Light source device and projector

Abstract

A light source device and a projector are provided, which, when adjusting the balance of red, green, and blue light, do not reduce the amount of blue light based on the amount of green light, but effectively utilize the surplus power of blue light. The light source device includes: a first light source emitting first light having a first wavelength; a second light source emitting second light; a wavelength conversion element having a first surface for the second light emitted from the second light source to be incident on and a second surface opposite to the first surface, converting the second light into third light having a second wavelength different from the first wavelength; an optical component that combines the first light and the third light to emit combined light; and a reflective component that reflects the first light emitted from the optical component as part of the first light emitted from the first light source toward the optical component. The first light reflected by the reflective component is incident on the second surface of the wavelength conversion element via the optical component and converted into third light.

Description

Technical Field

[0001] This invention relates to light source devices and projectors. Background Technology

[0002] In image display devices such as projectors, a light source device is sometimes used, which includes: a fluorescent light source, which is composed of an excitation light source such as a semiconductor laser (LD) that emits excitation light and 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 the excitation light; and a light source, which is independently configured from the fluorescent light source and emits light having a predetermined wavelength.

[0003] For example, Patent Document 1 discloses an apparatus comprising: an excitation light source emitting blue light as excitation light; a phosphor element including a phosphor for converting at least a portion of the excitation light into yellow light; a solid-state light source emitting blue light different from the excitation light; and an optical system for guiding the excitation light to the phosphor element, 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 while allowing the yellow light to pass through.

[0004] Patent Document 1: Japanese Patent Publication No. 2014-507055

[0005] In the device disclosed in Patent Document 1, the amount of yellow light emitted from the phosphor is often insufficient compared to the amount of blue light emitted from a light source such as an LD, resulting in an excess of blue light emission capability for the entire device. In such a case, when adjusting the balance between red, green, and blue light, it is necessary to reduce the amount of blue light according to the amount of yellow light. As a result, the amount of white light emitted from the optical system and the entire device may be lower than desired. Furthermore, if the amount of white light is insufficient as described above, the brightness of the image in the projector equipped with the device may decrease. Summary of the Invention

[0006] To address the aforementioned issues, one aspect of the present invention provides a light source device comprising: a first light source emitting first light having a first wavelength; a second light source emitting second light; a wavelength conversion element having a first surface into which the second light emitted from the second light source is incident and a second surface opposite to the first surface, the wavelength conversion element converting the second light into third light having a second wavelength different from the first wavelength; an optical component that combines the first light and the third light to emit combined light; and a reflective component that reflects the first light emitted from the optical component as part of the first light emitted from the first light source toward the optical component, the first light reflected by the reflective component being incident on the second surface of the wavelength conversion element via the optical component and converted into the third light. Attached Figure Description

[0007] Figure 1 This is a structural diagram of the projector according to the first embodiment.

[0008] Figure 2 yes Figure 1 A structural diagram of the light source device in a projector.

[0009] Figure 3 It means Figure 2 A diagram showing the structure of the wavelength conversion section of the light source device.

[0010] Figure 4 This is a structural diagram of the light source device according to the second embodiment.

[0011] Figure 5 This is a structural diagram of the light source device according to the third embodiment.

[0012] Figure 6 It means Figure 5 A diagram showing the structure of the wavelength conversion section of the light source device.

[0013] Figure 7 This is a structural diagram of the light source device according to the fourth embodiment.

[0014] Figure 8 This is a structural diagram of the light source device according to the fifth embodiment.

[0015] Figure 9 This is a structural diagram of the light source device according to the sixth embodiment.

[0016] Figure 10 It means to Figure 2 The figure shows the results of simulating the focusing state of blue light on the second surface of the wavelength conversion element in the light source device.

[0017] Figure 11 It means to Figure 7The figure shows the results of simulating the focusing state of blue light on the second surface of the wavelength conversion element in the light source device.

[0018] Figure 12 It means to Figure 8 The figure shows the results of simulating the focusing state of blue light on the second surface of the wavelength conversion element in the light source device.

[0019] Figure 13 It means to Figure 9 The figure shows the results of simulating the focusing state of blue light on the second surface of the wavelength conversion element in the light source device.

[0020] Label Explanation

[0021] 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 component); 131: Mirror (reflective component); 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). Detailed Implementation

[0022] [First Implementation]

[0023] The following uses Figures 1 to 3 The first embodiment of the present invention will be described.

[0024] Figure 1 This is a schematic diagram showing the structure of the projector 15 according to the first embodiment. The projector 15 is an image display device that uses a liquid crystal panel as a light modulation device. In the following figures, the scale of the dimensions is sometimes changed according to the structural elements in order to facilitate observation of each structural element.

[0025] (Projector)

[0026] like Figure 1 As shown, 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-shaped dichroic prism 500, and a projection optical system 600. The illumination device 20 emits white light (light) WL, which is a composite of red light R, green light G, and blue light B.

[0027] 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 superimposed lens 94. The light source device 100 emits white light WL. The structure of the light source device 100 will be described later.

[0028] The white light WL emitted from the light source device 100 is parallelized and incident on 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 multiple partial beams. The plurality of small lenses 71 are arranged in a matrix in a plane orthogonal to the optical axis AX100 of the light source device 100.

[0029] 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 orthogonal to the optical axis AX100. Together with the overlapping lens 94, the second lens array 80 enables the images of each small lens 71 of the first lens array 70 to be imaged near the respective image forming areas of the optical modulation devices 400R, 400G, and 400B.

[0030] The polarization conversion element 92 has a polarization separation layer (not shown), a reflective layer, and a phase retardation plate. The polarization conversion element 92 converts a portion of the light beam emitted from the second lens array 80 into linearly polarized light. The polarization conversion element 92 is integrally formed in a plate shape. The plate surface of the polarization conversion element 92 is arranged parallel to a plane orthogonal to the optical axis AX100. The polarization separation layer of the polarization conversion element 92 allows the linearly polarized component of one polarization element contained in the portion of the light beam emitted from the second lens array 80 to pass through, and reflects the other linearly polarized component in a direction orthogonal to the optical axis AX100. The reflective 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 retardation plate of the polarization conversion element 92 converts the other linearly polarized component reflected by the reflective layer into a linearly polarized component of one polarization element.

[0031] The overlapping lens 94 focuses the light beams from the polarization conversion element 92 and overlaps them near the image forming areas of the optical modulation devices 400R, 400G, and 400B. The first lens array 70, the second lens array 80, and the overlapping lens 94 constitute an integrator optical system. The integrator optical system ensures that the in-plane light intensity distribution of the white light WL emitted from the illumination device 20 is uniform within the image forming areas of the optical modulation devices 400R, 400G, and 400B.

[0032] The color separation optical system 200 includes dichroic mirrors 210 and 220, reflectors 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 the red light R, green light G, and blue light B to the light modulation devices 400R, 400G, and 400B, respectively.

[0033] Dichroic mirror 210 allows red light R from the incident white light WL to pass through, while reflecting green light G and blue light B. Dichroic mirror 220 reflects green light G from the incident green light G and blue light B, allowing blue light B to pass through. Mirror 230 reflects almost all of the incident red light R. Mirrors 240 and 250 reflect almost all of the incident blue light B, respectively.

[0034] Field lenses 300R, 300G, and 300B are respectively positioned between the color separation optical system 200 and the light modulation devices 400R, 400G, and 400B in the respective optical paths of red light R, green light G, and blue light B. Red light R, reflected by mirror 230, passes through field lens 300R and enters the image forming area of ​​light modulation device 400R. Green light G, reflected by dichroic mirror 220, passes through field lens 300G and enters the image forming area of ​​light modulation device 400G. Blue light B, reflected by mirror 250, passes through field lens 300B and enters the image forming area of ​​light modulation device 400B.

[0035] The light modulation devices 400R, 400G, and 400B are each composed of a liquid crystal panel that modulates the incident red light R, green light G, and blue light B according to image information to form an image. The operating mode of the liquid crystal panel can be any of TN mode, VA mode, lateral electric field mode, etc., and is not limited to a specific mode. The light modulation devices 400R, 400G, and 400B each have an incident-side polarizer (not shown) disposed on the light incident surface side and an exit-side polarizer (not shown) disposed on the light exiting surface side.

[0036] A cross-shaped dichroic prism 500 combines the image light emitted from each of the optical modulation devices 400R, 400G, and 400B to form a color image. For example... Figure 1 As shown, the dichroic cross prism 500 is arranged such that the apexes of the four right-angled prisms overlap at the same central position when viewed from the side, forming an overall approximately cubic shape. In the dichroic cross prism 500, a dielectric multilayer film (not shown) is formed at the interface where the right-angled prisms are in contact with each other. This interface forms an approximately X-shape when viewed from the side.

[0037] The color image emitted from the cross-shaped dichroic prism 500 is magnified and projected by the projection optical system 600 to form an image on the SCR screen.

[0038] (Light source device)

[0039] Next, the structure of the light source device 100 of the projector 15 will be described.

[0040] Figure 2 This is a structural diagram of the light source device 100A according to the first embodiment. Figure 2 As shown, the light source device 100A includes light source units 111, 113, and 115, combining mirrors 122 and 124, and a mirror 131. In the following specification and figures, the direction parallel to the optical axis AX100 of the white light WL emitted from the light source device 100A is designated as the Z direction; the side relatively closer to the emission side of the light source device 100A in the Z direction is designated as the +Z side; and the side relatively opposite to the emission side in the Z direction is designated as the -Z side. Furthermore, a direction orthogonal to the Z direction is designated as the X direction; one side relatively opposite in the X direction is designated as the +X side, and the other side relatively opposite in the X direction is designated as the -X side. Additionally, a direction orthogonal to both the X and Z directions is designated as the Y direction; one side relatively opposite in the Y direction is designated as the +Y side, and the other side relatively opposite in the Y direction is designated as the -Y side.

[0041] The light source 111 is mounted on the optical axis AX100 and configured to be more efficient than the reference 111. Figure 1 The first lens array 70 is described on the -Z side. 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 with 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), which is formed to emit blue light LB1. The first light source 141 includes, for example, a light-emitting element (not shown) capable of emitting blue light LB1 and a substrate (not shown) supporting the light-emitting element. The peak wavelength of the blue light LB1 is, for example, included in the range of 440nm to 480nm, but is not limited to a specific value as long as it is a blue wavelength in the visible band. The size of the light-emitting area of ​​the blue light LB1 in the first light source 141 in the XY plane including the X and Y directions, that is, the beam diameter of the blue light LB1 immediately after being emitted from the first light source 141, is defined as S1.

