Light source device and projector

Abstract

To utilize the available capacity of blue light when adjusting the balance between red, green, and blue light, without reducing the luminous energy of the blue light accompanying the luminous energy of the green light.SOLUTION: A light source device comprises: a first light source for emitting first light having a first wavelength; a second light source for emitting second light; a wavelength conversion element that has a first plane which second light emitted from the second light source enters and a second plane that faces the first plane, and which converts the second light to third light having a second wavelength different from that of the first wavelength; an optical member for synthesizing the first light and the third light and emitting the synthesized light; and a reflection member for reflecting the first light emitted from the optical member toward the optical member. The first light reflected by the reflection member enters the second plane of the wavelength conversion element and is converted to the third light.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] Image display devices such as projectors may use a light source device that includes a fluorescence emission source that combines an excitation light source such as a semiconductor laser (Laser Diode; LD) that emits excitation light with a phosphor that converts at least a portion of the excitation light emitted from the excitation light source into fluorescence having a wavelength different from that of the excitation light, and a light emission source that is configured independently of the fluorescence emission source and emits light having a predetermined wavelength.

[0003] For example, Patent Document 1 discloses a device including an excitation light source that emits blue light as excitation light, a phosphor element containing a phosphor for converting at least a part of the excitation light into yellow light, a solid-state light source that emits blue light separate from the excitation light, and an optical system for guiding the excitation light to the phosphor element and mixing the blue light and the converted yellow light to generate white light. The optical system includes a dichroic mirror that reflects the blue light and transmits the yellow light. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2014-507055 Summary of the Invention [Problem to be solved by the invention]

[0005] In the device disclosed in the above-mentioned Patent Document 1, the amount of yellow light emitted from the phosphor tends to be relatively insufficient compared to the blue light emitted from the light source such as an LD, resulting in an excessive blue light emission capacity of the entire device. In such a case, when adjusting the balance between the red light, green light, and blue light, it is necessary to reduce the amount of blue light in accordance with the amount of yellow light, and as a result, there is a risk that the amount of white light emitted from the optical system and the entire device will be lower than the desired amount. In addition, as described above, if the amount of white light is insufficient, there is a risk that the brightness of the image in the projector equipped with the device will decrease. [Means for solving the problem]

[0006] In order to solve the above problems, a light source device according to one embodiment of the present invention includes a first light source that emits a first light having a first wavelength, a second light source that emits a second light, a wavelength conversion element that has a first surface on which the second light emitted from the second light source is incident and a second surface opposite to the first surface and converts the second light into a third light having a second wavelength different from the first wavelength, an optical member that combines the first light and the third light and emits a combined light, and a reflecting member that reflects the first light emitted from the optical member toward the optical member. The first light reflected by the reflecting member is incident on the second surface of the wavelength conversion element via the optical member and is converted into the third light. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a configuration diagram of a projector according to a first embodiment. [Diagram 2] 2 is a configuration diagram of a light source device included in the projector of FIG. 1. [Diagram 3] 3 is a diagram showing a configuration of a wavelength conversion section of the light source device in FIG. 2. [Figure 4] FIG. 11 is a configuration diagram of a light source device according to a second embodiment. [Diagram 5] FIG. 11 is a configuration diagram of a light source device according to a third embodiment. [Figure 6] 6 is a diagram showing a configuration of a wavelength conversion section of the light source device in FIG. 5. [Figure 7] FIG. 13 is a configuration diagram of a light source device according to a fourth embodiment. [Figure 8] FIG. 13 is a configuration diagram of a light source device according to a fifth embodiment. [Figure 9] FIG. 13 is a configuration diagram of a light source device according to a sixth embodiment. [Figure 10] 3 is a diagram showing the results of a simulation of the state in which blue light is collected on the second surface of the wavelength conversion element in the light source device of FIG. 2. FIG. [Figure 11] 8 is a diagram showing the results of a simulation of the state in which blue light is collected on the second surface of the wavelength conversion element in the light source device of FIG. 7. FIG. [Figure 12] 9 is a diagram showing the results of a simulation of the state in which blue light is collected on the second surface of the wavelength conversion element in the light source device of FIG. 8. FIG. [Figure 13] 10 is a diagram showing the results of a simulation of the state in which blue light is collected on the second surface of the wavelength conversion element in the light source device of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] [First embodiment] A first embodiment of the present invention will be described below with reference to FIGS. 1 to 3. FIG. 1 is a schematic diagram showing the configuration of a projector 15 according to a first embodiment. The projector 15 is an image display device that uses a liquid crystal panel as a light modulation device. In the following drawings, the scale of the dimensions of the components may be changed in order to make each component easier to see.

[0009] (projector) 1, the projector 15 includes an illumination device 20, a color separation optical system 200, field lenses 300R, 300G, and 300B, light modulation devices 400R, 400G, and 400B, a cross dichroic prism 500, and a projection optical system 600. The illumination device 20 emits white light (light) WL that is synthesized from red light R, green light G, and blue light B.

[0010] The illumination device 20 includes a light source device 100, a first lens array 70, a second lens array 80, a polarization conversion element 92, and a superimposing lens 94. The light source device 100 emits white light WL. The configuration of the light source device 100 will be described later.

[0011] The white light WL emitted from the light source device 100 is collimated and enters the first lens array 70. The first lens array 70 has a plurality of small lenses 71 for splitting the white light WL emitted from the light source device 100 into a plurality of partial light beams. The plurality of small lenses 71 are arranged in a matrix in a plane perpendicular to the optical axis AX100 of the light source device 100.

[0012] The second lens array 80 has a plurality of small lenses 81 corresponding to the plurality of small lenses 71 of the first lens array 70. The plurality of small lenses 81 are arranged in a matrix in a plane perpendicular to the optical axis AX100. The second lens array 80, together with the superimposing lens 94, forms an image of each of the small lenses 71 of the first lens array 70 in the vicinity of the image forming region of each of the light modulation devices 400R, 400G, and 400B.

[0013] The polarization conversion element 92 has a polarization separation layer, a reflection layer, and a phase difference plate, which are not shown. The polarization conversion element 92 converts the partial light beam emitted from the second lens array 80 into linearly polarized light. The polarization conversion element 92 is formed in a plate shape as a whole. The plate surface of the polarization conversion element 92 is arranged parallel to a plane perpendicular to the optical axis AX100. The polarization separation layer of the polarization conversion element 92 transmits one linearly polarized component of the polarized components contained in the partial light beam emitted from the second lens array 80, and reflects the other linearly polarized component in a direction perpendicular to the optical axis AX100. The reflection layer of the polarization conversion element 92 reflects the other linearly polarized component reflected by the polarization separation layer in a direction parallel to the optical axis AX100. The phase difference plate of the polarization conversion element 92 converts the other linearly polarized component reflected by the reflection layer into one linearly polarized component.

[0014] The superimposing lens 94 collects the partial light beams from the polarization conversion element 92 and superimposes them near the image forming areas of the light modulation devices 400R, 400G, and 400B. The first lens array 70, the second lens array 80, and the superimposing lens 94 constitute an integrator optical system. The integrator optical system makes the in-plane light intensity distribution of the white light WL emitted from the illumination device 20 uniform in the image forming areas of the light modulation devices 400R, 400G, and 400B.

[0015] The color separation optical system 200 includes dichroic mirrors 210 and 220, reflecting mirrors 230, 240 and 250, and relay lenses 260 and 270. The color separation optical system 200 separates the white light WL emitted from the illumination device 20 into red light R, green light G and blue light B, and guides each of the red light R, green light G and blue light B to the light modulation devices 400R, 400G and 400B, respectively.

[0016] Dichroic mirror 210 passes red light R of incident white light WL and reflects green light G and blue light B. Dichroic mirror 220 reflects green light G of incident green light G and blue light B and passes blue light B. Reflecting mirror 230 reflects substantially all of incident red light R. Each of reflecting mirrors 240 and 250 reflects substantially all of incident blue light B.

[0017] Each of the field lenses 300R, 300G, and 300B is disposed between the color separation optical system 200 and each of the light modulation devices 400R, 400G, and 400B on the optical paths of the red light R, green light G, and blue light B. The red light R reflected by the reflecting mirror 230 passes through the field lens 300R and enters the image forming area of ​​the light modulation device 400R. The green light G reflected by the dichroic mirror 220 passes through the field lens 300G and enters the image forming area of ​​the light modulation device 400G. The blue light B reflected by the reflecting mirror 250 passes through the field lens 300B and enters the image forming area of ​​the light modulation device 400B.

[0018] Each of the light modulation devices 400R, 400G, and 400B is composed of a liquid crystal panel that modulates the incident red light R, green light G, and blue light B in accordance with image information to form an image. The operation mode of the liquid crystal panel may be any of TN mode, VA mode, transverse electric field mode, etc., and is not limited to a specific mode. Each of the light modulation devices 400R, 400G, and 400B includes an incident side polarizing plate (not shown) arranged on the light incident surface side, and an exit side polarizing plate (not shown) arranged on the light exit surface side.

[0019] The cross dichroic prism 500 combines the image lights emitted from the light modulation devices 400R, 400G, and 400B to form a color image. The cross dichroic prism 500 is formed in a substantially cubic shape as a whole by gathering and arranging four right-angle prisms so that their apexes overlap each other at a common center position in side view as shown in FIG. 1. A dielectric multilayer film (not shown) is formed on the interface where the right-angle prisms are bonded together in the cross dichroic prism 500. The aforementioned interface is formed in a substantially X-shape in side view.

[0020] The color image emerging from the cross dichroic prism 500 is enlarged and projected by the projection optical system 600 to form an image on the screen SCR.

[0021] (Light source device) Next, the configuration of the light source device 100 of the above-mentioned projector 15 will be described.

[0022] FIG. 2 is a configuration diagram of the light source device 100A of the first embodiment. As shown in FIG. 2, the light source device 100A includes light source units 111, 113, and 115, composite mirrors 122 and 124, and a reflecting mirror 131. In the following description and drawings, the direction parallel to the optical axis AX100 of the white light WL emitted from the light source device 100A is referred to as the Z direction, the side relatively closer to the emission side of the light source device 100A in the Z direction is referred to as the +Z side, and the side relatively opposite to the emission side in the Z direction is referred to as the -Z side. Also, one direction perpendicular to the Z direction is referred to as the X direction, one side relatively in the X direction is referred to as the +X side, and the other side relatively in the X direction is referred to as the -X side. Also, the direction perpendicular to both the X direction and the Z direction is referred to as the Y direction, one side relatively in the Y direction is referred to as the +Y side, and the other side relatively in the Y direction is referred to as the -Y side.

[0023] The light source unit 111 is disposed on the optical axis AX100, and is disposed on the -Z side of the first lens array 70 described with reference to FIG. 1. The light source unit 111 includes a first light source 141 and a pickup optical system 142. The first light source 141 emits blue light (first light) LB1 having a blue wavelength (first wavelength). The first light source 141 includes a solid-state light source such as an LD or a light-emitting diode (LED) formed to be capable of emitting the blue light LB1. The first light source 141 includes, for example, a light-emitting element (not shown) capable of emitting the blue light LB1, and a substrate (not shown) that supports the light-emitting element. The peak wavelength of the blue light LB1 is included in the range of, for example, 440 nm to 480 nm, but is not limited to a specific value as long as it is a wavelength belonging to the blue color of the visible wavelength band. The size of the light emitting area of ​​blue light LB1 in first light source 141 in the XY plane including the X and Y directions, that is, the beam diameter of blue light LB1 immediately after being emitted from first light source 141, is denoted as S1.

