JP2016154205A - Light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-emitting device which enables the materialization of a wide color reproduction range in the case of arranging an image display device.SOLUTION: A light-emitting device comprises: a light-emitting element having a light emission peak wavelength of 440-460 nm; a first fluorescent material operable to emit fluorescence having a light emission peak wavelength of 640-670 nm, and expressed by the composition formula (I) below; and a second fluorescent material operable to emit fluorescence having a light emission peak wavelength of 520-550 nm. Supposing that the maximum light emission intensity in a range of 440-460 nm is 100%, the light-emitting device has a light emission spectra of which the average light emission intensity in a range of 590-610 nm is 7.5% or less. MMAlN: Eu(I) (In the formula, Mrepresents at least one element selected from a group consisting of Ca, Sr and Ba, Mrepresents at least one element selected from a group consisting of Li, Na and K, and x, y and z satisfy: 0.5≤x≤1.5; 0.5≤y≤1.2; and 3.5≤z≤4.5.)SELECTED DRAWING: Figure 5

Description

  The present disclosure relates to a light emitting device.

Light emission capable of emitting white light by combining a light emitting diode (LED) that emits blue light, a phosphor that emits green when excited by the blue light, and a phosphor that emits red light Equipment has been developed. For example, Patent Document 1 discloses a phosphor that emits green light and is a nitride or oxynitride (β sialon phosphor) having a β-type Si ₃ N ₄ crystal structure. A light emitting device that emits white light by mixing the light emitted from the LED and the phosphor by exciting the phosphor and the red phosphor CaSiAlN ₃ : Eu with a blue LED is disclosed.

Patent Document 2 discloses a light emitting element that emits blue light, a phosphor that emits green light ((Sr, Ba) ₂ SiO ₄ : Eu) excited by the light emitting element, and a phosphor that emits red light (CaAlSiN ₃ : A light emitting device that is combined with Eu) is disclosed. The (Sr, Ba) ₂ SiO ₄ : Eu phosphor can change the peak wavelength from 520 nm to 600 nm and can adjust the color reproduction range, so that it can obtain a wide color reproduction range. ing.

Furthermore, as a conventional technique that focuses on color reproducibility (for example, NTSC ratio) in a liquid crystal display device (LCD), for example, Patent Document 3 discloses a backlight including a green phosphor having a spectral peak in the range of 505 nm to 535 nm. A liquid crystal display device using a light source is disclosed. It is disclosed that the green phosphor contains any of europium, tungsten, tin, antimony and manganese as an activator. Furthermore, MgGa ₂ O ₄ : Mn, Zn ₂ SiO ₄ : Mn and the like are described as specific examples of the green phosphor.

JP 2008-303331 A JP 2007-027796 A JP 2003-121838 A

In the light emitting device described in Patent Document 1, a β sialon phosphor that is a green phosphor and a CaAlSiN ₃ : Eu phosphor or a (Ca, Sr, Ba) ₂ Si ₅ N ₈ : Eu phosphor that is a red phosphor. However, these phosphors have a relatively large half-value width, so that an intermediate component between the green and red components increases. For this reason, it is difficult to accurately cover the color reproduction range in the NTSC ratio, and there is a concern that it is difficult to realize a more accurate image display.
Further, in the light emitting device described in Patent Document 2, since the half width of the green phosphor is wide, there is a concern that it is difficult to accurately cover the color reproduction range.
Furthermore, when the green phosphor contained in the backlight light source described in Patent Document 3 is used together with a light emitting device having a peak wavelength of 430 nm or more and 480 nm or less, the excitation wavelength of the phosphor does not match the peak wavelength of the light emitting device, There is a concern that it is difficult to sufficiently increase the luminous efficiency.

  An embodiment according to the present disclosure has been made to solve the above-described problem. One embodiment according to the present disclosure aims to provide a light emitting device capable of realizing a wide color reproduction range when an image display device is configured.

Specific means for solving the above-described problems are as follows, and embodiments according to the present disclosure include the following aspects.
According to a first aspect of the present disclosure, a light emitting element having an emission peak wavelength of 440 nm or more and 460 nm or less emits fluorescence having an emission peak wavelength in a range of 640 nm or more and 670 nm or less, and is represented by the following composition formula (I): 590 nm when one phosphor and a second phosphor that emits fluorescence having an emission peak wavelength in the range of 520 nm to 550 nm and the maximum emission intensity in the range of 440 nm to 460 nm is 100%. The light-emitting device has an emission spectrum in which the average emission intensity in the range of 610 nm or less is 7.5% or less.
M ^a _x M ^b _y Al ₃ N _z : Eu (I)

In the above formula (I), M ^a is at least one element selected from the group consisting of Ca, Sr and Ba, and M ^b is at least one selected from the group consisting of Li, Na and K. It is a seed element, and x, y, and z satisfy 0.5 ≦ x ≦ 1.5, 0.5 ≦ y ≦ 1.2, and 3.5 ≦ z ≦ 4.5, respectively.

