JP2006303038A - Light emitting device and lighting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting device which efficiently excites a fluorescent substance in a wavelength converting member and has high optical output and high luminance, and which is superior in light emitting efficiency. <P>SOLUTION: The light emitting device is provided with a substrate 1 wherein a light emitting element 3 is placed on its upper surface; a frame-like reflection member 2 whose internal peripheral surface is used for a light reflection surface 2a; a first light transmitting member 5 which is provided inside the reflection member 2 so as to cover the light emitting element 3; an optical member 6 whose refractive index is larger than that of the first light transmitting member 5 and wherein a diffraction lattice made of a plurality of convexes or recesses is formed on at least either of the upper main surface and the lower main surface thereof, and which is fitted in a manner to cover the first light transmitting member 5; a second light transmitting member 7 whose refractive index is smaller than that of the optical member 6, and which is fitted in a manner to cover the optical member 6; and a wavelength converting member 4 whose refractive index is larger than that of the second light transmitting member 7, and which is arranged so as to cover the second light transmitting member 7 and includes a fluorescent substance that generates fluorescence when it is excited by a light emitted from the light emitting element 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a light emitting device in which a light emitting element is accommodated and an illumination device using the same.

  A conventional light emitting device is shown in FIG. In FIG. 7, 11 is a base, 12 is a reflecting member, 13 is a light emitting element, 15 is a translucent member disposed inside the reflecting member 12 so as to cover the light emitting element 13, and 14 is a translucent member 15. It is a wavelength conversion member that contains a phosphor (not shown) that emits fluorescence by converting the wavelength of light emitted by the light-emitting element 13 disposed above, and mainly for housing the light-emitting element 13 with these. A light emitting device is configured.

  The base body 11 is made of an insulator, and a wiring conductor 11b is formed with one end portion led out to the mounting portion 11a on which the light emitting element 13 is mounted at the center portion of the upper surface and the other end portion led out to the side surface or the lower surface of the base body 11. The The base 11 is attached with a frame-like reflecting member 12 whose inner peripheral surface is a light reflecting surface 12a so as to surround the mounting portion 11a on the upper surface.

  Further, the light emitting element 13 is placed on the placement portion 11 a so as to be electrically connected to the wiring conductor 11 b via the conductive member 18.

  The translucent member 15 is formed so as to cover the light emitting element 13 on the inner side of the reflecting member 12, and above the translucent member 15, a fluorescent light that is excited by light emitted from the light emitting element 13 to generate fluorescence. A wavelength conversion member 14 containing a body is disposed.

  As a result, a light emitting device capable of converting the wavelength of light from the light emitting element 13 by the phosphor and extracting light of a desired wavelength spectrum can be obtained. In particular, when the light from the light-emitting element 13 and the phosphor are in a complementary color relationship, white light can be emitted.

  This light emitting device can cause the light emitting element 13 to emit light by a drive current supplied from an external electric circuit and emit visible light whose wavelength has been converted by the wavelength conversion member 14.

  In recent years, practical application of a light emitting device that can excite a phosphor contained in the wavelength conversion member 14 by visible light or near ultraviolet light emitted from the light emitting element 13 and convert it into a desired wavelength spectrum to emit visible light. Is progressing. Such light-emitting devices have begun to be used as illumination light sources, and studies have been actively conducted on improving the light emission efficiency and color characteristics.

In particular, in recent years, in order to improve the light emission efficiency of the light emitting device, improvement of the light emission efficiency (wavelength conversion efficiency) of the phosphor contained in the wavelength conversion member has begun to be studied.
JP 2000-349346 A

  However, in the conventional light emitting device, the light emitted from the light emitting element 13 is confined in the light transmissive member 15 by total reflection due to the refractive index difference between the light transmissive member 15 and the wavelength conversion member 14, and efficiently. There is a problem that the light output of the light emitting device is deteriorated because the light cannot enter the wavelength conversion member 14.

  In addition, the light from the light emitting element 13 incident on the wavelength conversion member 14 from the translucent member 15 has a refractive index of the translucent member 15 and the wavelength conversion member 14 according to the incident angle incident on the wavelength conversion member 14. Due to refraction due to the difference, the light path in the wavelength conversion member 14 changes and the optical path length of the light propagating from the lower side to the upper side of the wavelength conversion member 14 is not constant. As a result, phosphors dispersed from the upper side to the upper side cannot be excited efficiently and uniformly, causing color unevenness on the light emitting surface and irradiation surface of the light emitting device, and deterioration of light output. Was.

  As described above, in the conventional light emitting device, it is difficult to improve the light output and luminance of the light emitting device due to refraction and total reflection due to the refractive index difference between the translucent member 15 and the wavelength conversion member 14. There was a problem that there was.

