JP2009192662A - Color filter and liquid crystal display device using the same - Google Patents

Abstract

Provided are a color filter and a liquid crystal display device that improve the luminance while maintaining a high color reproducibility of the liquid crystal display device when a white LED mixed with a blue LED and a YAG phosphor is used as a backlight. .
The pixel consists of at least red, green, and blue pixels. I. Pigment Green 58 is contained. The green pixel has C.I. I. Pigment Green 58 and C.I. I. Pigment Yellow 150 is contained. The green pixel has C.I. I. Pigment Green 58 and C.I. I. Pigment Yellow 138 is contained.
[Selection] Figure 1

Description

  The present invention relates to C.I. I. The present invention relates to a color filter having a green pixel containing pigment green 58 and a liquid crystal display device using the same.

  In recent years, liquid crystal display devices have been rapidly spread in many applications such as television image display devices, computer terminal display devices, mobile terminal liquid crystal display devices for mobile applications, and liquid crystal display devices for in-vehicle use. Competition in display image quality is intensifying.

  TV images can now be distributed on computer terminals and mobile terminals as well as TV, and with the impact of the start of terrestrial digital broadcasting, all applications have image quality equivalent to or higher than conventional TV standards. Many liquid crystal display devices are required to have high contrast, high speed response, high color reproducibility, high luminance, and the like.

  Among them, high color reproducibility and high brightness are characteristics that depend on the backlight light source and color filter provided in the liquid crystal display device. For the backlight, portable devices such as mobile phones and PDAs (Personal Digital Assistants). As for the light source, an LED that is smaller and lighter than a conventional cold cathode fluorescent lamp (CCFL), particularly a white LED using a YAG phosphor, is often used as a light source. Yes. Compared with CCFL, LED has advantages such as excellent responsiveness, low power consumption, mercury-free and environmental friendliness.

  In the color filter, as disclosed in the following Patent Document 1 and Patent Document 2, C.I. I. Although it is publicly known to use the pigment green 36, a high transmittance is not obtained, and even when a white LED mixed with a combination of a red LED, a green LED, and a blue LED is used as a light source. In order to improve the luminance, a high transmittance is desired.

In addition, the method of increasing the pigment concentration to improve color reproducibility and using a color filter with high color purity has been proposed as the most promising method, but the amount of light that passes through the color filter increases as the color purity increases. There is a problem that the luminance decreases and the luminance decreases, and it is difficult to achieve both high color reproducibility and high luminance.
JP 2004-163902 A JP 2006-47975 A

  The present invention is for solving the above problem, and when a white LED mixed with a blue LED and a YAG phosphor is used for a backlight, while maintaining high color reproducibility of the liquid crystal display device. It is an object to provide a color filter capable of improving luminance and a liquid crystal display device using the color filter.

The present invention relates to a color filter used in a liquid crystal display device using a white LED mixed with a blue LED and a YAG phosphor as a backlight. The color filter includes at least a red pixel, a green pixel, and a blue pixel. Configured, and the green pixel has C.I. I. This is a color filter containing Pigment Green 58.

  According to the present invention, in the color filter according to the above invention, C.I. I. Pigment Green 58 and C.I. I. A color filter containing Pigment Yellow 150.

  The present invention also provides the color filter according to the above invention, wherein the C.I. I. Pigment Green 58 and C.I. I. The weight percentage ratio of CI Pigment Yellow 150 is [90 to 16]: [10 to 84].

  According to the present invention, in the color filter according to the above invention, C.I. I. Pigment Green 58 and C.I. I. A color filter containing Pigment Yellow 138.

  The present invention also provides the color filter according to the above invention, wherein the C.I. I. Pigment Green 58 and C.I. I. The color filter is characterized in that the pigment yellow 138 has a weight percentage ratio of [92 to 17]: [8 to 83].

  Moreover, this invention is a liquid crystal display device using the color filter as described in any one of Claims 1-5.

  The present invention includes a red pixel, a green pixel, and a blue pixel. I. Since it is a color filter that contains CI Pigment Green 58, while using a white LED that is a mixture of red LED, green LED, and blue LED in the backlight, the color reproducibility of the liquid crystal display device is kept high. The color filter can improve the luminance (brightness of display).

Hereinafter, the color filter and the liquid crystal display device of the present invention will be described in detail based on the embodiments thereof.
The liquid crystal display device according to an embodiment of the present invention uses a white LED in which a blue LED and a YAG phosphor are combined and mixed as a backlight. An example of the white LED has a light emission characteristic as shown in FIG. 1, and is different from an emission spectrum characteristic of an example of a cold cathode fluorescent tube (CCFL) used in the conventional liquid crystal display device shown in FIG. .

Accordingly, the present invention uses a white LED in which a blue LED and a YAG phosphor are combined and mixed in a liquid crystal display device, and a green pixel has C.I. I. By providing a color filter containing Pigment Green 58, it was possible to improve luminance while maintaining high color reproducibility.
For green pixels, C.I. I. Pigment yellow 150 or C.I. I. Pigment Yellow 138 is contained.

  As shown in FIG. I. Pigment Green 58 has a transmittance of 490 nm to 630 nm as C.I. I. Since it is higher than the pigment green 36 and the hue is yellowish, the blending ratio of the yellow pigment used for toning can be reduced. As a result, C.I. I. A bright color filter with less turbidity, excellent color purity, and brighter color than when using CI Pigment Green 36 can be obtained.

  The color filter included in the liquid crystal display device according to the present embodiment is a color filter including at least a red pixel, a green pixel, and a blue pixel on a transparent substrate, and each of these color pixels includes an organic pigment and a transparent resin as main components. It is what. In addition, yellow, magenta, cyan, orange, and the like arranged in the same manner can be applied to each color pixel.

Hereinafter, a method for obtaining the color filter according to the present invention will be described in detail.
The transparent substrate used for the substrate of the color filter preferably has a certain degree of transmittance with respect to visible light, and more preferably has a transmittance of 80% or more. Generally, it may be one used in a liquid crystal display device, and examples thereof include a plastic substrate such as PET and glass, but a glass substrate is usually used. In the case of using a light shielding pattern, a material obtained by previously attaching a metal thin film such as chromium or a lattice pattern with a light shielding resin on the transparent substrate may be used.

  The method for producing each color pixel on the transparent substrate may be produced by any known method such as an inkjet method, a printing method, a photoresist method, or an etching method. However, considering high definition, controllability of spectral characteristics, color reproducibility, etc., a transparent photosensitive photosensitive composition in which a pigment is dispersed in a transparent resin together with a photoinitiator and a polymerizable monomer is transparent. A photoresist method is preferred in which a color filter is formed by repeating the process of forming a pixel of one color by forming a coating film on a substrate, pattern exposure to the coating film, and development for each color.

  Preparation of the photosensitive coloring composition used for formation of each color pixel follows the following method, for example. A pigment serving as a colorant is dispersed in a transparent resin, and then mixed with an appropriate solvent together with a photoinitiator and a polymerizable monomer. There are various methods such as a mill base, three rolls, and a jet mill for dispersing the pigment as the colorant and the transparent resin, and the method is not particularly limited.

Specific examples of organic pigments that can be used in the photosensitive coloring composition used for forming each color pixel are shown by color index numbers.
Examples of red pigments include C.I. I. Pigment Red 254, 7, 9, 14, 41, 48: 1, 48: 2, 48: 3, 48: 4, 81: 1, 81: 2, 81: 3, 97, 122, 123, 146, 149, 168, 177, 178, 179, 180, 184, 185, 187, 192, 200, 202, 208, 210, 215, 216, 217, 220, 223, 224, 226, 227, 228, 240, 246, 255, H.264, 272, 279 and the like.

  Examples of yellow pigments include C.I. I. In addition to Pigment Yellow 150 and PY138, PY1, 2, 3, 4, 5, 6, 10, 12, 13, 14, 15, 16, 17, 18, 20, 24, 31, 32, 34, 35, 35 : 1, 36, 36: 1, 37, 37: 1, 40, 42, 43, 53, 55, 60, 61, 62, 63, 65, 73, 74, 77, 81, 83, 86, 93, 94 95, 97, 98, 100, 101, 104, 106, 108, 109, 110, 113, 114, 115, 116, 117, 118, 119, 120, 123, 125, 126, 127, 128, 129, 137 139, 144, 146, 147, 148, 151, 152, 153, 154, 155, 156, 161, 162, 164, 166, 167, 168, 169, 170, 17 1,172,173,174,175,176,177,179,180,181,182,185,187,188,193,194,199,213,214 etc. are mentioned.

