JPH0753587B2 - Glass lens molding method - Google Patents
Glass lens molding methodInfo
- Publication number
- JPH0753587B2 JPH0753587B2 JP62236541A JP23654187A JPH0753587B2 JP H0753587 B2 JPH0753587 B2 JP H0753587B2 JP 62236541 A JP62236541 A JP 62236541A JP 23654187 A JP23654187 A JP 23654187A JP H0753587 B2 JPH0753587 B2 JP H0753587B2
- Authority
- JP
- Japan
- Prior art keywords
- mold
- thermal expansion
- coefficient
- glass
- lens
- 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 - Fee Related
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
- C03B2215/02—Press-mould materials
- C03B2215/03—Press-mould materials defined by material properties or parameters, e.g. relative CTE of mould parts
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B2215/00—Press-moulding glass
- C03B2215/40—Product characteristics
- C03B2215/46—Lenses, e.g. bi-convex
- C03B2215/48—Convex-concave
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B2215/00—Press-moulding glass
- C03B2215/72—Barrel presses or equivalent, e.g. of the ring mould type
Description
【発明の詳細な説明】 産業上の利用分野 本発明は、光学機器に使用されるガラスレンズを精密ガ
ラス成形法により形成するガラスレンズの成形方法に関
するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass lens molding method for forming a glass lens used in optical equipment by a precision glass molding method.
従来の技術 近年光学レンズを研磨工程なしの一発形成により形成す
る試みが多くなされている。ガラス素材を溶融状態から
型に渡し込み加工成形する方法が最も効率的であるが、
冷却時のガラスの収縮を制御することが難しく精密なガ
ラス成形には適しない。従って、ガラス素材を一定の形
状に予備加工してこれを型の間に供給し、加熱後、加圧
成形するのが一般的な方法である。（例えば、特開昭58
−84134号公報） 発明が解決しようとする問題点 上記の様な成形方法における金型材料としては炭化タン
グステンを主成分とする超硬合金、炭化チタン、アルミ
ナ、窒化チタン、炭化クロムをそれぞれ主成分とするサ
ーメット材等が用いられている。（例えば特開昭61−13
6928号公報）これらの金型材料の熱膨張係数は40〜80X1
0-7/℃前後であり、ガラス素材の熱膨張係数の90X10-7/
℃（SF系硝材）に対し小さい。そのためメニスカスレン
ズ或いは凹レンズを成形する場合、第２図に示すように
成形完了後の冷却時において、ガラス素材の熱膨張係数
に対し金系の熱膨張係数が小さいことから、金型の収縮
量よりも成形レンズの収縮量の方が大きくなる。従っ
て、第２図の成形レンズ３と上下型１、２との熱収縮関
係は、下型２と成形レンズ３の凸面においては成形レン
ズ３の熱収縮に対し下型２はなんら阻害要因とならない
が、上型１と成形レンズ３の凹面においては熱収縮量の
差により上型１よりも成形レンズ３の曲率半径が小さく
なる。このため上型１が圧力Ｐの力でもって成形レンズ
３の収縮を妨げることになり、成形レンズ３に歪みが生
じ金型の面形状が精密に転写できないという問題を有し
ていた。2. Description of the Related Art Recently, many attempts have been made to form an optical lens by one-shot formation without a polishing step. The most efficient method is to pass the glass material from the molten state to the mold and process it.
It is difficult to control the shrinkage of the glass during cooling and it is not suitable for precise glass forming. Therefore, it is a general method that a glass material is preliminarily processed into a predetermined shape, the glass material is supplied between molds, heated, and then pressure-molded. (For example, JP-A-58
-84134 gazette) Problem to be solved by the invention As a mold material in the above-mentioned molding method, cemented carbide containing tungsten carbide as a main component, titanium carbide, alumina, titanium nitride, and chromium carbide are main components, respectively. The cermet material etc. is used. (For example, Japanese Patent Laid-Open No. 61-13
6928) The coefficient of thermal expansion of these mold materials is 40-80X1.
It is around 0 -7 / ℃, 90X10 -7 / of the thermal expansion coefficient of glass material
Small against ℃ (SF glass material). Therefore, when molding a meniscus lens or a concave lens, as shown in Fig. 2, when cooling after molding is completed, the coefficient of thermal expansion of the metal system is smaller than the coefficient of thermal expansion of the glass material. However, the amount of shrinkage of the molded lens is larger. Therefore, regarding the heat shrinkage relationship between the molded lens 3 and the upper and lower molds 1 and 2 in FIG. 2, the lower mold 2 does not become an obstacle to the heat shrinkage of the molded lens 3 on the convex surfaces of the lower mold 2 and the molded lens 3. However, on the concave surfaces of the upper mold 1 and the molded lens 3, the radius of curvature of the molded lens 3 is smaller than that of the upper mold 1 due to the difference in the amount of heat shrinkage. For this reason, the upper mold 1 hinders the contraction of the molded lens 3 by the force of the pressure P, and there is a problem that the molded lens 3 is distorted and the surface shape of the mold cannot be accurately transferred.
問題点を解決するための手段 上記のような問題点を解決するため、本発明は成形レン
ズの凹面に相対する凸金型にはその熱膨張係数がガラス
素材の熱膨張係数に等しいか或いは大きい型材を用い、
凸金型の熱膨張係数≧ガラス素材の熱膨張係数≧凹金型
の熱膨張係数なる関係の金型構成とする手段を講じたも
のである。Means for Solving the Problems In order to solve the above problems, the present invention provides a convex mold facing the concave surface of a molded lens whose coefficient of thermal expansion is equal to or larger than that of the glass material. Using mold material,
A means for forming a mold having a relationship of a coefficient of thermal expansion of a convex mold ≧ a coefficient of thermal expansion of a glass material ≧ a coefficient of thermal expansion of a concave mold is taken.
作用 本発明は前記手段により、上型１の熱収縮が成形レンズ
３の熱収縮と同等もしくは大きくなり、原理的に金型が
成形レンズの冷却時の収縮を妨げる事なく、成形レンズ
が転写された型形状をそのまま維持しつつ収縮すること
を可能とするものである。Action In the present invention, the heat shrinkage of the upper mold 1 becomes equal to or larger than the heat shrinkage of the molded lens 3 by the above means, and in principle, the molded lens is transferred without hindering the shrinkage of the molded lens during cooling. It is possible to shrink while maintaining the mold shape as it is.
実施例 以下本発明の一実施例について、図面を用いて詳細に説
明する。Embodiment One embodiment of the present invention will be described in detail below with reference to the drawings.
第１図は本発明による一実施例を示す。FIG. 1 shows an embodiment according to the present invention.
１は上型で熱膨張係数が110X10-7/℃のステンレス鋼、
２は下型で熱膨張係数が50X10-7/℃の炭化タングステン
を主成分とする超硬金型、３は胴型で下型と同様の超硬
合金を用いた。４はガラス素材で熱膨張係数が97X10-7/
℃のSF−６硝材である。5,6は上限プレスヘッドであり
プレス機構は略す。1 is upper mold, stainless steel with thermal expansion coefficient of 110X10 -7 / ℃,
Reference numeral 2 is a lower die, and a cemented carbide die mainly composed of tungsten carbide having a thermal expansion coefficient of 50 × 10 −7 / ° C. 3 is a barrel die, and the same cemented carbide as the lower die is used. 4 is a glass material and has a thermal expansion coefficient of 97X10 -7 /
It is SF-6 glass material of ℃. 5 and 6 are upper limit press heads, and the press mechanism is omitted.
まず、第１図（ａ）のように金型内にガラス素材４を供
給した後非酸化性雰囲気に保たれた上下プレスヘッド5,
6間に前記金型をセットし、金型共々ガラスの軟化温度
付近まで加熱する。そして加圧成形後、加熱を停止しガ
ラス転位点付近まて加圧冷却する。ガラス転位点以下の
温度で加圧を解除した後、常温まで冷却し金型内から成
形レンズ７を取り出す。First, as shown in FIG. 1 (a), the glass material 4 is supplied into the mold and then the upper and lower press heads 5, which are kept in a non-oxidizing atmosphere,
The mold is set between 6 and both molds are heated to near the softening temperature of the glass. After pressure forming, heating is stopped and pressure cooling is performed to near the glass transition point. After releasing the pressure at a temperature below the glass transition point, the molded lens 7 is taken out from the mold by cooling to room temperature.
以上の成形法により成形したレンズの形状精度を測定し
た所、0.2μｍ（Ｐ−Ｖ値）以下の非常に高い精度の成
形レンズを得ることができた。第１図（ｂ）にその成形
レンズの形状を示す。外径20mm、中心厚1mm、凹面の曲
率半径15mm、凸面の曲率半径150mmである。When the shape accuracy of the lens molded by the above molding method was measured, a molded lens with a very high accuracy of 0.2 μm (P-V value) or less could be obtained. FIG. 1 (b) shows the shape of the molded lens. The outer diameter is 20 mm, the center thickness is 1 mm, the concave radius of curvature is 15 mm, and the convex radius of curvature is 150 mm.
本実施例ではガラスレンズの成形方法について述べた
が、本発明はプラスチックレンズの成形方法においても
適用できることは言うまでもない。Although the glass lens molding method is described in this embodiment, it goes without saying that the present invention can be applied to a plastic lens molding method.
発明の効果 本発明を用いることにより、原理的にいかなるレンズ形
状のものに対しても成形レンズの冷却時における収縮が
金型により妨げられることがなく、自然な熱収縮が行な
われるため、一度求めた最適成形条件を変更することな
く安定した高精度な成形を実現しうるものである。EFFECTS OF THE INVENTION By using the present invention, for any lens shape in principle, the shrinkage during cooling of the molded lens is not hindered by the mold, and natural heat shrinkage is performed. It is possible to realize stable and highly accurate molding without changing the optimum molding conditions.
第１図（ａ）は本発明による成形直前の断面図、第１図
（ｂ）は本発明により成形されたレンズの断面図、第２
図は従来の成形法による成形完了後の冷却時における金
型と成形レンズの熱膨張係数の差による影響の様子を示
す断面図である。 １……上型、２……下型、３……胴型、４……ガラス素
材、5,6……プレスヘッド、７……成形レンズ。FIG. 1 (a) is a sectional view just before molding according to the present invention, and FIG. 1 (b) is a sectional view of a lens molded according to the present invention.
FIG. 1 is a cross-sectional view showing an influence of a difference in thermal expansion coefficient between a mold and a molded lens during cooling after completion of molding by a conventional molding method. 1 ... upper mold, 2 ... lower mold, 3 ... body mold, 4 ... glass material, 5,6 ... press head, 7 ... molded lens.
Claims (2)
膨張係数が、凸金型の熱膨張係数≧ガラスの熱膨張係数
≧凹金型の熱膨張係数の関係にあることを特徴とするガ
ラスレンズの成形方法。1. The coefficient of thermal expansion of a mold with respect to the coefficient of thermal expansion of a glass material has a relationship of a coefficient of thermal expansion of a convex mold ≧ a coefficient of thermal expansion of glass ≧ a coefficient of thermal expansion of a concave mold. Molding method for glass lens.
レス鋼、クロムカーバイド、高ニッケル合金であること
を特徴とする特許請求の範囲第（１）項記載のガラスレ
ンズの成形方法。2. The method of molding a glass lens according to claim 1, wherein the material of the convex mold is maraging steel, stainless steel, chrome carbide, or high nickel alloy.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62236541A JPH0753587B2 (en) | 1987-09-21 | 1987-09-21 | Glass lens molding method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62236541A JPH0753587B2 (en) | 1987-09-21 | 1987-09-21 | Glass lens molding method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6479027A JPS6479027A (en) | 1989-03-24 |
| JPH0753587B2 true JPH0753587B2 (en) | 1995-06-07 |
Family
ID=17002197
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62236541A Expired - Fee Related JPH0753587B2 (en) | 1987-09-21 | 1987-09-21 | Glass lens molding method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0753587B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006206346A (en) * | 2005-01-25 | 2006-08-10 | Nikon Corp | Mold for glass molding and optical element molding device and method using the same |
| JP5600448B2 (en) * | 2010-03-05 | 2014-10-01 | Ｈｏｙａ株式会社 | Optical lens molding die and optical lens manufacturing method using the same |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6345136A (en) * | 1986-08-12 | 1988-02-26 | Olympus Optical Co Ltd | Forming method for optical element |
-
1987
- 1987-09-21 JP JP62236541A patent/JPH0753587B2/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6345136A (en) * | 1986-08-12 | 1988-02-26 | Olympus Optical Co Ltd | Forming method for optical element |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6479027A (en) | 1989-03-24 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |