JP2015211150A - Wavelength conversion member and illumination device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wavelength conversion member with a high color rendering property capable of obtaining a high efficient LED illumination light source, and an illumination device using the same.SOLUTION: A wavelength conversion member (10) has wavelength conversion particles (1) each of which includes: a first fluorescent particle (2) which has a luminescence peak in wavelength range of 595-800 nm; and a coating (3) which covers the surface of the first fluorescent particles and absorbs light of a specific wavelength in the light emitted from the first fluorescent particle. The wavelength conversion member further includes second fluorescent particles (6) whose luminescence peak resides at the shorter wavelength side than the first fluorescent particles. An illumination device (100) includes the wavelength conversion member.

Description

  The present invention relates to a wavelength conversion member and an illumination device using the same. Specifically, the present invention relates to a wavelength conversion member that realizes an LED illumination light source that has high color rendering properties and high efficiency, and an illumination device that uses the wavelength conversion member.

  2. Description of the Related Art Conventionally, a light emitting diode lamp (LED lamp) including a light emitting diode chip (LED chip) is used in many fields such as a signal lamp, a mobile phone, various electric decorations, an in-vehicle display, and various display devices. In addition, the LED chip is combined with a phosphor that emits long-wavelength light when excited by the light emitted from the LED chip, and the emission spectrum is controlled to achieve light emission with a color different from the LED chip emission color. Research and development of lighting equipment is underway.

And until now, the following methods have been proposed for spectrum control of LED illumination.
(1) A method of obtaining a pseudo white light by combining a blue LED chip and a yellow phosphor (2) A method of enhancing the color rendering by combining a blue LED chip with an orange phosphor or a red phosphor in addition to a yellow phosphor

  Further, in order to further improve the color rendering properties of LED lighting, finer spectrum control is required. As a method for finely controlling the emission spectrum, for example, a method for controlling the emission spectrum by covering the LED chip with a filter that absorbs light of a specific wavelength has been proposed (see, for example, Patent Documents 1 to 3). That is, in the devices of Patent Documents 1 to 3, the filter material is dispersed in a sealing resin or a cover, and a part of light emitted from the phosphor is absorbed by the filter material, thereby controlling the spectral shape of the LED illumination and performing color rendering. Increases sex.

  Furthermore, an illumination device has been proposed in which the LED element is covered with a filter having an absorption characteristic at 570 to 580 nm, thereby rendering the color of meat vividly and further suppressing giving an unnatural impression to humans. (For example, see Patent Document 4).

JP 2004-119984 A JP 2004-193581 A JP 2011-199054 A JP2013-127855A

  However, when the filter material is dispersed in the sealing resin or the cover, if the filter material is not sufficiently dispersed, scattering due to aggregation of the filter material occurs, which may reduce the efficiency of LED illumination. In addition, when the particle size of the filter material is from submicron size to micron size, the efficiency of LED illumination may be reduced due to scattering of the filter material itself.

  The present invention has been made in view of such problems of the prior art. And the objective of this invention is providing the wavelength conversion member which can obtain a highly efficient LED illumination light source with high color rendering properties, and an illuminating device using the same.

  The wavelength conversion member according to an aspect of the present invention includes a first phosphor particle having an emission peak in a wavelength region of 595 nm or more and 800 nm or less, and light emitted from the first phosphor particle that covers the surface of the first phosphor particle. Wavelength conversion particle | grains provided with the film which absorbs the light of a specific wavelength among these. The wavelength conversion member further includes second phosphor particles having a light emission peak on the short wavelength side of the first phosphor particles.

  The wavelength conversion member of the present invention uses wavelength conversion particles in which the first phosphor particles are covered with a film that absorbs light of a specific wavelength, and the emission peak is present on the shorter wavelength side than the first phosphor particles. Two phosphor particles are combined with wavelength conversion particles. For this reason, since it is possible to efficiently reduce the light that lowers the color rendering properties, it is possible to obtain a lighting device that has high color rendering properties and high efficiency.

It is the schematic which shows the wavelength conversion member which concerns on embodiment of this invention. It is a scanning microscope picture which shows an example of a wavelength conversion particle. (A) shows the phosphor particles before forming the coating, (b) shows the phosphor particles after forming the coating, and (c) is an enlarged photograph of the phosphor particles shown in (b). It is a figure which shows the emission spectrum of fluorescent substance particle | grains and wavelength conversion particle | grains. It is the schematic for demonstrating the illuminating device which concerns on embodiment of this invention. It is a perspective view showing typically an example of a semiconductor lighting device concerning an embodiment of the present invention. (A) is the sectional view on the AA line in FIG. 5, (b) is the sectional view on the BB line in FIG. It is a figure for demonstrating the formation method of the sealing member in a semiconductor illuminating device.

  Hereinafter, the wavelength conversion member which concerns on embodiment of this invention, and the illuminating device using the said wavelength conversion member are demonstrated in detail. In addition, the dimension ratio of drawing is exaggerated on account of description, and may differ from an actual ratio.

[Wavelength conversion member]
The wavelength conversion member according to the present embodiment includes a first phosphor particle having an emission peak in a wavelength region of 595 nm to 800 nm, a surface of the first phosphor particle, and light emitted from the first phosphor particle. Among these, wavelength conversion particles provided with a film that absorbs light of a specific wavelength are provided. Further, the wavelength conversion member includes second phosphor particles having a light emission peak on the shorter wavelength side than the first phosphor particles.

<Wavelength conversion particles>
The wavelength conversion particle according to the present embodiment has a function of absorbing incident excitation light and emitting light having a longer wavelength than the excitation light. As shown in FIG. 1, the wavelength conversion particle 1 covers the surface of the first phosphor particle 2 and the first phosphor particle 2, and emits light having a specific wavelength among the light emitted by the first phosphor particle 2. And a film 3 to be absorbed.

