JPH0432007B2 - - Google Patents
Info
- Publication number
- JPH0432007B2 JPH0432007B2 JP60232396A JP23239685A JPH0432007B2 JP H0432007 B2 JPH0432007 B2 JP H0432007B2 JP 60232396 A JP60232396 A JP 60232396A JP 23239685 A JP23239685 A JP 23239685A JP H0432007 B2 JPH0432007 B2 JP H0432007B2
- Authority
- JP
- Japan
- Prior art keywords
- molding
- temperature
- mold
- glass
- glass material
- 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.)
- Expired - Lifetime
Links
- 238000000465 moulding Methods 0.000 claims description 73
- 239000011521 glass Substances 0.000 claims description 62
- 238000000034 method Methods 0.000 claims description 14
- 230000003287 optical effect Effects 0.000 claims description 10
- 230000009477 glass transition Effects 0.000 claims description 6
- 238000003825 pressing Methods 0.000 claims description 5
- 239000000463 material Substances 0.000 description 43
- 238000010438 heat treatment Methods 0.000 description 13
- 230000000694 effects Effects 0.000 description 5
- 239000005304 optical glass Substances 0.000 description 4
- 230000004927 fusion Effects 0.000 description 3
- 239000007789 gas Substances 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 238000004904 shortening Methods 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 1
- 206010010904 Convulsion Diseases 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 230000001133 acceleration Effects 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 230000005499 meniscus Effects 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000008188 pellet Substances 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 238000012805 post-processing Methods 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 238000010583 slow cooling Methods 0.000 description 1
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
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Devices For Post-Treatments, Processing, Supply, Discharge, And Other Processes (AREA)
Description
【発明の詳細な説明】
［産業上の利用分野］
この発明は、レンズ、プリズム、フイルタ等の
光学素子を研磨等の後加工することなく、ガラス
素材を加熱、軟化させ、所望の形状に対応した一
組の金型によりプレス成形する光学素子の成形方
法に関する。[Detailed Description of the Invention] [Industrial Application Field] This invention heats and softens glass materials to form optical elements such as lenses, prisms, and filters into desired shapes without post-processing such as polishing. The present invention relates to a method for press-molding an optical element using a set of molds.
［従来の技術］
従来、上記光学素子の成形方法としては、例え
ば特公昭56−378号公報、特開昭58−84134号公報
または特開昭60−118639号公報等に開示されるも
のが知られている。これら従来の成形方法は、そ
の成形条件として加熱軟化させたガラス素材の温
度または粘度範囲、金型の温度範囲、プレスの圧
力範囲、プレス保持の時間範囲を制御していた。[Prior Art] Conventionally, as methods for molding the above-mentioned optical elements, methods disclosed in, for example, Japanese Patent Publication No. 56-378, Japanese Patent Application Laid-Open No. 58-84134, or Japanese Patent Application Laid-open No. 118639-1980 are known. It is being In these conventional molding methods, the temperature or viscosity range of the heated and softened glass material, the temperature range of the mold, the pressure range of the press, and the time range of press holding are controlled as the molding conditions.
［発明が解決しようとする問題点］
しかし、上記従来の成形方法のように、ガラス
素材の温度（粘度）、金型温度、プレスの圧力・
時間だけの制御では、成形レンズの肉厚、面精度
等の再現性が悪かつた。また一方、上記成形条件
を面精度が良好となるように設定すると、軟化ガ
ラスと金型とが融着し易くなり、金型の寿命が短
くなつてしまつた。この発明は、このような問題
点に着目してなされたもので、安定で再現性が高
く、高精度な光学素子を得ることができる成形方
法を提供することを目的とする。[Problems to be solved by the invention] However, as in the conventional molding method described above, the temperature (viscosity) of the glass material, mold temperature, press pressure,
When controlling only by time, the reproducibility of molded lens thickness, surface precision, etc. was poor. On the other hand, when the above-mentioned molding conditions are set so that the surface accuracy is good, the softened glass and the mold tend to fuse together, shortening the life of the mold. The present invention was made in view of these problems, and an object of the present invention is to provide a molding method that is stable, has high reproducibility, and can obtain a highly accurate optical element.
