Light source device and projector

Abstract

A light source device and projector, wherein in the light source device having a reflective component, the fluorescence obtained by conversion by the phosphor is not excessively reabsorbed by the activator. The light source device includes: a light-emitting element that emits first light in a first wavelength band; a wavelength conversion component containing a phosphor that converts the first light into second light in a second wavelength band; and a reflective component that reflects the first light incident on the wavelength conversion component. The wavelength conversion component has a first surface and a second surface opposite to each other in a first direction, and a third surface and a fourth surface opposite to each other in a second direction intersecting the first direction. The second light is emitted from the first surface. The first light emitted from the light-emitting element is incident on the wavelength conversion component from the third surface. The reflective component is disposed opposite to the fourth surface. The concentration of the activator contained in the phosphor is the concentration required to absorb less than 98% of the incident light amount of the first light in the path from the third surface to the fourth surface.

Description

Technical Field

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

[0002] As a light source device used in projectors, a light source device that utilizes the fluorescence emitted from the phosphor when excitation light emitted from the light-emitting element is irradiated onto the phosphor is proposed.

[0003] Patent Document 1 discloses a light source apparatus comprising a solid-state light source emitting excitation light and a wavelength conversion component that converts the excitation light into fluorescence. Patent Document 1 describes that the concentration of the activator contained in the phosphor is typically selected such that all excitation light is absorbed in the path of the excitation light from the incident surface to the opposite surface, and under specific conditions, for example, 98% of the excitation light is absorbed. Furthermore, as a feature of the invention in Patent Document 1, it is described that by making the concentration of the activator more than three times the amount required to absorb 98% of the excitation light, the wavelength conversion efficiency is further increased.

[0004] Patent Document 1: Japanese Patent Publication No. 2017-526103

[0005] However, in the wavelength conversion component of the light source device in Patent Document 1, almost all of the excitation light is converted into fluorescence by the activator when it reaches the opposite side of the incident surface. Here, in the wavelength conversion component, if a reflective component is disposed on the surface opposite to the incident surface of the excitation light, almost all of the reflected light is converted into fluorescence. Therefore, various problems may occur, such as excessive reabsorption of the reflected fluorescence by the activator. Summary of the Invention

[0006] To address the aforementioned issues, one aspect of the present invention provides a light source device comprising: a light-emitting element that emits first light having a first wavelength band; a wavelength conversion component comprising a phosphor that converts the first light emitted from the light-emitting element into second light having a second wavelength band different from the first wavelength band; and a reflective component that reflects the first light incident on the wavelength conversion component. The wavelength conversion component has a first surface and a second surface opposite to each other in a first direction, and a third surface and a fourth surface opposite to each other in a second direction intersecting the first direction. The second light is emitted from the first surface. The first light emitted from the light-emitting element is incident on the wavelength conversion component from the third surface. The reflective component is disposed opposite to the fourth surface. The concentration of the activator contained in the phosphor is a concentration required to absorb less than 98% of the incident light amount of the first light in the path from the third surface to the fourth surface.

[0007] A projector according to one aspect of the present invention comprises: a light source device according to one aspect of the present invention; a light modulation device that modulates light including the second light from the light source device according to image information; and a projection optics device that projects the light modulated by the light modulation device. Attached Figure Description

[0008] Figure 1 This is a schematic structural diagram of the projector according to the first embodiment.

[0009] Figure 2 This is a schematic structural diagram of the first lighting device according to the first embodiment.

[0010] Figure 3 It is a graph showing the relationship between excitation light absorption rate and fluorescence emission.

[0011] Figure 4 This is a schematic structural diagram of the first lighting device according to the second embodiment.

[0012] Figure 5 It is along Figure 4 A cross-sectional view of the VV line light source device.

[0013] Label Explanation

[0014] 1: Projector; 4B, 4G, 4R: Light modulation device; 6: Projection optical device; 50: Wavelength conversion component; 50a: Surface 1; 50b: Surface 2; 50c: Surface 3; 50d: Surface 4; 50e: Surface 5; 50f: Surface 6; 54: Support component (reflective component); 54h: Groove; 54a: First wall surface; 54a1: First part; 54a2: Second part; 54b: Second wall surface; 54b3: Third part; 54b4: Fourth part; 54s: Reflective surface; 56: Light-emitting element; 58: First reflector (reflective component); 100, 105: Light source device; E, E1, E2: Excitation light (first light); Y: Fluorescence (second light). Detailed Implementation

[0015] [First Implementation]

[0016] The following uses Figures 1-3 The first embodiment of the present invention will be described.

[0017] The projector in this embodiment is an example of a projector that uses a liquid crystal panel as a light modulation device.

[0018] In the following figures, to facilitate observation of the structural elements, the scale of the dimensions is sometimes changed according to the structural elements.

[0019] Figure 1This is a diagram showing the schematic structure of the projector 1 in this embodiment.

[0020] like Figure 1 As shown, the projector 1 of this embodiment is a projection-type image display device that displays color images on a screen (projected surface) SCR. The projector 1 has three light modulation devices corresponding to each color of light: red light LR, green light LG, and blue light LB.

[0021] The projector 1 has a first illumination device 20, a second illumination device 21, a color separation optical system 3, a light modulation device 4R, a light modulation device 4G, a light modulation device 4B, a light combining element 5, and a projection optical device 6.

[0022] The first illumination device 20 emits yellow fluorescence Y toward the color separation optical system 3. The second illumination device 21 emits blue light LB toward the light modulation device 4B. The detailed structure of the first illumination device 20 and the second illumination device 21 will be described later.

[0023] The following description, in the accompanying drawings, will use an XYZ orthogonal coordinate system as needed. The Z-axis is the axis along the vertical direction of the projector 1. The X-axis is the axis parallel to the optical axis AX1 of the first illumination device 20 and the optical axis AX2 of the second illumination device 21. The Y-axis is the axis perpendicular to both the X-axis and the Z-axis. The optical axis AX1 of the first illumination device 20 is the central axis of the fluorescence Y emitted from the first illumination device 20. The optical axis AX2 of the second illumination device 21 is the central axis of the blue light LB emitted from the second illumination device 21.

[0024] The color separation optical system 3 separates the yellow fluorescence Y emitted from the first illumination device 20 into red light LR and green light LG. The color separation optical system 3 has a dichroic mirror 7, a first reflecting mirror 8a, and a second reflecting mirror 8b.

[0025] Dichroic mirror 7 separates the fluorescent Y light into red light LR and green light LG. Dichroic mirror 7 allows red light LR to pass through and reflects green light LG. A second reflector 8b is positioned in the optical path of the green light LG. The second reflector 8b reflects the green light LG, after being reflected by dichroic mirror 7, towards the optical modulation device 4G. A first reflector 8a is positioned in the optical path of the red light LR. The first reflector 8a reflects the red light LR, which has passed through dichroic mirror 7, towards the optical modulation device 4R.

