JP5508828B2 - Optical element molding method and molding apparatus - Google Patents

Description

  The present invention relates to an optical element molding method and molding apparatus that heat soften an optical material such as a glass material under an inert atmosphere and perform pressure molding.

Conventionally, various optical element molding methods are known in which an optical material such as a glass material is softened by heating and press-molded with a molding die. As such an optical element molding method, for example, Patent Document 1 uses a molding block (mold assembly) in which a glass material that is an optical material and a molding die are integrally stored in a body mold. Two stages that preheat the glass, a pressure stage that allows pressure molding and pressure cooling of the optical material through the mold of the preheated molding block, and the entire pressure block that has been cooled and cooled to room temperature A cooling stage for cooling to the vicinity, and heating, pressurization, and cooling blocks that are vertically opposed to each of these stages are provided, and each of these stages and the blocks are arranged in the same chamber, A glass lens molding apparatus that heats, presses, and cools a molding block by repeatedly waiting the stage for a desired time and then moving the molding block to the next stage. There was method is described.
Such an optical element molding method is generally called a circulation molding method, but when the mold assembly is put into the molding machine, the atmosphere in the mold assembly is kept under an inert atmosphere in the molding machine. It takes time to naturally substitute by the diffusion phenomenon.
Therefore, before performing the molding process by the mold assembly, there is a reduced pressure gas replacement process in which the mold is accommodated in a mold accommodating portion which is a chamber capable of depressurization and the inside of the mold accommodating portion is depressurized and then purged with an inert gas. It may be done.
Moreover, in order to obtain a highly accurate optical element, it is required that the molding material to be molded and the molding surface of the mold be clean. For this reason, for example, in Patent Document 2, a sealed space is formed so as to cover a molding surface of a mold, cleaning gas is blown into the sealed space to clean the molding surface, and the cleaning gas in the sealed space is surrounded by the surroundings. There has been proposed a mold cleaning method for an optical glass element which is characterized in that the glass glass is discharged without being diffused.

Japanese Examined Patent Publication No. 7-64571 JP 2006-306643 A

However, the conventional optical element molding method and molding apparatus as described above have the following problems.
In the circulation molding method described in Patent Document 1, when performing a reduced pressure gas replacement step, a plurality of reduced pressure gas replacement steps are repeated by replacing a plurality of mold assemblies in the mold housing portion, so that it can be used for a long time. As a result, dust accumulates inside the mold housing.
The accumulated dust is scattered and penetrates into the mold assembly due to sudden pressure fluctuations during depressurization or gas introduction in the decompression gas replacement process and the flow of inert gas, and molding of the optical material or mold There exists a problem that it may adhere to a surface and may make a molded article into a poor appearance.
In addition to dust brought in from the outside together with the mold assembly, the dust accumulated when the mold assembly is replaced is rubbed on the bottom of the mold assembly when the mold assembly is transported in the molding apparatus. The generated dust and the dust generated in the movable part inside the molding apparatus are also included.
Therefore, even if the molding apparatus is installed in a clean environment such as a clean room, dust accumulation cannot be prevented. Therefore, the reduced-pressure gas replacement process in which dust easily enters the molding apparatus, particularly the mold assembly, on a regular basis. It is necessary to clean the inside of the mold housing part that performs the above.
However, in order to perform such cleaning, it is necessary to interrupt the molding operation, and there is a problem that productivity is reduced if frequent cleaning is performed.
Further, the technique described in Patent Document 2 is a mold cleaning method that is performed before the molding material is arranged on the mold surface to configure the mold assembly, and the molding material is arranged on the mold surface. There is a problem that it is impossible to prevent adhesion of dust entering after the mold assembly is formed.

  The present invention has been made in view of the above-described problems, and can be used to keep the inside of the mold housing in the reduced-pressure gas replacement step clean and to produce an optical element molded product with a high yield. It is an object to provide a method and a molding apparatus.

In order to solve the above problems, the optical element molding method of the present invention sequentially conveys a plurality of mold assemblies in which molding materials are arranged in a mold having a molding surface for molding an optical element, and is inactive. An optical element molding method in which an optical element is molded by heating and pressing in a gas atmosphere, and before performing the heating and pressing, the mold assembly is accommodated in a mold accommodating portion, and the mold Depressurization of depressurizing the accommodating portion and then introducing an inert gas through the introduction conduit into the mold accommodating portion to replace the atmosphere inside the mold accommodating portion and the mold assembly with the inert gas. A gas replacement step, and a dust removal step of removing dust from a portion that becomes an inner surface of the mold housing portion before housing the mold assembly in the mold housing portion, and the dust removing step In the reduced-pressure gas replacement step, the portion that becomes the inner surface of the mold housing portion Through kicking different spray conduit and the inlet conduit, said a method of performing dust removal by blowing inert gas.

  In the optical element molding method for removing dust by blowing inert gas through the blowing pipe of the present invention, the dust removing step sucks the inert gas blown through the blowing pipe from the suction pipe. Is preferred.

  Further, in the optical element molding method for sucking the inert gas from the suction pipe of the present invention, the strength of blowing the inert gas from the spray pipe and the strength of sucking the inert gas from the suction pipe It is preferable to periodically change at least one of them.

The optical element molding apparatus of the present invention sequentially conveys a plurality of mold assemblies in which molding materials are arranged in a mold having a molding surface for molding an optical element, and heats and presses it in an inert gas atmosphere. An optical element molding apparatus for molding an optical element, wherein a mold housing part that houses the mold assembly in a sealed state, a decompression part that decompresses the inside of the mold housing part, and the mold housing part In order to replace the atmosphere inside the gas with the inert gas, an introduction conduit for introducing the inert gas, and a dust removing unit that removes dust from a portion serving as an inner surface of the mold housing unit , The dust removing unit is configured to include a gas blowing unit that blows an inert gas through a blowing line different from the introduction line to a portion that is an inner surface of the mold housing part .

  Moreover, in the optical element molding apparatus provided with the gas spraying portion of the present invention, the dust removing portion sucks the inert gas sprayed through the spray conduit from the suction conduit to the outside of the mold housing portion. It is preferable to provide a part.

  Further, in the optical element molding apparatus including the gas suction unit according to the present invention, the spray pipe and the suction pipe are provided in the mold housing part, and the dust container is in a state where the mold housing part is sealed. It is preferable to allow removal.

  According to the optical element molding method and molding apparatus of the present invention, it is possible to remove dust from the inner surface of the mold housing portion before housing the mold assembly in the mold housing portion. The inside of the mold housing part in the replacement process can be kept clean, and the optical element molded product can be produced with a high yield.

It is the typical partial sectional view of front view which shows schematic structure of the optical element shaping | molding apparatus which concerns on the 1st Embodiment of this invention, and partial sectional drawing of planar view. It is the typical fragmentary sectional view which looked at the gas replacement chamber of the optical element shaping | molding apparatus which concerns on the 1st Embodiment of this invention from the conveyance direction near side. It is process explanatory drawing of the dust removal process of the optical element shaping | molding method which concerns on the 1st Embodiment of this invention. It is process explanatory drawing of the pressure reduction gas substitution process of the optical element shaping | molding method which concerns on the 1st Embodiment of this invention. It is a typical side view of the dust removal part which concerns on the modification (1st and 2nd modification) of the optical element shaping | molding apparatus which concerns on the 1st Embodiment of this invention. It is the typical fragmentary sectional view which looked at the gas replacement chamber of the optical element shaping | molding apparatus which concerns on the 2nd Embodiment of this invention from the conveyance direction near side. It is the typical fragmentary sectional view which looked at the gas substitution chamber of the optical element shaping | molding apparatus which concerns on the 3rd Embodiment of this invention from the conveyance direction near side. It is typical AA sectional drawing in FIG. It is a timing chart of gas spraying and gas suction in an optical element fabrication method concerning a 3rd embodiment of the present invention, and a timing chart of the modification (the 3rd and 4th modification). It is a timing chart of gas spraying and gas suction in the optical element shaping method concerning the modification (5th modification) of the 3rd embodiment of the present invention.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In all the drawings, even if the embodiments are different, the same or corresponding members are denoted by the same reference numerals, and common description is omitted.

[First Embodiment]
An optical element molding apparatus according to the first embodiment of the present invention will be described.
Fig.1 (a) is typical fragmentary sectional view of the front view which shows schematic structure of the optical element shaping | molding apparatus which concerns on the 1st Embodiment of this invention. FIG.1 (b) is a fragmentary sectional view of planar view in Fig.1 (a). FIG. 2 is a schematic partial cross-sectional view of the gas replacement chamber of the optical element molding apparatus according to the first embodiment of the present invention as viewed from the front side in the transport direction.
In addition, since each drawing is a schematic diagram, the shape and dimension are exaggerated (the following drawings are also the same).

The optical element molding apparatus 50 according to the present embodiment sequentially conveys a plurality of mold assemblies in which molding materials are arranged in a mold having a molding surface for molding an optical element, and is heated and pressed in an inert gas atmosphere. Thus, the optical element is formed.
As shown in FIGS. 1A and 1B, the schematic configuration of the optical element molding apparatus 50 includes an input chamber 51, a gas replacement chamber 52, a molding chamber 53, and a discharge chamber 54 arranged in this order.
In the optical element molding apparatus 50, an optical element molding method of the present invention, which will be described later, in the process of transporting the mold assembly 60 thrown into the input chamber 51 from the input chamber 51 toward the discharge chamber 54 along the transport direction M. These steps can be performed sequentially.
Further, an apparatus control unit 55 for controlling the operation of each process is connected to each of these chambers by wiring (not shown). The apparatus configuration of the apparatus control unit 55 of the present embodiment includes a computer having a CPU, a memory, an input / output interface, an external storage device, and the like so that each control operation can be realized by executing an appropriate control program. It has become.

