JPS61258224A - Liquid crystal element - Google Patents

Abstract

PURPOSE:To improve contrast characteristics and the reliability of the titled element by giving a uniaxial horizontal orientation processing on a surface contacting with a liquid crystal lying on one of the surfaces of a substrate, and also by giving a nonaxial horizontal orientation processing on the surface of an another substrate. CONSTITUTION:Transparent electrodes 3, 4 composed of a nesa film are provided on the one side of both substrates 1, 2 respectively, and then, are coated with a polyimide resin on the each surfaces thereof. The obtd. surface of the substrate 1 is carried out a rubbing treatment in a uniaxial direction 7, and then, is sticked to the another substrate 2 which is not performed the rubbing treatment with a prescribed gap. The DOBAMBC type mixed composition of the ferrodielectric liquid crystal is sealed between the gap. The titled element is prepared by substituting the rubbing treated substrate 1 with the substrate treated with SiO by a slant vapor-deposition at the vapor-deposition angle of 10 deg. to form the liquid crystal element. And, the rubbing treated substrate 1 is substituted with the substrate treated by the SiO slant vapor-deposition at the vapor-deposition angle of 40 deg., thereby obtaining the titled element having the excellent contrast and responsibility.

Description

【発明の詳細な説明】 （発明の技術分野） 本発明は強誘電性液晶を用いた液晶表示装置において特
に液晶の配向に関するものである。DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention particularly relates to alignment of liquid crystal in a liquid crystal display device using ferroelectric liquid crystal.

（発明の技術的背景およびその問題点〕液晶素子は、腕
時計、電卓をはじめとしてパーンナルコンピュータ用デ
ィスプレイ、ポケットカラーテレビなど幅広く電気光学
装置に利用されている。しかし現在使用されているネマ
チック液晶は電気光学応答時間が約５０ｍ秒と遅いため
、高速応答が要求される分野での利用には制限がおる。(Technical background of the invention and its problems) Liquid crystal elements are widely used in electro-optical devices such as wristwatches, calculators, personal computer displays, and pocket color televisions.However, the nematic liquid crystal currently used Since the electro-optical response time is slow at about 50 msec, its use in fields where high-speed response is required is limited.

また表示合口の点でも限界に達しつつある。We are also reaching the limit in terms of display apertures.

一方、強誘電性液晶はμ秒単位の高速応答性を示すため
、その実用化により液晶素子の用途の飛躍的拡大をもた
らすことが期待されている。On the other hand, since ferroelectric liquid crystals exhibit high-speed response on the microsecond scale, their practical use is expected to dramatically expand the applications of liquid crystal elements.

強誘電性液晶を用いる場合の技術的問題点は配向の困難
性である。強誘電性液晶の電気光学特性の出現には液晶
分子が基板に平行に揃った、いわゆるホモジニアス配向
が必要である。しかし、従来のネマチック液晶のホモジ
ニアス配向に用いられる布で基板をこするラビング方法
では十分良好な配向を得ることができない。そこで従来
とは異なる配向方法が幾つか提案されてきた。例えば磁
場印加法、電場印加法、シェアリング法、スペーサエッ
ヂ法があげられる。しかし各方法とも以下に述べる欠点
を有している。磁場印加法では数に〜十数にガウスの磁
場を必要とするため大型の磁場発生装置が不可欠となり
実用性に乏しい。電場印加法は液晶分子中を電流が流れ
ることにより液晶分子の劣化を招く。シェアリング法は
大きな面積で均一な配向を得ることができない。スペー
サ−エッチ法は大型パネルの作成がこんな困難である。A technical problem when using ferroelectric liquid crystals is the difficulty of alignment. For the electro-optical properties of ferroelectric liquid crystals to appear, so-called homogeneous alignment, in which liquid crystal molecules are aligned parallel to the substrate, is required. However, the conventional rubbing method of rubbing the substrate with a cloth, which is used for homogeneous alignment of nematic liquid crystals, cannot obtain sufficiently good alignment. Therefore, several orientation methods different from conventional methods have been proposed. Examples include a magnetic field application method, an electric field application method, a shearing method, and a spacer edge method. However, each method has the following drawbacks. The magnetic field application method requires several to several tens of Gaussian magnetic fields, which requires a large magnetic field generator and is impractical. The electric field application method causes a current to flow through the liquid crystal molecules, causing deterioration of the liquid crystal molecules. The shearing method cannot obtain uniform orientation over a large area. The spacer-etch method makes it difficult to produce large panels.

以上、いづれの方法においても実用性の面で配向法とし
ては採用しがたい。As described above, it is difficult to adopt any of the methods as an orientation method from the viewpoint of practicality.

一方従来からのラビング法を改良した配向法も提唱され
ている。特開昭５９−１３１９１１号公報にラビング方
向を平行すなわち同方位とする試みが記載されている。On the other hand, an alignment method that is an improved version of the conventional rubbing method has also been proposed. JP-A-59-131911 describes an attempt to make the rubbing directions parallel, that is, in the same direction.

