JPH10293299A - Liquid crystal display device and production of dichromatic dyestuff-containing sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve dependence on visual angles and to provide the liquid crystal panel with a wide range of visual angles by providing the surface light source side of a liquid crystal panel with a dichromatic dyestuff-contg. sheet oriented in the major axis direction of dichromatic dyestuff malecules to the direction perpendicular to the liquid crystal panel. SOLUTION: Coloring occurs at the diagonal visual angle simply when the liquid crystal panel is provided with a phase difference film 108 and, therefore, the surface light source 101 side of a polarizing plate 103 is provided with the dichromatic dyestuff- contg. sheet 102a. The dichromatic dyestuff-contg. sheet 102a is so formed that the major axis of the bar-shaped dichromatic dyestuff molecules face a normal direction. The method of perpendicularly orienting the dichromatic dyestuffs is executed first by applying a perpendicularly orienting agent on a transparent substrate, for example, triacetyl cellulose film and baking the same. A liquid mixture composed of the dichromatic dyestuffs, nematic liquid crystals and UV curing resin is applied on the perpendicularly orienting agent and is cured by irradiation with UV rays. The dichromatic dyestuffs dissolved in the nematic liquid crystal are oriented in their molecular major axis in the normal direction by the perpendicularly oriented film and are cured in this state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device having a wide viewing angle with improved viewing angle dependency.

[0002]

2. Description of the Related Art A liquid crystal display device is a display element represented by a flat panel display, and is lightweight, thin, and consumes low power. Therefore, a monitor for an OA device, an in-vehicle television, a car navigation, and a video camera is used. Has been widely used.

[0003] Among them, it is important that the in-vehicle television, the car navigation, and the like can be seen well even from an oblique viewpoint from the positional relationship with the driver's viewpoint. However, a major problem of the liquid crystal display device is that the viewing angle is greatly dependent. The viewing angle dependence means that, for example, when viewed from an oblique direction at a certain angle or more, what should be originally displayed in black looks whitish or the gradation is inverted, so that the display content cannot be read correctly by the observer. . Therefore, there is a demand for a liquid crystal display device in which black display is not whitish in any direction and gradation characteristics are not lost.

FIG. 5 is a partial cross-sectional view showing the configuration of a conventional general liquid crystal display device which is not provided with a wide viewing angle means. The liquid crystal display device shown in FIG.
And a liquid crystal panel 210 and polarizing plates 203 and 209 arranged on both sides of the liquid crystal panel 210. The surface light source 201 includes a cold cathode fluorescent lamp and a light guide plate. The liquid crystal panel 210 is composed of thin film transistors (T
FT) and an active matrix substrate 204 on which transparent pixel electrodes are arranged, a twisted nematic (TN) liquid crystal 205, a color filter substrate 207 on which a transparent common electrode and a color filter are formed, and both substrates 204 and 207 are adhered and the liquid crystal is sealed. The liquid crystal panel 210 is composed of a sealing agent 206 that stops the liquid crystal panel 210 and the polarizing plates 203 and 209 with their transmission axes shifted by 90 ° (in the case of a normally white mode).
Is sandwiched between.

In the liquid crystal display device having the above-mentioned structure, a constant voltage is applied to the common electrode on the color filter substrate 207 and a constant voltage is applied to the transparent pixel electrode on the active matrix substrate 204 according to pixel data to be displayed. A voltage is applied. As a result, the twisted state of the liquid crystal between the two electrodes is changed according to the applied voltage, the transmittance of light passing through each pixel electrode portion is changed in combination with the polarizing plates 203 and 209, and light and dark are displayed.

However, since the properties of the liquid crystal used in the liquid crystal display device have birefringence, when the viewing angle is increased, the inversion of the gradation and the decrease of the contrast ratio occur, and the display quality is remarkably deteriorated. For example, in the above-mentioned general liquid crystal display device, a grayscale inversion occurs when the angle exceeds 5 ° in the downward direction, and the contrast ratio decreases to 10 or less when the angle exceeds 30 ° above and 50 ° below. Here, the grayscale inversion means that the original grayscale order recognized from the front is reversed when viewed from a certain oblique direction, and the contrast ratio is white display luminance / black display luminance.

