TW572994B - Method for manufacturing white light source - Google Patents

Abstract

It is the object of the present invention to provide a method for manufacturing high-brightness white light source by ultra-violet light source and suitable phosphor. The emission spectrums of the phosphors after being excited by the ultra-violet radiation source should cover the wavelength regimes of red light (585-640 nm), green light (500-570 nm) and blue light (430-490 nm). In one aspect of the present invention, the method for manufacturing white light source includes the steps of providing an ultra-violet light as radiation source; and preparing two kinds of phosphors each receiving the ultra-violet light and emitting light of different wavelength. In another aspect of the present invention, one phosphor is designated to emit light covering two wavelength regimes of three primitive colors, and another phosphor is designated to emit light covering remaining wavelength regime of the three primitive colors. The phosphors are mixed in predetermined ratio such that the lights of different wavelength are combined to provide a white light.

Description

572994 __Case No. 90123332_Year Month and Day Amendment __ V. Description of the invention (1) [Technical field to which the invention belongs] The present invention is a method for preparing a white light source, especially a UV light source that can be used with a fluorescent lamp. Materials with optical properties to make high-brightness white light emitting elements. [Prior art] White light is a multi-color mixed light, which can be perceived by the human eye as white light, and includes at least two wavelengths of mixed light. For example, when the human eye is stimulated by red, blue, and green light at the same time, or when it is stimulated by blue and yellow light at the same time, it can be perceived as white light. Therefore, a white light-emitting LED light source can be produced according to this principle. There are five conventional white LED manufacturing methods: The first method is to use three LEDs made of aluminum gallium indium phosphide (InGaAIP), gallium nitride (GaN), and gallium phosphide (GaP). The LED current emits red, green and blue light. Because these three crystal grains are placed in the same bulb (1 amp), the lens can mix the emitted light to produce white light. The second method uses two LEDs made of GaN and GaP. It also controls the emission of blue and yellow-green light through the LED current to generate white light. The luminous efficiency of the two methods mentioned above can reach 20 lm / W. The third is the 1996 development of Nichia Chemical's Ji Ming garnet-type fluorescent powder with indium gallium nitride blue light-emitting diodes and yellow light, which can also become a white light source. The luminous efficiency of this method can reach 15 lm / W. Although it is slightly lower than the previous two methods, only a set of LED chips can be used to greatly reduce the manufacturing cost. In addition, the matching phosphor modulation technology has become mature. So there are already products present. The fourth solution that can produce white light was developed by Japan's Sumitomo Electric (gUmit〇m〇 Electric Indus tries, Ltd.)

572994 — Case No. 90123332 #: _A. Β Amendment V. Description of the invention (2) White LED of zinc (ZnSe) material, its technology is to first form a CdZnSe thin film on a ZnSe single crystal substrate. The blue light irradiates the substrate to emit yellow light, and finally the blue and yellow light form complementary colors to emit white light. Since this method uses a single LED die, its operating voltage is only 2. 7 V, which is lower than the 3.5 V of GaN LEDs, and no fluorescent substance is required to obtain white light. The fifth solution that can generate white light is the ultraviolet white LED that is currently under development. The principle is to use ultraviolet LEDs to excite a variety of fluorescent powders to emit fluorescent light and generate white light after color mixing. The first and second solutions that can generate white light have the common disadvantage that if one of these simultaneously used LEDs of different light colors fails, normal white light cannot be obtained; and because their forward biases are different Therefore, multiple sets of control circuits are needed, resulting in higher costs, which are all unfavorable factors in practical applications. The third solution that can generate white light is to use the principle of complementary colors to generate white light. The continuity of its spectral wavelength distribution is not as good as that of real sunlight. After mixing the colored light, it will appear in the visible light spectral range (40 0 nm ~ 70 0 nm). The uneven color results in low color saturation; although human eyes can ignore these phenomena and only see white light, it is sensed by some high-precision optical detectors, such as cameras or cameras In fact, its color rendering is still low, that is, when the color of an object is reduced, an error occurs. Therefore, the white light source generated in this way is only suitable for simple lighting purposes. The fourth solution that can generate white light has the disadvantages that the luminous efficiency is only 8 lm / w and the life is only 8000 hours. It must be further broken down in practical considerations.

