JP2010034183A - Light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-emitting device that can be used more efficiently and generates white light suitable for a display device for displaying a color image. <P>SOLUTION: On a substrate 4 in the light-emitting device 2, blue and green light-emitting elements 6, 8 are mounted, and sealed by a red sealing resin 12 collectively. In the red sealing resin 12, a red phosphor 10 is mixed into a transparent resin. In the light-emitting device 2, the blue and green light-emitting elements 6, 8 emit light each, and the red phosphor 10 is excited by light from the blue light-emitting element 6 to emit light, thus generating white light. Also, the red sealing resin 12 is covered with a light-scattering resin 18 into which a scattering material 16 is mixed, thus improving color mixture properties. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a light emitting device using a light emitting element, and more particularly to a device suitable for a display device that displays a color image.

  In recent years, blue light emitting diodes with high luminous efficiency (hereinafter referred to as “light emitting diodes” are abbreviated as “LEDs”) have been developed, and this blue LED is combined with a red LED and a green LED to realize a full color display. An apparatus has been developed (see, for example, Patent Document 1). Such a display device is provided with a color filter that allows red, green, and blue light to pass therethrough, and the color filter is configured to irradiate light from each of the red, green, and blue LEDs and the white LED. .

As a white LED used in such a display device, a blue LED and a yellow phosphor housed in one package has been used. However, when white light emitted from the white LED passes through the color filter described above, the color of a wavelength portion having no peak (for example, green) may become unclear. Therefore, there is a demand for an LED that generates white light including peaks of wavelengths (blue, red, and green) that match the transmission wavelength range of the color filter. The blue LED, the red phosphor, and the green phosphor are housed in one package. A white LED (see, for example, Patent Document 2) has been considered suitable.
JP 2004-4626 A JP 2005-31136 A

  However, since the white LED uses not only the light emitted from the blue LED but also the green light from the green phosphor to excite the red phosphor, there is a problem that the luminous efficiency of the entire package is lost. It was.

  In addition, the half-value width of the emission spectrum of the light emitted by the green phosphor is wider than the transmission wavelength range of the color filter, so it overlaps with the transmission part of the other color of the color filter, and the transmission efficiency of the color filter decreases. It was supposed to lose efficiency.

  The problem to be solved by the present invention is to solve the above-mentioned problems of the prior art and provide a light emitting device that can be used more efficiently and generates white light suitable for a display device that displays a color image. There is.

  The light emitting device of the present invention includes a substrate, a blue light emitting element mounted on the substrate, a green light emitting element mounted on the substrate side by side with the blue light emitting element, a red phosphor, and the blue light emitting device. A red sealing resin that collectively seals the light emitting element and the green light emitting element. The light emitting device includes a scattering resin mixed with a scattering material and covering the red sealing resin.

  The light emitting device of the present invention includes a substrate, a blue light emitting element mounted on the substrate, a green light emitting element mounted on the substrate side by side with the blue light emitting element, and a red phosphor. A red sealing resin that seals only the blue light emitting element; and a sealing resin that collectively seals the green light emitting element and the red sealing resin. The sealing resin in the light emitting device is made of a scattering resin mixed with a scattering material.

  The light emitting device of the present invention includes a substrate, a blue light emitting element mounted on the substrate, a green light emitting element mounted on the substrate side by side with the blue light emitting element, and a red phosphor. A red sealing resin for sealing only the blue light emitting element; and a sealing resin for sealing only the green light emitting element. The sealing resin in the light emitting device is made of a scattering resin mixed with a scattering material.

  The light emitting device of the present invention uses a blue light emitting element, a green light emitting element, and a red phosphor excited by light from the blue light emitting element, with an emphasis on a wide color gamut for use in a display device. ing. The red phosphor is mixed with a sealing resin that seals only the blue light emitting element or the blue light emitting element and the green light emitting element at once. Thereby, white light having a peak of blue light, green light, and red light can be generated. In particular, by adjusting the light emission of the blue light emitting element and the green light emitting element respectively, it becomes possible to set the half-value width of the emission spectrum of blue, green, and red to a width suitable for the color filter, and each color light passes through the color filter. Passing evenly and crossing over with other colors will not lose efficiency.

  Further, according to the present invention, since the green light emitting element is used, the green light is not consumed for exciting the red phosphor, and the luminous efficiency of the entire package is not lost.

  Also, by sealing only the blue light emitting element with the red sealing resin mixed with the red phosphor, the red phosphor is collected around the blue light emitting element that emits the excitation light of the red phosphor, and the green light emitting element is collected. Can be efficiently irradiated.

  Further, since the scattering material is mixed in the sealing resin for sealing the red sealing resin or the green light emitting element, the color mixing property of the light emission of the blue light emitting element, the green light emitting element and the red phosphor can be improved.

  In the light emitting device of the present invention, a blue light emitting element and a green light emitting element are mounted on a substrate and sealed with a resin. Sealing with this resin is performed by sealing the blue light emitting element and the green light emitting element together with a red sealing resin mixed with a red phosphor, or sealing only the blue light emitting element with a red sealing resin. The green light emitting element and the red sealing resin are collectively sealed with the sealing resin, or only the blue light emitting element is sealed with the red sealing resin, and only the green light emitting element is sealed with the sealing resin. It has become. In this light emitting device, each of the blue light emitting element and the green light emitting element emits light, and excited by the light from the blue light emitting element, the red phosphor emits light, thereby generating white light. In addition, the color mixing property is enhanced by mixing the scattering material into the sealing resin.

  FIG. 1 is a sectional view showing a light emitting device according to Example 1 of the present invention. The light emitting device 2 in this embodiment includes a substrate 4 having a conductive pattern (not shown) formed on the surface thereof, a blue light emitting element 6 mounted on the surface of the substrate 4 with a conductive paste, a wire, and the like, and a green color. A light-emitting element 8, a red sealing resin 12 in which the red phosphor 10 is mixed and the blue light-emitting element 6 and the green light-emitting element 8 are collectively sealed, and a frame body 14 that surrounds the side surface of the red sealing resin 12. It is equipped with.

  The blue light emitting element 6 is made of, for example, a blue LED using an InGaN compound semiconductor having an emission wavelength band of 470 to 490 nm. The green light-emitting element 8 is made of, for example, a green LED using an InGaN-based or GaP-based compound semiconductor having an emission wavelength band of 490 to 520 nm.

  The board | substrate 4 consists of insulating board | substrates, such as a glass epoxy, BT resin, ceramics, a metal core which make a substantially rectangular parallelepiped, for example. As described above, a conductive pattern is provided on the surface of the substrate 4, and the blue light emitting element 6 and the green light emitting element 8 are mounted thereon by die bonding, wire bonding, or the like.

The red phosphor 10 is made of a particulate fluorescent material that is excited by blue light from the blue light emitting element 6 and emits red fluorescence. As the red phosphor 10 in this embodiment, for example, Eu ²⁺ (europium) solid solution CaAlSiN ₃ (calcium, aluminum, silicon trinitride) phosphor or the like is used.

  The red sealing resin 12 is obtained by mixing the red phosphor 10 into a transparent resin such as an epoxy resin or a silicon resin. In this embodiment, the blue light emitting element 6 and the green light emitting element 8 are filled by filling the frame 14 attached to the surface of the substrate 4 so as to surround the blue light emitting element 6 and the green light emitting element 8 with the red sealing resin 12. Are collectively sealed.

  In addition, the inner surface of the frame body 14 facing the red sealing resin 12 is a reflecting surface such as a mirror surface. Thereby, the light from the blue light emitting element 6, the green light emitting element 8, and the red phosphor 10 is reflected to increase the light emission efficiency.