The liquid crystal display device described in the above description is of a TN mode in which the twist angle of the liquid crystal is twisted by about 90 °. In other general liquid crystal display devices, an STN mode (Supe) in which the twist of the liquid crystal is twisted by 180 ° or more.
r Twisted Nematic). STN
The mode is a liquid crystal display device using birefringence of liquid crystal. In this mode, inversion of gradation and reduction in contrast occur.

There are various methods for improving the viewing angle dependency of this type of liquid crystal display device.
PS (In Plane Switching) method,
Examples include a phase difference plate method.

The alignment division method is a method in which two or more regions having different liquid crystal molecule alignment directions are provided, characteristics in oblique directions are averaged, and gradation inversion is suppressed. In this method, since the number of processes increases, the throughput and the yield decrease.

[0010] The IPS system is a method in which an electric field is applied in parallel with a substrate to control liquid crystal molecules to block and transmit light.
Utilizes birefringence of liquid crystal. Good display can be obtained from any angle without gradation inversion. However, since the signal electrode and the common electrode are provided in a comb shape on the same substrate, the aperture ratio is reduced and the display becomes dark. Therefore, the amount of light of the backlight must be increased, which is contrary to the low power consumption required for the liquid crystal display device.

The phase difference plate system obtains a display with a wide viewing angle by compensating for the phase difference of light transmitted through the liquid crystal. Since the retardation plate can be bonded simultaneously with the polarizing plate in the polarizing plate bonding step, the process does not need to be changed, and the transmittance is almost the same as that without the retardation plate. It is an effective method for improvement. Two conventional techniques of this retardation plate method will be introduced.

FIG. 6 is a block diagram of a viewing angle improving liquid crystal display device proposed in Japanese Patent Application Laid-Open No. 7-159614 (hereinafter, this is referred to as a first conventional technology). The principle of the viewing angle dependence improvement will be described. The liquid crystal display device shown in FIG. 6 has a configuration in which a liquid crystal cell CE and an optically anisotropic element RF are sandwiched between polarizing plates A and B. In FIG. 6, the polarization of light obliquely incident on the liquid crystal cell CE is shown in FIG. The state is shown.

First, when the incident light L0 is incident on the polarizing plate A, the polarization state becomes substantially linearly polarized light L1. Linear polarized light L1
When transmitted through the liquid crystal cell CE, the light becomes elliptically polarized light L2 due to the refractive index anisotropy of the liquid crystal. Proceeding as it is, the elliptically polarized light L2
Since light leakage occurs without being blocked by the polarizing plate B, the phase difference is compensated using the optically anisotropic element RF. When the light passes through the optically anisotropic element RF, the elliptically polarized light is modulated into the original linearly polarized light L3 by the phase delay effect. Therefore, the same transmittance is obtained even at oblique incidence, and a liquid crystal display device that is not dependent on the viewing angle is obtained.

Here, the optically anisotropic element used has an optically negative uniaxial property, and when the refractive indices in the three axial directions are nα, nβ, and nγ in ascending order, nα <nβ =
There is a relationship of nγ. Therefore, it has the characteristic that the refractive index in the optical axis direction is the smallest. Further, the film has no optical axis in the film plane nor in the normal direction.

However, in a liquid crystal display device using the present technology, coloring in an oblique direction, for example, yellow coloring occurs. This is because the negative refractive index distribution of the optical anisotropic element RF and the symmetry of the positive refractive index distribution of the liquid crystal cell CE are broken, and the wavelength dependence of the refractive index of the optical anisotropic element RF. .

FIG. 7 is a cross-sectional view of a viewing angle improving liquid crystal display device proposed in Japanese Patent Application Laid-Open No. Hei 2-302721 (hereinafter referred to as a second prior art). The liquid crystal display device shown in FIG. 7 includes a first substrate 1, a second substrate 2, a conductive electrode 3,
4, a liquid crystal cell comprising an alignment layer 5, 6, a sealing agent 7, and a nematic liquid crystal 8. The first retardation plate 11 and the second retardation plate 12 are replaced with the first polarizing plate 9 and the second polarizing plate 13. The structure is sandwiched between.

