JP4380118B2 - LIGHT EMITTING DEVICE AND LIGHTING DEVICE USING THE SAME - Google Patents

Description

【００４８】
【発明の効果】
本発明によれば、演色性が高く、かつ発光強度の高い発光装置を提供することができる。
【図面の簡単な説明】
【図１】 Ca₃Mg₃(PO₄)₄のＸ線回折パターン(Ｘ線源Cu Kαに換算したもの)。
【図２】 面発光型ＧａＮ系ダイオードに膜状の第２の発光体を接触又は成型させた発光装置の一例を示す図。
【図３】 本発明中の、第１の発光体（３５０ｎｍ〜４１５ｎｍの光を発生する発光体）と第２の発光体とから構成される発光装置の一実施例を示す模式的断面図である。
【図４】 本発明の照明装置の一例を示す模式的断面図。
【図５】 実施例１の蛍光体のＸ線回折パターン（Ｘ線源：Cu Kα）
【図６】 発光波長４００ｎｍのＧａＮ系発光ダイオードにより照射を受けた実施例１、および比較例１のそれぞれの蛍光体の発光スペクトルを重ね合わせたスペクトル。
【図７】 実施例２の蛍光体のＸ線回折パターン(Ｘ線源：Cu Kα)
【図８】 実施例４の蛍光体のＸ線回折パターン(Ｘ線源：Cu Kα)
【符号の説明】
１；第２の発光体
２；面発光型ＧａＮ系ＬＥＤ
３；基板
４；発光装置
５；マウントリード
６；インナーリード
７；第１の発光体（３５０ｎｍ〜４１５ｎｍの光を発生する発光体）
８；蛍光体含有樹脂部
９；導電性ワイヤー
１０；モールド部材
１１；発光装置を組み込んだ面発光照明装置
１２；保持ケース
１３；発光装置
１４；拡散板[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a light-emitting device, and more specifically, a first light emitter that emits light from ultraviolet light to visible light region by a power source, and absorbs light in the visible light region from the ultraviolet light to generate long-wavelength visible light. By combining with a second phosphor as a wavelength conversion material having a phosphor containing a phosphor containing a luminescent center ion as a base compound that emits light, color rendering is good regardless of the usage environment and high intensity light emission is generated. The present invention relates to a light-emitting device that can be used.
[0002]
[Prior art]
  In order to generate white and other various colors by mixing blue, red, and green, a light emitting device in which the light emission color of an LED or LD is color-converted with a phosphor has been proposed.
  For example, in Japanese Examined Patent Publication No. 49-1221, 300nm ~A laser beam emitting a radiation beam with a wavelength of 530 nm is converted into a phosphor (Y_3-xyCe_xGd_yM_5-zGa_zO₁₂(Y represents Y, Lu, or La, M represents Al, Al—In, or Al—Sc, x is 0.001 to 0.15, y is 2.999 or less, and z is 3.0 or less. ))) And illuminating it to form a display. Further, in recent years, a white light emitting device configured by combining a gallium nitride (GaN) LED or LD with high luminous efficiency, which has been attracting attention as a blue light emitting semiconductor light emitting element, and a phosphor as a wavelength conversion material. However, it has been proposed as a light-emitting source for an image display device and a lighting device, taking advantage of the feature of low power consumption and long life. Actually, Japanese Patent Laid-Open No. 10-242513 discloses a light emitting device using the nitride semiconductor LED or LD chip and using a cerium-activated yttrium / aluminum / garnet system as a phosphor. Has been.
[0003]
  However, cerium-activated yttrium / aluminum / garnet phosphors such as those disclosed in Japanese Patent Publication No. 49-1221 and Japanese Patent Application Laid-Open No. 10-242513 are used as the second light emission for the first light emitters of LEDs and lasers. A light-emitting device combined as a body does not satisfy both high light emission intensity and color rendering properties, and further improvements are required as light-emitting sources such as displays, backlight light sources, and traffic lights.
[0004]
  The color rendering property represents a scale representing how close the color appearance of an object illuminated with sunlight is to the color appearance of an object illuminated with white light from a phosphor.
  For example, in the combination of a cerium activated yttrium / aluminum / garnet phosphor and a blue LED or a blue laser as disclosed in JP-A-10-242513, a mixture of blue light and yellow light generated from the phosphor is used. A white color can be generated, but an intermediate region (470) between the blue and yellow emission peak tops (near 450 nm and near 550 nm).nm ~540 nm) and the long wavelength side region of the yellow peak (580nm ~700 nm) is extremely small, and a valley is generated in the light emission in the region, so that it cannot be matched with the sunlight spectrum without a valley in the region. Therefore, the color rendering properties are extremely low.
[0005]
  On the other hand, when the blue, green, and red phosphors are mixed to obtain white light, the two peaks overlap instead of the conventional blue / yellow mixed color system. The valley between the emission peaks is reduced, and the color rendering properties are further improved. However, even in this blue / green / red mixed color system, there is a problem that the color rendering is lowered due to the existence of a valley between emission peaks.
