JP2000292780A - Projection liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a projection liquid crystal display device with natural coloring, bright and with excellent contrast. SOLUTION: The projection liquid crystal display device incorporates a polarizing plate having >=0.1% transmissivity in 520-570 nm wavelength region in the case linearly polarized light having a plane of vibration parallel to the direction of the absorption axis of the polarizing plate is made incident thereon and besides having >=83% transmissivity in 520-570 mm wavelength region in the case linearly polarized light having a plane of vibration orthogonal to the direction of the absorption axis of the polarizing plate is made incident thereon.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a projection type liquid crystal display device.

[0002]

2. Description of the Related Art Heretofore, a projection type liquid crystal display device in which a liquid crystal panel is incorporated in a video projector, a data projector, or the like is also called a liquid crystal projector, and includes a personal computer screen, a relay screen of sports such as baseball and soccer, and the like. It is often used as a display device for projecting and displaying a television screen or the like on a screen.

Such a projection type liquid crystal display device has three colors of light,
That is, light beams of each color of red (R), green (G), and blue (B) are projected on a liquid crystal panel corresponding to each color to obtain an image of each color, which is synthesized by a dichroic mirror or a dichroic prism. To obtain full-color images. Here, the light rays of each of the three colors are obtained by, for example, dispersing white light rays from a metal halide lamp, a high-pressure mercury lamp, or the like using a dichroic mirror or the like. In addition, as a polarizing plate used for a liquid crystal panel, a neutral gray polarizing plate is usually used for each color, and a polarizing plate having a polarizing film in which a dichroic dye is adsorbed and oriented in terms of heat resistance and light resistance to a light source. Is often used.

However, there is a case where natural color display cannot be obtained with a conventional projection type liquid crystal display device, and this tendency may be particularly remarkable when displaying a green color such as a lawn. Further, there has been a tendency that sufficient contrast and brightness cannot be obtained with a conventional projection type liquid crystal display device.

[0005]

Therefore, the present inventor has proposed:
As a result of intensive studies to develop a polarizing plate that can be formed as a projection type liquid crystal display device with natural coloring and excellent brightness and contrast, by using a polarizing plate with specific transmitted light characteristics for a liquid crystal panel through which green light passes, With natural coloring, bright,
In addition, they have found that a projection-type liquid crystal display device capable of providing an image with high contrast can be obtained, and have reached the present invention.

[0006]

That is, the present invention has a transmittance of 0.1% at a wavelength of 520 nm to 570 nm when linearly polarized light having a vibration plane parallel to the absorption axis direction of a polarizing plate is incident. The projection type incorporating a polarizing plate having a transmittance of 83% or more at a wavelength of 520 nm to 570 nm when linearly polarized light having a vibration plane orthogonal to the absorption axis direction of the polarizing plate is incident. A liquid crystal display device is provided.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A polarizing plate incorporated in a projection type liquid crystal display device of the present invention has a wavelength of 520 when linearly polarized light having a vibration plane parallel to the absorption axis direction of the polarizing plate is incident.
The transmittance at 0.1 nm to 570 nm is 0.1% or less. If the transmittance exceeds 0.1%, a sufficient contrast of the display screen tends not to be obtained. Further, the transmittance at a wavelength of 520 nm to 570 nm when linearly polarized light orthogonal to the absorption axis direction of the polarizing plate is incident is 8%.
3% or more. When the transmittance is less than 83%,
There is a tendency that sufficient brightness cannot be obtained. Note that the absorption axis direction of the polarizing plate is orthogonal to the transmission axis direction.

