JP2006165101A - Envelope for light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an envelope for a light-emitting device having satisfactory heat dissipation performance and a high light amount extraction rate when a plurality of light-emitting devices are arranged. <P>SOLUTION: A shelf 23 is formed in the middle of a diffusion reflecting surface 221, and thus, the light-emitting devices are separated from each other and heat dissipation is satisfactory and temperature rise of the light-emitting devices can be suppressed to low, although the light-emitting device 5B generates a heat when emitting a light. Also, since the shelf 23 is formed and a light is reflected on not only a diffusion reflecting surface 221 on the upper side (outside) of the shelf 23 but also a diffusion reflecting surface 221 on the lower side (inside) of the shelf 23, the light quantity extraction rate can be increased. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an envelope of a light emitting element that has good heat dissipation and a high light quantity extraction rate when a plurality of light emitting elements are arranged.

  Conventionally, as an envelope of a light emitting element, for example, there is one described in Patent Document 1. In this envelope, as shown in FIG. 8 of the same document, the upper surface electrode 72a of the lead frame 72 and the upper surface electrode 73a of the lead frame 73 are arranged on the bottom surface of the concave portion whose inner wall is inclined. One electrode of the light emitting element 54 is connected to the upper surface electrode 72 a, and the other electrode of the light emitting element 54 is connected to the upper surface electrode 73 a through the wire 55. This recess is sealed with a light-transmitting sealing resin 56.

  With such a configuration, the envelope of the same document realizes a light source based on surface emission by radiating light emitted from the light emitting element 54 to the outside through the upper surface of the sealing resin 56.

Moreover, as an envelope of a multicolor light emitting element, for example, there is one shown in FIG. In this envelope 200, the bottom surface 21 of the recess is divided into four parts, one of which is a red light emitting element 5, the other is a green light emitting element 5, and the other is a blue light emitting element 5. Moreover, mixed color light is generated by bringing them close to each other.
JP 2003-163378 A

  However, in the envelope of FIG. 11, since the light emitting elements 5 are close to each other, it is suitable for generating mixed color light, but its heat dissipation is poor. Further, since the light emitting element 5 is not disposed on the remaining one of the four divided bottom surfaces 21, the mixed color light is biased.

  Further, even when the envelope shown in FIG. 11 is used as a single-color envelope, the heat dissipation is poor, and the recess is a simple mortar shape, so that a high light quantity extraction rate cannot be obtained.

  The present invention has been made in view of the above, and an object of the present invention is to provide an envelope of a light emitting element that has good heat dissipation and a high light quantity extraction rate when a plurality of light emitting elements are arranged. .

  In order to solve the above-mentioned problem, the envelope of the light emitting element according to claim 1 is provided with a recess in which the inner wall surface is inclined and filled with a transparent material, and a plurality of light emitting elements are dispersed in the middle of the inner wall surface. It is characterized by forming a shelf to be arranged.

  According to the envelope of claim 1, since the light emitting elements are separated from each other by forming the shelf in the middle of the inner wall surface, heat dissipation is good, not only the inner wall surface above the shelf but also below the shelf. Since the light also reflects on the inner wall surface and the light tends to gather on the inner wall surface, the light quantity extraction rate can be increased.

  The envelope of the light-emitting element according to claim 2 includes a concave portion in which an inner wall surface is inclined and is filled with a transparent material, leaving a region where a plurality of light-emitting elements are dispersedly arranged on a bottom surface of the concave portion. It is characterized by forming a depression.

  According to the envelope of the second aspect, since the recesses are formed on the bottom surface of the concave portion so as to leave a region where a plurality of light emitting elements are dispersed and arranged, the light emitting elements are separated from each other, and thus heat dissipation is good. In addition, since light tends to be reflected not only at the inner wall surface but also at the dent, and the light tends to collect in the dent by the inner wall surface, the light quantity extraction rate can be increased.

  The envelope of the light emitting element according to claim 3 is the envelope according to claim 1 or 2, wherein a lead frame for supplying electric power to the plurality of light emitting elements protrudes outward.

  According to the envelope of the third aspect, the heat dissipation can be further improved by projecting the lead frame to the outside.

  According to the envelope of the light emitting element of the present invention, since the light emitting elements are separated from each other by forming a shelf in the middle of the inner wall surface, heat dissipation is good, not only the inner wall surface above the shelf, Light also reflects on the lower inner wall surface, and the light tends to collect on the inner wall surface, so that the light quantity extraction rate can be increased.

  In addition, according to the envelope of the light emitting element of the present invention, since the recesses are formed on the bottom surface of the recess, leaving a region where the plurality of light emitting elements are dispersed and arranged, the light emitting elements are separated from each other. Since the light is reflected not only on the inner wall surface but also on the depression and the light tends to collect in the depression by the inner wall surface, the light quantity extraction rate can be increased.

  Moreover, according to the envelope of the light emitting element of the present invention, the heat dissipation can be further improved by projecting the lead frame to the outside.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a perspective view of an envelope 100A of a light emitting element in the first embodiment.

  The envelope 100A is generally called an SMD (surface mount device) type, and the package 1 having a frame structure made of white PPA (polyphthalamide) resin that reflects received light under conditions close to perfect diffuse reflection. Prepare. A circular recess 2 is formed in the package 1 when viewed from above. A diffuse reflection surface 221 is formed on the surface of the inner wall 22 of the recess 2. The diffuse reflection surface 221 is inclined with respect to the circular bottom surface 21, and the concave portion 2 has a so-called mortar shape. An annular shelf 23 is formed in the middle of the diffuse reflection surface 221 in parallel with the bottom surface 21 as viewed from above.

  On the shelf 23, metal upper surface electrodes 3a, 3a, 3a of the lead frame 3 (not shown) and upper surface electrodes 4a, 4a, 4a of the lead frame 4 are respectively arranged.

  On each upper surface electrode 3a, one electrode of a blue light emitting element 5B composed of a light emitting element corresponding to the upper surface electrode 3a, for example, an LED (Light Emitting Diode) or the like is electrically conductive material (silver paste or eutectic crystal). The other electrode of the light emitting element 5B is connected to the upper surface electrode 4a arranged next to the upper surface electrode 3a through a wire 6 made of gold or the like. In this state, the concave portion 2 is filled with a transparent material 7 such as a translucent epoxy resin in a liquid state, for example, and is thermally cured. The boundary surface 71 between the transparent material 7 and air is parallel to the bottom surface 21 and the shelf 23. The transparent material 7 may contain a phosphor.

  Each light emitting element 5B is large and has a low thermal resistance, for example, not 1 mm square or more, for example, 300 μm square, and the outer diameter of the shelf 23 is about 1 cm. Further, the light emitting elements 5 are optimally arranged, that is, evenly arranged, and the interval thereof is, for example, about 3.9 mm.

  In the envelope 100A, when electric power is supplied from the lead frames 3 and 4, each light emitting element 5B connected thereto emits blue light. At that time, part of the blue light passes through the boundary surface 71 and is directly emitted to the outside. The remaining blue light is reflected by the boundary surface 71 and the diffuse reflection surface 221 and then emitted to the outside. When the transparent material 7 includes a phosphor, the phosphor is excited by blue light, and white light or pale color light is emitted from the envelope 100A.

  The light emitting element 5B generates heat during light emission. However, since the light emitting elements are separated from each other by forming the shelves 23 in the middle of the diffuse reflection surface 221, the heat dissipation is good and the temperature rise of the light emitting elements is kept low. Can do.

  Further, since the shelf 23 is formed in the middle of the diffuse reflection surface 221, light is transmitted not only on the diffuse reflection surface 221 above (outside) the shelf 23 but also on the diffuse reflection surface 221 below (inside) the shelf 23. Since the light is reflected, the light extraction rate can be increased.

  Further, since the diffuse reflection surface 221 above (outside) the shelf 23 is present, the light tends to gather below the shelf 23. However, since the diffuse reflection surface 221 is also present there, the light quantity extraction rate can be further increased.

  Instead of each light emitting element 5R, red light and green light may be obtained using a red light emitting element 5R and a green light emitting element 5G.

  In addition, the bottom surface 21 is not necessarily required, that is, the portion below (inside) the shelf 23 may have an inverted conical shape, thereby reducing the installation area of the envelope 100A. The same applies to the envelopes 100B, 100C, and 100D described later.

[Second Embodiment]
FIG. 2 is a perspective view of the envelope 100B of the light emitting element in the second embodiment.

  As shown in FIG. 2, the envelope 100 </ b> B is outside the envelope 100 </ b> A or other embodiments described later except that the lead frame 3 of the envelope 100 </ b> A protrudes outward from the package 1. It is constructed in the same way as the envelope. That is, the effect obtained by the configuration can be obtained also by the envelope 100B.

  FIG. 3 is a perspective view of the envelope 100 </ b> B with the upper portion removed from the shelf 23.

  As shown in FIG. 3, the lead frame 3 is formed integrally with fins 9, 9 for heat dissipation, and each fin 9 is a side surface different from the side surface where the lead frames 3, 4 are exposed in the package 1. And then bent upward.

  As described above, the lead frame 3 is integrated with the fins 9 and protrudes outward from the package 1, so that heat from the light emitting element 5B can be released to the outside of the envelope 100B by natural convection, for example. Further, by applying wind from an electric fan (not shown) or the like to the fins 9, that is, by air cooling, heat dissipation becomes better.

  Further, since the installation area of the envelope 100B can be reduced and the surface area of the fin 9 can be increased by bending the fins 9, the installation area of the envelope 100B can be reduced and the heat dissipation can be improved. Further, by bending the fin 9 upward, there is no contact between the printed circuit board on which the envelope 100B is mounted and the envelope 100B, and the mounting of the envelope 100B is facilitated.

[Third Embodiment]
FIG. 4 is a perspective view of the envelope 100C of the light emitting element in the third embodiment.

  As shown in FIG. 4, in the envelope 100C, the two light emitting elements 5B of the envelope 100A are red light emitting elements 5R and 5R, and the other two light emitting elements 5B are green light emitting elements 5G and 5G. Is. Further, in one set including the light emitting element 5R, the light emitting element 5G, and the light emitting element 5B and the other set, the light emitting elements are optimally arranged, that is, evenly arranged.

  By configuring the other parts of the envelope 100C in the same manner as the envelope 100A, the effects obtained by the configuration can be obtained in the envelope 100C. Further, by configuring the other parts in the same manner as in other embodiments described later, the effect obtained by the configuration can be obtained in the envelope 100C.

  In the envelope 100C, red light, green light, and blue light are emitted from the light emitting element 5R, the light emitting element 5G, and the light emitting element 5B, respectively. A part of the light passes through the boundary surface 71 and is emitted to the outside before being mixed. Further, the remaining light is mixed after being reflected by the boundary surface 71 and the diffuse reflection surface 221 and then emitted to the outside.

  In the envelope 100C, by forming the shelf 23 in the middle of the diffuse reflection surface 221, not only the diffuse reflection surface 221 above (outside) the shelf 23 but also the diffuse reflection surface 221 below (inside) the shelf 23. In this case, the light is reflected, so that the color mixing efficiency can be increased.

Further, since the diffuse reflection surface 221 above (outside) the shelf 23 is present, the light tends to gather below the shelf 23, but since there is also the diffuse reflection surface 221, the color mixing efficiency can be further increased. [Fourth Embodiment]
FIG. 5 is a perspective view of a light emitting device envelope 100D according to the fourth embodiment.

  As shown in FIG. 5, in the envelope 100D, the light emitting elements 5R, 5G, and 5B of the envelope 100C are reduced one by one. Further, instead of the lead frame 4, a lead frame 4R that supplies power to the light emitting element 5R, a lead frame 4G (not shown) that supplies power to the light emitting element 5G, and a lead frame 4B (not shown) that supplies power to the light emitting element 5B are provided. . Further, the shelf 23 is provided with the upper surface electrodes 3a, 3a, 3a of the lead frame 3, the upper surface electrode 4Ra of the lead frame 4R, the upper surface electrode 4Ga of the lead frame 4G, and the upper surface electrode 4Ba of the lead frame 4B. Yes.

  That is, the envelope 100D is a PLCC (Plastic Leadless Chip Carrier) -4 type 4-terminal package.

  By configuring the other parts of the envelope 100D in the same manner as the envelope 100C and the envelopes of the other embodiments, the effects obtained by the configuration can also be obtained in the envelope 100D. In the envelope 100D, the power PR is supplied from the lead frames 3 and 4R to the light emitting element 5R, the power PG is supplied from the lead frames 3 and 4G to the light emitting element 5G, and the light from the lead frames 3 and 4B to the light emitting element 5B. When power PG is supplied, each of these light emitting elements emits light. Here, by determining the electric powers PR, PG, and PB individually, light of a desired color or white light can be extracted.

