JP5375581B2 - Lighting device and projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an illuminator which can achieve high luminance without shortening the life of a solid light source. <P>SOLUTION: The illuminator 100 includes: a first solid light source device 10 which has a first solid light source that emits main exciting light, and a fluorescent layer that changes the main exciting light into fluorescence and emits the fluorescence; and a collimating optical system 20 which includes a first lens 22 and a second lens 24. The illuminator 100 further includes: a second solid light source device 30 which has a second solid light source that emits sub exciting light; and a dichroic prism 50 which is arranged between the first lens 22 and the second lens 24, reflects the sub exciting light toward the fluorescent layer and has a dichroic surface through which the fluorescence passes. In the illuminator 100, the fluorescent layer is configured to change the sub exciting light into fluorescence and emit the fluorescence, and an angle &alpha;, which is formed by the dichroic surface and an optical axis of the first solid light source device 10, satisfies the following relation: 45&deg;&lt;&alpha;&lt;60&deg;. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a lighting device and a projector.

  2. Description of the Related Art Conventionally, an illumination device including a solid light source device having a solid light source that emits excitation light and a fluorescent layer that converts the excitation light into fluorescence and emits the light is known. Moreover, a projector provided with such an illumination device is known (for example, refer to Patent Document 1).

  According to the conventional illumination device, even when a solid light source capable of obtaining only specific color light is used, various color lights can be obtained by converting the light emitted from the solid light source with the fluorescent layer.

JP 2005-274957 A

  By the way, in recent years, the brightness of projectors has been increased, and along with this, the need for increasing the brightness of lighting devices has increased. In order to increase the brightness of the conventional lighting device, a method of applying a higher voltage to the solid state light source can be considered. However, when the luminance of the lighting device is increased using this method, the thermal load is concentrated on one solid-state light source, and the lifetime of the solid-state light source is shortened due to this. For this reason, in the conventional illuminating device, there exists a problem that it is difficult to make an illuminating device high-intensity, without shortening the lifetime of a solid light source.

  Therefore, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide an illuminating device that can increase the brightness without shortening the lifetime of the solid-state light source. Another object of the present invention is to provide a projector having a high brightness with a low replacement frequency of the lighting device because the lighting device is provided.

[1] An illumination device of the present invention includes a first solid-state light source device that includes a first solid-state light source that emits main excitation light, and a fluorescent layer that converts at least a part of the main-excitation light into fluorescence and emits the fluorescence. A first lens that suppresses the spread of light from the first solid-state light source device; and a second lens that substantially collimates the light from the first lens, and is emitted from the first solid-state light source device as a whole. An illumination device including a collimating optical system that collimates light substantially, the second solid light source device having a second solid light source that emits sub excitation light, and the secondary excitation light from the second solid light source device. A condensing optical system that illuminates, and is disposed between the first lens and the second lens, reflects the secondary excitation light emitted from the condensing optical system toward the fluorescent layer, and reflects the fluorescence. Dichroic light having a dichroic surface to pass through And the fluorescent layer is configured to convert the sub-excitation light into the fluorescence and emit the fluorescent light, and the optical axis of the first solid-state light source device and the optical axis of the second solid-state light source device In an included plane, an angle α formed by the dichroic surface and the optical axis of the first solid state light source device satisfies a relationship of “45 ° <α <60 °”.

  For this reason, according to the illuminating device of the present invention, as the light source for exciting the fluorescent layer, two light sources, the first solid light source that emits main excitation light and the second solid light source that emits sub excitation light, are used. Therefore, it is possible to reduce the thermal load applied to the light source as compared with the case of an illumination device that uses one light source as a light source for exciting the fluorescent layer, and as a result, illumination without shortening the life of the light source. It becomes possible to increase the brightness of the apparatus.

  Further, according to the illumination device of the present invention, since the two excitation lights of the main excitation light and the secondary excitation light are converted into fluorescence using a single fluorescent layer, one excitation light is converted to 1 Compared to a lighting device configured to convert to fluorescence using two fluorescent layers, the light emitting area is not particularly large, and therefore the quality of the illumination light beam is reduced due to the large light emitting area. I don't have to.

  Also, according to the illumination device of the present invention, the angle α formed by the dichroic surface and the optical axis of the first solid-state light source device satisfies the relationship “45 ° <α <60 °”. The lighting device can be reduced in size without interfering with the two solid-state light source devices.

  Here, the reason why the angle α formed by the dichroic surface and the optical axis of the first solid-state light source device is “satisfying the relationship of 45 ° <α <60 °” is as follows. When the angle α is 45 ° or less, the “length in the direction along the optical axis of the first solid-state light source device” in the dichroic optical element becomes too long, making it difficult to reduce the size of the illumination device. This is because when the angle α is 60 ° or more, the first solid-state light source device and the second solid-state light source device may interfere with each other.

  From the above viewpoint, it is more preferable that the angle α formed between the dichroic surface and the optical axis of the first solid-state light source device satisfies the relationship “50 ° ≦ α ≦ 55 °”.

[2] In the illumination device of the present invention, the first solid-state light source device emits white light including red light, green light, and blue light, and is a Lambert light emission type white solid-state light source. The main excitation light is , Ultraviolet light, violet light, or blue light, the secondary excitation light is ultraviolet light or violet light, and the dichroic surface reflects light having a wavelength of 440 nm or less and allows light having a wavelength to exceed 440 nm to pass through. It is preferable.

