JPH04343303A - Polarizing plate and liquid crystal display device - Google Patents
Polarizing plate and liquid crystal display deviceInfo
- Publication number
- JPH04343303A JPH04343303A JP3145428A JP14542891A JPH04343303A JP H04343303 A JPH04343303 A JP H04343303A JP 3145428 A JP3145428 A JP 3145428A JP 14542891 A JP14542891 A JP 14542891A JP H04343303 A JPH04343303 A JP H04343303A
- Authority
- JP
- Japan
- Prior art keywords
- film
- polarizing plate
- axis
- polarizer
- wavelength dispersion
- 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.)
- Granted
Links
- 239000004973 liquid crystal related substance Substances 0.000 title claims abstract description 23
- 238000007789 sealing Methods 0.000 claims abstract description 36
- 239000006185 dispersion Substances 0.000 claims abstract description 31
- 210000002858 crystal cell Anatomy 0.000 claims abstract description 9
- 238000010521 absorption reaction Methods 0.000 claims abstract description 8
- 230000010287 polarization Effects 0.000 abstract description 2
- 239000007788 liquid Substances 0.000 abstract 1
- 239000010408 film Substances 0.000 description 82
- 230000005540 biological transmission Effects 0.000 description 9
- 230000000694 effects Effects 0.000 description 7
- 239000004372 Polyvinyl alcohol Substances 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 5
- 229920000642 polymer Polymers 0.000 description 5
- 229920002451 polyvinyl alcohol Polymers 0.000 description 5
- 239000000853 adhesive Substances 0.000 description 4
- 230000001070 adhesive effect Effects 0.000 description 4
- 230000001747 exhibiting effect Effects 0.000 description 4
- 229920002284 Cellulose triacetate Polymers 0.000 description 3
- NNLVGZFZQQXQNW-ADJNRHBOSA-N [(2r,3r,4s,5r,6s)-4,5-diacetyloxy-3-[(2s,3r,4s,5r,6r)-3,4,5-triacetyloxy-6-(acetyloxymethyl)oxan-2-yl]oxy-6-[(2r,3r,4s,5r,6s)-4,5,6-triacetyloxy-2-(acetyloxymethyl)oxan-3-yl]oxyoxan-2-yl]methyl acetate Chemical compound O([C@@H]1O[C@@H]([C@H]([C@H](OC(C)=O)[C@H]1OC(C)=O)O[C@H]1[C@@H]([C@@H](OC(C)=O)[C@H](OC(C)=O)[C@@H](COC(C)=O)O1)OC(C)=O)COC(=O)C)[C@@H]1[C@@H](COC(C)=O)O[C@@H](OC(C)=O)[C@H](OC(C)=O)[C@H]1OC(C)=O NNLVGZFZQQXQNW-ADJNRHBOSA-N 0.000 description 3
- 230000005684 electric field Effects 0.000 description 3
- 238000002834 transmittance Methods 0.000 description 3
- ZCYVEMRRCGMTRW-UHFFFAOYSA-N 7553-56-2 Chemical compound [I] ZCYVEMRRCGMTRW-UHFFFAOYSA-N 0.000 description 2
- 239000003522 acrylic cement Substances 0.000 description 2
- 239000012790 adhesive layer Substances 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 229910052740 iodine Inorganic materials 0.000 description 2
- 239000011630 iodine Substances 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 229920000515 polycarbonate Polymers 0.000 description 2
- 239000004417 polycarbonate Substances 0.000 description 2
- 229920006289 polycarbonate film Polymers 0.000 description 2
- 239000002356 single layer Substances 0.000 description 2
- 239000004695 Polyether sulfone Substances 0.000 description 1
- 239000004642 Polyimide Substances 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- 239000004820 Pressure-sensitive adhesive Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229920000891 common polymer Polymers 0.000 description 1
- 230000001447 compensatory effect Effects 0.000 description 1
- 239000000975 dye Substances 0.000 description 1
- 238000004043 dyeing Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 229920001477 hydrophilic polymer Polymers 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 229920006255 plastic film Polymers 0.000 description 1
- 239000002985 plastic film Substances 0.000 description 1
- 229920003229 poly(methyl methacrylate) Polymers 0.000 description 1
- 229920001230 polyarylate Polymers 0.000 description 1
- 150000004291 polyenes Chemical class 0.000 description 1
- 229920006393 polyether sulfone Polymers 0.000 description 1
- -1 polyethylene terephthalate Polymers 0.000 description 1
- 229920000139 polyethylene terephthalate Polymers 0.000 description 1
- 239000005020 polyethylene terephthalate Substances 0.000 description 1
- 229920001721 polyimide Polymers 0.000 description 1
- 229920006254 polymer film Polymers 0.000 description 1
- 239000004926 polymethyl methacrylate Substances 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 239000004800 polyvinyl chloride Substances 0.000 description 1
- 229920000915 polyvinyl chloride Polymers 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—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
- 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
- G02F1/133637—Birefringent elements, e.g. for optical compensation characterised by the wavelength dispersion
Landscapes
- Polarising Elements (AREA)
- Liquid Crystal (AREA)
Abstract
Description
【0001】0001
【産業上の利用分野】本発明は、方位角や波長による偏
光性能の変化が少ない偏光板、及びそれを用いた視野角
の広さに優れる液晶表示装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polarizing plate whose polarization performance hardly changes due to azimuth or wavelength, and a liquid crystal display device using the same which has an excellent wide viewing angle.
【0002】0002
【従来の技術】画面の大型化や表示の高密度化など性能
アップが著しい液晶ディスプレイにあって、視野角の狭
さが依然として懸案のままであり、視野角の広い液晶表
示装置を実現する偏光板が求められて久しい。従来、偏
光板としては、二軸延伸トリアセチルセルロースフィル
ム等からなる等方性の、すなわち複屈折性を殆ど示さな
い封止フィルムを偏光子に接着したものが知られていた
。封止フィルムは、水分の侵入等を防止して偏光子の耐
久性を向上させるためのものである。しかしながら前記
したとおり、得られる液晶表示装置の視野角が狭い問題
点があつた。[Background Art] Although the performance of liquid crystal displays has been significantly improved due to larger screens and higher display densities, the narrow viewing angle remains a concern.Polarized light is used to realize liquid crystal display devices with wide viewing angles. It's been a long time since I've been looking for a board. BACKGROUND ART Conventionally, as a polarizing plate, one in which an isotropic sealing film made of a biaxially stretched triacetyl cellulose film or the like, that is, exhibiting almost no birefringence, is adhered to a polarizer has been known. The sealing film is for preventing moisture from entering and improving the durability of the polarizer. However, as mentioned above, there was a problem in that the viewing angle of the resulting liquid crystal display device was narrow.
【0003】0003
【発明が解決しようとする課題】本発明は、視野角の広
い液晶表示装置を得ることができる偏光板の開発を課題
とする。前記に鑑みて本発明者らは鋭意研究する中、偏
光板の透過軸が視野角、特にその方位角により、かつ波
長毎に変化し、これが液晶表示装置の視野角を狭くする
原因であることを究明し、かかる問題を克服すべく更に
研究を重ねて本発明をなすに至った。SUMMARY OF THE INVENTION An object of the present invention is to develop a polarizing plate that can provide a liquid crystal display device with a wide viewing angle. In view of the above, the present inventors conducted extensive research and found that the transmission axis of a polarizing plate changes depending on the viewing angle, especially its azimuth angle, and also for each wavelength, and this is the cause of narrowing the viewing angle of a liquid crystal display device. In order to overcome this problem, we conducted further research and came up with the present invention.
【0004】0004
【課題を解決するための手段】本発明は、偏光子の少な
くとも片側に、複屈折の波長分散特性が相違する複屈折
性フィルムの積層体からなる積層型封止フィルムを接着
してなり、その積層型封止フィルムにおける複屈折の波
長分散の小さいフィルムの遅相軸が、複屈折の波長分散
の大きいフィルムの遅相軸と直交すると共に、偏光子の
吸収軸と平行な状態にあることを特徴とする偏光板、及
びその偏光板を液晶セルの少なくとも片側に配置してな
ることを特徴とする液晶表示装置を提供するものである
。[Means for Solving the Problems] The present invention has a laminate type sealing film made of a laminate of birefringent films having different birefringent wavelength dispersion characteristics adhered to at least one side of a polarizer. In the laminated sealing film, the slow axis of the film with small wavelength dispersion of birefringence is perpendicular to the slow axis of the film with large wavelength dispersion of birefringence, and is parallel to the absorption axis of the polarizer. The present invention provides a polarizing plate according to the present invention, and a liquid crystal display device characterized in that the polarizing plate is disposed on at least one side of a liquid crystal cell.
【0005】[0005]
【作用】上記の構成により、複屈折性フィルムの進相軸
が方位角(傾斜角度)により変化することを利用して、
方位角による偏光子の透過軸の波長毎の変化を、積層型
封止フィルムの波長毎に異なる位相差の作用に基づいて
補償することができる。[Operation] With the above configuration, by utilizing the fact that the fast axis of the birefringent film changes depending on the azimuth angle (tilt angle),
Changes in the transmission axis of the polarizer for each wavelength due to the azimuth angle can be compensated based on the effect of the retardation that differs for each wavelength of the laminated sealing film.
