JP5732038B2 - White LED for backlight of full-color liquid crystal display device, backlight for full-color liquid crystal display device, and full-color liquid crystal display device - Google Patents

Description

  The embodiment of the present invention is an ITU-R BT. White LED suitable for backlight of full-color liquid crystal display device corresponding to 709 standard, backlight using this white LED, and ITU-R BT. The present invention relates to a full-color liquid crystal display device corresponding to the 709 standard.

  Conventionally, full-color liquid crystal display devices have been widely used as display devices for televisions, PCs, etc. in general homes. On the other hand, with regard to master monitors for broadcast stations and monitors used in video production sites, CRTs (CRTs) have been used so far because of high quality image quality in terms of gradation expression, contrast ratio, animation expression, etc. : Cathode ray tube) displays have been used.

  However, with the rise of thin panel displays in recent years, the production of CRT itself is about to end. For this reason, in particular, broadcast station personnel and video production sites have been replacing CRTs with full-color liquid crystal display devices. However, full-color liquid crystal display devices have a narrow color reproduction range or are caused by an emission spectrum. There was a problem that color reproducibility was low. Therefore, the appearance of a monitor that has a wide color reproduction range and can sufficiently reproduce the color caused by the emission spectrum is desired.

  In a broadcast color CRT, the shape, movement, and hue of a subject are reproduced on an image receiving screen through the processes of imaging (color camera), transmission, and image receiving. Since there are a plurality of processes as described above, in the broadcast color CRT, the transmission method of the image signal including the hue is standardized. Typical examples of this standard are a standard defined by NTSC (National Television System Committee) and a standard defined by EBU (European Broadcasting Union).

  In the field of broadcasting and the like, the EBU standard corresponding to 72% of the color gamut of NTSC (international standard indicating an ideal color gamut), which is a color gamut that can be displayed on a CRT, has been used as a standard. I came. However, in the era of digital signals, the color gamut of HDTV (High Definition Television Broadcasting) is ITU-R ITU-R BT. The standard color point of the 709 standard was changed to the standard. ITU-R BT. The 709 standard color gamut normally corresponds to 72% of the NTSC color gamut, that is, 100% of the EBU standard color gamut.

  Therefore, in recent years, full-color liquid crystal display devices have been used in fields such as broadcasting. Attempts have been made to obtain an image quality equivalent to that of a CRT display in a full-color liquid crystal display device after designing to conform to the 709 standard. In order to realize this attempt, ITU-R BT. The development of color filters, backlights, and the like that meet the 709 standard and have good color reproducibility has also been promoted.

The Institute of Image Information and Television Engineers, “The Journal of the Institute of Image Information and Television Engineers”, The Institute of Image Information and Television Engineers, 2006, Vol. 60, no. 11, pp. 1749-1754

  In a full-color liquid crystal display device, a color reproducibility range as a display device is determined by a combination of a backlight and a color filter. Up to now, regarding color filters, ITU-R BT. Several products have been developed for the purpose of obtaining color reproducibility conforming to the 709 standard. However, in combination with these color filters, ITU-R BT. There has been a problem that a backlight for a full-color liquid crystal display device that realizes color reproducibility conforming to the 709 standard has not yet been obtained.

  The present invention has been made in order to obtain a full-color liquid crystal display device having a high image quality similar to that of a CRT display. ITU-R BT. White LED for a backlight of a full-color liquid crystal display device that realizes color reproducibility conforming to the 709 standard, a backlight for a full-color liquid crystal display device using the white LED, and an ITU-R BT. An object is to provide a full-color liquid crystal display device corresponding to the 709 standard.

A white LED for backlight of a full-color liquid crystal display device according to an embodiment of the present invention is for solving the above-described problem, and emits primary light having an emission peak in a wavelength region of 360 to 430 nm. At least one light-emitting element selected from a light-emitting diode, a blue-violet light-emitting diode, an ultraviolet light-emitting laser, and a blue-violet light-emitting laser, and blue light having an emission peak in a wavelength region of 430 to 470 nm excited by the primary light Blue phosphor that emits light, green phosphor that emits green light having an emission peak in a wavelength range of 520 to 560 nm when excited by the primary light, and a wavelength region of 580 to 740 nm that is excited by the primary light A phosphor layer including a red phosphor that emits red light having two or more linear emission peaks therein. A white LED for a backlight of a color liquid crystal display device, wherein the blue phosphor is a divalent europium activated halophosphate phosphor, a divalent europium activated aluminate phosphor, a silver activated zinc sulfide The phosphor comprises at least one phosphor selected from a phosphor and a chlorine-activated zinc sulfide phosphor, and the green phosphor comprises europium and manganese-activated alkaline earth magnesium orthosilicate phosphor, and europium-activated sialon fluorescence. The red phosphor is a rare earth oxysulfide phosphor activated by at least one selected from europium and samarium, and each color phosphor in the phosphor layer The content of the body is 1 to 10% by weight of the green phosphor, 40 to 80% by weight of the blue phosphor with respect to the total amount of all the phosphors, And the red phosphor is 10 to 50 wt%, and the content of the phosphor powder contained in the phosphor layer is 30 to 80 wt%, were prepared using the white LED liquid crystal display device When the color reproduction range of the emission color of this liquid crystal display device is represented by the (u ′, v ′) value of the chromaticity diagram of the L ^* u ^* v ^* color system, the emission colors of blue, green and red The chromaticity point of each primary color is ITU-R BT. It is characterized by being within the range of ± 0.02 or less with respect to the chromaticity points of the primary colors 709 of blue, green and red.

  Further, the white LED for backlight of the full-color liquid crystal display device according to the embodiment of the present invention is for solving the above problem, and emits primary light having an emission peak in a wavelength region of 360 to 430 nm. , An ultraviolet light emitting diode, a blue-violet light emitting diode, an ultraviolet light emitting laser, and a blue-violet light emitting laser, a green phosphor that emits green light when excited by the primary light, and the primary light For a backlight of a full-color liquid crystal display device, comprising: a blue phosphor that emits blue light when excited by light; and a phosphor layer that includes a red phosphor that emits red light when excited by the primary light. The green phosphor is a divalent europium and manganese activated silicate phosphor substantially represented by the following general formula 1, And at least one phosphor selected from europium-activated sialon phosphors substantially represented by the following general formula 2 or 3, wherein the blue phosphor is substantially represented by the following general formula 4 Divalent europium activated halophosphate phosphor, divalent europium activated aluminate phosphor substantially represented by the following general formula 5, silver activated zinc sulfide substantially represented by the following general formula 6 The phosphor comprises at least one phosphor selected from a phosphor and a chlorine-activated zinc sulfide phosphor substantially represented by the following general formula 7. The red phosphor is substantially represented by the following general formula 8. A rare earth oxysulfide phosphor activated with at least one selected from europium and samarium, and the content of each color phosphor in the phosphor layer is green relative to the total amount of all phosphors 1-10 layers of phosphor %, A blue phosphor 40 to 80 wt%, and a red phosphor, characterized in that 10 to 50% by weight.