[Fifth Embodiment]
FIG. 6 is a perspective view of a light emitting device envelope 100E according to the fifth embodiment.

  The envelope 100E is an SMD type and includes a package 1A having a frame structure made of white PPA resin. The package 1A has a rectangular recess 2A as viewed from above. On the surfaces of the inner walls 22Aa, 22Ab, 22Ac, 22Ac of the recess 2A, a diffuse reflection surface 221A inclined with respect to the rectangular bottom surface 21A is formed.

  On the bottom surface 21A of the envelope 100E, a recess is formed leaving a region where the light emitting element is disposed. For example, on the bottom surface 21 </ b> A, a plurality of depressions having a suitable shape, i.e., inverted conical depressions 30, are formed, and a diffuse reflection surface 31 </ b> A is formed on the surface of the inner wall 31 of the depression 30.

  On the bottom surface 21A between the inner wall 22Aa and each recess 30, one upper surface electrode 4Ra of the lead frame 4R, one upper surface electrode 3Ra of the lead frame 3, another one upper surface electrode 3Ga of the lead frame 3, and a lead (not shown) One upper surface electrode 4Ga of the frame 4G, another upper surface electrode 3Ba of the lead frame 3, and one upper surface electrode 4Ba of the lead frame 4B (not shown) are arranged side by side.

  In addition, the upper surface electrodes 4Ra, 3Ra, 3Ga, 4Ga, 3Ba, and 4Ba are also arranged side by side on the bottom surface 21A between the inner wall 22Ac that faces the inner wall 22Aa and each recess 30.

  Further, the upper surface electrodes 3Ra face each other with the depressions 30 interposed therebetween. The same applies to each upper surface electrode 4Ra, each upper surface electrode 3Ga, each upper surface electrode 4Ga, each upper surface electrode 3Ba, and each upper surface electrode 4Ba.

  On each upper surface electrode 3Ra, one electrode of the red light emitting element 5R corresponding to the upper surface electrode 3Ra is connected using a conductive material, and the other electrode of the light emitting element 5R is adjacent to the other electrode via the wire 6. To the upper surface electrode 4Ra.

  On each upper surface electrode 3Ga, one electrode of the green light emitting element 5G corresponding to the upper surface electrode 3Ga is connected using a conductive material, and the other electrode of the light emitting element 5R is adjacent to the other through the wire 6. To the upper surface electrode 4Ga.

  On each upper surface electrode 3Ba, one electrode of the green light emitting element 5B corresponding to the upper surface electrode 3Ba is connected using a conductive material, and the other electrode of the light emitting element 5B is adjacent to the other electrode through the wire 6. To the upper surface electrode 4Ba.

  In this state, the recess 2A is filled with the transparent material 7. The boundary surface 71 between the transparent material 7 and air is parallel to the bottom surface 21.

  In the envelope 100E, power PR is supplied from the lead frames 3 and 4R to the light emitting element 5R, power PG is supplied from the lead frames 3 and 4G to the light emitting element 5G, and the lead frames 3 and 4B to the light emitting element 5B. When power PG is supplied, the light emitting element 5R, the light emitting element 5G, and the light emitting element 5B emit red light, green light, and blue light. At that time, a part of the light passes through the boundary surface 71 and is emitted to the outside, and then mixed. Further, the remaining light is mixed after being reflected by the boundary surface 71 and the diffuse reflection surface 221 and then emitted to the outside.

  Here, by uniquely determining the powers PR, PG, and PB, light of a desired color or white light can be extracted.

  The light emitting elements 5R, 5G, and 5B generate heat during light emission, but the depressions 30 are formed by leaving the regions where the light emitting elements 5R, 5G, and 5B are dispersed and arranged. Therefore, the heat dissipation is good and the temperature rise of the light emitting element can be kept low.

  In addition, since the depressions are formed while leaving the regions where the light emitting elements are dispersedly arranged, the light is reflected not only on the diffusion reflection surface 221 but also on the diffusion reflection surface 31A of the depressions, so that the light quantity extraction rate can be increased. In addition, the presence of the diffuse reflection surface 221 tends to cause light to collect in a region other than the region where the light emitting element is disposed. However, since there is also the diffuse reflection surface 31A, the light quantity extraction rate can be further increased.

