JP2002338272A - Manufacturing aperture and manufacturing method for optical element - Google Patents
Manufacturing aperture and manufacturing method for optical elementInfo
- Publication number
- JP2002338272A JP2002338272A JP2001146478A JP2001146478A JP2002338272A JP 2002338272 A JP2002338272 A JP 2002338272A JP 2001146478 A JP2001146478 A JP 2001146478A JP 2001146478 A JP2001146478 A JP 2001146478A JP 2002338272 A JP2002338272 A JP 2002338272A
- Authority
- JP
- Japan
- Prior art keywords
- mold
- glass
- optical
- molding
- manufacturing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B11/00—Pressing molten glass or performed glass reheated to equivalent low viscosity without blowing
- C03B11/06—Construction of plunger or mould
- C03B11/08—Construction of plunger or mould for making solid articles, e.g. lenses
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B2215/00—Press-moulding glass
- C03B2215/67—Pressing between dies rotating about the press axis
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Re-Forming, After-Treatment, Cutting And Transporting Of Glass Products (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、レンズやプリズム
などの高精度な光学ガラス素子を、プレス成形型によっ
て、熱間でプレス成形する光学ガラス素子のプレス成形
方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for press-molding an optical glass element such as a lens or a prism with high precision using a press mold.
【０００２】[0002]
【従来の技術】軟化させたガラスゴブを一対の成形型に
より押圧プレスするガラスモールド成形法では、従来、
ゴブ容量のぱらつきを吸収する目的で、光学有効径外の
レンズコバ部に余剰ガラス部分を設け成形が行われてい
た。ここで、余剰ガラス部分とは、プレス時に光学有効
径外にはみ出したガラス部分を指し、その概略図を縦断
面図として図５に示す。図中、２６が余剰ガラス部分、
２７は上成形型、２８は下成形型、２９はプレスレンズ
である。2. Description of the Related Art In a glass molding method in which a softened glass gob is pressed and pressed by a pair of molding dies, conventionally,
For the purpose of absorbing the fluctuation of the gob capacity, an extra glass portion is provided in a lens edge portion outside the optical effective diameter, and molding is performed. Here, the surplus glass portion refers to a glass portion that has protruded outside the optical effective diameter during pressing, and a schematic diagram thereof is shown in FIG. 5 as a longitudinal sectional view. In the figure, 26 is the surplus glass part,
27 is an upper mold, 28 is a lower mold, and 29 is a press lens.
【０００３】ここで、図に示したようなレンズコバ部の
肉厚がレンズ中心厚に比して小さいレンズ形状、いわゆ
る凸レンズ形状の場合を考えると、レンズコバ部よりも
中心部の厚さが大きいため、冷却過程において、双方の
熱収縮量に差が生じる。図中△１中心および△１コパ
を、それぞれプレス軸方向におけるレンズ中心部分とコ
バ部分の熱収縮量とすれば、△１中心＞△１コパの関係
が、冷却中、常に成り立っている。したがって、上下成
形型が上下方向の摺動に対し自由であれば、レンズ中心
部分とコバ部分との熱収縮量の差をコバ部分で支えるよ
うな応力状態、すなわち、上下成形型によりレンズコバ
部に対しプレス軸方向の圧縮力が負荷された状態とな
る。前記圧縮力がレンズコバ部に負荷されると、上下の
成形型がレンズコパ部を挟み込み、離型性を悪化させる
要因となる。離型が冷却しても生じない場合、余剰ガラ
ス部分と光学有効径内との境界で、熱収縮によるガラス
内部のひずみが大きくなり、その結果、ワレが発生し易
くなる。Here, considering the case of a lens shape in which the thickness of the lens edge portion as shown in the figure is smaller than the center thickness of the lens, that is, a so-called convex lens shape, the thickness of the central portion is larger than that of the lens edge portion. In the cooling process, a difference occurs between the two heat shrinkage amounts. In the drawing, if the # 1 center and the # 1 copa are the heat contraction amounts of the lens center portion and the edge portion in the press axis direction, respectively, the relationship of # 1 center># 1 copa always holds during cooling. Therefore, if the upper and lower molds are free to slide in the vertical direction, a stress state in which the difference in the amount of heat shrinkage between the lens center portion and the edge portion is supported by the edge portion, that is, the upper and lower molds cause On the other hand, the compression force in the press axial direction is applied. When the compressive force is applied to the lens edge portion, the upper and lower molds sandwich the lens edge portion, which is a factor of deteriorating the releasability. If mold release does not occur even after cooling, distortion inside the glass due to heat shrinkage increases at the boundary between the surplus glass portion and the optically effective diameter, and as a result, cracks are likely to occur.