[Chemical 1]
Formula _{1: (Sr 2-x-} y-z-u Ba x Mg y Eu z Mn u) SiO 4
(Wherein x, y, z and u satisfy 0.1 <x <1.0, 0 ≦ y <0.21, 0.05 <z <0.3, 0 ≦ u <0.04. Value)

[Chemical 2]
Formula _{2: (Sr 3-x Eu} x) Si y Al z O v N w
(Where, x, y, z, v and w are numbers satisfying 0 <x ≦ 3, 12 <y <14, 2 <z <3.5, 1 <v <3, 20 <w <22. )

[Chemical formula 3]
General formula 3: (Si, Al) ₆ (O, N) ₈ : Eu _x
(Where x is a number satisfying 0 <x <0.3)

[Chemical formula 4]
General formula 4: (M ² , Eu) ₁₀ (PO ₄ ) ₆ · Cl ₂
(Wherein M ² represents at least one element selected from Mg, Ca, Sr and Ba)

[Chemical formula 5]
Formula 5: a (M ³ , Eu) O · bAl ₂ O ₃
(Wherein M ³ represents at least one element selected from Mg, Ca, Sr, Ba, Zn, Li, Rb and Cs, and a and b are 0 <a, 0 <b, 0.2 ≦ a / b ≦ 1.5 is satisfied)

[Chemical 6]
General formula 6: (Zn _1-x Ag _x ) S
(Wherein x is a number satisfying 0 <x <0.01)

[Chemical 7]
Formula 7: (Zn _1-x Cl _x ) S
(Wherein x is a number satisfying 0 <x <0.01)

[Chemical 8]
Formula 8: _{(La 1-x over y-z Y x Sm y Eu} z) 2 O 2 S
(Wherein x, y and z satisfy 0 ≦ x <0.99, 0 ≦ y <0.03, 0.01 <z <0.15, and 1−x−yz ≦ 0) Value)

  Furthermore, a backlight for a full-color liquid crystal display device according to an embodiment of the present invention is for solving the above problem, and is characterized by using the white LED.

  In addition, a full-color liquid crystal display device according to an embodiment of the present invention is for solving the above-described problem, and is manufactured using the backlight.

Sectional drawing which shows an example of white LED of embodiment of this invention. The figure which shows an example of the emission spectrum of the white light which the white LED10 radiate | emits. The ITU-R BT. Manufactured by incorporating the white LED 10 of the embodiment of the present invention. The figure which shows an example of the color reproduction range of the luminescent color of the full-color liquid crystal display device corresponding to 709 standard.

[White LED]
FIG. 1 is a cross-sectional view showing an example of a white LED according to an embodiment of the present invention.
A white LED 10 shown in FIG. 1 includes a substrate 6, a light emitting diode 1 as a light emitting element disposed on the surface of the substrate 6, wiring 5 that electrically connects the substrate 6 and the light emitting diode 1, and the surface of the substrate 6. The resin frame 4 provided so as to surround the light-emitting diode 1, the reflective layer 3 covering the inner wall surface of the resin frame 4, and the cured product in which the phosphor excited by the light emitted from the light-emitting diode 1 is embedded in the resin And a phosphor layer 2 that fills a recess defined by the substrate 6 and the reflective layer 3 and covers the light emitting diode 1.

  Although the white LED 10 shown in FIG. 1 includes the substrate 6 and the reflective layer 3, in the present invention, the substrate 6 and the reflective layer 3 may not be provided if necessary.

  In the white LED 10, electrical energy supplied from the substrate 6 to the light emitting diode 1 via the wiring 5 is converted into ultraviolet light or purple light by the light emitting diode 1, and this ultraviolet light or purple light is converted into the phosphor in the phosphor layer 2. Is converted into longer wavelength light, and white light as a total of ultraviolet light or violet light and longer wavelength light is emitted to the outside of the LED lamp (white LED) 10. Yes.

  For example, the white LED 10 has characteristics suitable for a light source for a backlight of a full-color liquid crystal display device. The white LED 10 is preferably ITU-R BT. It has characteristics suitable for a light source for a backlight of a full-color liquid crystal display device corresponding to the 709 standard.

(Light emitting element)
In the present invention, the light-emitting element 1 is at least one selected from an ultraviolet light-emitting diode, a blue-violet light-emitting diode, an ultraviolet light-emitting laser, and a blue-violet light-emitting laser that emits primary light having an emission peak in a wavelength region of 360 to 430 nm. A seed light emitting element is used. Here, the primary light means light emitted from the light emitting element. The light emitting laser means a semiconductor laser or a laser diode.
FIG. 1 shows an example in which an ultraviolet light emitting diode that emits ultraviolet light or a blue-violet light emitting diode that emits purple light is used as the light emitting element 1.

  Since the light-emitting element 1 emits primary light having an emission peak in a wavelength range of 360 to 430 nm, when combined with the phosphor in the phosphor layer 2, it has higher luminance and more excellent color reproducibility. A white LED can be produced.

  As an ultraviolet light emitting diode or a blue-violet light emitting diode that emits primary light having an emission peak in a wavelength region of 360 to 430 nm, for example, an InGaN-based, GaN-based, or AlGaN-based diode can be used.

  The white LED 10 shown in FIG. 1 is an example in which a light emitting diode is used as the light emitting element 1, but an ultraviolet light emitting laser or a blue-violet light emitting laser may be used instead of the light emitting diode.

(Phosphor layer)
The phosphor layer 2 is a blue phosphor that emits blue light by being excited by primary light having an emission peak in the wavelength range of 360 to 430 nm emitted from the light emitting element 1, and is green by being excited by the primary light. A green phosphor that emits light, and a red phosphor that emits red light when excited by the primary light.

  The phosphor layer 2 is composed of blue phosphor, green phosphor, or red phosphor alone, or particles granulated from one or more of these phosphors, blue phosphor, green phosphor, and red phosphor. Many are dispersed and fixed in the cured resin so as to include the body.

<Green phosphor>
As the green phosphor, a phosphor that emits green light when excited by primary light having an emission peak in a wavelength region of 360 to 430 nm is used.

  Further, as the green phosphor, a phosphor that is excited by primary light having an emission peak in a wavelength region of 360 to 430 nm and emits green light having an emission peak in a wavelength region of 520 to 560 nm is used. Is preferred.

  Examples of such green phosphors include those composed of at least one phosphor selected from europium and manganese activated alkaline earth magnesium orthosilicate phosphors and europium activated sialon phosphors.

  More specifically, as the green phosphor, for example, a divalent europium and manganese-activated silicate phosphor substantially represented by the following general formula 1, and a substantial phosphor represented by the following general formula 2 or 3 Europium activated sialon phosphors are used.

  The phosphor substantially represented by the general formulas 1 to 3 may be expressed as a green phosphor or a yellow phosphor depending on the numerical values of x, y, z, v, and w in the formula. In the specification, it is generically called a green phosphor.

