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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’尤其是有 關提升將高分子薄膜夾在雙折射板之構造的光學低通濾波 鏡之製造良率的技術。 【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常使 用CCD或CMOS %攝像兀件。該攝像兀件係藉由以所疋 間隙配列成矩陣狀的像素而將光學像轉換成電訊號，將映 像予以攝影。此種攝像裝置中，光學像的空間頻率一旦超 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 (2) 1242082 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) 1242082 〔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500Pa〜IPa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) 1242082 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3 (TC〜8 (TC。 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〜 45 96000Pa ° 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（fi lm ) 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) 1242082 板壓者至則δ己局分卞薄膜上的第2貼合工程c 第2發明係提供〜種在第1發明之光學低通濾波鏡之 製造方法中’前記第2貼合工程，是在真空氣氛下，先令 貼合有前記高分子薄膜的前記第1雙折射板和前記第2雙 折射板彼此離間而令前記高分子薄膜和前記第2雙折射板 呈面對面配置後，再令前記高分子薄膜和前記第2雙折射 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鏡之 製造方法中’前記第2貼合工程是在真空氣氛下，令貼合 有前記高分子薄膜的前記第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前記第 1雙折射板或前記第2雙折射板之另一方彼此離間而令前 記高分子薄膜和前記第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前記誘導裝置內的前記第1雙 折射板或第2雙折射板之一方抵抗前記誘導裝置之彈撥力 而降下，藉由前記上側壓著板使得前記高分子薄膜和前記 第2雙折射板彼此接近，而使前記第1雙折射板、前記高 分子薄膜以及前記第2雙折射板在前記上側壓著板和前記 下側壓著板之間夾緊壓著。 第4發明係提供一種在第1〜3發明之任一光學低通 濾波鏡之製造方法中，前記第2貼合工程是在已加熱的上 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 -9- (6) 1242082 製造方法中，前記第1貼合工程’是在真 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 濾波鏡之製造方法中’具有：對前記第2 的光學低通濾波鏡一邊加熱一邊施加壓力 〇 第7發明係提供一種在第1〜6發明 濾波鏡之製造方法中’前記真空氣氛係在 範圍內。 第8發明係提供一種在第1〜6發明 濾波鏡之製造方法中’前記壓著的加壓力 至4596000Pa之範圍內。 第9發明係提供一種在第4發明之光 製造方法中，前記第2貼合工程中的加美 至8 0 °C之範圍內。 第1 〇發明係提供一種在第1〜6發明 濾波鏡之製造方法中，在前記第1貼合工 氛下將前記第2雙折射板壓著至前記高分 合工程中，在下側壓著板和雙折射板之間 壓著板和雙折射板之間，夾著緩衝材而進 【實施方式】 以下將就本發明之光學低通濾波鏡之 形態加以說明，但是本發明並非侷限於以 空氣氛下將前記 之任一光學低通 貼合工程所製造 之加壓處理工程 之任一光學低通 500Pa 至 ipa 之 之任一光學低通 是在 1 969600Pa 學低通濾波鏡之 A溫度是在3 0 °c 之任一光學低通 程後，在真空氣 子薄膜的第2貼 ，或/及在上側 行壓著。 製造方法的實施 下實施形態。 -10- (7) 1242082 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 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#m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 之情形。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) 1242082 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- 1242082 (9) 將貼合有第1雙折射板的高分子薄膜，貼 折射板的第2貼合工程中，爲了要使硬質板彼 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 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 合之際第1雙折射板和高分子薄膜的重疊位置 圖’圖2(d)係真空貼合裝置正在進行壓著 的側面圖。 該真空貼合裝置1 〇 〇，係如圖2 ( a )所示 處理室110，以真空配管ηι連接至未圖示的 而可抽成真空。真空處理室110內之底面的上 已經平滑處理過之平整的固定盤也就是下側壓 下側壓著板1 2 1係大於第1雙折射板1，在載 射1板時，將第1雙折射板1整體保持而周圍 大小的面積。下側壓著板1 2 1的兩端部側上配 側壓著板121而可上下升降的誘導裝置130。 該誘導裝置130，如圖2(b)的放大圖所 成可在下側壓著板121垂直方向上升降的升降 上端處，設有針狀金屬朝外面呈L字狀曲折而 誘導保持部132。該誘導保持部132，除了可 第1雙折射板1之短邊11之兩端緣予以保持 短邊1 1之兩側面距離兩側的位置。升降針腳 彈性構件1 3 3而往上方彈撥，平常誘導保持部 合至第2雙 此貼合，需 程兩者均可 〇 )係進行貼 關係的平面 動作之狀態 ，具備真空 真空裝置， 面，配置著 著板1 2 1。 匱第1雙折 還留有充分 設有貫通下 示，被保持 針腳1 3 1的 成之形狀的 將矩陣狀的 ，還規定了 1 3 1係藉由 132是在下 -13- (10) 1242082 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1被保 持在空中。升降針腳1 3 1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1 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。 局分子薄膜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 4 2，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) 1242082 工程洗淨之，已經去除了表面附著物者。首先 處理室1 1 0之未圖示的門而將已經讓一面的黏 之高分子薄膜2，令露出之黏著劑層爲上而載 者板1 2 1上的所定位置。其次，將第1雙折射 誘導裝置130的誘導保持部132上。藉此，第 1和高分子薄膜2的配置，成爲了如圖2 ( c ) 配置。亦即，由上來看，第1雙折射板1的短 兩端緣是從高分子薄膜2之兩端緣往外伸出。 板1的短邊1 1側的兩端緣是被誘導裝置1 3 〇 部1 3 2所保持，第丨雙折射板丨則被保持在高 上方的空間中，和高分子薄膜2彼此離間而面; 其次，將真空處理室110之未圖示的門關 示之真空裝置作動，透過真空配管111將真空 內抽成真空。真空處理室110內到達所定真空 圖示之驅動裝置驅動升降軸141而使其下降。 下降，上側壓著板1 42下降而抵觸誘導保持部 ，上側壓著板1 42便抵抗使升降針腳1 3 1往上 性構件1 3 3的彈撥力而將誘導保持部1 3 2 —起 ，使得被誘導保持部1 3 2保持的第1雙折射板 置於下側壓著板1 2 1上的高分子薄膜2後， 1 42會以所定的壓力將第1雙折射板1推壓。 2 ( d )所示，上側壓著板1 42和下側壓著板1 : 著第1雙折射板1及高分子薄膜2而以所定的 此時第1雙折射板1和高分子薄膜2之重疊會 ，打開真空 著劑層露出 置於下側壓 板1載置於 1雙折射板 所示的重疊 i邊11側之 第1雙折射 的誘導保持 分子薄膜2 對面配置。 閉’令未圖 處理室1 1 0 度後，以未 升降軸141 132的上端 方彈撥的彈 下推而下降 1抵觸至載 上側壓著板 藉此，如圖 Π之間，夾 壓力壓著。 保持圖2 ( -15- (12) 1242082 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]42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高分子薄膜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1 1 0內，使其回到大氣壓力而結束第1 貝占€ IE手呈。 其次，一邊參照圖3 —邊說明使用真空貼合裝置1 〇 〇 進行第2貼合工程之方法。圖3 ( a )係第1雙折射板i、 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 0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。令局分子薄膜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) 1242082 至被誘導保持部1 3 2所保持的第1雙折射板！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1 ! ! 將真空處理室1 1 0內抽成真空，到達所定真空度後，以未 圖不之驅動裝置驅動升降軸1 4 1而使其下降，上側壓著板 142逐漸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〗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 42會以所定的壓力將第1雙折射板1推壓。 藉此’如圖3 ( 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 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 142的上升，誘導保持部132受到彈性構件133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11 1關閉，將大氣導入真空處理室丨丨〇內， 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。 此種使用真空貼合裝置100而在高分子薄膜2兩面貼 -17- (14) 1242082 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 之間可確貫防止有氣泡存在。 又’藉由將第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，可決定第1雙折射板！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丨42將誘導保持 部1 3 2垂直推下，第1雙折射板〗會下降，而和配置於下 方之下側壓著板1 2 1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i 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132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1 42和下側壓著板1 2 1，是以能夠透過紫外線 -18- 1242082 (15) 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 〇者較爲理想。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 4 2和下側壓著板1 2 1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，發明人針對雙折射板和高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 20//m)的聚碳酸酯爲素材而成的高分子薄膜（厚度約8〇 μ m )。 其他的貼合條件有，貼合溫度40 °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) 1242082 貼合時雙折射板和高分子薄膜的溫度。 〔表1〕发明 Description of the invention [Technical field to which the invention belongs] The present invention relates to a method of manufacturing an optical low-pass filter, and in particular to improving the manufacturing yield of an optical low-pass filter having a structure in which a polymer film is sandwiched by a birefringent plate. technology. [Prior art] CCD or CMOS% imaging elements are often used in imaging devices such as digital still cameras or digital video cameras. The camera element converts an optical image into an electrical signal by arranging pixels in a matrix form with the gaps in between, and photographs the image. In such an imaging device, once the spatial frequency of the optical image exceeds 1/2 of the sampling frequency determined by the pixel-dominated column gap, a pseudo-like signal such as a moire occurs and the image quality is 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 an adhesive or (2) 1242082 adhesive on both sides of the polymer film to attach the two crystal plates to each other. engineering. 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 in a vacuum atmosphere does not cause bubbles to remain, manufacturing yield can be improved." However, it takes time to reduce the pressure from atmospheric pressure to vacuum, which leads to a decrease in production efficiency. Therefore, it is necessary to minimize the engineering limit in a vacuum atmosphere to avoid a decline in production efficiency. 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. Therefore, 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) 1242082 [Means to solve the problem] In order to achieve the above-mentioned purpose, as a result of careful review, the inventor found that it is necessary to bond the rigid first birefringent plate and the second birefringent plate on both sides of the polymer film. The fact that the first laminating process of laminating the polymer film on the first birefringent plate is performed first, and then the two laminating processes of the second laminating process of laminating the polymer film on the second birefringent plate; And in the first bonding process of bonding a polymer film to a first birefringent plate, by extruding the polymer film while extruding air bubbles using a roller or the like, air bubbles will not run even in the atmosphere. The fact that it must be performed in a vacuum atmosphere in the second bonding process where the hard boards are bonded to each other; and the fact that the vacuum atmosphere is ideally 500 Pa to IPa; and by making the second bonding process in a vacuum Under the atmosphere, in addition to improving the manufacturing yield, the fact that the decrease 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. In the second bonding process, a 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 performed by the following method: 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 other (4) 1242082 of the second birefringent plate is 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 kept being induced. One of the first birefringent plate or the second birefringent plate in the 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, thereby making the first birefringence. The 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 range of the heating temperature is 3 (TC ~ 8 (TC). Therefore, it can be more firmly adhered by clamping and pressing between the heated pressing plates. At this time, pressing The ideal range of the applied pressure is 1 9 6 9 6 0 0 P a ~ 45 96000Pa °. By pressing while heating, it can be more firmly adhered to it. By pressing on the pressure plate and the double The buffer material is sandwiched between the refracting plates and heated while being pressed. The buffer material can absorb the minute irregularities of the birefringent plate or the polymer film, and can evenly press it. This can strengthen the birefringent plate and the polymer film. Therefore, the first invention is to provide an optical low-pass filter in which a polymer thin film (fi lm) is sandwiched between a rigid first birefringent plate and a rigid second birefringent plate. The manufacturing method is characterized in that: the first laminating process of laminating the first birefringent plate of the preface to the polymer film of the preface; and the second birefringence of the preface in a vacuum atmosphere after the first laminating process- 8- (5) 1242082 The second bonding process on the δ-layer tillering film from the plate presser to the c-second invention Provide ~ Kind of the "Previous Second Laminating Process" in the method of manufacturing the optical low-pass filter of the first invention, which is to prescribe the first birefringent plate and the first birefringent plate to which the prepolymer polymer film is bonded in a vacuum atmosphere. 