JP5076916B2 - Light emitting device - Google Patents

Description

  The present invention relates to a light emitting device including a light emitting element and a wavelength conversion member.

  Conventionally, fluorescent lamps, metal halide lamps, xenon lamps, and the like have been used as light sources of light emitting devices. In recent years, the use of light emitting elements such as light emitting diodes and laser diodes has been studied as an alternative to these light sources.

  A schematic cross-sectional view of a conventional light emitting device is shown in FIG. For example, as shown in FIG. 20, a light emitting device 200 that emits white light by using a blue laser diode 220 as a light source and converting the wavelength using a phosphor composition 240 has been proposed (see, for example, Patent Document 1). .

Japanese Patent Laid-Open No. 2005-20010

However, in the above light emitting device, the following points have not been considered.
In the light emitting device of Patent Document 1, the laser light emission direction of the laser diode 220 and the light emission direction from the phosphor composition 240 are substantially the same. For this reason, there is a possibility that light from the laser diode 220 passes through the phosphor composition 240 and is emitted to the outside, so that there is a risk that the human body is directly irradiated with ultraviolet rays, laser light, or the like. In the light emitting device of Patent Document 1, since the phosphor composition 240 is disposed at a position where the light from the laser diode 220 is directly incident, the phosphor composition 240 is deteriorated by the heat caused by the light. There is a problem that desired light cannot be emitted to the outside, or in some cases, the phosphor composition 240 is discolored and cannot be used as a light emitting device.

  The present invention has been made to solve the above-described problems, and provides a light-emitting device having a configuration capable of emitting light with low risk and an object of providing a long-life light-emitting device. And

  A light emitting device according to the present invention includes a base having a recess having a bottom surface and an inner wall, a semiconductor laser element provided in the recess, a diffusion member provided in the recess and diffusing light of the semiconductor laser element, and a semiconductor laser A wavelength conversion member that absorbs light of the element and converts it into light of a different wavelength, the semiconductor laser element is disposed so that the optical axis faces the inner wall of the recess, and the diffusion member is light of the semiconductor laser element It arrange | positions on an axis | shaft and a wavelength conversion member is arrange | positioned in the opening direction of a recessed part.

  According to such a configuration, it is possible to suppress laser light from being directly emitted to the outside. In addition, the deterioration of the wavelength conversion member due to light from the semiconductor laser element can be suppressed.

  Moreover, it is preferable that the wavelength conversion member is irradiated with light from the diffusion member and / or reflected light from the inner wall. According to this configuration, it is possible to suppress deterioration of the wavelength conversion member due to light from the semiconductor laser element.

  Moreover, the wavelength conversion member may be fixed to the outer peripheral surface of the recess opening so as to cover the recess. According to such a configuration, it is possible to emit light with low risk while suppressing leakage of laser light to the outside.

  Moreover, it is fixed so that a recessed part may be covered, it has a reflector which has a through-hole in the opening direction of a recessed part, and the wavelength conversion member may be arrange | positioned so that a through-hole may be plugged up. According to such a configuration, it is possible to emit light with low risk while suppressing leakage of laser light to the outside.

  Further, the wavelength conversion member may be in contact with a part of the diffusing member. According to this configuration, it is possible to suppress deterioration of the wavelength conversion member due to light from the semiconductor laser element.

  Moreover, you may provide the 2nd diffusion member in the opening direction of the recessed part. According to such a configuration, it is possible to emit light with low risk while suppressing leakage of laser light to the outside.

  A light emitting device according to the present invention includes a pedestal, a semiconductor laser element fixed on the pedestal, a diffusion member fixed on the pedestal and diffusing light of the semiconductor laser element, and the semiconductor laser element and the diffusion member. A cap that is fixed to the pedestal so as to cover the substrate and that has an opening in a part thereof, and a wavelength conversion member that absorbs the light of the semiconductor laser element and converts it into light of a different wavelength. Arranged so that the axis faces the inner surface of the cap, the diffusing member is arranged on the optical axis of the semiconductor laser element, the wavelength converting member is arranged in the opening direction of the cap, and from the light from the diffusing member and the inner surface of the cap The wavelength conversion member is irradiated with the reflected light. According to such a configuration, it is possible to suppress laser light from being directly emitted to the outside. In addition, the deterioration of the wavelength conversion member due to light from the semiconductor laser element can be suppressed.

  The diffusion member may contain a filler in glass or resin. According to this configuration, it is possible to suppress deterioration of the wavelength conversion member due to light from the semiconductor laser element.

  The diffusing member is made of a material that reflects light from the semiconductor laser element, and may have an inclined surface that is inclined or curved with respect to the optical axis of the semiconductor laser element. According to this configuration, it is possible to suppress deterioration of the wavelength conversion member due to light from the semiconductor laser element.

  The inclined surface may have irregularities. According to this configuration, it is possible to suppress deterioration of the wavelength conversion member due to light from the semiconductor laser element.

  ADVANTAGE OF THE INVENTION According to this invention, it has a structure excellent in safety | security and can provide a long-life light-emitting device.

  Hereinafter, a light-emitting device of the present invention will be described with reference to the drawings. However, the light-emitting device described below is for embodying the technical idea of the present invention, and the present invention is not limited to the following. Unless otherwise specified, the dimensions, materials, shapes, relative arrangements, and the like of the constituent members are not merely intended to limit the scope of the present invention, but are merely illustrative examples. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation. Furthermore, each element which comprises this invention can also comprise a some element by one member, and conversely, one element can also be comprised by a plurality of members.

<Embodiment 1>
FIG. 1 is a plan view schematically showing a light emitting device according to Embodiment 1 of the present invention. FIG. 2 is a schematic cross-sectional view taken along the line II-II ′ of FIG.

The light emitting device according to the present embodiment mainly includes a base 110, a semiconductor laser element 120, a diffusion member 130, and a wavelength conversion member 140.
The base 110 is a thin rectangular parallelepiped having a substantially square plane (upper surface), and has a recess 111 having a bottom surface 112 and an inner wall 113 at a position offset from the central portion in the outer peripheral direction. A semiconductor laser element 120 and a diffusing member 130 are provided in the recess 111 of the base 110.
Specifically, the semiconductor laser element 120 and the diffusion member 130 are fixed to the bottom surface 112 of the recess 111. The semiconductor laser element 120 is disposed so that the optical axis faces the inner wall 113 of the recess 111. The diffusing member 130 is disposed so as to be positioned on the optical axis of the semiconductor laser element 120.

The wavelength conversion member 140 is disposed in the opening direction of the recess 111 of the base 110. Examples of the wavelength conversion member 140 include those obtained by dispersing phosphor particles, which are a kind of wavelength conversion material, in a translucent member.
In the light emitting device according to the present embodiment, reflector 150 is fixed so as to cover concave portion 111 of base 110. The reflector 150 has a through hole 155 that penetrates in the opening direction of the recess 111. And the wavelength conversion member 140 mentioned above is arrange | positioned so that this through-hole 155 may be plugged up. In the present invention, the form in which the through hole 155 is closed with the wavelength conversion member 140 is a form in which the through hole 155 is covered with the wavelength conversion member 140 from the upper surface or the lower surface of the reflector 150, or the wavelength conversion member 140 is fitted into the through hole 155. Can be used.

  With the configuration as described above, it is possible to suppress the light emitted from the semiconductor laser element 120 from being directly emitted to the outside, and to suppress the deterioration of the wavelength conversion member. That is, in the present embodiment, since the optical axis of the semiconductor laser element 120 is arranged so as to face the inner wall 113 of the recess 111, the light from the semiconductor laser element 120 is not directly emitted to the outside, but the inner wall. 113 is reflected. Further, by disposing the diffusing member 130 on the optical axis of the semiconductor laser element 120, at least a part of the light emitted from the semiconductor laser element 120 is diffused by the diffusing member 130 and the traveling direction is changed. Therefore, the light from the semiconductor laser element 120 is not directly irradiated onto the wavelength conversion member 140 but is irradiated with the light from the diffusion member 130 and / or the reflected light from the inner wall 113 of the recess 111.

  Hereinafter, each member which comprises the light-emitting device of this invention is demonstrated.

(Base)
The base 110 can mount the semiconductor laser element 120, functions as a support for fixing and holding the lead electrode to which the semiconductor laser element 120 is connected, and also has a function of protecting the semiconductor laser element 120 from the external environment.

In the present embodiment, the base 110 is made of a metal or alloy such as copper, iron, cobalt, nickel, gold, aluminum, brass, tungsten, molybdenum, kovar, stainless steel, CuW, or CuMo. Is preferred. _{Further, Al 2 O 3, SiC,} AlN, may be formed using a ceramic such as diamond.
Further, a reflective film made of Ag, Al, or the like may be formed on the surface of the base 110. Thereby, the light extraction efficiency can be improved.

The shape of the base 110 is not particularly limited, and may be any shape such as, for example, a cylinder, an elliptical column, a sphere, an oval, a polygonal column, or a shape similar to these, but the semiconductor laser element 120 and the diffusion member In order to arrange 130, it is preferable to have a recess 111 on one side, that is, the front side. The shape of the recess 111 is not particularly limited, and has a bottom surface 112 and an inner wall 113, and the region in the recess 111 is a cylinder, an elliptical column, a polygonal column, an inverted truncated cone, an inverted elliptical truncated cone, What forms an inverted polygon frustum shape etc. is preferable. The size of the recess 111 is suitably larger than the total occupied area of the semiconductor laser element 120 and the diffusion member 130.
In the light emitting device according to the present embodiment, since the wavelength conversion member 140 is disposed in the opening direction of the recess 111, the recess 111 has a size that allows at least the semiconductor laser element 120 and the diffusion member 130 to be disposed. If it is. Therefore, compared with the case where the wavelength conversion member 140 is arranged at intervals in the optical axis direction of the semiconductor laser element 120 so that the density of light applied to the wavelength conversion member 140 can be sufficiently reduced, the light emitting device is smaller. Is possible.
The angle of the inner wall 113 of the recess 111 is not particularly limited, and can be appropriately adjusted depending on the performance of the semiconductor laser element 120 and the diffusion member 130 to be used, the characteristics of the light emitting device to be obtained, and the like.