[Chemical 9]
Formula _{1: (Sr 2-x-} y-z-u Ba x Mg y Eu z Mn u) SiO 4
(Wherein x, y, z and u satisfy 0.1 <x <1.0, 0 ≦ y <0.21, 0.05 <z <0.3, 0 ≦ u <0.04. Value)

In the above general formula 1, when x and u are within the above ranges, the wavelength of the green light emitted from the green phosphor powder is suitable as the green light constituting the white light emitted from the white LED 1 of the embodiment. Have a wavelength.
Moreover, in general formula 1, it is preferable that y is in the above-mentioned range since the Mn is sufficiently dissolved in the green phosphor powder to increase the luminous efficiency.
Furthermore, it is preferable that z in the general formula 1 is in the above range because the luminous efficiency of the green phosphor powder is increased.

[Chemical Formula 10]
Formula _{2: (Sr 3-x Eu} x) Si y Al z O v N w
(Wherein x, y, z, v and w are numbers satisfying 0 <x ≦ 3, 12 <y <14, 2 <z <3.5, 1 <v <3, 20 <w <22. is there)

  In the above general formula 2, when x, y, z, v and w are within the above ranges, the wavelength of the green light emitted from the green phosphor powder constitutes the white light emitted from the white LED 1 of the embodiment. Suitable as green light.

[Chemical 11]
General formula 3: (Si, Al) ₆ (O, N) ₈ : Eu _x
(Where x is a number satisfying 0 <x <0.3)

  In the above general formula 3, when x is in the above range, the wavelength of the green light emitted from the green phosphor powder is suitable as the green light constituting the white light emitted from the white LED 1 of the embodiment.

  As the green phosphor, one of the phosphors substantially represented by the above general formulas 1 to 3 can be used alone, or two or more can be mixed and used. That is, the green phosphor is a divalent europium and manganese activated silicate phosphor substantially represented by the above general formula 1, and a europium activated sialon fluorescence substantially represented by the general formula 2 or 3. It can consist of at least 1 type of green fluorescent substance chosen from a body.

The method for producing the green phosphor is not particularly limited. For example, in the case of the phosphor of the general formula 1, the following method may be 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 shown in general formula 1. A predetermined amount is weighed so as to obtain a composition, and these are mixed together with a sintering aid and sufficiently mixed with 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, the target green phosphor is obtained by filtration and drying.
In addition, as a green fluorescent substance, it is also possible to use the thing by the general manufacturing methods other than the above, or the commercial item of the composition which satisfy | fills General formula 1-3.

<Blue phosphor>
As the blue phosphor, a phosphor that emits blue light when excited by primary light having an emission peak in a wavelength region of 360 to 430 nm is used.

  Further, as the blue phosphor, a phosphor that is excited by primary light having an emission peak in a wavelength region of 360 to 430 nm and emits blue light having an emission peak in a wavelength region of 430 to 470 nm is used. Is preferred.

  Examples of such blue phosphors include divalent europium activated halophosphate phosphors, divalent europium activated aluminate phosphors, silver activated zinc sulfide phosphors, and chlorine activated zinc sulfide phosphors. And at least one phosphor selected from the group.

  More specifically, as the blue phosphor, for example, a divalent europium-activated halophosphate phosphor substantially represented by the following general formula 4, a divalent substantially represented by the following general formula 5 A europium activated aluminate phosphor, a silver activated zinc sulfide phosphor substantially represented by the following general formula 6, and a chlorine activated zinc sulfide phosphor substantially represented by the general formula 7 are used.

[Chemical 12]
General formula 4: (M ² , Eu) ₁₀ (PO ₄ ) ₆ · Cl ₂
(Wherein M ² represents at least one element selected from Mg, Ca, Sr and Ba)

[Chemical 13]
Formula 5: a (M ³ , Eu) O · bAl ₂ O ₃

(Wherein M ³ represents at least one element selected from Mg, Ca, Sr, Ba, Zn, Li, Rb and Cs, and a and b are 0 <a, 0 <b, 0.2 ≦ a / b ≦ 1.5 is satisfied)

  In the above general formula 5, when a and b are within the above range, the wavelength of the blue light emitted from the blue phosphor powder is suitably used as the blue light constituting the white light emitted from the white LED 1 of the embodiment. Become.

[Chemical 14]
General formula 6: (Zn _1-x Ag _x ) S
(Wherein x is a number satisfying 0 <x <0.01)

  In the above general formula 6, when x is in the above range, the wavelength of the blue light emitted from the blue phosphor powder is suitable as the blue light constituting the white light emitted from the white LED 1 of the embodiment.

[Chemical 15]
Formula 7: (Zn _1-x Cl _x ) S
(Wherein x is a number satisfying 0 <x <0.01)

  In the above general formula 7, when x is in the above range, the wavelength of the blue light emitted from the blue phosphor powder is suitable as the blue light constituting the white light emitted from the white LED 1 of the embodiment.

  As the blue phosphor, one of the phosphors substantially represented by the above general formulas 4 to 7 can be used alone, or two or more can be mixed and used. That is, the blue phosphor is a divalent europium activated halophosphate phosphor substantially represented by the above general formula 4, and a divalent europium activated aluminate substantially represented by the general formula 5. From at least one blue phosphor selected from phosphors, silver-activated zinc sulfide phosphors substantially represented by general formula 6, and chlorine-activated zinc sulfide phosphors substantially represented by general formula 7 Can be.

The production method of the blue phosphor is not particularly limited. For example, in the case of the phosphor of the general formula 4, the following method can be mentioned. First, europium oxide (Eu ₂ O ₃ ), strontium chloride (SrCl ₂ ), barium carbonate (BaCO ₃ ), calcium carbonate (CaCO ₃ ), and strontium hydrogen phosphate (SrHPO ₄ ) have the composition shown in general formula 4. Thus, a predetermined amount is weighed, and these are mixed with powder together with the sintering aid. This raw material mixture is put into a refractory material such as a crucible and baked at a temperature of 1000 to 1400 ° 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, the target blue phosphor is obtained by filtration and drying.
In addition, as a blue fluorescent substance, it is also possible to use the thing by the general manufacturing methods other than the above, or the commercial item of the composition which satisfy | fills general formula 4-7.

<Red phosphor>
As the red phosphor, a phosphor that emits red light when excited by primary light having an emission peak in a wavelength region of 360 to 430 nm is used.

  In addition, as a red phosphor, red light having two or more linear emission peaks in a wavelength range of 580 to 740 nm is excited by primary light having an emission peak in a wavelength range of 360 to 430 nm. It is preferable to use a phosphor that emits light.

  Examples of such red phosphors include rare earth oxysulfide phosphors activated with at least one selected from europium and samarium.

  More specifically, as the red phosphor, for example, a rare earth oxysulfide phosphor activated by at least one selected from europium and samarium substantially represented by the following general formula 8 is used.

[Chemical 16]
Formula 8: _{(La 1-x over y-z Y x Sm y Eu} z) 2 O 2 S
(Wherein x, y and z satisfy 0 ≦ x <0.99, 0 ≦ y <0.03, 0.01 <z <0.15, and 1−x−yz ≦ 0) Value)

  In the above general formula 8, when x, y and z are within the above ranges, the wavelength of red light emitted from the red phosphor powder is red light constituting the white light emitted from the white LED 1 of the embodiment. Be preferred.

