200424574 (1) 玖、發明說明 【發明所屬之技術領域】 本發明係有關光學低通濾波鏡之製造方法，尤其胃w 關提升將高分子薄膜夾在雙折射板之構造的光學低通德# 1¾之製造良率的技術。 【先前技術】 數位靜像相機或數位視訊攝影機等攝像裝置中經胃_ 用C CD或CMOS等攝像元件。該攝像元件係藉由以所定 間隙配列成矩陣狀的像素而將光學像轉換成電訊號，g @ 像予以攝影。此種攝像裝置中，光學像的空間頻率〜旦^ 過像素支配列間隙所決定的取樣頻率的1 / 2，則會發生 錯網（moire )等之擬似訊號而使畫質下降。 因此，一般的攝像裝置中，在攝像元件的前面，會設 置抑制光學像之空間頻率的高頻成份的光學低通濾波鏡。 該光學低通濾波鏡的構造爲，一般而言，有雙折射板三片 型和雙折射板兩片之間夾著相位板型，也有在兩片型雙折 射板間夾著1 / 4波長板之構造的垂直附加型這類高性能 者爲人所知。 近年來，有人提案使用以一軸延伸法所形成之高分子 薄膜來做爲1/4波長板。藉由使用高分子薄膜，可達到 薄型化及降低製造成本的目的。雙折射板則使用水晶板。 兩片水晶板間夾著高分子薄膜之構造的光學低通濾波 鏡製造之際，需要在高分子薄膜的兩面上使用黏著劑或接 -5- (2) (2)200424574 著劑而將兩片水晶板貼合之工程。 將高分子薄膜貼合在水晶板之際，會有高分子薄膜和 水晶板之間跑入氣泡之情形。由於有氣泡存在就不能當作 光學元件使用，是爲不良，是造成製造良率下降的原因。 將水晶板彼此接著之際，藉由真空氣氛下予以貼合可 以防止氣泡跑入的技術，例如以下專利文獻1已有揭露。 〔專利文獻1〕日本特開2003-29035號公報 【發明內容】 〔發明所欲解決之課題〕 可是在此其中，雖然在真空氣氛下進行壓著不會有氣 泡殘存，而可提升製造良率，但是從大氣壓降至真空爲止 需要花費時間，導致生產效率低落。因此，需要將真空氣 氛下之工程限縮在最小限度內以避免生產效率低落。 又，光學低通濾波鏡製造之際，兩片雙折射板和高分 子薄膜之個別的光學軸必須要正確地配置，因此在真空氣 氛中要求貼合在正確位置上。 本發明係有鑑於上述情事，目的在提供生產效率佳的 光學低通濾波鏡之製造方法，能夠以高分子薄膜和雙折射 板之間不會存在氣泡而製造良率佳的方式在雙折射板上貼 合高分子薄膜。 又’本發明的目的在提供能夠在真空氣氛中貼合在正 確位置上的光學低通濾波鏡之製造方法。 (3) (3)200424574 〔用以解決課題之手段〕 本發明人，爲了達成上述目的，用心檢討的結果，發 現在高分子薄膜兩面貼合硬質的第1雙折射板和第2雙折 射板時，需要先進行將高分子薄膜貼合在第1雙折射板之 第1貼合工程，再進行將高分子薄膜貼合在第2雙折射板 之第2貼合工程之兩次貼合工程之事實；以及在將高分子 薄膜貼合在第1雙折射板之第1貼合工程中，藉由將高分 子薄膜例如以滾輪等一邊擠出氣泡一邊貼合，即使在大氣 中也不會有氣泡跑入之事實；以及在硬質板彼此貼合之第 2貼合工程中必須要在真空氣氛下進行之事實；以及真空 氣氛理想爲5 00Pa〜1 Pa之事實；以及藉由令第2貼合工 程在真空氣氛下進行，除了可提升製造良率，還可使生產 效率的下降收斂在最小限度之事實。 在真空氣氛進行之第2貼合工程中，是將貼合有第1 雙折射板的高分子薄膜，和第2雙折射板彼此離間而呈面 對面配置，使其在真空氣氛下後，令高分子薄膜和第2雙 折射板彼此接近，將它們壓著，藉此可使硬質板在真空氣 氛下不存在氣泡而彼此貼合。 又’以第2貼合工程，將貼合有第1貼合工程的高分 子薄膜和第2雙折射板於真空氣氛中進行正確位置貼合的 方法’可以採用如下的方法：令貼合有高分子薄膜的第1 雙折射板或第2雙折射板之一方，被保持在上下升降且常 時往上方彈撥的誘導裝置上，再令其與被配置在位於其下 方之下側壓著板上的第1雙折射板或第2雙折射板之另一 (4) (4)200424574 方彼此離間而令高分子薄膜和第2雙折射板呈面對面配置 後，令上側壓著板降下而使被保持在誘導裝置內的第1雙 折射板或第2雙折射板之一方抵抗誘導裝置之彈撥力而降 下，藉由上側壓著板使得高分子薄膜和第2雙折射板彼此 接近，而使第1雙折射板、高分子薄膜以及第2雙折射板 在上側壓著板和下側壓著板之間夾緊壓著。 又，使用黏著劑貼合時，藉由在壓著中增加加溫，可 使其更爲強固地貼著。 此時，加溫的溫度理想範圍是30°C〜80°C。 因此，藉由在經過加熱的壓著板之間夾緊壓著，可使 其更爲強固地貼著。 此時，壓著之加壓力理想範圍係 1 9 6 9 6 0 0 P a〜 4596000Pa ° 又，藉由一邊加熱一邊加壓，可使其更爲強固地貼著 〇 又，藉由在壓著板和雙折射板之間夾著緩衝材而一邊 加熱一邊加壓，緩衝材可以吸收雙折射板或高分子薄膜的 微小凹凸，而能均勻地加壓。藉此，可使雙折射板和高分 子薄膜強固地貼合。 因此，第1發明係提供一種屬於在硬質的第1雙折射 板和硬質的第2雙折射板之間，夾著高分子薄膜（fiim ) 而成的光學低通濾波鏡之製造方法，其特徵爲，具有：將 前記第1雙折射板貼合在前記高分子薄膜之第1貼合工程 ;及在第1貼合工程後，在真空氣氛下將前記第2雙折射 -8- (5) 200424574 板壓著至前記高分子薄膜上的第2貼合工程。 第2發明係提供〜種在第1發明之光學低通濾波 製造方法中，前記第2貼合工程，是在真空氣氛下， 貼合有則記局分子溥膜的則記第1雙折射板和前記第 折射板彼此離間而令前記高分子薄膜和前記第2雙折 呈面對面配置後’再令前記高分子薄膜和前記第2雙 板彼此接近，將它們進行壓著。 第3發明係提供一種在第1發明之光學低通濾波 製造方法中，前記第2貼合工程是在真空氣氛下，令 有前記高分子薄膜的前記第1雙折射板或第2雙折射 一方，被保持在上下升降且常時往上方彈撥的誘導裝 ，再令其與被配置在位於其下方之下側壓著板上的前 1雙折射板或前記第2雙折射板之另一方彼此離間而 記高分子薄膜和前記第2雙折射板呈面對面配置後， 側壓著板降下而使被保持在前記誘導裝置內的前記第 折射板或第2雙折射板之一方抵抗前記誘導裝置之彈 而降下，藉由前記上側壓著板使得前記高分子薄膜和 第2雙折射板彼此接近，而使前記第1雙折射板、前 分子薄膜以及前記第2雙折射板在前記上側壓著板和 下側壓著板之間夾緊壓著。 第4發明係提供一種在第1〜3發明之任一光學 濾波鏡之製造方法中，前記第2貼合工程是在已加熱 下壓著板之間夾緊壓著。 第5發明係提供一種在第1發明之光學低通濾波 鏡之 先令 2雙 射板 折射 鏡之 貼合 板之 置上 記第 令前 令上 1雙 撥力 前記 記局 前記 低通 的上 鏡之 -9- (6) (6)200424574 製造方法中，前記第】貼合工程’是在真空氣氛下將前記 第1雙折射板壓著至前記高分子薄膜。 第6發明係提供一種在第1〜5發明之任一光學低通 濾波鏡之製造方法中，具有：對前記第2貼合工程所製造 的光學低通濾波鏡一邊加熱一邊施加壓力之加壓處理工程 〇 第7發明係提供一種在第1〜6發明之任一光學低通 濾波鏡之製造方法中’前記真空氣氛係在50〇pa至1 Pa之 範圍內。 第8發明係提供一種在第1〜6發明之任一光學低通 濾波鏡之製造方法中’前記壓著的加壓力是在1 9696 OOPa 至4596000Pa之範圍內。 第9發明係提供一種在第4發明之光學低通濾波鏡之 製造方法中，前記第2貼合工程中的加熱溫度是在3 (TC 至8 0 °C之範圍內。 第1 〇發明係提供一種在第1〜6發明之任一光學低通 濾波鏡之製造方法中，在前記第1貼合工程後，在真空氣 氛下將前記第2雙折射板壓著至前記高分子薄膜的第2貼 合工程中，在下側壓著板和雙折射板之間，或/及在上側 壓著板和雙折射板之間，夾著緩衝材而進行壓著。 【實施方式】 以下將就本發明之光學低通濾波鏡之製造方法的實施 形態加以說明，但是本發明並非侷限於以下實施形態。 -10- (7) (7)200424574 本發明之光學低通濾波鏡之製造方法的對象之光學低 通濾波鏡，可舉出2片雙折射板間夾著由高分子薄膜所成 之1 / 4波長板之構造的垂直附加型的3層構造爲例子。 雙折射板，一般係採用具有所定之結晶面的水晶板。構成 1 / 4波長板的高分子薄膜，可舉例如經過一軸延伸的塑 膠薄膜（plastic film ) 。1 / 4波長板係具有將入射光的 偏光狀態從直線偏光轉換成圓偏光之機能。經過一軸延伸 之所定厚度的高分子薄膜，具有入射光波長越大則雙折射 率越大之特性。經過一軸延伸之高分子薄膜，例如，爲厚 度約80/zm的塑膠薄膜。這些雙折射板和高分子薄膜是 需要以使各光學軸朝向所定方向的方式而將彼此予以精密 配置。 爲了將雙折射板貼合至高分子薄膜的兩面，會使用黏 著劑或接著劑。接著劑一般選擇生產效率佳的紫外線硬化 型。黏著劑則選擇透光性良好的類型，有時會在高分子薄 膜的兩面形成20 左右的黏著劑層，以雙面膠帶的形 態來供給。又，亦有只在高分子薄膜的單面形成黏著劑層 t情形。該高分子薄膜在未設黏著劑層的面係藉由接著劑 而接著。 圖1係光學低通濾波鏡之主要製造工程的流程圖。 該光學低通濾波鏡之製造工程，係分爲使用已經形成 有紅外線遮斷膜和反射防止膜的第1雙折射板和第2雙折 射板而進行貼合之情形，和在貼合後才形成紅外線遮斷膜 和反射防止膜之情形。使用已經形成有紅外線遮斷膜和反 -11 - (8) (8)200424574 射防止膜的第1雙折射板和第2雙折射板而進行貼合之情 形，係在第1雙折射板及第2雙折射板之各別之外側面的 單面，分別進行紅外線遮斷膜和反射防止膜的成膜工程。 由於一旦紅外線遮斷膜成膜，則雙折射板會有發生彎曲的 情形，因此以在進行貼合後’才形成紅外線遮斷膜和反射 防止膜者爲理想。 一般的工程，係在第1雙折射板上貼合高分子薄膜之 第1貼合工程後，進行已經貼合於第1雙折射板上的高分 子薄膜貼合至第2雙折射板的第2貼合工程以製造3層構 造之光學低通濾波鏡。之後，因應需要，而對光學低通濾 波鏡一邊加溫一邊加壓，進行使貼合更強固的加壓處理工 程。其次，按照需要，進行在光學低通濾波鏡之其中一面 上形成紅外線遮斷濾波鏡的紅外線遮斷膜成膜工程，及在 光學低通濾波鏡之另一面上形成反射防止膜之反射防止膜 成膜工程，除了對光學低通濾波鏡附加紅外線遮斷之機能 ，還附加了減少反射並提升光線穿透率的機能。最後，進 行切斷成光學低通濾波鏡所需的大小的切斷工程，之後經 過檢查工程、捆包工程而最終就以光學低通濾波鏡的成品 出貨。 第1貼合工程之第1雙折射板上貼合高分子薄膜的方 法，由於雙折射板係硬質的水晶板，高分子薄膜是軟質’ 因此藉由將高分子薄膜對水晶板以滾輪將氣泡擠壓出來而 貼合，就可在大氣中進行貼合。又’雖然會降低生產效率 ，但第1貼合工程亦可在真空氣氛中進行。 -12- (9) (9)200424574 將，貼合有第1雙折射板的高分子薄膜，貼合至第2雙 折射板的第2貼合工程中，爲了要使硬質板彼此貼合，需 要在真空氣氛下進行貼合。 圖2 ( a )係第1貼合工程和第2貼合工程兩者均可 使用之真空貼合裝置的槪要構成之側面透視圖。 圖2(b)是誘導裝置的放大圖，圖2(c)係進行貼 合之際第1雙折射板和高分子薄膜的重疊位置關係的平面 圖’圖2 ( d )係真空貼合裝置正在進行壓著動作之狀態 的側面圖。 該真空貼合裝置100，係如圖2(a)所示，具備真空 處理室110，以真空配管111連接至未圖示的真空裝置， 而可抽成真空。真空處理室110內之底面的上面，配置著 已經平滑處理過之平整的固定盤也就是下側壓著板1 2 1。 下側壓著板1 2 1係大於第1雙折射板1，在載置第1雙折 射1板時’將第1雙折射板1整體保持而周圍還留有充分 大小的面積。下側壓著板1 2 1的兩端部側上配設有貫通下 側壓著板1 2 1而可上下升降的誘導裝置1 3 0。 該誘導裝置130，如圖2(b)的放大圖所示，被保持 成可在下側壓著板121垂直方向上升降的升降針腳131的 上端處，設有針狀金屬朝外面呈L字狀曲折而成之形狀的 誘導保持部132。該誘導保持部132，除了可將矩陣狀的 第1雙折射板1之短邊1 1之兩端緣予以保持，還規定了 短邊1 1之兩側面距離兩側的位置。升降針腳1 3 1係藉由 彈性構件1 3 3而往上方彈撥，平常誘導保持部1 3 2是在下 -13- (10) (10)200424574 側壓著板1 2 1上面的上方保持離間。藉由將第1雙折射板 1保持於該誘導保持部1 3 2上，可使第1雙折射板丨被保 持在空中。升降針腳131係藉由垂直向下的壓下，而抵抗 彈性構件1 3 3的彈撥力，一直下降到使被誘導保持部1 3 2 所保持的第1雙折射板1接觸至下側壓著板〗2 1的上面的 位置。彈性構件1 3 3的構成，除了圖示的線圈狀彈簧以外 ’還可舉例有板簧、流體彈簧等彈簧或橡膠等彈性體。 高分子薄膜2的寬度，如圖2(c)所示，是被形成 爲只略小於第1雙折射板1的長度，且只略小於兩側之升 降針腳1 3 1之間的離間距離。因此，如圖2 ( b )所示， 可將高分子薄膜2載置於升降針腳1 3 1間之下側壓著板 121 上。 配置一貫穿真空處理室110的上壁藉由未圖示之驅動 裝置而在垂直方向上升降驅動之升降軸 141，升降軸 141 的下端則固定有上側壓著板1 42。該上側壓著板1 42的下 面，係和下側壓著板1 2 1的上面平行，而且被處理成平滑 。上側壓著板1 42，係和下側壓著板1 2 1幾乎相同的形狀 ，且是能夠覆蓋第1雙折射板1之整體的形狀、大小。上 側壓著板1 42的驅動，係令上側壓著板1 42下降時，可以 到達抵觸下側壓著板1 2 1之上面而能夠加壓之位置爲止。 使用此種真空貼合裝置1 00，參照圖2來說明令第1 貼合工程在真空氣氛下進行的方法。此時的高分子薄膜2 ，係假設使用兩面已經設置黏著劑層之類型來說明。 第1雙折射板1和第2雙折射板3是使用事先以洗淨 •14- (11) (11)200424574 工程洗淨之，已經去除了表面附著物者。首先，打開真空 處理室110之未圖示的門而將已經讓一面的黏著劑層露出 之高分子薄膜2，令露出之黏著劑層爲上而載置於下側壓 著板1 2 1上的所定位置。其次，將第1雙折射板1載置於 誘導裝置1 3 0的誘導保持部1 3 2上。藉此，第1雙折射板 1和高分子薄膜2的配置，成爲了如圖2 ( c )所示的重疊 配置。亦即，由上來看，第1雙折射板1的短邊11側之 兩端緣是從高分子薄膜2之兩端緣往外伸出。第1雙折射 板1的短邊1 1側的兩端緣是被誘導裝置1 3 0的誘導保持 部1 3 2所保持，第！雙折射板1則被保持在高分子薄膜2 上方的空間中，和高分子薄膜2彼此離間而面對面配置。 其次，將真空處理室1 1 〇之未圖示的門關閉，令未圖 示之真空裝置作動，透過真空配管111將真空處理室110 內抽成真空。真空處理室1 1 0內到達所定真空度後，以未 圖示之驅動裝置驅動升降軸141而使其下降。升降軸141 下降，上側壓著板142下降而抵觸誘導保持部132的上端 ，上側壓著板1 42便抵抗使升降針腳1 3 1往上方彈撥的彈 性構件1 3 3的彈撥力而將誘導保持部1 3 2 —起下推而下降 ，使得被誘導保持部1 3 2保持的第1雙折射板1抵觸至載 置於下側壓著板1 2 1上的高分子薄膜2後，上側壓著板 1 42會以所定的壓力將第1雙折射板1推壓。藉此，如圖 2 ( d )所示，上側壓著板1 42和下側壓著板1 2 1之間，夾 著第1雙折射板1及高分子薄膜2而以所定的壓力壓著。 此時第1雙折射板1和高分子薄膜2之重疊會保持圖2 ( -15- (12) (12)200424574 c )所示的配置。經過所定時間壓著後，驅動未圖示之驅 動裝置而使升降軸1 4 1上升，令上側壓著板丨4 2上升。伴 隨上側壓著板1 4 2的上升，誘導保持部1 3 2受到彈性構件 1 3 3的彈撥力而將貼合在局分子薄膜2的第1雙折射板1 予以保持的狀態下上升，回到原來的位置。 其次，將真空處理室110之真空配管111遮斷，將大 氣導入真空處理室110內，使其回到大氣壓力而結束第1 貼合工程。 其次，一邊參照圖3 —邊說明使用真空貼合裝置100 進行第2貼合工程之方法。圖3 ( a )係第1雙折射板1、 高分子薄膜2及第2雙折射板3之重疊狀態說明圖，圖3 (b )係設置在真空貼合裝置上之狀態的剖面圖，圖3 ( c )係表示壓著狀態的剖面圖。 首先，打開真空處理室1 1 〇之未圖示的門，將貼合有 高分子薄膜2的第1雙折射板1取出，如圖3 ( b )所示 ，在下側壓著板1 2 1的上面所定位置處載置第2雙折射板 3。令高分子薄膜2的另一面黏著劑層露出，令露出的黏 著劑層爲下而將第1雙折射板1再度被誘導裝置130的誘 導保持部1 3 2所保持。此時，第1雙折射板1、高分子薄 膜2及第2雙折射板3的垂直方向層疊，係如圖3(a) 所示，矩形狀的第1雙折射板1和同爲矩形狀的高分子薄 膜2及第2雙折射板3係成直交配置，第2雙折射板3的 紙面左右方向之寬度係窄於同方向上高分子薄膜2的寬度 。被載置於下側壓著板1 2 1上的第2雙折射板3，和貼合 -16- (13) (13)200424574 至被誘導保持部1 3 2所保持的第1雙折射板1的高分子薄 膜2，是成彼此離間而面對面配置。 在圖3 ( b )所示的配置狀態下，透過真空配管丨！ i 將真空處理室1 1 0內抽成真空，到達所定真空度後，以未 圖示之驅動裝置驅動升降軸1 4 1而使其下降，上側壓著板 1 4 2逐漸下降而抵觸誘導保持部1 3 2的上端，上側壓著板 1 4 2便抵抗使升降針腳1 3 1往上方彈撥的彈性構件；! 3 3的 彈撥力而將誘導保持部1 3 2 —起下推而下降，使得被誘導 保持部1 3 2保持的貼合有第1雙折射板1的高分子薄膜2 ，抵觸至載置於下側壓著板1 2 1上的第2雙折射板3後， 上側壓著板1 4 2會以所定的壓力將第1雙折射板丨推壓。 藉此，如圖3 ( c )所示，上側壓著板14 2和下側壓 著板1 21之間，夾著第1雙折射板1、高分子薄膜2及第 2雙折射板3而以所定的壓力壓著。 經過所定時間壓著後，驅動未圖示之驅動裝置而使升 降軸1 4 1上升，令上側壓著板1 4 2上升。伴隨上側壓著板 1 42的上升，誘導保持部1 3 2受到彈性構件；[3 3的彈撥力 ’而將在高分子薄膜2上貼合有第2雙折射板3的第1雙 折射板1予以保持的狀態下上升，回到原來的位置。其次 ’將真空配管111關閉’將大氣導入真空處理室110內， 使其回到大氣壓力，將真空處理室110之未圖示的門打開 ’而將在局分子薄膜2兩面貼有第1雙折射板1及第2雙 折射板3的光學低通濾波鏡取出。 此種使用真空貼合裝置100而在高分子薄膜2兩面貼 -17- (14) (14)200424574 合第1雙折射板1及第2雙折射板3的方法，由於是在真 空氣氛中進行貼合，因此高分子薄膜2及雙折射板1、3 之間可確實防止有氣泡存在。 