[0008] Such a polarizing plate usually comprises, for example, a polarizing film and a protective plate laminated on one or both sides thereof. The polarizing film constituting such a polarizing plate can be obtained by, for example, adsorbing and orienting a dichroic dye on a polyvinyl alcohol-based resin film. As the polyvinyl alcohol resin film, for example, polyvinyl alcohol, polyvinyl acetate, vinyl acetate and other monomers copolymerizable therewith, such as unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids and the like Examples thereof include a film made of a copolymer or the like, a polyvinyl formal film obtained by modifying these, a polyvinyl acetal film, and the like. The polyvinyl alcohol-based resin constituting such a polyvinyl alcohol-based resin film is usually used after being subjected to a saponification treatment.
１００100 mol%, preferably 98 mol% or more. The polymerization degree of the polyvinyl alcohol-based resin in the polyvinyl alcohol-based resin film is usually 1000 or more,
It is about 10,000 or less, preferably about 1500 to 5000, and more preferably about 2000 to 5000.
The thickness of the polyvinyl alcohol-based resin film is, for example, 5
It is about 0 to 150 μm.

The dichroic dyes include, for example, a compound of the formula (I) in the form of a free acid. (In the formula, Me represents copper, nickel, zinc, or iron.
¹ represents an optionally substituted phenyl group or naphthyl group. Shows the Le group - B ¹ is a metal complexing is bonded to the azo group in binding to and adjacent positions of the hydroxyl group, optionally substituted 1-naphthol - le or 2-naphtho. R ¹
And R ² are each independently a hydrogen atom,
4 represents an alkyl group, lower alkoxy group, carboxylic acid group, sulfonic acid group, sulfonamide group, sulfonalkylamide group, amino group, acylamino group, halogen atom, and nitro group. ) (Hereinafter referred to as dichroic dye (A)). ],

Formula (II) in the form of the free acid (Wherein A ³ and B ³ each independently represent a phenyl or naphthyl group which may be substituted, and R ³ and R ⁴
Are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a lower alkoxy group, a carboxylic acid group, a sulfonic acid group,
A sulfonamide group, a sulfonalkylamide group, an amino group, an acylamino group, a halogen atom, a nitro group,
m represents 0 or 1. ) (Hereinafter referred to as dichroic dye (B)). ],

In the form of the free acid, the general formula (III) Q ¹ -N = N-Q ² -X-Q ³ -N = N-Q ⁴ (III) (wherein Q ¹ and Q ⁴ are each independently Represents unsubstituted or substituted phenyl or unsubstituted or substituted naphthyl, wherein Q ² and Q ³ are each independently
X represents unsubstituted or substituted phenylene, and X represents -N
= N- or -N (→ O) = N-. With the proviso that when X is -N = N- and Q ² and Q ³ are both unsubstituted phenylene, Q ¹ and Q ⁴ simultaneously have an alkyl-substituted amino and are not substituted with additional groups Or phenyl further substituted with methyl. Dichroic dye [hereinafter referred to as dichroic dye (C)]
And ],

General formula (IV) (Wherein Me represents a transition metal selected from copper, nickel, zinc and iron, and Q ⁵ and Q ⁶ each independently represent an unsubstituted or substituted 1-naphthol residue or an unsubstituted or substituted Represents a 2-naphthol residue,
The hydroxy of the naphthol residue is adjacent to the azo group and is complexed with a transition metal represented by Me, and Y is-
N = N-or -N (→ O) = N- are shown, represents hydrogen, lower alkyl, lower alkoxy or sulfo and R ⁵ and R ⁶ are each independently. ) (Hereinafter referred to as dichroic dye (D)). ],

In the form of the free acid, the following formula (V) or (VI) (In formula (I), Q ¹ represents an unsubstituted or substituted phenyl or unsubstituted or substituted naphthyl, Q ²
Represents phenyl which has at least one substituent selected from hydroxy and unsubstituted or substituted amino and may be further substituted; R ¹ , R ² , R ³ and R ⁴ each independently represent Represents hydrogen, hydroxy, lower alkyl, lower alkoxy or unsubstituted or substituted amino. ) [Hereinafter referred to as dichroic dye (E). 〕,and,

She-I Direct Yellow-12,
C.I.Direct Bull-202, C.I.
Direct Red 31, C-I Direct Violet 9, C-I Direct Yellow-4
4. C.I.Direct Yellow-28, C.I.Direct Orange 107, C.I.Direct Red 79, C.I.Direct Blue-7
1, C.I.Direct Blue-78, C.I.Direct Red 2, C.I.Direct Red 81, C.I.Direct Violet 5
1, C.I.Direct Orange 26, C.I.Direct Orange 39, C.I.Direct Red 247, C.I.Direct Blue-1
68, C.I.Direct Green 85, C.I.
Eye Direct Brown 223, C.I.Direct Brown 106, C.I.Direct Yellow 142 and C.I.Direct Blue-1
The dichroic dye represented by the group consisting of [hereinafter referred to as dichroic dye (F)]. ] And so on.

In the dichroic dye (A), Me in the general formula (I) is preferably a copper atom. Specific examples of the dichroic dye (A) include the following (I-1) to (I)
-24).

[0016]

[0017]

[0018]

Examples of the dichroic dye (B) include compounds represented by the following (II-1) to (II-11).

[0020]

[0021]

Examples of the dichroic dye (C) include the compounds represented by the following (III-1) to (III-22).

[0023]

[0024]

[0025]

The dichroic dye (A), the dichroic dye (B) and the dichroic dye (C) are usually used in the form of an alkali metal salt, especially a sodium salt. It may be dispersed in the form of a salt or the like and used in the form of a free acid. Further, it may be used in the form of an amine salt such as an ammonium salt, an ethanolamine salt or an alkylamine salt.

The dichroic dye (D) has the general formula (IV)
Is preferably a copper atom.

In the dichroic dye (E), the compound represented by the general formula (V)
And Q ¹ in the general formula (VI) is phenyl or naphthyl, and each may be unsubstituted or substituted. Examples of the phenyl substituent include nitro, sulfo, sulfamoyl, alkyl, alkoxy, hydroxy, unsubstituted or substituted amino,
Examples include carboxy and halogeno, and examples of the amino substituent include methyl, ethyl, acetyl, β-hydroxyethyl, and the like. In addition, examples of the substituent of naphthyl include hydroxy and sulfo. Preferred as phenyl represented by Q ¹ are unsubstituted phenyl, nitro, sulfo, sulfamoyl, C ₁ -C ₄ alkyl, C ₁ -C ₄ alkoxy,
Phenyl substituted with one or two substituents selected from hydroxy, unsubstituted or substituted amino, carboxy and halogeno. Such a preferred phenyl is represented by the following chemical formula. (Wherein R ⁵ and R ⁶ are each independently hydrogen, nitro, sulfo, sulfamoyl, C ₁ -C ₄ alkyl, C
₁ -C ₄ alkoxy, hydroxy, unsubstituted or substituted amino, a carboxy or halogeno. ) Among them, nitro, sulfo, sulfamoyl, methyl,
Phenyl substituted with ethyl, methoxy, ethoxy, carboxy or chloro is preferred.

The naphthyl represented by Q ¹ is preferably 2-naphthyl, and includes unsubstituted 2-naphthyl and 2-naphthyl substituted with 1 to 3 substituents selected from hydroxy and sulfo. Can be Such a preferred naphthyl is represented by the following chemical formula. (In the formula, R ⁷ , R ⁸ and R ⁹ each independently represent hydrogen, hydroxy or sulfo.) Among them, naphthyl substituted once or twice with sulfo is preferable.

In the general formulas (V) and (VI)
Q^TwoIs hydroxy and unsubstituted or substituted
Having at least one substituent selected from amino
Phenyl which may be further substituted
Examples of the substituent of include, for example, methyl, ethyl, β-hydrido
Roxyethyl, β-cyanoethyl, acetyl, carbamo
Yl, methylsulfonyl and the like. Also Hyde
In addition to roxy and amino, Q^TwoTo the phenyl represented by
The groups which may be substituted include sulfo, C₁~ C_Four Archi
Le, C₁~ C_FourAlkoxy, carboxy, etc.
You.

