JP2008297156A - Apparatus and method for manufacturing optical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus and a method for manufacturing an optical device, with which the quantity of an inert gas supplied to a molding chamber is reduced and the concentration of oxygen in the molding chamber is lowered. <P>SOLUTION: The apparatus 1 for molding the optical device by charging a molding set 40 housing an optical device base material to the molding chamber 10 to mold the optical device is provided with: inert gas supply means (21, 22) for supplying the inert gas (arrow head A1) to the molding chamber 10; a catalyst chamber 31 in which a catalyst capable of absorbing oxygen contained in the inert gas; and an inert gas circulation path 32 having a circulating inlet 32c and a circulation outlet 32d provided to the molding chamber 10 to circulate the inert gas (arrow head A2) in the molding chamber 10 to the catalyst chamber 31. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical element manufacturing apparatus and manufacturing method for manufacturing optical elements such as lenses, prisms, and mirrors, and more specifically, the amount of inert gas supplied to the molding chamber can be reduced and the interior of the molding chamber can be reduced. The present invention relates to an optical element manufacturing apparatus and manufacturing method capable of reducing the oxygen concentration.

  Conventionally, as an optical element manufacturing method for manufacturing an optical element such as a glass lens with high accuracy and at low cost, the optical element material that has been heated and softened in the mold set is cooled and solidified by pressing the optical element material. A method of obtaining an optical element by molding and transferring a surface shape or surface roughness onto an optical element material is used.

  When the optical element is manufactured as described above, the mold set is heated to a temperature at which the optical element material can be molded in addition to the optical element material. Therefore, it is necessary to continue supplying an inert gas such as nitrogen to the molding chamber so that the mold set does not deteriorate due to oxidation (see, for example, Patent Document 1). By continuously supplying the inert gas to the molding chamber in this way, the atmosphere in the molding chamber is maintained at an inert gas atmosphere and at a positive pressure, thereby reducing the inflow of oxygen from the outside to the molding chamber. be able to.

As a method of manufacturing an optical element for reducing the oxygen concentration in a molding chamber, a method for reducing the oxygen concentration of an inert gas before flowing into the molding chamber by disposing a substance that is easily oxidized in a chamber separate from the molding chamber Has also been proposed (see, for example, Patent Document 2).
JP-A-4-164826 Japanese Utility Model Publication No. 2-10438

  By the way, in the manufacturing method described in Patent Document 1, the mold set is sequentially and continuously inserted into the manufacturing apparatus at every fixed tact time, and sequentially discharged after the optical element is molded. Therefore, even though the mold set is exposed to a high temperature and is in the middle of molding, when the inlet shutter for carrying another mold set into the molding chamber is opened, and the mold set is discharged from the molding chamber. When the discharge shutter for opening is opened, the molding chamber may be opened to the atmosphere and oxygen may flow into the molding chamber.

  Therefore, in the manufacturing method described in Patent Document 1, it is necessary to supply a large amount of inert gas in order to maintain an inert gas atmosphere by always maintaining a positive pressure in the molding chamber, and the manufacturing cost of the optical element is reduced. It was very expensive.

  Further, in the manufacturing method described in Patent Document 2, since the oxygen concentration of the inert gas before flowing into the molding chamber is reduced, the oxygen concentration of the inert gas in the molding chamber cannot be reduced so much. . Therefore, in order to always maintain a positive pressure in the molding chamber and maintain an inert gas atmosphere, there is no significant difference from the manufacturing method described in Patent Document 1 in that a large amount of inert gas needs to be supplied. Therefore, even with the manufacturing method described in Patent Document 2, the manufacturing cost of the optical element has been increased.

  In view of the above-described conventional situation, an object of the present invention is to provide an optical element manufacturing apparatus and method capable of reducing the amount of inert gas supplied to a molding chamber and reducing the oxygen concentration in the molding chamber. Is to provide.

  In order to solve the above-described problems, an optical element manufacturing apparatus according to the present invention is an optical element manufacturing apparatus in which a mold set containing an optical element material is placed in a molding chamber and the optical element is molded. An inert gas supply means for supplying an active gas, a catalyst chamber in which a catalyst for absorbing oxygen contained in the inert gas is disposed, a circulation inlet and a circulation outlet are located in the molding chamber, and the inert gas in the molding chamber An inert gas circulation path for circulating gas through the catalyst chamber.

Moreover, it is good to set it as the structure further equipped with the ventilation means which forcibly circulates the inert gas in the said molding chamber to the said catalyst chamber.
Moreover, it is good to set it as the structure further provided with the heating means which heats the said catalyst.

Moreover, it is good to set it as the structure further equipped with the flow volume control means which controls the flow volume of the said inert gas which flows through the inside of the said inert gas circulation path.
Further, it may be configured to further include a gas deflecting unit that is provided at or near the circulation outlet of the inert gas circulation path and deflects the inert gas flowing into the molding chamber from the inert gas circulation path.

  In order to solve the above problems, an optical element manufacturing method of the present invention is an optical element manufacturing method in which a mold set containing an optical element material is put into a molding chamber to mold the optical element. The optical element is molded in a state where the inert gas in the molding chamber is circulated through a catalyst chamber in which an active gas is supplied and a catalyst that absorbs oxygen contained in the inert gas is disposed.

  In the present invention, by molding the optical element in a state where the inert gas in the molding chamber is circulated into the catalyst chamber, oxygen can be absorbed by the catalyst even when oxygen flows into the molding chamber. Therefore, it is not necessary to supply a large amount of inert gas to the molding chamber in order to reduce the oxygen concentration in the molding chamber. Therefore, according to the present invention, the amount of inert gas supplied to the molding chamber can be reduced, and the oxygen concentration in the molding chamber can be reduced.

Hereinafter, an optical element manufacturing apparatus and a manufacturing method according to embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a sectional view showing an optical element manufacturing apparatus 1 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing the catalyst chamber 31 of the optical element manufacturing apparatus 1.

  An optical element manufacturing apparatus 1 shown in FIG. 1 includes a molding chamber 10, an inert gas supply source 21 and an inert gas supply path 22 as an inert gas supply means, a catalyst chamber 31, an inert gas circulation path 32, and the like. Yes.

  Although described later in detail, the optical element manufacturing apparatus 1 molds an optical element from an optical element material (not shown) accommodated in the mold set 40 in the molding chamber 10. The mold set 40 of the present embodiment is composed of the upper mold 41, the lower mold 42, and the trunk mold 43, but the mold set 40 may be composed of other combinations.

In the molding chamber 10, a first heating stage 11, a second heating stage 12, a press stage 13, a first cooling stage 14, and a second cooling stage 15 are disposed.
The first heating stage 11 includes an upper heater block 11a that is in contact with the upper surface of the mold set 40, an upper heat insulating block 11b disposed above the upper heater block 11a, and a press shaft 11c connected to the upper heat insulating block 11b. And a cylinder 11d for raising and lowering the press shaft 11c, a lower heater block 11e on which the die set 40 is placed, and a lower heat insulating block 11f disposed below the lower heater block 11e (others) Since the stages 12 to 15 have the same configuration, the same reference numerals are assigned to FIG.

  On the outside of the molding chamber 10 on the side where the first heating stage 11 is disposed, a loading table 16 on which a mold set 40 to be loaded into the molding chamber 10 is placed is provided, and a second cooling stage 15 is disposed. A discharge table 17 on which the mold set 40 discharged from the molding chamber 10 is placed is provided on the outside of the molding chamber 10 on the formed side. Further, a closing shutter 10a that is opened when the mold set 40 is loaded from the loading table 16 into the molding chamber 10 is provided outside the molding chamber 10 on the loading table 16 side. A discharge shutter 10 b that opens when the mold set 40 is discharged from the molding chamber 10 to the discharge table 17 is provided outside.

  An inert gas (arrow A1) such as nitrogen is supplied from an inert gas supply source 21 via an inert gas supply path 22 to the upper part of the molding chamber 10 on the mold set 40 input side by a supply mechanism (not shown). Yes. The molding chamber 10 may be formed with a fine gap for driving out oxygen in the molding chamber 10 together with the inert gas. Even in this case, since the positive pressure in the molding chamber 10 is maintained by supplying the inert gas (arrow A1) from the inert gas supply source 21, the inflow of oxygen from the minute gap is suppressed. Can do.

  The catalyst chamber 31 arranged in parallel with the molding chamber 10 has one end and the other end of the catalyst chamber 31 through the inert gas circulation path 32 on the side where the second cooling stage 15 is disposed. Connected with.

  In the catalyst chamber 31, a granular catalyst 31a that absorbs oxygen contained in the inert gas (arrow A2) in the molding chamber 10 is disposed. Any catalyst that can absorb oxygen, such as iron, copper, nickel, or a compound containing these, can be used as the catalyst 31a. Therefore, the catalyst 31a does not need to be granular. It should be noted that the catalyst 31a may be periodically replaced because it becomes difficult to absorb oxygen when it is heated by a catalyst heater 35 described later and changed to iron oxide, copper oxide, nickel oxide, or the like.

  A circulation inlet 32 c and a circulation outlet 32 d that are both ends of the inert gas circulation path 32 are located in the molding chamber 10, and the inert gas (arrow A <b> 2) in the molding chamber 10 is circulated to the catalyst chamber 31.

  The inert gas circulation path 32 is connected to the first circulation path 32a connected to the molding chamber 10 (circulation inlet 32c) and the catalyst chamber 31, and to the catalyst chamber 31 and molding chamber 10 (circulation outlet 32d). The second circulation path 32b is configured.

  As shown in FIG. 2, a net 31b having a mesh smaller than the particle size of the catalyst 31a is arranged on the bottom surface in the catalyst chamber 31 so that the catalyst 31a does not fall into the second circulation path 32b. The net 31 b is disposed on the upper step of the both-end stepped hole 31 c that penetrates the bottom of the catalyst chamber 31. The end of the second circulation path 32b is fitted to the lower step of the both-end stepped hole 31c.

The catalyst chamber 31 may be a portion where the catalyst 31a is disposed, such as a portion that holds the catalyst 31a inside the inert gas circulation path 32 (flow path).
As shown in FIG. 1, the inert gas (arrow A3) flowing into the molding chamber 10 from the inert gas circulation path 32 is deflected to the circulation outlet 32d of the inert gas circulation path 32 (second circulation path 32b). A wind deflection plate 18 is provided as a gas deflection means.

  The wind deflector 18 deflects the inert gas (arrow A3) in a direction away from the mold set 40 so that the inert gas (arrow A3) flowing into the molding chamber 10 does not easily hit the mold set 40 being molded. It is good to arrange in.

  The wind deflector 18 may be disposed in the vicinity of the circulation outlet 32d, for example, in the second circulation path 32b, on the side wall of the molding chamber 10, or the like. Further, as the gas deflection means, for example, a member in which a plurality of through holes are formed so as to disperse the flow of the inert gas (arrow A3) in multiple directions can be used.

  The first circulation path 32a is provided with a blower 33 as a blowing means for forcibly circulating the inert gas (arrow A2) in the molding chamber 10 to the catalyst chamber 31. It should be noted that the inert gas (arrow A2) in the molding chamber 10 can be forcedly circulated through the catalyst chamber 31 by providing other forced circulation means such as a compressor instead of the blower 33 (blower means). Is possible.

  The first circulation path 32a is provided with a flow rate regulator 34 as a flow rate control means for controlling the flow rate of the inert gas (arrow A2) flowing through the first circulation path 32a closer to the catalyst chamber 31 than the blower 33. It is installed.

The flow regulator 34 may be composed only of a throttle valve, but may be a device including a flow rate display unit, an adjustment operation unit, and the like in addition to the throttle valve.
As shown in FIG. 2, a catalyst heater 35 as a heating unit for heating the catalyst 31 a is disposed on the outer periphery of the catalyst chamber 31. A temperature measuring device 36 (not shown in FIG. 2) is inserted into the catalyst 31a in the catalyst chamber 31. A temperature control device 37 is connected to the catalyst heater 35 and the temperature measuring device 36.

  The temperature control device 37 can heat the catalyst to an arbitrary temperature by transmitting a control signal to the catalyst heater 35 and receiving a temperature measurement value signal from the temperature measuring device 36.

Hereinafter, the manufacturing method of an optical element is demonstrated.
First, the upper heater blocks 11a, 12a, 13a, 14a, and 15a and the lower heater blocks 11e, 12e, 13e, 14e, and 15e shown in FIG. 1 are suitable for each stage (heating, pressing, and cooling) by control means (not shown). Set the temperature to the desired temperature and keep that temperature.

  Further, an inert gas (arrow A1) such as nitrogen is continuously supplied from the inert gas supply source 21 to the molding chamber 10 via the inert gas supply path 22 by a supply mechanism (not shown). Thereby, oxygen in the molding chamber 10 is exhausted from the fine gap or the open shutter 10a or the exhaust shutter 10b, and the atmosphere in the molding chamber 10 is replaced with an inert atmosphere and maintained at a positive pressure.

Then, the mold set 40 containing the optical element material is conveyed to the loading table 16, the closing shutter 10 a is opened, and the mold set 40 is loaded into the molding chamber 10.
The mold set 40 put into the molding chamber 10 is placed on the lower heater block 11e of the first heating stage 11. Then, the press shaft 11c is lowered by driving the cylinder 11d, and the mold set 40 and the optical element material accommodated in the mold set 40 are heated by heat conduction from the upper heater block 11a and the lower heater block 11b.

  The mold set 40 heated in the first heating stage 11 is transferred to the second heating stage 12 by a transfer means (not shown) and heated in the same manner as the first heating stage 11. By heating in this way, the optical element material in the mold set 40 is softened.

  Next, the mold set 40 is transferred to the press stage 13 and pressed on the press stage 13 until the optical element material has a target thickness. After the optical element material is pressed, the mold set 40 is sequentially transferred to the first cooling stage 14 and the second cooling stage 15 to be cooled. Thereby, the optical element material is solidified and the optical element is molded.

  After the molding of the optical element in the molding chamber 10 as described above is completed, the mold set 40 of the second cooling stage 15 is discharged from the molding chamber 10 to the discharge table 17 by opening the discharge shutter 10b.

In the optical element manufacturing apparatus 1, the mold set 40 as described above is sequentially charged into the molding chamber 10 and discharged from the molding chamber 10, and the optical elements are continuously manufactured.
During the molding of the optical element, the inert gas (arrow A <b> 2) in the molding chamber 10 flows through the inert gas circulation path 32 and circulates through the catalyst chamber 31. When the blower 33 is operated, the inert gas (arrow A2) in the molding chamber 10 can be forcibly circulated through the catalyst chamber 31.

  If the flow rate (circulation amount) of the inert gas in the inert gas circulation path 32 is excessively increased by the blower 33, unnecessary convection occurs in the molding chamber 10, and the molding temperature of the mold set 40 and the accuracy of the optical element are increased. Therefore, it is preferable to adjust the flow rate by the blower 33 after comparing the oxygen absorption amount and the occurrence of convection.

  Further, during the molding of the optical element, unnecessary convection in the molding chamber 10 as described above can be prevented by suppressing the flow rate of the inert gas by the flow rate regulator 34. In addition, when operating the blower 33 at the same time, the flow rate adjustment can be facilitated by using the flow rate regulator 34 instead of changing the operating state (the number of rotations, etc.) of the blower 33.

  Further, during the molding of the optical element, the catalyst 31a can be heated to an arbitrary temperature by the catalyst heater 35 described above. The heating temperature of the catalyst 31a may be set to a temperature at which the catalyst 31a can effectively absorb oxygen, for example. When it is desired to promote the absorption of oxygen by the catalyst 31a, the catalyst 31a may be set according to a temperature at which the catalyst 31a is likely to chemically change to iron oxide, copper oxide, nickel oxide, or the like.

  In the present embodiment described above, when the optical element is molded in a state where the inert gas (arrow A2) in the molding chamber 10 is circulated through the catalyst chamber 31, oxygen flows into the molding chamber 10. Also, oxygen can be absorbed by the catalyst 31a. Therefore, it is not necessary to supply a large amount of inert gas to the molding chamber 10 in order to reduce the oxygen concentration in the molding chamber 10. Therefore, according to the present embodiment, the supply amount of the inert gas (arrow A1) to the molding chamber 10 can be reduced and the oxygen concentration in the molding chamber 10 can be reduced.

  In the present embodiment, a blower 33 for forcibly circulating the inert gas (arrow A2) in the molding chamber 10 to the catalyst chamber 31 is disposed. Therefore, the speed at which the oxygen concentration in the molding chamber 10 is reduced can be increased, and therefore the amount of inert gas (arrow A1) supplied to the molding chamber 10 can be further reduced and the oxygen in the molding chamber 10 can be reduced. The concentration can be further reduced.

  In the present embodiment, since the catalyst heater 35 for heating the catalyst 31a is disposed, the catalyst 31a can absorb oxygen effectively, and the amount of oxygen absorbed by the catalyst 31a can be adjusted. Can do. Therefore, the supply amount of the inert gas (arrow A1) to the molding chamber 10 can be further reduced, and the oxygen concentration in the molding chamber 10 can be reduced.

  In the present embodiment, since the flow rate regulator 34 for controlling the flow rate of the inert gas flowing in the inert gas circulation path 32 is disposed, the amount of oxygen absorbed by the catalyst 31a can be adjusted. . Furthermore, by appropriately reducing the flow rate of the inert gas, unnecessary convection in the molding chamber 10 can be suppressed, and deterioration of the accuracy of the optical element due to the temperature change of the mold set 40 can be prevented. Furthermore, when the flow rate regulator 34 is used together with the blower 33, the amount of oxygen absorbed by the catalyst 31a can be adjusted without changing the operating state (rotation speed, etc.) of the blower 33.

  Further, in the present embodiment, the inert gas (arrow A3) provided at the circulation outlet 32d of the inert gas circulation path 32 (second circulation path 32b) and flowing into the molding chamber 10 from the inert gas circulation path 32 is supplied. A wind deflector 18 for deflecting is disposed. Therefore, it is possible to make it difficult for the inert gas (arrow A3) flowing into the molding chamber 10 from the inert gas circulation path 32 to hit the mold set 40 during molding. Therefore, the optical element caused by the temperature change of the mold set 40 can be prevented. Accuracy deterioration can be prevented.

  In the present embodiment, the optical element manufacturing apparatus 1 has been described as a circulation type manufacturing apparatus that forms an optical element while transferring the mold set 40 to a plurality of stages 11 to 15. Even in another manufacturing apparatus such as a manufacturing apparatus that performs pressing and cooling in the same place, the inert gas (arrow A2) in the molding chamber 10 is circulated in the catalyst chamber 31 as in the present embodiment. Thus, the above-described effect can be obtained.

It is sectional drawing which shows the optical element manufacturing apparatus which concerns on one embodiment of this invention. It is sectional drawing which shows the catalyst chamber of the optical element manufacturing apparatus which concerns on one embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical element manufacturing apparatus 10 Molding chamber 10a Input shutter 10b Discharge shutter 11 1st heating stage 12 2nd heating stage 13 Press stage 14 1st cooling stage 15 2nd cooling stage 11a, 12a, 13a, 14a, 15a Upper heater block 11b , 12b, 13b, 14b, 15b Upper heat insulating block 11c, 12c, 13c, 14c, 15c Press shaft 11d, 12d, 13d, 14d, 15d Cylinder 11e, 12e, 13e, 14e, 15e Lower heater block 11f, 12f, 13f, 14f, 15f Lower heat insulating block 16 Input base 17 Discharge base 18 Wind deflection plate 21 Inert gas supply source 22 Inert gas supply path 31 Catalyst chamber 31a Catalyst 31b Net 31c Both-ends stepped hole 32 Inert gas circulation path 32a First circulation Road 32 b Second circulation path 32c Circulation inlet 32d Circulation outlet 33 Blower 34 Flow rate regulator 35 Catalyst heater 36 Temperature measuring device 37 Temperature control device 40 Mold set 41 Upper mold 42 Lower mold 43 Body mold

Claims (6)

In an optical element manufacturing apparatus for molding an optical element by putting a mold set containing an optical element material into a molding chamber,
An inert gas supply means for supplying an inert gas to the molding chamber;
A catalyst chamber in which a catalyst that absorbs oxygen contained in the inert gas is disposed;
A circulation inlet and a circulation outlet are located in the molding chamber, and an inert gas circulation path for circulating an inert gas in the molding chamber to the catalyst chamber;
An optical element manufacturing apparatus comprising:   The optical element manufacturing apparatus according to claim 1, further comprising a blowing unit that forcibly circulates the inert gas in the molding chamber to the catalyst chamber.   The apparatus for manufacturing an optical element according to claim 1, further comprising heating means for heating the catalyst.   The optical element manufacturing apparatus according to claim 1, further comprising a flow rate control unit configured to control a flow rate of the inert gas flowing through the inert gas circulation path.   2. A gas deflecting unit that is provided at or near the circulation outlet of the inert gas circulation path and deflects the inert gas flowing into the molding chamber from the inert gas circulation path. Or the manufacturing apparatus of the optical element of Claim 2. In the method of manufacturing an optical element in which an optical element is molded by putting a mold set containing an optical element material into a molding chamber,
The optical element is molded in a state where the inert gas in the molding chamber is circulated through a catalyst chamber in which an inert gas is supplied to the molding chamber and a catalyst that absorbs oxygen contained in the inert gas is disposed. A method for manufacturing an optical element.

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