又’藉由將第i雙折射板！載置於誘導裝置1 3 0的誘 導保持部1 3 2，可決定第丨雙折射板1的位置，以被誘導 保持部1 3 2保持的狀態而藉由上側壓著板：[42將誘導保持 部1 3 2垂直推下，第丨雙折射板1會下降，而和配置於下 方之下側壓著板121之上所定位置之高分子薄膜2或第2 雙折射板3以所定的正確位置重疊，壓著之。因此，第1 雙折射板1、高分子薄膜2及第2雙折射板3的光學軸在 真空氣氛中可分別正確地配置而以良好的精確度進行貼合 〇 上記第2貼合工程的說明中，雖然是將第1雙折射板 1保持在誘導保持部1 3 2上，但亦可將第2雙折射板3保 持在誘導保持部1 3 2上，令貼合有高分子薄膜2的第1雙 折射板1載置於下側壓著板1 2 1上。 又，上記說明中，雖然第1貼合工程和第2貼合工程 兩者均使用真空貼合裝置1〇〇而進行，但在本發明中，由 於第1貼合工程不必在真空氣氛下進行即可完成，因此只 有第2貼合工程在真空氣氛中進行的話，在生產效率面上 比較理想。 又，雖然使用兩面設有黏著劑層的高分子薄膜爲例來 說明，但亦可使用接著劑。此時’爲了促進紫外線硬化， 上側壓著板I 42和下側壓著板1 2 1 ’是以能夠透過紫外線 -18· (15) (15)200424574 的玻璃等來構成者較爲理想，紫外線照射燈亦設於真空處 理室1 1 0者較爲理想。又，亦須設有塗佈接著劑的前期工 程。 又’如圖4所示，在以黏著劑貼合時，理想爲上側壓 著板1 42和下側壓著板丨2丨內分別內藏有電熱加熱器等加 熱手段1 5 0。藉由在壓著時對黏著劑以加熱手段加熱，可 使黏著劑軟化而消除表面的凹凸，可使黏著劑的貼合更爲 強固。 甚至’發明人針封雙折射板和局分子薄膜的貼合條件 ’也就是真空氣氛（真空度）、加熱溫度（貼合溫度）、 壓著壓力進行實驗，找出了可減少雙折射板和高分子薄膜 貼合面中的氣泡、提升製造良率的良好條件。以下將進行 此部份的說明。 表1係將雙折射板和高分子薄膜貼合時，對於真空度 變化之貼合面中所殘留之氣泡的面積進行測量的結果。氣 泡面積係複雜的形狀，爲了方便起見，是以氣泡的較長方 向的寸法，和與該較長方向之長度的近似垂直方向的寸法 ，兩者之積視爲其面積。 又’試料是使用大小爲50mmx50mm，厚度0.7mm的 雙折射板，和兩面形成有丙烯酸酯系的黏著劑層（厚度約 2〇//m)的聚碳酸酯爲素材而成的高分子薄膜（厚度約8〇 y m ) 〇 其他的貼合條件有，貼合溫度4 0 °C、壓著家壓力 1 9 600 OPa、壓著時間3分鐘。此外，貼合溫度，係指陣型 -19- (16) (16)200424574 貼合時雙折射板和高分子薄膜的溫度。 表1〕 真空度 氣泡面積（m m -) ___-—- (Pa) 試料1 試料2 1 0000 30 35 36 5 000 25 23 27 1000 10 6 12 500 0 0 0 100 0 0 0 50 0 0 0 1 0 0 0 ____—— 根據該結果’當真空度在500Pa〜IPa的範_內，貝占 合面內不存在氣泡，而得良好的貼合條件。 其次，使用和前述實驗相同的手法，且用相同的試料 ，令貼合溫度變化時，計測貼合面所殘留的氣泡面積之結 果如表2所示。 -20- (17) 200424574 〔表2〕 貼合溫度 氣泡面積（m m2) (Pa) 試料1 試料2 試料3 25 3 0 5 30 0 0 0 40 0 0 0 50 0 0 0 60 0 0 0 70 0 0 0 80 0 0 0 90 13 16 7 100 11 14 18 根據該結果，當貼合溫度在3 0 °C〜8 0 °C之範圍內， 貼合面內不存在氣泡，而得良好的貼合條件。 甚至，使用和前述實驗相同的試料，令壓著之加壓力 變化時，計測貼合面所殘留的氣泡面積之結果如表3所示 -21 - (18) 200424574 〔表3〕 加壓力 氣泡面積（mm2) (Pa) 試料1 試料2 試料3 328200 30 42 54 656400 9 5 13 1969600 0 0 0 3282800 0 0 0 3920000 0 0 0 45 96000 0 0 0 根據該結果，當壓著的加壓力在 1 969600Pa〜 4 5 96000Pa之範圍內，貼合面內不存在氣泡，而得良好的 貼合條件。 其次，使用真空貼合裝置進行第2貼合工程時，關於 其他實施形態，將參照圖5來說明。圖5 ( a )係說明第1 雙折射板1、局分子薄膜2及第2雙折射板3之層疊狀態 的平面圖，圖5 ( b )係載置於真空貼合裝置上狀態的剖 面圖，圖5 ( c )係正在壓著狀態的剖面圖。 首先，如圖5 ( b )所示，在下側壓著板1 2 1的上面 配置有緩衝材5，緩衝材5上的所定位置處載置著第2雙 折射板3。此外，緩衝材5的材質有矽橡膠等橡膠片、聚 丙嫌、聚乙儲板、尿院等發泡品或樹脂片、或是上質紙、 影印紙、瓦楞紙、防塵紙等紙類、木棉、耐綸等纖維類、 -22- (19) (19)200424574 牛皮等皮革類等，從這些較金屬還要柔軟的材質當中選擇 而爲之。 其次，令貼合有高分子薄膜2的第1雙折射板1之高 分子薄膜2的另一面黏著劑層露出，令露出的黏著劑層爲 下而將第1雙折射板1再度被誘導裝置130的誘導保持部 1 3 2所保持。此時，第1雙折射板1、高分子薄膜2及第 2雙折射板3的垂直方向層疊，係如圖5 ( a )所示，矩形 狀的第1雙折射板1和同爲矩形狀的高分子薄膜2及第2 雙折射板3係成直交配置，第2雙折射板3的紙面左右方 向之寬度係窄於同方向上高分子薄膜2的寬度。被載置於 下側壓著板1 2 1上的第2雙折射板3，和貼合至被誘導保 持部1 3 2所保持的第1雙折射板1的高分子薄膜2，是成 彼此離間而面對面配置。 在圖5 ( b )所示的配置狀態下，透過真空配管ill 將真空處理室110內抽成真空，到達所定真空度後，以未 圖示之驅動裝置驅動升降軸1 4 1而使其下降，上側壓著板 1 42逐漸下降而抵觸誘導保持部1 3 2的上端，上側壓著板 1 42便抵抗使升降針腳1 3 1往上方彈撥的彈性構件]3 3的 彈撥力而將誘導保持部132 —起下推而下降，使得被誘導 保持部1 32保持的貼合有第1雙折射板1的高分子薄膜2 ，抵觸至載置於下側壓著板1 2 1上的第2雙折射板3後， 上側壓著板1 42會以所定的壓力將第1雙折射板1推壓。 藉此，如圖5 ( c )所示，上側壓著板14 2和下側壓 著板121之間，夾著第1雙折射板1、高分子薄膜2及第 -23- (20) (20)200424574 2雙折射板3而以所定的壓力壓著。 經過所定時間壓著後，驅動未圖示之驅動裝置而使升 降軸1 4 1上升’令上側壓著板1 4 2上升。伴隨上側壓著板 1 4 2的上升，誘導保持部1 3 2受到彈性構件；[3 3的彈撥力 ，而將在高分子薄膜2上貼合有第2雙折射板3的第1雙 折射板1予以保持的狀態下上升，回到原來的位置。其次 ，將真空配管1 1 1關閉，將大氣導入真空處理室1 1 〇內， 使其回到大氣壓力，將真空處理室1 1 〇之未圖示的門打開 ，而將在高分子薄膜2兩面貼有第1雙折射板1及第2雙 折射板3的光學低通濾波鏡取出。 在此，說明將緩衝材5夾在第2雙折射板3及下側壓 著板1 2 1之間進行貼合的效果。 發明人藉由實驗，比較了第2雙折射板3和下側壓著 板1 2 1間配置有緩衝材5之情況和未配置之情況下，貼合 面所殘留的氣泡。 表4係上記構成中將雙折射板和高分子薄膜貼合，並 使壓著時間變化時，貼合面中所殘留之氣泡的面積進行測 量的結果。氣泡面積係複雜的形狀，爲了方便起見，是以 氣泡的較長方向的寸法，和與該較長方向之長度的近似垂 直方向的寸法，兩者之積視爲其面積。 又，試料是使用大小爲50mmx50mm，厚度的 雙折射板，和兩面形成有丙烯酸酯系的黏著劑層（厚度約 20// m)的聚碳酸酯爲素材而成的高分子薄膜（厚度約80 β m )。 -24- (21) 200424574 其他的貼合條件有’貼合溫度4 0 C、壓著家壓力 196000Pa、壓著時間3分鐘。 〔表4〕 壓著時 氣泡面積（m m 2) 間（分） 每緩衝材 無緩衝材 試料1 試料2 試料3 試料4 試料5 試料6 0.1 10 6 13 33 52 47 0.5 0 0 0 20 23 36 1.0 0 0 0 10 1 5 12 3.0 0 0 0 0 0 0 5.0 0 0 0 0 0 0 10.0 0 0 0 0 0 0200424574 (1) 发明 Description of the invention [Technical field to which the invention belongs] The present invention relates to a method for manufacturing an optical low-pass filter, and particularly to improving the optical low-pass virtue of a structure in which a polymer film is sandwiched by a birefringent plate. 1¾ manufacturing yield technology. [Prior art] Transgastric in imaging devices such as digital still cameras or digital video cameras uses imaging devices such as C CD or CMOS. This imaging element converts optical images into electrical signals by arranging pixels arranged in a matrix with a predetermined gap, and g @ images are photographed. In such an imaging device, the spatial frequency of the optical image is ~ 1/2 of the sampling frequency determined by the pixel-dominated column gap, and a pseudo-like signal such as a moire may occur and the image quality may be degraded. Therefore, in a general imaging device, an optical low-pass filter that suppresses high-frequency components of the spatial frequency of the optical image is provided in front of the imaging element. The structure of the optical low-pass filter is generally a three-type birefringent plate type and a phase plate type sandwiched between the two birefringent plates, and a 1/4 wavelength sandwiched between the two type birefringent plates. High performance such as the vertical attachment type of the plate structure is known. In recent years, it has been proposed to use a polymer film formed by a uniaxial stretching method as a 1/4 wavelength plate. By using a polymer film, the purpose of thinning and reducing the manufacturing cost can be achieved. A birefringent plate uses a crystal plate. When manufacturing an optical low-pass filter with a polymer film sandwiched between two crystal plates, it is necessary to use adhesives on both sides of the polymer film or connect -5- (2) (2) 200424574 The project of laminating crystal plates. When the polymer film is bonded to the crystal plate, bubbles may run between the polymer film and the crystal plate. It cannot be used as an optical element due to the presence of air bubbles, which is a cause of failure and causes a decrease in manufacturing yield. When the crystal plates are bonded to each other, a technique for preventing bubbles from running in by bonding them in a vacuum atmosphere is disclosed in, for example, Patent Document 1 below. [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-29035 [Summary of the Invention] [Problems to be Solved by the Invention] However, although pressing is performed in a vacuum atmosphere, bubbles do not remain, and the manufacturing yield can be improved. However, it takes time to decrease from atmospheric pressure to vacuum, resulting in low production efficiency. Therefore, it is necessary to minimize the engineering limit in a vacuum atmosphere to avoid a decline in production efficiency. In addition, when the optical low-pass filter is manufactured, the respective optical axes of the two birefringent plates and the high-molecular film must be correctly arranged, so it is required to be attached to the correct position in a vacuum atmosphere. The present invention has been made in view of the foregoing circumstances, and an object thereof is to provide a method for manufacturing an optical low-pass filter with high production efficiency. Laminated polymer film. It is another object of the present invention to provide a method for manufacturing an optical low-pass filter that can be bonded to a correct position in a vacuum atmosphere. (3) (3) 200424574 [Means to solve the problem] In order to achieve the above purpose, as a result of careful review, the inventor found that a rigid first birefringent plate and a second birefringent plate were bonded to both sides of the polymer film. In this case, it is necessary to perform the first laminating process of laminating the polymer film on the first birefringent plate, and then perform the two laminating processes of the second laminating process of laminating the polymer film to the second birefringent plate. Facts; and in the first bonding process of bonding a polymer film to a first birefringent plate, the polymer film is bonded together by squeezing air bubbles, for example, with a roller, etc. The fact that there are bubbles running in; and the fact that the second bonding process of