JP2003172925A - Liquid crystal display device - Google Patents

Liquid crystal display device

Info

Publication number
JP2003172925A
JP2003172925A JP30826699A JP30826699A JP2003172925A JP 2003172925 A JP2003172925 A JP 2003172925A JP 30826699 A JP30826699 A JP 30826699A JP 30826699 A JP30826699 A JP 30826699A JP 2003172925 A JP2003172925 A JP 2003172925A
Authority
JP
Japan
Prior art keywords
liquid crystal
plate
phase difference
crystal element
display device
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.)
Pending
Application number
JP30826699A
Other languages
Japanese (ja)
Inventor
Toru Yamaguchi
徹 山口
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Citizen Watch Co Ltd
Original Assignee
Citizen Watch Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Citizen Watch Co Ltd filed Critical Citizen Watch Co Ltd
Priority to JP30826699A priority Critical patent/JP2003172925A/en
Priority to PCT/JP2000/007629 priority patent/WO2001031391A1/en
Publication of JP2003172925A publication Critical patent/JP2003172925A/en
Pending legal-status Critical Current

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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
    • G02F1/139—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 orientation effects in which the liquid crystal remains transparent
    • G02F1/1396—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 orientation effects in which the liquid crystal remains transparent the liquid crystal being selectively controlled between a twisted state and a non-twisted state, e.g. TN-LC cell
    • 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
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/13363—Birefringent elements, e.g. for optical compensation
    • 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
    • G02F2203/00—Function characteristic
    • G02F2203/02—Function characteristic reflective

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  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • Liquid Crystal (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Polarising Elements (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device wherein reflection display by external light and transmission display by backlight illumination are both made possible and high contrast can be obtained in both the reflection display and the transmission display, in a liquid crystal display device of a single polarizing plate system on which only one polarizing plate is mounted. <P>SOLUTION: The liquid crystal display device has a first polarizing plate 11, a twisted optical retardation plate 12, a liquid crystal element 21 inhering a semitransmission reflection layer 9, a first optical retardation plate 17, a second polarizing plate 16 and a backlight 15. The ratio Tc/Ts of the twist angle Tc of the twisted optical retardation plate 12 to the twist angle Ts of the liquid crystal element is in the range of 0.7 to 0.8, the difference Rs-Rc between the Δnd value Rs of the liquid crystal element and the Δnd value Rc of the twisted optical retardation plate 12 is in the range of 0.1 to 0.15 μm, a disposition angle α of the twisted optical retardation plate 12 is in the range of 80 to 100° and a disposition angle β of the first polarizing plate 11 is in the range of 60 to 75°. <P>COPYRIGHT: (C)2003,JPO

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【発明の属する技術分野】本発明は液晶表示装置の構成
に関し、とくに液晶表示素子内部の反射板と１枚の偏光
板で構成し、明るい白黒表示やカラー表示を実現する単
偏光板方式の反射型液晶表示装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a liquid crystal display device, and in particular, a single-polarizer type reflection device for realizing a bright black-and-white display and a color display, which is composed of a reflection plate inside a liquid crystal display element and one polarizing plate. Type liquid crystal display device.

【０００２】[0002]

【従来の技術】従来、反射型液晶表示装置は、１対の偏
光板と、一方の偏光板の外側に配置した反射層の間に、
ＴＮ（ツイステッドネマティック）液晶素子や、ＳＴＮ
（スーパーツイステッドネマチック）液晶素子を設けた
反射型液晶表示装置が主に用いられている。しかしなが
ら、この方式では明るさが低く、さらに、反射層がガラ
ス基板の外側にあるので、表示に影が生じるという問題
がある。2. Description of the Related Art Conventionally, a reflective liquid crystal display device includes a pair of polarizing plates and a reflective layer disposed outside one polarizing plate.
TN (Twisted Nematic) liquid crystal element and STN
A reflection type liquid crystal display device provided with a (super twisted nematic) liquid crystal element is mainly used. However, this method has a problem that the brightness is low and the display has a shadow because the reflective layer is outside the glass substrate.

【０００３】上記の対策として、偏光板１枚で表示が可
能な単偏光板方式の反射型液晶表示装置が提案されてい
る。偏光板が１枚であるために、従来の偏光板を２枚用
いる反射型液晶表示装置より、明るさを改善することが
できる。As a countermeasure against the above problem, a reflection type liquid crystal display device of a single polarizing plate type has been proposed which is capable of displaying with one polarizing plate. Since the number of polarizing plates is one, the brightness can be improved as compared with the conventional reflective liquid crystal display device using two polarizing plates.

【０００４】また、単偏光板方式液晶表示装置では、反
射層を液晶表示素子内部に形なすることで、表示の影の
問題も解決することが可能である。Further, in the single polarizing plate type liquid crystal display device, the problem of the shadow of the display can be solved by forming the reflection layer inside the liquid crystal display element.

【０００５】この単偏光板方式液晶表示装置は、１枚の
偏光板と、１枚の位相差板と、反射層を内在した液晶素
子とから構成され、たとえば特開平４−９７１２１号公
報に開示されている。This single polarizing plate type liquid crystal display device is composed of one polarizing plate, one retardation plate, and a liquid crystal element having a reflective layer therein, and is disclosed in, for example, Japanese Patent Laid-Open No. 4-97121. Has been done.

【０００６】[0006]

【発明が解決しようとする課題】しかし、前述した位相
差板を１枚用いた単偏光板方式液晶表示装置では、特定
の波長に対してのみ低い反射率が実現され、すべての波
長にわたり低い反射率を実現することはできない。However, in the single polarizing plate type liquid crystal display device using one retardation plate described above, a low reflectance is realized only for a specific wavelength, and a low reflectance over all wavelengths. The rate cannot be realized.

【０００７】そこで、良好な黒表示を得るために、位相
差板を２枚用いた単偏光板方式液晶表示装置も開発され
ているが、まだ、充分なコントラストは得られていな
い。Therefore, in order to obtain a good black display, a single polarizing plate type liquid crystal display device using two retardation plates has been developed, but a sufficient contrast has not been obtained yet.

【０００８】また、位相差板の代わりに、液晶層のねじ
れ方向と逆方向にねじれた構造を持つ補償層を用いた単
偏光板方式液晶表示装置も開発されており、たとえば特
開平８−７６１１１号公報に開示されている。Further, a single polarizing plate type liquid crystal display device using a compensation layer having a structure twisted in a direction opposite to the twist direction of the liquid crystal layer has been developed in place of the retardation plate, for example, Japanese Patent Laid-Open No. 8-76111. It is disclosed in the publication.

【０００９】しかしながら、この公報においては、まず
電圧無印可時の表示が白で、電圧印加時の表示が黒とな
る、いわゆるノーマリー白表示であるので、電圧を印加
した状態での補償が難しく、良好な黒が得られず、さら
に画素間から光が漏れるために、高いコントラストは得
られない。However, in this publication, since the display when the voltage is not applied is white and the display when the voltage is applied is black, that is, the so-called normally white display, it is difficult to compensate in the state where the voltage is applied. High black cannot be obtained because good black cannot be obtained and light leaks from between the pixels.

【００１０】またさらに、この公報においては、液晶素
子に対するねじれ位相差板のツイスト角、Δｎｄ、配置
角についての詳細な記載が無いため、最適な反射型液晶
表示装置としての構成を得ることができない。Further, in this publication, since the twist angle, Δnd, and arrangement angle of the twisted phase difference plate with respect to the liquid crystal element are not described in detail, it is impossible to obtain an optimum reflection type liquid crystal display device. .

【００１１】また、さきの従来技術の単偏光板方式液晶
表示装置において、反射層は光を透過しないので、バッ
クライトを設けることができず、外光が弱い場所や夜間
には表示を見ることができなかった。Further, in the prior art single polarizing plate type liquid crystal display device, since the reflection layer does not transmit light, a backlight cannot be provided and the display can be seen in a place where the external light is weak or at night. I couldn't.

【００１２】そこで、反射層として薄膜アルミニウムを
蒸着したハーフミラーを用いたり、反射層に画素毎の開
口部を設け、外光が弱い場所や夜間にはバックライトの
光で表示を行う半透過反射型の液晶表示装置が開発され
ている。[0012] Therefore, a semi-transmissive reflection is used in which a half mirror having thin film aluminum vapor-deposited is used as a reflection layer, or an opening for each pixel is provided in the reflection layer, and display is performed by backlight light at a place where external light is weak or at night. Type liquid crystal display devices have been developed.

【００１３】しかし、単偏光板方式液晶表示装置の場
合、外光を用いる反射表示時は、偏光板が１枚しかな
く、入射光は液晶素子を往復した状態で良好な黒白表示
が可能な様に液晶素子や位相差板等の光学素子を設計す
る必要がある。However, in the case of a single-polarizer type liquid crystal display device, there is only one polarizing plate in the reflective display using external light, and it is possible to obtain a good black and white display with the incident light reciprocating through the liquid crystal element. Therefore, it is necessary to design an optical element such as a liquid crystal element or a retardation plate.

【００１４】一方、バックライトを用いた透過表示時
は、液晶素子を１回しか透過せず、この状態で良好な黒
白表示が得られる様に液晶素子や光学素子を設計する必
要があり、反射表示と透過表示ともに高コントラストを
得ることは難しかしい。On the other hand, during transmissive display using a backlight, it is necessary to design the liquid crystal element and the optical element so that the liquid crystal element transmits only once and a good black and white display can be obtained in this state. It is difficult to obtain high contrast in both display and transmissive display.

【００１５】反射層に画素毎の開口部を設けた液晶表示
装置としては、たとえば特開平１０−２８２４８８号公
報に開示されているが、この公報には、液晶素子や光学
素子の条件に関する記述は一切なく、反射表示時と透過
表示時でいかにして良好なコントラスト表示を両立させ
るかは記載されていない。A liquid crystal display device having an opening for each pixel in a reflective layer is disclosed in, for example, Japanese Patent Application Laid-Open No. 10-28248. However, this publication describes the conditions of liquid crystal elements and optical elements. None of them describes how to achieve good contrast display at the time of both reflective display and transmissive display.

【００１６】〔発明の目的〕本発明の第１の目的は、前
記従来技術の課題を解決し、外光による反射表示におい
て、液晶素子に対するねじれ位相差板のツイスト角、Δ
ｎｄ、配置角を最適化し、さらにねじれ位相差板に対す
る偏光板の配置角を最適化し、さらに液晶素子のΔｎｄ
値の範囲を限定することにより、ノーマリー黒モード
で、低い反射率の黒を得ることで、高コントラストで、
かつ、明るい反射型の液晶表示装置を提供することであ
る。[0016] The first object of the present invention is to solve the above-mentioned problems of the prior art, and in the reflective display by external light, the twist angle of the twisted phase difference plate with respect to the liquid crystal element, Δ
nd, the arrangement angle is optimized, and further, the arrangement angle of the polarizing plate with respect to the twisted phase difference plate is optimized.
By limiting the range of values, it is possible to obtain black with low reflectance in the normally black mode, and with high contrast,
Another object of the present invention is to provide a bright reflective liquid crystal display device.

【００１７】また、本発明の第２の目的は、外光による
反射表示と、バックライト照明による透過表示が可能
で、かつ、反射表示と透過表示の両方で高コントラスト
が得られる単偏光板方式の半透過反射型の液晶表示装置
を提供することである。A second object of the present invention is a single polarizing plate system capable of performing reflective display by external light and transmissive display by backlight illumination, and obtaining high contrast in both reflective display and transmissive display. Another object of the present invention is to provide a transflective liquid crystal display device.

【００１８】[0018]

【課題を解決するための手段】上記目的を達成するため
に、本発明の液晶表示装置は、反射層と第１の電極を有
する第１の基板と第２の電極を有する第２の基板と前記
１対の基板の間にツイスト角が１８０〜２６０゜にツイ
スト配向しているネマチック液晶を狭持してなる液晶素
子と、前記第２の基板の外側に設けるねじれ位相差板
と、ねじれ位相差板の外側に設ける第１の偏光板とを備
え、前記ねじれ位相差板のツイスト方向は前記液晶素子
と逆ねじれ構造であり、前記液晶素子の上液晶分子配向
方向と前記ねじれ位相差板の下分子配向方向とのなす角
度αが８０〜１００゜であり、前記第１の偏光板の透過
軸と前記ねじれ位相差板の上分子配向方向とのなす角度
βが６０〜７５゜であり、前記ねじれ位相差板のツイス
ト角Ｔｃは前記液晶素子のツイスト角Ｔｓの０．７〜
０．８倍であり、前記ねじれ位相差板の複屈折量を示す
Δｎｄ値Ｒｃは前記液晶素子のΔｎｄ値Ｒｓより０．１
〜０．１５μｍ小さいことを特徴とする。To achieve the above object, a liquid crystal display device of the present invention comprises a first substrate having a reflective layer and a first electrode, and a second substrate having a second electrode. A liquid crystal element sandwiching a nematic liquid crystal having a twist angle of 180 to 260 ° between the pair of substrates, a twisted phase difference plate provided outside the second substrate, and a twisted position. A twisting direction of the twisted phase difference plate has a reverse twist structure with the liquid crystal element, and a first polarizing plate provided on the outside of the phase difference plate, The angle α formed by the lower molecular orientation direction is 80 to 100 °, and the angle β formed by the transmission axis of the first polarizing plate and the upper molecular orientation direction of the twisted phase difference plate is 60 to 75 °, The twist angle Tc of the twisted phase difference plate is equal to the liquid crystal element. Child twist angle Ts 0.7-
0.8 times, and the Δnd value Rc indicating the birefringence amount of the twisted phase difference plate is 0.1 from the Δnd value Rs of the liquid crystal element.
It is characterized by being smaller by 0.15 μm.

【００１９】また、本発明の液晶表示装置は、半透過反
射層と第１の電極を有する第１の基板と第２の電極を有
する第２の基板と前記１対の基板の間にツイスト角が１
８０〜２６０゜にツイスト配向しているネマチック液晶
を狭持してなる液晶素子と、前記第２の基板の外側に設
けるねじれ位相差板と、ねじれ位相差板の外側に設ける
第１の偏光板と、前記第１の基板の外側に設ける第１の
位相差板と、第１の位相差板の外側に設ける第２の偏光
板と、第２の偏光板の外側に設けるバックライトとを備
え、前記ねじれ位相差板のツイスト方向は前記液晶素子
と逆ねじれ構造であり、前記液晶素子の上液晶分子配向
方向と前記ねじれ位相差板の下分子配向方向とのなす角
度αが８０〜１００゜であり、前記第１の偏光板の透過
軸と前記ねじれ位相差板の上分子配向方向とのなす角度
βが６０〜７５゜であり、前記ねじれ位相差板のツイス
ト角Ｔｃは液晶素子のツイスト角Ｔｓの０．７〜０．８
倍であり、前記ねじれ位相差板の複屈折量を示すΔｎｄ
値Ｒｃは液晶素子のΔｎｄ値Ｒｓより０．１〜０．１５
μｍ小さいことを特徴とする。Further, in the liquid crystal display device of the present invention, a twist angle is formed between the first substrate having the semi-transmissive reflective layer and the first electrode, the second substrate having the second electrode, and the pair of substrates. Is 1
A liquid crystal element sandwiching a nematic liquid crystal having a twist orientation of 80 to 260 °, a twisted phase difference plate provided outside the second substrate, and a first polarizing plate provided outside the twisted phase difference plate. A first retardation plate provided outside the first substrate, a second polarizing plate provided outside the first retardation plate, and a backlight provided outside the second polarizing plate. The twist direction of the twisted phase difference plate has a reverse twisted structure with respect to the liquid crystal element, and an angle α between an upper liquid crystal molecule alignment direction of the liquid crystal element and a lower molecule alignment direction of the twisted phase difference plate is 80 to 100 °. And the angle β between the transmission axis of the first polarizing plate and the upper molecular orientation of the twisted phase difference plate is 60 to 75 °, and the twist angle Tc of the twisted phase difference plate is the twist of the liquid crystal element. Angle Ts 0.7 to 0.8
Δnd indicating the birefringence amount of the twisted phase plate
The value Rc is 0.1 to 0.15 from the Δnd value Rs of the liquid crystal element.
It is characterized by being small by μm.