  In addition, even if the dent on the bottom surface is shallow, by providing a plurality of dents, it is possible to extract the same amount of light as when a deep dent is provided.Therefore, providing a plurality of dents on the bottom surface increases the light quantity extraction rate. In addition, the envelope of the light emitting element can be made thin. As a result, a surface light source using this envelope as a unit module can be realized, and this can be used for a backlight of a thin liquid crystal display device.

  In the envelope 100E, each light emitting element may be a blue light emitting element 5G to extract blue light. Moreover, you may take out white light etc. by including fluorescent substance in the transparent material at this time. Moreover, you may improve heat dissipation by providing the fin 9 of the envelope 100B. Further, instead of the lead frames 4R, 4G, 4B, a single lead frame 4 may be provided.

  Now, the angle formed by the diffuse reflection surface 221 and the diffuse reflection surface 31A (hereinafter referred to as “diffuse reflection surface 221”) of the above embodiment and the shelf 23 and the bottom surface 21 (hereinafter referred to as “bottom surface 21”). Is the same as the incident critical angle at which the direct light radiated from the light emitting element of the above embodiment (hereinafter referred to as “light emitting element 5”) causes total reflection with respect to the boundary surface 71. Can be improved. The light quantity extraction rate can also be improved by setting the angle formed by the diffuse reflection surface 221 to the bottom surface 21 to be within a range of ± 15 ° of the incident critical angle or smaller than the incident critical angle.

  The reason why the light quantity extraction rate is improved by such an angle setting will be described. For ease of understanding, description will be made using the envelope 101 in which the shelf 23 is removed from the envelope 100A and the light emitting element 5 is provided on the bottom surface 21.

  FIG. 7 is a perspective view of the envelope 101, and FIG. 8 is a cross-sectional view of the envelope 101.

  As shown in FIG. 7, the envelope 101 removes the shelf 23 from the envelope 100A and arranges the upper surface electrode 3a of the lead frame 3, the upper surface electrode 4a of the lead frame 4, and the light emitting element 5 on the bottom surface 21 one by one. It is a thing. Electrical connection is made in the same manner as the envelope 100A.

  As shown in FIG. 8, the angle θ1 formed by the diffuse reflection surface 221 formed on the surface of the inner wall 22 of the recess 2 and the bottom surface 21 is such that the direct light emitted from the light emitting element 5 is totally reflected on the boundary surface 71. This coincides with the incident critical angle θ2 that occurs.

  For example, when an epoxy resin is used for the transparent material 7, the refractive index is approximately n = 1.5, which is larger than the refractive index n of air = 1. In this case, the incident critical angle at the interface between the epoxy resin and the air is θ2 = 49 °, and light incident from the light emitting element 5 to the boundary surface 71 at an incident angle larger than 49 ° is refracted and emitted to the outside. However, light incident at an incident angle smaller than 49 ° is totally reflected and returns to the inside of the recess 2.

  That is, as the direct light from the light emitting element 5, only the light within the extraction cone 80 in which the position of the light emitting element 5 is the apex, the boundary surface 71 is the bottom surface, and the angle between the side surface and the boundary surface 71 is 49 °. It can be taken out. The direct light inside the extraction cone 80 is radiated to the air layer side without being attenuated by reflection at the diffuse reflection surface 221 or the boundary surface 71.

  On the other hand, as light that can be extracted to the outside, in addition to the direct light from the light emitting element 5, there is light reflected by the diffuse reflection surface 221. How to extract the light reflected by the diffuse reflection surface 221 to the outside is important for efficiently radiating the light from the light emitting element 5 to the outside.

  In the envelope 101, the light hitting the diffuse reflection surface 221 is diffusely reflected and reflected in all directions. At this time, if the diffuse reflection surface 221 is assumed to be perpendicular to the bottom surface of the recess, the light reflection position on the diffuse reflection surface 221 is the apex, the boundary surface is the bottom surface, and the angle between the side surface and the boundary surface is 49 °. Of the light inside the extraction cone (referred to as extraction cone 81), half of the light falls on the diffuse reflection surface 221 and cannot be extracted outside.