【0006】[0006]
【実施例】本発明の偏光板は、偏光子に積層型封止フィ
ルムを接着したものである。図1、図3にその実施例を
例示した。1が積層型封止フィルム、2が接着剤層、3
が偏光子である。図1と図3より明らかな如く、積層型
封止フィルム1は少なくとも偏光子3の片側に設けられ
、必要に応じて両側に設けられる。[Example] The polarizing plate of the present invention is obtained by adhering a laminated sealing film to a polarizer. Examples thereof are illustrated in FIGS. 1 and 3. 1 is a laminated sealing film, 2 is an adhesive layer, 3
is a polarizer. As is clear from FIGS. 1 and 3, the laminated sealing film 1 is provided at least on one side of the polarizer 3, and if necessary, on both sides.
【0007】本発明において用いられる積層型封止フィ
ルムは、複屈折の波長分散特性が相違する複屈折性フィ
ルムを、その複屈折の波長分散の小さいフィルムと大き
いフィルムの遅相軸が直交するように積層したものであ
る。複屈折性フィルムの積層数は任意であるが、反射損
の抑制等による透明性の点より少ないほど好ましく、一
般には2枚ないし3枚程度の積層体とされる。図2に、
複屈折の波長分散特性が相違する2枚の複屈折性フィル
ム11,12を接着剤層2を介し積層してなる積層型封
止フィルム1を例示した。[0007] The laminated sealing film used in the present invention consists of birefringent films having different wavelength dispersion characteristics of birefringence, such that the slow axes of the films with small and large birefringent wavelength dispersions are perpendicular to each other. It is a layered structure. The number of laminated birefringent films is arbitrary, but it is preferable to have as few as possible from the viewpoint of transparency due to suppression of reflection loss, etc., and generally a laminated body of about two to three films is used. In Figure 2,
A laminated sealing film 1 is illustrated in which two birefringent films 11 and 12 having different birefringent wavelength dispersion characteristics are laminated with an adhesive layer 2 interposed therebetween.
【0008】本発明においては偏光子側の複屈折性フィ
ルムとして、ポリビニルアルコール系フィルムの如き封
止能力に乏しいポリマーからなるものも用いることがで
き、複屈折性フィルムを形成する高分子の種類について
は特に限定はない。透明性に優れる高分子が好ましく用
いられる。複屈折性フィルムは、例えば高分子フィルム
を一軸、ないし二軸等で延伸処理する方法などにより得
ることができる。In the present invention, as the birefringent film on the polarizer side, a film made of a polymer having poor sealing ability, such as a polyvinyl alcohol film, can also be used. There are no particular limitations. Polymers with excellent transparency are preferably used. The birefringent film can be obtained, for example, by uniaxially or biaxially stretching a polymer film.
【0009】封止能力に優れる複屈折性フィルムを形成
する一般的な高分子としては、例えばポリカーボネート
、トリアセチルセルロース、ポリメチルメタクリレート
、ポリエーテルサルホン、ポリエチレンテレフタレート
、ポリアリレート、ポリイミドなどがあげられる。Examples of common polymers that form birefringent films with excellent sealing ability include polycarbonate, triacetyl cellulose, polymethyl methacrylate, polyether sulfone, polyethylene terephthalate, polyarylate, and polyimide. .
【0010】複屈折性フィルムの積層は、例えば透明な
接着剤、ないし粘着剤を用いて行うことができる。その
接着剤等の種類については特に限定はない。複屈折性フ
ィルムの光学特性の変化防止の点より、硬化や乾燥の際
に高温のプロセスを要しないものが好ましく、長時間の
硬化処理や乾燥時間を要しないものが望ましい。なおか
かる接着剤、ないし粘着剤は積層型封止フィルムと偏光
子の接着にも好ましく用いられる。[0010] The birefringent films can be laminated using, for example, a transparent adhesive or adhesive. There are no particular limitations on the type of adhesive or the like. From the viewpoint of preventing changes in the optical properties of the birefringent film, it is preferable to use a film that does not require high-temperature processes during curing or drying, and desirably a film that does not require a long curing treatment or drying time. Note that such an adhesive or pressure-sensitive adhesive is also preferably used for adhering the laminated sealing film and the polarizer.