これによると、２枚のガラス基板にポリイミド樹脂を塗
布、硬化後、ラビングを行ない、しかる２枚のガラス基
板上のラビング方向を上下同一方向に平行に組み合せる
ことでカイラルスメクチック液晶の配向性が向上し、良
好なコントラスト特性が得られるとされている。According to this, the alignment of chiral smectic liquid crystal can be improved by applying polyimide resin to two glass substrates, rubbing it after curing, and then combining the rubbing directions on the two glass substrates so that they are parallel to each other in the upper and lower directions. It is said that it is possible to improve contrast characteristics.

しかしこの方法ではスメクチック液晶層が上下ガラス基
板間に垂直に形成されるのに対して、上下ガラス基板上
のラビング各々が分子層を規制するため分子層間に多く
の欠陥を生じる。However, in this method, a smectic liquid crystal layer is formed perpendicularly between the upper and lower glass substrates, whereas each rubbing on the upper and lower glass substrates restricts the molecular layers, resulting in many defects between the molecular layers.

〔発明の目的〕[Purpose of the invention]

本発明は従来技術の欠点を除去するもので、従来、実用
になっている蒸着法など、−軸性表面処理の簡便さを生
かしつつ、かつ上記欠陥の減少によりコントラス１〜特
性の上昇と信頼性の向上をはかることを目的とするもの
でおる。The present invention eliminates the drawbacks of the prior art, such as the vapor deposition method that has been in practical use, while taking advantage of the simplicity of axial surface treatment, and by reducing the defects mentioned above, increases in contrast 1 to characteristics and reliability. The purpose is to improve sexual performance.

〔発明の概要〕[Summary of the invention]

少なくとも一方を透明として相対向させた一対の基板間
に強誘電性液晶を挟持させる。これら基板の一方の液晶
に接触する面には、−軸性の水平配向処理を施し、他方
の基板の面には無軸性の水平配向処理を施して液晶素子
を構成する。ここで、無軸性の水平配向処理とは基板面
と液晶分子長軸方向が平行になる以外の分子長軸の方位
規制は行なわないことを意味する。A ferroelectric liquid crystal is sandwiched between a pair of substrates, at least one of which is transparent and opposed to each other. The surface of one of these substrates in contact with the liquid crystal is subjected to a -axis horizontal alignment treatment, and the surface of the other substrate is subjected to an axes-free horizontal alignment treatment to form a liquid crystal element. Here, the non-axial horizontal alignment process means that the orientation of the long axes of the molecules is not restricted other than to make the long axis direction of the liquid crystal molecules parallel to the substrate surface.

〔発明の実施例〕[Embodiments of the invention]

第１図は本発明の一実施例で、透明ガラスでできた２枚
の基板（１バ２）を相対向させる。各基板の対向面には
それぞれ電極（３）（４）が形成され、これら電極（３
）（４）上にはポリイミド樹脂などの配向層（５）（６
）が被着されている。下側基板（１）の配向層（５）に
は矢印（７）で示す基板に水平な一方向に、すなわら−
軸性の配向処理が施されている。上側基板（２）の配向
層（６）は矢印（８）で示すように基板面に水平でおる
が、全方向すなわち無軸性の配向処理が施されている。FIG. 1 shows an embodiment of the present invention, in which two substrates (1 and 2) made of transparent glass are opposed to each other. Electrodes (3) and (4) are formed on the opposing surfaces of each substrate, respectively.
) (4) There is an alignment layer (5) (6) made of polyimide resin etc.
) is coated. The alignment layer (5) of the lower substrate (1) has an alignment layer (5) in one direction horizontal to the substrate indicated by the arrow (7), i.e. -
Axial orientation treatment has been applied. The alignment layer (6) of the upper substrate (2) is horizontal to the substrate surface as shown by the arrow (8), but has been subjected to omnidirectional, ie, non-axial alignment treatment.

これら基板間に強誘電性液晶（９）が配向層に接して挟
持されて、液晶素子（［ｌ）が形成されている。A ferroelectric liquid crystal (9) is sandwiched between these substrates in contact with an alignment layer to form a liquid crystal element ([l).

以下、この素子の製造法について説明する。The method for manufacturing this element will be explained below.

■　第２図に示すように側基板（１）（２）の一方の面
にネサ膜でできた透明な電極（３）（４）を設けておき
、この上にポリイミド樹脂を回転速度４０００ｒｐｍの
スピンナーにより３００人厚に塗布した。続いて、一方
の基板（１）をラビングマシンにより一軸方向（７）に
ラビングし、ラビング処理を施さない他方の基板（２）
（無軸性水平配向処理になる）と一定の間隔（０，５〜
２顯）をとって貼り合せた。強誘電性液晶はＤＯＢＡ）
！ＢＣ系混合組成物を封入した。■ As shown in Figure 2, transparent electrodes (3) and (4) made of Nesa film are provided on one side of the side substrates (1 and 2), and polyimide resin is placed on top of these at a rotation speed of 4000 rpm. It was applied to a thickness of 300 mm using a spinner. Next, one substrate (1) is rubbed in a uniaxial direction (7) using a rubbing machine, and the other substrate (2) is not subjected to rubbing treatment.
(Axis-free horizontal alignment process) and a certain interval (0,5~
2) and pasted them together. Ferroelectric liquid crystal is DOBA)
! A BC-based mixed composition was enclosed.

