JP2009280763A - Phosphor preparation and light emitting device using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting device causing little reduction in brightness of a white color and little fluctuation in chromaticity and having excellent color reproducibility (an NTSC rate) even if a tetravalent manganese-activated fluorinated tetravalent metal salt phosphor is used. <P>SOLUTION: The phosphor preparation, which includes at least a tetravalent manganese-activated fluorinated tetravalent metal salt red light emitting phosphor substantially represented by MI<SB>2</SB>(MII<SB>1-a</SB>Mn<SB>a</SB>)F<SB>6</SB>in a silicone resin, is prepared with viscosity by which the phosphor does not precipitate in the silicone resin and its dispersion state is maintained. The light emitting device has a light emitting element emitting primary light, and a wavelength conversion part absorbing a part of the primary light emitted from the light emitting element and emitting secondary light with a wavelength longer than that of the primary light. The wavelength conversion part is formed by using the phosphor preparation. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention provides a light emitting device that includes a light emitting element that emits primary light, and a wavelength conversion unit that absorbs part of the primary light emitted from the light emitting element and emits secondary light having a wavelength longer than the wavelength of the primary light. The present invention relates to a device and a phosphor preparation that is particularly suitable for forming the light-emitting device.

  Light-emitting devices that combine semiconductor light-emitting elements and phosphors are attracting attention as next-generation light-emitting devices that are expected to have low power consumption, downsizing, high brightness, and a wide range of color reproducibility, and are actively researched and developed. Has been done. The primary light emitted from the light emitting element is usually in the range of long wavelength ultraviolet to blue, that is, 380 to 480 nm. In addition, wavelength converters using various phosphors suitable for this application have been proposed.

  Furthermore, in recent years, development competition for backlights for small liquid crystal displays (hereinafter referred to as LCD (Liquid Crystal Display)) has intensified. Various methods have been proposed in this field, but no method that satisfies both brightness and color reproducibility (NTSC ratio) has been found.

Currently, as a white light emitting device, a blue light emitting element (peak wavelength: around 450 nm) and (Y, Gd) ₃ (Al, Ga) activated by trivalent cerium that is excited by the blue light and emits yellow light are emitted. ) A combination with ₅ O ₁₂ phosphor or (Sr, Ba, Ca) ₂ SiO ₄ phosphor activated with divalent europium is mainly used. However, in these light emitting devices, color reproducibility (NTSC ratio) is around 65% (CIE 1931). On the other hand, in recent years, a small LCD having better color reproducibility has been demanded.

  Examples of the red light-emitting phosphor that enhances color reproducibility (NTSC ratio) are substantially represented by the following general formula disclosed in, for example, US Patent Application Publication No. 2006/0169998 (Patent Document 1). It is known that a valent manganese-activated fluorinated tetravalent metal salt phosphor is suitable.

General _{formula: MI 2 (MII 1-a} Mn a) F 6
(In the formula, MI represents at least one alkali metal element selected from Li, Na, K, Rb and Cs, and MII represents at least one tetravalent metal element selected from Ge, Sn, Ti and Zr. And a number satisfying 0.001 ≦ a ≦ 0.5.)
However, Patent Document 1 does not describe the color reproducibility (NTSC ratio) in combination with a highly efficient green phosphor.

Further, in the light emitting device using such a red light emitting phosphor for the wavelength conversion unit, when continuous lighting is performed under an environment of high temperature and high humidity (60 ° C., 90% (relative humidity)), There is a technical problem that the brightness is greatly reduced and the white chromaticity varies greatly. From such a background, there is an urgent need to improve the white chromaticity variation in continuous lighting of the tetravalent manganese-activated fluorinated tetravalent metal salt phosphor. However, Patent Document 1 does not mention white chromaticity fluctuation in continuous lighting.
US Patent Application Publication No. 2006/0169998

  The present invention has been made to solve the above-mentioned problems, and the object of the present invention is to reduce white brightness even when a tetravalent manganese-activated fluorinated tetravalent metal salt phosphor is used. The present invention is to provide a light-emitting device that is small in chromaticity variation and excellent in color reproducibility (NTSC ratio).