  Therefore, as shown in FIG. 9, by making the angle θ1 formed by the diffuse reflection surface 221 and the bottom surface 21 coincide with the incident critical angle θ2, the extraction cone 81 is completely secured in the transparent material 7, and the extraction cone 81 So that all the light in can be taken out.

  Alternatively, the angle θ1 is made smaller than the incident critical angle θ2. Also in this case, since the extraction cone 81 is completely secured in the transparent material 7, all the light in the extraction cone 81 can be extracted to the outside.

  On the other hand, when the angle θ1 is extremely larger or extremely smaller than the incident critical angle θ2, the light reflected by the diffuse reflection surface 221 often cannot pass through the boundary surface 71, and the light is again transparent. It will be reflected back into the material 7. Such light is repeatedly reflected by the diffuse reflection surface 221 and the bottom surface 21 in the transparent material 7 and attenuates as the optical path distance becomes longer, so that the amount of light that can be extracted to the outside decreases. For this reason, it is desirable that the angle θ1 is within an appropriate range.

  FIG. 10 is a graph showing the transition of the light quantity extraction rate when an epoxy resin is used as the transparent material. The horizontal axis is the angle θ1 (°), and the vertical axis is the light quantity extraction rate (%). The vertical axis represents the extracted light amount when the angle θ1 is 70 ° as 100%, and is shown as a relative value with respect to this light amount. From the graph, it is confirmed that when the angle θ1 is matched with the incident critical angle of 49 °, the light quantity extraction rate is maximized, and the value is improved by 20% compared to the case where the angle θ1 is 70 °. It was. In addition, when the angle θ1 is within the range of 49 ° ± 15 ° of the incident critical angle, it was confirmed that the light quantity extraction rate is improved by 10% or more.

  The angle setting as described above is performed on at least one of the upper (outer) and lower (inner) diffuse reflection surfaces 221 of the shelf 23 if a sufficient amount of light or a desired color is obtained in the envelope 100A. Adopt it. In addition, this angle is set so that either a sufficient amount of light or a desired color can be obtained in the envelope 100E, either the diffuse reflection surface 221 of the inner walls 22Aa, 22Ab, 22Ac, 22Ac or the diffuse reflection surface 31A of each recess 30. Or more than one.

It is a perspective view of envelope 100A of the light emitting element in the first embodiment. It is a perspective view of the envelope 100B of the light emitting element in the second embodiment. It is a perspective view of envelope 100B which removed the upper part from shelf 23. FIG. It is a perspective view of the envelope 100C of the light emitting element in the third embodiment. It is a perspective view of envelope 100D of the light emitting element in 4th Embodiment. It is a perspective view of envelope 100E of the light emitting element in a 5th embodiment. It is a perspective view of envelope 101 used for explanation of angle setting in each embodiment. 3 is a cross-sectional view of the envelope 101. FIG. It is a figure for demonstrating the reflected light which can be taken out outside when the angle (theta) 1 is made to correspond with the incident critical angle (theta) 2. FIG. It is a figure for demonstrating the reason for the light quantity extraction rate improving in each embodiment. It is a perspective view of the envelope of the conventional light emitting element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1A ... Package 2, 2A ... Recessed part 3, 4, 4R, 4G, 4B ... Lead frame 3a, 3Ra, 3Ga, 3Ba, 4a, 4Ra, 4Ga, 4Ba ... Upper surface electrode 5, 5R, 5G, 5B ... Light emitting element 6 ... Wire 7 ... Transparent material 9 ... Fin 21,21A ... Bottom surface 22,22Aa, 22Ab, 22Ac, 22Ad, 31 ... Inner wall 23 ... Shelves 31A, 221,221A ... Diffusion reflection surface 71 ... Boundary surface 80, 81 ... Extraction cone 100A, 100B, 100C, 100D, 100E, 101 ... envelope

Claims (3)

  An envelope of a light-emitting element, comprising a recess in which an inner wall surface is inclined and filled with a transparent material, and a shelf on which a plurality of light-emitting elements are dispersed is formed in the middle of the inner wall surface.   An outer surface of the light emitting device, wherein the inner wall surface is inclined and a recess filled with a transparent material is formed, and a recess is formed on the bottom surface of the recess leaving a region where a plurality of light emitting devices are dispersedly arranged. Envelope. The envelope of the light emitting element according to claim 1, wherein a lead frame for supplying electric power to the plurality of light emitting elements protrudes outward.

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