JP6477779B2 - Light emitting device - Google Patents

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 a blue light emitting LED and a yellow light emitting phosphor. This light emitting device emits white light by mixing the blue light of the LED with yellow light from the phosphor excited by the light. In such a light emitting device, although the radiation intensity in the visible light region is strong and the light emission efficiency is high, 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 color appearance of the irradiated object (hereinafter referred to as “color rendering”).

  Here, the evaluation procedure of the color rendering properties of the light source is the color difference ΔEi (i is the i) when the test colors (R1 to R15) having predetermined reflectance characteristics are measured by the test light source and the reference light source according to JIS Z8726. It is determined that the color rendering index 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 corresponding to the color temperature, the higher the color rendering index approaches 100 and becomes higher. Among the color rendering indices, the average value of R1 to R8 is called an average color rendering index (hereinafter also referred to as Ra), and R9 to R15 are called special color rendering indices. 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 a blue light emitting LED and a chlorosilicate phosphor and a Y or Tb garnet phosphor as two types of phosphors emitting green to yellow is proposed. (For example, refer to Patent Document 1). In order to further improve color rendering properties, 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 JP 2008-034188 A

  In the light emitting device of the prior art, by using phosphors that emit light of yellow, green, red, etc., 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 light emission intensity of the blue region mainly derived from the light emitting element close to the reference light source. For example, it is conceivable to adjust the intensity of blue light emission by adjusting the amount of phosphor or adding a diffusing material, but it has not yet been a satisfactory solution. Here, the special color rendering index R12 generally involves a large amount of light emission in the blue wavelength region, and the light emitting device of the prior art tends to have a lower value of R12. In order to obtain a light emitting device having high color rendering properties, light emission is performed in a visible light range so that a series of continuous emission spectrums such as purple to blue, green to yellow, and orange to red are obtained. It is necessary to configure the device to increase the value of R12.

  As a light-emitting device that solves such a problem, 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 can be mentioned. However, since the light in the near ultraviolet region contains a lot of ultraviolet components, it not only adversely affects the human body and the irradiated object, but also the components of the light emitting device are deteriorated, and the luminous efficiency of the light emitting device is greatly reduced. There was a problem to do.

  Accordingly, an object of one embodiment of the present disclosure is to solve the above-described problem 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.
A 1st aspect is a light-emitting device provided with the light emitting element which has a light emission peak wavelength in the range of 410 nm or more and 440 nm or less, and a fluorescent member. The fluorescent member has a light emission peak wavelength in a range of 430 nm or more and 500 nm or less as a phosphor, a first phosphor containing an alkaline earth phosphate that has Cl as a composition and is activated by Eu, and 440 nm to 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 activated by Eu having Ca, Mg and Cl in the composition And a third phosphor containing a rare earth aluminate having an emission peak wavelength in the range of 500 nm to 600 nm and activated by Ce, an emission peak wavelength in the range of 610 nm to 650 nm, Sr and Ca A fourth phosphor containing silicon nitride having a composition containing at least one of Al and Al, and emitting light in a range of 650 nm to 670 nm Have over peak wavelength includes a fifth phosphor comprising fluoroelastomer jar money bets that are activated with Mn, the.

  According to an embodiment of the present disclosure, a light emitting device having excellent color rendering properties can be provided.

It is a schematic sectional drawing which shows an example of the light-emitting device which concerns on this embodiment. 6 is a diagram showing emission spectra of light emitting devices according to Examples 1 to 3 and Comparative Example 1. FIG. It is a figure which shows the emission spectrum of the light-emitting device which concerns on Examples 4-7 and the comparative example 1. FIG. It is a figure which shows the emission spectrum of the light-emitting device which concerns on Examples 8-11 and the comparative example 2. FIG. It is a figure which shows the emission spectrum of the light-emitting device which concerns on Examples 12-15 and the comparative example 2. FIG. It is a figure which shows the emission spectrum of the light-emitting device which concerns on Examples 16-19 and the comparative example 3. FIG. It is a figure which shows the emission spectrum of the light-emitting device which concerns on Examples 20-23 and the comparative example 3. FIG. It is a figure which shows the emission spectrum of the light-emitting device which concerns on Example 24 and Comparative Example 4. It is a figure which shows the emission spectrum of the light-emitting device which concerns on Example 25 and Comparative Example 5. FIG.

  Hereinafter, modes for carrying out the present invention will be described. However, the embodiment described below exemplifies 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 device. In this specification, the relationship between color names and chromaticity coordinates, the relationship between the wavelength range of light and the color name of monochromatic light, and the like are in accordance with JIS Z8110. Further, the content of each component in the composition means the total amount of the plurality of substances present in the composition unless there is a specific notice when there are a plurality of substances corresponding to each component in the composition. .