The phosphor preparation of the present invention contains a silicone resin,
Formula _{(A): MI 2 (MII} 1-a Mn a) F 6
(In the general formula (A), MI represents at least one alkali metal element selected from Li, Na, K, Rb and Cs, and MII represents at least one 4 selected from Ge, Sn, Ti and Zr. A valent metal element, a number satisfying 0.001 ≦ a ≦ 0.5)
At least a tetravalent manganese-activated fluorinated tetravalent metal salt red light emitting phosphor substantially represented by the formula, wherein the phosphor does not settle in the silicone resin and is prepared to have a viscosity that maintains a dispersed state. It is characterized by.

  In the phosphor preparation of the present invention, in the general formula (A), MI is preferably K and MII is preferably Ti.

The phosphor preparation of the present invention preferably has a viscosity of 20000 mPa · s or more.
The present invention also includes a light emitting element that emits primary light, and a wavelength conversion unit that absorbs part of the primary light emitted from the light emitting element and emits secondary light having a wavelength longer than the wavelength of the primary light. There is also provided a light-emitting device, wherein the wavelength conversion unit is formed using the phosphor preparation of the present invention described above.

  In the light emitting device of the present invention, the wavelength conversion unit includes one or more phosphors including a green light emitting phosphor and a red light emitting phosphor, and the red light emitting phosphor is included in the phosphor preparation. The manganese-activated tetravalent metal salt red light emitting phosphor is preferable.

  In the light-emitting device of the present invention, the light-emitting element is preferably a gallium nitride-based semiconductor that emits primary light having a peak wavelength of 430 to 480 nm.

In the light emitting device of the present invention, the green light emitting phosphor is,
Formula _{(B): Eu b Si c} Al d O e N f
(In the above general formula (B), 0.005 ≦ b ≦ 0.4, c + d = 12, e + f = 16)
A divalent europium activated oxynitride phosphor substantially β-type SiAlON represented by:
Formula (C): 2 (Ba _1-gh MIII _g Eu _h ) O.SiO ₂
(In the general formula (C), MIII represents at least one alkaline earth metal element selected from Mg, Ca and Sr, and satisfies 0 <g ≦ 0.55 and 0.03 ≦ h ≦ 0.10. Is the number to do)
It is preferably at least one selected from the group consisting of divalent europium activated silicate phosphors substantially represented by:

  According to the present invention, it is possible to efficiently absorb the light emitted from the light emitting element and obtain white light with high efficiency, and there is little decrease in white brightness, and excellent life characteristics with small chromaticity variation. A highly reliable light-emitting device that has excellent color reproducibility (NTSC ratio) and a phosphor preparation that is particularly suitable for realizing the light-emitting device can be provided.

  The phosphor preparation of the present invention contains at least a tetravalent manganese-activated tetravalent metal salt red light emitting phosphor substantially represented by the following general formula (A) in a silicone resin.

(A) Tetravalent manganese-activated tetravalent metal salt red light emitting phosphor The red light emitting phosphor is:
Formula _{(A): MI 2 (MII} 1-a Mn a) F 6
Is substantially represented by In the general formula (A), Mn represents manganese, and F represents fluorine. In the general formula (A), MI represents at least one alkali metal element selected from Li, Na, K, Rb and Cs. In general formula (A), MII represents at least one tetravalent metal element selected from Ge, Sn, Ti, and Zr. From the viewpoint of brightness and stability of powder characteristics, in the general formula (A), MI is preferably K and MII is preferably Ti.

  In the general formula (A), the value of a indicating the composition ratio (concentration) of Mn is 0.001 ≦ a ≦ 0.5. When the value of a is less than 0.001, there is a problem that sufficient brightness cannot be obtained, and when the value of a exceeds 0.5, the brightness is reduced by concentration quenching or the like. This is because there is a problem of a significant decrease. From the viewpoint of brightness and stability of powder characteristics, the value of a is preferably 0.005 ≦ a ≦ 0.2.

