JP2016061853A - Light source device and projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source device capable of efficiently utilizing fluorescent light while preventing expansion of spot diameter, and a projector.SOLUTION: The light source device includes: a light emitting element that emits a beam of excitation light; a fluorescent substance layer 42 that emits fluorescent light being irradiated with the excitation light; and a scattering layer 31 including plural particles, which is formed at the side opposite to a plane from which the excitation light from the fluorescent substance layer 42 enters.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a light source device and a projector.

  In recent years, a projector using a phosphor is used as a light source device of a projector. Conventionally, a general phosphor layer is formed by hardening a phosphor with a resin. However, since fluorescence is generated by irradiating the phosphor layer with laser light, the temperature of the phosphor layer and the resin rises due to the laser light, causing temperature quenching of the phosphor, and deterioration of the resin due to heat. Then there was a problem of degeneration.

  Therefore, an invention is known in which a phosphor layer in which an inorganic material such as glass or ceramics and a phosphor are solidified is used to improve the heat dissipation of the phosphor and to suppress the temperature rise of the phosphor (for example, patents) Reference 1).

JP 2012-190555 A

  However, the above prior art has a problem in that the difference between the refractive index of the inorganic material such as glass and ceramics and the refractive index of the phosphor is small, so that it is difficult for the fluorescence to scatter during propagation in the phosphor layer. . If it is not scattered during propagation through the phosphor layer, the fluorescence will easily propagate through the phosphor layer. In this case, since the fluorescence travels a long distance in the phosphor layer in a direction parallel to the light emission surface of the phosphor layer, the spot diameter of the fluorescence emitted from the phosphor layer increases, and the etendue may increase. There is. Therefore, for example, when the light source device is applied to a projector, there is a problem in that the use efficiency of the projection light is reduced.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a light source device and a projector that can suppress the increase in spot diameter and can efficiently use fluorescence.

  According to the first aspect of the present invention, a light emitting element that emits excitation light, a phosphor layer that emits fluorescence when the excitation light is incident, and a surface of the phosphor layer on which the excitation light is incident are: There is provided a light source device including a scattering layer provided on the opposite side and including a plurality of particles.

  According to the light source device according to the first aspect, the fluorescent light incident on the scattering layer from the phosphor layer is scattered and the traveling direction is greatly changed, so that the fluorescent light has a long distance in a direction parallel to the light emission surface of the phosphor layer. Before proceeding, it is ejected from the light exit surface. Therefore, the spot diameter of the fluorescence emitted from the phosphor layer can be reduced.

The first aspect may further include a metal substrate provided on the opposite side of the scattering layer from the phosphor layer, and a reflective portion provided between the scattering layer and the metal substrate. Good.
According to this configuration, the heat generation of the phosphor layer can be efficiently exhausted through the metal substrate. Therefore, it is possible to suppress an excessive increase in temperature of the phosphor layer and suppress a decrease in fluorescence emission efficiency due to a temperature increase.
Moreover, since the reflection part reflects the fluorescent light traveling toward the metal substrate and emits it from the light exit surface, a high-intensity light source device is provided.

In the first aspect, the scattering layer may join the metal substrate and the phosphor layer.
According to this configuration, since the scattering layer is also used as the adhesive layer, the number of parts can be reduced.

In the first aspect, provided on the opposite side of the phosphor layer from the scattering layer, provided between the transparent substrate that transmits the excitation light, the phosphor layer and the transparent substrate, and the excitation light. It is good also as a structure further equipped with the reflecting film which permeate | transmits and reflects the said fluorescence.
According to this configuration, a configuration is realized in which excitation light enters from one side of the phosphor layer and fluorescence is emitted from the other side of the phosphor layer. This eliminates the need for an optical member for separating excitation light and fluorescence, thereby reducing the increase in the number of parts and the restrictions on the part layout. Therefore, a small light source device can be provided.

In the first aspect, the phosphor layer may be composed of a composite material of an inorganic material and a phosphor.
According to this configuration, it becomes possible to exhaust heat of the phosphor more efficiently, and light with higher luminance can be obtained.

