JP3023182B2 - Release method of optical element - 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 releasing an optical element such as a glass lens by press molding with a mold.

[0002]

2. Description of the Related Art In recent years, as a method of manufacturing an optical element, press molding has been carried out in which a glass material of a heat-softened optical element is inserted and arranged between a pair of high-precision molding dies, and the optical element is obtained simply by pressing the glass material. Is being done.

Conventionally, as a method of releasing an optical element from a molding die when the optical element is molded by the press molding, there is a method disclosed in, for example, JP-A-62-153127.

In this release method, a release ring is disposed so as to be vertically movable with respect to the upper and lower dies, and an optical element pressed and formed by the upper and lower dies is sandwiched between the upper and lower dies and the upper and lower release rings. Lowered and released from the lower mold, then, for the upper mold that is a fixed mold, by a method of simultaneously lowering the upper and lower release rings and releasing from the upper mold, to the optical element pressed and molded, The mold release can be performed without giving a distortion, a scratch, or the like.

On the other hand, in recent years, with the spread of optical element molding technology and its use, the mold surface of a mold for press-molding a lens surface of a conventional optical element is integrally molded into a single mold ( In the following, there is a growing need for a deformable optical element that cannot be processed.

As such a modified optical element, for example, an illumination lens for uniformly illuminating a wide-angle region is known. This illumination lens is, for example, shown in FIG.
Is required to have a shape as shown in a perspective view. That is, the lens 1 has an inverted conical space (concave portion) in the center of the convex portion of the plano-convex lens, and has a flat portion on the outer periphery thereof, and the cross section thereof is, as shown in FIG. , Two peaks are formed with the points A1 and A2 as vertices. The point A1, the point A2, and the point B are formed in an edge or a small R shape, respectively.

FIG. 19 is a longitudinal sectional view of an optical element molding die for molding an irregularly shaped lens having such a shape. The sectional shape of the molding surface is shown in FIGS.
It is necessary that the lens surface shown in FIG. That is, the points of the molding die corresponding to the points A1, A2, and B of the lens are CA1, CA2, respectively.
And CB. When processing such a mold, the point C
Since a grinding tool does not enter A1, the point CA2, and the vicinity thereof, a molding die capable of molding an odd-shaped optical element could not be actually obtained by integral processing.

Therefore, as shown in FIG. 20, a molding die 2 for molding the above-mentioned deformed optical element is a two-piece molding in which a molding surface 5 is formed by inserting a nesting die 3 into an outer die 4. Must be used.

[0009]

However, the two-body type 2
In order to obtain sufficient transferability when molding an odd-shaped optical element by using the method, the glass material in a flowing state flows into the parting line 6 formed at the fitting portion of the nesting die 3 with the outer die 4. Thus, burrs 8 are formed on the optical element 7 as shown in FIG. Since glass is a brittle material, the nest 3 and the outer mold 4 are formed in a state where burrs 8 are formed on the parting line 6.
Fig. 2
As shown in FIG. 2, the burr 8 was caught on the parting line 6, and the optical element 7 had defects such as chipping and cracks originating from the burr 8.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and when releasing a deformed optical element formed by a two-piece mold, the optical element can be separated without causing defects such as chips and cracks in the optical element. It is an object of the present invention to provide a mold releasing method for a moldable optical element.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method for manufacturing a semiconductor device having a parting line on a molding surface.
After molding the optical element using the body, one of the two bodies is released from the optical element, and then the other of the two bodies is released from the optical element.