  With such a configuration, it is possible to emit white light from the lighting device with a relatively simple configuration.

[3] The illumination device of the present invention further includes a third solid light source device having a third solid light source disposed so as to face the second solid light source device across the dichroic optical element and emitting blue light. The main excitation light is ultraviolet light, violet light or blue light, the secondary excitation light is ultraviolet light, violet light or blue light, and the fluorescent layer contains red light and green light as fluorescence. It is configured to emit fluorescence, and the dichroic surface preferably reflects light having a wavelength of 500 nm or less and allows light having a wavelength to exceed 500 nm to pass through.

  With such a configuration, it is possible to emit white light with higher luminance using three solid light sources.

[4] In the illumination device of the present invention, it is preferable that the dichroic optical element is composed of a dichroic prism.

  With such a configuration, it is possible to reduce the reflection loss in the dichroic optical element.

[5] In the illumination device of the present invention, an auxiliary prism having an incident surface perpendicular to the optical axis of the second solid light source device is disposed on the second solid light source device side of the dichroic prism. It is preferable.

  By adopting such a configuration, it becomes possible to correctly make the secondary excitation light incident on the dichroic prism.

[6] In the illumination device of the present invention, it is preferable that the auxiliary prism is bonded to the second solid-state light source device side of the dichroic prism.

  With this configuration, it is possible to reduce reflection loss that may occur between the dichroic prism and the auxiliary prism.

[7] In the illumination device of the present invention, it is preferable that the dichroic prism has a shape in which a portion on the second solid light source device side is a surface perpendicular to the optical axis of the second solid light source device.

  Even with such a configuration, it is possible to correctly make the secondary excitation light incident on the dichroic prism.

[8] In the illumination device of the present invention, the dichroic surface is formed of a dielectric multilayer film, and the dielectric multilayer film is a film configuration that gradually changes according to the incident angle of the sub-excitation light incident on the dichroic surface. It is preferable that the secondary excitation light incident on any region of the dichroic surface has substantially the same wavelength and transmittance characteristics.

  By adopting such a configuration, it becomes possible to reflect the sub-excitation light with high reflectance in any region of the dichroic surface.

  In the illumination device of the present invention, the secondary excitation light from the second solid-state light source device is incident on the dichroic surface while being focused by the condensing optical system, as shown in FIG. Reflected towards the layer. For this reason, the magnitude relationship of the incident angle of the secondary excitation light with respect to the dichroic surface shows the same tendency as the magnitude relationship of the incident angle of the main excitation light and the fluorescence with respect to the dichroic surface, and the dielectric multilayer film is in any region of the dichroic surface. The main excitation light or fluorescence incident on the light has substantially the same wavelength / transmittance characteristics. As a result, according to the illumination device of the present invention, it is possible to reflect the main excitation light with a high reflectance and transmit the fluorescence with a high transmittance in any region of the dichroic surface.

[9] In the illumination device of the present invention, a front aspheric surface is formed on the exit surface of the first lens or the entrance surface of the second lens, and a rear aspheric surface is formed on the exit surface of the second lens. The front aspherical surface is formed so that the light flux density distribution of the light emitted from the first solid state light source device is a peripheral portion where the light flux density in the vicinity of the optical axis of the collimating optical system is separated from the optical axis of the collimating optical system. The latter aspherical surface has a function to substantially parallelize the light formed in the predetermined light flux density distribution, In the light emitted from the collimating optical system, the light flux density in the vicinity of the optical axis of the collimating optical system is preferably higher than the light flux density in the peripheral portion away from the optical axis of the collimating optical system.

By the way, when trying to apply the conventional collimating optical system widely used in the illumination device, the light flux density in the vicinity of the optical axis of the collimating optical system in the light emitted from the collimating optical system is different from the optical axis of the collimating optical system. It becomes relatively lower than the light flux density in the distant peripheral part. In such a case, even if an integrator optical system for making the in-plane light intensity distribution of the light emitted from the collimating optical system uniform is arranged in the subsequent stage, it is irradiated with a large angle of the light irradiated to the illuminated area. The proportion of light that is emitted will increase. When such an illuminating device is applied to a projector using a liquid crystal light modulating device with a built-in microlens as a light modulating device, the light irradiated at a large angle among the light irradiated to the illuminated region. There is a problem in that the light utilization efficiency decreases due to the increase in the ratio.
On the other hand, according to the illumination device of the present invention, the light flux density in the vicinity of the optical axis of the collimating optical system in the light emitted from the collimating optical system is the light flux density in the peripheral portion away from the optical axis of the collimating optical system. Therefore, it is possible to increase the proportion of the light irradiated to the illuminated area with a small angle, so that the illuminated area is irradiated with a large angle. The light utilization efficiency does not decrease due to the increase in the ratio of light to be emitted.

  In addition, since the front aspheric surface is formed on the exit surface of the first lens or the entrance surface of the second lens, and the rear aspheric surface is formed on the exit surface of the second lens, two lenses are used as described above. A collimating optical system having various effects can be configured.

