JP2012014972A - Light source device and projector - Google Patents

Abstract

Provided is a light source device that can dissipate a solid light source more efficiently than a conventional light source device, and can extend its life.
An excitation light generation unit having a plurality of solid light sources that generate excitation light and a plurality of collimator lenses that substantially parallelize the excitation light generated by the plurality of solid light sources, respectively. An excitation light reflecting unit 50 having an excitation light reflecting surface that reflects light in a predetermined direction, a condensing optical system 60 that condenses the excitation light at a predetermined condensing position, and fluorescence that generates fluorescence from the excitation light. A light source device having a layer 72, and a fluorescence generation unit 70 that emits divergent light having at least fluorescence and having a Lambertian distribution, wherein the excitation light reflecting surface has a central portion including the optical axis of the divergent light removed The light source device 10 has a ring shape, and the plurality of solid light sources 34 are arranged in a ring shape corresponding to the shape of the excitation light reflecting surface.
[Selection] Figure 2

Description

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

  Conventionally, a plurality of solid-state light sources that generate excitation light, a fluorescent layer that is located at a condensing position where excitation light generated by the plurality of solid-state light sources is collected, and that emits fluorescence from the excitation light, and is emitted from the fluorescent layer There is known a light source device including a condensing optical system that substantially collimates divergent light including fluorescent light. Moreover, a projector provided with such an illumination device is known (for example, refer to Patent Document 1). According to the conventional light source device, since the fluorescence is generated in the fluorescent layer located at the condensing position where the excitation light from the plurality of solid state light sources is condensed, the light amount is increased without increasing the area of the light emitting region. Accordingly, the luminance of the light source device can be increased without reducing the light use efficiency.

JP 2004-327361 A

  However, in the conventional light source device, since a plurality of solid light sources are arranged around the condensing optical system, the temperature of the solid light source tends to increase due to radiant heat from the fluorescent layer. Since it is difficult to dispose a heat dissipation member of an appropriate size for each solid light source due to physical limitations, it is difficult to efficiently dissipate heat from the solid light source, and the life of the light source device may be shortened. is there.

  Therefore, the present invention has been made to solve the above-described problems, and can dissipate a solid light source more efficiently than a conventional light source device, thereby prolonging the lifetime. An object of the present invention is to provide a possible light source device. It is another object of the present invention to provide a projector that includes such a light source device and has a long lifetime.

[1] A light source device of the present invention is provided corresponding to a plurality of solid light sources that generate excitation light and the plurality of solid light sources, and substantially parallelizes the excitation light generated by the plurality of solid light sources. An excitation light generation unit having a plurality of collimator lenses, an excitation light reflection unit having an excitation light reflection surface that reflects the excitation light emitted from the excitation light generation unit in a predetermined direction, and the excitation A condensing optical system that condenses the excitation light reflected by the light reflecting portion at a predetermined condensing position, and the excitation light that is located near the condensing position and is condensed by the condensing optical system. A fluorescence generation unit that includes a fluorescence layer that generates fluorescence, and a reflection member that is positioned on the opposite side of the light collection optical system in the fluorescence layer, and that emits divergent light having at least the fluorescence and having a Lambertian distribution. A light source device comprising: The light reflecting surface has a ring shape from which a central portion including the optical axis of the diverging light is removed, and the plurality of solid light sources are arranged in a ring shape corresponding to the shape of the excitation light reflecting surface. It is characterized by being.

  For this reason, according to the light source device of the present invention, the excitation light from the excitation light generation unit is made incident on the fluorescent layer through the excitation light reflecting surface, so that the plurality of solid light sources are separated from the condensing optical system. Can be arranged. As a result, the light source device of the present invention can perform heat radiation of the solid light source more efficiently than the case of the conventional light source device, and thus becomes a light source device capable of extending the lifetime.

  In addition, according to the light source device of the present invention, the excitation light reflecting surface has a ring shape from which the central portion including the optical axis of the diverging light is removed, and thus the divergence of the central portion having a higher light density than the peripheral portion. Light can be emitted as it is from the light source device.

  In addition, according to the light source device of the present invention, as in the conventional light source device, the fluorescence is generated in the fluorescent layer located at the condensing position where the excitation light from the plurality of solid state light sources is collected. The amount of light can be increased without increasing the area of the region, and the luminance of the light source device can be increased without reducing the light use efficiency.

In this specification, the “ring shape” includes not only a shape having a circular outer shape but also a shape having an outer shape such as an ellipse or a polygon, and in short, includes an optical axis of diverging light. The general shape with the central part removed.
In addition, as long as the central portion including the optical axis of diverging light is removed, the shape may not be integrated. For example, it may be composed of a plurality of small pieces having a circular outer shape as a whole.

[2] In the light source device of the present invention, the solid-state light source is preferably composed of a semiconductor laser.

Since the semiconductor laser is small and has high output, the light source apparatus having a small size and high output can be obtained by adopting the above-described configuration.
In addition, since a semiconductor laser emits laser light with good light condensing properties, the configuration as described above facilitates the reduction of the area of the excitation light reflecting surface, and fluorescence is emitted from the excitation light reflecting portion. It is possible to suppress a decrease in light utilization efficiency due to the fact that the light is emitted.

[3] In the light source device of the present invention, the solid-state light source generates blue light as the excitation light, and the fluorescent layer generates fluorescence including red light and green light from a part of the blue light, It is preferable that the fluorescence generation unit emits divergent light including blue light that is scattered or reflected without involving the generation of the fluorescence together with the fluorescence, and the light source device emits white light as a whole.

