JPH08152399A - Method and apparatus for measuring retardation of composite layer - Google Patents
Method and apparatus for measuring retardation of composite layerInfo
- Publication number
- JPH08152399A JPH08152399A JP7269450A JP26945095A JPH08152399A JP H08152399 A JPH08152399 A JP H08152399A JP 7269450 A JP7269450 A JP 7269450A JP 26945095 A JP26945095 A JP 26945095A JP H08152399 A JPH08152399 A JP H08152399A
- Authority
- JP
- Japan
- Prior art keywords
- sample
- composite layer
- analyzer
- polarizing plate
- retardation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Liquid Crystal (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
Description
【0001】[0001]
【発明の属する技術分野】本発明は、複合層試料、例え
ば液晶表示板に使用される偏光フィルムと位相差フィル
ムを積層した複合シートなどの複合層試料のレターデー
ションを測定する方法及び装置に関するものである。TECHNICAL FIELD The present invention relates to a method and an apparatus for measuring retardation of a composite layer sample, for example, a composite layer sample such as a composite sheet in which a polarizing film and a retardation film used in a liquid crystal display panel are laminated. Is.
【0002】[0002]
【従来の技術】液晶表示素子が多用されるに従い、液晶
表示板の大面積化と、可視方向の範囲拡大への要求が高
まってきた。そのためフィルム状の偏光フィルタ(偏光
フィルム)や位相差フィルムの特性をそれらのフィルム
の生産工程において簡単に測定できる技術の開発が望ま
れている。2. Description of the Related Art As liquid crystal display elements have been widely used, there has been an increasing demand for a liquid crystal display panel having a large area and a wide range in the visible direction. Therefore, it is desired to develop a technique capable of easily measuring the characteristics of a film-shaped polarizing filter (polarizing film) or a retardation film in the production process of those films.
【0003】通常、液晶ディスプレイ装置の表示板は、
光学要素として、液晶物質を封入した液晶セルの一方の
面に偏光フィルタが設けられ、他方の面(観察側)には
位相差フィルム、偏光フィルタ及び保護フィルムが順次
積層された構成を有している。位相差フィルムは液晶セ
ルによる偏光特性を補償するためのものであり、複屈折
性材料からなっている。このうち、偏光フィルタと位相
差フィルムを積層して貼り合わせた複合シート(「楕円
偏光板」とも呼ばれている。)の状態、例えば偏光フィ
ルタの偏光透過軸方向、位相差フィルムの光学主軸方向
及びレターデーション値などの検査が必要となる。Usually, the display board of a liquid crystal display device is
As an optical element, a polarization filter is provided on one surface of a liquid crystal cell in which a liquid crystal substance is sealed, and a retardation film, a polarization filter and a protective film are sequentially laminated on the other surface (observation side). There is. The retardation film is for compensating the polarization characteristics of the liquid crystal cell and is made of a birefringent material. Of these, the state of a composite sheet (also called “elliptic polarizing plate”) in which a polarizing filter and a retardation film are laminated and bonded, for example, the polarization transmission axis direction of the polarizing filter, the optical principal axis direction of the retardation film And the inspection of retardation value etc. is required.
【0004】また、液晶ディスプレイ装置の表示板で
は、表面に垂直な方向以外の方向からみた場合の特性、
すなわち視野角特性も重要な特性である。視野角特性の
評価のためには、複合シートの状態で測定光の入射角を
変化させたときのレターデーション値の測定が必要にな
る。しかし、現在は複合シートに白色光を入射させ、そ
の透過光の分光スペクトルにより評価を行なっている。Further, in the display panel of the liquid crystal display device, the characteristics when viewed from a direction other than the direction perpendicular to the surface,
That is, the viewing angle characteristic is also an important characteristic. In order to evaluate the viewing angle characteristics, it is necessary to measure the retardation value when the incident angle of the measurement light is changed in the state of the composite sheet. However, at present, white light is made incident on the composite sheet, and evaluation is performed by the spectrum of the transmitted light.
【0005】[0005]
【発明が解決しようとする課題】本発明者らは偏光フィ
ルタと位相差フィルムを積層した複合シートのレターデ
ーションの測定方法を提案している(特開平6−317
519号公報参照)。その方法で種々の複合シート試料
を測定したところ、試料によっては精度よく測定できる
ものとそうでないものとがあった。さらに検討を進めた
結果、複合シートに使用される偏光フィルタの偏光度が
約99%以上の場合には上記の測定値を高精度に求める
ことができるが、偏光度が充分でない場合、例えば偏光
度が99%未満の場合には、光学主軸方向とレターデー
ション値の算出結果が大きくばらつき、測定精度の低下
や、ときには測定不能の事態を生じることがわかった。
複合シートの視野角特性の評価を分光法により行なう方
法は、評価結果を定量化して表現するのが容易ではな
く、客観的な評価基準を設けることが難しい。The present inventors have proposed a method for measuring the retardation of a composite sheet in which a polarizing filter and a retardation film are laminated (JP-A-6-317).
519 publication). When various composite sheet samples were measured by the method, some samples could be measured accurately and others were not. As a result of further study, when the polarization degree of the polarizing filter used for the composite sheet is about 99% or more, the above measured value can be obtained with high accuracy. It has been found that when the degree is less than 99%, the calculation results of the retardation value and the optical principal axis direction are largely different, resulting in a decrease in measurement accuracy and sometimes an unmeasurable situation.
In the method of evaluating the viewing angle characteristics of the composite sheet by the spectroscopy, it is not easy to quantify and express the evaluation result, and it is difficult to set an objective evaluation standard.
【0006】本発明の第1の目的は、偏光フィルタ層と
複屈折性層を含む複合層試料で、その偏光フィルタ層の
偏光度が十分でない複合層試料の場合にも、その光学主
軸方向とレターデーション値を正確に測定できる方法及
び装置を提供することである。本発明の第2の目的は、
そのような複合層試料の場合にも、視野角特性の評価を
定量化できるようにすることである。The first object of the present invention is to provide a composite layer sample including a polarization filter layer and a birefringent layer, and in the case of a composite layer sample in which the polarization degree of the polarization filter layer is not sufficient, An object of the present invention is to provide a method and an apparatus capable of accurately measuring a retardation value. The second object of the present invention is to
Even in the case of such a composite layer sample, the evaluation of the viewing angle characteristics should be quantified.
【0007】[0007]
【課題を解決するための手段】本発明では、偏光フィル
タ層と複屈折性層を積層した複合層試料の偏光フィルタ
層側に補償用偏光板を配置し、かつ偏光フィルタ層と補
償用偏光板の偏光透過軸を互いに平行に保って偏光フィ
ルタ層の偏光特性を補償する。そして、レターデーショ
ン値等の測定では、その補償用偏光板側から測定光を照
射して、補償用偏光板及び複合層試料を透過した透過光
を検光子に通し、検光子の偏光方向を複合層試料の偏光
方向に対して相対的に回転させて、検光子透過光の強度
と検光子の偏光方位との関係を求める。これにより、著
しく測定精度が向上する。In the present invention, a compensating polarizing plate is arranged on the polarizing filter layer side of a composite layer sample in which a polarizing filter layer and a birefringent layer are laminated, and a polarizing filter layer and a compensating polarizing plate are arranged. The polarization transmission axes of are kept parallel to each other to compensate the polarization characteristics of the polarization filter layer. Then, in the measurement of the retardation value and the like, the measuring light is irradiated from the compensating polarizing plate side, the transmitted light that has passed through the compensating polarizing plate and the composite layer sample is passed through the analyzer, and the polarization directions of the analyzer are combined. By rotating the sample relative to the polarization direction of the layer sample, the relationship between the intensity of the light transmitted through the analyzer and the polarization direction of the analyzer is obtained. This significantly improves the measurement accuracy.
【0008】レターデーション値等の測定では、測定光
束を偏光子を通さずに、すなわち無偏光の状態で補償用
偏光板に照射する場合と、補償用偏光板の光入射側に検
光子と平行ニコル状態のような所定の偏光方位関係に保
った偏光子を配置し、その偏光子を通して測定光束を補
償用偏光板に照射する場合の両方を含んでいる。In measuring the retardation value and the like, the measurement light beam is applied to the compensation polarizing plate without passing through the polarizer, that is, in the unpolarized state, and when the light incident side of the compensation polarizing plate is parallel to the analyzer. This includes both cases in which a polarizer that maintains a predetermined polarization azimuth relationship such as the Nicol state is arranged, and the measurement light flux is irradiated to the compensation polarization plate through the polarizer.
【0009】視野角特性の評価を定量化できるようにす
るために、まず、複合層試料の面を測定光の光路に対し
て垂直状態に配置した状態で、検光子の偏光方向を複合
層試料の偏光方向に対して相対的に回転させて複合層試
料のレターデーション値及び光学主軸方向を求める。光
学主軸方向は主屈折率方向であり、屈折率が最大の方向
と最小の方向の2つの方向があり、この2つ方向は互い
に直交している。この2つの光学主軸方向のいずれでも
よいが、そのいずれかを傾斜軸として複合層試料の面を
傾斜させた状態で、再び検光子の偏光方向を複合層試料
の偏光方向に対して相対的に回転させて検光子透過光の
強度と検光子の偏光方位との関係を検出し、傾斜状態で
の複合層試料のレターデーション値を求める。In order to make it possible to quantify the evaluation of the viewing angle characteristics, first, with the plane of the composite layer sample arranged in a state perpendicular to the optical path of the measurement light, the polarization direction of the analyzer is set to the composite layer sample. The relative retardation value and the optical principal axis direction of the composite layer sample are obtained by rotating the sample relative to the polarization direction. The optical principal axis direction is the principal refractive index direction, and there are two directions of the maximum refractive index and the minimum refractive index, and these two directions are orthogonal to each other. Either of these two optical principal axis directions may be used, but the polarization direction of the analyzer is again set relative to the polarization direction of the composite layer sample in a state where the surface of the composite layer sample is tilted with one of them as the tilt axis. Rotation is performed to detect the relationship between the intensity of the light transmitted through the analyzer and the polarization direction of the analyzer, and the retardation value of the composite layer sample in the tilted state is obtained.
【0010】本発明のレターデーション測定装置は、測
定光路に測定光束を照射する光源部と、測定光路に偏光
フィルタ層と複屈折性層を積層した複合層試料を保持す
る試料台と、試料台に保持された複合層試料の測定光束
出射側に配置され回転可能に支持された検光子と、試料
台に保持された複合層試料の測定光束入射側に設けら
れ、検光子とは独立に回転可能に支持され、複合層試料
の偏光フィルタ層の偏光特性を補償する補償用偏光板
と、補償用偏光板から複合層試料を経て検光子を透過し
た光の透過光強度を検出する受光部と、検光子の回転角
度と受光部が検出した透過光強度とから複合層試料のレ
ターデーション及び光学主軸方向を算出する演算制御装
置とを備えている。The retardation measuring device of the present invention comprises a light source section for irradiating a measurement light beam on a measurement optical path, a sample stage for holding a composite layer sample in which a polarization filter layer and a birefringent layer are laminated on the measurement optical path, and a sample stage. The rotatably supported analyzer placed on the measurement light flux exit side of the composite layer sample held by and the measurement light flux entrance side of the composite layer sample held on the sample stand, and rotate independently of the analyzer. A compensating polarizing plate that is supported as much as possible and that compensates the polarization characteristics of the polarizing filter layer of the composite layer sample, and a light receiving unit that detects the transmitted light intensity of the light that has passed through the analyzer from the compensating polarizing plate through the composite layer sample. An arithmetic and control unit for calculating the retardation and the optical principal axis direction of the composite layer sample from the rotation angle of the analyzer and the transmitted light intensity detected by the light receiving section.
【0011】補償用偏光板の測定光束入射側にさらに偏
光子を配置してもよく、その場合には偏光子と検光子と
を互いに所定の偏光方位関係、例えば平行ニコル状態に
保って回転可能に支持する。補償用偏光板と検光子は測
定光路に対して挿脱可能に配置してもよく、偏光子を設
けた場合にはその偏光子も測定光路に対して挿脱可能に
配置してもよい。A polarizer may be further arranged on the side of the compensating polarizing plate where the measurement light beam enters, and in that case, the polarizer and the analyzer can be rotated while maintaining a predetermined polarization azimuth relationship with each other, for example, a parallel Nicol state. To support. The compensating polarizing plate and the analyzer may be arranged so that they can be inserted into and removed from the measurement optical path, and if a polarizer is provided, the polarizer can also be arranged so that they can be inserted into and removed from the measurement optical path.
【0012】本発明のレターデーション測定装置で視野
角特性の評価を定量化できるようにするためには、試料
台として、保持した複合層試料をその面内で回転させる
機構と、その複合層試料の表面に沿った一直線を中心と
してその複合層試料を傾斜させる傾斜機構とを備えたも
のを使用する。In order to make it possible to quantify the evaluation of the viewing angle characteristics with the retardation measuring apparatus of the present invention, a mechanism for rotating the held composite layer sample in its plane as a sample stage, and the composite layer sample And a tilting mechanism for tilting the composite layer sample about a straight line along the surface of the.
【0013】本発明において「複合層」とは、独立性を
有する、または有しないフィルム、シート、板等が直接
に接して重ねられ、又は介在物もしくは空間を介して間
接的に重ねられたものを言い、フィルム同志、シート同
志、板同志、あるいはこれら異種相互の重なりを含む。
また「積層」とは、接着材、粘着材、糊材などを用いる
か融合させることにより、固定的もしくは半固定的に、
貼合わせもしくは接合させたものに限らず、マジックテ
ープなどの部材を用いるか電気・磁気力や機械力その他
の力を利用して固定化的又は一時的に所定の位置関係に
重ね合わされているものも含むものとする。In the present invention, the "composite layer" is a layer in which films, sheets, plates or the like having or not having independence are directly stacked in contact with each other or indirectly stacked with inclusions or spaces. The terms include film comrades, sheet comrades, plate comrades, and overlapping of these different types.
In addition, "lamination" is fixed or semi-fixed by using or fusing an adhesive material, an adhesive material, a glue material, or the like,
Not limited to those that are pasted or joined together, but those that are fixed or temporarily superposed in a predetermined positional relationship by using members such as Velcro, or by utilizing electric / magnetic force, mechanical force, or other force. Shall also be included.
【0014】[0014]
【作用】本発明において測定に使用する光源からの光
は、白色光で、かつ偏光特性をもたない無偏光である。
偏光フィルタ層と複屈折性層を積層した複合層試料、例
えば偏光フィルムと位相差フィルムを貼り合わせた複合
シートに、偏光フィルム側より光を照射すると、位相差
フィルムには一定方向の直線偏光が入射し、複合シート
の透過光は楕円偏光となる。The light from the light source used for the measurement in the present invention is white light and is non-polarized light having no polarization characteristic.
A composite layer sample in which a polarizing filter layer and a birefringent layer are laminated, for example, a composite sheet obtained by laminating a polarizing film and a retardation film, when irradiated with light from the polarizing film side, linear retardation in a certain direction is generated in the retardation film. The incident light and the transmitted light of the composite sheet become elliptically polarized light.
【0015】偏光フィルムの偏光度が充分でない場合に
は、偏光フィルムは理想的な偏光フィルタとしては作用
しない。しかし、偏光フィルムの光入射側に偏光度の充
分高い補償用偏光板を配置し、偏光フィルムと補償用偏
光板の偏光透過軸を互いに平行に保つことによって、低
偏光度の偏光フィルムの特性が補償用偏光板により補償
される。補償用偏光板の偏光度は高ければ高いほど好ま
しいが、他の測定系の精度レベルを考慮すれば、99%
以上あれば十分である。このとき、レターデーションの
測定誤差数nm以下、光学主軸方向の測定誤差1度以下
程度の性能を満足できる。したがって、補償用偏光板及
び複合層試料の透過光を検光子に通し、検光子を複合層
試料に対して相対的に回転させて検光子の偏光方位と透
過光強度との関係を測定することにより、複合層試料の
光学主軸方向及びレターデーション値を正確に測定でき
るようになる。When the polarization degree of the polarizing film is not sufficient, the polarizing film does not act as an ideal polarizing filter. However, by disposing a compensating polarizing plate having a sufficiently high degree of polarization on the light incident side of the polarizing film and keeping the polarization transmission axes of the polarizing film and the compensating polarizing plate parallel to each other, the characteristics of the polarizing film having a low degree of polarization are It is compensated by the compensating polarizing plate. The higher the degree of polarization of the compensating polarizing plate is, the more preferable it is. However, considering the accuracy level of other measuring systems, it is 99%.
The above is enough. At this time, performance of a measurement error of retardation of several nm or less and a measurement error of 1 degree or less in the optical principal axis direction can be satisfied. Therefore, the transmitted light of the compensating polarizing plate and the composite layer sample is passed through the analyzer, and the analyzer is rotated relative to the composite layer sample to measure the relationship between the polarization direction of the analyzer and the transmitted light intensity. Thereby, the optical axis direction and the retardation value of the composite layer sample can be accurately measured.
【0016】複合層試料の透過光の楕円偏光の長軸方向
と楕円率は、検光子を複合層試料に対して相対的に回転
させることにより測定できるので、その結果から偏光フ
ィルムの偏光透過軸(及びそれと直交する偏光吸収軸)
と、位相差フィルムのレターデーション値及び光学主軸
方向を計算することができる。補償用偏光板の光入射側
に偏光子を配置し、その偏光子と検光子とを所定の偏光
方位関係に保って同期回転させる場合にもこれらの値を
算出することができる。これらの計算の詳細は実施例に
おいて述べる。The major axis direction and ellipticity of the elliptically polarized light of the transmitted light of the composite layer sample can be measured by rotating the analyzer relative to the composite layer sample. (And the polarization absorption axis orthogonal to it)
And the retardation value and the optical principal axis direction of the retardation film can be calculated. These values can be calculated also when a polarizer is arranged on the light incident side of the compensating polarizing plate and the polarizer and the analyzer are kept in a predetermined polarization azimuth relationship and synchronously rotated. Details of these calculations are given in the examples.
【0017】[0017]
【実施例】図1に本発明の複合層試料用のレターデーシ
ョン測定装置の実施例構成の概略を示す。図1におい
て、1は白色光源、2は光伝送路で、光伝送路2として
は例えばオプチカルファイバー束を用いる。3は光伝送
路2の出力から平行光束を得るための集光レンズ等の光
学系である。4は特定波長の光を透過させるためのフィ
ルタ部であり、透過波長の異なる複数個の狭帯域干渉フ
ィルタが、軸Bのまわりに回転可能な円板4a上に取り
付けられ、円板4aの回転により任意のフィルタが光路
上に選択配置されるように構成されており、フィルタの
切り替えにより白色光源1の出射光から特定の波長の光
が選択され、光軸Aを中心とする光路上に導かれる。EXAMPLE FIG. 1 schematically shows the configuration of an example of a retardation measuring apparatus for a composite layer sample of the present invention. In FIG. 1, 1 is a white light source, 2 is an optical transmission line, and an optical fiber bundle is used as the optical transmission line 2. Reference numeral 3 is an optical system such as a condenser lens for obtaining a parallel light flux from the output of the optical transmission line 2. Reference numeral 4 denotes a filter portion for transmitting light of a specific wavelength. A plurality of narrow band interference filters having different transmission wavelengths are attached on a disc 4a rotatable about an axis B, and the disc 4a rotates. Is configured so that an arbitrary filter is selectively arranged on the optical path. By switching the filters, light of a specific wavelength is selected from the emitted light of the white light source 1, and the light is guided to the optical path centered on the optical axis A. Get burned.
【0018】光軸A上には、フィルタ部4の下側に、水
平面内で偏光子8を光軸Aに対して前進と後退をさせる
偏光子用Xステージ5が設けられている。偏光子用Xス
テージ5上には偏光子8を回転させるための偏光子θス
テージ6、ステージ6の回転を駆動するモータ20、及
び偏光子8の回転角度位置決め用エンコーダ7が装着さ
れており、偏光子8は偏光子θステージ6に装着されて
いる。On the optical axis A, below the filter portion 4, there is provided a polarizer X stage 5 for advancing and retracting the polarizer 8 with respect to the optical axis A in a horizontal plane. A polarizer θ stage 6 for rotating the polarizer 8, a motor 20 for driving the rotation of the stage 6, and a rotation angle positioning encoder 7 for the polarizer 8 are mounted on the X stage 5 for the polarizer. The polarizer 8 is mounted on the polarizer θ stage 6.
【0019】光軸A上にはさらに、偏光子用Xステージ
5の下側に、補償用偏光板9を装着して回転させるため
の補償用偏光板用θステージ10、試料台11、及び水
平面内で検光子15を光軸Aに対して前進と後退をさせ
る検光子用Xステージ12が順に設けられている。補償
用偏光板用θステージ10にはそのステージ10の回転
を駆動するモータ19が設けられており、さらに補償用
偏光板9の回転角度検出用のエンコーダを設けておいて
もよい。検光子用Xステージ12上には検光子15を光
軸Aのまわりに回転させるための検光子用θステージ1
3、そのステージ13の回転を駆動するモータ21、及
び検光子15の回転角度位置決め用エンコーダ14が設
けられ、検光子15は検光子用θステージ13に装着さ
れている。On the optical axis A, the compensating polarizing plate θ stage 10 for mounting and rotating the compensating polarizing plate 9 below the X stage 5 for the polarizer, the sample stage 11, and the horizontal plane. An X stage 12 for an analyzer that sequentially advances and retracts the analyzer 15 with respect to the optical axis A is provided therein. A motor 19 for driving the rotation of the compensating polarizing plate θ stage 10 is provided, and an encoder for detecting the rotation angle of the compensating polarizing plate 9 may be further provided. On the analyzer X stage 12, the analyzer θ stage 1 for rotating the analyzer 15 around the optical axis A is provided.
3, a motor 21 for driving the rotation of the stage 13, and a rotation angle positioning encoder 14 for the analyzer 15 are provided, and the analyzer 15 is attached to the θ stage 13 for the analyzer.
【0020】光軸A上には、検光子15の下側、すなわ
ち光出射側にさらに受光素子16が配置されており、偏
光子用θステージ6と検光子用θステージ13は、それ
ぞれのエンコーダ7,14の角度位置信号を介して、演
算制御装置17により角度位置補正を行いながら、互い
に平行ニコルの状態を保って同期回転するように制御さ
れる。偏光子回転用のモータ20と検光子回転用のモー
タ21としては、ステッピングモータを使用するのが好
ましい。その場合、演算制御装置17からの制御パルス
によりモータ20,21が所定角度回転するごとに、回
転を一時停止して受光素子16の出力をサンプリングす
るようにしてもよいし、または、このサンプリング時間
はごく短いので、モータ20,21を連続回転させなが
ら受光素子16の出力をサンプリングさせることも可能
である。On the optical axis A, a light receiving element 16 is further arranged on the lower side of the analyzer 15, that is, on the light emitting side. The θ stage 6 for polarizer and the θ stage 13 for analyzer are respectively encoders. Through the angular position signals of 7 and 14, the arithmetic and control unit 17 performs angular position correction, and controls so as to maintain the parallel Nicols state and rotate synchronously. As the motor 20 for rotating the polarizer and the motor 21 for rotating the analyzer, it is preferable to use a stepping motor. In that case, each time the motors 20 and 21 rotate by a predetermined angle by the control pulse from the arithmetic and control unit 17, the rotation may be temporarily stopped and the output of the light receiving element 16 may be sampled. Since it is extremely short, it is possible to sample the output of the light receiving element 16 while continuously rotating the motors 20 and 21.
【0021】本発明装置はまた、複合層試料でない通常
試料のレターデーション測定にも使用することができ
る。通常試料の測定においては、補償用偏光板9を光路
から離脱させ、Xステージ5、12は左方向に前進させ
て図の状態とし、ステージ上に取りつけられた偏光子
8、検光子15を光路上に位置させた状態で、偏光子8
と検光子15は偏光方向を互いに平行ニコルの関係に保
ちながら光軸Aのまわりに回転させてレターデーション
の測定を行う。補償用偏光板9を光路から離脱させるに
は、θステージ10用にもXステージ5、12と同様の
光路への前進・後退用Xステージを設けてもよいし、ま
た補償用偏光板9をθステージ10に着脱できるように
θステージ10を構成してもよい。The apparatus of the present invention can also be used for the retardation measurement of a normal sample which is not a composite layer sample. In the measurement of a normal sample, the compensating polarizing plate 9 is separated from the optical path, the X stages 5 and 12 are moved leftward to the state shown in the figure, and the polarizer 8 and the analyzer 15 mounted on the stage are irradiated with light. The polarizer 8 is placed on the road.
The analyzer 15 is rotated around the optical axis A while maintaining the polarization directions in a parallel Nicol relationship with each other to measure the retardation. In order to separate the compensation polarizing plate 9 from the optical path, an X stage for advancing / retreating to the optical path similar to the X stages 5 and 12 may be provided for the θ stage 10, and the compensating polarizing plate 9 may be used. The θ stage 10 may be configured to be attachable to and detachable from the θ stage 10.
【0022】いずれにしても、本発明では、装置構成の
一部の変更又は切替えにより、通常試料のレターデーシ
ョン測定にも、また偏光フィルムと位相差フィルムを積
層した複合層試料のレターデーション測定にも利用する
ことができる。In any case, according to the present invention, the retardation of a normal sample or the retardation of a composite layer sample in which a polarizing film and a retardation film are laminated is measured by changing or switching a part of the apparatus configuration. Can also be used.
【0023】複合層試料のレターデーション測定は、偏
光子8があってもなくても行うことができる。複合層試
料測定では、試料台11に試料Sを偏光フィルムの方を
光源側(図では上側)に向けてセットする。そして、偏
光子8が光路に装着されていない場合は検光子用θステ
ージ13のみを回転させながら、また偏光子8が光路に
装着されている場合は偏光子用θステージ6と検光子用
θステージ13を同期させて回転させながら、透過光強
度の変化を測定する。具体的には、装置全体の制御及び
測定データのデータ処理を行う演算制御装置17は、補
償用偏光板9を回転させるモータ19の回転制御を行う
とともに、偏光子8が光路に装着されていない場合はエ
ンコーダ14の信号によりフィードバック制御を行って
検光子15を回転させ、偏光子8が光路に装着されてい
る場合は偏光子回転用モータ20と検光子回転用モータ
21を同期回転させるためにエンコーダ7,14の信号
によりフィードバック制御を行って偏光子8と検光子1
5を回転させる。そして、演算制御装置17は検光子1
5の回転の一定角度間隔、例えば1°間隔で受光素子1
6の出力を取り込んでデータ処理を行い、試料のレター
デーション値等を算出して結果を表示・記録装置18に
出力して表示、印字させる。The retardation measurement of the composite layer sample can be performed with or without the polarizer 8. In the composite layer sample measurement, the sample S is set on the sample table 11 with the polarizing film facing the light source side (upper side in the figure). Then, when the polarizer 8 is not mounted in the optical path, only the analyzer θ stage 13 is rotated, and when the polarizer 8 is mounted in the optical path, the polarizer θ stage 6 and the analyzer θ stage 13 are rotated. While rotating the stage 13 synchronously, the change in transmitted light intensity is measured. Specifically, the arithmetic and control unit 17, which controls the entire device and processes the measurement data, controls the rotation of the motor 19 for rotating the compensating polarizing plate 9, and the polarizer 8 is not attached to the optical path. In this case, feedback control is performed by the signal from the encoder 14 to rotate the analyzer 15, and when the polarizer 8 is mounted in the optical path, the polarizer rotating motor 20 and the analyzer rotating motor 21 are rotated in synchronization. Feedback control is performed by the signals of the encoders 7 and 14, and the polarizer 8 and the analyzer 1
Rotate 5. Then, the arithmetic and control unit 17 uses the analyzer 1
5, the light receiving element 1 at a constant angular interval of rotation, for example, at 1 ° intervals.
The output of No. 6 is taken in, data processing is performed, the retardation value of the sample is calculated, and the result is output to the display / recording device 18 for display and printing.
【0024】本発明による測定の主対象である複合層試
料の複合シートに使用されている偏光フィルムの偏光度
が99%未満の場合には、位相差フィルムのレターデー
ション値及び光学主軸の測定精度が悪くなるため、補償
用偏光板9を測定に使用する。その測定方法は、まずX
ステージ5,12を待避させて、偏光子8と検光子15
を光路から外す。試料台11に試料Sを偏光フィルムの
方を上にしてセットし、補償用偏光板(偏光度99%以
上)を一回転させながら透過光強度を測定することによ
り、複合シートの偏光フィルムの偏光透過軸と補償用偏
光板の偏光透過軸との直交位又は平行位のどちらかを求
める。両偏光透過軸の直交位は透過光量が最小になる位
置であり、平行位は透過光量が最大になる位置であり、
直交位の方が正確に求めやすい。そして、両偏光透過軸
の直交位を求めたときは、補償用偏光板を90°回転さ
せる。いずれにしても偏光フィルムの偏光透過軸と補償
用偏光板の偏光透過軸とを同一方向に重ね合わせ、つま
り両偏光透過軸を平行状態にする。When the polarization degree of the polarizing film used in the composite sheet of the composite layer sample, which is the main object of the measurement according to the present invention, is less than 99%, the retardation value of the retardation film and the measurement accuracy of the optical principal axis are measured. Therefore, the compensating polarizing plate 9 is used for the measurement. The measurement method is X
The polarizers 8 and the analyzer 15 are retracted by retracting the stages 5 and 12.
Out of the optical path. By setting the sample S on the sample table 11 with the polarizing film facing up and measuring the transmitted light intensity while rotating the compensating polarizing plate (polarization degree 99% or more) once, the polarization of the polarizing film of the composite sheet Either the orthogonal position or the parallel position between the transmission axis and the polarization transmission axis of the compensation polarizing plate is obtained. The orthogonal position of both polarization transmission axes is the position where the amount of transmitted light is minimum, the parallel position is the position where the amount of transmitted light is maximum,
The orthogonal position is easier to obtain accurately. Then, when the orthogonal position of both polarization transmission axes is obtained, the compensation polarizing plate is rotated by 90 °. In any case, the polarization transmission axis of the polarizing film and the polarization transmission axis of the compensating polarizing plate are superposed in the same direction, that is, both polarization transmission axes are in a parallel state.
【0025】次にXステージ12を前進させて検光子1
5を光路上に配置した後、検光子15を回転させながら
受光素子16により透過光強度の変化を測定し、複合シ
ートの偏光フィルムの透過透過軸方向と、位相差フィル
ムのレターデーション値及び光学主軸方向を算出する。Next, the X stage 12 is moved forward to move the analyzer 1
After arranging 5 on the optical path, the change of the transmitted light intensity is measured by the light receiving element 16 while rotating the analyzer 15, and the transmission / transmission axis direction of the polarizing film of the composite sheet, the retardation value of the retardation film, and the optical property are measured. Calculate the main axis direction.
【0026】複合シートのレターデーション算出は、次
のようにして行われる。まず、偏光子8を使用しない場
合について説明する。試料のレターデーション値を求め
る波長をλ、レターデーション値をR、試料の偏光フィ
ルムの偏光透過軸と位相差フィルムの光学主軸1(互い
に直交する2つの光学主軸1,2のうちのいずれか)と
のなす角をφ2とし、偏光フィルムの偏光透過軸と装置
の座標軸(光軸Aと直交する面内の一方向で、図2に示
されるx方向)とのなす角をφ1とする。φ1は別途測定
可能であり、これが0となるように試料台11上に試料
をセットすることも可能であるが、ここでは測定操作を
一般的に扱うために、φ1も未知とする。The retardation of the composite sheet is calculated as follows. First, the case where the polarizer 8 is not used will be described. The wavelength for obtaining the retardation value of the sample is λ, the retardation value is R, the polarization transmission axis of the polarizing film of the sample and the optical principal axis 1 of the retardation film (one of two optical principal axes 1 and 2 orthogonal to each other). the contact angle of phi 2 and (in one direction in a plane perpendicular to the optical axis a, x direction shown in FIG. 2) polarization transmission axis device coordinate axes of the polarizing film to the angle between the phi 1 . φ 1 can be measured separately, and the sample can be set on the sample table 11 so that it becomes 0, but here φ 1 is also unknown because the measurement operation is generally handled.
【0027】複合シート試料と検光子を透過した光の強
度をI(θ)とする。θは、検光子の基準方向からの回
転角である。図2を参照しながら説明を行う。試料の位
相差フィルムには偏光フィルムを透過した直線偏光が入
射しているので、その直線偏光の光強度をI0,振幅を
A0とする。位相差フィルムに入射した光の光学主軸1
方向の偏光成分の振幅はA0cosφ2、他方の光学主軸2
方向の偏光成分の振幅はA0sinφ2である。これら両成
分の検光子方向の成分A1,A2は、それぞれ、 A1 =A0cosφ2・cos(φ1+φ2−θ) A2 =A0sinφ2・sin(φ1+φ2−θ) となる。検光子透過光は上記2成分の光が位相差δで重
なったもので、位相差角δと位相差フィルムのレターデ
ーションRとは 2πR/λ=δ の関係であり、試料と検光子を透過した光の振幅をAと
すると、Aは余弦定理により、 A2 =I(θ) =A1 2+A2 2−2A1A2cosδ =A0 2{cos2φ2・cos2(φ1+φ2−θ)+sin2φ2・sin2(φ1+φ2−θ) −2cosφ2・sinφ2・cos(φ1+φ2−θ)sin(φ1+φ2−θ)cosδ} ・・・(1) となる。The intensity of light transmitted through the composite sheet sample and the analyzer is I (θ). θ is the rotation angle of the analyzer from the reference direction. Description will be given with reference to FIG. Since the linearly polarized light transmitted through the polarizing film is incident on the retardation film of the sample, the light intensity of the linearly polarized light is I 0 and the amplitude is A 0 . Optical main axis 1 of light incident on the retardation film
The amplitude of the polarization component in the direction is A 0 cosφ 2 , the other optical principal axis 2
The amplitude of the polarization component in the direction is A 0 sin φ 2 . The analyzer-direction components A 1 and A 2 of these two components are respectively A 1 = A 0 cos φ 2 · cos (φ 1 + φ 2 −θ) A 2 = A 0 sin φ 2 · sin (φ 1 + φ 2 − θ). The transmitted light of the analyzer is the light of the above two components overlapped with the phase difference δ, and the retardation angle δ and the retardation R of the retardation film have a relationship of 2πR / λ = δ, and the light transmitted through the sample and the analyzer. When the amplitude of the light and a, the a is the cosine theorem, a 2 = I (θ) = a 1 2 + a 2 2 -2A 1 a 2 cosδ = a 0 2 {cos 2 φ 2 · cos 2 (φ 1 + φ 2 -θ) + sin 2 φ 2 · sin 2 (φ 1 + φ 2 -θ) -2cosφ 2 · sinφ 2 · cos (φ 1 + φ 2 -θ) sin (φ 1 + φ 2 -θ) cosδ} ··· (1)
【0028】上式のA2 が受光素子16の出力である。
ここで求めたいのは、cosδであるが、直接求まるのは
I(θ)とθであり、φ1 及びφ2 は未知数であるが定
数であるから、cosφ2=K, sinφ2=L, φ1+φ2−
θ=Ψとおいて上式を書き替えると、 I(θ)=(K2cos2Ψ+L2sin2Ψ−2KLcosΨsinΨcosδ)A0 2 となる。これをさらに書き替えると、 L2=1−K2、K2=1−L2、K2+L2=1 の関係があるので、上式は、 I(θ)=(K2cos2Ψ+(1−K2)sin2Ψ−KLsin2Ψcosδ)A0 2 および、 I(θ)={(1−L2)cos2Ψ+L2sin2Ψ−KLsin2Ψccosδ}A0 2 となる。この2式を加えて2で割ると、 I(θ) ={K2cos2Ψ-sin2Ψ)+sin2Ψ-L2(cos2Ψ-sin2Ψ)+cos2Ψ-2KLsin2Ψcosδ }A0 2/2 ={(K2−L2)cos2Ψ−2KLsin2Ψcosδ+1}A0 2/2 となる。この式から、I(θ)は検光子の半回転の間に
1周期の変化を行う。透過光強度の最大は、この式で s
in2Ψ=0になる場合、最小は cos2Ψ=0になる場合
であることから、 Imax =A0 2・K2 Imin =A0 2(K2−2KLcosδ)/2 となる。また、K=cosφ2 ,L=sinφ2 であるから,
上式からLを消去して, Imin =A0 2{1−2K(1−K2)1/2−cosδ}/2 となる。そこで、このImin のKにImax1/2/A0を代
入すると、 cosδ={(A0 2−2Imin)−2Imax1/2(A0 2−Imax)1/2}/A0 2 となり、cosδを求めることができるので、cosδからレ
ターデーションRを決定することができる。A 2 in the above equation is the output of the light receiving element 16.
Here want sought is a cos [delta], the obtained direct is theta and I (theta), because although phi 1 and phi 2 are unknown constants, cosφ 2 = K, sinφ 2 = L, φ 1 + φ 2 −
By rewriting the above equation with θ = Ψ, I (θ) = (K 2 cos 2 Ψ + L 2 sin 2 Ψ-2KLcos Ψsin Ψcos δ) A 0 2 . If this is further rewritten, there is a relation of L 2 = 1-K 2 , K 2 = 1-L 2 , and K 2 + L 2 = 1. Therefore, the above equation is I (θ) = (K 2 cos 2 Ψ + (1-K 2) sin 2 Ψ-KLsin2Ψcosδ) a 0 2 and becomes I (θ) = {(1 -L 2) cos 2 Ψ + L 2 sin 2 Ψ-KLsin2Ψccosδ} a 0 2. Adding these two formulas and dividing by two gives I (θ) = (K 2 cos 2 Ψ-sin 2 Ψ) + sin 2 Ψ-L 2 (cos 2 Ψ-sin 2 Ψ) + cos 2 Ψ-2KLsin2 Ψcosδ}. the a 0 2/2 = {( K 2 -L 2) cos2Ψ-2KLsin2Ψcosδ + 1} a 0 2/2. From this equation, I (θ) changes by one cycle during half rotation of the analyzer. The maximum transmitted light intensity is s
When in2Ψ = 0, the minimum is when cos2Ψ = 0. Therefore, Imax = A 0 2 · K 2 Imin = A 0 2 (K 2 −2KL cos δ) / 2. Further, since it is K = cosφ 2, L = sinφ 2,
By deleting L from the above equation, Imin = A 0 2 {1-2K (1-K 2 ) 1 / 2-cosδ} / 2. Therefore, substituting Imax1 / 2 / A 0 to K of this Imin, cosδ = {(A 0 2 -2Imin) -2Imax1 / 2 (A 0 2 -Imax) 1/2} / A 0 2 . Therefore, the cos [delta] Since it can be obtained, the retardation R can be determined from cos δ.
【0029】上式でA0 2 は、試料の偏光フィルムを透
過した光の強度であり、図1の装置において、試料をそ
の偏光フィルム側を検光子側に向けてセットし、検光子
を回転させたときの受光素子出力の最大値として予め求
めておくことができる。また試料の偏光フィルムの偏光
透過軸と位相差フィルムの光学主軸1とのなす角φ
2は、前記のImax =A0 2・K2 からK2 を求めると、K
の定義 K= cosφ2 から求めることができる。In the above equation, A 0 2 is the intensity of light transmitted through the polarizing film of the sample, and in the apparatus of FIG. 1, the sample is set with its polarizing film side facing the analyzer side and the analyzer is rotated. It can be obtained in advance as the maximum value of the output of the light-receiving element when it is caused. In addition, the angle φ formed by the polarization transmission axis of the sample polarizing film and the optical axis 1 of the retardation film
2, when obtaining the K 2 from the above Imax = A 0 2 · K 2 , K
Can be obtained from K = cos φ 2 .
【0030】上述したものは、本発明でレターデーショ
ンを求めるためのデータ処理法の一例であって、実際に
レタデーションを求める方法は上述したところ所に限ら
ない。例えば予め前記(1)式によってImin/A0 2 と
Imax/A0 2 値の種々の組合せに対して、レターデーシ
ョンとφ2 を計算して表を作成しておき、実測されたI
min ,Imax から内挿演算で試料のレターデーションと
φ2 を引き当てるようにしてもよい。The above is one example of the data processing method for obtaining the retardation in the present invention, and the method for actually obtaining the retardation is not limited to the above. For example, the retardation and φ 2 are calculated in advance for various combinations of Imin / A 0 2 and Imax / A 0 2 values according to the above formula (1) to prepare a table, and the measured I
The retardation of the sample and φ 2 may be assigned from min and Imax by interpolation.
【0031】上述の実施例での演算は、図1の装置で偏
光子用Xステージ5上に取り付けられている偏光子用θ
ステージ6を図で右方に後退させて偏光子8を光路から
離脱させて行われるものであり、数式的扱いが簡単であ
る。しかし数式的扱いは多少複雑になるが、偏光子8を
光路に置いたままでも上述した複合シートのレターデー
ションを測定することができる。ここにそのような実施
例を述べる。この場合、Xステージ5,12を前進させ
て偏光子8と検光子15を光路上に配置した後、偏光子
8と検光子15を同期させて回転させながら受光素子1
6により透過光強度の変化を測定し、複合シートの偏光
フィルムの透過透過軸方向と、位相差フィルムのレター
デーション値及び光学主軸方向を算出する。The calculation in the above-described embodiment is carried out by the θ for the polarizer mounted on the X stage 5 for the polarizer in the apparatus of FIG.
This is performed by retreating the stage 6 to the right in the figure and removing the polarizer 8 from the optical path, and mathematical treatment is simple. However, although the mathematical treatment becomes somewhat complicated, the retardation of the above-mentioned composite sheet can be measured even when the polarizer 8 is left in the optical path. Such an embodiment is described here. In this case, the X stages 5 and 12 are moved forward to arrange the polarizer 8 and the analyzer 15 on the optical path, and then the light receiving element 1 is rotated while synchronizing the polarizer 8 and the analyzer 15.
The change in transmitted light intensity is measured according to 6, and the transmission / transmission axis direction of the polarizing film of the composite sheet, the retardation value of the retardation film, and the optical principal axis direction are calculated.
【0032】偏光子8と検光子15は互いに平行ニコル
の状態とする。前述の実施例と同じ符号を用いると、受
光素子16に入射する光の強度I(θ)は、次式で表せ
る。 I(θ) =A0 2{cos2φ2・cos2(φ1+φ2-θ)+sin2φ2・sin2(φ1+φ2-θ) -2cosφ2・sinφ2・cos(φ1+φ2-θ)sin(φ1+φ2-θ)cosδ}・cos 2 (φ1-θ) ・・・(2) この式は、(1)式に cos2(φ1−θ)の項が余分にかか
ったものとなっている。The polarizer 8 and the analyzer 15 are parallel Nicols to each other.
State. If the same reference numerals are used as in the previous embodiment,
The intensity I (θ) of the light incident on the optical element 16 can be expressed by the following equation.
It I (θ) = A0 2(cos2φ2・ Cos2(φ1+ φ2-θ) + sin2φ2・ Sin2(φ1+ φ2-θ) -2 cosφ2・ Sinφ2・ Cos (φ1+ φ2-θ) sin (φ1+ φ2-θ) cosδ} ・ cos 2 (φ1-θ) ・ ・ ・ (2) This equation is cos in the equation (1).2(φ1Is an extra term for −θ)
It has become a thing.
【0033】このため、I(θ)の極座標グラフは単純
な繭形とか楕円あるいはS字形だけでなく、図3に示す
ような4葉形になることがある。したがって、I(θ)
の最大、最小の値から cosδを簡単に求めることは一般
的にはできない。いくつかのθの値に対してI(θ)を
実測し、上式に代入して cosδ と cosφ2 についての
連立方程式として解くのが一般的方法である。この場
合、試料の偏光フィルム部分の偏光透過軸の方向を検出
してこれを装置の基準方向xに合わせる。つまりφ1 =
0とするようにすれば、式の扱いはいくらか簡単にな
る。Therefore, the polar coordinate graph of I (θ) may be not only a simple cocoon shape, an ellipse or an S shape, but also a four-lobed shape as shown in FIG. Therefore, I (θ)
It is generally not possible to easily find cos δ from the maximum and minimum values of. It is a general method to actually measure I (θ) for some values of θ and substitute it in the above equation to solve as a simultaneous equation for cosδ and cosφ 2 . In this case, the direction of the polarization transmission axis of the polarizing film portion of the sample is detected and this is aligned with the reference direction x of the device. That is φ 1 =
Setting it to 0 makes the expression somewhat easier to handle.
【0034】偏光フィルム部分の偏光透過軸の方向を検
出するには、偏光子8を測定光路から外し、試料をその
偏光フィルム側を検光子側に向けてセットし、透過光強
度が最大になる検光子の方向を検出するか、透過光強度
が最小になる方向に90°を加えた方向を検出すればよ
い。連立方程式を解く演算を行う代わりに、予め色々な
レターデーションの値とφ2 の値との組合せについて、
前記(2)式によって、I(θ)の極座標グラフを計算
して作成しておき、実測のI(θ)のグラフからレター
デーションとφ2 の概略の見当を付け、レターデーショ
ンとφ2 を仮定して極座標グラフを仮定し、実測の形に
なるように、計算を繰り返すようにしてもよい。この方
法は、前述の実施例でも応用できる。何れにしても、本
発明方法の原理を実現するデータ処理の具体的方法は任
意である。In order to detect the direction of the polarization transmission axis of the polarizing film portion, the polarizer 8 is removed from the measurement optical path and the sample is set with the polarizing film side facing the analyzer side, and the transmitted light intensity becomes maximum. It suffices to detect the direction of the analyzer or the direction obtained by adding 90 ° to the direction in which the transmitted light intensity becomes the minimum. Instead of performing the operation to solve the simultaneous equations, about the combination of various values of retardation and φ 2 in advance,
By the equation (2), previously created by calculating the polar coordinate graph of I (theta), the graph with the registration of the outline of the retardation and phi 2 from I (theta) of the actual measurement, a retardation and phi 2 Assuming that a polar coordinate graph is assumed, the calculation may be repeated so that the actual measurement shape is obtained. This method can also be applied to the above-mentioned embodiment. In any case, the specific method of data processing for realizing the principle of the method of the present invention is arbitrary.
【0035】上述した各実施例とも試料の位相差フイル
ムの部分の2軸方向の透過率は等しいとしているが、そ
の2つの透過率が互いに異なっている場合がある。この
透過率の比をa(2軸方向の何れを分母にするかにより
a<1又はa>1となるが、a<1とする)とすると、
前記(1),(2)式はそれぞれ次の(1’),(2’)式
のようになる。 I(θ) =A0 2{a2cos2φ2・cos2(φ1+φ2-θ)+sin2φ2・sin2(φ1+φ2-θ) −2acosφ2・sinφ2・cos(φ1+φ2-θ)sin(φ1+φ2-θ)cosδ}……( 1’) I(θ) =A0 2{a2cos2φ2・cos2(φ1+φ2-θ)+sin2φ2・sin2(φ1+φ2-θ) −2acosφ2・sinφ2・cos(φ1+φ2-θ)sin(φ1+φ2-θ)cosδ}・cos2 (φ1-θ) ……(2’)In each of the above-mentioned embodiments, the transmittance of the retardation film portion of the sample in the biaxial directions is equal, but the two transmittances may be different from each other. If this transmittance ratio is a (a <1 or a> 1 depending on which of the two axis directions is the denominator, a <1),
The equations (1) and (2) become the following equations (1 ') and (2'), respectively. I (θ) = A 0 2 {a 2 cos 2 φ 2 · cos 2 (φ 1 + φ 2 -θ) + sin 2 φ 2 · sin 2 (φ 1 + φ 2 -θ) -2acosφ 2 · sinφ 2 · cos (φ 1 + φ 2 -θ) sin (φ 1 + φ 2 -θ) cos δ} …… (1 ') I (θ) = A 0 2 {a 2 cos 2 φ 2・ cos 2 (φ 1 + φ 2 -θ) + sin 2 φ 2 · sin 2 (φ 1 + φ 2 -θ) -2acosφ 2 · sinφ 2 · cos (φ 1 + φ 2 -θ) sin (φ 1 + φ 2 -θ) cosδ}・ Cos 2 (φ 1 -θ) …… (2 ')
【0036】なお上記において、複合シートの偏光フィ
ルムの偏光透過軸方向φ1とこの偏光透過軸方向と位相
差フィルムの光学主軸1方向とのなす角φ2に関し、複
合層試料のレターデーションRの決定に際して、φ1を
当初得られた値の前後に数段階に微小値変化させ、φ1
の値毎にφ2,Rを演算し、残差の収束値が最小となる
ように、φ1,φ2,Rの値を決定すれは、測定精度はさ
らに向上する。In the above description, regarding the polarization transmission axis direction φ 1 of the polarizing film of the composite sheet and the angle φ 2 formed between this polarization transmission axis direction and the optical principal axis 1 direction of the retardation film, the retardation R of the composite layer sample At the time of determination, φ 1 is slightly changed in several steps before and after the initially obtained value, and φ 1
If φ 2 and R are calculated for each value of φ and the values of φ 1 , φ 2 and R are determined so that the residual convergence value is minimized, the measurement accuracy is further improved.
【0037】以上の実施例は、試料台11は複合層試料
Sをその表面が光軸Aに対して垂直に保持するものとし
て説明している。しかし、複合層試料Sの視野角特性を
評価するためには、試料台11は複合層試料Sをその面
内で回転できるとともに、複合層試料Sの表面に沿う一
直線を中心として試料を傾けることができるものである
必要がある。図4はそのような試料台11aの一例を示
したものであり、その試料台11aの詳細を図5に示
す。試料保持部70は中央に穴72が設けられ、裏面が
リング状にくり抜かれて凹部が形成され、上面には試料
を押さえて保持する押え板74が2箇所に設けられてい
る。試料保持部70の裏面の凹部と嵌合するリング状の
凸部76をもつ回転台78が基板80に取りつけられ、
試料保持部70を試料面に垂直な軸のまわりに回転可能
に保持している。回転台78に嵌め込まれた試料保持部
70の側面とステッピングモータ82の回転軸に取りつ
けられたプーリ84との間にベルト86が装着され、モ
ータ82によって試料保持部70が回転する。モータ8
2も基板80に取りつけられており、プーリ84と試料
保持部70が一平面内に配置されるように、モータ82
と回転台78の取りつけ面が構成されている。基板80
の一対の側面には軸88と90が取りつけ、られ、軸8
8と90の中心軸が試料保持部70の表面にくるように
配置されている。これらの軸80と90が測定装置本体
に支持されている。一方の軸88にはプーリ62が取り
つけられ、測定装置本体側に設けられたステッピングモ
ータ68のプーリ66とこのプーリ62との間にベルト
64がかけられ、基板80がモータ68により傾斜させ
られる。演算制御装置17はモータ68,82の動作も
制御する。In the above embodiments, the sample table 11 is described as holding the composite layer sample S so that its surface is perpendicular to the optical axis A. However, in order to evaluate the viewing angle characteristics of the composite layer sample S, the sample stage 11 can rotate the composite layer sample S in its plane and tilt the sample about a straight line along the surface of the composite layer sample S. Need to be able to. FIG. 4 shows an example of such a sample table 11a, and the details of the sample table 11a are shown in FIG. The sample holder 70 has a hole 72 in the center, the back surface is hollowed out in a ring shape to form a recess, and the upper surface is provided with two holding plates 74 for holding and holding the sample. A turntable 78 having a ring-shaped convex portion 76 that fits into the concave portion on the back surface of the sample holding unit 70 is attached to the substrate 80,
The sample holder 70 is held rotatably around an axis perpendicular to the sample surface. A belt 86 is mounted between the side surface of the sample holder 70 fitted on the rotary table 78 and the pulley 84 attached to the rotating shaft of the stepping motor 82, and the motor 82 rotates the sample holder 70. Motor 8
2 is also attached to the substrate 80, and the motor 82 is arranged so that the pulley 84 and the sample holder 70 are arranged in one plane.
And a mounting surface of the turntable 78 is configured. Board 80
The shafts 88 and 90 are attached to the pair of side surfaces of the
The central axes of 8 and 90 are arranged so as to come to the surface of the sample holder 70. These shafts 80 and 90 are supported by the measuring device body. A pulley 62 is attached to one of the shafts 88, a belt 64 is hung between the pulley 66 of a stepping motor 68 provided on the measuring apparatus main body side and the pulley 62, and the substrate 80 is tilted by the motor 68. The arithmetic and control unit 17 also controls the operations of the motors 68 and 82.
【0038】図4,5の試料台11aを用いて複合層試
料の視野角特性を測定するときは次のように行なう。ま
ず、複合層試料Sを試料保持部70に取りつけ、試料の
表面が光軸Aに対して垂直になるように配置し、検光子
15を1回転させて複合層試料SのレターデーションR
と光学主軸方向を算出する。When the viewing angle characteristics of the composite layer sample are measured using the sample table 11a shown in FIGS. First, the composite layer sample S is attached to the sample holder 70, the sample surface is arranged so as to be perpendicular to the optical axis A, and the analyzer 15 is rotated once to rotate the retardation R of the composite layer sample S.
And the optical principal axis direction is calculated.
【0039】つぎに、モータ82を駆動して、2つの光
学主軸方向の何れかが軸88と90の中心軸(傾斜軸)
の方向になるように複合層試料Sを面内で回転させる。
そして、モータ68を駆動して、その傾斜軸を中心とし
て試料保持部70を一定角、例えば10度傾斜させ、再
び検光子15を1回転させて複合層試料Sのレターデー
ションRを算出する。このようにして、複合層試料Sの
傾斜を変えながらレターデーションを求めていく。演算
制御装置17では、試料保持部70の傾斜角度をモータ
68の駆動パルスによって読み取る。Next, the motor 82 is driven so that one of the two optical principal axis directions is the central axis (tilt axis) of the axes 88 and 90.
The composite layer sample S is rotated in the plane so as to be in the direction of.
Then, the motor 68 is driven, the sample holding unit 70 is tilted at a constant angle, for example, 10 degrees around the tilt axis, and the analyzer 15 is rotated once again to calculate the retardation R of the composite layer sample S. In this way, the retardation is obtained while changing the inclination of the composite layer sample S. The arithmetic and control unit 17 reads the inclination angle of the sample holder 70 by the drive pulse of the motor 68.
【0040】[実験例1]a)図1の構成の装置におい
て、偏光度95.0%の偏光板(偏光板Bとする)をそ
の偏光透過軸と装置の座標軸xとのなす角が90度とな
るように試料台11に固定し、この偏光板に位相差フィ
ルムをその光学主軸が偏光板の偏光透過軸と30度(φ
2)をなすように積層して複合シート試料とする。偏光
子8と検光子15を光路上に置いて両者を平行ニコルの
関係に保って同期回転させ、例えばその10度の回転ご
とに透過光強度を測定する。この測定結果から複合シー
トの偏光板の偏光透過軸と装置の座標軸xとのなす角φ
1、偏光板の偏光透過軸と位相差フィルムの光学主軸と
のなす角φ2(deg.)及び位相差フィルムのレターデー
ション値Rを算出した。同じ内容の測定を、1試料の測
定毎に、位相差フィルムのみを交換し、同一の偏光板を
共通に用いて、9種類の位相差フィルムについて行っ
た。この結果を表1に示す。R0は9種類の位相差フィ
ルム単体でのレターデーション値である。[Experimental Example 1] a) In the device having the configuration shown in FIG. 1, a polarizing plate (polarizing plate B) having a polarization degree of 95.0% forms an angle of 90 between the polarization transmission axis and the coordinate axis x of the device. The polarizing plate is fixed on the sample table 11 so that the optical axis of the polarizing plate is 30 ° (φ).
2 ) Laminate to form a composite sheet sample. The polarizer 8 and the analyzer 15 are placed on the optical path and kept in a parallel Nicol relationship for synchronous rotation, and the transmitted light intensity is measured, for example, every 10 degrees of rotation. From this measurement result, the angle φ formed between the polarization transmission axis of the polarizing plate of the composite sheet and the coordinate axis x of the device
1. The angle φ 2 (deg.) Formed by the polarization transmission axis of the polarizing plate and the optical principal axis of the retardation film and the retardation value R of the retardation film were calculated. The measurement of the same content was performed for each of the 9 types of retardation films by exchanging only the retardation film and commonly using the same polarizing plate for each measurement of one sample. Table 1 shows the results. R 0 is the retardation value of 9 types of retardation films alone.
【0041】b)図1の構成の装置において、上記a)
と同じ複合シート試料に対して、補償用偏光板(偏光度
99.9%)9(偏光板Aとする)を図のごとく試料の
光入射側に置き、偏光子8と検光子15を光路上から離
脱させた状態で補償用偏光板9を光路上で回転して透過
光強度の変化を検出し、補償用偏光板9の偏光透過軸を
試料の偏光板の偏光透過軸と平行になるように設定し
た。このときの補償用偏光板9の回転角度位置から複合
シートの偏光板の偏光透過軸の方位が装置の座標軸xと
なす角φ1(deg.)を得た。B) In the device having the configuration shown in FIG.
For the same composite sheet sample as above, a compensating polarizing plate (polarization degree 99.9%) 9 (polarizing plate A) is placed on the light incident side of the sample as shown in the figure, and the polarizer 8 and the analyzer 15 are exposed to light. The polarization plate for compensation 9 is rotated on the optical path in a state where it is separated from the path to detect a change in transmitted light intensity, and the polarization transmission axis of the polarization plate for compensation 9 becomes parallel to the polarization transmission axis of the polarization plate of the sample. Was set. The angle φ 1 (deg.) Formed by the azimuth of the polarization transmission axis of the polarizing plate of the composite sheet and the coordinate axis x of the device was obtained from the rotation angle position of the compensation polarizing plate 9 at this time.
【0042】補償用偏光板9の偏光透過軸と試料の偏光
板の偏光透過軸とを平行に設定したこの状態を保って、
偏光子8と検光子15を光路上に戻し、両者を平行ニコ
ルの関係に保って同期回転させ、その10度の回転ごと
に透過光強度を測定し、この測定結果から複合シートの
偏光板の偏光透過軸に対して位相差フィルムの光学主軸
のなす角φ2(deg.)及び位相差フィルムのレターデー
ション値Rを算出した。同じ内容の測定を、1試料の測
定毎に、位相差フィルムのみを交換し、同一の偏光板を
共通に用いて、9種類の位相差フィルムについて行っ
た。この結果を上記a)と対応して表1に示した。With the polarization transmission axis of the compensating polarizing plate 9 and the polarization transmission axis of the sample polarizing plate set parallel to each other,
The polarizer 8 and the analyzer 15 are returned to the optical path, both are rotated synchronously while maintaining the relationship of parallel Nicols, and the transmitted light intensity is measured for each rotation of 10 degrees, and from this measurement result, the polarizing plate of the composite sheet The angle φ 2 (deg.) Formed by the optical principal axis of the retardation film with respect to the polarization transmission axis and the retardation value R of the retardation film were calculated. The measurement of the same content was performed for each of the 9 types of retardation films by exchanging only the retardation film and commonly using the same polarizing plate for each measurement of one sample. The results are shown in Table 1 in correspondence with the above a).
【0043】[0043]
【表1】 a)補償用偏光板なし b)補償用偏光板あり ─────────── ────────── サンプル R0 R φ1(°) φ2(°) R φ1(°) φ2(°) 1 152.5 124.0 84 -44 153.0 90 -31 2 218.7 196.0 86 -32 220.4 90 -28 3 241.2 223.5 87 -31 243.3 90 -30 4 271.9 261.7 89 -30 266.2 90 -30 5 362.3 350.7 -88 -27 367.0 90 -30 6 382.9 365.0 -87 -25 386.8 90 -30 7 413.4 393.0 -86 -24 417.7 90 -30 8 395.0 378.1 -87 -25 400.9 90 -30 9 416.8 393.1 -86 -23 423.1 90 -30[Table 1] a) without compensation polarizing plate b) with compensation polarizing plate ─────────── ────────── Sample R 0 R φ 1 (°) φ 2 (°) R φ 1 (°) φ 2 (°) 1 152.5 124.0 84 -44 153.0 90 -31 2 218.7 196.0 86 -32 220.4 90 -28 3 241.2 223.5 87 -31 243.3 90 -30 4 271.9 261.7 89 -30 266.2 90 -30 5 362.3 350.7 -88 -27 367.0 90 -30 6 382.9 365.0 -87 -25 386.8 90 -30 7 413.4 393.0 -86 -24 417.7 90 -30 8 395.0 378.1 -87 -25 400.9 90 -30 9 416.8 393.1 -86 -23 423.1 90 -30
【0044】c)このa)、b)の結果を比較すると、
補償用偏光板を使用しないときは、レターデーション値
Rで平均5%、最大20%程度の大きな誤差があり、ま
た光学主軸方向φ2では平均5度前後、最大14度の相
当に大きな誤差を生じた。これに対して、補償用偏光板
を使用した場合には、レターデーション値Rは±2%以
下、平均1.4%の誤差であり、光学主軸方向φ2は殆ど
誤差を生じなかった。従って本発明により、偏光度の良
くない偏光フィルムを用いた複合シートでも、充分な精
度と信頼性を確保できることが判明した。偏光板Bに代
えて偏光度が99.9%の偏光板を使用して上記の
a),b)と同様の測定を行なった。その結果、a),
b)両測定とも精度よくレターデーション値及び光学主
軸方向が測定できた。C) Comparing the results of a) and b),
When the compensating polarizing plate is not used, the retardation value R has a large error of about 5% on average and about 20% at the maximum, and a considerably large error of about 5 ° on average and 14 ° at the maximum in the optical axis direction φ 2. occured. On the other hand, when the compensating polarizing plate was used, the retardation value R had an error of ± 2% or less and an average of 1.4%, and there was almost no error in the optical principal axis direction φ 2 . Therefore, according to the present invention, it has been found that even a composite sheet using a polarizing film having a poor degree of polarization can ensure sufficient accuracy and reliability. The same measurement as the above a) and b) was performed using a polarizing plate having a polarization degree of 99.9% instead of the polarizing plate B. As a result, a),
b) In both measurements, the retardation value and the optical principal axis direction could be measured accurately.
【0045】[実験例2]実験例1と同じ複合シートに
ついて、図1の構成において、偏光子8を測定光路から
離脱させた状態で、補償用偏光板9を光路から離脱させ
た状態で実験例1のa)と同様の測定を行い、補償用偏
光板9を光路に置いた状態で、b)と同様の測定を行っ
た。この結果は表2に示す。[Experimental Example 2] The same composite sheet as in Experimental Example 1 was tested with the configuration of FIG. 1 with the polarizer 8 removed from the measurement optical path and the compensation polarizing plate 9 removed from the optical path. The same measurement as in a) of Example 1 was performed, and the same measurement as in b) was performed with the polarizing plate 9 for compensation placed in the optical path. The results are shown in Table 2.
