JP2001226126A - Forming method of optical glass element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical glass element having excellent yield by mitigating the temperature change of an optical glass blank and reducing the dispersion of precision in middle thickness. SOLUTION: This forming method of the optical glass element is constituted in such a manner that a holder 21 holding the optical glass blank 24 is heated in a holder heating furnace 20 and, thereafter, is carried to a forming chamber 15 with a carrying arm 22 and the optical glass blank 24 is press-formed by a pair of forming dies 16, 17 to obtain the optical glass element. Therein, the tip part 22a of the carrying arm 22 is on standby in the holder heating furnace 20 before the holder 21 holding the optical glass blank 24 is mounted on the tip part 22a of the carrying arm 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming an optical glass element at a low cost by manufacturing a precise optical glass element by pressing.

[0002]

2. Description of the Related Art In recent years, the need for an aspherical lens has been increasing in order to satisfy the demand for reducing the number of lens systems in order to improve the performance and cost of the lens itself. Means of finishing glass materials by spherical polishing has been used for a long time to manufacture glass lenses, but it is very difficult to manufacture aspheric lenses by polishing with current technology,
At present, it is difficult to make a profit. Therefore, development of technology for manufacturing an aspherical lens by press molding has been particularly actively conducted.

Conventionally, as one of means for forming a glass lens, there is a forming method in which an optical glass material heated in a heating furnace is conveyed and pressed between a pair of forming dies facing vertically. For example, Japanese Patent Publication No. 3-64453 discloses a technique in which a glass gob is heated and formed while being conveyed as described below. This technique will be described with reference to FIGS. 7 is a front view of the molding machine, FIG. 8 is a plan view of the molding machine, and FIGS. 9 to 11 are explanatory views showing a process of transporting the gob plate.

In FIGS. 7 and 8, an upper die 109 and a lower die 110 are vertically arranged inside a molding chamber 108 so as to face each other. The lower mold 110 is driven up and down by a main shaft 111. A main heating furnace 106 is provided adjacent to the molding chamber 108, and a preheating furnace 1 is provided next to the main heating furnace 106.
03 is provided. In the preheating furnace 103, the conveying member 102 is sequentially conveyed in the direction of arrow A. The conveying member 102 is provided with a plurality of holes, and holds a glass gob 107 which is an optical glass material. Gob dish 1
01 is inserted. The transfer arm 105 can transfer the gob dish 101 in the preliminary heating furnace 103 between the upper mold 109 and the lower mold 110 in the molding chamber 108 after passing through the main heating furnace 106.

Next, a method for forming an optical glass element will be described. First, the gob plate 101 holding the glass gob 107 is placed on the transfer member 102, and the transfer member 102 is transferred into the preheating furnace 103. In the preheating furnace 103, as the molding operation proceeds, the gob plate 101
Is carried forward in the direction of arrow A. As shown in FIG. 9, when the gob dish 101 comes above the push-up member 104, as shown in FIG.
04 is lifted, the gob plate 101 is lifted, and as shown in FIG.
And transfer the gob plate 101 to the second place. Thereafter, the transfer arm 105 is further advanced, and the gob plate 1 is placed inside the main heating furnace 106.
Move 01.

When the glass gob 107 placed on the gob plate 101 in the heating furnace 106 has a predetermined viscosity, the transfer arm 105 is further advanced, and the molding chamber 10
8, the gob plate 101 is conveyed between the upper mold 109 and the lower mold 110, and the main shaft 111 is driven to raise the lower mold 110,
The glass gob 107 is pressed. After the molded optical glass element is solidified, the lower mold 110 is lowered by the main shaft 111, and the gob plate 101 is placed on the transfer arm 105. Thereafter, the transfer arm 105 is pulled back directly above the push-up member 104, and the operation is opposite to the operation of placing the gob plate 101 from the transfer member 102 on the transfer arm 105,
The gob plate 101 is placed on the conveying member 102, and the molding operation is completed.

[0007]

However, the above prior art has the following problems. That is, in the standby time during the molding operation after the main heating time is over, and in the standby time between one molding operation and the next molding operation,
Since the tip of the transfer arm is exposed outside the heating furnace, the temperature of the tip of the transfer arm decreases. Therefore, at the moment when the gob plate is placed on the transfer arm in the preheating furnace, the transfer arm takes heat from the gob plate. Since the distal end of the transfer arm is exposed to the outside temperature of the heating furnace that fluctuates depending on the outside air temperature and the indoor environment, the temperature of the distal end changes with each molding. For this reason, the temperature of the gob plate placed at the tip of the transfer arm also changes every time, and the deformation amount of the glass gob fluctuates, thereby deteriorating the filling accuracy and yield of the formed optical glass element. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention according to claims 1, 2 and 3 is to reduce a temperature change of an optical glass material and to achieve a variation in medium precision. It is an object of the present invention to provide a method for molding an optical glass element having a good yield and a good yield.

