JPS63112131A - Disc molding die assembly - Google Patents

Abstract

PURPOSE:To prevent a disc from deforming at the welding of a hub to the disc and consequently form the disc which develops neither birefringence nor skew, by a method wherein a part of the stamper holder of a movable side mold is extended to an ejector sleeve so as to cover the stamper side end part of a center member with the stamper holder. CONSTITUTION:A part, at which the through hole 38f of a stamper holder 38, forms an extended part 46, which protrudes to an ejector sleeve 41 side, when the holder is fitted to a center member 39. The upper end side of the center member 39 is covered by the extended part 46, which protrudes to the ejector sleeve 41 side of the stamper holder 38. Respective nesting lines 47, 48 and 49 locate only at the boundary part between the signal-recording part and the non-signal-recording part of a disc board, which is molded by a die assembly, and at an edge in the neighborhood of a center hole. The nesting lines 47, 48 and 49 do not face to nearly the whole region of the non-signal- recording part. The molding surface is realized by the stamper holder 38.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a mold device for molding a disk substrate of a disk on which a predetermined information signal is recorded, such as an optical disk or a magneto-optical disk, and in particular, the present invention relates to a mold device for molding a disk substrate of a disk on which a predetermined information signal is recorded, such as an optical disk or a magneto-optical disk. The present invention relates to a molding device that is useful when molding a disk substrate for a disk.

[Summary of the invention]

The present invention provides a disk molding device comprising a fixed side mold provided with a nozzle for injection of synthetic resin and a movable side mold provided with a stamper, in which at least the stamper is supported on a stamper support plate. stamper holder and
A center member is provided concentrically with the stamper holder and on the inner circumferential side of the stamper holder, and the position of the stamper holder is regulated. By extending a part of the stamper holder of the movable side mold to the ejector sleeve and covering the stamper side end of the center member with the stamper holder, The mounting of a smooth hub with a wide area in the center of the disk substrate as a molded product makes it possible to form a surface.

[Conventional technology]

Conventionally, a disk substrate of a write-once optical disk capable of recording a predetermined information signal is formed by molding a synthetic resin such as polycarbonate resin.

On the whole surface of this disk substrate, a signal recording section is formed by vaporizing aluminum or the like as a reflective film. A trunk guide groove is formed in advance to form a recording trunk in which information signals are recorded as a focused line.

As a molding apparatus for molding a disk substrate while forming such a guide groove, a molding apparatus constructed as shown in FIG. 5 has conventionally been used.

The mold device shown in FIG. 5 is equipped with a sprue pusher l having a nozzle at the tip for injecting synthetic resin supplied from a hopper into the cavity, and also works together with a movable mold to form a cavity 2 for molding a disk substrate. a fixed side mold 4 equipped with a fixed side mold plate 3 constituting the mold, and a movable side mold 6 equipped with a stamper 5 for forming predetermined track guide grooves on the disk substrate molded in the cavity 2. It is composed of. - The movable mold 6 in this mold vtW includes a stamper holder 8 that supports the stamper 5 on the stamper support plate 7, and a stamper holder 8 that is concentric with this stamper holder 8 and is provided on the inner peripheral side of the stamper holder 8. The installation involves a center member 9 that regulates the position, a punch 10 that is concentric with the center member 9 and punches a center hole in a molded disk substrate that is attached to the center member 9 so as to be able to move forward and backward, and the outer periphery of the punch 10. and an ejector sleeve 11 fitted concentrically with the punch 10 and movably attached to the center member 9 to eject and mold the disk substrate to be molded from the movable mold 6.

In order to mold a disk substrate in a mold apparatus equipped with the fixed side mold 4 and the movable side mold 6 configured as described above, the fixed side mold 4 and the movable side mold 6 are closed. Then, by injecting molten polycarbonate resin into the cavity 2 through the nozzle of the sprue foucher 1 and solidifying it, a guide groove corresponding to the guide groove formed in the stamper 5 is permanently formed. After the formed disk substrate is molded, a punch 10 that can move forward and backward with respect to the center member 9 is projected toward the gear upper tee 2 side to punch a center hole in the disk substrate. At the point where the center hole is drilled, the movable side mold 6 is separated from the fixed side mold 4 to open the cavity 2, and the ejector sleeve 11, which is attached to the center member 9 so as to be able to move forward and backward, is inserted into the movable side mold. It does not protrude from the mold 6 toward the fixed mold 4 side,
Due to this protrusion of the ejector sleeve 11, the molded disk substrate can be taken out from the mold '271, and the molding is completed.

[Problem that the invention seeks to solve]

The movable mold 6 in the conventional mold device described above has a puncher opening for punching the center hole of the disk substrate, an ejector sleeve 11 for ejecting and handling the disk substrate from the movable mold 6, and a stamper holder 8 for mounting. The structure is such that up to the center member 9 that regulates the position faces the cavity 2' side, that is, the molding surface side of the disk substrate.

Therefore, on the molding surface of the movable mold 6, as shown in FIG.
will come.

By the way, the stamper holder 8, the center member 9,
It is extremely difficult to incorporate each member of the punch 10 and the ejector sleeve 11 between the nested wires 12 without completely eliminating the step. Therefore, several grooves 14 are formed in the disk substrate 13 molded by the mold apparatus at positions corresponding to the nested wires 12, as shown in FIG.

The nested wire 12 is located on the inner peripheral side of the stamper 5 forming the guide groove, and in the non-signal recording portion of the disk substrate 13. In this non-signal recording section,
When configured as a disk, a hub is attached that serves as an attachment part to a disk rotation drive device that rotates the disk. That is, as shown in FIG. 7, the disk 15 is made by depositing a reflective film 1G of aluminum or the like on the surface of the disk substrate 13 molded by the molding device, on which the X inner groove is formed by the stamper 5. Furthermore, a protective film 17 made of synthetic resin is provided on the reflective film 16. In the non-signal recording portion 18 on the side of the disk 15 opposite to the surface on which the protective film 17 is formed, that is, on the surface where the guide groove of the disk substrate 13 and the groove 14 formed by the nested wire 12 are not formed, A hub 20 made of synthetic resin is welded to the hub 20, which is provided with a metal plate 19 that can be attracted to a magnet 7 provided on the side of the rotational drive device.

This welding of the hub 20 is carried out on a flat surface as shown in FIG.
The disk 15 is placed 51 on the mounting table 21 having an E32i surface.
! Then, the hub 20 is placed on the disk 15 at a position corresponding to the non-signal recording section 18 in which the groove 14 formed by the nested wire 12 is formed, and the welding horn 22 is pressed from above the hub 20. This is done by melting the welding lip provided on the When welding the hub 20, the disk 1
The portion having the groove 14 formed by the nested wire 12 of No. 5 is pushed out, and is deformed by receiving the pressing force of the welding horn 22 and receiving a displacement force such that it is bent upward from the storage table 21 side. . Following the deformation of the disk 15 as shown by the temporary line in FIG. 8, the hub 20 also receives a displacement force, causing internal stress.
If the disk 15 is welded to the disk 15 with internal stress, the disk 15 will be deformed by the stress of the hub 20.The laser beam is irradiated onto such a disk 15 to write the predetermined information 18 and/or the disk 15. Or when reading,
Birefringence occurs in the laser beam, resulting in good recording and reproducing characteristics. In addition, the disk 15 and the hub 20 may not be installed parallel to each other, and the disk 15 may not be rotated horizontally with respect to the rotating surface of the rotary drive device, resulting in a so-called skew, which also prevents good recording and playback. The characteristics will be obtained.

Therefore, the present invention prevents the formation of a large number of grooves due to the nested wires corresponding to the positions where the hub is attached, and allows the hub to be smoothly attached by welding to the surface.
It is an object of the present invention to provide a disk molding mold device that prevents the deformation of the disk that occurs during hub welding and enables the formation of a disk without birefringence or skew. be.

[Failure to solve the problem]

In order to solve the problems of the conventional apparatus as described above and to achieve the above-mentioned requirements, the present invention has a fixed side mold equipped with a nozzle for injection of synthetic resin and a stamper. In a disk molding mold device comprising a movable side mold, at least a stamper holder supporting the stamper on a standber support plate, and a stamper holder provided concentrically with the stamper holder and on the inner circumferential side of the stamper holder, the mounting of the stamper holder is provided. The stamper holder of the movable mold is composed of a center member for regulating the position of the stamper holder, and an ejector sleeve for ejecting a molded product, which is provided concentrically with the center member and can move forward and backward with respect to the center member. A portion of the stamper holder extends to the ejector sleeve, and the stamper holder covers an end of the center member on the standby side.