[0026] On the other hand, the blue light LB emitted from the second lighting device 21 is reflected by the reflector 9 toward the light modulation device 4B.

[0027] The structure of the second lighting device 21 will be described below.

[0028] The second lighting device 21 includes a light source 81, a condenser lens 82, a diffuser plate 83, a rod lens 86, and a relay lens 87. The light source 81 is composed of at least one semiconductor laser. The light source 81 emits blue light LB composed of laser light. Alternatively, the light source 81 is not limited to a semiconductor laser, but may also be composed of an LED that emits blue light.

[0029] The condenser lens 82 is a convex lens. The condenser lens 82 causes the blue light LB emitted from the light source 81 to be incident on the diffuser plate 83 in a substantially convergent state. The diffuser plate 83 diffuses the blue light LB emitted from the condenser lens 82 with a predetermined diffusion degree, generating blue light LB having a substantially uniform light distribution distribution similar to the fluorescence Y emitted from the first illumination device 20. For example, frosted glass made of optical glass can be used as the diffuser plate 83.

[0030] Blue light LB, diffused by diffuser plate 83, is incident on rod lens 86. Rod lens 86 has a prismatic shape extending along the optical axis AX2 of the second illumination device 21. Rod lens 86 has a light incident end face 86a at one end and a light emitting end face 86b at the other end. Diffuser plate 83 is fixed to light incident end face 86a of rod lens 86 by optical adhesive (not shown). Preferably, the refractive index of diffuser plate 83 is as consistent as possible with the refractive index of rod lens 86.

[0031] Blue light LB propagates within the rod lens 86 via total internal reflection, thus exiting from the light exit facet 86b with improved uniformity of illuminance distribution. The blue light LB exiting the rod lens 86 then enters the relay lens 87. The relay lens 87 directs the blue light LB, with its improved illuminance distribution achieved through the rod lens 86, to the reflecting mirror 9.

[0032] The shape of the light-emitting end face 86b of the rod lens 86 is a rectangle that is approximately similar in shape to the image-forming area of ​​the light modulation device 4B. As a result, the blue light LB emitted from the rod lens 86 is efficiently incident on the image-forming area of ​​the light modulation device 4B.

[0033] Optical modulation device 4R modulates the red light LR according to the image information to form an image light corresponding to the red light LR. Optical modulation device 4G modulates the green light LG according to the image information to form an image light corresponding to the green light LG. Optical modulation device 4B modulates the blue light LB according to the image information to form an image light corresponding to the blue light LB.

[0034] The light modulation devices 4R, 4G, and 4B each use a transmissive liquid crystal panel, for example. Furthermore, polarizers (not shown) are disposed on the incident and emission sides of the liquid crystal panel. The polarizers allow only linearly polarized light in a specific direction to pass through.

[0035] A field lens 10R is disposed on the incident side of the optical modulation device 4R. A field lens 10G is disposed on the incident side of the optical modulation device 4G. A field lens 10B is disposed on the incident side of the optical modulation device 4B. The field lens 10R parallelizes the principal ray of the red light LR incident on the optical modulation device 4R. The field lens 10G parallelizes the principal ray of the green light LG incident on the optical modulation device 4G. The field lens 10B parallelizes the principal ray of the blue light LB incident on the optical modulation device 4B.

[0036] The light combining element 5 combines the image light corresponding to the red light LR, green light LG, and blue light LB by incident on the image light emitted from the light modulation devices 4R, 4G, and 4B, and then emits the combined image light toward the projection optical device 6. The light combining element 5 may be, for example, a cross-shaped dichroic prism.

[0037] The projection optics 6 consists of multiple projection lenses. The projection optics 6 magnifies and projects the image light synthesized by the light-combining element 5 toward the SCR screen. Thus, an image is displayed on the SCR screen.

[0038] The structure of the first lighting device 20 will be described below.

[0039] Figure 2 This is a schematic structural diagram of the first lighting device 20.

[0040] like Figure 2 As shown, the first illumination device 20 includes a light source device 100, a parallel optical system 63, an integrating optical system 70, a polarization conversion element 102, and an overlapping optical system 103.

[0041] The light source device 100 includes a wavelength conversion component 50, a light source unit 51, an angle conversion component 52, a first reflector 58, and a second reflector 53. The light source unit 51 includes a substrate 55 and a light-emitting element 56. In this embodiment, the first reflector 58 corresponds to the reflective component of the present invention.

[0042] The wavelength conversion component 50 has a quadrangular prism shape extending in the X-axis direction and has six faces. The side of the wavelength conversion component 50 extending in the X-axis direction is longer than the sides extending in the Y-axis direction and the Z-axis direction. Therefore, the X-axis direction corresponds to the length direction of the wavelength conversion component 50. The length of the side extending in the Y-axis direction is equal to the length of the side extending in the Z-axis direction. That is, the cross-sectional shape of the wavelength conversion component 50 obtained by cutting with a face perpendicular to the X-axis direction is square. Alternatively, the cross-sectional shape of the wavelength conversion component 50 obtained by cutting with a face perpendicular to the X-axis direction can also be rectangular.

[0043] The wavelength conversion component 50 has a first surface 50a and a second surface 50b, a third surface 50c and a fourth surface 50d, a fifth surface 50e and a sixth surface 50f. The first surface 50a and the second surface 50b intersect the length direction (X-axis direction) of the wavelength conversion component 50 and are located on opposite sides. The third surface 50c and the fourth surface 50d intersect the first surface 50a and the second surface 50b and are located on opposite sides in the Y-axis direction within an imaginary plane perpendicular to the length direction. The fifth surface 50e and the sixth surface 50f intersect the third surface 50c and the fourth surface 50d and are located on opposite sides in the Z-axis direction within an imaginary plane perpendicular to the length direction. In the following description, the third surface 50c, the fourth surface 50d, the fifth surface 50e and the sixth surface 50f are sometimes referred to as side surfaces. The X-axis direction of this embodiment corresponds to the first direction of the present invention. The Y-axis direction of this embodiment corresponds to the second direction of the present invention. The Z-axis direction in this embodiment corresponds to the third direction of the present invention.

[0044] The wavelength conversion component 50 includes at least a phosphor that converts excitation light E having a first wavelength band into fluorescence Y having a second wavelength band different from the first wavelength band. The excitation light E is incident on the wavelength conversion component 50 from the third surface 50c. The fluorescence Y is guided inside the wavelength conversion component 50 and then emitted from the first surface 50a. The excitation light E in this embodiment corresponds to the first light of the present invention. The fluorescence Y in this embodiment corresponds to the second light of the present invention.

[0045] The wavelength conversion component 50 includes a ceramic phosphor composed of a polycrystalline phosphor that converts the wavelength of the excitation light E into fluorescence Y. The second band of fluorescence Y is, for example, the yellow band of 490–750 nm. That is, fluorescence Y is a yellow fluorescence containing both red and green light components.