  With such a configuration, the light source device can emit white light using a solid light source that generates blue light.

[4] In the light source device of the present invention, the excitation light reflecting section is composed of a polarization beam splitter that reflects light composed of one polarization and transmits light composed of the other polarization, and is emitted from the excitation light generation section. It is preferable that the excitation light is configured to enter the excitation light reflecting portion as excitation light composed of the one polarized light.

Of the diverging light incident on the excitation light reflecting surface, the divergent light composed of the other polarized light can be passed through and used, so that the configuration described above allows fluorescence to be emitted at the excitation light reflecting unit. Accordingly, it is possible to further suppress a decrease in light utilization efficiency due to the above.
In addition, for divergent light incident on the excitation light reflecting surface, the color balance does not change before and after passing through the excitation light reflecting part, so that adjustment of the color balance of light emitted from the light source device should be relatively easy. Is possible.

[5] In the light source device of the present invention, it is preferable that the excitation light reflecting section is composed of a dichroic mirror that reflects light having a wavelength corresponding to the excitation light and transmits light having a wavelength corresponding to the fluorescence.

Of the diverging light incident on the excitation light reflecting surface, it is possible to use the fluorescent light by passing through it. It is possible to further suppress a decrease in the use efficiency of the.
In addition, since the excitation light emitted from the excitation light generation unit and incident on the excitation light reflection unit does not have to be polarized light, the degree of freedom in designing the light source device can be increased.

[6] In the light source device of the present invention, it is preferable that the excitation light reflecting section is formed of a reflecting mirror.

With such a configuration, it is possible to make the excitation light reflecting section simple and to adjust the color balance of light emitted from the light source device relatively easily.
In the above case, all the diverging light incident on the excitation light reflecting surface is lost and cannot be used as light emitted from the light source device, but the central portion including the optical axis of the diverging light on the excitation light reflecting surface. By removing sufficiently large, divergent light that cannot be used as light emitted from the light source device can be reduced.

  The “reflection mirror” is a so-called general total reflection mirror, which reflects light having a wavelength in a wide range including at least light having a wavelength corresponding to excitation light and light having a wavelength corresponding to fluorescence. .

[7] In the light source device of the present invention, it is preferable that irregularities are formed on the surface of the fluorescent layer.

  By adopting such a configuration, it is possible to promote the diffusion and reflection of light in the fluorescent layer, and to make the Lambertian distribution of diverging light more appropriate.

[8] In the light source device of the present invention, it is preferable that the fluorescence generation unit is disposed at a position where the excitation light condensed by the condensing optical system enters the fluorescent layer in a defocused state. .

  By adopting such a configuration, it is possible to obtain a large amount of fluorescent light without giving an excessive thermal load to the fluorescent layer, thereby suppressing deterioration and burning of the fluorescent layer and extending the lifetime further. It becomes a possible light source device.

[9] A projector according to the present invention projects an illumination device including the light source device according to the present invention, a light modulation device that modulates light from the illumination device in accordance with image information, and modulated light from the light modulation device. And a projection optical system for projecting.

  According to the projector of the present invention, since the light source device of the present invention capable of increasing the luminance without reducing the light use efficiency and extending the lifetime, the luminance is high, and It becomes a projector with a long life of the light source device.

FIG. 2 is a plan view showing an optical system of the projector 1000 according to the first embodiment. The figure shown in order to demonstrate the light source device 10 which concerns on Embodiment 1. FIG. The figure shown in order to demonstrate the flow of the light in the light source device 10 which concerns on Embodiment 1. FIG. 3 is a graph showing the light emission intensity characteristics of the solid light source 34 and the light emission intensity characteristics of the phosphor in the first embodiment. The figure shown in order to demonstrate the light source device 12 which concerns on Embodiment 2. FIG. The figure shown in order to demonstrate the flow of the light in the light source device 12 which concerns on Embodiment 2. FIG. The figure shown in order to demonstrate the light source device 14 which concerns on the modification 1. As shown in FIG. The figure shown in order to demonstrate the flow of the light in the light source device 16 which concerns on the modification 2. As shown in FIG. The figure shown in order to demonstrate the flow of the light in the light source device 18 which concerns on the modification 3. As shown in FIG.

  Hereinafter, a light source device and a projector of the present invention will be described based on the embodiments shown in the drawings.

[Embodiment 1]
FIG. 1 is a plan view showing an optical system of a projector 1000 according to the first embodiment. In FIG. 1, the solid light source array 30, the collimator lens array 40, and the excitation light reflecting unit 50 are displayed as a cross-sectional view cut along a plane that intersects the illumination optical axis 100 ax. The same applies to FIGS. 3, 6, 8 and 9, which will be described later.
FIG. 2 is a diagram for explaining the light source device 10 according to the first embodiment. 2A is a perspective view of the light source device 10, FIG. 2B is a view of the solid light source array 30 viewed from the collimator lens array 40 side, and FIG. FIG.

