JPH07333432A - Optical function element and liquid crystal display device - Google Patents
Optical function element and liquid crystal display deviceInfo
- Publication number
- JPH07333432A JPH07333432A JP12496994A JP12496994A JPH07333432A JP H07333432 A JPH07333432 A JP H07333432A JP 12496994 A JP12496994 A JP 12496994A JP 12496994 A JP12496994 A JP 12496994A JP H07333432 A JPH07333432 A JP H07333432A
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- Japan
- Prior art keywords
- liquid crystal
- polarized light
- layer
- incident
- optical functional
- Prior art date
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- Liquid Crystal (AREA)
- Polarising Elements (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、通常光を効率よく一方
の偏光に変換する光利用効率の高い光機能素子及びそれ
を用いた表示が明るい液晶表示装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical functional element having a high light utilization efficiency for efficiently converting a normal light into one polarized light and a liquid crystal display device using the same which has a bright display.
【０００２】[0002]
【従来の技術】自然光は様々な偏光を含んでおり、その
中から特定の偏光を取り出す偏光素子は、大きく２つに
分類される。一つは、「二色性」吸収により一方の偏光
を吸収するタイプのものであり、アクリル樹脂中にヨウ
素を混ぜ、延伸によって配向させた、いわゆる偏光フィ
ルムがこれに属する。偏光フィルムは比較的安価であ
り、大きなシート状で入手可能である。もう一つは、方
解石のような複屈折性結晶のプリズム２個を主軸が直交
するように貼合わせ、屈折方向に偏光依存を与えたウォ
ラストンプリズムのような偏光プリズム等である。偏光
プリズムは結晶を用いるので、非常に高価である。2. Description of the Related Art Natural light contains various polarized lights, and polarizing elements for extracting a specific polarized light from them are roughly classified into two. One is a type that absorbs one polarized light by "dichroic" absorption, and a so-called polarizing film, in which iodine is mixed in an acrylic resin and oriented by stretching, belongs to this. Polarizing films are relatively inexpensive and are available in large sheets. The other is a polarizing prism such as a Wollaston prism in which two prisms made of a birefringent crystal such as calcite are laminated so that their principal axes are orthogonal to each other, and the polarization direction is given polarization dependence. Since the polarizing prism uses a crystal, it is very expensive.
【０００３】偏光素子を用いる製品として、液晶表示装
置が広く知られている。この液晶表示装置用の偏光素子
として、一般に安価な偏光フィルムが用いられている。
液晶表示装置では、ねじれネマチックモード等の液晶表
示素子を偏光フィルムで挟み、液晶表示素子を光スイッ
チとして機能させ、高いコントラストの表示を得る。し
かし、「二色性」吸収を用いると、一方の偏光が吸収さ
れてしまうので、光の利用効率が１／２以下になってし
まう。そのため、液晶表示装置などに用いた場合、表示
が暗くなり、特に、背後に光源を置かない反射型液晶表
示装置では、印刷物と比べて非常に暗い。A liquid crystal display device is widely known as a product using a polarizing element. An inexpensive polarizing film is generally used as the polarizing element for the liquid crystal display device.
In a liquid crystal display device, a liquid crystal display element of twisted nematic mode or the like is sandwiched between polarizing films, and the liquid crystal display element functions as an optical switch to obtain a high contrast display. However, when the “dichroic” absorption is used, one polarized light is absorbed, so that the light use efficiency is reduced to ½ or less. Therefore, when used in a liquid crystal display device or the like, the display becomes dark, and in particular, in a reflection type liquid crystal display device in which a light source is not placed behind, it is very dark as compared with printed matter.
【０００４】一方、例えば特開平０３−２６１９１０号
公報に示された投射型液晶表示装置では、光利用効率を
高めるため、図８に示すように、ダイクロイックミラー
９０により、光源光の一方の偏光９１を透過させるとと
もに、他方の偏光９２を反射させ、さらに反射した偏光
９２をミラー９３により位相を反転させて再反射させる
という方法が用いられている。また、例えば特開平３−
２７３２号公報に示された複屈折性レンズを用いる方法
の場合、図９に示すように、延伸したポリイミドからな
る複屈折レンズ１０２とアクリル樹脂１０３を接合さ
せ、一方の偏光１０５だけを集光し、他方の偏光１０４
は直進させる。集光部１０７に位相を反転させるＴＮ液
晶を配置し、一方の偏光１０５を他方の偏光１０４に変
換する。その結果、大部分の入射光は他方の偏光１０４
に揃えられる。但し、複屈折レンズ１０２の材料である
ポリイミドとアクリル樹脂１０３との屈折率差（複屈折
率に等しい）がせいぜい０．３程度であるため、複屈折
レンズ１０２の焦点距離と直径の比（Ｆ値）は大きな値
になる。従って、入射角がわずかにずれても集光位置が
大きく横に移動するため、入射角は厳密に守られなけれ
ばならない。On the other hand, in the projection type liquid crystal display device disclosed in, for example, Japanese Patent Application Laid-Open No. 03-261910, in order to improve the light utilization efficiency, as shown in FIG. Is transmitted, while the other polarized light 92 is reflected, and the reflected polarized light 92 is inverted in phase by a mirror 93 and re-reflected. In addition, for example, Japanese Unexamined Patent Publication No.
In the case of the method using the birefringent lens disclosed in Japanese Patent No. 2732, as shown in FIG. 9, the birefringent lens 102 made of stretched polyimide and the acrylic resin 103 are bonded to collect only one polarized light 105. , The other polarization 104
Let go straight. A TN liquid crystal for inverting the phase is arranged in the light collecting unit 107, and one polarized light 105 is converted into the other polarized light 104. As a result, most of the incident light will have the other polarization 104.
Are aligned with. However, since the difference in refractive index (equal to the birefringence) between the polyimide, which is the material of the birefringence lens 102, and the acrylic resin 103 is about 0.3 at most, the ratio of the focal length to the diameter of the birefringence lens 102 (F Value) is a large value. Therefore, even if the incident angle is slightly deviated, the converging position largely moves laterally, and therefore the incident angle must be strictly protected.
【０００５】[0005]
【発明が解決しようとする課題】以上のように、液晶表
示装置の偏光素子として、「二色性」吸収を利用した偏
光フィルムを用いた場合、一方の偏光が吸収され光の利
用効率が１／２以下になるため、表示が暗くなり、特
に、背後に光源を置かない反射型液晶表示装置では、印
刷物と比べて非常に暗くなるという問題点を有してい
た。一方、特開平０３−２６１９１０号公報や特開平３
−２７３２号公報に示された従来例では、光利用効率が
高いため、表示を明るくすることは可能であるが、ダイ
クロイックミラー９０等の偏光特性にきわめて強く方向
依存する。また、特開平３−２７３２号公報に複屈折レ
ンズ１０２を用いた従来例では、入射方向がわずかにず
れるだけで、位相反転部１０７に集光されなくなる。従
って、何れの従来例の場合も、入射光の経路が厳密に決
まっている投射型液晶表示装置等に用途が限定され、反
射型液晶表示装置等に用いることは事実上不可能である
という問題点を有していた。本発明は、以上のような問
題点を解決するためになされたものであり、光利用効率
が高く、偏光特性等への依存性の低い光機能素子及びそ
れを用いた液晶表示装置を提供することを目的としてい
る。As described above, when a polarizing film utilizing "dichroic" absorption is used as a polarizing element of a liquid crystal display device, one polarized light is absorbed and the light utilization efficiency is 1 Since it is / 2 or less, the display becomes dark, and in particular, in the reflection type liquid crystal display device in which the light source is not placed behind, there is a problem that it becomes much darker than the printed matter. On the other hand, Japanese Patent Application Laid-Open Nos. 03-261910 and 3
In the conventional example disclosed in Japanese Patent No. 2732, since the light utilization efficiency is high, it is possible to make the display bright, but the polarization characteristics of the dichroic mirror 90 and the like are extremely strongly direction dependent. Further, in the conventional example using the birefringent lens 102 in Japanese Patent Application Laid-Open No. 3-2732, the light is not focused on the phase inversion unit 107 even if the incident direction is slightly shifted. Therefore, in any of the conventional examples, the application is limited to a projection type liquid crystal display device or the like in which the path of incident light is strictly determined, and it is practically impossible to use it in a reflection type liquid crystal display device or the like. Had a point. The present invention has been made to solve the above problems, and provides an optical functional element having high light utilization efficiency and low dependency on polarization characteristics and the like, and a liquid crystal display device using the same. Is intended.