  According to the second aspect of the present invention, an illumination device that emits illumination light, a light modulation device that forms image light by modulating the illumination light according to image information, and projection optics that projects the image light And a projector in which the illumination device is the illumination device according to the first aspect.

  Since the projector according to the second aspect includes the light source device according to the first aspect, the projector can perform image display with excellent quality.

It is a top view which shows the optical system of the projector which concerns on 1st embodiment. (A) is a front view of a rotary fluorescent screen, (b) is A1-A1 sectional drawing of (a). It is a top view which shows the optical system of the projector which concerns on 2nd embodiment. It is sectional drawing of the rotation fluorescent screen which concerns on 2nd embodiment. It is sectional drawing of the rotation fluorescent screen which concerns on 3rd embodiment.

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)
An example of the projector according to the present embodiment will be described. The projector of this embodiment is a projection type image display device that displays a color image on a screen (projected surface) SCR. The projector uses three liquid crystal light modulation devices corresponding to red, green, and blue light. The projector uses a semiconductor laser that can obtain light with high luminance and high output as the light source of the illumination device.

FIG. 1 is a top view showing an optical system of the projector according to the present embodiment.
As shown in FIG. 1, the projector 1 includes a first illumination device 100, a second illumination device 102, a color separation light guide optical system 200, liquid crystal light modulation devices 400R, 400G, and 400B, a cross dichroic prism 500, and a projection optical system 600. Is provided.

  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 rotating fluorescent plate (wavelength conversion element) 30, a motor 50, a first lens array 120, and a second lens array. 130, a polarization conversion element 140, and a superimposing lens 150.

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

In the present embodiment, the first light source 10 is arranged so that the optical axis is orthogonal to the illumination optical axis 100ax.
The collimating optical system 70 includes a first lens 72 and a second lens 74, and makes the light from the first light source 10 substantially parallel. The first lens 72 and the second lens 74 are convex lenses.

  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 of the first light source 10 and the illumination optical axis 100ax at an angle of 45 °. Yes. The dichroic mirror 80 reflects the blue light B and allows the yellow fluorescent light Y including red light and green light to pass therethrough.

  The collimator condensing optical system 90 substantially collimates the fluorescence emitted from the rotating fluorescent plate 30 and the function of causing the blue light B from the dichroic mirror 80 to be incident on the phosphor layer 42 of the rotating fluorescent plate 30 in a substantially condensed state. With functions. The collimator condensing optical system 90 includes a first lens 92 and a second lens 94. The first lens 92 and the second lens 94 are convex lenses.

  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 condensing optical system 760 includes a first lens 762 and a second lens 764. The condensing optical system 760 condenses the blue light from the second light source 710 near the scattering plate 732. The first lens 762 and the second lens 764 are convex lenses.

  The scattering plate 732 scatters the blue light from the second light source 710 to obtain blue light B having a light distribution similar to fluorescence (light emitted from the rotating fluorescent plate 30). 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 first lens 772 and the second lens 774 are convex lenses.

  In the present embodiment, the blue light B from the second illumination device 102 is reflected by the dichroic mirror 80 and is combined with the fluorescent light Y that is yellow light from the rotating fluorescent plate 30 that has passed through the dichroic mirror 80 to become white light W. The light enters one lens array 120.

  FIG. 2 is a view for explaining the rotating fluorescent plate according to the embodiment. 2A is a front view of the rotating fluorescent plate 30, and FIG. 2B is a cross-sectional view taken along line A1-A1 of FIG.

  As shown in FIGS. 1 and 2, the rotating fluorescent plate 30 is provided with a phosphor layer (wavelength conversion layer) 42 along the circumference of the disc 40 on a disc (substrate) 40 that can be rotated by a motor 50. It becomes. The phosphor layer 42 has an O-ring shape with an outer diameter of 58 mm and an inner diameter of 48 mm, for example, and has a thickness of 250 μm. The rotating fluorescent plate 30 emits fluorescence Y toward the same side as the side on which the blue light is incident.

  The disc 40 is composed of, for example, an aluminum disc having an outer diameter of 60 mm and a thickness of 0.7 mm.

