JPH0676369A - Optical disc manufacturing method - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a method for manufacturing an optical disk having a metal hub fixed to an optical disk substrate with a photocurable resin. [Structure] A step of applying a photocurable resin 3 on an optical disk substrate 1 and then loading a metal hub 2, and the metal hub 2
The step of irradiating the optical disk substrate 1 loaded with the light from the side of the metal hub 2 to temporarily bond the metal hub 2 and the step of inverting the optical disk substrate 1 to which the metal hub 2 has been temporarily bonded and then applying the light from the side of the optical disk substrate 1 The main adhesion step of irradiating and completely curing the photocurable resin 3 is included.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for manufacturing an optical disc. More specifically, the present invention relates to a novel method for manufacturing an optical disc that is configured by integrating a resin-made optical disc substrate including a magneto-optical recording layer and a metal hub with a photocurable resin.

[0002]

2. Description of the Related Art As an optical information recording medium, various shapes such as a drum shape and a card shape have been proposed in addition to an optical disk formed in a disk shape. However, a disk-shaped so-called optical disk shape is the most advantageous because it has many advantages such as random access, easy configuration of a drive unit or write / read unit, and easy storage and handling. It is popular.

An optical disk is usually an optical disk substrate loaded with a recording layer formed of a magneto-optical recording material,
It is configured by combining a drive unit and a hub that fits when used. While a resin substrate such as polycarbonate is generally used as an optical disk substrate, a hub that requires sufficient strength and accuracy is a composite hub in which a metal plate is insert-molded with a resin such as polycarbonate, or a metal plate. Press-molded metal hubs are used.

Incidentally, unlike a magnetic recording medium, an optical disk relies on a guide groove formed in advance on a substrate as a physical format for recording information. For this reason, in the optical disc that is rotated and used, the center of rotation defined by the hub must be exactly aligned with the center of the guide groove. Therefore, in manufacturing an optical disc, a step of detecting the guide groove of the optical disc substrate and positioning the hub so as to be coaxial with the center of the detected guide groove is included. Incidentally, an adhesive double-sided tape or a photocurable resin is used for bonding the optical disk substrate and the hub, and the photocurable resin is advantageous in terms of easiness of handling and cost.

An apparatus used to detect the center of the guide groove in the step of mounting the hub on the optical disk substrate is to detect the center by reading the guide groove with a reading head while supporting and rotating the optical disk substrate from below. I do. Therefore, in the mounting process of the hub, the lower part of the optical disk substrate is shielded by the above-mentioned device, and it is not possible to irradiate the photo-curable resin used as the adhesive with light from below. On the other hand, the hub is attached to the optical disc substrate supported from below from above the optical disc substrate. Therefore, the bonded portion between the optical disk substrate and the hub is covered by the hub itself above.

Here, when a composite hub is used as the hub, since the hub itself transmits light, there is no problem in curing the photocurable resin used as the adhesive.
On the other hand, since the metal hub does not transmit light at all, when the metal hub is used, the photo-curable resin may cause defective adhesion.

[0007]

However, at the same time as the photo-curable resin is a preferable material as an adhesive,
The metal hub is also excellent in performance and cost, and in order to inexpensively popularize a high-quality optical disk, it is extremely advantageous to establish an optical disk manufacturing method using a combination of both.

Therefore, the present invention solves the above-mentioned problems of the prior art, and provides a novel optical disk manufacturing method in which a metal hub can be used as a hub and a photocurable resin can be used as an adhesive. Its purpose is.

[0009]

That is, according to the present invention,
In a manufacturing process of an optical disc including a disc-shaped or annular optical disc substrate including a magneto-optical recording layer, and a metal hub mounted on the optical disc substrate coaxially with the optical disc substrate, a metal hub mounting portion of the optical disc substrate A step of applying a photocurable resin on the optical disk, a step of temporarily placing the metal hub at a proper position on the optical disk, and then irradiating the metal hub with light to position the metal hub, and a step of temporarily attaching the metal hub. And a main bonding step of irradiating light from the optical disk substrate side to completely cure the photo-curable resin after inverting the optical disk including the metal hub. .

Further, in the optical disc manufacturing method according to the present invention, according to a preferred aspect of the present invention, the photocurable resin is applied to a flange portion of the metal hub which is in direct contact with the photocurable resin. There is provided a method for manufacturing an optical disc, which is characterized in that a through hole that allows curing light to pass therethrough is formed.

[0011]

In the method of manufacturing an optical disk according to the present invention, in the step of adhering the metal hub with the photocurable resin, a temporary adhering step of irradiating light from the metal hub side to cure the photocurable resin and a light from the substrate side are applied. Its main feature is that it includes a main adhesion step of irradiating and curing the photocurable resin.

That is, in the conventional manufacturing method, when the photocurable resin is used as the adhesive, even if the metal hub is used, the photocurable resin is cured in the same manner as when the composite hub is used. I was trying. For this reason, when a metal hub is used, there is a risk of defective curing.

On the other hand, in the method according to the present invention, the positioning of the metal hub with respect to the optical disk substrate and the complete bonding thereof are considered as different works, and in the step of positioning the metal hub, the light irradiation from the metal hub side causes Although the adhesion is incomplete, positioning is completed, and in the next step,
The photocurable resin is completely cured by reversing the optical disc substrate and irradiating light from the optical disc substrate side. By such a process, it becomes possible to manufacture a high-quality optical disk by combining the metal hub and the photocurable resin.

