JPH0949925A - Visual field widening film and liquid crystal display using the same - Google Patents
Visual field widening film and liquid crystal display using the sameInfo
- Publication number
- JPH0949925A JPH0949925A JP7202238A JP20223895A JPH0949925A JP H0949925 A JPH0949925 A JP H0949925A JP 7202238 A JP7202238 A JP 7202238A JP 20223895 A JP20223895 A JP 20223895A JP H0949925 A JPH0949925 A JP H0949925A
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- Japan
- Prior art keywords
- film
- liquid crystal
- light
- visual field
- field
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- Liquid Crystal (AREA)
Abstract
Description
【0001】[0001]
【発明の属する技術分野】本発明は、プラズマディスプ
レー、薄膜ELディスプレーなどの平面表示板に適用さ
れ、画像の視野角を広げる視野拡大フィルムおよびそれ
を用いた液晶ディスプレーに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a field widening film applied to a flat display panel such as a plasma display and a thin film EL display to widen a viewing angle of an image, and a liquid crystal display using the field widening film.
【0002】[0002]
【従来の技術】従来、液晶ディスプレーでは、視野角の
狭さが欠点である。視野角とは、画像を良好に識別でき
る角度範囲のことである。表示画面を正面からみると、
良好な画像が得られるが、正面からずれて斜め方向から
みると、諧調反転、コントラストの低下が生じ、画像が
識別できなくなる。液晶ディスプレーでは、この現象が
正面から少しずれて観察するだけで発生する。通常は左
右方向の視野角を優先して液晶セルを組み立てているた
め、特に上下方向で視野角が狭くなっている。ちなみ
に、上方向で20°、下方向で5°と、正面からずれる
と、画像状態はすぐ不良になってしまう。2. Description of the Related Art Conventional liquid crystal displays have a drawback in that the viewing angle is narrow. The viewing angle is an angular range in which an image can be satisfactorily identified. Looking at the display screen from the front,
Although a good image can be obtained, when it is viewed from an oblique direction with the image shifted from the front, gradation inversion and deterioration in contrast occur, and the image cannot be identified. On a liquid crystal display, this phenomenon occurs only by observing slightly off the front. Since the liquid crystal cell is usually assembled by giving priority to the horizontal viewing angle, the viewing angle is narrowed especially in the vertical direction. By the way, if the image is shifted from the front by 20 ° in the upward direction and 5 ° in the downward direction, the image state becomes bad immediately.
【0003】そこで、画像の視野角を広げるため、液晶
表示パネルに使用される視野拡大フィルムは、以下に述
べるものが知られている。 (1)断面形状が蒲鉾型の非球面形状あるいは円形状を
した凸型マイクロレンズの集合体で構成されているシー
トであって、観察面側の偏光板と液晶セルの間に配置し
たものがある。特に、微小凸型マイクロレンズを千鳥状
に密に形成したものが、たとえば特開平6−27453
号公報、特開平6−27455号公報に開示されてい
る。また、微小凸型マイクロレンズを平行かつ等間隔に
密に配列したものが、たとえば特開平5−249453
号公報に開示されている。さらに、各画素に対応し基板
上に凹型レンズを形成するものが、たとえば特開平4−
194819号公報に開示されている。In view of this, in order to widen the viewing angle of an image, the following viewing field expansion films used in liquid crystal display panels are known. (1) A sheet composed of an assembly of convex microlenses whose cross-sectional shape is a kamaboko-shaped aspherical shape or circular shape, which is arranged between the polarizing plate on the observation surface side and the liquid crystal cell is there. In particular, a structure in which minute convex microlenses are densely formed in a zigzag pattern is disclosed in, for example, Japanese Patent Laid-Open No. 6-27453.
JP-A-6-27455. Further, a structure in which minute convex microlenses are closely arranged in parallel and at equal intervals is disclosed in, for example, Japanese Patent Laid-Open No. 5-249453.
No. 6,086,045. Further, one in which a concave lens is formed on a substrate corresponding to each pixel is disclosed in, for example, Japanese Patent Laid-Open No.
It is disclosed in Japanese Patent No. 194819.
【0004】(2)凹型のレンズシートを観察面側偏光
板の観察者側に設置するものが、たとえば特開平5−2
89071号公報に開示されている。 (3)球形微小粒子を液晶パネル上に配列し、その上に
各粒子に対応するように微小なホール(孔)のあるブラ
ックマスクを設けたことで視野角を拡大するものが、た
とえば特開平6−110053号公報に開示されてい
る。(2) One in which a concave lens sheet is installed on the viewer side of the viewing-side polarizing plate is disclosed in, for example, Japanese Patent Application Laid-Open No. 5-2.
It is disclosed in Japanese Patent No. 89071. (3) Spherical fine particles are arranged on a liquid crystal panel, and a black mask having fine holes (holes) corresponding to the respective particles is provided on the liquid crystal panel to enlarge the viewing angle. It is disclosed in Japanese Unexamined Patent Publication No. 6-110053.
【0005】[0005]
【発明が解決しようとする課題】ところが、前述した視
野拡大フィルムにおいては、次のような問題点があるこ
とが本発明者により見い出された。すなわち、マイクロ
レンズを密に成型したマイクロレンズアレイを液晶ディ
スプレーに使用すると、正面に透過される光は、マイク
ロレンズの頂点付近(傾斜角0°)の光だけになり、透
過光量は減少する。よって、液晶表示装置は暗くなり、
視認性が低下する。However, the inventor of the present invention has found that the above-mentioned field-enlarging film has the following problems. That is, when a microlens array in which microlenses are densely molded is used for a liquid crystal display, the light transmitted to the front is only the light near the apex of the microlens (inclination angle 0 °), and the amount of transmitted light decreases. Therefore, the liquid crystal display device becomes dark,
Visibility decreases.
【0006】また、視野拡大フィルムを、観察面側偏光
板の観察者側に設置すると、その外乱光の散乱や正反射
などが起こり、コントラストが低下する。本発明の目的
は、前述した問題点に鑑み、正面輝度を低下させること
なく、視野角を拡大することができる視野拡大フィルム
およびそれを用いた液晶ディスプレーを提供することに
ある。Further, when the field-enlarging film is installed on the viewer side of the viewing-side polarizing plate, the disturbance light is scattered or specularly reflected, and the contrast is lowered. In view of the above-mentioned problems, an object of the present invention is to provide a visual field expansion film capable of expanding the viewing angle without lowering the front luminance and a liquid crystal display using the same.
【0007】本発明の前記ならびにその他の目的と新規
な特徴は、本明細書の記述および添付図面から明らかに
なるであろう。The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.
【0008】[0008]
【課題を解決するための手段】本願において開示される
発明のうち、代表的なものの概要を簡単に説明すれば、
以下のとおりである。 (1)本発明の視野拡大フィルムは、基材上に曲面を有
する複数の凸状部あるいは凹状部が平面部を介して配列
され、光の複屈折位相差が面内方向および厚さ方向とも
60nm以下にしたものである。SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows. (1) In the field-of-view magnifying film of the present invention, a plurality of convex portions or concave portions having a curved surface are arranged on a base material via a flat portion, and the birefringence phase difference of light is in both the in-plane direction and the thickness direction. It is set to 60 nm or less.
