JPH1036123A - Production of glass gob - Google Patents
Production of glass gobInfo
- Publication number
- JPH1036123A JPH1036123A JP21304896A JP21304896A JPH1036123A JP H1036123 A JPH1036123 A JP H1036123A JP 21304896 A JP21304896 A JP 21304896A JP 21304896 A JP21304896 A JP 21304896A JP H1036123 A JPH1036123 A JP H1036123A
- Authority
- JP
- Japan
- Prior art keywords
- glass
- outlet
- conduit
- diameter
- mold
- 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.)
- Pending
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B7/00—Distributors for the molten glass; Means for taking-off charges of molten glass; Producing the gob, e.g. controlling the gob shape, weight or delivery tact
- C03B7/08—Feeder spouts, e.g. gob feeders
- C03B7/088—Outlets, e.g. orifice rings
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B7/00—Distributors for the molten glass; Means for taking-off charges of molten glass; Producing the gob, e.g. controlling the gob shape, weight or delivery tact
- C03B7/10—Cutting-off or severing the glass flow with the aid of knives or scissors or non-contacting cutting means, e.g. a gas jet; Construction of the blades used
- C03B7/12—Cutting-off or severing a free-hanging glass stream, e.g. by the combination of gravity and surface tension forces
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B7/00—Distributors for the molten glass; Means for taking-off charges of molten glass; Producing the gob, e.g. controlling the gob shape, weight or delivery tact
- C03B7/14—Transferring molten glass or gobs to glass blowing or pressing machines
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Glass Compositions (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、表面欠陥がなく、
かつ、高度な均質性が要求される光学レンズ用プリフォ
−ム材としてのガラスゴブを、溶融ガラスが有する粘性
と表面張力を利用して効率よく、連続的に取得する方法
に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention
Also, the present invention relates to a method for continuously and efficiently obtaining a glass gob as a preform material for an optical lens, which requires a high degree of homogeneity, by utilizing the viscosity and surface tension of molten glass.
【０００２】[0002]
【従来の技術】従来、光学レンズ用プリフォ−ム材を得
る方法としては、ブランクスと称するガラスゴブやプレ
ス品から製造されている。ところが、いずれの場合もガ
ラス表面にシャ−・マ−ク、傷、ひけ等の表面欠陥を発
生し、そのまま光学レンズ用プリフォ−ム材としては使
用できない。その理由は、溶融ガラス流から所定のガラ
スゴブを切断するには、シャ−・ブレ−ドと称する金属
製のハサミによってガラス流を切断するが、この際ガラ
ス切断面にシャ−・マ−ク等の表面欠陥を生じるからで
ある。そこで、このようなシャ−・ブレ−ドを使用する
ことなくガラス流を切断する方法が各種提案されてい
る。2. Description of the Related Art Conventionally, as a method of obtaining a preform material for an optical lens, it is manufactured from a glass gob called a blank or a pressed product. However, in any case, a surface defect such as a sharp mark, a scratch or a sink occurs on the glass surface and cannot be used as it is as a preform material for an optical lens. The reason is that in order to cut a predetermined glass gob from the molten glass stream, the glass stream is cut with metal scissors called a "sharp blade". This causes surface defects. Therefore, various methods have been proposed for cutting the glass flow without using such a shear blade.
【０００３】例えば、特公昭５１−２４５２５号公報に
は導管流出口から流下するガラスを鋳型内部で上下に移
動可能な中型で受け、流出口と鋳込みガラス面との位置
関係を最適に維持するために、鋳型中のガラス量に応じ
て中型のみを徐々に下降させ、所定のガラス量に達した
ら、鋳型全体を急速に下降させてガラス流を切断する方
法が記載されている。この方法によれば、ガラス流の切
断にシャ−・ブレ−ドを使用しないので、表面欠陥のな
いガラスゴブを得ることができる。ところがこの方法で
はガラス流を切断後、再度導管流出口からガラス流が流
出するまでの時間が非常に短いため、この短時間内に次
の鋳型を所定の位置に設置しなければならないという困
難な問題がある。[0003] For example, Japanese Patent Publication No. 51-24525 discloses that a glass flowing down from a conduit outlet is received by a medium mold which can be moved up and down inside a mold, and the positional relationship between the outlet and the cast glass surface is optimally maintained. Describes a method of gradually lowering only the middle mold according to the amount of glass in the mold and, when a predetermined amount of glass is reached, rapidly lowering the entire mold to cut the glass flow. According to this method, a glass gob having no surface defects can be obtained because no sharp blade is used for cutting the glass flow. However, in this method, the time required for the glass flow to flow again from the conduit outlet after the glass flow is cut is very short, so that it is difficult to set the next mold in a predetermined position within this short time. There's a problem.
【０００４】また、特開昭５３−５０２１８号公報に
は、導管流出口から流下したガラス流を鋳型に鋳込んだ
後、一枚のプレ−トを水平移動させてガラス流を切断
し、次いで次の鋳型を流出口の直下に設置するまでの
間、ガラス流をプレ−ト上で保持し、その後、プレ−ト
をガラス流から外して、次のガラスゴブを成形する方法
が記載されている。しかし、この方法ではプレ−トの介
入によって流出口と鋳型との間の距離が長くなり、装置
の最適化が難しくなったり、またプレ−トの移動時に生
じる伸びたガラスが折れ込みとなって、製品に欠陥を生
じてしまうという問題がある。Japanese Patent Application Laid-Open No. 53-50218 discloses a method in which a glass stream flowing down from a conduit outlet is cast into a mold, and one sheet is moved horizontally to cut the glass stream. A method is described in which the glass flow is held on a plate until the next mold is placed immediately below the outlet, and then the plate is removed from the glass flow to form the next glass gob. . However, in this method, the distance between the outlet and the mold is increased due to the intervention of the plate, which makes it difficult to optimize the apparatus and that the elongated glass generated when the plate is moved is broken. However, there is a problem that a defect occurs in the product.
【０００５】特開昭５５−２７８４９号公報には、これ
らの技術における諸欠点を解消すべく、導管流出口から
連続的に流出するガラスを、上記導管流出口の下部に備
えた制御盤に接触させつつ、制御盤の下方に設けた鋳型
に流し入れ、ガラスが所定の量に達したら鋳型を急速に
下降させてガラス流を切断し、引き続き上記流出口から
流出するガラスをその表面張力を利用して、制御盤の下
面にガラスを所定時間蓄積滞留させることによりガラス
の自由流下を遅延制御するガラスゴブの成形方法が記載
されている。しかし、この方法は装置の構造が複雑であ
り、制御盤の準備あるいは調整に時間と熟練を要すると
いう欠点を有している。例えば、制御盤の取り付け位置
が最適位置から僅かにずれただけで製品に脈理や失透が
発生してしまい、高品質のガラスゴブを歩留りよく製造
することが困難である。Japanese Patent Application Laid-Open No. 55-27849 discloses that in order to eliminate the drawbacks of these techniques, glass continuously flowing out of a conduit outlet is brought into contact with a control panel provided below the conduit outlet. While flowing, the glass is poured into a mold provided below the control panel, and when the glass reaches a predetermined amount, the mold is rapidly lowered to cut the glass flow, and then the glass flowing out from the outlet is used by utilizing its surface tension. In addition, a method of forming a glass gob that delays free flow of glass by accumulating and retaining glass on a lower surface of a control panel for a predetermined time is described. However, this method has the drawback that the structure of the apparatus is complicated, and preparation and adjustment of the control panel require time and skill. For example, if the mounting position of the control panel is slightly deviated from the optimal position, striae and devitrification occur in the product, and it is difficult to manufacture a high-quality glass gob with good yield.
【０００６】[0006]
【発明が解決しようとする課題】本発明は上記従来技術
の欠点を解消する方法、すなわち、シャ−・ブレ−ド、
プレ−トおよび制御盤等の複雑な装置を用いずに、シャ
−・マ−ク、失透、および脈理等の品質欠陥のないガラ
スゴブを製造することを目的とする。SUMMARY OF THE INVENTION The present invention is directed to a method for overcoming the above-mentioned disadvantages of the prior art, namely, the use of a shear blade,
It is an object of the present invention to produce a glass gob free from quality defects such as sharp marks, devitrification, and striae without using complicated devices such as a plate and a control panel.
