JP2014175644A - Semiconductor light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor light-emitting device in which an adhesive agent which is inexpensive but is not excellent in light resistance and thermal resistance can be used for adhering a phosphor plate.SOLUTION: The semiconductor light-emitting device includes: a condenser lens 4 for condensing excitation light emitted from an excitation light source 3; a holder part 6 having a through hole 7 through which the condensed excitation light passes; a first transparent member 9 for converting the wavelength of the excitation light; and a second transparent member 8 positioned in the through hole 7. The through hole 7 has a small diameter part 7a, a middle diameter part 7c, and a large diameter part 7d. The diameter of the small diameter part 7a is smaller than that of the middle diameter part 7c, and the diameter of the middle diameter part 7c is smaller than that of the large diameter part 7d. The first transparent member 9 is adhered by an adhesive agent 13 on a holder 6a at the middle diameter part 7c on the side opposite to the excitation light source 3. The spherical second transparent member 8 is fitted between the small diameter part 7a and the middle diameter part 7c. The excitation light condensed by the condenser lens 4 and then diffused is incident on the first transparent member 9 after passing through the spherical second transparent member 8.

Description

  The present invention relates to a light emitting device, and more particularly to a light emitting device having a structure in which a semiconductor light emitting element (for example, a semiconductor laser or a light emitting diode) and a wavelength conversion member (for example, a phosphor) are combined.

  Conventionally, a light emitting device having a structure in which a semiconductor laser light source and a phosphor are combined has been proposed.

  The light-emitting device described in Patent Literature 1 includes a semiconductor laser element, a phosphor plate disposed at a position spaced from the semiconductor laser element, a holder for holding the semiconductor laser element and the phosphor plate, and the like. The phosphor plate is fixed to the holder with an adhesive, and the holder opening is closed by the phosphor plate.

  Laser light emitted from the semiconductor laser element passes through a holder opening that is sufficiently wider than the element width, and irradiates a phosphor plate disposed on the opening. The phosphor plate irradiated with the laser light emits mixed color light of the laser light that passes through the phosphor plate and the wavelength converted light (light emission) that is wavelength-converted and emitted by the laser light.

  The light-emitting device described in Patent Document 2 includes a semiconductor laser element, a CAN package that hermetically seals the semiconductor laser element, a phosphor plate that is disposed further away from the CAN package than Patent Document 1, and a CAN package and a phosphor. A condensing lens disposed between the plates, a holder for holding the CAN package, the phosphor plate, and the condensing lens are provided. In order to fix the phosphor plate to the holder, the phosphor plate is engaged by a fixing member and a sleeve and fixed without using an adhesive.

  The laser light is collected by a condenser lens, passes through the through hole of the holder, and irradiates the phosphor plate arranged on the through hole in a spot manner. The phosphor plate irradiated with the laser light emits laser light that passes through the phosphor plate and wavelength-converted light (light emission) that is wavelength-converted and emitted by the laser light.

JP 2008-235744 A JP 2010-165834 A

  However, in the light emitting device described in Patent Document 1, when the phosphor plate is bonded and fixed with an adhesive, an adhesive larger than the bonding area is applied in order to spread the adhesive over the entire surface where the phosphor and the holder are in contact with each other. After that, although a load is applied from above the phosphor plate, there is a possibility that the amount of adhesive is excessive and sticks out to the through hole side of the holder opening.

  The laser beam of Patent Document 1 that does not use a condenser lens is emitted at a relatively wide angle. Although this laser beam may hit the adhesive that protrudes from the opening edge, the wide-angle laser beam that is sufficiently divergent without using a condensing lens has a low power density, so the adhesive will change even if it hits the protruding adhesive. Never do. However, since the laser light hitting the phosphor is also converted into heat, the temperature of the phosphor plate itself rises. The heat of the phosphor plate is transmitted to the adhesive, and the adhesive in the portion sufficiently in contact with the holder ensures heat dissipation, so that the adhesive is not altered by heat. However, since the adhesive that protrudes and accumulates on the through-hole side of the holder opening end is not sufficiently in contact with the holder, the temperature of the protruding adhesive rises, and decomposition starts and blackens. Thereby, the incident efficiency of the laser beam to the phosphor plate is lowered, and the light extraction of the mixed color light is also deteriorated.

  In the case of the cited document 2, there is a problem that the material cost becomes high because a fixing member and a welding sleeve which are more expensive than the adhesive are used.

An object of the present invention is to provide a semiconductor light emitting device that can use an inexpensive adhesive for fixing a phosphor plate without being deteriorated by high-density laser light even if the adhesive protrudes into a through-hole.

To achieve the above object, an excitation light source including a semiconductor light emitting element, a condensing lens that condenses the excitation light emitted from the excitation light source, and a penetration through which the excitation light collected by the condensing lens passes. A holder portion provided with a hole, a first translucent member that converts the wavelength of excitation light that has passed through the through-hole, and a second translucent member that is positioned in the through-hole, The hole is composed of a small diameter portion, a medium diameter portion, and a large diameter portion in order from the excitation light source side, the diameter of the small diameter portion is smaller than the diameter of the medium diameter portion, and the diameter of the medium diameter portion is smaller than the diameter of the large diameter portion. The first translucent member is fixed with an adhesive on the holder portion of the medium diameter portion opposite to the excitation light source, and the second translucent member is spherical. , Fitted in a hole between the small-diameter portion and the medium-diameter portion, and excited and diverged by the condenser lens. Light passes through the second light transmitting member of said spherical, characterized in that it is irradiated to the first light-transmitting member.

  According to the first aspect of the present invention, the spherical second translucent member fitted in the through hole prevents the adhesive from protruding into the through hole on the excitation light source side even if the adhesive is used excessively. Therefore, the high-density excitation light condensed by the condenser lens does not directly hit the adhesive. The protruding adhesive is formed as a thin layer that flows along the side surface of the relatively wide through-hole without accumulating, and is heated by the holder portion that also serves as heat dissipation even when heated by excitation of the first light-transmissive member, The protruding adhesive does not change, the efficiency of incidence on the first light transmissive member, which is the wavelength conversion member, can be maintained, and the light extraction of white light is not reduced.

  According to a second aspect of the present invention, in the first aspect of the present invention, the focal point of the excitation light condensed by the condenser lens is the second light transmissive member on the excitation light source side and the excitation light source. And the condensing lens on the opposite side.

  According to the invention described in claim 2, since the focal point of the high-density excitation light condensed by the condenser lens is closer to the excitation light source side than the second light-transmissive member on the excitation light source side, the light is once condensed. Excitation light enters the through-hole while diverging and enters the second translucent member. The diverging light incident on the spherical second light transmissive member is refracted and the light that has passed through is converted into parallel light and irradiates the first light transmissive member. Since the through hole from the small diameter part to the medium diameter part becomes wider as it goes from the small diameter part to the medium diameter part, the parallel rays that have passed through the spherical second light-transmissive member are attached to the side surface of the through hole. It will not hit or change the adhesive.

  According to a third aspect of the present invention, in the first and second aspects of the present invention, the second translucent member is a translucent scatterer.

  According to the third aspect of the present invention, the excitation light once condensed is incident on the second translucent member mixed with the translucent scattering material fitted in the through hole while being diverged, thereby translucent. The excitation light is scattered by the scattering material, passes through the second light transmissive member, and spreads throughout the through hole. Since the scattered excitation light falls from a high power density to a low power density, the protruding adhesive does not change in quality. In addition, the excitation light impinging on the first translucent member is scattered by the second translucent member of the translucent scatterer, and compared with the second translucent member that does not include the translucent scattering material. Since the irradiation area is increased, the color unevenness of the mixed color light subjected to wavelength conversion by the first translucent member is reduced as compared with the second translucent member not including the translucent scattering material.

  According to a fourth aspect of the present invention, in the first to third aspects of the invention, the first light transmissive member and the second light transmissive member are spaced apart via an air layer. It is characterized by.

  According to the fourth aspect of the present invention, if the adhesive is filled in the through hole, the adhesive is denatured by the heat generated when the first translucent member is excited, and the excitation light Reduces the incident efficiency of. In order to prevent such a problem from occurring, it is desirable that the inside of the through hole between the first translucent member and the second translucent member is an air layer.

  According to a fifth aspect of the present invention, in the first to fourth aspects of the invention, the first translucent member is formed by laminating a scattering plate and a phosphor plate in order from the excitation light source side. To do.

  According to the fifth aspect of the present invention, the excitation light condensed and diverged by the condensing lens is divided into two stages by the second translucent member of the translucent scatterer and one translucent member of the scattering plate. Therefore, it is possible to scatter more widely than the light emitting device of the third claim which spreads only in one stage. Thereby, the intensity of the excitation light applied to the phosphor plate becomes uniform, and the color unevenness of the mixed color light emitted to the outside can be further improved.

  According to the present invention, since the adhesive does not protrude and accumulate in the through hole on the excitation light source side, the excitation light is incident on the first light-transmissive member without the adhesive being altered by high-density excitation light. It is possible to maintain the light extraction of the mixed color light emitted from the first translucent member for a long time without lowering the efficiency. Further, since an inexpensive adhesive can be used for fixing the first light transmissive member, the material cost for the semiconductor light emitting device can be reduced. Further, since it becomes possible to use an excessive amount of adhesive enough to spread the adhesive on the adhesive surface, the likelihood of manufacturing variation can be increased, and the reproducibility of the light extraction efficiency can be ensured and the first transparency can be ensured. The adhesive strength of the optical member can be ensured.

Sectional drawing cut | disconnected by the vertical surface containing the optical axis A of the semiconductor light-emitting device 1 FIG. 3 is an enlarged view of the vicinity of the through hole 7 of the semiconductor light emitting device 1 in the first embodiment of the present invention. Schematic of the bonding process of the first translucent member 9 Light image of excitation light in the first embodiment The enlarged view of the through-hole 7 vicinity in the 2nd Embodiment of this invention Enlarged view of the vicinity of the through hole 7 in the third embodiment of the present invention Enlarged view of the vicinity of the through hole 7 in the fourth embodiment of the present invention The enlarged view of the through-hole 7 vicinity in the 5th Embodiment of this invention The enlarged view of the through-hole 7 vicinity in the 6th Embodiment of this invention

  FIG. 1 is a cross-sectional view taken along a vertical plane including the optical axis A of the semiconductor light emitting device 1 according to the first embodiment of the present invention.

  As shown in FIG. 1, a semiconductor light emitting device 1 includes an excitation light source 3 including a semiconductor light emitting element 2, a condenser lens 4, a second light transmissive member 8, a first light transmissive member 9, and each of these elements. Holders (first holder 6, second holder 11, third holder 12) and the like. The excitation light source 3 of the present embodiment corresponds to a CAN package on which the semiconductor laser element 2 is mounted.

The first translucent member 9 is a phosphor plate, and converts the wavelength of light into light having a longer wavelength than the excitation light of the excitation light source. The material of the phosphor plate may be a plate made of a composite of YAG and Al ₂ O ₃ into which an activator such as Ce is introduced, or a glass binder or other material instead of Al ₂ O ₃ It may consist of materials.

The phosphor layer of this embodiment uses a plate material (0.4 mm × 0.8 mm rectangular plate shape) made of a composite of YAG and Al ₂ O ₃ into which an activator such as Ce is introduced. The thickness of the phosphor plate was 200 μm. However, since it is necessary to adjust the chromaticity to a desired value depending on the application, the thickness of the phosphor layer is appropriately changed within the range of 50 to 300 μm depending on the phosphor concentration. The first light transmissive member is not limited to a rectangular plate shape, and may be a cylinder or a rectangular parallelepiped.