Specific examples of the tetravalent manganese-activated tetravalent metal fluoride red light emitting phosphor include K ₂ (Ti _0.99 Mn _0.01 ) F ₆ , K ₂ (Ti _0.9 Mn _0.1 ) F ₆ , K _2. (Ti _0.999 Mn _0.001 ) F ₆ , Na ₂ (Zr _0.98 Mn _0.02 ) F ₆ , Cs ₂ (Si _0.95 Mn _0.05 ) F ₆ , Na ₂ (Ti _0.98 Mn _0.02 ) F ₆ , Cs ₂ (Sn _0.98 Mn _0.02 ) F ₆ , Cs ₂ (Zr _0.995 Mn _0.005 ) F ₆ , K ₂ (Sn _0.995 Mn _0.005 ) F ₆ , (K _0.80 Cs _0.20 ) ₂ (Zr _0.98 Mn _0.02 ) F ₆ , K ₂ (Ti _0.88 Zr _0.10 Mn _0.02 ) F ₆ , Na ₂ (Ti _0.75 Sn _0.20 Mn _0.05 ) F ₆ , Cs ₂ (Ge _0.999 Mn _0.001 ) F ₆ , (K _0.80 Na _0.20 ) ₂ (Ti _0.69 Ge _0.30 Mn _0.01 ) F ₆ Of course, it is not limited to these.

  In addition, the phosphor preparation of the present invention is prepared to have a viscosity at which the above-described tetravalent manganese-activated fluorinated tetravalent metal salt red light-emitting phosphor does not settle in the silicone resin and maintains a dispersed state. The viscosity of the phosphor preparation of the present invention is not particularly limited as long as fluidity is maintained at 20000 mPa · s or more (for example, about 30000 mPa · s). In addition, the viscosity of this fluorescent substance preparation points out the value measured, for example using Brookfield R / S rheometer CP-50-1.

  In the phosphor preparation of the present invention, a silicone resin and a tetravalent manganese-activated tetravalent metal salt red light emitting phosphor are mixed using a conventionally known appropriate mixing device such as a high-speed rotating device, It can be prepared by dispersing a tetravalent manganese-activated tetravalent metal fluoride red light emitting phosphor in a silicone resin. In addition, it is preferable to use a silicone resin having a viscosity such that the viscosity of the phosphor preparation is 20000 mPa · s or more.

  Here, FIG. 1 is a cross-sectional view schematically showing a light emitting device 1 of a preferred example of the present invention. As shown in FIG. 1, the light emitting device 1 of the present invention absorbs a part of the primary light emitted from the light emitting element 2 that emits primary light and the light emitted from the light emitting element 2, and has a wavelength longer than the wavelength of the primary light. And a wavelength converter 3 that emits secondary light, and the wavelength converter 3 is formed using the phosphor preparation of the present invention described above. FIG. 2 is a graph showing an emission spectrum distribution of a light emitting device as a preferred example of the present invention. In FIG. 2, the vertical axis represents intensity (arbitrary unit) and the horizontal axis represents wavelength (nm). According to the light emitting device of the present invention provided with the wavelength conversion unit formed using the phosphor preparation of the present invention described above, it is possible to efficiently absorb the light emitted from the light emitting element 2 and obtain highly efficient white light. In addition, a highly reliable light-emitting device that has excellent life characteristics with little decrease in white brightness and small chromaticity variation, and that has excellent color reproducibility (NTSC ratio) is realized. .

  In the light emitting device of the present invention, the wavelength conversion unit 3 includes one or more phosphors including the green light emitting phosphor 11 and the red light emitting phosphor 12 as in the example shown in FIG. It is preferable that No. 12 is a tetravalent manganese-activated tetravalent metal salt red light-emitting phosphor contained in the phosphor preparation of the present invention described above. The light emitting device of the present invention is a red light emitting phosphor, which is a tetravalent manganese-activated tetravalent metal salt red light emitting phosphor whose wavelength conversion part is contained in the phosphor preparation of the present invention described above. Of course, it may be realized so as not to include the green light emitting phosphor.

  In this case, the green light-emitting phosphor 11 used in the light-emitting device of the present invention is a divalent europium-activated oxynitride phosphor that is a β-type SiAlON substantially represented by the following general formula (B): In addition, it is preferably at least one selected from the group consisting of divalent europium activated silicate phosphors substantially represented by the following general formula (C).

