JP2011164449A - Light source device and projector - Google Patents

Abstract

A light source device capable of emitting light in a desired direction is provided.
A light source device according to the present invention includes a light emitting element that emits first light, a fluorescent light emitting unit that emits second light when excited by the first light, and a first light. And the fluorescent mirror 40 is disposed on the rotation axis R of the mirror surface 12 so as to be separated from the concave mirror 10 and the concave mirror 10 having the mirror surface 12 that reflects the second light L2.
[Selection] Figure 1

Description

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

  As a light source device for a light source such as a projector or an illumination device, a light source device using a light emitting element such as a light emitting diode or a semiconductor laser is expected. For example, Patent Document 1 discloses a technique in which light emitted from a light emitting diode is irradiated onto phosphor particles in the light guide plate and light having a predetermined wavelength is emitted in a structure in which the light emitting diode is disposed on the side surface of the light guide plate. ing.

  However, in the technique described in Patent Document 1, the wavelength light from the phosphor particles diverges, and the light utilization efficiency may be reduced.

JP 2009-16289 A

  One of the objects according to some aspects of the present invention is to provide a light source device capable of emitting light in a desired direction. Another object of some aspects of the present invention is to provide a projector having the light source device.

The light source device according to the present invention includes:
A light emitting element that emits first light;
A fluorescent light emitting part that emits second light when excited by the first light;
A concave mirror having a mirror surface for reflecting the second light;
Including
The fluorescent light emitting unit is disposed apart from the concave mirror and on the rotation axis of the mirror surface.

  According to such a light source device, the second light can be emitted in a desired direction.

In the light source device according to the present invention,
The shape of the mirror surface is a paraboloid,
The fluorescent light emitting unit may be disposed including the focal point of the mirror surface.

  According to such a light source device, the second light reflected on the mirror surface becomes parallel light and can be emitted toward the outside.

In the light source device according to the present invention,
The shape of the mirror surface is an elliptical surface,
The fluorescent light emitting unit may be disposed including the focal point of the mirror surface.

  According to such a light source device, the second light reflected by the mirror surface becomes focused light and can be emitted to the outside.

In the light source device according to the present invention,
The light emitting element may be disposed on a surface opposite to the mirror surface of the concave mirror.

  According to such a light source device, it is possible to prevent the second light from being blocked by the light emitting element.

In the light source device according to the present invention,
A support portion provided on the mirror surface and supporting the fluorescent light emitting portion;
The support part may be made of metal.

  According to such a light source device, the heat dissipation of the fluorescent light emitting unit can be improved.

In the light source device according to the present invention,
A plurality of the light emitting elements can be provided.

  According to such a light source device, the output of the light source device can be increased.

In the light source device according to the present invention,
The plurality of light emitting elements may be disposed rotationally symmetrically with respect to the fluorescent light emitting unit in plan view from the mirror surface side.

  According to such a light source device, it is possible to irradiate the fluorescent light emitting unit with good symmetry. Therefore, the second light can have a more uniform light intensity distribution.

The projector according to the present invention is
A light source device according to the present invention;
A light modulation device that modulates light emitted from the light source device according to image information;
A projection device for projecting an image formed by the light modulation device;
including.

  According to such a projector, the light source device can emit light in a desired direction, so that the light use efficiency can be improved.

Sectional drawing which shows typically the light source device which concerns on this embodiment. The top view which shows typically the light source device which concerns on this embodiment. Sectional drawing which shows typically the light source device which concerns on the 1st modification of this embodiment. Sectional drawing which shows typically the light source device which concerns on the 2nd modification of this embodiment. Sectional drawing which shows typically the light source device which concerns on the 3rd modification of this embodiment. Sectional drawing which shows typically the light source device which concerns on the 4th modification of this embodiment. 1 is a diagram schematically showing a projector according to an embodiment.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

1. Light Source Device First, a light source device according to the present embodiment will be described with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing a light source device 100 according to this embodiment. FIG. 2 is a plan view schematically showing the light source device 100 according to the present embodiment. 1 is a cross-sectional view taken along the line II of FIG. In FIG. 2, the second light L2 is not shown for convenience.

