JP2018156966A - Light-emitting device and illumination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-emitting device and an illumination device capable of arbitrarily setting a chromaticity point of outgoing light in a given region of chromaticity coordinates by controlling only two types of light-emitting elements.SOLUTION: A light emitting device 1 includes, on a substrate 2, a plurality of first light-emitting elements 3a, a plurality of second light-emitting elements 3b, and an encapsulation material 4 encapsulating the first light-emitting elements 3a and the second light-emitting elements 3b. The first light-emitting element 3a emits light at a first light-emission peak wavelength, while the second light-emitting element 3b emits light at a second light emission peak wavelength. A first phosphor 6a and a second phosphor 6b are encapsulated in the encapsulation material 4. The first phosphor 6a shows higher excitation efficiency at the first light emission peak wavelength than the excitation efficiency at the second light emission peak wavelength. A reduction rate from the excitation efficiency at the first light emission peak wavelength to the excitation efficiency at the second light emission peak wavelength is smaller in the second phosphor 6b than in the first phosphor 6a.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a light emitting device having a structure in which a light emitting element is arranged on a substrate, and an illumination device using the same.

  2. Description of the Related Art Conventionally, in a light emitting device using a light emitting element such as a light emitting diode (LED: Light Emitting Diode), a device that performs color adjustment using two types of light emitting units having different chromaticities is known (for example, patents). Reference 1). Hereinafter, the light emitting device of the conventional example (Patent Document 1) will be briefly described with reference to FIG.

  FIG. 9 is a schematic view of a light emitting device according to a conventional example. A light emitting module 500 according to Patent Document 1 includes a plurality of light emitting units 503a having LEDs 504a and wavelength conversion members 505a, and a plurality of light emitting units 503b having LEDs 504b and wavelength conversion members 505b. The light emitting portions 503a and 503b are substantially linear, and are alternately arranged in the square light emitting region 500a. The light emitting portions 503a and 503b are connected to the electrodes 501 and 502 by wirings 501a and 502a.

  The light emitting units 503a and 503b differ in their chromaticity, and according to the light emitting module 500, it is possible to adjust the color between the chromaticities of the light emitting units 503a and 503b.

JP 2014-143307 A

  However, in the configuration as in Patent Document 1, only the toning on the line segment between the chromaticity points of the light emitting units 503a and 503b can be performed in the chromaticity coordinates, and the light of the coordinates deviating from the line segment is adjusted. Can not do it. In such a case, in order to perform a non-linear color tone such as a color tone along a black body locus, for example, one or more light emitting units must be added to control at least three light emitting units.

  The present invention has been made in view of the above problems. The object is to provide a light-emitting device and an illumination device that can arbitrarily set the chromaticity point of emitted light within a fixed region of chromaticity coordinates by controlling only two types of light-emitting elements.

  To achieve the above object, a light-emitting device according to the present invention includes a substrate, a first light-emitting element group having a plurality of first light-emitting elements disposed on the substrate and emitting light at a first emission peak wavelength, A second light-emitting element group having a plurality of second light-emitting elements that are disposed on the substrate and emits light at a second emission peak wavelength; and the light-transmitting first light-emitting element group and the second light-emitting element group And a sealing material for sealing. The sealing material encloses a first phosphor that emits fluorescence at a first fluorescence peak wavelength and a second phosphor that emits fluorescence at a second fluorescence peak wavelength. The first phosphor has higher excitation efficiency at the first emission peak wavelength than excitation efficiency at the second emission peak wavelength, and the second phosphor has the first emission peak wavelength. The reduction rate from the excitation efficiency to the excitation efficiency at the second emission peak wavelength is smaller than the reduction rate of the first phosphor.

  In addition, an illumination device according to the present invention includes a control unit that controls the emission intensity of each of the above-described light emitting device and the first light emitting element group and the second light emitting element group.

  In the light emitting device according to the present invention, the rate of decrease in excitation efficiency at the first emission peak wavelength and the second emission peak wavelength is smaller in the second phosphor than in the first phosphor. Therefore, by adjusting the emission intensity of the first light emitting element group and the second light emitting element group, it is possible to arbitrarily set the chromaticity point of the emitted light within a certain region of the chromaticity coordinates.

  Also in the illumination device according to the present invention, the rate of decrease in excitation efficiency at the first emission peak wavelength and the second emission peak wavelength is smaller for the second phosphor than for the first phosphor. Therefore, by adjusting the emission intensity of the first light emitting element group and the second light emitting element group, it is possible to arbitrarily set the chromaticity point of the emitted light within a certain region of the chromaticity coordinates.

Schematic diagram of the light-emitting device according to Embodiment 1 FIG. 1 is a schematic cross-sectional view of the light-emitting device according to Embodiment 1 taken along line AA in FIG. The graph showing the wavelength change of the excitation efficiency of two types of fluorescent substance concerning Embodiment 1 Graph representing chromaticity coordinates of emitted light of the light-emitting device according to Embodiment 1 Schematic diagram of a modification of the light emitting device according to Embodiment 1 Schematic cross-sectional view of a lighting device including the light-emitting device according to Embodiment 1 Schematic diagram of a light-emitting device according to Embodiment 2 Schematic cross-sectional view of the light-emitting device according to Embodiment 2 Schematic diagram of a conventional light emitting device

  Embodiments of the present invention will be described. Hereinafter, for the sake of simplicity of explanation, a light emitting device that emits white light and a lighting device will be described as an example. Of course, the present invention is not limited to a light emitting device or the like that emits white light, and can be applied to various emission colors such as yellow and green by appropriately selecting a phosphor or a light emitting element. .

  Moreover, although demonstrated using LED as a light emitting element, a light emitting element is not limited to LED. For example, various light emitting elements such as a semiconductor light emitting element used for a semiconductor laser, an EL element such as an organic EL (EL), an inorganic EL, or the like can be used.

(Embodiment 1)
Hereinafter, Embodiment 1 according to the present invention will be described mainly with reference to FIGS. FIG. 1 is a schematic diagram of a light emitting device according to Embodiment 1. FIG. 2 is a schematic cross-sectional view taken along the line AA of FIG. 1 of the light-emitting device according to Embodiment 1. FIG. FIG. 3 is a graph showing the wavelength change of the excitation efficiency of the two types of phosphors according to the first embodiment. FIG. 4 is a graph showing the chromaticity coordinates of the emitted light of the light emitting device according to the first embodiment.

  Here, the excitation efficiency in FIG. 3 is a normalized excitation efficiency. These excitation efficiencies are standardized so that the maximum value of the excitation efficiencies in the range of excitation wavelengths from 350 nm to 500 nm is 1. Hereinafter, “excitation efficiency” in the specification refers to normalized excitation efficiency.

[Configuration of light emitting device]
The light emitting device 1 according to the first embodiment is a so-called chip-on-board LED module in which a plurality of first light emitting elements 3a and a plurality of second light emitting elements 3b are directly mounted on a substrate 2. In the first embodiment, a first light emitting element group 5a composed of a plurality of first light emitting elements 3a and a second light emitting element group 5b composed of a plurality of second light emitting elements 3b are directly mounted on the substrate 2. It is sealed with the sealing material 4. The sealing material 4 encloses two types of phosphors, a first phosphor 6a and a second phosphor 6b.

  The first light emitting element group 5a includes a plurality of first light emitting elements 3a connected to the wiring part 12 by bonding wires (not shown). Similarly, the second light emitting element group 5b includes a plurality of second light emitting elements 3b connected to the wiring portion 12 by bonding wires. The wiring part 12 is connected to three power supply terminals 10a, 10b, and 10c, and the power supply terminals 10a, 10b, and 10c are connected to an external power source. Further, the wiring part 12 is covered with a wiring cover part 11.

[substrate]
The substrate 2 includes the first light emitting element 3a, the second light emitting element 3b, the sealing material 4, the wiring part 12, the wiring cover part 11, and the three power supply terminals 10a, 10b, and 10c. Is a plate material. In the first embodiment, the shape of the substrate 2 is a rectangle, but is not limited to a rectangle, and various shapes such as a circle and a pentagon can be adopted.

  As a material constituting the substrate 2, various materials such as ceramic, metal, and resin can be used. For example, as the ceramic substrate, aluminum oxide (alumina), aluminum nitride, or the like can be used. As the metal substrate, an aluminum alloy, a copper alloy, or the like whose surface is insulated can be used. As the resin substrate, an epoxy substrate made of glass fiber and an epoxy resin can be used.

  Further, as the substrate 2, a substrate having transparency may be adopted. As the transparent substrate, for example, a transparent glass substrate made of glass, a sapphire substrate made of sapphire, or the like can be used.

  As described above, various materials can be used as the material of the substrate 2, but it is preferable to use an alumina substrate. This is because alumina is white and has a high light reflectance, so that the light emitted from the first light emitting element 3a and the second light emitting element 3b can be reflected on the surface, and the light extraction efficiency of the light emitting device 1 is improved.

  As a material of the wiring part 12, silver, a copper alloy, and other metals can be adopted. As shown by a dotted line in FIG. 1, the wiring portion 12 is composed of three parts: a wiring 12 a connected to the power feeding terminal 10 a, a wiring 12 b connected to the power feeding terminal 10 b, and a wiring 12 c connected to the power feeding terminal 10 c. And has a substantially circular shape. Each wiring 12a, 12b, 12c is not electrically or physically connected. In addition, the shape of the wiring part 12 is not limited to a circle, and various shapes such as a rectangle can be adopted.

  The wiring cover portion 11 is made of an insulating material and is provided on the substrate 2 so as to cover the wiring portion 12. Moreover, the wiring cover part 11 is also used to block the sealing material 4 before curing.

  As a material constituting the wiring cover portion 11, an insulating resin, ceramic, or the like can be used. For example, as the resin, an insulating thermosetting resin or thermoplastic resin can be used, and specifically, a silicone resin, a phenol resin, an epoxy resin, polyphthalamide, or the like.

Moreover, as a material which comprises the wiring cover part 11, it is preferable that it is resin which has a white pigment etc. This is because the light reflectance of the wiring cover portion 11 can be increased, and the light extraction efficiency of the light emitting device 1 is improved. In addition, a resin containing particles such as TiO ₂ , Al ₂ O ₃ , ZrO ₂ , and MgO can be used. This is because the light reflectance of the wiring cover portion 11 can be increased and the light extraction efficiency of the light emitting device 1 is improved, as in the case of using a resin having a white pigment or the like.

  The power supply terminals 10a, 10b, and 10c are used to supply power to the first light emitting element group 5a and the second light emitting element group 5b, and are electrically connected to an external power source. As a material constituting the power supply terminals 10a, 10b, and 10c, a metal material such as gold, silver, or a copper alloy can be used.

  In the first embodiment, the first light emitting element group 5a is connected to an external power source through the power supply terminals 10a and 10b. In addition, the second light emitting element group 5b is connected to an external power source through power supply terminals 10a and 10c. In this way, by changing the connection route with the external power source between the first light emitting element group 5a and the second light emitting element group 5b, the light emission intensity and the first light emitting element group 5a and The light emission intensity of the two light emitting element groups 5b can be controlled separately.

  In the first embodiment, as described above, the connection route between the first light emitting element group 5a and the second light emitting element group 5b is changed using the three power supply terminals 10a, 10b, and 10c. Two power supply terminals may be used. For example, when adding one additional power supply terminal, the first light emitting element group 5a is connected to an external power source through the power supply terminals 10a and 10b, and the second light emitting element group 5b is connected to the power supply terminal 10c and the additional power supply terminal. It is good also as a structure connected with an external power supply.

[First light emitting element]
As described above, various light-emitting elements can be applied as the first light-emitting element 3a. The case where LEDs are used will be described. In the first embodiment, a case where a blue LED is used will be described. As the blue LED used for the first light emitting element 3a, for example, an InGaN-based LED having an emission spectrum peak wavelength (first emission peak wavelength) of 430 nm or more and 480 nm or less can be used. Of course, the emission color of the first light emitting element 3a is not limited to blue, and an appropriate color can be adopted according to the toning range of the emitted light in the entire light emitting device 1.

  The plurality of first light emitting elements 3 a are directly installed on the substrate 2 in a region surrounded by the wiring cover portion 11. The first light emitting element 3a installed on the substrate 2 is connected to the wirings 12a and 12b by bonding wires. The first light emitting element group 5a is composed of a plurality of first light emitting elements 3a connected by the wirings 12a and 12b as described above. Since the wirings 12a and 12b are respectively connected to the power supply terminals 10a and 10b, power is supplied from the external power source to the first light emitting element group 5a via the power supply terminals 10a and 10b and the wirings 12a and 12b.

  As a connection method of the first light emitting elements 3a, a connection method is adopted in which a plurality of first light emitting elements 3a are connected in series with bonding wires to form a first light emitting element array (not shown). May be. In the first light emitting element array, the wiring 12a to the wiring 12b are further connected by a bonding wire. Since the wirings 12a and 12b are connected to the power supply terminals 10a and 10b, respectively, power is supplied from the external power source to the first light emitting element array.

Here, the number of the first light emitting element rows can be appropriately set as follows. For example, one first light emitting element row may be formed by connecting all the first light emitting elements 3a in series. Further, a plurality of first light emitting elements 3a may be connected in series by connecting some of the plurality of first light emitting elements 3a in series, so that the plurality of first light emitting element rows may be connected in parallel to the wirings 12a and 12b.

  Note that the first light-emitting element array is not formed, and the plurality of first light-emitting elements 3a can be individually connected to the wirings 12a and 12b by bonding wires.

[Second light emitting element]
As described above, various light-emitting elements can be applied as the second light-emitting element 3b, but the case where LEDs are used will be described. In the first embodiment, a case where an ultraviolet LED having light emission in the ultraviolet region is used will be described. For example, as the ultraviolet LED, an InGaN-based LED to which Al is added and whose peak wavelength of the emission spectrum (second emission peak wavelength) is 350 nm or more and 400 nm or less can be used. Of course, the emission wavelength of the second light emitting element 3b is not limited to the ultraviolet region, and an appropriate wavelength can be adopted according to the toning range of the emitted light in the entire light emitting device 1.

  A plurality of second light emitting elements 3 b are directly installed on the substrate 2 in a region surrounded by the wiring cover portion 11. The second light emitting element 3b installed on the substrate 2 is connected to the wirings 12a and 12c by bonding wires. The second light emitting element group 5b includes a plurality of second light emitting elements 3b connected by the wirings 12a and 12c as described above. Since the wirings 12a and 12c are connected to the power supply terminals 10a and 10c, respectively, power is supplied from the external power source to the second light emitting element group 5b via the power supply terminals 10a and 10c and the wirings 12a and 12c.

  As a connection method of the second light emitting elements 3b, a connection method is adopted in which a plurality of second light emitting elements 3b are connected in series with bonding wires to form a second light emitting element array (not shown). May be. In the second light emitting element array, the wiring 12a to the wiring 12c are further connected by a bonding wire. Since the wirings 12a and 12c are connected to the power supply terminals 10a and 10c, respectively, power is supplied from the external power source to the second light emitting element array.

  Here, the number of the second light emitting element rows can be appropriately set as follows. For example, one second light emitting element array may be formed by connecting all the second light emitting elements 3b in series. In addition, a plurality of second light emitting element 3b may be connected to the wirings 12a and 12c in parallel by connecting some of the plurality of second light emitting elements 3b in series.

  Note that the second light emitting element array is not formed, and the plurality of second light emitting elements 3b can be individually connected to the wirings 12a and 12c by bonding wires.

[Encapsulant]
The sealing material 4 is a material for sealing the first light emitting element 3a, the second light emitting element 3b, and the bonding wire. Further, a first phosphor 6a and a second phosphor 6b, which will be described later, are sealed in a state of being dispersed inside the sealing material 4. Since the sealing material 4 is cured while being damped to the wiring cover portion 11, the sealing material 4 has a shape that matches the shape of the wiring cover portion 11. For example, in Embodiment 1, it is circular. If the wiring cover portion 11 is rectangular, the shape of the sealing material 4 can be appropriately designed according to the shape of the wiring cover portion 11 such that the sealing material 4 is also rectangular.

  In the first embodiment, the upper surface of the sealing material 4 has substantially the same height as the upper surface of the wiring cover portion 11, but the height of the upper surface of the sealing material 4 is not limited to this. For example, it may be lower than the height of the wiring cover part 11. Further, the upper surface of the sealing material 4 may be an upward convex curved surface, so that it may protrude above the wiring cover portion 11.

  However, it is essential that the first light-emitting element 3a and the second light-emitting element 3b have such a height that can be completely sealed. If the first light-emitting element 3a and the second light-emitting element 3b are not completely covered, the first phosphor 6a and the second phosphor 6b are efficiently attached by the light emission from the first light-emitting element 3a and the second light-emitting element 3b. This is because it cannot be excited. Moreover, it is because the first light emitting element 3a, the second light emitting element 3b, and the bonding wire can be protected from dust, moisture, external force, and the like by completely covering with the sealing material 4.

  As a material constituting the sealing material 4, a light transmissive resin can be used. As the light transmissive resin, a silicone resin can be used. For example, an epoxy resin or a urea resin may be used.

[First phosphor]
The first phosphor 6a is a phosphor in which the excitation efficiency in the light emission of the first light emitting element 3a is higher than the excitation efficiency in the light emission of the second light emitting element 3b. For example, when white light is obtained as in Embodiment 1, a phosphor that emits green light can be employed. The color of the fluorescent light emitted from the first phosphor 6a is not limited to green, and can be appropriately changed to yellow, blue, or the like according to the light emission toning range of the entire light emitting device 1.

In the first embodiment, for example, an yttrium, aluminum, garnet (YAG) phosphor or the like can be used as the green phosphor. More specifically, a phosphor having a fluorescence spectrum peak wavelength (first fluorescence peak wavelength) of 530 nm or more and 560 nm or less and a composition of Y ₃ GaAl (AlO ₄ ) ₃ : Ce ³⁺ can be used. . Of course, an organic phosphor or the like can be used as the first phosphor 6a. The reason why an inorganic phosphor such as a YAG-based phosphor is employed in the first embodiment is that its durability is higher than that of an organic phosphor.

  Here, the excitation efficiency at the first emission peak wavelength (430 nm or more and 480 nm or less) is defined as excitation efficiency A, and the excitation efficiency at the second emission peak wavelength (350 nm or more and 400 nm or less) is defined as excitation efficiency B.

  The excitation efficiency A of the first phosphor 6a is higher than the excitation efficiency B of the first phosphor 6a. For example, the reduction rate from the excitation efficiency A to the excitation efficiency B of the first phosphor 6a is preferably 50% or more. Further, this reduction rate may be 70% or more, and the first phosphor 6a is reduced so that the difference from the reduction rate from the excitation efficiency A to the excitation efficiency B of the second phosphor 6b described later becomes large. The rate can be designed appropriately. In the YAG phosphor used in the first embodiment, as shown in FIG. 3, the reduction rate from the excitation efficiency A to the excitation efficiency B is approximately 80%.

Here, the calculation formula of the reduction rate is shown in the following formula 1. In Equation 1, E _A is the excitation efficiency of the first emission peak wavelength, the E _B the excitation efficiency of the second peak emission wavelength, represents respectively.

なお、図２は第１蛍光体６ａの大きさを模式的に記載しており、実際には平均粒径が５μｍ以上、２０μｍ以下の大きさのもの等を採用することができる。

FIG. 2 schematically shows the size of the first phosphor 6a. In actuality, a phosphor having an average particle size of 5 μm or more and 20 μm or less can be employed.

[Second phosphor]
As the second phosphor 6b, the rate of decrease from the excitation efficiency A to the excitation efficiency B is the first phosphor 6b.
It is a phosphor that is smaller than the rate of decrease of excitation efficiency A from excitation efficiency B to a. For example, when white light is obtained as in Embodiment 1, a phosphor that emits red light can be employed. The color of the fluorescent light emitted from the second phosphor 6b is not limited to red, and can be appropriately changed to yellow, blue, etc. according to the toning range of light emission of the entire light emitting device 1.

In the first embodiment, for example, a nitride aluminosilicate phosphor can be used as the red phosphor. More specifically, a phosphor having a peak wavelength of the fluorescence spectrum (second fluorescence peak wavelength) of 600 nm or more and 660 nm or less and a composition of (Sr, Ca) AlSiN ₃ : Eu ²⁺ (SCASN phosphor) Can be used. As in the case of the first phosphor 6a, an organic phosphor or the like can be used as the second phosphor 6b. However, an inorganic phosphor such as a SCASN phosphor is employed because of durability.

  The decreasing rate from the excitation efficiency A to the excitation efficiency B of the second phosphor 6b is preferably 20% or less, and may be 10% or less. Further, the excitation efficiency A and the excitation efficiency B of the second phosphor 6b may be approximately the same, and the reduction rate may be 0% or a value close to 0%. Furthermore, the excitation efficiency B may be higher than the excitation efficiency A of the second phosphor 6b, and the reduction rate may be a negative value such as −10%. If the reduction rate from the excitation efficiency A to the excitation efficiency B of the second phosphor 6b is designed to be smaller than the decrease rate from the excitation efficiency A to the excitation efficiency B of the first phosphor 6a, the output of the light emitting device 1 can be improved. It is possible to make the toning range of the incident light wider. In the SCASN phosphor used in the first embodiment, as shown in FIG. 3, the reduction rate from the excitation efficiency A to the excitation efficiency B is about −5%.

  FIG. 2 schematically shows the size of the second phosphor 6b. In actuality, a phosphor having an average particle size of 5 μm or more and 20 μm or less can be employed.

[Toning of emitted light from light emitting device]
Toning of the emitted light of the light emitting device 1 according to Embodiment 1 will be described with reference to FIG. In the first embodiment, the first light emitting element group 5a receives the supply of power from the external power source connected via the bonding wires, the wirings 12a and 12b, and the power supply terminals 10a and 10b. Emits light having a peak wavelength. Similarly, the second light emitting element group 5b has a second emission peak wavelength that is supplied with electric power from an external power source connected via bonding wires, wirings 12a and 12c, and power supply terminals 10a and 10c. Emits light.

  The first phosphor 6a is excited by the light emission of the first light emitting element 3a and the light emission of the second light emitting element 3b, and emits fluorescence having the first fluorescence peak. Similarly, the second phosphor 6b is excited by the light emission of the first light emitting element 3a and the light emission of the second light emitting element 3b, and emits fluorescence having the second fluorescence peak.

  Here, the decreasing rate from the excitation efficiency A to the excitation efficiency B of the first phosphor 6a is larger than the decreasing rate from the excitation efficiency A to the excitation efficiency B of the second phosphor 6b. That is, the first fluorescence excited by the light emission from the second light emitting element group 5b is compared with the mixed light of the fluorescence of the first phosphor 6a and the second phosphor 6b excited by the light emission from the first light emitting element group 5a. In the mixed light of the fluorescence of the body 6a and the second phosphor 6b, the fluorescent component of the first phosphor 6a is small. Thus, by adjusting the emission intensity ratio between the first light emitting element group 5a and the second light emitting element group 5b, the chromaticity of the mixed light of the fluorescence of the first phosphor 6a and the second phosphor 6b to be excited. Can be adjusted.

This will be described more specifically with reference to FIG. In FIG. 4, a point B is a chromaticity point of light emission from the first light emitting element 3a, a point G is a chromaticity point of fluorescence emission from the first phosphor 6a, and a point R is fluorescence from the second phosphor 6b. The chromaticity point of light emission is shown. A point P ₁ is a chromaticity point of the mixed light of the fluorescence of the first phosphor 6a and the second fluorescent material 6b by the excitation of the emission only from the first light emitting element 3a. Point P ₂ is the chromaticity point of the mixed light of the fluorescence of the first phosphor 6a and the second fluorescent material 6b by emitting only excitation from the second light emitting element 3b. Here, in Embodiment 1, since the 2nd light emission peak wavelength of the 2nd light emitting element 3b is an ultraviolet region, the chromaticity point is not displayed in FIG.

As described above, compared with the fluorescence mixed light of the first phosphor 6a and the second phosphor 6b excited by the light emission from the first light emitting element group 5a, the first light excited by the light emission from the second light emitting element group 5b. In the fluorescent mixed light of the first fluorescent body 6a and the second fluorescent body 6b, the fluorescent component of the first fluorescent body 6a is small. Thus, on the line GR, the point P ₁ is located at point G side, the point P ₂ is located to the point R side.

