200829522 九、發明說明 【發明所屬之技術領域】 本發明關於玻璃製預製件群、玻璃製預製件群之製造 方法以及光學元件之製造方法。 【先前技術】 關於高精度地製造非球面透鏡等玻璃製光學元件的技 術’已知有精密模壓成形法。該方法也被稱爲模製光學成 形法。在該方法，係使用具有經精密加工後的成形面之模 壓成形模具，將經加熱後的玻璃製預製件予以模壓成形， 以成形出光學元件的整體形狀，同時將成形面精密地轉印 到玻璃上，藉此形成光學功能面（例如，參照專利文獻 1 )。 另外，例如可藉由以下方法來生產用於製造上述光學 元件的玻璃製預製件：使熔融的玻璃流出，分離出期望質 量的熔融玻璃塊，將該玻璃塊在冷卻的過程中成形爲預製 件（例如，參照專利文獻2 )。 專利文獻1 :日本特開平1 0 — 3 1 644 8號公報 專利文獻2 :日本特開2 0 02 — 1 2 1 0 3 2號公報 【發明內容】 近年來，對於像附相機的行動電話那樣內設有攝影裝 置的小型機器的需求增多。組裝到該攝影裝置中的攝影光 學系統’係由超小型的透鏡構成，爲了將.各個透鏡進行精 -4- 200829522 治的疋位、固定，較佳爲各個透鏡具有定位基準面。例 如，可使用設置在透鏡面的外周的平面部，來作爲用於精 密地決定透鏡彼此間的間隔的定位基準面；並且可使用透 鏡側面作爲使透鏡彼此的光軸對齊的定位基準面。在精密 模壓成形方法’藉由將模具的成形面轉印到玻璃上，不僅 能夠精密地形成光學功能面，而且還能夠精密地規定所形 成的各個面的位置關係、角度，因此可以一倂形成光學功 能面和定位基準面。 只要充分發揮精密模壓成形的特質，即可高效率地製 造超小型的光學元件，但是另一方面，如果不對預製件的 體積進行精密的管理，則會產生如下問題。 首先，當預製件的體積比具有上模具、下模具、體模 具的模壓成形模具在閉模狀態下所形成的空間的容積更大 時，會從構成模壓成形模具的各個模具構件之間，例如上 模具與體模具之間或下模具與體模具之間擠出並成爲成形 毛邊，而損壞模具的滑動性，導致生產停止或模壓成形模 具破損。另一方面，當預製件的體積比模壓成形模具在閉 模狀態下所形成的空間的容積更小時，玻璃在上述空間中 塡充量不足，由此會造成光學功能面的表面精度降低，或 者由於玻璃未到達構成玻璃的定位基準面的部分，而導致 無法形成定位基準面。 因此，爲了能夠一倂形成光學功能面和定位基準面， 希望使用體積精度、亦即質量精度高的預製件。 如上所述，作爲高生產率的製造玻璃製預製件的方 -5- 200829522 法，係使熔融的玻璃從噴嘴流出，分離爲期望質量的熔融 玻璃塊後，在該玻璃塊冷卻的過程中成形爲預製件。只要 使用該方法來生產預製件，可從玻璃的熔融開始就以極高 的生產率來量產光學元件。但是，在以往的玻璃製預製件 的生產方法，預製件的體積會存在些微偏差，因此當用於 上述精密模壓成形時，未必能夠滿足體積精度、亦即質量 精度。該問題在生產較輕的預製件時尤其顯著。 • 本發明是鑒於上述情況而完成的，其目的在於提供： 各個預製件間的體積偏差受到了極爲嚴格的控制的精密模 壓成形用玻璃製預製件群、以高生產率由熔融玻璃來製造 該預製件群的方法、以及由上述預製件群或者由上述方法 所製得的預製件群中的預製件來製造光學元件的方法。 爲了提高預製件的質量精度，本申請的發明人深入探 討的結果獲得了如下認知。 (a )從噴嘴的流出口滴下熔融玻璃而得到之作爲預 ® 製件母材的熔融玻璃滴的質量，通常依作用於在噴嘴流出 口垂下的玻璃上的向下加速度、噴嘴下端部分的外徑、熔 融玻璃的表面張力等決定，如果要減小目標之質量公差對 於預製件質量的比例，僅藉由將上述複數個條件維持一定 並無法抑制質量的偏差。 (b)考慮導致上述質量偏差的原因在於：當熔融玻 璃滴滴下時，熔融玻璃會沾濡在噴嘴的流出口上，熔融玻 璃的滴下量會由於沾濡量的多少而產生些微變化。 (c )詳細觀察噴嘴可知，其前端有些微的振動，該 -6- 200829522 些微的振動會導致熔融玻璃的滴下量之變動。 (d )另外，噴嘴外周面對於玻璃的沾濡性，會依噴 嘴流出口氣氛的溫度變化 '濕度變化而產生些微變化，該 些微變化會使熔融玻璃的滴下量發生變動。 ' 根據上述認知，本申請的發明人進一步探討的結果發 * 現：從採取防振措施及/或控制氣氛的溫度和濕度的流出 口依序滴下以一定流量流出的熔融玻璃來進行成形，可製 φ 得各個預製件間的體積偏差受到了極爲嚴格的控制的玻璃 製預製件群，如此到達本發明之完成。 即，本發明提供： (1 ) 一種玻璃製預製件群，係由供精密模壓成形的 複數個玻璃製預製件所構成之玻璃製預製件群，其特徵在 於： 玻璃製預製件的質量公差相對於玻璃製預製件的平均 質量MAV的比例爲±0.5xMAV〔 ％〕以內。 • ( 2 )如（1 )所述的玻璃製預製件群，係由整個表面 是使呈熔融狀態的玻璃固化而形成的球狀玻璃製預製件所 構成。 ' (3 ) —種玻璃製預製件群之製造方法，係由供精密 ' 模壓成形的複數個玻璃製預製件所構成之玻璃製預製件群 之製造方法，其特徵在於： 從採取防振措施及/或控制氣氛的溫度和濕度的流出 口依序滴下以一定流量流出的熔融玻璃來進行成形。 (4 )如（3 )所述的玻璃製預製件群之製造方法’其 -7- 200829522 中，前述熔融玻璃滴下後的成形，係在對形成的熔融玻璃 滴施加風壓而使其浮動的狀態下進行。 (5 ) —種光學元件之製造方法，其特徵在於··將 (1 ) 、（ 2 )所述的玻璃製預製件群或藉由（3 ) 、（ 4 ) ~ 所述的方法製得的玻璃製預製件群中之玻璃製預製件進行 # 加熱、精密模壓成形。 (6 )如（5 )所述的光學元件之製造方法，其中， • 精密模壓成形，係藉由將具有上模具、下模具、體模 具的模壓成形模具的各個成形面轉印於玻璃上來進行； 使轉印上模具的成形面而形成的面與轉印體模具的成 形面而形成的面所構成的稜部及/或轉印下模具的成形面 而形成的面與轉印體模具的成形面而形成的面所構成的稜 部成爲自由表面，如此來進行精密模壓成形。 依據本發明可提供：各個預製件間的體積偏差受到了 極爲嚴格的控制的精密模壓成形用玻璃製預製件群、以高 ® 生產率由熔融玻璃來製造該預製件群的方法、以及由上述 預製件群或者由上述方法製得的預製件群中的預製件來製 造光學元件的方法。 【實施方式】 (玻璃製預製件群） 首先，對本發明的玻璃製預製件群進行說明° 本發明的玻璃製預製件群，係由供精密模壓$开彡的複 數個玻璃製預製件所構成之玻璃製預製件群’其特徵在 -8- 200829522 於：玻璃製預製件的質量公差相對於玻璃製預製件的平均 質量MAV的比例爲土0·5χΜΑν〔 ％〕以內。 在本發明中，玻璃製預製件群是指：由相同種類的玻 璃形成’形狀和質量都一致，供精密模壓成形的複數個玻 璃製預製件的集合。另外，在本發明中，玻璃製預製件群 不必僅由在同一裝置中同日一起製造的預製件批次構成， 也可以由複數個預製件批次構成。例如，對於由1 000個 預製件構成的預製件群，可以考慮將由1 00個預製件構成 的批次集合1 0個而構成，也可以考慮將由1 0個預製件構 成的批次集合1 00個而構成。 構成預製件群的預製件的個數較佳爲爲1 000個以 上，更加爲2000個以上，特佳爲5000個以上。可以根據 光學元件的必要個數來決定個數的上限。 MAV意味著構成預製件群的玻璃製預製件的相加平均 値，例如，當玻璃製預製件爲用於行動電話的攝影裝置等 的超小型透鏡用預製件時，Mav爲lmg〜200mg，較佳爲 5〜200mg，特佳爲8〜160mg的程度。 關於本發明的玻璃製預製件群’玻璃製預製件的質量 公差相對於MAV的比例爲±〇·5χΜΑν〔 ％〕以內。 玻璃製預製件的質量公差相對於玻璃製預製件的平均 質量MAV的比例較佳爲±〇·4χΜΑν〔 ％〕以內，特佳爲 ±0.38xMav〔 ％〕以內。 當構成預製件群的預製件的個數爲500個以上時，可 藉由從預製件群中任意抽出的500個預製件來驗證預製件 200829522 的平均質量MAV、以及預製件的質量公差相對於Mav的比 例。 如上所述，對於行動電話等攜帶型設備中內設的小型 光學元件等，爲了能夠進行準確的對準（alignment )和裝 配，較佳爲藉由對預製件進行精密模壓成形來一倂形成光 學功能面和定位基準面，又供上述精密模壓成形的預製件 群中的預製件，係要求質量輕且質量公差小。當預製件的 平均質量MAV大時，比較容易將預製件的質量公差相對於 M a v的比例（質量公差/平均質量M a v )抑制得較小，但是 當預製件的平均質量M a v小時，微小的質量變動就會造成 預製件的質量公差相對於MAV的比例（質量公差/平均質 量MAV )變大，因此以往難以提供由超輕且具有高質量精 度的預製件構成的預製件群。與此相對，在本發明的玻璃 製預製件群中，玻璃製預製件的質量公差相對於玻璃製預 製件的平均質量MAV的比例爲±〇·5χΜΑν〔 ％〕以內，因此 即使在超輕的情況下也可以提供由具有高質量精度的預製 件構成的預製件群。 本發明的玻璃製預製件群較佳爲，由整個表面是使呈 熔融狀態的玻璃固化而形成的球狀玻璃製預製件所構成。 藉由使預製件的整個表面爲呈熔融狀態的玻璃經固化 而形成的面，可以使整個表面爲自由表面，從而可以消除 表面的潛傷。結果，可以使製得的各個預製件的耐候性高 於硏磨製預製件。当耐候性不夠高時，在預製件表面上會 產生稱爲燒痕的變質層，如果除去該變質層，則預製件的 -10· 200829522 質量會些微減少，因而會導致質量精度降低。依據本實施 方式，由於使熔融狀態的玻璃固化來形成預製件的整個表 面，因此可以消除表面的潛傷，從而可以消除上述不良情 況。 另外，當使預製件的形狀爲球形時，只要使用的玻璃 爲相同種類，則隨著預製件質量的增減其直徑也會增減， 各個預製件的質量和直徑會——對應。因此，如果對預製 件的直徑的偏差進行管理，則可以對預製件的質量精度進 行管理。另外，當對預製件進行精密模壓成形來製得小型 的光學元件時，若使用球狀的預製件，只要下模具成形面 呈凹形，即可將預製件穩定地配置在成形面的中心。 藉由以下說明的本發明的玻璃製預製件群之製造方 法’可適當地製造出本發明的玻璃製預製件群。 (玻璃製預製件群之製造方法） 以下，說明本發明的玻璃製預製件群之製造方法。 本發明的玻璃製預製件群之製造方法，係由供精密模 壓成形的複數個玻璃製預製件構成的玻璃製預製件群之製 造方法，其特徵在於： 從採取防振措施及/或控制氣氛的溫度和濕度的流出 口’依序滴下以一定流量流出的熔融玻璃來進行成形。 以下，根據附圖來說明本發明的玻璃製預製件群之製 造方法的較佳爲實施方式。 如第1圖所示，爲了生產預製件群，將玻璃原料經加 -11、 200829522 熱、熔融、澄清、均質化而得的熔融玻璃，導向設置在管 1下端的噴嘴2。熔融玻璃從設置在噴嘴2的下端的流出 口流出，控制管1和噴嘴2的溫度以使單位時間的玻璃流 出量一定。 從流出口流出的熔融玻璃，由於表面張力而在噴嘴2 的下端垂下。當作用在垂下的玻璃上的向下力比使熔融玻 璃停留在噴嘴2下端的力更強時，熔融玻璃從噴嘴2的下 端落下。在此，由於單位時間的玻璃流出量一定，因此熔 融玻璃的落下以一定的周期發生。落下的熔融玻璃滴的總 質量，係用質量表示的單位時間的玻璃流出量乘以上述周 期。 這樣，熔融玻璃滴的質量，係取決於熔融玻璃停留在 噴嘴2下端的力和作用在垂下的玻璃上的向下力的平衡， 但是如上所述，當仔細觀察噴嘴時，其前端的流出口部分 會些微振動，該些微振動會使熔融玻璃的滴下量發生變 化。因此，藉由對噴嘴2採取防振措施來進行滴下，可以 減小預製件間的質量公差。 具體地說，如第2圖所示，將經由管1與噴嘴2連接 的玻璃熔融裝置1 〇 (包括收容熔融玻璃的容器）裝載在防 振台1 1上，從上述容器垂下管1和噴嘴2。如此一來，可 以防止來自建築物的振動經由玻璃熔融裝置1 〇和管1傳 至噴嘴2，從而可以抑制噴嘴2的振動。或者，也可以在 支承玻璃熔融裝置的構造體與建築物之間設置防振機構， 藉由該防振機構來阻斷振動的傳播。 •12- 200829522 上述玻璃熔融裝置1 0可具有：加熱容器內的熔融玻 璃的手段、對容器進行保溫的手段、以及用於使容器內的 熔融玻璃均質化的攪拌手段等；管1例如可具有通電加熱 用的電極、以及用於對管進行保溫的保溫手段等。 | 在本發明的方法，在採取上述防振措施的同時、或者 •代替上述防振措施，係控制流出口氣氛的溫度和濕度，依 序滴下熔融玻璃。 Φ 如上所述，對於玻璃的噴嘴外周面的沾濡性會依噴嘴 流出口氣氛的溫度變化、濕度變化而發生些微變化，由於 該些微變化會使熔融玻璃的滴下量發生變動，因此可藉由 控制噴嘴2的流出口附近的氣氛的溫度和濕度來減小預製 件之間的質量公差。 具體地說，如第2圖所示，在上述玻璃熔融裝置10 的下方設置有恒溫室（booth ) 1 2，在該恒溫室1 2內容納 與玻璃熔融裝置1 〇連接的管1和噴嘴2，在該恒溫室1 2 <1 內設置後述的成形模具1 3。當使用複數個成形模具來連續 生產預製件時，在恒溫室1 2內設置複數個成形模具、裝 載該模具的旋轉台、使旋轉台進行轉位旋轉的驅動裝置’ ' 在上述恒溫室內進行熔融玻璃的滴下和由熔融玻璃滴成形 ' 爲預製件的處理。 藉由未圖示的調溫裝置和濕度調整裝置（以下’稱爲 溫度濕度調整機）將該恒溫室內的溫度、濕度恒定地保持 爲期望的狀態。藉由該操作來控制噴嘴2的流出口週邊的 氣氛的溫度和濕度。上述溫度濕度調整機具有溫度、濕度 -13- 200829522 感測器，反饋由感測器檢測出的結果，將恒溫室1 2內的 氣氛維持爲設定溫度和設定濕度。例如，在冬季乾燥時， 進行加濕以使濕度不會過低，而在梅雨期等濕度大的時 期，進行除濕以使濕度不會過高。對於溫度也進行控制， 以使恒溫室1 2內的氣溫在外部氣溫變動的情況下不會脫 離設定溫度。這樣，將玻璃對噴嘴2外周的沾濡量控制爲 一定，從而可以減小製得的預製件間的質量公差。 在本發明的方法，所稱熔融玻璃的滴下包括：熔融玻 璃塊從噴嘴流出口落下的現象；熔融玻璃流的前端達到承 接熔融玻璃的成形模具的承接面之後，在噴嘴流出□與熔 融玻璃流的前端之間形成的線狀部分斷開後，滴下分離的 現象。 並且’在熔融玻璃流的前端到達上述成形模具的承接 面之後進行熔融玻璃滴的分離的上述方法中，如第1圖所 不’爲了使熔融玻璃滴的質量一定，較佳爲在藉由蓋5覆 蓋在噴嘴2的下端（流出口附近）垂下的熔融玻璃的周圍 的狀態下進行上述滴下。蓋5較佳爲爲中空圓筒狀，如第 1圖所示，以不會遮擋熔融玻璃滴的落下路徑的方式設 置。並且，爲了減弱在噴嘴下端產生的對流所導致的上升 氣流’較佳爲封閉蓋5的上部。藉由該構造，能使熔融玻 璃斷開的位置穩定，從而能夠減小玻璃滴的質量偏差。 決疋上述線狀部分的長短的主要因素是玻璃中的g i 〇 2 的含量，當Si〇2的含量增多（例如，超過2〇質量時 線狀邰分變長’當 S i Ο 2的含量變少（例如，2 0暫量％以 -14 - 200829522 下）時線狀部分變短。就Si02的含量多、形成長的線狀 部分的玻璃而言，受到熔融玻璃流的前端達到成形模具的 承接面時的衝擊，線狀部分容易斷開，因此熔融玻璃的滴 下效率提高。 因此，較佳爲使承接落下的熔融玻璃的成形模具的承 接面與噴嘴前端的距離形成一定，並以固定周期來進行熔 融玻璃的滴下。藉由該構成，可在每次滴下時，使線狀部 分的長度、熔融玻璃流的前端到達成形模具的承接面時的 衝擊發生的時點（timing )穩定化，從而可以減小玻璃滴 的質量偏差。 蓋5覆蓋噴嘴2的下端（流出口）週邊即可，不必覆 蓋熔融玻璃滴的整個滴下路徑，蓋5的長度較佳爲能夠覆 蓋相當於從噴嘴2的下端（流出口）到成形模具的承接面 的距離的1 /5〜4/5的部分，較佳爲能夠覆蓋相當於從噴嘴 2的下端（流出口）到成形模具的承接面的距離的3 /1 0〜 7 /1 〇的部分。 當蓋5爲中空圓筒狀時，如果其口徑過大，會導致操 作性降低，難以使蓋5內的氣氛穩定化，如果過小，流出 的熔融玻璃會附著在蓋5的表面上，或者有時會與噴嘴2 或管1等接觸。另外，如後所述，當朝在噴嘴2的下端垂 下的熔融玻璃施加風壓來促使滴下時，如果口徑過小，則 在噴嘴周圍難以形成穩定的氣流。應考慮上述各點來適當 地設定蓋5的口徑，以使質量公差減小。 上述蓋5具有使在噴嘴2的下端垂下的熔融玻璃的冷 -15- 200829522 卻速度變慢的作用。即’藉由蓋5對垂下的熔融玻璃進行 保溫’使玻璃的黏度上升的速度變慢，從而可以將線狀部 分的黏度保持在適於分離的範圍內，還可以使玻璃滴的黏 度位於適於玻璃球狀化的範圍內。 另外較佳爲，蓋5由絕緣體構成，並且如第1圖所 不’在室的周0配置问頻線圈6並使局頻電流流過該局頻 線圈6，藉此對噴嘴進行高頻感應加熱。依據該構成，能 夠感應加熱由鉑或鉑合金等形成的噴嘴而不感應加熱蓋 5，並且能夠控制噴嘴2的溫度以不使玻璃失透並維持期 望的流出量。 如第1圖所示，較佳爲在管1的下端和噴嘴2的外周 設置氣體流路形成用蓋3。藉由設置氣體流路形成用蓋 3，可在氣體流路形成用蓋3與管1和噴嘴2之間的空間 中形成氣體流路4。並且，在氣體流路形成用蓋3的下端 設置蓋開口部3 -1，使噴嘴2的前端從該開口部突出來。 較佳爲分別在噴嘴2的中心軸周圍同軸地配置氣體流路形 成用蓋3和氣體流路形成用蓋開口部3 -1。另外，較佳爲 使從氣體流路形成用蓋開口部3 -1排出的氣體在上述中心 軸的周圍均勻地流動。 當作用在垂下的熔融玻璃上的重力大於使熔融玻璃停 留在噴嘴下端的力時，發生熔融玻璃的滴下，藉由該方 法，僅能製得依使熔融玻璃停留在噴嘴下端的力所決定的 質量之玻璃滴，而無法滴下更輕的玻璃滴。相對於此’當 藉由上述方法以一定的流量從氣體流路形成用蓋開口部3 - -16· 200829522 1向下連續地噴出氣體時，由於垂下的熔融玻璃受到氣體 風壓所產生之向下的力，所以能夠相應地得到更輕的玻璃 滴。並且，如果藉由質量流量控制器等來控制氣體的流量 以使氣體流量一定的話，能夠使玻璃滴的質量穩定化。 上述熔融玻璃滴下後的成形，較佳爲在朝產生的熔融 玻璃滴施加風壓而使其浮動的狀態下進行。 在噴嘴的下方搬入具有第3圖所示的凹部截面的成形 模具1 3，藉由上述凹部來承接以一定周期從噴嘴滴下的玻 璃滴1 4，將玻璃滴1 4以滾入或滑入的方式導入到凹部 內’藉由從設置在凹部底部的氣體噴出口向上噴出的氣體 使玻璃滴1 4在凹部內上下移動並形成爲球狀，藉此製得 預製件。較佳爲藉由下述方法來進行預製件之量產：準備 複數個成形模具1 3，依序將成形模具搬入噴嘴下方來承接 玻璃滴1 4，將承接到玻璃滴1 4的成形模具1 3從噴嘴下方 搬出’將空的成形模具1 3向噴嘴下方搬入。邊移動成形 模具1 3邊在凹部內將玻璃滴1 4成形爲預製件，在冷卻至 預製件不會變形的溫度範圍之後，從成形模具1 3取出預 製件，作爲空的成形模具而再次搬入噴嘴下方。可藉由對 複數個成形模具的每一個依序進行該步驟來量產預製件， 得到預製件群。 如上所述，根據本發明的方法，能夠抑制會導致預製 件的質量變動的噴嘴流出口的振動和玻璃沾濡量的變動， 從而可.生產出預製件間的質量公差小的預製件群。 -17- 200829522 (光學元件之製造方法） 下面，針對本發明的光學元件之製造方法進行說明。 本發明的光學元件之製造方法的特徵在於：對本發明 的玻璃製預製件群或藉由本發明的玻璃製預製件群之製造 方法製得的玻璃製預製件群中的預製件進行加熱、精密模 壓成形。 精密模壓成形是使用包括上模具、下模具、體模具的 模壓成形模具，加熱預製件，進行模壓成形，將模壓成形 模具的成形面的形狀正確地轉印形成在玻璃上的方法。上 模具、下模具、體模具等各個模具之製造方法及其材質， 在上模具、下模具的成形面上形成的脫模用膜及其形成方 法，進行精密模壓成形的氣氛的種類等可以使用公知技 術。 關於精密模壓成形法的一例，如第4圖所示，把球狀： 預製件1 9配置在凹面形狀的下模具1 6 (插入到體模具1 5 內）的成形面中心，以使成形面與下模具1 6的成形面相 對向的方式將上模具1 7插入到體模具1 5內。在該狀態下 一起加熱預製件1 9和模壓成形模具（體模具1 5、下模具 1 6、上模具1 7 )，在構成預製件1 9的玻璃的溫度，例如 上升到顯示〗〇6dP a· s的黏度的溫度時，降下推桿18，用 上模具1 7和下模具1 6對預製件1 9進行加壓。被加壓的 預製件19，在由上模具17、下模具1 6、體模具1 5包圍的 空間（稱爲模穴）內擴展開。如上所述，將玻璃製預製件 1 9施以模壓，將玻璃塡充到模壓成形模具處於閉模狀態下 -18- 200829522 所形成的密閉空間內。 預先精密地形成閉模狀態下的上模具〗7、下模具 1 6、體模具1 5的各個成形面的相對位置、面法線的夾 角。只要使用該模壓成形模具來進行上述成形，即能以高 精度的相互位置關係、角度來形成光學功能面和定位基準 面。 以透鏡的成形爲例，將上模具成形面的中央部作爲轉 印成形透鏡的光學功能面（透鏡面）的部分，將上模具成 形面的週邊部作爲轉印成形突緣平坦部的部分，使其成爲 環帶狀。對於下模具成形面，也同樣將成形面中央部作爲 轉印成形透鏡面的部分，將成形面週邊部作爲轉印成形突 緣平坦部的部分，使其成爲環帶狀。在模壓成形結束之 前，正確地維持上下模具的方向的相對、以及上下模具的 中心軸的一致。 藉由將玻璃塡充到模壓成形模具處於閉模的狀態下所 形成的密閉空間內，將體模具貫穿孔的內面轉印到玻璃 上。精密地形成體模具貫穿孔的中心軸和上述貫穿孔內面 的角度，在模壓成形結束之前，精密地維持上述貫穿孔的 中心軸與上下模具中心軸的一致，藉此例如第5圖所示， 能夠精密地形成具有兩個透鏡面20、2 1、兩個突緣平坦部 22、23、以及轉印體模具的內面而形成的側端（突緣平坦 部22、23的側面）24的透鏡，並且可正確地形成上述各 部的相對位置和各面的夾角。 藉由本發明的方法製得的光學元件，除了光學功能面 -19· 200829522 之外還具有定位基準面。例如，透鏡的定位基準面，是用 於決定透鏡彼此的間隔的基準面和用於正確地使透鏡的光 軸彼此一致的基準面，藉由使這些基準面與保持具抵接， 能夠準確地對準各個透鏡。就上述例子來說，將突緣平坦 部22、2 3中的一方作爲第一定位基準面，使該基準面與 保持具抵接，藉此可以準確地對透鏡之間的距離進行定 位。較佳爲對另一方的突緣平坦面施加用於維持上述抵接 狀態的壓力，維持將透鏡固定在保持具上的狀態。另外， 以側端24作爲第二定位基準面，而作爲使透鏡的光軸正 確地保持一致的基準面來使用。 在光學元件，較佳爲藉由精密模壓成形來形成至少兩 面以上、具體地說是兩面或三面的定位基準面。較佳爲使 上述兩面或三面的定位基準面相互不平行。當這樣使用相 互不平行的兩個基準面來定位光學元件時，能夠高精度地 決定光學系統中的光學元件的定位和方向。如透鏡般具有 旋轉對稱性的光學元件時，具有兩個定位基準面即可。當 爲稜鏡般不具有旋轉對稱性的光學元件時，藉由形成三個 定位基準面，能夠高精度地決定在光學系統的位置和在該 位置的方向。 爲了提高玻璃在上下模具成形面上的脫模性而設置脫 模用膜，由於難以在體模具的內面（插入上模具、下模具 之貫穿孔的內面）設置厚度均勻的脫模用膜，因此在轉印 到側端的成形面上通常不設置脫模用膜。因此，爲了在模 壓成形時防止玻璃熔接在體模具的內面上，較佳爲在玻璃 -20- 200829522 不會破損的範圍內使側端24的面積儘可能縮小，使玻璃 與體模具的接觸面積爲必要的最小限度。然而，在對側端 厚度（突緣平坦部22、23之間的距離）薄的透鏡施以精 密模壓成形時，玻璃是從成爲透鏡面的部分開始塡充，並 逐漸向體模具方向擴展開，此時，由於轉印成形兩個突緣 平坦部22 ' 23的上模具成形面和下模具成形面之間的空 間的容積小，只要構成預製件的玻璃的量些微過剩時，玻 璃就會從上述空間擠出，從而產生成形毛邊；而只要上述 玻璃的量些微不足時，即便進行模壓玻璃也不會到達體模 具’從而無法形成應成爲定位基準面的側端。即，在用於 成形上述光學元件的預製件的全部質量中，僅允許存在極 小量的過多或者過少量，但是在本發明的方法中，由於相 對於目標的透鏡質量可正確決定所製得的預製件的質量， 因此即使側端厚度薄的情形，也能轉印體模具的內面而成 形出側端（具備定位基準面的功能），並且不會產生成形 毛邊而導致必須停止光學元件的量產步驟停止的情況。 .在本發明的方法較佳爲，使轉印上模具的成形面而形 成的面與轉印體模具的成形面而形成的面所構成的稜部及 /或轉印下模具的成形面而形成的面與轉印體模具的成形 面而形成的面所構成的棱部爲自由表面，以這種方式將玻 璃製預製件施以精密模壓成形。 只要如上述般精密地形成側端和突緣平坦部，就不會 影響定位功能，例如，在第5圖所示的透鏡中，當稜部25 或稜部26銳利時，在嵌入保持具時會出現稜部破損、或 -21 - 200829522 者稜部刮削保持具的情況，而導致產生塵埃。由於塵埃附 著在攝影元件的受光面上會造成畫質大幅降低，爲了防止 出現這樣的麻煩，較佳爲成形爲具有自由表面所構成的稜 部之光學元件。另外，藉由使上述稜部爲自由表面，即使 在預製件之間產生若千質量公差的情形，稜部可發揮體積 •調整的作用’從而可避免出現產生成形毛邊或玻璃的塡充 不充分的問題。 • 可以根據需要，在如此般製造的光學元件上形成反射 防止膜等光學多層膜。 (實施例） 以下，藉由實施例對本發明做更詳細的說明，但是本 發明不限於這些實施例。 實施例1 (玻璃製預製件群的製造例） • 首先，爲了得到具有期望的光學特性、玻璃轉化溫度 的光學玻璃，稱量、調合玻璃原料並對其進行充分的攪 拌，然後將其導入到熔融容器內並進行加熱、熔融、澄 清、攪拌，由此得到均勻的熔融玻璃。該玻璃含有 ’ B2〇3、Si02、BaO、Li20，折射率 nd 爲 1.58 3 13，阿貝數 d 爲 59.46。 使用第1圖所示的裝置，由上述熔融玻璃來生產3 000 個目標質量爲1 0 0 m g的玻璃製預製件。 在此，將包括熔融容器的玻璃熔融裝置裝載在防振台 -22- 200829522 上。在防振台上設置讓管1 (用於使玻璃流下）通過的開 口部，通過該開口部使管1從上述容器垂下，在管1的下 端安裝有使熔融玻璃流出的噴嘴2。利用上述構造，藉由 防振台可阻斷來自設置上述設備的建築物的振動，而使振 • 動不致傳至噴嘴2。 •在噴嘴2的下方配置有成形模具，管1的下端部分、 噴嘴2、以及成形模具配置在恒溫室內，用空調將該恒溫 Φ 室的內部氣氛控制在溫度爲25°C、相對濕度爲10〜95%的 範圍內。依據上述構造，可控制設置在噴嘴2的下端的熔 融玻璃流出口附近的溫度和濕度，而將噴嘴外周面的熔融 玻璃的沾濡性控制爲一定。 經由與熔融容器底部連接的管1，從安裝在管1下端 的噴嘴2以一定流量流出熔融玻璃。控制噴嘴2、管1、 以及熔融容器各個的溫度，以使玻璃成爲不會失透且成爲 可獲得期望流出量的黏度。 • 如第1圖所示，在管1的下端和噴嘴2的外周設置有 氣體流路形成用蓋3，在管1和噴嘴2與氣體流路形成用 蓋3之間的空間中形成有氣體流路4。並且，在氣體流路 形成用蓋3的下端設置有開口部3 -1 ’噴嘴2的前端從該 開口部突出。噴嘴2、氣體流路形成用蓋3、氣體流路形 成用蓋開口部3 -1較佳爲，分別在噴嘴2的中心軸的周圍 對稱地配置成同軸狀。另外’從氣體流路形成用蓋開口部 3 -1排出的氣體較佳爲，在上述中心軸的周圍均勻地流 動0 -23-200829522 IX. Description of the Invention [Technical Field] The present invention relates to a glass preform group, a glass preform group manufacturing method, and an optical element manufacturing method. [Prior Art] A technique of producing a glass optical element such as an aspherical lens with high precision is known as a precision press molding method. This method is also referred to as a molded optical forming method. In this method, a heated glass preform is molded by using a press-molding mold having a precision-molded forming surface to form an overall shape of the optical element while precisely transferring the forming surface to An optical functional surface is formed on the glass (for example, refer to Patent Document 1). Further, for example, a glass preform for producing the above optical element can be produced by discharging a molten glass, separating a molten glass block of a desired quality, and forming the glass block into a preform during cooling. (For example, refer to Patent Document 2). Patent Document 1: Japanese Laid-Open Patent Publication No. Hei No. Hei. No. Hei. No. 2 0 02 - 1 2 1 0 3 2 [Invention] In recent years, for a mobile phone like a camera There is an increasing demand for small machines with imaging devices. The photographic optical system incorporated in the photographic apparatus is composed of an ultra-small lens. In order to perform the clamping and fixing of each lens, it is preferable that each lens has a positioning reference surface. For example, a flat portion provided on the outer circumference of the lens surface may be used as a positioning reference surface for precisely determining the interval between the lenses; and a lens side surface may be used as a positioning reference surface for aligning the optical axes of the lenses with each other. In the precision press molding method, by transferring the molding surface of the mold onto the glass, not only can the optical functional surface be precisely formed, but also the positional relationship and angle of each surface to be formed can be precisely defined, so that it can be formed at a glance Optical functional surface and positioning datum. As long as the characteristics of precision press molding are sufficiently exerted, ultra-small optical elements can be manufactured efficiently, but on the other hand, if the volume of the preform is not precisely managed, the following problems occur. First, when the volume of the preform is larger than the volume of the space formed by the press molding die having the upper mold, the lower mold, and the body mold in the mold closing state, between the respective mold members constituting the press molding mold, for example, Extrusion between the upper mold and the body mold or between the lower mold and the body mold and forming a burr, thereby damaging the slidability of the mold, resulting in production stoppage or breakage of the mold. On the other hand, when the volume of the preform is smaller than the volume of the space formed by the press molding die in the mold closing state, the amount of charge of the glass in the above space is insufficient, thereby causing a decrease in the surface precision of the optical functional surface, or Since the glass does not reach the portion constituting the positioning reference surface of the glass, the positioning reference surface cannot be formed. Therefore, in order to form the optical functional surface and the positioning reference surface together, it is desirable to use a preform having a volumetric accuracy, that is, a high quality precision. As described above, as a high-productivity method for producing a glass preform, the method of forming a glass preform is carried out by discharging molten glass from a nozzle, separating it into a molten glass block of a desired mass, and forming it into a process of cooling the glass block. Prefabricated parts. As long as the method is used to produce a preform, the optical component can be mass-produced with an extremely high productivity from the melting of the glass. However, in the conventional method for producing a glass preform, there is a slight deviation in the volume of the preform. Therefore, when used for the above-mentioned precision press molding, the volume accuracy, that is, the mass accuracy may not be satisfied. This problem is particularly pronounced when producing lighter preforms. The present invention has been made in view of the above circumstances, and an object thereof is to provide a prefabricated glass preform assembly for precise press molding in which the volume deviation between the preforms is extremely tightly controlled, and the prefabrication is performed from molten glass with high productivity. A method of manufacturing a component, and a method of manufacturing an optical component from the preform group or the preform in the preform group produced by the above method. In order to improve the quality accuracy of the preform, the inventors of the present application have intensively obtained the following findings. (a) The mass of the molten glass droplet which is obtained as a pre-product base material by dropping the molten glass from the discharge port of the nozzle, usually depending on the downward acceleration acting on the glass hanging down the nozzle outlet, and the lower end portion of the nozzle The diameter, the surface tension of the molten glass, and the like are determined. If