JP2022135481A - Light source device and projector - Google Patents

Abstract

To provide a light source device and a projector that can reduce etendue while preventing an increase in light density of excitation light.SOLUTION: The light source device of the present invention comprises: a light source that emits light in a first wavelength range; a first optical element that transmits part of the light in the first wavelength range and reflects the other part of the light; a wavelength conversion element that converts the wavelength of the light in the first wavelength range to emit light in a second wavelength range; a diffusion element; and a second optical element that synthesizes the light in the first wavelength range and the light in the second wavelength range. The wavelength conversion element has a wavelength conversion layer, a substrate, a first optical member that transmits the light in the first wavelength range and reflects the light in the second wavelength range, a second optical member that reflects at least the light in the second wavelength range, a third optical member that reflects at least the light in the second wavelength range, and an opening. The area of a light incident surface of the wavelength conversion layer is larger than the area of a light incident region on the light incident surface on which the light in the first wavelength range is incident. The area of a light incident surface region is larger than the area of the opening. The light in the second wavelength range is emitted from the opening.SELECTED DRAWING: Figure 3

Description

The present invention relates to a light source device and a projector.

2. Description of the Related Art As a light source device used in a projector, there is a light source device that illuminates an object to be illuminated such as a liquid crystal panel with high luminance by reducing etendue (see, for example, Patent Documents 1 and 2 below). In recent years, as a light source device used in a projector, there is also a light source device that uses fluorescence generated by exciting a phosphor as illumination light.

JP 2008-026853 A JP 2008-112114 A

In general, the fluorescence etendue can be reduced by reducing the incident area of the excitation light on the phosphor. However, when the incident area of the excitation light is reduced, the optical density of the excitation light is increased, resulting in a problem of reduced fluorescence conversion efficiency.
Thus, conventionally, it has been difficult to reduce the etendue while suppressing an increase in the optical density of the excitation light.

In order to solve the above problems, according to one aspect of the present invention, a light source that emits light in a first wavelength band; A first optical element that partially transmits and reflects another part of the light in the first wavelength band, a part of the light in the first wavelength band and the other part of the light in the first wavelength band a wavelength conversion element that converts the wavelength of light in the first wavelength band and emits at least light in a second wavelength band different from the first wavelength band; one of a part of the light and another part of the light in the first wavelength band is incident, a diffusion element for diffusing the light in the first wavelength band; and the second diffusion element emitted from the wavelength conversion element. a second optical element for synthesizing the light in the wavelength band and the light in the first wavelength band emitted from the diffusion element, the wavelength conversion element having a light incident surface, the light incident surface a wavelength conversion layer for converting the wavelength of the light in the first wavelength band incident on to generate light in the second wavelength band; a substrate having a support surface for supporting the wavelength conversion layer; a first optical member having a first optical layer that transmits light and reflects light in the second wavelength band, the first optical member being disposed so as to face the support surface; a second optical member having a second optical layer that reflects light in a wavelength band, the second optical layer being disposed so as to intersect the support surface and the first optical layer; and at least the second wavelength. A third optical layer having a third optical layer for reflecting a band of light, wherein the third optical layer intersects the support surface and the first optical layer and is arranged to face the second optical layer and an opening formed by the substrate, the first optical member, the second optical member and the third optical member, wherein the area of the light incident surface of the wavelength conversion layer is equal to the light The area of the light incident surface is larger than the area of the light incident surface into which the light of the first wavelength band is incident on the incident surface, the area of the light incident surface region is larger than the area of the opening, and the light of the second wavelength band is the A light source device that emits light from an opening is provided.

According to a second aspect of the present invention, the light source device according to the first aspect of the present invention, a light modulation device that modulates the light from the light source device according to image information, and the light modulated by the light modulation device A projection optical device for projecting is provided.

1 is a diagram showing a schematic configuration of a projector according to a first embodiment; FIG. It is a schematic block diagram of a light source device. It is a perspective view which shows schematic structure of a wavelength conversion element. It is the front view which looked at the wavelength conversion element from the +Y side. FIG. 3 is a cross-sectional view of a wavelength conversion element; It is a schematic block diagram of the light source device of 2nd Embodiment. It is a schematic block diagram of the light source device of 3rd Embodiment. It is a schematic block diagram of the light source device of 4th Embodiment. It is a schematic block diagram of the light source device of 5th Embodiment. FIG. 10 is a cross-sectional view showing the configuration of a first optical element according to a first modified example; FIG. 10 is a cross-sectional view showing the configuration of a first optical element according to a second modified example; FIG. 11 is a plan view showing the configuration of a first optical element according to a second modified example; FIG. 11 is a plan view showing the configuration of a first optical element according to a third modified example;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In addition, in the drawings used in the following explanation, in order to make the features easier to understand, the characteristic portions may be enlarged for convenience, and the dimensional ratios of each component may not necessarily be the same as the actual ones. do not have.

(First embodiment)
An example of the projector according to this embodiment will be described.
FIG. 1 is a diagram showing a schematic configuration of a projector according to this embodiment.
As shown in FIG. 1, the projector 1 of this embodiment is a projection type image display device that displays a color image on a screen SCR. The projector 1 includes a color separation optical system 3 , an optical modulator 4 R, an optical modulator 4 G, an optical modulator 4 B, a synthesizing optical system 5 , a projection optical device 6 and a light source device 2 .

The color separation optical system 3 separates the white illumination light WL from the light source device 2 into red light LR, green light LG, and blue light LB. The color separation optical system 3 includes a first dichroic mirror 7a and a second dichroic mirror 7b, a first total reflection mirror 8a, a second total reflection mirror 8b and a third total reflection mirror 8c, and a first It has a relay lens 9a and a second relay lens 9b.

The first dichroic mirror 7a separates the illumination light WL from the light source device 2 into red light LR and other lights, green light LG and blue light LB. The first dichroic mirror 7a transmits the separated red light LR and reflects other light. The second dichroic mirror 7b reflects the green light LG and transmits the blue light LB.

The first total reflection mirror 8a reflects the red light LR toward the light modulator 4R. The second total reflection mirror 8b and the third total reflection mirror 8c guide the blue light LB to the light modulator 4B. The green light LG is reflected from the second dichroic mirror 7b toward the light modulator 4G.

The first relay lens 9a is arranged behind the second dichroic mirror 7b in the optical path of the blue light LB. The second relay lens 9b is arranged behind the second total reflection mirror 8b in the optical path of the blue light LB.

The light modulator 4R modulates the red light LR according to image information to form image light corresponding to the red light LR. The light modulator 4G modulates the green light LG according to image information to form image light corresponding to the green light LG. The light modulation device 4B modulates the blue light LB according to image information to form image light corresponding to the blue light LB.

Transmissive liquid crystal panels, for example, are used for the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B. Further, polarizing plates (not shown) are arranged on the entrance side and the exit side of the liquid crystal panel, respectively, so as to pass only linearly polarized light in a specific direction.

A field lens 10R, a field lens 10G, and a field lens 10B are arranged on the incident sides of the light modulator 4R, the light modulator 4G, and the light modulator 4B, respectively. The field lens 10R, the field lens 10G, and the field lens 10B collimate the chief rays of the red light LR, the green light LG, and the blue light LB incident on the light modulator 4R, the light modulator 4G, and the light modulator 4B, respectively. do.

The synthesizing optical system 5 generates image light corresponding to the red light LR, the green light LG, and the blue light LB by receiving the image light emitted from the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B. The combined image light is emitted toward the projection optical device 6 . A cross dichroic prism, for example, is used for the synthesizing optical system 5 .

The projection optical device 6 is composed of a plurality of lenses. The projection optical device 6 magnifies and projects the image light synthesized by the synthesizing optical system 5 toward the screen SCR. An image is thereby displayed on the screen SCR.

(light source device)
FIG. 2 is a schematic configuration diagram of the light source device 2. As shown in FIG.
In the following drawings including FIG. 2, each configuration of the light source device 2 will be described using an XYZ coordinate system as necessary. The X-axis is parallel to the optical axis ax3 along the principal ray of light emitted from the light source 22 and the optical axis ax5 along the principal ray of light emitted from the diffusion element 31 . The Y-axis is orthogonal to the optical axis ax3 and parallel to the optical axis ax4 along the principal ray of the light reflected by the first optical element 29 and the illumination optical axis ax1. The Z-axis is an axis perpendicular to the X-axis and the Y-axis. That is, the optical axis ax3, the optical axis ax4, the optical axis ax5, and the illumination optical axis ax1 are located in the same plane, the optical axes ax3 and the optical axis ax5 are orthogonal to the illumination optical axis ax1, and the optical axis ax4 is the illumination optical axis. It is parallel to ax1 and orthogonal to optical axis ax3 and optical axis ax5. That is, the optical axis ax3, the optical axis ax4, the optical axis ax5, and the illumination optical axis ax1 are positioned on a virtual plane along the XY plane.

As shown in FIG. 2, the light source device 2 includes a light source 22, a first homogenizer optical system 23, a first condensing optical system 24, a wavelength conversion element 25, a first pickup optical system 26, and a second homogenizer. An optical system 27, a second condensing optical system 28, a first optical element 29, a second optical element 30, a diffusion element 31, a second pickup optical system 32, an integrator optical system 35, and a polarization conversion element. 36 and superimposing lens 37, and these members are arranged on a virtual plane along the XY plane. The light source device 2 of this embodiment emits white illumination light WL.

Light source 22 includes light emitting unit 201 and collimator lens 202 . The light emitting section 201 is composed of a semiconductor laser. The light emitting unit 201 emits a light beam E composed of a light beam having a peak wavelength of 445 nm, for example. A semiconductor laser that emits a light beam E having a wavelength other than 445 nm can also be used as the light emitting unit 201 . For example, the light emitting unit 201 may emit a light beam E that is a light beam having a peak wavelength of 460 nm.

The collimating lens 202 is arranged corresponding to the light emitting section 201 . The collimating lens 202 converts the light E emitted from the light emitting section 201 into parallel light. Note that the number of light emitting units 201 and collimating lenses 202 is not particularly limited.
In this manner, the light source 22 emits the excitation light (light in the first wavelength band) EL as a parallel light beam having a blue wavelength band (first wavelength band).

In the light source device 2 of this embodiment, the light source 22, the first optical element 29, the first homogenizer optical system 23, the first condensing optical system 24, and the wavelength conversion element 25 are arranged on the optical axis ax3 of the light source 22. and are placed.
In the light source device 2 of this embodiment, the first optical element 29, the second homogenizer optical system 27, the second condensing optical system 28, and the diffusion element 31 are arranged on the optical axis ax4.
In the light source device 2 of this embodiment, the diffusion element 31, the second pickup optical system 32, and the second optical element 30 are arranged on the optical axis ax5.
In the light source device 2 of this embodiment, the wavelength conversion element 25, the first pickup optical system 26, the second optical element 30, the integrator optical system 35, and the polarization conversion element 36 are superimposed on the illumination optical axis ax1. A lens 37 is arranged.

The excitation light EL emitted from the light source 22 enters the first optical element 29 . The first optical element 29 is arranged to form an angle of 45° with respect to the optical axis ax3 and the optical axis ax4.
The first optical element 29 is an element that transmits part of the excitation light EL and reflects another part of the excitation light EL. In this embodiment, the first optical element 29 includes a translucent substrate 29a and a half mirror layer 29b. The translucent substrate 29a is a substrate translucent to the excitation light EL. The half mirror layer 29b is composed of, for example, a dielectric multilayer film formed on the translucent substrate 29a. The half-mirror layer 29b of the present embodiment is not limited to the case where the ratio of the amount of transmitted light and the amount of reflected light in the excitation light EL is equal (50:50), and the excitation light EL is not completely reflected or transmitted, and is at least partially Any layer may be used as long as it transmits or reflects a portion and reflects or transmits another portion.

