JP2018036457A - Wavelength conversion element, light source device, and projector - Google Patents

Abstract

Provided is a wavelength conversion element in which phosphor layer suppresses efficient light emission and deterioration due to temperature rise. A wavelength conversion element includes a base material 41, a phosphor layer 42 containing a first phosphor 42P that emits light when incident excitation light enters, and a second phosphor 43P (thermally conductive material). And an adhesive layer 43 that adheres the base material 41 and the phosphor layer 42. [Selection] Figure 3

Description

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

  Conventionally, a projector that modulates light emitted from a light source device according to image information and projects an image on a projection surface such as a screen is known. In recent years, a technique using a phosphor for the light source device for the projector has been proposed (for example, see Patent Document 1).

  The light source device described in Patent Document 1 includes a laser light source and a phosphor device. The phosphor device includes a phosphor layer that is an inorganic binder phosphor and a heat radiator. The phosphor layer has a reflective layer formed directly on the phosphor, and is bonded and fixed to the heat radiating body with an organic adhesive, an inorganic adhesive, low-melting glass or the like. In the phosphor device, the phosphor emits fluorescence by the excitation light from the laser light source, the fluorescence is reflected by the reflection layer, and is emitted to the side on which the excitation light is incident.

JP 2013-210439 A

  However, in the technique described in Patent Document 1, since an adhesive having a low thermal conductivity is interposed between the phosphor layer and the heat radiating body, the heat of the phosphor layer due to absorption of excitation light is efficiently radiated. It is considered difficult to dissipate heat through the body. If the heat generation of the phosphor layer becomes significant, a phenomenon (temperature quenching) in which the light emission efficiency decreases as the temperature of the phosphor increases, and it is difficult to emit high-intensity light. There exists a subject that long-term reliability falls by deterioration of a body layer or an adhesive agent.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  [Application Example 1] A wavelength conversion element according to this application example includes a base material, a phosphor layer containing a first phosphor that emits light when incident excitation light is incident thereon, and a heat conductive material. An adhesive layer that adheres a base material and the phosphor layer is provided.

  According to this configuration, since the heat-conductive material is contained in the adhesive layer that bonds the base material and the phosphor layer, the heat of the phosphor layer that generates heat when irradiated with the excitation light is efficiently obtained. It can be transmitted to the base material to dissipate heat. Therefore, the temperature rise of the phosphor layer and thus the wavelength conversion element is suppressed. Therefore, it is possible to provide a wavelength conversion element that can efficiently emit light by suppressing temperature quenching and suppress deterioration due to temperature rise.

  Application Example 2 In the wavelength conversion element according to the application example described above, it is preferable that the thermally conductive material includes a second phosphor that emits light when incident excitation light having passed through the phosphor layer is incident.

  According to this configuration, the thermally conductive material contained in the adhesive layer has the second phosphor. Accordingly, the wavelength conversion element can efficiently dissipate the phosphor layer and increase the amount of light emission.

  Application Example 3 In the wavelength conversion element according to the application example, it is preferable that the first phosphor and the second phosphor emit light in a first wavelength band.

  According to this configuration, since the second phosphor emits light in the same wavelength band as the wavelength band emitted by the first phosphor, the thickness of the phosphor layer can be reduced without reducing the amount of light emission compared to the configuration of the prior art. Can be formed thinly. Therefore, the heat dissipation of the phosphor layer can be further improved.

  Application Example 4 In the wavelength conversion element according to the application example described above, the first phosphor emits light in a first wavelength band, and the second phosphor is a second different from the first wavelength band. It is preferable to emit light having a wavelength band of.

  According to this configuration, the wavelength that contributes to the brightness of the light emitted from the first fluorescent material is supplemented with the light emitted from the second fluorescent material, or the light emitted from the first fluorescent material. The second phosphor can emit the band light. As a result, it is possible to provide a wavelength conversion element that emits light with good hue or light with higher luminance.

  Application Example 5 A light source device according to this application example includes a light emitting unit that emits excitation light and the wavelength conversion element described above in which the excitation light is incident.

  According to this configuration, since the light source device includes the wavelength conversion element described above, it is possible to emit high-luminance light by effectively using the excitation light emitted from the light emitting unit. Moreover, since the light source device includes a wavelength conversion element in which deterioration due to a temperature rise is suppressed, the lifetime can be extended.

  Application Example 6 A projector according to this application example projects the light source device described above, a light modulation device that modulates light emitted from the light source device, and light that is modulated by the light modulation device. And an optical device.

  According to this configuration, since the projector includes the light source device described above, a bright image can be projected over a long period of time.

1 is a schematic diagram showing an optical system of a projector according to a first embodiment. The top view of the wavelength conversion element of a 1st embodiment. The fragmentary sectional view of the wavelength conversion element of a 1st embodiment. The graph which shows the thickness of the two layers formed on the base material in the wavelength conversion element used for simulation. The graph which shows a simulation result. FIG. 6 is a schematic diagram illustrating an optical system of a projector according to a second embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The projector according to the present embodiment modulates light emitted from a light source according to image information and projects an image on a projection surface such as a screen. In the drawings shown below, the dimensions and ratios of the components are appropriately changed from the actual ones in order to make the components large enough to be recognized on the drawings.

(First embodiment)
FIG. 1 is a schematic diagram showing an optical system of a projector 1 according to this embodiment.
As shown in FIG. 1, the projector 1 includes an illumination device 100, a color separation light guide optical system 200, light modulation devices 400R, 400G, and 400B, a cross dichroic prism 500, and a projection optical device 600.

The illumination device 100 includes a first light source device 101, a second light source device 102, a dichroic mirror 103, a first lens array 120, a second lens array 130, a polarization conversion element 140, and a superimposing lens 150.
The first light source device 101 includes a first light emitting unit 10, a collimating optical system 70, a collimating condensing optical system 90, and a wavelength conversion device 30.

  The first light emitting unit 10 includes a semiconductor laser and emits blue light E (emission intensity peak: about 445 nm) as excitation light. The first light emitting unit 10 may be composed of one semiconductor laser or may be composed of a plurality of semiconductor lasers. Note that the first light emitting unit 10 may be a semiconductor laser that emits blue light having a wavelength other than 445 nm (for example, 460 nm).

The collimating optical system 70 includes a first lens 72 and a second lens 74, and makes the light emitted from the first light emitting unit 10 substantially parallel.
The dichroic mirror 103 has a function of reflecting the blue light E and passing the yellow light Y including red light and green light. The dichroic mirror 103 is disposed at an angle of 45 ° with respect to the optical axis of the first light emitting unit 10, and reflects the blue light E emitted from the first light emitting unit 10 and passing through the collimating optical system 70. To do.

  The collimator condensing optical system 90 includes a first lens 92 and a second lens 94. The collimator condensing optical system 90 has a function of condensing the blue light E reflected by the dichroic mirror 103 onto a wavelength conversion element 40 (to be described later) of the wavelength conversion device 30 and makes the light emitted from the wavelength conversion element 40 substantially parallel. It has a function.

The wavelength conversion device 30 includes a wavelength conversion element 40 and a motor 35.
FIG. 2 is a plan view of the wavelength conversion element 40.
As shown in FIGS. 1 and 2, the wavelength conversion element 40 includes a base material 41, a phosphor layer 42, and an adhesive layer 43.
The base material 41 is formed in a disk shape from a metal member having excellent heat dissipation, such as aluminum or copper, and is configured to be rotatable by a motor 35. The base material 41 is provided with a reflecting portion (reflecting film 41R) on the collimator condensing optical system 90 side. In addition, the base material 41 is not limited to metal, and for example, an inorganic material such as ceramic can be used.

The phosphor layer 42 contains the first phosphor 42P (see FIG. 3), and is formed in a ring shape on the base 41 on the collimator condensing optical system 90 side.
The adhesive layer 43 contains the second phosphor 43P (see FIG. 3) as a heat conductive material, and is disposed between the reflective film 41R and the phosphor layer 42, and the base material 41 and the phosphor layer 42 are connected. Glue.

The first phosphor 42P and the second phosphor 43P of the present embodiment are made of, for example, (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce, which is a YAG phosphor. The first phosphor 42P is excited by the blue light E (excitation light) collected by the collimator condensing optical system 90, and emits light in the first wavelength band (yellow light Y including red light and green light). . The second phosphor 43P is excited by the excitation light that has passed through the phosphor layer 42, and emits light in the first wavelength band. The phosphor layer 42 and the adhesive layer 43 will be described in detail later.
The wavelength conversion element 40 reflects the excited yellow light Y to the collimator condensing optical system 90 side by the reflection film 41R.

  As shown in FIG. 1, the second light source device 102 is disposed on the opposite side of the dichroic mirror 103 from the collimating optical system 70. The second light source device 102 includes a second light emitting unit 710, a condensing optical system 760, a scattering plate 732, and a collimating optical system 770.

The second light emitting unit 710 includes the same semiconductor laser as that of the first light emitting unit 10 and emits blue light B.
The condensing optical system 760 includes a first lens 762 and a second lens 764, and substantially condenses the blue light B emitted from the second light emitting unit 710 on the scattering plate 732.

  The scattering plate 732 scatters the incident blue light B so as to have a light distribution similar to the light distribution of the yellow light Y emitted from the wavelength conversion element 40. 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 and makes the light from the scattering plate 732 substantially parallel.
The light collimated by the collimating optical system 770 is reflected by the dichroic mirror 103 to the side opposite to the collimating condensing optical system 90.

  The yellow light Y emitted from the first light source device 101 passes through the dichroic mirror 103, is synthesized from the blue light B emitted from the second light source device 102 and reflected by the dichroic mirror 103, and is combined as the white light W. One lens array 120 is emitted.

  The first lens array 120, the second lens array 130, and the superimposing lens 150 constitute an integrator optical system. Specifically, the first lens array 120 includes a plurality of first small lenses 122 for dividing the light from the dichroic mirror 103 into a plurality of partial light beams. The plurality of first small lenses 122 are arranged in a matrix in a plane that intersects the optical axis 100ax of the illumination device 100.

The second lens array 130 has a plurality of second small lenses 132 corresponding to the plurality of first small lenses 122 of the first lens array 120. The second lens array 130 forms an image of each first small lens 122 of the first lens array 120 together with the superimposing lens 150 on the image forming regions of the light modulation devices 400R, 400G, and 400B.
The polarization conversion element 140 aligns random light emitted from the second lens array 130 with approximately one type of polarized light that can be used in the light modulation devices 400R, 400G, and 400B.

  The color separation light guide optical system 200 includes dichroic mirrors 210 and 220, reflection mirrors 230, 240 and 250, and relay lenses 260 and 270. The color separation light guide optical system 200 separates the white light W emitted from the illumination device 100 into red light R, green light G, and blue light B, and separates into red light R, green light G, and blue light B, respectively. The light is guided to the corresponding light modulators 400R, 400G, 400B. In addition, field lenses 300R, 300G, and 300B are disposed between the color separation light guide optical system 200 and the light modulation devices 400R, 400G, and 400B.

  Although not shown in detail, each of the light modulation devices 400R, 400G, and 400B includes a liquid crystal panel, and an incident-side polarizing plate and an emitting-side polarizing plate arranged on the light incident side and the light emitting side of the liquid crystal panel, respectively. Yes. Then, the light modulation devices 400R, 400G, and 400B modulate incident color light according to image information to form an image corresponding to each color light.

  The cross dichroic prism 500 has a substantially square shape in plan view in which four right-angle prisms are bonded together, and a dielectric multilayer film is formed on a substantially X-shaped interface in which the right-angle prisms are bonded together. The cross dichroic prism 500 combines the image light of each color light emitted from each of the light modulation devices 400R, 400G, 400B.

  The projection optical apparatus 600 includes a plurality of lenses (not shown), and enlarges and projects the image light combined by the cross dichroic prism 500 as a color image on a projection surface SCR such as a screen.

[Configuration of wavelength conversion element]
Here, the wavelength conversion element 40 will be described in detail.
FIG. 3 is a partial cross-sectional view of the wavelength conversion element 40.
As described above, in the wavelength conversion element 40, the phosphor layer 42 is provided on the reflective film 41 </ b> R of the base material 41 via the adhesive layer 43.

The phosphor layer 42 is a member having high thermal conductivity and translucency, and the first phosphor 42P is made into a bulk, polycrystal, or single crystal, or the particles of the first phosphor 42P are made of an inorganic binder. Solid materials such as alumina and low-melting glass are used.
In the adhesive layer 43, a second phosphor 43P having an average particle diameter of about 10 μm to 20 μm is bound with a silicon-based adhesive having translucency. Further, the content of the second phosphor 43P is about 30 vol%.

  The phosphor layer 42 is laminated on the adhesive layer 43 after the vacuum degassed adhesive layer 43 is applied on the reflective film 41R by screen printing. The phosphor layer 42 is fixed to the base material 41 by curing the adhesive layer 43 in a high temperature environment. The adhesive used for the adhesive layer 43 is not limited to silicon as long as it has high heat resistance (for example, heat resistance of 150 ° C. or higher) and translucency. For example, acrylic or epoxy It may be a system or the like, and may be an organic system or an inorganic system.

  In the wavelength conversion element 40, since the heat conductive material (second phosphor 43P) is contained in the adhesive layer 43, the heat of the phosphor layer 42 that generates heat by absorbing the excitation light is efficiently used as the base material 41. To be told. Moreover, since the wavelength conversion element 40 contains the second phosphor 43P in the adhesive layer 43, the thickness of the phosphor layer 42 can be reduced without reducing the amount of light emission. As a result, the heat dissipation of the wavelength conversion element 40 is improved.

  Here, it demonstrates using the simulation result compared with the wavelength conversion element 900 (not shown) of the prior art that the heat dissipation of the wavelength conversion element 40 is favorable. In addition, as the wavelength conversion element 900 of the prior art used for the simulation, the base material is the same as the base material 41 of the wavelength conversion element 40 and has the phosphor layer 920 made of the same material as the phosphor layer 42. The phosphor layer 920 is fixed with a silicon-based adhesive (adhesive layer 930).

  FIG. 4 is a graph showing the thicknesses of two layers formed on the base material 41 in the wavelength conversion element 900 and the wavelength conversion element 40 used in the simulation. Specifically, FIG. 4 shows the thickness of two layers (phosphor layer 920 and adhesive layer 930) of the wavelength conversion element 900, and the thickness of two layers (phosphor layer 42 and adhesive layer 43) of the wavelength conversion element 40. 3 is a graph showing the total thickness of two layers of each of the wavelength conversion elements 900 and 40. For the wavelength conversion element 40, four types (wavelength conversion elements 40A, 40B, 40C, and 40D) in which the thicknesses of the phosphor layer 42 and the adhesive layer 43 are changed are shown.

  The thicknesses of the phosphor layer 42 and the adhesive layer 43 of each of the wavelength conversion elements 40A, 40B, 40C, and 40D are the light absorption rate of excitation light in the phosphor layer 42 and the adhesive layer 43, and the phosphor layer of the wavelength conversion element 900. The light absorption rate of the excitation light at 920 is set to be the same. That is, the wavelength conversion elements 40A, 40B, 40C, 40D and the wavelength conversion element 900 are set so that the light emission amounts are equal.

The thickness of the phosphor layer 42 can be made thinner than the thickness of the phosphor layer 920 as shown in FIG. 4 because the adhesive layer 43 contains the second phosphor 43P. Specifically, the thickness of the phosphor layer 42 can be about 0.06 mm to 0.15 mm while the thickness of the phosphor layer 920 is about 0.2 mm.
The wavelength conversion elements 40A, 40B, 40C, and 40D absorb light of excitation light when the thickness of the phosphor layer 42 is set so as to decrease in the order of the wavelength conversion elements 40A, 40B, 40C, and 40D. The thickness of the adhesive layer 43 is set so that the rate is the same. Therefore, as shown in FIG. 4, the thickness of the adhesive layer 43 is set so as to increase in the order of the wavelength conversion elements 40A, 40B, 40C, and 40D.

FIG. 5 is a graph showing the simulation results of the thermal resistance of the two layers of the wavelength conversion element 900 and the wavelength conversion elements 40A, 40B, 40C, and 40D, and the surface temperatures of the phosphor layers 920 and 42. The sum of the thermal resistances of the two layers is referred to as “total thermal resistance”.
The simulation was performed under the following conditions. In terms of thermal conductivity, the phosphor layers 42, 920: 9 W / m · k, the adhesive layer 43: 0.5 W / m · k, and the adhesive layer 930: 0.2 W / m · k. In the base material 41, aluminum having a plate thickness of 1 mm and an outer diameter of 100 mm was used. The planar size of the phosphor layers 42 and 920 is set in a ring shape having an outer diameter of 65 mm and an inner diameter of 55 mm. And excitation light shall be irradiated by the size of 2.6 mm x 2.6 mm on the fluorescent substance layers 42 and 920 at 200W.