Higher emission intensity of the first light emitting element group 5a compared to the second light emitting element group 5b becomes strong, mixed light color point of the fluorescence of the first phosphor 6a and the second fluorescent material 6b is approaches the point P ₁ . Further, as the light emission intensity of the second light emitting element group 5b compared with the first group of light emitting elements 5a becomes strong, mixed light color point of the fluorescence of the first phosphor 6a and the second fluorescent material 6b is closer to the point P ₂ To go. In this way, by controlling the emission intensity of the first light emitting element group 5a and the second light emitting element group 5b and adjusting the ratio thereof, the color of the mixed light of the fluorescence of the first phosphor 6a and the second phosphor 6b The degree point can be adjusted on the line segment P ₁ P ₂ .

  If the chromaticity point of the mixed light of the fluorescence of the first phosphor 6a and the second phosphor 6b is a point P, the first light-emitting element group 5a and the second light-emitting element group 5b have the same emission intensity ratio and the first The stronger the emission intensity of the light emitting element group 5a, the closer the chromaticity point of the emitted light of the light emitting device 1 is to the point B side on the line segment BP. Further, as the light emission intensity of the first light emitting element group 5a is weaker, the chromaticity point of the emitted light of the light emitting device 1 is closer to the point P on the line segment BP. In this way, by adjusting the light emission intensity of the first light emitting element group 5a by making the light emission intensity ratio of the first light emitting element group 5a and the second light emitting element group 5b constant, the chromaticity point of the emitted light of the light emitting device 1 is achieved. Can be adjusted on the line segment BP.

Thus, the chromaticity point of the emitted light of the light emitting device 1 is adjusted to an arbitrary point in the triangle BP ₁ P ₂ by controlling the emission intensity of the first light emitting element group 5a and the second light emitting element group 5b, respectively. can do.

  In the first embodiment, white light toning can be performed as follows. For example, toning can be performed between the points H and L in FIG. In FIG. 4, the curve having the points H and L is a black body locus. Point H is a point on the high temperature side where the color temperature is about 6500K on the black body locus, and point L is a point on the low temperature side where the color temperature is about 2700K on the black body locus.

  In the first embodiment, the first light emitting element 3a is a blue LED having a first emission peak wavelength of about 450 nm (point B), and the second light emitting element 3b has a second emission peak wavelength of about 380 nm. It is an ultraviolet LED. The first phosphor 6a is a YAG-based phosphor that emits green light having a first fluorescence peak wavelength of about 550 nm (point G), and the second phosphor 6b has a second fluorescence peak wavelength of about 630 nm ( It is a SCASN phosphor that emits red light as point R).

  As shown in FIG. 3, the decrease rate from the excitation efficiency at the excitation wavelength of 450 nm to the excitation efficiency at the excitation wavelength of 380 nm was 80% or more, and the YAG phosphor was excited by light having a wavelength of 380 nm as compared with light having a wavelength of 450 nm. In the case, the emission intensity is much smaller. On the other hand, the SCASN phosphor exhibits an almost constant excitation efficiency from an excitation wavelength of 450 nm to an excitation wavelength of 380 nm, and the emission intensity changes substantially regardless of whether it is excited by light of a wavelength of 450 nm or light of a wavelength of 380 nm. Absent.

Therefore, the fluorescence mixed light of the YAG phosphor and the SCASN phosphor has an emission peak wavelength of 450.
The mixed light (point P ₂ ) excited only by ultraviolet light having an emission peak wavelength of 380 nm has less green light component than the mixed light (point P ₁ ) excited only by blue light of nm. Moreover, the chromaticity point of the fluorescent mixed light of the YAG phosphor and the SCASN phosphor can be adjusted on the line segment P ₁ P ₂ by adjusting the emission intensity ratio of the blue LED and the ultraviolet LED. .

  Here, when the chromaticity point of the fluorescent mixed light of the YAG phosphor and the SCASN phosphor is the point P, the emission intensity of the blue LED is adjusted while keeping the emission intensity ratio of the blue LED and the ultraviolet LED constant. By doing so, the chromaticity point of the emitted light of the light emitting device 1 can be adjusted on the line segment BP.

That is, the chromaticity point of the emitted light of the light emitting device 1 can be adjusted to an arbitrary point in the triangle BP ₁ P ₂ in the chromaticity coordinates by adjusting the emission intensity of the blue LED and the ultraviolet LED, respectively. it can.

Since the portion sandwiched between the point H and the point L of the black body locus exists in the triangle BP ₁ P ₂ , the chromaticity of the emitted light of the light emitting device 1 can be adjusted by adjusting the emission intensity of the blue LED and the ultraviolet LED. The point can be adjusted to an arbitrary point between points H and L on the black body locus.

  Here, the reason why 450 nm is adopted as the first emission peak wavelength and 380 nm is adopted as the second emission peak wavelength will be described. The SCASN phosphor exhibits substantially constant excitation efficiency at wavelengths of 450 nm and 380 nm. On the other hand, since the YAG phosphor has a minimum excitation efficiency at a wavelength of about 380 nm, the excitation efficiency at a wavelength of 380 nm is greatly reduced compared to the excitation efficiency at a wavelength of 450 nm.

  Therefore, if excitation is performed at two wavelengths of 450 nm and 380 nm, the chromaticity of the fluorescent mixed light of the YAG phosphor and the SCASN phosphor can be greatly adjusted. As a result, the toned range of the emitted light of the light emitting device 1 can be increased, so that 450 nm is adopted as the first emission peak wavelength and 380 nm is adopted as the second emission peak wavelength.

  Here, the first emission peak wavelength and the second emission peak wavelength are not limited to the wavelength 450 nm and the wavelength 380 nm, and can be appropriately set according to the toning range of the emitted light of the light emitting device 1. Further, the first fluorescence peak wavelength and the second fluorescence peak wavelength are not limited to the wavelength 550 nm and the wavelength 630 nm, and can be appropriately set according to the toning range of the emitted light of the light emitting device 1.