[0012]

Embodiment 1 First, before describing a specific embodiment of the present invention, an outline of a method of releasing an optical element of the present invention will be described with reference to FIGS.
It will be described based on. As shown in FIG. 2, one of the upper and lower molding dies 2 and 9 has a molding die 2 and an outer die 4 has a nesting die 3.
The optical element 7 is press-molded using the two-piece mold 2 in which one is formed so as to be movable in the axial direction to form one molding surface. Thereafter, when the two-piece mold 2 is released from the optical element 7, FIG.
As shown in FIGS. 3 and 4, first, either the nested mold 3 or the outer mold 4 of the two-piece mold 2 is released, and then the remaining unmolded outer mold 4 or nested mold 3 is released. Release the mold. When the optical element 7 is pressed and formed by the two-piece mold 2 and the one-piece mold 9 (see FIG. 2), the optical element 7 has a parting line formed at a fitting portion between the nesting mold 3 and the outer mold 4. Fine burrs are formed by the flowing glass that has entered 6. And
At the time of mold release, first, only one of the nested mold 3 and the outer mold 4 of the two-piece mold 2 is driven in a direction to release the optical element 7 (see FIG. 1 or FIG. 3). The nesting mold 3 and the outer mold 4 that have not been moved are driven in the direction of releasing. As a result, the two-piece mold 2 can be moved into the nest 3 and the outer mold 4 without applying a force to burrs generated on the parting line 6.
Are sequentially released from the mold, so that generation of chips, cracks, and the like from the burrs on the optical element 7 is prevented. The release from the one-piece mold 9 is performed by moving the release ring 10 provided to be vertically movable with respect to the one-piece mold 9 in a direction of releasing (downward in FIG. 4). The mold release with
When the two-body type 2 is the upper type, the optical element 7 is the one-type type (lower type).
9, when the two-piece mold 2 is a lower mold, the optical element 7 is
It is performed so that it remains in one of the nesting mold 3 and the outer mold 4 of the two-piece mold 2.

Hereinafter, specific embodiments of the present invention will be described.
5 to 10 show Example 1 of the mold release method of the present invention. The upper mold 11 and the lower mold 12 shown in the figure are made of cemented carbide, and the surface thereof is coated with chrome nitride. I have.
The upper mold 11 and the lower mold 12 are fixed to a mold fixing mount (not shown). The upper mold 11 functions as a fixed mold, and the lower mold 12 functions as a movable mold that can move up and down by a cylinder (not shown) attached to a mold fixed mount.

A release ring 13 made of stainless steel is disposed on the outer periphery of the upper die 11 so as to be vertically movable, and the upper die 11 is released by moving the release ring 13 downward (FIG. 7). reference).

The lower mold 12 includes a nesting mold 14 and an outer mold 15, and the nesting mold 14 is movably fitted in the outer mold 15. A parting line 16 is formed at a fitting portion between the nesting die 14 and the outer die 15, and a clearance of 2 μm to 10 μm is formed in the parting line 16.

The nesting mold 14 is composed of a small diameter part and a large diameter part, and an outer mold 15 is placed on a step 14a which is a boundary between the small diameter part and the large diameter part. A molding surface capable of pressing the 17a into the desired optical element 17 is formed.

The outer die 15 has a flange 18 formed on the outer periphery thereof. In the vicinity of the outer periphery of the outer mold 14, a ring-shaped stopper 1 made of stainless steel having an inner diameter larger than the outer diameter of the outer mold 14 and smaller than the flange 18 is provided.
9 is disposed vertically below the flange 18 so as to be vertically movable, and by locking the flange 18 and the stopper 19, the outer die 14 is held at a predetermined position, and the outer die 14 is vertically moved while being held. It is possible to do.

In the drawing, reference numeral 20 denotes an optical material 17.
a is placed and conveyed between the molding dies 11 and 12, and the pressed optical element 17 is placed on the molding dies 11 and 12.
The conveying member 20 is made of stainless steel, and has an optical material 17a therein.
A step 21 for mounting the optical element 17 is formed.

Next, a method of pressing the optical element 17 with the upper mold 11 and the lower mold 12 and then releasing the upper mold 11 and the lower mold 12 from the optical element 17 will be described.

Optical material 1 heated to a predetermined temperature in a heating furnace
7a is held by the conveying member 20 and conveyed between the upper and lower dies 11, 12, and is driven by a cylinder (not shown) to form the
The rise of the outer mold 15 starts together with the rise of the outer mold 15 (see FIG. 5).