[0046] The wavelength conversion component 50 may also comprise a single-crystal phosphor instead of a polycrystalline phosphor. Alternatively, the wavelength conversion component 50 may be made of fluorescent glass. Alternatively, the wavelength conversion component 50 may be made of a material in which multiple phosphor particles are dispersed in a binder made of glass or resin. The wavelength conversion component 50 made of such a material converts the excitation light E into fluorescence Y.

[0047] Specifically, the material of the wavelength conversion component 50 may include, for example, a yttrium aluminum garnet (YAG) phosphor. Furthermore, the phosphor contains an activator that serves as the luminescence center. Taking YAG:Ce containing cerium (Ce) as an activator as an example, materials used as the material for the wavelength conversion component 50 may include materials obtained by mixing raw material powders containing constituent elements such as Y₂O₃, Al₂O₃, and CeO₃ and then 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 particles obtained by gas-phase methods such as spray drying, flame thermal decomposition, or thermal plasma methods.

[0048] The concentration of the activator, such as cerium, contained in the phosphor is less than 98% of the incident light quantity of the excitation light E from the third surface 50c to the fourth surface 50d. Preferably, it is set to a concentration required to absorb less than 98% and more than 30% of the light quantity. Furthermore, the concentration of the activator is more preferably a concentration required to absorb less than 92% and more than 40% of the incident light quantity of the excitation light E in the aforementioned path. The reason for setting the concentration of the activator within the above range will be explained later.

[0049] The light source unit 51 includes a light-emitting element 56, which has a light-emitting surface 56a that emits excitation light E in a first wavelength band. The light-emitting element 56 is, for example, a light-emitting diode (LED). The light-emitting surface 56a of the light-emitting element 56 faces the third surface 50c of the wavelength conversion member 50, and emits the excitation light E toward the third surface 50c. The first wavelength band is, for example, a blue to violet band from 400 nm to 480 nm, with a peak wavelength of, for example, 445 nm. Thus, the light source unit 51 is disposed opposite one of the four sides along the length of the wavelength conversion member 50.

[0050] The substrate 55 supports the light-emitting element 56. The light-emitting element 56 is provided on one side 55a of the substrate 55. In this embodiment, the light source unit 51 is composed of the light-emitting element 56 and the substrate 55, but in addition, it may also include other optical components such as a light guide plate, a diffuser plate, and a lens. In addition, two light-emitting elements 56 are used in this embodiment, but the number of light-emitting elements 56 is not particularly limited.

[0051] The first reflector 58 is disposed opposite to the fourth surface 50d of the wavelength conversion member 50. The first reflector 58 preferably abuts against the fourth surface 50d of the wavelength conversion member 50 without passing through an air layer or the like. The first reflector 58 reflects the excitation light E incident on the wavelength conversion member 50. The reflectivity of the first reflector 58 is preferably as high as possible. Specifically, the reflectivity of the first reflector 58 is preferably 75% or more, more preferably 90% or more. The first reflector 58 is, for example, made of a metal material with high reflectivity such as aluminum or silver. Furthermore, the first reflector 58 preferably has a higher thermal conductivity than the wavelength conversion member. Alternatively, the first reflector 58 may be made of a dielectric multilayer film instead of a metal material.

[0052] The second reflector 53 is disposed opposite to the second surface 50b of the wavelength conversion component 50. The second reflector 53 reflects the fluorescent Y-rays that are guided inside the wavelength conversion component 50 to reach the second surface 50b. The second reflector 53 is composed of a metal film or a dielectric multilayer film formed on the second surface 50b of the wavelength conversion component 50.

[0053] In the first illumination device 20, when the excitation light E emitted from the light source 51 is incident on the wavelength conversion member 50, the phosphor contained inside the wavelength conversion member 50 is excited and emits fluorescence Y from any light-emitting point. The fluorescence Y travels in all directions from the arbitrary light-emitting point, and the fluorescence Y toward the four sides 50c, 50d, 50e, and 50f undergoes repeated total internal reflection at multiple locations on the sides 50c, 50d, 50e, and 50f, and travels toward either the first surface 50a or the second surface 50b. The fluorescence Y traveling toward the first surface 50a is incident on the angle conversion member 52. The fluorescence Y traveling toward the second surface 50b is reflected by the second reflector 53 and travels toward the first surface 50a.

[0054] A portion of the excitation light E incident on the wavelength conversion member 50 that is not used to excite the phosphor is reflected by components surrounding the wavelength conversion member 50, including the light-emitting element 56 of the light source unit 51, or by the second reflector 53 disposed on the second surface 50b. Therefore, a portion of the excitation light E is enclosed inside the wavelength conversion member 50 and reused.

[0055] An angle conversion component 52 is disposed on the light-emitting side of the first surface 50a of the wavelength conversion component 50. The angle conversion component 52 is, for example, a tapered rod. The angle conversion component 52 has a light-incident surface 52a for the fluorescence Y emitted from the wavelength conversion component 50 to be incident, a light-emitting surface 52b for emitting the fluorescence Y, and a side surface 52c for reflecting the incident fluorescence Y toward the light-emitting surface 52b.

[0056] The angle conversion component 52 has a frustum-shaped quadrangular pyramid, and its cross-sectional area perpendicular to the optical axis J extends along the direction of light propagation. Therefore, the area of ​​the light emitting surface 52b is larger than the area of ​​the light incident surface 52a. The optical axis J of the angle conversion component 52 is defined as the axis passing through the center of both the light emitting surface 52b and the light incident surface 52a and parallel to the X-axis. Furthermore, the optical axis J of the angle conversion component 52 coincides with the optical axis AX1 of the first illumination device 20.

[0057] During its journey inside the angle conversion member 52, the fluorescence Y incident on the angle conversion member 52 changes its orientation in a direction nearly parallel to the optical axis J whenever it undergoes total internal reflection at the side 52c. In this way, the angle conversion member 52 converts the emission angle distribution of the fluorescence Y emitted from the first surface 50a of the wavelength conversion member 50. Specifically, the angle conversion member 52 makes the maximum emission angle of the fluorescence Y on the light emission surface 52b smaller than the maximum incident angle of the fluorescence Y on the light incident surface 52a.

[0058] Typically, the optical spread of light is preserved by the product of the area of ​​the light-emitting region and the solid angle of the light (maximum emission angle). Therefore, the optical spread of fluorescence Y is preserved both before and after transmission through the angle conversion member 52. As described above, the angle conversion member 52 has a structure in which the area of ​​the light-emitting surface 52b is larger than the area of ​​the light-incident surface 52a. Therefore, from the viewpoint of preserving optical spread, the angle conversion member 52 can make the maximum emission angle of fluorescence Y in the light-emitting surface 52b smaller than the maximum incident angle of fluorescence Y incident on the light-incident surface 52a.