bonding the hard boards to each other must be performed in a vacuum atmosphere; and the fact that the vacuum atmosphere is ideally 5000 Pa to 1 Pa; and The lamination process is carried out in a vacuum atmosphere, in addition to improving the manufacturing yield, and the fact that the reduction in production efficiency can be minimized. In the second bonding process performed in a vacuum atmosphere, the polymer film to which the first birefringent plate is bonded and the second birefringent plate are spaced apart from each other and are disposed face to face. The molecular film and the second birefringent plate are brought close to each other, and they are pressed against each other, whereby the hard plate can be bonded to each other without bubbles in a vacuum atmosphere. Also, "the second bonding process, the method of bonding the polymer film and the second birefringent plate bonded to the first bonding process in a vacuum atmosphere at the correct position" can be used as follows: One of the first birefringent plate or the second birefringent plate of the polymer film is held on an induction device that is vertically moved up and down and is constantly popped upward, and then it is arranged on a pressing plate disposed below and below it After the first birefringent plate or the second birefringent plate of the other (4) (4) 200424574 are separated from each other and the polymer film and the second birefringent plate are arranged face to face, the upper pressing plate is lowered and the substrate is pressed. One of the first birefringent plate or the second birefringent plate held in the induction device is lowered against the plucking force of the induction device, and the polymer film and the second birefringent plate are brought closer to each other by pressing the plate on the upper side, so that the first The 1 birefringent plate, the polymer film, and the second birefringent plate are clamped between the upper pressure plate and the lower pressure plate. In addition, when bonding using an adhesive, it is possible to make the bonding stronger by increasing the heating during pressing. At this time, the ideal temperature range is 30 ° C ~ 80 ° C. Therefore, it can be more firmly attached by clamping and pressing between the heated pressing plates. At this time, the ideal range of the pressing pressure is 1 9 6 9 6 0 0 Pa ~ 4596000 Pa °. By applying pressure while heating, it can be more firmly adhered to it. A buffer material is sandwiched between the plate and the birefringent plate, and the pressure is applied while heating. The buffer material can absorb the minute irregularities of the birefringent plate or the polymer film, and can evenly press. Thereby, the birefringent plate and the high-molecular film can be firmly bonded. Therefore, the first invention provides a method for manufacturing an optical low-pass filter, which is formed by sandwiching a polymer film (fiim) between a rigid first birefringent plate and a rigid second birefringent plate. In order to have the first laminating process of laminating the first birefringent plate of the preface to the polymer film of the preface, and after the first laminating process, the second birefringence of the preface -8- (5) 200424574 The second bonding process of pressing the board to the polymer film mentioned above. The second invention is to provide the first birefringent plate in the method of manufacturing the optical low-pass filter according to the first invention, wherein the second bonding process is described in the vacuum atmosphere, and the molecular bilayer film is bonded in a vacuum atmosphere. The pre-refractive film and the pre-reciprocal second birefringent plate are separated from each other so that the pre-reciprocal polymer film and the pre-second birefringent are arranged face to face, and then the pre-polymer film and the pre-second bi-plate are brought close to each other, and they are pressed together. The third invention provides a method for manufacturing an optical low-pass filter according to the first invention, wherein the second bonding process of the preamble is to make the prelude first birefringent plate or the second birefringence of the prepolymer having a prepolymer film under a vacuum atmosphere. , The induction device kept being lifted up and down and constantly poking upwards, and then separated from the other one of the first birefringent plate or the second birefringent plate of the previous birefringent plate that is arranged on the lower and lower pressing plate. However, after the polymer film and the second birefringent plate are placed face to face, the side pressure plate is lowered so that one of the first birefringent plate or the second birefringent plate held in the prescriptive induction device resists the bullet of the prescriptive induction device. While lowering, the prepress polymer film and the second birefringent plate are brought close to each other by the pre-pressing plate on the preface, so that the first birefringent plate, the premolecular film, and the second birefringent plate of the preface are pressed on the prepress plate and Clamping between the lower pressing plates. The fourth invention provides a method for manufacturing an optical filter according to any one of the first to third inventions, wherein the second bonding process described above is performed by clamping and pressing between the pressing plates under heating. The fifth invention is to provide a low-pass upper mirror of the shilling 2 of the optical low-pass filter of the first invention, the placement of the lamination plate of the double-lens refraction mirror, and the order of the low-pass. -9- (6) (6) 200424574 In the manufacturing method, the preface first] The bonding process is to press the first birefringent plate of the preface to the prepolymer polymer film in a vacuum atmosphere. The sixth invention provides a method for manufacturing an optical low-pass filter according to any one of the first to fifth inventions, comprising: applying pressure while heating and applying pressure to the optical low-pass filter manufactured in the second bonding process described above Treatment Engineering: The seventh invention provides a method for manufacturing an optical low-pass filter according to any one of the first to sixth inventions. The vacuum atmosphere in the foregoing is within a range of 50 Pa to 1 Pa. The eighth invention provides a method of manufacturing an optical low-pass filter according to any one of the first to sixth inventions, wherein the pre-pressing pressure is in the range of 1 696 OOPa to 4596000 Pa. The ninth invention provides a method for manufacturing an optical low-pass filter according to the fourth invention, wherein the heating temperature in the second bonding process mentioned above is in the range of 3 (TC to 80 ° C.) The tenth invention In the method for manufacturing an optical low-pass filter according to any one of the first to sixth inventions, the second birefringent plate of the foregoing is pressed to the first of the polymer film of the foregoing in a vacuum atmosphere after the first bonding process of the foregoing. 