JP4935215B2 - Light emitting device - Google Patents

Description

  The present invention relates to a light emitting device that can be used for a display device, a lighting fixture, a display, a backlight light source of a liquid crystal display, a projector device, a laser display, an endoscope, and the like, and in particular, a light emitting device using a semiconductor light emitting element and an optical fiber. About.

  Light emitting devices capable of emitting light of various wavelengths are used in illumination devices, projector devices, laser displays, endoscopes, and the like. Conventionally, fluorescent lamps, metal halide lamps, xenon lamps, and the like have been used as light sources for such light-emitting devices, and these lights are introduced into an optical fiber to form a light-emitting device. In recent years, methods using semiconductor light emitting elements such as light emitting diodes and laser diodes have been studied as an alternative to these light sources.

  For example, as an alternative to a lamp using a filament, light from a semiconductor light emitting element is transmitted to a disperser through a separator such as an optical fiber, and the light is dispersed in a desired pattern or the color of the light is changed. There has been proposed a lamp capable of performing (see, for example, Patent Document 1). Further, as an endoscope, one that emits white light using a blue laser diode and a phosphor has been proposed (for example, see Patent Document 2).

Special table 2003-515899 gazette JP-A-2005-328921

  The light emitting device as described above has a long life because the semiconductor light emitting element itself is not easily deteriorated in addition to being able to be downsized as compared with the conventional light emitting device. For this reason, there is also an advantage that troubles such as replacement are reduced. However, these light-emitting devices require further studies on optical characteristics such as light extraction efficiency and light distribution characteristics.

  For example, since the light emitting device described in Patent Document 1 diffuses light from a light source using a disperser, directivity is difficult to control. Furthermore, there is a problem that the light extraction efficiency is poor.

  In addition, the endoscope described in Patent Document 2 is provided with a metal film to disperse a phosphor in a high refractive index medium such as a transparent resin and provide it at the tip of an optical fiber, and to reflect light from the light source or the phosphor. The light extraction efficiency is improved by providing a reflective film made of However, since the resin and the metal have poor adhesion, it is difficult to stably hold the reflective film, and peeling may occur. In such a case, deterioration such as coloring of the metal in the peeling portion occurs, and the reflection efficiency is likely to be lowered due to the portion absorbing light, and as a result, the light extraction efficiency may be deteriorated.

  The present invention solves the above-described problems, and an object thereof is to provide a light-emitting device having a configuration capable of efficiently emitting light from a semiconductor light-emitting element to the outside.

In order to achieve the above object, a light-emitting device according to the present invention is attached to a semiconductor light-emitting element, a bendable light-guiding member that propagates light from the semiconductor light-emitting element, and an output-side end of the light-guiding member. A light emitting device having a reflective surface capable of reflecting light from a semiconductor element, wherein the optical component has a covering member that covers at least a part of the reflecting surface, and the covering member is silver A first layer having a surface, a part of the surface of the first layer, a gap in which the first layer is exposed, a second layer containing a metal different from silver, a first layer, a second layer, and a semiconductor And a third layer including a transmission member capable of transmitting light from the light-emitting element.

  Thereby, the light from the semiconductor light emitting element can be efficiently reflected by the optical component. In particular, high reflectivity can be maintained by using silver so as to have a high reflectivity and covering with a film that makes this silver difficult to change due to external factors. Therefore, it is possible to make it difficult to cause a change over time such as a decrease in reflectivity depending on the manufacturing process or the environment during use, and a light emitting device having excellent characteristics can be obtained.

  In the light-emitting device according to claim 2 of the present invention, the second layer is made of aluminum, nickel, titanium, tungsten, vanadium, platinum, rhodium, palladium, tantalum, gold, niobium, molybdenum, iridium, cobalt, chromium, copper It is preferable that at least one selected from the group consisting of hafnium, zinc and zirconium is included. Thereby, the adhesiveness of a 1st layer and a 3rd layer can be improved.

In the light emitting device according to claim 3 of the present invention, the third layer includes at least one selected from an oxide, a nitride, a fluoride, and a transparent resin. More specifically, the third layer is composed of SiO ₂ , Al ₂ O ₃ , SiN, ITO, Si ₃ N ₄ , SiON, AlN, AlON, In ₂ O ₃ , SnO ₂ , TiO ₂ , ZnO, MgF. Those containing at least one selected from ₂ are preferred. Thereby, a 1st layer and a 2nd layer can be protected, without reducing a reflectance.

  In the light-emitting device according to claim 5 of the present invention, the optical component includes a ferrule that holds the distal end portion of the light guide member, and a cap that protects the ferrule and the distal end portion of the light guide member. It is preferable to have a through-hole through which light emitted from passes and to have the covering member on the inner wall of the through-hole. Thereby, the light that has reached the optical component can be efficiently emitted to the outside.