In FIG. 7, first and second retardation plates 11,
A stretched polyvinyl alcohol is used for 12, and in particular, a dichroic dye is added to the second retardation plate 12 so as to be oriented in the stretching direction of the film. The major axis direction of the dichroic dye molecules is parallel to the stretching direction and perpendicular to the normal direction of the second retardation plate 12. When this second retardation plate 12 is observed in the stretching direction of the film, light has a large component that vibrates in the molecular minor axis direction of the dichroic dye, and absorbs less light. When observed, light vibrates in the direction of the molecular long axis of the dichroic dye, and has a property of absorbing a predetermined wavelength. First and two phase difference plates 11,
The liquid crystal display device having a wide viewing angle range is obtained by performing phase compensation by using the liquid crystal display device 12, and the second retardation plate 12 corrects development in which coloring is performed as the viewing angle direction is inclined from the normal direction to the horizontal direction.

However, since the dichroic dye added to the second retardation plate 12 is oriented in one direction by stretching, even if the coloring in the oblique direction can be corrected, the absorption of the dichroic dye does not increase. However, it happens, and coloring occurs on the front.

[0019]

However, the conventional liquid crystal display device shown in FIG.
Retardation (the difference Δn (= ne−no) between the refractive index ne of the extraordinary light and the refractive index no of the ordinary light as the deviation from the normal to 10
And the liquid crystal cell gap d), the gradation is lost, the contrast ratio is lowered, and a display with a wide viewing angle cannot be obtained. Further, although not shown in the figure, there was a gradation inversion and a decrease in the contrast ratio even in the STN mode.

The first prior art, which is a proposal for improving the viewing angle dependency using the optically anisotropic element shown in FIG. 6, has the disadvantage that coloring is caused when used in a liquid crystal display device even if the contrast is suppressed. Was.

In the second prior art, which is a proposal for improving the viewing angle dependency using the retardation plate shown in FIG. 7, even if the coloring in the oblique direction can be corrected, the dichroism added to the retardation plate Since the orientation direction of the dye is parallel to the plane of the retardation plate, there is a problem that coloring occurs on the front.

As described above, when the retardation plate is used, if the viewing angle is widened, coloring occurs. If the coloring is suppressed, coloring occurs at other viewing angles. An object of the retardation plate method is to obtain a liquid crystal display device having a wide viewing angle without coloring in any direction.

An object of the present invention is to provide a liquid crystal display device which can solve coloration and has excellent display quality.

[0024]

To achieve the above object, a liquid crystal display according to the present invention comprises a liquid crystal display having a liquid crystal panel, a polarizing means, an optically anisotropic element, and a dichroic dye-containing sheet. A liquid crystal panel, comprising: a pair of glass substrates having a transparent conductive film electrode formed on the inner surface side thereof opposed to each other with a gap therebetween; and a liquid crystal injected into the gap. Are disposed on the surface light source side and the display surface side of the liquid crystal panel, respectively, and the optically anisotropic element is provided on one or both sides of the liquid crystal panel. The chromatic dye-containing sheet is provided on the surface light source side of the liquid crystal panel, and the long axis direction of the dichroic dye molecules is oriented in a direction perpendicular to the liquid crystal panel.

Further, a liquid crystal display device according to the present invention is a liquid crystal display device having a liquid crystal panel, a polarizing means, an optically anisotropic element, and a dichroic dye-containing sheet. A pair of glass substrates having a transparent conductive film electrode formed on the inner surface side thereof opposed to each other, and liquid crystal injected into the gap, wherein the polarizing means includes a surface light source side and a display surface of the liquid crystal panel. And the optically anisotropic element is provided on any one side of the liquid crystal panel, or on both sides, and the dichroic dye-containing sheet is provided on the surface of the liquid crystal panel. A liquid crystal display device provided on a light source side, wherein the dichroic dye molecule major axis directions are different from each other in such a manner that the dichroic dye molecule major axis directions are inclined with respect to the normal direction of the liquid crystal panel.

The method for producing a dichroic dye-containing sheet according to the present invention includes an alignment agent application step, a baking step, a mixed liquid application step, and a curing step, and is used for a liquid crystal display device. In the method for producing a containing sheet, the aligning agent applying step is a step of applying a vertical aligning agent on a transparent substrate or a polarizing plate, and the baking step is performed on the transparent film or the polarizing plate. It is a process of firing the alignment agent, the mixed solution coating step is at least a dichroic dye,
This is a process of applying a liquid mixture of a nematic liquid crystal or a polymer liquid crystal, and an ultraviolet curable resin on the vertical alignment agent, and the curing step is a process of curing the liquid mixture with ultraviolet light.

Further, the method for producing a dichroic dye-containing sheet according to the present invention includes a mixed liquid application step and a curing step,
A method for producing a dichroic dye-containing sheet for use in a liquid crystal display device, wherein the mixed liquid coating step includes, at least, mixing a dichroic dye, a nematic liquid crystal or a polymer liquid crystal, and a liquid mixture of an ultraviolet curable resin on a transparent substrate or a polarized light. The curing process is a process of applying the electric field or the magnetic field perpendicularly or obliquely to the transparent substrate surface or the polarizing plate surface, and curing the mixed liquid with ultraviolet rays.

Further, a photopolymerization initiator is added to the mixture.

The weight percentage of the dichroic dye is from 0.1 to
It is set to 4.0% by weight, preferably 0.5 to 1.5% by weight.

The weight% of the ultraviolet curing resin is 85%.
The weight is set to not less than 97% by weight, preferably not less than 90% by weight and not more than 95% by weight.

The curing step is performed in a nitrogen atmosphere.

[0032]

In the dichroic dye-containing sheet, the dichroic dye molecules are oriented parallel to or inclined from the normal direction of the liquid crystal display device. When light travels in the major axis direction, it vibrates in the short axis direction and travels, so there is no light absorption. When it travels in the short axis direction, it vibrates in the long axis direction, so there is light absorption. The short-axis direction of the dichroic dye molecules should be aligned as much as possible with the colored direction of the liquid crystal display device provided with the optically anisotropic element, and the wavelength component absorbed by the dichroic dye molecules should be optically anisotropic. By using the same components as those in the oblique direction of the liquid crystal display device provided with the element, a wide viewing angle liquid crystal display device in which coloring is suppressed can be obtained.

[0033]

Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1 FIG. 1 is a partial sectional view of a liquid crystal display device according to Embodiment 1 of the present invention.

The liquid crystal display device according to the first embodiment of the present invention shown in FIG. 1 includes a surface light source 101, a liquid crystal panel 110, polarizing plates 103 and 109, a retardation film 108, and a dichroic dye-containing sheet 102a. And

The surface light source 101 includes a cold cathode fluorescent lamp,
It is composed of a light guide plate or the like for making the surface of the light from the cold cathode fluorescent lamp uniform. Also, the liquid crystal panel 110
An active matrix substrate 104 in which thin-film transistors (TFTs) and transparent pixel electrodes are arranged in a matrix on a transparent glass substrate, a twisted nematic (TN) liquid crystal 105 having a twist angle of approximately 90 °, a transparent common electrode and a color filter Are formed, and a sealant 106 for bonding the two substrates 104 and 107 together and sealing the liquid crystal.
The retardation film 108 is provided between the color filter substrate 107 and the polarizing plate 109. Polarizing plate 103, 1
09 denotes a case where the transmission axis is shifted by 90 ° (in the case of the normally white mode) and the liquid crystal panel 110 and the retardation film 10 are shifted.
8 is sandwiched. The dichroic dye-containing sheet 102a is provided on the surface of the polarizing plate 103 on the surface light source 101 side.

The operation of the liquid crystal display according to the first embodiment of the present invention will be described. In FIG. 1, a description will first be given from a state where the dichroic dye-containing sheet 102 a is removed. Surface light source 101
When the light emitted from the liquid crystal panel 110 is transmitted through the liquid crystal panel 110, the more the light deviates from the normal line, the more the birefringence of the TN liquid crystal 105 causes the phenomenon that the black display floats (brightens).

In the first embodiment of the present invention, a negative uniaxial retardation film 108 having the opposite characteristic is provided for the optically positive uniaxial TN liquid crystal 105 which causes the above-described phenomenon. This compensates for the phenomenon that the black display floats. Here, the retardation film 108 described
For example, a WV film (manufactured by Fuji Photo Film Co., Ltd.) can be used. In addition, it may be combined with one having biaxiality or one having positive uniaxiality.

Next, the state in which the dichroic dye-containing sheet 102a is provided will be described. Simply by providing the retardation film 108, coloring occurs at an oblique viewing angle. Therefore, the dichroic dye-containing sheet 102a is provided on the polarizing plate 103 on the surface light source side. The dichroic dye-containing sheet 102a will be described in detail.

