JPS6410814B2 - - Google Patents
Info
- Publication number
- JPS6410814B2 JPS6410814B2 JP2847280A JP2847280A JPS6410814B2 JP S6410814 B2 JPS6410814 B2 JP S6410814B2 JP 2847280 A JP2847280 A JP 2847280A JP 2847280 A JP2847280 A JP 2847280A JP S6410814 B2 JPS6410814 B2 JP S6410814B2
- Authority
- JP
- Japan
- Prior art keywords
- liquid crystal
- light
- display
- crystal composition
- electric field
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000004973 liquid crystal related substance Substances 0.000 claims description 33
- 230000005684 electric field Effects 0.000 claims description 16
- 239000000758 substrate Substances 0.000 claims description 14
- 239000000203 mixture Substances 0.000 claims description 12
- 239000004988 Nematic liquid crystal Substances 0.000 claims description 11
- 230000000694 effects Effects 0.000 claims description 5
- 230000001747 exhibiting effect Effects 0.000 claims 1
- 238000002834 transmittance Methods 0.000 description 8
- 239000004986 Cholesteric liquid crystals (ChLC) Substances 0.000 description 7
- 230000002159 abnormal effect Effects 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000002146 bilateral effect Effects 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 229920006284 nylon film Polymers 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 230000001902 propagating effect Effects 0.000 description 2
- 238000012935 Averaging Methods 0.000 description 1
- 239000004677 Nylon Substances 0.000 description 1
- 241000700605 Viruses Species 0.000 description 1
- 230000003098 cholesteric effect Effects 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 238000004040 coloring Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000031700 light absorption Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 229920001778 nylon Polymers 0.000 description 1
- 230000000644 propagated effect Effects 0.000 description 1
- 125000006850 spacer group Chemical group 0.000 description 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/137—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering
- G02F1/13725—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering based on guest-host interaction
Landscapes
- Physics & Mathematics (AREA)
- Nonlinear Science (AREA)
- Liquid Crystal (AREA)
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
Description
本発明は、対向する電極基板間に、二色性色素
を含む誘電異方性が正のネマチツク液晶をねじれ
ネマチツク配向させ、該電極間に電界を印加除去
する事により色素分子の配向を制御し、それに伴
う発色の変化を利用して表示を行なうゲスト・ホ
スト効果型液晶表示体に関する。
従来の誘電異方性が正のネマチツク液晶を用い
たゲスト・ホスト効果の表示原理を第１図に示
す。第１図ａは、電界無印加時の表示体の構成断
面図で、In2O3透明導電膜１を有するガラス基板
２の表面を一軸的に平行配向処理を施し、対向さ
せた間隙に、液晶４及び色素分子５は基板表面に
平行にねじれ配向している。通常用いられる層の
厚み〜10μに対して、この様な液晶層中を入射光
６は、配向方向に平行な振動成分の異常光７と配
向方向に垂直な振動成分の常光８として伝播し、
しかも、振動方向は分子のねじれ構造に追従し、
任意の位置で常光の振動方向９は色素の分子長軸
に垂直でそのため吸収を受けず、異常光の振動方
向１０は色素分子の長軸方向に平行で、強く吸収
を受ける。
このため、全体としての発色は、平均化され弱
まる。しかし、第１図ｂに示す如く、前面に直線
偏光板１３を、その透過成分の振動方向１４が入
射側電極表面１５に於ける色素分子１６の配向方
向と一致させて設置すると、吸収の強い異常光１
７のみが伝播するので非常に強く発色する。
一方、電界印加状態は、第１図ｃに示す如く、
液晶２１及び色素分子２２は、電極表面２３に垂
直に配向し、入射光２４は、任意の振動成分２５