[0006]
[Problems to be solved by the invention]
  When blue, green, and red phosphors are mixed to produce white light, each color phosphor is required to have high emission intensity and high color rendering.
  The present invention has been made in view of the above-described prior art, and is intended to develop a light emitting device that not only has high light emission intensity but also high color rendering properties, and is easy to manufacture and has both color rendering properties and light emission intensity. An object of the present invention is to provide a light-emitting device having a high brightness, particularly a light-emitting device suitable as a blue phosphor.
[0007]
[Means for Solving the Problems]
  As a result of intensive studies to solve the above-mentioned problems, the present inventors irradiate phosphors with light of 350 nm to 415 nm to emit blue, green, and red, and to emit white light by mixing blue, green, and red. In the method, as a means for obtaining high color rendering properties, a phosphor having a light emission peak with a very large wavelength-intensity distribution width, particularly a blue phosphor, has an intermediate region (470 between blue and green in the emission spectrum).nm ~500 nm) using a blue phosphor that has sufficient intensity, that is, generates a blue emission peak with a large half-value width.nm ~The inventors have found that the object can be achieved by using an orthophosphate of Ca or Ca-Mg, which can reduce the valley of the emission intensity in the 500 nm region and can improve the color rendering properties, and has reached the present invention.
[0008]
  That is, the present invention400In the light emitting device having a first light emitter that generates light of nm to 415 nm and a second light emitter that generates visible light by irradiation of light from the first light emitter, the second light emitter The gist of the present invention is a light emitting device comprising a phosphor having a crystal phase having the following specific chemical composition.
[0009]
[Chemical formula 2]
          Eu_aM_b(PO_Four)_c(BO_Three)_2-cZ_d[1]
(In the above general formula [1], M represents a metal element containing Ca and at least one element selected from the group consisting of Ca and Mg occupying 80 mol% or more, and Z represents PO._Four ^3-, BO_Three ^3-Represents an anion other than a is0.15≦ a ≦ 2.1, b is 2.7 ≦ (a + b) ≦ 3.3, c is a number satisfying 1.2 ≦ c ≦ 2, and d is a number satisfying 0 ≦ d ≦ 0.1. )
[0010]
  That is, the feature of the present invention is orthophosphate A_Three(PO_Four)₂Eu (where A is an alkaline earth metal)²⁺The material activated by the above is known as a normal 254 nm excitation phosphor, but the emission intensity generated by excitation of light in the vicinity of 400 nm and the half width of the emission peak, which have not been studied so far, are , A_Three(PO_Four)₂Depending on the type of alkaline earth metal AThatThis A_Three(PO_Four)₂: Eu²⁺Of these, a substance having Ca or Ca—Mg composite cation as A is 350nm ~When irradiated with 415 nm excitation light, it emits very intense blue light, and the emission wavelength-emission intensity distribution that greatly enhances the color rendering properties is wide, that is, the half width is large, and the phosphor gives high color rendering properties. It is based on knowing that.
DETAILED DESCRIPTION OF THE INVENTION
[0011]
  Hereinafter, the present invention will be described in detail.
  The present invention400A light-emitting device in which a first light-emitting body that generates light of nm to 415 nm and a second light-emitting body that is a phosphor are combined, and the second light-emitting body has a chemical composition represented by the following general formula [1] It contains a phosphor having a crystal phase.
[0012]
[Chemical 3]
          Eu_aM_b(PO_Four)_c(BO_Three)_2-cZ_d[1]
(In the above general formula [1], M represents a metal element containing Ca and at least one element selected from the group consisting of Ca and Mg occupying 80 mol% or more, and Z represents PO._Four ^3-, BO_Three ^3-Represents an anion other than a is0.15≦ a ≦ 2.1, b is 2.7 ≦ (a + b) ≦ 3.3, c is a number satisfying 1.2 ≦ c ≦ 2, and d is a number satisfying 0 ≦ d ≦ 0.1. )
[0013]
  Here, Eu in the general formula [1]²⁺The molar ratio a is from the viewpoint of color rendering properties and emission intensity.GoodPreferably0.15The upper limit is 2.1 or less, preferably 1 or less. Eu, the luminescent center ion²⁺If the content of is too small, the emission intensity tends to be low, while if too high, the emission intensity tends to decrease due to a phenomenon called concentration quenching.
[0014]
  The element M in the formula [1] represents a monovalent or higher element different from Eu, P, and B. As for the element M, it is preferable that M contains Ca and the ratio of the total of Ca and Mg to the element M is 80 mol% or more from the viewpoint of color rendering properties and light emission intensity. More preferably, the ratio of Ca to 40 mol% or more is more preferable, M is at least one element selected from the group consisting of Ca and Mg, and it is more preferable that Ca is contained in an amount of 40 mol% or more.
[0015]
  When a metal element other than Ca and Mg is contained in the crystal as a metal element in M, the metal element is not particularly limited, but the same valence as Ca and Mg, that is, a divalent metal element such as Sr and Zn. , Ba, Pb, Sn, preferably Sr, Zn, Ba, is desirable because the crystal structure is easily retained. These divalent metal elements and the emission center Eu²⁺Even if a small amount of a metal element such as monovalent, trivalent, tetravalent, pentavalent, or hexavalent is introduced as a metal element in M in order to help crystallization of the composite oxide by diffusion in the solid during firing of good. For example, Eu_0.15Ca_2.85(PO_Four)₂Ca in the phosphor²⁺A portion of the equimolar Li⁺And Ga³⁺Thus, the replacement can be performed while maintaining the charge compensation effect. In order to adjust the emission wavelength and emission intensity, a small amount of a metal element that can be a sensitizer such as Mn may be substituted.
[0016]
  Basic crystal Eu of the general formula [1]_aM_b(PO_Four)_c(BO_Three)_2-cZ_d, The basic cation stoichiometric molar ratio (a + b) when Z is ignored as an impurity is 3. However, even if some cation deficiency or anion deficiency occurs, there is no significant effect on the fluorescence performance for this purpose. Therefore, it can be used in the range of 2.7 ≦ (a + b) ≦ 3.3.
[0017]
  In the general formula [1], the main anion is PO._FourGroup and BO_ThreeThe total molar ratio of groups is expressed as 2. In terms of color rendering properties and light emission intensity, PO in a total molar ratio of 2_FourThe molar ratio of groups is preferably at least 1.2 or more, and preferably 1.6 or more and 2 or less. BO_ThreeThe presence of the group does not have a great adverse effect on the color rendering properties and emission intensity. PO in the general formula [1]_FourGroup and BO_ThreeThe anion Z other than the group is preferably as small as possible, but may be contained as long as the amount of the anion Z has little influence on the fluorescence performance for this purpose. An amount of .05 or less is preferred.
  The anion Z includes hydroxide ions (OH^-), Metal oxide anions, halide ions, etc., and examples of metal oxide anions include SiO_Four ^Four-, SiO_Three ^2-TiO_Three ^2-, ZrO_Three ^2-As halide ions, F^-, Cl^-, Br^-, I^-However, it is not limited to these.
[0018]
  Used in the present inventionIt has a crystal phase having a chemical composition represented by the general formula [1]The phosphor is M source, PO_FourSource, BO_ThreeSource compound and luminescent center ion (Eu²⁺M and Eu source compounds include hydrogen phosphates, phosphates, oxides, hydroxides, carbonates, nitrates, sulfates, oxalic acids of M and Eu. Examples thereof include salts, carboxylates, halides, etc. Among them, hydrogen phosphates, phosphates, oxides and carbonates of M and Eu are preferable.
  PO_FourSource compounds include elements M, Eu, NH_FourSuch as hydrogen phosphate, phosphate, metaphosphate, pyrophosphate, etc.₂O_Five, Phosphoric acid, metaphosphoric acid, pyrophosphoric acid, etc., among which elements M, Eu, NH_FourPreferred are hydrogen phosphate, phosphate, and phosphoric acid.
  BO_ThreeSource compounds include elements M, Eu, NH_FourBorate, hydrogen borate, tetraborate, octaborate, diborate, pentaborate, etc., boric acid, boron oxide, etc., among others, elements M, Eu, NH_FourAnd borate, hydrogen borate, boric acid, and boron oxide are preferable.
  Among these, chemical composition, reactivity, and NO during firing_x, SO_xIs selected in consideration of non-occurrence of
[0019]
  Regarding the Ca, Mg, Sr, Zn, and Ba that are preferable for the metal element group M, specific examples of their M source compounds include CaHPO as the Ca source compound._Four, Ca_Three(PO_Four)₂, CaO, Ca (OH)₂, CaCO_Three, Ca (NO_Three)₂・ 4H₂O, CaSO_Four・ 2H₂O, Ca (OCO)₂・ H₂O, Ca (OCOCH_Three)₂・ H₂O, CaCl₂Etc., among others, CaHPO_Four, Ca_Three(PO_Four)₂, CaO, CaCO_ThreeIs preferred.
  As the Mg source compound, MgHPO_Four, Mg_Three(PO_Four)₂, MgO, Mg (OH)₂, MgCO_Three, Mg (OH)₂・ 3MgCO_Three・ 3H₂O, Mg (NO_Three)₂・ 6H₂O, MgSO_Four, Mg (OCO)₂・ 2H₂O, Mg (OCOCH_Three)₂・ 4H₂O, MgCl₂Among others, MgHPO_Four, Mg_Three(PO_Four)₂, MgO, MgCO_ThreeIs preferred.
  As the Sr source compound, SrHPO_Four, Sr_Three(PO_Four)₂, SrO, Sr (OH)₂・ 8H₂O, SrCO_Three, Sr (NO_Three)₂, SrSO_Four, Sr (OCO)₂・ H₂O, Sr (OCOCH_Three)₂・ 0.5H₂O, SrCl₂Among others, SrHPO_Four, Sr_Three(PO_Four)₂, SrO, SrCO_ThreeIs preferred.