[0024] The pickup optical system 142 is disposed on the +Z side of the first light source 141 on the optical axis AX100. The pickup optical system 142 has, for example, a first lens 151, a second lens 152, and a third lens 153. The first lens 151, the second lens 152, and the third lens 153 are disposed in sequence from the -Z side to the +Z side with a gap between them, with their respective axes aligned with the optical axis AX100. The first lens 151 and the second lens 152 are formed, for example, of convex lenses having an incident-side flat surface parallel to the XY plane and an exit-side spherical surface that moves from the outer periphery of the incident-side flat surface toward the axis. The third lens 153 is formed, for example, of a convex lens having an incident-side flat surface parallel to the XY plane and an exit-side aspheric surface that moves from the -Z side to the +Z side toward the axis from the outer periphery of the incident-side flat surface.

[0025] The number, arrangement, and shape of the lenses constituting the pickup optical system 142 are appropriately set in consideration of the possible installation distance in the Z direction of the pickup optical system 142, etc., so as to take in as much of the blue light LB1 emitted with beam diameter S1 from the light emitting region of the first light source 141 as possible, and to expand the blue light LB1 to a desired beam diameter on the +Z side of the pickup optical system 142. The pickup optical system 142 expands the blue light LB1 incident from the first light source 141 into blue light (first light) LB2 having a beam diameter approximately equal to the beam diameter required for the white light WL incident on each image forming region of the optical modulation devices 400R, 400G, and 400B described with reference to FIG. 1, and emits the blue light LB2 to the +Z side along the Z direction.

[0026] The light source unit 113 is disposed on the -X side of the optical path of the blue light LB2 in the X direction, overlaps with the optical path of the blue light LB2 in the Y direction, and is disposed on the +Z side of the light source unit 111 in the Z direction. The light source unit 113 includes a wavelength conversion unit 143 and a pickup optical system 144. The wavelength conversion unit 143 emits green light (third light) LG1.

[0027] 3 is a diagram showing the configuration of the wavelength conversion unit 143 when viewed along the Y direction. As shown in FIG. 3, the wavelength conversion unit 143 includes a second light source 145 that emits blue light (second light) LB11 having a blue wavelength, and a wavelength conversion element 146 that converts the incident blue light including the blue light LB11 into green light LG1. The second light source 145 is formed of a solid-state light source such as an LED formed to be able to emit the blue light LB11, and includes, for example, a substrate 160 and a light-emitting element 161. The substrate 160 has plate surfaces 160a and 160b parallel to a YZ plane including the Y direction and the Z direction, and has a predetermined thickness along the X direction.

[0028] The light emitting element 161 is directly laminated on a plate surface 160a on the +X side of the substrate 160. The light emitting element 161 has an emission surface 161e and a contact surface 161b parallel to the YZ plane, and emits blue light LB11 from the emission surface 161e to the +X side along the X direction. The peak wavelength of the blue light LB11 is, for example, within a range of 440 nm to 480 nm, like the blue light LB1, but is not limited to a specific value as long as it is a wavelength that can excite the wavelength conversion element 146 so that green light LG1 is emitted from the wavelength conversion element 146.

[0029] Abutment surface 161b of light-emitting element 161 abuts against plate surface 160a of substrate 160. The size of the light-emitting region of blue light LB11 in light-emitting element 161 in the YZ plane is smaller than plate surfaces 160a, 160b of substrate 160. The average dimension of light-emitting element 161 of second light source 145 in the YZ plane, that is, the beam diameter of blue light LB11 immediately after being emitted from second light source 145, is denoted as S2.

[0030] The wavelength conversion element 146 is laminated on the emission surface 161e of the light emitting element 161 of the second light source 145. The wavelength conversion element 146 has a first surface 146b on the -X side and a second surface 146a on the +X side, which are parallel to the YZ plane. It is preferable that the first surface 146b of the wavelength conversion element 146 abuts against the emission surface 161e of the light emitting element 161. As an example of an embodiment, if an area Et covers the side surface 161c of the light emitting element 161 and the side surface 146c of the wavelength conversion element 146 from the outside in the YZ plane, the wavelength conversion element 146 may extend to the area Et, and the end surface Eb of the wavelength conversion element 146 on the most -X side and the plate surface 160a of the substrate 160 may be bonded by a photocurable resin or adhesive for sealing. As another example of an embodiment, a photocurable resin or any sealing material for sealing may be disposed in the area Et. In any embodiment, the first surface 146b of the wavelength conversion element 146 and the emission surface 161e of the light emitting element 161 come into contact with each other without any air layer therebetween.

[0031] It is preferable that at least an air layer, or a layer having a large refractive index difference between the light-emitting element 161 and the wavelength conversion element 146 and causing a loss of the blue light LB11 emitted by the light-emitting element 161 is not interposed between the emission surface 161e of the light-emitting element 161 and the first surface 146b of the wavelength conversion element 146 in the X direction.

[0032] A cover member (not shown) formed in a plate shape, for example, of optical glass or the like, may be provided on the +X side of the emission surface 161e of the light emitting element 161 in contact with the emission surface 161e. In this case, the light emitting element 161 and the wavelength conversion element 146 are adjacent to each other in the X direction via the cover member. The surface on the +X side of the cover member contacts the first surface 146b of the wavelength conversion element 146.

[0033] The blue light LB11 emitted from the light emitting element 161 of the second light source 145 enters the wavelength conversion element 146 from the first surface 146b. The second surface 146a is located on the +X side of the first surface 146b. As described later, blue light LB7, which is a part (at least a part) of the blue light LB1 emitted from the first light source 141, enters the wavelength conversion element 146 from the second surface 146a. The wavelength conversion element 146 converts the blue light LB7, LB11 into green light LG1 by generating fluorescent green light LG1 using the incident blue light LB7, LB11 as excitation light. The green light LG1 has a green wavelength (second wavelength). The green wavelength is, for example, within a range of 500 nm to 570 nm, but is not limited to a specific value as long as it is a wavelength belonging to green in the visible wavelength band.

[0034] The material of the wavelength conversion element 146 is, for example, Lu3Al5O 12 :Ce 3+ Phosphor, Y3O4:Eu 2+ Phosphor, (Ba,Sr)2SiO4:Eu 2+ Ba3Si6O phosphor 12 N2:Eu 2+ System phosphors and (Si,Al)6(O,N)8:Eu 2+ However, the material of the wavelength conversion element 146 is not limited to a specific material as long as it is a material that can convert the blue light LB7, LB11 into green light LG1 having a desired green wavelength.

[0035] The size of the wavelength conversion element 146 in the YZ plane is equivalent to that of the light emitting element 161 of the second light source 145, and is smaller than that of the substrate 160. The average dimension of the light emitting region of the green light LG1 in the wavelength conversion element 146 in the YZ plane, i.e., the beam diameter of the green light LG1 immediately after being emitted from the wavelength conversion element 146, is defined as S3. The beam diameter S3 of the green light LG1 is preferably equal to or smaller than twice the beam diameter S1 of the blue light LB1, and more preferably equal to the beam diameter S1.

[0036] As shown in FIG. 2, the pickup optical system 144 is disposed between the optical path of the blue light LB2 and the wavelength conversion element 146 of the light source unit 113 in the X direction, and is disposed on the +X side of the second light source 145 and the wavelength conversion element 146. The pickup optical system 144 has, for example, a first lens 154, a second lens 155, and a third lens 156. The first lens 154 has, for example, a flat surface on the entrance side parallel to the YZ plane and a spherical surface on the exit side that moves to the +X side from the outer periphery of the flat surface on the entrance side toward the axis, and is configured as a convex lens similar to the first lens 151 of the pickup optical system 142. The second lens 155 has, for example, a flat surface on the entrance side parallel to the YZ plane and a spherical surface on the exit side that moves from the -X side to the +X side from the outer periphery of the flat surface on the entrance side toward the axis, and is configured as a convex lens similar to the second lens 152 of the pickup optical system 142. The third lens 156 has, for example, a flat surface on the entrance side parallel to the YZ plane and an aspheric surface on the exit side that moves toward the +X side from the outer edge of the flat surface on the entrance side toward the axis, and is composed of a convex lens like the third lens 153 of the pickup optical system 142.

[0037] The number, arrangement, and shape of the lenses constituting the pickup optical system 144 are appropriately selected in consideration of the possible installation distance in the X direction of the pickup optical system 144, etc., so as to take in as much of the green light LG1 emitted from the wavelength conversion element 146 with the beam diameter S3 as possible and to expand the green light LG1 to a desired beam diameter on the +X side of the pickup optical system 144. The pickup optical system 144 expands the green light LG1 incident from the wavelength conversion element 146 into green light (second light) LG2 having a beam diameter substantially equal to that of the blue light LB2, and emits the green light LG2 to the +X side along the X direction.

[0038] The light source unit 115 is disposed on the -X side of the optical path of the blue light LB2 in the X direction and substantially overlaps with the light source unit 113, overlaps with the optical path of the blue light LB2 in the Y direction, and is disposed on the +Z side of the light source unit 113 in the Z direction. The light source unit 115 includes a third light source 147 and a pickup optical system 148. The third light source 147 emits red light LR1 having a red wavelength. The third light source 147 includes a solid-state light source such as an LD or an LED formed to be able to emit the red light LR1. The third light source 147 includes, for example, a light-emitting element (not shown) capable of emitting the red light LR1, and a substrate (not shown) supporting the light-emitting element. The peak wavelength of the red light LR1 is included in the range of, for example, 600 nm to 800 nm, but is not limited to a specific value as long as it is a wavelength belonging to the red color of the visible wavelength band.

[0039] Let S5 be the average dimension in the YZ plane of the light emitting area of ​​the red light LR1 in the third light source 147, i.e., the beam diameter of the red light LR1 immediately after being emitted from the third light source 147. It is preferable that the beam diameter S5 of the red light LR1 is equal to the beam diameter S1 of the blue light LB1.

[0040] The pickup optical system 148 is disposed between the optical path of the blue light LB2 and the light source unit 115 in the X direction, and is disposed on the +X side of the third light source 147. The pickup optical system 148 has, for example, a first lens 157, a second lens 158, and a third lens 159. The first lens 157 is configured as a convex lens having a flat surface on the incident side and a spherical surface on the exit side, similar to the first lens 154 of the pickup optical system 144. The second lens 158 is configured as a convex lens having a flat surface on the incident side and a spherical surface on the exit side, similar to the second lens 155 of the pickup optical system 144. The third lens 159 is configured as a convex lens having a flat surface on the incident side and an aspheric surface on the exit side, similar to the third lens 156 of the pickup optical system 144.

[0041] The number, arrangement and shape of the lenses constituting the pickup optical system 148 are appropriately selected in consideration of the possible installation distance in the X direction of the pickup optical system 148, etc., so as to take in as much of the red light LR1 emitted from the third light source 147 with the beam diameter S5 as possible and to expand the red light LR1 to a desired beam diameter on the +X side of the pickup optical system 148. The pickup optical system 148 expands the red light LR1 incident from the third light source 147 into red light LR2 having approximately the same beam diameter as the blue light LB2, and emits the red light LR2 to the +X side along the X direction.

