JP4876760B2 - Light emitting device and white conversion sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting device that is hard to produce variance of color, and to provide a white color conversion sheet used therefor. <P>SOLUTION: The light emitting device is provided with a plurality of blue LED light sources with blue LED chips, and a white color conversion sheet that is provided to the blue LED light sources arranged at such a spacing to the blue LED chip that a blue light emitted from the blue LED chip may be converted into other colors; and is provided with a light transmission resin layer that contains a phosphor to convert the blue light into a light enough to substantially obtain a white light by mixing with the blue light. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a light emitting device that includes a blue light emitting diode (blue LED) and emits white light, and a white conversion sheet used therefor.

  Conventionally, a blue LED chip that emits blue light, and a color conversion unit that contains a phosphor that absorbs blue light emitted by the blue LED chip and emits green light, yellow light, red light, and the like, Blue LEDs that emit white light are known (see, for example, Patent Document 1 and Patent Document 2).

Generally, in a blue LED, the color conversion unit is provided in the LED mounting unit and is directly formed on the blue LED chip.
Since the LED mounting portion of the blue LED has a small size, it is difficult to control the amount of the phosphor when the color conversion portion is provided in the LED mounting portion. Therefore, color variations (color temperature variations) are likely to occur due to individual blue LEDs. For example, when it is desired to obtain a light emitting device that emits white light, if there is a variation in the amount of phosphor for each blue LED, the emission color obtained by each blue LED changes to a pale blue tone of high temperature or vice versa. Change to a yellowish hue at low temperature. This is because the color tone is determined by the ratio of the blue light from the blue LED chip and the light obtained by color-converting the blue light. Such variation in color tone is easily determined as uneven color, particularly when a plurality of blue LEDs are provided in a planar shape.
Also, color variations are likely to occur even when the emission wavelength is different for each blue LED.

  Generally, the color conversion part in a blue LED is obtained by dispersing a phosphor in a light-transmitting resin. As described above, since the color conversion part is directly formed on the blue LED chip, the light-transmitting resin contained in the color conversion part is exposed to high energy blue light or heat generated by the blue LED chip. And deteriorates. In addition, the phosphor included in the color conversion unit is also exposed to heat of high energy blue light or heat generated by the blue LED chip, resulting in deterioration or temperature quenching.

  In order to solve such a problem, a blue LED is not used, but an ultraviolet LED including an ultraviolet LED chip and a color conversion unit arranged at a distance from the ultraviolet LED chip is proposed. (For example, see Patent Document 3).

Japanese Patent No. 2927279 JP 2001-148512 A JP 2005-136006 A

However, in the case where a plurality of the ultraviolet light LEDs are provided, a color conversion portion is formed for each ultraviolet light LED, so that it is considered that color variation also occurs for each LED light source.
The present invention has been made in view of the above problems, and a main object of the present invention is to provide a light-emitting device in which color variations are unlikely to occur and a white conversion sheet used therefor.

  In order to achieve the above object, the present invention provides a plurality of blue LED light sources having a blue LED chip, the plurality of blue LED light sources, and the blue LED chip with respect to the blue LED chip. Light of a color that is arranged with a gap that can convert blue light emitted from the chip into light of another color and that can substantially obtain white light by mixing the blue light with the blue light. And a white conversion sheet having a light-transmitting resin layer containing a phosphor to be converted into a light-emitting device.

According to the present invention, the white conversion sheet is provided for a plurality of blue LED light sources, and the white conversion sheet and the blue LED light source are provided as separate members. In the layer, the phosphor can be uniformly dispersed in the layer. Thereby, it is possible to suppress color variation. Furthermore, according to the present invention, the blue LED chip of the blue LED light source and the white conversion sheet are arranged with a predetermined gap, so that the blue LED chip generates heat and the high energy of blue light from the blue LED chip. It is possible to suppress deterioration of the light-transmitting resin and the phosphor and temperature quenching of the phosphor. Thereby, uniform white light without color unevenness can be obtained.
Furthermore, since the light-transmitting resin layer constituting the white conversion sheet is obtained by dispersing phosphors in the light-transmitting resin and has excellent moldability, light emitting devices having various shapes can be obtained. Is possible.
In addition, as compared with the conventional case where a color conversion part containing a phosphor is provided for each blue LED light source, it is possible to increase the area of the white conversion sheet, so the control of the phosphor content, and It is easy to make the phosphor content uniform throughout the light-transmitting resin layer.

