JPH0116649B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Technical Field of the Invention The present invention relates to audio discs and video discs used to reproduce sounds, images, etc. The present invention relates to a method of manufacturing a disk that can be used.

(B) Background of the Invention In recent years, optical disks and magnetic disks have been the mainstream of disks like the one described above, and as is well known, these disks have light reflecting grooves (pits) carved on the surface of the disk, or It is provided to be reproducible based on the application of required magnetism, and will be explained below using an optical disk as an example.

As is well known, the raw materials used for conventional optical disks are aluminum or glass fiber materials, which have excellent deformation resistance and durability.

However, the surface of an optical disk requires high flatness precision in order to form highly sensitive light reflection grooves, and for this reason, currently, in the disk manufacturing process,
Special polishing of the disk surface is required, which increases the cost and makes the disk expensive.

(c) Purpose of the Invention Therefore, the object of the present invention is to provide a method for manufacturing a disk that can be manufactured efficiently without requiring special polishing.

(D) Summary of the Invention This invention provides an injection nozzle having an outer diameter equal to the disk diameter on the front end surface, and a fixed mold that holds the injection nozzle freely in rotation. A concave portion is formed by retracting the front end face of the injection nozzle, and the end face of a rotary body having an outer diameter of the disk diameter is opposed to the front end face of the concave portion, and when the opposed rotary body is rotationally driven, the injection nozzle The present invention is characterized in that the disc manufacturing method involves injecting heat-softened resin into the recess.

(E) Effects of the Invention According to the present invention, a disk can be easily molded by injecting and solidifying a heat-softened resin raw material into a recess formed at the disk diameter and disk thickness.

In addition, during this molding, the resin injected into the recess by rotationally driving the rotating body is supplied while being uniformly distributed in the circumferential direction as the rotating body rotates, and moreover, the resin is supplied to the opposite side via this resin. Since the injection nozzle is similarly rotated in conjunction with the injection nozzle, both end surfaces of the resin material are efficiently injected from the outer circumferential surface side to the central portion side of the recessed portion based on the centrifugal force effect due to rotational contact.

In particular, since the rotating body has a disk diameter and pressurizes only the end face of the resin material, the resin material is prevented from warping due to heat shrinkage, and the surface roughness of the resin material is extremely small. A manufactured disk is formed.

Therefore, since the obtained resin disk can be molded without requiring special polishing, the number of manufacturing steps can be reduced, and a disk that is both cost effective and effective can be provided.

(F) Embodiment of the Invention An embodiment of the invention will be described in detail below based on the drawings.

The drawings show an example of manufacturing an optical disk, and in FIGS. 1 and 2, an optical disk manufacturing apparatus 1 is composed of a fixed mold 2 and a movable mold 3.

A mold for forming an optical disk is formed between the mutually opposing surfaces of these molds 2 and 3.

The fixed mold 2 described above includes a fixed casing 5 of a cylindrical body fixedly installed by a support member 4, and an injection nozzle 6 for injecting the resin raw material of the disk at the axis of the fixed casing 5, which is freely rotatably supported. The injection nozzle 6 has a stepped shaft body having a large-diameter shaft portion 7 at the front end having an outer diameter that is the same as the disk diameter, and a small-diameter shaft portion 8 at the rear end side. An injection hole 9 for injecting the resin raw material of the disk toward the front end face side is bored in the central axis direction of this shaft body, and the rear end side of this injection hole 9 is connected to a resin raw material supplying device (not shown). The front end surface of the large-diameter shaft portion 7, which corresponds to the tip opening of the injection hole 9, is formed as a flat end surface on one side for forming the disk surface. The large-diameter shaft portion 7 projects horizontally forward and is rotatably supported in the center hole 10 of the fixed casing 5 via bearings 11 .

The above-mentioned fixed casing 5 is formed into a large-diameter disk, and a center hole 10 for pivotally supporting the large-diameter shaft 7 of the above-mentioned injection nozzle 6 is opened in the center thereof, and a disk is formed in the center of the front end surface. A recess 12 corresponding to the thickness is formed by retreating the front end face of the injection nozzle, and this recess 13 is provided as a molding die portion of the disk.

The above-mentioned movable mold 3 includes a movable casing 13 facing the fixed casing, a movement device 14 for the movable casing, a rotating body 15 disposed inside the movable casing, and a drive device 16 for the rotating body. configured.