  Accordingly, the present invention has been completed in view of the above-described conventional problems, and the object thereof is to efficiently guide the light emitted from the light emitting element into the wavelength conversion member, and to efficiently convert the phosphor in the wavelength conversion member. It is an object of the present invention to provide a light emitting device having a large light output and high luminance and high luminous efficiency.

  The light-emitting device of the present invention includes a base on which a light-emitting element is mounted on an upper surface, and a frame-shaped reflecting member attached to the upper surface of the base so as to surround the light-emitting element and having an inner peripheral surface as a light reflecting surface A first translucent member provided so as to cover the light emitting element inside the reflecting member, a refractive index equal to or higher than a refractive index of the first translucent member, and an upper main surface and A diffraction grating composed of a plurality of convex portions or concave portions is formed on at least one of the lower main surface, and an optical member attached so as to cover the first translucent member, and a refractive index of the optical member A second light-transmitting member that is smaller and attached to cover the optical member, and a refractive index that is larger than that of the second light-transmitting member and that covers the second light-transmitting member. And a phosphor that generates fluorescence when excited by light emitted from the light emitting element. Characterized by comprising a and a wavelength conversion member.

  In the light emitting device of the present invention, preferably, the plurality of convex portions or concave portions have an outer peripheral diameter of φ, a height or a depth of T, an interval between the convex portions or concave portions of S, and the light emitting elements emit light. When the center wavelength of light is λ, λ / 10 ≦ φ ≦ 10λ, λ / 3 ≦ T ≦ 3λ, and λ / 10 ≦ S ≦ 10λ are satisfied.

  The illuminating device of the present invention includes the light emitting device of the present invention as a light source.

  In the light emitting device of the present invention, a diffraction grating composed of a plurality of convex portions or concave portions is formed on at least one of the upper main surface and the lower main surface, which is attached to the surface so as to cover the first translucent member. The optical member is arranged to cover the optical member via a second light-transmitting member having a refractive index smaller than that of the optical member, and is excited by light emitted from the light emitting element to generate fluorescence. And a wavelength conversion member having a refractive index greater than that of the second translucent member, including the body, from the light emitting element to the optical member via the first translucent member or the light reflecting surface of the reflective member. The incident light is propagated to the second light transmissive member as diffracted light of the optical member and is incident on the wavelength conversion member. Therefore, the light transmitted through the optical member can be incident on the lower surface of the wavelength conversion member with a small incident angle. As a result, the diffracted light diffracted by the optical member is more incident on the wavelength conversion member without being totally reflected on the lower surface of the wavelength conversion member, and the phosphor contained in the wavelength conversion member is efficiently made from the lower side to the upper side. Since it is excited well, the fluorescence generated from the phosphor of the wavelength conversion member increases and the light output of the light emitting device increases.

  Further, among the light emitted from the wavelength conversion member, the light emitted in the inner direction of the light emitting device has a refractive index larger than the refractive index of the second light transmissive member and the second light transmissive property. Total reflection is performed according to Snell's law at the interface with the member. Since the totally reflected light is reflected upward and output from the light emitting device, the light output of the light emitting device can be extremely effectively increased and the light emission efficiency can be improved.

  In the light emitting device of the present invention, preferably, the plurality of convex portions or concave portions have an outer peripheral diameter of φ, a height or a depth of T, an interval between the convex portions or concave portions of S, and the light emitting element. When the center wavelength of emitted light is λ, λ / 10 ≦ φ ≦ 10λ, λ / 3 ≦ T ≦ 3λ, and λ / 10 ≦ S ≦ 10λ are satisfied, so that light passing through the optical member is effectively diffracted. Thus, the incident angle of the second translucent member can be made smaller than the incident angle of the optical member.

  Since the illumination device of the present invention includes the light-emitting device of the present invention as a light source, the illumination device can have a high radiated light intensity and high brightness.

The light emitting device of the present invention will be described in detail below.
FIG. 1 is a cross-sectional view showing an example of an embodiment of a light emitting device of the present invention. In this figure, 3 is a light emitting element, 1 is a substrate on which the light emitting element 3 is mounted, 2 is a frame-like reflecting member whose inner peripheral surface is a light reflecting surface 2a, and 5 is inside the reflecting member 2 The first translucent member 6 provided so as to cover the light emitting element 3 has a refractive index equal to or higher than the refractive index of the first translucent member 5 and at least one of the upper main surface and the lower main surface. A diffraction grating composed of a plurality of convex portions or concave portions is formed, an optical member attached so as to cover the first translucent member 5, and a refractive index 7 is smaller than that of the optical member 6. The second translucent member 4 attached so as to cover is larger in refractive index than the second translucent member 7 and is disposed so as to cover the second translucent member 7. 3 is a wavelength conversion member containing a phosphor (not shown) that is excited by the light emitted by 3 to generate fluorescence. Emitting device is formed that houses the light-emitting element 3 at these. FIG. 1 schematically shows a case where a diffraction grating composed of a plurality of convex portions or concave portions is formed only on the upper main surface of the optical member 6.