FIG. 3 is a diagram for explaining the flow of light in the light source device 10 according to the first embodiment. FIG. 3A is a diagram illustrating the flow of light until the excitation light (blue light) generated by the solid light source 34 reaches the fluorescent layer 72, and FIG. 3B is the divergence from the fluorescence generation unit 70. It is a figure which shows the flow of light until light (red light, green light, and blue light) reaches | attains the excitation light reflection part 50, FIG.3 (c) shows the flow of light after FIG.3 (b). FIG.
FIG. 4 is a graph showing the emission intensity characteristics of the solid-state light source 34 and the emission intensity characteristics of the phosphor in the first embodiment. 4A is a graph showing the emission intensity characteristics of the solid-state light source 34, and FIG. 4B is a graph showing the emission intensity characteristics of the phosphor contained in the fluorescent layer 72. The light emission intensity characteristic is a characteristic of how much light is emitted with what intensity when a voltage is applied for a light source and excitation light is incident for a phosphor. Say. The vertical axis of the graph represents relative light emission intensity, and the light emission intensity at the wavelength where the light emission intensity is strongest is 1. The horizontal axis of the graph represents the wavelength.

In each drawing, the symbol R indicates red light, the symbol G indicates green light, and the symbol B indicates blue light. In addition, what is appended with (p) at the end of the code indicating each color light is light composed of p-polarized light, and what is appended with (s) is light composed of s-polarized light. What is not attached is light composed of both p-polarized light and s-polarized light.
In the present specification and drawings, description and illustration of components that are not directly related to the optical system (such as a housing and a fixture for fixing the components) are omitted.

  As shown in FIG. 1, the projector 1000 according to the first embodiment includes an illumination device 100, a color separation light guide optical system 200, three liquid crystal light modulation devices 400R, 400G, and 400B as light modulation devices, and a cross dichroic. A prism 500 and a projection optical system 600 are provided.

  The illumination device 100 includes a light source device 10, a first lens array 120, a second lens array 130, a polarization conversion element 140, and a superimposing lens 150. The lighting device 100 emits white light including red light, green light, and blue light.

As illustrated in FIGS. 1 and 2A, the light source device 10 includes an excitation light generation unit 20, an excitation light reflection unit 50, a condensing optical system 60, and a fluorescence generation unit 70.
The excitation light generation unit 20 includes a solid light source array 30 and a collimator lens array 40.

As shown in FIG. 2B, the solid light source array 30 includes a substrate 32 and 24 solid light sources 34 that generate blue light as excitation light. In the solid light source array 30, the 24 solid light sources 34 are arranged in a circular ring shape corresponding to the shape (described later) of the excitation light reflecting surface 50. In FIG. 2B, only one solid light source 34 is denoted by a reference numeral.
In the present invention, the number of solid light sources is not limited to 24, but may be plural, that is, two or more.

  The substrate 32 has a function of mounting the solid light source 34. Although detailed description is omitted, the substrate 32 has a function of mediating supply of electric power to the solid light source 34, a function of radiating heat generated by the solid light source 34, and the like.

The solid-state light source 34 is composed of a semiconductor laser that generates blue light (emission intensity peak: about 460 nm, see FIG. 4A). As shown in FIG. 2B, the semiconductor laser has a rectangular light emitting region. The size of the light emitting region in the semiconductor laser is, for example, a long side of 8 μm and a short side of 2 μm. As the semiconductor laser, a semiconductor laser in which the divergence angle along the short side direction of the light emitting region is three times or more the divergence angle along the long side direction of the light emitting region can be suitably used.
The solid light source 34 generates blue light composed of s-polarized light as excitation light composed of one polarized light. For this reason, the blue light emitted from the excitation light generating unit 20 enters the light reflecting unit 50 as blue light composed of s-polarized light. In order for the excitation light emitted from the excitation light generation unit to enter the excitation light reflection unit as excitation light composed of s-polarized light, a solid-state light source that generates excitation light composed of s-polarized light as described above is used. In addition to use, a solid light source that emits excitation light composed of p-polarized light and a λ / 2 plate may be used.

As shown in FIGS. 1 and 2A, the collimator lens array 40 is disposed in the vicinity of the solid light source array 30, and substantially collimates the blue light generated by the 24 solid light sources 34, respectively. Each collimator lens 42 is provided. The 24 collimator lenses 42 are arranged in a circular ring shape corresponding to the 24 solid light sources 34. The collimator lens 42 is a plano-convex lens having a convex side facing the solid light source 34 side.
As the collimator lens, a plano-convex lens whose plane side faces the solid light source side may be used.

As shown in FIGS. 1, 2A, and 2C, the excitation light reflection unit 50 reflects the blue light emitted from the excitation light generation unit 20 in a predetermined direction. Have The excitation light reflecting surface has a ring shape from which a central portion including a diverging light optical axis 70ax, which will be described later, is removed, and more specifically, a circular outer shape formed integrally.
The excitation light reflecting unit 50 includes a polarization beam splitter that reflects light composed of s-polarized light and transmits light composed of p-polarized light. In FIG. 2C, reference numeral L (displayed only on one of the upper right side) indicates a position where light from the excitation light generation unit 20 is incident. The same applies to FIGS. 5C and 7B described later.

The condensing optical system 60 condenses the blue light reflected by the excitation light reflecting unit 50 at a predetermined condensing position. Further, the divergent light emitted from the fluorescence generation unit 70 is made substantially parallel.
The condensing optical system 60 includes a first lens 62 and a second lens 64 as shown in FIGS. 1 and 2A.
The first lens 62 and the second lens 64 are biconvex lenses. Note that the shapes of the first lens and the second lens are not limited to the above shapes. In short, the condensing optical system including the first lens and the second lens is reflected by the excitation light reflecting unit 50. Any shape may be used as long as the excitation light is condensed at a predetermined condensing position. Further, the number of lenses constituting the condensing optical system may be one, or may be three or more.

