JP4219621B2 - Manufacturing method of white light emitting diode - Google Patents

Description

【発明の効果】
１．図３から分かるように、本発明の方法（実施の形態参照）と従来の方法とがすべて色度座標が標準白色光区域に位置する効果を取得でき、例えば従来の方法の（０．３１３０，０．３２４５）と実施の形態の（０．３１２０，０．３２８５）のようである。そのため、本発明の白色光ダイオードと従来の方法と同様に白色光発光ダイオードを提供できる。
【００２８】
２．表に示すように、従来の方法の場合では、三種類の蛍光粉によって赤、緑、青の三原色より組成される白色光を取得し、その演色性が単に８５であり、且つ色彩温度が６５２４Ｋ（絶対温度）である。本発明の実施の形態の場合ではＹ_３Ａｌ_５Ｏ_１２：Ｃｅ，Ｇｄ型黄色蛍光粉によってスペクトル構成を修飾し、それで演色性を９４に、色彩温度を６５５０Ｋになるように向上できる。その主要な原因はスペクトル構成修飾後の白色光スペクトルと真実の太陽光のスペクトルとの分布が近くなるためであり、それによって高演色性を取得し、そのため、本発明の白色光発光ダイオードの場合では演色性が従来の方法よりかなり優れている。
【００２９】
３．本発明の白色光発光ダイオードの場合では、その発光スペクトルが修飾されると、例えば実施の形態におけるＹ_３Ａｌ_５Ｏ_１２：Ｃｅ，Ｇｄ型蛍光粉の黄色光またはＢａＭｇＡｌ１０Ｏ１７：Ｅｕ，Ｍｎ型蛍光粉の青緑色光（蛍光粉においてＥｕ／Ｍｎの比例と発光する青色／緑色の波長の相対的強度と関係があり、そのため、それらも自身の色彩を修飾することと調整制御することの機能を有する）などがすべて緑色光の波長に近くなり、即ち、人間の眼部に対し敏感性を有する区域になり、それらは全体の白色光の強度の向上に作用を有し、そのため、本発明の白色光発光ダイオードの発光効率が従来の方法より優れている。
【００３０】
４．本発明の白色光発光ダイオードの場合では、図４に示すように、混合蛍光粉体における（Ｓｒ_０．９４Ｅｕ_０．０４Ｄｙ_０．０２）Ａｌ_２Ｏ_４が緑色の燐光特性を有するので、励起光源を取り除くと、粉末体の光色が白色よりだんだん緑色に変化すると共に、所定の時間を維持できる。同じように、二種類以上の燐光特性を有する粉末体を使用すれば、その生成する光色の変換が多彩多様になる。そのため、本発明の方法に従って所定の比例になるように複数種の粉末体を混合する場合、且つ所定の波長（この例では３９６ｎｍである）の紫外線発光ダイオードを励起光源として合わせて使用する場合、且つ適当にパッケージングすると、所定の電流を流す場合、混合される粉末体同士が紫外線の照射を受けてから励起を停止すると、随時に光色を変換できる発光ダイオードを入手できる。
【００３１】
本発明の前記に述べる実施の形態は単に本発明の具体的な実施例に過ぎず、本発明の要旨はそれらのみに狭義的に制限されず、いずれの同時に三種類の主波長が５８５ｎｍ−６４０ｎｍである赤色光と５００ｎｍ−５７０ｎｍである緑色光と４３０ｎｍ−４９０ｎｍである青色光などの三原色を発光できる蛍光体に他の一種以上の蛍光粉を合わせて白色光スペクトルの補強及び修飾する機能を発揮できる手段によって高明るさと高演色性を取得できる優れる白色光発光ダイオードを取得することを目的として実施される変化や修飾などがすべて本発明の特許主張範囲内に納入されるべきである。本発明も変色可能な発光ダイオードの製造方法に係わり、燐光特性を有する発光体を前記複数種の蛍光体のうちの１つまたはそれ以上の成分とすることによってその光色に時間の経過に従って異なる色彩の変化を生じさせることができる。
【図面の簡単な説明】
【図１】従来のＹ_２Ｏ_３：Ｅｕ，ＳｒＡｌ_２Ｏ_４：Ｅｕ，ＢａＭｇＡｌ_１０Ｏ_１７：Ｅｕなどの三種類の蛍光粉同士によってそれぞれ赤、緑、青の色の蛍光を発光させる場合の白色光スペクトルを示す説明図である。
【図２】本発明のＹ_２Ｏ_３：Ｅｕ，ＳｒＡｌ_２Ｏ_４：Ｅｕ，ＢａＭｇＡｌ_１０Ｏ_１７：Ｅｕなどの三種類の蛍光粉同士によってそれぞれ赤、緑、青の色の蛍光を発光させると共に、Ｙ_３Ａｌ_５Ｏ_１２：Ｃｅ，Ｇｄ蛍光体の発光する黄色蛍光を合わせることによって発光する白色光のスペクトルを示す説明図である。
【図３】図１と図２の発射するベクトルに基づいてそれぞれ計算し得た混合蛍光粉の色度座標ＡとＢを示す説明図である。
【図４】本発明の同時にＹ_２Ｏ_３：Ｅｕ，ＳｒＡｌ_２Ｏ_４：Ｅｕ、Ｄｙ，ＢａＭｇＡｌ_１０Ｏ_１７：Ｅｕ、Ｙ_３Ａｌ_５Ｏ_１２：Ｃｅ，Ｇｄ蛍光体を混合して発光される白色光を始発点とし、且つ紫外線励起光源を取り除く場合の光色が時間の経過に従って変化する状況を示す変化図である。
【符号の説明】[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a white light emitting diode, and more particularly to a method for producing and obtaining a white light emitting diode by blending a plurality of types of fluorescent powders.
[0002]
[Prior art]
White light is a mixed combined light of a plurality of facial colors, and a light beam identified as white light by the human eye includes a mixed light beam having at least two types of wavelengths. For example, if the human eye is simultaneously stimulated by red, blue, and green rays, or if it is simultaneously stimulated by blue and yellow rays, it will be perceived as white light. An LED light source that emits white light can be manufactured. There are five types of conventional white light LED manufacturing methods. The first type of method uses three LEDs made of AlInGaP, GaP, and GaN, and controls the current passing through each LED. , Emit light of green and blue colors. Since these three crystal granules are disposed in the same lamp, white light can be emitted by mixing the light beams emitted through the range. The second type uses two LEDs made of GaN and AlInGaP, and generates white light by emitting blue and yellow-green light by controlling the current passing through these LEDs. To do. At present, these two methods can reach a luminous efficiency of 20 lm / W. The third type is a white light source that was developed by Nichia Chemical Company in Japan in 1996 by combining an indium gallium nitride blue light emitting diode with a yttrium aluminum garnet fluorescent powder that emits yellow light. It is a method of manufacturing. The luminous efficiency of this method is slightly lower than the above-mentioned methods in the present case (which can reach 15 lm / W or more), but it does not require a single set of chips, so the manufacturing cost can be greatly reduced, Since the preparation technology of the fluorescent powder used together is already perfect, products have already been submitted. A fourth type of white light can be generated by a white light LED using ZnSe material, which was developed in January 1999 by two Sumitomo Electric Industries, Ltd. A CdZnSe thin film is formed on a chip substrate, and the thin film emits blue light after energization. A part of the blue light irradiates the substrate to emit yellow light. Finally, the blue light and yellow light are mutually transmitted. It complements and emits white light. Even in this method, since only one LED crystal granule is employed, the operating voltage is simply 2.7 V, which is lower than 3.5 V of InGaN LED, and white light can be obtained even without a fluorescent material. . It is an ultraviolet white light LED that is currently under development as a method for generating the fifth type of white light, that is, a method in the field of the present invention, and its principle is to excite three types of fluorescent powder by the ultraviolet LED. Thus, fluorescence is generated and white light is generated by color mixture. Conventional methods in the field are as follows.
