JP2018004752A - Wavelength conversion device, illumination device, and projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wavelength conversion device capable of suppressing a reduction in wavelength conversion efficiency of light made incident to a wavelength conversion element, and an illumination device and a projector.SOLUTION: A wavelength conversion device comprises: a base material having an opening portion through which light passes; and a wavelength conversion element being supported by an inner surface of the opening portion, converting light of a first wave length made incident into light of a different wave length, and emitting the light converted. The wavelength conversion element includes: a first wave length converting section converting the light of the first wave length into light of a second wave length different from the light of the first wave length; and a second wave length converting section converting at least one light of the light of the first wave length and the light of the second wave length into light of a third wave length being the light of a longer wave length than that of the light of the second wave length. The first wave length converting section is positioned closer to a central axis side of the light of the first wave length than the second wave length converting section, and the inner surface and the wavelength conversion element are brought into contact with each other so as to be able to be thermally conductive.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a wavelength conversion device, an illumination device, and a projector.

2. Description of the Related Art Conventionally, a light source device that converts the wavelength of excitation light emitted from a solid light source and emits it as fluorescence is known (for example, see Patent Document 1).
The light source device described in Patent Document 1 includes a solid-state light source and a wavelength conversion device, and the wavelength conversion device has a phosphor layer, a bonding layer, and a phosphor layer fixed through the bonding layer. A heat dissipation board is provided. Among these, the phosphor layer includes a first phosphor that emits fluorescence having a wavelength longer than that of excitation light emitted from the solid-state light source and shorter than red, and the bonding layer includes the first phosphor. The phosphor particles that emit fluorescence having a wavelength longer than the emission wavelength are provided. For this reason, when excitation light is emitted from the solid light source and incident on the phosphor layer and the bonding layer, the long wavelength fluorescence and the short wavelength fluorescence are reflected by the reflection layer formed on the heat dissipation substrate, and the fluorescence The excitation light is emitted from the light incident surface of the body layer.

JP 2012-243618 A

By the way, the wavelength conversion device described in Patent Document 1 is a so-called reflection-type wavelength conversion in which light incident on the phosphor layer and the bonding layer is reflected and emitted from the incident surface of the phosphor layer. Device. When the wavelength conversion device having such a configuration is used as, for example, a transmissive wavelength conversion device, in the configuration in which the heat dissipation substrate is disposed on the front surface of the bonding layer opposite to the phosphor layer, The light whose wavelength has been converted by the layer and the bonding layer cannot be emitted. For this reason, it is necessary to provide the said fluorescent substance layer and a joining layer with the support part which supports the direction orthogonal to the light which injects into the said fluorescent substance layer and a joined body layer.
However, when the phosphor layer and the bonded body layer are supported by the support portion, it is difficult to efficiently conduct heat of the phosphor layer and the bonded layer to the support portion. In this case, since the phosphor layer and the bonding layer (wavelength conversion element) cannot be efficiently cooled, there is a problem that the emission efficiency of light emitted from the wavelength conversion layer is lowered.
That is, there is a demand for a transmission type wavelength conversion device that can suppress a decrease in wavelength conversion efficiency of light incident on the wavelength conversion layer.

  SUMMARY An advantage of some aspects of the invention is to provide a wavelength conversion device, an illumination device, and a projector that can suppress a decrease in wavelength conversion efficiency of light incident on a wavelength conversion element. This is one of the purposes.

  The wavelength conversion device according to the first aspect of the present invention converts the incident first wavelength light into light of a different wavelength, which is supported by the base material having the opening through which the light passes and the inner surface of the opening. A wavelength conversion element that emits light, and the wavelength conversion element converts the light of the first wavelength into light of a second wavelength different from the light of the first wavelength; A second wavelength conversion unit that converts at least one of light having a wavelength and light having the second wavelength into light having a third wavelength that is light having a longer wavelength than the light having the second wavelength. The one-wavelength conversion unit is positioned closer to the central axis side of the first wavelength light than the second wavelength conversion unit when viewed from the incident direction of the first wavelength light, and the inner surface and the wavelength conversion element are It is characterized by being in contact with heat conduction.

The first wavelength light can be exemplified by excitation light (blue light), and the second wavelength light can be exemplified by blue light or green light having a longer wavelength than the blue light as the excitation light. Examples of the light of three wavelengths include fluorescence and red light.
According to the first aspect, since the wavelength conversion element is supported by the inner surface of the opening of the base material, and the inner surface and the wavelength conversion element are in contact with each other so as to be able to conduct heat, the wavelength conversion element has the first wavelength. Heat generated when light is incident can be efficiently conducted to the substrate.
Here, the wavelength conversion unit (second wavelength conversion unit) that emits long-wavelength light is incident on the incident light (first wavelength conversion unit) from the wavelength conversion unit (first wavelength conversion unit) that emits short-wavelength light. It has the characteristic that the temperature is likely to rise due to light.
According to the first aspect, the first wavelength conversion unit is located on the central axis side of the light of the first wavelength, that is, the second wavelength conversion unit is located outside the first wavelength conversion unit. A 2nd wavelength conversion part contact | abuts to the inner surface of the opening part of a base material so that heat conduction is possible. As described above, the second wavelength conversion part whose temperature is likely to rise due to the incident light abuts on the inner surface of the opening, so that the heat based on the incident light of the second wavelength conversion part is applied to the base material. Conducted efficiently. According to this, since the wavelength conversion element which has the 2nd wavelength conversion part and by extension the 1st wavelength conversion part and the 2nd wavelength conversion part can be cooled efficiently, the wavelength conversion efficiency of the light which entered the wavelength conversion element concerned Can be suppressed. Therefore, it is possible to suppress a decrease in the wavelength conversion efficiency of the light incident on the wavelength conversion device.