【0009】(2)本発明の視野拡大フィルムは、前記
凸状部あるいは前記凹状部は、断面の半径が0〜100
μmの円形状に形成され、前記平面部の長さは、20〜
100μmに形成されたものである。 (3)本発明の視野拡大フィルムは、前記凸状部あるい
は前記凹状部の断面が矩形状を呈し、前記矩形の長辺お
よび短辺が20〜100μmに形成されたものである。(2) In the field-of-view enlarging film of the present invention, the convex portion or the concave portion has a cross-sectional radius of 0 to 100.
It is formed in a circular shape of μm, and the length of the plane portion is 20 to 20.
It is formed to 100 μm. (3) In the visual field expanding film of the present invention, the convex portion or the concave portion has a rectangular cross section, and the long side and the short side of the rectangle are formed to have a thickness of 20 to 100 μm.
【0010】(4)本発明の視野拡大フィルムは、前記
凸状部あるいは前記凹状部と前記平面部との間に曲率半
径が10〜300μmの曲線部を有するものである。 (5)本発明の液晶ディスプレーは、手段(1),
(2),(3)または(4)に記載の視野拡大フィルム
が、該視野拡大フィルムの凸状部あるいは凹状部を液晶
セル側に向けて、前記液晶セルの観察面側に装着された
ものである。(4) The visual field expanding film of the present invention has a curved portion having a radius of curvature of 10 to 300 μm between the convex portion or the concave portion and the flat portion. (5) The liquid crystal display of the present invention comprises the means (1),
The visual field expansion film according to (2), (3) or (4), which is mounted on the observation surface side of the liquid crystal cell with the convex portion or the concave portion of the visual field expansion film facing the liquid crystal cell side. Is.
【0011】本発明は、光拡大効果を確保したまま正面
の透過光量を下げないためには、光拡大部の他に水平面
を有する必要が生じる。光拡大部の割合が著しく減少す
ると正面方向以外の光量−拡大成分も減少してしまう
が、光拡大部の割合を最適化すれば、使用に支障のない
程度のコントラストを正面方向でも斜め方向でも得るこ
とが可能である。According to the present invention, it is necessary to have a horizontal plane in addition to the light expanding portion in order not to reduce the amount of transmitted light on the front side while ensuring the light expanding effect. When the proportion of the light expansion portion is significantly reduced, the light amount-expansion component other than in the front direction also decreases, but if the proportion of the light expansion portion is optimized, the contrast that does not hinder the use in both the front direction and the diagonal direction is obtained. It is possible to obtain.
【0012】水平部に入射した光は、約5%程度(該フ
ィルムなどの材質によって値は変化する)が光源側に戻
るが、残りは光路を曲げることなく直線的に透過する。
このように、複合型にすることで、正面の透過量を確保
しながら拡大の効果を得ることができる。水平面部の割
合は、バックライトの集光性や発光量、冷陰極管の数な
どによっても変化するが、全面積に対し50%程度あれ
ばよい。正面輝度を向上させるためには50%よりUP
させればよい。About 5% of the light incident on the horizontal portion (the value varies depending on the material of the film or the like) returns to the light source side, but the rest is linearly transmitted without bending the optical path.
In this way, by using the composite type, it is possible to obtain the effect of enlargement while securing the amount of transmission on the front side. The ratio of the horizontal plane portion varies depending on the light-collecting property of the backlight, the amount of light emission, the number of cold cathode tubes, and the like, but may be about 50% with respect to the entire area. UP from 50% to improve front brightness
You can do it.
【0013】本発明の凸状部は、バックライトからの集
光能力が高く、すなわち、平行性が高ければ高いほど、
水平方向の断面形状は円形に近くてよい。平行性が低く
斜めからの光が多いと、凸状部(以下、凹状部も含む。
便宜上凸状部と略記することがある)の一部で光が屈折
せずに全反射してバックライト側に戻ったり、円弧内で
複数回屈折するなどして散乱し拡大後の画像を白っぽく
させてしまう散乱光に変化してしまう可能性がある。The convex portion of the present invention has a high ability to collect light from the backlight, that is, the higher the parallelism, the more
The horizontal cross-sectional shape may be close to a circle. When the parallelism is low and a large amount of light is obliquely incident, a convex portion (hereinafter, a concave portion is also included.
(For convenience, it may be abbreviated as a convex portion for convenience.) Part of the light does not refract, but totally reflects back to the backlight side, or is refracted multiple times in an arc to scatter and magnify the enlarged image. There is a possibility that it will change to scattered light that causes it.
【0014】そのように入射時点で光量が低下した状態
で、凸状部断面を円形にすると、360°方位全てに光
を拡散しても、各方位での光量が低く、十分な拡大効果
が得られない。光源側で平行性の高い光を得られれば、
断面形状を円形にして全方位で均等な画質を得ることが
できる。さらに、平行性を上げた場合、光入射角度によ
って見え方が異なってしまう液晶の角度依存性の影響が
少なくなる。角度依存性の影響を受けない良好な画像を
全方位に拡大することができる。このように、集光性を
上げたバックライトを用い、液晶セル通過後に円形の凸
状で全方位に拡大するのが、良好な画像を各方位で見る
ために有効である。バックライト側の半値幅を±30°
以下にするためには、市販のプリズムシートを2枚以上
重ねればよい。If the cross section of the convex portion is circular with the light quantity reduced at the time of incidence, even if the light is diffused in all 360 ° azimuths, the light quantity in each azimuth is low and a sufficient expansion effect is obtained. I can't get it. If you can obtain highly parallel light on the light source side,
By making the cross-sectional shape circular, uniform image quality can be obtained in all directions. Further, when the parallelism is increased, the influence of the angle dependency of the liquid crystal, which looks different depending on the light incident angle, is reduced. A good image that is not affected by the angle dependence can be enlarged in all directions. In this way, it is effective to use a backlight having an improved light-condensing property and expand in all directions in a circular convex shape after passing through the liquid crystal cell in order to view a good image in each direction. The half value width on the backlight side is ± 30 °
In order to achieve the following, two or more commercially available prism sheets may be stacked.
【0015】プリズムシートは、たとえば3M社製の
「BEF90」を使用してもよい。さらに、集光性を上
げる場合は頂角が90°より小さいプリズムシートをバ
ックライト側に向け、導光板などにより補正して最適角
度で入射させれば、半値幅±20°程度の光が得られ
る。平行性が低い場合(最大光量に対する半値になるま
での角度範囲が±30°以上の場合、以下この角度範囲
を半値幅という)は、断面形状を左右方向、上下方向に
4辺を向けた長方形(正方形を含む)もしくは角に0〜
(長方形の短辺)/2の曲率半径Rを付けたり、面取り
をした長方形にすればよい。As the prism sheet, for example, "BEF90" manufactured by 3M may be used. Furthermore, in order to improve the light-collecting property, if a prism sheet with an apex angle smaller than 90 ° is turned to the backlight side and is corrected by a light guide plate and made to enter at an optimum angle, light with a half value width of ± 20 ° is obtained. To be When the parallelism is low (when the angle range to reach the half value with respect to the maximum light amount is ± 30 ° or more, this angle range is referred to as the half value width), the cross-sectional shape is a rectangle with the four sides facing in the left-right direction and the vertical direction. (Including square) or 0 at the corner
A radius of curvature R of (short side of rectangle) / 2 may be added, or a chamfered rectangle may be formed.