が常光として伝播し、ほとんど透明な状態を呈す
る。
この様なゲスト・ホスト表示体の特徴を以下に
まとめると、
〔長所〕
１ 偏光板１枚を用いて高いコントラストが得ら
れる。
２ 電圧が低く3V駆動が可能
３ 鮮明なカラー表示が可能
〔短所〕
１ 偏光板無しではコントラストが低い
２ 視角依存性がある
３ 偏光板を用いると暗い
さらに、コレステリツク液晶を用いたゲスト・
ホスト表示体も知られている。しかし、このコレ
ステリツク液晶を用いたゲスト・ホスト表示体の
場合は、第４図ｂに示すように昇圧時のＶにおけ
るTupと降圧時のＶにおけるTdownとが異なる
ヒステリシスを有しており、そのためマルチプレ
ツクス駆動には不適であるという欠点を有してい
る。
本発明の目的は、この様な問題点を克服し、偏
光板無しでも高いコントラストを有し、全体に明
るい、視角依存性及びヒステリシス特性の無い表
示を達成する点にある。
以下、実施例に基づき本発明を詳しく説明す
る。第２図は本発明に基づく、Very Thin
Twisted Nematic（VTTN）ゲスト・ホスト効
果型、表示体の構成を示す。
第２図ａは、液晶層の厚み：ｄと、上下両基板
に配向方向の為す角：θが以下に述べる特異な状
態になつた時の電界無印加時の構成断面と、その
時の光の伝播の様子を示したものである。
対向するIn2O3透明電極２７の表面は互いに基
板表面での配向方向が90゜の角度を為す様、ラビ
ング処理が施されている。
その間に、表１に示すカラー液晶組成物２８を
ねじれ配向させてある。液晶層の厚みｄは、ナイ
ロン膜２９の熱圧着で2μに制御されている。
この様に2μで90゜旋回するねじれネマチツク液
晶は、構造的及び光学的には、コレステリツク液
晶のグランシヤン組織と等価で、上の場合、ラセ
ンピツチが8μに相当する。その結果入射光３０
は第１図ａの如く、常光、異常光としては伝播せ
ず、左右両旋光性の楕円偏光３１，３２となり、
両成分共、色素分子により吸収を受け３３，３４
偏光板無しでも強く発色する。
In the present invention, a nematic liquid crystal containing a dichroic dye and having a positive dielectric anisotropy is aligned in a twisted nematic manner between opposing electrode substrates, and an electric field is applied and removed between the electrodes to control the alignment of the dye molecules. This invention relates to a guest-host effect type liquid crystal display that performs display by utilizing the accompanying color change. FIG. 1 shows the principle of display of the guest-host effect using a conventional nematic liquid crystal with positive dielectric anisotropy. FIG. 1a is a cross-sectional view of the structure of the display body when no electric field is applied, in which the surface of the glass substrate 2 having the In 2 O 3 transparent conductive film 1 is subjected to uniaxial parallel alignment treatment, and in the opposing gap, The liquid crystal 4 and the dye molecules 5 are twisted and oriented parallel to the substrate surface. For a commonly used layer thickness of ~10μ, incident light 6 propagates in such a liquid crystal layer as extraordinary light 7 with a vibrational component parallel to the orientation direction and ordinary light 8 with a vibrational component perpendicular to the orientation direction.
Moreover, the vibration direction follows the twisted structure of the molecule,
At any given position, the vibration direction 9 of the ordinary light is perpendicular to the long axis of the dye molecule and is therefore not absorbed, and the vibration direction 10 of the extraordinary light is parallel to the long axis of the dye molecule and is strongly absorbed. Therefore, the overall color development is averaged and weakened. However, as shown in FIG. 1b, if a linear polarizing plate 13 is installed in front so that the vibration direction 14 of the transmitted component matches the alignment direction of the dye molecules 16 on the incident side electrode surface 15, strong absorption occurs. Abnormal light 1
Since only 7 is propagated, the color is very strong. On the other hand, the electric field application state is as shown in Fig. 1c.
