JP2011066228A - White led light source, backlight unit, liquid crystal panel, and liquid crystal tv - Google Patents

Abstract

A white LED light source, a backlight unit, a liquid crystal panel, and a liquid crystal TV having high luminous efficiency are provided.
A white LED light source 1 according to the present invention receives a blue light emitting diode chip 20B that emits blue light, an ultraviolet light emitting diode chip 20UV that emits ultraviolet light, and ultraviolet light to emit green light and red light. A green-red light emitting diode 10GR including the green-red phosphor layer 30GR is mounted on the substrate 40.
[Selection] Figure 1

Description

  The present invention includes a blue light emitting diode chip that emits blue light, an ultraviolet light emitting diode chip that emits ultraviolet light, and a green phosphor powder and a red phosphor powder that emit light by the ultraviolet light, and emits white light. More specifically, the present invention relates to a white LED light source that emits white light, a backlight unit, a liquid crystal panel, and a liquid crystal TV including a blue light emitting diode chip and a green red light emitting diode using an ultraviolet light emitting diode chip.

  A light emitting diode (LED: Light Emitting Diode) is a semiconductor diode that emits light, and converts electrical energy into UV light or visible light.

  Conventionally, light emitting devices using LED light sources have been widely used. The LED light source is formed by forming a light emitting chip using a substrate such as a transparent substrate and a light emitting material such as GaP, GaAsP, GaAlAs, GaN, InGaN, AlGaN, InGaAlP, and coating the light emitting chip with a transparent resin. Can be obtained.

  Moreover, the LED light source can adjust the color of radiated light by containing various fluorescent substance powder in sealing resin. That is, by using a combination of a light-emitting chip and a phosphor powder that absorbs light emitted from the light-emitting chip and emits light in a predetermined wavelength region, light emitted from the light-emitting chip and phosphor powder are emitted. It is possible to emit light in the visible light region or white light by the action of the light.

  As a white light emitting LED light source that emits white light, for example, Patent Document 1 (US Patent Application Publication No. 2006/0249729) discloses a blue light emitting diode chip and a green light emitting phosphor that receives blue light and emits light. And a white light emitting LED light source that combines an ultraviolet light emitting diode chip and a red light emitting phosphor that emits light by receiving ultraviolet light.

  White LED light sources used as light sources for liquid crystal panel backlight units, liquid crystal panels, liquid crystal TVs, and the like are required to have high luminous efficiency.

US Patent Application Publication No. 2006/0249729

  However, in the white light emitting LED light source described in Patent Document 1, since a part of the blue light from the blue light emitting diode chip is used for the green light emission of the green light emitting phosphor, the amount of blue light used for the light emission is blue. There was a problem that light was reduced and luminous efficiency was lowered.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a white LED light source, a backlight unit, a liquid crystal panel, and a liquid crystal TV with high luminous efficiency.

  According to the present invention, a blue light emitting diode chip that emits blue light and a green red light emitting diode obtained by combining a green phosphor powder and a red phosphor powder with an ultraviolet light emitting diode chip are mounted on a substrate. The present invention has been completed by finding that a white LED light source with high luminous efficiency can be obtained.

  The white LED light source according to the present invention solves the above-described problems, and includes a blue light emitting diode chip that emits blue light, an ultraviolet light emitting diode chip that emits ultraviolet light, and a green light that receives the ultraviolet light. A green phosphor powder that receives the ultraviolet light and a red phosphor powder that receives the ultraviolet light and emits red light is dispersed in a cured transparent resin to cover the ultraviolet light emitting diode chip; And a green-red light emitting diode including the semiconductor device is mounted on the substrate.

  The backlight unit according to the present invention solves the above-described problems, and is characterized by using the white LED light source.

  Furthermore, the liquid crystal panel according to the present invention solves the above-described problems and is characterized by using the white LED light source.

  The liquid crystal TV according to the present invention solves the above-described problems, and is characterized by using the white LED light source.

  According to the white LED light source and the backlight unit according to the present invention, a white LED light source and a backlight unit that emit white light with high luminous efficiency can be obtained.

  In addition, according to the liquid crystal panel and the liquid crystal TV according to the present invention, a liquid crystal panel and a liquid crystal TV with high luminous efficiency can be obtained.

The typical sectional view of the white LED light source concerning the present invention.

  A white LED light source, a backlight unit, a liquid crystal panel and a liquid crystal TV according to the present invention will be described with reference to the drawings.

[White LED light source]
FIG. 1 is a schematic cross-sectional view of a white LED light source according to the present invention. As shown in FIG. 1, the white LED light source 1 includes a substrate 40 in which a recess 45 is formed, a blue light-emitting diode chip 20 </ b> B that is separately mounted in the recess 45 of the substrate 40, and a green-red light-emitting diode 10 GR. .

  In the white LED light source 1, one blue light emitting diode chip 20 </ b> B and one green red light emitting diode 10 </ b> GR are mounted on one substrate 40.

(substrate)
The substrate 40 is formed with a recess 45 for mounting the blue light emitting diode chip 20B and the green red light emitting diode 10GR.

  As the substrate 40, for example, ceramics such as alumina and aluminum nitride (AlN), glass epoxy resin, and the like are used. It is preferable that the substrate 40 is an alumina plate or an aluminum nitride plate because the thermal conductivity is high and the temperature rise of the white LED light source can be suppressed.

  Although not shown, the recesses 45 of the substrate 40 are formed with electrodes for mounting the blue light emitting diode chip 20B and the green red light emitting diode 10GR. As the electrode, for example, a metal electrode made of Ag, Pt, Ru, Pd, Al, or the like is used.

(Blue light emitting diode chip)
The blue light emitting diode chip 20B is a light emitting diode chip that emits blue light having a peak wavelength of 400 nm to 500 nm as primary light. As the blue light emitting diode chip 20B, a known blue light emitting diode chip can be used. For example, a GaN-based light emitting diode chip is used.

  The blue light emitting diode chip 20B is bonded to an electrode (not shown) of the substrate by, for example, AuSn eutectic solder or other various solders, silver paste or the like.

(Green red light emitting diode)
The green-red light emitting diode 10GR includes an ultraviolet light-emitting diode chip 20UV, a green-red phosphor layer 30GR in which a green phosphor powder and a red phosphor powder are dispersed in a transparent resin cured material and covers the ultraviolet light-emitting diode chip 20UV, including.

  In the green-red light emitting diode 10GR, the ultraviolet light emitted from the ultraviolet light-emitting diode chip 20UV is received by the green phosphor powder and the red phosphor powder in the green-red phosphor layer 30GR, and the green phosphor powder and the red phosphor powder are received. Emits green light and red light to emit green light and red light to the outside from the surface of the green-red phosphor layer 30GR.

<Ultraviolet light emitting diode chip>
The ultraviolet light emitting diode chip 20UV is a light emitting diode chip that emits ultraviolet light having a peak wavelength of 360 nm to 410 nm as primary light. Here, the ultraviolet light means light including a wavelength in the ultraviolet region, and may be blue-violet light as long as the light includes a wavelength in the ultraviolet region. As the ultraviolet light emitting diode chip 20UV, for example, an InGaN, GaN or AlGaN light emitting diode chip is used.

  The ultraviolet light emitting diode chip 20UV is bonded to an electrode (not shown) of the substrate by, for example, various solders such as AuSn eutectic solder, silver paste, or the like.

<Green red phosphor layer>
The green-red phosphor layer 30GR is formed by dispersing the green phosphor powder and the red phosphor powder in a transparent resin cured product and covering the ultraviolet light-emitting diode chip 20UV.

