JP2021006909A - Light-emitting device - Google Patents

Abstract

To provide a light-emitting device having excellent color rendering properties.SOLUTION: A light-emitting device comprises a light-emitting element having an emission peak wavelength in a range of 410 nm to 440 nm inclusive, and a fluorescent member. The fluorescent member includes as a fluorescent substance: a first fluorescent substance having an emission peak wavelength in 430 nm to 500 nm inclusive with a half-width of 29 nm to 49 nm inclusive; a second fluorescent substance having an emission peak wavelength in 440 nm to 550 nm inclusive with a half-width of 58 nm to 78 nm inclusive or 50 nm to 75 nm inclusive; a third fluorescent substance having an emission peak wavelength in 500 nm to 600 nm inclusive with a half-width of 95 nm to 115 nm inclusive; a fourth fluorescent substance having an emission peak wavelength in 610 nm to 650 nm inclusive with a half-width of 80 nm to 100 nm inclusive; and a fifth fluorescent substance having an emission peak wavelength in 650 nm to 670 nm inclusive with a half-width of 45 nm or less.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a light emitting device.

As a light emitting device that emits white light using a light emitting diode (hereinafter, also referred to as "LED"), for example, there is a light emitting device that combines an LED that emits blue light and a phosphor that emits yellow light. This light emitting device emits white light by mixing the blue light of the LED and the yellow light of the phosphor excited by the light. In such a light emitting device, the radiation intensity in the visible light region is strong and the luminous efficiency is high, but the radiation intensity in the blue-green region and the red region may not be sufficiently obtained. Therefore, there is room for further improvement in the appearance of the color of the irradiated object (hereinafter referred to as "color rendering property").

Here, the procedure for evaluating the color playability of the light source is that the color difference ΔEi (i) when the test colors (R1 to R15) having a predetermined reflectance characteristic are measured by the test light source and the reference light source by JIS Z8726, respectively. It is stipulated that the number of color reproduction evaluations is calculated by numerically calculating (an integer from 1 to 15). 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 reference light source of the corresponding color temperature, the higher the color rendering index approaches 100. Of the color rendering index, the average value of R1 to R8 is called the average color rendering index (hereinafter, also referred to as Ra), and R9 to R15 are called the special color rendering index. Regarding the special color rendering index, R9 is red, R10 is yellow, R11 is green, R12 is blue, R13 is Western skin color, R14 is leaf color, and R15 is Japanese skin color.

In order to enhance the color rendering properties of the light source, a light emitting device using an LED that emits blue light and two types of phosphors that emit light from green to yellow, for example, a chlorosilicate phosphor and a Y or Tb garnet phosphor, has been proposed. (See, for example, Patent Document 1). Further, in order to further enhance the color rendering property, a light emitting device using a phosphor that emits red light in addition to a phosphor that emits light from green to yellow has been proposed (see, for example, Patent Document 2).

Special Table 2003-535477 Japanese Unexamined Patent Publication No. 2008-034188

In the light emitting device of the prior art, by using a phosphor that emits light such as yellow, green, and red, the color difference in the wavelength region corresponding to them can be reduced to some extent. However, it has been difficult to reduce the color difference in the blue region by bringing the emission intensity in the blue region mainly derived from the light emitting element closer to the reference light source. For example, it is conceivable to adjust the emission intensity of blue by adjusting the amount of phosphor or adding a diffusing material, but a satisfactory solution has not been reached. Here, the special color rendering index R12 is generally largely involved in light emission in the blue wavelength region, and the value of R12 tends to be low in the light emitting device of the prior art. In order to obtain a light emitting device with high color reproducibility, light is emitted so as to obtain a series of continuous emission spectra such as purple to blue, green to yellow, and orange to red like a solar light source in the visible light region. It is necessary to configure the device to increase the value of R12.

As a light emitting device that solves such a problem, there is a light emitting device that uses a light emitting element having an emission peak wavelength in the near-ultraviolet region that does not contribute to the calculation of the color rendering index. However, since the light in the near-ultraviolet region contains a large amount of ultraviolet rays, it not only adversely affects the human body and the irradiated object, but also deteriorates the components of the light emitting device and greatly reduces the luminous efficiency of the light emitting device. There was a problem of doing.

Therefore, one embodiment of the present disclosure aims to solve the above-mentioned problems and provide a light emitting device having excellent color rendering properties.

Specific means for solving the above problems are as follows, and the present disclosure includes the following aspects.
The first aspect is a light emitting device including a light emitting element having a light emitting peak wavelength in the range of 410 nm or more and 440 nm or less, and a fluorescent member. The fluorescent member has a emission peak wavelength in the range of 430 nm or more and 500 nm or less as a phosphor, a first phosphor containing an alkaline earth phosphate having Cl in the composition and activated by Eu, and 440 nm or more and 550 nm. A second phosphor having an emission peak wavelength in the following range and containing at least one of an alkaline earth aluminate activated by Eu and a silicate having Ca, Mg and Cl in the composition and activated by Eu. A third phosphor containing a rare earth aluminate activated by Ce, which has an emission peak wavelength in the range of 500 nm or more and 600 nm or less, and an emission peak wavelength in the range of 610 nm or more and 650 nm or less, Sr and Ca. A fourth phosphor containing silicon nitride that has at least one of the above and Al and is activated by Eu, and a fluorogermanate that has an emission peak wavelength in the range of 650 nm or more and 670 nm or less and is activated by Mn. Includes a fifth fluorophore, including.

According to one embodiment of the present disclosure, it is possible to provide a light emitting device having excellent color rendering properties.

It is the schematic sectional drawing which shows an example of the light emitting device which concerns on this embodiment. It is a figure which shows the emission spectrum of the light emitting apparatus which concerns on Examples 1 to 3 and Comparative Example 1. It is a figure which shows the emission spectrum of the light emitting apparatus which concerns on Examples 4 to 7 and Comparative Example 1. It is a figure which shows the emission spectrum of the light emitting apparatus which concerns on Examples 8 to 11 and Comparative Example 2. It is a figure which shows the emission spectrum of the light emitting apparatus which concerns on Examples 12 to 15 and Comparative Example 2. It is a figure which shows the emission spectrum of the light emitting apparatus which concerns on Examples 16 to 19 and Comparative Example 3. It is a figure which shows the emission spectrum of the light emitting apparatus which concerns on Examples 20 to 23 and Comparative Example 3. It is a figure which shows the emission spectrum of the light emitting apparatus which concerns on Example 24 and Comparative Example 4. It is a figure which shows the emission spectrum of the light emitting apparatus which concerns on Example 25 and Comparative Example 5.

Hereinafter, modes for carrying out the present invention will be described. However, the embodiments shown below exemplify a light emitting device for embodying the technical idea of the present invention, and the present invention is not limited to the following light emitting devices. In this specification, the relationship between the color name and the chromaticity coordinate, the relationship between the wavelength range of light and the color name of monochromatic light, and the like are in accordance with JIS Z8110. In addition, the content of each component in the composition means the total amount of the plurality of substances present in the composition when a plurality of substances corresponding to each component are present in the composition, unless otherwise specified. ..