2 The birefringent plates are spaced apart from each other so that the prescriptive polymer film and the prescriptive second birefringent plate are arranged face to face, and then the prescriptive polymer film and the prescriptive second birefringent plate are brought close to each other and pressed. In the method for manufacturing an optical low-pass filter according to the first invention, a second pre-lamination process of the preface is performed under a vacuum atmosphere, so that the first pre-birefringent plate or the second birefringent plate of the pre-laminated polymer film is bonded under a vacuum atmosphere. On one side, it is held on an induction device that is lifted up and down and is constantly plucked upwards, and then it is connected to the first birefringent plate or the second birefringent plate of the preamble that is arranged on the pressing plate located below and below it. After the other party is separated from each other and the prescriptive polymer film and the prescriptive second birefringent plate are disposed to face each other, the upper pressing plate is lowered and the prescriptive first birefringent plate or the second birefringent held in the prescriptive induction device is lowered. One side resists the plucking force of the preamble induction device, and lowers the preamble polymer film and the preamble second birefringent plate by approaching the prepress upper side pressing plate, so that the preamble first birefringent plate, preamble polymer film, and preamble first 2 The birefringent plate is clamped and clamped between the pre-pressing plate and the pre-pressing plate. The fourth invention provides a method for manufacturing an optical low-pass filter according to any one of the first to third inventions. The second bonding process is clamping and pressing between the heated upper and lower pressing plates. The fifth invention provides a method of manufacturing the optical low-pass filter of the first invention of the -9- (6) 1242082, the preface The first bonding process is to press the true first birefringent plate to the polymer film of the foregoing. The sixth invention is to provide a method for manufacturing the filter of the first to fifth inventions, which includes: having a lower optical performance than the second of the foregoing. The pass filter is heated while applying pressure. The seventh invention provides a method for manufacturing a filter according to the first to sixth inventions, wherein the vacuum atmosphere is in a range described above. The eighth invention provides a method of manufacturing a filter lens according to the first to sixth inventions, which has a pressing force in the range of 4596000Pa. The ninth invention is a method for manufacturing a light according to the fourth invention, in which the range from Canada to the United States in the second bonding process described above is within a range of 80 ° C. The tenth invention is to provide a method for manufacturing a filter according to the first to sixth inventions, in which the second birefringent plate of the foregoing is pressed under the first laminating atmosphere of the foregoing to the high opening and closing process of the foregoing, and the lower side is pressed. Between the plate and the birefringent plate, between the pressing plate and the birefringent plate, sandwiching the buffer material [Embodiment] The following describes the form of the optical low-pass filter of the present invention, but the present invention is not limited to In an air atmosphere, any optical low-pass of 500Pa to ipa, any optical low-pass of any pressurized processing process made by any of the optical low-pass bonding processes described above is 1 969600Pa. The A temperature of the low-pass filter is After any optical low-pass at 30 ° C, press on the second patch of the vacuum gas film or / and press on the upper side. Implementation of Manufacturing Method The following embodiment will be used. -10- (7) 1242082 The optical low-pass filter that is the object of the manufacturing method of the optical low-pass filter of the present invention includes a 1/4 wavelength plate made of a polymer film sandwiched between two birefringent plates. The structure of the vertical additional type of three-layer structure is an example. A birefringent plate is generally a crystal plate with a predetermined crystal plane. The polymer film constituting the 1/4 wavelength 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 incident light from linear polarization to circular polarization. A polymer film of a predetermined thickness extending through one axis has the characteristic that the larger the incident light wavelength, the larger the birefringence. A polymer film extending through one axis is, for example, a plastic film with a thickness of about 80. These birefringent plates and polymer films need to be precisely arranged with each optical axis facing a predetermined direction. In order to attach the birefringent plate to both sides of the polymer film, an adhesive or an adhesive is used. Generally, the adhesive is selected from a UV-curing type that has good production efficiency. As the adhesive, a type having a good light transmission property is selected. In some cases, an adhesive layer of about 20 m is formed on both surfaces of the polymer film, and is supplied in the form of a double-sided tape. In addition, there is a case where an adhesive layer is formed only on one side of a polymer film. This polymer film is adhered by an adhesive on the surface where no adhesive layer is provided. Figure 1 is a flowchart of the main manufacturing process of an optical low-pass filter. The manufacturing process of the optical low-pass filter is divided into a case where the first birefringent plate and a second birefringent plate are formed using an infrared blocking film and an anti-reflection film, and the bonding is performed after the bonding. Cases where an infrared blocking film and an anti-reflection film are formed. When using a 1st birefringent plate and a 2nd birefringent plate with an infrared blocking film and an anti-11-(8) 1242082 anti-radiation film formed thereon, the bonding is performed on the first birefringent plate and the second birefringent plate. The film forming process of the infrared blocking film and the anti-reflection film is performed on one side of each of the outer surfaces of the refractive plates. Once the infrared blocking film is formed, the birefringent plate may be warped. Therefore, it is preferable to form the infrared blocking film and the anti-reflection film 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. In addition, although the production efficiency may be reduced, the first bonding process may be performed in a vacuum atmosphere. -12- 1242082 (9) In the second bonding process of attaching the polymer film to which the first birefringent plate is bonded, and the refractive plate, the rigid plates must be bonded together in a vacuum atmosphere. Fig. 2 (a) is a side perspective view of the main components of the vacuum bonding device used in the first bonding process and the second bonding process. Figure 2 (b) is an enlarged view of the induction device, and Figure 2 (c) The overlapping position of the first birefringent plate and the polymer film is shown in FIG. 2 (d), which is a side view of the vacuum bonding device being pressed. The vacuum bonding device 100 is shown in FIG. 2 (a). The processing chamber 110 is connected to a vacuum pipe (not shown) and evacuated. The bottom surface of the vacuum processing chamber 110 has a flat fixed plate that has been smoothed, that is, a lower pressing plate 1 2 The 1 series is larger than the first birefringent plate 1. When the first plate is projected, the entire area of the first birefringent plate 1 is held and the surrounding area is large. The lower pressing plate 1 2 1 is pressed on the side of both ends of the lower pressing plate 1 2 1 The plate 121 can be raised and lowered by an induction device 130. As shown in the enlarged view of FIG. 2 (b), the induction device 130 can be raised and lowered at the upper end of the plate 121 in the vertical direction. The L-shaped zigzags induce the holding portion 132. The induction holding portion 132 can be provided at both ends of the short side 11 of the first birefringent plate 1 Keep the two sides of the short side 1 1 away from both sides. Elevate the pin elastic member 1 3 3 and flick upwards, and usually induce the holding part to close to the second pair. This process can be performed on both sides. The state of the plane operation of the relationship includes a vacuum device, and a plate 1 2 1 is arranged on the surface. The first double fold is still fully equipped with a penetrating below, and the shape of the pins 1 3 1 is held in a matrix shape, and the 1 3 1 series is also specified by 132 is under 13- (10) 1242082 The upper side of the side pressure plate 1 2 1 is kept apart. By holding the first birefringent plate 1 on the induction holding portion 1 3 2, the first birefringent plate 1 can be held in the air. The lift pins 1 3 1 resist the plucking force of the elastic member 1 3 3 by pressing down vertically until the first birefringent plate 1 held by the induced holding portion 1 3 2 contacts the lower side. The upper position of the pressure plate 1 2 1. In addition to the coil springs shown in the figure, the elastic members 1 3 3 can also be exemplified by springs such as leaf springs and fluid springs, or elastic bodies such as rubber. As shown in FIG. 2 (c), the width of the local molecular 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 4 2 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 beforehand by a process of -14- (11) 1242082, and the surface attachments have been removed. First, the door (not shown) of the processing chamber 1 10 will be treated with the polymer film 2 on one side so that the exposed adhesive layer is on top and the predetermined position on the carrier plate 1 2 1. Next, the induction holding unit 132 of the first birefringence induction device 130 is placed. As a result, the arrangement of the first and polymer films 2 becomes the arrangement shown in Fig. 2 (c). That is, from the above point of view, the short end edges of the first birefringent plate 1 protrude outward from the both end edges of the polymer film 2. The two edges of the short side 11 of the plate 1 are held by the induction device 1 30 and the portion 12 32, and the 丨 birefringent plate 丨 is held in a space above the high space and separated from the polymer film 2 Secondly, the vacuum processing chamber 110, which is not shown in the door closed, operates a vacuum device, and the inside of the vacuum is evacuated through the vacuum pipe 111. The driving device shown in the predetermined vacuum in the vacuum processing chamber 110 drives the lifting shaft 141 to lower it. Lowering, the upper pressing plate 1 42 is lowered and abuts against the induction holding portion, and the upper pressing plate 1 42 resists the plucking force of the lifting pins 1 3 1 to the upper member 1 3 3 to raise the induction holding portion 1 3 2 together, After the first birefringent plate held by the induction holding portion 1 3 2 is placed on the polymer film 2 on the lower pressing plate 1 2 1, 1 42 pushes the first birefringent plate 1 with a predetermined pressure. As shown in FIG. 2 (d), the upper pressing plate 1 42 and the lower pressing plate 1: the first birefringent plate 1 and the polymer film 2 are pressed, and the first birefringent plate 1 and the polymer film 2 are determined at this time. During the overlap, the vacuum electret layer is opened to expose the first birefringent induced retention molecular film 2 placed on the lower side platen 1 and placed on the side 11 of the overlap i shown by the birefringent plate. After closing the door, the processing chamber is 110 degrees, and the upper side of the shaft 141 132 is not pushed down to push down the plunger and it is lowered by 1 against the load plate on the upper side, as shown in Figure Π. . Keep the configuration shown in Figure 2 (-15- (12) 1242082 c). After pressing for a predetermined time, a driving device (not shown) is driven to raise the lifting shaft 1 4 1 and the upper pressing plate 42 is raised. 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 polymer film 2 and returns. To the original position. Next, the vacuum piping 111 of the vacuum processing chamber 110 was shut off, and the atmosphere was introduced into the vacuum processing chamber 110 to return it to atmospheric pressure to end the 1st IE presentation. Next, a method for 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 i, 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), the plate 1 2 1 is pressed 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 local molecular film 2 is exposed, the exposed adhesive layer is lowered, 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 is bonded to -16- (13) 1242082 to the first birefringent plate held by the induced holding portion 1 3 2! The polymer thin film 2 is arranged facing away from each other. In the configuration shown in Figure 3 (b), the vacuum processing chamber 1 10 is evacuated through the vacuum piping 1!! After reaching the predetermined vacuum degree, the lifting shaft is driven by a drive device (not shown) 1 4 1 When it is lowered, the upper pressing plate 142 is gradually lowered and abuts the upper end of the induction holding portion 132, and the upper pressing plate 1 42 resists the elastic member that causes the lifting pins 1 3 1 to be pulled upwards. Holder 1 3 2 —Push down and lower, so that the polymer film 2 bonded to the first birefringent plate 1 held by the induced holder 1 3 2 abuts against the lower pressure plate 1 2 1 After the second birefringent plate 3 is placed on the upper side, the upper pressing plate 1 42 presses the first birefringent plate 1 at a predetermined pressure. By this, 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 121 so that Pressed 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 142 rises, the induction holding portion 132 receives the plucking force of the elastic member 133 and holds the first birefringent plate 1 with the second birefringent plate 3 bonded to the polymer film 2 in a state of being held. Ascend and return to the original position. Next, the vacuum piping 11 1 is closed, the atmosphere is introduced into the vacuum processing chamber 丨 丨 0, and it is returned to atmospheric pressure. The door (not shown) of the vacuum processing chamber 110 is opened, and the polymer film 2 is attached on both sides. The optical low-pass filters of the first birefringent plate 1 and the second birefringent plate 3 are taken out. This method of using the vacuum bonding apparatus 100 to stick -17- (14) 1242082 to both surfaces of the polymer film 2 and bonding the first birefringent plate 1 and the second birefringent plate 3 is performed in a vacuum atmosphere. Therefore, the existence of air bubbles can be reliably prevented between the polymer film 2 and the birefringent plates 1 and 3. Furthermore, by placing the first birefringent plate 1 on the induction holding unit 1 3 2 of the induction device 130, the first birefringent plate can be determined! Position, the state is held by the induction holding portion 1 3 2 and the