The phosphor layer 42 is excited by the blue light B from the first light source 10 and emits fluorescence Y. The phosphor layer 42 includes a phosphor 42a and a holding material 42b that holds the phosphor 42a. The phosphor 42 a is made of, for example, (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce, which is a YAG phosphor. As the holding material 42b, it is preferable to use a material having translucency and high thermal conductivity. For example, the holding material 42b is made of an inorganic material such as ceramics or glass. In the present embodiment, for example, low-melting glass is used as the holding material 42b. The holding material 42b only needs to have a light transmission property that allows at least the blue light B and the fluorescence Y to pass therethrough.

  As shown in FIG. 2B, the rotating fluorescent plate 30 has a scattering layer 31 provided on the opposite side to the surface on which the blue light B of the phosphor layer 42 is incident, and the phosphor layer 42 of the scattering layer 31 is opposite. It further includes a reflection film (reflection part) 32 provided on the side, and an adhesive layer 33 provided between the reflection film 32 and the disc 40. That is, the rotating fluorescent plate 30 is a laminate in which the reflective film 32, the scattering layer 31, and the phosphor layer 42 are sequentially laminated upward in FIG. It has an attached structure.

The scattering layer 31 includes a scattering material 31a and a holding material 31b that holds the scattering material 31a. The scattering material 31a is made of, for example, TiO ₂ (titania). The holding material 31b is made of, for example, low-melting glass that is the same material as the holding material 42b of the phosphor layer 42. In this way, since the difference in refractive index at the interface between the scattering layer 31 and the phosphor layer 42 can be eliminated, the refraction and reflection of light (blue light B and fluorescence Y) at the interface can be prevented.

  The reflective film 32 is made of, for example, an Ag alloy. The adhesive layer 33 is, for example, a high thermal conductivity type silicone adhesive containing an Ag filler, and efficiently transfers the heat of the phosphor layer 42 to the disc 40.

Here, an example of a manufacturing method of the rotating fluorescent plate 30 of the present embodiment will be described.
First, the base of the phosphor layer 42 is created. For example, a predetermined amount of low melting point glass powder, phosphor powder, and solvent are mixed to produce a slurry. Then, the slurry is formed into a ring shape as shown in FIG. 2A and then pre-baked (pre-baked).

  Subsequently, the base of the scattering layer 31 is created. For example, a slurry in which a low-melting glass powder, titania powder, and a solvent are mixed in predetermined amounts is generated. And the produced | generated slurry is laminated | stacked on the base of the fluorescent substance layer 42, and temporary baking (prebaking) is carried out, and also baking (baking) is carried out.

  Then, the phosphor layer 42 and the scattering layer 31 having a predetermined shape are formed by grinding. Subsequently, an Ag alloy is formed on the surface of the laminate of the phosphor layer 42 and the scattering layer 31 on the scattering layer 31 side, thereby forming the reflective film 32. Thereby, the laminated body of the fluorescent substance layer 42, the scattering layer 31, and the reflecting film 32 is manufactured. For the purpose of protecting the reflective film 32 made of an Ag alloy, alumina may be formed on the reflective film 32.

  Subsequently, the laminate is bonded to the disk 40 so that the reflective film 32 faces the disk 40 by using a high thermal conductivity type silicone adhesive (adhesive layer 33) containing Ag filler. Then, the rotating fluorescent plate 30 is manufactured by attaching the motor 50 to the disc 40.

  In the present embodiment, since the blue light B made of laser light is incident on the phosphor layer 42, heat is generated in the phosphor 42a. In the present embodiment, the metal disc 40 supports the phosphor layer 42, so that heat generated in the phosphor 42 a of the phosphor layer 42 is radiated from the disc 40.

  Since the phosphor layer 42 of the present embodiment is mainly composed of the holding material 42b made of low melting point glass, the heat of the phosphor 42a can be efficiently transmitted to the disc 40. Thereby, the excessive temperature rise of the fluorescent substance layer 42 can be suppressed, and the fall of the luminous efficiency of the fluorescence Y by a temperature rise can be suppressed.

  On the other hand, since the difference between the refractive index of the holding material 42b (low melting point glass) and the refractive index of the phosphor 42a (YAG phosphor) is small, scattering is difficult to occur while the fluorescence Y propagates in the phosphor layer 42. Become. When scattering does not occur during propagation through the phosphor layer 42, the fluorescence Y easily propagates through the phosphor layer 42. In this case, since the fluorescence Y travels a long distance in the phosphor layer 42 in a direction parallel to the light emission surface 42c of the phosphor layer 42, the spot diameter of the fluorescence Y emitted from the phosphor layer 42 becomes large. , Etendue becomes larger. As a result, the utilization efficiency of the fluorescence Y is reduced.

  On the other hand, in the rotating fluorescent plate 30 of the present embodiment, the phosphor layer 42 from the phosphor layer 42 to the scattering layer 31 by the scattering layer 31 disposed on the surface of the phosphor layer 42 opposite to the blue light B incident surface. The entering fluorescence Y can be scattered.

  The traveling direction of the fluorescence Y scattered by the scattering layer 31 is greatly changed. The scattered fluorescence Y is emitted from the light emission surface 42c before proceeding a long distance in a direction parallel to the light emission surface 42c in the scattering layer 31 and the phosphor layer 42. That is, the fluorescence Y is emitted outside without spreading in a direction parallel to the light emission surface.

  It is also conceivable to mix the scattering material 31a in the phosphor layer 42. In this case, the excitation light that cannot enter the phosphor 42a increases due to the backscattering effect of the scattering material 31a, and the utilization efficiency of the excitation light decreases.

  According to this embodiment, since the scattering layer 31 is provided separately from the phosphor layer 42, backscattering as described above does not occur, and the utilization efficiency of excitation light does not decrease.

Therefore, according to the rotating fluorescent plate 30 of the present embodiment, the fluorescence emitted from the phosphor layer 42 even when the phosphor layer 42 containing an inorganic material (low melting point glass) excellent in heat dissipation is adopted. Expansion of the Y spot diameter can be suppressed. Therefore, increase in etendue can be suppressed, and the fluorescence Y can be efficiently used as image light of the projector.
Further, the fluorescence Y that has traveled in the direction toward the disc 40 is reflected by the reflective film 32 and is emitted from the light exit surface 42c. Therefore, the fluorescence Y can be used efficiently.

  Returning to FIG. 1, the first lens array 120 includes a plurality of first small lenses 122 for dividing the light from the collimating optical system 60 into a plurality of partial light beams. The plurality of first small 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 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 in the vicinity of the image forming area of the liquid crystal light modulators 400R, 400G, and 400B. The plurality of second small lenses 132 are arranged in a matrix in a plane orthogonal to the illumination optical axis 100ax.

  The polarization conversion element 140 converts each partial light beam divided by the first lens array 120 into linearly polarized light. The polarization conversion element 140 transmits one linear polarization component of the polarization components included in the light from the rotating fluorescent plate 30 as it is and reflects the other linear polarization component in a direction perpendicular to the illumination optical axis 100ax, A reflection layer that reflects the other linearly polarized light component reflected by the polarization separation layer in a direction parallel to the illumination optical axis 100ax, and a position that converts the other linearly polarized light component reflected by the reflective layer into one linearly polarized light component. And a phase difference plate.

  The superimposing lens 150 condenses the partial light beams from the polarization conversion element 140 and superimposes them in the vicinity of the image forming regions of the liquid crystal light modulation devices 400R, 400G, and 400B. The first lens array 120, the second lens array 130, and the superimposing lens 150 constitute an integrator optical system that makes the in-plane light intensity distribution of the light from the rotating fluorescent plate 30 uniform.

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 from the first illumination device 100 and the second illumination device 102 into red light R, green light G, and blue light B, and the red light, green light, and blue light. The light is guided to the corresponding liquid crystal light modulation devices 400R, 400G, and 400B.
Condensing lenses 300R, 300G, and 300B are disposed between the color separation light guide optical system 200 and the liquid crystal light modulation devices 400R, 400G, and 400B.