[0059] Angle conversion component 52 is fixed to wavelength conversion component 50 via optical adhesive (not shown) with light incident surface 52a facing the first surface 50a of wavelength conversion component 50. That is, angle conversion component 52 and wavelength conversion component 50 are in contact via optical adhesive, and no gap (air layer) is provided between them. If a gap were provided between angle conversion component 52 and wavelength conversion component 50, fluorescence Y reaching the light incident surface 52a at an angle greater than the critical angle would be totally internally reflected at the light incident surface 52a and would not be able to reach angle conversion component 52. In contrast, as in this embodiment, without a gap between angle conversion component 52 and wavelength conversion component 50, the amount of fluorescence Y that cannot reach angle conversion component 52 can be reduced. From this viewpoint, it is preferable to make the refractive index of angle conversion component 52 as similar as possible to the refractive index of wavelength conversion component 50.

[0060] As the angle conversion component 52, a compound parabolic concentrator (CPC) can be used instead of a tapered rod. Even when using a CPC as the angle conversion component 52, the same effect as when using a tapered rod can be obtained. Furthermore, the light source device 100 may not necessarily have an angle conversion component 52.

[0061] A parallelizing optical system 63, composed of a collimating lens or the like, is provided between the light source device 100 and the integrating optical system 70. The parallelizing optical system 63 further reduces the angular distribution of the fluorescence Y emitted from the angle conversion member 52, allowing the fluorescence Y with high parallelism to enter the integrating optical system 70. Alternatively, if the parallelism of the fluorescence Y emitted from the angle conversion member 52 is sufficiently high, the parallelizing optical system 63 may not be required.

[0062] The integrating optical system 70 has a first lens array 61 and a second lens array 101. Together with the overlapping optical system 103, the integrating optical system 70 functions as a uniform illumination optical system, which homogenizes the intensity distribution of fluorescence Y emitted from the light source device 100 across the various light modulation devices 4R and 4G in the illuminated area. Fluorescence Y emitted from the parallelization optical system 63 is incident on the first lens array 61. The first lens array 61, together with the second lens array 101 located after the light source device 100, constitutes the integrating optical system 70.

[0063] The first lens array 61 has a plurality of first microlenses 61a. The plurality of first microlenses 61a are arranged in a matrix in a plane parallel to the YZ plane perpendicular to the optical axis AX1 of the first illumination device 20. The plurality of first microlenses 61a divide the fluorescence Y emitted from the angle conversion member 52 into multiple partial beams. Each of the first microlenses 61a has a rectangular shape that is approximately similar in shape to the image forming areas of the light modulation devices 4R and 4G. Thus, the partial beams emitted from the first lens array 61 are efficiently incident on the image forming areas of the light modulation devices 4R and 4G, respectively.

[0064] The fluorescence Y emitted from the first lens array 61 travels toward the second lens array 101. The second lens array 101 is arranged opposite to the first lens array 61. The second lens array 101 has a plurality of second small lenses 101a corresponding to the plurality of first small lenses 61a of the first lens array 61. Together with the overlapping optical system 103, the second lens array 101 images the images of the plurality of first small lenses 61a of the first lens array 61 onto the vicinity of the image forming areas of the light modulation devices 4R and 4G, respectively. The plurality of second small lenses 101a are arranged in a matrix in a plane parallel to the YZ plane perpendicular to the optical axis AX1 of the first illumination device 20.

[0065] In this embodiment, each of the first microlenses 61a of the first lens array 61 and each of the second microlenses 101a of the second lens array 101 have the same size as each other, but they may also have different sizes. Furthermore, in this embodiment, the first microlenses 61a of the first lens array 61 and the second microlenses 101a of the second lens array 101 are arranged at positions aligned with each other's optical axes, but they may also be arranged in a state of being off-center from each other.

[0066] The polarization conversion element 102 converts the polarization direction of the fluorescence Y emitted from the second lens array 101. Specifically, the polarization conversion element 102 converts the portions of the fluorescence Y beam that are divided by the first lens array 61 and emitted from the second lens array 101 into linearly polarized light.

[0067] The polarization conversion element 102 includes: a polarization separation layer (not shown), which allows one of the linearly polarized components of the fluorescence Y emitted from the light source device 100 to pass directly through and reflects the other linearly polarized component in a direction perpendicular to the optical axis AX1; a reflection layer (not shown), which reflects the other linearly polarized component reflected by the polarization separation layer in a direction parallel to the optical axis AX1; and a phase difference plate (not shown), which converts the other linearly polarized component reflected by the reflection layer into one linearly polarized component.

[0068] [Studies related to activator concentration]

[0069] In order to increase the amount of fluorescence emitted from the wavelength conversion component, the inventors investigated the concentration of the activator contained in the phosphor. To improve wavelength conversion efficiency, as described in Patent Document 1 above, when excitation light is incident from one incident surface of the wavelength conversion component, a general idea is to pre-introduce a large amount of activator into the phosphor to absorb as much excitation light as possible during the period until the excitation light reaches the surface opposite to the incident surface. The rationale is that if a large amount of excitation light remains unabsorbed when the excitation light reaches the surface opposite to the incident surface, this excitation light leaks to the outside, reducing the wavelength conversion efficiency.

[0070] However, the inventors realized that increasing the concentration of the activator in order to absorb more excitation light would cause the following three problems.

[0071] As the first problem, the activator also acts as a scattering source of light propagating inside the wavelength conversion component. Therefore, with a high activator concentration, the amount of scattering of excitation light and fluorescence propagating inside the wavelength conversion component increases, and compared to a low activator concentration, excitation light and fluorescence are more likely to leak from the sides of the wavelength conversion component. Consequently, it is difficult to emit a large amount of fluorescence from the emission surface of the wavelength conversion component.

[0072] As a second problem, for example, when excitation light in the blue band is converted to fluorescence in the yellow band, there is a phenomenon where the short-wavelength component of the fluorescence, i.e., the component in the yellow band close to the blue band, is self-absorbed by the activator and subsequently converted into a long-wavelength component. Therefore, when the activator concentration is high, the effect of fluorescence self-absorption cannot be ignored, and the fluorescence spectrum shifts towards the long-wavelength side. As a result, it is difficult to obtain fluorescence with the desired hue.

[0073] As a third problem, a portion of the energy of the excitation light absorbed by the activator is converted into fluorescence, while the remainder is converted into heat. Therefore, with a high concentration of activator, a large amount of heat is generated near the incident surface of the excitation light, while less heat is generated near the surface opposite to the incident surface. Consequently, the temperature distribution inside the wavelength conversion component becomes uneven, reducing the wavelength conversion efficiency and making it difficult to obtain a large amount of fluorescence.

