1304137 - * (1) 九、發明說明 Φ _ 【發明所屬之技術領域】 本發明係有關稜鏡之製造方法。 【先前技術】 作爲以光拾波器爲代表之光學系統的構成零件，例如 有偏光光束分光器。偏光光束分光器，係將從光源射出之 雷射光分離爲反射光與透過光的光學元件；反射光或透過 光寺任一^邊之光會向者光碟片’另一*邊則向著用以檢測雷 射光強度的APC( Auto Power Control自動功率控制）受 光元件。偏光光束分光器中反射之反射光，一般是以90° 之角度來反射，故構成偏光光束分光器之偏光分離膜係配 置爲對光軸成45°夾角。從而，作爲偏光光束分光器，係 使用方塊形狀的稜鏡，偏光分離膜則對光軸成45°夾角地 形成於稜鏡上。 製造以特定角度形成有偏光分離膜之光學裝置（棱 鏡）的方法，例如揭示於專利文件1。專利文件1中，係 準備複數相同之板玻璃，將此等板玻璃層積爲階梯狀來得 到層積體之後，切斷層積體做爲分割層積體，反覆進行分 割層積體之層積•切斷，而得到最後的棱鏡。此時，爲了 得到稜鏡內部有以特定角度形成偏光分離膜的光學裝置， 係沿著具有對應偏光分離膜傾斜角之角度的傾斜側壁，使 切斷層積體而成之分割層積體排列爲階梯狀。 〔專利文件1〕日本特開2000- 1 998 1 0號公報 (2) 1304137 【發明內容】 發明所欲解決之課題 然而，形成於最後所製造之稜鏡的介電質多層膜（專 利文件1所謂的偏光分離膜），必須對光之入射面以極高 角度精確度來形成。從而在製造棱鏡時，不得不以極高角 度精確度來形成介電質多層膜。但是上述專利文件1之發 明中，難以滿足稜鏡所要求之較高角度精確度。 亦即專利文件1之發明中，在層積複數板玻璃及分割 層積體時，係於各片板玻璃間塗佈黏著劑來黏著。此時， 各層黏著劑會產生厚度誤差。因爲黏著劑要層積複數層， 故各層之黏著劑會累積厚度誤差。又，因爲反覆進行板玻 璃及分割層積體之層積•切斷，故上述誤差會更加累積， 且切斷時也會產生切斷誤差，故最後製造之棱鏡會含有極 大誤差。更且板玻璃及層積分割體雖然沿著傾斜壁而排列 爲階梯狀，但層積時或切割時會產生切斷誤差，又傾斜壁 本身也有可能產生誤差。 以上之誤差會造成影響，對最後製造之棱鏡內部所形 成之膜的傾斜角，有可能產生極大誤差。從而，無法確保 高精確度之角度精確度，故專利文件1之發明中，極難以 用較高角度精確度將介電質多層膜形成於稜鏡。 因此本發明之目的，係提供一種製造具有較高角度精 確度的稜鏡製造方法。 (3) 1304137 •用以解決課題之手段 _ 本發明之稜鏡之製造方法，係製造以特定角度形成有 介電質多層膜的稜鏡；其特徵係由將平板狀基板亦即大型 基板，以及厚度及寬度尺寸與此大型基板相同而深度尺寸 較上述大型基板爲短之小型基板，其雙面加以硏磨，做出 上述大型基板及上述小型基板雙面之平面度及平行度的， 平板雙面硏磨工程；和在上述平板雙面硏磨工程中被硏磨 之上述大型基板及上述小型基板之雙面中，於任意2個面 B 成膜介電質膜，而形成成膜面與非成膜面的介電質多層膜 成膜工程；和將上述大型基板與上述小型基板，使上述成 膜面與上述非成膜面黏著地來交互黏著的工程，也就是在 寬度方向錯開特定間隔作爲階梯狀，且使上述大型基板之 _ 深度方向兩端作爲基準面而露出地來層積，而得到層積玻 : 璃體的基板黏著工程；和將上述層積玻璃體，在與上述階 梯狀傾斜爲平行之方向，切斷爲上述稜鏡之一邊長度以上 之間隔，而得到複數多重玻璃體的層積玻璃體切斷工程； 1 和在上述多重玻璃體中，將上述層積玻璃體切斷工程所切 斷之2個切斷面做雙面硏磨，做出2個切斷面之平面度及 平行度的多重玻璃體雙面硏磨工程；和將上述層積玻璃 體，在與上述硏磨面爲垂直之方向，切斷爲上述稜鏡之一 邊長度以上之間隔，而得到複數短條玻璃體的多重玻璃體 切斷工程；和以形成於上述短條玻璃體兩端之上述基準面 爲基準，硏磨上述多重玻璃體切斷工程中所切斷之切斷面 的第1短條玻璃體硏磨工程；和以上述第1短條玻璃體硏 (4) 1304137 磨工程所硏磨之面爲基準’硏磨此面之相反面的第2短條 玻璃體硏磨工程；和將上述短條玻璃體硏磨工程所硏磨之 上述短條玻璃體，在與上述多重玻璃體雙面硏磨工程所硏 磨之硏磨面，或上述短條玻璃體硏磨工程所硏磨之硏磨面 爲垂直之方向，以等間隔切斷而得到複數稜鏡的短條玻璃 體切斷工程，所構成。 若依本發明之稜鏡製造方法，則在層積大型基板與小 型基板時，在深度方向之大型基板兩端會層積爲比小型基 板更突出。大型基板與小型基板係預先進行有雙面之表面 硏磨，做出平面度及平行度，故該被硏磨之面會做爲基準 面而經常露出。然後以基準面爲基準進行硏磨，可做出較 高角度精確度。 在此，大型基板與小型基板雖進行有雙面之表面硏 磨，但之後會於大型基板之兩面成膜介電質多層膜，而小 型基板之兩面則不形成介電質多層膜。此時。露出之基準 面（大型基板中突出之面）係經常成膜有介電質多層膜， 故可用成膜有介電質多層膜之面爲基準來進行硏磨。從 而，可製造對成膜有介電質多層膜之面具有極高精確度之 角度精確度的稜鏡。 又，被表面硏磨之大型基板與小型基板的雙面中，不 在大型基板雙面而在小型基板雙面成膜介電質多層膜者， 也可適用本發明。此時，因爲大型基板沒有成膜介電質多 層膜，故露出之基準面經常都沒有成膜介電質多層膜。從 而，成爲將未成膜有介電質多層膜之面作爲基準面來進行 -8 - (5) 1304137 硏磨，此時最後所製造之稜鏡中成膜有介電質多層膜之 面，會是與基準面經由黏著劑相對之面。因此，必須高精 確度管理黏著劑厚度，而比起將上述成膜有介電質多層膜 之面作爲基準面者，有時會降低些許角度精確度。但是， 即使不用成膜有介電質多層膜之面作爲基準面，使用具有 高精確度之平面度及平行度的基準面作爲基準來硏磨一點 並未改變，故此時也可製造具有較高角度精確度的稜鏡。 又，在大型基板及小型基板之一側表面分別成膜介電 質多層膜者，也可適用本發明。此時，露出之基準面中， 1面成膜有介電質多層膜，但其相反面則未成膜有介電質 多層膜。從而具有成膜有介電質多層膜之基準面的短條玻 璃體，與具有未成膜之基準面的短條玻璃體，會分別以一 半的比例來產生。但是，未成膜有介電質多層膜之面雖然 也會有些許角度精確度降低，但是以雙面硏磨後之表面爲 基準面來進行硏磨者仍無改變，故可製造具有較高角度精 確度的稜鏡。 另外，此時角度精確度會產生些許不一致。因此雖然 於大型基板及小型基板之一側表面分別成膜有介電質多層 膜，但是小型基板之一側表面係全面進行。然後，於大型 基板之一側表面中與小型基板相同的範圍（構成層積玻璃 體時，大型基板範圍中與小型基板接合之範圍相同的範 圍）內成膜介電質多層膜。因此，因爲經常以未成膜有介 電質多層膜的面爲基準面來硏磨，故可消除上述不一致。 (6) 1304137 -發明效果 . 本發明之稜鏡製造方法，可製造具有較高角度精確度 的稜鏡。 【實施方式】 以下，依據第1圖之流程圖說明本發明之實施方式。 第2圖，係最後所製造之稜鏡1 0。本實施方式之稜鏡 10，係一邊長度爲PL之方塊型光學元件，並使介電質多 層膜3對光軸以45°之角度來形成。在此，本實施方式中 稜鏡10之各面的對角線長度（形成有介電質多層膜3之 面的長邊）係定義爲稜鏡1〇之對角線長度PD ( = PLx ，2)。又，稜鏡10之各面成膜有具有反射防止功能之反 射防止膜。 一開始，如第3圖所示，準備複數片具有不同形狀之 2種平板狀基板（玻璃基板等基板）。第3圖（a )中’表 示長邊（寬度）具有LX1，短邊（深度）具有LY1之長 度，厚度爲LZ1的大型基板1。第3圖（b)中，表示寬 度具有LX1，深度具有LY2 ( LY2< LY1 )之長度，厚度 爲L Z1的小型基板2。另外’最後所製造之稜鏡1 0 ’係進 行大型基板1及小型基板2之層積•切斷來產生’故大型 基板1之寬度（LX1 )、深度（LY1 )、厚度（LZ1 )及小 型基板2之寬度（LX1)、深度（LY2)、厚度（LZ1) ’ 全都使用比棱鏡10 —邊之長度PL更長（1//~ 2)倍者。 作爲最初工程，係以硏磨等將所準備之複數片大型基 -10- (7) 1304137 板1及小型基板2的雙面做表面硏磨（步驟s丨）。藉由 此表面硏磨’大型基板1及小型基板2之雙面可做出較高 平面度及平行度。然後在大型基板1之雙面成膜介電質多 層膜3 (步驟S 2 )。此時，本實施方式中，如第3圖 (a)及第3圖（b)所示，將大型基板1中成膜有介電質 多層膜3之雙面定義爲成膜面C，而小型基板2之雙面則 定義爲非成膜面N。 其次，將大型基板1與小型基板2交互層積複數片， 而得到層積玻璃體4 (步驟S 3 )。層積玻璃體4，係將大 型基板1與小型基板2以黏著材料黏接，而如第4圖所 示，使各個基板之成膜面C與非成膜面N黏接地來黏貼層 積。第5圖（a)及（b)，係第4圖之正面圖及側面圖； 大型基板1與小型基板2，係在寬度方向以特定間隔錯開 而層積爲整體成爲階梯狀，在深度方向則使大型基板1兩 端比小型基板2突出地來層積。另外第4圖、第5圖 (a)及第5圖（b)，係表示層積了 3片大型基板1、2 片小型基板2的層積玻璃體4 ;當然，所層積之基板片數 可以任意設定。如第5圖（a )所示，大型基板1與小型 基板2在寬度方向，係分別錯開與基板厚度LZ 1相同之間 隔來層積。從而，層積玻璃體4之上述階梯狀的傾斜角係 形成45°。然後從第4圖及第5圖（b )可得知，大型基板 1之兩端係分別比小型基板2做相等突出（亦即如第5圖 (b )所示，兩端僅等量突出「l/2x ( LY1 — LY2 )」的份 量），故成膜面C中突出之部分會露出。在此，於本實施 -11 . (8) 1304137 方式中’將成膜面C中露出之部分定義爲基準面B (如第 5圖（b)所示’基準面b形成於大型基板1中突出部分 的雙面）。成膜面C做出有較高平面度及平行度，基準面 B係成膜面C之一部分，故基準面b也做出有較高平面度 及平行度。從後續工程可得知，藉由將基準面B作爲基準 來進行硏磨加工’可得到介電質多層膜3以極高角度精確 度（45°)被形成的稜鏡10。這點於後敘述。 然後將層積玻璃體4沿著第4圖之虛線，在與上述階 梯狀傾斜平行之方向，或是以端面爲基準成45°的角度， 於特定間隔以線鋸等進行切斷（步驟S4 )。藉由此切 斷，可複數得到如第6圖（a)所示之多重玻璃體5。此時 層積玻璃體4之切斷間隔，係如第4圖所示，在棱鏡10 之對角線PD加上硏磨量α者。這點於後敘述。 在此，在後述工程可得知，在步驟S4中產生多重玻 璃體5之時間點，多重玻璃體5之切斷面5Α、5Β (切斷 層積玻璃體4時之2個切斷面：第6圖（a)表示爲上 面、下面）若具有較高平面度及平行度，則切斷面5A、 5B會構成稜鏡1〇之一面及其相反面。但是以步驟S4切 斷之後，並不能保證多重玻璃體5之切斷面5A、5B的平 面度。因此係硏磨多重玻璃體5之切斷面5A、5B，如第6 圖（b)所示，形成硏磨面5C、5D (步驟S5)。藉由該 硏磨，硏磨面5C、5D可做出較高平面度及平行度，而可 分別構成稜鏡1 〇之一面及其相反面。此時’係使硏磨後 之多重玻璃體5之硏磨面5 C與5 D的間隔，成爲稜鏡10 -12- (9) 1304137 之一邊長度PL地，來進行多重玻璃體5的硏磨。藉此， 可嚴格構成稜鏡1 〇之兩個面。 然而，多重玻璃體5藉由步驟S5之硏磨，其厚度 (硏磨面5 C與5 D的間隔）會變薄。因此步驟S 4中層積 玻璃體4之切斷，要先預測硏磨之硏磨量的份量，預先留 下空間來進行切割。具體來說，就是在稜鏡1 0之對角線 長度PD具有加上硏磨量α的間隔，來進行層積玻璃體4 之切斷，藉此硏磨該硏磨量，做出多重玻璃體5的平面 度。 