[0042] The pickup optical system 142 is positioned on the optical axis AX100 at a position closer to the +Z side than the first light source 141. The pickup optical system 142 includes, 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 arranged sequentially from the -Z side to the +Z side with their respective axes aligned with the optical axis AX100, spaced apart from each other. The first lens 151 and the second lens 152 are, for example, convex lenses having a flat incident surface parallel to the XY plane and an exiting spherical surface that moves towards the +Z side from the outer periphery of the incident surface toward the axis. The third lens 153 is, for example, a convex lens having a flat incident surface parallel to the XY plane and an exiting aspherical surface that moves from the -Z side to the +Z side from the outer periphery of the incident surface toward the axis.

[0043] Furthermore, the number, arrangement, and shape of the lenses constituting the pickup optical system 142 are appropriately set considering the distance that the pickup optical system 142 can be set at in the Z direction, so as to capture as much blue light LB1 emitted from the light-emitting area of ​​the first light source 141 with a beam diameter S1 as possible, and to expand the blue light LB1 to the desired beam diameter at a position closer to the +Z side than the pickup optical system 142. The pickup optical system 142 magnifies the blue light LB1 incident from the first light source 141 to a size that is similar to the beam diameter incident on the reference. Figure 1 The white light WL of each of the image forming areas of the light modulation devices 400R, 400G, and 400B is required to have a beam diameter of approximately the same as that of blue light (first light) LB2, which is emitted along the Z direction toward the +Z side.

[0044] The light source unit 113 is positioned in the X direction at a position closer to the -X side than the optical path of the blue light LB2, overlaps with the optical path of the blue light LB2 in the Y direction, and is positioned in the Z direction at a position closer to the +Z side than the light source unit 111. 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.

[0045] Figure 3 This is a diagram showing the structure of the wavelength conversion unit 143 when viewed along the Y direction. (See diagram for example.) Figure 3As shown, the wavelength conversion unit 143 includes: a second light source 145 that emits blue light (second light) LB11 with a blue wavelength; and a wavelength conversion element 146 that converts the incident blue light containing the blue light LB11 into green light LG1. The second light source 145 is composed of a solid-state light source such as an LED that is formed to emit 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 and Z directions, and has a predetermined thickness along the X direction.

[0046] The light-emitting element 161 is directly stacked on the +X side of the substrate 160, on the surface 160a. The light-emitting element 161 has an emission surface 161e and an abutment surface 161b parallel to the YZ plane, and emits blue light LB11 from the emission surface 161e along the X direction toward the +X side. The peak wavelength of the blue light LB11 is, for example, the same as that of the blue light LB1, in the range of 440nm to 480nm, but it is not limited to a specific value as long as it can excite the wavelength conversion element 146 in a manner that allows the green light LG1 to be emitted from the wavelength conversion element 146.

[0047] The contact surface 161b of the light-emitting element 161 abuts against the plate surface 160a of the substrate 160. The size of the light-emitting area of ​​the blue light LB11 in the light-emitting element 161 in the YZ plane is smaller than the plate surfaces 160a and 160b of the substrate 160. Let S2 be the average size of the light-emitting element 161 of the second light source 145 in the YZ plane, that is, the beam diameter of the blue light LB11 just emitted from the second light source 145.

[0048] A wavelength conversion element 146 is stacked 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 each other on the YZ plane. Preferably, the first surface 146b of the wavelength conversion element 146 abuts against the emission surface 161e of the light-emitting element 161. As one example, when the region on the YZ plane that 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 is defined as Et, the wavelength conversion element 146 also extends to the region Et, and the end surface Eb of the wavelength conversion element 146 closest to the -X side can be bonded to the plate surface 160a of the substrate 160 by a photocurable resin or adhesive for sealing. As another example, a photocurable resin or any sealing material for sealing can also be disposed in the region Et. In any embodiment, there is no air layer between the first surface 146b of the wavelength conversion element 146 and the emission surface 161e of the light-emitting element 161, so they are in contact with each other.

[0049] Preferably, there is at least no air layer 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, or a layer that causes a loss of blue light LB11 emitted by the light-emitting element 161 due to a large difference in refractive index between the light-emitting element 161 and the wavelength conversion element 146.

[0050] Alternatively, a cover member (not shown), formed of, for example, optical glass in a plate shape, may be provided on the +X side of the emission surface 161e of the light-emitting element 161, in a state of 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, separated by the aforementioned cover member. The surface of the +X side of the aforementioned cover member abuts against the first surface 146b of the wavelength conversion element 146.

[0051] Blue light LB11 emitted from the light-emitting element 161 of the second light source 145 is incident on 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, a portion (at least a portion) of the blue light LB1 emitted from the first light source 141, namely blue light LB7, is incident on the wavelength conversion element 146 from the second surface 146a. The wavelength conversion element 146 uses the incident blue light LB7 and LB11 as excitation light to generate green light LG1 as fluorescence, thereby converting the blue light LB7 and LB11 into green light LG1. The green light LG1 has a green wavelength (second wavelength). The green wavelength is, for example, included in the range of 500 nm to 570 nm, but is not limited to a specific value as long as it is a green wavelength in the visible band.

[0052] The material of wavelength conversion element 146 is, for example, Lu3Al5O 12 Ce 3+ System phosphor, Y3O4:Eu 2+ System phosphor, (Ba,Sr)2SiO4:Eu 2+ Phosphor, Ba3Si6O 12 N2: Eu 2+ System phosphors and (Si,Al)6(O,N)8:Eu 2+ It can be any type of phosphor. However, the material of the wavelength conversion element 146 is not limited to any specific material, as long as it can convert the wavelengths of blue light LB7 and LB11 into green light LG1 with the desired green wavelength.

[0053] The wavelength conversion element 146 is the same size as the light-emitting element 161 of the second light source 145 in the YZ plane, but smaller than the substrate 160. Let S3 be the average size 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. The beam diameter S3 of the green light LG1 is preferably less than twice the beam diameter S1 of the blue light LB1, and more preferably equal to the beam diameter S1.

[0054] like Figure 2 As shown, the pickup optical system 144 is disposed in the X direction between the optical path of the blue light LB2 and the wavelength conversion element 146 of the light source unit 113, and is positioned closer to the +X side than the second light source 145 and the wavelength conversion element 146. The pickup optical system 144 includes, for example, a first lens 154, a second lens 155, and a third lens 156. The first lens 154, for example, has a flat surface on the incident side parallel to the YZ plane and a spherical surface on the emission side that moves towards the +X side from the outer periphery of the flat surface on the incident side toward the axis, and is constructed as a convex lens, similar to the first lens 151 of the pickup optical system 142. The second lens 155, for example, has a flat surface on the incident side parallel to the YZ plane and a spherical surface on the emission side that moves from the -X side toward the +X side from the outer periphery of the flat surface on the incident side toward the axis, and is constructed as a convex lens, similar to the second lens 152 of the pickup optical system 142. The third lens 156, for example, has a flat surface on the incident side parallel to the YZ plane and an aspherical surface on the emitting side that moves towards the +X side from the outer periphery of the flat surface on the incident side toward the axis, and is also composed of a convex lens, similar to the third lens 153 of the pickup optical system 142.

[0055] Furthermore, the number, arrangement, and shape of the lenses constituting the pickup optical system 144 are appropriately selected considering factors such as the distance that the pickup optical system 144 can be set in the X direction, so as to capture as much green light LG1 emitted from the wavelength conversion element 146 with a beam diameter S3 as possible, and to expand the green light LG1 to the desired beam diameter at a position closer to the +X side than the pickup optical system 144. The pickup optical system 144 magnifies the green light LG1 incident from the wavelength conversion element 146 into green light (third light) LG2 with a beam diameter approximately the same as the blue light LB2, and emits the green light LG2 towards the +X side along the X direction.

[0056] The light source unit 115 is disposed in the X direction on the -X side of the optical path of the blue light LB2 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 in the Z direction on the +Z side of the light source unit 113. 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 with a red wavelength. The third light source 147 includes, for example, a solid-state light source such as an LD or LED that is capable of emitting red light LR1. The third light source 147 includes, for example, a light-emitting element (not shown) capable of emitting red light LR1 and a substrate (not shown) supporting the light-emitting element. The peak wavelength of the red light LR1 is, for example, within the range of 600 nm to 800 nm, but is not limited to a specific value as long as it is a red wavelength within the visible band.

[0057] Let S5 be the average size of the emitting area of ​​the red light LR1 in the third light source 147 on the YZ plane, that is, the beam diameter of the red light LR1 immediately after being emitted from the third light source 147. Preferably, the beam diameter S5 of the red light LR1 is equal to the beam diameter S1 of the blue light LB1.

[0058] The pickup optical system 148 is disposed in the X direction between the optical path of the blue light LB2 and the light source 115, and is positioned on the +X side closer than the third light source 147. The pickup optical system 148 includes, for example, a first lens 157, a second lens 158, and a third lens 159. The first lens 157, for example, is a convex lens having a flat surface on the incident side and a spherical surface on the emission side, similar to the first lens 154 of the pickup optical system 144. The second lens 158, for example, is a convex lens having a flat surface on the incident side and a spherical surface on the emission side, similar to the second lens 155 of the pickup optical system 144. The third lens 159, for example, is a convex lens having a flat surface on the incident side and an aspherical surface on the emission side, similar to the third lens 156 of the pickup optical system 144.

[0059] Furthermore, the number, arrangement, and shape of the lenses constituting the pickup optical system 148 are appropriately selected considering factors such as the distance at which the pickup optical system 148 can be set in the X direction, so as to capture as much red light LR1 emitted from the third light source 147 with a beam diameter S5 as possible, and to expand the red light LR1 to the desired beam diameter at a position closer to the +X side than the pickup optical system 148. The pickup optical system 148 magnifies the red light LR1 incident from the third light source 147 into a red light LR2 with a beam diameter approximately the same as the blue light LB2, and emits the red light LR2 towards the +X side along the X direction.

[0060] A synthesizing mirror (optical component) 122 is disposed in the region where the optical paths of blue light LB2 emitted from the pickup optical system 142 of the light source unit 111 and green light LG2 emitted from the pickup optical system 144 of the light source unit 113 converge. The synthesizing mirror 122 is formed in the shape of a plate and has a first reflecting surface 171 and a second reflecting surface 172 on the side opposite to the first reflecting surface 171. The first reflecting surface 171 and the second reflecting surface 172 are arranged parallel to each other. The second reflecting surface 172 is located on the +Z side closer to 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 move from the end on the -X side to the +X side, forming an angle of approximately 45° with respect to the X direction and the Z direction respectively, and are arranged parallel with respect to the Y direction.