2 In the bonding process, a cushioning material is sandwiched between the lower pressing plate and the birefringent plate, and / or between the upper pressing plate and the birefringent plate. [Embodiment] The following will describe the original The embodiment of the manufacturing method of the optical low-pass filter of the present invention will be described, but the present invention is not limited to the following embodiments. -10- (7) (7) 200424574 The object of the manufacturing method of the optical low-pass filter of the present invention An example of an optical low-pass filter is a three-layer structure of a vertical addition type in which a 1/4 wavelength plate made of a polymer film is sandwiched between two birefringent plates. Generally, a birefringent plate is used. Crystal plate with a predetermined crystal surface. Make up a quarter wave The polymer film of the plate may be, for example, a plastic film extending through one axis. The 1/4 wavelength plate has the function of converting the polarization state of the incident light from linear polarization to circular polarization. The thickness of the predetermined thickness extending through the axis The polymer film has the characteristic that the larger the incident light wavelength is, the larger the birefringence is. The polymer film extended through one axis, for example, is a plastic film with a thickness of about 80 / zm. These birefringent plates and polymer films need to be Each optical axis is oriented in a predetermined direction to precisely arrange each other. In order to attach a birefringent plate to both sides of a polymer film, an adhesive or an adhesive is used. Generally, an ultraviolet curing type with high production efficiency is selected for the adhesive. Adhesion The adhesive is selected from the types with good light transmission. Sometimes, an adhesive layer of about 20 is formed on both sides of the polymer film, and it is supplied in the form of a double-sided tape. In addition, there is also adhesion only on one side of the polymer film. In the case of the adhesive layer t, the polymer film is adhered by an adhesive on the surface where the adhesive layer is not provided. Fig. 1 shows an optical low-pass filter. The flow chart of the manufacturing process. The manufacturing process of the optical low-pass filter is divided into a case where the first birefringent plate and the second birefringent plate are formed by using an infrared blocking film and an antireflection film. , And the situation where the infrared blocking film and anti-reflection film are formed only after bonding. Use the first birefringent plate and the first birefringent plate and In the case where two birefringent plates are bonded together, the film formation process of the infrared blocking film and the anti-reflection film is performed on one side of each of the outer surfaces of the first birefringent plate and the second birefringent plate, respectively. Once the infrared blocking film is formed, the birefringent plate may be warped. Therefore, it is desirable to form the infrared blocking film and the anti-reflection film only after bonding. A general process is a first bonding process of laminating a polymer film on a first birefringent plate, and then a first step of laminating a polymer film already bonded to the first birefringent plate to a second birefringent plate. 2 Laminating process to manufacture a 3-layer optical low-pass filter. After that, if necessary, the optical low-pass filter is heated while being pressurized to perform a pressurizing process for strengthening the bonding. Secondly, according to need, the infrared blocking film forming process of forming an infrared blocking filter on one side of the optical low-pass filter, and the reflection preventing film of forming a reflection preventing film on the other side of the optical low-pass filter In the film formation project, in addition to the infrared blocking function of the optical low-pass filter, a function of reducing reflection and improving light transmittance is also added. Finally, a cutting process of the size required for cutting into an optical low-pass filter is performed. After inspection and packing, the finished product is finally shipped as an optical low-pass filter. The first method of laminating polymer film on the first birefringent plate of the first laminating project. Since the birefringent plate is a hard crystal plate, the polymer film is soft. Squeeze out and attach, and then attach in the atmosphere. Although the production efficiency is lowered, the first bonding process may be performed in a vacuum atmosphere. -12- (9) (9) 200424574 In the second bonding process of bonding a polymer film with a first birefringent plate to a second birefringent plate, in order to bond the hard plates to each other, Lamination is required in a vacuum atmosphere. Fig. 2 (a) is a side perspective view of the main components of a vacuum bonding apparatus that can be used in both the first bonding process and the second bonding process. Fig. 2 (b) is an enlarged view of the induction device, and Fig. 2 (c) is a plan view of the overlapping positional relationship between the first birefringent plate and the polymer film when bonding is performed. Fig. 2 (d) is a vacuum bonding device A side view of a state where a pressing operation is performed. The vacuum bonding apparatus 100 includes a vacuum processing chamber 110 as shown in FIG. 2 (a), and is connected to a vacuum apparatus (not shown) through a vacuum pipe 111 so as to be evacuated. On the upper surface of the bottom surface in the vacuum processing chamber 110, a flat fixed plate that has been smoothed, that is, a lower pressure plate 1 2 1 is arranged. The lower pressing plate 1 2 1 is larger than the first birefringent plate 1, and when the first birefringent plate 1 is placed ', the first birefringent plate 1 is held as a whole with a sufficient area around it. An induction device 1 30 is provided on both end portions of the lower pressing plate 1 2 1 so as to be able to move up and down by penetrating the lower pressing plate 1 2 1. As shown in the enlarged view of FIG. 2 (b), the induction device 130 is held at the upper end of the lifting pin 131 that can be raised and lowered in the vertical direction of the lower pressing plate 121. A needle-like metal is provided in an L shape toward the outside. The zigzag-shaped induction holding portion 132. In addition to holding both ends of the short sides 11 of the matrix-like first birefringent plate 1, the induction holding portion 132 also defines the positions of the two sides of the short sides 1 1 away from both sides. The lifting pins 1 3 1 are pulled upwards by the elastic members 1 3 3, and the usual induction holding portion 1 3 2 is kept above the lower -13- (10) (10) 200424574 side pressing plate 1 2 1 to keep a distance. By holding the first birefringent plate 1 on the induction holding portion 1 3 2, the first birefringent plate 丨 can be held in the air. The lifting pins 131 resist the plucking force of the elastic member 1 3 3 by being pressed down vertically until the first birefringent plate 1 held by the induced holding portion 1 3 2 is brought into contact with the lower side and pressed. Board〗 2 1 The upper position. In addition to the coil spring shown in the figure, the elastic member 1 3 3 can be exemplified by a spring such as a plate spring or a fluid spring or an elastic body such as rubber. As shown in FIG. 2 (c), the width of the polymer film 2 is formed to be slightly smaller than the length of the first birefringent plate 1, and only slightly smaller than the distance between the lift pins 1 31 on both sides. Therefore, as shown in FIG. 2 (b), the polymer film 2 can be placed on the lower pressing plate 121 between the lifting pins 1 31. An elevating shaft 141 which is vertically driven by a driving device (not shown) penetrating the upper wall of the vacuum processing chamber 110 is arranged, and an upper pressure plate 142 is fixed to the lower end of the elevating shaft 141. The lower surface of the upper pressing plate 1 42 is parallel to the upper surface of the lower pressing plate 1 2 1 and is processed to be smooth. The upper pressure plate 1 42 is almost the same shape as the lower pressure plate 1 2 1 and has a shape and size that can cover the entire first birefringent plate 1. The driving of the upper pressure plate 1 42 is such that when the upper pressure plate 1 42 is lowered, it can reach a position where it can press against the upper surface of the lower pressure plate 1 2 1. Using such a vacuum bonding apparatus 100, the method of making a 1st