Page 9 572994 Case No. 90123332 V. Description of the invention (3) The fifth scheme to generate white light, because the conventional three-wavelength type white light source is used in order to improve its color rendering. Generally, three or more phosphors are used. However, when using a variety of fluorescent powders to make them emit fluorescence, one of the prerequisites is that the selected excitation light can be absorbed by these fluorescent powders, and the absorption coefficient of each phosphor for this wavelength of light is not & There are too many differences, and the quantum efficiency of light energy conversion is preferably as close as possible. Therefore, the types of fluorescent materials that are applicable are greatly restricted, which makes it difficult to select fluorescent materials. [Summary of the invention] The reason is that the inventor has devoted his research and cooperated with the application of science to consider the above factors in order to obtain a considerable luminous efficiency without reducing the type of powder. A method for producing a white light source by reducing and relaxing the limitation of the excitation light wavelength on selection. It is an object of the present invention to provide a method for preparing a high-brightness white light source, which uses ultraviolet light as an excitation light source and cooperates with two kinds of fluorescent materials. The two kinds of fluorescent materials can be excited by ultraviolet light of a selected wavelength. It emits red light with main wavelengths between 585 nm and 640 nm, green light between 500 nm and 570 nm, and blue light between 4300 nm and 49 0 nm. The fluorescence of these three bands can produce white light. . Another object of the present invention is to provide a method for preparing a high-brightness white light source, which must be compared with the conventional three-wavelength white light source, which must use three or more fluorescent materials that emit red, green, and blue light, respectively. The characteristic is that only two kinds of fluorescent materials need to be used, and one kind of fluorescent materials can emit two bands of fluorescence of three primary colors of red, green and blue at the same time, so it can be obtained by combining with other fluorescent materials that can emit another band. The three primary colors of white light. [Embodiment]

Page 10 572994 _Case No. 90123332__Year Month and Day ___ V. Description of the invention (4) In order for your review committee to better understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention However, the accompanying drawings are for reference and explanation only, and are not intended to limit the present invention. The invention relates to a method for preparing a white light source, which uses ultraviolet light as an excitation light source and is compatible with two kinds of fluorescent materials (fluorescent powder or powder), which can be excited by ultraviolet light of a selected wavelength to emit a main wavelength. 5 8 5 nm to 640 nm red light, 500 nm to 5 70 nm green light and 430 nm to 490 nm blue light, and one of the fluorescent materials can simultaneously emit red, green and blue three primary colors Two bands of fluorescent light, and the other fluorescent material emits fluorescent light outside the first two bands. Thus, by blending the mixing ratio of the two fluorescent materials, a high-brightness white light emitting element can be produced, such as White light emitting diode. The purpose of the method of the present invention is to produce a phosphor that emits two wavelengths simultaneously. The luminescence properties of the phosphor are obtained by adding or doping a relatively small amount of foreign ions to the host material, such as Eu3 + in γ2 03: Eu3 +. When an alien ion is bound or incorporated into a host lattice to form a position that can be excited to emit light, it is called an activation center. When a foreign ion is bound or incorporated into a host lattice and can transfer its excitation energy to a nearby activator, which then causes light emission, it is called a sensitive person, sometimes also called a secondary activator or sensitizer. Sometimes the activation center that can emit light has no significant absorption effect on the excitation energy, but the sensitive person can absorb the excitation energy and then pass through the energy transfer process to the activation center to make it emit its own characteristic fluorescence. Based on this principle, if a phosphor can be synthesized, which is added or doped with two different ions at the same time as the activation center, one can be obtained that can emit two

