JP2001151517A - Method of manufacturing optical device base material and manufacturing device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of an optical device base material capable of relatively inexpensively manufacturing a heavy weight optical device base material and an optical device base material manufacturing device using the same. SOLUTION: The optical device base material is obtained by using the manufacturing device provided with a holding vessel 2 for holding a molten glass 1, >=2 pieces of nozzles 3 communicating with the holding vessel 2 and a fusing unit 7 arranged below the nozzles 3, dropping the liquid drops 5 of the molten glass from the nozzles 3 to the fusing unit 7, fusing the liquid drops 5 of the dropped molten glass to each other in the fusing unit 7 to form fused liquid drops 6 and cooling the fused liquid drops 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing an optical element material used for manufacturing an optical element, and more particularly to a method for manufacturing a pickup optical system and a camera lens of an optical disk apparatus. The present invention relates to a method and an apparatus for producing an optical element material used for producing a glass molded optical element.

[0002]

2. Description of the Related Art In recent years, as a method of manufacturing an optical element such as a lens or a prism, there are many methods in which an optical element material is put into a mold and heated and pressed instead of a method of polishing an optical element material such as glass. Proposed.

[0003] As such a method, a so-called reheat press in which an optical element material preliminarily molded into a fixed shape (hereinafter referred to as "optical element material") is supplied into a mold, and heated and pressed to form the main element. The law is common. When such a method is adopted, in order to mold a precise optical element, the shape, surface smoothness and weight accuracy of the optical element material are very important requirements. Therefore, as an optical element material, a ball glass material obtained by polishing a glass material has been frequently used.

However, in recent years, productivity and cost have become more important, and a method utilizing the surface tension of molten glass, that is, a so-called direct method, has been adopted as a method for producing an optical element material. (For example,
JP-A-61-146721). The direct method is
As shown in FIG. 6, a molten glass 52 held in a holding container 51 is naturally dropped as a glass droplet 54 from a nozzle 53, and is collected in a container 55 to be used as an optical element material. At this time, the container 55
The distance L ₆ is such that the surface temperature of the glass droplet 54 can be lower than the softening temperature of the glass before the glass droplet 54 reaches the container 55, that is, the distance at which the surface of the glass droplet 54 can solidify. Is set to According to the direct method, since an operation of polishing a glass material or the like is unnecessary, it is possible to manufacture an optical element material at a relatively low cost.

[0005] In the direct method, the resulting optical element material has a weight substantially equal to the glass droplet 54. The weight of the glass droplet 54 is expressed by the following equation.

Mg = 2πrγ where m: weight of glass droplet [mg], g: gravitational acceleration [N / m], r: nozzle diameter [mm], γ: glass surface tension [N]. .
Therefore, in the conventional direct method, the weight of the optical element material, that is, the weight of the glass droplet 54 can be slightly adjusted by the temperature of the molten glass, but is mainly adjusted by the diameter of the nozzle 53. However, there is a limit to the weight of a glass droplet that can be dropped from one nozzle, and the limit value is 50.
It is said to be around 00mg.

[0007]

When an optical element requiring a large amount of optical material is formed, a large weight of the optical element material is required. As described above, the weight of the optical element material is determined by the diameter of the nozzle 53 in the conventional direct method.
The diameter must be increased. However, when the diameter of the nozzle becomes large, there is a problem that the weight of the dropped glass droplet tends to vary. Also, as described above, it is very difficult to drop glass droplets exceeding 5000 mg, no matter how large the nozzle diameter. Therefore, it has been substantially impossible with the conventional direct method to produce an optical element material having a large weight exceeding the limit weight of the glass droplet.

In order to form an optical element requiring a large amount of optical material, a method in which two or more optical element materials are charged into a mold and heated and pressurized to form the main element is also conceivable.
However, such a method has a problem that a boundary line between optical element materials remains in the optical element, and it has been difficult to obtain an optical element having a desired shape.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for manufacturing an optical element material capable of manufacturing a heavy optical element material at relatively low cost, and an optical element material manufacturing apparatus used for the method.

[0010]

To achieve the above object, the present invention provides a method of manufacturing an optical element material, comprising: supplying molten glass into a holding container; and supplying the molten glass from two or more nozzles communicating with the holding container. A glass droplet is dropped outside the holding container, and in a fusion device arranged below the nozzle,
Receiving the molten glass droplet dropped from one of the nozzles and the molten glass droplet dropped from another of the nozzles and fusing them together to form a fused droplet It is characterized by the following. In this specification, the “optical element material” is a molded optical material,
Further, it means an optical element that is formed by molding.