[0003]
1. A fluorescent powder having a composition of Y ₂ O ₃ : Eu, such as (Y _1.9 Eu _0.1 ) O _3, is synthesized, and as the synthesis method, a solid reaction method or a chemical synthesis method such as a citrate gel method or a common method is used. A precipitation method or a microcolloid method can be employed.
[0004]
2. SrAl ₂ O ₄ : Eu type fluorescent powder such as (Sr _0.96 Eu _0.04 ) Al ₂ O ₄ is synthesized and obtained as a synthesis method, such as a solid reaction method or a chemical synthesis method such as a citrate gel method. Or a coprecipitation method or a microcolloid method can be employed.
[0005]
3. BaMgAl ₁₀ O ₁₇ : Eu type fluorescent powder such as (Ba _0.9 Eu _0.1 ) MgAl ₁₀ O ₁₇ is synthesized and obtained as a synthesis method, such as a solid reaction method or a chemical synthesis method such as a citrate gel method. Or a coprecipitation method or a microcolloid method can be employed.
[0006]
4). The three types of fluorescent powders are prepared in a predetermined proportion and the emission spectrum is detected using ultraviolet light having a wavelength of 396 nm as an excitation source, as shown in FIG. The emission spectrum data is converted into a chromaticity coordinate representative of the phosphor by a formula of a chromaticity coordinate diagram established by the International Commission on Illumination (Commission Internationale de 1 'Eclairage, CIE) in 1931. And it is marked in FIG.
[0007]
As can be seen from the above description, the method of manufacturing a white light LED by using an ultraviolet light emitting diode is to excite phosphors of the three primary colors of red, green and blue mainly by ultraviolet rays, and to prepare the phosphors in an appropriate proportion. Then, white light is obtained by mixing the colored light.
[0008]
However, in the case of white light generated by combining the spectrum configurations of the respective primary color phosphors, since the individual fluorescent powder is affected by having a predetermined spectrum configuration, the white light composed thereof Since the distribution and continuity of the wavelength of this spectrum do not reach true sunlight, it has disadvantages such as non-uniform color for white light and low saturation. The human eye can abbreviate these phenomena and only white light can be seen, but when it is detected by an optical detector with high precision, for example, by video or camera, its color rendering is still low. Considered, i.e., errors may occur when reducing the color of an object, so that a white light source produced by this type of scheme is only suitable for general lighting applications.
[0009]
[Problems to be solved by the invention]
The main object of the present invention is to propose a method for manufacturing a new white light emitting diode, and the feature of the method is to use phosphors that can be excited by a plurality of types of ultraviolet rays, and some of the phosphors. Forms the basic structure of the spectrum of three types of white light such as red, green, blue, etc., and provides the color light for modification by other parts of the phosphor, improves its brightness, and the color mixture spectrum of the phosphors And the degree of similarity between the actual solar spectrum is greatly improved. Therefore, the present invention has an excellent point that white light-emitting diodes obtained by a technique for reinforcing and modifying a plurality of types of fluorescent powders can have high brightness and high color rendering properties.
[0010]
[Means for Solving the Problems]
Another object of the present invention is to provide a method of manufacturing a light emitting diode capable of changing color. At present, as a method for obtaining a light-emitting diode capable of changing the light color, a plurality of single-color light-emitting diodes are combined with each other, the light emission order is controlled by an electric circuit, or a light-filtering piece or a hat cover having a different facial color. The light color is converted by. However, in the case of such a method, the manufacturing cost is high and it is not convenient, so it is necessary to develop a new feasible method. For example, a technique for reinforcing and modifying a plurality of kinds of fluorescent powders as described above is adopted, and all or some of the powder bodies have fluorescent or phosphorescent properties at the same time. The body obtains the effect of changing its light color over time, i.e., according to the method of the present invention, a light-emitting diode capable of changing color can be produced. Moreover, the light emitting diode which has a different color change order can be provided by changing the composition proportion of the powder pairs. Compared with the prior art, the method of the present invention is considerably simpler, lower in cost, and rich in industrial utility value.
[0011]
The features and technical contents of the present invention will be described in detail below with reference to the accompanying drawings, but these descriptions are merely a part of preferred embodiments of the present invention, and the scope of the present invention is narrowly defined. It is not defined.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is a method related to a method of manufacturing a white light emitting diode using a powder body agreement having a plurality of types of fluorescence characteristics, which is applied to a light emitting diode. In this method, a light emitting diode capable of emitting ultraviolet light, an electron beam, plasma, or the like is used as an excitation light source, and three types of fluorescent powders are excited with each other to emit red light having a wavelength of 585 nm to 640 nm, green light having a wavelength of 500 nm to 570 nm, and 430 nm. Emits blue light of -490 nm. At the same time, in view of the fluorescence characteristics of these three wavelengths, such as emission intensity and color saturation, reinforcement or modification is performed by the fluorescence characteristics of one or more other fluorescent powders, and these four or more wavelengths are changed. The white light is generated after mixing the fluorescence provided. The white light obtained by the fluorescent reinforcement and modification technique of the present invention has an excellent point of high brightness and high color rendering than the conventional method of simply using phosphors of the three primary colors of red, green and blue.
[0013]
As one embodiment of the required fluorescent powder for synthesis and preparation of the white light emitting diode of the present invention (in one of the methods of the present invention, a method of showing the spectrum of white light obtained after modifying the spectrum structure) ) The following methods are mentioned.
[0014]
1. A fluorescent powder having a composition of Y ₂ O ₃ : Eu, such as (Y _1.9 Eu _0.1 ) O _3, is synthesized, and as the synthesis method, a solid reaction method or a chemical synthesis method such as a citrate gel method or a common method is used. A precipitation method or a microcolloid method can be employed.
[0015]
2. SrAl ₂ O ₄ : Eu type fluorescent powder such as (Sr _0.96 Eu _0.04 ) Al ₂ O ₄ is synthesized and obtained as a synthesis method, such as a solid reaction method or a chemical synthesis method such as a citrate gel method. Or a coprecipitation method or a microcolloid method can be employed.
[0016]
3. BaMgAl ₁₀ O ₁₇ : Eu type fluorescent powder such as (Ba _0.9 Eu _0.1 ) MgAl ₁₀ O ₁₇ is synthesized and obtained as a synthesis method, such as a solid reaction method or a chemical synthesis method such as a citrate gel method. Or a coprecipitation method or a microcolloid method can be employed.
[0017]
4). The composition is Y ₃ Al ₅ O ₁₂ : Ce, Gd type fluorescent powder, for example, (Y _2.3 Ce _{0 .05} Gd _0.65 ) Al ₅ O ₁₂ is obtained and synthesized as a solid reaction method or chemical synthesis. For example, a citrate gel method, a coprecipitation method, or a microcolloid method can be employed.
[0018]
5. The four types of fluorescent powders are prepared in a predetermined proportion and the emission spectrum is detected using ultraviolet light having a wavelength of 396 nm as an excitation source, as shown in FIG. The data of the emission spectrum is converted into chromaticity coordinates representing this mixed phosphor and is shown in FIG.
[0019]
The present invention also relates to a method of manufacturing a kind of light-emitting diode capable of changing color, and a phosphor having phosphorescence characteristics is one or a plurality of phosphors of the plurality of phosphors, and the light colors are different from each other over time. Changes can be exhibited. SrAl ₂ O ₄ : Eu, M, CaAl ₂ O ₄ : Eu, M, Sr ₄ Al ₁₄ O ₂₅ : Eu, M, Y ₂ O ₂ S: Eu, M, ZnS: Cu, M, etc. Among them, transition metal, rare earth element, etc. can be adopted as M.
[0020]
Regarding one of the manufacturing examples of a discolorable light emitting diode manufactured by a powder having phosphorescent properties, the manufacturing steps are as follows.
[0021]
1. A fluorescent powder having a composition of Y ₂ O ₃ : Eu, such as (Y _1.9 Eu _0.1 ) O _3, is synthesized, and as the synthesis method, a solid reaction method or a chemical synthesis method such as a citrate gel method or a common method is used. A precipitation method or a microcolloid method can be employed.