Examples of orange pigments include C.I. I. Pigment Orange 36, 43, 51, 55, 59, 61, 71, 73 and the like.
Examples of green pigments include C.I. I. In addition to Pigment Green 58, PG7, 10, 36, 37, and the like can be given.
Examples of blue pigments include C.I. I. Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 22, 60, 64, 80 and the like.
Examples of purple pigments include C.I. I. Pigment Violet 1, 19, 23, 27, 29, 30, 32, 37, 40, 42, 50, and the like.

  The above pigments can be used alone or in combination of two or more. In combination with the organic pigment, an inorganic pigment may be used in combination in order to ensure good coatability, sensitivity, developability and the like while balancing saturation and lightness. Examples of inorganic pigments include yellow lead, zinc yellow, red pepper, cadmium red, ultramarine blue, bitumen, chromium oxide green, cobalt green, and other metal oxide powders, metal sulfide powders, and metal powders. Furthermore, for color matching, a dye can be contained within a range that does not lower the heat resistance.

  The transparent resin used for the photosensitive coloring composition is a resin having a transmittance of preferably 80% or more, more preferably 95% or more in the entire wavelength region of 400 to 700 nm in the visible light region. The transparent resin includes a thermoplastic resin, a thermosetting resin, and a photosensitive resin. If necessary, the transparent resin can be used alone or in admixture of two or more monomers or oligomers that are precursors thereof that are cured by irradiation with radiation to produce a transparent resin.

  Examples of the thermoplastic resin include butyral resin, styrene-maleic acid copolymer, chlorinated polyethylene, chlorinated polypropylene, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyurethane resin, and polyester resin. , Acrylic resins, alkyd resins, polystyrene, polyamide resins, rubber resins, cyclized rubber resins, celluloses, polyethylene, polybutadiene, polyimide resins, and the like. Examples of the thermosetting resin include epoxy resins, benzoguanamine resins, rosin-modified maleic acid resins, rosin-modified fumaric acid resins, melamine resins, urea resins, and phenol resins.

  Examples of the photosensitive resin include (meth) acrylic compounds having a reactive substituent such as an isocyanate group, an aldehyde group, and an epoxy group on a linear polymer having a reactive substituent such as a hydroxyl group, a carboxyl group, or an amino group, A resin obtained by reacting an acid and introducing a photocrosslinkable group such as a (meth) acryloyl group or a styryl group into the linear polymer is used. In addition, linear polymers containing acid anhydrides such as styrene-maleic anhydride copolymer and α-olefin-maleic anhydride copolymer can be obtained from (meth) acrylic compounds having hydroxyl groups such as hydroxyalkyl (meth) acrylate. Half-esterified products are also used.

  Examples of polymerizable monomers that can be used as a photocrosslinking agent include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and ethylene oxide-modified trimethylolpropane tri (meth). Representative examples include various acrylic esters and methacrylic esters such as acrylate and propylene oxide-modified trimethylolpropane tri (meth) acrylate. These can be used alone or in combination of two or more, and for the purpose of maintaining appropriate photocurability, other polymerizable monomers and oligomers can be mixed and used as necessary.

  Other polymerizable monomers and oligomers include methyl (meth) acrylate, ethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, cyclohexyl (meth) acrylate, β-carboxyethyl (Meth) acrylate, diethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, triethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate , Pentaerythritol tri (meth) acrylate, 1,6-hexanediol diglycidyl ether di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate , Neopentyl glycol diglycidyl ether di (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tricyclodecanyl (meth) acrylate, ester acrylate, (meth) acrylic acid ester of methylolated melamine, epoxy (meth) acrylate , Various acrylates and methacrylates such as urethane acrylate, (meth) acrylic acid, styrene, vinyl acetate, hydroxyethyl vinyl ether, ethylene glycol divinyl ether, pentaerythritol trivinyl ether, (meth) acrylamide, N-hydroxymethyl (meth) ) Acrylamide, N-vinylformamide, acrylonitrile and the like. Also about these, it can use individually or in mixture of 2 or more types.

  When the composition is cured by ultraviolet irradiation, a photopolymerization initiator or the like is added to the photosensitive coloring composition. As photopolymerization initiators, 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1- Acetophenone compounds such as hydroxycyclohexyl phenyl ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl Benzoin compounds such as dimethyl ketal, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 3 Benzophenone compounds such as 3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, 2,4- Thioxanthone compounds such as diethylthioxanthone, 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, 2- (p-methoxyphenyl) -4,6 -Bis (trichloromethyl) -s-triazine, 2- (p-tolyl) -4,6-bis (trichloromethyl) -s-triazine, 2-piperonyl-4,6-bis (trichloromethyl) -s-triazine 2,4-bis (trichloromethyl) -6-styryl-s-triazine, 2- (naphth-1-yl) -4,6-bis (trichloro) Methyl) -s-triazine, 2- (4-methoxy-naphth-1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2,4-trichloromethyl- (piperonyl) -6-triazine, Triazine compounds such as 2,4-trichloromethyl (4′-methoxystyryl) -6-triazine, 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], Oxime ester compounds such as O- (acetyl) -N- (1-phenyl-2-oxo-2- (4′-methoxy-naphthyl) ethylidene) hydroxylamine, bis (2,4,6-trimethylbenzoyl) phenyl Phosphine compounds such as phosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 9,10-phenanthrenequinone, camphorquinone, ethyl anthraquino Quinone compounds such as borate compounds, carbazole compounds, imidazole compounds, titanocene compounds and the like. These photopolymerization initiators can be used alone or in combination. The amount of the photopolymerization initiator used is preferably 0.5 to 50% by mass, more preferably 3 to 30% by mass, based on the total solid content of the photosensitive coloring composition.

Further, as sensitizers, triethanolamine, methyldiethanolamine, triisopropanolamine, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, 2-dimethylaminoethyl benzoate, 2-Ethylhexyl 4-dimethylaminobenzoate, N, N-dimethylparatoluidine, 4,4′-bis (dimethylamino) benzophenone, 4,4′-bis (diethylamino) benzophenone, 4,4′-bis (ethylmethyl) Amine compounds such as amino) benzophenone can also be used in combination. These sensitizers can be used alone or in combination. The amount of the sensitizer used is preferably 0.5 to 60% by mass, more preferably 3 to 40% by mass based on the total amount of the photopolymerization initiator and the sensitizer.

  Furthermore, the photosensitive coloring composition can contain a polyfunctional thiol that functions as a chain transfer agent. The polyfunctional thiol may be a compound having two or more thiol groups. For example, hexanedithiol, decanedithiol, 1,4-butanediol bisthiopropionate, 1,4-butanediol bisthioglycolate, ethylene Glycol bisthioglycolate, ethylene glycol bisthiopropionate, trimethylolpropane tristhioglycolate, trimethylolpropane tristhiopropionate, trimethylolpropane tris (3-mercaptobutyrate), pentaerythritol tetrakisthioglycolate, Pentaerythritol tetrakisthiopropionate, tris (2-hydroxyethyl) isocyanurate trimercaptopropionate, 1,4-dimethylmercaptobenzene, 2,4,6-trimercapto-s-to Azine, 2- (N, N- dibutylamino) -4,6-dimercapto -s- triazine. These polyfunctional thiols can be used alone or in combination.

  Moreover, as needed, as a thermal crosslinking agent, a melamine resin, an epoxy resin, etc. are mentioned, for example. Examples of the melamine resin include alkylated melamine resins (methylated melamine resin, butylated melamine resin, etc.), mixed etherified melamine resins, and the like, which may be a high condensation type or a low condensation type. Examples of the epoxy resin include glycerol / polyglycidyl ether, trimethylolpropane / polyglycidyl ether, resorcin / diglycidyl ether, neopentyl glycol / diglycidyl ether, 1,6-hexanediol / diglycidyl ether, ethylene glycol (polyethylene). Glycol) and diglycidyl ether. Any of these may be used alone or in admixture of two or more.

  The photosensitive coloring composition can contain an organic solvent as necessary. Examples of the organic solvent include cyclohexanone, ethyl cellosolve acetate, butyl cellosolve acetate, 1-methoxy-2-propyl acetate, diethylene glycol dimethyl ether, ethylbenzene, ethylene glycol diethyl ether, xylene, ethyl cellosolve, methyl-n amyl ketone, propylene glycol monomethyl ether toluene, Examples include methyl ethyl ketone, ethyl acetate, methanol, ethanol, isopropyl alcohol, butanol, isobutyl ketone, petroleum solvent, and the like. These may be used alone or in combination.

  As a blending method of each component as described above, for example, a transparent resin and a pigment are kneaded well using two rolls to form a chip, and then a solvent is added to form a paste. A method of obtaining a photosensitive coloring composition by adding an agent and a sensitizer as required.

  A photosensitive coloring composition is applied onto a transparent substrate and prebaked. Spin coating, dip coating, die coating, and the like are usually used as the means for coating, but the coating means is not limited to these as long as it can be coated with a uniform film thickness on a 40 to 60 cm square substrate. Prebaking is preferably performed at 50 to 120 ° C. for about 10 to 20 minutes. The coating film thickness is arbitrary, but considering the spectral transmittance and the like, the film thickness after pre-baking is usually about 2 μm. The substrate on which the photosensitive coloring composition is applied and a coating film is formed is exposed through a photomask. A normal high-pressure mercury lamp or the like may be used as the light source.

  Subsequently, development is performed. An alkaline aqueous solution is used as the developer. Examples of the alkaline aqueous solution include a sodium carbonate aqueous solution, a sodium hydrogen carbonate aqueous solution, a mixed aqueous solution of the two, or a mixture obtained by adding an appropriate surfactant to them. After development, it is washed with water and dried to obtain a pixel of any one color.

  By repeating the above-described series of steps by changing the photosensitive coloring composition and the photomask as many times as necessary, a color filter including each color pixel in which the necessary number of colors are combined can be obtained.

An example of a configuration of a liquid crystal display device including an LED and a color filter as a backlight will be described.
FIG. 3 is a schematic sectional view of the liquid crystal display device of the present invention. The liquid crystal display device of FIG. 3 is a typical example of a TFT drive type liquid crystal display device, and includes transparent substrates 11 and 21 arranged to face each other, and liquid crystal (LC) is sealed between them. The liquid crystal display device of the present invention includes liquid crystal such as TN (Twisted Nematic), STN (Super Twisted Nematic), IPS (In-Planes Switching), VA (Vertical Alignment), OCB (Optically Compensated Birefringence), and ferroelectric liquid crystal. Is applicable.

  A TFT (Thin Film Transistor) array 12 is formed on the inner surface of the first transparent substrate 11, and a transparent electrode layer 13 made of, for example, ITO is formed thereon. An alignment layer 14 is provided on the transparent electrode layer 13. A polarizing plate 15 is formed on the outer surface of the transparent substrate 11.

  On the other hand, the color filter 22 of the present invention is formed on the inner surface of the second transparent substrate 21. Red, green and blue pixels constituting the color filter 22 are separated by a black matrix (not shown). A transparent protective film (not shown) is formed so as to cover the color filter 22 and further, a transparent electrode layer 23 made of, for example, ITO is formed thereon, and the alignment layer 24 covers the transparent electrode layer 23. Is provided. A polarizing plate 25 is formed on the outer surface of the transparent substrate 21. Note that the backlight unit 30 of the present invention is provided below the polarizing plate 15.

(Preparation of pigment dispersion paste)
As shown in Table 1, the pigment dispersion paste was prepared by uniformly stirring and mixing a pigment and an acrylic resin and propylene glycol monomethyl ether acetate (hereinafter referred to as PGMEA), and using a zirconia bead having a diameter of 1.0 mm in a sand mill. After dispersing for 3 hours, the mixture was filtered through a 5 μm filter to prepare a pigment dispersion paste. All composition ratios are weight ratios.

(Preparation of photosensitive coloring composition)
The photosensitive coloring composition was prepared by blending each component in the ratio shown in Table 2, stirring and mixing with a stirrer until each component was completely dissolved, and filtering through a 1 μm filter.

The red photosensitive coloring composition used for forming the red pixel is a red photosensitive coloring composition having a pigment ratio (weight percentage) as shown in Table 6 (in Table 2, R-1 is [54.25: 4]. .08] = [93: 7]).

Moreover, the green photosensitive coloring composition used for formation of a green pixel is the green photosensitive coloring compositions G-1 to G-20 of the pigment ratio (weight percentage) as shown in Tables 7 and 8.