【0011】本発明において好ましく用いられる積層型
封止フィルムは、複屈折性フィルムの遅相軸方向、進相
軸方向、及び厚さ方向の屈折率をそれぞれnx、ny、
nzとした場合に、式:Q=(nx−nz)/(nx−
ny)で算出されるQ値(以下同じ)が0.5〜0.9
である複屈折の波長分散の小さいフィルムと、Q値が0
.1〜0.5である複屈折の波長分散の大きいフィルム
の積層体からなるものである。これにより、方位角によ
る偏光子の透過軸のズレを精度よく補償することができ
る。The laminated sealing film preferably used in the present invention has refractive indices of nx, ny, and ny in the slow axis direction, fast axis direction, and thickness direction of the birefringent film, respectively.
nz, the formula: Q=(nx-nz)/(nx-
Q value (the same applies hereafter) calculated by ny) is 0.5 to 0.9
A film with a small wavelength dispersion of birefringence and a Q value of 0
.. It is made of a laminate of films having a large wavelength dispersion of birefringence of 1 to 0.5. Thereby, it is possible to accurately compensate for a shift in the transmission axis of the polarizer due to the azimuth angle.
【0012】前記のQ値を示す複屈折性フィルムの形成
は例えば、ポリカーボネートの如く分子の配向方向に遅
相軸が表れて正の複屈折性を示す高分子を厚さ方向に電
界を印加して配向を制御しつつ硬化させ、そのフィルム
を延伸処理する方法などにより行うことができる。[0012] A birefringent film exhibiting the above-mentioned Q value can be formed by applying an electric field in the thickness direction of a polymer such as polycarbonate, which has a slow axis in the molecular orientation direction and exhibits positive birefringence. This can be carried out by, for example, curing the film while controlling its orientation, and then stretching the film.
【0013】ちなみに、正の複屈折性を示す高分子から
なるフィルムでは、完全一軸配向の場合にはnyとnz
が等しくなってQ値が1となり、二軸配向の場合にはQ
値が1より大きくなる。一方、ポリスチレンの如く分子
の配向方向に進相軸が表れて負の複屈折性を示す高分子
からなるフィルムでは、完全一軸配向の場合にはnxと
nzが等しくなってQ値が0となり、二軸配向の場合に
はQ値が負となる。そのためいずれの場合にも単層のフ
ィルムでは補償効果を発現させにくい。Incidentally, in a film made of a polymer exhibiting positive birefringence, ny and nz are completely uniaxially oriented.
are equal and the Q value is 1, and in the case of biaxial orientation, Q
The value becomes greater than 1. On the other hand, in a film made of a polymer such as polystyrene, which exhibits negative birefringence with a fast axis appearing in the molecular orientation direction, in the case of complete uniaxial orientation, nx and nz are equal and the Q value is 0. In the case of biaxial orientation, the Q value is negative. Therefore, in any case, it is difficult to produce a compensation effect with a single layer film.
【0014】すなわち前記において、クロスニコルに配
置した偏光子においてはその透過軸が傾斜軸(垂直立面
からの傾き角度)に対して垂直な方向に変化するが、前
記した正の複屈折系の完全一軸配向フィルムではその進
相軸の変化が偏光子の透過軸の変化と同じ方向となって
複屈折による補償効果が減殺されやすい。また、正の複
屈折系の二軸配向フィルムではその進相軸の変化が偏光
子の透過軸の変化よりも速くて複屈折は逆効果となりや
すく、補償効果を発現させにくい。他方、負の複屈折系
の完全一軸配向フィルムや二軸配向フィルムでは、その
遅相軸が偏光子の透過軸と逆方向に変化して、波長分散
等を含む位相差の影響を受けて視認性を低下させやすい
。その結果、いずれの場合にも単層のフィルムでは、視
認性に優れる視野角の拡大に有効な補償効果を発現させ
にくい。なお、Q値が0.5のフィルムの場合には遅相
軸と進相軸が傾斜によって殆ど変化しない。In other words, in the polarizer arranged in crossed nicols, its transmission axis changes in a direction perpendicular to the tilt axis (the tilt angle from the vertical plane), but in the case of the positive birefringence system described above, In a completely uniaxially oriented film, the change in its fast axis is in the same direction as the change in the transmission axis of the polarizer, which tends to reduce the compensation effect due to birefringence. Furthermore, in a biaxially oriented film with positive birefringence, the change in its fast axis is faster than the change in the transmission axis of the polarizer, so birefringence tends to have the opposite effect, making it difficult to develop a compensation effect. On the other hand, in a completely uniaxially oriented film or a biaxially oriented film with a negative birefringence system, the slow axis changes in the opposite direction to the transmission axis of the polarizer, and visibility is affected by the retardation including wavelength dispersion. It is easy to reduce the sex. As a result, in either case, a single layer film is difficult to exhibit a compensatory effect effective in widening the viewing angle with excellent visibility. Note that in the case of a film with a Q value of 0.5, the slow axis and the fast axis hardly change due to the tilt.