  The light-emitting device according to claim 6 of the present invention preferably has a covering member at the tip of the ferrule. Thereby, it is possible to suppress the light from returning to the inside of the ferrule and to efficiently emit the light to the outside.

  In the light emitting device according to claim 7 of the present invention, it is preferable that the optical component has a wavelength conversion member that is excited by light from the semiconductor light emitting element and emits light of different wavelengths. As a result, the light from the semiconductor light emitting element can be efficiently propagated using the light guide member, and the propagated light can be converted into light of a desired wavelength, thereby reducing the loss of the converted light. , Can be discharged to the outside efficiently.

  With the light emitting device according to the present invention, the light emitted through the light guide member can be efficiently reflected by the covering member of the optical component provided at the tip of the light guide member. It becomes possible to discharge outside without lowering. In particular, since the reflectance of the first layer containing silver having a high reflectance can be suppressed without lowering the second layer and the third layer, and deterioration of the first layer can be suppressed, high light extraction efficiency can be achieved. Can be maintained.

  The best mode for carrying out the present invention will be described below with reference to the drawings. However, the form shown below illustrates the light emitting device for embodying the technical idea of the present invention, and the present invention does not limit the light emitting device to the following.

  Further, the present specification by no means specifies the members shown in the claims to the members of the embodiments. The dimensions, materials, shapes, relative arrangements, and the like of the components described in the embodiments are not intended to limit the scope of the present invention only to the description unless otherwise specified. It is just an example. It should be noted that the size and positional relationship of the members shown in each drawing may be exaggerated for clarity of explanation. Further, in the following description, the same name and reference sign indicate the same or the same members, and detailed description will be omitted as appropriate. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and the plurality of elements are shared by one member, and conversely, the function of one member is constituted by a plurality of members. It can also be realized by sharing. Hereinafter, the light emitting device according to this embodiment will be described with reference to the drawings.

<Embodiment 1>
FIG. 1A shows a light emitting device 100 according to Embodiment 1. FIG. FIG. 1B is an enlarged view of the optical component 110 used in the light emitting device of FIG. 1A. 1C is a diagram illustrating a configuration of the optical component 110 in FIG. 1B, and FIG. 1D is an enlarged view of a cap that configures the optical component.

  As shown in FIG. 1A, the light-emitting device according to Embodiment 1 is condensed with a light source 120 including a semiconductor light-emitting element 121 inside a package 122, a lens 140 that collects light from the light source 120 and collects the light. A connector 150 for introducing the light into the light guide member, a light guide member 130 connected to the connector 150, and an optical component 110 at the tip of the light guide member 130. As shown in FIGS. 1B and 1C, the optical component 110 includes a ferrule 112 attached to an end portion on the light exit side of the light guide member 130 and a flange 111 to which the ferrule 112 is fixed. And it has the cap 113 which coat | covers the front-end | tip part of the ferrule 112, and the cap 113 and the flange 111 are joined by welding etc.

  The tip of the cap 113 is provided with a through hole (opening) for emitting light, and the inner wall of the through hole serves as a reflection surface 113a for reflecting light. A translucent member 115 is provided in the through hole. The translucent member 115 is fixed to the through hole of the cap 113 by the joining member 114, and the light propagating through the light guide member 130 passes through the translucent member 115 and is emitted to the outside.

  The first embodiment is characterized in that a covering member 116A is provided on the reflection surface 113a of the cap 113. In particular, the covering member 116A includes a first layer 116A-1 containing silver, and a first layer 116A-1. A second layer 116A-2 that covers at least part of the surface of the layer and includes a metal different from silver, and a third layer 116A that covers the first layer and the second layer and includes a transmissive member that can transmit light from the semiconductor light emitting element. -3. By providing the covering member having such a configuration, it is possible to protect the first layer containing silver from moisture and the like, while preventing the high reflectivity from being impaired. Can be reflected.

(Optical parts)
In the first embodiment, the optical component is a member provided at the tip of the light guide member, and optical characteristics such as light distribution characteristics of light emitted by the optical component can be adjusted. In the present embodiment, only the mechanism for extracting light will be described, but it goes without saying that other members such as a CCD camera may be used in combination.

  Specifically, as shown in FIGS. 1B and 1C, the optical component includes a ferrule 112 attached to an end portion on the emission side of the light guide member 130 and a flange 111 to which the ferrule 112 is fixed. . And it has the cap 113 which coat | covers the front-end | tip part of the ferrule 112, and the cap 113 and the flange 111 are joined by welding etc.

  The tip of the cap 113 is provided with a through hole (opening) for emitting light, and the inner wall of the through hole serves as a reflection surface 113a for reflecting light. A translucent member 115 is provided in the opening. The translucent member 115 is fixed to the through hole of the cap 113 by the joining member 114, and the light propagating through the light guide member 130 passes through the translucent member 115 and is emitted to the outside.