[Light emitting device]
FIG. 1 is a schematic cross-sectional view of a light emitting device according to an embodiment of the present disclosure. The light emitting device 100 includes a light emitting element 10 having a light emitting peak wavelength in the range of 410 nm or more and 440 nm or less, and a fluorescent member 50. The fluorescent member 50 includes at least five types of the phosphor 70, the first phosphor 71, the second phosphor 72, the third phosphor 73, the fourth phosphor 74, and the fifth phosphor 75. The first phosphor 71 contains an alkaline earth phosphate having an emission peak wavelength in the range of 430 nm or more and 500 nm or less, having Cl in its composition, and being activated by Eu. The second phosphor 72 has an emission peak wavelength in the range of 440 nm or more and 550 nm or less, and has an alkaline earth aluminate activated by Eu and a silicate having Ca, Mg and Cl in the composition and activated by Eu. Contains at least one of the salts. The third phosphor 73 contains a rare earth aluminate having an emission peak wavelength in the range of 500 nm or more and 600 nm or less and activated by Ce. The fourth phosphor 74 contains a silicon nitride having an emission peak wavelength in the range of 610 nm or more and 650 nm or less, having at least one of Sr and Ca and Al in the composition, and being activated by Eu. The fifth phosphor 75 contains a fluorogermanate having an emission peak wavelength in the range of 650 nm or more and 670 nm or less and activated by Mn. The content of the first phosphor 71 with respect to the total amount of the phosphor 70 contained in the fluorescent member 50 is preferably 20% by mass or more and 80% by mass or less.

By providing a light emitting element 10 having a specific emission peak wavelength and a fluorescent member 50 containing at least five specific phosphors and containing the first phosphor 71 in a specific range, the number of color performance evaluations can be increased. The emission spectrum of the light emitting device 100 can be brought close to the spectrum of the reference light source in an extremely wide range from the short wave side to the long wave side of the visible light region according to the calculation. This makes it possible to achieve excellent color rendering properties. Further, by including the light emitting element 10 having a light emitting peak in a specific wavelength region, safety as a light source and high luminous efficiency can be achieved. Further, by providing the specific light emitting element 10 and the fluorescent member 50 containing the first phosphor 71 in a specific content, the special color rendering index R12 can be particularly improved.

Regarding the average color rendering index Ra, the CIE (International Commission on Illumination) published a guideline for color rendering that fluorescent lamps should have in 1986. According to the guideline, the preferred average color rendering index Ra according to the place of use is 60 or more and less than 80 in the factory where general work is performed, and the house, hotel, restaurant, store, office, school, hospital, precision work is performed. It is said to be 80 or more and less than 90 in factories, etc., and 90 or more in places where clinical examinations that require high color rendering properties, museums, etc.

The Ra of the light emitting device 100 according to the present embodiment is, for example, 80 or more, preferably 90 or more, and more preferably 95 or more. The special color rendering evaluation numbers R9 to R15 of the light emitting device 100 are, for example, 50 or more, preferably 70 or more, and more preferably 90 or more. In particular, R12 is, for example, 60 or more, preferably 75 or more, and more preferably 90 or more. The sum of the special color rendering evaluation numbers R9 to R15 (hereinafter, also referred to as Rt) is, for example, 570 or more, preferably 600 or more, and more preferably 650 or more.

The light emitted by the light emitting device 100 is a mixture of the light of the light emitting element 10 and the fluorescence emitted by the first phosphor 71, the second phosphor 72, the third phosphor 73, the fourth phosphor 74, and the fifth phosphor 75. It is light, for example, the chromaticity coordinates defined in CIE1931 can be light included in the range of x = 0.00 to 0.50 and y = 0.00 to 0.50, and x = 0. It can also be light included in the range of .25 to 0.40 and y = 0.25 to 0.40. The correlated color temperature of the light emitted by the light emitting device 100 is, for example, 2000 K or more or 2500 K or more. The correlated color temperature is 7500 K or less or 7000 K or less.

The light emitting device 100 according to the present embodiment will be described in detail with reference to FIG. 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 the range of 380 nm or more and 485 nm or less), and has a gallium nitride compound semiconductor light emitting element 10 having a emission peak wavelength in the range of 410 nm or more and 440 nm or less. It has a molded body 40 on which the light emitting element 10 is placed. The molded body 40 is formed by integrally molding the first lead 20, the second lead 30, and the resin portion 42. Alternatively, the molded body 40 can be formed by using a method already known using ceramics as a material instead of the resin portion 42. 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 a wire 60, respectively. The light emitting element 10 is covered with a fluorescent member 50. The fluorescent member 50 includes, for example, the first phosphor 71, the second phosphor 72, the third phosphor 73, the fourth phosphor 74, and the fifth phosphor 75 as the phosphor 70 for wavelength-converting the light from the light emitting element 10. It contains at least 5 kinds of phosphors and a resin.

(Light emitting element 10)
The emission peak wavelength of the light emitting element 10 is preferably in the range of 410 nm or more and 440 nm or less, and preferably in the range of 420 nm or more and 440 nm or less from the viewpoint of luminous efficiency. By using the light emitting element 10 having an emission peak wavelength in this range as an excitation light source, it is possible to configure a light emitting device 100 that emits a mixed color light of the light from the light emitting element 10 and the fluorescence from the phosphor 70. Further, since the light radiated from the light emitting element 10 to the outside can be effectively used, the loss of the light emitted from the light emitting device 100 can be reduced, and the highly efficient light emitting device 100 can be obtained. Further, since the emission peak wavelength is on the longer wavelength side than the near-ultraviolet region and the component of ultraviolet rays is small, the safety as a light source and the emission efficiency are excellent.

The half width of the emission spectrum of the light emitting element 10 can be, for example, 30 nm or less.
It is preferable to use a semiconductor light emitting element such as an LED for the light emitting element 10. By using a semiconductor light emitting device as a light source, it is possible to obtain a stable light emitting device 100 having high efficiency, high linearity of output with respect to input, and resistance to mechanical impact.
As the semiconductor light emitting element, for example, a nitride-based semiconductor (In _X Al _Y Ga _1-XY N, where X and Y satisfy 0 ≦ X, 0 ≦ Y, and X + Y ≦ 1) is used in blue. , A semiconductor light emitting element that emits light such as green can be used.

(Fluorescent member 50)
The fluorescent member 50 can include, for example, a phosphor 70 and a resin (not shown). As the phosphor 70, the fluorescent member 50 includes at least one of the first phosphor 71 that absorbs the light emitted from the light emitting element 10 and emits blue light, and at least one of the second phosphor 72 that emits green light. It contains at least one of the third phosphor 73 that emits yellow light, at least one of the fourth phosphor 74 that emits red light, and at least one of the fifth phosphor 75 that emits deep red light. The first phosphor 71 to the fifth phosphor 75 have different compositions from each other. By appropriately selecting the composition ratios of the first phosphor 71 to the fifth phosphor 75, the characteristics such as the luminous efficiency and the color rendering property of the light emitting device 100 can be set in a desired range.

First phosphor 71
The first phosphor 71 is a blue-emitting phosphor having an emission peak wavelength in the range of 430 nm or more and 500 nm or less, having Cl in its composition, and containing an alkaline earth phosphate activated by Eu. The first phosphor 71 preferably has, for example, a composition represented by the following formula (1), and more preferably has a composition represented by the following formula (1'). As a result, each emission characteristic of the first phosphor 71 described below can be obtained relatively easily.
(Ca, Sr, Ba) ₅ (PO ₄ ) ₃ (Cl, Br): Eu (1)
Ca ₅ (PO ₄ ) ₃ Cl: Eu (1')

The maximum excitation wavelength of the first phosphor 71 is, for example, 360 nm or more and 440 nm or less, preferably 370 nm or more and 430 nm or less. It can be efficiently excited within the range of the emission peak wavelength of the light emitting element 10. The emission peak wavelength of the first phosphor 71 is, for example, in the range of 430 nm or more and 500 nm or less, and preferably in the range of 440 nm or more and 480 nm or less. Within such a range, the emission spectrum of the light emitting device 100 overlaps the emission spectrum of the first phosphor 71 with the emission spectrum of the light emitting element 10 and the emission spectrum of the second phosphor 72, especially in the blue region. Less. Further, the emission spectrum of the light emitting device 100 is brought closer to the reference light source by the emission spectrum of the first phosphor 71 and the emission spectrum of the light emitting element 10 in the blue region, which was conventionally derived only from the light emitting element. This facilitates the process, and the color rendering property of the light emitting device 100 can be improved. The full width at half maximum in the emission spectrum of the first phosphor 71 is, for example, 29 nm or more and 49 nm or less, preferably 34 nm or more and 44 nm or less. By setting the range in such a half width, the color purity can be improved, the emission spectrum in the blue region can be brought closer to the reference light source, and the color rendering property of the light emitting device 100 can be further improved.

For example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 2000 K or more and 7500 K or less, the content of the first phosphor 71 with respect to the total amount of the phosphor in the fluorescent member 50 (first phosphor amount / total phosphor amount; Hereinafter, it is also simply referred to as “content of the first phosphor 71”), for example, 20% by mass or more, preferably 25% by mass or more, and more preferably 40% by mass or more. The content of the first phosphor 71 is, for example, 80% by mass or less, preferably 75% by mass or less, and more preferably 70% by mass or less. When the content of the first phosphor 71 is within the above range, the emission spectrum of the light emitting device 100 can be brought closer to the reference light source, so that the color rendering property can be further improved.

For example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 2000 K or more and 7500 K or less, the content ratio of the first phosphor 71 to the third phosphor 73 (first phosphor / third phosphor) is, for example, 0. It is 3 or more and 7 or less, preferably 0.5 or more and 6.5 or less, more preferably 0.6 or more and 6 or less, and further preferably 1.8 or more and 6 or less. When the content ratio is within the above range, the emission spectrum of the light emitting device 100 can be brought closer to the reference light source, so that the color rendering property can be further improved.

In the emission spectrum obtained from the light emitting device 100 with the wavelength on the horizontal axis and the relative emission intensity on the vertical axis, the ratio of the emission peak intensity of the first phosphor 71 to the emission peak intensity of the light emitting element 10 (first phosphor 71). (Emission peak intensity / emission peak intensity of the light emitting element 10; hereinafter, also simply referred to as "emission peak intensity ratio") is, for example, in the case of a light emitting device 100 that emits light having a correlated color temperature of 2000 K or more and 7500 K or less, for example, 0. It is 15 or more and 2 or less, preferably 0.3 or more and 1.8 or less, and more preferably 0.5 or more and 1.5 or less. When the emission peak intensity ratio is within the above range, the emission spectrum of the emission apparatus 100 can be brought closer to the reference light source, so that the color rendering property can be further improved. Here, as for the emission peak intensity ratio, the maximum value of the emission intensity in the range of 410 nm or more and 440 nm or less is regarded as the emission peak intensity of the light emitting element 10, and the maximum value of the emission intensity in the range of more than 440 nm and 470 nm or less is the first phosphor. It is calculated assuming that it is the emission peak intensity of 71.

Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 5500 K or more and 7500 K or less, the content of the first phosphor 71 is, for example, 30% by mass or more, preferably 35% by mass or more, preferably 45. It is more preferably mass% or more. The content of the first phosphor 71 is, for example, 80% by mass or less, preferably 77% by mass or less, and more preferably 75% by mass or less. When the content ratio is within the above range, the emission spectrum of the light emitting device can be brought closer to the reference light source, so that the color rendering property can be further improved.

Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 5500 K or more and 7500 K or less, the content ratio of the first phosphor 71 to the third phosphor 73 is, for example, 0.9 or more and 6 or less, and is 1.5. It is preferably 5.9 or more, and more preferably 2.5 or more and 5.85 or less. When the content ratio is within the above range, the emission spectrum of the light emitting device 100 can be brought closer to the reference light source, so that the color rendering property can be further improved.

Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 5500 K or more and 7500 K or less, the emission peak intensity ratio of the first phosphor 71 to the light emitting element 10 is, for example, 0.4 or more and 1.5 or less, and is 0. It is preferably .45 or more and 1.47 or less, and more preferably 0.70 or more and 1.44 or less. When the emission peak intensity ratio is within the above range, the emission spectrum of the emission apparatus 100 can be brought closer to the reference light source, so that the color rendering property can be further improved.

Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 4500 K or more and less than 5500 K, the content of the first phosphor 71 is, for example, 30% by mass or more, preferably 45% by mass or more, preferably 55. It is more preferably mass% or more. The content of the first phosphor 71 is, for example, 80% by mass or less, preferably 78% by mass or less, and more preferably 76% by mass or less. When the content ratio is within the above range, the emission spectrum of the light emitting device 100 can be brought closer to the reference light source, so that the color rendering property can be further improved.

Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 4500 K or more and less than 5500 K, the content ratio of the first phosphor 71 to the third phosphor 73 is, for example, 0.8 or more and 5.5 or less. It is preferably 5.5 or more and 5.4 or less, and more preferably 2 or more and 5.35 or less. When the content ratio is within the above range, the emission spectrum of the light emitting device 100 can be brought closer to the reference light source, so that the color rendering property can be further improved.

Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 4500 K or more and less than 5500 K, the emission peak intensity ratio of the first phosphor 71 to the light emitting element 10 is, for example, 0.4 or more and 1.5 or less, and is 0. It is preferably 5.5 or more and 1.45 or less, and more preferably 0.6 or more and 1.4 or less. When the emission peak intensity ratio is within the above range, the emission spectrum of the emission apparatus 100 can be brought closer to the reference light source, so that the color rendering property can be further improved.

Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 3500 K or more and less than 4500 K, the content of the first phosphor 71 is, for example, 20% by mass or more, preferably 50% by mass or more, preferably 55. It is more preferably mass% or more. The content of the first phosphor 71 is, for example, 75% by mass or less, preferably 70% by mass or less, and more preferably 64% by mass or less. When the content ratio is within the above range, the emission spectrum of the light emitting device 100 can be brought closer to the reference light source, so that the color rendering property can be further improved.

Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 3500 K or more and less than 4500 K, the content ratio of the first phosphor 71 to the third phosphor 73 is, for example, 0.6 or more and 4.2 or less. It is preferably 0.8 or more and 4 or less, and more preferably 2.2 or more and 3.3 or less. When the content ratio is within the above range, the emission spectrum of the light emitting device 100 can be brought closer to the reference light source, so that the color rendering property can be further improved.

Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 3500 K or more and less than 4500 K, the emission peak intensity ratio of the first phosphor 71 to the light emitting element 10 is, for example, 0.3 or more and 1.3 or less, and is 0. It is preferably 6.6 or more and 1.25 or less, and more preferably 0.8 or more and 1.1 or less. When the emission peak intensity ratio is within the above range, the emission spectrum of the emission apparatus 100 can be brought closer to the reference light source, so that the color rendering property can be further improved.

Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 2500 K or more and less than 3500 K, the content of the first phosphor 71 is, for example, 30% by mass or more, preferably 35% by mass or more, preferably 40% or more. It is more preferably mass% or more. The content of the first phosphor 71 is, for example, 65% by mass or less, preferably 60% by mass or less, and more preferably 55% by mass or less. When the content ratio is within the above range, the emission spectrum of the light emitting device 100 can be brought closer to the reference light source, so that the color rendering property can be further improved.

Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 2500 K or more and less than 3500 K, the content ratio of the first phosphor 71 to the third phosphor 73 is, for example, 1 or more and 4 or less, and 1.5 or more and 3 It is preferably 1.5 or less, and more preferably 1.7 or more and 2.7 or less. When the content ratio is within the above range, the emission spectrum of the light emitting device 100 can be brought closer to the reference light source, so that the color rendering property can be further improved.

Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 2500 K or more and less than 3500 K, the emission peak intensity ratio of the first phosphor 71 to the light emitting element 10 is, for example, 0.2 or more and 1.4 or less, and is 0. It is preferably 5.5 or more and 1.2 or less, and more preferably 0.7 or more and 1.1 or less. When the emission peak intensity ratio is within the above range, the emission spectrum of the emission apparatus 100 can be brought closer to the reference light source, so that the color rendering property can be further improved.

Second phosphor 72
The second phosphor 72 has an emission peak wavelength in the range of 440 nm or more and 550 nm or less, and is an alkaline earth aluminate activated by Eu, and a silicate having Ca, Mg and Cl in the composition and activated by Eu. A green luminescent fluorophore containing at least one of the acid salts. The second phosphor 72 preferably contains at least the alkaline earth aluminate. The alkaline earth aluminate preferably has a composition represented by the following formula (2a), and more preferably has a composition represented by the following formula (2a'). The silicate preferably has, for example, a composition represented by the following formula (2b), and more preferably has a composition represented by the following formula (2b'). By having a specific composition, each emission characteristic of the second phosphor 72 described below can be obtained relatively easily.
(Sr, Ca, Ba) ₄ Al ₁₄ O ₂₅ : Eu (2a)
Sr ₄ Al ₁₄ O ₂₅ : Eu (2a')
(Ca, Sr, Ba) ₈ MgSi ₄ O ₁₆ (F, Cl, Br) ₂ : Eu (2b)
Ca ₈ MgSi ₄ O ₁₆ Cl ₂ : Eu (2b')

When the second phosphor 72 has the composition represented by the formula (2b), the second phosphor 72 contains at least one selected from the group consisting of Ca, Sr and Ba, but preferably contains at least Ca. , Ca, Sr and Ba, the Ca content is more preferably 90 mol% or more. The second phosphor contains at least one selected from the group consisting of F, Cl and Br, but preferably contains at least Cl, and the Cl content of F, Cl and Br is 90 mol% or more. Is more preferable.

The maximum excitation wavelength of the second phosphor 72 is, for example, 270 nm or more and 470 nm or less, preferably 370 nm or more and 460 nm or less. It can be efficiently excited within the range of the emission peak wavelength of the light emitting element 10.
When the second phosphor 72 has the composition represented by the formula (2a), its emission peak wavelength is, for example, 400 nm or more and 550 nm or less, and preferably 460 nm or more and 530 nm or less. The full width at half maximum in the emission spectrum is, for example, 58 nm or more and 78 nm or less, preferably 63 nm or more and 73 nm or less.
When the second phosphor 72 has the composition represented by the formula (2b), its emission peak wavelength is, for example, 510 nm or more and 540 nm or less, preferably 520 nm or more and 530 nm or less. The full width at half maximum in the emission spectrum is, for example, 50 nm or more and 75 nm or less, preferably 58 nm or more and 68 nm or less.
By using at least one of such second phosphors 72, the color purity can be improved, the emission spectrum in the green region can be brought closer to the reference light source, and the color rendering property of the light emitting device 100 can be further improved. it can.

For example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 2000 K or more and 7500 K or less, the content of the second phosphor 72 with respect to the total amount of the phosphor in the fluorescent member 50 (second phosphor amount / total phosphor amount; Hereinafter, it is also simply referred to as “content of the second phosphor 72”) is 0.5% by mass or more, preferably 0.7% by mass or more, and more preferably 1% by mass or more. .. The content of the second phosphor 72 is 30% by mass or less, preferably 20% by mass or less, and more preferably 15% by mass or less.

Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 5500 K or more and 7500 K or less, the content of the second phosphor 72 is, for example, 4% by mass or more, preferably 5% by mass or more, and 6 It is more preferably mass% or more. The content of the second phosphor 72 is, for example, 20% by mass or less, preferably 13% by mass or less, and more preferably 11% by mass or less.
Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 4500 K or more and less than 5500 K, the content of the second phosphor 72 is, for example, 0.5% by mass or more and 0.7% by mass or more. Is preferable, and 1% by mass or more is more preferable. The content of the second phosphor 72 is, for example, 4% by mass or less, preferably 3% by mass or less, and more preferably 2% by mass or less.
Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 3500 K or more and less than 4500 K, the content of the second phosphor 72 is, for example, 1.5% by mass or more, preferably 2% by mass or more. More preferably, it is 2.2% by mass or more. The content of the second phosphor 72 is, for example, 5% by mass or less, preferably 3.5% by mass or less, and more preferably 3% by mass or less.
Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 2500 K or more and less than 3500 K, the content of the second phosphor 72 is, for example, 1.5% by mass or more, preferably 2% by mass or more. More preferably, it is 2.2% by mass or more. The content of the second phosphor 72 is, for example, 5% by mass or less, preferably 3.5% by mass or less, and more preferably 3% by mass or less.
When the content of the second phosphor 72 is within the above range, the emission spectrum in the green region of the light emitting device 100 can be brought closer to the reference light source, and the color rendering property can be further improved.

Third phosphor 73
The third phosphor 73 is a yellow-emitting phosphor having an emission peak wavelength in the range of 500 nm or more and 600 nm or less and containing a rare earth aluminate activated by Ce. The third phosphor 73 preferably has, for example, a composition represented by the following formula (3), and more preferably has a composition represented by the following formula (3'). As a result, each emission characteristic of the third phosphor 73 described below can be obtained relatively easily.
(Y, Lu, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce (3)
Y ₃ Al ₅ O ₁₂ : Ce (3')

The maximum excitation wavelength of the third phosphor 73 is, for example, 220 nm or more and 490 nm or less, preferably 430 nm or more and 470 nm or less. It can be efficiently excited within the range of the emission peak wavelength of the light emitting element 10. The peak wavelength of the third phosphor 73 is, for example, 480 nm or more and 630 nm or less, preferably 500 nm or more and 560 nm or less. By setting it in such a range, the overlap with the emission spectrum of the second phosphor 72 can be reduced, the emission spectrum in the yellow region can be brought closer to the reference light source, and the color rendering property of the light emitting device 10 can be further improved. it can. The full width at half maximum in the emission spectrum of the third phosphor 73 is, for example, 95 nm or more and 115 nm or less, preferably 100 nm or more and 110 nm or less. By setting the range in such a half-value width, the color purity can be improved and the emission spectrum in the yellow region can be brought closer to the reference light source, so that the color rendering property of the light emitting device 100 can be further improved.

For example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 2000 K or more and 7500 K or less, the content of the third phosphor 73 with respect to the total amount of the phosphor in the fluorescent member 50 (third phosphor amount / total phosphor amount; Hereinafter, it is also simply referred to as “content of the third phosphor 73”), for example, 8% by mass or more, preferably 10% by mass or more, and more preferably 12% by mass or more. The content of the third phosphor 73 is, for example, 40% by mass or less, preferably 30% by mass or less, and more preferably 25% by mass or less.

Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 5500 K or more and 7500 K or less, the content of the third phosphor 73 is, for example, 8% by mass or more, preferably 10% by mass or more, preferably 12 It is more preferably mass% or more. The content of the third phosphor 73 is, for example, 40% by mass or less, preferably 30% by mass or less, and more preferably 22% by mass or less.
Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 4500 K or more and less than 5500 K, the content of the third phosphor 73 is, for example, 10% by mass or more, preferably 12% by mass or more, and 14 It is more preferably mass% or more. The content of the third phosphor 73 is, for example, 45% by mass or less, preferably 30% by mass or less, and more preferably 25% by mass or less.
Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 3500 K or more and less than 4500 K, the content of the third phosphor 73 is, for example, 10% by mass or more, preferably 15% by mass or more, and 17 More preferably, it is 5.5% by mass or more. The content of the third phosphor 73 is, for example, 50% by mass or less, preferably 35% by mass or less, and more preferably 25% by mass or less.
Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 2500 K or more and less than 3500 K, the content of the third phosphor 73 is, for example, 15% by mass or more, preferably 17.5% by mass or more. , 20% by mass or more is more preferable. The content of the third phosphor 73 is, for example, 40% by mass or less, preferably 30% by mass or less, and more preferably 25% by mass or less.
When the content of the third phosphor 73 is within the above range, the emission spectrum in the yellow region of the light emitting device 100 can be brought closer to the reference light source, and the color rendering property can be further improved.

Fourth phosphor 74
The fourth phosphor 74 has a emission peak wavelength in the range of 610 nm or more and 650 nm or less, has a composition of at least one of Sr and Ca and Al, and contains a silicon nitride activated by Eu. Is. The fourth phosphor 74 preferably has, for example, a composition represented by the following formula (4). As a result, each emission characteristic of the fourth phosphor 74 described below can be obtained relatively easily.
(Sr, Ca) AlSiN ₃ : Eu (4)

When the fourth fluorescent substance 74 has the composition represented by the formula (4), the fourth fluorescent substance 74 contains at least one selected from the group consisting of Sr and Ca, but may contain both Sr and Ca. It is preferable that both Sr and Ca are contained, and the Sr content of Sr and Ca is 0.8 mol% or more. Thereby, the emission peak wavelength of the fourth phosphor 74 can be set in a desired range.

The emission peak wavelength of the fourth phosphor 74 is, for example, 620 nm or more and 650 nm or less, preferably 630 nm or more and 645 nm or less. When it is equal to or more than the above lower limit value, the emission spectrum in the red region is brought closer to the reference light source without insufficient emission intensity between the emission peak wavelength of the fifth phosphor 75 and the emission peak wavelength of the fourth phosphor 74, which will be described later. be able to. When it is not more than the above upper limit value, the overlap between the emission spectrum of the fourth phosphor 74 and the emission spectrum of the fifth phosphor 75 can be reduced, and the effect of the emission spectrum of the fifth phosphor 75 can be efficiently obtained. Therefore, the color rendering property can be further improved. The full width at half maximum in the emission spectrum of the fourth phosphor 74 is, for example, 80 nm or more and 100 nm or less, preferably 85 nm or more and 95 nm or less. By setting the range in such a half width, the overlap between the emission spectrum of the fourth phosphor 74 and the emission spectrum of the fifth phosphor 75 is reduced, so that the effect of the emission spectrum of the fifth phosphor 75 is efficient. It is possible to further improve the color rendering property.

For example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 2000 K or more and 7500 K or less, the content ratio of the content of the fourth phosphor 74 to the total amount of the phosphor in the fluorescent member (fourth phosphor amount / total phosphor). Amount; hereinafter, also simply referred to as “content of the fourth phosphor 74”) is, for example, 0.5% by mass or more, preferably 1% by mass or more, and 1.5% by mass or more. Is more preferable. The content of the fourth phosphor 74 is, for example, 6% by mass or less, preferably 5% by mass or less, and more preferably 4% by mass or less.

Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 5500 K or more and 7500 K or less, the content of the fourth phosphor 74 is, for example, 1% by mass or more, preferably 1.5% by mass or more. More preferably, it is 2% by mass or more. The content of the fourth phosphor 74 is, for example, 6% by mass or less, preferably 4% by mass or less, and more preferably 3.8% by mass or less.
Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 4500 K or more and less than 5500 K, the content of the fourth phosphor 74 is, for example, 0.5% by mass or more, preferably 1% by mass or more. , 1.5% by mass or more is more preferable. The content of the fourth phosphor 74 is, for example, 3.5% by mass or less, preferably 3% by mass or less, and more preferably 2.6% by mass or less.
Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 3500 K or more and less than 4500 K, the content of the fourth phosphor 74 is, for example, 1% by mass or more, preferably 1.5% by mass or more. More preferably, it is 2.27% by mass or more. The content of the fourth phosphor 74 is, for example, 4.8% by mass or less, preferably 3.5% by mass or less, and more preferably 3% by mass or less.
Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 2500 K or more and less than 3500 K, the content of the fourth phosphor 74 is, for example, 2.5% by mass or more, preferably 3% by mass or more. More preferably, it is 3.2% by mass or more. The content of the fourth phosphor 74 is, for example, 4.5% by mass or less, preferably 4% by mass or less, and more preferably 3.5% by mass or less.
When the content of the fourth phosphor 74 is within the above range, the emission spectrum in the red region of the light emitting device 100 can be brought closer to the reference light source, and the color rendering property can be further improved.

Fifth phosphor 75
The fifth phosphor is a deep red phosphor that has an emission peak wavelength in the range of 650 nm or more and 670 nm or less and contains fluorogermanate activated by Mn. The fifth phosphor 75 is preferably at least one of fluorogermanates having a composition represented by the following formula (5a) or (5b), for example. The emission peak wavelength of the phosphor having the composition represented by the formula (5a) or (5b) is longer than that of other phosphors that emit red light, and is 650 nm or more. Therefore, the emission spectrum in the long wavelength region can be effectively brought closer to the reference light source, and the color rendering property of the light emitting device 100 can be further improved.
_{3.5MgO · 0.5MgF 2 · GeO 2:} Mn (5a)
(X-s) MgO · (s / 2) Sc ₂ O ₃ · yMgF ₂ · uCaF ₂ · (1-t) GeO ₂ · (t / 2) M ^t ₂ O ₃ : zMn (5b)

However, in the formula (5b), x, y, z, s, t and u are 2.0 ≦ x ≦ 4.0, 0 <y <1.5, 0 <z <0.05, 0 ≦ s. It is preferable to satisfy <0.5, 0 <t <0.5, 0 ≦ u <1.5, and further satisfy y + u <1.5. Further, M ^t in the above general formula (5b) is at least one selected from the group consisting of Al, Ga and In.

In the formula (5b), preferably 0.05 ≦ s ≦ 0.3 and 0.05 ≦ t <0.3, which can further improve the brightness. Further, the fifth phosphor 75 preferably has a composition represented by the following formula (5b'). As a result, the fifth phosphor 75 can be efficiently excited by the light in the wavelength range including the emission peak wavelength of the light emitting element 10.
_{3.4MgO · 0.1Sc 2 O 3 · 0.5MgF} 2 · 0.885GeO 2 · 0.1Ga 2 O 3: 0.015Mn (5b ')

The full width at half maximum in the emission spectrum of the fifth phosphor 75 is, for example, 45 nm or less, preferably 40 nm or less. By setting the range in such a half width, the color purity can be improved, the emission spectrum in the red region can be brought closer to the reference light source, and the color rendering property of the light emitting device 100 can be further improved. Further, in the emission spectrum of the fifth phosphor 75, when the maximum emission intensity is 100%, the average emission intensity in the range of 600 nm or more and 620 nm or less is, for example, 20% or less, and preferably 10% or less. Within the above range, the emission spectrum of the fifth phosphor 75, which will be described later, is less likely to overlap with the emission spectrum of the fourth phosphor 74, so that the effect of the emission spectrum of the fourth phosphor 74 can be obtained more efficiently. Therefore, the color playability can be further improved.