The fluorescence generation unit 70 is located in the vicinity of the light collection position of the light collection optical system 60, and generates a fluorescence from a part of the blue light collected by the light collection optical system 60. And a reflection member 74 located on the opposite side of the condensing optical system 60. The fluorescence generation unit 70 emits divergent light having a Lambertian distribution, including blue light scattered or reflected without being involved in the generation of fluorescence together with the fluorescence. In the figure, reference numeral 70ax indicates the optical axis of the diverging light.
The fluorescence generation unit 70 is disposed at a position where the blue light condensed by the condensing optical system 60 enters the fluorescent layer 72 in a defocused state.

The fluorescent layer 72 is a layer containing (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce, which is a YAG-based phosphor. The fluorescent layer may be composed of a layer containing a YAG phosphor other than (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce, or a layer containing a silicate phosphor. Or a layer containing a TAG phosphor. Further, it comprises a layer containing a mixture of a phosphor that converts main excitation light into red light (for example, CaAlSiN ₃ red phosphor) and a phosphor that converts main excitation light into green (for example, β sialon green phosphor). It may be a thing.
The fluorescent layer 72 converts part of the blue light emitted from the excitation light generation unit 20 into fluorescence containing red light (emission intensity peak: about 610 nm) and green light (emission intensity peak: about 550 nm). Injection is performed (see FIG. 4B).
Fine irregularities are formed on the surface of the fluorescent layer 72.

The reflecting member 74 is made of an aluminum plate whose mirror surface is processed on the side in contact with the fluorescent layer 72. In addition, the reflecting member in the present invention is not limited to the above-mentioned ones, and various metal plates and glass plates having a reflecting surface can be used. From the viewpoint of heat dissipation, various metal plates can be used. It is preferable to use what consists of.
In addition, for example, a reflective member having so-called reflective scattering characteristics, which can be manufactured by forming a reflective surface after roughening the side in contact with the fluorescent layer, can also be used. As a specific example, a reflective member manufactured by forming a dielectric multilayer film on the surface of optical glass (that is, polished glass) whose surface that is in contact with the fluorescent layer is roughened can be used. By adopting such a configuration, it is possible to promote the diffusion and reflection of light even in the reflecting member, and to further improve the Lambertian distribution of diverging light.

Here, the flow of light in the light source device 10 will be described with reference to FIG.
First, as shown in FIG. 3A, the blue light generated by the 24 solid light sources 34 is substantially collimated by the 24 collimator lenses 42, respectively. Thereafter, the blue light is reflected by the excitation light reflecting surface of the excitation light reflecting unit 50, is collected by the condensing optical system 60, and enters the fluorescent layer 72 in a defocused state.

A part of the blue light is converted into fluorescence including red light and green light in the fluorescent layer 72, and the remaining part of the blue light is scattered or reflected without being related to the generation of the fluorescence, as divergent light having a Lambertian distribution. Injected with fluorescence. As shown in FIG. 3B, the divergent light is substantially collimated by the condensing optical system 60 and is incident on the excitation light reflecting unit 50. Thereafter, as shown in FIG. 3C, the diverging light composed of p-polarized light that has entered the excitation light reflection surface of the excitation light reflection unit 50 passes through the excitation light reflection surface. On the other hand, the divergent light composed of s-polarized light that has entered the excitation light reflecting surface of the excitation light reflection unit 50 is reflected to the excitation light generation unit 20 side and excluded outside the system.
The above is the flow of light in the light source device 10.

  As shown in FIG. 1, the first lens array 120 includes a plurality of first small lenses 122 for dividing the light from the light source device 10 into a plurality of partial light beams. The first lens array 120 has a function as a light beam splitting optical element that splits light from the light source device 10 into a plurality of partial light beams, and the plurality of first small lenses 122 are in a plane orthogonal to the illumination optical axis 100ax. It has a configuration arranged in a matrix of multiple rows and multiple columns. Although not illustrated, the outer shape of the first small lens 122 is substantially similar to the outer shape of the image forming regions of the liquid crystal light modulation devices 400R, 400G, and 400B.

  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 has a function of forming an image of each first small lens 122 of the first lens array 120 in the vicinity of the image forming region of the liquid crystal light modulators 400R, 400G, and 400B together with the superimposing lens 150. The second lens array 130 has a configuration in which a plurality of second small lenses 132 are arranged in a matrix of a plurality of rows and a plurality of columns in a plane orthogonal to the illumination optical axis 100ax.

The polarization conversion element 140 is a polarization conversion element that emits the polarization direction of each partial light beam divided by the first lens array 120 as approximately one type of linearly polarized light having a uniform polarization direction.
The polarization conversion element 140 transmits the other linearly polarized light component as it is among the polarized light components included in the light from the light source device 10, and reflects the one linearly polarized light component in a direction perpendicular to the illumination optical axis 100ax. A reflection layer that reflects one linear polarization component reflected by the polarization separation layer in a direction parallel to the illumination optical axis 100ax, and a position that converts one linear polarization component reflected by the reflection layer into the other linear polarization component. And a phase difference plate.

