JP2018054900A - Wavelength conversion element, light source device and projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a wavelength conversion element which curbs a variation in thermal resistance between a wavelength conversion layer and a peripheral member (base material) to achieve high wavelength conversion efficiency; a light source device mounted with the wavelength conversion element; and a projector mounted with the light source device.SOLUTION: A wavelength conversion element comprises: a wavelength conversion layer having a polygonal shape in planar view; and a peripheral member which has a plurality of base materials arranged on a periphery of the wavelength conversion layer in a manner that eliminates overlap with an incident direction of excitation light of the wavelength conversion layer. First side faces of respective base materials are brought into contact with second side faces of the wavelength conversion layer around the incident direction of the excitation light. Lengths of sides along the first side faces are longer than the same along the second side faces.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a wavelength conversion element, a light source device, and a projector.

  As a light source device used for a projector or the like, a light source device that irradiates a fluorescent material with excitation light emitted from a light source such as a semiconductor laser and uses fluorescent light obtained from the fluorescent material has been proposed.

  For example, Patent Document 1 discloses a light source device including a laser light source, a ceramic phosphor, and a heat sink. The ceramic phosphor includes a light emitting part and a reflecting part. The reflection part is provided so as to surround the light emitting part, and reflects light from the light emitting part. The reflection portion is provided on the outer peripheral portion of the ceramic phosphor and has a light shielding property. Specifically, the reflection portion is a portion of the ceramic phosphor that does not include the phosphor. The shape of the reflecting portion in plan view is an annular shape in which the outer periphery is a rectangular side and the inner periphery is an arc.

Japanese Patent Laid-Open No. 2006-058624

  Since the liquid crystal panel as the light modulation device has a rectangular shape, the outer shape of the light emitting unit is preferably rectangular. When the base material provided around the light emitting part has a rectangular hole, and a rectangular wavelength converting element layer is provided as a light emitting part in the hole of the base material, the wavelength converting element layer and the hole Due to the dimensional tolerance, the gap between each side surface of the wavelength conversion element layer and the side surface of the hole facing each side surface varies. Even if the gap is filled for the purpose of heat dissipation of the wavelength conversion element layer, the thermal resistance between the wavelength conversion element layer and the substrate depends on the size of the gap between the wavelength conversion element layer and the hole. Therefore, the temperature of the wavelength conversion element layer becomes non-uniform, and there is a problem that the conversion efficiency of the wavelength conversion element layer varies.

  One aspect of the present invention is made in view of the above-described problems of the prior art, and suppresses variations in thermal resistance between the wavelength conversion layer and the base material (outer peripheral member), so that the wavelength conversion element layer can be obtained. An object of the present invention is to provide a wavelength conversion element that is excellent in wavelength conversion efficiency by suppressing variations in conversion efficiency. One aspect of the present invention is to provide a light source device including the above-described wavelength conversion element. One aspect of the present invention is to provide a projector including the light source device described above.

  The wavelength conversion element according to an aspect of the present invention includes a polygonal wavelength conversion layer in plan view and a plurality of base materials provided around the wavelength conversion layer without overlapping with the incident direction of the excitation light of the wavelength conversion layer. An outer peripheral member, and each of the plurality of base materials is disposed so that a first side surface of the plurality of base materials is in contact with a second side surface around the incident direction of the wavelength conversion layer. The side along the side is longer than the side along the second side surface.

  In the wavelength conversion element according to one embodiment of the present invention, the wavelength conversion layer having a rectangular shape in plan view and the wavelength conversion layer provided around the wavelength conversion layer without overlapping the incident direction of the excitation light of the wavelength conversion layer, the wavelength conversion An outer peripheral member having a plurality of base materials forming the same layer as the layer, and at least one side of each of the plurality of base materials is longer than each side around the incident direction, and each of the plurality of base materials The first side surface along the one side may be disposed so as to abut on the second side surface around the optical axis of the wavelength conversion layer.

  According to this, in each base material of the outer peripheral member provided around the wavelength conversion layer, each first side surface is disposed in contact with the second side surface of the wavelength conversion layer. Compared with the case where a hole is formed in the outer peripheral member (base material) and the wavelength conversion element layer is provided in the hole, each substrate is attached to the wavelength conversion layer regardless of the dimensional tolerance of the wavelength conversion element. It can be arranged without a gap. As a result, variation in the thermal resistance between the wavelength conversion layer and the substrate depending on the size of the gap is suppressed, and unevenness in the temperature of the wavelength conversion layer at the same excitation light amount is suppressed, thereby reducing the wavelength conversion layer. Variations in conversion efficiency can be suppressed.

  The wavelength conversion element in 1 aspect of this invention WHEREIN: The structure which the edge part of the said 1st side surface of each of these base materials corresponds to the edge part of the said 2nd side surface of the said wavelength conversion layer which opposes It is good.

  According to this, positioning of a some base material with respect to a wavelength conversion layer is attained.

  The wavelength conversion element in 1 aspect of this invention WHEREIN: As a structure by which the reflection layer is provided between each said 1st side surface of the said several base material, and the said 2nd side surface of the said wavelength conversion layer. Also good.

  According to this, the fluorescent light generated in the wavelength conversion layer can be efficiently emitted in a desired direction.

  In the wavelength conversion element according to an aspect of the present invention, the reflective layer is formed on the first side surface of the base material, and the wavelength conversion layer and the base material include the second side surface and the reflective layer. It is good also as a structure joined by the permeable joining material provided between these.

  In this configuration, the fluorescent light generated in the wavelength conversion layer is transmitted through the transmissive bonding material used for bonding the wavelength conversion layer and the substrate, and is reflected by the reflection layer. Therefore, when a reflective layer is provided on the substrate side, a light-transmitting bonding material is used. Compared with the case where a reflection layer is formed on one surface (first side surface) of each substrate, a hole is formed in the outer peripheral member (substrate) and a reflection layer is formed on the inner wall of the hole. Easy to manufacture.

  In the wavelength conversion element according to an aspect of the present invention, the reflection layer is formed on the second side surface of the wavelength conversion layer, and the wavelength conversion layer and the substrate include the reflection layer and the first side surface. It is good also as a structure joined by the joining material provided between these.

  In this configuration, the fluorescent light generated in the wavelength conversion layer is reflected by the reflection layer provided on the second side surface. An impermeable bonding material can be used for bonding the reflective layer of the wavelength conversion layer and the base material, and various bonding materials can be used as the bonding material. In addition, since a bonding material having high thermal conductivity can be used as the bonding material, heat generated in the wavelength conversion layer can be efficiently conducted to the outer peripheral member, and heat dissipation of the wavelength conversion layer is improved.

  In the wavelength conversion element according to one embodiment of the present invention, the plurality of base materials may have the same shape.

  According to this, the cost of each substrate can be reduced, and since all the substrates have the same shape, the manufacture of the wavelength conversion element is facilitated.

  The wavelength conversion element in 1 aspect of this invention WHEREIN: It is good also as a structure provided with the board | substrate on the opposite side to the light-incidence end surface of the said wavelength conversion layer.

  According to this, in the reflection type wavelength conversion element, the heat of the wavelength conversion layer can be conducted also to the substrate side, and the nonuniformity of the temperature of the wavelength conversion layer in the same excitation light amount is suppressed, and the wavelength conversion is performed. Variation in the conversion efficiency of the layers can be suppressed.

  The wavelength conversion element in 1 aspect of this invention WHEREIN: It is good also as a structure provided with the translucent member which is provided in the incident side of the excitation light of the said wavelength conversion layer, and has the inclination part inclined with respect to the said incident side.

  According to this, the component which can be taken out in a desired direction among fluorescent lights generated in the wavelength conversion layer increases.

  A light source device according to an aspect of the present invention includes an excitation light source that emits excitation light and the wavelength conversion element on which the excitation light is incident.

  According to this, the light source device excellent in wavelength conversion efficiency can be provided by providing the wavelength conversion element of one aspect of the present invention.

  A projector according to an aspect of the present invention includes the above light source device, a light modulation device that generates image light by modulating light emitted from the light source device according to image information, and projection optics that projects the image light. A system.

  According to this, it becomes a projector provided with the light source device excellent in wavelength conversion efficiency, and becomes highly reliable.

1 is a schematic configuration diagram illustrating a projector according to a first embodiment. The schematic block diagram which shows the light source device of 1st Embodiment. Sectional drawing which shows schematic structure of the wavelength conversion element in 1st Embodiment. The perspective view which shows the structure of the wavelength conversion element in 1st Embodiment. The exploded view for demonstrating the structure of the wavelength conversion element in 1st Embodiment. The exploded view for demonstrating the structure of the wavelength conversion element in 1st Embodiment. The exploded view for demonstrating the structure of the wavelength conversion element in 1st Embodiment. It is sectional drawing which shows the structure of the modification of the wavelength conversion element in 1st Embodiment. The figure which shows schematic structure of the light source device in 2nd Embodiment. Sectional drawing which cut | disconnected the wavelength conversion element in 2nd Embodiment by the plane containing the illumination optical axis of FIG. The disassembled perspective view for demonstrating the structure of a wavelength conversion element. The top view of the wavelength conversion element seen from the incident side of excitation light.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In addition, in the drawings used in the following description, in order to make the features easy to understand, there are cases where the portions that become the features are enlarged for the sake of convenience, and the dimensional ratios of the respective components are not always the same as the actual ones. Absent.

[First Embodiment]
(projector)
The projector according to the present embodiment is an example of a projector using three transmissive liquid crystal light valves.
FIG. 1 is a schematic configuration diagram illustrating a projector according to the present embodiment.

  As shown in FIG. 1, the projector 1 includes a light source device 2A, a color separation optical system 3, a light modulation device 4R, a light modulation device 4G, a light modulation device 4B, a light combining optical system 5, and a projection optical system 6. It is equipped with. The light source device 2A emits illumination light WL. The color separation optical system 3 separates the illumination light WL from the light source device 2A into red light LR, green light LG, and blue light LB. Each of the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B modulates the red light LR, the green light LG, and the blue light LB in accordance with image information to form image light of each color. The light combining optical system 5 combines the image light of each color from each light modulation device 4R, 4G, 4B. The projection optical system 6 projects the combined image light from the light combining optical system 5 toward the screen SCR.

  The light source device 2A includes a part of the blue excitation light emitted from the semiconductor laser, the blue excitation light emitted without wavelength conversion, and the yellow fluorescent light generated by the wavelength conversion of the excitation light by the phosphor. , And the white illumination light (white light) WL synthesized. The light source device 2 </ b> A emits the illumination light WL adjusted so as to have a substantially uniform illuminance distribution toward the color separation optical system 3. A specific configuration of the light source device 2A will be described later.

  The color separation optical system 3 includes a first dichroic mirror 7a, a second dichroic mirror 7b, a first reflection mirror 8a, a second reflection mirror 8b, a third reflection mirror 8c, and a first A relay lens 9a and a second relay lens 9b are provided.

  The first dichroic mirror 7a separates the illumination light WL emitted from the light source device 2A into red light LR and light in which green light LG and blue light LB are mixed. Therefore, the first dichroic mirror 7a has characteristics of transmitting the red light LR and reflecting the green light LG and the blue light LB. The second dichroic mirror 7b separates the light in which the green light LG and the blue light LB are mixed into the green light LG and the blue light LB. Therefore, the second dichroic mirror 7b has a characteristic of reflecting the green light LG and transmitting the blue light LB.

  The first reflection mirror 8a is disposed in the optical path of the red light LR, and reflects the red light LR that has passed through the first dichroic mirror 7a toward the light modulation device 4R. The second reflection mirror 8b and the third reflection mirror 8c are disposed in the optical path of the blue light LB, and guide the blue light LB transmitted through the second dichroic mirror 7b to the light modulation device 4B. The second dichroic mirror 7b reflects the green light LG toward the light modulation device 4G.

