JP2833683B2 - Optical element molding method and molding apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming an optical element for processing a high-precision optical element such as an aspherical lens, comprising a pair of upper and lower mold members for pressing heat-softened glass. It relates to a molding device.

[0002]

2. Description of the Related Art In recent years, attention has been paid to a method of press-molding a heat-softened glass material using a pair of upper and lower mold members instead of a processing method by grinding and polishing.

[0003] Usually, this type of molding was first carried out by the method described below. That is, first, a molding material such as glass, which is formed in a shape close to the final shape of the optical element in advance, is placed between the lower mold and the upper mold, and this is put into a heating furnace sealed in a nitrogen atmosphere. . Then, when the material is heated to a temperature at which it can be molded, press molding is performed, and the completed mold is cooled in a furnace. When the mold is cooled to a temperature at which the mold does not oxidize, the molded product is transferred from the furnace in a nitrogen atmosphere to the atmosphere. With the mold. However, in this method, the running cost increases because the molding time is long.

Therefore, in order to shorten the molding time, a method of removing a molded product from a mold in a furnace in a nitrogen atmosphere at a considerably high temperature has been adopted. This method will be described with reference to FIGS. This apparatus includes a molding chamber 112 in a nitrogen atmosphere and a substitution chamber 113 capable of replacing the atmosphere with air / nitrogen. The substitution chamber 113 is opened and closed by a gate valve (not shown), and the molding chamber 112 and the replacement chamber 113 are opened and closed. It is designed to communicate with the outside air space. The molding material 104 is placed at the upper end of the supply shaft 114 in the replacement chamber 113 from outside the apparatus, and the supply shaft 114 rises into the molding chamber 112, so that the upper surface of the molding finger 104 contacts the suction finger 105. A suction pipe 106 is connected to the suction finger 105, and a negative pressure is applied to the suction finger 105 through the suction pipe, whereby the molding material 104 is suctioned to the suction finger 105. Next, a rotating shaft 115 supporting the suction finger 105
Is rotated, the suction finger 105 passes through the opening 119 of the body mold 103, and the upper mold 102 and the lower mold 101
The molding material 104 is moved to a position between. At this position, the suction force on the molding material 104 is released, and this is placed on the high temperature lower mold 101, and the upper mold 102 is pushed by the ram 116,
Press molding is performed. Then, when the temperature of the molded product becomes equal to or lower than the glass transition temperature, the upper mold 102 is raised, and the molded product is taken out of the apparatus at a considerably high temperature in the reverse order of the process of inserting the molding material.

In order to take out the molded product by such a method, it is necessary that the molded product remains on the lower die 101 so that the suction finger can reliably suck the upper die 102 when the upper die 102 is lifted. .

[0006]

However, when the molding is completed, the optical surface of the molded product and the molding surface (mirror surface) of the molding die member corresponding thereto come into contact with each other in a state where the adhesive force acts between them. This contact state is substantially the same for the lower mold member 101 and the upper mold member 102, respectively. For this,
After press molding, the upper mold member 1
02 is raised, as shown in FIG.
A so-called upper mold adhesion phenomenon may occur in which the 04 adheres to the molding surface of the upper mold member 102 in a state of being in contact with the upper mold member 102. When the upper die adhesion phenomenon occurs, the molded article 104 cannot be removed by suction with the suction finger 105. Therefore, when the upper mold adhesion phenomenon occurs, continuous molding with the molding die is stopped and waited while the molded article 104 is dropped from the upper mold member 102 and dropped on the lower mold member 101. is there. For this reason, when the upper die adhesion phenomenon occurs, the operating rate of the molding apparatus is significantly reduced.

As a problem when the upper mold adhesion phenomenon occurs, if the above-mentioned standby time is not provided, the molded article 104 is adhered to the upper mold member 102 while the molded article 104 is adhered. Since the suction finger 105 comes into contact with the glass mold 104, the glass molded article 104 is crushed,
If the molded article that has fallen from 2 does not fall well to the center position of the lower mold member 101, it becomes difficult to attract the molded article 104 by the suction finger 105 in the removal stage, and When the article 104 falls, the glass is crushed, which may damage the molding surface of the lower mold member.

In addition to the above-mentioned problem, there is a problem that it is difficult to distinguish between the front and back surfaces of a normal biconvex lens, a biconcave lens, and the like having relatively close radii of curvature on both surfaces.

Accordingly, the present invention has been made in view of the above-mentioned problems, and a first object of the present invention is to provide a method in which, when the upper mold is lifted, the upper mold member is preferentially peeled off from the molded product, and the upper mold member is removed. An object of the present invention is to provide an optical element molding apparatus in which an article remains on a lower mold member.

A second object of the present invention is that when the upper mold is lifted, the upper mold member is preferentially peeled off from the molded article, and the center position of the molded article is shifted to the center position of the lower mold member. An object of the present invention is to provide a method for molding an optical element that is left on a lower mold member without causing deviation.

[0011]

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems and achieve the object, an optical element molding method according to the present invention is a method for molding an optical element such as a lens. A glass material is inserted between an upper mold and a lower mold having a molding transfer surface for molding the optical functional surface of the optical element, at least heating the glass material to a molding temperature,
An optical element molding method for molding an optical element by pressing the glass material heated by the upper mold and the lower mold to transfer the surface shape of the molding transfer surface of the upper mold and the lower mold. Engaging means for engaging a part of the outer peripheral portion of the optical element, the engaging means interlocking with the pressing operation of the glass material inserted between the upper mold and the lower mold, and According to the end of the molding of the glass material by the closing operation of the lower mold,
The engaging member of the engaging means is kept in an engaged state with the molded optical element, and is not engaged with the engaging means on the outer peripheral portion of the glass material during the pressing operation of the glass material. It is characterized in that parts are not restrained.

Further, in the method of molding an optical element according to the present invention, the molded optical element is held by the engaging member during the mold opening operation after the closing operation of the upper mold and the lower mold is completed.
It is characterized in that it is left in one mold and is released from the other mold.

Further, the method of molding an optical element according to the present invention is a method of molding an optical element for molding an optical element such as a lens, the method comprising: transferring a glass material to a molding transfer surface for molding an optical functional surface of the optical element. Inserted between an upper mold and a lower mold, at least heating the glass material to a molding temperature,
An optical element molding method for molding an optical element by pressing the glass material heated by the upper mold and the lower mold to transfer the surface shape of the molding transfer surface of the upper mold and the lower mold, wherein the upper mold Providing engagement means for engaging the glass material inserted between the lower molds, prior to the closing operation of the upper mold and the lower mold, or interlocking with the closing operation, the engaging means After contacting the glass material and holding the glass material at predetermined positions of the upper mold and the lower mold, by the upper mold and the lower mold,
An optical element is formed by changing the shape of a glass material.

Further, in the optical element molding apparatus according to the present invention, a glass material is inserted between an upper mold and a lower mold having a molding transfer surface for molding an optical functional surface of the optical element. An optical element for molding an optical element by heating the glass material heated by the upper mold and the lower mold to transfer the surface shape of the molding transfer surface of the upper mold and the lower mold to a molding temperature. A molding die comprising the upper die and the lower die, wherein the molding die is configured not to restrain the outer peripheral portion of the glass material during the pressing operation of the glass material. Engaging means for engaging a part of the outer peripheral portion of the optical element, the engaging means interlocked with the pressing operation of the glass material inserted between the upper mold and the lower mold,
And a driving means for driving the engaging means in accordance with the deformation of the glass material by the closing operation of the upper mold and the lower mold.

In the apparatus for molding an optical element according to the present invention, the driving means is operated by an inert gas.

Further, the apparatus for molding an optical element according to the present invention presses a glass material which has been softened by heating to form a molding surface for transferring a predetermined shape onto the surface of the glass material. An optical element molding apparatus comprising a plurality of pairs of upper and lower mold members having a pair of upper and lower mold members, wherein the molding die includes the plurality of pairs of mold members, and the outer peripheral portion of the glass material is not restrained during the pressing operation of the glass material. And a positioning surface that is provided corresponding to each of the plurality of pairs of upper and lower mold members and abuts against a side surface of a lower mold member of the upper and lower mold members, and the positioning surface is the positioning surface. A plurality of outer peripheral molding members having an outer peripheral molding portion projecting from the molding surface along a substantially horizontal direction at a portion along the horizontal direction in a state of being in contact with the side surface of the lower mold member; Hold in batch Holding member, driving means for moving the holding member forward and backward along the direction normal to the center axis of the molding surface, and elastically moving the plurality of outer peripheral molding members independently of the holding member. And a plurality of elastic support means for urging the outer peripheral forming member in a direction in which the positioning surface contacts the side surface of the lower mold member.

In the apparatus for molding an optical element according to the present invention, the urging force of the elastic supporting means for urging the positioning surface in a direction in which the positioning surface is brought into contact with the side surface of the lower mold member is as follows. In the process of being pressed and spread on the molding surface, the outer peripheral molding portion of the outer peripheral molding member balances the viscosity of the glass material,
It is characterized in that it is set to such a value that it penetrates the outer periphery of the glass material by an optimum amount.

Further, in the optical element molding apparatus according to the present invention, the molding of the upper mold member of the upper and lower mold members is completed with the outer peripheral molding portion biting into the outer peripheral portion of the glass material. The glass material is left on the lower mold member by separating the glass material from the glass material.