[0022]
2. The composition is SrAl ₂ O ₄ : Eu, Dy type fluorescent powder, for example, (Sr _0.94 Eu _0.04 Dy _0.02 ) Al ₂ O ₄ is synthesized and acquired, and as its synthesis method, solid reaction method or chemical synthesis method, For example, a citrate gel method, a coprecipitation method, a microcolloid method, or the like can be employed.
[0023]
3. BaMgAl ₁₀ O ₁₇ : Eu type fluorescent powder such as (Ba _0.9 Eu _0.1 ) MgAl ₁₀ O ₁₇ is synthesized and obtained as a synthesis method, such as a solid reaction method or a chemical synthesis method such as a citrate gel method. Or a coprecipitation method or a microcolloid method can be employed.
[0024]
4). The composition is Y ₃ Al ₅ O ₁₂ : Ce, Gd type fluorescent powder, for example, (Y _2.3 Ce _0.05 Gd _0.65 ) Al ₅ O ₁₂ is synthesized and acquired, and as its synthesis method, solid reaction method or chemical synthesis For example, a citrate gel method, a coprecipitation method, or a microcolloid method can be employed.
[0025]
5. The four types of fluorescent powders are prepared in a predetermined proportion, and the emission spectrum is detected using ultraviolet light having a wavelength of 396 nm as an excitation source. In addition, the UV excitation light source is removed, the emission spectrum is detected several times at predetermined time intervals, the data of these emission spectra are converted into the chromaticity coordinates of each time point, and more and more from point A The points go to and are marked in FIG.
[0026]
As shown in the table below, when comparing the white light spectrum of the embodiment of the present invention with the conventional method obtained by calculation, it can be seen that the color rendering properties and the color temperature of the present invention are much more preferable than the conventional one.
[0027]

【The invention's effect】
1. As can be seen from FIG. 3, the method of the present invention (see the embodiment) and the conventional method can all obtain the effect that the chromaticity coordinates are located in the standard white light area, for example, (0.3130, 0.3245) and (0.3120, 0.3285) of the embodiment. Therefore, a white light emitting diode can be provided in the same manner as the white light diode of the present invention and the conventional method.
[0028]
2. As shown in the table, in the case of the conventional method, white light composed of three primary colors of red, green, and blue is obtained by three kinds of fluorescent powders, the color rendering property is simply 85, and the color temperature is 6524K. (Absolute temperature). In the case of the embodiment of the present invention, the spectrum configuration is modified with Y ₃ Al ₅ O ₁₂ : Ce, Gd type yellow fluorescent powder, so that the color rendering property can be improved to 94 and the color temperature can be improved to 6550K. The main reason is that the distribution of the white light spectrum after modification of the spectral structure and the distribution of the true sunlight spectrum are close, thereby obtaining high color rendering properties. Therefore, in the case of the white light emitting diode of the present invention, Then, the color rendering is much better than the conventional method.
[0029]
3. In the case of the white light emitting diode of the present invention, when the emission spectrum is modified, for example, the yellow light of the Y ₃ Al ₅ O ₁₂ : Ce, Gd type fluorescent powder or the BaMgAl ₁₀ O 17: Eu, Mn type fluorescent powder in the embodiment Of blue / green light (there is a relationship between the ratio of Eu / Mn in fluorescent powder and the relative intensity of the emitted blue / green wavelength, so they also have the functions of modifying and controlling their own color) ) Etc. are all close to the wavelength of green light, that is, areas that are sensitive to the human eye, which have an effect on increasing the intensity of the overall white light, so that the white of the present invention The light emitting efficiency of the light emitting diode is superior to the conventional method.
