JPH0836172A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To realize a color liquid crystal display device with low energy consumption and bright display without requiring back light and a color filter. CONSTITUTION:Two transparent glass substrates 8A and 8B provided with transparent electrodes 9A and 9B and orienting films 10A and 10B, respectively, are laminated with a specified space. A liquid crystal layer 11 having a twisted structure in the thickness direction is sealed between the substrates 8A and 8B to obtain a liquid crystal display element 12. The device consists of this liquid crystal display element 12, a polarizing plate 7 applied on the outside of the substrate 8A where light enters, a light-absorbing sheet 6 applied on the outside of the substrate 8B in the opposite side, and a phase difference plate 1 in a striped shape formed on the substrate 8B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a method in which two transparent insulating substrates provided with a transparent electrode and an alignment film are superposed with a predetermined gap therebetween, and a liquid crystal twisted in the thickness direction is sealed between the two substrates. The present invention relates to a liquid crystal display device including a liquid crystal display element.

[0002]

2. Description of the Related Art In a conventional simple matrix type liquid crystal display device, two striped transparent electrodes, which extend perpendicularly to each other when viewed from a direction perpendicular to a display screen, are formed on two opposite surfaces, respectively. The transparent glass substrates are laminated with a predetermined gap therebetween, and the two substrates are bonded together by a sealing material provided in a frame shape at the edge between the two substrates, and the liquid crystal sealing port provided in a part of the sealing material. A liquid crystal display element (liquid crystal display panel) formed by enclosing and sealing liquid crystal inside the sealing material between both substrates, the liquid crystal being twisted in the thickness direction, and further providing a polarizing plate on the outside of both substrates A backlight arranged below the display element to supply light to the liquid crystal display element,
A drive circuit board disposed outside the outer peripheral portion of the liquid crystal display element, a frame-shaped body that is a molded product that holds each of these members, and each of these members are stored, and a liquid crystal display window is opened. When a voltage is applied to the transparent electrodes on both the upper and lower substrates, the liquid crystal part between the transparent electrodes responds to this voltage, and characters and figures are displayed.

By the way, there is a liquid crystal display device in which a retardation plate is placed over a liquid crystal display element in order to compensate for unnecessary coloration of the liquid crystal display screen and improve viewing angle characteristics. The retardation plate is manufactured by uniaxially stretching one or more kinds of organic polymer materials and forming a film. The retardation value of the retardation plate can be controlled by changing the degree of stretching, and the coloring is compensated by the effect of birefringence and the viewing angle characteristics are improved. The liquid crystal layer is 18
A technique using a retardation plate for color compensation of a liquid crystal display device which is twisted by 0 ° or more is described in, for example, Japanese Patent Laid-Open No. 13916/1993.

Conventionally, a color liquid crystal display device has a structure in which a color filter is formed on one of the substrates, a polarizing plate is installed on the outside of each of the substrates, and a backlight is provided as an auxiliary light source. . In such a liquid crystal display device, vivid multicolor display was possible by combining color filters having different transmission spectra, for example, a large number of colors such as red, green, blue, or cyan, magenta, and yellow. A liquid crystal display device having a color filter is
For example, it is described in JP-A-4-362919.

[0005]

Since the conventional liquid crystal display device has a backlight as an auxiliary light source, it is difficult to reduce power consumption. In order to reduce power consumption, there is a reflective color liquid crystal display device having a reflective plate on one substrate side, but one transparent glass substrate that constitutes a liquid crystal display element has a color filter, and the color filter is Since it absorbs light, the light transmittance is reduced, and furthermore, two polarizing plates are provided on each of the outer sides of both substrates.
Light has to pass through the polarizing plate four times in total, which causes a problem that the display in the bright state becomes very dark.

Further, in the conventional liquid crystal display device, since the thickness of the transparent electrodes formed in stripes on the substrate has nonuniformity, the thickness of the liquid crystal layer is disturbed, and the optical characteristics of the liquid crystal display device are disturbed. The product Δn · d of the difference in birefringence of the liquid crystal (refractive index anisotropy) Δn and the thickness of the liquid crystal layer (gap between both substrates) d, which is one of the variables that determine the characteristics, is not uniform. It was Furthermore, in a liquid crystal display device having a color filter or a black matrix of two or more colors formed in a stripe shape on a substrate, the presence of the color filter or the black matrix causes a disorder in the thickness of the liquid crystal layer, resulting in a stripe shape. Since Δn · d is different, it is difficult to optimize the optical characteristics. The retardation plate is used to compensate for the imbalance of the optical characteristics. However, the conventional retardation plate is produced by uniaxially stretching an organic polymer film, and thus has a plate shape with a substantially uniform thickness. Therefore, it is not possible to partially control the thickness of the retardation film or change the retardation in accordance with the matrix of the liquid crystal display element, and to control the thickness or partially adjust the retardation. It was difficult to change to.

A first object of the present invention is to provide a liquid crystal display device capable of achieving low power consumption and a bright display.

A second object of the present invention is to partially optically compensate the disturbance of Δn · d due to the nonuniformity of the film thickness of the transparent electrode, the color filter, the black matrix, etc. An object of the present invention is to provide a liquid crystal display device capable of optimizing the optical characteristics of elements.

[0009]

In order to solve the above-mentioned problems, the liquid crystal display device of the present invention has two transparent insulating substrates in such a manner that the surfaces provided with the transparent electrodes and the alignment film face each other. Liquid crystal twisted in the thickness direction between the two substrates inside the sealing material while the two substrates are bonded together by a sealing material provided in the shape of a frame around the edge between the two substrates. A liquid crystal display element, a polarizing plate provided outside the first substrate on the light incident side of the two substrates, and a light absorbing member provided outside the other second substrate. And a striped retardation film provided on at least one of the both substrates.

Further, in the liquid crystal display device of the present invention, two transparent insulating substrates are stacked with a predetermined gap so that the surfaces provided with the transparent electrodes and the alignment film face each other, and the two substrates are placed between the two substrates. A liquid crystal display element formed by bonding the both substrates with a sealing material provided in a frame shape around an edge and sealing a liquid crystal twisted in a thickness direction between the both substrates inside the sealing material, A liquid crystal display device comprising polarizing plates respectively provided on the outer sides of the substrates, characterized in that it has a striped retardation plate provided on at least one of the both substrates.

Further, in the liquid crystal display device of the present invention, two transparent insulating substrates are stacked with a predetermined gap so that the surfaces provided with the transparent electrodes and the alignment film face each other, and the two substrates are placed between the two substrates. A liquid crystal including a liquid crystal display element formed by bonding the two substrates with a sealing material provided in a frame shape around the edge and sealing a liquid crystal twisted in the thickness direction between the two substrates inside the sealing material. In the display device, at least one of the both substrates has a retardation plate patterned corresponding to at least one of a transparent electrode, a color filter, and a black matrix.

Further, the retardation plate is composed of a plurality of stripes different in at least one of thickness and birefringence.

The stripes are made of an organic polymer twisted in the thickness direction.

Further, the striped retardation plate does not have to actually have a striped shape, or may be a plate-shaped retardation plate having substantially the same thickness in terms of shape. May be a retardation plate having stripes. That is, for example, when the organic polymer layer is irradiated with ultraviolet light in a stripe shape, the irradiated portion has no phase difference. The retardation plate thus formed serves as a retardation plate in which the retardation occurs in a stripe shape, and has the same action and effect as the retardation plate formed in a stripe shape.

The refractive index of the liquid crystal in the parallel direction is approximately 1.5 to 1.6.

Further, the twist angle of the retardation plate is approximately 18
It is characterized in that it is 0 ° or more.

Further, the refractive index of the retardation plate in the vertical direction is approximately 1.6 to 2.1.

Further, the thickness of the striped retardation film is approximately 200 nm or more.

The twist angle of the liquid crystal is approximately 180 °.
It is characterized by the above.

Further, the stripe of the retardation film is formed on a surface of a substrate different from the transparent insulating substrate.

Further, the substrate is an organic polymer film and is a plate-shaped retardation plate having substantially the same thickness.

Further, the transparent electrodes of the both substrates are in the form of a plurality of stripes extending in the directions perpendicular to each other when viewed from the direction perpendicular to the surfaces of the substrates, and the liquid crystal display element is a simple matrix type. It is characterized by being.

Each stripe of the retardation film is formed along at least one of a transparent electrode, a color filter and a black matrix.

Further, at least one of the thickness and the birefringence of each stripe of the retardation film is controlled corresponding to at least one of the thickness of the transparent electrode, the color filter and the black matrix. To do.

Further, the reflection spectrum of bright display is set to a predetermined plurality of colors by at least one of the thickness and the birefringence of the stripes of the retardation plate, and one set is repeated with a predetermined number of the stripes. It is characterized in that it is formed and capable of color display (multicolor display).

Further, at least one plate-shaped retardation plate having substantially the same thickness is provided between the polarizing plate and the substrate.

Further, the liquid crystal display device is of an active matrix type.

[0028]

A liquid crystal display device comprising two transparent insulating substrates provided with a transparent electrode and an alignment film, which are superposed on each other with a predetermined gap therebetween, and liquid crystal twisted in the thickness direction is sealed between the two substrates. A polarizing plate provided outside the first substrate on the light incident side of the two substrates, a light absorbing member provided outside the other second substrate, and provided on at least one of the two substrates. In a liquid crystal display device having a structure including a striped retardation plate, as will be described later in detail with reference to FIG. 2 in an embodiment, in the bright state, natural light as a light source is linearized by a polarizing plate. The light that becomes polarized light and passes through the liquid crystal layer is
Circularly polarized light around the opposite direction of the twisting direction of the striped retardation plate. In this case, the light does not pass through the retardation plate, is reflected in the vicinity of the surface of the retardation plate, passes through the liquid crystal layer again, becomes linearly polarized light, and passes through the polarizing plate. On the other hand, in the display in the dark state, the light transmitted through the liquid crystal layer becomes circularly polarized light in the twisting direction of the retardation plate, that is, around the same direction, and after passing through the retardation plate, is absorbed by the light absorbing member. According to the present principle, by setting the polarizing plate, the liquid crystal layer, and the retardation plate, the maximum transmission wavelength of emitted light and dark display when voltage is applied by the power source can be displayed. That is, specific polarized light is reflected by the retardation plate, which is a stripe-shaped cholesteric layer twisted in the thickness direction, and color display can be performed by optimizing the conditions of the retardation plate. Therefore, an auxiliary light source such as a backlight is not required, and since the polarizing plate has conventionally been passed four times in total, it can be passed only twice.
It is possible to provide a liquid crystal display device that has a high light transmittance in a bright state and consumes less power and can perform multicolor display.

Further, in a liquid crystal display device having a structure including the liquid crystal display element, polarizing plates provided outside the both substrates, and a striped retardation plate provided on at least one of the both substrates. The partial optical compensation can be performed by the stripe-shaped retardation plate, and the optical characteristics of the liquid crystal display device can be optimized, that is, the contrast can be improved and the hue can be achromatic. That is, the stripes of the retardation film are formed along at least one of the transparent electrode, the color filter, and the black matrix, and by aligning these stripes, the irregularity of Δn · d caused by the nonuniformity of the thickness of the structure is formed. It becomes possible to compensate optically or optically. Further, by configuring the stripe-shaped retardation film with stripes having two or more types of thickness and different birefringence,
It can be compensated more effectively. In the active matrix type liquid crystal display device, the transparent electrodes, the color filters, and the black matrix are not patterned in a stripe shape unlike the simple matrix type. Therefore, a patterned retardation plate is used accordingly.

[0030]

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

Example 1 FIG. 1 is a partial sectional view of a liquid crystal display element of a simple matrix type liquid crystal display device of Example 1 of the present invention.

Reference numeral 7 is a polarizing plate, 8A and 8B are transparent insulating substrates,
For example, transparent glass substrates 9A and 9B are stripe-shaped transparent electrodes 10A and 10B that extend in mutually perpendicular directions when viewed from a direction perpendicular to the display screen (or the surfaces of the transparent glass substrates 8A and 8B). A film, 1 is a retardation plate according to the present invention, 6 is a light absorbing sheet, 11 is a liquid crystal layer, and 12 is a liquid crystal display element (liquid crystal display panel). In this embodiment,
The retardation plate 1 is formed in a stripe shape in the liquid crystal display element 12, that is, on the transparent glass substrate 8B on which the transparent electrode 9B is formed (via the transparent electrode 9B), and is twisted in the thickness direction. It is composed of a polymer layer. Also,
The light absorbing sheet 6 is made of, for example, black paper.

FIG. 2 is a diagram for explaining the display principle of the liquid crystal display element shown in FIG.

In the display in the bright state, natural light as a light source is linearly polarized by the polarizing plate 7, and light transmitted through the liquid crystal layer 11 is circularly polarized around the direction opposite to the twist direction of the retardation plate 1. In this case, the light does not pass through the retardation plate 1, is reflected in the vicinity of the surface of the retardation plate 1, passes through the liquid crystal layer 11 again, becomes linearly polarized light, and passes through the polarizing plate 7. On the other hand, in the display in the dark state, the light transmitted through the liquid crystal layer 11 becomes circularly polarized light in the twisting direction of the retardation plate 1, that is, circularly polarized light around the same direction, and after passing through the retardation plate 1, is absorbed by the light absorbing sheet 6. To be done. According to the present principle, by setting the polarizing plate 7, the liquid crystal layer 11, and the retardation plate 1, the maximum transmission wavelength of the emitted light, the power source 13
A dark display is possible when a voltage is applied. That is, the specific polarized light is reflected by the retardation plate 1 which is a stripe-shaped cholesteric layer twisted in the thickness direction, and color display can be realized by optimizing the conditions of the retardation plate 1.

