JPH0553126A - Liquid crystal display element - Google Patents

Abstract

PURPOSE:To avert the deterioration in local characteristics by the damage of oriented films and the generation of vortexes at the time of infecting a liquid crystal as well to eliminate a contraction and destruction of the cellgap of the liquid crystal injection aperture part. CONSTITUTION:The entire width on one side of a sealing material 7 is opened to form a liquid crystal injection aperture 71. Dummy sealing materials 91, 91' forming many apertures over the entire width on the opened one side are provided. Then, the inflow speed of the liquid crystal at the time of injection decreases and the damaging of the oriented films is averted. The generation of the vortexes of the liquid crystal near the injection aperture 71 is averted and amoeba phenomena and partial degradation in characteristics are prevented from arising. Further, the installation of the many dummy seals is possible without increasing the inflow speed of the liquid crystal. The generation of the vortexes is averted by forming the dummy seals to the shape to allow the gentle flow of the liquid crystal.

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,
In particular, the present invention relates to a liquid crystal display element having a large display area and eliminating the occurrence of characteristic unevenness of a liquid crystal layer.

[0002]

2. Description of the Related Art A liquid crystal display device is basically based on a structure in which two substrates each having an electrode formed thereon are opposed to each other and liquid crystal is sealed between the two substrates. FIG. 5 is a developed perspective view showing a structure of a main part of a conventional liquid crystal display element, and shows a so-called STN liquid crystal display element as an example.

In the figure, 1 is an upper substrate, 2 is a lower substrate,
3 is an upper electrode formed on the upper substrate, 4 is a lower electrode formed on the lower substrate, 5 is an upper alignment film formed on the upper electrode, 6 is a lower alignment film formed on the lower electrode, 7 is a sealing material, 70 Is a liquid crystal injection opening, and 8 is a liquid crystal layer. After the liquid crystal is injected, the liquid crystal injection opening 70 is sealed with another sealing member (not shown) so that the injected liquid crystal does not leak outside.

The upper and lower substrates 1 and 2 are composed of a transparent member such as a glass plate, on which the upper electrode 3 and the lower electrode 4 which are drive electrodes are formed by a patterning technique such as photolithography, and the electrodes are formed on each electrode. An upper alignment film 5 and a lower alignment film 6 each made of a plastic thin film such as polyimide are deposited. The upper alignment film 5 and the lower alignment film 6 have their optical axes aligned in a predetermined one direction intersecting with each other by a rubbing treatment to give a twist angle to the injected liquid crystal molecules.

The liquid crystal display device having such a structure is laminated on the upper substrate 1 and the lower substrate 2, and at least one layer of retardation film made of a plastic film such as polycarbonate and a pair of polarizing plates are installed. To form a liquid crystal display panel (for example, Japanese Patent Laid-Open No. 2-259621). FIG. 6 is a plan view of a main part for explaining the structure of the liquid crystal injection opening portion of the sealing material in FIG. 5, and the liquid crystal injection opening portion 70 is provided centrally on one side center portion of the substantially rectangular sealing material 7. Then, the liquid crystal is injected through this opening.

The injection opening 70 is provided with a dummy seal 90 for preventing the upper and lower substrates from being bent or crushed in the opening.

[0007]

In the above-mentioned structure, when manufacturing a large-screen liquid crystal display element, the injected liquid crystal is concentrated from the liquid crystal storage source (not shown) into the injection opening 70 as shown by the arrow A. Then, it flows into the display area defined by the sealing material 7 through the narrow gap of the injection opening 70.

Therefore, the liquid crystal flowing into the display area is
It moves rapidly as shown by arrow B, or swirls to the side of the injection opening 70 as shown by arrow C.
Such a phenomenon becomes more remarkable as the display area becomes larger, that is, as the amount of injected liquid crystal increases, and in particular, the upper and lower alignment films 5 and 6 near the injection opening are rubbed and scratched, or scraped from the sealant or the alignment film. The fine particles are mixed as ionic impurities into the liquid crystal layer, or these impurities are concentrated in unspecified areas, causing a so-called amoeba phenomenon that causes a different brightness area on the display, or partially There was a problem of causing characteristic deterioration.

Further, if the number of dummy seals 90 is reduced and the opening area is widened in order to reduce the inflow speed of the liquid crystal, the interval (cell gap) between the upper and lower substrates may be narrowed or the opening itself may be crushed. There was a problem. An object of the present invention is to solve the above-mentioned problems of the prior art, to prevent the increase in the injection speed of the liquid crystal even when injecting a large amount of liquid crystal, and to eliminate the constriction or collapse of the cell gap of the liquid crystal injection opening. Another object of the present invention is to provide a liquid crystal display device.