[0061] The first reflecting surface 171 reflects a portion of the blue light LB2 incident from the -Z side along the Z direction as blue light (first light) LB3 towards the +X side along the X direction. The first reflecting surface 171 allows at least a portion (another portion) of the remaining portion of the blue light LB2 incident as described above to pass through along the Z direction towards the +Z side. The blue light LB2 transmitted through the first reflecting surface 171 is refracted by the combining reflector 122 and emitted as blue light LB4 from the second reflecting surface 172 along the Z direction towards the +Z side. For example, when the amount of incident blue light LB2 is set to 100%, the amount of blue light LB3 emitted from the first reflecting surface 171 towards the +X side is appropriately adjusted within a range of approximately 20% to 50%.

[0062] The second reflecting surface 172 reflects the green light LG2 incident from the -X side along the X direction as green light LG3 towards the +Z side along the Z direction. For example, when the amount of incident green light LG2 is set to 100%, the amount of green light LG3 emitted from the second reflecting surface 172 is appropriately adjusted within the range of about 50% to 95%.

[0063] Blue light LB4 and green light LG3 emitted from the second reflecting surface 172 along the Z direction toward the +Z side are combined to generate cyan light (combined light) LC1. That is, the combining mirror 122 combines blue light (first light) LB4, which is part of blue light LB1 emitted from the first light source 141, and green light (third light) LG3, which is at least part of green light LG1 emitted from the wavelength conversion element 146, to emit cyan light LC1 along the Z direction toward the +Z side.

[0064] The composite mirror 122 includes, for example, a first mirror substrate (not shown), a first dielectric multilayer film forming a first reflective surface 171 (not shown), and a second dielectric multilayer film forming a second reflective surface 172 (not shown). The first mirror substrate is arranged at approximately 45° angles to both the X and Z directions, as described above, and is parallel to the Y direction. The first mirror substrate is formed of a material that allows at least blue light to pass through, such as optical glass that allows visible light to pass through. The first dielectric multilayer film is deposited on the surface of the first mirror substrate facing the light source portion 111 by a manufacturing method such as vapor deposition. The first dielectric multilayer film is designed considering the peak wavelength of blue light LB2, such that a portion of the incident blue light LB2 is reflected as blue light LB3, and at least a portion of the remaining portion is transmitted, as described above. The second dielectric multilayer film is deposited on the surface of the first mirror substrate facing the light source portion 113 by a manufacturing method such as vapor deposition. The second dielectric multilayer film is designed considering factors such as the peak wavelength of green light LG2, so that the incident green light LG2 is reflected as green light LG3 as described above, and green light and red light containing green light LG2 are also reflected, i.e., yellow light is reflected. Alternatively, the second dielectric multilayer film of the first embodiment can be configured to at least reflect the incident green light LG2 as green light LG3 and allow light with wavelengths of colors other than green to pass through; it can also be designed specifically for green light.

[0065] The synthesizing mirror 124 is disposed in the region where the optical path of the cyan light LC1 emitted from the synthesizing mirror 122 and the optical path of the red light LR2 emitted from the pickup optical system 148 of the light source unit 115 converge. The synthesizing mirror 124 is formed in the shape of a plate and has a third reflecting surface 173. The third reflecting surface 173 moves from the -Z side to the +Z side as it moves from the end on the -X side to the +X side, forming an angle of approximately 45° with respect to the X direction and the Z direction respectively, and is arranged parallel to the Y direction.

[0066] The third reflecting surface 173 reflects the red light LR2 incident from the -X side along the X direction as red light LR3 towards the +Z side along the Z direction. For example, when the amount of incident red light LR2 is set to 100%, the amount of red light LR3 emitted from the third reflecting surface 173 is appropriately adjusted within the range of about 50% to 95%.

[0067] Cyan light LC1 incident on the -Z side onto the combining mirror 124 passes through the combining mirror 124 and is emitted as cyan light LC2 along the Z direction toward the +Z side. Cyan light LC2 and red light LR3 emitted from the third reflecting surface 173 along the Z direction toward the +Z side are emitted from the third reflecting surface 173 and combined to generate white light (combined light) WL. That is, the combining mirror 124 combines blue light LB4, green light (third light) LG3, and red light LR3, which is at least a part of red light LR1 emitted from the third light source 147, to emit white light WL along the Z direction toward the +Z side.

[0068] The composite reflector 124, for example, has a second reflector substrate (not shown) and a third dielectric multilayer film (not shown) forming a third reflective surface 173. As described above, the second reflector substrate is arranged at approximately 45° angles with respect to the X and Z directions, respectively, and parallel to the Y direction. The second reflector substrate is formed of a material that allows at least blue and green light to pass through, such as optical glass that allows visible light to pass through, similar to the first reflector substrate. The third dielectric multilayer film is stacked on the surface of the second reflector substrate facing the light source portion 115. The third dielectric multilayer film is designed with consideration of the peak wavelength of red light LR2, etc., so that the incident red light LR2 is reflected as red light LR3 as described above, and light with wavelengths of colors other than red is transmitted.

[0069] A reflector 131 is positioned on the optical path of the blue light LB3 reflected by the first reflecting surface 171 of the synthesizing reflector 122. In the X direction, it is positioned closer to the +X side of the synthesizing reflector 122, and in the Y and Z directions, it is positioned in the regions overlapping with the synthesizing reflector 122. The reflector 131 is formed in a plate shape and has a fourth reflecting surface 174. The fourth reflecting surface 174 is arranged parallel to the YZ plane.

[0070] The fourth reflecting surface 174 reflects blue light LB3 incident from the -X side along the X direction as blue light (first light) LB5 towards the -X side along the X direction. The reflectivity of the blue light in the fourth reflecting surface 174 is preferably, for example, 80% or more, and can be adjusted appropriately. Furthermore, the structure of the reflector 131 is not particularly limited as long as it has the fourth reflecting surface 174 and can reflect blue light LB3 as described above. For example, a total internal reflection mirror for blue light or a total internal reflection mirror for visible light can be used for the reflector 131.

[0071] In the light source device 100A equipped with the aforementioned structural elements, at least a portion of the blue light LB2 emitted from the light source unit 111 is split into blue light LB3 and blue light LB4 by the combining mirror 122. The blue light LB5 reflected by the mirror 131 passes through the combining mirror 122 and is emitted as blue light LB6 along the X direction toward the -X side from the second reflecting surface 172. The blue light LB6 passes through the pickup optical system 144 and is emitted as blue light LB7, which converges and enters from the +X side relative to the wavelength conversion element 146 of the light source unit 113. The beam diameter of the blue light LB7 on the second surface 146a of the wavelength conversion element 146 is smaller than that of the blue light LB6 due to the pickup optical system 144.

[0072] like Figure 3 As shown, in the light source section 113, blue light LB11 emitted from the second light source 145 illuminates the first surface 146b from the -X side and is incident on the wavelength conversion element 146. Furthermore, blue light LB7, which converges from the pickup optical system 144 along the X direction towards the -X side, illuminates the second surface 146a from the +X side and is incident on the wavelength conversion element 146. That is, blue light LB7 is the excitation light from the first light source 141 that reaches the second surface 146a via the path of the synthesizing mirror 122. Blue light LB11 is the original excitation light from the second light source 145, which together with the wavelength conversion element 146 constitutes the wavelength conversion section 143. The wavelength conversion element 146 is excited by the blue light LB11 and blue light LB7 incident from both the first surface 146b and the second surface 146a in the X direction.

[0073] like Figure 2 As shown, blue light LB4, which passes through the combining mirror 122, and green light LG2, emitted from the wavelength conversion element 146 of the light source 113 towards the +X side, are combined by the combining mirror 122. Cyan light LC1 is emitted towards the combining mirror 124 on the +Z side. Cyan light LC1 incident on the combining mirror 124 and red light LR2 emitted from the light source 115 are combined by the combining mirror 124. White light WL is emitted from the combining mirror 124 along the Z direction towards the +Z side. In the light source device 100A, the optical path of white light WL can also be as shown... Figure 2 The optical element 140 is configured as shown by the dashed line. The optical element 140 is used to adjust the beam shape and intensity distribution of the white light WL emitted from the synthetic reflector 122 to a desired shape and distribution, directed towards... Figure 1 The element emitted from the first lens array 70 of the illumination device 20 shown can 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 the desired shape and distribution as described above, and can be, for example, a diffuser plate, a microlens array, etc.

[0074] Furthermore, the amounts of red light LR3, green light LG3, and blue light LB4 constituting the white light WL are appropriately set considering the color balance required for the white light WL emitted from the light source device 100A. Additionally, considering the optimal light quantity ratio of red light LR3, green light LG3, and blue light LB4, the reflectivity and transmittance of the first reflecting surface 171 to blue light LB2, the reflectivity of the second reflecting surface 172 to green light LG2, the reflectivity of the third reflecting surface 173 to red light LR2, and the reflectivity of the fourth reflecting surface 174 to blue light LB3 are appropriately set.

[0075] The light source device 100A of the first embodiment described above includes at least a first light source 141, a second light source 145, a wavelength conversion element 146, a combining mirror 122, and a 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, which receives the blue light LB11 emitted from the second light source 145; and a second surface 146a, which is located on the opposite side of the first surface 146b in the X direction and is opposite to the first surface 146b. The wavelength conversion element 146 converts the blue light LB11 into green light LG1 having a green wavelength different from that of blue. The combining mirror 122 combines the blue light LB4 and the green light LG3 and emits cyan light LC1. The reflector 131 reflects the blue light LB3 emitted from the synthesizing reflector 122 along the X direction toward the +X side toward the -X side. The blue light LB5 reflected by the reflector 131 is incident on the second surface 146a of the wavelength conversion element 146 via the synthesizing reflector 122 and is converted into green light LG1.

[0076] In the light source device 100A of the first embodiment, blue light LB7, which is part of blue light LB1 emitted from the first light source 141, is used to excite the wavelength conversion element 146 to generate green light LG1. According to the light source device 100A of the first embodiment, by using a portion of the light-abundant blue light to excite the wavelength conversion element 146 that generates green light G, the green light G, which is easily insufficient in light quantity when emitted from a phosphor compared to the blue light and red light emitted directly from a solid light source such as an LD or LED, can be supplemented by using a portion of the light-abundant blue light to excite the wavelength conversion element 146 that generates green light G. Specifically, without making the size of the wavelength conversion element 146 in the YZ plane excessively large compared to the size of the light-emitting area of ​​the first light source 141, the remaining blue light LB7 of the blue light LB1 directly emitted from the first light source 141 can be incident on the second surface 146a of the wavelength conversion element 146, opposite to the first surface 146b where the original excitation light, i.e., the blue light LB11, is incident. This excites the wavelength conversion element 146 from both surfaces in the X direction. As a result, the light output and efficiency of the light source device 100A can be improved without significantly altering the RGB balance in the white light WL.

[0077] In the light source device 100A of the first embodiment, the optical system for combining blue light and green light to form cyan light is constructed by adding a reflector 131 to an optical system consisting of a light source 111 that emits blue light LB2, a light source 113 that emits green light LG2, and a combining reflector 122. Therefore, the impact on the cost and overall size of the light source device 100A can be minimized.

[0078] Furthermore, in the light source device 100A of the first embodiment, as described above, blue light LB11 and blue light LB7 are irradiated onto the wavelength conversion element 146 from both the first surface 146b and the second surface 146a. Therefore, the beam diameter S3 of the second surface 146a of the wavelength conversion element 146 and the green light LG1 is not excessively larger than the light-emitting area of ​​the first light source 141 and the beam diameter S1 of the blue light LB1, thus improving the efficiency of the wavelength conversion element 146. The smaller the beam diameter S3 of the green light LG1, the more light LG1 is captured by the pickup optical system 144, and the larger the size of the pickup optical system 144 can be suppressed. That is, the conversion efficiency in the wavelength conversion element 146 can be improved, the amount of green light LG2 can be increased, and the size of the light source section 113 can be suppressed to the same extent as the light source section 111. According to the light source device 100A of the first embodiment, a good balance of blue light, green light, and red light as in conventional light source devices can be achieved, and the overall miniaturization of the device can be realized.

[0079] Furthermore, in the light source device 100A of the first embodiment, the combining mirror 122 transmits at least a portion of the incident blue light LB2 as blue light LB4 and reflects at least a portion of the incident green light LG2 as green light LG3, generating cyan light LC1 as a composite light of blue light LB4 and green light LG3. The combining mirror 122 reflects another portion of the incident blue light LB2 as blue light LB3 to the mirror 131.

[0080] In the light source device 100A of the first embodiment, a portion of the blue light LB2 emitted by the first light source 141 is reflected as blue light LB3 on the first reflecting surface 171 of the synthesizing mirror 122. The picking-up optical system 144 is used to converge the blue light LB5 reflected by the mirror 131 that has passed through the synthesizing mirror 122 to the blue light LB6.

[0081] Blue light LB7 is irradiated onto the second surface 146a of the wavelength conversion element 146. According to the light source 5 apparatus 100A of the first embodiment, a single synthesizing mirror 122 can be used to branch the blue light LB2 into blue light LB3, which irradiates the wavelength conversion element 146 to excite the wavelength conversion element 146, and blue light LB4, which is used to synthesize cyan light LC1. Furthermore, a single synthesizing mirror 122 can be used to allow blue light LB3 to pass through the wavelength conversion element 146 as blue light LB6 and LB7, so that the light from the wavelength conversion element 146 is parallel to the optical path of blue light LB6 and LB7.

[0082] The green light LG2 emitted in the X direction merges with the blue light LB4 to generate cyan light LC1. Therefore, it is possible to suppress the enlargement of the light source device 100A in the first embodiment.

[0083] In the light source device 100A of the first embodiment, a combining mirror 122 is disposed between the wavelength conversion element 146 of the wavelength conversion section 143 and the reflector 131 in the X direction (first direction). In the X direction, the wavelength conversion element 146 is disposed at a position closer to the -X side than the combining mirror 122, and the reflector 131 is disposed at a position closer to the -X side than the combining mirror 122.

[0084] The reflector 122 is positioned near the +X side. The first light source 141 is arranged at a distance from the combining reflector 122 in the Z direction (second direction), which is orthogonal to the X direction, and is positioned near the -Z side of the combining reflector 122. The second surface 146a of the wavelength conversion element 146 is arranged in the X direction on the side of the wavelength conversion element 146 facing the reflector 131, that is, the +X side of the wavelength conversion element 146. The second light source 145 of the wavelength conversion section 143 is arranged in the X direction on the side opposite to the side of the wavelength conversion element 146 facing the reflector 131, that is, the -X side of the wavelength conversion element 146. The second light source 145 overlaps with the wavelength conversion element 146, the reflector 131, and the combining reflector 122 in the Z direction.

[0085] In the light source device 100A of the first embodiment, in the arrangement of the above-described structural elements, the second surface 146a of the wavelength conversion element 146 and the fourth reflective surface 174 of the reflector 131 are arranged parallel to the YZ plane. The first reflective surface 171 of the synthesizing reflector 122 is arranged facing the first light source 141 and the reflector 131. The second reflective surface 172 of the synthesizing reflector 122 is arranged facing the wavelength conversion element 146 and the emission portion of the white light WL. The first reflective surface 171 and the second reflective surface 172 move from the -X side to the +X side as they move from the -Z side to the +Z side. With the above-described configuration, the optical paths of a portion of the blue light LB1 emitted from the first light source 141, namely the blue lights LB5 to LB7, the optical paths of the blue lights LB11 and LB7 used to excite the wavelength conversion element 146, and the optical paths of the wavelength-converted green lights LG1 and LG2 can overlap each other along the X direction. Therefore, it is possible to suppress the large size of the light source device 100A in the first embodiment and the total number of optical elements and optical components, and to achieve high efficiency in wavelength conversion by using the remaining portion of the blue light LB1 used to synthesize white light WL, namely blue light LB7, to excite the wavelength conversion element 146.

[0086] In the light source device 100A of the first embodiment, the first surface 146b of the wavelength conversion element 146 abuts against the emission surface (emission surface from which the second light is emitted) 161e of the light-emitting element 161 of the second light source 145. According to the light source device 100A of the first embodiment, blue light LB11 emitted from the emission surface 161e of the light-emitting element 161 of the second light source 145 can be efficiently incident from the first surface 146b onto the wavelength conversion element 146. Therefore, it is not necessary to apply excessive load to the blue light LB7 allocated to ensure the wavelength conversion efficiency of the wavelength conversion element 146, and the degree of freedom in setting the reflectivity of the first reflecting surface 171 and the second reflecting surface 172 of the composite mirror 122 is expanded.

[0087] The projector 15 of the first embodiment includes: the light source device 100A described above; light modulation devices 400R, 400G, and 400B, which modulate the light from the light source device 100A according to image information, thereby forming image light; and a projection optical system 600, which projects the image light. According to the projector 15 of the first embodiment, since it includes the light source device 100A, it is possible to obtain good color balance of white light WL, improve the brightness and chromaticity of the image projected onto the screen SCR, and achieve miniaturization.

[0088] [Second Implementation]

[0089] Next, use Figure 4 The second embodiment of the present invention will be described.

[0090] Furthermore, in subsequent embodiments, structures identical to those in the above-described embodiments are labeled with the same reference numerals, and their descriptions are omitted. In subsequent embodiments, structures and contents that differ from those in the above-described embodiments are primarily described.

[0091] Furthermore, unless otherwise specified, the structure of the projector other than the light source device in each of the embodiments after the second embodiment is the same as the structure of the projector 15 in the first embodiment.

[0092] Figure 4 This is a structural diagram of the light source device 100B according to the second embodiment. Figure 4 As shown, the light source device 100B, like the light source device 100A described in the first embodiment, includes light source units 111, 113, 115, composite reflectors 122, 124, and reflector 131. However, in the light source device 100B, the arrangement of the light source units 111 and 113 is reversed compared to that of the light source device 100A.

[0093] That is, the light source unit 111 is disposed in the Z direction at least more than the reference. Figure 1 The first lens array 70, positioned on the -Z side, is located closer to the -Z side than the light source unit 115, overlapping with the synthesizing mirror 122 and the mirror 131. The first light source 141 of the light source unit 111 emits blue light LB1 along the X direction toward the +X side. The pickup optical system 142 emits blue light LB2 along the X direction toward the +X side.

[0094] Light source 113 is disposed on optical axis AX100, and is positioned in the Z direction closer to the -Z side than light source 111, combining mirror 122, and mirror 131. Light source 113 overlaps with combining mirrors 122 and 124 in the X direction. The second light source 145 of wavelength conversion unit 143 emits blue light LB11 towards the +Z side relative to the Z direction. Wavelength conversion element 146 of wavelength conversion unit 143 is disposed in a position closer to the +Z side than the second light source 145. The first surface 146b and the second surface 146a of wavelength conversion element 146 are disposed parallel to the XY plane including the X and Y directions. The second surface 146a of wavelength conversion element 146 is disposed in a position closer to the +Z side than the first surface 146b.

[0095] As described below, a portion (at least a portion) of the blue light LB1 emitted from the first light source 141, namely the blue light LB7, is incident on the second surface 146a along the Z direction from the +Z side, and then incident on the wavelength conversion element 146 from the second surface 146a. The wavelength conversion element 146 uses the incident blue light LB7 and LB11 as excitation light to generate green light LG1, thereby converting the wavelengths of the blue light LB7 and LB11 into green light LG1.

[0096] The composite mirror (optical component) 122 has a fifth reflecting surface 175 and a sixth reflecting surface 176 replacing 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 advance from the end on the -X side towards the +X side, forming approximately 45° angles with respect to the X direction and the Z direction respectively, and are arranged parallel to the Y direction. As described later, the fifth reflecting surface 175 allows at least a portion of the blue light LB2 incident from the -X side along the X direction via the sixth reflecting surface 176 to be transmitted as blue light LB3, and reflects at least a portion of the blue light LB5 incident from the +X side as blue light LB6 along the Z direction towards the -Z side. The fifth reflecting surface 175 allows green light LG2 incident from the -Z side along the Z direction to be transmitted. The sixth reflecting surface 176 allows at least a portion of the blue light LB2 incident from the -X side along the X direction to pass through, and reflects at least a portion (another portion) of the remaining portion of the blue light LB2 as blue light LB4 towards the +Z side along the Z direction.

[0097] The composite mirror 122, for example, includes a first mirror substrate (not shown), a fifth dielectric multilayer film forming a fifth reflective surface 175 (not shown), and a sixth dielectric multilayer film forming a sixth reflective surface 176. The fifth dielectric multilayer film is deposited on the surface of the first mirror substrate facing the light source portion 113 by a manufacturing method such as vapor deposition. The fifth dielectric multilayer film is designed considering the peak wavelength of blue light LB2, etc., such that at least a portion of the incident blue light LB2 is transmitted as blue light LB3, and at least a portion of the incident blue light LB5 is reflected along the Z direction towards the -Z side, as described above. The sixth dielectric multilayer film is deposited on the surface of the first mirror substrate facing the light source portion 111 by a manufacturing method such as vapor deposition. The sixth dielectric multilayer film is designed considering the peak wavelength of blue light LB2, etc., such that at least a portion of the incident blue light LB2 is transmitted, and at least a portion of the remaining portion of the blue light LB2 is reflected along the Z direction towards the +Z side, as described above. The fifth and sixth dielectric multilayer films were designed with consideration of the peak wavelength of green light LG2, allowing light with wavelengths other than blue to pass through.