The liquid crystal 21 and the dye molecules 22 are aligned perpendicularly to the electrode surface 23, and the incident light 24 has an arbitrary vibrational component 25.
propagates as ordinary light and appears almost transparent. The characteristics of such a guest-host display are summarized below: [Advantages] 1. High contrast can be obtained using a single polarizing plate. 2 Low voltage and can be driven at 3V 3 Clear color display possible [Disadvantages] 1 Low contrast without a polarizing plate 2 Viewing angle dependent 3 Dark when using a polarizing plate In addition, guest display using cholesteric liquid crystal
Host indicators are also known. However, in the case of a guest-host display using this cholesteric liquid crystal, as shown in FIG. It has the disadvantage that it is unsuitable for traction drive. An object of the present invention is to overcome these problems and to achieve a display that has high contrast even without a polarizing plate, is bright overall, and is free from viewing angle dependence and hysteresis characteristics. Hereinafter, the present invention will be explained in detail based on Examples. Figure 2 shows a Very Thin model based on the present invention.
Twisted Nematic (VTTN) guest-host effect type, showing the structure of the display body. Figure 2a shows the cross section of the configuration when no electric field is applied when the thickness of the liquid crystal layer: d and the angle θ between the alignment directions on both the upper and lower substrates reach the peculiar state described below, and the light beam at that time. This shows how the virus spreads. The surfaces of the In 2 O 3 transparent electrodes 27 facing each other are subjected to a rubbing treatment so that their orientation directions on the substrate surface form an angle of 90 degrees. During this time, the color liquid crystal composition 28 shown in Table 1 was twisted and oriented. The thickness d of the liquid crystal layer is controlled to 2μ by thermocompression bonding of the nylon film 29. A twisted nematic liquid crystal that rotates 90 degrees at 2 μ in this way is structurally and optically equivalent to the gransian structure of a cholesteric liquid crystal, and in the above case, the helical pitch corresponds to 8 μ. As a result, the incident light 30
As shown in Figure 1a, the light does not propagate as ordinary light or extraordinary light, but becomes elliptically polarized light 31 and 32 with bilateral optical rotation,
Both components are absorbed by dye molecules33,34
Strong coloring even without a polarizing plate.
【表】
一方、第２図ｂは、電界印加状態の構成断面図
を示し、液晶及び色素分子は、第１図ｃと全く同
様透明状態になる。
次に、本発明に基づくVTTN―ゲスト・ホス
ト効果を説明する。ねじれネマチツク液晶中の光
の伝播は、光の波長λと、ねじれ構造のピツチ：
Ｐ、液晶分子の主屈折率n‖＞n⊥（n‖は液晶分
子の長軸方向に偏光した光に対する屈折率、n⊥
は液晶分子の長軸に垂直方向に偏光した光に対す
る屈折率を示す）により特徴づけられ、液晶中の
色素の光吸収、即ち表示体とした際のコントラス
トを決定する。
第３図は、次式で与えられるラセンピツチに対
する換算波長：γと、
γ＝√２・λ／Ｐ√‖2＋⊥2 (1)
電界無印加状態の透過率Toffの関係を示す。
（但し、電界印加状の透過率Tonは一定値、70％
に設定してある）。図から明らかな如く、γの増
加と共に、Toffは徐々に減少し、0.86では12.4
％、コントラストとして約5.6を与える。一般に
抜けた状態の透過率を70％とした時、暗い状態の
透過率は20〜25％は必要で、その際の条件として
は、γ0.03である。ねじれネマチツク表示体に
於けるラセン構造のピツチ：Ｐは、上下基板表面
での配向方向のなす角θ（ラジアン）と、液晶層
の厚み：ｄで決まり、次式で与えられる。
Ｐ＝2πd／θ (2)
これより、換算波長γを大きい値で得るために
は、ピツチＰは小さい方が望ましいことがいえ
る。そして、ピツチＰを小さくするにはθが大き
い程、一定のｄに対しＰを小さくできるのであ
る。
次に、(1)式に(2)式を代入して次の式を得る。
そして、前述したようにγ0.03が良好なコン
トラストを得る上での条件となるので次式のよう
になる。
ここで、光の波長λを中心波長の0.6μとしたと
き、(4)式より液晶層の厚みｄは次式により決定さ
れることが導き出される。
又、θは前述したように、大きい程望ましいわ
けであるが、液晶表示体として製造する場合には
次のような理由からπ／４｜θ｜π／２が好
ましい。即ち、本発明に用いたネマチツク液晶自
体にはねじれ力が無く、基板界面の配向処理によ
る配向力を用いてねじれ配向させているので、ド
メイン等の発生を防ぐため、｜θ｜π／２が良
いのである。又、θを小さくするとｄも小さくし