  The substrate 1 is an insulator made of an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, ceramics such as glass ceramics, or a resin such as epoxy resin, and supports the light emitting element 3. It functions as a member, and the light emitting element 3 is mounted on the upper surface.

  The substrate 1 is formed with a wiring conductor 1b made of a metal such as tungsten (W), molybdenum (Mo), manganese (Mn), copper (Cu), etc. in order to electrically connect the inside and outside of the light emitting device. ing. Then, the light emitting element 3 is electrically connected to one end of the wiring conductor 1b on the upper surface of the base 1, and the external electric circuit board is electrically connected to the other end of the wiring conductor 1b led out to the side surface or the lower surface of the base 1. Thus, the external electric circuit board and the light emitting element 3 can be electrically connected. Such a wiring conductor 1b is formed using a known metallizing method, plating method or the like.

  In addition, the wiring conductor 1b has a metal layer excellent in corrosion resistance, such as a nickel (Ni) layer having a thickness of 0.5 to 9 μm and a gold (Au) layer having a thickness of 0.5 to 5 μm, attached to the exposed surface of the substrate 1. As a result, the wiring conductor 1b can be effectively prevented from being oxidatively corroded, and the bonding of the light emitting element 3 with the conductive member 8 such as solder can be strengthened.

  In addition, the base body 1 has an upper surface that suppresses the light emitted from the light emitting element 3 from being transmitted to the lower surface of the base body 1 and efficiently reflects the light above the base body 1 with respect to the wiring conductor 1b. In order to prevent electrical short circuit, a metal layer such as aluminum (Al), silver (Ag), Au, platinum (Pt), or Cu is formed by vapor deposition or plating, and light is reflected above the substrate 1. A reflective layer is preferably provided.

  When the substrate 1 is made of ceramics or the like, the wiring conductor 1b made of a metal paste such as W or Mo-Mn is formed on a plurality of green sheets to be the substrate 1, and the substrate 1 is fired and the metal paste is fired at the same time. Thus, the base body 1 having the wiring conductor 1b is formed.

  Further, as shown in FIG. 1, the base 1 surrounds the mounting portion 1a of the light emitting element 3 on its upper surface, and reflects light from the light emitting element 3 or fluorescence from the phosphor on its inner peripheral surface. The reflecting member 2 having the surface 2a is made of a metal brazing material such as Ag-Cu, lead (Pb) -tin (Sn), Au-Sn, Au-silicon (Si), Sn-Ag-Cu, solder having a low melting point, It is attached with a bonding material (not shown) such as a silicone or epoxy resin bonding agent. Thereby, while protecting the light emitting element 3 from an external environment, the wavelength conversion member 4, the 1st translucent member 5, and the optical member 6 can be hold | maintained.

  The bonding material may be appropriately selected in consideration of the material of the base 1 and the reflection member 2, the thermal expansion coefficient, and the like, and is not particularly limited. Further, when high reliability of bonding between the base 1 and the reflecting member 2 is required, it is preferable to bond with a metal brazing material or solder.

  The reflection member 2 may be formed integrally with the base body 1. For example, when the base body 1 and the reflection member 2 are made of ceramics, a ceramic green sheet to be the base body 1 and a ceramic green sheet to be the reflection member 2 are laminated. It can be formed by firing at the same time.

  Further, the reflecting member 2 has a light reflecting surface 2 a whose inner peripheral surface efficiently reflects the light emitted from the light emitting element 3. Since the light reflecting surface 2a is formed around the light emitting element 3, the light emitted from the light emitting element 3 is efficiently reflected above the light emitting device, and the emitted light intensity and luminance of the light emitting device can be remarkably improved. .

  The light reflecting surface 2a includes a reflecting member 2 made of a highly reflective metal such as Al, Ag, Au, Pt, titanium (Ti), chromium (Cr), Cu, ceramics such as white, or resin such as white. It is formed by machining by cutting or mold forming. Alternatively, the light reflecting surface 2a may be formed on the inner peripheral surface of the reflecting member 2 by forming a metal thin film such as Al, Ag, Au or the like by metal plating or vapor deposition. In addition, when the light reflecting surface 2a is made of a metal that is easily discolored by oxidation such as Ag or Cu, an inorganic substance such as a low-melting glass or sol-gel glass having excellent transmittance from the ultraviolet light region to the visible light region, It is better to deposit organic substances such as silicone resin and epoxy resin. As a result, the corrosion resistance, chemical resistance, and weather resistance of the light reflecting surface 2a are improved.

  Moreover, as shown in FIG. 2, the light reflecting surface 2a is preferably inclined so as to spread outward as it goes upward. Thereby, the light emitted from the light emitting element 3 can be efficiently reflected upward of the light emitting device. The arithmetic average roughness Ra of the light reflecting surface 2a is preferably 4 μm or less. Thereby, it can reflect favorably above the light emitting device. When Ra exceeds 4 μm, it becomes difficult to reflect the light of the light emitting element 3 by the light reflecting surface 2a and to emit the light upward from the light emitting device, and the light easily diffuses inside the light emitting device. As a result, the propagation loss of light inside the light emitting device tends to increase, and it becomes difficult to emit light efficiently outside the light emitting device.

  Further, when the arithmetic mean roughness Ra is less than 0.004 μm, it is difficult for the light reflecting surface 2a to form such a surface stably and efficiently, and the product cost tends to increase. Therefore, the arithmetic average roughness of the light reflecting surface 2a is more preferably 0.004 to 4 μm.

  In order to make Ra within the above range, it may be formed by a conventionally known electrolytic polishing process, chemical polishing process or cutting polishing process. Further, a method of forming by transfer processing using the surface accuracy of the mold may be used.

  The light reflecting surface 2a may be flat (straight) as shown in FIG. 1, or may be arcuate (curved). In the case of the circular arc shape, the light from the light emitting element 3 can be condensed and light with high directivity can be uniformly emitted upward.

  The light emitting element 3 may have any peak wavelength of energy to be emitted from the ultraviolet region to the infrared region, but from the viewpoint of emitting white light or light of various colors with good visibility, a near ultraviolet light of 300 to 500 nm. To an element that emits blue light. For example, a buffer layer composed of gallium (Ga) -nitrogen (N), Al-Ga-N, indium (In) -GaN, etc., an N-type layer, a light-emitting layer, and a P-type layer are sequentially stacked on a sapphire substrate. A gallium nitride compound semiconductor or a silicon carbide (SiC) compound semiconductor is used.

  The light-emitting element 3 is made of a bump using a brazing material such as Au-Sn, Sn-Ag, Sn-Ag-Cu or Sn-Pb or solder, or a bump using a metal such as Au or Ag. It is electrically connected to the wiring conductor 1b via the conductive member 8 by flip chip mounting. Alternatively, for example, a conductive member 8 made of a solder material such as paste Au—Sn or Pb—Sn or Ag paste is placed on the wiring conductor 1 b using a dispenser or the like, and is electrically connected to the electrode of the light emitting element 3. The light emitting element 3 is mounted so that the upper surface of the conductive member 8 is in contact, and then the whole is heated at about 250 ° C. to 350 ° C., whereby the electrode of the light emitting element 3 and the wiring conductor 1b are electrically connected by the conductive member 8. For example, a method of manufacturing a connected light emitting device.

  The light emitting element 3 is mounted on the mounting portion 1 a and electrically connected to the wiring conductor 1 b via the conductive member 8, and then the transparent first light transmitting property inside the reflecting member 2. Covered by member 5.

  The first translucent member 5 has a small refractive index difference from the light emitting element 3 and has a high transmittance with respect to light in the ultraviolet light region to the visible light region, such as a transparent resin such as a silicone resin, an epoxy resin, or a urea resin. It is made of transparent glass such as low melting point glass and sol-gel glass.

  The first light transmissive member 5 may be appropriately selected in consideration of the material of the base 1, the thermal expansion coefficient, and the like, and is not particularly limited. This effectively suppresses occurrence of light reflection loss at the interface between the light emitting element 3 and the first light transmissive member 5 due to the difference in refractive index between the light emitting element 3 and the first light transmissive member 5. Therefore, light can be efficiently extracted from the inside of the light emitting element 3. In addition, the 1st translucent member 5 is formed by methods, such as thermosetting after apply | coating so that the light emitting element 3 may be coat | covered inside the reflection member 2 with injectors, such as a dispenser.