Further in accordance with a preferred embodiment of the present invention,
By forming the through hole in the flange portion of the metal hub used in the method for manufacturing an optical disc according to the present invention, the positioning of the metal hub by light irradiation from the metal hub side can be made more reliable.

The optical disk manufacturing method according to the present invention as described above can be performed without significantly modifying the conventional manufacturing equipment.
It can be implemented easily and reliably.

Hereinafter, the present invention will be described more specifically with reference to the drawings, but the following disclosure is merely an example of the present invention and does not limit the technical scope of the present invention.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing, step by step, an optical disc manufacturing method according to the present invention.

In the method according to the present invention, as shown in FIG. 1 (a), first, the optical disk substrate 1 is placed on the supporting member 4 supported by the rotating spindle 5, and then the head 7 is used. Then, the center of the optical disk substrate 1 is detected. Further, the photo-curable resin 3 is applied to the adhesion area of the optical disc substrate 1.

Next, as shown in FIG. 1B, the metal hub 2 is mounted from above so that the center of the detected optical disk substrate 1 coincides with the center of the detected optical disk substrate 1. At this time, the flange portion 2a of the metal hub 2 contacts the photocurable resin 3 applied on the optical disc substrate 1.

Subsequently, as shown in FIG. 1C, light is irradiated from above the optical disk substrate 1, that is, from the metal hub 2 side to cure the photocurable resin 3. At this time, the lower side of the optical disc substrate 1 is blocked by the manufacturing device for the support member 4 and the like, so that the light cannot be emitted from the optical disc substrate 1 side, and the light must be emitted from the metal hub 2 side. Therefore, in this step, the photocurable resin 3 is cured only at the edge portion of the flange portion 2a of the metal hub 2 and the periphery of a through hole described later provided in the flange portion 2a, and the photocurable resin 3 is cured in other areas. 3 was hardly cured. Therefore, the adhesive strength to the extent that the metal hub 2 can function as a hub cannot be obtained, but the strength to the extent that the position of the metal hub 2 can be maintained is obtained.

Finally, as shown in FIG. 1 (d), the optical disk substrate 1 to which the metal hub 2 is temporarily adhered as described above.
After being inverted and placed on the support base 6, light is irradiated from above, that is, from the side of the optical disk substrate 1 to completely cure the photocurable resin 3. In this way, the metal hub 2 is firmly bonded at the position determined in the previous step.

FIG. 2 is a sectional view and a plan view showing a concrete shape of the metal hub 2 which can be preferably used in the method according to the present invention as described above.

As shown in FIG. 2 (a), the metal hub 2 is
It is composed of one press-formed metal plate,
At the center, a through hole that fits into the optical disk drive is provided. Further, a flange portion 2a used when adhering to the optical disc substrate is formed on the peripheral portion thereof.

Further, the metal hub 2 is provided with a plurality of through holes 2b formed in the flange portion 2a at equal intervals. By providing such a through hole 2b, when the light is irradiated from the metal hub 2 side, the photo-curable resin is cured at least in the region of the through hole 2b and its peripheral portion, so that sufficient positioning is ensured. The hub is fixed with sufficient strength.

The shape of the metal hub is not limited to this, and the shape, number, etc. of the through holes 2b to be formed can be appropriately selected. Further, it is not necessarily a hole, and a slit or the like cut in the metal hub may be used. Furthermore,
A metal hub may be manufactured using punching metal or the like as long as the function and strength of the metal hub as a hub are not impaired.

[0026]

As described in detail above, according to the optical disk manufacturing method of the present invention, a metal hub capable of realizing a high-strength and high-precision hub at a low cost, and an optical disk that is easy to handle and inexpensive. By combining with a curable resin, it becomes possible to reliably manufacture an inexpensive and high-quality optical disc.
Further, this manufacturing method is also advantageous in that it can be easily implemented without major modification of conventional manufacturing equipment.

[Brief description of drawings]

FIG. 1 is a diagram showing each step of a method for manufacturing an optical disc according to the present invention.

FIG. 2 is a diagram showing a configuration example of a metal hub that can be preferably used in the optical disc manufacturing method according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical disk substrate, 2 ... Hub (metal hub), 2a ... Flange part, 2b ... Through hole, 3 ... Photocurable resin, 4 ... Support member, 5 ... Spindle, 6 ... Support base, 7 ... Head, 8 ... Light source

Claims (2)

[Claims] 1. An optical disk substrate comprising: a disk-shaped or annular optical disk substrate including a magneto-optical recording layer; and a metal hub coaxially attached to the optical disk substrate and bonded to the optical disk substrate. Step of applying a photo-curable resin to the metal hub mounting portion, and a temporary bonding step of positioning the metal hub by irradiating light from the metal hub side after mounting the metal hub at an appropriate position on the optical disk And an actual bonding step of inverting the optical disk including the temporarily bonded metal hub and then irradiating light from the optical disk substrate side to completely cure the photocurable resin. Production method. 2. The manufacturing method according to claim 1, wherein
A method of manufacturing an optical disc, wherein a through hole for passing light for curing the photocurable resin is formed in a flange portion that directly contacts the photocurable resin on the metal hub side.