JPH0543259A - Production of optical element - Google Patents

Abstract

PURPOSE:To provide the process for production of the optical element which is devised to avert the subsequent trouble based on the sticking of a molding to an upper mold member at the time of parting from the mold so as to allow the execution of continuous molding or molding at a high speed while maintaining good accuracy of the optical element. CONSTITUTION:This process for production of the optical element consists in producing the molding having a required optical function surface by housing a glass blank material for molding between the upper and lower mold members of the forming mold and press forming the material in the state of heating the material to a desired temp., then cooling the molding and parting the molding from the mold. The above-mentioned molding taking out stage includes a stage for detecting the position of the molding existing between the mold members by a sensor 7 in the state of opening the upper and lower mold members to a prescribed quantity, a stage for fully opening the mold members in accordance with the result of the position detection and a stage for taking out the molding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an optical element, and more particularly to a glass optical element having an optical functional surface,
The present invention relates to a method for manufacturing an optical element to be obtained by press molding.

[0002]

2. Description of the Related Art Recently, a glass material for molding an optical element between upper and lower mold members having a predetermined surface accuracy, for example,
A method for manufacturing an optical element has been developed in which a glass blank preformed to a certain shape and surface accuracy is housed and press-molded under heating to eliminate the need for post-processing such as grinding and polishing.

In the case of manufacturing an optical element by such press molding, in a generally used molding die, an upper mold member and a lower mold member are slidably opposed to each other in a barrel mold. The structure is such that a glass material for molding is introduced into a region surrounded by these members, and the upper and lower mold members are brought relatively close to each other and pressed into a predetermined shape. At this time, in order to prevent the mold member from being oxidized, a non-oxidizing atmosphere such as a nitrogen atmosphere is used, and a moldable temperature, for example, a temperature at which the glass material for molding has a viscosity of 10 ⁸ to 10 ¹² poises. Heat the above glass material until. Then, after the molding die is closed, the molding surface of the mold member is transferred to the material surface by pressing for a required time. Then, the mold member is cooled to the glass transition temperature, and in that state, the pressing pressure is removed. In this way, when the molding is completed, the molding die is opened and the product is taken out.

The glass material may be heated to an appropriate temperature before being introduced into the mold member, or the glass material may be heated to a moldable temperature and then introduced into the mold member. Further, it may be possible to achieve continuous and high-speed operations such as heating, flossing, and cooling in the process of conveying the glass material together with the mold member.

A method for manufacturing the above optical element, and
The device is disclosed in, for example, JP-A-58-84134,
JP-A-49-97009, British Patent No. 37
8199, JP 63-11529, JP 59-150728 and JP 61-265.
No. 28 publication and the like.

[0006]

The problem here is the releasing operation after the press molding. Immediately after pressing, the molded product strongly adheres to the mold member, but in the process of subsequent temperature decrease, thermal stress occurs due to the difference in the coefficient of thermal expansion between the mold member and the glass material, causing mold release. However, the timing of this mold release is not constant, and it is not determined which of the upper and lower mold members remains attached when the mold is opened. Therefore, for example, when a molded product adheres to the upper mold member, when the upper mold member rises, it peels off by its own weight, falls onto the lower mold and is damaged, and also the lower mold member. May damage the molding surface of. Further, if the toner remains attached to the upper mold member, auto-handling cannot be performed in the subsequent step of taking out.

Such adhesion to the upper mold becomes a factor that hinders the smooth operation of the molding apparatus. Already, regarding the cooling and releasing steps in the molding apparatus, for example, JP-A-62-91430, JP-A-60-81032, JP-A-52-45613 and JP-B-61-
No. 32263 is known, but the manners of cooling and mold release disclosed in these publications are simple, and there is no mention of solving the problem of adhesion of the molded product to the upper mold member. ..

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is possible to perform molding continuously or at high speed while maintaining good precision of an optical element. An object of the present invention is to provide a method for manufacturing an optical element devised so as to avoid subsequent troubles due to adhesion of a molded product to a mold member.

Another object of the present invention is to heat and press the glass material to press-mold a desired optical element, and then at the stage of taking out the optical element, the robot
The object is to detect whether or not the molded product is placed in a position and posture that are inconvenient for the suction / holding operation of the molded product with a hand or the like, and avoid damage to the molded product and equipment during the taking-out operation. That is, it includes a step of sensing whether or not there is a molded product at a convenient position (location), not at a position inconvenient for the robot hand to pick up or hold it, and as a result of the above sensing, Wait for the operation, for example, to move to the step of moving the mold member to the molded product take-out position, or to reach a convenient state when the molded product is attached to the mold member side where the take-out is inconvenient, that is, By waiting for the molded product to drop from the mold member and realizing the transition to the removal process, it is intended to smoothly perform the removal operation of the molded product.

Further, according to the present invention, when the optical element is taken out after the molding process by heating, pressurizing, and cooling, the molded product is taken out from the closed state to the open state for taking out the molded product. To prevent damage to the molded product due to opening when the product is attached to the upper mold member side and then dropping onto the lower mold member due to detachment from the upper mold member, so that damage due to that drop can be prevented There is provided a method for manufacturing an optical element in which a mold member is opened at a distance of 1, the position of a molded product is confirmed, and then the mold member is opened to a take-out position.

Further, according to the present invention, in a continuous method for producing an optical element, the steps of heating a glass material and a mold member, pressurizing the glass material, cooling a molded product, and taking out the molded product are repeated. It is possible to shorten the cycle time by interlocking with the confirmation of the position of the molded product by opening the member and by completing the cooling process and / or starting the heating process.