  In the light emitting device 2 of the present embodiment having the above-described configuration, blue light and green light are emitted upward in the drawing by causing the blue light emitting element 6 and the green light emitting element 8 to emit light. At this time, the red phosphor 10 is excited by light from the blue light emitting element 6 to emit red light. Thus, the light emitting device 2 emits white light having clear peaks of blue light, green light, and red light.

  Even if the red phosphor 10 is excited not only by the light from the blue light-emitting element 6 but also by the light from the green light-emitting element 8, the green light-emitting element 8 is a light-emitting body, so that the green light is red phosphor. 10 is not consumed. Therefore, unlike the conventional one using a plurality of phosphors, light is not consumed between the phosphors, and the light emission efficiency can be increased.

  FIG. 2 is a cross-sectional view showing a partial modification of the light emitting device 2 shown in FIG. In the light emitting device 2, a scattering resin 18 that covers the upper surface of the red sealing resin 12 is provided. The scattering resin 18 is obtained by mixing the scattering material 16 in a transparent resin such as an epoxy resin or a silicon resin. The scattering material 16 scatters light, and is made of particles that refract or reflect light such as glass or metal such as Au or Ag.

  When the scattering resin 18 as described above is provided, light from the blue light emitting element 6, the green light emitting element 8, and the red phosphor 10 is scattered and radiated by being refracted or reflected in the scattering resin 18. As a result, the lights mix and emit light so that the entire surface is uniformly white.

  The scattering resin 18 is formed so as to cover the upper surface of the red sealing resin 12 by filling the frame body 14.

  FIG. 3 is a cross-sectional view showing a light-emitting device according to Example 2 of the present invention. In addition, the same code | symbol is attached | subjected about the same part as Example 1 shown in FIG.1 and FIG.2, and detailed description is abbreviate | omitted. The light emitting device 22 in the present embodiment includes the substrate 4, the blue light emitting element 6 and the green light emitting element 8 mounted on the substrate 4, and the frame body 14 surrounding them, like the light emitting device 2 described above. ing.

  The light emitting device 22 includes a red sealing resin 24 that seals only the blue light emitting element 6 and a sealing resin 26 that seals the red sealing resin 24 and the green light emitting element 8 together. Yes. Similar to the red sealing resin 12 described above, the red sealing resin 24 is obtained by mixing the red phosphor 10 into a transparent resin. The sealing resin 26 is made of a transparent resin such as an epoxy resin or a silicon resin, and fills the frame 14 to seal the red sealing resin 24 and the green light emitting element 8 together. It is supposed to be.

  In the light emitting device 22 of the present embodiment having the above configuration, the red phosphors 10 are assembled around the blue light emitting element 6 by sealing only the blue light emitting element 6 with the red sealing resin 24. Thereby, the red phosphor 10 can obtain sufficient excitation light from the blue light emitting element 6. Further, the light from the green light emitting element 8 passes through the transparent sealing resin 26 without being obstructed by the red phosphor 10, and the luminous efficiency can be increased.

  FIG. 4 is a cross-sectional view showing a partial modification of the light emitting device 22 shown in FIG. In the light emitting device 22, the red sealing resin 24 and the green light emitting element 8 are collectively sealed with a scattering resin 28 in which the scattering material 16 is mixed into the sealing resin 26.

  In the light emitting device 22, light from the blue light emitting element 6, the green light emitting element 8, and the red phosphor 10 is scattered by being refracted and reflected by the scattering material 16. As a result, the color mixing property increases, and the entire upper surface of the light emitting device 22 emits white light evenly.

  FIG. 5 is a sectional view showing a light emitting device according to Example 3 of the invention. The same parts as those in the first and second embodiments are denoted by the same reference numerals, and detailed description thereof is omitted. The light emitting device 32 in this example is similar to the light emitting devices 2 and 22 described above, the substrate 4, the blue light emitting element 6 and the green light emitting element 8 mounted on the substrate 4, the frame body 14 surrounding them, It has.