{Green phosphor powder}
As the green phosphor powder, for example, a green phosphor powder that emits green light having a peak wavelength of 490 nm to 575 nm is used. Examples of the green phosphor powder include a green phosphor powder made of europium manganese activated aluminate having a composition represented by the following formula (1), and an europium manganese activated composition having the composition represented by the following formula (2). A green phosphor powder containing at least one kind of green phosphor powder made of silicate is used.

[Chemical 1]
_{(Ba 1-x-y-} z Sr x Ca y Eu z) (Mg 1-u Mn u) Al 10 O 17 (1)
(Wherein x, y, z, and u satisfy 0 ≦ x <0.2, 0 ≦ y <0.1, 0.005 <z <0.5, and 0.1 <u <0.5. Number.)
It is preferable that z and u in the formula (1) are in the above ranges because the green phosphor powder has high luminous efficiency.

  It is preferable that x and y in the formula (1) are in the above ranges because the green phosphor powder has a good balance between the lifetime and the luminous efficiency.

  If x in the formula (1) is 0.2 or more, the lifetime of the green phosphor powder may be reduced. When x in the formula (1) is 0, the short wavelength component of light from the green phosphor powder increases, and the light emission efficiency may decrease.

[Chemical 2]
_{(Sr 1-x-y-} z-u, Ba x, Mg y, Eu z, Mn u) 2 SiO 4 (2)
(Wherein x, y, z and u are 0.1 ≦ x ≦ 0.35, 0.025 ≦ y ≦ 0.105, 0.025 ≦ z ≦ 0.25, 0.0005 ≦ u ≦ 0. .02 satisfying .02)
The particle size of the green phosphor powder is not particularly limited, but the average particle size is usually 10 μm or more, preferably 10 μm to 100 μm, more preferably 20 μm to 80 μm. Here, the average particle diameter means a value measured by a laser diffraction method.

  It is preferable that the average particle size of the green phosphor powder is 10 μm or more because the light extraction efficiency of the white LED light source 1 is increased.

  If the average particle size of the green phosphor powder is too large, the phosphor particles settle in the phosphor slurry, resulting in a non-uniform slurry, which may increase the variation in optical characteristics. If the average particle size of the green phosphor powder and the red phosphor powder is less than 10 μm, the light extraction efficiency of the white LED light source 1 may be reduced.

Although it does not specifically limit about the manufacturing method of green fluorescent substance, For example, the following methods are mentioned. First, barium carbonate (BaCO ₃ ), strontium carbonate (SrCO ₃ ), manganese carbonate (MnCO ₃ ), magnesium oxide (MgO), europium oxide (Eu ₂ O ₃ ), and silicon dioxide (SiO ₂ ) are represented by the general formula (2). Predetermined amounts are weighed so as to achieve the indicated composition, and these are sufficiently mixed with the sintering aid together with the powder. This raw material mixture is put into a refractory material such as a crucible and fired at a temperature of 1100 to 1300 ° C. for about 2 to 5 hours. Thereafter, the fired product obtained is washed with pure water to remove unnecessary soluble components. Then, after passing through a pulverization step, filtration and drying are performed to obtain a target green phosphor.

{Red phosphor powder}
As the red phosphor powder, for example, a red phosphor powder that emits red light having a peak wavelength of 620 nm to 780 nm is used. Examples of the red phosphor powder include a red phosphor powder composed of europium-activated lanthanum oxysulfide having a composition represented by the following formula (3), and europium-activated CaSiAlN ₃ having a composition represented by the following formula (4). A red phosphor powder containing at least one kind of red phosphor powder made of is used.

[Chemical formula 3]
_{(La 1-x-y Eu} x M y) 2 O 2 S (3)
(Wherein, M is at least one element selected from Sb, Sm, Ga and Sn, and x and y are numbers satisfying 0.01 <x <0.15 and 0 ≦ y <0.03. .)
It is preferable that M in Formula (3) is at least one element selected from Sb, Sm, Ga, and Sn because the luminous efficiency of the red phosphor powder is high.