[0042] The synthesis mirror (optical member) 122 is disposed in an area where the optical path of the blue light LB2 emitted from the pickup optical system 142 of the light source unit 111 and the optical path of the green light LG2 emitted from the pickup optical system 144 of the light source unit 113 join together. The synthesis mirror 122 is formed in a plate shape and has a first reflecting surface 171 and a second reflecting surface 172 opposite to the first reflecting surface 171. The first reflecting surface 171 and the second reflecting surface 172 are disposed parallel to each other. The second reflecting surface 172 is located on the +Z side of the first reflecting surface 171. The first reflecting surface 171 and the second reflecting surface 172 move from the -Z side to the +Z side as they proceed from the end on the -X side to the +X side, and are disposed parallel to the Y direction, making an angle of approximately 45° with respect to each of the X direction and the Z direction.

[0043] The first reflecting surface 171 reflects a part of the blue light LB2 incident from the -Z side along the Z direction to the +X side along the X direction as blue light (first light) LB3. As described above, the first reflecting surface 171 transmits at least a part (another part) of the remaining part of the incident blue light LB2 to the +Z side along the Z direction. The blue light LB2 transmitted through the first reflecting surface 171 is refracted by the synthesis mirror 122 and is emitted from the second reflecting surface 172 to the +Z side along the Z direction as blue light LB4. For example, if the amount of incident blue light LB2 is 100%, the amount of blue light LB3 emitted from the first reflecting surface 171 to the +X side is appropriately adjusted within a range of about 20% to 50%.

[0044] The second reflecting surface 172 reflects the green light LG2 incident from the -X side along the X direction to the +Z side along the Z direction as green light LG3. For example, if the amount of incident green light LG2 is 100%, the amount of green light LG3 emitted from the second reflecting surface 172 is appropriately adjusted within a range of about 50% to 95%.

[0045] The blue light LB4 and the green light LG3 emitted from the second reflecting surface 172 to the +Z side along the Z direction are combined while being emitted from the second reflecting surface 172, and cyan light (combined light) LC1 is generated. That is, the combining mirror 122 combines the blue light (first light) LB4 that is a part of the blue light LB1 emitted from the first light source 141 with the green light (third light) LG3 that is at least a part of the green light LG1 emitted from the wavelength conversion element 146, and emits the cyan light LC1 to the +Z side along the Z direction.

[0046] The composite mirror 122 has, for example, a first mirror substrate (not shown), a first dielectric multilayer film (not shown) forming the first reflecting surface 171, and a second dielectric multilayer film (not shown) forming the second reflecting surface 172. As described above, the first mirror substrate is disposed at an angle of approximately 45° with respect to each of the X direction and the Z direction, and parallel to the Y direction. The first mirror substrate is formed of a material capable of transmitting at least blue light, for example, optical glass that transmits light in the visible wavelength range. The first dielectric multilayer film is laminated by a manufacturing method such as deposition on the plate surface of the first mirror substrate facing the light source unit 111. The first dielectric multilayer film is designed in consideration of the peak wavelength of the blue light LB2, etc., so as to reflect a part of the incident blue light LB2 as blue light LB3 and transmit at least a part of the remaining part, as described above. The second dielectric multilayer film is laminated by a manufacturing method such as deposition on the plate surface of the first mirror substrate facing the light source unit 113. The second dielectric multilayer film is designed in consideration of the peak wavelength of the green light LG2, etc., so as to reflect the incident green light LG2 as green light LG3 and to reflect green light and red light including the green light LG2, i.e., to reflect yellow light, as described above. Note that the second dielectric multilayer film of the first embodiment only needs to be configured to reflect at least the incident green light LG2 as green light LG3 and to transmit light having wavelengths of colors other than green, and may be designed specifically for green light.

[0047] The combining mirror 124 is disposed within a region where the optical path of the cyan light LC1 emitted from the combining mirror 122 and the optical path of the red light LR2 emitted from the pickup optical system 148 of the light source unit 115 join together. The combining mirror 124 is formed in a plate shape and has a third reflecting surface 173. The third reflecting surface 173 moves from the -Z side to the +Z side as it proceeds from the -X side end to the +X side, forms an angle of approximately 45° with respect to each of the X direction and the Z direction, and is disposed parallel to the Y direction.

[0048] The third reflecting surface 173 reflects the red light LR2 incident from the -X side along the X direction to the +Z side along the Z direction as red light LR3. For example, if the amount of incident red light LR2 is 100%, the amount of red light LR3 emitted from the third reflecting surface 173 is appropriately adjusted within a range of about 50% to 95%.

[0049] Cyan light LC1 incident on the combining mirror 124 from the -Z side passes through the combining mirror 124 and is emitted to the +Z side along the Z direction as cyan light LC2. The cyan light LC2 and red light LR3 emitted from the third reflecting surface 173 to the +Z side along the Z direction are emitted from the third reflecting surface 173 and combined to generate white light (combined light) WL. That is, the combining mirror 124 combines the blue light LB4, the green light (third light) LG3, and the red light LR3 that is at least a part of the red light LR1 emitted from the third light source 147, and emits the white light WL to the +Z side along the Z direction.

[0050] The composite mirror 124 has, for example, a second mirror substrate (not shown) and a third dielectric multilayer film (not shown) forming the third reflection surface 173. As described above, the second mirror substrate is disposed at an angle of approximately 45° with respect to each of the X direction and the Z direction, and parallel to the Y direction. The second mirror substrate is formed of a material capable of transmitting at least blue light and green light, and is formed of, for example, optical glass or the like that transmits light in the visible wavelength band, similar to the first mirror substrate. The third dielectric multilayer film is laminated on the plate surface of the second mirror substrate facing the light source unit 115. The third dielectric multilayer film is designed in consideration of the peak wavelength of the red light LR2, etc., so as to reflect the incident red light LR2 as red light LR3 and transmit light having a wavelength of a color other than red, as described above.

[0051] The reflecting mirror 131 is provided on the optical path of the blue light LB3 reflected by the first reflecting surface 171 of the combining mirror 122, and is disposed on the +X side of the combining mirror 122 in the X direction, and is disposed in a region overlapping with the combining mirror 122 in the Y direction and the Z direction. The reflecting mirror 131 is formed in a plate shape, and has a fourth reflecting surface 174. The fourth reflecting surface 174 is disposed parallel to the YZ plane.

[0052] The fourth reflecting surface 174 reflects the blue light LB3 incident from the -X side along the X direction as blue light (first light) LB5 toward the -X side along the X direction. The reflectance of the blue light on the fourth reflecting surface 174 is preferably, for example, 80% or more, and is adjusted appropriately. The configuration of the reflecting mirror 131 is not particularly limited as long as it has the fourth reflecting surface 174 and can reflect the blue light LB3 as described above. For example, a total reflection mirror for blue light or a total reflection mirror for light in the visible wavelength band is used as the reflecting mirror 131.

[0053] In light source device 100A in which the above-mentioned components are arranged, at least a part of blue light LB2 emitted from light source unit 111 is split into blue light LB3 and blue light LB4 by synthesis mirror 122. Blue light LB5 reflected by reflection mirror 131 passes through synthesis mirror 122 and is emitted from second reflection surface 172 to the -X side along the X direction as blue light LB6. Blue light LB6 passes through pickup optical system 144, is emitted as blue light LB7, and is condensed and incident on wavelength conversion element 146 of light source unit 113 from the +X side. The beam diameter of blue light LB7 on second surface 146a of wavelength conversion element 146 is reduced by pickup optical system 144 to be smaller than the beam diameter of blue light LB6.

[0054] As shown in FIG. 3, in the light source unit 113, blue light LB11 emitted from the second light source 145 is irradiated from the −X side to the first surface 146b and enters the wavelength conversion element 146. In addition, blue light LB7 emitted from the pickup optical system 144 while being condensed on the −X side along the X direction is irradiated from the +X side to the second surface 146a and enters the wavelength conversion element 146. That is, the blue light LB7 is an excitation light originating from the first light source 141 that reaches the second surface 146a through a path via the synthesis mirror 122. The blue light LB11 is an original excitation light originating from the second light source 145 that constitutes the wavelength conversion unit 143 together with the wavelength conversion element 146. The wavelength conversion element 146 is excited by the blue light LB11 and blue light LB7 that are incident from both the first surface 146b and the second surface 146a in the X direction.

[0055] As shown in Fig. 2, the blue light LB4 transmitted through the synthesis mirror 122 and the green light LG2 emitted from the wavelength conversion element 146 of the light source unit 113 to the +X side are synthesized by the synthesis mirror 122, and the cyan light LC1 is emitted toward the synthesis mirror 124 on the +Z side. The cyan light LC1 incident on the synthesis mirror 124 and the red light LR2 emitted from the light source unit 115 are synthesized by the synthesis mirror 124, and the white light WL is emitted from the synthesis mirror 124 to the +Z side along the Z direction. In the light source device 100A, an optical element 140 may be disposed in the optical path of the white light WL as shown by the dashed line in Fig. 2. The optical element 140 is an element for adjusting the beam shape and light intensity distribution of the white light WL emitted from the synthesis mirror 122 to a desired shape and distribution and emitting the white light WL toward the first lens array 70 of the illumination device 20 shown in Fig. 1, and may be omitted. The optical element 140 is not particularly limited as long as it is an element that can adjust the beam shape and intensity distribution of the white light WL to a desired shape and distribution as described above, and may be composed of, for example, a diffusion plate, a microlens array, or the like.

[0056] The light intensities of the red light LR3, green light LG3, and blue light LB4 constituting the white light WL are appropriately set in consideration of the color balance required for the white light WL emitted from the light source device 100A. Also, in consideration of the optimal light intensity ratio of the red light LR3, green light LG3, and blue light LB4, the reflectance and transmittance of the first reflecting surface 171 for the blue light LB2, the reflectance of the second reflecting surface 172 for the green light LG2, the reflectance of the third reflecting surface 173 for the red light LR2, and the reflectance of the fourth reflecting surface 174 for the blue light LB3 are appropriately set.

[0057] The light source device 100A of the first embodiment described above includes at least the first light source 141, the second light source 145, the wavelength conversion element 146, the synthesis mirror 122, and the reflection mirror 131. The first light source 141 emits blue light LB1 having a blue wavelength. The second light source 145 emits blue light LB11 that excites the wavelength conversion element 146. The wavelength conversion element 146 has a first surface 146b on which the blue light LB11 emitted from the second light source 145 is incident, and a second surface 146a that is opposite to the first surface 146b in the X direction and faces the first surface 146b. The wavelength conversion element 146 converts the blue light LB11 into green light LG1 having a green wavelength different from the blue wavelength. The synthesis mirror 122 combines the blue light LB4 and the green light LG3 to emit cyan light LC1. The reflecting mirror 131 reflects the blue light LB3 emitted from the combining mirror 122 to the +X side along the X direction, toward the -X side toward the combining mirror 122. The blue light LB5 reflected by the reflecting mirror 131 is incident on the second surface 146a of the wavelength conversion element 146 via the combining mirror 122, and is converted into green light LG1.

[0058] In the light source device 100A of the first embodiment, blue light LB7, which is a part of blue light LB1 emitted from the first light source 141, is used to excite the wavelength conversion element 146, and green light LG1 is generated. According to the light source device 100A of the first embodiment, among the blue light B, green light G, and red light R constituting the white light WL, the green light G, which is emitted from a phosphor and tends to have a shortage in the amount of light compared to the blue light and red light directly emitted from a solid-state light source such as an LD or an LED, can be compensated for by allocating a part of the blue light, which has a surplus in the amount of light, to excite the wavelength conversion element 146 that generates the green light G. Specifically, without making the size of the wavelength conversion element 146 in the YZ plane excessively larger than the size of the light-emitting region of the first light source 141, the excess blue light LB7 of the blue light LB1 directly emitted from the first light source 141 is made incident on the second surface 146a of the wavelength conversion element 146 opposite to the first surface 146b on which the blue light LB11, which is the original excitation light, is incident, so that the wavelength conversion element 146 can be excited from both sides in the X direction. As a result, the light output from the light source device 100A and the efficiency of the light source device 100A can be increased without significantly changing the balance between RGB in the white light WL.

[0059] In light source device 100A of the first embodiment, the optical system that combines blue light and green light to form cyan light is configured by simply adding a reflecting mirror 131 to an optical system that includes light source unit 111 that emits blue light LB2, light source unit 113 that emits green light LG2, and combining mirror 122. Therefore, the impact on the cost and overall size of light source device 100A can be kept to a minimum.

[0060] In addition, in the light source device 100A of the first embodiment, as described above, the blue light LB11 and the blue light LB7 are irradiated onto the wavelength conversion element 146 from both the first surface 146b and the second surface 146a, so that the efficiency of the wavelength conversion element 146 is improved without excessively increasing the second surface 146a of the wavelength conversion element 146 and the beam diameter S3 of the green light LG1 compared to the light emission area of ​​the first light source 141 and the beam diameter S1 of the blue light LB1. The smaller the beam diameter S3 of the green light LG1, the more the amount of green light LG1 that the pickup optical system 144 can take in, and the larger size of the pickup optical system 144 can be suppressed. In other words, the conversion efficiency of the wavelength conversion element 146 can be improved, the amount of green light LG2 can be increased, and the size of the light source unit 113 can be suppressed to the same level as the light source unit 111. According to the light source device 100A of the first embodiment, it is possible to achieve a good balance of blue light, green light, and red light that is better than that of conventional light source devices, while miniaturizing the entire device.

[0061] In light source device 100A of the first embodiment, combining mirror 122 transmits at least a portion of incident blue light LB2 as blue light LB4, and reflects at least a portion of incident green light LG2 as green light LG3 to generate cyan light LC1 that is a combined light of blue light LB4 and green light LG3. Combined mirror 122 reflects the other portion of incident blue light LB2 to reflecting mirror 131 as blue light LB3.

[0062] In light source device 100A of the first embodiment, a part of blue light LB2 from first light source 141 is reflected as blue light LB3 by first reflecting surface 171 of combining mirror 122, and blue light LB6 that is transmitted through combining mirror 122 out of blue light LB5 reflected by reflecting mirror 131 is collected by pickup optical system 144 and irradiated as blue light LB7 onto second surface 146a of wavelength conversion element 146. According to light source device 100A of the first embodiment, using one combining mirror 122, blue light LB2 can be branched into blue light LB3 for irradiating wavelength conversion element 146 to excite wavelength conversion element 146 and blue light LB4 for combining with cyan light LC1. Also, by using one synthesis mirror 122, blue light LB3 is transmitted toward wavelength conversion element 146 as blue light LB6 and LB7, and green light LG2 emitted from wavelength conversion element 146 along the X direction parallel to the optical paths of blue light LB6 and LB7 is merged with the optical path of blue light LB4 to generate cyan light LC1. As a result, it is possible to prevent light source device 100A of the first embodiment from becoming large.

[0063] In the light source device 100A of the first embodiment, the composite mirror 122 is disposed between the wavelength conversion element 146 of the wavelength conversion unit 143 and the reflecting mirror 131 in the X direction (first direction). In the X direction, the wavelength conversion element 146 is disposed on the -X side of the composite mirror 122, and the reflecting mirror 131 is disposed on the +X side of the composite mirror 122. The first light source 141 is disposed at an interval from the composite mirror 122 in the Z direction (second direction) perpendicular to the X direction, and is disposed on the -Z side of the composite mirror 122. The second surface 146a of the wavelength conversion element 146 is disposed on the side of the wavelength conversion element 146 facing the reflecting mirror 131 in the X direction, that is, on the +X side of the wavelength conversion element 146. The second light source 145 of the wavelength conversion unit 143 is disposed on the opposite side of the side of the wavelength conversion element 146 facing the reflecting mirror 131 in the X direction, that is, on the -X side of the wavelength conversion element 146. The second light source 145 overlaps with the wavelength conversion element 146, the reflecting mirror 131, and the combining mirror 122 in the Z direction.

[0064] In the light source device 100A of the first embodiment, in the arrangement of the components described above, the second surface 146a of the wavelength conversion element 146 and the fourth reflection surface 174 of the reflection mirror 131 are arranged parallel to the YZ plane. The first reflection surface 171 of the synthesis mirror 122 is arranged facing the first light source 141 and the reflection mirror 131. The second reflection surface 172 of the synthesis mirror 122 is arranged facing the wavelength conversion element 146 and the emission part of the white light WL. The first reflection surface 171 and the second reflection surface 172 move from the -X side to the +X side as they proceed from the -Z side to the +Z side. With the above-mentioned arrangement configuration, the optical paths of the blue light LB5 to LB7 that are part of the blue light LB1 emitted from the first light source 141, the optical paths of the blue light LB11 and LB7 for exciting the wavelength conversion element 146, and the optical paths of the wavelength-converted green light LG1 and LG2 can be overlapped with each other along the X direction. This makes it possible to reduce the size of the light source device 100A of the first embodiment and the total number of optical elements and optical components, while using the surplus blue light LB7 of the blue light LB1 for synthesizing white light WL to excite the wavelength conversion element 146, thereby achieving high efficiency wavelength conversion.

[0065] In the light source device 100A of the first embodiment, the first surface 146b of the wavelength conversion element 146 and the emission surface (the emission surface from which the second light is emitted from the second light source) 161e of the light emitting element 161 of the second light source 145 are in contact with each other. According to the light source device 100A of the first embodiment, the blue light LB11 emitted from the emission surface 161e of the light emitting element 161 of the second light source 145 can be made to enter the wavelength conversion element 146 from the first surface 146b with high efficiency. This prevents an excessive load from being applied to the blue light LB7 used to ensure the wavelength conversion efficiency of the wavelength conversion element 146, and increases the degree of freedom in setting the reflectance of the first reflection surface 171 and the second reflection surface 172 of the synthesis mirror 122.

[0066] The projector 15 of the first embodiment includes the above-mentioned light source device 100A, light modulation devices 400R, 400G, and 400B that form image light by modulating the light from the light source device 100A in accordance with image information, and a projection optical system 600 that projects the image light. Since the projector 15 of the first embodiment includes the light source device 100A, it is possible to obtain a good color balance of the white light WL, increase the brightness and chromaticity of the image projected on the screen SCR, and achieve a compact size.

[0067] [Second embodiment] Next, a second embodiment of the present invention will be described with reference to FIG. In the second and subsequent embodiments, the same reference numerals are used for configurations common to the higher-level embodiment, and descriptions thereof will be omitted. In the second and subsequent embodiments, the configurations and contents different from the higher-level embodiment will be mainly described.

[0068] Furthermore, unless otherwise specified, the configuration of the projector other than the light source device of each of the second and subsequent embodiments is common to the configuration of projector 15 of the first embodiment.

[0069] Fig. 4 is a configuration diagram of a light source device 100B of the second embodiment. As shown in Fig. 4, similar to the light source device 100A described in the first embodiment, the light source device 100B includes light source units 111, 113, and 115, composite mirrors 122 and 124, and a reflecting mirror 131. However, in the light source device 100B, the arrangement of the light source unit 111 and the arrangement of the light source unit 113 are opposite to those of the light source device 100A.

[0070] That is, the light source unit 111 is disposed at least on the -Z side of the first lens array 70 described with reference to Fig. 1 in the Z direction, and is disposed on the -Z side of the light source unit 115, and overlaps with the synthesis mirror 122 and the reflection mirror 131. The first light source 141 of the light source unit 111 emits blue light LB1 to the +X side along the X direction. The pickup optical system 142 emits blue light LB2 to the +X side along the X direction.

[0071] The light source unit 113 is disposed on the optical axis AX100, and is disposed on the -Z side of the light source unit 111, the synthesis mirror 122, and the reflection mirror 131 in the Z direction. The light source 113 overlaps with the synthesis mirrors 122 and 124 in the X direction. The second light source 145 of the wavelength conversion unit 143 emits blue light LB11 to the +Z side with respect to the Z direction. The wavelength conversion element 146 of the wavelength conversion unit 143 is disposed on the +Z side of the second light source 145. The first surface 146b and the second surface 146a of the wavelength conversion element 146 are disposed parallel to the XY plane including the X direction and the Y direction. The second surface 146a of the wavelength conversion element 146 is disposed on the +Z side of the first surface 146b.

[0072] As described later, blue light LB7, which is a part (at least a part) of the blue light LB1 emitted from the first light source 141, is irradiated to the second surface 146a from the +Z side along the Z direction and is incident on the wavelength conversion element 146 from the second surface 146a. The wavelength conversion element 146 generates green light LG1 using the incident blue light LB7, LB11 as excitation light, thereby converting the wavelength of the blue light LB7, LB11 into green light LG1.

[0073] The synthetic mirror (optical member) 122 has a fifth reflecting surface 175 and a sixth reflecting surface 176 instead of the first reflecting surface 171 and the second reflecting surface 172. The fifth reflecting surface 175 and the sixth reflecting surface 176 move from the -Z side to the +Z side as they proceed from the -X side end to the +X side, and are arranged parallel to the Y direction, making an angle of approximately 45° with respect to each of the X direction and the Z direction. The fifth reflecting surface 175 transmits at least a part of the blue light LB2 incident from the -X side through the sixth reflecting surface 176 along the X direction as blue light LB3, as described below, and reflects at least a part of the blue light LB5 incident from the +X side to the -Z side along the Z direction as blue light LB6. The fifth reflecting surface 175 transmits the green light LG2 incident from the -Z side along the Z direction. The sixth reflecting surface 176 transmits at least a portion of the blue light LB2 incident from the -X side along the X direction, and reflects at least a portion (another portion) of the remainder of the blue light LB2 to the +Z side along the Z direction as blue light LB4.

[0074] The composite mirror 122 has, for example, a first mirror substrate (not shown), a fifth dielectric multilayer film (not shown) forming the fifth reflecting surface 175, and a sixth dielectric multilayer film forming the sixth reflecting film 176. The fifth dielectric multilayer film is laminated by a manufacturing method such as deposition on the plate surface of the first mirror substrate facing the light source unit 113. The fifth dielectric multilayer film is designed in consideration of the peak wavelength of the blue light LB2, etc., so as to transmit at least a part of the incident blue light LB2 as blue light LB3 and reflect at least a part of the incident blue light LB5 to the -Z side along the Z direction, as described above. The sixth dielectric multilayer film is laminated by a manufacturing method such as deposition on the plate surface of the first mirror substrate facing the light source unit 111. The sixth dielectric multilayer film is designed in consideration of the peak wavelength of the blue light LB2, etc., so as to transmit at least a part of the incident blue light LB2 as blue light LB3 and reflect at least a part of the remaining part of the blue light LB2 to the +Z side along the Z direction, as described above. The fifth and sixth dielectric multilayer films are designed in consideration of the peak wavelength of the green light LG2 and the like so as to transmit light having wavelengths of colors other than blue.