Furthermore, according to the present invention, after the glass material, the mold member is heated, the glass material is pressed, and the molded product is cooled, the automatic removal operation by machine operation is smoothly realized in the next molded product removing step. We will propose a failure prevention measure for this. That is, in the molded product removing step, when the mold member is opened with the molded product attached to the upper mold member, and then the molded product falls on the lower mold member, the molded product is robotized on the lower mold member. Since it is necessary to maintain a posture suitable for being sucked and gripped by the hand, a step of confirming the posture of the molded product is included, and the operation of the next stage is executed after this confirmation step.

This is because the glass forming temperature (glass viscosity is 1
The glass is cooled to a temperature range where the glass does not deform after being molded in the vicinity of 0 ^8-12 poise), but the glass temperature in the take-out process is still high at about 300 ° C, and the forming atmosphere of the glass material in the forming process is still high. There is a risk that the fingers of the robot hand will be thermally affected, and in order to avoid this, it is necessary to use a material such as metal or ceramic for the above-mentioned fingers. If the molded product is not placed on the lower mold member in a proper posture when the molded product is sucked and gripped by moving to, the accessed finger may damage the molded product. Is. Therefore, the confirmation step is effective in avoiding damage to the molded product due to the take-out means such as the fingers.

[0014]

Therefore, according to the present invention,
By accommodating the glass material for molding between the upper and lower mold members of the mold,
In the method for producing an optical element, the glass material is press-molded in a state where it is heated to a desired temperature, and then cooled and released to produce a molded article having a required optical function surface. When loaded in between, a heating step of heating the glass material and the mold member respectively, a molding step of press-molding the glass material between the upper and lower mold members at a glass molding temperature, and then the glass together with the upper and lower mold members. It consists of a cooling step of cooling the material toward the extraction temperature, and a molding product unloading process of opening the space between the upper and lower mold members and taking out a molded product after or after the cooling process. A step of detecting a position of a molded article existing between the mold members in a state where the upper and lower mold members are opened by a predetermined amount, and a step of fully opening the mold members based on the position detection result, And includes a step of taking out the molded article.

Further, according to the present invention, the glass material for molding is housed between the upper and lower mold members of the mold, press-molded in a state of being heated to a desired temperature, and then cooled and released to achieve a desired optical function. In a method of manufacturing an optical element adapted to manufacture a molded article having a surface, a heating step of heating the glass material and the mold member respectively when loading the glass material between the upper and lower mold members, and a glass molding temperature. In the molding step of press-molding the glass material between the upper and lower mold members, thereafter, a cooling step of cooling the glass material together with the upper and lower mold members toward the temperature of taking out, and after the cooling step or the end of the cooling step, The process includes a molded product taking-out step of opening the mold members and taking out the molded product. In the molded product taking-out step, the upper and lower mold members are opened by a predetermined amount, and the molding members are present between the mold members. The step of determining the orientation of the goods, the step of fully open between the mold member on the basis of the attitude determination result, and comprises a step of taking out the molded article.

Various other measures for achieving the above object will be clarified in the embodiments described below.

[0017]

EXAMPLES The production method of the present invention will be specifically described below with reference to the illustrated examples. Here, a case where a biconvex lens having a diameter of 16 mm is molded from a glass blank is shown. The glass blank used here is the spherical glass material 3 of the optical glass SK12, and its surface roughness is R _max = 0.04 μmm. The mold shown in FIG. 1 is housed in a casing (not shown), and the casing is depressurized to 1 × 10 ^-2 Torr and then nitrogen gas is introduced. Then, the upper mold member 1 and the lower mold member 2 constituting the molding die are heated to 610 ° C. by the heater 5 provided on the body mold 4 surrounding them. When the mold members 1 and 2 were heated to 610 ° C., the glass material 3 preheated in the same casing was adsorbed by using the adsorption hand 8 and opened in the barrel mold 4. Place it on the mold member 2 below from the doorway. Then, the upper mold member 1 is lowered through an operating means such as a ram, and press molding is performed. The lowering of the mold member 1 is continued until the stopper portion provided on the upper edge of the mold member 1 contacts the body mold 4,
At that stage, the glass material 3 is molded into a predetermined molded product (see FIG. 2). After that, the power supply to the heater 5 is cut off, and for example, nitrogen gas is passed through the cooling passages 9 provided in the respective mold members 1 and 2 to perform cooling. Next, the upper and lower mold members 1 and 2 are below the transition temperature of glass, for example, 51
When cooled to 0 ° C., the upper mold member 1 is raised again via the above-mentioned operating means. At this time, the molded product 6 adheres to the upper mold member 1 and rises together, and then the molded product 6 is peeled off due to its own weight, thermal stress generated there, or the like, and is dropped onto the mold member 2 and is damaged. At a height that does not occur, for example, about 3 mm, the rising of the upper mold member is interrupted intermediately (see FIG. 3). Although the amount of increase is 3 mm in this embodiment, it may be 15 mm or less, preferably 5 mm or less. At this stage, the sensor 7 is used to determine whether or not the molded product 6 is attached to the surface of the upper mold member 1. If it is not adhered, immediately, and if it is adhered, wait until it falls on the lower mold member (usually it drops in about 5 seconds), and the next step is the upper mold. The raising operation of the member is restarted. When the mold member 1 has risen to a predetermined height, the molded product 6 left on the lower mold member 2 is sucked and held from the entrance of the barrel mold 4 through the suction hand 8.
It is taken out of the mold (see FIG. 4).