The dichroic mirror 210 is a dichroic mirror that transmits a red light component and reflects a green light component and a blue light component.
The dichroic mirror 220 is a dichroic mirror that reflects a green light component and transmits a blue light component.
The reflection mirror 230 is a reflection mirror that reflects a red light component.
The reflection mirrors 240 and 250 are reflection mirrors that reflect blue light components.

The red light that has passed through the dichroic mirror 210 is reflected by the reflecting mirror 230, passes through the condenser lens 300R, and enters the image forming area of the liquid crystal light modulation device 400R for red light.
The green light reflected by the dichroic mirror 210 is further reflected by the dichroic mirror 220, passes through the condenser lens 300G, and enters the image forming area of the liquid crystal light modulation device 400G for green light.
The blue light that has passed through the dichroic mirror 220 passes through the relay lens 260, the incident-side reflecting mirror 240, the relay lens 270, the exit-side reflecting mirror 250, and the condensing lens 300B to form an image of the liquid crystal light modulation device 400B for blue light. Incident into the area.

  The liquid crystal light modulation devices 400R, 400G, and 400B modulate incident color light according to image information to form a color image. Although not shown, an incident-side polarizing plate is disposed between each condenser lens 300R, 300G, 300B and each liquid crystal light modulator 400R, 400G, 400B, and each liquid crystal light modulator 400R, Between the 400G and 400B and the cross dichroic prism 500, an exit side polarizing plate is disposed.

  The cross dichroic prism 500 is an optical element that synthesizes the image lights emitted from the liquid crystal light modulators 400R, 400G, and 400B to form a color image.

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

  As described above, according to the projector 1 of the present embodiment, since the phosphor layer 42 has high heat dissipation, the increase in etendue is suppressed, and the first lighting device 100 that can efficiently use the fluorescence Y is provided. High-quality image display with high light utilization efficiency can be performed.

(Second embodiment)
Next, a second embodiment of the present invention will be described. The difference between this embodiment and 1st embodiment is the structure of an illuminating device and a rotation fluorescent plate, and other structures are common. Therefore, in the following description, the configuration of the illumination device and the rotating fluorescent plate will be described. In the following description, the same members and configurations of the above-described embodiment are denoted by the same reference numerals, and detailed description thereof is omitted or simplified.

FIG. 3 is a top view showing the optical system of the projector according to the present embodiment.
As shown in FIG. 3, the projector 11 according to the present embodiment includes an illumination device 103, a color separation light guide optical system 200, liquid crystal light modulation devices 400 R, 400 G, and 400 B, a cross dichroic prism 500, and a projection optical system 600.

  The illumination device 103 includes a light source 13, a condensing optical system 20, a rotating fluorescent plate 34, a motor 50, a collimating optical system 60, a first lens array 120, a second lens array 130, a polarization conversion element 140, and a superimposing lens 150. The light source 13 is composed of the same semiconductor laser as the first light source 10 of the first illumination device 100, and emits blue light B as excitation light.

  The condensing optical system 20 includes a first lens 22 and a second lens 24. The condensing optical system 20 causes the blue light B to be incident on the phosphor layer 42 of the rotating fluorescent plate 34 in a substantially condensed state. In the present embodiment, each of the first lens 22 and the second lens 24 is a convex lens.

  The collimating optical system 60 includes a first lens 62 and a second lens 64, and makes the light from the rotating fluorescent plate 34 substantially parallel. The first lens 62 and the second lens 64 are convex lenses.

  In the present embodiment, the blue light B from the light source 13 enters the phosphor layer 42 from the disk 43 side, and part of the blue light B passes through the phosphor layer 42. In the present embodiment, the phosphor layer 42 converts part of the blue light B from the light source 13 into fluorescence Y, and passes the remaining part of the blue light B without conversion. As a result, the fluorescence Y and the blue light B are combined to become white light W, which is incident on the first lens array 120.

FIG. 4 is a cross-sectional view of the rotating fluorescent plate 34 according to this embodiment.
As shown in FIG. 4, the rotating fluorescent plate 34 of the present embodiment has a phosphor layer 42 provided on a disc (substrate) 43 that can be rotated by a motor 50 along the circumference of the disc 43. The rotating fluorescent plate 34 emits fluorescence Y toward the side opposite to the side on which the blue light B is incident.