The phenyl represented by Q ² is substituted one to three times with hydroxy, and may be further substituted with unsubstituted or substituted amino, sulfo, alkyl, alkoxy or carboxy, or Substituted once or twice with unsubstituted or substituted amino, and further substituted with hydroxy, sulfo, alkyl,
Preference is given to phenyl optionally substituted by alkoxy or carboxy. Among them, the case where Q ² is 4-hydroxyphenyl is exemplified as a preferable example.

In the formulas (V) and (VI), R ¹ , R ² , R ³ and R ⁴ are each independently hydrogen, hydroxy, lower alkyl, lower alkoxy or unsubstituted or substituted amino. In this case, the lower alkyl and the lower alkoxy may each have about 1 to 4 carbon atoms, and examples of the amino substituent include methyl, ethyl, acetyl, carbamoyl and methylsulfonyl. Preferred R ¹ , R ² , R ³
And R ⁴ are each independently hydrogen, hydroxy, methyl, ethyl, methoxy, ethoxy, acetylamino,
Methylsulfonylamino, ureido or methylamino. In the compound represented by the formula (VI), R ⁴ is hydroxy in the compound of the formula (V), and the hydroxy and 1-hydroxy-3-sulfo-2,6
-A copper complex formed with hydroxy of naphthylene.

Each of such dichroic dyes can be produced by a known method. For example, dichroic dyes (A) are described, for example, in German Offenlegungsschrift 3236238.
And the dichroic dye (B) can be produced by a known method described in, for example, JP-A-2-75672. Dichroic dyes (C, D,
E) is, for example, Ind. Eng. Chem., 27, 1045 (1935), J. Am.
em. Soc., 73, 1323 (1951). One of these dichroic dyes may be used, or two or more may be used in combination.

In order to adsorb and orient the dichroic dye on the polyvinyl alcohol resin film, for example, the polyvinyl alcohol resin film may be stretched and immersed in an aqueous solution of the dichroic dye.

The concentration of the dichroic dye in the aqueous solution used in the immersion treatment is usually 0.0
001 to 1 part by weight, and the temperature of the aqueous solution is usually 30
C. to about 85.degree. C., preferably about 60.degree. Note that a dyeing aid may be added to the aqueous solution. For example, when using Glauber's salt as a dyeing aid, the amount used is about 0.5 to 10 parts by weight with respect to 100 parts by weight of water. The polyvinyl alcohol-based resin film may be subjected to a dipping treatment in water before the dyeing treatment.

The stretching of the polyvinyl alcohol-based resin film may be performed before, during, or after the dipping treatment of the dichroic dye in the aqueous solution. Stretching is usually uniaxial stretching.

The method of uniaxial stretching is not particularly limited, and may be any of wet stretching and dry stretching. The stretching ratio is usually 4 times or more, preferably 8 times or less. To uniaxially stretch a polyvinyl alcohol-based resin film in a dry manner in the same manner as usual, for example, a method in which a film is brought into contact with a heating roll driven while applying backward tension to orientate the film uniaxially vertically, and passed between a pair of heating rolls. Compression stretching. The temperature of the heating roll is equal to or higher than the glass transition temperature of the polyvinyl alcohol-based resin and equal to or lower than 160 ° C,
Preferably it is about 80 to 130 ° C.

As described above, the dichroic dye is dyed and oriented on the polyvinyl alcohol-based resin film, and the polyvinyl alcohol-based resin film to which the dichroic dye has been dyed is usually subjected to boric acid treatment.

The boric acid treatment is carried out by immersion in a boric acid-containing aqueous solution. The concentration of boric acid in the boric acid-containing aqueous solution is not particularly limited, but is usually about 2 to 15 parts by weight, preferably about 5 parts by weight, per 100 parts by weight of water. About 12 parts by weight. The temperature of the aqueous solution containing boric acid is usually 70 to 85.
° C, preferably about 70 to 80 ° C. The processing time is not particularly limited, but is usually about 100 to 1200 seconds, preferably about 150 to 600 seconds.

After the boric acid treatment, the film is washed and dried in the same manner as usual to obtain the polarizing film of the present invention.