Incidentally, when an optical element was actually molded using such a molding apparatus, the surface precision of the optical element was measured by the Newton method when the continuous molding of about 100 shots was carried out. A good continuous work as a whole can be performed with about 2, as many as 0.5 habits, and as a result of the molded product 6 adhering to the upper mold member 1, the molded product 6 is damaged or the lower mold member 2 is damaged. The effects were that there were no accidents that caused damage, work was not interrupted, and workability was improved. Even when a convex meniscus lens having a diameter of 26 mm is manufactured using the above-mentioned molding apparatus, a glass material made of optical glass SF8 is used for the glass blank at that time, and the temperature of the upper and lower mold members 1 and 2 is set to 510 ° C. By performing press molding afterwards and releasing at 370 ° C., although there were some adhesion of the molded product to the upper mold member 1, continuous operation was possible for 100 shots as well and troubles could be avoided.

As described above, according to the present invention, when the upper die member is first raised by a predetermined amount at the time of releasing the die, and when the molded article adheres to and follows the die member, for example, a sensor or the like is used. Detecting this, wait for the molded product to separate and drop from the upper mold member due to its own weight and thermal stress, and then raise the upper mold member so that the molded product can be taken out. Since the mold is released, maintaining good optical element accuracy,
Molding can be performed continuously or at a high speed, and subsequent troubles due to the adhesion of the molded product to the upper mold member at the time of mold release can be avoided.

The manufacturing method of the present invention is applied when manufacturing an actual optical element shown below. Next, a case where the above-mentioned optical element is manufactured by using the apparatus shown in FIGS. 6 to 7 and the process thereof will be specifically described with reference to the time chart of FIG.

In the figure, 102 is a casing,
104a and 104b are the supporting legs. The casing is provided with a substitution chamber 108 on the side of the molding chamber 106, and includes the molding chamber 106 and the substitution chamber 108 that are shielded from the outside air.
08 is a sealable gate valve 1 provided therebetween
A gate valve 112 which is partitioned by 10 and which can be sealed from the outside is provided in the lower portion of the replacement chamber 108.

Below the gate valve 112, an inlet / outlet means 120 is arranged to feed the molding material into the replacement chamber 108 from the outside and further from the inside of the replacement chamber 108 to the outside. And the molded optical element is taken out.

In the vicinity of the substitution chamber 108, the transfer means 1
22 is arranged to convey the molding material in the substitution chamber 108 into the molding chamber 106, and further to convey the molding material to the molding chamber 106.
The molded optical element is conveyed from the inside into the substitution chamber 108.

In the molding chamber 106, a heating section 124,
A transfer unit 126 and a press unit 128 are provided, and the press unit 128 has two units as shown in FIG.
Two equivalent press molding machines P ₁ and P ₂ are arranged in parallel.
Further, the heating section 124 receives the molding material conveyed into the molding chamber 6 by the conveying means 122 and heats the material to an appropriate temperature, and the transfer section 126.
It is possible to receive the molded optical element from the. The transfer unit 126 transfers the molding material in the heating unit 124 to the press unit 128, and further,
The molded optical element in the press section is attached to the heating section 1
It works to transfer to 24. In addition, the press unit 12
In 8, the molding material transferred by the transfer unit 126 is heated to an appropriate temperature and then pressed by the molding die member. The details of each of the above parts are
This will be described below.

In the feeding / unloading means 120, the cylinder 132 is supported by the supporting legs 134a and 134b, and the piston rod 136 thereof can move in the vertical direction, and the upper end thereof has a molding material or a molding material. A mounting table 138 for mounting the completed optical element is attached. The above-mentioned mounting table 138 mounts two molding materials or molded optical elements corresponding to the _two press molding machines P ₁ and P ₂ provided as the press section 128 in the molding chamber 106. As described above, for example, the two mounting portions are arranged side by side in the direction perpendicular to the paper surface of FIG. Further, the mounting table 138 described above has the replacement chamber 10 operated by the action of the cylinder 132 when the gate valve 112 is open.
The molding material and the molded optical element can be delivered at the upper and lower end positions of the moving stroke.

In the transfer means 122, the rodless cylinder 142 is horizontally supported by the rodless cylinder support legs 144a and 144b with the longitudinal direction of the rodless cylinder 142 facing the replacement chamber 108, and the rodless cylinder 142 is also supported. A bearing member 146, which is horizontally reciprocated in its longitudinal direction by 142, is provided. A transport shaft 148 is rotatably supported at one end of the bearing member in a state parallel to the moving direction, that is, in a horizontal state. The other end of the transfer shaft is provided with the replacement chamber 8
A suction means 150 for sucking the molding material or the molded optical element is attached to the tip end portion thereof. The bearing member 146 includes
In order to drive the transport shaft 148 to rotate, the rotation motor 15
2, an output gear 154, and a gear 156 that meshes with the gear 154.

The adsorption means 150 includes the mounting table 13 described above.
Corresponding to the disposition of the two mounting parts 8 in FIG. 8, two suction parts are provided on each of the upper and lower surfaces (see FIG. 6). When it is done, it is turned upside down. In addition, it is preferable that the suction means 150 has a heater built therein.

The movement of the suction means 150 in the horizontal direction is such that the displacement chamber 108 above the mounting table 138 is opened when the gate valve 110 between the displacement chamber 18 and the molding chamber 16 is open.
From the inner position (the position shown in FIG. 5) to the molding chamber 106.
To the position of the heating part 124 inside.

In the heating section 124, the cylinder 162 is provided on the lower side of the molding chamber 106 with its piston rod 16
4 is inserted into the molding chamber 106, and is mounted on the casing 102. A mounting table 166 for mounting a molding material or a formed optical element is mounted on the upper end of the piston rod. ing. Above table 1
On the 66, for example, two mounting portions are arranged side by side in a direction perpendicular to the paper surface of FIG. 5 so that two molding materials or molded optical elements are mounted.

A heating cylinder 168 is disposed above the mounting table 166 in the heating section 124 in a state of being suspended by a support member 170. The cylindrical body 16
The lower end of No. 8 is open, and a heater 172 is attached to its inner peripheral surface. Then, the mounting table 166 is moved up and down from the position (the position shown in FIG. 5) immediately below where the suction means 150 arrives to the heating cylinder 1.
Up to a position within 68.

In the transfer section 126, a cylinder 182 is attached to the casing 102 below the molding chamber 106, and a rotary sleeve 186 is rotatably fitted to the piston rod 184 of the cylinder 182. The sleeve is
It is inserted through the wall of the casing 102 into the molding chamber 106, and is rotated by the driving means 192 provided on the piston rod 184. Further, in the molding chamber 16, the sleeve is provided with horizontally extending bifurcated arms 188a and 188b at the upper end thereof, and the suction means 19 are respectively attached to the tips of these arms.
0a and 190b are attached. One suction means 190
a corresponds to the press molding machine P ₁ and the other suction means 190 _b corresponds to the press molding machine P ₂ , and suction surfaces are provided on the lower surfaces of the suction means.

When the sleeve 186 is rotated, the suction means 190a is rotated based on the rotation of the sleeve 186.
6 from just above the upper end position to the position of the press molding machine P ₁ via the intermediate position shown in FIG. 6, and the rotation of the suction means 190b of the mounting table 166 is performed. It is performed from just above the upper end position to the position of the press molding machine P ₂ via the intermediate position shown in FIG.

In the press section 128, the fixed cylinder 202 extending in the vertical direction is fixed to the casing 102,
A cylinder 204 is attached to the lower end of the fixed cylinder 202 outside the molding chamber 106. To the piston rod of the cylinder 204, a lower shaft 206 that slides so as to be vertically movable with respect to the fixed cylinder 202 is connected.

At the upper end of the fixed cylinder 202, a cylindrical barrel-shaped member 210 is provided with a ring-shaped heater plate 208 interposed therebetween.
However, the lower end of the fixed cylinder 20 is suppressed by the ring 212.
2 is mounted in a state of being fixed to the lower shaft 206, and a lower mold member 214 is provided on the upper end of the lower shaft 206.
It is arranged in such a manner that it is slidable in the vertical direction in 10.

Further, the cylinder 222 is the same as the molding chamber 10 described above.
6 is attached to the casing 102, and the piston rod has an upper shaft 224 attached through the wall of the casing 102 and coaxially with the lower shaft 202. The lower end surface is formed in a convex spherical shape. A spherical seat 226 is in contact with the lower end of the upper shaft 224 so that the upper surface of the concave spherical shape corresponds to the convex spherical shape. The spherical seat 226 has a function of self-aligning at the time of pressing, and the upper end flange portion of the upper mold member 228 is disposed on the lower side thereof, and the upper end flange portion is the upper shaft 224.
It is locked by the retaining ring 230. The upper die member 228 is housed in the body die member 210, and can slide in the vertical direction with respect to the body die member 210.

The upper end surface of the lower mold member 214 and the lower end surface of the upper mold member 228 are transfer surfaces corresponding to the optical function surfaces of the optical elements to be molded, and are finished to a desired surface accuracy. ing. Further, in the lower shaft 206 and the upper shaft 224, the refrigerant flow paths C ₁ and C are respectively provided.
₂ are provided, and the heater plate 208, the body-shaped member 210, and the lower portion of the upper shaft 224 are each provided with a heater H.
₁ , H ₂ , H ₃ are built in. Further, in this embodiment, although not shown, the lower mold member 214 and the upper mold member 228 each have a built-in thermocouple for temperature detection.

Next, the operation of the above apparatus will be specifically described with reference to FIG. The molding chamber 106 is filled with a nitrogen atmosphere by a nitrogen gas supply system (not shown). At this time, the gate valves 110 and 112 are closed. Then, first, open the gate valve 112 (T
₀ ), two molding materials are placed on the placing table 138 at the lower position shown in FIG. 5, the placing table 138 is raised by the cylinder 132, and is introduced into the substitution chamber 108 through the gate valve 112. Yes (T ₁ ). The molding material is adsorbed by the adsorption section on the lower surface side of the adsorption unit 150 in the substitution chamber 138. The rotation position of the suction means 150 at this time is set to the “reference state”, and
The state rotated by 80 ° is referred to as an “inverted state”. The suction is performed by an air suction means (not shown).

Next, the mounting table 138 is lowered slightly, the transport shaft 148 is rotated 180 ° by the rotary cylinder 152, and the adsorption means 150 is turned upside down in the substitution chamber 108 (T ₂ ). As a result, the molding material is positioned on the upper surface side of the suction means 150. Next, the mounting table 138 is moved from the position in the replacement chamber 108 to the replacement chamber 10 described above.
8 Lower to the outside position (T ₃ ). Next, the gate valve 112 is closed (T ₄ ), the inside of the substitution chamber 108 is decompressed by the decompression means (not shown), and the molding material is preheated by the heater incorporated in the adsorption means 150.

Next, nitrogen gas is supplied into the substitution chamber 108 by the nitrogen gas supply system to fill the substitution chamber 108 with a nitrogen atmosphere, and then the gate valve 11 is operated.
Open 0 (T ₅ ). Then, the transfer shaft 148 is moved toward the molding chamber 106 by the cylinder 142, and the suction means 1 is moved.
50 to the position of the heating section 124 in the molding chamber 106 (T
₆ ).