The method for producing the red phosphor is not particularly limited, and examples thereof include the following method. First, europium oxide (Eu ₂ O ₃ ), samarium oxide (Sm ₂ O ₃ ), yttrium oxide (Y ₂ O ₃ ) and sulfur powder (S) are weighed in a predetermined amount so as to have the composition shown in the general formula 8, These are thoroughly mixed with the sintering aid. This raw material mixture is put in a refractory material such as a crucible and fired at a temperature of 1000 to 1300 ° C. for about 2 to 5 hours. Thereafter, the fired product obtained is washed with pure water and acid to remove unnecessary soluble components. Then, after passing through a pulverization step, the target red phosphor is obtained by filtration and drying.
In addition, as a red fluorescent substance, it is also possible to use the thing by the general manufacturing method other than the above, or the commercial item of the composition satisfying General formula 8.

The green phosphor, blue phosphor and red phosphor are usually in the form of powder.
In addition, it is preferable to use one or more of the above-mentioned green phosphor, blue phosphor and red phosphor since the color rendering properties are enhanced. For example, in the case of a green phosphor, it is preferable to use a combination of two or more phosphors substantially represented by general formulas 1 to 3.

In addition, when the average particle size of the particles composed of a single substance of blue phosphor, green phosphor or red phosphor in the phosphor layer 2 or particles granulated from one or more of these phosphors is large, Since the brightness | luminance of the light radiate | emitted from the body layer 2 becomes high, it is preferable.
Specifically, the average particle diameter of the phosphor is usually 1 μm or more, preferably 10 μm or more. Here, the average particle diameter means D ₅₀ indicating a particle diameter of 50% by weight.

The upper limit of the average particle diameter D ₅₀ is not particularly limited, 90% of the white LED phosphor layer 2 thick or less. When the thickness of the phosphor layer 2 is larger than the thickness of the phosphor layer 2, defects such as detachment of the phosphor particles tend to occur when the phosphor layer 2 is formed by hardening the phosphor particles with a resin.

  As a method of increasing the average particle size of the phosphor, a method of granulating using one color of the same or different type of phosphor powder, a method of mixing three colors of the same or different type of phosphor powder, and the like Is mentioned. In addition, as other methods, a method of enlarging the phosphor powder itself at the time of firing by using a firing aid when firing the phosphor powder, or firing at a high temperature for a long time, and the like can be mentioned.

  The phosphors of the general formulas are preferably selected according to the excitation wavelength, luminance requirement, corrosion resistance, cost, and the like.

  In the present invention, in addition to the blue phosphor, the green phosphor and the red phosphor described above, other fluorescent materials such as a blue phosphor, a green phosphor and a red phosphor other than the above, and a yellow phosphor are added to the phosphor layer 2. It may further include a body.

<Hardened resin>
As the cured resin, a cured product of a resin usually used for white LED production is used. The resin cured product is preferably colorless and transparent and has a predetermined light refractive index.

Specifically, the transmittance of the cured resin is usually 98 to 100%, preferably 99 to 100%. Here, the transmittance means a value obtained by measuring 400 nm monochromatic light using a test piece having a thickness of 2 mm.
Moreover, the photorefractive index of resin cured material is 1.3-1.7 normally, Preferably it is 1.4-1.6.

A light refractive index of less than 1.3 is not preferable because light extraction from the light emitting diode element may deteriorate. On the other hand, if the photorefractive index exceeds 1.7, it tends to change in response to ultraviolet rays used for excitation of the phosphor, which is not preferable.
Further, it is desirable that the cured resin has both transmittance and light refractive index within the above ranges.

  Examples of the cured resin having the above characteristics include cured products of resins such as silicone resins and epoxy resins. Among these, a cured resin of a silicone resin is preferable because it is resistant to discoloration by ultraviolet rays and has durability.

  Although the said resin hardened | cured material changes with kinds of resin, it is obtained by leaving a fluid resin and adding a hardening | curing agent etc. to a fluid resin suitably.

<Blending amount of phosphor>
The phosphor layer 2 is obtained, for example, by adding and mixing the green phosphor, the blue phosphor and the red phosphor to a fluid resin and then curing the resin.

  When the green phosphor, blue phosphor and red phosphor in the phosphor layer 2 are irradiated with ultraviolet or blue-violet light having a wavelength of 360 to 430 nm from the light emitting element 1 such as an ultraviolet light emitting diode, respectively. Efficiently absorbs ultraviolet or blue-violet light and emits each color with high efficiency.

  That is, when irradiated with ultraviolet light or blue-violet light, the green phosphor emits high-brightness green light, the blue phosphor emits high-brightness blue light, and the red phosphor Emits bright red light. As a result, white light emitted from the white LED 10 obtained by additive color mixing of green light, blue light and red light also has high luminance.

  In addition, when white light is obtained by the white LED 10, it is not preferable that there is an excessive luminance difference between each color light of green light, blue light, and red light. For example, when only green light has high brightness and blue light and red light have low brightness, the white light emitted from the white LED 10 becomes greenish white, which is not preferable.

  Thus, in order to obtain white light with high luminance with the white LED 10, it is necessary that each color light of green light (G), blue light (B), and red light (R) has high luminance. For this reason, in the white LED 10, in addition to the use of the specific phosphor, the blending ratio of the phosphor is important.

  Regarding the blending ratio of the green phosphor, the blue phosphor and the red phosphor, the white LED 10 is ITU-R BT. It is set as appropriate so as to have light characteristics that can be adapted to the color gamut of the 709 standard.

  Specifically, the content of each color phosphor is usually 1 to 10% by weight for the green phosphor, 40 to 80% by weight for the blue phosphor, and the above for the total amount of all the phosphors. The red phosphor is 10 to 50% by weight.

  The content of each color phosphor is preferably 2 to 9% by weight for the green phosphor, 45 to 65% by weight for the blue phosphor, and the red fluorescence for the total amount of all phosphors. The body is 26-48% by weight.

  If the mixing ratio of each phosphor in the phosphor layer 2 is not in the above relationship, the white LED 10, the backlight incorporating the white LED 10, and the full-color liquid crystal display device produced using the backlight have a desired white point. Cannot be realized, that is, ITU-R BT. There is a possibility that the optical characteristics that can be adapted to the color gamut of the 709 standard are not provided.

  The phosphor layer 2 is produced, for example, by curing a phosphor-resin mixture obtained by blending a green phosphor, a blue phosphor and a red phosphor with a resin.

  As a preparation method of the phosphor-resin mixture, after mixing each color phosphor powder with a resin, a resin containing the obtained phosphor powder of each color is mixed to prepare a phosphor-resin mixture, A method of preparing a phosphor-resin mixture by mixing phosphor powders of respective colors in advance and then mixing the phosphor powder mixture with a resin.

  Here, the content of the phosphor powder in the phosphor-resin mixture is usually 30 to 80% by weight, preferably 40 to 70% by weight.

When the content of the phosphor powder in the phosphor-resin mixture is less than 30% by weight, the direct light emitted from the light emitting diode 1 is not absorbed by the phosphor of the phosphor layer 2 and passes through the phosphor layer 2. In addition, the viscosity of the slurry decreases and the phosphor particles easily settle in the resin, so that the color variation of the light emitted from the phosphor layer 2 tends to increase.
On the other hand, if the content of the phosphor powder in the phosphor-resin mixture exceeds 80% by weight, the viscosity of the slurry becomes high, and the handling of the slurry tends to be difficult.

  It should be noted that the phosphor layer 2 obtained by curing the resin of the phosphor-resin mixture has substantially no or little weight loss of the resin due to curing, depending on the type of resin. The content of the phosphor powder in the resin mixture is substantially equal to the content of the phosphor powder in the phosphor layer 2.

(White LED emission spectrum)
Since the white LED 10 includes the light-emitting element 1 and the phosphor layer 2 having the above-described configuration, in a full-color liquid crystal display device obtained by combining a backlight incorporating the white LED 10 and a color filter, the liquid crystal display device is an ITU- R BT. In addition to emitting light having a light characteristic that can be adapted to the color gamut of the 709 standard, the white LED 10 alone is also ITU-R BT. It is possible to emit light having optical characteristics that can be adapted to the color gamut of the 709 standard.

  However, in general, the light emitted from the full-color liquid crystal display device transmitting the color filter is more ITU-R BT. Than the light emitted from the white LED 10 alone. The light has a light characteristic that can be adapted to the color gamut of the 709 standard.

  The emission spectrum of the white light emitted from the white LED 10 usually has the following first emission peak group, second emission peak group, third emission peak group, and valley.

  Among these, the first emission peak group, the second emission peak group, and the third emission peak group exist in the wavelength region where the transmittance peak of the liquid crystal color filter of each color of blue, green, and red exists. An emission peak group is shown.

  Specifically, in the emission spectrum of white light emitted from the white LED 10, the first emission peak group is an emission peak group existing in the wavelength region where the transmittance peak of the blue color filter exists, and the second emission light is emitted. The peak group is an emission peak group existing in the wavelength region where the transmittance peak of the green color filter exists, and the third emission peak group is an emission peak existing in the wavelength region where the transmittance peak of the red color filter exists. Is a group.

<First emission peak group>
The first emission peak group is an emission peak group having at least one emission peak in the wavelength region of 430 to 470 nm in the emission spectrum of white light emitted from the white LED 10.

In addition, it is preferable that the first emission peak group has an emission peak in a wavelength region of 430 to 460 nm because blue luminance increases.
Furthermore, it is more preferable that the first emission peak group has only one emission peak in the wavelength region of 430 to 460 nm because the blue luminance increases.

<Second emission peak group>
The second emission peak group is an emission peak group having at least one emission peak in the wavelength region of 520 to 560 nm in the emission spectrum of white light emitted from the white LED 10.

In addition, it is preferable that the second emission peak group has an emission peak in a wavelength region of 520 to 555 nm because green luminance is increased.
Furthermore, it is more preferable that the second emission peak group has only one emission peak in the wavelength region of 520 to 555 nm because the green luminance is increased.
In addition, the full width at half maximum of the emission peak of the second emission peak group is desirably 50 nm or more and 200 nm or less.

<Third emission peak group>
The third emission peak group has at least two emission peaks in a wavelength region of 580 to 740 nm in the emission spectrum of white light emitted from the white LED 10, and at least two of the emission peaks are linear. It is an emission peak group which is an emission peak.
In the present specification, the linear emission peak means an emission peak having a full width at half maximum of 5 nm or less.

  In the third emission peak group, it is preferable that the emission peak having the maximum emission intensity among the linear emission peaks is in the wavelength region of 590 to 710 nm, since the red luminance becomes high.

  Further, the third emission peak group has at least one linear emission peak in the wavelength region of 620 to 630 nm, and has a deep red color when there is at least one linear emission peak in the wavelength region of 700 to 710 nm. Is preferable.

<Tanibe>
A trough is a point which shows the minimum value of the emitted light intensity in the wavelength range which exceeds 470 nm and is less than 520 nm in the emission spectrum of the white light which white LED 10 radiate | emits. A trough exists in the wavelength range of 480-500 nm.

  When each emission peak group appears in the wavelength region in the emission spectrum of white light emitted from the white LED 10, the white LED 10, a backlight incorporating the white LED 10, and a full-color liquid crystal display device manufactured using the backlight are obtained. ITU-R BT. It will be compatible with the color gamut of the 709 standard.

<Light emission intensity of white light emission spectrum of white LED>
The emission spectrum of the white light emitted from the white LED 10 is 520 to 560 nm when the maximum value P1 of the emission intensity of the emission peak in the first emission peak group appearing in the wavelength region of 430 to 470 nm is 1.0. The maximum value P2 of the emission intensity of the emission peak in the second emission peak group appearing in the wavelength region is usually 0.1 ≦ P2 ≦ 1.0, preferably 0.2 ≦ P2 ≦ 0.9.

  The emission spectrum of the white light emitted from the white LED 10 is 580 to 740 nm when the maximum value P1 of the emission intensity of the emission peak in the first emission peak group appearing in the wavelength region of 430 to 470 nm is 1.0. The maximum value P3 of the emission intensity of the emission peak in the third emission peak group appearing in the wavelength region is usually 0.2 ≦ P3 ≦ 3.0, preferably 0.3 ≦ P3 ≦ 2.9.

  The emission spectrum of white light emitted from the white LED 10 is 480 to 500 nm when the maximum value P1 of the emission intensity of the emission peak in the first emission peak group appearing in the wavelength region of 430 to 470 nm is 1.0. The minimum value V1 of the emission intensity of the valleys existing in the wavelength region is usually 0.01 ≦ V1 ≦ 0.6, preferably 0.01 ≦ V1 ≦ 0.4.

The emission spectrum of the white light emitted from the white LED 10 is the emission at 600 nm when the maximum value P1 of the emission intensity of the emission peak in the first emission peak group appearing in the wavelength region of 430 to 470 nm is 1.0. The strength _P600 is usually 50% or less of P3, preferably 30% or less of P3, and more preferably 1 to 30% of P3.

The white LED 10 uses a backlight incorporating the white LED 10 when the maximum intensity P1, P2 and P3 of each light emission peak group, the minimum value V1 of the light emission intensity at the valley, and the light emission intensity P600 at ₆₀₀ nm are not in the above relationship. In the full-color liquid crystal display device manufactured as described above, the color mixture of the color filter transmitted light becomes large, and the color purity tends to be lowered.

  For example, if V1 exceeds the above range, that is, exceeds 0.6, the green component of the green light is likely to be mixed into the blue color filter transmitted light, and the blue component of the blue light is included in the green color filter transmitted light. It becomes easy to mix.

  In addition, it is preferable that V1 is smaller, because mixing of the green component of the green light into the blue color filter transmission light and mixing of the blue component of the blue light into the green color filter transmission light is suppressed, but substantially 0. It is difficult to get below .01. For this reason, the lower limit value of V1 is defined as 0.01.

Further, when the P ₆₀₀ exceeds the above range, that is, more than 50% of P3, color purity green or yellow components of the green light to the red color filter transmitted light is mixed tends to decrease.