【０００６】[0006]
【課題を解決するための手段】上記目的を達成するた
め、本発明の光機能素子は、入射光に含まれる一方の偏
光と他方の偏光とをそれぞれ異なる方向に出射させる偏
向層と、前記偏向層により異なる方向に出射された前記
一方の偏光及び他方の偏光がそれぞれ異なる入射角度で
入射面に入射し、入射角度により異なる複屈折率及び光
路長を示す複屈折層とを具備し、前記一方の偏光及び他
方の偏光が前記複屈折層を透過する際、前記一方の偏光
又は他方の偏光の位相を回転させ、前記複屈折層から出
射した前記一方の偏光及び他方の偏光の成分の内、前記
一方の偏光又は他方の偏光の成分のいずれかを増加させ
るように構成されている。上記構成において、複屈折層
を出射した一方の偏光及び他方の偏光の位相差が３０度
以下であることが好ましい。また、上記構成において、
複屈折層の複屈折率と光路長との積が、前記複屈折層へ
の入射角が５０度から７５度の範囲では入射光の主波長
の０．５倍であり、前記入射角が３０度以下の範囲では
入射光の主波長０．１倍以下であることが好ましい。ま
た、上記各構成において、複屈折層は、対向する平行な
一対の透明基板と、前記一対の透明基板間に設けられ前
記透明基板の基板面に対し垂直に配向された液晶層を具
備することが好ましい。上記構成において、偏向層は、
入射光に対して複屈折性を示す部分を周期的に配列した
位相型回折格子であることが好ましい。また、上記構成
において、偏向層は、一対の透明基板間に液晶を注入し
たものであって、前記一対の透明基板のそれぞれ対向す
る面上に周期的に異なる配向処理を施し、前記液晶の配
向方向を周期的に変えたものであることが好ましい。ま
た、上記構成において、一対の透明基板のそれぞれ対向
する面上に水平配向膜を形成し、前記水平配向膜上にそ
れぞれ周期的に配列された垂直配向膜を形成することに
より液晶の配向方向を周期的に変えたものであることが
好ましい。また、上記構成において、水平配向膜直下の
液晶の配向方向と、垂直配向膜直下の液晶の配列方向と
のなす角度が３０度から６０度の範囲であることが好ま
しい。または、上記構成において、偏向層は、一対の透
明基板のそれぞれ対向する２つの面の一方に周期的なス
トライプ状の凹凸を設け、他方の対向する面に配向処理
を施し、前記一対の透明基板を貼合わせて形成された空
間部に液晶を注入し、前記透明基板に対し水平に液晶を
配向させた位相型回折格子であることが好ましい。上記
構成において、透明基板の凸部の屈折率と液晶の常光屈
折率とがほぼ等しいことが好ましい。または、上記構成
において、偏向層は、高分子マトリクス中に液晶分子が
基板に対し水平で、かつ一軸方向に配向したものであっ
て、一方の偏光のみ散乱させることが好ましい。また
は、上記構成において、偏向層は、入射光に対し複屈折
性を示すプリズムを周期的に配列したものであることが
好ましい。上記構成において、偏向層は、一対の透明基
板間に液晶を注入したものであって、入射光側の透明基
板の液晶との境界面に周期的な傾斜部を設け、前記傾斜
部近傍の液晶分子を前記傾斜方向に平行に配向させたも
のであることが好ましい。上記構成において、対向する
第１及び第２の透明基板と、前記第１及び第２の透明基
板間に設けられた液晶層を具備し、前記第１の透明基板
の液晶層と接する面上に周期的に繰り返される水平配向
処理部と垂直配向処理部とを形成し、前記水平配向処理
部は、それにより配向される液晶分子の主軸方向が前記
繰り返し方向と斜めに交差するように配向処理され、第
２の透明基板の液晶層と接する面上を垂直配向処理し、
前記第１の透明基板を入射側に配置し、前記第１の透明
基板近傍の液晶が偏向層をなし、前記第２の透明基板近
傍の液晶が複屈折層となることが好ましい。In order to achieve the above object, the optical functional element of the present invention comprises a deflecting layer for emitting one polarized light and the other polarized light included in incident light in different directions, and the deflecting layer. The one polarized light and the other polarized light emitted in different directions by the layers are incident on the incident surface at different incident angles, respectively, and a birefringent layer having a different birefringence and an optical path length depending on the incident angle is provided. When the polarized light and the other polarized light is transmitted through the birefringent layer, the phase of the one polarized light or the other polarized light is rotated, and among the components of the one polarized light and the other polarized light emitted from the birefringent layer, It is configured to increase either the one polarized light component or the other polarized light component. In the above structure, it is preferable that the phase difference between one polarized light and the other polarized light emitted from the birefringent layer is 30 degrees or less. In the above configuration,
The product of the birefringence of the birefringent layer and the optical path length is 0.5 times the dominant wavelength of the incident light in the range of the incident angle to the birefringent layer of 50 degrees to 75 degrees, and the incident angle is 30. It is preferable that the main wavelength of incident light is 0.1 times or less in the range of less than 100 degrees. Further, in each of the above structures, the birefringent layer includes a pair of parallel transparent substrates facing each other and a liquid crystal layer provided between the pair of transparent substrates and oriented perpendicular to the substrate surface of the transparent substrate. Is preferred. In the above structure, the deflection layer is
It is preferable that the phase type diffraction grating has periodically arranged portions exhibiting birefringence with respect to incident light. Further, in the above structure, the deflection layer is one in which liquid crystal is injected between a pair of transparent substrates, and different alignment treatments are periodically performed on respective surfaces of the pair of transparent substrates facing each other to align the liquid crystal. It is preferable that the direction is periodically changed. Further, in the above structure, a horizontal alignment film is formed on the surfaces of the pair of transparent substrates which face each other, and a vertical alignment film is formed on each of the horizontal alignment films so that the alignment direction of the liquid crystal is changed. It is preferably changed periodically. In the above structure, the angle formed by the alignment direction of the liquid crystal directly below the horizontal alignment film and the alignment direction of the liquid crystal immediately below the vertical alignment film is preferably in the range of 30 to 60 degrees. Alternatively, in the above structure, the deflection layer is provided with periodic stripe-shaped irregularities on one of two opposing surfaces of the pair of transparent substrates, and the other opposing surface is subjected to an alignment treatment to form the pair of transparent substrates. It is preferable that the phase type diffraction grating has liquid crystal injected into the space formed by bonding the liquid crystal and the liquid crystal is aligned horizontally with respect to the transparent substrate. In the above structure, it is preferable that the refractive index of the convex portion of the transparent substrate and the ordinary refractive index of the liquid crystal are substantially equal. Alternatively, in the above structure, it is preferable that the polarizing layer has liquid crystal molecules aligned horizontally and uniaxially with respect to the substrate in the polymer matrix, and only one polarized light is scattered. Alternatively, in the above structure, it is preferable that the deflection layer is one in which prisms exhibiting birefringence with respect to incident light are periodically arranged. In the above-mentioned configuration, the deflection layer is one in which liquid crystal is injected between a pair of transparent substrates, and a periodic inclined portion is provided on a boundary surface between the transparent substrate on the incident light side and the liquid crystal, and the liquid crystal near the inclined portion is provided. It is preferable that the molecules are oriented parallel to the tilt direction. In the above structure, the first and second transparent substrates facing each other and a liquid crystal layer provided between the first and second transparent substrates are provided, and the liquid crystal layer is provided on the surface of the first transparent substrate in contact with the liquid crystal layer. Periodically repeating horizontal alignment processing parts and vertical alignment processing parts are formed, and the horizontal alignment processing parts are subjected to alignment processing so that the principal axis directions of the liquid crystal molecules aligned thereby intersect diagonally with the repeating direction. , The surface of the second transparent substrate in contact with the liquid crystal layer is vertically aligned,
It is preferable that the first transparent substrate is arranged on the incident side, the liquid crystal near the first transparent substrate forms a deflecting layer, and the liquid crystal near the second transparent substrate serves as a birefringent layer.
【０００７】一方、本発明の液晶表示装置は、上記各構
成のいずれかを有する光機能素子の出射側に二色性吸収
型の偏光フィルムと液晶表示素子を配置し、前記光機能
素子の出射光の最も強度の強い偏光方向に前記偏光フィ
ルムの偏光軸を合わせるように構成されている。上記構
成において、液晶表示素子の背後に拡散型反射板を配置
することが好ましい。On the other hand, in the liquid crystal display device of the present invention, the dichroic absorption type polarizing film and the liquid crystal display element are arranged on the emission side of the optical function element having any of the above-mentioned respective constitutions, and It is configured so that the polarization axis of the polarizing film is aligned with the polarization direction of the strongest emitted light. In the above structure, it is preferable to dispose a diffusion type reflection plate behind the liquid crystal display element.
【０００８】[0008]
【作用】以上のように構成された本発明の光機能素子及
び液晶表示装置の作用を、図１を参照しつつ説明する。
複屈折性材料、例えば液晶等で作った回折格子やプリズ
ム等（例えば、図１の偏向層１）は、偏光依存性のある
偏向素子（光の進行方向を変える素子）として機能す
る。最も顕著に偏光依存性が現れるのは、複屈折材料
（例えば、ネマチック液晶６）の常光屈折率か異常光屈
折率のいずれかが接合する媒体（透明基板３等）の屈折
率と等しい場合であり、このときは一方の偏光成分（例
えば、偏光８）に対しては偏向素子として機能せず、入
射光（偏光８）は直進する。他方の偏光７に対しては、
偏向層１は偏向素子として機能すると共に、複屈折性を
示す。そのため、偏光７は偏向層１において常光線７ａ
及び異常光線７ｂに別れる。偏向層１を出射するとき、
偏光方向により進行方向が変わり、偏光７（常光線７ａ
及び異常光線７ｂ）と偏光８はそれぞれ複屈折層１０に
異なる入射角で進入する。複屈折層１０の複屈折率をΔ
ｎ、距離をｄ、波長をλとすると、複屈折層１０を透過
するとき、入射光は２π・Δｎｄ／λだけ位相が回転す
る。複屈折層１０はその性質から、光の進行方向によっ
て複屈折率Δｎが異なる場合がある。例えば、ネマチッ
ク液晶を垂直配向させた液晶層１１では、液晶層に垂直
な方向を入射角０として、入射角θの異常光に対する屈
折率ｎe（θ）は次の（数１）であらわされる。The operation of the optical functional element and the liquid crystal display device of the present invention constructed as above will be described with reference to FIG.
A diffraction grating or prism made of a birefringent material such as liquid crystal (for example, the deflection layer 1 in FIG. 1) functions as a polarization-dependent deflection element (an element that changes the traveling direction of light). The most noticeable polarization dependence appears when the birefringent material (eg, nematic liquid crystal 6) has an ordinary refractive index or extraordinary refractive index equal to the refractive index of the medium (transparent substrate 3 or the like) to which the birefringent material is bonded. In this case, one polarization component (for example, polarization 8) does not function as a deflecting element, and the incident light (polarization 8) goes straight. For the other polarization 7,
The deflection layer 1 functions as a deflection element and exhibits birefringence. Therefore, the polarized light 7 is the ordinary ray 7a in the polarizing layer 1.
And the extraordinary ray 7b. When exiting the deflection layer 1,
The traveling direction changes depending on the polarization direction, and the polarized light 7 (ordinary ray 7a
The extraordinary ray 7b) and the polarized light 8 enter the birefringent layer 10 at different incident angles. Let the birefringence of the birefringent layer 10 be Δ
Assuming that n is n, distance is d, and wavelength is λ, the phase of incident light is rotated by 2π · Δnd / λ when transmitted through the birefringent layer 10. Due to the nature of the birefringent layer 10, the birefringence Δn may differ depending on the traveling direction of light. For example, in the liquid crystal layer 11 in which the nematic liquid crystal is vertically aligned, the incident angle 0 is in the direction perpendicular to the liquid crystal layer, and the refractive index n e (θ) for extraordinary light having the incident angle θ is expressed by the following (Equation 1). .
【０００９】[0009]
【数１】 [Equation 1]
【００１０】この場合、常光線に対する屈折率ｎoはｎs
と等しい。但し、ｎp、ｎsはそれぞれ液晶分子の長軸及
び短軸方向の屈折率である。従って、複屈折率Δｎ
（θ）は次の（数２）であらわされる。In this case, the refractive index n o for ordinary rays is n s
Is equal to However, n p and n s are the refractive indices of the liquid crystal molecules in the major axis direction and the minor axis direction, respectively. Therefore, the birefringence Δn
(Θ) is expressed by the following (Equation 2).
【００１１】[0011]
【数２】 [Equation 2]
【００１２】また、（数２）は近似的に（数３）であら
わされる。Further, (Equation 2) is approximately represented by (Equation 3).
【００１３】[0013]
【数３】 [Equation 3]
【００１４】一方、複屈折層１０における光路長はｄ／
ｃｏｓθとなるので、複屈折量は次の（数４）であらわ
される。On the other hand, the optical path length in the birefringent layer 10 is d /
Since it is cos θ, the birefringence amount is represented by the following (Equation 4).
【００１５】[0015]
【数４】 [Equation 4]
【００１６】すなわち、入射角が大きくなると複屈折量
も大きくなるため、偏向層１で分離した１８０度位相差
を有する２つの偏光７及び８が複屈折層を透過する際、
複屈折量の値によっては位相差が小さくなる。そのた
め、複屈折量を適宜選択することにより、２つの偏光７
及び８を１つの偏光８に揃えることができる。That is, since the amount of birefringence increases as the incident angle increases, when two polarized lights 7 and 8 having a 180-degree phase difference separated by the deflecting layer 1 pass through the birefringent layer.
The phase difference becomes small depending on the value of the birefringence amount. Therefore, by appropriately selecting the amount of birefringence, the two polarized light 7
And 8 can be aligned to one polarization 8.
【００１７】一般に、通常の環境で印刷物を見るとき、
紙面が暗くならないよう、天井または斜め上の照明の光
が紙面法線と３０度程度の小さい角度をなすように印刷
物の表面を向けるが、これは反射型の液晶表示装置等で
も同様である。従って、入射光の多くは入射角（紙面法
線となす角）の小さい方向から入射するので、偏光され
ない一方の偏光（例えば、偏光８）は入射角の大きな範
囲での分布量は少ない。ところが、他方の偏光（例え
ば、偏光７）は、偏向層１を透過して屈折され、入射角
の大きな方向にも分布を広げ、複屈折層１０へ入射す
る。回折格子のような周期構造を異方性物質で形成する
場合、異方性物質の主軸を周期構造の方向に対し４５度
をなすように配向させると、回折した偏光の偏光面は垂
直配向液晶分子に対し４５度をなすので、複屈折を受け
やすくなる。複屈折層１０の厚さｄを適当な大きさに設
定し、入射角が６０〜７０度程度の範囲で複屈折量が
０．５になるようにすれば、大きな入射角で複屈折層へ
進入した他方の偏光７は偏光面を回転させて一方の偏光
８の成分が増え、入射角が５０度程度以下の一方の偏光
８はほぼそのままの偏光面を保つ。この結果、複屈折層
１０を出射する光の一方の偏光８の強度は入射偏光より
増大し、他方の偏光７は減少する。Generally, when viewing printed matter in a normal environment,
The surface of the printed matter is directed so that the light of illumination on the ceiling or obliquely makes a small angle of about 30 degrees with the normal to the surface of the paper so that the surface of the paper does not become dark. Therefore, most of the incident light is incident from a direction having a small incident angle (an angle formed with the normal to the paper surface), and one polarized light that is not polarized (for example, polarized light 8) has a small distribution amount in a large incident angle range. However, the other polarized light (for example, the polarized light 7) is transmitted through the deflecting layer 1 and is refracted, the distribution is widened even in the direction of the large incident angle, and the polarized light is incident on the birefringent layer 10. When a periodic structure such as a diffraction grating is formed of an anisotropic material, if the principal axis of the anisotropic material is oriented at 45 degrees with respect to the direction of the periodic structure, the plane of polarization of the diffracted polarized light is a vertically aligned liquid crystal. Since it forms 45 degrees with respect to the molecule, it is likely to be birefringent. By setting the thickness d of the birefringent layer 10 to an appropriate size and setting the birefringence amount to 0.5 in the incident angle range of about 60 to 70 degrees, the birefringent layer is formed at a large incident angle. The polarization plane of the other polarized light 7 that has entered is rotated to increase the component of the one polarized light 8, and the one polarized light 8 having an incident angle of about 50 degrees or less keeps the polarization surface almost unchanged. As a result, the intensity of one polarized light 8 of the light emitted from the birefringent layer 10 is higher than that of the incident polarized light, and the other polarized light 7 is decreased.
【００１８】複屈折層１０の下に、一方の偏光８と平行
に偏光板１３ａを配置し、その下に液晶表示素子１４、
拡散反射板１５を配置することにより、従来のものとほ
ぼ同じコントラストを有し、かつ反射率が５０％以上の
液晶表示装置が得られる。液晶により変調を受け拡散反
射板から戻ってくる画像は、偏光板１３ａ及び１３ｂに
より一方の偏光７’及び８’だけとなるので、再び偏向
層１を通っても偏光されず画像が二重に見えたりするこ
とはない。A polarizing plate 13a is arranged below the birefringent layer 10 in parallel with one polarized light 8, and a liquid crystal display element 14 is provided under the polarizing plate 13a.
By disposing the diffuse reflection plate 15, a liquid crystal display device having substantially the same contrast as the conventional one and a reflectance of 50% or more can be obtained. The image that is modulated by the liquid crystal and returns from the diffuse reflection plate is only one polarized light 7'and 8'by the polarizing plates 13a and 13b. You can't see it.
【００１９】[0019]
（第１の実施例）本発明の光機能素子及び液晶表示装置
の好適な第１の実施例を図１及び図２を参照しつつ説明
する。図１は、本発明の光機能素子及び液晶表示装置の
第１の実施例の構成を示す断面図であり、図２はネマチ
ック液晶層における配向方向を表す平面図である。この
第１の実施例は、偏向層１として複屈折性を示す液晶を
用いた位相型回折格子を用いた例を示している。(First Embodiment) A preferred first embodiment of the optical functional element and the liquid crystal display device of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view showing the configuration of a first embodiment of an optical functional element and a liquid crystal display device of the present invention, and FIG. 2 is a plan view showing the alignment direction in a nematic liquid crystal layer. The first embodiment shows an example in which a phase type diffraction grating using a liquid crystal exhibiting birefringence is used as the deflection layer 1.
【００２０】図１において、偏向層１は、ガラス等で形
成された第１の基板２と第２の基板３との間にネマチッ
ク液晶層６を挟むように構成されている。第１の基板２
の下面及び第２の基板３の上面にはそれぞれ、ポリイミ
ド等を主成分とする水平配向膜４が形成されており、ま
た水平配向膜４の所定の範囲にはシランカプリング剤を
原料とする垂直配向膜５が形成されている。一方、複屈
折層１０は、ガラス等で形成された第２の基板３と第３
の基板９との間にネマチック液晶層１１を挟むように構
成されている。第２の基板３の下面及び第３の基板９の
上面にはそれぞれ、シランカプリング剤を原料とする垂
直配向膜５が形成されている。偏向層１及び複屈折層１
０は本発明の光機能素子を構成する。また、液晶表示素
子１２は、ＴＮ液晶パネル１４を挟むように設けられた
２つの偏光板１３ａ及び１３ｂと、偏光板１３ｂの下方
に設けられた拡散反射板１５とを具備するように構成さ
れ、複屈折層１０の下方に配置されている。偏向層１、
複屈折層１０及び液晶表示素子１２は、本発明の液晶表
示装置を構成する。In FIG. 1, the deflection layer 1 is constructed such that a nematic liquid crystal layer 6 is sandwiched between a first substrate 2 and a second substrate 3 made of glass or the like. First substrate 2
A horizontal alignment film 4 containing polyimide or the like as a main component is formed on each of the lower surface of the substrate and the upper surface of the second substrate 3, and a vertical portion made of a silane coupling agent is used as a raw material in a predetermined range of the horizontal alignment film 4. The alignment film 5 is formed. On the other hand, the birefringent layer 10 includes the second substrate 3 and the third substrate 3 formed of glass or the like.
The nematic liquid crystal layer 11 is sandwiched between the substrate 9 and the substrate 9. A vertical alignment film 5 made of a silane coupling agent as a raw material is formed on each of the lower surface of the second substrate 3 and the upper surface of the third substrate 9. Polarizing layer 1 and birefringent layer 1
0 constitutes the optical functional element of the present invention. The liquid crystal display element 12 is configured to include two polarizing plates 13a and 13b provided so as to sandwich the TN liquid crystal panel 14 and a diffuse reflection plate 15 provided below the polarizing plate 13b. It is arranged below the birefringent layer 10. Deflection layer 1,
The birefringent layer 10 and the liquid crystal display element 12 form the liquid crystal display device of the present invention.
【００２１】次に、偏向層１の製造方法について説明す
る。まず、第１及び第２の基板２及び３の表面にポリイ
ミド等を主成分とする水平配向膜４の材料を塗布し、図
２の楕円の長軸方向２０に平行にラビングした。その
後、フォトリソグラフィーにより、ラビング方向に対し
４５度をなす方向２１に平行なストライプのマスクをレ
ジストで形成した。その上から、シランカプラー等を主
成分とする垂直配向膜５の材料を塗布し、１２０℃で焼
成した後、現像液でレジストを除去した。その結果、水
平配向膜４の上にストライプ状の垂直配向膜５が形成さ
れた。垂直配向膜５のストライプのピッチは３μｍであ
り、幅は１．５μｍである。球形スペーサを用い、第１
及び第２の基板２及び３を水平配向膜４どうしが対向す
るように基板間距離１．３μｍに保ち、シール樹脂で周
辺を固定してパネル化した。このとき、第１及び第２の
基板２及び３の垂直配向膜５の位置がずれないよう位置
を正確に合わせる。そして、ＢＤＨ社製のネマチック液
晶Ｅ−８（屈折率異方性Δｎ＝０．２３、常光屈折率ｎ
O＝１．５２）を第１及び第２の基板２及び３の間に形
成された空間に注入した。その結果、図１及び図２に示
すように、垂直配向膜５がある部分の液晶分子６ｂは垂
直に配向され（図２では円の部分）、水平配向膜４が露
出している部分の液晶分子６ａはストライプパターンと
４５度をなす方向でかつ各基板２及び３に水平になるよ
うに配向された。なお、図１におけるハンマー状の記号
６ａは、液晶分子がハンマーの頭を手前としてハンマー
の柄に平行に並んでいることを示す慣用的な記号であ
る。Next, a method of manufacturing the deflection layer 1 will be described. First, the surface of the first and second substrates 2 and 3 was coated with the material of the horizontal alignment film 4 containing polyimide as a main component and rubbed in parallel with the major axis direction 20 of the ellipse in FIG. Then, by photolithography, a mask of stripes parallel to the direction 21 forming 45 degrees with respect to the rubbing direction was formed of a resist. From there, a material for the vertical alignment film 5 containing a silane coupler or the like as a main component was applied, baked at 120 ° C., and then the resist was removed with a developing solution. As a result, a stripe-shaped vertical alignment film 5 was formed on the horizontal alignment film 4. The stripes of the vertical alignment film 5 have a pitch of 3 μm and a width of 1.5 μm. First using spherical spacers
The second substrates 2 and 3 were kept at a distance between the substrates of 1.3 μm so that the horizontal alignment films 4 face each other, and the periphery was fixed with a sealing resin to form a panel. At this time, the positions of the vertical alignment films 5 on the first and second substrates 2 and 3 are accurately aligned so that they do not shift. Then, a nematic liquid crystal E-8 manufactured by BDH (refractive index anisotropy Δn = 0.23, ordinary light refractive index n
O = 1.52) was injected into the space formed between the first and second substrates 2 and 3. As a result, as shown in FIGS. 1 and 2, the liquid crystal molecules 6b in the portion where the vertical alignment film 5 is present are vertically aligned (circle portion in FIG. 2), and the liquid crystal in the portion where the horizontal alignment film 4 is exposed. The molecules 6a were oriented so as to form a 45 ° angle with the stripe pattern and to be horizontal to the substrates 2 and 3. The hammer-shaped symbol 6a in FIG. 1 is a conventional symbol that indicates that the liquid crystal molecules are aligned parallel to the handle of the hammer with the head of the hammer facing you.
【００２２】以上のようにして形成された偏向層１に対
し、ハロゲンランプの光をコリメートし、基板法線から
４０度の方向から入射させたところ、図２における方向
２０と垂直な偏光８は直進した。また、方向２０に平行
な偏光７の内、輝度において６０％程度の光は、回折に
より方向２１に垂直な面内で偏向した。なお、偏向角は
１次回折光が９度、２次回折光が１７．５度、３次回折
光が２５度であった。When the light of the halogen lamp is collimated and made to enter from the direction of 40 degrees from the substrate normal to the deflection layer 1 formed as described above, the polarized light 8 perpendicular to the direction 20 in FIG. I went straight. Further, out of the polarized light 7 parallel to the direction 20, about 60% of the light in luminance was deflected by diffraction in a plane perpendicular to the direction 21. The deflection angle was 9 degrees for the first-order diffracted light, 17.5 degrees for the second-order diffracted light, and 25 degrees for the third-order diffracted light.
【００２３】複屈折層１０も同様に、表面に垂直配向膜
５が形成された２つの基板３及び９を基板距離１．０μ
ｍに保ち、その間に、複屈折率△ｎが０．１５のネマチ
ック液晶を注入し、垂直配向させて形成し、偏向層１の
第２の基板３の下方（背面）に配置した。なお、偏向層
１の第２の基板２と複屈折層１０の第２の基板２との間
に、界面での反射を防ぐための、ガラスと屈折率が近い
エチレングリコールを充填し、実質的に２つの第２の基
板２を一体化している。Similarly, in the birefringent layer 10, the two substrates 3 and 9 each having the vertical alignment film 5 formed on the surface thereof are separated by a substrate distance of 1.0 μm.
m, while a nematic liquid crystal having a birefringence Δn of 0.15 was injected and vertically aligned to form the polarizing layer 1 below the second substrate 3 (back surface). In addition, between the second substrate 2 of the deflecting layer 1 and the second substrate 2 of the birefringent layer 10, ethylene glycol, which has a refractive index close to that of glass, is filled to prevent reflection at the interface, and substantially. The two second substrates 2 are integrated with each other.
【００２４】次に、前記（数４）に基づいて、垂直配向
液晶素子への入射角と複屈折との関係を数値計算した特
性曲線を図３に示す。図３において、横軸を入射角と
し、特性曲線３０は複屈折量Δｎｄ／λｃｏｓθをあら
わし、また特性曲線３１は複屈折により入射偏光が垂直
な偏光成分に変換される割合をあらわす。入射光の波長
は、視感度の最も高い５５０ｎｍに設定した。特性曲線
３０に着目すると、複屈折量が０．５になるとき入射直
線偏光は垂直な直線偏光に変わるので、変換割合は１．
０になる。特性曲線３１に着目すると、入射角が４０度
以下の範囲では、偏光変換される割合は１５％以下であ
るが、入射角が５０度から７０度の範囲では、平均７０
％程度は偏光変換される。ハロゲンランプの平行ビーム
を基板法線から４０度の方向から入射させて測定したと
ころ、方向２０に垂直な偏光８は、１０％程度しか偏光
状態が変わらなかった。一方、方向２０に平行な偏光７
の内、１次回折光は約３０％、２次回折光は６０％、３
次回折光は９０％が垂直成分に変換された。Next, FIG. 3 shows a characteristic curve in which the relationship between the incident angle to the vertically aligned liquid crystal element and the birefringence is numerically calculated based on the above (Equation 4). In FIG. 3, the horizontal axis is the incident angle, the characteristic curve 30 represents the birefringence amount Δnd / λ cos θ, and the characteristic curve 31 represents the ratio of the incident polarized light converted into the vertical polarization component due to the birefringence. The wavelength of the incident light was set to 550 nm, which has the highest visibility. Focusing on the characteristic curve 30, the incident linearly polarized light changes to vertical linearly polarized light when the birefringence amount becomes 0.5, so that the conversion ratio is 1.
It becomes 0. Focusing on the characteristic curve 31, the ratio of polarization conversion is 15% or less in the range of the incident angle of 40 degrees or less, but the average is 70% in the range of the incident angle of 50 degrees to 70 degrees.
About%, the polarization is converted. When a parallel beam of a halogen lamp was incident from a direction of 40 degrees from the substrate normal and measured, polarization 8 perpendicular to the direction 20 changed its polarization state by only about 10%. On the other hand, polarized light 7 parallel to the direction 20
Of the above, the first-order diffracted light is about 30%, the second-order diffracted light is 60%, 3
90% of the secondary diffracted light was converted to the vertical component.
【００２５】偏向層１及び複屈折層１０で構成される光
機能素子の下に、前記液晶表示素子１２を配置して液晶
表示装置を構成し、屋内の蛍光灯照明下で液晶表示装置
の表示パネルの正面から２度測光の輝度計を用いて表示
特性を測定した。但し、液晶表示素子１２の偏光板１３
ａ及び１３ｂの偏光軸は、偏向層１の液晶６の配向方向
と平行にした。偏光変換された入射角の大きな偏光７
は、偏光板１３ａ及び１３ｂを透過したあと、拡散反射
板１５で拡散反射され、表示パネル正面に近い方向へも
戻る。その結果、偏向層１と複屈折層１０とで構成され
た第１の実施例の光機能素子を付加した液晶表示装置
は、光機能素子を付加しない従来の液晶表示装置と比較
して、約２０％輝度が向上し、コントラストは従来と変
わらないことが確認された。A liquid crystal display device is constructed by disposing the liquid crystal display device 12 under the optical functional device composed of the deflecting layer 1 and the birefringent layer 10, and the liquid crystal display device displays under indoor fluorescent lamp illumination. Display characteristics were measured from the front of the panel using a luminance meter that measures light twice. However, the polarizing plate 13 of the liquid crystal display element 12
The polarization axes of a and 13b are parallel to the alignment direction of the liquid crystal 6 of the deflection layer 1. Polarized polarized light with a large incident angle 7
After being transmitted through the polarizing plates 13a and 13b, is diffusely reflected by the diffuse reflection plate 15 and returns to the direction close to the front surface of the display panel. As a result, the liquid crystal display device to which the optical functional element of the first embodiment, which is composed of the deflection layer 1 and the birefringent layer 10, is added, is about the same as the conventional liquid crystal display device to which the optical functional element is not added. It was confirmed that the brightness was improved by 20% and the contrast was not different from the conventional one.
【００２６】なお、光利用効率を高めるために、複屈折
層１０の複屈折量（複屈折率×距離）は、照明の仕方に
もよるが、入射自然光の分布が多い入射角では小さく、
屈折光が分布する入射角では波長の０．５倍に近くする
ことが望ましい。従って、偏向層１に入射した直交する
２つの偏光７及び８の屈折角の差は大きな方がよく、分
離した偏光が複屈折層１０を通った結果、２つの偏光の
位相差が３０度以下になれば入射光のうち９０％は１つ
の偏光へ変換される。投射型表示装置に用いる場合のよ
うに入射角度が限定される場合には、その入射角の入射
光に対して位相差が３０度以下になるよう複屈折量を設
定すればよい。入射光が入射角に依存して分布がある場
合は、その強度分布と偏向層の屈折角差とに応じて、最
も偏光変換効率が上がる入射角に対して位相差が小さく
なるよう設定すればよい。例えば、偏向層１及び複屈折
層１０を反射型液晶表示素子と組合わせる場合、入射角
３０度以下の範囲では複屈折率を０．１以下（偏光変換
率が約１０％）とし、屈折光が分布する５０度から７５
度の範囲では、複屈折率が０．５となるよう設定するの
がよい。このときの複屈折率の波長は、入射光線の主波
長、すなわち、自然光ならば視感度の高い緑光に、また
カラーフィルターを設けたりする場合はその色の波長に
設定する。The birefringence amount (birefringence × distance) of the birefringent layer 10 in order to improve the light utilization efficiency is small at an incident angle where the distribution of incident natural light is large, although it depends on the way of illumination.
It is desirable that the incident angle at which the refracted light is distributed be close to 0.5 times the wavelength. Therefore, it is better that the difference between the refraction angles of the two orthogonal polarized lights 7 and 8 incident on the polarizing layer 1 is large, and as a result of the separated polarized light passing through the birefringent layer 10, the phase difference between the two polarized lights is 30 degrees or less. Then, 90% of the incident light is converted into one polarized light. When the incident angle is limited as in the case of being used in a projection display device, the birefringence amount may be set so that the phase difference with respect to the incident light of the incident angle is 30 degrees or less. If the incident light has a distribution depending on the incident angle, if the phase difference is set to be smaller with respect to the incident angle at which the polarization conversion efficiency is highest, depending on the intensity distribution and the difference in the refraction angle of the deflecting layer. Good. For example, when the deflection layer 1 and the birefringent layer 10 are combined with a reflective liquid crystal display element, the birefringence index is set to 0.1 or less (polarization conversion rate is about 10%) in the range of an incident angle of 30 degrees or less, and the refraction light is Distributed from 50 degrees to 75 degrees
In the range of degrees, it is preferable to set the birefringence to be 0.5. The wavelength of the birefringence at this time is set to the main wavelength of the incident light beam, that is, the green light having high visibility in the case of natural light, or the wavelength of that color when a color filter is provided.
【００２７】また、垂直配向液晶層１１に斜めに入射す
る光は液晶分子に対して斜めに入射しなければ複屈折を
受けないので、本実施例では最も効率の高い、進行方向
（屈折方向）に対して４５度に偏光依存性の主軸がある
ように偏向層１の配向方向を設定したが、この角度は、
３０度から６０度の範囲内にあれば複屈折を十分受ける
ので、４５度に限られない。Further, the light obliquely incident on the vertically aligned liquid crystal layer 11 does not undergo birefringence unless obliquely incident on the liquid crystal molecules. Therefore, in the present embodiment, the traveling direction (refraction direction) having the highest efficiency is obtained. The orientation direction of the deflecting layer 1 was set so that there was a polarization-dependent main axis at 45 degrees with respect to
If the angle is within the range of 30 degrees to 60 degrees, the birefringence is sufficiently received, and therefore it is not limited to 45 degrees.
【００２８】（第２の実施例）上記第１の実施例と同様
に、偏向層として位相型回折格子を用いた光機能素子及
び液晶表示装置の好適な第２の実施例を、その構成を示
す断面図である図４を参照しつつ説明する。なお、図１
と同一の番号を付した構成要素は同一であるため、その
説明を省略する。図４において、偏向層４０は、第１の
基板４３と、第２の基板４１と、第１の基板４３の下面
及び第２の基板４１の上面にそれぞれ設けられた水平配
向膜４と、一方の基板４１または４３の上に形成された
凹凸パターン４２と、対向する水平配向膜４及び凹凸パ
ターン４２の凹部に注入されたネマチック液晶層６を具
備するように構成されている。第１の基板４１上に形成
された水平配向膜４は、図１に示した第１の実施例と同
様に、紙面に対し４５度方向にラビングしたものであ
る。凹凸パターン４２は、水平配向膜４の上に光重合型
樹脂（アクリル樹脂など）を塗布し、マスク露光するこ
とにより、紙面に対し垂直方向にストライプ状に形成さ
れている。また、第２の基板４３上に形成された水平配
向膜４も、紙面に４５度方向にラビングしたものであ
る。凹凸パターン４２の屈折率（約１．５）は、ネマチ
ック液晶層６の分子６ａの短軸方向の屈折率と等しく、
長軸方向の屈折率とは異なる。そのため、ネマチック液
晶層６の分子６ａの長軸に平行な偏光のみが回折を生
じ、図１に示した第１の実施例と同様に機能する。この
第２の実施例の場合も、偏向層４０と複屈折層１０とで
構成された光機能素子を液晶表示素子１２に付加するこ
とにより、従来のものより光利用効率が向上し、反射型
液晶表示装置をかなり明るくすることが可能となった。(Second Embodiment) Similar to the first embodiment, a preferred second embodiment of an optical functional element and a liquid crystal display device using a phase type diffraction grating as a deflecting layer will be described. This will be described with reference to FIG. 4, which is a sectional view showing. Note that FIG.