Incidentally, as the second light emitting element 3b, when using a light-emitting element exhibiting emission in the visible light region, rectangles were added chromaticity point of the second emission peak wavelength of the second light emitting element 3b (the point Z) BP ₁ The chromaticity point of the emitted light of the light emitting device 1 can be adjusted to an arbitrary point in P ₂ Z. The reason will be described below.

By adjusting the light emission intensity ratio between the first light emitting element group 5a and the second light emitting element group 5b, the chromaticity point of the mixed light of the first light emitting element group 5a and the second light emitting element group 5b (referred to as point W). ) Can be adjusted on the line segment BZ. Further, by adjusting the emission intensity of the mixed light of the first light emitting element group 5a and the second light emitting element group 5b, the chromaticity point of the emitted light of the light emitting device 1 can be adjusted on the line segment PW. Therefore, the chromaticity point of the emitted light of the light emitting device 1 can be adjusted to an arbitrary point in the quadrangle BP ₁ P ₂ Z.

[Arrangement of first light emitting element and second light emitting element]
A manner of arrangement of the first light emitting element 3a and the second light emitting element 3b on the substrate and a modification thereof will be described with reference to FIGS. FIG. 5 is a schematic diagram of a modification of the light emitting device according to Embodiment 1.

  In Embodiment 1, it is preferable that the 1st light emitting element 3a and the 2nd light emitting element 3b are arrange | positioned so that it may become alternate. For example, in the light emitting device 1 schematically shown in FIG. 1, the first light emitting elements 3a and the second light emitting elements 3b are alternately arranged in the vertical direction in FIG. In this way, the first light emitting element 3a and the second light emitting element 3b are alternately arranged, so that there is no bias in the arrangement of the first light emitting element 3a and the second light emitting element 3b, and the emission light of the light emitting device 1 is transmitted. A decrease in color mixing can be prevented.

The decrease in the color mixing property of the emitted light from the light emitting device 1 occurs for the following reason. For example, it is assumed that there is a portion A in which a relatively large amount of the first light emitting elements 3a is present and a portion B in which a relatively large amount of the second light emitting elements 3b are present. Since there are more first light emitting elements 3a than the second light emitting elements 3b, the chromaticity point of the emitted light in the portion A is point B on the chromaticity coordinates with respect to the chromaticity point of the average emitted light of the entire light emitting device 1. Located on the side. Since there are more second light emitting elements 3b than the first light emitting elements 3a, the chromaticity point of the emitted light in the portion B is a line segment on the chromaticity coordinate rather than the average chromaticity point of the emitted light of the entire light emitting device 1. Located on the P ₁ P ₂ side. In other words, the chromaticity of the emitted light is different between the portion A and the portion B, thereby reducing the color mixing property.

  As described above, the color mixing property can be prevented from being lowered by suppressing the deviation in the arrangement distribution of the first light emitting elements 3a and the second light emitting elements 3b. Therefore, in addition to the staggered case as shown in FIG. 1, an arrangement method that suppresses a deviation in the arrangement distribution of the first light emitting elements 3a and the second light emitting elements 3b may be employed. For example, even when the first light emitting element 3a and the second light emitting element 3b are arranged at random, the effect of preventing color mixing from being lowered can be obtained. Further, even when a concentric arrangement as in the modification of the light emitting device 1 shown in FIG.

  Further, the distribution of the first phosphor 6a and the second phosphor 6b in the sealing material 4 is preferably less biased. This is because the lower the distribution bias between the first phosphor 6a and the second phosphor 6b in the sealing material 4, the more the color mixing property can be prevented from decreasing.

[Lighting device]
An illumination device 7 using the light-emitting device 1 according to Embodiment 1 will be described with reference to FIG. FIG. 6 is a schematic cross-sectional view of a lighting device including the light-emitting device according to Embodiment 1. In Embodiment 1, the case where the light-emitting device 1 is used for a downlight as shown in FIG. 6 will be described. A downlight type illumination device 7 as shown in FIG. 6 is installed in a ceiling in a house or the like so as to irradiate light downward. Note that the light-emitting device 1 according to Embodiment 1 can be used in other illumination devices such as a spotlight, for example, other than the downlight.

  The illumination device 7 includes the light emitting device 1 and a control unit (not shown). The control unit separately controls the light emission intensity of the first light emitting element group 5a and the light emission intensity of the second light emitting element group 5b. The lighting device 7 further includes a base 70, a frame body 72, a reflection plate 73, and a translucent panel 74. The base 70 and the frame body 72 are combined to form a substantially cylindrical instrument body having a bottom. A reflection plate 73 and a translucent panel 74 are provided in the instrument body.

  The light emitting device 1 is attached to the base 70. The base 70 is formed in a substantially cylindrical shape and is made of a metal material such as aluminum. Further, a heat radiating fin 71 is provided on the side of the base 70 where the light emitting device 1 is not attached. The heat dissipating fins 71 are provided at regular intervals along one direction. The heat generated by the light emitting device 1 can be efficiently radiated by the heat radiating fins 71.

  The frame body 72 includes a substantially cylindrical cone portion 72a having a reflection surface on the inner surface, and a frame body main body 72b to which the cone portion 72a is attached. The cone part 72a can be formed using, for example, a metal material such as aluminum. Specifically, it can be produced by subjecting an aluminum alloy or the like to drawing or press forming. The frame body 72b can be formed using, for example, a hard resin material or a metal material. The frame body 72 is fixed by attaching the frame body main body 72 b to the base portion 70.

  The reflecting plate 73 is an annular frame-shaped reflecting member whose inner surface has a reflecting function. When the light emitted from the light emitting device 1 reaches the reflection plate 73, it is reflected by the inner surface of the reflection plate 73 in the emission direction of the illumination device 7 (downward in the downlight). Thus, the light extraction efficiency of the illumination device 7 can be increased by reflecting the light of the emitted light in the emission direction of the illumination device 7. The reflector 73 is made of a metal material such as aluminum, for example. Moreover, you may be comprised with the hard white resin material etc. instead of a metal material.

  The translucent panel 74 is a member having light diffusibility and translucency. The translucent panel 74 is a flat plate disposed between the reflection plate 73 and the frame body 72. The translucent panel 74 can be formed of a transparent resin material such as acrylic or polycarbonate, for example. Moreover, a disk shape can be adopted as the shape. In addition, the illuminating device 7 does not need to include the translucent panel 74. In that case, the luminous flux of the emitted light from the illumination device 7 can be improved.