  According to a second aspect of the present disclosure, a light emitting device having an emission peak wavelength of 440 nm or more and 460 nm or less emits fluorescence having an emission peak wavelength in a range of 640 nm or more and 670 nm or less, and is represented by the composition formula (I). 590 nm when one phosphor and a second phosphor that emits fluorescence having an emission peak wavelength in the range of 520 nm to 550 nm and the maximum emission intensity in the range of 520 nm to 550 nm is 100%. The light-emitting device has an emission spectrum in which the average emission intensity in the range of 610 nm or less is 33% or less.

  According to an embodiment of the present disclosure, it is possible to provide a light emitting device capable of realizing a wide color reproduction range when an image display device is configured.

It is a schematic sectional drawing which shows an example of the light-emitting device which concerns on this embodiment. It is a schematic sectional drawing which shows another example of the light-emitting device which concerns on this embodiment. It is a figure which illustrates the emission spectrum of the red fluorescent substance which concerns on this embodiment. It is a figure which illustrates the emission spectrum of the green fluorescent substance which concerns on this embodiment. It is a figure which illustrates the emission spectrum of the light-emitting device which concerns on an Example and a comparative example with the relative intensity normalized by the maximum light emission intensity in 440 nm or more and 460 nm or less. It is a figure which illustrates the emission spectrum of the light-emitting device which concerns on an Example and a comparative example with the relative intensity normalized with the maximum light emission intensity in 520 nm or more and 550 nm or less.

  Hereinafter, a light-emitting device according to the present disclosure will be described based on embodiments. However, the embodiment described below exemplifies the technical idea of the present invention, and the present invention is not limited to the following. The relationship between the color name and the chromaticity coordinates, the relationship between the wavelength range of light and the color name of monochromatic light, and the like comply with JIS Z8110. In addition, in the present specification, the content of each component in the composition is the sum of the plurality of substances present in the composition unless there is a specific indication when there are a plurality of substances corresponding to each component in the composition. Means quantity.

[Light emitting device]
The light emitting device of this embodiment emits fluorescence having a light emission peak wavelength in a range of 640 nm to 670 nm and a light emitting element having a light emission peak wavelength of 440 nm to 460 nm, and is represented by the following composition formula (I): And a second phosphor that emits fluorescence having an emission peak wavelength in the range of 520 nm to 550 nm, and the maximum emission intensity in the range of 440 nm to 460 nm is 100%, 590 nm or more It is a light emitting device having an emission spectrum having an average emission intensity in the range of 610 nm or less of 7.5% or less. In addition, the light emitting device of the present embodiment has a light emission spectrum in which the average light emission intensity in the range of 590 nm to 610 nm is 33% or less when the maximum light emission intensity in the range of 520 nm to 550 nm is 100%. It is.
M ^a _x M ^b _y Al ₃ N _z : Eu (I)

In the above formula (I), M ^a is at least one element selected from the group consisting of Ca, Sr and Ba, and M ^b is at least one selected from the group consisting of Li, Na and K. It is a seed element, and x, y, and z satisfy 0.5 ≦ x ≦ 1.5, 0.5 ≦ y ≦ 1.2, and 3.5 ≦ z ≦ 4.5, respectively.

  By using a light emitting element having a specific emission peak wavelength as an excitation light source and combining a red phosphor having a specific chemical composition and a green phosphor, the amount of components in the yellow-red region in the emission spectrum becomes a certain amount or less. . Such a light-emitting device can make the spectrum of mixed-color light emitted from this light-emitting device more excellent in color separation than the light emission spectrum of a conventional light-emitting device, and expand the color reproduction range when an image display device is configured. Is possible.

  By applying the light emitting device of this embodiment to an image display device, the color reproduction range of the image display device can be expanded. The color reproduction range is evaluated using, for example, the NTSC ratio as an index. The NTSC ratio is red (0.670, 0.330) as chromaticity coordinates (x, y) in the XYZ color system chromaticity diagram of each color of red, green, blue, and each color defined by the NTSC (National Television System Committee). ), Green (0.210, 0.710), and blue (0.140, 0.080), the ratio to the area of a triangle obtained by connecting three points. By using the light emitting device of the present embodiment, the color reproduction range can be made wider than when a conventional light emitting device is used.

The emission spectrum of the light emitting device has an average light emission intensity of 7.5% or less in the yellow-red region of 590 nm or more and 610 nm or less when the maximum light emission intensity in the range of 440 nm or more and 460 nm or less is 100%. From the viewpoint of expanding the color reproduction range, 7.0% or less is preferable.
The light emission spectrum of the light emitting device is such that the average light emission intensity in the yellow-red region of 590 nm to 610 nm is 33% or less when the maximum light emission intensity in the range of 520 nm to 550 nm is 100%. From the viewpoint of expanding the color reproduction range, it is preferably 30% or less.
The average emission intensity in the range of 590 nm or more and 610 nm or less can be adjusted, for example, by appropriately selecting the configuration of the first phosphor and the second phosphor.
The average emission intensity in a specific wavelength range is an arithmetic average value of the emission intensity in that wavelength range in the emission spectrum. That is, in the emission spectrum, the emission intensity is measured every 1 nm in the wavelength range, and the total of the measured emission intensity is divided by the number of measurements.

From the viewpoint of expanding the color reproduction range of the image display device, the emission spectrum of the light emitting device has an average emission intensity in a blue-green region of 480 nm to 500 nm when the maximum emission intensity in the range of 440 nm to 460 nm is 100%. It is preferably 7% or less, and more preferably 6.5% or less.
The emission spectrum of the light emitting device is the average emission intensity in the blue-green region of 480 nm to 500 nm when the maximum emission intensity in the range of 520 nm to 550 nm is 100% from the viewpoint of expanding the color reproduction range of the image display device. Is preferably 40% or less, more preferably 30% or less.
The average emission intensity in the range of 480 nm to 500 nm can be adjusted by appropriately selecting the configuration of the first phosphor and the second phosphor, for example.

  The light emitted from the light emitting device is a mixed color of the light emitted from the light emitting element and the fluorescence emitted from the first phosphor and the second phosphor. For example, the chromaticity coordinates defined in CIE1931 are x = 0.220. It is preferable that the light is in the range of 0.340 or less and y = 0.160 or more and 0.340 or less, and x = 0.220 or more and 0.330 or less and y = 0.170 or more and 0.330 or less. More preferably, the light is included in the range.

  The form of the light emitting device is not particularly limited, and can be appropriately selected from commonly used forms. Examples of the light emitting device include a pin penetration type and a surface mounting type. In general, the pin through type refers to a type in which a light emitting device is fixed by penetrating leads (pins) of the light emitting device through through holes provided in a mounting substrate. The surface mount type refers to a type in which the lead of the light emitting device is fixed on the surface of the mounting substrate.

An example of the light emitting device 100 according to the present embodiment will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view 100 showing an example of a light emitting device according to the present invention. The light emitting device 100 is an example of a surface mount type light emitting device.
The light-emitting device 100 emits light on the short wavelength side of visible light (for example, in a range of 380 nm to 485 nm), and the light-emitting element 10 includes a gallium nitride compound semiconductor light-emitting element 10 having an emission peak wavelength of 440 nm to 460 nm. And a molded body 40 on which is mounted. The molded body 40 is formed by integrally molding the first lead 20 and the second lead 30 and a thermoplastic resin or a thermosetting resin. The molded body 40 has a recess having a bottom surface and side surfaces, and the light emitting element 10 is placed on the bottom surface of the recess. The light emitting element 10 has a pair of positive and negative electrodes, and the pair of positive and negative electrodes are electrically connected to the first lead 20 and the second lead 30 through wires 60, respectively. The light emitting element 10 is covered with a fluorescent member 50. The fluorescent member 50 preferably includes a thermosetting resin such as an epoxy resin, a silicone resin, an epoxy-modified silicone resin, or a modified silicone resin. The fluorescent member 50 includes a red fluorescent material (first fluorescent material 71), a green fluorescent material (second fluorescent material 72), and a resin as a fluorescent material 70 for converting the wavelength of light from the light emitting element 10.

  The fluorescent member 50 is formed by being filled with a translucent resin or glass so as to cover the light emitting element 10 placed in the recess of the light emitting device 100. In consideration of ease of manufacture, the material of the fluorescent member is preferably a translucent resin. As the translucent resin, a silicone resin composition is preferably used, but an insulating resin composition such as an epoxy resin composition or an acrylic resin composition can also be used. Moreover, although the 1st fluorescent substance 71 and the 2nd fluorescent substance 72 are contained in the fluorescent member 50, another material can also be added suitably. For example, by including a light diffusing material, the directivity from the light emitting element can be relaxed and the viewing angle can be increased.

  The fluorescent member 50 functions not only as a wavelength conversion member including the phosphor 70 but also as a member for protecting the light emitting element 10, the first phosphor 71, and the second phosphor 72 from the external environment. In FIG. 1, the first phosphor 71 and the second phosphor 72 are unevenly distributed in the phosphor member 50. Thus, by arranging the first phosphor 71 and the second phosphor 72 close to the light emitting element 10, the wavelength of light from the light emitting element 10 can be efficiently converted, and the light emission efficiency is excellent. It can be a light emitting device. In addition, arrangement | positioning with the fluorescent member 50 containing the 1st fluorescent substance 71 and the 2nd fluorescent substance 72, and the light emitting element 10 is not limited to the form which arranges them closely, but the 1st fluorescent substance In consideration of the effect of heat on 71 and the second phosphor 72, the light emitting element 10 and the first phosphor 71 and the second phosphor 72 are spaced apart from each other in the phosphor member 50. You can also. In addition, by mixing the first phosphor 71 and the second phosphor 72 in the entire fluorescent member 50 at a substantially uniform ratio, it is possible to obtain light in which color unevenness is further suppressed.

