Light source device and projector

Abstract

To provide a light source device and a projector capable of miniaturizing a device configuration.SOLUTION: A light source device according to the present disclosure includes a light source configured to emit first light having a first wavelength band, a first optical system which the first light emitted from the light source enters, a light collection optical system which the first light having passed through the first optical system enters, and a wavelength conversion element configured to convert a part of the first light into second light having a second wavelength band different from the first wavelength band. The first optical system includes a first optical element and a second optical element, the first optical element includes a second reflective film that reflects another part of the first light and a diffusion layer that diffuses another part of the first light, and the second optical element includes a third reflective film that reflects the second light.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Conventionally, a light source device has been proposed that separates blue light emitted from a light source, and emits white light by combining yellow fluorescence generated by making some of the separated blue light incident on a phosphor, with blue light obtained by diffusing the remaining part of the separated blue light (see, for example, Patent Document 1 below). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-13764 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above light source device, the optical path of some of the blue light heading toward the phosphor is different from the optical path of the other part of the blue light heading toward the diffuser plate, which necessitates the placement of optical components in each optical path, resulting in an increase in the size of the device configuration. [Means for solving the problem]

[0005] In order to solve the above problem, according to a first aspect of the present invention, there is provided a light source device comprising: a light source that emits first light having a first wavelength band; a first optical system into which the first light emitted from the light source is incident; a focusing optical system into which the first light that has passed through the first optical system is incident; and a wavelength conversion element that converts a portion of the first light into a second light of a second wavelength band different from the first wavelength band, wherein the wavelength conversion element has a wavelength conversion layer having a light incident surface onto which the first light is incident, and a second reflective film provided on the light incident surface to separate the first light into the first portion and another portion, wherein the first optical system has a first optical element and a second optical element, wherein the first optical element has a second reflective film that reflects the other portion of the first light and a diffusion layer that diffuses the other portion of the first light, and the second optical element has a third reflective film that reflects the second light.

[0006] According to a second aspect of the present invention, there is provided a projector comprising the light source device of the first aspect, a light modulation device that modulates light incident from the light source device in accordance with image information, and a projection optical device that projects the light modulated by the light modulation device. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a projector according to a first embodiment. [Figure 2] FIG. 2 is a schematic diagram illustrating a configuration of a light source device. [Figure 3] FIG. 10 is a schematic diagram showing the configuration of a light source device according to a modified example. [Figure 4] FIG. 10 is a schematic diagram showing the configuration of a light source device according to a second embodiment. [Figure 5] FIG. 10 is a diagram showing the configuration of a modified example of the wavelength conversion element of the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In each drawing, the scale of the dimensions of some components may be changed to make each component easier to see.

[0009] (First embodiment) First, a projector according to a first embodiment of the invention will be described with reference to Fig. 1. Fig. 1 is a schematic diagram showing the configuration of a projector 1 according to the first embodiment. As shown in Fig. 1, projector 1 is a projection-type image display device that displays an image on a screen SCR. Projector 1 includes a light source device 2, a color separation optical system 3, light modulation devices 4R, 4G, and 4B, a color synthesis optical system 5, and a projection optical device 6. Projector 1 is a three-plate projector that has three light modulation devices.

[0010] The light source device 2 emits white illumination light WL toward the color separation optical system 3. The illumination light WL is illumination light in the projector 1, and includes red light LR, green light LG, and blue light LB. The configuration of the light source device 2 will be described later.

[0011] The color separation optical system 3 separates the illumination light WL into red light LR, green light LG, and blue light LB. The color separation optical system 3 includes, for example, a first dichroic mirror 11, a second dichroic mirror 12, a first reflecting mirror 13, a second reflecting mirror 14, a third reflecting mirror 15, a first relay lens 16, and a second relay lens 17.

[0012] The first dichroic mirror 11 is disposed on the optical path of the illumination light WL emitted from the light source device 2, and separates the incident illumination light WL into red light LR, green light LG, and blue light LB. The first dichroic mirror 11 transmits the red light LR and reflects the green light LG and blue light LB. The second dichroic mirror 12 is disposed on the common optical path of the green light LG and blue light LB emitted from the first dichroic mirror 11, and separates the green light LG from the blue light LB. The second dichroic mirror 12 transmits the blue light LB and reflects the green light LG.

[0013] The first reflecting mirror 13 reflects the red light LR toward the light modulation device 4R. The second reflecting mirror 14 and the third reflecting mirror 15 guide the blue light LB to the light modulation device 4B. The green light LG is reflected from the second dichroic mirror 12 toward the light modulation device 4G. The red light LR, green light LG, and blue light LB contained in the illumination light WL correspond to the light emitted from the light source device 2.

[0014] The first relay lens 16 is disposed on the optical path of the blue light LB between the second dichroic mirror 12 and the second reflecting mirror 14. The second relay lens 17 is disposed on the optical path of the blue light LB between the second reflecting mirror 14 and the third reflecting mirror 15. By disposing the first relay lens 16 and the second relay lens 17 as described above, optical loss of the blue light LB is compensated for. The optical loss of the blue light LB occurs because the optical path length of the blue light LB from the first dichroic mirror 11 to the optical modulation device 4B is longer than the optical path length of the red light LR from the first dichroic mirror 11 to the optical modulation device 4R and the optical path length of the green light LG from the first dichroic mirror 11 to the optical modulation device 4G.

[0015] The light modulation device 4R is disposed on the optical path of the red light LR reflected by the first reflecting mirror 13 and emitted from the first reflecting mirror 13. The light modulation device 4R modulates the incident red light LR in accordance with image information input from an image input device (not shown), forms red image light, and emits the red image light. The light modulation device 4G is disposed on the optical path of the green light LG reflected by the second dichroic mirror 12 and emitted from the second dichroic mirror 12. The light modulation device 4G modulates the incident green light LG in accordance with image information input from an image input device (not shown), forms green image light, and emits the green image light. The light modulation device 4B is disposed on the optical path of the blue light LB reflected by the third reflecting mirror 15 and emitted from the third reflecting mirror 15. The light modulation device 4B modulates the incident blue light LB in accordance with image information input from an image input device (not shown), forms blue image light, and emits the blue image light. The image input device may be, for example, a personal computer or a portable terminal device.

