JP7125631B2 - Light-emitting device and lamp equipped with the same - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to a light emitting device and a lamp having the same.

Light-emitting devices using light-emitting elements called light-emitting diodes (hereinafter also referred to as "LEDs") have attracted attention. For example, it is a light-emitting device that combines an LED that emits blue light and a phosphor that emits yellow light. This is a light-emitting device that emits white light by mixing blue light from a blue LED and yellow light emitted from a phosphor excited by the light.

A light-emitting device that combines a light-emitting element that emits blue light and a phosphor that emits yellow light has a high radiant intensity in the visible light region, and thus has high luminous efficiency. Furthermore, there are cases where a light-emitting device with a high general color rendering index, which is an index of how colors appear (color rendering properties) of an illuminated object, is required.

In accordance with JIS Z8726, the color rendering property evaluation procedure of a light source is the color difference ΔEi (i is from 1 to 15) when test colors (R1 to R15) having predetermined reflectance characteristics are measured with a test light source and a reference light source. Integer) is calculated by numerical calculation. Here, the upper limit of the color rendering index Ri (i is an integer from 1 to 15) is 100. That is, the smaller the color difference between the test light source and the corresponding reference light source of color temperature, the higher the color rendering evaluation value approaches 100.

In relation to the above, a light-emitting device using an LED that emits blue light and two types of phosphors that emit yellow to green light has been proposed, and is said to be able to achieve high color reproducibility (for example, patent References 1 and 2).

Japanese Patent Publication No. 2003-535477 Japanese Patent Publication No. 2003-535478

However, when trying to increase the general color rendering index Ra, the luminous efficiency of the light emitting device tends to decrease. In recent years, there is also a demand for light emitting devices using LEDs that not only have a general color rendering index Ra but also have a specific color rendering index, such as R15, and high luminous efficiency.

An object of one embodiment of the present disclosure is to provide a light-emitting device and a lamp having the same, which have a specific color rendering index and high luminous efficiency.

The present invention includes the following aspects.
A first aspect includes a light emitting element having an emission peak wavelength in the range of 430 nm or more and 470 nm or less, a first phosphor having a composition represented by the following formula (I), and a composition represented by the following formula (II) and at least one rare earth aluminate phosphor selected from the group consisting of a second phosphor having a composition represented by the following formula (III) and a third phosphor having a composition represented by the following formula: A light-emitting device comprising a fluorescent member including a fourth phosphor having a composition represented by (IV) and a fifth phosphor having a composition represented by formula (V) below.
_{Y3 (} Al,Ga) _5O12 :Ce(I)
_Lu3Al5O12 : _{Ce (} II)
_Y3Al5O12 : _Ce ( _III )
_A2 [M11 _{- pMn4} ^+pF6 _] (IV)
(Sr, Ca) _AlSiN3 :Eu(V)
(In formula (IV), A contains at least one selected from the group consisting of K, Li, Na, Rb, Cs and NH ₄ ⁺ , M1 is a Group 4 element, a Group 13 element and a Group 14 At least one element selected from the group consisting of group elements is included, and p indicates a number that satisfies 0<p<0.2.)

A second aspect is a lamp including the light emitting device.

According to one aspect of the present disclosure, it is possible to provide a light-emitting device capable of achieving excellent color rendering properties and high luminous efficiency, and a lamp including the same.

1 is a schematic cross-sectional view showing an example of a light emitting device according to the present invention; FIG. 3A and 3B are diagrams showing an emission spectrum of a light emitting device according to Example 1, an emission spectrum of a light emitting device according to Comparative Example 1, and a spectrum of a reference light source with a correlated color temperature of 6500K; FIG. 11 shows the emission spectrum of a light emitting device according to Example 2, the emission spectrum of a light emitting device according to Comparative Example 2, and the spectrum of a reference light source with a correlated color temperature of 5000K; 10A and 10B are diagrams showing an emission spectrum of a light emitting device according to Example 3, an emission spectrum of a light emitting device according to Comparative Example 3, and a spectrum of a reference light source with a correlated color temperature of 4000K; FIG. FIG. 10 shows the emission spectrum of a light emitting device according to Example 4, the emission spectrum of a light emitting device according to Comparative Example 4, and the spectrum of a reference light source with a correlated color temperature of 3500K; FIG. 11 shows the emission spectrum of a light emitting device according to Example 5, the emission spectrum of a light emitting device according to Comparative Example 5, and the spectrum of a reference light source with a correlated color temperature of 3000K. FIG. 11 shows the emission spectrum of a light emitting device according to Example 6, the emission spectrum of a light emitting device according to Comparative Example 6, and the spectrum of a reference light source with a correlated color temperature of 2700K.

Hereinafter, a light-emitting device according to the present disclosure and a lamp including the same will be described based on embodiments. However, the embodiments shown below are for embodying the technical idea of the present invention, and the present invention is not limited to the following. In this specification, the relationship between color names and chromaticity coordinates, the relationship between wavelength ranges of light and color names of monochromatic light, etc. conform to JIS Z8110. The content of each component in the composition means the total amount of the plurality of substances present in the composition unless otherwise specified when there are multiple substances corresponding to each component in the composition. The average particle size of the phosphor is a numerical value called Fisher Sub Sieve Sizer's No., which is measured using an air permeation method.

[Light emitting device]
The light-emitting device has a light-emitting element having an emission peak wavelength in the range of 430 nm or more and 470 nm or less, a first phosphor having a composition represented by the following formula (I), and a composition represented by the following formula (II). Two or more rare earth aluminate phosphors, including at least one selected from the group consisting of a second phosphor and a third phosphor having a composition represented by the following formula (III), and the following formula (IV ) and a fifth phosphor having a composition represented by the following formula (V).

_{Y3 (} Al,Ga) _5O12 :Ce(I)
_Lu3Al5O12 : _{Ce (} II)
_Y3Al5O12 : _Ce ( _III )
_A2 [M11 _{- pMn4} ^+pF6 _] (IV)
(Sr, Ca) _AlSiN3 :Eu(V)

In formula (IV), A contains at least one selected from the group consisting of K, Li, Na, Rb, Cs and NH ₄ ⁺ , and M1 is a group 4 element, a group 13 element and a group 14 It contains at least one element selected from the group consisting of elements. p indicates a number that satisfies 0<p<0.2.

In addition to the fourth phosphor and fifth phosphor emitting red light, a first phosphor, a second phosphor, and Two or more rare earth aluminate phosphors, including at least one selected from the group consisting of the third phosphor, are used in combination. As a result, it is possible to suppress the emission spectrum from bluish purple to blue in the range of 430 nm or more and 470 nm or less from becoming high intensity, and to greatly improve the emission intensity of the emission spectrum in the wavelength region from yellow to green emission. . In particular, only the emission spectrum in the blue-violet to blue wavelength region is suppressed to have a high intensity, and the emission spectrum in the yellow to green emission wavelength region is approximated by the reference light source, resulting in a green color with high luminosity. Since the luminous component of the emitted light can also be increased, it is possible to achieve excellent color rendering properties and high luminous efficiency.

In 1986, the CIE (International Commission on Illumination) published guidelines for color rendering that fluorescent lamps should possess. hereinafter referred to as "Ra") is 60 or more and less than 80 for factories that perform general work, and 80 or more and less than 90 for houses, hotels, restaurants, stores, offices, schools, hospitals, factories that perform precision work, etc. It is set to 90 or more in places where clinical examinations, art museums, etc., where color rendering properties are required.

Ra of the light-emitting device is, for example, 80 or higher, preferably 90 or higher, and more preferably 95 or higher. Note that the upper limit of Ra is 100. The special color rendering index is represented by the evaluation numbers from R9 to R15, where R9 is red, R10 is yellow, R11 is green, R12 is blue, R13 is the skin color of Westerners, R14 is the color of leaves, and R15 is the color of leaves. It is said to be the skin color of Japanese people. The higher the special color rendering index, the better. The upper limits of R9 to R15 are 100 each. R15 of the light-emitting device is preferably a higher numerical value, and particularly preferably 85 or more, 90 or more, 92 or more, or 93 or more.

The light emitted by the light-emitting device includes light from the light-emitting element and at least one rare earth aluminate phosphor selected from the group consisting of the first phosphor, the second phosphor, and the third phosphor. , the fourth phosphor, and the fifth phosphor. The light can be in the range of 20 to 0.50, and the light can be in the range of x=0.30 to 0.50 and y=0.30 to 0.45.
The correlated color temperature of light emitted by the light emitting device can be, for example, 2000K or higher, and can be 2500K or higher. Also, the correlated color temperature can be 8000K or less, and can be 7000K or less.

A light-emitting device 100, which is an example of a light-emitting device, will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing a light emitting device 100. FIG.
The light emitting device 100 emits light on the short wavelength side of visible light (for example, in the range of 380 nm or more and 485 nm or less), and has an emission peak wavelength in the range of 430 nm or more and 470 nm or less. and a molded body 40 on which the light emitting element 10 is mounted. The molded body 40 is formed by integrally molding the first lead 20, the second lead 30, and a resin portion 42 containing a thermoplastic resin or a thermosetting resin. The molded body 40 forms a recess having a bottom surface and a side surface, 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 via wires 60, respectively. The light emitting element 10 is covered with a fluorescent member 50 . The fluorescent member 50 includes, for example, at least one selected from the group consisting of a first fluorescent substance, a second fluorescent substance, and a third fluorescent substance as a fluorescent substance 70 that converts the wavelength of light from the light emitting element 10. It contains rare earth aluminate phosphors 71 and 72, a fourth phosphor 73 and a fifth phosphor 74, and a resin.

The fluorescent member 50 not only converts the wavelength of the light emitted by the light emitting element 10, but also functions as a member for protecting the light emitting element 10 from the external environment. In FIG. 1, the phosphors 70 are unevenly distributed in the phosphor member 50 . By arranging the phosphor 70 close to the light emitting element 10 in this way, the wavelength of the light from the light emitting element 10 can be efficiently converted, and a light emitting device with excellent luminous efficiency can be obtained. In addition, the arrangement of the fluorescent member 50 including the fluorescent substance 70 and the light emitting element 10 is not limited to a form in which they are arranged close to each other. The light-emitting element 10 and the phosphor 70 can be arranged in the space 50 . Further, by mixing the phosphor 70 in the entire fluorescent member 50 at a substantially uniform ratio, it is possible to obtain light with more suppressed color unevenness.

(light emitting element)
The emission peak wavelength of the light emitting element is in the range of 430 nm or more and 470 nm or less, preferably in the range of 440 nm or more and 465 nm or less, and in the range of 445 nm or more and 460 nm or less from the viewpoint of luminous efficiency and color rendering properties. is more preferable, and may be in the range of 450 nm or more and 460 nm or less. Using such a light-emitting element as an excitation light source, a light-emitting device that emits mixed-color light of light from the light-emitting element and fluorescence from the phosphor is configured.