[0098] In the light source device 100B equipped with the aforementioned structural elements, at least a portion of the blue light LB2 emitted from the light source unit 111 is split into blue light LB3 and blue light LB4 by the synthesizing mirror 122. The blue light LB5 emitted from the mirror 131 is reflected by the synthesizing mirror 122 and emitted as blue light LB6 along the Z direction toward the -Z side from the fifth reflecting surface 175. The blue light LB6 passes through the pickup optical system 144 and is emitted as blue light LB7, which 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 green light LG1 from the second surface 146a along the Z direction toward the +Z side.

[0099] Blue light LB4 reflected by the synthesizing mirror 122 and green light LG3 emitted from the wavelength conversion element 146 of the light source 113 towards the +Z side and passing through the fifth reflecting surface 175 of the synthesizing mirror 122 are synthesized at the sixth reflecting surface 176 of the synthesizing mirror 122. Cyan light LC1 is emitted from the sixth reflecting surface 176 of the synthesizing mirror 122 towards the synthesizing mirror 124 on the +Z side. Similar to the first embodiment, the synthesizing mirror 124 synthesizes the incident cyan light LC1 and the red light LR2 emitted from the light source 115, and emits the generated white light WL along the Z direction towards the +Z side.

[0100] In addition, considering the optimal light intensity ratio of red light LR3, green light LG3 and blue light LB4, the reflectivity of the 5th reflective surface 175 to blue light LB5 and the transmittance to blue light LB2, the reflectivity of the 6th reflective surface 176 to blue light LB2, the reflectivity of the 3rd reflective surface 173 to red light LR2, and the reflectivity of the 4th reflective surface 174 to blue light LB3 are appropriately set.

[0101] In the light source device 100B of the second embodiment described above, similarly to the light source device 100A of the first embodiment, blue light LB7, which is part of 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, green, and red light constituting white light WL, a portion of the blue light with abundant light quantity can be used to supplement the green light, which is prone to being insufficient in light quantity compared to the blue and red light. As a result, the light output from the light source device 100B can be increased without significantly altering the RGB balance in the white light WL.

[0102] Furthermore, in the light source device 100B of the second embodiment, the combining mirror 122 reflects at least a portion of the incident blue light LB2 as blue light LB4, and allows at least a portion of the incident green light LG2 to pass through as green light LG3, generating a composite light of blue light LB4 and green light LG3, namely cyan light LC1. The combining mirror 122 allows another portion of the incident blue light LB2 to pass through towards the mirror 131.

[0103] In the light source device 100B of the second embodiment, a portion of the blue light LB2 of the first light source 141 is transmitted as blue light LB3 through the sixth reflecting surface 176 and the fifth reflecting surface 175 of the synthesizing mirror 122. The picking-up optical system 144 converges the blue light LB5 reflected by the fifth reflecting surface 175 of the synthesizing mirror 122 into blue light LB5 reflected by the mirror 131, and illuminates the second surface 146a of the wavelength conversion element 146 as blue light LB7.

[0104] According to the light source device 100B of the second embodiment, a single synthesizing mirror 122 is used to branch blue light LB2 into blue light LB3, which illuminates the wavelength conversion element 146 to excite the wavelength conversion element 146, and blue light LB4, which is used to synthesize cyan light LC1. Furthermore, the single synthesizing mirror 122 can be used to reflect blue light LB3 toward the wavelength conversion element 146 as blue light LB6 and LB7, and the green light LG2 emitted from the wavelength conversion element 146 along the Z direction parallel to the optical paths of blue light LB6 and LB7 can be combined with the optical path of blue light LB4 to generate cyan light LC1. As a result, the large size of the light source device 100B of the second embodiment can be suppressed.

[0105] Furthermore, according to the second embodiment of the light source device 100B, similarly to the first embodiment, a lens is not used, but a composite mirror 122 and a mirror 131 are used. Blue light LB6 is branched off from the blue light LB2 emitted from the light source 111 and incident on the second surface 146a of the wavelength conversion element 146, and irradiates towards the light source 113. Therefore, the generation of spherical aberration in the blue light LB6 can be suppressed.

[0106] Although not shown, the projector of the second embodiment has a light source device 100B, which is the light source device 100 of the projector 15 of the first embodiment, instead of the light source device 100A. According to the projector of the second embodiment, the brightness and color of the image projected onto the SCR screen can be improved, and miniaturization can be achieved.

[0107] [Third Implementation]

[0108] Next, use Figure 5 The third embodiment of the present invention will be described.

[0109] Figure 5 This is a structural diagram of the light source device 100G according to the third embodiment. Figure 5 As shown, the light source device 100G of the third embodiment has the same light source units 111 and 117, composite reflector 122 and reflector 131 as the light source device 100A of the first embodiment.

[0110] 100G replacement of light source device Figure 2 The light source device 100A shown has a light source section 113 with a light source section 117, but it may also omit the light source section 115 and the synthesizing mirror 124. The light source section 117 has a wavelength conversion section 181 and a pickup optical system 191. The wavelength conversion section 181 emits yellow light (third light) LY1.

[0111] Figure 6 This is a diagram showing the structure of the wavelength conversion unit 181 when viewed along the Y direction. (See diagram for example.) Figure 6 As shown, 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 containing 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, the same as that of the blue light LB1, for example, in the range of 440nm to 480nm, but it is not limited to a specific value as long as it can excite the wavelength conversion element 182 in a way that allows the yellow light LY1 to be emitted from the wavelength conversion element 182.

[0112] A wavelength conversion element 182 is stacked 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 each other on the YZ plane. Preferably, the first surface 182b of the wavelength conversion element 182 abuts against the emission surface 161e of the light-emitting element 161. Regarding the arrangement between the light-emitting element 161 and the wavelength conversion element 182, consider the arrangement or variation of the arrangement between the light-emitting element 161 and the wavelength conversion element 146 described in the first embodiment, in which the wavelength conversion element 146 is replaced by the wavelength conversion element 182. Preferably, there is no air layer or layer that causes loss of blue light LB11 between the first surface 182b of the wavelength conversion element 182 and the emission surface 161e of the light-emitting element 161.

[0113] Blue light LB7, as a portion (at least a part) of blue light LB1 emitted from the first light source 141, is incident on the second surface 182a onto the wavelength conversion element 182. The wavelength conversion element 182 uses the incident blue light LB7 and LB11 as excitation light to generate yellow light LY1 as fluorescence, thereby converting the wavelengths of the blue light LB7 and LB11 into yellow light LY1. Yellow light LY1 has a yellow wavelength (second wavelength) that includes both green and red wavelengths. The yellow wavelength is, for example, contained in the range of 570 nm to 630 nm, but is not limited to a specific value as long as it is a yellow wavelength within the visible band.

[0114] The material of wavelength conversion element 182 may include, for example, yttrium aluminum garnet (YAG) phosphors. As an activator, YAG:Ce containing cerium (Ce) is used as an example. Other materials that can be used as wavelength conversion element 182 include materials obtained by mixing raw material powders containing constituent elements such as Y₂O₃, Al₂O₃, and CeO₃ and subjecting them to a solid-phase reaction; Y-Al-O amorphous particles obtained by wet methods such as co-precipitation or sol-gel methods; and YAG ions obtained by gas-phase methods such as spray drying, flame thermal decomposition, or thermal plasma methods. However, the material of wavelength conversion element 182 is not limited to any specific material, as long as it can convert the blue light wavelengths LB7 and LB11 into yellow light LY1 with the desired yellow wavelength.

[0115] When the average size of the emitting region of the yellow light LY1 in the wavelength conversion element 182 on the YZ plane, that is, the beam diameter of the yellow light LY1 just after being emitted from the wavelength conversion element 182, is set to S3, the beam diameter S3 of the yellow light LY1 is preferably less than twice the beam diameter S1 of the blue light LB1, and more preferably equal to the beam diameter S1.

[0116] like Figure 5 As shown, the pickup optical system 191 is disposed in the X direction between the optical path of the blue light LB2 and the wavelength conversion element 182 of the light source unit 117, and is positioned on the +X side relative to the second light source 145 and the wavelength conversion element 182. The pickup optical system 191 includes, for example, a first lens 194, a second lens 195, and a third lens 196. The first lens 194, the second lens 195, and the third lens 196 are all convex lenses, similar to the first lens 154, the second lens 155, and the third lens 156 of the pickup optical system 142.

[0117] Furthermore, similar to the embodiment described above, the number, arrangement, and shape of the lenses constituting the pickup optical system 191 are appropriately selected considering factors such as the distance that the pickup optical system 191 can be set at in the X direction, so as to capture as much yellow light LY1 emitted from the wavelength conversion element 182 with a beam diameter S3 as possible, and to expand the yellow light LY1 to a desired beam diameter at a position closer to the +X side than the pickup optical system 191. The pickup optical system 191 magnifies the yellow light LY1 incident from the wavelength conversion element 182 into yellow light (third light) LY2 with a beam diameter approximately the same as that of the blue light LB2, and emits the yellow light LY2 towards the +X side along the X direction.

[0118] The synthesizing mirror (optical component) 122 is disposed in the region where the optical path of blue light LB2 and the optical path of yellow light LY2 emitted from the pickup optical system 191 of the light source unit 113 converge. The synthesizing mirror 122 is formed in the shape of a plate and has a first reflecting surface 171 and a seventh reflecting surface 177 on the side opposite to the first reflecting surface 171. The seventh reflecting surface 177 is located on the +Z side closer than the first reflecting surface 171. The seventh reflecting surface 177 moves from the -Z side to the +Z side as it moves from the end on the -X side to the +X side, forming an angle of approximately 45° with respect to the X direction and the Z direction respectively, and is arranged parallel to the Y direction.

[0119] The 7th reflecting surface 177 reflects the yellow light LY2 incident from the -X side along the X direction as yellow light LY3 towards the +Z side along the Z direction. For example, when the amount of incident yellow light LY2 is set to 100%, the amount of yellow light LY3 emitted from the 7th reflecting surface 177 is appropriately adjusted within the range of about 50% to 95%.

[0120] Blue light LB4 and yellow light LY3 emitted from the 7th reflecting surface 177 along the Z direction toward the +Z side are combined to generate white light (composite light) WL. That is, the combining mirror 122 combines blue light (first light) LB4, which is part of blue light LB1, and yellow light (third light) LY3, which is at least part of yellow light LY1 emitted from the wavelength conversion element 182, to emit white light WL along the Z direction toward the +Z side.

[0121] The composite mirror 122 is constructed in the same manner as the structural elements described in the first embodiment. However, instead of the second dielectric multilayer film (not shown) forming the second reflective surface 172, the composite mirror 122 has a seventh dielectric multilayer film forming the seventh reflective surface 177. The seventh dielectric multilayer film is deposited on the surface of the first mirror substrate facing the light source section 117 by a manufacturing method such as vapor deposition, and reflects the incident yellow light LY2 as yellow light LY3 as described above. However, if the second dielectric multilayer film of the composite mirror 122 described in the first embodiment is not specifically designed for green light but is designed to reflect yellow light containing green light LG2 as described above, the composite mirror 122 of the light source device 100G can also be constructed in the same manner as the composite mirror 122 of the light source device 100A.