  The first relay lens 9a and the second relay lens 9b are arranged at the subsequent stage of the second dichroic mirror 7b in the optical path of the blue light LB. The first relay lens 9a and the second relay lens 9b compensate for the optical loss of the blue light LB due to the optical path length of the blue light LB being longer than the optical path lengths of the red light LR and the green light LG.

  Each of the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B includes a liquid crystal panel. Each of the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B allows the red light LR, the green light LG, and the blue light to pass through each of the red light LR, the green light LG, and the blue light LB. Each LB is modulated in accordance with image information to form image light corresponding to each color. Polarizing plates (not shown) are respectively arranged on the light incident side and the light emission side of the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B.

  On the light incident side of each of the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B, red light LR and green light incident on each of the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B. A field lens 10R, a field lens 10G, and a field lens 10B that collimate the LG and the blue light LB are provided.

  The light combining optical system 5 is composed of a cross dichroic prism. The light combining optical system 5 combines the image light of each color from each of the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B, and emits the combined image light toward the projection optical system 6.

  The projection optical system 6 is composed of a projection lens group. The projection optical system 6 enlarges and projects the image light combined by the light combining optical system 5 toward the screen SCR. Thereby, an enlarged color video (image) is displayed on the screen SCR.

(Light source device)
Next, the light source device 2A will be described.
FIG. 2 is a diagram illustrating a schematic configuration of the light source device.
FIG. 3 is a cross-sectional view illustrating a schematic configuration of the wavelength conversion element.

As illustrated in FIG. 2, the light source device 2 </ b> A includes a first lighting device 100 and a second lighting device 102.
The first lighting device 100 includes a first light source 10, a collimating optical system 70, a dichroic mirror 80, a collimating condensing optical system 90, a wavelength conversion element 51, a first lens array 120, and a second lens array 130. And a polarization conversion element 140 and a superimposing lens 150.

The first light source 10 is composed of a semiconductor laser that emits blue laser light (emission intensity peak: about 445 nm) B in the first wavelength band as excitation light. The first light source 10 may be composed of one semiconductor laser or may be composed of a plurality of semiconductor lasers.
The first light source 10 may be a semiconductor laser that emits blue laser light having a wavelength other than 445 nm, for example, 460 nm.

The first light source 10 is arranged so that the optical axis 200ax of the laser light emitted from the first light source 10 is orthogonal to the illumination optical axis 100ax.
The collimating optical system 70 includes a first lens 72 and a second lens 74. The collimating optical system 70 makes the light emitted from the first light source 10 substantially parallel. The 1st lens 72 and the 2nd lens 74 are comprised by the convex lens.

  The dichroic mirror 80 is disposed in the optical path from the collimating optical system 70 to the collimating condensing optical system 90 so as to intersect with each of the optical axis 200ax of the first light source 10 and the illumination optical axis 100ax at an angle of 45 °. Has been. The dichroic mirror 80 reflects the excitation light B and transmits yellow fluorescent light Y including red light and green light.

The collimator condensing optical system 90 has a function of condensing the excitation light B that has passed through the dichroic mirror 80 and making it incident on the wavelength conversion element 51 and a function of making the fluorescence emitted from the wavelength conversion element 51 substantially parallel. Have. The collimator condensing optical system 90 includes a first lens 92 and a second lens 94. The 1st lens 92 and the 2nd lens 94 are comprised by the convex lens.
The second illumination device 102 includes a second light source 710, a condensing optical system 760, a scattering plate 732, and a collimating optical system 770.

The second light source 710 is composed of the same semiconductor laser as the first light source 10 of the first lighting device 100. The second light source 710 may be composed of one semiconductor laser or may be composed of a plurality of semiconductor lasers.
The condensing optical system 760 includes a first lens 762 and a second lens 764. The condensing optical system 760 condenses the blue excitation light B emitted from the second light source 710 on the scattering plate 732 or in the vicinity of the scattering plate 732. The 1st lens 762 and the 2nd lens 764 are comprised by the convex lens.

  The scattering plate 732 scatters the blue light B from the second light source 710 and generates blue light B having a light distribution close to the light distribution of the fluorescent light Y emitted from the wavelength conversion element 51. As the scattering plate 732, for example, polished glass made of optical glass can be used.

  The collimating optical system 770 includes a first lens 772 and a second lens 774. The collimating optical system 770 substantially parallelizes the light emitted from the scattering plate 732. The first lens 772 and the second lens 774 are composed of convex lenses.

  The blue light B emitted from the second illumination device 102 is reflected by the dichroic mirror 80 and is combined with the fluorescent light Y emitted from the wavelength conversion element 51 and transmitted through the dichroic mirror 80 to become white light WL. The white light WL is incident on the first lens array 120.

  The first lens array 120 includes a plurality of first lenses 122 for dividing the white light WL into a plurality of partial light beams. The plurality of first lenses 122 are arranged in a matrix in a plane orthogonal to the illumination optical axis 100ax.

  The second lens array 130 has a plurality of second lenses 132 corresponding to the plurality of first lenses 122 of the first lens array 120. The second lens array 130 forms an image of each first lens 122 of the first lens array 120 together with the superimposing lens 150 in the vicinity of the image forming regions of the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B. Let The plurality of second lenses 132 are arranged in a matrix in a plane orthogonal to the illumination optical axis 100ax.

  The polarization conversion element 140 converts the light emitted from the second lens array 130 into linearly polarized light. The polarization conversion element 140 includes, for example, a polarization separation film and a phase difference plate (both not shown).

  The superimposing lens 150 condenses the partial light beams emitted from the polarization conversion element 140 and superimposes them in the vicinity of the image forming regions of the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B shown in FIG. Let

  As described above, the light source device 2 </ b> A emits the illumination light WL adjusted to have a substantially uniform illuminance distribution toward the color separation optical system 3.

  As shown in FIG. 3, the wavelength conversion element 51 includes a wavelength conversion layer 42, an outer peripheral member 48 including a plurality of base materials 40, a base substrate (substrate) 43, a reflective layer 44, and a transmissive bonding material 45. . The wavelength conversion element 51 emits the fluorescent light Y toward the same side as the side on which the excitation light B made of blue light is incident. That is, the wavelength conversion element 51 is a reflective wavelength conversion element.

  For example, the wavelength conversion layer 42 has a rectangular planar shape and includes an inorganic phosphor material. The wavelength conversion layer 42 is disposed substantially at the center of the one surface 43 a of the base substrate 43. The wavelength conversion layer 42 includes a lower surface 42e positioned substantially on the same plane as the lower surface 48e of the outer peripheral member 48, and a light incident / exit surface 42a positioned approximately on the same plane as the upper surface 48a of the outer peripheral member 48. The wavelength conversion layer 42 includes phosphor particles (not shown) that convert the excitation light B into arbitrary fluorescent light. The wavelength conversion layer 42 converts the blue excitation light B incident from the light incident / exit surface 42a into yellow fluorescent light Y and emits it from the light incident / exit surface 42a. The thickness of the wavelength conversion layer 42 is set to about 0.1 mm to 2 mm. The planar shape of the wavelength conversion layer 42 may be a polygonal shape.

  As the phosphor particles, for example, YAG (yttrium, aluminum, garnet) phosphors are used. In addition, the material for forming the phosphor particles may be one kind, or a mixture of particles formed using two or more kinds of materials may be used. For the wavelength conversion layer 42, it is preferable to use a layer excellent in heat resistance and surface processability. As such a wavelength conversion layer 42, a phosphor layer in which phosphor particles are dispersed in an inorganic binder such as alumina, a phosphor layer in which phosphor particles are sintered without using a binder, and the like are preferably used.

  Each of the plurality of base materials 40 is, for example, a plate body having a rectangular planar shape, and is disposed so as to surround the periphery of the wavelength conversion layer 42 disposed on the one surface 43 a of the base substrate 43. The plurality of base materials 40 are arranged on one surface 43 a of the base substrate 43, so that the upper surface 40 d as the surface on the light incident / exit surface 42 a side of the plurality of base materials 40 constitutes the upper surface 48 a of the outer peripheral member 48. The base material 40 has a thickness substantially equal to that of the wavelength conversion layer 42, and for example, the thickness is set to about 0.1 mm to 2 mm. As a material of the base material 40, it is preferable to use a material having high thermal conductivity and excellent heat dissipation, and examples thereof include metals such as aluminum and copper, and ceramics such as aluminum nitride, alumina, sapphire, and diamond. Or you may be comprised with materials, such as glass and quartz.

  The base substrate 43 is provided on the side opposite to the light incident / exit surface 42 a of the wavelength conversion layer 42. The lower surface 42 e of the wavelength conversion layer 42 is provided so as to contact the one surface 43 a of the base substrate 43. The base substrate 43 is made of a material excellent in heat dissipation, and is made of a metal substrate excellent in heat dissipation such as aluminum and copper. On one surface 43 a of the base substrate 43, the wavelength conversion layer 42 and the plurality of base materials 40 are arranged to form the same layer. The lower surface 48e of the outer peripheral member 48 is provided so as to abut one surface 43a of the base substrate 43.

  The reflective layer 44 is disposed between the second side surface 42 b of the wavelength conversion layer 42 and the first side surface 40 b of the substrate 40. The reflective layer 44 is designed to reflect the fluorescent light Y with a high reflectance. Specific examples of the reflective layer 44 include a metal reflective film having a high reflectance such as aluminum and silver. Thereby, the reflective layer 44 reflects most of the fluorescent light Y toward the base material 40 toward the upper side in FIG. 3 (the side opposite to the base substrate 43).

  The transmissive bonding material 45 is disposed between the surface facing the second side surface 42 b of the reflective layer 44 and the second side surface 42 b of the wavelength conversion layer 42, and has four base materials with respect to the wavelength conversion layer 42. 40 is joined. The transmissive bonding material 45 is appropriately selected depending on the material of the wavelength conversion layer 42 and the reflection layer 44. The fluorescent light from the wavelength conversion layer 42 passes through the transmissive bonding material 45 and is reflected by the reflection layer 44.

Next, the configuration of the wavelength conversion element will be described in detail.
FIG. 4 is a perspective view showing the configuration of the wavelength conversion element in the first embodiment.
FIG. 5 is an exploded view for explaining the configuration of the wavelength conversion element in the first embodiment.
FIG. 6 is an exploded view for explaining the configuration of the wavelength conversion element in the first embodiment.
FIG. 7 is an exploded view for explaining the configuration of the wavelength conversion element in the first embodiment.

  As shown in FIG. 4, the number of base materials 40 matches the number of second side surfaces 42 b of the wavelength conversion layer 42. In the present embodiment, since the wavelength conversion layer 42 has a rectangular shape in plan view, four base materials 40 are disposed around the wavelength conversion layer 42. The four base materials 40 are provided on the same plane without overlapping in the incident direction of the excitation light B incident on the light incident / exit surface 42 a of the wavelength conversion layer 42.

  As described above, the base material 40 having a rectangular shape in plan view has a size larger than the planar shape of the wavelength conversion layer 42, and at least one side of the base material 40 (the long side constituting the first side surface 40b). 40c) is longer than each side 42c (FIG. 5) around the incident direction of the excitation light B incident on the light incident / exit surface 42a of the wavelength conversion layer 42. That is, in the substrate 40, one side (long side 40 c) in the outer peripheral direction with respect to the incident direction of the excitation light B incident on the light incident / exit surface 42 a of the wavelength conversion layer 42 is longer than each side 42 c of the wavelength conversion layer 42. In the base material 40, the long side 40c is a side that forms an end of the upper surface 40d. In the present embodiment, all four sides of the substrate 40 have a length longer than each side 42 c of the wavelength conversion layer 42.