  When the wavelength conversion particle 1 is provided with such a coating 3, it becomes possible to efficiently absorb light having a specific wavelength among the light emitted from the first phosphor particles 2. That is, as in the devices of Patent Documents 1 to 4, when a filter in which a filter material is dispersed in a sealing resin or a cover is provided on the surface of the phosphor, the light emitted from the first phosphor particles is scattered, There was a possibility that the luminous efficiency would decrease. However, in the present embodiment, the coating 3 is formed so as to be in direct contact with the surface of the first phosphor particles 2, and the coating 3 absorbs light of a specific wavelength. For this reason, it is possible to suppress a decrease in light emission efficiency due to scattering of the filter material itself as in the prior art.

  Moreover, when a filter is used like the apparatus of patent documents 1 thru | or 4, a space | interval arises between a fluorescent substance particle and a filter. And since reflection and scattering of light occur on the filter surface, it is necessary to use a large amount of filter material in order to sufficiently absorb light of a specific wavelength by the filter material. However, in the wavelength conversion particle 1 according to the present embodiment, the coating 3 is in direct contact with the surface of the first phosphor particle 2. Therefore, absorption loss of light emitted from the first phosphor particles 2 is suppressed without using a large amount of filter material, and the coating 3 can efficiently absorb light of a specific wavelength.

  When a filter is used, light is reflected and scattered on the filter surface, and the incident efficiency of excitation light to the first phosphor particles 2 and the extraction efficiency of light emitted from the first phosphor particles 2 are increased. There was a risk of decline. However, in the wavelength conversion particle 1 according to the present embodiment, the coating 3 is in direct contact with the surface of the first phosphor particle 2. Therefore, reflection and scattering of light can be suppressed, and the incident efficiency of excitation light to the first phosphor particles 2 and the extraction efficiency of light emitted from the first phosphor particles 2 can be improved.

In the present embodiment, it is preferable to use a phosphor having an emission peak in the wavelength region of 595 nm or more and 800 nm or less as the material of the first phosphor particle 2. As such a phosphor, at least one of an orange phosphor and a red phosphor can be used. No particular limitation is imposed on the orange phosphor, for ^{_{example, Sr 3 SiO 5: Eu 2+}} , α-Ca-SiAlON: Eu 2+ and the like. The red phosphor is not particularly limited, and examples thereof include CaAlSiN ₃ : Eu ²⁺ (CASN), (Ca, Sr) AlSi ₄ N ₇ : Eu ²⁺ (SCASN), Sr ₂ Si ₅ N ₈ : Eu ^{3+, and the} like. Can do. In addition, these fluorescent substance may be used individually by 1 type, and may be used in combination of 2 or more type.

  The average particle diameter (median diameter, d50) of the first phosphor particles 2 is not particularly limited. However, the larger the average particle diameter of the first phosphor particles 2, the smaller the surface defect density in the phosphor particles and the less energy loss at the time of light emission, resulting in higher luminous efficiency. For this reason, from the viewpoint of improving luminous efficiency, the average particle size of the first phosphor particles 2 is preferably 1 μm or more, and more preferably 5 μm or more. In particular, the average particle diameter of the first phosphor particles 2 is preferably in the range of 8 μm to 50 μm. The average particle diameter of the first phosphor particles 2 can be determined by a laser diffraction / scattering method using a laser diffraction particle size distribution measuring device.

  As described above, the coating 3 has a function of absorbing light having a specific wavelength among the light emitted from the first phosphor particles 2, and further contains an element or a compound that exhibits such specific light absorption ability. It is preferable. Although the said element and compound contained in the film 3 are not specifically limited, It is preferable that the film 3 contains the neodymium compound 4 which absorbs the light of a specific wavelength. Neodymium compounds have absorption in the 530 nm and 580 nm regions. Therefore, by including the neodymium compound 4 in the coating 3, it becomes possible to cut a spectral component near 580 nm in the light emitted from the first phosphor particles 2.

As such a neodymium compound 4, it is preferable to use a trivalent neodymium compound. Specifically, examples of the neodymium compound 4 include neodymium hydroxide (Nd (OH) ₃ ), neodymium oxide (Nd ₂ O ₃ ), neodymium aluminate (NdAlO ₃ ), and neodymium-doped glass. A neodymium compound may be used individually by 1 type, and may be used in combination of 2 or more type.

  Moreover, it is also preferable that the film 3 contains an organic dye having absorption in the vicinity of 570 nm to 590 nm. By containing the organic dye, it is possible to absorb and cut a spectral component in the vicinity of 570 nm to 590 nm in the light emitted from the first phosphor particles 2, similarly to the neodymium compound. Further, as will be described later, it is preferable to disperse the wavelength conversion particles 1 inside the translucent medium 7. In this case, since the periphery of the organic dye contained in the coating 3 is covered with the translucent medium 7, the oxidation by oxygen in the air is suppressed, and the stability of the organic dye can be improved. Examples of such organic dyes include at least one selected from the group consisting of phthalocyanine compounds, naphthalocyanine compounds, cyanine compounds, fluoran compounds, tetraazaporphyrin compounds, anthraquinone compounds, azo compounds, and porphyrin compounds. Can be used. A fluorescent dye or the like may be used as the organic dye.

  The coating 3 may contain any one of the neodymium compound and the organic dye, or may contain both of them. In addition to the neodymium compound and the organic dye, the coating 3 may contain a binder 5 that bonds these particles to increase the stability of the coating 3. Although it does not specifically limit as the binder 5, For example, the silicon compound which has a siloxane bond like the hydrolysis-condensation product of an alkoxysilane can be used.

  In addition, when the film 3 contains a neodymium compound, it is preferable that content of the neodymium compound in the film 3 is 30 vol% or more from a viewpoint of efficiently absorbing the spectral component around 580 nm. Further, the content of the neodymium compound in the coating 3 is more preferably 40 vol% or more, and particularly preferably 50 vol% or more.

  The thickness of the coating 3 is preferably 10 nm or more and 1 μm or less. When the film thickness is 10 nm or more, it is possible to secure a thickness for sufficiently absorbing a spectral component near 580 nm and improve the absorption efficiency. Moreover, even if there are irregularities on the surface of the first phosphor particles 2, it is possible to cover the first phosphor particles 2 substantially uniformly. When the film thickness is 1 μm or less, the coating 3 is hardly cracked, and peeling is suppressed. Moreover, since the scattering of the excitation light and the radiated light by the coating film is reduced, it is possible to suppress a decrease in light incident efficiency and extraction efficiency.