Further, in the optical element molding apparatus according to the present invention, the outer peripheral molding member may be moved relative to the holding member by the elastic supporting means such that parallel movement and rotational movement are allowed in a vertical plane and a horizontal plane. It is characterized by being supported.

Further, in the optical element molding apparatus according to the present invention, the glass material is formed in a shape close to the completed shape of the optical element or in a flat plate shape, and the center axis of the glass material is the molding surface. Is positioned by the outer peripheral forming member and a fixed positioning member disposed to face the outer peripheral forming member so as to substantially coincide with the center axis of the outer peripheral forming member.

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

As described above, since the present invention is constituted,
The outer peripheral molding portion of the outer peripheral molding member is protruded by a predetermined amount above the molding surface, and the glass material is press-molded in this state, whereby the outer peripheral molding portion bites into the outer peripheral portion of the glass material that has been spread on the molding surface. When the upper mold member is pulled up in a state where the outer peripheral molding portion has cut into the outer peripheral portion of the glass material, the glass material is held by the outer peripheral molding portion and adheres to the lower mold member. , And only the upper mold member is separated from the glass material.

Further, the portion of the optical element which the outer peripheral molding bites into serves as an identification mark for discriminating the front and back of the optical element, so that the front and back of the optical element can be easily discriminated.

[0030]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. (First Embodiment) FIG. 1 is a diagram showing a configuration of an optical element molding apparatus 10 according to a first embodiment. FIG. 1 shows a state where the upper die member is completely lowered and the pressing operation is completed.

In FIG. 1, a molding die 12 constituting a main part of the molding device 10 is mounted on a molding device main body 8. The outer shell of the molding die 12 is constituted by a body die 14. The body mold 14 is formed in a substantially square prism shape in a top view, and through holes 14a and 14b are formed on the center axis of the body mold 14 so as to penetrate the body mold 14 up and down. An upper mold member 16 formed in a columnar shape is slidably inserted in the upper through-hole 14a of these through-holes along the up-down direction in a fitted state. A disk-shaped flange portion 16a is formed at an upper end portion of the upper die member 16, and the lower surface of the flange portion 16a contacts the upper surface 14c of the body die 14 from above, whereby the upper die 16 is formed.
Is prevented from moving further downward, thereby defining a downward press stroke of the upper die member 16. On the lower surface of the upper die member 16, a molding surface 16b for pressing the glass material 40 to transfer a desired shape to the surface to form an optical function surface is formed.

On the other hand, a lower mold member 18 formed in a columnar shape like the upper mold member 16 is inserted into the lower through hole 14b in a fitted state. Lower surface 18a of lower mold member 18
Is in contact with the upper surface of a supporting substrate 20 on which the body mold 14 is placed, and the downward pressing pressure applied to the lower molding member 18 from the upper molding member 16 via the glass material 40 by the supporting substrate 20. It is configured to receive. Lower mold member 1
On the upper end surface of 8, a forming surface 18b for transferring a desired shape to the lower surface of the glass material 40 to form an optical function surface is formed. Therefore, on the upper surface of the glass material 40, the optical function surface 40a to which the surface shape of the molding surface 16b of the upper mold member 16 is transferred is formed, and on the lower surface, the surface shape of the molding surface 18b of the lower mold member 18 is formed. Is transferred to the optical function surface 40b.

Further, a molded lens (glass material 4
As described above, the thickness of 0) is defined by the lower surface of the flange portion 16a of the upper die member 16 abutting on the upper surface 14c of the body die 14, and the thickness of the lens (40) does not change every time processing is performed. It has been done.

On the other hand, in the body mold 14, the body mold 14, the upper mold member 16, and the lower mold member 18 are positioned in the four corners.
And a heater 26 for heating the glass material 40 via the body mold 14, the upper mold member 16, and the lower mold member 18.

An opening hole 14e is formed on the side of the body mold 14.
Is formed, the glass material 40 is supplied into the molding die 12 through the opening hole 14e, and the lens (40) whose molding has been completed is taken out from the interior of the molding die 12.

The cross-sectional shape of the opening 14d is circular, and its inner surface is finished to a smooth surface. As will be described later in detail, an outer peripheral forming member 28 is slidably inserted into the opening hole 14d with a slight gap.

This outer peripheral forming member 28 is shown in FIGS.
As shown in FIG. 2, which is a sectional view taken along the line AA in FIG. 2, a cylindrical main body 28a slidably inserted into the opening hole 14d.
And a positioning surface 28b formed near the tip of the main body 28a and abutting against the outer surface 18c of the lower mold member 18, and an outer peripheral molding 28c protruding substantially horizontally on the molding surface 18b. ing. In addition, the outer peripheral forming portion 28c
Is formed in an arc shape having a curvature close to the outer peripheral shape of the completed optical element, that is, the lens (40), as shown in FIG.

Here, the outer peripheral forming member 28, which is a characteristic part of the present embodiment, and a device for driving the outer peripheral forming member 28 will be briefly described.
The compression spring 32 is supported by a support device 30 for supporting the
Is supported through. Therefore, the outer peripheral forming member 28
Is urged by a compression spring 32 in a direction toward the central axis of the upper and lower mold members 16 and 18. The driving device 34 of the outer peripheral forming member 28 is connected to the rear of the support device 30 via a connecting rod 34a. The connecting rod 34a is
The outer peripheral forming member 28 is held by the driving device 34 so as to be pushed and pulled in the direction indicated by the arrow B in the drawing, and the connection rod 34a moves in the direction of the arrow B.
Are driven in a direction of being inserted into the barrel mold 14 via the support device 30 and in a direction of being pulled out. The outer peripheral forming member 28, the supporting device 30, and the driving device 34 are respectively arranged at positions facing each other with respect to the body mold 14, as shown in FIGS. The configuration of
It is symmetrical with the configuration on the right side in the figure.

Next, the molding apparatus 10 configured as described above
The procedure for molding the lens (40) will be described with reference to FIGS.

First, as shown in FIG. 3, the upper die member 16 is slid upward with respect to the body die 14 by a driving device (not shown), and is released from the lower die member 18. In this state, the glass material 40 heated to a predetermined high temperature is supplied onto the molding surface 18b of the lower mold member 18 through an opening hole 14e of the body mold 14 by an automatic hand or the like. When forming the convex lens, the glass material 40 supplied at this time is formed into a spherical shape as shown in the figure or a shape close to the completed shape of the convex lens.
Further, the body mold 14, the upper mold member 16 and the lower mold member 18
It is heated to a temperature corresponding to predetermined molding conditions. When supplying the glass material 40 into the body mold 14,
The outer peripheral forming member 28 is driven by the driving device 34 (see FIG. 1).
The glass material 40 is retracted to the outside of the body mold 14 so as not to prevent the glass material 40 from being inserted into the body mold 14.

After the glass material 40 is supplied onto the molding surface 18b of the lower mold member 18, the driving device 34 moves the outer peripheral molding member 28 in the direction of entering the body mold 14. At this time, the driving device 34 moves the support device 30 in the direction approaching the lower mold member 18 slightly more than the position where the positioning surface 28b of the outer peripheral forming member 28 contacts the outer surface 18c of the lower mold member 18. , Positioning surface 2 of outer peripheral forming member 28
8b is elastically formed by the lower spring member 1 by the spring force of the compression spring 32.
8 so as to contact the outer surface 18c. This allows
This means that the outer peripheral forming member 28 has been set to the predetermined operation position.

In this state, as shown in FIG. 4, the distal end portion 28d of the outer peripheral forming portion 28c is located at a position in contact with the circumference having a diameter D1 about the center axis of the lower die member 18.
In this embodiment, if the outer diameter of the completed lens is D0 (see FIG. 5), the value of the diameter D1 is 0 <
(D0-D1) / 2 = x <2 mm.

Thereafter, the upper mold member 16 is moved downward by a driving device (not shown) so that the upper surface of the glass material 40 is brought into contact with the molding surface 16 b of the upper mold member 16, and a pressing pressure is applied to the glass material 40. Let it. When the press pressure is applied and the upper mold member 16 gradually moves downward, the glass material 40
Are substantially uniformly spread in the outer peripheral direction and deformed, and at some point during the pressing operation, the outer peripheral portion of the glass material 40 comes into contact with the distal end portion 28d of the outer peripheral forming portion 28c.

When the upper mold member 16 is further pushed down, the outer peripheral forming member 28 is pressed against the urging force of the compression spring 32 by the deforming force of the glass material 40 in the outer peripheral direction.
4 so as to be pushed out. At this time, when the outer peripheral forming member 28 is pushed out of the body die 14, the compression spring 32 is further compressed and the urging force is strengthened with an increase in the amount of the extruded member.
In a state where the deformation force of the outer peripheral molding member 28 is
Is pushed by the glass material 40 and moves. Finally, the state is as shown in FIG. At this point, in a state where the deformation force of the glass material 40 and the urging force of the compression spring 32 are balanced, the outer peripheral forming portion 28c bites into the side surface of the glass material 40 by an amount indicated by δ in the drawing. By making the outer peripheral forming member 28 bite into the glass material 40 in this manner, the glass material 40 is surely separated from the upper mold member 16 in the subsequent releasing step, and the lower mold member 18 is removed.
You can leave it on.

In the case where the outer peripheral forming portion 28c is cut into the side surface of the glass material 40 for forming, if the biting amount δ increases, the coefficient of thermal expansion of the glass is larger than the coefficient of thermal expansion of the mold member. Cooling lens (40)
Cracks may occur. Further, as described later, when the outer peripheral forming member 28 is separated from the outer peripheral portion of the lens (40), the release resistance thereof becomes excessive, and cracks and chips may occur in the lens (40). Therefore, it is necessary to prevent the amount of penetration δ of the outer peripheral forming member 28 into the lens (40) from becoming excessive.

As the method, in this embodiment,
As described above, the outer peripheral forming member 28 is urged inward by the compression spring 32, and the urging force and the deformation force of the glass material 40 are balanced to adjust the biting amount δ. That is, the optimal bite amount δ into the glass material 40
Thus, the initial spring force of the compression spring 32 and the spring constant are set so as to obtain.

For example, when optical glass SK12 (manufactured by OHARA Co., Ltd.) is used as the glass material 40 and a double-sided convex lens having an outer diameter of 15 is molded, the outer peripheral bite molding is performed under the following conditions (see also FIG. 6 at the same time). In this case, it has been confirmed that the bite amount δ does not become excessive.

(Conditions) Shape of the tip of the outer peripheral molding member: width 14 mm, vertical thickness 0.6
mm Tip R7.3mm (from the center of the lower mold member) Arc shape Lens (molded product) shape: outer diameter φ15mm, wall thickness 4.5m
m Upper surface sphere R16.1 mm, lower surface sphere R16.9 mm Initial elastic force of compression spring: 0.3 kgf Displacement of outer formed member Δx = 0.8 mm Spring constant k = 0.1 kgf / mm Elastic force generated during deformation 0.08 kgf Mold member forming temperature: 620 ° C Lower mold member forming temperature: 640 ° C Viscosity of glass: 10 ⁹ to 10 ¹⁰ P (poise) Next, as shown in FIG. Cool the lens (40). Then, when the temperature of the lens (40) becomes lower than the glass transition temperature, the upper mold member 16 is raised to open the mold. At this time, as shown in FIG.
The upper mold member 16 is lifted in a state where the upper mold member 16 has been bitten. Thus, the outer peripheral forming member 28 is connected to the lens (4
If the upper mold member 16 is lifted while it is still biting into the upper mold member 0, the lens (40) is reliably pressed away from the upper mold member 16 because the lens (40) is pressed by the outer peripheral molding member 28. The mold release is performed in a state of being attached to the mold member 18. As described above, since the lens (40) is reliably left on the lower mold member 18, the barrel mold 1 by an automatic hand or the like is formed.
The removal of the lens (40) from the inside of the lens 4 is quickly performed.

Thereafter, as shown in FIG. 7, the outer peripheral forming member 28 is driven by the driving device 34 in a direction away from the lens (40), and the outer peripheral forming member 28 is moved to the lens (40).
Pulled away from. Then, the outer peripheral forming member 28 is further moved by the driving device 34 in a direction of being pulled out from the body mold 14 and retracted to the outside of the body mold 14. The molded lens (40) is taken out through the opening 14e of the body mold 14 by an automatic hand or the like.

FIG. 8 shows the value of the bite amount δ when bite molding was performed under various molding conditions different from the above-mentioned conditions. However, the tip shape of the outer peripheral forming member 28 and the curvature of the upper and lower surfaces of the lens (40) are the same as those described above. According to FIG. 8, the spring constant k of the compression spring 32 is k =
In the case of 0.05 kg / mm, the frequency of occurrence of an uncut portion in the outer peripheral portion of the lens (40) is as high as about 50%, and there is a possibility that the restraining force at the time of releasing the mold is not stably secured. Also,
When k = 0.2 kg / mm, the bite amount δ at the outer peripheral portion of the lens (40) is relatively large, and there is a problem in interference with the effective diameter of the optical function portion of the lens (40). Also,
When the outer peripheral molding member 28 and the lens (40) are released from the mold, the release resistance is increased, and it is expected that the lens (40) may be cracked or chipped. Therefore, under the molding conditions of this embodiment, the spring constant k of the compression spring 32 is 0.1 kg / m.
m is considered optimal.

In the above embodiment, the case where the outer peripheral forming members 28 are arranged one by one on both sides of the lower mold member 18 has been described. However, the outer peripheral forming members 28 are arranged only in one direction on one side. It has been confirmed that a similar effect can be obtained even in this case. Thus, the configuration of the outer peripheral forming member of the above-described embodiment can be applied to multi-cavity molding in which a number of upper and lower mold members 16 and 18 are arranged in the body mold 14.

Next, the structure of the outer peripheral forming member 28 and the supporting device 30 for supporting the outer peripheral forming member 28 will be described in more detail.

By the method described above, the lens (40)
When press molding, it is necessary to heat the body mold 14 and the upper and lower mold members 16 and 18 to a considerably high temperature, and to cool the temperature to a low temperature of about room temperature. Therefore, in this embodiment, the body mold 14 and the outer peripheral molding member 28 are made of a material having substantially the same coefficient of thermal expansion, and the sliding of the outer peripheral molding member 28 in and out of the body mold 14 is facilitated. A predetermined clearance is provided between the outer peripheral surface of the outer peripheral molding member main body 28a and the inner peripheral surface of the opening hole 14d.

Here, when the outer peripheral forming member 28 is slid inward and outward relative to the body mold 14, unless the driving force acts on the central axis of the outer peripheral forming member main body 28a, the outer peripheral molding member 28a must be slid. The member 28 tilts in the opening hole 14d, and causes razing with the body mold 14, which may cause damage to the body mold 14 and the outer peripheral molding member 28, which may prevent continuous molding.

For this reason, in this embodiment, the structure of the supporting device 30 for supporting the outer peripheral forming member 28 is devised so that the driving force from the driving device 34 always generates the outer peripheral forming member main body 28.
Work along the central axis of Hereinafter, the configuration of the support device 30 will be described.

Here, since a part of the outer peripheral forming member 28 also functions as a part of the support device 30, the structure of the outer peripheral forming member 28 will be described again with reference to FIG.

As described above, the outer peripheral forming member 28b has an arc-shaped outer peripheral forming portion 28b and a positioning surface 28c which is in contact with the outer surface 18c of the lower mold member 18, at the distal end thereof. On the other hand, behind the outer peripheral forming member 28, a cylindrical concave portion 28d is formed coaxially with the central axis 28g of the cylindrical outer peripheral forming member main body 28a. The compression spring 32 described above is inserted into the cylindrical recess 28d. Then, one end of the compression spring 32 presses the bottom surface 28e of the concave portion 28d, so that the outer peripheral forming member 28 is
It is urged toward the central axis of the lower mold member 18. Here, the central axis of the cylindrical concave portion 28d is the outer peripheral molded member main body 28a.
And the bottom surface 28e of the concave portion 28d is orthogonal to the central axis 28g, so that the urging force of the compression spring 32 is applied to the outer peripheral forming member 28 with respect to its center. It will work along axis 28g.

On both sides of the rear end of the outer peripheral forming member 28, a shaft member 28f is mounted with its central axis orthogonal to the sliding central axis 28g. on the other hand,
As shown in FIGS. 10 and 11, the support device 30 includes an alignment member 42 that supports the shaft member 28f, and a support device main body 44 that supports the alignment member 42. The support device main body 44 is connected to the connection rod 34a of the driving device 34 described above.

The centering member 42 is formed in a rectangular shape when viewed from the front, and a hook 42a for hooking the shaft member 28f of the outer peripheral forming member 28 is formed in front of the centering member 42. The outer peripheral forming member 28 holds the shaft member 28f in the engaging portion 42a, so that the compression spring 3
2 is prevented from falling off from the support device main body 44 due to the spring force. A through hole 42d for passing the compression spring 32 is formed in the center of the centering member 42.

On the upper and lower sides of the alignment member 42, the outer peripheral molding member 2 is provided.
A substantially cylindrical projection 42c having a central axis perpendicular to the vertical direction is formed on the sliding central axis 28g of No.8. And
The projecting portion 42c is provided with a hook 44a of the support device body 44.
Is in contact with The contact force is determined by the direction in which the compression spring 32 separates the outer peripheral forming member 28 from the support device main body 44 (arrow B).
Direction), and the urging force is generated by transmission of the urging force to the engaging portion 42a via the shaft member 28f.

With such a configuration, the outer peripheral forming member 28
The alignment member 42 is supported by the support member main body 44 by the urging force of the compression spring 32. Further, in such a configuration, since the alignment member 42 is in line contact with the engaging portion 44a of the support member main body 44 at the projection 42c, the centering member 42 is horizontally supported by the contact line 42b as a fulcrum. It is possible to swing in the direction. And contact line 4
Since 2b is perpendicular to the sliding center shaft 28b in the vertical direction, the outer peripheral forming member 28 can swing right and left around the sliding center shaft 28g. In addition, since a predetermined clearance is provided between the outer shape of the alignment member 42 and the inner shape of the support member main body 44, the alignment member 42 can move in the vertical and horizontal directions with respect to the support member main body 44. It is possible.