In FIG. 1, the first phosphor 71 and the second phosphor 72, which are the phosphors 70, are shown in a mixed state, but the respective phosphors may be arranged as shown in FIG. .
FIG. 2 is a schematic cross-sectional view showing another example of the light emitting device according to the present embodiment. In FIG. 2, the first phosphor 71 and the second phosphor 72 are arranged in this order from the side closer to the light emitting element 10. Thereby, it can suppress that light emission of the 2nd fluorescent substance 72 excites the 1st fluorescent substance 71. FIG. Further, by arranging the second phosphor 72 on the top, it is possible to easily extract the light emitted from the second phosphor 72 out of the light emitting device. Thus, it is considered that the light emission efficiency of the light emitting device is further improved.

(Light emitting element)
The emission peak wavelength of the light emitting element is in the range of 440 nm to 460 nm. By using a light emitting element having an emission peak wavelength in this range as an excitation light source, it is possible to configure a light emitting device that emits mixed light of light from the light emitting element and fluorescence from the phosphor. Furthermore, since light emitted from the light emitting element to the outside can be used effectively, loss of light emitted from the light emitting device can be reduced, and a highly efficient light emitting device can be obtained.

The half width of the emission spectrum of the light emitting element is not particularly limited. The half width can be set to 30 nm or less, for example.
A semiconductor light emitting element is preferably used as the light emitting element. By using a semiconductor light emitting element as a light source, it is possible to obtain a stable light emitting device with high efficiency, high output linearity with respect to input, and strong against mechanical shock.
As a semiconductor light emitting element, for example, a blue color using a nitride semiconductor (In _X Al _Y Ga _1- XYN, where X and Y satisfy 0 ≦ X, 0 ≦ Y, and X + Y ≦ 1). A semiconductor light emitting element that emits green light or the like can be used.

(Phosphor)
The light emitting device includes at least one first phosphor that absorbs light emitted from the light emitting element and emits red light and at least one second phosphor that emits green light. A red phosphor having a specific chemical composition is used for the first phosphor, and the second phosphor is appropriately selected from green phosphors that emit fluorescence having an emission peak wavelength in the range of 520 nm to 550 nm. A phosphor can be used. By appropriately selecting the emission peak wavelength, emission spectrum and the like of the second phosphor, it is possible to make the characteristics such as the color reproduction range and color rendering property of the light emitting device within a desired range.

The first phosphor The light emitting device emits fluorescence having an emission peak wavelength in a range of 640 nm to 670 nm and includes at least one first phosphor represented by the following composition formula (I).
M ^a _x M ^b _y Al ₃ N _z : Eu (I)

In the formula, M ^a is at least one element selected from the group consisting of Ca, Sr and Ba, preferably including at least one of Sr and Ca, and more preferably including at least Sr. ^Mb is at least one element selected from the group consisting of Li, Na, and K, and preferably contains at least Li.

  x satisfies 0.5 ≦ x ≦ 1.5 and preferably satisfies 0.6 ≦ x ≦ 1.2. y satisfies 0.5 ≦ y ≦ 1.2 and preferably satisfies 0.6 ≦ y ≦ 1.1. z satisfies 3.5 ≦ z ≦ 4.5 and preferably satisfies 3.6 ≦ z ≦ 4.4.

  The first phosphor emits red fluorescence. The half width in the emission spectrum of the first phosphor is not particularly limited, and is preferably 70 nm or less, and more preferably 65 nm or less, for example. The emission spectrum of the first phosphor is preferably such that the average emission intensity in the range of 590 nm to 610 nm is 10% or less, more preferably 8% or less, assuming that the maximum emission intensity is 100%. preferable.

The first phosphor preferably has a reflectance at 460 nm of 53% or less, and more preferably 52% or less. When the reflectance at 460 nm of the first phosphor is not less than a predetermined value, for example, the light emission efficiency tends to be further improved.
The reflectance of the first phosphor is measured using a spectrophotometer for the solid sample, and CaHPO ₄ is used as the reference for the reflectance.

The average particle diameter of the first phosphor included in the light emitting device is not particularly limited and can be appropriately selected depending on the purpose and the like. The average particle diameter of the first phosphor is preferably 2 μm or more and 35 μm or less, and more preferably 3 μm or more and 30 μm or less from the viewpoint of light emission efficiency.
The average particle diameter of the first phosphor is a numerical value called “Fisher Sub Sieve Sizer's No.” and is measured using an air permeation method.
The light emitting device may contain the first phosphor alone or in combination of two or more.

  The content of the first phosphor in the light emitting device can be appropriately selected according to the purpose and the like. For example, the content of the first phosphor can be 0.1 parts by weight or more and 50 parts by weight or less with respect to 100 parts by weight of the resin contained in the fluorescent member, and can be 1 part by weight or less 30 parts by weight. preferable.

Second phosphor The light emitting device includes at least one second phosphor that emits fluorescence having an emission peak wavelength in a range of 520 nm to 550 nm.
The second phosphor preferably has a half-value width of an emission spectrum of 70 nm or less, and more preferably 65 nm or less. The second phosphor preferably has an average emission intensity in the range of 590 to 610 nm of 30% or less, more preferably 27% or less, assuming that the maximum emission intensity in the emission spectrum is 100%. preferable.