Since the constituent elements given the same numbers as are the same, the description thereof will be omitted. In FIG. 4, the deflection layer 40 includes a first substrate 43, a second substrate 41, horizontal alignment films 4 provided on the lower surface of the first substrate 43 and the upper surface of the second substrate 41, respectively. And the nematic liquid crystal layer 6 injected into the concave portions of the horizontal alignment film 4 and the concavo-convex pattern 42 facing each other. The horizontal alignment film 4 formed on the first substrate 41 is rubbed in the direction of 45 degrees with respect to the paper surface, as in the first embodiment shown in FIG. The concavo-convex pattern 42 is formed in a stripe shape in the direction perpendicular to the paper surface by applying a photopolymerizable resin (acrylic resin or the like) on the horizontal alignment film 4 and performing mask exposure. The horizontal alignment film 4 formed on the second substrate 43 is also rubbed in the direction of 45 degrees on the paper surface. The refractive index (about 1.5) of the concavo-convex pattern 42 is equal to the refractive index of the molecules 6a of the nematic liquid crystal layer 6 in the short axis direction,
It is different from the refractive index in the long axis direction. Therefore, only polarized light parallel to the major axis of the molecules 6a of the nematic liquid crystal layer 6 causes diffraction, and functions similarly to the first embodiment shown in FIG. Also in the case of the second embodiment, by adding the optical functional element constituted by the deflection layer 40 and the birefringent layer 10 to the liquid crystal display element 12, the light utilization efficiency is improved as compared with the conventional one, and the reflection type It has become possible to make the liquid crystal display device considerably brighter.
【００２９】（第３の実施例）次に、本発明の光機能素
子及び液晶表示装置の好適な第３の実施例を、その構成
を示す断面図である図５を参照しつつ説明する。第３の
実施例では、偏向層５０を高分子マトリクスに液晶分子
が基板に対して水平で、かつ一軸方向に配向させたもの
を用い、一方の偏光のみを散乱させる例を示している。
図５において、偏向層５０は、厚さ０．１ｍｍのアクリ
ルフィルム５１を基板間隔２０μｍで対向させた空セル
に、高分子分散液晶を注入し、アクリルフィルム５１の
両端を引張ることにより延伸したものである。高分子分
散液晶は、光重合性のアクリルモノマー（２エチルヘキ
シルアクリレート）１２％とオリゴマー８％、重合開始
剤０．５％、ネマチック液晶Ｅ−８を７９．５％を混
合、加熱して相溶させた溶液を注入し、紫外線を照射す
ることにより作成される。延伸により液晶滴５２は楕円
形になり、液晶分子５５は延伸方向に配向する。この結
果、延伸方向に垂直な入射偏光５３に対しては均質な媒
質となるので、光は直進し、延伸方向に平行な偏光５４
は散乱される。散乱された偏光の広がり方は、液晶滴の
粒径や延伸率により異なるが、液晶滴の短軸を１μｍ、
長軸を３μｍ程度とすると、入射光は方向依存性の少な
い前方散乱を示す。(Third Embodiment) Next, a preferred third embodiment of the optical functional element and the liquid crystal display device of the present invention will be described with reference to FIG. 5 which is a sectional view showing the construction thereof. The third embodiment shows an example in which the polarizing layer 50 is a polymer matrix in which liquid crystal molecules are aligned horizontally and uniaxially with respect to the substrate, and only one polarized light is scattered.
In FIG. 5, the deflection layer 50 is obtained by injecting a polymer-dispersed liquid crystal into an empty cell in which acrylic films 51 having a thickness of 0.1 mm are opposed to each other with a substrate interval of 20 μm, and stretching both ends of the acrylic film 51. Is. The polymer dispersed liquid crystal is a mixture of 12% of a photopolymerizable acrylic monomer (2 ethylhexyl acrylate) and 8% of an oligomer, 0.5% of a polymerization initiator, and 79.5% of a nematic liquid crystal E-8, which are heated to be compatible with each other. It is prepared by injecting the prepared solution and irradiating it with ultraviolet rays. The stretching causes the liquid crystal droplets 52 to be elliptical, and the liquid crystal molecules 55 are oriented in the stretching direction. As a result, the incident polarized light 53 perpendicular to the stretching direction becomes a homogeneous medium, so that the light travels straight and the polarized light 54 parallel to the stretching direction.
Is scattered. The way in which the scattered polarized light spreads depends on the particle size of the liquid crystal droplet and the stretching ratio, but the short axis of the liquid crystal droplet is 1 μm,
When the major axis is about 3 μm, the incident light shows forward scattering with little direction dependence.
【００３０】この散乱型の異方性偏向層５０の下方（背
面）に第１の実施例と同じ複屈折層１０を隣接させる
と、散乱する偏光５４の内、延伸方向と４５度の方向を
中心として偏光面が回転する。延伸方向と４５度の方向
の散乱光は、第１の実施例の場合と同様に、複屈折層１
０への入射角が５０度から８０度の範囲の偏光は他方の
偏光成分へ変換される割合が高い。また、第１の実施例
の場合と同様に複屈折層１０の下方に液晶表示素子１２
を偏光板１３ａ及び１３ｂの偏光軸を偏向層５０の延伸
方向と合わせるように配置し、屋内照明下で測定したと
ころ、偏向層５０と複屈折層１０とで構成された第２の
実施例の光機能素子を付加した液晶表示装置の明るさ
は、光機能素子を付加しない従来の液晶表示装置の明る
さよりも約１５％向上していることが確認された。When the same birefringent layer 10 as that of the first embodiment is placed below (on the back side of) the scattering type anisotropic deflecting layer 50, the stretching direction and the direction of 45 degrees out of the polarized light 54 scattered. The plane of polarization rotates about the center. The scattered light in the stretching direction and the direction of 45 degrees is the same as in the case of the first embodiment.
Polarized light whose incident angle to 0 is in the range of 50 degrees to 80 degrees has a high rate of being converted into the other polarization component. Further, as in the case of the first embodiment, the liquid crystal display element 12 is provided below the birefringent layer 10.
Was arranged so that the polarization axes of the polarizing plates 13a and 13b were aligned with the stretching direction of the deflecting layer 50, and the measurement was performed under indoor illumination. As a result, the polarizing layer 50 and the birefringent layer 10 of the second embodiment were formed. It was confirmed that the brightness of the liquid crystal display device to which the optical functional element was added was improved by about 15% as compared with the brightness of the conventional liquid crystal display device to which the optical functional element was not added.
【００３１】（第４の実施例）次に、本発明の光機能素
子及び液晶表示装置の好適な第４の実施例を、その構成
を示す断面図である図６を参照しつつ説明する。第４の
実施例は、偏光層６０として、複屈折性プリズムを用い
た例を示している。図６において、偏向層６０は、平面
基板６１と、三角波板基板６２と、平面基板６１上面及
び三角波板基板６２の下面の設けられた水平配向膜４
と、水平配向膜４間に注入されたネマチック液晶層６と
を具備するように構成されている。三角波板基板６２
は、例えば高さ０．２ｍｍ、ピッチ０．４ｍｍ、頂角が
８０度の三角波状のポリビニルアルコール製である。水
平配向膜４は、例えばポリイミド等を三角波板基板６２
の下面に塗布し、三角波の斜面に平行にラビングするこ
とにより形成される。水平配向膜４が形成された平面基
板６１及び三角波板基板６２は、厚さ２０μｍのポリエ
ステル製フィルムスペーサー（例えば、東レ製ルミラー
フィルム等）を挟み、上記第１の実施例等と同様にシー
ル樹脂を周辺に塗布することにより貼合わせられる。そ
して、平面基板６１と三角波板基板６２との間の空間
に、ネマチック液晶Ｅ−８を注入した。液晶分子６ａは
パネル面真上から見ると、三角波板基板６２の三角波プ
リズムのストライプパターン（尾根の線）に対し４５度
方向に配向している。(Fourth Embodiment) Next, a preferred fourth embodiment of the optical functional element and the liquid crystal display device of the present invention will be described with reference to FIG. 6 which is a sectional view showing the construction thereof. The fourth embodiment shows an example in which a birefringent prism is used as the polarizing layer 60. In FIG. 6, the deflection layer 60 includes a flat substrate 61, a triangular wave plate substrate 62, and a horizontal alignment film 4 provided on the upper surface of the flat substrate 61 and the lower surface of the triangular wave plate substrate 62.
And a nematic liquid crystal layer 6 injected between the horizontal alignment films 4. Triangular wave plate substrate 62
Is made of polyvinyl alcohol having a height of 0.2 mm, a pitch of 0.4 mm, and an apex angle of 80 degrees in a triangular waveform. The horizontal alignment film 4 is made of, for example, polyimide or the like and has a triangular wave plate substrate 62.
It is formed by applying it to the lower surface of and then rubbing parallel to the slope of the triangular wave. The flat substrate 61 and the triangular wave plate substrate 62 on which the horizontal alignment film 4 is formed sandwich a polyester film spacer having a thickness of 20 μm (for example, Toray Lumirror film or the like), and seal resin similar to the first embodiment. Is applied by applying to the periphery. Then, the nematic liquid crystal E-8 was injected into the space between the flat substrate 61 and the triangular wave plate substrate 62. When viewed from directly above the panel surface, the liquid crystal molecules 6a are oriented at 45 degrees with respect to the stripe pattern (ridge line) of the triangular wave prism of the triangular wave plate substrate 62.
【００３２】液晶分子６ａの常光屈折率とポリビニルア
ルコール及びポリイミドの屈折率はほぼ等しいので、液
晶分子６ａの長軸に垂直な偏光６３に対しては、三角波
板基板６２の三角波状面はプリズムとしては機能せず、
入射偏光は直進する。一方、液晶分子６ａの長軸方向の
偏光６４に対しては、三角波板基板６２の三角波状面は
プリズムとして機能さうるため、入射光は屈折する。入
射角が５０度以下では、屈折角は約１０度前後入射角よ
りも増える。このように、偏光６４のみが大きな出射角
で出射していく。Since the ordinary refractive index of the liquid crystal molecules 6a and the refractive index of polyvinyl alcohol and polyimide are substantially equal to each other, for the polarized light 63 perpendicular to the long axis of the liquid crystal molecules 6a, the triangular wave-shaped surface of the triangular wave plate substrate 62 serves as a prism. Does not work,
The incident polarized light goes straight. On the other hand, for the polarized light 64 in the long axis direction of the liquid crystal molecules 6a, the triangular wave-shaped surface of the triangular wave plate substrate 62 can function as a prism, so that the incident light is refracted. When the incident angle is 50 degrees or less, the refraction angle is about 10 degrees more than the incident angle. In this way, only the polarized light 64 is emitted at a large emission angle.
【００３３】この偏向層６０の下方に、屈折率異方性Δ
ｎが０．１５のネマチック液晶層６６を水平配向させた
厚さ１．０μｍの複屈折層６５を、液晶分子６６ａの長
軸が三角波板基板６２の三角波プリズムのストライプパ
ターンに平行（紙面に垂直）になるように配置した。液
晶分子６６ａの長軸方向と基板６１の法線を含む面での
入射角θに対する屈折率異方性△ｎと距離ｄ／ｃｏｓθ
の積は、前記（数３）にθ＝π/2−θを代入することに
より得られ、次の（数５）のようになる。Below the deflection layer 60, the refractive index anisotropy Δ
A 1.0 μm thick birefringent layer 65 in which a nematic liquid crystal layer 66 with n of 0.15 is horizontally aligned has a long axis of the liquid crystal molecules 66 a parallel to the stripe pattern of the triangular wave prism of the triangular wave plate substrate 62 (perpendicular to the paper surface. ). The refractive index anisotropy Δn and the distance d / cos θ with respect to the incident angle θ on the plane including the long axis direction of the liquid crystal molecules 66a and the normal line of the substrate 61.