According to such a manufacturing method, it is possible to manufacture a heavy optical element material without excessively increasing the diameter of the nozzle, and it is possible to reduce the variation in the weight of the obtained optical element material. . Further, it becomes possible to manufacture a large-weight optical element material exceeding the limit weight of a glass droplet that can be dropped from one nozzle, which was practically impossible with the conventional direct method. Also, since the optical element material can be manufactured without processing such as polishing,
It is possible to reduce the manufacturing cost.

In the above manufacturing method, it is preferable that the fused droplets are discharged from the fusion device and the fused droplets are dropped. According to this preferred example, since the coalesced droplets are quickly cooled when falling, the production efficiency can be improved.

In the above-mentioned manufacturing method, it is preferable that the fused droplets are discharged from the fusion device and the fused droplets are rolled. According to this preferred example, since the coalesced droplets are sphericalized when rolling, an optical element material with high sphericity can be manufactured.

To achieve the above object, an optical element material manufacturing apparatus according to the present invention comprises: a holding container for holding molten glass;
Two or more nozzles communicating with the holding container and dropping the molten glass droplets out of the holding container, and the molten glass droplets disposed below the nozzles and dropped from one of the nozzles And a fusing device for receiving the molten glass droplets dropped from another one of the nozzles and fusing these with each other to form fused droplets.

According to such a manufacturing apparatus, a heavy optical element material can be manufactured without excessively increasing the diameter of the nozzle, and variation in the weight of the obtained optical element material can be reduced. . Further, it becomes possible to manufacture a large-weight optical element material exceeding the limit weight of a glass droplet that can be dropped from one nozzle, which was practically impossible with the conventional direct method. Also, since the optical element material can be manufactured without processing such as polishing,
It is possible to reduce the manufacturing cost.

In the optical element material manufacturing apparatus, it is preferable that the fusion device has an inclined surface which becomes lower from a portion for receiving the molten glass droplet to a portion for fusing the molten glass droplet. . This is because the molten glass droplets can be efficiently fused with each other.

Further, in the optical element material manufacturing apparatus, at least a portion of the fusion device which comes into contact with the molten glass droplet is made of a material having a thermal conductivity of 1 to 100 W / (m · K). Is preferred. According to this preferred example, since the droplets of the molten glass are hardly cooled in the fusion device, the droplets can be more reliably fused.

Further, in the optical element material manufacturing apparatus, it is preferable that the fusion device has a discharge port for discharging the fusion droplet. According to this preferred example, the fused droplets can be promptly processed in a post-process such as cooling.
Production efficiency can be improved.

Further, in the optical element material manufacturing apparatus, it is preferable that a container for accommodating the coalesced droplets discharged from the fusion device is arranged below the fusion device.
According to this preferred example, since the coalesced droplets can be quickly cooled when moving the coalesced droplets from the coalescing device to the container, the production efficiency can be improved.

In the optical element material manufacturing apparatus, at least a portion of the container that comes into contact with the coalesced droplets is made of a material having a thermal conductivity of 300 to 800 W / (m · K). preferable. According to this preferred example, since the coalesced droplets can be quickly cooled in the container, the production efficiency can be improved.

Further, in the optical element material manufacturing apparatus, it is preferable that a rolling table for receiving and rolling the fused droplet discharged from the fusion device is disposed below the fusion device. According to this preferred example, the fused droplets are sphericalized while rolling on the rolling table, so that an optical element material with high sphericity can be manufactured.

In the optical element material manufacturing apparatus, it is preferable that the rolling table has an inclined surface, and the fused droplet is rolled on the inclined surface. This is because the molten droplet can be efficiently rolled.

Further, in the optical element material manufacturing apparatus, at least a portion of the rolling table that comes into contact with the coalesced droplets is made of a material having a thermal conductivity of 300 to 800 W / (m · K). Is preferred. According to this preferred example, since the coalesced droplets can be rapidly cooled on the rolling table, the production efficiency can be improved.

Further, in the optical element material manufacturing apparatus, it is preferable that a container for accommodating the coalesced droplets rolled by the rolling table is further arranged.