And the 1st translucent member 5 has the high transmittance | permeability with respect to the light of the transparent member (not shown) same as the 1st translucent member 5 on the upper surface, ie, the ultraviolet region, and the visible region. An uncured transparent member made of a transparent resin such as a silicone resin, an epoxy resin, or a urea resin, or a transparent glass such as a low-melting glass or a sol-gel glass is applied, and the first translucent member 5 is applied through this transparent member. The optical member 6 is disposed on the surface, and the optical member 6 is attached and fixed to the surface of the first translucent member 5 by heating and curing the uncured transparent member. Further, above the optical member 6, excitation is performed by light of the light emitting element 3 on the inner side of the opening or the upper surface of the reflecting member 2 so as to close the opening of the reflecting member 2 through the second light transmissive member 7. The wavelength conversion member 4 containing a fluorescent substance that emits fluorescence is disposed. In the optical member 6 of the present invention, a plurality of convex portions or concave portions are periodically arranged on at least one of the upper main surface and the lower main surface. In this way, the optical member 6 is attached to the surface of the first light transmissive member 5 and the second light transmissive member is disposed above the optical member 6. The wavelength conversion member 4 is arranged so as to close the opening of the reflection member 2 via 7. Thereby, the light incident on the optical member 6 from the light emitting element 3 via the first light-transmissive member 5 and the light reflecting surface 2a is the upper main surface and / or the lower main surface (upper main surface) of the optical member 6. Diffracted light diffracted on at least one of the surface and the lower main surface is propagated to the second translucent member 7 and incident on the wavelength conversion member 4.

  That is, the optical member 6 can reduce the incident angle of the light that is transmitted through the second light-transmissive member 7 and is incident on the wavelength conversion member 4, and the light transmitted through the optical member 6 is converted into the wavelength conversion member. 4 can be made incident at a small incident angle. As a result, the diffracted light diffracted by the optical member 6 is incident on the wavelength conversion member 4 without being totally reflected by the lower surface of the wavelength conversion member 4, so that the phosphor contained in the wavelength conversion member 4 is lowered. The light can be efficiently excited from the upper side to the upper side, the fluorescence generated from the phosphor of the entire wavelength conversion member 4 is increased, and the light output of the light emitting device is improved.

  The surface on which the plurality of convex portions or concave portions are formed may be only the upper main surface of the optical member 6, only the lower main surface, or both the upper main surface and the lower main surface. When formed on both main surfaces of the upper main surface and the lower main surface, the light is diffracted by both main surfaces, and the wavelength conversion member 4 is incident at a small incident angle that is closer to the lower surface of the wavelength conversion member 4. It is more preferable because it can be made incident on the light.

  Further, among the light emitted from the wavelength conversion member 4, the light reflected from the upper surface of the wavelength conversion member 4 and emitted toward the inside of the light emitting device has a refractive index smaller than the refractive index of the wavelength conversion member 4. Is totally reflected according to Snell's law at the interface with the translucent member. The totally reflected light is reflected upward again and is emitted from the upper surface of the wavelength conversion member 4, so that the light output of the light emitting device can be extremely effectively increased and the light emission efficiency can be improved.

  That is, a diffraction grating in which convex portions or concave portions are periodically arranged is formed on the upper main surface and / or the lower main surface of the optical member 6, so that the first light emitting element 3 and the light reflecting surface 2a are connected to the first main surface. Even if light is incident on the lower surface of the optical member 6 through the translucent member 5 at a large incident angle, the diffraction angle of the higher-order diffracted light incident on the second translucent member 7 (diffracted light and second The angle formed by the interface normal to the translucent member 7 is small. At this time, the light diffracted by the optical member 6 is propagated to the second translucent member 7 as n-th order diffracted light, but the first-order diffraction has the highest light intensity among the high-order diffracted light. The traveling direction of light also changes so that the diffraction angle formed with respect to the interface between the optical member 6 and the second light transmissive member 7 becomes small. The first-order diffracted light is refracted at the interface with the wavelength conversion member 4 having a refractive index larger than that of the second light-transmissive member 7, and the refraction angle becomes smaller according to Snell's law. As a result, a large amount of light is incident on the wavelength conversion member 4 and the incident light efficiently excites the phosphor contained in the wavelength conversion member 4 from the lower side to the upper side. The light output can be increased and the luminous efficiency can be improved.

  In addition, when the plurality of convex portions or concave portions formed on the upper main surface and / or the lower main surface of the optical member 6 are, for example, cylindrical convex portions or concave portions, the diameter is φ, and the height of the convex portion Alternatively, when the depth of the recess is T and the center wavelength of light emitted from the light emitting element 3 is λ, λ / 10 ≦ φ ≦ 10λ, λ / 3 ≦ T ≦ 3λ, and a plurality of protrusions or recesses When the interval of S is S, it is preferable that they are arranged at intervals of λ / 10 ≦ S ≦ 10λ. As a result, the light is diffracted by the optical member 6, and the diffracted diffracted light is incident on the lower surface of the wavelength conversion member 4 at a small incident angle, and the phosphor contained in the wavelength conversion member 4 is introduced from below. Since excitation is performed efficiently over the upper side, the amount of fluorescence generated from the phosphor of the wavelength conversion member 4 is increased, and the light output of the light emitting device is improved.