The above-mentioned movable casing 13 is driven to move forward and backward toward the fixed casing 5 by an advance/retreat device 14, and is coaxially opposed to the axis of the above-mentioned fixed casing 5 and has the same diameter. It is formed into a cylindrical body, and the above-mentioned advancing/retracting device 14 is connected to the rear end plate on the rear end side of the cylindrical body.

In the above-mentioned advancing/retracting device 14, a pair of vertically parallel hydraulic cylinders 17, 17 are fixed to a support 18 disposed on the rear end surface side of the movable casing 13, and the tip of the horizontally protruding piston rod is attached to the movable casing 13. The movable casing 13 is fixed to the rear end plate, and is moved forward and backward by driving hydraulic cylinders 17, 17.

The above-mentioned rotating body 15 is formed into a stepped shaft having a large diameter shaft part 19 and a small diameter shaft part 20 having an outer diameter equal to the disk diameter, and this large diameter shaft part 19 is connected to a bearing 21...
The small diameter shaft portion 20 is rotatably supported in a shaft support hole 22 opened at the center of the front end surface of the movable casing 13 through the movable casing 13 , and the small diameter shaft portion 20 is journalled inside the movable casing 13 and is connected to the rotating body drive device 16 . be done.

The front end surface of this rotating body 15 is formed into a flat end surface for forming the other end surface of the disk molding die.
This flat end surface faces the front end opening surface of the aforementioned recess 12 in a plane, and the contact space formed by facing each other in this way, that is, the closed recess 12 is a mold for forming the disk (recess 12). It is established as

Then, based on the forward and backward movement of the movable casing 13, the formation of a sealed molding die 12 and the opening operation thereof are performed.

The above-mentioned rotary body drive device 16 is built in the hollow interior of the movable casing 13, and drives a drive gear 25 outputted via a motor 23 and a reduction gear device 24 onto the small diameter shaft portion 20 of the rotary body 15. It is provided so as to mesh with the driven gear 26 which is fitted and fixed on the outside.
Based on the drive output of the motor 23, the rotating body 15 is driven to rotate at a constant speed.

When manufacturing a resin optical disk using the optical disk manufacturing apparatus configured as described above, first the advancing/retracting device 14 is activated to advance the movable casing 13, thereby moving the disk as shown in FIG. After forming the molding die 12, the resin 27 is heated and softened while being rotated at a low speed via the drive device 16 and injected from the injection nozzle 6, so that the resin 27 passes through the injection hole 9. is injected from the tip of the nozzle into the mold 12 of the disk, and
Since the nozzle 6 is rotated by transmitting the rotational force of the rotating body 15 through the injected resin 27,
Thereby, the resin 27 is sequentially dispersed and injected in the outward radial direction based on the centrifugal force on both sides of the rotating body 15 and the injection nozzle 6, and is uniformly injected from the outer peripheral portion of the mold 12 to the central portion. After the injection is completed, the injection operation is stopped, and after the resin 27 has solidified, the movable casing 13 is moved back as shown in FIG. By post-processing in the molding process, a disk-shaped optical disk 28 is manufactured as shown in FIG.

In the above embodiment, an optical disk was described, but the present invention can also be applied to a magnetic disk by using a resin material that can be magnetized.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a longitudinal cross-sectional view of essential parts showing the manufacturing state of an optical disk manufacturing apparatus. FIG. 2 is a longitudinal cross-sectional view of the main part of the device showing a state in which the movable casing is retracted. FIG. 3 is a perspective view showing the optical disk. 1... Optical disk manufacturing equipment, 2... Fixed mold,
3...Movable mold, 6...Injection nozzle, 12...Recess, 15...Rotating body.

Claims (1)

[Claims] 1. An injection nozzle having an outer diameter equal to the disk diameter is provided on the front end surface, and a recess corresponding to the thickness of the disk is formed in the center of the front end surface of a fixed mold that freely rotatably holds this injection nozzle. The end face of a rotary body having an outer diameter equal to the disk diameter is opposed to the front end opening face of the concave portion in a plane, and the heated and softened resin is injected into the concave portion from the injection nozzle while the opposed rotary body is being driven to rotate. A disk manufacturing method characterized by injecting.