Further, the outer peripheral forming member 28 is
In contrast, since the outer peripheral forming member 28 is supported via the shaft member 28f, the outer peripheral forming member 28 can swing up and down with respect to the alignment member 42, and can also move up and down and left and right. It is possible. Therefore, the outer peripheral forming member 28
Is slidable in the up-down and left-right directions and swingable in the up-down and left-right directions with respect to the support member main body 44, and the biasing force of the compression spring is applied to the sliding center axis of the outer peripheral forming member 28. The support member main body 44 is moved by the driving device 34 in the vertical and horizontal directions (due to thermal deformation, displacement of the processing jig, and the like) with respect to the sliding center shaft 28g. Even if the outer peripheral molding member 2
8, a driving force always acts along the sliding center axis 28g. Accordingly, the outer peripheral forming member 28 is
Can smoothly enter and exit along the opening hole 14d, thereby preventing occurrence of galling defects, scratches, and the like. FIG. 12 shows the positioning surface 2 of the outer peripheral forming member 28.
FIG. 8C is a view showing a state in which the compression spring 32 is compressed, and the outer peripheral forming member 28 is freely supported only by the compression spring 32, when the compression spring 32 is in contact with the outer surface 18 c of the lower mold member 18.

As described above, according to this embodiment,
By molding the lens in a state where the outer peripheral molding member is cut into the outer peripheral portion of the glass material, it is possible to reliably prevent the upper die from attaching to the upper die member when the mold is released.

Further, since the outer peripheral forming member is supported by the supporting device so as to be slidable in the vertical and horizontal directions and swingable in the vertical and horizontal directions, the outer peripheral forming member is always inserted into and out of the body mold. Since the outer peripheral forming member can slide back and forth along the center axis of sliding with the body mold, it is possible to smoothly enter and exit without generating galling and the like. (Second Embodiment) In the second embodiment, the glass material before molding is positioned by the outer peripheral molding member.

The second embodiment will be described with reference to FIGS. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

When the glass material 40 is pressed by using the upper mold member 16 and the lower mold member 18 to form an optical element, the glass material 40 should be positioned so that the center axis of the glass material 40 becomes the center axis of the lower mold member 18. It is desirable to place it on the lower mold member 18 so that it exactly matches. This is because when the glass material 40 is pressed in a state shifted from the center of the lower mold member 18,
An outer peripheral shape defect due to the occurrence of an unfilled portion in the outer peripheral portion of the lens (residual residue after the lens centering process occurs) or an upper and lower mold member due to an uneven load applied to the upper and lower mold members 16 and 18 This is because there is a risk of causing galling between the 16, 18 and the trunk mold 14 to cause a trouble in stopping the apparatus.

Here, for example, the molding surface 1 of the lower mold member 18
When the spherical glass material 40 is used, and the glass material is naturally placed at the center of the lower mold member 18 due to its centripetal effect, otherwise, for example, the molding surface of the lower mold member 18b Is a convex type, and when a concave lens is formed, a concave glass material or a flat glass material is placed on the lower mold member 18, so that the positioning of the glass material 40 is required. Become.

The lower member 18 of such a glass material 40
When performing the upward positioning, for example, the glass material 4
Positioning may be performed using an outer ring having an outer diameter larger than the outer diameter of 0, or a method of fixing and supporting the outer peripheral surface of the glass material 40 at three points. However, in the positioning method using the outer ring, the clearance between the inner diameter portion of the ring and the outer diameter portion of the glass material 40 always causes a deviation during molding. Further, in the case of the outer peripheral abutment by the fixing jig, the applied impact varies depending on the variation of the blank outer diameter dimension, and depending on the accuracy of placing the glass material 40 on the lower mold member 18, the impact may be one-sided with the fixed positioning member. There are cases. In the case of such a one-sided contact, the glass material may fall from the lower mold member, or the glass material may be cracked or chipped.

For the reasons described above, in this embodiment, the positioning of the glass material is performed by the following method.

13 and 14, a fixed positioning member 50 is disposed at a position facing the outer peripheral forming member 28. Outer peripheral molding member 28 of fixed positioning member 50
The surface opposed to is finished with high precision and serves as a positioning surface 50 a of the glass material 40. The fixed positioning member 50 is connected to a driving device (not shown),
It is driven in the vertical direction in the figure by this driving device. The illustrated position is a position at which the fixed positioning member 50 actually executes the positioning of the glass material 40, and the positioning surface 50 a is positioned from the center axis of the lower mold member 18 to the glass material 4.
It is located at a position exactly the same distance as the radius of 0 or at a position slightly greater than the radius of the glass material 40.

After the positioning of the glass material 40 is completed, the fixed positioning member 50 is retracted leftward in the drawing so as not to hinder the actual pressing operation. At this retracted position, the positioning surface 50a is connected to the lens (4
It escapes outside the outer diameter of the completed shape of 0).

On the other hand, the outer peripheral forming member 28 has its tip 2
8 d is formed in an arc shape having a radius slightly larger than the radius of the glass material 40, and the width W thereof is slightly smaller than the outer diameter of the glass material 40. The outer peripheral forming member 28 is supported by a supporting device 30 so as to be able to move inward and outward of the body mold 14, just like in the first embodiment.

The operation of positioning the glass material 40 by the optical device molding apparatus thus configured will be described.

First, the fixed positioning member 50 is moved to the above-described positioning operation position by a driving device (not shown). Next, the glass material 40 sucked by the suction finger (not shown) from the opening hole 14 d of the body mold 14 is placed on the lower mold member 18. Thereafter, the tip portion 28 of the outer peripheral forming member 28
d advances and comes into contact with the side surface of the glass material 40, and the compression force of the compression spring 32 acts on the glass material 40. Then, the glass material 40 comes into contact with the positioning surface 50a of the fixed positioning member 50 by this compressive force, and the glass material 40
Is positioned. Thereafter, the upper mold member 16 is lowered, and the molding surface 16b is brought into contact with the upper surface of the glass material 40 so that the glass material 40 no longer moves. Then, the fixed positioning member 50 and the outer peripheral molding member 28 are retracted to predetermined positions. Is done. Then, a pressing operation of the glass material 40 is performed.

Specifically, an experiment was conducted under the following molding conditions.

(Conditions) Upper mold member molding surface shape: convex sphere R30 mm (R2) Lower mold member molding surface shape: convex sphere R30 mm (R1) Glass material shape: upper concave sphere R35 mm (R2 ') Lower concave sphere R35 mm (R1) ') Outer diameter φ14mm (φd) Center thickness 2mm (t0) Fixed positioning member: positioning surface-flat surface, thickness 1mm (t
1) Outer peripheral molding member: Tip shape R 7.2 mm (R3) Width 12 mm (W) Thickness 1 mm (t2) Compression spring: Spring constant 0.05 kg / mm (3 types) 0.1 kg / mm 0.2 kg / mm Above Under such conditions, the spring constant is 0.05 to 0.2 kg / m.
A continuous positioning experiment was performed 200 times as m. As a result, the occurrence of drop failure, cracking and chipping of the glass material 40 during positioning was zero. Further, in all the press-formed products, there was no occurrence of misalignment or unformed portion as the outer diameter accuracy that would cause poor centering, and good center press-forming could be performed.

As described above, according to this embodiment,
The glass material can be accurately positioned on the lower mold member without applying excessive force to the glass material. (Third Embodiment) FIGS. 15 to 17 are views showing the structure of an optical element molding apparatus according to a third embodiment.

In the molding apparatus according to the third embodiment, the body dies of the molding apparatuses shown in the first embodiment and the second embodiment are enlarged, and a plurality of upper and lower mold members are added to the body dies. Are arranged to efficiently form a plurality of lenses.
Others are the same as the first embodiment and the second embodiment.

In this embodiment, a plurality of outer peripheral forming members 28 are simultaneously supported by one supporting device main body 44. In this manner, the support device main body 44 and the driving device 34 are provided on each of the outer peripheral forming members 28.
Thus, the cost of the molding apparatus can be reduced as compared with the case of providing. However, in such a configuration, the plurality of outer peripheral forming members 28 do not always come into contact with the plurality of lower mold members at the same time. The above-described compression spring 32 also plays a role of absorbing such a variation in the contact positions of the plurality of outer peripheral forming members 28 with the lower mold member 18. (Fourth Embodiment) FIG. 18 is a diagram showing a configuration of an optical element molding apparatus 50 according to a fourth embodiment. FIG.
Shows a state where the upper die member is completely lowered and the pressing operation is completed.

In FIG. 18, a molding die 52 constituting a main part of the molding device 50 is provided on a molding device main body 51.
Is placed. The outer shell portion of the molding die 52 is
It consists of. The body mold 54 is formed in a substantially square prism shape in a top view, and through holes 54a and 54b are formed on the center axis of the body mold 54 so as to penetrate the body mold 54 up and down. Of these through holes, the upper through hole 5
A cylindrical upper mold member 56 is slidably inserted in the upper part 4a along the vertical direction in a fitted state.
At the upper end of the upper die member 56, a disk-shaped flange portion 56a is provided.
Is formed, and the lower surface of the flange portion 56a contacts the upper surface 54c of the body mold 54 from above, thereby preventing the upper mold 56 from moving further downward. A downward press stroke of the member 56 is defined. On the lower surface of the upper mold member 56, a molding surface 56b for pressing the glass material 40 and transferring a desired shape to the surface to form an optical function surface is formed.