The half width of the emission spectrum of the light emitting element may be, for example, 30 nm or less.
It is preferable to use a semiconductor light-emitting element such as an LED 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 resistance to mechanical impact.
As the semiconductor light emitting device, for example, a nitride semiconductor (In _X Al _Y Ga _1-XY N, where X and Y satisfy 0≦X, 0≦Y, and X+Y≦1) is used. A semiconductor light-emitting element that emits blue light or the like can be used.
As used herein, the half width refers to the full width at half maximum of an emission peak in an emission spectrum, and refers to the wavelength width of an emission peak that is 50% of the maximum value of the emission peak in the emission spectrum.

(Phosphor)
The light-emitting device absorbs part of the light emitted from the light-emitting element, and includes a first phosphor having a composition represented by formula (I) above and a second phosphor having a composition represented by formula (II) above. and two or more rare earth aluminate phosphors, including at least one selected from the group consisting of a third phosphor having a composition represented by the formula (III), and a phosphor represented by the formula (IV) and a fifth phosphor having a composition represented by formula (V) above. The first phosphor, the second phosphor, the third phosphor, the fourth phosphor, and the fifth phosphor each have specific compositions represented by the above formulas. Two or more rare earth aluminate phosphors, a fourth phosphor, and a fifth phosphor, including at least one selected from the group consisting of the first phosphor, the second phosphor, and the third phosphor contained in the fluorescent member While increasing the luminous flux of the light emitting device by appropriately selecting the composition ratio of each phosphor of the phosphor, the color rendering property is set to a desired range, for example, the general color rendering index Ra of the light emitting device is 90 or more, and the special color rendering index R15. 85 or more.

The content of the fourth phosphor relative to the total content of the rare earth aluminate phosphors may be selected according to the correlated color temperature desired for the light emitting device. For example, in the case of a light emitting device that emits light with a correlated color temperature in the range of 4750 K or more and 7000 K or less, the content ratio of the fourth phosphor with respect to the total content of the rare earth aluminate phosphor is, from the viewpoint of luminous flux and color rendering properties , preferably in the range of 0.35 to 0.7, more preferably in the range of 0.4 to 0.65. In the case of a light emitting device that emits light with a correlated color temperature in the range of 2500 K or more and 4750 K or less, the content ratio of the fourth phosphor with respect to the total content of the rare earth aluminate phosphor is 0 from the viewpoint of luminous flux and color rendering properties. .7 or more and 1.3 or less, and more preferably 0.75 or more and 1.2 or less.

The content ratio of the fourth phosphor to the total content of the rare earth aluminate phosphor, the fourth phosphor, and the fifth phosphor (hereinafter sometimes referred to as the "total phosphor content") is It may be selected according to the desired correlated color temperature. For example, in the case of a light emitting device that emits light with a correlated color temperature in the range of 4750 K or more and 7000 K or less, the content rate of the fourth phosphor with respect to the total phosphor content is 0.25 or more from the viewpoint of luminous flux and color rendering properties. It is preferably within the range of 0.45 or less, and more preferably within the range of 0.27 or more and 0.4 or less. In the case of a light emitting device that emits light with a correlated color temperature in the range of 2500K or more and 4750K or less, the content ratio of the fourth phosphor with respect to the total phosphor content is 0.4 or more and 0.4 or more from the viewpoint of luminous flux and color rendering properties. It is preferably in the range of 6 or less, and more preferably in the range of 0.4 to 0.55.

The content ratio of the total rare earth aluminate phosphor content to the total phosphor content may be selected according to the correlated color temperature desired for the light emitting device. For example, in the case of a light emitting device that emits light with a correlated color temperature in the range of 4750 K or more and 7000 K or less, the content ratio of the total content of the rare earth aluminate phosphor to the total content of the phosphor is from the viewpoint of luminous flux and color rendering properties. Therefore, it is preferably in the range of 0.5 to 0.75, more preferably in the range of 0.55 to 0.7. In the case of a light emitting device that emits light with a correlated color temperature in the range of 2500 K or more and 4750 K or less, the content ratio of the total content of the rare earth aluminate phosphor to the total content of the phosphor is, from the viewpoint of luminous flux and color rendering properties, It is preferably within the range of 0.4 or more and 0.6 or less, and more preferably within the range of 0.4 or more and 0.55 or less.

Containment of the total content of the fourth phosphor and the fifth phosphor (hereinafter, the fourth phosphor and the fifth phosphor may be collectively referred to as "red-emitting phosphor") relative to the total phosphor content The ratio may be selected according to the correlated color temperature that the light emitting device is intended for. For example, in the case of a light-emitting device that emits light with a correlated color temperature in the range of 4750K or more and 7000K or less, it is preferably in the range of 0.25 or more and 0.5 or less from the viewpoint of luminous flux and color rendering properties. It is more preferably within the range of 3 or more and 0.45 or less. In the case of a light-emitting device that emits light with a correlated color temperature in the range of 2500K or more and 4750K or less, the content ratio of the red light-emitting phosphor with respect to the total phosphor content is 0.4 or more and 0.4 or more from the viewpoint of luminous flux and color rendering properties. It is preferably within the range of 6 or less, and more preferably within the range of 0.45 or more and 0.55 or less.