[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 emission peak wavelength in a range of 410 nm or more and 440 nm or less, and a fluorescent member 50. The fluorescent member 50 includes, as the phosphor 70, at least five of a first phosphor 71, a second phosphor 72, a third phosphor 73, a fourth phosphor 74, and a fifth phosphor 75. The first phosphor 71 includes an alkaline earth phosphate having an emission peak wavelength in the range of 430 nm to 500 nm, Cl in the composition, and 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, an alkaline earth aluminate activated by Eu, and a silicic acid activated by Eu having Ca, Mg and Cl in the composition. Contains at least one of the salts. The third phosphor 73 includes a rare earth aluminate having an emission peak wavelength in the range of 500 nm to 600 nm and activated with Ce. The fourth phosphor 74 has a light emission peak wavelength in the range of 610 nm or more and 650 nm or less, and includes silicon nitride activated by Eu having at least one of Sr and Ca and Al in the composition. The fifth phosphor 75 includes a fluorogermanate having an emission peak wavelength in the range of 650 nm to 670 nm and activated with Mn. The content of the first phosphor 71 with respect to the total amount of the phosphor 70 included in the phosphor member 50 is preferably 20% by mass or more and 80% by mass or less.

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

  Regarding the average color rendering index Ra, the CIE (International Lighting Commission) published guidelines for color rendering properties that fluorescent lamps should have in 1986. According to the guideline, a preferable average color rendering index Ra according to the place used is 60 to less than 80 in a factory where general work is performed, and houses, hotels, restaurants, stores, offices, schools, hospitals, and precision work are performed. It is 80 or more and less than 90 in factories and the like, and 90 or more in museums and the like where clinical examinations requiring high color rendering properties are required.

  Ra of the light emitting device 100 according to this embodiment is, for example, 80 or more, preferably 90 or more, and more preferably 95 or more. The special color rendering index R9 to R15 of the light emitting device 100 is, 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 total sum of the special color rendering index 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 from the light emitting device 100 is a color mixture of the light emitted from the light emitting element 10 and the fluorescence emitted from the first phosphor 71, the second phosphor 72, the third phosphor 73, the fourth phosphor 74, and the fifth phosphor 75. 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 The light included in the range of .25 to 0.40 and y = 0.25 to 0.40 can also be used. The correlated color temperature of the light emitted from the light emitting device 100 is, for example, 2000K or higher or 2500K or higher. The correlated color temperature is 7500K or less or 7000K 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 a range of 380 nm to 485 nm), and the gallium nitride compound semiconductor light emitting element 10 has an emission peak wavelength in a range of 410 nm to 440 nm, And 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 and the second lead 30 and the resin portion 42. Or it replaces with the resin part 42 and the molded object 40 can also be formed using the method already known by using ceramics as a material. The molded body 40 has a recess having a bottom surface and side surfaces, and the light emitting element 10 is placed on the bottom surface of the recess. The light emitting element 10 has a pair of positive and negative electrodes, and the pair of positive and negative electrodes are electrically connected to the first lead 20 and the second lead 30 through wires 60, respectively. The light emitting element 10 is covered with a fluorescent member 50. The fluorescent member 50 includes, for example, a first phosphor 71, a second phosphor 72, a third phosphor 73, a fourth phosphor 74, and a fifth phosphor 75 as a phosphor 70 that converts the wavelength of light from the light emitting element 10. It contains at least five kinds of phosphors and a resin.

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

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

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

First phosphor 71
The first phosphor 71 has a light emission peak wavelength in a range of 430 nm to 500 nm, and is a blue light-emitting phosphor containing an alkaline earth phosphate that has Cl as a composition and is activated by Eu. For example, the first phosphor 71 preferably has a composition represented by the following formula (1), and more preferably has a composition represented by the following formula (1 ′). Thereby, each light emission characteristic of the 1st fluorescent substance 71 demonstrated below can be obtained comparatively 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, not less than 360 nm and not more than 440 nm, and preferably not less than 370 nm and not more than 430 nm. It can be excited efficiently 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 to 500 nm, and preferably in the range of 440 nm to 480 nm. By setting it as such a range, the emission spectrum of the light emitting device 100 has an overlap between the emission spectrum of the first phosphor 71, the emission spectrum of the light emitting element 10, and the emission spectrum of the second phosphor 72, particularly in the blue region. Less. Furthermore, the emission spectrum of the light-emitting device 100 is made closer to the reference light source by using the emission spectrum of the first phosphor 71 and the emission spectrum of the light-emitting element 10 so that the emission intensity in the blue region, which was conventionally derived only from the light-emitting element, is closer to the reference light source. And the color rendering properties of the light emitting device 100 can be improved. The half width in the emission spectrum of the first phosphor 71 is, for example, 29 nm or more and 49 nm or less, and preferably 34 nm or more and 44 nm or less. By setting the half-value width in such a range, the color purity can be improved, the emission spectrum in the blue region can be brought close to the reference light source, and the color rendering properties 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 ratio of the first phosphor 71 with respect to the total phosphor amount in the phosphor member 50 (first phosphor amount / total phosphor amount; Hereinafter, simply referred to as “content ratio of the first phosphor 71”) is, for example, 20% by mass or more, preferably 25% by mass or more, and more preferably 40% by mass or more. Moreover, the content rate of the 1st fluorescent substance 71 is 80 mass% or less, for example, it is preferable that it is 75 mass% or less, and it is more preferable that it is 70 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 made closer to the reference light source, so that color rendering 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. 3 or more, 7 or less, preferably 0.5 or more and 6.5 or less, more preferably 0.6 or more and 6 or less, and still more preferably 1.8 or more and 6 or less. When the content ratio is within the above range, the light emission spectrum of the light emitting device 100 can be made closer to the reference light source, so that the color rendering can be further improved.

