201207515 六、發明說明： 【發明所屬之技術領域】 本發明，是關於對液晶元件的定向膜、或是對視野角 補償薄膜的定向層等，照射預定波長的偏光光線來進行定 向的偏光光線照射裝置。 【先前技術】 近年，關於以液晶面板爲首之液晶顯示元件的定向膜 、或是視野角補償薄膜的定向層等之定向處理，逐漸採用 :照射紫外線區域之波長的偏光光線來進行定向，被稱作 爲光定向的技術。以下，將藉由光進行定向的定向膜、或 是設有定向層的薄膜等，藉由光可產生定向特性的膜或層 ，總稱爲光定向膜。 光定向膜，伴隨著液晶面板的大型化，而大面積化成 爲例如一邊2 0 0 0 m m以上的四角形。 爲了對如上述般之大面積的光定向膜進行光定向，提 案出組合棒狀的燈、以及具有金屬絲柵格狀之光柵的偏光 元件（以下稱爲：光柵偏光元件）而成的偏光光線照射裝 置（例如請參照專利文獻1或專利文獻2 )。 光定向膜用的偏光光線照射裝置中的棒狀燈，係可以 製成發光長度較長者。因此，使用具備有··與定向膜寬度 相對應之發光長度的棒狀燈，只要一面照射來自該燈的光 線，一面使定向膜朝向與燈的長邊方向垂直相交之方向移 動，就能夠以較短時間對寬廣面積的定向膜進行光定向處 -5- 201207515 理。 於第7圖，是顯示組合有：作爲線狀光源的棒狀燈以 及光柵偏光元件之偏光光線照射裝置的構成例。 於同圖中，爲光定向膜的工件3 0，例如是視野角補 償薄膜般之帶狀的長條工件，從導出輥筒R 1所導出，並 被朝向圖中箭頭方向搬運，如後述方式藉由偏光光線照射 而被光定向處理，然後藉由捲取輥筒R2而被捲取。 偏光光線照射裝置的光線照射部2 0，係具備：可放 射光定向處理所必須之波長之光線（紫外線）的棒狀燈 2 1，例如爲高壓水銀燈、或是於水銀中加入其他金屬的金 屬鹵素燈、及將來自棒狀燈21的紫外線朝向工件3 0予以 反射之斷面爲橢圓形之溝槽型的反射鏡22。如上述般地 ，棒狀燈21的長度上，其發光部，是使用具備有：與工 件30之搬運方向垂直相交之方向的寬度相對應之長度者 ，且上述棒狀燈2 1是以位於上述橢圓形狀之反射鏡22之 第1焦點的位置之方式而配置。 光線照射部20，是以使其燈2 1的長邊方向成爲工件 3〇之寬度方向（相對於搬運方向爲垂直相交方向）之方 式而配置。 於光線照射部20的光線射出側，設置有作爲偏光元 件的光栅偏光元件10，並於上述橢圓形狀之反射鏡22的 第2焦點，配置有工件30。 來自光線照射部20的光線，是由光柵偏光元件1 0所 偏光後，照射於被搬運至光線照射部20下方的工件3 0， -6 - 201207515 而進行光定向處理。 關於光柵偏光元件（金屬絲光柵型的偏光元件），例 如於專利文獻3或是專利文獻4中有詳細揭示。 當於光路徑中插入該偏光元件時，與光柵的長邊方向 平行的偏光成分大部分都被反射，而只有垂直相交的偏光 成分會通過。因此，通過光柵偏光元件的光線，是成爲具 有與偏光元件之光柵的長邊方向正交之方向之偏光軸的偏 光光線。 以往，作爲光定向膜用的偏光光線照射裝置，於線狀 光源的棒狀燈組合光柵偏光元件來進行是基於以下的理由 〇 從棒狀燈發出的光線爲發散光，所以即使將偏光元件 配置於燈的射出側來取得偏光光線時，仍會有各種角度的 光線入射於偏光元件。 作爲偏光元件者，周知有利用蒸著膜或是布魯斯特角 者。但是，此等的偏光元件，只能夠將在偏光元件所取決 的角度下所入射的光予以偏光，而以其他以外之角度所入 射的光，就幾乎不予以偏光地使之通過。因此，光源爲發 散光時，若是使用利用蒸著膜或布魯斯特角的偏光元件時 ，相較於使入射於偏光元件之光線成爲平行光地使入射角 度齊一之情形，所取得之偏光光線的消光比較差。 又，雖然也有利用有機膜的偏光元件，不過由於此種 元件，若長時間照射用以進行光定向所使用之紫外線區域 的光線時其特性會劣化，所以難以使用在工業上。 201207515 此相對於，光柵偏光元件，其出射之偏光光線的消光 比，相對於入射至偏光元件之光線角度的依存性較小。因 此，即使如從棒狀燈所射出之光線般的發散光，只要入射 角度在±45°的範圍，便可及於光線所照射的區域整體，取 得比較良好之消光比的偏光光線。 因此，只要使棒狀燈的長度，對應光定向膜的寬度而 設置，並使光定向膜對偏光光線照射裝置相對性地朝向一 個方向移動的話，在原理上，以1支燈，便可以進行寬廣 面積之光定向膜的定向處理。 因此’只要將光柵偏光元件組合於棒狀燈，以1支燈 ，便可以進行寬廣面積之光定向膜的定向處理，所以可以 較低價地製造裝置整體。 [先前技術文獻] [專利文獻1]日本特開2006-126464號公報 [專利文獻2]日本特開2009-265290號公報 [專利文獻3]日本特開2002-328234號公報 [專利文獻4]日本特表2003-508813號公報 [專利文獻5]日本特開2006-184747號公報 【發明內容】 [發明所要解決之問題] 如上所述’光柵偏光元件，其入射角度依存性較小， 對於斜向入射的光線也能夠予以偏光。但是，吾人在實驗 -8- 201207515 之後，得知由斜向入射於偏光元件之光線所形成的偏光光 線，相較於以垂直或是接近於該角度所入射之光線所形成 的偏光光線，其有偏光軸旋轉，而產生偏光軸偏離（以下 稱爲：軸偏離）的現象。當偏光光線產生軸偏離時，在光 線照射區域中就會產生偏光軸的變異（v a r i a t i ο η )。 若藉由偏光軸有變異的偏光光線來進行光定向處理時 ，使用經處理後之定向膜所製作的液晶顯示元件的對比會 依處所而有不同，因而產生看見不規則斑影的問題。因此 ，被要求須儘可能地縮小在光照射區域之偏光軸的變異。 於專利文獻5，在光線照射區域之偏光軸的變異，是 入射於光柵偏光子之光線的角度愈大，則從偏光子所射出 之偏光光線之偏光軸的旋轉量就愈大，表示在光線照射區 域之偏光軸的變異就會變愈大。 於上述第7圖所示的偏光光線照射裝置，是使用斷面 爲橢圓形狀的反射鏡22，使棒狀燈2 1以位於上述橢圓形 狀之反射鏡22之第1焦點的位置之方式來配置，而於橢 圓形狀之反射鏡22的第2焦點，配置工件30。因此，斜 向入射於偏光元件的光線會變得較多，使偏光軸的變異增 大。 如上所述地，在以往的偏光光線照射裝置中，並無法 充分因應要儘可能縮小偏光軸之變異如此的期望。 本發明是有鑑於上述情事而硏創的，本發明的目的， 是針對於具有：線狀的光源、及反射來自該光源之光線的 溝槽型反射鏡、以及將上述光源與由上述反射鏡所反射的 -9 - 201207515 光線予以偏光的光柵偏光元件之偏光光線照射裝置 照射區域中之偏光軸的變異儘可能地予以縮小。 [發明解決問題之技術手段] 爲了使在光照射區域中之偏光軸的變異變小， 及縮小入射於光柵偏光元件之光線的角度（使朝向 件之入射角接近於〇°)爲理想。 在此，思及對於作爲使來自棒狀燈之紫外線朝 進行反射之溝槽型的反射鏡，取代以往所使用之斷 圓形狀者，而使用其斷面爲拋物線狀者。 第1表是表示反射鏡之斷面爲橢圓形狀時與拋 時之偏光軸不均的情形。又，該表係顯示藉由計算 之結果。第1表（a )是顯示當棒狀燈之弧光直 1 0 m m之情形時，使用斷面爲拋物線狀（p a r a b ο 1 a ) 焦點F 1的位置爲20mm (反射鏡之拋物線的頂點 的距離，以下相同）的反射鏡、及斷面爲橢圓形狀 )且第1焦點F1的位置爲20mm而第2焦點F2的 lOOmm的反射鏡、以及斷面爲橢圓形狀（橢圓） 焦點F1的位置爲20mm而第2焦點F2的位置爲 的反射鏡，將燈之弧光中心配置於第1焦點F1之 的軸不均（土[deg])。又，斷面爲拋物線狀的反射 沒有第2焦點F2，不過在此是以F2等於無限大來! 又’第1表（b )是顯示當棒狀燈之弧光 3 2.5mm之情形時，使用斷面爲拋物線狀（parabola ，將光 因而思 偏光元 向工件 面爲橢 物線狀 所求得 徑爲φ 且第1 與焦點 (橢圓 位置爲 且第1 2 00mm 位置時 鏡雖然 顏示。 直徑爲 )且第 -10- 201207515 1焦點F 1的位置爲2 5 m m的反射鏡、及斷面爲橢圓形狀 (橢圓）且第1焦點F1的位置爲25mm而第2焦點F2的 位置爲1 〇〇mm的反射鏡、以及斷面爲橢圓形狀（橢圓） 且第1焦點F1的位置爲25mm而第2焦點F2的位置爲 2 0 0 m m的反射鏡’將燈之弧光中心配置於第}焦點f 1之 位置時的軸不均（±[deg])。 [第1表] (a )將弧光中心配置於F 1，弧光直徑φ 1 〇mm 拋物線 橢圓 橢圓 F1 20 20 20 F2 〇〇 100 200 軸不均±[deg] 0.662 2.896 1.873 (b )將弧光中/ 1、配置於F 1 ，弧光直徑 Φ 3 2.5mm 拋物線 橢圓 橢圓 F1 25 25 25 F2 〇〇 100 200 軸不均±[deg] 0.787 2.365 1.629 從同表可明瞭地，使用斷面爲橢圓形狀之反射鏡時的 軸不均是相對於使用斷面爲拋物線（Parabola )之反射鏡 時的軸不均的2〜3倍，因此藉由使用斷面爲拋物線（ parabola )的反射鏡，可以大幅地減少偏光軸的軸不均。 如以上所說明，使用斷面爲拋物線狀之反射鏡’藉由 將燈的中心配置在該反射鏡之拋物線的第1焦點，使反射 鏡的反射光成爲平行光’以較小的入射角度（以垂直或接 -11 - 201207515 近垂直之角度）入射於光栅偏光元件，因此在光照射區域 中之偏光軸的變異較小。 但是，來自燈的直射光也會入射於光柵偏光元件。而 從燈所放射的光爲發散光，其中亦有相對於光柵偏光元件 以較大的入射角度入射的成分。 因此，了解到即是是使用斷面爲拋物線狀之呈溝槽型 的反射鏡，來作爲將來自線狀光源的光線予以反射的反射 鏡，也無法完全消弭在光照射區域中之偏光軸的變異。 爲了解決上述問題，進行了各種檢討的結果，得知除 了作爲反射鏡要使用斷面爲拋物線狀的反射鏡，並且使燈 的中心（發光部）朝向比該反射鏡的第1焦點更稍微靠近 偏光元件側移動，如此之在光照射區域中之偏光軸的變異 ，可以變得較小。 更詳言，是將燈的中心，配置在：其斷面爲拋物線之 反射鏡的第1焦點與頂點所連結的直線上，且是在第1焦 點與光柵偏光元件之間。藉由將燈配置於如此的位置，相 較於將燈配置於第1焦點之情形時，可以縮小在光照射區 域中之偏光軸的變異。 不過，當燈的中心過於離開第1焦點時，則偏光軸的 變異會再次變大。因此，使燈的中心從第1焦點朝向偏光 元件之方向移動的距離’以反射鏡之焦點距離的1 /2左右 爲止之距離較爲理想。 [發明效果] -12- 201207515 在本發明中，由於是使用斷面爲拋物線狀者，來作爲 將來自棒狀燈之紫外線朝向工件反射之呈溝槽型的反射鏡 ，且將上述燈的中心，配置在上述反射鏡的第1焦點與光 柵偏光元件之間，所以相較於如以往般之斷面爲橢圓形狀 之呈溝槽型的反射鏡之情形，可以減少在光照射區域中之 偏光軸的變異。 【實施方式】 [用以實施本發明之形態] 於第1圖（a )是顯示組合有本發明之實施例之溝槽 型反射鏡、及作爲線狀光源之棒狀燈、以及光栅偏光元件 之偏光光線照射裝置的構成例，於同圖（b )( c )是顯示 反射鏡與棒狀燈的放大圖。又，於同圖（d)是顯示燈的 斷面形狀。 於同圖（a )，爲光定向膜的工件3 0，係如前述例如 爲視野角補償薄膜般之帶狀的長條工件，並從導出輥筒 R1所導出’而被朝向圖中箭頭方向搬運，藉由如後述之 偏光光線照射進行光定向處理後，藉由捲取輥筒r2所捲 取。 偏光光線照射裝置的光線照射部20，係具備有·：方女 射出光定向處理所必須之波長之光線（紫外線）的棒狀燈 1，例如是筒壓水銀燈或是於水銀再加上其他金屬的金屬 鹵素燈、及將來自棒狀燈1之紫外線朝向工件3 0反射之 溝槽型的反射鏡2。 -13- 201207515 棒狀燈1的長度，是使用其發光部具備有：與工件 30搬運方向正交之方向上的寬度相對應之長度者。光線 照射部20，是使燈1的長邊方向以成爲工件30的寬度方 向（相對於搬運方向爲正交方向）之方式而配置。於光線 照射部2 0的光線射出側，設置作爲偏光元件的光柵偏光 元件1 〇。 來自棒狀燈1的光線，係直接入射於光柵偏光元件 10，並且由反射鏡2反射而入射於光柵偏光元件10，藉 由光柵偏光元件1 〇而被偏光，照射於被搬運至光線照射 部20下方的工件30，來進行光定向處理。 第1圖（b)爲上述反射鏡2的立體圖，第1圖（c) 爲棒狀燈1的立體圖，第1圖（d)是將棒狀燈以垂直於 管軸的平面予以剖切的斷面圖。 反射鏡2的內側，是將從燈所放射的光線予以反射的 反射面，於該反射鏡2的內側，配合長度方向地配置有棒 狀燈。 反射鏡2，是如上所述，其斷面爲拋物線狀之溝槽型 的鏡，並使棒狀燈1的長邊方向爲平行於上述溝槽型之反 射鏡2的長邊方向地配置。而且，棒狀燈的中心（位於將 棒狀燈以垂直於管軸的平面予以剖切之斷面的中心位置， 亦即光源的中心），是位在連結上述斷面爲拋物線之反射 鏡之第1焦點與拋物線頂點的直線上，且是被配置在比上 述第1焦點更靠近上述光柵偏光元件1 0側。 在此，反射鏡2之所謂「斷面爲拋物線狀」，是指相 -14- 201207515 對於該溝槽型之反射鏡2的長邊方向呈正交之方向之斷面 的反射面形狀，爲拋物線狀。反射鏡2，於實際上具有如 同圖所示地，於頂部形成有通風孔等之開口之情形，不過 於此情形時也是「其斷面爲拋物線狀」。 又，由於反射鏡2爲溝槽型，所以反射鏡2的第1焦 點，是沿著反射鏡2的長邊方向連續性地存在。因而在此 ，將作爲第1焦點之集合體的直線，稱之爲「溝槽型之鏡 的第1焦點」。 再者，所謂使反射鏡2的第1焦點與燈1的中心一致 ，是指：使作爲反射鏡2之第1焦點之集合體的直線，與 燈的中心線一致的意思。 所謂燈的中心線，是於第1圖（d )所示之斷面圖中 ，棒狀燈1之圓環狀封體（玻璃管）1 a之內徑之中心（ 弧光中心）點之燈長邊方向的集合體。亦即，位於將棒狀 燈以垂直於管軸的平面予以剖切後之斷面之作爲內徑之中 心點的集合體且沿著燈之長邊方向的直線，是相當於光源 的中心。 又，燈雖分爲於內部具備有電極的有電極燈與於內部 沒有電極的無電極燈，但無論是哪一種，都將封體之圓環 的軸本身稱之爲燈的中心。 以下調查了在由：上述本發明之實施例之溝槽型而斷 面爲拋物線狀的反射鏡及棒狀燈、以及光栅偏光元件所組 合的偏光光線照射裝置中之燈的位置與偏光軸之變異（ variation)的關係。 -15- 201207515 如第2圖所示’使燈1平行移動在由斷面爲抛物線狀 之反射鏡2的第1焦點（F1 )與鏡2的拋物線頂點p所連 結的直線上》亦即，改變燈1的中心與焦點F1的距離d (位置偏離量）來調查偏光軸的變異。又，如上述般地， 亦有於反射鏡2的頂部形成有開口者，若是如此之情形者 ’頂點P係將形成拋物線之一部分之反射鏡2的斷面予以 外插後求得。 拋物線狀的反射鏡2，係對於焦點距離不同者準備3 種（f = 18mm、20mm、25mm)，以及準備棒狀燈 1其封 體之管徑（內徑）爲不同者複數支，分別予以組合並調查 〇 燈1的管徑，爲現在一般所使用之代表性的棒狀燈的 管徑。燈的管徑，雖然較細者輝度較高，因而可取得較高 的峰値照度。但是，燈的長度一增長時，爲了保持強度而 有變粗的傾向。 第3圖’是顯示以溝槽型其斷面爲拋物線狀之反射鏡 其焦點距離爲1 8mm之情形下，使管的內徑爲9mm、 18mm、23.4mm的棒狀燈，分別移動在連結第1焦點（F1 )與拋物線頂點的直線上之情形時，光線照射區域之偏光 軸之變異的變化。於同圖中，橫軸是從第1焦點至燈的中 心爲止的距離，縱軸是偏光軸之變異（軸不均）的大小。 又，所謂偏光軸，是以方位角來顯示位於光線照射區 域之某點的偏光方向者。又，偏光軸之變異（軸不均）的 大小係如第6圖所示，是以偏光光線所照射之區域的中心 -16- 201207515 位置之偏光軸的方向作爲基準，測量光線照射區域四角落 之偏光軸的方向，並以± 0 /2作爲開啓角0來表示旋轉了 幾度。 回到第3圖，橫軸之0的位置是位於第1焦點（F i ) 的位置，偏離量爲正側（比0更右側），是表示使燈從第 1焦點（F 1 )朝向光柵偏光元件側移動之情形；偏離量爲 負値側（比〇更左側），是表示使燈從第1焦點（F1 )朝 向與光柵偏光元件爲相反側移動之情形。 第4圖，是在具溝槽形狀且斷面爲拋物線狀之反射鏡 的焦點距離爲20mm之情形下，使用管之內徑爲l〇mm、 2 0 m m、2 6 m m之棒狀燈的情形。 第5圖，是在具溝槽形狀且斷面爲拋物線狀之反射鏡 的焦點距離爲25mm之情形下，使用管之內徑爲12.5mm 、2 5 m m、3 2.5 m m之棒狀燈的情形。 由第3、4、5圖，可以得知以下的硏創心得。 當使燈，相對於第1焦點（F1 )朝向與光柵偏光元件 爲相反側移動時，偏光軸的變異（軸不均）會變大。 不過，即使是反射鏡之第1焦點（F1 )的位置有所不 同，相較於將燈的中心配置在第1焦點（F 1 )時之偏光軸 的變異（軸不均），使燈的中心從第1焦點（F 1 )朝向偏 光子側移動才更可以使偏光軸的變異（軸不均）變小，且 無關於燈管（內徑）的大小。 因此，針對於具備有：線狀的光源、及具有反射來自 該光源之光的溝槽型且斷面爲抛物線狀的反射鏡、以及用 -17- 201207515 以將此光源與由反射鏡所反射的光予以偏光的 件等之偏光光線照射裝置，爲了縮小偏光軸的 均），是將燈（的中心），以配置在反射鏡之 頂點所連結的直線上，且是在第1焦點與偏光 佳。 不過，從第1焦點（F1 )到燈爲止的距離 某程度以上時，則偏光軸的變異（軸不均）就 加。因此，偏光軸之變異（軸不均）爲最小時 ，就必須因應反射鏡的焦點距離與燈的內徑， 等來求得。 如上所述，若燈的中心離第1焦點太遠的 軸的變異會再次變大。因此，使燈的中心從第 偏光元件的方向移動的距離，是以到反射鏡之 1 /2左右的距離爲止爲佳，例如，焦點距離爲 射鏡的情形時爲至 9mm; 20mm之反射鏡的 10mm; 25mm之反射鏡的情形時爲至12.5mm f 當使燈的中心從第1焦點（F 1 )朝向偏光 時，燈管之內徑較小者，可更加改善偏光軸的 均）。 【圖式簡單說明】 第1圖是顯示本發明之實施例之偏光光線 構成。 第2圖是說明在本發明中，反射鏡及燈及 光柵偏光元 變異（軸不 第1焦點與 元件之間爲 ，若是超過 會轉成爲增 之燈的位置 事先以實驗 話，則偏光 1焦點朝向 焦點距離的 1 8mm之反 丨青形時爲至 i止。 元件側移動 變異（軸不 照射裝置的 金屬絲光柵 -18 - 201207515 偏光元件之配置的圖面。 第3圖是顯示移動在連結第1焦點（f 1 )與拋物線頂 點之直線上時’光線照射區域之偏光軸之變異變化的圖（ 1 )- 第4圖是顯示移動在連結第1焦點（F 1 )與拋物線頂 點之直線上時，光線照射區域之偏光軸之變異變化的圖（ 2 ) 〇 第5圖是顯示移動在連結第1焦點（F 1 )與拋物線頂 點之直線上時，光線照射區域之偏光軸之變異變化的圖（ 3 ) ° 第6圖是說明偏光軸之變異的圖面。 第7圖是顯不使用棒狀燈、反射鏡、以及光柵偏光元 件之偏光光線照射裝置之構成例的圖面。 【主要元件符號說明】 1 :棒狀燈 2 :反射鏡 1 〇 :光柵偏光元件 2〇 :光線照射部 3 0 :工件 R1 :導出輥筒 R2 :捲取輥筒201207515 VI. Description of the Invention: [Technical Field] The present invention relates to an orientation film of a liquid crystal element, or an alignment layer of a viewing angle compensation film, or the like, which irradiates a polarized ray of a predetermined wavelength to perform directional polarized light irradiation. Device. [Prior Art] In recent years, the orientation treatment of an alignment film of a liquid crystal display element such as a liquid crystal panel or an alignment layer of a viewing angle compensation film has been gradually adopted: a polarized light that irradiates a wavelength of an ultraviolet region is used for orientation, and is oriented. Called as a technology for light