In the first aspect, the second wavelength conversion unit has a recess at a substantially center when the second wavelength conversion unit is viewed from the light incident side of the light of the first wavelength, and the first wavelength conversion unit is It is preferable to arrange in the recess.
According to such a configuration, the first wavelength conversion unit is disposed in the recess formed substantially in the center when the second wavelength conversion unit is viewed from the light incident side of the first wavelength light. Only the second wavelength conversion unit is in contact with the inner surface. According to this, the heat | fever of the 2nd wavelength conversion part which temperature tends to rise can be reliably transmitted to a base material. Therefore, the wavelength conversion efficiency of the light incident on the wavelength conversion element can be further improved.

In the first aspect, the wavelength conversion element is preferably formed of an inorganic material.
Examples of the inorganic material include ceramic.
According to such a configuration, since the wavelength conversion element is formed of an inorganic material, deterioration of the wavelength conversion element can be suppressed as compared with a case where the wavelength conversion element is formed of an organic material. Therefore, the reliability of the light source device can be improved.

In the first aspect, it is preferable that a reflective layer that reflects at least one of the light of the first wavelength, the light of the second wavelength, and the light of the third wavelength is located on the inner surface.
According to such a configuration, since at least one of the first wavelength light, the second wavelength light, and the third wavelength light is reflected by the reflection layer located on the inner surface of the opening, the wavelength conversion element It is possible to increase the emission efficiency of light that is incident and wavelength-converted by the wavelength conversion element and emitted.

The illuminating device which concerns on the 2nd aspect of this invention is equipped with the said wavelength converter and the light source which radiate | emits the light of the said 1st wavelength, It is characterized by the above-mentioned.
According to the said 2nd aspect, there can exist an effect similar to the wavelength converter which concerns on the said 1st aspect. In addition, since the illumination device including the wavelength conversion device can efficiently conduct the heat generated by the light incident on the wavelength conversion device to the base material, the wavelength of the incident light can be stably converted. The reliability and stability of the device can be increased.

A projector according to a third aspect of the present invention includes the illumination device, a light modulation device that modulates light emitted from the illumination device, and a projection optical device that projects light modulated by the light modulation device. It is characterized by providing.
According to the said 3rd aspect, there can exist an effect similar to the wavelength converter which concerns on the said 1st aspect, and the illuminating device which concerns on the said 2nd aspect. In addition, since the illumination device including the wavelength conversion device can efficiently conduct the heat generated by the light incident on the wavelength conversion device to the base material, the wavelength of the incident light can be stably converted. The reliability and stability of the projector provided with the apparatus can be increased.

1 is a schematic diagram of a projector according to an embodiment of the invention. Schematic of the illuminating device of the projector which concerns on the said embodiment. The front view which looked at the wavelength converter which concerns on the said embodiment from the light-incidence side. Sectional drawing of the wavelength converter which concerns on the said embodiment. The front view which looked at the wavelength converter which concerns on the 1st modification of the said embodiment from the light-incidence side. The front view which looked at the wavelength converter which concerns on the 2nd modification of the said embodiment from the light-incidence side. Sectional drawing of the wavelength converter which concerns on the 3rd modification of the said embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[Schematic configuration of projector]
FIG. 1 is a schematic diagram illustrating a schematic configuration of a projector 1 according to the present embodiment.
The projector 1 is a display device that modulates a light beam emitted from a light source provided therein, forms an image according to image information, and enlarges and projects the image on a projection surface PS such as a screen.
As shown in FIG. 1, the projector 1 includes an exterior housing 2 and an image projection device 3 accommodated in the exterior housing 2. In addition, although illustration is omitted, the projector 1 includes a control device that controls the projector 1, a cooling device that cools the cooling target, and a power supply device that supplies power to the electronic components constituting the projector 1.
Such a projector 1 is supported by a base 41 having an opening 411 through which light passes, and an inner surface of the opening 411, and converts incident excitation light (first wavelength light) into light of a different wavelength. And a wavelength conversion element 43 that emits light. As will be described in detail later, the wavelength conversion element 43 includes a first wavelength conversion unit 431 that converts excitation light into blue light (second wavelength light), and at least one of the excitation light and the blue light. A second wavelength conversion unit 432 that converts the light into light having a longer wavelength than light (third wavelength light), and the first wavelength conversion unit 431 has a second wavelength when viewed from the incident direction of the excitation light. It is located on the central axis side (inside) of the excitation light with respect to the wavelength conversion unit 432, and the inner surface of the opening 411 and the wavelength conversion element 43 have a wavelength conversion device 4 that is in contact with each other so as to be able to conduct heat. One.

[Configuration of image projection apparatus]
The image projection device 3 includes an illumination device 31, a color separation device 32, a collimating lens 33, a plurality of light modulation devices 34, a color synthesis device 35, and a projection optical device 36.
The illumination device 31 emits illumination light WL. The configuration of the illumination device 31 will be described in detail later.
The color separation device 32 separates the illumination light WL incident from the illumination device 31 into three color lights of red light LR, green light LG, and blue light LB. The color separation device 32 includes dichroic mirrors 321, 322, total reflection mirrors 323, 324, 325, and relay lenses 326, 327.

The dichroic mirror 321 separates light including blue light LB and other color lights (green light LG and red light LR) from the illumination light WL from the illumination device 31. The dichroic mirror 321 transmits the blue light LB and transmits the light including the green light LG and the red light LR.
The dichroic mirror 322 separates the green light LG and the red light LR from the light separated by the dichroic mirror 321. Specifically, the dichroic mirror 322 reflects the green light LG and transmits the red light LR.