In the liquid crystal display device of the present embodiment, stripes and intersects (when viewed from a direction perpendicular to the display screen or the surfaces of the transparent glass substrates 8A and 8B, not the actual intersections). The liquid crystal layers 11 in the intersecting portions (dot matrix) of the transparent electrodes 9A and 9B of both transparent glass substrates 8A and 8B are transparent electrodes 9A from the outside. , 9B, and a predetermined display is performed in response to the voltage applied to 9B. Therefore, by matching the stripe shape of the transparent electrode 9A or 9B with the stripe shape of the retardation film 1, the above display principle can be effectively utilized. That is, the reflectance can be improved by setting the twist angle of the retardation plate 1 to 180 ° or more. For example,
The refractive index of the liquid crystal in the parallel direction is 1.5 to 1.6, and the refractive index of the extraordinary light in the vertical direction of the retardation plate 1 is 1.6 to 2.
1. Further, by setting the thickness to 200 nm or more, multicolor display can be realized, and by forming the stripes of the retardation plate 1 having different refractive indexes, thicknesses, etc. on the transparent glass substrate 7B. The reflection spectrum of the reflected light of the liquid crystal display element 12 can be set to red, green, blue, or cyan, magenta, yellow, or the like. In addition, the liquid crystal layer 1
By setting the twist angle of 1 to 180 ° or more, the reflectance with respect to the applied voltage becomes steep, and time-division driving becomes possible. Further, the polarizing plate 7 and the transparent glass substrate 8A on the incident light side
By providing an organic polymer film, such as a conventional plate-shaped retarder or triacetyl cellulose film, which has almost the same thickness, between and, fine adjustment of the display color, improvement of viewing angle characteristics, or high It is possible to make contrast.

In the liquid crystal display device of this embodiment, based on the above display principle, it is possible to create a bright state with high reflectance without using an auxiliary light source such as a backlight, and the light transmittance in the bright state is high. , Color display is now possible.

As a method of forming the stripe retardation film 1 on the transparent glass substrate 8B, there are a printing method, a photolithography method, a mechanical cutting method and the like. In this embodiment, it is formed by a mechanical cutting method. The method of forming these will be described in detail at the end of the embodiment.

Embodiment 2 FIG. 3 is a sectional view of another embodiment of the retardation plate according to the present invention.

Reference numeral 1 denotes a retardation plate made of a stripe-shaped organic polymer layer, 4 a substrate made of transparent glass for forming the retardation plate 1, 3 an insulating film, 2 an insulating film 3 on which the retardation plate 1 is formed. It is an adhesive layer for bonding. That is, in the retardation plate 1 of this embodiment, a glass substrate is used as the substrate 4, an insulating film made of SiO ₂ or the like is formed, and then an organic polymer layer such as polycarbonate or polysulfone having a different thickness is formed in a stripe shape. did. By forming the insulating film 3, the glass substrate 4
It can be provided inside the liquid crystal display element while preventing the outflow of ions. When the glass substrate 4 has high purity and the glass substrate 4 and the organic polymer layer of the retardation plate 1 have good adhesion, the insulating film 3 and the adhesive layer 2 are not necessary.

Example 3 FIG. 4 is a partial cross-sectional view of a liquid crystal display element of Example 3 of the present invention.

In this embodiment, the stripe-shaped retardation plate 1 in which the organic polymer is twisted in the thickness direction is formed by the printing method described later in detail, and the flattening film 5 is formed thereon. The flattening film 5 is made of a transparent resin material such as acrylic resin or epoxy resin. The refractive index of extraordinary light with respect to the vertical direction of the retardation plate 1 is 1.6 to 2.1, the thickness of the retardation plate 1 is 200 nm or more, and the retardation plates are respectively twisted by 180 ° or more in the thickness direction. Composed of repeating stripes of different types.

FIG. 5 is a diagram showing the spectral reflectance in the bright state of the liquid crystal display element of the third embodiment.

