JP2009079094A - Phosphor and led lamp using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a phosphor capable of effectively complementing a red luminescent component and an LED lamp using the phosphor for emitting light excellent in color rendering properties. <P>SOLUTION: The phosphor has a composition represented by a chemical formula: Ln<SB>3</SB>Mn<SB>x</SB>Al<SB>5-x-y</SB>Si<SB>y</SB>O<SB>12</SB>:Ce (wherein Ln is at least one kind of element selected among Y, Lu and Gd; x and y are coefficients each satisfying relational expressions 0<x≤2, 0<y≤2, and 0.9<x/y≤1.1). The LED lamp is formed when the phosphor and a blue light-emitting diode having a light emission peak wavelength at 430-470 nm are combined together. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a phosphor and an LED lamp using the same, and more particularly to an LED lamp comprising a combination of a blue light emitting diode and a phosphor that emits yellow-red light by absorbing light emitted from the diode. The present invention relates to a phosphor that can emit light having excellent color rendering when used as a lamp phosphor, and an LED lamp using the phosphor.

  A light emitting diode (LED: Light Emitting Diode, hereinafter also referred to as an LED chip) is a light emitting element that acts as a light source when a voltage is applied, and includes electrons and holes near the contact surface (pn junction) of two semiconductors. It is a light emitting element using the light emitted by recombination. Since this light-emitting element is small and has high conversion efficiency of electric energy into light, it is widely used as home appliances, illuminated operation switches, and LED displays.

  Also, unlike a light bulb that uses a filament, it is a semiconductor element, so there is no so-called “bulb break”, excellent initial drive characteristics, and excellent durability in vibration and repeated ON / OFF operations. It can also be used as a backlight for display devices such as dashboards. In particular, since bright light emission with high saturation can be obtained without being affected by sunlight, the use is expanded to display devices, traffic display devices, traffic lights and the like installed outdoors.

  That is, a light emitting diode is a semiconductor diode that emits light, and converts electrical energy into ultraviolet light or visible light. In particular, in order to use visible light, it is also widely used as an LED lamp in which a light-emitting chip formed of a light-emitting material such as GaP, GaAsP, GaAlAs, GaN, or InGaAlP is sealed with a transparent resin. In addition, it is also widely used in display-type LED lamps in which the light emitting material is fixed to the upper surface of a printed circuit board or a metal lead and sealed with a resin case in which numbers and letters are formed.

  In addition, it is possible to appropriately adjust the color of the emitted light by including various phosphor powders in the front surface or front resin of the light emitting chip. That is, the light emission color of the LED lamp can reproduce light emission in the visible light region depending on the usage from blue to red. In addition, since the light emitting diode is a semiconductor element, it has a long life and high reliability, and when used as a light source, the replacement frequency due to the failure is also reduced. Therefore, the portable communication device, the personal computer peripheral device, the OA It is widely used as a component of various display devices such as devices, household electric devices, audio devices, various switches, and backlight light source display plates.

  Recently, however, the color sensation of users of the various display devices has been improved, and various display devices have been required to have a function capable of reproducing subtle hues with higher definition and a uniform appearance of LED lamps. I came. In particular, the demand for white LED lamps is remarkable in mobile phone backlights and in-vehicle lamps. In the future, demand for replacement of fluorescent lamps is expected to grow significantly. Various technical improvements have been tried for high white color rendering and uniform appearance.

  In addition, the RoHS regulation (Directive on Restriction of Use of Specific Hazardous Substances Included in Electrical and Electronic Equipment) enforced in the EU (European Union) in July 2006 prohibits the use of mercury in electrical products, In the near future, it is expected that white light emitting LED lamps that do not use mercury in lighting equipment will replace conventional fluorescent lamps that contain mercury vapor.

  Currently, white light-emitting LEDs (light-emitting devices) that are practically used or tried include blue light-emitting diodes and yellow light-emitting phosphors (YAG), and in some cases, red light-emitting phosphors. There exists a device (referred to as type 1), a light emitting device (referred to as type 2) of a combination of ultraviolet or violet light emitting diodes and blue, yellow and red phosphors. At present, Type 1 is most popular because it has an advantage of higher brightness than Type 2.

  Examples of yellow phosphors used in the type 1 light emitting device include cerium activated yttrium aluminate phosphor (YAG), cerium activated terbium aluminate phosphor (TAG), and alkaline earth silicate. A phosphor material such as phosphor (BOSS) has been put into practical use.

  Among the above phosphor materials, YAG and BOSS are generally known phosphors before being used in combination with light emitting diodes, and have been used in flying spot scanners, fluorescent lamps, etc., or applied products. Application has been attempted. These phosphors have already been put into practical use as backlight phosphors for mobile phones, but are being improved daily to further increase demand for lighting devices and automobile headlamps.

The results of the improvement aimed at practical use are introduced in the following patent documents. Specifically, the improvement history and results of the BOSS phosphor are disclosed in Patent Document 1 below. On the other hand, with regard to aluminate phosphors such as YAG and TAG, improvement processes and results are disclosed in the following Patent Documents 2 to 21 and the like. Specifically, attempts are being made to replace some of the basic components of the phosphor with other types of elements, optimize the amount of substitution, and adjust the type and amount of activator. .
Japanese Patent No. 3749243 JP 2006-332692 A JP 2006-299168 A JP 2006-41096 A JP 2005-317985 A JP 2005-8844 A JP 2003-179259 A JP 2002-198573 A JP 2002-151747 A Japanese Patent Laid-Open No. 10-36835 JP 2006-321974 A JP 2006-265542 A JP 2006-213893 A JP 2006-167946 A JP 2005-243699 A JP 2005-150691 A JP 2004-115304 A JP 2006-324407 A JP 2006-25336 A JP 2005-235847 A JP 2002-42525 A

  However, the problem with the conventional type 1 white LED, which is formed by combining the above blue light emitting diode and a yellow light emitting phosphor such as BOSS or YAG, TAG, etc., is superior in luminance characteristics. ) Is insufficient, and when used for illumination, the color rendering properties for reproducing the color of the illumination object as a more natural color are reduced. For this reason, there is a problem that it becomes unsuitable as a lighting device for sales stores of goods where natural color is particularly important and a lighting device for workplaces that require distinction of the color of the goods. Improvement continues.

  The present invention has been made in order to solve the above-mentioned problems. In particular, the present invention provides a phosphor capable of effectively supplementing a red light-emitting component that has been apt to be deficient in the past, and this phosphor is used as a fluorescent lamp of an LED lamp. It aims at providing the LED lamp which can discharge | emit the light emission excellent in color rendering property by using as a body.

  In order to achieve the above object, the present inventors prepared phosphors having various compositions, substituted some of the main components of conventional phosphors with other elements, and the types and amounts of substitution elements were The effect of phosphors on the emission characteristics was compared and examined by a series of experiments. As a result, a phosphor having a large amount of red light-emitting component can be obtained particularly when a part of aluminum component constituting YAG which is an aluminate phosphor is replaced with a predetermined amount of manganese (Mn) and silicon (Si). On the other hand, it has been found that by combining this phosphor with a blue light-emitting diode having a specific emission peak wavelength, a white LED lamp having high luminance equal to or higher than that of the prior art and high color rendering properties can be obtained for the first time. The present invention has been completed based on the above findings.

That is, the phosphor according to the present invention has a composition represented by the following chemical formula: Ln ₃ Mn _x Al _5-xy Si _y O ₁₂ : Ce
(However, Ln is at least one element selected from Y, Lu and Gd, and x and y are 0 <x ≦ 2, 0 <y ≦ 2, 0.9 ≦ x / y ≦ 1. It is a coefficient satisfying the relational expression 1)).