  In the case where the numerical range of the diameter φ, the height or depth T, and the interval S between the plurality of protrusions or recesses of the plurality of protrusions or recesses is exceeded, in any case, the first from the light emitting element 3 or the light reflecting surface 2a. With respect to the light incident on the optical member 6 through the translucent member 5, a phase shift of light from the light emitting element 3 using the wave nature of light cannot be generated by the convex portion or the concave portion, and the optical The member 6 cannot be transmitted as diffracted light to the second light transmissive member.

  The plurality of convex portions or concave portions formed on the upper main surface and / or the lower main surface of the optical member 6 have been described by taking a cylindrical shape as an example, but the shape thereof is a protruding portion such as an elliptical column shape or a quadrangular column shape. Alternatively, it may be a notch, and in this case, the diameter φ is the length of the longest part in plan view of the protrusion or notch (for example, the length of the long side in the case of a quadrangular prism).

  The optical member 6 is a transparent member in which a refractive index is equal to or larger than that of the first light-transmissive member 5 and a diffraction grating in which convex portions or concave portions are periodically arranged on the upper main surface is formed. In addition, it is preferable that the first translucent member 5 is disposed in contact with the surface. As a result, light that propagates from the light emitting element 3 through the first light transmissive member 5 and directly enters the optical member 6, or is reflected from the light emitting element 3 by the light reflecting surface 2 a, and the first light transmissive member 5 The light incident on the optical member 6 through the optical member 6 is easily incident on the optical member 6 without being totally reflected. Further, a part of the light reflected and propagated downward at the interface between the optical member 6 and the second light transmissive member 7 has a refractive index smaller than that of the optical member 6 and the first light transmissive member 5. Is totally reflected again at the interface, reflected upward (inside the optical member 6), and diffracted by a plurality of convex portions or concave portions formed on the upper surface of the optical member 6. The light can enter the member 7.

  In this way, the light from the light emitting element 3 can be hardly confined in the first light transmissive member 5, and the light that is reflected on the upper surface of the optical member 6 and returns to the first light transmissive member 5. Can be reduced. Therefore, since the light from the light emitting element 3 can be efficiently incident on the wavelength conversion member 4 without being confined in the light emitting device, the number of phosphors excited in the wavelength conversion member 4 increases, and the fluorescence is increased. As it increases, the light output of the light emitting device improves.

  When the optical member 6 is not disposed and the refractive index of the first light transmissive member 5 is larger than the refractive index of the second light transmissive member 7, the first light transmissive element 7 and the light reflecting surface 2a are used to transmit the first light transmissive member 5. A part of the light incident on the second light transmissive member 7 through the light transmissive member 5 is entirely in accordance with Snell's law at the interface between the first light transmissive member 5 and the second light transmissive member 7. By being reflected, the light is confined in the first light transmissive member 5 and diffusely reflected on the surface of the reflective member 2 or the base 1 to propagate through the first light transmissive member 5, resulting in a large light propagation loss. Become. As a result, the light from the light emitting element 3 is not efficiently incident on the wavelength conversion member 4 via the second light transmissive member 7, and the light emission necessary for exciting the phosphor contained in the wavelength conversion member 4. As the amount of light from the element 3 decreases, the amount of fluorescence generated from the phosphor decreases, and the light output of the light emitting device decreases.

  The optical member 6 is made of a transparent resin such as a silicone resin, an epoxy resin, or a urea resin having a high transmittance with respect to light in the ultraviolet light region to the visible light region, or a transparent material such as quartz glass, low melting glass, sol-gel glass, or the like. It consists of members. The optical member 6 can be manufactured by a molding method in which a previously formed diffraction grating mold is placed on the upper surface and / or the lower surface, and the mold is removed after thermosetting in an oven.

  In addition, the optical member 6 may be the same material as the first light-transmissive member 5 or have an equivalent refractive index. The optical member 6 may be the light directly incident on the optical member 6 from the light-emitting element 3 or the light-emitting element 3. The light that is incident on the optical member 6 after being reflected by the light reflecting surface 2a is refracted at the optical member 6 without being refracted at the interface between the first light transmissive member 5 and the optical member 6, and the second light transmissive. The light enters the sex member 7. As a result, the light-emitting device can efficiently excite the phosphor contained in the wavelength conversion member 4 from the lower side to the upper side, and can extremely effectively increase the light output of the light-emitting device and improve the light emission efficiency. .

  The second translucent member 7 has a refractive index smaller than that of the optical member 6 and the wavelength conversion member 4 and has a high transmittance with respect to light from the ultraviolet light region to the visible light region, such as silicone resin, epoxy resin, urea resin, and the like. It consists of transparent resin, transparent glass such as low melting point glass and sol-gel glass, and voids (gas layer).

  The second light transmissive member 7 may be appropriately selected in consideration of the material of the optical member 6 and the wavelength conversion member 4, the thermal expansion coefficient, and the like, and is not particularly limited. Thereby, while being able to make small the refraction angle of the light which injects into the wavelength conversion member 4 from the 2nd translucent member 7, the total reflection in this interface can be suppressed. Furthermore, the fluorescence emitted from the phosphor in the wavelength conversion member 4 and the light from the light emitting element 3 reflected by the phosphor without exciting the phosphor partially have a refractive index different from that of the wavelength conversion member 4. Then, the light is totally reflected at the interface with the small second translucent member 7 and is reflected upward again. Thereby, the fluorescence excited in the wavelength conversion member 4 is efficiently radiated to the outside of the light emitting device, and the light from the light emitting element 3 reflected by the phosphor without exciting the phosphor again has a wavelength. Since the phosphor in the conversion member 4 can be excited, the amount of fluorescence emitted from the phosphor increases. Therefore, the light from the light emitting element 3 is efficiently converted into fluorescence, and the converted fluorescence is efficiently radiated to the outside of the light emitting device without being confined inside the light emitting device, and the light output of the light emitting device is improved. .

  The second translucent member 7 may be formed by a method such as a method in which the optical member 6 is coated on the inside of the reflecting member 2 with an injector such as a dispenser and then thermally cured, or a space above the optical member 6. It is formed by disposing a portion (gas layer) and attaching the wavelength conversion member 4 so as to close the opening of the reflection member 2.

  The wavelength converting member 4 is made of a phosphor (epoxy substance or fluorescent pigment) capable of converting the wavelength of light emitted from the light emitting element 3 with a silicone resin or epoxy having a high transmittance with respect to light in the ultraviolet light region to the visible light region. It is formed by being dispersed in a transparent member made of transparent resin such as resin or urea resin, or transparent glass such as low melting point glass or sol-gel glass. The wavelength conversion member 4 is manufactured by, for example, pouring an uncured silicone resin in which a phosphor is dispersed into a mold having a predetermined shape prepared in advance and heating to form a plate by curing the silicone resin. Or by forming an uncured silicone resin containing phosphor on a smooth substrate by pouring it to a uniform thickness, and heating it to cure the silicone resin and cutting it into a plate shape. Or just do it.

  In addition, the light emitting device of the present invention is provided with one light source, or a plurality of light emitting devices, for example, a lattice shape, a staggered shape, a radial shape, or a circular or polygonal light emitting device group composed of a plurality of light emitting devices. By providing as a light source arranged so as to have a predetermined arrangement such as a plurality of groups formed in a shape, a lighting device can be obtained. As a result, the lighting device of the present invention can have lower power consumption and longer life than a lighting device using a conventional discharge when light emission by electron recombination of the light emitting element 3 made of a semiconductor is used. In addition, a small lighting device with less heat generation can be obtained. As a result, fluctuations in the excitation band gap in the light emitting element 3 due to heat can be suppressed, so that fluctuations in the center wavelength of light generated from the light emitting element 3 can be suppressed, and the phosphor excited by this light As the light emission color is uniform and uneven color is suppressed, it is possible to irradiate light with stable radiant light intensity and radiant light angle (light distribution distribution) over a long period of time, as well as uneven color and illuminance distribution on the irradiated surface It can be set as the illuminating device with little bias.

  In addition, the light emitting device of the present invention is provided as a light source, and by installing a reflector, an optical lens, a light diffusing plate, etc. optically designed in an arbitrary shape around these light emitting devices, light having a required light distribution is provided. It can be set as the illuminating device which can radiate.

  For example, a plurality of light emitting devices 101 of the present invention are arranged in a plurality of rows on the light emitting device driving circuit board 102 as shown in the plan view and the sectional view shown in FIGS. In the case of an illuminating device in which the optically designed reflector 9 is installed, a so-called staggered arrangement in which adjacent rows of light emitting devices 101 are arranged between a plurality of light emitting devices 101 arranged in a row. It is preferable. That is, when the light emitting devices 101 are arranged in a grid, the glare is strengthened by arranging the light emitting devices 101 as light sources on a straight line, and such a lighting device enters human vision. However, the staggered pattern makes the light source position evenly distributed and prevents the light from concentrating on a specific position. Etc. can be reduced.

  Furthermore, compared to the case where the light emitting devices 101 are not arranged in a staggered manner, the distance between the adjacent light emitting devices 101 is increased, so that thermal interference between the adjacent light emitting devices 101 is effectively suppressed, and the light emitting device in which the light emitting devices 101 are mounted. Heat accumulation in the device drive circuit board 102 is suppressed, and heat is efficiently dissipated outside the light emitting device 101. As a result, it is possible to manufacture a long-life lighting device that has less discomfort to human eyes and has stable optical characteristics over a long period of time.

  Further, the lighting device is a concentric arrangement of a circular or polygonal light emitting device 101 group composed of a plurality of light emitting devices 101 on the light emitting device drive circuit board 102 as shown in the plan view and the cross-sectional view shown in FIGS. In the case of a plurality of illuminating devices arranged in a group, it is preferable that the number of light emitting devices 101 arranged in one circular or polygonal light emitting device 101 group be increased from the central side of the illuminating device toward the outer peripheral side. Thereby, it is possible to arrange more light emitting devices 101 while maintaining an appropriate interval between the light emitting devices 101, and it is possible to further improve the illuminance of the lighting device.

  In addition, the density of the light emitting device 101 in the central portion of the lighting device can be reduced to suppress heat accumulation in the central portion of the light emitting device driving circuit board 102. Therefore, the temperature distribution in the light emitting device driving circuit board 102 becomes uniform, heat is efficiently transmitted to the external electric circuit board and the heat sink on which the lighting device is installed, and the temperature rise of the light emitting device 101 can be suppressed. As a result, the light-emitting device 101 can operate stably over a long period of time, and a long-life lighting device can be manufactured.

  Examples of such lighting devices include general lighting fixtures, chandelier lighting fixtures, residential lighting fixtures, office lighting fixtures, store lighting, display lighting fixtures, and street lamp lighting fixtures that are used indoors and outdoors. , Guide light fixtures and signaling devices, stage and studio lighting fixtures, advertising lights, lighting poles, underwater lighting lights, strobe lights, spotlights, security lights embedded in power poles, emergency lighting fixtures, flashlights , Electronic bulletin boards and the like, backlights such as dimmers, automatic flashers, displays, moving image devices, ornaments, illuminated switches, optical sensors, medical lights, in-vehicle lights, and the like.

  In addition, this invention is not limited to the example of said embodiment, It does not have any trouble in making a various change within the range which does not deviate from the summary of this invention. For example, the light-emitting device of the present invention can have an appropriate shape such as a circle, an ellipse, or a polygon in plan view.

It is sectional drawing which shows an example of embodiment of the light-emitting device of this invention. It is sectional drawing which shows the other example of embodiment of the light-emitting device of this invention. It is a top view which shows an example of embodiment of the illuminating device of this invention. It is sectional drawing of the illuminating device of FIG. It is a top view which shows the other example of embodiment of the illuminating device of this invention. It is sectional drawing of the illuminating device of FIG. It is sectional drawing of the conventional light-emitting device.

Explanation of symbols

1: Base 1a: Placement part 2: Reflecting member 2a: Light reflecting surface 3: Light emitting element
4: Wavelength conversion member 5: First translucent member 6: Optical member
7: Second translucent member

Claims (3)

A base on which a light emitting element is mounted on the upper surface;
A frame-shaped reflecting member attached to the upper surface of the substrate so as to surround the light emitting element, and having an inner peripheral surface as a light reflecting surface;
A first translucent member provided to cover the light emitting element inside the reflective member;
The refractive index is equal to or higher than the refractive index of the first translucent member, and a diffraction grating including a plurality of convex portions or concave portions is formed on at least one of the upper main surface and the lower main surface. An optical member attached to cover the translucent member,
A second translucent member having a refractive index smaller than that of the optical member and attached to cover the optical member;
A wavelength containing a phosphor that has a refractive index larger than that of the second light-transmissive member, is disposed so as to cover the second light-transmissive member, and is excited by light emitted from the light-emitting element to generate fluorescence. A light-emitting device comprising: a conversion member. When the outer diameter of the plurality of convex portions or concave portions is φ, the height or depth is T, the interval between the convex portions or the concave portions is S, and the center wavelength of light emitted from the light emitting element is λ, 2. The light emitting device according to claim 1, wherein λ / 10 ≦ φ ≦ 10λ, λ / 3 ≦ T ≦ 3λ, and λ / 10 ≦ S ≦ 10λ are satisfied. An illumination device comprising the light-emitting device according to claim 1 as a light source.

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