Reference numeral 14 is a red spectral reflectance, 15 is a green spectral reflectance, and 16 is a blue spectral reflectance. In the liquid crystal display element of the present example, it was possible to set the reflection spectrum of the reflected light to red, green and blue, as is clear from FIG.

Example 4 FIG. 6 shows a conventional uniaxially stretchable retardation film having a liquid crystal layer 11 having a twist angle of 240 °, polycarbonate as a material, and Δn · d of 400 nm in the structure shown in FIG. FIG. 6 is a diagram showing the relationship between the effective voltage and the reflectance when is further provided between the transparent glass substrate 8A on the light incident side and the polarizing plate 7. By setting the twist angle of the liquid crystal layer 11 to 240 °, the steepness was improved, and a contrast ratio of 8: 1 was obtained by time-division driving.

According to the first, third and fourth embodiments, since no auxiliary light source such as a backlight is used, it is possible to provide a liquid crystal display device with low power consumption and bright display.

Example 5 FIG. 7 is a partial cross-sectional view of a liquid crystal display element of Example 5 of the present invention.

Reference numeral 7 is a polarizing plate, 1 is a striped retardation plate according to the present invention, 4 is a triacetyl cellulose film provided as a substrate of the striped retardation plate 1, 8
A and 8B are transparent glass substrates, 9A and 9B are striped transparent electrodes 10A and 10B that extend perpendicularly to each other when viewed from a direction perpendicular to the display screen (or the surfaces of the transparent glass substrates 8A and 8B). Alignment film, 11 is a liquid crystal layer, 12
Is a liquid crystal display device. In this embodiment, the striped retardation film 1 is formed by using the triacetyl cellulose film 4 as a substrate and is attached inside the liquid crystal display element 12, that is, on the surface of the transparent glass substrate 8A. As described above, conventionally, due to various factors (for example, the direction in which the etching solution flows when patterning the transparent electrode: the closer to the place where the etching solution flows, the thinner the substrate 8A or 8).
Since the transparent electrodes 9A and 9B formed in a stripe shape on B have nonuniformity, the thickness of the liquid crystal layer 11 is disturbed, which is one of the variables that determine the optical characteristics of the liquid crystal display device. A certain Δn · d was non-uniform. In this embodiment,
By aligning the stripe of the phase difference plate 1 with the transparent electrode 9B on one side, it is possible to compensate for the disturbance of Δn · d caused by the nonuniformity of the thickness of the transparent electrodes 9A and 9B. When it is fitted to both the transparent electrodes 9A and 9B, the two striped phase difference plates 1 are attached to the transparent glass substrate 8A,
8B each, or one transparent glass substrate 8
Two pieces are provided on either A or 8B. That is, the respective stripes of the two retardation films 1 extend in directions perpendicular to each other when viewed from a direction perpendicular to both substrate surfaces 8A and 8B. Further, one retardation plate 1 in a lattice shape in which stripes actually intersect may be provided.

When the retardation film 1 is formed of two or more kinds of birefringence or stripes having different thicknesses,
It is possible to more effectively compensate for the nonuniformity of the thickness of the transparent electrodes 9A and 9B. That is, the nonuniformity of the thickness of the transparent electrodes is measured and investigated in advance, and according to the result, stripes are formed corresponding to the nonuniformity of the thickness of both or one of the transparent electrodes 9A and 9B of both substrates 8A and 8B. The thickness and / or birefringence of each stripe of the rectangular retardation plate 1 are determined and formed.

Further, the thin film transistor (T
FT) is used as a switching element
It can also be applied to a matrix type liquid crystal display element. In this case, when the retardation plate according to the present invention is formed along with the transparent electrode, the retardation plate is formed so as to match the pattern of the transparent electrode.

Example 6 FIG. 8 is a partial cross-sectional view of a liquid crystal display element of Example 6 of the present invention.

This example is an example of a structure almost similar to that of Example 5. However, in this example, a triacetyl cellulose film is used as the substrate 4, and the organic polymer layer is striped via the adhesive layer 2. The retardation film 1 was formed by forming a film on the transparent glass substrate 8A. In this embodiment, as shown in FIG. 8, the stripe-shaped transparent electrodes 9B are formed.
Δn · d (d = dA and dB) of the liquid crystal is generated due to the nonuniformity of the thickness of the liquid crystal, but the optical characteristics are optimized by the striped retardation plate 1 formed on the transparent glass substrate 8A. . When the disturbance of Δn · d is large and optical compensation is required for the entire liquid crystal display element, a conventional plate-shaped retardation plate having substantially the same thickness is used as the substrate 4, and stripes are formed on the retardation plate. The retardation plate 1 having a circular shape may be formed. A plate-shaped retardation plate having substantially the same thickness may be provided at another place between the polarizing plate 7B and the transparent glass substrate 8B or between the polarizing plate 7A and the transparent glass substrate 8A.