[0010]

In order to achieve the above object, the present invention provides two rectangular electrode plates (1,
2), and a sealing material (7) which is interposed in the peripheral portion between the two rectangular electrode plates to fix the two rectangular electrode plates to define a display area, and the sealing material. In a liquid crystal display element having a liquid crystal layer (8) sealed in a display area,
The sealing material (7) has a substantially rectangular shape with an injection portion (71) whose one side of the display area is open, and
It is characterized in that it comprises dummy seals (91, 91 ') forming a large number of openings over the entire width of the opened one side.

The dummy seal material has a cross section in which a plurality of "(" shapes and ")" shapes are alternately arranged in a staggered manner (FIG. 2), and a plurality of "<" shapes and a ">" shape are alternately staggered. An array (FIG. 3), a plurality of “−”-shaped arrays arranged in a staggered manner (FIG. 4), or another shape for smoothing the flow of liquid crystal can be adopted.

[0012]

[Function] Since the liquid crystal injection opening has the entire width of one side of the seal material (7), the liquid crystal inflow speed becomes low at the time of injection, and the seal material in the opening is scraped off. The alignment film in the display area is not scratched. Further, since the vortex of the liquid crystal is not generated in the vicinity of the injection opening, and even if impurities are mixed in, it is not concentrated on a specific portion, the occurrence of the above-mentioned amoeba phenomenon and the partial deterioration of the characteristics do not occur.

Further, since the injection opening has the entire width of one side of the sealing material, a large number of dummy seals can be installed without increasing the liquid crystal inflow speed, and the dummy seals have a shape in which the liquid crystal gently flows. As a result, it is possible to avoid the generation of the vortex flow described above.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a developed perspective view for explaining a first embodiment of a liquid crystal display device according to the present invention. As in the conventional example, 1 is an upper substrate made of a glass substrate, 2 is a lower substrate, and 3 is an upper substrate. The upper electrode 4 formed on the lower substrate, 4 the lower electrode formed on the lower substrate, 5 the upper alignment film formed on the upper electrode, 6 the lower alignment film formed on the lower electrode, and 7 the sealing material. Further, 71 is a liquid crystal injection opening, 8 is a liquid crystal layer, and 91, 9
Reference numeral 1'denotes a dummy seal made of the same material as the seal material 7.

The liquid crystal injection opening 71 is sealed with another sealing material (not shown) after the injection of the liquid crystal so that the injected liquid crystal does not leak to the outside, as in the conventional case.
On the surfaces of the upper substrate 1 and the lower substrate 2 facing each other, an upper electrode 3 and a lower electrode 4 which are drive electrodes are formed by a patterning technique such as photolithography, and a plastic thin film such as polyimide is formed on each electrode. The upper alignment film 5 and the lower alignment film 6 are deposited.

The upper and lower alignment films 5 and 6 have their optical axes aligned in a predetermined direction intersecting with each other by a rubbing process to give a twist angle to the injected liquid crystal molecules. Then, the liquid crystal display panel is constructed by laminating the liquid crystal display device on the upper substrate 1 and the lower substrate 2 and installing at least one layer of retardation film obtained by uniaxially stretching a plastic film such as polycarbonate and a pair of polarizing plates. To do.

The liquid crystal injection opening 71 is opened over the entire width of one side of the rectangular sealing material 7, and the liquid crystal is injected through the liquid crystal injection opening 71. Therefore, in the case of a large-screen liquid crystal display element having a large display area constituted by the liquid crystal layer 8 defined by the sealing material 7, the amount of injected liquid crystal is large, but the liquid crystal injection opening 71 has a large area. In addition, the speed of the liquid crystal passing through is moderate.

Dummy seals 91, 91 'for maintaining a predetermined cell gap between the upper substrate 1 and the lower substrate 2 in the liquid crystal injection opening 71 and for avoiding bending or collapsing between the substrates.
Is installed. FIG. 2 is an enlarged partial plan view showing the liquid crystal injection opening portion of the first embodiment, in which dummy seals 91, 91 'have a plurality of "(" and ")" cross sections alternately. As shown by arrow D, the injected liquid crystal smoothly flows through the arrangement gap between the dummy seals 91 and 91 ′ and uniformly flows into the display area as shown by arrow E.

