JP2010016108A - Light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-emitting device capable of reducing color phase irregularity and glare of emission light. <P>SOLUTION: The light-emitting device includes a substrate 12, an LED chip 11 mounted on the substrate 12, a reflecting member 14, and a color conversion member 13. The reflecting member 14 is arranged above the LED chip 11. The color conversion member 13 is arranged at such position as the direct light from the LED chip 11 and the reflected light from the reflecting member 14 enter, for conversion to the light in such color as different from the emission light of the LED chip 11. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a light emitting device such as an LED device using an LED chip.

  As shown in FIG. 6, a general LED device includes an LED chip 1, a substrate 2 on which the LED chip 1 is mounted, and a light reflecting member formed on the substrate 2 so as to surround the periphery of the LED chip 1. The reflector 3 is provided.

  In the LED device having such a configuration, when the light emission color of the LED chip 1 is converted to a desired color, a fluorescent member is filled in the sealing material 4 that is filled inside the reflector 3 and seals the LED chip 1. The method of containing is taken.

  In this case, when the light emitted from the LED chip 1 has a bowl-shaped light distribution as shown in FIG. 7, the intensity of the excitation light absorbed by the fluorescent member becomes uniform, and an LED device with high color rendering properties is obtained. can get.

  A light distribution as shown in FIG. 7 is often seen in a general LED chip in which a light emitting layer is formed on a transparent sapphire substrate.

  However, in recent years, a texture pattern or the like is sometimes applied to the upper surface of the LED chip in order to improve the light extraction efficiency from the LED chip. Many of the LED chips in this case have a light distribution in which light is emitted most directly above as shown in FIG.

  In order to manufacture a white light emitting LED device in the structure of FIG. 6, for example, a blue light emitting LED chip 1 is used, and a sealing material 4 containing a fluorescent member that uses blue light as excitation light is used. In this example, if the LED chip 1 has the light distribution shown in FIG. 8, the excitation light is strong in the direction P directly above the LED chip 1 and the blue color is strong. In the diagonal direction Q, the emission color (yellow) by the fluorescent member is It comes out strongly. In other words, a constant color rendering cannot be obtained.

  Moreover, since the high power LED device used for the illumination application is a point light source, when the LED chip showing the light distribution in FIG. 8 is used, the brightness directly above the LED chip is high, and it was felt very dazzling when viewed directly.

  Therefore, it has been necessary to reduce glare by applying a method of attaching a diffusion plate above the upper surface of the LED chip (FIG. 9) or a method of attaching a lens (FIG. 10) so that the light distribution spreads.

  However, in that case, not all of the light emitted from the LED chip could be used as the emitted light of the LED device, and as a result, even if an LED chip with high luminous efficiency was used, the efficiency was reduced.

In addition, although the technique which reflects the light which goes right above a LED chip to a side is disclosed by patent document 1, the above unevenness | luminance of a luminescent color and the glare are not eliminated.
JP-A-2005-221706

  The objective of this invention is providing the light-emitting device which can eliminate the subject which the said background art has. An example of the purpose is to reduce unevenness in color and glare even when using an LED chip that emits light most directly upward.

  In order to solve the above problems, a light-emitting device of one embodiment of the present invention includes a substrate, a light-emitting element mounted on the substrate, a reflective member, and a color conversion member. The reflecting member is disposed above the light emitting element. The color conversion member is disposed at a position where the direct light from the light emitting element and the reflected light from the reflection member are incident, and converts the light into a light having a different color from the light emitted from the light emitting element.

  According to the present invention, it is possible to reduce color unevenness and glare of light emitted from a light emitting device.

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

  1A is a top view of the light emitting device according to the first embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along line X-X ′ in FIG.

  As shown in this figure, the LED device 10 of this embodiment includes an LED chip 11, a substrate 12 on which the LED chip 11 is mounted, and a frame formed so as to surround the side portion of the LED chip 11 on the substrate 12. A color conversion member 13 and a reflection member 14 disposed above the LED chip 11.

  The substrate 12 includes a base plate 15 and insulating layers 16 and 17 stacked on the base plate 15.