  In addition, the incident surfaces in the first lens and the second lens refer to surfaces on which light is incident (surfaces on the side close to the first solid-state light source device). In addition, the emission surfaces of the first lens and the second lens refer to surfaces on the light emission side (surfaces far from the first solid state light source device).

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

  For this reason, according to the projector of the present invention, since the illumination device of the present invention capable of increasing the brightness without shortening the lifetime of the solid-state light source is provided, Become.

  In addition, according to the projector of the present invention, the projector can be downsized without difficulty because the illumination device that can be downsized without causing the first solid state light source device and the second solid state light source device to interfere with each other is provided. It becomes.

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 1st solid light source device 10 and the 2nd solid light source device 30 in Embodiment 1. FIG. FIG. 3 is a top view of the dichroic prism 50 according to the first embodiment. 3 is a graph showing the emission intensity characteristics of the first solid-state light source 14, the emission intensity characteristics of each phosphor, and the emission intensity characteristics of the second solid-state light source 34 in the first embodiment. FIG. 6 is a plan view showing an optical system of a projector 1002 according to a second embodiment. The figure shown in order to demonstrate the 1st solid state light source device 11, the 2nd solid state light source device 31, and the 3rd solid state light source device 70 in Embodiment 2. FIG. 7 is a graph showing the light emission intensity characteristics of the first solid light source 25, the light emission intensity characteristics of the phosphor, the light emission intensity characteristics of the second solid light source 35, and the light emission intensity characteristics of the third solid light source 74 in the second embodiment. FIG. 9 is a plan view showing an optical system of a projector 1004 according to Modification Example 1. FIG. 9 is a plan view showing an optical system of a projector 1006 according to Modification 2.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an illumination device and a projector of the present invention will be described based on 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.
FIG. 2 is a diagram for explaining the first solid-state light source device 10 and the second solid-state light source device 30 in the first embodiment. 2A is a cross-sectional view of the first solid-state light source device 10, and FIG. 2B is a cross-sectional view of the second solid-state light source device 30.
FIG. 3 is a top view of the dichroic prism 50 according to the first embodiment.
FIG. 4 is a graph showing the emission intensity characteristics of the first solid-state light source 14, the emission intensity characteristics of each phosphor, and the emission intensity characteristics of the second solid-state light source 34 in the first embodiment. 4A is a graph showing the light emission intensity characteristics of the first solid-state light source 14, and FIG. 4B is a graph showing the light emission intensity characteristics of the red phosphor contained in the fluorescent layer 16, and FIG. ) Is a graph showing the emission intensity characteristics of the green phosphor contained in the phosphor layer 16, and FIG. 4D is a graph showing the emission intensity characteristics of the blue phosphor contained in the phosphor layer 16. FIG. ) Is a graph showing the emission intensity characteristics of the second solid-state light source 34. Luminescence intensity characteristics are the characteristics of what wavelength of light is emitted with what intensity when a voltage is applied to a solid light source and excitation light is incident on 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 FIG. 4, symbol V indicates violet light, symbol R indicates red light, symbol G indicates green light, and symbol B indicates blue light.

  First, configurations of the illumination device 100 and the projector 1000 according to the first embodiment will be described.

  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 first solid light source device 10, a collimating optical system 20, a second solid light source device 30, a condenser lens 40, a dichroic prism 50, an auxiliary prism 60, a first lens array 120, A second lens array 130 and a superimposing lens 150 are provided.

  As shown in FIG. 2A, the first solid-state light source device 10 is a light-emitting diode having a base 12, a first solid-state light source 14, a fluorescent layer 16, and a sealing member 18, and includes red light, green light, and blue light. It is a Lambert light emission type white solid light source that emits white light including light (see FIGS. 4B to 4D described later). The first solid-state light source device 10 has lead wires and the like in addition to the above-described components, but illustration and description thereof are omitted.

The base 12 is a base on which the first solid light source 14 is mounted.
The first solid-state light source 14 emits violet light (emission intensity peak: about 400 nm, see FIG. 4A) as main excitation light. The first solid-state light source 14 is mainly composed of gallium nitride and has a pn junction type structure. The first solid-state light source may not have a pn junction type structure, and may have a double heterojunction type, a quantum well junction type, or the like.
A reflective layer (not shown) is formed between the first solid light source 14 and the base 12, and the violet light emitted from the first solid light source to the base 12 side is converted into a fluorescent layer by the reflective layer. Reflected to the 16 side.

The fluorescent layer 16 includes a red phosphor that absorbs purple light and emits red light, a green phosphor that absorbs purple light and emits green light, and blue fluorescence that absorbs purple light and emits blue light. The first solid light source 14 is disposed on the illuminated region side. The red phosphor is made of, for example, CaAlSiN ₃ —Si ₂ N ₂ O: Eu. The green phosphor is made of, for example, Ba ₃ Si ₆ O ₁₂ N ₂ : Eu. The blue phosphor is made of, for example, BaMgAl ₁₀ O ₁₇ : Eu. The phosphors are not limited to those described above, and other phosphors can be used as long as each color light is emitted by main excitation light and auxiliary excitation light (described later).