  That is, the phosphor according to the present invention is configured by substituting a predetermined amount of manganese (Mn) and silicon (Si) for a part of an aluminum component which is a main component of a conventional YAG phosphor. The substituted Mn and Si components have an action of shifting the emission peak wavelength of the phosphor to the longer wavelength side, and a phosphor that inevitably emits yellow-red light with a large amount of the red light emitting component that is a long wavelength component is obtained.

  The substitution amounts of the Mn and Si components are each defined as 2 or less in terms of atomic ratio. If the amount of substitution of Mn and Si components is excessive so that the atomic ratio exceeds 2, respectively, the basic crystal structure of the YAG phosphor is distorted and the emission characteristics are deteriorated. The amount of substitution is set to 2 or less, but is more preferably 0.01 or more and 1 or less.

  In addition, when either of the above Mn and Si components is added alone, there is a certain shift effect of the emission peak wavelength, but the shift effect is particularly prominent when both components are used in substantially equal amounts by atomic ratio. Become. Therefore, the blending ratio (x / y) of both is specified in the range of 0.9 to 1.1.

  In the phosphor, it is preferable that a part of the Mn is replaced with Mg. Since Mg may have an action of shifting the emission peak wavelength of the phosphor to the longer wavelength side in cooperation with Si in the same manner as Mn, even if it is substituted in the range of 10 to 70 atomic% with respect to the amount of Mn. good. If the amount of substitution is less than the lower limit, the shift effect is small. On the other hand, if the amount of substitution exceeds the upper limit, similarly to the above, the basic crystal structure of the phosphor is distorted and the light emission characteristics are deteriorated.

  Furthermore, the LED lamp according to the present invention is characterized by comprising a combination of a blue light emitting diode having an emission peak wavelength of 430 to 470 nm and the phosphor described above. According to the LED lamp of the present invention, a blue light emitting diode having an emission peak wavelength of 430 to 470 nm and a phosphor that emits yellowish red light by shifting the emission peak wavelength to a long wavelength side of approximately 570 nm or more. As a result, the red light-emitting component that tends to be deficient in the prior art is effectively compensated, and a white LED lamp having high brightness and color rendering properties equal to or higher than those in the prior art can be obtained.

  According to the phosphor according to the present invention and the LED lamp using the phosphor, a part of the aluminum component which is the main component of the conventional YAG phosphor is replaced with a predetermined amount of manganese (Mn) and silicon (Si). To be configured. The emission peak wavelength of the phosphor shifts to the longer wavelength side, and a phosphor that emits yellow-red light that sufficiently compensates for the red light-emitting component that tends to be insufficient in the past can be obtained. Therefore, since this phosphor and a blue light emitting diode having a predetermined emission peak wavelength are combined, a white LED lamp having both high luminance equal to or higher than conventional and excellent color rendering is realized. It is possible to provide a high-quality light source in lighting and other application fields where high brightness and color rendering of white light are required. In addition, the phosphor does not contain mercury and is expected to grow in demand as a product suitable for environmental conservation.

  Next, embodiments of the present invention will be specifically described below.

  The composition of the phosphor used in the LED lamp of the present invention is represented by the following chemical formula.

_{Ln 3 Mn x Al 5-x} -y Si y O 12: Ce
(However, Ln is at least one element selected from Y, Lu and Gd, and x and y are 0 <x ≦ 2, 0 <y ≦ 2, 0.9 ≦ x / y ≦ 1.1. A number that satisfies the relationship). That is, the phosphor of the present invention is a cerium (Ce) activated aluminate phosphor in which a part of the Al component constituting the YAG phosphor is substituted with Mn and Si.

FIG. 1 shows a comparison of emission spectra of a total of three types of phosphors, that is, two types of phosphors according to an embodiment of the present invention and a conventional YAG phosphor. The spectrum curve A corresponds to a conventional phosphor YAG having a composition of Y ₃ Al ₅ O ₁₂ : Ce, and the spectrum curve B is a composition of Y ₃ Mn _0.03 Al _4.9 Si _0.03 O ₁₂ : Ce. The spectral curve C corresponds to the phosphor according to another embodiment having the composition Y ₃ Mn _0.05 Al _4.6 Si _0.05 O ₁₂ : Ce. Is.