On the other hand, a lower mold member 58 formed in a columnar shape like the upper mold member 56 is inserted into the lower through hole 54b in a fitted state. Lower surface 58a of lower mold member 58
Is in contact with the upper surface of a supporting substrate 60 on which the body mold 54 is placed, and the downward pressing pressure applied to the lower molding member 58 from the upper molding member 56 via the glass material 40 by the supporting substrate 60. It is configured to receive. Lower mold member 5
A molding surface 58 b for transferring a desired shape to the lower surface of the glass material 40 to form an optical function surface is formed on the upper end surface of the glass material 40. Therefore, on the upper surface of the glass material 40, the optical function surface 40a on which the surface shape of the molding surface 56b of the upper mold member 56 is transferred is formed, and on the lower surface, the surface shape of the molding surface 58b of the lower mold member 58 is formed. Is transferred to the optical function surface 40b.

Further, the molded lens (glass material 4)
As described above, the thickness of 0) is defined by the lower surface of the flange portion 56a of the upper die member 56 abutting on the upper surface 54c of the body die 54, and the thickness of the lens (40) does not change every time processing is performed. It has been done.

On the other hand, in the body mold 54, the body mold 54, the upper mold member 56, and the lower mold member 58 are located at the four corners.
And a heater 66 for heating the glass material 40 via the body mold 54, the upper mold member 56, and the lower mold member 58.

An opening hole 54d is formed on the side surface of the body mold 54.
Is formed, the glass material 40 is supplied into the molding die 52 through the opening hole 54d, and the lens (40) whose molding has been completed is taken out from the interior of the molding die 52. In addition, an opening hole 54e is formed in a side surface of the body mold 54.
Are formed, the cross-sectional shape of which is circular, and the inner surface is finished to a smooth surface. As will be described later in detail, an outer peripheral forming member 68 is slidably inserted into the opening hole 54e with a slight gap.

As shown in FIG. 18 and FIG. 19, which is a cross-sectional view taken along the line AA in FIG. 18, the outer peripheral forming member 68 has a cylindrical main body 68a slidably inserted into the opening hole 54e. , Formed near the tip of the main body 68a,
Positioning surface 68 abutting on outer surface 58c of lower mold member 58
b and an outer peripheral forming portion 68c protruding on the forming surface 58b along a substantially horizontal direction. The distal end portion 68d of the outer peripheral forming portion 68c is formed in an arc shape having a curvature similar to the outer peripheral shape of the completed optical element, that is, the lens (40), as shown in FIG.

Here, the outer peripheral forming member 68 and the device for driving the outer peripheral forming member 68, which are characteristic parts of the present embodiment, will be briefly described.
Compression spring 7 for supporting hand 84 for supporting
2 and via a holding jig 82 behind it. Accordingly, the outer peripheral forming member 68 is urged by the compression spring 82 in a direction toward the central axis of the upper and lower mold members 56 and 58. In parallel with the support hand 84, the rod shaft 85
The driving device 74 of the outer peripheral forming member 68 is connected via the. The rod shaft 85 is moved by an arrow B
The outer peripheral forming member 68 is inserted into the body mold 54 via the support hand 84 and the holding jig 82 by the movement of the rod shaft 85 in the direction of the arrow B. It is driven in a direction to be pulled out and a direction to be pulled out.

The structure of the driving device 74 will be described in further detail. The driving device 74 is a cylinder driving mechanism including a rod shaft 85, a cylinder rod 86, a cylinder outer cylinder 87, and a gas supply / exhaust introduction port 87c. Gas supply / exhaust inlet 87
When the gas (for example, N ₂ ) is supplied from the cylinder c, the front end face 86 a of the cylinder rod 86 is
7 comes into contact with the front abutting surface 87 a of the outer peripheral forming member 6 via the rod shaft 85, the support hand 84, and the holding jig 82.
8 is pulled out with respect to the trunk mold 54. That is, it is driven to the retreat end position. Conversely, the gas supply / exhaust inlet 87c
The gas is exhausted (evacuated) from the cylinder rod 86 so that the rear end face 86b of the cylinder rod 86 is
7 abuts against the rear butting surface 87b of the outer peripheral forming member 68.
Is inserted into the trunk mold 54. That is, it is driven to the forward end position. Further, the support hand 84 is urged in the retreating direction of the outer peripheral forming member 68 via the rod shaft 85 by the compression spring 88 between the counterbore surface 86c at the rear of the cylinder rod 86 and the cylinder rear abutting surface 87b. ing.

Next, the molding apparatus 50 configured as described above is used.
The procedure for molding the lens (40) will be described with reference to FIGS.

First, as shown in FIG. 20, the upper mold member 56 is slid upward with respect to the body mold 54 by a driving device (not shown), and is released from the lower mold member 58. In this state, the glass material 40 heated to a predetermined high temperature by an automatic hand or the like through the opening hole 54d of the body mold 54.
Is supplied onto the molding surface 58b of the lower mold member 58. When forming the convex lens, the glass material 40 supplied at this time is formed into a spherical shape as shown in the figure or a shape close to the completed shape of the convex lens. Further, the body mold 54, the upper mold member 56, and the lower mold member 58
Are heated to a temperature corresponding to predetermined molding conditions.
When the glass material 40 is supplied into the body mold 54, the driving device 74 (see FIG. 21) is used to form the outer peripheral forming member 6.
8 is retracted to the outside of the barrel mold 54 so as not to prevent the glass material 40 from being inserted into the barrel mold 54.

After the glass material 40 is supplied onto the molding surface 58b of the lower mold member 58, the outer peripheral molding member 68 is moved by the driving device 74 in the direction of entering the body mold 54. At this time, the driving device 74 adjusts the position of the supporting device 70 (from the holding jig 82 and the supporting hand 84) slightly more than the position where the positioning surface 68b of the outer peripheral forming member 68 contacts the outer surface 58c of the lower die member 58. Is moved in the direction approaching the lower mold member 58 so that the positioning surface 68b of the outer peripheral forming member 68 elastically abuts on the outer surface 58c of the lower mold member 58 by the spring force of the compression spring 72. As a result, the outer peripheral forming member 68 is set at the predetermined operation position.

In this state, as shown in FIG. 21, the tip portion 68d of the outer peripheral forming portion 68c is located at a position in contact with the circumference having a radius R1 about the center axis of the lower die member 58. In this embodiment, the value of the radius R1 is
Assuming that the outer diameter of the completed lens is D0 (see FIG. 25),
It is set so that 0 <D0 / 2-R1 = x <2 mm.

Thereafter, the upper mold member 56 is moved in a downward direction by a driving device (not shown) to bring the molding surface 56b of the upper mold member 56 into contact with the upper surface of the glass material 40, and press pressure is applied to the glass material 40. Let it. When the press pressure is applied and the upper mold member 56 gradually moves downward, the glass material 40
Is substantially uniformly spread in the outer peripheral direction and deformed, and at a certain point during the pressing operation, the outer peripheral portion of the glass material 40 comes into contact with the tip portion 68d of the outer peripheral forming portion 68c.

When the upper mold member 56 is further pushed down, the outer peripheral forming member 68 is pressed against the urging force of the compression spring 72 by the deforming force of the glass material 40 in the outer peripheral direction.
4 so as to be pushed out. At this time, when the outer peripheral forming member 68 is pushed out of the body mold 54, the compression spring 72 is further compressed and the urging force is increased with an increase in the amount of the extruded member.
In a state where the deformation force of the outer peripheral molding member 68 is
Is pushed by the glass material 40 and moves. Then, finally, the state is as shown in FIG. At this time, with the deformation force of the glass material 40 and the urging force of the compression spring 72 being balanced, the outer peripheral forming portion 68c bites into the side surface of the glass material 40 by an amount indicated by δ in the drawing. By making the outer peripheral forming member 68 bite into the glass material 40 in this manner, the glass material 40 is reliably separated from the upper die member 56 in the subsequent release step, and the lower die member 58
You can leave it on.

In the case where the outer peripheral forming portion 68c is cut into the side surface of the glass material 40 for forming, if the biting amount δ increases, the coefficient of thermal expansion of the glass is larger than the coefficient of thermal expansion of the mold member. In addition, in the outer peripheral biting, cracks may occur in the lens (40) during cooling because the deformation spread of the molded product due to the variation of the blank amount or the like is shifted and the outer peripheral biting portion becomes thinner. is there. Therefore, it is necessary to secure the minimum amount of bite that can prevent the upper mold from adhering.
Cracks may occur in the cooling lens (40). Further, as described later, the outer peripheral forming member 68 is connected to the lens (4
When the lens (40) is separated from the outer peripheral portion, the release resistance becomes excessive, and cracks and chips may occur in the lens (40). Therefore, it is necessary to prevent the amount of penetration δ of the outer peripheral forming member 28 into the lens (40) from becoming excessive.

As the method, in this embodiment,
As described above, the outer peripheral forming member 68 is urged inward by the compression spring 72, and the urging force and the deformation force of the glass material 40 are balanced to adjust the biting amount δ. That is, the optimal bite amount δ into the glass material 40
Thus, the initial spring force of the compression spring 72 and the spring constant are set so as to obtain.

For example, an optical glass SK12 (manufactured by OHARA CORPORATION) is used as the glass material 40, and the outer diameter φ15.
When the double-sided convex lens of No. 6 is molded, and when the outer peripheral bite molding is performed under the following conditions (see also FIG. 24 at the same time),
It has been confirmed that the bite amount δ does not become excessive.