The fluorescent layer 16 emits violet light emitted from the first solid-state light source 14 and the second solid-state light source device 30 (described later), red light (emission intensity peak: about 640 nm) and green light (emission intensity peak: The light is converted into blue light (peak of emission intensity: about 460 nm) and emitted (see FIGS. 4B to 4D).
The sealing member 18 is made of a transparent epoxy resin and protects the first solid light source 14 and the fluorescent layer 16.

As shown in FIG. 1, the collimating optical system 20 includes a first lens 22 that suppresses the spread of light from the first solid-state light source device 10 and a second lens 24 that substantially parallelizes the light from the first lens 22. And has a function of making the light from the first solid-state light source device 10 substantially parallel as a whole.
The first lens 22 is a plano-convex lens having a flat entrance surface and a spherical exit surface.
In the second lens 24, a front aspheric surface is formed on the incident surface, and a rear aspheric surface is formed on the exit surface. The pre-stage aspherical surface represents the light flux density distribution of the light emitted from the first solid-state light source device 10, and the light flux density in the periphery where the light flux density in the vicinity of the optical axis of the collimating optical system 20 is away from the optical axis of the collimating optical system 20. It has a function of converting to a predetermined light flux density distribution that becomes higher than the above. The latter aspherical surface has a function of making the light formed in a predetermined light flux density distribution substantially parallel.
In the light emitted from the collimating optical system 20, the light flux density in the vicinity of the optical axis of the collimating optical system 20 is higher than the light flux density in the peripheral portion away from the optical axis of the collimating optical system 20.

  As shown in FIG. 2B, the second solid light source device 30 is a light emitting diode having a base 32, a second solid light source 34, and a sealing member 38, and emits violet light (FIG. 4 (described later)). See e). As shown in FIG. 4D, the second solid light source 34 emits violet light (peak of emission intensity: about 400 nm) as color light. The base 32 has the same configuration as the base 12, the second solid light source 34 has the same configuration as the first solid light source 14, and the sealing member 38 has the same configuration as the sealing member 18.

As shown in FIG. 1, the condensing lens 40 is a condensing optical system that condenses the sub-excitation light from the second solid-state light source device 30. Although the detailed description by illustration is omitted, the condenser lens 40 is an aspherical lens. The secondary excitation light is collected by the condenser lens 40 and the first lens 22 so as to enter the fluorescent layer 26.
The condensing optical system may be composed of a plurality of lenses.

As shown in FIGS. 1 and 3, the dichroic prism 50 is disposed between the first lens 22 and the second lens 24, and emits sub-excitation light (purple light) emitted from the condenser lens 40. And a dichroic optical element having a dichroic surface 52 that transmits fluorescence (red light, green light, and blue light). Specifically, the dichroic surface 52 reflects light having a wavelength of 440 nm or less and allows light having a wavelength to exceed 440 nm to pass. In FIG. 3, reference numeral 10 ax indicates the optical axis of the first solid state light source device 10, and reference numeral 30 ax indicates the optical axis of the second solid state light source device 30.
The dichroic prism 50 is composed of a composite prism composed of prism pieces 54 and 56, and a joint surface between the prism piece 54 and the prism piece 56 is a dichroic surface 52.
As shown in FIG. 3, the dichroic prism 50 includes a dichroic surface 52 and an optical axis of the first solid light source device 10 on a plane including the optical axis of the first solid light source device 10 and the optical axis of the second solid light source device 30. Is arranged such that the angle α formed by is 50 °.

The dichroic surface 52 is made of a dielectric multilayer film, and the dielectric multilayer film has a film configuration that gradually changes according to the incident angle of the secondary excitation light incident on the dichroic surface 52 (so-called diffusion dichroic coating). The sub-excitation light incident on any region of the dichroic surface 52 has substantially the same wavelength / transmittance characteristics.
Further, as shown in FIG. 1, the secondary excitation light from the second solid-state light source device 30 enters the dichroic surface 52 while being focused by the condenser lens 40, and is reflected toward the fluorescent layer 16 by the dichroic surface 52. The

  An auxiliary prism 60 having an incident surface perpendicular to the optical axis of the second solid light source device 30 is joined to the second solid light source device 30 side of the dichroic prism 50.

  The first lens array 120 has a plurality of first small lenses 122 for dividing the light from the collimator optical system 20 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 collimator optical system 20 into a plurality of partial light beams, and the plurality of first small lenses 122 are optical axes of the first solid-state light source device 10. Are arranged in a matrix of a plurality of rows and a plurality of columns in a plane orthogonal to the. Although not illustrated, the outer shape of the first small lens 122 is similar to the outer shape of the image forming area of the liquid crystal 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 area of the liquid crystal devices 400R, 400G, and 400B together with the superimposing lens 150. The second lens array 130 has substantially the same configuration as the first lens array 120, and a plurality of second small lenses 132 are arranged in a plurality of rows and columns in a plane orthogonal to the optical axis of the first solid-state light source device 10. It has a configuration arranged in a matrix.

The superimposing lens 150 superimposes each partial light beam from the second lens array 130 in the illuminated area. The superimposing lens 150 is an optical element that condenses a plurality of partial light beams that have passed through the first lens array 120 and the second lens array 130 and superimposes them in the vicinity of the image forming regions of the liquid crystal devices 400R, 400G, and 400B. 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 first lens array 120, the second lens array 130, and the superimposing lens 150 constitute a light homogenizing optical system that equalizes the in-plane intensity distribution of light incident on the light modulation device as a lens integrator optical system.
Note that a rod integrator optical system including a plurality of condensing lenses and a rod lens 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 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 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 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 illumination device 100 and the projector 1000 according to the first embodiment will be described.