In the above invention, the phosphor may be a yellow phosphor that converts the blue light into yellow light. This is because a light-emitting device that emits white light can be obtained with such a configuration.
Further, the phosphor may be a yellow phosphor that converts the blue light into yellow light, and a red phosphor that converts the blue light into red light. Furthermore, the phosphor may be a green phosphor that converts the blue light into green light, and a red phosphor that converts the blue light into red light. This is because with such a configuration, a light emitting device that emits white light and has high color rendering properties can be obtained.

  Moreover, in this invention, the said white conversion sheet may further have the light introduction layer formed on the said transparent resin layer. This is because the light-introducing layer is formed on the white conversion sheet, whereby blue light from the blue LED light source can be efficiently incident on the light-transmitting resin layer and light extraction efficiency can be increased.

  The present invention is also used in the above-described light-emitting device, and converts the blue light emitted from the blue LED chip of the blue LED light source into light of a color that becomes substantially white light by mixing with the blue light. Provided is a white conversion sheet having a light-transmitting resin layer containing a body.

  Since the white conversion sheet of the present invention is used in the above-described light emitting device, when used in a predetermined light emitting device, as described above, color variation, deterioration of the light-transmitting resin and the phosphor, It is possible to suppress the temperature quenching of the phosphor. In addition, the light-transmitting resin layer has a phosphor dispersed in the light-transmitting resin and is excellent in moldability. Therefore, when a light-emitting device is manufactured using the white conversion sheet of the present invention. It is possible to obtain light emitting devices having various shapes. Furthermore, since the white conversion sheet of the present invention can have a large area, it is easy to control the phosphor content and to uniformly disperse the phosphor in the light-transmitting resin layer.

  According to the present invention, since the white conversion sheet is provided for a plurality of blue LED light sources and arranged with a predetermined gap with respect to the blue LED chip of the blue LED light source, color variation, There is an effect that the deterioration of the light-transmitting resin and the phosphor and the temperature quenching of the phosphor can be suppressed. In addition, since the white conversion sheet is excellent in moldability, there is an effect that the degree of freedom in designing the light emitting device is increased.

  Hereinafter, the light emitting device and the white color conversion sheet of the present invention will be described in detail.

A. First, the light emitting device of the present invention will be described.
The light emitting device of the present invention includes a plurality of blue LED light sources having a blue LED chip, and blue light emitted from the blue LED chip to the blue LED chip. It is arranged with a gap that can be converted into light of other colors, and contains a phosphor that converts the blue light into light of a color that can substantially obtain white light by mixing with the blue light. And a white conversion sheet having a light transmissive resin layer.

The light emitting device of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic plan view showing an example of the light-emitting device of the present invention, and FIG. 2 is a cross-sectional view taken along line AA of FIG. 1 and 2 includes a substrate 2, a plurality of blue LED light sources 3 arranged in an array on the substrate 2, and a blue LED chip of the plurality of blue LED light sources 3. On the other hand, it has the white conversion sheet 5 arrange | positioned at predetermined intervals. The white conversion sheet 5 contains a phosphor that converts blue light emitted from the blue LED chip of the blue LED light source 3 into light of a color that can substantially obtain white light by mixing with the blue light. It is comprised from the light transmissive resin layer 4 to do. In FIG. 1, a part of the white conversion sheet is omitted.

  In the above light-emitting device, for example, when the phosphor included in the light-transmitting resin layer of the white conversion sheet is a yellow phosphor that converts blue light into yellow light, blue light is emitted from the blue LED chip of the blue LED light source. When emitted, the blue light is absorbed by the yellow phosphor contained in the light-transmitting resin layer and emitted, and the blue light that is not absorbed by the yellow phosphor and passes through the white conversion sheet. White light can be obtained by mixing colors.

  According to the present invention, the white conversion sheet is provided not for each blue LED light source but for a plurality of blue LED light sources, and the white conversion sheet and the blue LED light source are separate members. Therefore, in the light transmissive resin layer constituting the white conversion sheet, the phosphor can be uniformly dispersed in the layer. Thereby, it is possible to suppress color variation due to a difference in phosphor content.