［問題点を解決するための手段及び作用］
本発明者等は、従来の問題が今まで制御してい
なかつた成形条件に起因するものと考え、種々検
討した結果、プレススピードを制御することによ
り問題点が解決されることを見い出した。すなわ
ち、本発明は、軟化ガラスをプレス成形する光学
素子の成形方法において、軟化ガラスの温度をガ
ラス転移温度以上にするとともに、プレスに用い
る金型の温度を前記ガラス転移点温度より低く
し、プレススピードを10mm／sec以上としたもの
である。ここに、プレススピードとは、金型がガ
ラス素材に接触して減速される直前の金型のスピ
ード、つまりガラス素材に接触する直前の金型ス
ピードをいう。[Means and effects for solving the problems] The present inventors believed that the conventional problems were caused by molding conditions that had not been controlled until now, and as a result of various studies, the present inventors solved the problem by controlling the press speed. I found that the problem was solved. That is, the present invention provides a method for forming an optical element by press-molding softened glass, in which the temperature of the softened glass is set to be equal to or higher than the glass transition temperature, and the temperature of the mold used for pressing is lower than the glass transition temperature. The speed is 10 mm/sec or more. Here, the press speed refers to the speed of the mold immediately before the mold contacts the glass material and is decelerated, that is, the mold speed immediately before the mold contacts the glass material.
プレススピードが、10mm／sec未満であると、
ガラス素材が十分に変形せず、所定のレンズ形状
を得ることができない。また、プレススピードが
極度に高速になるとガラス素材の変形がそのスピ
ードに追従できなくなつて、割れや焼付きが生じ
てしまうが、100mm／sec以下では満足な成形が得
られ、250mm／secまでは、ガラスの温度（粘度）、
金型温度、プレスの圧力・時間等の他の成形条件
を適宜選択すれば良好な成形を行うことができ
る。 When the press speed is less than 10mm/sec,
The glass material is not sufficiently deformed and a predetermined lens shape cannot be obtained. Additionally, if the press speed becomes extremely high, the deformation of the glass material will not be able to follow that speed, resulting in cracks and seizures, but satisfactory forming can be obtained below 100 mm/sec, and up to 250 mm/sec. is the temperature (viscosity) of the glass,
Good molding can be achieved by appropriately selecting other molding conditions such as mold temperature, press pressure and time.
第１図は、本発明の光学素子の成形方法におい
て使用する成形装置の一例を示すものである。第
１図に示すように、高温による酸化防止を考慮し
た石英ガラス管１の両端は、上板２および下板３
で閉塞され、成形室４が形成されている。また、
上板２と下板３とは、図示省略の部材で結合され
ており、相互間の距離および位置が変化しないよ
うに固定されている。されに、成形室４には、ガ
ス供給装置５が接続されており、成形室４内は、
酸化防止のために例えば窒素ガス等の不活性ガス
または還元性ガスが供給されて非酸化性雰囲気と
なつている。 FIG. 1 shows an example of a molding apparatus used in the optical element molding method of the present invention. As shown in FIG. 1, both ends of the quartz glass tube 1 are connected to an upper plate 2 and a lower plate 3 in order to prevent oxidation caused by high temperatures.
A molding chamber 4 is formed. Also,
The upper plate 2 and the lower plate 3 are connected by a member not shown, and are fixed so that the distance and position between them do not change. In addition, a gas supply device 5 is connected to the molding chamber 4, and the inside of the molding chamber 4 is
In order to prevent oxidation, an inert gas such as nitrogen gas or a reducing gas is supplied to create a non-oxidizing atmosphere.