Rare earth aluminate phosphor The rare earth aluminate phosphor contains at least one selected from the following first phosphor, second phosphor and third phosphor, and contains two or more phosphors. .
The first phosphor is a trivalent cerium-activated phosphor having a composition represented by the following formula (I).
_{Y3 (} Al,Ga) _5O12 :Ce(I)
The emission peak wavelength of the first phosphor is preferably in the range of 520 nm or more and 550 nm or less. The half width of the first phosphor is preferably in the range of 95 nm or more and 120 nm or less.
The second phosphor is a trivalent cerium-activated phosphor having a composition represented by the following formula (II).
_Lu3Al5O12 : _{Ce (} II)
The emission peak wavelength of the second phosphor is preferably in the range of 500 nm or more and 545 nm or less. The half width of the second phosphor is preferably in the range of 95 nm or more and 105 nm or less.
The third phosphor is a trivalent cerium-activated phosphor having a composition represented by the following formula (III).
_Y3Al5O12 : _Ce ( _III )
The emission peak wavelength of the third phosphor is preferably in the range of 535 nm or more and 555 nm or less. The half width of the third phosphor is preferably in the range of 100 nm or more and 120 nm or less.

The maximum excitation wavelength of the rare earth aluminate phosphor is preferably in the range of 220 nm or more and 490 nm or less, more preferably in the range of 430 nm or more and 470 nm or less, and 440 nm or more and 460 nm or less, in consideration of luminous efficiency. is more preferably within the range of

The average particle diameter of the rare earth aluminate phosphor is, for example, in the range of 5 μm or more and 30 μm or less, and in the range of 20 μm or more and 25 μm or less, in consideration of the improvement of luminous intensity and workability in the manufacturing process of the light emitting device. is preferred.

Fourth Phosphor The fourth phosphor is a fluoride phosphor that has a composition represented by the following formula (IV), is activated by tetravalent manganese, and emits red light. The fourth phosphor preferably has an emission peak wavelength within the range of 610 nm or more and 650 nm or less.
_A2 [M11 _{- pMn4} ^+pF6 _] (IV)
However, in the above formula (IV), A contains at least one element selected from the group consisting of K, Li, Na, Rb, Cs and NH ₄ ⁺ , A is preferably K, M1 contains at least one element selected from the group consisting of Group 4 elements, Group 13 elements and Group 14 elements. M1 preferably contains at least one element selected from the group consisting of silicon, aluminum, germanium and titanium, more preferably at least one element selected from the group consisting of silicon and aluminum. p indicates a number that satisfies 0<p<0.2.

The half width of the emission spectrum of the fourth phosphor is preferably small, for example 10 nm or less. The maximum excitation wavelength of the fourth phosphor is preferably in the range of 430 nm or more and 470 nm or less, and more preferably in the range of 440 nm or more and 460 nm or less, in consideration of luminous efficiency.

The average particle diameter of the fourth phosphor may be, for example, in the range of 5 μm or more and 50 μm or less, and may be in the range of 10 μm or more and 30 μm or less, in consideration of the improvement of the light emission intensity and workability in the manufacturing process of the light emitting device. preferable.
The light-emitting device may contain a single fourth phosphor or a combination of two or more fourth phosphors having different compositions.

Fifth Phosphor The fifth phosphor is a nitride phosphor that emits red light and is activated by divalent europium having a composition represented by the following formula (V).
(Sr, Ca) _AlSiN3 :Eu(V)
The fifth phosphor contains at least one selected from the group consisting of Sr and Ca, and preferably contains both Sr and Ca. It is more preferable to have

The emission peak wavelength of the fifth phosphor is preferably 600 nm or longer, more preferably 615 nm or longer. The emission peak wavelength of the fifth phosphor is preferably 630 nm or less, more preferably 620 nm or less. The emission peak wavelength of the fifth phosphor may be selected from the viewpoint of luminous flux and color rendering properties according to the correlated color temperature intended for the light emitting device. For example, when the light emitting device emits light with a correlated color temperature in the range of 3250K to 7000K, the emission peak wavelength of the fifth phosphor is preferably in the range of 600 nm to 620 nm. When the light emitting device emits light with a correlated color temperature of 2500 K or more and 3250 K or less, the emission peak wavelength of the fifth phosphor is preferably in the range of 615 nm or more and 630 nm or less.

The half width of the emission spectrum of the fifth phosphor is, for example, 100 nm or less, preferably 80 nm or less, from the viewpoint of luminous flux and color rendering properties. The maximum excitation wavelength of the fifth phosphor is preferably in the range of 220 nm or more and 490 nm or less, more preferably in the range of 430 nm or more and 470 nm or less, in consideration of luminous efficiency, and 440 nm or more and 460 nm or less. more preferably within.

The average particle size of the fifth phosphor is, for example, in the range of 5 μm or more and 30 μm or less, and in the range of 10 μm or more and 20 μm or less, in consideration of the improvement of the workability in the light emission intensity and the manufacturing process of the light emitting device. preferable.
The light-emitting device may contain one type of the fifth phosphor, or a combination of two or more types of fifth phosphors having different compositions.

