JP2005049561A - Liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display element whose disruptive strength is increased as a small-sized liquid crystal display element. <P>SOLUTION: A couple of rectangular substrates 2 and 2 are stuck together with a sealing material 3 and liquid crystal is charged between the couple of substrates, and an injection hole 4 formed to inject the liquid crystal between the couple of substrates is arranged on long sides of the substrates 2 and 2 between ends and 1/3 positions when the overall length of the long sides is represented as 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００３１】
表１において、単位のＮはニュートンを意味し、許容荷重は、平均値−３×標準偏差で求めている。表１から、注入口を長辺の中央に配置した比較例に対して、注入口を長辺の端から約１／３の位置に配置した実施例では、液晶表示素子の破壊時荷重の平均値が約１０％増加し、許容荷重においては約２０％増加しており、液晶表示素子の破壊強度が高まっていることが判る。
【００３２】
なお、図示していないが、２枚の基板２Ａ，２Ｂの間には、スペーサが散布されており、基板２Ａ，２Ｂの間隔（セルギャップ）を調整している。また、基板２Ａ，２Ｂの外側表面には、位相差板、偏光板等の光学フィルムが貼付されていてもよい。
【００３３】
本発明は前述した実施の形態に限定されるものではなく、必要に応じて種々の変更が可能である。
【００３４】
例えば、注入口は一個に限らず、一つの長辺に複数個形成することができる。複数形成する場合、一方の端側の１／３までの間にのみ形成してもよいが、液晶の注入時間の短縮、液晶の這い上がり跡等の配向不良の発生し難さの面から、なるべく離間するように、両端の１／３までの間に分散して配設した方がよい。さらに、複数個の注入口を両端の１／３までの間に分散して配設する場合は、長辺の中央に対して左右対称となるように配置すると液晶の配向不良に対して有効である。
【００３５】
【発明の効果】
以上のとおり、本発明の液晶表示素子は、一対の基板の間に液晶を注入するために設けられた注入口が基板の長辺の全長を１とした時に、端から１／３までの間の長辺に配置することにより、小型の液晶表示素子において、中央付近に注入口を設けた場合に比べて、外部からの圧力に対する耐圧性を高めることができる。
【００３６】
更に、厚さが０．５ｍｍ以下の基板を使用すると、耐圧性が低下するので、本発明を採用することが好適である。
【００３７】
更に、表示部の対角が２．２インチ以下の小型の液晶表示素子は、特に、周辺部におけ注入口の割合が大きく、表示部の中央付近から注入口までの距離も短いので、注入口に応力が集中しやすく、それによる耐圧性の低下が無視できないものであったため、本発明を採用することが好適である。
【図面の簡単な説明】
【図１】本発明の液晶表示素子の概略平面図
【図２】（Ａ）および（Ｂ）は、それぞれ従来の液晶表示素子の概略断面図および概略平面図
【符号の説明】
２ 基板
３ シール材
４ 注入口
５ 封止材
６ 表示部
７ 液晶表示素子[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid crystal display element having a structure in which liquid crystal is sealed between two substrates, and more particularly to a small and thin liquid crystal display element.
[0002]
[Prior art]
Conventionally, liquid crystal display elements have been used in various applications, but in recent years, they have been widely used as display devices for portable devices such as mobile phones, portable information terminals, digital cameras, and digital video cameras. Liquid crystal display elements for portable devices are required to be smaller, thinner and lighter in order to improve portability.
[0003]
2A and 2B are a schematic cross-sectional view and a schematic plan view, respectively, of a conventional liquid crystal display element. In the conventional liquid crystal display element 10, a pair of substrates 11A and 11B are arranged so as to face each other, and electrodes 12 for applying a voltage for driving liquid crystal are applied to the mutually facing surfaces of these substrates 11A and 11B, and An alignment film (not shown) whose surface is rubbed to align liquid crystal molecules in a certain form is laminated. One substrate 11A of the pair of substrates is provided with a projecting portion 19 formed to be larger than the other substrate 111B in a planar shape, and this projecting portion 19 is provided with a terminal for connecting the electrode 12 to an external circuit. It has been.
[0004]
Then, the sealing material 13 is applied to the peripheral portion of one of the two substrates 11A and 11B subjected to such an orientation treatment, and the distance between the two substrates is within the surface surrounded by the sealing material 13. In a state where the spacers 14 for adjusting the (cell gap) are uniformly dispersed, both the substrates 11A and 11B are bonded together and formed integrally. The sealing material 13 does not completely surround the peripheral portion of one substrate 11A, but is provided with an injection port 15 for injecting liquid crystal between the substrates 11A and 11B.
[0005]
After the region surrounded by both the substrates 11A and 11B and the sealing material 13 is in a vacuum state, liquid crystal is injected from the injection port 15 into the region between the substrates 11A and 11B by immersing the injection port 15 in the liquid crystal material. Then, the liquid crystal 17 is sealed between the two substrates 11A and 11B by sealing the injection port 15 with the sealing material 16.
[0006]
Then, information is displayed by changing the orientation of the liquid crystal 17 by changing the voltage of the electrode 12 constituting the pixel in the display unit 18 (indicated by a dotted line in FIG. 2).
[0007]
In such a conventional liquid crystal display element 10, the injection port 15 is disposed near the center of the short side or the long side of the liquid crystal display element 10 so that the liquid crystal can be injected symmetrically.
[0008]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-357840
[Problems to be solved by the invention]
When the liquid crystal display element 10 is incorporated in a portable device or the like, the liquid crystal display element 10 is accommodated in the casing of the portable device body, but the display unit 18 is exposed so that it can be observed from the outside or covered with a transparent resin cover. It was just being broken.
[0010]
For this reason, the peripheral part of the liquid crystal display element 10 is protected by the housing of the apparatus main body, but since the pressure is directly applied to the display part 18 from the outside, it is necessary to increase the pressure resistance, that is, the breaking strength. In particular, in a liquid crystal display element for portable devices, the thickness of the substrates 11A and 11B is reduced in order to reduce the thickness and weight, so that the strength of the substrates 11A and 11B is low, so that the breaking strength is increased. Was important.
[0011]
The present inventor has found that the injection port 15 affects the breaking strength in a small liquid crystal display element. The reason is guessed as follows. The peripheral portion other than the injection port 15 is bonded with a sealing material, and the gap and the adhesive force are uniform. On the other hand, the injection port 15 is sealed with the sealing material 16 instead of the sealing material 13, so that This is because there is a possibility that stress is concentrated on the injection port 15 when pressure is applied to the display unit 18.
[0012]
In the case of a large-sized liquid crystal display element, the ratio of the injection port 15 in the peripheral portion is small, and the distance from the display portion 18, particularly the center where pressure is easily applied, to the injection port 15 is separated. Concentration of the liquid crystal is difficult to occur, and even when stress concentrates on the injection port 15, the influence on the breaking strength of the liquid crystal display element is small. However, in a small liquid crystal display element, the ratio of the injection port 15 in the peripheral portion is large, and since the distance from the vicinity of the center of the display unit 18 to the injection port 15 is short, stress tends to concentrate on the injection port 15. The decrease in fracture strength due to was not negligible.
[0013]
An object of the present invention is to provide a liquid crystal display element having a high breaking strength in a small liquid crystal display element for portable devices.
[0014]
[Means for Solving the Problems]
In order to achieve the above-described object, a liquid crystal display element of the present invention is a liquid crystal display element in which a pair of rectangular substrates are bonded together with a sealing material, and liquid crystal is sealed between the pair of substrates. The injection port provided for injecting the liquid crystal in between is arranged on the long side from the end to 1/3 when the total length of the long side of the substrate is 1.
[0015]
By adopting such a configuration, in a small-sized liquid crystal display element, the pressure resistance against external pressure can be improved as compared with the case where an injection port is provided near the center. In the present specification, the position of the inlet is based on the center of the width of the inlet.
[0016]
Furthermore, the liquid crystal display element of the present invention is characterized in that the substrate has a thickness of 0.5 mm or less.
[0017]
When a substrate having a thickness of 0.5 mm or less is used, the pressure resistance is lowered, so that it is preferable to employ the present invention.
[0018]
Furthermore, the liquid crystal display element of the present invention is characterized in that the diagonal of the display portion of the liquid crystal display element is 2.2 inches or less.
[0019]
A small liquid crystal display element with a diagonal of 2.2 inches or less in the display portion has a particularly large ratio of the injection port in the peripheral portion and the distance from the center of the display portion to the injection port is short. It is preferable to employ the present invention because the stress tends to concentrate and the resulting decrease in pressure resistance cannot be ignored.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0021]
FIG. 1 is a schematic plan view of a liquid crystal display element of the present invention. The liquid crystal display element 7 in the present invention is a device in which the arrangement of the injection port 4 is devised, and its laminated structure is the same as that of a conventional liquid crystal display element.
[0022]
The liquid crystal display element 7 is small as used in a portable device, and in particular, the diagonal length (L in FIG. 1) of the display unit 6 (indicated by a dotted line in FIG. 1) is 2.2 inches ( About 56 mm or less is preferable. The liquid crystal display element 7 includes a pair of rectangular substrates 2A and 2B, the peripheral portions of which are bonded together with a sealing material 3 except for the injection port 4, and the injection port 4 is sealed with a sealing material 5 so that the pair of substrates 2A and 2B The liquid crystal is sealed between 2B.
[0023]
The pair of substrates 2A and 2B are formed by laminating an electrode for applying a voltage for driving a liquid crystal on opposite surfaces and an alignment film having a rubbing process on the surface for arranging liquid crystal molecules in a certain form. ing. One substrate 2A of the pair of substrates is provided with a protruding portion 8 formed in a planar shape larger than the other substrate 2B, and the protruding portion 8 is provided with a terminal for connecting an electrode to an external circuit. Yes. When an active matrix type liquid crystal display element is used as the liquid crystal display element 7, a switching element for driving each pixel, for example, a TFT (Thin Film Transistor) is formed on the surface of one substrate 2A. Has been.
[0024]
As the substrates 2A and 2B, a glass substrate, a synthetic resin substrate, a semiconductor substrate, or the like can be used, and a transparent substrate is used as a display-side substrate on which an image is displayed. The substrates 2A and 2B preferably have a thickness of 0.5 mm or less in order to reduce the thickness and weight.
[0025]
The sealing material 3 is applied so as to surround the peripheral portions of the substrates 2A and 2B, and bonds the substrates 2A and 2B. The sealing material 3 does not completely surround the peripheral portions of the substrates 2A and 2B, but has an opening 4 for injecting liquid crystal after bonding the substrates 2A and 2B by providing a cut in one place. Can be formed. Therefore, the arrangement of the injection ports 4 can be determined by the application pattern of the sealing material 3. The injection port 4 is sealed with a sealing material 5 made of an ultraviolet curable resin after injecting liquid crystal between both substrates 2A and 2B, and liquid crystal is sealed between the pair of substrates 2A and 2B. .
[0026]
In the small-sized liquid crystal display element 7, the width of the injection port 4 is several mm. In the liquid crystal display element 7 of the present invention, when the total length of the long sides of the substrates 2A and 2B is 1, the length is 1/3 from the end. It arrange | positions so that the center of the injection port 4 may be located in the long side between. In addition, a protrusion is provided on the long side of one of the substrates, and when the lengths of the long sides of the two substrates 2A and 2B are different, the long side of the portion where the two substrates 2A and 2B overlap is used. The length (that is, the region excluding the protruding portion) is set to 1 as a reference. In FIG. 1, the injection port 4 is arranged at a position 1/3 from the upper end of the long side, but it may be from the lower end.
[0027]
Further, the position of the injection port 4 is preferably close to the end, and is preferably arranged at a position from the end to 1/4, and more preferably at a position from the end to 1/5. Further, the width of the inlet 4 should be small, and preferably the width of the inlet 4 is 5 mm or less.
[0028]
Using a pair of substrates 2A and 2B that overlap in a rectangular region having a long side of 28.7 mm and a short side of 10.6 mm, the diagonal length (L in FIG. 1) of the display unit 6 is 1. In the 15-inch (about 29 mm) liquid crystal display element 7, a liquid crystal display element 7 arranged so that the center of the inlet 4 having a width of 2 mm is 9.4 mm from the ends of the long sides of the substrates 2A and 2B is prepared as an example. did. Further, as a comparative example, a liquid crystal display element in which an injection port is arranged at the center of the long side of the substrate was prepared.
[0029]
In order to measure the breaking strength of these liquid crystal display elements, pressure was applied to the center while supporting both ends of the long side, and the load when the liquid crystal display element was broken was measured. Table 1 shows the results.
[0030]
[Table 1]

[0031]
In Table 1, the unit N means Newton, and the allowable load is obtained as an average value −3 × standard deviation. From Table 1, compared with the comparative example in which the injection port is arranged at the center of the long side, in the example in which the injection port is arranged at a position about 1/3 from the end of the long side, the average load at break of the liquid crystal display element The value is increased by about 10%, and the allowable load is increased by about 20%, indicating that the breaking strength of the liquid crystal display element is increased.
[0032]
Although not shown, spacers are scattered between the two substrates 2A and 2B to adjust the distance (cell gap) between the substrates 2A and 2B. Moreover, optical films, such as a phase difference plate and a polarizing plate, may be stuck on the outer surfaces of the substrates 2A and 2B.
[0033]
The present invention is not limited to the embodiments described above, and various modifications can be made as necessary.
[0034]
For example, the number of injection ports is not limited to one, and a plurality of injection ports can be formed on one long side. In the case of forming a plurality, it may be formed only up to 1/3 of one end side, but from the aspect of shortening the injection time of the liquid crystal, the difficulty of occurrence of alignment defects such as the scooping up of the liquid crystal, It is better to disperse and arrange between 1/3 of both ends so as to be separated as much as possible. Furthermore, in the case where a plurality of injection ports are distributed between 1/3 of both ends, it is effective for liquid crystal alignment failure if they are arranged symmetrically with respect to the center of the long side. is there.
[0035]
【The invention's effect】
As described above, in the liquid crystal display element of the present invention, when the injection port provided for injecting the liquid crystal between the pair of substrates assumes the total length of the long side of the substrate to be 1/3 from the end. By arranging them on the long side, the pressure resistance against pressure from the outside can be enhanced in a small liquid crystal display element as compared with the case where an injection port is provided near the center.
[0036]
Furthermore, when a substrate having a thickness of 0.5 mm or less is used, the pressure resistance is lowered, so that the present invention is preferably employed.
[0037]
In addition, a small liquid crystal display element with a diagonal of 2.2 inches or less in the display portion has a particularly large ratio of the injection port in the peripheral portion, and the distance from the vicinity of the center of the display portion to the injection port is short. It is preferable to employ the present invention because stress tends to concentrate at the inlet, and the resulting decrease in pressure resistance cannot be ignored.
[Brief description of the drawings]
FIG. 1 is a schematic plan view of a liquid crystal display element of the present invention. FIGS. 2A and 2B are a schematic cross-sectional view and a schematic plan view of a conventional liquid crystal display element, respectively.
2 Substrate 3 Sealing material 4 Inlet 5 Sealing material 6 Display unit 7 Liquid crystal display element

Claims (3)

In a liquid crystal display element in which a pair of rectangular substrates are bonded together with a sealing material and liquid crystal is sealed between the pair of substrates, an injection port provided for injecting liquid crystal between the pair of substrates is the substrate The liquid crystal display element is characterized by being arranged on the long side from the end to 1/3 when the total length of the long side is 1. The liquid crystal display element according to claim 1, wherein the thickness of the substrate is 0.5 mm or less. The liquid crystal display element according to claim 1, wherein a diagonal of a display portion of the liquid crystal display element is 2.2 inches or less.

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