201241487 六、發明說明： 【發明所屬之技術領域】 本發明關於一種穿透光的漫射性根據入射角而變化 的異向漫射性光學膜。 【先前技術】 具有光漫射性的零件自古以來不僅使用在照明器具 和建材，最近也廣泛應用在顯示器上，特別是在LCD。這 些光漫射零件的光漫射機構可舉出：表面上形成的凹凸所 引起的散射（表面散射）、基體樹脂和其中分散的填料之間 的折射率差所引起的散射（内部散射）、以及表面散射和内 部散射共同引起的散射。然而，這些光漫射零件通常情況 下其漫射性能是同向的’即使稍稍變化入射角度，其穿透 光的漫射特性也不會有大的差異。 (具有板狀結構的類型A) 已知有在一定角度範圍内的入射光會強烈漫射、而其 他角度的入射光則會穿透的光控制板（住友化學販售、商品 名“Lumisty” 。例如專利文獻丨）。該光控制板是從片狀 的感光性組合物層的上方使用線狀光源照射平行光而固化 得到者。而且認為在片狀的基體内，如第15圖所示，在製 作光學膜50時與在其上方配置的線狀光源51的長度方向 一致、並與周邊區域及折射率不同的板狀結構40相互平行 地形成（以下簡稱為類变A)。如第16圖所示，在未有圖示 的光源和光接收器3之間配置樣品’以樣品表面的直線L 為中心軸，可一邊變化角度一邊直進穿透樣品，並測定進 323902 4 201241487 入光接收器3的直線穿透率。 第17圖表示使用第16圖中所示方法而測定第15圖 中所示類型A的光學膜50所具有的散射特性的入射角依存 性。縱軸表示表徵散射程度的指標的直線穿透率（在入射規 定光量的平行光線時，在與入射方向相同的方向上出射的 平行光線的光量）；橫軸表示入射角。第17圖中的實線和 虛線分別表示以第15圖中的A-A軸（穿過板狀結構）以及 B-B軸（平行於板狀結構）為中心旋轉光學膜50的情況。另 外，入射角的正負表示旋轉光學膜50的方向是相反的。第 Π圖中的實線無論正面方向或者斜方向直線穿透率都很 小，這也就代表在以A-A軸為中心進行旋轉時，光學膜50 的散射狀態與入射角沒有關係。另外，第17圖中的虛線在 0°附近的方向上直線穿透率變小，但這也就代表在以B-B 軸為中心進行旋轉的情況下，光學膜對於正面方向的光是 散射狀態。再者，在入射角大的方向上直線穿透率增加， 但這代表在以B-B軸為中心進行旋轉的情況下，光學膜對 於斜方向的光是穿透狀態。因為該結構所以可以提供例如 雖在橫向上穿透度根據入射角的大小而不同，但在縱向上 即使改變入射角穿透度也沒有變化之特性。此處，如第17 圖般表示散射特性的入射角依存性的曲線，以下稱為“光 學曲線”。雖然光學曲線並不直接地表現散射特性，但是 如果解釋為因直線穿透率降低而相反地谩射穿透率增大， 就可略顯示漫射特性。 (具有柱狀結構的類型B) 323902 5 201241487 另一方面，雖然光漫射性具有入射角依存性，但已提 出如第18圖所示般具有沿著膜的厚度方向（膜的法線方向 P)延伸存在的柱狀結構62的光學膜60(以下簡稱為類型B) (例如’專利文獻2)。該柱狀結構是藉由在感光性組合物 層上照射平行的UV光，而在感光性組合物層中平行於光的 前進方向上形成。在該類型B的光學膜中，表徵在改變入 射角時直線穿透率的變化的光學曲線示於第19圖。在以 A-A為旋轉中心軸的情況下和在以b_b為旋轉中心軸的情 況下’如果改變入射角來測定其直線穿透率，則在任何一 種情況下都能夠得到同樣的光學曲線。即第18圖的光學膜 即使旋轉中心軸改變，也表現出略相同的直線穿透率，與 在法線方向（〇。）入射時的穿透率相比較，在±5至1〇。的入 射角直線穿透率暫時達到極小值，隨著其入射角的增大直 線穿透率也增大’在±45至60。的入射角直線穿透率達到極 大值。 如更詳細說明有關於該等類型A以及類型B，則在内 部存在有折射率高低不同的微細結構，且穿透的入射光的 直線穿透率因入射角不同的光學膜之情形，其光學特性由 内部結構的類型和該結構物的傾斜度而規定。例如，如前 述類型A般，在内部由折射率不同的微細結構以板狀結構 形成的光學膜之情形，其光學特性根據對於該板狀結構之 膜的法線的傾斜度而規定。另一方面，如前述類型B般， 具有在膜的厚度（法線）方向上延伸的柱狀結構的光學膜之 情形，光學特性根據該柱狀結構相對於膜的法線的^斜产 323902 201241487 而規定。類型A的光學膜之情形，從略平行於板狀結構的 方向入射的入射光被強烈漫射，且貫穿該板狀結構的入射 % 光幾乎不漫射地穿透，因此板狀結構可說是光散射面。另 * 一方面，類型B的光學膜之情形’柱狀結構是在感光性組 合物層上照射平行的UV光時，在平行於該光的前進方向上 形成者，如果對感光性組成物層從其法線方向照射平行UV 光，則柱狀結構會沿著法線方向延伸存在。在這種情況下， 結果就是（UV光的照射方向=柱狀結構的延伸存在方向=法 線方向），如第19圖所示’所有入射面内的光的入射角度 和直線穿透率的關係以法線為中心呈對稱形狀，因此可認 為該法線就是散射中心軸。下面使用圖而更加詳細的說明 該散射中心軸° 第20圖表示類塑B的光學膜的微細結構的截面示意 圖。微細柱狀結構物沿著片材的法線方向延伸存在。此處， 網點部分的區域和空白的區域表示折射率的高低β該光學 膜的光漫射性可用第21圖所示方法簡便地調查。即，如果 在白紙的上方留出一定的間隔平行地固定光學膜，並以光 學膜的特定的區域為入射點而從上方入射雷射指標般的強 平行光線，那麼穿透光的漫射狀態就在白紙上映射出來。 此處，從法線方向來的入射光在白紙上投影為呈圓形的漫 射光，另一方面從斜方向來的入射光在與剛才圓形漫射光 相偏離的位置上呈現出月牙狀的投影光。改變入射光的傾 斜度和其方位時白紙上投影的漫射光的形狀如第22圖所 示，但此處可知如果從法線方向開始慢慢傾斜入射光，那 323902 7 > 201241487 麼傾斜的角度越大月牙形越細，如果以相同的傾斜角而改 變入射的方位，那麼形狀相同而月牙的方向會連續變化。 白紙上的投影光顯示為圓形的情況下，連接該圓的中心與 此時對於光學膜的入射點之直線就是散射中心軸，在這種 情況下和法線一致。 另一方面，如果類型B的枉狀構造的延伸存在方向偏 離法線方向，那麼散射中心軸就會與法線方向不一致。這 樣的傾斜柱狀結構係藉由對感光性組合物層而從傾斜方向 照射UV光而形成，但根據斯涅爾定律（Snell’ s law)，UV 光入射方向和平行於穿透感光性組合物層的UV光方向而 形成的柱狀結構的延伸存在方向是未必一致的。另外，根 據UV光照射時的感光性組合物層的溫度條件的不同，柱狀 構造在延伸存在方向上也可能產生雜亂’即使在這樣的情 況下，散射中心軸也可用上述的第21圖的方法來求得。例 如得到第23圖所示漫射圖形的情況下’連接略為圓形狀的 投射光的中心與此時對於光學膜的入射點之直線就是散射 中心軸。另外，在不能夠判別圓形狀的光所形成區域的情 況下，如果以偏離該散射中心軸的角度入射的光漫射成月 牙形狀，那麼第24圖所示般在二分月牙形的直線的延長線 上存在散射中心轴，因此可以從分離的兩個月牙形來求出 散射中心軸的位置。即，連接第24圖中兩條直線的交點與 此時對於光學膜的入射點之直線就是散射中心軸。 另外，同樣用第21圖的方法來測定類型A的板狀結 構的光學膜時，則如第25圖和第26圖。第25圖表示在包 323902 201241487 含膜的法線的方向上形成板狀結構的情況。此處， 鷲 為在沿著X軸方向伸長為橢圓形且Y轴上排列，並:其 ^射角度下幾乎不擴展而為點狀H板狀結構相對 二垂方直二立’並在γ軸方向上延伸。第26圖表示由膜的 、、向傾斜而形成板狀結構的情況。此處，雖然可以看 見伸長的橢圓形的擴展，但該橢圓形在由法線往X軸方向 :離的Yl軸上顯現，如果Yl上的角度變化那麼橢圓的伸展 取向也變化。在這種情況下，板狀結構沿著連接γ,軸與光 于膜的入射點之方向延伸存在。 具有板狀結構的類型A的光學膜例如作為防止窺視的 建材而很有實效，而且在液晶面板中也可以用於擴大視角201241487 VI. Description of the Invention: [Technical Field] The present invention relates to an anisotropic diffusing optical film in which the diffusivity of transmitted light varies depending on an incident angle. [Prior Art] Parts having light diffusibility have not only been used in lighting fixtures and building materials since ancient times, but have recently been widely used in displays, especially in LCDs. The light-diffusing mechanism of these light-diffusing components may be: scattering caused by irregularities formed on the surface (surface scattering), scattering caused by a refractive index difference between the matrix resin and the dispersed filler therein (internal scattering), And scattering caused by surface scattering and internal scattering. However, these light diffusing parts usually have the same diffusing performance as the same. Even if the incident angle is slightly changed, the diffusing characteristics of the transmitted light are not greatly different. (Type A having a plate-like structure) A light control panel in which incident light within a certain angle range is strongly diffused and incident light at other angles is penetrated (Sumitomo Chemical Co., Ltd., trade name "Lumisty") is known. For example, the patent document 丨). The light control plate is obtained by irradiating parallel light from a linear light source from above the sheet-like photosensitive composition layer. Further, in the sheet-like base body, as shown in Fig. 15, when the optical film 50 is produced, the plate-like structure 40 which is different from the longitudinal direction of the linear light source 51 disposed above and which is different from the peripheral region and the refractive index is formed. They are formed in parallel with each other (hereinafter referred to as class change A). As shown in Fig. 16, a sample is placed between the light source (not shown) and the light receiver 3. With the straight line L of the sample surface as the central axis, the sample can be directly penetrated while changing the angle, and measured into 323902 4 201241487 The linear transmittance of the light receiver 3. Fig. 17 is a graph showing the incident angle dependence of the scattering characteristics of the optical film 50 of the type A shown in Fig. 15 by the method shown in Fig. 16. The vertical axis represents the linear transmittance indicating the index of the degree of scattering (the amount of parallel rays emitted in the same direction as the incident direction when incident parallel rays of a predetermined amount of light are incident); the horizontal axis represents the incident angle. The solid line and the broken line in Fig. 17 indicate the case where the optical film 50 is rotated about the A-A axis (through the plate-like structure) and the B-B axis (parallel to the plate-like structure) in Fig. 15 . In addition, the positive or negative angle of incidence indicates that the direction of the rotating optical film 50 is reversed. The solid line in the first diagram has a small straight line penetration rate in either the front direction or the oblique direction, which means that the scattering state of the optical film 50 is not related to the incident angle when rotating around the A-A axis. Further, the broken line in Fig. 17 has a small linear transmittance in the direction around 0°, but this means that the optical film is scattered with respect to the light in the front direction when rotating around the B-B axis. Further, the linear transmittance increases in the direction in which the incident angle is large, but this means that the optical film is in a penetrating state with respect to the oblique direction when the rotation is centered on the B-B axis. Because of this structure, for example, although the degree of penetration in the lateral direction differs depending on the magnitude of the incident angle, there is no change in the longitudinal direction even if the angle of incidence of the incident angle is changed. Here, a curve showing the dependence of the incident angle of the scattering characteristics as shown in Fig. 17 is hereinafter referred to as "optical curve". Although the optical curve does not directly exhibit the scattering characteristics, if it is explained that the sputtering transmittance is increased due to the decrease in the linear transmittance, the diffusion characteristics are slightly displayed. (Type B having a columnar structure) 323902 5 201241487 On the other hand, although the light diffusibility has an incident angle dependency, it has been proposed to have a thickness direction along the film as shown in Fig. 18 (the normal direction of the film) P) An optical film 60 (hereinafter simply referred to as type B) of the columnar structure 62 extending (for example, 'Patent Document 2'). The columnar structure is formed in a direction parallel to the progress of light in the photosensitive composition layer by irradiating parallel UV light on the photosensitive composition layer. In the optical film of this type B, an optical curve characterizing the change in the linear transmittance at the time of changing the incident angle is shown in Fig. 19. In the case where A-A is the central axis of rotation and when b_b is the central axis of rotation, if the incident angle is changed to determine the linear transmittance, the same optical curve can be obtained in either case. That is, the optical film of Fig. 18 exhibits a slightly the same linear transmittance even when the central axis of rotation changes, and is ±5 to 1 比较 as compared with the transmittance at the normal direction (〇). The linear penetration rate of the incident angle temporarily reaches a minimum value, and the linear transmittance increases as the incident angle increases by ±45 to 60. The incident angle has a linear transmittance that reaches a very large value. As described in more detail about the type A and the type B, there are microstructures having different refractive index inside, and the linear transmittance of the incident light that penetrates is due to the optical film having different incident angles, and the optical The characteristics are defined by the type of internal structure and the inclination of the structure. For example, in the case of an optical film in which a fine structure having a different refractive index is formed in a plate-like structure inside, as in the above-described type A, the optical characteristics are defined in accordance with the inclination of the normal to the film of the plate-like structure. On the other hand, as in the case of the above-described type B, there is a case of an optical film having a columnar structure extending in the thickness (normal) direction of the film, and the optical characteristics are based on the normal of the columnar structure with respect to the film. 201241487 and the regulations. In the case of the optical film of the type A, the incident light incident from a direction slightly parallel to the plate-like structure is strongly diffused, and the incident % light penetrating the plate-like structure penetrates almost without diffusion, so that the plate-like structure can be said It is a light scattering surface. On the other hand, in the case of the optical film of type B, the columnar structure is formed in parallel to the direction of advancement of the light when the parallel UV light is irradiated on the photosensitive composition layer, if the photosensitive composition layer is When parallel UV light is illuminated from its normal direction, the columnar structure will extend along the normal direction. In this case, the result is (the direction of irradiation of the UV light = the direction in which the columnar structure extends = the normal direction), as shown in Fig. 19, the incident angle and the linear transmittance of the light in all the incident planes. The relationship is symmetrically centered on the normal, so the normal is considered to be the central axis of the scattering. The scattering center axis will be described in more detail below using a diagram. Fig. 20 is a schematic cross-sectional view showing the microstructure of the optical film of the plastic B. The fine columnar structure extends along the normal direction of the sheet. Here, the area of the halftone dot portion and the blank area indicate the level of the refractive index β. The light diffusibility of the optical film can be easily investigated by the method shown in Fig. 21. That is, if the optical film is fixed in parallel at a certain interval above the white paper, and a strong parallel light of the laser index is incident from above with a specific region of the optical film as an incident point, the diffused state of the transmitted light Just map it on white paper. Here, the incident light from the normal direction is projected as a circular diffused light on the white paper, and on the other hand, the incident light from the oblique direction exhibits a crescent-shaped position at a position deviated from the circularly diffused light. Projection light. The shape of the diffused light projected on the white paper when changing the inclination of the incident light and its orientation is as shown in Fig. 22, but it can be seen that if the incident light is slowly tilted from the normal direction, then 323902 7 > 201241487 The larger the angle, the thinner the crescent shape. If the orientation of the incident is changed at the same tilt angle, the shape is the same and the direction of the crescent changes continuously. In the case where the projection light on the white paper is shown as a circle, the line connecting the center of the circle to the incident point of the optical film at this time is the scattering central axis, in which case it coincides with the normal. On the other hand, if the extension of the braided structure of type B exists in the direction away from the normal direction, the scattering center axis will be inconsistent with the normal direction. Such a slanted columnar structure is formed by irradiating UV light from an oblique direction to a photosensitive composition layer, but according to Snell's law, UV light incident direction and parallel to penetration sensitivity combination The extending direction of the columnar structure formed by the UV light direction of the object layer is not necessarily uniform. Further, depending on the temperature conditions of the photosensitive composition layer at the time of UV light irradiation, the columnar structure may also be disordered in the extending direction. Even in such a case, the scattering central axis can also be used in the above-described FIG. Method to find out. For example, in the case of obtaining the diffused pattern shown in Fig. 23, the line connecting the center of the slightly rounded projection light to the incident point of the optical film at this time is the scattering center axis. Further, in the case where it is not possible to discriminate the region in which the circular shape is formed, if the light incident at an angle deviating from the scattering central axis is diffused into a crescent shape, the extension of the bifurcated line as shown in Fig. 24 is extended. There is a scattering center axis on the line, so the position of the scattering center axis can be obtained from the separated two crescent shapes. That is, the line connecting the intersection of the two straight lines in Fig. 24 and the incident point to the optical film at this time is the scattering central axis. Further, when the optical film of the plate-like structure of the type A is also measured by the method of Fig. 21, it is as shown in Fig. 25 and Fig. 26. Fig. 25 shows a case where a plate-like structure is formed in the direction of the normal of the film containing 323902 201241487. Here, 鹫 is elongated in an elliptical shape along the X-axis direction and arranged on the Y-axis, and has a point-like H-plate-like structure that is almost non-expanded at a certain angle of incidence. Extending in the axial direction. Fig. 26 shows a case where a plate-like structure is formed by tilting the film. Here, although the expansion of the elongated ellipse can be seen, the ellipse appears on the Y1 axis from the normal to the X-axis direction, and if the angle on Y1 changes, the orientation of the ellipse also changes. In this case, the plate-like structure extends along the direction of the connection γ, the axis and the incident point of the film. The optical film of the type A having a plate-like structure is effective as, for example, a building material for preventing peeping, and can also be used for expanding the viewing angle in a liquid crystal panel.
〇提高能見度的目的。另一方面，具有柱狀結構的類型B 的光學膜也同樣可以使用在液晶顯示面板的用途上，此外 定提出了應用在投影用屏幕。如果在液晶顯示面板上使用 異向性漫射膜，那麼可以根據用途來選定與目標視角相符 〇的類型。但是，實際上類型A中只擴大一的方位角方向 的現角，在與其正交的方位角方向上，視角幾乎沒有擴大。 [技術文獻] ' (專利文獻） 專利文獻1 :日本特許第2547417號公報 專利文獻2 :日本特開平2007-114756號公報 【發明内容】 (發明要解決的課題） 類型A之情形改變光的入射角度時漫射性的變化是極 323902 201241487 其迅速的，因此將其應用於面板時視認性會表現出急劇變 化，會帶來不自然的感覺。另一方面，類型B中雖然在全 方位上擴大為略相等的視角，但是在有一部分的方向（例如 水平方向）上想要進一步擴大視角的要求無法得到滿足，而 且若擴大漫射角度則正面亮度會降低。為了改善這些問 題，雖也有與其他的擴散膜組合使用的提案，但是從成本 要求和製造程序簡略化的角度來看，尋求用一個光學膜就 具有這些光學膜之中間的光學特性的方案。因此，本發明 的目的在於立足於以上的現有技術，而提供一種同時具有 上述類型A和類型B的性質的光學膜。 (解決課題的手段） 本發明（1)係一種光學膜，其係在内部存在有折射率 高低不同的微細結構、且穿透之入射光的直線穿透率因入 射角的不同而不同的光學膜，其中， 該光學膜具有從散射中心軸入射的圓形光在相對於 與平行前述光學膜的平面投影為橢圓形的性質； 從散射中心軸入射的光的散射特性如下： 在與前述橢圓形的長軸方向平行的方向之光學膜平 面上的X軸、與前述散射中心軸所形成的平面内，出射角 度與該出射角度時的漫射穿透率之間的關係設為關係Tx， 垂直於前述X軸的光學膜平面上的Υ軸、與前述散射 中心軸所形成的平面内，出射角度與該出射角度時的漫射 穿透率之間的關係設為關係Ty， 前述關係Tx中，漫射穿透率的峰的最大值的十分之 323902 10 ⑧ 201241487 一值為峰寬Fmaxl/lOX，與前述關係Ty中’度射穿透率的峰 、 的最大值的十分之一值的峰寬Fraaxl/ioy滿足下述式（1 )的關 係， 1. 5 < Fmaxl/l〇X / Fmaxl/ioy < 4. 5 (1)。 本發明（2)係上述發明（1)的光學膜’其特徵在於，前 述X軸與前述散射中心軸所形成的平面内’光的入射角度 與直線穿透率的關係為： 直線穿透率的極大值Fa(%)以及取該極大值的角度 A(°)、與直線穿透率的極小值Fb(%)以及取該極小值的角 度B(°)滿足下述式（2)的關係， 0. 70<(Fa-Fb)/ | A-B | <2.0 (2)。 本發明（3)係上述發明（1)或（2)的光學膜，其特徵在 於，前述微細結構出現在與前述光學膜的X軸和散射中心 軸所形成的平面平行的截面、以及與前述光學膜的γ軸和 散射中心軸所形成的平面平行的截面上。 本發明（4)係上述發明（3)的光學膜，其特徵在於，前 述光學膜的與X軸-散射中心軸平面平行的截面上的前述 微細結構的密度’高於與γ軸-散射中心轴平面平行的截面 上的前述微細結構的密度。 (發明效果） 根據本發明（1)，因為在内部具有折射率高低不同的 微細結構，所以本發明的光學膜可使穿透的入射光的直線 穿透率因入射角不同而異。而且，從散射中心軸入射的圓 形光相對於平行於光學膜的平面投影成橢圓形。帶來在橢 323902 201241487 圓的長軸方向上光強烈漫射，且在與長軸正交的短軸方向 上光微弱漫射的效果。進一步地，同時兼具了前述類型A 的板狀結構和前述類型B的柱狀結構的兩種結構的特性， 帶來了必須使用以前的兩層以上的不同的異向性漫射膜才 能夠得到的特性。具體來說，因在必要方向上進行優先的 光漫射，故能夠實質提升光的利用效率。 根據本發明（2)，在改變光的入射角度時漫射性的變 化與目前已知的類型A相比是平緩的，因此，將其應用於 面板時視認性不會有急劇變化，可給予觀察者更自然的印 象。 根據本發明（3)，從散射中心軸入射的圓形光相對於 與光學膜平行的平面為橢圓形，而且在X軸和散射中心轴 形成的平面、以及Y軸與散射中心軸形成的平面上形成有 微細的結構，因此，向X軸方向的散射與向Y軸方向的散 射可同時進行，並且可具有向X軸方向的漫射程度與向Y 軸方向的漫射程度不同的性質。 根據本發明（4)，由於微細結構的密度根據X軸方向、 Y軸方向不同而有所差異，所以根據照射光的方向不同， 光的漫射也有所差異。 【實施方式】 在此說明本專利申請範圍及本說明書中的各個用語 的定義。 所謂“折射率高低不同的微細結構”，是指根據構成 光學膜的材料之局部的折射率高低差而形成的結構。例 323902 12 201241487 如’第8圖是關於實施例3的光學膜。如第8圖所示，該 ' 微細結構是在截面中以光學方式觀測到的結構。推測這些 * 結構為形成光學膜的材料在固化時形成的，例如藉由調整 密度高低的差而形成的結構。 所謂“散射中心軸”代表在改變入射角時，散射特性 係該入射角與在邊境具有大致對稱性的光之入射角為—致 的方向。其中，之所以要具有大致對稱帙，是因為在散射 中心軸相對於膜面的法線方向具有傾斜的情況下，下述的 光學性質等沒有嚴密的對稱性。散射中心轴係藉由如後述 般，在改變入射角的情況下觀察穿過光學膜的圓形狀的光 的投影形狀而找出。以下說明有關於散射中心軸。在前面 已使用第21圖到第26圖說明了散射中心轴空間位置的確 疋方式，但如果已知由所得到散射中心車由的傾斜的方位角 方向，並測定其和法線形成的平面内的光學曲線，就能夠 得到散射中心軸的正確的傾斜角。在該光學曲線中，散射 中心軸可用夾在兩個極小值中間的極大值所對應的入射角 度來表示。第1圖以及第2圖是概念性地表示各種光學曲 線以及散射中心軸的圖。首先，第丨圖是在膜的法線方向 上照射UV光而製作的光學膜’整體形狀是左右大致對稱的 光學曲線（W型）。與〇度一致的粗縱線是與此時散射中心 軸一致的入射角。第2圖是從不同於膜的法線方向照射uv 光而製作的光學膜，是整體形狀不左右對稱的光學曲線 型）。在此’穿過夾在兩個極小值之間的極大值Fc的粗豎 線也是與此時散射中心轴一致的入射角。如此，在任一情 323902 13 201241487 況下散射中心軸都藉由首先都著眼於大致對稱的大的谷區 域’然後確定該谷區域的中心而決定。此處，第1圖以及 第2圖的情況下，該谷區域在左右包含極小值，在這些極 小值之間包含極大值。這樣，該極大值的位置就是散射中 心軸。另外’在光學曲線並不是具有夾在兩個極小值之間 的極大值的W型，而是在大的谷區域上幾乎看不見極大值 的U型的情況下’可以將到兩側的谷的傾斜面略為等距離 之谷底的平坦部分的中央附近定義為散射中心軸。另外， 在光學曲線呈現為V型的情況下，可以將其谷中央最深處 定義為散射中心轴。 直線穿透率係關於對光學膜入射的光的直線穿透性， 是在從某一入射角入射時，直線方向的穿透光量與入射光 的光量的比例如下式所示。 直線穿透率（％) = (直線穿透光量/入射光量）χ1〇〇 本發明是在内部存在有折射率高低不同的微細結構、 穿透的入射光的直線穿透率因入射角而異的光學犋。即， ^有異向漫射性的光學f本發明的光學膜，提供了介於 則述類型A的板狀結構與前述_ B的柱狀結樽所具有的 性質之間的性質。以下，通過第_形態以及第二形態來說 明本發明的内容。 心 (第一形態） ，在第一形態中，以散射中心軸與光學膜的法線方向平 仃的情況為例說明本發明的内容。第3圖是用以說明本發 明的光學膜的光學特性的概念圖。在第3圖中，1是本發 323902 201241487 明的光學膜，2是與光學膜平行的平面。如第3圖所示， 本發明的光學膜具有從散射中心軸位置P處入射的圓形 光，會在與前述光學膜平行的平面2上被投影成橢圓形之 性質。此處，圓形光是指垂直截面的形狀是圓形狀的光。 作為圓形光並沒有特別的限定，例如可以舉出雷射指標 (laser pointer)等的雷射。 投射在平行平面2上的擴圓形的光具有長轴A-A’和 短軸B-B’ 。該橢圓形是圓形光在X軸方向上被漫射並穿 透從而在長軸A-A’方向上擴展、圓形光在Y軸方向上被 漫射從而在短軸B-B’方向上擴展，投影而形成的形狀。 即，所謂投影成橢圓形的意思是，向光學膜的X軸方向和 Y軸方向的漫射的程度是不同的。如此，不僅具有因方向 引起的漫射性的區別，在本發明中，在短軸B-B’方向上 也可以觀察到一定的光漫射。 第4圖表示如本形態的光學膜般，散射中心軸位於法 線方向的情況下的散射特性。即，第4圖是表示第3圖中 穿透P點的光，在改變入射角的情況下，投射在平面2上 的光的形狀的圖。由於本發明的光學膜的目標是介於上述 板狀結構與棒狀結構中間的光學特性，所以具有在棒狀結 構時已說明的散射中心軸。如第4圖所示，中央的漫射形 狀呈橢圓形。這樣形成中央的漫射形狀的入射角與散射中 心軸是一致的。不過，比第25圖中所示的橢圓更圓，斜入 射光的漫射形狀也呈現出介於第22圖的月牙形和第25圖 的橢圓形的中間的形狀。如上所說明般，即使不知道製造 323902 15 201241487 上的uv光的照射方向，只使用類似雷射指標般簡單裝置， 就可以找出光學膜的散射中心軸。另外，在 中心轴的情況下，應用第.24圖所示的方法，因為=2 . 軸位於二分月牙形的直線的延長線上，所以可以從分開的， 兩個月牙形來求出散射中心軸的位置。 在本發明中，從散射中心轴入射的光其散射特性表現 出特別顯著的特徵。 表示X軸方向的散射特徵的關係Τχ與表示γ軸方向 的散射特性的關係Ty的峰寬的關係滿足規定的關係。即， 前述關係Τχ中的漫射穿透率的峰的最大值的十分之一的 值的峰寬FmaxmoX和前述關係Ty中的漫射穿透率的峰的最 大值的十分之一的值的峰寬Ffflaxlmy，滿足下式（1)的關係。 1 · 5 < Fmaxl/l〇X / Fmaxl/l〇y〈 4· 5 ( 1 ) 峰寬Fmi/u反映光學膜的散射特性。藉由把峰寬的比 調整在這樣的範圍内，而適度調整χ軸方向和γ軸方向上 散射特性的差異。 此處，關係Τχ是指光學膜平面上的χ軸與前述散射 中心軸所形成的平面内的出射角度、與該出射角度的漫射 穿透率之間的關係。 另一方面，關係Ty是指光學膜平面上的γ軸與前述 散射中心軸所形成的平面内的出射角度與該出射角度的漫 射穿透率之間的關係。 ^ 又 在本發明中，特別是滿足下述的特性者更為適合。 2· 0 < Fmaxl/IQX / Fmaxm〇y〈 3· 〇 323902 ⑧ 16 201241487 關於在本發明的光學膜的散射特性’使用測角光度計 (goriiophotometer)，用第6圖所示的方法進行評價。將光 照射在本發明的光學膜上，測定從膜出射的光的穿透率。 % 以光源為中心，沿著X方向（紙面中的上下方向）、Y方向（紙 面的近至遠的方向）旋轉光接收器而進行測定。 第7圖表示下述實施例2的光學膜的散射特性。在第 7圖中，橫軸表示相對於光學膜的檢測器的角度，且縱轴 表示下述定義的穿透率。 漫射穿透率=(檢測器的檢出光量/在無光學膜條件下’ 在光源的正面配置檢測器時的檢出光量）χ100 在第7圖中’用虛線表示在X軸和散射中心轴形成的 平面内的出射角度與該出射角度的漫射穿透率的關係Τχ (X軸方向）、用實線表示在γ轴和散射中心轴形成的平面 内的出射角度與該出射角度的漫射穿透率的關係Ty(Y轴 方向）° Fmaxl/1()X是，關係τχ的漫射穿透率的峰的最大值（X 軸maX)的十分之一的值（X軸maxl/10)對應的峰寬。另一 方面Fmaxl/1°y是，關係Ty的漫射穿透率的峰的最大值（Y # maX)的十分之—的值（X軸maxl/lG)對應的峰寬。 再者’在本發明的光學膜中，前述X軸與前述散射中 :轴形成的平面内’光的入射角度與直線穿透率（％)的關係 係直線穿透率的極大值Fa⑻以及取該極大值的角度 A()與直線穿透率的極小值Fb(%)以及取該極小值的角 度B〇滿足下述式⑵的關係， : °*70<(Fa-Fb)/ I a-B I <2.0 ⑵。 323902 17 201241487 通過滿足上述雜，直線穿料的角度依存性得到緩 口^如用於顯示器的情況下，可以解決因角度變化所引 起里質的急劇變化的問題。 在本發明中，特別適合為滿足下述的特性者。 0. 90< (Fa~Fb)/ | Α-β I <1.7 其中角度A以及B的意思是相對於光學膜的法線的 角度，至於其關係’回到第！圖，詳細說明本發明的光學 膜中光的入射角度與直線穿透率的關係（光學曲線）。本發 明的光學膜的光學曲線為以散射中心軸為中心，形成左右 略對稱的曲線。該曲線具有三個極大值和兩個極小值。即， 如果變化入射角度來測定直線穿透光，那麼在兩個地方分 別具有極小值FB1* Fm(另外，把極小值Fbi對應的入射角 度§己為Βι ’把極小值&對應的入射角度記為b2)。該極小 值所夾的位置上存在比較小的極大值Fc。該極大值的入射 角與政射中心軸一致。在該極大值p*c的兩侧，存在由極小 值FB1* Fm夾著的極大值fa1*極大值FA2(另外，把極大值 Fm對應的入射角度記為Ai，把極大值FA2對應的入射角度 記為A2)。 對於式（2)中的關係，在兩種的極大值（FA1* FA2)以及 極小值（Fbi和Fb2)中，把下述（a)(b)之中的值較大的那組 記為Fa以及A、Fb以及B。〇 Improve the purpose of visibility. On the other hand, an optical film of type B having a columnar structure can also be used for the use of a liquid crystal display panel, and is also proposed to be applied to a projection screen. If an anisotropic diffuser is used on the LCD panel, the type that matches the target angle of view can be selected according to the application. However, in fact, in the type A, only the angle of the azimuth direction of one is expanded, and the angle of view is hardly enlarged in the azimuth direction orthogonal thereto. [Technical Document] [Patent Document] Patent Document 1: Japanese Patent No. 2,574,714, Patent Document 2: JP-A-2007-114756 SUMMARY OF INVENTION (Problems to be Solved by the Invention) The case of Type A changes the incidence of light. The change in diffusivity at the angle is extremely fast, 323902 201241487, so when applied to a panel, the visibility will show a sharp change, which will bring an unnatural feeling. On the other hand, although the type B is expanded to a slightly equal angle of view in all directions, the requirement to further expand the angle of view in a part of the direction (for example, the horizontal direction) cannot be satisfied, and if the diffusion angle is enlarged, the front is positive. The brightness will decrease. In order to improve these problems, there are proposals for use in combination with other diffusion films. However, from the viewpoint of cost requirements and simplification of the manufacturing process, it has been desired to use an optical film to have optical characteristics in the middle of these optical films. Accordingly, it is an object of the present invention to provide an optical film having the properties of both Type A and Type B described above, based on the above prior art. (Means for Solving the Problem) The present invention (1) is an optical film in which a fine structure having a different refractive index is present inside and an optical transmittance of incident light that penetrates is different depending on an incident angle. a film, wherein the optical film has a circular light incident from a scattering central axis and has an elliptical shape projected with respect to a plane parallel to the optical film; a scattering characteristic of light incident from a scattering central axis is as follows: The relationship between the exit angle and the diffuse transmittance at the exit angle in the plane formed by the X-axis on the optical film plane in the direction parallel to the long axis direction of the shape, and the diffuse transmittance at the exit angle is set as the relationship Tx, The relationship between the exit angle and the diffuse transmittance at the exit angle in a plane perpendicular to the X-axis of the optical film plane and the plane formed by the scattering center axis is defined as a relationship Ty, the relationship Tx The maximum value of the peak of the diffuse transmittance is 323902 10 8 201241487 One value is the peak width Fmaxl/lOX, which is one tenth of the maximum value of the peak of the 'radiation transmittance' in the relationship Ty The peak width Fraaxl/ioy of the value satisfies the relationship of the following formula (1), 1. 5 < Fmaxl / l 〇 X / Fmaxl / ioy < 4. 5 (1). According to a second aspect of the invention, the optical film of the invention (1) is characterized in that the relationship between the incident angle of the light and the linear transmittance in the plane formed by the X-axis and the scattering central axis is: linear transmittance The maximum value Fa (%) and the angle A (°) taking the maximum value, the minimum value Fb (%) of the linear transmittance, and the angle B (°) taking the minimum value satisfy the following formula (2) Relationship, 0. 70 < (Fa-Fb) / | AB | <2.0 (2). The optical film according to the invention (1) or (2), characterized in that the fine structure is formed in a cross section parallel to a plane formed by the X-axis and the scattering central axis of the optical film, and The plane of the optical film is parallel to the plane formed by the gamma axis and the scattering central axis. The optical film according to the invention (3), characterized in that the density of the fine structure in the cross section parallel to the X-axis-scattering central axis plane of the optical film is higher than that of the γ-axis-scattering center. The density of the aforementioned fine structure on a section parallel to the axis plane. (Effect of the Invention) According to the invention (1), since the optical structure having different refractive index is different inside, the optical film of the present invention can make the linear transmittance of the incident light that penetrates differ depending on the incident angle. Moreover, the circular light incident from the scattering central axis is projected into an elliptical shape with respect to a plane parallel to the optical film. Brings a strong diffusion of light in the direction of the long axis of the ellipse 323902 201241487, and a weak diffusion of light in the direction of the short axis orthogonal to the long axis. Further, the characteristics of the two structures of the plate-like structure of the foregoing type A and the columnar structure of the aforementioned type B are combined, and it is necessary to use different anisotropic diffusing films of the previous two or more layers. The characteristics obtained. Specifically, since light diffusion is preferentially performed in a necessary direction, the utilization efficiency of light can be substantially improved. According to the invention (2), the change in the diffusivity when changing the incident angle of light is gentle as compared with the currently known type A, and therefore, the visibility does not change drastically when applied to a panel, and can be given The observer has a more natural impression. According to the invention (3), the circular light incident from the scattering central axis is elliptical with respect to a plane parallel to the optical film, and a plane formed on the X-axis and the scattering central axis, and a plane formed by the Y-axis and the scattering central axis Since a fine structure is formed thereon, scattering in the X-axis direction and scattering in the Y-axis direction can be performed simultaneously, and the degree of diffusion in the X-axis direction and the degree of diffusion in the Y-axis direction can be different. According to the invention (4), since the density of the fine structure differs depending on the X-axis direction and the Y-axis direction, the diffusion of light differs depending on the direction of the irradiation light. [Embodiment] The scope of the present patent application and the definition of each term in the specification are described herein. The term "fine structure having a different refractive index" means a structure formed by a difference in refractive index of a part of a material constituting the optical film. Example 323902 12 201241487 As shown in Fig. 8, the optical film of Example 3 is described. As shown in Fig. 8, the 'fine structure is a structure optically observed in the cross section. It is presumed that these structures are formed when the material forming the optical film is solidified, for example, by adjusting the difference in density. The "scattering center axis" means that when the incident angle is changed, the scattering characteristic is a direction in which the incident angle is equal to the incident angle of light having a substantially symmetrical property at the boundary. Among them, the reason why the symmetry is substantially symmetrical is because the optical properties and the like described below have no strict symmetry when the scattering center axis is inclined with respect to the normal direction of the film surface. The scattering center axis is found by observing the projection shape of the circular light passing through the optical film while changing the incident angle as will be described later. The following description pertains to the scattering center axis. The 21st to 26th drawings have been used to illustrate the exact position of the spatial position of the scattering center axis, but if the direction of the azimuth of the tilt from the obtained scattering center is known, and the plane formed by the normal line is determined. The optical curve gives the correct tilt angle of the scattering center axis. In this optical curve, the scattering center axis can be represented by the angle of incidence corresponding to the maximum value sandwiched between the two minimum values. Fig. 1 and Fig. 2 are diagrams conceptually showing various optical curves and scattering central axes. First, the second diagram is an optical curve (W type) in which the overall shape of the optical film produced by irradiating UV light in the normal direction of the film is substantially symmetrical. The thick vertical line that coincides with the twist is the incident angle that coincides with the scattering center axis at this time. Fig. 2 is an optical film produced by irradiating uv light from a normal direction different from the film, and is an optical curve type in which the overall shape is not bilaterally symmetrical. Here, the thick vertical line passing through the maximum value Fc sandwiched between the two minimum values is also the incident angle coincident with the scattering center axis at this time. Thus, in either case 323902 13 201241487, the scattering center axis is determined by first focusing on the substantially symmetrical large valley region and then determining the center of the valley region. Here, in the case of Fig. 1 and Fig. 2, the valley region contains a minimum value on the left and right, and a maximum value is included between these minimum values. Thus, the position of this maximum value is the scattering center axis. In addition, 'the optical curve is not a W-type with a maximum value sandwiched between two minimum values, but a U-shaped shape in which a large value is hardly visible in a large valley area. The vicinity of the center of the flat portion of the valley bottom which is slightly equidistant is defined as the scattering center axis. Further, in the case where the optical curve appears as a V-shape, the deepest point in the center of the valley can be defined as the scattering central axis. The linear transmittance is a linear transmittance of light incident on the optical film, and is a ratio of the amount of transmitted light in the linear direction to the amount of incident light when incident from a certain incident angle. Straight line penetration rate (%) = (straight line penetration amount/incident light amount) χ1〇〇 The present invention has a fine structure having a different refractive index inside, and the linear transmittance of the incident light that penetrates varies depending on the incident angle. Optical flaws. Namely, the optical film of the present invention having an anisotropic diffusing property provides properties between the plate-like structure of the type A described above and the properties of the columnar crucible of the above-mentioned _B. Hereinafter, the contents of the present invention will be described in the first and second aspects. Heart (first form) In the first embodiment, the case where the scattering central axis is aligned with the normal direction of the optical film will be described as an example. Fig. 3 is a conceptual diagram for explaining the optical characteristics of the optical film of the present invention. In Fig. 3, 1 is an optical film of the present invention 323902 201241487, and 2 is a plane parallel to the optical film. As shown in Fig. 3, the optical film of the present invention has circular light incident from the scattering central axis position P, and is projected into an elliptical shape on a plane 2 parallel to the optical film. Here, the circular light means that the shape of the vertical cross section is a circular shape. The circular light is not particularly limited, and examples thereof include a laser such as a laser pointer. The flared light projected on the parallel plane 2 has a long axis A-A' and a short axis B-B'. The elliptical shape is that the circular light is diffused and penetrated in the X-axis direction to expand in the long axis A-A' direction, and the circular light is diffused in the Y-axis direction so as to be in the short axis B-B' direction. The shape that is expanded and projected to form. That is, the projection into an elliptical shape means that the degree of diffusion into the X-axis direction and the Y-axis direction of the optical film is different. Thus, not only the difference in diffusibility due to the direction is obtained, but also in the present invention, a certain light diffusion can be observed in the direction of the short axis B-B'. Fig. 4 is a view showing scattering characteristics in the case where the scattering central axis is in the normal direction like the optical film of the present embodiment. That is, Fig. 4 is a view showing the shape of light projected on the plane 2 when the incident angle is changed by the light penetrating the P point in Fig. 3. Since the objective of the optical film of the present invention is an optical property interposed between the above-mentioned plate-like structure and the rod-like structure, it has a scattering central axis which has been explained in the case of a rod-like structure. As shown in Fig. 4, the central diffusing shape is elliptical. The angle of incidence of the diffuse shape thus formed in the center is identical to the center axis of the scattering. However, it is more rounded than the ellipse shown in Fig. 25, and the diffused shape of the obliquely incident light also exhibits a shape intermediate between the crescent shape of Fig. 22 and the elliptical shape of Fig. 25. As explained above, even if the illumination direction of the uv light on the 323902 15 201241487 is not known, the scattering center axis of the optical film can be found using only a simple device like a laser index. In addition, in the case of the central axis, the method shown in Fig. 24 is applied, because =2. The axis is on the extension line of the bifurcated line, so the scattering center axis can be obtained from the separated, two crescent shapes. s position. In the present invention, the light incident from the scattering central axis exhibits a particularly remarkable characteristic of its scattering characteristics. The relationship between the relationship Τχ indicating the scattering characteristic in the X-axis direction and the peak width of the relationship Ty representing the scattering characteristic in the γ-axis direction satisfies a predetermined relationship. That is, the peak width FmaxmoX of the value of one tenth of the maximum value of the peak of the diffuse transmittance in the aforementioned relationship 十分 and one tenth of the maximum value of the peak of the diffuse transmittance in the aforementioned relationship Ty The peak width Ffflaxlmy of the value satisfies the relationship of the following formula (1). 1 · 5 < Fmaxl/l〇X / Fmaxl/l〇y< 4· 5 ( 1 ) The peak width Fmi/u reflects the scattering characteristics of the optical film. By adjusting the ratio of the peak width within such a range, the difference in scattering characteristics in the x-axis direction and the γ-axis direction is moderately adjusted. Here, the relationship Τχ refers to the relationship between the exit angle in the plane formed by the χ axis on the plane of the optical film and the scattering center axis, and the diffuse transmittance of the exit angle. On the other hand, the relationship Ty refers to the relationship between the exit angle in the plane formed by the γ-axis on the plane of the optical film and the aforementioned scattering central axis and the diffuse transmittance of the exit angle. Further, in the present invention, it is more suitable to particularly satisfy the following characteristics. 2· 0 < Fmaxl/IQX / Fmaxm〇y< 3· 〇323902 8 16 201241487 The scattering characteristic of the optical film of the present invention is evaluated by the method shown in Fig. 6 using a goniometric photometer. . Light was irradiated onto the optical film of the present invention, and the transmittance of light emitted from the film was measured. % The light receiver is rotated around the light source in the X direction (up and down direction in the paper surface) and the Y direction (in the direction of the paper surface). Fig. 7 shows the scattering characteristics of the optical film of the following Example 2. In Fig. 7, the horizontal axis represents the angle with respect to the detector of the optical film, and the vertical axis represents the transmittance defined below. Diffuse transmittance = (detected light amount of the detector / under the condition of no optical film 'detected light amount when the detector is disposed on the front side of the light source) χ 100 In Fig. 7, 'the dotted line indicates the X-axis and the scattering center The relationship between the exit angle in the plane formed by the axis and the diffuse transmittance of the exit angle X (X-axis direction), the solid line indicates the exit angle in the plane formed by the γ-axis and the scattering center axis, and the exit angle The relationship of the diffuse transmittance rate Ty (Y-axis direction) ° Fmaxl / 1 () X is the value of one-tenth of the maximum value of the peak of the diffuse transmittance of the relationship τ ( (X-axis maX) (X-axis) Maxl/10) corresponds to the peak width. On the other hand, Fmaxl / 1 ° y is the peak width corresponding to the value of the maximum value (Y # maX) of the peak of the diffuse transmittance of Ty (X axis maxl / lG). Further, in the optical film of the present invention, the relationship between the incident angle of the light in the in-plane of the X-axis and the scattering: the axis and the linear transmittance (%) is the maximum value of the linear transmittance Fa(8) and The angle A() of the maximum value and the minimum value Fb(%) of the linear transmittance and the angle B〇 at which the minimum value is obtained satisfy the relationship of the following formula (2): °*70<(Fa-Fb)/ I aB I <2.0 (2). 323902 17 201241487 By satisfying the above-mentioned miscellaneous, the angular dependence of the straight line material is relieved. If it is used in a display, the problem of sharp changes in the quality caused by the angle change can be solved. In the present invention, it is particularly suitable for those satisfying the following characteristics. 0. 90< (Fa~Fb)/ | Α-β I <1.7 where angles A and B mean the angle with respect to the normal of the optical film, and the relationship 'back to the first! The relationship between the incident angle of light and the linear transmittance (optical curve) in the optical film of the present invention will be described in detail. The optical curve of the optical film of the present invention is a curve which is slightly symmetrical about the center axis of the scattering. The curve has three maxima and two minima. That is, if the incident angle is changed to measure the straight-through light, there is a minimum value FB1*Fm in each of the two places (in addition, the incident angle corresponding to the minimum value Fbi is Βι 'the minimum angle & corresponding incident angle Recorded as b2). There is a relatively small maximum value Fc at the position where the minimum value is sandwiched. The incident angle of this maximum is consistent with the central axis of the political shot. On both sides of the maximum value p*c, there is a maximum value fa1*maximal value FA2 sandwiched by the minimum value FB1*Fm (in addition, the incident angle corresponding to the maximum value Fm is denoted as Ai, and the incident corresponding to the maximum value FA2 The angle is recorded as A2). For the relationship in the formula (2), among the two maximum values (FA1*FA2) and the minimum values (Fbi and Fb2), the group having the larger value among the following (a) and (b) is recorded as Fa and A, Fb and B.
(a) (Fai-Fb〇/ I Αι-Bi I (b) (Fa2*"Fb2)/ I A2-B2 1 即，使用在光學曲線中從極大值到極小值的斜率較大 323902 18 201241487 的一側。在此條件下，本發明的光學膜滿足前述式（2)的關 係。另外，光學曲線的測定方法如上述背景技術以及第16 圖中記載般。 第8圖是本發明的光學膜的截面照片。第8圖（A)是 平行於X軸-散射中心軸平面的方向的截面照片，第8圖（B) 是平行於Y軸-散射中心軸平面的方向的截面照片。如第8 圖所示，在X軸方向截面上以/zm為單位的折射率高低不 同的微細結構呈現縱長的條紋形狀。另一方面，在與其正 交的Y軸方向截面上呈現被認為是微細結構者，但有時候 無法確認到該結構。從該照片可以明顯地看出，如果比較 本發明的光學膜的平行於X軸-散射中心軸平面的截面上 的微細結構的密度、與平行於Y軸-散射中心軸平面的截面 上的前述微細結構的密度，則前者比後者高。即，本發明 的光學膜認為因在某一方向上微細結構密集地存在所以光 強烈散射，另一方面，在與其正交的方向上微細結構稀疏 地存在故光微弱漫射。 (第二形態） 本發明的第二形態，是散射中心軸具有與光學膜的法 線方向不一致的傾斜度的光學膜。第5圖表示在散射中心 軸向Y軸方向傾斜的情況下的散射特性，該第5圖是，第 3圖中穿透P點的光，在改變入射角的情況下投影在平面2 上的光的形狀的圖。其還顯示出在第22圖與第25圖的中 間的性質。在任意變化入射角使光入射時，漫射形狀均顯 不為從圓形到擴圓形的對稱性南的形狀*具有該中心的擴 323902 19 201241487 圓形的散射光所對應的入射角與散射中心轴一致。 在第二形態中，顯示出了與散射中心轴與光學膜的法 線方向一致的第一形態同樣的散射特性以及光學曲線。 第9圖是從偏離膜面的法線方向10°的方向上照射UV 光線而製造的光學膜的截面照片。在這種情況下，在X軸 方向（第9圖（A))上形成有條紋形狀的折射率高低不同的 微細結構，但在與其正交的Y軸方向（第9圖（B))上幾乎看 不到微細結構。 第10圖是從偏離膜面的法線方向45°的方向上照射 UV光線而製造的光學膜的截面照片。在這種情況下，在X 軸方向（第10圖（B))上形成有色彩濃之條紋形狀的折射率 高低不同的微細結構，在與其正交的Y軸方向（第10圖（A)) 上雖然.能夠看到微細結構，但是與X軸方向相比是淺的條 紋形狀。 [光學膜的製造方法] 本發明的光學膜，可以藉由在特殊的條件下向特定的 光固化樹脂層進行UV照射而製作。以下，首先說明光學膜 的原料，然後說明製造程序。 [光學膜的原料（光固化性化合物）] 作為形成本發明的光學膜的材料的光固化性化合物， 是由選自具有自由基聚合性或陽離子聚合性官能團的聚合 物、寡聚物、單體的光聚合性化合物和光起始劑構成的、 通過照射紫外線和/或可見光而聚合並固化得到的材料。 自由基聚合性化合物，主要是在分子中含有一個以上 323902 20 ⑧ 201241487 的不飽和雙鍵的化合物，具體地可以舉出：稱為丙烯酸環 氧酯、丙烯酸氨基甲酸酯、聚酯丙烯酸酯、聚醚丙烯酸酯、 聚丁二烯丙烯酸酯、聚矽氧丙烯酸酯等的丙烯酸酯寡聚物 以及’丙烯酸2-乙基己酯、丙烯酸異戊酯、丙烯酸丁氧基 乙酯、乙氧基二乙二醇丙烯酸酯、丙烯酸苯氧基乙酯、丙 烯酸四氫糠酯、丙烯酸異降冰片烯酯、丙烯酸2-羥基乙 酯、丙烯酸2-羥基丙酯、2-丙烯醯氧基苯二曱酸、二環戊 烯基丙烯酸酯、三乙二醇二丙烯酸酯、新戊二醇二丙烯酸 酯、1，6-己二醇二丙稀酸、雙紛A的E0加成物二丙稀酸酯、 三羥甲基丙烷三丙烯酸酯、E0改性三羥曱基丙烷三丙烯酸 醋、新戊四醇三丙烯酸酯、新戊四醇四丙烯酸酯、二（三經 甲基丙烷）四丙烯酸酯、二新戊四醇六丙烯酸酯等丙烯酸酯 單體。另外’這些化合物可以各單體的形式使用，也可以 多個混合使用。另外，雖然同樣也能夠使用曱基丙烯酸酯， 但是由於通常情況下相對於曱基丙烯酸酯而言，丙烯酸酯 的光聚合速度更快故較佳。 陽離子聚合性化合物可以使用在分子中具有1個以上 的環氧基、乙烯基醚基、氧雜環丁烷基的化合物。具有環 氧基的化合物可以舉出·· 2-乙基己基二甘醇縮水甘油醚、 聯苯的縮水甘油醚、雙酚A、氫化雙酚A、雙酚F、雙酚AD、 雙酚S、四甲基雙酚a、四甲基雙酚F、四氯雙酚a、四溴 雙紛A等雙酚類的縮水甘油醚類，酚酚醛清漆（phen〇1 nov’olac)、甲紛紛駿清漆（cres〇i nov〇iac)、漠紛紛搭清 漆、鄰甲酚酚醛清漆等酚醛清漆樹脂的多縮水甘油醚類， 323902 21 201241487 乙二醇、聚乙二醇、聚丙二醇、丁二醇、1，6-己二醇、新 戊二醇、三羥曱基丙烷、1,4-環己烷二曱醇、雙酚A的E0 加成物、雙酚F的P0加成物等烷撐二醇類的二縮水甘油醚 類，六氫鄰苯二甲酸的縮水甘油酯、二聚酸的二縮水甘油 酯等縮水甘油酯類。 另外還可舉出：3,4-環氧基環己基曱基-3’，4’ -環 氧基環己烷羧酸酯、2-(3,4-環氧基環己基-5, 5-螺-3,4-環氧基）環己烷-間-二噁烷、二（3, 4-環氧基環己基曱基） 己二酸酯、二（3, 4-環氧基-6-曱基環己基曱基）己二酸酯、 3,4-環氧基-6-曱基環己基-3’，4’ -環氧基-6’ -甲基環 己烷羧酸酯、亞曱基雙（3, 4-環氧基環己烷）、二聚環戊二 烯二環氧化合物、乙二醇的二（3, 4-環氧基環己基曱基） 醚、亞乙基雙（3, 4-環氧基環己烷羧酸酯）、内酯改性3,4-環氧基環己基曱基-3’，4’ -環氧基環己烷羧酸酯、四 (3, 4-環氧基環己基甲基）丁烷四羧酸酯、二（3, 4-環氧基環 己基曱基）-4, 5-環氧基四氫鄰苯二甲酸酯等脂環式環氧化 合物，但是並不限於這些。 作為具有乙烯基醚基的化合物，可舉出例如二乙二醇 二乙烯基醚、三乙二醇二乙烯基醚、丁二醇二乙烯基醚、 己二醇二乙烯基醚、環己烷二曱醇二乙烯基醚、羥基丁基 乙烯基醚、乙基乙烯基醚、十二烷基乙烯基醚、三羥曱基 丙烷三乙烯基醚、丙烯基醚基伸丙基碳酸酯等，但是並不 限於這些。另外，乙烯基醚化合物通常為陽離子聚合性， 但是藉由與丙烯酸酯組合也可以進行自由基聚合。 323902 22 ⑧ 201241487 作為具有氧雜環丁烷基的化合物，可以使用1，4-雙 . [(3--乙基-3-氧雜環丁烷基曱氧基）甲基]苯、3-乙基-3-•(經 基曱基）-氧雜環丁烷等。 % 另外，以上的陽離子聚合性化合物，可以以各單體的 形式使用，也可以多種混合使用。上述光聚合性化合物並 不限於上述限定的化合物。另外，為了產生足夠的折射率 差，在上述光聚合性化合物中，為了獲得低折射率可導入氣 原子（F)，為了獲得高折射率可以導入硫原子（s)、填原子 (Br)、各種金屬原子。另外，如日本特表2005-514487所揭 示般，在上述的光聚合性化合物中添加在氧化鈦（Ti〇2)、氧 化錯（Zr〇2)、氧化錫（SnOx)等高折射率金屬氧化物形成的 微粒的表面上導入丙烯醯基、甲基丙烯醯基、環氧基等光 聚合性官能團的功能性超微粒子，也是有效的。 [光學膜的原料（光起始劑）] 月t»夠使自由基t合性化合物聚合的光起始劑可舉出： 二苯甲酮、二苯基乙二酮（benzil)、米希勒明（H，s ketone)、2_氯噻噸酮、2, 4-二乙基噻噸酮、苯偶姻乙醚 (benzom ethyl ether)、苯偶姻異丙醚、苯偶姻異丁醚、 2’2-二乙氧基苯乙酮、二苯基乙二酮二甲基縮酮、—二 甲氧基-1,2-二苯基乙烧-卜酮、2—經基甲基 苯基]-2-嗎似㈣_卜卜[4_(2，基乙氧基）苯基]_2_ 經基-2-甲基-卜丙燒+酮、雙（環戊二烯基）_雙（2 6 + 各]-基）苯基）鈦、2_f基|二甲基氨基+ 嗎 323902 23 201241487 啉代苯基）-丁酮-1、2, 4, 6-四曱基苯曱醯基二苯基膦氧化 物等。另外，這些化合物可以以單體形式使用，亦可以多 個混合使用。 陽離子聚合性化合物的光起始劑是藉由光照射產生 酸、利用該生成的酸可使上述陽離子聚合性化合物聚合的 化合物’通常適合使用鑌鹽（onium salt)、茂金屬絡合物 (metall〇cene compiex)。鏽鹽可使用重氮鏽鹽、锍鹽、碘 鑌鹽、鱗鏽鹽、ί西鹽等，與這些相對的離子可使用bf4-、 PF6、AsFf、SbF「等陰離子。具體的例子可舉出：4_氯苯 重氮六氟磷酸鹽、三苯基銃基六氟銻酸鹽、三苯基锍基六 氟磷酸鹽、（4-苯硫基苯基）二苯基鈒基六氟銻酸鹽、（4_ 苯硫基苯基）二苯基鍍基六氟磷酸鹽、雙[4_(二苯基疏基） 苯基]琉鍵—雙-六氟録酸鹽、雙[4-(二苯基疏基）苯基]硫喊 越雙氟磷酸鹽、(4_甲氧基苯基)二苯基銃基六氟銻酸 孤（扣甲氧基苯基）苯基碘鑌六氟銻酸鹽、雙（4_第三丁其 :基)碘鑷六氟填酸鹽、节基三苯基磷鏽六氟銻酸趟 磷酸鹽、“ 5_異丙基苯）（…環戊二締 =^鹽等，但是並不限定於這些。另外 [可二以膜各單體的形式使用，也可以多種現合使用 先予犋的原料（摻配量、其他任意成分）] 在本發明中，相對於光聚合性化合 述光起始劑以0.0】至Π)重量份、較佳為 份、更佳為以0.…重量份的程度摻配”至:重量 到0. 01舌曰八& 廷是因為在不 323902 重酬情況下光固化性降低’在超過10重量份 24 201241487 進行摻配的情況下，會帶來只有表面固化而内部固化性降 低的弊害、著色、阻礙柱狀結構的形成。這些光起始劑通 常可以把粉體直接溶解在光聚合性化合物中而使用，在溶 解性不好時，也可以使用預先以高濃度把光起始劑溶解在 極少量的溶劑中而得者。如此的溶劑更佳為光聚合性的， 具體可舉出碳酸伸丙酯、丁内酯等。另外，為了提高光 聚合性’也可以添加公知的各種染料、增感劑。而且，也 可以與光起始劑一起使用通過加熱能夠使其固化的熱固化 起始劑。在這種情況下，可以期待在光固化之後，通過加 熱進一步促進光聚合性化合物的聚合固化，而形成固化完 全的固化物。 在本發明中’藉由使單獨的上述光固化性化合物或使 多個混合之組合物固化，而可形成異向性漫射層。另外， 藉由使付光固化性化合物和不具有光固化性的高分子樹脂 的〉昆合物固化，也可形成本發明的異向性漫射層。在此可 使用的高分子樹脂可舉出丙烯酸類樹脂、苯乙烯樹脂、苯 乙烯-丙烯酸共聚物、聚氨基曱酸酯樹脂、聚酯樹脂、環氧 樹脂、纖維素系樹脂、醋酸乙烯酯系樹脂、氯乙烯_醋酸乙 歸略共聚物、聚乙烯醇縮丁醛樹脂等。這些高分子樹脂和 光固化性化合物必須在固化前具有充分的相容性，但為了 確保該相容性還可使用各種有機溶劑、塑化劑等。另外， 在使用丙烯酸酯作為光聚合性化合物的情況下，從相容性 的角度來看較佳為丙烯酸類樹脂作為高分子樹脂。 [程序] 3239〇2 201241487 接下來說财關財發_光學_製造綠（程序）。 在透明PET膜般合適的基材上塗覆上述光固化性組合物， 設置塗覆膜(光固化樹脂層）。根據需要藉由乾燥使溶劑揮 發，其乾燥膜的厚度為1Q至較佳為20至⑽㈣ 更佳為25至5G/zm。在乾燥膜的厚度不到的情況 下、、里過下述的UV照射程序得到的光漫射性不足，故較為 不佳。另-方面，在乾燥膜厚超過2叫m㈣況下，整體 的漫射性過強故難以得到本發明特徵之異向性，並且成本 上升，不適合薄型化用途，因此也不佳。進一步地，藉由 在該塗覆膜上層合離型膜、下述的掩膜，而製作感光性層 合體。 (將含有光固化性化合物的組合物以片狀形式設置在基體 上的方法） 此處，將含有光固化性化合物的組合物以片狀形式設 置在基體上的方法，採用通常的塗覆方式、印刷方式。具 體來說可使用：氣刀塗布、刮條塗布、刮板塗布、刮刀塗 布、逆轉塗布（reverse coating)、傳遞輥塗布、凹版輥塗 布、輕觸輥式塗布、澆鑄塗布、喷式塗布、喷嘴式塗布（sl〇t orifice coating)、壓延塗布、壩式塗布、浸潰塗布、模 頭塗布等塗布、凹版印刷等凹版印刷、網版印刷等孔版印 刷等的印刷等《在組合物黏度低的情況下，可在基體的周 圍設置一定高度的堰，並在該堰包圍之中澆鑄組合物。 (掩膜的層合） 為了有效地形成本發明光學膜的特徵之微細結構，掩 323902 ⑧ 26 201241487 膜可密接名j 在 光的照射 ·固化性組合物層的光照射的一側，並層合使 體中分散強度會局部變化。掩膜的材質較佳為在聚合物基 被碳i收有碳等光吸收性填料而成者，因入射光的一部分 外，即使而開口部是光能夠充分穿透的結構的材質。另 防止氧$僅在光固化性組合物層上層合通常的透明膜， (光源）軋危害和促進柱狀體形成方面也是有效的。 用於對3有光固化性化合物的組合物進行光照射的 光源通常使用短弧（short arc)的紫外線產生光源，具體來 說可使用高壓水銀燈、低壓水銀燈、金屬齒化物燈、氙氣 燈等。向含有光固化性化合物的組合物照射的光線必須含 有能夠固化該光固化性化合物的波長，通常利用水銀燈的 么中心的波長的光。 以365⑽為 _ 為了從來自上述的短弧的UV光線的光製作出平行光 12，例如町在光源的背後配置反射鏡，並使得在規定的 =尚上射出祚為點光源之光，再藉由菲涅耳透鏡（Fresnel 使该光成為平行光。菲涅耳透鏡是把通常的透鏡分割 16同心圆狀隱诚並減少厚度的透鏡，具有鑛齒狀的截面。 成采從，點狀光源出射的光線通過菲涅耳透鏡，那麼方向凌 光的#就會統—在—個方向上，㈣成平行光線。 术過，為了得到ί製作本發明的光學膜時必要的平行ϋν 出射光，炎;^定必3使用菲遣耳透鏡’可包括雷射之各 二法線脖射的υν光線 3239〇2 27 201241487 為了製作本發明的光學膜，在上述感光性層合體上從離 型膜或者掩膜侧在法線方向上照射uv光線，重要的是不僅 僅是照射上述的平行光線，還同時照射與其在一個方向上 漫射的漫射光線。為了照射這樣的光線，例如可使用光栅 透鏡（lenticular lens)°UV 平行光線通過光柵（lenticular) 從而可形成上述光線（與平行光線在一個方向上漫射的漫 射光線）。這種情況下的光栅可以是僅在一個方向上漫射的 漫射光源的光線（可在一定程度上混合平行光線）。另外， 也可以在光柵透鏡上組合曝光掩膜。光柵透鏡是指具有多 個半圓筒狀或圓弧狀的細長的凸部並列配置形成的凸部 面，該凸部面的相反側是平坦的面的透鏡（以下，把前述 “半圓筒狀或者圓弧狀的細長的凸部”簡稱為魚板形狀）。 在此，對於使用光栅透鏡的例子的情況，前述“同時 照射平行光線和在一個方向上漫射的漫射光線”的意思可 理解為，需要以魚板形狀並列而成的光栅透鏡的凸部之扇 狀擴展的光線（平面扇形漫射），是在縱方向上平行地排列 的狀態（漫射平面是平行的）。 第11圖表示本發明的光學膜的製造方法的一種形態。 在橫長的類半圓枉的凸部14a縱向排列而成的光栅透鏡14 上’平行地放置感光性層合體1〇(由靠近透鏡的一側開始 依次為離型PET或者掩膜18、光固化樹脂層20以及透明 PET22) ’並向著光栅透鏡14在光柵透鏡14的法線方向上 照射UV平行光線12 ’而得光固化者。如果UV光通過光栅 透鏡14 ’則以光撕的凸部14a將光16在Y方向上漫射， 323902 28 ⑧ 201241487 被照射在感光性層合體10上。如果隔著光柵透鏡，則形成 了在一個方向（第11圖中為Y方向，朝向紙面的裏面的方 向）上具有寬的擴展，在與其正交的方向（第11圖中為X 方向，紙面的縱方向）上只有窄的擴展的異向性的光16。 感光性層合體10如果受到照射則會光固化，形成在光固化 樹脂層内具有内部結構的固化樹脂層。 (2)不是法線方向的UV光線的照射 作為其他形態，也可以從與法線方向不同的方向上傾 斜地將平行光線照射在感光性層合體上。該形態的一個例 子示於第12圖。從與光柵透鏡的凸面（魚板形狀面）14a相 反的方向，照射相對於光柵透鏡14的法線方向傾斜了 30° 平行光線12(相對於光柵透鏡具有60°的角度）。此時，從 光柵透鏡的凸面14a來的漫射光16是斜方向照射的。結果 漫射光16如圖所示，以從感光性層合體的法線方向開始向 X軸傾斜了 3 0 °的方向為中心，擴展成平面扇形而照射在感 光性層合體10的斜方向，並在光固化層20中進行光固化。 另外，使用光栅透鏡的上述的UV照射方法，是用以 製作本發明的光學膜的方法之一，本發明並不限定於此。 總之，為了在光固化性組合物層中形成特定的内部結構， 重要的是在感光性層合體上照射擴展成平面扇形狀的UV 光。 即，藉由對光固化樹脂層照射平面扇形之擴展的光的 步驟，而形成本發明的折射率高低不同的微細結構。另外， 照射的光具有能夠使該感光性組合物固化的波長。另外， 323902 29 201241487 在上述的照射步驟中，適合使用已經將平行光線漫射成平 面扇形的光。 在製作本發明的光學膜的時候，通過上述的光柵透鏡 等而照射在感光性層合體上的UV光的照度，較佳為0.(Π 至100mW/cm2的範圍，更佳為在〇· 1至20mW/cm2的範圍。 原因在於照度如果在0. OlmW/cm2以下則由於固化需要長時 間’所以生產效率變低，如果在100mW/cm2以上，由於光 固化性化合物的固化過快而不形成結構，變得不能表現出 目標的異向性漫射特性。 UV的照射時間並沒有特別的限定，為1〇至18〇秒， 更佳為30至120秒的時間。其後，通過剝離脫模膜，可以 得到本發明的異向漫射光學膜。 本發明的光學骐，是藉由如上前述比較長時間地照射 低照度UV光’而在光固化性組合物層的内部形成特定的内 部結構而得到的膜。因此，在只有這樣的uv照射的情況 下’未反應㈣合物成分會殘留，有時會產生發黏並在處 理性、収性方面會產㈣題。在此情況下，通過追加照 射1000mW/Cra2以上的高強度的uv光而可使得殘存的聚合 物固化。此時的UV照射較佳維從掩膜侧的相反側進行。 (實施例） 按照以下的方法，製造本發明的光學膜以及比較例的 光學膜。 [實施例1垂直照射] 在1〇〇_的透明PET膜上，塗覆日本特表2嶋_ 323902 ⑧ 201241487 514487的實施例3所示的配方的光固化性組合物，設置乾 燥膜厚50//m的塗覆膜，更進一步在該塗覆膜上，以離型 面接觸塗覆膜之方式層合38 的離型用PET膜。從該層 合體的離型用PET膜侧開始在相對於法線為〇°的方向上， 隔著半徑（r)=0.5mm、間距（P)=〇.5mm的光栅透鏡（以平行 於層合體的形式設置），照射5mW/cm2的平行UV光線（使用 光柵透鏡而形成）90秒的時間。藉由把離型用PET膜從固 化後的層合體上剝離，而得到本發明的光學膜（透明PET/ 光固化樹脂層）（參照第11圖）。透過光柵透鏡照射的UV 光線’在X方向（紙面的縱向）上幾乎不散射而是平行的， 在Y方向（向著紙面的裏面的方向）上呈現散射之光線。 [實施例2垂直照射] 除了將使用的光柵透鏡設定為半徑（r)=〇· 5mm、間距 (p):=0.7mm以外，進行與實施例1同樣的操作，而得到本 發明的光學膜（透明PET/光固化樹脂層）。 [實施例3垂直照射] 使用藉由在PET膜上塗覆乾燥分散有平均粒徑 的石墨粒子的聚乙_樹脂水溶液*得到之光學濃度⑽) 為0.5的曝光掩膜’而代替離㈣ρΕΤ膜，將光柵透鏡設 定為半徑（r>U5mm、間距（ρ)=〇 ι麵，除此之外，進行 與’.施例1同樣的操作，而得到本發明的光學膜(透明ρΕτ/ 光固化樹脂層）。 [實施例4斜照射] 使得照射的方向從層合體的法線方向向 X軸侧傾斜 323902 31 201241487 30。，除此之外，進行與實施例2同樣的操作’而得到本發 明的光學膜（透明PET/光固化樹脂層）（參見第12圖）。另 外，光柵透鏡和層合體設置為平行’通過光柵透鏡照射的 UV光線是在X軸方向上傾斜30°且平行’在Y軸方向上散 射的光線。 [比較例1] 除了不使用光柵透鏡以外，與實施例1進行同樣的操 作，而得到作為比較的光學膜（透明PET/光固化樹脂層）。 由於沒有通過光栅透鏡，所以照射完全的平行光線，而得 到具有類型B的柱狀的微細結構的光學膜。 [比較例2] 使用市售的Lumisty (註冊商標、住友化學）作為類型 A的具有板狀的微細結構的光學膜。 [評價1光學曲線的比較（直線穿透率）] 入射角依存性係藉由使用如第16圖所示的測角光度 計（GENESIA 公司製 GENESIA Gonio/Far Field profiler；) 的方法而進行評價。在圖中未表示的光源和光接收器3之 間配置樣品，並以樣品表面的直線L為中心一邊改變角度 一邊測定直線穿透樣品進入光接收器3的直線穿透率，藉 此可以得直線穿透率（另外，詳細的測定方法I己載在日本特 開2005-265915號公報的0048段中）。第13圖示出關於實 施例1至3以及比較例丨和2的結果。另外，實施例2的 結果與實施例1相同，因此一併記錄。根據該結果，實施 例1、2及3的光學膜，在作為法線方向的附近具有極 323902 32 201241487 大值，在±5至10。的入射角B處得極小值Fb，從此處開始 進一步擴大入射角，在40至50°附近的入射角a處得極大 值Fa。從測定得到的光學曲線算出（Fa-Fb)7丨A-B丨，而表 示在表1中。 [評價2旋轉光接收器時的漫射穿透性] 漫射的異向性係使用測角光度計，用第6圖所示的方 法進行評價。使用前述實施例和比較例中製造的光學膜並 照射光’測定從膜射出的光的穿透率。測定時，第6圖中， 以從光學膜的光出射地點為中心，使光接收器在X方向（紙 面中的上下方向）、Y方向（紙面的近至遠的方向）旋轉。結 果示於第14圖。算出Fmaxl/lOX/Fraaxmoy並示於表1 〇 表1(a) (Fai-Fb〇/ I Αι-Bi I (b) (Fa2*"Fb2)/ I A2-B2 1 That is, the slope from the maximum value to the minimum value in the optical curve is large 323902 18 201241487 Under these conditions, the optical film of the present invention satisfies the relationship of the above formula (2). The method of measuring the optical curve is as described in the above background art and Fig. 16. Fig. 8 is an optical diagram of the present invention. A cross-sectional photograph of the film. Fig. 8(A) is a cross-sectional photograph parallel to the direction of the X-axis-scattering central axis plane, and Fig. 8(B) is a cross-sectional photograph parallel to the Y-axis-scattering central axis plane. As shown in Fig. 8, the fine structure having different refractive index in /zm in the cross section in the X-axis direction exhibits a vertically long stripe shape. On the other hand, the cross-section in the Y-axis direction orthogonal thereto is considered to be Fine structure, but sometimes the structure cannot be confirmed. It is apparent from the photograph that if the density of the fine structure on the cross section parallel to the X-axis-scattering central axis plane of the optical film of the present invention is compared, and parallel The aforementioned micro-junction on the section of the Y-axis-scattering central axis plane The density of the former is higher than that of the latter. That is, the optical film of the present invention is considered to have strong scattering of light due to the dense structure in a certain direction, and on the other hand, the fine structure exists sparsely in the direction orthogonal thereto. (Second aspect) The second aspect of the present invention is an optical film in which the scattering central axis has an inclination that does not coincide with the normal direction of the optical film. Fig. 5 shows that the scattering center is inclined in the Y-axis direction in the axial direction. The scattering characteristic in the case, the fifth figure is a diagram of the shape of the light projected on the plane 2 in the case of changing the incident angle by the light penetrating the P point in Fig. 3. It is also shown in Fig. 22. The nature of the middle with Fig. 25. When the incident angle is arbitrarily changed, the diffused shape is not symmetrical from the circular shape to the circular shape. The shape with the center is expanded by 323902 19 201241487 The incident angle corresponding to the scattered light coincides with the scattering center axis. In the second aspect, the same scattering characteristics and optical curves as in the first form in which the scattering central axis coincides with the normal direction of the optical film are shown. It is a cross-sectional photograph of an optical film produced by irradiating UV light from a direction which is 10° from the normal direction of the film surface. In this case, a stripe shape is formed in the X-axis direction (Fig. 9(A)). A fine structure having a different refractive index, but a fine structure is hardly observed in the Y-axis direction (Fig. 9(B)) orthogonal thereto. Fig. 10 is a direction from the normal direction of the film surface by 45°. A cross-sectional photograph of an optical film produced by irradiating UV light. In this case, a fine structure having a different refractive index of a color-rich stripe shape is formed in the X-axis direction (Fig. 10(B)). In the Y-axis direction of the intersection (Fig. 10(A)), although the fine structure can be seen, it is shallower than the X-axis direction. [Method for Producing Optical Film] The optical film of the present invention can be produced by subjecting a specific photocurable resin layer to UV irradiation under special conditions. Hereinafter, the raw material of the optical film will be described first, and then the manufacturing procedure will be described. [Material of Optical Film (Photocurable Compound)] The photocurable compound which is a material for forming the optical film of the present invention is a polymer, an oligomer, a single selected from a group having a radical polymerizable or cationically polymerizable functional group. A material composed of a bulk photopolymerizable compound and a photoinitiator which is polymerized and cured by irradiation with ultraviolet rays and/or visible light. The radical polymerizable compound is mainly a compound containing one or more unsaturated double bonds of 323902 20 8 201241487 in the molecule, and specifically, it is called epoxy acrylate, urethane acrylate, polyester acrylate, Acrylate oligomers such as polyether acrylate, polybutadiene acrylate, polyoxy acrylate, and the like, 2-ethylhexyl acrylate, isoamyl acrylate, butoxyethyl acrylate, ethoxylate Ethylene glycol acrylate, phenoxyethyl acrylate, tetrahydrofurfuryl acrylate, isobornyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-propenyl phthaloxy phthalate , dicyclopentenyl acrylate, triethylene glycol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylic acid, double A's E0 adduct diacrylate , trimethylolpropane triacrylate, E0 modified trihydrocarbyl propane triacrylate, neopentyl alcohol triacrylate, neopentyl alcohol tetraacrylate, di(trimethylpropane) tetraacrylate, Propylene such as dipentaerythritol hexaacrylate Acid ester monomer. Further, these compounds may be used in the form of individual monomers or may be used in combination. Further, although mercapto acrylate can be used in the same manner, since the photopolymerization speed of the acrylate is usually faster than that of the mercapto acrylate, it is preferable. As the cationically polymerizable compound, a compound having one or more epoxy groups, a vinyl ether group or an oxetanyl group in the molecule can be used. Examples of the compound having an epoxy group include 2-ethylhexyl diglycol glycidyl ether, glycidyl ether of biphenyl, bisphenol A, hydrogenated bisphenol A, bisphenol F, bisphenol AD, and bisphenol S. , diglycidyl ethers of bisphenols such as tetramethyl bisphenol a, tetramethyl bisphenol F, tetrachlorobisphenol a, tetrabromo bisphenol A, phenol novolac (phen〇1 nov'olac), A Polyglycidyl ether of phenolic varnish resin such as cres〇i nov〇iac, indifference varnish, o-cresol novolac, 323902 21 201241487 ethylene glycol, polyethylene glycol, polypropylene glycol, butanediol , 1,6-hexanediol, neopentyl glycol, trihydroxydecylpropane, 1,4-cyclohexanedimethanol, E0 adduct of bisphenol A, P0 adduct of bisphenol F, etc. A glycidyl ether such as a diglycidyl ether, a glycidyl ester of hexahydrophthalic acid or a diglycidyl ester of a dimer acid. Further, 3,4-epoxycyclohexyldecyl-3',4'-epoxycyclohexanecarboxylate, 2-(3,4-epoxycyclohexyl-5, 5 - spiro-3,4-epoxy)cyclohexane-m-dioxane, bis(3,4-epoxycyclohexyldecyl) adipate, bis(3,4-epoxy- 6-decylcyclohexyldecyl) adipate, 3,4-epoxy-6-fluorenylcyclohexyl-3',4'-epoxy-6'-methylcyclohexanecarboxylate , fluorenylene bis(3,4-epoxycyclohexane), dicyclopentadiene diepoxide, bis(3,4-epoxycyclohexyldecyl) ether of ethylene glycol, sub Ethyl bis(3,4-epoxycyclohexanecarboxylate), lactone modified 3,4-epoxycyclohexyldecyl-3',4'-epoxycyclohexanecarboxylate , tetrakis(3,4-epoxycyclohexylmethyl)butane tetracarboxylate, bis(3,4-epoxycyclohexyldecyl)-4,5-epoxytetrahydrophthalic acid An alicyclic epoxy compound such as an acid ester, but is not limited thereto. Examples of the compound having a vinyl ether group include diethylene glycol divinyl ether, triethylene glycol divinyl ether, butanediol divinyl ether, hexanediol divinyl ether, and cyclohexane. Diterpene divinyl ether, hydroxybutyl vinyl ether, ethyl vinyl ether, dodecyl vinyl ether, trishydroxypropyl propane trivinyl ether, propenyl ether propyl carbonate, etc., but Not limited to these. Further, the vinyl ether compound is usually cationically polymerizable, but radical polymerization can also be carried out by combination with an acrylate. 323902 22 8 201241487 As a compound having an oxetane group, 1,4-bis. [(3--ethyl-3-oxetanyloxy)methyl]benzene, 3- Ethyl-3-•(transbenzyl)-oxetane and the like. Further, the above cationically polymerizable compound may be used in the form of each monomer, or may be used in combination of plural kinds. The photopolymerizable compound is not limited to the compound defined above. In addition, in order to obtain a sufficient refractive index difference, in the above photopolymerizable compound, a gas atom (F) can be introduced in order to obtain a low refractive index, and a sulfur atom (s), a filling atom (Br), or a sulfur atom can be introduced in order to obtain a high refractive index. Various metal atoms. Further, as disclosed in JP-A-2005-514487, a high refractive index metal oxide such as titanium oxide (Ti〇2), oxidized (Zr〇2), or tin oxide (SnOx) is added to the above photopolymerizable compound. It is also effective to introduce functional ultrafine particles of a photopolymerizable functional group such as an acryloyl group, a methacryloyl group or an epoxy group on the surface of the fine particles formed by the substance. [Materials of Optical Film (Photoinitiator)] The photoinitiator which is sufficient for the polymerization of the radical t-chelating compound at month t» can be exemplified by: benzophenone, diphenylethanedione (benzil), mich Leming (H, s ketone), 2_ chlorothioxanthone, 2, 4-diethylthioxanthone, benzom ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether , 2'2-diethoxyacetophenone, diphenylethylenedione dimethyl ketal, -dimethoxy-1,2-diphenylethen-bupropion, 2-methylmethyl Phenyl]-2-like (4)_Bu [4_(2,ylethoxy)phenyl]_2_yl-2-methyl-propylpropanone + ketone, bis(cyclopentadienyl)_double (2 6 + each )-yl)phenyl)titanium, 2_f group|dimethylamino+ 323902 23 201241487 phenyl phenyl)-butanone-1, 2, 4, 6-tetradecyl phenyl fluorenyl Diphenylphosphine oxide and the like. Further, these compounds may be used in the form of a monomer or may be used in combination. The photoinitiator of the cationically polymerizable compound is a compound which generates an acid by light irradiation, and which can polymerize the above cationically polymerizable compound by using the produced acid, and is generally suitable for using an onium salt or a metallocene complex (metall). 〇cene compiex). As the rust salt, a diazonium salt, a cerium salt, an iodonium salt, a scaly salt, a lysine salt, or the like can be used, and as the opposite ions, an anion such as bf4-, PF6, AsFf, or SbF can be used. Specific examples include exemplified : 4_chlorobenzenediazonium hexafluorophosphate, triphenylsulfonyl hexafluoroantimonate, triphenylsulfonyl hexafluorophosphate, (4-phenylthiophenyl)diphenylphosphonium hexafluoroantimony Acid salt, (4-phenylthiophenyl) diphenyl plated hexafluorophosphate, bis[4-(diphenylsulfanyl)phenyl]hydrazine bond-bis-hexafluoroantate, double [4-( Diphenyl sulfhydryl) phenyl] sulfonate bisfluorophosphate, (4-methoxyphenyl) diphenyl sulfonium hexafluoroantimonate (carboxylated phenyl) phenyl iodonium hexafluoro Citrate, bis(4_Tetidine:yl)iodonium hexafluoro-saltate, succinic triphenylphosphorus hexafluoroantimonate bismuth phosphate, "5-isopropylbenzene" (...cyclopentane In addition, it is not limited to these, and it may be used in the form of each monomer of the film, or a plurality of raw materials (mixing amount, other optional components) may be used in combination. In the invention, the photoinitiator is combined with photopolymerization to 0.0 To the weight part, preferably part, more preferably to the extent of 0.... parts by weight "to: weight to 0. 01 tongue 曰 eight & ting is because of the photocurability in the case of 323902 When the blending is carried out in more than 10 parts by weight of 24 201241487, it will cause the surface solidification and the internal curability to be reduced, the coloring, and the formation of the columnar structure. These photoinitiators can usually directly form the powder. It is used by being dissolved in a photopolymerizable compound, and when the solubility is not good, it is also possible to use a solution in which a photoinitiator is dissolved in a very small amount in a high concentration in advance. Such a solvent is more preferably photopolymerizable. Specific examples thereof include propylene carbonate and butyrolactone. Further, various known dyes and sensitizers may be added in order to improve photopolymerizability. Further, it may be used together with a photoinitiator by heating. A cured heat-curing initiator. In this case, it is expected that after photocuring, polymerization curing of the photopolymerizable compound is further promoted by heating to form a cured product which is completely cured. 'An anisotropic diffusing layer can be formed by curing the above-mentioned photocurable compound alone or by combining a plurality of mixed compositions. Further, by using a photocurable compound and a polymer having no photocurability The anisotropic diffusion layer of the present invention can also be formed by curing the resin. The polymer resin which can be used herein includes an acrylic resin, a styrene resin, a styrene-acrylic copolymer, and a polyaminoguanidine. An acid ester resin, a polyester resin, an epoxy resin, a cellulose resin, a vinyl acetate resin, a vinyl chloride-ethyl acetate copolymer, a polyvinyl butyral resin, etc. These polymer resins and photocurable compounds It is necessary to have sufficient compatibility before curing, but various organic solvents, plasticizers, etc. may be used in order to ensure the compatibility. In addition, in the case of using an acrylate as a photopolymerizable compound, compatibility is obtained. From the viewpoint, an acrylic resin is preferable as the polymer resin. [Procedure] 3239〇2 201241487 Next, I will talk about financial affairs and finance _ Optical _ Manufacturing Green (program). The photocurable composition is applied onto a substrate suitable for a transparent PET film, and a coating film (photocurable resin layer) is provided. The solvent is volatilized by drying as needed, and the dried film has a thickness of from 1 Q to preferably from 20 to (10) (iv) and more preferably from 25 to 5 G/zm. When the thickness of the dried film is less than that, the light diffusion property obtained by the following UV irradiation procedure is insufficient, which is not preferable. On the other hand, in the case where the dry film thickness exceeds 2 m (four), the overall diffusibility is too strong, so that it is difficult to obtain the anisotropy of the features of the present invention, and the cost is increased, which is not suitable for thinning applications, and thus is not preferable. Further, a photosensitive film was produced by laminating a release film and a mask described below on the coating film. (Method of arranging a composition containing a photocurable compound in a sheet form on a substrate) Here, a method of disposing a composition containing a photocurable compound in a sheet form on a substrate is carried out by a usual coating method Printing method. Specifically, it can be used: air knife coating, bar coating, blade coating, blade coating, reverse coating, transfer roll coating, gravure roll coating, light touch roll coating, cast coating, spray coating, nozzle Application such as coating (sl〇t orifice coating), calender coating, dam coating, dip coating, die coating, gravure printing such as gravure printing, or stencil printing such as screen printing, etc. In this case, a crucible of a certain height may be placed around the substrate, and the composition may be cast in the encirclement of the crucible. (Lamination of Mask) In order to effectively form the fine structure of the characteristics of the optical film of the present invention, the film 323902 8 26 201241487 film may be attached to the side of the light irradiation/curable composition layer, and laminated. The dispersion strength in the body is locally changed. The material of the mask is preferably a material in which a light-absorbing filler such as carbon is contained in the polymer-based carbon i, and the opening portion is a material having a structure in which the light can sufficiently penetrate due to a part of the incident light. Further, it is also effective to prevent oxygen from only laminating a usual transparent film on the photocurable composition layer, (light source) rolling hazard, and promoting columnar body formation. A light source for irradiating a composition of a photocurable compound with 3 is usually a short arc ultraviolet light generating source, and specifically, a high pressure mercury lamp, a low pressure mercury lamp, a metal toothed lamp, a xenon lamp or the like can be used. The light to be irradiated to the composition containing the photocurable compound must contain a wavelength capable of curing the photocurable compound, and generally uses light of a wavelength at the center of the mercury lamp. 365 (10) is used to create parallel light 12 from the light of the short-arc UV light. For example, the mirror is disposed behind the light source, and the light is emitted as a point light source at a predetermined value. The Fresnel lens makes the light into parallel light. The Fresnel lens is a lens that divides the normal lens into 16 concentric circles and reduces the thickness, and has a mineral-toothed cross section. The emitted light passes through the Fresnel lens, so the direction of the ray is unified - in the direction, (4) into parallel rays. In order to obtain the parallel ϋ ν emitted light for making the optical film of the invention, Inflammation; ^ must be 3 using the Feyue lens ' 可 ray light which can include the two normal lines of the laser 3239 〇 2 27 201241487 In order to fabricate the optical film of the present invention, the release film on the above photosensitive laminate Or, the mask side illuminates the uv light in the normal direction, and it is important not only to illuminate the parallel rays described above, but also to illuminate the diffused light that is diffused in one direction at the same time. For illuminating such light, for example, it can be used. Lenticular lens °UV parallel light passes through a lenticular to form the above-mentioned light (diffuse light diffused in one direction with parallel rays). In this case, the grating can be diffused in only one direction. The light of the diffused light source (which can mix parallel rays to some extent). Alternatively, the exposure mask can be combined on the grating lens. The grating lens refers to an elongated convex portion having a plurality of semi-cylindrical or arc-shaped shapes. The convex surface formed in parallel, and the opposite side of the convex surface is a flat surface lens (hereinafter, the "semi-cylindrical or arc-shaped elongated convex portion" is simply referred to as a fish plate shape). In the case of an example in which a grating lens is used, the above-mentioned "simultaneous irradiation of parallel rays and diffused rays diffused in one direction" can be understood as a fan shape of a convex portion of a grating lens which is juxtaposed in a fish plate shape. The extended light rays (planar fan-shaped diffusion) are in a state of being aligned in parallel in the longitudinal direction (the diffusion plane is parallel). Fig. 11 shows the manufacture of the optical film of the present invention. A form of the method: The photosensitive laminate 1 is placed in parallel on the grating lens 14 in which the horizontally long semi-circular convex portions 14a are arranged in a longitudinal direction (the release PET or the mask is sequentially arranged from the side close to the lens) The film 18, the photocurable resin layer 20, and the transparent PET 22) are irradiated with the UV parallel rays 12' toward the grating lens 14 in the normal direction of the grating lens 14. The photocurers are obtained. If the UV light passes through the grating lens 14', the light is passed. The torn convex portion 14a diffuses the light 16 in the Y direction, and 323902 28 8 201241487 is irradiated onto the photosensitive laminate 10. If the grating lens is interposed, it is formed in one direction (the Y direction in Fig. 11). There is a wide spread in the direction toward the inside of the paper surface, and there is only a narrow expanded anisotropic light 16 in the direction orthogonal thereto (the X direction in Fig. 11 and the longitudinal direction of the paper). When the photosensitive laminate 10 is irradiated, it is photocured to form a cured resin layer having an internal structure in the photocurable resin layer. (2) Irradiation of UV rays not in the normal direction In another embodiment, parallel rays may be irradiated onto the photosensitive laminate in a direction different from the normal direction. An example of this form is shown in Fig. 12. From the direction opposite to the convex surface (fish plate shape surface) 14a of the grating lens, the illumination is inclined by 30° with respect to the normal direction of the grating lens 14 by parallel rays 12 (having an angle of 60 with respect to the grating lens). At this time, the diffused light 16 from the convex surface 14a of the grating lens is irradiated obliquely. As a result, as shown in the figure, the diffused light 16 is spread in a plane fan shape and is irradiated in the oblique direction of the photosensitive laminate 10, centering on the direction in which the X-axis is inclined by 30° from the normal direction of the photosensitive laminate. Photocuring is carried out in the photocurable layer 20. Further, the above-described UV irradiation method using a grating lens is one of methods for producing the optical film of the present invention, and the present invention is not limited thereto. In summary, in order to form a specific internal structure in the photocurable composition layer, it is important to irradiate the photosensitive laminate with UV light which is expanded into a planar fan shape. Namely, the fine structure having different refractive index of the present invention is formed by irradiating the photocurable resin layer with light extending in a planar fan shape. Further, the irradiated light has a wavelength at which the photosensitive composition can be cured. Further, 323902 29 201241487 In the above-described irradiation step, it is suitable to use light which has diffused parallel rays into a flat fan shape. In the production of the optical film of the present invention, the illuminance of the UV light irradiated onto the photosensitive laminate by the above-described grating lens or the like is preferably 0. (Π to 100 mW/cm 2 , more preferably 〇· The range of 1 to 20 mW/cm 2 . The reason is that if the illuminance is below 0. OlmW/cm 2 , the curing time is low because of curing, and if it is at 100 mW/cm 2 or more, the curing of the photocurable compound is too fast. The formation of the structure becomes unable to exhibit the anisotropic diffusion characteristics of the target. The irradiation time of the UV is not particularly limited, and is 1 to 18 sec, more preferably 30 to 120 sec. Thereafter, by peeling off The release film of the present invention can obtain the opposite-direction diffusing optical film of the present invention. The optical enthalpy of the present invention is formed inside the photocurable composition layer by irradiating the low-intensity UV light for a relatively long period of time as described above. The film obtained by the internal structure. Therefore, in the case of only such uv irradiation, the 'unreacted (tetra) compound component may remain, and sometimes it may become sticky and may be produced in terms of handling property and retractability (4). Next, by additional photos The high-strength uv light of 1000 mW/Cra 2 or more can be used to cure the remaining polymer. The UV irradiation at this time is preferably carried out from the opposite side of the mask side. (Example) The present invention was produced by the following method. Optical film and optical film of Comparative Example. [Example 1 Vertical Irradiation] Photocuring of the formulation shown in Example 3 of JP-A No. 2 323902 8 201241487 514487 was applied to a transparent PET film of 1 Å. The composition is provided with a coating film having a dry film thickness of 50/m, and further, a release PET film is laminated 38 on the coating film in such a manner that the release surface contacts the coating film. The release film is formed on the side of the PET film in a direction of 〇° with respect to the normal, with a grating lens having a radius (r)=0.5 mm and a pitch (P)=〇.5 mm (in a form parallel to the laminate) A parallel UV light of 5 mW/cm 2 (formed using a grating lens) was irradiated for 90 seconds. The optical film of the present invention (transparent PET/) was obtained by peeling off the PET film for release from the cured laminate. Photocurable resin layer) (Refer to Figure 11). UV rays that are transmitted through the grating lens' It is hardly scattered in the X direction (the longitudinal direction of the paper surface) but is parallel, and the scattered light is present in the Y direction (the direction toward the inside of the paper surface). [Embodiment 2 Vertical illumination] In addition to setting the grating lens to be used as a radius The optical film (transparent PET/photocurable resin layer) of the present invention was obtained in the same manner as in Example 1 except that (r) = 〇 · 5 mm and pitch (p): = 0.7 mm. [Example 3 Vertical irradiation The lenticular lens is set to a radius by using an exposure mask having an optical density (10) obtained by coating a PET film with a polyethylene-resin aqueous solution* of dry-dispersed graphite particles of an average particle diameter* instead of the (four) ρ ΕΤ film. The optical film (transparent pΕτ/photocurable resin layer) of the present invention was obtained in the same manner as in Example 1 except that (r> U5 mm, pitch (ρ) = 〇ι surface. [Embodiment 4 oblique irradiation] The direction of irradiation was inclined from the normal direction of the laminate to the X-axis side 323902 31 201241487 30. Except for this, the same operation as in Example 2 was carried out to obtain an optical film (transparent PET/photocurable resin layer) of the present invention (see Fig. 12). Further, the grating lens and the laminate are disposed in parallel. The UV rays irradiated by the grating lens are rays which are inclined by 30 in the X-axis direction and are parallel-scattered in the Y-axis direction. [Comparative Example 1] The same operation as in Example 1 was carried out except that the grating lens was not used, and a comparative optical film (transparent PET/photocurable resin layer) was obtained. Since the grating lens is not passed, the completely parallel rays are irradiated, and an optical film having a columnar microstructure of the type B is obtained. [Comparative Example 2] Commercially available Lumisty (registered trademark, Sumitomo Chemical Co., Ltd.) was used as the optical film having a plate-like fine structure of the type A. [Evaluation 1 Comparison of Optical Curves (Linear Transmittance)] Incident angle dependence was evaluated by using a goniophotometer (GENESIA Gonio/Far Field profiler; manufactured by GENESIA Co., Ltd.) as shown in Fig. 16 . A sample is placed between the light source (not shown) and the light receiver 3, and the linear transmittance of the straight line penetrating sample into the light receiver 3 is measured while changing the angle centering on the straight line L of the sample surface, thereby obtaining a straight line. The penetration rate (in addition, the detailed measurement method I is contained in paragraph 0048 of JP-A-2005-265915). Fig. 13 shows the results regarding Examples 1 to 3 and Comparative Examples 丨 and 2. Further, the results of the second embodiment are the same as those of the first embodiment, and therefore are recorded together. According to the results, the optical films of Examples 1, 2 and 3 had a large value of 323902 32 201241487 in the vicinity of the normal direction, and were ±5 to 10. The incident angle B is at a minimum value Fb from which the incident angle is further enlarged, and the maximum value Fa is obtained at an incident angle a around 40 to 50°. From the optical curve obtained by the measurement, (Fa - Fb) 7 丨 A - B 算出 was calculated and shown in Table 1. [Evaluation 2] Diffuse penetration when rotating a light receiver] The diffuse anisotropy was evaluated by the method shown in Fig. 6 using a goniophotometer. The transmittance of light emitted from the film was measured using the optical film manufactured in the foregoing Examples and Comparative Examples and irradiated with light. In the measurement, in Fig. 6, the light receiver is rotated in the X direction (up and down direction in the paper surface) and the Y direction (in the direction of the paper surface from the near to the far side) centering on the light emission point of the optical film. The results are shown in Figure 14. Calculate Fmaxl/lOX/Fraaxmoy and show it in Table 1 〇 Table 1
Fmaxl/l〇X/Fraaxl/I〇y (Fa-Fb)/ I A-B 1 實施例1 3. 33 1. 39 實施例2 3. 33 1. 39 實施例3 2. 50 1. 67 實施例4 2. 10 1. 02 比較例1 1. 00 0. 37 比較例2 5. 50 2. 85 【圖式簡單說明】 第1圖表示本發明的光學膜所具有的光學曲線的概念 圖。 第2圖表示本發明的光學膜所具有的光學曲線的概念 圖。 第3圖表示本發明的光學膜所具有的性質的概念圖。 32390:2 33 201241487 第4圖表示求本發明的光學膜的散射中心軸的方法。 第5圖表示求本發明的光學膜的散射中心軸的方法。 第6圖表示測角•偏移（g〇ni〇-〇ffset)測定實驗的示 意圖。 第7圖表示本發明的光學膜所具有的異向漫射性。 第8圖表示在膜面的法線方向上照射uv光線而製造 的本發明的光學膜的截面照片。 第9圖表示從偏離膜面的法線方向i〇。的方向上照射 UV光線而製造的本發明的光學膜的截面照片。 第10圖表示從偏離膜面的法線方向45。的方向上照射 UV光線而製造的本發阀的光學膜的截面照片。 第11圖表示本發明的光學膜的製造的一態樣形態的 不意圖。 第12圖表示本發明的光學膜的製造的一態樣形態的 不意圖。 第13圖表示本發明的實施例以及比較例的光學膜的 光學曲線（直線穿透率）的測定結果。 第14圖表示本發明的實施例以及比較例的光學膜的 異向性漫射性（漫射穿透率）的測定結果。 第15圖表示現有技術中的類型a的（具有板狀結構） 光學膜的示意圖。 第16圖表示光學曲線的測定方法。 第17圖表示現有技術申的類型A的光學膜的光學曲 線。 323902 ⑧ 201241487 第18圖表示現有技術中的類型B的（具有柱狀結構） • 的光學膜的示意圖。 , 第19圖表示現有技術中的類型B的光學膜的光學曲 線。 第20圖表示現有技術中的類型b的光學膜的截面的 示意圖。 第21圖表示用以檢測散射中心軸的方法。 第22圖表示現有技術中的類型b的光學膜的漫射的 情形（從法線方向照射UV的情況）。 第23圖表示現有技術中的類型b的光學膜的漫射的 情形（從斜方向照射UV的情況）。 弟24圖表示用以檢測散射中心轴的方法。 第25圖表示現有技術中的類型A的光學膜的漫射的 情形（從涤線方向照射的情況）。 第26圖表示現有技術中的類型a的光學膜的漫射的 情形（從斜方向照射的情況）。 【主 要元件符號說明】 1、50、60光學膜 2 平面 3 光接收器 10 感光性層合體 12 平行光線 14 光柵透鏡 14a 凸部 16 光 18 掩膜 20 光固化樹脂層 22 透明PET 40 板狀結構 51 線狀光源 62 柱狀結構 32390:2 35Fmaxl/l〇X/Fraaxl/I〇y (Fa-Fb)/ I AB 1 Example 1 3. 33 1. 39 Example 2 3. 33 1. 39 Example 3 2. 50 1. 67 Example 4 2. 10 1. 02 Comparative Example 1 1. 00 0. 37 Comparative Example 2 5. 50 2. 85 [Brief Description of the Drawing] Fig. 1 is a conceptual diagram showing an optical curve of the optical film of the present invention. Fig. 2 is a conceptual view showing an optical curve of the optical film of the present invention. Fig. 3 is a conceptual view showing the properties of the optical film of the present invention. 32390:2 33 201241487 Fig. 4 shows a method of obtaining the scattering central axis of the optical film of the present invention. Fig. 5 is a view showing a method of obtaining the scattering central axis of the optical film of the present invention. Fig. 6 shows the schematic of the angle measurement/offset (g〇ni〇-〇ffset) measurement experiment. Fig. 7 shows the anisotropic diffusibility of the optical film of the present invention. Fig. 8 is a photograph showing a cross section of the optical film of the present invention produced by irradiating uv light in the normal direction of the film surface. Fig. 9 shows the normal direction i 偏离 from the deviation from the film surface. A photograph of a cross section of the optical film of the present invention produced by irradiating UV light in the direction. Figure 10 shows the normal direction 45 from the deviation from the film surface. A cross-sectional photograph of the optical film of the hair valve manufactured by irradiating the UV light in the direction. Fig. 11 is a view showing an aspect of the production of the optical film of the present invention. Fig. 12 is a view showing an aspect of the production of the optical film of the present invention. Fig. 13 is a graph showing the measurement results of the optical curves (straight line penetration ratio) of the optical films of the examples and comparative examples of the present invention. Fig. 14 shows the measurement results of the anisotropic diffusibility (diffusion transmittance) of the optical films of the examples of the present invention and the comparative examples. Fig. 15 is a view showing a prior art (having a plate-like structure) optical film of type a. Fig. 16 shows a method of measuring an optical curve. Fig. 17 shows an optical curve of an optical film of the type A of the prior art. 323902 8 201241487 Figure 18 shows a schematic view of an optical film of type B (having a columnar structure) in the prior art. Fig. 19 is a view showing the optical curve of the optical film of the type B in the prior art. Fig. 20 is a view showing a cross section of a prior art optical film of type b. Figure 21 shows a method for detecting the center axis of scattering. Fig. 22 is a view showing a state of diffusion of an optical film of the type b in the prior art (a case where UV is irradiated from the normal direction). Fig. 23 is a view showing a state of diffusion of an optical film of the type b in the prior art (a case where UV is irradiated from an oblique direction). Figure 24 shows a method for detecting the center axis of the scattering. Fig. 25 is a view showing a state of diffusion of the optical film of the type A in the prior art (in the case of irradiation from the rubbing direction). Fig. 26 is a view showing a state of diffusion of the optical film of the type a in the prior art (in the case of irradiation from an oblique direction). [Main component symbol description] 1, 50, 60 optical film 2 Planar 3 optical receiver 10 Photosensitive laminate 12 Parallel light 14 Grating lens 14a Projection 16 Light 18 Mask 20 Photocurable resin layer 22 Transparent PET 40 Plate structure 51 linear light source 62 columnar structure 32390: 2 35