  As the material of the base plate 15, metal, ceramic, plastic that is not easily thermally deformed, or the like is employed. In particular, when the light emitting device is designed as a high power LED device, a material having a relatively high thermal conductivity such as Al, Cu, or alumina is preferable in order to dissipate the self-heating generated during lighting. On the other hand, a glass epoxy substrate is employed as the material of the insulating layer 16. Further, as the material of the insulating layer 17, AlN having a relatively high thermal conductivity and insulating properties is employed.

  The insulating layer 16 is bonded to the base plate 15, has a shape that matches the outer shape of the base plate 15, and has a rectangular window hole 16 a at the center that is larger than the outer periphery of the LED chip 11. The insulating layer 17 is disposed on the inner surface of the window hole 17a in the base plate 15 with a gap from the insulating layer 16.

  A wiring pattern 19 that is electrically connected to the LED chip 11 is provided on the surface of the insulating layers 16 and 17 opposite to the base plate 15. The wiring pattern 19 on the insulating layer 16 is covered and protected with a resist except for its both ends.

  The LED chip 11 is mounted on the upper surface of the insulating layer 17. Then, the front surface electrode of the LED chip 11 and the wiring pattern 19 on the insulating layer 16, and the wiring pattern on the insulating layer 17 connected to the back electrode of the LED chip 11 and the wiring pattern 19 on the insulating layer 16 are They are electrically connected by a bonding wire 22 which is a conductive wire such as Au or Al.

  Further, the frame-shaped color conversion member 13 is formed on the substrate 12 so as to surround the side portion of the LED chip 11 outside the connection portion between the wiring pattern 19 and the bonding wire 22. In the present embodiment, the color conversion member 13 is a hollow column (cylindrical) formed around the light emission center of the LED chip 11.

  The color conversion member 13 is a member that converts light emitted from the LED chip 11 into a wavelength (color) different from the light. For example, the color conversion member 13 is formed by dispersing a phosphor that absorbs light emitted from a blue LED and converts it into yellow light in a transparent resin, and molding the resin into a desired shape. In this example, part of the blue light emitted from the LED chip 11 is converted into yellow light by the phosphor in the color conversion member 13, and the yellow light and the blue light that passes through the color conversion member 13 without being converted. Are mixed with each other, the emitted light becomes white light.

  Further, the reflecting member 14 is disposed above the LED chip 11 and is in contact with the edge of the opening so as to close the opening of the color conversion member 13. A space inside the color conversion member 13 closed by the reflection member 14 is filled with a transparent sealing material 23 excellent in light transmittance. As a result, the LED chip 11 and the bonding wire 22 are sealed in the sealing material 23.

  As the sealing material 23, an epoxy resin, a silicone resin, or the like is used. Moreover, as a material of the reflecting member 14, a white resin material, a metal material having a reflecting surface coated with a white paint, or the like is used.

  The side of the reflecting member 14 facing the LED chip 11 is formed in an inverted cone shape, and the opposite side is formed in a planar shape. The vertex of the inverted conical shape of the reflecting member coincides with the center of the color conversion member 13 and the light emission center of the LED chip 11. The color conversion member 13 is provided at a position where direct light from the LED chip 11 and reflected light from the reflection member 14 enter.

  By such a reflecting member 14, it is possible to disperse the strongest light in the upward direction among the light emitted from the LED chip 11 to the side color conversion member 13. As a result, the LED device 10 having a wide light distribution characteristic as shown in FIG. 2 can be obtained without using a lens or a dispersion plate. In addition, the arrow in FIG. 2 and its length represent the direction of emitted light and its intensity.

  In the LED device 10 having the above-described configuration, the light emitted directly from the LED chip 11 is incident on the color conversion member 13 on the side, so that the colored light emitted from the LED chip 11 has a different wavelength (color) from that light. The light having the wavelength is converted and emitted from the color conversion member 13 as diffused light. For this reason, the uneven color of the emitted light on the light emitting side of the LED device is reduced. In addition, the brightness directly above the LED chip is reduced, eliminating glare.