[Chemical formula 4]
(Sr _x Ca _1-x ) SiAlN ₃ : Eu (4)
(Wherein x is a number satisfying 0 ≦ x <0.4).

  It is preferable that x in the formula (4) is in the above range because the wavelength range of light from the red phosphor powder is appropriate, the emission efficiency is high, and the balance between the wavelength range and emission efficiency is good. As x in the formula (4) increases within the above range, the light from the red phosphor powder tends to have a shorter wavelength, and as it decreases within the above range, the luminous efficiency of the red phosphor powder tends to increase.

  The particle size of the red phosphor powder is not particularly limited, but can be, for example, in the same range as the average particle size of the green phosphor powder. The reason why the average particle diameter of the red phosphor powder is in the same range as the average particle diameter of the green phosphor powder is the same as that of the green phosphor powder, and thus the description thereof is omitted.

  The red phosphor powder is obtained by adjusting the mixing ratio of raw materials, adjusting the firing temperature and firing time, or performing a cleaning process in a known production method, in the same manner as the production method of the green phosphor powder. .

{Transparent resin cured product}
The transparent resin cured product is obtained by curing a transparent resin, that is, a highly transparent resin. As the transparent resin, for example, a silicone resin or an epoxy resin is used. Among silicone resins, dimethyl silicone resin is preferable because of its high UV resistance.

  The green-red phosphor layer 30GR includes, for example, a green phosphor slurry in which a transparent resin and a green phosphor powder or a red phosphor powder are first mixed, and the green phosphor powder or the red phosphor powder is dispersed in the transparent resin. A red phosphor slurry is prepared, and then a green phosphor slurry and a red phosphor slurry are mixed to prepare a mixed phosphor slurry, and this mixed phosphor slurry is applied to the ultraviolet light emitting diode chip 20UV and cured. can get. The mixing ratio of the phosphor slurries of each color during the preparation of the mixed phosphor slurry is adjusted so as to obtain a desired secondary light emission color.

  The mixed phosphor slurry can be cured, for example, by heating to 100 ° C to 160 ° C.

{Action}
Next, the operation of the white LED light source 1 will be described.

  The blue light emitting diode chip 20B emits blue light having a peak wavelength of 400 nm to 500 nm when energized.

  In the green red light emitting diode 10GR, the ultraviolet light emitting diode chip 20UV emits ultraviolet light having a peak wavelength of 360 nm to 410 nm as primary light when energized. This ultraviolet light is received by the green phosphor powder and the red phosphor powder in the green-red phosphor layer 30GR, and the green phosphor powder and the red phosphor powder emit green light and red light as secondary light, Light and red light are emitted from the surface of the green-red phosphor layer 30GR.

  In the white LED light source 1, the green light is red so that the total light color of the blue light emitted from the blue light emitting diode chip 20B and the green light and red light emitted from the green red light emitting diode 10GR is white. The amount of green phosphor powder and red phosphor powder in phosphor layer 30GR and the current values of blue light emitting diode chip 20B and ultraviolet light emitting diode chip 20UV are determined. For this reason, the white LED light source 1 emits white light from the light emitting surface. White light emitted from the light emitting surface is usually in the range of 0.19 ≦ x and y ≦ 0.38 in the XYZ color system.

  In the white LED light source 1, the blue light emitting powder is not used to obtain blue light, but the blue light emitting diode chip 20B emits blue light, so that the luminous efficiency of white light emitted from the white LED light source 1 is increased.

  The reason why the luminous efficiency of the white light emitted from the white LED light source 1 is high is as follows. That is, in a white LED light source that obtains white light using a blue phosphor powder, a green phosphor powder, and a red phosphor powder, in general, a phosphor powder that emits light in a long wavelength region is a short wavelength region. It is easy to absorb the emitted light of the phosphor powder that emits the light. Specifically, the red phosphor powder absorbs blue light and green light, and the green phosphor powder easily absorbs blue light.