成形室４内では、プレス圧力を測定するロード
セル６を介して上板２の内面に上型７が固設され
ている。また、成形室４内には、上型７に同軸的
に対向する下型８が下板３を介して導入されてい
る。下型８は、加圧およびスピード制御装置９に
より駆動制御されるプレス駆動軸１０に一体的に
設けられており、軸方向に移動可能で、上型７に
接近離反自在となつている。また、プレス駆動軸
１０には、電磁マイクロのプローブヘツド１１が
取付けられており、その移動量を測定できるよう
になつている。上型７と下型８とは、温度コント
ローラにより所定の温度に設定できる加熱装置
（図示省略）を備えている。 In the molding chamber 4, an upper mold 7 is fixedly installed on the inner surface of the upper plate 2 via a load cell 6 that measures press pressure. Furthermore, a lower mold 8 coaxially opposed to the upper mold 7 is introduced into the molding chamber 4 via the lower plate 3 . The lower mold 8 is integrally provided with a press drive shaft 10 that is driven and controlled by a pressure and speed control device 9, and is movable in the axial direction so that it can freely approach and leave the upper mold 7. Further, an electromagnetic micro probe head 11 is attached to the press drive shaft 10, so that the amount of movement thereof can be measured. The upper mold 7 and the lower mold 8 are equipped with a heating device (not shown) that can be set to a predetermined temperature by a temperature controller.
一方、成形室４には、ガラス素材１２を加熱す
る加熱炉１３が連通接続されている。加熱炉１３
内には、ガラス素材１２を保持する保持台１４が
水平方向に移動自在に設けられており、保持台１
４に載置されたガラス素材１２は、上型７と下型
８との間に搬送されるものである。 On the other hand, a heating furnace 13 for heating the glass material 12 is connected to the molding chamber 4 in communication. Heating furnace 13
Inside, a holding stand 14 for holding the glass material 12 is provided so as to be movable in the horizontal direction.
The glass material 12 placed on the mold 4 is conveyed between the upper mold 7 and the lower mold 8.
上記構成の成形装置によるレンズの成形は、ま
ず、ガラス素材１２を保持台１４上に載置し、図
示を省略した温度コントローラで所定の温度に設
定した加熱炉１３によりガラス素材１２を加熱す
る。その後、保持台１４を移動してガラス素材１
２を上型７と下型８との間に搬送し、下型８を上
動させて、上型７と下型８とでガラス素材１２を
加圧保持して行う。成形後は、下型８を下動させ
て離型し、徐冷炉（図示省略）を経て成形レンズ
を取り出す。なお、離型は、例えば上型７および
下型８の外周にて上下動自在の筒状の離型部材を
設け、この離型部材により離型を行うものであ
る。また、プレス駆動軸１０の駆動において、空
気圧や油圧によりシリンダを駆動するだけで圧力
とスピードとを別個に制御できない機構の装置で
は、プレスによる可動部分（シリンダ、下型等）
の重量によつて加速、減速の特性が異なるため、
この重量も考慮する必要がある。サーボモータ等
を使用した装置では、圧力（トルク）とスピード
とを別個に制御できるので、成形に適している。 To mold a lens using the molding apparatus configured as described above, first, the glass material 12 is placed on the holding table 14, and the glass material 12 is heated by the heating furnace 13, which is set to a predetermined temperature using a temperature controller (not shown). After that, the holding table 14 is moved and the glass material 1 is
2 is conveyed between an upper mold 7 and a lower mold 8, the lower mold 8 is moved upward, and the glass material 12 is held under pressure between the upper mold 7 and the lower mold 8. After molding, the lower mold 8 is moved downward to release the mold, and the molded lens is taken out through a slow cooling furnace (not shown). Note that, for example, a cylindrical mold release member that is vertically movable is provided on the outer periphery of the upper mold 7 and the lower mold 8, and the mold release is performed by this mold release member. In addition, when driving the press drive shaft 10, in a device whose mechanism is such that the cylinder is only driven by air pressure or oil pressure and the pressure and speed cannot be controlled separately, the movable parts (cylinder, lower die, etc.) by the press
Since the acceleration and deceleration characteristics differ depending on the weight of the
This weight also needs to be taken into consideration. A device using a servo motor or the like is suitable for molding because pressure (torque) and speed can be controlled separately.
以下、上記構成の成形装置を用いて行つた実験
結果により、成形におけるプレススピードの影響
について説明する。 The effect of press speed on molding will be explained below based on the results of experiments conducted using the molding apparatus configured as described above.
第１図に示す装置により、重フリント系光学ガ
ラスSF１１からなる径６mm、厚さ２mmのガラス
素材をR1＝R2＝∞の金型で、ガラス素材加熱温
度630℃、金型温度470℃、プレス圧力100Kgｆ／
cm2の成形条件で成形した。そこで、成形中のレン
ズ肉厚の変化を電磁マイクロを用いて測定した結
果を第２図に示す。第２図は、横軸に成形時間、
縦軸に変形量をとつたもので、実線２１で示すよ
うに、ガラス素材をレンズに成形する場合、その
肉厚はプレス成形開始から約0.5秒で決定するこ
とが判明した。 Using the apparatus shown in Figure 1, a glass material made of heavy flint optical glass SF11 with a diameter of 6 mm and a thickness of 2 mm is heated in a mold with R 1 = R 2 = ∞ at a glass material heating temperature of 630°C and a mold temperature of 470°C. , press pressure 100Kgf/
It was molded under molding conditions of cm2 . FIG. 2 shows the results of measuring changes in lens thickness during molding using an electromagnetic micrometer. In Figure 2, the horizontal axis shows the molding time,
The amount of deformation is plotted on the vertical axis, and as shown by the solid line 21, it has been found that when molding a glass material into a lens, the thickness is determined in about 0.5 seconds from the start of press molding.
また、上記成形において、成形中のガラス素材
の温度変化を熱電対を用いて測定した結果を第３
図に示す。第３図は、横軸に成形時間、縦軸に温
度をとつたもので、実線２２で示すように、ガラ
スの流動性の高い状態はプレス成形開始から１秒
しか保持しないことが判明した。 In addition, in the above molding, we measured the temperature change of the glass material during molding using a thermocouple.
As shown in the figure. In FIG. 3, the horizontal axis shows the molding time and the vertical axis shows the temperature. As shown by the solid line 22, it was found that the highly fluid state of the glass was maintained for only 1 second from the start of press molding.
さらに、第４図は、横軸にガラス温度、縦軸に
ガラス粘度をとつたもので、実線２３で示すよう
に、ガラス粘度は温度に対して対数的に変化して
いる。第３図および第４図における実線２２およ
び実線２３の示す特性は、レンズの肉厚がプレス
成形開始後約0.5秒で決定するという第２図の結
果を裏づけている。従つて、プレス成形開始から
0.5秒間の加圧力を制御すればレンズ肉厚を高精
度で制御できることが判つた。 Furthermore, in FIG. 4, the horizontal axis is the glass temperature and the vertical axis is the glass viscosity, and as shown by the solid line 23, the glass viscosity changes logarithmically with respect to the temperature. The characteristics shown by the solid lines 22 and 23 in FIGS. 3 and 4 support the result shown in FIG. 2 that the lens thickness is determined approximately 0.5 seconds after the start of press molding. Therefore, from the start of press forming
It was found that the lens thickness could be controlled with high precision by controlling the pressing force for 0.5 seconds.
そこで、前記成形において、成形中のガラス素
材に加わる圧力の変化をロードセルを用いて測定
した。その結果を第５図に示す。第５図は、横軸
に成形時間、縦軸に成形圧力をとつたもので、実
線２４で示すように、設定した圧力に到達するの
はプレス成形開始から約0.5秒後であり、設定圧
力効果は0.5秒以降に顕著となることが判明した。
すなわち、従来のように、成形条件としてプレス
圧力等だけを制御するのでは、レンズ肉厚を決定
するのに最も重要なプレス成形開始後の0.5秒間
を全く制御できていないのである。そして、プレ
ス成形開始後の0.5秒間は、プレスの設定圧力で
なく、プレススピードが大きく影響を及ぼし、プ
レススピードを制御することでレンズ肉厚の再現
性を向上させることができるものである。 Therefore, in the above molding, changes in the pressure applied to the glass material during molding were measured using a load cell. The results are shown in FIG. In Figure 5, the horizontal axis shows the molding time and the vertical axis shows the molding pressure.As shown by the solid line 24, the set pressure is reached approximately 0.5 seconds after the start of press molding, and the set pressure It was found that the effect becomes noticeable after 0.5 seconds.
In other words, if only the press pressure etc. are controlled as the molding conditions as in the past, it is not possible to control the 0.5 seconds after the start of press molding, which is the most important period in determining the lens thickness. For 0.5 seconds after the start of press molding, the press speed rather than the set pressure of the press has a large effect, and by controlling the press speed, the reproducibility of the lens thickness can be improved.
プレススピードを10mm／sec以上とすることに
より、ガラスの粘度が低くて流動性の高い状態で
大きな変形をさせることが可能となり、ガラス素
材はプレス直後に金型形状と等しくなつて、金型
面から受ける圧力分布が均一になる。このため、
金型面の転写性が向上して従来より良好なレンズ
面精度を得ることができた。また、同じ面精度を
得るについて、従来よりもガラス素材の加熱温
度、金型温度、成形圧力等を低くした条件で十分
に行うことができ、金型温度をガラス転移点温度
より低く設定でき、金型とガラス素材（レンズ）
との融着も防止される。 By setting the pressing speed to 10 mm/sec or more, it is possible to greatly deform the glass with low viscosity and high fluidity, and the glass material becomes equal to the mold shape immediately after pressing, and the mold surface The pressure distribution received from the machine becomes uniform. For this reason,
The transferability of the mold surface was improved and better lens surface accuracy than before was achieved. In addition, to obtain the same surface accuracy, it is possible to sufficiently lower the heating temperature of the glass material, mold temperature, molding pressure, etc. than in the past, and the mold temperature can be set lower than the glass transition temperature. Mold and glass material (lens)
It also prevents fusion with.
［実施例］
第１実施例
第１図に示す成形装置を用いて重フリント系光
学ガラスSF１１からなるガラス素材をレンズ成
形した。ガラス素材は、径８mm、厚さ２mmの円筒
状ペレツトの上下面を平面研磨したものを用い、
最終レンズ形状は、径６mm、中心肉厚1.5mmのメ
ニスカス形状である。先ず、ペレツト状のガラス
素材１２を保持台１４上に載置し、加熱炉１３内
でガラス転移温度以上となるように加熱したガラ
ス素材１２の粘度を108ポアズとした。次に、ガ
ラス素材１２を上型７と下型８との間に位置する
ように搬送した。そして、ガラス素材１２の温度
より低い温度（ガラス粘度1014.5〜103.4に対応す
る温度）に加熱した上型７と下型８とで成形を行
つた。その際、下型８のプレススピードは、60±
５mm／secに制御してあり、成形圧力は80Kgｆ／
cm2であつた。[Example] First Example A glass material made of heavy flint optical glass SF11 was molded into a lens using the molding apparatus shown in FIG. The glass material used was a cylindrical pellet with a diameter of 8 mm and a thickness of 2 mm, with the top and bottom surfaces polished.
The final lens shape is a meniscus shape with a diameter of 6 mm and a center wall thickness of 1.5 mm. First, a pellet-shaped glass material 12 was placed on a holding table 14, and heated in a heating furnace 13 to a temperature higher than the glass transition temperature.The viscosity of the glass material 12 was set to 108 poise. Next, the glass material 12 was transported so as to be located between the upper mold 7 and the lower mold 8. Then, molding was performed using the upper mold 7 and the lower mold 8 heated to a temperature lower than the temperature of the glass material 12 (temperature corresponding to a glass viscosity of 10 14.5 to 10 3.4 ). At that time, the press speed of the lower die 8 is 60±
It is controlled at 5mm/sec, and the molding pressure is 80Kgf/
It was warm in cm2 .
