JP2968152B2 - Liquid crystal display - Google Patents
Liquid crystal displayInfo
- Publication number
- JP2968152B2 JP2968152B2 JP5185391A JP18539193A JP2968152B2 JP 2968152 B2 JP2968152 B2 JP 2968152B2 JP 5185391 A JP5185391 A JP 5185391A JP 18539193 A JP18539193 A JP 18539193A JP 2968152 B2 JP2968152 B2 JP 2968152B2
- Authority
- JP
- Japan
- Prior art keywords
- liquid crystal
- crystal display
- display device
- substrate
- polarizing plate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Description
【０００１】[0001]
【産業上の利用分野】本発明は色補償板としての位相差
板を設けたスーパーツイスティッドネマティック型液晶
表示装置（以下、「ＳＴＮ−ＬＣＤ」という）に関し、
特に携帯用ワードプロセッサおよびパーソナルコンピュ
ーター等のＯＡ（オフィス・オートメーション）機器の
表示画面に用いられる白黒表示のＳＴＮ−ＬＣＤに関す
るものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a super twisted nematic type liquid crystal display (STN-LCD) provided with a retardation plate as a color compensating plate.
In particular, the present invention relates to a monochrome STN-LCD used for a display screen of an OA (office automation) device such as a portable word processor and a personal computer.
【０００２】[0002]
【従来の技術】図９に従来の液晶表示装置の概略構成を
示す。この液晶表示装置１１はベース基板１４ｂとこれ
に対向配置される対向基板１４ａとの間に液晶層１４ｃ
を挟持した概略構成をとる。各基板１４ａ、１４ｂの外
方にはそれぞれ偏光板１５、１２が設けられ、対向基板
１４ａとこの対向基板１４ａ側に設けられた偏光板１２
との間にはＳＴＮ−ＬＣＤの色付きを解消するための色
補償板として位相差板１３が設けられている。2. Description of the Related Art FIG. 9 shows a schematic configuration of a conventional liquid crystal display device. The liquid crystal display device 11 has a liquid crystal layer 14c between a base substrate 14b and an opposing substrate 14a disposed opposite thereto.
Is adopted. Polarizing plates 15 and 12 are provided outside the substrates 14a and 14b, respectively. The opposing substrate 14a and the polarizing plates 12 provided on the opposing substrate 14a side are provided.
Between them, a phase difference plate 13 is provided as a color compensator for eliminating coloring of the STN-LCD.
【０００３】図１０に、液晶表示装置１１を基板に垂直
な方向から視たときの、上記位相差板の光軸、偏光板の
吸収軸、液晶分子の配向軸の相互の位置関係を示す。FIG. 10 shows the relative positions of the optical axis of the retardation plate, the absorption axis of the polarizing plate, and the orientation axis of the liquid crystal molecules when the liquid crystal display device 11 is viewed from a direction perpendicular to the substrate.
【０００４】α’：対向基板１４ａ側液晶分子の配向軸
１６と対向基板１４ａ側の偏光板１２の吸収軸１８との
なす角。Α ′: Angle formed between the alignment axis 16 of the liquid crystal molecules on the counter substrate 14a side and the absorption axis 18 of the polarizing plate 12 on the counter substrate 14a side.
【０００５】β’：ベース基板１４ｂ側液晶分子の配向
軸１７と対向基板１４ａ側の偏光板１５の吸収軸１９と
のなす角。Β ′: Angle formed between the alignment axis 17 of the liquid crystal molecules on the base substrate 14b side and the absorption axis 19 of the polarizing plate 15 on the counter substrate 14a side.
【０００６】θ’：対向基板１４ａ側液晶分子の配向軸
１６と位相差板１３の光軸２０とのなす角。Θ ′: the angle between the alignment axis 16 of the liquid crystal molecules on the opposite substrate 14 a side and the optical axis 20 of the retardation plate 13.
【０００７】φ’：対向基板１４ａ側液晶分子の配向軸
１６とベース基板１４ｂ側液晶分子の配向軸１７とのな
す角（ツイスト角）。Φ ′: An angle (twist angle) formed between the alignment axis 16 of the liquid crystal molecules on the counter substrate 14a side and the alignment axis 17 of the liquid crystal molecules on the base substrate 14b side.
【０００８】この従来のＳＴＮ−ＬＣＤにおいて、その
液晶層１４ｃのセル厚ｄと屈折率異方性△ｎとの積（ｄ
・△ｎ）は０.８〜０.９μｍの範囲にあり位相差板１３
のレタデーションＲｅは５６５ｎｍである。また対向基
板１４ａ側の液晶分子配向軸１６とこの対向基板１４ａ
側に設けられた偏光板１２とのなす角αは約５０°、ベ
ース基板１４ｂ側の液晶分子配向軸１７とベース基板１
４ｂ側の偏光板１５の吸収軸１９とのなす角βは約１３
０°、対向基板１４ａ側の液晶分子配向軸１６と位相差
板１３の光軸２０とのなす角θは約９０°、対向基板１
４ａ側液晶分子の配向軸１６とベース基板１４ｂ側液晶
分子の配向軸１７とのなす角、すなわち、液晶分子１４
ｃのツイスト角φは２４０°である。In this conventional STN-LCD, the product (d of the cell thickness d of the liquid crystal layer 14c and the refractive index anisotropy Δn) is obtained.
(Δn) is in the range of 0.8 to 0.9 μm and the retarder 13
Has a retardation Re of 565 nm. The liquid crystal molecule alignment axis 16 on the side of the opposing substrate 14a and the opposing substrate 14a
The angle α formed by the polarizing plate 12 provided on the base substrate 14b side is about 50 °, and the liquid crystal molecule alignment axis 17 on the base substrate 14b side is
The angle β between the polarizing plate 15 on the 4b side and the absorption axis 19 is about 13
0 °, the angle θ between the liquid crystal molecule alignment axis 16 on the counter substrate 14a side and the optical axis 20 of the retardation plate 13 is about 90 °,
The angle between the alignment axis 16 of the liquid crystal molecules on the 4a side and the alignment axis 17 of the liquid crystal molecules on the base substrate 14b side, that is, the liquid crystal molecules 14
The twist angle φ of c is 240 °.
【０００９】[0009]
【発明が解決しようとする課題】上記のように色補償板
として位相差板を設けた従来のＳＴＮ−ＬＣＤでは、以
下のような問題を有している。The conventional STN-LCD provided with the phase difference plate as the color compensator as described above has the following problems.
【００１０】すなわち、液晶パネルの持つ位相差の波長
分散性と位相差板の波長分散性とが完全には一致しない
ので、可視領域全域にわたる完全な色補正が得られず、
表示が青く色付き、メリハリのある白黒表示が得られな
い（コントラストが低い）という問題がある。That is, since the wavelength dispersion of the retardation of the liquid crystal panel does not completely match the wavelength dispersion of the retardation plate, complete color correction over the entire visible region cannot be obtained.
There is a problem that the display is colored blue and a sharp black and white display cannot be obtained (low contrast).
【００１１】本発明はこのような課題を解決するために
なされたものであり、ＳＴＮ−ＬＣＤにおいて色付きが
抑制され、かつコントラストの高い白黒表示が実現可能
な液晶表示装置を提供することを目的とする。SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to provide a liquid crystal display device capable of realizing black and white display with high contrast while suppressing coloration in an STN-LCD. I do.
【００１２】[0012]
【課題を解決するための手段】本発明の液晶表示装置
は、対向配置された一対の基板と、該一対の基板に挟持
された液晶と、該一対の基板のそれぞれの外方に設置さ
れた偏光板とを有し、該一対の基板のいずれか一方と、
その外方に設置された該偏光板との間に位相差板が設置
された液晶表示装置において、該位相差板のレタデーシ
ョンＲｅが６５０ｎｍ〜６９０ｎｍの間の値に設定さ
れ、該一対の基板の基板間隔ｄと該液晶の屈折率異方性
Δｎとの積ｄ・Δｎが０.６８〜０.７２の間の値に設定
され、該位相差板が設置された側の基板の液晶分子の配
向軸と該偏光板の吸収軸とのなす角αが−５°〜１５°
の間の値に設定され、該位相差板が設置された側の基板
に対向する基板の液晶分子の配向軸と該偏光板の吸収軸
とのなす角βが４０°〜６０°の間の値に設定され、該
位相差板が設置された側の基板の液晶分子の配向軸と該
位相差板の光軸とのなす角θが６５°〜８５°の間の値
に設定され、該液晶分子のツイスト角φが２４０°〜２
６０°の間の値に設定されている液晶表示装置であっ
て、そのことにより上記目的が達成される。A liquid crystal display device according to the present invention is provided with a pair of substrates opposed to each other, a liquid crystal sandwiched between the pair of substrates, and a liquid crystal display device disposed outside each of the pair of substrates. Having a polarizing plate, and any one of the pair of substrates,
In a liquid crystal display device in which a retardation plate is provided between the polarizer and the polarizer disposed outside thereof, the retardation Re of the retardation plate is set to a value between 650 nm and 690 nm, and The product d · Δn of the substrate interval d and the refractive index anisotropy Δn of the liquid crystal is set to a value between 0.68 and 0.72, and the product of the liquid crystal molecules of the substrate on the side where the retardation plate is installed is set. The angle α between the orientation axis and the absorption axis of the polarizing plate is −5 ° to 15 °
The angle β between the orientation axis of the liquid crystal molecules of the substrate facing the substrate on which the retardation plate is installed and the absorption axis of the polarizing plate is between 40 ° and 60 °. The angle θ between the alignment axis of the liquid crystal molecules of the substrate on the side where the phase difference plate is installed and the optical axis of the phase difference plate is set to a value between 65 ° and 85 °. Twist angle φ of liquid crystal molecules is 240 ° ~ 2
A liquid crystal display device set to a value between 60 °, thereby achieving said object.
【００１３】[0013]
【作用】上記構成によれば、ＳＴＮ−ＬＣＤにおいて液
晶層のセル厚ｄと屈折率異方性△ｎとの積ｄ・△ｎを
０.６８〜０.７２の値に設定し、位相差板のレタデーシ
ョンＲｅを６５０ｎｍ〜６９０ｎｍの値に設定し、対向
基板側の液晶分子配向軸とこの対向基板側に設けられた
偏光板とのなす角αを−５°〜１５°の値に設定し、ベ
ース基板側の液晶分子配向軸とベース基板側の偏光板と
のなす角βを４０°〜６０°の値に設定し、対向基板側
の液晶分子配向軸と位相差板の光軸とのなす角θを６５
°〜８５°の値に設定し、液晶分子のツイスト角φの値
を２４０°〜２６０°の値に設定することによって白黒
表示の色付きが抑制され、高いコントラストが得られ
る。According to the above construction, in the STN-LCD, the product d · Δn of the cell thickness d of the liquid crystal layer and the refractive index anisotropy Δn is set to a value of 0.68 to 0.72, and the phase difference The retardation Re of the plate is set to a value of 650 nm to 690 nm, and the angle α between the liquid crystal molecule alignment axis on the counter substrate side and the polarizing plate provided on the counter substrate side is set to a value of −5 ° to 15 °. The angle β between the liquid crystal molecule alignment axis on the base substrate side and the polarizing plate on the base substrate side is set to a value of 40 ° to 60 °, and the angle β between the liquid crystal molecule alignment axis on the opposite substrate side and the optical axis of the retardation plate is set. Make an angle θ of 65
By setting the twist angle φ of the liquid crystal molecules to a value of 240 ° to 260 °, the coloring of the monochrome display is suppressed, and a high contrast is obtained.
【００１４】[0014]
【実施例】以下、本発明の実施例を説明する。図１に本
発明の実施例に係る液晶表示装置１を示す。この液晶表
示装置１の液晶セル４部は、ベース基板４ｂとこれに対
向配置される対向基板４ａとの間に液晶層４ｃが挟持さ
れている。各種電極、スイッチング素子、配向膜等の要
素は本願の主眼たる要素ではないので図示はしない。Embodiments of the present invention will be described below. FIG. 1 shows a liquid crystal display device 1 according to an embodiment of the present invention. In the liquid crystal cell 4 portion of the liquid crystal display device 1, a liquid crystal layer 4c is sandwiched between a base substrate 4b and an opposing substrate 4a disposed to face the base substrate 4b. Elements such as various electrodes, switching elements, and alignment films are not shown because they are not the main elements of the present invention.
【００１５】ベース基板４ｂの液晶層４ｃに接する側と
は反対側の外方には、偏光板５が設置されている。ま
た、対向基板４ａ側には、対向基板４ａの液晶に接する
側とは反対側の外方にも偏光板２が設置され、この偏光
板２と対向基板４ａとの間には位相差板３が設置されて
いる。A polarizing plate 5 is provided outside the base substrate 4b on the side opposite to the side in contact with the liquid crystal layer 4c. A polarizing plate 2 is also provided on the side of the opposite substrate 4a on the side opposite to the side of the opposite substrate 4a which is in contact with the liquid crystal, and a phase difference plate 3 is provided between the polarizing plate 2 and the opposite substrate 4a. Is installed.
【００１６】図２に、液晶表示装置１を基板に垂直な方
向から視たときの、上記位相差板の光軸、偏光板の吸収
軸、液晶分子の配向軸の相互の位置関係を示す。FIG. 2 shows the positional relationship between the optical axis of the retardation plate, the absorption axis of the polarizing plate, and the orientation axis of the liquid crystal molecules when the liquid crystal display device 1 is viewed from a direction perpendicular to the substrate.
【００１７】α：対向基板４ａ側液晶分子の配向軸６と
対向基板４ａ側の偏光板２の吸収軸８とのなす角。Α: the angle between the alignment axis 6 of the liquid crystal molecules on the counter substrate 4a side and the absorption axis 8 of the polarizing plate 2 on the counter substrate 4a side.
【００１８】β：ベース基板４ｂ側液晶分子の配向軸７
と対向基板４ａ側の偏光板５の吸収軸９とのなす角。Β: alignment axis 7 of liquid crystal molecules on base substrate 4b side
And the absorption axis 9 of the polarizing plate 5 on the counter substrate 4a side.
【００１９】θ：対向基板４ａ側液晶分子の配向軸６と
位相差板３の光軸１０とのなす角。φ：対向基板４ａ側
液晶分子の配向軸６とベース基板４ｂ側液晶分子の配向
軸７とのなす角（ツイスト角）。Θ: the angle between the alignment axis 6 of the liquid crystal molecules on the counter substrate 4a side and the optical axis 10 of the retardation plate 3. φ: Angle (twist angle) formed between the alignment axis 6 of the liquid crystal molecules on the counter substrate 4a side and the alignment axis 7 of the liquid crystal molecules on the base substrate 4b side.
【００２０】本実施例においては、対向基板４ａ側に設
置された偏光板２は単体透過率４２％、偏光度９９.９
９％の偏光板であり、位相差板３は一軸性高分子ポリカ
ーボネイトフィルムで形成されているものを用いた。ベ
ース基板４ｂ側に設置した偏光板５も単体透過率４２
％、偏光度９９.９９％の偏光板である。In this embodiment, the polarizing plate 2 provided on the counter substrate 4a has a single transmittance of 42% and a degree of polarization of 99.9.
The retardation plate 3 was a 9% polarizing plate, and the retardation plate 3 was formed of a uniaxial polymer polycarbonate film. The polarizing plate 5 installed on the base substrate 4b side also has a single transmittance 42.
%, And a polarization degree of 99.99%.
【００２１】さて、本願出願人は、上記の構造の液晶表
示装置について、上記のα、β、θ、φのパラメーター
と、位相差板のレタデーション値Ｒｅ、および液晶層４
ｃのセル厚ｄと液晶の屈折率異方性△ｎとの積ｄ・△ｎ
を含んだ６種のパラメーターについて、これまでの種々
の実験から以下のような設定範囲の液晶表示装置が従来
の設定条件の液晶表示装置よりも、色付きが抑制され、
白黒のコントラストがはっきりした表示が可能である結
果を得た。以下に、本発明の設定範囲を示す。−５°≦
α≦１５°、４０°≦β≦６０°、６５°≦θ≦８５
°、２４０°≦φ≦２６０°、６５０ｎｍ≦Ｒｅ≦６９
０ｎｍ、０.６８≦ｄ・△ｎ≦０.７２次に、この範囲内
から選んだ設定値を有する本発明の実施例に係る液晶表
示装置による表示と、この設定範囲をはずれた設定値の
従来の液晶表示装置による表示の比較結果を示す。The applicant of the present invention has proposed a liquid crystal display device having the above-mentioned structure, the parameters α, β, θ, and φ, the retardation value Re of the retardation plate, and the liquid crystal layer 4.
The product d · セ ル n of the cell thickness d of c and the refractive index anisotropy Δn of the liquid crystal
For the six parameters including, from various experiments so far, the liquid crystal display device in the following setting range is more suppressed in coloring than the liquid crystal display device under the conventional setting conditions,
The result that a display with clear contrast between black and white was possible was obtained. The setting range of the present invention is shown below. -5 ° ≦
α ≦ 15 °, 40 ° ≦ β ≦ 60 °, 65 ° ≦ θ ≦ 85
°, 240 ° ≦ φ ≦ 260 °, 650 nm ≦ Re ≦ 69
0 nm, 0.68 ≦ d · Δn ≦ 0.72 Next, the display by the liquid crystal display device according to the embodiment of the present invention having the set value selected from the range, and the setting value out of the set range. 7 shows a comparison result of display by a conventional liquid crystal display device.
【００２２】（実験例１）まず、上記の本発明による設
定範囲の中から、α＝−５°、β＝６０°、θ＝８５
°、φ＝２６０°、Ｒｅ＝６６０ｎｍ、ｄ・△ｎ＝０.
６９の設定値を有する本実施例の液晶表示装置と上記の
設定範囲をはずれた設定値を有する従来の液晶表示装置
を表示させた。(Experimental Example 1) First, from the setting range according to the present invention, α = −5 °, β = 60 °, θ = 85.
°, φ = 260 °, Re = 660 nm, d · Δn = 0.
The liquid crystal display device of this example having a set value of 69 and the conventional liquid crystal display device having a set value outside the above set range were displayed.
【００２３】図３に、本実施例と従来例の液晶表示装置
について、そのＣＩＥ色度を座標（Ｙ、ｘ、ｙ）で表し
たグラフを示す。このグラフにおいて座標ｘ、ｙは色度
を示し、Ｙは輝度を示す。バックランプの輝度を１００
としてＹは０から１００の値をとる。このグラフの座標
ｘ＝０.３１、ｙ＝０.３１の点をＷｈｉｔｅＰｏｉｎｔ
と呼ぶが、このＷｈｉｔｅＰｏｉｎｔに近く、かつＹの
値が小さいほど表示が黒い。また、ＷｈｉｔｅＰｏｉｎ
ｔに近く、かつＹの値が大きいほど表示が白い。このグ
ラフ中に本実施例に係る液晶表示装置の表示の色度座標
を実線１１で結び、従来例の液晶表示装置の場合の色度
座標を破線１２で結んだものを示す。FIG. 3 is a graph showing the CIE chromaticity of the liquid crystal display devices of the present embodiment and the conventional liquid crystal device in coordinates (Y, x, y). In this graph, coordinates x and y indicate chromaticity, and Y indicates luminance. Backlight brightness of 100
Takes a value from 0 to 100. A point at coordinates x = 0.31 and y = 0.31 in this graph is defined as a WhitePoint.
However, the closer to WhitePoint and the smaller the value of Y, the darker the display is. Also, WhitePoint
The display is whiter as the value is closer to t and the value of Y is larger. In this graph, the chromaticity coordinates of the display of the liquid crystal display device according to the present embodiment are connected by a solid line 11, and the chromaticity coordinates of the conventional liquid crystal display device are connected by a broken line 12.
【００２４】この図から理解されるように、従来例に比
べ、本実施例の場合のｏｆｆ点はＷｈｉｔｅＰｏｉｎｔ
から遠いが、Ｙ値は１／３以下と大幅に小さい。従っ
て、ｏｆｆ点では相対的に本実施例の方が黒く、またＯ
Ｎ点ではほぼ同等である。As can be understood from this figure, the off point in the present embodiment is smaller than that of the conventional example in WhitePoint.
Distant from Y, but the Y value is significantly smaller than 1/3. Therefore, at the off point, the present embodiment is relatively black, and
It is almost the same at N points.
【００２５】すなわち、本発明の実施例に係る液晶表示
装置は従来技術の液晶表示装置より白黒表示が鮮明に実
現できることを示している。That is, it is shown that the liquid crystal display device according to the embodiment of the present invention can realize black and white display more clearly than the liquid crystal display device of the prior art.
【００２６】図４に本実施例および従来例の液晶表示装
置のｏｆｆ時の分光スペクトルを示す。本実施例に係る
液晶表示装置の分光スペクトルを実線で示し、従来例に
係る液晶表示装置の分光スペクトルを破線で示す。FIG. 4 shows the spectral spectra of the liquid crystal display devices of the present embodiment and the conventional example at the time of off. The spectral spectrum of the liquid crystal display device according to the present embodiment is indicated by a solid line, and the spectral spectrum of the liquid crystal display device according to the conventional example is indicated by a broken line.
【００２７】この図から理解されるように、本実施例に
係る液晶表示装置においては従来例の液晶表示装置の場
合と比較して波長が４００ｎｍ〜７００ｎｍの可視光領
域において分光スペクトルが短波長側でやや透過する以
外はほぼフラットな曲線をなし、かつ透過率も低い。こ
の分光スペクトルによる比較によっても本実施例の液晶
表示装置の表示は従来例のそれよりもｏｆｆ時の画素表
示が黒いことが理解される。As can be understood from this figure, in the liquid crystal display device according to the present embodiment, as compared with the liquid crystal display device of the conventional example, the spectral spectrum in the visible light region having a wavelength of 400 nm to 700 nm is shorter. Except for a little transmission, it has a substantially flat curve and low transmittance. It can also be understood from the comparison based on the spectral spectra that the display of the liquid crystal display device of the present embodiment has a darker pixel display when off than that of the conventional example.
【００２８】図５は本実施例および従来例に係る液晶表
示装置を０℃〜４５℃の温度範囲の下で稼働させた場合
の表示コントラストを示すグラフである。実線１５が本
実施例に係る液晶表示装置を用いた場合のコントラスト
を示したものであり、同じ図の中の破線１６は従来例の
液晶表示装置用いて、同じ温度条件下で稼働させた時の
コントラストを示す。この図から理解されるように、本
実施例の液晶表示装置においては従来例の液晶表示装置
に比べ、０℃〜４０℃の温度範囲でコントラストが高
い。特に０℃〜２５℃の範囲ではコントラストが２倍以
上大きく、本実施例の液晶表示装置によれば従来例の液
晶表示装置よりコントラストの高い表示が安定して実現
できる。FIG. 5 is a graph showing the display contrast when the liquid crystal display devices according to the present embodiment and the conventional example are operated in a temperature range of 0 ° C. to 45 ° C. The solid line 15 indicates the contrast when the liquid crystal display device according to the present embodiment is used, and the broken line 16 in the same figure indicates the contrast when the conventional liquid crystal display device is operated under the same temperature conditions. Shows the contrast of As can be understood from this figure, the contrast of the liquid crystal display device of this embodiment is higher in the temperature range of 0 ° C. to 40 ° C. than that of the conventional liquid crystal display device. In particular, in the range of 0 ° C. to 25 ° C., the contrast is more than twice as large, and according to the liquid crystal display device of this embodiment, a display with higher contrast than the conventional liquid crystal display device can be stably realized.
【００２９】（実験例２）次に、本発明の実施例に係る
液晶表示装置として、以下のように設定条件を変え、本
発明の設定範囲からはずれた設定値を有する液晶表示装
置との２例目の比較実験を行った。ベース基板４ｂ側に
設置する偏光板５は単体透過率４２％、偏光度９９.９
９％の偏光板を用い、対向基板４ａ側に設置する偏光板
２は前記のものと同様のものを用い、位相差板３は一軸
性高分子ポリカーボネイトフィルムで、レタデーション
値Ｒｅ＝６９０ｎｍのものを用いた。以下、他のパラメ
ーターの設定値を列挙する。(Experimental example 2) Next, as a liquid crystal display device according to an embodiment of the present invention, a liquid crystal display device having a set value outside the set range of the present invention was changed by changing the setting conditions as follows. Example comparative experiments were performed. The polarizing plate 5 provided on the base substrate 4b side has a single transmittance of 42% and a degree of polarization of 99.9.
A 9% polarizing plate is used. The polarizing plate 2 provided on the counter substrate 4a side is the same as described above. The retardation plate 3 is a uniaxial polymer polycarbonate film having a retardation value Re = 690 nm. Using. The setting values of other parameters are listed below.
【００３０】α＝１５°、β＝６０°、θ＝８５°、φ
＝２４０°、ｄ・△ｎ＝０.６９。Α = 15 °, β = 60 °, θ = 85 °, φ
= 240 °, d · Δn = 0.69.
【００３１】図６に上記の設定値を有する本実施例に係
るＳＴＮ型液晶表示装置と従来例の液晶表示装置を表示
させた場合のＣＩＥ色度を座標（Ｙ、ｘ、ｙ）で表した
グラフを示す。このグラフ中に本実施例の液晶表示装置
による表示の色度座標を実線５７で結び、従来例の液晶
表示装置の場合の色度座標を破線５２で結んだものを示
す。図から理解されるように、この場合も、従来例に比
べ、本実施例の場合のｏｆｆ点はＷｈｉｔｅＰｏｉｎｔ
から遠いが、Ｙ値は大幅に小さい。ｏｆｆ点では相対的
に本実施例の液晶表示装置の表示の方が黒く、ＯＮ点で
はほぼ同等であるので白黒のコントラストが強い。FIG. 6 shows the CIE chromaticity of the STN-type liquid crystal display device according to the present embodiment having the above set values and the conventional liquid crystal display device in coordinates (Y, x, y). The graph is shown. In this graph, the chromaticity coordinates of the display by the liquid crystal display device of this embodiment are connected by a solid line 57, and the chromaticity coordinates of the liquid crystal display device of the conventional example are connected by a broken line 52. As can be understood from the figure, also in this case, the off point in the present embodiment is higher than that of the conventional example in WhitePoint.
Distant, but the Y value is significantly smaller. At the off point, the display of the liquid crystal display device of the present embodiment is relatively black, and at the ON point, the display is almost the same, so that the black and white contrast is strong.
【００３２】図７に本実施例および従来例の液晶表示装
置のｏｆｆ時の分光スペクトルを示す。本実施例に係る
液晶表示装置の分光スペクトルを実線５８で示す。FIG. 7 shows spectral spectra of the liquid crystal display devices of the present embodiment and the conventional example at the time of off. The solid line 58 shows the spectrum of the liquid crystal display device according to this embodiment.
【００３３】この図から理解されるように、本実施例に
係る液晶表示装置においては、この場合も、従来例の液
晶表示装置の場合と比較して波長が４００ｎｍ〜７００
ｎｍの可視光領域において分光スペクトルが短波長側で
やや透過する以外はほぼフラットな曲線をなし、かつ透
過率も低い。この分光スペクトルによる比較によっても
本実施例の液晶表示装置の表示は従来例のそれよりもｏ
ｆｆ時の画素表示が黒いことが理解される。As can be understood from this figure, the liquid crystal display device according to the present embodiment also has a wavelength of 400 nm to 700 nm in comparison with the conventional liquid crystal display device.
In the visible light region of nm, the spectral spectrum has a substantially flat curve except that the spectrum is slightly transmitted on the short wavelength side, and the transmittance is low. The comparison of this spectrum also shows that the display of the liquid crystal display device of the present embodiment is more o.
It is understood that the pixel display at ff is black.
【００３４】図８は本実施例および従来例に係る液晶表
示装置を０℃〜４５℃の温度範囲の下で稼動させた場合
の表示コントラストを示すグラフである。実線５９が本
実施例に係る液晶表示装置を用いた場合のコントラスト
を示したものであり、同じ図の中の破線５６は従来例の
液晶表示装置用いて、同じ温度条件下で液晶表示装置を
稼働させた場合のコントラストを示す。この図から理解
されるように、本実施例の液晶表示装置においては従来
例の液晶表示装置に比べ、０℃〜４０℃の温度範囲でコ
ントラストが高い。特に０℃〜２５℃の範囲ではコント
ラストが２倍以上大きく、本実施例の液晶表示装置によ
れば従来例の液晶表示装置よりコントラストの高い表示
が安定して実現できる。FIG. 8 is a graph showing the display contrast when the liquid crystal display devices according to the present embodiment and the conventional example are operated in a temperature range of 0 ° C. to 45 ° C. A solid line 59 indicates the contrast when the liquid crystal display device according to the present embodiment is used, and a broken line 56 in the same figure indicates a liquid crystal display device using the conventional liquid crystal display device under the same temperature conditions. Shows the contrast when activated. As can be understood from this figure, the contrast of the liquid crystal display device of this embodiment is higher in the temperature range of 0 ° C. to 40 ° C. than that of the conventional liquid crystal display device. In particular, in the range of 0 ° C. to 25 ° C., the contrast is more than twice as large, and according to the liquid crystal display device of this embodiment, a display with higher contrast than the conventional liquid crystal display device can be stably realized.
【００３５】以上、二組の表示データーを示したが、こ
の二組のパラメーターの設定区間内であれば、他の設定
値においても、従来のパラメーター設定の液晶表示装置
よりも鮮明な白黒のコントラストの表示を得ることを確
認した。The two sets of display data have been described above. However, if the other set values are within the set section of the two sets of parameters, the black-and-white contrast is clearer than that of the liquid crystal display device of the conventional parameter setting. I confirmed that I got the display.
【００３６】[0036]
【発明の効果】本発明によれば、位相差板を設けたＳＴ
Ｎ液晶パネルにおいて液晶層のセル厚ｄと屈折率異方性
△ｎとの積ｄ・△ｎ、位相差板のレタデーションＲｅ、
対向基板側の液晶分子配向軸とこの対向基板側に設けら
れた偏光板とのなす角α、ベース基板側の液晶分子配向
軸とベース基板側の偏光板とのなす角β、対向基板側の
液晶分子配向軸と位相差板の光軸とのなす角θおよび液
晶分子のツイスト角φの値を最適化することによってＳ
ＴＮ−ＬＣＤの白黒表示の色付きが抑制され、大きいコ
ントラストが得られる。According to the present invention, an ST having a retardation plate is provided.
In an N liquid crystal panel, the product d · Δn of the cell thickness d of the liquid crystal layer and the refractive index anisotropy Δn, the retardation Re of the retardation plate,
The angle α between the liquid crystal molecule alignment axis on the counter substrate side and the polarizing plate provided on the counter substrate side, the angle β between the liquid crystal molecule alignment axis on the base substrate side and the polarizing plate on the base substrate side, By optimizing the values of the angle θ between the liquid crystal molecule alignment axis and the optical axis of the retardation plate and the twist angle φ of the liquid crystal molecules,
Coloring of the black and white display of the TN-LCD is suppressed, and a large contrast is obtained.
【図１】本発明の実施例に係る液晶表示装置の概略構成
図。FIG. 1 is a schematic configuration diagram of a liquid crystal display device according to an embodiment of the present invention.
【図２】本発明の実施例に係る液晶表示装置の各種光学
的要素の位置関係を示す図。FIG. 2 is a diagram showing a positional relationship between various optical elements of the liquid crystal display device according to the embodiment of the present invention.
【図３】本発明と従来例との表示の比較を示す実験例１
のＣＩＥ色度図。FIG. 3 is an experimental example 1 showing a comparison of display between the present invention and a conventional example.
CIE chromaticity diagram.
【図４】実験例１の本発明および従来例の液晶表示装置
のオフ時の分光スペクトルを示す図。FIG. 4 is a diagram showing a spectrum when the liquid crystal display device of the present invention and a conventional liquid crystal display device of Experimental Example 1 are off.
【図５】実験例１の本実施例に係る液晶表示装置の表示
コントラストと温度の関係を示す図。FIG. 5 is a diagram showing a relationship between display contrast and temperature of the liquid crystal display device according to the first embodiment of Experimental Example 1.
【図６】本発明と従来例との表示の比較を示す実験例２
のＣＩＥ色度図。FIG. 6 is an experimental example 2 showing a comparison of display between the present invention and a conventional example.
CIE chromaticity diagram.
【図７】実験例２の本発明および従来例の液晶表示装置
のオフ時の分光スペクトルを示す図。FIG. 7 is a diagram showing a spectrum when the liquid crystal display device of the present invention and a conventional liquid crystal display device of Experimental Example 2 are off.
【図８】実験例２の本実施例に係る液晶表示装置の表示
コントラストと温度の関係を示す図。FIG. 8 is a diagram showing a relationship between display contrast and temperature of the liquid crystal display device according to the present example of Experimental Example 2.
【図９】従来の液晶表示装置の概略構成図。FIG. 9 is a schematic configuration diagram of a conventional liquid crystal display device.
【図１０】従来の液晶表示装置の各種光学的要素の位置
関係を示す図。FIG. 10 is a diagram showing a positional relationship between various optical elements of a conventional liquid crystal display device.
１ 液晶表示装置 ２ 対向基板側の偏光板 ３ 位相差板 ４ 液晶セル ４ａ 対向基板 ４ｂ ベース基板 ４ｃ 液晶（液晶層、液晶分子） ５ ベース基板側の偏光板 ６ 対向基板側液晶分子配向軸 ７ ベース基板側液晶分子配向軸 ８ 対向基板側偏光板吸収軸 ９ ベース基板側偏光板吸収軸 １０ 位相差板光軸 REFERENCE SIGNS LIST 1 liquid crystal display device 2 polarizing plate on opposing substrate 3 retardation plate 4 liquid crystal cell 4 a opposing substrate 4 b base substrate 4 c liquid crystal (liquid crystal layer, liquid crystal molecules) 5 polarizing plate on base substrate 6 liquid crystal molecule alignment axis on opposing substrate 7 base Substrate side liquid crystal molecule orientation axis 8 Opposite substrate side polarizing plate absorption axis 9 Base substrate side polarizing plate absorption axis 10 Phase difference plate optical axis
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平２−73223（ＪＰ，Ａ) 特開 昭64−23224（ＪＰ，Ａ) 特開 平５−34676（ＪＰ，Ａ) 特開 平５−53103（ＪＰ，Ａ) 特開 平５−80325（ＪＰ，Ａ) (58)調査した分野(Int.Cl.6，ＤＢ名) G02F 1/1335 610 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-73223 (JP, A) JP-A-64-23224 (JP, A) JP-A-5-34676 (JP, A) JP-A-5-234676 53103 (JP, A) JP-A-5-80325 (JP, A) (58) Fields investigated (Int. Cl. 6 , DB name) G02F 1/1335 610
Claims (1)
有し、 該一対の基板のいずれか一方と、その外方に設置された
該偏光板との間に位相差板が設置された液晶表示装置に
おいて、 該位相差板のレタデーションＲｅが６５０ｎｍ〜６９０
ｎｍの間の値に設定され、 該一対の基板の基板間隔ｄと該液晶の屈折率異方性Δｎ
との積ｄ・Δｎが０.６８〜０.７２の間の値に設定さ
れ、 該位相差板が設置された側の基板の液晶分子の配向軸と
該偏光板の吸収軸とのなす角αが−５°〜１５°の間の
値に設定され、 該位相差板が設置された側の基板に対向する基板の液晶
分子の配向軸と該偏光板の吸収軸とのなす角βが４０°
〜６０°の間の値に設定され、 該位相差板が設置された側の基板の液晶分子の配向軸と
該位相差板の光軸とのなす角θが６５°〜８５°の間の
値に設定され、 該液晶分子のツイスト角φが２４０°〜２６０°の間の
値に設定されている液晶表示装置。A pair of substrates disposed opposite to each other; a liquid crystal interposed between the pair of substrates; and a polarizing plate disposed outside each of the pair of substrates. In a liquid crystal display device in which a retardation plate is provided between any one of the polarizers and the polarizing plate provided outside thereof, the retardation Re of the retardation plate is 650 nm to 690.
nm between the pair of substrates, and the refractive index anisotropy Δn of the liquid crystal.
Is set to a value between 0.68 and 0.72, and the angle formed between the alignment axis of the liquid crystal molecules of the substrate on the side where the retardation plate is installed and the absorption axis of the polarizing plate. is set to a value between -5 ° and 15 °, and the angle β between the alignment axis of the liquid crystal molecules of the substrate facing the substrate on which the retardation plate is installed and the absorption axis of the polarizing plate is set. 40 °
The angle θ between the alignment axis of the liquid crystal molecules of the substrate on the side where the phase difference plate is installed and the optical axis of the phase difference plate is between 65 ° and 85 °. A twist angle φ of the liquid crystal molecules is set to a value between 240 ° and 260 °.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5185391A JP2968152B2 (en) | 1993-07-27 | 1993-07-27 | Liquid crystal display |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5185391A JP2968152B2 (en) | 1993-07-27 | 1993-07-27 | Liquid crystal display |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0743705A JPH0743705A (en) | 1995-02-14 |
| JP2968152B2 true JP2968152B2 (en) | 1999-10-25 |
Family
ID=16169994
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5185391A Expired - Lifetime JP2968152B2 (en) | 1993-07-27 | 1993-07-27 | Liquid crystal display |
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| Country | Link |
|---|---|
| JP (1) | JP2968152B2 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002174939A (en) | 2000-09-29 | 2002-06-21 | Ricoh Co Ltd | Image forming device |
| JP3771880B2 (en) | 2002-08-12 | 2006-04-26 | 株式会社沖データ | Toner recovery device |
| JP2004325480A (en) * | 2003-04-21 | 2004-11-18 | Nitto Denko Corp | Polarizing plate, its evaluation method, optical film, and liquid crystal display |
| DE10333913A1 (en) * | 2003-07-25 | 2005-02-24 | Krone Gmbh | Wiring connection module for circuit boards, uses contacts allowing longitudinal axes of insulation-piercing contacts to lie parallel to circuit-board surface |
| US7714945B2 (en) * | 2005-09-09 | 2010-05-11 | Jds Uniphase Corporation | Optimally clocked trim retarders |
-
1993
- 1993-07-27 JP JP5185391A patent/JP2968152B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0743705A (en) | 1995-02-14 |
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