[0016] Each of the light modulation devices 4R, 4G, and 4B uses, for example, a transmissive liquid crystal panel. Polarizing plates (not shown) are arranged on the incident and exit sides of the liquid crystal panel. A field lens 7R is arranged on the optical path of the red light LR between the first reflecting mirror 13 and the light modulation device 4R. A field lens 7G is arranged on the optical path of the green light LG between the second dichroic mirror 12 and the light modulation device 4G. A field lens 7B is arranged on the optical path of the blue light LB between the third reflecting mirror 15 and the light modulation device 4B.

[0017] The color combining optical system 5 is disposed across the optical path of the red image light emitted from the light modulation device 4R, the optical path of the green image light emitted from the light modulation device 4G, and the optical path of the blue image light emitted from the light modulation device 4B. When viewed from the top or side as shown in FIG. 1 , the combining position of the colored lights in the color combining optical system 5 overlaps with the intersection of the optical paths of the red image light, the green image light, and the blue image light. In the color combining optical system 5, the red image light, the green image light, and the blue image light are combined together to form colored image light. The color combining optical system 5 emits colored image light. For example, a cross dichroic prism is used for the color combining optical system 5.

[0018] The projection optical device 6 is disposed on the optical path of the color image light emitted from the color combining optical system 5. The color image light emitted from the color combining optical system 5 corresponds to light modulated by the light modulation devices 4R, 4G, and 4B. The projection optical device 6 enlarges and projects the color image light emitted from the color combining optical system 5 and incident thereon onto the screen SCR. The color image light enlarged and projected from the projection optical device 6 is displayed as a color image on the display surface of the screen SCR opposite the emission surface of the projection optical device 6.

[0019] The projection optical device 6 is configured, for example, by a plurality of optical lenses, but may also be configured by a single optical lens. Optical lenses include various lenses such as plano-convex lenses, biconvex lenses, meniscus lenses, aspherical lenses, rod lenses, and free-form lenses.

[0020] Next, a light source device 2 according to one embodiment of the present invention will be described. Fig. 2 is a schematic diagram showing the configuration of the light source device 2 according to this embodiment. 2 and the following drawings, the components of the light source device 2 will be described using an XYZ coordinate system as necessary. The X axis is parallel to the illumination optical axis AX of the light source device 2, the Y axis is parallel to the optical axes ax1 and ax2 of the light source device 2, and the Z axis is perpendicular to the X axis and the Y axis. In other words, the optical axes ax1 and ax2 and the illumination optical axis AX are in the same plane, and the optical axes ax1 and ax2 are perpendicular to the illumination optical axis AX.

[0021] As shown in FIG. 2, the light source device 2 includes a light source 20, a first optical system 30, a focusing optical system 40, a wavelength conversion element 50, an optical path adjustment optical system 60, and a uniform illumination optical system .

[0022] In the light source device 2 of this embodiment, the light source 20, the first optical system 30, the focusing optical system 40, and the wavelength conversion element 50 are arranged along an optical axis ax1, which is the optical path of the chief ray of blue light K1 emitted from the light source 20. In addition, the wavelength conversion element 50, the focusing optical system 40, and the first optical system 30 are arranged along an optical axis ax2, which is the optical path of the chief ray of blue reflected light RB (described below) emitted from the wavelength conversion element 50. In addition, the first optical system 30 and the optical path adjustment optical system 60 are arranged in the X-axis direction along the illumination optical axis AX.

[0023] The light source 20 includes a plurality of light-emitting units 21 and a plurality of collimating lenses 22. Each of the light-emitting units 21 is composed of a semiconductor laser. The light-emitting units 21 are arranged in an array in the XZ plane perpendicular to the optical axis ax1. Each light-emitting unit 21 emits blue light ray B, which is a light beam having a peak wavelength of, for example, 445 nm. Note that a semiconductor laser that emits light ray B with a wavelength other than 445 nm (for example, 460 nm) can also be used as the light-emitting unit 21.

[0024] The plurality of collimating lenses 22 are arranged, for example, in an array. The plurality of collimating lenses 22 are arranged corresponding to the plurality of light-emitting units 21, respectively. The collimating lenses 22 convert the light beam B emitted from the corresponding light-emitting unit 21 into parallel light.

[0025] In this way, the light source 20 emits blue light K1 as a parallel light beam having a blue wavelength band (first wavelength band) including a plurality of light rays B.

[0026] The blue light K1 emitted from the light source 20 is incident on the first optical system 30. The configuration of the first optical system 30 will be described in detail later. The blue light K1 passes through the first optical system 30 and enters the condensing optical system 40. The condensing optical system 40 includes at least one lens 41 having positive power. The lens 41 having positive power is formed of, for example, a convex lens or a plano-convex lens. The light-collecting optical system 40 has a function of collecting the blue light K1 toward the wavelength conversion element 50, and a function of picking up the light emitted from the wavelength conversion element 50 and collimating it.

[0027] The optical axis ax1 of the blue light K1 that passes through the first optical system 30 and enters the focusing optical system 40 is offset from the central axis 40C of the focusing optical system 40. The central axis 40C of the focusing optical system 40 is an axis that passes through the center of the lens 41, and when the focusing optical system 40 is made up of multiple lenses, it is an axis that passes through the centers of each of the multiple lenses.

[0028] In this embodiment, the optical axis ax1 of the blue light K1 is shifted toward the +X side in the XY plane with respect to the central axis 40C of the light collecting optical system 40. For this reason, the blue light K1 is incident on the wavelength conversion element 50 from an oblique direction relative to the center of the wavelength conversion element 50 in the XY plane. In this embodiment, it is preferable that the blue light K1 does not overlap with the central axis 40C of the focusing optical system 40, and is incident only on an area on the -X side of the central axis 40C of the focusing optical system 40. In this way, the reflected component of the blue light K1 by the wavelength conversion element 50 can be efficiently extracted from the +X side of the central axis 40C, and the reflected component of the blue light K1 can be efficiently incident on the focusing optical system 40.

[0029] The wavelength conversion element 50 converts a part of the blue light K1 into fluorescent light Y. The wavelength conversion element 50 includes a wavelength conversion layer 51, a light separation film 52, a substrate 53, and a reflecting member 54. The blue light K1 of the present embodiment corresponds to an example of the "first light" of the present invention, the fluorescence Y of the present embodiment corresponds to an example of the "second light" of the present invention, and the light separation film 52 of the present embodiment corresponds to an example of the "first reflective film" of the present invention.

[0030] The wavelength conversion layer 51 contains a ceramic phosphor that converts blue light K1 in a first wavelength band into fluorescence Y in a second wavelength band different from the first wavelength band. The second wavelength band is, for example, 490 to 750 nm, and the fluorescence Y is yellow light containing a green light component and a red light component. The phosphor may contain a single crystal phosphor.