第１実施例により得たもののレンズ肉厚のバラ
ツキを第６図に、面精度のバラツキを第７図に示
す。第６図は、横軸にレンズ肉厚、縦軸に個数を
とつたもので、第７図は、横軸に面精度（ニユー
トン）、縦軸に個数をとつたものである。第６図
および第７図から判るように、第１実施例によれ
ば、レンズ肉厚、面精度のバラツキはほとんどな
く、レンズ肉厚の公差の激しい製品に対してもほ
ぼ100％の歩留りで供給することができた。 FIG. 6 shows the variation in lens thickness obtained in the first embodiment, and FIG. 7 shows the variation in surface precision. 6 shows the lens thickness on the horizontal axis and the number of lenses on the vertical axis, and FIG. 7 shows the surface precision (Newton) on the horizontal axis and the number of lenses on the vertical axis. As can be seen from FIGS. 6 and 7, according to the first embodiment, there is almost no variation in lens thickness and surface accuracy, and the yield is almost 100% even for products with severe tolerances in lens thickness. were able to supply it.
これに対し、従来の如くプレススピードを制御
せずに、他の成形条件を第１実施例と同一にして
行つた場合のレンズ肉厚および面精度（ニユート
ン）のバラツキをそれぞれ第８図および第９図に
示す。第８図は、横軸にレンズ肉厚、縦軸に個数
をとつたもので、第９図は、横軸に面精度、縦軸
に個数をとつたものである。第８図および第９図
から判るようにレンズ肉厚および面精度のバラツ
キは、第１実施例に比較して著しかつた。 On the other hand, when the press speed is not controlled as in the conventional case and other molding conditions are the same as in the first embodiment, the variations in lens thickness and surface precision (Newton) are shown in Figures 8 and 8, respectively. Shown in Figure 9. 8 shows the lens thickness on the horizontal axis and the number of lenses on the vertical axis, and FIG. 9 shows the surface accuracy on the horizontal axis and the number of lenses on the vertical axis. As can be seen from FIGS. 8 and 9, the variations in lens thickness and surface precision were more significant than in the first embodiment.
第２実施例
第１図に示す成形装置を用いてクラウン系光学
ガラスＫ２からなるガラス素材をレンズ成形し
た。ガラス素材は、径８mm、中心肉厚1.4mm、R1
＝50mm、R2＝30mmの両凹レンズである。また、
所望のレンズは、面精度が目標球面半径に対して
ニユートンリング２本、イレギユラリテイ同0.3
本、アス同0.2本以内となるようにし、プレスス
ピードは、20mm／secと80mm／secの場合との二通
りに設定した。Second Example A glass material made of crown type optical glass K2 was molded into a lens using the molding apparatus shown in FIG. The glass material is 8mm in diameter, 1.4mm in center thickness, and R 1.
It is a biconcave lens with = 50mm and R 2 = 30mm. Also,
The desired lens has a surface accuracy of 2 Newton rings with respect to the target spherical radius and an irregularity of 0.3.
The press speed was set to be within 0.2 of the same between the main and the aperture lines, and the press speed was set in two ways: 20 mm/sec and 80 mm/sec.
プレススピードが20mm／secの場合には、上記
面精度を得るのに、ガラス素材加熱温度720℃
（約106.2ポアズ）、金型温度520℃（約1013.1ポア
ズ）、成形圧力120Kgｆ／cm2、成形時間30秒を要し
た。これに対し、プレススピードが80mm／secの
場合には、上記面精度を得るのに、ガラス素材加
熱温度700℃（約106.8ポアズ）、金型温度500℃
（約1013.8ポアズ）、成形圧力80Kgｆ／cm2、成形時
間15秒であつた。 When the press speed is 20mm/sec, the glass material heating temperature is 720℃ to obtain the above surface accuracy.
