JP2007220326A - Light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new light-emitting device that enables to obtain a green color from a light-emitting element emitting light other than green light. <P>SOLUTION: The light-emitting device is provided with an excitation light source 10 for emitting excitation light, a light guide 20 in which a refractive index at the center (the core) in a cross-section is higher than that at the periphery (cladding) and which propagates the excitation light, a wavelength conversion member 40 which absorbs the excitation light propagated with the light guide 20 so as to emit light in a prescribed wavelength region by subjecting the excitation light to wavelength conversion, and a cut-off member 70 for cutting off at least a partial wavelength of the light emitted from the wavelength conversion member 40 and that of the excitation light 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a light-emitting device, and more particularly to a light-emitting device that can be used for a laser disc or an endoscope.

In laser displays and endoscopes (see Patent Document 1), light of various wavelengths is created by combining various wavelengths of light. To achieve these, blue, red, A light emitting device capable of emitting light such as green is required.
JP 2005-205195 A

However, this light-emitting device has the following problems as to how to configure the light source. First, it is conceivable that the light source is composed of LEDs, but there is a problem that the luminance of LEDs is low. Next, it is conceivable that the light source is composed of a solid-state laser such as an SHD laser or a gas laser. However, since these structures are complicated, there is a problem that the light emitting device becomes large and power consumption increases.
Therefore, it is considered that the light source is preferably composed of a laser diode. However, no laser diode that emits green light has been developed yet (although there are laser diodes that emit a green component, there is a green color due to color mixture). do not become). Therefore, when the light source is formed of a laser diode, it is necessary to obtain green from a laser diode that emits light other than green.
Accordingly, an object of the present invention is to provide a new light-emitting device that emits green light using a laser diode as a light source, which has high luminance, is suitable for downsizing, and has low power consumption.

  According to the present invention, the above problem is solved by the following means.

According to a first aspect of the present invention, there is provided an excitation light source that emits excitation light, a light guide that propagates the excitation light, wherein a refractive index of a central portion (core) of a cross section is higher than a refractive index of a peripheral portion (cladding), and the light A wavelength conversion member that absorbs the excitation light propagated by the guide, converts the wavelength and emits light in a predetermined wavelength range, and blocks the light emitted from the wavelength conversion member and at least a part of the wavelengths of the excitation light A light-emitting device including a blocking member.
In the present invention, “blocking” means “absorbing” or “reflecting” at least part of the light emitted from the wavelength conversion member and the excitation light, and the light other than the “absorbed” or “reflected” light. To “transmit” light

  A second invention is the light emitting device according to the first invention, wherein the shielding member is in a lens shape.

  A third invention is the light emitting device according to the second invention, wherein the shielding member includes a diffusion member.

4th invention is equipped with the reflection member which reflects at least one part of the light inject | emitted from the said wavelength conversion member, and the said excitation light, Any 1st invention-3rd invention characterized by the above-mentioned. The light emitting device according to the above.
The reflective member refers to a member that transmits a specific wavelength but reflects other wavelengths.

  In a fifth aspect of the present invention, the wavelength conversion member includes two or more layers, and the reflection member is sandwiched between layers of the wavelength conversion member. Device.

  A sixth invention is the light emitting device according to the fourth invention or the fifth invention, wherein the reflecting member reflects the excitation light.

  According to a seventh invention, in any one of the fourth to sixth inventions, the reflecting member reflects light having a shorter wavelength than the vicinity of the emission peak wavelength of the wavelength conversion member. Such a light emitting device. Here, the shorter wavelength side than the vicinity of the emission peak wavelength means light on the shorter wavelength side than “emission peak wavelength−20 nm” (not including light of “emission peak wavelength−20 nm”).

  An eighth invention is the light emitting device according to any one of the fourth to seventh inventions, wherein the reflecting member reflects light of about 420 nm or less.

  According to a ninth aspect of the present invention, a light guide tip member is provided at an emission side end of the light guide, and a reflection film that reflects light in a predetermined wavelength region is formed on an end surface of the light guide tip member. A light-emitting device according to any one of the first to eighth inventions. Here, the predetermined wavelength range is not limited at all. The reflective film refers to a film that reflects at least 90% of light.