For example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 2000 K or more and 7500 K or less, the content of the fifth phosphor 75 with respect to the total amount of the phosphor in the fluorescent member 50 (fifth phosphor amount / total phosphor amount; Hereinafter, it is also simply referred to as “content of the fifth phosphor 75”), for example, 1% by mass or more, preferably 2% by mass or more, and more preferably 3% by mass or more. The content of the fifth phosphor 75 is, for example, 40% by mass or less, preferably 35% by mass or less, and more preferably 30% by mass or less.

Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 5500 K or more and 7500 K or less, the content of the fifth phosphor 75 is, for example, 1% by mass or more, preferably 2% by mass or more, and 3 It is more preferably mass% or more. The content of the fifth phosphor 75 is, for example, 12% by mass or less, preferably 6% by mass or less, and more preferably 5.5% by mass or less.
Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 4500 K or more and less than 5500 K, the content of the fifth phosphor 75 is, for example, 3% by mass or more, preferably 5% by mass or more, and 7 It is more preferably mass% or more. The content of the fifth phosphor 75 is, for example, 30% by mass or less, preferably 20% by mass or less, and more preferably 15% by mass or less.
Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 3500 K or more and less than 4500 K, the content of the fifth phosphor 75 is, for example, 5% by mass or more, preferably 8% by mass or more, and 10%. It is more preferably mass% or more. The content of the fifth phosphor 75 is, for example, 28% by mass or less, preferably 20% by mass or less, and more preferably 16% by mass or less.
Further, for example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 2500 K or more and less than 3500 K, the content of the fifth phosphor 75 is, for example, 15% by mass or more, preferably 18% by mass or more, and 20 It is more preferably mass% or more. The content of the fifth phosphor 75 is, for example, 45% by mass or less, preferably 40% by mass or less, and more preferably 30% by mass or less.
When the content of the fifth phosphor 75 is within the above range, the emission spectrum in the red region of the light emitting device 100 can be brought closer to the reference light source, and the color rendering property can be further improved.

The fluorescent member 50 may contain other fluorescent materials other than the first fluorescent body 71 to the fifth fluorescent body 75, if necessary. Other _{phosphor, 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, (Ca, Sr, Ba) ₂ Si ₅ N ₈ : Eu, (Ca, Sr, Ba) S: Eu, (Ba, Sr, Ca) Ga ₂ S ₄ : Eu, K ₂ (Si, Ti, Ge) F ₆ : Mn and the like. When the fluorescent member 50 contains other phosphors, the content thereof is appropriately adjusted so as to obtain the light emitting characteristics according to the present invention. The content of the other phosphors is, for example, 2% by mass or less, preferably 1% by mass or less, based on the total amount of the phosphors.

(resin)
Examples of the resin constituting the fluorescent member 50 include a thermoplastic resin and a thermosetting resin. Specific examples of the thermosetting resin include modified silicone resins such as epoxy resin, silicone resin, and epoxy-modified silicone resin.

(Other ingredients)
The fluorescent member 50 may contain other components in addition to the phosphor 70 and the resin, if necessary. 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 contained as another component, the content thereof can be 0.01 to 20 parts by mass with respect to 100 parts by mass of the resin.

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

(Fluorescent body 70)
Prior to the production of the light emitting device 100, the first phosphor 71 to the fifth phosphor 75 shown below were prepared respectively.
As the first phosphor 71, a blue-emitting phosphor (hereinafter, also referred to as “CCA”) having a composition represented by Ca ₅ (PO ₄ ) ₃ Cl: Eu and having an emission peak wavelength in the vicinity of 460 nm is prepared. did.
As the second phosphor 72, a green-emitting phosphor (hereinafter, also referred to as “SAE”) having a composition represented by Sr ₄ Al ₁₄ O ₂₅ : Eu and having an emission peak wavelength in the vicinity of 494 nm was prepared.
As the third phosphor 73, a rare earth aluminum garnet phosphor (hereinafter, also referred to as “YAG”) having a composition represented by Y ₃ Al ₅ O ₁₂ : Ce and having an emission peak wavelength in the vicinity of 544 nm was prepared.
As the fourth phosphor 74, a red-emitting nitride phosphor (hereinafter, also referred to as “SCASSN”) having a composition represented by (Sr, Ca) AlSiN ₃ : Eu and having an emission peak wavelength of around 635 nm. Got ready.
As the fifth phosphor 75, it has a composition represented by 3.4 MgO · 0.1 Sc ₂ O _3. 0.5 MgF _2. 0.885 GeO _2. 0.1 Ga ₂ O ₃ : 0.015 Mn, and has an emission peak wavelength. A deep red luminescent phosphor (hereinafter, also referred to as “MGF”) having a wavelength of around 658 nm was prepared.

(Light emitting element 10)
As the light emitting element 10, a bluish-purple light emitting LED having a light emitting peak wavelength of 430 nm was prepared.

[Evaluation]
For the light emitting device 100 obtained in the following Examples and Comparative Examples, the chromaticity coordinates of the emitted color, the correlated color temperature (Tcp; K), the average color rendering index (Ra), and the special color rendering index (R9 to R15) are obtained. It was measured. Further, the sum of the special color rendering evaluation numbers R9 to R15 (hereinafter, also referred to as Rt) was calculated. The average color rendering index and the special color rendering index are also simply referred to as "color rendering index".
The emission spectrum of the light emitting device 100 was measured using a total luminous flux measuring device using an integrating sphere.

(Example 1)
Fabrication of Light Emitting Device 100 A light emitting element 10 which is a blue-violet light emitting LED having a emission peak wavelength of 430 nm, a first phosphor 71 (CCA), a second phosphor 72 (SAE), a third phosphor 73 (YAG), and a first The light emitting device 100 of Example 1 was produced by combining the tetrafluorescent body 74 (SCASN) and the fifth phosphor 75 (MGF) as follows.

The content of the first phosphor 71 (CCA) with respect to the total amount of phosphors was 33.3% on a mass basis, and the content of each other phosphor with respect to the total amount of phosphors was set to the value shown in Table 1 below and correlated. A fluorescent material 70 blended so that the color temperature was around 6500 K was added to the silicone resin, mixed and dispersed, and then defoamed to obtain a fluorescent material-containing resin composition. Here, the ratio of the content of the first phosphor to the amount of resin (first phosphor / resin) was 15%. Next, this phosphor-containing resin composition was injected onto the light emitting device 10, filled, and further heated to cure the resin composition. The light emitting device 100 of Example 1 was manufactured by such a step.

(Examples 2 to 7)
The light emitting devices 100 of Examples 2 to 7 were produced in the same manner as in Example 1 except that the mass-based content (%) of each phosphor was changed to the value shown in Table 1 below.

(Comparative Example 1)
As the phosphor 70, the second phosphor 72 (SAE), the third phosphor 73 (YAG), the fourth phosphor 74 (SCASN), and the fifth phosphor without using the first phosphor 71 (CCA). The light emitting device 100 of Comparative Example 1 was produced in the same manner as in Example 1 except that it was used in combination with the phosphor 75 (MGF).

Regarding the evaluation results of the light emitting device 100 obtained in Examples 1 to 7 and Comparative Example 1, the results other than the color rendering index are shown in Table 1 below, and the results of the color rendering index are shown in Table 2 below.

From Tables 1 and 2, Ra of Examples 1 to 7 is larger than that of Comparative Example 1 which does not contain the first phosphor 71 because the first phosphor 71 is contained. Further, in Examples 1 to 7, all of R9 to R15 could have a high value of 60 or more.
On the other hand, in Comparative Example 1 containing no first phosphor 71, Ra was smaller than that of any of the examples, and R12 was 38, which were considerably lower than those of the examples.