【０００４】離型せずにワレが発生し易くなるのは凸レ
ンズ形状に限ったことではなく、レンズコバ部が薄くな
っている凹レンズ形状でも多く見られる。この場合、レ
ンズ中心部分からワレが発生する場合が多い。It is not limited to the convex lens shape that cracks easily occur without releasing the mold, and it is often seen in the concave lens shape in which the lens edge portion is thin. In this case, cracks often occur from the center of the lens.
【０００５】特開平８−３４６２７号公報によるワレを
防止する試みは、有効径内と外で熱膨張係数の異なる型
材を使用することによって行われているが、離型させる
温度を制御することは難しく、成形するガラス材料によ
っては、ワレが発生する前に離型できない場合がある。
そのため、所望の温度範囲で離型させることが可能な手
段が必要であった。An attempt to prevent cracking according to Japanese Patent Application Laid-Open No. 8-34627 has been made by using mold materials having different thermal expansion coefficients inside and outside the effective diameter. However, it is not possible to control the temperature at which the mold is released. It is difficult, and depending on the glass material to be molded, it may not be possible to release the mold before cracking occurs.
Therefore, a means capable of releasing the mold in a desired temperature range is required.
【０００６】[0006]
【発明が解決しようとする課題】上記従来技術では、は
み出し部が上下型により圧縮力を受けたり、コバの肉厚
が薄いと、ガラス／成形型界面における離型が困難とな
り、レンズのワレが生じ易いという問題があつた。In the prior art described above, if the protruding portion is subjected to a compressive force by the upper and lower molds or if the thickness of the edge is thin, it becomes difficult to release the mold at the glass / molding interface, and the lens cracks. There was a problem that it easily occurred.
【０００７】[0007]
【課題を解決するための手段】本発明は、押圧プレス後
のガラスゴブを冷却する工程において、光軸中心を軸と
してプレス面の一部を回転させることで、ガラス／成形
型界面の離型を促進し、レンズのワレを防止するもので
ある。According to the present invention, in a step of cooling a glass gob after a press, a part of a press surface is rotated about an optical axis as an axis to release the glass / mold interface. It promotes and prevents cracking of the lens.
【０００８】上記プレス面の回転を行うため、上下成形
型の少なくとも一方の成形型を、同心円状に第一、第二
に分割して構成し、前記第一の成形型は少なくとも光学
有効面を形成し、前記第二の成形型は少なくとも光学有
効径外の一部分を形成し、かつ第二の成形型は第一の成
形型の周囲を回転摺動可能である光学素子の製造装置を
用いる。In order to rotate the press surface, at least one of the upper and lower molds is concentrically divided into first and second parts, and the first mold has at least an optically effective surface. The second mold uses an optical element manufacturing apparatus that forms at least a part outside the optical effective diameter, and the second mold is capable of rotating and sliding around the first mold.
【０００９】プレス面の回転による離型を、ガラスの粘
度が１０１１（ｄＰａ・ｓ）以下となる温度範囲で行う
と、回転による変形で応力が発生し有効径外を離型させ
ることができ、一度離型したガラスと型とが再び密着す
ることもない。When the mold release by rotation of the press surface is performed in a temperature range in which the viscosity of the glass is 10 11 (dPa · s) or less, stress is generated by the deformation due to the rotation and the outside of the effective diameter can be released. Also, the glass once released and the mold do not adhere again.
【００１０】分割された第一と第二の成形型との間隙に
軟化したガラスが流入するのを防止するため、および熱
収縮による間隙での締め付けを防止するため、同心円状
に配置された２つの成形型の熱膨張係数は、外側よりも
内側の方が大きくなるように構成する。In order to prevent the softened glass from flowing into the gap between the divided first and second molds, and to prevent the glass from being tightened in the gap due to heat shrinkage, two concentrically arranged two pieces are arranged. The two molds are configured so that the coefficient of thermal expansion is larger on the inside than on the outside.
【００１１】[0011]
【作用】本発明により、ガラス内部の熱ひずみが十分に
小さい温度において、レンズコバ部のガラス／成形型界
面を離型させると、レンズコバ部と光学有効径内との境
界付近に発生していた熱ひずみを解放させることができ
る。そのため、レンズコバ部周辺のワレが防止でき、し
かも、コバの部分を離型させることで生じたガラス／成
形型界面におけるき裂は、光学有効径内を容易に進展し
ていくため、レンズ全体のワレを防止する効果も得られ
る。According to the present invention, when the glass / mold interface at the lens edge is released at a temperature at which the thermal strain inside the glass is sufficiently small, the heat generated near the boundary between the lens edge and the optical effective diameter is released. The strain can be released. For this reason, cracks around the lens edge can be prevented, and a crack at the glass / mold interface generated by releasing the edge easily advances within the effective optical diameter. An effect of preventing cracking can also be obtained.