  The thickness of the coating 3 is more preferably 20 nm or more and 500 nm or less, and particularly preferably 50 nm or more and 250 nm or less. By setting it within this range, a substantially uniform film can be obtained, so that the absorption efficiency of the spectral component can be further improved. In addition, the thickness of the film 3 can be measured using, for example, a scanning electron microscope (SEM) or a transmission electron microscope (TEM).

  Most preferably, the coating 3 covers the entire surface of the first phosphor particle 2. However, from the viewpoint of improving the absorption efficiency of light of a specific wavelength, the coating 3 preferably covers at least 60% or more of the surface of the first phosphor particle 2. The coating 3 preferably covers 80% or more of the surface of the first phosphor particle 2, and more preferably covers 90% or more. When the coverage of the coating 3 is 90% or more, it is possible to further improve the absorption efficiency for light of a specific wavelength.

  Next, the manufacturing method of the wavelength conversion particle | grains 1 of this embodiment is demonstrated. In producing the wavelength conversion particle 1, there is no particular limitation on the method for forming the coating 3 by attaching at least one of a neodymium compound and an organic dye on the first phosphor particle 2. However, the film 3 can be efficiently formed by a general wet coating method (sol-gel method), a spray coating method (spray dry method), or the like.

  And when forming the film 3 by a wet coating method or a spray coating method, when the average particle diameter of the neodymium compound to be used is 10 nm or less, use the nanoparticle dispersion which disperse | distributed the neodymium compound in the solvent. Can do. In addition to the nanoparticle dispersion, a so-called sol-gel material such as an alkoxide hydrolysis condensate (microscopically an aggregate of nanoparticles of several to 10 nm) may be used. The use of nanoparticles or sol-gel materials having an average particle diameter of 10 nm or less as described above is more preferable because film scattering is further suppressed.

  The wavelength conversion particles can also be produced by the following method. First, phosphor particles and neodymium compounds and / or organic dyes are prepared, and these are added to a dispersion medium such as water or alcohol to prepare a mixed solution. At this time, if necessary, a binder such as a hydrolysis-condensation product of alkoxysilane may be added. Next, after this liquid mixture is stirred, the wavelength conversion particles can be obtained by isolation and drying. The wavelength conversion particles can also be obtained by spray drying the mixed solution using a spray dryer or the like.

FIG. 2 shows an example of the wavelength conversion particles obtained as described above. The wavelength conversion particles shown in FIG. 2 have a coating 3 formed on the surface of an yttrium / aluminum / garnet phosphor (YAG phosphor). Then, the film 3 is a neodymium oxide (Nd 2 _{O 3),} contains the hydrolyzed condensate of alkoxysilane as a binder. Specifically, it is obtained by mixing a YAG phosphor, tetraethoxysilane, neodymium chloride (NdCl ₃ ), and water, adding ammonia, and drying the solid content.

  As shown in FIG. 2A, the surface of the YAG phosphor is relatively smooth before the coating 3 is formed. However, as shown in FIGS. 2B and 2C, it can be confirmed that the particle diameter is increased after the coating 3 is formed, and the irregularities on the surface of the particles are increased. The YAG phosphor is not a phosphor having an emission peak at 595 nm or more and 800 nm or less. However, the YAG phosphor also has the same particle shape as the phosphor having an emission peak at 595 nm to 800 nm. Therefore, even when the first phosphor particles having an emission peak at 595 nm or more and 800 nm or less are used, it is considered that the particle shape is similar to that in FIG.

Further, FIG. 3 shows an emission spectrum of wavelength-converted particles in which a film composed of a neodymium oxide (Nd ₂ O ₃ ) and a hydrolysis condensate of alkoxysilane is formed on the surface of the YAG phosphor. FIG. 3 also shows an emission spectrum in which the weight ratio between the YAG phosphor and the neodymium atom is changed. As shown in FIG. 3, it can be seen that the emission intensity in the vicinity of 530 nm and 580 nm decreases as the weight ratio of neodymium (Nd ³⁺ ) in the coating increases. That is, it can be seen that Nd ³⁺ partially absorbs the fluorescent component emitted by Ce ³⁺ which is the emission center of the YAG phosphor, and induces a narrowing of the fluorescence spectrum. Since Nd ³⁺ has a strong absorption characteristic in the yellow wavelength region of 570 nm to 590 nm, the intensity of the yellow light component can be effectively reduced.

  Thus, by providing the coating 3 that absorbs light of a specific wavelength on the surface of the first phosphor particle 2, the emission spectrum of the wavelength conversion particle 1 has a shape different from the emission spectrum of the first phosphor particle 2. Become.

<Second phosphor particles>
The wavelength conversion member 10 of the present embodiment includes second phosphor particles 6 having a light emission peak on the shorter wavelength side than the first phosphor particles 2 in addition to the wavelength conversion particles 1 described above. As described above, the first phosphor particle 2 in the wavelength conversion particle 1 has an emission peak in the orange to red wavelength region of 595 nm to 800 nm. Therefore, by combining the wavelength conversion particle 1 that emits orange to red light and the second phosphor particle 6 that emits short wavelength light, light emission having a color different from the emission color of the LED chip, for example, white light is realized. Is possible. Further, as described above, since the wavelength conversion particle 1 includes the coating 3 that absorbs light of a specific wavelength, it is possible to perform finer spectrum control and enhance color rendering.

  As the second phosphor particles, any phosphor can be used as long as the phosphor has an emission peak on the short wavelength side as compared with the first phosphor particles 2. As such a phosphor, for example, at least one selected from the group consisting of a blue phosphor, a green-blue phosphor, a blue-green phosphor, a green phosphor, a yellow phosphor, an orange phosphor and a red phosphor is used. Is preferred.

