JPH09306043A - Optical disk forming device and optical disk forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the deterioration of the flatness of a sticking reference surface due to a flash to be generated on a disk substrate by more protruding the internal diameter side of a stamper supporting surface than a data recording surface to the thickness direction of the disk. SOLUTION: An optical disk forming device is consisting of a pair of metallic molds 12, 13 and a disk substrate is injection-molded in cavities of the molds. Then, a stamper 15 forming a data recording surface on one surface of the disk substrate is supported in the cavity 12a. When the stamper 15 is pressed on the one surface of the substrate by an injecting pressure, the data recording surface is formed on the disk substrate and the internal diameter side of the disk is more dented than the data recording surface to the thickness direction of the disk. The internal diameter side of a stamper supporting surface 12b is more protruded than the data recording surface to the thickness direction of the disk.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk molding apparatus for injection molding a bonded optical disk and an optical disk molding method using the same.

[0002]

2. Description of the Related Art A bonded optical disc is constructed, for example, as follows. That is, a data recording surface is formed on one surface of a translucent disk substrate such as polycarbonate. On this data recording surface, a pit representing data to be recorded is formed by a stamper on one surface of the disk substrate, and an aluminum film is formed thereon as a reflective film by sputtering.

The disk substrate has a diameter of 120 mm and a thickness of about 0.6 mm. Although it is desirable to reduce the thickness of the disc substrate in order to increase the density, it is necessary to set the thickness of the optical disc to 1.2 mm in consideration of the unification of optical disc devices.

Therefore, on the data recording surface,
A translucent dummy substrate having a thickness of about 0.6 mm is attached through the adhesive layer. Since the reflective film on the data recording surface is protected by the disk substrate and the dummy substrate, it is unlikely to be mechanically damaged from the outside and a long life can be obtained. Then, label printing showing recorded contents is applied to the surface of the dummy substrate.

Conventionally, a bonded optical disk is molded by an optical disk molding apparatus as shown in FIG.
As shown in the figure, the optical disk molding apparatus 1 is provided with a fixed mold 2 and a movable mold 3, and these cavities 2a, 3a are provided.
The disk substrate is injection molded inside. Molten resin such as polycarbonate is injected from an injection pipe 4 at the center of the movable mold 3, and a stamper 5 for molding a data recording surface is supported in the cavity 2a of the fixed mold 2.

The stamper 5 has a ring-shaped flat plate shape and is sucked by the ring-shaped suction 6 and suction pipes 7 arranged at equal intervals in the circumferential direction,
It is supported so as to contact the stamper support surface 2b of the cavity 2a. The stamper 5 is pressed against one surface of the disk substrate by the injection pressure to form a data recording surface.

[0007]

By the way, in the conventional optical disk molding apparatus 1, as shown in FIG. 6, when the disk substrate 8 is separated from the stamper 5 after injection molding, the disk substrate 8 is moved to the inner diameter side. Burrs 9 occur. Since the burrs 9 project outward in the disc thickness direction from the data recording surface 9 of the disc substrate 8, the burrs come into contact with each other when the disc substrates are bonded, and the flatness of the reference surface deteriorates. was there.

On the other hand, if the burr 9 is to be made smaller, the center hole of the stamper 5 needs to be more accurate, which makes it difficult to control the cutting edge of the die and lowers the operating rate.

Further, since post-processing or the like for removing the burr 9 is required, there is a problem that the manufacturing cost increases and the yield and the operating rate decrease.

The present invention has been made to solve the above-mentioned problems, and can prevent deterioration of the flatness of the bonding reference surface, easily manage the cutting edge of the mold, and remove burrs on the disk substrate. SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical disk molding apparatus that does not require post-processing to do so, and an optical disk molding method using the same.

[0011]

According to the present invention, there is provided a pair of metal molds for injection-molding a disk substrate in a cavity, and at least one of the molds is supported in the cavity.
And a stamper for molding the data recording surface, and the inner diameter side of the stamper supporting surface of the cavity is achieved by an optical disk molding device projecting inward in the disk thickness direction from the data recording surface.

Further, according to the present invention, the above object is to provide a stamper in which at least one cavity of a pair of molds has an inner diameter side protruding inward in a disc thickness direction from a molding portion of a data recording surface. Is achieved by the method of molding an optical disk such that the disk substrate is injection molded.