FIG. 2 is a partially enlarged view of the dichroic dye-containing sheet 102a. As shown in FIG. 2, the dichroic dye-containing sheet 102a is formed such that the long axis of the rod-like dichroic dye molecules 111a is oriented in the normal direction. The light traveling in the normal direction is light that oscillates in the short axis direction, and thus does not absorb light. However, the component that oscillates in the long axis direction becomes larger as the direction becomes oblique, and the light absorption becomes larger. With only the retardation film 108, the upper left and upper right directions are colored dark yellow, and the left and right directions are colored light yellow. Therefore, the dichroic dye of the dichroic dye-containing sheet 102a is set to a complementary color blue. As a result, coloring does not occur on the front surface, and coloring in an oblique direction can be suppressed.

A method for vertically orienting the dichroic dye in the dichroic dye-containing sheet has not existed conventionally. However, in the present invention, the dichroic dye in the dichroic dye-containing sheet is obtained by the following method. Are oriented vertically.

First, a vertical alignment agent is applied to a transparent substrate, for example, a triacetyl cellulose film, and baked. As the vertical alignment agent, for example, SE-7511L (manufactured by Nissan Chemical Industries, Ltd.) can be used.

A mixture of a dichroic dye, a nematic liquid crystal, and an ultraviolet curable resin is applied on the vertical alignment agent, and the mixture is cured by irradiation with ultraviolet rays. The dichroic dye dissolved in the nematic liquid crystal has its molecular major axis oriented in the normal direction by the vertical alignment film, and is cured in that state.

The weight percentage of the dichroic dye may be 0.1 to 4.0% by weight, preferably 0.5 to 1.5% by weight. As the nematic liquid crystal, any liquid crystal such as cyano-based, fluorine-based, and chlorine-based can be used, but a liquid crystal having high solubility in a dichroic dye is preferable. Further, a polymer liquid crystal can be used instead of a nematic liquid crystal. The UV-curable resin may be a monofunctional acrylate compound, a monofunctional methacrylate compound, a polyfunctional acrylate compound, a polyfunctional methacrylate compound, or the like, and may be used alone or in a copolymer of two or more types. it can.

If the amount by weight of the UV-curable resin is too large, the order of orientation of the liquid crystal and the dichroic dye becomes low, and coloring occurs in the normal direction. If the amount is too small, the liquid crystal seeps out. In addition, the effect of maintaining the alignment between the liquid crystal and the dichroic dye is so weak that it cannot be used for a long time. Therefore,
85% to 97% by weight, preferably 90% by weight
It is preferably at least 95% by weight. It is difficult to cure the ultraviolet curing resin alone, so it is preferable to add a photopolymerization initiator. As the photopolymerization initiator, thioxanthone, diazonium chlorine, sulfonium chlorine, iodonium chlorine, selenium chlorine and the like can be used. The initiator concentration is preferably 30% by weight or less of the ultraviolet curable resin. Further, when curing, it is easier to solidify under a nitrogen atmosphere.

As a method of vertically aligning the dichroic dye, a method of applying an electric field and a magnetic field to the transparent substrate vertically may be used instead of using the vertical alignment film. Further, the substrate on which the dichroic dye mixture is applied is not a transparent substrate, but a polarizing plate 103 may be used as the substrate.

As described above, Embodiment 1 of the present invention
In the liquid crystal display device, by adding an optically anisotropic element and a dichroic dye-containing sheet in which the dichroic dye molecule major axis direction is oriented perpendicular to the liquid crystal panel, without impairing the front color tone Thus, a wide viewing angle display in which coloring in the upper left, upper right, and left and right oblique directions is suppressed can be obtained.

Embodiment 2 FIG. 3 is a partial sectional view of a liquid crystal display device according to Embodiment 2 of the present invention.

Embodiment 1 of the present invention shown in FIGS. 1 and 2
Focuses on improving the oblique yellow coloring of a liquid crystal display device using a retardation film. However, blue coloring is actually occurring in the downward direction. In the first embodiment, when the dichroic dye is changed to blue, which is a complementary color of yellow, a display in which blue is enhanced in the downward direction is obtained. OA terminals rarely see from the bottom, but in-vehicle televisions and monitors for video cameras are viewed from all directions, so the downward blue color is a problem.