Example 7 FIG. 9 is a partial cross-sectional view of a liquid crystal display element of Example 7 of the present invention.

In this embodiment, an example of a liquid crystal display device having a color filter will be shown. Reference numeral 17 denotes a color filter, of which R is a red filter, G is a green filter, B is a blue filter, and 18 is a flattening film (or a protective film for the color filter). The color filters 17 are formed in stripes by repeating red, green, and blue at positions corresponding to pixels. The color filter 17 is formed as follows, for example. First, a dyeing base material such as an acrylic resin is formed on the surface of the transparent glass substrate 8B, and the dyeing base material other than the red filter R forming region is removed by a photolithography technique. After that, the dyed substrate is dyed with a red dye and a fixing process is performed to form a red filter R. Next, the green filter G and the blue filter B are sequentially formed by performing the same process. In some cases, instead of dyeing the base material with a dye, a base material to which a pigment of a predetermined color is added may be sequentially formed. The flattening film 18 is formed of a transparent resin material such as acrylic resin or epoxy resin.

In this embodiment, after the transparent electrode 9A was formed on the transparent glass substrate 8A, the striped retardation plate 1 was formed thereon. In the case of a liquid crystal display element having a color filter formed thereon, the film thickness of the color filters R, G, B of the respective colors differ depending on the properties of the dyes and pigments, the order in which they are formed, and the flattening film 18 also formed thereon. Under the influence, as a result, the liquid crystal Δn · d (dR, dG, d
The disturbance of B) occurs. In this embodiment, the film thicknesses of the color filters R, G, B of the respective colors are measured and investigated in advance, and the results show that the stripe shapes are formed corresponding to the nonuniformity of the film thicknesses of the color filters R, G, B of the respective colors. The thickness and / or the birefringence of each stripe of the retardation film 1 are determined and formed.
That is, for example, as shown in FIG. 9, the film thickness of the stripe of the retardation film 1 formed at the position corresponding to the red filter R having a large film thickness is made thin, and the green filter G corresponding to a thin film is formed. The film thickness of the stripe of the retardation film 1 formed at the position is formed thick, and the stripe of the retardation plate 1 corresponding to the blue filter B of the intermediate film thickness is formed to the intermediate film thickness.

In this way, in the present embodiment, the stripe-shaped retardation plate 1 makes it possible to make dR, dG, and dB uniform, and the effect of the retardation plate 1 also performs color compensation. It was possible to improve the display quality.

Method 1 for Forming Striped Phase Difference Plate FIG. 10 is a diagram showing a first method for forming the striped phase difference plate 1 by printing. (A) is a side view showing a printing roller, (b) and (c) are process sectional views.

Reference numeral 19 is a printing plate, and 20 is a printing roller.

By rotating the printing roller 20 on which the printing plate 19 is installed and printing on the substrate 4 using the printing plate 19, first, the striped retardation plate 1a is formed. Next, the printing plate 19 on the printing roller 20 was exchanged, and printing was performed again on the same substrate 4 on which the retardation plate 1a was formed to form a striped retardation plate 1b. When the adhesiveness between the substrate 4 and the organic polymer of the retardation plates 1a and 1b is not good, heat treatment such as raising the temperature of the substrate 4 or adhesion of the surface of the substrate 4 on which the retardation plates 1a and 1b are formed with adhesiveness is beforehand performed. Perform a chemical treatment such as attaching a certain organic substance.

Further, the printing plate 19 was replaced and printing was performed (not shown). By repeating the printing, a plurality of stripe-shaped retardation films 1 having arbitrary thicknesses at arbitrary positions
Can be formed. When a phase difference is provided in the entire liquid crystal display element, the stripe-shaped phase difference plate 1
It is effective to use a plate-shaped retardation plate having substantially the same thickness as the substrate 4 on which is provided. Further, by reprinting another retardation plate having another birefringence on the already formed stripe retardation plate 1 or changing the printing direction,
It is possible to control the value of the phase difference.

Method 2 of Forming Striped Phase Difference Plate FIG. 11A to FIG. 11C are process sectional views showing a second method of forming the stripe phase difference plate 1 by using light irradiation with ultraviolet rays. Is.

Reference numeral 4 is a substrate, 1'is an organic polymer layer, 21 is ultraviolet rays (UV), 22 is a photomask, and 1a is a striped retardation plate.