  As shown in FIGS. 1 and 2, the light source device 100 can include a concave mirror 10, a light emitting element 20, a support unit 30, and a fluorescent light emitting unit 40.

  The concave mirror 10 has a mirror surface 12. The mirror surface 12 is a mirror surface inside the concave mirror 10. The mirror surface 12 is, for example, a surface that can be obtained by rotating a quadratic curve about the rotation axis R. The shape of the mirror surface 12 is, for example, a paraboloid (rotary paraboloid). Examples of the material of the mirror surface 12 include glass and metal. The mirror surface 12 can reflect the second light L <b> 2 emitted from the fluorescent light emitting unit 40. The mirror surface 12 may be a dichroic mirror that transmits the first light L1 emitted from the light emitting element 20 and reflects the second light L2 emitted from the fluorescent light emitting unit 40.

  The light emitting element 20 emits the first light L1. The first light L1 is transmitted through an entrance (hole) (not shown) of the concave mirror 10 or when the mirror surface 12 is a dichroic mirror, and irradiates the fluorescent light emitting unit 40. The fluorescent light emitting unit 40 emits the second light L2 when excited by the first light L1. That is, the first light L1 can be said to be excitation light for exciting the fluorescent light emitting unit 40, and the second light L2 can be said to be fluorescent light emitted by the excitation light. The first light L1 is, for example, short-wavelength light such as blue light or near ultraviolet light with good wavelength conversion efficiency. For example, a semiconductor laser can be used as the light emitting element 20. Since the semiconductor laser has a small irradiation area compared to other solid-state light sources, the fluorescent light emitting unit 40 can be irradiated, for example, at a pinpoint. Therefore, the light use efficiency can be improved. The light emitting element 20 is not limited to a semiconductor laser, and for example, a light emitting diode (LED) may be used.

  The light emitting element 20 is provided on the surface 14 side opposite to the mirror surface 12 of the concave mirror 10, that is, on the outer side of the concave mirror 10. Thereby, in the light source device 100, the second light L <b> 2 emitted from the fluorescent light emitting unit 40 can be prevented from being blocked by the light emitting element 20. In the example of FIG. 2, eight light emitting elements 20 are provided, but the number is not particularly limited. In the example shown in FIG. 2, the plurality of light emitting elements 20 are arranged rotationally symmetrically with respect to the fluorescent light emitting unit 40 in plan view from the mirror surface 12 side of the concave mirror 10. That is, the plurality of light emitting elements 20 are arranged at equal intervals so as to surround the concave mirror 10 when viewed from the mirror surface 12 side of the concave mirror 10. Thereby, the fluorescence light emission part 40 can be irradiated with sufficient symmetry. Therefore, the second light L2 emitted from the fluorescent light emitting unit 40 can have a more uniform light intensity distribution as compared with the case where the plurality of light emitting elements are not arranged symmetrically.

  It is desirable that the optical axes of the first light L1 emitted from the plurality of light emitting elements 20 intersect at the center of the fluorescent light emitting unit 40. Thereby, the fluorescence light emission part 40 can be irradiated efficiently. In the example shown in FIG. 1, the optical axis of the first light L1 emitted from one light emitting element 20 and the optical axis of the second light L1 emitted from the other light emitting element 20 are in a straight line. The light emitting element 20 may be supported by a support portion (not shown).

  The support part 30 is provided on the mirror surface 12. The support unit 30 can support the fluorescent light emitting unit 40. The support portion 30 has, for example, a rod shape, and the fluorescent light emitting portion 40 can be installed at the tip thereof. In the example shown in FIG. 1, the support portion 30 is provided on the rotation axis R of the mirror surface 12. The material of the support portion 30 is, for example, a metal, and more specifically, Al, Cu, Ag, or the like. Thereby, the heat dissipation of the fluorescence light emission part 40 can be improved.