液晶素子の上下にはラビング方向（７）から偏光軸を約
２２度ずらした偏光板（１１）とそれに偏光軸を直交す
る他の偏光板（１２）を配置した。以上の液晶素子を用
いて、コントラスト特性を測定したところ２５：１〜１
８：１で、応答性は３μ秒〜８μ秒であった。Above and below the liquid crystal element, a polarizing plate (11) whose polarizing axis was shifted by about 22 degrees from the rubbing direction (7) and another polarizing plate (12) whose polarizing axis was orthogonal to the polarizing plate (11) were arranged. Using the above liquid crystal element, the contrast characteristics were measured to be 25:1 to 1.
At 8:1, the response was between 3 μsec and 8 μsec.

■　実施例■の基板（１）（２）のうち、ラビング処理
を施した基板（１）を蒸着角度１０度でＳｉＯ斜法斜管
蒸着なった基板にかえて液晶素子を作成した。(2) Of the substrates (1) and (2) of Example (2), a liquid crystal element was prepared by replacing the rubbed substrate (1) with a substrate on which SiO was deposited using an oblique tube at a deposition angle of 10 degrees.

コントラスト特性を測定したところ、３０：１〜２２：
１、応答性は１μ秒〜４μ秒でめった。When the contrast characteristics were measured, it was 30:1 to 22:
1. Responsiveness was 1 μs to 4 μs.

■　実施例■の一対の基板のうち、ラビング処理施した
基板（１）を蒸着角度４０度でＳｉＯ斜法斜管蒸着なっ
た基板にかえて液晶素子を作成した。(2) Of the pair of substrates in Example (2), a liquid crystal element was fabricated by replacing the rubbed substrate (1) with a substrate on which SiO was deposited using an oblique tube at a deposition angle of 40 degrees.

コントラスト特性を測定したところ、２８：１〜２０：
１、応答性は２μ秒〜６μ秒であった。When the contrast characteristics were measured, it was 28:1 to 20:
1. The responsiveness was 2 μsec to 6 μsec.

以上実施例で述べたように本発明によれば、−軸性水平
配向処理と無軸性水平配向処理の組み合せにより、コン
トラスト、応答性ともにすぐれた強誘電性液晶素子を実
現することができる。As described in the embodiments above, according to the present invention, a ferroelectric liquid crystal element with excellent contrast and responsiveness can be realized by combining the -axial horizontal alignment process and the non-axial horizontal alignment process.

なお、基板は視認のため、少なくとも一方が透明でおれ
ばよく、配向層も種々のものが利用でき、強誘電性液晶
も）ＩＢＲＡ系、ＨＯＢＡＣＰＣ系など種々のものを選
べることはいうまでもない。It should be noted that at least one of the substrates needs to be transparent for visual recognition, and various alignment layers can be used, and it goes without saying that various types of ferroelectric liquid crystals can be selected, such as IBRA type, HOBACPC type, etc. .

【図面の簡単な説明】[Brief explanation of drawings]

第１図は本発明の一実施例を示す斜視図、第２図は本発
明の詳細な説明する略図である。 （１）　、−０−０下側基板、（２）・・・・・・上側
基板、（３）（４）・・・・・・電極、（５）（６）・
・・へ・・配向層、（９）・・・・・・強誘電性液晶、
（［ｌ）・・・・・・液晶素子代理人　弁理士　則　近
　憲　佑　（他１名）第　　１　図 第２図FIG. 1 is a perspective view showing one embodiment of the invention, and FIG. 2 is a schematic diagram illustrating details of the invention. (1), -0-0 lower substrate, (2)... upper substrate, (3) (4)... electrode, (5) (6).
...Orientation layer, (9)...Ferroelectric liquid crystal,
([l)...Liquid crystal device agent Patent attorney Noriyuki Chika (and 1 other person) Figure 1 Figure 2

Claims (1)

【特許請求の範囲】[Claims] 少なくとも一方が透明な一対の基板間に強誘電性液晶を
挟持させてなり、この液晶に対して前記基板の一方は一
軸性の水平配向処理が施され、他方は無軸性の水平配向
処理が施させていることを特徴とする液晶素子。A ferroelectric liquid crystal is sandwiched between a pair of substrates, at least one of which is transparent, and one of the substrates is subjected to a uniaxial horizontal alignment treatment, and the other is subjected to an aaxial horizontal alignment treatment. A liquid crystal element characterized by: