200831951 九、發明說明 【發明所屬之技術領域】 本發明係有關一種光學片、背光裝置及顯示裝置，更 詳細是有關使用於背光裝置的光學片、背光裝置及顯示裝 置。 【先前技術】 在以液晶顯示器爲代表的顯示裝置之領域中，要求提 昇正面亮度。因此，在顯示裝置的背光裝置係使用將來自 面光源的光聚光到正面，提昇正面亮度的光學片。此種光 學片一般是使用日本專利第3262230號所揭示的稜鏡片。 參照第23圖及第24圖，習知的棱鏡片100係在表面 具備互相並排設置的複數個三角柱狀的稜鏡透鏡（以下簡 稱稜鏡）PL。來自面光源的光R100會在稜鏡PL的表面 折射，偏向稜鏡片1 〇〇的法線方向（以下簡稱正面）射出 。像這樣，稜鏡片1〇〇會將擴散光聚光（collimated)到 正面，提昇顯示器畫面的正面亮度。 最近要求正面亮度更爲提昇，提案一種正面亮度高於 習知稜鏡片的技術。在日本特表平1 0-5 06500號公報中， 揭示一種將稜鏡片上下兩片重疊的調整亮度濾片組體。由 於調整亮度濾片組體是重疊兩片稜鏡片，因此正面亮度較 一片稜鏡片更爲提昇。又，認爲由於該調整亮度濾片組體 ，是在各稜鏡片之稜鏡的並排設置方向交叉，重疊各稜鏡 片，因此可調整二軸向（例如顯示器畫面的上下方向及左 -4- 200831951 右方向）的亮度角度依存性。 然而，如果兩片稜鏡片重疊使用’製造製程變煩雜。 又，在習知稜鏡片中，在亮度角度分佈方面，不光是 會在正面產生亮度的峰値，廣角亦會產生亮度的峰値（旁 瓣（si delobe ))。第25圖中的實線，係表示頂角爲9〇 度的棱鏡並排設置在垂直方向的棱鏡片之上下視角的亮度 角度依存性（亮度角度分佈）。橫軸是視角（度），縱軸 是以在面光源上只舖設光擴散板之情形的正面亮度（光擴 散板之法線方向的亮度）爲基準（1.0 )的相對亮度（a.u· )。參照第25圖，雖然在習知稜鏡片中，係在上下視角 的±3 0度的範圍內，表示第1峰値，但與此同時，在視角 + 50度以上、以及視角-50度以下的視角範圍，表示第2 峰値（所謂的旁瓣）。以視角〇度爲峰値，呈現亮度與視 角擴展同時緩慢下降的自然的亮度角度依存性的情形下’ 雖然改變觀看顯示器畫面之使用者觀看的角度亦不會感受 到不適感，但出現如第2 5圖之旁瓣的亮度角度依存性的 情形下，觀看顯示器畫面的使用者就會感受到不適感。因 此，抑制產生旁瓣爲宜。 〔專利文獻1〕日本專利第3 2 6 2 2 3 0號 〔專利文獻2〕日本特表10-506500號公報 【發明內容】 〔發明欲解決之課題〕 本發明之目的是在於提供一種可利用一片進一步提昇 -5 - 200831951 正面亮度，且可調整二軸向的亮度角度依存性的光學片。 本發明之另一目的是在於是提供一可抑制產生旁瓣的 光學片。 〔用以解決課題之手段及發明效果〕 藉由本發明的光學片，係使用於背光。光學片係具備 :片狀的基材部、和複數個第1柱狀透鏡部、和複數個第 2柱狀透鏡部。複數個第1柱狀透鏡部是互相並排設置在 基材部的第1面上。複數個第2柱狀透鏡部是在基材部之 第1面的相反側之第2面上，並排設置成與第1柱狀透鏡 1部交叉，且各個橫斷面形狀爲寬度順著朝向基材部側變 寬的梯形狀。 藉由本發明的光學片，將從外部入射到第2柱狀透鏡 的光線’藉由第2柱狀透鏡部朝基材部法線方向聚光，且 進一步利用第1柱狀透鏡部朝基材部法線方向聚光。因此 ’可利用一片進一步提昇正面亮度。 進而’第1柱狀透鏡部與第2柱狀透鏡部爲互相交叉 。因此，可調整二軸向的亮度角度依存性。 理想是第1柱狀透鏡部是與第2柱狀透鏡部正交。 此時’光學透鏡片，係可調整互相正交的軸向，例如 水平方向與垂直方向的亮度角度依存性。 理想是第2柱狀透鏡部的側面與第2面所呈的角度爲 大於70度、不滿90度。 此時’第2柱狀透鏡部的聚光更爲提昇。因此，可進 -6- 200831951 一步提昇正面亮度。又，可抑制產生旁瓣。 理想是光學片在相鄰的第2柱狀透鏡部之間具有間隙 〇 此時，第2柱狀透鏡部的聚光效果更爲提昇。因此’ 可進一步提昇正面亮度。 理想是第1柱狀透鏡部的橫斷面形狀爲三角形。更佳 是第1柱狀透鏡部的橫斷面形狀係頂角爲鈍角的等腰三角 形。再更佳是頂角爲100度以上、120度以下。 此時，可抑制產生旁瓣。 理想是第1柱狀透鏡部的橫斷面形狀係頂上部分爲帶 圓的等腰三角形，頂上部分爲具有不滿底邊2 0%之曲率半 徑的圓弧。 此時，可抑制產生旁瓣。又，由於頂上部分是帶圓， 因此頂上部分不易產生缺損或變形。 理想是第1柱狀透鏡邰爲柱面鏡（Cylindrical Lenses )部。 此時，可抑制產生旁瓣。 理想是柱面鏡部的凸面與包含柱面鏡部的邊緣之面所 呈的接觸角度爲大於45度、不滿90度。更佳是接觸角度 爲50度以上、70度以下。 此時，可進一步提昇聚光效果。 藉由本發明的背光裝置係具備：面光源、和上述的光 學片。又，藉由本發明的顯示裝置係具備上述的背光裝置 -7- 200831951 【實施方式】 〔用以實施發明的最佳形態〕 以下’參照圖面，詳細的說明本發明之實施形態。在 圖中相同或相等部分，附上相同的符號，不重覆其說明。 [顯示裝置] 爹照第1圖及第2圖，顯示裝置1係具備：背光裝置 1 〇、和舖設在背光裝置1 〇之正面的液晶面板2 0。液晶面 板2 0係具備排列成行列狀的複數個畫素。顯示裝置1的 顯示畫面，係具有左右方向（圖中X方向）爲長邊，且具 有上下方向（圖中y方向）爲短邊的長方形。 [背光裝置] 背光裝置1 〇是所謂的直下型，具備：射出擴散光的 面光源16、和舖設在面光源16上的光學片17。 面光源1 6係具備：外殼1 1、和複數個螢光管1 2、和 光擴散板1 3。外殼1 1係爲在正面具有開口部1 1 〇的框體 ，且在內部收納螢光管1 2。外殼1 1的內側表面，是以反 射濾光片Π 1覆蓋。反射濾光片11 1是用來漫反射從螢光 管1 2射出的光，且將漫反射的光導向開口部1 1 〇。反射 濾光片1 1 1是例如東麗股份有限公司製的RUMIRER (註 冊商標）E60L或E60V，且擴散反射率爲95以上爲宜。 複數個螢光管12，是朝上下方向（第1圖中y方向 -8 - 200831951 )並排設置在外殼11的背面前方。螢光管12是延著左右 方向（第1圖中X方向）的線光源例如冷陰極管。再者， 取代螢光管 12，亦可在外殼 11內收納 LED ( Light E m i 11 i n g D e v i c e )等之複數個點光源。又，亦可收納線光 源與點光源。 光擴散板1 3是嵌入開口部1 1 〇，與外殼1 1的背面並 行排列設置。光擴散板1 3嵌入開口部1 1 0的話，外殻1 1 的內部會被密閉。因此，可防止由螢光管1 2射出的光， 從光擴散板1 3以外之處，漏出外殼1 1，提昇光的利用效 〇 光擴散板1 3會將來自螢光管1 2的光線及利用反射濾 光片1 1 1被反射的光線，大致均勻的擴散射出到正面。光 擴散板1 3係以透明的基材、和分散在基材內的複數個粒 子所構成。分散在基材內的粒子，係爲對可視光範圍之波 長的光之折射率與基材不同。因此，光擴散板1 3係用來 擴散入射的光，且已擴散的光會穿透光擴散板1 3。光擴 散板1 3的基材是例如由：玻璃、聚酯系樹脂、聚碳酸脂 系樹脂、聚丙烯酸酯系樹脂、脂環族聚烯烴系樹脂、聚苯 乙;^希系樹脂、聚氯乙烯系樹脂、聚乙酸乙烯酯系樹脂、聚 T燒磺酸鹽系樹脂、三醋酸硝化纖維素系樹脂等的樹脂所 製成。雖然第2圖所示的光擴散板1 3的表面爲平面，但 也可以不是平面，形成供產生擴散效果的凹部。 [光學片；| -9- 200831951 參照第3圖〜第5圖，光學片17是片狀或薄膜狀。 光學片1 7係具備：基材部21、形成在基材部2 1之一方 的面2 1 3上的稜鏡層1 8、和形成在基材部2 1之另一方的 面2 1 4上的梯形柱狀透鏡層1 9。光學片1 7係梯形柱狀透 鏡層1 9與面光源1 6相對，稜鏡層1 8係是在面光源1 6上 舖設成與液晶面板2 0相對。 基材部2 1是片狀或薄膜狀，對可視光範圍的波長而 言爲透明。基材部2 1是例如以：玻璃、聚酯系樹脂、聚 碳酸脂系樹脂、聚丙烯酸酯系樹脂、脂環族聚烯烴系樹脂 、聚苯乙烯系樹脂、聚氯乙烯系樹脂、聚乙酸乙烯酯系樹 脂、聚丁烯磺酸鹽系樹脂、三醋酸硝化纖維素系樹脂等的 樹脂所構成。 稜鏡層1 8係具備形成在面2 1 3上的片狀副基材部 2 1 1與形成在副基材部2 1 1上的複數個稜鏡透鏡部（以下 簡稱稜鏡部）22。總之，稜鏡部22是形成在面213側。 各稜鏡部2 2是朝左右方向（圖中X方向）延伸的柱狀透 鏡，其橫斷面爲三角形。複數個稜鏡部22係互相並排設 置在上下方向（圖中y方向）。總之，各稜鏡部22是與 並設方向略垂直的延伸。 稜鏡部22是將從基材部2 1入射的光聚光到正面（基 材部2 1的法線方向）而射出。此時，由於稜鏡部22是朝 上下方向排列，因此主要是調整上下方向的亮度角度依存 性，提昇正面亮度。 複數個稜鏡部22與副基材部2 1 1是形成一體，該等 -10- 200831951 是利用相同的樹脂所構成。具體而言，複數個稜鏡部22 及副基材部2 1 1是利用電離放射線硬化樹脂所構成。在此 ’電離放射線硬化樹脂是利用紫外線或電子線時的電離放 射線硬化的樹脂，例如：聚酯系丙烯酸樹脂、聚胺脂系丙 烯酸樹脂、聚醚系丙烯酸樹脂、環氧系丙烯酸樹脂、聚酯 系甲基丙烯酸樹脂、聚胺脂系甲基丙烯酸樹脂、聚醚系甲 基丙烯酸樹脂、環氧系甲基丙烯酸樹脂。 梯形柱狀透鏡層1 9係具備：形成在面2 1 4上的片狀 副基材部2 1 2、和形成在副基材部2 1 2上的複數個梯形柱 狀透鏡部24。梯形柱狀透鏡部24係爲朝上下方向（第1 圖中的y方向）延伸的柱狀，其橫斷面形狀爲寬度順著朝 向面214擴大的梯形。總之，如第5圖所示，梯形柱狀透 鏡部2 4的橫斷面形狀的底表面2 1 8的寬度W 2是較梯形 柱狀透鏡部24之兩邊緣ED間的寬度W3短。 梯形柱狀透鏡部24是互相並排設置在左右方向（第 1圖中的X方向）。總之，梯形柱狀透鏡部24是與稜鏡 部22正交。換言之，梯形柱狀透鏡部24的並設方向，是 與稜鏡部22的並設方向正交。 梯形柱狀透鏡部24，是將來自面光源1 6的擴散光聚 光到正面方向，提昇正面亮度。此時，由於稜鏡部24是 朝左右方向排列，因此主要是調整左右方向的亮度角度依 存性，提昇正面亮度。 在第3圖〜第5圖中，雖然在相鄰的梯形柱狀透鏡部 24之間設有間隙2 1 5，但相鄰的梯形柱狀透鏡部24可以 -11 - 200831951 互相接觸。總之，相鄰的梯形柱狀透鏡部2 5的 彼此接觸，也可以沒有間隙2 1 5。但如後所述，由 間隙2 1 5可提昇正面亮度，因此設置間隙2 1 5爲宜 梯形柱狀透鏡部24及副基材部2 12是形成一 等是利用相同的電離放射線硬化樹脂所構成。 在光學片17中，稜鏡部22是將來自面光源 散光線中朝上下方向的擴散光加以聚光，且梯形柱 部24是將來自面光源1 6之擴散光線中朝左右方向 光加以聚光。因此，藉由棱鏡部22的聚光功能及 狀透鏡部24的聚光功能的綜效（Synergy)，一片 1 7的正面亮度，就會高於習知的稜鏡片的正面亮 ，由於並排設置在上下方向的稜鏡部22是將上下 擴散光線加以聚光，且並排設置在左右方向的梯形 鏡部2 4是將左右方向的擴散光線加以聚光，因此 二軸向（上下方向及左右方向）的亮度角度依存性 進而，由於梯形柱狀透鏡部24的聚光效果， 鏡部2 2的聚光效果，因此能抑制亮度隨著左右方 度角度依存性之視角變化的改變。因此，對左右方 角的亮度角度分佈比對上下方向之視角的亮度角度 廣（總之，左右視角比上下視角還廣）。 當使用者觀看顯示裝置1的顯示器畫面時，從 向觀看的機會多於從上下斜向觀看的機會。因此， 方向的視角變化而Η，売度變化太大的話，從左右 看顯示器畫面的使用者有感到不適的情形。原因在 S緣ED 於設置 〇 體，該 16之擴 狀透鏡 的擴散 梯形柱 光學片 度。又 方向的 柱狀透 可抑制 〇 小於棱 向之亮 向之視 分佈還 左右斜 對左右 斜向觀 於只要 -12- 200831951 稍微改變觀看的角度，亮度就會急遽的變化。若使用光學 片1 7，由於能抑制亮度隨著左右視角變化的改變，因此 使用者不易感到不適，可實現應用於顯示裝置的亮度角度 依存性。 稜鏡部22的橫斷面形狀以角形爲宜，頂角0 40以鈍 角爲宜。頂角爲90度時，亮度角度分佈產生明顯的旁瓣 。稜鏡部22的頂角0 40爲鈍角的話，旁瓣受抑制。爲了 抑制旁瓣，且提昇正面亮度，頂角以100度〜120度爲宜 〇 爲了抑制旁瓣，稜鏡部22的頂上可以形成帶圓。總 之，稜鏡部22的橫斷面形狀之中，頂上可以具有曲率。 此時，儘可能抑制旁瓣，就能抑制稜鏡頂上部缺損。理想 是頂上的橫斷面形狀爲圓弧，更好是具有不滿稜鏡部22 之橫斷面形狀之底面的長度W4之20%的曲率半徑之圓弧 〇 梯形柱狀透鏡部24，是將左右方向的擴散光聚光， 藉此有助於提昇正面亮度。藉由梯形柱狀透鏡部24，即 使稜鏡部22的頂角0 40爲鈍角亦可得到較高的正面亮度 〇 第6圖及第7圖是表示光學片1 7之梯形柱狀透鏡部 24之形狀與正面亮度之關係的圖。第6圖及第7圖的橫 軸是梯形柱狀透鏡部24的側面24 1與包含梯形柱狀透鏡 部24之兩邊緣ED的面216所呈的角度0 10。又，縱軸 是以具有頂角90度之稜鏡的稜鏡片之正面亮度爲基準（ -13- 200831951 =1.0 )時的光學片1 7之正面亮度比。再者，使用於調查 的光學片之稜鏡部22的頂角0 40是形成1 10度。 在第6圖中，相對於相鄰的梯形柱狀透鏡部24間的 間隙215之寬度W1的梯形柱狀透鏡部24之底表面218 的寬度W2之比（W1/W2)爲1.0形成既定，且寬度W1 値及W 3値爲既定，改變角度0 1 〇。總之，寬度W1及 W3爲既定，改變梯形柱狀透鏡部24的高度T0，並改變 角度0 10。 另一方面，在第7圖中，W1/W2爲1.0形成既定， 梯形柱狀透鏡部2 4的高度T 0亦爲既定，改變角度θ 1 〇。 總之，高度T0爲既定，改變寬度W1値及W2値，藉此 改變角度Θ 1 0。 參照第6圖及第7圖，角度010爲90度以下時，雖 然第6圖及第7圖都是正面亮度比大致一定（第6圖）， 或者正面亮度比不會隨著角度0 10的上昇而下降（第7 圖），但角度010超過70度的話，正面亮度比會急遽的 上昇。又，角度Θ10大於70度時，左右視角之亮度角度 分佈的旁瓣，明顯較習知的稜鏡片更受到抑制。 自以上，角度（910大於70度的話，正面亮度會比只 形成棱鏡層18的光學片更爲提昇。進而，爲72度以上的 話，即使稜鏡部22的頂角爲鈍角，亦可得到比頂角90度 之稜鏡片更高的正面亮度，且亦可抑制上下方向及左右方 向產生旁瓣。更佳是角度Θ10爲72.5度以上、不滿90度 。此時，可得到更高的正面亮度。 -14- 200831951 雖然相鄰的梯形柱狀透鏡部24即使互相接觸亦可達 到上述的效果，但如第3圖〜第5圖所示，在相鄰的梯形 柱狀透鏡部24之間設置間隙2 1 5，正面亮度會更提昇。 第8圖是表示間隙215之寬度與正面亮度之關係的圖。第 8圖的橫軸是表示Wl/ W2。又縱軸係與第6圖及第7圖 相同，表示正面亮度比。使用於調查的光學片17之角度 010是形成80度，稜鏡部22的頂角040是形成11〇度 〇 參照第8圖，正面亮度比係W1/W2自0起愈大愈高 ，Wl / W2 = 0.7，表示峰値。另一方面，大於 W1 / W2 = 0.7的話，正面亮度會慢慢下降。但沒有間隙215時 (Wl/W2 = 0)，正面亮度亦會大於1。 自以上，爲了提昇正面亮度，設置間隙2 1 5爲宜。如 果考慮第8圖之正面亮度比的峰値部分，更好係W 1 / W2 爲〇. 1以上、4以下。 [光學片的其他形態] 如第9圖〜第11圖所示，光學片17亦可在基材部 21的面213上，設置陣列透鏡（Lenticular Lens)層25 以取代稜鏡層1 8。 陣列透鏡層2 5係具備副基材部2 1 1與並排設置在上 下方向的複數個柱面鏡部2 3。副基材部2 1 1及柱面鏡部 23是形成一體，該材質是電離放射線硬化樹脂。柱面鏡 部2 3是將從基材部2 1入射的光聚光到正面，射出外部。 -15- 200831951 總之，柱面鏡部23具有聚光功能。 第1 0圖的柱面鏡部23的橫斷面形狀爲弓狀。具體 ，柱面鏡部2 3的頂上部分爲圓弧，頂上部分至邊緣 之間的部分（邊緣附近部分）是相當於頂上部分之圓弧 點之接線的直線。柱面鏡部23的橫斷面形狀，可爲如 1 0圖的弓狀，亦可爲圓弧，或橢圓弧。 又，在第1 〇圖中，雖然相鄰的梯形柱狀透鏡部23 互相接觸，但亦可在相鄰的梯形柱狀透鏡部23之間設 間隙。 陣列透鏡層2 5係與稜鏡層1 8相同，會將上下方向 擴散光線聚光，提昇正面亮度。因此，取代稜鏡層18 有陣列透鏡層的光學片1 7，亦具有與設有稜鏡層1 8之 學片1 7相同的效果。進而，由於柱面鏡部23，爲表面 有曲率的凸面23 0，因此能較稜鏡部22更加抑制旁瓣。 在柱面鏡部23中，包含該邊緣ED的面（總之， 基材部211的上面）與柱面鏡部23之凸部23 0所呈的 度（以下稱接觸角度）0 20愈大、聚光效果更高。柱 鏡部23之最佳接觸角度0 20爲45度以上、不滿90度 更佳是接觸角度0 20爲50度以上、70度以下。 在上述實施形態中，雖然梯形柱狀透鏡部24的並 方向是與稜鏡部22及柱面鏡部23之並設方向正交，但 需要嚴格的正交，只要交叉成可達到本發明之效果的程 ，總之，能調整上下方向及左右方向之亮度角度依存性 提昇正面亮度的程度就可以。 上 ED 端 第 是 置 的 具 光 具 副 角 面 設 不 度 -16- 200831951 又’稜鏡部2 2及柱面鏡部2 3、和副基材部21 1及 2 1 2、和梯形柱狀透鏡部24，可利用與基材部2丨相同的 材質所構成。又，取代電離放射線硬化樹脂，可使用熱硬 化性樹脂、熱可塑性樹脂。 也可以沒有副基材部2 1 1及2 1 2。總之，也可以在基 材部2 1直接形成稜鏡部22或柱面鏡部23、和梯形柱狀 透鏡部24。又，基材表面可以賦形。 雖然上述相鄰的梯形柱狀透鏡部22是互相接觸，但 亦可在相鄰的梯形柱狀透鏡部22之間設置間隙。 梯形柱狀透鏡部24的橫斷面形狀，可以不是嚴格的 梯形。例如，在梯形柱狀透鏡部24中，底表面218可不 與包含兩邊緣ED的面216嚴格的並行。又，雖然圖示的 底表面2 1 8實際是平面，但可以稍微的凹凸。 雖然第1圖及第2圖所示的背光裝置10是直下型， 但也可以在側邊型（edge light )的背光裝置使用光學片 17。 [製造方法] 說明利用捲對捲（roll-to-roll )方式的製造方法，作 爲上述之光學片1 7的製造方法之一例。以下雖是說明具 有稜鏡層1 8的光學片1 7之製造方法，但連具有陣列透鏡 層2 5的光學片1 7亦能以同樣的方法製造。 在捲對捲方式中，是先在基材部2 1上形成梯形柱狀 透鏡層1 9 (第1製程），接著在基材部21上形成稜鏡層 -17- 200831951 1 8 (第2製程）。 首先，說明有關第1製程。準備：在表面朝周方向捲 繞著相當於基材部21之基層薄膜的圓筒狀的第1滾筒、 和供捲取形成梯形柱狀透鏡層1 9之基層薄膜的圓筒狀的 第2滾筒、和用以形成梯形柱狀透鏡層1 9之圓筒狀的梯 形柱狀透鏡用滾版。 梯形柱狀透鏡用滾版，是在表面具有梯形柱狀透鏡部 24的轉印用溝槽。各轉印用溝槽是朝著滾版的軸向延伸 ，互相排列在周方向。轉印用溝槽的橫斷面形狀，是對應 梯形柱狀透鏡部24的橫斷面形狀。 以軸向互相並行的方式，配置第1滾筒、梯形柱狀透 鏡用滾版、第2滾筒。配置後，在梯形柱狀透鏡用滾版的 轉印用溝槽塡充電離放射線硬化樹脂。 塡充後，讓第1滾筒廻轉，送出基層薄膜，從第1滾 筒向著梯形柱狀透鏡用滾版運送基層薄膜。接著，讓梯形 柱狀透鏡用滾版廻轉，將塡充到轉印用溝槽的電離放射線 硬化樹脂轉印到已被運送出的基層薄膜上。此時，一面利 用與梯形柱狀透鏡用滾版相對配置的備用滾筒與梯形柱狀 透鏡用滾版夾持基層薄膜、一面將電離放射線硬化樹脂轉 印到基層薄膜上。藉由照射電離放射線來硬化所轉印的電 離放射線硬化樹脂，在基層薄膜上形成梯形柱狀透鏡層 19° 將已形成有梯形柱狀透鏡層1 9的基層薄膜（以下稱 中間生成薄膜）捲繞到第2滾筒，結束第1製程。此時， -18- 200831951 梯形柱狀透鏡部24是排列在第2滾筒的周方向。 結束第1製程後，開始第2製程。在第2製程中，準 備：第2滾筒、用以形成稜鏡層1 8的圓筒狀的稜鏡用滾 版、以及供捲繞已製造的光學片1 7的第3滾筒。 稜鏡用滾版是在其表面具有複數個稜鏡轉印用溝槽（ 以下簡稱轉印用溝槽）。轉印用溝槽的橫斷面形狀，是對 應稜鏡部22的橫斷面形狀。各轉印用溝槽是朝著稜鏡用 滾版的周方向延伸，排列在軸向。 與第1製程同樣的，在轉印用溝槽塡充電離放射線硬 化樹脂。接著，讓第2滾筒廻轉，向著棱鏡用滾版運送中 間生成薄膜。此時，中間生成薄膜之中，是以與形成梯形 柱狀透鏡層1 9的面2 1 3相反側的面2 1 4接觸稜鏡用滾版 之表面的方式來運送中間生成薄膜。 利用備用滾筒將從第2滾筒運送來的中間生成薄膜按 壓在稜鏡用滾版表面，一面在備用滾筒與稜鏡用滾版之間 夾持中間生成薄膜、一面將塡充到轉印用溝槽的電離放射 線硬化樹脂轉印到中間生成薄膜。此時，雖然備用滾筒會 接觸到梯形柱狀透鏡部24的底表面2 1 8，但由於底表面 218實際上爲平面，因此梯形柱狀透鏡部24的形狀不易 因備用滾筒變形。 藉由照射電離放射線來硬化電離放射線硬化樹脂，形 成稜鏡層1 8。藉由以上製程所製造的光學片1 7，係捲繞 在第3滾筒。 上述製程之中，也可在第2製程形成陣列透鏡層25 -19- 200831951 ，取代形成稜鏡層1 8。陣列透鏡層2 5的製造方法，係與 稜鏡層1 8的製造方法相同。但，使用在表面具有對應柱 面鏡部23之柱面鏡轉印用溝槽的柱面鏡用滾版，取代稜 鏡用滾版。 在上述的製造方法中，雖是先形成梯形柱狀透鏡層 1 9，接著形成稜鏡層1 8或陣列透鏡層2 5 (以下將此簡稱 稜鏡層1 8等），但形成稜鏡層1 8後，也可形成梯形柱狀 透鏡層1 9。但先形成梯形柱狀透鏡層1 9爲宜。先形成稜 鏡層1 8時，當轉印製造梯形柱狀透鏡層1 9之製程中的電 離放射線硬化樹脂時，稜鏡部22 (或柱面鏡部23 )的頂 點有與備用滾筒接觸變形之虞。因此，如上所述，先形成 即使接觸備用滾筒亦不易變形的梯形柱狀透鏡部24爲宜 〇 在上述的製造方法中，雖是使用梯形柱狀透鏡轉印用 溝槽排列在周方向的滾版、和稜鏡轉印用溝槽排列在軸向 的滾版，但也可使用梯形柱狀透鏡轉印用溝槽排列在軸向 的滾版、和稜鏡轉印用溝槽排列在周方向的滾版。又，如 果梯形柱狀透鏡轉印用溝槽的排列方向與稜鏡轉印用溝槽 的排列方向是正交，梯形柱狀透鏡轉印用溝槽及稜鏡轉印 用溝槽的排列方向就未特別限制。然而，如果使用梯形柱 狀透鏡轉印用溝槽及棱鏡轉印用溝槽之一者爲排列在周方 向，另一者爲排列在軸向的梯形柱狀透鏡用滾版及稜鏡用 滾版，製造良品率最高。 又，也可爲將形成梯形柱狀透鏡層1 9的中間生成薄 -20- 200831951 膜，運送到稜鏡用滾版，形成稜鏡層之後，捲繞到第2滾 筒的連續形成。 再者，取代棱鏡層1 8，形成陣列透鏡層2 5時，柱面 鏡轉印用溝槽排列在軸向爲宜，梯形透鏡轉印用溝槽排列 在周方向爲宜。如果將柱面鏡轉印用溝槽排列在周方向’ 轉印在基層薄膜的電離放射線硬化樹脂就會有因柱面鏡轉 印用溝槽的邊緣被除去的可能性。 以上雖是說明有關光學片1 7的製造方法，但即使藉 由與上述捲對捲方式相異的其他方法亦可製造光學片17 。例如，也可使用板狀的版，來形成稜鏡層1 8、陣列透 鏡層2 5及梯形柱狀透鏡層1 9。又，也可藉由擠壓法、熱 壓法、射出成型法等製造。 〔實施例1〕 製造不同的形狀尺寸之複數個光學片1 7 ’與習知的 稜鏡片一起調查亮度角度依存性（亮度角度分佈）° 藉由上述的捲對捲法製造表1所標示的形狀尺寸之本 發明例1〜5的光學片。本發明例1、4及5的光學片，係 對應第3圖〜第5圖所示的光學片，具有稜鏡層。表1中 的本發明例1、4及5的各項目（W2、0 1 0等），對應第 3圖〜第5圖內的符號。另一方面，本發明例2及3 ’係 對應第9圖〜第1 1圖所示的光學片，具有陣列透鏡層。 表1中的本發明例2及3的各項目，對應第9圖〜第11 圖內的符號。 -21 _ 200831951 in 〇 § 00 ^Τ) (Ν ο r-H 17.5 I 1 1 應 瞧 1.16 發明例4 〇 78.8 12.5 〇 (Ν Ο r—Η τ—Η 16.4 1 I 1 1 τ-Η r-H 發明例3 〇 78.7 12.5 〇 (Ν 1 I 1 1 卜 〇 23.7 Ό Τ*Η τ-Η (N 孽 〇 § 寸 〇 tn (Ν 1 1 1 I § 23.3 1.16 鹬 比較例 1 1 1 1 1 1 1 1 1 1 1 Η r-H 〇 g 寸 〇 (Ν ο Η 17.5 1 届 1 1 1 IT) 粼 (//m) £ (Urn) (urn) (//m) (度） (//m) (//m) (//m) (μπι) (度） (//m) (//m) 項目 底表面寬度W2 角度010 高度το 間隙寬W1 間距Ρ〇 頂角0 40 高度τι 頂部曲率半徑 間距P1 頂部曲率半徑R0 接觸角度0 20 高度T2 間距P2 正面亮度比 梯形柱狀透鏡部 稜鏡部 柱面鏡部 結果 -22- 200831951 參照表1，本發明例1、4、5的稜鏡部的橫斷面形狀 爲等腰三角形。但在本發明例4中，稜鏡部的頂上帶圓， 帶圓的頂上部的曲率半徑爲5 /z m。 本發明例2的柱面鏡部的橫斷面形狀爲弓狀，柱面鏡 部的橫斷面形狀之中，邊緣附近部分爲直線。另一方面， 本發明例3的柱面鏡部的橫斷面形狀，係以長軸之端點爲 頂點的橢圓弧。 本發明例1〜5的光學片中，基材部是使用厚度250 的聚對苯二甲酸乙二酯（PET )薄膜。又，在棱鏡層 、陣列透鏡層及梯形柱狀透鏡層，使用紫外線硬化樹脂的 丙烯酸系紫外線硬化樹脂，藉由紫外線的照射使其硬化。 比較例的稜鏡片是藉由以下的方法製造。厚度250 // m的PET薄膜上藉由塗佈法均勻的塗佈丙烯酸系紫外 線硬化樹脂，形成厚度3 0 // m的紫外線硬化樹脂層。接 著，一面將稜鏡用滾版壓抵在紫外線硬化樹脂層、一面照 射紫外線，製造第23圖及第24圖所示之形狀的稜鏡片。 如標示於表1，稜鏡片的稜鏡之間距爲5 0 // m，頂角爲9 0 度。 [亮度角度分佈調查] 調查已製造的本發明例1〜5的光學片及比較例的稜 鏡片之亮度角度依存性（亮度角度分佈）。收納冷陰極管 ，在內面舖設反射薄膜，在開口部嵌固著光擴散板的外殼 ，舖設本發明例1的光學片。此時，以梯形柱狀透鏡部面 -23- 200831951 對外殼之光擴散板的方式，來舖設光學片。梯形柱狀透鏡 部的並設方向是左右方向，稜鏡部的並設方向是上下方向 〇 在外殻舖設本發明例1的光學片後，調查亮度角度分 佈。視角係以光學片的法線方向（正面）爲0度軸，由0 度軸朝上下方向的傾角爲上下視角，由0度軸朝左右方向 的傾角爲左右視角。藉由亮度計來測定各上下視角及左右 視角的亮度。亮度之測定處係光學片表面的中央。 與本發明例1之光學片同樣的，連有關其他本發明例 2〜5的光學片亦調查亮度角度分佈。 另一方面，將比較例的稜鏡片舖設在外殻，調查亮度 角度分佈。此時，以稜鏡的並設方向爲上下方向的方式舖 設在外殼。 其中於第12圖表示本發明例1的光學片之亮度角度 分佈，於第13圖表示本發明例2的光學片之亮度角度分 佈，於第1 4圖表示本發明例3的光學片之亮度角度分佈 ，於第15圖表示本發明例4的亮度角度分佈’於第16圖 表示本發明例5的亮度角度分佈。又，於第2 5圖表示比 較例的稜鏡片之亮度角度分佈。第12圖〜第16圖及第 2 5圖的橫軸是視角（度），縱軸是以外殼的光擴散板之 正面亮度（光擴散板之法線方向的亮度）爲基準（1 ·0 ) 的相對亮度（a.u.)。又，圖中實線是上下視角的亮度角 度分佈，圖中虛線是左右視角的亮度角度分佈。 於表1標示由本發明例1〜5的各亮度角度分佈所得 -24- 200831951 到的視角〇度的相對亮度（正面亮度）X1，相對於由比 較例的亮度角度分佈所得到的正面亮度X2之比（X1/X2 :以下稱爲正面亮度比）。 參照第12圖〜第16圖、第25圖及表1，本發明例1 〜5的光學片之正面亮度，均高於比較例的棱鏡片，其正 面亮度比爲1.11〜1.16。進而，本發明例1〜5的上下及 左右視角的旁瓣（在廣角所產生的亮度峰値）較小，旁瓣 可抑制的較比較例更低。 進而，本發明例1〜5的亮度角度分佈中，相對於視 角較廣的亮度，其下降係左右視角比上下視角緩慢，左右 視角爲自然的配向分佈。換言之，亮度角度分佈之中的最 大相對亮度値（峰値）與最小相對亮度値之差，係左右視 角比上下視角小，左右視角的亮度角度分佈比上下視角寬 。再者，具備柱面鏡層的本發明例2及3，相對於視角較 廣的亮度，其下降連上下視角亦很緩慢，不光是左右視角 ，上下視角也呈現自然的配向分佈。 〔實施例2〕 調查光學片之梯形柱狀透鏡層之中，對相鄰的梯形柱 狀透鏡間的間隙寬W 1之變化的正面亮度之改變。具有稜 鏡層的光學片之中’製造具有各種間隙寬W 1的複數個光 學片。間隙寬w1以外之光學片的其他形狀尺寸，係與本 發明例1、2的光學片相同。 針對已製造的光學片，求得正面亮度，且求得實施例 -25- 200831951 1相對於比較例之稜鏡片的正面亮度之比（正面亮度比） 〇 於第8圖表示調查結果。橫軸是w 1 / W2，縱軸是正 面亮度比。參照第8圖，在改變W1 / W2的所有區域，正 面亮度比大於1.0。進而，正面亮度比係W1/W2自0起 愈大愈高，W1 / W2 = 0.7，表示峰値，0.7以後慢慢下降。 〔實施例3〕 光學片的梯形柱狀透鏡層之中，調查相對於角度0 1 0 之變化的正面亮度之改變。首先，間隙寬W 1相對於底表 面W2之比（W1/W2)爲1.0形成既定，且寬W1及W2 的値爲既定，製造改變角度0 10的複數個光學片。具體 而言，梯形柱狀透鏡部的高度T 0互不相同，藉此製造具 有不同之角度0 10的複數個光學片。高度T0及角度0 10 以外的梯形柱狀透鏡層的形狀尺寸及棱鏡層的形狀尺寸， 係與本發明例1、2相同。以下，該等的光學片稱爲高度 變動光學片。 另一方面，製造W1/W2爲1.0形成既定，梯形柱狀 透鏡邰24的高度T0亦爲既定，改變角度0 1〇的複數個 光學片。具體而言，寬W1及W2之値不同，藉此製造具 有不同之角度0 10的複數個光學片。寬度Wi、W2及角 度Θ 1 0以外的梯形柱狀透鏡層的形狀尺寸及棱鏡層的形 狀尺寸，係與本發明例1、2相问。以下，該等的光學片 稱爲高度固定光學片。 -26 - 200831951 針對已製造的高度變動光學片及高度固定光學片，求 得正面亮度，且求得實施例1相對於比較例之正面亮度的 比（正面亮度比）。 於第6圖及第7圖表示調查結果。第6圖是以高度變 動光學片所得到的正面亮度比，第7圖是以高度固定光學 片所得到的正面亮度比。第6圖及第7圖均是橫軸爲角度 Θ 1 0 (度），縱軸爲正面亮度比。 雖然角度010不滿70度時，正面亮度比與角度010 的增大無關，大致爲既定（第6圖），或是隨著角度010 的增大同時減少（第7圖），但角度0 1 0爲70度以上的 話，正面亮度比會急遽上昇。 再者，調查各光學片的亮度角度分佈的結果，角度 0 1 〇爲7 0度以上時，左右視角的旁瓣可抑制的較習知的 稜鏡片之上下視角的旁瓣低。另一方面，角度010爲不 滿70度時，左右視角的旁瓣發生程度與習知之稜鏡片的 上下視角相同。於第17圖表示角度010爲60度的高度 變動光學片的亮度角度分佈，且作爲一例。 〔實施例4〕 光學片的稜鏡層之中，調查有關棱鏡部的頂角0 40 與正面亮度比及旁瓣的關係。 製造頂角不同的複數個光學片。光學片之稜鏡層的尺 寸形狀之中，固定間距，改變高度並改變頂角。具體上製 造高度τ 1及頂角0 4 0不同，其他形狀尺寸與本發明例1 -27- 200831951 的稜鏡部相同的複數個光學片。再者，各光學片的梯形柱 狀透鏡層及基材部的形狀尺寸等係與本發明例3、4相同 〇 針對已製造的複數個光學片，求得正面亮度，且求得 實施例1相對於比較例之正面亮度的比（正面亮度比）。 進而，針對各光學片調查亮度角度分佈，確認有無旁瓣。 於弟18圖表不g周查結果。弟18圖的橫軸爲頂角04〇 (度），縱軸爲正面亮度比。如第1 8圖所示，正面亮度 比係頂角0 4 0愈小愈高。然而，頂角愈小，旁瓣產生愈 明顯。於第19圖表示頂角Θ40爲90度的光學片之亮度 角度分佈，於第20圖表示頂角040爲100度的光學片之 亮度角度分佈。參照第19圖及第20圖，在頂角040爲 90度的光學片（第1 9圖）中，對上下視角的旁瓣產生程 度與比較例的稜鏡片相同而言，在頂角0 40爲100度的 光學片（第20圖）中，可抑制上下視角的旁瓣。 〔實施例5〕 調查有關相對於稜鏡部的頂上部分爲一定的曲率半徑 並帶圓的光學片之曲率半徑之變化的正面亮度之改變。 製造稜鏡部的頂角0 40及間距P 1與本發明例4的棱 鏡部相同，頂上部的曲率半徑不同的複數個光學片。再者 ，各光學片的梯形柱狀透鏡部及基材部的形狀尺寸等係與 本發明例3、4相同。 針對已製造的光學片，求得正面亮度，且求得實施例 -28 - 200831951 1相對於比較例之稜鏡片的正面亮度之比（正面亮 〇 於第2 1圖表示調查結果。第2 1圖中的橫軸是 稜鏡的底邊W4的頂上部分之曲率半徑的比（以下 率半徑比），縱軸是表示正面亮度比。如第21圖 曲率半徑比愈小，正面亮度比愈高。 〔實施例6〕 調查有關相對於柱面鏡部的接觸角度0 20之變 正面亮度之改變。 製造柱面鏡部的頂部曲率半徑R0及間距P2 例3相同，柱面鏡部的接觸角度0 2 0不同的複數個 片。各光學片的梯形柱狀透鏡部及基材部的形狀尺寸 與本發明例3、4相同。 針對已製造的光學片，求得正面亮度，且求得實 1相對於比較例之棱鏡片的正面亮度之比（正面亮度 〇 於第22圖表示調查結果。第22圖中的橫軸是表 觸角度0 20，縱軸是表示正面亮度比。如第2 1圖所 正面亮度隨著接觸角度0 20變大而提昇，接觸角度 爲60度以上的話，正面亮度比之上昇漸縮，大致一 ί 以上雖是說明本發明的實施形態，但上述實施形 過是爲了實施本發明的舉例示範。因而，本發明並不 上述的實施形態，在不脫離其主旨的範圍內可適當變 比） 示對 爲曲 示， 化的 發明 光學 等係 施例 比） 示接 示， Θ 20 r 〇 態不 限於 形實 -29- 200831951 施上述的實施形態。 【圖式簡單說明】 第1圖是具備本發明藉由實施形態的光學片的顯示裝 置的立體圖。 第2圖是第1圖中的II 一 π線之剖面圖。 弟3圖是第2圖中的光學片的立體圖。 桌4圖是第3圖中的IV — IV線之剖面圖。 第5圖是第3圖中的V — V線之剖面圖。 第6圖是表示第3圖所示的光學片中之梯形柱狀透鏡 部之形狀與正面亮度之關係的圖。 第7圖是表示與第6圖不同的梯形透鏡部之形狀與正 面亮度之關係的其他圖。 第8圖是第3圖所示的光學片，表示相鄰的梯形透鏡 部間的間隙與正面亮度之關係的圖。 第9圖是與第3圖不同的其他光學片的立體圖。 第1 〇圖是第1 0圖中的X — X線之剖面圖。 第1 1圖是第1 0圖中的XI — XI線之剖面圖。 第12圖是表示實施例1中的本發明例1之光學片的 亮度角度依存性的圖。 第1 3圖是表示實施例1中的本發明例2之光學片的 亮度角度依存性的圖。 第1 4圖是表示實施例1中的本發明例3之光學片的 亮度角度依存性的圖。 -30- 200831951 第1 5圖是表示實施例1中的本發明例4之光學片的 亮度角度依存性的圖。 第16圖是表示實施例1中的本發明例5之光學片的 亮度角度依存性的圖。 第17圖是表示實施例3所製造的光學片之亮度角度 依存性的圖。 第18圖是表示光學片的稜鏡之頂角與正面亮度之關 係的圖。 第19圖是表示實施例4所製造的光學片之亮度角度 依存性的圖。 第20圖是表示實施例4所製造的光學片’表示與第 1 9圖不同的光學片之亮度角度依存性的圖。 第2 1圖是表示稜鏡部的頂上帶圓的光學片之稜鏡頂 上部分的曲率半徑與正面亮度之關係的圖。 第22圖是表示光學片的柱面鏡部之接觸角度與正面 亮度之關係的圖。 第23圖是習知的稜鏡片的立體圖。 第24圖是第23圖中的XXIV — XXIV線之剖面圖。 第25圖是表示棱鏡片之亮度角度依存性的圖。 【主要元件符號說明】 1 :顯示裝置 1 0 :背光裝置 1 6 :面光源 -31 - 200831951 17 :光學片 1 8 :稜鏡層 1 9 :梯形柱狀透鏡層 21 :基材部 2 2 :棱鏡部 23 :柱面鏡部 2 4 :梯形柱狀透鏡部 2 5 :陣列透鏡層 2 1 8 :底表面BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical sheet, a backlight device, and a display device, and more particularly to an optical sheet, a backlight device, and a display device used in a backlight device. [Prior Art] In the field of display devices typified by liquid crystal displays, it is required to increase the front luminance. Therefore, the backlight of the display device uses an optical sheet that condenses light from the surface light source to the front surface to enhance the front luminance. Such an optical sheet is generally a ruthenium disclosed in Japanese Patent No. 3262230. Referring to Fig. 23 and Fig. 24, a conventional prism sheet 100 is provided with a plurality of triangular prism-shaped 稜鏡 lenses (hereinafter referred to as 稜鏡) PL which are arranged side by side on the surface. The light R100 from the surface light source is refracted on the surface of the 稜鏡PL, and is emitted toward the normal direction of the cymbal 1 ( (hereinafter referred to as the front side). In this way, the cymbal 1 will collimated the diffused light to the front to enhance the front brightness of the display. Recently, the front brightness has been increased, and a technique with a higher frontal brightness than the conventional film has been proposed. In Japanese Laid-Open Patent Publication No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. Since the brightness filter set is overlapped by two cymbals, the front brightness is higher than that of a cymbal. Further, it is considered that since the brightness filter group is adjusted, the direction in which the ridges are arranged side by side intersects each other, and the ridges are overlapped, so that the two axes can be adjusted (for example, the up and down direction of the display screen and the left -4- 200831951 Right angle) brightness angle dependence. However, if the two pieces are overlapped, the manufacturing process becomes cumbersome. Further, in the conventional cymbal film, in terms of the luminance angle distribution, not only the peak of the luminance is generated on the front side, but also the peak of the luminance (the si delobe) is generated at the wide angle. The solid line in Fig. 25 indicates the brightness angle dependence (brightness angle distribution) of the lower viewing angle of the prisms arranged at the apex angle of 9 并 in the vertical direction. The horizontal axis is the angle of view (degrees), and the vertical axis is based on the front luminance (the luminance in the normal direction of the light diffusion plate) in the case where only the light diffusion plate is laid on the surface light source (1. Relative brightness of 0) (a. u· ). Referring to Fig. 25, in the conventional cymbal, the first peak is expressed in the range of ±30 degrees of the upper and lower viewing angles, but at the same time, the viewing angle is +50 degrees or more and the viewing angle is -50 degrees or less. The range of viewing angles represents the 2nd peak (so-called side lobes). In the case where the angle of view is the peak, and the natural brightness angle dependence of the brightness and the angle of view is gradually decreased while slowly decreasing, the angle of viewing by the user who views the display screen does not feel uncomfortable, but appears as the first In the case of the brightness angle dependence of the side lobes of the picture, the user who views the display screen feels uncomfortable. Therefore, it is preferable to suppress the generation of side lobes. [Patent Document 1] Japanese Patent No. 3 2 2 2 2 3 0 [Patent Document 2] Japanese Patent Application Laid-Open No. Hei 10-506500 (Invention) The object of the present invention is to provide an available An optical sheet that further enhances the front brightness and adjusts the two-axis brightness angle dependence. Another object of the present invention is to provide an optical sheet which can suppress the generation of side lobes. [Means for Solving the Problems and Effects of the Invention] The optical sheet of the present invention is used for a backlight. The optical sheet system includes a sheet-shaped base material portion, a plurality of first lenticular lens portions, and a plurality of second lenticular lens portions. The plurality of first lenticular lens portions are arranged side by side on the first surface of the base material portion. The plurality of second lenticular lens portions are arranged on the second surface opposite to the first surface of the base portion, and are arranged side by side so as to intersect the first lenticular lens portion, and each of the cross-sectional shapes has a width along the direction A ladder shape in which the base material portion side is widened. According to the optical sheet of the present invention, the light ray incident on the second lenticular lens from the outside is condensed by the second lenticular lens portion toward the normal direction of the base portion, and the first lenticular lens portion is further directed toward the substrate. The direction of the normal line is concentrated. Therefore, the use of one piece can further enhance the front brightness. Further, the first lenticular lens portion and the second lenticular lens portion intersect each other. Therefore, the brightness dependence of the two axial directions can be adjusted. Preferably, the first lenticular lens portion is orthogonal to the second lenticular lens portion. At this time, the optical lens sheet can adjust the axial direction orthogonal to each other, for example, the brightness angle dependence of the horizontal direction and the vertical direction. Preferably, the angle between the side surface of the second lenticular lens portion and the second surface is greater than 70 degrees and less than 90 degrees. At this time, the condensing of the second lenticular lens portion is further enhanced. Therefore, you can increase the front brightness by stepping into -6-200831951. Also, generation of side lobes can be suppressed. It is preferable that the optical sheet has a gap between the adjacent second lenticular lens portions. At this time, the condensing effect of the second lenticular lens portion is further enhanced. Therefore, the front brightness can be further improved. Preferably, the cross-sectional shape of the first lenticular lens portion is a triangle. More preferably, the cross-sectional shape of the first lenticular lens portion is an isosceles triangle having an obtuse angle. More preferably, the apex angle is 100 degrees or more and 120 degrees or less. At this time, generation of side lobes can be suppressed. Preferably, the cross-sectional shape of the first lenticular lens portion is an isosceles triangle having a rounded upper portion, and the upper portion is an arc having a radius of curvature less than 20% of the bottom edge. At this time, generation of side lobes can be suppressed. Moreover, since the top portion is rounded, the top portion is less likely to be defective or deformed. Preferably, the first lenticular lens 邰 is a cylindrical mirror (Cylindrical Lenses). At this time, generation of side lobes can be suppressed. It is desirable that the contact angle between the convex surface of the cylindrical mirror portion and the surface including the edge of the cylindrical mirror portion is greater than 45 degrees and less than 90 degrees. More preferably, the contact angle is 50 degrees or more and 70 degrees or less. At this time, the concentrating effect can be further enhanced. The backlight device of the present invention includes a surface light source and the above-described optical sheet. Further, the display device of the present invention includes the above-described backlight device -7-200831951. [Embodiment] [Best Mode for Carrying Out the Invention] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the same or equivalent parts in the drawings, the same symbols are attached, and the description thereof is not repeated. [Display Device] Referring to FIGS. 1 and 2, the display device 1 includes a backlight device 1 and a liquid crystal panel 20 laid on the front surface of the backlight device 1 . The liquid crystal panel 20 has a plurality of pixels arranged in a matrix. The display screen of the display device 1 has a rectangular shape in which the left and right directions (X direction in the drawing) are long sides, and the vertical direction (y direction in the drawing) is a short side. [Backlight device] The backlight device 1 is a so-called direct type, and includes a surface light source 16 that emits diffused light, and an optical sheet 17 that is laid on the surface light source 16. The surface light source 16 includes a casing 1 1 , a plurality of fluorescent tubes 12 , and a light diffusing plate 13 . The outer casing 11 is a casing having an opening 1 1 正面 on the front surface, and houses the fluorescent tube 1 2 therein. The inner side surface of the outer casing 11 is covered with a reflection filter Π 1 . The reflection filter 11 1 is for diffusing reflection of light emitted from the fluorescent tube 12, and directs the diffused light to the opening portion 1 1 〇. The reflection filter 1 1 1 is, for example, RUMIRER (registered trademark) E60L or E60V manufactured by Toray Industries, Inc., and has a diffuse reflectance of 95 or more. The plurality of fluorescent tubes 12 are arranged side by side in the vertical direction (y direction -8 - 200831951 in Fig. 1) in front of the back surface of the casing 11. The fluorescent tube 12 is a line light source such as a cold cathode tube which is extended in the left-right direction (X direction in Fig. 1). Further, instead of the fluorescent tube 12, a plurality of point light sources such as LEDs (Light E m i 11 i n g D e v i c e ) may be housed in the casing 11. In addition, a line light source and a point light source can be housed. The light diffusing plate 13 is fitted into the opening 1 1 〇 and arranged in parallel with the back surface of the casing 1 1 . When the light diffusing plate 1 3 is fitted into the opening portion 1 1 0, the inside of the outer casing 1 1 is sealed. Therefore, it is possible to prevent the light emitted from the fluorescent tube 12 from leaking out of the outer casing 1 from the light diffusing plate 13 and to enhance the light. The light diffusing plate 13 will illuminate the light from the fluorescent tube 12. And the light reflected by the reflection filter 111 is emitted to the front surface with a substantially uniform diffusion. The light diffusing plate 13 is composed of a transparent substrate and a plurality of particles dispersed in the substrate. The particles dispersed in the substrate are different in refractive index from the substrate for light having a wavelength in the visible light range. Therefore, the light diffusing plate 13 is used to diffuse the incident light, and the diffused light penetrates the light diffusing plate 13. The base material of the light diffusing plate 13 is, for example, glass, a polyester resin, a polycarbonate resin, a polyacrylate resin, an alicyclic polyolefin resin, a polyphenylene resin, a halogen resin, and a polychlorinated resin. A resin such as a vinyl resin, a polyvinyl acetate resin, a poly-t-sulfonate resin, or a triacetate nitrocellulose resin. Although the surface of the light diffusing plate 13 shown in Fig. 2 is a flat surface, it may not be a flat surface, and a concave portion for generating a diffusion effect may be formed. [Optical Sheet; | -9- 200831951 Referring to Figures 3 to 5, the optical sheet 17 is in the form of a sheet or a film. The optical sheet 17 includes a base portion 21, a tantalum layer 18 formed on one surface 2 1 3 of the base portion 21, and a surface 2 1 4 formed on the other side of the base portion 2 1 The trapezoidal cylindrical lens layer 19 on the top. The optical sheet 17 is a trapezoidal columnar lens layer 19 opposed to the surface light source 16 and the tantalum layer 18 is placed on the surface light source 16 so as to face the liquid crystal panel 20. The base portion 2 1 is in the form of a sheet or a film, and is transparent to the wavelength of the visible light range. The base material portion 21 is, for example, glass, a polyester resin, a polycarbonate resin, a polyacrylate resin, an alicyclic polyolefin resin, a polystyrene resin, a polyvinyl chloride resin, or a polyacetic acid. A resin such as a vinyl ester resin, a polybutene sulfonate resin, or a triacetate nitrocellulose resin. The enamel layer 18 includes a sheet-shaped sub-base portion 2 1 1 formed on the surface 21 1 and a plurality of 稜鏡 lens portions (hereinafter referred to as 稜鏡 portions) 22 formed on the sub-base portion 2 1 1 . In short, the crotch portion 22 is formed on the side of the face 213. Each of the jaws 2 2 is a columnar lens extending in the left-right direction (X direction in the drawing), and has a triangular cross section. A plurality of crotch portions 22 are arranged side by side in the vertical direction (y direction in the drawing). In short, each of the jaws 22 is an extension that is slightly perpendicular to the direction of the juxtaposition. The crotch portion 22 condenses the light incident from the base portion 21 to the front surface (the normal direction of the base portion 21) and emits the light. At this time, since the crotch portion 22 is arranged in the vertical direction, the brightness angle dependency in the vertical direction is mainly adjusted to increase the front brightness. The plurality of dam portions 22 are integrally formed with the sub-base portion 2 1 1 , and these -10- 200831951 are formed of the same resin. Specifically, the plurality of crotch portions 22 and the sub-base portion 2 1 1 are made of ionizing radiation-curing resin. Here, the 'ionizing radiation-curable resin is a resin that is hardened by ionizing radiation when ultraviolet rays or electron beams are used, and examples thereof include polyester-based acrylic resin, polyurethane-based acrylic resin, polyether-based acrylic resin, epoxy-based acrylic resin, and polyester. A methacrylic resin, a polyurethane methacrylic resin, a polyether methacrylic resin, or an epoxy methacrylic resin. The trapezoidal cylindrical lens layer 19 includes a sheet-like sub-base portion 2 1 2 formed on the surface 2 1 4 and a plurality of trapezoidal cylindrical lens portions 24 formed on the sub-base portion 2 1 2 . The trapezoidal cylindrical lens portion 24 has a columnar shape extending in the vertical direction (y direction in the first drawing), and has a cross-sectional shape of a trapezoid whose width is enlarged along the facing surface 214. In short, as shown in Fig. 5, the width W 2 of the bottom surface 2 18 of the cross-sectional shape of the trapezoidal cylindrical lens portion 24 is shorter than the width W3 between the two edges ED of the trapezoidal cylindrical lens portion 24. The trapezoidal cylindrical lens portions 24 are arranged side by side in the left-right direction (the X direction in Fig. 1). In short, the trapezoidal cylindrical lens portion 24 is orthogonal to the crotch portion 22. In other words, the direction in which the trapezoidal lenticular lens portions 24 are arranged is orthogonal to the direction in which the dam portions 22 are arranged. The trapezoidal cylindrical lens portion 24 condenses the diffused light from the surface light source 16 to the front direction to enhance the front luminance. At this time, since the crotch portions 24 are arranged in the left-right direction, the brightness angle dependence in the left-right direction is mainly adjusted to increase the front brightness. In the third to fifth figures, the gaps 2 15 are provided between the adjacent trapezoidal cylindrical lens portions 24, but the adjacent trapezoidal cylindrical lens portions 24 can be in contact with each other -11 - 200831951. In short, the adjacent trapezoidal cylindrical lens portions 25 are in contact with each other, and there is no gap 2 15 . However, as will be described later, the front surface brightness can be increased by the gap 2 15 . Therefore, it is preferable that the gap 2 1 5 is a trapezoidal cylindrical lens portion 24 and the sub-base portion 2 12 is formed by using the same ionizing radiation hardening resin. Composition. In the optical sheet 17, the crotch portion 22 condenses the diffused light in the vertical direction from the diffused light from the surface light source, and the trapezoidal column portion 24 condenses the light in the left and right direction from the diffused light from the surface light source 16. Light. Therefore, by the concentrating function of the prism portion 22 and the Synergy function of the condensing function of the lenticular portion 24, the front luminance of the sheet 17 is higher than that of the conventional cymbal, which is arranged side by side. The crotch portion 22 in the up-and-down direction is a trapezoidal mirror portion 24 that condenses the up-and-down diffused light and is arranged side by side in the left-right direction. The diffracted rays in the left-right direction are collected, so that the two axial directions (the vertical direction and the horizontal direction) Further, depending on the brightness angle dependency, the condensing effect of the trapezoidal cylindrical lens portion 24 and the condensing effect of the mirror portion 22 can suppress the change in brightness depending on the viewing angle of the right and left angle dependence. Therefore, the brightness angle distribution to the right and left corners is wider than the angle of view in the up and down direction (in short, the left and right viewing angles are wider than the upper and lower viewing angles). When the user views the display screen of the display device 1, the chance of viewing from the viewing direction is greater than the chance of viewing from the upper and lower sides. Therefore, if the angle of view of the direction changes, if the degree of change is too large, the user who views the display screen from the left or the right may feel uncomfortable. The reason is that the S-edge ED is set to the 〇 body, and the 16-lens lens diffuses the trapezoidal column optical slice. The columnar transparency of the direction can be suppressed. The 〇 is smaller than the rim. The direction of the distribution is also left and right. Oblique to the left and right. As long as -12-200831951 slightly changes the viewing angle, the brightness will change sharply. When the optical sheet 17 is used, since the change in brightness with respect to the left and right viewing angles can be suppressed, the user is less likely to feel uncomfortable, and the brightness angle dependency applied to the display device can be realized. The cross-sectional shape of the crotch portion 22 is preferably an angular shape, and the apex angle 0 40 is preferably an obtuse angle. When the apex angle is 90 degrees, the angular distribution of the brightness produces significant side lobes. When the apex angle 0 40 of the crotch portion 22 is an obtuse angle, the side lobes are suppressed. In order to suppress the side lobes and enhance the front brightness, the apex angle is preferably 100 to 120 degrees. 〇 In order to suppress the side lobes, a circle may be formed on the top of the dam portion 22. In general, among the cross-sectional shapes of the crotch portion 22, the top portion may have a curvature. At this time, the side lobes are suppressed as much as possible, and the top of the dome can be suppressed. It is preferable that the cross-sectional shape of the top is an arc, and it is more preferable that the arc-shaped trapezoidal cylindrical lens portion 24 having a radius of curvature of 20% of the length W4 of the bottom surface of the cross-sectional shape of the crotch portion 22 is The diffused light in the left and right direction is concentrated to help increase the front brightness. By the trapezoidal lenticular lens portion 24, even if the apex angle 404 of the dam portion 22 is an obtuse angle, a high front luminance can be obtained. FIGS. 6 and 7 show the trapezoidal cylindrical lens portion 24 of the optical sheet 17. A diagram of the relationship between shape and front brightness. The horizontal axes of Figs. 6 and 7 are angles 0 10 of the side surface 24 1 of the trapezoidal cylindrical lens portion 24 and the surface 216 including the both edges ED of the trapezoidal cylindrical lens portion 24. Further, the vertical axis is based on the front luminance of the cymbal having a apex angle of 90 degrees (-13-200831951 =1. 0) The front luminance ratio of the optical sheet 17 . Further, the apex angle 404 of the crotch portion 22 of the optical sheet used for investigation was formed at 10 degrees. In Fig. 6, the ratio (W1/W2) of the width W2 of the bottom surface 218 of the trapezoidal cylindrical lens portion 24 with respect to the width W1 of the gap 215 between the adjacent trapezoidal cylindrical lens portions 24 is 1. 0 is formed, and the widths W1 値 and W 3値 are predetermined, and the angle 0 1 改变 is changed. In short, the widths W1 and W3 are predetermined, and the height T0 of the trapezoidal cylindrical lens portion 24 is changed, and the angle 0 10 is changed. On the other hand, in Figure 7, W1/W2 is 1. The formation of 0 is predetermined, and the height T 0 of the trapezoidal cylindrical lens portion 24 is also predetermined, and the angle θ 1 〇 is changed. In summary, the height T0 is predetermined, and the widths W1 値 and W2 改变 are changed, thereby changing the angle Θ 1 0 . Referring to Fig. 6 and Fig. 7, when the angle 010 is 90 degrees or less, although the sixth and seventh figures have a positive front luminance ratio (Fig. 6), or the front luminance ratio does not follow the angle 0 10 It rises and falls (Fig. 7), but if the angle 010 exceeds 70 degrees, the front brightness ratio will rise sharply. Further, when the angle Θ10 is larger than 70 degrees, the side lobes of the angular distribution of the left and right viewing angles are significantly suppressed more than the conventional cymbals. From the above, the angle (910 is greater than 70 degrees, the front brightness is higher than that of the optical sheet forming only the prism layer 18. Further, if the angle is 72 degrees or more, even if the apex angle of the crotch portion 22 is an obtuse angle, the ratio can be obtained. The apex angle of 90 degrees is higher in frontal brightness, and it can also suppress side lobes in the up and down direction and the left and right direction. More preferably, the angle Θ10 is 72. 5 degrees or more, less than 90 degrees. At this time, a higher front brightness can be obtained. -14- 200831951 Although the adjacent trapezoidal cylindrical lens portions 24 can achieve the above effects even if they are in contact with each other, as shown in Figs. 3 to 5, gaps are provided between adjacent trapezoidal cylindrical lens portions 24. 2 1 5, the front brightness will be improved. Fig. 8 is a view showing the relationship between the width of the gap 215 and the front luminance. The horizontal axis of Fig. 8 indicates Wl/W2. Further, the vertical axis is the same as that of Figs. 6 and 7, and shows the front luminance ratio. The angle 010 of the optical sheet 17 used for investigation is 80 degrees, and the apex angle 040 of the crotch portion 22 is 11 degrees. Referring to Fig. 8, the front luminance ratio W1/W2 is larger and higher from 0, Wl / W2 = 0. 7, indicating the peak. On the other hand, it is greater than W1 / W2 = 0. 7, the front brightness will slowly drop. However, if there is no gap 215 (Wl/W2 = 0), the front brightness will be greater than 1. From the above, in order to improve the front brightness, it is preferable to set the gap 2 1 5 . If the peak area of the front luminance ratio of Fig. 8 is considered, it is better that W 1 / W2 is 〇. 1 or more and 4 or less. [Other Forms of Optical Sheet] As shown in Figs. 9 to 11 , the optical sheet 17 may be provided with an Lenticular Lens layer 25 instead of the ruthenium layer 18 on the surface 213 of the base portion 21. The array lens layer 25 includes a sub-base portion 2 1 1 and a plurality of cylindrical mirror portions 23 arranged side by side in the vertical direction. The sub-base portion 2 1 1 and the cylindrical mirror portion 23 are integrally formed, and the material is an ionizing radiation-curable resin. The cylindrical mirror portion 2 3 condenses the light incident from the base portion 21 to the front surface and emits the outside. -15- 200831951 In summary, the cylindrical mirror portion 23 has a condensing function. The cylindrical mirror portion 23 of Fig. 10 has an arcuate shape in cross section. Specifically, the top portion of the cylindrical mirror portion 23 is an arc, and the portion from the top portion to the edge (the portion near the edge) is a straight line corresponding to the line connecting the arc points of the top portion. The cross-sectional shape of the cylindrical mirror portion 23 may be an arc shape as shown in Fig. 10, or may be an arc or an elliptical arc. Further, in the first drawing, the adjacent trapezoidal cylindrical lens portions 23 are in contact with each other, but a gap may be provided between the adjacent trapezoidal cylindrical lens portions 23. The array lens layer 2 5 is the same as the germanium layer 18, and condenses the diffused light in the up and down direction to enhance the front brightness. Therefore, the optical sheet 17 having the array lens layer instead of the enamel layer 18 has the same effect as the film 17 having the enamel layer 18. Further, since the cylindrical mirror portion 23 is a convex surface 23 having a curvature on the surface, the side lobes can be more suppressed than the crotch portion 22. In the cylindrical mirror portion 23, the degree (hereinafter referred to as the contact angle) 0 20 of the surface including the edge ED (in general, the upper surface of the base portion 211) and the convex portion 23 0 of the cylindrical mirror portion 23 is larger. The concentrating effect is higher. The optimum contact angle 0 20 of the prism portion 23 is 45 degrees or more and less than 90 degrees. More preferably, the contact angle 0 20 is 50 degrees or more and 70 degrees or less. In the above-described embodiment, the direction in which the trapezoidal cylindrical lens portion 24 is aligned is orthogonal to the direction in which the crotch portion 22 and the cylindrical mirror portion 23 are arranged. However, it is necessary to be strictly orthogonal, and it is possible to achieve the present invention by crossing. The effect of the process, in short, can adjust the brightness angle dependence of the up and down direction and the left and right direction to increase the degree of front brightness. The upper surface of the upper ED is provided with a sub-corner surface of the optical tool - 16-200831951, and the 'ankle portion 2 2 and the cylindrical mirror portion 2 3, and the sub-substrate portions 21 1 and 2 1 2, and the trapezoidal column The lens portion 24 can be formed of the same material as the base portion 2A. Further, in place of the ionizing radiation-curable resin, a thermosetting resin or a thermoplastic resin can be used. It is also possible to have no sub-base portions 2 1 1 and 2 1 2 . In short, the crotch portion 22 or the cylindrical mirror portion 23 and the trapezoidal cylindrical lens portion 24 may be directly formed in the base portion 2 1 . Also, the surface of the substrate can be shaped. Although the adjacent trapezoidal cylindrical lens portions 22 are in contact with each other, a gap may be provided between the adjacent trapezoidal cylindrical lens portions 22. The cross-sectional shape of the trapezoidal cylindrical lens portion 24 may not be a strict trapezoid. For example, in the trapezoidal cylindrical lens portion 24, the bottom surface 218 may not be in strict parallel with the surface 216 including the two edges ED. Further, although the bottom surface 2 18 of the figure is actually a flat surface, it may have a slight unevenness. Although the backlight device 10 shown in Figs. 1 and 2 is of a direct type, the optical sheet 17 may be used in an edge light backlight device. [Manufacturing Method] A manufacturing method using a roll-to-roll method will be described as an example of the manufacturing method of the optical sheet 17 described above. Hereinafter, a method of manufacturing the optical sheet 17 having the enamel layer 18 will be described, but the optical sheet 17 having the array lens layer 25 can be manufactured in the same manner. In the roll-to-roll method, a trapezoidal cylindrical lens layer 1 9 is formed on the base portion 2 1 (first process), and then a base layer 17 - 200831951 1 8 is formed on the base portion 21 (2nd) Process). First, explain the first process. Preparation: a cylindrical first roll in which a base film of the base portion 21 is wound around the surface in the circumferential direction, and a cylindrical second roll for winding a base film formed of the trapezoidal cylindrical lens layer 19. A roll for use in a cylindrical trapezoidal cylindrical lens for forming a trapezoidal cylindrical lens layer 19. The rolling plate for a trapezoidal cylindrical lens is a transfer groove having a trapezoidal cylindrical lens portion 24 on its surface. Each of the transfer grooves extends in the axial direction of the stencil and is arranged in the circumferential direction. The cross-sectional shape of the transfer groove corresponds to the cross-sectional shape of the trapezoidal cylindrical lens portion 24. The first roller, the trapezoidal cylindrical mirror, and the second roller are disposed in parallel with each other in the axial direction. After the arrangement, the radiation hardening resin is charged in the transfer groove of the rolling plate for a trapezoidal cylindrical lens. After the filling, the first roller was twisted to feed the base film, and the base film was conveyed from the first roller toward the trapezoidal cylindrical lens. Then, the trapezoidal cylindrical lens is rotated by a roll, and the ionizing radiation-curable resin which is filled in the transfer groove is transferred onto the base film which has been transported. At this time, the base roller is sandwiched between the backup roller and the trapezoidal cylindrical lens which are arranged to face the trapezoidal cylindrical lens, and the ionizing radiation-curable resin is transferred onto the base film. The transferred ionizing radiation-curing resin is hardened by irradiation with ionizing radiation, and a trapezoidal cylindrical lens layer is formed on the base film 19°. A base film (hereinafter referred to as an intermediate film) having a trapezoidal cylindrical lens layer 19 formed thereon is rolled. Winding around the second roller, the first process is completed. At this time, -18-200831951 trapezoidal cylindrical lens portion 24 is arranged in the circumferential direction of the second roller. After the end of the first process, the second process is started. In the second process, a second roll, a cylindrical roll for forming the tantalum layer 18, and a third roll for winding the manufactured optical sheet 17 are prepared. The use of the rolling plate has a plurality of grooves for transfer on the surface (hereinafter referred to as grooves for transfer). The cross-sectional shape of the transfer groove is the cross-sectional shape of the corresponding dam portion 22. Each of the transfer grooves extends in the circumferential direction of the rolling stencil and is arranged in the axial direction. In the same manner as in the first process, the transfer groove is charged and the resin is hardened from the radiation. Next, the second roller is turned to form a film in the middle of the transfer of the prism. At this time, among the intermediate-formed films, the intermediate-formed film is conveyed so as to contact the surface of the stencil with the surface 2 1 4 on the side opposite to the surface 2 1 3 on which the trapezoidal cylindrical lens layer 19 is formed. The intermediate film formed by the second roller is pressed against the surface of the stencil by the backup roller, and the film is formed between the backup roller and the squeegee, and the film is transferred to the transfer groove. The ionizing radiation hardening resin of the groove is transferred to the intermediate generation film. At this time, although the backup roller comes into contact with the bottom surface 2 1 8 of the trapezoidal cylindrical lens portion 24, since the bottom surface 218 is substantially flat, the shape of the trapezoidal cylindrical lens portion 24 is not easily deformed by the backup roller. The ionizing radiation hardening resin is hardened by irradiation with ionizing radiation to form a layer of tantalum 18. The optical sheet 17 manufactured by the above process is wound around the third roller. In the above process, the array lens layer 25 -19-200831951 may be formed in the second process instead of forming the germanium layer 18. The method of manufacturing the array lens layer 25 is the same as the method of manufacturing the ruthenium layer 18. However, a cylindrical mirror plate having a cylindrical mirror transfer groove corresponding to the cylindrical mirror portion 23 is used instead of the prism plate. In the above-described manufacturing method, the trapezoidal cylindrical lens layer 1 is formed first, and then the tantalum layer 18 or the array lens layer 2 5 (hereinafter referred to as the tantalum layer 18 or the like) is formed, but the tantalum layer is formed. After 1 8 , a trapezoidal cylindrical lens layer 19 can also be formed. However, it is preferred to form the trapezoidal cylindrical lens layer 1 first. When the tantalum layer 18 is formed first, when the ionizing radiation hardening resin in the process of manufacturing the trapezoidal cylindrical lens layer 19 is transferred, the apex of the crotch portion 22 (or the cylindrical mirror portion 23) is deformed in contact with the backup roller. After that. Therefore, as described above, it is preferable to form the trapezoidal cylindrical lens portion 24 which is not easily deformed even when it is in contact with the backup roller. In the above-described manufacturing method, the trapezoidal cylindrical lens transfer groove is arranged in the circumferential direction. The plate and the transfer groove are arranged in the axial direction, but it is also possible to use a trapezoidal cylindrical lens transfer groove in the axial direction and a transfer groove in the circumference. The direction of the roll. In addition, if the arrangement direction of the trapezoidal lenticular lens transfer grooves is orthogonal to the arrangement direction of the ruthenium transfer grooves, the arrangement direction of the trapezoidal lenticular lens transfer grooves and the ruthenium transfer grooves There is no particular restriction. However, one of the grooves for transfer of the trapezoidal cylindrical lens and the groove for prism transfer is arranged in the circumferential direction, and the other is a roll for trapezoidal cylindrical lens arranged in the axial direction Version, the highest rate of manufacturing. Further, a thin film of -20-200831951 may be formed in the middle of the trapezoidal cylindrical lens layer 19 to be transported to the enamel rolling plate to form a ruthenium layer, and then wound into the second roller to be continuously formed. Further, when the array lens layer 25 is formed instead of the prism layer 18, the cylindrical mirror transfer grooves are preferably arranged in the axial direction, and the trapezoidal lens transfer grooves are preferably arranged in the circumferential direction. If the cylindrical mirror transfer groove is arranged in the circumferential direction, the ionizing radiation-curable resin transferred to the base film may be removed by the edge of the cylindrical mirror transfer groove. Although the method of manufacturing the optical sheet 17 has been described above, the optical sheet 17 can be manufactured by another method different from the above-described roll-to-roll method. For example, a plate-like plate may be used to form the ruthenium layer 18, the array lens layer 25, and the trapezoidal lenticular lens layer 19. Further, it may be produced by an extrusion method, a hot press method, an injection molding method or the like. [Example 1] A plurality of optical sheets of different shape sizes were produced. 7 'Investigate the brightness angle dependency (brightness angle distribution) together with a conventional tantalum sheet. The labeling method shown in Table 1 was produced by the above-described roll-to-roll method. The optical sheets of the inventive examples 1 to 5 of the shape and size. The optical sheets of Examples 1, 4 and 5 of the present invention correspond to the optical sheets shown in Figs. 3 to 5 and have a ruthenium layer. The items (W2, 0 1 0, etc.) of the inventive examples 1, 4 and 5 in Table 1 correspond to the symbols in the third to fifth figures. On the other hand, the inventive examples 2 and 3' correspond to the optical sheets shown in Figs. 9 to 1 and have an array lens layer. The items in the examples 2 and 3 of the present invention in Table 1 correspond to the symbols in the drawings 9 to 11. -21 _ 200831951 in § § 00 ^Τ) (Ν ο r-H 17. 5 I 1 1 should be 瞧 1. 16 Invention Example 4 〇 78. 8 12. 5 〇 (Ν Ο r-Η τ-Η 16. 4 1 I 1 1 τ-Η r-H Inventive Example 3 〇 78. 7 12. 5 〇 (Ν 1 I 1 1 卜 〇 23. 7 Ό Τ*Η τ-Η (N 孽 〇 § inch 〇 tn (Ν 1 1 1 I § 23. 3 1. 16 鹬 Comparative example 1 1 1 1 1 1 1 1 1 1 1 Η r-H 〇 g 〇 〇 (Ν ο Η 17. 5 1st 1 1 1 IT) 粼(//m) £ (Urn) (urn) (//m) (degrees) (//m) (//m) (//m) (μπι) (degrees) (//m) (//m) Item bottom surface width W2 Angle 010 Height το Gap width W1 Pitch vault angle 0 40 Height τι Top curvature radius P1 Top curvature radius R0 Contact angle 0 20 Height T2 Pitch P2 Front brightness The ratio of the trapezoidal cylindrical lens portion to the cylindrical mirror portion -22-200831951 Referring to Table 1, the cross-sectional shape of the crotch portion of the first, fourth, and fifth embodiments of the present invention is an isosceles triangle. However, in Inventive Example 4, the top of the crotch is rounded, and the radius of curvature of the top portion of the circle is 5 / z m. The cylindrical mirror portion of the second embodiment of the present invention has an arcuate cross-sectional shape, and the cross-sectional shape of the cylindrical mirror portion is a straight line in the vicinity of the edge. On the other hand, the cross-sectional shape of the cylindrical mirror portion of the third embodiment of the present invention is an elliptical arc having the end point of the long axis as a vertex. In the optical sheets of Inventive Examples 1 to 5, the base material portion was a polyethylene terephthalate (PET) film having a thickness of 250. Further, in the prism layer, the array lens layer, and the trapezoidal columnar lens layer, an acrylic ultraviolet curable resin using an ultraviolet curable resin is cured by irradiation with ultraviolet rays. The ruthenium of the comparative example was produced by the following method. On the PET film having a thickness of 250 // m, an acrylic ultraviolet curable resin was uniformly applied by a coating method to form an ultraviolet curable resin layer having a thickness of 30 // m. Then, the ruthenium sheet of the shape shown in Figs. 23 and 24 was produced by pressing the squeegee against the ultraviolet curable resin layer and irradiating the ultraviolet ray. As shown in Table 1, the distance between the ridges of the cymbals is 50 // m and the apex angle is 90 degrees. [Investigation of Luminance Angle Distribution] The luminance angle dependence (brightness angle distribution) of the optical sheets of the inventive examples 1 to 5 and the prisms of the comparative examples were examined. The cold cathode tube was housed, and a reflective film was placed on the inner surface, and an outer casing of the light diffusion plate was fitted to the opening, and the optical sheet of the first embodiment of the present invention was laid. At this time, the optical sheet was laid in such a manner that the trapezoidal cylindrical lens surface -23-200831951 was applied to the light diffusing plate of the outer casing. The direction in which the trapezoidal cylindrical lens portions are arranged is the left-right direction, and the direction in which the crotch portions are arranged is the vertical direction. 铺设 After the optical sheets of the first embodiment of the present invention are laid on the outer casing, the brightness angle distribution is examined. The viewing angle is the 0-degree axis in the normal direction (front) of the optical sheet, the vertical angle from the 0-degree axis to the up-and-down direction, and the left-right angle from the 0-degree axis to the left-right direction. The brightness of each of the upper and lower viewing angles and the left and right viewing angles is measured by a luminance meter. The measurement of the brightness is at the center of the surface of the optical sheet. Similarly to the optical sheets of Inventive Example 1, the optical sheets of the other inventive examples 2 to 5 were also examined for the luminance angle distribution. On the other hand, the ruthenium of the comparative example was laid on the outer casing, and the angular distribution of the brightness was investigated. At this time, the casing is laid in such a manner that the direction in which the turns are arranged in the vertical direction. Fig. 12 is a view showing the luminance angle distribution of the optical sheet of Example 1 of the present invention, and Fig. 13 is a view showing the luminance angle distribution of the optical sheet of Example 2 of the present invention, and Fig. 14 is a view showing the brightness of the optical sheet of Example 3 of the present invention. The angular distribution is shown in Fig. 15 as the luminance angle distribution of the fourth embodiment of the present invention, and the luminance angle distribution of the fifth example of the present invention is shown in Fig. 16. Further, the luminance angle distribution of the cymbal sheet of the comparative example is shown in Fig. 25. The horizontal axis of Fig. 12 to Fig. 16 and Fig. 25 is the angle of view (degree), and the vertical axis is based on the front luminance of the light diffusing plate of the outer casing (the brightness in the normal direction of the light diffusing plate) (1·0). Relative brightness (a. u. ). Further, the solid line in the figure is the luminance angle distribution of the upper and lower viewing angles, and the broken line in the figure is the luminance angular distribution of the left and right viewing angles. Table 1 indicates the relative luminance (front luminance) X1 of the viewing angles obtained by the respective luminance angular distributions of Examples 1 to 5 of the present invention, and the front luminance X2 obtained from the luminance angular distribution of the comparative example. Ratio (X1/X2: hereinafter referred to as front luminance ratio). Referring to Fig. 12 to Fig. 16, Fig. 25 and Table 1, the front side luminance of the optical sheets of Examples 1 to 5 of the present invention was higher than that of the prism sheet of the comparative example, and the front luminance ratio was 1. 11~1. 16. Further, in the first to fifth embodiments of the present invention, the side lobes of the upper and lower viewing angles (the luminance peaks generated at the wide angle) were small, and the side lobes were suppressed to be lower than the comparative examples. Further, in the luminance angle distributions of the first to fifth embodiments of the present invention, the left and right viewing angles are slower than the upper and lower viewing angles with respect to the brightness having a wide viewing angle, and the left and right viewing angles are natural alignment distributions. In other words, the difference between the maximum relative luminance 値 (peak 値) and the minimum relative luminance 之中 in the luminance angular distribution is that the left and right viewing angles are smaller than the upper and lower viewing angles, and the luminance angular distribution of the left and right viewing angles is wider than the upper and lower viewing angles. Further, in the inventive examples 2 and 3 having the cylindrical mirror layer, the vertical viewing angle is also slow with respect to the brightness having a wide viewing angle, not only the left and right viewing angles, but also the natural alignment distribution of the upper and lower viewing angles. [Embodiment 2] In the trapezoidal cylindrical lens layer of the optical sheet, the change in the front luminance of the gap width W1 between the adjacent trapezoidal cylindrical lenses was examined. Among the optical sheets having a prism layer, a plurality of optical sheets having various gap widths W 1 are fabricated. The other shape of the optical sheet other than the gap width w1 is the same as that of the optical sheets of the first and second embodiments of the present invention. The front side luminance was determined for the manufactured optical sheet, and the ratio of the front luminance (front luminance ratio) of the film of Example-25-200831951 to the comparative example was obtained. Fig. 8 shows the results of the investigation. The horizontal axis is w 1 / W2 and the vertical axis is the positive brightness ratio. Referring to Fig. 8, in all areas where W1 / W2 is changed, the front luminance ratio is greater than 1. 0. Furthermore, the front luminance ratio W1/W2 is larger and higher from 0, and W1 / W2 = 0. 7, indicating the peak, 0. After 7 is slowly falling. [Example 3] Among the trapezoidal cylindrical lens layers of the optical sheet, the change in the front luminance with respect to the change in the angle 0 1 0 was examined. First, the ratio of the gap width W 1 to the bottom surface W2 (W1/W2) is 1. 0 is formed, and the widths W1 and W2 are predetermined, and a plurality of optical sheets having an angle of change of 0 10 are produced. Specifically, the heights T 0 of the trapezoidal cylindrical lens portions are different from each other, thereby fabricating a plurality of optical sheets having different angles of 0 10 . The shape and size of the trapezoidal cylindrical lens layer other than the height T0 and the angle 0 10 and the shape and size of the prism layer are the same as those of the first and second embodiments of the present invention. Hereinafter, these optical sheets are referred to as highly variable optical sheets. On the other hand, the manufacturing W1/W2 is 1. 0 is formed, and the height T0 of the trapezoidal cylindrical lens 邰 24 is also predetermined, and a plurality of optical sheets having an angle of 0 1 改变 are changed. Specifically, the widths W1 and W2 are different, whereby a plurality of optical sheets having different angles 0 10 are manufactured. The shape and dimensions of the trapezoidal lenticular lens layer other than the widths Wi, W2 and angle Θ 10 and the shape of the prism layer are in accordance with the first and second embodiments of the present invention. Hereinafter, these optical sheets are referred to as highly fixed optical sheets. -26 - 200831951 For the manufactured highly variable optical sheets and highly fixed optical sheets, the front luminance was obtained, and the ratio of the front luminance of the first embodiment to the comparative example (front luminance ratio) was obtained. The results of the survey are shown in Figures 6 and 7. Fig. 6 is a front luminance ratio obtained by highly variable optical sheets, and Fig. 7 is a front luminance ratio obtained by fixing optical sheets at a high height. In Fig. 6 and Fig. 7, the horizontal axis is the angle Θ 1 0 (degrees), and the vertical axis is the front luminance ratio. Although the angle 010 is less than 70 degrees, the front luminance ratio is independent of the increase of the angle 010, which is approximately the same (Fig. 6), or decreases with the increase of the angle 010 (Fig. 7), but the angle is 0 1 0. If it is 70 degrees or more, the front brightness ratio will rise sharply. Further, as a result of investigating the angular distribution of the brightness of each of the optical sheets, when the angle 0 1 〇 is 70 degrees or more, the side lobes of the upper and lower viewing angles which are suppressed by the side lobes of the left and right viewing angles are low. On the other hand, when the angle 010 is less than 70 degrees, the degree of side lobes of the left and right viewing angles is the same as that of the conventional cymbal. Fig. 17 shows a luminance angle distribution of the height-variation optical sheet having an angle 010 of 60 degrees, and is an example. [Embodiment 4] Among the enamel layers of the optical sheet, the relationship between the apex angle 0 40 of the prism portion and the front luminance ratio and the side lobes was examined. A plurality of optical sheets having different apex angles are produced. Among the size shapes of the enamel layer of the optical sheet, the pitch is fixed, the height is changed, and the apex angle is changed. Specifically, the optical heights τ 1 and the apex angles 0 4 0 are different, and other optical sheets having the same shape and size as the crotch portion of the inventive example 1 -27-200831951 are used. Further, the shape and dimensions of the trapezoidal cylindrical lens layer and the base portion of each optical sheet were the same as in the inventive examples 3 and 4, and the front luminance was obtained for the plurality of optical sheets that were produced, and Example 1 was obtained. The ratio of the front luminance to the comparative example (front luminance ratio). Further, the luminance angle distribution was examined for each optical sheet, and the presence or absence of side lobes was confirmed. Yu Di 18 chart does not check the results. The horizontal axis of the figure 18 is the vertex angle 〇 (degrees), and the vertical axis is the front luminance ratio. As shown in Fig. 18, the front luminance is as small as the apex angle 404. However, the smaller the apex angle, the more pronounced the side lobes are. Fig. 19 shows the luminance angular distribution of the optical sheet having the apex angle Θ40 of 90 degrees, and Fig. 20 shows the luminance angle distribution of the optical sheet having the apex angle 040 of 100 degrees. Referring to Figs. 19 and 20, in the optical sheet (Fig. 19) in which the apex angle 040 is 90 degrees, the degree of side lobes generated for the upper and lower viewing angles is the same as that of the cymbal of the comparative example, at the vertex angle of 40. In the 100-degree optical sheet (Fig. 20), side lobes of the upper and lower viewing angles can be suppressed. [Embodiment 5] The change in the front luminance with respect to the change in the radius of curvature of the optical sheet having a constant radius of curvature with respect to the top portion of the crotch portion was investigated. The apex angle 0 40 and the pitch P 1 of the crucible portion were the same as those of the prism portion of the fourth embodiment of the present invention, and a plurality of optical sheets having different radii of curvature at the top portion were formed. Further, the shape and size of the trapezoidal cylindrical lens portion and the base portion of each optical sheet are the same as those of the inventive examples 3 and 4. For the manufactured optical sheet, the front luminance was obtained, and the ratio of the front luminance of Example -28 - 200831951 1 with respect to the ruthenium of the comparative example was obtained (the front side is brighter than the second graph, the investigation result is shown. The horizontal axis in the figure is the ratio of the radius of curvature of the top portion of the bottom edge W4 of the crucible (the ratio of the radius ratio below), and the vertical axis indicates the ratio of the front luminance. As shown in Fig. 21, the smaller the radius of curvature ratio, the higher the front luminance ratio. [Embodiment 6] Investigate the change in the front luminance with respect to the contact angle 0 20 with respect to the cylindrical mirror portion. The top curvature radius R0 and the pitch P2 of the cylindrical mirror portion are the same as in the third example, and the contact angle of the cylindrical mirror portion is the same. The shape of the trapezoidal cylindrical lens portion and the base portion of each optical sheet is the same as in the inventive examples 3 and 4. The front surface brightness is obtained for the optical sheet that has been produced, and the actual brightness is obtained. The ratio of the front luminance of the prism sheet of the comparative example (front luminance is shown in Fig. 22). The horizontal axis in Fig. 22 is the contact angle 0 20, and the vertical axis is the front luminance ratio. 1 picture front brightness with contact angle 0 20 When the contact angle is 60 degrees or more, the front luminance is gradually increased, and the above-described embodiment is an exemplary embodiment of the present invention. The present invention is not limited to the above-described embodiments, and may be appropriately scaled without departing from the spirit and scope of the invention. The invention is not limited to the shape of the invention.实-29- 200831951 The above embodiment is applied. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing a display device including an optical sheet according to an embodiment of the present invention. Fig. 2 is a cross-sectional view taken along the line II-π in Fig. 1. Figure 3 is a perspective view of the optical sheet in Fig. 2. Table 4 is a cross-sectional view of the IV-IV line in Fig. 3. Fig. 5 is a cross-sectional view taken along the line V - V in Fig. 3. Fig. 6 is a view showing the relationship between the shape of the trapezoidal lenticular lens portion and the front luminance in the optical sheet shown in Fig. 3. Fig. 7 is another view showing the relationship between the shape of the trapezoidal lens portion and the front surface luminance which are different from Fig. 6. Fig. 8 is a view showing the relationship between the gap between adjacent trapezoidal lens portions and the front luminance, in the optical sheet shown in Fig. 3. Fig. 9 is a perspective view of another optical sheet different from Fig. 3. The first map is a cross-sectional view of the X-X line in Fig. 10. Fig. 1 is a cross-sectional view taken along line XI-XI of Fig. 10. Fig. 12 is a view showing the dependence of the brightness angle of the optical sheet of Example 1 of the first embodiment. Fig. 1 is a view showing the dependence of the brightness angle of the optical sheet of Example 2 of the first embodiment. Fig. 14 is a view showing the dependence of the brightness angle of the optical sheet of Example 3 of the first embodiment. -30- 200831951 Fig. 15 is a view showing the dependence of the brightness angle of the optical sheet of Example 4 of the first embodiment. Figure 16 is a graph showing the dependence of the brightness angle of the optical sheet of Example 5 of the first embodiment. Fig. 17 is a view showing the dependence of the brightness angle of the optical sheet produced in Example 3. Fig. 18 is a view showing the relationship between the apex angle of the optical sheet and the front luminance. Fig. 19 is a view showing the dependence of the brightness angle of the optical sheet produced in Example 4. Fig. 20 is a view showing the dependence of the brightness of the optical sheet produced in the fourth embodiment on the brightness angle of the optical sheet produced in the fourth embodiment. Fig. 2 is a view showing the relationship between the radius of curvature of the upper portion of the dome of the optical sheet on the top of the crotch portion and the front luminance. Fig. 22 is a view showing the relationship between the contact angle of the cylindrical mirror portion of the optical sheet and the front luminance. Figure 23 is a perspective view of a conventional bract. Figure 24 is a cross-sectional view taken along the line XXIV - XXIV in Figure 23. Fig. 25 is a view showing the dependence of the brightness angle of the prism sheet. [Description of main component symbols] 1 : Display device 1 0 : Backlight device 1 6 : Surface light source - 31 - 200831951 17 : Optical sheet 1 8 : 稜鏡 layer 1 9 : Trapezoidal cylindrical lens layer 21 : Substrate portion 2 2 : Prism portion 23: cylindrical mirror portion 2 4 : trapezoidal cylindrical lens portion 2 5 : array lens layer 2 1 8 : bottom surface