  Furthermore, according to this invention, not only the light in the direction perpendicular to the white conversion sheet but also the light in the oblique direction among the blue light emitted from the blue LED chip is incident on the white conversion sheet. The blue light emitted in the direction perpendicular to the white conversion sheet from the same blue LED chip and the blue light emitted in the oblique direction with respect to the white conversion sheet differ in the portion incident on the white conversion sheet. . Therefore, for example, even when the emission wavelength and the luminance are different for each blue LED chip, the color variation and luminance variation for each blue LED chip can be reduced.

  As described above, according to the present invention, it is possible to average the differences due to the individual blue LED light sources as in the prior art, and obtain uniform white light without color unevenness.

  In addition, according to the present invention, the blue LED chip of the blue LED light source and the white conversion sheet are arranged with a predetermined gap, so that the temperature effect due to heat generation of the blue LED chip and the blue color from the blue LED chip It is possible to suppress the deterioration of the light-transmitting resin and phosphor contained in the light-transmitting resin layer of the white conversion sheet and the temperature quenching of the phosphor due to the influence of high light energy. It is. In particular, since the distance between the blue LED chip and the white conversion sheet can be increased compared to the conventional case where a color conversion part containing a phosphor is provided in a part of the blue LED light source, it is effective. It is possible to suppress deterioration of the light-transmitting resin or phosphor and temperature quenching of the phosphor.

Furthermore, the light-transmitting resin layer in the present invention is excellent in moldability because the phosphor is dispersed in the light-transmitting resin. Therefore, the shape of the white conversion sheet having the light-transmitting resin layer can be various shapes such as a cylindrical shape, a spherical shape, and a semi-cylindrical shape. That is, since the white conversion sheet is excellent in moldability, it is possible to obtain light emitting devices having various shapes. For example, as shown in FIG. 3, light emission including a plurality of blue LED light sources 3 arranged on a substrate 2 and a cylindrical white conversion sheet 5 arranged to cover the plurality of blue LED light sources 3. The device 1 can be obtained. In FIG. 3, a part of the white conversion sheet is omitted.
On the other hand, when a color conversion unit containing a phosphor is provided for each blue LED light source as in the prior art, the color conversion unit constitutes a part of the blue LED light source. It is difficult to make various shapes like a sheet. In the conventional case, since a plurality of blue LED light sources are arranged in a dot shape in the light emitting device, it is difficult to obtain a light emitting device having various shapes as in the present invention.

Moreover, according to this invention, compared with the case where the color conversion part containing a fluorescent substance is provided for every blue LED light source like before, the area of a light-transmitting resin layer can be enlarged greatly. Therefore, it is easy to make the phosphor content uniform throughout the light-transmitting resin layer, and the phosphor content can be easily controlled. Moreover, such a relatively large area light-transmitting resin layer can be obtained, for example, by kneading and molding a phosphor in a light-transmitting resin, and can be easily formed.
Hereinafter, each structure of the light-emitting device of this invention is demonstrated.

1. White conversion sheet The white conversion sheet used in the present invention is provided for a plurality of blue LED light sources, and the blue light emitted from the blue LED chip is transmitted to the blue LED chips of the blue LED light source. It is arranged with a gap that can be converted into colored light. The white conversion sheet is a light-transmitting material containing a phosphor that converts blue light emitted from a blue LED chip into light having a color that can substantially obtain white light by mixing with the blue light. It has a resin layer.

As for the arrangement of the blue LED chip of the blue LED light source and the white conversion sheet, the white conversion sheet converts the blue light emitted from the blue LED chip into light of another color with respect to the blue LED chip of the blue LED light source. There is no particular limitation as long as the gap is obtained.
The blue LED chip refers to a member that emits blue light, a so-called blue light emitting layer. In the present invention, since the blue LED chip and the white conversion sheet are arranged with a predetermined gap, the blue LED chip and the white conversion sheet are not in direct contact with each other, and the light-transmitting resin and the phosphor are not in contact with each other. Deterioration and temperature quenching of the phosphor can be suppressed. If the blue LED chip and the white conversion sheet are arranged with a predetermined gap, the blue LED light source and the white conversion sheet may be in contact with each other.

The white conversion sheet may have at least a light-transmitting resin layer, but further includes a light introduction layer for making the blue light emitted from the blue LED chip of the blue LED light source parallel light or diffusing it. May be. Moreover, when the light transmissive resin layer does not have self-supporting property, the light transmissive resin layer may be formed on the substrate.
Hereinafter, each configuration of the white color conversion sheet will be described.