  The light emitting device 32 includes a red sealing resin 34 that seals only the blue light emitting element 6 and a sealing resin 36 that seals only the green light emitting element 8. Similar to the red sealing resins 12 and 24 in the first and second embodiments, the red sealing resin 34 is obtained by mixing the red phosphor 10 into a transparent resin. The sealing resin 36 is made of a transparent resin, like the sealing resin 26 in the second embodiment. Both the red sealing resin 34 and the sealing resin 36 are filled in the frame body 14 to seal the blue light emitting element 6 and the green light emitting element 8 respectively. The red sealing resin 34 and the sealing resin 36 are in close contact with each other.

  In the light emitting device 32 configured as described above, only the blue light emitting element 6 is sealed with the red sealing resin 34 as in the second embodiment, and therefore the red phosphor 10 is assembled around the blue light emitting element 6. In addition, the light from the green light emitting element 8 is not obstructed by the red phosphor 10, and the luminous efficiency can be increased.

  FIG. 6 is a cross-sectional view showing a partial modification of the light emitting device 32 shown in FIG. In the light emitting device 32, only the green light emitting element 8 is sealed with a scattering resin 38 in which the scattering material 16 is mixed into the sealing resin 36.

  In the light emitting device 32, the scattering material 16 scatters the light from the green light emitting element 8 by being refracted and reflected, and the blue light emitting element 6 and the red fluorescent light reaching the scattering resin 38 through the red sealing resin 34. Light from the body 10 is also scattered. This enhances color mixing.

  The light emitting devices 2, 22, and 32 in each of the above embodiments efficiently emit white light having clear blue, green, and red peaks, and are suitable for display devices that display color images. Become.

  Further, since the blue light emitting element 6 is entirely covered and sealed with the red sealing resins 12, 24, and 34, the light emitted from the blue light emitting element 6 can be efficiently used for light emission of the red phosphor without leaving any excess. it can.

It is sectional drawing of the light-emitting device which concerns on Example 1 of this invention. It is sectional drawing which shows the example of a partial change of the light-emitting device shown in FIG. It is sectional drawing of the light-emitting device which concerns on Example 2 of this invention. It is sectional drawing which shows the example of a partial change of the light-emitting device shown in FIG. It is sectional drawing of the light-emitting device which concerns on Example 3 of this invention. It is sectional drawing which shows the example of a partial change of the light-emitting device shown in FIG.

Explanation of symbols

2, 22, 32 Light emitting device 4 Substrate 6 Blue light emitting element 8 Green light emitting element 10 Red phosphor 12, 24, 34 Red sealing resin 14 Frame 16 Scattering material 18, 28, 38 Scattering resin 26, 36 Sealing resin

Claims (6)

A substrate,
A blue light emitting device mounted on the substrate;
A green light emitting element mounted on the substrate side by side with the blue light emitting element;
A red sealing resin mixed with a red phosphor and sealing the blue light emitting element and the green light emitting element together;
A light emitting device comprising:   The light emitting device according to claim 1, further comprising a scattering resin mixed with a scattering material and covering the red sealing resin. A substrate,
A blue light emitting device mounted on the substrate;
A green light emitting element mounted on the substrate side by side with the blue light emitting element;
A red sealing resin in which red phosphor is mixed and only the blue light emitting element is sealed;
A sealing resin that collectively seals the green light emitting element and the red sealing resin;
A light emitting device comprising:   4. The light emitting device according to claim 3, wherein the sealing resin is made of a scattering resin mixed with a scattering material. A substrate,
A blue light emitting device mounted on the substrate;
A green light emitting element mounted on the substrate side by side with the blue light emitting element;
A red sealing resin in which red phosphor is mixed and only the blue light emitting element is sealed;
A sealing resin for sealing only the green light emitting element;
A light emitting device comprising:   6. The light emitting device according to claim 5, wherein the sealing resin is made of a scattering resin mixed with a scattering material.

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