The product of is obtained by substituting θ = π / 2−θ into (Equation 3), and is expressed by the following (Equation 5).
【００３４】[0034]
【数５】 [Equation 5]
【００３５】（数５）から明らかなように、垂直配向の
場合より入射角依存が小さく、入射角が増大すると複屈
折量は減少する。これに対して、分子短軸と基板法線を
含む面では△ｎは角度によらないので、複屈折量は（ｎ
p−ｎs）ｄ／λｃｏｓθとなり、垂直配向の場合と同様
に、ｃｏｓθに反比例して急激に増加する。従って、三
角波板基板６２の三角波プリズムの斜面で屈折する方向
に、複屈折層６５の液晶分子６６ａの短軸を合わせれ
ば、θが増大する一方の偏光に対しては複屈折量が増
え、他方の偏光へ変換される率が逆の場合より高い。な
お、上記各実施例３と同様に、拡散反射板１５を有する
液晶表示素子１２を、偏光板１５の偏光軸を紙面に対し
４５度となるように設け、偏向層６０と複屈折層６５と
で構成された光機能素子を付加した液晶表示装置を構成
し、これを屋内照明の下で表示させたところ、偏向層６
０と複屈折層６５とで構成された光機能素子を付加しな
い従来の液晶表示装置より明るいことが確認された。As is clear from (Equation 5), the incident angle dependence is smaller than in the case of vertical orientation, and the birefringence amount decreases as the incident angle increases. On the other hand, since Δn does not depend on the angle in the plane including the molecular short axis and the substrate normal, the birefringence amount is (n
p −n s ) d / λ cos θ, which sharply increases in inverse proportion to cos θ as in the case of vertical alignment. Therefore, if the minor axis of the liquid crystal molecules 66a of the birefringent layer 65 is aligned with the direction of refraction on the slope of the triangular wave prism of the triangular wave plate substrate 62, the birefringence amount increases for one polarized light whose θ increases and the other one increases. The conversion rate of polarized light is higher than that of the opposite case. As in the third embodiment, the liquid crystal display element 12 having the diffuse reflection plate 15 is provided such that the polarization axis of the polarizing plate 15 is 45 degrees with respect to the paper surface, and the polarizing layer 60 and the birefringent layer 65 are provided. When a liquid crystal display device including the optical functional element constituted by the above is constructed and displayed under indoor lighting, the deflection layer 6
It was confirmed that the liquid crystal display device was brighter than the conventional liquid crystal display device in which the optical functional element composed of 0 and the birefringent layer 65 was not added.
【００３６】（第５の実施例）本発明の光機能素子及び
液晶表示装置の好適な第５の実施例を、その構成を示す
断面図である図７を参照しつつ説明する。上記第１の実
施例から第４の実施例までは、偏向層と複屈折層とが分
離されていたが、第５の実施例では１つの液晶パネル８
０でこれら偏向層と複屈折層とを兼ねるように構成され
ている。すなわち、図中上側の第１の基板２では、第１
の実施例１と同様に、ラビングされ水平配向膜４の上
に、垂直配向膜５がラビング方向と４５度をなす方向に
ストライプ状に形成されている。ストライプのピッチは
６μｍであり、ストライプの幅は１：１である。図中下
側の第２の基板８２上には垂直配向膜５が形成されてい
る。第１の基板２と第２の基板８２との基板間隔はスペ
ーサーにより４μｍに保持され、第１の基板２と第２の
基板８２との間の空間にネマチック液晶Ｅ−８を注入す
ることにより液晶層８１が形成されている。液晶層８１
において、第１の基板２の近傍は垂直配向膜５のストラ
イプと４５度をなす水平配向と垂直配向の繰り返しによ
る回折格子構造となり、第２の基板８２の近傍は垂直配
向のみとなる。この場合も、水平配向部の液晶分子６ａ
の長軸に平行な偏光７のみが偏光し、液晶分子６ａの長
軸に垂直な偏光８は直進する。第１の基板２の入射面に
対し４０度方向から入射させた平行光線の内、直進した
偏光８は７％程度が他方の偏光に変わり、回折した偏光
７の内、約１５％が逆の偏光に変換される。従って、第
１の実施例と同様に、液晶層８０の下方にＴＮ液晶表示
素子１２を配置することにより光機能素子を付加した液
晶表示装置を構成し、これを屋内照明の下で表示させた
ところ、光機能素子を付加しない従来の液晶表示装置よ
り明るいことが確認された。(Fifth Embodiment) A preferred fifth embodiment of the optical functional element and the liquid crystal display device of the present invention will be described with reference to FIG. 7 which is a sectional view showing the structure thereof. Although the deflecting layer and the birefringent layer are separated from each other in the first to fourth embodiments, one liquid crystal panel 8 is used in the fifth embodiment.
When it is 0, it is configured to serve both as the deflecting layer and the birefringent layer. That is, in the first substrate 2 on the upper side in the drawing, the first
Similar to the first embodiment, the vertical alignment film 5 is formed on the horizontal alignment film 4 which is rubbed in a stripe shape in a direction forming 45 degrees with the rubbing direction. The stripe pitch is 6 μm and the stripe width is 1: 1. The vertical alignment film 5 is formed on the lower second substrate 82 in the figure. The spacer between the first substrate 2 and the second substrate 82 is kept at 4 μm by a spacer, and the nematic liquid crystal E-8 is injected into the space between the first substrate 2 and the second substrate 82. A liquid crystal layer 81 is formed. Liquid crystal layer 81
In the above, in the vicinity of the first substrate 2, a diffraction grating structure is formed by repeating horizontal alignment and vertical alignment forming 45 degrees with the stripe of the vertical alignment film 5, and in the vicinity of the second substrate 82, only the vertical alignment is formed. Also in this case, the liquid crystal molecules 6a in the horizontal alignment portion
The polarized light 7 parallel to the long axis of is polarized, and the polarized light 8 perpendicular to the long axis of the liquid crystal molecule 6a goes straight. Of the parallel rays incident on the incident surface of the first substrate 2 from the direction of 40 degrees, about 7% of the straight polarized light 8 is changed to the other polarized light, and about 15% of the diffracted polarized light 7 is reversed. It is converted to polarized light. Therefore, as in the first embodiment, the TN liquid crystal display element 12 is arranged below the liquid crystal layer 80 to form a liquid crystal display device to which an optical functional element is added, and this is displayed under indoor lighting. However, it has been confirmed that it is brighter than the conventional liquid crystal display device in which the optical functional element is not added.
【００３７】なお、上記各実施例では、反射型液晶表示
素子１２の前に本発明の光機能素子を配置したが、透過
型液晶と照明との間に本発明の光機能素子を設けても同
様の効果を奏する。また、液晶表示素子を用いた投射型
表示装置において、光源と液晶表示素子との間に本発明
の光機能素子を配置しても同様の効果を奏する。さら
に、上記各実施例では偏向層及び複屈折層として液晶を
用いたが、延伸したポリマーや無機の複屈折性を有する
物質を用いた場合でも、同様の効果を奏する。また、上
記各実施例では、一方の偏光は複屈折を受けないよう複
屈折層を設定したが、２つの偏光の複屈折量に差があ
り、位相差が縮まるのであれば、必ずしもこのように構
成する必要はない。In each of the above embodiments, the optical functional element of the present invention is arranged in front of the reflective liquid crystal display element 12, but the optical functional element of the present invention may be provided between the transmissive liquid crystal and the illumination. Has the same effect. In a projection type display device using a liquid crystal display element, the same effect can be obtained even if the optical functional element of the present invention is arranged between the light source and the liquid crystal display element. Furthermore, although liquid crystals are used as the deflecting layer and the birefringent layer in each of the above-described examples, the same effect can be obtained even when a stretched polymer or an inorganic substance having birefringence is used. Further, in each of the above embodiments, the birefringent layer is set so that one polarization does not undergo birefringence, but if there is a difference in the birefringence amount of the two polarizations and the phase difference is reduced, the No need to configure.
【００３８】[0038]
【発明の効果】以上説明したように、本発明の光機能素
子及び液晶表示装置によれば、偏光層により入射光に含
まれる一方の偏光と他方の偏光とをそれぞれ異なる方向
に出射させ、偏向層により異なる方向に出射された一方
の偏光及び他方の偏光がそれぞれ異なる入射角度で複屈
折層の入射面に入射させ、複屈折層が有する入射角度に
より異なる複屈折率及び光路長を示す性質により一方の
偏光及び他方の偏光が複屈折層を透過する際、一方の偏
光又は他方の偏光の位相を回転させ、複屈折層から出射
した一方の偏光及び他方の偏光の成分の内、一方の偏光
又は他方の偏光の成分のいずれかを増加させるように構
成したので、従来、液晶表示素子の偏光板等でカットさ
れていた偏光成分を偏光板を通過させることができ、光
利用性が向上し、液晶表示装置等の表示を明るくするこ
とができる。As described above, according to the optical functional element and the liquid crystal display device of the present invention, one polarization and the other polarization included in the incident light are emitted in different directions by the polarizing layer and are deflected. One polarized light and the other polarized light, which are emitted in different directions by the layers, are incident on the incident surface of the birefringent layer at different incident angles, and the birefringence and the optical path length differ depending on the incident angle of the birefringent layer. When one polarization and the other polarization pass through the birefringent layer, the phase of one polarization or the other polarization is rotated, and one polarization out of the components of one polarization and the other polarization emitted from the birefringence layer. Or, since it is configured to increase one of the other polarized light components, it is possible to pass the polarized light component, which has been conventionally cut by the polarizing plate of the liquid crystal display element or the like, through the polarizing plate, thereby improving light utilization. , It is possible to brighten the display of crystal display device or the like.
【００３９】また、複屈折層を出射した一方の偏光及び
他方の偏光の位相差が３０度以下とすることにより、通
常の環境で印刷物を見る場合とほぼ同様の条件で液晶表
示装置等の表示を明るくすることができる。さらに、複
屈折層の複屈折率と光路長との積が、前記複屈折層への
入射角が５０度から７５度の範囲では入射光の主波長の
０．５倍であり、前記入射角が３０度以下の範囲では入
射光の主波長０．１倍以下とすることにより、上記複屈
折層を出射した一方の偏光及び他方の偏光の位相差が３
０度以下という条件を容易に作り出すことができる。ま
た、複屈折層を、対向する平行な一対の透明基板と、前
記一対の透明基板間に設けられ前記透明基板の基板面に
対し垂直に配向された液晶層を具備するように構成する
ことにより、周知の液晶表示素子製造技術を応用するこ
とができ、複屈折層の製作が容易になる。Further, by setting the phase difference between one polarized light and the other polarized light emitted from the birefringent layer to be 30 degrees or less, a display of a liquid crystal display device or the like can be displayed under almost the same conditions as when viewing a printed matter in a normal environment. Can be brightened. Further, the product of the birefringence of the birefringent layer and the optical path length is 0.5 times the dominant wavelength of the incident light when the incident angle to the birefringent layer is in the range of 50 degrees to 75 degrees. Is 30 degrees or less, the main wavelength of incident light is 0.1 times or less, so that the phase difference between one polarization and the other polarization emitted from the birefringent layer is 3 or less.
A condition of 0 degrees or less can be easily created. In addition, the birefringent layer is configured to include a pair of parallel transparent substrates facing each other and a liquid crystal layer provided between the pair of transparent substrates and oriented perpendicularly to the substrate surface of the transparent substrate. The well-known liquid crystal display element manufacturing technology can be applied, and the birefringent layer can be easily manufactured.
【００４０】また、偏向層を、入射光に対して複屈折性
を示す部分を周期的に配列した位相型回折格子とするこ
とにより偏光層及び光機能素子を偏平にすることがで
き、液晶表示素子等の表面に取り付けてもあまりかさば
らない。また、偏向層を一対の透明基板間に液晶を注入
し、一対の透明基板のそれぞれ対向する面上に周期的に
異なる配向処理を施し、液晶の配向方向を周期的に変え
ることにより、位相型回折格子の製造が容易になる。ま
た、一対の透明基板のそれぞれ対向する面上に水平配向
膜を形成し、水平配向膜上にそれぞれ周期的に配列され
た垂直配向膜を形成することにより、容易に液晶の配向
方向を周期的に変えることができる。また、水平配向膜
直下の液晶の配向方向と、垂直配向膜直下の液晶の配列
方向とのなす角度が３０度から６０度の範囲とすること
により、複屈折を十分受けることができる。Further, the polarizing layer and the optical functional element can be made flat by using the phase-type diffraction grating in which the portions exhibiting the birefringence with respect to the incident light are periodically arranged, as the polarizing layer. It is not so bulky even if it is attached to the surface of the element. In addition, by injecting liquid crystal between the pair of transparent substrates in the deflecting layer and periodically performing different alignment treatments on the surfaces of the pair of transparent substrates facing each other, the alignment direction of the liquid crystal is periodically changed to obtain a phase type The manufacture of the diffraction grating is facilitated. Further, by forming horizontal alignment films on the surfaces of the pair of transparent substrates that face each other and by forming vertical alignment films that are periodically arranged on the horizontal alignment films, the alignment direction of the liquid crystal can be easily changed periodically. Can be changed to Further, when the angle formed by the alignment direction of the liquid crystal just below the horizontal alignment film and the alignment direction of the liquid crystal just below the vertical alignment film is in the range of 30 to 60 degrees, birefringence can be sufficiently received.
【００４１】または、偏向層を一対の透明基板のそれぞ
れ対向する２つの面の一方に周期的なストライプ状の凹
凸を設け、他方の対向する面に配向処理を施し、前記前
記一対の透明基板を張合わせて形成された空間部に液晶
を注入し、前記透明基板に対し水平に液晶を配向させた
位相型回折格子とすることにより、水平配向膜上に垂直
配向膜を形成することなく、上記位相型回折格子とほぼ
同様の回折格子が得られ、製造工程が簡略化させる。ま
た、透明基板の凸部の屈折率と液晶の常光屈折率とをほ
ぼ等しくすることにより、液晶分子の長軸に平行な偏光
のみを回折させることができる。または、偏向層を高分
子マトリクス中に液晶分子が基板に対し水平で、かつ一
軸方向に配向したものとし、一方の偏光のみ散乱させる
ことにより、偏光層の構造が簡単になり、また製作が容
易になる。Alternatively, the deflecting layer is provided with periodic stripe-shaped irregularities on one of the two opposing surfaces of the pair of transparent substrates, and the other opposing surface is subjected to an alignment treatment to form the pair of transparent substrates. By injecting a liquid crystal into the space formed by laminating and forming a phase type diffraction grating in which the liquid crystal is aligned horizontally with respect to the transparent substrate, without forming a vertical alignment film on the horizontal alignment film, A diffraction grating similar to the phase type diffraction grating is obtained, and the manufacturing process is simplified. Further, by making the refractive index of the convex portion of the transparent substrate substantially equal to the ordinary refractive index of the liquid crystal, only polarized light parallel to the long axis of the liquid crystal molecule can be diffracted. Alternatively, the liquid crystal molecules should be oriented horizontally and uniaxially in the polymer matrix in the polymer matrix, and by scattering only one polarized light, the structure of the polarizing layer becomes simple and easy to manufacture. become.
【００４２】または、偏向層を入射光に対し複屈折性を
示すプリズムを周期的に配列したものとすることによ
り、位相型回折格子を用いた場合よりも大きく光の進行
方向を曲げる（屈折角を大きくする）ことができる。ま
た、偏向層を、一対の透明基板間に液晶を注入したもの
であって、入射光側の透明基板の液晶との境界面に周期
的な傾斜部を設け、前記傾斜部近傍の液晶分子を前記傾
斜方向に平行に配向させたものとすることにより、容易
に上記複屈折性プリズムを形成することができる。Alternatively, the deflecting layer is formed by periodically arranging prisms exhibiting birefringence with respect to the incident light, so that the traveling direction of the light is bent more than the case where the phase type diffraction grating is used (refraction angle). Can be increased). In addition, the deflection layer is one in which liquid crystal is injected between a pair of transparent substrates, and a periodic inclined portion is provided on a boundary surface between the incident light side transparent substrate and the liquid crystal, and liquid crystal molecules in the vicinity of the inclined portion are provided. The birefringent prism can be easily formed by orienting it in parallel with the tilt direction.
【００４３】また、対向する第１及び第２の透明基板
と、第１及び第２の透明基板間に設けられた液晶層を具
備し、第１の透明基板の液晶層と接する面上に周期的に
繰り返される水平配向処理部と垂直配向処理部とを形成
し、水平配向処理部は、それにより配向される液晶分子
の主軸方向が繰り返し方向と斜めに交差するように配向
処理され、第２の透明基板の液晶層と接する面上を垂直
配向処理し、第１の透明基板を入射側に配置し、第１の
透明基板近傍の液晶が偏向層をなし、第２の透明基板近
傍の液晶が複屈折層となるように構成することにより、
１つの液晶パネルで光機能素子を構成することができ、
製造工程の簡略化及びコストダウンを図ることができ
る。Further, the first and second transparent substrates facing each other and the liquid crystal layer provided between the first and second transparent substrates are provided, and a periodic pattern is formed on the surface of the first transparent substrate in contact with the liquid crystal layer. A horizontal alignment treatment part and a vertical alignment treatment part which are repeatedly repeated, and the horizontal alignment treatment part is subjected to an alignment treatment such that the principal axis direction of the liquid crystal molecules aligned thereby intersects the repetition direction at an angle. The surface of the transparent substrate in contact with the liquid crystal layer is vertically aligned, the first transparent substrate is arranged on the incident side, and the liquid crystal near the first transparent substrate forms a deflecting layer, and the liquid crystal near the second transparent substrate. By configuring so as to be a birefringent layer,
An optical functional element can be configured with one liquid crystal panel,
The manufacturing process can be simplified and the cost can be reduced.
【００４４】一方、本発明の液晶表示装置は、上記各構
成のいずれかを有する光機能素子の出射側に二色性吸収
型の偏光フィルムと液晶表示素子を配置し、前記光機能
素子の出射光の最も強度の強い偏光方向に前記偏光フィ
ルムの偏光軸を合わせるように構成したので、従来液晶
表示素子の偏光板によりカットされていた光をも偏光板
を透過させることができ、従来のものと比較して表示が
明るくなる。また、液晶表示素子の背後に拡散型反射板
を配置することにより、反射型の液晶表示装置の表示を
明るくすることができる。On the other hand, in the liquid crystal display device of the present invention, the dichroic absorption type polarizing film and the liquid crystal display element are arranged on the emission side of the optical function element having any of the above-mentioned constitutions, and Since the polarization axis of the polarizing film is aligned with the strongest polarization direction of the emitted light, the light that has been cut by the polarizing plate of the liquid crystal display device can be transmitted through the polarizing plate. The display becomes brighter than Further, by disposing the diffusion type reflection plate behind the liquid crystal display element, the display of the reflection type liquid crystal display device can be brightened.
【図１】本発明の光機能素子及び液晶表示装置の第１の
実施例の構成を示す断面図FIG. 1 is a sectional view showing a configuration of a first embodiment of an optical functional element and a liquid crystal display device of the present invention.
【図２】本発明の第１の実施例における液晶の配向方向
を示す平面図FIG. 2 is a plan view showing an alignment direction of liquid crystal in the first embodiment of the present invention.
【図３】本発明の第１の実施例における複屈折層の角度
依存特性図FIG. 3 is an angle dependence characteristic diagram of the birefringent layer in the first embodiment of the present invention.
【図４】本発明の光機能素子及び液晶表示装置の第２の
実施例の構成を示す断面図FIG. 4 is a sectional view showing the configuration of a second embodiment of the optical functional element and the liquid crystal display device of the present invention.
【図５】本発明の光機能素子及び液晶表示装置の第３の
実施例の構成を示す断面図FIG. 5 is a sectional view showing the configuration of a third embodiment of the optical functional element and the liquid crystal display device of the present invention.
【図６】本発明の光機能素子及び液晶表示装置の第４の
実施例の構成を示す断面図FIG. 6 is a sectional view showing the configuration of a fourth embodiment of the optical functional element and the liquid crystal display device of the present invention.
【図７】本発明の光機能素子及び液晶表示装置の第５の
実施例の構成を示す断面図FIG. 7 is a sectional view showing the configuration of a fifth embodiment of the optical functional element and the liquid crystal display device of the present invention.
【図８】従来の投射型表示装置の偏光変換素子の構成を
示す図FIG. 8 is a diagram showing a configuration of a polarization conversion element of a conventional projection display device.
【図９】別の従来の投射型表示装置の偏光変換素子の構
成を示す図FIG. 9 is a diagram showing a configuration of a polarization conversion element of another conventional projection display device.
１ ：偏向層 ２ ：第１の基板 ３ ：第２の基板 ４ ：水平配向膜 ５ ：垂直配向膜 ６ ：液晶層 ６ａ：液晶分子 ６ｂ：液晶分子 ７ ：入射偏光 ８ ：入射偏光 ９ ：第３の基板 １０ ：複屈折層 １１ ：液晶層 １２ ：液晶表示素子 １３ａ：偏光板 １３ｂ：偏光板 １４ ：ＴＮ液晶パネル １５ ：拡散反射板 ４０ ：偏向層 ４１ ：第１の基板 ４２ ：凹凸パターン ４３ ：第２の基板 ５０ ：偏向層 ５１ ：アクリルフィルム ５２ ：液晶滴 ５３ ：入射偏光 ５４ ：入射偏光 ５５ ：液晶分子 ６０ ：偏向層 ６１ ：平面基板 ６２ ：三角波基板 ６３ ：入射偏光 ６４ ：入射偏光 ６５ ：複屈折層 ６６ ：液晶分子 ８０ ：液晶パネル ８１ ：液晶層 ８２ ：第２の基板 1: deflection layer 2: first substrate 3: second substrate 4: horizontal alignment film 5: vertical alignment film 6: liquid crystal layer 6a: liquid crystal molecule 6b: liquid crystal molecule 7: incident polarization 8: incident polarization 9: third Substrate 10: Birefringent layer 11: Liquid crystal layer 12: Liquid crystal display element 13a: Polarizing plate 13b: Polarizing plate 14: TN liquid crystal panel 15: Diffuse reflector 40: Deflection layer 41: First substrate 42: Concavo-convex pattern 43: Second substrate 50: Deflection layer 51: Acrylic film 52: Liquid crystal droplets 53: Incident polarization 54: Incident polarization 55: Liquid crystal molecules 60: Deflection layer 61: Flat substrate 62: Triangular wave substrate 63: Incident polarization 64: Incident polarization 65: Birefringent layer 66: Liquid crystal molecule 80: Liquid crystal panel 81: Liquid crystal layer 82: Second substrate
Claims (16)
光とをそれぞれ異なる方向に出射させる偏向層と、前記
偏向層により異なる方向に出射された前記一方の偏光及
び他方の偏光がそれぞれ異なる入射角度で入射面に入射
し、入射角度により異なる複屈折率及び光路長を示す複
屈折層とを具備し、前記一方の偏光及び他方の偏光が前
記複屈折層を透過する際、前記一方の偏光又は他方の偏
光の位相を回転させ、前記複屈折層から出射した前記一
方の偏光及び他方の偏光の成分の内、前記一方の偏光又
は他方の偏光の成分のいずれかを増加させる光機能素
子。1. A deflection layer that emits one polarized light and another polarized light included in incident light in different directions, and the one polarized light and the other polarized light emitted in different directions by the deflecting layer are different from each other. Incident on the incident surface at an incident angle, comprising a birefringent layer showing a different birefringence and optical path length depending on the incident angle, when the one polarized light and the other polarized light is transmitted through the birefringent layer, one of the one An optical functional element that rotates the phase of polarized light or the other polarized light and increases one of the one polarized light component or the other polarized light component out of the one polarized light component and the other polarized light component emitted from the birefringent layer. .
の偏光の位相差が３０度以下である請求項１記載の光機
能素子。2. The optical functional element according to claim 1, wherein the phase difference between one polarized light and the other polarized light emitted from the birefringent layer is 30 degrees or less.
前記複屈折層への入射角が５０度から７５度の範囲では
入射光の主波長の０．５倍であり、前記入射角が３０度
以下の範囲では入射光の主波長０．１倍以下である請求
項１又は２記載の光機能素子。3. The product of the birefringence of the birefringent layer and the optical path length is:
When the incident angle to the birefringent layer is in the range of 50 to 75 degrees, it is 0.5 times the dominant wavelength of the incident light, and in the range of the incident angle is 30 degrees or less, the dominant wavelength of the incident light is 0.1 times or less. The optical functional element according to claim 1, which is
基板と、前記一対の透明基板間に設けられ前記透明基板
の基板面に対し垂直に配向された液晶層を具備する請求
項１から３のいずれかに記載の光機能素子。4. The birefringent layer comprises a pair of parallel transparent substrates facing each other, and a liquid crystal layer provided between the pair of transparent substrates and oriented perpendicularly to the substrate surface of the transparent substrate. 4. The optical functional device according to any one of 3 to 3.
す部分を周期的に配列した位相型回折格子である請求項
１記載の光機能素子。5. The optical functional element according to claim 1, wherein the deflection layer is a phase type diffraction grating in which portions exhibiting birefringence with respect to incident light are periodically arranged.
入したものであって、前記一対の透明基板のそれぞれ対
向する面上に周期的に異なる配向処理を施し、前記液晶
の配向方向を周期的に変えたものである請求項５記載の
光機能素子。6. The deflection layer is formed by injecting liquid crystal between a pair of transparent substrates, and the alignment directions of the liquid crystal are differently obtained by periodically performing different alignment treatments on respective surfaces of the pair of transparent substrates facing each other. 6. The optical functional device according to claim 5, wherein the optical functional device is obtained by periodically changing.
に水平配向膜を形成し、前記水平配向膜上にそれぞれ周
期的に配列された垂直配向膜を形成することにより液晶
の配向方向を周期的に変えたものである請求項６記載の
光機能素子。7. A liquid crystal alignment direction is formed by forming horizontal alignment films on opposite surfaces of a pair of transparent substrates and forming vertically aligned vertical alignment films on the horizontal alignment films. The optical functional element according to claim 6, which is a functionally changed one.
直配向膜直下の液晶の配列方向とのなす角度が３０度か
ら６０度の範囲である請求項７記載の光機能素子。8. The optical functional device according to claim 7, wherein an angle formed by the alignment direction of the liquid crystal just below the horizontal alignment film and the alignment direction of the liquid crystal just below the vertical alignment film is in the range of 30 to 60 degrees.
向する２つの面の一方に周期的なストライプ状の凹凸を
設け、他方の対向する面に配向処理を施し、前記一対の
透明基板を貼合わせて形成された空間部に液晶を注入
し、前記透明基板に対し水平に液晶を配向させた位相型
回折格子である請求項５記載の光機能素子。9. The deflection layer is provided with periodic stripe-shaped irregularities on one of two opposing surfaces of a pair of transparent substrates, and the other opposing surface is subjected to an alignment treatment to form the pair of transparent substrates. The optical functional element according to claim 5, wherein the optical functional element is a phase type diffraction grating in which liquid crystal is injected into a space formed by pasting and the liquid crystal is aligned horizontally with respect to the transparent substrate.
屈折率とがほぼ等しい請求項９記載の光機能素子。10. The optical functional element according to claim 9, wherein the refractive index of the convex portion of the transparent substrate and the ordinary refractive index of the liquid crystal are substantially equal to each other.
分子が基板に対し水平で、かつ一軸方向に配向したもの
であって、一方の偏光のみ散乱させる請求項１記載の光
機能素子。11. The optical functional element according to claim 1, wherein the deflecting layer is a polymer matrix in which liquid crystal molecules are aligned horizontally and uniaxially with respect to the substrate and scatters only one polarized light.
すプリズムを周期的に配列したものである請求項１記載
の光機能素子。12. The optical functional element according to claim 1, wherein the deflecting layer is formed by periodically arranging prisms exhibiting birefringence with respect to incident light.
注入したものであって、入射光側の透明基板の液晶との
境界面に周期的な傾斜部を設け、前記傾斜部近傍の液晶
分子を前記傾斜方向に平行に配向させたものである請求
項１２記載の光機能素子。13. The deflecting layer is formed by injecting liquid crystal between a pair of transparent substrates, and a periodic inclined portion is provided on a boundary surface between the transparent substrate on the incident light side and the liquid crystal, and a portion near the inclined portion is provided. 13. The optical functional device according to claim 12, wherein liquid crystal molecules are aligned parallel to the tilt direction.
前記第１及び第２の透明基板間に設けられた液晶層を具
備し、前記第１の透明基板の液晶層と接する面上に周期
的に繰り返される水平配向処理部と垂直配向処理部とを
形成し、前記水平配向処理部は、それにより配向される
液晶分子の主軸方向が前記繰り返し方向と斜めに交差す
るように配向処理され、第２の透明基板の液晶層と接す
る面上を垂直配向処理し、前記第１の透明基板を入射側
に配置し、前記第１の透明基板近傍の液晶が偏向層をな
し、前記第２の透明基板近傍の液晶が複屈折層となる請
求項１記載の光機能素子。14. A first and a second transparent substrate facing each other,
A liquid crystal layer provided between the first and second transparent substrates, and a horizontal alignment processing unit and a vertical alignment processing unit which are periodically repeated on a surface of the first transparent substrate in contact with the liquid crystal layer. And the horizontal alignment processing part is aligned so that the main axis direction of the liquid crystal molecules aligned by the horizontal alignment processing part obliquely intersects the repeating direction and the liquid crystal molecules of the second transparent substrate are vertically aligned on the surface in contact with the liquid crystal layer. 2. The liquid crystal near the first transparent substrate serves as a deflecting layer, and the liquid crystal near the second transparent substrate serves as a birefringent layer after being processed and the first transparent substrate is disposed on the incident side. Optical functional element.
光機能素子の出射側に二色性吸収型の偏光フィルムと液
晶表示素子を配置し、前記光機能素子の出射光の最も強
度の強い偏光方向に前記偏光フィルムの偏光軸を合わせ
た液晶表示装置。15. A dichroic absorption type polarizing film and a liquid crystal display element are arranged on the emission side of the optical function element according to claim 1, and the intensity of the emitted light of the optical function element is the highest. A liquid crystal display device in which the polarization axis of the polarizing film is aligned with the strong polarization direction.
配置した請求項１５記載の表示素子。16. The display element according to claim 15, further comprising a diffusion type reflection plate disposed behind the liquid crystal display element.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12496994A JPH07333432A (en) | 1994-06-07 | 1994-06-07 | Optical function element and liquid crystal display device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12496994A JPH07333432A (en) | 1994-06-07 | 1994-06-07 | Optical function element and liquid crystal display device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07333432A true JPH07333432A (en) | 1995-12-22 |
Family
ID=14898708
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP12496994A Pending JPH07333432A (en) | 1994-06-07 | 1994-06-07 | Optical function element and liquid crystal display device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07333432A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100433661B1 (en) * | 1997-12-22 | 2004-07-16 | 비오이 하이디스 테크놀로지 주식회사 | Va mode lcd with high aperture rate for compensating optical anisotropy of lc molecules and fabricating method thereof |
| US7589809B2 (en) | 2002-01-28 | 2009-09-15 | Seiko Epson Corporation | Reflective plate, production method therefor, liquid crystal device, and electronic device |
| JP2012098321A (en) * | 2010-10-29 | 2012-05-24 | Sony Corp | Liquid crystal light control element and imaging apparatus |
| KR101157977B1 (en) * | 2005-11-29 | 2012-06-25 | 엘지디스플레이 주식회사 | Method of Fabricating Liquid Crystal Display Panel |
| JP2012223163A (en) * | 2011-04-22 | 2012-11-15 | Fujifilm Corp | Circularly polarized light lighting device and method for controlling plant growth |
| WO2016194764A1 (en) * | 2015-06-03 | 2016-12-08 | Dic株式会社 | Anisotropic scattering film |
-
1994
- 1994-06-07 JP JP12496994A patent/JPH07333432A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100433661B1 (en) * | 1997-12-22 | 2004-07-16 | 비오이 하이디스 테크놀로지 주식회사 | Va mode lcd with high aperture rate for compensating optical anisotropy of lc molecules and fabricating method thereof |
| US7589809B2 (en) | 2002-01-28 | 2009-09-15 | Seiko Epson Corporation | Reflective plate, production method therefor, liquid crystal device, and electronic device |
| KR101157977B1 (en) * | 2005-11-29 | 2012-06-25 | 엘지디스플레이 주식회사 | Method of Fabricating Liquid Crystal Display Panel |
| JP2012098321A (en) * | 2010-10-29 | 2012-05-24 | Sony Corp | Liquid crystal light control element and imaging apparatus |
| JP2012223163A (en) * | 2011-04-22 | 2012-11-15 | Fujifilm Corp | Circularly polarized light lighting device and method for controlling plant growth |
| WO2016194764A1 (en) * | 2015-06-03 | 2016-12-08 | Dic株式会社 | Anisotropic scattering film |
| JPWO2016194764A1 (en) * | 2015-06-03 | 2017-06-15 | Dic株式会社 | Anisotropic scattering film |
| CN107615106A (en) * | 2015-06-03 | 2018-01-19 | Dic株式会社 | Anisotropic scattering film |
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