Further, a stamper for molding the data recording surface is supported in at least one cavity of the pair of molds, and the inner diameter side of the stamper is made thicker than the data recording surface by the injection pressure at the time of molding the disk. This is achieved by the optical disc molding method such that the disc substrate is injection-molded by projecting inward in the depth direction.

According to the present invention, the inner diameter side of the stamper supporting surface of the cavity projects inward in the disc thickness direction from the data recording surface. Then, the stamper supported by the stamper supporting surface is preformed in a shape along the stamper supporting surface, or is formed in a shape along the stamper supporting surface by injection pressure at the time of disc molding. . Therefore, even if the disc substrate is removed from the stamper after injection molding and a burr is generated on the inner diameter side of the disc substrate, the data recording surface is molded higher than this burr, and the flatness of the reference surface is not deteriorated.

[0015]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. The embodiments described below are preferred examples of the present invention, and therefore, various technically preferable limitations are given. However, the scope of the present invention particularly limits the present invention in the following description. The embodiment is not limited to these embodiments unless otherwise stated.

FIG. 1 is a schematic view showing an embodiment of an optical disk molding apparatus according to the present invention. As shown in the figure, the optical disk molding apparatus 11 of the present embodiment includes a pair of molds 1
2, 13 and their cavities 12a, 13
The disk substrate is injection-molded in a. In the present embodiment, one mold 12 is a fixed mold and the other mold 13 is a movable mold. However, the present invention is not limited to this, and both molds may be movable.

An injection pipe 14 for injecting a molten resin such as polycarbonate into a space inside the combined cavities 12a and 13a is provided at the center of the fixed mold 12. On the other hand, in the cavity 12a of the solid mold 12, a stamper 1 for molding a data recording surface on one surface of the disk substrate is formed.
5 are supported.

The stamper 15 has a ring-shaped flat plate shape, and a pit replica of a data recording surface is formed on the surface thereof. The inner peripheral surface of the stamper 15 is sucked by the ring-shaped suction 16, and the outer peripheral edge of the stamper 15 is held by the supporting claws 17 attached to the fixed die 12, so that the stamper supporting surface 1 of the cavity 12a is held.
It is supported so as to be close to 2b.

As shown in FIG. 2, the inner diameter side of the stamper support surface 12b projects inward in the disc thickness direction from the data recording surface. Therefore, the stamper 15 has the stamper support surface 12 as will be described later.
It is preliminarily molded into a shape along b, or is molded at the time of injection molding.

The movable die 13 is formed with a support pawl receiving portion 18 for accommodating the support pawl portion 17 protruding from the fixed die 12, and when the support pawl portion 17 is accommodated in the support pawl receiving portion 18. Then, the fixed mold 12 and the movable mold 13 are combined. Further, in the center of the movable die 13, a tubular push-out member 19 for taking out the molded disk substrate when the movable die 13 is retracted and released is provided so as to be able to move forward and backward.

The optical disk molding apparatus 11 is configured as described above, and the optical disk molding method according to the embodiment of the present invention is performed using the optical disk molding apparatus 11.
That is, in the optical disc molding method according to the present invention, first, the movable die 13 is advanced so that the support claw portion 17 is accommodated in the support claw receiving portion 18, and then the fixed die 12 and the movable die 1 are moved.
Combine with 3. And the cavities 12a, 13a
The resin melted by the injection molding machine is poured from the injection pipe 14 at a preset pressure into the space defined by the above, and the disk substrate is injection-molded. As the resin material, it is possible to employ, for example, polycarbonate and acrylic having translucency.

Then, as shown in FIG. 3, the stamper 15 is plastically deformed by the injection pressure at the time of disk molding and is molded into a shape along the stamper supporting surface 12b. Alternatively, the stamper 15 may be preformed in a shape along the stamper support surface 12b.

That is, the stamper 15 has a shape in which the inner diameter side of the stamper 15 projects inward in the disc thickness direction from the data recording surface along the stamper support surface 12b. Therefore, when the stamper 15 is pressed against one surface of the disk substrate 20 by the injection pressure, a data recording surface is formed on the disk substrate 20, and the inner diameter side is recessed inward in the disk thickness direction from the data recording surface. .