Therefore, according to this embodiment, the alignment film and the sealing material (or the dummy seal) are damaged due to the high speed liquid crystal flow as in the prior art, and the impurities are concentrated due to the vortex generation of the liquid crystal. Thus, it is possible to display an image with uniform characteristics over the entire display area. FIG. 3 is an enlarged partial plan view showing a liquid crystal injection opening portion for explaining a second embodiment of the liquid crystal display device according to the present invention, in which the dummy seals 92 and 92 'are
A plurality of "<" and ">)" cross sections are alternately arranged in a staggered manner, and as shown by arrow F, the injected liquid crystal smoothly flows through the arrangement gap of the dummy seals 92, 92 '. Then, as shown by the arrow G, it uniformly flows into the display area.

Therefore, also in this embodiment, the alignment film and the sealing material (or the dummy seal) may be damaged due to the high speed liquid crystal flow as in the prior art, and the impurities may be concentrated due to the vortex generation of the liquid crystal. Instead, it is possible to display an image with uniform characteristics over the entire display area. FIG. 4 is a partial plan view showing, in an enlarged manner, a liquid crystal injection opening portion for explaining a third embodiment of the liquid crystal display device according to the present invention.
Has a plurality of "-"-shaped cross sections alternately arranged in a staggered manner, and as shown by an arrow H, the injected liquid crystal smoothly flows through the arrangement gap of the dummy seals 93, 93 '. As indicated by I, it uniformly flows into the display area.

Therefore, according to the present embodiment as well, damage to the alignment film and the sealing material (or the dummy seal) due to the high speed flow of the liquid crystal as in the prior art,
There is no concentration of impurities due to the generation of liquid crystal vortices,
The image can be displayed with uniform characteristics over the entire display area.

[0022]

As described above, according to the present invention,
Since the liquid crystal injection opening has the entire width of one side of the sealing material, the inflow speed of the liquid crystal at the time of injection is reduced, and the sealing material in the injection opening is scraped off. The alignment film in the display area is not scratched. In addition, a vortex of liquid crystal does not occur near the liquid crystal injection opening, and even if impurities are mixed in, it does not concentrate on an unspecified portion, so that irregular brightness differences and shadows occur locally on the display surface. The occurrence of amoeba phenomenon and partial deterioration of characteristics do not occur.

Further, since the liquid crystal injection opening has the entire width of one side of the sealing material, a large number of dummy seals can be installed without increasing the liquid crystal inflow speed, and the dummy seals have a shape in which the liquid crystal gently flows. By doing so, it is possible to avoid the generation of the above-mentioned eddy current, and to provide a high-performance liquid crystal display device that solves the problems of the above-mentioned conventional techniques.

[Brief description of drawings]

FIG. 1 is a developed perspective view illustrating a first embodiment of a liquid crystal display device according to the present invention.

FIG. 2 is a partial plan view showing an enlarged liquid crystal injection opening portion of the first embodiment of the present invention.

FIG. 3 is a partial plan view showing an enlarged liquid crystal injection opening portion for explaining a second embodiment of the liquid crystal display element according to the present invention.

FIG. 4 is a partial plan view showing an enlarged liquid crystal injection opening portion for explaining a third embodiment of the liquid crystal display element according to the present invention.

FIG. 5 is a developed perspective view showing a structure of a main part of a conventional liquid crystal display element.

FIG. 6 is a plan view of relevant parts for explaining a structure of a liquid crystal injection opening portion of a sealing material in a conventional liquid crystal display element.

[Explanation of symbols]

1 ... upper substrate, 2 ... lower substrate, 3 ... upper electrode, 4 ... lower electrode, 5 ... upper alignment film, 6 ...
-Lower alignment film, 7 ... Sealing material, 71 ... Liquid crystal injection opening, 8 ... Liquid crystal layer, 91, 91 '... Dummy seal.

Claims (1)

[Claims] 1. A display area is defined by two rectangular electrode plates that are arranged opposite to each other and the two rectangular electrode plates that are inserted in the peripheral portion between the two rectangular electrode plates and are fixed to each other. Sealing material,
In a liquid crystal display element in which a liquid crystal layer is sealed in a display area defined by the sealing material, the sealing material has a substantially rectangular shape with an injection opening whose one side of the display area is open. A liquid crystal display device comprising a dummy seal material forming a large number of openings over the entire width of the released one side.