Further, the nesting mold 14 and the outer mold 15 are raised to move the optical material 17a held by the transport member 20 into the nesting mold 1.
4. The top surface of the outer mold 15 is further pushed upward to cooperate with the upper mold 11 to be pressed. At this time, a part of the optical material 17a flows into the parting line 16 due to the glass flow, and minute burrs are formed (see FIG. 6).

After the press forming of the optical element 17 by the upper mold 11 and the lower mold 12 is completed, the lower mold 12 and the release ring 13 are lowered, and the optical element 17 is pressed by the release ring 13 and Release from The stopper 19 is raised to a predetermined position and stopped (see FIG. 7).

Further, the lower mold 12 is lowered, and the outer mold 15 is lowered.
Then, only the outer mold 15 stops descending by contacting the flange 18 with the stopper 19 (see FIG. 8).

Then, the nest 14 is further lowered.
At this time, the optical element 17 is placed on the top surface and the molding surface of the outer mold 15, and the optical element 17 is released from the insert mold 14 (see FIG. 9). When the nesting mold 14 is released, the nesting mold 14 moves in a direction away from the minute burrs formed by the parting line 16, that is, in a direction in which no force acts on the burrs. No cracks, chips, or the like originating from the fine burrs are generated on the optical element 17.

Thereafter, when the insert mold 14 descends and stops at the lowest point, the stopper 19 starts descending, and the outer mold 15 and the optical element 17 descend accordingly. By the lowering of the stopper 19, the optical element 17 held by the outer mold 15 comes into contact with the step 21 of the conveying member 20, and further by the lowering of the stopper 19 and the outer mold 15, the optical element 17 is held by the step 21. The optical element 17 is released from the outer mold 15 (FIG. 10).
reference). After that, the outer mold 15 descends, and the lower end of the outer mold 15 comes into contact with the step 14a of the nesting mold 14, and the descending ends.

As described above, according to the release method of the present embodiment, the release of the optical element 17 from the lower mold 12 which is a two-piece type is performed as follows.
Since the nesting mold 14 and the outer mold 15 are performed in this order, cracking and chipping of the optical element due to minute burrs formed on the parting line 16 during press molding can be prevented. Even when the two-piece mold 2 is arranged as the upper mold, the mold release can be performed similarly while exhibiting the same operation and effect.

[0027]

Embodiment 2 FIGS. 11 to 16 show a second embodiment of the mold release method of the present invention. The lower mold 12 is composed of an insert mold 23 and an outer mold 25, and the insert mold 23 is an outer mold. 15 so as to be freely movable. And, the nesting mold 23 and the outer mold 24 are
Each is connected to a cylinder (not shown), which is a separate drive source, and is configured to be independently movable up and down by driving the cylinder. Other configurations are the same as those in the first embodiment.

Next, a method for press-molding the optical element 17 with the upper mold 11 and the lower mold 12 and then releasing the upper mold 11 and the lower mold 12 from the optical element 17 will be described.

Optical material 1 heated to a predetermined temperature in a heating furnace
7a is held by the conveying member 20 and conveyed between the upper and lower dies 11, 12, and drives the cylinders connected to each other to start the ascending die 23 and the outer die 24 synchronously (see FIG. 11). .

Further, the nesting mold 23 and the outer mold 24 are raised synchronously, and the optical material 17a held by the conveying member 20 is further pushed up on the top surface of the nesting mold 23 and the outer mold 24, thereby forming the upper mold. Press in cooperation with 11. At this time, the optical material 17a
Is parting line 1 partly due to glass flow
6 and minute burrs are formed (see FIG. 12).

After the pressing of the optical element 17 by the upper mold 11 and the lower mold 12 is completed, only the outer mold 24 is lowered while the optical element 17 is held between the upper mold 12 and the nesting mold 23, and the optical element 17 is The mold is released from the outer mold 24 (see FIG. 13). At this time, the outer mold 24 moves in a direction away from the minute burrs formed on the parting line 16, that is, in a direction in which no force acts on the burrs. No cracks or chips are generated.

Thereafter, the nest 23 and the outer mold 24 are lowered synchronously, and the release ring 1 is synchronized with this lowering.
3 is lowered to release the optical element 17 from the upper mold 11 (see FIG. 14).

Further, the nesting mold 23 and the outer mold 24 are lowered to bring the optical element 17 into contact with the step 21 of the conveying member 20, and the release ring 13 is raised to return to the original position (FIG. 15). reference).

Further, from the state described above, the nest 23 and the outer mold 2
4, the optical element 17 is moved to the step 2
1 and the release of the optical element 17 from the nest 23 is completed (see FIG. 16).

According to this embodiment, the same operation and effect as those of the first embodiment can be obtained without disposing a member such as a stopper around the lower mold. According to the release method of each embodiment,
For example, in molding of an irregularly shaped optical element which requires molding by a two-piece mold having a parting line on the molding surface, a mold release between a two-piece mold composed of an inner mold and an outer mold and the molded optical element is referred to as a nest mold. And the outer mold are separately performed, so that cracking and chipping of the optical element due to minute burrs generated on the parting line can be prevented, and as a result, molding quality of the optical element such as a lens is improved. In addition, even if it arrange | positions a two-body type | mold as a lower type | mold, mold release can be performed, exhibiting the said effect.

[0036]

As described above, according to the release method of the present invention, cracking and chipping of the optical element caused by minute burrs generated on the parting line can be prevented, and as a result, an optical element having good molding quality can be obtained. Can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state in which a two-piece nesting mold, which is one step of the mold releasing method of the present invention, is released.

FIG. 2 is a cross-sectional view showing a state in which an optical element is pressed and formed by a one-piece mold and a two-piece mold.

FIG. 3 is a cross-sectional view showing a state in which a two-piece outer mold, which is one step of the mold release method of the present invention, is released.

FIG. 4 is a cross-sectional view showing a state in which the outer mold and the upper mold are further released after releasing the insert mold, which is one step of the release method of the present invention.

FIG. 5 is a sectional view showing a state before optical element molding in Example 1 of the present invention.

FIG. 6 is a cross-sectional view showing a state when an optical element is molded in Example 1 of the present invention.

FIG. 7 is a cross-sectional view illustrating a release state of an upper mold according to the first embodiment of the present invention.

FIG. 8 is a cross-sectional view showing a state where the lower mold is lowered in order to release the lower mold in the first embodiment of the present invention.

FIG. 9 is a cross-sectional view showing a state in which a lower nest type is released from the mold in the first embodiment of the present invention.

FIG. 10 is a cross-sectional view showing a state in which mold release of the optical element has been completed in Example 1 of the present invention.

FIG. 11 is a cross-sectional view showing a state before an optical element is formed in Example 2 of the present invention.

FIG. 12 is a cross-sectional view showing a state when an optical element is molded in Example 2 of the present invention.

FIG. 13 is a cross-sectional view illustrating a state in which a lower outer mold is released from the mold according to the second embodiment of the present invention.

FIG. 14 is a cross-sectional view illustrating a release state of an upper mold in Example 2 of the present invention.

FIG. 15 is a cross-sectional view illustrating a state where an optical element is mounted on a transport member in Embodiment 2 of the present invention.

FIG. 16 is a cross-sectional view showing a state in which mold release of an optical element has been completed in Example 2 of the present invention.

FIG. 17 is a sectional view showing an illumination lens.

FIG. 18 is a perspective view showing an illumination lens.

FIG. 19 is a cross-sectional view showing a one-piece mold for molding the illumination lens.

FIG. 20 is a cross-sectional view showing a two-piece mold capable of molding the illumination lens.

FIG. 21 is an enlarged partial cross-sectional view showing burrs generated on an optical element formed by a two-piece mold.

FIG. 22 is an enlarged partial cross-sectional view showing a state where an optical element is released from a two-body mold by a conventional release method.

[Explanation of symbols]

 2 2 body type 3 Nested type 4 Outer type 6 Parting line 7 Optical element

Claims (1)

(57) [Claims] 1. A mold having a parting line on a molding surface.
After molding the optical element using the body, one of the two bodies is released from the optical element, and then the other of the two bodies is released from the optical element. Release method.