Examples of the blue phosphor include BaMgAl ₁₀ O ₁₇ : Eu ²⁺ , CaMgSi ₂ O ₆ : Eu ²⁺ , Ba ₃ MgSi ₂ O ₈ : Eu ²⁺ , and Sr ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu ²⁺ . Examples of the green-blue or blue-green phosphor include Sr ₄ Si ₃ O ₈ Cl ₄ : Eu ²⁺ , Sr ₄ Al ₁₄ O ₂₄ : Eu ²⁺ , BaAl ₈ O ₁₃ : Eu ²⁺ , and Ba ₂ SiO ₄ : Eu ²⁺ . Further, BaZrSi ₃ O ₉ : Eu ²⁺ , Ca ₂ YZr ₂ (AlO ₄ ) ₃ : Ce ³⁺ , Ca ₂ YHf ₂ (AlO ₄ ) ₃ : Ce ³⁺ , and Ca ₂ YZr ₂ (AlO) ₄ ) ₃ : Ce ³⁺ , Tb ³⁺ As the green phosphor, (Y, Gd) ₃ Al ₅ O ₁₂ : Ce ³⁺ , β-SiAlON: Eu ²⁺ , SrGa ₂ S: Eu ²⁺ , Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce ³⁺ , CaSc ₂ O ₄ : Ce ³⁺ , Ba ₃ Si ₆ O ₁₂ N ₂ : Eu ²⁺ , Tb ₃ Al ₅ O ₁₂ : Eu ²⁺ , (Ba, Sr) ₂ SiO ₄ : Eu ²⁺ , Ca ₈ Mg (SiO ₄ ) ₄ Cl ₂ : Eu ²⁺ , Ca ₈ Mg (SiO ₄ ) ₄ Cl ₂ : Eu ²⁺ , Mn ²⁺ , BaMgAl ₁₀ O ₁₇ : Eu ²⁺ , Mn ²⁺ , CeMgAl ₁₁ O ₁₉ : Mn ²⁺ , Y ₃ Al ₂ (AlO ₄ ) ₃ : Ce ³⁺ , Lu ₃ Al ₂ (AlO ₄ ) ₃ : Ce ³⁺ , Y ₃ Ga ₂ (AlO ₄ ) ₃ : Ce ³⁺ , β-Si ₃ N ₄ : Eu ²⁺ , SrS i ₂ O ₂ N ₂ : Eu ²⁺ , Sr ₃ Si ₁₃ Al ₃ O ₂ N ₂₁ : Eu ²⁺ , YTbSi ₄ N ₆ C: Ce ³⁺ , SrGa ₂ S ₄ : Eu ²⁺ , Ca ₂ LaZr ₂ (AlO ₄ ) ₃ : Ce ³⁺ , Ca ₂ TbZr ₂ (AlO ₄ ) ₃ : Ce ³⁺ , Ca ₂ TbZr ₂ (AlO ₄ ) ₃ : Ce ³⁺ , Pr ³⁺ , Zn ₂ SiO ₄ : Mn ²⁺ , MgGa ₂ O ₄ : Mn ²⁺ , LaPO _{4 4} : Ce ³⁺ , Tb ³⁺ , Y ₂ SiO ₄ : Ce ³⁺ , CeMgAl ₁₁ O ₁₉ : Tb ³⁺ , and GdMgB ₅ O ₁₀ : Ce ³⁺ , Tb ³⁺ . As the yellow phosphor, Y ₃ Al ₅ O ₁₂ : Ce ³⁺ , (Y, Gd) ₃ Al ₅ O ₁₂ : Ce ³⁺ , (Ba, Sr) ₂ SiO ₄ : Eu ²⁺ , α-SiAlON, Li ₂ SrSiO ₄ : Eu ²⁺ , and (Ca, Sr, Ba, Zn) ₂ SiO ₄ : Eu ²⁺ . As yellow or orange phosphors, (Sr, Ba) ₂ SiO ₄ : Eu ²⁺ , α-Ca-SiAlON: Eu ²⁺ , Y ₂ Si ₄ N ₆ C: Ce ³⁺ , La ₃ Si ₆ N ₁₁ : Ce ³⁺ , and _{Y 3 MgAl (AlO 4) 2} (SiO 4): Ce 3+ and the like. As red phosphors, Sr ₂ Si ₅ N ₈ : Eu ²⁺ , CaAlSiN ₃ : Eu ²⁺ , SrAlSi ₄ N ₇ : Eu ²⁺ , CaS: Eu ²⁺ , La ₂ O ₂ S: Eu ³⁺ , Y ₃ Mg ₂ (AlO ₄ ) (SiO ₄ ) ₂ : Ce ³⁺ , Y ₂ O ₃ : Eu ³⁺ , Y ₂ O ₂ S: Eu ³⁺ , Y (P, V) O ₄ : Eu ³⁺ , YVO ₄ : Eu ³⁺ , 3.5MgO · 0.5MgF ₂ · GeO ₂ : Mn ⁴⁺ , K ₂ SiF ₆ : Mn ⁴⁺ , and GdMgB ₅ O ₁₀ : Ce ³⁺ , Mn ²⁺ . In addition, these fluorescent substance may be used individually by 1 type, and may be used in combination of 2 or more type.

  The second phosphor particles 6 preferably have an emission peak in a wavelength region of 490 nm or more and 560 nm or less. That is, it is preferable to use a phosphor having an emission peak in the blue-green to yellow wavelength region of 490 nm or more and 560 nm or less for the second phosphor particles 6. As described above, the wavelength conversion particle 1 uses the first phosphor particle 2 having an emission peak at 595 nm or more and 800 nm or less. Therefore, by using a phosphor having an emission peak at 490 nm or more and 560 nm or less as the second phosphor particle 6, white light with improved color rendering can be obtained.

  In the wavelength conversion member of the present embodiment, the wavelength conversion particle 1 includes a first phosphor particle 2 having an emission peak in a wavelength region of 595 nm or more and 800 nm or less, a surface of the first phosphor particle 2, and a neodymium compound. It is preferable to provide a coating 3 containing That is, it is preferable that the first phosphor particles 2 are phosphors that emit at least one of orange and red light, and the coating 3 absorbs light in the vicinity of 580 nm. The second phosphor particles 6 preferably use a blue-green to yellow phosphor having an emission peak in a wavelength region of 490 nm or more and 560 nm or less. By combining such a wavelength conversion member and, for example, a blue LED, it is possible to obtain white light with high color rendering properties. In other words, by absorbing the wavelength of light around 580 nm by the coating 3, it is possible to obtain yellow light with high color rendering properties that suppresses yellowing, makes the color of the object look clear and the skin color looks beautiful. Become.

  In the wavelength conversion member of the present embodiment, the coating 3 is provided on the surface of the second phosphor particles 6 as well as the first phosphor particles 2 to absorb light of a specific wavelength (for example, light near 580 nm). To improve color rendering. However, usually, when the color rendering is increased, the luminous efficiency is inevitably lowered. That is, when the coating 3 is formed on both the first phosphor particles 2 and the second phosphor particles 6, the color rendering property is improved, but the light emission efficiency may be lowered. Specifically, when both the first phosphor particle 2 and the second phosphor particle 6 are coated to cut light of, for example, around 580 nm, the excitation light of the first phosphor particle that emits long wavelength light and In addition to the loss of emitted light, a loss of emitted light of the second phosphor particles 6 that emit short wavelength light occurs. Therefore, the light emission efficiency of the wavelength conversion material may be reduced.

  Therefore, in the wavelength conversion member of this embodiment, it is most preferable to form the coating 3 only on the first phosphor particles 2 that emit long wavelength light. That is, by selectively coating only the first phosphor particles 2 that emit long-wavelength light, the cut-off loss of light emitted by the second phosphor particles can be suppressed, and the light emission efficiency can be increased. Furthermore, since a film is formed only on the first phosphor particles 2, it is possible to improve color rendering.

<Translucent medium>
As shown in FIG. 1, the wavelength conversion member 10 includes the above-described wavelength conversion particles 1 and second phosphor particles 6. Furthermore, it is preferable that the wavelength conversion member 10 of the present embodiment includes a translucent medium 7 in which the wavelength conversion particles 1 and the second phosphor particles 6 are dispersed. Thus, by dispersing the wavelength conversion particles 1 and the second phosphor particles 6 in the translucent medium 7, the chemical stability and heat resistance of the wavelength conversion particles 1 and the second phosphor particles 6 are improved. It becomes possible. In addition, by using the translucent medium 7, it is possible to improve the formability and handling properties when used in a lighting device.

  The translucent medium preferably contains at least one of silicone resin and glass. These materials are excellent in heat resistance and light resistance, particularly durability to light having a short wavelength such as blue to ultraviolet light. Therefore, even if the excitation light incident on the wavelength conversion particle 1 and the second phosphor particle 6 is light in a wavelength region ranging from general blue light to ultraviolet light, deterioration of the translucent medium 7 is suppressed. The

  Examples of the silicone resin include composite resins produced by crosslinking an organosiloxane hydrolysis condensate, an organosiloxane condensate, or the like by a known polymerization technique. As the polymerization method, addition polymerization such as hydrosilylation or radical polymerization can be used.

  Further, as the translucent medium 7, for example, an acrylic resin or an organic / inorganic hybrid material formed by mixing and bonding an organic component and an inorganic component at a nanometer level or a molecular level may be employed. Good.

  The total content of the wavelength conversion particle 1 and the second phosphor particle 6 in the wavelength conversion member 10 is the type of the wavelength conversion particle 1, the second phosphor particle 6 and the translucent medium 7, the size of the wavelength conversion member 10, In addition, the wavelength conversion member 10 is appropriately determined in consideration of the wavelength conversion capability required for the wavelength conversion member 10. However, the total content of the wavelength conversion particles 1 and the second phosphor particles 6 in the wavelength conversion member 10 is preferably in the range of 2% by mass to 20% by mass, for example.

  When the wavelength conversion member 10 is irradiated with excitation light from the outside, the wavelength conversion particles 1 and the second phosphor particles 6 absorb the excitation light and emit fluorescence having a wavelength longer than that of the excitation light. That is, when the excitation light passes through the wavelength conversion member 10, the wavelength of the excitation light is converted by the wavelength conversion particles 1 and the second phosphor particles 6. And in the wavelength conversion member 10 of this embodiment, since the specific wavelength which reduces color rendering property is absorbed, it becomes possible to obtain white light with high color rendering property.

[Lighting device]
Next, the illumination device according to the present embodiment will be described. The illuminating device of this embodiment is provided with the said wavelength conversion member, It is characterized by the above-mentioned. As described above, the wavelength conversion member of the present embodiment emits high color rendering fluorescence. For this reason, in the illuminating device of this embodiment, it becomes possible to output the color tone-controlled fluorescence by combining the wavelength conversion member and the excitation source that excites the wavelength conversion member.

  In addition, the illuminating device of this embodiment broadly includes electronic devices having a function of emitting light, and is not particularly limited as long as it is an electronic device that emits some light. That is, the illuminating device of this embodiment is an illuminating device that uses at least the wavelength conversion member of this embodiment and further uses at least the fluorescence emitted by the wavelength conversion member as output light.

  If it demonstrates in detail, the illuminating device of this embodiment will combine the wavelength conversion member 10, the wavelength conversion particle | grains 1 of the wavelength conversion member 10, and the excitation source which excites the 2nd fluorescent substance particle 6. FIG. And the wavelength conversion particle | grains 1 and the 2nd fluorescent substance particle 6 in the wavelength conversion member 10 absorb the energy which an excitation source emits, and convert the absorbed energy into fluorescence by which color tone control was carried out. The excitation source may be appropriately selected from a discharge device, an electron gun, a solid light emitting element, and the like according to the excitation characteristics of the wavelength conversion particle 1 and the second phosphor particle 6.

  Conventionally, there are many illuminating devices that use wavelength conversion members, such as fluorescent lamps, electron tubes, plasma display panels (PDP), white LEDs, and detection devices that use wavelength conversion members. In a broad sense, an illumination light source, an illumination device, and a display device that use a wavelength conversion member are also illumination devices, and a projector including a laser diode, a liquid crystal display including an LED backlight, and the like are also considered as illumination devices. Here, since the illuminating device of this embodiment can be classified according to the type of fluorescence emitted by the phosphor in the wavelength conversion member, this classification will be described.

  Fluorescence phenomena used in electronic devices are academically divided into several categories, and are distinguished by terms such as photoluminescence, cathodoluminescence, and electroluminescence. “Photoluminescence” refers to fluorescence emitted by a phosphor when the phosphor is irradiated with electromagnetic waves. Note that the term “electromagnetic wave” collectively refers to X-rays, ultraviolet rays, visible light, infrared rays, and the like. “Cathodeluminescence” refers to fluorescence emitted by a phosphor when the phosphor is irradiated with an electron beam. “Electroluminescence” refers to fluorescence emitted when electrons are injected into a wave phosphor or an electric field is applied. In principle, there is also a term “thermoluminescence” as fluorescence close to photoluminescence, which means fluorescence emitted by the phosphor when heat is applied to the phosphor. In addition, there is also the term “radioluminescence” as fluorescence close to cathodoluminescence in principle. This means fluorescence emitted from the phosphor when the phosphor is irradiated with radiation.

  As described above, the illumination device according to the present embodiment uses at least the fluorescence emitted from the wavelength conversion particles 1 and the second phosphor particles 6 in the wavelength conversion member 10 as output light. Since the fluorescence here can be classified at least as described above, the fluorescence can be replaced with at least one fluorescence phenomenon selected from the luminescence.

  Typical examples of lighting devices that use photoluminescence of phosphors as output light include X-ray image intensifiers, fluorescent lamps, white LEDs, semiconductor laser projectors that use phosphors and laser diodes, and PDPs. . Further, typical examples of an illumination device that uses cathodoluminescence as output light include an electron tube, a fluorescent display tube, and a field emission display (FED). Furthermore, typical examples of a lighting device that uses electroluminescence as output light include an inorganic electroluminescence display (inorganic EL), a light emitting diode (LED), a semiconductor laser (LD), and an organic electroluminescence element (OLED).

  Hereinafter, the illumination device of the present embodiment will be described with reference to the drawings. FIG. 4 shows an outline of the illumination device according to the present embodiment. 4A and 4B, the excitation source 20 is a light source that generates primary light for exciting the wavelength conversion particles 1 and the second phosphor particles 6 in the wavelength conversion member 10 of the present embodiment. It is. The excitation source 20 is a radiation device that emits electromagnetic waves such as particle beams such as α-rays, β-rays, electron beams, γ-rays, X-rays, vacuum ultraviolet rays, ultraviolet rays, and visible light (especially violet light short-wavelength visible light). Can be used. As the excitation source 20, various radiation generators, electron beam emitters, discharge light generators, solid state light emitting devices, solid state lighting devices, and the like can be used. Typical examples of the excitation source 20 include an electron gun, an X-ray tube, a rare gas discharge device, a mercury discharge device, a light emitting diode, a laser light generator including a semiconductor laser, an inorganic or organic electroluminescence element, and the like. It is done.

  4A and 4B, the output light 40 is excitation light emitted by the excitation source 20 or fluorescence emitted by the wavelength conversion particles 1 and the second phosphor particles 6 excited by the excitation light 30. is there. The output light 40 is used as illumination light or display light in the illumination device.

  FIG. 4A shows an illuminating device having a structure in which output light 40 from the wavelength conversion member 10 is emitted in a direction in which the wavelength conversion member 10 is irradiated with excitation rays or excitation light 30. In addition, as a illuminating device shown to Fig.4 (a), a white LED light source, a fluorescent lamp, an electron tube, etc. are mentioned. On the other hand, FIG. 4B shows an illuminating device having a structure in which the output light 40 from the wavelength conversion member 10 is emitted in a direction opposite to the direction in which the wavelength conversion member 10 is irradiated with excitation rays or excitation light 30. . Examples of the illumination device shown in FIG. 4B include a plasma display device, a light source device using a wavelength conversion member wheel with a reflector, and a projector.

  Preferable specific examples of the illuminating device of the present embodiment are a semiconductor illuminating device, an illuminating light source, an illuminating device, a liquid crystal panel with an LED backlight, an LED projector, a laser projector and the like configured using a wavelength conversion member. And it is preferable that the illuminating device of this embodiment has a structure which excites a wavelength conversion member with visible light or ultraviolet light. As the wavelength range of the excitation light, those having a maximum intensity value in the range of 440 nm to 500 nm can be preferably used. Furthermore, it is preferable that the lighting device further includes a solid-state light emitting element that emits short-wavelength visible light. By using a solid-state light-emitting element as an excitation source, it is possible to realize an all-solid-state lighting device that is resistant to impact, for example, solid-state lighting.

  Hereinafter, a specific example of the semiconductor lighting device according to the present embodiment will be described in detail. As shown in FIG. 5, the semiconductor lighting device 100 according to the present embodiment includes a substrate 110, a plurality of LEDs (light emitting elements) 120, and a plurality of sealing members 130. The substrate 110 has, for example, a two-layer structure of an insulating layer made of a ceramic substrate or a heat conductive resin and a metal layer made of an aluminum plate. The substrate 110 has a substantially rectangular plate shape, and the width W1 in the short direction (X-axis direction) of the substrate 110 is 12 to 30 mm, and the width W2 in the longitudinal direction (Y-axis direction) is 12 to 30 mm.

  As shown in FIGS. 6A and 6B, the LED 120 is a GaN-based LED, for example, and has a substantially rectangular shape in plan view. The LED 120 has a width W3 in the lateral direction (X-axis direction) of 0.3 to 1.0 mm, a width W4 in the longitudinal direction (Y-axis direction) of 0.3 to 1.0 mm, and a thickness (in the Z-axis direction). (Width) is 0.08 to 0.30 mm.

  The LEDs 120 are arranged such that the longitudinal direction (Y-axis direction) of the substrate 110 coincides with the arrangement direction of the element rows of the LEDs 120. The LEDs 120 constitute an element array for each of the plurality of LEDs 120 arranged in a line, and the element arrays are mounted in a plurality of rows along the short direction (X-axis direction) of the substrate 110. Specifically, for example, 25 LEDs 120 are mounted in a matrix with 5 columns and 5 rows. That is, one element row is composed of five LEDs, and such element rows are mounted side by side.

  In each element row, the LEDs 120 are linearly arranged in the longitudinal direction (Y-axis direction). Thus, by arranging the LEDs 120 in a straight line, the sealing member 130 for sealing the LEDs 120 can also be formed in a straight line.

  As shown in FIG. 6B, each element row is individually sealed by a long sealing member 130. One light emitting unit 101 is configured by one element row and one sealing member 130 that seals the element row. Therefore, the semiconductor lighting device 100 includes the five light emitting units 101.

The sealing member 130 is formed by the wavelength conversion member 10 described above. However, the phosphor contained in the wavelength conversion member 10 is activated not only by the wavelength conversion particle 1 and the second phosphor particle 6 but also by, for example, at least one of Eu ²⁺ , Ce ³⁺ , Tb ³⁺ , and Mn ^2+. Oxide-based phosphors such as oxides and acid halides can also be used. In addition, as phosphors, nitride phosphors such as nitrides and oxynitrides activated by at least one of Eu ²⁺ , Ce ³⁺ , Tb ³⁺ and Mn ²⁺ , or sulfides such as sulfides and oxysulfides are used. Physical phosphors can also be used. Also, the above-described blue phosphor, green blue or blue green phosphor, green phosphor, yellow or orange phosphor, and red phosphor can be used.

  As shown in FIG. 6, the sealing member 130 has a width W5 in the lateral direction (X-axis direction) of 0.8 to 3.0 mm, and a width W6 in the longitudinal direction (Y-axis direction) of 3.0 to 40. It is preferably 0 mm. Moreover, it is preferable that the maximum thickness (width in the Z-axis direction) T1 including the LED 120 is 0.4 to 1.5 mm, and the maximum thickness T2 not including the LED 120 is 0.2 to 1.3 mm. In order to ensure sealing reliability, the width W5 of the sealing member 130 is preferably 2 to 7 times the width W3 of the LED 120.

  The cross-sectional shape of the sealing member 130 along the short direction is substantially semi-elliptical as shown in FIG. Further, both end portions 131 and 132 in the longitudinal direction of the sealing member 130 have an R shape. Specifically, as shown in FIG. 5, the shape of both end portions 131 and 132 is a substantially semicircular shape in plan view, and the cross-sectional shape along the longitudinal direction as shown in FIG. Is substantially fan-shaped with a central angle of about 90 °. When both end portions 131 and 132 of the sealing member 130 are formed in an R shape in this way, stress concentration is unlikely to occur at the both end portions 131 and 132, and the emitted light from the LED 120 is taken out of the sealing member 130. easy.

  Each LED 120 is mounted face up on the substrate 110. The wiring pattern 140 formed on the substrate 110 is electrically connected to a lighting circuit unit (not shown) that supplies power to the LED 120. The wiring pattern 140 includes a pair of power feeding lands 141 and 142 and a plurality of bonding lands 143 arranged at positions corresponding to the respective LEDs 120.

  As shown in FIG. 6, the LED 120 is electrically connected to the land 143 through a wire (for example, a gold wire) 150 by, for example, wire bonding. One end 151 of the wire 150 is bonded to the LED 120, and the other end 152 is bonded to the land 143. Each wire 150 is arranged along an element row to which a light emitting element to be connected belongs. Furthermore, both end portions 151 and 152 of each wire 150 are also arranged along the element row. Since each wire 150 is sealed by the sealing member 130 together with the LED 120 and the land 143, the wire 150 is hardly deteriorated, and is insulated and highly safe. In addition, the mounting method of LED120 to the board | substrate 110 is not limited to the above face-up mounting, Flip chip mounting may be sufficient.

  As shown in FIG. 5, the LED 120 includes five LEDs 120 belonging to the same element row connected in series, and five element rows connected in parallel. In addition, the connection form of LED120 is not limited to this, You may connect how regardless of an element row | line | column. A pair of lead wires of a lighting circuit unit (not shown) is connected to the lands 141 and 142, and power is supplied from the lighting circuit unit to the LEDs 120 via the lead wires, whereby each LED 120 emits light.

  The sealing member 130 can be formed by the following procedure. First, as illustrated in FIG. 5, a substrate 110 is prepared on which a plurality of element arrays each including a plurality of LEDs 120 arranged in a line are arranged in the X-axis direction. Next, as illustrated in FIG. 7, a resin paste 135 is applied to the substrate 110 in a line shape along the element rows using, for example, a dispenser 160. Thereafter, the sealing member 130 is individually formed for each element row by solidifying the resin paste 135 after application.

  The semiconductor lighting device of this embodiment can be widely used for illumination light sources, backlights for liquid crystal displays, and light sources for display devices. That is, as described above, the wavelength conversion particles and the second phosphor particles in the wavelength conversion member of the present embodiment can emit light with good visibility. Therefore, when the wavelength conversion member is used for an illumination light source or the like, it is possible to provide an illumination light source with high color rendering properties and high efficiency, and a display device capable of displaying a wide color gamut on a high luminance screen.

  Such an illumination light source can be configured by combining the semiconductor illumination device of the present embodiment, a lighting circuit for operating the semiconductor illumination device, and a connection component for a lighting fixture such as a base. Moreover, if a lighting fixture is combined as needed, it will also comprise an illuminating device and an illumination system.

  As described above, the illumination device of the present embodiment has excellent characteristics in terms of visibility and visibility, and thus can be widely used in addition to the above-described semiconductor illumination device and light source device.

  Hereinafter, the present embodiment will be described in more detail with reference to examples and comparative examples, but the present embodiment is not limited to these examples.

[Preparation of red phosphor coated with neodymium oxide]
1000 parts by mass of ethanol, 50 parts by mass of CASN phosphor ((Ca, Sr) AlSiN ₃ : Eu ³⁺ ), 10 parts by mass of neodymium oxide powder (manufactured by Wako Pure Chemical Industries, Ltd.), and a hydrolysis condensate of tetraethoxysilane 1 part by mass was mixed. And the phosphor slurry was prepared by stirring the said mixture with a magnetic stirrer for 2 hours. The hydrolyzed condensate of tetraethoxysilane is obtained by dissolving tetraethoxysilane in alcohol and adding an acid catalyst to cause hydrolysis and dehydration condensation.