bonding process in a vacuum atmosphere is demonstrated with reference to FIG. The polymer film 2 at this time is assumed to be a type in which an adhesive layer is provided on both sides. The first birefringent plate 1 and the second birefringent plate 3 are cleaned in advance by using • 14- (11) (11) 200424574 engineering, and the surface attachments have been removed. First, open the unillustrated door of the vacuum processing chamber 110 and expose the polymer film 2 on which the adhesive layer on one side has been exposed, so that the exposed adhesive layer is on top and placed on the lower pressure plate 1 2 1 The given position. Next, the first birefringent plate 1 is placed on the induction holding portion 1 32 of the induction device 130. Thereby, the arrangement of the first birefringent plate 1 and the polymer film 2 becomes an overlapping arrangement as shown in FIG. 2 (c). That is, from the above point of view, both end edges of the short side 11 side of the first birefringent plate 1 protrude outward from both end edges of the polymer film 2. Both ends of the short side 11 of the first birefringent plate 1 1 side are held by the induction holding portion 1 3 2 of the induction device 1 3 0, the first! The birefringent plate 1 is held in a space above the polymer film 2 and is spaced apart from the polymer film 2 to be disposed face to face. Next, the door (not shown) of the vacuum processing chamber 110 is closed, an unillustrated vacuum device is operated, and the vacuum processing chamber 110 is evacuated through the vacuum pipe 111. After reaching a predetermined vacuum degree in the vacuum processing chamber 110, the lifting shaft 141 is driven by a driving device (not shown) to lower it. The lifting shaft 141 is lowered, and the upper pressing plate 142 is lowered to abut the upper end of the induction holding portion 132. The upper pressing plate 1 42 resists the plucking force of the elastic member 1 3 3 which causes the lifting pins 1 3 1 to pop upward, and the induced holding is performed.部 1 3 2 —Push down and lower so that the first birefringent plate 1 held by the induced holding portion 1 3 2 abuts against the polymer film 2 placed on the lower pressing plate 1 2 1 and presses the upper side The landing plate 1 42 pushes the first birefringent plate 1 at a predetermined pressure. As a result, as shown in FIG. 2 (d), the first birefringent plate 1 and the polymer film 2 are sandwiched between the upper pressing plate 1 42 and the lower pressing plate 1 2 1 under a predetermined pressure. . At this time, the overlap of the first birefringent plate 1 and the polymer film 2 will maintain the arrangement shown in FIG. 2 (-15- (12) (12) 200424574 c). After a predetermined time of pressing, a driving device (not shown) is driven to raise the lifting shaft 1 4 1 to raise the upper pressing plate 4 2. As the upper pressure plate 1 4 2 rises, the induction holding portion 1 3 2 receives the plucking force of the elastic member 1 3 3 and rises while holding the first birefringent plate 1 attached to the local molecular film 2 and returns. To the original position. Next, the vacuum piping 111 of the vacuum processing chamber 110 is shut off, the atmosphere is introduced into the vacuum processing chamber 110, and it is returned to atmospheric pressure to complete the first bonding process. Next, a method of performing the second bonding process using the vacuum bonding apparatus 100 will be described with reference to FIG. 3. Fig. 3 (a) is an explanatory view of the overlapping state of the first birefringent plate 1, the polymer film 2 and the second birefringent plate 3, and Fig. 3 (b) is a cross-sectional view of a state where it is installed on a vacuum bonding device. 3 (c) is a cross-sectional view showing a pressed state. First, open the unillustrated door of the vacuum processing chamber 1 1 0 and take out the first birefringent plate 1 to which the polymer film 2 is bonded, as shown in FIG. 3 (b), and press the plate 1 2 1 on the lower side. The second birefringent plate 3 is placed at the predetermined position above. The adhesive layer on the other side of the polymer film 2 is exposed, the exposed adhesive layer is downward, and the first birefringent plate 1 is held again by the induction holding portion 1 3 2 of the induction device 130. At this time, the first birefringent plate 1, the polymer film 2, and the second birefringent plate 3 are stacked in a vertical direction. As shown in FIG. 3 (a), the rectangular first birefringent plate 1 and the rectangular birefringent plate 1 are both rectangular. The polymer film 2 and the second birefringent plate 3 are arranged orthogonally, and the width of the paper surface of the second birefringent plate 3 in the left-right direction is narrower than the width of the polymer film 2 in the same direction. The second birefringent plate 3 placed on the lower pressing plate 1 2 1 and the first birefringent plate held by the -16- (13) (13) 200424574 to the induced holding portion 1 3 2 The polymer film 2 of 1 is disposed so as to face each other apart from each other. In the arrangement shown in Fig. 3 (b), the vacuum piping is transmitted! i The vacuum processing chamber 1 10 is evacuated to a predetermined degree of vacuum, and the lifting shaft 1 4 1 is driven by a driving device (not shown) to lower it, and the upper pressing plate 1 4 2 is gradually lowered to induce induction and maintenance. At the upper end of the section 1 3 2, the upper pressing plate 1 4 2 resists the elastic member that causes the lifting pins 1 3 1 to pop upward;! 3 3's plucking force will push the holding section 1 3 2 down and push down, The polymer film 2 bonded to the first birefringent plate 1 held by the induced holding portion 1 3 2 is caused to abut against the second birefringent plate 3 placed on the lower pressing plate 1 2 1 and press the upper side. The landing plate 1 4 2 pushes the first birefringent plate 丨 with a predetermined pressure. As a result, as shown in FIG. 3 (c), the first birefringent plate 1, the polymer film 2, and the second birefringent plate 3 are sandwiched between the upper pressing plate 14 2 and the lower pressing plate 1 21. Press with a predetermined pressure. After pressing for a predetermined time, a driving device (not shown) is driven to raise the lift shaft 1 4 1 and raise the upper pressure plate 1 4 2. As the upper pressure plate 1 42 rises, the induction holding portion 1 3 2 receives an elastic member; [3 3's plucking force ', and the first birefringent plate with the second birefringent plate 3 bonded to the polymer film 2 1 Hold it up and return to its original position. Next, 'close the vacuum piping 111', introduce the atmosphere into the vacuum processing chamber 110, return it to atmospheric pressure, and open a door (not shown) of the vacuum processing chamber 110 ', and paste the first pair on both sides of the local molecular film 2. The optical low-pass filters of the refractive plates 1 and the second birefringent plate 3 are taken out. This method of bonding the first birefringent plate 1 and the second birefringent plate 3 to the polymer film 2 on both sides using the vacuum bonding device 100 is performed in a vacuum atmosphere. Due to the bonding, the existence of air bubbles can be reliably prevented between the polymer film 2 and the birefringent plates 1 and 3. Again ’By putting the i-th birefringent plate! The induction holding portion 1 3 2 placed on the induction device 130 can determine the position of the birefringent plate 1 and press the plate on the upper side in a state of being held by the induction holding portion 1 2 2: [42 will induce The holding portion 1 3 2 is vertically pushed down, and the first birefringent plate 1 is lowered, and the polymer film 2 or the second birefringent plate 3 arranged at a predetermined position above the lower pressing plate 121 is accurately set