  According to the present invention, since a light in a specific wavelength region can be extracted from the light emitting device, a new light emitting device that emits green light using a laser diode as a light source, which is suitable for downsizing with high brightness, is provided. It becomes possible to do.

  The best mode for carrying out the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a diagram showing an outline of a light emitting device according to an embodiment of the present invention, and FIG. 2 is a portion where a light guide tip member 30, a wavelength conversion member 40, and a blocking member 70 are arranged in FIG. It is a figure which expands and shows.
As shown in FIG. 1, the light emitting device of the present invention is mainly composed of an excitation light source 10, a light guide 20, a light guide tip member 30, a wavelength conversion member 40, a reflection member 60, and a blocking member 70. Is done. As shown in FIG. 2, a light guide tip member 30 is provided at the end of the light guide 20 on the emission side, and a reflection film 50 that reflects light in a predetermined wavelength range on the end surface of the light guide tip member 30. Is formed. The wavelength conversion member 40 is attached to the light guide tip member 30 with the reflection film 50 interposed therebetween, the reflection member 60 is attached to the emission side of the wavelength conversion member 40, and the blocking member 70 is the reflection member 60. It is attached to the exit side.

[Excitation light source 10]
The excitation light source 10 is a light source for emitting excitation light, and may be any light as long as it can excite a fluorescent substance to be described later. As shown in FIG. 1, the excitation light source 10 includes a light emitting element 11 and the like, and is configured to guide light emitted from the light emitting element 11 from the emitting unit 12 to the light guide 20. A lens 13 is usually provided between the light emitting element 11 and the emitting portion 12. As the light emitting element 11, a semiconductor light emitting element, a lamp, or the like, and a device using an electron beam, plasma, EL, or the like as an energy source can be used. Especially, it is preferable that they are light emitting elements, such as a light emitting diode element (LED) and a laser diode element (LD), especially a laser diode element.

[Light guide 20]
Examples of the light guide 20 include those that propagate light emitted from the excitation light source 10 to the wavelength conversion member 40. Examples of the light guide 20 include a very thin glass fiber used as a light transmission path when transmitting light, and a combination of a material having a high refractive index and a material having a low refractive index, or a reflectance. A member using a member having a high height can be used. Especially, in the full length or partial length of the light guide 20, the thing of the double structure which surrounds the center part (core) of a cross section with a peripheral part (clad) is preferable, and the refractive index of a core is higher than the refractive index of a clad. From the viewpoint that the optical signal can be sent without being attenuated, it is more preferable. The light guide 20 may be either a single-wire fiber or a multi-wire fiber, but is preferably a single-wire fiber. Moreover, either a single mode fiber or a multimode fiber may be used, but a multimode fiber is preferable.

[Light guide tip member 30]
The tip of the light guide 20, that is, the end not connected to the excitation light source is preferably supported by the light guide tip member 30. Such a light guide tip member 30 makes it easy to fix the light emitted from the light guide 20. Further, the light emission efficiency can be improved according to the material and shape, and the assembly as a light emitting device is facilitated.
The light guide tip member 30 may have, for example, a cylindrical shape that surrounds the outer periphery of the light guide 20, or various functional films / members and the like are integrated to impart various functions to the end surface of the light guide 20. Alternatively, it may be attached individually or separately, or a cover or cap for covering the end face of the light guide 20, various functional films / members, or the like may be attached integrally or separately.
In the present embodiment, as shown in FIG. 2, in order to increase the reflectivity, only the end surface of the light guide tip member 30 is provided with a reflection film 50 that reflects light in a predetermined wavelength region, and is specularly reflected. Or irregular reflection, or processing such as unevenness. Thus, once the excitation light or wavelength-converted light emitted from the light guide 20 returns to the light guide 20 side by reflection, it is reflected again by the light guide tip member 30 to thereby obtain the excitation light and wavelength. The converted light can be effectively extracted outside, and the output can be improved. However, in the present invention, the reflective film 50 may not be provided. The “predetermined wavelength range” for the light reflected by the reflective film 50 is not limited as long as the reflective film 50 can perform the above-described function as much as possible.