另外步驟S4中，層積玻璃體4之切斷並非在稜鏡1 〇 之一邊長度PL具有加上硏磨量α的間隔，而是在稜鏡1〇 之對角線長度PD具有加上硏磨量α的間隔，來進行切 斷，其理由係多重玻璃體5之端面中，短邊長度對應稜鏡 10之對角線長度PD。 然後，第6圖（b)所示之硏磨後多重玻璃體5的端 面5E、5F，係由層積玻璃體4之最上段及最下段之大型 基板1或小型基板2的一部分所構成。構成層積玻璃體4 之大型基板1及小型基板2，在步驟S1中做出有高精確 度之平面度及平行度，故可以用多重玻璃體 5的端面 5E、5F來作爲基準。從而，以端面5E、5F作爲基準來硏 磨切斷面5A、5B，可以用45°之較高角度精確度，來形成 硏磨面5C、5D與成膜有介電質多層膜3之成膜面C所夾 的角度。 其次，於硏磨後之多重玻璃體5的硏磨面5 C、5 D成 -13- (10) 1304137 膜反射防止膜（步驟S6 )。如上所述，多重S 硏磨面5 C、5 D，係形成稜鏡1 〇之一面者，故 成膜反射防止膜。因爲從多重玻璃體5會產: 10，故若預先成膜反射防止膜，則可一次成膜ί 的反射防止膜。 然後，將成膜有反射防止膜之多重玻璃體 圖（b)之虛線所示，在與硏磨面5C、5D垂直 定間隔切斷（步驟S 7 )。藉由此切斷，來複 圖（a )所τρ：之短條玻璃體6。 在此，進行多重玻璃體5之切斷時，係與 璃體4之情況相同，不保證切斷面6A、6B ( 璃體5時之2個切斷面：第7圖（a)中表示 相反面）的平面度及平行度。然後切斷面6A、 證有較高平面度及平行度，則會構成稜鏡10 相反面。但是切斷多重玻璃體5時，並不能保 平行度，因此爲了硏磨切斷面6A、6B來做出 行度，短條玻璃體6必須考慮硏磨量來產生。 多重玻璃體5時，係在稜鏡10之一邊長度PL 磨量/3之間隔來進行切斷。但是，步驟S 7之 5之切斷，係在與稜鏡1〇之面平行的方向來進 在稜鏡10之對角線長度PD，而是在棱鏡10 PL具有加上硏磨量0之間隔來進行切斷。 然而，雖然必須進行切斷面6A、6B之硏 磨後雙面的平面度及平行度，但此時必須使硏 :璃體5之 在此時間點 生複數稜鏡 I數稜鏡10 5，如第6 之方向以特 敎產生第7 切斷層積玻 切斷多重玻 爲側面及其 6B如果保 之一面及其 證平面度及 平面度及平 從而，切斷 具有加上硏 多重玻璃體 行，故不是 之一邊長度 磨來做出硏 磨後之雙面 -14- (11) 1304137 對成膜面C嚴格成爲4 5 °地來進行硏磨。因此將露 條玻璃體6兩端之基準面B，作爲基準來進行硏磨 面B係成膜面C之一部分，而因爲成膜面c做出 平面度及平行度，故若以基準面B爲基準來進行硏 硏磨後之面可以與成膜面C嚴格形成45。的角度。 一開始如第7圖（b )所示，進行短條玻璃體 斷面6A的硏磨而得到硏磨面6C (步驟S8:第1 璃體硏磨工程）。在第8圖表示進行此硏磨時所使 模的一例。如第8圖（a )所示，工模7係在兩側 壁部7S，各個側壁部7S複數形成有用以放置短條 6之兩端的放置部7P。放置部7P形成有切口部， 口部保持有短條玻璃體6之突出部P (短條玻璃體 端中有基準面B露出之部分）。放置部7P之切口 垂直面7PA與斜面7PB所構成，斜面7PB與工模 面7B的角度係嚴格構成45°。又，垂直面7PA與斜 的角度係嚴格構成45°。然後，放置部7P之切口部 等腰三角形的形狀，垂直面7PA之高度比稜鏡1〇 長度PL要小。又，工模7之放置部7P的形狀，係 度保持角度者，而設置於工模7兩側之側壁部7S 間隔，係和小型基板2之深度方向尺寸LY2幾乎相 際上，係使得可以放置短條玻璃體6地’構成爲比 向尺寸LY2更長些許）者。另外如第8圖（b )所 置部7P係爲了保護放置於放置部7P之短條玻璃體 出部P邊緣，而形成有脫離溝7S。 出於短 。基準 有較高 磨，則 6之切 短條玻 用之工 設置側 玻璃體 於該切 6之兩 部係由 7之底 面7PB 係直角 之一邊 高精確 之‘間的 同（實 深度方 不，放 6的突 -15- (12) 1304137 於該放置部7P放置短條玻璃體6之突出部P。第8 圖（b )係表示將短條玻璃體6之切斷面6A放置爲上面者 的剖面圖。短條玻璃體6之突出部P中，係使基準面B碰 觸放置部7P之斜面7PB，而硏磨面5D碰觸垂直面7PA地 來放置。放置部7P之斜面7PB與工模7之底面7B之夾 角係高精確度地保證爲4 5 °的角度，短條玻璃體6之基準 面B與硏磨面5D的夾角也是45°。從而，短條玻璃體6 之突出部P會嚴密嵌合於放置部7P。另一方面，短條玻 璃體6之切斷面6 A與6 B之間隔，係形成爲比稜鏡1 〇之 一邊長度PL要長些許，故切斷面6A會成爲比側壁部7S 之上面7U稍微隆起的狀態。因此硏磨隆起之稜鏡1 〇的切 斷面6A，該硏磨進行到等於棱鏡1〇之一邊長度PL爲 止。此時，作爲目標而硏磨到基準面B之稜線位置爲止， 藉此可在等於稜鏡10之一邊長度PL爲止進行硏磨。藉此 如第7圖（b )所示，可得到短條玻璃體6中，曾經是大 型基板1之部分其剖面爲等腰直角三角形（包夾直角之兩 邊爲PL之長度）的短條形狀者。 其次，進行切斷面6B之硏磨（第2短條玻璃體硏 磨：步驟S9)。在此時間點，短條玻璃體6中，硏磨面 5C、5D及6C係對成膜面C以較高角度精確度修飾。因此 以硏磨面6C爲基準面硏磨剩下之切斷面6B，而如第7圖 (c)所示，形成硏磨面6D。另外，硏磨面5C、5D及6C 係全都對成膜面C以較高角度精確度修飾，故不限於硏磨 面6C，可以用任一個面、任兩個面，或以所有面爲基準 -16- (13) 1304137 來形成硏磨面6D。由上所述，硏磨面5C、5D、6C、6D 等所有面都會形成稜鏡10之一面，而可以較高角度精確 度修飾短條玻璃體6。 另外’上述工模7不過是一個例子，本發明之主旨係 以成膜面C之一部分，亦即以基準面B作爲基準來進行硏 磨，故工模7不限於第8圖所示者。從而，只要是可用基 準面B爲基準來硏磨者，則可適用任意者。然後在進行切 斷面6B之硏磨時，雖說明以硏磨面5C、5D及6C爲基準 來進行硏磨者，但亦可準備可用基準面B爲基準來硏磨的 工模，以該工模來進行切斷面6B之硏磨。 然後硏磨面6C及6D，係尙未成膜有反射防止膜，故 於兩面成膜反射防止膜（步驟S 1 0 )，然後如第7圖（c ) 之虛線所示，在與硏磨面5C、5D、6C、6D垂直之方向以 等間隔進行切斷（步驟S 1 1 )。此時之切斷間隔，係等於 棱鏡1 〇之一邊長度PL地來進行切斷。藉此，可形成如第 2圖所示之一邊長度爲PL，具有45°角度之介電質多層膜 3，而可得到具有較高角度精確度的稜鏡10。 如以上所說明，本發明係準備寬度及厚度相同且深度 尺寸不同的2種基板，亦即大型基板與小型基板，分別於 1面成膜介電質多層膜，將大型基板與小型基板交互層積 複數片。此時，使大型基板之兩端在深度方向比小型基板 更突出地來層積，藉此使成膜有介電質多層膜之面的一部 分經常露出爲基準面’故藉由以此基準面爲基準來進行硏 磨，可做出較高角度精確度。 -17- (14) 1304137 另外，上述實施方式之棱鏡10，係說明具有立方體形 狀，而成膜有介電質多層膜3之面爲45°者，因此在接合 大型基板1與小型基板2時，係在寬度方向錯開與基板厚 度LZ1相同之間隔來層積。亦即藉由在寬度方向錯開 LZ 1，上述階梯狀之角度可形成與4 5 °。但若在寬度方向錯 開不爲LZ1之間隔，則可將上述階梯狀之角度形成與45° 不同之角度。在步驟S4中，雖在與上述階梯狀傾斜爲平 行的方向來切斷層積玻璃體4，但如果階梯狀之角度形成 爲與45°不同的角度，則形成於最後所製造之棱鏡10的介 電質多層膜3，其所形成之面可以作爲與45°不同的角 度。又，也可將稜鏡10之形狀作爲與立方體不同者。另 外在此時，雖然是與45°不同的角度，但是可製造以較高 角度精確度在稜鏡10形成有介電質多層膜3者。 又，本發明中雖舉例說明光拾波器裝置，但並不限定 於此，只要是對方塊狀稜鏡以特定角度成膜有介電質多層 膜者，可適用任意物品。例如作爲構成進行顏色分解•顏 色合成之液晶投影機的光學元件，亦可適用分色稜鏡。分 色稜鏡也使用方塊形狀之稜鏡，藉由入射光波長而區別爲 反射·透射之分色膜，係對光路以45°之角度形成。從 而，該分色稜鏡亦可適用本發明。 【圖式簡單說明】 〔第1圖〕表示本發明之處理流程的流程圖 〔第2圖〕稜鏡之立體圖 -18- (15) (15)1304137 〔第3圖〕大型基板及小型基板之立體圖 〔第4圖〕層積玻璃體之立體圖 〔第5圖〕層積玻璃體之正面圖及側面圖 〔第6圖〕多重玻璃體之立體圖 〔第7圖〕短條玻璃體之立體圖 〔第8圖〕工模之立體圖及放大圖 【主要元件符號說明】 1 :大型基板 2 :小型基板 3 :介電質多層膜 4 :層積玻璃體 5 :多重玻璃體 6 :短條玻璃體 7 :工模 B :基準面 C :成膜面 N :非成膜面1304137 - * (1) IX. Description of the invention Φ _ [Technical field to which the invention pertains] The present invention relates to a method of manufacturing a crucible. [Prior Art] As a component of an optical system typified by an optical pickup, for example, a polarizing beam splitter is used. The polarized beam splitter is an optical component that separates the laser light emitted from the light source into a reflected light and a transmitted light; the reflected light or the light passing through any of the light temples is directed toward the other side of the optical disc. An APC (Auto Power Control) light-receiving element that detects the intensity of laser light. The reflected light reflected by the polarizing beam splitter is generally reflected at an angle of 90°, so that the polarizing separation film constituting the polarizing beam splitter is arranged at an angle of 45° with respect to the optical axis. Therefore, as the polarizing beam splitter, a square-shaped crucible is used, and the polarized light separation film is formed on the crucible at an angle of 45 to the optical axis. A method