(1) Light transmissive resin layer The light transmissive resin layer used in the present invention substantially obtains white light from blue light emitted from a blue LED chip of a blue LED light source by mixing with the blue light. It contains a phosphor that converts light of a possible color.

  When the blue light emitted from the blue LED chip of the blue LED light source and the light that the phosphor absorbs and emits blue light are in a complementary color relationship, the blue light from the blue LED chip and the light from the phosphor White light can be obtained by mixing light emission. Therefore, the light transmissive resin layer needs to transmit blue light from the blue LED chip. That is, the light transmissive resin layer needs to be transparent to blue light from the blue LED chip, specifically, light having a wavelength of 420 nm to 490 nm.

  The transmittance of the light transmissive resin layer with respect to blue light can be adjusted by adjusting the phosphor content in the light transmissive resin layer and the film thickness of the light transmissive resin layer.

  The film thickness of the light-transmitting resin layer includes the phosphor content in the light-transmitting resin layer, the transmittance of the light-transmitting resin layer with respect to blue light, the visible light transmittance of the light-transmitting resin layer, and the purpose. It selects suitably according to the emission spectrum etc. which are taken.

  The light transmissive resin layer is a layer in which a phosphor is dispersed in a light transmissive resin. Hereinafter, the phosphor and the light transmissive resin will be described.

(I) Phosphor The phosphor used in the present invention is light of a color that can substantially obtain white light by mixing blue light emitted from a blue LED chip of a blue LED light source with the blue light. It is to convert to. In order to obtain white light, for example, blue light and yellow light may be mixed, blue light, yellow light and red light may be mixed, or blue light, green light and red light may be mixed. That is, as the phosphor, for example, a yellow phosphor that converts blue light into yellow light may be used, a yellow phosphor that converts blue light into yellow light, and a red phosphor that converts blue light into red light; Alternatively, a green phosphor that converts blue light into green light and a red phosphor that converts blue light into red light may be used. In particular, when a yellow phosphor and a red phosphor, or a green phosphor and a red phosphor are used, the color rendering can be improved.

The yellow phosphor used in the present invention is not particularly limited as long as it is excited by blue light emitted from a blue LED chip of a blue LED light source and emits yellow light. Specifically, it is preferable that the yellow phosphor emits light having a wavelength of 500 nm to 700 nm when excited with light having a wavelength of 420 nm to 490 nm. Examples of such yellow phosphors include yttrium aluminum garnet (YAG: Ce ³⁺ ) phosphor (YAG phosphor) activated by cerium, (Ca, Sr, Ba) ₂ SiO ₄ : Eu. ²⁺ , SrGa ₂ S ₄ : Eu ²⁺ , α-SiAlON: Eu ²⁺ , Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce ^{3+ and the} like.

  In the YAG-based phosphor, part or all of yttrium (Y) may be substituted with at least one element selected from the group consisting of Lu, Sc, La, Gd, and Sm, and aluminum (Al) Part or all may be substituted with Ga and / or In.

The YAG phosphor can adjust the emission wavelength of the phosphor by changing the composition.
For example, when part or all of Y of the YAG phosphor is substituted with Gd, the emission wavelength is shifted to the long wavelength side. In this case, the excitation light emission efficiency in a long wavelength region of 460 nm or more can be increased. As the amount of substitution of Gd increases, the emission peak wavelength shifts to a longer wavelength, and the emission wavelength shifts to the longer wavelength side as a whole. That is, by increasing the amount of substitution of Gd, it is possible to obtain a phosphor that emits yellowish (orange) light with strong redness. On the other hand, as the amount of substitution of Gd increases, the emission brightness of yellow (green) with strong blue tends to decrease.
For example, when a part of Al in the YAG phosphor is substituted with Ga, the emission wavelength is shifted to the short wavelength side. That is, in this case, a phosphor that emits yellow (green) light with strong bluishness can be obtained.

The green phosphor used in the present invention is not particularly limited as long as it is excited by blue light emitted from the blue LED chip of the blue LED light source and emits green light. Specifically, the green phosphor is preferably one that is excited by light having a wavelength of 420 nm to 490 nm and emits light having a wavelength of 500 nm to 600 nm. Examples of such a green phosphor include SrGa ₂ S ₄ : Eu ²⁺ .

Furthermore, the red phosphor used in the present invention is not particularly limited as long as it is excited by blue light emitted from a blue LED chip of a blue LED light source and emits red light. Specifically, the red phosphor is preferably one that is excited by light having a wavelength of 420 nm to 490 nm and emits light having a wavelength of 600 nm to 700 nm. Examples of such red phosphors include (Ca, Sr, Ba) S: Eu ²⁺ , (Ca, Sr, Ba) ₂ Si ₅ N ₈ : Eu ²⁺ , CaAlSiN ₃ : Eu ^{2+, and the} like. .

  The content of the phosphor in the light transmissive resin includes the film thickness of the light transmissive resin layer, the transmittance of the light transmissive resin layer with respect to blue light, the visible light transmittance of the light transmissive resin layer, and the light transmissive resin. It is appropriately selected according to the moldability of the layer and the target emission spectrum.

(Ii) Light-transmitting resin The light-transmitting resin used in the present invention is not particularly limited as long as it transmits blue light emitted from a blue LED chip of a blue LED light source. It is preferable that it is hard to deteriorate with respect to blue light.

  Moreover, the light transmissive resin may or may not have self-supporting properties. When the light-transmitting resin does not have self-supporting property, that is, when the light-transmitting resin layer does not have self-supporting property, as described later, the light-transmitting resin layer is formed on the substrate. It is preferable.

  As such a light transmissive resin, a thermosetting resin, a thermoplastic resin, a photocurable resin, and the like can be used. For example, an acrylic resin such as cycloolefin resin and polymethyl methacrylate, polyvinyl alcohol, polyimide, Examples thereof include polyarylate, polyethylene terephthalate, polysulfone, polyethersulfone, amorphous polyolefin, modified acrylic polymer, polystyrene, cellulose derivative, epoxy resin, urea resin, silicone resin, polycarbonate, and polyesters.

(Iii) Others The light transmissive resin layer in the present invention can be obtained by solidifying a resin composition in which a phosphor is dispersed in a light transmissive resin.
As a film forming method of the light transmissive resin layer, for example, a method of forming into a sheet shape using the resin composition or a method of applying the resin composition on a substrate can be used. Moreover, as a solidification method of a resin composition, it selects suitably according to the kind of light transmissive resin to be used, for example, methods, such as a heating, drying, and light irradiation, are used.

  When the light-transmitting resin layer contains a yellow phosphor and a red phosphor, or contains a plurality of color phosphors such as a green phosphor and a red phosphor, this light-transmitting resin The layer may be a single layer containing phosphors of a plurality of colors, or may be a layer in which layers each containing phosphors of each color are laminated.

  In the present invention, the emission spectrum obtained can be adjusted by adjusting the type of phosphor, the content of the phosphor in the light transmissive resin layer, the film thickness of the light transmissive resin layer, and the like. That is, it is possible to obtain a light emitting device capable of obtaining an arbitrary emission color among emission colors in the visible light region as well as white light.

(2) Light Introduction Layer In the present invention, a light introduction layer may be formed on the light transmissive resin layer. As this light introduction layer, for example, light (blue light) from a point light source (blue LED light source) may be parallel light, or blue light from a blue LED light source may be diffused. Good. When the light introduction layer converts the blue light from the blue LED light source into parallel light, the blue light emitted from the blue LED light source in all directions is converted into parallel light by the light introduction layer, and the blue light is transparent. It can be efficiently incident on the resin layer. In addition, when the light introduction layer diffuses blue light from the blue LED light source, light reflection on the surface of the light transmissive resin layer is suppressed, and blue light is efficiently incident on the light transmissive resin layer. Or white light can be efficiently extracted from the light-transmitting resin layer.

  As the light introduction layer for converting the blue light from the blue LED light source into parallel light, for example, a layer having a shape such as a convex lens, a lenticular lens, or a prism can be used. When the light introduction layer has a convex lens or prism shape, the convex lens or prism is preferably formed in an array.

  In the case where the light introduction layer is to convert the blue light from the blue LED light source into parallel light, the light introduction layer 6a is usually on the blue LED light source 3 side of the light-transmitting resin layer 4 as illustrated in FIG. Formed on the surface.

  Moreover, as a light introduction layer which diffuses the blue light from a blue LED light source, the refractive index was adjusted, for example with respect to the transparent resin layer and the medium which interposed between a white conversion sheet and a blue LED light source. A layer, a layer containing fine particles that diffuse light, or the like can be used.