[0009]

According to a first aspect of the present invention, a holder holding an optical glass material is heated in a holder heating furnace and then transferred to a molding chamber by a transfer arm. In the method of molding an optical glass element by pressing and molding the optical glass material with a pair of molds to obtain an optical glass element, the tip of the transfer arm is placed before placing a holder holding the optical glass material, Waiting in the holder heating furnace.

According to a second aspect of the present invention, a holder holding an optical glass material is heated in a holder heating furnace and then transferred to a forming chamber by a transfer arm, and the optical glass material is pressed and formed by a pair of forming dies. In the method for molding an optical glass element by which an optical glass element is obtained, the transfer arm is on standby in the holder heating furnace when not used during the molding operation.

According to a third aspect of the present invention, there is provided a method for forming an optical glass element by pressing a softened optical glass material with a pair of molds to obtain an optical glass element. Simultaneously heating the tip of the transfer arm for transferring the holder in the holder heating furnace, holding the holder at the tip of the heated transfer arm, and holding the holder holding the optical glass material. The method includes a step of transporting the optical glass material to a molding chamber by a transport arm and a step of press-molding the optical glass material with a pair of molding dies.

In the method for forming an optical glass element according to the first aspect of the present invention, the distal end of the transfer arm stands by in the holder heating furnace before placing the holder holding the optical glass material. Even if the holder holding the optical glass material heated in the holder heating furnace is placed on the tip of the transfer arm, heat conduction does not occur between the tip of the transfer arm and the holder, and the optical glass material Temperature does not change.

In the method for molding an optical glass element according to the second aspect of the present invention, when the transfer arm is not used during the forming operation, the transfer arm is on standby in the holder heating furnace, so that the front end of the transfer arm can be used. Even if the holder holding the optical glass material before molding or the molded optical glass element is placed, the temperature of the optical glass material before molding does not change, and the molded optical glass element may be rapidly cooled. Absent.

According to a third aspect of the invention, there is provided a method for forming an optical glass element, wherein a holder holding an optical glass material and a tip of a transfer arm for transferring the holder are simultaneously heated in a holder heating furnace; A step of holding the holder at the tip of the heated transfer arm, a step of transferring the holder holding the optical glass material to the forming chamber by the transfer arm, and a step of press-forming the optical glass material with a pair of forming dies. By having, even if the holder is held at the end of the heated transfer arm, heat conduction does not occur between the end of the transfer arm and the holder, and the temperature of the optical glass material does not change. In the step of press-molding the optical glass material with a pair of molds, the amount of deformation does not vary.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments will be described.

(Embodiment 1) FIGS. 1 to 5 show Embodiment 1 and FIG. 1 is a front view of an optical glass element forming apparatus.
FIG. 2 is a plan view of an optical glass element forming apparatus, and FIGS.
FIG. 4 is an explanatory diagram showing a process of transferring a holder from a transfer member to a transfer arm.

In FIG. 1, an upper mold 16 and a lower mold 17 as a pair of molding dies are arranged in a molding chamber 15 of an optical glass element molding apparatus with their molding surfaces facing each other. The base end of the upper die 16 is fixed to the top plate 15a of the molding chamber 15, and the base end of the lower die 17 is fixed to a main shaft 18 that can move in the arrow Z direction by a cylinder (not shown). A main heating furnace 19 is disposed adjacent to the molding chamber 15, and a preheating furnace 20 as a holder heating furnace is disposed adjacent to the main heating furnace 19. Preheating furnace 2
0, as shown in FIG. 2, the transport member carrying-in port 20a so that the transport member 23 can pass through the inside thereof in the arrow X direction.
And a transport member outlet 20b. The transport member 23 has a shape in which a plurality of (four in the present embodiment) holes 23a are formed in a plate material, and a holder 21 (see FIG. 1) is placed in the holes 23a, and a rail (not shown) It can be moved up.

As shown in FIG. 1, the holder 21 has a substantially ring shape, and has an insertion hole 21a for inserting a push-up member 26 described later. A tapered portion 21 b whose diameter is reduced downward is formed on the outer peripheral surface of the holder 21, and the tapered portion 21 b is
The holder 21 is held by each member by fitting it to the end 3a of the transfer arm 22 (see FIG. 4). Further, on the inner peripheral surface of the holder 21, a mounting portion 21c protruding inward is formed to mount the outer peripheral portion of the optical glass material 24.

In FIG. 2, the preheating furnace 20 has a transfer arm 22 passing therethrough in an arrow Y direction which is a direction perpendicular to an arrow X direction and an arrow Z direction (see FIG. 1). Arm carry-in port 20c and arm carry-out port 20
d is formed. That is, in the preheating furnace 20, the transfer arm 22 crosses over the transfer member 23 and passes therethrough. The transfer arm 22 has a front end portion 22a cut out in a U-shape,
Upper mold 16 and lower mold 17 in main heating furnace 19 and molding chamber 15
(See FIG. 1). Further, on the side surface of the preheating furnace 20, the tip portion 22 of the transfer arm 22 is provided.
A projection 20e is formed to protrude in the direction of arrow Y so that a can be heated while waiting.

On the other hand, on the lower surface of the preheating furnace 20, a push-up member 26 movable vertically by a cylinder 27 is disposed at a lower position where the transfer arm 22 and the transfer member 23 intersect as shown in FIG. Has been established. As shown in FIG. 3, the push-up member 26 has a step 26a formed at an upper end thereof, and the step 26a is inserted into the insertion opening 21a of the holder 21.
By inserting the holder 21 (see FIG. 1), the holder 21 can be pushed up from the hole 23a of the transport member 23 as shown in FIG.

Next, a method of molding an optical glass element using the molding apparatus having the above structure, that is, a molding operation will be described. In the present embodiment, a convex lens (optical glass element) having an outer diameter of 13 mm was formed using OHARA S-BAL1 as a glass material (optical glass material). First, as shown in FIG.
The optical glass material 24 is placed and held on the placement portion 21c of the holder 21. Then, the holder 21 holding the optical glass material 24 is placed in the hole 23 a of the transport member 23.
Note that the number of holders 21 placed on the transport member 23 is arbitrary.

Next, as shown in FIG. 2, the conveying member 23 on which the holder 21 is placed is moved in the direction of the arrow X, and the preheating furnace 20 set at a predetermined temperature (450 ° C. in the present embodiment). Insert into. Here, the transport member 23 is intermittently moved in the arrow X direction every tact time (35 seconds in the present embodiment). Then, the holder 21 is heated together with the optical glass material 24 in the preheating furnace 20. At the same time, the vicinity of the distal end portion 22a of the transfer arm 22 is inserted into the protrusion 20e of the preheating furnace 20 for heating, and the vicinity of the step 26a of the push-up member 26 is inserted into the preheating furnace 20 for heating. . (See FIG. 1). Thereby, the holder 2
1. The tip 22a of the transfer arm 22 and the step 26a of the push-up member 26 have the same temperature as the set temperature of the preheating furnace 20. The positions of the transfer arm 22 and the push-up member 26 when the distal end portion 22a of the transfer arm 22 and the step portion 26a of the push-up member 26 are heated in the preheating furnace 20 are standby positions (indicated by broken lines in FIG. 1). Position).

When the holder 21 on the transfer member 23 is positioned on the vertical line of the push-up member 26 by the movement of the transfer member 23, as shown in FIG.
(See FIG. 1), the push-up member 26 starts to rise. When the push-up member 26 rises, the step portion 26a
Is inserted into the insertion hole 21a (see FIG. 1) of the holder 21, and as shown in FIG. 4, abuts against the lower surface of the mounting portion 21c (see FIG. 1) of the holder 21 to push up the holder 21 from the transport member 23. . Next, the projection 20e of the preheating furnace 20
The transfer arm 22 waiting in the inside is advanced in the Y-axis direction, and the front end portion 22a is positioned below the pushed-up holder 21. Thereafter, when the push-up member 26 is lowered, as shown in FIG.
1 b is fitted and mounted on the distal end portion 22 a of the transfer arm 22.

During the operation shown in FIGS. 3 to 5, since the temperature of the holder 21, the tip portion 22a of the transfer arm 22, and the step portion 26a of the push-up member 26 are equal, no heat conduction occurs between them. After it is confirmed that the holder 21 is mounted on the transfer arm 22 in a correct posture, the transfer arm 22 is advanced in the Y-axis direction, and a predetermined temperature (920 in this embodiment) is set.
(° C.) into the main heating furnace 19. And
When the optical glass material 24 held by the holder 21 is heated to a predetermined temperature, the transfer arm 22 is further advanced in the direction of arrow Y, and the tip 22a is moved to the upper mold 16 and the lower mold 17 of the molding chamber 15. , Ie, to the molding position.

Next, by raising the main shaft 18, the lower die 17 is raised and inserted into the insertion hole 21a of the holder 21. Further, when the lower mold 17 is raised, the optical glass material 24 held by the holder 21 is lifted,
This optical glass material 24 is pressed and formed by the upper die 16 and the lower die 17. At this time, the holder 21 is placed on the peripheral surface 17a of the lower mold 17 (see FIG. 1). During this press forming, the transfer arm 22 is retracted, and temporarily stands by at a standby position in the preheating furnace 20. And the optical glass material 24
Just before the end of the molding of the transfer arm 2
2 is advanced and moved to the molding position. After press molding,
By lowering the lower mold, the molded optical glass element is lowered together with the lower mold 17 and released from the upper mold 16.
Further, by lowering the lower die 17, the holder 21 placed on the peripheral surface 17 a of the lower die 17
2 and the molded optical glass element on the lower mold 17 is placed on the holder 21. At this time, since the transfer arm 22 is waiting at the standby position in the preheating furnace 20, no rapid heat conduction occurs between the holder 21 and the transfer arm 22, and the formed optical glass element is distorted. Does not occur.

Thereafter, the transfer arm 22 on which the holder 21 is placed is retracted in the direction of arrow Y, and stopped when the holder 21 is positioned on the vertical line of the push-up member 26 (FIG. 5).
reference). Then, after the holder 21 is pushed up from the transfer arm 22 by the push-up member 26, the transfer arm 22 is retracted and made to stand by at a standby position (see FIG. 4). Thereafter, the push-up member 26 is lowered, and the holder 21 holding the formed optical glass element is returned to the hole 23a of the transport member 23 (see FIG. 3). Then, the transport member 23 moves in the direction of the arrow X, and positions the holder holding the next optical glass material on the vertical line of the push-up member 26. By repeating this operation, a plurality of optical glass elements can be obtained.

When 500 shots were continuously formed by the above-mentioned forming method, no forming defect occurred. In addition, the variation of the thickness change of the optical glass element is 25 μm.
Was able to be suppressed. For comparison, when the transfer arm was continuously formed for 500 shots without being kept in a preheating furnace, the forming yield was 96%, and 4% of molding defects called cans occurred. The variation in the amount of change in the thickness of the optical glass element was 35 μm.

According to the present embodiment, the temperature of the holder can be stabilized by keeping the transfer arm, the push-up member and the holder in the heating furnace for as long as possible, so that the variation in the thickness of the optical glass element can be reduced. It is possible to obtain an optical glass element having a reduced yield, a good yield and no distortion.

(Embodiment 2) FIG. 6 shows Embodiment 2 and is a perspective view of a transfer arm. The optical glass element molding apparatus of the present embodiment is different from the optical glass element molding apparatus of the first embodiment only in the transfer arm, and the other parts are the same as those of the first embodiment. Illustration and description of the same parts are omitted.

In FIG. 6, a cartridge heater 32 is embedded inside the transfer arm 31. In the optical glass element forming apparatus, the position where the transfer arm 31 is provided is the same as the position of the transfer arm 22 of the first embodiment, and the cartridge heater 32 is connected to a temperature control mechanism (not shown). Other configurations are described in Embodiment 1.
Is the same as

Next, the operation of the transfer arm 31 in which the cartridge heater 32 is embedded will be described. In order to stably maintain the temperature at the tip of the transfer arm, it is necessary to keep the tip of the transfer arm at a predetermined ambient temperature for a long time.
Since the transfer arm moves in an environment having different ambient temperatures in a short time, it is difficult to stabilize the temperature at the moment when the holder 21 is placed on the transfer arm. Therefore, in the present embodiment, the temperature of the transfer arm is positively controlled by using a dedicated heater. The cartridge heater 32 embedded inside the transfer arm 31 heats the transfer arm 31 from the inside in response to a command from a temperature control mechanism (not shown) to prevent the temperature of the distal end portion 31 a of the transfer arm 31 from lowering.

Next, the method of forming an optical glass element using the forming apparatus having the above-described structure is the same as that of the first embodiment except for the portion where the transfer arm 31 is heated by the cartridge heater 32. Omitted.

In this embodiment, OHARA S-BAL41 is used as the glass material (optical glass material), and the outer diameter is 13 mm.
mm convex lens (optical glass element) was molded. The temperature of the preheating furnace 20 (see FIG. 1) and the cartridge heater 32 is 450 ° C., and the temperature of the main heating furnace 19 (see FIG. 1) is 940.
When 500 shots were continuously formed at a temperature of 30 ° C. and a tact time of 30 seconds, the variation in the amount of change in the medium thickness was 25 μm. Also, there was no molding failure. For comparison, when 500 shots were continuously formed without using the cartridge heater 32, the temperature of the heating furnace had to be 955 ° C. to obtain a good product. Although no molding failure occurred, the variation in the amount of change in the medium thickness was 35 μm.

According to the present embodiment, in addition to the effects of the first embodiment, the tact time can be shortened by positively controlling the temperature of the transfer arm.

The following technical ideas can be derived from the above specific embodiments. (Supplementary Note) (1) In the method for forming an optical glass element, wherein a holder on which an optical glass material placed in a heating furnace is placed is transported between molding dies facing up and down using a transport arm. A method for molding an optical glass element, wherein when a holder is placed on a transfer arm, no heat energy enters and exits between the transfer arm and the holder.

According to the appendix (1), when the holder is placed on the transfer arm, there is no heat energy between the transfer arm and the holder, so that the temperature of the optical glass material placed on the holder is reduced. Does not change, the variation in the accuracy of the medium thickness is reduced, and an optical glass element with a good yield can be obtained.

(2) The method for forming an optical glass element according to (1), wherein the transfer arm is simultaneously heated in a heating furnace for heating the holder while the holder is being heated.

According to the supplementary note (2), in addition to the effect of the supplementary note (1), by making the atmosphere for heating the holder and the atmosphere for heating the transfer arm the same, the holder and the transfer arm can be easily and accurately connected. The temperature can be equal.

(3) In a method of forming an optical glass element by press-molding a heat-softened optical glass material with a pair of molding dies, the optical glass material is press-molded with a pair of molding dies. Wherein the transfer arm is waiting in a preheating furnace.

Since the transfer arm is waiting in the preheating furnace, the molded optical glass element is not rapidly cooled even if the holder holding the formed optical glass element is placed on the transfer arm. Since it is conveyed from the molding position to the preheating furnace, an optical glass element without distortion can be obtained.

(4) After heating the holder holding the optical glass material in the preheating furnace, the holder is transferred to the forming chamber by the transfer arm, and the optical glass material is pressed and formed by a pair of forming dies to form the optical glass element. In the method for molding an optical glass element to be obtained, the tip of the push-up member and the tip of the transfer arm that push up the holder to be placed on the transfer arm are placed before the holder holding the optical glass material is placed. A method for forming an optical glass element, wherein the optical glass element is on standby in the preheating furnace.

According to appendix (4), the tip of the push-up member and the tip of the transfer arm which push up the holder to be mounted on the transfer arm are preheated before the holder holding the optical glass material is mounted. By waiting in the furnace, even if the tip of the push-up member contacts the holder, the holder holding the optical glass material heated in the holder heating furnace is placed on the tip of the transfer arm. Since heat conduction does not occur between the members and the temperature of the optical glass material does not change, variations in the accuracy of the medium thickness can be reduced, and an optical glass element having a good yield can be obtained.

(5) After the holder holding the optical glass material is heated in a preheating furnace, it is transferred to a forming chamber by a transfer arm, and the optical glass material is pressed and formed by a pair of forming dies to form an optical glass element. In the method for molding an optical glass element to be obtained, the push-up member and the transfer arm that push up to mount the holder on the transfer arm,
A method for forming an optical glass element, wherein the apparatus is in a standby state in the preheating furnace when not used during the forming operation.

According to the supplementary note (5), since the push-up member and the transfer arm are waiting in the preheating furnace,
Even if the optical glass material before molding or the holder holding the molded optical glass element is placed on the transfer arm, the temperature of the optical glass material before molding does not change, and the molded optical glass element is rapidly cooled. Therefore, the variation in the accuracy of the medium thickness can be reduced, and an optical glass element having a good yield and no distortion can be obtained.

(6) In a method of forming an optical glass element by pressing a softened optical glass material with a pair of molding dies to obtain an optical glass element, a holder holding the optical glass material and transferring the holder Simultaneously heating the distal end of the transfer arm in a holder heating furnace, holding the holder at the heated distal end of the transfer arm, and forming the holder holding the optical glass material in a molding chamber with the transfer arm. Transporting the optical glass material with a pair of molds, and returning the distal end of the transport arm once into the preheating furnace during the pressure molding of the optical glass material. A method for forming an optical glass element, comprising:

According to appendix (6), even if the holder is held at the end of the heated transfer arm, no heat conduction occurs between the end of the transfer arm and the holder, and the temperature of the optical glass material is reduced. Does not change, and the amount of deformation does not vary in the step of pressing the optical glass material with a pair of molds. Also, by returning the tip of the transfer arm once into the preheating furnace, even if the holder holding the formed optical glass element is placed on the transfer arm, the formed optical glass element is not rapidly cooled. Is transferred from the molding position to the preheating furnace. Therefore, it is possible to reduce the variation in the accuracy of the medium thickness, to obtain an optical glass element having a good yield and no distortion.

[0047]

According to the first aspect of the present invention, even if the holder holding the optical glass material heated in the holder heating furnace is placed on the tip of the transfer arm, the tip of the transfer arm is kept in contact with the tip of the transfer arm. Since no heat conduction occurs between the holder and the holder, and the temperature of the optical glass material does not change, variations in the accuracy of the medium thickness can be reduced, and an optical glass element with a high yield can be obtained.

According to the second aspect of the present invention, the optical glass material before molding or the holder holding the formed optical glass element is placed on the tip of the transfer arm, Since the temperature does not change and the molded optical glass element is not quenched, it is possible to reduce the variation in the accuracy of the medium thickness and to obtain an optical glass element having a good yield and no distortion.

According to the third aspect of the present invention, even if the holder is held at the end of the heated transfer arm, heat conduction does not occur between the end of the transfer arm and the holder, and the optical glass material Temperature does not change, and in the step of press-molding the optical glass material with a pair of molds, the amount of deformation does not vary, so that variations in medium wall accuracy are reduced and an optical glass element with a good yield is obtained. be able to.

[Brief description of the drawings]

FIG. 1 is a front view of an optical glass element molding apparatus according to a first embodiment.

FIG. 2 is a plan view of the optical glass element forming apparatus according to the first embodiment.

FIG. 3 is an explanatory diagram illustrating a process of transferring the holder from the transfer member to the transfer arm according to the first embodiment;

FIG. 4 is an explanatory diagram illustrating a process of transferring the holder from the transfer member to the transfer arm according to the first embodiment.

FIG. 5 is an explanatory diagram illustrating a process of transferring the holder from the transfer member to the transfer arm according to the first embodiment.

FIG. 6 is a perspective view of a transfer arm according to the second embodiment.

FIG. 7 is a front view of a conventional molding machine.

FIG. 8 is a plan view of a conventional molding machine.

FIG. 9 is an explanatory view showing a transfer process of a gob plate according to the related art.

FIG. 10 is an explanatory diagram showing a transfer process of a gob plate according to the related art.

FIG. 11 is an explanatory view showing a process of transporting a gob plate according to the related art.

[Description of Signs] 15 Molding chamber 16 Upper mold 17 Lower mold 20 Preheating furnace 21 Holder 22 Transfer arm 22a Tip 24 Optical glass material

Claims (3)

[Claims] 1. An optical glass element is obtained by heating a holder holding an optical glass material in a holder heating furnace, and then transporting the optical glass material to a molding chamber by a transport arm, and pressing the optical glass material by a pair of molds. In the method for forming an optical glass element, the tip of the transfer arm is in a standby state in the holder heating furnace before placing the holder holding the optical glass material, the optical glass element being formed. Method. 2. A holder holding an optical glass material is heated in a holder heating furnace and then transferred to a forming chamber by a transfer arm, and the optical glass material is pressed and formed by a pair of forming dies to obtain an optical glass element. In the method for molding an optical glass element, the transfer arm is in a standby state in the holder heating furnace when not used during the molding operation. 3. A method of forming an optical glass element by pressing a softened optical glass material with a pair of molds to obtain an optical glass element, comprising: a holder holding the optical glass material; and a holder for transferring the holder. Simultaneously heating the tip of the transfer arm in the holder heating furnace, holding the holder at the tip of the heated transfer arm, and transferring the holder holding the optical glass material to the molding chamber with the transfer arm. A method of molding an optical glass element, comprising: a step of conveying the optical glass material; and a step of pressing and molding the optical glass material with a pair of molds.