【００２０】また、本発明の液晶表示装置は、半透過反
射層と第１の電極を有する第１の基板と第２の電極を有
する第２の基板と前記１対の基板の間にツイスト角が１
８０〜２６０゜にツイスト配向しているネマチック液晶
を狭持してなる液晶素子と、前記第２の基板の外側に設
けるねじれ位相差板と、ねじれ位相差板の外側に設ける
第１の偏光板と、前記第１の基板の外側に設ける第１の
位相差板と、第１の位相差板の外側に設ける第２の位相
差板と、第２の位相差板の外側に設ける第２の偏光板
と、第２の偏光板の外側に設けるバックライトとを備
え、前記第１の位相差板の遅相軸と前記第２の位相差板
の遅相軸は概ね６０゜に交差しており、第１の位相差板
の位相差値は概ね１／４波長で、第２の位相差板の位相
差値が概ね１／２波長であり、前記ねじれ位相差板のツ
イスト方向は前記液晶素子と逆ねじれ構造であり、前記
液晶素子の上液晶分子配向方向と前記ねじれ位相差板の
下分子配向方向とのなす角度αが８０〜１００゜であ
り、前記第１の偏光板の透過軸と前記ねじれ位相差板の
上分子配向方向とのなす角度βが６０〜７５゜であり、
前記ねじれ位相差板のツイスト角Ｔｃは前記液晶素子の
ツイスト角Ｔｓの０．７〜０．８倍であり、前記ねじれ
位相差板の複屈折量を示すΔｎｄ値Ｒｃは前記液晶素子
のΔｎｄ値Ｒｓより０．１〜０．１５μｍ小さいことを
特徴とする。Further, in the liquid crystal display device of the present invention, a twist angle is formed between the first substrate having the semi-transmissive reflective layer and the first electrode, the second substrate having the second electrode, and the pair of substrates. Is 1
A liquid crystal element sandwiching a nematic liquid crystal having a twist orientation of 80 to 260 °, a twisted phase difference plate provided outside the second substrate, and a first polarizing plate provided outside the twisted phase difference plate. A first retardation plate provided outside the first substrate, a second retardation plate provided outside the first retardation plate, and a second retardation plate provided outside the second retardation plate. A polarizing plate and a backlight provided outside the second polarizing plate are provided, and the slow axis of the first retardation plate and the slow axis of the second retardation plate intersect at approximately 60 °. The retardation value of the first retardation plate is about 1/4 wavelength, the retardation value of the second retardation plate is about 1/2 wavelength, and the twist direction of the twisted retardation plate is the liquid crystal. The device has a reverse-twisted structure and the liquid crystal molecule has an upper liquid crystal molecule alignment direction and a twisted phase difference plate lower molecule alignment direction. Angle α is located ° 80-100, there the angle β is ° 60-75 formed between the first transmission axis and the molecular orientation direction over the twisted retardation film of the polarizing plate,
The twist angle Tc of the twisted phase difference plate is 0.7 to 0.8 times the twist angle Ts of the liquid crystal element, and the Δnd value Rc indicating the birefringence amount of the twisted phase difference plate is the Δnd value of the liquid crystal element. It is characterized by being smaller than Rs by 0.1 to 0.15 μm.

【００２１】また、本発明の液晶表示装置では、前記液
晶素子のΔｎｄ値Ｒｓが０．７５〜０．９μｍであるこ
とを特徴とする。The liquid crystal display device of the present invention is characterized in that the Δnd value Rs of the liquid crystal element is 0.75 to 0.9 μm.

【００２２】〔作用〕本発明の液晶表示装置は、単偏光
板方式の液晶表示装置の光学素子として、ねじれ位相差
板１枚を用いている。ねじれ位相差板のツイスト方向
は、液晶素子のツイスト方向と逆にすることによって、
液晶素子で発生する複屈折性をねじれ位相差板により減
算している。ねじれ位相差板のツイスト角を液晶表示装
置のツイスト角より小さくし、そして、ねじれ位相差板
の複屈折量を示すΔｎｄを液晶素子のΔｎｄより小さく
することで、液晶素子とねじれ位相差板で発生する実質
的な位相差値を１／４波長としている。[Operation] In the liquid crystal display device of the present invention, one twisted phase difference plate is used as the optical element of the single polarizing plate type liquid crystal display device. By making the twist direction of the twisted phase plate opposite to the twist direction of the liquid crystal element,
The birefringence generated in the liquid crystal element is subtracted by the twisted phase difference plate. By making the twist angle of the twisted phase difference plate smaller than the twist angle of the liquid crystal display device and making Δnd indicating the birefringence amount of the twisted phase difference plate smaller than Δnd of the liquid crystal element, the liquid crystal element and the twisted phase difference plate are The substantial phase difference value generated is ¼ wavelength.

【００２３】さらに、液晶素子とねじれ位相差板で発生
する位相差値Ｆを、すべての波長で１／４波長とするた
めに、液晶素子のツイスト角に対するねじれ位相差板の
ツイスト角を特定し、液晶素子のΔｎｄに対するねじれ
位相差板のΔｎｄを特定し、液晶素子に対するねじれ位
相差板の配置角を特定し、ねじれ位相差板に対する偏光
板の配置角度を特定し、液晶素子のΔｎｄ値の範囲を特
定する。Further, in order to set the phase difference value F generated in the liquid crystal element and the twisted phase difference plate to ¼ wavelength at all wavelengths, the twist angle of the twisted phase difference plate with respect to the twist angle of the liquid crystal element is specified. , Δnd of the twisted phase difference plate with respect to Δnd of the liquid crystal element, the arrangement angle of the twisted phase difference plate with respect to the liquid crystal element, the arrangement angle of the polarizing plate with respect to the twisted phase difference plate, and the Δnd value of the liquid crystal element Specify the range.

【００２４】その結果、液晶素子とねじれ位相差板で発
生する位相差値Ｆを波長λで除したＦ／λ値を、ほぼす
べての波長において１／４の一定にすることが可能とな
る。As a result, the F / λ value obtained by dividing the phase difference value F generated by the liquid crystal element and the twisted phase difference plate by the wavelength λ can be made constant at ¼ at almost all wavelengths.

【００２５】反射板の上に、このようにすべての波長で
Ｆ／λ値が１／４で一定である、いわゆる広帯域１／４
波長板を配置し、その上に偏光板を設ける。偏光板の透
過軸が広帯域１／４波長板の遅相軸に対して４５゜にな
るように配置すると、入射した直線偏光はすべての波長
で円偏光となり、反射板で反射し、再度、広帯域１／４
波長板を透過すると、すべての波長が偏光方向の９０゜
回転した直線偏光となり、偏光板に吸収され、完全な黒
を得ることができる。On the reflector, the so-called wideband 1/4 in which the F / λ value is constant at 1/4 at all wavelengths is thus set.
A wave plate is arranged and a polarizing plate is provided thereon. If the transmission axis of the polarizing plate is arranged at 45 ° with respect to the slow axis of the broadband quarter-wave plate, the incident linearly polarized light becomes circularly polarized light at all wavelengths, is reflected by the reflection plate, and is again broadband. 1/4
When transmitted through the wave plate, all the wavelengths become linearly polarized light rotated by 90 ° in the polarization direction and are absorbed by the polarizing plate, so that perfect black can be obtained.

【００２６】つまり、反射表示においては、ねじれ位相
差板のツイスト角、Δｎｄ値、配置角、偏光板の配置角
を最適化し、液晶素子のΔｎｄ値の範囲を特定すること
によって、可視光領域のすべての波長での反射率を低く
でき、良好な黒を得ることができ、高コントラストの表
示が可能である。That is, in the reflective display, the twist angle, the Δnd value, the arrangement angle, and the arrangement angle of the polarizing plate of the twisted phase difference plate are optimized, and the range of the Δnd value of the liquid crystal element is specified to determine the visible light range. The reflectance at all wavelengths can be lowered, good black can be obtained, and high-contrast display is possible.

【００２７】一方、透過表示においては、バックライト
から出た光は、液晶素子の裏面に設けた偏光板と位相差
値が１／４波長の位相差板とを透過し、さらに半透過反
射層を透過して液晶素子に入射する。液晶素子の複屈折
性と、ねじれ位相差板で発生する位相差は、１／４波長
相当になっているので、液晶素子の複屈折性とを減算す
るように液晶素子の裏面に設けた位相差板を配置する
と、バックライトから出た光は、そのままの状態で視認
側の偏光板に到達する。したがって、バックライト側の
偏光板の透過軸と視認側の偏光板の透過軸とが直交に配
置してあると、良好な黒表示が得られる。On the other hand, in the transmissive display, the light emitted from the backlight is transmitted through the polarizing plate provided on the back surface of the liquid crystal element and the retardation plate having a retardation value of ¼ wavelength, and further the semi-transmissive reflection layer. And then enters the liquid crystal element. Since the birefringence of the liquid crystal element and the phase difference generated by the twisted phase difference plate are equivalent to ¼ wavelength, the birefringence of the liquid crystal element should be provided on the back surface of the liquid crystal element so as to be subtracted. When the retardation plate is arranged, the light emitted from the backlight reaches the polarizing plate on the viewing side as it is. Therefore, when the transmission axis of the polarizing plate on the backlight side and the transmission axis of the polarizing plate on the viewing side are arranged orthogonal to each other, excellent black display can be obtained.

【００２８】そして、液晶素子に電圧を印加した状態で
は、液晶素子の複屈折性が変化し、反射表示および透過
表示ともに良好な白表示を得ることが可能となり、反射
表示と透過表示の両方で高コントラストが得られる単偏
光板方式の液晶表示装置を提供することができる。When a voltage is applied to the liquid crystal element, the birefringence of the liquid crystal element changes, and good white display can be obtained in both reflective display and transmissive display. In both reflective display and transmissive display. It is possible to provide a single-polarizer type liquid crystal display device that can obtain high contrast.

【００２９】[0029]

【発明の実施の形態】以下図面を用いて本発明を実施す
るための最良な形態における液晶表示装置の構成を説明
する。BEST MODE FOR CARRYING OUT THE INVENTION The configuration of a liquid crystal display device in the best mode for carrying out the present invention will be described below with reference to the drawings.

【００３０】〔第１の実施の形態における液晶表示装置
の構成：図１、図２、図３〕まずはじめに、本発明の第
１の実施形態における液晶表示装置の構成を、図面を用
いて説明する。図１は本発明の第１の実施形態における
液晶表示装置の構成要素を説明するための断面図で、図
２は画素部を拡大した平面図で、図３は構成要素の配置
関係示す平面図である。以下、図１〜図３を用いて、本
発明の液晶表示装置の構成を説明する。[Structure of Liquid Crystal Display Device in First Embodiment: FIGS. 1, 2, and 3] First, the structure of the liquid crystal display device in the first embodiment of the present invention will be described with reference to the drawings. To do. FIG. 1 is a cross-sectional view for explaining constituent elements of a liquid crystal display device according to a first embodiment of the present invention, FIG. 2 is an enlarged plan view of a pixel portion, and FIG. 3 is a plan view showing an arrangement relationship of the constituent elements. Is. The configuration of the liquid crystal display device of the present invention will be described below with reference to FIGS.

【００３１】本発明の液晶表示装置は、図１に示すよう
に、液晶素子２０と、液晶素子２０の上側に設けたねじ
れ位相差板１２と、第１の偏光板１１により構成する。As shown in FIG. 1, the liquid crystal display device of the present invention comprises a liquid crystal element 20, a twisted phase difference plate 12 provided above the liquid crystal element 20, and a first polarizing plate 11.

【００３２】第１の偏光板１１とねじれ位相差板１２
は、アクリル系粘着剤で一体化してあり、液晶素子２０
とも、アクリル系粘着剤で貼り付けてある。First polarizing plate 11 and twisted phase difference plate 12
Is integrated with an acrylic adhesive and is used as a liquid crystal element 20.
Both are attached with an acrylic adhesive.

【００３３】液晶素子２０は、アルミニウムからなる厚
さ０．１μｍの反射層７とアクリル系材料からなる厚さ
２μｍの保護膜８と透明電極材料である酸化インジウム
スズ（以下、ＩＴＯと記載する）からなる第１の電極３
が形成されている厚さ０．５ｍｍのガラス板からなる第
１の基板１と、ＩＴＯからなる第２の電極４が形成され
ている厚さ０．５ｍｍのガラス板からなる第２の基板２
と、第１の基板１と第２の基板２を張り合わせるシール
材５と、第１の基板１と第２の基板２に狭持されている
左回り２４０°ツイスト配向しているネマチック液晶６
とから形成している。The liquid crystal element 20 includes a reflective layer 7 made of aluminum and having a thickness of 0.1 μm, a protective film 8 made of acrylic material and having a thickness of 2 μm, and indium tin oxide (hereinafter referred to as ITO) which is a transparent electrode material. The first electrode 3 consisting of
A first substrate 1 made of a glass plate having a thickness of 0.5 mm and having a thickness of 0.5 mm, and a second substrate 2 made of a glass plate having a thickness of 0.5 mm and having a second electrode 4 made of ITO formed therein.
And a sealing material 5 for adhering the first substrate 1 and the second substrate 2 together with a nematic liquid crystal 6 which is sandwiched between the first substrate 1 and the second substrate 2 and is counterclockwise twisted by 240 °.
It is formed from and.

【００３４】ＩＴＯからなる第１の電極３と第２の電極
４の透過率は、明るさの点で重要である。ＩＴＯのシー
ト抵抗値が低いほど、膜厚が厚くなり、透過率が低くな
る。本発明の実施の形態では、第２の電極４に、データ
信号を印加したので、クロストークの影響が少なく、シ
ート抵抗値が１００オームで、厚さ０．０５μｍのＩＴ
Ｏを用い、平均透過率は、約９２％である。The transmittance of the first electrode 3 and the second electrode 4 made of ITO is important in terms of brightness. The lower the sheet resistance value of ITO, the thicker the film thickness and the lower the transmittance. In the embodiment of the present invention, since the data signal is applied to the second electrode 4, the influence of crosstalk is small, the sheet resistance value is 100 ohms, and the thickness of the IT is 0.05 μm.
O is used and the average transmittance is about 92%.

【００３５】第１の電極３には、走査信号を印加してい
るので、クロストークを低下するためにシート抵抗値１
０オームで厚さ０．３μｍのＩＴＯを用い、平均透過率
は、約８９％と低いが、本発明の実施の形態のように、
少なくとも１方の基板に、透過率が９０％以上の透明電
極を用いることで、明るさを改善できる。図２に示した
ように、第１の電極３と第２の電極４との交差した部分
が画素となる。Since a scanning signal is applied to the first electrode 3, a sheet resistance value of 1 is used to reduce crosstalk.
Although ITO having a thickness of 0 .mu.m and a thickness of 0.3 .mu.m is used and the average transmittance is as low as about 89%, as in the embodiment of the present invention,
The brightness can be improved by using a transparent electrode having a transmittance of 90% or more on at least one of the substrates. As shown in FIG. 2, the intersection of the first electrode 3 and the second electrode 4 becomes a pixel.

【００３６】反射層７は、アルミニウム薄膜をスパッタ
法で形成し、さらに表面を保護するために厚さ０．０３
μｍの酸化シリコン（ＳｉＯ2 ）をスパッタ法で表面に
形成し、図２に示したように画素周辺に長方形の形状に
形成した。さらに、反射層７の表面に凹凸をつけ、散乱
性を与えると、視野角特性が改善し、より好ましい。The reflection layer 7 is formed of an aluminum thin film by a sputtering method, and has a thickness of 0.03 to protect the surface.
A silicon oxide (SiO 2 ) layer having a thickness of μm was formed on the surface by a sputtering method, and formed in a rectangular shape around the pixel as shown in FIG. Further, it is more preferable to make the surface of the reflective layer 7 uneven so as to provide scattering properties, since the viewing angle characteristics are improved.

【００３７】ねじれ位相差板１２は、ねじれ構造を持つ
液晶性高分子ポリマーを、トリアセチルセルロース（Ｔ
ＡＣ）フィルムやポリエチレンテレフタレート（ＰＥ
Ｔ）フィルムに配向処理してから塗布し、１５０゜Ｃ程
度の高温で、液晶状態にして、ツイスト角を調整後、室
温まで急冷して、そのねじれ状態を固定化したフィルム
である。The twisted retardation plate 12 is made of triacetyl cellulose (T
AC) film and polyethylene terephthalate (PE
T) A film in which a twisted state is fixed by applying an orientation treatment to a film, applying it to a liquid crystal state at a high temperature of about 150 ° C., adjusting the twist angle, and then rapidly cooling it to room temperature.

【００３８】あるいは、別に用意した配向処理を施した
フィルムに、ねじれ状態を固定後、ＴＡＣフィルムに液
晶性高分子ポリマーを転写して形成したフィルムであ
り、ツイスト角Ｔｃ＝１８０゜の右回りのねじれ位相差
板１２を用いる。Alternatively, it is a film formed by fixing a twisted state to a separately prepared film which has been subjected to an orientation treatment, and then transferring a liquid crystalline polymer to a TAC film, which has a twist angle Tc of 180 ° in a clockwise direction. The twisted phase plate 12 is used.

【００３９】第１の偏光板１１は、なるべく明るく、か
つ、偏光度が高いことが好ましく、本発明の実施の形態
では、透過率４５％で偏光度９９．９％の材料を使用し
た。第１の偏光板１１の表面に、屈折率の異なる無機薄
膜を、真空蒸着法やスパッタ法で数層コートした反射率
が０．５％程度の無反射層を設けることで、第１の偏光
板１１の表面反射が低下することで透過率が改善し、明
るくなり、また、黒レベルが低下することでコントラス
トも改善し、さらに好ましい。The first polarizing plate 11 is preferably as bright as possible and has a high degree of polarization. In the embodiment of the present invention, a material having a transmittance of 45% and a degree of polarization of 99.9% was used. By forming an inorganic thin film having a different refractive index on the surface of the first polarizing plate 11 by vacuum vapor deposition or sputtering to form a non-reflective layer having a reflectance of about 0.5%, the first polarized light can be obtained. The reduction of the surface reflection of the plate 11 improves the transmittance and makes it brighter, and the reduction of the black level improves the contrast, which is more preferable.

【００４０】しかし、無機薄膜は高価であるので、最近
は、１層〜２層の有機材料をコートした塗布タイプの無
反射膜が開発されており、反射率は１％前後と多少高い
が、低価格であり、これらの無反射膜でも、無反射層と
して使用可能である。However, since the inorganic thin film is expensive, a coating type non-reflective film coated with one or two layers of organic material has been developed recently, and although the reflectance is as high as about 1%, It is inexpensive and can be used as an antireflection layer even with these antireflection films.

【００４１】つぎに、それぞれの構成部材の配置関係を
図３を用いて説明する。第１の電極３と第２の電極４の
表面には配向膜（図示せず）が形成され、図３（ａ）に
示すように、第１の基板１は、水平軸Ｈに対して、右上
がり３０゜方向にラビング処理することで、下液晶分子
配向方向６ａは＋３０゜となり、第２の基板２は右下が
り３０゜方向にラビング処理することで上液晶分子配向
方向６ｂは−３０゜となる。粘度２０ｃｐのネマチック
液晶には、カイラル材と呼ぶ旋回性物質を添加し、ねじ
れピッチＰを１１μｍに調整し、左回りでツイスト角Ｔ
ｓ＝２４０゜ツイストのＳＴＮモードの液晶素子２０を
形成する。Next, the positional relationship between the respective constituent members will be described with reference to FIG. An alignment film (not shown) is formed on the surfaces of the first electrode 3 and the second electrode 4, and as shown in FIG. 3A, the first substrate 1 is When the rubbing treatment is performed in the upward 30 ° direction, the lower liquid crystal molecule orientation direction 6a becomes + 30 °, and the second substrate 2 is rubbed in the downward right 30 ° direction, and the upper liquid crystal molecule orientation direction 6b is −30 °. Becomes A nematic liquid crystal having a viscosity of 20 cp is added with a swirling substance called a chiral material, the twist pitch P is adjusted to 11 μm, and the twist angle T is counterclockwise.
The STN mode liquid crystal element 20 with s = 240 ° twist is formed.

【００４２】使用するネマチック液晶６の複屈折の差Δ
ｎは０．１５で、第１の基板１と第２の基板２のすきま
であるセルギャップｄは５．４μｍとする。したがって
ネマチック液晶６の複屈折の差Δｎとセルギャップｄと
の積で表す液晶素子２０の複屈折性を示すΔｎｄ値Ｒｓ
＝０．８１μｍとなる。Difference in birefringence of the nematic liquid crystal 6 used Δ
n is 0.15, and the cell gap d between the first substrate 1 and the second substrate 2 is 5.4 μm. Therefore, the Δnd value Rs indicating the birefringence of the liquid crystal element 20 represented by the product of the difference Δn in the birefringence of the nematic liquid crystal 6 and the cell gap d.
= 0.81 μm.

【００４３】第１の偏光板の透過軸１１ａは水平軸Ｈを
基準にして、−５５゜に配置する。ねじれ位相差板１２
は、複屈折性を示すΔｎｄ値Ｒｃ＝０．６８μｍのもの
を用いる。ねじれ位相差板１２の下分子配向方向１２ａ
は、図３（ｂ）に示すように、水平軸Ｈを基準にして＋
５５゜に配置し、上分子配向方向１２ｂは、＋５５゜に
配置し、右回りでツイスト角Ｔｃ＝１８０゜となり、ツ
イスト角の比Ｔｃ／Ｔｓ＝０．７５であり、複屈折の差
ΔＲ＝Ｒｓ−Ｒｃ＝０．１３μｍとなっている。The transmission axis 11a of the first polarizing plate is arranged at -55 ° with reference to the horizontal axis H. Twisted phase plate 12
Is a birefringent Δnd value Rc = 0.68 μm. Lower molecule orientation direction 12a of twisted phase plate 12
Is, based on the horizontal axis H, as shown in FIG.
The upper molecular orientation direction 12b is + 55 °, the twist angle Tc is 180 ° clockwise, the twist angle ratio Tc / Ts = 0.75, and the birefringence difference ΔR = Rs−Rc = 0.13 μm.

【００４４】〔第１の実施の形態の効果：図１１、図１
２、図１３、図１４、図１５〕つぎに、本発明の実施の
形態の液晶表示装置の効果について図面を用いて説明す
る[Effects of First Embodiment: FIGS. 11 and 1]
2, FIG. 13, FIG. 14, and FIG. 15] Next, effects of the liquid crystal display device according to the embodiment of the present invention will be described with reference to the drawings.

【００４５】図１５は、本発明の実施の形態の液晶表示
装置において、構成要素の配置関係示す平面図である。
６ａは液晶素子２０の下液晶分子配向方向を示し、６ｂ
は液晶素子２０の上液晶分子配向方向を示し、６ｂから
６ａへ向かう角度が液晶素子２０のツイスト角Ｔｓであ
る。１２ａはねじれ位相差板１２の下分子配向方向を示
し、１２ｂはねじれ位相差板１２の上分子配向方向を示
し、１２ｂから１２ａへ向かう角度がねじれ位相差板１
２のツイスト角Ｔｃである。液晶素子２０の上液晶分子
配向６ｂにたいして、ねじれ位相差板１２の下分子配向
方向１２ａが反時計回り方向になす角度が、ねじれ位相
差板１２の配置角αを示し、ねじれ位相差板１２の上分
子配向方向１２ｂに対し第１の偏光板１１の透過軸１１
ａが反時計回り方向になす角度が、第１の偏光板１１の
配置角βを示す。FIG. 15 is a plan view showing an arrangement relationship of constituent elements in the liquid crystal display device according to the embodiment of the present invention.
6a indicates a lower liquid crystal molecule alignment direction of the liquid crystal element 20, and 6b
Represents the alignment direction of the upper liquid crystal molecules of the liquid crystal element 20, and the angle from 6b to 6a is the twist angle Ts of the liquid crystal element 20. Reference numeral 12a indicates the lower molecular orientation direction of the twisted phase plate 12, 12b indicates the upper molecular orientation direction of the twisted phase plate 12, and the angle from 12b to 12a is the twisted phase plate 1
It is a twist angle Tc of 2. An angle formed by the lower molecular orientation direction 12a of the twisted phase difference plate 12 in the counterclockwise direction with respect to the upper liquid crystal molecule orientation 6b of the liquid crystal element 20 indicates the arrangement angle α of the twisted phase difference plate 12, and The transmission axis 11 of the first polarizing plate 11 with respect to the upper molecule orientation direction 12b
The angle that a makes in the counterclockwise direction indicates the arrangement angle β of the first polarizing plate 11.

【００４６】図１１は、本発明の第１の実施の形態の液
晶表示装置において、ねじれ位相差板のツイスト角Ｔｃ
を変化させた場合のコントラストの変化を図示したグラ
フであり、曲線３１は液晶素子２０のΔｎｄ値Ｒｓ＝
０．８１μｍ、液晶素子２０のツイスト角Ｔｓ＝２４０
゜、ねじれ位相差板１２のΔｎｄ値Ｒｃ＝０．６８μｍ
の場合である。曲線３２は液晶素子２０のΔｎｄ値Ｒｓ
＝０．８７μｍ、液晶素子２０のツイスト角Ｔｓ＝２２
０゜、ねじれ位相差板１２のΔｎｄ値Ｒｃ＝０．７５μ
ｍの場合である。FIG. 11 shows the twist angle Tc of the twisted phase difference plate in the liquid crystal display device according to the first embodiment of the present invention.
9 is a graph showing a change in contrast when V is changed, and a curve 31 indicates a Δnd value Rs = of the liquid crystal element 20.
0.81 μm, twist angle Ts of liquid crystal element 20 = 240
゜, Δnd value of twisted phase plate 12 Rc = 0.68 μm
Is the case. The curve 32 indicates the Δnd value Rs of the liquid crystal element 20.
= 0.87 μm, twist angle Ts of liquid crystal element 20 = 22
0 °, Δnd value of twisted phase plate 12 Rc = 0.75μ
This is the case of m.

【００４７】図１１の横軸は、ねじれ位相差板のツイス
ト角Ｔｃを、液晶素子のツイスト角Ｔｓで除した値で、
縦軸は液晶表示装置を２００分割で駆動した際に、反射
状態で測定したコントラストである。The horizontal axis of FIG. 11 is a value obtained by dividing the twist angle Tc of the twisted phase plate by the twist angle Ts of the liquid crystal element.
The vertical axis represents the contrast measured in the reflective state when the liquid crystal display device was driven in 200 divisions.

【００４８】曲線３１に示すように、Ｔｓ＝２４０°の
場合、Ｔｃ／Ｔｓが０．７〜０．８の範囲で高いコント
ラストが得られ、とくに、Ｔｃ／Ｔｓ＝０．７５（Ｔｃ
＝１８０°）近傍で最も高くなった。As shown by the curve 31, when Ts = 240 °, a high contrast is obtained in the range of Tc / Ts of 0.7 to 0.8, and in particular, Tc / Ts = 0.75 (Tc
= 180 °).

【００４９】つぎに、図１２は、本発明の実施の形態の
液晶表示装置において、ねじれ位相差板のΔｎｄ値Ｒｃ
を変化させた場合のコントラストの変化を図示したグラ
フであり、曲線３３は液晶素子２０のΔｎｄ値Ｒｓ＝
０．８１μｍ、液晶素子２０のツイスト角Ｔｓ＝２４０
゜、ねじれ位相差板１２のツイスト角Ｔｃ＝１８０゜の
場合である。曲線３４は液晶素子２０のΔｎｄ値Ｒｓ＝
０．８７μｍ、液晶素子２０のツイスト角Ｔｓ＝２２０
゜、ねじれ位相差板１２のツイスト角Ｔｃ＝１６０゜の
場合である。Next, FIG. 12 shows the Δnd value Rc of the twisted phase difference plate in the liquid crystal display device according to the embodiment of the present invention.
9 is a graph illustrating a change in contrast when V is changed, and a curve 33 indicates a Δnd value Rs = of the liquid crystal element 20.
0.81 μm, twist angle Ts of liquid crystal element 20 = 240
And the twist angle Tc of the twisted phase plate 12 is 180 °. The curve 34 indicates the Δnd value Rs = of the liquid crystal element 20.
0.87 μm, twist angle Ts of liquid crystal element 20 = 220
And the twist angle Tc of the twisted phase plate 12 is 160 °.

【００５０】図１２の横軸は、液晶素子２０のΔｎｄ値
Ｒｓからねじれ位相差板１２のΔｎｄ値Ｒｃを減じた値
で、縦軸は液晶表示装置を２００分割で駆動した際に、
反射状態で測定したコントラストである。The horizontal axis of FIG. 12 is the value obtained by subtracting the Δnd value Rc of the twisted phase difference plate 12 from the Δnd value Rs of the liquid crystal element 20, and the vertical axis is when the liquid crystal display device is driven in 200 divisions.
It is the contrast measured in the reflective state.

【００５１】曲線３３に示すように、Ｔｓ＝２４０°の
場合、Ｒｓ−Ｒｃが０．１〜０．１５μｍの範囲で高い
コントラストが得られ、とくにＲｓ−Ｒｃが０．１３μ
ｍ（Ｒｃ＝０．６８μｍ）近傍で最も高くなった。As shown by the curve 33, when Ts = 240 °, a high contrast is obtained in the range of Rs-Rc of 0.1 to 0.15 μm, and particularly Rs-Rc of 0.13 μm.
It became the highest near m (Rc = 0.68 μm).

【００５２】つぎに図１３は、本発明の実施の形態の液
晶表示装置において、ねじれ位相差板１２の配置角を変
化した場合のコントラストの変化を図示したグラフであ
り、曲線３５は液晶素子２０のΔｎｄ値Ｒｓ＝０．８１
μｍ、液晶素子２０のツイスト角Ｔｓ＝２４０゜、ねじ
れ位相差板１２のツイスト角Ｔｃ＝１８０゜の場合であ
る。曲線３６は液晶素子２０のΔｎｄ値Ｒｓ＝０．８７
μｍ、液晶素子２０のツイスト角Ｔｓ＝２２０゜、ねじ
れ位相差板１２のツイスト角Ｔｃ＝１６０゜の場合であ
る。Next, FIG. 13 is a graph showing the change in contrast when the arrangement angle of the twisted phase difference plate 12 is changed in the liquid crystal display device according to the embodiment of the present invention, and the curve 35 is the liquid crystal element 20. Δnd value of Rs = 0.81
μm, the twist angle Ts of the liquid crystal element 20 = 240 °, and the twist angle Tc of the twisted phase difference plate 12 = 180 °. The curve 36 indicates the Δnd value Rs = 0.87 of the liquid crystal element 20.
μm, the twist angle Ts of the liquid crystal element 20 = 220 °, and the twist angle Tc of the twisted phase difference plate 12 = 160 °.

【００５３】図１３の横軸は、液晶素子２０の上液晶分
子配向６ｂに対し、ねじれ位相差板１２の下分子配向方
向１２ａが反時計回り方向になす角度で、図１５におい
て配置角αで定義している。縦軸は液晶表示装置を２０
０分割で駆動した際に、反射状態で測定したコントラス
トである。The horizontal axis of FIG. 13 is the angle formed by the lower molecular alignment direction 12a of the twisted phase difference plate 12 in the counterclockwise direction with respect to the upper liquid crystal molecular alignment 6b of the liquid crystal element 20, and is the arrangement angle α in FIG. It is defined. The vertical axis indicates the liquid crystal display device 20.
This is the contrast measured in the reflective state when driven with 0 division.

【００５４】曲線３５に示すように、Ｔｓ＝２４０°の
場合、配置角αが８０〜１００゜の範囲で高いコントラ
ストが得られ、とくに配置角αが８５゜近傍において最
も高くなった。As shown by the curve 35, when Ts = 240 °, a high contrast was obtained when the arrangement angle α was in the range of 80 to 100 °, and the highest was obtained especially when the arrangement angle α was in the vicinity of 85 °.

【００５５】つぎに、図１４は、本発明の実施の形態の
液晶表示装置において、第１の偏光板１１の配置角を変
化した場合のコントラストの変化を図示したグラフであ
り、曲線３７は液晶素子２０のΔｎｄ値Ｒｓ＝０．８１
μｍ、液晶素子２０のツイスト角Ｔｓ＝２４０゜、ねじ
れ位相差板１２のツイスト角Ｔｃ＝１８０゜の場合であ
る。曲線３８は液晶素子２０のΔｎｄ値Ｒｓ＝０．８７
μｍ、液晶素子２０のツイスト角Ｔｓ＝２２０゜、ねじ
れ位相差板１２のツイスト角Ｔｃ＝１６０゜の場合であ
る。Next, FIG. 14 is a graph showing the change in contrast when the arrangement angle of the first polarizing plate 11 is changed in the liquid crystal display device according to the embodiment of the present invention, and the curve 37 is the liquid crystal. Δnd value Rs = 0.81 of the element 20
μm, the twist angle Ts of the liquid crystal element 20 = 240 °, and the twist angle Tc of the twisted phase difference plate 12 = 180 °. The curve 38 indicates the Δnd value Rs = 0.87 of the liquid crystal element 20.
μm, the twist angle Ts of the liquid crystal element 20 = 220 °, and the twist angle Tc of the twisted phase difference plate 12 = 160 °.

【００５６】図１４の横軸は、ねじれ位相差板１２の上
分子配向方向１２ｂに対し、第１の偏光板１１の透過軸
１１ａが反時計回り方向になす角度で、図１５において
配置角βで定義している。縦軸は液晶表示装置を２００
分割で駆動した際に、反射状態で測定したコントラスト
である。The horizontal axis of FIG. 14 is the angle formed by the transmission axis 11a of the first polarizing plate 11 in the counterclockwise direction with respect to the upper molecular orientation direction 12b of the twisted phase plate 12, and the arrangement angle β in FIG. It is defined in. The vertical axis indicates the liquid crystal display device 200.
This is the contrast measured in the reflective state when driven by division.

【００５７】曲線３７は、配置角βが６０〜７５゜の範
囲で高いコントラストが得られ、とくにβが７０゜近傍
で最も高くなった。In the curve 37, a high contrast was obtained when the arrangement angle β was in the range of 60 to 75 °, and the highest was obtained particularly when β was around 70 °.

【００５８】さらに、液晶素子２０のΔｎｄ値Ｒｓを変
化させて、図１１〜図１４と同じように、コントラスト
変化を測定した。その結果、Ｒｓが７５０ｎｍ未満にな
るとコントラストが低下し、９００ｎｍを越えるとコン
トラストの低下は無いが、白表示が黄色く着色し、良好
な白黒表示が得られなかった。Further, by changing the Δnd value Rs of the liquid crystal element 20, the contrast change was measured in the same manner as in FIGS. 11 to 14. As a result, when Rs was less than 750 nm, the contrast was lowered, and when Rs was more than 900 nm, the contrast was not lowered, but white display was colored yellow, and good monochrome display was not obtained.

【００５９】このように、第１の偏光板１１と、ねじれ
位相差板１２と、反射層７を内在した液晶素子２０にお
いて、液晶素子２０に対するねじれ位相差板１２のツイ
スト角、Δｎｄ、配置角、ねじれ位相差板１２に対する
偏光板の配置角を最適化し、また液晶素子２０のΔｎｄ
値の範囲を限定することで、ノーマリー黒モードで、低
い反射率の黒を得ることで、高コントラストで、かつ、
明るい反射型の液晶表示装置を提供できる。As described above, in the liquid crystal element 20 including the first polarizing plate 11, the twisted phase difference plate 12, and the reflective layer 7, the twist angle, Δnd, and the arrangement angle of the twisted phase difference plate 12 with respect to the liquid crystal element 20. , The arrangement angle of the polarizing plate with respect to the twisted phase difference plate 12 is optimized, and Δnd of the liquid crystal element 20 is
By limiting the range of values, it is possible to obtain black with a low reflectance in a normally black mode, with high contrast, and
A bright reflective liquid crystal display device can be provided.

【００６０】〔第１の実施の形態の変形例〕本発明の実
施の形態では、ねじれ位相差板１２として、室温ではね
じれ状態が固定化している液晶性ポリマーフィルムを用
いたが、液晶分子の一部を鎖状のポリマー分子に結合し
ただけの、温度によりＲｃが変化する温度補償型ねじれ
位相差板を用いると、高温や低温での明るさやコントラ
ストが改善し、より良好な反射型液晶表示装置が得られ
る。[Modification of First Embodiment] In the embodiment of the present invention, as the twisted phase difference plate 12, a liquid crystal polymer film whose twisted state is fixed at room temperature is used. By using a temperature-compensated twisted retarder whose Rc changes only by a part of which is bonded to a chain polymer molecule, brightness and contrast at high and low temperatures are improved, and a better reflective liquid crystal display is obtained. The device is obtained.

【００６１】本発明の実施の形態では、反射層７を、第
１の電極３とは別に形成したが、第１の電極をアルミニ
ウムや銀等の金属薄膜で形なすることで、反射層７と兼
用した反射電極とすることで、構造を単純化することも
可能である。また、表示に影は発生するが、反射層７を
第１の基板１の外側に配置しても、同様な効果は得られ
る。In the embodiment of the present invention, the reflective layer 7 is formed separately from the first electrode 3. However, the reflective layer 7 is formed by forming the first electrode with a metal thin film such as aluminum or silver. It is also possible to simplify the structure by using the reflective electrode that also serves as. Further, although a shadow is generated on the display, the same effect can be obtained by arranging the reflective layer 7 outside the first substrate 1.

【００６２】〔第２の実施の形態〕つぎに、本発明の第
２の実施の形態の液晶表示装置の構成について説明す
る。第２の実施の形態の液晶表示装置は、液晶素子のツ
イスト角、Δｎｄ値、およびねじれ位相差板のツイスト
角、Δｎｄ値が第１の実施の形態と異なっている。[Second Embodiment] Next, the configuration of a liquid crystal display device according to a second embodiment of the present invention will be described. The liquid crystal display device of the second embodiment is different from that of the first embodiment in the twist angle, Δnd value of the liquid crystal element, and the twist angle, Δnd value of the twisted phase difference plate.

【００６３】〔液晶表示装置の構成：図１、図２、図
４〕本発明の第２の実施の形態における液晶表示装置の
構成を、図面を用いて説明する。構成要素の断面図（図
１）および画素部の拡大図（図２）は第１の実施の形態
と共通であるので、本発明の第２の実施形態における液
晶表示装置の構成要素については説明を省略し、配置関
係について説明する。[Configuration of Liquid Crystal Display Device: FIGS. 1, 2, and 4] The configuration of the liquid crystal display device according to the second embodiment of the present invention will be described with reference to the drawings. The cross-sectional view (FIG. 1) of the constituent elements and the enlarged view (FIG. 2) of the pixel portion are the same as those in the first embodiment, so the constituent elements of the liquid crystal display device in the second embodiment of the present invention will be described. Will be omitted and the arrangement relationship will be described.

【００６４】各構成部材の配置関係を図４を用いて説明
する。第１の電極３と第２の電極４の表面には配向膜
（図示せず）が形成され、図４（ａ）に示すように、第
１の基板１は、水平軸Ｈに対して、右上がり２０゜方向
にラビング処理することで、下液晶分子配向方向６ａは
＋２０゜となり、第２の基板２は右下がり２０゜方向に
ラビング処理することで上液晶分子配向方向６ｂは−２
０゜となる。粘度２０ｃｐのネマチック液晶には、カイ
ラル材と呼ぶ旋回性物質を添加し、ねじれピッチＰを１
１μｍに調整し、左回りでツイスト角Ｔｓ＝２２０゜ツ
イストのＳＴＮモードの液晶素子２０を形成する。The arrangement relationship of each component will be described with reference to FIG. An alignment film (not shown) is formed on the surfaces of the first electrode 3 and the second electrode 4, and as shown in FIG. 4A, the first substrate 1 is By rubbing in the upward 20 ° direction, the lower liquid crystal molecule alignment direction 6a becomes + 20 °, and by rubbing in the downward right 20 ° direction, the upper liquid crystal molecule alignment direction 6b becomes −2.
It becomes 0 °. A twisting substance called a chiral material is added to a nematic liquid crystal having a viscosity of 20 cp, and a twist pitch P is set to 1
The thickness is adjusted to 1 μm, and the STN mode liquid crystal element 20 having a twist angle Ts = 220 ° twist is formed counterclockwise.

【００６５】使用するネマチック液晶６の複屈折の差Δ
ｎは０．１５で、第１の基板１と第２の基板２のすきま
であるセルギャップｄは５．８μｍとする。したがっ
て、ネマチック液晶６の複屈折の差Δｎとセルギャップ
ｄとの積で表す液晶素子２０の複屈折性を示すΔｎｄ値
Ｒｓ＝０．８７μｍとなる。Difference in birefringence of the nematic liquid crystal 6 used Δ
n is 0.15, and the cell gap d between the first substrate 1 and the second substrate 2 is 5.8 μm. Accordingly, the Δnd value Rs = 0.87 μm, which indicates the birefringence of the liquid crystal element 20 expressed by the product of the difference Δn in the birefringence of the nematic liquid crystal 6 and the cell gap d.

【００６６】第１の偏光板の透過軸１１ａは、水平軸Ｈ
を基準にして−７０゜に配置する。ねじれ位相差板１２
は、複屈折性を示すΔｎｄ値Ｒｃ＝０．７５μｍのもの
を用いる。ねじれ位相差板１２の下分子配向方向１２ａ
は、図４（ｂ）に示すように、水平軸Ｈを基準にして＋
６５゜に配置し、上分子配向方向１２ｂは、＋４５゜に
配置し、右回りでツイスト角Ｔｃ＝１６０゜となり、ツ
イスト角の比Ｔｃ／Ｔｓ＝０．７３であり、複屈折の差
ΔＲ＝Ｒｓ−Ｒｃ＝０．１２μｍとなっている。The transmission axis 11a of the first polarizing plate is the horizontal axis H.
Is set at -70 ° with reference to. Twisted phase plate 12
Is a birefringent Δnd value Rc = 0.75 μm. Lower molecule orientation direction 12a of twisted phase plate 12
Is, based on the horizontal axis H, as shown in FIG.
The upper molecular orientation direction 12b is arranged at + 45 °, the twist angle Tc is 160 ° clockwise, the twist angle ratio Tc / Ts = 0.73, and the birefringence difference ΔR = Rs−Rc = 0.12 μm.

【００６７】〔第２の実施の形態の効果：図１１、図１
２、図１３、図１４、図１５〕つぎに、本発明の実施の
形態の液晶表示装置の効果について、第１の実施の形態
で用いた図１１〜図１３を用いて説明する[Effects of Second Embodiment: FIGS. 11 and 1]
2, FIG. 13, FIG. 14, FIG. 15] Next, the effect of the liquid crystal display device according to the embodiment of the present invention will be described with reference to FIGS. 11 to 13 used in the first embodiment.

【００６８】図１１の曲線３２に示すように、ツイスト
角Ｔｓが２２０°である本発明の実施の形態の液晶表示
装置においても、ねじれ位相差板１２のツイスト角Ｔｃ
は、Ｔｃ／Ｔｓが０．７〜０．８の範囲で高いコントラ
ストが得られ、とくにＴｃ／Ｔｓ＝０．７３（Ｔｃ＝１
６０°）近傍で最も高くなった。As shown by the curve 32 in FIG. 11, also in the liquid crystal display device according to the embodiment of the present invention in which the twist angle Ts is 220 °, the twist angle Tc of the twisted phase difference plate 12 is shown.
Has a high contrast when Tc / Ts is in the range of 0.7 to 0.8, and in particular, Tc / Ts = 0.73 (Tc = 1
It became highest around 60 °).

【００６９】図１２の曲線３４に示すように、ツイスト
角Ｔｓが２２０°である本発明の実施の形態の液晶表示
装置においても、ねじれ位相差板１２のΔｎｄ値Ｒｃ
は、Ｒｓ−Ｒｃが０．１〜０．１５μｍの範囲で高いコ
ントラストが得られ、とくにＲｓ−Ｒｃが０．１２μｍ
（Ｒｃ＝０．７５μｍ）近傍で最も高くなった。As shown by the curve 34 in FIG. 12, even in the liquid crystal display device according to the embodiment of the present invention in which the twist angle Ts is 220 °, the Δnd value Rc of the twisted phase difference plate 12 is obtained.
Has a high contrast in the range of Rs-Rc of 0.1 to 0.15 μm, and particularly Rs-Rc of 0.12 μm.
It was the highest in the vicinity of (Rc = 0.75 μm).

【００７０】図１３の曲線３６に示すように、ツイスト
角Ｔｓが２２０°である本発明の第２の実施の形態の液
晶表示装置においても、ねじれ位相差板１２の配置角α
が８０〜１００゜の範囲で高いコントラストが得られ、
とくに配置角αが８５゜近傍で最も高くなった。As shown by the curve 36 in FIG. 13, also in the liquid crystal display device according to the second embodiment of the present invention in which the twist angle Ts is 220 °, the arrangement angle α of the twisted phase difference plate 12 is large.
Has a high contrast in the range of 80 to 100 °,
In particular, the arrangement angle α was highest near 85 °.

【００７１】図１４の曲線３８に示すように、ツイスト
角Ｔｓが２２０°である本発明の第２の実施の形態の液
晶表示装置においても、第１の偏光板１１の配置角βが
６０〜７５゜の範囲で高いコントラストが得られ、とく
に配置角βが６５゜近傍で最も高くなった。As shown by the curve 38 in FIG. 14, also in the liquid crystal display device according to the second embodiment of the present invention in which the twist angle Ts is 220 °, the arrangement angle β of the first polarizing plate 11 is 60 to 60 °. A high contrast was obtained in the range of 75 °, and the arrangement angle β was the highest especially in the vicinity of 65 °.

【００７２】さらに、液晶素子２０のΔｎｄ値Ｒｓを変
化させて、コントラスト変化を測定した。その結果、ツ
イスト角Ｔｓが２２０゜である本発明の第２の実施の形
態の液晶表示装置においても、Ｒｓが７５０ｎｍ未満に
なるとコントラストが低下し、９００ｎｍを越えると、
コントラストの低下は無いが、白表示が黄色く着色し、
良好な白黒表示が得られなかった。Further, the contrast change was measured by changing the Δnd value Rs of the liquid crystal element 20. As a result, even in the liquid crystal display device according to the second embodiment of the present invention in which the twist angle Ts is 220 °, the contrast is deteriorated when Rs is less than 750 nm, and the contrast is increased when Rs exceeds 900 nm.
There is no decrease in contrast, but the white display turns yellow,
Good black and white display could not be obtained.

【００７３】このように、２２０°ツイストの液晶表示
装置においても、第１の偏光板１１と、ねじれ位相差板
１２と、反射層７を内在した液晶素子２０において、液
晶素子２０に対するねじれ位相差板１２のツイスト角、
Δｎｄ、配置角、ねじれ位相差板１２に対する偏光板１
１の配置角を最適化し、また液晶素子２０のΔｎｄ値の
範囲を限定している。このことにより、ノーマリー黒モ
ードで、低い反射率の黒を得ることで、高コントラスト
で、かつ、明るい反射型の液晶表示装置を提供できる。As described above, also in the liquid crystal display device of the 220 ° twist, in the liquid crystal element 20 including the first polarizing plate 11, the twisted phase difference plate 12, and the reflection layer 7, the twisted phase difference with respect to the liquid crystal element 20 is obtained. Twist angle of plate 12,
Polarizing plate 1 for Δnd, arrangement angle, and twisted phase difference plate 12
The arrangement angle of 1 is optimized, and the range of the Δnd value of the liquid crystal element 20 is limited. This makes it possible to provide a bright reflective liquid crystal display device with high contrast by obtaining black with low reflectance in a normally black mode.

【００７４】〔第２の実施の形態の変形例〕第１の実施
の形態における液晶素子ではツイスト角が２４０°、第
２の実施の形態における液晶素子ではツイスト角が２２
０°の液晶素子を用いたが、ツイスト角が１８０〜２６
０°の液晶素子でも同様に最適化することにより、同様
な反射型液晶表示装置が得られ、ねじれ位相差板１２の
ツイスト角Ｔｃは、Ｔｃ／Ｔｓが０．７〜０．８の範囲
で、ねじれ位相差板１２のΔｎｄ値ＲｃはＲｓ−Ｒｃが
０．１〜０．１５μｍの範囲で、ねじれ位相差板１２の
配置角αが８０〜１００゜の範囲で、第１の偏光板１１
の配置角βが６０〜７５゜の範囲で高いコントラストが
得られる。[Modification of Second Embodiment] In the liquid crystal element according to the first embodiment, the twist angle is 240 °, and in the liquid crystal element according to the second embodiment, the twist angle is 22 °.
A liquid crystal element of 0 ° was used, but the twist angle was 180 to 26.
A similar reflection type liquid crystal display device can be obtained by similarly optimizing the liquid crystal element of 0 °, and the twist angle Tc of the twisted phase plate 12 is Tc / Ts in the range of 0.7 to 0.8. The Δnd value Rc of the twisted phase difference plate 12 is such that Rs-Rc is in the range of 0.1 to 0.15 μm, the arrangement angle α of the twisted phase difference plate 12 is in the range of 80 to 100 °, and the first polarizing plate 11
A high contrast can be obtained when the arrangement angle β is 60 to 75 °.

【００７５】〔第３の実施の形態〕つぎに、本発明の第
３の実施の形態の液晶表示装置の構成について説明す
る。第３の実施の形態の液晶表示装置は、第１の実施の
形態の液晶表示装置に、第１の位相差板と第２の偏光板
とバックライトを追加して、透過表示も可能な半透過反
射型の液晶表示装置としたものである。[Third Embodiment] Next, the configuration of a liquid crystal display device according to a third embodiment of the present invention will be described. The liquid crystal display device of the third embodiment is a liquid crystal display device of the first embodiment in which a transmissive display is possible by adding a first retardation plate, a second polarizing plate and a backlight. This is a transflective liquid crystal display device.

【００７６】〔液晶表示装置の構成：図５、図６、図
７〕本発明の第３の実施の形態における液晶表示装置の
構成を、図面を用いて説明する。図５は本発明の第３の
実施の形態における液晶表示装置の構成要素を説明する
ための断面図で、図６は画素部を拡大した平面図で、図
７は構成要素の配置関係示す平面図である。以下、図５
〜図７を用いて、本発明の半透過反射型の液晶表示装置
の構成を説明する。[Structure of Liquid Crystal Display Device: FIGS. 5, 6, and 7] The structure of the liquid crystal display device according to the third embodiment of the present invention will be described with reference to the drawings. FIG. 5 is a cross-sectional view illustrating components of a liquid crystal display device according to a third embodiment of the present invention, FIG. 6 is an enlarged plan view of a pixel portion, and FIG. 7 is a plan view showing a layout of components. It is a figure. Below, FIG.
The configuration of the transflective liquid crystal display device of the present invention will be described with reference to FIGS.

【００７７】本発明の液晶表示装置は、図５に示すよう
に、液晶素子２１と、液晶素子２１の上側に設けたねじ
れ位相差板１２と、第１の偏光板１１と、液晶素子２１
の下側に設けた第１の位相差板１７と、第２の偏光板１
６と、バックライト１５により構成する。As shown in FIG. 5, the liquid crystal display device of the present invention includes a liquid crystal element 21, a twisted phase difference plate 12 provided above the liquid crystal element 21, a first polarizing plate 11, and a liquid crystal element 21.
The first retardation plate 17 provided on the lower side and the second polarizing plate 1
6 and the backlight 15.

【００７８】第１の偏光板１１とねじれ位相差板１２
は、アクリル系粘着剤で一体化してあり、液晶素子２１
とも、アクリル系粘着剤で貼り付けてある。また、第２
の偏光板１６と第１の位相差板１７は、アクリル系粘着
剤で一体化してあり、液晶素子２１とも、アクリル系粘
着剤で貼り付けてある。First polarizing plate 11 and twisted phase difference plate 12
Are integrated with an acrylic adhesive, and the liquid crystal element 21
Both are attached with an acrylic adhesive. Also, the second
The polarizing plate 16 and the first retardation plate 17 are integrated with an acrylic adhesive, and the liquid crystal element 21 is also attached with an acrylic adhesive.

【００７９】液晶素子２１は、アルミニウムからなる厚
さ０．１μｍの半透過反射層９とアクリル系材料からな
る厚さ２μｍの保護膜８と透明電極材料であるＩＴＯか
らなる厚さ０．３μｍの第１の電極３が形成されている
厚さ０．５ｍｍのガラス板からなる第１の基板１と、Ｉ
ＴＯからなる厚さ０．０５μｍ第２の電極４が形成され
ている厚さ０．５ｍｍのガラス板からなる第２の基板２
と、第１の基板１と第２の基板２を張り合わせるシール
材５と、第１の基板１と第２の基板２に狭持されている
左回り２４０゜ツイスト配向しているネマチック液晶６
とから形成している。The liquid crystal element 21 has a transflective layer 9 made of aluminum and having a thickness of 0.1 μm, a protective film 8 made of acrylic material and having a thickness of 2 μm, and a transparent electrode material made of ITO and having a thickness of 0.3 μm. A first substrate 1 made of a glass plate having a thickness of 0.5 mm on which a first electrode 3 is formed;
Second substrate 2 made of a glass plate having a thickness of 0.5 mm and having a second electrode 4 made of TO and having a thickness of 0.05 μm
And a sealing material 5 for bonding the first substrate 1 and the second substrate 2 together, and a nematic liquid crystal 6 which is sandwiched between the first substrate 1 and the second substrate 2 and is counterclockwise twisted by 240 °.
It is formed from and.

【００８０】図６に示したように、第１の電極３と第２
の電極４の交差した部分が画素となり、画素周辺に長方
形の半透過反射層９を設ける。半透過反射層９には、画
素毎に開口部２５がフォトリソ工程で設けてある。開口
部の面積で透過率と反射率を調整することが可能であ
る。本発明の第３の実施の形態では、開口部の面積を画
素面積の３０％に設定したので、３０％程度の光を透過
し、残りの７０％の光を反射するようにした。As shown in FIG. 6, the first electrode 3 and the second electrode 3
A portion where the electrodes 4 intersect is a pixel, and a rectangular semi-transmissive reflective layer 9 is provided around the pixel. The semi-transmissive reflective layer 9 is provided with an opening 25 for each pixel by a photolithography process. The transmittance and reflectance can be adjusted by the area of the opening. In the third embodiment of the present invention, since the area of the opening is set to 30% of the pixel area, about 30% of light is transmitted and the remaining 70% of light is reflected.

【００８１】ねじれ位相差板１２と第１の偏光板１１と
は、第１の実施の形態で用いたものと同一である。The twisted phase plate 12 and the first polarizing plate 11 are the same as those used in the first embodiment.

【００８２】第１の位相差板１７としては、ポリカーボ
ネートを延伸した厚さ約７０μｍで波長が０．５５μｍ
の位相差値Ｆ１＝０．１４μｍで、１／４波長板となっ
ている。第２の偏光板１６は、偏光度が高いことが重要
で、透過率４４％で、偏光度９９．９９％の材料を使用
した。The first retardation plate 17 is formed by stretching polycarbonate and has a thickness of about 70 μm and a wavelength of 0.55 μm.
Has a phase difference value F1 = 0.14 μm and is a quarter wavelength plate. It is important that the second polarizing plate 16 has a high degree of polarization, and a material having a transmittance of 44% and a degree of polarization of 99.99% was used.

【００８３】バックライト１５は、導光板に蛍光灯やＬ
ＥＤを取り付けたものや、エレクトロルミネッセンス
（ＥＬ）板などを用いることが可能であるが、本発明の
第３の実施の形態では厚さが約１ｍｍで、発光色が白色
のＥＬ板を用いた。The backlight 15 includes a fluorescent lamp or an L-shaped light guide plate.
It is possible to use an ED-attached one, an electroluminescence (EL) plate, or the like, but in the third embodiment of the present invention, an EL plate having a thickness of about 1 mm and a white emission color is used. .

【００８４】つぎに、各構成部材の配置関係を図７を用
いて説明する。図７（ｂ）に示した液晶素子２１から上
側の配置関係は、第１の実施の形態と同一であるので、
省略する。Next, the positional relationship among the constituent members will be described with reference to FIG. Since the arrangement relationship above the liquid crystal element 21 shown in FIG. 7B is the same as that of the first embodiment,
Omit it.

【００８５】液晶素子２１の下側に配置した第１の位相
差板の遅相軸１７ａは、図７（ａ）に示すように、水平
軸Ｈに対して＋８０゜に配置し、第２の偏光板の透過軸
１６ａは水平軸Ｈに対して＋３５゜に配置し、第１の偏
光板１１の透過軸１１ａと直交する。The slow axis 17a of the first retardation plate disposed below the liquid crystal element 21 is disposed at + 80 ° with respect to the horizontal axis H, as shown in FIG. The transmission axis 16a of the polarizing plate is arranged at + 35 ° with respect to the horizontal axis H and is orthogonal to the transmission axis 11a of the first polarizing plate 11.

【００８６】〔第３の実施の形態の効果：図５、図６、
図７〕つぎに、本発明の実施の形態の液晶表示装置の効
果について図面を用いて説明する。反射表示について
は、第１の実施の形態の効果と同一であり、良好なコン
トラストの表示が可能である。[Effects of Third Embodiment: FIGS. 5 and 6]
7] Next, effects of the liquid crystal display device according to the embodiment of the present invention will be described with reference to the drawings. The reflective display is the same as the effect of the first embodiment, and it is possible to display a good contrast.

【００８７】バックライト１５を点灯した透過表示につ
いて説明する。バックライト１５から出た光は、第２の
偏光板１６により直線偏光となる。この直線偏光は第１
の位相差板１７の遅相軸１７ａに対して４５゜の角度に
入射するので、円偏光となる。半透過反射層９で、約７
割は反射されるが、残りの３割の光が透過する。The transmissive display with the backlight 15 turned on will be described. The light emitted from the backlight 15 is linearly polarized by the second polarizing plate 16. This linearly polarized light is the first
Since the light is incident on the slow axis 17a of the retardation plate 17 at an angle of 45 °, it becomes circularly polarized light. About 7 in the semi-transmissive reflective layer 9
Although 30% is reflected, the remaining 30% of light is transmitted.

【００８８】液晶素子２１に電圧を印加していない状態
では、ねじれ位相差板１２と液晶素子２１により、複屈
折性がほぼ全波長にわたり１／４波長相当となってい
る。そこで、本発明の実施の形態のように配置すると、
第１の位相差板１７で発生した位相差は、液晶素子２１
とねじれ位相差板１２とで発生する位相差で減算されて
０となり、第２の偏光板の透過軸１６ａと同一方向の直
線偏光となって出射する。In the state where no voltage is applied to the liquid crystal element 21, the birefringence is equivalent to ¼ wavelength over almost all wavelengths due to the twisted phase plate 12 and the liquid crystal element 21. Therefore, when arranged like the embodiment of the present invention,
The phase difference generated in the first retardation plate 17 is the liquid crystal element 21.
The phase difference generated by the twisted phase difference plate 12 is subtracted and becomes 0, and the light is emitted as linearly polarized light in the same direction as the transmission axis 16a of the second polarizing plate.

【００８９】したがって、第１の偏光板の透過軸１１ａ
と第２の偏光板の透過軸１６ａが直交しているので、入
射光は透過せず、黒表示となる。Therefore, the transmission axis 11a of the first polarizing plate
Since the transmission axes 16a of the second polarizing plate are orthogonal to each other, incident light is not transmitted and black display is performed.

【００９０】つぎに、第１の電極３と第２の電極４の間
に、電圧を印加すると、ネマチック液晶６が立ち上が
り、液晶素子２１の実質的なΔｎｄ値が減少する。その
ため、第２の偏光板１６から入射した直線偏光は、第１
の位相差板１７を通過することで円偏光となるが、ねじ
れ位相差板１２と液晶素子２１を透過することで、楕円
偏光や直線偏光になる。Next, when a voltage is applied between the first electrode 3 and the second electrode 4, the nematic liquid crystal 6 rises, and the substantial Δnd value of the liquid crystal element 21 decreases. Therefore, the linearly polarized light incident from the second polarizing plate 16 is
The circularly polarized light is obtained by passing through the retardation plate 17 of the above, but the elliptically polarized light or the linearly polarized light is obtained by passing through the twisted retardation plate 12 and the liquid crystal element 21.

【００９１】この電圧印加により液晶素子２１で発生す
る位相差を１／４波長とすると、第２の偏光板１６より
入射した直線偏光は、ねじれ位相差板１２を透過するこ
とで９０゜回転するため、第１の偏光板１１を透過し、
良好な白表示を得ることができる。When the phase difference generated in the liquid crystal element 21 by applying this voltage is set to ¼ wavelength, the linearly polarized light incident from the second polarizing plate 16 is rotated by 90 ° by passing through the twisted phase difference plate 12. Therefore, the light passes through the first polarizing plate 11,
A good white display can be obtained.

【００９２】このように、第１の偏光板１１とねじれ位
相差板１２と半透過反射層９とを内在した液晶素子２１
によって、外光を用いる反射表示においては良好な黒表
示と明るい白表示が得られ、液晶素子２１の下側に第１
の位相差板１７と第２の偏光板１６とバックライト１５
を備えることで、外光が少ない環境ではバックライト１
５を点灯している。このことによって、良好なコントラ
ストの表示が得られる単偏光板方式の半透過反射型の液
晶表示装置を提供できる。As described above, the liquid crystal element 21 including the first polarizing plate 11, the twisted phase difference plate 12, and the semi-transmissive reflective layer 9 therein.
As a result, a good black display and a bright white display are obtained in the reflective display using external light, and the first black film is displayed below the liquid crystal element 21.
Retardation plate 17, second polarizing plate 16 and backlight 15
By providing a backlight 1 in an environment with little outside light
5 is lit. As a result, it is possible to provide a semi-transmissive reflection type liquid crystal display device of a single polarization plate type which can obtain a display with good contrast.

【００９３】また、画素毎に開口部２５を設けた半透過
反射層９を採用している。このことにより、開口部２５
を大きくすると透過表示重視の液晶表示装置に、開口部
２５を小さくすることで、反射表示重視の液晶表示装置
にと、対応が可能である。Further, the semi-transmissive reflective layer 9 provided with the opening 25 for each pixel is adopted. As a result, the opening 25
It is possible to cope with a liquid crystal display device that emphasizes transmissive display and a liquid crystal display device that emphasizes reflective display by decreasing the opening 25.