The mounting table 166 is raised to the upper limit position by the cylinder 162 prior to the arrival of the suction means 150 (at the timing of T _a , for example), and further, within the heating cylinder 168 for an appropriate time ( T _a to T _b ) are arranged so that they are heated to an appropriate temperature,
Thereafter (before the timing T ₆ above), it is lowered to the position shown in FIG.

In this state, the rotation cylinder 152 works to rotate the transfer shaft 148 by 180 °, thereby vertically inverting the suction means 150 which has already reached above the mounting table 166 (T ₇ ). Then, the mounting table 166 is raised slightly to approach the lower surface of the suction means 150, and in this state, the suction by the suction means 150 is released, and the molding material is received on the mounting table 166. Therefore, since the mounting table 166 is heated in advance, when the molding material is placed on the mounting table 166, the material does not crack due to temperature shock.

Next, the mounting table 166 is lowered to the position (lower limit position) shown in FIG. 5, and then the transport shaft 148 is moved in the horizontal direction to retract the suction means 150 to the displacement chamber 108 (T ₈ ). In this state, the gate valve 11
Close 0 (T ₉ ).

The mounting table 166 on which the molding material is mounted is placed.
Is raised by the action of the cylinder 162 after the adsorption means 150 has retracted into the displacement chamber 108 (T ₈ ), and from then on, the gate valve 110 is closed (T ₉ ),
Placed in the heating cylinder 168 for an appropriate time (T _c to T _d ) within a time period until the next timing T ₁₀ (described later),
It is heated to an appropriate temperature.

Next, the rotation drive means 192 is used to rotate the arms 188a and 188b, and first, the suction means 19 is used.
0a is positioned above the mounting table 166 (T ₁₀ ), the mounting table 166 is slightly raised by the cylinder 162 of the heating unit, and the first molding material on the mounting table 166 is adsorbed by the adsorption means 190a. Again, the mounting table 166 is slightly lowered. Next, the arm 18 is rotated by the rotation driving means 192.
8a and 188b are rotated to move the suction means 190a to the first position.
To the press molding machine P ₁ (T ₁₁ ). here,
The molding material G ₁ sucked by the suction means 190a is
It is introduced into the inside of the body member through an opening 211 provided at the side of the body member 210, where the cylinder 1 of the transfer unit is
The suction means 190a is slightly lowered by 82, and the molding material is placed on the lower mold member 214.

On the other hand, the suction means 190b is moved to the _second press molding machine P ₂ at the same timing as the above T _10, and the suction means 190b is also moved at the same timing at T _11.
b is located above the mounting table 166. And T
₁₁ , the mounting table 16 is provided by the cylinder 162 of the heating unit.
6 is slightly moved up, the second molding material on the mounting table 166 is adsorbed by the adsorption means 190b, and the mounting table 166 is slightly lowered again.

Subsequently, the arms 188a and 188b are rotated to move the suction means 190b to the second press molding machine P.
Move to ₂ (T ₁₃ ). Here, as in the case of the first press molding machine P ₁ , the molding material adsorbed by the adsorbing means 190b is introduced into the body member through the opening provided on the side surface of the body member 210, Here, the suction means 190b is slightly lowered by the cylinder 182, and the molding material is placed on the lower mold member 214. next,
By rotating the arms 188a and 188b, the suction means 19
0b is returned to the intermediate position from the second press molding machine (T ₁₄ ). Incidentally, the adsorption unit 190a is positioned above the mounting table 166 in the T _13, it is returned to the middle position in the T _14. Thus, the state shown in FIG. 6 is obtained.

Next, the press section 28 (press molding machine P ₁ ,
In P ₂ ), press molding is performed. When the molding material G ₁ is introduced into the body mold member 210, the upper shaft 224 is pulled upward by the cylinder 222, which causes the upper mold member 228 to move upward in the body mold member 210. To the position, the opening 211 on the side of the barrel mold member communicates with the cavity in the mold member. Therefore, from here, the molding material G ₁ is placed in the cavity.
Can be introduced.

At the time of pressing, the upper shaft 224 is moved downward by the cylinder 222, the upper die member 228 closes the opening 211 of the body die member 210, and the cavity is closed. Further, when the upper mold member 228 is pressed downward, the molding material in the cavity is press-molded to form the optical element G ₂ . In addition, the upper mold member 228 finally moves downward until the lower end of the restraining ring 230 abuts the upper end of the body member 210.

Next, the press molding and the temperature change of the molded optical element after that will be described. FIG. 9 is a graph showing changes in temperature of the molding material and the molded optical element. Here, the temperature is shown in terms of the viscosity of the forming material glass.

The molding material is heated to a temperature close to the temperature at which it can be molded by the preheating, as described above, before reaching the press section 128. As the molding material,
It is preferable to use one having a shape corresponding to the shape of the optical element and having a surface roughness Rmax of 0.04 μm or less on the surface corresponding to the optical surface of the optical element. After accommodating the molding material in the mold, it is first heated by the heaters H ₁ , H ₂ and H ₃ . Then, the above molding material is subjected to, for example, a temperature (φ ₀ ) in a temperature range corresponding to a glass viscosity of 10 ⁹ to 10 ¹⁰ poise.
Heat and press mold. Pressing pressure by the upper mold member 228 is applied to the molding material from the time t _O, then the lower end of the presser ring 230 at time t _a is in contact with the upper end of the body mold member 110, at this stage, the molding of the optical element The product is molded into a predetermined size.