  As shown in FIG. 4, in the wavelength conversion layer 42, the first side surfaces 40 b of the four base materials 40 arranged in the periphery abut each of the second side surfaces 42 b of the wavelength conversion layer 42. Arranged in a state. Specifically, the four base materials 40 are in contact with the second side surfaces 42b of the wavelength conversion layer 42 via the reflective layers 44 (FIG. 3) provided on the first side surfaces 40b. The second side surface 42b is joined by the permeable joining material 45. Here, the wavelength conversion layer 42 (second side surface 42 b) and the four base materials 40 (first side surface 40 b) are bonded together with no gap between each other via the transmissive bonding material 45. Preferably it is. In the present embodiment, the reflective layer 44 of each substrate 40 and the wavelength conversion layer 42 are in thermal contact with each other by the transparent bonding material 45 that also has heat conductivity (does not interfere with heat dissipation of the wavelength conversion layer 42). Yes.

  In addition, as shown in FIG. 5, the first side surfaces 40 b along the long side 40 c of one adjacent base material 40 are opposed surfaces 40 a along the short side of the other adjacent base material 40. The outer peripheral member 48 that is bonded to each other while being in contact with each other and surrounds the outer periphery of the wavelength conversion layer 42 is formed.

  As shown in FIG. 6, the wavelength conversion layer 42 is positioned inside a positioning hole 47 having a rectangular shape in plan view, which is configured by abutting the four base materials 40 with each other. The shape of the positioning hole 47 is a rectangle reflecting the shape of the wavelength conversion layer 42 when viewed from the normal direction of the base substrate 43.

  The side surface 40Aa of the one adjacent base material 40 and the side surface 40Ab of the other adjacent base material 40 substantially coincide with each other in the circumferential direction and form the same surface. The outer peripheral surface 48A of the outer peripheral member 48 includes side surfaces 40Aa and side surfaces 40Ab of the base materials 40 that are alternately present in the circumferential direction.

  Note that the side surface 40Aa of one base 40 adjacent to each other has the same shape as the facing surface 40a, and the side 40Ab of the other base 40 adjacent to each other has the same shape as the first side 40b. The side surface 40Aa and the facing surface 40a face each other in one adjacent base material 40, and the side surface 40Ab and the first side surface 40b face each other in the other adjacent base material 40.

  As shown in FIG. 6, the outer peripheral member 48 of the present embodiment has an outer shape substantially equal to that of the base substrate 43, so that the outer peripheral surface 48 </ b> A is flush with the outer peripheral surface 43 </ b> A of the base substrate 43. The size and shape of the outer peripheral member 48 and the base substrate 43 in plan view are not limited to the configuration of the present embodiment, and can be changed as appropriate.

  As shown in FIG. 7, in the present embodiment, each end q of the first side surface 40 b of the four base materials 40 substantially coincides with each end s of the second side surface 42 b of the wavelength conversion layer 42. Yes. At the time of manufacture, positioning of each base material 40 with respect to the wavelength conversion layer 42 becomes possible by aligning the end q on the base material 40 side and the end s on the wavelength conversion layer 42 side.

  The edge part q of the base material 40 is formed in the corner | angular part formed of the 1st side surface 40b and the opposing surface 40a.

The assembly of the outer peripheral member 48 with respect to the wavelength conversion layer 42 can be exemplified as follows.
Of the four substrates 40, any one substrate 40 is selected, and the first side surface 40b of the substrate 40 is brought into contact with the second side surface 42b of the wavelength conversion layer 42. The end portion q of the base material 40 adjacent to the base material 40 is brought into contact with the corner portion formed by the contact, that is, the end portion s of the wavelength conversion layer 42, and the adjacent base material 40. The first side surface 40b is brought into contact with the second side surface 42b of the wavelength conversion layer 42 facing the first side surface 40b. The corner portion formed by bringing the adjacent base material 40 into contact, that is, the end portion s of the wavelength conversion layer 42 is contacted with the end portion q of the base material 40 further adjacent to the adjacent base material 40. Make contact. By sequentially repeating these procedures, the outer peripheral member 48 is assembled to the wavelength conversion layer 42.

  In the conventional wavelength conversion element, since the wavelength conversion layer is disposed in the hole formed in the center of the outer peripheral member made of a single plate, the wavelength conversion layer is caused by the dimensional tolerance between the wavelength conversion layer and the hole. In each side face, the gaps between the holes were uneven. There is a problem in that the conversion efficiency of the wavelength conversion element varies due to variations in thermal resistance between the wavelength conversion layer and the substrate.

  On the other hand, in this embodiment, the outer peripheral member 48 is divided into a plurality of parts and is constituted by four base materials 40. As described above, in the configuration of the present embodiment, the four base materials 40 are arranged around the wavelength conversion layer 42, and the first side surface 40 b of each base material 40 corresponds to each second of the wavelength conversion layer 42. Due to the configuration in contact with the side surface 42 b, no extra gap is generated between the wavelength conversion layer 42 and the substrate 40. By making the outer peripheral member 48 into a divided configuration, each base material 40 can be bonded to the wavelength conversion layer 42 without any gap, regardless of the dimensional tolerance of the wavelength conversion layer 42. Therefore, the dimensional error of the gap between the wavelength conversion layer 42 (each second side surface 42b) and the outer peripheral member 48 (first side surface 40b of each substrate 40) can be reduced as compared with the conventional configuration.