induction holding portion 1 3 2 is vertically pushed down by the upper pressing plate 丨 42, and the first birefringent plate is lowered, and is arranged below the bottom The polymer film 2 or the second birefringent plate 3 at a predetermined position on the side pressing plate 1 2 1 is overlapped at a predetermined correct position and pressed. Therefore, the optical axes of the i-th birefringent plate 1, the polymer film 2, and the second birefringent plate 3 can be correctly arranged in a vacuum atmosphere and 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 132 so that the first polymer film 2 is bonded. The 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 pressing plate 1 42 and the lower pressing plate 1 2 1 are preferably made of glass or the like capable of transmitting ultraviolet rays 18 to 1242082 (15). It is preferable to install in the vacuum processing chamber 110. In addition, it is necessary to set up a preliminary process for applying the adhesive. Further, as shown in Fig. 4, when bonding with an adhesive, it is desirable that heating means 150 such as an electric heating heater is built in the upper pressure plate 1 42 and the lower pressure plate 1 2 1. 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. Moreover, the inventors conducted experiments on the bonding conditions of the birefringent plate and the polymer film, that is, the vacuum atmosphere (degree of vacuum), heating temperature (bonding temperature), and pressing pressure, and found that the birefringent plate and the Good conditions for air bubbles in the bonding surface of molecular films 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 was a polymer film (thickness of 50 mm x 50 mm and a thickness of 0.7 mm using a birefringent plate) and polycarbonate with an acrylic adhesive layer (thickness of about 20 // m) on both sides. (About 80 μm). Other bonding conditions include a bonding temperature of 40 ° C, a pressing pressure of 1 9 600 OPa, and a pressing time of 3 minutes. In addition, the bonding temperature refers to the temperature of the formation -19-(16) 1242082 during the bonding of the birefringent plate and the polymer film. 〔Table 1〕
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- 1242082 (17) 〔表2〕 貝占€ Μ度 氣泡面積（m m 2) (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 (TC〜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) 1242082 〔表3〕 加壓力 氣泡面積（mm2) (Pa) 試料1 試料2 試料3 328200 30 42 54 6 5 6400 9 5 13 1969600 0 0 0 3282800 0 0 0 3920000 0 0 0 4596000 0 0 0 根據該結果，當壓著的加壓力在1969600Pa〜 4596000Pa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、高分子薄膜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12 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 丙烯、聚乙烯板、尿烷等發泡品或樹脂片、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) 1242082 牛皮等皮革類等，從這些較金屬還要柔軟的 而爲之。 其次，令貼合有高分子薄膜2的第1雙 分子薄膜2的另一面黏著劑層露出，令露出 下而將第1雙折射板1再度被誘導裝置130 1 3 2所保持。此時，第1雙折射板1、高分 2雙折射板3的垂直方向層疊，係如圖5 ( a 狀的第1雙折射板1和同爲矩形狀的高分子 雙折射板3係成直交配置，第2雙折射板3 向之寬度係窄於同方向上高分子薄膜2的寬 下側壓著板1 2 1上的第2雙折射板3，和貼 持部1 3 2所保持的第1雙折射板1的高分子 彼此離間而面對面配置。 在圖5 ( b )所示的配置狀態下，透過 將真空處理室110內抽成真空，到達所定真 圖示之驅動裝置驅動升降軸141而使其下降 142逐漸下降而抵觸誘導保持部132的上端 1 42便抵抗使升降針腳1 3 1往上方彈撥的彈 彈撥力而將誘導保持部1 3 2 —起下推而下降 保持部1 3 2保持的貼合有第1雙折射板1的 ，抵觸至載置於下側壓著板1 2 1上的第2雙 上側壓著板1 42會以所定的壓力將第1雙折 藉此，如圖5 ( c )所示，上側壓著板 著板1 21之間，夾著第1雙折射板1、高分 材質當中選擇 折射板1之高 的黏著劑層爲 的誘導保持部 子薄膜2及第 d所示，矩形 薄膜2及第2 的紙面左右方 度。被載置於 合至被誘導保 薄膜2，是成 真空配管111 空度後，以未 ’上側壓著板 ’上側壓著板 性構件1 3 3的 ’使得被誘導 f局分子薄膜2 折射板3後， 射板1推壓。 142和下側壓 子薄膜2及第 -23- 1242082 (20) 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M2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1 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 0內， 使其回到大氣壓力，將真空處理室1 1 0之未圖示的門打開 ’而將在筒分子薄膜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，厚度〇.7mm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 0// m)的聚碳酸酯爲素材而成的高分子薄膜（厚度約80 // m )。 -24- (21) 1242082 其他的貼合條件有，貼合溫度4 0 °C 、壓著家壓力 1 9 6 0 0 0 P a、壓著時間3分鐘。 〔表4〕 壓著時 氣泡面積（mm2) 間（分） 有緩衝材 ί 浜緩衝材 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 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 ’則医1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1〇〇而在高分子薄膜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- 1242082 (22) 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 OOnm )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) 1242082 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。 紅外線遮斷漉波鏡，係將由 T i Ο 2、N b 2 Ο 5、T a 2 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 還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 Source) 、E B E P ( Electron Beam Excited Plasma )法、射頻（Radio Frequency )直接基板施加法（在成膜 -27- 1242082 (24) 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 °c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 Si02、SiO、Zr02、Ti02、TiO、Ti203、 Ti2〇5、AI2O3、Ta2〇5、Ce〇2、MgO、Y2O3、Sn〇2、MgF〕 、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 02層的合計光學膜厚爲；I / 4、Zr02層的光學膜厚爲λ /4、最上層的Si02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5 20nm。 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、C V D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 (四氟乙燒）-hexafluoropropylene (六氟丙稀）共聚物） 、PTFE ( Poly tetrafluoroethylene，聚四氟乙烯）、ETFE (ethylene (乙儲）-tetrafluoroethylene (四氟乙儲）共聚 -28- 1242082 (25) 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i貼合工程時的圖 不。