  As is clear from the results shown in FIG. 1, as the substitution amount of Mn and Si with respect to the Al component increases, in addition to the emission spectrum of the conventional Ce-activated phosphor, the peak estimated to be the emission of Mn and silicon ( Wavelengths: 580 to 590 nm) appear to overlap. Since the emission peak of the conventional Ce-activated phosphor exists in a short wavelength region around 540 nm, the spectral shape with such a long wavelength light component is a technical problem to be solved in the conventional YAG phosphor.

  On the other hand, in the present embodiment, as apparent from the spectrum curves B and C, the emission peak is effectively shifted to the long wavelength side, so that the shortage of the red emission component is compensated. It is possible to provide a high-quality white LED lamp having excellent properties.

In general, as a countermeasure for reinforcing the red light emitting component of the yellow light emitting phosphor, a part of yttrium (Y) constituting the YAG (Y ₃ Al ₅ O ₁₂ : Ce) phosphor is replaced with gadolinium (Gd) ( Y, Gd) ₃ Al ₅ O ₁₂ : Ce is made into a phosphor having a composition of Ce and has been commercialized, but both the emission luminance and the color rendering property of the emission tend to be lowered.

  According to the phosphor according to the present embodiment, the emission spectrum of the phosphor is changed to a reddish one, which makes it possible to realize efficiency and color rendering that are equal to or higher than those in the past.

  The LED lamp according to the present invention is configured by combining a blue light-emitting diode having an emission peak wavelength of 430 to 470 nm and one or more phosphors of the present invention. As a specific configuration of the LED lamp, for example, it is configured to have a cross section as shown in FIG. That is, the LED lamp 1 includes a substrate 2 on which lamp components are mounted, a blue light-emitting diode (light-emitting element) 3 mounted on the substrate 2 and having an emission peak wavelength of 430 to 470 nm, and an upper surface side of the light-emitting diode 3. The phosphor layer 4 is disposed and formed by embedding the phosphor according to the present invention in a resin, and a resin frame 5 that supports a light emitting portion composed of the light emitting diode 3 and the phosphor layer 4. Further, the electrode portion 6 and the light emitting diode 3 disposed on the upper portion of the resin frame 5 are electrically connected by a bonding wire 7.

  In the LED lamp, electrical energy applied to the light emitting diode 3 from the electrode portion 6 via the bonding wire 7 is converted into blue light by the light emitting diode 3, and part of the light is located above the light emitting diode 3. The phosphor layer 4 converts the light into light having a longer wavelength, and as a total of the light emitted from the light emitting diode 3 and the light emitted from the phosphor layer 4, white light is emitted outside the LED lamp. ing.

  FIG. 3 is a graph showing an example of an emission spectrum of a white light emitting LED lamp obtained by combining the phosphor according to the present invention as the phosphor of the LED lamp having the configuration shown in FIG. As is apparent from the emission spectrum shown in FIG. 3, a blue light emitting diode having an emission peak wavelength of 460 nm is caused to emit light when a current value of 20 mA is applied, and at the same time, chromaticity (0.300 to 0.350, 0. 300 to 0.350) when converted to white light, the peak wavelength of the blue light emitting component becomes 460 nm, and at the same time, a spectrum having a wide shape in the wavelength region indicating the red light emitting component from green on the longer wavelength side appears. ing. Due to this spectral shape, an excellent characteristic value having a luminance of 450 mcd or more and an average color rendering index (Ra) representing the quality of white light when used as illumination is 75 or more.

  Next, embodiments of the present invention will be described more specifically with reference to the following examples. That is, phosphor particles having various compositions were prepared, and the LED lamps according to the respective examples were prepared by embedding the phosphor particles with a resin as shown in FIG. evaluated.