  According to the illuminating device 100 according to the first embodiment, as the light source for exciting the fluorescent layer 16, two light sources, the first solid-state light source 14 that emits main excitation light and the second solid-state light source 34 that emits sub-excitation light. Therefore, it is possible to reduce the thermal load applied to the light source as compared with the case of an illuminating device that uses one light source as a light source for exciting the fluorescent layer. As a result, the life of the light source is shortened. It is possible to increase the brightness of the lighting device without any problem.

  Moreover, according to the illuminating device 100 which concerns on Embodiment 1, since it is comprised so that two excitation light of main excitation light and subexcitation light may be converted into fluorescence using the single fluorescence layer 16, one Compared with an illuminating device configured to convert excitation light into fluorescence using a single fluorescent layer, the emission area is not particularly large, and therefore the illumination luminous flux is caused by the increase in the emission area. The quality of the product will not deteriorate.

  Moreover, according to the illuminating device 100 which concerns on Embodiment 1, since it is (alpha) = 50 degrees and satisfy | fills the relationship of "45 degrees <(alpha) <60 degrees", the 1st solid state light source device 10 and the 2nd solid state light source device 30 The lighting device 100 can be downsized without interfering with each other.

  Moreover, according to the illuminating device 100 which concerns on Embodiment 1, the 1st solid-state light source device 10 inject | emits the white light containing red light, green light, and blue light, and is a white solid light source of a Lambert light emission type, Main excitation light In addition, the secondary excitation light is violet light, and the dichroic surface 52 reflects light having a wavelength of 440 nm or less and passes light having a wavelength exceeding 440 nm. Therefore, white light is emitted from the lighting device 100 with a relatively simple configuration. Is possible.

  Moreover, according to the illuminating device 100 which concerns on Embodiment 1, since a dichroic optical element consists of the dichroic prism 50, it becomes possible to reduce the reflection loss in a dichroic optical element.

  Further, according to the illumination device 100 according to the first embodiment, the auxiliary prism 60 having an incident surface perpendicular to the optical axis of the second solid light source device 30 is provided on the second solid light source device 30 side of the dichroic prism 50. Therefore, the secondary excitation light can be correctly incident on the dichroic prism 50.

  Further, according to the illumination device 100 according to the first embodiment, the auxiliary prism 60 is bonded to the second solid-state light source device 30 side of the dichroic prism 50, so that it occurs between the dichroic prism 50 and the auxiliary prism 60. It is possible to reduce reflection loss that may occur.

  Further, according to the illumination device 100 according to the first embodiment, the dichroic surface 52 is formed of a dielectric multilayer film, and the dielectric multilayer film is a film that gradually changes according to the incident angle of the sub-excitation light incident on the dichroic surface 52. Because it has the same structure and has substantially the same wavelength and transmittance characteristics with respect to the secondary excitation light incident on any region of the dichroic surface 52, the secondary excitation light is reflected with high reflectance in any region of the dichroic surface 52. It becomes possible to do.

  Further, according to the illumination device 100 according to the first embodiment, the magnitude relationship of the incident angle of the sub-excitation light with respect to the dichroic surface 52 exhibits the same tendency as the magnitude relationship of the incident angle of the fluorescence with respect to the dichroic surface 52. Since the multilayer film has substantially the same wavelength / transmittance characteristics with respect to fluorescence incident on any region of the dichroic surface 52, the multilayer film transmits fluorescence with high transmittance in any region of the dichroic surface 52. Is possible.

  Further, according to the illumination device 100 according to the first embodiment, the light flux density in the vicinity of the optical axis of the collimating optical system 20 in the light emitted from the collimating optical system 20 is a peripheral part away from the optical axis of the collimating optical system 20. Therefore, it is possible to increase the proportion of the light irradiated to the illuminated area with a small angle, and to irradiate with the large angle of the light irradiated to the illuminated area. The light utilization efficiency does not decrease due to the increase in the ratio of light to be emitted.

  In the illumination device 100 according to the first embodiment, the front aspheric surface is formed on the incident surface of the second lens 24 and the rear aspheric surface is formed on the exit surface of the second lens 24. The collimating optical system 20 having the above-described effects can be configured with a single lens.

  The projector 1000 according to the first embodiment includes the lighting device 100 that can increase the brightness without shortening the lifetime of the solid-state light source. Therefore, the projector 1000 is a high-brightness projector that is less frequently replaced.

  Further, according to the projector 1000 according to the first embodiment, since the illumination device 100 that can be miniaturized without causing the first solid-state light source device 10 and the second solid-state light source device 30 to interfere with each other is provided, the projector can be easily operated. It becomes possible to reduce the size.