  In an 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 Luminescence peak intensity / emission peak intensity of the light-emitting element 10; hereinafter, also simply referred to as “emission peak intensity ratio”), for example, in the case of the light-emitting device 100 that emits light having a correlated color temperature of 2000K to 7500K. 15 or more, 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 light emitting device 100 can be brought closer to the reference light source, so that the color rendering can be further improved. Here, regarding 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 It is calculated considering the emission peak intensity of 71.

  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, and preferably 35% by mass or more. More preferably, it is at least mass%. Moreover, the content rate of the 1st fluorescent substance 71 is 80 mass% or less, for example, it is preferable that it is 77 mass% or less, and it is more preferable that it is 75 mass% or less. When the content ratio is within the above range, the emission spectrum of the light emitting device can be made closer to the reference light source, so that color rendering can be further improved.

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

  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, 0 It is preferably from 45 to 1.47, more preferably from 0.70 to 1.44. When the emission peak intensity 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 can be further improved.

  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, and preferably 45% by mass or more, 55 More preferably, it is at least mass%. Moreover, the content rate of the 1st fluorescent substance 71 is 80 mass% or less, for example, it is preferable that it is 78 mass% or less, and it is more preferable that it is 76 mass% or less. When the content ratio is within the above range, the light emission spectrum of the light emitting device 100 can be made closer to the reference light source, so that color rendering can be further improved.

  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 from 5 to 5.4, more preferably from 2 to 5.35. When the content ratio is within the above range, the light emission spectrum of the light emitting device 100 can be made closer to the reference light source, so that the color rendering can be further improved.

  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 0 It is preferably from 5 to 1.45, more preferably from 0.6 to 1.4. When the emission peak intensity 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 can be further improved.

  For example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 3500K or more and less than 4500K, the content of the first phosphor 71 is, for example, 20% by mass or more, and preferably 50% by mass or more. More preferably, it is at least mass%. Moreover, the content rate of the 1st fluorescent substance 71 is 75 mass% or less, for example, it is preferable that it is 70 mass% or less, and it is more preferable that it is 64 mass% or less. When the content ratio is within the above range, the light emission spectrum of the light emitting device 100 can be made closer to the reference light source, so that color rendering 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 from 8 to 4, and more preferably from 2.2 to 3.3. When the content ratio is within the above range, the light emission spectrum of the light emitting device 100 can be made closer to the reference light source, so that the color rendering can be further improved.

  For example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 3500K or more and less than 4500K, 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 0 It is preferably from 6 to 1.25, more preferably from 0.8 to 1.1. When the emission peak intensity 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 can be further improved.

  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, and preferably 35% by mass or more. More preferably, it is at least mass%. Moreover, the content rate of the 1st fluorescent substance 71 is 65 mass% or less, for example, it is preferable that it is 60 mass% or less, and it is more preferable that it is 55 mass% or less. When the content ratio is within the above range, the light emission spectrum of the light emitting device 100 can be made closer to the reference light source, so that color rendering can be further improved.

  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 to 4, and 1.5 to 3 Is preferably 0.5 or less, and more preferably 1.7 or more and 2.7 or less. When the content ratio is within the above range, the light emission spectrum of the light emitting device 100 can be made closer to the reference light source, so that the color rendering can be further improved.

  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, 0 It is preferably 0.5 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 light emitting device 100 can be brought closer to the reference light source, so that the color rendering 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, an alkaline earth aluminate activated by Eu, and a Ca activated by Eu having Ca, Mg and Cl in the composition. A phosphor emitting green light containing at least one of acid salts. The second phosphor 72 preferably contains at least the alkaline earth aluminate. The alkaline earth aluminate preferably has, for example, 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 light 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. More preferably, the Ca content of Ca, Sr and Ba is 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. It is more preferable.