【0046】[0046]
【表2】 a)補償用偏光板なし b)補償用偏光板あり ─────────── ────────── サンプル R0 R φ1(°) φ2(°) R φ1(°) φ2(°) 1 152.5 153.0 89 30 152.0 89 31 2 218.7 219.7 89 29 218.7 90 29 3 241.2 238.7 90 29 246.0 89 31 4 271.9 260.6 90 30 273.1 89 31 5 362.3 364.7 89 31 363.8 90 30 6 382.9 385.1 89 30 385.9 90 30 7 413.4 415.1 90 29 417.1 90 30 8 395.0 397.6 90 29 397.1 90 30 9 416.8 419.5 90 29 420.8 89 31[Table 2] a) Without compensation polarizing plate b) With compensation polarizing plate ─────────── ────────── Sample R 0 R φ 1 (°) φ 2 (°) R φ 1 (°) φ 2 (°) 1 152.5 153.0 89 30 152.0 89 31 2 218.7 219.7 89 29 218.7 90 29 3 241.2 238.7 90 29 246.0 89 31 4 271.9 260.6 90 30 273.1 89 31 5 362.3 364.7 89 31 363.8 90 30 6 382.9 385.1 89 30 385.9 90 30 7 413.4 415.1 90 29 417.1 90 30 8 395.0 397.6 90 29 397.1 90 30 9 416.8 419.5 90 29 420.8 89 31
【0047】表2の測定結果から、補償用偏光板を使用
しないときには、レターデーション値で4%程度までの
かなりの誤差があり、光学主軸方向では平均1度前後の
誤差を生じたのに対し、補償用偏光板を使用した場合に
は、レターデーション値の誤差は±1%以内であり、光
学主軸方向については平均0.3%と殆ど誤差を生じな
かった。従って、偏光子を使用していない場合には、偏
光子を使用した実験例1ほどには、補償板使用の有無に
よる差異が顕著ではなかったが、測定波長によってはこ
の差が顕著に現れる。偏光板Bに代えて偏光度が99.
9%の偏光板を使用して上記のa),b)と同様の測定
を行なった。その結果、a),b)両測定とも精度よく
レターデーション値及び光学主軸方向が測定できた。From the measurement results in Table 2, when the compensating polarizing plate was not used, there was a considerable error in the retardation value up to about 4%, and an error of about 1 degree occurred on average in the optical principal axis direction. When the compensating polarizing plate was used, the error in retardation value was within ± 1%, and there was almost no error in the direction of the optical principal axis, which was 0.3% on average. Therefore, in the case where the polarizer was not used, the difference due to the use or non-use of the compensating plate was not as remarkable as in Experimental Example 1 using the polarizer, but the difference was remarkable depending on the measurement wavelength. The polarization degree is 99.
The same measurement as the above a) and b) was performed using a 9% polarizing plate. As a result, the retardation value and the direction of the optical principal axis could be measured with high accuracy in both measurements a) and b).
【0048】[実験例3]図6A,Bは、実験例1、実
験例2に用いた補償用偏光板(偏光度99.9%)(偏
光板A)と、複合層の偏光板(偏光度95.0%)(偏
光板B)に対するそれぞれの分光透過特性を示し、図6
Aは偏光板Aに対して偏光子を直交ニコルに配置した場
合、図6Bは偏光板Bに対して偏光子を直交ニコルに配
置したときの分光透過率を示している。[Experimental Example 3] FIGS. 6A and 6B show a compensating polarizing plate (polarization degree 99.9%) (polarizing plate A) used in Experimental Examples 1 and 2 and a composite layer polarizing plate (polarizing plate). FIG. 6 shows the respective spectral transmission characteristics with respect to 95.0% (polarizing plate B).
6A shows the spectral transmittance when the polarizer is arranged in the crossed Nicols with respect to the polarizing plate A, and FIG. 6B shows the spectral transmittance when the polarizer is arranged in the crossed Nicols with respect to the polarizing plate B.
【0049】偏光板Aでは700nm以下の波長域では
透過光が検出されないのに対し、偏光板Bでは700n
m以下でも透過光が存在する。570〜640の範囲は
透過率1%前後と小さいが、400〜550nmの範囲
では数パーセントの透過率を生じている。偏光度95%
とは、例えば400〜800nmの波長領域における直
交ニコル配置での平均透過率が5%であることを示して
いる。In the polarizing plate A, transmitted light is not detected in the wavelength range of 700 nm or less, whereas in the polarizing plate B, 700 n
There is transmitted light even at m or less. The transmittance in the range of 570 to 640 is as small as around 1%, but the transmittance of several percent occurs in the range of 400 to 550 nm. Polarization degree 95%
Means, for example, that the average transmittance in the orthogonal Nicol arrangement in the wavelength region of 400 to 800 nm is 5%.
【0050】上記実験例1、実験例2における測定光波
長が590nmであるので、直交ニコルでの透過率が小
さいため、補償用偏光板を用いた場合と用いない場合と
の差が比較的小さいが、他の波長、たとえば500nm
の測定光を用いた場合には、両者の差が相当に大きくな
るものと推定される。したがって、補償用偏光板を用い
た本発明では、広い波長範囲にわたって、精確な測定が
行える効果があるものといえる。Since the measured light wavelength in Experimental Examples 1 and 2 is 590 nm, the transmittance in the crossed Nicols is small, and the difference between the case where the compensating polarizing plate is used and the case where it is not used is relatively small. But other wavelengths, eg 500 nm
It is estimated that the difference between the two is considerably large when the measurement light of 1 is used. Therefore, it can be said that the present invention using the compensating polarizing plate has an effect that accurate measurement can be performed over a wide wavelength range.
【0051】複合層試料の視野角特性を測定した例を説
明する。単体でのレターデーション値がそれぞれ393.8
nmと584.1nmである2種類の位相差フィルムA,B
の2つの光学主軸のうち、屈折率の大きい方の光学主軸
を傾斜軸として傾斜させて測定光束の入射角を異なら
せ、レターデーション値を測定した。An example of measuring the viewing angle characteristics of the composite layer sample will be described. Retardation value of 393.8 each
of two types of retardation films A and B of 1 nm and 584.1 nm
The retardation value was measured by tilting the optical axis having the larger refractive index of the two optical axes described above as the tilt axis to make the incident angle of the measurement light beam different.
【0052】また、その2種類の位相差フィルムに単体
での透過率が約44%の偏光フィルムを重ね合わせ、位
相差フィルムの光学主軸と偏光フィルムの偏光吸収軸と
のなす角を約35°とした複合シートも試料とした。複
合シート試料については、補償用偏光板を用い、偏光フ
ィルムと補償用偏光板の偏光透過軸を互いに平行に保っ
て偏光フィルタ層の偏光特性を補償した上で、位相差フ
ィルム単体の場合と同様に位相差フィルムの屈折率の大
きい方の光学主軸を傾斜軸として傾斜させ、測定光束の
入射角を異ならせてレターデーション値を測定した。こ
れらの結果を表3に示す。A polarizing film having a transmittance of about 44% by itself is superposed on the two types of retardation films, and the angle formed by the optical principal axis of the retardation film and the polarization absorption axis of the polarizing film is about 35 °. The composite sheet was also used as a sample. For the composite sheet sample, the same as in the case of the retardation film alone after using the compensating polarizing plate and compensating the polarization characteristics of the polarizing filter layer by keeping the polarization transmission axes of the polarizing film and the compensating polarizing plate parallel to each other. The retardation value was measured by tilting the optical axis of the retardation film having the larger refractive index as the tilt axis and changing the incident angle of the measurement light beam. Table 3 shows the results.
【0053】[0053]
【表3】 位相差フィルムA 位相差フィルムB 入射角 単体 重ね合わせ 単体 重ね合わせ ─── ───────── ────────── 0° 393.8nm 394.1nm 584.1nm 587.9nm 10° 399.2 399.2 587.7 591.2 20° 413.1 414.1 599.1 603.5 30° 435.1 438.0 612.2 617.5 40° 464.4 467.6 639.8 618.3 [Table 3] Retardation film A Retardation film B Incident angle Single layer Single layer Single layer Overlap ─── ─────────────────── 0 ° 393.8nm 394.1nm 584.1nm 587.9nm 10 ° 399.2 399.2 587.7 591.2 20 ° 413.1 414.1 599.1 603.5 30 ° 435.1 438.0 612.2 617.5 40 ° 464.4 467.6 639.8 618.3
【0054】表3の結果から、複合シートとした場合も
位相差フィルム単体の場合とほぼ一致したレターデーシ
ョン値を示しており、光学フィルムの貼り合わせ品につ
いても視野角特性を評価できることがわかる。その結
果、本発明は光学フィルムの貼り合わせ加工メーカーで
の出荷検査やパネルメーカーでの受入れ検査に利用する
ことができ、貼り合わせ品の品質の安定化に寄与するこ
とができる。From the results shown in Table 3, the retardation value of the composite sheet is almost the same as that of the retardation film alone, and it can be seen that the viewing angle characteristics of the laminated optical film can be evaluated. As a result, the present invention can be used for shipping inspections by optical film laminating makers and acceptance inspections by panel makers, and can contribute to stabilizing the quality of laminated products.
【0055】[0055]
1)本発明は、偏光フィルタ層と複屈折性層を積層した
複合層試料の偏光フィルタ層側に偏光フィルタ層よりも
偏光特性の優れた補償用偏光板を配置し、かつ偏光フィ
ルタ層と補償用偏光板の偏光透過軸を互いに平行に保っ
て偏光フィルタ層の偏光特性を補償するようにしたの
で、偏光フィルタ層として偏光度の高くない材料を使用
した場合にも、比較的広い波長範囲にわたって、充分な
精度で、複屈折性層のレターデーション値と光学主軸方
向を測定することが可能となった。しがって、また複屈
折測定装置の適用範囲の拡大、液晶表示板の製造コスト
の低減にも役立つものである。1) According to the present invention, a compensating polarizing plate having polarization characteristics superior to those of a polarizing filter layer is arranged on the polarizing filter layer side of a composite layer sample in which a polarizing filter layer and a birefringent layer are laminated, and the polarizing filter layer and the compensating polarizing plate are compensated. Since the polarization transmission axes of the polarizing plates for use are kept parallel to each other to compensate for the polarization characteristics of the polarizing filter layer, even when a material with a low degree of polarization is used for the polarizing filter layer, it covers a relatively wide wavelength range. The retardation value of the birefringent layer and the optical principal axis direction can be measured with sufficient accuracy. Therefore, it is also useful for expanding the application range of the birefringence measuring device and reducing the manufacturing cost of the liquid crystal display panel.
【0056】2)簡単な装置構成で、かつ補償用偏光板
を使用し、検光子を回転させ、又は偏光子と検光子を回
転させて透過光強度を測定するという簡単な操作で、複
屈折性層のレターデーション値と光学主軸方向の測定を
行うことができる。したがって、また製造現場のオンラ
イン測定による工程管理、完成品の品質管理いずれにも
役立てられる。 3)装置構成の部分的変更または切り替えにより、通常
の複屈折試料のレターデーション測定と複合層試料のレ
ターデーション測定との選択を行うことができる。 4)また、偏光フィルタ層として偏光度の高くない材料
を使用した複合層試料であっても、視野角特性をレター
デーション値として評価することができ、貼り合わせ品
の品質の安定化を図ることができる。2) Birefringence can be obtained by a simple device construction and by using a compensating polarizing plate and rotating the analyzer or rotating the polarizer and the analyzer to measure the transmitted light intensity. It is possible to measure the retardation value of the functional layer and the optical axis direction. Therefore, it is also useful for both process control by online measurement at the manufacturing site and quality control of finished products. 3) It is possible to select between ordinary retardation measurement of a birefringent sample and retardation measurement of a composite layer sample by partially changing or switching the device configuration. 4) In addition, even for a composite layer sample using a material having a low degree of polarization as the polarization filter layer, the viewing angle characteristics can be evaluated as a retardation value, and the quality of the bonded product can be stabilized. You can
【図1】 本発明の一実施例装置の概略構成図である。FIG. 1 is a schematic configuration diagram of an apparatus according to an embodiment of the present invention.
【図2】 本発明の原理説明用図である。FIG. 2 is a diagram for explaining the principle of the present invention.
【図3】 本発明における透過光強度の極座標表示によ
るグラフの一例図である。FIG. 3 is an example of a graph of transmitted light intensity in polar coordinate display according to the present invention.
【図4】 他の実施例における試料台を示す概略斜視図
である。FIG. 4 is a schematic perspective view showing a sample table in another embodiment.
【図5】 同試料台を詳細に示す分解斜視図である。FIG. 5 is an exploded perspective view showing the sample table in detail.
【図6】 偏光フィルタの分光透過特性を示すスペクト
ル図であり、(A)は偏光度の高い偏光フィルタ、
(B)は偏光度の低い偏光フィルタの例である。FIG. 6 is a spectrum diagram showing a spectral transmission characteristic of a polarization filter, where (A) is a polarization filter with a high degree of polarization,
(B) is an example of a polarizing filter having a low degree of polarization.
1 白色光源 2 オプチカルファイバー 3 集光レンズ 4 狭帯域干渉フィルタ 5 偏光子前進、後退用Xステージ 6 偏光子回転用θステージ 7 偏光子回転位置決め用エンコーダ 8 偏光子 9 補償用偏光板 10 補償用偏光板回転用θステージ 11,11a 試料台 12 検光子前進、後退用Xステージ 13 検光子回転用θステージ 14 検光子回転位置決め用エンコーダ 15 検光子 16 受光素子 17 制御装置 18 表示装置 19 補償用偏光板回転用θステージ用モータ 20 偏光子回転用θステージ用モータ 21 検光子回転用θステージ用モータ 1 White Light Source 2 Optical Fiber 3 Condenser Lens 4 Narrow Band Interference Filter 5 Polarizer Forward / Reverse X Stage 6 Polarizer Rotation θ Stage 7 Polarizer Rotation Positioning Encoder 8 Polarizer 9 Compensating Polarizing Plate 10 Compensating Polarizing Plate Plate rotation θ stage 11, 11a Sample stage 12 Analyzer forward / backward X stage 13 Analyzer rotation θ stage 14 Analyzer rotation positioning encoder 15 Analyzer 16 Light receiving element 17 Control device 18 Display device 19 Compensation polarizing plate Rotation θ-stage motor 20 Polarizer rotation θ-stage motor 21 Analyzer rotation θ-stage motor
Claims (7)
複合層試料の偏光フィルタ層側に補償用偏光板を配置
し、かつ偏光フィルタ層と補償用偏光板の偏光透過軸を
互いに平行に保って偏光フィルタ層の偏光特性を補償す
る工程と、 前記補償用偏光板側から測定光を照射し、補償用偏光板
及び複合層試料を透過した透過光を検光子に通し、その
検光子の偏光透過軸を補償用偏光板及び複合層試料の偏
光透過軸に対して相対的に回転させて、検光子透過光の
強度と検光子の偏光方位との関係を検出して複合層試料
のレターデーション及び光学主軸方向を求める工程と、
を備えたことを特徴とする複合層のレターデーション測
定方法。1. A compensating polarizing plate is disposed on the polarizing filter layer side of a composite layer sample in which a polarizing filter layer and a birefringent layer are laminated, and the polarizing transmission axes of the polarizing filter layer and the compensating polarizing plate are parallel to each other. The step of maintaining the polarization characteristics of the polarizing filter layer and compensating, irradiating the measuring light from the side of the polarizing plate for compensation, passing the transmitted light passing through the polarizing plate for compensation and the composite layer sample to the analyzer, The polarization transmission axis is rotated relative to the polarization transmission axis of the compensating polarizing plate and the composite layer sample, and the relationship between the intensity of the analyzer transmitted light and the polarization direction of the analyzer is detected to detect the letter of the composite layer sample. And the step of obtaining the optical axis direction of the optical axis,
A method for measuring retardation of a composite layer, comprising:
板に照射される請求項1に記載の複合層のレターデーシ
ョン測定方法。2. The retardation measuring method for a composite layer according to claim 1, wherein the measuring light is applied to the compensation polarizing plate in a non-polarized state.
配置し、その偏光子と前記検光子とを互いに所定の偏光
方位関係に保つ請求項1に記載の複合層のレターデーシ
ョン測定方法。3. The retardation measurement of the composite layer according to claim 1, wherein a polarizer is arranged on the light incident side of the compensation polarizing plate, and the polarizer and the analyzer are kept in a predetermined polarization azimuth relationship with each other. Method.
状態で、補償用偏光板を前記偏光フィルタ層に対して相
対的に一回転させながら透過光強度を測定し、偏光フィ
ルタ層の偏光透過軸と補償用偏光板の偏光透過軸とを平
行位にする請求項1に記載の複合層のレターデーション
測定方法。4. The transmitted light intensity is measured while rotating the compensating polarizing plate once relative to the polarizing filter layer in a state where neither a polarizer nor an analyzer is arranged in the optical path, The method for measuring retardation of a composite layer according to claim 1, wherein the polarization transmission axis and the polarization transmission axis of the compensating polarizing plate are parallel to each other.
垂直状態に配置して複合層試料のレターデーション及び
光学主軸方向を求めた後、 求められた2つの光学主軸方向のうちのいずれかを傾斜
軸として複合層試料の面を傾斜させた状態で、再び検光
子の偏光透過軸を複合層試料の偏光透過軸に対して相対
的に回転させて、検光子透過光の強度と検光子の偏光方
位との関係を検出して複合層試料のレターデーションを
求める工程をさらに含んでいる請求項4に記載の複合層
のレターデーション測定方法。5. The retardation and the optical principal axis direction of the composite layer sample are determined by arranging the surface of the composite layer sample in a state perpendicular to the optical path of the measuring light, and then, of the two determined optical principal axis directions. While tilting the surface of the composite layer sample with one of them as the tilt axis, the polarization transmission axis of the analyzer is again rotated relative to the polarization transmission axis of the composite layer sample, and the intensity of the analyzer transmitted light is The method for measuring the retardation of a composite layer according to claim 4, further comprising the step of determining the retardation of the composite layer sample by detecting the relationship with the polarization direction of the analyzer.
層試料を保持する試料台と、 試料台に保持された複合層試料の測定光束出射側に配置
され回転可能に支持された検光子と、 試料台に保持された複合層試料の測定光束入射側に設け
られ、検光子とは独立に回転可能に支持され、複合層試
料の偏光フィルタ層の偏光特性を補償する補償用偏光板
と、 補償用偏光板から複合層試料を経て検光子を透過した光
の透過光強度を検出する受光部と、 検光子の回転角度と受光部が検出した透過光強度とから
複合層試料のレターデーション及び光学主軸方向を算出
する演算制御装置とを備えたことを特徴とする複合層の
レターデーション測定装置。6. A light source section for irradiating a measurement light beam on a measurement optical path, a sample stage for holding a composite layer sample in which a polarization filter layer and a birefringent layer are laminated on the measurement optical path, and a composite layer sample held on the sample stage. The rotatably supported analyzer placed on the measurement light flux exit side of the sample, and the composite layer held on the sample stage, provided on the measurement light flux entrance side of the sample and rotatably supported independently of the analyzer. The compensating polarizing plate that compensates the polarization characteristics of the polarizing filter layer of the sample, the light receiving part that detects the transmitted light intensity of the light that has passed through the analyzer from the compensating polarizing plate through the composite layer sample, and the rotation angle of the analyzer. A retardation measuring device for a composite layer, comprising: an arithmetic and control unit for calculating the retardation of the composite layer sample and the optical principal axis direction from the transmitted light intensity detected by the light receiving section.
面内で回転させる機構と、その複合層試料の表面に沿っ
た一直線を中心としてその複合層試料を傾斜させる傾斜
機構とを備えている請求項6に記載の複合層のレタデー
ション測定装置。7. The sample stage comprises a mechanism for rotating the held composite layer sample in its plane and an inclining mechanism for inclining the composite layer sample about a straight line along the surface of the composite layer sample. 7. The retardation measuring device for a composite layer according to claim 6.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP26945095A JP3539006B2 (en) | 1994-09-30 | 1995-09-22 | Method and apparatus for measuring retardation of composite layer |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP23826394 | 1994-09-30 | ||
JP6-238263 | 1994-09-30 | ||
JP26945095A JP3539006B2 (en) | 1994-09-30 | 1995-09-22 | Method and apparatus for measuring retardation of composite layer |
Publications (2)
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JPH08152399A true JPH08152399A (en) | 1996-06-11 |
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Family
ID=26533613
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JP26945095A Expired - Fee Related JP3539006B2 (en) | 1994-09-30 | 1995-09-22 | Method and apparatus for measuring retardation of composite layer |
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Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2007329251A (en) * | 2006-06-07 | 2007-12-20 | Fujitsu Ltd | Optical wafer inspection device |
JP2014167392A (en) * | 2013-02-28 | 2014-09-11 | Oji Holdings Corp | Phase difference measuring method and device |
WO2019044527A1 (en) * | 2017-08-30 | 2019-03-07 | ソニー株式会社 | Observation device, observation method, and program |
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JP4926003B2 (en) * | 2007-11-12 | 2012-05-09 | 王子計測機器株式会社 | Polarization analysis method |
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1995
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Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2007329251A (en) * | 2006-06-07 | 2007-12-20 | Fujitsu Ltd | Optical wafer inspection device |
JP2014167392A (en) * | 2013-02-28 | 2014-09-11 | Oji Holdings Corp | Phase difference measuring method and device |
WO2019044527A1 (en) * | 2017-08-30 | 2019-03-07 | ソニー株式会社 | Observation device, observation method, and program |
JPWO2019044527A1 (en) * | 2017-08-30 | 2020-10-15 | ソニー株式会社 | Observation device, observation method, and program |
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