orientation. Hereinafter, an oriented film which is oriented by light, or a film provided with an alignment layer, or the like, or a film or layer which can produce directional characteristics by light, is collectively referred to as a light directing film. The light-oriented film has a large area, for example, a square shape of, for example, a side of 200 m m or more. In order to perform light orientation on a large-area light-aligning film as described above, a polarized ray in which a rod-shaped lamp and a polarizing element having a grating of a wire grid (hereinafter referred to as a grating polarizing element) are proposed is proposed. Irradiation device (for example, refer to Patent Document 1 or Patent Document 2). The rod-shaped lamp in the polarized light irradiation device for a light directing film can be made to have a longer light-emitting length. Therefore, by using a rod-shaped lamp having a light-emitting length corresponding to the width of the orientation film, it is possible to move the alignment film in a direction perpendicular to the longitudinal direction of the lamp while irradiating the light from the lamp. Short-term light orientation of a wide area of oriented film -5 - 201207515. Fig. 7 shows an example of the configuration of a polarized light irradiation device in which a rod-shaped lamp as a linear light source and a grating polarizing element are combined. In the same figure, the workpiece 30 which is a light-oriented film, for example, a strip-shaped long workpiece such as a viewing angle compensation film, is taken out from the take-up roll R 1 and conveyed in the direction of the arrow in the drawing, as will be described later. It is subjected to light orientation treatment by irradiation of polarized light, and then taken up by winding up the roll R2. The light-irradiating portion 20 of the polarized light irradiation device includes a rod-shaped lamp 2 1 that can emit light of a wavelength (ultraviolet light) necessary for the light-directing treatment, for example, a high-pressure mercury lamp or a metal in which other metals are added to the mercury. A halogen lamp and a groove-shaped mirror 22 having an elliptical cross section in which ultraviolet rays from the rod lamp 21 are reflected toward the workpiece 30 are formed. As described above, in the length of the rod-shaped lamp 21, the light-emitting portion is formed to have a length corresponding to a width perpendicular to the direction in which the workpiece 30 is conveyed, and the rod-shaped lamp 2 1 is located. The position of the first focus of the elliptical mirror 22 is arranged. The light-irradiating portion 20 is disposed such that the longitudinal direction of the lamp 2 1 is in the width direction of the workpiece 3 (the direction perpendicular to the conveyance direction). A grating polarizing element 10 as a polarizing element is provided on the light emitting side of the light irradiation unit 20, and a workpiece 30 is disposed on the second focus of the elliptical mirror 22. The light from the light-irradiating portion 20 is polarized by the grating polarizing element 10, and then irradiated onto the workpieces 3 0, -6 - 201207515 conveyed under the light-irradiating portion 20 to perform light directing processing. The grating polarizing element (wire grating type polarizing element) is disclosed in detail in Patent Document 3 or Patent Document 4, for example. When the polarizing element is inserted in the light path, most of the polarizing components parallel to the longitudinal direction of the grating are reflected, and only the vertically intersecting polarizing components pass. Therefore, the light passing through the grating polarizing element is a polarized ray having a polarization axis in a direction orthogonal to the longitudinal direction of the grating of the polarizing element. Conventionally, as a polarized light illuminating device for a light directing film, a rod-shaped lamp combined with a grating polarizing element of a linear light source is used for the following reasons: The light emitted from the rod-shaped lamp is divergent light, so even if the polarizing element is disposed When the polarized light is obtained on the emission side of the lamp, light of various angles is incident on the polarizing element. As a polarizing element, it is known to use a vaporized film or a Brewster horn. However, in