  The fluorescent light emitting unit 40 emits light when excited by the first light L1. The second light L2 obtained by exciting the fluorescent light emitting unit 40 is reflected by the mirror surface 12, and illuminates the outside as illumination light. The fluorescent light emitting unit 40 is made of, for example, a phosphor that is excited by the first light L1 and emits light, and a resin or glass for dispersing the phosphor.

  The fluorescent light emitting unit 40 is provided on the mirror surface 12 side of the concave mirror 10 so as to be separated from the concave mirror 10. In the example illustrated in FIG. 1, the fluorescent light emitting unit 40 is provided by being separated from the concave mirror 10 by being supported by the support unit 30. The fluorescent light emitting unit 40 is disposed on the rotation axis R of the mirror surface 12. In the example illustrated in FIG. 1, the fluorescent light emitting unit 40 is disposed including the focal point F of the mirror surface 12 having a parabolic shape. Thereby, the 2nd light L2 reflected in the mirror surface 12 turns into parallel light, and can be radiate | emitted toward the exterior (toward opening of the concave mirror 10). The shape of the fluorescent light emitting unit 40 is, for example, a sphere. In this case, the center of the fluorescent light emitting unit 40 and the focal point F may coincide with each other. Thereby, parallel light can be obtained efficiently.

  The color of the second light L2 that is fluorescent light is determined by a combination of the color (wavelength) of the first light L1 that excites the phosphor and the composition of the phosphor. That is, the color of the fluorescent light can be controlled by changing the type of the phosphor according to the color (wavelength) of the first light L1. The following can be mentioned as an example of a composition of fluorescent substance.

When the first light L1 is blue, examples of the phosphor composition in which the second light L2 is red include (Ca, Sr) ₂ Si ₅ N ₈ : Eu, (Ca, Sr) AlSiN ₃ : Eu , CaSiN ₂ : Eu. When the first light L1 is blue, examples of the phosphor composition in which the second light L2 is green include ZnS: Cu, Al, SrGa ₂ S ₄ : Eu, (Ba, Sr) ₂ SiO ₄ : Eu, SrAl ₂ O ₄ : Eu, (Si, Al) ₆ (O, N) ₈ : Eu can be mentioned. Examples of the phosphor composition in which the first light L1 is blue and the second light L2 is yellow include Y ₃ Al ₅ O ₁₂ : Ce (YAG series), CaGa ₂ S ₄ : Eu, and SrSiO _4. : Eu can be mentioned.

When the first light L1 is near-ultraviolet light, examples of the phosphor composition in which the second light L2 is red are Y ₂ O ₂ S: Eu, 3.5MgO · 0.5MgF ₂ · GeO ₂ : Mn can be mentioned. When the first light L1 is near-ultraviolet light, examples of the phosphor composition in which the second light L2 is blue-green are BaMgAl ₁₀ O ₁₇ : Eu, Mn, LaAl (SiAl) ₆ N ₉ O: Ce Can be mentioned. When the first light L1 is near-ultraviolet light, examples of the composition of the phosphor that makes the second light L2 blue are (Ca, Sr) ₅ (PO ₄ ) ₃ Cl: Eu, Sr ₂ P ₂ O ₇ : Eu, BaMgAl ₁₀ O ₁₇ : Eu.

  Alternatively, the phosphors having the above-described composition may be mixed to form the fluorescent light emitting unit 40, whereby a plurality of colors of fluorescent light may be emitted to obtain light of a desired color. For example, when the first light L1 is near-ultraviolet light, a fluorescent material in which the fluorescent light is red, a fluorescent material in which the fluorescent light is blue, and a fluorescent material in which the fluorescent light is green are mixed at a predetermined ratio to obtain fluorescence. By forming the light emitting unit 40, white light can be obtained.

  The light source device 100 can be applied to a light source such as a display, a lighting device, and a projector described later.

  The light source device 100 according to the present embodiment has the following features, for example.

  According to the light source device 100, as described above, the second light L2 emitted from the fluorescent light emitting unit 40 is reflected on the mirror surface 12 of the concave mirror 10 and emitted toward the outside (toward the opening of the concave mirror 10). Can do. That is, in the light source device 100, the second light L <b> 2 can be emitted in a desired direction by the mirror surface 12.

  According to the light source device 100, the fluorescent light emitting unit 40 can be disposed including the focal point F of the mirror surface 12 having a parabolic shape. Thereby, the 2nd light L2 reflected in the mirror surface 12 turns into parallel light, and can be radiate | emitted toward the exterior.

  According to the light source device 100, the light emitting element 20 can be disposed on the surface 14 side opposite to the mirror surface 12 of the concave mirror 10. Thereby, it is possible to prevent the second light L2 emitted from the fluorescent light emitting unit 40 from being blocked by the light emitting element 20.

  According to the light source device 100, the fluorescent light emitting unit 40 can be supported by the support unit 30 which is a metal material. Therefore, the heat dissipation of the fluorescent light emitting unit 40 can be improved.

  According to the light source device 100, a plurality of light emitting elements 20 can be provided. Therefore, the output of the light source device 100 can be increased.

  According to the light source device 100, the plurality of light emitting elements 20 can be arranged rotationally symmetrically with respect to the fluorescent light emitting unit 40 in plan view from the mirror surface 12 side. Thereby, the fluorescence light emission part 40 can be irradiated with sufficient symmetry. Therefore, the second light L2 emitted from the fluorescent light emitting unit 40 can have a more uniform light intensity distribution as compared with the case where the plurality of light emitting elements are not arranged symmetrically.

2. 2. Modification of light source device 2.1. Next, a light source device according to a first modification of the present embodiment will be described with reference to the drawings. FIG. 3 is a cross-sectional view schematically showing a light source device 200 according to a first modification of the present embodiment. Hereinafter, in the light source device 200 according to the first modified example of the present embodiment, members having the same functions as the constituent members of the light source device 100 according to the present embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. To do.

  In the example of the light source device 100, as shown in FIG. 1, the shape of the mirror surface 12 is a paraboloid (rotary paraboloid), and the second light L2 is reflected by the mirror surface 12 to become parallel light, It was emitted toward.

  On the other hand, in the light source device 200, as shown in FIG. 3, the shape of the mirror surface 12 is an ellipsoid (spheroid). As a result, the second light L2 is reflected by the mirror surface 12 to become focused light, and can be emitted to the outside.

2.2. Next, a light source device according to a second modification of the present embodiment will be described with reference to the drawings. FIG. 4 is a cross-sectional view schematically showing a light source device 300 according to a second modification of the present embodiment. Hereinafter, in the light source device 300 according to the second modified example of the present embodiment, members having the same functions as the constituent members of the light source device 100 according to the present embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. To do.

  In the light source device 300, as shown in FIG. 4, compared with the example of the light source device 100, the optical axis of the first light L1 of the light emitting element 20 is brought closer to the support portion 30, and the first light L1 is directed to the surface 14 The concave mirror 10 is made incident through an incident port (not shown) from a surface opposite to the mirror surface 12. Thereby, in the light source device 300, since the 1st light L1 can be concentrated and irradiated to the support part 30 side of the fluorescence light emission part 40, compared with the example of the light source device 100, the 2nd light L2 more mirror surface 12 more. The amount of parallel light beams toward the opening of the concave mirror 10 can be increased.

2.3. Light Source Device According to Third Modification Next, a light source device according to a third modification of the present embodiment will be described with reference to the drawings. FIG. 5 is a cross-sectional view schematically showing a light source device 400 according to a third modification of the present embodiment. Hereinafter, in the light source device 400 according to the third modified example of the present embodiment, members having the same functions as those of the constituent members of the light source device 300 according to the second modified example of the present embodiment are denoted by the same reference numerals. Detailed description is omitted.

  In the example of the light source device 300, as shown in FIG. 4, the fluorescent light emitting unit 40 is supported by the support unit 30 formed on the mirror surface 12.