ないといけなくなる。表２に、本発明による実施
例及び比較例を示す。尚、前述の表１に示す液晶
組成物を用いた本実施例はNo.３である。この表２
（No.５）より明らかなように、θをπ／４とした
場合γが0.03以上の値となるｄは1μとなる。
さらに、θが小さくなると、ｄは1μ未満にし
なくてはいけない、しかしこのように非常に薄い
ｄを精度良く製造することはきわめて困難であ
り、せいぜい1μが限界と思われる。従つて、θ
の下限はπ／４が望ましいものである。[Table] On the other hand, FIG. 2b shows a cross-sectional view of the structure in a state where an electric field is applied, and the liquid crystal and dye molecules are in a transparent state exactly as in FIG. 1c. Next, the VTTN-guest-host effect according to the present invention will be explained. The propagation of light in a twisted nematic liquid crystal depends on the wavelength λ of the light and the pitch of the twisted structure:
P, principal refractive index of liquid crystal molecules n‖>n⊥ (n‖ is the refractive index for light polarized in the long axis direction of liquid crystal molecules, n⊥
(indicates the refractive index for light polarized perpendicular to the long axis of the liquid crystal molecules), which determines the light absorption of the dye in the liquid crystal, that is, the contrast when used as a display. FIG. 3 shows the relationship between the converted wavelength γ for the helical pitch given by the following equation and the transmittance Toff in a state where no electric field is applied.
(However, the transmittance Ton when an electric field is applied is a constant value, 70%.
). As is clear from the figure, as γ increases, Toff gradually decreases, and at 0.86 it is 12.4
%, giving about 5.6 as contrast. Generally, when the transmittance in the clear state is 70%, the transmittance in the dark state must be 20 to 25%, and the condition for this is γ0.03. The pitch P of the helical structure in a twisted nematic display is determined by the angle θ (radian) between the orientation directions on the surfaces of the upper and lower substrates and the thickness d of the liquid crystal layer, and is given by the following equation. P=2πd/θ (2) From this, it can be said that in order to obtain a large value for the converted wavelength γ, it is desirable that the pitch P be small. In order to reduce the pitch P, the larger θ is, the smaller P can be made for a constant d. Next, substitute equation (2) into equation (1) to obtain the following equation. As mentioned above, γ0.03 is a condition for obtaining good contrast, so the following equation is obtained. Here, when the wavelength λ of light is set to the center wavelength of 0.6μ, it is derived from equation (4) that the thickness d of the liquid crystal layer is determined by the following equation. Further, as described above, the larger θ is, the more desirable it is, but when manufacturing a liquid crystal display, π/4|θ|π/2 is preferable for the following reasons. That is, the nematic liquid crystal used in the present invention itself has no twisting force, and is twisted and oriented using the alignment force generated by the alignment treatment at the substrate interface. Therefore, in order to prevent the occurrence of domains, |θ|π/2 is It's good. Furthermore, if θ is made smaller, d must also be made smaller. Table 2 shows examples according to the present invention and comparative examples. The present example using the liquid crystal composition shown in Table 1 above is No. 3. This table 2
As is clear from (No. 5), when θ is set to π/4, d for which γ is a value of 0.03 or more is 1μ. Furthermore, as θ becomes smaller, d must be less than 1μ, but it is extremely difficult to manufacture such a very thin d with high precision, and 1μ seems to be the limit at most. Therefore, θ
The lower limit of is preferably π/4.