The total reflection mirror 323 is disposed in the optical path of the blue light LB, and reflects the blue light LB transmitted by the dichroic mirror 321 toward the light modulation device 34 (34B). On the other hand, the total reflection mirrors 324 and 325 are arranged in the optical path of the red light LR, and reflect the red light LR transmitted through the dichroic mirror 322 toward the light modulation device 34 (34R). The green light LG is reflected by the dichroic mirror 322 toward the light modulation device 34 (34G).
The relay lenses 326 and 327 are disposed downstream of the dichroic mirror 322 in the optical path of the red light LR. These relay lenses 326 and 327 have a function of compensating for the optical loss of the red light LR caused by the optical path length of the red light LR being longer than the optical path lengths of the blue light LB and the green light LG.

  The collimating lens 33 collimates light incident on a light modulation device 34 described later. The collimating lenses for red, green, and blue light are 33R, 33G, and 33B, respectively. In addition, the light modulation devices for red, green, and blue color lights are denoted as 34R, 34G, and 34B, respectively.

  The plurality of light modulators 34 (34R, 34G, 34B) are separated by the dichroic mirror 321 and the dichroic mirror 322, and modulate the incident color lights LR, LG, LB, respectively, to generate a color image corresponding to the image information. Form. These light modulation devices 34 are constituted by a liquid crystal panel that modulates incident light. An incident side polarizing plate 341 (341R, 341G, 341B) and an output side polarizing plate 342 (342R, 342G, 342B) are disposed on the incident side and the outgoing side of the light modulation devices 34R, 34G, 34B, respectively. .

Image light from each of the light modulation devices 34R, 34G, and 34B is incident on the color synthesis device 35. The color synthesizer 35 synthesizes image light corresponding to the color lights LR, LG, and LB, and emits the synthesized image light toward the projection optical device 36. In the present embodiment, the color composition device 35 is configured by a cross dichroic prism.
The projection optical device 36 projects the image light combined by the color combining device 35 onto a projection surface PS such as a screen. With such a configuration, an enlarged image is projected onto the projection surface PS.

[Configuration of lighting device]
FIG. 2 is a schematic diagram illustrating a configuration of the illumination device 31 in the projector 1 according to the present embodiment.
The illumination device 31 emits uniform illumination light WL with the polarization direction aligned to the color separation device 32. The illumination device 31 includes a solid-state light source 311, a condensing optical device 312, a wavelength conversion device 4, a collimator lens 315, a first lens array 316, a second lens array 317, and a polarization conversion element 318.

The solid light source 311 is a laser light source that emits excitation light (peak wavelength: approximately 455 nm) that is blue laser light as excitation light. The solid light source 311 corresponds to the light source of the present invention, and emits the excitation light corresponding to the first wavelength light of the present invention.
Note that the solid light source 311 may have one laser light source (LD: Laser Diode) or may have a plurality of laser light sources. Further, a light source device that emits blue light having a peak wavelength other than 455 nm can be used.
The condensing optical device 312 includes a first lens 3121 and a second lens 3122. The condensing optical device 312 is disposed in the optical path from the solid light source 311 to the wavelength conversion device 4, and substantially collects the excitation light and makes it incident on the wavelength conversion device 4. The first lens 3121 and the second lens 3122 are constituted by convex lenses.

  The wavelength conversion device 4 converts the wavelength of incident light (excitation light) into a different wavelength, and emits light (blue light and fluorescence) that has been wavelength-converted in the direction opposite to the light incident side of the excitation light. The detailed configuration of the wavelength conversion device 4 will be described later.

The collimating lens 315 is a convex lens and makes the light incident from the solid light source 311 substantially parallel.
The first lens array 316 includes a plurality of first small lenses 3161 that divide the light incident from the collimating lens 315 into a plurality of partial light beams. These first small lenses 3161 are arranged in a matrix in a plane orthogonal to the illumination optical axis Ax (designed optical axis and coincides with the central axis of the excitation light emitted from the solid-state light source 311). .
The second lens array 317 includes a plurality of second small lenses 3171 corresponding to the plurality of first small lenses 3161. The second lens array 317 forms an image of each first small lens 3161 incident from the first lens array 316 in the vicinity of the image forming area of each light modulation device 34R, 34G, 34B. A plurality of partial light beams are superimposed on each image forming area. Each second small lens 3171 is also arranged in a matrix in a plane orthogonal to the illumination optical axis Ax.

The polarization conversion element 318 has a function of aligning the polarization directions of the partial light beams divided by the first lens array 316.
Specifically, the polarization conversion element 318 transmits one linearly polarized light component (a linearly polarized light component having one polarization direction) of the polarized light components included in the light from the wavelength conversion device 4 as it is and the other linearly polarized light. A polarization separation layer that reflects a component (linear polarization component having the other polarization direction) in a direction perpendicular to the illumination optical axis Ax, and a direction in which the other linear polarization component reflected by the polarization separation layer is parallel to the illumination optical axis Ax And a phase difference plate that converts the other linearly polarized light component reflected by the reflective layer into one linearly polarized light component. In the present embodiment, the polarization conversion element 318 is configured to emit p-polarized light, but may be configured to emit s-polarized light.