The superimposing lens 150 superimposes each partial light beam from the polarization conversion element 140 in the illuminated area. The superimposing lens 150 is an optical element for condensing the partial light flux and superimposing it on the vicinity of the image forming area of the liquid crystal light modulation devices 400R and 400G. The superimposing lens 150 is arranged so that the optical axis of the superimposing lens 150 and the optical axis of the illumination device 100 substantially coincide with each other. The superimposing lens 150 may be composed of a compound lens in which a plurality of lenses are combined. The 1st lens array 120, the 2nd lens array 130, and the superimposition lens 150 comprise the integrator optical system which makes the light from the light source device 10 more uniform as a lens integrator optical system.
Note that a rod integrator optical system including an integrator rod can be used instead of the lens integrator optical system.

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 light from the illumination device 100 into red light, green light, and blue light, and the respective color lights of red light, green light, and blue light are liquid crystal light modulation devices 400R that are illumination targets. , 400G, 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 mirrors 210 and 220 are mirrors in which a wavelength selective transmission film that reflects light in a predetermined wavelength region and passes light in other wavelength regions is formed on a substrate.
The dichroic mirror 210 is a dichroic mirror that reflects a red light component and transmits green light and blue light components.
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 reflected by the dichroic mirror 210 is reflected by the reflection mirror 230, passes through the condenser lens 300R, and enters the image forming region of the liquid crystal light modulation device 400R for red light.
The green light that has passed through the dichroic mirror 210 is 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 reflection mirror 240, the relay lens 270, the emission-side reflection mirror 250, and the condensing lens 300B. Incident into the area. The relay lenses 260 and 270 and the reflection mirrors 240 and 250 have a function of guiding the blue light component transmitted through the dichroic mirror 220 to the liquid crystal light modulation device 400B.

  The reason why such a relay lens 260, 270 is provided in the optical path of blue light is that the length of the optical path of blue light is longer than the length of the optical path of other color light, This is to prevent a decrease in usage efficiency. The projector 1000 according to the first embodiment has such a configuration because the length of the optical path of blue light is long. However, the length of the optical path of red light is increased, and the relay lenses 260 and 270 and the reflection mirror are configured. A configuration using 240 and 250 in the optical path of red light is also conceivable.

The liquid crystal light modulation devices 400R, 400G, and 400B form color images by modulating incident color light according to image information, and are illumination targets of the illumination device 100. Although not shown in the figure, an incident-side polarizing plate is interposed between each condenser lens 300R, 300G, 300B and each liquid crystal light modulator 400R, 400G, 400B, and each liquid crystal light modulator 400R. , 400G, 400B and the cross dichroic prism 500 are respectively provided with exit side polarizing plates. The incident-side polarizing plates, the liquid crystal light modulation devices 400R, 400G, and 400B and the exit-side polarizing plate modulate the light of each incident color light.
The liquid crystal light modulators 400R, 400G, and 400B are transmissive liquid crystal light modulators in which a liquid crystal that is an electro-optical material is hermetically sealed in a pair of transparent glass substrates. In accordance with the received image signal, the polarization direction of one type of linearly polarized light emitted from the incident side polarizing plate is modulated.

  The cross dichroic prism 500 is an optical element that forms a color image by synthesizing an optical image modulated for each color light emitted from the emission side polarizing plate. 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 dielectric multilayer film formed at one of the substantially X-shaped interfaces reflects red light, and the dielectric multilayer film formed at the other interface reflects blue light. By these dielectric multilayer films, the red light and the blue light are bent and aligned with the traveling direction of the green light, so that the three color lights are synthesized.

  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.

  Next, effects of the light source device 10 and the projector 1000 according to the first embodiment will be described.

  According to the light source device 10 according to the first embodiment, since the excitation light (blue light) from the excitation light generation unit 20 is incident on the fluorescent layer 72 via the excitation light reflecting surface, the plurality of solid state light sources 34 are used. Can be arranged away from the condensing optical system 60. As a result, the light source device 10 according to Embodiment 1 can perform heat radiation of the solid light source more efficiently than in the case of the conventional light source device, and thus becomes a light source device capable of extending the lifetime. .

  Further, according to the light source device 10 according to the first embodiment, the excitation light reflecting surface has a ring shape from which the central portion including the optical axis of the diverging light is removed, and therefore has a higher light amount density than the peripheral portion. Part of the divergent light can be emitted as it is from the light source device.

  Further, according to the light source device 10 according to the first embodiment, as in the conventional light source device, fluorescence (red light) is present in the fluorescent layer 72 located at the condensing position where the excitation light from the plurality of solid light sources 34 is collected. And green light) can be generated without increasing the area of the light emitting region, and the luminance of the light source device can be increased without lowering the light use efficiency. It becomes.

  Further, according to the light source device 10 according to the first embodiment, since the solid-state light source 34 is made of a semiconductor laser, the light source device is small and has a high output. Further, since the semiconductor laser emits laser light with good condensing property, it becomes easy to reduce the area of the excitation light reflecting surface, and the light use efficiency due to the fluorescence generated by the excitation light reflecting portion 50 is facilitated. Can be suppressed.

  The light source device 10 according to the first embodiment is a light source device that can emit white light using the solid light source 34 that generates blue light.