as prescribed. Positions overlap and hold them down. Therefore, the optical axes of the first birefringent plate 1, the polymer film 2, and the second birefringent plate 3 can be correctly arranged in a vacuum atmosphere, and can be bonded with good accuracy. The description of the second bonding process is described above. Although the first birefringent plate 1 is held on the induction holding portion 1 3 2, the second birefringent plate 3 may be held on the induction holding portion 1 3 2 so that the polymer film 2 is bonded. The first birefringent plate 1 is placed on the lower pressing plate 1 2 1. In the above description, although both the first bonding process and the second bonding process are performed using the vacuum bonding apparatus 100, in the present invention, the first bonding process does not need to be performed in a vacuum atmosphere It can be completed, so only the second bonding process is performed in a vacuum atmosphere, which is ideal in terms of production efficiency. In addition, although a polymer film having an adhesive layer on both sides is used as an example, an adhesive may be used. At this time, 'in order to promote ultraviolet curing, the upper pressure plate I 42 and the lower pressure plate 1 2 1' are preferably made of glass or the like capable of transmitting ultraviolet rays 18 · (15) (15) 200424574, and ultraviolet rays Illumination lamps are also ideally located in the vacuum processing chamber 110. In addition, it is necessary to set up a preliminary process for applying the adhesive. Also, as shown in FIG. 4, when bonding with an adhesive, it is desirable that heating means such as an electric heater 150 are incorporated in the upper pressure plate 142 and the lower pressure plate 丨 2 丨, respectively. By heating the adhesive by heating during pressing, the adhesive can be softened to eliminate unevenness on the surface, and the bonding of the adhesive can be made stronger. Even 'the inventor's pinned birefringent plate and local molecular film's bonding conditions' is a vacuum atmosphere (degree of vacuum), heating temperature (bonding temperature), and pressing pressure. Good conditions for air bubbles in the bonding surface of polymer film to improve manufacturing yield. This section will be described below. Table 1 shows the results of measuring the area of bubbles remaining on the bonding surface where the degree of vacuum changes when the birefringent plate and the polymer film were bonded. The area of a bubble is a complex shape. For convenience, the longer dimension of the bubble and the longer dimension approximately perpendicular to the longer direction. The product of the two is regarded as its area. The sample is a polymer film made from a birefringent plate with a size of 50mmx50mm and a thickness of 0.7mm, and polycarbonate with an acrylic-based adhesive layer (thickness of about 20 // m) on both sides. The thickness is about 80 μm. 〇 Other bonding conditions include a bonding temperature of 40 ° C, a pressing pressure of 19 600 OPa, and a pressing time of 3 minutes. In addition, the bonding temperature refers to the temperature of the array -19- (16) (16) 200424574 during bonding. Table 1] Vacuum area (mm-) ___---- (Pa) Sample 1 Sample 2 1 0000 30 35 36 5 000 25 23 27 1000 10 6 12 500 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 ____—— According to the result, 'When the degree of vacuum is within the range of 500Pa ~ IPa, there is no air bubble in the shell surface, and good bonding conditions are obtained. Next, using the same method and the same sample as the previous experiment, when the bonding temperature is changed, the results of measuring the area of the bubbles remaining on the bonding surface are shown in Table 2. -20- (17) 200424574 [Table 2] Bubble area at bonding temperature (m m2) (Pa) Sample 1 Sample 2 Sample 3 25 3 0 5 30 0 0 40 0 0 0 50 0 0 60 0 0 0 70 0 0 0 80 0 0 0 90 13 16 7 100 11 14 18 According to this result, when the bonding temperature is in the range of 30 ° C ~ 80 ° C, there are no bubbles in the bonding surface, and a good bonding is obtained. Qualified conditions. In addition, using the same sample as the previous experiment, when the pressure applied to the pressure was changed, the results of measuring the area of bubbles remaining on the bonding surface are shown in Table 3-21-(18) 200424574 [Table 3] Area of pressure bubbles (Mm2) (Pa) Specimen 1 Specimen 2 Specimen 3 328200 30 42 54 656400 9 5 13 1969600 0 0 3282800 0 0 0 3920000 0 0 0 45 96000 0 0 0 In the range of ~ 4 5 96000Pa, there are no bubbles in the bonding surface, and good bonding conditions are obtained. Next, when a second bonding process is performed using a vacuum bonding apparatus, other embodiments will be described with reference to Fig. 5. Fig. 5 (a) is a plan view illustrating a laminated state of the first birefringent plate 1, the local molecular film 2 and the second birefringent plate 3, and Fig. 5 (b) is a cross-sectional view of a state where it is placed on a vacuum bonding device. Fig. 5 (c) is a cross-sectional view of a pressed state. First, as shown in FIG. 5 (b), a buffer material 5 is disposed on the upper surface of the lower pressure plate 1 2 1, and a second birefringent plate 3 is placed at a predetermined position on the buffer material 5. In addition, the material of the buffer material 5 includes rubber sheets such as silicone rubber, polypropylene foam, polyethylene storage boards, urinals and other foamed products or resin sheets, or high-quality paper, photocopying paper, corrugated paper, dustproof paper and other paper, kapok, Fibers such as nylon, -22- (19) (19) 200424574 leather, such as cowhide, are selected from these materials that are softer than metal. Next, the adhesive layer on the other side of the polymer film 2 of the first birefringent plate 1 to which the polymer film 2 is bonded is exposed, and the exposed birefringent layer is down, and the first birefringent plate 1 is induced again. 130 is held by the induction holding portion 1 2. At this time, the first birefringent plate 1, the polymer film 2 and the second birefringent plate 3 are stacked in the vertical direction, as shown in FIG. 5 (a). The rectangular first birefringent plate 1 and the same rectangular shape The polymer film 2 and the second birefringent plate 3 are arranged orthogonally, and the width of the paper surface of the second birefringent plate 3 in the left-right direction is narrower than the width of the polymer film 2 in the same direction. The second birefringent plate 3 placed on the lower pressing plate 1 2 1 and the polymer thin film 2 bonded to the first birefringent plate 1 held by the induced holding portion 1 3 2 are mutually formed. Isolated and face to face. In the arrangement state shown in FIG. 5 (b), the inside of the vacuum processing chamber 110 is evacuated through the vacuum pipe ill, and after reaching a predetermined vacuum degree, the lifting shaft 1 4 1 is driven by a driving device (not shown) to lower it. The upper pressing plate 1 42 gradually descends and abuts the upper end of the induction holding portion 1 3 2, and the upper pressing plate 1 42 resists the elastic member that causes the lifting pins 1 3 1 to pop upwards] 3 3 and will induce the holding部 132 —Push down and lower, so that the polymer film 2 bonded to the first birefringent plate 1 held by the induction holding portion 1 32 abuts against the second placed on the lower pressure plate 1 2 1 After the birefringent plate 3, the upper pressing plate 1 42 pushes the first birefringent plate 1 with a predetermined pressure. Thereby, as shown in FIG. 5 (c), the first birefringent plate 1, the polymer film 2 and the -23- (20) ( 20) 200424574 2 The birefringent plate 3 is pressed under a predetermined pressure. After pressing for a predetermined time, a driving device (not shown) is driven to raise the lift shaft 1 4 1 'to raise the upper