The second phosphor is a β sialon phosphor represented by the following composition formula (IIa), a silicate phosphor represented by the following composition formula (IIb), and a halosilicate phosphor represented by the following composition formula (IIc) And at least one selected from the group consisting of thiogallate phosphors represented by the following composition formula (IId).
Si _6-w Al _w O _w N _8-w : Eu (IIa)
(In the formula, w satisfies 0 <w ≦ 4.2.)
(Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu (IIb)
(Ca, Sr, Ba) ₈ MgSi ₄ O ₁₆ (F, Cl, Br) ₂ : Eu (IIc)
(Ba, Sr, Ca) Ga ₂ S ₄ : Eu (IId)
In the composition formula (IIa), z preferably satisfies 0.01 <z <2.
The light emitting device may contain the second phosphor alone or in combination of two or more.

The average particle size of the second phosphor included in the light emitting device is not particularly limited and can be appropriately selected according to the purpose and the like. The average particle diameter of the second phosphor is preferably 2 μm or more and 35 μm or less, and more preferably 5 μm or more and 30 μm or less from the viewpoint of light emission efficiency.
The average particle size of the second phosphor is measured in the same manner as the average particle size of the first phosphor.

  The content of the second phosphor in the light emitting device can be appropriately selected depending on the purpose and the like. For example, the content of the second phosphor can be 1 part by weight or more and 70 parts by weight or less with respect to 100 parts by weight of the resin contained in the fluorescent member, and is preferably 2 parts by weight or more and 50 parts by weight or less. .

  The content ratio of the first phosphor and the second phosphor in the light emitting device is not particularly limited as long as desired light emission characteristics can be obtained, and can be appropriately selected according to the purpose and the like. For example, the content ratio of the first phosphor to the second phosphor (first phosphor / second phosphor) can be 0.01 or more and 10 or less, and 0.1 or more and 1 on a weight basis. The following is preferred.

Other phosphors The light-emitting device may include other phosphors other than the first phosphor and the second phosphor as necessary. Other phosphors include (Y, Gd, Tb, Lu) ₃ (Al, Ga) ₅ O ₁₂ : Ce, Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce, CaSc ₂ O ₄ : Ce, (La, Y ) ₃ Si ₆ N ₁₁ : Ce, (Ca, Sr, Ba) ₃ Si ₆ O ₉ N ₄ : Eu, (Ca, Sr, Ba) ₃ Si ₆ O ₁₂ N ₂ : Eu, (Ba, Sr, Ca) Si ₂ O ₂ N ₂ : Eu, (Sr, Ca) AlSiN ₃ : Eu, (Ca, Sr, Ba) ₂ Si ₅ N ₈ : Eu, (Ca, Sr, Ba) S: Eu, K ₂ (Si, Ti, Ge) F ₆ : Mn and the like can be mentioned. When the light-emitting device contains other phosphors, the content can be appropriately selected according to the purpose and the like, for example, 10% by weight or less with respect to the total amount of the first phosphor and the second phosphor. Yes, up to 1% by weight.

  The method for producing the phosphor is not particularly limited, and can be appropriately selected from known means. For example, it can be manufactured as follows. A single element or oxide, carbonate, nitride, chloride, fluoride, sulfide or the like contained in the phosphor composition is used as a raw material, and each of these raw materials is weighed so as to have a predetermined composition ratio. Further, an additive material such as a flux is appropriately added to the raw material, and mixed by a wet or dry method using a mixer. Thereby, it becomes possible to promote solid-phase reaction and form particles of uniform size. The mixer may be a ball mill that is usually used industrially, or a crusher such as a vibration mill, a roll mill, or a jet mill. The specific surface area can be increased by pulverization using a pulverizer. Moreover, in order to keep the specific surface area of the powder within a certain range, classification is performed using a wet type separator such as a sedimentation tank, a hydrocyclone, and a centrifugal separator, and a dry classifier such as a cyclone and an air separator. You can also The mixed raw materials are packed in a crucible made of SiC, quartz, alumina, BN or the like, and fired in an inert atmosphere such as argon or nitrogen, or in a reducing atmosphere containing hydrogen. Firing is performed at a predetermined temperature and time. The fired product is pulverized, dispersed, filtered, etc. to obtain the desired phosphor powder. Solid-liquid separation can be performed by industrially used methods such as filtration, suction filtration, pressure filtration, centrifugation, and decantation. Drying can be performed by industrially used apparatuses such as a vacuum dryer, a hot-air heating dryer, a conical dryer, and a rotary evaporator.

(Fluorescent material)
The light emitting device can include, for example, a fluorescent member that includes a phosphor and a resin and covers the light emitting element. Examples of the resin constituting the fluorescent member include thermoplastic resins and thermosetting resins. Specific examples of the thermosetting resin include modified silicone resins such as epoxy resins, silicone resins, and epoxy-modified silicone resins.
The fluorescent member may contain other components as needed in addition to the phosphor and the resin. Examples of other components include fillers such as silica, barium titanate, titanium oxide, and aluminum oxide, light stabilizers, and colorants. When the fluorescent member contains other components, the content thereof is not particularly limited and can be appropriately selected depending on the purpose and the like. For example, when a filler is included as another component, the content thereof can be 0.01 parts by weight or more and 20 parts by weight or less with respect to 100 parts by weight of the resin.