  As a Zn source compound, ZnHPO_Four, Zn_Three(PO_Four)₂, ZnO, Zn (OH)₂, ZnCO_Three, Zn (NO_Three)₂Zn (OCO)₂, Zn (OCOCH_Three)₂ZnCl₂Among others, ZnHPO_Four, Zn_Three(PO_Four)₂, ZnO, ZnCO_ThreeIs preferred.
  As a Ba source compound, BaHPO_Four, Ba_Three(PO_Four)₂, BaO, Ba (OH)₂・ 8H₂O, BaCO_Three, Ba (NO_Three)₂, BaSO_Four, Ba (OCO)₂・ 2H₂O, Ba (OCOCH_Three)₂, BaCl₂Such as BaHPO_Four, Ba_Three(PO_Four)₂, BaO, BaCO_ThreeIs preferred.
[0020]
  Further, with respect to Eu, which is preferable as the element of the luminescent center ion, if the element source compound is specifically illustrated, Eu₂O_Three, Eu₂(SO_Four)_Three, Eu₂(OCO)₆, EuCl₂, EuCl_Three, EuPO_Four, Eu (NO_Three)_Three・ 6H₂O etc. are mentioned.
[0021]
  The phosphor used in the present invention includes the above-mentioned M source, PO._FourSource, BO_ThreeSource compound and luminescent center ion (Eu²⁺) After being pulverized using a dry pulverizer such as a hammer mill, roll mill, ball mill, jet mill or the like, and then mixed by a mixer such as a ribbon blender, a V-type blender or a Henschel mixer, or mixed. Then, these compounds are added into a medium such as water, and then pulverized and mixed using a wet pulverizer such as a medium agitating pulverizer. After the compound is pulverized by a dry pulverizer, the prepared pulverized mixture is heated and fired by a wet method in which a slurry prepared by adding and mixing in a medium such as water is spray-dried or the like. Can be manufactured.
[0022]
  Among these pulverization and mixing methods, in particular, in the element source compound of the luminescent center ion, it is preferable to use a liquid medium because it is necessary to uniformly mix and disperse a small amount of the compound over the whole. The latter wet method is preferable from the viewpoint of obtaining uniform mixing in the element source compound as a whole, and the heat treatment method is usually 800 ° C. in a heat-resistant container such as a crucible or tray made of alumina or quartz.℃~ 1500 ° C, preferably 1000℃By heating at a temperature of ˜1300 ° C. for 10 minutes to 24 hours, preferably 10 hours or less in a single or mixed atmosphere of gas such as air, oxygen, carbon monoxide, carbon dioxide, nitrogen, hydrogen, and argon Made. In addition, after heat processing, washing | cleaning, drying, a classification process, etc. are made | formed as needed.
[0023]
  As the heating atmosphere, an atmosphere necessary for obtaining an ion state (valence) in which the element of the emission center ion contributes to light emission is selected. In the case of divalent Eu or the like in the present invention, a neutral or reducing atmosphere such as carbon monoxide, nitrogen, hydrogen, and argon is preferable, but it can be selected even under an oxidizing atmosphere such as air and oxygen. .
[0024]
  The present inventionThe phosphor used inCrystal structureageA as shown above_Three(PO_Four)₂ConstructionHavingIt is. A_Three(PO_Four)₂There are several types of crystal structures with different space groups in the structure. (Ca, Mg)_Three(PO_Four)₂The space group of α-type Ca_Three(PO_Four)₂P2₁/ a, Ca₇Mg₂(PO_Four)₆R3c, Ca_2.86Mg_0.14(PO_Four)₂R3c, Mg_Three(PO_Four)₂P2₁/ n. Fig. 1 shows Ca_ThreeMg_Three(PO_Four)_FourX-ray diffraction pattern is shown (from powder X-ray diffraction database). A_Three(PO_Four)₂Crystal A²⁺On the site, Ba²⁺, Sr²⁺, Ca²⁺Or Mg²⁺, And Eu as an activator²⁺A divalent metal element such as can be substituted. In the present invention, A_Three(PO_Four)₂: Among Eu, those in which A is Ca or a Ca—Mg mixed system are targeted.
[0025]
  The phosphor used in the present invention is 350 from the first light emitter.nm ~Excited by 415 nm light to generate visible light. The phosphor is 350nm ~Excitation of light at 415 nm generates visible light having good color rendering properties and strong emission intensity, and emits fluorescence with high color rendering properties and high luminance particularly by excitation light around 400 nm emitted from a GaN-based semiconductor.