Emission Spectrum of Light-Emitting Device The emission spectrum of the light-emitting device including the fluorescent member containing the phosphor described above is represented by a spectral distribution having the wavelength on the horizontal axis and the emission intensity on the vertical axis. In the emission spectrum of the light-emitting device, the emission peak intensity ratio of the emission peak of the fourth phosphor to the emission peak of the light-emitting element may be selected according to the correlated color temperature intended for the light-emitting device. For example, when the correlated color temperature is a light emitting device that emits light within the range of 4750 K or more and 7000 K or less, the emission peak intensity ratio of the emission peak of the fourth phosphor to the emission peak of the light emitting element is, from the viewpoint of luminous flux and color rendering properties , preferably in the range of 1.0 to 2.0, more preferably in the range of 1.1 to 1.9. In the case of a light emitting device that emits light with a correlated color temperature in the range of 3750 K or more and 4750 K or less, the emission peak intensity ratio of the emission peak of the fourth phosphor to the emission peak of the light emitting element is 2 from the viewpoint of luminous flux and color rendering properties. .0 or more and 3.5 or less, and more preferably 2.5 or more and 3.0 or less. In the case of a light emitting device that emits light with a correlated color temperature in the range of 2850 K or more and 3750 K or less, the emission peak intensity ratio of the emission peak of the fourth phosphor to the emission peak of the light emitting element is 3 from the viewpoint of luminous flux and color rendering properties. 0.5 or more and 5.5 or less, and more preferably 4.0 or more and 5.2 or less. In the case of a light emitting device that emits light with a correlated color temperature in the range of 2500 K or more and 2850 K or less, the emission peak intensity ratio of the emission peak of the fourth phosphor to the emission peak of the light emitting element is 5 from the viewpoint of luminous flux and color rendering properties. 0.5 or more and 7.0 or less, and more preferably 6.0 or more and 6.5 or less.

Other Phosphors The light-emitting device may contain phosphors other than the first to fifth phosphors, if necessary. Other phosphors include (Sr, Ba, Ca) ₁₀ (PO ₄ ) ₆ (Br, Cl) ₂ :Eu, (Y, Gd, Tb, Lu) ₃ (Al, Ga) ₅ O ₁₂ :Ce( However, except for the composition of the _first to _third phosphors.), _Ca3Sc2Si3O12 :Ce, _CaSc2O4 :Ce, ₍ La _, Y) _3Si6N11 : _Ce , ( _Ca , Sr,Ba) _3Si6O9N4 :Eu, ₍ Ca _, Sr, _Ba ) _3Si6O12N2 : _Eu , ₍ Ba, _Sr ,Ca) _Si2O2N2 : _Eu , ₍ Ca, Sr,Ba) _2Si5N8 :Eu, ₍ Ca,Sr,Ba)S: _Eu , ₍ Ba,Sr,Ca) _Ga2S4 :Eu and the like. When the light-emitting device contains other phosphors, the content thereof is appropriately adjusted so as to obtain specific light-emitting properties.

In addition to using a commercially available phosphor as the phosphor, for example, the fourth phosphor is the applicant's previously filed Japanese Patent Application No. 2014-202266, Japanese Patent Application No. 2020-212532. can be manufactured. Further, other phosphors can be produced, for example, as follows. Elements, oxides, carbonates, nitrides, chlorides, fluorides, sulfides, and the like of the elements contained in the composition of the phosphor are used as raw materials, and these raw materials are weighed so as to obtain a predetermined composition ratio. Further, additive materials such as flux are added to the raw materials as appropriate, and the mixture is wet- or dry-mixed using a mixer. This makes it possible to promote the solid phase reaction and form particles of uniform size. Further, as the mixer, in addition to the ball mill that is usually used industrially, a pulverizer such as a vibration mill, a roll mill, and a jet mill may be used. The specific surface area can be increased by pulverizing with a pulverizer. In addition, in order to keep the specific surface area of the obtained phosphor particles within a certain range, a settling tank, a hydrocyclone, a wet separator such as a centrifugal separator, and a dry classifier such as a cyclone and air separator, which are commonly used industrially, can be used. can also be used for classification. The above 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 a reducing atmosphere containing hydrogen. Firing is performed at a predetermined temperature and time. The calcined material is pulverized, dispersed, filtered, etc. to obtain the target phosphor powder. Solid-liquid separation can be carried out by a method commonly used industrially, such as filtration, suction filtration, pressure filtration, centrifugation, decantation, and the like. Drying can be carried out by means of equipment commonly used industrially, such as vacuum dryers, hot air dryers, conical dryers and rotary evaporators.

Fluorescent Member The light-emitting device includes, for example, a fluorescent member that contains a phosphor and a resin and covers the light-emitting element. Thermoplastic resins and thermosetting resins are examples of resins that constitute the fluorescent member. Specific examples of thermosetting resins include epoxy resins, silicone resins, and modified silicone resins such as epoxy-modified silicone resins.

The fluorescent member may optionally contain other components in addition to the fluorescent material and resin. Other components include fillers such as silica, barium titanate, titanium oxide and aluminum oxide, light stabilizers, colorants and the like. When the fluorescent member contains other components, the content is not particularly limited and can be appropriately selected according to the purpose. For example, when a filler is included as another component, its content can be 0.01 to 20% by mass with respect to the resin.

[Light fixture]
The lamp may include at least one of the light emitting devices described above. Furthermore, the lamp may be equipped with a combination of at least one of the light emitting devices described above and a known light emitting device that emits mixed white light. In addition to the light emitting device described above, the lamp may further include a reflecting member, a protective member, an accessory device for supplying power to the light emitting device, and the like. Note that the lamp may include a plurality of the light emitting devices described above. When the lamp has a plurality of light emitting devices, it may have a plurality of identical light emitting devices, or may have a plurality of light emitting devices with different correlated color temperatures, for example. Further, a driving device may be provided that can individually drive a plurality of light emitting devices to adjust brightness and correlated color temperature according to preference. The lighting fixture may be used in any of a direct mounting type, an embedded type, a hanging type, and the like.

