reflection mirrors 206, 207, and 208, relay lenses 209 and 210. The projection type image display device 101 further includes field lenses 211, 212, 213, incident side polarizing plates 214, 215, 216, liquid crystal panels 217, 218, and 219 as a light modulation unit, exit side polarizing plates 220, 221, 222, a color combining prism 223 composed of a red reflection dichroic mirror and a blue reflection dichroic mirror, and a projection lens unit 224 (an example of a projection optical system).

[0087] The polarization conversion element 202 is composed of a polarization beam splitter prism and a half-wave plate, and aligns the polarization directions of the third light Lc3, which is natural light from the light source device 1F, and the second light Lc2, which is circularly polarized light, in one polarization direction. The light from the polarization conversion element 202 is incident on the superimposing lens 203. The superimposing lens 203 is a lens for superimposing and illuminating the light emitted from each lens element of the second flare lens 53 onto the liquid crystal panels 217, 218, and 219. The polarization conversion element 202 and the superimposing lens 203 are used as an illumination optical system.

[0088] The light from the superimposing lens 203 is separated into blue, green, and red color lights by the dichroic mirrors 204 for blue and green reflection and 205 for green reflection, which are color separation means. The green light passes through the field lens 211 and the incident-side polarizing plate 214 and is incident on the liquid crystal panel 217. The red light is reflected by the reflection mirror 206, then passes through the field lens 212 and the incident-side polarizing plate 215 and is incident on the liquid crystal panel 218. The blue light passes through and is refracted and reflected by the relay lenses 209 and 210 and the reflection mirrors 207 and 208, passes through the field lens 213 and the incident-side polarizing plate 216, and is incident on the liquid crystal panel 219.

[0089] The three liquid crystal panels 217, 218, and 219 change the polarization state of the incident light by controlling the voltage applied to the pixels according to the video signal, and combine the incident-side polarizing plates 214, 215, 216 and the exit-side polarizing plates 220, 221, 222 arranged on both sides of the respective liquid crystal panels 217, 218, 219 so that the transmission axes are orthogonal to modulate the light and form green, red, and blue images. The color lights transmitted through the exit-side polarizing plates 220, 221, 222 are combined by the color synthesis prism 223. The red and blue color lights are reflected by the dichroic mirror for red reflection and the dichroic mirror for blue reflection respectively, and are combined with the green color light and incident on the projection lens unit 224. The projection lens unit 224, which is a projection optical system, includes a plurality of lenses, and the light incident on the projection lens unit 224 is enlarged and projected onto a screen (not shown).

[0090] According to the projection type video display device 101 of Embodiment 6, since the light source device 1F is miniaturized, the degree of freedom in arranging the light source device 1F can be improved. As a result, the projection type video display device 101 can be miniaturized.

[0091] (Embodiment 7) Next, referring to FIG. 11, the projection type video display device 101A of Embodiment 7 will be described. FIG. 11 is a diagram showing the configuration of the projection type video display device 101A according to Embodiment 7. The projection type video display device 101A of Embodiment 7 uses the light source device 1 of Embodiment 1, but a modified example of the light source device 1 of Embodiment 1 or the light source devices 1B to 1E of Embodiments 2 to 5 may be used instead of the light source device 1 of Embodiment 1. The projection type video display device 101A of Embodiment 7 is a so-called three-chip type projection type video display device.

[0092] The light emitted from the rod integrator 33 is imaged onto the DMDs (Digital Micro Mirror Devices) 311, 312, and 313 as light modulation units by a relay lens system composed of the convex lenses 301, 302, and 303.

[0093] The light emitted from the relay lens system composed of the convex lenses 301, 302, and 303 enters the total reflection prism 304 provided with the minute gap 305. The light that is emitted from the relay lens system and enters the total reflection prism 304 at an angle equal to or greater than the total reflection angle is reflected by the minute gap 305 to change the traveling direction of the light, and then enters the color prism 306 composed of three glass blocks provided with minute gaps.

[0094] Of the first light Lc1 which is blue light incident from the total reflection prism 304 and the third light Lc3 which is fluorescence in the first glass block of the color prism 306, the blue light is first reflected by a reflection film with spectral characteristics having blue reflection characteristics provided in front of the minute gap 307. Then, the reflected blue light changes its traveling direction and travels toward the total reflection prism 304, enters the minute gap 308 provided between the total reflection prism 304 and the color prism 306 at an angle equal to or greater than the total reflection angle, and enters the DMD 313 for displaying a blue image.