of manufacturing an optical device (prism) in which a polarizing separation film is formed at a specific angle is disclosed, for example, in Patent Document 1. In Patent Document 1, a plurality of the same plate glass is prepared, and the plate glass is laminated in a step shape to obtain a laminate, and then the layered body is cut as a split laminate, and the laminated body of the split laminate is repeatedly performed. • Cut off and get the final prism. At this time, in order to obtain an optical device in which a polarizing separation film is formed at a specific angle inside the crucible, the divided laminated body formed by cutting the laminated body is arranged along the inclined side wall having an angle corresponding to the inclination angle of the polarizing separation film. Stepped. [Patent Document 1] JP-A-2000- 1 998 1 0 (2) 1304137 SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION However, a dielectric multilayer film formed in the last manufactured ruthenium (Patent Document 1) The so-called polarized light separation film must be formed with an extremely high angular accuracy to the incident surface of the light. Thus, in the manufacture of prisms, dielectric multilayer films have to be formed with extremely high angular accuracy. However, in the invention of the above Patent Document 1, it is difficult to satisfy the higher angular accuracy required by 稜鏡. In the invention of Patent Document 1, when a plurality of sheets of glass and a laminated body are laminated, an adhesive is applied between the sheets of the sheets to adhere thereto. At this time, the thickness error of each layer of the adhesive is generated. Since the adhesive is to be laminated in a plurality of layers, the adhesive of each layer accumulates thickness errors. Further, since the lamination and cutting of the plate glass and the split laminate are repeated, the above-mentioned errors are more accumulated, and a cutting error occurs even when the cutting is performed, so that the prism manufactured finally contains an extremely large error. Further, although the plate glass and the laminated body are arranged in a stepped shape along the inclined wall, a cutting error occurs during lamination or cutting, and the inclined wall itself may cause an error. The above error will have an effect, and the tilt angle of the film formed inside the finally manufactured prism may cause a great error. Therefore, the accuracy of the angle of high precision cannot be ensured. Therefore, in the invention of Patent Document 1, it is extremely difficult to form the dielectric multilayer film on the crucible with higher angular accuracy. It is therefore an object of the present invention to provide a method of manufacturing a crucible having a high degree of precision. (3) 1304137 - Means for Solving the Problem - The manufacturing method of the present invention is to manufacture a crucible having a dielectric multilayer film formed at a specific angle; and the feature is that a flat substrate, that is, a large substrate, And a small substrate having the same thickness and width as the large substrate and having a smaller depth than the large substrate, and honing on both sides to make the flatness and parallelism of the large substrate and the small substrate on both sides, the flat plate a double-sided honing process; and on both sides of the large substrate and the small substrate honed in the flat double-sided honing process, a dielectric film is formed on any two faces B to form a film-forming surface a film forming process of a dielectric multilayer film having a non-film-forming surface; and a process of mutually adhering the large-sized substrate and the small-sized substrate to adhere the film-forming surface to the non-film-forming surface, that is, staggered in the width direction The specific interval is a stepped shape, and both ends of the large substrate in the depth direction are exposed as a reference surface to be laminated, thereby obtaining a laminated glass: a substrate adhesion process of the glass; and the layer is The laminated glass body is cut into a space of a length equal to or longer than the length of one side of the step in the direction parallel to the stepped inclination, thereby obtaining a laminated glass body cutting process of a plurality of multiple glass bodies; 1 and in the multiple glass body described above The two cut surfaces cut by the laminated glass body cutting process are double-sided honed, and the multiple glass double-sided honing works of the flatness and parallelism of the two cut surfaces are made; and the laminated glass body is a multiplexed glass body cutting process for obtaining a plurality of short strips of glass in a direction perpendicular to the honing surface, at a distance equal to or longer than one of the lengths of the ridges; and the reference formed at both