The temperature range corresponding to a glass viscosity of 10 ⁹ to 10 ¹⁰ poise is a temperature sufficient to realize good pressing. That is, within this temperature range, it is possible to prevent fusion between the glass and the mold member and to shorten the pressing time. In this pressing step, the temperature difference between the upper mold member 228 and the lower mold member 214 is preferably within 5 ° C. This is because if the temperature difference is too large, the amount of shrinkage between the upper surface and the lower surface of the molded optical element in the subsequent cooling step is different, and it becomes difficult to obtain good surface accuracy of the optical functional surface.

The cooling is performed at time t._a Started from
It During this cooling, the heater H ₁ , H₂ , H₃ By
Stop the heating,₁ , C₂ Refrigerant, for example
For example, flow cooling nitrogen gas.

FIG. 10 is a block diagram for explaining the manufacturing method of the present invention focusing on its control, and FIG. 11 is a flow chart of its operating procedure.

In this case, the hand driving means 200A is C
The operation of the cylinder 182 is controlled by a command from the control means 200 such as PU to drive the hand 190a. Further, the suction operation means 200B controls the suction operation of the hand 190a according to a command from the control means 200,
A signal indicating the completion of suction of the molded product by the hand 190a is fed back to the control means 200. Further, the mold opening / closing driving means 200C controls the operation of the cylinder 222 and the movement of the upper mold member 128 in accordance with a command from the control means 200.

The mold position detecting means 200D includes an upper mold member 128.
Is electrically connected to a position sensor 192 arranged corresponding to the outer circumference of the upper die member 128, and detects the position of a sensor dog (not shown) provided on the upper die member 128 to move the upper die member to the respective raised positions as described later. Control to move or stop. The position sensor 192 is a signal of a closed position in which the upper mold member 128 is closed with respect to the lower mold member, and when the upper mold member rises from the closed position, a molded product is a molding surface of the upper mold member 128. The signal of the first rising position for confirming whether or not it is adsorbed on the upper mold member is further lifted from the first rising position to open the mold, and the hand 190a is inserted into the mold.
The signal of the second rising position at the time of taking out the molded product,
Each is output, and via the mold position detecting means 200D,
It is sent to the control means 200.

The mold temperature control means 200E includes heaters H ₁ , H
₂ , controlling the energization of H ₃ and controlling the flow rate of the refrigerant to the refrigerant flow path, and also controlling the signal output of a temperature sensor (not shown) to heat the mold member and Performs cooling action.

The molded product position detecting means 200F is connected to the molded product position detecting sensor 194, and the upper die member 128 is the first
Is to detect the position of the molded product when it moves to the raised position of the upper mold member 128. When the upper mold member 128 moves to the first raised position, it is determined whether or not the molded product adheres to the molding surface of the upper mold. It serves to signalize and transmit to the control means 200. In this case, as the position detection sensor 194, for example, a light projecting and receiving type optical sensor is used to detect the presence / absence of a reflection signal when the molded product is attached to the upper mold, and thereby the molded product Check the adhesion. Further, reference numeral 200G denotes a means for detecting the posture of the molded product when the molded product remains on the molding surface of the lower mold member during molding, or when the molded product adheres to the upper mold member and then falls. Then, the attitude detecting means 200G includes attitude detecting sensors 196A, 1
96B (not shown) and 196C (not shown).

Attitude detection sensors 196A, 196B, 19
6C is composed of a light emitting / receiving sensor arranged on the outer periphery of the body member 210 at equal angular intervals of 120 °. The same light signal is emitted from the light emitting portion of each sensor, and the reflected light receiving signal is transmitted. The signal is input to the detection means 200G, the attitude state of the molded product is determined based on the strength of the signal, and a determination signal indicating whether or not the attitude of the molded product is a correct state that can be picked up by the hand is transmitted to the control means 200.

Next, the process steps of the operation will be described with reference to the flowchart of FIG.

First, the glass material and the mold member are heated. In this heating step, the heating cylinder 1
The glass material may be heated separately from the mold by 68, or may be placed in a mold member and heated together with the mold. The temperature of the mold member and the temperature of the glass material in the mold are controlled by the mold temperature control means 200E, in which the temperature is controlled to rise to a moldable temperature and the temperature is maintained thereafter (step 1). ..

The temperature of the mold member and the glass material is a predetermined temperature (φ
₀ ) and a stable state is reached (t ₀ ), a signal from the mold opening / closing drive means 200C causes the pressure cylinder 22
2 is operated to lower the upper mold member, close the mold, pressurize the glass material, transfer the shape of the molding surface of the mold member to the glass material, and mold the molded product into a desired shape ( Step 2).

Next, the mold temperature control means when the pressing time has elapsed (t _a) to start the cooling (step 3).

When the temperature (t ₄ ) at which the shape of the molded product becomes stable is reached, the process proceeds to the step of taking out the molded product. In the cooling step, when a signal indicating that the mold member has reached a predetermined cooling temperature is input from the mold temperature control means 200E to the control means 200, the control means 200 takes out the mold opening / closing drive means 200C. A signal for executing the process is output. From the mold opening / closing drive means 200C, a signal for raising the upper mold member in the closed state to the first raised position is output, and the height required for detecting the position of the molded product from the closed state of the upper mold member (first (Step 4). The first rising position of the upper mold member means that the molded product rises in a state where the molded product adheres to the upper mold member, is separated from the upper mold member in the middle of the rising, and falls toward the lower mold. Is high enough not to damage the sensor, and the sensor 19
This is the position in the mold open state in which sensing by 4 is possible.
In the range confirmed by us, it has been found that, in the case of a lens molded product, if the amount is equal to or less than the diameter of the lens, it does not damage the molding surface of the mold and the molded product, and the work result was good.

The movement control of the first rising position of the upper die member is performed by inputting the signal of the sensor 192 to the die position detecting means 200D. The control unit 20 is controlled by the movement signal from the mold position detection unit 200D to the first raised position.
From 0, an operation signal of the molded product position detecting means 200F is sent (step 5).