[Wavelength conversion member 40]
The wavelength conversion member 40 absorbs part or all of the excitation light emitted from the excitation light source 10 and converts the wavelength to light in a predetermined wavelength range, for example, red, green, blue, and yellow that is an intermediate color thereof. Can emit light having an emission spectrum in blue-green, orange, etc., and is composed of, for example, a fluorescent material, a pigment, or the like. In addition, the wavelength conversion member may be composed only of the fluorescent material as described above, but optionally, a resin together with a filler capable of reflecting, scattering and / or diffusing light irradiated from the outside. It can be formed by mixing with a covering member such as. Thereby, the wavelength conversion member 40 can be easily fixed to the light guide 20. Moreover, since the wavelength conversion member 40 can be arrange | positioned uniformly, a light-emitting device with few color irregularities can be obtained.
In addition, the wavelength conversion member 40 may be formed of a single type of fluorescent material or the like, or may be formed of a single layer in which two or more types of fluorescent materials are mixed, or may be a single type of fluorescent material. Two or more monolayers containing a substance or the like may be laminated, or two or more monolayers in which two or more kinds of fluorescent substances or the like are mixed may be laminated.
Further, as shown in FIG. 1, the wavelength conversion member 40 may be provided at the distal end portion of the light guide 20 for deriving the excitation light 1, that is, the output portion 21, or between the excitation light source 10 and the light guide 20. You may provide in the emission part 12 of the excitation light 1 which is a connection part. In the latter case, the light guide 20 can also be used at a location where the tip of the light guide 20 becomes dirty. Further, the wavelength conversion member 40 can be easily replaced. Furthermore, productivity can be improved by providing the wavelength conversion member 40 at various positions.
Further, the wavelength conversion member 40 may be provided in a part of the light guide 20 by, for example, adding a fluorescent material or the like to the core material.
In addition, when the wavelength conversion member 40 is comprised with a fluorescent material, the fluorescent material is contained in resin and it is set as the wavelength conversion member 40, for example. The fluorescent substance may be any substance that absorbs light from a semiconductor light emitting element having a nitride semiconductor as a light emitting layer and converts the light to light of a different wavelength. For example, nitride phosphors / oxynitride phosphors mainly activated by lanthanoid elements such as Eu and Ce, lanthanoid phosphors such as Eu, and alkalis mainly activated by transition metal elements such as Mn Earth halogen apatite phosphor, alkaline earth metal borate halogen phosphor, alkaline earth metal aluminate phosphor, alkaline earth silicate, alkaline earth sulfide, alkaline earth thiogallate, alkaline earth silicon nitride At least selected from organic and organic complexes mainly activated by lanthanoid elements such as germanate or lanthanoid elements such as Ce, rare earth aluminate, rare earth silicate or Eu Any one or more are preferable. As specific examples, the following phosphors can be used, but are not limited thereto.
A nitride phosphor mainly activated by a lanthanoid element such as Eu or Ce is M ₂ Si ₅ N ₈ : Eu (M is at least one selected from Sr, Ca, Ba, Mg, Zn). There is.) In addition to M ₂ Si ₅ N ₈ : Eu, MSi ₇ N ₁₀ : Eu, M _1.8 Si ₅ O _0.2 N ₈ : Eu, M _0.9 Si ₇ O _0.1 N ₁₀ : Eu (M Is at least one selected from Sr, Ca, Ba, Mg, and Zn.
Nitride phosphors activated by rare earth elements such as Eu and containing Group II elements M, Si, Al, and N, absorb ultraviolet or blue light and emit light in the yellow-red to red range. To do. The nitride phosphor has the general formula _{M w Al x Si y N (} (2/3) w + x + (4/3) y): shown by Eu, rare earth elements and tetravalent element to an additional element, 3 At least one element selected from valent elements. M is at least one selected from the group consisting of Mg, Ca, Sr, and Ba.
In the above general formula, the ranges of w, x, and y are preferably 0.04 ≦ w ≦ 9, x = 1, 0.056 ≦ y ≦ 18. The range of w, x, and y may be 0.04 ≦ w ≦ 3, x = 1, 0.143 ≦ y ≦ 8.7, more preferably 0.05 ≦ w ≦ 3, x = 1, 0. 167 ≦ y ≦ 8.7.
The nitride phosphor is generally added boron B formula _{M w Al x Si y B z} N ((2/3) w + x + (4/3) y + z): can also be Eu. Also in the above, M is at least one selected from the group consisting of Mg, Ca, Sr, and Ba, and 0.04 ≦ w ≦ 9, x = 1, 0.056 ≦ y ≦ 18, 0.0005 ≦ z ≦ 0.5. When boron is added, the molar concentration z is set to 0.5 or less as described above, preferably 0.3 or less, and further set to be greater than 0.0005. More preferably, the molar concentration of boron is set to 0.001 or more and 0.2 or less.
Further, these nitride phosphors are at least one selected from the group of La, Ce, Pr, Gd, Tb, Dy, Ho, Er, Lu, or any one of Sc, Y, Ga, In, Alternatively, any one of Ge and Zr is contained. By containing these, luminance, quantum efficiency, or peak intensity equal to or higher than Gd, Nd, and Tm can be output.
An oxynitride phosphor mainly activated by a lanthanoid element such as Eu or Ce is MSi ₂ O ₂ N ₂ : Eu (M is at least one selected from Sr, Ca, Ba, Mg, Zn) Etc.).
Alkaline earth halogen apatite phosphors mainly activated by lanthanoid elements such as Eu and transition metal elements such as Mn include M ₅ (PO ₄ ) ₃ X: R (M is Sr, Ca, Ba, At least one selected from Mg and Zn, X is at least one selected from F, Cl, Br, and I. R is at least one selected from Eu, Mn, Eu and Mn. Etc.).
The alkaline earth metal borate phosphor has M ₂ B ₅ O ₉ X: R (M is at least one selected from Sr, Ca, Ba, Mg, Zn. X is F, Cl , Br, or I. R is Eu, Mn, or any one of Eu and Mn.).
Alkaline earth metal aluminate phosphors include SrAl ₂ O ₄ : R, Sr ₄ Al ₁₄ O ₂₅ : R, CaAl ₂ O ₄ : R, BaMg ₂ Al ₁₆ O ₂₇ : R, BaMg ₂ Al ₁₆ O ₁₂ : R, BaMgAl ₁₀ O ₁₇ : R (R is one or more of Eu, Mn, Eu and Mn).
The alkaline earth silicate _{phosphor, (Sr 1-a-b} -x Ba a Ca b Eu x) 2 SiO 4 (0 ≦ a ≦ 1,0 ≦ b ≦ 1,0.005 ≦ x ≦ 0 .1).
Examples of the alkaline earth sulfide phosphor include La ₂ O ₂ S: Eu, Y ₂ O ₂ S: Eu, and Gd ₂ O ₂ S: Eu.
Examples of rare earth aluminate phosphors mainly activated with lanthanoid elements such as Ce include Y ₃ Al ₅ O ₁₂ : Ce, (Y _0.8 Gd _0.2 ) ₃ Al ₅ O ₁₂ : Ce, Y _{3 (Al 0.8 Ga 0.2) 5 O} 12: Ce, and the like (Y, Gd) 3 (Al , Ga) YAG -based phosphor represented by the compositional formula of _{5 O 12.} Further, there are Tb ₃ Al ₅ O ₁₂ : Ce, Lu ₃ Al ₅ O ₁₂ : Ce, etc. in which a part or all of Y is substituted with Tb, Lu or the like.
Other phosphors include ZnS: Eu, Zn ₂ GeO ₄ : Mn, MGa ₂ S ₄ : Eu (M is at least one selected from Sr, Ca, Ba, Mg, Zn. X is At least one selected from F, Cl, Br, and I).
The phosphor described above contains at least one selected from Tb, Cu, Ag, Au, Cr, Nd, Dy, Co, Ni, and Ti instead of Eu or in addition to Eu as desired. You can also.
The Ca—Al—Si—O—N-based oxynitride glass phosphor is expressed in terms of mol%, CaCO ₃ is converted to CaO, 20 to 50 mol%, Al ₂ O ₃ is 0 to 30 mol%, SiO 25 to 60 mol%, AlN 5 to 50 mol%, rare earth oxide or transition metal oxide 0.1 to 20 mol%, and oxynitride glass having a total of 5 components of 100 mol% as a base material This is a phosphor. In addition, in the phosphor using oxynitride glass as a base material, the nitrogen content is preferably 15 wt% or less, and other rare earth element ions serving as a sensitizer in addition to rare earth oxide ions are used as rare earth oxides. It is preferable to contain as a co-activator in content in the range of 0.1-10 mol% in fluorescent glass.
Moreover, it is fluorescent substance other than the said fluorescent substance, Comprising: The fluorescent substance which has the same performance, an effect | action, and an effect can also be used.