  The LED lamp according to each example has the cross-sectional shape shown in FIG. 2, and emits light with a current value of 20 mA in a state where a light emitting chip having a size of 300 μm square as the light emitting diode 3 is disposed on the concave bottom portion of the resin frame 5 The chip was allowed to emit light and its characteristics were evaluated. The emission peak wavelength of the light emitting diode 3 was about 460 nm. The light emission characteristics as a white LED lamp were measured using a COMPACT ARRAY SPECTROMETER (model: CAS-140, manufactured by Instrument Systems) and an MCPD apparatus (produced by Otsuka Electronics Co., Ltd.).

  Here, the manufacturing method of each LED lamp is as follows. That is, 10 to 20% by mass of a silicone resin was mixed with the phosphor of the present invention to prepare a slurry, which was then dropped on the upper surface side of the light emitting diode. Then, it heat-processed at the temperature of 100-150 degreeC, the silicone resin was hardened, and the LED lamp which concerns on each Example was prepared. In addition, about the application quantity of the slurry in the said process, fluorescent quantity of a required quantity is beforehand taken so that the chromaticity of a LED lamp may enter into the range of x = 0.30-0.35, y = 0.30-0.35. A body is prepared and slurry preparation is performed. In each example, only the yellow-orange light-emitting phosphor of the present invention was used as the phosphor, but two or more B, G and R phosphors including the phosphor defined in the present invention were added, You may prepare so that it may become a predetermined luminescent color.

[Example 1]
Cerium-activated yttrium manganese aluminosilicate (composition formula: Y ₃ Mn _0.05 Al _4.9 Si _0.05 O ₁₂ : Ce) as a yellow-orange light-emitting phosphor was mixed with a silicone resin at a concentration of 15% by mass. . A white light emitting LED lamp according to Example 1 was prepared by applying the slurry on a light emitting diode in advance so as to have a predetermined light emission chromaticity and then curing the resin by heat treatment at a temperature of 140 ° C.

[Example 2]
Cerium-activated yttrium manganese aluminosilicate (composition formula: Y ₃ Mn _0.02 Al _4.96 Si _0.02 O ₁₂ : Ce) 9 as a yellow-orange light-emitting phosphor was mixed with a silicone resin at a concentration of 15% by mass. did. A white light emitting LED lamp according to Example 2 was prepared by applying this slurry on a light emitting diode in advance so as to have a predetermined light emitting chromaticity, and then heat-treating the resin at a temperature of 140 ° C. to cure the resin.

[Example 3]
Yellow-orange light emitting cerium-activated yttrium gadolinium manganese alumino silicate as a phosphor (composition _{formula: Y 2.5 Gd 0.5 Mn 0.05 Al} 4.9 Si 0.05 O 12: Ce) and a silicone resin 15 Mixed at a concentration of mass%. A white light emitting LED lamp according to Example 3 was prepared by applying the slurry on a light emitting diode in advance so as to have a predetermined light emission chromaticity, and then heat-treating the resin at a temperature of 140 ° C. to cure the resin.

[Example 4]
Cerium activated lutetium manganese aluminosilicate as yellow-orange emitting phosphor (composition _{formula: Lu 3 Mn 0.1 Al 4.8 Si} 0.1 O 12: Ce) were mixed at a concentration of silicone resin and 15 wt% . A white light emitting LED lamp according to Example 4 was prepared by applying this slurry on a light emitting diode in advance so as to have a predetermined light emission chromaticity, and then heat-treating the resin at a temperature of 140 ° C. to cure the resin.

[Example 5]
Yellow-orange light emitting cerium-activated yttrium lutetium, manganese alumino silicate as a phosphor (composition _{formula: Y 1.5 Lu 1.5 Mn 0.07 Al} 4.86 Si 0.07 O 12: Ce) and a silicone resin 15 Mixed at a concentration of mass%. A white light emitting LED lamp according to Example 5 was prepared by applying this slurry on a light emitting diode in advance so as to have a predetermined light emitting chromaticity, and then curing the resin by heat treatment at a temperature of 140 ° C.