(Semiconductor laser element)
The semiconductor laser element 120 is disposed in the recess 111 of the base 110. The position where the semiconductor laser element 120 is fixed in the recess 111 is not particularly limited, and can be fixed to, for example, the bottom surface 112 or the inner wall 113 of the recess 111 or the bottom surface of a reflector described later. Further, the semiconductor laser element 120 is arranged so that the optical axis faces the inner wall 113 or the bottom surface 112 of the recess 111.

  The semiconductor laser element 120 is formed by forming a semiconductor such as GaAlN, ZnS, ZnSe, SiC, GaP, GaAlAs, AlN, InN, AlInGaP, InGaN, GaN, or AlInGaN on a substrate as a light emitting layer. Examples of the semiconductor structure include a homostructure, a heterostructure, or a double heterostructure having a MIS junction, a PIN junction, or a PN junction. Various emission wavelengths can be selected from ultraviolet light to infrared light depending on the material of the semiconductor layer and the degree of mixed crystal. The light emitting layer may have a single quantum well structure or a multiple quantum well structure which is a thin film in which a quantum effect is generated.

  When considering use outdoors, it is preferable to use a gallium nitride-based compound semiconductor as a semiconductor material capable of forming a high-luminance light-emitting element. In red, gallium-aluminum-arsenic-based semiconductors and aluminum-indium- Although it is preferable to use a gallium / phosphorus-based semiconductor, various semiconductors can be used depending on the application.

  When a gallium nitride compound semiconductor is used, a material such as sapphire, spinel, SiC, Si, ZnO, or GaN single crystal is used for the semiconductor substrate. In order to form gallium nitride with good crystallinity with high productivity, it is preferable to use a GaN single crystal substrate.

  As the semiconductor laser element 120, one having an emission peak wavelength at 300 nm to 500 nm can be used, but one having an emission peak wavelength at 400 nm to 470 nm is preferable. For example, one having an emission peak wavelength near 445 nm can be used.

  Since the semiconductor laser element has a higher light density than a light emitting diode or the like, the luminance as a light emitting device is easily improved by using the semiconductor laser element, but the wavelength conversion member 140 generates heat locally because the light density is high. , Easy to deteriorate and discolor. The present invention is particularly effective when a semiconductor laser element is used as the light source because the adverse effect of the heat on the wavelength conversion member 140 and peripheral members can be greatly reduced.

(Diffusion member)
The diffusing member 130 is not particularly limited as long as it diffuses the light from the semiconductor laser element 120. Further, not only diffusion but also reflection is not particularly limited.
The diffusing member 130 is disposed at least in the concave portion 111 of the base 110 and on the optical axis from the semiconductor laser element 120. For example, it can arrange | position to the bottom face 112 of the recessed part 111 of the base 110, the inner wall 113, or the bottom face of the reflector mentioned later. In the light emitting device according to the present embodiment, diffusion member 130 is fixed to bottom surface 112 of recess 111 of base 110.
By providing such a diffusion member 130, the light from the semiconductor laser element 120 enters the wavelength conversion member 140 through the diffusion member 130. Thereby, the concentration of light on the wavelength conversion member 140 can be reduced, and deterioration of the wavelength conversion member 140 can be reduced. In addition, the chromaticity variation of the light emitting device can be suppressed by the light diffusing action of the diffusing member 130.

As an example of the diffusing member 130, a material obtained by dispersing a light diffusing substance in a base material of a light-transmitting organic material or inorganic material can be given. As the organic material, an epoxy resin and a silicone resin are preferable, and as the inorganic material, glass is preferable. In addition, an inorganic material is preferable from the viewpoint of heat resistance. As the light diffusing substance, silicon carbide, silicon dioxide, barium sulfate, metal oxides such as zirconia, aluminum oxide, and titanium oxide, or air bubbles and glass with a vacuum inside (hollow filler) are preferable. Examples of the shape of the diffusing member 130 include a column, a cone, a frustum, a hemisphere, and a plano-convex shape.
The light diffusing substance may have various structures such as a hexagonal cubic shape, a spindle shape, a crushed shape, a rod shape such as a needle shape or a column shape. The particle size of the light diffusing substance is preferably larger than the emission wavelength of the semiconductor laser element 120. On the other hand, the smaller the particle size of the light diffusing substance, the higher the diffusing effect, so that the light and color unevenness that are uniformly irradiated to the wavelength conversion member 140 can be suppressed. Note that the shape, size, content, and the like of the light diffusing substance can be appropriately adjusted depending on the base material to be used, the performance of the semiconductor laser element 120, the characteristics of the light emitting device to be obtained, and the like. For example, in order to reduce chromaticity variation, it is possible to increase the content of the light diffusing substance as the distance from the semiconductor laser element 120 increases.
Further, as the diffusing member 130, a light guide plate or the like can be used in addition to the above-described light transmissive base material in which a light diffusing substance is dispersed.

(Reflective member)
The diffusing member 130 can be provided with a reflecting member 190. FIG. 3 is a plan view schematically showing an arrangement example of the reflecting member 190. FIG. 4 is a cross-sectional view schematically showing an arrangement example of the reflecting member 190.
The reflecting member 190 reflects the light emitted from the diffusing member 130. The reflecting member 190 is preferably provided on at least a part of the side surface of the diffusing member 130 other than the light receiving side which is the surface facing the semiconductor laser element 120. Thereby, the light emitted from the diffusing member 130 toward the inner wall 113 can be efficiently reflected.
Examples of the diffusion member 130 include a metal thin film or a dielectric multilayer film.
The metal thin film is preferably a member that reflects light emitted from the semiconductor laser element 120 and light emitted from the wavelength conversion member 140 (for example, a member that reflects light having a wavelength in the range of 350 nm to 800 nm). Further, a member that makes the amount of reflection of light of each wavelength substantially constant is preferable. Specifically, metals such as Ag, Au, Al, Ni, In, and Pd, alloys such as In—Ag and Au—Ag, and the like are preferable.
The dielectric multilayer film is composed of a dielectric multilayer film or the like. For example, it is a so-called wavelength-selective film that can transmit light emitted from the semiconductor laser element 120 but cannot transmit light having a wavelength converted by the wavelength conversion member 140. Examples of the dielectric multilayer film include AlN, SiO ₂ , TiO ₂ , Ta ₂ O ₅ , SiO, Al ₂ O ₃ , Ti ₃ O ₅ , Ti ₂ O ₃ , TiO, Nb ₂ O ₅ , CeO ₅ , ZnS. And a multilayer film composed of MgF ₂ or the like. Such a film can also be provided on the light receiving side, which is the surface facing the semiconductor laser element 120. Thereby, it is possible to prevent the light whose wavelength is converted by the wavelength conversion member 140 and returning to the diffusion member 130 from traveling to the semiconductor laser element 120.

(Wavelength conversion member)
The wavelength conversion member 140 absorbs a part of the light from the semiconductor laser element 120 and emits light having a wavelength different from that, thereby obtaining light emission of a desired color tone. That is, mixed color light of the light of the semiconductor laser element 120 and the light whose wavelength is converted by the wavelength conversion member 140 can be extracted to the outside. As an example of the wavelength conversion member 140, a material in which a translucent member such as a transparent resin or an inorganic member is used as a base material, and a phosphor as a wavelength conversion material is dispersed therein.

  In the present embodiment, the wavelength conversion member 140 is disposed in the opening direction of the recess 111 of the base 110. The light emitted from the semiconductor laser element 120 has the highest intensity in a region matching the optical axis. Therefore, it is preferable to provide the wavelength conversion member 140 at a position different from the optical axis of the semiconductor laser element 120. Thereby, deterioration of the wavelength conversion member 140 due to light from the semiconductor laser element 120 can be suppressed.

The wavelength conversion member 140 can obtain a desired wavelength by selecting one according to necessity. A plurality of types of wavelength conversion members 140 may exist.
For example, white light can be obtained as follows by using a phosphor as the wavelength conversion material to be contained in the translucent member. The first method excites a phosphor emitting yellow light with blue light emitted from the semiconductor laser element 120 in the short wavelength side region of visible light. As a result, the yellow light partially converted in wavelength and the blue light that is not converted are mixed, and are emitted as white light by two colors having a complementary color relationship. In the second method, R, G, and B phosphors are excited by light in the short wavelength region from ultraviolet to visible light emitted from the semiconductor laser element 120. The wavelength-converted three-color light is mixed and emitted as white light.

Representative phosphors capable of realizing the above functions include cadmium zinc sulfide attached with copper and YAG phosphors and LAG phosphors attached with cerium. In particular, (Re _1-x Sm _x ) ₃ (Al _1-y Ga _y ) ₅ O ₁₂ : Ce (0 ≦ x <1, 0 ≦ y ≦ 1, in the case of high brightness and long time use, provided that Re Is at least one element selected from the group consisting of Y, Gd, La, and Lu. The YAG, LAG, BAM, BAM: Mn, CCA, SCA, (Ca, Sr) 2 Si 5 N 8: Eu and CaAlSiN _3: phosphor containing at least one selected from the group consisting of Eu can be used. By combining the excitation light from the light source and the fluorescent material with good wavelength conversion efficiency in this excitation light, it is possible to obtain a light emitting device with high light emission output, and obtain light of various colors, and color rendering High output light can be obtained.

  The translucent member has a function of transmitting at least part of light, and is not limited to a transparent color. The light transmissive member is preferably made of a material having a low absorption rate of light emitted from the semiconductor laser element 120. Specifically, quartz glass, borosilicate glass, low melting point glass, silicone resin, epoxy resin, and the like can be given.

  The shape of the wavelength conversion member 140 may be any shape such as a disc shape, a hemispherical shape, a ball shape, a lens shape, a conical shape, or a truncated cone shape. For example, between the two ends, an annular shape having a consistent size, a reverse tapered shape whose diameter increases in the light traveling direction, or a semi-spherical shape or a plano-convex shape whose diameter enlargement ratio decreases in the light traveling direction. It is good. Further, in the wavelength conversion member 140, in consideration of the refractive index difference generated at the interface with the air on the light output side, the shape of the light output side of the wavelength conversion member 140 is appropriately selected and processed to collect and diffuse the light. It is possible to control the wavefront.

  In addition to the wavelength conversion material, an appropriate member such as a viscosity extender, a light diffusing substance, or a pigment can be added to the wavelength conversion member 140 according to the present invention depending on the intended use. Examples of the light diffusing substance include barium titanate, titanium oxide, aluminum oxide, silicon carbide, silicon dioxide, heavy calcium carbonate, light calcium carbonate, silver, and a mixture containing at least one of these. As a result, a light emitting device having good directivity can be obtained. Similarly, various colorants can be added as a filter material having a filter effect of cutting unnecessary wavelengths from the extraneous light and the semiconductor laser element 120.

  By using a light diffusing material and a wavelength conversion material such as a phosphor together, light from the semiconductor laser device 120 and the phosphor is diffusely reflected well, and color unevenness that is likely to occur by using a phosphor with a large particle size is suppressed. Can be used preferably.

  In addition to the wavelength conversion member 140, a layer containing a light diffusing material as described above may be provided as the second diffusion member in the opening direction of the recess 111. Thereby, the chromaticity dispersion | variation of a light-emitting device can be suppressed. Such a layer is preferably provided in contact with the wavelength conversion member 140.

(Reflector)
The reflector 150 is provided on the upper surface of the base 110. Specifically, the reflector 150 is fixed to the outer peripheral surface of the recess opening so as to cover the recess 111 of the base 110.
A through hole 155 that penetrates in the opening direction of the concave portion 111 of the base 110 is formed in the approximate center of the reflector 150. Further, out of the both ends of the through hole 155, the side where the light emitted from the semiconductor laser element 120 enters is referred to as a light incident part 156, and the other end is referred to as a light output part 157. Light traveling in the opening direction of the recess 111 of the base 110 travels into the through hole 155 from the light incident portion 156. The light that has traveled into the through hole 155 travels straight, or is guided while being reflected by the inner surface of the through hole 155 one or more times, and is emitted from the light exit portion 157.
In the present embodiment, the wavelength conversion member 140 is disposed so as to block the through hole 155 of the reflector 150, and the light that has traveled through the through hole 155 of the reflector 150 enters the wavelength conversion member 140. Here, “disposing so as to close” includes disposing in the through hole 155, disposing on the upper surface side of the reflector 150 so as to cover the through hole 155, and the like.

The opening shape of the through-hole 155 provided in the reflector 150 can be a circle, an ellipse, a rectangle, a square, a diamond, a polygon, or a shape that approximates these shapes.
The through-hole 155 of the reflector 150 may have a side surface that is inclined or curved so as to have a wide opening from the light incident side to the light emitting side from the semiconductor laser element 120.
FIG. 5 is a schematic cross-sectional view showing an example of the through hole of the reflector. As the shape of the through-hole 155 of the reflector 150, for example, the region in the through-hole 155 has a substantially inverted truncated cone shape, that is, the inner diameter increases from the light incident part 156 side toward the light output part 157 side. Can be mentioned.

By providing the through hole 155 having such a shape, light returning from the wavelength conversion member toward the light incident portion 156 of the through hole 155 can be reflected by the side surface of the through hole 155. Thereby, the light extraction efficiency can be improved and the deterioration of the semiconductor laser element can be suppressed.
Moreover, since the through-hole 155 is provided in the opening direction of the recess 111 of the base 110, it is possible to prevent a decrease in light output due to the recess 110 of the base 110 being blocked by the reflector 150.

  The design of the through hole 155 in the reflector 150 may be determined in consideration of light extraction efficiency and light distribution. As the shape of the through hole 155 other than the above, the enlargement ratio of the opening diameter may be large near the light incident portion 156 and the enlargement ratio may be small near the light exit portion 157. For example, as shown in FIG. 6, the inner surface may have a curved surface so that the region in the through hole 155 forms a dome shape. The curved inclined portion can refract the light reflected by the inclined portion toward the center of the light output portion 157. Therefore, the number of reflections of light in the through hole 155 can be reduced, and light loss can be reduced. In addition, there is a lens-shaped inclined portion in consideration of the collection of emitted light.

The material of the reflector 150 is copper, iron, cobalt, nickel, gold, aluminum, brass, tungsten, molybdenum, Kovar, stainless steel, CuW, CuMo, or other metals or alloys, or Al ₂ O ₃ , SiC, AlN, diamond. And ceramics. In addition, the reflector 150 and the base 110 are not limited to different members, and both can be the same member, thereby reducing the number of parts of the product. Further, a metal film made of Ag, Al or the like may be formed on the surface of the reflector.

<Modification of Embodiment 1>
FIG. 7 is a plan view schematically showing an example of a light emitting device according to a modification of the first embodiment. FIG. 8 is a schematic sectional view taken along line VIII-VIII ′ of FIG.
The light emitting device of this modification is the same as the light emitting device of the first embodiment described above, but includes a plurality of semiconductor laser elements 120 and is changed so that each emitted light enters the diffusing member 130.
The base 110 is a thin rectangular parallelepiped having a substantially square plane, and has a recess 111 at a substantially center. The bottom surface 112 of the recess 111 is substantially square, and a diffusion member 130 is provided at the center thereof. The plurality of semiconductor laser elements 120 are provided in an annular shape so as to surround the diffusing member 130, and each optical axis is directed to the diffusing member 130.
When a plurality of semiconductor laser elements 120 are used, the luminance as a light emitting device is easily improved, but the light density is increased at the center of the recess 111. In the light emitting device of this modification, the diffusing member 130 is disposed at the center of the recess 111, so that the adverse effect on the wavelength conversion member 140 can be greatly reduced.
<Embodiment 2>
FIG. 9 is a plan view schematically showing a light-emitting device according to Embodiment 2 of the present invention. FIG. 10 is a schematic cross-sectional view taken along the line XX ′ of FIG.
The light emitting device according to the embodiment of the present invention is mainly different from the light emitting device of the first embodiment described above in the configuration of the base 110 and the arrangement of the wavelength conversion member 140.

  In the present embodiment, the base 110 is a rectangular parallelepiped having a substantially rectangular plane. A first concave portion 114 having an inverted truncated pyramid shape is provided at the center of the base 110, and a second concave portion 117 that is a rectangular parallelepiped having a substantially rectangular bottom surface is provided at the center of the bottom surface of the first concave portion. Yes. The semiconductor laser element 120 and the diffusing member 130 are disposed on the bottom surface of the second recess 117. The inner wall of the first recess 114 is inclined so as to have a wider opening toward the upper end side, and has a function as a reflector. The semiconductor laser element 120 and the diffusion member 130 are arranged on the bottom surface of the substantially rectangular second recess 117 so as to be separated from each other and juxtaposed in the longitudinal direction. The optical axis of the semiconductor laser element 120 is substantially parallel to the longitudinal direction of the bottom surface of the second recess 117. The wavelength conversion member 140 is fixed to the bottom surface of the first recess 114 so as to cover a part of the second recess 117.

  In the light emitting device of this embodiment, a light transmitting body 160 is provided on the upper surface of the base 110 so as to cover the first recess 114. Thereby, a space constituted by the light transmitting body 160, the first concave portion 114, and the second concave portion 117 is formed, and the semiconductor laser element 120, the diffusing member 130, and the wavelength converting member 140 are disposed in this space. become. Therefore, these members can be protected from the outside.

  The light transmissive body 160 may be anything as long as it transmits at least part of the light. The light transmissive body 160 is preferably made of a material having a low absorption rate of light emitted from the semiconductor laser element 120 and the wavelength conversion member 140. Specifically, quartz glass, borosilicate glass, low melting point glass, silicone resin, epoxy resin, and the like can be given.

The shape of the wavelength conversion member 140 may be any shape such as a disc shape, a hemisphere shape, a ball shape, a lens shape, a cone shape, a truncated cone shape, a pyramid shape, a truncated pyramid shape, and a prism shape. The shape of the wavelength conversion member 140 is not particularly limited as long as it can be fixed to the bottom surface of the first recess 114 so as to cover part or all of the second recess 117.
FIG. 11 is a plan view showing a modification of the wavelength conversion member according to the present embodiment. FIG. 12 is a schematic cross-sectional view taken along line XII-XII ′ of FIG. The wavelength conversion member 140 may be disposed so as to cover the entire second recess 117 with an elliptical disc shape larger than that of the second recess 117. By doing in this way, only the light radiate | emitted via the wavelength conversion member 140 can be taken out outside.

  The inner wall 116 of the first recess 114 has a function as a reflector. Therefore, it is preferable that the inner wall 116 of the first recess 114 has a height such that the upper surface thereof is positioned above the wavelength conversion member 140.

<Embodiment 3>
FIG. 13 is a plan view schematically showing a light-emitting device according to Embodiment 3 of the present invention. FIG. 14 is a schematic cross-sectional view taken along line XIV-XIV ′ of FIG.
The light emitting device according to the embodiment of the present invention is mainly different from the light emitting device of the second embodiment described above in the configuration of the base.

In the present embodiment, the base 110 is a rectangular parallelepiped with a substantially rectangular plane, and a recess 111 having a substantially rectangular bottom surface 112 is provided at the center of the base 110.
The concave portion 111 of the base 110 has a truncated pyramid shape in which the shape of the bottom surface 112 and the opening shape on the upper end side are substantially rectangular, and the inner wall 113 is inclined so as to become a wide mouth as the distance from the bottom surface 112 increases. . Therefore, the light traveling in the direction of the inner wall 113 of the recess 111 can be efficiently reflected in the opening direction.

  The semiconductor laser element 120 and the diffusing member 130 are arranged on the bottom surface 112 of the recess 111 of the substantially rectangular base 110 so as to be separated from each other and juxtaposed in the longitudinal direction. Further, the optical axis of the semiconductor laser element 120 is substantially parallel to the longitudinal direction of the bottom surface 112 of the recess 111.

In the present embodiment, diffusion member 130 has a cylindrical shape or prismatic shape having an upper surface and a lower surface. The wavelength conversion member 140 is fixed on the upper surface of the diffusion member 130.
The wavelength conversion member 140 is not particularly limited as long as it has a shape having a surface in contact with the upper surface of the diffusion member 130. Specifically, a column, a cone, a frustum, a hemispherical shape, a plano-convex shape, and the like can be given as an example, but a cylindrical shape is preferable because chromaticity variation of the light-emitting device can be reduced.
Moreover, it is preferable that the wavelength conversion member 140 and the diffusing member 130 have substantially the same planar shape.