[Reflection member 60]
The light emitting device according to the embodiment can be provided with a reflecting member 60 that reflects at least part of light emitted from the wavelength conversion member 40 and excitation light. The reflection member 60 includes an excitation light reflection member that reflects excitation light, a wavelength conversion light reflection member that reflects light on the shorter wavelength side than the vicinity of the emission peak wavelength of the wavelength conversion member, and an ultraviolet region that reflects light in the ultraviolet region. A light reflecting member is conceivable.
In the present invention, as shown in FIG. 3, the reflecting member 60 may not be provided. In the form shown in FIG. 3, a light guide tip member 30 is provided at an end of the light guide 20 on the emission side, and a reflection film 50 that reflects light in a predetermined wavelength region is formed on the end surface of the light guide tip member 30. ing. In the form shown in FIG. 3, the wavelength conversion member 40 is attached to the light guide tip member 30 with the reflective film 50 interposed therebetween, and the blocking member 70 is attached to the emission side of the wavelength conversion member 40.
(Excitation light reflecting member)
The excitation light reflecting member can be used for preventing excitation light from being directly irradiated to the outside, leakage of excitation light from an unintended portion, and the like. Thereby, for example, the luminous efficiency can be improved by returning the excitation light that has passed through the wavelength conversion member but was not wavelength-converted with a fluorescent substance or the like into the wavelength conversion member again. Therefore, the excitation light reflecting member is preferably formed of a material that allows only the wavelength-converted light having a specific wavelength to pass therethrough and reflects the excitation light. Further, for example, the excitation light reflecting member is preferably arranged at least in the wavelength conversion member 40 where light is converted, as shown in FIG. Thereby, the irradiation of the excitation light to the outside can be reduced, and the light emission efficiency can be improved.
(Wavelength conversion light reflecting member)
The wavelength-converted light reflecting member prevents the light wavelength-converted by the wavelength converting member from returning to the excitation light incident side and reflects the light returned to the excitation light incident side to extract it as light. Can be used. Therefore, the wavelength conversion reflection member is preferably formed of a material that allows only light of a specific wavelength to pass and reflects the specific wavelength, that is, the wavelength-converted light. Thereby, the light which returned to the excitation light incident side can be reflected, and the luminous efficiency can be improved. 2 shows a state in which the reflecting member is arranged in the light-derived portion where the wavelength is converted, the wavelength-converting light reflecting member is preferably arranged at least in the excitation light introducing portion of the wavelength converting member 40. .
(Ultraviolet light reflecting member)
According to the ultraviolet region light reflecting member, even when a light emitting element that emits ultraviolet rays is used as an excitation light source, ultraviolet rays are reflected so that they are not emitted from the light emitting device. Can do.