Examples of the present invention will be specifically described below.

(Phosphor)
Prior to manufacturing the light-emitting device, the following phosphors were prepared as phosphors used in Examples and Comparative Examples.
_{Y3 (} Al,Ga) _5O12 :Ce(I)
_Lu3Al5O12 : _{Ce (} II)
_Y3Al5O12 : _Ce ( _III )
_A2 [M11 _{- pMn4} ^+pF6 _] (IV)
(In formula (IV) above, A is K, M1 is Si, and p is a number satisfying 0<p<0.2.)
(Sr, Ca) _AlSiN3 :Eu(V)
As the first phosphor, a rare earth aluminate phosphor (hereinafter also referred to as "GYAG1") having a composition represented by formula (I), an emission peak wavelength of 545 nm, and a half width of 104.0 nm ) and a rare earth aluminate phosphor (hereinafter also referred to as “GYAG2”) having a composition represented by formula (I) and having an emission peak wavelength of 533 nm and a half width of 107.0 nm. Got ready.
As the second phosphor, a rare earth aluminate phosphor (hereinafter also referred to as “LAG”) having a composition represented by formula (II), an emission peak wavelength of 533 nm, and a half width of 100.5 nm. ) was prepared.
As the third phosphor, a rare earth aluminate phosphor (hereinafter also referred to as “YAG”) having a composition represented by formula (III), an emission peak wavelength of 545 nm, and a half width of 109.5 nm. ) was prepared.
As the fourth phosphor, a red-emitting fluoride phosphor (hereinafter also referred to as “KSF”) having a composition represented by formula (IV), an emission peak wavelength of 630 nm, and a half width of 14 nm. prepared.
As the fifth phosphor, a red-emitting nitride phosphor having a composition represented by formula (V), an emission peak wavelength in the range of 600 nm or more and 630 nm or less, and a half width of 80 nm (hereinafter referred to as " SCASN”) was prepared.
Further, a chlorosilicate phosphor having a composition represented by the following formula (VI), an emission peak wavelength of 521 nm, and a half width of 63 nm was prepared as a phosphor used in the light emitting device of the comparative example.
_{Ca8MgSi4O16Cl12 : Eu (} VI)
The emission peak wavelength, half width, etc. of each phosphor described above can be adjusted by changing the manufacturing conditions and composition of the phosphor.

A gallium nitride-based semiconductor light-emitting device having an emission peak wavelength of 450 nm was prepared as the light-emitting device.

(Example 1)
Fabrication of light-emitting device A blue light-emitting LED (light-emitting element) having an emission peak wavelength of 450 nm, a first phosphor GYAG1 as a rare earth aluminate phosphor, a second phosphor LAG, a fourth phosphor KSF, A light-emitting device was fabricated by combining SCASN, which is the fifth phosphor.
The content of each phosphor is adjusted to the value shown in Table 1 below so that the correlated color temperature is around 6500K, and the blended phosphor is added to the silicone resin, mixed and dispersed, and then removed. A phosphor-containing resin composition was obtained by foaming. Next, this phosphor-containing resin composition was injected and filled on the light emitting element, and further heated to cure the resin composition. A light-emitting device was manufactured through such steps.

(Examples 2 to 6)
a combination of two or more rare earth aluminate phosphors, a fourth phosphor and a fifth phosphor, including at least one selected from the group consisting of a first phosphor, a second phosphor and a third phosphor; , in the same manner as in Example 1 except that the content ratio of each phosphor was changed to the value shown in Table 1 below, and the correlated color temperature was adjusted from 2700K to around 5000K in Examples 2 to 6. was fabricated.

For the light emitting devices according to Examples 1 to 6, the chromaticity coordinates of the emitted color, the correlated color temperature (Tcp; K), the general color rendering index (Ra (R1 to R8)), and the special color rendering index (R9 to R15) were measured. It was measured. Specifically, for each light-emitting device used in Examples and Comparative Examples, a light measurement system combining a spectrophotometer (PMA-12, Hamamatsu Photonics Co., Ltd.) and an integrating sphere was used to measure the color of the CIE 1931 chromaticity diagram. Chromaticity coordinates (x, y), luminous flux, and radiant flux (spectral total radiant flux) in the degree coordinate system were obtained. Table 1 also shows the results of the chromaticity coordinates of the emitted light and the correlated color temperature (Tcp; K). The color rendering index results are shown in Table 2 below.
The emission spectrum of each light-emitting device of Examples and Comparative Examples described later was measured using a spectrofluorophotometer. Table 1 also shows the emission peak intensity ratio of the emission peak of the fourth phosphor to the emission peak of the light emitting element. 2 to 7 show the emission spectrum of each light emitting device of Examples 1 to 6 and the spectrum of the reference light source.

(Comparative example 1)
As phosphors, a chlorosilicate phosphor that does not use a fourth phosphor, has a composition represented by formula (VI), and has an emission peak wavelength of 521 nm, a first phosphor GYAG2, and a fifth phosphor SCASN A light emitting device having a correlated color temperature of 6500 K was produced in the same manner as in Example 1 except that the content ratio of each phosphor was set to the value shown in Table 3 below. did.

(Comparative Examples 2 to 6)
In the same manner as in Comparative Example 1 except that the amount of the phosphor was changed so that the content ratio of each phosphor was the value shown in Table 3 below, comparison was performed so that the correlated color temperature was from 2700K to around 5000K. Light emitting devices of Examples 2 to 6 were fabricated.

For each light emitting device according to Comparative Examples 1 to 6, the chromaticity coordinates of each light emitting device were measured in the same manner as the light emitting device according to the example, and the results are shown in Table 3, and the results of the color rendering index are shown in Table 4 below. shown in

As shown in Tables 2 and 4, when comparing the Ra and R15 of the light emitting devices of Examples and Comparative Examples having substantially the same correlated color temperature, Ra values of Examples and Comparative Examples are substantially the same. Got. On the other hand, with respect to R15, the light emitting devices of the examples have higher values than the comparative examples at each correlated color temperature, and the light emitting devices of the examples have a specific color rendering index compared to the light emitting device of the comparative examples. It can be seen that the color rendering property is higher than Further, the relative luminous flux of each light-emitting device of the example is compared with the light-emitting device of the example and the light-emitting device of the comparative example having substantially the same correlated color temperature. 108.6% of the light emitting device of Example 2, 111.2% of the light emitting device of Example 3, 115.5% of the light emitting device of Example 3, 117.7% of the light emitting device of Example 4, and 117.7% of the light emitting device of Example 5 114.0% for the device and 111.8% for Example 6. A high luminous flux was obtained in the light emitting device of any of the examples.
From the above, it can be seen that the light emitting device according to the example has high luminous flux and color rendering properties.

2 to 7 show the emission spectrum of each light emitting device according to Examples 1 to 6 and Comparative Examples 1 to 6 and the spectrum of the reference light source for each correlated color temperature. Each of the light emitting devices according to Examples 1 to 6 emitted light with correlated color temperatures close to the correlated color temperatures of 6500K, 5000K, 4000K, 3500K, 3000K, and 2700K, respectively. Each of the light-emitting devices of Examples 1 to 3, which emits light with correlated color temperatures close to 6500 K, 5000 K, and 4000 K, was adjusted so that the emission spectrum from bluish purple to blue in the range of 430 nm or more and 470 nm or less did not have a high intensity. It was possible to suppress and approximate the emission spectrum of the reference light source. Each of the light-emitting devices of Examples 4 to 6, which emit light with correlated color temperatures close to 3500 K, 3000 K, and 2700 K, suppresses the emission spectrum from bluish purple to blue to have a high intensity, and suppresses the emission spectrum from yellow to green. According to the wavelength region, JIS Z8110, the emission spectrum in the wavelength range from 495 nm to 584 nm was closer to the reference light source without increasing the intensity of the emission spectrum of the reference light source.

The light-emitting device of the present disclosure can be used for lighting fixtures, LED displays, camera flashlights, and the like, which have excellent light-emitting properties. In particular, it can be suitably used for lighting devices and light sources that require high luminous flux and color rendering properties. Furthermore, it can be used as a lamp equipped with this light emitting device.

10: Light-emitting element, 50: Fluorescent member, 70: Phosphor, 71, 72: First to third phosphors, 73: Fourth phosphor, 74: Fifth phosphor, 100: Light-emitting device.

Claims (12)

a light-emitting element having an emission peak wavelength in the range of 430 nm or more and 470 nm or less;
A first phosphor having a composition represented by the following formula (I), a second phosphor having a composition represented by the following formula (II), and a third phosphor having a composition represented by the following formula (III) a fourth phosphor having a composition represented by the following formula (IV), and a composition represented by the following formula (V): and a fluorescent member containing a fifth phosphor , wherein the content ratio of the fourth phosphor with respect to the total content of the rare earth aluminate phosphor is in the range of 0.35 or more and 0.7 or less, A light-emitting device that emits light with a correlated color temperature in the range of 4750K to 7000K .
_{Y3 (} Al,Ga) _5O12 :Ce(I)
_Lu3Al5O12 : _{Ce (} II)
_Y3Al5O12 : _Ce ( _III )
_A2 [M11 _{- pMn4} ^+pF6 _] (IV)
(Sr, Ca) _AlSiN3 :Eu(V)
(In the formula (IV), A contains at least one selected from the group consisting of K, Li, Na, Rb, Cs and NH ₄ ⁺ , M1 is a Group 4 element, a Group 13 element and It contains at least one element selected from the group consisting of Group 14 elements, and p represents a number that satisfies 0<p<0.2.) a light-emitting element having an emission peak wavelength in the range of 430 nm or more and 470 nm or less;
A first phosphor having a composition represented by the following formula (I), a second phosphor having a composition represented by the following formula (II), and a third phosphor having a composition represented by the following formula (III) a fourth phosphor having a composition represented by the following formula (IV), and a composition represented by the following formula (V): and a phosphor member containing a fifth phosphor, wherein the content ratio of the fourth phosphor with respect to the total content of the rare earth aluminate phosphor, the fourth phosphor and the fifth phosphor is 0.5. A light-emitting device that emits light having a correlated color temperature in the range of 25 to 0.45 and in the range of 4750K to 7000K.
Y3 ₍ Al,Ga) _5O12 : _Ce ( I)
Lu3Al5O12 : Ce _{( II} ) _{_}
Y3Al5O12 _: Ce _{( III} ) _
A2 [M11 _{- pMn4 +} ^pF6 ] ( IV ₎
(Sr _, Ca)AlSiN3 :Eu(V)
(In the formula (IV), A contains at least one selected from the group consisting of K, Li, Na, Rb, Cs and NH ₄ ⁺ , M1 is a Group 4 element, a Group 13 element and It contains at least one element selected from the group consisting of Group 14 elements, and p represents a number that satisfies 0<p<0.2.) a light-emitting element having an emission peak wavelength in the range of 430 nm or more and 470 nm or less;
A first phosphor having a composition represented by the following formula (I), a second phosphor having a composition represented by the following formula (II), and a third phosphor having a composition represented by the following formula (III) a fourth phosphor having a composition represented by the following formula (IV), and a composition represented by the following formula (V): and a phosphor member containing a fifth phosphor , wherein the total content of the rare earth aluminate phosphor with respect to the total content of the rare earth aluminate phosphor, the fourth phosphor, and the fifth phosphor is within the range of 0.5 to 0.75 and the correlated color temperature is within the range of 4750K to 7000K.
Y3 ₍ Al,Ga) _5O12 : _Ce ( I)
Lu3Al5O12 : Ce _{( II} ) _{_}
Y3Al5O12 _: Ce _{( III} ) _
A2 [M11 _{- pMn4 +} ^pF6 ] ( IV ₎
(Sr _, Ca)AlSiN3 :Eu(V)
(In the formula (IV), A contains at least one selected from the group consisting of K, Li, Na, Rb, Cs and NH ₄ ⁺ , M1 is a Group 4 element, a Group 13 element and It contains at least one element selected from the group consisting of Group 14 elements, and p represents a number that satisfies 0<p<0.2.) a light-emitting element having an emission peak wavelength in the range of 430 nm or more and 470 nm or less;
A first phosphor having a composition represented by the following formula (I), a second phosphor having a composition represented by the following formula (II), and a third phosphor having a composition represented by the following formula (III) a fourth phosphor having a composition represented by the following formula (IV), and a composition represented by the following formula (V): and a phosphor member containing a fifth phosphor , wherein the fourth phosphor and the fifth phosphor with respect to the total content of the rare earth aluminate phosphor, the fourth phosphor and the fifth phosphor is in the range of 0.25 to 0.5 and the correlated color temperature is in the range of 4750K to 7000K.
Y3 ₍ Al,Ga) _5O12 : _Ce ( I)
Lu3Al5O12 : Ce _{( II} ) _{_}
Y3Al5O12 _: Ce _{( III} ) _
A2 [M11 _{- pMn4 +} ^pF6 ] ( IV ₎
(Sr _, Ca)AlSiN3 :Eu(V)
(In the formula (IV), A contains at least one selected from the group consisting of K, Li, Na, Rb, Cs and NH ₄ ⁺ , M1 is a Group 4 element, a Group 13 element and It contains at least one element selected from the group consisting of Group 14 elements, and p represents a number that satisfies 0<p<0.2.) a light-emitting element having an emission peak wavelength in the range of 430 nm or more and 470 nm or less;
A first phosphor having a composition represented by the following formula (I), a second phosphor having a composition represented by the following formula (II), and a third phosphor having a composition represented by the following formula (III) a fourth phosphor having a composition represented by the following formula (IV), and a composition represented by the following formula (V): and a fluorescent member containing a fifth phosphor, wherein the emission peak intensity ratio of the emission peak of the fourth phosphor to the emission peak of the light emitting element in the emission spectrum is in the range of 1.0 or more and 2.0 or less. A light-emitting device that emits light with a correlated color temperature within the range of 4750K or more and 7000K or less.
Y3 ₍ Al,Ga) _5O12 : _Ce ( I)
Lu3Al5O12 : Ce _{( II} ) _{_}
Y3Al5O12 _: Ce _{( III} ) _
A2 [M11 _{- pMn4 +} ^pF6 ] ( IV ₎
(Sr _, Ca)AlSiN3 :Eu(V)
(In the formula (IV), A contains at least one selected from the group consisting of K, Li, Na, Rb, Cs and NH ₄ ⁺ , M1 is a Group 4 element, a Group 13 element and It contains at least one element selected from the group consisting of Group 14 elements, and p represents a number that satisfies 0<p<0.2.) 6. The light emitting device according to any one of claims 1 to 5, wherein the light emitting element has an emission peak wavelength within a range of 440 nm or more and 460 nm or less. The light emitting device according to any one of claims 1 to 6, wherein the first phosphor has an emission peak wavelength in the range of 520 nm or more and 550 nm or less, and a half width in the range of 95 nm or more and 120 nm or less. The light emitting device according to any one of claims 1 to 7, wherein the second phosphor has an emission peak wavelength in the range of 500 nm or more and 545 nm or less, and a half width in the range of 95 nm or more and 105 nm or less. The light emitting device according to any one of claims 1 to 8, wherein the third phosphor has an emission peak wavelength in the range of 535 nm or more and 555 nm or less, and a half width in the range of 100 nm or more and 120 nm or less. The light emitting device according to any one of claims 1 to 9, wherein the fifth phosphor has an emission peak wavelength in the range of 600 nm or more and 630 nm or less, and has a half width of 80 nm or less. 11. The light emitting device according to claim 1, wherein the general color rendering index Ra is 90 or more, or the special color rendering index R15 is 85 or more. A lamp comprising the light emitting device according to any one of claims 1 to 11 .

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