[Configuration of wavelength converter]
FIG. 3 is a plan view of the wavelength conversion device 4 as viewed from the light incident side, and FIG. 4 is a cross-sectional view of the wavelength conversion device 4.
As described above, the wavelength conversion device 4 converts the wavelength of the incident excitation light (first wavelength light) into different wavelengths, and converts the wavelength-converted light (blue light and fluorescence) to the light incident side of the excitation light. Is a transmission type wavelength converter that emits light to the opposite side. As shown in FIGS. 3 and 4, the wavelength conversion device 4 includes a base material 41, a reflective layer 42, and a wavelength conversion element 43.

The substrate 41 is a heat radiating member that supports the wavelength conversion element 43 and radiates heat conducted from the wavelength conversion element 43. The thickness dimension of this base material 41 is set to about 1 mm, for example. Such a base material 41 is formed in a substantially rectangular shape, and an opening 411 is formed in the approximate center of the base material 41.
The opening 411 is formed in a substantially rectangular shape and penetrates the base material 41. That is, the opening 411 is an opening through which incident light passes. A reflective layer 42 is formed on the inner surface of the opening 411, and the wavelength conversion element 43 is disposed in the opening 411 so as to be in contact with the inner surface through the reflective layer 42.
In the present embodiment, such a base material 41 is fixed at a position where the excitation light emitted from the condensing optical device 312 is incident on the wavelength conversion element 43. However, the present invention is not limited to this, and the base material 41 may be configured to be rotated by a rotating device such as a motor around the center P <b> 1 of the wavelength conversion element 43. In this case, the heat of the wavelength conversion element 43 conducted to the base material 41 can be easily released.
Moreover, the base material 41 is comprised with aluminum in this embodiment. However, the present invention is not limited to this, and any material may be used as long as the material has high heat dissipation, such as metal or ceramics.

  The reflective layer 42 reflects incident light (specifically, light having a first wavelength (excitation light), light having a second wavelength (blue light), and light having a third wavelength (fluorescence)). The reflective layer 42 is deposited on the inner surface of the opening 411. For this reason, the heat of the wavelength conversion element 43 is conducted to the base material 41 through the reflective layer 42.

The wavelength conversion element 43 is provided in the opening 411 of the base material 41, and converts incident excitation light into light of a different wavelength and emits it. The wavelength conversion element 43 is a ceramic phosphor formed of an inorganic material, for example, ceramic. Such a wavelength conversion element 43 includes a first wavelength conversion unit 431 and a second wavelength conversion unit 432 as illustrated in FIGS. 3 and 4.
In the present embodiment, the thickness dimension of the wavelength conversion element 43 is set to approximately 1 mm, but the thickness dimension may be smaller than 1 mm. In this case, the thickness dimension of the base material 41 may be smaller than 1 mm in accordance with this.

The first wavelength conversion unit 431 converts the incident first wavelength light (excitation light) into different wavelength light (blue light). For example, the first wavelength conversion unit 431 converts the wavelength of the first wavelength excitation light into light having a second wavelength longer than the first wavelength.
As a specific example, the first wavelength conversion unit 431 converts the excitation light (peak wavelength: approximately 455 nm) emitted from the solid light source 311 into blue light (peak wavelength: approximately 480 nm). The wavelength conversion material of the first wavelength conversion unit 431 includes a blue phosphor, and is composed of, for example, a ceramic phosphor or a phosphor obtained by mixing phosphor powder and a glass binder. Such a 1st wavelength conversion part 431 is located in the recessed part 4321 of the 2nd wavelength conversion part 432 mentioned later.

The second wavelength conversion unit 432 converts the incident first wavelength light (excitation light) and the second wavelength light into the third wavelength light that is longer than the second wavelength light. As a specific example, the second wavelength conversion unit 432 includes excitation light (peak wavelength: approximately 455 nm) directly incident on the second wavelength conversion unit 432 and blue light emitted from the first wavelength conversion unit 431. A part of (peak wavelength: about 480 nm) is converted into fluorescence (peak wavelength: about 550 nm). Such a wavelength conversion material of the second wavelength conversion unit 432 includes a yellow phosphor, and a mixture of any one of a green phosphor and a red phosphor. The content ratio of these phosphors is set based on the wavelength of the illumination light WL emitted from the illumination device 31. Examples of such phosphors include ceramic phosphors and phosphors obtained by mixing phosphor powder and glass binder.
In the present embodiment, the concave portion 4321 is formed in the paste forming the second wavelength conversion portion 432, the paste for forming the first wavelength conversion portion 431 is disposed in the concave portion 4321, and then sintered. The wavelength conversion element 43 is formed.

The second wavelength conversion unit 432 has a recess 4321 on the incident side of the excitation light.
As shown in FIG. 3, the concave portion 4321 is formed in a substantially circular shape substantially at the center when the wavelength conversion element 43 is viewed from the light incident side. As shown in FIG. 4, the recess 4321 is formed in a bowl shape centered on the center P <b> 1 of the wavelength conversion element 43. That is, the concave portion 4321 is formed in a mortar shape whose diameter is reduced toward the light emission side of the excitation light. As described above, the first wavelength converter 431 is disposed in the recess 4321. As described above, the first wavelength conversion unit 431 has a smaller outer dimension than the second wavelength conversion unit 432 when viewed from the direction along the illumination optical axis Ax. The centers of the first wavelength conversion unit 431 and the second wavelength conversion unit 432 are arranged so as to substantially coincide with the center P1 of the wavelength conversion element 43.
Here, the second wavelength conversion unit 432 that emits light with a long wavelength has a larger Stokes loss with respect to incident light (excitation light) than the first wavelength conversion unit 431 that emits light with a short wavelength. The second wavelength conversion unit 432 has a characteristic that the temperature is likely to rise as compared with the first wavelength conversion unit 431.
For this reason, in this embodiment, the 2nd wavelength conversion part 432 which temperature rises more easily is located in the base material 41 (opening part 411) side which functions as a heat radiating member. In other words, the first wavelength conversion unit 431 that is less likely to increase in temperature is disposed inside the second wavelength conversion unit 432 when viewed from the incident direction of the excitation light. That is, the first wavelength conversion unit 431 is disposed inside the excitation light incident surface of the wavelength conversion element 43 and the second wavelength conversion unit 432 is disposed outside.

[Irradiation area of excitation light incident on wavelength conversion element]
As shown in FIGS. 3 and 4, the excitation light incident on the wavelength conversion element 43 via the condensing optical device 312 is changed from a first irradiation region R1 shown by a broken line in FIG. 3 to a one-dot chain line in FIG. In the irradiation region adjusted within the range of the second irradiation region R2 shown, that is, in the irradiation region adjusted according to the wavelength of the emitted light (illumination light) emitted from the wavelength conversion element 43. The For example, the irradiation of the excitation light incident on the wavelength conversion element 43 by changing the positions of the first lens 3121 and the second lens 3122 constituting the condensing optical device 312 (moving along the illumination optical axis Ax). The area (light beam diameter) expands and contracts.

  The first irradiation region R1 is an irradiation region when the light beam diameter is set to be the smallest by the condensing optical device 312, and the first irradiation region R1 is set at a substantially central portion of the first wavelength conversion unit 431. The In this case, substantially all of the excitation light emitted from the condensing optical device 312 enters the first wavelength conversion unit 431 and is converted into blue light (second wavelength light). The blue light travels toward the second wavelength conversion unit 432 together with the excitation light that has passed through the first wavelength conversion unit 431 without being converted into the blue light. Then, a part of the excitation light and blue light incident on the second wavelength conversion unit 432 is converted into fluorescence (light of the third wavelength), and excitation light that is not converted into the fluorescence by the second wavelength conversion unit 432 and Along with the blue light, the light travels in the second wavelength conversion unit 432 and is emitted to the outside of the second wavelength conversion unit 432. That is, a part of the excitation light incident on the first irradiation region R1 is converted into blue light and fluorescence by the first wavelength conversion unit 431 and the second wavelength conversion unit 432, together with the excitation light that has not been converted, The light is emitted from the light exit surface 4323 of the two-wavelength converter 432.

  As described above, when the excitation light is incident on the first irradiation region R <b> 1, the excitation light is incident on the light incident surface 4322 of the second wavelength conversion unit 432 among the first wavelength conversion unit 431 and the second wavelength conversion unit 432. Is not incident, the excitation light and the blue light that have traveled through the first wavelength conversion unit 431 are incident on the second wavelength conversion unit 432. That is, since the excitation light and the blue light are incident only on a part of the second wavelength conversion unit 432, the wavelength conversion element 43 (light emitting surface 4323) including the first wavelength conversion unit 431 and the second wavelength conversion unit 432 is included. The ratio of the blue light emitted from the first wavelength conversion unit 431 is higher than the ratio of the fluorescence converted by the second wavelength conversion unit 432. In other words, when the excitation light is incident on the first irradiation region R1, the ratio of blue light to the light emitted from the wavelength conversion element 43 is higher than the ratio of fluorescence.

  In addition, since the excitation light is not incident on the light incident surface 4322 of the second wavelength conversion unit 432, the temperature of the light incident surface 4322 of the second wavelength conversion unit 432 can be prevented from rising due to the excitation light. Therefore, the blue light wavelength-converted by the first wavelength conversion unit 431 and the excitation light not wavelength-converted by the first wavelength conversion unit 431 are incident on the second wavelength conversion unit 432, and these blue light And heat is generated when the excitation light is converted into fluorescence. Then, heat from the first wavelength conversion unit 431 is further conducted to the second wavelength conversion unit 432, and the conducted heat and the heat generated in the second wavelength conversion unit 432 are the second wavelength conversion unit. Conducted from 432 to the base material 41 as a heat dissipation member. That is, when the excitation light is incident on the first irradiation region R1, it is possible to suppress an increase in the heat of the second wavelength conversion unit 432 as compared with the case where the excitation light is incident on the second irradiation region R2 described later. .

On the other hand, the second irradiation region R2 is an irradiation region when the light beam diameter is set to be the largest by the condensing optical device 312, and the second irradiation region R2 includes the entire region of the first wavelength conversion unit 431 and the second region. It is set to a substantially half region of the wavelength converter 432. That is, the second irradiation region R2 is set to a region including the entire region of the first irradiation region R1.
In this case, the excitation light incident on the first wavelength conversion unit 431 was not converted because part of the light was converted into blue light and fluorescence as in the case where the excitation light was incident on the first irradiation region R1. The light is emitted from the light exit surface 4323 of the second wavelength conversion unit 432 together with the excitation light.
In addition, the excitation light (first wavelength light) incident on the second wavelength conversion unit 432 is converted into fluorescence (third wavelength light) as a part of the excitation light. Together with the excitation light that has passed through the second wavelength conversion unit 432 without being converted into the second wavelength conversion unit 432, the second wavelength conversion unit 432 travels and is emitted from the light emission surface 4323 of the second wavelength conversion unit 432. In addition, each of the lights traveling in the second wavelength conversion unit 432 and incident on the reflection layer 42 located in the opening 411 is reflected by the reflection layer 42, and the light emission surface 4323 of the second wavelength conversion unit 432. It is emitted from.
That is, a part of the excitation light incident on the second irradiation region R2 is converted into blue light and fluorescence by the first wavelength conversion unit 431 and the second wavelength conversion unit 432, together with the excitation light that has not been converted, The light is emitted from the light exit surface 4323 of the two-wavelength converter 432.

  Thus, when the excitation light is incident on the second irradiation region R2, the entire region of the light incident surface 4311 of the first wavelength conversion unit 431 and the region substantially half of the light incident surface 4322 of the second wavelength conversion unit 432 are disposed. Since the excitation light is incident, the light emitted from the wavelength conversion element 43 (light emitting surface 4323) including the first wavelength conversion unit 431 and the second wavelength conversion unit 432 is converted by the second wavelength conversion unit 432. The ratio of the fluorescent light is larger than the ratio of the blue light emitted from the first wavelength conversion unit 431. In other words, when excitation light is incident on the second irradiation region R2, the light emitted from the wavelength conversion element 43 has a blue light ratio lower than a fluorescence ratio. For this reason, when excitation light is incident on the second irradiation region R2, the light emitted from the wavelength conversion element 43 becomes illumination light having high intensities of red, blue, and green.

In addition, since excitation light is incident on substantially half of the light incident surface 4322 of the second wavelength conversion unit 432, heat from the first wavelength conversion unit 431 is conducted to the second wavelength conversion unit 432. In addition, heat is generated by the excitation light incident on the second wavelength conversion unit 432. These heats are conducted from the second wavelength conversion unit 432 to the base material 41 as a heat radiating member and radiated.
Thus, in this embodiment, since the irradiation area | region of the excitation light irradiated to the wavelength conversion element 43 in the range of 1st irradiation area | region R1 to 2nd irradiation area | region R2 can be changed, it is radiate | emitted from the said wavelength conversion element 43. Various ratios of blue light and fluorescence can be changed.

[Effect of the embodiment]
The projector 1 according to the present embodiment described above has the following effects.
Since the wavelength conversion element 43 is supported by the inner surface of the opening 411 of the base material 41 and the inner surface and the wavelength conversion element 43 are in contact with each other so as to be able to conduct heat, the wavelength conversion element 43 has light of the first wavelength (excitation Heat generated when light is incident can be efficiently conducted to the base material 41.
Here, the wavelength conversion unit (second wavelength conversion unit 432) that emits long-wavelength light receives light (first wavelength) from the wavelength conversion unit (first wavelength conversion unit 431) that emits short-wavelength light. It has a characteristic that the temperature is likely to rise due to light of a wavelength.
According to the present embodiment, the first wavelength conversion unit 431 is located on the central axis side of the excitation light, that is, the second wavelength conversion unit 432 is located outside the first wavelength conversion unit 431. The two-wavelength conversion unit 432 contacts the inner surface of the opening 411 of the base material 41 so as to allow heat conduction. As described above, since the second wavelength conversion unit 432 whose temperature is likely to rise due to the incident light contacts the inner surface of the opening 411, the heat based on the incident light of the second wavelength conversion unit 432 is Conducted efficiently to the substrate 41. According to this, since the wavelength conversion element 43 which has the 2nd wavelength conversion part 432 and by extension the 1st wavelength conversion part 431 and the said 2nd wavelength conversion part 432 can be cooled efficiently, it injects into the said wavelength conversion element 43 It can suppress that the wavelength conversion efficiency of excitation light (light of the 1st wavelength) falls. Accordingly, it is possible to suppress a decrease in the wavelength conversion efficiency of the excitation light incident on the wavelength conversion element 43.

  The first wavelength conversion unit 431 is disposed in the recess 4321 formed substantially at the center when the second wavelength conversion unit 432 is viewed from the light incident side of the first wavelength light (excitation light). Only the second wavelength conversion unit 432 is in contact with the inner surface. According to this, the heat | fever of the 2nd wavelength conversion part 432 which temperature tends to rise can be reliably conducted by the base material 41. Therefore, the wavelength conversion efficiency of the excitation light incident on the wavelength conversion element 43 can be further improved.

  Since the wavelength conversion element 43 is made of an inorganic material such as ceramic, deterioration of the wavelength conversion element 43 can be suppressed as compared with a case where the wavelength conversion element 43 is made of an organic material. Therefore, the reliability of the lighting device 31 can be improved.

  The reflection layer 42 located on the inner surface of the opening 411 reflects the first wavelength light (excitation light), the second wavelength light (blue light), and the third wavelength light (fluorescence). It is possible to increase the emission efficiency of light (illumination light) that is incident on the light and is wavelength-converted by the wavelength conversion element 43 and emitted.

  The illumination device 31 including the wavelength conversion device 4 can efficiently conduct the heat generated by the light incident on the wavelength conversion device 4 to the base material 41. Therefore, since the wavelength of the stably incident excitation light can be converted by the wavelength conversion element 43, the reliability and stability of the illumination device 31 can be increased.

  In the present embodiment, for example, the second wavelength light is blue light, and the third wavelength light is fluorescence. Therefore, the illumination light emitted from the illumination device 31 can be white light. Therefore, it is not necessary to separately provide a configuration for separately diffusing the excitation light (blue light) emitted from the solid light source 311, and it is not necessary to separately provide a light source for blue light, so that the configuration of the illumination device 31 can be simplified.

  In addition, since the illumination device 31 including the wavelength conversion device 4 can convert the wavelength of the stably incident excitation light by the wavelength conversion element 43, the reliability and stability of the projector 1 including the illumination device 31 is increased. it can.

[Modification of Embodiment]
The present invention is not limited to the above-described embodiment, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
In the embodiment, the second wavelength conversion unit 432 of the wavelength conversion device 4 has the substantially semispherical concave portion 4321, and the first wavelength conversion portion 431 is provided in the concave portion 4321. However, the present invention is not limited to this, and the shape of the recess 4321 and the shape of the first wavelength conversion unit 431 provided in the recess 4321 may be other shapes.

[First Modification]
FIG. 5 is a plan view showing a wavelength conversion device 4 </ b> A as a first modification of the wavelength conversion device 4.
For example, a wavelength conversion device 4A shown in FIG. As shown in FIG. 5, the second wavelength conversion unit 432A of the wavelength conversion element 43A has a substantially square-shaped recess 4321A at the approximate center of the second wavelength conversion unit 432A when viewed from the incident direction side of the excitation light. And the first wavelength converter 431A is disposed in the concave portion 4321A.
Even with such a wavelength conversion device 4A, the same effects as those of the wavelength conversion device 4 can be obtained, and the illumination device and the projector in which the wavelength conversion device 4A is used instead of the wavelength conversion device 4 can also provide the illumination. The same effects as those of the device 31 and the projector 1 can be obtained.
In addition, the concave portion 4321A has a substantially square shape when viewed from the incident direction side of the excitation light. Other polygonal shapes may be used.

[Second Modification]
FIG. 6 is a plan view showing a wavelength conversion device 4 </ b> B as a second modification of the wavelength conversion device 4.
For example, the wavelength conversion device 4B illustrated in FIG. 6 includes the base material 41 and the reflective layer 42 as well as the wavelength conversion device 4, and includes a wavelength conversion element 43B instead of the wavelength conversion element 43. As shown in FIG. 6, the second wavelength conversion section 432B of the wavelength conversion element 43B has a substantially rectangular shape extending from one end to the other end of the inner surface of the opening 411 with the approximate center of the second wavelength conversion section 432B interposed therebetween. The concave portion 4321B has a shape, and the first wavelength conversion portion 431B is disposed in the concave portion 4321B.
Such a wavelength conversion device 4B can provide the same effects as the wavelength conversion device 4. The illumination device and projector in which the wavelength conversion device 4B is used instead of the wavelength conversion device 4 can also provide the illumination. The same effects as those of the device 31 and the projector 1 can be obtained.

  That is, in the said embodiment, the shape of the recessed part 4321 of the 2nd wavelength conversion part 432 may be what kind of shape, and the depth can also be set freely. Thus, by freely setting the shape of the concave portion 4321, the volume of the first wavelength conversion portion 431 provided in the concave portion 4321 is also changed, and the wavelength conversion element is similar to the case where the irradiation region is changed. Various ratios of the blue light and the fluorescence emitted from the light 43 can be set.

[Third Modification]
Moreover, in the said embodiment, although the 2nd wavelength conversion part 432 has the recessed part 4321 and the 1st wavelength conversion part 431 was provided in the said recessed part 4321, it is not restricted to this.
FIG. 7 is a cross-sectional view illustrating a wavelength conversion device 4 </ b> C as a third modification of the wavelength conversion device 4.
In the present modification, the second wavelength conversion unit 432C includes a through hole 4321C instead of the concave portion 4321. As shown in FIG. 7, a through-hole 4321C is formed at a substantially central portion of the second wavelength conversion portion 432B of the wavelength conversion element 43C. The through-hole 4321C is a through-hole extending from the light incident surface 4322 of the second wavelength conversion unit 432B toward the light emitting surface 4323, and the size of the through hole 4321C decreases toward the light emitting surface 4323. A first wavelength conversion portion 431C is provided in the through hole 4321C. For this reason, in this modification, the first wavelength conversion unit 431 </ b> C includes the light incident surface 4311 and the light emitting surface 4312, and the area of the light incident surface 4311 is larger than that of the light emitting surface 4312.
For this reason, in this modified example, when the excitation light is incident on the first irradiation region R1, most of the excitation light is transmitted only through the first wavelength conversion unit 431C. Light and blue light are emitted. For this reason, it can be suitably used as an illumination device that emits only blue light.

In addition, when excitation light is incident on the second irradiation region R2, excitation light, blue light, and fluorescence are emitted from the wavelength conversion element 43C in the same manner as the wavelength conversion elements 43, 43A, and 43B. It can be suitably used as an illumination device including the wavelength conversion element 43C and a projector including the illumination device. That is, in this modification, when excitation light is incident on the second irradiation region R2, the same effect as the wavelength conversion device 4 can be obtained, and the wavelength conversion device 4C is replaced with the wavelength conversion device 4. Even with the illumination device and projector employed in this manner, the same effects as those of the illumination device 31 and the projector 1 can be obtained.
That is, the second wavelength conversion unit 432 does not have to have the concave portion 4321, and the first wavelength conversion unit 431 only needs to be located inside the second wavelength conversion unit 432.

  In the above embodiment, the base material 41 has the opening 411. However, the present invention is not limited to this. For example, the base material is formed by an annular first base material and a second base material, respectively, and is sandwiched between the first base material and the second base material at a side perpendicular to the first direction of the excitation light. A configuration in which an annular wavelength conversion element is provided and the center of the substrate is rotated about the rotation center may be employed. Even in this case, the heat of the wavelength conversion element 43 conducted to the substrate can be easily released.

In the above embodiment, the condensing optical device 312 includes the first lens 3121 and the second lens 3122, and the positions of the first lens 3121 and the second lens 3122 are moved along the illumination optical axis Ax. The irradiation range can be changed in the range from the first irradiation region R1 to the second irradiation region R2 of the wavelength conversion element 43. However, the present invention is not limited to this. For example, the irradiation area may be set in advance.
In this case, when changing the ratio of blue light and fluorescence of light incident on and emitted from the wavelength conversion element 43, any one of the wavelength conversion elements 43A to 43C is provided instead of the wavelength conversion element 43. You can do that. Even in this case, the same effects as those of the lighting device 31 and the projector 1 according to the embodiment can be obtained.