  Further, according to the light source device 10 according to the first embodiment, the excitation light reflecting unit 50 includes a polarization beam splitter that reflects light composed of s-polarized light and allows light composed of p-polarized light to pass through, and is emitted from the excitation light generation unit 20. Since the excited light is incident on the excitation light reflecting unit 50 as excitation light composed of s-polarized light, it is possible to further suppress a decrease in light use efficiency caused by the fluorescence generated by the excitation light reflecting unit 50. It becomes possible. Further, for divergent light incident on the excitation light reflecting surface, the color balance does not change before and after passing through the excitation light reflecting unit 50, so that adjustment of the color balance of light emitted from the light source device is relatively easy. It becomes possible.

  Further, according to the light source device 10 according to the first embodiment, since the unevenness is formed on the surface of the fluorescent layer 72, the diffusion and reflection of light in the fluorescent layer 72 is promoted, and the Lambertian distribution of diverging light is further increased. It becomes possible to make it appropriate.

  Further, according to the light source device 10 according to the first embodiment, the fluorescence generation unit 70 is disposed at a position where the excitation light condensed by the condensing optical system 60 enters the fluorescent layer 72 in a defocused state. Thus, it is possible to obtain a large amount of fluorescent light without applying an excessive thermal load to the fluorescent layer 72, and it is possible to suppress the deterioration and burning of the fluorescent layer and to further increase the lifetime.

  According to the projector 1000 according to the first embodiment, since the light source device 10 that can increase the luminance without reducing the light utilization efficiency and can extend the lifetime is provided, the luminance is high. And it becomes a projector with a long lifetime of a light source device.

[Embodiment 2]
FIG. 5 is a diagram for explaining the light source device 12 according to the second embodiment. 5A is a perspective view of the light source device 12, FIG. 5B is a view of the solid light source array 31 viewed from the fluorescence generation unit 70 side, and FIG. 5C shows the excitation light reflection unit 52. It is the figure seen from the fluorescence production | generation part 70 side.
FIG. 6 is a diagram for explaining the flow of light in the light source device 12 according to the second embodiment. FIG. 6A is a diagram showing the flow of light until the blue light generated by the solid light source 34 reaches the fluorescent layer 72, and FIG. 6B is a diagram in which divergent light from the fluorescence generating unit 70 is excited light. It is a figure which shows the flow of the light until it reaches | attains the reflection part 52, FIG.6 (c) is a figure which shows the flow of the light after FIG.6 (b).

  The light source device 12 according to the second embodiment basically has the same configuration as the light source device 10 according to the first embodiment, but the configuration of the excitation light generation unit and the excitation light reflection unit is the light source device 10 according to the first embodiment. It is different from the case of. That is, in the light source device 12 according to the second embodiment, as illustrated in FIGS. 5 and 6, an excitation light generation unit that emits light in a direction different from the excitation light generation unit 20 in the first embodiment (so-called inner direction). An excitation light reflecting portion 52 is disposed inside 22.

  Hereinafter, the configuration of the light source device 12 according to the second embodiment will be described in detail. In addition, about the condensing optical system 60 and the fluorescence production | generation part 70, since it has the structure similar to Embodiment 1, description is abbreviate | omitted.

The excitation light generation unit 22 includes a solid light source array 31 and a collimator lens array 41.
The solid light source array 31 includes a substrate 36 and 24 solid light sources 34 as shown in FIGS. In the solid-state light source array 30, the 24 solid-state light sources 34 have a circular ring shape corresponding to the shape of the excitation light reflecting surface 53 (see FIG. 5A) and emit blue light in the inner direction. (Refer to FIG. 6A.)
The substrate 36 has the same configuration as the substrate 32 in the first embodiment except for the shape.
The solid light source 34 has the same configuration as the solid light source 34 in the first embodiment.

  As shown in FIGS. 5A and 6, the collimator lens array 41 includes 24 collimator lenses 42 that substantially parallelize the blue light generated by the 24 solid light sources 34. The 24 collimator lenses 42 have a circular ring shape corresponding to the 24 solid light sources 34, and are arranged so that the convex surface side faces the solid light source 34 side.

As shown in FIGS. 5 (a), 5 (c), and 6, the excitation light reflection unit 52 is an excitation of 24 surfaces that reflects the blue light emitted from the excitation light generation unit 22 in a predetermined direction. A light reflecting surface 53 is provided. The excitation light reflecting surface 53 as a whole has a ring shape from which the central portion including the optical axis 70ax of diverging light is removed, more specifically, a shape having a substantially circular outline.
The excitation light reflection unit 52 includes a polarization beam splitter configured such that the 24 excitation light reflection surfaces 53 reflect excitation light composed of s-polarized light emitted from the corresponding excitation light generation unit 22.

  As described above, the light source device 12 according to the second embodiment is different from the light source device 10 according to the first embodiment in the configuration of the excitation light generation unit and the excitation light reflection unit, but the light source device 10 according to the first embodiment. Similarly, since the excitation light (blue light) from the excitation light generation unit 22 is incident on the fluorescent layer 72 via the excitation light reflecting surface 53, the plurality of solid light sources 34 are separated from the condensing optical system 60. As a result, the light source device 12 according to the second embodiment can also dissipate the solid light source more efficiently than the case of the conventional light source device, thereby extending the life. Thus, the light source device can be used.

  The light source device 12 according to the second embodiment has the same configuration as that of the light source device 10 according to the first embodiment, except that the configurations of the excitation light generation unit and the excitation light reflection unit are different from those of the light source device 10 according to the first embodiment. And having the effect of the light source device 10 according to the first embodiment as it is.