  In contrast, the light source device 400 includes a transparent plate 50 as shown in FIG. 5, and the support unit 30 is provided on the transparent plate 50 and supports the fluorescent light emitting unit 40. Therefore, according to the light source device 400, it is possible to prevent the second light L2 traveling toward the mirror surface 12 from being blocked by the support unit 30.

  The transparent plate 50 is provided by sealing the opening of the concave mirror 10, for example. The transparent plate 50 can transmit the second light L2. That is, the second light L2 reflected by the mirror surface 12 is transmitted through the transparent plate 50 and emitted to the outside. As a material of the transparent plate 50, for example, glass or the like can be used. The fluorescent light emitting unit 40 is arranged in a space defined by the surface 52 (the surface on which the support unit 30 is provided) on the mirror surface 12 side of the transparent plate 50 and the mirror surface 12.

2.4. Next, a light source device according to a fourth modification of the present embodiment will be described with reference to the drawings. FIG. 6 is a cross-sectional view schematically showing a light source device 500 according to a fourth modification of the present embodiment. Hereinafter, in the light source device 500 according to the fourth modified example of the present embodiment, members having the same functions as those of the constituent members of the light source device 300 according to the second modified example of the present embodiment are denoted by the same reference numerals. Detailed description is omitted.

  The light source device 500 includes a reflection unit 70 as shown in FIG. The reflection unit 70 has a mirror surface 72. Of the first light L1 emitted from the light emitting element 20, when there is light (transmitted light) that is not absorbed by the fluorescent light emitting unit 40 and passes through the fluorescent light emitting unit 40, the mirror surface 72 reflects the transmitted light. be able to. The transmitted light reflected on the mirror surface 72 can irradiate the fluorescent light emitting unit 40 to excite the fluorescent light emitting unit 40. Therefore, in the light source device 500, the light use efficiency of the first light L1 for obtaining the second light L2 can be improved as compared with the example of the light source device 300. The shape of the mirror surface 72 is not particularly limited as long as the light reflected on the mirror surface 72 can irradiate the fluorescent light emitting unit 40. In the illustrated example, the shape of the mirror surface 72 is a concave surface that forms a part of a spherical surface with the central portion of the fluorescent light emitting unit 40 as the center. The mirror surface 72 and a part of the mirror surface 12 are configured to face each other, and have a relationship of sharing the light focal point of the mirror surface 12 and the light focal point of the mirror surface 72. The mirror surface 72 may be a dichroic mirror that transmits the first light L1 emitted from the light emitting element 20 and reflects the second light L2 emitted from the fluorescent light emitting unit 40. The material of the mirror surface 72 may be a metal.

  The reflection part 70 is supported by the support part 80 extended from the fluorescence light emission part 40, for example. The support portion 80 has, for example, a rod shape, and the reflection portion 70 can be installed at the tip thereof. In the illustrated example, the support portion 80 is provided on the rotation axis R of the mirror surface 12. The material of the support part 80 is, for example, glass or metal, and specific examples of the metal include Al, Cu, and Ag. Thereby, the heat dissipation of the fluorescence light emission part 40 can be improved.

3. Next, the projector according to the present embodiment will be described with reference to the drawings. FIG. 7 is a diagram schematically showing the projector 700. In FIG. 7, for convenience, the casing that configures the projector 700 is omitted.

  As shown in FIG. 7, the projector 700 includes a red light source 100R, a green light source 100G, and a blue light source 100B that emit red light, green light, and blue light, respectively. As the red light source 100R, the light source device according to the present invention (in the following example, the light source device 100) including the fluorescent light emitting unit 40 that emits red light (the second light L2 becomes red) can be used. . As the green light source 100G, the light source device 100 including the fluorescent light emitting unit 40 that emits green light (the second light L2 becomes green) can be used. As the blue light source 100B, the light emitting element 20 that emits blue light may be used, or blue light is emitted by the near ultraviolet light (first light L1) emitted from the light emitting element 20 (second light L2). The light source device 100 including the fluorescent light emitting unit 40 may be used.

  The projector 700 includes transmissive liquid crystal light valves (light modulation devices) 704R, 704G, and 704B that modulate light emitted from the light sources 100R, 100G, and 100B in accordance with image information, and liquid crystal light valves 704R, 704G, and 704B. A projection lens (projection device) 708 that magnifies and projects the image formed on the screen (display surface) 710. In addition, the projector 700 can include a cross dichroic prism (color light combining means) 706 that combines the light emitted from the liquid crystal light valves 704R, 704G, and 704B and guides the light to the projection lens 708.

  Further, in order to make the illuminance distribution of the light emitted from the light sources 100R, 100G, and 100B uniform, the projector 700 includes the uniformizing optical systems 702R, 702G, and 702B on the downstream side of the light path from the light sources 100R, 100G, and 100B. The liquid crystal light valves 704R, 704G, and 704B are illuminated with light that has been provided with a uniform illuminance distribution. The uniformizing optical systems 702R, 702G, and 702B are configured by, for example, a hologram 702a and a field lens 702b.

  The three color lights modulated by the liquid crystal light valves 704R, 704G, and 704B are incident on the cross dichroic prism 706. This prism is formed by bonding four right-angle prisms, and a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are arranged in a cross shape on the inner surface thereof. These dielectric multilayer films combine the three color lights to form light representing a color image. The synthesized light is projected onto the screen 710 by the projection lens 706 that is a projection optical system, and an enlarged image is displayed.

  According to the projector 700, as described above, the light source device 100 that can emit light in a desired direction can be provided. Therefore, in the projector 700, the light use efficiency can be improved.

  In the above example, a transmissive liquid crystal light valve is used as the light modulation device. However, a light valve other than liquid crystal may be used, or a reflective light valve may be used. Examples of such a light valve include a reflective liquid crystal light valve and a digital micromirror device. Further, the configuration of the projection optical system is appropriately changed depending on the type of light valve used.

  In addition, embodiment mentioned above and a modification are examples, Comprising: It is not necessarily limited to these. For example, it is possible to appropriately combine each embodiment and each modification.

  Although the embodiments of the present invention have been described in detail as described above, those skilled in the art will readily understand that many modifications are possible without substantially departing from the novel matters and effects of the present invention. Accordingly, all such modifications are intended to be included in the scope of the present invention.

10 concave mirror, 12 concave mirror surface, 14 concave mirror surface, 20 light emitting element,
30 support part, 40 fluorescent light emission part, 50 transparent plate, 52 surface of transparent plate, 70 reflection part,
72 mirror surface of the reflection part, 80 support part, 100-500 light source device,
700 projector, 702 homogenizing optical system, 702a hologram,
702b field lens, 704 liquid crystal light valve,
706 Cross dichroic prism, 708 projection lens, 710 screen

Claims (8)

A light emitting element that emits first light;
A fluorescent light emitting part that emits second light when excited by the first light;
A concave mirror having a mirror surface for reflecting the second light;
Including
The fluorescent light emitting unit is a light source device that is spaced apart from the concave mirror and disposed on a rotation axis of the mirror surface. In claim 1,
The shape of the mirror surface is a paraboloid,
The fluorescent light emitting unit is a light source device arranged including the focal point of the mirror surface. In claim 1,
The shape of the mirror surface is an elliptical surface,
The fluorescent light emitting unit is a light source device arranged including the focal point of the mirror surface. In any one of Claims 1 thru | or 3,
The light emitting element is a light source device that is disposed on a surface opposite to the mirror surface of the concave mirror. In any one of Claims 1 thru | or 4,
A support portion provided on the mirror surface and supporting the fluorescent light emitting portion;
The light source device, wherein the support portion is made of metal. In any one of Claims 1 thru | or 5,
A light source device, wherein a plurality of the light emitting elements are provided. In claim 6,
The light source device, wherein the plurality of light emitting elements are arranged rotationally symmetrically with respect to the fluorescent light emitting unit in plan view from the mirror side. A light source device according to any one of claims 1 to 7,
A light modulation device that modulates light emitted from the light source device according to image information;
A projection device for projecting an image formed by the light modulation device;
Including projector.

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