[Embodiment 2]
FIG. 5 is a plan view showing an optical system of the projector 1002 according to the second embodiment.
FIG. 6 is a diagram for explaining the first solid-state light source device 11, the second solid-state light source device 31, and the third solid-state light source device 70 in the second embodiment. 6A is a cross-sectional view of the first solid-state light source device 11, FIG. 6B is a cross-sectional view of the second solid-state light source device 31, and FIG. 6C is a cross-sectional view of the third solid-state light source device 70. FIG.
FIG. 7 is a graph showing the emission intensity characteristics of the first solid light source 25, the emission intensity characteristics of the phosphor, the emission intensity characteristics of the second solid light source 35, and the emission intensity characteristics of the third solid light source 74 in the second embodiment. FIG. 7A is a graph showing the emission intensity characteristic of the first solid-state light source 15, and FIG. 7B is a graph showing the emission intensity characteristic of the phosphor contained in the fluorescent layer 27. FIG. Is a graph showing the emission intensity characteristic of the second solid-state light source device 35, and FIG. 7D is a graph showing the emission intensity characteristic of the third solid-state light source device 74.
In FIG. 7, symbol R indicates red light, symbol G indicates green light, and symbol B indicates blue light.

  The illumination device 102 according to the second embodiment has basically the same configuration as the illumination device 100 according to the first embodiment, but includes a third solid-state light source device that emits blue light, a condensing lens, and a second auxiliary prism. Furthermore, the point provided is different from the case of the illuminating device 100 which concerns on Embodiment 1. FIG. Accordingly, the configurations of the first solid-state light source device, the second solid-state light source device, and the dichroic optical element are also different from those of the illumination device 100 according to the first embodiment.

  As shown in FIG. 6A, the first solid-state light source device 11 has basically the same configuration as the first solid-state light source device 10 in the first embodiment, but the first solid-state light source 15 and the fluorescent layer 17 are the same. The configuration is different from that of the first solid-state light source device 10 in the first embodiment. As a result, the first solid-state light source device 11 emits fluorescence including red light and green light (see FIG. 7B described later), and becomes a Lambert light emission type solid-state light source.

The first solid-state light source 15 emits blue light (emission intensity peak: about 460 nm, see FIG. 7A) as main excitation light.
The fluorescent layer 17 is formed of 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 another fluorescent material (a YAG fluorescent material other than the above, a silicate fluorescent material, a TAG fluorescent material, etc.). 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. In short, the fluorescent layer may be configured to emit fluorescence including red light and green light as fluorescence.
The fluorescent layer 17 converts blue light emitted from the first solid light source 15 and the second solid light source 35 (described later) into red light (emission intensity peak: about 610 nm) and green light (emission intensity peak: about 550 nm). Then, it is converted into fluorescence including the emission (see FIG. 7B) and emitted.

  As shown in FIG. 6B, the second solid light source device 31 basically has the same configuration as the second solid light source device 30 in the first embodiment, but the configuration of the second solid light source 35 is the embodiment. 1 is different from the second solid-state light source device 30 in FIG. As shown in FIG. 7C, the second solid light source 35 emits blue light (emission intensity peak: about 460 nm) as auxiliary excitation light.

  As shown in FIG. 6C, the third solid light source device 70 is a light emitting diode having a base 72, a third solid light source 74 and a sealing member 78, and has the same configuration as the second solid light source device 31. Have. As shown in FIG. 7D, the third solid light source 74 emits blue light (emission intensity peak: about 460 nm) as color light.

  The condenser lens 80 has the same configuration as the first lens 22 and has a function of suppressing the spread of light from the third solid-state light source device 70. The condenser lens 80 and the second lens 24 as a whole have a function of making the light from the third solid light source device 70 substantially parallel.

  The dichroic prism 58 basically has the same configuration as that of the dichroic prism 50 in the first embodiment, but the configuration of the dichroic surface 53 (not shown) is different from that of the dichroic prism 50 in the first embodiment. The dichroic surface 53 reflects the secondary excitation light (blue light) emitted from the condenser lens 40 toward the fluorescent layer 17 and allows the fluorescence (red light and green light) to pass therethrough. The dichroic surface 53 reflects the blue light from the third solid light source device 70 toward the second lens 24. Specifically, the dichroic surface 53 reflects light having a wavelength of 500 nm or less, and allows light having a wavelength to exceed 500 nm to pass therethrough.

  A second auxiliary prism 62 having an incident surface perpendicular to the optical axis of the third solid light source device 70 is joined to the dichroic prism 58 on the third solid light source device 70 side.

  Thus, the illumination device 102 according to the second embodiment is different from the illumination device 100 according to the first embodiment in that the third solid light source device that emits blue light, the condensing lens, and the second auxiliary prism are further provided. In addition, the configurations of the first solid-state light source device, the second solid-state light source device, and the dichroic optical element are different from those of the illumination device 100 according to the first embodiment, but as a light source for exciting the fluorescent layer 17. Since the two light sources, ie, the first solid-state light source 15 that emits the main excitation light and the second solid-state light source 35 that emits the sub-excitation light, are used, the fluorescent layer is formed in the same manner as the illumination device 100 according to the first embodiment. The thermal load applied to the light source can be reduced as compared with the case of the illumination device using one light source as a light source for excitation, and as a result, the illumination device without shortening the life of the light source It becomes possible to high brightness.

  Moreover, according to the illuminating device 102 which concerns on Embodiment 2, since it is comprised so that two excitation light of main excitation light and subexcitation light may be converted into fluorescence using the single fluorescence layer 17, Embodiment Similarly to the illumination device 100 according to 1, the light emission area is not particularly large even when compared with an illumination device configured to convert one excitation light into fluorescence using one fluorescent layer. The quality of the illumination light beam does not deteriorate due to the increase in the light emitting area.