[Blocking member 70]
In the light emitting device according to the embodiment, a blocking member 70 is provided on the emission side of the wavelength conversion member 40, and this blocking member 70 is at least part of the light emitted from the wavelength conversion member 40 and the excitation light. Block the light. Thereby, only light of a predetermined wavelength can be extracted. For example, when blue light (445 nm) is emitted from the laser diode of the excitation light source 10 and a LAG phosphor (Lu ₃ Al ₅ O ₁₂ : Ce) is used for the wavelength conversion member 40, light blue light is emitted from the entire light emitting device. However, if light having a wavelength of 445 nm or less is cut using the blocking member 70, green having a wavelength of 445 nm or more can be obtained. Thus, even when a light emitting element that emits green light has not been developed, or even when a light emitting element that emits green light cannot be used for some reason, a light emitting device that emits green light can be obtained. it can.
Further, according to the blocking member 70, even when a light emitting element that emits ultraviolet rays is used as the excitation light source 10, ultraviolet rays can be blocked, so that a light emitting device that is friendly to people and the environment can be obtained.
The blocking member 70 can contain a diffusing member used to improve luminous efficiency by mainly diffusing excitation light. In this way, light emitted from the light emitting device can be reduced in color variation. As the diffusing member, it is preferable to use, for example, a resin having a relatively high refractive index among the above-described resins, a material containing the above-described filler in the above-described resin, or the like. Especially, what contains a filler in a silicone resin is preferable.
In addition, if the shape of the blocking member 70 is formed in a lens shape, the light distribution of light emitted from the light emitting device can be made specific.