[0095] Subsequently, the minute gap 307 into Of the transmitted third light Lc3, the red light is reflected by a reflection film with spectral characteristics provided between the second and third glass blocks of the color prism 306, which has the spectral characteristics of reflecting light in the red wavelength region and transmitting green light, and its traveling direction is changed toward the first glass block side.

[0096] The red light whose traveling direction has been changed is reflected again by the micro gap 307 provided between the first and second glass blocks of the color prism 306, its traveling direction is changed, and it is incident on the DMD 312 for red.

[0097] Also, of the third light Lc3 that has passed through the micro gap 307, the green light passes through a reflection film with spectral characteristics provided between the second and third glass blocks of the color prism, which has the spectral characteristics of reflecting light in the red wavelength region and transmitting green light, travels straight to the third glass block, and is incident on the DMD 311 for green as it is.

[0098] The DMDs 311, 312, and 313 change the traveling direction of light by changing the direction of the mirror for each pixel according to the video signal of each color from a video circuit (not shown).

[0099] The green light whose traveling direction has been changed according to the video signal by the DMD 311 for green is incident on the third glass block of the color prism 306 and passes through the reflection film with spectral characteristics provided between the third and second glass blocks of the color prism 306.

[0100] The red light whose traveling direction has been changed according to the video signal by the DMD 312 for red is incident on the second glass block of the color prism 306 and is reflected by entering the micro gap 307 provided between the second and first glass blocks of the color prism 306 at an angle equal to or greater than the total reflection angle. After that, the red light changes its traveling direction to the third glass block of the color prism, is reflected by the reflection film with spectral characteristics provided between the second and third glass blocks of the color prism 306, changes its traveling direction, and is combined with the green light.

[0101] The light synthesized by the reflection film with spectral characteristics travels toward the first glass block side of the color prism 306, and is incident on the minute gap 307 provided between the second and first glass blocks of the color prism 306 at an angle equal to or less than the total reflection angle, thereby passing through.

[0102] Furthermore, the blue light whose traveling direction has been changed in accordance with the video signal by the DMD 313 for blue is incident on the first glass block of the color prism 306, travels toward the total reflection prism 304 side, and is incident on the gap 308 provided between the total reflection prism 304 and the color prism 306 at an angle equal to or greater than the total reflection angle, and thus travels toward the second glass block side of the color prism 306. Thereafter, the blue light is reflected by the mirror with spectral characteristics provided on the first glass block side before the minute gap 307 provided between the first and second glass blocks of the color prism 306, changes the traveling direction of the light toward the total reflection prism 304 side, is synthesized with the light from the DMD 311 for green and the DMD 312 for red, and is incident on the total reflection prism 304.

[0103] The light from the DMDs 311, 312, and 313 incident on the total reflection prism 304 passes through the total reflection prism 304, is incident on the projection lens unit 321 as a projection optical system, and is irradiated onto a screen (not shown).

[0104] According to the projection type video display device 101A in the seventh embodiment, since the light source device 1 F is miniaturized, the degree of freedom in arranging the light source device 1F can be improved. Thereby, the projection type video display device 101 can be miniaturized.

[0105] The projection type video display device 101A in the seventh embodiment is a three-chip type projection type video display device, but may be a two-chip type projection type video display device 101B as shown in FIG. 12. In this case, the wavelength conversion element 25G of the light source device 1G in the projection type video display device 101B Figure 12As shown in FIG. 1, the DMD 314 includes a wavelength conversion layer 29Ga that generates fluorescence in a green wavelength range from the incident first light Lg1, and a wavelength conversion layer 29Gc that generates fluorescence in a red wavelength range from the first light Lg1. The wavelength conversion layers 29Ga and 29Gc each have a semicircular annular segment shape. The DMD 314 emits an image in a time-division manner in synchronization with the rotation of the wavelength conversion element 25G.

[0106] (Other embodiments) As described above, the above-mentioned embodiment has been described as an example of the technology in the present disclosure. For that purpose, the attached drawings and the detailed description have been provided. Therefore, among the components described in the attached drawings and the detailed description, not only components essential for solving the problem but also components that are not essential for solving the problem in order to exemplify the above technology may be included. Therefore, the fact that the non-essential components are described in the attached drawings or the detailed description should not be used to immediately determine that the non-essential components are essential.

[0107] Furthermore, the technology in the present disclosure is not limited to the above-described embodiment, but can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. Also, it is possible to combine the components described in the above-described embodiment to form a new embodiment.