[0074] To solve the aforementioned problems, simply reducing the amount of activator is sufficient. However, if only the amount of activator is reduced, as mentioned above, the following problem arises: excitation light that is not absorbed when it reaches the surface opposite to the incident surface leaks to the outside. Therefore, the inventors devised the following technical idea: reducing the amount of activator and providing a reflective component on the surface opposite to the incident surface, so that the excitation light that is not absorbed when it reaches the opposite surface is reflected by the reflective component, and is then absorbed again by the activator inside the wavelength conversion component. The aforementioned reflective component corresponds to the first reflector of this embodiment.

[0075] Therefore, in order to verify the above-mentioned technical concept, the inventors prepared samples of various wavelength conversion components with different concentrations of activator and conducted an experiment to measure the amount of fluorescence emitted from the emission surface (the first surface 50a of the above embodiment) of the wavelength conversion component in each sample.

[0076] The following is a description of the experimental procedure.

[0077] The concentration of the activator needs to be appropriately determined based on various parameters such as the size of the wavelength conversion component, the cooling efficiency when cooling the wavelength conversion component, and the desired fluorescence spectrum. Here, the concentration of the activator for each sample is not expressed as the concentration value itself, but rather as the proportion of excitation light absorbed from the point of incidence to the surface opposite to the point of incidence. That is, the absorptivity of the excitation light corresponds to the concentration of the activator; the higher the concentration of the activator, the higher the absorptivity of the excitation light, and the lower the concentration of the activator, the lower the absorptivity of the excitation light. Hereinafter, the absorptivity of the excitation light will be defined as the ratio of the amount of excitation light absorbed to the amount of incident excitation light along the path from the incident surface (the third surface 50c in the above embodiment) to the surface opposite to the incident surface (the fourth surface 50d in the above embodiment).

[0078] To determine the absorptivity of the excitation light, a light-emitting element is positioned opposite the third surface of the wavelength conversion component, and a power meter is positioned opposite the fourth surface of the wavelength conversion component. However, no reflective element is positioned opposite the fourth surface of the wavelength conversion component when determining the absorptivity of the excitation light. A predetermined amount of excitation light is incident on the wavelength conversion component from the normal direction of the third surface, and the amount of excitation light emitted from the fourth surface is measured using the power meter. With the amount of excitation light incident on the third surface defined as P1 and the amount of excitation light emitted from the fourth surface defined as P2, the absorptivity K (%) is determined using K = [(P1-P2) / P1] × 100. On the other hand, regarding the fluorescence emitted from the wavelength conversion component, a power meter with an integrating sphere is positioned opposite the first surface of the wavelength conversion component, and the amount of fluorescence is measured using the power meter. Furthermore, the concentration of the activator contained in the wavelength conversion component can be measured using inductively coupled plasma (ICP) method.

[0079] According to the above embodiment, YAG:Ce containing cerium (Ce) is used as the activator for the wavelength conversion component. Regarding the dimensions of the wavelength conversion component, the length (distance between the first and second surfaces) is set to 60 mm, the thickness (distance between the third and fourth surfaces) is set to 1.2 mm, and the width (distance between the fifth and sixth surfaces) is set to 1.6 mm.

[0080] As Example 1, a wavelength conversion component with an excitation light absorptivity of 75% and a reflectivity of 90% for the reflecting component was fabricated. As Example 2, a wavelength conversion component with an excitation light absorptivity of 75% and a reflectivity of 75% for the reflecting component was fabricated. As Example 3, a wavelength conversion component with an excitation light absorptivity of 50% and a reflectivity of 90% for the reflecting component was fabricated. As Example 4, a wavelength conversion component with an excitation light absorptivity of 40% and a reflectivity of 90% for the reflecting component was fabricated. As Example 5, a wavelength conversion component with an excitation light absorptivity of 20% and a reflectivity of 90% for the reflecting component was fabricated. In contrast, as a comparative example, a wavelength conversion component with an excitation light absorptivity of 98% and a reflectivity of 90% for the reflecting component was fabricated.

[0081] The absorptivity of the excitation light, the reflectivity of the reflective component, and the amount of fluorescence emitted for each sample are shown in Table 1 below. Furthermore, the amount of fluorescence emitted is expressed as a relative value when the amount of fluorescence emitted in the comparative example sample is set to 100.

[0082] [Table 1]

[0083] Example 1 Example 2 Example 3 Example 4 Example 5 Comparative example Absorption rate of excitation light (%) 75 75 50 40 20 98 Reflectivity (%) of the reflective component 90 75 90 90 90 90 Fluorescence emission (relative value) 140 180 150 110 90 100

[0084] As shown in Table 1, in Example 1, where the excitation light absorption rate was reduced to 75%, the fluorescence emission amount increased to 140 compared to the comparative example. In Example 2, the reflectivity of the reflective component was reduced compared to Example 1, thus decreasing the fluorescence emission amount compared to Example 1, but still increasing to 130 compared to the comparative example. In Example 3, where the excitation light absorption rate was reduced to 50%, the fluorescence emission amount further increased to 150. In Example 4, where the excitation light absorption rate was reduced to 40%, the fluorescence emission amount was 110, decreasing compared to Example 3, but increasing compared to the comparative example. In Example 5, where the excitation light absorption rate was reduced to 20%, the fluorescence emission amount decreased to 90% compared to the comparative example.

[0085] Compared to the comparative example, which had an activator concentration that absorbed almost all of the incident excitation light along its path from the third surface to the fourth surface, the activator concentration was reduced to within the range of 20% to 75%. Therefore, in Examples 1-5, the main issues such as light scattering, self-absorption, and uneven temperature distribution in the wavelength conversion component were improved. Furthermore, as shown in Table 1, the fluorescence emission amount was increased in Examples 1-4. In Example 5, where the activator concentration was reduced to 20%, it is speculated that the activator concentration was too low, and the excitation light was not sufficiently absorbed, thus the fluorescence emission amount did not increase.

[0086] Figure 3 This is a graph showing the relationship between excitation light absorption and fluorescence emission for samples other than those in Example 2, where the reflectivity of the reflective components differs. Figure 3 In the figure, the horizontal axis represents the excitation light absorption rate (%), and the vertical axis represents the fluorescence emission amount (relative value).

[0087] like Figure 3 As shown, decreasing the excitation light absorbance from 98% reveals an increasing trend in fluorescence emission. Based on these results, the fluorescence emission is maximized when the excitation light absorbance is set to 50%, and decreases as the absorbance decreases. At an excitation light absorbance of 30%, the fluorescence emission is 100%, and below 30%, the fluorescence emission is less than that of the comparative sample.