[0026]
  In the present invention, the first light emitter that irradiates the phosphor with light has a wavelength of 350.nm ~Generates 415 nm light. Preferably wavelength 350nm ~A light emitter that generates light having a peak wavelength in the range of 415 nm is used. Specific examples of the first light emitter include a light emitting diode (LED) or a laser diode (LD). A laser diode is more preferable because it consumes less power. Of these, GaN LEDs and LDs using GaN compound semiconductors are preferred. This is because GaN-based LEDs and LDs have significantly higher light emission output and external quantum efficiency than SiC-based LEDs that emit light in this region, and are extremely bright with very low power when combined with the phosphor. This is because light emission can be obtained. For example, for a current load of 20 mA, the GaN system usually has a light emission intensity 100 times or more that of the SiC system. In GaN LED and LD, Al_XGa_YN light emitting layer, GaN light emitting layer, or In_XGa_YThose having an N light emitting layer are preferred. Among GaN-based LEDs, In_XGa_YThose having an N light emitting layer are particularly preferred because the light emission intensity is very strong._XGa_YA multi-quantum well structure of an N layer and a GaN layer is particularly preferable because the emission intensity is very strong. In the above, the value of X + Y is usually in the range of 0.8 to 1.2. In the GaN-based LED, those in which the light emitting layer is doped with Zn or Si or those without a dopant are preferable for adjusting the light emission characteristics. GaN-based LEDs have these light-emitting layers, p-layers, n-layers, electrodes, and substrates as basic components, and the light-emitting layers are made of n-type and p-type Al._XGa_YN layer, GaN layer, or In_XGa_YThose having a heterostructure sandwiched between N layers and the like have high luminous efficiency, and those having a heterostructure having a quantum well structure further have high luminous efficiency, and are more preferable.
[0027]
  In the present invention, it is particularly preferable to use a surface-emitting type illuminant, particularly a surface-emitting GaN-based laser diode, as the first illuminant because the luminous efficiency of the entire light-emitting device is increased. A surface-emitting type illuminant is an illuminant that emits strong light in the surface direction of a film. In a surface-emitting GaN-based laser diode, the crystal growth of a light-emitting layer or the like is controlled, and a reflective layer or the like is successfully performed. By devising, the light emission in the surface direction can be made stronger than the edge direction of the light emitting layer. When the surface emitting type is used, the light emission cross-sectional area per unit light emission amount can be increased compared to the type that emits light from the edge of the light emitting layer. As a result, the phosphor of the second light emitter is irradiated with the light Since the irradiation area can be made very large with the same amount of light and the irradiation efficiency can be improved, stronger light emission can be obtained from the phosphor that is the second light emitter.
[0028]
  It is preferable to form the second light emitter in the form of a film because an area for receiving light generated from the first light emitter is increased. In particular, since the cross-sectional area of the light from the surface-emitting type light emitter is sufficiently large, if the second light emitter is formed in a film shape in the direction of the cross section, the irradiation cross-section area of the phosphor from the first light emitter is increased. Since it becomes large per fluorescent substance unit amount, the intensity | strength of light emission from fluorescent substance can be made larger. The positional relationship between the first light emitter and the second light emitter is not particularly limited as long as the light emitted from the first light emitter can be received by the second light emitter. It is preferable that the second light emitter is located at a position where the intensity of light generated from the first light emitter is high.
[0029]
  Furthermore, there may be an air layer, a light transmission layer, a layer for controlling the wavelength of light, a layer for controlling the generated heat, etc. between the first light emitter and the second light emitter. The light emitter and the second light emitter may be in direct contact with each other.
  For example, when a surface-emitting type is used as the first light emitter and a film-like one is used as the second light emitter, the film-shaped second light emitter is directly formed on the light-emitting surface of the first light emitter. It is preferable to have a shape in which is contacted. Contact here refers to creating a state in which the first light emitter and the second light emitter are in perfect contact with each other without air or gas. As a result, it is possible to avoid a light amount loss in which light from the first light emitter is reflected by the film surface of the second light emitter and oozes out, so that the light emission efficiency of the entire apparatus can be improved.
[0030]
  FIG. 2 is a schematic perspective view showing the positional relationship between the first light emitter and the second light emitter in an example of the light emitting device of the present invention. In FIG. 2, 1 denotes a film-like second light emitter having the phosphor, 2 denotes a surface-emitting GaN-based LD as the first light emitter, and 3 denotes a substrate. In order to create a state in which they are in contact with each other, the LD 2 and the second light emitter 1 may be formed separately and the surfaces may be brought into contact with each other by an adhesive or other means, or the light emitting surface of the LD 2 Second light emitter onMadeA film (molded) may be used. As a result, the LD 2 and the second light emitter 1 can be brought into contact with each other.
[0031]
  The light from the first light emitter and the light from the second light emitter are usually directed in all directions, but the second light emitter contains a crystal phase having the chemical composition of the general formula [1]. By making the powdered material, that is, the powdery phosphor, dispersed in the resin, a part of the light is reflected when the light goes out of the resin, so that the direction of the light can be aligned to some extent. This is preferable because light can be guided to an efficient direction to some extent. Further, when the phosphor is dispersed in the resin, the total irradiation area of the light from the first light emitter to the second light emitter is increased, so that the light emission intensity from the second light emitter can be increased. It also has the advantage of being able to The resin that can be used in this case is not particularly limited, and various resins such as an epoxy resin, a polyvinyl resin, a polyethylene resin, a polypropylene resin, and a polyester resin can be used, but the dispersibility of the phosphor powder is good. An epoxy resin is preferable at this point. The phosphor dispersed in the resin is not only a phosphor powder containing a crystal phase having the chemical composition of the general formula [1], but also other phosphors such as red and green phosphor powders. Can be dispersed. When the second phosphor is obtained by dispersing the powdered phosphor in the resin, the weight ratio of all the phosphor powders and the resin to be dispersed in the resin to the powder is usually 10% or more, preferably Is 20% or more, more preferably 30% or more, and the upper limit is 95% or less, preferably 90% or less, and more preferably 80% or less. If the phosphor is too much, the luminous efficiency may be reduced due to aggregation of the powder, and if it is too little, the luminous efficiency may be lowered due to light absorption or scattering by the resin.
[0032]
  The light emitting device of the present invention includes the phosphor as a wavelength conversion material, 350nm ~Light emission that generates 415nm lightbodyAnd the phosphor is emitted by a light emitter.nm ~It is a light-emitting device that absorbs light of 415 nm, has good color rendering properties regardless of the usage environment, and can generate high-intensity visible light. It is a light source such as a backlight light source, a traffic light, and a color liquid crystal. It is suitable for light sources such as image display devices such as displays and lighting devices such as surface emitting devices.
[0033]
  The light-emitting device of the present invention will be described with reference to the drawings. FIG. 3 shows a first light-emitting body (350nm ~415nmGenerating light1 is a schematic cross-sectional view showing an embodiment of a light-emitting device having a light-emitting body and a second light-emitting body. 4 is a light-emitting device, 5 is a mount lead, 6 is an inner lead, and 7 is a first light-emitting body ( 350nm ~415nmGenerate light(Luminous body), 8 is a phosphor-containing resin portion as a second luminous body, 9 is a conductive wire, and 10 is a mold member.
[0034]
  As shown in FIG. 3, the light emitting device as an example of the present invention has a general bullet shape, and a first light emitter made of a GaN-based light emitting diode or the like is disposed in the upper cup of the mount lead 5. (350nm ~415nmGenerating lightThe phosphor is coated with a phosphor-containing resin portion 8 formed as a second phosphor by mixing and dispersing the phosphor in a binder such as an epoxy resin or an acrylic resin and pouring the mixture into the cup. Is fixed. On the other hand, the first light emitter 7 and the inner lead 6 are electrically connected by a conductive wire 9, and the first light emitter 7 and the mount lead 5 are in contact with each other, and the whole is a mold member made of epoxy resin or the like. 10 is covered and protected.
[0035]
  This light emissionapparatusAs shown in FIG. 4, the surface-emitting illumination device 11 incorporating a large number of light-emitting devices 13 is arranged on the bottom surface of a rectangular holding case 12 whose inner surface is light-opaque such as a white smooth surface. Are provided with a power supply and a circuit (not shown) for driving the light emitting device 13, and a milky white diffusing plate 14 such as an acrylic plate is emitted at a position corresponding to the lid portion of the holding case 12. Fixed for homogenization.
[0036]
  Then, the surface emitting illumination device 11 is driven to emit light.apparatus350 by applying a voltage to the 13 first light emitters.nm ~Blue light that emits light of 415 nm, part of the light emission is absorbed by the phosphor in the phosphor-containing resin portion as the second light emitter, emits visible light, and is not absorbed by the phosphor. Light emission with high color rendering properties is obtained by color mixing with light, etc., and this light is transmitted through the diffusion plate 14 and emitted upward in the drawing, and illumination light with uniform brightness is emitted within the surface of the diffusion plate 14 of the holding case 12. Will be obtained.
[0037]
【Example】
  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist.
[0038]
Example 1
  CaHPO_Four; 0.06 mol, CaCO_Three; 0.0255 mol, MgHPO_Four0.06 mol, MgCO_Three0.0255 mol, and Eu₂O_Three0.0045 mol was pulverized and mixed with pure water in an alumina container and a wet ball mill of beads, dried, passed through a nylon mesh, and the resulting pulverized mixture was 4% in an alumina crucible. It is fired by heating at 1100 ° C. for 2 hours under a nitrogen gas stream containing hydrogen, followed by washing with water, drying, and classification treatment to obtain a blue-emitting phosphor Eu._0.15Ca_1.425Mg_1.425(PO_Four)₂Manufactured. FIG. 5 shows the X-ray diffraction pattern of this phosphor. The peak pattern of FIG. 5 is the Ca of FIG._ThreeMg_Three(PO_Four)_FourIt can be seen that the crystal structure almost coincides with that of. FIG. 6 shows an emission spectrum when the phosphor is excited at 400 nm, which is the dominant wavelength in the ultraviolet region of a GaN-based light emitting diode. Table 1 shows the wavelength of the emission peak, the relative integrated intensity, and the half width.
[0039]
Example 2
  The raw material used is CaHPO_Four; 0.06 mol, CaCO_Three0.0282 mol, MgHPO_Four0.06 mol, MgCO_Three0.0282 mol, and Eu₂O_Three; Phosphor Eu in the same manner as in Example 1 except that the amount was changed to 0.0018 mol._0.06Ca_1.47Mg_1.47(PO_Four)₂Manufactured. FIG. 7 shows the X-ray diffraction pattern of this phosphor. The peak pattern of FIG. 7 is the Ca of FIG._ThreeMg_Three(PO_Four)_FourIt can be seen that the crystal structure almost coincides with that of. The phosphor was excited at 400 nm, which is the dominant wavelength in the ultraviolet region of a GaN-based light emitting diode, and the emission spectrum was measured. Table 1 shows the wavelength of the emission peak, the relative integrated intensity, and the half width.
[0040]
Example 3
  The raw material used is CaHPO_Four; 0.06 mol, CaCO_Three0.0291 mol, MgHPO_Four0.06 mol, MgCO_Three0.0291 mol, and Eu₂O_Three; Phosphor Eu in the same manner as in Example 1 except that the amount was changed to 0.0009 mol._0.03Ca_1.485Mg_1.485(PO_Four)₂Manufactured. The phosphor was excited at 400 nm, which is the dominant wavelength in the ultraviolet region of a GaN-based light emitting diode, and the emission spectrum was measured. Table 1 shows the wavelength of the emission peak, the relative integrated intensity, and the half width.
[0041]
Example 4
  The raw material used is CaHPO_Four; 0.06 mol, CaCO_Three0.02955 mol, MgHPO_Four0.06 mol, MgCO_Three0.02955 mol, and Eu₂O_Three; Phosphor Eu in the same manner as in Example 1 except that 0.00045 mol was changed._0.015Ca_1.4925Mg_1.4925(PO_Four)₂Manufactured. FIG. 8 shows the X-ray diffraction pattern of this phosphor. The peak pattern of FIG. 8 is the Ca of FIG._ThreeMg_Three(PO_Four)_FourIt can be seen that the crystal structure almost coincides with that of. The phosphor was excited at 400 nm, which is the dominant wavelength in the ultraviolet region of a GaN-based light emitting diode, and the emission spectrum was measured. Table 1 shows the wavelength of the emission peak, the relative integrated intensity, and the half width.
[0042]
Example 5
  The raw material used is CaHPO_Four; 0.06 mol, CaCO_Three0.02991 mol, MgHPO_Four0.06 mol, MgCO_Three0.02991 mol, and Eu₂O_Three; Phosphor Eu in the same manner as in Example 1 except that the amount was changed to 0.00009 mol._0.003Ca_1.4985Mg_1.4985(PO_Four)₂Manufactured. The phosphor was excited at 400 nm, which is the dominant wavelength in the ultraviolet region of a GaN-based light emitting diode, and the emission spectrum was measured. Table 1 shows the wavelength of the emission peak, the relative integrated intensity, and the half width.
[0043]
Example 6
  The raw material used is CaHPO_Four0.0802 mol, CaCO_Three0.0389 mol, MgHPO_Four0.0398 mol, MgCO_Three0.0193 mol, and Eu₂O_Three; Phosphor Eu in the same manner as in Example 1 except that the amount was changed to 0.0009 mol._0.03Ca_1.985Mg_0.985(PO_Four)₂Manufactured. The phosphor was excited at 400 nm, which is the dominant wavelength in the ultraviolet region of a GaN-based light emitting diode, and the emission spectrum was measured. Table 1 shows the wavelength of the emission peak, the relative integrated intensity, and the half width.
[0044]
Example 7
  The raw material used is CaHPO_Four; 0.12 mol, CaCO_Three0.0582 moles, and Eu₂O_Three; Phosphor Eu in the same manner as in Example 1 except that the amount was changed to 0.0009 mol._0.03Ca_2.97(PO_Four)₂Manufactured. The phosphor was excited at 400 nm, which is the dominant wavelength in the ultraviolet region of a GaN-based light emitting diode, and the emission spectrum was measured. Table 1 shows the wavelength of the emission peak, the relative integrated intensity, and the half width.
[0045]
Example 8
  The raw material used is CaHPO_Four0.0398 mol, CaCO_Three0.0193 mol, MgHPO_Four0.0802 mol, MgCO_Three0.0389 mol, and Eu₂O_Three; Phosphor Eu in the same manner as in Example 1 except that the amount was changed to 0.0009 mol._0.03Ca_0.985Mg_1.985(PO_Four)₂Manufactured. The phosphor was excited at 400 nm, which is the dominant wavelength in the ultraviolet region of a GaN-based light emitting diode, and the emission spectrum was measured. Table 1 shows the wavelength of the emission peak, the relative integrated intensity, and the half width.
[0046]
Comparative Example 1
  The raw material used is MgHPO_Four0.12 mol, MgCO3; 0.0594 mol, and Eu₂O_Three; Phosphor Eu in the same manner as in Example 1 except that the amount was changed to 0.0003 mol._0.01Mg_2.99(PO_Four)₂Manufactured. The phosphor was excited at 400 nm, which is the dominant wavelength in the ultraviolet region of a GaN-based light emitting diode, and the emission spectrum was measured. Table 1 shows the wavelength of the emission peak, the relative integrated intensity, and the half width. A phosphor having a composition that does not contain Ca has a lower emission intensity and a smaller half-value width of the emission peak than a phosphor having a composition that contains Ca.
[0047]
[Table 1]

[0048]
【The invention's effect】
  According to the present invention, it is possible to provide a light emitting device having high color rendering properties and high emission intensity.
[Brief description of the drawings]
[Figure 1] Ca_ThreeMg_Three(PO_Four)_FourX-ray diffraction pattern (converted to X-ray source Cu Kα).
FIG. 2 is a diagram showing an example of a light-emitting device in which a surface-emitting GaN-based diode is contacted or molded with a film-like second light emitter.
FIG. 3 shows a first light emitter (350 in the present invention).nm ~415nmGenerating lightIt is typical sectional drawing which shows one Example of the light-emitting device comprised from a light-emitting body and a 2nd light-emitting body.
FIG. 4 is a schematic cross-sectional view showing an example of a lighting device of the present invention.
5 is an X-ray diffraction pattern (X-ray source: Cu Kα) of the phosphor of Example 1. FIG.
FIG. 6 is a spectrum obtained by superposing the emission spectra of the phosphors of Example 1 and Comparative Example 1 irradiated with a GaN-based light emitting diode having an emission wavelength of 400 nm.
7 is an X-ray diffraction pattern (X-ray source: Cu Kα) of the phosphor of Example 2. FIG.
8 is an X-ray diffraction pattern (X-ray source: Cu Kα) of the phosphor of Example 4. FIG.
[Explanation of symbols]
1: Second light emitter
2: Surface-emitting GaN LED
3; Substrate
4: Light emitting device
5: Mount lead
6; Inner lead
7; first luminous body (350nm~ 415nmGenerate lightLuminous body)
8; FluorescenceBody-containing treeFat part
9; Conductive wire
10: Mold member
11: Surface emitting illumination device incorporating a light emitting device
12; Holding case
13: Light emitting device
14: Diffuser

Claims (13)

In the light emitting device including the first light emitter that generates light of 400 nm to 415 nm and the second light emitter that generates visible light by irradiation of light from the first light emitter, the second light emission A light emitting device characterized in that the body contains a phosphor having a crystal phase having a chemical composition of the general formula [1].
Eu _a M _b (PO ₄ ) _c (BO ₃ ) _2-c Z _d ... [1]
(In the above general formula [1], M represents a metal element containing Ca and at least one element selected from the group consisting of Ca and Mg occupying 80 mol% or more, and Z represents PO ₄ ^3- Represents an anion other than BO ₃ ^3- , a is 0.15 ≦ a ≦ 2.1, b is 2.7 ≦ (a + b) ≦ 3.3, c is 1.2 ≦ c ≦ 2, d is a number satisfying 0 ≦ d ≦ 0.1.) The light emitting device according to claim 1, wherein the first light emitter is a laser diode or a light emitting diode. The light emitting device according to claim 1 or 2, the first light emitter is a laser diode. The light emitting device according to any one of claims 1 to 3 , wherein, in the element M, a ratio of Ca to a total of Ca and Mg is 40 mol% or more. c is the light-emitting device according to any one of claims 1 to 4, characterized in that a 1.6 ≦ c ≦ 2. The light emitting device according to any one of claims 1 to 5 , wherein the element M is made of at least one element selected from the group consisting of Ca and Mg, and contains 40 mol% or more of Ca. Formula _{[1], Eu a M b (PO 4} ) light-emitting device according to any one of claims 1 to 6, characterized in that a ₂ Z _d. First light emitter emitting device according to any one claims 1, wherein 7 to be a GaN-based compound semiconductor. First light emitter emitting device according to any one of claims 1 to 8, characterized in that a surface-emitting type GaN-based laser diode. The light emitting device according to any one of claims 1 to 9 second light emitter is characterized in that it is a film. The light emitting device according to claim 10 , wherein a film containing the second light emitter is directly brought into contact with a light emitting surface of the first light emitter that generates light of 400 nm to 415 nm. The second luminous body, a powder containing a phosphor having a crystal phase having a chemical composition represented by the general formula [1], claims 1, characterized in that it is obtained by dispersing the resin 11 The light emitting device according to any one of the above. Lighting device having any one of the light emitting device of claims 1 to 12.

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