  As described above, the light emitting device according to the embodiment includes the blocking member 70 and the reflecting member 60, so that even if a light emitting element that emits green light has not been developed, or for some reason. Even when a light-emitting element that emits green light cannot be used, a light-emitting device that emits green light can be obtained. In addition, according to the light emitting device according to the embodiment, it is possible to reflect light having a wavelength of 445 nm or less including the ultraviolet region and irradiate the reflected light to the wavelength conversion member 40 to increase excitation efficiency.

In addition, the above description is for actualizing the technical idea of the present invention, and does not limit the present invention.
For example, the blocking member and the reflecting member described above are not limited to being provided on the light guide tip member, the wavelength conversion member, or the blocking member, and can be provided at appropriate positions. The light guide tip member, the wavelength converting member, the blocking member, and the reflecting member can be spatially separated. Although not shown, the blocking member and the reflecting member can be provided between the layers when the wavelength conversion member is composed of two or more layers. Can be increased.
In addition, as shown in FIG. 1, the light emitting device of the present invention may be composed of one excitation light source 10, one light guide 20, and one wavelength conversion member 30. Alternatively, a light emitting device in which a plurality of light emitting devices of one unit are mounted may be used.
Moreover, you may comprise so that one excitation light source may be equipped with the several light guide and the wavelength conversion member corresponding to it. Moreover, you may have the structure which wavelength-converts the light from these light guides with one excitation light source, and the light from these light guides with one wavelength conversion member. Furthermore, you may have the structure which wavelength-converts the light from these several light sources, the light guide corresponding to it, and the light from these light guides by one wavelength conversion member. Further, these light emitting devices may be combined and used as one light emitting device.

A laser diode that emits 445 nm light is used as a light emitting element of an excitation light source, a wavelength conversion member containing LAG (Lu ₃ Al ₅ O ₁₂ : Ce) is used, and a dielectric multilayer film that blocks 445 nm light is used as a blocking member. When used, green light can be obtained.

A laser diode that emits light of 445 nm is used as a light emitting element of an excitation light source, a wavelength conversion member containing LAG (Lu ₃ Al ₅ O ₁₂ : Ce) is used, a green component having a high y value is transmitted, and other components are transmitted. When using a reflective dielectric multilayer film as a blocking member and using a reflective film that reflects light in a predetermined wavelength range (reflective film that reflects light that is irradiated from the light guide and re-enters the light guide), Green light with a high y value can be obtained.

A laser diode that emits 405 nm light is used as the light emitting element of the excitation light source, a wavelength conversion member containing CCA + YAG (two-layer stack) is provided from the excitation light source side, and a dielectric multilayer film that reflects 405 nm light is used as a blocking member Use. With 405 nm light, CCA can be excited, but YAG cannot be excited. Therefore, if a reflection member that reflects light of 405 nm is provided between CCA and YAG, excitation efficiency can be increased. CCA is an alkaline earth halogen apatite phosphor activated by Eu, Ca ₅ (PO ₄ ) ₃ Cl: Eu. In addition, YAG is a rare earth aluminate phosphor activated by Ce, Y ₃ Al ₅ O ₁₂ : Ce (wherein Y is partially substituted with Gd and Al is partially substituted with Ga). is there.

When a laser diode that emits light of 405 nm is used as a light emitting element of an excitation light source, a wavelength conversion member containing Sr thiogallate is used, and a dielectric multilayer film that removes a green component having a low y value is used as a blocking member, y High value green light can be obtained. Here, further, if the light having a wavelength of 405 nm is reflected by the dielectric multilayer film as the blocking member, the efficiency is improved. In addition, Sr thiogallate is SrGa ₂ S ₄ : Eu.

A laser diode that emits 445 nm light is used as the light emitting element of the excitation light source, a wavelength conversion member containing LAG + CASBN (two-layer stack) is provided from the excitation light source side, and a part of the 445 nm light is transmitted and a part is reflected When the dielectric multilayer film is provided as a blocking member, the transmitted light becomes a part of white, and the reflected light is used as an excitation light source for the wavelength conversion member, so that the luminous efficiency is improved as a whole. Note that LAG is (Lu ₃ Al ₅ O ₁₂ : Ce). Further, CASBN is (CaAlSiB _0.005 N _3.005 : Eu).

  The light-emitting device of the present invention can be used for lighting fixtures, on-vehicle lighting, displays, indicators, and the like. It can also be used for endoscope devices that image the inside of living bodies, fiberscopes that can illuminate narrow gaps and dark spaces, and various industrial devices that require illumination that does not leak current or generate heat. it can.

It is a figure which shows the outline of the light-emitting device which concerns on embodiment of this invention. It is a figure which expands and shows the part in which the light guide front-end | tip member 30, the wavelength conversion member 40, and the interruption | blocking member 70 in FIG. 1 are arrange | positioned. FIG. 2 is an enlarged view showing a portion where the light guide tip member 30, the wavelength conversion member 40, and the blocking member 70 are arranged in FIG. 1 (when the reflection member 60 is not provided).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Excitation light 10 Excitation light source 11 Light emitting element 12 Emitting part 13 Lens 20 Light guide 21 Output part 30 Light guide tip member 40 Wavelength conversion member 50 Reflective film 60 Reflective member 70 Blocking member

Claims (9)

An excitation light source that emits excitation light;
A light guide for propagating the excitation light, wherein the refractive index of the central part (core) of the cross section is higher than the refractive index of the peripheral part (cladding);
A wavelength converting member that absorbs the excitation light propagated by the light guide and converts the wavelength to emit light in a predetermined wavelength range;
A blocking member that blocks light emitted from the wavelength conversion member and at least a part of wavelengths of the excitation light;
A light-emitting device comprising:   The light-emitting device according to claim 1, wherein the shielding member has a lens shape.   The light emitting device according to claim 2, wherein the shielding member includes a diffusion member.   The light emitting device according to any one of claims 1 to 3, further comprising a reflecting member that reflects at least a part of the light emitted from the wavelength conversion member and the excitation light. The wavelength conversion member is composed of two or more layers,
The reflective member is sandwiched between layers of the wavelength converting member,
The light-emitting device according to claim 4.   The light-emitting device according to claim 4, wherein the reflection member reflects the excitation light.   The light-emitting device according to claim 4, wherein the reflection member reflects light having a shorter wavelength than the vicinity of the emission peak wavelength of the wavelength conversion member.   The light-emitting device according to claim 4, wherein the reflection member reflects light having a wavelength of about 420 nm or less. A light guide tip member is provided at an end of the light guide on the emission side, and a reflection film that reflects light in a predetermined wavelength region is formed on an end surface of the light guide tip member. The light emitting device according to claim 8.

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