【0015】本発明において更に好ましく用いられる積
層型封止フィルムは、複屈折が長波長側ほど大きいもの
である。これにより、複屈折の波長分散に対する補償に
優れる積層型封止フィルムを得ることができる。かかる
特性を示す積層型封止フィルムの形成は例えば、複屈折
の波長分散が小さくて位相差が大きいフィルムと、複屈
折の波長分散が大きくて位相差が小さいフィルムとを組
合せることにより有利に行うことができる。[0015] A laminated sealing film more preferably used in the present invention has a birefringence that increases toward longer wavelengths. This makes it possible to obtain a laminated sealing film that is excellent in compensating for wavelength dispersion due to birefringence. Formation of a laminated sealing film exhibiting such characteristics is advantageous, for example, by combining a film with a small wavelength dispersion of birefringence and a large retardation and a film with a large wavelength dispersion of birefringence and a small retardation. It can be carried out.
【0016】すなわち、最適な補償は全ての波長におい
て位相差がその波長の1/2の場合に達成されるが、通
常の複屈折性フィルムでは短波長側ほど複屈折の波長分
散が大きく前記とは逆の関係にある。そのため、1枚の
複屈折性フィルムで複屈折の波長分散に対して補償する
ことは困難である。上記の如く、複屈折の波長分散が小
さくて位相差が大きいフィルムと、複屈折の波長分散が
大きくて位相差が小さいフィルムをその遅相軸を直交さ
せて積層することにより、複屈折が長波長側ほど大きい
ものとすることができ、それを用いて波長分散の影響を
小さくすることができる。なお可視光域に対処する点よ
りは面内の位相差が180〜370nmの積層型封止フ
ィルムとすることが好ましい。In other words, optimal compensation is achieved at all wavelengths when the retardation is 1/2 of the wavelength, but in a normal birefringent film, the wavelength dispersion of birefringence is larger on the shorter wavelength side. have the opposite relationship. Therefore, it is difficult to compensate for the wavelength dispersion of birefringence with a single birefringent film. As mentioned above, by laminating a film with a small wavelength dispersion of birefringence and a large retardation and a film with a large wavelength dispersion of birefringence and a small retardation with their slow axes perpendicular to each other, the birefringence can be lengthened. It can be made larger toward the wavelength side, and by using this, the influence of wavelength dispersion can be reduced. Note that from the standpoint of dealing with the visible light region, it is preferable to use a laminated sealing film with an in-plane retardation of 180 to 370 nm.
【0017】前記において、位相差は、複屈折性フィル
ムにおける遅相軸方向と進相軸方向との屈折率の差(△
n)と、複屈折性フィルムの厚さ(d)との積(△n・
d)で定義される。また面内の位相差は、積層型封止フ
ィルムを形成する各複屈折性フィルムにおける位相差の
重畳、ないし加減で定義される。[0017] In the above, the retardation is the difference in refractive index (△
n) and the thickness (d) of the birefringent film (△n・
d). Further, the in-plane retardation is defined by the superposition or adjustment of the retardations in each birefringent film forming the laminated sealing film.
【0018】本発明においては適宜な偏光子を用いるこ
とができ、特に限定はない。一般には、ポリビニルアル
コールの如き親水性高分子からなるフィルムをヨウ素の
如き二色性染料で処理して延伸したものや、ポリ塩化ビ
ニルの如きプラスチックフィルムを処理してポリエンを
配向させたものなどからなる偏光フィルムが用いられる
。[0018] In the present invention, any suitable polarizer can be used, and there is no particular limitation. In general, films made of hydrophilic polymers such as polyvinyl alcohol are treated with dichroic dyes such as iodine and stretched, or plastic films such as polyvinyl chloride are treated to orient polyene. A polarizing film is used.
【0019】本発明の偏光板は、積層型封止フィルムに
おける複屈折の波長分散の小さいフィルムの遅相軸が、
偏光子の吸収軸に対して平行となるように接着したもの
である。前記の遅相軸と吸収軸の平行状態は、積層型封
止フィルムにおける複屈折性フィルムの遅相軸間の直交
状態と同様に、作業精度等の点より完全な平行、ないし
直交状態を意味するものではないが、補償効果の点より
は交差角度が少ないほど、ないし90度に近いほど好ま
しい。なおその場合の複屈折性フィルムの遅相軸、ない
し偏光子の吸収軸は正面(方位角:0)に基づく。In the polarizing plate of the present invention, the slow axis of the film with small birefringence wavelength dispersion in the laminated sealing film is
It is attached so that it is parallel to the absorption axis of the polarizer. The above-mentioned parallel state of the slow axis and absorption axis means a completely parallel or orthogonal state from the point of view of work accuracy, similar to the orthogonal state between the slow axes of the birefringent film in the laminated sealing film. However, from the point of view of compensation effect, it is preferable that the intersection angle be smaller or closer to 90 degrees. In this case, the slow axis of the birefringent film or the absorption axis of the polarizer is based on the front (azimuth angle: 0).