The excitation light EL reflected by the first optical element 29 travels along the optical axis ax4 and enters the second homogenizer optical system 27 . The excitation light EL transmitted through the first optical element 29 travels along the optical axis ax3 and enters the first homogenizer optical system 23 . Hereinafter, part of the excitation light EL transmitted through the first optical element 29 and separated in the X direction (first direction) will be referred to as excitation light EL1, and reflected by the first optical element 29 in the Y direction (second direction). ) Another portion of the separated excitation light EL is referred to as blue light EL2.

The second homogenizer optical system 27 on which the blue light (part of the light in the first wavelength band) EL2 is incident is composed of, for example, a lens array 27a and a lens array 27b. Lens array 27a includes a plurality of lenslets 27am, and lens array 27b includes a plurality of lenslets 27bm.
The lens array 27a splits the blue light EL2 into a plurality of light beamlets. The small lenses 27am of the lens array 27a image the small ray bundles onto the corresponding small lenses 27bm of the lens array 27b. The lens array 27b superimposes the image of each small lens 27am of the lens array 27a on the diffusing element 31 together with the second condensing optical system 28, which will be described later. The second condensing optical system 28 cooperates with the second homogenizer optical system 27 to homogenize the illuminance distribution of the blue light EL2 incident on the diffusion element 31 and suppress the light density of the blue light EL2 on the diffusion element 31. do. The second condensing optical system 28 is composed of a single lens or a plurality of lenses.

The diffusion element 31 diffuses the blue light EL2 and emits it toward the second optical element 30 . Diffusion element 31 includes a diffuse reflector 31a and a motor 31b for rotating diffuse reflector 31a. The diffuse reflection plate 31 a diffuses and reflects the blue light EL<b>2 toward the second optical element 30 . It is desirable that the diffuse reflection plate 31a be formed so as to diffuse the blue light EL2 so that the diffusion angle is approximately the same as that of the fluorescence YL emitted from the wavelength conversion element 25. FIG. As a result, it is possible to reduce the color unevenness of the illumination light WL obtained by synthesizing the diffused blue light EL2 and the fluorescent light YL.

The rotation axis O of the motor 31b is arranged to form an angle of 45° with the optical axes ax4 and ax5. As a result, the diffusion element 31 allows the light incident surface of the diffuse reflection plate 31a to rotate within a plane forming an angle of 45° with the optical axes ax4 and ax5. The diffusion reflection plate 31a is formed, for example, in a circular shape when viewed from the direction of the rotation axis O, but the shape of the diffusion reflection plate 31a is not limited to a disc. In the case of this embodiment, by rotating the diffuse reflector 31a, the temperature rise of the diffuse reflector 31a can be suppressed, and the reliability of the diffusion element 31 can be improved.

Although the diffusion element 31 of this embodiment is a rotary diffusion element, a stationary diffusion element may be used instead of this configuration. In this case, since the motor 31b becomes unnecessary, the cost of the diffusion element can be reduced.

In this embodiment, the blue light EL2 incident on the diffusing element 31 is reflected in a diffused state. The blue light EL2 diffusely reflected by the diffusion element 31 is hereinafter referred to as diffused blue light BL. In this embodiment, the chief ray of the diffused blue light BL coincides with the optical axis ax5.

In this manner, the diffusion element 31 reflects the blue light EL2 branched from the first optical element 29 in the Y direction and incident thereon to one side (+X side) in the X direction as diffused blue light BL. The diffused blue light BL emitted from the diffusion element 31 enters the second pickup optical system 32 . The diffused blue light BL is incident on the second pickup optical system 32 in a state of being spread to the same luminous flux width as the fluorescent light YL emitted from the wavelength conversion element 25, which will be described later. The second pickup optical system 32 has a function of picking up the diffused blue light BL emitted from the diffusion element 31 and collimating it. The second pickup optical system 32 is composed of a single lens or a plurality of lenses.

The diffused blue light BL collimated by the second pickup optical system 32 enters the second optical element 30 . The second optical element 30 includes a translucent substrate 30a and a dichroic mirror 30b. The translucent substrate 30a of the present embodiment is a substrate translucent to at least fluorescence YL, which is light in the second wavelength band. The dichroic mirror 30b of the present embodiment transmits fluorescence YL, which is light in the second wavelength band emitted from the wavelength conversion element 25, and diffuse blue light, which is light in the first wavelength band emitted from the diffusion element 31. It has an optical characteristic of reflecting light BL. Therefore, the second optical element 30 reflects the diffused blue light BL toward one side (+Y side) in the Y direction.

On the other hand, the excitation light (other part of the light in the first wavelength band) EL1 that has passed through the first optical element 29 enters the first homogenizer optical system 23 . The first homogenizer optical system 23 is composed of, for example, a lens array 23a and a lens array 23b. Lens array 23a includes a plurality of small lenses 23am, and lens array 23b includes a plurality of small lenses 23bm.

The lens array 23a separates the excitation light EL1 into a plurality of light beamlets. The small lenses 23am of the lens array 23a image the small ray bundles onto the corresponding small lenses 23bm of the lens array 23b. The lens array 23 b superimposes the image of each small lens 23 am of the lens array 23 a on the phosphor layer 251 of the wavelength conversion element 25 together with the first condensing optical system 24 to be described later. The first condensing optical system 24 cooperates with the first homogenizer optical system 23 to homogenize the illuminance distribution of the excitation light EL incident on the phosphor layer 251 of the wavelength conversion element 25 . Note that the first condensing optical system 24 is composed of a single lens or a plurality of lenses.

The wavelength conversion element 25 has a phosphor layer 251 that generates fluorescence YL by being excited by excitation light EL1 that is incident toward the +X side from the light source 22, and a substrate 252 that supports the phosphor layer 251. The wavelength conversion element 25 emits the generated fluorescence YL from the opening 260 toward one side (+Y side) in the Y direction.

FIG. 3 is a perspective view showing a schematic configuration of the wavelength conversion element 25. As shown in FIG. FIG. 4 is a front view of the wavelength conversion element 25 viewed from the +Y side. FIG. 5 is a cross-sectional view of the wavelength conversion element 25. As shown in FIG. Note that FIG. 5 is a cross section along the XY plane.
As shown in FIGS. 3 to 5, the wavelength conversion element 25 of this embodiment includes a phosphor layer (wavelength conversion layer) 251, a substrate 252, a fourth optical layer 253, a first optical member 254, A second optical member 255 and a third optical member 256 are provided. The wavelength conversion element 25 has an opening 260 through which the fluorescence YL generated by the phosphor layer 251 is emitted. The opening 260 is provided on the +Y side of the wavelength conversion element 25 .
The openings 260 of the present embodiment are openings formed at the +Y side end surfaces of the substrate 252, the first optical member 254, the second optical member 255, and the third optical member 256, respectively.

The phosphor layer 251 includes phosphor particles that are excited by the excitation light EL and emit fluorescence (second wavelength band light) YL in a yellow wavelength band (second wavelength band). The phosphor layer 251 generates fluorescence YL by wavelength-converting the excitation light EL.
The phosphor layer 251 is a plate-like phosphor including a front surface (light incident surface) 2511 , a side surface 2512 and a back surface 2513 . The surface 2511 is the surface on which the excitation light EL is incident. Side 2512 is a plane that intersects surface 2511 . Side 2512 may be orthogonal to surface 2511 . Back surface 2513 is the opposite surface of front surface 2511 .

As the phosphor particles, for example, a YAG (yttrium-aluminum-garnet)-based phosphor can be used. The material for forming the phosphor particles may be one kind, or a mixture of particles formed using two or more kinds of materials may be used as the phosphor particles. As the phosphor layer 251, for example, a phosphor layer in which phosphor particles are dispersed in an inorganic binder such as alumina, a phosphor layer in which phosphor particles are sintered without using a binder, or the like may be used. The phosphor layer 251 of this embodiment includes a plurality of pores (scatterers) K. As shown in FIG.

Phosphor layer 251 is supported by substrate 252 . Substrate 252 includes a support surface 2521 that supports phosphor layer 251 . The support surface 2521 is a surface parallel to the YZ plane. The substrate 252 is thermally connected with the phosphor layer 251 . The substrate 252 is, for example, a metal plate such as aluminum or copper having excellent heat dissipation properties. Since the substrate 252 is thermally connected to the phosphor layer 251 , the phosphor layer 251 is cooled by releasing the heat of the phosphor layer 251 .

The phosphor layer 251 is housed in the housing space S in the wavelength conversion element 25 . The accommodation space S is a space surrounded by the substrate 252 , the first optical member 254 , the second optical member 255 and the third optical member 256 . The accommodation space S is provided inside the opening 260 . In the case of this embodiment, the housing space S is open to the atmosphere. That is, the accommodation space S is provided with an air layer AR.

A fourth optical layer 253 is provided between the substrate 252 and the phosphor layer 251 . The area of the fourth optical layer 253 is larger than the area of the back surface 2513 of the phosphor layer 251 . In the case of this embodiment, the fourth optical layer 253 is provided on the support surface 2521 located within the accommodation space S. As shown in FIG. That is, the fourth optical layer 253 is provided around the phosphor layer 251 on the support surface 2521 of the substrate 252 . The phosphor layer 251 is bonded to the support surface 2521 of the substrate 252 via the fourth optical layer 253 . The fourth optical layer 253 is composed of, for example, a metal layer or a dielectric layer. Note that the fourth optical layer 253 may be provided over the entire support surface 2521 , that is, up to the outside of the accommodation space S. Also, part of the fourth optical layer 253 may be directly formed on the back surface 2513 of the phosphor layer 251 .

The first optical member 254 is arranged to face the support surface 2521 of the substrate 252 . That is, the first optical member 254 is arranged to face the surface 2511 of the phosphor layer 251 . The first optical member 254 is arranged so as not to contact the phosphor layer 251 .

The first optical member 254 is arranged in an inclined state with respect to the surface 2511 of the phosphor layer 251 . The angle formed by the first optical member 254 with respect to the surface 2511 of the phosphor layer 251 is set to an acute angle.

The first optical member 254 includes a translucent substrate 2541 and a first optical layer 2542 . The translucent substrate 2541 is made of glass, for example. The first optical layer 2542 is provided on the inner surface of the translucent substrate 2541 , that is, on the surface facing the phosphor layer 251 . The first optical layer 2542 has the property of transmitting the excitation light EL and reflecting the fluorescence YL. The first optical layer 2542 faces the support surface 2521 of the substrate 252 .
Thereby, the first optical member 254 can transmit the excitation light EL emitted from the light source 22 and reflect the fluorescence YL generated in the phosphor layer 251 .

The second optical member 255 includes a base material 2551 and a second optical layer 2552 . Glass, for example, is used as a material for forming the base material 2551 . A second optical layer 2552 is formed on the inner surface of the substrate 2551 . The second optical layer 2552 is composed of, for example, a metal layer or a dielectric layer.