  The rotating fluorescent plate 34 is provided between the fluorescent material layer 42 and the circular plate 43, a reflective film 36 that transmits the blue light B and reflects the fluorescent light Y, and a scattering layer 31 provided above the fluorescent material layer 42. And further. That is, the rotating fluorescent plate 34 has a configuration in which the reflective film 36, the phosphor layer 42, and the scattering layer 31 are sequentially laminated on the disc 43 in the upward direction.

  The reflective film 36 is composed of, for example, a dichroic mirror. For example, the reflective film 36 has an optical characteristic of transmitting light having a wavelength smaller than 500 nm and reflecting light having a wavelength of 500 nm or more. That is, the reflective film 36 has an optical characteristic of transmitting the blue light B and reflecting the fluorescence Y.

  The disc 43 is made of a material that transmits the blue light B. As a material of the circular plate 43, for example, quartz glass, crystal, sapphire, optical glass, transparent resin, or the like can be used.

Here, an example of a manufacturing method of the rotating fluorescent plate 34 of the present embodiment will be described.
First, the reflective film 36 is formed on the disc 40. Next, a slurry obtained by mixing predetermined amounts of low melting point glass powder, phosphor powder, and solvent on the reflective film 36 is applied in a ring shape, and then pre-baked (prebaked) to form the base of the phosphor layer 42. create. Subsequently, on the base of the pre-baked phosphor layer 42, for example, a slurry in which a predetermined amount of a low-melting glass powder, titania powder, and a solvent are mixed in a predetermined amount is applied in a ring shape, and then pre-baked (pre-baked) to be a scattering layer. Create 31 bases. Thereafter, the laminate of the base of the phosphor layer 42 and the base of the scattering layer 31 is baked (baked), and the motor 50 is attached to manufacture the rotating phosphor plate 34.

According to the rotating fluorescent plate 34 of the present embodiment, the fluorescence Y can be scattered by the scattering layer 31 disposed on the surface of the phosphor layer 42 opposite to the blue light B incident surface, as in the first embodiment. . Since the scattered fluorescence Y is greatly changed in the traveling direction in the scattering layer 31, it is emitted from the light emitting surface 31c to the outside before proceeding a long distance in the direction parallel to the light emitting surface 31c in the scattering layer 31. Is done.
That is, the fluorescence Y is emitted outside the rotating fluorescent plate 34 without spreading in the direction parallel to the light emission surface 31c.
Therefore, since the increase in etendue is suppressed by suppressing the increase in the spot diameter of the fluorescence Y, the fluorescence Y can be efficiently used as the image light of the projector.

Further, in the rotating fluorescent plate 34 of the present embodiment, the blue light B is incident from one side of the phosphor layer 42 and the fluorescence Y is emitted from the other side of the phosphor layer 42. Therefore, as in the first embodiment. In addition, a dichroic mirror for separating the blue light B and the fluorescence Y is not required. Therefore, the increase in the number of parts and the restrictions on the parts layout are reduced.
Therefore, it is possible to reduce the size of the illumination device 103 including the rotating fluorescent plate 34.

(Third embodiment)
Subsequently, a third embodiment of the present invention will be described. The difference between the present embodiment and the first embodiment is the configuration of the rotating fluorescent plate, and other configurations are common. Therefore, in the following description, the configuration of the rotating fluorescent plate will be mainly described. In the following description, the same members and configurations of the above-described embodiment are denoted by the same reference numerals, and detailed description thereof is omitted or simplified.

FIG. 5 is a cross-sectional view of the rotating fluorescent plate 37 according to the present embodiment.
As shown in FIG. 5, the rotating fluorescent plate 37 of the present embodiment has a reflective film 32 formed on the upper surface of a disc 40, and a scattering layer 51 and a phosphor layer 42 are laminated on the reflective film 32.

The scattering layer 51 of this embodiment includes a scattering material 51a and a holding material 51b that holds the scattering material 51a. The scattering material 51a is made of, for example, TiO ₂ (titania). The holding material 51b is made of, for example, a silicone adhesive. Therefore, the scattering layer 51 has a function as an adhesive. As a result, the phosphor layer 42 has a structure attached to the reflective film 32 by the scattering layer 51.