  In the case where the light introduction layer diffuses blue light from the blue LED light source, the formation position of the light introduction layer is not particularly limited as long as it is on the light transmissive resin layer. For example, as shown in FIG. 5, the light introduction layer 6b may be formed on the surface of the light transmissive resin layer 4 on the blue LED light source 3 side, and although not shown, the light introduction layer is a blue LED having a light transmissive resin layer. You may form in the surface on the opposite side to the surface facing the light source.

  Moreover, both the light introduction layer which makes the blue light from a blue LED light source parallel light, and the light introduction layer which diffuses the blue light from a blue LED light source may be formed.

  It is preferable that such a light introduction layer has the transmittance | permeability comparable as the transmittance | permeability with respect to the blue light from the blue LED light source of the said transparent resin layer.

(3) Substrate In the present invention, a light transmissive resin layer may be formed on the substrate. In particular, when the light-transmitting resin layer does not have self-supporting properties, it is preferable that the light-transmitting resin layer is formed on the substrate.

It is preferable that the base material has a transmittance comparable to the transmittance of the light transmissive resin layer with respect to the blue light from the blue LED light source. Examples of such a base material include rigid base materials such as quartz glass, Pyrex (registered trademark), and synthetic quartz plates, or flexible materials such as resin films and optical resin plates. A flexible base material having
Especially, it is preferable that a base material is flexible base materials, such as a resin film. This is because the resin film is excellent in moldability and can be applied to various applications such as application to curved surfaces.

  As a formation position of a base material, it is normally set as the surface on the opposite side to the surface facing the blue LED light source of a transparent resin layer.

2. Blue LED light source The blue LED light source used in the present invention has a blue LED chip. The blue LED light source is not particularly limited, and a commonly used blue LED light source can be used. For example, the LED type may be any of a bullet type, a surface mount (SMD) type, a chip on board (COB) type, a power LED Face Up (FU) type, a power LED Face Down (FD) type, and the like. Good.

  FIG. 6 is a schematic cross-sectional view showing an example of a blue LED light source used in the present invention. In the blue LED light source 3 illustrated in FIG. 6, the wirings 13 and 14 are formed in a pattern on the base 12, and the blue LED chip 15 is formed on a part of the wiring (wiring 14). It is sealed with a frame 17 and a convex lens-shaped sealing material 18 made of a light transmitting resin. Further, the blue LED chip 15 is connected to the wiring 13 via the conductive wire 16.

  The blue LED chip is not particularly limited as long as it emits light in the blue wavelength region, and those generally used for blue LEDs can be used. Examples of the constituent material of the blue LED chip include InGaN and gallium nitride compound semiconductors such as GaN doped with an N-type dopant or a P-type dopant. Examples of the semiconductor structure include a homo structure having a MIS junction, a PIN junction, and a PN junction, a hetero structure, a double hetero structure, a single quantum well structure, and a multiple quantum well structure.

  The emission wavelength of the blue LED chip is preferably about 400 nm to 530 nm, more preferably about 420 nm to 490 nm in consideration of the complementary color relationship with the phosphor, deterioration of the light-transmitting resin, and the like. In order to improve excitation light emission efficiency, it is more preferable that it is about 450 nm-475 nm. The emission wavelength of the blue LED chip can be adjusted by appropriately selecting the constituent material, the mixed crystal degree, and the like.

The substrate is not particularly limited as long as it is generally used for LEDs. For example, a substrate in which a metal plate and an insulating layer are laminated, a resin such as ceramics, glass, sapphire, and epoxy resin. A substrate made of such as can be used.
As a constituent material of the metal plate, a metal having good thermal conductivity is used, and examples thereof include aluminum and copper.

  The conductive wire is not particularly limited as long as it has good ohmic properties with wiring, mechanical connectivity, electrical conductivity, and thermal conductivity. Examples of the constituent material of the conductive wire include metals such as gold, copper, platinum, and aluminum, and alloys thereof.

  Moreover, as wiring, it will not specifically limit if it is generally used for LED.

A sealing material is provided in order to protect a blue LED chip, a conductive wire, etc. from the outside.
As a constituent material of the sealing material, a light transmissive resin is usually used. Examples of the light transmissive resin include an epoxy resin, a urea resin, and a silicone resin. Since these are excellent in weather resistance, they are preferably used.

  The substrate on which the blue LED light source is provided is not particularly limited as long as it is generally used for LEDs, and the substrate may also serve as the substrate.

  In the present invention, a plurality of blue LED light sources are arranged. It is preferable that the plurality of blue LED light sources are regularly arranged at a predetermined interval. In addition, the number of blue LED light sources is not particularly limited as long as it is two or more.

3. Applications The light-emitting device of the present invention can be applied to, for example, traffic lights, display light sources for advertisements, illumination light sources such as illumination devices, and light sources for display devices such as backlights of liquid crystal display devices.
In particular, since the white conversion sheet in the present invention is excellent in moldability, light emitting devices having various shapes can be obtained.

4). Others The medium filled between the blue LED light source and the white conversion sheet is not particularly limited.

B. White conversion sheet The white conversion sheet of the present invention is used in the above-described light-emitting device, and has a color that substantially converts white light emitted from a blue LED chip of a blue LED light source into white light by mixing with the blue light. It has a light-transmitting resin layer containing a phosphor that converts light.
The white conversion sheet has been described in detail in the above section “A. Light-emitting device”, and thus description thereof is omitted here.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

Hereinafter, the present invention will be specifically described with reference to examples.
[Example]
1. Preparation of White Conversion Sheet Y ₅ Al ₁₂ O ₅ : Ce was kneaded with PMMA resin pellets at 10 wt% to prepare a pellet in which a phosphor and a light transmissive resin were mixed. This phosphor / light-transmitting resin mixed pellet was processed into a sheet having a thickness of 300 μm to produce a white conversion sheet of 10 cm × 10 cm.

2. Preparation of Light Emitting Device A device in which nine blue LED light sources (NSPA510S manufactured by Nichia Corporation) were arranged was prepared. With respect to the blue LED chip of these blue LED light sources, the above white conversion sheet was disposed with a gap of about 3 mm.

3. Evaluation FIG. 7 shows a light emission spectrum of the white LED sheet (460 nm) of the white conversion sheet thus obtained by light excitation. The blue light from the blue LED chip that passed through the white conversion sheet and the yellow fluorescence of Y ₅ Al ₁₂ O ₅ : Ce were mixed, and white light was observed.

It is a schematic plan view which shows an example of the light-emitting device of this invention. It is the sectional view on the AA line of FIG. It is a schematic perspective view which shows the other example of the light-emitting device of this invention. It is a schematic sectional drawing which shows the other example of the light-emitting device of this invention. It is a schematic sectional drawing which shows the other example of the light-emitting device of this invention. It is a schematic sectional drawing which shows an example of the blue LED light source used for this invention. It is a graph which shows the emission spectrum of the white conversion sheet of an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Light-emitting device 2 ... Board | substrate 3 ... Blue LED light source 4 ... Light-transmitting resin layer 5 ... White conversion sheet 6a, 6b ... Light introduction layer

Claims (8)

A plurality of blue LED light sources having blue LED chips;
Provided for the plurality of blue LED light sources, and disposed with a gap that can convert blue light emitted from the blue LED chip into light of another color with respect to the blue LED chip, blue light, the light transmitting resin layer containing a phosphor to convert substantially colors capable of obtaining white light by mixing with the blue light, and the blue of the light transmitting resin layer A white color conversion sheet formed on the LED light source side and having a light introduction layer for making the blue light from the blue LED light source parallel light ;
A light emitting device comprising:   The light emitting device according to claim 1, wherein the phosphor is a yellow phosphor that converts the blue light into yellow light. The light emitting device according to claim 1, wherein the phosphor includes phosphors of a plurality of colors. The phosphor is a yellow phosphor which converts the blue light into yellow light, and light-emitting device according to claim 3 you being a red phosphor that converts the blue light into red light. The light emitting device according to claim 3 , wherein the phosphor is a green phosphor that converts the blue light into green light and a red phosphor that converts the blue light into red light. The light-emitting device according to any one of claims 3 to 5, wherein the light-transmitting resin layer is formed by laminating layers each containing the plurality of types of phosphors. .   The light emitting device according to any one of claims 3 to 6, wherein the phosphors in the light transmissive resin layer are uniformly dispersed. A color that is used in the light-emitting device according to any one of claims 1 to 7, and that blue light emitted from a blue LED chip of a blue LED light source is substantially white light by color mixture with the blue light. A light-transmitting resin layer containing a phosphor that converts the light into the light , and light introduction that is formed on the blue LED light source side of the light-transmitting resin layer and makes the blue light from the blue LED light source parallel light A white conversion sheet comprising a layer .

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