[0122] The operation 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 7th reflecting surface 177 of the combining mirror 122 and is reflected by the 7th reflecting surface 177 along the Z direction toward the +Z side. The blue light LB4 that has passed through the combining mirror 122 and the yellow light LY3 reflected by the 7th reflecting surface 177 of the combining mirror 122 are combined when emitted from the 7th reflecting surface 177 toward the +Z side. That is, white light WL is emitted from the 7th reflecting surface 177 of the combining mirror 122 toward the +Z side. Figure 1 The first lens array 70 of the illumination device 20 shown emits light. The synthesizing mirror 122 combines a portion of the incident blue light LB2, namely blue light LB4, with the yellow light LY2 emitted from the light source 117, and emits the generated white light WL along the Z direction toward the +Z side.

[0123] The light source device 100G of the third embodiment described above has the same structure as the light source device 100A of the first embodiment, and therefore performs the same function as the light source device 100A.

[0124] In the light source device 100G of the third embodiment, there is a light source unit 117 that emits yellow light LY1 and LY2. In the light source device 100A of the first embodiment, the functions of the light source unit 115 and the synthesizing mirror 124 are concentrated in the light source unit 113 and the synthesizing mirror 122. Therefore, compared with the light source device 100A of the first embodiment, further miniaturization can be achieved.

[0125] Although not shown, the projector of the third embodiment has a light source device 100G, which is the light source device 100 of the projector 15 of the first embodiment, instead of the light source device 100A. According to the projector of the third embodiment, the brightness and color of the image projected onto the SCR screen can be improved, and it can be miniaturized compared to the projector of the first embodiment.

[0126] [Fourth Implementation]

[0127] Next, use Figure 7 The fourth embodiment of the present invention will be described.

[0128] Figure 7 This is a structural diagram of the light source device 100C according to the fourth embodiment. Figure 7 As shown, the light source device 100C of the fourth embodiment has the same light source units 111, 113, 115, composite mirrors 122, 124 and mirror 131 as the light source device 100A of the first embodiment.

[0129] In the light source device 100C, the fourth reflecting surface (reflecting surface) 174 of the reflector 131 is not parallel to the YZ plane, but is arranged at an angle θt relative to the YZ plane. When viewed along the Y direction, the fourth reflecting surface 174 has a planar shape and moves by a fixed amount from the -Z side to the +Z side and from the +X side to the -X side as it moves forward from the -Z side to the +Z side.

[0130] The movement and travel paths of the blue, green, and red light in the light source device 100C are the same as those in the light source device 100A. However, in the light source device 100C, the fourth reflecting surface 174 of the reflector 131 is tilted at an angle θt relative to the YZ plane. Therefore, the area where the blue light LB5, reflected by the reflector 131 and emitted from the fourth reflecting surface 174, incident on the first reflecting surface 171 is shifted towards the -Z side compared to the area where the blue light LB5 incident on the first reflecting surface 171 in the light source device 100A. The amount of shift of the area where the blue light LB5 incident on the first reflecting surface 171 towards the -Z side varies depending on the angle θt and the separation distance between the fourth reflecting surface 174 and the first reflecting surface 171 in the Z direction.

[0131] The light source device 100C and projector of the fourth embodiment described above have the same structure as the light source device 100A and projector of the first embodiment, and therefore have the same function as the light source device 100A and projector.

[0132] Furthermore, in the light source device 100C of the fourth embodiment, the reflector 131 has a fourth reflecting surface 174 that reflects the blue light (first light) LB3 emitted from the first reflecting surface 171 along the X direction toward the +X side, which is reflected by the synthesizing reflector 122. The fourth reflecting surface 174 is inclined relative to the YZ plane (the plane orthogonal to the optical axis of the first light) which is orthogonal to the optical axis of the incident blue light LB3.

[0133] In the light source devices 100A and 100C, the blue light LB5, reflected by the reflector 131 and emitted towards the -X side, is refracted at the first reflecting surface 171 of the combining reflector 122, traveling towards the -X side while moving towards the +Z side. The amount of movement of the blue light LB5 in the Z direction is determined by the refraction angle on the first reflecting surface 171, and varies according to the difference in refractive index between air and the first reflecting substrate of the combining reflector 122. The blue light LB5 is refracted again at the second reflecting surface 172 and emitted towards the -X side. Thus, through the refraction of the blue light LB5 by the combining reflector 122, the centroid of the converged spot of the blue light LB7 on the second surface 146a of the wavelength conversion element 146 is slightly offset towards the -Z side from the intersection of the optical axis of the blue light LB5 and the first reflecting surface 171.

[0134] In the light source device 100C of the fourth embodiment, as described above, the fourth reflecting surface 174 is tilted at an angle θt relative to the YZ plane. Therefore, compared with the light source device 100A of the first embodiment, where the fourth reflecting surface is parallel to the YZ plane, the centroid of the converging spot of the blue light LB7 deviates in the Z direction, and the illuminance deviation of the converging spot of the blue light LB7 changes. According to the light source device 100C of the fourth embodiment, by adjusting the degree of tilt of the fourth reflecting surface 174 relative to the YZ plane, i.e., the angle θt, the position of the centroid of the converging spot of the blue light LB7 on the second surface 146a of the wavelength conversion element 146 in the Z direction can be adjusted, thereby adjusting the illuminance deviation of the blue light LB7 incident on the wavelength conversion element 146. Furthermore, in the light source device 100C of the fourth embodiment, by tilting the fourth reflecting surface 174 of the reflector 131 as described above, the deviation of the optical path and optical axis of the blue light LB6 from the optical path and optical axis of the green light LG2 in the thickness direction of the first reflector substrate and dielectric multilayer film of the composite reflector 122, as well as spherical aberration, can be reduced.

[0135] 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 converging spot of the blue light LB7 is adjusted or moved on the second surface 146a, the adjustment amount of the illuminance deviation of the converging spot of the blue light LB7, and the separation distance between the fourth reflecting surface 174 in the X direction and the second surface 146a of the wavelength conversion element 146.

[0136] Furthermore, considering the shape of the wavelength conversion element 146 in the YZ plane, the fourth reflecting surface 174 can also be tilted at an angle θt relative to the YZ plane, and move from the +X or -X side to the -X or +X side when moving along the Y direction. In this case, by adjusting the angle θt, the position of the centroid of the converging spot of the blue light LB7 on the second surface 146a of the wavelength conversion element 146 in the Y direction and the illuminance deviation can be adjusted, thereby optimizing the illuminance distribution of the blue light LB7 on the second surface 146a.

[0137] Furthermore, in the light source device 100B of the second embodiment and the light source device 100G of the third embodiment, the structure of the light source device 100C of the fourth embodiment can also be applied, such that the fourth reflecting surface 174 of the reflector 131 is arranged obliquely relative to the YZ plane. In such a structure, the same effect as that of the light source device 100C of the fourth embodiment can also be obtained.

[0138] [Fifth Implementation]

[0139] Next, use Figure 8 The fifth embodiment of the present invention will be described.

[0140] Figure 8 This is a structural diagram of the light source device 100D according to the fifth embodiment. (As shown...) Figure 8 As shown, the light source device 100D of the fifth embodiment has the same light source units 111, 113, 115, composite mirrors 122, 124 and mirror 131 as the light source device 100A of the first embodiment.

[0141] In the light source device 100D, the fourth reflecting surface (reflecting surface) 174 of the reflector 131 is not parallel to the YZ plane, but is curved with a predetermined radius of curvature relative to the YZ plane. When viewed along the Y direction, the fourth reflecting surface 174 moves from the -Z side to the +Z side, then moves in a manner that traces a curve from the -X side to the +X side, and finally moves in a manner that traces a curve from the +X side to the -X side. The vertex of the +X side of the fourth reflecting surface 174 approximately overlaps with the optical axis of the incident blue light LB3.

[0142] The movement and travel paths of the blue, green, and red light in the light source device 100D are the same as those in the light source device 100A. However, in the light source device 100D, the fourth reflecting surface 174 of the reflector 131 is formed as a convex curved surface protruding towards the +X side. Therefore, the converging spot of the blue light LB7, which is focused on the second surface 146a of the wavelength conversion element 146, is defocused towards the +X side in the X direction. The amount of defocusing of the converging spot of the blue light LB7 varies depending on the radius of curvature of the fourth reflecting surface 174 and the separation distance between the fourth reflecting surface 174 and the first reflecting surface 171 in the Z direction.

[0143] The light source device 100D and the projector of the fifth embodiment described above have the same structure as the light source device 100A and the projector of the first embodiment, and therefore have the same function as the light source device 100A and the projector.

[0144] Furthermore, in the light source device 100D of the fifth embodiment, the reflector 131 has a fourth reflector 174 that reflects the blue light (first light) LB3 emitted from the first reflector 171 along the X direction toward the +X side, which is reflected by the synthesizing reflector 122. The fourth reflector 174 has a concave curved surface shape that is recessed toward the +X side, which is opposite to the incident side of the blue light LB3.

[0145] In the light source device 100D of the fifth embodiment, as described above, the fourth reflecting surface 174 has a concave curved surface shape that is recessed towards the +X side relative to the YZ plane. Therefore, in the light source device 100A of the first embodiment, which has a planar shape parallel to the YZ plane relative to the fourth reflecting surface, the defocusing of the converging spot of the blue light LB7 can be adjusted, and the illuminance deviation of the converging 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, by reducing the illuminance deviation of the converging spot of the blue light LB7 on the second surface 146a, the amount of blue light LB7 incident on the wavelength conversion element 146 can be increased. Furthermore, in the light source device 100D of the fifth embodiment, the deviation of the optical path and optical axis of the blue light LB6 from the optical path and optical axis of the green light LG2 in the thickness direction of the first reflector substrate and the dielectric multilayer film of the composite reflector 122 can be reduced. In the light source device 100D of the fifth embodiment, similar to the light source device 100C of the fourth embodiment, a reflector 131 is used instead of a lens, thus suppressing the generation of spherical aberration in the blue light LB5 to LB7.

[0146] The radius of curvature of the fourth reflective 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 converging spot of the blue light LB7 and the desired defocusing amount, and the separation distance between the fourth reflective surface 174 and the second surface 146a of the wavelength conversion element 146 in the X direction.

[0147] Furthermore, in the light source device 100B of the second embodiment and the light source device 100G of the third embodiment, the structure of the light source device 100D of the fifth embodiment can also be applied, so that the fourth reflecting surface 174 of the reflector 131 has a concave curved surface shape that is recessed towards the +X side. In such a structure, the same effect as that of the light source device 100D of the fifth embodiment can also be obtained.