such a polarizing element, only light incident at an angle determined by the polarizing element can be polarized, and light incident at other angles can be transmitted without being polarized. Therefore, when the light source is divergent light, if a polarizing element using a vapor deposition film or a Brewster angle is used, the incident light is obtained by making the incident angle uniform when the light incident on the polarizing element is parallel light. The extinction is poor. Further, although a polarizing element using an organic film is also used, such a device is difficult to use industrially when the light of the ultraviolet region used for light orientation is irradiated for a long period of time. 201207515 In contrast to the grating polarizing element, the extinction ratio of the emitted polarized light is less dependent on the angle of the light incident on the polarizing element. Therefore, even if the divergence light is emitted from the light emitted from the rod-shaped lamp, as long as the incident angle is within the range of ±45°, the polarized light having a relatively good extinction ratio can be obtained as a whole in the region irradiated with the light. Therefore, if the length of the rod-shaped lamp is set to correspond to the width of the light-aligning film, and the light-directing film is relatively moved in one direction with respect to the polarized light irradiation device, in principle, one lamp can be used. Orientation treatment of a wide area of light oriented film. Therefore, as long as the grating polarizing element is combined with the rod-shaped lamp, the alignment treatment of the light-oriented film of a wide area can be performed with one lamp, so that the entire apparatus can be manufactured at a lower price. [PRIOR ART DOCUMENT] [Patent Document 1] Japanese Laid-Open Patent Publication No. JP-A-2002-265290 (Patent Document 3) [Patent Document 5] Japanese Laid-Open Patent Publication No. 2006-184747 [Draft] [Problems to be Solved by the Invention] As described above, the 'grating polarizing element has a small incident angle dependency, and is oblique. The incident light can also be polarized. However, after experiment -8-201207515, we know that the polarized light formed by the light obliquely incident on the polarizing element is compared with the polarized light formed by the light incident perpendicular or close to the angle. There is a phenomenon in which the polarization axis rotates and the polarization axis deviation (hereinafter referred to as axis deviation) occurs. When the polarized light produces an axis deviation, a variation (v a r i a t i ο η ) of the polarization axis occurs in the light irradiation region. When the light directing treatment is performed by the polarized light having a variable polarization axis, the contrast of the liquid crystal display elements produced by using the treated alignment film may vary depending on the location, thereby causing a problem of seeing irregular spots. Therefore, it is required to reduce the variation of the polarization axis in the light irradiation region as much as possible. In Patent Document 5, the variation of the polarization axis in the light-irradiating region is such that the larger the angle of the light incident on the grating polarizer, the larger the amount of rotation of the polarization axis of the polarized light emitted from the polarizer is expressed in the light. The variation of the polarization axis of the illumination area becomes larger. In the polarized light irradiation device shown in Fig. 7, the mirror 22 having an elliptical cross section is used, and the rod lamp 2 1 is disposed so as to be positioned at the first focus of the elliptical mirror 22. The workpiece 30 is placed at the second focus of the elliptical mirror 22 . Therefore, the amount of light incident on the polarizing element obliquely becomes large, and the variation of the polarization axis is increased. As described above, in the conventional polarized light irradiation apparatus, it is not possible to sufficiently reduce the variation of the polarization axis as much as possible. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a light source having a line shape, a groove type mirror that reflects light from the light source, and the light source and the mirror. The reflected -9 - 201207515 ray variation of the polarization axis in the illuminating region of the polarized light illuminating device of the grating polarizing element which is polarized is reduced as much as possible. [Technical means for solving the problem] It is preferable to reduce the variation of the polarization axis in the light irradiation region and to reduce the angle of the light incident on the grating polarizing element (the incident angle of the facing member is close to 〇°). Here, as for the groove type mirror which reflects the ultraviolet rays from the rod-shaped lamp, a parabolic shape is used instead of the conventionally used circular shape. The first table shows a case where the cross-sectional axis of the mirror is not uniform when the cross section of the mirror is elliptical. Again, the watch shows the results by calculation. Table 1 (a) shows the position of the parabola (parab ο 1 a ) focus F 1 when the arc of the rod lamp is straight 10 mm (the distance of the apex of the parabola of the mirror) The mirrors of the same shape and the elliptical shape are 20 mm, the mirror of the first focus F1 is 20 mm, the mirror of the first focus F2 is 100 mm, and the section having the elliptical shape (ellipse) and the focal point F1 is 20 mm. On the other hand, the mirror at the position of the second focus F2 has an axis unevenness (soil [deg]) at which the arc center of the lamp is disposed at the first focus F1. Further, the parabolic reflection has no second focus F2, but here F2 is equal to infinity! And the 'first table (b) is used when the arc of the rod lamp is 3 2.5 mm. The cross section is parabolic (parabola, the light is thus obtained from the polarizing element to the workpiece surface as the ellipsoid line, and the diameter is φ and the first and the focal point (the elliptical position is at the 1st 00mm position, although the mirror is shown. -10-201207515 1 The position of the focus F 1 is 25 mm, and the cross section is elliptical (elliptical), and the position of the first focus F1 is 25 mm and the position of the second focus F2 is 1 〇 a mirror of 〇mm and a mirror having an elliptical shape (ellipse) and a position of the first focus F1 of 25 mm and a position of the second focus F2 of 200 mm are arranged at the center of the arc of the lamp Axis unevenness at the position of f 1 (±[deg]). [Table 1] (a) Arrange the center of the arc at F 1, the diameter of the arc φ 1 〇 mm Parabolic ellipse ellipse F1 20 20 20 F2 〇〇100 200 Axis unevenness ±[deg] 0.662 2.896 1.873 (b) Arc in /1, in F 1 , arc diameter Φ 3 2.5mm parabola Line ellipse ellipse F1 25 25 25 F2 〇〇100 200 Axis unevenness ±[deg] 0.787 2.365 1.629 From the same table, it is clear that the shaft unevenness when using a mirror with an elliptical cross section is relative to the used cross section. Since the parabola mirror has an axial unevenness of 2 to 3 times, the use of a parabola having a cross section can greatly reduce the axial disparity of the polarizing axis. As explained above, A parabolic mirror with a section 'by arranging the center of the lamp at the first focus of the parabola of the mirror, making the reflected light of the mirror parallel light' at a small angle of incidence (in vertical or -11) - 201207515 Near vertical angle) is incident on the grating polarizing element, so the variation of the polarization axis in the light irradiation area is small. However, direct light from the lamp is also incident on the grating polarizing element, and the light emitted from the lamp is Diverging light, which also has a component incident at a larger incident angle with respect to the grating polarizing element. Therefore, it is understood that a parabolic mirror-shaped mirror having a cross-section is used as the The mirror that reflects light from the linear light source cannot completely eliminate the variation of the polarization axis in the light-irradiated area. In order to solve the above problems, various reviews have been carried out, and it has been found that the cross-section is used in addition to being a mirror. a parabolic mirror, and the center of the lamp (light emitting portion) is moved closer to the side of the polarizing element toward the first focus of the mirror, so that the variation of the polarization axis in the light irradiation region can be made smaller . More specifically, the center of the lamp is placed on a line connecting the first focus and the apex of the mirror whose parabola is a parabola, and between the first focal point and the grating polarizing element. By arranging the lamp at such a position, the variation of the polarization axis in the light irradiation region can be reduced as compared with the case where the lamp is placed at the first focus. However, when the center of the lamp is too far away from the first focus, the variation of the polarization axis becomes larger again. Therefore, it is preferable that the distance of the center of the lamp from the first focus toward the direction of the polarizing element is about 1 / 2 of the focal length of the mirror. [Effect of the Invention] -12-201207515 In the present invention, a parabolic dish is used as a groove-type mirror for reflecting ultraviolet rays from a rod lamp toward a workpiece, and the center of the lamp is used. Since it is disposed between the first focus of the mirror and the grating polarizing element, the polarizing in the light irradiation region can be reduced as compared with the case of the groove-shaped mirror having an elliptical cross section as in the related art. Variation of the axis. [Embodiment] [Formation for Carrying Out the Invention] FIG. 1(a) shows a groove type mirror in which an embodiment of the present invention is combined, a rod-shaped lamp as a linear light source, and a grating polarizing element. An example of the configuration of the polarized light irradiation device is shown in the same drawing (b) and (c) as an enlarged view of the display mirror and the rod lamp. Further, in the same figure (d), the cross-sectional shape of the display lamp is shown. In the same figure (a), the workpiece 30 of the light directing film is a strip-shaped long workpiece such as the viewing angle compensation film described above, and is derived from the take-up roll R1 and is oriented in the direction of the arrow in the figure. The conveyance is carried out by photo-alignment treatment by polarized light irradiation as will be described later, and then taken up by the take-up reel r2. The light-irradiating portion 20 of the polarized light irradiation device includes a rod-shaped lamp 1 having a light source (ultraviolet light) of a wavelength necessary for the light-directing treatment of the square, for example, a tube-pressure mercury lamp or mercury and other metals. The metal halide lamp and the groove type mirror 2 that reflects the ultraviolet rays from the rod lamp 1 toward the workpiece 30. -13-201207515 The length of the rod-shaped lamp 1 is such that the light-emitting portion has a length corresponding to the width in the direction orthogonal to the conveyance direction of the workpiece 30. The light-irradiating portion 20 is disposed such that the longitudinal direction of the lamp 1 is in the width direction of the workpiece 30 (orthogonal direction with respect to the conveyance direction). A grating polarizing element 1 作为 as a polarizing element is provided on the light emitting side of the light illuminating unit 20. The light from the rod lamp 1 is directly incident on the grating polarizing element 10, is reflected by the mirror 2, is incident on the grating polarizing element 10, is polarized by the grating polarizing element 1 ,, and is irradiated to the light irradiation portion. The workpiece 30 below 20 is used for light directing processing. Fig. 1(b) is a perspective view of the mirror 2, Fig. 1(c) is a perspective view of the rod lamp 1, and Fig. 1(d) is a view showing the rod lamp cut in a plane perpendicular to the tube axis. Sectional view. The inside of the mirror 2 is a reflecting surface that reflects light emitted from the lamp, and a rod-shaped lamp is disposed inside the reflecting mirror 2 in the longitudinal direction. The mirror 2 is a parabolic trough-shaped mirror as described above, and the longitudinal direction of the rod-shaped lamp 1 is arranged parallel to the longitudinal direction of the mirror-shaped mirror 2. Moreover, the center of the rod-shaped lamp (located at the center of the section in which the rod-shaped lamp is cut in a plane perpendicular to the tube axis, that is, the center of the light source) is located at a mirror that connects the above-mentioned section to a parabola. The first focus is on the straight line of the parabola vertices, and is disposed closer to the grating polarizing element 10 side than the first focus. Here, the "parabolic shape of the cross section" of the mirror 2 refers to the shape of the reflection surface of the cross section of the groove type mirror 2 in the direction in which the longitudinal direction of the groove type mirror 2 is orthogonal. Parabolic. The mirror 2 has a case where an opening such as a vent hole is formed at the top as shown in the figure, but in this case, "the cross section is parabolic". Further, since the mirror 2 is of a groove type, the first focal point of the mirror 2 continuously exists along the longitudinal direction of the mirror 2. Therefore, the straight line which is the aggregate of the first focus is referred to as the "first focus of the mirror of the groove type". In addition, the fact that the first focus of the mirror 2 coincides with the center of the lamp 1 means that the straight line which is the aggregate of the first focus of the mirror 2 coincides with the center line of the lamp. The center line of the lamp is the lamp at the center of the inner diameter (arc center) of the annular seal (glass tube) 1 a of the rod lamp 1 in the sectional view shown in Fig. 1(d). A collection of long-side directions. That is, a straight line which is an assembly of the inner diameter points of the cross section of the rod lamp which is cut in a plane perpendicular to the tube axis and which is along the longitudinal direction of the lamp corresponds to the center of the light source. Further, although the lamp is divided into an electrode lamp having an electrode therein and an electrodeless lamp having no electrode therein, the axis of the ring of the package is referred to as the center of the lamp. The position and the polarization axis of the lamp in the polarized light irradiation device in which the groove type, the parabolic mirror, the rod-shaped lamp, and the grating polarizing element are combined in the above-described embodiment of the present invention are examined. The relationship of variation. -15- 201207515 As shown in Fig. 2, 'the lamp 1 is moved in parallel on a line connecting the first focus (F1) of the parabolic mirror 2 and the parabola p of the mirror 2, that is, The variation of the polarization axis was investigated by changing the distance d (position deviation amount) between the center of the lamp 1 and the focus F1. Further, as described above, an opening is formed on the top of the mirror 2, and if it is such a case, the vertex P is obtained by extrapolating the cross section of the mirror 2 which forms part of the parabola. The parabolic mirror 2 is prepared for three types (f = 18 mm, 20 mm, 25 mm) for different focal lengths, and the tube diameter (inner diameter) of the sealed lamp 1 is different. The diameter of the xenon lamp 1 is combined and investigated, and is the diameter of a representative rod lamp which is generally used nowadays. The diameter of the lamp, although finer, has a higher peak illuminance. However, as the length of the lamp increases, there is a tendency to become thicker in order to maintain strength. Fig. 3 is a view showing a rod-shaped lamp having an inner diameter of a tube of 9 mm, 18 mm, and 23.4 mm in a case where a mirror having a groove shape and a parabolic shape has a focal length of 18 mm, respectively. When the first focus (F1) is on a straight line with the apex of the parabola, the variation of the variation of the polarization axis of the light irradiation region. In the same figure, the horizontal axis represents the distance from the first focus to the center of the lamp, and the vertical axis represents the variation of the polarization axis (axis unevenness). Further, the polarization axis is a person who displays the polarization direction at a certain point in the light irradiation region by the azimuth angle. Moreover, the variation of the polarization axis (axis unevenness) is as shown in Fig. 6, and the four corners of the light irradiation region are measured by using the direction of the polarization axis at the center of the region irradiated by the polarized light to the position -16,075,075. The direction of the polarization axis, with ± 0 /2 as the opening angle 0, indicates a few degrees of rotation. Returning to Fig. 3, the position of 0 on the horizontal axis is at the position of the first focus (F i ), and the amount of deviation is the positive side (more right than 0), indicating that the lamp is directed from the first focus (F 1 ) toward the grating. The case where the polarizing element side moves; the amount of deviation is the negative side (more left than 〇), which means that the lamp is moved from the first focus (F1) toward the opposite side of the grating polarizing element. Fig. 4 is a rod-shaped lamp having an inner diameter of a tube of l〇mm, 20 mm, and 26 mm in the case where the focal length of the mirror having a groove shape and a parabolic cross section is 20 mm. situation. Figure 5 is a diagram showing the case where a rod-shaped lamp having an inner diameter of 12.5 mm, 2 5 mm, and 3 2.5 mm is used in the case where the focal length of the mirror having a groove shape and a parabolic cross section is 25 mm. . From the 3rd, 4th, and 5th pictures, the following ingenuity can be known. When the lamp is moved to the side opposite to the grating polarizing element with respect to the first focus (F1), the variation (axial unevenness) of the polarization axis becomes large. However, even if the position of the first focus (F1) of the mirror is different, the variation of the polarization axis (axis unevenness) when the center of the lamp is placed at the first focus (F 1 ) causes the lamp to When the center moves from the first focus (F 1 ) toward the polarizer side, the variation of the polarization axis (axis unevenness) can be made smaller, and the size of the tube (inner diameter) is not related. Therefore, the present invention is directed to a light source having a linear shape and a mirror having a groove shape reflecting a light from the light source and having a parabolic cross section, and -17-201207515 for reflecting the light source and the mirror In order to reduce the uniformity of the polarization axis, the polarized light irradiation device such as a polarized light is disposed on a straight line connected to the apex of the mirror, and is in the first focus and polarization. good. However, when the distance from the first focus (F1) to the lamp is more than a certain level, the variation of the polarization axis (axis unevenness) is added. Therefore, when the variation of the polarization axis (axis unevenness) is the smallest, it is necessary to obtain the focal length of the mirror and the inner diameter of the lamp. As described above, if the center of the lamp is too far from the first focus, the variation of the axis becomes larger again. Therefore, it is preferable to move the center of the lamp from the direction of the polarizing element to a distance of about 1 / 2 of the mirror. For example, when the focal length is a mirror, it is 9 mm; a mirror of 20 mm 10mm; in the case of a 25mm mirror, it is up to 12.5mm f. When the center of the lamp is directed from the first focus (F 1 ) toward the polarized light, the inner diameter of the lamp tube is smaller, and the uniformity of the polarization axis can be further improved. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing a configuration of a polarized light of an embodiment of the present invention. Fig. 2 is a view showing the variation of the mirror and the lamp and the grating polarizer in the present invention (the axis is not between the first focus and the element, and if it exceeds the position where the lamp is turned into an additional lamp, the polarized light 1 focus is in advance. When the 丨 丨 形 1 1 1 。 。 。 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件 元件Figure 1 (1) of the variation of the polarization axis of the illuminating region when the first focus (f 1 ) is on the straight line with the parabola apex - Fig. 4 shows the line moving in the first focus (F 1 ) and the apex of the parabola In the upper part, the variation of the polarization axis of the light-irradiated area (2) 〇 Figure 5 shows the variation of the polarization axis of the light-irradiated area when moving on the line connecting the first focus (F 1 ) and the parabola apex (3) ° Fig. 6 is a view for explaining the variation of the polarization axis. Fig. 7 is a view showing a configuration example of a polarized light irradiation device which does not use a rod lamp, a mirror, and a grating polarizing element. main Description of component symbols] 1 : Rod lamp 2 : Mirror 1 〇 : Grating polarizing element 2 〇 : Light illuminating part 3 0 : Workpiece R1 : Derivation roller R2 : Reeling roller
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