In Examples 1 to 7 and Comparative Example 1, as shown in Table 1, the correlated color temperature was in the range of 5500 K or more and 7500 K or less. In Examples 4, 5, 6 and 7, as shown in Table 1, the content of the first phosphor 71 with respect to the total amount of the phosphor is 60% by mass or more and 80% by mass or less with respect to the third phosphor 73. The content ratio of the first phosphor 71 is included in the range of 2.5 or more and 6.0 or less. In Examples 4, 5, 6 and 7, as shown in Table 2, the numerical value of R12 is 90 or more, and the numerical value of Rt is 650 or more, and the color rendering property is particularly excellent. I understand.

FIG. 2 shows the emission spectrum of the light emitting device 100 according to Comparative Example 1 and Examples 1 to 3, and FIG. 3 shows the emission spectrum of the light emitting device 100 according to Comparative Example 1 and Examples 4 to 7, respectively, at 530 nm. It is the figure which standardized and compared based on the strength. The emission spectra of FIGS. 2 and 3 show the relative emission intensity with respect to the wavelength. In Examples 4, 5, 6 and 7, as shown in Table 1, the intensity ratio of the emission peak of the first phosphor 71 to the light emitting element 10 in the emission spectrum is 0.7 or more and 1.5 or less. As shown in Table 2, these Examples 4, 5, 6 and 7 show a value of R12 of 90 or more and a value of Rt of 650 or more, indicating that the color rendering property is particularly excellent. ..

(Examples 8 to 15)
The light emitting devices 100 of Examples 8 to 15 were used in the same manner as in Example 1 except that the content of each phosphor was changed to the values shown in Table 3 below and the correlated color temperature was adjusted to around 5000 K. Made.

(Comparative Example 2)
As the phosphor 70, the second phosphor 72 (SAE), the third phosphor 73 (YAG), the fourth phosphor 74 (SCASN), and the fifth phosphor without using the first phosphor 71 (CCA). The light emitting device 100 of Comparative Example 2 was produced in the same manner as in Example 1 except that it was used in combination with the phosphor 75 (MGF) and the correlated color temperature was adjusted to around 5000 K.

Regarding the evaluation results of the light emitting device 100 obtained in Examples 8 to 15 and Comparative Example 2, the results other than the color rendering index are shown in Table 3 below, and the results of the color rendering index are shown in Table 4 below.

From Tables 3 and 4, Ra of Examples 8 to 15 is larger than that of Comparative Example 2 which does not contain the first phosphor 71 because the first phosphor 71 is contained. Further, in Examples 8 to 15, all of R9 to R15 could have a high value of 60 or more.
On the other hand, in Comparative Example 2 containing no first phosphor 71, Ra was smaller than that of any of the examples, and R12 was 35, which were considerably lower than those of the examples.

In Examples 8 to 15 and Comparative Example 2, as shown in Table 3, the correlated color temperature was in the range of 4500 K or more and 5500 K or less. In Examples 10, 11, 12, 13, 14, and 15, as shown in Table 3, the content of the first phosphor 71 with respect to the total amount of the phosphor is 55% by mass or more and 80% by mass or less, and the third The content ratio of the first phosphor 71 to the phosphor 73 is included in the range of 2.4 or more and 5.5 or less. In these Examples 10, 11, 12, 13, 14, and 15, as shown in Table 4, the numerical value of R12 is 90 or more, and the numerical value of Rt is 660 or more, and the color playability is particularly high. It turns out to be excellent.

FIG. 4 shows the emission spectra of the light emitting devices 100 according to Comparative Examples 2 and 8 to 11, and FIG. 5 shows the emission spectra of the light emitting devices 100 according to Comparative Examples 2 and 12 to 15, respectively, at 530 nm. It is the figure which standardized and compared based on the strength. The emission spectra of FIGS. 4 and 5 show the relative emission intensity with respect to the wavelength. In Examples 10, 11, 12, 13, 14 and 15, as shown in Table 3, the intensity ratio of the emission peak of the first phosphor 71 to the emission element 10 in the emission spectrum is 0.6 or more and 1.5 or less. Is. In these Examples 10, 11, 12, 13, 14 and 15, as shown in Table 4, the numerical value of R12 is 90 or more, and the numerical value of Rt is 660 or more, and the color rendering property is high. It turns out to be particularly good.

(Examples 16 to 23)
The light emitting devices 100 of Examples 16 to 23 were set in the same manner as in Example 1 except that the content of each phosphor was changed to the value shown in Table 5 below and the correlated color temperature was adjusted to around 4000 K. Made.

(Comparative Example 3)
As the phosphor 70, the second phosphor 72 (SAE), the third phosphor 73 (YAG), the fourth phosphor 74 (SCASN), and the fifth phosphor without using the first phosphor 71 (CCA). The light emitting device 100 of Comparative Example 3 was produced in the same manner as in Example 1 except that it was used in combination with the phosphor 75 (MGF) and the correlated color temperature was adjusted to around 4000 K.

Regarding the evaluation results of the light emitting device 100 obtained in Examples 16 to 23 and Comparative Example 3, the results other than the color rendering index are shown in Table 5 below, and the results of the color rendering index are shown in Table 6 below.

From Tables 5 and 6, Ra of Examples 16 to 23 is larger than that of Comparative Example 3 which does not contain the first phosphor 71 because the first phosphor 71 is contained. In addition, Examples 16 to 23 could have a high value of 60 or more in R9 to R15 as well.
On the other hand, in Comparative Example 3 containing no first phosphor 71, Ra was smaller than that of Example and R12 was 44, which was considerably lower than that of Example.

In Examples 16 to 23 and Comparative Example 3, as shown in Table 5, the correlated color temperature was in the range of 3500 K or more and 4500 K or less. In Examples 19, 20, 21 and 22, as shown in Table 5, the content of the first phosphor 71 with respect to the total amount of the phosphor is 55% by mass or more and 70% by mass or less with respect to the third phosphor 73. The content ratio of the first phosphor 71 is included in the range of 2.4 or more and 3.8 or less. In these Examples 19, 20, 21 and 22, as shown in Table 6, the numerical value of R12 is 90 or more, and the numerical value of Rt is 670 or more, indicating that the color rendering property is particularly excellent. ..

FIG. 6 shows the emission spectra of the light emitting devices 100 according to Comparative Examples 3 and 16 to 19, and FIG. 7 shows the emission spectra of the light emitting devices 100 according to Comparative Examples 3 and 20 to 23, respectively. It is the figure which standardized and compared based on the strength. The emission spectra of FIGS. 6 and 7 show the relative emission intensity with respect to the wavelength. In Examples 19, 20 and 21, as shown in Table 5, the intensity ratio of the emission peak of the first phosphor 71 to the light emitting element 10 in the emission spectrum is 0.8 or more and 1.1 or less. In Examples 19, 20 and 21, as shown in Table 6, the numerical value of R12 is 97 or more, and the numerical value of Rt is 680 or more, indicating that the color rendering property is particularly excellent.

(Example 24)
The light emitting device 100 of Example 24 was produced in the same manner as in Example 1 except that the content of each phosphor was changed to the value shown in Table 7 below and the correlated color temperature was adjusted to around 3000 K. ..

(Comparative Example 4)
As the phosphor 70, the second phosphor 72 (SAE), the third phosphor 73 (YAG), the fourth phosphor 74 (SCASN) and the fifth are not used as the first phosphor 71 (CCA). The light emitting device 100 of Comparative Example 4 was produced in the same manner as in Example 1 except that it was used in combination with the phosphor 75 (MGF) and the correlated color temperature was adjusted to around 3000 K.