  Thereby, the dispersion | variation in the thermal resistance of the wavelength conversion layer 42 and the base material 40 depending on the magnitude | size of a clearance gap is suppressed, and the temperature of the wavelength conversion layer 42 with the same excitation light quantity is stabilized. That is, by surrounding the wavelength conversion layer 42 with a plurality of base materials 40 without gaps, the heat generated in the wavelength conversion layer 42 is transferred to the outer peripheral member 48 (via the reflective layer 44 or the transmissive bonding material 45). Each base material 40) can be efficiently conducted. As a result, the heat radiation of the wavelength conversion layer 42 is evenly performed, variation in the conversion efficiency of the wavelength conversion element 51 can be reduced, and a highly reliable projector can be provided.

  In the present embodiment, at least one side (long side 40 c) of the base material 40 has a length longer than each side 42 c of the wavelength conversion layer 42, and the base material 40 is flatter than the wavelength conversion layer 42. Large shape. Therefore, the contact area between the base material 40 and the base substrate 43 can be increased, and the thermal resistance therebetween can be reduced.

  Furthermore, in this embodiment, not only between the wavelength conversion layer 42 and each base material 40, but also between the wavelength conversion element 51 and the base substrate 43, and between each of the plurality of base materials 40, there is no gap. It is preferable that it is assembled in a state. Thereby, since light leaking from between the wavelength conversion layer 42 and each base material 40 can be eliminated, light can be efficiently extracted from the wavelength conversion element 51.

  Although it is possible to adopt a configuration in which the reflective layer 44 is not provided, the reflective layer 44 is provided by providing the reflective layer 44 between the wavelength conversion layer 42 and each substrate 40 as in the present embodiment. Compared with the case where it is not provided, the fluorescent light emitted from the wavelength conversion layer 42 can be efficiently extracted from the light incident / exit surface 42a.

  In the present embodiment, the reflective layer 44 is provided on the first side surface 40 b of the base material 40. Since the reflective layer 44 only needs to be formed on one surface (first side surface 40b) of the substrate 40, the reflective layer 44 is formed on the four surfaces (four second side surfaces 42b) around the wavelength conversion layer 42. Manufacture is easier than filming. Moreover, manufacture is easy compared with the case where a hole part is formed in an outer peripheral member (base material), and a reflection layer is formed in the inner wall of the said hole part.

On the other hand, as shown in FIG. 8, when the reflective layer 44 is provided on the four second side surfaces 42 b of the wavelength conversion layer 42, each base material 40 and the reflective layer 44 are interposed via the impermeable bonding material 46. The wavelength conversion layer 42 having In such a configuration, the fluorescent light from the wavelength conversion layer 42 is directly incident on the reflection layer 44 and reflected. As the impermeable bonding material 46, various bonding materials can be used as the bonding material. Further, since a bonding material having high thermal conductivity can be used as the bonding material, the heat generated in the wavelength conversion layer 42 can be efficiently conducted to the outer peripheral member 48, and the heat dissipation of the wavelength conversion layer 42 is improved. It is done.
As a result, the temperature of the wavelength conversion layer 42 decreases, and the wavelength conversion efficiency of the wavelength conversion layer 42 can be increased.

  A reflective layer may also be provided between the wavelength conversion layer 42 and the outer peripheral member 48 and the base substrate 43. At this time, the reflective layer may be provided on the wavelength conversion element 51 side or may be provided on the base substrate 43 side. With this configuration, the light extraction efficiency in the wavelength conversion element 51 is further increased.

  Moreover, in this embodiment, since the some base material 40 which comprises the outer peripheral member 48 is the same shape, component cost can be reduced. In view of ease of manufacturing, the shape of each base material 40 is preferably the same shape, but is not necessarily limited thereto. As long as at least one side (side facing the wavelength conversion layer 42) of the substrate 40 has a length longer than each side of the wavelength conversion layer 42, other shapes may be used.

  In addition, in this embodiment, the base material 40 which makes a planar view rectangular shape was used, However, The planar view shape of the base material 40 is not restricted to this. For example, as shown in FIG. 7, on the end q side of the base material 40, the angle θ between the first side surface 40 b and the adjacent facing surface 40 a via the end q is 90 ° or less. That's fine. Moreover, the shape of the some base material 40 which comprises the outer peripheral member 48 is not restricted to the same structure, A mutually different shape may be sufficient.

  In addition, when each base material 40 of the outer periphery member 48 is comprised with materials, such as aluminum, since the surface of each base material 40 has light reflectivity, the reflection layer 44 does not necessarily need to be provided. Good.

[Example 1]
When the reflective layer 44 is provided on the wavelength conversion layer 42 side, between the reflective layer 44 provided on the second side surface 42b of the wavelength conversion layer 42 and the base material 40, between the adjacent base materials 40. In the meantime, the reflective layer 44 provided on the lower surface 42e of the wavelength conversion layer 42 and the lower surface 48e of the outer peripheral member 48 and the base substrate 43 are fixed with a silicone-based adhesive mixed with a filler having high thermal conductivity.

[Example 2]
When the reflective layer 44 is provided on the first side surface 40b of each base material 40 or one surface 43a of the base substrate 43, the wavelength conversion with the reflective layer 44 provided on the first side surface 40b of the base material 40 is performed. A transparent silicone-based adhesive is fixed between the layer 42, between the adjacent base materials 40, and between the one surface 43 a of the base substrate 43 and the lower surface 42 e of the wavelength conversion layer 42 and the lower surface 48 e of the outer peripheral member 48. .

  By configuring so that the gap between the members constituting the wavelength conversion element 51 is substantially eliminated, heat generated in the wavelength conversion element 51 can be conducted to the outer peripheral member 48 and the base substrate 43 with a small temperature difference. Thereby, the temperature rise of the wavelength conversion element 51 can be suppressed and the wavelength conversion efficiency can be increased.

[Second Embodiment]
Next, a projector according to a second embodiment of the invention will be described.
The basic configuration of the projector 50 (FIG. 1) of the present embodiment described below is substantially the same as that of the first embodiment, but differs in that the wavelength conversion element 52 of the light source device 2B is a transmissive type. Therefore, in the following description, the light source device 2B will be described in detail, and description of common parts will be omitted. Moreover, in each drawing used for description, the same code | symbol shall be attached | subjected to the same component as FIGS.