  The first holder 6 is a member for holding the first translucent member 9, and emits from a metal cylindrical tube portion 6b made of a highly heat conductive material such as stainless steel or aluminum, and the semiconductor light emitting element. A through hole 7 is formed in the thickness direction in the center of the first holder 6 on the optical axis of the laser beam.

  FIG. 2 shows an enlarged view of the vicinity of the through hole 7 of the semiconductor light emitting device 1. As shown in FIG. 2, the through-hole 7 is a hole through which the excitation light condensed and diverged by the condenser lens 4 passes, and a small-diameter portion 7 a on the excitation light source 3 side and a large-diameter portion on the opposite side to the excitation light source 3. 7d, a medium diameter portion 7c located between the small diameter portion 7a and the large diameter portion 7d, and a hole having three different calibers. The diameter size of the small diameter portion 7a is smaller than the medium diameter portion 7c, and the diameter size of the medium diameter portion 7c is smaller than the large diameter portion 7d. In the first embodiment, the hole from the small diameter portion 7a to the medium diameter portion 7c is gradually widened in an inclined manner toward the opposite side of the excitation light source. The hole of the large diameter portion 7d is stepped. That is, the through hole 7 of the first embodiment has a cross-sectional structure in which an inclined hole extending from the small diameter portion 7a to the medium diameter portion 7c and a stepped hole having a diameter size of the large diameter portion 7d are connected. .

  The 1st translucent member 9 is being fixed to the adhesion surface 14 on the opposite side to the excitation light source 3 of the intermediate diameter part 7c with the adhesive agent. A reflective film made of Ag, Al, or an alloy containing these is formed on the adhesive surface 14 or the side surface of the through hole 7 (not shown). The diameter of the medium diameter portion 7 c is made smaller than the size of the first light transmissive member 9 in consideration of the excitation light leakage and the incident efficiency to the first light transmissive member 9. The diameter of the medium diameter portion 7c of this embodiment is Φ200 μm, but since the minimum width of the phosphor plate is 400 μm, Φ100 μm to Φ400 μm can be appropriately selected. The size of the small-diameter portion 7a is set to double Φ100 μm in consideration of the size of the excitation light incident on the small-diameter portion 7a being about Φ50 μm and the optical axis accuracy and processing accuracy, but Φ50 to 300 μm can be appropriately selected. is there.

The spherical second light transmissive member 8 is fitted in an inclined hole from the small diameter portion 7a to the medium diameter portion 7c on the opposite side to the excitation light source 3. As the material of the spherical second light transmissive member 8, glass SiO ₂ , alumina Al ₂ O ₃ , titanium oxide TiO ₂ , or a mixture of at least one of these materials was used. Although glass beads are used in the embodiment of the present invention, bending of excitation light can be increased by using alumina or titanium oxide having a high refractive index. As for the diameter size of the 2nd translucent member 8, the minimum was 10% or more of the diameter of the small diameter part 7a, and the maximum was 10% or less of the medium diameter part. This is to prevent the second translucent member from protruding from the through hole. In this embodiment, a size of Φ120 is used.

  The first translucent member 9 is fixed to the adhesive surface 14 of the medium diameter part 7c opposite to the excitation light source 3 with an adhesive. As the adhesive 13, a silicone-based resin that is relatively strong in heat resistance and light resistance is used. In the embodiment of the present invention, a dimethyl silicone resin is used. The adhesive was applied by a dispenser 15 that can accurately control the discharge amount.

  FIG. 3 shows the bonding process of the first light transmissive member 9. As shown in FIG. 3A, first, the spherical second translucent member 8 is fitted into the through hole 7b. The spherical second translucent member 8 was fixed by applying a small amount of adhesive to the dam 16 (not shown).

  As shown in FIG. 3B, the linear shape of the similar shape of the first translucent member 9 is provided at approximately the middle position of the surface where the first translucent member 9 and the adhesive surface 14 are contacted by the dispenser 15. Adhesive 13 is applied to (not shown). The amount of the adhesive material is larger than the amount necessary for the first light-transmissive member 9 and the adhesive surface 14, and in this embodiment, the amount is increased by 50% and applied excessively.

  As shown in FIG. 3C, the first translucent member 9 is placed, and the first adhesive member 13 is spread over the entire surface that the first translucent member 9 contacts with a uniform thickness. A load is applied from above the translucent member 9.

  As shown in FIG. 3D, the adhesive 13 is formed on the side surface of the through hole 7b as a thin film 13b, and the spherical second translucent member 8 and the side surface of the through hole are in contact with each other even if it flows down the inclined surface. The adhesive 13 stops at the damming portion 16. When the adhesive 13 that reaches the damming portion 16 is always used, the trace amount of adhesive used in FIG. 3A may be omitted. Although the viscosity of the adhesive 13 of the embodiment of the present invention is 1 Pa · s, it may be 0.3 to 10 Pa · s, preferably 0.5 to 3 Pa · s. The adhesive was cured by setting the first holder in a thermostat and curing at 150 ° C. for 4 hours. If you want to adjust more accurately than the thickness of the adhesive that has flowed to the side of the through hole 7b, maintain the temporary curing temperature at 60 ° C for 30 minutes, which increases the fluidity of the adhesive, and then increase the temperature to 150 ° C, the main curing temperature Is good. The temporary curing temperature may be 50 ° C to 80 ° C.

  As shown in FIG. 3D, the adhesive used for fixing the first light transmissive member 9 stops at the damming portion 16 of the spherical second light transmissive member 8, so that the small-diameter portion on the excitation light source 3 side. It is possible to prevent the adhesive from protruding and accumulating to 7a and to be exposed to the excitation light 17 collected at high density. Conventionally, a low-viscosity adhesive could not be selected considering the protrusion of the adhesive 13, but in the present invention, there is no concern that the adhesive 13 may be exposed to excitation light even if it protrudes. It is possible to select a low-viscosity adhesive that easily reaches one translucent member 9.

  A light reflecting member 10 is buried around the phosphor plate of the first translucent member 9. The light reflecting member 10 uses a white resin prepared by mixing high refractive index submicron sized particles such as titanium oxide, barium sulfate or zinc oxide with a silicone resin. The surrounding area was filled and then heated to be cured. Since this light reflecting member 10 serves to reflect the excitation light and wavelength converted light leaking from the first light transmissive member 9 and to extract the light upward from the first light transmissive member, the luminance is improved. Can do. If the light reflecting member 10 is formed to be sufficiently thick, the stepped portion having the large diameter portion 7d may be omitted.

  FIG. 4 shows a light beam image of the excitation light in the first embodiment. By placing the focal point 18 of the high-density excitation light 17 collected by the condenser lens 4 near the spherical second light-transmissive member 8 on the excitation light source 3 side, the once-extracted excitation light 17 diverges. However, it is incident on the spherical second translucent member 8. The divergent light incident on the spherical second light transmissive member 8 passes through while being refracted and becomes almost parallel light, and irradiates the first light transmissive member. Since the diameter of the inclined hole extending from the small diameter part 7a to the medium diameter part 7c becomes wider toward the first translucent member 9 side, the adhesive 13b adhering thinly to the side surface of the through hole 7b. The light beam traveling toward is significantly reduced by the light collecting action of the spherical second translucent member 8. Therefore, the adhesive 13b is not altered. The parallel light beam emitted from the spherical second light transmissive member 8 is incident on the phosphor plate, which is the first light transmissive member 9, is converted in wavelength, and is mixed with the partially transmitted excitation light so that white light is emitted to the outside. discharge. When excitation light hits the phosphor plate, part of the energy is converted into heat, so the temperature of the phosphor plate rises and the adhesive 13 also heats up, but the adhesive formed on the side surface of the through hole 7b is Since it is thin and in close contact, heat is radiated from the holder 6a, and the adhesive is not altered by heat.