Page 11 572994 _Case No. 90123332_Year Month Date__ V. Description of the Invention (5) Fluorescent phosphors in the band. However, most foreign ions require different excitation wavelengths, so the feasibility of this method is not as high as expected. However, if the sensitive person is used in conjunction with the design of the activation center, the possibility of designing a two-band fluorescent powder can be increased. For example, when BaMgAl ^ OiJ ^ is used as the host lattice, divalent europium (Eu2 +) is added or replaced in the structure, and blue fluorescence can be obtained by ultraviolet light irradiation. However, if divalent europium and divalent manganese (Mn2 +) are added or replaced in the host lattice at the same time, in addition to the europium ion itself can emit blue fluorescent light, it can also be emitted by the light energy absorbed by the europium ion to be transferred to the manganese ion. Green light. Therefore, this phosphor only needs to be excited by ultraviolet light of one wavelength, and simultaneously emits blue-green fluorescent light which is mixed with blue and green. The aforementioned excitation light source can be generated by a light-emitting diode, an electron beam, or a plasma. The fluorescent material that can emit two-band fluorescence at the same time is (Ba! _XEux) (Mg ^ yMriy) A10O17, of which 0 <xS0.5; 0 < yS0 .5, or (Bai_xEux) (Mg2_yMny) Ali6〇27 'where 〇 < χ ^ 〇 · 5, 0 < y $ 0.5, the fluorescence emitted is blue-green light; it can emit fluorescence in another band of fluorescence The material is (Y2_xEux) 03, where 0 < XS 0 · 5, and (Y2_xEux) 02S, where 0 < χ € 0 · 5 or (Y3_xEux) Α15012, where 0 < xS0.5, the fluorescent light is red Or orange light. The following examples illustrate the phosphors that need to be synthesized and blended for the white light emitting device of the present invention. Embodiment 1 (white light source with high color temperature)

Page 12 572994 _ Case No. 9Q123332 V. Description of the invention (6) — Year and month _ 1 · Synthesis of a fluorescent powder with a formula Y2 03: Eu type, such as (Yi.gEUo.DO3 'The synthesis method can be used Solid state reaction method, chemical synthesis method, such as citrate gel method, co-precipitation method, etc. 2. Synthesis of a formula is BaMgAl1G017: Eu, Mη type fluorescent powder, such as CBauEUiKOCMgueMnuJ Al10〇17, the synthesis method can use solid state reaction Method, chemical synthesis method, such as citrate gel method, co-precipitation method, etc. 3. Measured at a wavelength of 610 nm (Yi9EU () i) 〇3 The excitation spectrum of the phosphor is shown in the first figure From this spectrum, it is known that this Y2O3: Eu-type phosphor can be excited by ultraviolet light. 4. Measure the emission of the above (Y ^ Euo.JO3 phosphor with the ultraviolet light of 3 96 nm as the excitation source). The spectrum, as shown in the second figure, shows that this Υζ〇3: Eu-type phosphor can produce red fluorescence. The data of the emission spectrum was calculated by the International Illumination Commission (^ 〇11111 ^ 5 ^ 〇11111) in 1991. «|: 6]: 11 & _ ^ 〇11 £ 116 del 'Eclai rage (CIE) formula for chroma coordinate diagram (chr〇maticity diagram) The chromaticity coordinates represented by this phosphor are marked and marked with A in the third figure. 5 · Measured at a wavelength of 4 8 8 nm (BauEuG.OUgGjMn.,) Al1G〇17 fluorescence The excitation spectrum of the powder, as shown in the fourth figure, shows that this BaMgAlM ": Eu, Mn type phosphor can be excited by external light. B · Using ultraviolet light with a wavelength of 3 9 6 nm as the excitation source measurement (BaG 9Eu 〇 "(Mg. 96MnQ 〇4) A11g〇17 emission spectrum of the fluorescent powder, such as: 丄 From the spectrum, we can know that this fluorescent powder can produce blue light and green light at the same time (that is, blue j,), and the emission spectrum of The data is converted to the ^ degree coordinates represented by this phosphor, and marked in the third figure with point B.