Next, the phosphor slurry is filtered with suction using filter paper, washed with ethanol, and then heat treated at 500 ° C. for 1 hour to obtain a CASN phosphor coated with a coating made of Nd ₂ O ₃ and silica. It was.

[Preparation of yellow phosphor coated with neodymium oxide]
1000 parts by mass of ethanol, 50 parts by mass of YAG phosphor (Y ₃ Al ₅ O ₁₂ : Ce ³⁺ ), 10 parts by mass of neodymium oxide powder (manufactured by Wako Pure Chemical Industries, Ltd.), and hydrolyzed condensate 1 of tetraethoxysilane Mass parts were mixed. And the phosphor slurry was prepared by stirring the said mixture with a magnetic stirrer for 2 hours. The hydrolyzed condensate of tetraethoxysilane is obtained by dissolving tetraethoxysilane in alcohol and adding an acid catalyst to cause hydrolysis and dehydration condensation.

Next, the phosphor slurry is filtered with suction using filter paper, washed with ethanol, and then heat treated at 500 ° C. for 1 hour to obtain a YAG phosphor coated with a coating made of Nd ₂ O ₃ and silica. It was.

[Example 1]
The coated CASN phosphor obtained as described above and the YAG phosphor without a coating (Y ₃ Al ₅ O ₁₂ : Ce ³⁺ ) are dispersed in a silicone resin as a translucent medium, and a sealing member is formed. Prepared. And the said sealing member and the blue light emitting diode were combined, and the semiconductor light-emitting device was produced. In this example, the concentration and ratio of the coated CASN phosphor and the YAG phosphor in the sealing member were adjusted so that the color temperature of the semiconductor light emitting device was 3000K.

[Example 2]
The coated CASN phosphor and the coated YAG phosphor obtained as described above were dispersed in the silicone resin of Example 1 to prepare a sealing member. And the said sealing member and the blue light emitting diode were combined, and the semiconductor light-emitting device was produced. In this example, the concentration and ratio of the coated CASN phosphor and the coated YAG phosphor in the sealing member were adjusted so that the color temperature of the semiconductor light emitting device was 3000K.

[Comparative example]
A CASN phosphor ((Ca, Sr) AlSiN ₃ : Eu ³⁺ ), a YAG phosphor (Y ₃ Al ₅ O ₁₂ : Ce ³⁺ ), and neodymium oxide powder are dispersed in the silicone resin of Example 1 and sealed. A stop member was prepared. And the said sealing member and the blue light emitting diode were combined, and the semiconductor light-emitting device was produced. In this example, the concentrations and ratios of the CASN phosphor and the YAG phosphor in the sealing member were adjusted so that the color temperature of the semiconductor light emitting device was 3000K. Moreover, the neodymium oxide powder was adjusted to be the same as the content of neodymium oxide in Example 1.

[Measurement of luminous efficiency]
The produced semiconductor light emitting device was turned on, and the total luminous flux was measured using an integrating sphere. And luminous efficiency (lm / W) was calculated | required from the measured total light flux (lm) and input electric power (W). However, in this example, in order to make the comparison easier to understand, the efficiency of Comparative Example 1 was set as 100, and the relative light emission efficiency was compared.

[Measurement of color rendering index Ra]
Using an instantaneous multi-photometry system (MCPD, manufactured by Otsuka Electronics Co., Ltd.), an emission spectrum of light emitted from the produced semiconductor light emitting device was measured. The average color rendering index Ra was calculated from the obtained emission spectrum using the attached software.

[Measurement of conspicuous index FCI]
In accordance with the method described in Patent Document 4, the conspicuous index FCI was measured.

  Table 1 shows the measurement results of the luminous efficiency, the color rendering index Ra, and the conspicuous index FCI in each example and comparative example. The luminous efficiency is shown as a relative value when the comparative example is 100. Further, when the conspicuous index exceeds 100, there is a property that the color is rendered vividly to make the space feel bright.

  As shown in Table 1, Examples 1 and 2 and Comparative Example show substantially the same values for the color rendering index Ra and the conspicuous index FCI, and it can be confirmed that the color rendering properties are high. Moreover, compared with the comparative example, luminous efficiency is improved in Examples 1 and 2. In the comparative example, neodymium oxide powder is directly dispersed in the sealing member, whereas in the example, the CASN phosphor is directly coated. For this reason, it is possible to effectively absorb light in the vicinity of 580 nm in the radiated light from the CASN phosphor, and to improve the color rendering while suppressing a decrease in light emission efficiency.

  As mentioned above, although this embodiment was described by the Example, this embodiment is not limited to these, A various deformation | transformation is possible within the range of the summary of this embodiment.

DESCRIPTION OF SYMBOLS 1 Wavelength conversion particle 2 1st fluorescent substance particle 3 Coating 6 Second fluorescent substance particle 7 Translucent medium 10 Wavelength conversion member 100 Semiconductor lighting device

Claims (7)

First phosphor particles having an emission peak in a wavelength region of 595 nm or more and 800 nm or less, and covers the surface of the first phosphor particles, and absorbs light of a specific wavelength among the light emitted by the first phosphor particles. A wavelength converting particle comprising a coating;
A second phosphor particle having an emission peak on the short wavelength side of the first phosphor particle;
A wavelength conversion member comprising:   The wavelength conversion member according to claim 1, wherein the coating contains a neodymium compound that absorbs light of the specific wavelength.   The wavelength conversion member according to claim 1 or 2, wherein the thickness of the coating is 10 nm or more and 1 µm or less.   The wavelength conversion member according to any one of claims 1 to 3, wherein the second phosphor particles have an emission peak in a wavelength region of 490 nm or more and 560 nm or less.   The wavelength conversion member according to any one of claims 1 to 4, further comprising a translucent medium in which the wavelength conversion particles and the second phosphor particles are dispersed.   The wavelength conversion member according to claim 5, wherein the translucent medium contains at least one of silicone resin and glass.   An illuminating device provided with the wavelength conversion member as described in any one of Claims 1 thru | or 6.