JP2010085990A - Wire grid polarizing plate - Google Patents
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本発明は、ワイヤグリッド偏光板に関する。 The present invention relates to a wire grid polarizer.
近年のフォトリソグラフィー技術の発達により、光の波長レベルのピッチを有する微細構造パターンを形成することができるようになってきた。このように非常に狭いピッチのパターンを有する部材や製品は、半導体分野だけでなく、光学分野において利用範囲が広く有用である。 With the recent development of photolithography technology, it has become possible to form a fine structure pattern having a pitch at the wavelength level of light. Such a member or product having a pattern with a very narrow pitch is useful not only in the semiconductor field but also in the optical field.
例えば、基板上に金属などの導電体線が特定のピッチで格子状に配列したワイヤグリッドは、そのピッチが入射光（例えば、可視光の波長４００ｎｍから８００ｎｍ）に比べてかなり小さい場合（例えば、２分の１以下）であれば、導電体線に対して平行に振動する電場ベクトル成分をほとんど反射し、垂直な電場ベクトル成分をほとんど透過させるため、単一偏光を作り出すワイヤグリッド偏光板として使用できる。このようなワイヤグリッド偏光板は、透過しない光を反射して再利用することができるので、光の有効利用の観点からも望ましいものである。 For example, a wire grid in which conductor wires such as metal are arranged in a lattice pattern at a specific pitch on a substrate has a considerably smaller pitch than incident light (for example, a visible light wavelength of 400 nm to 800 nm) (for example, If it is less than half), it reflects almost all electric field vector components that oscillate in parallel to the conductor line and almost transmits perpendicular electric field vector components. it can. Such a wire grid polarizing plate is desirable from the viewpoint of effective use of light because it can reflect and reuse light that does not pass through.
近年、小さなピッチの微細凹凸格子を有するワイヤグリッド偏光子が開発されている（特許文献１）。このワイヤグリッド偏光子は、図５に示すように、ガラス基板１０１の格子状凸部１０１ａ上に、誘電体膜１０２を介して導電素子１０３が形成された構成となっている。このワイヤグリッド偏光子は、ガラス基板１０１の基台部Ｘの屈折率よりも、格子状凸部１０１ａと誘電体膜１０２とを合わせた厚さの領域Ｙの屈折率が低く設定されている。このような構成にすることにより、光の透過、反射特性が急激に変化する共鳴現象の起きる共鳴ポイントを短波長側へシフトさせ、透過と反射の効率を高くすることができる。 In recent years, a wire grid polarizer having a fine concavo-convex grating with a small pitch has been developed (Patent Document 1). As shown in FIG. 5, the wire grid polarizer has a configuration in which a conductive element 103 is formed on a grid-like convex portion 101 a of a glass substrate 101 via a dielectric film 102. In this wire grid polarizer, the refractive index of the region Y having a thickness obtained by combining the lattice-shaped convex portions 101 a and the dielectric film 102 is set lower than the refractive index of the base portion X of the glass substrate 101. By adopting such a configuration, the resonance point where the resonance phenomenon in which the light transmission and reflection characteristics change abruptly is shifted to the short wavelength side, and the efficiency of transmission and reflection can be increased.
しかしながら、上述したワイヤグリッド偏光子は、ガラス基板１０１の格子状凸部１０１ａの頂部上に導電素子１０３が設けられており、このような構成においては、可視光領域において光の波長により透過率が変化する、すなわち透過率の波長依存性があるという問題がある。 However, in the wire grid polarizer described above, the conductive element 103 is provided on the top of the lattice-like convex portion 101a of the glass substrate 101, and in such a configuration, the transmittance varies depending on the wavelength of light in the visible light region. There is a problem of changing, that is, there is wavelength dependency of transmittance.
本発明はかかる点に鑑みてなされたものであり、可視光領域の広帯域にわたって波長依存性が無く、優れた偏光度と透過率を両立するワイヤグリッド偏光板を提供することを目的とする。 This invention is made | formed in view of this point, and it aims at providing the wire grid polarizing plate which does not have wavelength dependence over the broadband of visible region, and is compatible in the outstanding polarization degree and the transmittance | permeability.
本発明のワイヤグリッド偏光板は、特定方向に延在する格子状凸部を有し、特定方向に垂直な断面における格子状凸部間の凹部の形状が略放物線形状である凹凸格子を持つ樹脂基材と、格子状凸部上に被覆された誘電体層と、誘電体層上に設けられた金属ワイヤと、を具備し、金属ワイヤが誘電体被覆格子状凸部の頂部より少なくとも上方に存在し、特定方向に垂直な断面において金属ワイヤの頂部を通り金属ワイヤの立設方向に沿う金属ワイヤ軸と、誘電体被覆格子状凸部の頂部を通り誘電体被覆格子状凸部の立設方向に沿う格子状凸部軸と、がずれていることを特徴とする。 The wire grid polarizing plate of the present invention is a resin having a concavo-convex lattice having a lattice-shaped convex portion extending in a specific direction, and a shape of a concave portion between the lattice-shaped convex portions in a cross section perpendicular to the specific direction being a substantially parabolic shape. A base material; a dielectric layer coated on the grid-shaped convex portion; and a metal wire provided on the dielectric layer, wherein the metal wire is at least above the top of the dielectric-coated grid-shaped convex portion. In a cross section that exists and is perpendicular to a specific direction, passes through the top of the metal wire and extends along the standing direction of the metal wire, and passes through the top of the dielectric-covered grid-like convex part, and the dielectric-covered grid-like convex part stands The grid-like convex axis along the direction is shifted.
本発明のワイヤグリッド偏光板においては、金属ワイヤが誘電体被覆格子状凸部の一方の側面上方にかけて形成されていることが好ましい。 In the wire grid polarizing plate of the present invention, it is preferable that the metal wire is formed over one side surface of the dielectric-coated grid-like convex portion.
本発明のワイヤグリッド偏光板においては、金属ワイヤ軸と格子状凸部軸との間のずれ量ＤがワイヤピッチＰの０．３倍以下であることが好ましい。 In the wire grid polarizing plate of the present invention, it is preferable that the amount of deviation D between the metal wire axis and the grid-like convex axis is not more than 0.3 times the wire pitch P.
本発明のワイヤグリッド偏光板においては、誘電体被覆格子状凸部の底部から３分の２の高さにおける幅ＷＨが、底部から３分の１の高さにおける誘電体被覆格子状凸部の幅ＷＬの０．３倍〜０．９倍であり、底部から２分の１の高さにおける幅ＷＭがワイヤピッチＰの０．１倍〜０．５倍であり、誘電体被覆格子状凸部の底部から頂部までの高さＨ２がワイヤピッチＰの０．５倍〜１．５倍であることが好ましい。 In the wire grid polarizing plate of the present invention, the width WH at the height of two-thirds from the bottom of the dielectric-coated grid-shaped convex portion is equal to the width of the dielectric-coated grid-shaped convex portion at the height of one-third from the bottom. The width WL is 0.3 times to 0.9 times the width WL, and the width WM at a half height from the bottom is 0.1 times to 0.5 times the wire pitch P. height from the bottom portion of the part to the top part H 2 is preferably a 0.5 to 1.5 times the wire pitch P.
本発明のワイヤグリッド偏光板においては、誘電体被覆格子状凸部の頂部高さにおける金属ワイヤの幅ｔがワイヤピッチＰの０．３倍〜０．７倍で、金属ワイヤの幅がほぼｔを最大値として底部と頂部の端部に向かって減少する形状あり、金属ワイヤの底部から頂部までの高さＨ３が誘電体被覆格子状凸部の底部から金属ワイヤ頂部までの高さＨ１の０．８倍〜1倍であり、誘電体被覆格子状凸部の底部から頂部までの高さＨ２が誘電体被覆格子状凸部の底部から金属ワイヤ頂部までの高さＨ１の０．５倍〜０．９倍であることが好ましい。 In the wire grid polarizing plate of the present invention, the width t of the metal wire at the top height of the dielectric-coated grid-shaped convex portion is 0.3 to 0.7 times the wire pitch P, and the width of the metal wire is approximately t. , And the height H 3 from the bottom to the top of the metal wire is the height H 1 from the bottom of the dielectric-coated grid-like convex portion to the top of the metal wire. 0 0.8 a to 1-fold, from the bottom of the dielectric coating the grid-shaped convex portion height H 2 of to the top part from the bottom of the dielectric coating the grid-shaped convex portion to the metal wire top of the height H 1 It is preferably 5 to 0.9 times.
本発明のワイヤグリッド偏光板においては、ワイヤピッチＰが８０ｎｍ〜３００ｎｍであることが好ましい。 In the wire grid polarizing plate of the present invention, the wire pitch P is preferably 80 nm to 300 nm.
本発明のワイヤグリッド偏光板においては、波長がワイヤピッチＰの３倍〜２０００ｎｍの光に対し、偏光度９５以上、透過率３５％以上の偏光性能を有することが好ましい。 The wire grid polarizing plate of the present invention preferably has a polarization performance with a polarization degree of 95 or more and a transmittance of 35% or more for light having a wavelength of 3 to 2000 nm of the wire pitch P.
本発明のワイヤグリッド偏光板においては、前記誘電体層を構成する誘電体が酸化ケイ素又は窒化ケイ素であることが好ましい。 In the wire grid polarizing plate of the present invention, it is preferable that the dielectric constituting the dielectric layer is silicon oxide or silicon nitride.
本発明のワイヤグリッド偏光板においては、前記金属ワイヤが、アルミニウム又は銀もしくはそれらの合金で構成されていることが好ましい。 In the wire grid polarizing plate of the present invention, it is preferable that the metal wire is made of aluminum, silver, or an alloy thereof.
本発明のワイヤグリッド偏光板においては、横断面視において金属ワイヤ面側への垂直方向から金属ワイヤが形成されていない側へ入射角を４５°ずらしたＰ波透過率Ｔｐが、８０％以上であることが好ましい。 In the wire grid polarizing plate of the present invention, the P-wave transmittance Tp with the incident angle shifted by 45 ° from the direction perpendicular to the metal wire surface side to the side where the metal wire is not formed in a cross-sectional view is 80% or more. Preferably there is.
本発明のワイヤグリッド偏光板においては、Ｓ波透過率Ｔｓが、０．５％以下であることが好ましい。 In the wire grid polarizing plate of the present invention, the S wave transmittance Ts is preferably 0.5% or less.
本発明のワイヤグリッド偏光板によれば、特定方向に延在する格子状凸部を有し、特定方向に垂直な断面における格子状凸部間の凹部の形状が略放物線形状である凹凸格子を持つ樹脂基材と、格子状凸部上に被覆された誘電体層と、誘電体層上に設けられた金属ワイヤと、を具備し、金属ワイヤが誘電体被覆格子状凸部の頂部より少なくとも上方に存在し、誘電体被覆格子状凸部の頂部高さにおける金属ワイヤの幅をほぼ最大値として底部と頂部の端部に向かって減少する形状であり、特定方向に垂直な断面において金属ワイヤの頂部を通り金属ワイヤの立設方向に沿う金属ワイヤ軸と、誘電体被覆格子状凸部の頂部を通り誘電体被覆格子状凸部の立設方向に沿う格子状凸部軸とがずれている構造を有することにより、可視光領域の広帯域にわたって波長依存性が無く、優れた偏光度及び透過率を両立することができる。 According to the wire grid polarizing plate of the present invention, the concavo-convex lattice having a lattice-shaped convex portion extending in a specific direction, and the shape of the concave portion between the lattice-shaped convex portions in a cross section perpendicular to the specific direction is a substantially parabolic shape. A resin base material, a dielectric layer coated on the lattice-shaped convex portion, and a metal wire provided on the dielectric layer, the metal wire being at least from the top of the dielectric-coated lattice-shaped convex portion The metal wire has a shape that exists upward and decreases toward the bottom and the end of the top with the width of the metal wire at the top height of the dielectric-covered grid-like convex portion being almost the maximum value, and in a cross section perpendicular to a specific direction. The metal wire axis that passes through the top of the metal wire along the standing direction of the metal wire and the grid-like convex axis that passes through the top of the dielectric-coated grid-like convex part and runs along the standing direction of the dielectric-coated grid-like convex part are shifted. Has a wide bandwidth in the visible light region. Tatte without wavelength dependency, it is possible to achieve both excellent degree of polarization and transmittance.
以下、本発明の実施の形態について、添付図面を参照して詳細に説明する。
図１は、本発明の実施の形態に係るワイヤグリッド偏光板の一部を示す概略断面図である。図１に示すワイヤグリッド偏光板は、格子状凸部を有する樹脂基材１（以下、樹脂基材１ともいう）と、前記樹脂基材の格子状凸部１ａ（以下、凸部１ａともいう）及びその側面１ｃの少なくとも一部を覆うように設けられた誘電体層２と、前記誘電体層２上に設けられた金属ワイヤ３とから主に構成されている。可視光から近赤外光に対して高い偏光性能（偏光度、透過率）のワイヤグリッド偏光板を作るには、ワイヤピッチＰを一定（８０ｎｍ〜３００ｎｍ）とした場合、ワイヤ幅をワイヤピッチの０．３倍〜０．６倍程度として、ワイヤ高さを１２０ｎｍ〜２５０ｎｍの範囲で比較的高くすることが好ましい。また、金属ワイヤの周囲の屈折率は、できるだけ低い方が好ましい。
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic cross-sectional view showing a part of a wire grid polarizer according to an embodiment of the present invention. The wire grid polarizing plate shown in FIG. 1 has a resin base material 1 (hereinafter also referred to as a resin base material 1) having a grid-like convex portion and a grid-like convex portion 1a (hereinafter also referred to as a convex portion 1a) of the resin base material. ) And a dielectric layer 2 provided so as to cover at least part of the side surface 1c, and a metal wire 3 provided on the dielectric layer 2. To make a wire grid polarizer with high polarization performance (polarization degree, transmittance) from visible light to near infrared light, when the wire pitch P is constant (80 nm to 300 nm), the wire width is set to the wire pitch. It is preferable that the wire height be relatively high in the range of 120 nm to 250 nm, such as about 0.3 to 0.6 times. The refractive index around the metal wire is preferably as low as possible.
このようなワイヤグリッド偏光板において、樹脂基材１は、格子状凸部１ａが延在する特定方向に垂直な断面における前記格子状凸部１ａ間の凹部１ｂの形状が略放物線形状である凹凸格子を持ち、誘電体層２で被覆された格子状凸部（誘電体被覆格子状凸部）１ａは上方に向かって先細り形状となっている。格子状凸部間の凹部の形状が略放物線形状であることにより、形状転写時の離型性が良好で、金型の表面が凹部を形成する略放物線形状となるために、金型としても接触によるパターンの変形に強いものとなる。 In such a wire grid polarizing plate, the resin base material 1 has irregularities in which the shape of the concave portion 1b between the lattice-like convex portions 1a in a cross section perpendicular to the specific direction in which the lattice-like convex portions 1a extend is substantially parabolic. A lattice-like convex portion (dielectric-covered lattice-like convex portion) 1 a having a lattice and covered with the dielectric layer 2 is tapered toward the upper side. Since the shape of the recesses between the grid-like convex portions is a substantially parabolic shape, the mold releasability at the time of shape transfer is good, and the surface of the mold becomes a substantially parabolic shape that forms the concave portions. It is resistant to deformation of the pattern due to contact.
また、図８のように、格子状凸部間の凹部の形状が、凹部側にくびれた略放物線形状であってもよい。この形状であると、形状転写時の離型性が良好で、金型の表面が凹部を形成する略放物線形状となるために、金型としても接触によるパターンの変形に強いものとなるばかりでなく、金属ワイヤの幅ｔがＨ３の高さ方向に安定して確保できる。これにより、角度依存性が少ない等、光学特性に優れるワイヤグリッド偏光板を得ることができる。 Further, as shown in FIG. 8, the shape of the recesses between the grid-like convex portions may be a substantially parabolic shape constricted toward the concave portions. With this shape, the mold releasability at the time of shape transfer is good, and since the surface of the mold has a substantially parabolic shape that forms a recess, the mold is not only resistant to deformation of the pattern due to contact. without the width t of the metal wire can be stably ensured in the height direction of the H 3. Thereby, the wire grid polarizing plate which is excellent in optical characteristics, such as little angle dependence, can be obtained.
また、金属ワイヤ３は、誘電体層２で被覆された格子状凸部１ａの頂部より少なくとも上方に存在している。これは、金属ワイヤ３の周囲の屈折率を低減して光学性能を向上させるためには、誘電体被覆凸部との結合部を除き、屈折率が１である周囲の空間とすることが好ましく、必要な誘電体被覆凸部との結合力を確保しながら、金属ワイヤ３を誘電体被覆凸部の頂部よりもできるだけ上方の空間に形成させることが好ましいからである。ここで、頂部とは、立設方向の最大高さ部分であり、最大高さの部分に平坦領域がある場合は平坦部分の中央部である。また、前記断面において金属ワイヤ３の頂部を通り、金属ワイヤ３の立設方向に沿う金属ワイヤ軸Ａと、前記断面において格子状凸部１ａの頂部を通り、格子状凸部１ａの立設方向に沿う格子状凸部軸Ｂとがずれている。このように金属ワイヤ３が、上方に向かって先細り形状の誘電体層２で被覆された格子状凸部１ａの一方の側面上方にかけて、金属ワイヤ軸と、格子状凸部軸とがずれて配設されていることにより、誘電体被覆凸部の一方の側面にできるだけ広い面積を使用して結合するので、比較的高さの高い金属ワイヤであっても基材に強固に固定することが可能となり、光学特性としても偏光度や透過率の波長依存性を小さくすることができる。 Further, the metal wire 3 exists at least above the top of the lattice-shaped convex portion 1 a covered with the dielectric layer 2. In order to reduce the refractive index around the metal wire 3 and improve the optical performance, it is preferable to make the surrounding space where the refractive index is 1, excluding the coupling portion with the dielectric coating convex portion. This is because it is preferable to form the metal wire 3 in a space as high as possible above the top of the dielectric covering convex portion while ensuring the necessary bonding force with the dielectric covering convex portion. Here, the top portion is the maximum height portion in the standing direction, and when there is a flat region in the maximum height portion, it is the central portion of the flat portion. Further, the metal wire axis A along the standing direction of the metal wire 3 through the top of the metal wire 3 in the cross section, and the standing direction of the grid-shaped convex 1a through the top of the grid-like convex 1a in the cross section. Is shifted from the grid-like convex axis B along the line. In this way, the metal wire axis and the grid-like convex axis are shifted from each other over the one side surface of the grid-like convex part 1a covered with the tapered dielectric layer 2 in the upward direction. Because it is connected to one side of the dielectric coated convex part using as wide an area as possible, even a relatively high metal wire can be firmly fixed to the substrate Therefore, the wavelength dependence of the degree of polarization and the transmittance can be reduced as optical characteristics.
金属ワイヤ軸Ａと格子状凸部軸Ｂとの間のずれ量Ｄは、高さの高い金属ワイヤであっても基材に強固に固定することや適切な金属ワイヤの幅を考慮すると、ワイヤピッチＰの０．３倍以下であることが好ましい。金属ワイヤ軸Ａと格子状凸部軸Ｂとの間のずれ量Ｄは、金属ワイヤ３と格子状凸部１ａの幅と先端位置によって決まるが、金属ワイヤ３を誘電体被覆凸部の一方の側面に結合した場合、金属ワイヤ３を誘電体被覆凸部に十分な結合力で結合するためには、ずれ量Ｄは小さい方が好ましく、ワイヤピッチＰの０．３倍以下が現実的である。 The amount of deviation D between the metal wire axis A and the grid-like convex axis B is determined by considering the fact that it is firmly fixed to the substrate even when the metal wire is high in height and the width of the appropriate metal wire is taken into consideration. The pitch P is preferably 0.3 times or less of the pitch P. The amount of deviation D between the metal wire axis A and the grid-like convex part axis B is determined by the width and the tip position of the metal wire 3 and the grid-like convex part 1a. In the case of bonding to the side surface, in order to bond the metal wire 3 to the dielectric-covered convex portion with a sufficient bonding force, it is preferable that the shift amount D is small, and it is practical that the wire pitch P is 0.3 times or less. .
本発明のワイヤピッチＰは、可視光〜赤外領域の広帯域にわたる偏光特性を考慮すると、８０ｎｍ〜３００ｎｍであり、使用する波長と必要な偏光特性にあわせて選択すれば良い。高い偏光性能を得るにはワイヤピッチＰは小さい方が好ましいが、一定の偏光度を維持するには金属ワイヤの高さＨ３には下限値が存在し、むやみにワイヤピッチＰを小さくすると、ワイヤの断面形状が高さに対し幅が非常に小さな形になり製作が難しくなる。通常、適用する光の最低波長の１／４〜１／３程度をワイヤピッチＰに設定することが好ましく、要求される偏光性能により適宜選定する。可視光に対しては８０ｎｍ〜１５０ｎｍのピッチで十分な偏光特性が得られる。また、主に、近赤外線以上の長波長光で用いる場合は、ピッチＰを３００ｎｍ程度まで大きくすることもできる。なお、本発明において、ワイヤピッチＰと、誘電体層２のピッチと、金属ワイヤ３のピッチとは、本発明のワイヤグリッドのピッチとほぼ等しい。 The wire pitch P of the present invention is 80 nm to 300 nm in consideration of polarization characteristics over a wide band from visible light to infrared region, and may be selected according to the wavelength to be used and the necessary polarization characteristics. Although high polarization wire pitch performance obtain P is preferably small and to maintain a constant degree of polarization exists a lower limit in the height H 3 of the metal wire, unduly reduce the wire pitch P, The cross-sectional shape of the wire becomes very small with respect to the height, making it difficult to manufacture. Usually, it is preferable to set the wire pitch P to about ¼ to ３ of the minimum wavelength of light to be applied, and it is appropriately selected depending on the required polarization performance. For visible light, sufficient polarization characteristics can be obtained at a pitch of 80 nm to 150 nm. Moreover, when using mainly the long wavelength light beyond near infrared rays, the pitch P can also be enlarged to about 300 nm. In the present invention, the wire pitch P, the pitch of the dielectric layer 2, and the pitch of the metal wires 3 are substantially equal to the pitch of the wire grid of the present invention.