  For this reason, a conventional white LED light source, for example, one ultraviolet light emitting diode chip is mounted on a substrate, and the blue light emitting powder, green phosphor powder and red phosphor powder are made into a transparent resin cured product. When using a three-color mixed type white LED light source sealed with a dispersed phosphor layer, blue light and green light are absorbed by the red phosphor powder and green phosphor powder in the phosphor layer, resulting in luminous efficiency There was a drop in

  On the other hand, in the white LED light source 1 according to the present invention, the blue light emitting diode chip 20B that emits blue light and the green and red light emitting diode 10GR that emits green light and red light are separately mounted on the substrate 40.

  Thereby, since the white LED light source 1 does not absorb the blue light having a large influence on the light emission efficiency by the green phosphor powder or the red phosphor powder in the phosphor layer, the light emission efficiency is hardly lowered and the light emission efficiency is high.

  According to the white LED light source 1, a white LED light source with high luminous efficiency can be obtained.

  In the white LED light source 1, an example is shown in which one blue light emitting diode chip 20B and one green red light emitting diode 10GR are mounted on the substrate 40. However, the white LED light source according to the present invention is a blue light emitting diode chip. Other light emitting elements may be mounted on the substrate 40 in addition to 20B and the green-red light emitting diode 10GR. For example, in addition to the blue light-emitting diode chip 20B and the green-red light-emitting diode 10GR, other configurations of a blue light-emitting diode, a green light-emitting diode, a red light-emitting diode, and a yellow light-emitting diode may be mounted.

  Moreover, in the white LED light source 1, the example which consists of the green light emitting diode chip | tip 20UV and the green red phosphor layer 30GR which coat | covers this ultraviolet light emitting diode chip | tip 20UV was shown as the green red light emitting diode 10GR. However, the green red light emitting diode 10GR of the white LED light source according to the present invention may be provided with a transparent resin material layer made of a transparent resin cured material between the ultraviolet light emitting diode chip 20UV and the green red phosphor layer 30GR. When the transparent resin layer is provided, visible light (secondary light) such as green light and red light emitted from each phosphor powder dispersed in the green-red phosphor layer 30GR is emitted from the light emitting surface of the white LED light source 1. Decreasing the light emission efficiency by entering the ultraviolet light emitting diode chip 20UV on the opposite side is suppressed, and the light emission efficiency is increased.

  The backlight unit according to the present invention uses the white LED light source according to the present invention as a light source for a liquid crystal panel, for example.

  The backlight unit according to the present invention includes, for example, a light source unit produced by arranging a plurality of the white LED light sources in a straight line, and receives substantially strip-shaped light emitted from the light source unit from the side and from the front. And a light guide plate that emits light.

  According to the backlight unit according to the present invention, since the white LED light source with high luminous efficiency according to the present invention is used as the light source, a backlight unit with high luminous efficiency can be obtained.

  The liquid crystal panel according to the present invention uses the white LED light source according to the present invention as a light source.

  The liquid crystal panel according to the present invention incorporates, for example, the backlight unit according to the present invention.

  According to the liquid crystal panel according to the present invention, since the white LED light source with high luminous efficiency according to the present invention is used as a light source, a liquid crystal panel with high luminous efficiency can be obtained.

  The liquid crystal TV according to the present invention uses the white LED light source according to the present invention as a light source.

  The liquid crystal TV according to the present invention incorporates, for example, the liquid crystal panel according to the present invention.

  According to the liquid crystal TV according to the present invention, since the white LED light source with high luminous efficiency according to the present invention is used as a light source, a liquid crystal TV with high luminous efficiency can be obtained.

  Examples are shown below, but the present invention is not construed as being limited thereto.