【０００７】[0007]
【問題を解決するための手段】上記目的を達成するた
め、本発明者は鋭意試験研究の結果、導管流出口の口径
を導管本体よりも大きくすることにより、上記諸問題を
解決するに至った。すなわち、請求項１に記載の発明
は、導管流出口から連続して流出する溶融ガラス流を導
管流出口の下方に設けた鋳型に鋳込んでガラスゴブを製
造する方法において、上記導管流出口の口径を導管本管
よりも大きくすることを特徴としている。Means for Solving the Problems In order to achieve the above object, the present inventors have conducted intensive studies and studied to solve the above problems by making the diameter of the conduit outlet larger than the diameter of the conduit body. . That is, the invention according to claim 1 is a method for producing a glass gob by casting a molten glass flow continuously flowing from a conduit outlet into a mold provided below the conduit outlet, wherein the diameter of the conduit outlet is Is made larger than the main conduit.
【０００８】請求項２に記載の発明は、上記記載のガラ
スゴブの製造方法において、上記導管流出口の口径が導
管本管の１．２〜３．５倍の範囲であることを特徴とし
ている。本発明の方法によれば、溶融ガラスが導管を通
り流出口に達するが、ガラス自体の粘性と表面張力によ
り自然流下せず流出口に滞留する。この滞留時間あるい
は滞留量を決める因子は、ガラス組成とその温度（表面
張力と粘性）、流出口の口径である。つまり、流出口を
滴下する液滴の容量は、その液の表面張力と流出口口径
によって決定されるものであり、ガラス組成とその温度
が同一の場合、流出口口径が滞留時間あるいは滞留量の
支配因子となる。したがって、流出口の口径が導管と同
じ場合には、導管流出口の断面積が小さいため滞留時間
も短い。これに対し、流出口の口径を導管本管よりも大
きくした場合には、ガラスの滞留時間を長くすることが
できる。流出口の口径は溶融ガラスの種類および流出量
によって種々選び得るが、導管の口径の１．２〜３．５
倍の範囲とする。流出口の口径が導管の１．２倍以内で
は時間遅延の効果はほとんど認められず、３．５倍以上
ではガラスの滞留および流出がスム−スにいかないの
で、上記範囲が好ましい。According to a second aspect of the present invention, in the method for producing a glass gob described above, the diameter of the outlet of the conduit is 1.2 to 3.5 times the diameter of the main conduit. According to the method of the present invention, the molten glass reaches the outlet through the conduit, but stays at the outlet without spontaneously flowing down due to the viscosity and surface tension of the glass itself. Factors that determine the residence time or residence amount are the glass composition, its temperature (surface tension and viscosity), and the diameter of the outlet. In other words, the volume of the droplet dropped from the outlet is determined by the surface tension of the liquid and the outlet diameter, and when the glass composition and the temperature are the same, the outlet diameter is determined by the residence time or the amount of residence. Dominant factor. Therefore, when the diameter of the outlet is the same as that of the conduit, the residence time is short because the cross-sectional area of the conduit outlet is small. In contrast, when the diameter of the outlet is larger than that of the main pipe, the residence time of the glass can be lengthened. The diameter of the outlet can be variously selected depending on the type of molten glass and the amount of outflow, but the diameter of the conduit is 1.2 to 3.5.
Double the range. When the diameter of the outlet is less than 1.2 times the diameter of the conduit, the effect of the time delay is hardly recognized, and when the diameter is 3.5 times or more, the stagnation and outflow of the glass is not smooth, so the above range is preferable.
【０００９】[0009]
【発明の実施の形態】以下に本発明の詳細を図１〜４を
用いて説明する。図１〜４は、本発明の方法による溶融
ガラスのガラスゴブ成形プロセスの一例を示した断面図
である。また、図５〜９は本発明にかかる導管流出口の
各種形状を断面図にて示したものである。まず、溶融ガ
ラスは導管を通り流出口に達するが、流出口口径とガラ
ス自体の粘性と表面張力により自然流下せずに流出口に
滞留する。しかしガラスの滞留量が増加し、滞留の臨界
点を越えると、流出口口径と表面張力のバランスが破
れ、溶融ガラスは自然流下を始める(図１)。DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to FIGS. 1 to 4 are sectional views showing an example of a glass gob forming process of molten glass according to the method of the present invention. FIGS. 5 to 9 are sectional views showing various shapes of the conduit outlet according to the present invention. First, the molten glass reaches the outlet through the conduit, but stays at the outlet without spontaneously flowing down due to the outlet diameter, the viscosity of the glass itself, and the surface tension. However, when the amount of retained glass increases and exceeds the critical point of retention, the balance between the outlet diameter and the surface tension is broken, and the molten glass starts to flow naturally (FIG. 1).
【００１０】この自然流下を始めた溶融ガラス流を、中
型をその上端位置まで押し上げた成形型で受け、続いて
ガラスの流出量に応じて中型を徐々に下降させる(図
２、３)。溶融ガラス量が所定の量に達したら、成形型
全体を急速に下降させ溶融ガラス流をそのガラスの表面
張力を利用して切断する(図４)。切断後直ちに、成形型
を水平方向に移動させてガラスゴブ成形の一工程を終了
する。次の工程として、再び流出口に流れるガラス流は
流出口口径とガラスの粘性と表面張力とのバランスによ
り、一定時間流出口に滞留する。その間に、中型をその
上端位置まで押し上げた成形型を流出口の下部に設置
し、次のガラス流の流下を待機する。[0010] The molten glass flow which has started to flow naturally is received by a forming die which has raised the middle mold to its upper end position, and then the middle mold is gradually lowered in accordance with the outflow of glass (Figs. 2, 3). When the amount of molten glass reaches a predetermined amount, the entire mold is rapidly lowered to cut the molten glass flow by utilizing the surface tension of the glass (FIG. 4). Immediately after the cutting, the mold is moved in the horizontal direction to complete one step of glass gob molding. In the next step, the glass flow flowing to the outlet again stays at the outlet for a certain period of time due to the balance between the outlet diameter, the viscosity of the glass, and the surface tension. In the meantime, the forming die, which has pushed the middle die up to its upper end position, is placed below the outlet, and waits for the next glass flow.
【００１１】本発明の流出口の形状は、導管本管よりも
大きな口径を有するものならば特に限定されるものでは
ないが、図５〜９は、具体的な本発明にかかる導管流出
口の各種形状を示している。図５は、円錐状のもの。図
６は、異形管継手状のもの。図７は、釣鐘状のもの。
図８は、ラッパ状のもの。図９は、円錐状の中に形状維
持のため支持体を有するもの等を用いることができる。
以上の通り、流出口の形状は種々の形状を取り得るが、
ガラスゴブの形状をできるだけ真円状に近く取る必要か
ら、導管本体と流出口の断面形状については同心円であ
る必要がある。The shape of the outlet of the present invention is not particularly limited as long as it has a diameter larger than that of the main pipe of the conduit. FIGS. 5 to 9 show specific examples of the outlet of the conduit according to the present invention. Various shapes are shown. Figure 5 shows a conical shape. Fig. 6 shows a deformed pipe joint. Figure 7 shows a bell shape.
FIG. 8 shows a trumpet shape. In FIG. 9, a conical member having a support for maintaining the shape can be used.
As described above, the shape of the outlet can take various shapes,
Since it is necessary to make the shape of the glass gob as close as possible to a perfect circle, the cross-sectional shapes of the conduit body and the outlet need to be concentric.
【００１２】鋳型に鋳込まれたガラスが所定の量に達し
た時、ガラス流を切断する方法としては、鋳型全体を急
速に下降または中型のみを下降させてガラス流を切断す
ることができる。また、鋳型全体を水平方向に移動して
もガラス流を切断することができる。さらに、鋳型には
公知の方法である加圧ガスを送入する多孔質支持部材を
使用することもできる。As a method of cutting the glass flow when the amount of glass cast into the mold reaches a predetermined amount, the glass flow can be cut by rapidly lowering the entire mold or lowering only the middle mold. Further, the glass flow can be cut even when the entire mold is moved in the horizontal direction. Further, a porous support member for feeding a pressurized gas, which is a known method, may be used for the mold.
【００１３】[0013]
【発明の効果】本発明の請求項１に記載の方法によれ
ば、導管流出口口径は導管本管よりも大きいため、溶融
ガラスの流出口における表面張力とのバランスによっ
て、溶融ガラスの流出口におけるガラスの滞留時間を長
くすることができる。このように流出口における溶融ガ
ラスの滞留時間を長くすることにより、鋳型を所定の位
置に設置する時間を十分にとることができる。請求項２
に記載の方法によれば、上記流出口の口径を導管の口径
の１．２〜３．５倍の範囲において、流出口における溶
融ガラスの滞留時間を最適化することができる。さら
に、流出口口径を上記の範囲とすれば、得られたガラス
ゴブの形状は良好な円形にて取得できるのでガラスゴブ
材として有用である。According to the method of the first aspect of the present invention, since the diameter of the outlet of the conduit is larger than that of the main conduit, the outlet of the molten glass is balanced by the surface tension at the outlet of the molten glass. The residence time of the glass in the above can be lengthened. By thus increasing the residence time of the molten glass at the outlet, it is possible to obtain a sufficient time for installing the mold at a predetermined position. Claim 2
According to the method described in (1), the residence time of the molten glass at the outlet can be optimized when the diameter of the outlet is 1.2 to 3.5 times the diameter of the conduit. Further, when the outlet diameter is in the above range, the shape of the obtained glass gob can be obtained in a good circular shape, so that it is useful as a glass gob material.
【図１】本発明にかかるガラスゴブ成形プロセスの一例
を示したもので溶融ガラスが導管流出口に滞留している
ところを示している断面図である。FIG. 1 is a cross-sectional view showing an example of a glass gob forming process according to the present invention and showing a state where molten glass stays at a conduit outlet.
【図２】上記成形プロセスの中で、溶融ガラスが導管流
出口から鋳型に鋳込み始めたところを示している断面図
である。FIG. 2 is a cross-sectional view showing a state in which molten glass has begun to be cast into a mold from a conduit outlet during the forming process.
【図３】上記成形プロセスの中で、溶融ガラスが鋳型に
鋳込まれる量に応じて、鋳型の中型が下降しているとこ
ろを示している断面図である。FIG. 3 is a cross-sectional view showing a state where the middle mold of the mold is lowered in accordance with the amount of molten glass poured into the mold during the molding process.
【図４】上記成形プロセスの中で、溶融ガラスが鋳型に
所定量鋳込まれた後、鋳型全体が下降し、溶融ガラスを
切断するところを示している断面図である。FIG. 4 is a cross-sectional view showing that the molten glass is cast into a mold in a predetermined amount and then the entire mold is lowered to cut the molten glass in the molding process.
【図５】本発明の導管流出口の一例で、円錐状流出口の
断面図である。FIG. 5 is a sectional view of a conical outlet, which is an example of a conduit outlet according to the present invention.
【図６】上記流出口の一例で、異形管継手状流出口の断
面図である。FIG. 6 is a cross-sectional view of an example of the outlet, which is a deformed pipe joint-shaped outlet.
【図７】上記流出口の一例で、釣鐘状流出口の断面図で
ある。FIG. 7 is a cross-sectional view of a bell-shaped outlet, which is an example of the outlet.
【図８】上記流出口の一例で、ラッパ状流出口の断面図
である。FIG. 8 is a cross-sectional view of a trumpet-shaped outlet, which is an example of the outlet.
【図９】上記流出口の一例で、内部に支持体を有する円
錐状流出口の断面図である。FIG. 9 is a cross-sectional view of a conical outlet having a support therein as an example of the outlet.
１ 流出口 ２ 溶融ガラス ３ 中型 ４ 鋳型 1 Outlet 2 Molten glass 3 Medium size 4 Mold
Claims (2)
ラスを、導管流出口の下方に設けた鋳型に鋳込んでガラ
スゴブを製造する方法において、上記導管流出口の口径
を導管本管よりも大きくすることを特徴とするガラスゴ
ブの製造方法。1. A method for producing a glass gob by casting molten glass continuously flowing from a conduit outlet into a mold provided below the conduit outlet, wherein the diameter of the conduit outlet is set to be larger than that of the main pipe. A method for manufacturing a glass gob, characterized by increasing the size.
て、上記導管流出口の口径が導管本管の１．２〜３．５
倍の範囲であることを特徴とする、請求項１に記載のガ
ラスゴブの製造方法。2. The method of manufacturing a glass gob according to claim 1, wherein the diameter of the outlet of the conduit is 1.2 to 3.5 of the diameter of the main conduit.
The method for producing a glass gob according to claim 1, wherein the range is twice as large.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21304896A JPH1036123A (en) | 1996-07-24 | 1996-07-24 | Production of glass gob |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21304896A JPH1036123A (en) | 1996-07-24 | 1996-07-24 | Production of glass gob |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH1036123A true JPH1036123A (en) | 1998-02-10 |
Family
ID=16632669
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21304896A Pending JPH1036123A (en) | 1996-07-24 | 1996-07-24 | Production of glass gob |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH1036123A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2015078099A (en) * | 2013-10-18 | 2015-04-23 | Hoya株式会社 | Glass outflow device, glass outflow method, method of manufacturing preform for press molding, and method of manufacturing optical element |
-
1996
- 1996-07-24 JP JP21304896A patent/JPH1036123A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2015078099A (en) * | 2013-10-18 | 2015-04-23 | Hoya株式会社 | Glass outflow device, glass outflow method, method of manufacturing preform for press molding, and method of manufacturing optical element |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4249927A (en) | Method and apparatus for manufacturing glass products by controlling free flow of low viscosity molten glass | |
| JPH0234525A (en) | Method for forming glass element | |
| JPH1036123A (en) | Production of glass gob | |
| US5738701A (en) | Glass gob production device and production method | |
| JPH05147949A (en) | Production of glass gob and intermediate body of the same | |
| JP4026868B2 (en) | Optical element manufacturing method | |
| JP2000095531A (en) | Production of raw material for formation of optical element | |
| JP5243723B2 (en) | Nozzle and method of manufacturing optical glass block using the nozzle | |
| US20090107179A1 (en) | Glass passage and method of manufacturing molded product of optical glass using the passage | |
| JP3862589B2 (en) | Optical glass outflow device and method of manufacturing optical glass block | |
| JP2003040632A (en) | Production method for spherical glass, preform for press forming and press molding | |
| JP2008297159A (en) | Molten glass dropping nozzle, and method and apparatus for manufacturing shaped glass | |
| JP2004284847A (en) | Method of manufacturing glass lump and method of manufacturing optical element | |
| JPH0840726A (en) | Apparatus for forming glass material for molding | |
| CN101781084B (en) | Glass hot melt pore-forming technology and special device thereof | |
| JP2015145316A (en) | Nozzle and method of manufacturing optical glass lump using the nozzle | |
| JPH07291633A (en) | Production of glass | |
| JPH06345442A (en) | Production of highly homogeneous glass, apparatus therefor and product of highly homogeneous glass | |
| JP3140260B2 (en) | Method for manufacturing optical glass element | |
| JPH02157126A (en) | Method for adjusting glass discharge rate at nozzle part of glass melting tank | |
| GB2029818A (en) | Controlling Glass Feed | |
| JP2008280194A (en) | Glass flow passage and method for manufacturing optical glass formed body using the same | |
| JP2001180945A (en) | Method for manufacturing glass lens | |
| JP2002128529A (en) | Method of forming glass gob | |
| JP2005015300A (en) | Method for manufacturing glass formed article, and method for manufacturing optical element |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20060301 |
|
| A131 | Notification of reasons for refusal |
Effective date: 20060711 Free format text: JAPANESE INTERMEDIATE CODE: A131 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20060901 |
|
| A02 | Decision of refusal |
Effective date: 20061017 Free format text: JAPANESE INTERMEDIATE CODE: A02 |