Page 13 572994 _Case No. 90123332_Year Month and Day__ V. Description of the invention (7) 7. Draw the connection between the two points A and B with a dashed line in the chromaticity coordinate chart, and find that this mixed connection of color and light can be According to the white area in the chromaticity coordinate chart, which is based on the principle of color and light mixing, when the optic nerve is stimulated by the color represented by point A (in this example, red) and the color represented by point B (in this example, blue-green), Can produce white vision. In addition, because the position of point B is more blue light, the part of the line passing through the white light area is white light with a higher color temperature. Therefore, the two fluorescent powders obtained by the method of the present invention are mixed according to an appropriate ratio, and an ultraviolet light emitting diode capable of emitting an appropriate wavelength (in this example, 396 nm) is used as an excitation light source. After being appropriately packaged, By applying an appropriate current, a white light emitting diode with a light emitting characteristic can be obtained. The package can be a lamp, a surface mount device (SMD), or a chip on board (COB). Example 2 (White light source with low color temperature) 1. A Y2O3: Eu type fluorescent powder is synthesized, such as (Yi.gEua.JOs). The synthesis method can use solid state reaction method, chemical synthesis method, such as lemon Sodium gel method, co-precipitation method, etc. 2. Synthesis of a formula is BaMgA 11 () 017: Eu, Mη-type fluorescent powder, such as (Ba〇9Eu〇i) (Mg〇93Mn〇07) Α1ι〇〇 ΐ7 'The synthesis method can use solid cancer reaction method, chemical synthesis method, such as citrate gel method, co-precipitation method, etc. 3. Measured at the wavelength of 610 nm (YuEuo.JOs fluorescent powder excitation The spectrum, as shown in the first figure, shows that this Y203: Eu-type phosphor can be excited by ultraviolet light. 4 · Measure the emission spectrum of the above-mentioned phosphor with ultraviolet light with a wavelength of 396 nm as the excitation source. Conversion of emission spectrum data

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The chromaticity coordinates represented by this phosphor are formed, and are marked in the eighth figure with 4 points. Based on this decision, scan 5. The results shown in the excitation spectrum of (B ^ uEuuMMgusMnu?) Ai1Q〇17 fluorescent powder and the excitation spectrum of (Y ^ Euo.JO3 fluorescent powder) measured with a wavelength of 488 nm as the detection point. The excitation wavelength at the time of the spectrum is ultraviolet light of 396. For example, 7 · 6. Using ultraviolet light with a wavelength of 39 6 nm as the excitation source measurement (BauEuo ") (Mg. ΜMπο · ??) A11G017 phosphor emission spectrum_ Figure \ It can be known from the spectrum that the phosphor can generate blue light and green light (that is, blue-green light) at the same time. The data of the emission spectrum is converted into the chromaticity coordinates represented by the phosphor, and the point C is marked in the eighth figure. 7. In the chromaticity coordinate graph, a dotted line is drawn between the two points A and C, and it is found that this connection can pass through the white block in the chromaticity coordinate graph. In addition, because the position of point c is relatively It is greenish light, so the part of the line that passes through the white light area is white light with a lower color temperature. Therefore, 'mixing the two fluorescent powders obtained by the method of the present invention at an appropriate ratio' can emit an appropriate wavelength (this example (396 nm) UV light emitting diode as excitation light source, after proper packaging Give proper current to obtain a white light emitting diode of the light emitting characteristics. The package may be

LamP, surface mount device (SMD), or chip on board (COB). In summary, compared to the conventional three-wavelength white light source, the white light generated by mixing ultraviolet light with phosphors that can generate three (or more) blue, green, and red (or more) at the same time is mixed with light. The method of the present invention has the following advantages:

H1

Page 15 572994 _Case No. 90123339 Amendment 5 、 Explanation of the invention (9) 1 · Because the method of the present invention uses only one kind of fluorescent powder, the restriction on the selection of the wavelength of the excitation light is relaxed, and a wider application can be obtained range. 2. Although the method of the present invention uses only two kinds of fluorescent powders, it still has the characteristics of white light obtained by mixing the three primary colors in essence, such as high color rendering, and maintains a relatively high luminous efficiency, which does not decrease due to the reduction of powder types. . 3. Since the present invention uses only two kinds of phosphors, the manufacturing process is simplified and the manufacturing cost is low. At the same time, the convenience for white light deployment is greatly improved, which is of great value for industrial applications. Therefore, the present invention fully meets the requirements for patent application. Therefore, if you file an application in accordance with the Patent Law, please check and approve the case in detail to protect the rights and interests of the inventor. Instructions. According to the above description, it is only a specific embodiment of the present invention, but the features of the present invention are not limited to this. Any of them can be made by adding two kinds of optical active centers or sensitizers in the host lattice at the same time. A fluorescent powder that emits two colors of red (585 nm to 640 nm), green (500 nm ^ 570 nm), and blue (430 nm to 490 nm). Combined with another fluorescent powder, it can emit fluorescence that belongs to the two primary colors outside the first two bands. And two kinds of phosphor powders are blended according to appropriate proportions, so as to show excellent light emitting characteristics such as high color uniformity and high brightness. The changes or modifications implemented to produce a white light emitting element are covered by the patent scope of the following case. Inside.

572994 _Case No. 90123332_ Year Month Revision _ Brief Description of the Drawings [Simplified Description of the Drawings] The first diagram is measured with a wavelength of 610 nm (the excitation spectrum of YuEua.JOs fluorescent powder. The second diagram is The emission spectrum (YuEuo.JOs fluorescent powder) was measured with a wavelength of 3 96 nm as the excitation source. The third graph shows the chromaticity coordinates A and B of the two phosphors calculated from the emission spectra as the endpoints The connected dashed line can pass the white area of the southern color temperature of the chromaticity coordinate chart. The fourth chart is measured with a wavelength of 48 8 nm (Bao gEUo DCMgo geMrio o JAlioOn). The fifth chart is based on the wavelength. 3 9 6 nm is the emission spectrum (Bao gEuo OCMgo geMno oJAlioOn). The sixth figure is the excitation spectrum (Bao gEuo DCMgo gsMno odAlioOH) measured with a wavelength of 48 8 nm. The seventh diagram is the emission spectrum of (Ba〇9Eu〇i) (Mg〇93Mn〇〇7) Ali〇〇i7 glare powder measured with a wavelength of 396 nm as the excitation source. The calculated chromaticity coordinates A and C of the two phosphors are White blocks by a dotted line may be a low color temperature of the chromaticity coordinates of FIG.

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Claims (1)

572994 90123332 Private Qin Day_Modify Taiyi ^ Γ · A method for preparing white light source, which uses ultraviolet light source with two kinds of powder with fluorescent characteristics that can be directly excited by ultraviolet light to make high-brightness white light Light-emitting element, the aforementioned first powder is (Ba ^ EUx) (Mg! _YMny) A110017, where 0 < χ ^ 0 · 5; 0 < yS0.5, or (Ba! _XEux) (Mg2-yMny) A116027 , Where 0 < χ $ 0 · 5; 0 < y € 0.5, the fluorescent light emitted is blue-green; the second phosphor is (Y2-xEux) 03, where 0 < XS 0 · 5, (Y2_xEux ) 02S, where 0 < xS 0.5 or (Y3_xEux) A15 〇12, where 〇 < X $ 0.5, the fluorescence emitted is red or orange. 2 · The method for preparing a white light source as described in item 1 of the scope of the patent application, where one of the two powders with fluorescent properties is to add two or more optical active centers or sensitizers to the body at the same time The phosphor produced in the crystal lattice can emit two colors of red, green, and blue light at the same time after being excited by ultraviolet light. The other phosphor can emit light outside the first two bands. Fluorescence of three primary colors. 3. The method for preparing a white light source as described in item 1 of the scope of patent application, wherein the powder system with fluorescent properties is prepared by a solid state reaction method or a chemical synthesis method. 4 · The method for obtaining a white light source as described in item 1 of the scope of the patent application, in which two kinds of powders can be mixed in different proportions, combined with UV light that can emit light as an excitation light source, and after encapsulation, an electric current is obtained to obtain a White light emitting element with excellent light emitting characteristics. 5. The method for producing a white light source as described in item 4 of the scope of the patent application, wherein the excitation light source can be generated by a light emitting diode, an electron beam or a plasma. 6 · White light source can be made as described in item 4 of the scope of patent application Page 572 994 Page 19