  Further, even if the light from the LED chip 11 is reflected by the reflecting member 14, it is emitted after passing through the color conversion member 13, so that a great reduction in the total luminous flux emitted from the LED device 10 can be avoided.

(Other embodiments)
The present invention is not limited to the shape shown in FIG. That is, it is preferable to change the shapes of the color conversion member 13 and the reflection member 14 in accordance with the light distribution characteristics of the LED chip 11 so that the color rendering property of the light emitted from the LED device 10 is improved. Hereinafter, the example of a change is shown in FIGS.

  FIG. 3 is a longitudinal sectional view of a light emitting device according to the second embodiment of the present invention. In the form shown in this figure, the height of the cylindrical color conversion member 13 (thickness in a direction perpendicular to one surface of the substrate 12) is made larger than that of the first embodiment, and accordingly, the reflection member The height of the inverted cone shape of 14 is also increased.

  FIG. 4 is a longitudinal sectional view of a light emitting device according to the third embodiment of the present invention. In the form shown in this figure, the shape of the cylindrical color conversion member 13 as in the first embodiment is changed to a tapered cylindrical shape. Specifically, the side surface of the color conversion member 13 is inclined so that the outer diameter of the cylindrical color conversion member 13 decreases with the direction away from the substrate 12.

  FIG. 5 is a top view of a light emitting device according to a fourth embodiment of the present invention. In the form shown in this figure, the shape of the cylindrical color conversion member 13 as in the first embodiment is changed to a rectangular tube shape, and the shape of the reflective member 14 on the side facing the LED chip 11 is accordingly changed. This is a pyramid shape. For example, as shown in FIG. 5, the color conversion member 13 is formed in a cylindrical shape having a square shape when viewed from the upper surface. The reflecting member 14 is formed in a quadrangular pyramid shape, and each of the four side surfaces of the quadrangular pyramid faces each side surface of the color conversion member 13. Of course, the present invention may be applied to other forms.

  Note that a light-emitting device created by appropriately combining the shapes in the embodiments described above is also included in the present invention. In addition, a light emitting module using a plurality of such light emitting devices, and a light emitting device or a lighting device including the light emitting module are also included in the present invention.

(A) is a top view of the light emitting device according to the first embodiment of the present invention, and (B) is a longitudinal sectional view taken along line X-X ′ of (A). The figure which shows the light distribution characteristic in the light-emitting device of 1st embodiment. The longitudinal cross-sectional view of the light-emitting device by 2nd embodiment of this invention. The longitudinal cross-sectional view of the light-emitting device by 3rd embodiment of this invention. The top view of the light-emitting device by 4th embodiment of this invention. A longitudinal sectional view of a general LED device. The side view which shows an example of the light distribution characteristic of a LED chip. The side view which shows the other example of the light distribution characteristic of a LED chip. The figure which shows the conventional method with respect to the subject which this invention tends to solve. The figure which shows the conventional method with respect to the subject which this invention tends to solve.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 LED device 11 LED chip 12 Board | substrate 13 Color conversion member 14 Reflective member 15 Base plates 16 and 17 Insulating layer 16a Window hole 19 Wiring pattern 22 Bonding wire 23 Sealing material

Claims (6)

In a light emitting device including a substrate and a light emitting element mounted on the substrate,
A reflective member disposed above the light emitting element;
A color conversion member that is disposed at a position where the direct light from the light emitting element and the reflected light from the reflecting member are incident, and converts the light into a color different from the light emitted from the light emitting element;
A light emitting device further comprising:   The light emitting device according to claim 1, wherein the color conversion member is formed on the substrate so as to surround a side portion of the light emitting element. The color conversion member is formed in a cylindrical shape,
The light emitting device according to claim 1, wherein the reflecting member is disposed so as to close an opening of the cylindrical color conversion member.   The light emitting device according to claim 3, further comprising a transparent sealing material filled in a space inside the color conversion member closed by the reflection member.   5. The light emitting device according to claim 1, wherein a side of the reflecting member facing the light emitting element is formed in a cone shape.   6. The light emitting device according to claim 5, wherein a vertex of the cone is coincident with a center of the color conversion member and a light emission center of the light emitting element.

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