  Examples of the present invention will be specifically described below, but the present invention is not limited to these examples.

(Phosphor)
Prior to the production of the light emitting device, red phosphors and green phosphors shown in the following table were prepared as phosphors for Examples and Comparative Examples, respectively.
Phosphors 1 and 2 were prepared as red phosphors as the first phosphor.
(Phosphor 1)
The phosphor 1 is a phosphor represented by M ^a _x M ^b _y Al ₃ N _z : Eu, and M ^a = Sr, M ^b = Li, x = 1, y = 1, and z = 4 are designed values. And SrN _n (n = 2/3 equivalent), Li ₃ N, AlN and EuF ₃ were used as raw materials. These raw materials were weighed and mixed in a glove box in an inert atmosphere so that Sr: Eu: Li: Al = 0.993: 0.007: 1.17: 3 to obtain a mixture. Here, Li is likely to be scattered during firing, so it was blended more than the theoretical value. The mixture was filled in a crucible and heat-treated at 1100 ° C. for 3 hours in a N ₂ / H ₂ mixed gas atmosphere.
The resulting powder was measured XRD for, it was confirmed that a compound represented by SrLiAl ₃ N _4. The emission peak wavelength of fluorescence was 653 nm, and the reflectance at 460 nm was 51.6%.
This phosphor was used as phosphor 1 (hereinafter sometimes abbreviated as “SLAN”).

(Phosphor 2)
As the phosphor 2, a phosphor having an emission peak wavelength at 663 nm and represented by CaAlSiN ₃ : Eu (hereinafter sometimes abbreviated as “CASN”) was used.

Phosphors 3 to 9 were prepared as green phosphors as the second phosphor.
(Phosphor 3 to 5)
The phosphors 3 to 5 are all β-sialon phosphors represented by Si _6-w Al _w O _w N _8-w : Eu (w satisfies 0 <w ≦ 4.2), and w value There are three types of phosphors with different emission peak wavelengths due to the change. The phosphor 3 has a light emission peak wavelength of 540 nm, the phosphor 4 has a light emission peak wavelength of 535 nm, and the phosphor 5 has a light emission peak wavelength of 531 nm.

(Phosphor 6)
The phosphor 6 was a thiogallate phosphor represented by SrGa ₂ S ₄ : Eu, and the emission peak wavelength was 535 nm.

(Phosphor 7)
The phosphor 7 is a chlorosilicate phosphor represented by Ca ₈ MgSi ₄ O ₁₆ Cl _{2 -δ} : Eu (δ satisfies 0 ≦ δ ≦ 1 and indicates a composition shift of Cl), and has an emission peak wavelength. Was 522 nm.

(Phosphor 8)
The phosphor 8 is a silicate phosphor represented by (Ba, Sr) ₂ SiO ₄ : Eu, and the emission peak wavelength was 523 nm.

(Phosphor 9)
The phosphor 9 is an aluminate phosphor represented by Y ₃ (Al, Ga) ₅ O ₁₂ : Ce (hereinafter sometimes abbreviated as “YAGG”), and the emission peak wavelength was 543 nm.

  The emission peak wavelength and half-value width of each phosphor are shown in the table below. 3 and 4 show emission spectra showing the emission intensity with respect to the wavelength when the maximum emission intensity of each phosphor is 100%.

  Phosphors 3 to 9 are phosphors having an emission peak wavelength in the range of 520 nm to 550 nm. The phosphors 3 to 8 have a half width of 70 nm or less, whereas the phosphor 9 has a half width of more than 70 nm.

(Examples 1 to 6, Comparative Examples 1 and 2)
Production of Light-Emitting Device A light-emitting device was prepared by combining a phosphor shown in Table 2 with a blue light-emitting LED (light-emitting element) having an emission wavelength of 452 nm.
A phosphor blended so that the chromaticity coordinates of the mixed-color light emitted from the light-emitting device are in the vicinity of x = 0.250 and y = 0.220 is added to the silicone resin, mixed and dispersed, and then defoamed for further fluorescence. A body-containing resin composition was obtained. Next, the phosphor-containing resin composition was poured and filled on the light emitting element, and further heated to cure the resin composition. Each of the light emitting devices was manufactured through such a process.

The emission spectrum which shows the relative intensity with respect to the wavelength of the light-emitting device which concerns on Examples 1-6 and Comparative Examples 1 and 2 is shown to FIG. FIG. 5 is an emission spectrum using relative intensity based on the maximum emission intensity in the range of 440 nm to 460 nm as a reference (100%). FIG. 6 is an emission spectrum using relative intensity based on the maximum emission intensity in the range of 520 nm to 550 nm as a reference (100%).
The average emission intensity in the range of 480 to 500 nm and the range of 590 to 610 nm when the maximum emission intensity in the range of 440 to 460 nm in the emission spectrum of each light-emitting device was defined as 100% was calculated. The results are shown in Table 2 below.