(Light source device)
Next, the light source device 2B in the second embodiment will be described.
FIG. 9 is a diagram illustrating a schematic configuration of a light source device 2B according to the second embodiment.
As shown in FIG. 9, the light source device 2 </ b> B of the projector 50 (FIG. 1) in the second embodiment includes an excitation light source 110, an afocal optical system 11, a homogenizer optical system 12, and a first condensing optical system 20. A wavelength conversion element 52, a second condensing optical system 60, a first lens array 120, a second lens array 130, a polarization conversion element 140, and a superimposing lens 150.

  The excitation light source 110 includes a plurality of semiconductor lasers 110A that emit blue excitation light B made of laser light. The peak of the emission intensity of the excitation light B is, for example, 445 nm. The plurality of semiconductor lasers 110A are arranged in an array in one plane orthogonal to the illumination optical axis 100ax. As the excitation light source 110, a semiconductor laser that emits blue light having a wavelength other than 445 nm, for example, 455 nm or 460 nm can also be used.

  The afocal optical system 11 includes, for example, a convex lens 11a and a concave lens 11b. The afocal optical system 11 reduces the diameter of a light beam composed of a plurality of laser beams emitted from the excitation light source 110. A collimator optical system may be disposed between the afocal optical system 11 and the excitation light source 110 to convert the excitation light incident on the afocal optical system 11 into a parallel light beam.

  The homogenizer optical system 12 includes, for example, a first multi-lens array 12a and a second multi-lens array 12b. The homogenizer optical system 12 makes the light intensity distribution of the excitation light in a uniform state on the wavelength conversion layer, which will be described later, a so-called top hat distribution. The homogenizer optical system 12 superimposes a plurality of small light beams emitted from a plurality of lenses of the first multi-lens array 12 a on the wavelength conversion layer together with the first condensing optical system 20. Thereby, the light intensity distribution of the excitation light B irradiated on the wavelength conversion layer is made uniform.

The first condensing optical system 20 includes, for example, a first lens 20a and a second lens 20b. The first condensing optical system 20 is disposed in the optical path from the homogenizer optical system 12 to the wavelength conversion element 52, condenses the excitation light B, and enters the wavelength conversion layer of the wavelength conversion element 52.
In the present embodiment, the first lens 20a and the second lens 20b are each composed of a convex lens.

  The second condensing optical system 60 includes, for example, a first collimating lens 62 and a second collimating lens 64. The second condensing optical system 60 makes the light emitted from the wavelength conversion element 52 substantially parallel. The first collimating lens 62 and the second collimating lens 64 are each composed of a convex lens.

  The first lens array 120 has a plurality of first lenses 122 for dividing the light emitted from the second condensing optical system 60 into a plurality of partial light beams. The plurality of first lenses 122 are arranged in a matrix in a plane orthogonal to the illumination optical axis 100ax.

  The second lens array 130 has a plurality of second lenses 132 corresponding to the plurality of first lenses 122 of the first lens array 120. The second lens array 130 forms an image of each first lens 122 of the first lens array 120 together with the superimposing lens 150 in the vicinity of the image forming regions of the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B. Let The plurality of second lenses 132 are arranged in a matrix in a plane orthogonal to the illumination optical axis 100ax.

  The polarization conversion element 140 converts the light emitted from the second lens array 130 into linearly polarized light. The polarization conversion element 140 includes, for example, a polarization separation film and a phase difference plate (both not shown).

  The superimposing lens 150 condenses the partial light beams emitted from the polarization conversion element 140 and superimposes them in the vicinity of the image forming regions of the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B shown in FIG. Let

(Wavelength conversion element)
Next, the wavelength conversion element of 2nd Embodiment is demonstrated.
FIG. 10 is a cross-sectional view of the wavelength conversion element 52 according to the second embodiment cut along a plane including the illumination optical axis 100ax of FIG. FIG. 11 is an exploded perspective view for explaining the configuration of the wavelength conversion element 52. FIG. 12 is a plan view of the wavelength conversion element 52 viewed from the incident side of the excitation light B. FIG.

  As shown in FIG. 10, the wavelength conversion element 52 includes an outer peripheral member 48 composed of a plurality of base materials 40, a wavelength conversion layer 42, a translucent member 33, a dichroic film 34, a reflection layer 44, and a reflection layer. 36.

  As shown in FIGS. 10 and 11, the outer peripheral member 48 is composed of four base materials 40 as in the previous embodiment, and the first side surface 40 b of each base material 40 is the first of the wavelength conversion layer 42. 2 is bonded to the wavelength conversion layer 42 in contact with the side surface 42b. The wavelength conversion layer 42 is located inside the positioning hole 47 (FIG. 12) configured by the four base materials 40.

  As shown in FIG. 10, the translucent member 33 is provided on the light incident end surface 32 a side of the wavelength conversion layer 42, that is, on the lower surface 48 e side of the outer peripheral member 48. The translucent member 33 is composed of a plano-convex lens made of a translucent material such as glass, quartz, and sapphire. The translucent member 33 has a flat surface 33f and a convex surface (inclined portion) 33d. The flat surface 33 f of the translucent member 33 faces the light incident end surface 32 a of the wavelength conversion layer 42. A translucent heat conducting member 37 is provided between the translucent member 33 and the wavelength conversion layer 42, and the translucent member 33 and the wavelength conversion layer 42 are in thermal contact with each other.

  The translucent member 33 has a hemispherical shape, and the convex surface (inclined portion) 33d of the translucent member 33 has a hemispherical shape. The convex surface 33d has a curved surface. When the translucent member 33 is viewed from the normal direction of the flat surface 33 f, the translucent member 33 has a circular shape, and the central portion of the translucent member 33 overlaps the wavelength conversion layer 42. The translucent member 33 is arranged so that the excitation light B passes through a dichroic film 34 and a light incident end face 32a, which will be described later, and enters the wavelength conversion layer 42 in this order.

  The refractive index of the translucent member 33 is desirably substantially equal to the refractive index of the wavelength conversion layer 42. When the refractive index of the translucent member 33 is substantially equal to the refractive index of the wavelength conversion layer 42, the loss due to reflection when excitation light or fluorescent light passes through the interface between the translucent member 33 and the wavelength conversion layer 42 is minimized. To the limit. As a result, more fluorescent light can be extracted in a desired direction.

  The dichroic film 34 is provided on the convex surface 33 d of the translucent member 33. The convex surface 33 d is a support surface that includes an inclined portion that is inclined with respect to the light incident end surface 32 a and supports the dichroic film 34. The dichroic film 34 is provided along the convex surface 33 d that is a support surface of the translucent member 33, and has a hemispherical shape.

  The dichroic film 34 has a characteristic of transmitting the blue excitation light B emitted from the excitation light source 110 and reflecting the yellow fluorescent light Y generated by the wavelength conversion layer 42. The fluorescent light Y <b> 1 generated by the wavelength conversion layer 42 is reflected by a reflection layer 44 provided between each base material 40 and the wavelength conversion layer 42.

  The reflective layer 36 is provided between the outer peripheral member 48 and the translucent member 33. The reflection layer 36 reflects the component of the fluorescent light Y reflected by the dichroic film 34 and traveling toward the region outside the light incident end face 32 a toward the dichroic film 34. As with the reflective layer 44, it is desirable to use a metal material with high reflectivity such as aluminum or silver for the reflective layer.

  In addition, when each base material 40 of the outer periphery member 48 is comprised with materials, such as aluminum, since the surface of each base material 40 has light reflectivity, the reflective layer 44 and the reflective layer 36 are not necessarily provided. It does not have to be.

  As described above, the configuration in which the outer peripheral member 48 is divided into the plurality of base materials 40 and each of the base materials 40 is bonded to the wavelength conversion layer 42 is the transmission-type wavelength conversion element 52 as in this embodiment. Can also be applied. Since the four base materials 40 are disposed in contact with the second side surfaces 42b with respect to the wavelength conversion layer 42, the wavelength conversion layer 42 and the outer peripheral member 48 (each base material 40) are disposed between them. It can be in a state where there is almost no gap. Thereby, variation in thermal resistance between the wavelength conversion layer 42 and the substrate 40 is suppressed, and the temperature of the wavelength conversion layer 42 with the same excitation light amount is stabilized. Thereby, the dispersion | variation in the conversion efficiency of the wavelength conversion element 52 can be reduced.

  Moreover, since the translucent member 33 and the wavelength conversion layer 42 are in thermal contact with each other via the heat conducting member 37, the heat generated in the wavelength conversion layer 42 is not limited to the base material 40, but the translucent member. 33 can also be transmitted to dissipate heat.

  As described above, since the wavelength conversion element 52 includes the hemispherical translucent member 33 including the dichroic film 34, the fluorescent light generated by the wavelength conversion layer 42 is upward (translucent) from the light incident end surface 32a. It can be efficiently taken out toward the side opposite to the optical member 33).

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

  DESCRIPTION OF SYMBOLS 1,50 ... Projector, 2A, 2B ... Light source device, 4B, 4G, 4R ... Light modulation device, 6 ... Projection optical system, 32a ... Light incident end surface, 33 ... Translucent member, 33d ... Convex surface (inclined part), 36, 44 ... reflective layer, 40 ... base material, 40 ... base material (base material), 40b ... first side surface, 42 ... wavelength conversion layer, 42a ... light incident / exit end surface, 42b ... second side surface, 42c ... Sides, 43 ... base substrate, 45 ... permeable bonding material, 46 ... non-permeable bonding material, 48 ... outer peripheral member, 51, 52 ... wavelength conversion element, 110 ... excitation light source, B ... excitation light, q ... substrate The end of the first side surface, s... The end of the second side surface of the wavelength conversion element

Claims (10)

A wavelength conversion layer having a polygonal shape in plan view;
An outer peripheral member having a plurality of base materials provided around the wavelength conversion layer without overlapping the incident direction of the excitation light of the wavelength conversion layer,
The first side surfaces of the plurality of base materials are disposed so as to contact the second side surface around the incident direction of the wavelength conversion layer,
The wavelength conversion element, wherein the side along the first side surface is longer than the side along the second side surface.   2. The wavelength conversion element according to claim 1, wherein an end portion of the first side surface of each of the plurality of base materials coincides with an end portion of the second side surface of the wavelength conversion layer facing each other. A reflective layer is provided between the first side surface of each of the plurality of base materials and the second side surface of the wavelength conversion layer.
The wavelength conversion element according to claim 1. The reflective layer is formed on the first side surface of the substrate;
The wavelength conversion layer and the base material are bonded by a transmissive bonding material provided between the second side surface and the reflective layer.
The wavelength conversion element according to claim 3. The reflective layer is formed on the second side surface of the wavelength conversion layer,
The wavelength conversion layer and the base material are bonded by a bonding material provided between the reflective layer and the first side surface.
The wavelength conversion element according to claim 3. The plurality of substrates each have the same shape.
The wavelength conversion element as described in any one of Claim 1 thru | or 5. A substrate is provided on the side opposite to the light incident end face of the wavelength conversion layer,
The wavelength conversion element as described in any one of Claim 1 thru | or 6. Provided with an excitation light incident side of the wavelength conversion layer, and a translucent member having an inclined portion inclined with respect to the incident side;
The wavelength conversion element as described in any one of Claim 1 thru | or 6. An excitation light source that emits excitation light;
The wavelength conversion element according to any one of claims 1 to 8, wherein the excitation light is incident;
A light source device. The light source device according to claim 9;
A light modulation device for generating image light by modulating light emitted from the light source device according to image information;
A projection optical system that projects the image light.

Images