As an example of the mold assembly 60 used in the optical element molding apparatus 50, as shown in FIGS. 1 (a) and 4, a molding surface 61a for molding one element surface of the optical element is provided at the upper end, and the lower end. A lower mold 61 (mold) having a flange portion on the side, and an upper mold 62 (mold) having a molding surface 62a for molding the other element surface of the optical element on the lower end portion and having a flange portion on the upper end side; The side surfaces of the lower die 61 and the upper die 62 are slidably fitted and sandwiched between the flange portions and sandwiched between the molding surfaces 61a and 62a. A configuration composed of the molding material 64 arranged can be employed.
In FIGS. 1A and 4, the molding surfaces 61 a and 62 a are depicted as concave spherical shapes corresponding to the case where the optical element is a biconvex lens, for example, but various shapes may be used depending on the shape of the optical element. The surface shape can be adopted.
As the molding material 64, an appropriate glass glass material for molding an optical element can be adopted.

The input chamber 51 is for receiving the mold assembly 60 from the outside of the optical element molding apparatus 50 and delivering the mold assembly 60 to the gas replacement chamber 52, and controls the apparatus on the side surface of the rectangular parallelepiped chamber 51a. The shutter 1 whose opening / closing operation is controlled by the unit 55 is provided, and the stage 2 and the transport mechanism 3 are provided inside the chamber 51a.
The shutter 1 forms an opening larger than the mold assembly 60 when opened, and can shut the chamber 51a from the outside airtight when closed.
The stage 2 is a low friction plate-like member on which the mold assembly 60 inserted through the opening of the shutter 1 is slidably mounted in the horizontal direction.
The transport mechanism 3 moves between the mold assembly 60 placed on the stage 2 in the transport direction M under the control of the device control unit 55 and is provided between the input chamber 51 and the gas replacement chamber 52 and controls the device. When the shutter 4 whose opening / closing operation is controlled by the portion 55 is opened, the mold assembly 60 is moved to the gas replacement chamber 52.
As shown in FIG. 1B, the structure of the transfer mechanism 3 includes a telescopic arm 3b provided between the input chamber 51 and the gas replacement chamber 52 along the transfer direction M, and a mold assembly. In order to press the side surface of 60 in the transport direction M, a transport head 3a provided at the tip of the telescopic arm 3b is provided.

  The gas replacement chamber 52 is used for performing a reduced pressure gas replacement process, which will be described later, on the mold assembly 60 delivered from the input chamber 51. As shown in FIG. A port 8, a movable chamber 6, an inert gas introduction line 9 (introduction line), a dust removing unit 7, and a transport mechanism 17 are provided.

The stage 5 is a plate-like member having a low friction stage upper surface 5 a on which the mold assembly 60 conveyed through the opening of the shutter 4 is slidably mounted in the horizontal direction toward the adjacent molding chamber 53. The stage upper surface 5a of the present embodiment is configured from a plane.
In order to smoothly slide the mold assembly 60, the stage upper surface 5a has, for example, a large number of protrusions such as a convex spherical shape whose upper end is aligned with a horizontal plane, and comb teeth extended in the transport direction M. An uneven structure such as a shape may be provided on the surface. However, the surface region 5b composed of a region in contact with a seal member 6e of the movable chamber 6 described later and the inner side thereof can be in close contact with an elastic member such as a seal member 6e and a cleaning roller 7a described later even if an uneven structure is provided. A fine uneven surface.

The inert gas inlet 8 introduces an inert gas G into the chamber 52a to keep the inside of the chamber 52a at a positive pressure. Thereby, even when the shutter 4 is opened, the atmospheric atmosphere remaining in the charging chamber 51 is difficult to enter the chamber 52a.
As the inert gas G, an appropriate inert gas can be adopted as long as it is an inert gas that does not affect the molding by chemically reacting with the molding material 64. In the present embodiment, nitrogen gas (N ₂ ) is employed. Further, the inert gas G is supplied after being cleaned from dust that may affect the molding of the optical element.
The inert gas inlet 8 of the present embodiment is provided so as to open on the inner side in the ceiling portion of the chamber 52a, and is connected to one end portion of the conduit 8a outside the chamber 52a.
The other end of the pipe line 8a is connected to an inert gas source 11 that supplies an inert gas G through a regulating valve 10 for keeping the inside of the chamber 52a at a positive pressure with respect to the charging chamber 51.

The movable chamber 6 is for accommodating the mold assembly 60 transported on the stage upper surface 5a in a sealed state between the stage upper surface 5a. In this embodiment, the central axis is arranged in the vertical direction. It consists of a bottomed cylindrical member that opens downward.
Therefore, a cylindrical shape having a size capable of accommodating the mold assembly 60 at an interval from the inner side surface 6a and the ceiling surface 6b inside the movable chamber 6 constituted by the inner side surface 6a and the ceiling surface 6b of the movable chamber 6. A space is formed.
A flange portion surrounding the opening is provided at a lower end portion of the movable chamber 6, and a lower surface 6 d including the flange portion is formed as a flat surface that can come into contact with the stage upper surface 5 a. Further, an annular groove is formed along the circumferential direction on the lower surface 6d, and a seal member 6e made of an elastic member such as an O-ring is slightly formed on the inner side of the groove from the groove to the lower surface 6d side. It is attached to protrude.
As a result, when the lower surface 6d and the stage upper surface 5a are brought into contact with each other, the seal member 6e is in close contact with the stage upper surface 5a in a compressed state between the stage upper surface 5a and the concave groove of the movable chamber 6. 6 can be sealed.

On the ceiling of the chamber 52 a above the movable chamber 6, an elevating arm 14, which is a moving mechanism for moving the movable chamber 6 up and down above the stage 5 under the control of the apparatus control unit 55, is provided.
The lifting arm 14 of the present embodiment employs a configuration in which the lower end portion is fixed to the upper surface 6c of the movable chamber 6 and the length in the vertical direction is expanded and contracted.
The raising / lowering range of the movable chamber 6 by the raising / lowering arm 14 is set so that the lower surface 6d of the movable chamber 6 and the stage upper surface 5a contact | abut in the lowest state. Further, at the time of ascent, it is set so that at least the lower surface 6 d of the movable chamber 6 can be held at a position higher than the upper end surface of the mold assembly 60 transported onto the stage 5.
For this reason, the movable chamber 6 lowered so that the lower surface 6d contacts the stage upper surface 5a is brought into contact with the stage upper surface 5a in a state where the seal member 6e is pressed against the outer peripheral portion of the surface region 5b. For this reason, the movable chamber 6 and the stage 5 constitute a mold housing part that houses the mold assembly 60 in a sealed state.
Further, the inner side surface 6a, the ceiling surface 6b, and the surface region 5b of the movable chamber 6 are portions that become the inner surface of the mold housing portion.

Further, an inert gas introduction line 9 is provided through the central portion of the upper surface 6 c of the movable chamber 6, and an opening on the lower end side of the inert gas introduction line 9 is projected to the inside of the movable chamber 6. ing.
The inert gas introduction line 9 is for introducing the inert gas G into the sealed space formed by the movable chamber 6 and the stage 5.
In the present embodiment, it is provided so as to penetrate the ceiling portion of the chamber 52a, the upper surface 6c of the movable chamber 6, and the ceiling surface 6b. And the edge part inside the movable chamber 6 of the inert gas introduction pipe line 9 is opened downward in the center part of the ceiling surface 6b.
Further, an intermediate portion of the inert gas introduction conduit 9 extending outside the movable chamber 6 and disposed inside the chamber 52a is the upper surface 6c of the movable chamber 6 and the ceiling of the chamber 52a when the movable chamber 6 is lowered. It has a length that is equal to or greater than the distance between the parts, or is configured to extend or retract in the vertical direction in accordance with the up and down movement of the movable chamber 6. Thereby, the movable chamber 6 can be moved up and down smoothly in a state where the inert gas introduction conduit 9 is connected.

  In addition, the inert gas introduction pipe line 9 extending to the outside above the chamber 52 a introduces the inert gas G into the movable chamber 6 via the switching valve 12 whose opening and closing is controlled by the device control unit 55. For this purpose, the pipe 9a is connected to an inert gas source 11 and the pipe 9b is connected to a vacuum pump 13 (decompression unit) to depressurize the movable chamber 6.

  The dust removing unit 7 removes dust from the inner surface of the mold housing unit. In this embodiment, the dust removing unit 7 is disposed on the side of the stage 5 as shown in FIGS. 1B and 2. The dust removing unit main body 7c, the movable arm 7b that is extendable in the direction orthogonal to the conveying direction M from the side surface on the stage 5 side of the dust removing unit main body 7c, and the tip of the movable arm 7b are rotatably held. , And a cleaning roller 7a disposed so that the axial direction is along the conveying direction M.

Inside the dust removing unit main body 7c, there is provided a drive mechanism that is connected to the device control unit 55 through a wiring (not shown) and that expands and contracts the movable arm 7b under the control of the device control unit 55.
The movable arm 7b enters from above one side surface of the stage 5 to above the stage upper surface 5a, and can move forward and backward in the horizontal direction to the vicinity of the other side surface.
The arrangement height of the movable arm 7b is set to a height at which the cleaning roller 7a provided at the tip of the movable arm 7b can roll while contacting the stage upper surface 5a.

The cleaning roller 7a is a member that removes dust accumulated on the stage upper surface 5a from at least the surface region 5b by rolling on and retracting from the stage upper surface 5a.
For this reason, the roller length and the advance / retreat range of the cleaning roller 7a are set so that the cleaning roller 7a can roll over a range covering at least the surface region 5b.
The advance / retreat range of the cleaning roller 7 a may include the range of the stage upper surface 5 a corresponding to the transfer path when the mold assembly 60 is transferred from the charging chamber 51 to the gas replacement chamber 52. In this case, since the dust on the transfer path is also removed before the mold assembly 60 is transferred to the gas replacement chamber 52, even if dust accumulates on the transfer path, Can be prevented from being pushed out and moved to the surface region 5b.

As the material of the cleaning roller 7a, an appropriate material can be adopted as long as dust on the surface region 5b can be removed.
In this embodiment, a silicon rubber roller having an adhesive layer on the surface is employed. Other suitable configurations include a charging roller charged with static electricity, a charging brush roller, and the like.
In addition, the cleaning roller 7a may be provided with an uneven surface or a groove shape that changes unevenness in the circumferential direction of the roller so that dust can be easily scraped off.

The transport mechanism 17 transports the mold assembly 60 transported from the loading chamber 51 onto the stage 5 into the surface region 5b based on the control of the device control unit 55, and completes the reduced pressure gas replacement process. The mold assembly 60 is conveyed into the molding chamber 53 through the opening of the shutter 20 having the same configuration as the shutter 4 provided at the boundary with the molding chamber 53.
The transport mechanism 17 can employ the same means as the means for transporting the mold assembly in the conventional optical element molding apparatus. In the present embodiment, as an example, in the space above the dust removing unit 7, the mold assembly 60 moves in the conveyance direction M while moving forward and backward in the direction orthogonal to the conveyance direction M and pushing the side surface of the mold assembly 60. An L-shaped transport head 17a is provided.

The molding chamber 53 performs a molding process of the optical element using the mold assembly 60 under an inert gas G atmosphere.
That is, the molding chamber 53 is always filled with the inert gas G by a conduit (not shown) connected to the inert gas source 11, and is carried in through the shutter 20 by the transport mechanism 17 under the control of the device control unit 55. The formed mold assembly 60 is heated to soften the molding material 64 in the mold assembly 60. In this state, the upper mold 62 is pressed against the lower mold 61 from the upper side to be softened. The molding material 64 is pressed along the molding surfaces 61a and 62a. After the shapes of the molding surfaces 61a and 62a are transferred, the molding material 64 is cooled and solidified.

The schematic apparatus configuration of the molding chamber 53 according to the present embodiment is to form a transport path for sequentially transporting the mold assembly 60 along the transport direction M and to heat the mold assembly 60 transferred as necessary. The mold assembly 60 is held between the molding stage 21 to be cooled and the molding stage 21 so as to be able to advance and retreat, and the mold assembly 60 is heated or cooled as necessary. A pressure plate 22 and a pressure cylinder 24 for applying pressure to press the mold assembly 60 as necessary by moving the pressure plate 22 up and down are provided. A plurality of pressure cylinders 24 are arranged along the conveyance direction M. Yes.
Further, inside the molding stage 21 and the pressure plate 22, a temperature adjusting mechanism such as a heater or a cooling channel (not shown) is provided.

Although not particularly illustrated, a transport mechanism for sequentially transporting the mold assembly 60 transported to the molding chamber 53 to the adjacent molding stages 21 is provided on the side of each molding stage 21 in the molding chamber 53. Is provided. Similarly to the transport mechanism 17, this transport mechanism can employ a transport mechanism with an appropriate configuration used in a conventional optical element molding apparatus.
A shutter 23 having the same configuration as the shutter 4 is provided at the boundary with the discharge chamber 54 at the end of the molding chamber 53 in the transport direction M. Thus, the mold assembly 60 transported to the molding stage 21 adjacent to the shutter 23 can be transported to the discharge chamber 54 through the opening of the shutter 23 by a transport mechanism (not shown).

  The discharge chamber 54 is for taking out the mold assembly 60 that has been subjected to the molding process to the outside of the optical element molding apparatus 50 while maintaining the inert gas atmosphere of the molding chamber 53. A stage 26 movably mounted, an inert gas introduction pipe (not shown), and a shutter 25 having the same configuration as the shutter 4 for taking out the mold assembly 60 to the outside of the apparatus are provided.

Next, the operation of the optical element molding apparatus 50 of this embodiment will be described together with the optical element molding method of this embodiment.
FIG. 3 is a process explanatory diagram of a dust removing process of the optical element molding method according to the first embodiment of the present invention. FIG. 4 is a process explanatory diagram of a reduced-pressure gas replacement process of the optical element molding method according to the first embodiment of the present invention.

In the optical element molding method according to the present embodiment, the mold assembly 60 put into the insertion chamber 51 of the optical element molding apparatus 50 is transferred to the gas replacement chamber 52 to perform the dust removal process. Next, a reduced pressure gas replacement process is performed in the gas replacement chamber 52, and then the mold assembly 60 is transferred to the molding chamber 53 and the molding process is sequentially performed on the plurality of molding stages 21.
For this reason, in the optical element molding apparatus 50, when the power is turned on, the shutters 4, 20, and 23 are closed by the apparatus control unit 55, and thereby the inside of the gas replacement chamber 52 and the molding chamber 53 in which the closed space is configured. Replace with inert gas G atmosphere. At this time, the inert gas G from the inert gas source 11 is introduced through the inert gas introduction port 8 in the gas replacement chamber 52 and through a conduit (not shown) in the molding chamber 53. These inert gases G are always supplied even during the following operations.

When the preparation for molding is completed, the operator opens the shutter 1 and, among the preassembled mold assemblies 60, puts the mold assembly 60 to be molded first onto the stage 2 in the charging chamber 51, Shutter 1 is closed.
Next, the device control unit 55 opens the shutter 4 to connect the charging chamber 51 and the gas replacement chamber 52.
In the gas replacement chamber 52, a dust removal process is performed.

The dust removing step is a step of removing dust inside the mold housing portion before housing the mold assembly 60 in the mold housing portion.
In the present embodiment, as shown in FIG. 3, the movable arm 6 is raised by contracting the elevating arm 14 under the control of the device control unit 55. Next, the apparatus control unit 55 performs an operation of controlling the dust removing unit body 7c of the dust removing unit 7 to expand and contract the movable arm 7b and roll the cleaning roller 7a on the stage upper surface 5a.
The rolling of the cleaning roller 7a reciprocates the surface area 5b by a predetermined number of one or more reciprocations. After the predetermined number of reciprocations, the movable arm 7b is contracted, and the cleaning roller 7a is placed on the side of the stage 5 as shown in FIG.
As a result, the dust adhering to the surface region 5b is attracted to the surface of the cleaning roller 7a along with the rolling of the cleaning roller 7a, and the dust on the surface region 5b included in the rolling range of the cleaning roller 7a is removed. The
Thus, the dust removal process is completed.

Next, the device control unit 55 controls the transport mechanism 3 to extend the telescopic arm 3b in the transport direction M. Thereby, the side surface of the mold assembly 60 is pressed by the transport head 3a provided at the tip of the telescopic arm 3b. For this reason, the mold assembly 60 is slid and moved on the stage 2 and is conveyed onto the stage 5 through the opening of the shutter 4.
When the mold assembly 60 is positioned approximately at the center of the surface area 5 b of the stage 5, the transfer mechanism 3 stops the extension of the extendable arm 3 b, shortens the extendable arm 3 b, and retracts the transfer head 3 a into the input chamber 51. Let
Thereafter, the device control unit 55 closes the shutter 4.

Next, a reduced pressure gas replacement step is performed in the gas replacement chamber 52.
The depressurized gas replacement step is a step performed before performing the heating and pressing in the molding step. The mold assembly 60 is housed inside the mold housing portion, the inside of the mold housing portion is decompressed, and then the inside of the mold housing portion is stored. In this step, the inert gas G is introduced through the inert gas inlet 8 to replace the atmosphere inside the mold housing part and the mold assembly 60 with the inert gas G.
In the present embodiment, as shown in FIG. 4, the device controller 55 controls the elevating arm 14 to lower the movable chamber 6 and bring the lower surface 6d into contact with the stage upper surface 5a. As a result, the seal member 6e provided on the lower surface 6d is in close contact with the surface region 5b, and the mold assembly 60 moved onto the surface region 5b is placed in a sealed space formed by the stage 5 and the movable chamber 6. Be contained.

Next, the device control unit 55 controls the switching valve 12 to close the pipe line 9a, connect the inert gas introduction pipe line 9 and the pipe line 9b, and drive the vacuum pump 13. Thereby, the atmosphere in the movable chamber 6 is exhausted and depressurized to a vacuum state.
As a result, the air remaining in the mold assembly 60 is also exhausted through the gap in the mold assembly 60.

When the inside of the movable chamber 6 is depressurized to a vacuum state, the device control unit 55 controls the switching valve 12 to close the conduit 9b and connect the inert gas introduction conduit 9 and the inert gas source 11 to the tube. The road 9a is connected.
As a result, the inert gas G is introduced into the movable chamber 6 through the inert gas introduction conduit 9. The inert gas G is filled in the gaps in the movable chamber 6 and the mold assembly 60.
At this time, since the inside of the movable chamber 6 has a low pressure at the initial stage of introduction, the inert gas G is injected downward from the inert gas introduction conduit 9. If dust accumulates on the surface region 5b, there is a risk that the dust will rise by this jet and enter the mold assembly 60. In this embodiment, however, Since the dust on the surface region 5b is removed by performing the removing step, it is possible to prevent the dust from flying up.
When the pressure of the inert gas G in the movable chamber 6 becomes the same as the gas pressure of the inert gas G that is constantly supplied through the inert gas inlet 8, the reduced pressure gas replacement process is terminated.

  Even if the dust in the surface region 5b is not completely removed in the dust removing step, the dust remaining on the surface region 5b after the predetermined number of rollings of the cleaning roller 7a is It is dust that is firmly adhered to the stage upper surface 5a. For this reason, since it does not rise easily with the jet flow temporarily injected from the inert gas introduction pipe line 9, it is possible to remarkably reduce dust scattering compared to the case where the dust removal step is not performed.

Next, the device controller 55 controls the elevating arm 14 to raise the movable chamber 6 higher than the upper end of the mold assembly 60 and open the shutter 20.
Further, the device control unit 55 controls the transport mechanism 17 to advance the transport head 17a to the side of the mold assembly 60 opposite to the transport direction M, and push the mold assembly 60 in the transport direction M. . Thereby, the mold assembly 60 is conveyed to the molding stage 21 in the molding chamber 53.
When the mold assembly 60 is transported to the molding chamber 53, the apparatus controller 55 closes the shutter 20, retracts the transport head 17a from the stage 5, and before the dust removal process is performed in the gas replacement chamber 52. Return to the state.
As a result, the gas replacement chamber 52 is in a state where the dust removal step and the reduced pressure gas replacement step can be performed in the same manner as described above with respect to the mold assembly 60 to be input into the input chamber 51 next.

The mold assembly 60 transported to the molding chamber 53 is sequentially transported onto the molding stage 21 by a transport mechanism (not shown) provided in the molding chamber 53, and the lower mold 61 is placed in an inert gas G atmosphere. In addition, a known molding process for molding the optical element by heating and pressing the molding material 64 sandwiched between the upper mold 62 and the mold assembly 60 carried into the molding chamber 53 in the order of loading. It will be done in parallel, out of order.
That is, on each molding stage 21, the pressure plate 22 is moved up and down by the pressure cylinder 24, and the mold assembly 60 moved onto the molding stage 21 is sandwiched between the molding stage 21 and the pressure plate 22 to be constant. The pressure can be applied and held, or the pressure can be increased.
Accordingly, the lower mold 61 and the upper mold 62 are heated to raise the temperature of the molding material 64 and soften the molding material 64, and the mold assembly 60 is softened by applying pressure from above and below. Press molding process of press molding the molding material 64 along the molding surfaces 61a and 62a, and a cooling removal process of cooling until the molded molding material 64 sandwiched between the lower mold 61 and the upper mold 62 is solidified. Are sequentially performed along the transport path.
These steps are set so as to be divided into a plurality of molding stages 21 as necessary so that the conveyance tact of the mold assembly 60 is as short as possible.

In this way, when the mold assembly 60 is transported to the molding stage 21 adjacent to the shutter 25, all molding processes for the mold assembly 60 are completed.
When the mold assembly 60 reaches the molding stage 21, the apparatus control unit 55 opens the shutter 23 and moves the mold assembly 60 that has completed the molding process to the stage 26 in the discharge chamber 54. Then, the shutter 23 is closed.
At this time, the shutter 25 of the discharge chamber 54 is closed, and the inert gas G is filled in the discharge chamber 54 before the shutter 23 is opened.
Next, the shutter 25 is opened, the mold assembly 60 on the stage 26 is taken out from the discharge chamber 54 and allowed to cool to an appropriate temperature in an appropriate storage place, and then the mold assembly 60 is disassembled. Then, by removing the molded optical element, the optical element molding method of this embodiment is completed.
In addition, without waiting for completion of the optical element by one mold assembly 60, the mold assembly 60 is sequentially inserted into the input chamber 51 as soon as the input chamber 51 becomes empty, and the above steps are performed in parallel. Therefore, the optical element molding apparatus 50 sequentially molds a plurality of optical elements.

In the optical element molding method of the present embodiment, since the dust removing process is performed on the surface area 5b constituting the inner surface of the mold housing portion before the reduced pressure gas replacement process, the dust accumulated in the surface area 5b in the reduced pressure gas replacement process. Can be prevented from being scattered and adhering to the inside of the mold assembly 60. For this reason, the inside of the mold accommodating portion in the reduced pressure gas replacement step can be kept clean, and an optical element molded product can be produced with a high yield.
Further, in the optical element molding method of the present embodiment, the reduced pressure gas replacement step is performed a plurality of times, and the dust removal step is always performed before each reduced pressure gas replacement step. For this reason, when the mold assembly 60 is repeatedly conveyed to the gas replacement chamber 52, dust adheres to the surface of the mold assembly 60 or the like, or between the mold assembly 60 and the stage 5. Even if dust is generated due to such friction, the dust is removed by the next dust removing step, so that dust does not accumulate over time on the surface region 5b. Therefore, it is possible to prevent the yield of the optical element molded product from deteriorating with time.

Further, the dust removing unit 7 of the optical element molding apparatus 50 of the present embodiment is built in the gas replacement chamber 52 and can automatically remove dust under an inert gas G atmosphere under the control of the device control unit 55. . For this reason, it is not necessary to stop operation | movement of the optical element shaping | molding apparatus 50 like the case where the inside of the gas replacement chamber 52 is cleaned manually.
When an operator enters and cleans the inside of the gas replacement chamber 52, it is necessary to return the gas replacement chamber 52 to the atmosphere and stop the heating of the molding chamber 53 to lower the temperature in the gas replacement chamber 52 to room temperature. There is. Therefore, the down time of the optical element molding apparatus 50 is increased, and the productivity of the optical element molded product is significantly reduced.
On the other hand, in this embodiment, only a slight time for rolling the cleaning roller 7a on the surface region 5b is increased, and the downtime for changing the temperature and atmosphere of the optical element molding apparatus 50 is much longer than this. Therefore, productivity can be improved as compared with the case where an operator enters and cleans the apparatus.

Next, a modification of this embodiment will be described.
5A and 5B are schematic side views of a dust removing unit according to modified examples (first and second modified examples) of the optical element molding apparatus according to the first embodiment of the present invention. .

[First Modification]
As shown in FIG. 5A, the dust removing unit 7A of the first modification of the present embodiment includes a cleaning blade 15 instead of the cleaning roller 7a of the dust removing unit 7 of the first embodiment. It is. As with the dust removing unit 7, the dust removing unit 7A can be suitably used for the optical element molding apparatus 50 according to the first embodiment.
The cleaning blade 15 includes an elongated plate-like elastic member having the same length as the cleaning roller 7a. As a material of the cleaning blade 15, for example, synthetic rubber or the like can be used.
The cleaning blade 15 has a longitudinal direction extending in the depth direction of the paper surface of FIG. 5A along the transport direction M, and an end portion in the short direction in a linear or elongated strip shape along the stage upper surface 5a and the transport direction M. It is fixed to the tip of the movable arm 7b so as to be in close contact.
The cleaning blade 15 of the present embodiment is attached to the dust removing unit body 7c side with respect to a plane including the normal line of the stage upper surface 5a and the transport direction M.
When the deflection deformation along the longitudinal direction becomes too large due to the flexibility of the cleaning blade 15, the movable arm 7b is connected to the movable arm 7b via a reinforcing member such as a metal plate in order to maintain the straightness in the longitudinal direction. It may be fixed.

According to this modification, the cleaning blade 15 is in close contact with the stage upper surface 5a in a linear or elongated strip shape, and is provided so as to be slidable in a direction perpendicular to the transport direction M by moving the movable arm 7b back and forth. Yes.
Therefore, the dust attached to the surface of the surface region 5b by the cleaning blade 15 can be scraped off from the surface region 5b by extending and retracting the movable arm 7b and moving the cleaning blade 15 back and forth. In the present embodiment, dust can be scraped particularly efficiently in the direction in which the movable arm 7b extends from the inclination direction of the cleaning blade 15, and the dust can be moved forward in the extending direction.
The inclination direction of the cleaning blade 15 is an example, and is not limited to such an inclination direction. For example, if the cleaning blade 15 is inclined in the opposite direction, it is possible to scrape dust particularly efficiently in the direction in which the movable arm 7b is shortened and move the dust to the shortening direction side.
Further, if the cleaning blade 15 is provided perpendicular to the stage upper surface 5a, the cleaning blade 15 can be bent in the direction opposite to the extending direction and the shortening direction in accordance with the expansion and contraction of the movable arm 7b to scrape dust.