The maximum excitation wavelength of the second phosphor 72 is, for example, not less than 270 nm and not more than 470 nm, and preferably not less than 370 nm and not more than 460 nm. It can be excited efficiently 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), the emission peak wavelength is, for example, not less than 400 nm and not more than 550 nm, and preferably not less than 460 nm and not more than 530 nm. The half width in the emission spectrum is, for example, from 58 nm to 78 nm, and preferably from 63 nm to 73 nm.
When the second phosphor 72 has a composition represented by the formula (2b), the emission peak wavelength is, for example, 510 nm or more and 540 nm or less, and preferably 520 nm or more and 530 nm or less. The half width in the emission spectrum is, for example, 50 nm to 75 nm, and preferably 58 nm to 68 nm.
By using at least one of the second phosphors 72, the color purity can be improved, the emission spectrum in the green region can be brought close to the reference light source, and the color rendering properties 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 phosphor amount in the phosphor member 50 (second phosphor amount / total phosphor amount; Hereinafter, simply referred to as “content ratio of second phosphor 72”) is 0.5 mass% or more, preferably 0.7 mass% or more, and more preferably 1 mass% or more. . Moreover, the content rate of the 2nd fluorescent substance 72 is 30 mass% or less, it is preferable that it is 20 mass% or less, and it is more preferable that it is 15 mass% or less.

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, and preferably 5% by mass or more. More preferably, it is at least mass%. Moreover, the content rate of the 2nd fluorescent substance 72 is 20 mass% or less, for example, it is preferable that it is 13 mass% or less, and it is more preferable that it is 11 mass% or less.
For example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 4500K or more and less than 5500K, 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 it is more preferable that it is 1 mass% or more. Moreover, the content rate of the 2nd fluorescent substance 72 is 4 mass% or less, for example, it is preferable that it is 3 mass% or less, and it is more preferable that it is 2 mass% or less.
For example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 3500K or more and less than 4500K, the content of the second phosphor 72 is, for example, 1.5% by mass or more, and preferably 2% by mass or more. 2.2% by mass or more is more preferable. Moreover, the content rate of the 2nd fluorescent substance 72 is 5 mass% or less, for example, it is preferable that it is 3.5 mass% or less, and it is more preferable that it is 3 mass% or less.
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, and preferably 2% by mass or more. 2.2% by mass or more is more preferable. Moreover, the content rate of the 2nd fluorescent substance 72 is 5 mass% or less, for example, it is preferable that it is 3.5 mass% or less, and it is more preferable that it is 3 mass% or less.
When the content ratio 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 can be further improved.

Third phosphor 73
The third phosphor 73 has a light emission peak wavelength in the range of 500 nm or more and 600 nm or less, and is a yellow light emitting phosphor containing a rare earth aluminate activated by Ce. For example, the third phosphor 73 preferably has a composition represented by the following formula (3), and more preferably has a composition represented by the following formula (3 ′). Thereby, each light emission characteristic of the 3rd fluorescent substance 73 demonstrated below can be obtained comparatively 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, not less than 220 nm and not more than 490 nm, and preferably not less than 430 nm and not more than 470 nm. It can be excited efficiently 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, not less than 480 nm and not more than 630 nm, and preferably not less than 500 nm and not more than 560 nm. By setting it as such a range, duplication with the emission spectrum of the 2nd fluorescent substance 72 can be decreased, the emission spectrum in a yellow area | region can be closely approached to a reference light source, and the color rendering property of the light-emitting device 10 can be improved more. it can. The full width at half maximum in the emission spectrum of the third phosphor 73 is, for example, not less than 95 nm and not more than 115 nm, and preferably not less than 100 nm and not more than 110 nm. By setting the half-value width in such a range, the color purity can be improved and the emission spectrum in the yellow region can be brought close to the reference light source, so that the color rendering properties 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 phosphor amount 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. Moreover, the content rate of the 3rd fluorescent substance 73 is 40 mass% or less, for example, it is preferable that it is 30 mass% or less, and it is more preferable that it is 25 mass% or less.

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, and preferably 10% by mass or more. More preferably, it is at least mass%. Moreover, the content rate of the 3rd fluorescent substance 73 is 40 mass% or less, for example, it is preferable that it is 30 mass% or less, and it is more preferable that it is 22 mass% or less.
For example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 4500K or more and less than 5500K, the content of the third phosphor 73 is, for example, 10% by mass or more, and preferably 12% by mass or more. More preferably, it is at least mass%. Moreover, the content rate of the 3rd fluorescent substance 73 is 45 mass% or less, for example, it is preferable that it is 30 mass% or less, and it is more preferable that it is 25 mass% or less.
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, and preferably 15% by mass or more. More preferably, it is 5% by mass or more. Moreover, the content rate of the 3rd fluorescent substance 73 is 50 mass% or less, for example, it is preferable that it is 35 mass% or less, and it is more preferable that it is 25 mass% or less.
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, and preferably 17.5% by mass or more. 20% by mass or more is more preferable. Moreover, the content rate of the 3rd fluorescent substance 73 is 40 mass% or less, for example, it is preferable that it is 30 mass% or less, and it is more preferable that it is 25 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 can be further improved.

Fourth phosphor 74
The fourth phosphor 74 has a light emission peak wavelength in the range of 610 nm or more and 650 nm or less, and has a composition containing at least one of Sr and Ca and Al and activated with Eu. It is. For example, the fourth phosphor 74 preferably has a composition represented by the following formula (4). Thereby, each light emission characteristic of the 4th fluorescent substance 74 demonstrated below can be obtained comparatively easily.
(Sr, Ca) AlSiN ₃ : Eu (4)

  When the fourth phosphor 74 has the composition represented by the formula (4), the fourth phosphor 74 includes at least one selected from the group consisting of Sr and Ca, but may include both Sr and Ca. Preferably, both Sr and Ca are included, and the Sr content of Sr and Ca is more preferably 0.8 mol% or more. Thereby, the emission peak wavelength of the fourth phosphor 74 can be set to a desired range.

  The emission peak wavelength of the fourth phosphor 74 is, for example, 620 nm or more and 650 nm or less, and preferably 630 nm or more and 645 nm or less. When the value is equal to or more than the lower limit, the emission spectrum in the red region is brought closer to the reference light source without a shortage of emission intensity between the emission peak wavelength of the fifth phosphor 75 and the emission peak wavelength of the fourth phosphor 74 described later. be able to. When the upper limit value is not exceeded, 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 obtained efficiently. Color rendering can be further improved. The half width in the emission spectrum of the fourth phosphor 74 is, for example, not less than 80 nm and not more than 100 nm, and preferably not less than 85 nm and not more than 95 nm. By setting the range of such a half-value width, since the overlap between the emission spectrum of the fourth phosphor 74 and the emission spectrum of the fifth phosphor 75 is reduced, the effect of the emission spectrum of the fifth phosphor 75 is efficient. The color rendering properties 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 fourth phosphor 74 to the total phosphor amount in the fluorescent member (fourth phosphor amount / total phosphor). Amount; hereinafter, 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. Moreover, the content rate of the 4th fluorescent substance 74 is 6 mass% or less, for example, it is preferable that it is 5 mass% or less, and it is more preferable that it is 4 mass% or less.

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, and preferably 1.5% by mass or more. More preferably, it is 2% by mass or more. Moreover, the content rate of the 4th fluorescent substance 74 is 6 mass% or less, for example, it is preferable that it is 4 mass% or less, and it is more preferable that it is 3.8 mass% or less.
For example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 4500K or more and less than 5500K, the content of the fourth phosphor 74 is, for example, 0.5% by mass or more, and preferably 1% by mass or more. More preferably, it is 1.5 mass% or more. Moreover, the content rate of the 4th fluorescent substance 74 is 3.5 mass% or less, for example, it is preferable that it is 3 mass% or less, and it is more preferable that it is 2.6 mass% or less.
For example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 3500K or more and less than 4500K, the content of the fourth phosphor 74 is, for example, 1% by mass or more, and preferably 1.5% by mass or more. 2.27% by mass or more is more preferable. Moreover, the content rate of the 4th fluorescent substance 74 is 4.8 mass% or less, for example, it is preferable that it is 3.5 mass% or less, and it is more preferable that it is 3 mass% or less.
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, and preferably 3% by mass or more. More preferably, it is 3.2 mass% or more. Moreover, the content rate of the 4th fluorescent substance 74 is 4.5 mass% or less, for example, it is preferable that it is 4 mass% or less, and it is more preferable that it is 3.5 mass% or less.
When the content ratio 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 can be further improved.

Fifth phosphor 75
The fifth phosphor has a peak emission wavelength in the range of 650 nm or more and 670 nm or less, and is a deep red emission phosphor containing a fluorogermanate activated by Mn. The fifth phosphor 75 is preferably at least one fluorogermanate 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 other phosphors emitting red light and is 650 nm or more. Therefore, the emission spectrum in the long wavelength region can be effectively brought close to the reference light source, and the color rendering properties of the light emitting device 100 can be further improved.
3.5MgO.0.5MgF ₂ .GeO ₂ : Mn (5a)
(Xs) 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 that <0.5, 0 <t <0.5, 0 ≦ u <1.5, and y + u <1.5. Further, M ^t in the general formula (5b) is at least one selected from the group consisting of Al, Ga and In.

In the formula (5b), 0.05 ≦ s ≦ 0.3 and 0.05 ≦ t <0.3 are preferably satisfied, whereby the luminance can be further improved. Furthermore, the fifth phosphor 75 preferably has a composition represented by the following formula (5b ′). Accordingly, the fifth phosphor 75 can be efficiently excited by light in a 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 half width in the emission spectrum of the fifth phosphor 75 is, for example, 45 nm or less, and preferably 40 nm or less. By setting the half-value width in such a range, the color purity can be improved, the emission spectrum in the red region can be brought close to the reference light source, and the color rendering properties of the light emitting device 100 can be further improved. The emission spectrum of the fifth phosphor 75 has an average emission intensity in the range of 600 nm or more and 620 nm or less, for example, 20% or less, preferably 10% or less, assuming that the maximum emission intensity is 100%. Within the above range, the emission spectrum of the fifth phosphor 75, which will be described later, is less likely to overlap 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. Color rendering 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 phosphor amount in the fluorescent member 50 (fifth phosphor amount / total phosphor amount; Hereinafter, it is 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. Moreover, the content rate of the 5th fluorescent substance 75 is 40 mass% or less, for example, it is preferable that it is 35 mass% or less, and it is more preferable that it is 30 mass% or less.