Such a polarizing film is usually used by attaching a protective plate to one or both surfaces thereof. Such protective plates are the same as those used for ordinary polarizing plates, such as cellulose acetate films, acrylic films, polyester films, polyolefin films, polycarbonate films, polyarylate films, and polyethersulfone films. Etc. can be used. Examples of the cellulose acetate-based film include a triacetyl cellulose film, a diacetyl cellulose film and the like. The thickness of the protective plate is not particularly limited, but is usually 50 to 200 μm.
m. These protective plates may contain an ultraviolet absorber or the like, and such protective plates may be commercially available products, such as Konica KC80UVSF (manufactured by Konica Corporation) or Konica KC80UVN as a triacetyl cellulose film. (Manufactured by Konica Corporation).

The polarizing plate applied to the projection type liquid crystal display device of the present invention may be a commercially available polarizing plate.
Such commercially available polarizing plates include, for example, Sumitomo Chemical
"Sumikaran SW grade" manufactured by K.K.

Such a polarizing plate is most suitable for a projection type liquid crystal display device. The polarizing plate is bonded to a liquid crystal panel used for a line through which green light passes, or a glass, for example, whose surface is subjected to anti-reflection (AR) treatment. Attached to AR glass, dichroic coated glass, trimming filter, surface AR treated lens, surface dichroic treated lens, dichroic prism, etc., and installed near the liquid crystal panel, it is used in a projection type liquid crystal display device You. Further, a birefringent film or sheet such as a retardation plate or a viewing angle widening film may be bonded to the polarizing plate.

[0044]

According to the projection type liquid crystal display device of the present invention,
Compared with a conventional projection type liquid crystal display device, brightness and contrast are improved by natural color display, and an image displayed by the projection type liquid crystal display device is bright, and a clear screen can be displayed.

[0045]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. The transmittance at a wavelength of 520 nm to 570 nm for linearly polarized incident light parallel to the absorption axis direction of the polarizing film and the transmittance at a wavelength of 520 nm to 570 nm for linearly polarized incident light parallel to the transmission axis direction of the polarizing film are Shimadzu. The measurement was performed using a spectrophotometer UV2200 manufactured by Seisakusho.

Example 1 A commercially available polarizing plate ["Sumikaran SWW832A-HC-A"
R ", manufactured by Sumitomo Chemical Co., Ltd.] has a wavelength of 52 when irradiated with linearly polarized light having a vibration plane parallel to its absorption axis.
The transmittance in the range of 0 to 570 nm was 0.1% or less. In addition, the transmittance in a wavelength range of 520 to 570 nm upon irradiation with linearly polarized light having a vibration plane orthogonal to the absorption axis was 83% or more. 1 and 2 show transmission spectra of this polarizing plate. 1 and 2, the horizontal axis represents the wavelength (nm) of the transmitted light, and the vertical axis represents the transmittance (%).

The above-mentioned polarizing plate was bonded to a dichroic-coated lens and a prism on a line through which green light of a projection type liquid crystal display device (liquid crystal projector) was transmitted, and was disposed before and after a liquid crystal panel for green. The LCD projector has a bright and sharp display.

[Brief description of the drawings]

FIG. 1 is a diagram showing a light transmission spectrum of linearly polarized light having a vibration plane parallel to an absorption axis direction of a polarizing plate used in Example 1 with respect to incident light.

FIG. 2 is a diagram showing a light transmission spectrum of linearly polarized light perpendicular to the absorption axis direction of the polarizing plate used in Example 1 with respect to incident light.

Claims (1)

[Claims] A wavelength of 520 nm when linearly polarized light having a vibration plane parallel to the absorption axis direction of a polarizing plate is incident.
A wavelength of 520 nm to 570 nm when linearly polarized light having a transmittance at 570 nm of 0.1% or less and having a vibration plane orthogonal to the absorption axis direction of the polarizing plate is incident.
A projection type liquid crystal display device incorporating a polarizing plate having a transmittance of 83% or more.