[0108] Furthermore, since the above-described embodiments are intended to illustrate the technology in the present disclosure, various modifications, substitutions, additions, omissions, and the like can be made within the scope of the claims or their equivalents.

[0109] (Outline of the embodiment) (1) The light source device of the present disclosure includes a light source element that outputs light source light which is light in a first wavelength range, and a selective reflection element that reflects a part of the light source light and transmits the remaining light source light, thereby separating the light source light into first light and second light, and transmitting third light which is light in a second wavelength range. A first light direction conversion element is disposed at a position that receives the first light emitted from the selective reflection element in a first direction, and reflects the first light and the third light. A wavelength conversion element is disposed at a position that receives the light reflected in a second direction by the first light direction conversion element, and converts the incident first light into third light. The first light emitted from the selective reflection element is reflected in the second direction by the first light direction conversion element and then enters the wavelength conversion element. The third light emitted from the wavelength conversion element is reflected in a third direction opposite to the first direction by the first light direction conversion element and then enters the selective reflection element. From the selective reflection element, the second light and the third light are emitted in the third direction. The light source element outputs the light source light in a direction different from the second direction.

[0110] Since the selective reflection element separates the light source light into first light and second light, transmits third light which is light in a second wavelength range, and emits the second light and the third light in the third direction, the second light and the third light can be emitted from the light source device simultaneously. In addition, since it is not necessary to arrange the light source element and the wavelength conversion element to face each other, the light source device can be miniaturized.

[0111] (2) In the light source device of (1), the reflectance of the light source light of the selective reflection element is 70% or more, and the transmittance of the third light is 95% or more.

[0112] (3) In the light source device of (1) or (2), a condensing element is provided at a position that receives the light emitted from the selective reflection element in the third direction.

[0113] (4) In any one of the light source devices of (1) to (3), the reflectance of the light source light of the selective reflection element continuously changes along a predetermined direction, and by moving in the predetermined direction, the ratio of the first light and the second light emitted is changed.

[0114] (5) In any one of the light source devices (1) to (4), the selective reflection element is composed of a single dichroic mirror.

[0115] (6) In any one of the light source devices (1) to (5), it includes a polarization conversion element arranged in the optical path from the light source element to the selective reflection element.

[0116] (7) In the light source device of (6), the polarization conversion element includes two quarter-wave plates with non-coincident slow axes, and mutually converts linearly polarized light and elliptically polarized light.

[0117] (8) In any one of the light source devices (1) to (4), the selective reflection element is arranged obliquely with respect to the light rays of the incident light source light, and includes a first selective reflection portion that transmits the third light, partially reflects the light source light, and transmits the rest, and a second selective reflection portion that transmits the third light and reflects the light reflected by the first selective reflection portion in the direction opposite to the light source light. The first light or the second light is output in a position shifted from the light source light and in the direction opposite to the light source light.

[0118] (9) In any one of the light source devices (1) to (8), the light source element outputs the light source light in the third direction.

[0119] (10) In any one of the light source devices (1) to (8), it includes a second light direction conversion element that reflects the light source light toward the selective reflection element and transmits the third light.

[0120] (11) In the light source device of (10), the light source element outputs the light source light in the direction opposite to the second direction.

[0121] (12) The projection type video display device of the present disclosure includes any one of the light source devices (1) to (11), a light modulation unit that generates video light using the second light and the third light emitted from the light source device, and a projection optical system that projects the video light.

[0122] By providing a light source device capable of miniaturization, a projection type video display device capable of miniaturization can be provided.

[0123] (13)(12) The projection type video display device includes two or more light modulation units.

Industrial Applicability

[0124] The present disclosure can be used for a light source device that uses light wavelength-converted by a wavelength conversion element and a projection type video display device.

Explanation of Signs

[0125] 1, 1A, 1B, 1C, 1D, 1E, 1F Light source device 3 Light source unit 3a Light source element 3b Collimator lens 5 Convex lens 7 Diffuser 11 Concave lens 13, 13C, 13D, 13E First light direction conversion element 13Ca Dichroic mirror 13Cb Slit mirror 13Cba Slit portion 13Cbb Reflection portion 14, 14E Second light direction conversion element 15, 15B Polarization conversion element 15Ba First quarter-wave plate 15Bb Second quarter-wave plate 17, 17A, 17C Selective reflection element 17Ca First selective reflection portion 17Cb Second selective reflection portion 18 Slide mechanism 19 Condensing element 21 Condensing lens 23 Condensing lens 25, 25G Wavelength conversion element 27 Substrate 29, 29Ga, 29Gc Wavelength conversion layer 31 Motor 33 Rod integrator 51 First flare lens 53 Second flare lens 101, 101A, 101B Projection type video display device 202 Polarization conversion element Lc0 Light source light Lc1 First light Lc2 Second light Lc3 Third light