  FIG. 2 is a diagram illustrating an example of an emission spectrum of white light emitted from the white LED 10. Here, the white LED 10 shown in FIG. 2 is a white LED manufactured in Example 1 below. FIG. 2 also shows the emission spectrum of the white display state of RDS-15X manufactured by Mitsubishi Electric Corporation, which is a typical CRT conforming to the EBU standard.

  As shown in FIG. 2, the white light emission spectrum of the white LED 10 of Example 1 has a first light emission peak group, a second light emission peak group, a third light emission peak group, and a valley.

In FIG. 2, the first emission peak group consists of one emission peak, and its peak wavelength is 452 nm.
In FIG. 2, the second emission peak group consists of one emission peak, and the peak wavelength is 534 nm.

  In FIG. 2, the third emission peak group has four main linear emission peaks, and the peak wavelengths are 595 nm, 616 nm, 625 nm, and 704 nm, respectively.

  2, the white light emission spectrum of the white LED 10 of Example 1 shows that the relationship between the emission wavelength of the light emission peak and the intensity of each light emission peak is a white display state of a typical CRT that conforms to the EBU standard. It can be seen that the emission spectrum is similar. That is, it can be seen that the emission spectrum of white light of the white LED 10 of Example 1 is the same as the emission spectrum necessary to ensure the color reproducibility of the EBU standard.

(Color gamut of emission color of full-color liquid crystal display device manufactured using white LED)
A backlight can be produced by using the white LED 10 as a light source and combining the white LED 10 with a light guide plate or the like. Further, by combining this backlight and a general color filter such as a blue, green and red color filter for a full-color liquid crystal display device, that is, by incorporating a white LED 10, an ITU-R BT. A full-color liquid crystal display device that emits light having a color reproduction range corresponding to the 709 standard can be manufactured. Hereinafter, ITU-R BT. A full color liquid crystal display device that emits light having a color reproduction range corresponding to the 709 standard is simply referred to as ITU-R BT. It is called a full-color liquid crystal display device corresponding to the 709 standard.

This ITU-R BT. The full-color liquid crystal display device compliant with the 709 standard represents the color reproduction range of the emission color of this liquid crystal display device (u ′, v on the u′v ′ coordinate of the CIE L ^* u ^* v ^* color system chromaticity diagram. ') When expressed in terms of value, the chromaticity point of each of the primary colors of blue, green and red of the emission color is ITU-R BT. It is within the range of ± 0.02 or less with respect to the chromaticity points of 709 blue, green and red primaries.

FIG. 3 shows an ITU-R BT. Manufactured by incorporating the white LED 10 according to the embodiment of the present invention. It is a figure which shows an example of the color reproduction range of the luminescent color of the full-color liquid crystal display device corresponding to 709 standard. FIG. 3 is represented by (u ′, v ′) values in the CIE L ^* u ^* v ^* color system chromaticity diagram. Note that the ITU-R BT. A full-color liquid crystal display device corresponding to the 709 standard uses a white LED manufactured in Example 1 below as the white LED 10. FIG. 3 shows ITU-R BT. The color gamut of 709 and NTSC are also shown.

  As shown in FIG. 3, the ITU-R BT. The color reproduction range of a full-color liquid crystal display device corresponding to the 709 standard, ITU-R BT. The 709 color gamut and the NTSC color gamut fall within a range surrounded by a triangle having the chromaticity points BGR of the primary colors of blue, green, and red, respectively.

  Moreover, from FIG. 3, ITU-R BT. Manufactured by incorporating the white LED 10 of Example 1 was used. Color reproduction range of a full-color liquid crystal display device corresponding to the 709 standard, ITU-R BT. It can be seen that the color gamut 709 is substantially in the same range.

  The ITU-R BT. Manufactured by incorporating the white LED 10 according to the embodiment of the present invention. Even when the white LED 10 of the present invention other than Example 1 is incorporated, the color reproduction gamut of the full-color liquid crystal display device compliant with the 709 standard is the color of each primary color of blue, green, and red as in Example 1. It is within a range surrounded by a triangle having the vertex BGR as a vertex.

ITU-R BT. Manufactured by incorporating the white LED 10 of the embodiment of the present invention. The white chromaticity of the luminescent color of the full-color liquid crystal display device compliant with the 709 standard is slightly different depending on the characteristics of the color filter used, but (u ′, v ′ in the CIE L ^* u ^* v ^* color system chromaticity diagram. ) Value, usually in the range of 0.15 ≦ u ′ ≦ 0.31 and 0.36 ≦ v ′ ≦ 0.49.

Moreover, ITU-R BT. Manufactured by incorporating the white LED 10 of the embodiment of the present invention. The blue chromaticity point of the luminescent color of the full-color liquid crystal display device corresponding to the 709 standard is the (u ′, v ′) value of the CIE L ^* u ^* v ^* color system chromaticity diagram, which is usually 0.15. ≦ u ′ ≦ 0.19 and 0.14 ≦ v ′ ≦ 0.18.

  An ITU-R BT. Manufactured by incorporating the white LED 10 according to the embodiment of the present invention. The u 'value and v' value of the blue chromaticity point of the emission color of the full-color liquid crystal display device corresponding to the 709 standard are respectively ITU-R BT. It is within ± 0.02 or less with respect to the u ′ value and the v ′ value of the blue chromaticity point of 709.

Moreover, ITU-R BT. Manufactured by incorporating the white LED 10 of the embodiment of the present invention. The green chromaticity point of the luminescent color of the full-color liquid crystal display device corresponding to the 709 standard is the (u ′, v ′) value of the CIE L ^* u ^* v ^* color system chromaticity diagram, which is usually 0.10. ≦ u ′ ≦ 0.14 and 0.54 ≦ v ′ ≦ 0.58.

  An ITU-R BT. Manufactured by incorporating the white LED 10 according to the embodiment of the present invention. The u 'value and v' value of the green chromaticity point of the emission color of the full-color liquid crystal display device corresponding to the 709 standard are respectively ITU-R BT. It is within the range of ± 0.02 or less with respect to the u ′ value and the v ′ value of the 709 green chromaticity point.

Moreover, ITU-R BT. Manufactured by incorporating the white LED 10 of the embodiment of the present invention. The chromaticity point of red color of the luminescent color of the full-color liquid crystal display device corresponding to the 709 standard is the (u ′, v ′) value of the CIE L ^* u ^* v ^* color system chromaticity diagram, which is usually 0.43. ≦ u ′ ≦ 0.47 and 0.51 ≦ v ′ ≦ 0.55.

  An ITU-R BT. Manufactured by incorporating the white LED 10 according to the embodiment of the present invention. The u 'value and v' value of the red chromaticity point of the emission color of the full-color liquid crystal display device compliant with the 709 standard are respectively ITU-R BT. It is within the range of ± 0.02 or less with respect to the u ′ value and the v ′ value of the red chromaticity point of 709. Therefore, the ITU-R BT. Manufactured by incorporating the white LED 10 according to the embodiment of the present invention. The color reproduction range of a full-color liquid crystal display device corresponding to the 709 standard is ITU-R BT. The color gamut defined by the 709 standard is substantially the same range.

(Effect of white LED)
According to the white LED 10 shown as the embodiment, since white light has light intensity and a light emission peak exists in an appropriate position at an appropriate size, a blue, green, red color filter for a liquid crystal display device, etc. By combining with a general color filter, ITU-R BT. It is possible to manufacture a full-color liquid crystal display device that realizes color reproducibility in a color gamut having substantially the same position and size as the color gamut defined by the 709 standard.
For this reason, according to the white LED 10, a full-color liquid crystal display device manufactured from a backlight using the white LED 10 has a high image quality equivalent to that of a CRT display.

[Backlight]
The backlight is a backlight for a full color liquid crystal display device using the white LED 10. The backlight can be produced by using the white LED 10 as a white light source and appropriately using a light guide plate or the like.
Moreover, you may produce a backlight using multiple white LED with respect to one backlight as needed.
Further, since the white LED has a high luminance, the backlight can be either a sidelight type backlight or a direct type backlight.

(Effect of backlight)
According to the backlight using the white LED 10 shown as the embodiment, the white LED 10 which is a white light source has a liquid crystal display because the white light has light luminance and the emission peak is present at an appropriate position at an appropriate size. By combining with general color filters such as blue, green and red color filters for devices, ITU-R BT. ITU-R BT., Which realizes color reproducibility in a color gamut having substantially the same position and size as the color gamut defined by the 709 standard. A full-color liquid crystal display device corresponding to the 709 standard can be manufactured.

[Full-color LCD device]
A full-color liquid crystal display device is manufactured using the backlight. Specifically, a full-color liquid crystal display device is produced by combining the above backlight and general color filters such as blue, green and red color filters for liquid crystal display devices. The full-color liquid crystal display device is manufactured by combining a backlight using the white LED 10 as a white light source and a general color filter such as a blue, green, or red color filter for the liquid crystal display device.

A color filter layer constituting a general color filter such as a blue, green, or red color filter for a liquid crystal display device is usually formed of an organic pigment, an inorganic pigment, or the like.
Examples of the organic pigment used for the color filter layer include azo pigments, metal phthalocyanine pigments, metal complex pigments, and the like.

  Examples of inorganic pigments used in the color filter layer include red inorganic pigments such as red pepper and molybdenum red; yellow inorganic pigments such as titanium yellow; green inorganic pigments such as titanium cobalt green and cobalt green; blue such as ultramarine and cobalt blue. Inorganic pigments; purple inorganic pigments such as cobalt violet, and the like.

  By using a common color filter such as blue, green, and red color filters for liquid crystal display devices formed from these pigments and the white LED 10 in combination, the liquid crystal display device is ITU-R BT. It is possible to realize color reproducibility conforming to the 709 standard.

(Effect of full-color liquid crystal display device)
According to the above-described full-color liquid crystal display device using a backlight, the white LED 10 that is a white light source of the backlight has a light emission luminance and a light emission peak in an appropriate position at an appropriate size. By combining with general color filters such as blue, green and red color filters for display devices, ITU-R BT. It becomes possible to realize color reproducibility in a color gamut having substantially the same position and size as the color gamut defined by the 709 standard.

  Further, according to this full-color liquid crystal display device, ITU-R BT. Since it is possible to correspond to the color gamut defined by the 709 standard, it can be used in place of a CRT display for broadcasting, video creation or the like.

  Note that a backlight using the white LED of the present invention and ITU-R BT. Other configurations of the full-color liquid crystal display device corresponding to the 709 standard can be arbitrarily set according to various uses and purposes.

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

(Examples 1-9)
For the evaluation of the white LED, a white LED having a cross section shown in the structure of FIG. 1 was produced. First, an ultraviolet light emitting diode having a size of 300 μm square was used as the light emitting element 1, and the ultraviolet light emitting diode 1 was arranged on the surface of the substrate 6. Next, a blue phosphor powder having an average particle size of 5 μm, a green phosphor powder having an average particle size of 5 μm, and a red phosphor powder having an average particle size of 5 μm are prepared, and the total amount of these phosphor powders is 70 parts by weight, 30 parts by weight of a silicone resin was mixed to obtain a slurry. The average particle diameter of the phosphor powder is D ₅₀ is the particle size of 50% by weight integrated value. Furthermore, this slurry was dropped on the ultraviolet light-emitting diode 1 and heat treated at 100 to 150 ° C. to cure the silicone resin and form white LEDs according to the respective examples. The silicone resin used had a refractive index of 1.4 after curing.

  Table 1 shows the excitation wavelength of the ultraviolet light-emitting diode used in the manufacture of the white LED of each of the above examples, the types of the blue phosphor powder, the green phosphor powder and the red phosphor powder, and the total amount of the phosphor as 100% by weight. The amount (% by weight) of each color phosphor is shown.

(Comparative Examples 1-3)
A white LED similar to that of Example 1 was prepared except that the composition of the phosphor of each color was outside the scope of the present invention as shown in Table 1, and this was used as a white LED according to Comparative Examples 1 and 2.

  Further, as Comparative Example 3, a blue light emitting diode was used as the light emitting element 1, and a white LED having a phosphor layer containing only the green phosphor shown in Table 1 was produced in the same manner as described above.

<Evaluation>
The emission spectrum of the white LED according to each example and comparative example was measured. The results are shown in Table 2 for the wavelength of the emitted luminescence peak and the intensity ratio of each luminescence peak. In addition, the linear peak was distinguished by attaching (l) after the unit of wavelength nm. Further, in the emission peak intensity, P1, P2, P3, V1 , P 600 is the intensity shown below, respectively.
P1: Maximum intensity of the first emission peak group (range of 430 to 470 nm) P2: Maximum intensity of the second emission peak group (range of 520 to 560 nm) P3: Third emission peak group (range of 580 to 740 nm) ) Maximum intensity V1: minimum intensity P _{600 in} the valley (in the range of 480 to 500 nm) between the first emission peak group and the second emission peak group: intensity at a wavelength of 600 nm, and P ₆₀₀ / P3 is 600 nm The percentage (%) with respect to the maximum intensity P3 of the third emission peak group of intensity is shown.

  In the white LED of the example, it can be seen that the emission peak of the emission spectrum is almost the same as the emission spectrum of the CRT shown in FIG. On the other hand, in the white LED of the comparative example, since the blending amount of the phosphor is not adjusted within the range of the present invention, in the comparative example 1, since the maximum intensity of the first emission peak group is large, P3 / The P1 ratio becomes smaller than the lower limit, and in Comparative Example 2, the wavelength of the second emission peak is shortened. As a result, the emission spectrum of the CRT has a large deviation. Furthermore, in Comparative Example 3, since there is no third emission peak group, an index related to P3 cannot be defined, which is outside the scope of the present invention.

(Examples 7-11, Comparative Examples 4-6)
By using the white LEDs of Examples 1 and 3 to 9 and Comparative Examples 1 to 3 and combining with a color filter generally used in industrial applications, ITU-R BT. A full-color liquid crystal display device corresponding to the color gamut of the 709 standard was manufactured.

  With the white LED lit, the light passing through the color filter is guided to an integrating sphere, and the red (R), green (G), and blue (B) emission colors are evaluated, and a full-color liquid crystal display (display) The color gamut (color reproducibility) at the time of setting was examined. For color reproducibility, the coordinates of the light emission points of green, blue and red were measured using the CIE chromaticity diagram shown in FIG. Further, the white chromaticity was determined. In addition, as Comparative Example 7, the emission coordinates of each color of light emitted from a CRT (Mitsubishi Electric Co., Ltd., RDS-15X) displaying all GBR were also examined. The results are shown in Table 3.

  As shown in Table 3, the full-color liquid crystal display device according to the present embodiment is the same as the ITU-R BT. It was found that the color reproducibility conformed to the 709 standard. On the other hand, in the comparative example, at least one color of green chromaticity, blue chromaticity, and red chromaticity is out of chromaticity when the conventional CRT is used, and ITU-R BT. It was difficult to say that it had color reproducibility conforming to the 709 standard.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

1 Light-emitting diode (light-emitting element)
2 Phosphor layer 3 Reflecting layer 4 Resin frame 5 Wiring 6 Substrate 10 White LED

Claims (7)

At least one light emitting element selected from an ultraviolet light emitting diode, a blue-violet light emitting diode, an ultraviolet light emitting laser, and a blue-violet light emitting laser, which emits primary light having an emission peak in a wavelength region of 360 to 430 nm;
A blue phosphor that emits blue light having an emission peak in a wavelength region of 430 to 470 nm when excited by the primary light, and a green phosphor having an emission peak in a wavelength region of 520 to 560 nm that is excited by the primary light. A phosphor layer including a green phosphor emitting light and a red phosphor excited by the primary light and emitting red light having two or more linear emission peaks in a wavelength region of 580 to 740 nm; ,
A white LED for a backlight of a full-color liquid crystal display device,
The blue phosphor is selected from a divalent europium activated halophosphate phosphor, a divalent europium activated aluminate phosphor, a silver activated zinc sulfide phosphor, and a chlorine activated zinc sulfide phosphor. Consisting of at least one phosphor,
The green phosphor comprises at least one phosphor selected from europium and manganese activated alkaline earth magnesium orthosilicate phosphor, and europium activated sialon phosphor,
The red phosphor is a rare earth oxysulfide phosphor activated by at least one selected from europium and samarium;
The content of each color phosphor in the phosphor layer is 1 to 10% by weight of the green phosphor, 40 to 80% by weight of the blue phosphor, and the red phosphor with respect to the total amount of all the phosphors. 10 to 50% by weight, and the content of the phosphor powder contained in the phosphor layer is 30 to 80% by weight,
In the liquid crystal display device manufactured using the white LED, the color reproduction range of the emission color of the liquid crystal display device is represented by the (u ′, v ′) value of the chromaticity diagram of the L ^* u ^* v ^* color system. The chromaticity points of the primary colors of blue, green and red of the emission color are ITU-R BT. A white LED for a backlight of a full-color liquid crystal display device, wherein 709 is within a range of ± 0.02 or less with respect to the chromaticity points of the primary colors 709 of blue, green and red. The emission spectrum of white light emitted by the white LED is
A first emission peak group having at least one emission peak in a wavelength region of 430 to 470 nm;
A second emission peak group having at least one emission peak in a wavelength region of 520 to 560 nm;
A third emission peak group having at least two emission peaks in a wavelength region of 580 to 740 nm, and at least two of the emission peaks being linear emission peaks;
Including a trough that shows a minimum value of emission intensity in a wavelength region of more than 470 nm and less than 520 nm in a wavelength region of 480 to 500 nm,
When the maximum value P1 of the emission intensity of the emission peak in the first emission peak group is 1.0, the maximum value P2 of the emission intensity of the emission peak in the second emission peak group is 0.1 ≦ P2 ≦. 1.0, the maximum value P3 of the emission intensity of the emission peak in the third emission peak group is 0.2 ≦ P3 ≦ 3.0, and the minimum value V1 of the emission intensity of the valley is 0.01 ≦ V1 ≦. 2. The white LED for backlight of a full-color liquid crystal display device according to claim 1, which has a light emission intensity P _{600 at 600} nm of 50% or less of P3. The green phosphor includes a divalent europium and manganese activated silicate phosphor substantially represented by the following general formula 1, and a europium activated sialon phosphor substantially represented by the following general formula 2 or 3. 3. The white LED for backlight of a full-color liquid crystal display device according to claim 1, wherein the white LED is made of at least one green phosphor selected from the following.
[Chemical 1]
Formula _{1: (Sr 2-x-} y-z-u Ba x Mg y Eu z Mn u) SiO 4
(Wherein x, y, z and u satisfy 0.1 <x <1.0, 0 ≦ y <0.21, 0.05 <z <0.3, 0 ≦ u <0.04. Value)
[Chemical 2]
Formula _{2: (Sr 3-x Eu} x) Si y Al z O v N w
(Wherein x, y, z, v and w are numbers satisfying 0 <x ≦ 3, 12 <y <14, 2 <z <3.5, 1 <v <3, 20 <w <22. is there)
[Chemical formula 3]
General formula 3: (Si, Al) ₆ (O, N) ₈ : Eu _x
(Where x is a number satisfying 0 <x <0.3) The blue phosphor is a divalent europium-activated halophosphate phosphor substantially represented by the following general formula 4, and a divalent europium-activated aluminate fluorescence substantially represented by the following general formula 5 And at least one blue phosphor selected from a silver-activated zinc sulfide phosphor substantially represented by the following general formula 6 and a chlorine-activated zinc sulfide phosphor substantially represented by the following general formula 7 The white LED for a backlight of a full-color liquid crystal display device according to claim 1, wherein the white LED is a backlight.
[Chemical formula 4]
General formula 4: (M ² , Eu) ₁₀ (PO ₄ ) ₆ · Cl ₂
(Wherein M ² represents at least one element selected from Mg, Ca, Sr and Ba)
[Chemical formula 5]
Formula 5: a (M ³ , Eu) O · bAl ₂ O ₃
(Wherein M ³ represents at least one element selected from Mg, Ca, Sr, Ba, Zn, Li, Rb and Cs, and a and b are 0 <a, 0 <b, 0.2 ≦ a / b ≦ 1.5 is satisfied)
[Chemical 6]
General formula 6: (Zn _1-x Ag _x ) S
(Wherein x is a number satisfying 0 <x <0.01)
[Chemical 7]
Formula 7: (Zn _1-x Cl _x ) S
(Wherein x is a number satisfying 0 <x <0.01) 5. The red phosphor is a rare earth oxysulfide phosphor activated by at least one selected from europium and samarium substantially represented by the following general formula 8. A white LED for a backlight of the full-color liquid crystal display device according to any one of the above.
[Chemical 8]
Formula 8: _{(La 1-x over y-z Y x Sm y Eu} z) 2 O 2 S
(Wherein x, y and z satisfy 0 ≦ x <0.99, 0 ≦ y <0.03, 0.01 <z <0.15, and 1−x−yz ≦ 0) Value) It claims 1 to backlight for a full-color liquid crystal display device characterized by using a white LED according to any one of Item 5. A full-color liquid crystal display device produced using the backlight according to claim 6 .

Images