（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 不。（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- 1242082 (26) 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 100…真空貼合裝置 1 10···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 1 4 2…上側壓著板 -30-According to this result, when the degree of vacuum is within the range of 500 Pa to IPa, there are no air bubbles in the bonding 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- 1242082 (17) 〔Table 2〕 Shell area € MM degree bubble area (mm 2) (Pa) Sample 1 Sample 2 Sample 3 25 3 0 5 30 0 0 40 0 0 0 50 0 0 0 60 0 0 0 70 0 0 0 80 0 0 90 13 16 7 100 11 14 18 According to this result, when the bonding temperature is in the range of 3 (TC ~ 80 ° C), there are no bubbles in the bonding surface, and a good Bonding conditions. The results of measuring the area of bubbles remaining on the bonding surface when using the same sample as in the previous experiment to change the pressing pressure are shown in Table 3-21-(18) 1242082 [Table 3] Pressure bubble area (mm2) (Pa) Sample 1 Sample 2 Sample 3 328200 30 42 54 6 5 6400 9 5 13 1969600 0 0 3282800 0 0 0 3920,000 0 0 0 4596000 0 0 0 When the applied pressure is in the range of 1969600Pa to 4596000Pa, there are no air bubbles in the bonding surface, and good bonding conditions are obtained. Next, when the second bonding process is performed using a vacuum bonding device, other embodiments will be referred to FIG. 5 Fig. 5 (a) illustrates the laminated shape of the first birefringent plate 1, the polymer film 2, and the second birefringent plate 3. Fig. 5 (b) is a cross-sectional view of a state of being placed on a vacuum bonding device, and Fig. 5 (c) is a cross-sectional view of a state of being pressed. First, as shown in Fig. 5 (b), press on the lower side A buffer material 5 is disposed on the upper surface of the landing plate 121, 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, and polyethylene plates. Foamed products such as urethane or resin sheets, papers such as high-quality paper, photocopying paper, corrugated paper, dustproof paper, fiber such as kapok, nylon, -22- (19) 1242082 leather such as cowhide, etc. It is softer than metal. Secondly, the adhesive layer on the other side of the first bimolecular film 2 to which the polymer film 2 is bonded is exposed, and the first birefringent plate 1 is induced again by the exposure. 130 1 3 2 is held. At this time, the first birefringent plate 1 and the high score 2 birefringent plate 3 are stacked in the vertical direction, as shown in FIG. 5 (a-shaped first birefringent plate 1 and the same rectangular high The molecular birefringent plate 3 is arranged orthogonally, and the width of the second birefringent plate 3 is narrower than that of the polymer film 2 in the same direction. Pressing the second side plate on the birefringent plate 1213, and the holding unit attached to the polymer of the first birefringent plate 132 is held by a divisive each other face to face configuration. In the arrangement state shown in FIG. 5 (b), the vacuum processing chamber 110 is evacuated, and the driving device that reaches the predetermined true picture drives the lifting shaft 141 to cause it to descend 142 to gradually fall, thereby resisting the induction holding portion 132. The upper end 1 42 resists the plucking force of the lifting pins 1 3 1 to poke upward, and the induction holding portion 1 3 2 is pushed up and down to lower the holding portion 1 3 2 and the first birefringent plate 1 is attached, The second pair of upper pressing plates 1 42 placed against the lower pressing plate 1 2 1 will fold the first double with a predetermined pressure, as shown in FIG. 5 (c). Between the plate 1 and 21, sandwiching the first birefringent plate 1 and the high-scoring material with the adhesive layer of the refractive plate 1 selected as the induction holding part film 2 and the d, the rectangular film 2 and the second Left and right sides of the paper. It is placed on the induced thin film 2 and formed into a vacuum piping of 111 vacancies, and the plate member 1 3 3 is pressed on the upper side without pressing the plate on the upper side so that the induced molecular film 2 is a refractive plate. After 3, the shooting plate 1 is pushed. The 142 and the lower side thin film 2 and the -23-1242082 (20) 2 birefringent plate 3 are 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 M2. As the upper pressure plate 1 42 rises, the induction holding portion 1 3 2 receives the plucking force of the elastic member 1 3 3, and the first birefringent plate 1 on which the second birefringent plate 3 is bonded to the polymer film 2 Hold it up and return to its original position. Next, the vacuum piping 1 1 1 is closed, the atmosphere is introduced into the vacuum processing chamber 1 10, and the pressure is returned to atmospheric pressure. The unillustrated door of the vacuum processing chamber 1 1 0 is opened, and the molecular film 2 in the cylinder 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 case where the cushioning material 5 is arranged between the second birefringent plate 3 and the lower pressing plate 1 2 1 and the case where it is not arranged by experiments. 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 made of a birefringent plate with a size of 50 mm x 50 mm and a thickness of 0.7 mm, and a polycarbonate with an acrylic-based adhesive layer (thickness of about 20 // m) on both sides. (Thickness about 80 // m). -24- (21) 1242082 Other bonding conditions include a bonding temperature of 40 ° C, a pressing pressure of 1960 0 0 Pa, and a pressing time of 3 minutes. [Table 4] Bubble area (mm2) during compression (min.) With buffer material 浜 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 According to this result, when a cushioning material is provided, the pressing time is more than 0.5 minutes to confirm that there is no Air bubbles exist. If no cushioning material is provided, the pressing time must be at least 3 minutes to confirm that no air bubbles are present. This is because the bonding surface can be subjected to uniform pressure application by arranging the buffer material. For example, if the same pressing time is compared, then the doctor 1 can press with uniform pressure, so the existence of air bubbles can be reduced. The adhesion of the adhesive is stronger. The method of bonding the first birefringent plate 1 and the second birefringent plate 3 to both sides of the polymer film 2 using such a vacuum bonding device 100 is performed in a vacuum atmosphere, and the second A cushioning material 5 is arranged between the refractive plate 3 and the lower pressing plate 1 2 1, so that the polymer film 2 and the birefringence • 25-1242082 (22) bubbles can be reliably prevented. 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 pressurizing 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 2500 nm). 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) 1242082 external line blocking filter, the infrared blocking function is added to the optical low-pass filter, which can eliminate the infrared blocking filter. Mirror parts to reduce the number of parts. The infrared blocking chirped wave mirror is a high refractive index layer made of high refractive index dielectrics such as T i 〇 2, N b 2 〇 5, 5 and T a 2 005, and a low refractive index made of Si02, MgF2, etc. The low-refractive-index layer made of a high-density dielectric is a structure in which 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, the refractive index of the film can be controlled stably, The produced film is ideal for ion-assisted vaporization, ion plating, and sputtering methods with small changes over time in the spectral characteristics due to changes in storage and 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 the thin film material. The ion beam generating device ionizes and accelerates the 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 gas ions to form a film. There are APS (Advanced Plasma Source) and EBEP (Electron) Beam Excited Plasma) method, radio frequency (Radio Frequency) direct substrate application method (method of reactive vacuum evaporation under the condition of film formation-27-1242082 (24) high frequency gas plasma generated in the room) and other methods. The sputtering method is a thin film formation 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. Since the polymer film or adhesive is less heat-resistant, film formation at a low temperature of less than 1000 ° C is preferred. 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 film include, for example, Si02, SiO, Zr02, Ti02, TiO, Ti203, Ti205, AI2O3, Ta205, Ce02, MgO, Y2O3, Sn02, MgF, etc. It is used alone or two or more of these. When the multilayer film is formed, it is preferable that the outermost layer is SiO 2. The multilayer film of the inorganic coating may be, for example, the total optical film thickness of the ZrO2 layer and the Si 02 layer from the substrate side; the optical film thickness of the I / 4 and Zr02 layers is λ / 4, and the uppermost layer of the Si02 layer is The optical film thickness is a four-layer structure with λ / 4. Here, λ is the design wavelength, and 5-20 nm is usually used. As a 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 a state where saturation is easy, and the like can be used. Examples of the material of the organic film include, for example, FFP (tetrafluoroethylene-hexafluoropropylene), PTFE (Polytetrafluoroethylene, polytetrafluoroethylene), and ETFE (ethylene-tetrafluoroethylene ( Tetrafluoroethylene storage) Copolymer-28-1242082 (25) materials) etc. 'was 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. Furthermore, 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 the i-th 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 the 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- 1242082 (26) the sub-film and the second A cross-sectional view of the arrangement relationship of the birefringent plates in the vertical direction is (c) a cross-sectional view of a state in which the birefringent plate is being pressed 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 of 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 10 ... vacuum processing chamber 121 ... lower pressing plate 130 ... Induction device 131 ... lift pin 132 ... induction holding portion 1 4 2 ... upper pressing plate -30-