  As mentioned above, although this invention was demonstrated based on said embodiment, this invention is not limited to said embodiment. The present invention can be carried out in various modes without departing from the spirit thereof, and for example, the following modifications are possible.

(1) In each of the above embodiments, the excitation light reflecting portion that is integrally formed is used, but the present invention is not limited to this. FIG. 7 is a view for explaining the light source device 14 according to the first modification. FIG. 7A is a perspective view of the light source device 14, and FIG. 7B is a diagram showing the fluorescence generation of the excitation light reflecting portion 54 composed of a plurality of excitation light reflecting portion pieces 55 (only the upper one is indicated by a symbol). It is the figure seen from the part 70 side. The excitation light reflecting portion small piece 55 has the same configuration as the excitation light reflecting portion 50 in the first embodiment except for the shape. For example, as shown in FIG. 7, an excitation light reflecting section constituted by a plurality of small pieces (excitation light reflecting portion small pieces 55) having a circular outer shape as a whole may be used.

(2) In each of the above-described embodiments, the excitation light reflecting section formed of a polarization beam splitter is used. However, the present invention is not limited to this. FIG. 8 is a view for explaining the flow of light in the light source device 16 according to the second modification. FIG. 8A is a diagram showing the flow of light until the blue light generated by the solid-state light source 34 reaches the fluorescent layer 72, and FIG. 8B shows the diverging light from the fluorescence generating unit 70 as excitation light. It is a figure which shows the flow of the light until it reaches | attains the reflection part 56, FIG.8 (c) is a figure which shows the flow of the light after FIG.8 (b). The light source device 16 according to the modified example 2 is an excitation light reflecting unit including a dichroic mirror that reflects light having a wavelength corresponding to excitation light (blue light) and transmits light having a wavelength corresponding to fluorescence (red light and green light). The configuration is the same as that of the light source device 10 according to the first embodiment except that 56 is used. In the light source device of the present invention, for example, as shown in FIG. 8, an excitation light reflection unit composed of a dichroic mirror that reflects light having a wavelength corresponding to excitation light and transmits light having a wavelength corresponding to fluorescence can be used. Good. Even with such a configuration, it is possible to further suppress a decrease in light utilization efficiency due to fluorescence generated in the excitation light reflecting section. In addition, since the excitation light emitted from the excitation light generation unit and incident on the excitation light reflection unit does not have to be polarized light, the degree of freedom in designing the light source device can be increased.

(3) In each of the above-described embodiments, the excitation light reflecting section formed of a polarization beam splitter is used. However, the present invention is not limited to this. FIG. 9 is a view for explaining the flow of light in the light source device 18 according to the third modification. FIG. 9A is a diagram showing the flow of light until the blue light generated by the solid light source 34 reaches the fluorescent layer 72, and FIG. 9B is a diagram in which divergent light from the fluorescence generating unit 70 is excited light. It is a figure which shows the flow of the light until it reaches | attains the reflection part 58, FIG.9 (c) is a figure which shows the flow of the light after FIG.9 (b). The light source device 18 according to the modified example 3 has the same configuration as that of the light source device 10 according to the first embodiment except that the excitation light reflecting unit 58 including a reflecting mirror is used. In the light source device of the present invention, for example, as shown in FIG. 9, an excitation light reflecting portion made of a reflecting mirror may be used. With such a configuration, it is possible to make the excitation light reflecting section simple and to adjust the color balance of light emitted from the light source device relatively easily.

(4) In each of the above embodiments, the solid-state light source 34 that generates blue light as excitation light, the fluorescent layer 72 that generates fluorescence including red light and green light from part of the blue light, and the generation of fluorescence are not involved. Although the fluorescence generation unit 70 that emits the divergent light including the scattered or reflected blue light together with the fluorescence is used, the present invention is not limited to this. For example, a solid-state light source that generates violet light or ultraviolet light as excitation light, a fluorescent layer that generates color light including red light, green light, and blue light from violet light or ultraviolet light, and fluorescence generation that emits divergent light including only fluorescence May be used. In each of the above embodiments, the light source device is configured to emit white light as a whole, but the present invention is not limited to this. The light source device may be configured to emit light other than white light.

(5) In each of the above embodiments, the solid light source 34 made of a semiconductor laser that generates blue light having a light emission intensity peak of about 460 nm is used. However, the present invention is not limited to this. For example, you may use the solid light source which consists of a semiconductor laser which produces | generates the blue light whose emission intensity peak is 440 nm-450 nm. By adopting such a configuration, it is possible to improve the efficiency of generating fluorescence from blue light in the phosphor.

(6) In each of the above embodiments, the solid light source 34 made of a semiconductor laser is used, but the present invention is not limited to this. For example, you may use the solid light source which consists of a light emitting diode.

(7) In each of the above embodiments, s-polarized light is used as one polarized light and p-polarized light is used as the other polarized light. However, the present invention is not limited to this. It is also possible to use p-polarized light as one polarized light and s-polarized light as the other polarized light.

(8) In each of the above embodiments, the plurality of solid light sources 34 that are components of the solid light source array 30 are used, but the present invention is not limited to this. For example, you may use the some solid light source arrange | positioned independently, respectively.

(9) In each of the above embodiments, the plurality of collimator lenses 42 that are components of the collimator lens array 40 are used, but the present invention is not limited to this. For example, a plurality of collimator lenses arranged independently from each other may be used.