  Furthermore, the light-emitting device of the present embodiment is provided with a light transmission body 160 so as to cover the recess 111 of the base 110. As a result, a space constituted by the light transmitting body 160 and the recess 111 of the base 110 is formed, and the semiconductor laser element 120, the diffusing member 130, and the wavelength converting member 140 are disposed in this space. Therefore, these members can be protected from the outside.

  In the light emitting device of the present embodiment, the wavelength conversion member 140 is provided so as to extend to the side surface other than the region facing the semiconductor laser element 120 among the side surfaces of the diffusion member 130, as shown in FIG. May be. Thereby, the light emitted from the side surface of the diffusing member 130 enters the wavelength conversion member 140.

<Modification of Embodiment 3>
FIG. 16 is a cross-sectional view schematically showing a light emitting device according to a modification of the third embodiment of the present invention.
The light emitting device of this modification mainly includes a pedestal 170, a semiconductor laser element 120, a diffusion member 130, a wavelength conversion member 140, and a cap 180.

  On the disk-shaped pedestal 170, the semiconductor laser element 120 and the diffusion member 130 are fixed. Further, a cap 180 is welded to the vicinity of the edge of the upper surface of the base 170 by resistance welding or the like so as to cover the semiconductor laser element 120 and the diffusion member 130. Inside the cap, the semiconductor laser element 120 is disposed such that the optical axis faces the inner surface of the cap, and the diffusion member 130 is disposed on the optical axis of the semiconductor laser element 120. The cap 180 has an opening in part. The wavelength conversion member 140 is disposed in the opening direction of the cap 180. Thereby, the light from the diffusing member 130 and the reflected light from the inner surface of the cap 180 are irradiated to the wavelength conversion member 140.

The material of the pedestal 170 is copper, iron, cobalt, nickel, gold, aluminum, brass, tungsten, molybdenum, Kovar, stainless steel, CuMo, CuW, or a metal or alloy, or Al ₂ O ₃ , SiC, AlN, diamond, etc. Is mentioned. Examples of the material of the cap 180 include nickel, cobalt, iron, brass, stainless steel, an alloy of nickel and iron, and an iron-nickel-cobalt alloy (Kovar). The base 170 and the cap 180 are preferably made of a material that improves the weldability of resistance welding, for example, by being joined by resistance welding.

  In the modification of the third embodiment, the cap 180 includes, for example, a cylindrical cap side part 182 and an annular cap upper part 181 that covers the upper end of the cap side part 182. The optical axis of the semiconductor laser element 120 is directed to the inner surface of the cap side portion 182. In addition, an opening 185 penetrating the inside and outside of the cap 180 is formed in the central portion of the cap upper portion 181 in the thickness direction of the cap upper portion 181. Further, the light transmission body 160 is disposed so as to close the opening 185 of the cap upper portion 181. The light transmitting body 160 is fixed by an adhesive member such as silicone resin, ceramic, low melting point glass, solder, etc., so that the inside of the cap 180 is sealed.

  Below, the example of the form which arrange | positions a wavelength conversion member in the opening direction of the cap 180 is demonstrated.

  In the light emitting device shown in FIG. 16, the wavelength conversion member 140 is fixed on the diffusion member 130. In this case, the wavelength conversion member 140 is not particularly limited as long as it has a shape having a surface in contact with the upper surface of the diffusion member 130. Specifically, a column, a cone, a frustum, a hemispherical shape, a plano-convex shape, and the like can be given as an example, but a cylindrical shape is preferable because chromaticity variation of the light-emitting device can be reduced. Moreover, it is preferable that the wavelength conversion member 140 and the diffusing member 130 have substantially the same planar shape.

  In the light emitting device shown in FIG. 17, the wavelength conversion member 140 is disposed so as to close the opening 185 of the cap instead of the light transmitting body 160. As a result, a space formed by the base 170, the cap 180, and the wavelength conversion member 140 disposed so as to close the opening 185 of the cap 180 is formed, and the light traveling in this space is disposed in the opening 185. Only the light passing through the wavelength conversion member 140 can be extracted to the outside.

<Embodiment 4>
FIG. 18 is a cross-sectional view schematically showing a light emitting device according to Embodiment 4 of the present invention.
The light emitting device according to the embodiment of the present invention is different from the light emitting devices of the first and second embodiments described above in the configuration of the diffusing member.

In the present embodiment, the diffusing member 130 is made of metal and has an inclined surface 132 that is inclined or curved with respect to the optical axis of the semiconductor laser element 120 on the light receiving side that is the surface facing the semiconductor laser element 120. ing. The shape of the inclined surface 132 can be appropriately selected in consideration of optical characteristics.
By using such a diffusing member 130, the light from the semiconductor laser element 120 is not directly incident on the wavelength converting member 140, but is once reflected by the inclined surface 132 of the diffusing member 130 and then to the wavelength converting member 140. Since the light is incident, the concentration of light on the wavelength conversion member 140 can be reduced, and deterioration of the wavelength conversion member 140 can be reduced.

Diffusing member 130 in the present embodiment is a member that reflects light emitted from semiconductor laser element 120 and light emitted from wavelength conversion member 140 (for example, a member that reflects light having a wavelength in the range of 350 nm to 800 nm). It is preferably formed by. Specific examples of the material include metals such as Ag, Au, Al, Ni, In, and Pd, and alloys such as In—Ag and Au—Ag. Further, ceramics such as alumina (Al ₂ O ₃ ) and zirconia (ZrO ₂ ), barium sulfate (BaSO ₄ ), and the like may be used. In diffusion member 130 in the present embodiment, at least inclined surface 132 only needs to be made of such a material.