[Effect]

The disk molding mold device according to the present invention is a part of a stamper holder that extends to the ejector sleeve of the movable mold, and the stamper holder is attached to the stamper side end of the center member that regulates the position. By covering the stamper holder, it is possible to eliminate the occurrence of any nested wire between the nested wire of the ejector sleeve and the nested wire of the outer periphery of the stamper holder.

〔Example〕

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

The basic configuration of the disk molding mold device according to the present invention is as follows:
It has the same configuration as the conventional mold device described above, and as shown in FIG. A fixed side mold plate 33 is provided, which together with a side mold constitutes a cavity 32 for molding a disk substrate.A predetermined trunk guide groove is formed in the fixed side mold 34 and the disk substrate molded within the cavity 32. A movable mold 36 is provided with a stamper 35 for forming a mold.

The movable mold 36 in this mold apparatus includes a stamper holder 38 that supports the stamper 35 on a stamper support plate 37, and a stamper holder 38 that is concentric with this stamper holder 38 and is provided on the inner peripheral side of the stamper holder 38. is a center member 39 that regulates the position, and a center hole is punched in a disk substrate that is concentric with this center member 39 and is attached and molded so that it can move forward and backward with respect to the center member 39 (a punch 40 and a center hole of this punch 40 are formed). an ejector sleeve 41 that is fitted on the outer periphery concentrically with the punch 40 and is attached to the center member 39 so as to be freely retractable and ejects the molded disk substrate from the movable mold 36 to form a hill;
It is composed of.

The center member 39 is centered and attached to the movable mold 36, and the stamper 35 is attached to a receiving plate 43 positioned upwardly on the positioning step 42 on the lower side of the center member 39. A stamper support plate 37 is attached to support the stamper. The stamper 35 supported on the stamper support plate 37 is disposed with its inner peripheral side fitted to the upper end side of the center member 39, and is positioned on the positioning step 44 on the upper side of the center member 39. The upper end side outer Pi1r of the stamper holder 38 is attached to the center member 39 in a centered manner.
It is supported and fixed from above by a support flange portion 45 protruding from yJ.

By the way, the center member 39 is the stamper i! of the stamper support plate 37. The stamper holder fitting part is formed at a height that does not reach the li placement surface, has a tapered tip at the upper end, has a smaller diameter than the base end, and has a positioning step 44 formed at the base. 39a is provided. The stamper holder 38 fitted into the fitting part 39a is inserted into the fitting recess 3 corresponding to the fitting part 39a.
8a and an ejector sleeve 41 in the center.
It is formed into a cylindrical shape with a through hole 38b into which it fits almost tightly. That is, the through hole 38 of the stamper holder 38
The portion where b is drilled is an extension portion 46 that protrudes toward the ejector sleeve 44 side when fitted to the center member 39.
It becomes. In the stamper holder 38 formed in this way, the fitting recess 38a is fitted into the stamper holder fitting part 39a of the center member 39, the base end is positioned on the positioning step 44, and the through hole 38b is formed. It is inserted into the ejector sleeve 44 and attached as shown in FIG.

By fitting and arranging the stamper holder 38 formed as described above, the upper end side of the center member 39, which has a height that does not reach the stamper ei surface of the stamper support plate 37, is connected to the ejector sleeve 44 of the stamper holder 38 described above. It is covered by an extension portion 46 that protrudes to the side.

Therefore, as shown in FIG. 2, only the nesting wire 47 of the ejector sleeve 44 and the nesting wires 48 and 49 formed by the support flange portion 45 of the stamper holder 38 face the molding surface of the movable mold 36. . In other words, each nest &'147, 48, 49 is only located at the boundary between the signal recording part and the non-signal recording part of the disk substrate molded by this mold device and at the edge near the center hole, and Almost the entire area of the signal recording section is covered with the above-mentioned nested wire 47°4.
8.49 should not face (the molding surface by the stamper holder 38).

As shown in FIG.
The boundary between the signal recording part 52 where the trunk guide groove is formed and the non-signal recording part 53 formed by the upper end surface of the stamper holder 38 and the center where the upper end of the ejector sleeve 44 faces and which is punched out with the punch 40. hole 5
A groove 55 is only formed by the nested FI 47, 48.
The wide area at the center of 3 is a flat surface with no grooves formed at all. When the disk 54 is formed using the disk substrate 51 in the same manner as described above, the nested wire 47 is attached to the welding area of the hub 20 of the non-signal recording section 53.
．． 48.49 can be formed without exposing the groove 55.

The four hubs 20 welded here have a metal plate 19 for magnet attraction, similar to the one described above.

In order to weld the hub 20 to the disk 54 as described above,
As described above, as shown in FIG.
The hub 20 is placed on the welding area of the non-signal recording portion 53 of the disk 54, and the welding horn 22 is placed on the welding area of the non-signal recording portion 53 of the disk 54.
Even if the welding lip provided on the hub 20 is melted by pressing the welding lip, the nested wire 47,
Since the part having the groove 55 formed by 48.49 is not exposed at all, even if it receives the pressing force of the welding horn 22, it will not receive any force that would cause the disc 54 to deform. for,? No deformation that would cause JI refraction or skew occurs.

Note that a resin reservoir 40a of the runner is provided at the upper end of the center of the punch 40 provided in the movable side mold 36 to punch out the center hole of the disk substrate, and the resin in the resin reservoir 40a and the punch 40 are used to punch out the center hole of the disk substrate. A protruding rod 40b that protrudes a portion thereof is provided so as to be movable forward and backward.

Further, in the case of molding a disk substrate in which the center hole is formed by punching out the center hole after molding the disk substrate, it is not necessary to provide the punch 40.

Further, in the above-described embodiments, an apparatus for molding a disk substrate of a write-once optical disk is described.

However, the apparatus of the present invention can be widely applied to molding a disk substrate of a disk to which a hub is welded to the center.

〔Effect of the invention〕

As described above, the present invention is a part of the stamper holder that extends to the ejector sleeve of the movable mold, and the stamper holder is attached to the stamper of the center two members performing position W; t, lI. By covering the side edges,
It is possible to eliminate the occurrence of any nested wires between the nested wires of the ejector sleeve and the nested wires on the outer periphery of the stamper holder, and it is possible to form a disk in which no grooves due to the nested wires are exposed in the welding area of the hub. Then,
Smooth attachment of the hub enables welding to the surface, prevents deformation of the disk that occurs when the hub is welded, and allows formation of a disk without birefringence or skinny.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical sectional view of a disk molding mold device according to the present invention, FIG. 2 is a schematic plan view showing the molding surface side of the movable mold of the mold device, and FIG. is the above mold′!
FIG. 4 is a cross-sectional view of a main part of a disk substrate molded in position A, and FIG. 4 is a schematic cross-sectional view showing position B in which a hub is welded to a disk using the disk substrate. FIG. 5 is a schematic vertical cross-sectional view of a conventional disk molding mold device, FIG. 6 is a schematic plan view showing the molding surface side of the movable mold of the mold device, and FIG. FIG. 8 is a cross-sectional view of a main part of a disk formed using a disk substrate molded by the conventional disk molding device, and FIG. 8 is a schematic cross-sectional view showing a state in which a hub is welded to the disk. 34... Fixed side mold 36... Movable side mold 38... Stamper holder 39... Center member 41... Ejector sleeve 46... Extension part 47, 48, 49... Nest Line 51...Disk board

Claims (1)

[Scope of Claims] A disk molding mold device comprising a fixed mold provided with a nozzle for injection of synthetic resin and a movable mold provided with a stamper, the movable mold comprising: At least a stamper holder that supports the stamper on a stamper support plate; a center member that is concentric with the stamper holder and provided on the inner peripheral side thereof and that regulates the mounting position of the stamper holder, and a center member that is provided concentrically with the center member. and an ejector sleeve for ejecting a molded product that can move forward and backward with respect to the center member, and a part of the stamper holder extends to the ejector sleeve, and the end of the center member on the stamper side is connected to the stamper holder. A mold device for molding discs.