[0075] In the light source device 100B in which the above-mentioned components are arranged, at least a part of the blue light LB2 emitted from the light source unit 111 is split into blue light LB3 and blue light LB4 by the synthesis mirror 122. The blue light LB5 emitted from the reflection mirror 131 is reflected by the synthesis mirror 122 and emitted from the fifth reflection surface 175 to the -Z side along the Z direction as blue light LB6. The blue light LB6 passes through the pickup optical system 144, is emitted as blue light LB7, and is incident on the wavelength conversion element 146 of the light source unit 113 from the +Z side. The wavelength conversion element 146 is excited by the blue light LB11 and LB7 incident from the first surface 146b and the second surface 146a, and emits the green light LG1 from the second surface 146a to the +Z side along the Z direction.

[0076] The blue light LB4 reflected by the combining mirror 122 and the green light LG3 emitted from the wavelength conversion element 146 of the light source unit 113 to the +Z side and transmitted through the fifth reflecting surface 175 of the combining mirror 122 are combined at a sixth reflecting surface 176 of the combining mirror 122. Cyan light LC1 is emitted from the sixth reflecting surface 176 of the combining mirror 122 toward the combining mirror 124 on the +Z side. As in the first embodiment, the combining mirror 124 combines the incident cyan light LC1 with the red light LR2 emitted from the light source unit 115, and emits the generated white light WL to the +Z side along the Z direction.

[0077] Taking into consideration the optimal light intensity ratio of red light LR3, green light LG3, and blue light LB4, the reflectance of fifth reflecting surface 175 for blue light LB5 and the transmittance of blue light LB2, the reflectance of sixth reflecting surface 176 for blue light LB2, the reflectance of third reflecting surface 173 for red light LR2, and the reflectance of fourth reflecting surface 174 for blue light LB3 are appropriately set.

[0078] In the light source device 100B of the second embodiment described above, like the light source device 100A of the first embodiment, blue light LB7, which is a part of the blue light LB1 emitted from the first light source 141, is used to excite the wavelength conversion element 146 to generate green light LG1. Therefore, according to the light source device 100B of the second embodiment, among the blue light, green light, and red light constituting the white light WL, the green light, which tends to be insufficient in terms of the amount of light compared to the blue light and red light, can be compensated for by a part of the blue light, which has a surplus of light. As a result, the light output from the light source device 100B can be increased without significantly changing the balance between RGB in the white light WL.

[0079] In light source device 100B of the second embodiment, combining mirror 122 reflects at least a portion of blue light LB4 of incident blue light LB2, and transmits at least a portion of incident green light LG2 as green light LG3 to generate cyan light LC1 that is a combined light of blue light LB4 and green light LG3. Combined mirror 122 transmits the other portion of incident blue light LB2 toward reflecting mirror 131.

[0080] In the second embodiment of the light source device 100B, a portion of the blue light LB2 from the first light source 141 is transmitted through the sixth reflecting surface 176 and the fifth reflecting surface 175 of the composite mirror 122 as blue light LB3, and of the blue light LB5 reflected by the reflecting mirror 131, blue light LB6 reflected by the fifth reflecting surface 175 of the composite mirror 122 is collected by the pickup optical system 144 and irradiated onto the second surface 146a of the wavelength conversion element 146 as blue light LB7.

[0081] According to the light source device 100B of the second embodiment, the blue light LB2 is split into blue light LB3 for irradiating the wavelength conversion element 146 to excite the wavelength conversion element 146 and blue light LB4 for synthesizing the cyan light LC1 using one synthesis mirror 122. In addition, the blue light LB3 is reflected toward the wavelength conversion element 146 as blue light LB6 and LB7 using one synthesis mirror 122, and the green light LG2 emitted from the wavelength conversion element 146 along the Z direction parallel to the optical paths of the blue light LB6 and LB7 is merged with the optical path of the blue light LB4 to generate the cyan light LC1. As a result, it is possible to prevent the light source device 100B of the second embodiment from becoming too large.

[0082] Furthermore, according to the light source device 100B of the second embodiment, similarly to the first embodiment, a lens is not used, but instead, the synthesis mirror 122 and the reflection mirror 131 are used to branch the blue light LB2 emitted from the light source unit 111 into blue light LB6 to be incident on the second surface 146a of the wavelength conversion element 146, and the blue light LB6 is irradiated toward the light source unit 113, thereby suppressing the occurrence of spherical aberration in the blue light LB6.

[0083] Although not shown, the projector of the second embodiment includes the above-mentioned light source device 100B instead of the light source device 100A as the light source device 100 of the projector 15 of the first embodiment. According to the projector of the second embodiment, it is possible to increase the brightness and chromaticity of the image projected onto the screen SCR and to achieve a compact size.

[0084] [Third embodiment] Next, a third embodiment of the present invention will be described with reference to FIG. Fig. 5 is a configuration diagram of a light source device 100G of the third embodiment. As shown in Fig. 5, the light source device 100G of the third embodiment includes light source units 111 and 117, a synthesis mirror 122, and a reflection mirror 131, similar to the light source device 100A of the first embodiment.

[0085] 2, light source device 100G has a light source unit 117 instead of light source unit 113, and does not need to include light source unit 115 and combining mirror 124. Light source unit 117 includes a wavelength conversion unit 181 and a pickup optical system 191. Wavelength conversion unit 181 emits yellow light (third light) LY1.

[0086] Fig. 6 is a diagram showing the configuration of the wavelength conversion unit 181 when viewed along the Y direction. As shown in Fig. 6, the wavelength conversion unit 181 includes a second light source 145 that emits blue light (second light) LB11, and a wavelength conversion element 182 that converts the incident blue light including the blue light LB11 into yellow light LY1. The peak wavelength of the blue light LB11 emitted by the light emitting element 161 of the second light source 145 is, for example, within a range of 440 nm to 480 nm, like the blue light LB1, but is not limited to a specific value as long as it is a wavelength that can excite the wavelength conversion element 182 so that the yellow light LY1 is emitted from the wavelength conversion element 182.

[0087] The wavelength conversion element 182 is laminated on the emission surface 161e of the light emitting element 161 of the second light source 145. The wavelength conversion element 182 has a first surface 182b on the -X side and a second surface 182a on the +X side, which are parallel to the YZ plane. It is preferable that the first surface 182b of the wavelength conversion element 182 abuts against the emission surface 161e of the light emitting element 161. Regarding the example between the light emitting element 161 and the wavelength conversion element 182, the example between the light emitting element 161 and the wavelength conversion element 146 described in the first embodiment and the modified example are considered by replacing the wavelength conversion element 146 with the wavelength conversion element 182. It is preferable that no air layer or a layer that causes loss of blue light LB11 is interposed between the first surface 182b of the wavelength conversion element 182 and the emission surface 161e of the light emitting element 161.

[0088] Blue light LB7, which is a part (at least a part) of the blue light LB1 emitted from the first light source 141, enters the wavelength conversion element 182 from the second surface 182a. The wavelength conversion element 182 uses the incident blue light LB7, LB11 as excitation light to generate yellow light LY1, which is fluorescent light, thereby converting the wavelength of the blue light LB7, LB11 into yellow light LY1. The yellow light LY1 has a yellow wavelength (second wavelength) that includes a green wavelength and a red wavelength. The yellow wavelength is, for example, in the range of 570 nm to 630 nm, but is not limited to a specific value as long as it is a wavelength that belongs to the yellow wavelength band of the visible wavelength band.

[0089] The material of the wavelength conversion element 182 includes, for example, an yttrium-aluminum-garnet (YAG) phosphor. Taking YAG:Ce containing cerium (Ce) as an example of an activator, the material of the wavelength conversion element 182 includes a material obtained by mixing raw material powders containing constituent elements such as Y2O3, Al2O3, and CeO3 and reacting them in a solid state, Y-Al-O amorphous particles obtained by a wet method such as a coprecipitation method or a sol-gel method, and YAG particles obtained by a gas phase method such as a spray drying method, a flame pyrolysis method, and a thermal plasma method. However, the material of the wavelength conversion element 182 is not limited to a specific material as long as it is a material capable of wavelength conversion of blue light LB7 and LB11 into yellow light LY1 having a desired yellow wavelength.

[0090] If the average dimension in the YZ plane of the light-emitting area of ​​the yellow light LY1 in the wavelength conversion element 182, i.e., the beam diameter of the yellow light LY1 immediately after being emitted from the wavelength conversion element 182, is S3, it is preferable that the beam diameter S3 of the yellow light LY1 is less than twice the beam diameter S1 of the blue light LB1, and it is more preferable that it is equal to the beam diameter S1.

[0091] 2, the pickup optical system 191 is disposed between the optical path of the blue light LB2 and the wavelength conversion element 182 of the light source unit 117 in the X direction, and is disposed on the +X side of the second light source 145 and the wavelength conversion element 182. The pickup optical system 191 has, for example, a first lens 194, a second lens 195, and a third lens 196. Each of the first lens 194, the second lens 195, and the third lens 196 is formed of a convex lens, similar to each of the first lens 154, the second lens 155, and the third lens 156 of the pickup optical system 142.

[0092] As in the above-described embodiment, the number, arrangement and shape of the lenses constituting the pickup optical system 191 are appropriately selected in consideration of the distance at which the pickup optical system 191 can be installed in the X direction, etc., so as to take in as much of the yellow light LY1 emitted from the wavelength conversion element 182 with the beam diameter S3 as possible and to expand the yellow light LY1 to a desired beam diameter on the +X side of the pickup optical system 191. The pickup optical system 191 expands the yellow light LY1 incident from the wavelength conversion element 182 into yellow light (second light) LY2 having a beam diameter substantially equal to that of the blue light LB2, and emits the yellow light LY2 to the +X side along the X direction.

[0093] The synthesis mirror (optical member) 122 is disposed in a region where the optical path of the blue light LB2 and the optical path of the yellow light LY2 emitted from the pickup optical system 191 of the light source unit 113 join together. The synthesis mirror 122 is formed in a plate shape, and has a first reflecting surface 171 and a seventh reflecting surface 177 opposite to the first reflecting surface 171. The seventh reflecting surface 177 is located on the +Z side of the first reflecting surface 171. The seventh reflecting surface 177 moves from the -Z side to the +Z side as it proceeds from the -X side end to the +X side, makes an angle of approximately 45° with respect to each of the X direction and the Z direction, and is disposed parallel to the Y direction.

[0094] The seventh reflecting surface 177 reflects the yellow light LY2 incident from the -X side along the X direction to the +Z side along the Z direction as yellow light LY3. For example, if the amount of incident yellow light LY2 is 100%, the amount of yellow light LY3 emitted from the seventh reflecting surface 177 is appropriately adjusted within a range of about 50% to 95%.

[0095] The blue light LB4 and the yellow light LY3 emitted from the seventh reflecting surface 177 to the +Z side along the Z direction are combined while being emitted from the seventh reflecting surface 177, and white light (combined light) WL is generated. That is, the combining mirror 122 combines the blue light (first light) LB4, which is a part of the blue light LB1, with the yellow light (third light) LY3, which is at least a part of the yellow light LY1 emitted from the wavelength conversion element 146, and emits the white light WL to the +Z side along the Z direction.