(Conditions) Shape of tip of outer peripheral molded member: width 14 mm, vertical thickness 0.6
mm Tip R7.3mm (from the center of the lower mold member) Arc shape Lens (molded product) shape: outer diameter φ15.6mm, wall thickness 4.
5mm Upper sphere R16.1mm, Lower sphere R16.9mm Initial elastic force of compression spring: 0.3kgf Displacement of outer peripheral forming member Δx = 0.3mm Spring constant k = 0.1kgf / mm Elastic force generated during deformation 0.33kgf Mold member molding temperature: 620 ° C Lower mold member molding temperature: 640 ° C Viscosity of glass: 10 ⁹ to 10 ¹⁰ P (poise) By the way, when bite molding is performed under the above molding conditions, the radius of the completed molded product Is r, the variation of r is r
= 7.25 to 8.0 mm, variation of δ is δ = 0.10
０．３0.32 mm, and the variation of the biting amount ratio (δ / r) was δ / r = 1.4 to 4.0%.

[0098] Of the above molding conditions, the spring constant k
When only k = 0.2 kgf / mm, the variation of r is r = 7.25 to 8.0 mm, and the variation of δ is δ
= 0.4 to 0.6 mm, and the variation of δ / r is δ / r =
5.5 to 7.5%, cracks, cracks, and the like occurred at the boundary between the lens portion and the cutout outer peripheral member.

Further, among the above molding conditions, the spring constant k
When only k = 0.05 kgf / mm, the variation of r is r = 7.25 to 8.0 mm, the variation of δ is δ = 0.02 to 0.08 mm, and the variation of δ / r is δ /
r = 0.3 to 1.0%, and when the upper mold is released, the adhesive force between the upper mold and the lens loses the force of pressing the outer peripheral molding member toward the lower mold, causing poor adhesion of the upper mold. I have.

Next, as shown in FIG.
When the pressing by the above is completed, the lens (40) is cooled. When the temperature of the lens (40) becomes equal to or lower than the glass transition temperature, the outer peripheral forming member 68 is moved to the lens (4).
The upper mold member 16 is lifted up while being bitten into 0), and is reliably separated from the lens (40) to open the mold. At this time, the lower mold member 5 is attached to the outer periphery of the lens (40).
The biasing force of the compression spring 72, which has been acting via the outer peripheral forming member 68 in the direction of the center axis of
0), the lens (40)
However, a displacement occurs in a direction opposite to the outer peripheral forming member 68 and is left on the lower mold member 58. When this gap occurs,
When the lens (40) is taken out of the body mold 54 by the suction finger 89, the lens (40) may not be able to be taken out by suction due to a positional shift with the suction finger 89, or the lens (40) may be scratched or chipped by the suction finger 89. It will cause damage. Therefore, before the upper mold member 56 is released, it is necessary to release the urging force of the outer peripheral forming member 68 in the direction of the center axis of the lens (40).

The method will be described below. First, when the cooling of the lens is completed, the outer peripheral forming member 68 has penetrated the lens (40), and as shown in FIG.
Since the gas is exhausted (evacuated) from the gas supply / exhaust introduction port 87c of the driving device 74, the rear end surface 86b of the cylinder rod 86 comes into contact with the rear abutting surface 87b of the cylinder outer cylinder 87, and the rod shaft 85, support hand 8
4, the holding jig 82 is driven to the forward end position in the direction (center of the lower die) inserted into the trunk die 54.
Further, the outer peripheral forming member 68 is in the bite state described above,
The positioning surface 68b of the outer peripheral forming member 68 is shifted from the outer surface 58c of the lower mold member 58 in the direction opposite to the central axis (outside the body mold) by ΔX
(Distance radius R2-R from the center axis of the lower mold member 58 at the tip end 28d of the outer peripheral molding member 68 in the final biting state.
1) It has moved to the position where it has receded by minutes. At this time, the total length of the compression spring 72 between the concave bottom surface 68e of the outer peripheral forming member 68 and the concave bottom surface 82d of the holding jig 82 is the shortest, and the compression spring of the outer peripheral forming member 68 in the central axis direction of the lower mold member 58 is reduced. The biasing force of 72 is maximum.

Therefore, immediately before the upper mold member 56 is released from the mold, the gas exhaust which is the driving source of the driving device 74 is turned off (that is, the vacuum leak in the cylinder outer cylinder 87 is caused), and the front end face 86 a of the cylinder rod 86 is Release the applied pressure, and counterbore surface 86c behind cylinder rod 86
And compression spring 8 between cylinder rear butting surface 87b
The support hand 84 is moved in the retreating direction of the outer peripheral forming member 68 via the rod 85 by applying the elastic biasing force of 8. As shown in FIG. 23, the moving position of the outer peripheral forming member 68
Of the shaft member 68f and the locking portion 82a of the holding jig 82 are latched by the spring member 72 (only being held in tension), that is, the elasticity of the outer peripheral forming member 68 with respect to the lens (40). From the state where the urging force becomes zero to just before the hook 84a of the support hand 84 hooks with the hook 82c of the holding jig 82 (begins moving the outer peripheral forming member 68 in the retreating direction). The support hand 84 is at a position where the support hand 84 is retracted.

With the above method, the outer peripheral forming member 68 is cut into the lens (40) and the lens (4
If the upper mold member 56 is lifted in a state where the urging force of the outer peripheral forming member 68 in the central axis direction of (0) is released, the lens (4
Since 0) is pressed by the outer peripheral forming member 68, it is surely separated from the upper die member 56, and is left as it is without being displaced on the lower die member 58,
Demolding is performed.

Then, as shown in FIG. 25, an automatic hand or the like (suction hand) is used to
4d, the suction surface 89a of the suction hand 89 is set to a position where it can be sucked with the lens (40) on the lower mold member 58. In this state, the outer peripheral forming member 68 is driven by the driving device 74 (the gas supply / exhaust introduction port 87 c of the cylinder outer cylinder 87).
Gas is supplied from the cylinder rod 8
6 is driven in a direction away from the lens (40) by the front abutting surface 87a of the cylinder outer cylinder 87), and the outer peripheral forming member 68 is separated from the lens. Then, the lens (40) is sucked by the suction surface 89a of the suction hand 89 without causing damage such as scratches and chips, and is quickly taken out from the opening hole 54d in the body mold 54.

FIG. 26 shows the value of the bite amount δ when bite forming is performed under various forming conditions different from the above-mentioned conditions. However, the tip shape of the outer peripheral forming member 68 and the curvature of the upper and lower surfaces of the lens (40) are the same as those described above. According to FIG. 26, when the spring constant k of the compression spring 72 is k = 0.05 kg / mm, the frequency of occurrence of an uncut portion on the outer peripheral portion of the lens (40) is as high as about 50%, and The binding force may not be secured stably. When k = 0.2 kg / mm, the lens (4
0), the bite amount δ at the outer peripheral portion is large, and the lens (4)
There is a problem in the point of interference with the effective diameter of the optical function part in 0).
Further, when the outer peripheral molding member 68 and the lens (40) are released from the mold, the release resistance is increased, and it is expected that the lens (40) may be cracked or chipped. Therefore, under the molding conditions of this embodiment, the spring constant k of the compression spring 72 is 0.1 k
g / mm seems to be optimal.

In the above embodiment, the effect of the case where the outer peripheral forming member 68 is disposed on only one side of the lower die member 58 has been described. , 58 can also be applied to the multi-cavity molding in which the arrangement of the outer peripheral molding member of the above embodiment is applied.

Next, the structure of the outer peripheral forming member 68 and the supporting device 70 for supporting the outer peripheral forming member 68 will be described in more detail.

According to the method described above, the lens (40)
When press molding, it is necessary to heat the body mold 54 and the upper and lower mold members 56 and 58 to a considerably high temperature, and to cool from that temperature to a low temperature of about room temperature. Therefore, in this embodiment, the body mold 54 and the outer peripheral forming member 68 are made of a material having substantially the same coefficient of thermal expansion, and the sliding of the outer peripheral forming member 68 relative to the body mold 54 in and out is facilitated. A predetermined clearance is provided between the outer peripheral surface of the outer peripheral member body 68a and the inner peripheral surface of the opening 54e.

Here, when the outer peripheral forming member 68 is slid inward and outward with respect to the body mold 54, the driving force must be applied on the central axis of the outer peripheral forming member main body 68a or the outer peripheral forming member 68a must be driven. The member 68 may be tilted in the opening hole 54e to cause staking with the body mold 54, thereby causing a flaw or the like on the body mold 54 and the outer peripheral forming member 68, which may result in the inability of continuous molding.

For this reason, in this embodiment, the structure of the supporting device 70 for supporting the outer peripheral forming member 68 is devised so that the driving force from the driving device 74 is always applied to the outer peripheral forming member main body 68.
Work along the central axis of Hereinafter, the configuration of the support device 70 will be described.

Here, since a part of the outer peripheral forming member 68 also functions as a part of the support device 70, the structure of the outer peripheral forming member 68 will be described again with reference to FIG.

As described above, the outer peripheral forming member 68 is formed with the outer peripheral forming portion 68b formed in an arc shape and the positioning surface 68c which comes into contact with the outer side surface 58c of the lower mold member 58 at the distal end portion. On the other hand, behind the outer peripheral forming member 68, a cylindrical concave portion 68d is formed coaxially with the central axis 68g of the cylindrical outer peripheral forming member main body 68a. The compression spring 72 described above is inserted into the cylindrical recess 68d. Then, one end of the compression spring 72 presses the bottom surface 68e of the concave portion 68d, so that the outer peripheral forming member 68 is
The lower mold member 58 is urged toward the central axis. Here, the central axis of the cylindrical concave portion 68d is the outer peripheral molded member main body 68a.
And the bottom surface 68e of the concave portion 68d is orthogonal to the central axis 68g, so that the urging force of the compression spring 72 is applied to the center of the outer peripheral forming member 68 relative to the outer peripheral forming member 68. It will work along the axis 68g.

A shaft member 68f is attached to both sides of the rear end of the outer peripheral forming member 68 with its central axis orthogonal to the sliding central axis 68g. on the other hand,
As shown in FIGS. 28 and 29, the support device 30 includes a holding member 82 that supports the shaft member 68f, and a support hand 84 that supports the holding member 82.
The support hand 84 is connected to the rod shaft 75 of the driving device 74 described above.

The holding member 82 is formed in a rectangular shape when viewed from the front, and a hook portion 82a for hooking the shaft member 68f of the outer peripheral forming member 68 is formed in front of the holding member 82. A cylindrical concave portion 82d is formed at the center of the holding member 82 coaxially with the central axis 68g of the outer peripheral forming member 68. Then, one end of the compression spring 72 is
By pressing the 2d bottom surface 82e, the holding member 82
Are urged in the direction opposite to the central axis of the lower mold member 58. That is, the holding member 82 is held by the shaft member 68f of the outer peripheral forming member 68 and the latching portion 82a being held together by the spring force of the compression spring 72, and is prevented from dropping from the outer peripheral forming member 68. Have been.

The outer peripheral forming member 6 is provided above and below the holding member 82.
A substantially cylindrical projection 82c having a central axis perpendicular to the vertical direction is formed on the sliding central axis 68g of No.8. And
The protrusion 82 c is provided with a predetermined clearance from the hook 84 a of the support hand 84, and the support hand 84
Is moved in the direction opposite to the central axis of the lower mold member 58 by the driving device 74 and comes into contact therewith. At this time, the outer peripheral forming member 68
The shaft member 68f of the outer peripheral forming member 68 and the engaging portion 82a
The lower hand member 58 is moved in a direction opposite to the central axis of the lower mold member 58 by the support hand 84 via the holding state by a spring.

In such a configuration, since the holding member 82 is in line contact with the hook 84a of the support hand 84 at the projection 82c, the contact line 8
It is possible to swing in the horizontal direction with 2b as a fulcrum. Since the contact line 82b is perpendicular to the sliding center axis 68b in the vertical direction, the outer peripheral forming member 68 can swing left and right about the sliding center axis 68g.
Since a predetermined clearance is provided between the outer shape of the holding member 82 and the inner shape of the support hand 84, the holding member 82 can move up, down, left, and right with respect to the support hand 84.

Further, the outer peripheral forming member 68 includes a holding member 82.
Is supported via the shaft member 68f, so that the outer peripheral forming member 68 can swing vertically with respect to the holding member 82, and can also move vertically and horizontally. It is. Therefore, the outer peripheral forming member 68
Is slidable up, down, left and right with respect to the support hand 84,
And it will be supported so that it can swing up, down, left and right,
Further, since the biasing force of the compression spring acts along the sliding central axis 68g of the outer peripheral forming member 68, the driving hand 74 moves the supporting hand 84 vertically and horizontally with respect to the sliding central axis 68g. Even if it is shifted (due to thermal deformation, displacement of the processing jig, or the like), a driving force always acts on the outer peripheral forming member 68 along the sliding center axis 68g. Therefore, the outer peripheral forming member 68 can smoothly enter and exit along the opening hole 54e of the body mold 54, and the occurrence of galling defects, scratches, and the like is prevented. FIG. 30 shows the positioning surface 68c of the outer peripheral forming member 68.
Comes into contact with the outer side surface 58c of the lower die member 58, and the compression spring 72 is compressed.
FIG. 6 is a diagram showing a state where the member is freely supported by only the member.

As described above, according to this embodiment,
By molding the lens in a state where the outer peripheral molding member is cut into the outer peripheral portion of the glass material, it is possible to reliably prevent the upper die from attaching to the upper die member when the mold is released.

Further, since the outer peripheral forming member is supported by the supporting device so as to be slidable in the vertical and horizontal directions and swingable in the vertical and horizontal directions, the outer peripheral forming member is always inserted into and out of the body mold. Since the outer peripheral forming member can slide back and forth along the center axis of sliding with the body mold, it is possible to smoothly enter and exit without generating galling and the like.

Next, a description will be given of a modified example of the shape of the distal end portion of the outer peripheral molding member and the shape characteristics of a molded article (optical element) formed by the outer peripheral molding member of this modified example.

FIG. 31 is a view showing a state in which the lens 41 is formed by the outer peripheral forming member 68 of the modified example.
In FIG. 31, the distal end portion 68h of the outer peripheral forming member 68 is formed in a shape inclined by θ with respect to the vertical direction as shown. When the lens 41 is molded using such an outer peripheral molding member 68, a concave portion 41a as shown in FIG. 32 is formed in the lens 41. If such a concave portion 41a is formed in the lens 41, it is possible to easily determine the front and back of a lens in which the curvature radius of the front surface and the curvature radius of the back surface of the lens are slightly different. . When assembling the molded lens into a lens barrel or the like, it is extremely important to ensure that the front and back of the lens are correct with respect to the film surface in order to ensure the optical performance of the lens. By forming the concave portion 41a serving as a mark for discriminating the front and back as described above, this can be performed extremely easily. In addition, the concave portion 41a can also be useful for determining which surface is the centering surface at the time of lens centering processing in a process before assembling the lens.

The direction of the inclined surface of the concave portion 41a can be automatically determined by a sensor, image recognition by an ITV camera, or the like. In this case, θ is from 5 °
It is desirable that the angle be in the range of 60 °. Then, the lens 41 whose front and back are determined in this manner is gripped by the lens holder 47 and incorporated into the lens barrel 45 as shown in FIG. 33, for example.

FIGS. 34 and 35 show another example of the shape of the concave portion 41a. As shown in FIG. 34, an R-shaped engraved portion 41b is provided at the center of the concave portion 41a. 3
As shown in FIG. 5, a triangular engraved portion 41c may be provided. As described above, by providing the R-shaped or triangular engraved portions, it is possible to visually and easily determine the front and back of the lens 41.

Next, FIGS. 36 to 39 are views showing another method of using the concave portion 41a formed in the lens 41. FIG. As shown in FIG. 36 and FIG.
Not only from the direction but also from the three directions at equal intervals on the circumference, for example, the lens 41 is cut into the lens 41 to form the concave portion 41a.
Are formed at three locations on the outer periphery. The inclined surfaces of these concave portions 41a are brought into contact with a body-attached portion 43a provided on the lens barrel 43 as shown at 39 in FIG. 38 to position the lens 41 with respect to the lens barrel 43. Then, the lens 41 is fixed to the lens barrel 43 by bending down the swaging portion 43c of the lens barrel 43 inward of the lens. This makes it possible to provide the concave portion 41a, which is necessarily formed to prevent the lens 41 from adhering to the upper mold, with a lens positioning function.
This eliminates the need for processing such as providing a positioning portion in the first device, and is efficient. (Fifth Embodiment) FIGS. 40 to 42 are views showing the structure of an optical element molding apparatus according to a fifth embodiment.

In the molding apparatus of the fifth embodiment, the body of the molding apparatus shown in the fourth embodiment is enlarged, and a plurality of upper and lower mold members are arranged on the body. Is efficiently molded. Others are the same as the fourth embodiment.

In this embodiment, a plurality of outer peripheral forming members 68 are simultaneously supported by one supporting hand 84. This makes it possible to reduce the cost of the molding device as compared with the case where the support hand 84 and the driving device 74 are provided for each of the outer peripheral molding members 68. However, in such a configuration, the plurality of outer peripheral forming members 68 do not always come into contact with the plurality of lower mold members at the same time. The above-described compression spring 72 also plays a role of absorbing such a variation in the contact positions of the plurality of outer peripheral forming members 68 with the lower mold member 58.

The present invention can be applied to a modification or a modification of the above embodiment without departing from the gist of the invention.

[0128]

As described above, according to the present invention, the outer peripheral molding portion of the outer peripheral molding member is protruded from the molding surface by a predetermined amount, and the glass material is press-molded in that state, thereby forming the outer peripheral molding member on the molding surface. The outer peripheral molding portion cuts into the outer peripheral portion of the glass material that has been pushed out. When the upper mold member is pulled up in a state where the outer peripheral molding portion has cut into the outer peripheral portion of the glass material, the glass material is held by the outer peripheral molding portion and adheres to the lower mold member. , And only the upper mold member is separated from the glass material.

In addition, the plurality of outer peripheral forming members are elastically held independently of each other with respect to the holding member. This elastic force corrects the positional deviation of the positioning surfaces of the plurality of outer peripheral forming members, and the plurality of outer peripheral forming members are corrected. The positioning surface of the outer peripheral molding member simultaneously abuts the lower mold member, thereby preventing malfunction of the outer peripheral molding member.

Further, the portion of the optical element which the outer peripheral molding bites into serves as an identification mark for determining the front and back of the optical element, so that the front and back of the optical element can be easily determined.

[Brief description of the drawings]

FIG. 1 is a diagram showing a structure of an optical element molding apparatus according to a first embodiment.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a view showing a procedure of molding a lens by the optical element molding apparatus according to the first embodiment.