  As the silicone adhesive constituting the holding material 51b, it is preferable to use a material having a refractive index substantially equal to that of the holding material 42b of the phosphor layer 42. In this way, since the difference in refractive index at the interface between the scattering layer 51 and the phosphor layer 42 is reduced, the refraction and reflection of light (blue light B and fluorescence Y) at the interface is suppressed.

In order to manufacture the rotating fluorescent plate 37 of the present embodiment, the phosphor layer 42 is formed by baking as in the first embodiment. A disk 40 on which the reflective film 32 is formed is prepared.
Subsequently, the phosphor layer 42 is adhered to the reflective film 32 on the disc 40 using the scattering layer 51 in which titania powder is dispersed in a silicone adhesive, and then the rotating phosphor plate 30 is manufactured by attaching the motor 50. The

According to the rotating fluorescent plate 37 of the present embodiment, since the fluorescence Y is scattered by the scattering layer 51, the increase in the spot diameter of the fluorescence Y is suppressed, and the increase in etendue is suppressed. Therefore, the fluorescence Y can be efficiently used as the image light of the projector.
Furthermore, according to this embodiment, since the scattering layer 51 functions as an adhesive, the number of parts can be reduced. Further, the rotating fluorescent plate 37 can be easily manufactured as compared with the first embodiment.

  In addition, this invention is not necessarily limited to the thing of the said embodiment, A various change can be added in the range which does not deviate from the meaning of this invention.

  For example, in the above embodiment, the case where the low melting point glass is used as the holding material 42b of the phosphor layer 42 is described as an example, but ceramics may be used. Moreover, in the said embodiment, although the several titania particle was illustrated as the scattering material 31a of the scattering layer 31, and the scattering material 51a of the scattering layer 51, this invention is not limited to this. For example, the scattering material may be a bubble.

  In the above-described embodiment, the projector 1 including the three liquid crystal light modulation devices 400R, 400G, and 400B is illustrated. However, the projector 1 can be applied to a projector that displays a color image with one liquid crystal light modulation device. A digital mirror device may be used as the light modulation device.

  Moreover, although the example which mounted the illuminating device by this invention in the projector was shown in the said embodiment, it is not restricted to this. The lighting device according to the present invention can also be applied to lighting fixtures, automobile headlights, and the like.

  DESCRIPTION OF SYMBOLS 1,11 ... Projector, 10 ... 1st light source, 13 ... Light source, 31 ... Scattering layer, 31a ... Scattering material (a plurality of particles), 40 ... Disc (metal substrate), 42 ... Phosphor layer, 42a ... Phosphor , 43: Disc (transparent substrate), 51: Scattering layer, 51a: Scattering material (plural particles), 100: First illumination device, 103: Illumination device, 400R, 400G, 400B ... Liquid crystal light modulation device (light modulation) Apparatus), 600... Projection optical system.

Claims (6)

A light emitting element that emits excitation light;
A phosphor layer that emits fluorescence when the excitation light is incident;
A scattering layer provided on the opposite side to the surface on which the excitation light of the phosphor layer is incident, and including a plurality of particles;
A light source device comprising: The light source device according to claim 1, further comprising: a metal substrate provided on a side of the scattering layer opposite to the phosphor layer; and a reflection unit provided between the scattering layer and the metal substrate. The light source device according to claim 2, wherein the scattering layer joins the metal substrate and the phosphor layer. A transparent substrate that is provided on the opposite side of the phosphor layer from the scattering layer and transmits the excitation light;
A reflective film that is provided between the phosphor layer and the transparent substrate and transmits the excitation light and reflects the fluorescence;
The light source device according to claim 1. The light source device according to claim 1, wherein the phosphor layer is made of a composite material of an inorganic material and a phosphor. An illumination device that emits illumination light;
A light modulation device that forms image light by modulating the illumination light according to image information;
A projection optical system for projecting the image light,
The projector is the light source device according to any one of claims 1 to 5.

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