  As shown in FIG. 5, in the wavelength conversion element 900, the thermal resistance of the adhesive layer 930 occupies most of the total thermal resistance, and the total thermal resistance of the wavelength conversion element 900 is the wavelength conversion elements 40A, 40B, 40C, and 40D. Greater than the total heat resistance. Specifically, the total thermal resistance of the wavelength conversion element 900 is about 0.13 ° C./W, and the total thermal resistance of the wavelength conversion elements 40A, 40B, 40C, and 40D is about 0.04 to 0.07 ° C./W. W. Further, the total thermal resistance of the wavelength conversion elements 40A, 40B, 40C, and 40D increases in the order of the wavelength conversion elements 40A, 40B, 40C, and 40D because the thickness of the adhesive layer 43 greatly contributes.

Corresponding to the thermal resistance, the surface temperatures of the wavelength conversion elements 40A, 40B, 40C, and 40D were lower than the surface temperature of the wavelength conversion element 900. In addition, among the wavelength conversion elements 40A, 40B, 40C, and 40D, the surface temperature of the wavelength conversion element 40A was the lowest. Specifically, the surface temperature of the wavelength conversion element 900 is about 173 ° C, the surface temperature of the wavelength conversion element 40A is about 160 ° C, and the wavelength conversion element 40A is about 13 ° C lower than the wavelength conversion element 900. Obtained.
Thus, the wavelength conversion element 40 had a total heat resistance smaller than the total heat resistance of the wavelength conversion element 900, and good heat dissipation was obtained.

  In the simulation described above, the thickness of the phosphor layer 42 is set to be thinner than the phosphor layer 920 so that the light absorption rate of the excitation light is the same between the wavelength conversion element 40 and the wavelength conversion element 900. Although shown, the wavelength conversion element 40 can also be configured such that the thickness of the phosphor layer 42 is equal to the thickness of the phosphor layer 920 of the wavelength conversion element 900. In the case of this configuration, the thermal resistance of the phosphor layer 42 is smaller than the thermal resistance of the adhesive layer 43. Therefore, even if the thickness of the phosphor layer 42 is increased, the heat dissipation is not deteriorated so much and the light emission amount is increased. It becomes possible.

As described above, according to the configuration of the present embodiment, the following effects can be obtained.
(1) Since the adhesive layer 43 that bonds the base material 41 and the phosphor layer 42 contains a heat conductive material (second phosphor 43P), fluorescence that generates heat when irradiated with excitation light. It becomes possible to efficiently transfer the heat of the body layer 42 to the base material 41 and dissipate it. Therefore, the temperature rise of the phosphor layer 42 and thus the wavelength conversion element 40 is suppressed. Therefore, it is possible to provide the wavelength conversion element 40 that can efficiently emit light by suppressing the temperature quenching and suppress deterioration due to a temperature rise.

  (2) Since the adhesive layer 43 contains the second phosphor 43P, the amount of light emission can be increased.

  (3) The second phosphor 43P emits light (yellow light Y) in the same first wavelength band as the first wavelength band emitted by the first phosphor 42P. It is possible to reduce the thickness of the phosphor layer 42 without reducing it. Therefore, the heat dissipation of the phosphor layer 42 can be further improved.

  (4) Since the first light source device 101 includes the wavelength conversion element 40, high-luminance light (yellow light Y) is emitted by effectively using the excitation light emitted from the first light emitting unit 10. It becomes possible to do. In addition, the first light source device 101 includes the wavelength conversion element 40 in which deterioration due to a temperature rise is suppressed, so that the lifetime can be extended.

  (5) Since the projector 1 includes the first light source device 101, a bright image can be projected over a long period of time.