FIG. 4 is a view showing a procedure of molding a lens by the optical element molding apparatus according to the first embodiment.

FIG. 5 is a diagram showing a procedure for molding a lens by the optical element molding apparatus according to the first embodiment.

FIG. 6 is a view showing a procedure for molding a lens by the optical element molding apparatus according to the first embodiment.

FIG. 7 is a diagram showing a procedure of molding a lens by the optical element molding apparatus according to the first embodiment.

FIG. 8 is a diagram showing the relationship between molding conditions and the amount of bite.

FIG. 9 is a perspective view showing the structure of the outer peripheral forming member.

FIG. 10 is a view showing a structure of a supporting device for an outer peripheral forming member.

FIG. 11 is a view showing a structure of a support device for an outer peripheral forming member.

FIG. 12 is a view showing a structure of a supporting device for an outer peripheral forming member.

FIG. 13 is a view showing a structure of an optical element molding apparatus according to a second embodiment.

FIG. 14 is a view showing the structure of an optical element molding apparatus according to a second embodiment.

FIG. 15 is a view showing the structure of an optical element molding apparatus according to a third embodiment.

FIG. 16 is a view showing the structure of an optical element molding apparatus according to a third embodiment.

FIG. 17 is a view showing the structure of an optical element molding apparatus according to a third embodiment.

FIG. 18 is a view showing the structure of an optical element molding apparatus according to a fourth embodiment.

19 is a sectional view taken along line AA of FIG.

FIG. 20 shows an optical element molding apparatus according to a fourth embodiment.
FIG. 3 is a diagram showing a procedure for forming a lens.

FIG. 21 shows an optical element molding apparatus according to a fourth embodiment.
FIG. 3 is a diagram showing a procedure for forming a lens.

FIG. 22 shows an optical element molding apparatus according to a fourth embodiment.
FIG. 3 is a diagram showing a procedure for forming a lens.

FIG. 23 shows an optical element molding apparatus according to a fourth embodiment.
FIG. 3 is a diagram showing a procedure for forming a lens.

FIG. 24 shows an optical element molding apparatus according to a fourth embodiment.
FIG. 3 is a diagram showing a procedure for forming a lens.

FIG. 25 shows an optical element molding apparatus according to a fourth embodiment.
FIG. 3 is a diagram showing a procedure for forming a lens.

FIG. 26 is a diagram showing a relationship between molding conditions and a bite amount.

FIG. 27 is a perspective view showing the structure of the outer peripheral forming member.

FIG. 28 is a view showing the structure of a support device for an outer peripheral forming member.

FIG. 29 is a view showing the structure of a supporting device for an outer peripheral forming member.

FIG. 30 is a view showing a structure of a supporting device for an outer peripheral forming member.

FIG. 31 is a view showing a modified example of the outer peripheral forming member.

FIG. 32 is a view showing the shape of a molded lens.

FIG. 33 is a diagram showing a state in which a lens is incorporated in a lens barrel.

FIG. 34 is a diagram showing the shape of a molded lens.

FIG. 35 is a diagram showing the shape of a molded lens.

FIG. 36 is a view showing an arrangement state of an outer peripheral forming member when a lens of another example is formed.

FIG. 37 is a view showing the shape of a lens in another example.

FIG. 38 is a diagram showing a state where a lens is incorporated in a lens barrel.

FIG. 39 is a diagram showing a state where the lens is incorporated in a lens barrel.

FIG. 40 is a view showing the structure of an optical element molding apparatus according to a fifth embodiment.

FIG. 41 is a view showing the structure of an optical element molding apparatus according to a fifth embodiment.

FIG. 42 is a view showing the structure of an optical element molding apparatus according to a fifth embodiment.

FIG. 43 is a diagram showing a conventional example.

FIG. 44 is a diagram showing a conventional example.

FIG. 45 is a diagram showing a conventional example.

[Explanation of symbols]

 10,50 Molding device 12,52 Molding mold 14,54 Trunk mold 16,56 Upper mold member 18,58 Lower mold member 28,68 Outer peripheral molding member 30,70 Supporting device 40 Glass material

Continuation of front page (72) Inventor Nobuyuki Nakagawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (56) References JP-A-60-171230 (JP, A) JP-A-60-171236 ( JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C03B 11/00 C03B 11/08

Claims (10)

(57) [Claims] 1. A method of molding an optical element such as a lens, comprising inserting a glass material between an upper mold and a lower mold having a molding transfer surface for molding an optical functional surface of the optical element. Then, at least, the glass material is heated to a molding temperature, the glass material heated by the upper mold and the lower mold is pressurized, and the surface shape of the molding transfer surface of the upper mold and the lower mold is transferred to the optical element. In the method for molding an optical element, an engaging means is provided for engaging a part of the outer peripheral portion of the optical element to be formed, and the engaging means is inserted between the upper mold and the lower mold. The engaging member of the engaging means is engaged with the molded optical element in accordance with the completion of the molding of the glass material by the closing operation of the upper mold and the lower mold in conjunction with the pressing operation of the glass material. And pressurizing the glass material during the pressing operation of the glass material. Molding of an optical element, characterized in that to avoid tying the engaging means and the engaged portion not in the outer peripheral portion of the. 2. A mold opening operation after the closing operation of the upper mold and the lower mold is finished, the molded optical element is left in one mold by the engagement member and released from the other mold. The method for forming an optical element according to claim 1, wherein: 3. A method for molding an optical element such as a lens, wherein a glass material is inserted between an upper mold and a lower mold having a molding transfer surface for molding an optical functional surface of the optical element. Then, at least, the glass material is heated to a molding temperature, the glass material heated by the upper mold and the lower mold is pressurized, and the surface shape of the molding transfer surface of the upper mold and the lower mold is transferred to the optical element. In the method of molding an optical element, forming means for engaging a glass material inserted between the upper mold and the lower mold, prior to the closing operation of the upper mold and the lower mold, or In conjunction with the closing operation, the engaging means is brought into contact with the glass material to hold the glass material at a predetermined position on the upper mold and the lower mold. Optical elements are formed by changing the shape of the material Method of molding an optical element characterized. 4. A glass material is inserted between an upper mold and a lower mold having a molding transfer surface for molding an optical functional surface of an optical element,
At least, the glass material is heated to a molding temperature, the glass material heated by the upper mold and the lower mold is pressed, and the surface shape of the molding transfer surface of the upper mold and the lower mold is transferred to form an optical element. An optical element forming apparatus for forming a mold, comprising: a mold having the upper mold and the lower mold, wherein the molding is performed so as not to restrain an outer peripheral portion of the glass material during a pressing operation of the glass material. A mold, engaging means for engaging a part of the outer peripheral portion of the optical element to be formed, and interlocking the engaging means with a pressing operation of a glass material inserted between the upper mold and the lower mold, A molding device for an optical element, comprising: driving means for driving the engaging means in accordance with the deformation of the glass material by the closing operation of the upper mold and the lower mold. 5. The apparatus according to claim 4, wherein the driving unit is operated by an inert gas. 6. An optical system comprising a plurality of pairs of upper and lower mold members having a molding surface for pressing a glass material which has been softened by being heated and transferring a predetermined shape to the surface of the glass material. In the device molding device, a molding die including the plurality of pairs of mold members, wherein the molding die is configured not to restrain an outer peripheral portion of the glass material during a pressing operation of the glass material; A positioning surface that is provided corresponding to each of the upper and lower mold members, and that abuts a side surface of a lower mold member of the upper and lower mold members, and that the positioning surface abuts a side surface of the lower mold member. A plurality of outer peripheral forming members having an outer peripheral forming portion projecting by a predetermined amount on a part of the molding surface along a substantially horizontal direction in a state, a holding member that collectively holds the plurality of outer peripheral forming members, Hold the holding member on the molding surface Driving means for moving back and forth along the direction normal to the center axis; and elastically supporting the plurality of outer peripheral forming members independently of the holding member, and positioning the outer peripheral forming member to the positioning surface. And a plurality of elastic support means for urging the elastic member in a direction in which it contacts the side surface of the lower mold member. 7. The urging force of the elastic supporting means for urging the positioning surface to abut on the side surface of the lower mold member is such that the glass material is pressed and spread on the molding surface. In the process, the outer peripheral forming portion of the outer peripheral forming member is set to a value such that the outer peripheral forming portion bites into the outer peripheral portion of the glass material by an optimum amount while balancing the viscosity of the glass material. 7. The molding device for an optical element according to 6. 8. In a state where the outer peripheral forming portion bites into the outer peripheral portion of the glass material, the upper mold member of the upper and lower mold members is separated from the molded glass material to thereby remove the glass material. The molding device for an optical element according to claim 7, wherein is formed on the lower mold member. 9. The elastic member according to claim 9, wherein the outer peripheral forming member is supported on the holding member by the elastic supporting means such that parallel and rotational movements are allowed in a vertical plane and a horizontal plane. Item 7. An optical element molding apparatus according to Item 6. 10. The glass material is formed in a shape close to the completed shape of the optical element or in a flat plate shape, and the glass material is so formed that its central axis substantially coincides with the central axis of the molding surface. 7. The optical element molding apparatus according to claim 6, wherein the positioning is performed by an outer peripheral molding member and a fixed positioning member disposed to face the outer peripheral molding member.