(Coating member)
In Embodiment 1, the covering member is provided on a cap having a reflective surface among optical components provided at the front end of the light guide member for emitting light from the light source through the light guide member. The light from the light is efficiently reflected. Specifically, it is provided on at least a reflection surface to which light emitted from the light guide member hits, of the inner wall of the through hole provided in the cap. For example, as shown in FIG. 1D and FIG. 2, the covering member is provided only on the reflective surface that is the inner wall on the emission side in the through hole of the cap. Thereby, it is possible to reflect light efficiently. Furthermore, as shown in FIG. 4B, a covering member may be provided not only on the reflecting surface that is actually exposed to light in this way, but also on the inner wall of the through hole continuing from the reflecting surface. In particular, when a covering member is provided by sputtering or the like, when it is intended to be partially provided in a desired region, it is necessary to mask with a resist or the like, but when the optical component is very small and the cap diameter is small, It is difficult to mask the inner wall of the through hole. Therefore, the covering member can be provided on the entire surface (exposed surface) including the reflective surface by sputtering or the like without using a mask. Thereby, the covering member which continues from a reflective surface is provided also in the inner wall which a light does not hit in order to insert a ferrule among the through-holes of a cap, and also an outer wall, a front end surface, etc. As described above, even if the covering member is provided up to the portion where the light does not hit, the decrease in the reflectance is not directly suppressed. However, the mechanical strength can be supplemented, for example, it becomes difficult to peel off as compared with the case where the covering member is provided only on the reflecting surface. In addition, since the mask is not provided, the process can be shortened, and there is no adverse effect such as the mask member remaining. There is no problem even if the covering member formed other than the reflecting surface does not satisfy conditions such as a preferable film thickness of each layer as described later.

  The covering member includes a first layer having silver, a second layer that covers at least part of the surface of the first layer, and includes a metal different from silver, and covers the first layer and the second layer. And a third layer including a transmissive member capable of transmitting the light. By adopting such a configuration, even when the optical component is exposed to the external environment, it is possible to make the first layer, in particular, silver difficult to change, so that the light from the light source is absorbed by the optical component. Can be suppressed. Thus, a light emitting device with little loss of light from the light source can be obtained.

(Coating member: first layer)
In the first embodiment, the first layer of the covering member has silver. Silver alone may be used, or an alloy with aluminum, copper, titanium or the like may be used. This first layer is preferably provided on almost the entire surface (reflective surface) on which light emitted from the optical fiber strikes in the optical component. For example, in the case of the cap 113 as shown in FIG. 1D, the first layer 116A-1 is provided on substantially the entire reflective surface 113a. By doing in this way, light can be reflected efficiently. The film thickness of the first layer is sufficient if it does not transmit light. Specifically, the thickness is preferably 0.3 μm to 10 μm, more preferably 1 μm to 5 μm. The first layer is preferably formed with a substantially uniform film thickness.

(Coating member: second layer)
The second layer of the covering member covers at least a part of the surface of the first layer and contains a metal different from silver. Since the first layer is a layer containing silver, it is likely to be altered by moisture, impurities in the atmosphere, etc., and the reflectance is thereby lowered. Therefore, it is preferable to provide a layer for protecting the layer containing silver from the outside, but since silver does not have high adhesiveness to those protective layers, there is a problem that, after all, a gap is formed and the quality is changed from there. is there. Therefore, a second layer containing a metal different from silver is provided on the first layer as in the present invention, and the physical characteristics (or chemical characteristics) of the surface of the first layer are changed by the second layer. By doing so, the third layer can be provided with good adhesion.

  The second layer is preferably provided so as to cover a part of the first layer so as not to impair the high reflectance of the first layer. In this case, a part means that the surface of the first layer is covered with a low-density layer. That is, when the metal layer is thinly formed by sputtering or the like, the metal is sparsely adhered to the surface of the first layer, and the first layer is exposed from the gap between the second layers. Thus, the physical properties of the surface of the first layer can be changed without reducing the reflectivity of the first layer by covering the surface of the first layer with a sparse second layer rather than being completely covered. Can do. Or you may provide so that it may cover the whole instead of a part of 1st layer. In that case, it is preferable to provide a thin film to such an extent that the reflectance of the first layer is not lowered. Thereby, the effect similar to the above can be acquired. Thus, the region (part or whole surface) for providing the second layer can be appropriately selected in consideration of the composition of the first layer and the third layer.

  Further, regarding the film thickness, it is necessary to make it difficult to reduce the reflectance of the first layer, and it is preferable to make it extremely thin. These differ depending on the member to be used and also on the wavelength of the light source and the like, but are preferably about 1 to 20 inches, more preferably about 2 to 10 inches.

  The member of the second layer preferably has a member different from silver, and more preferably a member that does not reduce the reflectance of the first layer. The second layer controls the formation region and film thickness so as not to greatly reduce the reflectance of the first layer. However, the second layer has characteristics other than the optical characteristics, such as adhesion to the first layer and the third layer. In consideration, there are cases where it cannot be made too thin. Even in such a case, the reflectance with respect to the light from the light source and the light from the wavelength conversion member to be described later is about the same as the first layer or about 60% even when it is lowered. preferable. Alternatively, although it depends on the wavelength, the reflectance may be higher than that of the first layer.

  As described above, in the present invention, it is preferable to appropriately select a material for the second layer in consideration of optical characteristics such as reflectance, and the conductivity is not particularly limited. That is, in the present invention, the covering member is provided in an optical component that is separated from a light source including an electronic component such as a semiconductor light emitting element, and a cap or ferrule provided with a reflective surface among the optical component. There is no need to supply power. Therefore, even if it is an electroconductive thing or an insulating thing, the function as a reflection member should just be satisfied. However, considering the adhesion with the first layer, a material containing a metal is preferable. Specifically, aluminum, nickel, titanium, tungsten, vanadium, platinum, rhodium, palladium, tantalum, gold, niobium, molybdenum, iridium, cobalt, chromium, copper, hafnium, zinc, zirconium, or the like can be used. These may be used alone or in admixture of two or more. When using 2 or more types, you may provide simultaneously or may provide in another process.

(Coating member: third layer)
The third layer of the covering member includes a transmissive member that covers the first layer and the second layer and can transmit light from the semiconductor light emitting element. In particular, the light transmittance from the semiconductor light emitting device is preferably 70% or more. As a result, the light reflected by the first layer can be efficiently reflected.

  The third layer functions mainly as a protective layer that suppresses the alteration of the first layer. Accordingly, it is preferable to provide the first layer in a region covering almost the entire exposed region.

As the material of the third layer, it is preferable to use a translucent member such as oxide, nitride, fluoride, organic substance (resin), and specifically, SiO ₂ , Al ₂ O ₃ , SiN, ITO, Si _It is preferable to use 3N ₄ , SiON, AlN, AlON, In ₂ O ₃ , SnO ₂ , TiO ₂ , ZnO, MgF ₂ , silicone resin, epoxy resin, or the like. Moreover, these may be used independently and 2 or more types may be used.

  The film thickness of the third layer needs to be set to such an extent that light from the semiconductor light emitting element can be transmitted and moisture cannot easily enter from the outside. Specifically, it is preferably 0.005 μm to 0.5 μm, more preferably 0.01 μm to 0.3 μm.

(cap)
In Embodiment 1, the cap fitted to the ferrule provided at the tip of the optical fiber has a reflecting surface. And the front-end | tip part of a cap has a reflective surface, and a coating | coated member is provided in this reflective surface at least. Specifically, as shown in FIG. 1C, a cap 113 has a through hole (opening) at the tip, and the inner wall of the through hole serves as a reflection surface 113a. A coating member 116A is provided on the reflection surface 113a, and a light-transmissive member 115 is provided thereon. The translucent member 115 is joined by the joining member 114.

  The reflective surface 113a of the cap 113 is an inner wall of the through hole (opening) of the cap 113, and it is easy to fix the translucent member 115 by providing a step as shown in FIG. 1D. In FIG. 1D, the reflecting surface is a surface that is not inclined with respect to the light emission direction and is perpendicular to the light emitting direction. However, the present invention is not limited to this. For example, an inclined surface may be used so that light is easily reflected in the light emission direction. For example, a part of the reflecting surface 213a may be a curved surface as shown in FIG. In FIG. 2, the covering member 216 </ b> A is partially covered by the translucent member 215 and the bonding member 214, but has an uncovered region. That is, unlike FIG. 1D, it has a region where the covering member 216A is exposed. In such a case, the light distribution can be easily controlled by the angle of the reflecting surface 213a and the like, and more condensed light can be emitted. Even when the reflection surface 213a is exposed in this manner, the first layer 216A-1 containing silver is covered with the second layer 216A-2 and the third layer 216A-3, and thus deteriorates. Can be difficult.

  The shape of the cap is preferably such that the ferrule and the tip of the light guide member can be protected. For example, a cylindrical shape as shown in FIG. 1B is preferable. Thus, by not providing corners on the outer periphery, problems such as damage to the human body can be reduced when used as an endoscope or the like. Furthermore, it is preferable that the outer periphery including the flange is cylindrical. However, when a plurality of optical components are used, for example, in an illumination device, a quadrangular prism shape or the like may be used so that the optical component can be easily fixed.

The cap material is not particularly limited, but a material having high thermal conductivity is preferable. In particular, heat may be generated when light from a light source, light reflected by a covering member, or the like is irradiated onto a translucent member or a fluorescent member contained therein. In such a case, it is easy to cause alteration such as change in chromaticity or decrease in luminosity. Therefore, the cap material should be a member having a higher thermal conductivity than at least a translucent member or a fluorescent member. preferable. Specific examples of such materials include metals (stainless steel, copper, brass, kovar, aluminum, silver, etc.), alumina (Al ₂ O ₃ ), silicon carbide (SiC), CuW, Cu diamond, diamond, and the like. .

