JP2975862B2 - Disk manufacturing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk, such as an optical disk or a magneto-optical disk, provided with a data information recording area near the center hole of the disk, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, as a recording medium for recording digital data such as audio, video, image, and computer data,
Optical disks are becoming mainstream. Optical discs have various sizes depending on the recording media. For example,
Discs represented by audio are compact discs with a straight line of 120 ± 0.3 mm or 80 ± 0.3 mm, and images and computer data are CD-CDs with a straight line of 120 ± 0.3 mm.
ROM and the like exist.

An optical disk manufacturing apparatus of this type will be described with reference to FIGS. FIG. 9 shows a mold for manufacturing a conventional optical disk (a compact disk having a diameter of 120 mm).
A stamper on which data is recorded down to mm is fixed by a stamper outer peripheral holder 19a and a stamper inner diameter holder 19b. Reference numeral 12 denotes a replica disk which is an optical disk of the formed product. F is a fixed mold having a mirror block 13 having a mirror surface for fixing the stamper 11, and G is a movable mold having a mirror block 14 having a mirror surface onto which a heat-melted molding material is injected. Reference numeral 15 denotes an injection port for injecting the heat-melted molding material, and 16 denotes an injection port 15.
And a center hole (through hole) 3 having an inner diameter of 15 mm to 15.1 mm (in the case of a compact disc).
The cylindrical sprue bushing 17 for forming 2 is provided with a cut pin 18 described later in the center, and forms a center hole (through hole) 32 having an inner diameter of 15 mm to 15.1 mm (in the case of a compact disc). The cut pin 18 of the cylindrical body to be performed is provided at the center of the cut pin 17,
This is a rod-shaped sprue ejector for removing a sprue S described later from the replica disk 12. Sprue ejector 18
Is usually provided so as to be slightly concave by the tip of the cut pin 17. That is, the space K is provided. still,
The sprue bush 16, the cut pin 17, and the sprue ejector 18 can move in the direction of arrow H.

[0004] The disk forming process of the conventional optical disk manufacturing apparatus is as follows. First, in a state where two dies, that is, a fixed die F and a movable die G are opened (FIG. 10), a data transfer surface (information The holder 19 is attached to the mirror surface 13a of the mirror block 13 of the fixed type F so that the recording area is outside.
Fix with. Then, the movable mold G is slid toward the fixed mold F, and the two molds are abutted to be integrated. A molding material melted by heat, for example, a resin such as polycarbonate, is injected from the injection port 15 into the disc forming gap portion (FIG. 9).
The shape of the replica disk at this time is shown in FIG. When the molding material is filled in the space between the data transfer surface of the stamper 1 of the fixed mold F and the mirror surface 14b of the mirror block 14 of the movable mold G, the molding material is injected by the injection pressure of the molding material at that time. Is transferred to the interface between the stamper 1 and the molding material.
The sprue bush 16, the cut pin 17, and the sprue ejector 18 are moved in the direction of the arrow I before the hot melted molding material has cooled down from the injection port 15 to form a center hole (FIG. 11c). At this time, the distance between the sprue bush 16, the cut pin 17, and the sprue ejector 18 does not change. Next, the disk-forming gap is filled and cooled to cure the molding material.

[0005] Thereafter, the movable mold G moves to the right side in the figure to open the mold. At the same time, the sprue bush 16 moves in the direction of the arrow J until the tip is at the same position as the mirror surface 14b of the mirror block 14, and returns to the original position. Next, the sprue ejector 18 is further moved in the direction of arrow I, and the sprue S is removed from the replica disk 12 (d in FIG. 11). The sprue is a forming material portion used for the injection port 5 and the center hole portion with the disk molding, and is an unnecessary portion. When the sprue S is removed, the cut pin 17 and the sprue ejector 18 move in the direction of arrow J and return to their original positions. As a result, the data recorded on the stamper 1 is transferred, and the replica disk 2 having a hole at the center is
That is, the optical disk having the center hole is taken out.

FIG. 12 shows an example of a conventional optical disk thus taken out. FIG. 12 is a plan view of a compact disk molded by a general injection molding method. FIG.
As shown in FIG. 2, most of the dies used for mass production with respect to the area of the information recording area 31 in the hatched portion of the disk main body 30 have inner diameters of 15 mm to 15 mm stipulated by the International Electrotechnical Commission (IEC). Hole punching of a center hole (through hole) 32 having a diameter of 1 mm (in the case of a compact disc) is performed during molding. The recording start position 33 of the information recording area has an inner diameter of 46 mm.