【0020】本発明の液晶表示装置は、上記の偏光板を
液晶セルの片側、又は両側に配置したものである。かか
る液晶表示装置を図4に例示した。4が偏光板、5が液
晶セルである。用いる液晶セルは任意である。例えば、
薄膜トランジスタ型に代表されるアクティブマトリクス
駆動型のもの、ツイストネマチック型やスーパーツイス
トネマチック型に代表される単純マトリクス駆動型のも
のなどがあげられる。In the liquid crystal display device of the present invention, the above-mentioned polarizing plate is arranged on one side or both sides of a liquid crystal cell. An example of such a liquid crystal display device is shown in FIG. 4 is a polarizing plate, and 5 is a liquid crystal cell. Any liquid crystal cell may be used. for example,
Examples include active matrix drive type, typified by thin film transistor type, and simple matrix drive type, typified by twisted nematic type and super twisted nematic type.
【0021】実施例1
15kvの電界を印加しながら硬化させた後、120℃
で100%延伸させた一軸延伸ポリビニルアルコールフ
ィルム(nx:1.494、ny:1.487、nz:
1.489、Q値:0.76、位相差:982nm)と
、20kvの電界を印加しながら硬化させた後、155
℃で10%延伸させた一軸延伸ポリカーボネートフィル
ム(nx:1.591、ny:1.577、nz:1.
587、Q値:0.24、位相差:708nm)をそれ
らの遅相軸(延伸軸)を直交させてアクリル系粘着剤を
介し積層して積層型封止フィルム(面内位相差:274
nm)を形成した。次に、ポリビニルアルコールフィル
ムをヨウ素で染色したのち延伸処理してなる偏光子の両
側にアクリル系粘着剤を介して、前記の積層型封止フィ
ルムを接着して偏光板を得た。なお、一軸延伸ポリビニ
ルアルコールフィルムの遅相軸が偏光子の吸収軸と平行
となるように配置した。Example 1 After curing while applying an electric field of 15 kV, the temperature was 120°C.
Uniaxially stretched polyvinyl alcohol film (nx: 1.494, ny: 1.487, nz:
1.489, Q value: 0.76, phase difference: 982 nm), and after curing while applying an electric field of 20 kV, 155
A uniaxially stretched polycarbonate film (nx: 1.591, ny: 1.577, nz: 1.
587, Q value: 0.24, retardation: 708 nm) are laminated via an acrylic adhesive with their slow axes (stretching axes) perpendicular to each other to form a laminated sealing film (in-plane retardation: 274).
nm) was formed. Next, the above laminated sealing film was adhered to both sides of a polarizer made by dyeing a polyvinyl alcohol film with iodine and then stretching it, via an acrylic adhesive, to obtain a polarizing plate. The uniaxially stretched polyvinyl alcohol film was arranged so that its slow axis was parallel to the absorption axis of the polarizer.
【0022】比較例1
積層型封止フィルムに代えて、二軸延伸トリアセチルセ
ルロースフィルム(nx:1.503、ny:1.50
2、nz:1.501、Q値:8.00、位相差:10
nm、面内位相差:10nm)を封止フィルムに用いた
ほかは、実施例1に準じて偏光板を得た。Comparative Example 1 Instead of the laminated sealing film, a biaxially stretched triacetyl cellulose film (nx: 1.503, ny: 1.50
2, nz: 1.501, Q value: 8.00, phase difference: 10
A polarizing plate was obtained in the same manner as in Example 1, except that a polarizing film (in-plane retardation: 10 nm) was used for the sealing film.
【0023】比較例2
積層型封止フィルムに代えて、10kvの電界を印加し
ながら硬化させた後、155℃で15%延伸させた一軸
延伸ポリカーボネートフィルム(nx:1.588、n
y:1.583、nz:1.584、Q値:0.74、
位相差:278nm、面内位相差:278nm)を封止
フィルムに用いたほかは、実施例1に準じて偏光板を得
た。Comparative Example 2 Instead of a laminated sealing film, a uniaxially stretched polycarbonate film (nx: 1.588, n
y: 1.583, nz: 1.584, Q value: 0.74,
A polarizing plate was obtained according to Example 1, except that a retardation film (retardation: 278 nm, in-plane retardation: 278 nm) was used for the sealing film.
【0024】評価試験
位相差の波長分散
実施例1、比較例で用いた封止フィルムの位相差の波長
分散特性を図5に示した。Evaluation Test Wavelength Dispersion of Retardation The wavelength dispersion characteristics of the retardation of the sealing films used in Example 1 and Comparative Example are shown in FIG.