【００１２】本発明は光学有効径外のみを離型させるた
め、光学有効径内にキズを与えることがなく、さらに、
ねじり負荷を与えていることから、離型開始箇所である
レンズ外周部に最大のせん断力を負荷できる利点があ
る。また、上下成形型に回転摺動可能な型を配置すれ
ば、前記回転摺動可能な型を上下逆回転させることで、
光学有効径内に生じる応力を抑えることができ、回転体
により与えたねじり負荷がワレを生じさせること、なら
びに屈析率を変化させるような過度の応力が生じること
もない。In the present invention, only the outside of the effective optical diameter is released, so that the inside of the effective optical diameter is not damaged.
Since the torsional load is applied, there is an advantage that a maximum shearing force can be applied to the outer peripheral portion of the lens, which is a part where mold release is started. In addition, if a rotatable mold is arranged in the upper and lower molds, the rotatable mold is rotated upside down,
The stress generated within the effective optical diameter can be suppressed, and the torsional load given by the rotating body does not cause cracking and does not generate excessive stress that changes the rate of segregation.
【００１３】[0013]
【発明の実施の形態】（形態例１）図１は、この発明の
実施の第１形態例で使用した本発明の離型部材を含む型
構造の例を、縦断面と上面の概略図で示したものであ
る。１，２はそれぞれ光学機能転写面を有する上、下成
形型である。本形態例では、上下成形型を凹面形状に加
工し、両凸レンズを成形した。成形型に使用する材料
は、超硬合金、セラミック、金属等のいずれでも良い。
３はプレスレンズ、４は上型に嵌合された回転摺動可能
な離型部材であり、５は下型に嵌合された同部材であ
る。(Embodiment 1) FIG. 1 is a schematic diagram of a vertical cross section and a top view of an example of a mold structure including a release member of the present invention used in a first embodiment of the present invention. It is shown. Reference numerals 1 and 2 denote upper and lower molds each having an optical function transfer surface. In the present embodiment, the upper and lower molds were processed into a concave shape to form a biconvex lens. The material used for the mold may be any of cemented carbide, ceramic, metal and the like.
Reference numeral 3 denotes a press lens, 4 denotes a release member which is fitted to the upper die and is slidable, and 5 denotes the same member which is fitted to the lower die.
【００１４】離型部材４，５は耐熱性に優れた材料であ
れば特に隈定はないが、熱膨張係数は成形型１，２より
も大きくならないようにする。これは、成形型の昇温に
伴い、成形型と離型部材との嵌合部位における間隙が広
がり、プレス時にガラスが流れ込まないようにするため
である。The release members 4 and 5 are not particularly limited as long as they are materials having excellent heat resistance, but the thermal expansion coefficient should not be larger than that of the molds 1 and 2. This is because the gap in the fitting portion between the mold and the release member is widened as the temperature of the mold rises, so that the glass does not flow during pressing.
【００１５】離型部材４，５のプレス面に関しては、ガ
ラスとの密着力を低減させる薄膜を配すれば、より小さ
い負荷によっても離型できるため、ガラスヘの負担が減
り不良品の発生を防止できる。６は成形型１，２および
離型部材４，５を案内するための胴型である。７は抵抗
発熱体であり、成形型１，２の温度を制御できるように
なっている。With respect to the pressed surfaces of the release members 4 and 5, if a thin film for reducing the adhesion to the glass is provided, the release can be performed with a smaller load, so that the load on the glass is reduced and the occurrence of defective products is prevented. it can. Reference numeral 6 denotes a body die for guiding the molds 1 and 2 and the release members 4 and 5. Reference numeral 7 denotes a resistance heating element which can control the temperatures of the molds 1 and 2.
【００１６】本形態例で行った光学素子の成形工程は大
きく分けると、次の２工程となる。 （１）加熱され軟化したガラスゴブに光学機能面を転写
させる押圧プレス工程。 （２）押圧プレス後のレンズを冷却しつつ、レンズの面
精度を確保するためにプレスする、および離型部材４，
５により光学有効径外を離型させ、全面が離型するまで
冷却し続ける工程。The optical element forming steps performed in this embodiment can be roughly divided into the following two steps. (1) A pressing press step for transferring an optically functional surface to a heated and softened glass gob. (2) While cooling the lens after pressing, press to ensure the surface accuracy of the lens;
Step 5 of releasing the outside of the optically effective diameter and continuing cooling until the entire surface is released.
【００１７】なお、成形は窒素雰囲気中で行い、成形型
とガラスの反応を抑制している。硝材にはＳＫ１２（Ｔ
ｇ＝５５０℃）を用いた。The molding is performed in a nitrogen atmosphere to suppress the reaction between the molding die and the glass. SK12 (T
g = 550 ° C.).
【００１８】以下では、図１を参照しながら成形工程
（１）（２）を具体的に説明する。（１）の工程では、
７の加熱手段により成形型１，２およびカラスゴブを加
熱する。ここでは、用いた硝材が軟化する温度（＝６１
４℃）まで温度を上昇させた。その後、図示されていな
い加圧手段により、１の成形型を介してガラスゴブを押
圧プレスし、１，２の成形型に加工された光学機能面を
ガラスに転写させた。（２）の工程は、押圧プレス後の
ガラスを冷却し、型とガラスの熱膨張係数の差により生
じる応力を利用することで、ガラス／成形型界面を離型
させる工程である。Hereinafter, the molding steps (1) and (2) will be specifically described with reference to FIG. In step (1),
The heating means 7 heats the molds 1 and 2 and the rasgob. Here, the temperature at which the used glass material softens (= 61)
(4 ° C.). Thereafter, the glass gob was pressed and pressed through one molding die by a pressing means (not shown), and the optical functional surfaces processed into the first and second molding dies were transferred to glass. The step (2) is a step of cooling the glass after the press press and releasing the glass / mold interface by utilizing a stress generated by a difference in thermal expansion coefficient between the mold and the glass.
【００１９】この工程では、熱収縮によるガラスのヒケ
が転写精度を悪化させるのを防止するため、図示されて
いない加圧手段によって、２の成形型を介し冷却中のガ
ラスに対し５〜１０（ＭＰａ）の圧縮応力を負荷した。
本形態例では、このプレスをガラスが粘性を示す温度か
ら、ほとんど粘性が無視できる温度である、５７０〜５
３０℃の範囲で行った。工程（２）の冷却速度は１０
（℃／ｍｉｎ）で一定としている。離型部材の回転制御
は電動サーボで行い、回転数が０．１（ｒｐｍ）となる
ようにし、回転角は最大２０度とした。以上の成形工程
を温度と時間の関係としてまとめると図２のようにな
る。In this step, in order to prevent the sink mark of the glass due to the heat shrinkage from deteriorating the transfer accuracy, 5-10 ( (MPa) compressive stress was applied.
In this embodiment, the temperature of the press is from 570 to 570 to a temperature at which the viscosity is almost negligible.
The test was performed in the range of 30 ° C. The cooling rate in step (2) is 10
(° C./min). The rotation of the release member was controlled by an electric servo so that the number of rotations was 0.1 (rpm) and the rotation angle was a maximum of 20 degrees. FIG. 2 summarizes the above molding process as a relationship between temperature and time.
【００２０】図２の成形工程に基づき、離型部材４，５
を回転させ成形を行った場合と、比較として離型部材を
回転させずに成形した場合とで実験を行った。このと
き、離型部材の回転を開始するときのガラス粘度を変化
させ、その変化が離型温度へ及ぼす影響についても検討
を行った。それらの結果を表１に示す。Based on the molding process shown in FIG.
The experiment was conducted in a case where the molding was performed by rotating the mold, and in a case where the molding was performed without rotating the release member for comparison. At this time, the viscosity of the glass when the rotation of the release member was started was changed, and the effect of the change on the release temperature was also examined. Table 1 shows the results.
【００２１】[0021]
【表１】 [Table 1]
【００２２】ガラス粘度が１０１１（ｄＰａ・ｓ）以下
で離型部材の回転を行った場合は５００℃で全面が離型
し、その他の条件で成形を行うと３５０℃で全面が離型
した。サンプル数１００個におけるワレ発生率をみる
と、ガラス粘度が１０１１（ｄＰａ・ｓ）以下で離型部
材の回転を行った場合は０％、その他の条件で成形を行
うと１０％という結果であった。これらの結果から、ガ
ラス粘度が１０１１（ｄＰａ・ｓ）以下となる温度で離
型部材の回転を行うと離型温度改善およびワレ防止に効
果があることがわかった。離型部材４，５の回転は、工
程（２）のどの温度においても実行可能であるが、ガラ
スの粘度が低い状態で行うと、応力が生じず離型部材を
回転させても有効径外を離型させることができない。ま
た、一度離型させても再び密着してしまう場合があり、
回転させる意味がない。When the releasing member is rotated at a glass viscosity of 10 11 (dPa · s) or less, the entire surface is released at 500 ° C., and when the molding is performed under other conditions, the entire surface is released at 350 ° C. . Looking at the crack generation rate at 100 samples, the result is 0% when the mold release member is rotated at a glass viscosity of 10 11 (dPa · s) or less, and 10% when the molding is performed under other conditions. there were. From these results, it was found that rotating the release member at a temperature at which the glass viscosity was 10 11 (dPa · s) or less was effective in improving the release temperature and preventing cracking. The rotation of the release members 4 and 5 can be performed at any temperature in the step (2). However, when the release members 4 and 5 are rotated in a state where the viscosity of the glass is low, no stress is generated and even if the release members are rotated, the effective diameter is not increased. Cannot be released from the mold. In addition, even if it is released once, it may adhere again,
There is no point in rotating.
【００２３】（形態例２）次に、この発明の実施の第２
形態例で用いた、本発明の製造装置における型構造の別
例を縦断面の概略図として図３に示す。本形態例の型構
造は、８，９で示すプレス上、下軸の周囲に、１０，１
１で示す円筒部材が配され、この円筒部材に直接、１
２，１３で示すレンズ光学有効径外を離型させる、同じ
く円筒状の離型部材がボルトにより固定されている。１
４，１５は光学機能転写面を有する上下の成形型であ
り、その直径は光学有効径と同じとした。円筒部材１
０，１１のいずれかを、図示されていない電動サーボに
よって回転させると、光学有効径外のガラス／成形型界
面にねじり負荷を与えることができる構造である。１６
はプレスレンズであり、成形型１４，１５のプレス面が
転写されたことで凸メニスカスレンズ形状となってい
る。(Embodiment 2) Next, a second embodiment of the present invention will be described.
Another example of the mold structure in the manufacturing apparatus of the present invention used in the embodiment is schematically shown in FIG. The mold structure of the present embodiment is formed by pressing the presses indicated by 8, 9 around the lower shaft,
A cylindrical member indicated by 1 is disposed, and 1
Similarly, cylindrical release members for releasing the outside of the lens optical effective diameter indicated by reference numerals 2 and 13 are fixed by bolts. 1
Reference numerals 4 and 15 denote upper and lower molds having an optical function transfer surface, the diameter of which is the same as the optical effective diameter. Cylindrical member 1
When any one of the motors 0 and 11 is rotated by an electric servo (not shown), a torsional load can be applied to the glass / mold interface outside the optical effective diameter. 16
Denotes a press lens, which has a convex meniscus lens shape by transferring the press surfaces of the molds 14 and 15.
【００２４】離型部材１２，１３は耐熱性に優れた材料
であれば特に限定はないが、熱膨張係数は、形態例１で
述べたように、成形型１４，１５の熱膨張係数よりも大
きくならないような材料を選択する。The release members 12 and 13 are not particularly limited as long as they are excellent in heat resistance. However, as described in the first embodiment, the thermal expansion coefficient is lower than the thermal expansion coefficients of the molds 14 and 15. Select a material that does not grow.
【００２５】ガラスと接触するプレス面に関しては、ガ
ラス／離型部材との密着力を低減させる薄膜を配すれ
ば、より小さい負荷で離型できるため、ガラスヘの負担
は低減し、不良品の発生を防止できる。With respect to the press surface which comes into contact with the glass, if a thin film for reducing the adhesive force between the glass and the release member is provided, the release can be performed with a smaller load. Can be prevented.
【００２６】ここで、形態例１で行った比較実験と同じ
く、図２に示した成形工程に基づき、離型部材１２，１
３を回転させた場合と、回転させなかった場合とで比較
実験を行った。なお、離型部材の回転は、ガラス粘度が
１０１１（ｄＰａ・ｓ）となる５８０℃で行い、回転数
を０．１（ｒｐｍ）、回転角を最大２０度とした。その
結果を表２に示す。Here, as in the comparative experiment performed in the first embodiment, the release members 12, 1 are formed based on the molding process shown in FIG.
A comparative experiment was performed between the case where 3 was rotated and the case where it was not rotated. The rotation of the release member was performed at 580 ° C. where the glass viscosity was 10 11 (dPa · s), the rotation number was 0.1 (rpm), and the rotation angle was 20 degrees at maximum. Table 2 shows the results.
【００２７】[0027]
【表２】 [Table 2]
【００２８】離型部材１２，１３を回転させ成形を行っ
た場合は、５１０℃で全面が離型し、回転させずに成形
を行うと、４００℃で全面が離型した。成形サンプル数
を１００個としてワレの発生率を調べると、光学有効径
外を離型させ成形を行った場合は０％、光学有効径外を
離型させずに成形を行うと５％という結果であった。本
形態例の成形条件の場合、離型部材を回転させ光学有効
径外を離型させると、離型させない場合に比ベ、離型温
度が１１０℃上昇しワレの発生が防止できた。When molding was performed by rotating the release members 12 and 13, the entire surface was released at 510 ° C., and when the molding was performed without rotating, the entire surface was released at 400 ° C. When the incidence of cracks is examined with the number of molded samples set to 100, the result is 0% when molding is performed by releasing the outside of the optically effective diameter, and 5% when molding is performed without releasing the outside of the optically effective diameter. Met. In the case of the molding conditions of this embodiment, when the release member was rotated to release the outside of the optically effective diameter, the release temperature was increased by 110 ° C. as compared with the case where the release was not performed, thereby preventing the occurrence of cracks.
【００２９】（形態例３）第３の形態例で用いた、本発
明の製造装置における型構造の別例を縦断面の概略図と
して図４に示す。図中、１７，１８はプレス上、下軸で
あり、その周囲に１９，２０で示す円筒部材が配され、
この円筒部材に直接、２１，２２で示すレンズ光学有効
径外を離型させる離型部材がボルトにより固定されてい
る。２３，２４は光学機能転写面を有する上下の成形型
であり、その直径は光学有効径と同じとした。円筒部材
１９，２０のいずれかを、図示されていない電動サーボ
等の手段によって回転させると、光学有効径外のガラス
／成形型界面にねじり負荷を与えることができる構造で
ある。２５はコバ部分が薄くなっている平凹形状のプレ
スレンズである。(Embodiment 3) Another example of the mold structure in the manufacturing apparatus of the present invention used in the third embodiment is schematically shown in FIG. In the drawing, reference numerals 17 and 18 denote upper and lower shafts, around which cylindrical members indicated by 19 and 20 are arranged.
A release member for releasing the outside of the lens optical effective diameter indicated by 21 and 22 is directly fixed to this cylindrical member by bolts. Reference numerals 23 and 24 denote upper and lower molds having an optical function transfer surface, the diameter of which is the same as the optical effective diameter. When any one of the cylindrical members 19 and 20 is rotated by means such as an electric servo (not shown), a torsional load can be applied to the glass / mold interface outside the effective optical diameter. Reference numeral 25 denotes a plano-concave press lens whose edge portion is thin.
【００３０】離型部材２１，２２は耐熱性に優れた材料
であれば特に限定はないが、熱膨張係数は、形態例１で
述べたように、成形型２３，２４の熱膨張係数よりも大
きくならない材料を選択する。The release members 21 and 22 are not particularly limited as long as they are excellent in heat resistance. However, as described in the first embodiment, the thermal expansion coefficient is lower than the thermal expansion coefficients of the molds 23 and 24. Select a material that does not grow.
【００３１】ガラスと接触するプレス面に関しては、ガ
ラス／離型部材との密着力を低減させる薄膜を配すれ
ば、より小さい負荷で離型できるため、ガラスヘの負担
は低減し、不良品の発生を防止できる。With respect to the press surface which comes into contact with the glass, if a thin film for reducing the adhesive force between the glass and the release member is provided, the release can be performed with a smaller load, so that the load on the glass is reduced, and defective products are generated. Can be prevented.
【００３２】以下では、形態例１で行った比較実験と同
じく、図２に示した成形工程に基づき、離型部材２１，
２２を回転させた場合と、回転させずに成形した場合と
の比較を行い、平凹レンズの成形に対する離型部材の有
効性を示す。なお、離型部材の回転は、ガラス粘度が１
０１１（ｄＰａ・ｓ）となる５８０℃で行い、回転数を
０．１（ｒｐｍ）、回転角を最大２０度とした。その結
果は表３である。In the following, as in the comparative experiment performed in the first embodiment, based on the molding step shown in FIG.
A comparison is made between the case where the mold 22 is rotated and the case where the mold is formed without being rotated, and shows the effectiveness of the mold release member with respect to the molding of the plano-concave lens. The rotation of the release member is performed when the glass viscosity is 1.
This was performed at 580 ° C., where 0 11 (dPa · s), the number of rotations was set to 0.1 (rpm), and the rotation angle was set to a maximum of 20 degrees. Table 3 shows the results.
【００３３】[0033]
【表３】 [Table 3]
【００３４】全面が離型する温度に関して、光学有効径
外を離型させ成形を行った場合は、５２０℃で全面が離
型し、光学有効径外を離型させずに成形を行うと、３６
０℃で全面が離型した。With respect to the temperature at which the entire surface is released, when molding is performed by releasing the outside of the optically effective diameter, the entire surface is released at 520 ° C. and molding is performed without releasing the outside of the optically effective diameter. 36
The whole surface was released at 0 ° C.
【００３５】成形サンプル数を１００個としてワレの発
生率を調べると、光学有効径外を離型させ成形を行った
場合は０％、光学有効径外を離型させずに成形を行うと
８％という結果であった。本形態例の成形条件の場合、
離型部材により光学有効径外を離型させると、離型させ
ない場合に比ベ、離型温度が１６０℃上昇しワレの発生
が防止できた。When the occurrence rate of cracks is examined by setting the number of molded samples to 100, 0% is obtained when molding is performed by releasing the outside of the effective optical diameter, and 8% when molding is performed without releasing the outside of the effective optical diameter. %. In the case of the molding conditions of this embodiment,
When the outside of the optically effective diameter was released by the release member, the release temperature was raised by 160 ° C. as compared with the case where the release was not performed, and generation of cracks could be prevented.
【００３６】以上の結果のように、第１．２の形態例で
示した凸レンズ形状に限らず、平凹形状およびその他の
形状に対しても、光学有効径外を離型させ、光学有効径
内へのき裂の進展を容易なものとすると、離型温度が向
上しレンズのワレが防止できる。As described above, not only the convex lens shape shown in the 1.2th embodiment, but also the plano-concave shape and other shapes are separated from the optical effective diameter by releasing the optical effective diameter. If the growth of the crack into the inside is facilitated, the release temperature is improved, and cracking of the lens can be prevented.
【００３７】[0037]
【発明の効果】本発明の製造方法および製造装置による
と、光学有効径外のプレス面を回転させることで、光学
有効径外を離型させることができる。光学有効径外が離
型すれば、光学有効径内の離型が促進され、全面の離型
する温度が上昇し、ワレが防止される。また、プレス面
の回転による離型を、ガラスの粘度が１０１１（ｄＰａ
・ｓ）以下となる温度範囲で行うと、回転による変形で
応力が発生し有効径外を離型させることができる。ま
た、一度離型したガラスと型とが再び密着することがな
い。同心円状に配置された２つの成形型の熱膨張係数
を、外側よりも内側の方が大きくなるように構成する
と、分割されている第一と第二の成形型との間隙に軟化
したガラスが流入するのを防止でき、さらに熱収縮によ
る間隙での締め付けも防止できる。これらの効果によ
り、安価に高精度な光学素子を製造することができる。According to the manufacturing method and the manufacturing apparatus of the present invention, the outside of the optically effective diameter can be released by rotating the press surface outside the optically effective diameter. If the outside of the optically effective diameter is released, the release within the optically effective diameter is promoted, the temperature at which the entire surface is released is increased, and cracks are prevented. Further, the mold release due to the rotation of the press surface is performed when the viscosity of the glass is 10 11 (dPa).
S) When the temperature is set in the following temperature range, stress is generated by deformation due to rotation, and the mold outside the effective diameter can be released. Also, the glass once released and the mold do not adhere again. If the two molds arranged concentrically are configured such that the coefficient of thermal expansion is larger on the inside than on the outside, the softened glass in the gap between the divided first and second molds Inflow can be prevented, and tightening in the gap due to heat shrinkage can also be prevented. By these effects, a high-precision optical element can be manufactured at low cost.
【図１】第１の実施の形態例における本発明の離型部材
を含む成形装置の型構造例（縦断面図および上面図）で
ある。FIG. 1 is an example of a mold structure (longitudinal sectional view and top view) of a molding device including a release member of the present invention in a first embodiment.
【図２】第１の実施の形態例で行った各成形工程の温度
と時間との関係を示す図である。FIG. 2 is a diagram showing a relationship between temperature and time in each molding step performed in the first embodiment.
【図３】第２の実施の形態例における本発明の離型部材
を含む成形装置の型構造の別例（縦断面図）である。FIG. 3 is another example (longitudinal sectional view) of a mold structure of a molding apparatus including a release member of the present invention in the second embodiment.
【図４】第３の実施の形態例における本発明の離型部材
を含む成形装置（縦断面図）である。FIG. 4 is a molding device (longitudinal sectional view) including a release member of the present invention in a third embodiment.
【図５】両凸レンズ成形用の型構造の概略図（縦断面
図）である。FIG. 5 is a schematic view (longitudinal sectional view) of a mold structure for forming a biconvex lens.
１ 上成形型 ２ 下成形型 ３ プレスレンズ ４ 上離型部材 ５ 下離型部材 ６ 胴型 ７ 抵抗発熱体 ８ 上プレス軸 ９ 下プレス軸 １０ 上円筒部材 １１ 下日筒部材 １２ 上離型部材 １３ 下離型部材 １４ 上成形型 １５ 下成形型 １６ プレスレンズ １７ 上プレス軸 １８ 下プレス軸 １９ 上円筒部材 ２０ 下円筒部材 ２１ 上離型部材 ２２ 下離型部材 ２３ 上成形型 ２４ 下成形型 ２５ プレスレンズ ２６ 余剰ガラス部分 ２７ 上成形型 ２８ 下成形型 ２９ プレスレンズ DESCRIPTION OF SYMBOLS 1 Upper molding die 2 Lower molding die 3 Press lens 4 Upper releasing member 5 Lower releasing member 6 Trunk die 7 Resistance heating element 8 Upper pressing shaft 9 Lower pressing shaft 10 Upper cylindrical member 11 Lower cylindrical member 12 Upper releasing member 13 Lower Release Member 14 Upper Mold 15 Lower Mold 16 Press Lens 17 Upper Press Shaft 18 Lower Press Shaft 19 Upper Cylindrical Member 20 Lower Cylindrical Member 21 Upper Release Member 22 Lower Release Member 23 Upper Mold 24 Lower Mold 25 Press lens 26 Excess glass part 27 Upper mold 28 Lower mold 29 Press lens
Claims (4)
を押圧プレスし冷却することで光学素子を得る成形法に
おいて、その冷却工程中に光軸中心を軸として光学有効
径外の成形型転写面を回転させることを特徴とする光学
素子の製遣方法。In a molding method for obtaining an optical element by pressing and cooling a glass gob in a softened state by a molding die and cooling the same, a transfer surface of the molding die outside an optical effective diameter with an optical axis center as an axis during the cooling step. A method for manufacturing an optical element, comprising rotating the optical element.
スゴブを押圧プレスし光学素子を得る成形法において、
上下成形型の少なくとも一方の成形型を、同心円状に第
一、第二に分割して構成し、前記第一の成形型は少なく
とも光学有効面を形成し、前記第二の成形型は少なくと
も光学有効径外の一部分を形成し、かつ第二の成形型は
第一の成形型の周囲を回転摺動可能としたことを特徴と
する光学素子の製造装置。2. A molding method in which a glass gob in a softened state is pressed and pressed by upper and lower molds to obtain an optical element.
At least one of the upper and lower molds is concentrically divided into first and second parts, the first mold forms at least an optically effective surface, and the second mold has at least an optical surface. An apparatus for manufacturing an optical element, wherein a part outside an effective diameter is formed, and a second mold is rotatable around the first mold.
とした回転を、ガラスの粘度が１０１１（ｄＰａ・ｓ）
以下となる温度範囲で行うことを特徴とする光学素子の
製造方法。3. The method according to claim 1, wherein the rotation of the mold transfer surface around the optical axis center is performed when the viscosity of the glass is 10 11 (dPa · s).
A method for producing an optical element, wherein the method is performed in the following temperature range.
の成形型の熱膨張係数を、上記第一の成形型の熱膨張係
数よりも大きくならないようにしたことを特徴とする光
学素子の製造装置。4. The optical device according to claim 2, wherein a coefficient of thermal expansion of the second mold is not made larger than a coefficient of thermal expansion of the first mold. manufacturing device.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001146478A JP2002338272A (en) | 2001-05-16 | 2001-05-16 | Manufacturing aperture and manufacturing method for optical element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001146478A JP2002338272A (en) | 2001-05-16 | 2001-05-16 | Manufacturing aperture and manufacturing method for optical element |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2002338272A true JP2002338272A (en) | 2002-11-27 |
Family
ID=18992128
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001146478A Withdrawn JP2002338272A (en) | 2001-05-16 | 2001-05-16 | Manufacturing aperture and manufacturing method for optical element |
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| Country | Link |
|---|---|
| JP (1) | JP2002338272A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010195683A (en) * | 2010-05-31 | 2010-09-09 | Hoya Corp | Method for producing optical element |
-
2001
- 2001-05-16 JP JP2001146478A patent/JP2002338272A/en not_active Withdrawn
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010195683A (en) * | 2010-05-31 | 2010-09-09 | Hoya Corp | Method for producing optical element |
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