  By selecting alumina, titanium oxide or the like having a high refractive index by using the spherical second translucent member 8, it becomes possible to increase the refraction of the incident excitation light, so that a larger sphere or flat shape can be obtained. It is also possible to design an aspherical surface.

  Thereby, the excitation light 17 condensed by the condenser lens 4 becomes divergent light after being condensed at the focal point 18. Since the divergent light enters the through-hole 7 and can be refracted more greatly by the spherical second light-transmissive member 8 to narrow the width of the parallel light, all the light is incident on the first light-transmissive member 9. can do. It is also possible to make the width of the diverging light wider by moving the position of the focal point 18 of the condenser lens 4 further away from directly below the lower surface of the holder 6a on the excitation light source side.

  In the through-hole 7b, there is nothing but a so-called air layer other than the protruding adhesive 13b formed as a thin layer on the side surface. If the inside of the through-hole 7b is filled with an adhesive, the adhesive is altered by the heat generated from the phosphor excited by the laser beam, and the incident efficiency of the excitation light on the first light-transmissive member 9 is increased. This is because it is considered to decrease. For this reason, it is better that an air layer is formed between the first translucent member and the second translucent member. The apex of the spherical second light transmissive member 8 on the side opposite to the excitation light source 3 may be in contact with the surface of the first light transmissive member 9 on the excitation light source side. Since it is necessary to consider the positional accuracy of the two translucent members, it is better to design the first and second translucent members so as not to contact each other, considering the ease of assembly.

  FIG. 5 is a sectional view of a modified example of the through hole 7 in the first embodiment in the second embodiment of the present invention.

  As shown in FIG. 5, the through hole 7 is a hole through which the excitation light from the condenser lens 4 passes, and from the excitation light source 3 side toward the opposite side of the excitation light source 3, the small diameter portion 7 a, the medium diameter portion 7 c, and the large diameter. The small-diameter portion 7a has a diameter size smaller than that of the medium-diameter portion 7c, and the medium-diameter portion 7c has a diameter size smaller than that of the large-diameter portion 7d. The through-hole 7 has a cross-sectional structure in which three holes having sizes of a small diameter portion 7a, a medium diameter portion 7c, and a large diameter portion 7d are connected in a step shape. The spherical second translucent member 8 is fitted in a stepped hole in the small diameter portion 7a on the opposite side to the excitation light source 3. The first translucent member 9 is fixed with an adhesive 13 on the upper surface of the stepped hole in the medium diameter portion 7 c on the opposite side to the excitation light source 3.

  FIG. 6 is a cross-sectional view of a modification of the through hole 7 in the first embodiment according to the third embodiment of the present invention.

  As shown in FIG. 6, the through-hole 7 is a hole through which the excitation light from the condenser lens 4 passes, and the incident portion 7 e, the small diameter portion 7 a, and the medium diameter portion from the excitation light source 3 side to the opposite side of the excitation light source 3. 7c and the large diameter portion 7d. The incident portion 7e is wider than the small diameter portion 7a, the diameter size of the small diameter portion 7a is smaller than the medium diameter portion 7c, and the diameter size of the medium diameter portion 7c is smaller than the large diameter portion 7d. It has become. The through-hole 7 is inclined between the incident portion 7e and the small diameter portion 7a, is inclined between the small diameter portion 7a and the medium diameter portion 7c, and is formed between the medium diameter portion 7c and the large diameter portion 7d. The gaps are connected in steps. The spherical second translucent member is fitted on the upper surface of the small-diameter portion opposite to the excitation light source 3 between the small-diameter portion 7a and the medium-diameter portion 7c.

  Although the high-density excitation light condensed by the condenser lens diverges at the focal point 18, the positional accuracy, processing accuracy, and assembly accuracy of the semiconductor laser element 2, the excitation light source 3, the condenser lens 4, and the through hole 7 are low. For example, a part of the diverging excitation light hits the first holder surface around the through-hole 7 on the excitation light source 3 side, and there is a concern that the incident efficiency to the through-hole 7 is lowered. Therefore, as in the third embodiment, if the incident portion 7e is formed so as to gradually widen from the incident portion 7e to the small diameter portion 7a, the likelihood of these accuracy can be increased, and the semiconductor light emitting device can be easily assembled. Is possible.

  FIG. 7 is a cross-sectional view of a modification of the spherical second light transmissive member 8 in the first embodiment according to the fourth embodiment of the present invention.

As shown in FIG. 7, the through-hole 7 has the same shape as that of the first embodiment. The spherical second translucent member 19 is mixed with a translucent scattering material for diffusing light. In the present embodiment, 25 wt% of Al ₂ O ₃ particles are mixed into the base glass. The scattering material only needs to have a higher refractive index than the base material such as TiO ₂ . The spherical second translucent member 19 containing the translucent scattering material is fitted on the upper surface of the small-diameter portion opposite to the excitation light source 3 between the small-diameter portion 7a and the medium-diameter portion 7c.

The once-extracted excitation light is incident on the second translucent member 19 mixed with the translucent scattering material fitted in the through hole 7, and the translucent scattering contained in the second translucent member 19. The excitation light is scattered by the material and spreads in the through hole 7b. Since the scattered excitation light changes from a high density to a low density, the protruding adhesive 13b is not altered. The temperature of the first translucent member is increased by the excitation light and the adhesive is also heated, but the protruding adhesive 13b flows along the side surface of the through-hole 7b and adheres as a thin layer. The agent 13b is heated by the holder portion that also serves as heat dissipation, and does not decompose or deteriorate. Furthermore, since the excitation light impinging on the first translucent member 9 is scattered by the second translucent member 19 of the translucent scatterer and then irradiates the first translucent member 9, the translucent scattering material Compared with the second translucent member 8 that does not contain the light, the irradiation area is widened, and the color unevenness of the mixed color light subjected to wavelength conversion by the first translucent member 9 does not include the translucent scattering material. Compared with the second translucent member 8, the second translucent member 19 of the translucent scatterer is better.
In the fourth embodiment, the through hole 7 has the same shape as that of the first embodiment, but the same effect can be obtained with the shape of the through hole used in the second embodiment or the third embodiment. be able to.

  FIG. 8 is a cross-sectional view of a modification of the first light transmissive member 9 in the fourth embodiment according to the fifth embodiment of the present invention.

As shown in FIG. 8, the through hole 7 is the same as that of the fourth embodiment, but the first translucent member is formed by laminating the phosphor plate 9a and the diffusion plate 9b, and the excitation light source 3 side. To the diffusion plate 9b and the phosphor plate 9a. As the diffusion plate 9b, a plate obtained by mixing 12.5 wt% Al ₂ O ₃ particles serving as a scattering material into a base glass and molding it into a plate shape (thickness 400 μm) was used. The phosphor plate 9a has the same composition as that described in Embodiment 1 (thickness 80 μm). The shape and size are the same as those in the first embodiment. The spherical second translucent member 19 mixed with the translucent scattering material is made of the same material, but the concentration of the scattering material is 12.5 wt%. That is, in this embodiment, the concentration of the scattering material of the spherical second light-transmitting member 19 mixed with the light-transmitting scattering material and the diffusion plate 9b are added to obtain the concentration of the fourth embodiment. did. This is because when the scattering material concentration is too high, backscattering by the scattering material also increases, and the incident efficiency of excitation light impinging on the phosphor plate is prevented from being lowered. In order to control the chromaticity and color unevenness of the mixed color light emitted to the outside from the phosphor plate, the scattering material concentration and thickness of the second translucent member 19 and the diffusion plate 9b are adjusted, or the fluorescence of the phosphor plate Needless to say, adjustment of body concentration and size is necessary.

  The once-extracted excitation light enters the second light transmissive member 19, is scattered by the mixed light transmissive scattering material, and spreads in the through hole 7b. When the excitation light spreading in the through hole 7b enters the diffusion plate 9b, the excitation light spreads beyond the diameter of the medium diameter portion 7c and irradiates the entire surface of the phosphor plate 9a without unevenness in intensity. Although the total concentration of the scattering material is the same as that in the fourth embodiment, the excitation light spreads in two stages of the second translucent member 19 and the diffusion plate 9b having a thickness of 400 μm through the air layer. Compared with the fourth embodiment having only one stage of scattering by the translucent member, the spread of the excitation light is large and the in-plane intensity is uniform, and the color unevenness of the mixed color light emitted from the phosphor plate 9a to the outside. Will be better.

In the fifth embodiment, the second translucent member 19 may not include a translucent scattering material, but in this case, since the scattering material concentration of the diffusion plate 9b is increased, color unevenness is caused. The improvement effect cannot be expected as much as the second translucent member 19 including the translucent scattering material.
Moreover, although the same shape as 1st Embodiment was used for the through-hole 7, the same effect can be acquired even if it is the through-hole shape used in 2nd Embodiment or 3rd Embodiment.

  FIG. 9 is a cross-sectional view of a modification of the second light transmissive member 20 in the first embodiment in the sixth embodiment. As shown in FIG. 9, the second translucent member is changed from spherical to aspherical. In the case of the second translucent member 20 that does not include the translucent scattering material, the aspherical shape is designed so that the excitation light incident only on the curved surface on the side of the excitation light source 3 can be changed into parallel rays. Thus, the same effect as that of the first embodiment is obtained. In the case of the second translucent member including the translucent scattering material, secondly, since the light incident on the translucent member 20 becomes scattered light, if it is processed or molded into a curved surface shape As an effect, the same effect as that of the fourth embodiment can be obtained.

  DESCRIPTION OF SYMBOLS 1 ... Light-emitting device, 2 ... Semiconductor light-emitting device, 3 ... Excitation light source, 4 ... Condensing lens, 5 ... Feed part, 6 ... 1st holder, 7 ... Through-hole , 8 ... second translucent member, 9 ... first translucent member, 10 ... light reflecting member, 11 ... second holder, 12 ... third holder , 13 ... Adhesive, 14 ... Adhesive surface, 15 ... Dispenser, 16 ... Damping part, 17 ... Excitation light, 18 ... Focus, 19 ... Translucent scattering material Entering second translucent member, 20 ... aspherical second translucent member

Claims (5)

A holder provided with an excitation light source including a semiconductor light emitting element, a condensing lens for condensing the excitation light emitted from the excitation light source, and a through-hole through which the excitation light condensed by the condensing lens passes; A first translucent member that converts the wavelength of the excitation light that has passed through the through-hole, and a second translucent member that is located in the through-hole,
The through hole is composed of a small diameter portion, a medium diameter portion, and a large diameter portion in order from the excitation light source side, the diameter of the small diameter portion is smaller than the diameter of the medium diameter portion, and the diameter of the medium diameter portion is that of the large diameter portion. Smaller than the aperture,
The first translucent member is fixed with an adhesive on a holder part of the medium diameter part opposite to the excitation light source,
The second translucent member has a spherical shape and is fitted in a hole between the small diameter portion and the medium diameter portion,
The semiconductor light emitting device, wherein the excitation light condensed and diverged by the condensing lens is irradiated to the first light transmissive member after passing through the spherical second light transmissive member.   2. The invention according to claim 1, wherein the focal point of the excitation light condensed by the condenser lens is the second translucent member on the excitation light source side and the condenser lens on the opposite side of the excitation light source. A semiconductor light-emitting device, which is located between the two.   3. The semiconductor light emitting device according to claim 1, wherein the second light transmissive member is a light transmissive scatterer.   4. The semiconductor light emitting device according to claim 1, wherein the first light transmissive member and the second light transmissive member are separated from each other through an air layer.   5. The semiconductor light emitting device according to claim 1, wherein a scattering plate and a phosphor plate are stacked in order from the excitation light source side.

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