[0007]

The conventional disk manufacturing apparatus has a problem that the number of working steps is increased because a center hole punching operation occurs at the time of forming the disk. Also, the part corresponding to the center hole part,
That is, there is a problem that a molding material in a sprue portion is wasted.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to reduce the number of work steps for manufacturing a disk and to prevent the generation of useless disk molding material.

[0010]

A first aspect of the present invention is a first mold for supporting a stamper, and the first mold facing the first mold.
A second mold forming a disc molding space together with the first mold, and a center hole of the disc supported by the second mold and having a point contacted with the stamper or the first mold. And a resin injection body that defines an inner circumference and has a resin injection gate facing the inner circumference of the center hole.

[0011] The second aspect of the present invention is characterized in that the resin injection body is provided with the second resin injection body.
A cylindrical body is provided at the center of the mold so as to be able to advance and retreat in a direction facing the first mold, and has a size for defining the inner diameter of the disc, and a space for resin injection is provided in the cylindrical body. And a resin injection valve having a funnel-shaped end in contact with the first mold.

[0012]

[0013]

According to the first aspect, the resin injection body supported by the second mold is brought into contact with the first mold, and the injection gate of the resin injection body is controlled to control the first and second molds. , And the injected resin is cooled to form a disk. Claim 2
In the above, gate control is performed by a cylindrical body defining the inner diameter of the disk supported by the center of the second mold and a resin injection valve having a funnel-shaped tip, and the gap between the first and second molds is controlled. The disk is formed by controlling the amount of resin injected into the disk.

[0014]

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a disk manufacturing apparatus according to the present invention will be described. FIG. 1 is a structural diagram of a mold for explaining a method of manufacturing an optical disk having a recording area up to the vicinity of a center hole according to an embodiment of the present invention. 2 to 7
FIG. 3 is an explanatory view showing a disk forming process using the mold of FIG. 1. In particular, FIG.
4 is an explanatory view showing a state where the movable mold and the fixed mold are closed, FIG. 4 is an injection / cooling state, FIG. 5 is a view showing a state where the movable mold and the fixed mold are opened, and FIG.

In FIG. 1, reference numeral 1 denotes a stamper on which data is recorded up to the vicinity of a center hole, and reference numeral 2 denotes a replica disk serving as an optical disk of a molded product. A is provided with a positioning projection 1a at the center of the stamper 1.
Is a movable mold having a movable mirror block 3 having a mirror surface 3a for fixing the mold, B is a fixed mold having a fixed mirror block 4 having a mirror surface 4b into which a molten molding material is injected, and 5 is a hot melt. A resin injection path for guiding the formed molding material to the resin injection gate; and 6, a mirror surface 3 a of the movable mirror block 3.
A stamper suction port for suction-fixing the stamper 1 by vacuum vacuum or the like, and a part 7 forms a part of a resin injection path 5 for injecting a molding material, and has an inner diameter of 15 mm to 15.1 mm.
A cylindrical hole defining cylinder for forming a center hole (through hole) 32 having a diameter of (in the case of a compact disc) 32, a part 8 of a resin injection path 5 for injecting a molding material, and a tip part having a funnel shape Formed as a resin injection gate valve,
The tip 8a is a central guide valve (resin injection valve) 8 which abuts the stamper 1.

The structure of the stamper 1, the hole defining cylinder 7, the central guide valve 8, and the injection path 5 will be described in detail with reference to FIG. The flat portion 8a of the central guide valve 8 is abutted so as to make surface contact with the stamper 1 or the positioning protrusion 1a. The pointed end portion 7a of the hole defining cylinder 7 is formed to be inclined, and is in surface contact with the inclined portion 8b of the central guide valve 8 so as to be separated. An interval of about 1 mm is provided between the support rod 8c of the central guide valve 8 and the hole defining cylinder 7, and forms a resin injection path 5 for guiding the heat-melted molding material to the resin injection gate. The hole defining cylinder 7 can move in the direction of arrow C. Incidentally, in the claims, the one composed of the hole defining cylinder (cylindrical body) 7 and the central guide valve (resin injection valve) 8 is referred to as a resin injection body.

In this embodiment, the end 8a of the central guide valve 8
Is in planar contact with the stamper 1 or the positioning projection 1a, but may be in line contact with the end 8a in a hollow state. Next, a process of forming an optical disk according to an embodiment of the present invention will be described with reference to FIGS.

First, in a state where the two dies, that is, the movable mold A and the fixed mold B are opened (FIG. 2), the data is obtained by the operation of the positioning projection 1a having the center of the stamper 1 and the vacuum vacuum of the stamper suction port 6. Transfer surface (information recording area)
Is fixed to the mirror surface 3a of the movable-side mirror block 3 of the movable mold A so that the outer side is located outside. Then, the movable mold A is slid toward the fixed mold B, and the two molds are abutted to be integrated (FIG. 3). At this time, the flat portion 8a of the central guide valve 8 is abutted so as to make surface contact with the stamper 1 or the positioning projection 1a. Then, the hole defining cylinder 7 of the cylindrical body is movable in the D direction,
From the resin injection path 5 and the resin injection gate, a molding material melted by heat, for example, a resin such as polycarbonate, is injected into the disk forming gap portion 9 (FIG. 4). At this time, the tip of the hole defining cylinder 7 is the mirror surface 4 of the fixed-side mirror block 4 of the fixed type B.
(b in FIG. 4) (the point where the point of the hole defining cylinder 7 is the same as the mirror surface 4b). Disc forming gap 9 formed by the data transfer surface of the movable type A stamper 1 and the mirror surface 4b of the fixed side mirror block 4 of the fixed type B
Is filled with the molding material, the data recorded on the stamper 1 is transferred to the boundary surface between the stamper 1 and the molding material by the injection pressure of the molding material at that time. The hole defining cylinder 7 is moved in the direction E before the molding material melted from the resin injection path 5 and the resin injection gate is completely cooled, and the inclined portion 8b of the central guide valve and the inclined portion of the hole defining cylinder 7 are inclined. 7a and the pointed end of the hole defining cylinder 7 also abuts the stamper 1 to close the resin injection gate (FIG. 1). Next, the disk forming gap portion 9 is filled and cooled to cure the molding material.

Thereafter, the movable mold A moves to the left side in the figure,
The mold is opened (FIG. 5), the data recorded on the stamper 1 is transferred, and the replica disk 2 having a hole at the center, that is, the optical disk having a center hole is taken out (FIG. 6). According to such an optical disc manufacturing method, the hole defining cylinder 7 is moved when the heat-melted molding material is filled in the disc forming gap portion 9, and the pointed end of the hole defining cylinder 7 abuts the stamper 1, After that, the molding material is cooled to harden, so that a hole is formed in the center when the mold is opened. Therefore, it is necessary to punch the center hole 32 during the formation of the disk as in the conventional case. Disappears. In addition, since the resin injection gate is located at the center of the stamper 1, the injection pressure is dispersed over the entire circumference and the specific vector force does not increase, so that the injection molding can be performed without moving the stamper 1. .

In the present embodiment, the tip of the central guide valve is formed in a funnel shape, the tip 7a of the hole defining cylinder 7 is formed to be inclined, and the inclined portion of the central guide valve 8 is formed. 8b so as to be separated from the center hole (through hole) 32 as shown in FIG.
It is sufficient that the resin injection path 5 is formed and a mechanism of a resin injection gate is provided.

FIG. 7 shows an example of the optical disk thus taken out. FIG. 7 is a plan view of an optical disk manufactured by a method for manufacturing an optical disk capable of providing a recording area up to the vicinity of a center hole according to an embodiment of the present invention. In FIG. 7, the hatched portion on the plane of the optical disk main body 30 is an information recording area (recording surface or transfer surface) 31 onto which the data recorded on the stamper 1 is transferred, and this region extends to the vicinity of the center hole 33 (inner diameter 35 mm). Is recorded, and a center hole 32 is provided. Here, the inner diameter is 15 mm to 15.1 mm (in the case of a compact disc). It is possible to record data as close as possible to the center hole 32, and it is possible to provide a recording area up to a position of radius 7.5 + αmm (α = accuracy margin + beam diameter).
When polycarbonate is used as a molding material, which is currently used for many compact discs, in reality, the inner diameter is 2
Since 0 mm or more has large birefringence and is not suitable as a substrate for an optical disk, an information recording area can be provided from an inner diameter of 30 mm. In the present embodiment, the inner diameter is 35 m with more margin.
An information recording area is provided from m. When a material having a small birefringence such as a polyolefin resin or a PMMA resin is used as the molding material, the information storage area can be further provided to the inner peripheral side.

Next, FIGS. 7 and 9 show the increase in the recording area between the replica disk and the conventional optical disk formed by the method for manufacturing an optical disk capable of providing a recording area near the center of the present invention. It will be described using FIG.
In FIG. 9, for example, if it is a conventional compact disc of 120 ± 0.3 mm, the information recording area indicated by the hatched portion is the International Electrotechnical Commission (IEC 90).
8; 1987) and Japanese Industrial Standards (JIS S-860).
According to the standard of 5-1993), the recording start position is a radius of 23 mm from the center, and the storage end position is a radius of 5 mm from the center.
8.5 mm. Therefore, the area of the information recording area is about 9089 mm ² . On the other hand, as shown in FIG. 7, if the recording start position is a radius of 17.5 mm from the center and the recording end position is a radius of 58.5 mm from the center, as shown in FIG. The area of the information recording area is about 9789 mm ² , and the area of the information recording area is increased by about 8% as compared with the conventional disk. Therefore, in the case of music, the number is increased by one or two songs, and the recording area is further expanded.

If the disc is an 80 ± 0.3 mm compact disc, the information recording area indicated by oblique lines has a recording start position with a radius of 23 mm from the center and a storage end position with a radius of 38 mm from the center. is there. Therefore,
The area of the information recording area is about 2875 mm ² . On the other hand, in the information recording area of the embodiment of the present invention, as shown in FIG. 7, the recording start position has a radius of 17.5 mm from the center.
If the recording end position has a radius of 38 mm from the center, the area of the information recording area is about 3574 mm ² , and the area of the information recording area is about 24 mm as compared with the conventional disk.
% Increase.

What has been described above has a diameter of 130 ± 0.
It goes without saying that it can be used for a 3 mm disc or a disc having a diameter of 150 ± 0.3 mm. Needless to say, the disk according to the present invention can be applied to a rewritable optical disk such as a read-only optical disk, a write-once optical disk, or a magneto-optical disk or a phase-change optical disk.

[0026]

According to the first aspect, since the center hole is formed by the resin injection body at the time of resin injection, the number of working steps can be reduced. Further, there is no loss of material at the time of molding the disc, the production cost can be suppressed, and this is effective for mass production. In claim 2, since the resin injection port is located at the center of the stamper, the injection pressure from the injection port is dispersed over the entire circumference,
A disk can be formed uniformly, the distortion is small, and the birefringence characteristics are improved as compared with the conventional one.

[0027]

[Brief description of the drawings]

FIG. 1 is a structural view of a mold for explaining a method of manufacturing an optical disk having a center hole (through hole) at a center portion and an information recording area up to the vicinity of the center hole in one embodiment of the present invention.

FIG. 2 is an explanatory view showing a process of forming a disk by the mold of FIG. 1 with a movable mold and a fixed mold opened.

FIG. 3 is an explanatory view showing a process of forming a disk by the mold of FIG. 1 in a state where a movable mold and a fixed mold are closed.

FIG. 4 is an explanatory view of an injection / cooling state showing a disk molding process by the mold of FIG. 1;

FIG. 5 is an explanatory view showing a process of disk molding by the mold of FIG. 1 in a state where a movable mold and a fixed mold are opened after molding.

FIG. 6 is an explanatory diagram of a state of taking out the optical disk, showing a process of forming a disk by the mold of FIG. 1;

FIG. 7 is a plan view of an optical disc manufactured by a method for manufacturing an optical disc having a center hole (through hole) in the center and an information recording area up to the vicinity of the center hole in one embodiment of the present invention.

FIG. 8 is a diagram illustrating a method of manufacturing an optical disk having an information recording area up to a center hole by forming a center hole (through hole) at a center portion according to an embodiment of the present invention; FIG. 6 is a structural view of another embodiment of a resin injection gate to be used.

FIG. 9 is a structural view of a mold for explaining a conventional method of manufacturing an optical disk.

FIG. 10 is an explanatory view showing a process of forming a disk by the mold of FIG. 9 with the movable mold and the fixed mold opened.

FIG. 11 is a diagram showing a conventional optical disc molding process.

FIG. 12 is a plan view of a conventional optical disc.

[Explanation of symbols]

 A, G Movable B, F Fixed type 1, 11 Stamper 2, 12 Replica disk 3a, 14b Movable mirror surface 4b, 13a Fixed mirror surface 5 Resin injection path 6 Stamper suction port 7 Hole defining cylinder 8 Central guide valve 15 Injection port Reference Signs List 16 sprue bush 17 cut pin 18 sprue ejector 19a, 19b stamper holder 30 optical disc main body 31 information recording area 32 center hole (through hole) 33 information recording start position

Continuation of the front page (56) References JP-A-5-6572 (JP, A) JP-A-5-293869 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G11B 7 / 26 B29C 45/26

Claims (2)

(57) [Claims] A first mold supporting a stamper; a second mold facing the first mold to form a disk molding space together with the first mold; While being supported by a mold, with the tip abutted on the stamper or the first mold, the inner periphery of the center hole of the disk is defined, and a resin injection gate is provided facing the inner periphery of the center hole. An apparatus for manufacturing a disk, comprising: a resin injection body; 2. The resin injection body according to claim 1, wherein the resin injection body is provided at a central portion of the second mold so as to be able to advance and retreat in a direction facing the first mold, and defines an inner diameter of the disk. A disk having a space for resin injection in the cylindrical body, and a resin injection valve having a funnel-shaped end contacting the first mold. Manufacturing equipment.