pressure plate 1 4 2. As the upper pressure plate 1 4 2 rises, the induction holding portion 1 3 2 receives an elastic member; [3 3's plucking force, and the first birefringence of the second birefringent plate 3 will be bonded to the polymer film 2. The board 1 is held up and returned to the original position. Next, the vacuum pipe 1 1 1 is closed, the atmosphere is introduced into the vacuum processing chamber 1 1 0, and the pressure is returned to the atmospheric pressure. A door (not shown) of the vacuum processing chamber 1 1 0 is opened, and the polymer film 2 is opened. The optical low-pass filter with the first birefringent plate 1 and the second birefringent plate 3 affixed on both sides is taken out. Here, the effect of bonding the cushioning material 5 between the second birefringent plate 3 and the lower pressing plate 1 2 1 will be described. The inventors compared the air bubbles remaining on the bonding surface between the second birefringent plate 3 and the lower pressing plate 1 2 1 by using an experiment, and the case where the cushioning material 5 is arranged between the second birefringent plate 3 and the lower pressing plate 1 2 1. Table 4 shows the results of measuring the area of the bubbles remaining on the bonding surface when the birefringent plate and the polymer film were bonded together in the above configuration and the pressing time was changed. The area of a bubble is a complex shape. For convenience, the longer dimension of the bubble and the approximately vertical dimension of the length of the longer direction are used as the area. In addition, the sample is a polymer film (thickness of about 80mm) using a birefringent plate with a size of 50mmx50mm and a thickness of two sides and polycarbonate formed with an acrylic adhesive layer (thickness about 20 // m) on both sides. β m). -24- (21) 200424574 Other bonding conditions include ‘bonding temperature 4 0 C, pressing pressure 196000Pa, and pressing time 3 minutes. [Table 4] Bubble area (mm 2) during pressing (minutes) No buffer material sample 1 sample 2 sample 3 sample 4 sample 5 sample 6 0.1 10 6 13 33 52 47 0.5 0 0 0 20 23 36 1.0 0 0 0 10 1 5 12 3.0 0 0 0 0 0 0 5.0 0 0 0 0 0 0 10.0 0 0 0 0 0 0 0
根據此結果，有配置緩衝材時，壓著時間在〇. 5分以 上就確認無氣泡存在，不配置緩衝材時壓著時間要在3分 以上才確認無氣泡存在。此原因爲，藉由配置緩衝材可使 貼合面受到均勻的壓力施加，例如若是比較相同壓著時間 ，則因爲能夠以均勻的加壓力進行壓著，故可減少氣泡的 存在，使黏著劑的貼合更爲強固。 使用此種真空貼合裝置100而在高分子薄膜2的兩面 貼合第1雙折射板1及第2雙折射板3的方法，係在真空 氣氛中進行貼合，且在第2雙折射板3及下側壓著板1 2 1 間配置緩衝材5，因此可確實防止高分子薄膜2及雙折射 -25- (22) (22)200424574 板1、3之間存在氣泡。 此外，本實施形態中，雖然舉例在下側壓著板和雙折 射板之間配置緩衝材，但並不侷限於此，亦可在上側壓著 板和雙折射板之間配置，或是上下兩側壓著板和雙折射板 都配置緩衝材。 第2貼合工程後的加壓工程，係爲了使以黏著劑貼合 時能更爲強固而進行的。加壓工程，若在第2貼合工程中 已經獲得足夠貼合強度時，則可免除。加壓方法，係例如 將高分子薄膜2兩面貼合雙折射板1、3而成的光學低通 濾波鏡收納在熱壓爐（auto clave )中，將壓縮空氣等高 壓氣體導入熱壓爐，關閉蓋子，以熱壓爐內藏之加熱器， 在高壓氣體的高壓和加溫之氣氛下對光學低通濾波鏡一邊 加熱一邊加壓。高壓氣體的壓力範圍例如爲 0.3MPa〜熱 壓爐的耐壓上限30MPa左右，溫度爲70〜120 °C左右。又 ，亦可用一般加熱過的壓著板來進行一邊加熱一邊加壓。 以紅外線遮斷膜成膜工程中將紅外線遮斷濾波鏡予以 成膜，是有以下的理由。亦即，CCD係對光有較寬波長 的敏感度，不只對可見光領域而是對在近紅外線領域（ 75 0〜25 OOnrn )的光也有良好的敏感度。可是，一般照相 機的用途中，並不需要人眼所無法看見的紅外線領域，若 是將近紅外線入射至攝像元件則會引發解析度下降或影像 的錯網等不良。因此，視訊攝影機等的光學系中都插入有 色玻璃等紅外線遮斷濾波鏡，而將入射光中的近紅外線予 以遮斷。本實施形態中的光學低通濾波鏡中，藉由設置紅 -26- (23) (23)200424574 外線遮斷濾波鏡，將紅外線遮斷之機能附加在光學低通濾 波鏡上，可免除紅外線遮斷濾波鏡的零件，達到刪減零件 數的目的。 紅外線遮斷濾波鏡，係將由 Ti02、Nb2 0 5、Ta2〇5等 之高折射率介電體所成的高折射率層，和由Si02、MgF2 等之低折射率之介電體所成之低折射率層，彼此層積數十 層而成的構造。 將高折射率層和低折射率層交互成膜在基板上，一般 是用物理成膜法，雖然以一般的真空蒸著法亦爲可行，但 3®是以能穩定控制膜的折射率，且能作成的膜對保管、式 樣環境變化所致之分光特性的經時變化小的離子輔助蒸著 法或離子鍍（Ion Plating)法、濺鍍法等較爲理想。 真空蒸著法，係在高真空中將薄膜材料加熱，令其蒸 發粒子在基板上堆積而形成薄膜的方法。離子輔助蒸著法 ’係在真空蒸著裝置中備有離子束產生裝置和中和器（ neutralizer)，令薄膜材料汽化，藉由離子束產生裝置將 惰性氣體或氧氣離子化並加速而將離子束朝向基板射出， 同時藉由中和器將離子束進行無帶電氣體化而將汽化的薄 膜材料加速，或將附著在基板上的薄膜材料攪拌（mixing )，以使其活性化而蒸著之方法。離子鍍法，係將蒸著粒 子離子化，藉由電場加速而使其附著在基板上，或以氣體 離子將基板上活性化而成膜的方法，有 APS ( Advanced Plasma S o ur c e )、EBEP ( Electron Beam Excited Plasma )法、射頻（Radio Frequency )直接基板施加法（在成膜 -27- (24) (24)200424574 室內產生高頻氣體電漿的狀態下進行反應性之真空蒸著的 方法）等方式。濺鍍法，係令被電場加速的離子，衝撞薄 膜材料，敲擊薄膜材料使薄膜材料從濺鍍靶上蒸發，令蒸 發的粒子堆積在基板上的薄膜形成方法。 高分子薄膜的兩面貼合有水晶板的光學低通濾波鏡， 係由於高分子薄膜或黏著劑較不耐熱，因此在1 〇 〇 t以下 之溫度的低溫成膜較爲理想。 反射防止膜，係無機被膜、有機被膜之單層或多層所 構成。亦可爲無機被膜和有機被膜之多層構造。無機被膜 的材質有，例如 Si〇2、SiO、Zr02、Ti02、TiO、Ti203、 Ti2〇5、AI2O3、Ta2〇5、Ce〇2、MgO、Y2O3、Sn〇2、MgF2 、wo 3等無機物，可爲這些的單獨或兩種以上倂用。又， 多層膜構成時，以最外層爲Si02者爲理想。 無機被膜的多層膜，可舉例如從基材側起Zr〇2層和 Si〇2層的合計光學膜厚爲λ/4、Zr02層的光學膜厚爲λ /4、最上層的5丨02層的光學膜厚爲λ/4之四層構造。 此處，λ爲設計波長，通常採用520nm。 無機被膜的成膜方法，可採用的有例如真空蒸著法、 離子鍍法、濺鍍法、CVD法、飽和容易中藉由化學反應 而析出之方法等。 有機被膜的材質，可舉例如FFP(tetrafluoroethylene (四氟乙烯）-hexafluoropropylene (六氟丙烯）共聚物） 、PTFE ( Poly tetrafluoroethylene，聚四氟乙烯）、ETFE (ethylene (乙燒）-tetrafluoroethylene (四氟乙燒）共聚 -28- (25) (25)200424574 物）等，考慮基材的折射率而選定。成膜方法，除了真空 蒸著法，還可使用旋轉塗佈法、浸塗（dip coat )法等量 產性優良的塗裝方法來成膜。 本發明之光學低通濾波鏡之製造方法中，這些紅外線 遮斷膜成膜工程和反射防止膜成膜工程，亦可省略。 (發明效果） 若根據本發明之光學低通濾波鏡之製造方法，則除了 可確實防止高分子薄膜及雙折射板之間存在有氣泡，還可 使生產性良好。 又，若根據本發明之光學低通濾波鏡之製造方法，則 可在真空氣氛中進行正確位置的貼合。 【圖式簡單說明】 〔圖1〕本發明之光學低通濾波鏡之製造方法的製造 工程之一例的流程圖。 〔圖2〕使用真空貼合裝置進行第1貼合工程時的圖 示。（a)是真空貼合裝置的槪要構成圖，（b)是誘導裝 置的放大剖面圖，（c )是第1雙折射板和高分子薄膜之 重疊配置關係的平面圖，（d )是在上側壓著板和下側壓 著板之間正在進行壓著之狀態的剖面圖。 〔圖3〕使用真空貼合裝置進行第2貼合工程時的圖 示。（a )是第1雙折射板、高分子薄膜及第2雙折射板 之重疊配置關係的平面圖，（b )是第1雙折射板、高分 -29- (26) (26)200424574 子薄膜及第2雙折射板之垂直方向配置關係的剖面圖，（ c )是在上側壓著板和下側壓著板之間正在進行壓著之狀 態的剖面圖。 〔圖4〕分別內藏有加熱手段的上側壓著板和下側壓 著板的槪略構成圖。 〔圖5〕使用真空貼合裝置進行第2貼合工程時的其 他實施形態之圖示。（a )是第1雙折射板、高分子薄膜 及第2雙折射板之重疊配置關係的平面圖， （b )是第1 雙折射板、高分子薄膜及第2雙折射板之垂直方向配置關 係的剖面圖，（c )是在上側壓著板和下側壓著板之間正 在進行壓著之狀態的剖面圖。 〔符號說明〕 1…第1雙折射板 .2…高分子薄膜 3…第2雙折射板 5…緩衝材 1〇〇…真空貼合裝置 1 1 0…真空處理室 121…下側壓著板 130…誘導裝置 131…升降針腳 132…誘導保持部 142…上側壓著板 -30-Based on this result, when a cushioning material is provided, it is confirmed that no bubbles exist when the pressing time is 0.5 minutes or more, and when a cushioning material is not provided, it is necessary to confirm that no bubbles exist when the pressing time is 3 minutes or more. The reason is that the bonding surface can be subjected to uniform pressure application by arranging the buffer material. For example, if the same pressing time is compared, the pressing can be performed with uniform pressing pressure, so the existence of air bubbles can be reduced, and the adhesive can be made. The fit is stronger. The method of bonding the first birefringent plate 1 and the second birefringent plate 3 to both surfaces of the polymer film 2 using such a vacuum bonding apparatus 100 is performed in a vacuum atmosphere, and the second birefringent plate is bonded together. The buffer material 5 is arranged between the 3 and the lower pressing plate 1 2 1, so that the polymer film 2 and the birefringence can be reliably prevented -25- (22) (22) 200424574 The air bubbles exist between the plates 1 and 3. In addition, in this embodiment, the buffer material is arranged between the lower pressing plate and the birefringent plate, but it is not limited to this. It may be arranged between the upper pressing plate and the birefringent plate, or both. Both the side pressure plate and the birefringent plate are provided with a buffer material. The pressurizing process after the second bonding process is performed to make it stronger when bonding with an adhesive. The pressurizing process can be eliminated if sufficient bonding strength has been obtained in the second bonding process. The pressurization method is, for example, placing an optical low-pass filter formed by bonding polymer films 2 on both sides with birefringent plates 1 and 3 in an auto clave, and introducing high-pressure gas such as compressed air into the autoclave. Close the lid and use the heater built in the autoclave to heat and press the optical low-pass filter under the high pressure and warming atmosphere of the high pressure gas. The pressure range of the high-pressure gas is, for example, from about 0.3 MPa to the upper pressure limit of the autoclave at about 30 MPa, and the temperature is about 70 to 120 ° C. It is also possible to apply pressure while heating by using a generally heated pressing plate. There are the following reasons for forming an infrared blocking filter in the film formation process using an infrared blocking film. That is, the CCD system has a wide wavelength sensitivity