【0016】視野角を評価する場合、重要となる左右方
向の視野角と上下方向の視野角を重点的に向上できる。
ノートブックパソコンなどは蓋と液晶ディスプレーが表
裏一体化し、蓋を開けて液晶ディスプレーをみるように
なっている。蓋の開け方により画面法線方向が視野角方
向と一致しない場合があるため、上下方向の視野角を向
上させておく必要があるが、左右もずれてディスプレー
を斜め方向上方(下方)からみる人はいないため、斜め
方向の視野角の向上を左右や上下方向ほどに気にする必
要はない。このため、上下左右方向に視野を重点的に向
上した形態にすればよい。角のRが小さいほど指向性は
高まる。When evaluating the viewing angle, the horizontal viewing angle and the vertical viewing angle, which are important, can be focused and improved.
In notebook computers, the lid and the liquid crystal display are integrated into the front and back, and you can open the lid to view the liquid crystal display. Since the normal direction of the screen may not match the viewing angle direction depending on how the lid is opened, it is necessary to improve the viewing angle in the vertical direction. Since there are no people, it is not necessary to pay attention to the improvement of the viewing angle in the diagonal direction as much as in the left-right and up-down directions. For this reason, the visual field may be enhanced in the vertical and horizontal directions. The smaller the angle R, the higher the directivity.
【0017】バックライトの集光特性によっては左右方
向に予め光を拡大させたものがあるが、この場合は上下
方向に重点的に光を拡大させるよう上下方向に長辺をむ
け、短辺との比を大きくとるようにすればよい。場合に
よっては短辺同士をつなげて連続的にしてもよい。ただ
し、断面を略長方形にする場合は、おおよそ1人で使用
するパソコンなどが有効で、大人数でみるテレビなどに
は不向きである。後者で使用する場合は円形断面タイプ
が好ましい。Depending on the condensing characteristics of the backlight, there is one in which the light is previously expanded in the left-right direction. In this case, the long side is formed in the vertical direction so that the light is expanded in the vertical direction, and the short side is formed. The ratio should be large. Depending on the case, the short sides may be connected to be continuous. However, if the cross section is made to be a substantially rectangular shape, a personal computer or the like used by about one person is effective, and it is not suitable for a television set viewed by a large number of people. When used in the latter case, a circular cross section type is preferred.
【0018】形状の作製方法は、作製したい形状を金型
で作製してプレスで作製する方法や、金属ロールに所定
の形状を賦形しておき、加熱した樹脂に押し付ける方
法、光硬化樹脂に円形状あるいは長方形のマスクをして
硬化させる方法などがある。何れも一般的な賦形方法
で、作製は容易である。また、視野拡大フィルムは、そ
の光拡大部を液晶セル側に向けて、観察側の偏光素子と
液晶セルとの間に設置するのが望ましい。理由として
は、視野拡大フィルムなどを最外側に設置すると、対擦
傷性や反射防止処理などの表面処理を施さねばならず、
コスト的に高くなってしまったり、長期安定性の面から
信頼性が低いという問題が生じるためである。また、そ
の他に、文字バケ防止の効果も含んでいる。文字バケと
は文字が2重に見えるなど文字がボケて見える状態をい
う。文字バケは視野拡大フィルムなどが液晶セルに近い
ほど表れにくい。この理由からも視野拡大フィルムなど
は偏光子の間に挟み込む方が、偏光子より観察側に設置
するより品質がよくなる。以上の理由から視野拡大フィ
ルムなどは偏光子の間に挟み込むのが望ましい。The method for producing the shape includes a method of producing a desired shape with a die and a press, a method of shaping a predetermined shape on a metal roll and pressing it against a heated resin, and a method of applying a photocurable resin. There is a method of hardening with a circular or rectangular mask. All are common shaping methods and are easy to manufacture. In addition, it is desirable that the field-of-view enlarging film is installed between the polarizing element on the observation side and the liquid crystal cell with the light enlarging portion facing the liquid crystal cell side. The reason is that when a field-of-view expansion film is installed on the outermost side, surface treatment such as scratch resistance and antireflection treatment must be performed.
This is because the cost becomes high and the reliability is low in terms of long-term stability. In addition, the effect of preventing character blurring is also included. A character blur is a state in which a character appears to be out of focus, such as when the character appears double. The character blurring is less likely to appear as the field-of-view expansion film is closer to the liquid crystal cell. For this reason as well, it is better to sandwich a field-of-view magnifying film between the polarizers than to place the film on the observation side of the polarizer. For the above reasons, it is desirable to sandwich the field-of-view expansion film between the polarizers.
【0019】視野拡大フィルムなどを観察側の偏光素子
と液晶セルとの間に設置するときに最も問題となるの
は、光学的な歪である。光学歪がない状態とは、単に、
視野拡大フィルムが平坦であったり厚さにムラがない状
態ではなく、視野拡大フィルムに入射した偏光が透過し
た後も状態が変化しない状態をいう。具体的には視野拡
大フィルム内で複屈折が生じないことである。複屈折現
象が生じると、液晶を透過した光が不必要にねじられる
ため、観察側偏光子を透過した光は、ねらいとした配色
とは異なった色合いで表示されてしまう。Optical distortion is the most serious problem when a field-of-view magnifying film or the like is placed between the polarizing element on the observation side and the liquid crystal cell. The state without optical distortion is simply
It does not mean that the field-of-view magnifying film is flat or has a uniform thickness, but that it does not change even after the polarized light incident on the field-of-view magnifying film is transmitted. Specifically, no birefringence occurs in the field-of-view magnifying film. When the birefringence phenomenon occurs, the light that has passed through the liquid crystal is unnecessarily twisted, so that the light that has passed through the viewing-side polarizer is displayed in a different shade from the intended color scheme.
【0020】従って、視野拡大フィルム内の複屈折位相
差は小さくなければならない。複屈折位相差は視野拡大
フィルム面内および厚さ方向とも60nm以下がよく、
限りなく小さい方が好ましい。また、複屈折位相差は均
一である方がよい。所定の電圧と液晶のねじれから表示
の状態は設計されており、計算外の複屈折媒体が入った
場合、負荷電圧や液晶特性を設計し直さなければなら
ず、非常に複雑で時間の掛かる作業になる。いわゆるモ
デル変更である。また、物性的に対応ができない場合も
ある。光学歪がなければ現行の実機に搭載することが容
易である。Therefore, the birefringence phase difference in the field-of-view magnifying film must be small. The birefringence phase difference is preferably 60 nm or less both in the field of view expanding film and in the thickness direction,
It is preferably as small as possible. Further, the birefringence phase difference is preferably uniform. The display state is designed from the prescribed voltage and the twist of the liquid crystal, and if a birefringent medium other than the calculation is entered, the load voltage and liquid crystal characteristics must be redesigned, which is a very complicated and time-consuming operation. become. This is a so-called model change. In addition, there are cases where it is not possible to respond physically. If there is no optical distortion, it is easy to mount on the current actual equipment.
【0021】光学歪のない視野拡大フィルムなどを作製
する方法としては、一般的な手法を用いて作製すること
ができる。たとえば凹凸形状を賦形した視野拡大フィル
ムを加熱する方法がある。視野拡大フィルム樹脂のガラ
ス転移点以上に加熱すると、視野拡大フィルム内に残留
している歪は緩和される。温度は高い方が効果的である
が、高すぎると、溶融したり視野拡大フィルムが波打っ
たりするので注意が必要である。As a method for producing a field-enlarging film or the like having no optical distortion, a general method can be used. For example, there is a method of heating a visual field expansion film having an uneven shape. When the glass is heated above the glass transition point of the visual field expanding film resin, the strain remaining in the visual field expanding film is relaxed. A higher temperature is more effective, but if it is too high, it may melt or the corrugated field-of-view film may wavy, so be careful.
【0022】その他の方法では、溶剤キャスト法による
視野拡大フィルムの製膜がある。溶剤キャストは、普通
ベースフィルムの上に作ろうとする樹脂を塗工する。塗
工した樹脂を乾燥ゾーンで加熱乾燥した後、ベースフィ
ルムから剥離する。乾燥はベースフィルムの上で行なわ
れるため、乾燥工程における張力は全てベースフィルム
に負荷され、作製しようとする視野拡大フィルムにはか
からない。これにより、歪のない視野拡大フィルムを作
製することができる。Another method is to form a visual field expansion film by a solvent casting method. In the solvent casting, the resin to be made is usually applied on the base film. The applied resin is heated and dried in the drying zone, and then peeled off from the base film. Since the drying is performed on the base film, all the tension in the drying process is applied to the base film and does not apply to the visual field expansion film to be produced. This makes it possible to produce a visual field-enlarging film without distortion.
【0023】視野拡大フィルムに使用する材質は、法線
方向の平行光線透過率が低下しない半透明体または透明
な材質で屈折率が1.0以上ある材料、たとえば、ポリ
カーボネート、ポリメチルメタクリレート、ポリエチレ
ンテレフタレート、ポリエーテルサルホン、ポリサルホ
ン、ポリスチレン、ポリ塩化ビニル、ポリ塩化ビニリデ
ン、ポリテトラフルオロエチレン、ポリフッ化ビニリデ
ン、ポリフッ化ビニル、ポリエチレン、ポリビニルアル
コール、ポリプロピレン、ポリアクリルニトリル、ポリ
酢酸ビニル、ナイロン6およびナイロン66などがあ
る。The material used for the field-of-view magnifying film is a semitransparent material in which the parallel light transmittance in the normal direction does not decrease, or a transparent material having a refractive index of 1.0 or more, such as polycarbonate, polymethylmethacrylate, or polyethylene. Terephthalate, polyether sulfone, polysulfone, polystyrene, polyvinyl chloride, polyvinylidene chloride, polytetrafluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, polyethylene, polyvinyl alcohol, polypropylene, polyacrylonitrile, polyvinyl acetate, nylon 6 and There are nylon 66 and the like.
【0024】また、熱可塑性樹脂以外にも、紫外線硬化
樹脂他の光硬化性樹脂、エポキシ樹脂、メラミン樹脂、
尿素樹脂およびフェノール樹脂などの熱硬化性樹脂を用
いてもよい。また、ソーダライムガラス等のガラスでも
よく、プラスチックの表面にSiO2 コートや耐湿性な
どの耐久性に係る保護コート処理がなされていてもよ
い。処理の方法は塗布であっても蒸着やスパッタ、イオ
ンビーム等の方法でもよい。また、偏光素子に張付ける
よう平滑面に複屈折性を有しない粘着剤を付与してもよ
い。In addition to thermoplastic resins, UV curable resins and other photocurable resins, epoxy resins, melamine resins,
Thermosetting resins such as urea resin and phenol resin may be used. Further, glass such as soda lime glass may be used, and the surface of the plastic may be subjected to SiO 2 coating or a protective coating treatment relating to durability such as moisture resistance. The treatment method may be coating, vapor deposition, sputtering, ion beam, or the like. Further, a pressure-sensitive adhesive having no birefringence may be attached to the smooth surface so that the pressure-sensitive adhesive is attached to the polarizing element.
【0025】また、粘着剤、接着剤を塗布する場合は、
平滑面に塗布する場合は前記の複屈折に注意すれば特に
問題はないが、形状を付与した面(賦形面)に塗布する
場合は付与した凹凸を埋めない方が望ましい。凹凸形状
を埋めてしまうと拡大効果が減少してしまうためであ
る。止むを得ず凹凸形状内に塗布する場合は、視野拡大
フィルムより屈折率が小さいことが必要である。また、
極力、屈折率差が大きい方がよい。屈折率が小さい粘着
剤(接着剤)としては、フッ素系粘着剤などが好まし
い。When applying a pressure sensitive adhesive or an adhesive,
When applied to a smooth surface, there is no particular problem if attention is paid to the above-mentioned birefringence, but when applied to a surface having a shape (shaped surface), it is preferable not to fill the unevenness provided. This is because if the uneven shape is filled, the expansion effect is reduced. When it is unavoidable to apply it in the uneven shape, it is necessary that the refractive index is smaller than that of the visual field expanding film. Also,
It is better that the difference in refractive index is as large as possible. As the pressure-sensitive adhesive (adhesive) having a small refractive index, a fluorine-based pressure-sensitive adhesive or the like is preferable.
【0026】また、光拡大部の断面形状は凸状でも凹状
でもよい。また、光拡大部と水平部とを交互に形成して
いるほうがよく、その割合は用途に応じて最適値を決め
る。また、凸状部または凹状部と水平面との接触部は面
取りやRが付いていてもよく、Rが斜面の殆どを占めて
いてもよい。理由は斜面が一直線のみで構成されている
と、拡大される視野の方向が一方向に決定してしまうた
めで、その拡大方向以外に光が拡大されない恐れがあ
る。The cross-sectional shape of the light expanding portion may be convex or concave. Further, it is better to alternately form the light expanding portion and the horizontal portion, and the ratio thereof is determined to be the optimum value according to the application. Further, the contact portion between the convex portion or the concave portion and the horizontal surface may be chamfered or R, and R may occupy most of the slope. The reason is that if the slope is composed of only one straight line, the direction of the field of view to be expanded is determined to be one direction, and there is a risk that the light will not be expanded in any direction other than that direction.
【0027】連続的に光が拡大されないと、特定方向で
光量が著しく低い暗黒点が生じる可能性があるためであ
る。また、垂直方向断面形状は、その用途により中心線
(法線方向)からみて必ずしも対称形状でなくてもよ
い。中心線からみて上側のみに光を拡大させたいときに
は、法線方向からの開き角度を上側において大きくした
斜面を作り、下側の斜面を小さくした形状にすればよ
い。This is because if the light is not continuously expanded, dark spots having a remarkably low light amount may occur in a specific direction. Further, the vertical cross-sectional shape does not necessarily have to be symmetrical when viewed from the center line (normal direction) depending on its application. When it is desired to expand the light only to the upper side with respect to the center line, it is sufficient to form a slope having a larger opening angle from the normal direction on the upper side and reduce the lower slope.