(Second Embodiment)
Hereinafter, the projector 11 according to the second embodiment will be described with reference to the drawings. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted or simplified.
FIG. 6 is a schematic diagram showing an optical system of the projector 11 according to the present embodiment.
The projector 11 of this embodiment includes a lighting device 104 that is different from the lighting device 100 included in the projector 1 of the first embodiment.

  The illuminating device 104 has a configuration in which the illuminating device 100 according to the first embodiment includes two light source devices (first light source device 101 and second light source device 102), as shown in FIG. 105. Moreover, the illuminating device 104 is provided with the 1st lens array 120, the 2nd lens array 130, the polarization conversion element 140, and the superimposition lens 150 similarly to the illuminating device 100 of 1st Embodiment.

The light source device 105 includes a light emitting unit 13, a condensing optical system 75, a wavelength conversion device 60, and a collimating optical system 95.
The light emitting unit 13 is composed of a semiconductor laser similar to the first light emitting unit 10 of the illumination device 100 and emits blue light B.
The condensing optical system 75 includes a first lens 76 and a second lens 77, and condenses the blue light B emitted from the light emitting unit 13 on the phosphor layer 63 of the wavelength conversion device 60.

The wavelength conversion device 60 includes a wavelength conversion element 61 and a motor 35 that rotates the wavelength conversion element 61.
The wavelength conversion element 61 includes a base material 62 formed in a disc shape, a ring-shaped phosphor layer 63 provided on the surface of the base material 62 opposite to the condensing optical system 75, and the base material 62 and the fluorescent light. An adhesive layer 64 that adheres to the body layer 63 is provided.

The base material 62 is formed of a member through which the blue light B emitted from the light emitting unit 13 is transmitted, for example, quartz glass, crystal, sapphire, or the like.
The phosphor layer 63 is formed in the same manner as the phosphor layer 42 of the first embodiment, and contains a first phosphor (not shown).
The adhesive layer 64 is configured in the same manner as the adhesive layer 43 of the first embodiment, and contains a second phosphor (not shown) as a thermally conductive material.

  The blue light B emitted from the light emitting unit 13 passes through the base material 62 and enters the adhesive layer 64. Part of the blue light B incident on the adhesive layer 64 excites the second phosphor, and the remaining part enters the phosphor layer 63. The second phosphor excited by the blue light B emits yellow light Y. A part of the blue light B incident on the phosphor layer 63 excites the first phosphor, and the remaining part transmits the phosphor layer 63. The first phosphor excited by the blue light B emits yellow light Y. The light emitted from the phosphor layer 63 forms white light W obtained by combining the blue light B and the yellow light Y.

The collimating optical system 95 includes a first lens 96 and a second lens 97, and makes the white light W emitted from the wavelength conversion element 61 substantially parallel.
White light W emitted from the collimating optical system 95 enters the first lens array 120. The optical system after the first lens array 120 is configured similarly to the optical system of the first embodiment.

As described above, according to the configuration of the present embodiment, the following effects can be obtained.
(1) Since the heat conductive material (second phosphor) is contained in the adhesive layer 64 that bonds the base material 62 and the phosphor layer 63, excitation light (blue light B) is irradiated. As a result, the heat of the phosphor layer 63 that generates heat can be efficiently transmitted to the base material 62 to be dissipated. Therefore, it is possible to provide the wavelength conversion element 61 that can efficiently emit light by suppressing temperature quenching and suppress deterioration due to temperature rise.

  (2) Since the base material 62 is formed of a member that transmits the excitation light, the wavelength conversion element 61 fluoresces the light excited by the excitation light incident from the opposite side of the phosphor layer 63 of the base material 62. The body layer 63 can be injected on the side opposite to the base material 62.

Note that the present invention is not limited to the above-described embodiment, and various modifications and improvements can be added to the above-described embodiment. A modification will be described below.
(Modification 1)
In the embodiment, the second phosphor 43P is used as the heat conductive material contained in the adhesive layers 43 and 64. However, the material has high heat conductivity and translucency (for example, diamond, alumina, As long as it is sapphire, oxide ceramics, or the like, a material that does not emit light may be configured as a thermally conductive material. Moreover, the structure which these materials and the 2nd fluorescent substance 43P coexist may be sufficient.

(Modification 2)
In the embodiment, the first wavelength band light emitted from the first phosphor 42P and the second phosphor 43P is configured to be the yellow light Y, but the light in the first wavelength band is the yellow light Y. Light in a wavelength band other than that may be used.