  As described above, the illuminating device 7 according to Embodiment 1 has the control unit that individually controls the light emission intensity of the light emitting device 1 and the first light emitting element group 5a and the second light emitting element group 5b. According to the illuminating device 7 according to Embodiment 1, the emitted light of the illuminating device 7 is adjusted within a certain region of chromaticity coordinates by adjusting the emission intensity of the first light emitting element group 5a and the second light emitting element group 5b. The chromaticity point can be arbitrarily set.

(Embodiment 2)
Below, Embodiment 2 which concerns on this invention is demonstrated using FIG.7 and FIG.8. FIG. 7 is a schematic diagram of the light emitting device according to the second embodiment. FIG. 8 is a schematic cross-sectional view of the light emitting device according to the second embodiment. In the second embodiment, since the configuration of the light emitting device 1 is different from that of the first embodiment, the configuration of the light emitting device 1 will be mainly described, and the description of the same parts as those of the first embodiment will be simplified or omitted. To do. The same components as those in the first embodiment will be described with the same reference numerals. The light emitting device 1 according to Embodiment 2 can be used mainly for a straight tube type lighting device or the like.

[Light emitting device]
The light emitting device 1 according to Embodiment 2 includes a substrate 2, a first light emitting element 3 a, a second light emitting element 3 b, and a sealing material 4. The substrate 2 has an elongated, substantially rectangular shape. As a material constituting the substrate 2, a ceramic substrate such as alumina can be used.

  As for the first light emitting element 3a and the second light emitting element 3b, LED chips can be used as in the first embodiment. Similarly to the first embodiment, the first light emitting element 3a can be one that emits blue light, and the second light emitting element 3b can be one that emits ultraviolet light.

The plurality of first light emitting elements 3 a and the plurality of second light emitting elements 3 b are arranged on a straight line along the longitudinal direction on the substrate 2. In FIG. 7, there is one straight line composed of the first light emitting element 3 a and the second light emitting element 3 b, but the straight line composed of the first light emitting element 3 a and the second light emitting element 3 b is 1.
It is not limited to a book, Two, three, or more may be sufficient.

  The first light emitting element 3a and the second light emitting element 3b are connected to a power supply terminal (not shown) by a bonding wire, and power is supplied to the first light emitting element 3a and the second light emitting element 3b through the power supply terminal. Is done.

  The first light emitting element group 5a includes a plurality of first light emitting elements 3a arranged on one substrate 2. Similarly, the second light emitting element group 5b includes a plurality of first light emitting elements 5a arranged on one substrate 2. It consists of two light emitting elements 3b. Further, the light emission intensity of the first light emitting element group 5a and the second light emitting element group 5b is controlled separately.

  The sealing material 4 is a material that seals the first light emitting element 3a, the second light emitting element 3b, and the bonding wire that connects them. Further, the first phosphor 6 a and the second phosphor 6 b are sealed in a state of being dispersed inside the sealing material 4. As a material constituting the sealing material 4, a light transmissive resin such as a silicone resin can be used.

  As in the first embodiment, the first phosphor 6a can employ a YAG phosphor, and the second phosphor 6b can employ a SCASN phosphor. Also in the second embodiment, as in the first embodiment, the decreasing rate from the excitation efficiency A to the excitation efficiency B of the first phosphor 6a is changed from the excitation efficiency A to the excitation efficiency B of the second phosphor 6b. Therefore, the same color matching as in the first embodiment is possible.

[Arrangement of first light emitting element and second light emitting element]
When the first light emitting element 3a and the second light emitting element 3b are installed on the substrate 2 in a straight line, the first light emitting element 3a and the second light emitting element 3b are preferably arranged alternately. It is because it can prevent that the color mixing property of the emitted light of the light-emitting device 1 falls.

  For example, when the first light emitting element 3a and the second light emitting element 3b are arranged so as to form one straight line, the first light emitting element 3a and the second light emitting element 3b are alternately arranged to make a stagger. Can be achieved.

  Also, when there are a plurality of straight lines composed of the first light emitting element 3a and the second light emitting element 3b, the first light emitting element 3a and the second light emitting element 3b are not adjacent to each other, that is, are alternately arranged. Is preferred. It is because it can prevent that the color mixing property of the emitted light of the light-emitting device 1 falls.

(Effects of light-emitting device and lighting device according to the present invention)
Here, the present invention will be described again.

  The light emitting device 1 according to the present invention includes a first light emitting element group 5a having a plurality of first light emitting elements 3a, a second light emitting element group 5b having a plurality of second light emitting elements 3b, And a sealing material 4 for sealing the light emitting element group 5a and the second light emitting element group 5b. The first light emitting element 3a emits light at the first emission peak wavelength, and the second light emitting element 3b emits light at the second emission peak wavelength. A first phosphor 6a and a second phosphor 6b are enclosed in a dispersed state in the sealing material 4 having translucency. The first phosphor 6a emits fluorescence at the first fluorescence peak wavelength, and the second phosphor emits fluorescence at the second fluorescence peak wavelength. The first phosphor 6a has higher excitation efficiency at the first emission peak wavelength than excitation efficiency at the second emission peak wavelength. In addition, the rate of decrease from the excitation efficiency at the first emission peak wavelength to the excitation efficiency at the second emission peak wavelength is smaller in the second phosphor 6b than in the first phosphor 6a.

According to the light emitting device 1 having the above-described configuration, the chromaticity point of the emitted light can be adjusted within a certain region of the chromaticity coordinates by separately adjusting the light emission intensity of the first light emitting element group 5a and the second light emitting element group 5b. Can be set arbitrarily. Here, the chromaticity point of the first emission peak wavelength is point B, and the chromaticity point of the second emission peak wavelength is point Z. Further, the chromaticity point of the mixed light of the fluorescence of the first phosphor 6a and the second phosphor 6b by the light emission of the first light emitting element 3a and a point P _1, a first phosphor 6a of light emitted of the second light emitting element 3b the chromaticity point of the mixed light of the fluorescence of the second phosphor 6b and point P _2. The above-mentioned constant region of chromaticity coordinates is inside the quadrangle BP ₁ P ₂ Z.