  In addition, according to the lighting device 102 according to the second embodiment, α = 50 °, and satisfies the relationship of “45 ° <α <60 °”, so that the first lighting device 100 according to the first embodiment is similar to the first lighting device 100 according to the first embodiment. The lighting device 102 can be downsized without the solid light source device 11 and the second solid light source device 31 interfering with each other.

  Moreover, according to the illuminating device 102 which concerns on Embodiment 2, it is arrange | positioned so as to oppose the 2nd solid light source device 31 on both sides of the dichroic prism 58, and the 3rd solid light source device which has the 3rd solid light source 74 which inject | emits blue light. 70, and the dichroic surface 53 reflects light having a wavelength of 500 nm or less and allows light having a wavelength to exceed 500 nm to pass therethrough, so that white light with higher luminance can be emitted using three solid-state light sources. It becomes possible.

  Note that the illumination device 102 according to the second embodiment further includes a condenser lens and a second auxiliary prism, and the configuration of the first solid light source device, the second solid light source device, and the dichroic optical element is the illumination according to the first embodiment. Since it has the same configuration as that of the lighting device 100 according to the first embodiment in points other than the two points different from the device 100, the corresponding effect among the effects of the lighting device 100 according to the first embodiment is maintained as it is. Have.

  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 the first embodiment, the main excitation light is violet light, but the present invention is not limited to this. For example, the main excitation light may be ultraviolet light or blue light. In the first embodiment, the sub-excitation light is violet light, but the present invention is not limited to this. For example, the auxiliary excitation light may be ultraviolet light.

(2) In the second embodiment, the main excitation light is blue light, but the present invention is not limited to this. For example, the main excitation light may be ultraviolet light or violet light. In the second embodiment, the sub-excitation light is blue light, but the present invention is not limited to this. For example, the auxiliary excitation light may be ultraviolet light or violet light.

(3) In each of the above embodiments, a transmissive projector is used, but 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.

(4) In each of the above embodiments, 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.

(5) In each of the above embodiments, a light emitting diode is used as each solid state light source device, but the present invention is not limited to this. For example, a semiconductor laser may be used as each solid light source device, or an organic light emitting diode may be used.

(6) In each of the above embodiments, the second solid-state light source device has one second solid-state light source, but the present invention is not limited to this. FIG. 8 is a plan view showing an optical system of the projector 1004 according to the first modification. As illustrated in FIG. 8, the illumination device 104 according to the first modification includes a second solid light source 92 that emits sub-excitation light including s-polarized light and a second solid light source 94 that outputs sub-excitation light including p-polarized light. The second solid-state light source device 90 includes condensing lenses 42 and 44 that condense the respective sub-excitation light, and a polarization selection prism 110 that transmits s-polarized light and reflects p-polarized light. The second solid-state light sources 92 and 94 are made of laser diodes, although detailed explanation thereof is omitted. As for the illuminating device of this invention, the 2nd solid-state light source device may have two 2nd solid-state light sources like the illuminating device 1 which concerns on the modification 1. As shown in FIG. In addition, according to the structure of the illuminating device 104 which concerns on the modification 1, it becomes possible to make more subexcitation light inject into a fluorescent layer.

(7) In each of the above embodiments, the lighting device includes an auxiliary prism, but the present invention is not limited to this. FIG. 9 is a plan view showing an optical system of a projector 1006 according to the second modification. In the illuminating device 106 according to Modification 2, as shown in FIG. 9, the dichroic prism 59 has a portion on the second solid light source device 30 side that is perpendicular to the optical axis of the second solid light source device 30. Has a shape. The illuminating device of the present invention does not need to have an auxiliary prism like the illuminating device 106 according to the second modification. Even with the configuration of the illumination device 106 according to the second modification, it is possible to correctly make the sub-excitation light incident on the dichroic prism.

(8) In each of the above embodiments, the illumination device includes a dichroic prism having a dichroic surface, but the present invention is not limited to this. The lighting device may include a dichroic mirror having a dichroic surface.

(9) In each of the above embodiments, a polarization conversion device may be further provided between the second lens array 130 and the superimposing lens 150. The polarization conversion device is a polarization conversion element that converts light including both one polarization component and the other polarization component into substantially one type of linearly polarized light having a uniform polarization direction.

(10) In each of the above embodiments, the first lens 22 is a plano-convex lens having a flat entrance surface and a spherical exit surface, and the second lens 24 has a front aspheric surface formed on the entrance surface. Although the latter aspherical surface is formed, the present invention is not limited to this. For example, a front aspheric surface may be formed on the exit surface of the first lens. In addition, the shapes of the first lens and the second lens are not limited to the shapes described in the above embodiments. In short, the collimating optical system including the first lens and the second lens is a first solid-state light source. Any shape that has a function of collimating light emitted from the apparatus may be used.

(11) In each of the above embodiments, a projector using three liquid crystal light modulation devices has been described as an example, but 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.

(12) 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.

(13) In each of the above embodiments, the example in which the illumination 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 illumination device of the present invention can be applied to other optical devices (for example, an optical disc device, a headlamp of an automobile, etc.).