[0148] [Sixth Implementation]

[0149] Next, use Figure 9 The sixth embodiment of the present invention will be described.

[0150] Figure 9 This is a structural diagram of the light source device 100E according to the sixth embodiment. Figure 9 As shown, the light source device 100E of the sixth embodiment is the same as the light source device 100C of the fourth embodiment and the light source device 100D of the sixth embodiment, having light source units 111, 113, 115, composite reflectors 122, 124 and reflector 131.

[0151] In the light source device 100E, the fourth reflecting surface 174 of the reflector 131 is bent with a predetermined radius of curvature, just like the fourth reflecting surface 174 of the reflector 131 in the light source device 100D. However, in the sixth embodiment, the surface that is in contact with the fourth reflecting surface 174 at the intersection of the optical axis of the blue light LB3 incident on the fourth reflecting surface 174 and the fourth reflecting surface 174 is tilted at an angle θt relative to the YZ plane, and moves from the +X side to the -X side as it moves from the -Z side to the +Z side.

[0152] The movement and travel paths of the blue, green, 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 reflector 131 has a convex curved surface shape that is inclined relative to the YZ plane and protrudes towards the +X side. Therefore, the centroid and light intensity distribution of the converged spot of the blue light LB7, which converges to the second surface 146a of the wavelength conversion element 146, change, and the converged spot of the blue light LB7 is defocused in the X direction. The degree of change in the centroid of the converged spot of the blue light LB7 and the amount of defocusing vary according to the radius of curvature of the fourth reflecting surface 174, the angle θt, and the separation distance between the fourth reflecting surface 174 and the first reflecting surface 171 in the Z direction.

[0153] The light source device 100E and the projector of the sixth embodiment described above have the same structure as the light source device 100A and the projector of the first embodiment, and therefore have the same function as the light source device 100A and the projector.

[0154] Furthermore, in the light source device 100E of the sixth embodiment, the fourth reflecting surface 174 of the reflector 131 has a concave curved surface shape that is recessed towards the +X side, opposite to the incident side of the blue light LB3, and is tilted overall relative to the YZ plane. According to the light source device 100E of the sixth embodiment, the light source device 100A of the first embodiment, which has a planar shape parallel to the YZ plane relative to the fourth reflecting surface, can coordinately adjust the centroid and defocusing amount of the converging spot of the blue light LB7. Therefore, according to the light source device 100E of the sixth embodiment, by adjusting the radius of curvature of the fourth reflecting surface 174 of the reflector 131 and the angle θt representing the degree of tilt of the fourth reflecting surface 174 relative to the YZ plane, the illuminance deviation of the blue light LB7 on the second surface 146a of the wavelength conversion element 146 can be efficiently reduced. According to the light source device 100E of the sixth embodiment, compared with the light source device 100C of the fourth embodiment and the light source device 100D of the fifth embodiment, it is able to illuminate a better area within the second surface 146a with blue light LB7, and efficiently increase the amount of blue light LB7 incident on the wavelength conversion element 146.

[0155] In the light source device 100E of the sixth embodiment, the fourth reflecting surface 174 of the reflector 131 has a concave curved surface shape and is tilted overall relative to the YZ plane as described above. This allows it to absorb deviations in the optical path and optical axis of blue light LB6 from those of green light LG2 in the thickness direction of the first reflector substrate and dielectric multilayer film of the composite reflector 122, as well as spherical aberration. Furthermore, in the light source device 100E of the sixth embodiment, similar to the light source device 100C of the fourth embodiment and the light source device 100D of the fifth embodiment, a reflector 131 is used instead of a lens, thus suppressing the generation of spherical aberration in the blue light LB5 to LB7.

[0156] Furthermore, in the light source device 100B of the second embodiment and the light source device 100G of the third embodiment, the structure of the light source device 100E of the sixth embodiment can also be applied, such that the fourth reflecting surface 174 of the reflector 131 is arranged obliquely relative to the YZ plane and has a concave curved surface shape recessed towards the +X side. With such a structure, the same effect as that of the light source device 100E of the sixth embodiment can also be obtained.

[0157] (Numerical example)

[0158] Next, the operation of the blue light LB7 spot light in the light source devices 100A, 100C, 100D, and 100E, and the simulation results related to the above-mentioned effects will be explained.

[0159] Figure 10 This is a graph showing the results of calculating the light intensity distribution of the converged spot of blue light LB7 illuminating the second surface 146a of the wavelength conversion element 146 of the light source device 100A using a simulation based on ray tracing. Figure 11 This is a graph showing the results of calculating the light intensity distribution of the convergent spot of blue light LB7 illuminating the second surface 146a of the wavelength conversion element 146 of the light source device 100B by simulating under the same conditions as when simulating the light source device 100A, except that the fourth reflective surface 174 is tilted at an angle θt relative to the YZ plane.

[0160] Figure 12 This is a diagram showing the result of calculating the light intensity distribution of the convergent spot of blue light LB7 illuminating the second surface 146a of the wavelength conversion element 146 of the light source device 100C by simulating under the same conditions as the simulation of the light source device 100A, except that the fourth reflective surface 174 has a concave curved surface shape that is recessed towards the +X side. Figure 13This is a diagram showing the result of calculating the light intensity distribution of the convergent spot of blue light LB7 illuminating the second surface 146a of the wavelength conversion element 146 of the light source device 100E by simulating under the same conditions as when simulating the light source device 100A, except that the fourth reflective surface 174 has a concave curved surface shape that is recessed towards the +X side and is tilted overall relative to the YZ plane.

[0161] In this simulation, the target area irradiated by blue light LB7 is defined as the entire second surface 146a of the wavelength conversion element 146, specifically as a rectangular region longer in the Y direction than in the Z direction. The Y-direction dimension of the second surface 146a of the wavelength conversion element 146 is set to 1.55 mm, and the Z-direction dimension is set to 1.2 mm. Figures 10-13 In the various figures, the dimension of the target region in the Y direction is represented as yB, and the dimension of the target region in the Z direction is represented as zB. Dimension yB is larger than dimension zB. Furthermore, in... Figures 10-13 In each figure, the light intensity distribution of the blue light LB7 in the Z direction on the second surface 146a of the wavelength conversion element 146 is represented as "z-profile", and the light intensity distribution of the blue light LB7 in the Y direction on the second surface 146a of the wavelength conversion element 146 is represented as "y-profile".

[0162] Reference Figures 10-13 It can be seen that, in the Y direction, the half-width of the intensity distribution of the blue light LB7 on the second surface 146a of the wavelength conversion element 146 is larger in the cases of light source devices 100D and 100E than in the cases of light source devices 100A and 100C. However, in the Y direction, in any of the cases of light source devices 100A, 100C, 100D, and 100E, the intensity distribution of the blue light LB7 expands approximately symmetrically to both positive and negative sides with the target region 0 (zero) as the center, and the centroid of the converging spot of the blue light LB7 is near 0.

[0163] On the other hand, refer to Figures 10-13 It can be seen that, in the Z direction, the half-width of the intensity distribution of the blue light LB7 on the second surface 146a of the wavelength conversion element 146 is larger in the cases of light source devices 100A and 100C than in the cases of light source devices 100D and 100E. For example... Figure 10 As shown, in the case of light source device 100A, in the Z direction, the rise of the negative region side of the light intensity distribution of blue light LB7, that is, the side closer to -Z than 0, is steeper than the rise of the positive region side of the distribution, that is, the side closer to +Z than 0. The centroid of the convergent spot of blue light LB7 is located at a position closer to -Z than 0.

[0164] like Figure 11As shown, in the case of light source device 100C, the fourth reflecting surface 174 is tilted relative to the YZ plane. Therefore, in the Z direction, the light intensity distribution of blue light LB7 is slightly expanded compared to light source device 100A, but remains approximately the same, and shifts overall towards the +Z side. That is, the centroid of the converging spot of blue light LB7 in the case of light source device 100C shifts towards the +Z side compared to the case of light source device 100A, and is close to 0. Based on this result, it is confirmed that by tilting the fourth reflecting surface 174 relative to the YZ plane, the light intensity distribution of the converging spot of blue light LB7 does not change significantly, and by making a slight adjustment to the centroid in the Z direction, the illuminance deviation of the converging spot of blue light LB7 is reduced.

[0165] like Figure 12 As shown, in the case of light source device 100D, the reflector 131 is concave and bent towards the +X side relative to the YZ plane. Therefore, in the Z direction, compared with the cases of light source devices 100A and 100C, the blue light LB7 is defocused, and the symmetry of the light intensity distribution of the blue light LB7 is improved. Figure 13 As shown, in the case of light source device 100E, the fourth reflective surface 174 is arranged obliquely relative to the YZ plane and is bent in a way that is concave towards the +X side relative to the YZ plane. Therefore, in the Z direction, through the multiplicative effect of the bending and obliqueness of the fourth reflective surface 174, the symmetry of the light intensity distribution of blue light LB7 is obtained in the same way as in the case of light source device 100D. Compared with the case of light source device 100D, the half-width of the convergent spot of blue light LB7 is reduced and the illuminance deviation is reduced.

[0166] based on Figures 10-13 Based on the light intensity distribution data in the Y and Z directions for each of the light source devices 100A, 100C, 100D, and 100E, the efficiency of blue light LB7 on the second surface 146a of the wavelength conversion element 146, the relative deviation of the center of gravity of blue light LB7 from the center O in the Z direction, and the relative deviation of the center of gravity of blue light LB7 from the center O in the Y direction were calculated. The aforementioned "efficiency" represents the percentage [%] of the amount of blue light LB7 incident on the second surface 146a of the wavelength conversion element 146 when the amount of blue light LB1 emitted from the first light source 141 of each light source device is set to 100%. Table 1 shows the calculated results for the efficiency, deviation from the center O in the Z direction, and deviation from the center O in the Y direction 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.

[0167] [Table 1]

[0168] efficiency[%] Deviation in the Z direction Deviation in the Y direction Light source device 100A 69.1 -0.0544 0.0005 Light source device 100C 68.5 -0.0017 0.0022 Light source device 100D 74.2 -0.0418 0.0014 Light source device 100E 73.8 -0.0049 0.0079

[0169] As shown in Table 1, in the light source device 100C, by tilting the fourth reflecting surface 174 relative to the YZ plane, the light intensity distribution of the converging spot of the blue light LB7 does not change significantly compared to the case of the light source device 100A. Instead, the position of the center of gravity is slightly adjusted in the Z direction. Therefore, the same level of efficiency as the case of the light source device 100A can be obtained, and the deviation from the center 0 in the Z and Y directions is suppressed to ±0.01 or less.