[0088] That is, if the activator concentration is set to absorb approximately half of the incident excitation light along the path from the third surface to the fourth surface, then during the time the excitation light reflected from the fourth surface re-enters the third surface, more of the excitation light is absorbed, and less of the remaining excitation light is emitted from the third surface to the outside, which is presumably conducive to increasing the amount of fluorescence emitted. Therefore, it can be seen that if the activator concentration is the concentration required to absorb less than 98% but more than 30% of the incident excitation light along the path from the third surface to the fourth surface, then compared to the case where the activator concentration is set to absorb approximately all of the incident excitation light, the amount of fluorescence emitted from the first surface of the wavelength conversion unit can be increased.

[0089] [Effects of the first embodiment]

[0090] The light source device 100 of this embodiment includes: a light-emitting element 56 that emits excitation light E; a wavelength conversion member 50 that includes a phosphor and converts the excitation light E emitted from the light-emitting element 56 into fluorescence Y; and a first reflector 58 that reflects the excitation light E incident on the wavelength conversion member 50. The wavelength conversion member 50 has a first surface 50a and a second surface 50b that are opposite to each other in the X-axis direction, and a third surface 50c and a fourth surface 50d that are opposite to each other in the Y-axis direction. Fluorescence Y is emitted from the first surface 50a. The excitation light E emitted from the light-emitting element 56 is incident on the wavelength conversion member 50 from the third surface 50c. The first reflector 58 is disposed opposite to the fourth surface 50d. The concentration of the activator included in the phosphor is the concentration required to absorb less than 98% of the incident light amount of the excitation light E in the path from the third surface 50c to the fourth surface 50d.

[0091] As described above, according to this structure, compared to conventional structures with an activator concentration that absorbs approximately all incident excitation light, even the structure including the first reflector 58 can reduce light scattering and self-absorption in the wavelength conversion component 50. Furthermore, although not confirmed in the aforementioned experiments, by lowering the activator concentration than before, it is possible to suppress excessive shift of the fluorescence Y spectrum towards the longer wavelength side, thus obtaining fluorescence Y with the desired hue.

[0092] In the light source device 100 of this embodiment, the concentration of the activator contained in the phosphor is the concentration required to absorb more than 30% of the amount of incident light E in the path from the excitation light E incident from the third surface 50c to the fourth surface 50d.

[0093] According to this structure, in the structure including the first reflector 58, light scattering and self-absorption within the wavelength conversion component 50 can be reduced, thereby increasing the amount of fluorescent Y emitted from the first surface 50a of the wavelength conversion component 50.

[0094] In the light source device 100 of this embodiment, the reflectivity of the first reflector 58 is 75% or higher. Based on this structure, as shown in Table 1, the amount of fluorescent Y light can be reliably increased within the concentration range of the activator described above.

[0095] In the light source device 100 of this embodiment, the reflectivity of the first reflector 58 is 90% or higher. Based on this structure, as shown in Table 1, the amount of fluorescent Y light can be increased more reliably within the concentration range of the activator described above.

[0096] In the light source device 100 of this embodiment, the concentration of the activator is the concentration required to absorb 92% or less and 40% or more of the incident light amount of the excitation light E in the above-described path.

[0097] According to this structure, such as Figure 3 As shown, compared with the previous structure, it can increase the amount of fluorescent Y light by more than 10%, and achieve significant results.

[0098] The projector 1 of this embodiment has the light source device 100 of this embodiment, and therefore can obtain a bright image with excellent color reproduction.

[0099] [Second Implementation]

[0100] The following uses Figure 4 and Figure 5 The second embodiment of the present invention will be described.

[0101] The basic structure of the projector and light source device in the second embodiment is the same as that in the first embodiment, so the description of the basic structure of the projector and light source device is omitted.

[0102] Figure 4 This is a schematic structural diagram of the first lighting device 25 in the second embodiment. Figure 5 It is along Figure 4 A cross-sectional view of the VV-line light source device 105. Figure 4 and Figure 5 In this document, structural elements that are the same as those used in the drawings of the first embodiment are labeled with the same reference numerals, and descriptions are omitted.

[0103] like Figure 4 As shown, the light source device 105 of this embodiment includes a wavelength conversion member 50, a light source unit 51, an angle conversion member 52, a support member 54, and a second reflector 53. The support member 54 of this embodiment corresponds to the reflector of the present invention.

[0104] The support member 54 is arranged to surround the wavelength conversion member 50. The support member 54 supports the wavelength conversion member 50 and allows heat generated by the wavelength conversion member 50 to diffuse outwards. Therefore, the support member 54 is preferably made of a material with a specified strength and high thermal conductivity. For example, metals such as aluminum and stainless steel are used as materials for the support member 54, and aluminum alloys such as 6061 series are particularly preferred. Furthermore, the support member 54 functions as a reflective member to reflect the excitation light E incident on the wavelength conversion member 50.

[0105] like Figure 5 As shown, the support member 54 has a groove 54h that extends along the length direction (X-axis direction) of the wavelength conversion member 50 and houses the wavelength conversion member 50. The support member 54 has a U-shaped cross-section perpendicular to the X-axis direction due to the groove 54h. The groove 54h has a reflective surface 54s, a first wall surface 54a, and a second wall surface 54b.

[0106] The reflecting surface 54s corresponds to the bottom surface of the groove 54h and abuts against the fourth surface 50d of the wavelength conversion member 50. The reflecting surface 54s extends parallel to the XZ plane. The first wall surface 54a corresponds to one side surface of the groove 54h, and is opposite to and separate from the fifth surface 50e of the wavelength conversion member 50. The second wall surface 54b corresponds to the other side surface of the groove 54h, and is opposite to and separate from the sixth surface 50f of the wavelength conversion member 50. That is, a gap S1 is provided between the first wall surface 54a and the fifth surface 50e of the wavelength conversion member 50. A gap S1 is also provided between the second wall surface 54b and the sixth surface 50f of the wavelength conversion member 50.

[0107] The first wall surface 54a has a first portion 54a1 located on the side of the third surface 50c and a second portion 54a2 located on the side of the reflecting surface 54s. The first portion 54a1 extends parallel to the XY plane with respect to the direction perpendicular to the reflecting surface 54s. The second portion 54a2 is inclined in such a way that it approaches the fifth surface 50e from the side of the first portion 54a1 toward the side of the reflecting surface 54s. In other words, the distance between the second portion 54a2 on the side of the reflecting surface 54s and the fifth surface 50e is less than the distance between the second portion 54a2 on the side of the first portion 54a1 and the fifth surface 50e.

[0108] The second wall surface 54b has a third portion 54b3 located on the side of the third surface 50c and a fourth portion 54b4 located on the side of the reflecting surface 54s. The third portion 54b3 extends parallel to the direction perpendicular to the reflecting surface 54s, i.e., the XY plane. The fourth portion 54b4 is inclined in such a way that it approaches the sixth surface 50f from the side of the third portion 54b3 toward the side of the reflecting surface 54s. In other words, the distance between the fourth portion 54b4 on the side of the reflecting surface 54s and the sixth surface 50f is less than the distance between the fourth portion 54b4 on the side of the third portion 54b3 and the sixth surface 50f.