[Comparative Example 1]
Cerium-activated yttrium gadolinium aluminate (composition formula: (Y, Gd) ₃ Al ₅ O ₁₂ : Ce) as a yellow light-emitting phosphor was mixed with a silicone resin at a concentration of 15% by mass. Next, after applying this slurry on the light emitting diode, the resin was cured by heat treatment at a temperature of 140 ° C. to prepare a white light emitting LED lamp according to Comparative Example 1 having a conventional configuration.

[Example 6]
Cerium-activated yttrium gadolinium manganese aluminosilicate (composition formula: Y _2.2 Gd _0.8 Mn _0.01 Al _4.98 Si _0.01 O ₁₂ : Ce) as a yellow-orange light-emitting phosphor and silicone resin 15 Mixed at a concentration of mass%. A white light emitting LED lamp according to Example 6 was prepared by applying this slurry on a light emitting diode in advance so as to have a predetermined light emission chromaticity and then curing the resin by heat treatment at a temperature of 140 ° C.

[Example 7]
Cerium-activated lutetium manganese aluminosilicate (composition formula: Lu ₃ Mn _0.2 Al _4.6 Si _0.2 O ₁₂ : Ce) as a yellow-orange light-emitting phosphor was mixed with a silicone resin at a concentration of 15% by mass. . A white light emitting LED lamp according to Example 7 was prepared by applying this slurry on a light emitting diode in advance so as to have a predetermined light emission chromaticity, and then heat-treating the resin at a temperature of 140 ° C. to cure the resin.

[Example 8]
Cerium-activated yttrium manganese aluminosilicate (composition formula: Y ₃ Mn _0.03 Al _4.94 Si _0.03 O ₁₂ : Ce) as a yellow-orange light-emitting phosphor was mixed with a silicone resin at a concentration of 15% by mass. . A white light emitting LED lamp according to Example 8 was prepared by applying this slurry on a light emitting diode in advance so as to have a predetermined light emission chromaticity, and then curing the resin by heat treatment at a temperature of 140 ° C.

[Example 9]
Cerium-activated lutetium manganese aluminosilicate (composition formula: Lu ₃ Mn _0.4 Al _4.2 Si _0.4 O ₁₂ : Ce) as a yellow-orange light-emitting phosphor was mixed with a silicone resin at a concentration of 15% by mass. . A white light emitting LED lamp according to Example 9 was prepared by applying this slurry on a light emitting diode in advance so as to have a predetermined light emission chromaticity and then curing the resin by heat treatment at a temperature of 140 ° C.

[Example 10]
Yellow-orange light emitting cerium-activated yttrium gadolinium lutetium, manganese alumino silicate as a phosphor (composition _{formula: Y 2 Gd 0.5 Lu 0.5 Mn} 0.02 Al 4.96 Si 0.02 O 12: Ce) Silicone The resin was mixed at a concentration of 15% by mass. A white light emitting LED lamp according to Example 10 was prepared by applying this slurry on a light emitting diode in advance so as to have a predetermined light emission chromaticity, and then heat-treating the resin at a temperature of 140 ° C. to cure the resin.

[Comparative Example 2]
Europium activated strontium barium orthosilicate (composition formula: (Sr, Ba) ₂ SiO ₄ : Eu) as a yellow light emitting phosphor was mixed with a silicone resin at a concentration of 15% by mass. Next, after applying this slurry on the light emitting diode, a white light emitting LED lamp according to the conventional comparative example 2 was prepared by heat-treating the resin at a temperature of 140 ° C. to cure the resin.

  In Examples 6 to 10, a light emitting diode having a light emitting diode peak value of 465 nm was used.

About the white light emitting LED lamp which concerns on each Example and comparative example prepared as mentioned above, the electric current of 20 mA was sent, it was made to light, and the luminance, the average color rendering index, and chromaticity of the light emission were measured. The chromaticity was in the range of x = 0.30 to 0.35, y = 0.30 to 0.35 as described above in each of the examples and comparative examples, and was almost the same value. The measurement results of the light emission luminance and the average color rendering index in each white light emitting LED lamp are shown in Table 1 below.

  As is clear from the results shown in Table 1 above, in the LED lamps according to the respective examples using the phosphors constituted by replacing a part of the aluminum component with a predetermined amount of manganese (Mn) and silicon (Si). Since the emission peak wavelength of each phosphor shifts to the longer wavelength side, a phosphor emitting yellow-red light that sufficiently supplements the red light-emitting component that has been insufficient in the past has been obtained. Therefore, since this phosphor is combined with a blue light emitting diode having a predetermined emission peak wavelength, a white LED lamp having both high luminance and color rendering properties equal to or higher than those of the prior art is obtained.

  On the other hand, in the white light emitting LED lamp according to Comparative Example 1 using the phosphor in which a part of the Al component is substituted with gadolinium (Gd), the shift amount of the emission peak wavelength to the long wavelength side in the phosphor is insufficient. Therefore, it was reconfirmed that the effect of improving the luminance was small, and in particular, the effect of improving the color rendering was small.

Further, in a white light emitting LED lamp according to Comparative Example 2 using a conventional europium activated strontium barium orthosilicate (composition formula: (Sr, Ba) ₂ SiO ₄ : Eu) as a yellow light emitting phosphor, silicon is used. Although it contains components, it has been found that there are few long-wavelength light components and the color rendering property of light emission remains low.

  Next, an example of a phosphor in which a part of Mn, which is an essential component in the phosphor according to the present invention, is substituted with Mg, and an LED lamp using the phosphor will be described.

[Example 11]
As shown in Table 2, various phosphors having a composition in which a part of Mn is substituted with Mg are prepared, and each phosphor is embedded in the upper surface side of the light emitting diode 3 with a resin under the same conditions as in Example 1 to phosphor. By forming the layer 4, LED lamps having the same structure as that shown in FIG. 2 were prepared. And about each prepared LED lamp, the light emission characteristic was measured on the same conditions as Example 1, and the result shown in following Table 2 was obtained.

  As is apparent from the results shown in Table 2 above, red light components are particularly effective in LED lamps using phosphors in which Mn and Si are substituted for Al components and part of Mn is substituted with Mg. It has been found that the color rendering properties of light emission are further improved.

  As described above, according to the LED lamp according to each embodiment, the phosphor of each embodiment having an increased amount of red light emission component is combined with the blue light emitting diode having a predetermined emission peak wavelength. In addition, high brightness equal to or better than conventional ones and excellent color rendering are realized, and it is possible to provide a high-quality light source in general lighting and other application fields that require high brightness and color rendering of white light. Become. In addition, the phosphor does not contain mercury and can be expected to grow as an environmentally friendly product.

The graph which compares and shows the emission spectrum of a total of 3 types of fluorescent substance of 2 types of fluorescent substance concerning embodiment of this invention, and the conventional YAG type | system | group fluorescent substance. Sectional drawing which shows the structure of one Example of the LED lamp which concerns on this invention. The graph which shows an example of the emission spectrum of the white light emission LED lamp obtained combining the fluorescent substance which concerns on this invention as a fluorescent substance of an LED lamp.

Explanation of symbols

1 LED lamp 2 substrate 3 light emitting diode (light emitting element, LED chip)
4 Phosphor Layer 5 Resin Frame 6 Electrode 7 Bonding Wire

Claims (3)

The composition is represented by the following chemical formula: Ln ₃ Mn _x Al _5-xy Si _y O ₁₂ : Ce
(However, Ln is at least one element selected from Y, Lu and Gd, and x and y are 0 <x ≦ 2, 0 <y ≦ 2, 0.9 ≦ x / y ≦ 1. A phosphor satisfying the relational expression of 1). The phosphor according to claim 1, wherein a part of said Mn is substituted with Mg. An LED lamp comprising a combination of a blue light emitting diode having an emission peak wavelength of 430 to 470 nm and the phosphor according to claim 1.

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