According to this modification, by moving the movable arm 7b back and forth, the dust on the surface region 5b can be moved to the side stage upper surface 5a with respect to the transport direction M and removed from the surface region 5b. For this reason, in the reduced pressure gas replacement step, the dust that has been on the surface region 5b has been moved to the outside of the surface region 5b, so that it is scattered inside the movable chamber 6 and into the gap in the mold assembly 60. There is no invasion.
In this way, when the molding of the mold assembly 60 is continued, dust gradually accumulates outside the surface region 5b on the stage upper surface 5a. However, these dusts are outside the movable chamber 6 that is in close contact with the stage upper surface 5 a, and are not scattered by the air flow generated in the reduced pressure gas replacement process or enter the mold assembly 60. Therefore, since it does not affect the yield of the optical elements, it may be removed at the time of periodic cleaning performed by stopping the operation of the optical element molding apparatus 50 after the appropriate number of moldings are completed.

  According to this modification, since the dust is moved and removed on the stage upper surface 5a using the cleaning blade 15, the dust is adsorbed on the surface of the cleaning roller 7a to remove the dust as compared with the first embodiment. Thus, it is easy to maintain the dust removal performance of the cleaning blade 15 over a long period of time. In addition, maintenance for maintaining the dust removal performance is facilitated.

[Second Modification]
As shown in FIG. 5B, the dust removing unit 7B of the second modified example of the present embodiment includes a cleaning pad 16 instead of the cleaning roller 7a of the dust removing unit 7 of the first embodiment. It is. As with the dust removing unit 7, the dust removing unit 7B can be suitably used for the optical element molding apparatus 50 according to the first embodiment.

The cleaning pad 16 has both ends fixed to the tip of the movable arm 7b, an elongated plate-like support member 16c having the same length as the cleaning roller 7a, and a lower end of the support member 16c having a circular arc shape in the cross section in the transport direction M. And a cleaning member 16a pastably attached to the lower end surface of the head portion 16b.
The mounting position of the cleaning member 16a in the vertical direction is such that when the cleaning member 16a is moved onto the stage 5 by the movable arm 7b, the lower end portion of the cleaning member 16a contacts the stage upper surface 5a and can slide on the stage upper surface 5a. The positional relationship is set so as to be pressed against the stage upper surface 5a.
The material of the cleaning member 16a is not particularly limited as long as it is a material that can wipe off dust on the stage upper surface 5a. For example, a cloth woven with fine fibers, a cloth with a raised surface, a fine nonwoven fabric, a flexible porous member formed of a synthetic resin, synthetic rubber, or the like can be used.

According to this modification, the dust attached to the surface of the surface region 5b by the cleaning pad 16 can be scraped off from the surface region 5b by extending and retracting the movable arm 7b and moving the cleaning pad 16 back and forth.
At least a part of the dust removed is adsorbed inside the cleaning member 16a. The dust that cannot be adsorbed is moved onto the stage upper surface 5a on the side with respect to the transport direction M.
In this way, dust can be removed from the surface region 5b. For this reason, as in the first modified example, in the reduced pressure gas replacement step, the dust that has been on the surface region 5b has been moved to the outside of the surface region 5b, and thus scattered inside the movable chamber 6, There is no entry into the gap in the mold assembly 60.

According to the present modification, the dust is moved and removed on the stage upper surface 5a using the cleaning pad 16, so that even dust having strong adhesion to the stage upper surface 5a can be efficiently removed.
The dust removing performance of the dust removing unit 7B can be maintained by appropriately replacing the cleaning member 16a whose dust removing performance is reduced due to the increased amount of adsorbed dust.

[Second Embodiment]
Next, an optical element molding apparatus according to the second embodiment of the present invention will be described.
FIG. 6 is a schematic partial cross-sectional view of the gas replacement chamber of the optical element molding apparatus according to the second embodiment of the present invention as viewed from the front side in the transport direction.

  As shown in FIG. 1A, the optical element molding apparatus 50A of this embodiment includes a gas replacement chamber 52A instead of the gas replacement chamber 52 of the optical element molding apparatus 50 of the first embodiment. is there. Hereinafter, a description will be given centering on differences from the first embodiment.

As shown in FIG. 6, the gas replacement chamber 52 </ b> A includes a dust removal unit 30 instead of the dust removal unit 7 of the gas replacement chamber 52 of the first embodiment. In FIG. 6, the transport mechanism 17 is not shown for easy viewing.
The dust removing unit 30 includes an inert gas pumping unit 31 that delivers clean inert gas G supplied from an unillustrated inert gas source at a high pressure, and an inert gas pumping unit connected to the inert gas pumping unit 31. The inert gas G supplied from 31 is injected from the injection port 32a on the front end side and sprayed onto the stage upper surface 5a, and the inert gas G in the chamber 52a is turned into the inert gas G. A suction duct 35 (suction conduit) that sucks together with the dust that has been entrained.
As the configuration of the inert gas pumping unit 31, for example, a configuration including a compressor and a flow rate adjustment valve controlled by the device control unit 55 can be adopted.

The ejection nozzle 32 is disposed above one side of the stage 5 by a nozzle movement holding unit 33 provided on one side of the stage 5 with respect to the transport direction M (for example, the right side when facing the transport direction M). Is retained.
The posture of the injection nozzle 32 is such that the injection port 32a is directed to the other side and the injection direction is directed obliquely downward.
As the size of the injection port 32a of the injection nozzle 32, an appropriate size can be adopted as long as the flow rate and flow rate of the inert gas G can be ejected from the stage upper surface 5a.
For example, when the diameter of the injection port 32a of the injection nozzle 32 is about 5 mm, the injection pressure of the inert gas G is preferably atmospheric pressure + 0.3 MPa to atmospheric pressure + 0.5 MPa.

The nozzle movement holding unit 33 holds the injection nozzle 32 so as to be movable in order to spray the inert gas G injected from the injection nozzle 32 over at least the entire surface region 5b.
In the present embodiment, the holding table moving unit 33b arranged to extend along the transfer direction M on the bottom surface of the chamber 52a, and the injection nozzle 32 are held, and the holding table moving unit 33b is moved back and forth along the transfer direction M. The structure which consists of the nozzle holding stand 33a to employ | adopt is adopted.

The suction duct 35 is provided on the side surface of the chamber 52a on the other side of the stage 5, and the suction port 35a for sucking the inert gas G is ejected in a range from the side of the stage upper surface 5a to the upper side. It is installed in a direction facing the nozzle 32.
The opening width of the suction port 35a in the present embodiment in the direction along the transport direction M is opened to be slightly wider than the width of the surface region 5b along the transport direction M.
The suction duct 35 is connected to a suction pump 37 that sucks the inert gas G from the suction duct 35 via a pipe line 36a on the outside of the chamber 52a.
Connected to the exhaust side of the suction pump 37 is a dust collector 38 for collecting and removing dust contained in the suctioned inert gas G.
As the dust collector 38, a filter for collecting dust may be provided, or an electric dust collector or the like may be used, for example.
A pipe line 36 b connected to the exhaust side of the dust collector 38 is opened in a chamber 52 a on one side of the stage 5.
Thus, the suction duct 35 and the pipes 36a and 36b constitute a suction pipe for circulating the inert gas G in the gas replacement chamber 52 outside the chamber 52a.

In the present embodiment, the inert gas pressure feeding unit 31 and the nozzle movement holding unit 33 spray the inert gas G through the injection nozzles 32 different from the inert gas introduction pipe line 9 onto the portion that becomes the inner surface of the mold housing unit. The gas spraying part is constituted.
The pipe 36a and the suction pump 37 constitute a gas suction part that sucks the inert gas G blown through the injection nozzle 32 from the suction duct 35 to the outside of the mold housing part.

Next, the operation of the optical element molding apparatus 50A of the present embodiment will be described focusing on the optical element molding method of the present embodiment.
The optical element forming method of the present embodiment includes a dust removing process, a reduced-pressure gas replacement process, and a molding process, as in the first embodiment. However, the present embodiment is different only in that the dust removing step is performed using the dust removing unit 30 instead of the dust removing unit 7.

  In the dust removing process of the present embodiment, the inert gas G is passed through the spray nozzle 32 which is a spraying pipe line different from the inert gas introduction pipe line 9 in the reduced pressure gas replacement process to the portion that is the inner surface of the mold housing part. This is a step of removing dust by spraying. Further, in this step, the inert gas G is blown as described above, and the inert gas G blown through the injection nozzle 32 is also sucked from the suction duct 35.

That is, when the mold assembly 60 is loaded into the loading chamber 51, as shown in FIG. 6, the lifting arm 14 is contracted to raise the movable chamber 6 under the control of the apparatus control section 55, and the dust removing section. The inert gas pumping unit 31 of 7A is controlled to inject the inert gas G from the injection nozzle 32 and spray it onto the stage upper surface 5a.
At this time, the device control unit 55 controls the nozzle movement holding unit 33 to reciprocate the nozzle holding table 33a along the transport direction M. Thereby, the inert gas G sprayed from the injection nozzle 32 is sprayed over the whole surface area | region 5b.

By blowing the inert gas G onto the stage upper surface 5a in this way, the dust floating above the stage upper surface 5a and the dust adhering to the stage upper surface 5a are caught in the air flow of the inert gas G and the stage upper surface 5a. It is removed from above and conveyed to the other side of the stage 5 along with the air flow of the inert gas G.
On the other hand, in parallel with this, the apparatus control unit 55 controls the suction pump 37 to suck the inert gas G from the suction port 35a. For this reason, the dust trapped in the air flow of the inert gas G is sucked together with the inert gas G from the suction port 35 a and collected by the dust collector 38.
The cleaned inert gas G is refluxed into the chamber 52a through the conduit 36b.
In this way, after the dust and the suction of the inert gas G are continued for a certain period of time until the dust is sufficiently removed from the surface region 5b, the dust removal process is terminated.
Thereafter, the reduced-pressure gas replacement step and the molding step are performed in the same manner as in the first embodiment.

According to the present embodiment, as in the first embodiment, the dust in the surface region 5b can be removed before the decompression gas replacement step is performed, and thus the inside of the mold accommodating portion in the decompression gas replacement step is kept clean. Therefore, the optical element molded product can be produced with a high yield.
Moreover, in this embodiment, since dust is removed by blowing the inert gas G, dust can be removed without bringing solids into contact with the stage upper surface 5a. For this reason, it is possible to prevent new dust from being generated due to contact with the solid, and it is possible to more efficiently remove dust.
In the present embodiment, the suction duct 35 sucks not only the airflow jetted from the jet nozzle 32 but also other inert gas G in the chamber 52a. Dust floating in the 52a can be removed in the same manner.
In the present embodiment, since the dust collector 38 is provided outside the chamber 52a, the maintenance of the dust collector 38 is facilitated.

[Third Embodiment]
Next, an optical element molding apparatus according to the third embodiment of the present invention will be described.
FIG. 7 is a schematic partial cross-sectional view of the gas replacement chamber of the optical element molding apparatus according to the third embodiment of the present invention as viewed from the front side in the transport direction. FIG. 8 is a schematic AA sectional view in FIG.

  As shown in FIG. 1A, the optical element molding apparatus 50B of the present embodiment includes a gas replacement chamber 52B instead of the gas replacement chamber 52 of the optical element molding apparatus 50 of the first embodiment. is there. Hereinafter, a description will be given centering on differences from the first embodiment.

As shown in FIG. 7, the gas replacement chamber 52 </ b> B includes a dust removal unit 40 instead of the dust removal unit 7 of the gas replacement chamber 52 of the first embodiment. In FIG. 7, the transport mechanism 17 is not shown for easy viewing.
The dust removing unit 40 is connected to the plurality of spray nozzles 42 (spraying conduits), the plurality of suction nozzles 43 (suction conduits), and the spray nozzles 42 provided so as to penetrate the side surface on the lower end side of the movable chamber 6. It is movable from the suction nozzle 43 via the inert gas pressure feeding part 41 that supplies clean inert gas G to each of the plurality of injection nozzles 42 through the pipeline 42 b and the pipeline 42 b connected to the suction nozzle 43. And a suction pump 44 for sucking the inert gas G inside the chamber 6.
The configuration of the inert gas pumping unit 41 can employ the same configuration as that of the inert gas pumping unit 31.

As shown in FIG. 8, the horizontal arrangement of the injection nozzles 42 of the present embodiment is such that each of the four injection nozzles has four continuous nozzles out of eight parts that divide the movable chamber 6 into eight parts in the circumferential direction. 42 a is arranged radially toward the center side of the movable chamber 6. In the present embodiment, as an example, they are arranged at four positions located on the left side when the conveyance direction M is viewed.
Further, the arrangement of the injection nozzles 42 in the vertical plane is inclined downward as shown in FIG. The inclination angle of the injection nozzle 42 is a shallow angle, for example, greater than 0 ° and less than 30 ° with respect to the horizontal plane.
For this reason, when the lower surface 6d is brought into contact with the stage upper surface 5a, the airflow of the inert gas G injected from the injection port 42a on the stage upper surface 5a is directed toward the center from the inner peripheral portion of the movable chamber 6. And flows along the stage upper surface 5a.

In addition, as shown in FIG. 8, the horizontal arrangement of the suction nozzles 43 of the present embodiment is such that each of the four positions that divide the movable chamber 6 into eight parts in the circumferential direction is continuous. The injection ports 42 a are arranged radially toward the center side of the movable chamber 6. In the present embodiment, as an example, they are arranged at four positions located on the right side when the transport direction M is viewed.
For this reason, each suction nozzle 43 is disposed so as to face the ejection nozzle 42 in the radial direction.
Moreover, as shown in FIG. 7, the arrangement | positioning in the vertical surface of the suction nozzle 43 is inclined by the substantially the same inclination angle as the injection nozzle 42 toward the downward side. For this reason, when the lower surface 6d is brought into contact with the stage upper surface 5a, the airflow flowing along the stage upper surface 5a and rising upward in the vicinity of the inner surface 6a of the movable chamber 6 can be efficiently sucked. .
Moreover, the shape of the injection nozzle 42 can employ the same shape as the injection nozzle 32.

The pipes 42b and 43b are schematically drawn as straight lines in FIG. 7, but have an appropriate length and flexibility that can move following the elevation of the movable chamber 6.
Further, the inert gas pumping unit 41 is connected to an inert gas source (not shown), and the suction pump 44 is connected to an inert gas recovery unit (not shown).
The inert gas recovery unit may include a dust collector and the like as in the second embodiment, and may form a circulation path for purifying the inert gas G and then introducing it into the inert gas source.
In FIG. 7, the example in which the inert gas pumping unit 41 and the suction pump 44 are disposed outside the gas replacement chamber 52 </ b> B has been described. However, the gas replacement chamber 52 </ b> B together with the inert gas source and the inert gas recovery unit. It is good also as a structure arrange | positioned inside.

In the present embodiment, the pipe line 42b and the inert gas pumping part 41 are sprayed with a gas that blows the inert gas G through the injection nozzle 42 different from the inert gas introduction pipe line 9 onto the inner surface of the mold housing part. Part.
Further, the pipe line 43b and the suction pump 44 constitute a gas suction part that sucks the inert gas G blown through the injection nozzle 42 from the suction nozzle 43 to the outside of the mold housing part.

Next, the operation of the optical element molding apparatus 50B of the present embodiment will be described focusing on the optical element molding method of the present embodiment.
FIG. 9A is a timing chart of gas blowing and gas suction in the optical element molding method according to the third embodiment of the present invention.

  The optical element forming method of the present embodiment includes a dust removing process, a reduced-pressure gas replacement process, and a molding process, as in the first embodiment. However, in the present embodiment, the point that the dust removing process is performed by using the dust removing unit 40 instead of the dust removing unit 7 is different from the raising / lowering operation of the movable chamber 6 only.

  In the dust removing process of the present embodiment, the inert gas G is passed through the injection nozzle 42, which is a spraying pipe line different from the inert gas introduction pipe line 9 in the reduced pressure gas replacement process, to the inner surface of the mold housing part. This is a step of removing dust by spraying. Further, in this step, the inert gas G is blown as described above, and the inert gas G blown through the spray nozzle 42 is also sucked from the suction nozzle 43.

That is, when the mold assembly 60 is loaded into the loading chamber 51, as shown in FIG. 7, the lifting arm 14 is extended under the control of the apparatus control unit 55, and the lower surface 6d of the movable chamber 6 becomes the stage upper surface 5a. Lower until it touches.
Thereby, the inside of the movable chamber 6 is sealed by the stage upper surface 5a. In this state, the apparatus control unit 55 controls the inert gas pumping unit 41 of the dust removing unit 40 to inject the inert gas G from each injection nozzle 42 and spray it onto the stage upper surface 5a.
Further, the device control unit 55 controls the suction pump 44 to suck the inert gas G in the movable chamber 6 by each suction nozzle 43.
For example, when the diameter of the injection port 32a of the injection nozzle 42 is about 5 mm, the injection pressure of the inert gas G is preferably atmospheric pressure + 0.3 MPa to atmospheric pressure + 0.5 MPa.
The suction flow rate is preferably about 150 L / min when the diameter of the suction port 43a of the suction nozzle 43 is about 5 mm, for example.
At this time, since the inert gas G for removing dust is supplied from the injection nozzle 42, the inert gas introduction line 9 can be closed.

By blowing the inert gas G from the injection nozzle 42 onto the stage upper surface 5a in this way, dust floating above the stage upper surface 5a or dust adhering to the stage upper surface 5a is caught in the air flow of the inert gas G. Then, it is removed from the stage upper surface 5a and conveyed radially inward.
On the other hand, since the suction nozzles 43 are arranged at positions opposite to the respective injection nozzles 42, the airflow including dust that has reached the center in the radial direction is sucked in by the respective suction nozzles 43 and on the opposite side in the radial direction. Opposite, it is sucked into the pipe line 43 b from the suction port 43 a of one of the suction nozzles 43 and removed from the inside of the movable chamber 6.
The inert gas G and dust exhausted from the suction pump 44 are recovered by an inert gas recovery unit (not shown). When a dust collector is provided in the inert gas recovery unit, the dust is collected in the dust collector.

In this way, after the dust and the suction of the inert gas G are continued for a certain period of time until the dust is sufficiently removed from the surface region 5b, the dust removal process is terminated.
In the present embodiment, as an example, as indicated by the broken lines 200 and 201 in FIG. 9A, the injection from the injection nozzle 42 and the suction of the suction nozzle 43 are started at time t1, and time t4 (however, t4 > At t1), the timing at which the respective injections and suctions are simultaneously terminated is adopted.

  After completion of the dust removal process, the device control unit 55 stops the blowing of the inert gas G from the suction nozzle 43 and the gas suction from the suction nozzle 43, and extends and retracts the elevating arm 14, thereby moving the movable chamber 6 to the gold. Raise to a position higher than the upper part of the mold assembly 60. Thereafter, the reduced-pressure gas replacement step and the molding step are performed in the same manner as in the first embodiment.

According to the present embodiment, as in the first embodiment, the dust in the surface region 5b can be removed before the decompression gas replacement step is performed, and thus the inside of the mold accommodating portion in the decompression gas replacement step is kept clean. Therefore, the optical element molded product can be produced with a high yield.
Further, in the present embodiment, dust is removed by spraying the inert gas G. Therefore, as in the second embodiment, new dust is prevented from being generated due to solid contact, and the dust is efficiently collected. Can be removed.

  In the present embodiment, the movable chamber 6 is lowered to form a sealed space with the stage upper surface 5a, and the inert gas G is sprayed and sucked inside the sealed space. In the meantime, since dust does not enter from the outside of the movable chamber 6, dust can be efficiently removed.

  Further, in the present embodiment, since the inert gas G is blown through the spray nozzle 42 which is a spray pipe different from the inert gas introduction pipe 9 to remove dust, the jet nozzle 42 and the inert gas introduction pipe are used. 9 can be arranged at appropriate positions. In this embodiment, since the injection nozzle 42 is provided so as to penetrate the side surface on the lower end side of the movable chamber 6, dust in the surface region 5b can be efficiently removed. In the present embodiment, the inert gas introduction conduit 9 passes through the center of the upper surface 6 c of the movable chamber 6, and the opening on the lower end side of the inert gas introduction conduit 9 protrudes to the inside of the movable chamber 6. Therefore, it is possible to prevent the dust from being rolled up when the inert gas is introduced.

  Moreover, in this embodiment, since the inert gas sprayed through the injection nozzle 42 is sucked from the suction nozzle 43, the suction nozzle 43 sucks dust trapped in the air flow of the sprayed inert gas G. Therefore, it is possible to prevent the dust trapped in the air flow of the inert gas G from adhering to the inner surface of the movable chamber.

  Further, in the present embodiment, the inert gas blown through the injection nozzle 42 is sucked from the suction nozzle 43 which is a blowing pipe line different from the inert gas introduction pipe line 9, so that the inert gas is used in the dust removing process. It is possible to prevent dust from adhering to the introduction conduit 9. Accordingly, it is possible to prevent dust from being supplied into the movable chamber 6 from the inside of the inert gas introduction conduit 9 and attaching dust to the movable chamber 6 in the reduced pressure gas replacement step.

In the present embodiment, since four injection nozzles 42 are provided in a region that occupies half of the inner circumference of the inner surface 6a, the inert gas G is simultaneously injected from the four injection nozzles 42. Since the air flow from the semicircular part to the other semicircular part is generated at the same time and suction is performed by the plurality of suction nozzles 43 in the other semicircular part, the surface region 5b is swept from one side to the other side entirely. A steady air flow is generated, and dust on the surface region 5b can be completely removed.
For this reason, unlike the case of the second embodiment, it is not necessary to move the spray conduit, so that dust can be quickly removed. In addition, since there is no movable part for moving the spray pipe, there is no possibility of generating new dust due to wear of the movable part.

Next, various modified examples (third to seventh modified examples) of the present embodiment will be described.
FIGS. 9B and 9C are timing charts of the third and fourth modified examples.

In this embodiment, since the inert gas G is sprayed and sucked in the sealed space, in order to form a stable air flow of the inert gas G carrying dust, the spraying (jetting) and the suction are performed to some extent. Although it is necessary to carry out in parallel in the overlapping time zone, as shown in FIG. 9A, the timing of injection and suction may not be completely overlapped.
For example, as a third modified example, as shown by a broken line 203 in FIG. 9B, the injection starts at time t1, ends at time t3, and as shown by a broken line 204 in FIG. 9B. Suction may be started at t2, and suction may be terminated at time t4. However, t1 <t2 <t3 <t4 (and so on).
In this modification, since suction is performed after jetting is performed, suction is performed after dust is scattered by the impact of jetting. For this reason, it becomes easy to separate dust from the surface of the stage upper surface 5a.
Note that the end timing of injection and suction in FIG. 9B is an example, and either may be ended first if the inside of the movable chamber 6 does not become negative pressure.

Further, for example, as a fourth modification, as shown by a broken line 205 in FIG. 9C, the injection starts at time t2, ends the injection at time t4, and is shown by a broken line 206 in FIG. 9C. At this time, suction may be started at time t1, and suction may be terminated at time t3.
In this modification, since the injection is performed after the suction is performed in advance, the airflow after the injection is likely to be a stable airflow, and it is easy to move the dust along the surface of the stage upper surface 5a. For this reason, since dust scattering is suppressed, efficient dust removal can be performed.
Note that the end timing of the injection and suction in FIG. 9C is an example, and either may be ended first if the inside of the movable chamber 6 does not become negative pressure.

Next, a fifth modification of the present embodiment will be described.
FIG. 10 is a timing chart of gas blowing and gas suction in the optical element molding method according to the fifth modification of the third embodiment of the present invention.

This modification is an example of the case where the inert gas G is intermittently sprayed (injected) in the dust removing step, and the inert gas G is also suctioned intermittently.
That is, the inert gas pumping unit 41 is controlled by the device control unit 55, and as shown by the broken line 207 in FIG. 10, the injection is repeatedly turned on and off between the time t <b> 1 and the time t <b> 4 and the suction is performed by the device control unit 55. By controlling the pump 44, the suction is repeatedly turned on and off in synchronization with the injection timing.
As a result, a pulsed jet flow sequentially acts on the stage upper surface 5a. For this reason, since the repeated impact force acts on the dust on the stage upper surface 5a via the inert gas G, the dust is easily separated from the stage upper surface 5a.
That is, this modification is an example in which the strength of blowing the inert gas G from the injection nozzle 42 and the strength of suction of the inert gas G from the suction nozzle 43 are periodically changed.
In order to apply a repeated impact force to dust, it is not necessary to completely turn on and off the spraying and suction. For example, the strength of spraying and the strength of suction may be changed to a sine wave shape, a mountain shape, a sawtooth wave shape, or the like. Further, the periodic fluctuation is not limited to a case where the fluctuation varies accurately with a constant period, and the period may fluctuate as long as it is a periodic repetitive change.

Next, a sixth modification of the present embodiment will be described.
This modification is a modification when a time difference is provided for each of the spray timings of the plurality of injection nozzles 42.
In this modification, the flow rate adjustment valve of the inert gas pressure feeding unit is configured so that the injection timing can be controlled for each pipe line 42 b connected to each injection nozzle 42 by the device control unit 55.
For example, the injection timings from the respective injection nozzles 42 are sequentially switched in the clockwise or counterclockwise order in the order in which they are arranged in the circumferential direction.
By switching the injection timing in this way, it is possible to perform the same spraying as when the injection nozzle 42 is moved in the circumferential direction on the semicircle along the inner surface 6a.
In this case, since the direction of the air flow of the inert gas G sprayed to the dust at a fixed position changes with time, even if the dust has directionality in the magnitude of the adhesive force, it can be easily removed.
Further, it is possible to perform the same spraying as when the injection nozzle 42 is moved without providing a mechanical movable part that easily generates new dust.

Next, a seventh modification of the present embodiment will be described.
This modified example is a modified example in which an inert gas G that is lower in speed than the inert gas G injected from the injection nozzle 42 is caused to flow from the inert gas introduction conduit 9 in the dust removing step. .
In this case, depending on the inflow amount of the inert gas G from the inert gas introduction pipe 9, the inside of the movable chamber 6 becomes a positive pressure and it becomes difficult to introduce from the inert gas introduction pipe 9. By adjusting the suction flow rate from the nozzle 43, the suction amount is increased to such an extent that the inside of the movable chamber 6 does not become a negative pressure.
According to this modification, the flow in the direction along the ceiling surface 6 b and the inner side surface 6 a of the movable chamber 6 is generated by the low-speed inert gas G introduced from the inert gas introduction conduit 9.
For this reason, it becomes easy to remove the dust adhering to the ceiling surface 6b and the inner surface 6a. Further, the dust scattered from the stage upper surface 5a is less likely to reattach to the ceiling surface 6b and the inner surface 6a.
The flow rate of the inert gas G from the inert gas introduction pipe 9 is such that the dust flow conveyed on the stage upper surface 5a is disturbed by the flow from above, and most of the dust does not return upward. Set the flow rate to.

  It should be noted that each of the above-described embodiments and modifications can be appropriately modified and implemented within the scope of the technical idea of the present invention.

In the description of the first to third embodiments, an example in which the dust removing process is performed after the mold assembly 60 is loaded into the loading chamber 51 and the shutter 4 is opened has been described. In this case, it is possible to remove dust that may enter from the charging chamber 51 by opening the shutter 4.
However, for example, when the cleanliness of the atmosphere in the charging chamber 51 is high, the dust removal process is performed any time before the reduced pressure gas replacement process is performed by placing the mold assembly 60 on the surface region 5b. Also good. That is, it may be performed before the next mold assembly 60 is loaded into the loading chamber 51 or may be performed before the shutter 4 is opened.

In the description of the first to third embodiments, an example in which the movable chamber 6 is raised when the shutter 4 is opened has been described. In this case, when the shutter 4 is opened, the dust removing process can be performed immediately, and the mold assembly 60 can be transferred onto the surface region 5b immediately after the dust removing process, which is efficient.
However, the movable chamber 6 may be lowered when the shutter 4 is opened, and the dust removing process may be started by raising the movable chamber 6 after a certain period of time after the shutter 4 is opened. That is, the movable chamber 6 may be lowered before the dust removing step and brought into contact with the stage upper surface 5a.
In this case, since the sealed space is formed until just before the dust removing step is started, even if dust flows into the chamber 52a when the shutter 4 is opened, the inner side surface 6a or the ceiling of the movable chamber 6 It does not adhere to the surface 6b. Then, the dust removal process can be performed after the inflowing dust descends.

Further, in the description of the second embodiment, the example in which the nozzle movement holding unit 33 reciprocates the injection nozzle 32 in the transport direction M has been described, but the inert gas G injected from the injection nozzle 32 is described. Is jetted over the entire surface area 5b, the movement of the jet nozzle 32 is not limited to this.
For example, a configuration in which the spray nozzle 32 is rotatably held in a horizontal plane and can be swung in the horizontal direction may be employed. In addition to this, or in conjunction with the movement in the transport direction M by the nozzle movement holding unit 33, a configuration is adopted in which the ejection nozzle 32 is rotatably held in the vertical plane and can swing in the vertical plane. May be.
Further, a plurality of injection nozzles 32 may be provided so that the entire surface area 5b can be injected more quickly.

  In the description of the second embodiment, the suction duct 35 is described as an example in which one suction port 35a is provided so as to extend along the transport direction M. However, the suction duct 35 includes a plurality of suction ports. The mouth 35a may be provided close to or apart from the mouth 35a.

  In the description of the second embodiment, the example in which the suction pipe is configured to circulate the inert gas G in the gas replacement chamber 52 </ b> A has been described. G may be recovered in an appropriate inert gas recovery unit and not returned to the gas replacement chamber 52A.

  In the above description of the second and third embodiments, the injection nozzles 32 and 42 have been described as an example in which the inert gas G is sprayed onto the stage upper surface 5a. The surface region 5b is not limited. Any part of the inner surface of the mold housing part may be sprayed as long as it easily adheres to dust. For example, you may provide the injection nozzles 32 and 42 so that the inert gas G may be sprayed in the direction in alignment with the ceiling surface 6b and the inner surface 6a of the movable chamber 6. FIG.

  In the description of the fifth modification of the third embodiment, the example in which the strength of spraying and suction of the inert gas G is varied has been described. However, the dust is repeatedly passed through the inert gas G. Since it is sufficient if an impact force can be applied, the strength of either spraying or suction may be varied. That is, the intensity of at least one of spraying and suction may be periodically changed.

  In the above description of the first to third embodiments, an example has been described in which a dust removing step is performed on all mold assemblies 60 before performing a reduced pressure gas replacement step. Depending on the amount of intrusion and the allowable yield, the number of dust removal steps may be reduced.

In addition, all the components described in the above embodiments and modifications can be implemented by appropriately changing or deleting combinations within the scope of the technical idea of the present invention.
For example, in the dust removal step, it is sufficient that dust can be removed from the inner surface of the mold housing portion. Therefore, in the second embodiment, the suction pipe and the gas suction portion may be omitted. In this case, since the dust is removed from the surface region 5b by blowing the inert gas G by the injection nozzle 32, the pressure is reduced even if dust remains in the gas replacement chamber 52A outside the surface region 5b and on the stage upper surface 5a. Dust does not enter the gap in the mold assembly 60 in the gas replacement process.

Next, Examples 1 to 3 of the optical element molding methods of the first to third embodiments will be described together with comparative examples.
Examples 1 to 3 and the comparative example are both in common, and the mold assembly 60 has an outer shape of an outer diameter of 30 mm × height of 30 mm, and the movable chamber 6 has an inner surface shape of Using a glass having an inner diameter of 50 mm and a height of 70 mm, 1200 glass lenses were molded over 20 hours. As the inert gas G, N ₂ is adopted.

In Example 1, a dust removing process was performed using the dust removing unit 7 of the first embodiment. As the cleaning roller 7a, a silicon rubber roller having an adhesive layer on the surface was adopted.
In Example 2, the dust removing process was performed using the dust removing unit 30 of the second embodiment. The nozzle diameter of the injection nozzle 32 was 5 mm in diameter, and the injection pressure was atmospheric pressure + 0.3 MPa.
In Example 3, the dust removing process was performed using the dust removing unit 40 of the third embodiment. The nozzle diameter of each injection nozzle 42 was 5 mm in diameter, and the injection pressure was atmospheric pressure + 0.5 MPa. The suction flow rate of each suction nozzle 43 was 150 L / min. As shown in FIG. 9A, the timing of spraying and suction was performed in synchronization, and the spraying time was 10 seconds.
Moreover, the comparative example performed the decompression gas substitution process, without performing a dust removal process.

And in Examples 1-3 and the comparative example, the external appearance test | inspection of each shape | molded lens was performed, and the external appearance defect rate judged to originate in adhesion of dust was computed.
The defective appearance rate was 5% in Example 1, 4% in Example 2, and 3% in Example 3, and good results were obtained. On the other hand, the appearance defect rate of the comparative example was 15%.
Thus, in Examples 1 to 3 using the optical element molding method of the present invention, it was possible to significantly reduce the appearance defect rate as compared with the comparative example.
In addition, compared with Examples 1 and 2, particularly good results were obtained in Example 3 because the dust removal process was performed by blowing and sucking inert gas G in the sealed space, so that more dust was removed. It is thought that it can be removed reliably.

4, 20 Shutter 5 Stage (mold receiving part)
5a Stage upper surface 5b Surface area (site to be the inner surface of the mold housing part)
6 Movable chamber (mold receiving part)
6a Inner side surface (site to be the inner surface of the mold housing part)
6b Ceiling surface (part which becomes the inner surface of the mold housing part)
6d Lower surface 6e Seal member 7, 7A, 7B, 30, 40 Dust removal part 7a Cleaning roller 7b Movable arm 9 Inert gas introduction line (introduction line)
13 Vacuum pump (decompression unit)
14 Lifting arm 15 Cleaning blade 16 Cleaning pads 31, 41 Inert gas pumping part (gas spraying part)
32, 42 spray nozzle (spraying pipeline)
33 Nozzle movement holding part (gas spraying part)
36a, 43b Pipe line (gas suction part)
35 Suction duct (suction line)
37, 44 Suction pump (gas suction part)
42a Pipe line (gas blowing part)
43 Suction nozzle (suction line)
50, 50A, 50B Optical element molding device 51 Input chamber 52, 52A, 52B Gas replacement chamber 52a Chamber 53 Molding chamber 55 Device controller 60 Mold assembly 61 Lower mold (mold)
61a, 62a Molding surface 62 Upper mold (mold)
63 Body type (mold)
64 Molding material G Inert gas M Conveying direction

Claims (6)

Optical element molding for sequentially molding a plurality of mold assemblies in which molding materials are arranged in a mold having a molding surface for molding an optical element, and then heating and pressing in an inert gas atmosphere to mold the optical element A method,
Before performing the heating and pressing, the mold assembly is housed in a mold housing portion, the mold housing portion is decompressed, and an inert gas is introduced into the mold housing portion through an introduction pipe line. And a reduced pressure gas replacement step of replacing the atmosphere inside the mold housing part and the mold assembly with the inert gas,
Before removing the mold assembly in the mold housing portion, removing dust from a portion that becomes an inner surface of the mold housing portion; and
Equipped with a,
In the dust removal step,
The dust is removed by blowing the inert gas onto a portion that becomes an inner surface of the mold housing portion through a blowing pipe that is different from the introduction pipe in the reduced pressure gas replacement step. Optical element molding method. In the dust removal process,
2. The optical element molding method according to claim 1 , wherein the inert gas blown through the blowing pipe is sucked from the suction pipe. 3. The apparatus according to claim 2 , wherein at least one of the strength of blowing the inert gas from the blowing pipe and the strength of sucking the inert gas from the suction pipe is periodically changed. The optical element shaping | molding method of description. Optical element molding for sequentially molding a plurality of mold assemblies in which molding materials are arranged in a mold having a molding surface for molding an optical element, and then heating and pressing in an inert gas atmosphere to mold the optical element A device,
A mold housing part for housing the mold assembly in a sealed state;
A decompression section for decompressing the interior of the mold housing section;
Introducing the inert gas to replace the atmosphere inside the mold housing with the inert gas, and
A dust removing unit for removing dust from a portion that is an inner surface of the mold housing unit;
Equipped with a,
The dust removing unit is
An optical element molding apparatus , comprising: a gas spraying part for spraying an inert gas through a spraying line different from the introduction line on a portion which is an inner surface of the mold housing part . The dust removing unit is
5. The optical element molding apparatus according to claim 4 , further comprising a gas suction unit that sucks the inert gas blown through the blowing pipe line from the suction pipe line to the outside of the mold housing part. The spraying pipe and the suction conduit is provided in the mold housing part, in a state where the mold accommodating portion is closed, according to claim 5, characterized in that so as to perform the dust removal Optical element molding apparatus.

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