(B) Divalent europium activated oxynitride phosphor that is β-type SiAlON The divalent europium activated oxynitride phosphor that is β-type SiAlON is:
Formula _{(B): Eu b Si c} Al d O e N f
Is substantially represented by In the general formula (B), Eu represents europium, Si represents silicon, Al represents aluminum, O represents oxygen, and N represents nitrogen. In the general formula (B), the value of b representing the Eu composition ratio (concentration) is 0.005 ≦ b ≦ 0.4. This is because sufficient brightness cannot be obtained when the value of b is less than 0.005, and when the value of b exceeds 0.4, the brightness is greatly reduced due to concentration quenching or the like. It is to do. In view of the stability of the powder characteristics and the homogeneity of the matrix, the value of b in the above formula is preferably 0.01 ≦ b ≦ 0.2. In the general formula (B), c representing the composition ratio (concentration) of Si and d representing the composition ratio (concentration) of Al are numbers satisfying c + d = 12, and the composition ratio (concentration) of O is F representing the composition ratio (concentration) of e and N is a number satisfying e + f = 16.

Specific examples of the β-type SiAlON divalent europium activated oxynitride phosphor include Eu _0.05 Si _11.50 Al _0.50 O _0.05 N _15.95 , Eu _0.10 Si _11.00 Al _1.00 O _0.10 N _15.90 , Eu _0.30 Si _9.80 Al _2.20 O _0.30 N _15.70 , Eu _0.15 Si _10.00 Al _2.00 O _0.20 N _15.80 , Eu _0.01 Si _11.60 Al _0.40 O _0.01 N _15.99 , Eu _0.005 Si _11.70 Al _0.30 O _0.03 N _15.97 Of course, it is not limited to these.

(C) Divalent europium activated silicate phosphor The divalent europium activated silicate phosphor is:
Formula (C): 2 (Ba _1-gh MIII _g Eu _h ) O.SiO ₂
Is substantially represented by In the general formula (C), Ba represents barium, Eu represents europium, O represents oxygen, and Si represents silicon. In general formula (C), MIII is an alkaline earth metal element and represents at least one element selected from Mg, Ca, and Sr. Among them, MIII is preferably Sr in order to obtain a highly efficient matrix. In the general formula (C), the value of g representing the composition ratio (concentration) of MIII is 0 <g ≦ 0.55, and the value of g is within this range, so that the green type in the range of 510 to 540 nm. Luminescence can be obtained. When the value of g exceeds 0.55, greenish light emission with yellowishness is caused, and the color purity is deteriorated. Furthermore, from the viewpoint of efficiency and color purity, the value of g is preferably in the range of 0.15 ≦ g ≦ 0.45. In the general formula (C), the value of h indicating the composition ratio (concentration) of Eu is 0.03 ≦ h ≦ 0.10. This is because sufficient brightness cannot be obtained when the value of h is less than 0.03, and when the value of h exceeds 0.10, the brightness increases due to concentration quenching or the like. It is because it falls. Note that the value of h is preferably in the range of 0.04 ≦ h ≦ 0.08 from the standpoints of brightness and powder property stability.

As the divalent europium activated silicate phosphor, specifically, 2 (Ba _0.70 Sr _0.26 Eu _0.04 ) · SiO ₂ , 2 (Ba _0.57 Sr _0.38 Eu _0.05 ) O · SiO ₂ , 2 ( Ba _0.53 Sr _0.43 Eu _0.04 ) O · SiO ₂ , 2 (Ba _0.82 Sr _0.15 Eu _0.03 ) O · SiO ₂ , 2 (Ba _0.46 Sr _0.49 Eu _0.05 ) O · SiO ₂ , 2 (Ba _0.59 Sr _0.35 Eu _0.06 ) O・ SiO ₂ , 2 (Ba _0.52 Sr _0.40 Eu _0.08 ) O · SiO ₂ , 2 (Ba _0.85 Sr _0.10 Eu _0.05 ) O · SiO ₂ , 2 (Ba _0.47 Sr _0.50 Eu _0.03 ) O · SiO ₂ , 2 (Ba _0.54 Sr _0.36 Eu _0.10 ) O.SiO ₂ , 2 (Ba _0.69 Sr _0.25 Ca _0.02 Eu _0.04 ) O.SiO ₂ , 2 (Ba _0.56 Sr _0.38 Mg _0.01 Eu _0.05 ) O.SiO ₂ , 2 (Ba _0.81 Sr _0.13 Mg _0.01 and _{Ca 0.01 Eu 0.04) O · SiO} 2 It can gel, but the invention is of course limited thereto.