また、金属ワイヤ３の高さ（金属ワイヤ３の立設方向における最長の距離）を１００％としたときの５％〜６０％が、誘電体凸部頂部よりも高い、言い換えると、金属ワイヤ３の高さの４０％〜９５％が凸部側面と接合していることが好ましい。また、金属ワイヤ３の頂部及び／又は底部の断面形状が先細り形状であることが好ましい。これにより、光学性能を保持しながら高さが高い金属ワイヤでも基材に強固に固定することができる。 Further, 5% to 60% when the height of the metal wire 3 (the longest distance in the standing direction of the metal wire 3) is 100% is higher than the top of the dielectric convex portion, in other words, the metal wire 3 40% to 95% of the height is preferably bonded to the side surface of the convex portion. Moreover, it is preferable that the cross-sectional shape of the top part and / or the bottom part of the metal wire 3 is a tapered shape. Thereby, a metal wire having a high height can be firmly fixed to the substrate while maintaining optical performance.
格子状凸部１ａの断面形状に制限はない。例えば、これらの断面形状は、台形、矩形、方形、プリズム状や、半円状などの正弦波状であってもよい。ここで、正弦波状とは凹部と凸部の繰り返しからなる曲線部をもつことを意味する。なお、曲線部は湾曲した曲線であればよく、例えば、凸部にくびれがある形状も正弦波状に含める。前記樹脂基材１の格子状凸部１ａ及びその側面の少なくとも一部を誘電体層２が覆いやすくする観点から、前記形状の端部又は頂点、谷は緩やかな曲率をもって湾曲していることが好ましい。また、樹脂基材１と誘電体層２との間の密着強度を高くする観点から、前記断面形状は正弦波状であることがより好ましい。 There is no restriction | limiting in the cross-sectional shape of the grid-like convex part 1a. For example, these cross-sectional shapes may be a sine wave shape such as a trapezoidal shape, a rectangular shape, a square shape, a prism shape, or a semicircular shape. Here, the sinusoidal shape means that it has a curved portion formed by repetition of a concave portion and a convex portion. In addition, the curved part should just be a curved curve, for example, the shape which has a constriction in a convex part is also included in a sine wave form. From the viewpoint of facilitating the dielectric layer 2 to cover at least a part of the lattice-like convex portion 1a and the side surface of the resin base material 1, the end portion, apex, or valley of the shape is curved with a gentle curvature. preferable. Further, from the viewpoint of increasing the adhesion strength between the resin base material 1 and the dielectric layer 2, the cross-sectional shape is more preferably a sine wave shape.
また、樹脂基材１の凹凸格子において、金属ワイヤを誘電体被覆凸部に強固に結合し、金属ワイヤの周囲の屈折率を低減するには、誘電体被覆格子状凸部の断面形状は底部の幅が大きく、頂部の幅が小さい形状が好ましく、先細り程度を示す尺度としては、誘電体被覆格子状凸部の底部から３分の１の高さにおける誘電体被覆格子状凸部の幅ＷＬと、誘電体被覆格子状凸部の底部から３分の２の高さにおける誘電体被覆格子状凸部の幅ＷＨの比ＷＨ／ＷＬがあげられ、この値が０．３〜０．９であることが好ましく、０．３〜０．６がさらに好ましい。また、誘電体被覆凸部の適切な幅と高さは、誘電体被覆凸部自体の強度、金属ワイヤと誘電体被覆凸部の結合力、ワイヤグリッド偏光板の光学性能から決まり、誘電体被覆格子状凸部の底部から２分の１の高さにおける誘電体被覆格子状凸部の幅ＷＭはワイヤピッチＰの０．１倍〜０．５倍が好ましく、底部から頂部までの高さＨ２がワイヤピッチＰの０．５倍〜１．５倍が好ましい。この中で、必要な強度が維持される範囲で、ＷＭは小さい方がさらに好ましい。 Further, in the concavo-convex grid of the resin base material 1, in order to firmly bond the metal wire to the dielectric-covered convex portion and reduce the refractive index around the metal wire, the cross-sectional shape of the dielectric-coated grid-shaped convex portion is the bottom portion. A shape having a large width and a small width at the top is preferable, and as a measure indicating the degree of taper, the width WL of the dielectric-coated grid-shaped convex portion at a height of one third from the bottom of the dielectric-coated grid-shaped convex portion And the ratio WH / WL of the width WH of the dielectric-coated grid-like convex portion at a height of two-thirds from the bottom of the dielectric-coated grid-like convex portion, and this value is 0.3 to 0.9. It is preferable that there is 0.3 to 0.6. Also, the appropriate width and height of the dielectric-covered convex part are determined by the strength of the dielectric-covered convex part itself, the bonding strength between the metal wire and the dielectric-coated convex part, and the optical performance of the wire grid polarizer, The width WM of the dielectric-covered grid-like convex portion at a half height from the bottom of the grid-like convex portion is preferably 0.1 to 0.5 times the wire pitch P, and the height H from the bottom portion to the top portion. 2 is preferably 0.5 to 1.5 times the wire pitch P. Among these, it is more preferable that the WM is small as long as the necessary strength is maintained.
ワイヤグリッド偏光板の高い光学性能を得るためには、適切な金属ワイヤ断面形状を作ることが重要である。前記誘電体被覆格子状凸部形状においては、凸部の頂部高さ付近で金属ワイヤの幅ｔがほぼ最大値となり、幅ｔはワイヤピッチＰの０．３倍〜０．７倍であることが好ましい。また、金属ワイヤの底部と頂部付近では基板面方向の各層の平均屈折率が、徐々に変わることが光学的に好ましく、金属ワイヤの幅は、ｔをほぼ最大値として底部と頂部の端部に向かって減少することが好ましい。すなわち、誘電体被覆格子状凸部の頂部高さにおける金属ワイヤの幅ｔがワイヤピッチＰの０．３倍〜０．７倍で、金属ワイヤの幅がほぼｔを最大値として底部と頂部の端部に向かって減少する形状あり、金属ワイヤの底部から頂部までの高さＨ３が誘電体被覆格子状凸部の底部から金属ワイヤ頂部までの高さＨ１の０．８倍〜１倍であり、誘電体被覆格子状凸部の底部から頂部までの高さＨ２が誘電体被覆格子状凸部の底部から金属ワイヤ頂部までの高さＨ１の０．５倍〜０．９倍であることが好ましい。 In order to obtain the high optical performance of the wire grid polarizer, it is important to make an appropriate metal wire cross-sectional shape. In the dielectric-covered grid-like convex shape, the width t of the metal wire is almost the maximum near the top height of the convex portion, and the width t is 0.3 to 0.7 times the wire pitch P. Is preferred. Further, it is optically preferable that the average refractive index of each layer in the substrate surface direction gradually changes in the vicinity of the bottom and top of the metal wire, and the width of the metal wire is set at the end of the bottom and top with t being substantially the maximum value. It is preferable to decrease towards. That is, the width t of the metal wire at the height of the top of the dielectric-coated grid-shaped convex portion is 0.3 to 0.7 times the wire pitch P, and the width of the metal wire is about t as the maximum value. The height H 3 from the bottom to the top of the metal wire is 0.8 times to 1 times the height H 1 from the bottom to the top of the metal wire. The height H 2 from the bottom to the top of the dielectric-covered grid-like convex portion is 0.5 to 0.9 times the height H 1 from the bottom of the dielectric-covered grid-like convex portion to the top of the metal wire. It is preferable that
また、十分なワイヤ高さを得て、ワイヤグリッド偏光板の偏光度や透過率などの性能を高めることを考慮すると、凹凸格子の凸部山と凹部谷との間の高低差が１００ｎｍ〜３００ｎｍであることが好ましい。 In addition, in consideration of obtaining sufficient wire height and enhancing the performance such as the degree of polarization and transmittance of the wire grid polarizing plate, the height difference between the convex and concave portions of the concave and convex lattice is 100 nm to 300 nm. It is preferable that
本発明のワイヤグリッド偏光板においては、波長がワイヤピッチＰの３倍〜２０００ｎｍの光に対し、偏光度９５以上、透過率３５％以上の偏光性能を有することが好ましく、偏光度９５以上、透過率４０％以上の偏光性能を有することがさらに好ましい。これにより、比較的大きなワイヤピッチＰであっても、波長がワイヤピッチＰの３倍〜２０００ｎｍの光に対し、偏光度９５以上、透過率４０％以上の一定した偏光性能を得ることが可能である。 The wire grid polarizing plate of the present invention preferably has a polarization performance with a polarization degree of 95 or more and a transmittance of 35% or more with respect to light having a wavelength of 3 to 2000 nm of the wire pitch P. More preferably, it has a polarization performance of 40% or more. As a result, even with a relatively large wire pitch P, it is possible to obtain a constant polarization performance with a polarization degree of 95 or more and a transmittance of 40% or more for light having a wavelength of 3 to 2000 nm of the wire pitch P. is there.
樹脂基材１に用いる樹脂は、可視光領域で実質的に透明な樹脂であればよい。例えば、ポリメタクリル酸メチル樹脂、ポリカーボネート樹脂、ポリスチレン樹脂、シクロオレフィン樹脂（ＣＯＰ）、架橋ポリエチレン樹脂、ポリ塩化ビニル樹脂、ポリアリレート樹脂、ポリフェニレンエーテル樹脂、変性ポリフェニレンエーテル樹脂、ポリエーテルイミド樹脂、ポリエーテルサルフォン樹脂、ポリサルフォン樹脂、ポリエーテルケトン樹脂などの非晶性熱可塑性樹脂や、ポリエチレンテレフタレート（ＰＥＴ）樹脂、ポリエチレンナフタレート樹脂、ポリエチレン樹脂、ポリプロピレン樹脂、ポリブチレンテレフタレート樹脂、芳香族ポリエステル樹脂、ポリアセタール樹脂、ポリアミド樹脂などの結晶性熱可塑性樹脂や、アクリル系、エポキシ系、ウレタン系などの紫外線（ＵＶ）硬化性樹脂や熱硬化性樹脂が挙げられる。また、基材として樹脂基材１である紫外線硬化性樹脂や熱硬化性樹脂と、ガラスなどの無機基板、上記熱可塑性樹脂、トリアセテート樹脂とを組み合せた構成とすることもできる。 The resin used for the resin substrate 1 may be a resin that is substantially transparent in the visible light region. For example, polymethyl methacrylate resin, polycarbonate resin, polystyrene resin, cycloolefin resin (COP), cross-linked polyethylene resin, polyvinyl chloride resin, polyarylate resin, polyphenylene ether resin, modified polyphenylene ether resin, polyetherimide resin, polyether Amorphous thermoplastic resins such as sulfone resin, polysulfone resin, polyether ketone resin, polyethylene terephthalate (PET) resin, polyethylene naphthalate resin, polyethylene resin, polypropylene resin, polybutylene terephthalate resin, aromatic polyester resin, polyacetal Examples include crystalline thermoplastic resins such as resins and polyamide resins, and ultraviolet (UV) curable resins and thermosetting resins such as acrylic, epoxy, and urethane types. That. Moreover, it can also be set as the structure which combined the ultraviolet curable resin and thermosetting resin which are the resin base materials 1 as a base material, inorganic board | substrates, such as glass, the said thermoplastic resin, and a triacetate resin.
本発明に用いる格子状凸部を有する樹脂基材を得る方法は特に限定されない。例えば、本出願人の特開２００６−２２４６５９号公報に記載の方法を挙げることができる。特開２００６−２２４６５９号公報によれば、干渉露光法を用いて作製したピッチ２３０ｎｍから２５０ｎｍの格子状凸部がつくる凹凸格子を有する金属スタンパを用いて、凹凸格子を熱可塑性樹脂に熱転写し、凹凸格子を付与した熱可塑性樹脂を格子の長手方向と平行な方向に、延伸倍率が４から６倍の自由端一軸延伸加工を施す。その結果、前記熱可塑性樹脂に転写された凹凸格子のピッチが縮小され、ピッチが１２０ｎｍ以下の微細凹凸格子を有する樹脂基材（延伸済み）が得られる。続いて、得られた微細凹凸格子を有する樹脂基材（延伸済み）から、電解メッキ法などを用いて微細凹凸格子を有する金属スタンパを作製する。この金属スタンパを用いて、樹脂基材の表面にその微細凹凸格子を転写、形成することで、ピッチが１２０ｎｍ以下の格子状凸部を有する樹脂基材を得ることが可能となる。 The method for obtaining a resin base material having a grid-like convex portion used in the present invention is not particularly limited. For example, a method described in Japanese Patent Application Laid-Open No. 2006-224659 of the present applicant can be given. According to Japanese Patent Laid-Open No. 2006-224659, using a metal stamper having a concavo-convex grid formed by a grid-shaped convex part having a pitch of 230 nm to 250 nm produced using an interference exposure method, the concavo-convex grid is thermally transferred to a thermoplastic resin, The thermoplastic resin provided with the concavo-convex lattice is subjected to free end uniaxial stretching with a stretching ratio of 4 to 6 in the direction parallel to the longitudinal direction of the lattice. As a result, the pitch of the concavo-convex lattice transferred to the thermoplastic resin is reduced, and a resin base material (stretched) having a fine concavo-convex lattice with a pitch of 120 nm or less is obtained. Then, the metal stamper which has a fine uneven | corrugated lattice is produced from the resin base material (drawn | stretched) which has the obtained fine uneven | corrugated lattice using the electrolytic plating method. By using this metal stamper to transfer and form the fine concavo-convex lattice on the surface of the resin base material, it becomes possible to obtain a resin base material having lattice-like convex portions with a pitch of 120 nm or less.
本発明において誘電体層２を構成する誘電体は、可視光領域で実質的に透明であれば良い。樹脂基材１を構成する材料及び金属ワイヤ３を構成する金属との間の密着性が高い誘電体材料を好適に用いることができる。例えば、珪素（Ｓｉ）の酸化物（酸化ケイ素）、窒化物（窒化ケイ素）、ハロゲン化物、炭化物の単体又はその複合物（誘電体単体に他の元素、単体又は化合物が混ざった誘電体）や、アルミニウム（Ａｌ）、クロム（Ｃｒ）、イットリウム（Ｙ）、ジルコニア（Ｚｒ）、タンタル（Ｔａ）、チタン（Ｔｉ）、バリウム（Ｂａ）、インジウム（Ｉｎ）、錫（Ｓｎ）、亜鉛（Ｚｎ）、マグネシウム（Ｍｇ）、カルシウム（Ｃａ）、セリウム（Ｃｅ）、銅（Ｃｕ）などの金属の酸化物、窒化物、ハロゲン化物、炭化物の単体又はそれらの複合物を用いることができる。 In the present invention, the dielectric constituting the dielectric layer 2 may be substantially transparent in the visible light region. A dielectric material having high adhesion between the material constituting the resin substrate 1 and the metal constituting the metal wire 3 can be suitably used. For example, silicon (Si) oxide (silicon oxide), nitride (silicon nitride), halide, carbide alone or a composite thereof (dielectric obtained by mixing other elements, simple substances or compounds in a dielectric alone) or , Aluminum (Al), chromium (Cr), yttrium (Y), zirconia (Zr), tantalum (Ta), titanium (Ti), barium (Ba), indium (In), tin (Sn), zinc (Zn) , Magnesium oxide (Mg), calcium (Ca), cerium (Ce), copper (Cu) and other metal oxides, nitrides, halides, carbides alone or a composite thereof can be used.
樹脂基材１の格子状凸部１ａ及びその側面の少なくとも一部に誘電体を被覆させる方法としては、誘電体層２を構成する材料により適宜選択する。例えば、スパッタリング法、真空蒸着法などの物理的蒸着法を好適に用いることができる。密着強度の観点からスパッタリング法が好ましい。 The method of covering the lattice-shaped convex portion 1a of the resin substrate 1 and at least a part of the side surface thereof with a dielectric is appropriately selected depending on the material constituting the dielectric layer 2. For example, a physical vapor deposition method such as a sputtering method or a vacuum vapor deposition method can be suitably used. The sputtering method is preferable from the viewpoint of adhesion strength.
本発明において、金属ワイヤ３を構成する金属は、可視光領域で光の反射率が高く、誘電体層２を構成する材料との間の密着性の高いものであることが好ましい。例えば、アルミニウム、銀又はそれらの合金で構成されていることが好ましい。コストの観点から、アルミニウム又はその合金で構成されていることがさらに好ましい。 In the present invention, it is preferable that the metal constituting the metal wire 3 has high light reflectance in the visible light region and high adhesion with the material constituting the dielectric layer 2. For example, it is preferably made of aluminum, silver or an alloy thereof. From the viewpoint of cost, it is more preferable that it is made of aluminum or an alloy thereof.
本発明のワイヤグリッド偏光板においては、横断面視においてワイヤグリッド偏光板の金属ワイヤ面側への垂直方向から金属ワイヤが形成されていない面側へ入射角を４５°ずらした場合に、透過すべき光（Ｐ波）の透過率（Ｔｐ）が、８０％以上であることが好ましい。本実施の形態で示すワイヤグリッド偏光板の構造上、金属ワイヤは非対称形状で形成されるが、ワイヤグリッド偏光板の金属ワイヤ面側への垂直方向から金属ワイヤが形成されていない面側へ入射角を４５°ずらした側からのＰ波は、金属ワイヤが形成されていない面側への垂直方向から金属ワイヤが形成されている面側へ入射角を４５°ずらした側からのＰ波に比べ、実質的にワイヤグリッドの透過光路によりＡｌの断面体積比が変化するため（透過光路により見かけのＡｌの形状が変化するため）、透過率が向上する。ここで、横断面視とは、凹凸格子部が延在する特定方向に垂直な面での断面視とし、入射角とは、図１及び図８に図示するように、横断面視（格子状基材凸部の延在方向に垂直な断面）で、基材凸部立設方向で凸部上方への角度を０°としたとき、金属ワイヤ形成面側への角度θを正とし、反対側（金属ワイヤが形成されていない面側）の角度θを負と定義する。 In the wire grid polarizing plate of the present invention, when the incident angle is shifted by 45 ° from the direction perpendicular to the metal wire surface side of the wire grid polarizing plate to the surface side where the metal wire is not formed in a cross sectional view, the wire grid polarizing plate transmits light. The transmittance (Tp) of power light (P wave) is preferably 80% or more. Although the metal wire is formed in an asymmetric shape due to the structure of the wire grid polarizer shown in the present embodiment, it is incident on the surface side where the metal wire is not formed from the direction perpendicular to the metal wire surface side of the wire grid polarizer. The P wave from the side where the angle is shifted by 45 ° is changed to the P wave from the side where the incident angle is shifted by 45 ° from the direction perpendicular to the surface side where the metal wire is not formed to the surface side where the metal wire is formed. In comparison, since the cross-sectional volume ratio of Al is substantially changed by the transmission optical path of the wire grid (because the apparent shape of Al is changed by the transmission optical path), the transmittance is improved. Here, the cross-sectional view is a cross-sectional view in a plane perpendicular to a specific direction in which the concavo-convex lattice portion extends, and the incident angle is a cross-sectional view (grating form) as shown in FIGS. In the cross section perpendicular to the extending direction of the base material convex part), when the angle above the convex part in the base material convex part standing direction is 0 °, the angle θ toward the metal wire forming surface side is positive and opposite The angle θ on the side (surface side on which no metal wire is formed) is defined as negative.
さらに、本発明のワイヤグリッド偏光板においては、遮光すべき光（Ｓ波）の透過率（Ｔｓ）が、０．５％以下であることが好ましい。このように、入射角を４５°としたときにＴｓ、Ｔｐ等の偏光特性に優れると、ビームスプリッターなどの光学機器（光学システム）の構成上、ワイヤグリッド偏光板が光学機器に組み込まれる際に、優れた光学特性を発揮し、設計の自由度が増すため、好ましい。 Furthermore, in the wire grid polarizing plate of the present invention, the transmittance (Ts) of light (S wave) to be shielded is preferably 0.5% or less. As described above, when the incident angle is 45 ° and the polarization characteristics such as Ts and Tp are excellent, the configuration of the optical device (optical system) such as the beam splitter causes the wire grid polarizing plate to be incorporated into the optical device. It is preferable because it exhibits excellent optical characteristics and increases the degree of freedom in design.
さらに、本発明のワイヤグリッド偏光板においては、金属ワイヤの蒸着源から被蒸着部までの距離を調整することで基材凹部底部に金属ワイヤの堆積を妨げることができ、波長依存性を低減することができる。特に、可視光域において、優れた光学特性を発揮する。 Furthermore, in the wire grid polarizing plate of the present invention, by adjusting the distance from the vapor deposition source of the metal wire to the deposition target portion, the deposition of the metal wire on the bottom of the concave portion of the base material can be prevented, and the wavelength dependency is reduced. be able to. In particular, it exhibits excellent optical characteristics in the visible light range.
金属ワイヤ３を形成するために金属を誘電体層２に積層する方法としては、誘電体層２を構成する材料と金属ワイヤ３を構成する金属との間に十分な密着性が得られる方法であれば、特に限定されない。例えば、真空蒸着法、スパッタリング法、イオンプレーティング法などの物理的蒸着法を好適に用いることができる。中でも、金属を誘電体層２の凸部に選択的に、又は誘電体層２の凸部の一方の側面に偏って選択的に積層できるような方法が好ましい。そのような方法として、例えば、蒸着ボート（蒸着源）を用いた真空蒸着法が挙げられる。 As a method of laminating a metal on the dielectric layer 2 in order to form the metal wire 3, a method of obtaining sufficient adhesion between the material constituting the dielectric layer 2 and the metal constituting the metal wire 3. If there is, it will not be specifically limited. For example, a physical vapor deposition method such as a vacuum vapor deposition method, a sputtering method, or an ion plating method can be suitably used. Among them, a method in which a metal can be selectively laminated on the convex portion of the dielectric layer 2 or selectively biased to one side surface of the convex portion of the dielectric layer 2 is preferable. As such a method, for example, a vacuum evaporation method using an evaporation boat (evaporation source) can be cited.