  In the above embodiment, the wavelength conversion element 43 is made of an inorganic material (ceramic phosphor). However, the present invention is not limited to this. For example, the wavelength conversion element 43 may be formed of an organic material such as a resin (such as a phosphor containing a resin binder). In this case, for example, if the thickness dimension of the base material 41 and the wavelength conversion element 43 is increased, the area of the inner surface of the opening 411, that is, the area of the base material 41 with which the wavelength conversion element 43 abuts can be increased. Efficiency can be increased.

  In the above embodiment, the reflective layer 42 is located on the inner surface of the opening 411. However, the present invention is not limited to this. For example, the reflective layer 42 may not be provided. In this case, since the wavelength conversion element 43 (second wavelength conversion part 432) and the inner surface of the opening 411 are in direct contact with each other, the heat of the wavelength conversion element 43 functions more efficiently as the inner surface of the opening 411, and thus as a heat dissipation member. It is possible to conduct to the base material 41.

  In the said embodiment, when the illuminating device 31 has the solid light source 311 which radiate | emits the excitation light which has a peak wavelength in a wavelength range of about 455 nm as a light source which radiate | emits the light of the 1st wavelength which injects into the wavelength converter 4. did. The wavelength conversion device 4 emits fluorescence including green light and red light as the second wavelength light. However, the present invention is not limited to this. If the wavelength of light incident on the wavelength conversion element is different from the wavelength of light generated in the wavelength conversion layer of the wavelength conversion element, the first wavelength, the second wavelength, and the The three wavelengths are not limited to the above. The same applies to the case where any of the wavelength conversion devices 4A to 4C is employed instead of the wavelength conversion device 4.

In the above embodiment, the projector 1 includes the three light modulation devices 34 (34R, 34G, and 34B). However, the present invention is not limited to this, and the present invention can also be applied to a projector including, for example, two or less or four or more light modulation devices.
Further, the light modulation device 34 has a configuration including a liquid crystal panel in which the light incident surface and the light emitting surface are different. However, the present invention is not limited to this, and a light modulation device including a reflective liquid crystal panel in which the light incident surface and the light emitting surface are the same may be employed. In addition, as long as the light modulation device can modulate an incident light beam and form an image according to image information, a device using a micromirror, for example, a device using a DMD (Digital Micromirror Device) or the like can be used. You may employ | adopt a light modulation apparatus.

Moreover, in the said embodiment and the said modifications 1-3, the wavelength converters 4 and 4A-4C demonstrated as a wavelength converter used for the projector 1. FIG. However, the present invention is not limited to this. For example, the wavelength converters 4, 4 </ b> A to 4 </ b> C may be configured to be used for an independently available illumination device instead of the illumination device 31 of the projector 1.
Even when used as the illumination device, the ratio of blue light and fluorescence of emitted light is changed by changing the irradiation region between the first irradiation region R1 and the second irradiation region R2. It can be suitably used as a lighting device that can be used.

  DESCRIPTION OF SYMBOLS 1 ... Projector, 2 ... Exterior casing, 31 ... Illumination device, 311 ... Solid light source (light source), 34, 34R, 34G, 34B ... Light modulation device, 36 ... Projection optical device, 4, 4A, 4B, 4C ... Wavelength Conversion device, 41 ... base material, 411 ... opening, 42 ... reflective layer, 43, 43A, 43B, 43C ... wavelength conversion element, 431, 431A, 431B, 431C ... first wavelength conversion unit, 4311 ... light incident surface, 4312: Light exit surface, 432, 432A, 432B, 432C ... Second wavelength converter, 4321, 4321A, 4321B ... Recess, 4322 ... Light entrance surface, 4323 ... Light exit surface, Ax ... Illumination optical axis, P1 ... Center, R1: first irradiation region, R2: second irradiation region.

Claims (6)

A substrate having an opening through which light passes;
A wavelength conversion element that is supported by the inner surface of the opening and converts the incident first wavelength light into light of a different wavelength and emits the light, and
The wavelength conversion element is:
A first wavelength converter that converts the light of the first wavelength into light of a second wavelength different from the light of the first wavelength;
A second wavelength conversion unit that converts at least one of the first wavelength light and the second wavelength light into a third wavelength light that is longer than the second wavelength light. ,
The first wavelength conversion unit is located closer to the central axis side of the light of the first wavelength than the second wavelength conversion unit, as viewed from the incident direction of the light of the first wavelength,
The wavelength conversion device, wherein the inner surface and the wavelength conversion element are in contact with each other so as to allow heat conduction. In the wavelength converter of Claim 1,
The second wavelength conversion unit has a concave portion at substantially the center when the second wavelength conversion unit is viewed from the light incident side of the first wavelength light,
The wavelength converter according to claim 1, wherein the first wavelength converter is disposed in the recess. In the wavelength converter of Claim 1 or Claim 2,
The wavelength conversion device, wherein the wavelength conversion element is made of an inorganic material. In the wavelength converter as described in any one of Claims 1-3,
The wavelength converter according to claim 1, wherein a reflective layer that reflects at least one of the light of the first wavelength, the light of the second wavelength, and the light of the third wavelength is located on the inner surface. The wavelength conversion device according to any one of claims 1 to 4,
And a light source that emits light of the first wavelength. A lighting device according to claim 5;
A light modulation device that modulates light emitted from the illumination device;
And a projection optical device that projects light modulated by the light modulation device.

Images