(10) Although the transmissive projector is used in the first embodiment, the present invention is not limited to this. For example, a reflective projector may be used. Here, “transmission type” means that a light modulation device as a light modulation means such as a transmission type liquid crystal display device transmits light, and “reflection type” This means that the light modulation device as the light modulation means, such as a reflective liquid crystal display device, is a type that reflects light. Even when the present invention is applied to a reflective projector, the same effect as that of a transmissive projector can be obtained.

(11) In the first embodiment, the liquid crystal light modulation device is used as the light modulation device of the projector, but the present invention is not limited to this. In general, the light modulation device only needs to modulate incident light according to image information, and a micromirror light modulation device or the like may be used. For example, a DMD (digital micromirror device) (trademark of TI) can be used as the micromirror light modulator.

(12) In the first embodiment, a projector using three liquid crystal light modulation devices has been described as an example. However, the present invention is not limited to this. The present invention can also be applied to a projector using one, two, four or more liquid crystal light modulation devices.

(13) The present invention can be applied to a rear projection type projector that projects from a side opposite to the side that observes the projected image, even when applied to a front projection type projector that projects from the side that observes the projected image. Is also possible.

(14) In each of the above embodiments, the example in which the light source device of the present invention is applied to a projector has been described, but the present invention is not limited to this. For example, the light source device of the present invention can also be applied to other optical devices (for example, an optical disk device, an automobile headlamp, a lighting device, etc.).

DESCRIPTION OF SYMBOLS 10, 12, 14, 16, 18 ... Light source device, 20, 22 ... Excitation light generation part, 30, 31 ... Solid light source array, 32, 36 ... Substrate, 34 ... Solid light source, 40, 41 ... Collimator lens array, 42 ... collimator lens, 50, 52, 54, 56, 58 ... excitation light reflecting part, 53 ... excitation light reflecting surface, 55 ... excitation light reflecting part piece, 60 ... condensing optical system, 62 ... first lens, 64 ... second lens, 70 ... fluorescence generation unit, 70ax ... optical axis of diverging light, 72 ... fluorescent layer, 74 ... reflecting member, 100 ... illuminating device, 100ax ... illumination optical axis, 120 ... first lens array, 122 ... first DESCRIPTION OF SYMBOLS 1 Small lens, 130 ... 2nd lens array, 132 ... 2nd small lens, 140 ... Polarization conversion element, 150 ... Superimposing lens, 200 ... Color separation light guide optical system, 210, 220 ... Dichroic mirror, 230, 240, 2 DESCRIPTION OF SYMBOLS 0 ... Reflection mirror, 260,270 ... Relay lens, 300R, 300G, 300B ... Condensing lens, 400R, 400G, 400B ... Liquid crystal light modulator, 500 ... Cross dichroic prism, 600 ... Projection optical system, 1000 ... Projector, SCR …screen

Claims (9)

Excitation having a plurality of solid-state light sources that generate excitation light and a plurality of collimator lenses that are provided corresponding to the plurality of solid-state light sources and substantially parallelize the excitation light generated by the plurality of solid-state light sources, respectively. A light generator;
An excitation light reflection unit having an excitation light reflection surface that reflects the excitation light emitted from the excitation light generation unit in a predetermined direction;
A condensing optical system for condensing the excitation light reflected by the excitation light reflecting portion at a predetermined condensing position;
A fluorescent layer located in the vicinity of the condensing position and generating fluorescence from the excitation light condensed by the condensing optical system; and a reflecting member located on the opposite side of the condensing optical system in the fluorescent layer; A fluorescence generation unit that emits divergent light having at least the fluorescence and having a Lambertian distribution,
The excitation light reflecting surface has a ring shape from which a central portion including the optical axis of the diverging light is removed,
The plurality of solid-state light sources are arranged in a ring shape corresponding to the shape of the excitation light reflecting surface. The light source device according to claim 1,
The solid-state light source comprises a semiconductor laser. The light source device according to claim 1 or 2,
The solid-state light source generates blue light as the excitation light,
The fluorescent layer generates fluorescence including red light and green light from a part of the blue light,
The fluorescence generation unit emits divergent light including blue light that is scattered or reflected without being involved in the generation of the fluorescence together with the fluorescence,
The light source device emits white light as a whole. In the light source device in any one of Claims 1-3,
The excitation light reflecting unit is composed of a polarization beam splitter that reflects light composed of one polarized light and transmits light composed of the other polarized light,
The light source device, wherein the excitation light emitted from the excitation light generation unit is configured to enter the excitation light reflection unit as excitation light composed of the one polarized light. In the light source device in any one of Claims 1-3,
The light source device according to claim 1, wherein the excitation light reflecting section is formed of a dichroic mirror that reflects light having a wavelength corresponding to the excitation light and transmits light having a wavelength corresponding to the fluorescence. In the light source device in any one of Claims 1-3,
The light source device, wherein the excitation light reflecting portion is composed of a reflecting mirror. In the light source device according to any one of claims 1 to 5,
An unevenness is formed on the surface of the fluorescent layer. In the light source device in any one of Claims 1-6,
The light source device, wherein the fluorescence generation unit is disposed at a position where the excitation light condensed by the condensing optical system enters the fluorescent layer in a defocused state. A lighting device comprising the light source device according to any one of claims 1 to 7,
A light modulation device that modulates light from the illumination device according to image information;
A projector comprising: a projection optical system that projects the modulated light from the light modulation device as a projection image.

Images