[0109] The reflective surface 54s, the first wall surface 54a, and the second wall surface 54b are each made of the surface of a metal such as aluminum or stainless steel, which is the constituent material of the supporting member 54. More specifically, the reflective surface 54s, the first wall surface 54a, and the second wall surface 54b are each made of a machined surface on which the aforementioned metal surfaces have undergone mirror finishing. Therefore, the reflective surface 54s, the first wall surface 54a, and the second wall surface 54b are each light-reflective, reflecting the incident excitation light E. Furthermore, the reflective surface 54s, the first wall surface 54a, and the second wall surface 54b may also be made of other metal films or dielectric multilayer films formed on the surface of metals such as aluminum or stainless steel.

[0110] The dimension W1 of the emitting surface 56a of the light-emitting element 56 along the Z-axis is larger than the dimension W2 of the wavelength conversion component 50 along the Z-axis. Therefore, in the Z-axis direction, both ends of the emitting surface 56a of the light-emitting element 56 extend outwards from the third surface 50c of the wavelength conversion component 50. Specifically, both ends of the emitting surface 56a of the light-emitting element 56 extend to positions overlapping with the gap S1 between the fifth surface 50e and the first wall surface 54a, and the gap S1 between the sixth surface 50f and the second wall surface 54b. In other words, when the emitting surface 56a is viewed from the reflecting surface 54s along the Y-axis, a portion of the emitting surface 56a overlaps with the third surface 50c, and another portion overlaps with the gap S1 between the fifth surface 50e and the first wall surface 54a, and the gap S1 between the sixth surface 50f and the second wall surface 54b.

[0111] Furthermore, when the position where the excitation light E1, which exits from the -Z side end of the light-emitting surface 56a and travels towards the first wall surface 54a through the corner of the +Z side of the third surface 50c of the wavelength conversion member 50, is incident on the first wall surface 54a is set to P1, the distance from the end of the first wall surface 54a on the -Y side to position P1 is set to T1. In this case, it is preferable that the dimension T2 of the first portion 54a1 along the Y-axis direction is at least larger than the distance T1.

[0112] The dimension W3 of the reflecting surface 54s of the support member 54 along the Z-axis is larger than the dimension W2 of the wavelength conversion member 50 along the Z-axis. Therefore, in the Z-axis direction, both ends of the reflecting surface 54s extend outwards from the fourth surface 50d of the wavelength conversion member 50. In other words, when the reflecting surface 54s is viewed from the emitting surface 56a along the Y-axis, a portion of the reflecting surface 54s overlaps with the fourth surface 50d, while another portion of the reflecting surface 54s is exposed outwards from the fourth surface 50d. Thus, the reflecting surface 54s has an exposed portion 54r that protrudes outwards from the wavelength conversion member 50.

[0113] The other structures of the light source device are the same as those of the light source device in the first embodiment.

[0114] [Effects of the second implementation method]

[0115] In the light source device 105 of this embodiment, the same effects as in the first embodiment can also be obtained: light scattering and self-absorption in the wavelength conversion member 50 can be reduced, the amount of fluorescent Y emitted from the first surface 50a of the wavelength conversion member 50 can be increased, the spectral shift of fluorescent Y can be suppressed, and fluorescent Y with the desired hue can be obtained.

[0116] Furthermore, the light source device 105 of this embodiment includes a support member 54 that supports the wavelength conversion member 50. The support member 54 abuts against the fourth surface 50d of the wavelength conversion member 50 and has a reflective surface 54s that reflects the excitation light E incident from the third surface 50c.

[0117] According to this structure, the wavelength conversion component 50 is supported by the support component 54, and the heat generated by the wavelength conversion component 50 is released to the outside through the support component 54, thereby suppressing the temperature rise of the wavelength conversion component 50. As a result, the decrease in wavelength conversion efficiency as the temperature of the wavelength conversion component 50 rises can be suppressed, and thus the amount of fluorescent Y light emitted from the first surface 50a of the wavelength conversion component 50 can be stably maintained.

[0118] In the light source device 105 of this embodiment, the support member 54 has a groove 54h for accommodating the wavelength conversion member 50. The groove 54h has a reflective surface 54s, a first wall surface 54a opposite to the fifth surface 50e, and a second wall surface 54b opposite to the sixth surface 50f. The fifth surface 50e and the first wall surface 54a are separated from each other, and the sixth surface 50f and the second wall surface 54b are separated from each other.

[0119] According to this structure, the excitation light E emitted from the light-emitting element 56 is incident not only from the third surface 50c of the wavelength conversion component 50, but also from the fifth surface 50e and the sixth surface 50f. As a result, the utilization efficiency of the excitation light E can be improved, and fluorescence Y with the desired amount of light can be obtained.

[0120] In the light source device 100 of this embodiment, the first wall surface 54a has: a first portion 54a1, which is located on the side relatively away from the reflecting surface 54s and extends in a direction perpendicular to the reflecting surface 54s; and a second portion 54a2, which is located on the side relatively close to the reflecting surface 54s and extends obliquely relative to the reflecting surface 54s. The second wall surface 54b has: a third portion 54b3, which is located on the side relatively away from the reflecting surface 54s and extends in a direction perpendicular to the reflecting surface 54s; and a fourth portion 54b4, which is located on the side relatively close to the reflecting surface 54s and extends obliquely relative to the reflecting surface 54s. The first portion 54a1, the second portion 54a2, the third portion 54b3, and the fourth portion 54b4 reflect at least a portion of the excitation light E.

[0121] According to this structure, such as Figure 5 As shown, a portion of the excitation light E2 emitted from the light-emitting surface 56a of the light-emitting element 56 travels through the gap between the fifth surface 50e and the first portion 54a1 of the wavelength conversion member 50, and then enters the second portion 54a2, which is inclined relative to the reflecting surface 54s. At this time, the excitation light E2 is reflected by the second portion 54a2 and enters the fifth surface 50e of the wavelength conversion member 50. In this way, the excitation light E2 passing through the gap between the fifth surface 50e and the first wall surface 54a of the wavelength conversion member 50 can easily enter the fifth surface 50e, thus reducing the amount of excitation light E reflected by the reflecting surface 54s and returning to the light source section 51. Furthermore, the excitation light E1 emitted from the -Z side end of the light-emitting surface 56a and traveling towards the first wall surface 54a through the corner of the +Z side of the third surface 50c of the wavelength conversion member 50 is reflected by the first portion 54a1 extending perpendicularly relative to the reflecting surface 54s and incident on the fifth surface 50e of the wavelength conversion member 50. This reduces the amount of excitation light reflected back to the light source by the inclined first wall surface. Consequently, a light source device 100 with high utilization efficiency of the excitation light E and readily obtainable fluorescence Y with the desired light intensity can be achieved.