【表】
第４図ａに、表１に示す液晶組成物を90゜の配
向方向にねじれ配向し、液晶層の厚みを2μとし
た本実施例の電圧―透過率特性を示す。参考のた
めに、直線偏光として伝播するθ＝０の場合を波
線４１で示し、θ＝π／２の場合を実線４２で示
す。図から明らかな如く、同一厚み、同一色素濃
度にもかかわらずθ＝π／２の場合の方が電圧０
での発色が強く、結果として高いコントラストが
得られる。
又、第４図ｂには、コレステリツク液晶を用い
たゲスト・ホスト表示体の透過率―電圧特性を示
す。本発明に基づくVTTN―表示体は、構造的
にも光学的にも、コレステリツク液晶と等価であ
るが、電気光学特性に大きな違いがある。即ちコ
レステリツクの場合、昇圧時のＶに於けるTupと
降圧時のＶに於けるTdownとが異なるヒステリ
シスを有するのに対し、VTTN―表示体は、そ
の様なヒステリシスを示さないからである。
以上の実施例からも明らかな如く、本発明に基
づくVTTN―ゲスト・ホスト表示体は、偏光板
無しでも、従来のゲスト表示体の倍のコントラス
トを与え、明るく見易い表示を提供するものであ
る。
又、従来、コレステリツク液晶を用いたゲスト
ホスト表示体はヒステリシスのために、使用でき
る点灯状態Vonと非点灯状態Voffの電圧比
Von／Voffが大きく、電圧平均化法によるマル
チプレツクス駆動に不向きとされているが、
VTTN―表示体はヒステリシスが無いために、
マルチプレツクス駆動に適している。
上述の如く、本発明によれば、まず二色性色素
を含む液晶組成物としてネマチツク液晶組成物を
用いたので、透過率―電圧特性においてヒステリ
シスを示さない。よつて、マルチプレツクス駆動
に適している。さらに、前記ネマチツク液晶組成
物自体にはねじれ力が無いために、上下基板界面
の配向処理によりねじれ配向させているものであ
る。また、このネマチツク液晶組成物のねじれに
ついては、上下基板の配向方向のなす角度θを
π／４｜θ｜π／２としたので、ドメイン等の発生
もなく基板界面の配向力のみで安定したねじれ状
態を得られるのである。そして、前記θにおい
て、液晶層の厚みｄが前記した式を満足すること
により、電界無印加時に液晶層を伝播する光が左
右両旋光性の楕円偏光を生じるのである。この楕
円偏光が、液晶層中の二色性色素により両成分共
強く吸収されるため、電界印加時の透明状態との
透過率の差が大きく、コントラストの高い表示が
実現できるものである。[Table] FIG. 4a shows the voltage-transmittance characteristics of this example in which the liquid crystal composition shown in Table 1 was twisted in the alignment direction at 90° and the thickness of the liquid crystal layer was 2 μm. For reference, the case where θ=0 propagating as linearly polarized light is shown by a broken line 41, and the case where θ=π/2 is shown by a solid line 42. As is clear from the figure, the voltage is 0 when θ=π/2, despite the same thickness and dye density.
The colors are strong and the result is high contrast. FIG. 4b shows the transmittance-voltage characteristics of a guest-host display using cholesteric liquid crystal. The VTTN display according to the invention is structurally and optically equivalent to a cholesteric liquid crystal, but there are significant differences in the electro-optical properties. That is, in the case of cholesteric, Tup in V when the voltage is increased and Tdown in V when the voltage is decreased have different hysteresis, whereas the VTTN-display body does not show such hysteresis. As is clear from the above examples, the VTTN-guest/host display according to the present invention provides twice the contrast of the conventional guest display and provides a bright and easy-to-see display even without a polarizing plate. In addition, conventional guest-host displays using cholesteric liquid crystals have hysteresis, which limits the voltage ratio between the usable lighting state Von and the non-lighting state Voff.