なお、光学特性の観点から、微細凹凸格子の凹部の底部及びその付近に積層する金属の量は少ないほど良い。したがって、これらの部分に金属が堆積するのを避けるため、さらには、堆積した場合に、後述するエッチング（による洗浄）を容易にすることを考慮すると、斜め積層法を用いて金属を積層することが好ましい。本発明でいう斜め積層法とは、微細凹凸格子の格子長手方向と垂直に交わる平面内で、樹脂基材面の法線と蒸着源とのなす角度（入射角度）θが４５°から５°の範囲で、好ましくは３５°から１０°の範囲で金属を積層する方法である。 From the viewpoint of optical characteristics, the smaller the amount of metal laminated on the bottom of the concave portion of the fine concavo-convex lattice and the vicinity thereof, the better. Therefore, in order to avoid deposition of metal in these portions, and in addition, in consideration of facilitating etching (cleaning by later) when deposited, the metal is laminated using the oblique lamination method. Is preferred. The oblique lamination method referred to in the present invention is an angle (incident angle) θ between the normal of the resin substrate surface and the vapor deposition source in a plane perpendicular to the lattice longitudinal direction of the fine concavo-convex lattice, and is 45 ° to 5 °. The metal is laminated in the range of preferably 35 ° to 10 °.
上記のような斜め積層法を用いることにより、金属ワイヤ３が格子状凸部１ａの一方の側面上方にかけて形成される。これにより、金属ワイヤ３が誘電体層２で被覆された格子状凸部１ａの頂部より少なくとも上方に存在し、金属ワイヤ軸Ａと、格子状凸部軸Ｂとがずれる構成とすることができ、これにより、可視光領域の広帯域にわたって波長依存性が無く、優れた偏光度及び透過率を両立できるワイヤグリッド偏光板を得ることができる。この場合において、金属ワイヤ３の頂部、すなわち、金属ワイヤ３の高さを１００％としたときの５％〜６０％が、誘電体層２の凸部頂部よりも高い、すなわち、金属ワイヤ３の高さの４０％〜９５％が誘電体層２の凸部側面と接合することが好ましい。 By using the oblique lamination method as described above, the metal wire 3 is formed over one side surface of the lattice-like convex portion 1a. As a result, the metal wire 3 is present at least above the top of the lattice-like convex portion 1a covered with the dielectric layer 2, and the metal wire axis A and the lattice-like convex portion axis B can be shifted. Thus, it is possible to obtain a wire grid polarizing plate that has no wavelength dependency over a wide band in the visible light region and can achieve both excellent polarization degree and transmittance. In this case, the top of the metal wire 3, that is, 5% to 60% when the height of the metal wire 3 is 100% is higher than the top of the convex portion of the dielectric layer 2, that is, the metal wire 3 It is preferable that 40% to 95% of the height is bonded to the convex side surface of the dielectric layer 2.
金属ワイヤ３において、頂部及び／又は底部の断面形状は、光学性能を保持しながら高さの高いワイヤでも強固に基材に固定できることを考慮して、先細り形状であることが好ましい。 In the metal wire 3, the cross-sectional shape of the top and / or the bottom is preferably a tapered shape in consideration of the fact that even a high height wire can be firmly fixed to the substrate while maintaining optical performance.
次に、本発明に係るワイヤグリッド偏光板を液晶表示装置に用いた場合について説明する。図２に、本発明の実施の形態に係るワイヤグリッド偏光板を用いた液晶表示装置の一形態を示す。 Next, the case where the wire grid polarizing plate according to the present invention is used in a liquid crystal display device will be described. FIG. 2 shows one mode of a liquid crystal display device using the wire grid polarizer according to the embodiment of the present invention.
図２に示す液晶表示装置は、光を発光するバックライトのような照明装置２１と、この照明装置２１上に配置されたワイヤグリッド偏光板２２と、ワイヤグリッド偏光板２２上に配置された液晶パネル２３及び偏光板２４とから主に構成される。すなわち、本発明に係るワイヤグリッド偏光板２２は、液晶パネル２３と照明装置２１との間に配置される。 The liquid crystal display device shown in FIG. 2 includes a lighting device 21 such as a backlight that emits light, a wire grid polarizing plate 22 disposed on the lighting device 21, and a liquid crystal disposed on the wire grid polarizing plate 22. It is mainly comprised from the panel 23 and the polarizing plate 24. FIG. That is, the wire grid polarizing plate 22 according to the present invention is disposed between the liquid crystal panel 23 and the lighting device 21.
液晶パネル２３は、例えば、透過型液晶パネルであり、ガラスや透明樹脂基板間に液晶材料などを挟持して構成されている。なお、図２の液晶表示装置中において、通常使用されている偏光板保護フィルム、位相差フィルム、拡散板、配向膜、透明電極、カラーフィルタなどの各種光学素子については説明を省略する。 The liquid crystal panel 23 is, for example, a transmissive liquid crystal panel, and is configured by sandwiching a liquid crystal material or the like between glass and a transparent resin substrate. In the liquid crystal display device of FIG. 2, description of various optical elements such as a polarizing plate protective film, a retardation film, a diffusion plate, an alignment film, a transparent electrode, and a color filter that are usually used is omitted.
このような構成の液晶表示装置においては、照明装置２１から出射された光がワイヤグリッド偏光板２２の樹脂基材１の基部側から入射し、ワイヤ側から液晶パネル２３を通過して外界に出射される（図中の矢印方向）。この場合において、ワイヤグリッド偏光板２２が可視光領域において優れた偏光度を発揮するので、コントラストの高い表示を得ることが可能となる。また、さらに高いコントラストが要求される場合には、偏光板２４の外側、すなわち照明装置２１と反対の方向から入射する（外）光が、液晶パネル２３を透過してワイヤグリッド偏光板２２により反射され、再び液晶パネル２３の外側に戻るのを防止するために、ワイヤグリッド偏光板２２と液晶パネル２３との間に、ヨウ素などの二色性色素を用いた吸収型の偏光板を、ワイヤグリッド偏光板２２と偏光軸を合わせて挿入することが好ましい。この場合、吸収型の偏光板は透過率が高いものが好ましく、偏光度は低いものであっても良い。 In the liquid crystal display device having such a configuration, the light emitted from the illumination device 21 enters from the base side of the resin base material 1 of the wire grid polarizing plate 22, passes through the liquid crystal panel 23 from the wire side, and exits to the outside. (In the direction of the arrow in the figure). In this case, since the wire grid polarizing plate 22 exhibits an excellent degree of polarization in the visible light region, a display with high contrast can be obtained. Further, when higher contrast is required, light incident from the outside of the polarizing plate 24, that is, from the direction opposite to the illumination device 21 (external) is transmitted through the liquid crystal panel 23 and reflected by the wire grid polarizing plate 22. In order to prevent returning to the outside of the liquid crystal panel 23 again, an absorption type polarizing plate using a dichroic dye such as iodine is provided between the wire grid polarizing plate 22 and the liquid crystal panel 23. It is preferable to insert the polarizing plate 22 and the polarization axis. In this case, the absorption type polarizing plate preferably has a high transmittance and may have a low degree of polarization.
また、本発明のワイヤグリッド偏光板を投射型液晶表示装置の偏光板に用いても良い。投射型液晶表示装置は、光源と、その光源からの光を偏光分離するワイヤグリッド偏光板と、そのワイヤグリッド偏光板により偏光された光を透過又は反射する液晶表示素子と、その液晶表示素子を透過又は反射した光をスクリーンに投射する投射光学系とから主に構成される。すなわち、本発明に係るワイヤグリッド偏光板は、光源と液晶表示素子との間に配置される。 Moreover, you may use the wire grid polarizing plate of this invention for the polarizing plate of a projection type liquid crystal display device. A projection-type liquid crystal display device includes a light source, a wire grid polarizing plate that polarizes and separates light from the light source, a liquid crystal display element that transmits or reflects light polarized by the wire grid polarizing plate, and the liquid crystal display element. It is mainly composed of a projection optical system that projects the transmitted or reflected light onto the screen. That is, the wire grid polarizing plate according to the present invention is disposed between the light source and the liquid crystal display element.
次に、本発明の効果を明確にするために行った実施例について説明する。
（格子状凸部を有する樹脂基材の作製）
・凹凸格子形状が転写されたＣＯＰ板の作製
ピッチが２３０ｎｍで、凹凸格子の高さが２３０ｎｍである凹凸格子を表面に有するニッケルスタンパを準備した。この凹凸格子は、レーザ干渉露光法を用いたパターニングにより作製されたものであり、その断面形状は正弦波状で、上面からの形状は縞状格子形状であった。また、その平面寸法は縦横ともに５００ｍｍであった。このニッケルスタンパを用いて、熱プレス法により厚さ０．５ｍｍ、縦横がそれぞれ５２０ｍｍのシクロオレフィン樹脂（以下、ＣＯＰ板と略す）の表面に凹凸格子形状を転写し、凹凸格子形状が転写されたＣＯＰ板を作製した。このＣＯＰのガラス転移温度（Ｔｇ）は１０５℃であった。
Next, examples performed for clarifying the effects of the present invention will be described.
(Preparation of a resin base material having a grid-like convex portion)
-Preparation of COP plate with concavo-convex lattice shape transferred A nickel stamper having a concavo-convex lattice with a pitch of 230 nm and a height of the concavo-convex lattice of 230 nm was prepared. The concavo-convex grating was produced by patterning using a laser interference exposure method, and the cross-sectional shape was a sine wave shape, and the shape from the top surface was a striped lattice shape. Moreover, the plane dimension was 500 mm in both length and width. Using this nickel stamper, the concavo-convex lattice shape was transferred to the surface of a cycloolefin resin (hereinafter abbreviated as COP plate) having a thickness of 0.5 mm and a width and width of 520 mm by a hot press method. A COP plate was produced. The glass transition temperature (Tg) of this COP was 105 ° C.
具体的に、熱プレスは次のように行った。まず、プレス機の系内を真空排気し、ニッケルスタンパ及びＣＯＰ板を１９０℃まで加熱した。ニッケルスタンパ及びＣＯＰ板が１９０℃に達した後、プレス圧２ＭＰａ、プレス時間４分でニッケルスタンパの凹凸格子をＣＯＰ板に転写した。さらに、プレス圧を２ＭＰａに保持したままニッケルスタンパ及びＣＯＰ板を４０℃まで冷却した後、真空開放し、続けてプレス圧を開放した。プレス圧を開放したとき、ニッケルスタンパ及びＣＯＰ板は容易に離型した。電界放出型走査型電子顕微鏡（以下、ＦＥ−ＳＥＭと略す）で、凹凸格子形状が転写されたＣＯＰ板の表面形状を観察したところ、ニッケルスタンパの凹凸格子形状が忠実に転写されたことが確認された。 Specifically, the hot press was performed as follows. First, the inside of the press system was evacuated, and the nickel stamper and COP plate were heated to 190 ° C. After the nickel stamper and the COP plate reached 190 ° C., the concave / convex grid of the nickel stamper was transferred to the COP plate with a press pressure of 2 MPa and a press time of 4 minutes. Further, the nickel stamper and the COP plate were cooled to 40 ° C. while maintaining the press pressure at 2 MPa, then the vacuum was released, and the press pressure was subsequently released. When the press pressure was released, the nickel stamper and COP plate were easily released. Using a field emission scanning electron microscope (hereinafter abbreviated as FE-SEM), the surface shape of the COP plate onto which the concavo-convex lattice shape was transferred was confirmed, and it was confirmed that the concavo-convex lattice shape of the nickel stamper was faithfully transferred. It was done.
・延伸によるピッチ縮小
次いで、この凹凸格子形状が転写されたＣＯＰ板を５２０ｍｍ×４６０ｍｍの長方形に切り出し、被延伸部材としての延伸用ＣＯＰ板とした。このとき、５２０ｍｍ×４６０ｍｍの長手方向（５２０ｍｍ）と凹凸格子の長手方向とが互いに略平行になるように切り出した。
-Pitch reduction by stretching Next, the COP plate to which the concavo-convex lattice shape was transferred was cut into a 520 mm x 460 mm rectangle to obtain a stretching COP plate as a stretched member. At this time, it was cut out so that the longitudinal direction (520 mm) of 520 mm × 460 mm and the longitudinal direction of the concavo-convex lattice were substantially parallel to each other.
次いで、この延伸用ＣＯＰ板の表面に、スプレーによりシリコーンオイルを塗布し、約８０℃の循環式空気オーブン中に３０分放置した。次いで、延伸用ＣＯＰ板の長手方向の両端１０ｍｍを延伸機のチャックで固定し、その状態で１１３±１℃に温度調節された循環式空気オーブン中に延伸用ＣＯＰ板を１０分間放置した。その後、２５０ｍｍ／分の速度でチャック間の距離が５倍延伸したところで延伸を終え、２０秒後に延伸したＣＯＰ板（延伸済みＣＯＰ板）を室温雰囲気下に取り出し、チャック間の距離を維持したまま冷却した。この延伸済みＣＯＰ板の中央部分約４０％は、ほぼ均一にくびれており、最も幅が縮小されている部分は２００ｍｍになっていた。同様にして、チャック間の距離のみを３．５倍、２．５倍に変えて延伸したところ、延伸済みＣＯＰ板中央部の最小幅は、それぞれ、２４０ｍｍ、２８０ｍｍになっていた。 Next, silicone oil was applied to the surface of the stretching COP plate by spraying and left in a circulating air oven at about 80 ° C. for 30 minutes. Next, both ends 10 mm in the longitudinal direction of the stretching COP plate were fixed with a chuck of a stretching machine, and in that state, the stretching COP plate was left in a circulating air oven adjusted to 113 ± 1 ° C. for 10 minutes. After that, when the distance between the chucks was stretched 5 times at a speed of 250 mm / min, the stretching was finished, and after 20 seconds, the stretched COP plate (stretched COP plate) was taken out in a room temperature atmosphere, and the distance between the chucks was maintained. Cooled down. About 40% of the center portion of the stretched COP plate was substantially uniformly constricted, and the portion with the smallest width was 200 mm. Similarly, when stretching was performed while changing only the distance between the chucks to 3.5 times and 2.5 times, the minimum width of the center portion of the stretched COP plate was 240 mm and 280 mm, respectively.
この延伸済みＣＯＰ板３種の表面と断面を、ＦＥ−ＳＥＭにて観察したところ、微細凹凸格子のピッチと高さはそれぞれ、１００ｎｍ／９５ｎｍ（ピッチ／高さ）、１２０ｎｍ／１１３ｎｍ、１４０ｎｍ／１３３ｎｍであり、その断面形状は正弦波状で、上面からの形状は縞状格子状となっており、実質的に延伸前の凹凸格子形状と相似で縮小されていたことが分かった。 When the surface and cross section of the three types of stretched COP plates were observed with an FE-SEM, the pitch and height of the fine concavo-convex grating were 100 nm / 95 nm (pitch / height), 120 nm / 113 nm, and 140 nm / 133 nm, respectively. It was found that the cross-sectional shape was sinusoidal, the shape from the top surface was a striped lattice shape, and was substantially reduced in size similar to the uneven lattice shape before stretching.
・ニッケルスタンパ作製
得られた、１００ｎｍピッチ、１２０ｎｍピッチ、及び１４０ｎｍピッチの延伸済みＣＯＰ板表面に、それぞれ導電化処理として金をスパッタリングにより３０ｎｍ被覆した後、それぞれニッケルを電気メッキし、厚さ０．３ｍｍ、格子の長手方向（以下、縦という）３００ｍｍ、格子の長手方向と垂直な方向（以下、横という）１８０ｍｍのニッケルスタンパを作製した。
-Nickel stamper production The surfaces of the obtained 100 nm pitch, 120 nm pitch, and 140 nm pitch stretched COP plates were each coated with gold by sputtering as a conductive treatment, and then electroplated with nickel to obtain a thickness of 0. A nickel stamper of 3 mm, 300 mm in the longitudinal direction of the lattice (hereinafter referred to as “vertical”), and 180 mm in the direction perpendicular to the longitudinal direction of the lattice (hereinafter referred to as “lateral”) was produced.
・紫外線硬化樹脂を用いた格子状凸部転写フィルムの作製
厚み０．１ｍｍのポリエチレンテレフタレート樹脂（以下、ＰＥＴと略す）フィルムに紫外線硬化樹脂（東亜合成Ｍ３５０：１００部 日本チバ・ガイギー社イルガキュア９０７：３部）を約０．０１ｍｍ塗布し、塗布面を下にして上記１００ｎｍピッチ、１２０ｎｍピッチ、及び１４０ｎｍピッチの微細凹凸格子を有するニッケルスタンパ上に、それぞれ端部からニッケルスタンパとフィルム間に空気が入らないように載せ、ＰＥＴフィルム側から中心波長３６５ｎｍの紫外線ランプを用いて紫外線を１０００ｍＪ／ｃｍ２照射し、ニッケルスタンパの微細凹凸格子を転写、硬化した。得られた格子状凸部転写フィルムを、格子状凸部を有する樹脂基材として用いる。
-Production of lattice-shaped convex transfer film using ultraviolet curable resin 0.1 mm thick polyethylene terephthalate resin (hereinafter abbreviated as PET) film and ultraviolet curable resin (Toa Gosei M350: 100 parts) Irgacure 907 3 parts) is applied on the surface of the nickel stamper having the fine uneven grating having a pitch of 100 nm, 120 nm, and 140 nm with the coating surface facing down, and air flows between the nickel stamper and the film from the respective ends. The sample was placed so as not to enter, and irradiated with 1000 mJ / cm 2 of ultraviolet rays from the PET film side using an ultraviolet lamp having a central wavelength of 365 nm, and the fine uneven lattice of the nickel stamper was transferred and cured. The obtained lattice-like convex transfer film is used as a resin substrate having a lattice-like convex portion.
（ワイヤグリッド偏光板の作製：実施例１）
・スパッタリング法を用いた誘電体層の形成
上記の方法で作製した３種類のピッチを持つ格子状凸部転写フィルムに、スパッタリング法を用い誘電体層を形成した。本実施例では、誘電体として窒化珪素を用いた場合について説明する。Ａｒガス圧力０．６７Ｐａ、スパッタリングパワー４Ｗ／ｃｍ２、被覆速度０．２２ｎｍ／ｓにて誘電体の被覆を行った。層厚み比較用サンプルとして表面が平滑なガラス基板を格子状凸部転写フィルムと同時に装置に挿入し、平滑ガラス基板への誘電体積層厚みが３ｎｍとなるように成膜を行った。誘電体を被覆した格子状凸部転写フィルムの断面を、ＦＥ−ＳＥＭで観察し、幅比ＷＨ／ＷＬ（格子状凸部の底部から３分の１の高さにおける格子状凸部の幅ＷＬと、格子状凸部の底部から３分の２の高さにおける前記格子状凸部の幅ＷＨとの間の比）を求めた。その結果、ＷＨがＷＬの０．６倍であり、ＷＭがワイヤピッチＰの０．３倍であり、Ｈ２がワイヤピッチＰの１．０５倍であることを確認した。さらに、ずれ量ＤがワイヤピッチＰの０．２５倍であることを確認した。また、格子状凸部間の凹部の形状が略放物線形状であることも確認した。
(Preparation of wire grid polarizer: Example 1)
-Formation of dielectric layer using sputtering method A dielectric layer was formed using a sputtering method on the lattice-shaped convex transfer film having three types of pitches produced by the above method. In this embodiment, a case where silicon nitride is used as a dielectric will be described. The dielectric was coated at an Ar gas pressure of 0.67 Pa, a sputtering power of 4 W / cm 2 , and a coating speed of 0.22 nm / s. As a layer thickness comparison sample, a glass substrate having a smooth surface was inserted into the apparatus at the same time as the lattice-shaped convex transfer film, and film formation was performed so that the dielectric laminate thickness on the smooth glass substrate was 3 nm. The cross section of the lattice-shaped convex transfer film coated with the dielectric was observed with an FE-SEM, and the width ratio WH / WL (the width WL of the lattice-shaped convex at a height of one third from the bottom of the lattice-shaped convex portion. And the width WH of the lattice-shaped convex portion at a height of two-thirds from the bottom of the lattice-shaped convex portion. As a result, WH is 0.6 times of WL, WM is 0.3 times the wire pitch P, H 2 was confirmed to be 1.05 times the wire pitch P. Further, it was confirmed that the deviation D was 0.25 times the wire pitch P. Moreover, it confirmed that the shape of the recessed part between lattice-shaped convex parts was a substantially parabolic shape.
・真空蒸着法を用いた金属の蒸着
３種類のピッチを持つ格子状凸部転写フィルムに誘電体層を形成した後、抵抗加熱蒸着を用いて金属ワイヤを形成した。実施例１では、金属としてアルミニウム（Ａｌ）を用いた場合について説明する。真空度２．５×１０-３Ｐａ、蒸着速度４ｎｍ／ｓ、蒸着ボートからの距離２００ｍｍ、常温下においてＡｌの蒸着を行った。層厚み比較用サンプルとして表面が平滑なガラス基板を誘電体積層格子状凸部転写フィルムと同時に装置に挿入し、平滑基板へのＡｌ蒸着厚みが１１０ｎｍとなるように蒸着を行った。実施例１では、格子の長手方向と垂直に交わる平面内において基材面の法線と蒸着源とのなす角度θを２０°とした。
-Metal vapor deposition using vacuum vapor deposition After forming a dielectric layer on a lattice-shaped convex transfer film having three types of pitches, metal wires were formed using resistance heating vapor deposition. In Example 1, a case where aluminum (Al) is used as a metal will be described. Al was vapor-deposited at a vacuum degree of 2.5 × 10 −3 Pa, a vapor deposition rate of 4 nm / s, a distance from the vapor deposition boat of 200 mm, and normal temperature. As a layer thickness comparison sample, a glass substrate having a smooth surface was inserted into the apparatus at the same time as the dielectric laminated grid convex transfer film, and vapor deposition was performed so that the Al deposition thickness on the smooth substrate was 110 nm. In Example 1, the angle θ formed by the normal of the substrate surface and the vapor deposition source was set to 20 ° in a plane perpendicular to the longitudinal direction of the lattice.
・エッチングによる不要金属の除去
３種類のピッチを持つ格子状凸部転写フィルムに誘電体及びＡｌを積層した後、フィルムを室温下の０．２重量％水酸化ナトリウム水溶液中で、処理時間を３０〜９０秒の間で１０秒間隔で変えながら洗浄（エッチング）し、すぐに水洗してエッチングを停止させた。
-Removal of unnecessary metal by etching After laminating dielectric and Al on a lattice-shaped convex transfer film having three kinds of pitches, the film is treated in a 0.2 wt% aqueous sodium hydroxide solution at room temperature for a treatment time of 30. Washing (etching) was performed while changing at intervals of 10 seconds between -90 seconds, and then immediately washing with water to stop the etching.