For example, in the case of the light emitting device 100 that emits light having a correlated color temperature of 5500K to 7500K, the content of the fifth phosphor 75 is, for example, 1% by mass or more, and preferably 2% by mass or more. More preferably, it is at least mass%. Moreover, the content rate of the 5th fluorescent substance 75 is 12 mass% or less, for example, it is preferable that it is 6 mass% or less, and it is more preferable that it is 5.5 mass% or less.
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, and preferably 5% by mass or more. More preferably, it is at least mass%. Moreover, the content rate of the 5th fluorescent substance 75 is 30 mass% or less, for example, it is preferable that it is 20 mass% or less, and it is more preferable that it is 15 mass% or less.
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, and preferably 8% by mass or more. More preferably, it is at least mass%. Moreover, the content rate of the 5th fluorescent substance 75 is 28 mass% or less, for example, it is preferable that it is 20 mass% or less, and it is more preferable that it is 16 mass% or less.
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, and preferably 18% by mass or more. More preferably, it is at least mass%. Moreover, the content rate of the 5th fluorescent substance 75 is 45 mass% or less, for example, it is preferable that it is 40 mass% or less, and it is more preferable that it is 30 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 can be further improved.

The fluorescent member 50 may include other phosphors other than the first phosphor 71 to the fifth phosphor 75 as necessary. Other phosphors include 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 includes other phosphors, the content is appropriately adjusted so that the light emission characteristics according to the present invention can be obtained. The content of other phosphors is, for example, 2% by mass or less, and preferably 1% by mass or less, based on the total phosphor amount.

(resin)
As resin which comprises the fluorescent member 50, a thermoplastic resin and a thermosetting resin are mentioned. Specific examples of the thermosetting resin include modified silicone resins such as epoxy resins, silicone resins, and epoxy-modified silicone resins.

(Other ingredients)
The fluorescent member 50 may include other components as necessary in addition to the phosphor 70 and the resin. Examples of other components include fillers such as silica, barium titanate, titanium oxide, and aluminum oxide, light stabilizers, and colorants. When the fluorescent member contains other components, the content thereof is not particularly limited and can be appropriately selected depending on the purpose and the like. For example, when the filler is included as the other component, the content thereof can be 0.01 to 20 parts by mass with respect to 100 parts by mass of the resin.

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

(Phosphor 70)
Prior to the manufacture of the light emitting device 100, the following first phosphor 71 to fifth phosphor 75 were prepared.
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 near 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 near 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 near 544 nm was prepared.
As the fourth phosphor 74, a red-emitting nitride phosphor having a composition represented by (Sr, Ca) AlSiN ₃ : Eu and having an emission peak wavelength near 635 nm (hereinafter also referred to as “SCASN”). Got ready.
A fifth phosphor _{75, 3.4MgO · 0.1Sc 2 O 3} · 0.5MgF 2 · 0.885GeO 2 · 0.1Ga 2 O 3: having a composition represented by 0.015Mn, the emission peak wavelength A phosphor (hereinafter also referred to as “MGF”) having a deep red emission around 658 nm was prepared.

(Light emitting element 10)
As the light emitting element 10, a blue-violet light emitting LED having an emission peak wavelength of 430 nm was prepared.

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

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

  The content of the first phosphor 71 (CCA) with respect to the total phosphor amount is 33.3% on a mass basis, and the content of each of the other phosphors with respect to the total phosphor amount is a value shown in Table 1 below, and correlation Phosphor 70 blended so that the color temperature is around 6500K was added to the silicone resin, mixed and dispersed, and then defoamed to obtain a phosphor-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 poured and filled on the light emitting element 10, and further heated to cure the resin composition. The light emitting device 100 of Example 1 was manufactured through such steps.

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

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

  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, Examples 1 to 7 include the first phosphor 71, so that Ra is larger than that of Comparative Example 1 that does not include the first phosphor 71. Further, Examples 1 to 7 could all have a high numerical value of 60 or more in R9 to R15.
On the other hand, in the comparative example 1 which does not contain the 1st fluorescent substance 71, Ra was smaller than any Example, R12 was 38 and was quite low compared with the Example.

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

  2 shows an emission spectrum of the light emitting device 100 according to Comparative Example 1 and Examples 1 to 3, and FIG. 3 shows an emission spectrum of the light emitting device 100 according to Comparative Example 1 and Examples 4 to 7, respectively. It is the figure which normalized and compared on the basis of intensity | strength. The emission spectra in 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. In Examples 4, 5, 6 and 7, as shown in Table 2, the value of R12 is 90 or more, and the value of Rt is 650 or more, which indicates that the color rendering properties are particularly excellent. .