Von/Voff is large and is considered unsuitable for multiplex drive using voltage averaging method.
VTTN - Since the display has no hysteresis,
Suitable for multiplex drive. As described above, according to the present invention, first, a nematic liquid crystal composition is used as a liquid crystal composition containing a dichroic dye, so that the transmittance-voltage characteristic does not exhibit hysteresis. Therefore, it is suitable for multiplex drive. Furthermore, since the nematic liquid crystal composition itself has no twisting force, it is twisted and oriented by alignment treatment at the interface between the upper and lower substrates. Furthermore, regarding the twisting of this nematic liquid crystal composition, since the angle θ between the alignment directions of the upper and lower substrates was set to π/4|θ|π/2, no domains were generated and the composition was stabilized only by the alignment force at the substrate interface. A twisted state can be obtained. When the thickness d of the liquid crystal layer satisfies the above-mentioned formula at the angle θ, the light propagating through the liquid crystal layer when no electric field is applied generates elliptically polarized light with bilateral optical rotation. Since both components of this elliptically polarized light are strongly absorbed by the dichroic dye in the liquid crystal layer, there is a large difference in transmittance from the transparent state when an electric field is applied, and a display with high contrast can be realized.
第１図ａは電界無印加時の誘電異方性が正のネ
マチツク液晶を用いだゲスト・ホスト表示体の構
成断面図である。
１……透明電極、２……ガラス基板、３……ナ
イロン膜、４……液晶、５……色素分子、６……
入射光、７……分子軸に平行な振動成分、８……
分子軸に垂直な振動成分、９……常光線、１０…
…異常光線、１１……吸収を受けない常光線、１
２……吸収を受けた異常光線。
第１図ｂは、偏光板を具備したゲスト・ホスト
表示体の構成断面図である。
１３……直線偏光板、１４……通光性振動方
向、１５……透明電極、１６……色素分子、１
７，１８……入射光、１９，２０……異常光線。
第１図ｃは、電界印加状態の構成断面図であ
る。
２１……液晶、２２……色素分子、２３……透
明電極、２４……入射光、２５，２６……光の振
動方向。
第２図ａは、VTTN表示体の電界無印加状態
での構成断面図を示す。
２７……透明電極、２８……ねじれ液晶、２９
……ナイロンスペーサー、３０……入射光、３１
……右旋性楕円偏光、３２……左旋性楕円偏光、
３３，３４……吸収を受けた楕円偏光。
第２図ｂは、VTTN表示体の電界印加状態で
の構成断面図を示す。
３５……入射光、３６，３７……光の振動方
向。
第３図は、電界印加状態の透過率Tonを一定に
した時の還算波長γと、電界無印加状態の透過率
Toffの関係を示す図。
３９……Ton、４０……Toff。
第４図ａは、VTTN―ゲスト・ホスト表示体
の電気光学特性を示す図。
４１……θ＝０、４２……θ＝π／２。
第４図ｂは、コレステリツク液晶を用いた場合
の電気光学特性を示す図。
FIG. 1a is a sectional view of a guest-host display using a nematic liquid crystal having positive dielectric anisotropy when no electric field is applied. 1...Transparent electrode, 2...Glass substrate, 3...Nylon film, 4...Liquid crystal, 5...Dye molecule, 6...
Incident light, 7... Vibration component parallel to the molecular axis, 8...
Vibration component perpendicular to the molecular axis, 9... Ordinary ray, 10...