the ratio of the mass tolerance of the target to the mass of the preform is to be reduced, the deviation of the mass cannot be suppressed only by maintaining the above plurality of conditions. (b) The reason for the above-mentioned mass deviation is that the molten glass will adhere to the outlet of the nozzle when the molten glass is dropped, and the amount of the molten glass will slightly change due to the amount of the stain. (c) A detailed observation of the nozzle shows that there is a slight vibration at the front end, and the slight vibration of the -6-200829522 causes a change in the amount of dripping of the molten glass. (d) In addition, the adhesion of the outer peripheral surface of the nozzle to the glass varies slightly depending on the temperature change of the nozzle outlet atmosphere, and the slight change causes the amount of dripping of the molten glass to vary. Based on the above findings, the inventors of the present application further explored the results of forming a molten glass that flows out at a constant flow rate from a flow outlet that takes anti-vibration measures and/or controls the temperature and humidity of the atmosphere. The φ is obtained from the group of glass preforms whose volume deviation between the preforms is extremely tightly controlled, thus reaching the completion of the present invention. That is, the present invention provides: (1) A group of glass preforms, which is a group of glass preforms composed of a plurality of glass preforms for precision press molding, characterized in that: the quality tolerance of the glass preforms is relatively The ratio of the average mass MAV of the glass preform is within ±0.5 x MAV [%]. (2) The prefabricated glass preform according to (1), wherein the entire surface is a spherical glass preform formed by solidifying a molten glass. ' (3) A manufacturing method of a glass preform group, which is a method for manufacturing a glass preform group composed of a plurality of precision glass molded preforms, characterized by: taking anti-vibration measures And/or a flow outlet that controls the temperature and humidity of the atmosphere, and sequentially draws molten glass that flows out at a constant flow rate to form. (4) The method for producing a glass preform group according to (3), wherein the molding of the molten glass after dropping is performed by applying a wind pressure to the formed molten glass droplet to float it. In the state. (5) A method of producing an optical element, comprising: the glass preform group according to (1) or (2), or the method described in (3), (4)~ The glass prefabricated parts in the glass prefabricated parts are subjected to heating and precision molding. (6) The method of producing an optical element according to the above aspect, wherein the precision molding is performed by transferring each molding surface of a press molding die having an upper mold, a lower mold, and a mold to a glass. a rib formed by a surface formed by transferring a surface formed by molding the upper mold and a surface formed by a molding surface of the transfer mold, and/or a surface formed by transferring a molding surface of the lower mold and a transfer mold The ridge portion formed by the surface formed by the molding surface is a free surface, and thus precision press molding is performed. According to the present invention, it is possible to provide a glass preform preform for precision press molding in which the volume deviation between the respective preforms is extremely tightly controlled, a method of manufacturing the preform group from molten glass with high productivity, and prefabrication by the above-described prefabrication A method of manufacturing an optical component by a group of parts or a preform in a preform group produced by the above method. [Embodiment] (Glass Preforms) First, the glass preforms of the present invention will be described. The glass preforms of the present invention are composed of a plurality of prefabricated glass preforms that are precision molded and opened. The glass prefabricated group is characterized by the ratio of the mass tolerance of the glass preform to the average mass MAV of the glass preform being less than 0. 5 χΜΑ ν [%]. In the present invention, the glass preform group means a collection of a plurality of glass preforms which are formed of the same kind of glass and have the same shape and quality for precision press molding. Further, in the present invention, the glass preform group does not have to be composed only of the preform batch which is manufactured together in the same apparatus on the same day, but may be composed of a plurality of preform batches. For example, for a group of prefabricated parts consisting of 1 000 prefabricated parts, it is conceivable to combine 10 batches consisting of 100 prefabricated parts, and it is also conceivable to collect a batch consisting of 10 prefabricated parts. And constitute. The number of the preforms constituting the preform group is preferably more than 1,000, more preferably 2,000 or more, and particularly preferably 5,000 or more. The upper limit of the number can be determined according to the necessary number of optical elements. MAV means the sum average of the glass preforms constituting the preform group. For example, when the glass preform is a preform for ultra-small lenses such as a photographing device for a mobile phone, Mav is 1 mg to 200 mg. It is preferably 5 to 200 mg, and particularly preferably 8 to 160 mg. Regarding the glass preform of the present invention, the ratio of the mass tolerance of the glass preform to the MAV is within ± 〇 · 5 χΜΑ ν [%]. The ratio of the mass tolerance of the glass preform to the average mass MAV of the glass preform is preferably within ±〇·4χΜΑν [%], particularly preferably within ±0.38xMav [%]. When the number of preforms constituting the preform group is 500 or more, the average mass MAV of the preform 200829522 and the mass tolerance of the preform can be verified by the 500 preforms arbitrarily extracted from the preform group. The proportion of Mav. As described above, in order to enable accurate alignment and assembly for a small optical component or the like provided in a portable device such as a mobile phone, it is preferable to form the optical by precision molding of the preform. The functional surface and the positioning reference surface are also provided for the preforms in the precision molded preform group described above, which are required to have a light weight and a small quality tolerance. When the average mass MAV of the preform is large, it is relatively easy to suppress the ratio of the mass tolerance of the preform to the mass (mass tolerance/average mass M av ) to be small, but when the average mass of the preform is small, The quality variation causes the ratio of the mass tolerance of the preform to the MAV (mass tolerance/average mass MAV) to become large, and thus it has been difficult in the past to provide a preform group composed of a preform that is ultra-light and has high-quality precision. On the other hand, in the glass preform group of the present invention, the ratio of the mass tolerance of the glass preform to the average mass MAV of the glass preform is within ±〇·5χΜΑν [%], so even in an ultra-light It is also possible in the case to provide a preform group consisting of preforms with high quality precision. The glass preform according to the present invention is preferably composed of a spherical glass preform formed by solidifying a glass in a molten state over the entire surface. By making the entire surface of the preform a surface formed by solidifying the molten glass, the entire surface can be made a free surface, thereby eliminating surface damage. As a result, it is possible to make the weather resistance of each of the prepared preforms higher than that of the honing preform. When the weather resistance is not high enough, a metamorphic layer called burn marks is formed on the surface of the preform. If the altered layer is removed, the quality of the preform is slightly reduced, which leads to a decrease in mass accuracy. According to the present embodiment, since the molten glass is solidified to form the entire surface of the preform, the surface damage can be eliminated, and the above-described problem can be eliminated. Further, when the shape of the preform is made spherical, as long as the glass used is of the same kind, the diameter of the preform will increase or decrease as the quality of the preform increases or decrease, and the mass and diameter of each preform will correspond. Therefore, if the deviation of the diameter of the preform is managed, the quality accuracy of the preform can be managed. Further, when the preform is subjected to precision press molding to obtain a small optical element, if a spherical preform is used, the preform can be stably disposed at the center of the forming surface as long as the lower mold forming surface is concave. The glass preform group of the present invention can be suitably produced by the method for producing a glass preform group of the present invention described below. (Manufacturing Method of Glass Preform Group) Hereinafter, a method of manufacturing the glass preform group of the present invention will be described. The method for producing a glass preform group according to the present invention is a method for producing a glass preform group composed of a plurality of glass preforms which are subjected to precision press molding, and is characterized by: taking vibration prevention measures and/or controlling atmosphere The temperature and humidity outlets are sequentially formed by dropping molten glass flowing at a constant flow rate. Hereinafter, preferred embodiments of the method for producing a glass preform group of the present invention will be described with reference to the accompanying drawings. As shown in Fig. 1, in order to produce a preform group, the molten glass obtained by heat-melting, melting, clarifying, and homogenizing the glass raw material by adding -11, 200829522 is guided to the nozzle 2 provided at the lower end of the tube 1. The molten glass flows out from the outflow port provided at the lower end of the nozzle 2, and controls the temperatures of the tubes 1 and 2 to make the amount of glass flow per unit time constant. The molten glass flowing out from the outflow port hangs down at the lower end of the nozzle 2 due to the surface tension. The molten glass falls from the lower end of the nozzle 2 when the downward force acting on the hanging glass is stronger than the force which causes the molten glass to stay at the lower end of the nozzle 2. Here, since the amount of outflow of the glass per unit time is constant, the fall of the molten glass occurs at a certain cycle. The total mass of the dropped molten glass droplets is multiplied by the above-mentioned period by the amount of glass outflow per unit time expressed by mass. Thus, the quality of the molten glass drop depends on the balance of the force of the molten glass staying at the lower end of the nozzle 2 and the downward force acting on the hanging glass, but as described above, when the nozzle is carefully observed, the front end of the outlet Some of them will vibrate slightly, and these microvibrations will change the amount of dripping of the molten glass. Therefore, by performing anti-vibration measures on the nozzle 2 to perform dripping, the quality tolerance between the preforms can be reduced. Specifically, as shown in Fig. 2, a glass-melting device 1 (including a container for accommodating molten glass) connected to the nozzle 2 via the tube 1 is placed on the vibration-proof table 1 1 , and the tube 1 and the nozzle are suspended from the container. 2. In this way, vibration from the building can be prevented from being transmitted to the nozzle 2 via the glass melting device 1 and the tube 1, so that the vibration of the nozzle 2 can be suppressed. Alternatively, an anti-vibration mechanism may be provided between the structure supporting the glass melting device and the building, and the vibration is prevented from being transmitted by the anti-vibration mechanism. • 12-200829522 The glass melting apparatus 10 may have means for heating the molten glass in the container, means for holding the container, and stirring means for homogenizing the molten glass in the container; and the tube 1 may have, for example An electrode for energization heating, a heat retention means for holding the tube, and the like. In the method of the present invention, the above-mentioned vibration-proofing measure is taken, or instead of the above-described vibration-proofing measure, the temperature and humidity of the outflow atmosphere are controlled, and the molten glass is sequentially dropped. Φ As described above, the staining property of the outer peripheral surface of the nozzle of the glass slightly changes depending on the temperature change and the humidity change of the nozzle outlet atmosphere, and the slight variation causes the amount of dripping of the molten glass to vary. The temperature and humidity of the atmosphere near the outflow opening of the nozzle 2 are controlled to reduce the mass tolerance between the preforms. Specifically, as shown in Fig. 2, a thermostatic chamber (1) is provided below the glass melting apparatus 10, and the tube 1 and the nozzle 2 connected to the glass melting apparatus 1 are housed in the constant temperature chamber 12, In the thermostatic chamber 1 2 In the <1, a molding die 13 to be described later is provided. When a plurality of forming dies are used to continuously produce a preform, a plurality of forming dies, a rotating table on which the mold is loaded, and a driving device that rotates the rotating table are rotated in the constant temperature chamber. The dripping of the glass and the formation of the droplets from the molten glass are treated as preforms. The temperature and humidity in the constant temperature chamber are constantly maintained in a desired state by a temperature regulating device and a humidity adjusting device (hereinafter referred to as a temperature and humidity adjusting device) (not shown). By this operation, the temperature and humidity of the atmosphere around the outflow port of the nozzle 2 are controlled. The temperature and humidity adjuster has a temperature and humidity -13 - 200829522 sensor, and feedbacks the result detected by the sensor to maintain the atmosphere in the constant temperature chamber 12 at a set temperature and a set humidity. For example, when it is dry in winter, it is humidified so that the humidity is not too low, and when the humidity is high during the plum rain period, dehumidification is performed so that the humidity is not excessively high. The temperature is also controlled so that the temperature in the constant temperature chamber 12 does not deviate from the set temperature when the outside air temperature fluctuates. Thus, the amount of staining of the glass to the outer circumference of the nozzle 2 is controlled to be constant, so that the quality tolerance between the manufactured preforms can be reduced. In the method of the present invention, the so-called dropping of the molten glass includes a phenomenon in which the molten glass lump falls from the nozzle outflow port; after the front end of the molten glass flow reaches the receiving surface of the forming die for receiving the molten glass, the nozzle flows out □ and the molten glass flow After the linear portion formed between the front ends is broken, the phenomenon of separation is dropped. Further, in the above method of performing the separation of the molten glass droplets after the tip end of the molten glass flow reaches the receiving surface of the molding die, as shown in Fig. 1, in order to make the quality of the molten glass droplet constant, it is preferable to cover 5 The above-described dropping is performed in a state where the periphery of the molten glass hanging down the lower end of the nozzle 2 (near the outflow port) is covered. The cover 5 is preferably in the shape of a hollow cylinder, and as shown in Fig. 1, is provided so as not to block the falling path of the molten glass droplets. Further, the ascending air current caused by the convection generated at the lower end of the nozzle is preferably the upper portion of the closing cover 5. With this configuration, the position at which the molten glass is broken can be stabilized, and the quality deviation of the glass drop can be reduced. The main factor for determining the length of the above-mentioned linear portion is the content of gi 〇 2 in the glass. When the content of Si 〇 2 is increased (for example, when the mass exceeds 2 〇, the linear enthalpy becomes longer) when the content of S i Ο 2 When the amount is small (for example, 20% of the temporary amount is -14 - 200829522), the linear portion becomes shorter. In the case of glass having a large content of SiO 2 and forming a long linear portion, the front end of the molten glass flow reaches the forming mold. In the impact at the time of receiving the surface, the linear portion is easily broken, so that the dropping efficiency of the molten glass is improved. Therefore, it is preferable that the distance between the receiving surface of the molding die for receiving the dropped molten glass and the tip end of the nozzle is constant and fixed. By this configuration, it is possible to stabilize the timing at which the length of the linear portion and the tip end of the molten glass flow reach the receiving surface of the molding die at the time of dropping each time. Therefore, the quality deviation of the glass drop can be reduced. The cover 5 covers the periphery of the lower end (outlet) of the nozzle 2, and does not have to cover the entire dropping path of the molten glass drop, and the length of the cover 5 is preferably capable of A portion corresponding to 1/5 to 4/5 of the distance from the lower end (outflow port) of the nozzle 2 to the receiving surface of the forming die is preferably covered so as to cover the lower end (outflow port) from the nozzle 2 to the forming die. When the cover 5 has a hollow cylindrical shape, the distance of the contact surface is 3/1 0 to 7 /1. If the diameter is too large, the operability is lowered, and it is difficult to stabilize the atmosphere in the cover 5. If it is too small, the molten glass that flows out may adhere to the surface of the cover 5, or may come into contact with the nozzle 2 or the tube 1 or the like. Further, as will be described later, when the wind pressure is applied to the molten glass hanging down the lower end of the nozzle 2 When the drip is promoted, if the caliber is too small, it is difficult to form a stable airflow around the nozzle. The caliber of the cover 5 should be appropriately set in consideration of the above points to reduce the mass tolerance. The cover 5 has a lower end which is suspended at the lower end of the nozzle 2. The cold glass of -15-200829522 has a slower speed, that is, 'insulation of the suspended molten glass by the cover 5' slows the viscosity of the glass, so that the viscosity of the linear portion can be maintained at Suitable for In the range of the glass drop, the viscosity of the glass drop can be made to be in a range suitable for the spheroidization of the glass. Further, it is preferable that the cover 5 is composed of an insulator, and the frequency coil is disposed in the circumference of the chamber as shown in FIG. 6 and a local frequency current is passed through the local frequency coil 6, whereby the nozzle is subjected to high frequency induction heating. According to this configuration, the nozzle formed of platinum or platinum alloy or the like can be inductively heated without inducing the heating cover 5, and can be controlled. The temperature of the nozzle 2 is such that the glass is devitrified and the desired outflow amount is maintained. As shown in Fig. 1, it is preferable to provide the gas flow path forming cover 3 at the lower end of the tube 1 and the outer periphery of the nozzle 2. The flow path forming cover 3 can form the gas flow path 4 in the space between the gas flow path forming cover 3 and the tube 1 and the nozzle 2. Further, the cover opening portion 3 is provided at the lower end of the gas flow path forming cover 3. -1, the front end of the nozzle 2 is protruded from the opening. It is preferable that the gas flow path forming cover 3 and the gas flow path forming cover opening portion 3-1 are disposed coaxially around the central axis of the nozzle 2, respectively. Further, it is preferable that the gas discharged from the gas flow path forming cover opening portion 3-1 uniformly flows around the center axis. When the gravity acting on the suspended molten glass is greater than the force that causes the molten glass to stay at the lower end of the nozzle, the dropping of the molten glass occurs, by which only the force depending on the force at which the molten glass stays at the lower end of the nozzle can be obtained. The glass of quality drops, and it is impossible to drop lighter glass drops. On the other hand, when the gas is continuously discharged downward from the gas flow path forming cover opening portion 3 - -16 · 200829522 1 by a predetermined flow rate, the downward molten glass is subjected to the gas wind pressure. The force is lower, so the lighter glass drops can be obtained accordingly. Further, if the flow rate of the gas is controlled by the mass flow controller or the like so that the gas flow rate is constant, the quality of the glass drop can be stabilized. The molding after the molten glass is dropped is preferably carried out in a state where wind pressure is applied to the molten glass droplets generated and floated. The molding die 13 having the concave portion cross section shown in Fig. 3 is carried under the nozzle, and the glass drip 14 dropped from the nozzle at a predetermined cycle is received by the concave portion, and the glass drop 14 is rolled or slipped. The method is introduced into the concave portion. The preform is produced by moving the glass droplet 14 up and down in the concave portion by a gas ejected upward from the gas ejection port provided at the bottom of the concave portion to form a spherical shape. Preferably, the mass production of the preform is carried out by preparing a plurality of forming dies 13 and sequentially carrying the forming dies under the nozzles to receive the glass drops 14 and to receive the forming dies 1 of the glass drops 14 3 Carrying out from under the nozzle 'The empty forming die 13 is carried under the nozzle. While the molding die 13 is moved, the glass drop 14 is formed into a preform in the concave portion, and after cooling to a temperature range in which the preform is not deformed, the preform is taken out from the molding die 13 and moved again as an empty molding die. Below the nozzle. The preform can be mass-produced by sequentially performing this step for each of a plurality of forming dies to obtain a preform group. As described above, according to the method of the present invention, it is possible to suppress the vibration of the nozzle outflow which causes the quality of the preform to vary, and the variation in the amount of glass smearing, thereby producing a preform group having a small mass tolerance between the preforms. -17- 200829522 (Method of Manufacturing Optical Element) Next, a method of manufacturing the optical element of the present invention will be described. The method for producing an optical element according to the present invention is characterized in that the preform of the glass preform of the present invention or the preform of the glass preform produced by the method for producing a glass preform of the present invention is heated and precision molded. Forming. The precision press molding is a method in which a preform is formed by using a press molding die including an upper die, a lower die, and a die, and the preform is heated, and the shape of the molding surface of the press molding die is accurately transferred onto the glass. The method for producing each of the molds such as the upper mold, the lower mold, and the body mold, and the material thereof, the release mold film formed on the molding surface of the upper mold and the lower mold, and the method for forming the same, and the type of the atmosphere for precision press molding can be used. Known technology. As an example of the precision press molding method, as shown in Fig. 4, the spherical shape: the preform 19 is placed at the center of the molding surface of the concave mold 16 (inserted into the body mold 15) so that the molding surface is formed. The upper mold 17 is inserted into the body mold 15 in such a manner as to face the molding surface of the lower mold 16. In this state, the preform 19 and the press molding die (the body mold 15 , the lower mold 16 , and the upper mold 1 7 ) are heated together, and the temperature of the glass constituting the preform 19 is raised, for example, to the display 〇 6dP a When the temperature of the viscosity of s is lowered, the pusher 18 is lowered, and the preform 19 is pressurized by the upper mold 17 and the lower mold 16. The pressurized preform 19 is expanded in a space (referred to as a cavity) surrounded by the upper mold 17, the lower mold 16, and the body mold 15. As described above, the glass preform 19 is molded, and the glass crucible is filled into the sealed space formed by the molding die at the mold closing state -18-200829522. The relative position of each of the forming faces of the upper die 7 and the lower die 16 and the blank die 15 in the mold closing state and the face normal are formed in advance in a closed state. When the above molding is carried out using the press molding die, the optical functional surface and the positioning reference surface can be formed with high mutual positional relationship and angle. Taking the lens forming as an example, the central portion of the upper mold forming surface is a portion of the optical functional surface (lens surface) of the transfer molded lens, and the peripheral portion of the upper mold forming surface is a portion of the transfer forming flange flat portion. Make it a band shape. In the lower mold forming surface, the central portion of the forming surface is also a portion for transferring the formed lens surface, and the peripheral portion of the forming surface is formed as a portion of the flat portion of the transfer forming flange to have an endless belt shape. Before the end of the press molding, the direction of the upper and lower dies and the alignment of the central axes of the upper and lower dies are correctly maintained. The inner surface of the through-hole of the body mold is transferred onto the glass by filling the glass crucible into a sealed space formed by the mold-molding mold in a state where the mold is closed. The angle between the central axis of the through hole and the inner surface of the through hole is precisely formed, and the central axis of the through hole and the central axis of the upper and lower molds are precisely maintained until the end of the press molding, for example, as shown in FIG. The side end (the side surface of the flange flat portions 22, 23) 24 having the two lens faces 20, 21, the two flange flat portions 22, 23, and the inner surface of the transfer body mold can be precisely formed. The lens, and the relative position of each of the above portions and the angle between the faces can be correctly formed. The optical element produced by the method of the present invention has a positioning reference plane in addition to the optical functional surface -19·200829522. For example, the positioning reference surface of the lens is a reference surface for determining the interval between the lenses and a reference surface for accurately matching the optical axes of the lenses. By bringing these reference surfaces into contact with the holder, it is possible to accurately Align each lens. In the above example, one of the flange flat portions 22 and 23 is used as the first positioning reference surface, and the reference surface is brought into contact with the holder, whereby the distance between the lenses can be accurately positioned. It is preferable to apply a pressure for maintaining the above-mentioned abutting state to the other flat surface of the flange, and to maintain the state in which the lens is fixed to the holder. Further, the side end 24 is used as the second positioning reference surface, and is used as a reference surface for accurately maintaining the optical axis of the lens. In the optical element, it is preferable to form a positioning reference surface of at least two or more, specifically two or three sides by precision press molding. Preferably, the positioning reference faces of the two or three faces are not parallel to each other. When the optical elements are positioned using two reference faces that are not parallel to each other, the positioning and orientation of the optical elements in the optical system can be determined with high precision. When an optical element having a rotational symmetry like a lens has two positioning reference planes. In the case of an optical element having no rotational symmetry like this, by forming three positioning reference planes, the position of the optical system and the direction at the position can be determined with high precision. In order to improve the mold release property of the glass on the upper and lower mold forming surfaces, a film for mold release is provided, and it is difficult to provide a film for mold release having a uniform thickness on the inner surface of the body mold (the inner surface of the through hole of the upper mold and the lower mold). Therefore, a film for mold release is usually not provided on the forming surface transferred to the side end. Therefore, in order to prevent the glass from being welded to the inner surface of the body mold during the press molding, it is preferable to make the area of the side end 24 as small as possible within a range in which the glass -20-200829522 is not broken, so that the glass is in contact with the body mold. The area is the minimum necessary. However, when the lens having a thin side end thickness (distance between the flange flat portions 22 and 23) is subjected to precision press molding, the glass is filled from the portion which becomes the lens surface, and gradually spreads toward the body mold. At this time, since the volume of the space between the upper mold forming surface and the lower mold forming surface of the two flange flat portions 22' 23 is small, as long as the amount of glass constituting the preform is excessively large, the glass is Extrusion from the above space produces a formed burr; and if the amount of the glass is slightly insufficient, the molded glass does not reach the body mold, and the side end to be the positioning reference surface cannot be formed. That is, only a very small amount or too small amount is allowed to be present in the entire mass of the preform for forming the above optical element, but in the method of the present invention, the obtained quality can be correctly determined due to the lens quality with respect to the target. The quality of the preform, so that even if the thickness of the side end is thin, the inner surface of the body mold can be transferred to form the side end (the function of positioning the reference surface), and the forming burr is not generated, so that the optical element must be stopped. The case where the mass production step is stopped. In the method of the present invention, it is preferable that the rib formed by the surface formed by transferring the surface formed by the molding surface of the upper mold and the molding surface of the transfer body mold and/or the molding surface of the lower mold is transferred. The rib formed by the formed surface and the surface formed by the forming surface of the transfer body mold is a free surface, and the glass preform is subjected to precision press molding in this manner. As long as the side end and the flange flat portion are precisely formed as described above, the positioning function is not affected. For example, in the lens shown in Fig. 5, when the ridge portion 25 or the ridge portion 26 is sharp, when the holder is embedded There is a case where the rib is broken, or the edge scraping holder is used in the period of 21 - 200829522, resulting in dust. Since the dust adheres to the light receiving surface of the photographic element, the image quality is greatly lowered. In order to prevent such trouble, it is preferable to form an optical element having a ridge formed by a free surface. In addition, by making the ridge portion a free surface, even if a thousand-mass tolerance is generated between the preforms, the rib portion can exert a volume/adjustment effect, thereby avoiding insufficient filling of the formed burrs or the glass. The problem. • An optical multilayer film such as a reflection preventing film can be formed on the optical element thus manufactured as needed. (Embodiment) Hereinafter, the present invention will be described in more detail by way of examples, but the invention is not limited thereto. Example 1 (Production Example of Glass Preform Group) First, in order to obtain an optical glass having desired optical characteristics and glass transition temperature, the glass raw material was weighed and blended, and sufficiently stirred, and then introduced into The molten container is heated, melted, clarified, and stirred to obtain a uniform molten glass. The glass contained 'B2〇3, SiO2, BaO, Li20, and the refractive index nd was 1.58 3 13, and the Abbe's number d was 59.46. Using the apparatus shown in Fig. 1, 3 000 glass preforms having a target mass of 100 m g were produced from the above molten glass. Here, the glass melting device including the melting vessel is loaded on the anti-vibration table -22-200829522. An opening portion through which the tube 1 (for allowing the glass to flow down) is provided on the vibration isolating table, and the tube 1 is suspended from the container through the opening, and a nozzle 2 for discharging the molten glass is attached to the lower end of the tube 1. With the above configuration, the vibration from the building in which the above-described apparatus is installed can be blocked by the vibration-proof table, so that the vibration is not transmitted to the nozzle 2. • A molding die is disposed below the nozzle 2, and the lower end portion of the tube 1, the nozzle 2, and the molding die are disposed in a constant temperature chamber, and the internal atmosphere of the constant temperature Φ chamber is controlled by an air conditioner at a temperature of 25 ° C and a relative humidity of 10 ~95% range. According to the above configuration, the temperature and humidity in the vicinity of the flow outlet of the molten glass provided at the lower end of the nozzle 2 can be controlled, and the adhesion of the molten glass on the outer peripheral surface of the nozzle can be controlled to be constant. The molten glass is discharged from the nozzle 2 attached to the lower end of the tube 1 at a constant flow rate via the tube 1 connected to the bottom of the melting vessel. The temperature of each of the nozzle 2, the tube 1, and the molten container is controlled so that the glass does not devitrify and becomes a viscosity at which a desired outflow amount can be obtained. • As shown in Fig. 1, a gas flow path forming cover 3 is provided at the lower end of the pipe 1 and the outer periphery of the nozzle 2, and a gas is formed in a space between the pipe 1 and the nozzle 2 and the gas flow path forming cover 3. Flow path 4. Further, the lower end of the gas flow path forming cover 3 is provided with an opening 3 - 1 '. The tip end of the nozzle 2 protrudes from the opening. The nozzle 2, the gas flow path forming cover 3, and the gas flow path forming cover opening 3-1 are preferably arranged coaxially around the central axis of the nozzle 2, respectively. Further, it is preferable that the gas discharged from the gas flow path forming cover opening portion 3-1 is uniformly flowed around the central axis.
200829522 在本實施例中，調整管1的內徑、噴嘴2的 管1和噴嘴2的溫度並控制氣體的流出量，以值 的下端垂下的熔融玻璃以一定周期落下。從噴嘴 口流出的熔融玻璃在噴嘴的下端垂下，對垂下 璃，從氣體流路形成用蓋開口部3 -1以一定流量 出向下的氣體，藉此施加向下的風壓，而可獲得 璃滴。並且，只要用質量流量控制器等來控制氣 以使氣體流量一定，即可使玻璃滴的質量穩定化 如第1圖所示，在噴嘴2和氣體流路形成用 圍安裝有蓋5。蓋5覆蓋相當於從噴嘴2的下 口）到後述的成形模具的承接面的距離的1 /3〜 分，另外蓋5的上部封閉。蓋5的下方開口，g 擋熔融玻璃的滴下路徑。藉由蓋5降低外部氣# 外部干擾（例如噴嘴周圍的上升氣流），以在蓋 穩定狀態的氣氛，也使從氣體流路形成用蓋開口 出的氣體恒穩定地向下流動。 在蓋5的外側配置高頻感應線圈6並使 過，藉此對噴嘴2進行高頻感應加熱。較佳爲月 絕緣體來製造蓋5，以使其不會被感應加熱，們 體較佳爲使用石英玻璃等。當如上所述用透明 緣體來製造蓋5時，可以從外側觀察到蓋5的內 落下的熔融玻璃由待機在噴嘴下方的成形| 爲了使玻璃滴的質量穩定，使待機的成形模具& 玻璃下端的承接面與噴嘴下端的距離固定，由It 內外徑、 在噴嘴2 2的流出 的熔融玻 連續地噴 更輕的玻 體的流量 〇 蓋3的周 端（流出 1/2的部 此不會遮 ，所導致的 5內形成 部3-1噴 頻電流流 I耐熱性的 「爲該絕緣 丨耐熱性絕 部。 [具接住。 J承接熔融 :來承接落 -24- 200829522 下的熔融玻璃的下端，並利用熔融玻璃到達承接面時的衝 擊而使玻璃在線狀部分斷開。第3圖顯示上述成形模具的 垂直截面圖。用成形模具1 3的承接面1 3 -1來承接熔融玻 璃滴1 4。由於承接面1 3 -1朝設置成形模具〗3的上面所設 的凹部1 3 -2之底部方向傾斜，熔融玻璃滴〗4會從承接面 1 3 -1滑入（滾入）到凹部1 3 - 2內。 如第3圖所示，凹部13-2的截面具有從下向上擴展 爲喇叭狀的形狀’在凹部1 3 -2的底部設置有一個向上噴 出氣體的氣體噴出口。導入凹部1 3 - 2的熔融玻璃滴14， 朝向凹部底部一邊沿凹部內壁滾動一邊下降，由於凹部的 內徑隨著下行而減小，玻璃滴1 4越往下降受到的向上風 壓越強。結果’玻璃滴14在凹部13-2內上升，當上升時 向上的風壓變弱，所以再次一邊沿凹部內壁滾動一邊下 降。像這樣，玻璃滴1 4在短時間內重複以下運動：在凹 部內上升，然後一邊滾動一邊下降。由於熔融玻璃滴沿凹 部內壁滾動的方向是隨機的，所以在重複上述運動的過程 中玻璃滴1 4 一邊形成爲球狀一邊冷卻，而成形爲球狀預 製件。當冷卻到預製件不會變形的溫度時取出凹部1 3-2 內的預製件’並以玻璃不會破裂的速度將其冷卻至室溫。 藉由使用複數個成形模具來重複上述步驟，可量產相 等質量的球狀預製件。這樣，得到由3 000個平均質量 MAV爲l〇〇.16mg、質量公差的比例爲±0.2ΐχΜΑν%以內的 球狀光學玻璃製預製件所構成的預製件群。另外，上述平 均質量MAV和質量公差的比例，是從得到的複數個預製件 -25- 200829522 中取出500個而求出的値。 實施例2 (玻璃製預製件群的製造例） 除了使用含有 B2O3、Si〇2、La2〇3、ZnO、CaO、 U2O，折射率nd爲1.69350，阿貝數2^0爲53.20的光學 玻璃以外，與實施例1同樣地製造預製件群，得到由3000 個平均質量MAV爲99.88mg、質量公差的比例爲±〇.27x MAV%以內的球狀光學玻璃製預製件構成的預製件群。 另外，上述平均質量MAV和質量公差的比例，是從得 到的複數個預製件中取出5 0 0個而求出的値。 實施例3 (玻璃製預製件群的製造例） 除了使用含有 P2〇5、Nb205、Ti02、BaO、Li20，折 射率nd爲 1.82114，阿貝數vd爲24·06的光學玻璃以 外，與實施例1同樣地製造預製件群，得到由3 000個平 均質量MAV爲99.81mg、質量公差的比例爲±〇.31xMAV%以 內的球狀光學玻璃製預製件構成的預製件群。 另外，上述平均質量MAV和質量公差的比例，是從得 到的複數個預製件中取出500個而求出的値。 實施例4 (玻璃製預製件群的製造例） 除了不控制噴嘴2的下端（流出口）的溫度和濕度以 外，與實施例1〜3同樣地製造預製件群，得到由3 0 0 0個 平均質量MAV爲l〇〇.25mg、質量公差的比例爲±〇·43χ -26, 200829522200829522 In the present embodiment, the inner diameter of the tube 1, the temperature of the tube 1 of the nozzle 2, and the nozzle 2 are adjusted and the outflow amount of the gas is controlled, and the molten glass hanging down at the lower end of the value falls at a certain period. The molten glass that has flowed out from the nozzle opening hangs down at the lower end of the nozzle, and the downwardly flowing gas is discharged from the gas flow path forming cover opening portion 3-1 at a constant flow rate, thereby applying a downward wind pressure to obtain the glass. drop. Further, if the gas is controlled by a mass flow controller or the like so that the gas flow rate is constant, the quality of the glass drop can be stabilized. As shown in Fig. 1, the lid 5 is attached to the nozzle 2 and the gas flow path. The cover 5 covers 1 / 3 to a distance corresponding to the distance from the lower opening of the nozzle 2 to the receiving surface of a molding die to be described later, and the upper portion of the cover 5 is closed. The lower opening of the cover 5, g blocks the dropping path of the molten glass. The external air # external disturbance (e.g., the ascending airflow around the nozzle) is lowered by the cover 5, so that the gas which is opened from the gas flow path forming cover flows stably downward in the atmosphere in which the cover is in a stable state. The high frequency induction coil 6 is placed outside the cover 5, whereby the nozzle 2 is subjected to high frequency induction heating. Preferably, the cover 5 is made of a month insulator so that it is not heated by induction, and it is preferable to use quartz glass or the like. When the cover 5 is manufactured with a transparent edge as described above, the molten glass falling inside the cover 5 can be formed from the standby under the nozzle as viewed from the outside | In order to stabilize the quality of the glass drop, the standby molding die & The distance between the receiving surface of the lower end of the glass and the lower end of the nozzle is fixed, and the inner diameter of the inside of the nozzle and the molten glass flowing out of the nozzle 22 are continuously sprayed with the flow of the lighter glass body at the circumferential end of the cover 3 (the portion flowing out of 1/2) It does not cover, and the heat generation of the 5 internal forming portion 3-1 is limited to the heat resistance of the insulating 丨. [With the support. J undertakes melting: to undertake the fall of -24-200829522 The lower end of the molten glass is broken by the impact when the molten glass reaches the receiving surface, and the glass is broken in a line-like portion. Fig. 3 is a vertical sectional view showing the forming mold, which is received by the receiving surface 1 3 -1 of the forming mold 13 The molten glass drops 14 4. Since the receiving surface 13-1 is inclined toward the bottom direction of the concave portion 13-2 provided on the upper surface of the forming mold, the molten glass drop 4 is slid into the receiving surface 13-1 ( Roll in) into the recess 1 3 - 2. As shown in Figure 3 The cross section of the recess 13-2 has a shape that expands from a bottom to a flared shape. A gas discharge port that ejects gas upward is provided at the bottom of the recess 13-2. The molten glass drop 14 introduced into the recess 13-2 is oriented. The bottom of the recess descends along the inner wall of the recess, and as the inner diameter of the recess decreases as it goes down, the upward wind pressure that the glass drop 14 is lowered is stronger. As a result, the glass drop 14 rises in the recess 13-2. When the wind pressure rises upward, the wind pressure is weakened, so that it is lowered while rolling along the inner wall of the concave portion. Thus, the glass drop 14 repeats the following movement in a short time: it rises in the concave portion, and then falls while rolling. The direction in which the glass droplets roll along the inner wall of the concave portion is random, so that the glass droplets 14 are formed into a spherical shape while being cooled