  In the light emitting device 1 according to the present invention, the rate of decrease from the excitation efficiency at the first emission peak wavelength to the excitation efficiency at the second emission peak wavelength is 50% or more in the first phosphor 6a, and in the second phosphor 6b. It is preferable that it is 20% or less.

  The difference between the first phosphor 6a and the second phosphor 6b in the decrease rate from the excitation efficiency at the first emission peak wavelength to the excitation efficiency at the second emission peak wavelength is increased, and the toning of the emitted light of the light emitting device 1 is performed. This is because the possible range can be increased.

  The first emission peak wavelength is 430 nm or more and preferably 480 nm or less. The second emission peak wavelength is 350 nm or more and preferably 400 nm or less. Further, the first fluorescence peak wavelength is 530 nm or more and preferably 560 nm or less. The first phosphor 6a is preferably an yttrium / aluminum / garnet phosphor. Further, the second fluorescence peak wavelength is 600 nm or more and preferably 660 nm or less. The second phosphor 6b is preferably a nitride aluminosilicate phosphor.

  This is because the chromaticity point of the emitted light from the light emitting device 1 can be adjusted on the black body locus and the color temperature of the white light emitted from the light emitting device 1 can be adjusted by adopting the above configuration.

  Moreover, it is preferable that the 1st light emitting element 3a and the 2nd light emitting element 3b are arrange | positioned so that it may become alternate.

  With the arrangement as described above, it is possible to prevent the color mixing property of the emitted light of the light emitting device 1 from being lowered by reducing the deviation of the arrangement distribution of the first light emitting element 3a and the second light emitting element 3b.

  The illumination device 7 according to the present invention includes a control unit that controls the light emission intensity of each of the light-emitting device 1 and the first light-emitting element group 5a and the second light-emitting element group 5b.

According to the illuminating device 7 having the above-described configuration, the chromaticity point of the emitted light can be adjusted within a certain region of chromaticity coordinates by separately adjusting the emission intensity of the first light emitting element group 5a and the second light emitting element group 5b. Can be set arbitrarily. Here, the chromaticity point of the first emission peak wavelength is point B, and the chromaticity point of the second emission peak wavelength is point Z. Further, the chromaticity point of the mixed light of the fluorescence of the first phosphor 6a and the second phosphor 6b by the light emission of the first light emitting element 3a and a point P _1, a first phosphor 6a of light emitted of the second light emitting element 3b the chromaticity point of the mixed light of the fluorescence of the second phosphor 6b and point P _2. The above-mentioned constant region of chromaticity coordinates is inside the quadrangle BP ₁ P ₂ Z.

(Other embodiments)
As described above, the light-emitting device and the lighting device according to the present invention have been described using Embodiments 1 and 2, but the present invention is not limited to these embodiments.

For example, the light emitting device 1 may be configured by adding one or more light emitting elements to the first light emitting element 3a and the second light emitting element 3b so that the toned area can be designed more flexibly. It is also possible to improve the color rendering properties of the light emitting device 1 by adding one or more phosphors to the first phosphor 6a and the second phosphor 6b.

  In the first and second embodiments, the light emission intensity is controlled as the entire first light emitting element group 5a, and the light emission intensity is controlled as the entire second light emitting element group 5b. The emission intensity may be controlled for each, and the emission intensity may be controlled for each second light emitting element 3b. By controlling the light emission intensity for each light emitting element, it is possible to control the color mixing property and chromaticity of the light emitted from the light emitting device 1 with a small portion. Further, the emission intensity may be adjusted for each first light emitting element array and each second light emitting element array. In order to achieve these configurations, it is necessary to increase the number of power supply terminals.

  In addition, about Embodiment 1 and 2 mentioned above, it is only an illustration of the embodiment of this invention, and it is only an illustration of what is preferable also about material, a numerical value, a shape, etc., This invention is limited only to these embodiment. Is not to be done. The configuration can be appropriately changed without departing from the scope of the technical idea of the present invention.

DESCRIPTION OF SYMBOLS 1 Light-emitting device 2 Board | substrate 3a 1st light emitting element 3b 2nd light emitting element 4 Sealing material 5a 1st light emitting element group 5b 2nd light emitting element group 6a 1st fluorescent substance 6b 2nd fluorescent substance 7 Illuminating device

Claims (10)

A substrate,
A first light-emitting element group having a plurality of first light-emitting elements disposed on the substrate and emitting light at a first emission peak wavelength;
A second light emitting element group having a plurality of second light emitting elements disposed on the substrate and emitting light at a second emission peak wavelength;
A sealing material having translucency and sealing the first light emitting element group and the second light emitting element group;
A first phosphor encapsulated in the encapsulant and emitting fluorescence at a first fluorescence peak wavelength;
A second phosphor encapsulated in the encapsulant and emitting fluorescence at a second fluorescence peak wavelength,
The first phosphor has higher excitation efficiency at the first emission peak wavelength than excitation efficiency at the second emission peak wavelength,
The light emitting device having a decrease rate from the excitation efficiency at the first emission peak wavelength to the excitation efficiency at the second emission peak wavelength is smaller in the second phosphor than in the first phosphor. The reduction rate of the first phosphor is 50% or more,
The light emitting device according to claim 1, wherein the reduction rate of the second phosphor is 20% or less.   The light emitting device according to claim 1 or 2, wherein the first emission peak wavelength is not less than 430 nm and not more than 480 nm.   The light emitting device according to claim 1, wherein the second emission peak wavelength is 350 nm or more and 400 nm or less.   The light emitting device according to claim 1, wherein the first fluorescence peak wavelength is 530 nm or more and 560 nm or less.   The light emitting device according to claim 5, wherein the first phosphor is an yttrium aluminum garnet phosphor.   The light emitting device according to claim 1, wherein the second fluorescence peak wavelength is 600 nm or more and 660 nm or less.   The lighting device according to claim 7, wherein the second phosphor is a nitride aluminosilicate phosphor.   The light-emitting device according to claim 1, wherein the first light-emitting element and the second light-emitting element are arranged so as to alternate with each other. A light emitting device according to any one of claims 1 to 9,
An illumination device having a control unit that controls the emission intensity of each of the first light emitting element group and the second light emitting element group.

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