Claims

1. A light source element that outputs light source light which is light in a first wavelength range; A selective reflection element that separates the light source light into first light and second light by reflecting a part of the light source light and transmitting the remainder of the light source light; A first light direction conversion element that is disposed at a position to receive the first light emitted from the selective reflection element in a first direction and reflects the first light in a second direction; A wavelength conversion element that is disposed at a position to receive the first light reflected in the second direction by the first light direction conversion element and converts the first light into third light which is light in a second wavelength range, and comprising: The first light direction conversion element reflects the third light emitted from the wavelength conversion element in a third direction opposite to the first direction; The selective reflection element transmits the third light reflected by the first light direction conversion element; From the selective reflection element, the second light and the third light are emitted in the third direction, and the light source light output from the light source element is incident on the first light direction conversion element in the third direction; A light source device.

2. A light source element that outputs light source light which is light in a first wavelength range; A selective reflection element that separates the light source light into first light and second light by reflecting a part of the light source light and transmitting the remainder of the light source light; A second light direction conversion element that is disposed at a position to receive the first light that has passed through a first light direction conversion element which is emitted from the selective reflection element in a first direction and reflects the light source light toward the selective reflection element, and reflects the first light in a second direction; A wavelength conversion element that is disposed at a position to receive the first light reflected in the second direction by the second light direction conversion element and converts the first light into third light which is light in a second wavelength range, and comprising: The second light direction conversion element reflects the third light emitted from the wavelength conversion element in a third direction opposite to the first direction; The selective reflection element and the first light direction conversion element transmit the third light reflected by the second light direction conversion element; From the selective reflection element, the second light and the third light are emitted in the third direction, and the light source light output from the light source element is incident on the first light direction conversion element in a direction opposite to the second direction; A light source device.

3. Further comprising a condensing element disposed at a position to receive the light emitted from the selective reflection element in the third direction The light source device according to claim 1 or 2.

4. The reflectivity of the selective reflection element with respect to the light source light is 70% or more, and the transmittance of the selective reflection element with respect to the third light is 95% or more. The light source device according to claim 1 or 2.

5. The selective reflection element is configured such that the reflectivity of the selective reflection element with respect to the light source light continuously changes along a predetermined direction, and by moving the selective reflection element in the predetermined direction, the ratio of the first light and the second light emitted from the selective reflection element changes. The light source device according to claim 1 or 2.

6. The selective reflection element is composed of a single dichroic mirror. The light source device according to claim 1 or 2.

7. The light source device further includes a polarization conversion element disposed in the optical path from the light source element to the selective reflection element. The light source device according to claim 1 or 2.

8. The polarization conversion element includes a first quarter-wave plate having a first slow axis, and a second quarter-wave plate having a second slow axis that does not coincide with the first slow axis, and a set of the first quarter-wave plate and the second quarter-wave plate convert linearly polarized light into elliptically polarized light and convert elliptically polarized light into linearly polarized light. The light source device according to claim 7.

9. The selective reflection element includes a first selective reflection portion that is disposed obliquely with respect to the light rays of the light source light incident on the selective reflection element, transmits the third light, reflects a part of the light source light, and transmits the remainder of the light source light, and a second selective reflection portion that transmits the third light and reflects a part of the light source light reflected by the first selective reflection portion in a direction opposite to the light source light, and the selective reflection element shifts the first light to a position different from the light source light and emits it in a direction opposite to the light source light. The light source device according to claim 1 or 2.

10. The light source element outputs the light source light in the third direction. The light source device according to claim 1 or 2.

11. The light source device further includes a second light direction conversion element that reflects the light source light toward the selective reflection element and transmits the third light. The light source device according to claim 1 or 2.

12. The light source element outputs the light source light in a direction opposite to the second direction. The light source device according to claim 10.

13. The light source light is blue light, and the third light is yellow light. The light source device according to claim 1 or 2.

14. The light source device according to claim 1 or 2, an optical modulation unit that generates image light using the second light and the third light emitted from the light source device, and a projection optical system that projects the image light. A projection type image display device.

15. The optical modulation unit includes two or more optical modulation units. The projection type image display device according to claim 14.

Images