After the disk substrate 20 is solidified and cooled, the movable mold 13 is retracted to open the mold, the pushing member 19 is projected into the cavity 13a, and the disk substrate 20 is taken out. When the disc substrate 20 is detached from the stamper 15, a burr 21 is generated on the inner diameter side of the disc substrate 20, but in the present embodiment, the data recording surface is formed higher than the burr 21. The flatness of the reference plane does not deteriorate. Therefore, as shown in FIG. 4, even if the disk substrates 20 and 20 are bonded to each other, the burr 21 is positioned lower than the bonding reference surface, and therefore good bonding can be performed.

Thus, according to the present embodiment, the inner diameter side of the stamper support surface 12b of the cavity 12a projects inward in the disc thickness direction from the data recording surface and is supported by this stamper support surface 12b. The stamper 15 is preformed in a shape along the stamper support surface 12b, or is formed in a shape along the stamper support surface 12b by the injection pressure at the time of disk molding. Therefore, after the injection molding, the disc substrate 20 is separated from the stamper 15, and the disc substrate 2 is removed.
Even if the burr 21 is generated on the inner diameter side of 0, the burr 21 is positioned lower than the bonding reference surface, and therefore the flatness of the reference surface does not deteriorate. Further, it is easy to control the inner diameter size and shape of the stamper 15 and the blade edge of the die, and post-processing for removing burrs on the disk substrate is not necessary.

Further, since the center hole of the stamper 15 does not require excessive precision, it becomes easy to control the cutting edge of the die, and the operating rate can be improved. Further, since it is not necessary to remove the burr 21, post-processing or the like for removing the burr 21 is not necessary, the manufacturing cost can be reduced, and the yield and the operating rate can be improved.

[0027]

As described above, according to the present invention, it is possible to prevent the flatness of the bonding reference plane from being deteriorated,
It is possible to provide an optical disk molding apparatus in which the cutting edge of a mold can be easily managed and post-processing for removing burrs on a disk substrate is unnecessary, and an optical disk molding method using the same.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of an optical disc molding apparatus according to the present invention.

FIG. 2 is a schematic diagram showing a main part of an optical disc molding apparatus according to the present embodiment.

FIG. 3 is a schematic view showing a molded state of a disc substrate in the present embodiment.

FIG. 4 is a schematic view showing a state in which the disk substrates are stuck to each other in the present embodiment.

FIG. 5 is a schematic view showing a conventional optical disc molding apparatus.

FIG. 6 is a schematic view showing a disk substrate molded by a conventional optical disk molding apparatus.

[Explanation of symbols]

11 ... Optical disk molding apparatus, 12 ... Mold (fixed mold), 12a ... Cavity, 13 ... Mold (movable mold), 13a ... Cavity, 14 ... Injection tube, 1
5 ... Stamper, 16 ... Suction, 17 ...
-Support claw portion, 18 ... Support claw receiving portion, 19 ... Push member, 20 ... Disk substrate, 21 ... Burr

Claims (5)

[Claims] 1. A pair of molds for injection-molding a disk substrate in a cavity, and a stamper supported in at least one of the cavities and molding a data recording surface, wherein an inner diameter of a stamper supporting surface of the cavity. An optical disk molding apparatus, wherein the side projects inward in the disk thickness direction from the data recording surface. 2. The optical disk molding apparatus according to claim 1, wherein the stamper is preliminarily molded into a shape along the stamper supporting surface. 3. The optical disk molding apparatus according to claim 1, wherein the stamper is molded into a shape along the stamper supporting surface by an injection pressure at the time of molding the disk. 4. A stamper, the inner diameter side of which is projected inward in the disc thickness direction from the molding portion of the data recording surface, is supported in at least one cavity of a pair of molds,
A method of molding an optical disk, characterized in that a disk substrate is injection molded. 5. A stamper for molding a data recording surface is supported in at least one of the cavities of a pair of molds, and the inner pressure side of the stamper has a disk thickness larger than the data recording surface due to injection pressure during disk molding. A method of molding an optical disk, characterized in that the disk substrate is injection-molded by projecting inward in the depth direction.