【0025】透過率の波長分散
実施例1、比較例で得た偏光板の吸収軸を傾斜軸に対し
て45度傾けて置いた場合について、水平面に対して偏
光板を60度傾斜させた場合、初期(傾斜しないとき)
の偏光板に対してクロスニコルに配置した、すなわち1
35度に置いた検光子に対する透過率を波長ごとに測定
し、その結果を図6に示した。なお、値が小さいほど偏
光板の透過軸の変化に対する補償効果の大きいことを意
味する。Wavelength dispersion of transmittance Regarding the case where the absorption axis of the polarizing plate obtained in Example 1 and Comparative Example is tilted at 45 degrees with respect to the tilt axis, the case where the polarizing plate is tilted at 60 degrees with respect to the horizontal plane , initial (when not tilted)
arranged in a crossed nicol manner with respect to the polarizing plate of 1
The transmittance with respect to an analyzer placed at 35 degrees was measured for each wavelength, and the results are shown in FIG. Note that the smaller the value, the greater the compensation effect for changes in the transmission axis of the polarizing plate.
【0026】視野角
ツイストネマチック型液晶セルの両側に、実施例1又は
比較例で得た偏光板を接着して表示装置を形成し、水平
方向と垂直方向についてコントラスト比が10:1以上
である範囲を調べた。
前記の結果を表1に示した。A display device is formed by adhering the polarizing plates obtained in Example 1 or Comparative Example to both sides of the viewing angle twisted nematic type liquid crystal cell, and the contrast ratio in the horizontal and vertical directions is 10:1 or more. I checked the range. The above results are shown in Table 1.
【表1】[Table 1]
【0027】[0027]
【発明の効果】本発明によれば、方位角による偏光子の
透過軸の波長毎の変化を補償でき、傾斜によって偏向性
能が変化しにくい偏光板を得ることができる。その結果
、かかる偏光板を液晶セルに適用して良好なコントラス
トを示す視野角の広さに優れる液晶表示装置を得ること
ができる。According to the present invention, it is possible to compensate for the change in the transmission axis of the polarizer for each wavelength due to the azimuth angle, and it is possible to obtain a polarizing plate whose deflection performance is not easily changed by tilting. As a result, by applying such a polarizing plate to a liquid crystal cell, it is possible to obtain a liquid crystal display device that exhibits good contrast and has a wide viewing angle.
【図1】偏光板の実施例の断面図。FIG. 1 is a cross-sectional view of an example of a polarizing plate.
【図2】積層型封止フィルムを例示した断面図。FIG. 2 is a cross-sectional view illustrating a laminated sealing film.
【図3】偏光板の他の実施例の断面図。FIG. 3 is a sectional view of another example of a polarizing plate.
【図4】液晶表示装置の実施例の断面図。FIG. 4 is a cross-sectional view of an embodiment of a liquid crystal display device.
【図5】位相差の波長分散を示したグラフ。FIG. 5 is a graph showing wavelength dispersion of phase difference.
【図6】透過率の波長分散を示したグラフ。FIG. 6 is a graph showing wavelength dispersion of transmittance.
1:積層型封止フィルム 11,12:複屈折性フィルム 3:偏光子 4:偏光板 5:液晶セル 1: Laminated sealing film 11, 12: Birefringent film 3: Polarizer 4: Polarizing plate 5: Liquid crystal cell
Claims (5)
波長分散特性が相違する複屈折性フィルムの積層体から
なる積層型封止フィルムを接着してなり、その積層型封
止フィルムにおける複屈折の波長分散の小さいフィルム
の遅相軸が、複屈折の波長分散の大きいフィルムの遅相
軸と直交すると共に、偏光子の吸収軸と平行な状態にあ
ることを特徴とする偏光板。1. A laminated sealing film made of a laminate of birefringent films having different birefringent wavelength dispersion characteristics is adhered to at least one side of a polarizer, and the birefringence of the laminated sealing film is A polarizing plate characterized in that a slow axis of a film having a small wavelength dispersion of birefringence is perpendicular to a slow axis of a film having a large wavelength dispersion of birefringence and parallel to an absorption axis of a polarizer.
軸方向、及び厚さ方向の屈折率をそれぞれnx、ny、
nzとした場合に、式:Q=(nx−nz)/(nx−
ny)で算出されるQ値が0.5〜0.9である複屈折
の波長分散の小さいフィルムと、前記Q値が0.1〜0
.5である複屈折の波長分散の大きいフィルムの積層体
からなる積層型封止フィルムを用いてなる請求項1に記
載の偏光板。2. The refractive indices of the birefringent film in the slow axis direction, fast axis direction, and thickness direction are respectively nx, ny,
nz, the formula: Q=(nx-nz)/(nx-
A film with a small birefringent wavelength dispersion whose Q value calculated by ny) is 0.5 to 0.9, and a film whose Q value is 0.1 to 0.
.. 2. The polarizing plate according to claim 1, comprising a laminate type sealing film made of a laminate of films having a large wavelength dispersion of birefringence of 5.
止フィルムを用いてなる請求項1に記載の偏光板。3. The polarizing plate according to claim 1, comprising a laminated sealing film in which the birefringence becomes larger on the longer wavelength side.
ある積層型封止フィルムを用いてなる請求項1に記載の
偏光板。4. The polarizing plate according to claim 1, comprising a laminated sealing film having an in-plane retardation of 180 to 370 nm.
少なくとも片側に配置してなることを特徴とする液晶表
示装置。5. A liquid crystal display device comprising the polarizing plate according to claim 1 disposed on at least one side of a liquid crystal cell.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP14542891A JP3165175B2 (en) | 1991-05-20 | 1991-05-20 | Polarizing plate and liquid crystal display |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP14542891A JP3165175B2 (en) | 1991-05-20 | 1991-05-20 | Polarizing plate and liquid crystal display |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH04343303A true JPH04343303A (en) | 1992-11-30 |
JP3165175B2 JP3165175B2 (en) | 2001-05-14 |
Family
ID=15385020
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP14542891A Expired - Lifetime JP3165175B2 (en) | 1991-05-20 | 1991-05-20 | Polarizing plate and liquid crystal display |
Country Status (1)
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JP (1) | JP3165175B2 (en) |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002228835A (en) * | 2001-01-30 | 2002-08-14 | Nitto Denko Corp | Polarizer, method for manufacturing the same and polarizing plate and liquid crystal display device using the same |
JP2006227651A (en) * | 2006-05-19 | 2006-08-31 | Nippon Synthetic Chem Ind Co Ltd:The | Non-oriented polyvinyl alcohol film for polarizing film, and polarizing film |
US7649599B2 (en) | 2002-04-04 | 2010-01-19 | Samsung Electronics Co., Ltd. | Liquid crystal display provided with compensation film |
JP2010271731A (en) * | 2010-07-15 | 2010-12-02 | Nitto Denko Corp | Polarizing plate |
JP2010282212A (en) * | 2010-07-15 | 2010-12-16 | Nitto Denko Corp | Polarizing plate |
JP2013061502A (en) * | 2011-09-14 | 2013-04-04 | Kuraray Co Ltd | Polyvinyl alcohol based retardation film |
US8435598B2 (en) | 2006-01-30 | 2013-05-07 | Nitto Denko Corporation | Method of producing a retardation plate, retardation plate, polarizing plate with a retardation plate, liquid crystal panel, and liquid crystal display apparatus |
KR20180092263A (en) | 2017-02-08 | 2018-08-17 | 데이진 가부시키가이샤 | Retardation film, process for producing the same, and display device using the same |
-
1991
- 1991-05-20 JP JP14542891A patent/JP3165175B2/en not_active Expired - Lifetime
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002228835A (en) * | 2001-01-30 | 2002-08-14 | Nitto Denko Corp | Polarizer, method for manufacturing the same and polarizing plate and liquid crystal display device using the same |
US7649599B2 (en) | 2002-04-04 | 2010-01-19 | Samsung Electronics Co., Ltd. | Liquid crystal display provided with compensation film |
US8435598B2 (en) | 2006-01-30 | 2013-05-07 | Nitto Denko Corporation | Method of producing a retardation plate, retardation plate, polarizing plate with a retardation plate, liquid crystal panel, and liquid crystal display apparatus |
JP2006227651A (en) * | 2006-05-19 | 2006-08-31 | Nippon Synthetic Chem Ind Co Ltd:The | Non-oriented polyvinyl alcohol film for polarizing film, and polarizing film |
JP2010271731A (en) * | 2010-07-15 | 2010-12-02 | Nitto Denko Corp | Polarizing plate |
JP2010282212A (en) * | 2010-07-15 | 2010-12-16 | Nitto Denko Corp | Polarizing plate |
JP2013061502A (en) * | 2011-09-14 | 2013-04-04 | Kuraray Co Ltd | Polyvinyl alcohol based retardation film |
KR20180092263A (en) | 2017-02-08 | 2018-08-17 | 데이진 가부시키가이샤 | Retardation film, process for producing the same, and display device using the same |
Also Published As
Publication number | Publication date |
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JP3165175B2 (en) | 2001-05-14 |
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