JP2003077178A - Optical disk, its manufacturing method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce costs for a bonded optical disk of one side using type, and to simultaneously contribute to resource conservation. SOLUTION: In the optical disk where first and second disks are bonded, and a recording pit or a recording layer is provided only in the first disk, the second disk is made of only a recycled resin martial of the kind similar to the disk substrate material of the first disk.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc of a bonded type and a single-sided type, and a technique relating to the optical disc.

[0002]

2. Description of the Related Art Bonding type optical disks in which a first disk having a thickness of about 0.6 mm and a second disk having a thickness of about 0.6 mm are bonded to each other by an adhesive layer are first and second disks. Double-sided type with recording pits or recording layers on both sides, and the first disc (LAYER0
There is a single sided type in which a recording pit or recording layer is provided only on the side). And, conventionally, the second disc (LA
Even in a single-sided type optical disc in which recording pits or recording layers are not formed on the YER1 side), the second disc is currently molded using a virgin resin material.

[0003]

As described above, in the conventional single-sided-use bonded optical disk, the virgin resin material is also used for the second disk having no recording pit or recording layer. Because
That is, since the virgin resin material is also used for the second disk which is not required to have optical characteristics, there is a problem that the material cost is high. Furthermore, since the sprue part generated during molding, the defectively formed disc substrate and the disc substrate at the time of test shots were discarded, a disposal cost for this is also required, and it is also desirable from the viewpoint of resource saving. There wasn't.

The present invention has been made in view of the above points,
The purpose of this is to reduce the cost of a single-sided-use bonded optical disc and also contribute to resource saving.

[0005]

In order to achieve the above-mentioned object, the present invention is an optical disc in which a first disc and a second disc are bonded to each other and recording pits or recording layers are provided only in the first disc. In, the second disk,
It is formed only by the same kind of recycled resin material as the disk substrate material of the first disk.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view of a main part along the radial direction of an optical disc according to an embodiment of the present invention. In FIG. 1, 1 is a first disc having a thickness of about 0.6 mm, 2 is a second disc having a thickness of about 0.6 mm, and both 1 and 2 are bonded together by an adhesive layer 3 to have a total thickness of about 1.2 mm. Of the optical disc.

Reference numeral 11 denotes a disk substrate of the first disk 1, which is produced by injection molding using pellets of virgin polycarbonate, and a groove 12 is formed on one surface thereof, and as a result of the formation of the groove 12, The land 13 is formed. A heat resistant protective film 14, a phase change type recording film 15, a heat resistant protective film 16, a reflective film 17, and an overcoat 18 are sequentially laminated on the surface of the first disk 1 on which the grooves 12 and lands 13 of the disk substrate 11 are formed. The surface of the overcoat 18 is smoothed.

On the other hand, the entire second disc 2 is a disc substrate, and the second disc 2 has a sprue portion produced when the disc substrate is molded using polycarbonate, a disc substrate having a defective molding, and The scrap portion or molded product made of polycarbonate, which has been conventionally discarded, such as a disk substrate at the time of test shot is crushed by a crusher as 100% of the raw material and manufactured by injection molding. That is, the second disk 2
Are made of only the same kind of recycled resin material as the material of the disk substrate 11 of the first disk 1.

In the single-sided bonding type optical disc of this embodiment having such a configuration, the raw material of the second disc whose optical characteristics are not considered is 100% recycled resin material. It is possible to reduce the manufacturing cost of the disk of, and since the scrap parts and molded products that were previously discarded are reused,
It can also contribute to resource saving.

In the above-mentioned optical disc, the first disc is capable of recording / reproducing.
It goes without saying that the present invention can be applied even if the first disc is a read-only disc in which information is recorded in pits.

FIG. 2 is a block diagram of a system for manufacturing the second disk. This system mainly comprises a crusher 21 for crushing a molded resin and an injection molding machine 22 with an automatic raw material supply device. It is configured.

As described above, the crusher 21 is for crushing scrap parts and molded products (defective disk substrates and disk substrates by test shots) made of polycarbonate which have been conventionally discarded. The scrap parts and molded products made of polycarbonate collected from our company or other companies are put in and crushed. The size to be crushed is preferably the same as that of pellets of virgin polycarbonate, and by doing so, it is possible to secure biteability to the screw. The recycled resin material crushed by the crusher 21 is carried to a place where the injection molding machine 22 is installed by an appropriate means, and is introduced into the raw material automatic supply device 23 attached to the injection molding machine 22.

The injection molding machine shown in FIG. 2 is an in-line screw type electric injection molding machine. In FIG. 2, reference numeral 24 is a fixed die plate on which the fixed side die 25 is mounted, 26 is a holding plate on which a die opening / closing servomotor 27 is mounted, and 28 is the fixed die plate 24 and the holding plate 2.
6 is a tie bar installed between 6 and 29 is a tie bar 28
Is movable through the fixed die plate 24, and the movable die 30 is mounted on the movable die plate; 31 is a ball screw mechanism for converting the rotation of the die opening / closing servomotor 27 into a linear movement; , Ball screw mechanism 3
It is a toggle link mechanism that moves the movable die plate 29 forward or backward by receiving the axial driving force of 1.

Further, 33 is a heating cylinder in which a screw 34 is arranged so as to be able to rotate and move forward and backward, 35 is attached to the tip of the heating cylinder 33, and a resin injection port of the fixed side mold 25 is provided. Nozzle pressed against, 36 is a cylinder holding block holding the base end side of the heating cylinder 33, 37 is a cylinder holding block 36
, 38 is a holding plate on which an injection servomotor 39 is mounted, 40 is a guide bar installed between the cylinder holding block 36 and the holding plate 38, and 41 is inserted into the guide bar 40 to move forward and backward. A moving block 42 that is capable of advancing and that holds the rear end of the screw 34 so as to be rotatable is mounted on the moving block 41 and drives the screw 34 to rotate via a transmission mechanism (not shown). The metering servomotor 43 is a ball screw mechanism that converts the rotation of the injection servomotor 39 into a linear motion and transmits the linear motion to the moving block 41. The lower part of the hopper 37 and the heating cylinder 3
A resin dropping hole is provided between the rear portion of the heating cylinder 36 and the rear portion of the heating cylinder 36, and the raw material resin is supplied from the hopper 37 into the rear portion of the heating cylinder 36.

In the structure shown in FIG. 2, the screw 34 is rotationally driven in a predetermined direction by the servomotor 42 for metering during the metering process, whereby the raw material resin is kneaded and plasticized, and the screw 34 is fed by the screw 34 to feed the screw. It is sent to the tip side of 34. Then, as the molten resin accumulates on the tip side of the screw 34, the screw 34 is controlled to move backward together with the moving block 41 while the back pressure is controlled by the injection servomotor 39 and the ball screw mechanism 43, and the screw 34 is moved to the tip side of the screw 34. When the molten resin corresponding to one shot is accumulated, the rotation of the measuring servomotor 42 is stopped. Further, during the injection stroke, the injection servomotor 39 and the ball screw mechanism 4
The screw 34 is rapidly moved forward together with the moving block 41 by the moving block 41, whereby the molten resin accumulated on the tip side of the screw 34 is discharged from the nozzle 35 by the fixed mold 25 and the movable mold in the mold closed state. It is designed to be injected and filled in a cavity formed by 30 and 30.

In the structure shown in FIG. 2, the movable die plate 29 is driven forward by the die opening / closing servomotor 27, the ball screw mechanism 31, and the toggle link mechanism 32.
When the movable side mold 30 reaches the mold closing completion position, a cavity is formed between the movable side mold 30 and the fixed side 25. At this mold closing completion position, the planes of both molds 25, 30 (see FIG. The vertical surfaces of the inside) are separated from each other by a predetermined amount, and while the molten resin injected and filled in the cavity does not solidify, the movable mold 31 is further advanced to compress the resin. Is added (note that
Even when the compression stroke is completed, the vertical surfaces of the two molds 25 and 30 in the figure are separated from each other by a predetermined amount. By adopting such a configuration and control method, it is possible to improve the plate thickness accuracy of the second disk 2. When the compression stroke is completed, the resin inside the cavity cools
In the solidified state, the movable die plate 29 is driven backward by the mold opening / closing servomotor 27, the ball screw mechanism 31, and the toggle link mechanism 32, whereby the mold opening is performed. On the way of the mold opening or after the completion of the mold opening, A molded product is released from the mold by an eject mechanism (not shown).

[0018]

As described above, according to the present invention, it is possible to reduce the cost of a single-sided-use bonded optical disk and also contribute to resource saving.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of essential parts along a radial direction of an optical disc according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a system for manufacturing a second disc in the optical disc according to the embodiment of the present invention.

[Explanation of symbols]

1st disc 2 second disk 3 adhesive layer 11 Disc substrate of the first disc 12 grooves 13 lands 14, 16 Heat-resistant protective film 15 Recording film 17 Reflective film 18 overcoat

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Claims (3)

[Claims] 1. An optical disc in which a first disc and a second disc are bonded to each other, and recording pits or recording layers are provided only on the first disc, wherein the second disc is the first disc. An optical disk, which is formed only by using the same kind of recycled resin material as the disk substrate material of the disk. 2. The method of manufacturing the second disc of the optical disc according to claim 1, wherein a step of pulverizing a reproducing resin material of the same type as the disc substrate material of the first disc, After the kneading, plasticizing, and weighing of the recycled resin material, the resin is injected, filled into a mold, and compressed to mold the second disk, and a method for manufacturing an optical disk. 3. The apparatus for manufacturing the second disc of the optical disc according to claim 1, comprising a crusher for crushing a regenerating resin material of the same kind as the disc substrate material of the first disc, An injection molding machine for molding the second disk by kneading, plasticizing and measuring the crushed resin material for reinjection, injecting it into a mold, filling it, and compressing the second disk. Manufacturing equipment.