[0096] The synthesis mirror 122 is similarly configured by the components described in the first embodiment. However, the synthesis mirror 122 includes a seventh dielectric multilayer film (not shown) forming a seventh reflection surface 177, instead of the second dielectric multilayer film (not shown) forming the second reflection surface 172. The seventh dielectric multilayer film is laminated by a manufacturing method such as deposition on the plate surface facing the light source unit 117 of the first mirror substrate, and reflects the incident yellow light LY2 as yellow light LY3 as described above. However, when the second dielectric multilayer film of the synthesis mirror 122 described in the first embodiment is designed not to specialize in green light, but to reflect yellow light including green light LG2 as described above, the synthesis mirror 122 of the light source device 100G may be configured in the same manner as the synthesis mirror 122 of the light source device 100A.

[0097] The behavior and path of the blue light in the light source device 100G are the same as those in the light source device 100A. However, in the light source device 100G, the yellow light LY2 emitted from the pickup optical system 191 of the light source unit 117 is incident on the seventh reflecting surface 177 of the synthesis mirror 122 and is reflected by the seventh reflecting surface 177 to the +Z side along the Z direction. The blue light LB4 transmitted through the synthesis mirror 122 and the yellow light LY3 reflected by the seventh reflecting surface 177 of the synthesis mirror 122 are combined with each other at the point where they are emitted from the seventh reflecting surface 177 to the +Z side. That is, the white light WL is emitted from the seventh reflecting surface 177 of the synthesis mirror 122 toward the first lens array 70 of the lighting device 20 shown in FIG. 1. The synthesis mirror 122 combines the blue light LB4, which is a part of the incident blue light LB2, with the yellow light LY2 emitted from the light source unit 117, and emits the generated white light WL to the +Z side along the Z direction.

[0098] The light source device 100G of the third embodiment described above has a similar configuration to the light source device 100A of the first embodiment, and therefore provides the same effects as the light source device 100A.

[0099] The light source device 100G of the third embodiment is equipped with a light source section 117 that emits yellow light LY1 and LY2, and the functions of the light source section 115 and the composite mirror 124 in the light source device 100A of the first embodiment are consolidated into a light source section 113 and a composite mirror 122, thereby making it possible to achieve even smaller size than the light source device 100A of the first embodiment.

[0100] Although not shown, the projector of the third embodiment includes the above-mentioned light source device 100G instead of the light source device 100A as the light source device 100 of the projector 15 of the first embodiment. According to the projector of the third embodiment, it is possible to increase the brightness and chromaticity of the image projected onto the screen SCR and to achieve a smaller size than the projector of the first embodiment.

[0101] [Fourth embodiment] Next, a fourth embodiment of the present invention will be described with reference to FIG. Fig. 7 is a configuration diagram of a light source device 100C of the fourth embodiment. As shown in Fig. 7, the light source device 100C of the fourth embodiment includes light source units 111, 113, and 115, combining mirrors 122 and 124, and a reflecting mirror 131, similar to the light source device 100A of the first embodiment.

[0102] In light source device 100C, the fourth reflecting surface (reflecting surface) 174 of the reflecting mirror 131 is disposed not parallel to the YZ plane but at an angle θt with respect to the YZ plane. When viewed along the Y direction, the fourth reflecting surface 174 has a planar shape and moves a constant amount from the +X side to the -X side as it proceeds from the -Z side to the +Z side.

[0103] The behavior and paths of the blue light, green light, and red light in light source device 100C are the same as those in light source device 100A. However, in light source device 100C, since fourth reflecting surface 174 of reflecting mirror 131 is inclined at angle θt with respect to the YZ plane, the region where blue light LB5 reflected by reflecting mirror 131 and emitted from fourth reflecting surface 174 enters first reflecting surface 171 moves toward the -Z side more than the region where blue light LB5 enters first reflecting surface 171 in light source device 100A. The amount of movement of the region where blue light LB5 enters first reflecting surface 171 toward the -Z side changes depending on angle θt and the distance in the Z direction between fourth reflecting surface 174 and first reflecting surface 171.

[0104] The light source device 100C and the projector according to the fourth embodiment described above have the same configuration as the light source device 100A and the projector according to the first embodiment, and therefore provide the same effects as the light source device 100A and the projector.

[0105] Furthermore, in light source device 100C of the fourth embodiment, reflection mirror 131 has a fourth reflection surface 174 that reflects blue light (first light) LB3, which is reflected by the synthesis mirror 122 and emitted from first reflection surface 171 to the +X side along the X direction, toward the synthesis mirror 122. The fourth reflection surface 174 is inclined with respect to the YZ plane (plane perpendicular to the optical axis of the first light) perpendicular to the optical axis of the incident blue light LB3.

[0106] In light source devices 100A and 100C, blue light LB5 reflected by reflecting mirror 131 and emitted to the -X side is refracted by first reflecting surface 171 of composite mirror 122, and moves to the +Z side while traveling to the -X side. The amount of movement of blue light LB5 in the Z direction is determined by the refraction angle at first reflecting surface 171, and changes according to the refractive index difference between air and the first mirror substrate of composite mirror 122. Blue light LB5 is refracted again by second reflecting surface 172, and emitted to the -X side. By refracting blue light LB5 at composite mirror 122 in this way, the center of gravity of the focused spot of blue light LB7 on second surface 146a of wavelength conversion element 146 is slightly shifted to the -Z side from the intersection point between the optical axis of blue light LB5 and first reflecting surface 171.

[0107] In the light source device 100C of the fourth embodiment, since the fourth reflecting surface 174 is inclined at an angle θt with respect to the YZ plane as described above, the center of gravity of the focused spot of the blue light LB7 is shifted in the Z direction compared to the light source device 100A of the first embodiment in which the fourth reflecting surface is parallel to the YZ plane, and the illuminance bias of the focused spot of the blue light LB7 changes. According to the light source device 100C of the fourth embodiment, by adjusting the degree of inclination of the fourth reflecting surface 174 with respect to the YZ plane, i.e., the angle θt, it is possible to adjust the position of the center of gravity of the focused spot of the blue light LB7 on the second surface 146a of the wavelength conversion element 146 in the Z direction and adjust the illuminance bias of the blue light LB7 incident on the wavelength conversion element 146. In addition, in the light source device 100C of the fourth embodiment, by tilting the fourth reflecting surface 174 of the reflecting mirror 131 as described above, it is possible to reduce the deviation and spherical aberration between the optical path and optical axis of the blue light LB6 and the optical path and optical axis of the green light LG2 in the thickness direction of the first mirror substrate and the dielectric multilayer film of the composite mirror 122.

[0108] The angle θt is set according to the size of the second surface 146a of the wavelength conversion element 146 in the Y and Z directions, the distance by which the center of gravity of the focused spot of blue light LB7 is adjusted or moved on the second surface 146a, the amount of adjustment of the illuminance bias of the focused spot of blue light LB7, and the separation distance in the X direction between the fourth reflecting surface 174 and the second surface 146a of the wavelength conversion element 146.

[0109] In addition, taking into consideration the shape of the wavelength conversion element 146 on the YZ plane, the fourth reflecting surface 174 may be inclined at an angle θt with respect to the YZ plane and move from the +X side or the -X side to the -X side or the +X side when moving along the Y direction. In this case, by adjusting the angle θt, the position in the Y direction of the center of gravity of the focused spot of the blue light LB7 on the second surface 146a of the wavelength conversion element 146 and the illuminance bias can be adjusted, and the illuminance distribution of the blue light LB7 on the second surface 146a can be optimized.

[0110] In each of the light source device 100B of the second embodiment and the light source device 100G of the third embodiment, the configuration of the light source device 100C of the fourth embodiment may be applied, and the fourth reflecting surface 174 of the reflecting mirror 131 may be arranged to be inclined with respect to the YZ plane. Even with such a configuration, the same effects as those of the light source device 100C of the fourth embodiment can be obtained.

[0111] [Fifth embodiment] Next, a fifth embodiment of the present invention will be described with reference to FIG. Fig. 8 is a configuration diagram of a light source device 100D of the fifth embodiment. As shown in Fig. 8, the light source device 100D of the fifth embodiment includes light source units 111, 113, and 115, combining mirrors 122 and 124, and a reflecting mirror 131, similar to the light source device 100A of the first embodiment.

[0112] In light source device 100D, fourth reflecting surface (reflecting surface) 174 of reflecting mirror 131 is not parallel to the YZ plane, but is curved with a predetermined radius of curvature with respect to the YZ plane. When viewed along the Y direction, fourth reflecting surface 174 moves in a curved manner from -X side to +X side as it proceeds from -Z side to +Z side, and then moves in a curved manner from +X side to -X side. The apex on the +X side of fourth reflecting surface 174 approximately overlaps with the optical axis of the incident blue light LB3.

[0113] The behavior and paths of the blue light, green light, and red light in light source device 100D are the same as those in light source device 100A. However, in light source device 100D, since the fourth reflecting surface 174 of the reflecting mirror 131 is formed into a convex curved shape protruding toward the +X side, the focused spot of blue light LB7 focused on the second surface 146a of the wavelength conversion element 146 is defocused toward the +X side in the X direction. The defocus amount of the focused spot of blue light LB7 changes depending on the radius of curvature of the fourth reflecting surface 174 and the distance between the fourth reflecting surface 174 and the first reflecting surface 171 in the Z direction.

[0114] The light source device 100D and the projector according to the fifth embodiment described above have the same configuration as the light source device 100A and the projector according to the first embodiment, and therefore provide the same effects as the light source device 100A and the projector.

[0115] Furthermore, in light source device 100D of the fifth embodiment, reflection mirror 131 has a fourth reflection surface 174 that reflects blue light (first light) LB3, which is reflected by the synthesis mirror 122 and emitted from first reflection surface 171 to the +X side along the X direction, toward the synthesis mirror 122. The fourth reflection surface 174 has a concave curved shape that is concave on the opposite side to the incident side of blue light LB3, i.e., on the +X side.

[0116] In the light source device 100D of the fifth embodiment, since the fourth reflecting surface 174 has a concave curved surface shape concave toward the +X side with respect to the YZ plane as described above, the defocus of the condensed spot of the blue light LB7 is adjusted compared to the light source device 100A of the first embodiment in which the fourth reflecting surface has a planar shape parallel to the YZ plane, and the illuminance bias of the condensed spot of the blue light LB7 on the second surface 146a of the wavelength conversion element 146 can be reduced. In addition, in the light source device 100D of the fifth embodiment, the amount of blue light LB7 incident on the wavelength conversion element 146 can be increased by reducing the illuminance bias of the condensed spot of the blue light LB7 on the second surface 146a. Furthermore, in the light source device 100D of the fifth embodiment, the deviation between the optical path and optical axis of the blue light LB6 and the optical path and optical axis of the green light LG2 in the thickness direction of the first mirror substrate or the dielectric multilayer film of the synthesis mirror 122 can be reduced. Like the light source device 100C of the fourth embodiment, the light source device 100D of the fifth embodiment uses the reflecting mirror 131 without using a lens, so that the occurrence of spherical aberration in the blue light beams LB5 to LB7 can be suppressed.

[0117] The radius of curvature of the fourth reflecting surface 174 is set according to the size of the second surface 146a of the wavelength conversion element 146 in the Y and Z directions, the spot diameter of the focused spot of the blue light LB7 and the desired defocus amount, and the separation distance between the fourth reflecting surface 174 and the second surface 146a of the wavelength conversion element 146 in the X direction.

[0118] In each of the light source device 100B of the second embodiment and the light source device 100G of the third embodiment, the configuration of the light source device 100D of the fifth embodiment may be applied, and the fourth reflecting surface 174 of the reflecting mirror 131 may have a concave curved shape recessed toward the +X side. Even with such a configuration, the same effects as those of the light source device 100D of the fifth embodiment can be obtained.