  The size and shape of the through hole (opening) of the cap are not particularly limited as long as light from the light guide member can be transmitted. A circular through hole as shown in FIG. 1B is preferable. Furthermore, the diameters of the through holes may be the same throughout, or as shown in FIG. 1C, a part substantially equal to the outer diameter of the ferrule and a part wider than that may be provided. Moreover, it is good also as a through-hole which spreads gradually toward an opening side, or becomes narrow gradually. Moreover, about the number of through-holes, although what provided one through-hole in FIG. 1B is illustrated, it is not restricted to this, You may provide two or more two or more. For example, as shown in FIG. 2, when a plurality of optical fibers 230 are used using a plurality of light sources 220, a plurality of through holes can be provided so that each light can be emitted independently.

(Translucent member)
In the first embodiment, the translucent member is disposed in the through hole (opening) of the cap, and protects the tip of the optical fiber. As a material to be used, a material that easily transmits light from a light source or a fluorescent member is preferable. Specifically, quartz glass, borosilicate glass, low-melting glass, silicone resin, epoxy resin, or the like is preferably used. Those having a certain degree of strength are preferable in order to function as protective members. For example, as shown in FIG. 1C, when a circular plate is first processed and formed so as to be bonded to a cap using a bonding member, the thickness of the translucent member is about 0.1 mm to 1.0 mm. Is preferable. The same applies to a lens-shaped translucent member 215 as shown in FIG. 2C. As the bonding member, it is preferable to use a material having high adhesiveness in consideration of the material of the cap and the translucent member. Furthermore, it is preferable to use a member that hardly absorbs light from the light source or the fluorescent member. Specifically, low-melting glass, quartz glass, borosilicate glass, silicone resin, epoxy resin, or the like can be used.

In addition to the method of forming a translucent member in a separate step and joining it to the cap,
As shown to FIG. 4A, it can also be set as the cap shape which can lock a translucent member, and can also be fixed mechanically. Alternatively, the translucent member is not formed in a separate process in a separate process, but after the cap is fitted to the ferrule, the translucent member before curing is potted and then cured, etc. But it can be provided.

  Moreover, the wavelength conversion member mentioned later can be mixed in this translucent member.

(Ferrule)
In the first embodiment, the ferrule is a member provided at the tip portion of the light guide member, and is joined so as to cover the periphery of the light guide member. By providing such a member at the tip of the light guide member, the tip portion can be easily processed.

  Specifically, as shown in FIG. 1C, the ferrule 112 is disposed so as to be covered with a cap 113.

As a material of the ferrule, a material having a high reflectance with respect to light from a light source and light from a fluorescent member described later is preferable. Thereby, the light reflected by the translucent member or the covering member can be made difficult to return to the inside of the ferrule. Moreover, a thing with high heat conductivity is preferable. In particular, heat may be generated when light from a light source, light reflected by a covering member, or the like is irradiated onto a translucent member or a fluorescent member contained therein. In such a case, the ferrule material is preferably a member having a higher thermal conductivity than at least a light-transmitting member or a fluorescent member because it is likely to cause alteration such as a change in chromaticity or a decrease in luminous intensity. Specific examples of such a material include aluminum, silver, platinum, alumina (Al ₂ O ₃ ), zirconia (ZrO ₂ ), diamond, and the like.

(Light guide member)
The light guide member may be any member that guides light from the light source to the optical component, and is configured to be able to bend while extending in the longitudinal direction. Thereby, light can be easily derived to a desired position. As such a light guide member, an optical fiber is preferably used.

  An optical fiber is configured by arranging a core having a high refractive index on the inside and a clad having a low refractive index on the outside. The shape of the end of the optical fiber on the light source side and / or the end on the optical component side is not particularly limited, and may be various shapes such as a flat surface, a convex lens, a concave lens, or a shape having at least partial irregularities. be able to. The optical fiber cross section is preferably circular, but is not limited thereto. The diameter of the optical fiber is not particularly limited, but for example, a fiber having a diameter of 3000 μm or less, 1000 μm or less, 400 μm or less, or 200 μm or less can be used. Specific examples include core / clad = 114/125 (μm), 72/80 (μm), and the like. The diameter of the optical fiber 130 is the average length in the cross section when the cross section is not circular. One end of the optical fiber is disposed on the light source side, and the other end is disposed on the translucent member side.

  In addition to the optical fiber as described above, it is a kind of optical fiber, such as a holey fiber having a structure in which a portion where light propagates is surrounded by a hole, a liquid fiber that is a special fiber containing liquid, and the like. Can be used.