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

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

  Regarding the evaluation results of the light emitting devices 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, Examples 8 to 15 include the first phosphor 71, so that Ra is larger than Comparative Example 2 that does not include the first phosphor 71. In Examples 8 to 15, all of R9 to R15 could have a high numerical value of 60 or more.
On the other hand, in the comparative example 2 which does not contain the 1st fluorescent substance 71, Ra was smaller than any Example, R12 was 35 and was quite low compared with the Example.

  In Examples 8 to 15 and Comparative Example 2, as shown in Table 3, the correlated color temperature was in the range of 4500K to 5500K. 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 phosphor amount is 55% by mass or more and 80% by mass or less. The content ratio of the first phosphor 71 to the phosphor 73 is included in the range of 2.4 to 5.5. 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. It turns out that it is excellent.

  4 shows an emission spectrum of the light emitting device 100 according to Comparative Example 2 and Examples 8 to 11, and FIG. 5 shows an emission spectrum of the light emitting device 100 according to Comparative Example 2 and Examples 12 to 15, respectively. It is the figure which normalized and compared on the basis of intensity | 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 light emitting element 10 in the emission spectrum is 0.6 or more and 1.5 or less. It 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 properties are It turns out that it is particularly excellent.

(Examples 16 to 23)
The light emitting devices 100 of Examples 16 to 23 were changed 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 4000K. Produced.

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

  Regarding the evaluation results of the light emitting devices 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, Examples 16 to 23 include the first phosphor 71, so that Ra is larger than that of Comparative Example 3 that does not include the first phosphor 71. In addition, Examples 16 to 23 could have a high numerical value of 60 or more in R9 to R15.
On the other hand, in Comparative Example 3 not including the first phosphor 71, Ra was smaller than that of the example and R12 was 44, which was considerably lower than that of the example.

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

  6 shows the emission spectrum of the light emitting device 100 according to Comparative Example 3 and Examples 16 to 19, and FIG. 7 shows the emission spectrum of the light emitting device 100 according to Comparative Example 3 and Examples 20 to 23. It is the figure which normalized and compared on the basis of intensity | strength. The emission spectra in 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. As shown in Table 6, these Examples 19, 20, and 21 have a R12 value of 97 or more and a Rt value of 680 or more, indicating that the color rendering properties are particularly excellent.

(Example 24)
The light emitting device 100 of Example 24 was fabricated 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)
Without using the first phosphor 71 (CCA) as the phosphor 70, the second phosphor 72 (SAE), the third phosphor 73 (YAG), the fourth phosphor 74 (SCASN), and the fifth The light emitting device 100 of Comparative Example 4 was fabricated in the same manner as in Example 1 except that the phosphor 75 (MGF) was used in combination and the correlated color temperature was adjusted to around 3000K.

(Example 25)
The light emission of Example 25 was performed 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 amount of the phosphor was changed so that the correlated color temperature was adjusted to around 2700 K. Device 100 was made.

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

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

From Tables 7 and 8, Examples 24 and 25 include the first phosphor 71, so that Ra is improved over Comparative Examples 4 and 5 that do not include the first phosphor 71. Moreover, Examples 24 and 25 were able to have a high numerical value of 90 or more in R9 to R15.
On the other hand, in Comparative Example 4 that did not include the first phosphor 71, Ra was smaller than Example 24, R12 was 51, and was considerably smaller than Example 24. Similarly, in Comparative Example 5 not including the first phosphor 71, Ra was smaller than Example 25, R12 was 59, and 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 2000K to 3500K. In Examples 24 and 25, as shown in Table 7, the content ratio of the first phosphor 71 with respect to the total phosphor amount is 40% by mass to 55% by mass, and the first phosphor with respect to the third phosphor 73 The content ratio of 71 is included in the range of 1.9 to 2.5. In Examples 24 and 25, as shown in Table 8, the value of R12 is 90 or more, and the value of Rt is 680 or more, and the color rendering properties are superior to those of Comparative Examples 4 and 5. I understand that.

  FIG. 8 shows the emission spectrum of the light emitting device 100 according to Comparative Example 4 and Example 24, and FIG. 9 shows 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, respectively. FIG. 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 light emitting element 10 in the emission spectrum is 0.8 or more and 1.1 or less. In Examples 24 and 25, as shown in Table 8, the value of R12 is 90 or more, and the value of Rt is 680 or more, and the color rendering properties are superior to those of Comparative Examples 4 and 5. I understand that.

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

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

Claims (20)

A light emitting element having a light emission peak wavelength in a range of 410 nm or more and 440 nm or less, and a fluorescent member,
The fluorescent member is a phosphor,
A first phosphor comprising an alkaline earth phosphate having an emission peak wavelength in the range of 430 nm or more and 500 nm or less, having a composition of Cl and being activated by Eu;
A light emitting peak wavelength in the range of 440 nm to 550 nm and including at least one of an alkaline earth aluminate activated by Eu and a silicate activated by Eu having Ca, Mg and Cl in the composition. Two phosphors,
A third phosphor comprising a rare earth aluminate having an emission peak wavelength in a range of 500 nm to 600 nm and activated by Ce;
A fourth phosphor containing silicon nitride having an emission peak wavelength in the range of 610 nm to 650 nm and having a composition containing at least one of Sr and Ca and Al and activated by Eu;
Has an emission peak wavelength 670nm or less in the range above 650 nm, viewed contains a fifth phosphor comprising fluoroelastomer jar money bets that are activated with Mn, and
The light-emitting device whose content rate of said 1st fluorescent substance is 20 to 80 mass% with respect to the total amount of the said fluorescent substance . 2. The light emitting device according to claim 1, wherein the light emitting device emits light having a correlated color temperature of 5500 K or more and 7500 K or less, and an emission peak intensity ratio of the first phosphor to the light emitting element in an emission spectrum is 0.4 or more and 1.5 or less. . 2. The light emitting device according to claim 1, wherein the light emitting device emits light having a correlated color temperature of 4500 K or more and less than 5500 K, and an emission peak intensity ratio of the first phosphor to the light emitting element in an emission spectrum is 0.4 or more and 1.5 or less. . 2. The light emitting device according to claim 1, wherein the light emitting device emits light having a correlated color temperature of 3500 K or more and less than 4500 K, and an emission peak intensity ratio of the first phosphor to the light emitting element in an emission spectrum is 0.3 or more and 1.3 or less. . 2. The light emitting device according to claim 1, wherein the light emitting device emits light having a correlated color temperature of 2500 K or more and less than 3500 K, and an emission peak intensity ratio of the first phosphor to the light emitting element in an emission spectrum is 0.2 or more and 1.4 or less. . Emits light having a correlated color temperature of 5500K to 7500K,
The light emitting device according to claim 1, wherein the content of the first phosphor with respect to the total amount is 30% by mass or more and 80% by mass or less. The light emitting device according to claim 6 , wherein a content ratio of the first phosphor to the third phosphor is 0.9 or more and 6 or less. Emitting light whose correlated color temperature is 4500K or more and less than 5500K,
The light emitting device according to claim 1, wherein the content of the first phosphor with respect to the total amount is 30% by mass or more and 80% by mass or less. The light emitting device according to claim 8 , wherein a content ratio of the first phosphor to the third phosphor is 0.8 or more and 5.5 or less. Emitting light whose correlated color temperature is 3500K or more and less than 4500K,
2. The light emitting device according to claim 1, wherein the content of the first phosphor with respect to the total amount is 20 mass% or more and 75 mass% or less. The light emitting device according to claim 10 , wherein a content ratio of the first phosphor to the third phosphor is 0.6 or more and 4.2 or less. Emitting light whose correlated color temperature is 2500 K or more and less than 3500 K;
2. The light emitting device according to claim 1, wherein the content of the first phosphor with respect to the total amount is 40 mass% or more and 55 mass% or less. The light emitting device according to claim 12 , wherein a content ratio of the first phosphor to the third phosphor is 1.9 or more and 2.5 or less. The light emitting device according to any one of claims 1 to 13 , wherein the first phosphor includes an alkaline earth phosphate having a composition represented by the following formula (1).
(Ca, Sr, Ba) ₅ (PO ₄ ) ₃ (Cl, Br): Eu (1) The second phosphor, claim 1 comprising at least one silicate having a composition represented by the following formula (2a) an alkaline earth aluminate and the following formula having a composition represented by (2b) 14 of The light-emitting device of any one of Claims.
_{(Sr, Ca, Ba) 4} Al 14 O 25: Eu (2a)
(Ca, Sr, Ba) ₈ MgSi ₄ O ₁₆ (F, Cl, Br) ₂ : Eu (2b) The light emitting device according to any one of claims 1 to 15 , wherein the third phosphor includes a rare earth aluminate having a composition represented by the following formula (3).
(Y, Lu, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce (3) The light emitting device according to any one of claims 1 to 16 , wherein the fourth phosphor includes silicon nitride having a composition represented by the following formula (4).
(Sr, Ca) AlSiN ₃ : Eu (4) The light emitting device according to any one of claims 1 to 17 , wherein the fifth phosphor includes at least one fluorogermanate having a composition represented by the following formula (5a) or (5b).
3.5MgO.0.5MgF ₂ .GeO ₂ : Mn (5a)
(Xs) MgO. (S / 2) Sc ₂ O ₃ .yMgF ₂ .uCaF _2. (1-t) GeO _2. (T / 2) M ^t ₂ O ₃ : zMn (5b)
(Wherein, ^{M t} is at least one selected from the group consisting of Al, Ga,及beauty In, x, y, z, s, each t and u, 2 ≦ x ≦ 4,0 < y < 1.5, 0 <z <0.05, 0 ≦ s <0.5, 0 <t <0.5, and 0 ≦ u <1.5.) The light emitting device according to any one of claims 1 to 18 , wherein the special color rendering index R12 is 60 or more. The light emitting device according to any one of claims 1 to 19 , wherein a sum of the special color rendering index numbers R9 to R15 is 600 or more.