[0031] The substrate 53 functions as a support substrate that supports the reflecting member 54 and the wavelength conversion layer 51, and also functions as a heat dissipation substrate that dissipates heat generated in the wavelength conversion layer 51. The substrate 53 is made of a material with high thermal conductivity, such as metal or ceramic. The substrate 53 may be provided with a heat dissipation member, such as a heat sink, on the surface opposite to the surface that supports the wavelength conversion layer 51.

[0032] The reflecting member 54 is provided between the substrate 53 and the wavelength conversion layer 51, and reflects the fluorescence Y incident from the wavelength conversion layer 51 toward the wavelength conversion layer 51. The reflecting member 54 is made of a laminated film including, for example, a dielectric multilayer film, a metal mirror, and a reflection-enhancing film.

[0033] The wavelength conversion layer 51 includes a light exit surface 51a onto which the blue light K1 is incident and from which the fluorescent light Y exits, and a back surface 51b facing the substrate 53. The wavelength conversion layer 51 contains, for example, an yttrium-aluminum-garnet (YAG) phosphor. Taking YAG:Ce, which contains cerium (Ce) as an activator, as an example, the phosphor can be a material obtained by mixing raw material powders containing constituent elements such as Y2O3, Al2O3, and CeO3 and subjecting them to a solid-phase reaction; Y-Al-O amorphous particles obtained by a wet method such as a coprecipitation method or a sol-gel method; or YAG particles obtained by a gas-phase method such as a spray-drying method, a flame pyrolysis method, or a thermal plasma method.

[0034] The light separating film 52 is provided on the light exit surface 51a of the wavelength conversion layer 51. The light exit surface 51a of the wavelength conversion layer 51 is substantially flat, and the light separating film 52 is also made of a flat film. The light separating film 52 is made of a dielectric multilayer film having optical properties of transmitting a portion of the blue light K1 and the fluorescence Y and reflecting another portion of the blue light K1. In this embodiment, if the transmittance of the blue light K1 through the light separating film 52 is set to, for example, 20%, the light separating film 52 transmits a portion (20%) of the blue light K1 and reflects another portion (80%) of the blue light K1, thereby separating the blue light K1 into one portion and another portion.

[0035] A portion of the blue light K1 that has passed through the light separation film 52 enters the wavelength conversion layer 51 as excitation light and is converted into fluorescence Y. The fluorescence Y passes through the light separation film 52 provided on the light exit surface 51a of the wavelength conversion layer 51 and is emitted from the wavelength conversion element 50. The fluorescence Y is emitted in all directions at a wide radiation angle by Lambertian emission approximately centered in the Y-axis direction. The focusing optical system 40 of this embodiment is disposed so that the emission center of the fluorescence Y coincides with the central axis 40C. Therefore, the focusing optical system 40 can efficiently capture the fluorescence Y that has been emitted at a wide radiation angle by Lambertian emission. The fluorescence Y is substantially collimated by the focusing optical system 40, and the chief ray of the fluorescence Y travels along the central axis 40C and enters the first optical system 30. The fluorescence Y that has entered the first optical system 30 is reflected by a second optical element 32 (described later), travels along the illumination optical axis AX, and enters the optical path adjustment optical system 60.

[0036] Meanwhile, another portion of the blue light K1 reflected by the light separation film 52 is emitted from the wavelength conversion element 50 together with the fluorescent light Y toward the light collection optical system 40. The other portion of the blue light K1 is blue component light that, together with the yellow fluorescent light Y, generates white illumination light WL.

[0037] In the following description, the other part of the blue light K1 reflected by the light separating film 52 may be referred to as blue reflected light RB. In other words, the blue reflected light RB corresponds to an example of "the other part of the first light" in the present invention.

[0038] As described above, according to the light source device 2 of the present embodiment, the optical path of the fluorescence Y emitted from the wavelength conversion element 50 and incident on the first optical system 30 is aligned with the optical path of the blue reflected light RB reflected by the light separation film 52 and incident on the first optical system 30, so that the light collecting optical system 40 can also be used as an optical system that picks up the fluorescence Y and the blue reflected light RB. With this configuration, compared to a configuration in which a separate optical path for the fluorescence and a separate optical path for the blue component of the illumination light are provided, and multiple light collecting optical systems are required, the device configuration can be made more compact by sharing part of the optical path and using the light collecting optical system 40 in common.

[0039] As described above, the blue light K1 is incident on the wavelength conversion element 50 from an oblique direction and is specularly reflected by the light separation film 52. Therefore, the reflected blue light RB, which is a reflected component of the blue light K1, is incident on the focusing optical system 40 through an optical path different from the optical path of the blue light K1 relative to the wavelength conversion element 50. The reflected blue light RB is collimated by the focusing optical system 40, travels along the optical axis ax2, and is incident on the first optical system 30.

[0040] The first optical system 30 includes a first optical element 31 and a second optical element 32. The first optical element 31 and the second optical element 32 are arranged to form an angle of 45° with respect to the optical axis ax1 of the blue light K1. The first optical element 31 is arranged on the light source 20 side relative to the second optical element 32. The second optical element 32 is arranged on the wavelength conversion element 50 side relative to the first optical element 31.

[0041] The first optical element 31 transmits blue light K1 emitted from the light source 20. The first optical element 31 has a light-transmitting substrate 310, a blue reflective film 311, and a diffusion layer 312. The blue reflective film 311 of this embodiment corresponds to an example of the "second reflective film" of the present invention.

[0042] The translucent substrate 310 is made of a translucent substrate such as glass or plastic, and has a first surface 310a onto which the blue light K1 emitted from the light source 20 is incident, and a second surface 310b opposite to the first surface 310a.

[0043] Blue reflective film 311 is disposed on a part of first surface 310a of light-transmitting substrate 310. Blue reflective film 311 is made of a dichroic mirror that reflects at least blue light K1 having a blue wavelength band.

[0044] The diffusion layer 312 is disposed over the entire second surface 310b of the light-transmitting substrate 310. The diffusion layer 312 is a transmissive diffusion layer that transmits and diffuses blue light K1.

[0045] In this embodiment, the blue light K1 emitted from the light source 20 and the reflected blue light RB are incident on different regions of the first optical element 31. The first surface 310a of the light-transmitting substrate 310 includes a first region 31A and a second region 31B. The first region 31A is a region where the blue reflective film 311 is disposed. The second region 31B is a region that transmits blue light K1 incident from the light source 20.

[0046] The second surface 310b of the light-transmitting substrate 310 includes a third region 31C and a fourth region 31D. The third region 31C is a region where the diffusion layer 312 is arranged, facing the second region 31B of the first surface 310a, and is a region that transmits the blue light K1 emitted from the light source 20. The fourth region 31D is a region where the diffusion layer 312 is arranged, facing the first region 31A of the first surface 310a, and is a region through which the reflected blue light RB passes.

[0047] In this embodiment, the light source 20 and the first optical element 31 are aligned with each other so that the blue light K1 emitted from the light source 20 is incident on the second region 31B of the first surface 310a of the light-transmitting substrate 310. In addition, the wavelength conversion element 50 and the first optical element 31 are aligned with each other so that the blue reflected light RB emitted from the wavelength conversion element 50 is incident on the fourth region 31D of the second surface 310b of the light-transmitting substrate 310.

[0048] The blue reflected light RB passes through the diffusion layer 312, enters the first region 31A of the first surface 310a from the fourth region 31D of the second surface 310b of the light-transmitting substrate 310, and is reflected by the blue reflective film 311 provided in the first region 31A. The chief ray of the blue reflected light RB after reflection by the blue reflective film 311 travels along the X-axis. The blue reflected light RB reflected by the blue reflective film 311 passes through the first region 31A and the fourth region 31D of the light-transmitting substrate 310 and enters the diffusion layer 312. Therefore, the blue reflected light RB, which is the other part of the blue light K1 separated by the light separating film 52, passes through the diffusion layer 312 twice in the first optical element 31. In other words, the blue reflected light RB, which is the other part of the first light emitted from the light source 20, passes through the diffusion layer 312 three times and is diffused.

[0049] In this embodiment, the blue light K1 is a laser beam, which is highly coherent and easily generates visible interference fringes and speckle noise. In contrast, in this embodiment, the light is sufficiently diffused by passing through the diffusion layer 312 three times, making it possible to make interference fringes and speckle noise less noticeable even when using blue light K1 made of laser light.

[0050] In the light source device 2 of this embodiment, the fluorescence Y and the reflected blue light RB emitted from the wavelength conversion element 50 are collimated by the focusing optical system 40 and enter the second optical element 32. The second optical element 32 includes a dichroic film 32a that transmits the blue light K1 of the first wavelength band and reflects the fluorescence Y. That is, the second optical element 32 transmits the blue light K1 emitted from the light source 20 and the reflected blue light RB emitted from the wavelength conversion element 50. Therefore, the fluorescence Y is reflected by the second optical element 32 toward the +X side and travels along the illumination optical axis AX. The dichroic film 32a of this embodiment corresponds to an example of the "third reflective film" of the present invention.

[0051] In the light source device 2 of this embodiment, the blue reflected light RB and fluorescence Y that pass through the first optical system 30 are emitted in the same direction (X-axis direction). That is, the direction in which the blue reflected light R is emitted from the first optical element 31 is the same as the direction in which the fluorescence Y is emitted from the second optical element 32. With this configuration, the blue reflected light R and fluorescence Y are emitted in the same direction, so that white illumination light WL containing the blue reflected light R and fluorescence Y can be efficiently generated.

[0052] The light source device 2 of this embodiment further includes an optical path adjusting optical system 60 into which the illumination light WL, which includes the blue reflected light RB and the fluorescent light Y emitted from the first optical system 30, is incident. The optical path adjustment optical system 60 includes a first mirror 61 and a second mirror 62 .

[0053] The first mirror 61 is disposed at an angle of 45° with respect to the optical axis ax3 of the reflected blue light RB emitted from the first optical element 31. The second mirror 62 is disposed opposite the first mirror 61 on the +Y side of the first mirror 61 and on the +X side of the first optical system 30. The second mirror 62 is disposed alongside the first optical system 30 on the illumination optical axis AX.

[0054] The first mirror 61 is configured as a mirror that reflects the blue reflected light RB. The first mirror 61 reflects the blue reflected light RB toward the +Y side. The blue reflected light RB reflected by the first mirror 61 is incident on the second mirror 62. The second mirror 62 is configured as a dichroic mirror that has the optical property of reflecting the blue reflected light RB, which is light in a first wavelength band, and transmitting the fluorescence Y, which is light in a second wavelength band.

[0055] By being reflected by the first mirror 61 and the second mirror 62, the optical path of the reflected blue light RB is shifted to the -Y side and approaches the illumination optical axis AX before and after passing through the optical path adjustment optical system 60. Because the fluorescence Y passes through the second mirror 62, the optical path of the fluorescence Y does not change before and after passing through the optical path adjustment optical system 60.

[0056] The optical path adjustment optical system 60 brings the optical path of the blue reflected light RB reflected by the blue reflecting film 311 of the first optical element 31 closer to the optical path (illumination optical axis AX) of the fluorescence Y reflected by the dichroic film 32a of the second optical element 32. Therefore, the optical path adjustment optical system 60 can make the optical paths of the blue reflected light RB and the fluorescence Y at least partially overlap each other. With this configuration, overlapping the optical paths of the blue reflected light RB and the fluorescence Y can suppress color unevenness of the illumination light WL.

[0057] As described above, in the light source device 2 of this embodiment, the optical path adjustment optical system 60 generates white illumination light WL by guiding the blue reflected light RB to the optical path of the fluorescence Y, and causes the white illumination light WL to enter the uniform illumination optical system 70. The uniform illumination optical system 70 is disposed along the illumination optical axis AX of the light source device 2. The uniform illumination optical system 70 has a first lens array 71, a second lens array 72, a polarization conversion element 73, and a superimposing lens 74.

[0058] The first lens array 71 has a plurality of first lenses 71a for dividing the illumination light WL incident from the optical path adjustment optical system 60 into a plurality of partial light beams. The plurality of first lenses 71a are arranged in a matrix in a plane perpendicular to the illumination optical axis AX.

[0059] The second lens array 72 has a plurality of second lenses 72a corresponding to the plurality of first lenses 71a of the first lens array 71. The plurality of second lenses 72a are arranged in a matrix in a plane perpendicular to the illumination optical axis AX. The second lens array 72, together with the superimposing lens 74, forms images of the first lenses 71a of the first lens array 71 near the image forming areas of the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B, respectively.

[0060] The polarization conversion element 73 converts the light emitted from the second lens array 72 into one type of linearly polarized light. The polarization conversion element 73 includes, for example, a polarization separation film and a phase difference plate (not shown).

[0061] The superimposing lens 74 collects the partial light beams emitted from the polarization conversion element 73 and superimposes them near the image forming areas of the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B. The uniform illumination optical system 70 may also include a rod lens that uniforms the illuminance distribution of light.

[0062] As described above, the light source device 2 of this embodiment includes a light source 20 that emits blue light K1 in a blue wavelength band, a first optical system 30 onto which the blue light K1 emitted from the light source 20 is incident, a focusing optical system 40 onto which the blue light K1 that has passed through the first optical system 30 is incident, and a wavelength conversion element 50 that converts a portion of the blue light K1 into fluorescence Y in a yellow wavelength band different from the blue wavelength band. The wavelength conversion element 50 includes a wavelength conversion layer 51 including a light exit surface 51a onto which the blue light K1 is incident and from which the fluorescence Y is emitted, and a light separation film 52 provided on the light exit surface 51a that separates the blue light K1 into one portion and another portion. The first optical system 30 includes a first optical element 31 and a second optical element 32. The first optical element 31 includes a blue reflection film 311 that reflects blue reflected light RB, which is the other portion of the blue light K1, and a diffusion layer 312 that transmits and diffuses the blue light K1. The second optical element 32 includes a dichroic film 32a that transmits the blue light K1 and reflects the fluorescent light Y.

[0063] According to the light source device 2 of this embodiment, the blue light K1 emitted from the light source 20 can be separated into excitation light and blue components of illumination light by the light separation film 52 provided on the light emission surface 51a of the wavelength conversion element 50. This allows the optical path of the fluorescence Y emitted from the wavelength conversion element 50 to partially coincide with the optical path of the blue component reflected by the light separation film 52, thereby making it possible to miniaturize the device configuration.

[0064] Furthermore, in the light source device 2 of this embodiment, the reflected blue light RB is sufficiently diffused by passing through the diffusion layer 312 three times. Therefore, even when highly coherent laser light is used as the blue light K1, the light source device 2 of this embodiment can make interference fringes and speckle noise generated in the illumination light WL less noticeable. Therefore, the light source device 2 of this embodiment can generate illumination light WL in which interference fringes and speckle noise are suppressed.

[0065] The uniform illumination optical system 70 in the light source device 2 of this embodiment is not an essential component, and it is possible to omit the uniform illumination optical system 70 depending on the illuminance distribution required for the illumination light WL.

[0066] The projector 1 of this embodiment includes the light source device 2, and therefore can be a compact projector that displays high-quality color images with reduced interference fringes and speckle noise.

[0067] (Variation) Next, a modified example of the light source device will be described with reference to the drawings. The basic configuration of this modified example is the same as that of the first embodiment, but the configuration of the light path adjusting element is different from that of the first embodiment. Therefore, the configuration of the light path adjusting element will be mainly described below, and components common to those in the drawings used in the above embodiment will be assigned the same reference numerals and will not be described again.

[0068] FIG. 3 is a schematic diagram showing the configuration of a light source device 2A according to a modified example. As shown in FIG. 3, the light source device 2A of this modification includes a light source 20, a first optical system 30, a focusing optical system 40, a wavelength conversion element 50, an optical path adjustment optical system 160, and a uniform illumination optical system .

[0069] The optical path adjustment optical system 160 of this modified example further includes a condenser lens 63 in addition to the first mirror 61 and the second mirror 62. The condenser lens 63 is provided on the optical path of the blue reflected light RB and condenses the blue reflected light RB. In this modified example, the condenser lens 63 is a convex lens provided to face the first optical element 31. The condenser lens 63 condenses the blue reflected light RB that is emitted in a spread state due to being diffused from the first optical element 31, thereby reducing the beam width of the blue reflected light RB.

[0070] The light source device 2A of this modification includes the optical path adjustment optical system 160 including the condenser lens 63, which suppresses the spread of the reflected blue light RB and allows the reflected blue light RB to be efficiently incident on the first mirror 61 and the second mirror 62. Furthermore, by suppressing the luminous flux width of the reflected blue light RB, it is possible to suppress an increase in the size of the first mirror 61 and the second mirror 62. Therefore, according to the light source device 2A of this modified example, it is possible to provide a light source device with high light utilization efficiency that can efficiently utilize the reflected blue light RB as illumination light WL.

[0071] (Second embodiment) Next, a light source device according to a second embodiment of the present invention will be described. The basic configuration of the second embodiment is the same as that of the first embodiment, but the configuration of the first optical system and its periphery differs from that of the first embodiment. Therefore, the following mainly describes the configuration of the first optical system and its periphery, and components common to those in the drawings used in the above embodiments are given the same reference numerals and will not be described again.

[0072] FIG. 4 is a schematic diagram showing the configuration of a light source device 102 according to the second embodiment. As shown in FIG. 4, the light source device 102 of this embodiment includes a light source 20, a first optical system 230, a focusing optical system 40, a wavelength conversion element 50, a uniform illumination optical system 70, and a retardation plate 80.

[0073] In the light source device 102 of this embodiment, the light source 20, the first optical system 230, the retardation plate 80, the condensing optical system 40, and the wavelength conversion element 50 are arranged along the optical axis ax1 of the light source 20. In addition, the first optical system 230 and the optical path adjustment optical system 60 are arranged in the X-axis direction along the illumination optical axis AX.

[0074] The first optical system 230 includes a first optical element 231 and a second optical element 232. In this embodiment, the first optical element 231 and the second optical element 232 are bonded together, for example, with an optical adhesive. This makes it easy to align the first optical element 231 and the second optical element 232.

[0075] The first optical element 231 transmits the blue light K1 emitted from the light source 20. The first optical element 231 has a light-transmitting substrate 430, a polarization separation film 431, and a diffusion layer 432. The polarization separation film 431 of this embodiment corresponds to an example of the "second reflective film" of the present invention.

[0076] The translucent substrate 430 is made of a translucent substrate such as glass or plastic, and has a first surface 430a onto which the blue light K1 emitted from the light source 20 is incident, and a second surface 430b opposite to the first surface 430a.

[0077] The polarization separation film 431 is disposed on the first surface 430a of the light-transmitting substrate 430. The polarization separation film 431 has a polarization separation function of separating the blue light K1 into a P-polarized component (first polarization component) and an S-polarized component (second polarization component) relative to the polarization separation film 431. Specifically, the polarization separation film 431 transmits the P-polarized component of the blue light K1 and reflects the S-polarized component of the blue light K1 and the S-polarized component of reflected blue light RB, which will be described later.

[0078] In this embodiment, the polarization direction of the blue light K1 emitted by the light source 20 coincides with the polarization direction of the P-polarized component that passes through the polarization split film 431. Therefore, the blue light K1 emitted from the light source 20 passes through the polarization separation film 431, and then through the light-transmitting substrate 430 and the diffusion layer 432. That is, the blue light K1 passes through the first optical element 231.

[0079] The blue light K1 that has passed through the first optical element 231 is diffused by passing through the diffusion layer 432 and then enters the second optical element 232. The second optical element 232 includes a dichroic film 232a that transmits the blue light K1 in the blue wavelength band regardless of the polarization direction and reflects the fluorescence Y in the yellow wavelength band regardless of the polarization direction. The second optical element 232 is attached to the diffusion layer 432 of the first optical element 231.

[0080] In this way, the blue light K1 emitted from the light source 20 passes through the first optical system 230 including the first optical element 231 and the second optical element 232. The blue light K1 that has passed through the first optical system 230 enters the retardation plate 80.

[0081] The retardation plate 80 is composed of a quarter-wave plate (λ / 4 plate) arranged in the optical path between the first optical system 230 and the wavelength conversion element 50. Therefore, the blue light K1, which is a P-polarized component emitted from the light source 20, passes through the retardation plate 80 and is converted into, for example, right-handed circularly polarized blue light K11, and then enters the focusing optical system 40.

[0082] The blue light K11 is collected by the collecting optical system 40 and enters the wavelength conversion element 50. A part of the blue light K11 is converted into fluorescent light Y by the wavelength conversion element 50, and another part of the blue light K1 is reflected as blue reflected light RB1.

[0083] In this embodiment, the optical axis ax1 of the blue light K11 incident on the focusing optical system 40 coincides with the central axis 40C of the focusing optical system 40. Therefore, in this embodiment, in the wavelength conversion element 50, the chief ray of the blue reflected light RB1 reflected by the light separating film 52 returns to the light source 20 side through the same path as the chief ray of the blue light K1.

[0084] As described above, the blue light K11 is clockwise circularly polarized light before being reflected by the light separating film 52, and therefore becomes counterclockwise circularly polarized light when reflected by the light separating film 52. In other words, the blue light K11 is emitted from the wavelength conversion element 50 as blue reflected light RB1, which is counterclockwise circularly polarized light, and is then substantially collimated by the focusing optical system 40 and enters the retardation plate 80. The blue reflected light RB1 is converted into blue reflected light RB2, which is an S-polarized component, by passing through the retardation plate 80, and the chief ray of the blue reflected light RB2 returns to the light source 20 side along the same path as the chief ray of the fluorescence Y. In this manner, in this embodiment, the reflected blue light RB1 that has passed through the phase difference plate 80 becomes reflected blue light RB2 that is an S-polarized component of light that is different from the P-polarized component emitted from the light source 20.

[0085] The reflected blue light RB2 passes through the second optical element 232 and enters the first optical element 231. The reflected blue light RB2 passes through the diffusion layer 432 and the light-transmitting substrate 430 of the first optical element 231 and enters the polarization separation film 431. As described above, the reflected blue light RB2 is an S-polarized component, so it is reflected by the polarization separation film 431, passes through the light-transmitting substrate 430 and the diffusion layer 432 again, exits the first optical element 231, and is also transmitted through the second optical element 232.

[0086] In this embodiment, the reflected blue light RB2 is sufficiently diffused by passing through the diffusion layer 432 three times and is then emitted as the illumination light WL. Therefore, even in this embodiment, even when highly coherent laser light is used as the blue light K1, interference fringes and speckle noise generated in the illumination light WL can be made less noticeable. Therefore, the light source device 102 of this embodiment can also generate illumination light WL with reduced interference fringes and speckle noise.

[0087] On the other hand, the fluorescence Y emitted from the wavelength conversion element 50 is substantially collimated by the focusing optical system 40 and enters the retardation plate 80. Because the fluorescence Y is unpolarized, it passes through the retardation plate 80 without changing its polarization state, enters the first optical system 230, and is reflected by the second optical element 232 to the +X side.

[0088] The light source device 102 of this embodiment can also emit illumination light WL containing blue reflected light RB2 and fluorescence Y in the X-axis direction from the first optical system 230. In this embodiment, the chief ray of the blue reflected light RB2 and the chief ray of the fluorescence Y coincide with each other, so the overlap width of the blue reflected light RB2 and the fluorescence Y can be increased without using the optical path adjustment optical system 60. Therefore, the light source device 102 of this embodiment can emit illumination light WL with reduced color unevenness while reducing the size of the device configuration.

[0089] Furthermore, in the light source device 102 of this embodiment, the polarization direction of the blue light K1 when emitted from the light source 20 and incident on the first optical element 231 is different from the polarization direction of the blue reflected light RB2 when emitted from the wavelength conversion element 50 and incident on the first optical element 231. For this reason, the polarization separation film 431 of the first optical element 231 does not need to have different regions through which the blue light K1 passes and the blue reflected light RB2 passes. Therefore, in the light source device 102 of this embodiment, it is not necessary to shift the optical paths of the blue light K1 and the blue reflected light RB2 in the X-axis direction along which the illumination light WL is extracted, and therefore there are no restrictions on the layout of each component, which increases design freedom and enables the device configuration to be made more compact.

[0090] Here, the larger the luminous flux width of the reflected blue light RB2, the smaller the difference in luminous flux width between the reflected blue light RB2 and the fluorescent light Y, making it possible to reduce color unevenness of the illumination light WL. In order to increase the luminous flux width of the reflected blue light RB2, it is desirable to diffuse the reflected blue light RB2 somewhere in the optical path other than the diffusion layer 432. The wavelength conversion element 50, for example, can be considered as a position where the reflected blue light RB2 is scattered.

[0091] The following describes a configuration in which the blue reflected light RB2 is scattered in the wavelength conversion element 50. Fig. 5 is a diagram showing the configuration of a modified wavelength conversion element. 5, the wavelength conversion element 150 of this modification includes a wavelength conversion layer 51, a light separation film 52, a substrate 53, and a reflecting member 54. In the wavelength conversion element 150 of this modification, the light exit surface 51a of the wavelength conversion layer 51 includes a scattering structure 55 that scatters incident light. The scattering structure 55 is configured by concaves and convexes formed by roughening the surface of the light exit surface 51a by, for example, sandblasting. The light separation film 52 is provided on the light exit surface 51a so as to cover the scattering structure 55.