DESCRIPTION OF SYMBOLS 10,11 ... 1st solid state light source device, 12, 13, 32, 33, 72 ... Base, 14, 15 ... 1st solid state light source, 16, 17 ... Fluorescent layer, 18, 19, 38, 39, 78 ... Sealing Stop member, 20 ... collimating optical system, 22 ... first lens, 24 ... second lens, 30, 31, 90 ... second solid light source device, 34, 35, 92, 94 ... second solid light source, 40, 42, 44, 80, 300R, 300G, 300B ... condensing lens, 50, 58, 59 ... dichroic prism, 52 ... dichroic surface, 54, 56 ... prism piece, 60 ... auxiliary prism, 62 ... second auxiliary prism, 70 ... first Three solid-state light source devices, 74 ... third solid-state light source, 100, 102, 104, 106 ... illumination device, 110 ... polarization selection prism, 120 ... first lens array, 122 ... first small lens, 130 ... second lens array 132, second small lens, 150, superimposing lens, 200, color separation light guide optical system, 210, 220, dichroic mirror, 230, 240, 250, reflecting mirror, 260, 270, relay lens, 400R, 400G, 400B ... Liquid crystal light modulator, 500 ... Cross dichroic prism, 600 ... Projection optical system, 1000, 1002, 1004, 1006 ... Projector, SCR ... Screen

Claims (10)

A first solid-state light source device having a first solid-state light source that emits main excitation light; and a fluorescent layer that converts at least a portion of the main excitation light into fluorescence and emits the fluorescence;
A first lens that suppresses the spread of light from the first solid-state light source device; and a second lens that substantially collimates the light from the first lens, and is emitted from the first solid-state light source device as a whole. An illumination device including a collimating optical system for collimating light substantially,
A second solid-state light source device having a second solid-state light source that emits sub-excitation light;
A condensing optical system for condensing the sub-excitation light from the second solid-state light source device;
Dichroic optics that is disposed between the first lens and the second lens and has a dichroic surface that reflects the secondary excitation light emitted from the condensing optical system toward the fluorescent layer and allows the fluorescence to pass therethrough. And further comprising an element,
The fluorescent layer is configured to convert the secondary excitation light into the fluorescence and emit the fluorescence,
In a plane including the optical axis of the first solid-state light source device and the optical axis of the second solid-state light source device, an angle α formed by the dichroic surface and the optical axis of the first solid-state light source device is “45 ° <α <60. A lighting device characterized by satisfying the relationship of “°”. The lighting device according to claim 1.
The first solid-state light source device emits white light including red light, green light, and blue light, and is a Lambert light emission type white solid light source.
The main excitation light is ultraviolet light, violet light or blue light,
The auxiliary excitation light is ultraviolet light or violet light,
The dichroic surface reflects light having a wavelength of 440 nm or less and transmits light having a wavelength exceeding 440 nm. The lighting device according to claim 1.
A third solid-state light source device having a third solid-state light source arranged to face the second solid-state light source device across the dichroic optical element and emitting blue light;
The main excitation light is ultraviolet light, violet light or blue light,
The auxiliary excitation light is ultraviolet light, violet light or blue light,
The fluorescent layer is configured to emit fluorescence including red light and green light as fluorescence,
The dichroic surface reflects light having a wavelength of 500 nm or less, and allows light having a wavelength to exceed 500 nm to pass therethrough. In the illuminating device in any one of Claims 1-3,
The dichroic optical element comprises a dichroic prism. The lighting device according to claim 4.
An illuminating device, wherein an auxiliary prism having an incident surface perpendicular to the optical axis of the second solid state light source device is arranged on the second solid state light source device side of the dichroic prism. The lighting device according to claim 5.
The illuminating device, wherein the auxiliary prism is joined to the dichroic prism on the second solid-state light source device side. The lighting device according to claim 4.
The dichroic prism has a shape in which a portion on the second solid-state light source device side is a surface perpendicular to the optical axis of the second solid-state light source device. In the illuminating device in any one of Claims 1-7,
The dichroic surface is made of a dielectric multilayer film,
The dielectric multilayer film has a film configuration that gradually changes according to the incident angle of the secondary excitation light incident on the dichroic surface, and is substantially the same for the secondary excitation light incident on any region of the dichroic surface. An illumination device characterized by having a wavelength / transmittance characteristic of: In the illuminating device in any one of Claims 1-8,
A front aspheric surface is formed on the exit surface of the first lens or the entrance surface of the second lens, and a rear aspheric surface is formed on the exit surface of the second lens;
The pre-stage aspheric surface indicates a light flux density distribution of light emitted from the first solid-state light source device, and a light flux density in a peripheral portion where the light flux density in the vicinity of the optical axis of the collimating optical system is away from the optical axis of the collimating optical system. Has a function of converting to a predetermined light flux density distribution that is higher than
The latter aspherical surface has a function of substantially collimating the light formed in the predetermined light flux density distribution,
The illumination apparatus according to claim 1, wherein a light flux density in the vicinity of an optical axis of the collimating optical system in light emitted from the collimating optical system is higher than a light flux density in a peripheral portion away from the optical axis of the collimating optical system. The lighting device according to any one of claims 1 to 9,
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.

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