The second optical member 255 is arranged so as to intersect the supporting surface 2521 of the substrate 252 and the first optical member 254 . The second optical member 255 is arranged such that the second optical layer 2552 intersects the supporting surface 2521 and the first optical layer 2542 . The second optical member 255 may be orthogonal to the support surface 2521 of the substrate 252 and the first optical member 254 . The second optical layers 2552 may be orthogonal to the support surface 2521 and the first optical layers 2542 . The second optical member 255 is arranged so that its thickness direction coincides with the Z-axis direction. The second optical member 255 is arranged near the +Z side of the phosphor layer 251 . Therefore, part of the fluorescence YL emitted from the phosphor layer 251 toward the +Z side is reflected by the second optical member 255 .
For example, even if the excitation light EL enters the second optical member 255 for some reason, the second optical member 255 reflects the excitation light EL to enter the phosphor layer 251 .

The second optical member 255 has a trapezoidal plate shape.
As shown in FIG. 3, the second optical member 255 includes a first end face 55a that forms the upper base of the trapezoid, a second end face 55b that forms the lower base of the trapezoid, the first end face 55a and the second end face 55b. on the +X side, and a fourth end face 55d on the -X side that connects the first end face 55a and the second end face 55b. The first end surface 55a, the second end surface 55b, the third end surface 55c and the fourth end surface 55d are all flat surfaces. The third end surface 55 c is a surface facing the substrate 252 . The fourth end surface 55d is the surface of the substrate 2551 opposite to the third end surface 55c. The first optical member 254 is in contact with the fourth end surface 55d. The first optical member 254 is mounted on the fourth end surface 55d. The first optical layer 2542 is in contact with the fourth end surface 55d. A translucent substrate 2541 is placed on the fourth end face 55d with a first optical layer 2542 interposed therebetween.

Here, when glass is used as the material of the base material 2551, a chamfering process is required to prevent chipping by removing sharp portions. In the present embodiment, the second optical member 255 is shaped like a trapezoidal plate to eliminate the need for chamfering, thereby improving workability of the base material 2551 .

In this embodiment, part of the second optical member 255 is embedded in the substrate 252 . Therefore, the second optical member 255 is firmly supported by the substrate 252 .
A portion of the +X side end of the second optical member 255 is fitted in a groove 2524 formed in the support surface 2521 of the substrate 252 . Note that the gap between the second optical member 255 and the groove 2524 may be filled with an adhesive.

Specifically, in the second optical member 255, the entire first end surface 55a and the third end surface 55c and part of the second end surface 55b are fitted in the groove 2524. As shown in FIG. Of the fourth end face 55d, the end side 55d1 located on the most −Y side and extending in the Z direction is flush with the supporting surface 2521 of the substrate 252. As shown in FIG. Thereby, the fourth end surface 55d and the support surface 2521 of the substrate 252 are smoothly connected. In addition, the second end surface 55b is flush with the end surface 52 of the substrate 252 on the +Y side.

The third optical member 256 has a configuration similar to that of the second optical member 255 .
That is, the third optical member 256 includes a base material 2561 and a third optical layer 2562 . A third optical layer 2562 is formed on the inner surface of the substrate 2561 . The third optical layer 2562 is composed of, for example, a metal layer or a dielectric layer.

The third optical member 256 is arranged so as to intersect the support surface 2521 of the substrate 252 and the first optical member 254 and face the second optical member 255 . The third optical member 256 is arranged such that the third optical layer 2562 intersects the support surface 2521 and the first optical layer 2542 and faces the second optical layer 2552 . The third optical member 256 may be orthogonal to the support surface 2521 of the substrate 252 and the first optical member 254 . The third optical layer 2562 may be orthogonal to the support surface 2521 and the first optical layer 2542 . The third optical member 256 is arranged so that its thickness direction coincides with the Z-axis direction. The third optical member 256 is arranged near the −Z side of the phosphor layer 251 . Therefore, the fluorescence YL emitted from the phosphor layer 251 toward the −Z side and incident on the third optical member 256 is reflected by the third optical member 256 . For example, even if the excitation light EL enters the third optical member 256 for some reason, the third optical member 256 reflects the excitation light EL to enter the phosphor layer 251 .

The third optical member 256 has the same trapezoidal plate shape as the second optical member 255 .
The third optical member 256 includes a first end face 56a forming an upper base of the trapezoidal shape, a second end face 56b forming a lower base of the trapezoidal shape, and a third end face 56b connecting the first end face 56a and the second end face 56b on the +X side. It includes an end face 56c and a fourth end face 56d connecting the first end face 56a and the second end face 56b on the -X side. The first end surface 56a, the second end surface 56b, the third end surface 56c and the fourth end surface 56d are all flat surfaces. The third end surface 56 c is a surface facing the substrate 252 . The fourth end surface 56d is the surface of the base material 2561 opposite to the third end surface 56c. The first optical member 254 is in contact with the fourth end face 56d. The first optical member 254 is mounted on the fourth end face 56d. The first optical layer 2542 is in contact with the fourth end surface 56d. A translucent substrate 2541 is placed on the fourth end surface 56d with a first optical layer 2542 interposed therebetween.

In the case of this embodiment, the third optical member 256 is firmly supported by the substrate 252 by partially embedding the third optical member 256 in the substrate 252 .
A portion of the +X side end of the third optical member 256 is fitted into a groove 2524 formed in the support surface 2521 of the substrate 252 . The gap between the third optical member 256 and the groove 2524 may be filled with an adhesive.

Specifically, the third optical member 256 has the grooves 2524 in which the entire first end surface 56 a and the third end surface 56 c and part of the second end surface 56 b are fitted. An end side 56d1 of the fourth end surface 56d that is located on the most -Y side and extends in the Z direction is flush with the support surface 2521 of the substrate 252. As shown in FIG. Thereby, the fourth end surface 56d and the support surface 2521 of the substrate 252 are smoothly connected. Also, the second end surface 56b is flush with the end surface 52 of the substrate 252 on the +Y side.

In this embodiment, the first optical member 254 is supported by the second optical member 255 and the third optical member 256 . The first optical member 254 is adhesively fixed to the second optical member 255 and the third optical member 256 .
Specifically, the first optical member 254 is provided so as to bridge between the fourth end face 55d of the second optical member 255 and the fourth end face 56d of the third optical member 256 . The inner edge 54a of the first optical member 254 is in contact with the supporting surface 2521 of the substrate 252 on the -Y side.

Based on such a configuration, in the wavelength conversion element 25 of the present embodiment, the −Y side opposite to the opening 260 is the substrate 252, the first optical member 254, the second optical member 255, and the third optical member 256. blocked by Therefore, the wavelength conversion element 25 prevents the fluorescent light YL from leaking from the side opposite to the opening 260 , so that the fluorescent light YL can be efficiently emitted from the opening 260 .

As shown in FIGS. 4 and 5 , the excitation light EL passes through the first optical member 254 and enters the phosphor layer 251 . The excitation light EL is incident on the phosphor layer 251 so as to be condensed on the surface 2511 by the first condensing optical system 24 . An excitation light incident region LS is formed on the surface 2511 of the phosphor layer 251 . The excitation light incident area LS corresponds to an irradiation spot formed on the surface 2511 by the excitation light EL.

The phosphor layer 251 is excited by the excitation light EL incident on the excitation light incident region LS, and emits fluorescence YL in Lambertian luminescence. The area of the region where the fluorescence YL is emitted is larger than the area of the excitation light incident region LS.

Fluorescence YL is Lambertian light emitted from the phosphor layer 251 . For example, part of the fluorescence YL emitted from the surface 2511 in Lambertian light enters the first optical member 254 arranged to face the surface 2511 . The fluorescence YL incident on the first optical member 254 is reflected by the first optical layer 2542 . A portion of the fluorescence YL reflected by the first optical layer 2542 is directly emitted from the opening 260 .
Also, part of the fluorescence YL reflected by the first optical layer 2542 enters the support surface 2521 of the substrate 252 and is reflected by the fourth optical layer 253 formed on the support surface 2521 . The fluorescence YL reflected by the fourth optical layer 253 is emitted from the opening 260, or enters the first optical member 254 again and is reflected.

Part of the fluorescence YL reflected by the first optical layer 2542 is returned into the phosphor layer 251 . The phosphor layer 251 of this embodiment includes a plurality of pores K. FIG. Therefore, the fluorescence YL that has returned into the phosphor layer 251 is scattered by the pores K, so that the phosphor layer 251 emits Lambertian light again.

Also, part of the fluorescence YL emitted from the side surface 2512 of the phosphor layer 251 passes through the fourth optical layer 253 and enters the second optical member 255 or the third optical member 256, or enters the second optical member. 255 or the third optical member 256 directly. The fluorescence YL is reflected by the second optical member 255 or the third optical member 256, and then enters the first optical member 254 again and is reflected.

Part of the fluorescence YL generated in the phosphor layer 251 propagates in the direction opposite to the opening 260 (-Y side), but is eventually emitted from the opening 260 by repeated reflection.
Thus, in the wavelength conversion element 25 of this embodiment, the fluorescence YL generated by the phosphor layer 251 can be emitted from the opening 260 to the +Y side.

In the wavelength conversion element 25 of the present embodiment, in the phosphor layer 251, heat tends to accumulate and the temperature tends to rise on the −Y side, which is the side opposite to the opening 260, compared to the opening 260 side from which the fluorescence YL is emitted. . On the other hand, in the wavelength conversion element 25 of the present embodiment, as shown in FIGS. 3 and 5, the substrate 252 supporting the phosphor layer 251 is elongated toward the side opposite to the opening 260. . Therefore, according to the wavelength conversion element 25 of the present embodiment, the side of the phosphor layer 251 opposite to the opening 260 where heat tends to accumulate can be efficiently cooled. Therefore, the phosphor layer 251 can be efficiently cooled.

In the wavelength conversion element 25 of this embodiment, the area A1 of the surface 2511 of the phosphor layer 251 is made larger than the area A2 of the excitation light incident region LS. Further, in the wavelength conversion element 25 of the present embodiment, the angle between the plane along the first optical layer 2542 of the first optical member 254 and the plane along the surface 2511 is set to 10° or more and 40° or less. The area A3 of the portion 260 is made smaller than the area A2 of the excitation light incident region LS.

That is, in the wavelength conversion element 25 of this embodiment, the area A1 of the surface 2511 of the phosphor layer 251 is larger than the area A2 of the excitation light incident region LS, and the area A2 of the excitation light incident region LS is larger than the area A3 of the opening 260. getting bigger. In the wavelength conversion element 25 of the present embodiment, the opening 260 can be regarded as an apparent light emitting surface of the fluorescence YL, so the area A3 of the opening 260 can be regarded as an apparent light emitting area of the fluorescence YL.

Fluorescence YL emitted from the wavelength conversion element 25 enters the first pickup optical system 26 . The first pickup optical system 26 is composed of, for example, pickup lenses 26a and 26b. The first pickup optical system 26 has a function of picking up the fluorescence YL emitted from the phosphor layer 251 and collimating it. The focal length of the first pickup optical system 26 for picking up and collimating the fluorescence YL that emits Lambertian light is shorter than the focal length of the second pickup optical system 32 for picking up and collimating the diffuse blue light BL.

The fluorescence YL collimated by the first pickup optical system 26 enters the second optical element 30 . The fluorescence YL is transmitted through the second optical element 30 and directed toward the integrator optical system 35 .

In the light source device 2 of this embodiment, the first optical element 29, the wavelength conversion element 25, and the second optical element 30 are arranged at the corners of the rectangle formed by the optical axes ax3, ax4, ax5 and the illumination optical axis ax1. and a diffusion element 31 are arranged. Thus, in the light source device 2 of the present embodiment, the excitation light EL emitted from the light source 22 is separated into two directions, the X direction and the Y direction, by the first optical element 29, and one of the separated excitation light EL1 is converted into the wavelength conversion element. 25 , and the other separated blue light EL 2 is made incident on the diffusion element 31 . Furthermore, in the light source device 2 of the present embodiment, the fluorescent light YL emitted from the wavelength conversion element 25 in the Y direction is transmitted in the Y direction by the second optical element 30, while the diffused blue light BL emitted from the diffusion element 31 is transmitted. The light is reflected in the Y direction by the second optical element 30 .

In this manner, the second optical element 30 of the present embodiment reflects the diffused blue light BL that is emitted from the diffusion element 31 to one side in the X direction (+X side) and is incident to one side in the Y direction (+Y side). At the same time, the fluorescence YL and the diffused blue light BL are combined by transmitting the YL emitted from the wavelength conversion element 25 to one side in the Y direction (+Y side) and incident thereon to one side in the Y direction (+Y side). A white illumination light WL is generated. Thus, the light source device 2 can emit white illumination light WL toward the integrator optical system 35 .

The white illumination light WL enters the integrator optical system 35 . The integrator optical system 35 is composed of, for example, a first lens array 35a and a second lens array 35b. The first lens array 35a includes a plurality of first lenslets 35am, and the second lens array 35b includes a plurality of second lenslets 35bm.

The first lens array 35a separates the illumination light WL into a plurality of light beam bundles. The first small lenses 35am image the small ray bundles onto the corresponding second small lenses 35bm. The integrator optical system 35 cooperates with a later-described superimposing lens 37 to homogenize the illuminance distribution of the image forming areas of the light modulation devices 4R, 4G, and 4B shown in FIG. 1, which are areas to be illuminated.

The illumination light WL that has passed through the integrator optical system 35 enters the polarization conversion element 36 . The polarization conversion element 36 is composed of, for example, a polarization separation film and a retardation plate (1/2 wavelength plate). The polarization conversion element 36 converts the polarization direction of the illumination light WL into one polarization component.

The illumination light WL that has passed through the polarization conversion element 36 enters the superimposing lens 37 . The illumination light WL emitted from the superimposing lens 37 enters the color separation optical system 3 . The superimposing lens 37 uniformly illuminates the illumination light WL by superimposing the plurality of light beam bundles forming the illumination light WL on the areas to be illuminated of the light modulation devices 4R, 4G, and 4B, that is, the image forming areas.

(Effect of the first embodiment)
The light source device 2 according to this embodiment described above has the following effects.
The wavelength conversion element 25 of this embodiment includes the light source 22 that emits the excitation light EL, the excitation light EL that is incident thereon, the excitation light EL1 that is a part of the excitation light EL, and the other part of the excitation light EL. and a wavelength conversion element 25 that receives the excitation light EL1, converts the wavelength of the excitation light EL1, and emits fluorescence YL in a wavelength band different from that of the excitation light EL1. , a diffusion element 31 that receives the blue light EL2 and diffuses the blue light EL2; and a second optical element that combines the fluorescence YL emitted from the wavelength conversion element 25 and the diffused blue light BL emitted from the diffusion element 31. 30 and. The wavelength conversion element 25 includes a phosphor layer 251 that converts the wavelength of the excitation light EL1 incident on the surface 2511 to generate fluorescence YL, a substrate 252 that has a support surface 2521 that supports the phosphor layer 251, and the excitation light EL. A first optical member 254 having a first optical layer 2542 that transmits and reflects the fluorescence YL, and is arranged such that the first optical layer 2542 faces the support surface 2521, and a second optical member that reflects at least the fluorescence YL. It has a second optical member 255 which has a layer 2552 and is arranged so that the second optical layer 2552 intersects the support surface 2521 and the first optical layer 2542, and a third optical layer 2562 which reflects at least the fluorescence YL. A third optical member 256 arranged so that the third optical layer 2562 intersects the supporting surface 2521 and the first optical layer 2542 and faces the second optical layer 2552, the substrate 252, and the first optical member 254 , and an opening 260 formed by the second optical member 255 and the third optical member 256 . The area A1 of the surface 2511 of the phosphor layer 251 is larger than the area A2 of the excitation light incident region LS on which the excitation light EL is incident on the surface 2511, and the area A2 of the excitation light incident region LS is equal to the area A3 of the opening 260. Larger, fluorescence YL is emitted from opening 260 .

In the light source device 2 of the present embodiment, the excitation light EL emitted from the light source 22 is separated by the first optical element 29 using the half mirror layer 29b, and one of the separated excitation light EL1 is caused to enter the wavelength conversion element 25. , and the other separated blue light EL 2 is made incident on the diffusion element 31 . Then, in the second optical element 30 using the dichroic mirror 30b, the fluorescent light YL emitted from the wavelength conversion element 25 and the diffused blue light BL emitted from the diffusion element 31 are combined to generate white illumination light WL. . As described above, in the light source device 2 of the present embodiment, the illumination light WL can be synthesized without using polarized light, so there is no need to use an expensive retardation plate or an expensive lens member for suppressing polarization disturbance. Therefore, cost reduction of the light source device 2 can be realized.
Further, in the light source device 2 of the present embodiment, in the wavelength conversion element 25, the fluorescence YL is emitted from the opening 260 having a smaller area than the excitation light incident region LS into which the excitation light EL is incident. The apparent emission area of the fluorescent light YL is smaller than in the configuration in which the fluorescent light YL is extracted as it is. This makes it possible to reduce the etendue in the fluorescence YL. Further, in the wavelength conversion element 25 of the present embodiment, the etendue can be reduced without reducing the incident area of the excitation light EL on the phosphor layer 251. Therefore, the optical density of the excitation light EL on the surface 2511 of the phosphor layer 251 is not high. Therefore, it is possible to suppress a decrease in fluorescence conversion efficiency due to an increase in light density.
Therefore, according to the light source device 2 of the present embodiment, since it is provided with the wavelength conversion element 25 that reduces etendue while suppressing a decrease in fluorescence conversion efficiency due to an increase in the light density of the excitation light EL, fluorescence with high luminance YL is generated. be able to.

In the light source device 2 of this embodiment, the first optical element 29 includes a translucent substrate 29a and a half mirror layer 29b provided on the translucent substrate 29a.

According to this configuration, since the first optical element 29 composed of the translucent substrate 29a and the half mirror layer 29b is used, light absorption by the first optical element 29 can be suppressed. Therefore, optical loss of the excitation light EL due to passing through the first optical element 29 can be suppressed.

In the light source device 2 of this embodiment, the second optical element 30 includes a dichroic mirror 30b that transmits the fluorescence YL and reflects the diffuse blue light BL.

According to this configuration, the illumination light WL can be generated by synthesizing the fluorescent light YL and the diffused blue light BL without using polarized light.

In the light source device 2 of the present embodiment, the first optical element 29 directs the excitation light EL incident from the light source 22 in the X direction along the XY plane where the light source 22, the first optical element 29 and the second optical element 30 are arranged. and the Y direction along the XY plane perpendicular to the X direction. The element 25 wavelength-converts the incident excitation light EL1 branched in the X direction from the first optical element 29, and emits fluorescence YL in the Y direction. In the case of this embodiment, the second optical element 30 reflects in the Y direction the diffused blue light BL that is emitted from the diffusion element 31 in the X direction and is incident thereon, and is emitted from the wavelength conversion element 25 in the Y direction and is incident thereon. Illumination light WL is synthesized by transmitting fluorescence YL in the Y direction.

According to this configuration, the excitation light EL emitted from the light source 22 is separated in the X direction and the Y direction by the first optical element 29, and the fluorescence YL generated from the excitation light EL1 separated in the X direction and the fluorescence YL separated in the Y direction. It is possible to realize a light source device that combines the diffused blue light BL generated from the blue light EL2 in the second optical element 30 to generate the illumination light WL.

In the light source device 2 of this embodiment, the phosphor layer 251 includes pores K that scatter light.

According to this configuration, the fluorescence YL re-entering the phosphor layer 251 is diffused inside, so that the re-entering fluorescence YL can be Lambertian radiation.

In the light source device 2 of this embodiment, the angle formed by the first optical member 254 with respect to the surface 2511 of the phosphor layer 251 is 10° or more and 40° or less.

According to this configuration, by bringing the first optical member 254 close to the surface 2511 of the phosphor layer 251, it is possible to realize a configuration in which the area A3 of the opening 260 is smaller than the area A2 of the excitation light incident region LS.

In the light source device 2 of this embodiment, the second optical member 255 includes a second optical layer 2552 that reflects the excitation light EL and the fluorescence YL, and the third optical member 256 includes a second optical layer 2552 that reflects the excitation light EL and the fluorescence YL. 3 optical layers 2562 are included.

With this configuration, the fluorescence YL emitted from the side surface 2512 of the phosphor layer 251 can be reflected back to the phosphor layer 251 . In addition, the excitation light EL can be reflected to enter the phosphor layer 251 . As a result, the utilization efficiency of the excitation light EL and fluorescence YL can be improved.

The light source device 2 of this embodiment further includes a fourth optical layer 253 provided between the substrate 252 and the phosphor layer 251 .

According to this configuration, the fluorescence YL directed toward the substrate 252 can be emitted from the surface 2511 by being reflected within the phosphor layer 251 . Thereby, the light utilization efficiency of the fluorescence YL can be improved.

In the light source device 2 of this embodiment, the fourth optical layer 253 is provided on at least part of the periphery of the phosphor layer 251 on the supporting surface 2521 of the substrate 252 .

With this configuration, the fluorescence YL emitted from the side surface 2512 of the phosphor layer 251 can be reflected back to the phosphor layer 251 . Also, the fluorescence YL emitted from the side surface 2512 of the phosphor layer 251 is reflected and emitted from the opening 260 . Therefore, it is possible to improve the light utilization efficiency of the fluorescence YL.

In the light source device 2 of this embodiment, the first optical member 254 is arranged so as not to contact the phosphor layer 251 .

According to this configuration, the first optical member 254 does not come into contact with the phosphor layer 251 , so deformation and damage of the first optical member 254 due to the heat of the phosphor layer 251 can be suppressed.

In the light source device 2 of this embodiment, the first optical member 254 includes a first optical layer 2542 that transmits the excitation light EL and reflects the fluorescence YL.

According to this configuration, it is possible to efficiently excite the phosphor layer 251 accommodated in the accommodation space S and reflect the generated fluorescence YL to extract it from the opening 260 .

In the light source device 2 of the present embodiment, the phosphor layer 251 is housed in a housing space S provided inside the opening 260, and the housing space S is provided with an air layer AR.

Here, if the housing space S is filled with a prism member such as glass, light is not efficiently emitted from the housing space S to the outside of the opening 260 due to total reflection on the prism exit surface. In contrast, according to the configuration of the present embodiment, since the accommodation space S is filled with the air layer AR, the fluorescent light YL can be favorably emitted from the opening 260 .

The projector 1 according to the present embodiment described above has the following effects.
The projector 1 of the present embodiment includes a light source device 2 and light modulation devices 4B and 4G that form image light by modulating blue light LB, green light LG, and red light LR from the light source device 2 according to image information. , 4R, and a projection optical device 6 for projecting the aforementioned image light.
Thus, according to the projector 1 of the present embodiment, since it includes the light source device 2 that generates the high-brightness fluorescence YL, it is possible to form and project a high-brightness image.

(Second embodiment)
Next, the light source device of the second embodiment will be described. The light source device of this embodiment differs from the light source device of the first embodiment in the positions of the wavelength conversion element 25 and the diffusion element 31 .

FIG. 6 is a schematic configuration diagram of the light source device 2A of this embodiment. In addition, the same code|symbol is attached|subjected about the structure and member which are common in 1st Embodiment, and description is abbreviate|omitted about details.
As shown in FIG. 6, in the light source device 2A of the present embodiment, the light source 22, the first optical element 29, the second homogenizer optical system 27, and the second condensing optical system are arranged on the optical axis ax3 of the light source 22. 28 and a diffusing element 31 are arranged. In the light source device 2A of this embodiment, the first optical element 29, the first homogenizer optical system 23, the first condensing optical system 24, and the wavelength conversion element 25 are arranged on the optical axis ax4. In the light source device 2A of this embodiment, the wavelength conversion element 25, the first pickup optical system 26, and the second optical element 130 are arranged on the optical axis ax6 along the principal ray of the fluorescence YL emitted from the wavelength conversion element 25. are placed. In the light source device 2A of this embodiment, the diffusion element 31, the second pickup optical system 32, the second optical element 130, the integrator optical system 35, the polarization conversion element 36, and the superimposing lens are arranged on the illumination optical axis ax1. 37 are arranged.

In the present embodiment, part of the excitation light EL transmitted through the first optical element 29 and separated in the X direction (first direction) is referred to as blue light (part of light in the first wavelength band) EL2. Another portion of the excitation light EL reflected by the optical element 29 and separated in the Y direction (second direction) is referred to as excitation light (another portion of the light in the first wavelength band) EL1.

The blue light EL2 that has passed through the first optical element 29 travels in the X direction along the optical axis ax3 and enters the diffusion element 31 via the second homogenizer optical system 27 and the second condensing optical system .

In the diffusion element 31 of this embodiment, the light incident surface of the diffuse reflection plate 31a is rotatable within a plane forming an angle of 45° with the optical axis ax3 and the illumination optical axis ax1. The diffusion element 31 reflects the blue light EL2 branched from the first optical element 29 and incident in the X direction to one side (+Y side) in the Y direction (second direction) as diffused blue light BL. In this embodiment, the chief ray of the diffused blue light BL coincides with the illumination optical axis ax1.

The diffused blue light BL emitted from the diffusion element 31 is collimated by the second pickup optical system 32 and enters the second optical element 130 . The second optical element 130 of this embodiment includes a translucent substrate 130a and a dichroic mirror 130b. The translucent substrate 130a of the present embodiment is a substrate transmissive to at least diffuse blue light BL, which is light in the first wavelength band. The dichroic mirror 130b of the present embodiment reflects fluorescence YL, which is light in the second wavelength band emitted from the wavelength conversion element 25, and diffuse blue light, which is light in the first wavelength band emitted from the diffusion element 31. It has an optical characteristic of transmitting light BL. Therefore, the second optical element 130 transmits the diffused blue light BL to one side (+Y side) in the Y direction.

On the other hand, the excitation light (another part of the light in the first wavelength band) EL1 reflected by the first optical element 29 travels in the Y direction along the optical axis ax4 and passes through the first homogenizer optical system 23 and the first condensing light. The light enters the wavelength conversion element 25 via the optical system 24 . The wavelength conversion element 25 of the present embodiment directs the fluorescence YL generated by being excited by the excitation light EL1 incident along the Y direction toward one side (+X side) in the X direction (first direction). Launch from 260.

The fluorescence YL emitted from the wavelength conversion element 25 is collimated by the first pickup optical system 26 and enters the second optical element 130 . The second optical element 130 of the present embodiment transmits diffused blue light BL emitted from the diffusion element 31 to one side in the Y direction (+Y side) and incident thereon, to one side in the Y direction (+Y side). By reflecting YL emitted from the conversion element 25 to one side in the X direction (+X side) and incident thereon to one side in the Y direction (+Y side), white illumination light obtained by synthesizing the fluorescence YL and the diffused blue light BL Generate WL. In this manner, the light source device 2A of this embodiment can emit white illumination light WL toward the integrator optical system 35 .

(Effect of Second Embodiment)
In the light source device 2A of the present embodiment, the first optical element 29 branches the excitation light EL incident from the light source 22 into the X direction and the Y direction, and the diffusion element 31 branches from the first optical element 29 in the X direction. The wavelength conversion element 25 diffusely reflects the incident blue light EL2 in the Y direction, and the wavelength conversion element 25 converts the wavelength of the excitation light EL1 that is branched from the first optical element 29 in the Y direction, and converts the fluorescence YL in the X direction. inject. In the case of this embodiment, the second optical element 130 transmits in the Y direction the diffused blue light BL that is emitted from the diffusion element 31 in the Y direction and is incident thereon, and is emitted from the wavelength conversion element 25 in the X direction and is incident thereon. The illumination light WL is synthesized by reflecting the fluorescence YL in the Y direction.

According to the light source device 2A of the present embodiment, the excitation light EL emitted from the light source 22 is separated in the X direction and the Y direction by the first optical element 29, and the diffused blue light BL is generated from the blue light EL2 separated in the X direction. and the fluorescence YL generated from the excitation light EL1 separated in the Y direction are combined in the second optical element 130 to generate the illumination light WL. Therefore, in the light source device 2A of the present embodiment, similarly to the light source device 2 of the first embodiment, since the illumination light WL is synthesized without using polarized light, an expensive retardation plate and an expensive light source for suppressing polarization disturbance are required. Cost reduction can be achieved without using an expensive lens member. Further, since the wavelength conversion element 25 is provided with a reduced etendue while suppressing a decrease in fluorescence conversion efficiency due to an increase in the light density of the excitation light EL, it is possible to generate high-brightness fluorescence YL.

(Third embodiment)
Next, the light source device of the third embodiment will be described. The light source device of this embodiment differs from the light source device of the first embodiment in the configuration of the diffusing element 31 .

FIG. 7 is a schematic configuration diagram of the light source device 2B of this embodiment. In addition, the same code|symbol is attached|subjected about the structure and member which are common in 1st Embodiment, and description is abbreviate|omitted about details.
As shown in FIG. 7, in the light source device 2B of this embodiment, a first optical element 29, a second homogenizer optical system 27, a second condensing optical system 28, and a mirror 132 are arranged on the optical axis ax4. are placed. A mirror 132, a diffusion element 131, a second pickup optical system 32, and a second optical element 30 are arranged on the optical axis ax5.

The mirror 132 reflects, in the X direction, the blue light EL2 branched from the first optical element 29 and incident in the Y direction. The mirror 132 is composed of, for example, a metal film or a dielectric film. The mirror 132 is arranged to form an angle of 45° with the optical axes ax4 and ax5. In this embodiment, the chief ray of the blue light EL2 reflected by the mirror 132 coincides with the optical axis ax5.

Blue light EL2 reflected by the mirror 132 is incident on the diffusion element 131 . The diffusion element 131 diffuses the blue light EL2 toward the second optical element 30 and emits it to one side (+X side) in the X direction. The diffusion element 131 is desirably formed so as to diffuse the blue light EL2 so that the diffusion angle is approximately the same as that of the fluorescence YL emitted from the wavelength conversion element 25 . As a result, it is possible to reduce the color unevenness of the illumination light WL obtained by synthesizing the diffused blue light EL2 and the fluorescent light YL. The diffusion element 131 of this embodiment is made of, for example, frosted glass.

Although both the diffusing element 131 and the mirror 132 of this embodiment are fixed elements, rotating elements may be used instead of this configuration. In this case, by rotating the diffusing element 131 and the mirror 132, the temperature rise of the diffusing element 131 and the mirror 132 can be suppressed, and the reliability can be improved.

The blue light EL2 diffusely reflected by the diffusion element 131 is hereinafter referred to as diffused blue light BL. In this embodiment, the chief ray of the diffused blue light BL coincides with the optical axis ax5.

As described above, the diffusing element 131 of this embodiment diffuses the blue light EL2, which is branched from the first optical element 29 in the Y direction and reflected in the X direction by the mirror 132, to one side (+X side) in the X direction. The blue light BL is diffused and emitted. The diffused blue light BL emitted from the diffusion element 131 is collimated by the second pickup optical system 32, enters the second optical element 30, is combined with the fluorescence YL emitted from the wavelength conversion element 25, and is converted into the illumination light WL. Generate.

(Effect of the third embodiment)
In the light source device 2B of this embodiment, the first optical element 29 branches the excitation light EL incident from the light source 22 into the X direction and the Y direction, and the mirror 132 branches from the first optical element 29 in the Y direction. The diffusion element 131 diffuses the blue light EL2 incident in the X direction from the mirror 132 and emits diffused blue light BL in the X direction. The wavelength conversion element 25 converts the wavelength of the excitation light EL1 branched from the first optical element 29 and incident in the X direction, and emits fluorescence YL in the Y direction. In the case of this embodiment, the second optical element 30 reflects in the Y direction the diffused blue light BL that is emitted from the diffusion element 31 in the X direction and is incident thereon, and is emitted from the wavelength conversion element 25 in the Y direction and is incident thereon. Illumination light WL is synthesized by transmitting fluorescence YL in the Y direction.

According to the light source device 2B of the present embodiment, the excitation light EL emitted from the light source 22 is separated in the X direction and the Y direction by the first optical element 29, and the diffused blue light BL is generated from the blue light EL2 separated in the Y direction. Illumination light WL can be generated by synthesizing fluorescence YL generated by wavelength-converting the excitation light EL1 separated in the X direction by the wavelength conversion element 25 in the second optical element 30 . Therefore, in the light source device 2B of the present embodiment, similarly to the light source device 2 of the first embodiment, since the illumination light WL is synthesized without using polarized light, an expensive retardation plate and an expensive light source for suppressing polarization disturbance are required. Cost reduction can be achieved without using an expensive lens member. Further, since the wavelength conversion element 25 is provided with a reduced etendue while suppressing a decrease in fluorescence conversion efficiency due to an increase in the light density of the excitation light EL, it is possible to generate high-brightness fluorescence YL.
Further, in the case of this embodiment, since the mirror 132 is provided separately from the diffusing element 131, the diffusing element 131 can be designed by considering only the diffusion performance, and the design of the diffusing element 131 is facilitated.

(Fourth embodiment)
Next, a light source device according to the fourth embodiment will be described. The light source device of this embodiment differs from the light source device of the third embodiment in the positions of the wavelength conversion element 25, diffusion element 131, and mirror 132. FIG. That is, the light source device of this embodiment has a configuration in which the configurations of the second embodiment and the third embodiment are combined.

FIG. 8 is a schematic configuration diagram of the light source device 2C of this embodiment. In addition, the same code|symbol is attached|subjected about the structure and member which are common in 1st Embodiment, and description is abbreviate|omitted about details.
As shown in FIG. 8, in the light source device 2C of the present embodiment, the light source 22, the first optical element 29, the second homogenizer optical system 27, and the second condensing optical system are arranged on the optical axis ax3 of the light source 22. 28 and a mirror 132 are arranged. A first optical element 29, a first homogenizer optical system 23, a first condensing optical system 24, and a wavelength conversion element 25 are arranged on the optical axis ax4. In the light source device 2C of the present embodiment, the wavelength conversion element 25, the first pickup optical system 26, and the second optical element 130 are arranged on the optical axis ax6 along the principal ray of the fluorescence YL emitted from the wavelength conversion element 25. are placed. In the light source device 2C of this embodiment, a mirror 132, a diffusion element 131, a second pickup optical system 32, a second optical element 130, an integrator optical system 35, and a polarization conversion element 36 are arranged on the illumination optical axis ax1. , and a superimposing lens 37 are arranged.

In the present embodiment, part of the excitation light EL transmitted through the first optical element 29 and separated in the X direction (first direction) is referred to as blue light (part of light in the first wavelength band) EL2. Another portion of the excitation light EL reflected by the optical element 29 and separated in the Y direction (second direction) is referred to as excitation light (another portion of the light in the first wavelength band) EL1.

The excitation light EL1 reflected by the first optical element 29 travels in the Y direction along the optical axis ax4 and enters the wavelength conversion element 25 via the first homogenizer optical system 23 and the first condensing optical system 24 . The fluorescence YL emitted from the wavelength conversion element 25 in the Y direction is collimated by the first pickup optical system 26 and enters the second optical element 130 .

The mirror 132 reflects, in the Y direction, the blue light EL2 branched from the first optical element 29 and incident in the X direction. The mirror 132 of this embodiment is arranged to form an angle of 45° with the optical axis ax3 and the illumination optical axis ax1. In this embodiment, the chief ray of the blue light EL2 reflected by the mirror 132 coincides with the illumination optical axis ax1.

Blue light EL2 reflected by the mirror 132 is incident on the diffusion element 131 . The diffusion element 131 diffuses the blue light EL2 toward the second optical element 30 and emits the diffused blue light BL to one side (+Y side) in the Y direction. In this embodiment, the chief ray of the diffused blue light BL coincides with the illumination optical axis ax1.

As described above, the diffusion element 131 of this embodiment diffuses the blue light EL2, which is branched from the first optical element 29 in the X direction and reflected in the Y direction by the mirror 132, to one side (+Y side) in the Y direction. The blue light BL is diffused and emitted. The diffused blue light BL emitted from the diffusion element 131 is collimated by the second pickup optical system 32 and enters the second optical element 30 .

The second optical element 130 of the present embodiment transmits the diffused blue light BL emitted from the diffusion element 131 to one side in the Y direction (+Y side) and incident thereon to one side in the Y direction (+Y side). By reflecting YL emitted from the conversion element 25 to one side in the X direction (+X side) and incident thereon to one side in the Y direction (+Y side), white illumination light obtained by synthesizing the fluorescence YL and the diffused blue light BL Generate WL.

(Effect of the fourth embodiment)
In the light source device 2C of this embodiment, the first optical element 29 branches the excitation light EL incident from the light source 22 into the X direction and the Y direction, and the mirror 132 branches from the first optical element 29 in the X direction. The diffusion element 131 diffuses the blue light EL2 incident in the Y direction from the mirror 132 and emits diffused blue light BL in the Y direction. The wavelength conversion element 25 converts the wavelength of the excitation light EL1 branched from the first optical element 29 and incident in the Y direction, and emits fluorescence YL in the X direction. In the case of this embodiment, the second optical element 130 transmits in the Y direction the diffused blue light BL that is emitted from the diffusion element 31 in the Y direction and is incident thereon, and is emitted from the wavelength conversion element 25 in the X direction and is incident thereon. The illumination light WL is synthesized by reflecting the fluorescence YL in the Y direction.

According to the light source device 2C of the present embodiment, the excitation light EL emitted from the light source 22 is separated in the X direction and the Y direction by the first optical element 29, and the diffused blue light BL is generated from the blue light EL2 separated in the X direction. Illumination light WL can be generated by synthesizing fluorescence YL generated by wavelength-converting the excitation light EL1 separated in the Y direction by the wavelength conversion element 25 in the second optical element 130 . Therefore, in the light source device 2C of the present embodiment, similarly to the light source device 2 of the first embodiment, since the illumination light WL is synthesized without using polarized light, an expensive retardation plate and an expensive light source for suppressing polarization disturbance are required. Cost reduction can be achieved without using an expensive lens member. Further, since the wavelength conversion element 25 is provided with a reduced etendue while suppressing a decrease in fluorescence conversion efficiency due to an increase in the light density of the excitation light EL, it is possible to generate high-brightness fluorescence YL. In addition, in the case of this embodiment, since the mirror 132 is provided separately from the diffusion element 131, the diffusion element 131 can be designed by considering only the diffusion performance, and the design of the diffusion element 131 is facilitated.

(Fifth embodiment)
Next, the light source device of the fifth embodiment will be described. The light source device of this embodiment differs from the light source device of the first embodiment in that a reflecting element is provided.
In the above embodiment, the excitation light EL incident on the wavelength conversion element 25 is entirely converted into fluorescence YL, and only the fluorescence YL is emitted from the wavelength conversion element 25. As shown in FIG. However, part of the excitation light EL backscattered by the phosphor layer 251 may be emitted to the outside from the opening 260 . A portion of the excitation light EL that is backscattered and emitted from the opening 260 is hereinafter referred to as backscattered light.

FIG. 9 is a schematic configuration diagram of the light source device 2D of this embodiment. In addition, the same code|symbol is attached|subjected about the structure and member which are common in 1st Embodiment, and description is abbreviate|omitted about details.
As shown in FIG. 9, in the light source device 2D of the present embodiment, a diffusing element 31, a second pickup optical system 32, a second optical element 30, and a reflecting element 40 are arranged on the optical axis ax5. ing.

In this embodiment, it is assumed that backscattered light EL3, which is light in the first wavelength band, is emitted from the opening 260 of the wavelength conversion element 25 together with the fluorescence YL. Backscattered light EL 3 emitted from the wavelength conversion element 25 is collimated by the first pickup optical system 26 and enters the second optical element 30 . Since the backscattered light EL3 is part of the excitation light EL, it is reflected by the second optical element 30 toward the +X side.

Backscattered light EL3 reflected by the second optical element 30 is incident on the reflecting element 40 . The reflective element 40 reflects the backscattered light EL3 emitted from the wavelength conversion element 25 and passed through the second optical element 30 . The reflective element 40 is composed of a metal mirror or a dielectric mirror.

The reflective element 40 reflects the backscattered light EL3 to the -X side. The backscattered light EL3 reflected by the reflecting element 40 is reflected again by the second optical element 30 and enters the wavelength conversion element 25 via the first pickup optical system 26 . At least part of the backscattered light EL3 incident on the wavelength conversion element 25 is incident on the phosphor layer 251 and reused to generate fluorescence YL.

(Effect of the fifth embodiment)
According to the light source device 2D of the present embodiment, when the backscattered light EL3 is emitted from the opening 260 of the wavelength conversion element 25, the reflection element 40 can return the backscattered light EL3 to the wavelength conversion element 25 side. . As a result, the backscattered light EL3 is used for re-excitation of the fluorescence YL, so that it is possible to provide a light source device in which the light utilization efficiency of the excitation light EL emitted from the light source 22 is improved.

Note that the reflecting element 40 of this embodiment can be applied to any of the configurations of the second to fourth embodiments.

Although one embodiment of the present invention has been illustrated and described above, the present invention is not necessarily limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention. is.

(First modification)
FIG. 10 is a cross-sectional view showing a configuration according to a first modified example of the first optical element. In addition, in this modification, the same code|symbol is attached|subjected about the structure or member which is common in the said embodiment, and description is abbreviate|omitted about details.

As shown in FIG. 10, the first optical element 129 of this modified example has a plurality of optical members 1290 . In the case of this modification, the plurality of optical members 1290 includes an optical member 1291 , an optical member 1292 and an optical member 1293 . Note that the number of optical members 1290 is not limited to this, and may be two or four or more.

The optical member 1291, the optical member 1292, and the optical member 1293 are elements that transmit part of the excitation light EL and reflect another part of the excitation light EL. The optical member 1291 includes a translucent substrate 1291a and a half mirror layer 1291b. The optical member 1292 includes a translucent substrate 1292a and a half mirror layer 1292b. The optical member 1293 includes a translucent substrate 1293a and a half mirror layer 1293b. Each translucent substrate 1291a, 1292a, 1293a is a substrate translucent to the excitation light EL. Each half mirror layer 1291b, 1292b, 1293b is composed of a dielectric multilayer film formed on each translucent substrate 1291a, 1292a, 1293a. In this modification, the half mirror layers 1291b, 1292b, and 1293b have different ratios of the amount of transmitted light and the amount of reflected light in the excitation light EL. Therefore, each optical member 1291, 1292, 1293 has a different reflectance or transmittance with respect to the excitation light EL. In the case of this modification, for example, the reflectance with respect to the excitation light EL increases in order of the optical members 1291, 1292, and 1293. FIG.

In the first optical element 129 of this modified example, each optical member 1291, 1292, 1293 is held by a drive section (not shown). Thereby, the first optical element 129 can replace each optical member 1291, 1292, 1293 independently with respect to the optical path of the excitation light EL. That is, the first optical element 129 can arrange any one of the optical members 1291, 1292, and 1293 on the optical path of the excitation light EL. Each optical member 1291, 1292, 1293 is arranged on the optical path of the excitation light EL so as to form an angle of 45° with respect to the optical axis ax3 and the optical axis ax4.
Thereby, the first optical element 129 of this modified example can vary the ratio of the amount of transmitted light and the amount of reflected light in the excitation light EL.

The timing for replacing the optical members 1291, 1292, and 1293 is, for example, when a temperature change or deterioration of the light source 22 is detected, when the total driving time of the light source 22 exceeds a threshold, or when the phosphor layer 251 is changed. A case where deterioration is detected can be considered.

A case where the first optical element 129 of this modified example is applied to the light source device 2 of the first embodiment will be described below.
When the first optical element 129 relatively reduces the amount of reflected light of the excitation light EL and relatively increases the amount of transmitted light of the excitation light EL, the optical member 1291 with the lowest reflectance is arranged on the optical path of the excitation light EL. . As a result, the excitation light EL incident on the optical member 1291 can generate a larger amount of excitation light EL1, which is transmitted light in the X direction, than blue light EL2, which is reflected light in the Y direction.

When the first optical element 129 relatively increases the amount of reflected light of the excitation light EL and relatively decreases the amount of transmitted light of the excitation light EL, the optical member 1293 having the highest reflectance is placed on the optical path of the excitation light EL. Deploy. As a result, the excitation light EL incident on the optical member 1293 can generate a larger amount of blue light EL2, which is reflected light in the Y direction, than the excitation light EL1, which is transmitted light in the X direction.

In addition, in the first optical element 129, in order to reduce the light amount difference between the excitation light EL1 and the blue light EL2, the optical member 1292 may be arranged on the optical path of the excitation light EL.

As described above, according to the first optical element 129 of this modified example, the optical members 1291, 1292, and 1293 are exchanged with respect to the optical path of the excitation light EL, so that the excitation light EL1 incident on the wavelength conversion element 25 and the diffused light are diffused. The ratio of blue light EL2 incident on the element 31 can be changed. Thereby, the color balance (white balance) of the illumination light WL can be controlled by changing the ratio of the diffused blue light BL and the fluorescent light YL.

(Second modification)
FIG. 11A is a cross-sectional view showing a configuration according to a second modified example of the first optical element. In addition, in this modification, the same code|symbol is attached|subjected about the structure or member which is common in the said embodiment, and description is abbreviate|omitted about details.

As shown in FIG. 11A, the first optical element 229 of this modified example is arranged on the optical path of the excitation light EL so as to form an angle of 45° with respect to the optical axis ax3 and the optical axis ax4. The first optical element 229 of this modified example includes an optical substrate 230 and a motor (driving unit) 231 for rotating the optical substrate 230 . The optical substrate 230 transmits part of the excitation light EL in the X direction and reflects another part of the excitation light EL in the Y direction. The optical substrate 230 includes a translucent substrate 2300 and a half mirror layer 2310 .