  Further, the inclined surface 132 of the diffusing member 130 can be a surface having irregularities. Examples of the unevenness provided on the inclined surface 132 include those in which a height difference that can reflect at least light from the semiconductor laser element 120 is regularly or irregularly formed. By providing such unevenness, the density of light emitted from the semiconductor laser element 120 can be further reduced, and reflection with high coherence can be prevented. Further, by providing such unevenness on the inclined surface 132, chromaticity variation of the light emitting device can be suppressed. Such an uneven surface can be applied not only to the inclined surface 132 of the diffusion member 130 but also to the inner wall 113 of the recess 111 of the base 110.

<Embodiment 5>
FIG. 19 is a schematic cross-sectional view showing a light-emitting device according to Embodiment 5 of the present invention.
The light emitting device according to the embodiment of the present invention is different from the light emitting device of Embodiment 4 described above in that the diffusing member 130 and the base 110 are formed as an integral part using the same member.
That is, in the light emitting device according to the present embodiment, an inclined surface 132 that is inclined or curved with respect to the optical axis of the semiconductor laser element 120 is formed on the inner wall 113 of the recess 111 of the base 110. The inclined surface 132 can reflect or diffuse light from the semiconductor laser element 120.
In the light emitting device of the present embodiment, the same effects as those of the light emitting device of Embodiment 4 can be obtained, and the number of product parts can be reduced. Also in this embodiment, the inclined surface 132 may be provided with unevenness.

  Moreover, you may provide a light-diffusion substance etc. in the inclined surface 132 formed in the inner wall 113 of the recessed part 111 as another member. Thereby, the light from the semiconductor laser element 120 can be reflected in a state with lower coherence.

  The light-emitting device of the present invention can be used for lighting fixtures, on-vehicle lighting, displays, indicators, and the like.

It is a top view which shows typically the light-emitting device which concerns on Embodiment 1 of this invention. It is typical sectional drawing in the II-II 'line | wire of FIG. FIG. 6 is a plan view schematically showing an arrangement example of reflecting members 190. It is sectional drawing which shows the example of arrangement | positioning of the reflection member 190 typically. It is a schematic sectional drawing which shows an example of the through-hole of the reflector in the light-emitting device of this invention. It is a schematic sectional drawing which shows an example of the through-hole of the reflector in the light-emitting device of this invention. It is a top view which shows typically an example of the light-emitting device which concerns on the modification of Embodiment 1 of this invention. It is typical sectional drawing in the VIII-VIII 'line | wire of FIG. It is a top view which shows typically the light-emitting device which concerns on Embodiment 2 of this invention. It is typical sectional drawing in the X-X 'line | wire of FIG. It is the top view which showed the modification of the wavelength conversion member in the light-emitting device of this invention. It is typical sectional drawing in the XII-XII 'line | wire of FIG. It is a top view which shows typically the light-emitting device which concerns on Embodiment 3 of this invention. It is typical sectional drawing in the XIV-XIV 'line | wire of FIG. It is the top view which showed the modification of the wavelength conversion member in the light-emitting device of this invention. It is sectional drawing which shows typically the light-emitting device which concerns on the modification of Embodiment 3 of this invention. It is sectional drawing which shows typically the example of arrangement | positioning of the wavelength conversion member in the modification of Embodiment 3 of this invention. It is sectional drawing which shows typically the light-emitting device which concerns on Embodiment 4 of this invention. It is a schematic sectional drawing which shows the light-emitting device concerning Embodiment 5 of this invention. It is a schematic sectional drawing which shows the conventional light-emitting device.

Explanation of symbols

100 light emitting device 110 base 111 recess 112 bottom surface 113 inner wall 114 first recess 117 second recess 120 semiconductor laser element 130 diffusing member 132 inclined surface 140 wavelength converting member 150 reflector 155 through-hole 156 light incident portion 157 light emitting portion 160 light Transmitter 170 Base 180 Cap 190 Reflective member 200 Light emitting device 210 Submount heat sink 220 Semiconductor laser element 240 Phosphor composition 260 Transparent cap 270 Base 280 Casing wall 298 Dome lens

Claims (4)

A base having a recess having a bottom surface and an inner wall;
A semiconductor laser element Oite, the optical axis is arranged to face the inner wall of the recess in the recess,
Oite in the recess, and the diffusion member for diffusing light of the semiconductor laser element arranged on the optical axis of the semiconductor laser element,
A reflector fixed so as to cover the recess, and having a through hole in the opening direction of the recess;
Emitting device characterized by comprising a wavelength converting member for converting the light of a different wavelength by absorbing light of said semiconductor laser element disposed so as to close the through hole. The light-emitting device according to claim 1, wherein the diffusion member contains a filler in glass or resin. The diffusing member, the is formed by a material which reflects light from the semiconductor laser device, according to claim 1, characterized in that it comprises an inclined surface inclined or curved with respect to the optical axis of the semiconductor laser element Light-emitting device. The light emitting device according to claim 3 , wherein the inclined surface has irregularities.

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