In the molded product position detecting means 200F, the sensor 194 detects whether the molded product is attached to the upper mold member. That is, the sensor actuating signal is output to the sensor 194 by the signal from the detecting means 200F, and the light projecting signal is output from the sensor 194. When the molded product is attached to the upper mold, the reflected light is detected by the light receiving element, and a light receiving signal is output from the light receiving element. When the molded product is not attached to the upper mold, the light receiving signal is not output (step 6). ).

When the control means determines that the molded product is not attached to the upper mold member based on the signal from the molded product position detecting means 200F, the molded product attitude detecting means 200G is subsequently operated. (Step 9). That is, the sensors 196A, 196B, 196 that form the attitude detection sensor.
The light-emission signal of C and the light-receiving signal obtained by the reflected light from the molded product are used as input signals, and the posture of the molded product on the molding surface of the lower mold member is determined by the hand or the suction hand based on the input signal. It is determined whether or not gripping with a gripping hand other than the above is possible (step 10).

When the posture of the molded product is detected and the posture is not good (it cannot be held by the hand), the warning means 200H is activated by a signal from the detecting means 200G (step 11).

When it is determined in the above-mentioned step whether or not the molded product adheres to the upper mold member, if the molded product adheres to the upper mold, the upper mold member is controlled by the mold temperature control means. By increasing the cooling rate of (1) (increasing the cooling gradient), the temperature difference between the molded product and the upper mold member is positively formed, and the mold release of the molded product is promoted (step 7). According to our experiments, regarding the adhesion to the upper mold member, after stopping the upper mold member at the first rising position, it takes several seconds (for example, 5
Since it has been confirmed that the molded product will fall within (after a second), the detection signal input by the molded product position detection means 200F is input to the time counting means 200, where the time sufficient for the fall is counted. After that, the upper mold member may be raised (step 8).

Further, in the above attitude determination, when the signal based on the situation that the attitude of the molded product is good is output from the molded product attitude detection means 200G, the mold opening / closing drive means 2
Send a signal to 00C to raise the upper die member further,
To the ascending position (step 12).

The detection of the second raised position of the upper die member is performed by inputting the signal of the position sensor 192 to the die position detecting means 200D. From the mold position detecting means 200D,
When a signal that the upper mold member has moved to the second raised position is output, the hand driving means is operated based on the output, and the hand is formed into an open space formed between the upper mold member and the lower mold member. , And then move the molded product onto the molded product. Then, the suction operation means is operated to perform the suction-removal operation of the molded product (steps 13 and 14).

In the description of the steps of the above-mentioned embodiment, the output signal of the molded product attitude detecting means 200G can be used as a confirmation signal of the presence / absence of the molded product. In this case, the mold cooling can be stopped by the confirmation signal. In addition, the confirmation signal, a start signal for starting the mold heating, and
By using it as a start signal for driving the hand, it is possible to shorten the cycle for taking out the molded product.

After such an operation, the above-mentioned press unit 1
First, the suction means 190a and 190b of the transfer section 126 are moved in the reverse order of the introduction of the molding material into the first and second transfer units.
The molded optical elements of the press molding machine P ₁ and the second press molding machine P ₂ are sucked and taken out, respectively, sequentially placed on the mounting table 166 of the heating unit 124, and finally the suction means 9
0a, 90b are placed in the intermediate position shown in FIG. 6 (T ₁₅ ~
T ₁₉ ).

In the process of press molding, that is, in the process of timings T ₁₄ to T ₁₅ , in order to heat the mounting table 166, the mounting table 166 is moved into the heating cylinder 168 by operating the cylinder 162. (T _e ), the cylinder 1 is heated to an appropriate temperature, and while the rotation driving means 192 is in the intermediate position, that is, before the timing T ₁₅ , the cylinder 1 is rotated.
By the operation of 62, the mounting table 166 is lowered (T _f ), and is held in a state of receiving the formed raw material. This is the same as the steps T _{a to} T _b described above.

The step of taking out the formed material after completion of the press forming is realized by overlapping with the step of taking in the press formed material described above. That is, after the suction means 150 has retracted into the substitution chamber 108, a new molding material is taken in in the same manner as at the timings T _{0 to} T ₆ (T
_{20 to} T ₂₆ ), and the timing T ₂₆ is the above timing T ₁₉
Is set to come after. Then, before the suction means 150 introduced into the heating unit 124 in the step of taking in the molding material returns from the reverse position to the reference position (T ₂₆
~ T ₂₇ ), on the empty surface (that is, the lower surface) of the adsorption means,
The formed material on the mounting table 166 is adsorbed. That is, when the suction means 150 reaches above the mounting table 166, the mounting table 166 is raised slightly, and the molded optical element on the mounting table is sucked by the lower suction part of the suction means 150, After slightly lowering the writing table 166, the suction means 150 is inverted (T ₂₇ ),
Next, the mounting table 166 is raised slightly, and the molding material adsorbed to the newly lower suction section is mounted on the mounting table 166.
put on top.

Then, as in the case of T _{8 to} T ₉ , the adsorbing means 150 is moved from the heating part 124 into the substitution chamber 108 (T ₂₈ ), and then the gate valve 110 is closed (T ₂₉ ).

As in the case of T _{c to} T _d described above, the mounting table 166 on which the molding material is mounted is lifted into the heating cylinder 168 by the cylinder 162 after T ₂₈ (T _g ), and is appropriately adjusted. After being heated to the temperature, the molding material 190a and 190b are respectively moved to the heating section 124 by the operation of the rotation driving means 192, and before the molding material is adsorbed from the mounting table 166, similarly, the cylinder 162 is also moved. Is lowered to the lower limit position (see Fig. 1) and stands by (T
_h ).