【００９４】〔第３の実施の形態の変形例〕本発明の実
施の形態では、第１の位相差板１７で発生する位相差
を、液晶素子２１で発生する位相差が減算するように配
置したが、第１の位相差板１７と液晶素子２１で発生す
る位相差とを加算して１／２波長相当になるように配置
し、さらに第２の偏光板の透過軸１６ａを第１の偏光板
の透過軸１１ａと平行に配置することも可能である。[Modification of Third Embodiment] In the embodiment of the present invention, the phase difference generated in the first retardation plate 17 is arranged to be subtracted from the phase difference generated in the liquid crystal element 21. However, the first retardation plate 17 and the phase difference generated in the liquid crystal element 21 are added and arranged so as to correspond to a half wavelength, and the transmission axis 16a of the second polarizing plate is set to the first retardation plate. It is also possible to arrange it in parallel with the transmission axis 11a of the polarizing plate.

【００９５】〔第４の実施の形態〕つぎに、本発明の第
４の実施の形態の液晶表示装置の構成について説明す
る。第４の実施の形態の液晶表示装置は、液晶素子の下
側に２枚の位相差板を備えること、散乱層を備えるこ
と、半透過反射板が異なること、カラーフィルタを備え
ることでカラー表示が可能となっていることが、第３の
実施の形態の構成と異なっている。[Fourth Embodiment] Next, the configuration of a liquid crystal display device according to a fourth embodiment of the present invention will be described. The liquid crystal display device according to the fourth embodiment includes two retardation films below the liquid crystal element, a scattering layer, different semi-transmissive reflection plates, and a color filter for color display. This is different from the configuration of the third embodiment.

【００９６】〔液晶表示装置の構成：図８、図９、図１
０〕本発明の第４の実施の形態における半透過反射型の
液晶表示装置の構成を、図面を用いて説明する。図８は
本発明の第４の実施のの形態における液晶表示装置の構
成要素を説明するための断面図で、図９は画素部を拡大
した平面図で、図１０は構成要素の配置関係示す平面図
である。以下、図８〜図１０を用いて、本発明の液晶表
示装置の構成を説明する。[Structure of Liquid Crystal Display Device: FIG. 8, FIG. 9, FIG.
[0] The configuration of the transflective liquid crystal display device according to the fourth embodiment of the present invention will be described with reference to the drawings. FIG. 8 is a cross-sectional view for explaining the constituent elements of the liquid crystal display device according to the fourth embodiment of the present invention, FIG. 9 is an enlarged plan view of a pixel portion, and FIG. 10 shows an arrangement relationship of the constituent elements. It is a top view. Hereinafter, the configuration of the liquid crystal display device of the present invention will be described with reference to FIGS.

【００９７】本発明の液晶表示装置は、図８に示すよう
に、液晶素子２２と、液晶素子２２の上側に設けた散乱
層１４と、ねじれ位相差板１２と、第１の偏光板１１
と、液晶素子２２の下側に設けた第１の位相差板１７
と、第２の位相差板１８と、第２の偏光板１６と、バッ
クライト１５により構成する。As shown in FIG. 8, the liquid crystal display device of the present invention has a liquid crystal element 22, a scattering layer 14 provided on the upper side of the liquid crystal element 22, a twisted phase difference plate 12, and a first polarizing plate 11.
And the first retardation plate 17 provided below the liquid crystal element 22.
The second retardation plate 18, the second polarizing plate 16, and the backlight 15.

【００９８】第１の偏光板１１とねじれ位相差板１２
は、アクリル系粘着剤で一体化してあり、散乱層１４で
液晶素子２２と貼り付けてある。また、第１の位相差板
１７と第２の位相差板１８と第２の偏光板１６はアクリ
ル系粘着剤で一体化してあり、液晶素子２３とも、アク
リル系粘着剤で貼り付けてある。First polarizing plate 11 and twisted phase difference plate 12
Are integrated with an acrylic adhesive and are attached to the liquid crystal element 22 by the scattering layer 14. Further, the first retardation plate 17, the second retardation plate 18, and the second polarizing plate 16 are integrated with an acrylic adhesive, and the liquid crystal element 23 is also attached with an acrylic adhesive.

【００９９】液晶素子２２は、アルミニウムからなる厚
さ０．０２μｍの半透過反射層１３と、赤フィルタＲ、
緑フィルタＧ、青フィルタＢの３色からなる厚さ１μｍ
のカラーフィルタ１０とアクリル系材料からなる厚さ２
μｍの保護膜８と透明電極材料であるＩＴＯからなる厚
さ０．３μｍの第１の電極３が形成されている厚さ０．
５ｍｍのガラス板からなる第１の基板１と、ＩＴＯから
なる厚さ０．０５μｍの第２の電極４が形成されている
厚さ０．５ｍｍのガラス板からなる第２の基板２と、第
１の基板１と第２の基板２を張り合わせるシール材５
と、第１の基板１と第２の基板２に狭持されている左回
り２４０゜ツイスト配向しているネマチック液晶６とか
ら形成してある。The liquid crystal element 22 comprises a semi-transmissive reflective layer 13 made of aluminum and having a thickness of 0.02 μm, a red filter R,
1 μm thickness consisting of three colors, green filter G and blue filter B
Color filter 10 and thickness 2 made of acrylic material
The protective film 8 having a thickness of 0.3 .mu.m and the first electrode 3 having a thickness of 0.3 .mu.m made of ITO, which is a transparent electrode material, are formed.
A first substrate 1 made of a glass plate having a thickness of 5 mm, a second substrate 2 made of a glass plate having a thickness of 0.5 mm on which a second electrode 4 made of ITO and having a thickness of 0.05 μm is formed; Sealing material 5 for bonding the first substrate 1 and the second substrate 2 together
And a nematic liquid crystal 6 which is sandwiched between the first substrate 1 and the second substrate 2 and has a 240 ° twist counterclockwise alignment.

【０１００】半透過反射層１３は、アルミニウムの膜厚
を非常に薄くすることで、一部の光は透過し、残りの光
は反射する、いわゆるハーフミラーにしてある。本発明
の実施の形態では、アルムニウムの膜厚を、０．０２μ
ｍとしたことによって、１０〜２０％程度の光を透過
し、残りの８０〜９０％の光を反射するようにし、図９
に示したように画素周辺に長方形の形状で形成した。The semi-transmissive reflective layer 13 is a so-called half mirror in which a part of light is transmitted and the remaining light is reflected by making the film thickness of aluminum very thin. In the embodiment of the present invention, the film thickness of aluminum is 0.02 μm.
By setting m, about 10 to 20% of light is transmitted and the remaining 80 to 90% of light is reflected.
As shown in FIG. 5, the pixel was formed in a rectangular shape around the pixel.

【０１０１】散乱層１４は、半透過反射層１３で反射し
た光を散乱し、広視野角で明るい表示を得るために設け
てある。外部から入射する光はなるべく前方に散乱透過
し、後方散乱が少ないものが、高コントラストが得られ
て好ましい。この実施形態では、粘着剤に微粒子を混合
した厚さ３０μｍの散乱性粘着剤を散乱層１４として用
い、液晶素子２２とねじれ位相差板１２の粘着剤として
も兼用している。The scattering layer 14 is provided to scatter the light reflected by the semi-transmissive reflective layer 13 to obtain a bright display with a wide viewing angle. It is preferable that the light incident from the outside be scattered and transmitted as far forward as possible and have little backscattering, because high contrast can be obtained. In this embodiment, a scattering adhesive having a thickness of 30 μm in which fine particles are mixed with the adhesive is used as the scattering layer 14, and is also used as the adhesive for the liquid crystal element 22 and the twisted phase plate 12.

【０１０２】また、散乱層１４には、位相差値をほとん
ど持たず、偏光状態を変化させにくい材料を用いたの
で、第２の基板２から第１の偏光板１１の間、あるいは
第１の偏光板１１の表面の、どこに配置してもよいが、
表示ボケを減らすために、なるべく第２の基板２の近く
が好ましい。また、第２の基板２の厚さも、なるべく薄
い方が、表示ボケが少なくなり好ましく、本発明の実施
の形態では厚さ０．５ｍｍとした。さらにまた、第２の
基板を０．４ｍｍと薄くし、第１の基板を０．５ｍｍ
と、第２の基板を第１の基板より薄くすることも可能で
ある。Since the scattering layer 14 is made of a material having almost no retardation value and hardly changing the polarization state, it is used between the second substrate 2 and the first polarizing plate 11 or the first polarizing plate 11. Although it may be arranged anywhere on the surface of the polarizing plate 11,
In order to reduce display blur, it is preferable to be as close to the second substrate 2 as possible. In addition, it is preferable that the thickness of the second substrate 2 is as thin as possible because the display blur is reduced, and the thickness is 0.5 mm in the embodiment of the present invention. Furthermore, the second substrate is thinned to 0.4 mm, and the first substrate is 0.5 mm.
Then, the second substrate can be made thinner than the first substrate.

【０１０３】バックライト１５は、第３の実施の形態と
同じ白色ＥＬを用いることも可能ではあるが、本発明の
実施の形態では、彩度と明るさを向上するために、導光
板に３波長型蛍光管を取り付けたサイドライト方式を用
いた。Although it is possible to use the same white EL as the backlight 15 in the third embodiment, in the embodiment of the present invention, in order to improve the saturation and the brightness, the light guide plate 3 is used. A sidelight system with a wavelength type fluorescent tube attached was used.

【０１０４】カラーフィルタ１０は、赤フィルタＲと、
緑フィルタＧと、青フィルタＢの３色で構成され、図９
に示すように、本発明の実施の形態では、第２の電極４
と平行になる縦ストライプ形状とする。各カラーフィル
タの幅は、第２の電極４の幅より広く形成し、すきまが
生じないようにしてある。カラーフィルタ１０の間にす
きまが生じると、入射光が増加し、明るくはなるが、表
示色に白の光が混色し、色純度が低下するので、好まし
くない。The color filter 10 includes a red filter R,
It is composed of three colors, a green filter G and a blue filter B.
In the embodiment of the present invention, as shown in FIG.
Vertical stripes parallel to. The width of each color filter is formed wider than the width of the second electrode 4 so that no gap is generated. When a gap is generated between the color filters 10, the incident light increases and the image becomes brighter, but white light is mixed in the display color and the color purity decreases, which is not preferable.

【０１０５】カラーフィルタ１０は明るさを改善するた
めに、分光スペクトルにおける最大透過率がなるべく高
いことが好ましく、各色の最大透過率は８０％以上が良
く、９０％以上が最も好ましい。また、分光スペクトル
における最小透過率も２０％〜５０％と高くする必要が
ある。In order to improve the brightness of the color filter 10, it is preferable that the maximum transmittance in the spectral spectrum is as high as possible, and the maximum transmittance of each color is preferably 80% or more, most preferably 90% or more. Further, the minimum transmittance in the spectral spectrum needs to be as high as 20% to 50%.

【０１０６】カラーフィルタ１０としては、顔料分散
型、染色型、印刷型、転写型、電着型などが使えるが、
アクリル系やＰＶＡ系の感光性樹脂に顔料を分散させた
顔料分散型が耐熱温度が高く、色純度も良いので、最も
好ましい。As the color filter 10, pigment dispersion type, dyeing type, printing type, transfer type, electrodeposition type and the like can be used.
A pigment dispersion type in which a pigment is dispersed in an acrylic or PVA type photosensitive resin has a high heat resistance temperature and a good color purity, and is most preferable.

【０１０７】このような高透過率のカラーフィルタを得
るために、第１の基板１にアルミニウム薄膜の半透過反
射層１３を形成し、半透過反射層１３の表面に厚さ０．
０３μｍの酸化シリコン（ＳｉＯ2 ）膜をスパッタリン
グ法で形成後、感光性樹脂に顔料を１０〜１５％配合し
たカラーレジストを、スピンナーを用いて第１の基板１
に塗布し、露光工程と現像工程を行い、厚さが１μｍ程
度でも、透過率が高いカラーフィルタ１０を形成した。In order to obtain such a high-transmittance color filter, a semi-transmissive reflective layer 13 made of an aluminum thin film is formed on the first substrate 1, and the semi-transmissive reflective layer 13 has a thickness of 0.
After forming a silicon oxide (SiO 2 ) film having a thickness of 03 μm by a sputtering method, a color resist prepared by mixing a photosensitive resin with a pigment in an amount of 10 to 15% is used as a first substrate 1 using a spinner.
Then, an exposure process and a development process were performed to form a color filter 10 having a high transmittance even with a thickness of about 1 μm.

【０１０８】第１の偏光板１１と、ねじれ位相差板１２
と、第２の偏光板１６は、第３の実施の形態で用いたも
のと同一である。The first polarizing plate 11 and the twisted phase difference plate 12
The second polarizing plate 16 is the same as that used in the third embodiment.

【０１０９】第１の位相差板１７は、ＰＣを延伸した厚
さ約７０μｍの透明フィルムで、波長０．５５μｍの位
相差値Ｆ１＝０．１４μｍで、１／４波長相当である。
第２の位相差板１８もＰＣを延伸した厚さ約７０μｍの
透明フィルムで、波長０．５５μｍの位相差値Ｆ２＝
０．２８μｍで、１／２波長相当に設定する。The first retardation plate 17 is a transparent film of PC having a thickness of about 70 μm, and has a retardation value F1 = 0.14 μm at a wavelength of 0.55 μm, which corresponds to a quarter wavelength.
The second retardation plate 18 is also a transparent film having a thickness of about 70 μm obtained by stretching PC, and has a retardation value F2 = 0.52 μm.
It is 0.28 μm and is set to be equivalent to ½ wavelength.

【０１１０】つぎに、各構成部材の配置関係を図１０を
用いて説明する。図１０（ｂ）に示した液晶素子２２か
ら上側の配置関係は、第１の実施の形態と同一であるの
で、省略する。Next, the positional relationship among the constituent members will be described with reference to FIG. The arrangement relationship above the liquid crystal element 22 shown in FIG. 10B is the same as that in the first embodiment, and therefore will be omitted.

【０１１１】液晶素子２２下側に配置した第１の位相差
板の遅相軸１７ａは、図１０（ａ）に示したように、水
平軸Ｈに対して＋５０゜に配置し、第２の位相差板の遅
相軸１８ａは、水平軸Ｈに対して−７０゜に配置し、第
２の偏光板の透過軸１６ａは水平軸Ｈに対して＋３５゜
に配置し、第１の偏光板の透過軸１１ａと直交する。The slow axis 17a of the first retardation plate disposed below the liquid crystal element 22 is disposed at + 50 ° with respect to the horizontal axis H as shown in FIG. The slow axis 18a of the retardation plate is arranged at -70 ° with respect to the horizontal axis H, and the transmission axis 16a of the second polarizing plate is arranged at + 35 ° with respect to the horizontal axis H. Is orthogonal to the transmission axis 11a.

【０１１２】〔第４の実施の形態の効果：図８、図９、
図１０〕つぎに本発明の実施の形態の液晶表示装置の効
果について、図面を用いて説明する。カラーフィルタ１
０はまったく複屈折性を持たないので、反射表示につい
ては、第３の実施の形態と同じであり、ねじれ位相差板
１２を用いることで、良好なコントラストの表示が可能
である。[Effects of Fourth Embodiment: FIGS. 8 and 9]
FIG. 10] Next, effects of the liquid crystal display device according to the embodiment of the present invention will be described with reference to the drawings. Color filter 1
Since 0 has no birefringence at all, the reflective display is the same as that in the third embodiment, and the use of the twisted phase difference plate 12 enables display with good contrast.

【０１１３】そして、表示画素のオンとオフを組み合わ
せることで、カラー表示が可能となる。たとえば、赤フ
ィルタＲをオン（白）とし、緑フィルタＧと青フィルタ
Ｂをオフ（黒）とすることで、赤表示が可能となる。Then, color display is possible by combining ON and OFF of the display pixels. For example, when the red filter R is turned on (white) and the green filter G and the blue filter B are turned off (black), red display is possible.

【０１１４】本発明の実施の形態の半透過反射型の液晶
表示装置は、反射率が高く、かつ、コントラスト比が１
０以上と高い値が得られたので、バックライト１５が非
点灯の反射表示でも、彩度が高く、明るいカラー表示が
得られた。The transflective liquid crystal display device according to the embodiment of the present invention has a high reflectance and a contrast ratio of 1.
Since a high value of 0 or more was obtained, bright color display with high saturation was obtained even in the reflective display in which the backlight 15 was not lit.

【０１１５】つぎに、バックライト１５を点灯した透過
表示について説明する。位相差値Ｆ１が１／４波長相当
の０．１４μｍである第１の位相差板１７と、位相差値
Ｆ２が１／２波長相当の０．２８μｍである第２の位相
差板１８を、図１０（ａ）に示したように、交差角が６
０゜となるように重ねることにより、波長０．５５μｍ
での２枚合計の位相差値は０．１４μｍとなり、波長
０．４μｍ付近の短波長では０．１４μｍより小さく、
波長０．７μｍ付近の長波長においては０．１４μｍよ
り大きくなる。また２枚合計の実質的な遅相軸は第１の
位相差板の遅相軸１７ａと第２の位相差板１８ａの中間
となり、水平軸Ｈに対して、＋８０゜方向となる。Next, the transmissive display with the backlight 15 turned on will be described. A first retardation plate 17 having a phase difference value F1 of 0.14 μm corresponding to a quarter wavelength and a second retardation plate 18 having a phase difference value F2 of 0.28 μm corresponding to a half wavelength, As shown in FIG. 10A, the intersection angle is 6
Wavelength of 0.55 μm by stacking at 0 °
The total retardation value of the two sheets is 0.14 μm, which is smaller than 0.14 μm at short wavelengths around 0.4 μm,
It becomes larger than 0.14 μm at a long wavelength near the wavelength of 0.7 μm. Further, the substantial slow axis of the two sheets is intermediate between the slow axis 17a of the first retardation plate and the second retardation plate 18a, and is + 80 ° with respect to the horizontal axis H.

【０１１６】つまり、２枚の位相差板を用いることで、
短波長の位相差値が長波長の位相差値より小さい、いわ
ゆる広帯域１／４波長板を形なすることが可能となる。
つまり、位相差値Ｆを波長λで除したＦ／Ｒ値は、すべ
ての可視光領域にわたり、ほぼ１／４にすることが可能
となり、その結果、可視光領域すべての波長で円偏光が
得られる。That is, by using two retardation plates,
It is possible to form a so-called wideband quarter-wave plate in which the retardation value of the short wavelength is smaller than the retardation value of the long wavelength.
In other words, the F / R value obtained by dividing the phase difference value F by the wavelength λ can be made approximately 1/4 over all visible light regions, and as a result, circularly polarized light can be obtained at all wavelengths in the visible light region. To be

【０１１７】バックライト１５から出た光は、第２の偏
光板１６により直線偏光となる。この直線偏光は第１の
位相差板１７と第２の位相差板１８の２枚合なする実質
的な遅相軸に対して４５゜の角度に入射するので、円偏
光となる。半透過反射層１３で、約８割は反射される
が、残りの２割の光が透過する。The light emitted from the backlight 15 becomes linearly polarized light by the second polarizing plate 16. This linearly polarized light is incident on the first retardation plate 17 and the second retardation plate 18 at an angle of 45 ° with respect to a substantial slow axis formed by the two retardation plates 17, and is thus circularly polarized light. About 80% of the light is reflected by the semi-transmissive reflective layer 13, but the remaining 20% of the light is transmitted.

【０１１８】液晶素子２２に電圧を印加していない状態
では、ねじれ位相差板１２と液晶素子２２により、複屈
折性がほぼ全波長にわたり１／４波長となっている。本
発明の実施の形態のように配置すると、第１の位相差板
１７と第２の位相差板１８で発生した位相差は、液晶素
子２２とねじれ位相差板１２とで発生する位相差で減算
されてゼロとなり、第２の偏光板の透過軸１６ａと同一
方向の直線偏光となって出射する。When no voltage is applied to the liquid crystal element 22, the birefringence of the twisted phase difference plate 12 and the liquid crystal element 22 is ¼ wavelength over almost all wavelengths. When arranged as in the embodiment of the invention, the phase difference generated between the first retardation plate 17 and the second retardation plate 18 is the phase difference generated between the liquid crystal element 22 and the twisted retardation plate 12. The subtraction results in zero, and the light is emitted as linearly polarized light in the same direction as the transmission axis 16a of the second polarizing plate.

【０１１９】第１の偏光板の透過軸１１ａと第２の偏光
板の透過軸１６ａが直交しているので、入射光は透過せ
ず、黒表示となる。そして、第１の位相差板１７と第２
の位相差板１８を用いたことで、第３の実施の形態より
も、良好な黒表示が得られた。Since the transmission axis 11a of the first polarizing plate and the transmission axis 16a of the second polarizing plate are orthogonal to each other, incident light is not transmitted and black display is performed. Then, the first retardation plate 17 and the second retardation plate 17
By using the retardation plate 18 of No. 3, better black display was obtained than in the third embodiment.

【０１２０】つぎに、第１の電極３と第２の電極４の間
に、電圧を印加すると、ネマチック液晶６が立ち上が
り、液晶素子２２の実質的なΔｎｄ値が減少する。その
ため、第２の偏光板１６から入射した直線偏光は、第１
の位相差板１７と第２の位相差板１８を通過することで
円偏光となるが、ねじれ位相差板１２と液晶素子２２を
透過することで、楕円偏光や直線偏光になる。Next, when a voltage is applied between the first electrode 3 and the second electrode 4, the nematic liquid crystal 6 rises, and the substantial Δnd value of the liquid crystal element 22 decreases. Therefore, the linearly polarized light incident from the second polarizing plate 16 is
Circularly polarized light is obtained by passing through the retardation plate 17 and the second retardation plate 18, while passing through the twisted retardation plate 12 and the liquid crystal element 22, becomes elliptically polarized light or linearly polarized light.

【０１２１】この電圧印加により液晶素子２２で発生す
る位相差を１／４波長とすると、第２の偏光板１７より
入射した直線偏光は、ねじれ位相差板１２を透過するこ
とで９０゜回転するため、第１の偏光板１１を透過し、
良好な白表示を得ることができる。When the phase difference generated in the liquid crystal element 22 by this voltage application is set to ¼ wavelength, the linearly polarized light incident from the second polarizing plate 17 is rotated through 90 ° by passing through the twisted phase difference plate 12. Therefore, the light passes through the first polarizing plate 11,
A good white display can be obtained.

【０１２２】このように、第１の偏光板１１と散乱層１
４と、半透過反射層１３とカラーフィルタ１０を内在し
た液晶素子２２により、外光を用いる反射表示において
は良好なコントラストのカラー表示が可能であり、液晶
素子２２の下側に第１の位相差板１７と第２の位相差板
１８と第２の偏光板１６とバックライト１５を備えるこ
とで、外光が少ない環境ではバックライト１５を点灯す
ることで、良好なカラー表示が得られる単偏光板方式の
液晶表示装置を提供できる。Thus, the first polarizing plate 11 and the scattering layer 1
4, the liquid crystal element 22 having the semi-transmissive reflection layer 13 and the color filter 10 therein enables color display with good contrast in the reflective display using external light, and the first position below the liquid crystal element 22. By providing the phase difference plate 17, the second phase difference plate 18, the second polarizing plate 16, and the backlight 15, by turning on the backlight 15 in an environment with little external light, a good color display can be obtained. A polarizing plate type liquid crystal display device can be provided.

【０１２３】〔第４の実施の形態の変形例〕本発明の実
施の形態では、半透過反射層９を、厚さ０．０２μｍの
アルミニウム薄膜で形成したが、厚さ０．０３μｍ〜
０．０１μｍであれば、一部の光が透過して、ハ−フミ
ラーとすることが可能である。[Modification of Fourth Embodiment] In the embodiment of the present invention, the semi-transmissive reflective layer 9 is formed of an aluminum thin film having a thickness of 0.02 μm.
When the thickness is 0.01 μm, a part of light is transmitted and it is possible to form a half mirror.

【０１２４】また、本発明の実施の形態では、半透過反
射層９として、アルミニウム薄膜を用いたが、アルミニ
ウム合金や銀の薄膜や、反射率を改善するために、アル
ミニウムと無機酸化物の多層膜を用いることも可能であ
る。In the embodiment of the present invention, an aluminum thin film is used as the semi-transmissive reflective layer 9. However, a thin film of aluminum alloy or silver, or a multilayer of aluminum and an inorganic oxide in order to improve the reflectance. It is also possible to use a membrane.

【０１２５】また、本発明の実施の形態では、第１の位
相差板１７、第２の位相差板１８ともに、ポリカーボネ
イト（ＰＣ）を用い、遅相軸の交差角を６０°として、
広帯域１／４波長板を形成したが、第１の位相差板１７
と、第２の位相差板１８とにより、屈折率の波長依存性
が異なる材料を用いることによっても、広帯域１／４波
長板を形なすることができる。たとえば、第１の位相差
板１７にＰＣ、第２の位相差板１８にポリプロピレン
（ＰＰ）を用い、波長０．５５μｍでの、第１の位相差
板の位相差値を０．３６μｍ、第２の位相差板１８の位
相差を０．５μｍとし、遅相軸が直交するように配置す
れば、すべての波長にわたって位相差が１／４になる、
広帯域１／４波長板を形成することができる。Further, in the embodiment of the present invention, polycarbonate is used for both the first retardation plate 17 and the second retardation plate 18, and the crossing angle of the slow axes is set to 60 °.
Although the wideband quarter-wave plate is formed, the first retardation plate 17
The second retardation plate 18 and the second retardation plate 18 can form a broadband quarter-wave plate by using materials having different wavelength dependences of the refractive index. For example, PC is used for the first retardation plate 17, polypropylene (PP) is used for the second retardation plate 18, and the retardation value of the first retardation plate at a wavelength of 0.55 μm is 0.36 μm. If the phase difference of the second retardation plate 18 is 0.5 μm and the slow axes are arranged so as to be orthogonal to each other, the phase difference becomes 1/4 over all wavelengths.
A broadband quarter wave plate can be formed.

【０１２６】また、本発明の実施の形態では、カラーフ
ィルタ１０を第１の基板１に設けたが、第２の基板２の
内側で、第２の電極４と第２の基板２の間にカラーフィ
ルタ１０を形なすることも可能である。しかし、カラー
フィルタ１０を第１の基板に設ける方が、保護膜８を、
カラーフィルタ１０の平坦化と、半透過反射膜１３と第
１の電極３との絶縁層を兼ねることが可能となり、好ま
しい。Further, although the color filter 10 is provided on the first substrate 1 in the embodiment of the present invention, the color filter 10 is provided between the second electrode 4 and the second substrate 2 inside the second substrate 2. It is also possible to shape the color filter 10. However, when the color filter 10 is provided on the first substrate, the protective film 8 is
This is preferable because the color filter 10 can be flattened and can also serve as an insulating layer between the semi-transmissive reflective film 13 and the first electrode 3.

【０１２７】また、本発明の実施の形態では、カラーフ
ィルタ１０として、赤緑青の３色を用いたが、シアン、
イエロー、マゼンタの３色のカラーフィルタを用いて
も、同ように、明るいカラー表示が可能である。In the embodiment of the present invention, three colors of red, green and blue are used as the color filter 10, but cyan,
Similarly, bright color display is possible by using three color filters of yellow and magenta.

【０１２８】また、本発明の実施の形態では、カラーフ
ィルタ製造工程の洗浄ラインに耐えるように、半透過反
射層８の上に酸化シリコン（ＳｉＯ2 ）膜を形成した
が、アルミニウム薄膜の表面を陽極酸化処理で不活性化
させることも可能である。Further, in the embodiment of the present invention, the silicon oxide (SiO 2 ) film is formed on the semi-transmissive reflective layer 8 so as to endure the cleaning line in the color filter manufacturing process. It is also possible to inactivate by anodizing treatment.

【０１２９】[0129]

【発明の効果】以上の説明から明らかなように、本発明
によれば、第１の偏光板１１とねじれ位相差板１２と反
射層７を内在した液晶素子２０において、液晶素子２０
に対するねじれ位相差板１２のツイスト角、Δｎｄ値、
配置角を最適化し、ねじれ位相差板１２に対する第１の
偏光板１１の配置角を最適化している。このことによ
り、本発明では外光を用いて、高コントラストの反射表
示が得られる単偏光板方式の液晶表示装置を提供でき
る。As is apparent from the above description, according to the present invention, the liquid crystal element 20 including the first polarizing plate 11, the twisted phase difference plate 12 and the reflective layer 7 is the liquid crystal element 20.
The twist angle of the twisted phase difference plate 12 with respect to Δnd value,
The arrangement angle is optimized, and the arrangement angle of the first polarizing plate 11 with respect to the twisted phase plate 12 is optimized. As a result, the present invention can provide a single-polarizer type liquid crystal display device that can obtain high-contrast reflective display by using external light.

【０１３０】またさらに、本発明によれば、第１の偏光
板１１とねじれ位相差板１２と半透過反射層９を内在し
た液晶素子２１と、さらに第１の位相差板１７と第２の
偏光板１６とバックライト１５を備え、液晶素子２０に
対するねじれ位相差板のツイスト角、Δｎｄ値、配置角
を最適化し、ねじれ位相差板１２に対する第１の偏光板
１１の配置角を最適化することにより、外光による反射
表示と、バックライト照明による透過表示が可能で、か
つ、反射表示と透過表示の両方で高コントラストが得ら
れる単偏光板方式の液晶表示装置を提供できる。Furthermore, according to the present invention, the liquid crystal element 21 having the first polarizing plate 11, the twisted phase difference plate 12 and the semi-transmissive reflection layer 9 therein, the first phase difference plate 17 and the second phase difference plate 17 are provided. The polarizing plate 16 and the backlight 15 are provided, and the twist angle, Δnd value, and arrangement angle of the twisted phase difference plate with respect to the liquid crystal element 20 are optimized, and the arrangement angle of the first polarizing plate 11 with respect to the twisted phase difference plate 12 is optimized. As a result, it is possible to provide a liquid crystal display device of a single polarizing plate type that can perform reflective display by external light and transmissive display by backlight illumination, and that can obtain high contrast in both reflective display and transmissive display.

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

【図１】本発明の第１の実施の形態における液晶表示装
置の構成を示す断面図である。FIG. 1 is a sectional view showing a configuration of a liquid crystal display device according to a first embodiment of the present invention.

【図２】本発明の第１の実施の形態における液晶表示装
置の画素部を拡大した平面図である。FIG. 2 is an enlarged plan view of a pixel portion of the liquid crystal display device according to the first embodiment of the present invention.

【図３】本発明の第１の実施の形態における液晶表示装
置の配置関係を示す平面図である。FIG. 3 is a plan view showing an arrangement relationship of the liquid crystal display device according to the first embodiment of the present invention.

【図４】本発明の第２の実施の形態における液晶表示装
置の配置関係を示す平面図である。FIG. 4 is a plan view showing an arrangement relationship of a liquid crystal display device according to a second embodiment of the present invention.

【図５】本発明の第３の実施の形態における液晶表示装
置の構成を示す断面図である。FIG. 5 is a sectional view showing a configuration of a liquid crystal display device according to a third embodiment of the present invention.

【図６】本発明の第３の実施の形態における液晶表示装
置の画素部を拡大して示す平面図である。FIG. 6 is an enlarged plan view showing a pixel portion of a liquid crystal display device according to a third embodiment of the present invention.

【図７】本発明の第３の実施の形態における液晶表示装
置の配置関係を示す平面図である。FIG. 7 is a plan view showing an arrangement relationship of a liquid crystal display device according to a third embodiment of the present invention.

【図８】本発明の第４の実施の形態における液晶表示装
置の構成を示す断面図である。FIG. 8 is a sectional view showing a configuration of a liquid crystal display device according to a fourth embodiment of the present invention.

【図９】本発明の第４の実施の形態における液晶表示装
置の画素部を拡大して示す平面図である。FIG. 9 is an enlarged plan view showing a pixel portion of a liquid crystal display device according to a fourth embodiment of the present invention.

【図１０】本発明の第４の実施の形態における液晶表示
装置の配置関係を示す平面図である。FIG. 10 is a plan view showing an arrangement relationship of a liquid crystal display device according to a fourth embodiment of the present invention.

【図１１】本発明の実施の形態における液晶表示装置に
おいて、ねじれ位相差板のツイスト角とコントラストの
関係を示すグラフである。FIG. 11 is a graph showing the relationship between the twist angle of the twisted phase plate and the contrast in the liquid crystal display device according to the embodiment of the present invention.

【図１２】本発明の実施の形態における液晶表示装置に
おいて、ねじれ位相差板のΔｎｄ値とコントラストの関
係を示すグラフである。FIG. 12 is a graph showing the relationship between the Δnd value of the twisted phase difference plate and the contrast in the liquid crystal display device according to the embodiment of the present invention.

【図１３】本発明の実施の形態における液晶表示装置に
おいて、ねじれ位相差板の配置角αとコントラストの関
係を示すグラフである。FIG. 13 is a graph showing the relationship between the arrangement angle α of the twisted phase plate and the contrast in the liquid crystal display device according to the embodiment of the present invention.

【図１４】本発明の実施の形態における液晶表示装置に
おいて、第１の偏光板の配置角βとコントラストの関係
を示すグラフである。FIG. 14 is a graph showing the relationship between the arrangement angle β of the first polarizing plate and the contrast in the liquid crystal display device according to the embodiment of the present invention.

【図１５】本発明の実施の形態における液晶表示装置の
配置関係を定義するための平面図である。FIG. 15 is a plan view for defining a layout relationship of the liquid crystal display device according to the embodiment of the present invention.

【符号の説明】[Explanation of symbols]

１：第１の基板 ２：第２の基板
３：第１の電極 ４：第２の電極 ５：シール材
６：ネマチック液晶 ６ａ：下液晶分子配向方向 ６ｂ：上液晶分
子配向方向 ７：反射層 ８：保護膜 ９：半透過反射層（開口部付き） １０：カ
ラーフィルタ １１：第１の偏光板 １１ａ：第１の偏光板
の透過軸 １２：ねじれ位相差板 １２ａ：ねじれ位相
差板の下分子配向方向 １２ｂ：ねじれ位相差板の上分子配向方向 １３：半透過反射層（ハーフミラー） １
４：散乱層 １５：バックライト １６：第２の偏光板 １６ａ：第２の偏光板の透過軸 １７：第１
の位相差板 １７ａ：第１の位相差板の遅相軸 １８：第
２の位相差板 １８ａ：第２の位相差板の遅相軸 ２０、２
１、２２：液晶素子 Ｒ：赤フィルタ Ｇ：緑フィルタ
Ｂ：青フィルタ1: first substrate 2: second substrate
3: First electrode 4: Second electrode 5: Sealing material
6: Nematic liquid crystal 6a: Lower liquid crystal molecule alignment direction 6b: Upper liquid crystal molecule alignment direction 7: Reflective layer 8: Protective film 9: Semi-transmissive reflective layer (with opening) 10: Color filter 11: First polarizing plate 11a: Transmission axis 12 of first polarizing plate: Twisted retardation plate 12a: Lower molecular orientation direction of twisted retardation plate 12b: Upper molecular orientation direction of twisted retardation plate 13: Semi-transmissive reflective layer (half mirror) 1
4: Scattering layer 15: Backlight 16: Second polarizing plate 16a: Transmission axis of second polarizing plate 17: First
Retarder 17a: slow axis of first retarder 18: second retarder 18a: slow axis of second retarder 20, 2
1, 22: Liquid crystal element R: Red filter G: Green filter
B: Blue filter

フロントページの続き Ｆターム(参考） 2H049 BA02 BA06 BA07 BA08 BB03 BB63 BC22 2H089 QA16 RA10 SA04 SA07 TA05 TA14 2H091 FA08X FA08Z FA11X FA14Y FA15Y FA41Z FB08 FC01 FD06 FD10 GA02 GA16 HA10 KA02 KA03 LA17 Continued front page    F-term (reference) 2H049 BA02 BA06 BA07 BA08 BB03                       BB63 BC22                 2H089 QA16 RA10 SA04 SA07 TA05                       TA14                 2H091 FA08X FA08Z FA11X FA14Y                       FA15Y FA41Z FB08 FC01                       FD06 FD10 GA02 GA16 HA10                       KA02 KA03 LA17

Claims (8)

【特許請求の範囲】[Claims] 【請求項１】 反射層と第１の電極を有する第１の基板
と第２の電極を有する第２の基板と前記１対の基板の間
にツイスト角が１８０゜〜２６０゜にツイスト配向して
いるネマチック液晶を狭持してなる液晶素子と、 前記第２の基板の外側に設けるねじれ位相差板と、 ねじれ位相差板の外側に設ける第１の偏光板とを備え、 前記ねじれ位相差板のツイスト方向は、前記液晶素子と
逆ねじれ構造であり、 前記液晶素子の上液晶分子配向方向と前記ねじれ位相差
板の下分子配向方向とのなす角度αが８０゜〜１００゜
であり、 前記第１の偏光板の透過軸と前記ねじれ位相差板の上分
子配向方向との成す角度βが６０゜〜７５゜であり、 前記ねじれ位相差板のツイスト角Ｔｃは、前記液晶素子
のツイスト角Ｔｓの０．７倍〜０．８倍であり、 前記ねじれ位相差板の複屈折量を示すΔｎｄ値Ｒｃは前
記液晶素子のΔｎｄ値Ｒｓより０．１μｍ〜０．１５μ
ｍ小さいことを特徴とする液晶表示装置。1. A twist orientation having a twist angle of 180 ° to 260 ° between a first substrate having a reflective layer and a first electrode, a second substrate having a second electrode, and the pair of substrates. A twisted phase difference plate provided outside the second substrate and a first polarizing plate provided outside the twisted phase difference plate, wherein the twisted phase difference is provided. The twist direction of the plate has a reverse twist structure with respect to the liquid crystal element, and an angle α formed between the upper liquid crystal molecule alignment direction of the liquid crystal element and the lower molecule alignment direction of the twisted phase difference plate is 80 ° to 100 °, The angle β between the transmission axis of the first polarizing plate and the upper molecular orientation of the twisted phase difference plate is 60 ° to 75 °, and the twist angle Tc of the twisted phase difference plate is the twist of the liquid crystal element. 0.7 times to 0.8 times the angle Ts, and Gillet the Δnd value Rc indicating the birefringent amount of the phase difference plate 0.1μm~0.15μ than Δnd value Rs of the liquid crystal element
A liquid crystal display device characterized by being small. 【請求項２】 半透過反射層と第１の電極を有する第１
の基板と第２の電極を有する第２の基板と前記１対の基
板の間にツイスト角が１８０゜〜２６０゜にツイスト配
向しているネマチック液晶を狭持してなる液晶素子と、 前記第２の基板の外側に設けるねじれ位相差板と、 ねじれ位相差板の外側に設ける第１の偏光板と、 前記第１の基板の外側に設ける第１の位相差板と、 第１の位相差板の外側に設ける第２の偏光板と、 第２の偏光板の外側に設けるバックライトとを備え、 前記ねじれ位相差板のツイスト方向は前記液晶素子と逆
ねじれ構造であり、 前記液晶素子の上液晶分子配向方向と前記ねじれ位相差
板の下分子配向方向とのなす角度αが８０゜〜１００゜
であり、 前記第１の偏光板の透過軸と前記ねじれ位相差板の上分
子配向方向とのなす角度βが６０゜〜７５゜であり、 前記ねじれ位相差板のツイスト角Ｔｃは、液晶素子のツ
イスト角Ｔｓの０．７倍〜０．８倍であり、 前記ねじれ位相差板の複屈折量を示すΔｎｄ値Ｒｃは液
晶素子のΔｎｄ値Ｒｓより０．１μｍ〜０．１５μｍ小
さいことを特徴とする液晶表示装置。2. A first device having a semi-transmissive reflective layer and a first electrode.
A nematic liquid crystal having a twist orientation of 180 ° to 260 ° between a pair of substrates, a second substrate having a second electrode and a second electrode, and a pair of substrates. A twisted phase difference plate provided outside the second substrate, a first polarizing plate provided outside the twisted phase difference plate, a first phase difference plate provided outside the first substrate, and a first phase difference A second polarizing plate provided on the outer side of the plate, and a backlight provided on the outer side of the second polarizing plate, wherein the twisted phase difference plate has a twist direction opposite to that of the liquid crystal element. The angle α formed by the upper liquid crystal molecule orientation direction and the lower molecule orientation direction of the twisted retardation plate is 80 ° to 100 °, and the transmission axis of the first polarizing plate and the upper molecule orientation direction of the twisted retardation plate. The angle β formed by is 60 ° to 75 °, and the twist The twist angle Tc of the retardation plate is 0.7 to 0.8 times the twist angle Ts of the liquid crystal element, and the Δnd value Rc indicating the birefringence amount of the twisted retardation plate is more than the Δnd value Rs of the liquid crystal element. A liquid crystal display device characterized by being small by 0.1 μm to 0.15 μm. 【請求項３】 半透過反射層と第１の電極を有する第１
の基板と第２の電極を有する第２の基板と前記１対の基
板の間にツイスト角が１８０゜〜２６０゜にツイスト配
向しているネマチック液晶を狭持してなる液晶素子と、 前記第２の基板の外側に設けるねじれ位相差板と、 ねじれ位相差板の外側に設ける第１の偏光板と、 前記第１の基板の外側に設ける第１の位相差板と、 第１の位相差板の外側に設ける第２の位相差板と、 第２の位相差板の外側に設ける第２の偏光板と、 第２の偏光板の外側に設けるバックライトとを備え、 前記第１の位相差板の遅相軸と前記第２の位相差板の遅
相軸は概ね６０゜に交差しており、 第１の位相差板の位相差値は概ね１／４波長で、第２の
位相差板の位相差値が概ね１／２波長であり、 前記ねじれ位相差板のツイスト方向は前記液晶素子と逆
ねじれ構造であり、 前記液晶素子の上液晶分子配向方向と前記ねじれ位相差
板の下分子配向方向とのなす角度αが８０゜〜１００゜
であり、 前記第１の偏光板の透過軸と前記ねじれ位相差板の上分
子配向方向とのなす角度βが６０゜〜７５゜であり、 前記ねじれ位相差板のツイスト角Ｔｃは、前記液晶素子
のツイスト角Ｔｓの０．７倍〜０．８倍であり、前記ね
じれ位相差板の複屈折量を示すΔｎｄ値Ｒｃは前記液晶
素子のΔｎｄ値Ｒｓより０．１μｍ〜０．１５μｍ小さ
いことを特徴とする液晶表示装置。3. A first having a semi-transmissive reflective layer and a first electrode
A nematic liquid crystal having a twist orientation of 180 ° to 260 ° between a pair of substrates, a second substrate having a second electrode and a second electrode, and a pair of substrates. A twisted phase difference plate provided outside the second substrate, a first polarizing plate provided outside the twisted phase difference plate, a first phase difference plate provided outside the first substrate, and a first phase difference A second retardation plate provided on the outer side of the plate, a second polarizing plate provided on the outer side of the second retardation plate, and a backlight provided on the outer side of the second polarizing plate. The slow axis of the retardation plate and the slow axis of the second retardation plate intersect at about 60 °, and the retardation value of the first retardation plate is about ¼ wavelength and the second position. The retardation value of the retardation plate is about ½ wavelength, and the twist direction of the twisted retardation plate has a reverse twist structure with the liquid crystal element. The angle α between the upper liquid crystal molecule orientation direction of the liquid crystal element and the lower molecule orientation direction of the twisted phase difference plate is 80 ° to 100 °, and the transmission axis of the first polarizing plate and the twisted phase difference are The angle β with the upper molecular alignment direction of the plate is 60 ° to 75 °, and the twist angle Tc of the twisted phase difference plate is 0.7 times to 0.8 times the twist angle Ts of the liquid crystal element. A liquid crystal display device, wherein the Δnd value Rc indicating the birefringence amount of the twisted phase difference plate is smaller than the Δnd value Rs of the liquid crystal element by 0.1 μm to 0.15 μm. 【請求項４】 前記液晶素子のΔｎｄ値Ｒｓが、 ０．７５μｍ〜０．９μｍである請求項１、請求項２、
または請求項３に記載の液晶表示装置。4. The Δnd value Rs of the liquid crystal element is 0.75 μm to 0.9 μm.
Alternatively, the liquid crystal display device according to claim 3. 【請求項５】 前記第１の基板と前記第２の基板のどち
らか１方の基板に複数色のカラーフィルタを設ける請求
項１、請求項２、または請求項３に記載の液晶表示装
置。5. The liquid crystal display device according to claim 1, 2, or 3, wherein color filters of a plurality of colors are provided on either one of the first substrate and the second substrate. 【請求項６】 請求項１、請求項２または請求項３に記
載の液晶表示装置において、 前記第２の基板の外側に、散乱層を設けることを特徴と
する液晶表示装置。6. The liquid crystal display device according to claim 1, 2, or 3, wherein a scattering layer is provided outside the second substrate. 【請求項７】 前記半透過反射層として、 厚さ０．０３μｍ〜０．０１μｍの金属薄膜を用いる請
求項２、または請求項３に記載の液晶表示装置。7. The liquid crystal display device according to claim 2, wherein a metal thin film having a thickness of 0.03 μm to 0.01 μm is used as the semi-transmissive reflective layer. 【請求項８】 前記半透過反射層として、 画素毎に開口部を設けた金属薄膜を用いる請求項２、ま
たは請求項３に記載の液晶表示装置。8. The liquid crystal display device according to claim 2 or 3, wherein a metal thin film having an opening for each pixel is used as the semi-transmissive reflective layer.
JP30826699A 1999-10-29 1999-10-29 Liquid crystal display device Pending JP2003172925A (en)

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JP2005055709A (en) * 2003-08-05 2005-03-03 Stanley Electric Co Ltd Liquid crystal display device
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JPH08292413A (en) * 1995-04-20 1996-11-05 Casio Comput Co Ltd Liquid crystal display device
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JP3990754B2 (en) * 1996-10-02 2007-10-17 旭硝子株式会社 Reflective monochrome liquid crystal display
JP2878231B2 (en) * 1997-04-03 1999-04-05 新潟日本電気株式会社 Liquid crystal display
JP3774575B2 (en) * 1997-09-22 2006-05-17 株式会社日立製作所 Reflective liquid crystal display

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JP2002107726A (en) * 2000-09-29 2002-04-10 Asahi Glass Co Ltd Semitransmission type liquid crystal display device
JP2005055709A (en) * 2003-08-05 2005-03-03 Stanley Electric Co Ltd Liquid crystal display device
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US7327421B2 (en) 2004-02-19 2008-02-05 Citizen Holdings Co., Ltd. Liquid crystal display device
JP2006284928A (en) * 2005-03-31 2006-10-19 Seiko Epson Corp Liquid crystal display device, method for manufacturing liquid crystal display device, and electronic apparatus

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