(Example 25)
Emission of Example 25 in the same manner as in Example 1 except that the amount of the phosphor was changed so that the content of each phosphor was adjusted to the value shown in Table 7 below and the correlated color temperature was adjusted to around 2700 K. The device 100 was manufactured.

(Comparative Example 5)
As the phosphor 70, the second phosphor 72 (SAE), the third phosphor 73 (YAG), the fourth phosphor 74 (SCASN), and the fifth phosphor without using the first phosphor 71 (CCA). The light emitting device 100 of Comparative Example 5 was produced in the same manner as in Example 1 except that it was used in combination with the phosphor 75 (MGF) and the correlated color temperature was adjusted to around 2700 K.

Regarding the evaluation results of the light emitting device 100 obtained in Examples 24 and 25 and Comparative Examples 4 and 5, the results other than the color reproduction evaluation numbers are shown in Table 7 below, and the results of the color reproduction evaluation numbers are shown in Table 8 below.

From Tables 7 and 8, Ra is improved in Examples 24 and 25 as compared with Comparative Examples 4 and 5 in which the first phosphor 71 is not contained, because the first phosphor 71 is contained. In addition, Examples 24 and 25 could have a high value of 90 or more in R9 to R15.
On the other hand, in Comparative Example 4 containing no first phosphor 71, Ra was smaller than that of Example 24 and R12 was 51, which was considerably smaller than that of Example 24. Similarly, Comparative Example 5 containing no first fluorophore 71 had Ra smaller than Example 25 and R12 59, which was considerably smaller than Example 25.

In Examples 24 and 25 and Comparative Examples 4 and 5, as shown in Table 7, the correlated color temperature was in the range of 2000 K or more and 3500 K or less. In Examples 24 and 25, as shown in Table 7, the content of the first phosphor 71 with respect to the total amount of the phosphor is 40% by mass or more and 55% by mass or less, and the first phosphor with respect to the third phosphor 73. The content ratio of 71 is included in the range of 1.9 or more and 2.5 or less. As shown in Table 8, these Examples 24 and 25 have a R12 value of 90 or more and an Rt value of 680 or more, and are superior in color rendering properties to Comparative Examples 4 and 5. You can see that there is.

FIG. 8 defines the emission spectrum of the light emitting device 100 according to Comparative Example 4 and Example 24, and FIG. 9 defines the emission spectrum of the light emitting device 100 according to Comparative Example 5 and Example 25 based on the emission intensity of 530 nm. It is the figure which made and compared. The emission spectra of FIGS. 8 and 9 show the relative emission intensity with respect to the wavelength. In Examples 24 and 25, as shown in Table 8, the intensity ratio of the emission peak of the first phosphor 71 to the emission element 10 in the emission spectrum is 0.8 or more and 1.1 or less. As shown in Table 8, these Examples 24 and 25 have a R12 value of 90 or more and an Rt value of 680 or more, and are superior in color playability to Comparative Examples 4 and 5. You can see that there is.

The light emitting device of the present disclosure can be used for a lighting fixture, an LED display, a camera flashlight, a liquid crystal backlight light source, etc., which uses a blue light emitting diode or an ultraviolet light emitting diode as an excitation light source and has excellent light emitting characteristics. In particular, it can be suitably used for medical and art lighting devices and light sources for color comparison, which require high color rendering properties.

10: Light emitting element, 50: Fluorescent member, 70: Fluorescent material, 71: First fluorescent material, 72: Second fluorescent material, 73: Third fluorescent material, 74: Fourth fluorescent material, 75: Fifth fluorescent material, 100: Light emitting device

Claims (16)

A light emitting device including a light emitting element having a light emitting peak wavelength in the range of 410 nm or more and 440 nm or less, and a fluorescent member.
The fluorescent member can be used as a fluorescent substance.
A first phosphor having an emission peak wavelength in the range of 430 nm or more and 500 nm or less and having a half width of 29 nm or more and 49 nm or less in the emission spectrum.
A second phosphor having an emission peak wavelength in the range of 440 nm or more and 550 nm or less and having a half width in the emission spectrum of 58 nm or more and 78 nm or less, or 50 nm or more and 75 nm or less.
A third phosphor having an emission peak wavelength in the range of 500 nm or more and 600 nm or less and having a half width of 95 nm or more and 115 nm or less in the emission spectrum.
A fourth phosphor having an emission peak wavelength in the range of 610 nm or more and 650 nm or less and having a half width of 80 nm or more and 100 nm or less in the emission spectrum.
It includes a fifth phosphor having an emission peak wavelength in the range of 650 nm or more and 670 nm or less and having a half width of 45 nm or less in the emission spectrum thereof.
The ratio of the emission peak intensity of the first phosphor in the emission spectrum of the light emitting device to the emission peak intensity of the light emitting element is 0.3 or more and 1.8 or less.
It emits light with a correlated color temperature of 2000K or more and 7500K or less.
A light emitting device having a special color rendering index R12 of 60 or more. The light emitting device according to claim 1, wherein the content of the first phosphor with respect to the total amount of the phosphor is 20% by mass or more and 80% by mass or less. The light emitting device according to claim 1 or 2, which emits light having a correlated color temperature of 5500 K or more and 7500 K or less, and has an emission peak intensity ratio of 0.4 or more and 1.5 or less. The light emitting device according to claim 1 or 2, which emits light having a correlated color temperature of 4500 K or more and less than 5500 K, and has an emission peak intensity ratio of 0.4 or more and 1.5 or less. The light emitting device according to claim 1 or 2, which emits light having a correlated color temperature of 3500 K or more and less than 4500 K, and has an emission peak intensity ratio of 0.3 or more and 1.3 or less. The light emitting device according to claim 1 or 2, which emits light having a correlated color temperature of 2500 K or more and less than 3500 K, and has an emission peak intensity ratio of 0.5 or more and 1.4 or less. It emits light with a correlated color temperature of 5500K or more and 7500K or less.
The light emitting device according to claim 2, wherein the content of the first phosphor with respect to the total amount of the phosphor is 30% by mass or more and 80% by mass or less. The light emitting device according to claim 7, wherein the content ratio of the first phosphor to the third phosphor is 0.9 or more and 6 or less. It emits light with a correlated color temperature of 4500K or more and less than 5500K.
The light emitting device according to claim 2, wherein the content of the first phosphor with respect to the total amount of the phosphor is 30% by mass or more and 80% by mass or less. The light emitting device according to claim 9, wherein the content ratio of the first phosphor to the third phosphor is 0.8 or more and 5.5 or less. It emits light with a correlated color temperature of 3500K or more and less than 4500K.
The light emitting device according to claim 2, wherein the content of the first phosphor with respect to the total amount of the phosphor is 20% by mass or more and 75% by mass or less. The light emitting device according to claim 11, wherein the content ratio of the first phosphor to the third phosphor is 0.6 or more and 4.2 or less. It emits light with a correlated color temperature of 2500K or more and less than 3500K.
The light emitting device according to claim 2, wherein the content of the first phosphor with respect to the total amount of the phosphor is 40% by mass or more and 55% by mass or less. The light emitting device according to claim 13, wherein the content ratio of the first phosphor to the third phosphor is 1.9 or more and 2.5 or less. The ratio of the emission peak intensity of the first phosphor to the emission peak intensity of the light emitting element in the emission spectrum is 0.5 or more and 1.5 or less.
The light emitting device according to any one of claims 1 to 14, wherein the special color rendering index R12 is 80 or more. The light emitting device according to any one of claims 1 to 15, wherein the sum of the special color rendering evaluation numbers R9 to R15 is 600 or more.