[0030]
4). In the case of the white light emitting diode of the present invention, as shown in FIG. 4, (Sr _0.94 Eu _0.04 Dy _0.02 ) Al ₂ O ₄ in the mixed fluorescent powder has a green phosphorescence characteristic. When the excitation light source is removed, the light color of the powder body gradually changes from white to green, and a predetermined time can be maintained. Similarly, if a powder body having two or more types of phosphorescence characteristics is used, the conversion of the light color generated becomes diverse. Therefore, when mixing a plurality of types of powder bodies so as to have a predetermined proportion according to the method of the present invention, and when using an ultraviolet light emitting diode of a predetermined wavelength (in this example, 396 nm) as an excitation light source, And when appropriately packaged, when a predetermined current is passed, a light emitting diode capable of converting the light color at any time can be obtained if excitation is stopped after the powder bodies to be mixed are irradiated with ultraviolet rays.
[0031]
The above-described embodiments of the present invention are merely specific examples of the present invention, and the gist of the present invention is not limited to them in a narrow sense, and any of the three main wavelengths is 585 nm to 640 nm at the same time. A phosphor capable of emitting three primary colors, such as red light, 500 nm-570 nm green light, and 430 nm-490 nm blue light, are combined with one or more other fluorescent powders to enhance and modify the white light spectrum. All changes and modifications carried out for the purpose of obtaining an excellent white light emitting diode capable of obtaining high brightness and high color rendering by means capable of being delivered should be delivered within the scope of the patent claim of the present invention. The present invention also relates to a method of manufacturing a light-emitting diode capable of changing color, and a phosphor having phosphorescent characteristics is used as one or more components of the plurality of types of phosphors, so that the light color varies with time. A color change can be produced.
[Brief description of the drawings]
FIG. 1 shows a case where red, green, and blue fluorescent lights are emitted by three kinds of fluorescent powders such as Y ₂ O ₃ : Eu, SrAl ₂ O ₄ : Eu, BaMgAl ₁₀ O ₁₇ : Eu, respectively. It is explanatory drawing which shows a white light spectrum.
FIG. 2 shows fluorescence of red, green, and blue colors emitted by three kinds of fluorescent powders such as Y ₂ O ₃ : Eu, SrAl ₂ O ₄ : Eu, BaMgAl ₁₀ O ₁₇ : Eu of the present invention. , Y ₃ Al ₅ O ₁₂ : Ce, Gd is an explanatory diagram showing the spectrum of white light emitted by combining the yellow fluorescence emitted from the phosphor.
FIG. 3 is an explanatory diagram showing chromaticity coordinates A and B of mixed fluorescent powder that can be calculated based on the vectors to be emitted in FIGS. 1 and 2, respectively.
FIG. 4 is a mixture of Y ₂ O ₃ : Eu, SrAl ₂ O ₄ : Eu, Dy, BaMgAl ₁₀ O ₁₇ : Eu, and Y ₃ Al ₅ O ₁₂ : Ce, Gd phosphors simultaneously emitted from the present invention. It is a change figure which shows the condition where the light color at the time of removing white_light | sunlight as a starting point and removing an ultraviolet-ray excitation light source changes with progress of time.
[Explanation of symbols]

Claims (3)

  Providing ultraviolet light as excitation light;
  Providing three types of phosphors that are excited by the ultraviolet rays and generate red light, green light and blue light, respectively;
  Modify the spectral characteristics of the red light, green light and blue light generated by the three types of phosphors, and improve the luminance and color rendering of white light by the red light, green light and blue light Providing a fluorescent powder;
  Including
  The method of manufacturing a white light emitting diode, wherein the three kinds of phosphors and fluorescent powders have phosphorescent characteristics that emit light of different colors with time after being excited.   2. The method of manufacturing a white light emitting diode according to claim 1, wherein the three kinds of phosphors and fluorescent powders having the phosphorescence characteristics are excited by the ultraviolet light or the visible light.   The three types of phosphors and phosphor powders having the phosphorescent properties are SrAl ₂ O ₄ : Eu, M and CaAl ₂ O ₄ : Eu, M and Sr ₄ Al ₁₄ O ₂₅ : Eu, M and Y ₂ O ₂ 2. The method of manufacturing a white light emitting diode according to claim 1, comprising: S: Eu, M and ZnS: Cu, M, wherein M is a transition metal or a rare earth element.

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