to light, and has good sensitivity not only to the visible light field but also to light in the near-infrared field (750 to 25 OOnrn). However, in general camera applications, infrared fields not visible to the human eye are not required. If near-infrared rays are incident on the imaging element, problems such as a decrease in resolution or misalignment of images may occur. Therefore, infrared light blocking filters such as colored glass are inserted into optical systems such as video cameras, and near-infrared rays in incident light are blocked. In the optical low-pass filter in this embodiment, by setting a red-26- (23) (23) 200424574 external line blocking filter, the infrared blocking function is added to the optical low-pass filter, which can eliminate infrared rays. Block the parts of the filter to reduce the number of parts. The infrared cut-off filter is a high refractive index layer made of high refractive index dielectrics such as Ti02, Nb205, Ta205, etc., and a low refractive index dielectric made of Si02, MgF2, etc. The low refractive index layer has a structure in which several tens of layers are laminated on each other. The high-refractive-index layer and the low-refractive-index layer are alternately formed on the substrate. Generally, a physical film formation method is used. Although a general vacuum evaporation method is also feasible, 3® is capable of stably controlling the refractive index of the film. The film that can be produced is ideal for ion-assisted evaporation, ion plating, and sputtering methods with small changes over time in the spectral characteristics caused by changes in the design environment. The vacuum evaporation method is a method in which a thin film material is heated in a high vacuum, and its vaporized particles are deposited on a substrate to form a thin film. Ion-assisted evaporation method is equipped with an ion beam generating device and a neutralizer in a vacuum evaporation device to vaporize a thin film material. The ion beam generating device ionizes and accelerates an inert gas or oxygen to accelerate the ionization. The beam is emitted toward the substrate, and at the same time, the ionized beam is ionized by a neutralizer to accelerate the vaporized thin film material, or the thin film material attached to the substrate is mixed to activate and vaporize the thin film material. method. The ion plating method is a method in which vaporized particles are ionized and adhered to a substrate by an electric field acceleration, or a substrate is activated by a gas ion to form a film. APS (Advanced Plasma Source), EBEP (Electron Beam Excited Plasma) method, radio frequency (Radio Frequency) direct substrate application method (under film formation-27- (24) (24) 200424574) Method) and so on. The sputtering method is a thin film forming method in which ions accelerated by an electric field collide with a thin film material and strike the thin film material to evaporate the thin film material from a sputtering target, so that evaporated particles are deposited on a substrate. An optical low-pass filter with a crystal plate bonded to both sides of the polymer film, because the polymer film or the adhesive is less heat resistant, it is ideal to form a film at a low temperature of less than 1000 t. The antireflection film is composed of a single layer or multiple layers of an inorganic film and an organic film. It may have a multilayer structure of an inorganic coating and an organic coating. The materials of the inorganic coating include, for example, Si02, SiO, Zr02, Ti02, TiO, Ti203, Ti205, AI2O3, Ta205, Ce02, MgO, Y2O3, Sn02, MgF2, wo3 and other inorganic materials, These can be used alone or in combination of two or more. When the multilayer film is formed, it is preferable that the outermost layer is SiO 2. The multilayer film of the inorganic coating may include, for example, the total optical film thickness of the ZrO2 layer and the SiO2 layer from the substrate side is λ / 4, the optical film thickness of the Zr02 layer is λ / 4, and the uppermost layer is 5 丨 02. The optical film thickness of the layer is a four-layer structure of λ / 4. Here, λ is a design wavelength, and 520 nm is usually used. As the method for forming the inorganic film, for example, a vacuum evaporation method, an ion plating method, a sputtering method, a CVD method, a method of precipitating by a chemical reaction in the case of easy saturation, and the like can be used. Examples of the material of the organic coating include FFP (tetrafluoroethylene-hexafluoropropylene), PTFE (Polytetrafluoroethylene), ETFE (ethylene-tetrafluoroethylene (tetrafluoroethylene) Ethylene fired) copolymerization-28- (25) (25) 200424574), etc., selected in consideration of the refractive index of the substrate. As the film formation method, in addition to the vacuum evaporation method, a spin coating method or a dip coat method can be used to form a film with excellent mass productivity. In the manufacturing method of the optical low-pass filter of the present invention, these infrared blocking film film forming processes and reflection preventing film film forming processes may be omitted. (Effects of the Invention) According to the method for manufacturing an optical low-pass filter according to the present invention, in addition to reliably preventing air bubbles between the polymer film and the birefringent plate, productivity can be improved. In addition, according to the method for manufacturing an optical low-pass filter according to the present invention, it is possible to perform bonding at a correct position in a vacuum atmosphere. [Brief description of the drawings] [Fig. 1] A flowchart of an example of a manufacturing process of a method for manufacturing an optical low-pass filter of the present invention. [Fig. 2] A diagram when a first bonding process is performed using a vacuum bonding apparatus. (A) is a schematic diagram of the structure of a vacuum bonding device, (b) is an enlarged sectional view of an induction device, (c) is a plan view of an overlapping arrangement relationship between a first birefringent plate and a polymer film, and (d) is a A cross-sectional view of a state in which the upper pressing plate and the lower pressing plate are being pressed. [Fig. 3] A diagram when a second bonding process is performed using a vacuum bonding apparatus. (A) is a plan view of the overlapping arrangement relationship of the first birefringent plate, the polymer film, and the second birefringent plate, (b) is the first birefringent plate, high score-29- (26) (26) 200424574 sub-film A cross-sectional view of the vertical arrangement relationship between the second birefringent plate and the second birefringent plate is (c) a cross-sectional view showing a state in which pressing is performed between the upper pressing plate and the lower pressing plate. [Fig. 4] A schematic configuration diagram of an upper pressing plate and a lower pressing plate having heating means built therein, respectively. [Fig. 5] An illustration of another embodiment when the second bonding process is performed using a vacuum bonding apparatus. (A) is a plan view showing the overlapping arrangement relationship of the first birefringent plate, the polymer film, and the second birefringent plate, and (b) is the arrangement relationship of the first birefringent plate, the polymer film, and the second birefringent plate in a vertical direction; (C) is a cross-sectional view of a state where pressing is being performed between the upper pressing plate and the lower pressing plate. [Description of Symbols] 1 ... 1st birefringent plate. 2 ... Polymer film 3 ... 2nd birefringent plate 5 ... Buffer material 100 ... Vacuum bonding device 1 1 0 ... Vacuum processing chamber 121 ... Lower pressing plate 130 ... induction device 131 ... lifting pin 132 ... induction holding portion 142 ... upper pressing plate -30-