Moreover, the blue photosensitive coloring composition used for formation of a blue pixel is a blue photosensitive coloring composition of a pigment ratio (weight percentage) as shown in Table 9.

With respect to the photosensitive coloring composition having the above pigment ratio, the red pixel is x = 0.640, the green pixel is y = 0.600, and the blue pixel is y = 0.600 in the chromaticity coordinates xy of the CIE1931XYZ color system. A three-color filter was prepared by adjusting the combinations shown in the following examples and comparative examples. The adjustment chromaticity value is based on the EBU standard value, which is a broadcast standard, but is not limited to this range.

  The red photosensitive coloring composition is R-1 in Table 2 (Table 6), the blue photosensitive coloring composition is B-1 in Table 5 (Table 9), and the green photosensitive coloring composition is Table 2, 3 ( Using G-1 to G-10 of Table 7), a three-color filter was produced with the above-mentioned designated chromaticity aim. Examples 1 to 10 are combinations of backlights each including a white LED in which the color filter, the blue LED, and the YAG phosphor are mixed and mixed.

The red photosensitive coloring composition is R-1 in Table 2 (Table 6), the blue photosensitive coloring composition is B-1 in Table 5 (Table 9), and the green photosensitive coloring composition is Table 4. 5 (Table 8) G-11 to G-20 were used to produce a three-color color filter with the above-mentioned designated chromaticity aim.
Comparative examples 11 to 20 are combinations of backlights each including a white LED in which the color filter, the blue LED, and the YAG phosphor are mixed and mixed.

〔Evaluation item〕
(brightness)
The lightness (G−Y) of the green pixel and the lightness (W−Y) in white display as a color filter are represented by C.I. I. Pigment Green 58 (PG58) and C.I. I. In the case of using Pigment Green 36 (PG36), the brighter one was marked with ◯ and the lower one with x.

〔Evaluation results〕
The evaluation results of Examples 1 to 10 are shown in Table 10, and the results of Comparative Examples 11 to 20 are shown in Table 11. The chromaticity values in Tables 10 and 11 are xy chromaticity and Y (lightness) in the CIE1931 XYZ color system.

From the results of Tables 10 and 11, the following is clear. That is, the lightness (G−Y) of the green pixel and the lightness (W−Y) in the white display as the color filter are calculated as C.I. I. Pigment Green 58 (PG58) and C.I. I. As a result of comparison in the case of using CI Pigment Green 36 (PG36), (G−Y) and (W−Y) are C.I. I. It can be seen that when the pigment green 58 (PG58) is used, it becomes high and high luminance is realized.

It is a characteristic view which shows the light emission characteristic of an example of white LED which mixed blue LED and YAG type | system | group fluorescent substance and mixed colors. It is a characteristic view which shows the light emission characteristic of an example of a cold cathode fluorescent tube (CCFL). It is general | schematic sectional drawing of the structural example of a liquid crystal display device. C. I. It is a spectral transmittance curve of Pigment Green 58.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11, 21 ... Transparent substrate 12 ... TFT array 13, 23 ... Transparent electrode 14, 24 ... Alignment film | membrane 15, 25 ... Polarizing plate 22 ... Color filter 30 ... Backlight unit

Claims (6)

  A color filter used in a liquid crystal display device using a white LED mixed with a combination of a blue LED and a YAG phosphor as a backlight, and the color filter includes at least a red pixel, a green pixel, and a blue pixel, The green pixel has C.I. I. A color filter containing Pigment Green 58.   C. is added to the green pixel. I. Pigment Green 58 and C.I. I. The color filter according to claim 1, comprising Pigment Yellow 150.   C. above. I. Pigment Green 58 and C.I. I. 3. The color filter according to claim 2, wherein the weight percentage ratio of CI Pigment Yellow 150 is [90-16]: [10-84].   C. is added to the green pixel. I. Pigment Green 58 and C.I. I. The color filter according to claim 1, wherein Pigment Yellow 138 is contained.   C. above. I. Pigment Green 58 and C.I. I. The color filter according to claim 4, wherein the weight percentage ratio of Pigment Yellow 138 is [92 to 17]: [8 to 83].   A liquid crystal display device using the color filter according to claim 1.