(Wavelength conversion member)
In the translucent member, a fluorescent member that emits light having a different wavelength by absorbing at least a part of light from the semiconductor light emitting element may be included as a wavelength conversion member. The fluorescent member is preferably used by being mixed in a translucent member such as glass or resin. At this time, in addition to the fluorescent member, a diffusing agent or the like can be used together. Such a wavelength conversion member can be provided not on an optical component such as a cap but on other members. For example, it can also be provided in the vicinity of the semiconductor light emitting element of the light source. However, in order to efficiently introduce light into the light guide member, it is preferable to use a laser diode as the semiconductor light emitting element. In this case, if a wavelength conversion member is provided in the vicinity of the light source, it is likely to be deteriorated. Is preferred.

  As the fluorescent member, it is more efficient to convert the light from the semiconductor light emitting element into a longer wavelength. The fluorescent member 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 material are mixed, or contains one type of fluorescent material, etc. Two or more single layers may be stacked, or two or more single layers each of which is mixed with two or more kinds of fluorescent substances may be stacked.

  Any fluorescent member may be used as long as it absorbs light from a semiconductor light emitting device 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 further 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 composition 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% of Al, 5 to 50 mol% of AlN, 0.1 to 20 mol% of rare earth oxide or transition metal oxide, and a base material of an oxynitride glass in which the total of five components is 100 mol% 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.

(Semiconductor light emitting device)
In Embodiment 1, it is preferable to use a laser diode as the semiconductor light emitting element. Thereby, light can be efficiently introduced into the light guide member.

A semiconductor light emitting device having an arbitrary wavelength can be selected. For example, as blue and green light emitting elements, those using ZnSe or a nitride semiconductor (In _X Al _Y Ga _1- XYN, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1) are used. it can. As the red light emitting element, GaAs, InP, or the like can be used. Furthermore, a semiconductor light emitting element made of a material other than this can also be used. The composition, emission color, size, number, and the like of the light emitting element to be used can be appropriately selected according to the purpose.

In the case of a light-emitting device having a fluorescent material, a nitride semiconductor (In _X Al _Y Ga _1- XYN, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1) is preferable. Various emission wavelengths can be selected depending on the material of the semiconductor layer and the degree of mixed crystal.

  Further, a light-emitting element that outputs not only light in the visible light region but also ultraviolet rays and infrared rays can be obtained. In addition to the semiconductor light emitting element, a light receiving element, a protective element (for example, a Zener diode or a capacitor) that protects the semiconductor element from destruction due to overvoltage, or a combination thereof can be mounted.

<Embodiment 2>
In the second embodiment, the ferrule 112 is provided with a reflecting member in addition to the cap 113 serving as a base. Specifically, as shown in FIG. 3A, a covering member 316A is provided on the reflection surface 313a of the cap 313. In particular, the covering member 316A includes a first layer 316A-1 containing silver and A second layer 316A-2 covering at least a part of the surface of the first layer and containing a metal different from silver; a first layer including a transmissive member covering the first layer and the second layer and capable of transmitting light from the semiconductor light emitting device; 3 layers 316A-3. By providing the covering member having such a configuration, it is possible to protect silver from moisture and the like, while preventing the high reflectivity from being impaired. Therefore, light from the semiconductor light emitting element can be efficiently reflected. .

(Ferrule)
In the second embodiment, light can be efficiently emitted from the tip of the light guide member by providing the ferrule with a covering member in addition to the cap.

  Specifically, as shown in FIG. 3A, the ferrule 312 is disposed so as to be covered with a cap 313, and a translucent member 315 is provided at the tip of the ferrule 312. The light propagating through the light guide member 330 is reflected by the translucent member provided at the tip of the light guide member, and part of the light is reflected by the reflective surface of the inner wall of the cap and emitted to the outside. Light returns toward the tip of the ferrule. For this reason, the tip of the ferrule 312 is the reflecting surface 312a, and the covering member 316B is also provided on this surface, so that light can be prevented from entering the ferrule.

As the ferrule material, aluminum, silver, platinum, alumina (Al ₂ O ₃ ), zirconia (ZrO ₂ ), and the like mentioned in the first embodiment can be used, and members having a lower reflectance than these can also be used. . For example, stainless steel, nickel, silicon carbide (SiC), diamond, borosilicate glass, or the like can be used. Rather than reflecting light only with a ferrule, providing a coating member to increase the reflectance increases the choice of materials compared to the first embodiment.

  When the covering member is provided on the ferrule, it is preferable to provide the covering member at least on the end surface located at the tip of the light guide member. Specifically, in FIG. 4A, by providing a covering member 416B on the reflecting surface 412a at the tip of the ferrule 412, light can be efficiently reflected. In addition, as shown in FIG. 3B, by providing the covering member also on the side surface (outer periphery) continuous from the reflecting surface 312a, the contact area between the covering member and the ferrule is increased, so that it is difficult to peel off. In particular, the first layer can be easily protected.

  Moreover, among the covering members, the first layer needs to be provided so as not to cover the end face of the light guide member, but the second layer and the third layer may be provided on the end face of the light guide member. Absent.

  The covering member provided on the ferrule and the covering member provided on the cap are preferably made of the same member, so that the reflection function can be easily made uniform and the light distribution characteristics and the like can be easily controlled. Moreover, when using a different member, the light distribution characteristic can be adjusted by making the reflectance of the covering member provided on the ferrule lower or higher than the reflectance of the covering member provided on the cap. Thus, the material of the covering member can be appropriately selected according to the purpose and application.

  FIG. 1A is a diagram illustrating an example of a light emitting device according to Example 1 of the invention.

  In order to connect the aspherical lens 140 for condensing the light from the light source 120 on which a gallium nitride based semiconductor laser diode is mounted as the semiconductor light emitting element 121 in the metal package 122 to the optical fiber 130. Connector 150. As the light guide member 130, an SI type optical fiber (114 (μm: core diameter) / 125 (μm: clad diameter)) made of quartz was used. Furthermore, the optical fiber 130 is joined to the connector, and the optical component 110 is joined to the end of the optical fiber 130 on the emission side.

  1B and 1C are diagrams illustrating the configuration of the optical component 110. An optical fiber 130 is held by a ferrule 112 and a flange 111 made of nickel. The ferrule has a length of 3 mm and an outer diameter of 0.7 mm, and a through-hole having a diameter of 126 mm is formed at the center thereof. The flange has a length of 4 mm as a whole, the portion holding the ferrule has a length of 1.5 mm, an outer diameter of φ1.25 mm, and a through-hole of 0.7 mm is formed in the center. . The portion that holds only the optical fiber has a length of 2.5 mm and an outer diameter of φ1.0 mm, and a through hole of φ0.5 mm is formed at the center. The ferrule is joined by press fitting so as to fit in the through hole of the flange. Then, the optical fiber 130 is passed through the integrated flange and ferrule through-hole, and bonded using an epoxy resin. At this time, polishing is performed after the joining so that the end face of the optical fiber and the end face of the ferrule are flush with each other.

  The cap 113 is made of SUS304, has a length of 1.1 mm, an outer diameter of φ1.25 mm, and is formed around a through hole of φ0.71 mm to hold the ferrule. A range of 0.1 mm from the end face on the emission side is a through hole with an inner diameter of φ1.0 mm, and the inner wall of this portion becomes the reflecting surface 113a. The reflection surface 113a is formed at an angle parallel to the through hole.

FIG. 1D is an enlarged view of the cap 113. A reflective surface 113a is formed inside the through hole of the cap, and a covering member 116A is provided on the entire surface of the cap including the reflective surface. The first layer 116A-1 of the covering member is made of silver and has a film thickness of 40000 mm. Silver is provided by a plating method and is formed on the entire reflecting surface 113a. On the first layer, aluminum is provided with a thickness of 5 mm by sputtering. Furthermore, SiO ₂ is provided as a third layer with a film thickness of 100 mm by sputtering.

Thus, the cap 113 provided with the covering member 116A is made of borosilicate glass, a circular flat plate-shaped translucent member 115 having a diameter of 0.9 mm and a thickness of 0.45 mm, and low melting point glass as a joining member. Use to join. Note that in the light-transmissive member 115, as previously wavelength conversion member _Y 3 _Al 5 _O 2: Ce _{and, Lu 3 Al 5 O 12:} Ce of 1: phosphor contained in 8 ratio of 12 wt% Contained. The ferrule is connected so as to fit into the through hole of the cap 113 formed in this way. Here, the cap and the flange are joined by welding.

  The light source of the light emitting device obtained as described above is caused to emit light, and white light is emitted from the optical component. The obtained white light has initial color characteristics of x = 0.30, y = 0.36, and a luminous flux of 39.3 lm, and the characteristics after the sulfidation acceleration test using sodium sulfide have a color tone of x = x = 0.30. It is 0.29, y = 0.36, and the luminous intensity is 39.0 lm. This is because the reference silver-plated single layer film has a light flux of x = 0.29, y = 0.35, and luminous intensity of 36.5 lm. It can be seen that a reflective film resistant to deterioration is formed.

  In the second embodiment, the same procedure as in the first embodiment is performed except that the covering member is provided on the ferrule.

  A ferrule is attached to the end portion on the emission side of the optical fiber, and a resist is provided on the entire end face. The resist is made effective by heating at about 90 ° C. for about 30 minutes. Next, the resist provided on the end face of the optical fiber is exposed by making ultraviolet light incident from the side where the ferrule of the optical fiber is not attached. The resist can be left only on the end face of the optical fiber by heating the ferrule after exposure and washing with alkali.

  A covering member is provided for the ferrule and the optical fiber in such a state. The first layer of the covering member is silver having a thickness of 50000 mm. Silver is provided by a sputtering method and is formed on the entire outer periphery of the ferrule. Thereafter, the resist provided as described above is removed by ultrasonic cleaning with acetone and ultrapure water so that the end face of the optical fiber is exposed.

Next, aluminum is provided on the first layer and on the end face of the optical fiber with a thickness of 5 mm by sputtering. Further thereon, a SiO ₂ film having a thickness of 100 mm is provided as a third layer by sputtering.

  The light source of the light emitting device obtained as described above is caused to emit light, and white light is emitted from the optical component. As in Example 1, no deterioration was observed in the sulfidation accelerated test, and a reflective film resistant to deterioration was formed.

  The light-emitting device according to the present invention can efficiently reflect light from a semiconductor light-emitting element, and thus is a light-emitting device that has excellent light extraction efficiency. Various display devices, lighting fixtures, displays, and backlights for liquid crystal displays It can also be used for a light source, an image reading device in a facsimile, a copier, a scanner, a projector device, a laser display, an endoscope, and the like.

FIG. 1A is a diagram showing an example of a light emitting device according to the present invention. 1B is a perspective view of an optical component used in the light emitting device of FIG. 1A. FIG. 1C is a diagram illustrating a configuration of the optical component in FIG. 1B. FIG. 1D is an enlarged view of a part of the optical component of FIG. 1C. FIG. 2A is a diagram showing an example of a light emitting device according to the present invention. FIG. 2B is a perspective view of an optical component used in the light emitting device of FIG. 2A. 2C is a cross-sectional view of the optical component of FIG. 2B. FIG. 2D is an enlarged view of a part of the optical component of FIG. 2C. FIG. 3A is a diagram showing a configuration of an optical component of the light emitting device according to the present invention. FIG. 3B is an enlarged view of a part of the optical component of FIG. 3A. FIG. 4A is a diagram showing a configuration of an optical component of the light emitting device according to the present invention. FIG. 4B is an enlarged view of a part of the optical component of FIG. 4A.

Explanation of symbols

100, 200... Light emitting device 110, 210, 310, 410 ... Optical component 120, 220 ... Light source 130, 230, 330, 430 ... Light guide member (optical fiber)
140 ... lens 150 ... connectors 111, 211, 311, 411 ... flanges 112, 212, 312, 412 ... ferrules 312a, 412a ... reflecting surfaces 113, 213, 313, 413 of the ferrules .... Caps 113a, 213a, 313a, 413a ... Reflecting surfaces 114, 214, 314 of the caps ... Joining members 115, 215, 315, 415 ... Translucent members 116A, 216A, 316B, 416A, 416B ... Coating members 116A-1, 216A-1, 316B-1, 416A-1 ... First layer 116A-2, 216A-2, 316B-2, 416A-2 of coating member Second layer 116A-3, 216A-3, 316B-3, 416A-3 ... Third layer 121 of covering member ... Semiconductor Element 122 ... package

Claims (8)

A semiconductor light emitting device;
A bendable light guide member for propagating light from the semiconductor light emitting element;
An optical component attached to an end of the light guide member on the emission side and having a reflective surface capable of reflecting light from the semiconductor element;
A light emitting device comprising:
The optical component has a covering member that covers at least a part of the reflecting surface;
The covering member includes a first layer having silver;
A second layer that covers a part of the surface of the first layer, has a gap in which the first layer is exposed, and includes a metal different from silver;
A third layer that covers the first layer and the second layer and includes a transmissive member capable of transmitting light from the semiconductor light emitting element;
A light emitting device characterized by comprising: The second layer is selected from aluminum, nickel, titanium, tungsten, vanadium, platinum, rhodium, palladium, tantalum, gold, niobium, molybdenum, iridium, cobalt, chromium, copper, hafnium, zinc, zirconium. The light emitting device according to claim 1, comprising at least one. The light emitting device according to claim 1, wherein the third layer includes at least one selected from an oxide, a nitride, a fluoride, and a transparent resin. The third layer is selected from SiO ₂ , Al ₂ O ₃ , SiN, ITO, Si ₃ N ₄ , SiON, AlN, AlON, In ₂ O ₃ , SnO ₂ , TiO ₂ , ZnO, and MgF _2. The light emitting device according to claim 3, comprising at least one of the following. The optical component includes a ferrule for holding the leading end portion of the optical fiber, and a cap for protecting the tip of the ferrule and the optical fiber, the caps, the light emitted from the optical fiber passes The light-emitting device according to claim 1, further comprising: a through-hole that has a through-hole, and the covering member provided on an inner wall of the through-hole. The light-emitting device according to claim 5, wherein the covering member is provided at a tip portion of the ferrule. The light emitting device according to claim 1, wherein the optical component includes a fluorescent member that is excited by light from the semiconductor light emitting element and emits light of different wavelengths. The light emitting device according to claim 1, wherein the translucent member is bonded to the covering member.

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