while being repeatedly formed, and are formed into spherical preforms. When cooled, the preforms are not deformed. At the temperature, the preform ' in the recess 1 3-2 is taken out and cooled to room temperature at a rate at which the glass does not break. The above steps can be repeated by using a plurality of forming dies, which can be mass-produced. A spherical preform of equal mass is obtained. Thus, a preform group composed of 3,000 spherical optical glass preforms having an average mass MAV of 1.06 mg and a mass tolerance of ±0.2 ΐχΜΑ% is obtained. In addition, the ratio of the average mass MAV and the mass tolerance is obtained by taking out 500 pieces of the plurality of preforms -25,295,522,22 obtained. Example 2 (Production Example of Glass Preform Group) Except for use A preform group was produced in the same manner as in Example 1 except that B2O3, Si〇2, La2〇3, ZnO, CaO, and U2O had an optical refractive index nd of 1.69350 and an Abbe number of 2^0 of 53.20. A preform group composed of a spherical optical glass preform having an average mass MAV of 99.88 mg and a mass tolerance ratio of ±〇.27x MAV%. Further, the ratio of the average mass MAV to the mass tolerance is obtained by taking out 500 pieces from a plurality of obtained preforms. Example 3 (Production Example of Glass Preform Group) Except that an optical glass containing P2〇5, Nb205, TiO2, BaO, and Li20, a refractive index nd of 1.82114, and an Abbe number vd of 24.06 was used, and examples 1 A preform group was produced in the same manner, and a preform group composed of 3,000 spherical optical glass preforms having an average mass MAV of 99.81 mg and a mass tolerance of ± 〇.31 x MAV% was obtained. Further, the ratio of the above average mass MAV to the mass tolerance is obtained by taking out 500 of the plurality of preforms obtained. Example 4 (Production Example of Glass Preform Group) A preform group was produced in the same manner as in Examples 1 to 3 except that the temperature and humidity of the lower end (outlet) of the nozzle 2 were not controlled, and 300 parts were obtained. The average mass MAV is l〇〇.25mg, and the ratio of mass tolerance is ±〇·43χ -26, 200829522
Mav%以內的球狀的光學玻璃製預製件構成的複數個1預_ 件群。 另外，上述平均質量M A V和質量公差的比例’是從得 到的複數個預製件群中分別取出5 00個而求出的値° 實施例5 (玻璃製預製件群的製造例） 除了不設置防振台以外，與實施例1〜3同樣地製造 預製件群，得到由3000個平均質量MAV爲100.38mg、質 量公差的比例爲±〇·47 xMAV%以內的球狀光學玻璃製預製 件構成的複數個預製件群。 另外，上述平均質量MAV和質量公差的比例。是從得 到的複數個預製件群中分別取出500個而求出的値。 比較例1 (玻璃製預製件群的製造例） 除了不控制噴嘴2的下端（流出口）的溫度和濕度、 不設置防振台以外，與實施例1〜3同樣地製造預製件 群，得到由3000個平均質量MAV爲100.74mg、質量公差 的比例爲±0.7 9x M AV%以內的球狀光學玻璃製預製件構成 的複數個預製件群。 另外，上述平均質量MAv和質量公差的比例，是.從得 到的各個預製件群中分別取出5 〇〇個而求出的値。 實施例6 (光學元件的製造例） 使用在實施例1〜5中得到的各個預製件群，藉由精 -27- 200829522 密模壓成形分別製造具有第5圖所示截面形狀的小型非球 面透鏡。任何一個透鏡均未觀察到破損，並且都具有透鏡 所要求的充分的光學性能。另外，各個透鏡的側端24、突 緣平坦部22，係轉印模壓成形模具的成形面而成者，側端 24和突緣平坦部22相交的稜部25成爲帶圓角的自由表 面。可確認出在各個透鏡上未產生成形毛邊。 這些非球面透鏡，具備行動電話中內設的攝影裝置的 攝影光學系統的透鏡之作用。將所製得的透鏡、和除了形 狀以外以完全相同的方法製造的具有側端和突緣平坦部 (作爲定位基準面）的透鏡，組裝到透鏡保持具，並在使 定位基準面與保持具抵接的狀態下進行固定，藉此能將各 透鏡正確地排列在保持具內。 將上述實施例1〜5和比較例1進行對比可知，藉由 對熔融玻璃的流出口採取防振措施及/或控制其氣氛溫度 和濕度’即使得到的構成預製件群的預製件的平均質量小 至100mg的程度時，也可以降低預製件之間的質量公差。 另外，由上述實施例6可知，能夠以高量產性由上述各個 預製件群製造出高精度的光學元件。 依據本發明可提供：各個預製件間的體積偏差受到了 極爲嚴格的控制的精密模壓成形用玻璃製預製件群、以高 生產率由熔融玻璃來製造該預製件群的方法、以及由上述 預製件群或者由上述方法製得的預製件群中的預製件來製 造光學元件的方法。 •28- 200829522 【圖式簡單說明】 第1圖是用於說明本發明的玻璃製預製件群之製造方 法的槪略圖。 第2圖是用於說明本發明的玻璃製預製件群之製造方 _ 法的槪略圖。 ‘第3圖是用於說明本發明的玻璃製預製件群之製造中 所使用的成形模具一例的槪略圖。 • 第4圖是用於說明本發明的光學元件之製造方法的槪 略圖。 第5圖是用於說明本發明的方法所製得的光學元件的 一例的槪略圖。 【主要元件符號說明】 1 :管 2 :噴嘴 • 3 ··氣體流路形成用蓋 3 -1 :開口部 4 :氣體流路 5 ··蓋 6 :高頻感應線圈 I 0 :熔融裝置 II :防振台 1 2 :恒溫室 Ϊ 3 :成形模具 29- 200829522 1 3 - 1 :承接面 13-2 :凹部 1 4 :熔融玻璃滴 15 :體模具 β 16 :下模具 _ 1 7 :上模具 1 8 :推桿 • 1 9 :玻璃製預製件 2 0、21 :透鏡面 22、23 :突緣狀平坦部 24 :側端 2 5、2 6 :稜部 -30A plurality of 1 pre-forms composed of spherical optical glass preforms within Mav%. In addition, the ratio "the ratio of the average mass MAV to the mass tolerance" is obtained by taking out 500 pieces from the plurality of preform groups obtained. Example 5 (Production Example of Glass Preform Group) In the same manner as in the first to third embodiments, a preform group was produced in the same manner as in the first to third embodiments, and a spherical optical glass preform having a mass ratio of 3000 to 38.30 mg and a mass tolerance of ±〇·47 xMAV% was obtained. A plurality of prefabricated groups. In addition, the ratio of the above average mass MAV to the mass tolerance. It is obtained by taking out 500 pieces from a plurality of prefabricated parts obtained. Comparative Example 1 (Production Example of Glass Preform Group) A preform group was produced in the same manner as in Examples 1 to 3 except that the temperature and humidity of the lower end (outlet) of the nozzle 2 were not controlled, and the vibration isolating stage was not provided. A plurality of preform groups composed of 3000 spherical optical glass preforms having an average mass MAV of 100.74 mg and a mass tolerance ratio of ±0.7 9 x M AV%. Further, the ratio of the average mass MAv to the mass tolerance is obtained by taking out 5 pieces from each of the obtained preform groups. Example 6 (Production Example of Optical Element) Using each of the preform groups obtained in Examples 1 to 5, a small aspherical lens having a cross-sectional shape shown in Fig. 5 was separately produced by precision molding from -27 to 200829522. . No damage was observed in any of the lenses and both had sufficient optical properties required by the lens. Further, the side end 24 of each lens and the flange flat portion 22 are formed by transferring the molding surface of the press molding die, and the edge portion 25 where the side end portion 24 and the flange flat portion 22 intersect is a free surface having rounded corners. It was confirmed that no formed burrs were formed on the respective lenses. These aspherical lenses function as lenses of a photographic optical system of a photographing device provided in a mobile phone. The lens obtained and the lens having the side end and the flange flat portion (as a positioning reference surface) manufactured in the same manner except for the shape are assembled to the lens holder, and the positioning reference surface and the holder are placed The fixing is performed in the abutting state, whereby the lenses can be correctly aligned in the holder. Comparing the above Examples 1 to 5 with Comparative Example 1, it is understood that the average quality of the preforms constituting the preform group is obtained by taking anti-vibration measures for the outlet of the molten glass and/or controlling the temperature and humidity of the atmosphere. As small as 100 mg, the quality tolerance between the preforms can also be reduced. Further, as is apparent from the above-described sixth embodiment, it is possible to manufacture a high-precision optical element from each of the above-described preform groups with high productivity. According to the present invention, there is provided a glass preform preform for precision press molding in which the volume deviation between the respective preforms is extremely strictly controlled, a method of manufacturing the preform group from molten glass with high productivity, and the above-described preform A method of manufacturing an optical component by a group or a preform in a preform group produced by the above method. • 28-200829522 [Brief Description of the Drawings] Fig. 1 is a schematic view for explaining a method of manufacturing a glass preform group of the present invention. Fig. 2 is a schematic view for explaining the manufacturing method of the glass preform group of the present invention. The third drawing is a schematic view for explaining an example of a molding die used in the production of the glass preform group of the present invention. Fig. 4 is a schematic view for explaining the method of manufacturing the optical element of the present invention. Fig. 5 is a schematic view showing an example of an optical element produced by the method of the present invention. [Description of main component symbols] 1 : Tube 2 : Nozzle • 3 · Gas flow path forming cover 3 -1 : Opening 4 : Gas flow path 5 · · Cover 6 : High frequency induction coil I 0 : Melting device II : Anti-vibration table 1 2 : Constant temperature chamber Ϊ 3 : Molding mold 29 - 200829522 1 3 - 1 : Bearing surface 13-2 : Concave portion 1 4 : Molten glass drop 15 : Body mold β 16 : Lower mold _ 1 7 : Upper mold 1 8: Pusher • 1 9 : Glass preform 2 0, 21: Lens surface 22, 23: flange-like flat portion 24: side end 2 5, 2 6 : rib -30