The rotation axis O1 of the motor 231 is arranged to form an angle of 45° with the optical axis ax3 and the optical axis ax4. This allows the first optical element 229 to rotate the light incident surface of the optical substrate 230 within a plane forming an angle of 45° with the optical axes ax3 and ax4. The optical substrate 230 is, for example, circular when viewed from the direction of the rotation axis O1, but the shape of the optical substrate 230 is not limited to a disc.

FIG. 11B is a plan view of the first optical element of this modified example. FIG. 11B is a plan view of the first optical element 229 along the rotation axis O1. Hereinafter, when viewed from the direction along the rotation axis O1, the direction along the periphery of the rotation axis O1 may be referred to as the radial direction.
As shown in FIG. 11B, in the first optical element 229 of this modified example, the optical substrate 230 includes a plurality of incident areas on which the excitation light EL is incident. In the case of this modification, the multiple incident areas include a first incident area D1, a second incident area D2 and a third incident area D3. The first incident area D1, the second incident area D2 and the third incident area D3 are provided on the optical substrate 230 such that their positions are different from each other in the radial direction. In this modified example, a case where there are three light incident regions will be described, but the number of light incident regions is not limited to this.

The first incident area D1, the second incident area D2, and the third incident area D3 have different reflectances or transmittances with respect to the excitation light EL. In the case of this modification, by varying the configurations of the half mirror layers 2310 corresponding to the first incident region D1, the second incident region D2, and the third incident region D3, for example, the first incident region D1, the second incident region The reflectance with respect to the excitation light EL was increased in order of the region D2 and the third incident region D3.

In the first optical element 229 of this modified example, the optical substrate 230 is rotated by the motor 231, and the first incident region D1, the second incident region D2 and the third incident region D3 located on the optical path of the excitation light EL are detected. can be switched. That is, the first optical element 229 can arrange any one of the first incident area D1, the second incident area D2, and the third incident area D3 on the optical path of the excitation light EL. The first incident area D1, the second incident area D2 and the third incident area D3 are arranged on the optical path of the excitation light EL so as to form an angle of 45° with respect to the optical axis ax3 and the optical axis ax4.
Thereby, the first optical element 229 of this modified example can vary the ratio of the amount of transmitted light and the amount of reflected light in the excitation light EL.

The timing for rotating the optical substrate 230 may be, for example, when a temperature change or deterioration of the light source 22 is detected, when the total driving time of the light source 22 exceeds a threshold, or when deterioration of the phosphor layer 251 is detected. It is possible that

A case where the first optical element 229 of this modified example is applied to the light source device 2 of the first embodiment will be described below.
When the first optical element 229 relatively reduces the reflected light amount of the excitation light EL and relatively increases the transmitted light amount of the excitation light EL, the first incident region D1 having the lowest reflectance is placed on the optical path of the excitation light EL. position. As a result, the excitation light EL incident on the first incident region D1 can generate a larger amount of excitation light EL1, which is transmitted light in the X direction, than blue light EL2, which is reflected light in the Y direction. can.

In addition, in the first optical element 229, when the amount of reflected light of the excitation light EL is relatively increased and the amount of transmitted light of the excitation light EL is relatively decreased, the third incident region having the highest reflectance is placed on the optical path of the excitation light EL. Place D3. As a result, the excitation light EL incident on the third incident region D3 can generate a larger amount of blue light EL2, which is reflected light in the Y direction, than the excitation light EL1, which is transmitted light in the X direction. can.

In addition, in the first optical element 229, in order to reduce the light amount difference between the excitation light EL1 and the blue light EL2, the second incident region D2 may be arranged on the optical path of the excitation light EL.

As described above, according to the first optical element 229 of this modified example, by rotating the optical substrate 230 by the motor 231, the excitation light EL1 incident on the wavelength conversion element 25 and the blue light EL2 incident on the diffusion element 31 are can vary. Thereby, the color balance (white balance) of the illumination light WL can be controlled by changing the ratio of the diffused blue light BL and the fluorescent light YL.

(Third modification)
In the second modified example, the case where the first incident region D1, the second incident region D2, and the third incident region D3 having different reflectances of the excitation light EL are arranged in order in the radial direction of the optical substrate 230 is taken as an example. , the configuration of the first optical element is not limited to this. This modification differs from the second modification in that the reflectance for the excitation light EL is continuously changed. In addition, in this modification, the same code|symbol is attached|subjected about the structure or member which is common in the said 2nd modification, and description is abbreviate|omitted about details.

FIG. 12 is a plan view showing a configuration according to a third modified example of the first optical element.
As shown in FIG. 12, the first optical element 329 of this modified example has a configuration in which the reflectance with respect to the excitation light EL is continuously changed in the radial direction of the light incident surface of the optical substrate 230 . According to this configuration, the optical substrate 230 can be rotated by the motor 231 to switch the light incident surface positioned on the optical path of the excitation light EL. Thereby, the first optical element 329 of this modified example can vary the ratio of the transmitted light amount and the reflected light amount in the excitation light EL.

According to the first optical element 329 of this modified example, by rotating the optical substrate 230 with the motor 231, the ratio of the excitation light EL1 incident on the wavelength conversion element 25 and the blue light EL2 incident on the diffusion element 31 can be changed. It can be changed in more detail. Therefore, according to this modified example, it is possible to more precisely control the color balance (white balance) of the illumination light WL. Therefore, by using the first optical element 329 of this modified example, it is possible to provide a light source device with excellent color reproducibility.

In addition, in the above-described embodiment and modified example, the case where the width in the Z direction of the back surface 2513 of the phosphor layer 251 is narrower than the width in the Z direction of the support surface 2521 located in the accommodation space S is taken as an example. The width in the Z direction of the back surface 2513 of the body layer 251 and the width in the Z direction of the support surface 2521 located in the accommodation space S may be the same. In this case, since the side surface 2512 of the phosphor layer 251 is in contact with the second optical member 255 and the third optical member 256, the fluorescence YL emitted from the side surface 2512 is emitted from the second optical member 255 and the third optical member. It is reflected at 256 back into the phosphor layer 251 .

In addition, although the projector 1 including the three light modulators 4R, 4G, and 4B has been illustrated in the above embodiment and modified example, it is also possible to apply the present invention to a projector that displays a color image with one light modulator. Further, the light modulation device is not limited to the liquid crystal panel described above, and a digital mirror device, for example, can be used.

Further, in the above-described embodiment and modification, an example in which the light source device according to the present invention is applied to a projector has been shown, but the present invention is not limited to this. The light source device according to the present invention can also be applied to lighting fixtures such as automobile headlights.

A light source device according to an aspect of the present invention may have the following configuration.
A light source device according to one aspect of the present invention includes a light source that emits light in a first wavelength band; a first optical element that reflects another part of the light of the first wavelength band, and one of the part of the light in the first wavelength band and the other part of the light in the first wavelength band is incident; A wavelength conversion element that wavelength-converts light and emits at least light in a second wavelength band different from the first wavelength band, part of the light in the first wavelength band and another part of the light in the first wavelength band The other is incident on the diffusion element that diffuses the light in the first wavelength band, the light in the second wavelength band that is emitted from the wavelength conversion element, and the light in the first wavelength band that is emitted from the diffusion element and a second optical element for synthesizing, wherein the wavelength conversion element has a light incident surface and wavelength-converts light in the first wavelength band incident on the light incident surface to generate light in the second wavelength band. a conversion layer, a substrate having a support surface supporting the wavelength conversion layer, and a first optical layer that transmits light in a first wavelength band and reflects light in a second wavelength band, the first optical layer supporting the It has a first optical member arranged to face the surface and a second optical layer that reflects at least light in a second wavelength band, and the second optical layer intersects the supporting surface and the first optical layer. and a third optical layer that reflects at least light in a second wavelength band, the third optical layer intersecting the support surface and the first optical layer, and the second optical layer The area of the light incident surface of the wavelength conversion layer having a third optical member arranged to face each other and an opening formed by the substrate, the first optical member, the second optical member, and the third optical member is larger than the area of the light incident region where the light of the first wavelength band is incident on the light incident surface, the area of the light incident region is larger than the area of the opening, and the light of the second wavelength band is emitted from the opening injected.

In one aspect of the light source device of the present invention, the first optical element can vary the ratio of the amount of transmitted light in the first wavelength band and the amount of reflected light in the first wavelength band to the light in the first wavelength band. may be configured.

In one aspect of the light source device of the present invention, the first optical element has a plurality of optical members with different ratios, and the plurality of optical members has a It is good also as a structure which can be replaced.

In one aspect of the light source device of the present invention, the first optical element includes an optical substrate including a plurality of light incident areas with different ratios, and a driving section, and the optical substrate includes a first light emitted from the light source. Light of one wavelength band may be provided so as to be incident on at least one of the plurality of light incidence regions, and the driving section may rotate the optical substrate to switch between the plurality of light incidence regions. .

In one aspect of the light source device of the present invention, the first optical element may include a translucent substrate and a dielectric multilayer film provided on the translucent substrate.

In the light source device according to one aspect of the present invention, the second optical element is a dichroic mirror that transmits light in the second wavelength band and reflects light in the first wavelength band, or a dichroic mirror that reflects light in the second wavelength band. , may include a dichroic mirror that transmits light in the first wavelength band.

In one aspect of the light source device of the present invention, the first optical element directs light in the first wavelength band incident from the light source to a first plane along a virtual plane on which the light source, the first optical element, and the second optical element are arranged. and a second direction orthogonal to the first direction and along a virtual plane, and the diffusing element reflects in the first direction incident light that has been branched in the second direction from the first optical element, and has a wavelength of The conversion element may be configured to convert the wavelength of the light branched from the first optical element and incident in the first direction, and emit the light in the second wavelength band in the second direction.

In the light source device according to one aspect of the present invention, the second optical element reflects, in the second direction, part of the light in the first wavelength band that is emitted in the first direction from the diffusion element and enters the wavelength conversion element. A configuration may also be adopted in which the light in the second wavelength band that is emitted from and is incident in the second direction is transmitted in the second direction and synthesized.

In one aspect of the light source device of the present invention, the first optical element directs light in the first wavelength band incident from the light source to a first plane along a virtual plane on which the light source, the first optical element, and the second optical element are arranged. and a second direction orthogonal to the first direction and along a virtual plane, and the diffusing element reflects the incident light, which is branched in the first direction from the first optical element, in the second direction, and the wavelength The conversion element may be configured to wavelength-convert light that is branched from the first optical element and incident in the second direction, and emit light in the second wavelength band in the first direction.

In the light source device according to one aspect of the present invention, the second optical element transmits, in the second direction, part of the light in the first wavelength band emitted from the diffusion element and incident in the second direction, and converts the wavelength. A configuration may be adopted in which the light in the second wavelength band that is emitted from the element and is incident in the first direction is reflected in the first direction and synthesized.

In one aspect of the light source device of the present invention, the first optical element directs light in the first wavelength band incident from the light source to a first plane along a virtual plane on which the light source, the first optical element, and the second optical element are arranged. and a second direction perpendicular to the first direction and along a virtual plane, the mirror reflecting the incident light in the first direction after being branched in the second direction from the first optical element, and diffusing the light. The element transmits, in the first direction, the light that is incident in the first direction after being reflected from the mirror, and the wavelength conversion element converts the wavelength of the light that is branched from the first optical element and is incident in the first direction. A configuration may be adopted in which light in two wavelength bands is emitted in the second direction.

In the light source device according to one aspect of the present invention, the second optical element reflects, in the second direction, part of the light in the first wavelength band that is emitted in the first direction from the diffusion element and enters the wavelength conversion element. A configuration may also be adopted in which the light in the second wavelength band that is emitted from and is incident in the second direction is transmitted in the second direction and synthesized.

In one aspect of the light source device of the present invention, the first optical element directs light in the first wavelength band incident from the light source to a first plane along a virtual plane on which the light source, the first optical element, and the second optical element are arranged. and a second direction orthogonal to the first direction and along a virtual plane, the mirror reflecting the incident light in the first direction from the first optical element in the second direction, and diffusing the light. The element transmits, in the second direction, the light that is incident in the second direction after being reflected from the mirror, and the wavelength conversion element converts the wavelength of the light that is branched from the first optical element and is incident in the second direction. A configuration may be adopted in which light in two wavelength bands is emitted in the first direction.

In the light source device according to one aspect of the present invention, the second optical element transmits, in the second direction, part of the light in the first wavelength band that is emitted in the second direction from the diffusion element and enters the wavelength conversion element. A configuration may also be adopted in which the light in the second wavelength band emitted from and incident in the first direction is reflected in the first direction and synthesized.

The light source device according to one aspect of the present invention may further include a reflective element that reflects the light in the first wavelength band emitted from the wavelength conversion element and passed through the second optical element.

In one aspect of the light source device of the present invention, the wavelength conversion layer may include a scatterer that scatters light.

In one aspect of the light source device of the present invention, the angle between the plane along the first optical layer and the plane along the light incident surface of the wavelength conversion layer may be 10° or more and 40° or less.

In one aspect of the light source device of the present invention, the second optical layer reflects light in the first wavelength band and light in the second wavelength band, and the third optical layer reflects light in the first wavelength band and light in the second wavelength band. It may be configured to reflect the light of the band.

In one aspect of the light source device of the present invention, the substrate may have a fourth optical layer provided between the support surface and the wavelength conversion layer.

In one aspect of the light source device of the present invention, the fourth optical layer may be provided on at least part of the periphery of the wavelength conversion layer on the support surface.

In one aspect of the light source device of the present invention, the first optical member may be arranged so as not to contact the wavelength conversion layer.

In one aspect of the light source device of the present invention, the wavelength conversion layer may be housed in a housing space provided inside the opening, and an air layer may be provided in the housing space.

A projector according to one aspect of the present invention may have the following configuration.
A projector according to one aspect of the present invention includes the light source device according to the above aspect of the present invention, an optical modulator that modulates light from the light source device according to image information, and a projector that projects the light modulated by the optical modulator. and an optical device.

DESCRIPTION OF SYMBOLS 1... Projector 2, 2A, 2B, 2C, 2D... Light source device 4B, 4G, 4R... Light modulation device 6... Projection optical device 22... Light source 25... Wavelength conversion element 29, 129, 229, 329 First optical element 29a Translucent substrate 29b Half mirror layer (dielectric multilayer film) 30, 130 Second optical element 30b, 130b Dichroic mirror 31, 131 Diffusion element 40 Reflective element 132 Mirror 230 Optical substrate 231 Motor (driving unit) 251 Phosphor layer (wavelength conversion layer) 252 Substrate 253 Fourth optical layer 254 First optical member 255 Second optical member 256 Third optical member 260 Opening 1290, 1291, 1292, 1293 Optical member 2511 Surface (light incident surface) 2521 Supporting surface 2542 First optical layer 2552 Second optical layer 2562 Third optical layer A1 Area (area of surface of phosphor layer) A2 Area (area of excitation light incident region) A3 Area (area of opening) AR Air layer, EL: excitation light (light in first wavelength band), EL1: excitation light (part of light in first wavelength band), EL2: blue light (part of light in first wavelength band), K ... stomata (scatterers), S ... housing space, YL ... fluorescence (light in the second wavelength band).

Claims (23)

a light source that emits light in the first wavelength band;
a first optical element to which light in the first wavelength band is incident, which transmits part of the light in the first wavelength band and reflects another part of the light in the first wavelength band;
Any one of a portion of the light in the first wavelength band and the other portion of the light in the first wavelength band is incident, and the wavelength of the light in the first wavelength band is converted into the first wavelength band. a wavelength conversion element that emits at least light in a second wavelength band different from
a diffusing element for diffusing the light in the first wavelength band to which the other one of the part of the light in the first wavelength band and the other part of the light in the first wavelength band is incident;
a second optical element that synthesizes the light in the second wavelength band emitted from the wavelength conversion element and the light in the first wavelength band emitted from the diffusion element;
The wavelength conversion element is
a wavelength conversion layer that has a light incident surface and converts the wavelength of light in the first wavelength band incident on the light incident surface to generate light in the second wavelength band;
a substrate having a support surface that supports the wavelength conversion layer;
A first optical member having a first optical layer that transmits light in the first wavelength band and reflects light in the second wavelength band, the first optical layer being arranged so as to face the support surface. When,
a second optical member having a second optical layer that reflects at least light in the second wavelength band, the second optical layer being disposed so as to intersect the supporting surface and the first optical layer;
It has a third optical layer that reflects at least light in the second wavelength band, and the third optical layer intersects the support surface and the first optical layer and is arranged to face the second optical layer. a third optical member to be
an opening formed by the substrate, the first optical member, the second optical member and the third optical member;
The area of the light incident surface of the wavelength conversion layer is larger than the area of the light incident region on which the light of the first wavelength band is incident on the light incident surface, and
The area of the light incident surface region is larger than the area of the opening,
Light in the second wavelength band is emitted from the opening. A light source device. 2. The light source according to claim 1, wherein the first optical element is capable of varying a ratio of a transmitted light amount of the light in the first wavelength band and a reflected light amount of the light in the first wavelength band to the light in the first wavelength band. Device. The first optical element has a plurality of optical members with different ratios,
The light source device according to claim 2, wherein the plurality of optical members are interchangeable with respect to the optical path of the light in the first wavelength band emitted from the light source. The first optical element has an optical substrate including a plurality of light incident areas with different ratios, and a driving section,
the optical substrate is provided so that the light in the first wavelength band emitted from the light source is incident on at least one of the plurality of light incident regions;
The light source device according to claim 2, wherein the driving section rotates the optical substrate to switch between the plurality of light incident areas. The light source device according to any one of claims 1 to 4, wherein the first optical element includes a translucent substrate and a dielectric multilayer film provided on the translucent substrate. The second optical element is a dichroic mirror that transmits light in the second wavelength band and reflects light in the first wavelength band, or a dichroic mirror that reflects light in the second wavelength band and reflects light in the first wavelength band. The light source device according to any one of claims 1 to 5, comprising a dichroic mirror that transmits light. The first optical element converts light in a first wavelength band incident from the light source into a first direction along a virtual plane on which the light source, the first optical element and the second optical element are arranged, and the first branching into a second direction perpendicular to the direction and along the virtual plane;
the diffusing element reflects light incident in the second direction after being branched from the first optical element in the first direction;
The wavelength conversion element wavelength-converts the light branched from the first optical element and incident in the first direction, and emits the light in the second wavelength band in the second direction. Item 7. The light source device according to any one of Item 6. The second optical element reflects, in the second direction, part of the light in the first wavelength band that is emitted in the first direction from the diffusion element and is incident thereon, and reflects the light in the second direction from the wavelength conversion element. 8 . The light source device according to claim 7 , wherein the light in the second wavelength band emitted from and incident on the second wavelength band is transmitted in the second direction and synthesized. The first optical element converts light in a first wavelength band incident from the light source into a first direction along a virtual plane on which the light source, the first optical element and the second optical element are arranged, and the first branching into a second direction perpendicular to the direction and along the virtual plane;
the diffusing element reflects light branched from the first optical element in the first direction and incident in the second direction;
The wavelength conversion element wavelength-converts the light branched from the first optical element and incident in the second direction, and emits the light in the second wavelength band in the first direction. Item 7. The light source device according to any one of Item 6. The second optical element transmits, in the second direction, part of the light in the first wavelength band that is emitted from the diffusion element in the second direction and is incident thereon, and transmits the light in the first direction from the wavelength conversion element. 10 . The light source device according to claim 9 , wherein the light in the second wavelength band emitted from and incident on the second wavelength band is reflected in the first direction and synthesized. The first optical element converts light in a first wavelength band incident from the light source into a first direction along a virtual plane on which the light source, the first optical element and the second optical element are arranged, and the first branching into a second direction perpendicular to the direction and along the virtual plane;
further comprising a mirror that reflects the light branched from the first optical element in the second direction and reflected in the first direction;
the diffusing element transmits light incident in the first direction after being reflected from the mirror in the first direction;
The wavelength conversion element wavelength-converts the light branched from the first optical element and incident in the first direction, and emits the light in the second wavelength band in the second direction. Item 7. The light source device according to any one of Item 6. The second optical element reflects in the second direction part of the light in the first wavelength band that is emitted from the diffusion element in the first direction and is incident thereon, and reflects the light in the second direction from the wavelength conversion element. 12 . The light source device according to claim 11 , wherein the light in the second wavelength band emitted from and incident on the second wavelength band is transmitted in the second direction and synthesized. The first optical element converts light in a first wavelength band incident from the light source into a first direction along a virtual plane on which the light source, the first optical element and the second optical element are arranged, and the first branching into a second direction perpendicular to the direction and along the virtual plane;
further comprising a mirror that reflects the light branched from the first optical element and incident in the first direction in the second direction;
the diffusing element transmits, in the second direction, incident light reflected in the second direction from the mirror;
The wavelength conversion element wavelength-converts the light branched from the first optical element and incident in the second direction, and emits the light in the second wavelength band in the first direction. Item 7. The light source device according to any one of Item 6. The second optical element transmits, in the second direction, part of the light in the first wavelength band that is emitted from the diffusion element in the second direction and is incident thereon, and transmits the light in the first direction from the wavelength conversion element. 14 . The light source device according to claim 13 , wherein the light in the second wavelength band emitted from and incident on is reflected in the first direction and synthesized. 15. The light source device according to any one of claims 1 to 14, further comprising a reflecting element that reflects the light in the first wavelength band that is emitted from the wavelength conversion element and has passed through the second optical element. . The light source device according to any one of claims 1 to 15, wherein the wavelength conversion layer includes a scatterer that scatters light. The angle between the plane along the first optical layer and the plane along the light incident surface of the wavelength conversion layer is 10° or more and 40° or less. A light source device as described. the second optical layer reflects light in the first wavelength band and light in the second wavelength band;
The light source device according to any one of claims 1 to 17, wherein the third optical layer reflects light in the first wavelength band and light in the second wavelength band. 19. The light source device according to any one of claims 1 to 18, wherein the substrate has a fourth optical layer provided between the support surface and the wavelength conversion layer. The light source device according to claim 19, wherein the fourth optical layer is provided on at least part of the periphery of the wavelength conversion layer on the support surface. The light source device according to any one of claims 1 to 20, wherein the first optical member is arranged so as not to contact the wavelength conversion layer. The wavelength conversion layer is housed in a housing space provided inside the opening,
The light source device according to any one of claims 1 to 21, wherein an air layer is provided in said housing space. a light source device according to any one of claims 1 to 22;
a light modulating device that modulates light from the light source device according to image information;
and a projection optical device that projects the light modulated by the light modulation device.

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