First, as shown in (a), an organic polymer layer 1'is formed on the substrate 4. Next, as shown in (b), a photomask 21 having a predetermined opening pattern is placed on the substrate 4 on which the organic polymer layer 1'is formed, and ultraviolet rays 21 are irradiated. The molecular structure of the organic polymer layer 1 ′ at the portion irradiated with the ultraviolet ray 21 is destroyed, and the portion has no phase difference. By irradiating the ultraviolet rays 21 in a stripe shape in this way, a stripe-shaped retardation plate (a retardation plate in which a retardation occurs in a stripe shape) 1a could be formed. Further, the stripe-shaped retardation plate 1a can be formed as shown in (c) by repeating exposure and development and etching as in a normal photolithography method.

Method 3 of forming stripe-shaped retardation film 3 There is a mechanical cutting method as another method of forming a stripe-shaped retardation plate other than the printing method of FIG. 10 and the method of irradiating light such as ultraviolet rays of FIG. A conventional retardation film formed into a film by uniaxial stretching or a retardation plate formed by the method of FIGS. 10 and 11 is used to mechanically cut a predetermined portion with a cutter or the like to form a stripe shape. A retardation plate can be formed.

Although the present invention has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. . For example, the present invention is applicable not only to a simple matrix type liquid crystal display device, but also to an active matrix type liquid crystal display device using a thin film transformer or the like as a switching element, thereby achieving high contrast. Also, the twist angle of the liquid crystal is 180
By setting it to be equal to or above, it is possible to provide a liquid crystal display device which is not colored and is driven by a high time division. In addition to the striped retardation plate 1 according to the present invention, a conventional retardation plate 1 is used.
By adding one or more sheets, it is possible to compensate for the phase difference depending on the viewing angle direction, which is effective in improving the viewing angle characteristics. Also,
As the substrate for forming the stripes of the retardation plate 1 according to the present invention, the transparent glass substrates 7A, 7A of the liquid crystal display element 11
B, organic polymer film such as triacetyl cellulose,
Alternatively, a conventional plate-shaped retardation plate having approximately the same thickness can be used. Further, the same effect can be obtained by using a retardation plate having a stripe-shaped retardation as shown in FIG. 11B, for example. When the striped retardation plate 1 is formed on the transparent glass substrates 7A and 7B of the liquid crystal display element 11, a protective film such as an acrylic resin or an epoxy resin should be formed to prevent ions from flowing out. Is desirable.

[0065]

As described above, according to the present invention,
Low power consumption because auxiliary light sources such as backlight are not required,
In addition, it is possible to realize a multicolor display without a color filter and to realize a bright display liquid crystal display device. In addition, display unevenness due to non-uniformity of the thickness of the transparent electrode, the color filter, or the black matrix can be compensated, and the display quality can be improved.

[Brief description of drawings]

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

FIG. 2 is a diagram illustrating a display principle of the liquid crystal display element shown in FIG.

FIG. 3 is a cross-sectional view of another embodiment of the retardation plate according to the present invention.

FIG. 4 is a partial cross-sectional view of a liquid crystal display element of Example 3 of the present invention.

5 is a diagram showing a spectral reflectance in a bright state in the liquid crystal display element of Example 3. FIG.

FIG. 6 is a diagram showing a relationship between effective voltage and reflectance of the liquid crystal display element of Example 4.

FIG. 7 is a partial cross-sectional view of a liquid crystal display element of Example 5 of the present invention.

FIG. 8 is a partial cross-sectional view of a liquid crystal display element of Example 6 of the present invention.

FIG. 9 is a partial cross-sectional view of a liquid crystal display element of Example 7 of the present invention.

10A to 10C are diagrams showing a method of forming a striped retardation plate by printing.

11A to 11C are process cross-sectional views showing a method of forming the stripe-shaped retardation film 1 by using light irradiation with ultraviolet rays.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Stripe retarder, 2 ... Adhesive material layer, 3 ... Insulating film, 4 ... Substrate, 5 ... Flattening film, 6 ... Light absorption sheet, 7 ...
Polarizing plates, 8A, 8B ... Transparent glass substrate, 9A, 9B ... Striped transparent electrodes, 10A, 10B ... Alignment film, 11
... Liquid crystal layer, 12 ... Liquid crystal display element, 13 ... Power supply, 14 ... Red spectral reflectance, 15 ... Green spectral reflectance, 16 ... Blue spectral reflectance, 17 ... Color filter, 18 ... Flattening film, 19
... printing plate, 20 ... printing roller, 21 ... ultraviolet light, 22 ... photomask, R ... red filter, G ... green filter, B
... blue filter.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tatsuhisa Fujii 3300 Hayano, Mobara, Chiba Prefecture Electronic Device Division, Hitachi, Ltd. (72) Tomohide Ohira 3300 Hayano, Mobara, Chiba Hitachi Device Corporation (72) Inventor Tatsunori Fumikura 3681 Hayano, Mobara-shi, Chiba Hitachi Device Engineering Co., Ltd.