[0119] [Sixth embodiment] Next, a sixth embodiment of the present invention will be described with reference to FIG. Fig. 9 is a configuration diagram of a light source device 100E of the sixth embodiment. As shown in Fig. 9, the light source device 100E of the sixth embodiment includes light source units 111, 113, and 115, composite mirrors 122 and 124, and a reflecting mirror 131, similar to the light source device 100C of the fourth embodiment and the light source device 100D of the sixth embodiment.

[0120] In light source device 100E, fourth reflecting surface (reflecting surface) 174 of reflecting mirror 131 is curved with a predetermined radius of curvature, similar to fourth reflecting surface 174 of reflecting mirror 131 of light source device 100D. However, in the sixth embodiment, a surface that passes through the intersection between the optical axis of blue light LB3 incident on fourth reflecting surface 174 and fourth reflecting surface 174 and touches fourth reflecting surface 174 is inclined at an angle θt with respect to the YZ plane, and moves from the +X side to the -X side as it proceeds from the -Z side to the +Z side.

[0121] The behavior and paths of the blue light, green light, and red light in the light source device 100E are the same as those in the light source devices 100C and 100D. However, in the light source device 100E, the fourth reflecting surface 174 of the reflecting mirror 131 has a convex curved shape that is inclined with respect to the YZ plane and protrudes toward the +X side, so that the center of gravity and light intensity distribution of the focused spot of the blue light LB7 focused on the second surface 146a of the wavelength conversion element 146 change, and the focused spot of the blue light LB7 is defocused in the X direction. The degree of change in the center of gravity of the focused spot of the blue light LB7 and the amount of defocus change depending on the radius of curvature and angle θt of the fourth reflecting surface 174, and the distance in the Z direction between the fourth reflecting surface 174 and the first reflecting surface 171.

[0122] The light source device 100E and the projector according to the sixth embodiment described above have the same configuration as the light source device 100A and the projector according to the first embodiment, and therefore provide the same effects as the light source device 100A and the projector.

[0123] In the light source device 100E of the sixth embodiment, the fourth reflecting surface 174 of the reflecting mirror 131 has a concave curved shape that is concave toward the opposite side to the incident side of the blue light LB3, i.e., the +X side, and is generally inclined with respect to the YZ plane. According to the light source device 100E of the sixth embodiment, the center of gravity and the defocus amount of the focused spot of the blue light LB7 can be adjusted synergistically compared to the light source device 100A of the first embodiment in which the fourth reflecting surface has a planar shape parallel to the YZ plane. Therefore, according to the light source device 100E of the sixth embodiment, the illuminance bias of the blue light LB7 on the second surface 146a of the wavelength conversion element 146 can be efficiently reduced by adjusting the radius of curvature of the fourth reflecting surface 174 of one reflecting mirror 131 and the angle θt representing the degree of inclination of the fourth reflecting surface 174 with respect to the YZ plane. According to the light source device 100E of the sixth embodiment, blue light LB7 can be irradiated to a more optimal region within the second surface 146a compared to the light source device 100C of the fourth embodiment and the light source device 100D of the fifth embodiment, and the amount of blue light LB7 incident on the wavelength conversion element 146 can be efficiently increased.

[0124] In light source device 100E of the sixth embodiment, fourth reflecting surface 174 of reflecting mirror 131 has a concave curved shape and is generally inclined with respect to the YZ plane as described above, thereby absorbing spherical aberration and deviation between the optical path and optical axis of blue light LB6 and the optical path and optical axis of green light LG2 in the thickness direction of the first mirror substrate and dielectric multilayer film of composite mirror 122. Also, in light source device 100E of the fifth embodiment, like light source device 100C of the third embodiment and light source device 100D of the fourth embodiment, a reflecting mirror 131 is used without a lens, and therefore spherical aberration in blue light LB5 to LB7 can be suppressed.

[0125] In each of the light source device 100B of the second embodiment and the light source device 100G of the third embodiment, the configuration of the light source device 100E of the sixth embodiment may be applied, and the fourth reflecting surface 174 of the reflecting mirror 131 may be arranged generally tilted with respect to the YZ plane and have a concave curved shape recessed toward the +X side. Even with such a configuration, the same effects as those of the light source device 100E of the sixth embodiment can be obtained.

[0126] (Numerical example) Next, the behavior of the spot light of blue light LB7 in light source devices 100A, 100C, 100D, and 100E and the results of a simulation regarding the above-mentioned operational effects will be described.

[0127] Fig. 10 is a diagram showing the results of a simulation based on a ray tracing method to calculate the light intensity distribution of the focused spot of blue light LB7 irradiated onto the second surface 146a of the wavelength conversion element 146 of the light source device 100A. Fig. 11 is a diagram showing the results of a simulation performed under the same conditions as those used in the simulation of the light source device 100A, except that the fourth reflecting surface 174 is inclined at an angle θt with respect to the YZ plane, to calculate the light intensity distribution of the focused spot of blue light LB7 irradiated onto the second surface 146a of the wavelength conversion element 146 of the light source device 100B.

[0128] Fig. 12 is a diagram showing the result of calculating the light intensity distribution of the focused spot of blue light LB7 irradiated onto the second surface 146a of the wavelength conversion element 146 of the light source device 100C by performing a simulation under the same conditions as those of the simulation of the light source device 100A, except that the fourth reflecting surface 174 has a concave curved shape concave toward the +X side. Fig. 13 is a diagram showing the result of calculating the light intensity distribution of the focused spot of blue light LB7 irradiated onto the second surface 146a of the wavelength conversion element 146 of the light source device 100E by performing a simulation under the same conditions as those of the simulation of the light source device 100A, except that the fourth reflecting surface 174 has a concave curved shape concave toward the +X side and is generally inclined with respect to the YZ plane.

[0129] In this simulation, the target area to be irradiated with the blue light LB7 is the entire second surface 146a of the wavelength conversion element 146, and is set as a rectangular area longer in the Y direction than in the Z direction. The size of the second surface 146a of the wavelength conversion element 146 in the Y direction is 1.55 mm, and the size of the second surface 146a of the wavelength conversion element 146 in the Z direction is 1.2 mm. In each of Figs. 10 to 13, the dimension of the target area in the Y direction is represented as yB, and the dimension of the target area in the Z direction is represented as zB. The dimension yB is larger than the dimension zB. In addition, in each of Figs. 10 to 13, the light intensity profile in the Z direction of the blue light LB7 on the second surface 146a of the wavelength conversion element 146 is represented as a "z-profile", and the light intensity profile in the Y direction of the blue light LB7 on the second surface 146a of the wavelength conversion element 146 is represented as a "y-profile".

[0130] 10 to 13, in the Y direction, the half-width of the light intensity profile of the blue light LB7 on the second surface 146a of the wavelength conversion element 146 was larger in the light source devices 100D and 100E than in the light source devices 100A and 100C. However, in the Y direction, in any of the light source devices 100A, 100C, 100D, and 100E, the light intensity profile of the blue light LB7 spread approximately symmetrically on both the positive and negative sides of the target area with 0 (zero) as the center, and the center of gravity of the focused spot of the blue light LB7 was near 0.

[0131] 10 to 13, in the Z direction, the half-width of the light intensity profile of the blue light LB7 on the second surface 146a of the wavelength conversion element 146 is larger in the light source devices 100A and 100C than in the light source devices 100D and 100E. As shown in Fig. 10, in the case of the light source device 100A, in the Z direction, the negative region side of the light intensity profile of the blue light LB7, i.e., the rise on the -Z side from 0, is steeper than the positive region side of the same profile, i.e., the rise on the +Z side from 0, and it was found that the center of gravity of the focused spot of the blue light LB7 is on the -Z side from 0.

[0132] 11, in the case of light source device 100C, since the fourth reflecting surface 174 is inclined with respect to the YZ plane, the light intensity profile of blue light LB7 in the Z direction is slightly wider than that of light source device 100A, but is maintained substantially the same, and is generally moved to the +Z side. That is, the center of gravity of the focused spot of blue light LB7 in the case of light source device 100C is moved to the +Z side compared to that of light source device 100A, and is close to 0. From this result, it was confirmed that by inclining the fourth reflecting surface 174 with respect to the YZ plane, the center of gravity is finely adjusted in the Z direction without significantly changing the light intensity distribution of the focused spot of blue light LB7, and the illuminance bias of the focused spot of blue light LB7 is reduced.

[0133] As shown in Fig. 12, in the case of light source device 100D, reflection mirror 131 is curved and recessed toward the +X side with respect to the YZ plane, so that blue light LB7 is defocused in the Z direction and the symmetry of the light intensity profile of blue light LB7 is improved compared to light source devices 100A and 100C. As shown in Fig. 13, in the case of light source device 100E, fourth reflection surface 174 is arranged at an angle with respect to the YZ plane and curved and recessed toward the +X side with respect to the YZ plane, so that in the Z direction, symmetry of the light intensity profile of blue light LB7 is obtained similarly to light source device 100D due to the synergistic effect of the curvature and inclination of fourth reflection surface 174, and the half-width of the focused spot of blue light LB7 is reduced compared to light source device 100D, and illuminance bias is reduced.

[0134] Based on the data of the light intensity profiles in the Y and Z directions in each of Figs. 10 to 13, the efficiency of the blue light LB7 on the second surface 146a of the wavelength conversion element 146 for each of the light source devices 100A, 100C, 100D, and 100E, the relative shift amount of the center of gravity of the blue light LB7 with respect to the center 0 in the Z direction, and the relative shift amount of the center of gravity of the blue light LB7 with respect to the center 0 in the Y direction were calculated. The above-mentioned "efficiency" represents the ratio [%] of the light amount of the blue light LB7 incident on the second surface 146a of the wavelength conversion element 146 when the light amount of the blue light LB1 emitted from the first light source 141 of each light source device is set to 100%. Table 1 shows the calculation results of the efficiency of the blue light LB7 on the second surface 146a of the wavelength conversion element 146, the shift amount from the center 0 in the Z direction, and the shift amount from the center 0 in the Y direction for each of the light source devices 100A, 100C, 100D, and 100E.

[0135] [Table 1]

[0136] As shown in Table 1, in light source device 100C, by tilting the fourth reflecting surface 174 with respect to the YZ plane, the position of the center of gravity is fine-tuned in the Z direction without significantly changing the light intensity distribution of the focused spot of blue light LB7 compared to the case of light source device 100A, so that efficiency is obtained at the same level as in the case of light source device 100A, and the deviation from the center 0 in the Z direction and Y direction is suppressed to ±0.01 or less.

[0137] As shown in Table 1, in light source device 100D, by making the shape of fourth reflecting surface 174 a concave curved shape recessed toward the +X side, the symmetry of the light intensity profile of blue light LB7 is improved compared to light source device 100A, and therefore the efficiency is improved. In light source device 100E, by making fourth reflecting surface 174 inclined with respect to the YZ plane and having a concave curved shape recessed toward the +X side, the efficiency is similar to that of light source device 100C, and the deviation from center 0 in the Z direction and Y direction is suppressed to ±0.01 or less.