[0025]

(First Embodiment) FIG. 1 is a sectional view of an optical element material manufacturing apparatus according to a first embodiment of the present invention. FIG. 1 also shows the structure of the optical element material manufacturing apparatus and the behavior of the molten glass droplet during use of the apparatus.

As shown in FIG. 1, the present manufacturing apparatus includes a holding container 2 and a fusion device 7 disposed below the holding container 2. The holding container 2 has two or more nozzles 3
Are joined.

The holding container 2 is a container for holding the molten glass 1, and has an input port for inputting a glass material,
And three or more nozzles 3. The holding container 2 can be made of, for example, platinum and an alloy such as platinum-gold and platinum-rhodium. Further, the holding container 2
For example, it is preferable to provide a means for increasing the temperature inside the container, such as the heater 4.

The nozzle 3 applies the molten glass 1 to a glass droplet 5
The nozzle is provided on the bottom surface of the holding container 2 so as to communicate with the holding container 2.
Although the number of the nozzles 3 is not particularly limited, two or more, preferably two to three are appropriate. In addition, nozzle 3
The interval between the two is not particularly limited, but is preferably 1 mm or more. Although the diameter of the nozzle 3 is adjusted according to the weight of the target optical element material, it is 1 mm or more, preferably about 5 to 50 mm. The two or more nozzles 3 provided in the holding container 2 are not particularly limited, but preferably have substantially the same diameter.

The fusion device 7 is a container for receiving the glass droplets 5 dropped from each nozzle 3 and fusing the glass droplets 5 together to form a fused glass droplet 6. That is, in the fusion device 7, a portion where the glass droplet lands (hereinafter, referred to as a glass droplet)
This will be referred to as a “droplet landing section”. ) And a place where the glass droplets are fused (hereinafter, referred to as a “droplet fusion portion”). As a matter of course, there are a plurality of droplet landing points corresponding to the number of nozzles 3.

The fusion device 7 has an inclined surface formed so as to face the open end of the nozzle 3. The inclined surface includes at least one droplet landing portion, and is provided so as to be lower in a direction from the droplet landing portion toward the droplet fusion portion. For example, as shown in FIG. 1, the shape may be a shape having an inclined surface that becomes lower from the edge to the center, that is, a shape having a V-shaped or substantially V-shaped cross-section. In this case, the inclined surface near the edge corresponds to the droplet landing portion,
The central part corresponds to the droplet fusion part. The angle of the slope is 1 °
As described above, it is preferably adjusted to about 10 to 30 °. Further, a plurality of the fusion devices 7 may be mounted on a rotatable member.

The fusion device 7 is preferably made of a material having a relatively low thermal conductivity. The material constituting the fusion device 7 preferably has a thermal conductivity of 1 to 100 W / (m · K). Specifically, it is preferable to be composed of ceramics such as alumina, zirconia and silicon nitride.

The distance L ₁ from the tip of the nozzle 3 to the droplet landing portion of the fusion device 7 depends on the glass droplet 5 that has reached the fusion device 7.
Is a distance at which the temperature becomes equal to or higher than the softening temperature, and is 10 mm or more, preferably about 100 to 300 mm. Also,
It is preferable that the distance L ₁ be set so as to be substantially equal for each nozzle 3.

Next, a method for manufacturing an optical element material using the above-described manufacturing apparatus will be described.

First, the molten glass 1 is supplied into the holding container 2. The molten glass 1 is supplied from the input port to the holding container 2.
After the solid glass material is put into the inside, the temperature inside the holding container 2 is raised by the heater 4 to melt the glass material. Further, as the molten glass 1, barium borosilicate-based glass, hydrofluoric acid-based glass, or the like can be used.

When the molten glass 1 is supplied into the holding container 2, the molten glass 1 is spheroidized by surface tension at the tip of the nozzle 3, and a glass droplet 5 is formed. In another nozzle 3, a glass droplet 5 is similarly formed.

Eventually, the glass droplet 5 formed by each nozzle 3 falls onto the fusion device 7. At this time, a plurality of glass droplets 5 fall on the fusion device 7 in accordance with the number of nozzles. Each glass droplet 5 moves to the droplet fusion portion while rotating on an inclined surface provided in the fusion device 7. In the droplet fusion section, the glass droplets 5 fuse with each other to form one fused glass droplet 6.

Thereafter, the fused glass droplet 6 is cooled at least until its surface is solidified, preferably naturally cooled, to obtain an optical element material.

The optical element material obtained by the above-described manufacturing apparatus and manufacturing method can be used for forming an optical element. The method for forming the optical element is not particularly limited, and a method commonly used in the related art can be employed. For example, a method of cooling an optical element material to a temperature equal to or lower than the glass transition point, charging the optical element material into a mold, and heating and pressurizing the mold to form a desired shape can be adopted. Molding conditions are usually 500 ° C to 600 ° C.
It is appropriate to set the pressing force to 686 N or more.

According to the present embodiment, the weight of the optical element material can be adjusted not only by the diameter of the nozzle but also by the number of nozzles. be able to. In addition, since an operation of polishing a glass material is unnecessary, it is possible to manufacture an optical element material at a relatively low cost.

(Second Embodiment) FIG. 2 shows a second embodiment of the present invention.
It is sectional drawing of the optical element material manufacturing apparatus in embodiment. FIG. 2 shows the structure of the optical element material manufacturing apparatus together with the behavior of the molten glass droplet during use of the apparatus. In FIG. 2, members and the like that perform the same functions are given the same numbers as in FIG.

As shown in FIG. 2, the present manufacturing apparatus comprises a holding container 2 and a fusion discharging device 8 disposed below the holding container 2.
And a container 9 arranged below the fusion discharger 8. Further, two or more nozzles 3 are joined to the holding container 2.

The holding container 2 and the nozzle 3 can have the same configuration as in the first embodiment.

The fusion discharger 8 is a container that receives the glass droplets 5 dropped from each nozzle 3 and fuses the glass droplets 5 into a fusion glass droplet 6, and discharges the fusion glass droplet 6. is there. That is, in the fusion discharger 8, a portion where the glass droplet lands (hereinafter, referred to as a “droplet landing portion”).
And a portion where the glass droplets are fused (hereinafter referred to as a “droplet fusion portion”), and an outlet for discharging the fused glass droplets. As a matter of course, there are a plurality of droplet landing portions corresponding to the number of the nozzles 3.

The fusion discharge device 8 is usually configured as a container having a discharge nozzle formed on the bottom surface, and an inclined surface formed to face the opening end of the nozzle 3 of the holding container is provided inside the container. I have. The inclined surface includes at least one droplet landing portion, and is provided so as to be lower in a direction from the droplet landing portion toward the discharge nozzle. For example, as shown in FIG. 2, the bottom surface of the container may be provided with an inclined surface that becomes lower from the edge to the center, and a discharge nozzle may be provided at the center. In this case, the inclined surface near the edge corresponds to the droplet landing portion, the inside of the discharge nozzle corresponds to the droplet fusion portion, and the opening end of the discharge nozzle corresponds to the discharge port. The diameter of the discharge nozzle is 1 mm or more, preferably 5 to 50 m
m. The angle of the inclined surface is adjusted to 1 ° or more, preferably about 10 to 30 °.

Further, as shown in FIG. 3, it is preferable that the fusion discharging device 8 is provided with a means for controlling the temperature inside the fusion discharging device 8, such as a heater 12, for example.

The distance L ₂ from the tip of the nozzle 3 to the droplet landing portion of the fusion discharger 8 is defined as a distance at which the temperature of the glass droplet 5 reaching the fusion discharger 8 becomes equal to or higher than the softening temperature.
mm or more, preferably about 100 to 300 mm.
Further, it is preferable that the distance L ₂ is set so as to be substantially equal for each nozzle 3.

The container 9 is a container for receiving the fused glass droplet 6 discharged from the fusion discharging device 8. Container 9
Is not particularly limited as long as it has an open top. Further, a plurality of containers 9 may be mounted on a rotatable member.

The container 9 is preferably made of a material having a relatively high thermal conductivity. Alternatively, the inner surface of the container 9 is preferably covered with a member made of a material having a relatively high thermal conductivity. The thermal conductivity of such materials is
300-800W / (mK), 600-800
It is preferably W / (m · K). Specifically, glassy carbon, copper, or the like can be used.

The distance L ₃ from the tip of the discharge nozzle of the fusion discharger 8 to the droplet landing portion of the container 9 is not particularly limited, but is not less than 10 mm, preferably 50 mm.
It is about 200 mm.

Next, a method of manufacturing an optical element material using the above-described manufacturing apparatus will be described.

First, similarly to the first embodiment, when the molten glass 1 is supplied into the holding container 2, a glass droplet 5 is formed at each tip of the nozzle 3. Eventually, each nozzle 3
The glass droplet 5 formed in the step (1) falls on the fusion discharger 8. At this time, a plurality of glass droplets 5 drop onto the fusion discharger 8 according to the number of nozzles. Each glass droplet 5
Moves on the inclined surface provided in the fusion discharger 8 into the droplet fusion part, that is, the discharge nozzle. In the discharge nozzle of the fusion discharger 8, the glass droplets 5 fuse with each other to form one fusion glass droplet 6.

The fused glass droplet 6 is discharged from the discharge nozzle of the fused discharger 8 and falls onto the container 9. afterwards,
The fused glass droplet 6 is cooled at least until the surface is solidified, preferably naturally cooled, and becomes an optical element material.

The optical element material obtained by the above-described manufacturing apparatus and manufacturing method can be used for forming an optical element as in the first embodiment.

According to this embodiment, the same effect as that of the first embodiment can be realized. Furthermore, according to the present embodiment, it is possible to cool the fused glass droplet relatively quickly, and it is possible to improve production efficiency.

(Third Embodiment) FIG. 4A is a sectional view of an optical element material manufacturing apparatus according to a third embodiment of the present invention, and FIG. 4B is a partial sectional view thereof. In addition,
FIGS. 4A and 4B also show the structure of the optical element material manufacturing apparatus and the behavior of the molten glass droplet during use of the apparatus. FIGS. 4A and 4B
In, about the member etc. which perform the same function,
1 and 2 are assigned the same numbers.

As shown in FIG. 4A, the present manufacturing apparatus
Holding container 2, fusion ejector 8 arranged below holding container 2, and rolling table 10 arranged below fusion ejector 8
And a container 11. Further, two or more nozzles 3 are joined to the holding container 2.

Holding container 2, nozzle 3 and fusion discharger 8
Can have the same configuration as that of the above-described second embodiment.

The rolling table 10 is a member for receiving the fused glass droplet 6 discharged from the fusion discharging device 8 and rolling it. The rolling table 10 is usually configured as a member having an inclined surface, and the inclined surface is arranged so as to face the opening end of the discharge nozzle of the fusion discharger 8. That is,
The fused glass droplet 6 is configured to land on the inclined surface (hereinafter, a portion where the glass droplet lands is referred to as a “droplet landing portion”). The angle of the inclined surface is usually 1 to 60.
°, preferably about 10 to 30 °.

The rolling table 10 is preferably made of a material having a relatively high thermal conductivity. Alternatively, it is preferable to cover the inclined surface of the rolling table 10 with a member made of a material having a relatively high thermal conductivity. The thermal conductivity of such a material is 300 to 800 W / (m · K), and furthermore 600 to 8
It is preferably 00W / (m · K). Specifically, glassy carbon, copper, or the like can be used.

The distance L ₅ from the tip of the discharge nozzle of the fusion discharger 8 to the droplet landing point on the rolling table 10 is not particularly limited, but is not less than 10 mm, preferably 5 mm.
It is about 0 to 150 mm.

The container 11 is a container for accommodating the fused glass droplet 6 that has rolled on the inclined surface of the rolling table 10, and is arranged below the inclined surface of the rolling table 10. Also,
The shape and material of the container 11 are not particularly limited as long as the container has an opening.

Next, a method for manufacturing an optical element material using the above-described manufacturing apparatus will be described.

First, as in the second embodiment, when the molten glass 1 is supplied into the holding container 2, glass droplets 5 are formed at each nozzle 3, and the glass droplets 5 are fed to the fusion discharger 8.
Fall on. In the fusion ejector 8, the glass droplet 5
Fused together, one fused glass droplet 6 is formed.

The fused glass droplet 6 is discharged from the discharge nozzle of the fused discharger 8 and falls on the inclined surface of the rolling table 10. As shown in FIG. 4B, the dropped fused glass droplet 6 moves while rotating on the inclined surface of the rolling table 10 and is accommodated in the container 11. Then, the fused glass droplet 6
Is cooled at least until the surface is solidified, preferably naturally cooled, to form an optical element material.

The optical element material obtained by the above-described manufacturing apparatus and manufacturing method can be used for forming an optical element as in the first embodiment.

According to this embodiment, the same effect as that of the second embodiment can be realized. Further, according to the present embodiment, the fused glass droplet is adjusted to a spherical shape with higher sphericity while being cooled quickly by rolling on the inclined surface of the rolling table. Therefore, it is possible to rapidly cool the fused glass droplets to improve the production efficiency, and to manufacture an optical element material having a very good shape.

[0067]

EXAMPLE (Example 1) An optical element material was manufactured using a manufacturing apparatus having the structure shown in FIG. As the holding container, a platinum container having two nozzles was used. Nozzles are 2
The diameter is set to 4 so that 500 mg of glass droplets can be dropped.
It was set to 3 mm. In addition, as a fusion device, an inclination angle of 4
An alumina ceramic container having a 0 ° inclined surface was used. The distance L ₁ between the member was set to 150 mm.

A solid barium borosilicate glass was charged into the holding container, and the glass was melted by raising the heater provided to the holding container to 1200 ° C. to obtain a molten glass.
Drops of molten glass were allowed to fall naturally from the nozzle onto the fusion device. After the two glass droplets rolled on the inclined surface of the fusion device, they fused together to form one fused glass droplet. After the fused glass droplet was cooled naturally until the surface solidified, it was taken out of the fused device using tweezers to obtain an optical element material.

Next, as shown in FIG. 5, the optical element material 13 cooled to a temperature lower than the glass transition point is molded into a cylindrical metal mold 31 in which a pair of upper and lower molds 32 and 33 are arranged. Put in the mold, temperature 580 ° C, pressing force 687N
Under the conditions described above, a glass lens was obtained. It was confirmed that the obtained glass lens was formed into a desired shape on both surfaces.

Example 2 An optical element material was manufactured using a manufacturing apparatus having the structure shown in FIG. As the holding container, a platinum container having two nozzles was used. The diameter of the nozzle was set to 43 mm so that 2500 mg of glass droplets could be dropped. As a fusion ejector, an inclination angle of 3
A platinum container having a 0 ° inclined surface was used. A glassy carbon container was used as the container.
The distance L ₂ and L ₃ between the respective members were each set to 150 mm.

A solid barium borosilicate glass was charged into the holding container, and the glass was melted by raising the heater provided in the holding container to 1200 ° C. to obtain a molten glass.
Drops of molten glass were allowed to spontaneously fall from each nozzle onto the fusion ejector. The two glass droplets rolled on the inclined surface of the fusion ejector and fused together to form one fusion glass droplet. Thereafter, the fused glass droplets fell from the discharge nozzle of the fusion discharger onto the container. After the fused glass droplet was naturally cooled until the surface solidified, it was taken out of the container using tweezers to obtain an optical element material.

Next, the obtained optical element material was molded in the same manner as in Example 1 to obtain a glass lens. It was confirmed that the obtained glass lens was formed into a desired shape on both surfaces.

Example 3 An optical element material was manufactured using a manufacturing apparatus having the structure shown in FIGS. 4A and 4B.
As the holding container, a platinum container having two nozzles was used. The diameter of the nozzle was set to 43 mm so that 2500 mg of glass droplets could be dropped. A platinum container having an inclined surface with an inclination angle of 30 ° was used as the fusion ejector. The rolling table and the container were made of glassy carbon, and the angle of inclination of the rolling table was set to 30 °. The distances L ₄ and L ₅ between the members are 150 mm and 10 mm, respectively.
It was set to 0 mm.

A solid barium borosilicate glass was charged into the holding container, and a heater provided in the holding container was turned on.
The temperature was raised to 0 ° C. and melted to obtain a molten glass. Drops of molten glass were allowed to spontaneously fall from each nozzle onto the fusion ejector. The two glass droplets rolled on the inclined surface of the fusion ejector and fused together to form one fusion glass droplet. Thereafter, the fused glass droplets fell from the nozzle of the fused discharger onto the inclined surface of the rolling table and started rolling, and were eventually accommodated in the container. The fused glass droplet was naturally cooled until the surface solidified, and then taken out of the container using tweezers to obtain an optical element material.

Next, the obtained optical element material was molded in the same manner as in Example 1 to obtain a glass lens. It was confirmed that the obtained glass lens was formed into a desired shape on both surfaces.

[0076]

As described above, according to the method of manufacturing an optical element material of the present invention, molten glass is supplied into a holding container and the liquid of the molten glass is supplied from two or more nozzles communicating with the holding container. Drops are dropped out of the holding container, and in a fusion device arranged below the nozzle, one of the nozzles
Receiving the molten glass droplet dropped from one of the nozzles and the molten glass droplet dropped from another of the nozzles and fusing them together to form a fused droplet, Can be manufactured relatively inexpensively.

Further, according to the optical element material manufacturing apparatus of the present invention, a holding container for holding the molten glass, and at least two liquid droplets of the molten glass which are communicated with the holding container and which drop the molten glass outside the holding container. A nozzle, disposed below the nozzle, receiving the molten glass droplet dropped from one of the nozzles, and receiving the molten glass droplet dropped from another of the nozzles, And a fusing device for forming fusing droplets by fusing with each other, making it possible to manufacture a heavy optical element material at a relatively low cost.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an optical element material manufacturing apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional view of an optical element material manufacturing apparatus according to a second embodiment of the present invention.

FIG. 3 is a partial cross-sectional view showing a preferred embodiment of an optical element material manufacturing apparatus according to a second embodiment of the present invention.

FIG. 4A is a cross-sectional view of an optical element material manufacturing apparatus according to a third embodiment of the present invention, and FIG. 4B is a view showing a behavior of a fused glass droplet in the present manufacturing apparatus.

FIG. 5 is a cross-sectional view of an optical element molding die used in an example.

FIG. 6 is a cross-sectional view illustrating a method of manufacturing an optical element material according to a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Molten glass 2 Holding container 3 Nozzle 4 Heater 5 Glass droplet 6 Fused glass droplet 7 Fused device 8 Fused ejector 9 Container 10 Rolling stand 11 Container 12 Heater 13 Optical element material 31 Body mold 32 Upper mold 33 Lower Mold 51 Holding container 52 Molten glass 53 Nozzle 54 Glass droplet 55 Container

Claims (13)

[Claims] 1. A molten glass is supplied into a holding container, droplets of the molten glass are dropped from the two or more nozzles communicating with the holding container to the outside of the holding container, and fusion is disposed below the nozzle. Receiving the molten glass droplet dropped from one of the nozzles and the molten glass droplet dropped from another of the nozzles, and fusing these with each other to form a fused droplet Forming an optical element material. 2. The method of manufacturing an optical element material according to claim 1, further comprising discharging the fused droplet from the fusion device and dropping the fused droplet. 3. The method for manufacturing an optical element material according to claim 1, further comprising discharging the fused droplet from the fusion device and rolling the fused droplet. 4. A holding container for holding the molten glass, two or more nozzles communicating with the holding container and dropping the droplets of the molten glass out of the holding container, the nozzle being disposed below the nozzle, Receiving the molten glass droplet dropped from one of the nozzles and the molten glass droplet dropped from another of the nozzles and fusing them together to form a fused droplet An optical element material manufacturing apparatus, comprising: 5. The optical element material production according to claim 4, wherein the fusion device has an inclined surface which becomes lower from a portion for receiving the molten glass droplet to a portion for fusing the molten glass droplet. apparatus. 6. At least a portion of the fusion device in contact with the molten glass droplet has a thermal conductivity of 1 to 100 W / (m · K)
The optical element material manufacturing apparatus according to claim 4, wherein the optical element material manufacturing apparatus is made of the following material. 7. The optical element material manufacturing apparatus according to claim 4, wherein the fusion device has an outlet for discharging the fusion droplet. 8. The optical element material manufacturing apparatus according to claim 7, wherein a container that stores the coalesced liquid droplets discharged from the fusion device is disposed below the fusion device. 9. The optical element material manufacturing apparatus according to claim 8, wherein at least a portion of the container that comes into contact with the coalesced droplets is made of a material having a thermal conductivity of 300 to 800 W / (m · K). . 10. The optical element material manufacturing apparatus according to claim 7, wherein a rolling table that receives the fused droplets discharged from the fusion device and rolls it is disposed below the fusion device. 11. The optical element material manufacturing apparatus according to claim 10, wherein the rolling table has an inclined surface, and the fused droplet rolls on the inclined surface. 12. The optical element according to claim 10, wherein at least a portion of the rolling table that contacts the coalesced droplet is made of a material having a thermal conductivity of 300 to 800 W / (m · K). Material production equipment. 13. The optical element material manufacturing apparatus according to claim 10, further comprising a container that stores the fused droplet rolled by the rolling table.