(Relative NTSC ratio)
The NTSC ratio of the obtained light emitting device was determined as follows, and the NTSC ratio of each example and comparative example was calculated as a relative NTSC ratio with the NTSC ratio of comparative example 1 as 100% of the reference.
The color reproduction range and NTSC ratio when the light from the light emitting device is displayed as a display can be obtained from the chromaticity of each color at the time of passing through the color filter and extracting blue light, green light and red light, respectively. .
When the color filter is applied to a light emitting device using a blue LED and a YAG: Ce phosphor, a simulation is performed for a case where a general color filter having an NTSC ratio of about 70% is used. The ratio was calculated. The results are shown in Table 2 below.

  In the same manner as above, the average emission intensity in the range of 480 to 500 nm and the average emission intensity in the range of 590 to 610 nm when the maximum emission intensity in the range of 520 nm to 550 nm in the emission spectrum of each light emitting device was set to 100% was calculated. For comparison, the relative NTSC ratio is also shown. The results are shown in Table 3 below.

  The light emitting device of Example 1 uses the phosphor 1 having an emission peak wavelength of 653 nm and a half-value width of 57 nm as the first phosphor, and the emission peak wavelength of 544 nm and the half-value width of 56 nm as the second phosphor. The phosphor 3 is used. On the other hand, the light emitting device of Comparative Example 1 uses the phosphor 2 having an emission peak wavelength of 663 nm and a half-value width of 89 nm as the first phosphor, and the phosphor as in Example 1 as the second phosphor. 3 is used.

  As shown in “Relative NTSC ratio” in Table 2, the light emitting device of Example 1 has a larger NTSC ratio and a wider color reproduction range than the light emitting device of Comparative Example 1. The reason is considered as follows. The half width of the emission spectrum of the phosphor 1 is narrower than that of the phosphor 2 due to the composition and crystal structure of the compound. As described above, since the half-value width of the emission spectrum of the red phosphor is narrowed, the light emitting device of Example 1 has an average emission intensity of, for example, a comparative example of the emission components of the emission spectrum of 590 nm to 610 nm. When the maximum emission intensity of 440 nm or more and 460 nm or less is used as a reference, it is 7.5% or less, and when the maximum emission intensity of 520 nm or more and 550 nm or less is used as a reference, it is 33% or less. It is running low. Due to the difference in emission spectrum, it is considered that the light emitting device of Example 1 has a wider color reproduction range than the light emitting device of Comparative Example 1.

  In the light emitting device of Example 2, the phosphor 1 used in the light emitting device of Example 1 is used as the first phosphor, and as the second phosphor, the phosphor 3 used in the light emitting device of Example 1 is used. Also, phosphor 4 having a short emission peak wavelength and a narrow half-value width was used. In the light emitting device of Example 2, the use of the phosphor 4 has higher green color purity than the light emitting device of Example 1 using the phosphor 3. Therefore, it can be seen that the light emitting device of Example 2 has a higher NTSC ratio than the light emitting device of Example 1, and has a wider color reproduction range.

  In the light emitting device of Example 3, the phosphor 1 used in the light emitting device of Example 1 is used as the first phosphor, and the phosphor 4 used in the light emitting device of Example 2 is used as the second phosphor. Furthermore, phosphor 5 having a short emission peak wavelength and a narrow half-value width was used. In the light emitting device of Example 3, the use of the phosphor 5 makes the green color purity higher than that of the light emitting device of Example 2 using the phosphor 4. Therefore, it can be seen that the light emitting device of Example 3 has a higher NTSC ratio than the light emitting device of Example 2, and has a wider color reproduction range.

  In the light emitting device of Example 4, the phosphor 1 used in the light emitting device of Example 3 is used as the first phosphor, and as the second phosphor, from the phosphor 5 used in the light emitting device of Example 3. Although the emission peak wavelength is short, a phosphor 7 having a half width greater than that of the phosphor 5 is used. In the light emitting device of Example 4, the half width of the phosphor 7 used as the second phosphor is wider than that of the phosphor 5. Therefore, in the light emitting device of Example 4, the average emission intensity of the emission spectrum at 480 nm or more and 500 nm or less is larger than 7% when the maximum emission intensity of 440 nm or more and 460 nm or less is used as a reference, and the maximum emission intensity of 520 nm or more and 550 nm or less When the emission intensity is used as a reference, it is larger than 40%, and the color reproduction range is slightly narrower than that of the third embodiment, but is still a good color reproduction range.

  The light emitting device of Example 5 uses the phosphor 1 used in the light emitting device of Example 3 as the first phosphor, and the phosphor 5 used in the light emitting device of Example 3 as the second phosphor. Although the emission peak wavelength is short, the phosphor 8 having a half width greater than that of the phosphor 5 is used. In the light emitting device of Example 5, the half width of the phosphor 8 used as the second phosphor is wider than that of the phosphor 5. For this reason, in the light emitting device of Example 5, like the light emitting device of Example 4, the average emission intensity of the emission spectrum at 480 nm to 500 nm is larger than 7%, and the color reproduction range is slightly narrower than that of Example 3. However, the color reproduction range is still good.

  In the light emitting device of Example 6, the phosphor 1 used in the light emitting device of Example 3 is used as the first phosphor, and as the second phosphor, the phosphor 5 used in the light emitting device of Example 3 is used. Also, a phosphor 6 having a slightly longer emission peak wavelength and the same half width as the phosphor 5 is used. Therefore, the light emitting device of Example 6 has a high green color purity like the light emitting device of Example 3, and the color reproduction range is similar to that of Example 3.

  In contrast to the example described above, the light emitting device of Comparative Example 2 uses the phosphor 1 used in the light emitting device of Example 1 as the first phosphor, but has a half-value width wider than the phosphors 3 to 8. A broad phosphor 9 is used as the second phosphor. Therefore, in the light emitting device of Comparative Example 2, not only the green color purity is lowered, but the average light emission intensity of 590 nm to 610 nm is 10.8% when the maximum light emission intensity of 440 nm to 460 nm is used as a reference. 7.5%, and the maximum emission intensity of 520 nm or more and 550 nm or less is 53.4% and 33%, and the NTSC ratio is larger than those of Examples 1 to 5. It is falling.

  The light emitting device of the present disclosure can be suitably used for an LED display, a backlight light source, an illumination light source, and the like. Moreover, it can be used as a light-emitting device for backlights such as monitors and smartphones that are desired to reproduce RGB colors deeply and vividly.

  10: Light emitting element, 50: Fluorescent member, 71: First phosphor, 72: Second phosphor, 100: Light emitting device

Claims (8)

A light emitting device having an emission peak wavelength of 440 nm or more and 460 nm or less;
A first phosphor that emits fluorescence having an emission peak wavelength in a range of 640 nm or more and 670 nm or less, and represented by the following composition formula (I):
A second phosphor that emits fluorescence having an emission peak wavelength in the range of 520 nm or more and 550 nm or less,
When the maximum emission intensity in the range of 440 nm to 460 nm is 100%,
A light-emitting device having an emission spectrum whose average emission intensity in a range of 590 nm to 610 nm is 7.5% or less.
M ^a _x M ^b _y Al ₃ N _z : Eu (I)
(In the formula, M ^a is at least one element selected from the group consisting of Ca, Sr and Ba, and M ^b is at least one element selected from the group consisting of Li, Na and K. And x, y, and z satisfy 0.5 ≦ x ≦ 1.5, 0.5 ≦ y ≦ 1.2, and 3.5 ≦ z ≦ 4.5, respectively.   The light emitting device according to claim 1, wherein an average light emission intensity in a range of 480 nm to 500 nm is 7% or less. A light emitting device having an emission peak wavelength of 440 nm or more and 460 nm or less;
A first phosphor that emits fluorescence having an emission peak wavelength in a range of 640 nm or more and 670 nm or less, and represented by the following composition formula (I):
A second phosphor that emits fluorescence having an emission peak wavelength in the range of 520 nm or more and 550 nm or less,
When the maximum emission intensity in the range of 520 nm to 550 nm is 100%,
A light-emitting device having an emission spectrum whose average emission intensity in a range of 590 nm to 610 nm is 33% or less.
M ^a _x M ^b _y Al ₃ N _z : Eu (I)
(In the formula, M ^a is at least one element selected from the group consisting of Ca, Sr and Ba, and M ^b is at least one element selected from the group consisting of Li, Na and K. And x, y, and z satisfy 0.5 ≦ x ≦ 1.5, 0.5 ≦ y ≦ 1.2, and 3.5 ≦ z ≦ 4.5, respectively.   The light emitting device according to claim 3, wherein an average light emission intensity in a range of 480 nm to 500 nm is 40% or less.   The light emitting device according to any one of claims 1 to 4, wherein the second phosphor has a half-value width of an emission spectrum of 70 nm or less. The second phosphor is a β sialon phosphor represented by the following composition formula (IIa), a silicate phosphor represented by the following composition formula (IIb), and a halosilicate fluorescence represented by the following composition formula (IIc). The light-emitting device according to claim 1, wherein the light-emitting device is at least one selected from the group consisting of a thiogallate phosphor represented by the following formula (IId):
Si _6-w Al _w O _w N _8-w : Eu (IIa)
(In the formula, w satisfies 0 <w ≦ 4.2.)
(Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu (IIb),
(Ca, Sr, Ba) ₈ MgSi ₄ O ₁₆ (F, Cl, Br) ₂ : Eu (IIc)
(Ba, Sr, Ca) Ga ₂ S ₄ : Eu (IId) Wherein the first phosphor, ^{M a} in formula (I) comprises at least one element of Sr and Ca, ^{M b} is Li, is equal to or less than 53% reflectance at 460 nm, from claim 1 7. The light emitting device according to any one of 6.   8. The light according to claim 1, which emits light having an xy chromaticity coordinate specified by CIE 1931 in a range of x = 0.220 to 0.340 and y = 0.160 to 0.340. The light-emitting device of description.