[Example 1]
Eu and Mn activated silicate (Sr _1.48 Ba _0.32 Mg _0.095 Mn _0.005 Eu _0.1 ) SiO ₄ phosphor having an average particle diameter of 20 μm as a green phosphor, and an average as a red phosphor An Eu-activated lanthanum sulfide (La _0.885 Eu _0.115 ) ₂ O ₂ S phosphor having a particle size of 20 μm was prepared. The average particle diameter of the phosphor is a value measured by a laser diffraction method. Hereinafter, the average particle diameter of the phosphor means a value measured by a laser diffraction method.

(Preparation of mixed phosphor slurry)
Each phosphor was mixed in a silicone resin at a ratio of 30% by mass to prepare a slurry. Each of these slurries was mixed at a ratio of 62% by mass of green phosphor slurry and 38% by mass of red phosphor slurry to prepare a mixed phosphor slurry.

(Production of white LED light source)
One blue light emitting diode chip (EZR-30 manufactured by Cree, emission peak wavelength; 455 nm) and one ultraviolet light emitting diode chip (emission peak wavelength: 400 nm, size: 300 × 300 μm) on one alumina substrate. Mounted apart.

  Next, a silicone resin not containing a phosphor was dropped onto the ultraviolet light emitting diode chip on the alumina substrate so that the thickness after curing was 1 mm.

  Further, the mixed phosphor slurry was dropped on the ultraviolet light emitting diode chip on which the silicone resin was dropped.

  Thereafter, the ultraviolet light emitting diode chip to which the mixed phosphor slurry is dropped is heat-treated at 140 ° C. to cure the silicone resin, whereby one blue light emitting diode chip and one green red light emitting diode are formed on one alumina substrate. Thus, a white LED light source was formed.

  The green-red light-emitting diode includes an ultraviolet light-emitting diode chip, a transparent resin cured material layer that covers the ultraviolet light-emitting diode chip, and a green-red phosphor layer that covers the transparent resin cured material layer and emits green light and red light. It was a thing.

  Tables 1 and 2 show the compositions of the light-emitting diode chips used in Example 1 and the phosphors of the respective colors.

  About the obtained white LED light source, the electric current was sent through the light emitting diode chip on the conditions shown in Table 3, and the luminous efficiency was measured.

  The luminous efficiency was calculated by the formula (light flux of emitted light from white LED light source (lm)) / {(current value of white LED light source (A)) · (voltage value of white LED light source (V))}.

Table 3 shows the measurement conditions and results of the luminous efficiency.

[Examples 2 to 8]
A white LED light source was produced in the same manner as in Example 1 except that the phosphors shown in Table 2 were used as the green phosphor and the red phosphor, and the luminous efficiency was measured.

  Table 3 shows the measurement conditions and results of the luminous efficiency.

[Comparative Example 1]
(Phosphor powder)
Eu-activated alkaline earth chlorophosphate (Sr _0.95 Ba _0.043 Eu _0.007 ) ₅ (PO ₄ ) ₃ Cl phosphor having an average particle diameter of 20 μm as a blue phosphor, and an average particle diameter as a green phosphor With 20 μm Eu and Mn activated silicate (Sr _1.48 Ba _0.32 Mg _0.095 Mn _0.005 Eu _0.1 ) SiO ₄ phosphor, and Eu with an average particle size of 20 μm as red phosphor An activated lanthanum sulfide (La _0.885 Eu _0.115 ) ₂ O ₂ S phosphor was prepared.

(Preparation of mixed phosphor slurry)
Each phosphor was mixed in a silicone resin at a ratio of 30% by mass to prepare a slurry. Each of these slurries is 30% by mass of blue phosphor slurry and green so that the emission chromaticity of the white LED lamp falls within the range of (x = 0.29 to 0.34, y = 0.29 to 0.34) The phosphor slurry was mixed at a ratio of 43% by mass and the red phosphor slurry at a ratio of 27% by mass to prepare a mixed phosphor slurry.

(Production of white LED light source)
One ultraviolet light emitting diode chip (emission peak wavelength: 400 nm, size: 300 × 300 μm) was mounted on one alumina substrate.

  Next, a silicone resin not containing a phosphor was dropped onto the ultraviolet light emitting diode chip on the alumina substrate so that the thickness after curing was 1 mm. Further, the mixed slurry was dropped on the ultraviolet light emitting diode chip onto which the silicone resin was dropped.

  Thereafter, the ultraviolet light-emitting diode chip to which the phosphor slurry of each color is dropped is heat-treated at 140 ° C. to cure the silicone resin, so that the ultraviolet light-emitting diode chip, the transparent resin cured material layer covering the ultraviolet light-emitting diode chip, and blue A white LED light source comprising a phosphor layer made of a transparent resin cured product containing a phosphor, a green phosphor and a red phosphor and covering the transparent resin cured product layer was obtained.

  With respect to the obtained white LED light source, luminous efficiency was measured in the same manner as in Example 1.

  Table 3 shows the measurement conditions and results of the luminous efficiency.

1 White LED light source 10B Blue light emitting diode 10GR Green red light emitting diode 20UV Ultraviolet light emitting diode chip 20B Blue light emitting diode chip 30B Blue phosphor layer 30GR Green red phosphor layer 40 Substrate 45 Recess of substrate

Claims (8)

A blue light emitting diode chip that emits blue light; and
An ultraviolet light emitting diode chip that emits ultraviolet light, a green phosphor powder that receives the ultraviolet light and emits green light, and a red phosphor powder that receives the ultraviolet light and emits red light are in the transparent resin cured product. A green-red light-emitting diode comprising a green-red phosphor layer dispersed in and covering the ultraviolet light-emitting diode chip,
A white LED light source characterized in that is mounted on a substrate. The white LED light source according to claim 1, wherein the blue light emitting diode chip emits blue light having a peak wavelength of 400 nm to 500 nm. The white LED light source according to claim 1, wherein the ultraviolet light emitting diode chip emits ultraviolet light having a peak wavelength of 360 nm to 410 nm. The green phosphor powder is composed of a europium manganese activated aluminate having a composition represented by the following formula (2), and a europium manganese activated silicate having a composition represented by the following formula (3): 2. The white LED light source according to claim 1, comprising at least one kind of green phosphor powder.
[Chemical 1]
_{(Ba 1-x-y-} z Sr x Ca y Eu z) (Mg 1-u Mn u) Al 10 O 17 (1)
(Wherein x, y, z, and u satisfy 0 ≦ x <0.2, 0 ≦ y <0.1, 0.005 <z <0.5, and 0.1 <u <0.5. Number.)
[Chemical 2]
_{(Sr 1-x-y-} z-u, Ba x, Mg y, Eu z, Mn u) 2 SiO 4 (2)
(Wherein x, y, z and u are 0.1 ≦ x ≦ 0.35, 0.025 ≦ y ≦ 0.105, 0.025 ≦ z ≦ 0.25, 0.0005 ≦ u ≦ 0. .02 satisfying .02) The red phosphor powder is a red phosphor powder composed of europium-activated lanthanum oxysulfide having a composition represented by the following formula (3), and a composition represented by the following formula (4). 2. The white LED light source according to claim 1, comprising at least one red phosphor powder made of europium-activated CaSiAlN ₃ .
[Chemical formula 3]
_{(La 1-x-y Eu} x M y) 2 O 2 S (3)
(Wherein, M is at least one element selected from Sb, Sm, Ga and Sn, and x and y are numbers satisfying 0.01 <x <0.15 and 0 ≦ y <0.03. .)
[Chemical formula 4]
(Sr _x Ca _1-x ) SiAlN ₃ : Eu (4)
(In the formula, x is a number satisfying 0 ≦ x <0.4.) A backlight unit using the white LED light source according to any one of claims 1 to 5. A liquid crystal panel using the white LED light source according to any one of claims 1 to 5. 6. A liquid crystal TV using the white LED light source according to claim 1.

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