Claims (19)

[Claims] 1. Two transparent insulating substrates are stacked with a predetermined gap so that the surfaces on which the transparent electrodes and the alignment film are provided face each other, and are provided in a frame shape around the edge between the two substrates. A liquid crystal display element formed by bonding the two substrates with a sealing material and sealing a liquid crystal twisted in the thickness direction between the two substrates inside the sealing material; 1. A polarizing plate provided outside the first substrate, a light absorbing member provided outside the other second substrate, and a striped retardation plate provided on at least one of the two substrates. A liquid crystal display device characterized by being formed. 2. Two transparent insulating substrates are stacked with a predetermined gap so that the surfaces on which the transparent electrodes and the alignment film are provided face each other, and are provided in a frame shape around the edge between the two substrates. A liquid crystal display element formed by bonding the two substrates with a sealing material and sealing a liquid crystal twisted in the thickness direction between the two substrates inside the sealing material, and a polarization device provided outside the both substrates. A liquid crystal display device comprising a plate, wherein the liquid crystal display device comprises a striped retardation plate provided on at least one of the both substrates. 3. Two transparent insulating substrates are stacked with a predetermined gap therebetween so that the surfaces provided with the transparent electrodes and the alignment film face each other, and are provided in a frame shape around the edge between the two substrates. A liquid crystal display device comprising a liquid crystal display element formed by bonding the both substrates with a sealing material and sealing a liquid crystal twisted in a thickness direction between the two substrates inside the sealing material. A liquid crystal display device comprising a retardation film patterned corresponding to at least one of a transparent electrode, a color filter and a black matrix on at least one side. 4. The liquid crystal display device according to claim 1, wherein the retardation plate is composed of a plurality of stripes different in at least one of thickness and birefringence. 5. The liquid crystal display device according to claim 1, wherein the stripe is made of an organic polymer twisted in a thickness direction. 6. The liquid crystal display device according to claim 1, wherein the striped retardation plate is a retardation plate having a striped phase difference. 7. The liquid crystal display device according to claim 1, wherein the refractive index of the liquid crystal in the parallel direction is approximately 1.5 to 1.6. 8. The liquid crystal display device according to claim 1, wherein the twist angle of the retardation plate is approximately 180 ° or more. 9. The refractive index of the retardation plate in the vertical direction is approximately 1.6 to 2.1.
2. The liquid crystal display device according to 2 or 3. 10. The striped phase difference plate has a thickness of approximately 200 nm or more.
Or the liquid crystal display device according to item 3. 11. The liquid crystal display device according to claim 1, wherein the twist angle of the liquid crystal is approximately 180 ° or more. 12. The liquid crystal display device according to claim 1, wherein the stripes of the retardation film are formed on a surface of a substrate different from the transparent insulating substrate. 13. The retardation plate according to claim 12, wherein the substrate is an organic polymer film and is a plate-shaped retardation plate having substantially the same thickness. 14. The transparent electrode of each of the substrates has a plurality of stripes extending in directions perpendicular to each other when viewed from a direction perpendicular to the surfaces of the substrates. 2. The liquid crystal display device according to 2 or 3. 15. The liquid crystal display device according to claim 1, wherein each stripe of the retardation film is formed along at least one of a transparent electrode, a color filter and a black matrix. . 16. At least one of the thickness and the birefringence of each stripe of the retardation plate has a transparent electrode, a color filter,
The control is performed according to at least one of the thicknesses of the black matrix.
The described liquid crystal display device. 17. The thickness of the stripe of the retardation plate,
A reflection spectrum of bright display is set to a predetermined plurality of colors by at least one of the birefringences, and one set is repeatedly formed with a predetermined number of the stripes to enable color display. Item 4. A liquid crystal display device according to item 1, 2 or 3. 18. The liquid crystal display according to claim 1, 2 or 3, wherein at least one plate-shaped retardation plate having substantially the same thickness is provided between the polarizing plate and the substrate. apparatus. 19. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is of an active matrix type.
The described liquid crystal display device.