(Modification 3)
In the embodiment, the second phosphor 43P is configured to emit light (yellow light) in the same first wavelength band as the first phosphor 42P. However, the second phosphor 43P is configured to emit light in the first wavelength band. You may comprise so that the light of the 2nd wavelength band different from may be emitted. For example, the configuration in which the second phosphor 43P emits light in the second wavelength band containing a lot of green light and the configuration in which the second phosphor 43P emits light in the second wavelength band containing a lot of red light are exemplified. can do.

Since the green light is light in a wavelength band that particularly contributes to luminance, when the second phosphor 43P is configured to emit light in the second wavelength band containing a large amount of green light, the wavelength conversion element 40 is yellow with higher luminance. Light can be emitted.
The light emitted from the YAG-based phosphor is weaker in red light than green light. Therefore, when the second phosphor 43P is configured to emit light in the second wavelength band containing a lot of red light, the wavelength conversion element 40 is It is possible to emit yellow light that balances the intensity of green light and red light.
Further, when two types of phosphors having different compositions (first phosphor 42P and second phosphor 43P) are used, it is difficult to manufacture them in one phosphor layer. Since the body layers 42 and 63 and the adhesive layers 43 and 64 are contained separately, the wavelength conversion elements 40 and 61 can be easily manufactured.

(Modification 4)
The first phosphor 42P and the second phosphor 43P of the embodiment are configured to be excited by excitation light in the same wavelength band, but the first phosphor 42P and the second phosphor 43P have different wavelengths. You may comprise so that it may be excited with the excitation light of a belt | band | zone. For example, the light source device emits excitation light having a blue light wavelength band and an ultraviolet light wavelength band, and one of the first phosphor 42P and the second phosphor 43P is excited by blue light to emit light, and the other is ultraviolet. A configuration that emits light when excited by light is possible.

(Modification 5)
Although the base material 41 of the said embodiment is formed in disk shape, it may be not only a disk shape but polygonal shape, for example. Moreover, although the base materials 41 and 62 are configured to rotate in the embodiment, a configuration that does not rotate may be used.

(Modification 6)
In the projector according to the embodiment, a transmissive liquid crystal panel is used as a light modulation device, but a reflective liquid crystal panel may be used. Further, a micromirror type light modulation device such as a DMD (Digital Micromirror Device) may be used as the light modulation device.

(Modification 7)
The light modulation device according to the above embodiment employs a so-called three-plate method using three light modulation devices 400R, 400G, and 400B corresponding to R light, G light, and B light. A plate method may be adopted, or the present invention can be applied to a projector including two or four or more light modulation devices.

  DESCRIPTION OF SYMBOLS 1,11 ... Projector, 10 ... 1st light emission part, 40, 61 ... Wavelength conversion element, 41, 62 ... Base material, 42, 63 ... Phosphor layer, 42P ... 1st phosphor, 43 ... Adhesion layer, 43P DESCRIPTION OF SYMBOLS ... 2nd fluorescent substance, 101 ... 1st light source device, 105 ... Light source device, 400R, 400G, 400B ... Light modulation device, 600 ... Projection optical apparatus.

Claims (6)

A substrate;
A phosphor layer containing a first phosphor that emits light when excitation light is incident thereon;
An adhesive layer containing a thermally conductive material and bonding the substrate and the phosphor layer;
A wavelength conversion element comprising: The wavelength conversion element according to claim 1,
The wavelength conversion element, wherein the thermally conductive material includes a second phosphor that emits light when excitation light having passed through the phosphor layer is incident. The wavelength conversion element according to claim 2,
The wavelength conversion element, wherein the first phosphor and the second phosphor emit light in a first wavelength band. The wavelength conversion element according to claim 2,
The first phosphor emits light in a first wavelength band, and the second phosphor emits light in a second wavelength band different from the first wavelength band. . A light emitting unit for emitting excitation light;
The wavelength conversion element according to any one of claims 1 to 4, wherein the excitation light is incident;
A light source device comprising: A light source device according to claim 5;
A light modulation device that modulates light emitted from the light source device;
A projection optical device for projecting light modulated by the light modulation device;
A projector comprising:

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