This phenomenon can be suppressed by the second embodiment of the present invention.

In Embodiment 2 of the present invention shown in FIG. 3, the dichroic dye-containing sheet 1 is provided on the surface light source 101 side of the liquid crystal panel 110.
02b, 202c, 102d, and 102e.

The sheet containing the dichroic dye used in FIG.
It will be described based on. FIG. 4A shows the orientation directions of the dichroic dye molecules 111b, 111c, 111d, and 111e in the dichroic dye-containing sheets 102b, 102c, 102d, and 102e. According to the normal direction of the liquid crystal panel 110, the dichroic dye molecule 111b is θ _{1 in} the upper left direction, the dichroic dye molecule 111c is θ _{2 in} the lower left direction, and the dichroic dye molecule 1 is
11d is formed so as to be inclined at an upper right direction θ ₃ and the dichroic dye molecule 111e is inclined at a lower right direction θ ₄ . θ _{1 to} θ ₄ are each 20 to 70 degrees, preferably 30 to 60 degrees.

FIG. 4B shows the orientation of the dichroic dye molecules 111b, 111c, 111d and 111e as viewed from the front. phi ₁ to [phi] ₄ represents the inclination (azimuth) from the left and right direction on the sheet surface. φ _{1 to} φ ₄ are each 20 to 70 degrees, preferably 30 to 60 degrees.

In order to suppress the above-mentioned coloring in the oblique direction, the dichroic dye molecules 111b and 111d are colored yellow, and the dichroic dye molecules 111c and 111e are colored blue. Adjust the amount of the coloring pigment.

Light traveling in the upper left direction is composed of blue dichroic dye molecules 111e and 111c and yellow dichroic dye molecules 111d.
Mainly vibrates in the long axis direction, and the yellow dichroic dye molecule 111
Vibrates mainly in the short axis direction of b. As a result, the colors of the yellow dichroic dye molecules 111b and the blue dichroic dye molecules 111c are almost canceled, and the blue dichroic dye molecules 1
11e causes coloring. The same applies to the upper right direction.

Light traveling in the downward direction mainly oscillates in the short axis direction of the blue dichroic dye molecules 111c and 111e, and mainly oscillates in the long axis direction of the yellow dichroic dye molecules 111b and 111d. Turns yellow. These colors are complementary to the coloring of the liquid crystal display device using the retardation film 108, the yellow color in the upper left direction, the yellow color in the upper right direction, and the blue color in the lower direction, so that coloring can be suppressed.

The number of the dichroic dye-containing sheets is as described above.
It is not limited to color combinations and dichroic dye orientation directions. The number, combination of colors, θ, and φ can be set freely for any liquid crystal display device in which coloring occurs in an oblique direction.

The dichroic dye can be oriented obliquely by, for example, applying an electric field or a magnetic field obliquely to a sheet coated with a mixture of a dichroic dye, a nematic liquid crystal, and an ultraviolet curable resin.
It is cured by irradiation with ultraviolet rays. Materials, mixing ratios, curing conditions, and the like are the same as those in the first embodiment of the present invention.

As described above, Embodiment 2 of the present invention
In the liquid crystal display device according to the optical anisotropic element, by adding two or more sheets of dichroic dye-containing sheet, the long axis direction of the dichroic dye molecules is oriented to be inclined from the normal direction of the liquid crystal panel,
Coloring in the upper left, upper right, and lower diagonal directions can be suppressed,
A wide viewing angle display is obtained. Furthermore, compared to the first embodiment,
Since the number of dichroic dye-containing sheets and the orientation direction of the dichroic dye molecules can be arbitrarily set, in addition to the coloring phenomenon described in Embodiment 2, coloring in various directions can be suppressed, and the degree of freedom can be reduced. Can be enhanced.

[0060]

As described above, according to the present invention, discomfort is given to applications that require clear reading of details from various directions, such as a map display, such as a car navigation display. Without this, the displayed contents can be easily recognized and applied.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is a partially enlarged view of a dichroic dye-containing sheet according to the first embodiment of the present invention.

FIG. 3 is a partial cross-sectional view of a liquid crystal display device according to Embodiment 2 of the present invention.

FIG. 4 is a diagram illustrating the orientation direction of dichroic dye molecules according to Embodiment 2 of the present invention.

FIG. 5 is a partial sectional view of a conventional liquid crystal display device.

FIG. 6 is a configuration diagram illustrating a liquid crystal display device according to a first related art.

FIG. 7 is a configuration diagram illustrating a liquid crystal display device according to a second related art.

[Explanation of symbols]

101 surface light source 102a, 102b, 102c, 102d, 102e
Dichroic dye-containing sheet 103, 109 Polarizer 104 Active matrix substrate 105 TN liquid crystal 107 Color filter substrate 106 Sealant 108 Retardation film 110 Liquid crystal panel 111a, 111b, 111c, 111d, 111e
Dichroic dye molecule

Claims (8)

[Claims] 1. A liquid crystal display device comprising a liquid crystal panel, a polarizing means, an optically anisotropic element, and a dichroic dye-containing sheet, wherein the liquid crystal panels are arranged to face each other via a gap and are transparent on an inner surface side. The liquid crystal panel includes a pair of glass substrates on which a conductive film electrode is formed, and liquid crystal injected into the gap. The polarizing unit is disposed on a surface light source side and a display surface side of the liquid crystal panel, respectively. The optically anisotropic element is provided on any one side or both sides of the liquid crystal panel, and the dichroic dye-containing sheet is provided on the surface light source side of the liquid crystal panel. A liquid crystal display device, wherein the major axis direction of the coloring matter molecules is oriented in a direction perpendicular to the liquid crystal panel. 2. A liquid crystal display device comprising a liquid crystal panel, a polarizing means, an optically anisotropic element, and a dichroic dye-containing sheet, wherein the liquid crystal panels are arranged to face each other via a gap and are transparent on the inner surface side. The liquid crystal panel includes a pair of glass substrates on which a conductive film electrode is formed, and liquid crystal injected into the gap. The polarizing unit is disposed on a surface light source side and a display surface side of the liquid crystal panel, respectively. The optically anisotropic element is provided on one side or both sides of the liquid crystal panel. A plurality of dichroic dye-containing sheets are provided on the surface light source side of the liquid crystal panel. A liquid crystal display device wherein the major axis directions of the chromatic dye molecules are oriented differently from the normal direction of the liquid crystal panel and are different from each other. 3. A method for producing a dichroic dye-containing sheet for use in a liquid crystal display device, comprising a step of applying an alignment agent, a step of baking, a step of applying a mixed liquid, and a step of curing. A process of applying a vertical alignment agent on a transparent substrate or a polarizing plate. The firing step is a process of firing the vertical alignment agent applied on a transparent film or a polarizing plate. Is a process of applying a mixture of at least a dichroic dye, a nematic liquid crystal or a polymer liquid crystal, and an ultraviolet curable resin onto the vertical alignment agent, and the curing step is a process of curing the mixture with ultraviolet light. A method for producing a dichroic dye-containing sheet, comprising: 4. A method comprising a mixed liquid application step and a curing step,
A method for producing a dichroic dye-containing sheet for use in a liquid crystal display device, wherein the mixed liquid coating step includes, at least, mixing a dichroic dye, a nematic liquid crystal or a polymer liquid crystal, and a liquid mixture of an ultraviolet curable resin on a transparent substrate or polarizing light. The curing process is a process of curing the mixture with ultraviolet rays while applying an electric field or a magnetic field perpendicularly or obliquely to the transparent substrate surface or the polarizing plate surface. A method for producing a dichroic dye-containing sheet. 5. The method for producing a dichroic dye-containing sheet according to claim 3, wherein a photopolymerization initiator is added to the liquid mixture. 6. The weight percentage of the dichroic dye is from 0.1 to 0.1.
The method for producing a dichroic dye-containing sheet according to claim 3 or 4, wherein the content is set to 4.0% by weight, preferably 0.5 to 1.5% by weight. 7. The ultraviolet curing resin has a weight percentage of 85% to 97% by weight, preferably 90% to 9% by weight.
5. The method for producing a dichroic dye-containing sheet according to claim 3, wherein the content is set to 5% by weight or less. 8. The method for producing a dichroic dye-containing sheet according to claim 3, wherein the curing step is performed in a nitrogen atmosphere.