...Extraordinary ray, 11...Ordinary ray that does not undergo absorption, 1
2... Abnormal ray that has been absorbed. FIG. 1b is a sectional view of the structure of a guest-host display body equipped with a polarizing plate. 13... Linear polarizing plate, 14... Light transmitting vibration direction, 15... Transparent electrode, 16... Dye molecule, 1
7, 18...incident light, 19,20...abnormal ray. FIG. 1c is a cross-sectional view of the structure when an electric field is applied. 21... Liquid crystal, 22... Dye molecule, 23... Transparent electrode, 24... Incident light, 25, 26... Vibration direction of light. FIG. 2a shows a cross-sectional view of the structure of the VTTN display in a state where no electric field is applied. 27...Transparent electrode, 28...Twisted liquid crystal, 29
... Nylon spacer, 30 ... Incident light, 31
... Right-handed elliptically polarized light, 32... Left-handed elliptically polarized light,
33, 34...Elliptically polarized light that has undergone absorption. FIG. 2b shows a cross-sectional view of the structure of the VTTN display in a state where an electric field is applied. 35... Incident light, 36, 37... Vibration direction of light. Figure 3 shows the reduced wavelength γ when the transmittance Ton is kept constant when an electric field is applied, and the transmittance when no electric field is applied.
A diagram showing the relationship between Toff. 39...Ton, 40...Toff. FIG. 4a is a diagram showing the electro-optical characteristics of the VTTN-guest-host display. 41...θ=0, 42...θ=π/2. FIG. 4b is a diagram showing electro-optical characteristics when cholesteric liquid crystal is used.
Claims (1)
晶組成物を介在させ、電界の印加除去に伴う発色
の変化を利用して表示を行うゲストホスト効果型
の液晶表示体において、前記二色性色素を含む液
晶組成物が正の誘電異方性を示すネマチツク液晶
組成物であり、該ネマチツク液晶組成物は前記上
下基板界面の配向処理によりねじれ配向され且つ
前記上下基板の配向方向のなす角度θが π／４｜θ｜π／２であり、光の中心波長を0.6
μ としたとき液晶層の厚みｄが下式を満足する値と
なるようにすることを特徴とする液晶表示体。 〔ただしθは上下基板の配向方向のなす角度、
n11は液晶分子の長軸方向に偏光した光に対する
屈折率、n⊥は液晶分子の長軸に垂直方向に偏光
した光に対する屈折率を示す〕。[Scope of Claims] 1. A guest-host effect type liquid crystal display in which a liquid crystal composition containing a dichroic dye is interposed between opposing upper and lower substrates, and display is performed by utilizing changes in color development as an electric field is applied and removed. In the body, the liquid crystal composition containing the dichroic dye is a nematic liquid crystal composition exhibiting positive dielectric anisotropy, and the nematic liquid crystal composition is twisted and oriented by the alignment treatment of the upper and lower substrate interfaces, and The angle θ formed by the orientation direction of is π/4 | θ | π/2, and the center wavelength of light is 0.6
A liquid crystal display body characterized in that the thickness d of the liquid crystal layer is set to a value satisfying the following formula, where μ is the thickness d of the liquid crystal layer. [However, θ is the angle formed by the orientation direction of the upper and lower substrates,
n 11 is the refractive index for light polarized in the direction of the long axis of the liquid crystal molecules, and n⊥ is the refractive index for light polarized in the direction perpendicular to the long axis of the liquid crystal molecules].
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2847280A JPS56125723A (en) | 1980-03-06 | 1980-03-06 | Liquid crystal display |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2847280A JPS56125723A (en) | 1980-03-06 | 1980-03-06 | Liquid crystal display |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS56125723A JPS56125723A (en) | 1981-10-02 |
| JPS6410814B2 true JPS6410814B2 (en) | 1989-02-22 |
Family
ID=12249585
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2847280A Granted JPS56125723A (en) | 1980-03-06 | 1980-03-06 | Liquid crystal display |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS56125723A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4596446B2 (en) * | 1982-06-29 | 1997-03-18 | Secr Defence Brit | Liquid crystal devices with particular cholestric pitch-cell thickness ratio |
| EP0098070B2 (en) * | 1982-06-29 | 2000-12-13 | The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and | Liquid crystal devices |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5279948A (en) * | 1975-12-25 | 1977-07-05 | Sharp Corp | Liquid crystal color display device |
-
1980
- 1980-03-06 JP JP2847280A patent/JPS56125723A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS56125723A (en) | 1981-10-02 |
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