  The light-emitting element used in the above-described light-emitting device of the present invention is not particularly limited, but gallium nitride (GaN) that emits primary light in a blue region having a peak wavelength of 430 to 480 nm (more preferably 440 to 480 nm). Based semiconductors can be suitably used as light-emitting elements. This is because when a light-emitting element having a peak wavelength of less than 430 nm is used, the contribution of the blue light component is reduced, the color rendering properties are deteriorated, and it may become impractical, and the light emission having a peak wavelength exceeding 480 nm. This is because when the element is used, the brightness in white is lowered, which may be impractical.

As long as the light emitting device of the present invention has the above-described features, other configurations are not particularly limited. In the example shown in FIG. 1, the light emitting element 2 is mounted in the depression of the package 4 having a concave depression, and an electrode pad portion (not shown) of the light emitting element 2 is a lead (power supply) formed on the package 4. Terminal) 5 is electrically connected via a metal wire, and the above-described depression together with the light-emitting element 2 is a tetravalent manganese-activated tetravalent metal fluoride tetravalent metal salt red light-emitting phosphor in the phosphor preparation of the present invention. The wavelength conversion part 3 is formed by sealing with a phosphor containing a phosphor and a sealing agent 13. As the sealant 13, an epoxy resin, a silicone resin, a urea resin, or the like, which is a light-transmitting resin material, can be used, but is not limited thereto. In addition to the phosphor and the sealing agent described above, the wavelength conversion unit 3 may have any appropriate SiO ₂ , TiO ₂ , ZrO ₂ , Al ₂ O ₃ , Y ₂ O _{3 as long as} the effects of the present invention are not impaired. Of course, additives such as may be contained.

  Note that the above-described red light-emitting phosphor used in the phosphor preparation of the present invention and the above-described green light-emitting phosphor used in the light-emitting device are both known and manufactured by a conventionally known appropriate method. Or can be obtained as a product.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated in detail, this invention is not limited to these.

<Example 1>
_{K 2 (Ti 0.99 Mn 0.01)} F 6 ( median diameter: 2.0 .mu.m) becomes red light emitting phosphor 5.00g and viscosity 13500mPa · s silicone resin represented by the composition (A agent (main agent)) 3.33 g Were mixed using a high-speed rotating device to obtain a phosphor preparation (the viscosity of the phosphor preparation obtained by mixing (measured using a Brookfield R / S rheometer CP-50-1)) It was 20000 mPa · s or more.) This phosphor preparation was left in the atmosphere for one week.

  To 4.33 g of the phosphor preparation described above, 0.27 g of the silicone resin (A agent (main agent)) having a viscosity of 13500 mPa · s, and 2.00 g of a silicone resin (B agent (curing agent)) having a viscosity of 35 mPa · s, A light-emitting device having the same configuration as that of FIG. 1 was produced except that a wavelength conversion part was formed using this mixture, and the wavelength conversion part did not contain a green light-emitting phosphor. As the light emitting element, a gallium nitride (GaN) semiconductor having a peak wavelength at 450 nm was used.

<Comparative Example 1>
A silicone resin (A) having a viscosity of 13500 mPa · s was added to 2.60 g of a red light-emitting phosphor represented by a composition of K ₂ (Ti _0.99 Mn _0.01 ) F ₆ (median diameter: 2.0 μm) left in the atmosphere for one week. Wavelength in the same manner as in Example 1 except that 2.00 g of an agent (main agent) and 2.00 g of a silicone resin (B agent (curing agent)) having a viscosity of 35 mPa · s were mixed with a high-speed rotating device. A conversion part was formed to produce a light emitting device.

  The light emitting devices manufactured in Example 1 and Comparative Example 1 were lit at a forward current (IF) of 20 mA, the light output (photocurrent) from the light emitting device was measured, and the brightness (initial value) was evaluated. Moreover, it is lit for 500 hours at a forward current of 30 mA in a constant temperature bath at 60 ° C. and a relative humidity of 90%, and then lit at a forward current of 20 mA at room temperature, and the light output (photocurrent) from the light emitting device is measured. The brightness (after 500 hours) was evaluated. The results are shown in Table 1.

  From Table 1, it can be seen that the light emitting device of the present invention has very excellent life characteristics (reliability) (decrease in luminous intensity) as compared with the conventional product.

<Examples 2-6, Comparative Examples 2-6>
Except for combining the viscosity of the light emitting device, the phosphor, the silicone resin (agent A (main agent), agent B (curing agent)) and the ratio of the red light emitting phosphor to agent A, as shown in Table 2, respectively. 1 and the light emitting device were produced in the same manner as Comparative Example 1, respectively. In addition, all the phosphor preparations used in Examples 2 to 6 had a viscosity of 20000 mPa · s or more.

  Table 3 shows the results of evaluating the brightness (initial value) and brightness (after 500 hours) of the light emitting devices of Examples 2 to 6 and Comparative Examples 2 to 6 in the same manner as in Example 1 and Comparative Example 1.

  From Table 3, it can be seen that the light emitting device of the present invention is very excellent in life characteristics (reliability) (decrease in luminous intensity) as compared with the conventional product.

<Example 7>
_{K 2 (Ti 0.99 Mn 0.01)} F 6 ( median diameter: 2.0 .mu.m) becomes red light emitting phosphor 5.00g and viscosity 13500mPa · s silicone resin represented by the composition (A agent (main agent)) 3.33 g Were mixed using a high-speed rotating device to obtain a phosphor preparation (the viscosity of the phosphor preparation obtained by mixing was 20000 mPa · s or more). This phosphor preparation was left in the atmosphere for one week.

0.840 g of the phosphor preparation described above, 1.58 g of silicone resin (A agent (main agent)) with a viscosity of 13500 mPa · s, 2.00 g of silicone resin (B agent (curing agent)) with a viscosity of 35 mPa · s, Eu _0.05 Si _11.50 Al _0.50 O _0.05 N _15.95 (β-type SiAlON) (median diameter: 12.0 μm) is mixed with 0.180 g of a green light-emitting phosphor, and a wavelength conversion unit using this mixture The light emitting device shown in FIG. 1 was manufactured. As the light emitting element, a gallium nitride (GaN) semiconductor having a peak wavelength at 450 nm was used.

<Comparative Example 7>
A red resin phosphor 0.420 g represented by a composition of K ₂ (Ti _0.99 Mn _0.01 ) F ₆ (median diameter: 2.0 μm) left in the atmosphere for one week was added to a silicone resin (A 2.00 g, viscosity of 35 mPa · s silicone resin (B agent (curing agent)) 2.00 g and Eu _0.05 Si _11.50 Al _0.50 O _0.05 N _15.95 (β-type SiAlON) (median diameter: 12.0 μm The wavelength conversion part was formed in the same manner as in Example 7 except that 0.180 g of a green light-emitting phosphor represented by the composition represented by the above composition was mixed with a high-speed rotating device to form a light-emitting device.

  For the light emitting devices manufactured in Example 7 and Comparative Example 7, the brightness (initial value) and the brightness (after 500 hours) were evaluated in the same manner as in Example 1 and Comparative Example 1. Furthermore, white light from the light emitting device was measured with MCPD-2000 manufactured by Otsuka Electronics, and the value of chromaticity (x, y) was determined. The results are shown in Table 4.

  From Table 4, it can be seen that the light emitting device of the present invention has very excellent life characteristics (reliability) (decrease in luminous intensity) as compared with the conventional product.

<Examples 8 to 11 and Comparative Examples 8 to 11>
Except for combining the viscosity of the light emitting device, the phosphor, the silicone resin (A agent (main agent), B agent (curing agent)) and the ratio of the red light emitting phosphor to the A agent as shown in Table 5, respectively. 7 and the light emitting device were fabricated in the same manner as Comparative Example 7. In addition, all the phosphor preparations used in Examples 8 to 11 had a viscosity of 20000 mPa · s or more.

  Table 6 shows the results of evaluating the brightness (initial value), brightness (after 500 hours), and chromaticity of the light emitting devices of Examples 8 to 11 and Comparative Examples 8 to 11 as in Example 7 and Comparative Example 7. Shown in

  From Table 6, it can be seen that the light emitting device of the present invention has very excellent life characteristics (reliability) (decrease in luminous intensity) as compared with the conventional product.

  Moreover, the color reproducibility (NTSC ratio) of the light-emitting devices of Examples 7 to 11 is 88.3, 88.1, 88.5, 87.9, 88.0, and the color reproducibility (NTSC ratio) is remarkably high. It turns out that it is favorable.

  Here, FIG. 3 shows a light source of a typical edge light type liquid crystal display in which the light emitting devices of Examples 7 to 11 are configured by the side light emitting type package 21 and light from the light source is introduced from the side surface of the light guide plate 22. This is an example of using one or more. In the side light emitting package 21, a light emitting element 24 is mounted in a resin package 23 that also serves as a reflector, and the phosphor-containing sealing resin 25 that covers the periphery of the light emitting element 24 has the contents described in Examples 7-11. Is. Further, a reflection sheet 26 is disposed on the back surface of the light guide plate 22, and an optical sheet 28 such as a diffusion sheet 27, a brightness enhancement sheet, and a color filter is disposed on the surface of the light guide plate 22. Is arranged. In FIG. 3, description of a mounting substrate of the light emitting device is omitted. In addition, the light emitting device is not a side light emitting package, but a light emitting element is mounted on a flat substrate, and the light emitting element is simply formed by covering the periphery with a sealing resin. A plurality of light emitting devices are arranged directly under the liquid crystal panel. It is good also as a structure which does.

It is sectional drawing which shows typically the light-emitting device 1 of a preferable example of this invention. It is a graph which shows the emission spectrum distribution of the light-emitting device of this invention. It is a figure which shows typically the liquid crystal display of the edge light system which uses the light-emitting device of this invention as a light source.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Light emitting device, 2 Light emitting element, 3 Wavelength conversion part, 4 Package, 5 lead | read | reed, 11 Green light emission fluorescent substance, 12 Red light emission fluorescent substance, 13 Sealant, 21 Side light emission type package, 22 Light guide plate, 23 Reflector 24 light emitting element, 25 phosphor-containing sealing resin, 26 reflection sheet, 27 diffusion sheet, 28 optical sheet, 29 liquid crystal panel.

Claims (7)

In silicone resin,
Formula _{(A): MI 2 (MII} 1-a Mn a) F 6
(In the general formula (A), MI represents at least one alkali metal element selected from Li, Na, K, Rb and Cs, and MII represents at least one 4 selected from Ge, Sn, Ti and Zr. A valent metal element, a number satisfying 0.001 ≦ a ≦ 0.5)
At least a tetravalent manganese-activated fluorinated tetravalent metal salt red light-emitting phosphor substantially represented by the above formula, and the phosphor was adjusted to a viscosity that does not settle in the silicone resin and maintains a dispersed state. , Phosphor preparations.   The phosphor preparation according to claim 1, wherein MI is K and MII is Ti in the general formula (A).   The phosphor preparation according to claim 1 or 2, having a viscosity of 20000 mPa · s or more.   A light-emitting device comprising: a light-emitting element that emits primary light; and a wavelength conversion unit that absorbs part of the primary light emitted from the light-emitting element and emits secondary light having a wavelength longer than the wavelength of the primary light. A light-emitting device in which the wavelength conversion unit is formed using the phosphor preparation according to any one of claims 1 to 3.   The wavelength converter includes one or more phosphors including a green light-emitting phosphor and a red light-emitting phosphor, and the red light-emitting phosphor is a tetravalent manganese-activated fluoride 4 included in the phosphor preparation. The light emitting device according to claim 4, wherein the light emitting device is a valent metal salt red light emitting phosphor.   The light emitting device according to claim 4, wherein the light emitting element is a gallium nitride based semiconductor that emits primary light having a peak wavelength of 430 to 480 nm. The green light-emitting phosphor is
Formula _{(B): Eu b Si c} Al d O e N f
(In the above general formula (B), 0.005 ≦ b ≦ 0.4, c + d = 12, e + f = 16)
A divalent europium activated oxynitride phosphor substantially β-type SiAlON represented by:
Formula (C): 2 (Ba _1-gh MIII _g Eu _h ) O.SiO ₂
(In the general formula (C), MIII represents at least one alkaline earth metal element selected from Mg, Ca and Sr, and satisfies 0 <g ≦ 0.55 and 0.03 ≦ h ≦ 0.10. Is the number to do)
The light emitting device according to claim 4, which is at least one selected from the group consisting of divalent europium activated silicate phosphors substantially represented by:

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