[0122] Furthermore, the scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention. Additionally, one aspect of the present invention can be a structure that appropriately combines the characteristic portions of the above-described embodiments.

[0123] In the second embodiment, each wall surface of the groove of the support member has a portion perpendicular to the reflective surface and a portion inclined to the reflective surface, but the shape of the groove is not particularly limited; for example, the entire area of ​​the wall surface of the groove may be perpendicular to the reflective surface. Additionally, the wall surface of the groove may be curved.

[0124] In addition, wavelength conversion components are not necessarily limited to converting light from the blue band to the yellow band; they can also convert light from other bands.

[0125] Furthermore, the specific descriptions regarding the shape, quantity, arrangement, and materials of the various structural elements of the light source device and projector are not limited to the above embodiments and can be appropriately modified. In addition, the above embodiments show an example of mounting the light source device of the present invention on a projector using a liquid crystal panel, but this is not a limitation. The light source device of the present invention can also be applied to a projector using a digital micromirror device as a light modulation device. Furthermore, the projector may not have multiple light modulation devices, and may have only one light modulation device.

[0126] The above embodiments illustrate an example of applying the light source device of the present invention to a projector, but are not limited thereto. The light source device of the present invention can also be applied to lighting fixtures, automotive headlights, etc.

[0127] The light source device of one aspect of the present invention may also have the following structure.

[0128] One aspect of the present invention provides a light source device comprising: a light-emitting element that emits first light having a first wavelength band; a wavelength conversion component comprising a phosphor that converts the first light emitted from the light-emitting element into second light having a second wavelength band different from the first wavelength band; and a reflective component that reflects the first light incident on the wavelength conversion component, the wavelength conversion component having a first surface and a second surface opposite to each other in a first direction, and a third surface and a fourth surface opposite to each other in a second direction intersecting the first direction, the second light emitting from the first surface, the first light emitted from the light-emitting element incident on the wavelength conversion component from the third surface, the reflective component being disposed opposite to the fourth surface, and the phosphor containing an activator at a concentration required to absorb less than 98% of the incident light amount of the first light in the path from the third surface to the fourth surface.

[0129] In one aspect of the light source device of the present invention, the concentration of the activator contained in the phosphor may be such that it absorbs more than 30% of the incident light amount of the first light in the path from the third surface to the fourth surface.

[0130] In one embodiment of the light source device of the present invention, the reflectivity of the reflective component may be 75% or higher.

[0131] In one embodiment of the light source device of the present invention, the reflectivity of the reflective component may be 90% or higher.

[0132] In one aspect of the light source device of the present invention, the concentration of the activator may be a concentration required to absorb less than 92% and more than 40% of the incident light amount of the first light in the path.

[0133] In one embodiment of the light source device of the present invention, the reflecting component may be composed of a support component that supports the wavelength conversion component, the support component having a reflecting surface that abuts against the fourth surface and reflects the first light incident from the third surface.

[0134] In one embodiment of the light source device of the present invention, the wavelength conversion component may further have a fifth surface and a sixth surface located on opposite sides of each other in a third direction intersecting the first direction and the second direction, and the support component may further have a groove for receiving the wavelength conversion component, the groove having: the reflective surface; a first wall surface facing and separated from the fifth surface; and a second wall surface facing and separated from the sixth surface.

[0135] In one embodiment of the light source device of the present invention, the first wall surface may have a first portion located on the side of the third surface and a second portion located on the side of the reflective surface. The first portion extends in a direction perpendicular to the reflective surface, and the second portion is inclined such that it approaches the fifth surface from the side of the first portion toward the side of the reflective surface. The second wall surface may have a third portion located on the side of the third surface and a fourth portion located on the side of the reflective surface. The third portion extends in a direction perpendicular to the reflective surface, and the fourth portion is inclined such that it approaches the sixth surface from the side of the third portion toward the side of the reflective surface. The first portion, the second portion, the third portion, and the fourth portion reflect at least a portion of the light.

[0136] The projector of one embodiment of the present invention may also have the following structure.

[0137] A projector according to one aspect of the present invention comprises: a light source device according to one aspect of the present invention; a light modulation device that modulates light including the second light emitted from the light source device according to image information; and a projection optics device that projects the light modulated by the light modulation device.

Claims

1. A light source apparatus, wherein, The light source device has the following features: A light-emitting element that emits first light with a first wavelength; A wavelength conversion component, comprising a phosphor, converts the first light emitted from the light-emitting element into second light having a second wavelength band different from the first band; and A reflective component that reflects the first light incident on the wavelength conversion component. The wavelength conversion component has a first surface and a second surface located opposite to each other in a first direction, and a third surface and a fourth surface located opposite to each other in a second direction intersecting the first direction. The second light is emitted from the first surface. The first light emitted from the light-emitting element enters the wavelength conversion component from the third surface. The reflective component is disposed opposite to the fourth surface and reflects the first light that is not absorbed when it reaches the fourth surface. The concentration of the activator contained in the phosphor is the concentration required to absorb less than 98% and more than 30% of the incident light amount of the first light in the path from the third surface to the fourth surface.

2. The light source device according to claim 1, wherein, The reflective component has a reflectivity of 75% or higher.

3. The light source device according to claim 2, wherein, The reflective component has a reflectivity of over 90%.

4. The light source device according to claim 1 or 2, wherein, The concentration of the activator is the concentration required to absorb less than 92% and more than 40% of the incident light amount of the first light in the path.

5. The light source device according to claim 1 or 2, wherein, The reflective component is composed of a support component that supports the wavelength conversion component. The supporting member has a reflective surface that abuts against the fourth surface and reflects the first light incident from the third surface.

6. The light source device according to claim 5, wherein, The wavelength conversion component also has a fifth and a sixth surface located on opposite sides of each other in a third direction that intersects the first and second directions. The support component also has a groove for receiving the wavelength conversion component. The groove has: the reflective surface; a first wall surface that faces and is separate from the fifth surface; and a second wall surface that faces and is separate from the sixth surface.

7. The light source device according to claim 6, wherein, The first wall surface has a first portion located on the side of the third surface and a second portion located on the side of the reflective surface. The first portion extends in a direction perpendicular to the reflective surface, and the second portion is inclined as it approaches the fifth surface from the side of the first portion toward the side of the reflective surface. The second wall surface has a third portion located on the side of the third surface and a fourth portion located on the side of the reflective surface. The third portion extends in a direction perpendicular to the reflective surface, and the fourth portion is inclined as it approaches the sixth surface from the side of the third portion toward the side of the reflective surface. The first part, the second part, the third part, and the fourth part reflect at least a portion of the light.

8. A projector, wherein, This projector has the following features: The light source device according to any one of claims 1 to 7; An optical modulation device that modulates light, including the second light emitted from the light source device, according to image information; as well as A projection optical device that projects light modulated by the light modulation device.

Images