[0170] As shown in Table 1, in light source device 100D, by setting the shape of the fourth reflecting surface 174 to a concave curved surface shape that is recessed towards the +X side, the symmetry of the light intensity distribution of the blue light LB7 is improved compared to the case of light source device 100A, thus improving efficiency. In light source device 100E, by setting the fourth reflecting surface 174 to a concave curved surface shape that is inclined relative to the YZ plane and recessed towards the +X side, the same level of efficiency as in light source device 100C can be obtained, and the deviation from the center 0 in the Z and Y directions is suppressed to ±0.01 or less.

[0171] Based on the simulation results described above, it was confirmed that in light source devices 100A, 100C, 100D, and 100E, by tilting the fourth reflecting surface 174 of the reflector 131 relative to the YZ plane orthogonal to the optical axis of the incident blue light LB3, the position of the centroid of the convergent spot light of the blue light LB7 incident on the second surface 146a of the wavelength conversion element 146 can be finely adjusted, thereby reducing the illuminance deviation of the convergent spot light of the blue light LB7. Furthermore, it was confirmed that in light source devices 100A, 100C, 100D, and 100E, by forming the fourth reflecting surface 174 of the reflector 131 into a concave curved surface shape recessed towards the +X side, the symmetry of the light intensity distribution of the convergent spot light of the blue light LB7 can be improved, the illuminance deviation of the convergent spot light of the blue light LB7 can be reduced, and the efficiency can be improved.

[0172] As described in the fourth embodiment, the optical axis refraction of the blue light LB5 is approximately the same as the thickness of the synthesizing mirror 122, and the optical axis of the green light LG1 emitted from the wavelength conversion element 146 is offset in the YZ plane by an amount corresponding to the thickness of the synthesizing mirror 122. Due to manufacturing environment and processing conditions, the thickness of the synthesizing mirror 122 is difficult to be thinner than a specified value, and there is a substantial lower limit to its thickness. The illuminance deviation caused by the deviation of the optical axis of the blue light LB7 has a slight impact on the efficiency of the blue light LB7 incident on the wavelength conversion element 146 and the color balance of the white light WL when the size of the optical system of the light source device is large and the deviation of the optical axis is relatively small relative to the maximum beam width of the blue light LB7. In such cases, as in the light source device 100A, the fourth reflecting surface 174 of the mirror 131 may have a planar shape and be arranged parallel to the YZ plane.

[0173] However, for example, in the optical system envisioned in the numerical example above, when the deviation of the optical axis is large enough relative to the maximum beam width of the blue light LB7, the illuminance deviation of the blue light LB7 has a significant impact on the efficiency of the blue light LB7 incident on the wavelength conversion element 146 and the color balance of the white light WL. When the deviation of the optical axis is large enough relative to the maximum beam width of the blue lights LB7 and LB11, it is preferable, as in the light source devices 100C, 100D, and 100E, to adjust the tilt and curvature of the fourth reflecting surface 174 of the reflector 131 relative to the YZ plane, thereby adjusting the centroid of the converging spot of the blue light LB7 and the symmetry of the light intensity distribution, reducing the deviation of the optical axis of the blue light LB7, and suppressing the illuminance deviation.

[0174] Furthermore, as explained in the first embodiment, in order to capture more blue light LB1 emitted from the first light source 141 of the light source unit 111 using a pickup optical system 142 of a certain size, it is preferable that the beam diameter S1 of the blue light LB1 is small, and correspondingly, it is preferable that the size of the emitting area of ​​the first light source 141 is also small. Similarly, in order to capture more green light LG1 emitted from the wavelength conversion element 146 of the light source unit 113 using a pickup optical system 144 of a certain size, it is preferable that the size of the emitting area of ​​the wavelength conversion element 146, i.e., the second surface 146a, is also small. Therefore, as the projector 15 is miniaturized and the light source device 100A is required to be miniaturized, in order to ensure the amount of white light WL, it is required that the emitting area of ​​the first light source 141 and the second surface 146a of the wavelength conversion element 146 be further reduced. In this case, it is also considered that the deviation of the optical axis is large to a certain extent relative to the maximum beam width of the blue light LB7. Therefore, in miniaturizing the projector 15 compared to conventional projectors, it is preferable to appropriately employ the structures of the light source devices 100C, 100D, and 100E, such that the fourth reflecting surface 174 of the reflector 131 is tilted relative to the surface orthogonal to the optical axis of the blue light LB3, or the fourth reflecting surface 174 is a concave curved surface shape recessed to the side opposite to the incident side of the blue light LB3. This effectively reduces the illuminance deviation of the blue light LB7 on the second surface 146a of the wavelength conversion element 146, and increases 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.

[0175] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific embodiments described herein. Various modifications and alterations are possible within the scope of the spirit of the invention as set forth in the claims. Furthermore, the structural elements of multiple embodiments can be appropriately combined.

[0176] For example, the aforementioned light source device is used in projectors, but it can also be used in image display devices other than projectors that require good color balance of white light WL, as well as in image display devices and optical systems that require miniaturization.

[0177] The light source device according to the present invention may also have the following structure.

[0178] One aspect of the present invention comprises: a first light source emitting first light having a first wavelength; a second light source emitting second light; a wavelength conversion element having a first surface into which the second light emitted from the second light source is incident and a second surface facing the first surface, converting the second light into third light having a second wavelength different from the first wavelength; an optical component that combines the first light and the third light to emit combined light; and a reflecting component that reflects the first light emitted from the optical component toward the optical component, the first light reflected by the reflecting component being incident on the second surface of the wavelength conversion element via the optical component and converted into third light.

[0179] In one aspect of the light source device of the present invention, the optical component may transmit at least a portion of the incident first light and reflect at least a portion of the incident third light to generate composite light, and reflect another portion of the first light toward the reflective component.

[0180] In one aspect of the light source device of the present invention, the optical component may reflect at least a portion of the incident first light and transmit at least a portion of the incident third light to generate composite light, while another portion of the first light transmits toward the reflecting component.

[0181] In one embodiment of the light source device of the present invention, the reflecting member may have a reflecting surface that reflects the first light toward the optical member, the reflecting surface being inclined relative to a surface orthogonal to the optical axis of the first light.

[0182] In one embodiment of the light source device 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 has a concave curved surface shape that is recessed toward the side opposite to the incident side of the first light.

[0183] In one embodiment of the light source device of the present invention, an optical component may be disposed between the wavelength conversion element and the reflective component in a first direction, and a first light source and the optical component may be disposed at a distance from each other in a second direction orthogonal to the first direction. A second surface may be disposed on the side of the wavelength conversion element facing the reflective component in the first direction, and a second light source may be disposed on the opposite side of the side of the wavelength conversion element facing the reflective component in the first direction, overlapping the wavelength conversion element, the reflective component, and the optical component in the first direction.

[0184] In one embodiment of the light source device of the present invention, the first surface of the wavelength conversion element may abut against the emitting surface from which the second light is emitted from the second light source.

[0185] The projector of one embodiment of the present invention may also have the following structure.

[0186] One aspect of the present invention provides a projector comprising: the aforementioned light source device; a light modulation device that modulates light from the light source device according to image information, thereby forming image light; and a projection optical system that projects the image light.

Claims

1. A light source device, characterized in that, The light source device includes: The first light source emits first light with the first wavelength; The second light source emits a second beam of light; A wavelength conversion element having a first surface into which the second light emitted from the second light source is incident and a second surface opposite to the first surface, the wavelength conversion element converting the second light into a third light having a second wavelength different from the first wavelength; An optical component that combines the first light and the third light to emit a combined light; as well as A reflective component that reflects the first light emitted from the optical component as part of the first light emitted from the first light source toward the optical component. The first light, reflected by the reflective component, is incident on the second surface of the wavelength conversion element via the optical component and is converted into the third light. The reflective component has a reflective surface that reflects the first light toward the optical component. The reflecting surface has a concave curved surface shape that is recessed to the side opposite to the incident side of the first light.

2. The light source device according to claim 1, wherein, The reflecting surface is inclined relative to the surface orthogonal to the optical axis of the first light.

3. A light source device, characterized in that, The light source device includes: The first light source emits first light with the first wavelength; The second light source emits a second beam of light; A wavelength conversion element having a first surface into which the second light emitted from the second light source is incident and a second surface opposite to the first surface, the wavelength conversion element converting the second light into a third light having a second wavelength different from the first wavelength; An optical component that combines the first light and the third light to emit a combined light; as well as A reflective component that reflects the first light emitted from the optical component as part of the first light emitted from the first light source toward the optical component. The first light, reflected by the reflective component, is incident on the second surface of the wavelength conversion element via the optical component and is converted into the third light. The second light source, the wavelength conversion element, the optical component, and the reflective component are arranged in a straight line.

4. A light source device, characterized in that, The light source device includes: The first light source emits first light with the first wavelength; The second light source emits a second beam of light; A wavelength conversion element having a first surface into which the second light emitted from the second light source is incident and a second surface opposite to the first surface, the wavelength conversion element converting the second light into a third light having a second wavelength different from the first wavelength; An optical component that combines the first light and the third light to emit a combined light; as well as A reflective component that reflects the first light emitted from the optical component as part of the first light emitted from the first light source toward the optical component. The first light, reflected by the reflective component, is incident on the second surface of the wavelength conversion element via the optical component and is converted into the third light. The optical component is disposed along the first direction between the wavelength conversion element and the reflective component. The first light source is disposed separately from the optical component along a second direction orthogonal to the first direction. The second surface faces the side of the reflective component. The second light source is disposed on the side opposite to the reflective component relative to the wavelength conversion element, and overlaps with the wavelength conversion element, the reflective component, and the optical component in the first direction.

5. The light source device according to any one of claims 1 to 4, wherein, The optical component allows a portion of the incident first light to pass through and reflects at least a portion of the incident third light to generate the composite light, while another portion of the incident first light is reflected toward the reflective component.

6. The light source device according to any one of claims 1 to 4, wherein, The optical component reflects a portion of the incident first light and transmits at least a portion of the incident third light to generate the composite light, while another portion of the incident first light is transmitted toward the reflective component.

7. The light source device according to claim 3 or 4, wherein, The reflective component has a reflective surface that reflects the first light toward the optical component. The reflecting surface is inclined relative to the surface orthogonal to the optical axis of the first light.

8. The light source device according to claim 3 or 4, wherein, The reflective component has a reflective surface that reflects the first light toward the optical component. The reflective surface is inclined relative to the second surface of the wavelength conversion element.

9. The light source device according to any one of claims 1 to 4, wherein, The first surface of the wavelength conversion element abuts against the emitting surface from which the second light is emitted from the second light source.

10. A projector comprising: The light source device according to any one of claims 1 to 9; An optical modulation device that modulates light emitted from the light source device; and A projection optical system that projects light modulated by the light modulation device.

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