[0138] From the above simulation results, it was confirmed that in the light source devices 100A, 100C, 100D, and 100E, by tilting the fourth reflecting surface 174 of the reflecting mirror 131 with respect to the YZ plane perpendicular to the optical axis of the incident blue light LB3, it is possible to finely adjust the position of the center of gravity of the focused spot light of the blue light LB7 incident on the second surface 146a of the wavelength conversion element 146, and reduce the illuminance bias of the focused spot light of the blue light LB7. It was also confirmed that in the light source devices 100A, 100C, 100D, and 100E, by forming the fourth reflecting surface 174 of the reflecting mirror 131 into a concave curved surface shape concave toward the +X side, it is possible to increase the symmetry of the light intensity distribution of the focused spot light of the blue light LB7, reduce the illuminance bias of the focused spot light of the blue light LB7, and improve the efficiency.

[0139] As described in the fourth embodiment, the optical axis of the blue light LB5 is refracted by an amount substantially equal to the thickness of the synthesis mirror 122, and is shifted from the optical axis of the green light LG1 emitted by the wavelength conversion element 146 by a dimension corresponding to the thickness of the synthesis mirror 122 in the YZ plane. It is difficult to make the thickness of the synthesis mirror 122 thinner than a predetermined value due to the manufacturing environment and handling during the manufacturing process, and there is a substantial lower limit to the thickness of the synthesis mirror 122. The influence of the illuminance bias caused by the shift amount of the optical axis of the blue light LB7 on the efficiency of the blue light LB7 incident on the wavelength conversion element 146 and the color balance of the white light WL is minor when the size of the optical system of the light source device is large and the shift amount of the optical axis is relatively small with respect to the maximum beam width of the blue light LB7. In such a case, as in the light source device 100A, the fourth reflection surface 174 of the reflection mirror 131 may have a planar shape and be arranged parallel to the YZ plane.

[0140] However, for example, as in the optical system assumed in the above numerical example, when the deviation of the optical axis is relatively large with respect to the maximum beam width of the blue light LB7, the influence of the illuminance bias of the blue light LB7 on the efficiency of the blue light LB7 incident on the wavelength conversion element 146 and the color balance of the white light WL appears to a non-negligible extent. When the deviation of the optical axis is relatively large with respect to the maximum beam width of the blue light LB7 and LB11, it is preferable to adjust the inclination and curvature of the fourth reflecting surface 174 of the reflecting mirror 131 with respect to the YZ plane as in the light source devices 100C, 100D, and 100E, thereby reducing the deviation of the optical axis of the blue light LB7 and suppressing the illuminance bias.

[0141] As described in the first embodiment, in order to capture as much of the blue light LB1 emitted from the first light source 141 of the light source unit 111 as possible with the pickup optical system 142 of a certain size, it is preferable that the beam diameter S1 of the blue light LB1 is small, and accordingly, it is preferable that the size of the light-emitting area of ​​the first light source 141 is also small. Similarly, in order to capture as much of the green light LG1 emitted from the wavelength conversion element 146 of the light source unit 113 with the pickup optical system 144 of a certain size, it is preferable that the size of the light-emitting area of ​​the wavelength conversion element 146, i.e., the size of the second surface 146a, is also small. Therefore, when the light source device 100A is required to be miniaturized in accordance with the miniaturization of the projector 15, it is required to further reduce the light-emitting area of ​​the first light source 141 and the second surface 146a of the wavelength conversion element 146 in order to ensure the amount of light of the white light WL. In that case, it is also considered that the amount of deviation of the optical axis becomes somewhat large with respect to the maximum beam width of the blue light LB7. Therefore, when the projector 15 is made smaller than the conventional projectors, it is preferable to appropriately adopt the configuration of the light source devices 100C, 100D, and 100E, and tilt the fourth reflecting surface 174 of the reflecting mirror 131 with respect to a plane perpendicular to the optical axis of the blue light LB3, or to make the fourth reflecting surface 174 a concave curved surface concave on the side opposite to the incident surface of the blue light LB3. This makes it possible to efficiently reduce the illuminance bias of the blue light LB7 on the second surface 146a of the wavelength conversion element 146, and to increase the amount of blue light LB7 incident on the wavelength conversion element 146 and the amount of green light LG1 emitted from the wavelength conversion element 146.

[0142] Although the preferred embodiment of the present invention has been described in detail above, the present invention is not limited to the specific embodiment, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims. Also, the components of multiple embodiments can be appropriately combined.

[0143] For example, the above-described light source device is applied to a projector, but may also be applied to image display devices other than projectors that require good color balance in white light WL, and to such image display devices and optical systems that require compact size.

[0144] The light source device according to the aspect of the present invention may have the following configuration. One embodiment of the light source device of the present invention includes a first light source that emits a first light having a first wavelength, a second light source that emits a second light, a wavelength conversion element having a first surface onto which the second light emitted from the second light source is incident and a second surface opposite the first surface, and converting the second light into a third light having a second wavelength different from the first wavelength, an optical member that combines the first light and the third light and emits combined light, and a reflecting member that reflects the first light emitted from the optical member toward the optical member, and the first light reflected by the reflecting member is incident on the second surface of the wavelength conversion element via the optical member and is converted into the third light.

[0145] In one embodiment of the light source device of the present invention, the optical element may transmit at least a portion of the incident first light and reflect at least a portion of the incident third light to generate a composite light, and may reflect another portion of the first light to the reflecting element.

[0146] In one embodiment of the light source device of the present invention, the optical element may reflect at least a portion of the incident first light and transmit at least a portion of the incident third light to generate a composite light, and transmit another portion of the first light toward the reflecting element.

[0147] In the light source device according to one aspect of the present invention, the reflecting member may have a reflecting surface that reflects the first light toward the optical member, and the reflecting surface may be inclined with respect to a plane perpendicular to the optical axis of the first light.

[0148] In the light source device according to one aspect of the present invention, the reflecting member may have a reflecting surface that reflects the first light toward the optical member, and the reflecting surface may have a concave curved shape that is concave on the side opposite to the incident side of the first light.

[0149] In one embodiment of the light source device of the present invention, an optical member is arranged between the wavelength conversion element and the reflecting member in a first direction, a first light source is arranged at a distance from the optical member in a second direction perpendicular to the first direction, the second surface is arranged on the side of the wavelength conversion element facing the reflecting member in the first direction, and the second light source is arranged on the opposite side of the wavelength conversion element facing the reflecting member in the first direction, and may overlap the wavelength conversion element, the reflecting member, and the optical member in the first direction.

[0150] In the light source device according to one aspect of the present invention, the first surface of the wavelength conversion element and an emission surface from which the second light is emitted from the second light source may be in contact with each other.

[0151] A projector according to one aspect of the invention may have the following configuration. A projector according to one aspect of the invention includes the above-mentioned light source device, a light modulation device that forms image light by modulating light from the light source device in accordance with image information, and a projection optical system that projects the image light. [Explanation of symbols]

[0152] 15...projector, 20...illumination device, 100, 100A, 100B, 100C, 100D, 100E, 100G...light source device, 141...first light source, 145...second light source, 146...wavelength conversion element, 146a...second surface, 146b...first surface, 122...composite mirror (optical member), 131...reflecting mirror (reflecting member), 400B, 400G, 400R...light modulation device, 600...projection optical system, LB1, LB2, LB4...blue light (first light), LB11...blue light (second light), LG1, LG2, LG3...green light (third light).

Claims

1. a first light source that emits a first light having a first wavelength; A second light source that emits a second light; A first surface on which the second light emitted from the second light source is incident and a second surface facing the first surface a wavefront having two surfaces, the wavefront converting the second light into a third light having a second wavelength different from the first wavelength; A long conversion element; an optical member that combines the first light and the third light and emits a combined light; The part of the first light emitted from the first light source and emitted from the optical member a reflecting member that reflects the first light toward the optical member; Equipped with The first light reflected by the reflecting member is guided through the optical member to the wavelength conversion element is incident on the second surface and converted into the third light, The optical member transmits a part of the first light and transmits the third light. to generate the composite light, and to reflect another part of the first light incident thereon. Reflected by reflective material, Light source device.

2. A first light source that emits a first light having a first wavelength; A second light source that emits a second light; A first surface on which the second light emitted from the second light source is incident and a second surface facing the first surface a wavefront having two surfaces, the wavefront converting the second light into a third light having a second wavelength different from the first wavelength; A long conversion element; an optical member that combines the first light and the third light and emits a combined light; The part of the first light emitted from the first light source and emitted from the optical member a reflecting member that reflects the first light toward the optical member; Equipped with The first light reflected by the reflecting member is guided through the optical member to the wavelength conversion element is incident on the second surface and converted into the third light, the reflecting member has a reflecting surface that reflects the first light toward the optical member, The reflecting surface is inclined with respect to a plane perpendicular to the optical axis of the first light. Light source device.

3. A first light source that emits a first light having a first wavelength; A second light source that emits a second light; A first surface on which the second light emitted from the second light source is incident and a second surface facing the first surface a wavefront having two surfaces, the wavefront converting the second light into a third light having a second wavelength different from the first wavelength; A long conversion element; an optical member that combines the first light and the third light and emits a combined light; The part of the first light emitted from the first light source and emitted from the optical member a reflecting member that reflects the first light toward the optical member; Equipped with The first light reflected by the reflecting member is guided through the optical member to the wavelength conversion element is incident on the second surface and converted into the third light, the reflecting member has a reflecting surface that reflects the first light toward the optical member, The reflecting surface has a concave curved shape that is concave on a side opposite to the incident side of the first light. Light source device.

4. The reflecting surface is inclined with respect to a plane perpendicular to the optical axis of the first light. The light source device according to claim 3 .

5. A first light source that emits a first light having a first wavelength; A second light source that emits a second light; A first surface on which the second light emitted from the second light source is incident and a second surface facing the first surface a wavefront having two surfaces, the wavefront converting the second light into a third light having a second wavelength different from the first wavelength; A long conversion element; an optical member that combines the first light and the third light and emits a combined light; The part of the first light emitted from the first light source and emitted from the optical member a reflecting member that reflects the first light toward the optical member; Equipped with The first light reflected by the reflecting member is guided through the optical member to the wavelength conversion element is incident on the second surface and converted into the third light, The second light source, the wavelength conversion element, the optical member, and the reflecting member are arranged in a straight line. It is placed Light source device.

6. A first light source that emits a first light having a first wavelength; A second light source that emits a second light; A first surface on which the second light emitted from the second light source is incident and a second surface facing the first surface a wavefront having two surfaces, the wavefront converting the second light into a third light having a second wavelength different from the first wavelength; A long conversion element; an optical member that combines the first light and the third light and emits a combined light; The part of the first light emitted from the first light source and emitted from the optical member a reflecting member that reflects the first light toward the optical member; Equipped with The first light reflected by the reflecting member is guided through the optical member to the wavelength conversion element is incident on the second surface and converted into the third light, The optical member is disposed between the wavelength conversion element and the reflecting member in a first direction; The first light source is disposed apart from the optical member in a second direction perpendicular to the first direction. 、 The second surface faces the reflecting member. The second light source is disposed on the opposite side of the wavelength conversion element from the reflecting member side, The wavelength conversion element, the reflecting member, and the optical member are overlapped in the first direction. Light source device.

7. The first surface of the wavelength conversion element and an exit surface through which the second light from the second light source is exited are mutually arranged. It is in contact with The light source device according to claim 1 .

8. A light source device according to any one of claims 1 to 7, A light modulation device that forms image light by modulating light from the light source device in accordance with image information. A tuning device, a projection optical system that projects the image light; Equipped with projector.

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