ends of the short glass body The first short-length vitreous honing work for honing the cut surface cut in the above-mentioned multiple vitreous cutting process; and the surface honed by the first short vitreous 硏(4) 1304137 grinding project The second short strip vitreous honing work for the opposite side of the surface; and the short strip vitreous honed by the short strip vitreous honing project, in combination with the above multiple vitreous body The honing surface of the honing project, or the honing surface of the short-strip vitreous honing project, which is perpendicular to the direction, is cut at equal intervals to obtain a plurality of short-striped vitreous cutting works. Composition. According to the crucible manufacturing method of the present invention, when a large substrate and a small substrate are laminated, the both ends of the large substrate in the depth direction are laminated more prominently than the small substrate. The large substrate and the small substrate are honed on both sides in advance, and the flatness and parallelism are made. Therefore, the surface to be honed is often exposed as a reference surface. Then honing with the reference plane as a reference for higher angle accuracy. Here, although the large substrate and the small substrate are subjected to double-sided surface honing, the dielectric multilayer film is formed on both surfaces of the large substrate, and the dielectric multilayer film is not formed on both surfaces of the small substrate. at this time. The exposed reference surface (the surface that protrudes in the large substrate) is often formed with a dielectric multilayer film, so that the surface can be honed by the surface on which the dielectric multilayer film is formed. Therefore, it is possible to manufacture an ytterbium having an extremely high degree of accuracy in film forming a surface of a dielectric multilayer film. Further, in the double-sided surface of the large substrate and the small substrate which are surface-honed, the present invention can also be applied without forming a dielectric multilayer film on both surfaces of the small substrate on both sides of the large substrate. At this time, since the large-sized substrate is not formed into a dielectric multilayer film, the exposed dielectric surface is often not formed into a dielectric multilayer film. Therefore, -8 - (5) 1304137 honing is performed using the surface of the dielectric multilayer film which is not formed as a reference surface, and at this time, the film formed in the last yttrium has a dielectric multilayer film. It is the surface opposite to the reference surface via the adhesive. Therefore, it is necessary to manage the thickness of the adhesive with high precision, and sometimes the angle accuracy is lowered as compared with the case where the surface of the dielectric film having the dielectric film is formed as a reference surface. However, even if the surface of the dielectric multilayer film is not formed as a reference surface, the use of a reference surface having a high degree of flatness and parallelism as a reference does not change, so that it can be manufactured at a higher time. The accuracy of angular accuracy. Further, the present invention can also be applied to a film on which a dielectric multilayer film is formed on one side surface of a large substrate and a small substrate. At this time, in the exposed reference surface, a dielectric multilayer film was formed on one surface, but a dielectric multilayer film was not formed on the opposite surface. Therefore, the short glass body having the reference surface on which the dielectric multilayer film is formed and the short glass body having the unformed reference surface are produced in a ratio of one half. However, although the surface of the dielectric multilayer film is not formed, although the angle accuracy is lowered, the surface after the double-sided honing is used as the reference surface for the honing, the tempering is still unchanged, so that a higher angle can be manufactured. The accuracy of the flaws. In addition, the angular accuracy will cause some inconsistency. Therefore, although a dielectric multilayer film is formed on one side surface of one of the large substrate and the small substrate, the side surface of one of the small substrates is entirely performed. Then, a dielectric multilayer film is formed in the same surface of one of the large substrates in the same range as the small substrate (when the laminated glass is formed, the same range as the small substrate is bonded in the large substrate range). Therefore, since the surface on which the dielectric multilayer film is not formed is often honed as a reference surface, the above inconsistency can be eliminated. (6) 1304137 - Effect of the invention The crucible manufacturing method of the present invention can produce crucible having a high angular accuracy. [Embodiment] Hereinafter, an embodiment of the present invention will be described based on a flowchart of Fig. 1. Figure 2 is the last manufactured 稜鏡10. The crucible 10 of the present embodiment is a block type optical element having a length of PL, and the dielectric multilayer film 3 is formed at an angle of 45 to the optical axis. Here, in the present embodiment, the diagonal length of each face of the crucible 10 (the long side of the face on which the dielectric multilayer film 3 is formed) is defined as the diagonal length PD of 稜鏡1〇 (= PLx , 2). Further, each of the faces of the crucible 10 is formed with a reflection preventing film having a reflection preventing function. Initially, as shown in Fig. 3, a plurality of flat substrates (substrates such as glass substrates) having different shapes are prepared. In Fig. 3(a), 'the large substrate 1 having a long side (width) having LX1, a short side (depth) having a length of LY1, and a thickness LZ1 is shown. In Fig. 3(b), a small substrate 2 having a width of LX1 and a length of LY2 (LY2 < LY1) and a thickness of L Z1 is shown. In addition, 'the last manufactured 稜鏡1 0' is to laminate and cut the large substrate 1 and the small substrate 2 to generate the width (LX1), depth (LY1), thickness (LZ1) and small size of the large substrate 1. The width (LX1), the depth (LY2), and the thickness (LZ1)' of the substrate 2 are all longer than the length PL of the prism 10 (1//~2) times. As an initial work, the two sides of the plurality of large-sized base-10-(7) 1304137 plates 1 and the small substrate 2 prepared by the honing are surface honed (step s). By this surface honing, both sides of the large substrate 1 and the small substrate 2 can achieve higher flatness and parallelism. Then, a dielectric multilayer film 3 is formed on both surfaces of the large substrate 1 (step S2). At this time, in the present embodiment, as shown in FIGS. 3( a ) and 3 ( b ), the both sides of the dielectric substrate 3 in which the dielectric multilayer film 3 is formed in the large substrate 1 are defined as the film formation surface C, and The both sides of the small substrate 2 are defined as a non-film formation surface N. Next, the large substrate 1 and the small substrate 2 are alternately laminated to obtain a laminated glass body 4 (step S3). In the laminated glass body 4, the large substrate 1 and the small substrate 2 are adhered by an adhesive material, and as shown in Fig. 4, the film formation surface C of each substrate is adhered to the non-film formation surface N to adhere to the laminate. Fig. 5 (a) and (b) are a front view and a side view of Fig. 4; the large substrate 1 and the small substrate 2 are staggered at a predetermined interval in the width direction, and are stacked in a stepped manner as a whole, in the depth direction. Then, both ends of the large substrate 1 are stacked to protrude from the small substrate 2. In addition, Fig. 4, Fig. 5(a) and Fig. 5(b) show a laminated glass body 4 in which three large substrates and two small substrates 2 are laminated; of course, the number of laminated substrates Can be set freely. As shown in Fig. 5(a), the large substrate 1 and the small substrate 2 are stacked in the same width direction as the substrate thickness LZ1. Thereby, the above-described stepped inclination angle of the laminated glass body 4 is formed at 45°. Then, as can be seen from Fig. 4 and Fig. 5(b), the two ends of the large substrate 1 are respectively protruded more than the small substrate 2 (i.e., as shown in Fig. 5(b), the ends are only equally protruded. "1/2x ( LY1 - LY2 )"), so that the protruding portion of the film formation surface C is exposed. Here, in the present embodiment -11. (8) 1304137, the portion exposed in the film formation surface C is defined as the reference plane B (as shown in Fig. 5(b), the reference plane b is formed in the large substrate 1. The two sides of the protruding part). The film formation surface C is made to have a high degree of flatness and parallelism, and the reference surface B is a part of the film formation surface C, so that the reference surface b is also made to have a high degree of flatness and parallelism. As is apparent from the subsequent work, the honing process is performed by using the reference plane B as a reference, and the crucible 10 in which the dielectric multilayer film 3 is formed with extremely high angular accuracy (45°) can be obtained. This will be described later. Then, the laminated glass body 4 is cut along a broken line in FIG. 4 in a direction parallel to the stepped inclination or at an angle of 45° on the basis of the end surface, and cut by a wire saw or the like at a specific interval (step S4). . By this cutting, the multiple vitreous bodies 5 as shown in Fig. 6(a) can be obtained in plural. At this time, the cutting interval of the laminated glass body 4 is as shown in Fig. 4, and the amount of honing is added to the diagonal line PD of the prism 10. This will be described later. Here, in the later-described process, the time at which the multiple vitreous bodies 5 are generated in the step S4, the cut surfaces of the multiple glass bodies 5, 5Α, 5Β (the two cut surfaces when the laminated glass bodies 4 are cut: Fig. 6 ( a) indicated as upper and lower), if it has a high degree of flatness and parallelism, the cut surfaces 5A, 5B will constitute one side of the 稜鏡1〇 and its opposite side. However, after the cutting in step S4, the flatness of the cut faces 5A, 5B of the multiple glass body 5 cannot be ensured. Therefore, the cut surfaces 5A and 5B of the multiple glass bodies 5 are honed, and the honing surfaces 5C and 5D are formed as shown in Fig. 6(b) (step S5). By this honing, the honing surfaces 5C, 5D can be made to have a higher degree of flatness and parallelism, and can constitute one side of the 稜鏡1 及其 and the opposite side thereof, respectively. At this time, the interval between the honing surfaces 5 C and 5 D of the multiplexed glass body 5 after honing is 之一10 -12 - (9) 1304137 one side length PL, and the doubling of the multiple glass body 5 is performed. Thereby, the two faces of 稜鏡1 〇 can be strictly formed. However, the thickness of the multiple vitreous body 5 by the honing in the step S5 (the interval between the honing surfaces 5 C and 5 D) becomes thin. Therefore, in the step S4, the cut of the laminated glass body 4 is first predicted by the amount of the honing amount of the honing, and the space is reserved in advance to perform the cutting. Specifically, the diagonal length PD of the 稜鏡10 has an interval of the honing amount α to cut the laminated glass body 4, thereby honing the honing amount, and making the multiple vitreous body 5 Flatness. In addition, in step S4, the cutting of the laminated glass body 4 is not at the interval of one side of the 稜鏡1 PL, and the interval of the honing amount α is added, but the diagonal length PD of the 稜鏡1〇 is added with honing. The reason for the interval of the amount α is to cut off, because the length of the short side corresponds to the diagonal length PD of the crucible 10 in the end faces of the multiple vitreous bodies 5. Then, the end faces 5E and 5F of the honed multi-glass body 5 shown in Fig. 6(b) are composed of a part of the large-sized substrate 1 or the small-sized substrate 2 of the uppermost and lowermost stages of the laminated glass body 4. The large substrate 1 and the small substrate 2 constituting the laminated glass body 4 have high degree of flatness and parallelism in the step S1, so that the end faces 5E and 5F of the multiple glass body 5 can be used as a reference. Therefore, the cut surfaces 5A and 5B are honed with the end faces 5E and 5F as a reference, and the honing surfaces 5C and 5D and the film-formed dielectric multilayer film 3 can be formed with a high angular accuracy of 45°. The angle between the film surface C. Next, the honing surfaces 5 C, 5 D of the multiple vitreous bodies 5 after honing are formed into a -13-(10) 1304137 film anti-reflection film (step S6). As described above, the multiple S honing surfaces 5 C and 5 D are formed on one side of the 稜鏡 1 ,, so that the film reflection preventing film is formed. Since the multi-glass body 5 is produced: 10, if the anti-reflection film is formed in advance, the anti-reflection film of ί can be formed at one time. Then, as shown by the broken line of the multiple glass body (b) in which the antireflection film is formed, it is cut at a predetermined interval from the honing surfaces 5C and 5D (step S7). By this cutting, the short glass body 6 of τρ: is shown in (a). Here, when the dicing of the multiple glass bodies 5 is performed, the cut surfaces 6A and 6B are not secured as in the case of the glass body 4 (two cut surfaces in the case of the glass body 5: the opposite is shown in Fig. 7(a)) Flatness and parallelism. Then, the cut surface 6A, which has a high degree of flatness and parallelism, constitutes the opposite side of the 稜鏡10. However, when the multi-glass body 5 is cut, the parallelism is not maintained. Therefore, in order to honing the cut surfaces 6A and 6B to make a degree of progress, the short glass body 6 must be produced in consideration of the amount of honing. In the case of the multiple vitreous body 5, the cutting is performed at an interval of one side length PL of the crucible 10/3. However, the cutting of step S7 is carried out in the direction parallel to the plane of the crucible 1〇 in the diagonal length PD of the crucible 10, but in the prism 10 PL with the addition of the grinding amount 0. Cut off at intervals. However, although it is necessary to perform the flatness and the parallelism of the double-sided surface after the honing of the cut surfaces 6A, 6B, at this time, it is necessary to make the 硏: the glass body 5 at the time point to generate a plurality of 稜鏡I number 稜鏡10 5, For example, in the direction of the sixth direction, the seventh cut layer of glass is cut to cut the multiple glass into the side and its 6B, if one side is protected and its flatness and flatness are flat, the cut and the multiple vitreous lines are added. Therefore, it is not one side of the length of the grinding to make the double-sided 14- (11) 1304137 honing the film-forming surface C strictly to 45 °. Therefore, the reference surface B at both ends of the exposed glass body 6 is used as a reference for the honing surface B as one of the film forming surfaces C, and since the film forming surface c is flat and parallel, the reference plane B is used. The surface after the honing by the reference can be formed strictly with the film formation surface C by 45. Angle. At the beginning, as shown in Fig. 7(b), the honing surface 6C is obtained by honing the short glass body section 6A (step S8: first glazing process). An example of the mode of the honing is shown in Fig. 8. As shown in Fig. 8(a), the die 7 is formed on both side wall portions 7S, and each of the side wall portions 7S is formed in plural to form a placing portion 7P for placing both ends of the short strip 6. The placement portion 7P is formed with a notch portion, and the projection portion P of the short glass body 6 is held at the mouth portion (the portion of the short glass body end where the reference surface B is exposed). The slit of the placement portion 7P is composed of a vertical surface 7PA and a slope 7PB, and the angle between the slope 7PB and the mold surface 7B is strictly 45°. Further, the vertical plane 7PA and the oblique angle are strictly formed at 45 degrees. Then, the shape of the notched portion of the placing portion 7P is an isosceles triangle, and the height of the vertical surface 7PA is smaller than the length PL of the 稜鏡1〇. Further, the shape of the placement portion 7P of the mold 7 is maintained at an angle, and the side wall portions 7S provided on both sides of the mold 7 are spaced apart from each other in the depth direction dimension LY2 of the small substrate 2, so that The short glass body 6 is placed 'configured to be slightly longer than the size LY2). Further, the portion 7P provided in Fig. 8(b) is formed with a separation groove 7S for protecting the edge of the short glass body portion P placed on the placement portion 7P. Out of short. The reference has a higher grinding, then the 6-cut short strip glass is used to set the side glass body to the two sides of the cut 6 by 7 bottom 7PB, one of the right angles is high and the exact side is the same (the real depth is not, put The protrusion -15-(12) 1304137 of 6 places the protruding portion P of the short glass body 6 in the placing portion 7P. Fig. 8(b) shows a sectional view in which the cut surface 6A of the short glass body 6 is placed as the upper surface. In the protruding portion P of the short glass body 6, the reference surface B is brought into contact with the inclined surface 7PB of the placing portion 7P, and the honing surface 5D is placed against the vertical surface 7PA. The inclined surface 7PB of the placing portion 7P and the mold 7 The angle of the bottom surface 7B is ensured to be an angle of 45° with high precision, and the angle between the reference surface B of the short glass body 6 and the honing surface 5D is also 45°. Thus, the protruding portion P of the short glass body 6 is tightly fitted. On the other hand, the interval between the cut surfaces 6 A and 6 B of the short glass body 6 is formed to be slightly longer than the length PL of one side of the 稜鏡1 ,, so that the cut surface 6A becomes a side wall. The upper portion 7U of the portion 7S is slightly raised. Therefore, the cut surface 6A of the ridge 1 , is raised, and the honing proceeds to wait. The length of one side of the prism 1 is PL. At this time, the target is honed to the ridge line position of the reference plane B, whereby the honing can be performed at a length PL equal to one side of the 稜鏡10. b), it can be obtained that the short glass body 6 is a short strip shape in which the cross section of the large substrate 1 is an isosceles right triangle (the length of both sides of the right angle is PL). 6B honing (2nd short glass honing: step S9). At this point of time, in the short glass body 6, the honing surfaces 5C, 5D and 6C are precisely modified at a higher angle to the film forming surface C. Therefore, the remaining cut surface 6B is honed with the honing surface 6C as a reference surface, and the honing surface 6D is formed as shown in Fig. 7(c). Further, the honing surfaces 5C, 5D, and 6C are all aligned. The film surface C is modified with a high degree of precision, so it is not limited to the honing surface 6C, and the honing surface 6D can be formed by using any one surface, any two surfaces, or on the basis of all the surfaces - 16 - (13) 1304137. As mentioned above, all faces of the honing surfaces 5C, 5D, 6C, 6D, etc. will form one face of the 稜鏡10, and can be repaired at a higher angle. The short glass body 6. In addition, the above-mentioned mold 7 is merely an example, and the main point of the present invention is to honing one part of the film formation surface C, that is, the reference surface B as a reference, so the mold 7 is not limited to the eighth. As shown in the figure, any one can be applied as long as it can be honed by the reference plane B. Then, when honing the cut surface 6B, the honing surfaces 5C, 5D, and 6C are described. The honing is performed on the basis of the honing, but it is also possible to prepare a honing tool which can be honed by the reference plane B, and the honing of the cut surface 6B is performed by the dies. Then, the honing surfaces 6C and 6D are not formed. Since the antireflection film is formed, the antireflection film is formed on both surfaces (step S1 0), and then, in the direction perpendicular to the honing surfaces 5C, 5D, 6C, and 6D, as indicated by a broken line in Fig. 7(c), The cutting is performed at intervals (step S 1 1 ). At this time, the cutting interval is equal to the length PL of the prism 1 来 to perform cutting. Thereby, a dielectric multilayer film 3 having a side length of PL and having an angle of 45° as shown in Fig. 2 can be formed, and a crucible 10 having a higher angular precision can be obtained. As described above, the present invention prepares two kinds of substrates having the same width and thickness and different depth dimensions, that is, a large substrate and a small substrate, respectively forming a dielectric multilayer film on one side, and a large substrate and a small substrate. Accumulate several pieces. In this case, both ends of the large substrate are laminated more prominently in the depth direction than the small substrate, whereby a part of the surface on which the dielectric multilayer film is formed is often exposed as the reference surface. A higher angle of accuracy can be achieved by honing the benchmark. -17- (14) 1304137 In addition, the prism 10 of the above-described embodiment has a cubic shape and is formed to have a surface of the dielectric multilayer film 3 of 45°. Therefore, when the large substrate 1 and the small substrate 2 are joined, The layers are stacked at intervals equal to the substrate thickness LZ1 in the width direction. That is, by shifting LZ 1 in the width direction, the above-mentioned stepped angle can be formed at 45 °. However, if the distance in the width direction is not the interval of LZ1, the angle of the above step can be formed at an angle different from 45°. In step S4, the laminated glass body 4 is cut in a direction parallel to the stepped inclination. However, if the stepped angle is formed at an angle different from 45°, the dielectric formed in the last manufactured prism 10 is formed. The multi-layered film 3 can be formed to have a different angle from 45°. Further, the shape of the crucible 10 may be different from the cube. Further, at this time, although it is an angle different from 45, it is possible to manufacture a dielectric multilayer film 3 which is formed at 稜鏡10 with a high angular accuracy. Further, although the optical pickup device is exemplified in the present invention, the present invention is not limited thereto, and any article may be applied as long as it is a dielectric multilayer film formed at a specific angle in a square shape. For example, as an optical component constituting a liquid crystal projector that performs color separation and color synthesis, a color separation 亦可 can also be applied. The color separation 稜鏡 also uses a square shape, which is distinguished by a reflection/transmission color separation film by the wavelength of the incident light, and is formed at an angle of 45° to the optical path. Thus, the color separation 稜鏡 can also be applied to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS [Fig. 1] shows a flow chart of the process flow of the present invention (Fig. 2). Fig. 18-(15) (15) 1304137 [Fig. 3] Large substrate and small substrate Three-dimensional view [Fig. 4] A perspective view of a laminated glass body [Fig. 5] Front and side views of a laminated glass body [Fig. 6] A perspective view of a multiple glass body [Fig. 7] A perspective view of a short glass body [Fig. 8] Stereoscopic view and enlarged view of the mold [Description of main components] 1 : Large substrate 2 : Small substrate 3 : Dielectric multilayer film 4 : Laminated glass body 5 : Multiple glass body 6 : Short glass body 7 : Die B : Reference plane C : film formation surface N: non-film formation surface