【0028】この意味からいえば、片方向のみに斜面を
もち対称側を垂直にした1/4球形状などであっても、
用途に応じて使用すれば、十分な効果が得られる。賦形
面は、液晶セル側に向いていることが望ましいが、文字
バケが気にならないようであれば、観察者側に向いても
構わない。凸状部は水平面部を挟んで等間隔に並んでい
ることが望ましいが、断続的であったり、一定距離毎に
千鳥であったりしてもよい。凸状部は頂上に水平部を有
していてもよい。また、水平部と凸状部頂上の水平部と
合わせて所望の水平面の割合(対視野拡大フィルム全
面)を計算してよい。In this sense, even if it is a quarter-sphere shape having a sloping surface only in one direction and the symmetry side being vertical,
Sufficient effect can be obtained if used according to the application. It is desirable that the shape-imparting surface faces the liquid crystal cell side, but it may be facing the observer side if character blurring is not a concern. The convex portions are preferably arranged at equal intervals across the horizontal surface portion, but they may be intermittent or staggered at regular intervals. The convex portion may have a horizontal portion at the top. Further, the ratio of the desired horizontal surface (the entire surface of the film for enlarging the visual field) may be calculated by combining the horizontal portion and the horizontal portion on the top of the convex portion.
【0029】凸状部を垂直方向に切断したとき、斜面の
断面形状は曲面を有していることが望ましい。直線部が
多いと特定方向のみに光が配光され、その他の部分は暗
黒領域になる恐れがあるので、極力曲面で構成されてい
るのがよい。また、1レンズ部と1水平面を合わせたも
のを1ピッチと呼ぶが、1ピッチは液晶セルの1画素よ
り小さいことがよく、1ピッチが2〜3画素程度であれ
ば、液晶セルより大きくしてもよい。小さい場合は、1
画素の大きさが視野拡大フィルム等のピッチの整数倍に
ならないことが必要である。仮になってしまったとき
は、5倍以上がよい。5倍以下で整数倍になると、モワ
レ縞(干渉縞)が発生し易くなるためである。When the convex portion is cut in the vertical direction, it is desirable that the cross-sectional shape of the slope has a curved surface. If there are many straight portions, light may be distributed only in a specific direction, and the other portions may become dark areas. Therefore, it is preferable that the curved portions be formed as much as possible. Further, one lens portion and one horizontal surface are called one pitch, and one pitch is preferably smaller than one pixel of the liquid crystal cell, and if one pitch is about 2 to 3 pixels, it is set larger than the liquid crystal cell. May be. 1 if small
It is necessary that the pixel size does not become an integral multiple of the pitch of the field-of-view expansion film or the like. If it happens, 5 times or more is better. This is because moire fringes (interference fringes) are likely to occur when the number is 5 times or less and becomes an integral multiple.
【0030】また、視野拡大フィルムを液晶ディスプレ
ーに用いる場合は、視野角を広げたい方向に対して視野
拡大フィルムの稜線が垂直になるように配置すればよ
い。その際、レンズ面は液晶セル側となり、観察者側が
平面となるように配置する。視野角を広げたい方向が2
方向である場合は、視野拡大フィルムを2枚用いればよ
い。また、同一方向に2枚以上重ねて用いてもよい。視
野拡大フィルムを複数枚同時に使用する場合も、画素ピ
ッチとレンズピッチの関係と同じようにモワレ縞が認識
し難いように、複数枚のレンズピッチと画素ピッチを組
み合わせるとよい。When the field-of-view magnifying film is used in a liquid crystal display, the ridgeline of the field-of-view magnifying film may be perpendicular to the direction in which the viewing angle is desired to be widened. At that time, the lens surface is arranged so that the liquid crystal cell side is located and the observer side is a flat surface. 2 directions to widen the viewing angle
If it is the direction, two field-of-view magnifying films may be used. Also, two or more sheets may be stacked in the same direction. Even when a plurality of visual field expansion films are used at the same time, it is preferable to combine a plurality of lens pitches and pixel pitches so that Moire fringes are difficult to recognize like the relationship between pixel pitches and lens pitches.
【0031】視野拡大フィルムを液晶ディスプレーに実
装するときは、本体に積層するだけでよい。固定したい
ときは、レンズ面全体を粘着層で覆い液晶セルに取り付
けてもよい。また、粘着層は数カ所でも端部だけでもよ
い。レンズ面全体を粘着層で覆う場合は、光学素子と粘
着層の屈折率差は大きい方が好ましい。固定方法として
は、端部を利用したネジ止め、はめ込みなどの方法でも
よい。平面側、つまり観察者側偏光板側は、従来通りの
偏光板装着方法でよい。When the field-of-view magnifying film is mounted on the liquid crystal display, it need only be laminated on the main body. When it is desired to fix, the whole lens surface may be covered with an adhesive layer and attached to the liquid crystal cell. Further, the adhesive layer may be provided at several places or only at the ends. When the entire lens surface is covered with an adhesive layer, the difference in refractive index between the optical element and the adhesive layer is preferably large. As a fixing method, a method such as screwing using the end portion or fitting may be used. On the plane side, that is, on the observer side polarizing plate side, a conventional polarizing plate mounting method may be used.
【0032】[0032]
【作 用】前述した手段によれば、曲面を有する複数の
凸状部あるいは凹状部が平面部を介して配列されたの
で、視野拡大フィルムは屈折効果を持たない平面部を持
っており、通常の液晶ディスプレーで認識できていた視
野角範囲の光量を比較的損なうことなく、凸状部あるい
は凹状部により視野角が拡大する。[Operation] According to the above-mentioned means, since the plurality of convex portions or concave portions having curved surfaces are arranged through the flat portion, the field-of-view magnifying film has a flat portion that does not have a refraction effect. The viewing angle is expanded by the convex portion or the concave portion without relatively impairing the amount of light in the viewing angle range that can be recognized by the liquid crystal display.
【0033】視野拡大フィルムに平行光線を入射した場
合、平行光線透過光と拡散光そして平行光線透過光と拡
散光の光の強度をなだらかにつなぐ光に分けて考えられ
る。そのため、正面の光量は下面と平行な平面部で、視
野角拡大の大きさは凸状部あるいは凹状部で調節され
る。平面部と凸状部あるいは凹状部をつなぐ部分は曲線
部で構成されているので、光線の出射光分布が連続的に
なり、文字バケ、画像バケが生じない。When parallel light rays are incident on the field-of-view enlarging film, it is considered that the parallel light transmitted light and the diffused light, and the parallel light transmitted light and the diffused light are divided into light that gently connects. Therefore, the amount of light on the front surface is adjusted in the plane portion parallel to the lower surface, and the magnitude of the viewing angle expansion is adjusted in the convex portion or the concave portion. Since the portion connecting the flat portion and the convex portion or the concave portion is composed of the curved portion, the outgoing light distribution of the light rays is continuous, and character blurring and image blurring do not occur.
【0034】液晶ディスプレーに視野拡大フィルムを1
枚または2枚以上組み込むことで、容易に視野が拡大さ
れ、新しい液晶セルを設計および製造するような複雑な
工程を必要としない。そのため、信頼性が高く、視野の
広い液晶ディスプレーが容易に得られる。1 field-of-view expansion film on the liquid crystal display
By incorporating one or more sheets, the field of view is easily expanded, and complicated steps such as designing and manufacturing a new liquid crystal cell are not required. Therefore, a liquid crystal display having high reliability and a wide field of view can be easily obtained.
【0035】[0035]
【実施例】以下、本発明の実施例を図面に基づいて詳細
に説明する。なお、実施例を説明するための全図におい
て同一の機能を有するものは同一の符号を付け、その繰
り返しの説明は省略する。 〔実施例1〕図1は本発明の第1実施例に係る視野拡大
フィルムの断面図、図2は本発明の第1実施例に係る視
野拡大フィルムの平面図、図3は本発明の第1実施例に
係る視野拡大フィルムを実装した液晶ディスプレーの概
略断面図である。Embodiments of the present invention will be described below in detail with reference to the drawings. In all the drawings for explaining the embodiments, those having the same function are designated by the same reference numerals, and the repeated description thereof will be omitted. [Embodiment 1] FIG. 1 is a sectional view of a visual field expanding film according to a first embodiment of the present invention, FIG. 2 is a plan view of a visual field expanding film according to a first embodiment of the present invention, and FIG. It is a schematic sectional drawing of the liquid crystal display which mounted the visual field expansion film which concerns on 1 Example.
【0036】溶剤キャスト法または150°Cで10分
間加熱して応力を除去して形成した100μm厚の基
材、たとえばポリカーボネート樹脂上に、感光性樹脂、
たとえば紫外線硬化樹脂を80μm厚塗布し、さらにそ
の上に、開放部分の円弧の直径が40μmで、上下方向
に等間隔に50μmピッチで配置されているフォトマス
クを設置した。A 100 μm thick base material formed by removing the stress by solvent casting or heating at 150 ° C. for 10 minutes, for example, a polycarbonate resin, a photosensitive resin,
For example, an ultraviolet curable resin was applied to a thickness of 80 μm, and a photomask having an open circular arc diameter of 40 μm and arranged at equal intervals in the vertical direction at a pitch of 50 μm was placed thereon.
【0037】その後、紫外線照射装置(超高圧水銀灯)
の光源より300mJ/cm2 の紫外線を30秒間照射
し、フォトマスクにより紫外線硬化樹脂を選択的に露光
した。次に、紫外線硬化樹脂をアルカリ溶液を用いて2
分間現像した後、100mJ/cm2 の紫外線で20秒間
再露光して、未反応部分を硬化させ、形状を固定した。
現像後の形状は、図1および図2に示すように、20μ
mの平面部aを介して、断面形状において、上面平坦部
bが20μm、斜面曲線部cが60μm(左右各30μ
m)、溝の深さdが40μmの上面が平坦な半円球形状
の凸状部1aを配列した視野拡大フィルム1が得られ
た。After that, an ultraviolet irradiation device (super high pressure mercury lamp)
UV light of 300 mJ / cm 2 was irradiated for 30 seconds from the above light source, and the UV curable resin was selectively exposed by a photomask. Next, the UV curable resin is used to
After developing for 1 minute, the unreacted portion was cured by re-exposure with an ultraviolet ray of 100 mJ / cm 2 for 20 seconds to fix the shape.
The shape after development is 20 μm as shown in FIGS.
In the cross-sectional shape through the flat surface portion a of m, the upper surface flat portion b is 20 μm, and the sloped curved portion c is 60 μm (each side is 30 μm.
m), a field-enlarging film 1 was obtained in which hemispherical convex portions 1a each having a flat upper surface and having a groove depth d of 40 μm were arranged.
【0038】この視野拡大フィルム1を、図3に示すよ
うに、TFT−LCDに取付けた。液晶ディスプレー
は、長辺1灯式エッジライト型10.4inchTFTカラ
ー液晶ディスプレーであり、画素形状はよこが280μ
m、たてが320μmの長方形を呈する。液晶ディスプ
レーは、TN液晶セル2の前面(観察者側)に視野拡大
フィルム1,偏光板3が順次配置され、TN液晶セル2
の後面に偏光板3,バックライト4が順次配設されてい
る。This field-of-view enlarging film 1 was attached to a TFT-LCD as shown in FIG. The liquid crystal display is a long side single light type edge light type 10.4inch TFT color liquid crystal display, and the pixel shape is 280μ in the horizontal direction.
m, and the vertical length is 320 μm. The liquid crystal display includes a TN liquid crystal cell 2 in which a visual field expansion film 1 and a polarizing plate 3 are sequentially arranged on the front surface (observer side) of the TN liquid crystal cell 2.
A polarizing plate 3 and a backlight 4 are sequentially arranged on the rear surface of the rear panel.
【0039】また、視野拡大フィルム1は、その凸状部
1aがTN液晶セル2側を向くように取付けた。さら
に、視野拡大フィルム1は凸状部1aの配列方向が画面
左右方向に向くように設置した。従って、視野の拡大は
1画素に対して約1凸状以上が対応して行なわれる。表
示素子は、市販のTFT−LCDテレビ、6E−C3
(シャープ製)を使用した。市販状態では、バックライ
ト側に白色の拡散体のみ配置されており、集光性が低い
ため、さらに、3M社製の「BEF90」を2枚直交配
置して集光性を高めた。半値幅は約±30°であった。The field-of-view enlarging film 1 was attached so that its convex portion 1a faces the TN liquid crystal cell 2 side. Further, the field-of-view enlarging film 1 was installed so that the convex portions 1a were arranged in the horizontal direction of the screen. Therefore, the field of view is enlarged corresponding to about one convex shape or more for one pixel. The display element is a commercially available TFT-LCD TV, 6E-C3
(Made by Sharp) was used. In the commercially available state, only the white diffuser is arranged on the backlight side, and the light collecting property is low. Therefore, two "BEF90" manufactured by 3M were arranged orthogonally to enhance the light collecting property. The full width at half maximum was about ± 30 °.
【0040】この状態で画面を観察したところ次表1の
ような結果が得られた。When the screen was observed in this state, the results shown in Table 1 below were obtained.
【0041】[0041]
【表1】 [Table 1]
【0042】視野拡大フィルムを実装しない従来品に比
べ、透過率は低下しているが、実使用には支障はない。
視野角については従来品に比べ著しく向上し、液晶ディ
スプレーをほとんど真下からみても階調反転(色が逆転
する現象)は起こらず、良好な画質が得られた。また、
正面からみたときの色ズレ等も起こらなかった。視野拡
大フィルムを使用したことで、表示素子の視野角を著し
く向上させることができた。The transmittance is lower than that of the conventional product in which the field-of-view magnifying film is not mounted, but there is no problem in actual use.
The viewing angle was remarkably improved as compared with the conventional product, and even when the liquid crystal display was viewed from directly below, gradation inversion (the phenomenon of color inversion) did not occur, and good image quality was obtained. Also,
There was no color shift when viewed from the front. By using the field-of-view magnifying film, the viewing angle of the display device could be significantly improved.
【0043】また、視野拡大フィルム1をTFT−LC
Dの観察者側の偏光板3のTN液晶セル2側(内側)に
取付けたので、対擦傷性や無反射処理等の表面処理が必
要なくなり、コストを低下することができると共に、信
頼性を向上することができる。さらに、文字が二重にみ
える等の文字ボケを防止することができる。また、視野
拡大フィルム1の面内方向の光の複屈折位相差を10n
m以下にすることにより、光学的な歪みを防止すること
ができ、液晶ディスプレーへの視野拡大フィルム1の搭
載が容易になる。Further, the field-of-view expansion film 1 is used as a TFT-LC.
Since it is attached to the TN liquid crystal cell 2 side (inner side) of the polarizing plate 3 on the observer side of D, surface treatment such as scratch resistance and antireflection treatment is not required, and the cost can be reduced and the reliability can be improved. Can be improved. Further, it is possible to prevent a character from being blurred such that the character appears double. In addition, the birefringence phase difference of light in the in-plane direction of the field-of-view magnifying film 1 is set to 10n.
When the thickness is m or less, optical distortion can be prevented, and the view expanding film 1 can be easily mounted on the liquid crystal display.
【0044】〔実施例2〕図4は本発明の第2実施例で
ある視野拡大フィルムの断面図である。実施例1と同様
に、ポリカーボネート樹脂上に、紫外線硬化樹脂を塗布
し、実施例1と同一の方法で露光した。次に、現像時間
のみを1分に短縮して現像し、20秒間再露光して形状
を固定した。[Embodiment 2] FIG. 4 is a cross-sectional view of a visual field widening film which is a second embodiment of the present invention. As in Example 1, an ultraviolet curable resin was applied on a polycarbonate resin and exposed in the same manner as in Example 1. Then, only the developing time was shortened to 1 minute for development, and re-exposure was performed for 20 seconds to fix the shape.
【0045】現像後の形状は、図4に示すように、30
μmの平面部aを介して、断面形状において、上面平坦
部bが20μm、斜面曲線部cが25μm、溝深さdが
20μmの台形形状の凸状部5aを配列した視野拡大フ
ィルム5が得られた。この視野拡大フィルム5を実施例
1と同様に、TFT−LCDテレビに実装して特性を評
価したところ、次表2のようになった。The shape after development is 30 as shown in FIG.
A field-enlarging film 5 having a trapezoidal convex portion 5a having an upper surface flat portion b of 20 μm, a sloped curved portion c of 25 μm, and a groove depth d of 20 μm is obtained in a sectional shape through a flat portion a of μm. Was given. As in Example 1, the field-of-view magnifying film 5 was mounted on a TFT-LCD TV and evaluated for characteristics. The results are shown in Table 2 below.
【0046】[0046]
【表2】 [Table 2]
【0047】実施例1に比べ視野角の拡大は少ないもの
の、正面における透過率は60%まで向上し、従来品と
並べて比較しても目視の上からは顕著な差は感じられな
いほどの透過率を得ている。視野角が60°であるが、
用途に応じて使用すれば全く問題ないと考える。 〔実施例3〕図5は本発明の第3実施例である視野拡大
フィルムの断面図である。Although the viewing angle was less widened than in Example 1, the transmittance in the front was improved to 60%, and the transmission was such that no noticeable difference was visually perceived when compared side by side with the conventional product. Is getting the rate. The viewing angle is 60 °,
I think that there is no problem if it is used according to the application. [Embodiment 3] FIG. 5 is a cross-sectional view of a visual field widening film which is a third embodiment of the present invention.
【0048】視野拡大フィルム7を、厚さ100μmの
ポリカーボネートフィルムの金型によるプレス成形によ
り得た。視野拡大フィルム7は、断面形状で、凸状部7
aの曲率半径R1 が10μm、凸状部7aと平面部の間
の曲率半径R2 が7μmの曲線を有し、ピッチpが33
μmである。また、視野拡大フィルム7のプレス成形に
用いられる金型は、断面形状で、曲線部の曲率半径が1
0μm、曲線部と直線部の間の曲率半径が7μmの曲線
を有し、ピッチが33μmであり、金型の材質はアルミ
で、面積230mm×175mm、厚さは20mmであ
る。プレス成形には油圧式プレス機を使用し、プレス条
件は、温度220℃、圧力20kgf/cm2 である。The field-of-view expanding film 7 was obtained by press molding a 100 μm thick polycarbonate film with a mold. The field-of-view magnifying film 7 has a cross-sectional shape and a convex portion 7
a has a radius of curvature R 1 of 10 μm, a radius of curvature R 2 between the convex portion 7 a and the plane portion of 7 μm, and a pitch p of 33
μm. The mold used for press-molding the field-of-view magnifying film 7 has a cross-sectional shape and a curvature radius of the curved portion is 1
It has a curve of 0 μm, a radius of curvature between the curved portion and the straight portion of 7 μm, a pitch of 33 μm, a material of the mold is aluminum, an area of 230 mm × 175 mm, and a thickness of 20 mm. A hydraulic press machine is used for press forming, and the press conditions are a temperature of 220 ° C. and a pressure of 20 kgf / cm 2 .
【0049】また、視野拡大フィルム7の成形は前工程
として、150℃で10分間加熱して残留応力を除去し
た。また、高温下で成形後アニールを行なったので、成
形時の応力緩和とアニールで残留応力は低下し、分布も
均一な、面内方向の複屈折位相差が5nm以下、厚さ方
向の複屈折位相差が3nm以下の成形品を得た。この視
野拡大フィルム7を実施例1と同様に、TFT−LCD
テレビに実装して特性を評価したところ、実装前に上下
の視野角が20〜30°であるのに対して、装着後は5
0〜60°に広がり、画像も鮮明であり、文字バケもな
かった。As a pre-process for forming the field-of-view magnifying film 7, the residual stress was removed by heating at 150 ° C. for 10 minutes. Also, since annealing was performed after molding at a high temperature, the stress relaxation during molding and the residual stress decreased due to annealing, and the distribution was uniform. The birefringence retardation in the in-plane direction was 5 nm or less, and the birefringence in the thickness direction. A molded product having a phase difference of 3 nm or less was obtained. This field-of-view magnifying film 7 was used in the same way as in Example 1 for TFT-LCD
When mounted on a TV and evaluated for characteristics, the vertical viewing angle is 20 to 30 ° before mounting, but it is 5 after mounting.
It spread from 0 to 60 °, the image was clear, and there was no character blurring.
【0050】〔比較例〕図6は比較例としての視野拡大
フィルムの断面図、図7は比較例としての視野拡大フィ
ルムの平面図である。アクリル樹脂上に紫外線硬化樹脂
が塗布され、ピッチpが100μmで、断面形状が1/
2円弧の凸レンズ6aが連続して成型されたアクリル製
マイクロレンズアレイフィルム6を、前述した実施例と
同一のLCDに実装して特性を測定したところ以下の表
3のようになった。[Comparative Example] FIG. 6 is a sectional view of a visual field expanding film as a comparative example, and FIG. 7 is a plan view of a visual field expanding film as a comparative example. UV curable resin is applied on acrylic resin, pitch p is 100 μm, and cross-sectional shape is 1 /
The acrylic microlens array film 6 in which the convex lenses 6a having two arcs are continuously molded is mounted on the same LCD as in the above-mentioned embodiment, and the characteristics are measured. The results are shown in Table 3 below.
【0051】[0051]
【表3】 [Table 3]
【0052】全方向に光が拡大されるため、正面透過率
が著しく低下している。表示素子としては薄暗く非常に
見にくい。コントラストも低下している。斜め方向のみ
から見るには支障はない。また、残留応力による複屈折
現象が起きるため、映像を動画で表示した場合、フィル
ムがないときに比べ、色合いがおかしく、不自然な感じ
になった。テレビ等の表示素子には不適であった。Since the light is expanded in all directions, the front transmittance is remarkably reduced. It is dim and very difficult to see as a display element. The contrast is also reduced. There is no hindrance when viewed from the diagonal direction only. In addition, since a birefringence phenomenon occurs due to residual stress, when an image is displayed as a moving image, the tint is strange and unnatural compared to when there is no film. It was not suitable for display elements such as televisions.
【0053】以上、本発明者によってなされた発明を、
実施例に基づき具体的に説明したが、本発明は、前記実
施例に限定されるものではなく、その要旨を逸脱しない
範囲で、種々変更可能であることは、言うまでもない。As described above, the invention made by the present inventor is:
Although the present invention has been specifically described based on the embodiments, it goes without saying that the present invention is not limited to the embodiments and various modifications can be made without departing from the scope of the invention.
【0054】[0054]
【発明の効果】本願によって開示される発明のうち、代
表的なものによって得られる効果を簡単に説明すれば、
以下のとおりである。本発明の視野拡大フィルムによれ
ば、基材上に凸状部(または凹状部)と平面部とを交互
に形成したので、平面部では光線が曲がることなく、正
面に透過し、凸状部では視野拡大効果を有するため、液
晶ディスプレーの画面正面の画像が薄暗くなることな
く、画面上下方向の視野が拡大し、画面を斜め方向から
見たときの階調反転を防止することができる。The effects obtained by the typical ones of the inventions disclosed in this application will be briefly described as follows.
It is as follows. According to the visual field expansion film of the present invention, since the convex portions (or concave portions) and the flat surface portion are alternately formed on the base material, the light rays are not bent in the flat surface portion and are transmitted to the front surface, and the convex portion is formed. Since it has the effect of expanding the field of view, the field of view in the vertical direction of the screen is expanded without dimming the image in front of the screen of the liquid crystal display, and it is possible to prevent gradation inversion when the screen is viewed from an oblique direction.
【0055】また、本発明の液晶ディスプレーによれ
ば、液晶セルと観察者側偏光板の間に視野拡大フィルム
を、その凸状部が液晶セル側を向くように配置したの
で、画像が鮮明になり、従来の液晶セル製造工程を複雑
にすることなく、広い視野角を得ることができ、高視野
角化に伴い大型化が達成できる。Further, according to the liquid crystal display of the present invention, since the field-enlarging film is arranged between the liquid crystal cell and the observer-side polarizing plate so that the convex portion faces the liquid crystal cell side, the image becomes clear, A wide viewing angle can be obtained without complicating the conventional liquid crystal cell manufacturing process, and a larger size can be achieved along with a higher viewing angle.
【図1】本発明の第1実施例である視野拡大フィルムの
断面図である。FIG. 1 is a cross-sectional view of a visual field widening film that is a first embodiment of the present invention.
【図2】本発明の第1実施例である視野拡大フィルムの
平面図である。FIG. 2 is a plan view of a visual field expanding film that is a first embodiment of the present invention.
【図3】本発明の第1実施例である視野拡大フィルムを
実装した液晶ディスプレーの概略断面図である。FIG. 3 is a schematic cross-sectional view of a liquid crystal display on which the field-of-view magnifying film according to the first embodiment of the present invention is mounted.
【図4】本発明の第2実施例である視野拡大フィルムの
断面図である。FIG. 4 is a cross-sectional view of a visual field widening film that is a second embodiment of the present invention.
【図5】本発明の第3実施例である視野拡大フィルムの
断面図である。FIG. 5 is a cross-sectional view of a visual field widening film that is a third embodiment of the present invention.
【図6】比較例の視野拡大フィルムの断面図である。FIG. 6 is a cross-sectional view of a visual field widening film of a comparative example.
【図7】比較例の視野拡大フィルムの平面図である。FIG. 7 is a plan view of a visual field widening film of a comparative example.
1,5,7 視野拡大フィルム 1a,5a,7a 凸状部 2 TN液晶セル 3 偏光板 4 バックライト 6 マイクロレンズアレイフィルム 6a 凸レンズ 1, 5, 7 Field of view expansion film 1a, 5a, 7a Convex part 2 TN liquid crystal cell 3 Polarizing plate 4 Backlight 6 Micro lens array film 6a Convex lens
Claims (5)
いは凹状部が平面部を介して配列され、光の複屈折位相
差が面内方向および厚さ方向とも60nm以下であるこ
とを特徴とする視野拡大フィルム。1. A plurality of convex portions or concave portions having a curved surface are arranged on a substrate through a flat portion, and the birefringence phase difference of light is 60 nm or less in both the in-plane direction and the thickness direction. A characteristic field-of-view expansion film.
の半径が0〜100μmの円形状に形成され、前記平面
部の長さは、20〜100μmに形成されたことを特徴
とする請求項1記載の視野拡大フィルム。2. The convex portion or the concave portion is formed in a circular shape having a cross-sectional radius of 0 to 100 μm, and the flat portion is formed to have a length of 20 to 100 μm. Item 1. The visual field expansion film according to item 1.
矩形状を呈し、前記矩形の長辺および短辺が20〜10
0μmに形成されたことを特徴とする請求項1記載の視
野拡大フィルム。3. The convex portion or the concave portion has a rectangular cross section, and the long side and the short side of the rectangle are 20 to 10.
The visual field expanding film according to claim 1, wherein the visual field expanding film is formed to have a thickness of 0 μm.
面部との間に曲率半径が10〜300μmの曲線部を有
することを特徴とする請求項2記載の視野拡大フィル
ム。4. The visual field enlarging film according to claim 2, wherein a curved portion having a radius of curvature of 10 to 300 μm is provided between the convex portion or the concave portion and the plane portion.
拡大フィルムが、該視野拡大フィルムの凸状部あるいは
凹状部を液晶セル側に向けて、前記液晶セルの観察面側
に装着されたことを特徴とする液晶ディスプレー。5. The field-of-view magnifying film according to claim 1, 2, 3 or 4 is mounted on the viewing surface side of the liquid crystal cell with the convex or concave part of the field-of-view magnifying film facing the liquid crystal cell side. Liquid crystal display that is characterized.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP7202238A JPH0949925A (en) | 1995-08-08 | 1995-08-08 | Visual field widening film and liquid crystal display using the same |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP7202238A JPH0949925A (en) | 1995-08-08 | 1995-08-08 | Visual field widening film and liquid crystal display using the same |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH0949925A true JPH0949925A (en) | 1997-02-18 |
Family
ID=16454249
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP7202238A Pending JPH0949925A (en) | 1995-08-08 | 1995-08-08 | Visual field widening film and liquid crystal display using the same |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0949925A (en) |
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