金属を形成した格子状凸部転写フィルムの断面を、ＦＥ−ＳＥＭのＳＴＥＭモードで観察し、ワイヤピッチＰを求めた。このとき（ピッチ１４０ｎｍで作製したワイヤグリッド偏光板）のＳＴＥＭ像を図３に示す。そして、このＳＴＥＭ像において、誘電体被覆格子状凸部の頂部高さにおける金属ワイヤの幅ｔがワイヤピッチＰの０．５倍であることを確認した。また、金属ワイヤの底部から頂部までの高さＨ３が誘電体被覆格子状凸部の底部から金属ワイヤ頂部までの高さＨ１の１倍であり、誘電体被覆格子状凸部の底部から頂部までの高さＨ２が誘電体被覆格子状凸部の底部から金属ワイヤ頂部までの高さＨ１の０．７倍であることを確認した。さらに、このＳＴＥＭ像において、金属ワイヤが誘電体層で被覆された格子状凸部の頂部より少なくとも上方に存在し、金属ワイヤ軸と、格子状凸部軸とがずれていることを確認した。 The cross section of the lattice-shaped convex transfer film on which the metal was formed was observed in the STEM mode of FE-SEM, and the wire pitch P was determined. A STEM image of this time (wire grid polarizing plate manufactured at a pitch of 140 nm) is shown in FIG. In this STEM image, it was confirmed that the width t of the metal wire at the height of the top of the dielectric-coated grid-like convex portion was 0.5 times the wire pitch P. Further, the height H 3 from the bottom to the top of the metal wire is one times the height H 1 from the bottom of the dielectric-covered grid-shaped convex portion to the top of the metal wire, and from the bottom of the dielectric-coated grid-shaped convex portion. height H 2 of to the top was confirmed to be 0.7 times the height H 1 to the metal wire from bottom to top of the dielectric coating the grid-shaped convex portions. Further, in this STEM image, it was confirmed that the metal wire was present at least above the top of the lattice-shaped convex portion covered with the dielectric layer, and the metal wire axis and the lattice-shaped convex portion axis were shifted.
（ワイヤグリッド偏光板の作製：実施例２）
蒸着ボートからの距離２００ｍｍを、５００ｍｍに換え、平滑基板へのＡｌ蒸着厚みが６０ｎｍとなるように蒸着をし、エッチングを省略した以外は、実施例１と同様の作業によりワイヤグリッド偏光板を作製した。
(Preparation of wire grid polarizer: Example 2)
A wire grid polarizing plate was produced by the same operation as in Example 1 except that the distance from the vapor deposition boat was changed to 500 mm, vapor deposition was performed so that the Al vapor deposition thickness on the smooth substrate was 60 nm, and etching was omitted. did.
金属を形成した格子状凸部転写フィルムの断面を、ＦＥ−ＳＥＭのＳＴＥＭモードで観察し、ワイヤピッチＰを求めた。このとき（ピッチ１４０ｎｍで作製したワイヤグリッド偏光板）のＳＴＥＭ像を図９に示す。そして、このＳＴＥＭ像において、誘電体被覆格子状凸部の頂部高さにおける金属ワイヤの幅ｔがワイヤピッチＰの０．５倍であることを確認した。また、金属ワイヤの底部から頂部までの高さＨ３が誘電体被覆格子状凸部の底部から金属ワイヤ頂部までの高さＨ１の１倍であり、誘電体被覆格子状凸部の底部から頂部までの高さＨ２が誘電体被覆格子状凸部の底部から金属ワイヤ頂部までの高さＨ１の０．７倍であることを確認した。さらに、このＳＴＥＭ像において、金属ワイヤが誘電体層で被覆された格子状凸部の頂部より少なくとも上方に存在し、金属ワイヤ軸と、格子状凸部軸とがずれていることを確認した。また、格子状凹部底部において、ほとんど金属ワイヤの堆積が見られないことを確認した。 The cross section of the lattice-shaped convex transfer film on which the metal was formed was observed in the STEM mode of FE-SEM, and the wire pitch P was determined. A STEM image of this time (wire grid polarizing plate manufactured at a pitch of 140 nm) is shown in FIG. In this STEM image, it was confirmed that the width t of the metal wire at the height of the top of the dielectric-coated grid-like convex portion was 0.5 times the wire pitch P. Further, the height H 3 from the bottom to the top of the metal wire is one times the height H 1 from the bottom of the dielectric-covered grid-shaped convex portion to the top of the metal wire, and from the bottom of the dielectric-coated grid-shaped convex portion. height H 2 of to the top was confirmed to be 0.7 times the height H 1 to the metal wire from bottom to top of the dielectric coating the grid-shaped convex portions. Further, in this STEM image, it was confirmed that the metal wire was present at least above the top of the lattice-shaped convex portion covered with the dielectric layer, and the metal wire axis and the lattice-shaped convex portion axis were shifted. It was also confirmed that almost no metal wire was deposited at the bottom of the lattice-shaped recess.
比較例として、斜め積層法を用いずに、格子状凸部の直上方向から金属を積層すること以外は上記の実施例１と同様にしてワイヤグリッド偏光板を作製した。このワイヤグリッド偏光板の断面をＦＥ−ＳＥＭのＳＴＥＭモードで観察したところ、図１２に示すような断面形状、すなわち、金属ワイヤ軸と、格子状凸部軸とがずれていない形状を有していた。 As a comparative example, a wire grid polarizing plate was produced in the same manner as in Example 1 above, except that the metal was laminated from the direction directly above the lattice-shaped convex portion without using the oblique lamination method. When the cross section of this wire grid polarizing plate was observed in the STEM mode of FE-SEM, it had a cross sectional shape as shown in FIG. 12, that is, a shape in which the metal wire axis and the grid-like convex axis were not shifted. It was.
（分光光度計による偏光性能評価）
得られた実施例及び比較例のワイヤグリッド偏光板について、分光光度計（日本分光社製 型番Ｖ７１００＋ＶＡＰ７０７０）を用い偏光度及び透過率を測定した。ここでは、直線偏光に対する平行ニコル、直交ニコル状態での光線の透過率を測定し、偏光度、透過率は下記式より算出した。また、測定波長域は可視光の領域を含む４００ｎｍ〜２０００ｎｍとした。図４には、４００ｎｍ〜２０００ｎｍにわたる透過率の変化を示した。
偏光度＝[（Ｉmax−Ｉmin）／（Ｉmax＋Ｉmin）]×１００
透過率＝[（Ｉmax＋Ｉmin）／２] ×１００ ％
ここで、Ｉmaxは平行ニコル時の透過率であり、Ｉminは直交ニコル時の透過率である。また、Ｉmax×１００（％）は、透過すべき光Ｐ波の透過率（Ｔｐ）を示し、Ｉmin×１００（％）は、反射すべき光Ｓ波の透過率（Ｔｓ）を示す。
(Evaluation of polarization performance by spectrophotometer)
About the obtained wire grid polarizing plate of the Example and the comparative example, the degree of polarization and the transmittance | permeability were measured using the spectrophotometer (the JASCO Corporation model number V7100 + VAP7070). Here, the light transmittance in the parallel Nicols state and the crossed Nicols state with respect to the linearly polarized light was measured, and the degree of polarization and the transmittance were calculated from the following equations. The measurement wavelength range was 400 nm to 2000 nm including the visible light range. FIG. 4 shows the change in transmittance over 400 nm to 2000 nm.
Polarization degree = [(Imax−Imin) / (Imax + Imin)] × 100
Transmittance = [(Imax + Imin) / 2] × 100%
Here, Imax is the transmittance at the time of parallel Nicols, and Imin is the transmittance at the time of crossed Nicols. Further, Imax × 100 (%) indicates the transmittance (Tp) of the light P wave to be transmitted, and Imin × 100 (%) indicates the transmittance (Ts) of the light S wave to be reflected.
図４は、ワイヤグリッド偏光板の入射角を−４５°ずらして光を照射した場合の透過率を示している。図４から分かるように、本発明に係るワイヤグリッド偏光板（実施例１）は、可視光領域のほぼ全領域にわたってほぼ均一の透過率を示した。すなわち、本発明に係るワイヤグリッド偏光板は、透過率の波長依存性がなかった。また、本発明に係るワイヤグリッド偏光板は、入射角−４５°、波長５００〜８００ｎｍにて、９９．８以上の高い偏光度を示した。 FIG. 4 shows the transmittance when the incident angle of the wire grid polarizer is shifted by −45 ° and light is irradiated. As can be seen from FIG. 4, the wire grid polarizer (Example 1) according to the present invention exhibited a substantially uniform transmittance over almost the entire visible light region. That is, the wire grid polarizing plate according to the present invention has no wavelength dependency of transmittance. In addition, the wire grid polarizing plate according to the present invention showed a high degree of polarization of 99.8 or more at an incident angle of −45 ° and a wavelength of 500 to 800 nm.
また、図６から分かるように、本発明に係るワイヤグリッド偏光板（実施例１）は、ワイヤグリッド偏光板の入射角を−４５°ずらしたＴｐが、８０％以上であった。また、図７から分かるように、本発明に係るワイヤグリッド偏光板（実施例１）は、入射角−６０°から６０°の領域において、４６０ｎｍ、５２５ｎｍ、及び６３０ｎｍそれぞれのＳ波に対して、Ｔｓは０．５％以下であった。 Further, as can be seen from FIG. 6, the wire grid polarizing plate (Example 1) according to the present invention had a Tp of 80% or more when the incident angle of the wire grid polarizing plate was shifted by −45 °. Further, as can be seen from FIG. 7, the wire grid polarizer (Example 1) according to the present invention is for the S waves of 460 nm, 525 nm, and 630 nm in the region of incident angles of −60 ° to 60 °. Ts was 0.5% or less.
本発明に係るワイヤグリッド偏光板（実施例２）は、実施例１と同様に、可視光領域のほぼ全領域にわたってほぼ均一の透過率を示した。さらに、実施例２においては、図１０から分かるように、角度依存性が少なくなった。これは、樹脂基材凹部底部への金属ワイヤの堆積が無くなったことによる効果である。また、図１１から分かるように、入射角−６０°から６０°の領域において、４６０ｎｍ、５２５ｎｍ、及び６３０ｎｍそれぞれのＳ波に対して、Ｔｓは０．２５％以下であった。これも、樹脂基材凹部底部への金属ワイヤの堆積が無くなったことによる効果である。 As in Example 1, the wire grid polarizer (Example 2) according to the present invention exhibited substantially uniform transmittance over almost the entire visible light region. Furthermore, in Example 2, as can be seen from FIG. 10, the angle dependency was reduced. This is an effect due to the fact that the metal wire is no longer deposited on the bottom of the resin substrate recess. Further, as can be seen from FIG. 11, Ts was 0.25% or less for S waves of 460 nm, 525 nm, and 630 nm in the region of incident angles from −60 ° to 60 °. This is also an effect due to the fact that the metal wire is no longer deposited on the bottom of the resin substrate recess.
一方、比較例のワイヤグリッド偏光板は、図４に示すように、入射角４５°において、可視光領域の短波長側及び長波長側で透過率が低く、波長５００ｎｍ付近でピークを持っていた。すなわち、比較例のワイヤグリッド偏光板は、透過率の波長依存性を有していた。これは、金属ワイヤ軸と、格子状凸部軸とがずれていない形状を有していたためであると考えられる。 On the other hand, as shown in FIG. 4, the wire grid polarizing plate of the comparative example had a low transmittance on the short wavelength side and the long wavelength side of the visible light region at an incident angle of 45 °, and had a peak near the wavelength of 500 nm. . That is, the wire grid polarizing plate of the comparative example had wavelength dependency of transmittance. This is considered to be because the metal wire axis and the grid-like convex part axis had a shape that was not shifted.