(approximately 10 6.2 poise), mold temperature 520° C. (approximately 10 13.1 poise), molding pressure 120 Kgf/cm 2 , and molding time 30 seconds. On the other hand, when the press speed is 80 mm/sec, the glass material heating temperature is 700℃ (approximately 10 6.8 poise) and the mold temperature is 500℃ to obtain the above surface accuracy.
(approximately 1013.8 poise), molding pressure was 80 Kgf/cm 2 , and molding time was 15 seconds.
すなわち、プレススピードを速くすることによ
り、低温、低圧、短時間で成形することが可能と
なることを示している。これは、成形プロセスの
サイクルタイムの短縮、金型材料の選択、ヒー
タ・熱電対等の長寿命化、金型とガラスとの融着
防止等に効果があり、成形の安定化に大きく寄与
するものである。 In other words, it is shown that by increasing the press speed, it becomes possible to perform molding at low temperature, low pressure, and in a short time. This is effective in shortening the cycle time of the molding process, selecting mold materials, extending the life of heaters and thermocouples, preventing fusion between the mold and glass, and greatly contributing to the stability of molding. It is.
第３実施例
第１図に示す成形装置を用いて重フリント系光
学ガラスSF２からなるガラス素材をレンズ成形
した。ガラス素材は、径18mm、厚さ3.5mmで、最
終レンズ形状は、径16mm、中心肉厚1.9mm、R1＝
11.8mm、R2＝50.5mmの両凹レンズである。成形方
法は第１実施例と同様であり、ガラス素材の温度
600℃（約106ポアズ）、金型温度420℃（約
1013.7）、成形圧力90Kgｆ／cm2、プレススピード50
mm／secとした。Third Example A glass material made of heavy flint optical glass SF2 was molded into a lens using the molding apparatus shown in FIG. The glass material is 18 mm in diameter and 3.5 mm thick, and the final lens shape is 16 mm in diameter, 1.9 mm in center thickness, and R 1 =
It is a biconcave lens of 11.8 mm and R 2 = 50.5 mm. The molding method is the same as in the first example, and the temperature of the glass material is
600℃ (approx. 10 6 poise), mold temperature 420℃ (approx.
10 13.7 ), molding pressure 90Kgf/cm 2 , press speed 50
mm/sec.
その結果、十分満足できる面精度を有したレン
ズを得ることができた。 As a result, a lens with sufficiently satisfactory surface accuracy could be obtained.
これに対し、プレススピードを７mm／secとし、
他の成形条件を上記第３実施例と同様にして成形
を行つたところ、ガラス素材は十分に変形せず、
所定のレンズ形状が得られなかつた。そこで、ガ
ラス素材加熱温度や金型温度を高くして、プレス
スピード７mm／secで成形を行つたが、金型とガ
ラス素材との融着が生じてしまい、成形不能とな
つてしまつた。 On the other hand, when the press speed was set to 7 mm/sec,
When molding was carried out under the same molding conditions as in the third example, the glass material did not deform sufficiently.
A predetermined lens shape could not be obtained. Therefore, the heating temperature of the glass material and the mold temperature were increased, and molding was performed at a press speed of 7 mm/sec, but the mold and the glass material were fused together, making molding impossible.
［発明の効果］
以上のように、本発明の光学素子の成形方法に
よれば、従来では制御の対象としていなかつたプ
レススピードをも制御することとしたので、成形
レンズの中肉、金型転写性のバラツキを著しく減
少することができ、しかも金型温度をガラス転移
点温度より低くしたので、金型とガラスとの融着
を防止でき、ガラス素材加熱温度および金型温度
ともに低温でかつ成形圧力を低く、短時間で安定
した成形を行うことができる。[Effects of the Invention] As described above, according to the optical element molding method of the present invention, the press speed, which was not controlled in the past, is also controlled, so that the inner thickness of the molded lens and the mold Variations in transferability can be significantly reduced, and since the mold temperature is lower than the glass transition temperature, fusion between the mold and glass can be prevented, and both the glass material heating temperature and the mold temperature can be kept at low temperatures. Stable molding can be performed in a short time with low molding pressure.
第１図は本発明の光学素子の成形方法において
使用する成形装置の一例を示す概略縦断正面図、
第２図は成形中のレンズ肉厚の変化を表わすグラ
フ、第３図は成形中のガラス素材の温度変化を表
わすグラフ、第４図はガラス温度とガラス粘度と
の関係を示すグラフ、第５図は成形中のガラス素
材に加わる圧力の変化を表わすグラフ、第６図お
よび第７図はそれぞれ第１実施例におけるレンズ
肉厚および面精度のバラツキを表わすグラフ、第
８図および第９図はそれぞれプレススピードを制
御しない場合におけるレンズ肉厚および面精度の
バラツキを表わすグラフである。
４……成形室、７……上型、８……下型、９…
…加圧およびスピード制御装置、１２……ガラス
素材、１３……加熱炉。
FIG. 1 is a schematic longitudinal sectional front view showing an example of a molding apparatus used in the optical element molding method of the present invention;
Figure 2 is a graph showing the change in lens thickness during molding, Figure 3 is a graph showing the temperature change of the glass material during molding, Figure 4 is a graph showing the relationship between glass temperature and glass viscosity, and Figure 5 is a graph showing the relationship between glass temperature and glass viscosity. The figure is a graph showing changes in the pressure applied to the glass material during molding. Figures 6 and 7 are graphs showing variations in lens thickness and surface accuracy in the first example, respectively. Figures 8 and 9 are graphs showing variations in the lens thickness and surface accuracy in the first example. 3 is a graph showing variations in lens thickness and surface precision when the press speed is not controlled. 4...Molding chamber, 7...Upper mold, 8...Lower mold, 9...
...Pressure and speed control device, 12...Glass material, 13...Heating furnace.
Claims (1)
方法において、軟化ガラスの温度を108〜106ポア
ズ相当の温度にするとともに、プレスに用いる型
の温度を前記軟化ガラスのガラス転移点温度未満
で、ガラス粘度1014.5ポアズ相当の温度以上の範
囲に設定し、プレス速度を10mm／秒〜250mm／秒
とすることを特徴とする光学素子の成形方法。1. In a method for forming an optical element by press-molding softened glass, the temperature of the softened glass is set to a temperature equivalent to 10 8 to 10 6 poise, and the temperature of the mold used for pressing is set below the glass transition point temperature of the softened glass, A method for molding an optical element, characterized in that the temperature is set at a temperature equal to or higher than a glass viscosity of 10 to 14.5 poise, and the press speed is set in a range of 10 mm/sec to 250 mm/sec.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23239685A JPS6291431A (en) | 1985-10-18 | 1985-10-18 | Forming of optical element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23239685A JPS6291431A (en) | 1985-10-18 | 1985-10-18 | Forming of optical element |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6291431A JPS6291431A (en) | 1987-04-25 |
| JPH0432007B2 true JPH0432007B2 (en) | 1992-05-28 |
Family
ID=16938581
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23239685A Granted JPS6291431A (en) | 1985-10-18 | 1985-10-18 | Forming of optical element |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6291431A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02267127A (en) * | 1989-04-06 | 1990-10-31 | Olympus Optical Co Ltd | Method for forming optical element and device therefor |
| JP4489507B2 (en) * | 2004-06-16 | 2010-06-23 | 東芝機械株式会社 | Glass forming equipment |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59203732A (en) * | 1983-05-02 | 1984-11-17 | Olympus Optical Co Ltd | Process and device for forming lens |
-
1985
- 1985-10-18 JP JP23239685A patent/JPS6291431A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59203732A (en) * | 1983-05-02 | 1984-11-17 | Olympus Optical Co Ltd | Process and device for forming lens |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6291431A (en) | 1987-04-25 |
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