[0092] According to the wavelength conversion element 150 having the configuration shown in FIG. 5, when another part of the blue light K1 incident from the light source 20 is reflected as blue reflected light RB1, it can be reflected while being diffused by the scattering structure 55. According to this configuration, the reflected blue light RB2 contained in the illumination light WL can be diffused four times, including diffusion by the scattering structure 55 of the wavelength conversion element 150. Therefore, the reflected blue light RB2 can be sufficiently diffused, making interference fringes and speckle noise occurring in the illumination light WL less noticeable and further reducing color unevenness in the illumination light WL.

[0093] Furthermore, in the light source device 102 of the present embodiment, the optical axis ax1 of the blue light K11 and the central axis 40C of the focusing optical system 40 are aligned with each other, but as in the first embodiment, the optical axis ax1 of the blue light K11 and the central axis 40C of the focusing optical system 40 may be offset from each other. In this case, the optical path of the blue reflected light RB2 may be brought closer to the optical path of the fluorescence Y by combining the optical path adjustment optical system 60.

[0094] The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. In addition, the specific descriptions of the shape, number, arrangement, material, etc. of each component of the light source device and the projector are not limited to the above-described embodiments and can be changed as appropriate.

[0095] A summary of this disclosure is provided below.

[0096] (Appendix 1) a light source that emits a first light having a first wavelength band; a first optical system into which the first light emitted from the light source is incident; a focusing optical system onto which the first light that has passed through the first optical system is incident; a wavelength conversion element that converts a part of the first light into second light of a second wavelength band different from the first wavelength band, the wavelength conversion element includes a wavelength conversion layer including a light exit surface through which the first light is incident and from which the second light exits, and a first reflection film provided on the light exit surface to separate the first light into the part and another part, the first optical system includes a first optical element and a second optical element, the first optical element includes a second reflecting film that reflects the other part of the first light and a diffusion layer that transmits and diffuses the first light, the second optical element includes a third reflective film that transmits the first light and reflects the second light; Light source device.

[0097] According to the light source device having this configuration, the first reflective film provided on the light exit surface of the wavelength conversion element can separate the first light emitted from the light source into a portion of light for wavelength conversion and another portion of light for illumination, thereby making it possible to downsize the device configuration by partially matching the optical path of the second light emitted from the wavelength conversion element and the optical path of the illumination light reflected by the first reflective film. Furthermore, because the remaining part of the light used for illumination is sufficiently diffused by passing through the diffusion layer three times, interference fringes and speckle noise generated in the illumination light can be made less noticeable, even when, for example, highly coherent laser light is used as the first light, thereby making it possible to provide a light source device that generates illumination light with reduced interference fringes and speckle noise.

[0098] (Appendix 2) the first optical element further includes a light-transmitting substrate having a first surface onto which the first light emitted from the light source is incident and a second surface opposite to the first surface, the second reflective film is disposed on the first surface of the light-transmitting substrate, the diffusion layer is disposed on the second surface of the light-transmitting substrate. 10. The light source device of claim 1.

[0099] According to this configuration, the configuration of the first optical element can be easily provided by providing the second reflective film and the diffusion layer on both sides of the light-transmitting substrate.

[0100] (Appendix 3) the first light emitted from the light source and another part of the first light are incident on different regions of the first optical element, the first surface of the light-transmitting substrate includes a first region in which the second reflective film is disposed and a second region that transmits the first light incident from the light source; the second surface of the light-transmitting substrate includes a third region in which the diffusion layer is disposed and which faces the second region of the first surface, and a fourth region in which the diffusion layer is disposed and which faces the first region of the first surface, and through which another part of the first light passes; 10. The light source device according to claim 2.

[0101] According to this configuration, another portion of the first light reflected by the second reflective film passes through the first and fourth regions of the light-transmitting substrate and enters the diffusion layer. Because another portion of the first light passes through the diffusion layer 312 twice in the first optical element, another portion of the first light emitted from the light source passes through the diffusion layer three times. Therefore, even when laser light is used as the first light, interference fringes and speckle noise can be made less noticeable.

[0102] (Appendix 4) an optical path of the second light reflected by the third reflective film of the second optical element overlaps with at least a part of an optical path of the other part of the first light reflected by the second reflective film of the first optical element; 4. A light source device according to any one of claims 1 to 3.

[0103] According to this configuration, the other part of the first light and at least part of the optical path of the second light overlap each other, thereby making it possible to suppress color unevenness in the illumination light.

[0104] (Appendix 5) further comprising an optical path adjusting optical system that brings an optical path of another part of the first light reflected by the second reflecting film closer to an optical path of the second light reflected by the third reflecting film; 5. The light source device according to claim 4.

[0105] According to this configuration, the optical path adjusting optical system can easily realize a state in which the other part of the first light and at least part of the optical path of the second light overlap each other.

[0106] (Appendix 6) the optical path adjustment optical system is provided on an optical path of the other part of the first light and includes a condenser lens that condenses the other part of the first light. 6. The light source device according to claim 5.

[0107] According to this configuration, since the optical path adjustment optical system including the condenser lens is provided, the other part of the first light can be efficiently incident on the subsequent optical system by suppressing the spread of the other part of the first light, and therefore, a light source device with high light utilization efficiency can be provided, which can efficiently use the other part of the first light as illumination light.

[0108] (Appendix 7) the focusing optical system is a lens having a positive power, an optical axis of the first light incident on the focusing optical system is shifted from a central axis of the focusing optical system; 7. A light source device according to any one of claims 1 to 6.

[0109] With this configuration, the first light is incident obliquely onto the center of the wavelength conversion element, and therefore another part of the first light is reflected by the first reflecting film and can be made to enter the focusing optical system via an optical path different from the optical path of the first light.

[0110] (Appendix 8) further comprising a retardation plate disposed between the first optical system and the wavelength conversion element; the first light emitted from the light source is light of a first polarization component, the other part of the first light that has passed through the phase difference plate is light of a second polarization component different from the first polarization component, the second reflective film transmits the light of the first polarization component and reflects the light of the second polarization component; 7. A light source device according to any one of claims 1 to 6.

[0111] With this configuration, the second reflective film can separate the first light based on its polarization components, eliminating the need to shift the optical path of the first light emitted from the light source from the optical path of the other part of the first light. This eliminates constraints on the layout of each component, increasing design freedom and enabling a more compact device configuration.

[0112] (Appendix 9) the light incident surface of the wavelength conversion layer includes a scattering structure that scatters incident light; 9. The light source device according to claim 8.

[0113] According to this configuration, the other part of the first light contained in the illumination light is diffused four times, including the diffusion by the scattering structure of the wavelength conversion element, so that the other part of the first light can be sufficiently diffused, thereby making interference fringes and speckle noise occurring in the illumination light less noticeable and further reducing color unevenness in the illumination light.

[0114] (Appendix 10) the focusing optical system is a lens having a positive power, an optical axis of the first light incident on the focusing optical system coincides with a central axis of the focusing optical system; 10. The light source device according to claim 8 or 9.

[0115] According to this configuration, the chief ray of the other part of the first light reflected by the second reflective film returns to the light source side along the same path as the chief ray of the first light incident from the light source. Also, the chief ray of the second light emitted from the wavelength conversion element returns to the light source side along the same path as the chief ray of the other part of the first light. Therefore, the overlap width between the other part of the first light and the second light is increased, and it is possible to emit illumination light with reduced color unevenness while miniaturizing the configuration of the light source device.

[0116] (Appendix 11) the wavelength conversion element further includes a substrate supporting the wavelength conversion layer on a side opposite to the light exit surface, and a reflecting member provided between the substrate and the wavelength conversion layer and reflecting the second light. 11. A light source device according to any one of claims 1 to 10.

[0117] According to this configuration, the second light can be reflected by the reflecting member toward the wavelength conversion layer, and therefore the second light can be extracted efficiently from the wavelength conversion element.

[0118] (Appendix 12) a light source device according to any one of Supplementary Note 1 to Supplementary Note 11; a light modulation device that modulates light incident from the light source device; a projection optical device that projects the light modulated by the light modulation device; Equipped with projector.

[0119] According to a projector having this configuration, since it is equipped with the light source device, it is possible to realize a small projector that displays high-quality color images with reduced interference fringes and speckle noise. [Explanation of symbols]

[0120] 1...Projector, 2, 2A, 102...Light source device, 4B, 4G, 4R...Light modulation device, 6...Projection optical device, 20...Light source, 30, 230...First optical system, 31, 231...First optical element, 31A...First region, 31B...Second region, 31C...Third region, 31D...Fourth region, 32, 232...Second optical element, 32a...Dichroic film (third reflective film), 40...Condensing optical system, 40C...Central axis, 63...Condensing lens, 50, 150...Wavelength conversion Element, 51... Wavelength conversion layer, 51a... Light exit surface, 52... Light separation film (first reflective film), 53... Substrate, 54... Reflective member, 55... Scattering structure, 60,160... Optical path adjustment system, 80... Retardation plate, 310,430... Transparent substrate , 310a, 430a...first surface, 310b,430b...second surface, 311...blue reflective film (second reflective film), 312,432...diffusion layer, ax1, ax2, ax3...optical axis, K1...blue light (first light), Y...fluorescence (second light).

Claims

1. a light source that emits first light having a first wavelength band; a first optical system onto which the first light emitted from the light source is incident; a focusing optical system onto which the first light that has passed through the first optical system is incident; a wavelength conversion element that converts a part of the first light into second light of a second wavelength band different from the first wavelength band, the wavelength conversion element includes a wavelength conversion layer including a light exit surface through which the first light is incident and from which the second light exits, and a first reflection film provided on the light exit surface to separate the first light into the part and another part, the first optical system includes a first optical element and a second optical element, the first optical element includes a second reflecting film that reflects the other part of the first light and a diffusion layer that transmits and diffuses the first light, the second optical element includes a third reflective film that transmits the first light and reflects the second light; Light source device.

2. the first optical element further includes a light-transmitting substrate having a first surface onto which the first light emitted from the light source is incident and a second surface opposite to the first surface, the second reflective film is disposed on the first surface of the light-transmitting substrate, the diffusion layer is disposed on the second surface of the light-transmitting substrate; The light source device according to claim 1 .

3. the first light emitted from the light source and another portion of the first light are incident on different regions of the first optical element, the first surface of the light-transmitting substrate includes a first region in which the second reflective film is disposed and a second region that transmits the first light incident from the light source; the second surface of the light-transmitting substrate includes a third region in which the diffusion layer is disposed and which faces the second region of the first surface, and a fourth region in which the diffusion layer is disposed and which faces the first region of the first surface, and through which another part of the first light passes; The light source device according to claim 2 .

4. an optical path of the second light reflected by the third reflective film of the second optical element overlaps with at least a part of an optical path of the other part of the first light reflected by the second reflective film of the first optical element; The light source device according to claim 1 .

5. further comprising an optical path adjusting optical system that brings an optical path of another part of the first light reflected by the second reflecting film closer to an optical path of the second light reflected by the third reflecting film; The light source device according to claim 4 .

6. the optical path adjustment optical system is provided on an optical path of the other part of the first light and includes a condenser lens that condenses the other part of the first light. The light source device according to claim 5 .

7. the focusing optical system is a lens having a positive power, an optical axis of the first light incident on the focusing optical system is shifted from a central axis of the focusing optical system; The light source device according to claim 1 .

8. further comprising a retardation plate disposed between the first optical system and the wavelength conversion element; the first light emitted from the light source is light of a first polarization component, the other part of the first light that has passed through the phase difference plate is light of a second polarization component different from the first polarization component, the second reflective film transmits the light of the first polarization component and reflects the light of the second polarization component; The light source device according to claim 1 .

9. the light exit surface of the wavelength conversion layer includes a scattering structure that scatters incident light; The light source device according to claim 7 .

10. the focusing optical system is a lens having a positive power, an optical axis of the first light incident on the focusing optical system coincides with a central axis of the focusing optical system; 10. The light source device according to claim 8 or 9.

11. the wavelength conversion element further includes a substrate supporting the wavelength conversion layer on a side opposite to the light exit surface, and a reflecting member provided between the substrate and the wavelength conversion layer and reflecting the second light. The light source device according to any one of claims 1 to 9.

12. The light source device according to any one of claims 1 to 9; a light modulation device that modulates light incident from the light source device; a projection optical device that projects the light modulated by the light modulation device; Equipped with projector.

Images