Hereinafter, the transfer section 126 and the press section 128
In, the same steps as those of T _{10 to} T ₁₉ are performed.

On the other hand, the gate valve 112 is opened (T ₃₀ ), and the mounting table 1 on which further new molding material is mounted is placed.
38 is raised (T ₃₁ ), and after adsorption by the lower adsorption part of the adsorption means 150 in the substitution chamber 108, the above-mentioned mounting table 1
38, the transport shaft 148 is rotated 180 degrees by the rotation motor 152, the suction means 150 is turned upside down (T ₃₂ ), and the mounting table 138 is raised slightly.
The molded optical element attracted to the newly lower attraction portion is placed on the placing table 138. Next, the mounting table 138 is lowered to the outside of the substitution chamber 108 (T ₃₃ ), and the gate valve 112 is closed (T ₃₄ ).

In this way, the molding material placed on the mounting table 138 is recovered as a molded product on the mounting table again through the above manufacturing process.

[0080]

The present invention has been described in detail above. When the mold member is opened in the step of heating the glass material, applying pressure, and taking out the molded product after the next step, the mold member is opened stepwise. Then, the position information of the molded product is detected, and the cooling process of the mold or the standby process for a predetermined time is provided according to the position information, which promotes the separation of the molded product from the upper mold member and damages the molded product. Can be prevented, and the defect rate of the molded product can be greatly improved.

Further, in the present invention, when the molded product is handled by mechanical means such as hand means, by providing a step of detecting the posture of the molded product before the operation of taking out the molded product, the molded product by the hand means is provided. Damage to the equipment, which can prevent equipment outages and promote automation.

In particular, in the present invention, the step of issuing a warning by the detection signal from the step of detecting the posture of the molded product is incorporated into the process of the present invention, whereby the occurrence of an accident in the apparatus can be prevented.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram for explaining an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram for explaining the above embodiment.

FIG. 3 is a schematic configuration diagram for explaining the above embodiment.

FIG. 4 is a schematic configuration diagram for explaining the above embodiment.

FIG. 5 is a schematic configuration diagram of another embodiment of the present invention.

FIG. 6 is a vertical side view of an example of an apparatus to which the manufacturing method of the present invention is applied.

FIG. 7 is likewise a cross-sectional plan view of a main part.

FIG. 8 is a time chart showing a manufacturing process of the present invention using the above apparatus.

FIG. 9 is likewise a timetable for temperature control.

FIG. 10 is a schematic configuration diagram for explaining control for realizing the manufacturing method of the present invention.

FIG. 11 is a flowchart showing a manufacturing process of the present invention using the above apparatus.

[Explanation of symbols]

 1 Upper mold member 2 Lower mold member 3 Glass material 4 Body 5 Heater 6 Molded product 7 Sensor 8 Adsorption band 9 Cooling passage

Claims (6)

[Claims] 1. A molding having a required optical function surface by housing a molding glass material between upper and lower mold members of a molding die, press-molding the material while heating it to a desired temperature, and then cooling and releasing the material. In a method of manufacturing an optical element adapted to manufacture a product, when the glass material is loaded between the upper and lower mold members, a heating step of heating the glass material and the mold member respectively, and the glass material at a glass molding temperature. A molding step of press-molding between the upper and lower mold members, then a cooling step of cooling the glass material together with the upper and lower mold members toward a temperature for taking out, and a step or the end of the cooling step, between the upper and lower mold members. It consists of a molded product unloading process in which the molded product is released and the molded product is taken out.
A step of detecting the positions of the molded products existing between the mold members with the upper and lower mold members opened by a predetermined amount, a process of fully opening the mold members based on the position detection result, and a process of taking out the molded products. A method for manufacturing an optical element, which comprises: 2. In the step of taking out the molded product, when the molded product adheres to the upper mold member at the time of mold release, the molded product is waited for taking out based on the result detected in the position detecting step, and the molded product is removed. The method of manufacturing an optical element according to claim 1, wherein the upper mold member is further raised by detecting that it has fallen onto the lower mold member. 3. In the step of taking out the molded product, when the molded product adheres to the upper mold member at the time of releasing the mold, the upper mold member is further cooled based on the result detected in the position detecting process. The method for manufacturing an optical element according to claim 2, wherein 4. The position detecting step includes a step of confirming that a molded product adheres to the upper mold member, and a step of confirming the subsequent drop of the molded product. The method for manufacturing an optical element according to claim 2. 5. A molding having a required optical function surface by containing a molding glass material between upper and lower mold members of a molding die, press-molding the material while heating it to a desired temperature, and then cooling and releasing it. In a method of manufacturing an optical element adapted to manufacture a product, when the glass material is loaded between the upper and lower mold members, a heating step of heating the glass material and the mold member, and the glass material at a glass molding temperature. A molding step of press-molding between the upper and lower mold members, then a cooling step of cooling the glass material together with the upper and lower mold members toward a temperature for taking out, and a step or the end of the cooling step, between the upper and lower mold members. It consists of a molded product unloading process in which the molded product is released and the molded product is taken out.
A step of determining the postures of the molded products existing between the mold members in a state where the upper and lower mold members are opened by a predetermined amount, a process of fully opening the mold members based on the posture determination result, and a process of taking out the molded products. A method of manufacturing an optical element, which comprises: 6. The method of manufacturing an optical element according to claim 5, wherein the cooling step is terminated after the attitude of the molded product is confirmed in the attitude determination step.