このように、本発明に係るワイヤグリッド偏光板は、金属ワイヤ軸と、格子状凸部軸とがずれている形状を有しているので、可視光領域の広帯域にわたって優れた偏光度と透過率を両立することができる。 As described above, the wire grid polarizing plate according to the present invention has a shape in which the metal wire axis is shifted from the lattice-shaped convex axis, so that the degree of polarization and transmittance are excellent over a wide band in the visible light region. Can be achieved.
本発明は上記実施の形態に限定されず、種々変更して実施することが可能である。例えば、上記実施の形態における寸法、材質などは例示的なものであり、適宜変更して実施することが可能である。また、上記実施の形態における偏光板については、板状の部材である必要はなく、必要に応じてシート状、フィルム状であっても良い。上記実施の形態においては、ワイヤグリッド偏光板を液晶表示装置に適用した場合について説明しているが、本発明は偏光が必要とされる液晶表示装置以外のデバイスなどに同様に適用することができる。その他、本発明の範囲を逸脱しない限りにおいて適宜変更して実施することが可能である。 The present invention is not limited to the embodiment described above, and can be implemented with various modifications. For example, the dimensions, materials, and the like in the above-described embodiment are illustrative, and can be changed as appropriate. Moreover, the polarizing plate in the said embodiment does not need to be a plate-shaped member, and may be a sheet form and a film form as needed. In the above embodiment, the case where the wire grid polarizing plate is applied to a liquid crystal display device has been described. However, the present invention can be similarly applied to devices other than the liquid crystal display device that requires polarized light. . In addition, various modifications can be made without departing from the scope of the present invention.
１ 樹脂基材
１ａ 格子状凸部
１ｂ 凹部
１ｃ 側面
２ 誘電体層
３ 金属ワイヤ
Ｈ１ 誘電体被覆格子状凸部の底部から金属ワイヤ頂部までの高さ
Ｈ２ 誘電体被覆格子状凸部の底部から頂部までの高さ
Ｈ３ 金属ワイヤの底部から頂部までの高さ
Ａ 金属ワイヤ軸
Ｂ 格子状凸部１ａの頂部を通り、格子状凸部１ａの立設方向に沿う格子状凸部軸
Ｄ 金属ワイヤ軸と格子状凸部軸との間のずれ量
ｔ 誘電体被覆格子状凸部の頂部高さにおける金属ワイヤの幅
ＷＨ 誘電体被覆格子状凸部の底部から３分の２の高さにおける幅
ＷＭ 誘電体被覆格子状凸部の底部から２分の１の高さにおける幅
ＷＬ 誘電体被覆格子状凸部の底部から３分の１の高さにおける誘電体被覆格子状凸部
の幅
２１ 照明装置
２２ ワイヤグリッド偏光板
２３ 液晶パネル
２４ 偏光板
θ 入射角
DESCRIPTION OF SYMBOLS 1 Resin base material 1a Lattice-like convex part 1b Recessed part 1c Side surface 2 Dielectric layer 3 Metal wire H 1 Height from the bottom of a dielectric covering grid | lattice-like convex part to the top of a metal wire H 2 Bottom part of dielectric-coated lattice-like convex part through the top of the height a metal wire axis B grid-shaped convex portions 1a of the bottom of the height H 3 metal wires to the top to the top from the grid-shaped convex portions axis D along the standing direction of the grid-shaped convex portions 1a Deviation amount between metal wire axis and grid-like convex axis t Metal wire width at top height of dielectric-covered grid-like convex part WH Height of two-thirds from bottom of dielectric-coated grid-like convex part Width at WM Width at half height from bottom of dielectric-covered grid-like convex part WL Width of dielectric-covered grid-like convex part at one-third height from bottom of dielectric-covered grid-like convex part 21 Illumination Device 22 Wire Grid Polarizer 23 Liquid Crystal Panel 24 Polarization Plate θ angle of incidence
Claims (11)
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| JP2009203975A JP2010085990A (en) | 2008-09-03 | 2009-09-03 | Wire grid polarizing plate |
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| JP2008225595 | 2008-09-03 | ||
| JP2009203975A JP2010085990A (en) | 2008-09-03 | 2009-09-03 | Wire grid polarizing plate |
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Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011121878A1 (en) | 2010-04-02 | 2011-10-06 | Canon Kabushiki Kaisha | Tank and printer including tank |
| JP2011227243A (en) * | 2010-04-19 | 2011-11-10 | Asahi Kasei E-Materials Corp | Wire grid polarization plate and its manufacturing method |
| JP2012048225A (en) * | 2010-07-30 | 2012-03-08 | Asahi Kasei E-Materials Corp | Wire grid polarization plate and polarization beam splitter using the same |
| JP2012108468A (en) * | 2010-10-25 | 2012-06-07 | Asahi Kasei E-Materials Corp | Wire grid polarization plate |
| JP2016027418A (en) * | 2011-10-14 | 2016-02-18 | 旭化成イーマテリアルズ株式会社 | Wire grid polarizing plate and projection type image display apparatus |
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Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002311382A (en) * | 2001-04-19 | 2002-10-23 | Matsushita Electric Ind Co Ltd | Illumination optical device and projective display device |
| JP2003344651A (en) * | 2002-05-22 | 2003-12-03 | Nippon Sheet Glass Co Ltd | Thin-film structure and thin-film polarizer using the same |
| JP2004045672A (en) * | 2002-07-11 | 2004-02-12 | Canon Inc | Polarized light separating element, and optical system using the same |
| JP2006126338A (en) * | 2004-10-27 | 2006-05-18 | Nippon Sheet Glass Co Ltd | Polarizer and its manufacturing method |
| JP2006308668A (en) * | 2005-04-26 | 2006-11-09 | Ricoh Co Ltd | Fine pattern-formed plastic film and method of forming embedded fine pattern |
| JP2007148344A (en) * | 2005-10-27 | 2007-06-14 | Sony Corp | Polarizing element and its manufacturing method |
| WO2007097454A1 (en) * | 2006-02-27 | 2007-08-30 | Zeon Corporation | Film having fine uneven shape and method for manufacturing same |
| JP2008083657A (en) * | 2005-10-17 | 2008-04-10 | Asahi Kasei Corp | Wire grid polarizer and liquid display device using the same |
| JP2008083656A (en) * | 2005-10-17 | 2008-04-10 | Asahi Kasei Corp | Method of manufacturing wire grid polarizer |
| JP2008181113A (en) * | 2006-12-27 | 2008-08-07 | Toray Ind Inc | Reflection type polarizer and liquid crystal display device |
| JP2008181112A (en) * | 2006-12-26 | 2008-08-07 | Toray Ind Inc | Reflection type polarizer, method of manufacturing the same and liquid crystal display device using the same |
-
2009
- 2009-09-03 JP JP2009203975A patent/JP2010085990A/en active Pending
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002311382A (en) * | 2001-04-19 | 2002-10-23 | Matsushita Electric Ind Co Ltd | Illumination optical device and projective display device |
| JP2003344651A (en) * | 2002-05-22 | 2003-12-03 | Nippon Sheet Glass Co Ltd | Thin-film structure and thin-film polarizer using the same |
| JP2004045672A (en) * | 2002-07-11 | 2004-02-12 | Canon Inc | Polarized light separating element, and optical system using the same |
| JP2006126338A (en) * | 2004-10-27 | 2006-05-18 | Nippon Sheet Glass Co Ltd | Polarizer and its manufacturing method |
| JP2006308668A (en) * | 2005-04-26 | 2006-11-09 | Ricoh Co Ltd | Fine pattern-formed plastic film and method of forming embedded fine pattern |
| JP2008083657A (en) * | 2005-10-17 | 2008-04-10 | Asahi Kasei Corp | Wire grid polarizer and liquid display device using the same |
| JP2008083656A (en) * | 2005-10-17 | 2008-04-10 | Asahi Kasei Corp | Method of manufacturing wire grid polarizer |
| JP2007148344A (en) * | 2005-10-27 | 2007-06-14 | Sony Corp | Polarizing element and its manufacturing method |
| WO2007097454A1 (en) * | 2006-02-27 | 2007-08-30 | Zeon Corporation | Film having fine uneven shape and method for manufacturing same |
| JP2008181112A (en) * | 2006-12-26 | 2008-08-07 | Toray Ind Inc | Reflection type polarizer, method of manufacturing the same and liquid crystal display device using the same |
| JP2008181113A (en) * | 2006-12-27 | 2008-08-07 | Toray Ind Inc | Reflection type polarizer and liquid crystal display device |
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011121878A1 (en) | 2010-04-02 | 2011-10-06 | Canon Kabushiki Kaisha | Tank and printer including tank |
| JP2011227243A (en) * | 2010-04-19 | 2011-11-10 | Asahi Kasei E-Materials Corp | Wire grid polarization plate and its manufacturing method |
| JP2012048225A (en) * | 2010-07-30 | 2012-03-08 | Asahi Kasei E-Materials Corp | Wire grid polarization plate and polarization beam splitter using the same |
| JP2012108468A (en) * | 2010-10-25 | 2012-06-07 | Asahi Kasei E-Materials Corp | Wire grid polarization plate |
| JP2017173832A (en) * | 2011-10-14 | 2017-09-28 | 旭化成株式会社 | Wire grid polarizer, projection type image display device, and manufacturing method for wire grid polarizer |
| US9726929B2 (en) | 2011-10-14 | 2017-08-08 | Asahi Kasei E-Materials Corporation | Wire grid polarizing plate and projection type image display device |
| JP2016027418A (en) * | 2011-10-14 | 2016-02-18 | 旭化成イーマテリアルズ株式会社 | Wire grid polarizing plate and projection type image display apparatus |
| JP2019507372A (en) * | 2015-12-30 | 2019-03-14 | コーロン インダストリーズ インク | Wire grid polarizer and optical component including the same |
| US10672427B2 (en) | 2016-11-18 | 2020-06-02 | Wostec, Inc. | Optical memory devices using a silicon wire grid polarizer and methods of making and using |
| US11037595B2 (en) | 2016-11-18 | 2021-06-15 | Wostec, Inc. | Optical memory devices using a silicon wire grid polarizer and methods of making and using |
| US11308987B2 (en) | 2016-11-18 | 2022-04-19 | Wostec, Inc. | Optical memory devices using a silicon wire grid polarizer and methods of making and using |
| US11371134B2 (en) | 2017-02-27 | 2022-06-28 | Wostec, Inc. | Nanowire grid polarizer on a curved surface and methods of making and using |
| WO2019066674A1 (en) * | 2017-09-27 | 2019-04-04 | Wostec, Inc. | Optical devices with nanowire grid polarizer on a curved surface and methods of making and using |
| JP2018189980A (en) * | 2018-07-19 | 2018-11-29 | デクセリアルズ株式会社 | Polarizing plate |
| WO2020017455A1 (en) * | 2018-07-19 | 2020-01-23 | デクセリアルズ株式会社 | Polarizer |
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