JPH11339320A - Optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the amount of original material and the weight of an optical recording medium. SOLUTION: The medium consists of a circular plate shaped single plate disk 2 and a hub member 10 which is mounted at the central section of the disk. A disk center hole 4 is provided in the central section of the disk 2. The member 10 has a hub main body member 11 made of synthetic resin material and a magnetic member 12 mounted on the member 11. The member 11 has a hub fixed section 11a, which is arranged in a ring shape at a hub main body member peripheral section, and a hub fitting section 11b having a protrusion shape in the thickness direction of the disk in the inside region than the section 11a. The member 10 is adhered to a first surface 2a of the disk 2 at the section 11a. Moreover, the member 10 is fitted to the hole 4 of the disk 2 at the section 11b. The outer peripheral of the section 11a is located on the inner side of the outermost side of a clamp region 6 which is beforehand set for clamping a single plate disk.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording medium on which information is recorded and reproduced by using light, and more particularly to an ISO standard 10
The present invention relates to an improvement in a hub member in an optical recording medium (optical disk) having a structure in which a hub member is attached to the center of a single disk, such as a magneto-optical recording medium described in No. 090 or the like.

[0002]

2. Description of the Related Art Commercially available magneto-optical disks (MO disks)
Then, when clamping the optical recording medium to the rotating shaft of the drive, a hub having a magnetic member is provided on the optical recording medium (optical disk), and the magnetic force is generated by a permanent magnet embedded in a turntable fixed to the rotating shaft of the drive. A method of clamping an optical disk has been adopted.

In an optical disk, a light incident surface (second surface) opposite to a surface on which an information recording section is provided (first surface) is usually placed (clamped) on a turntable.
The hub member is provided in a convex shape at the center of the light incident surface (second surface) of the optical disk, and its dimensions are in accordance with ISO 1009
It is stipulated in No. 0 etc. The name of the standard document of ISO / IEC standard 10090 is “90mm optical disk ca”.
rtridges, rewritableand read only, for data interc
The outer diameter (actual size) of the specified single-plate disc is 86 mm, and the nominal size is 3.5 (inch).

[0004] This 3.5-type magneto-optical disk and the like include:
Although used as a single-plate disk having an information recording portion provided on one side of a 2 mm-thick polycarbonate substrate, the hub member is composed of a fixed portion and a fitting portion, and has a surface on which the information recording portion is provided (first surface). Surface) with a fixed part for practical use. There are two methods for bonding the hub member and the single-plate disk, a method using a photocurable adhesive resin and a method using ultrasonic fusion. In particular, the method using ultrasonic fusion is superior to the low production cost and high production speed. The outer diameter of the fixing portion of the hub member is, for example, Japanese Patent No. 258758.
As described in No. 0, in the radial direction, it is larger than the outermost or outer diameter of the clamping area of the disk.

[0005] The clamp area of the disk refers to a portion of the optical disk that can come into contact with the turntable when the light incident surface (first surface) of the optical disk is placed on the turntable. 3.5
Area of the optical disk is of the ISO standard 100
The clamp area is defined in No. 90 and has a diameter of 16 mm to 21 mm.

[0006]

SUMMARY OF THE INVENTION The magneto-optical recording medium is required to reduce the manufacturing cost in order to further spread the medium in the future. In addition, high-speed rotation performance of the disk for high-speed reading, reduction in the size and weight of the device, and reduction in the weight of the optical disk are required in order to reduce power consumption.

Further, when the hub is bonded by the ultrasonic fusion method, the fixed portion of the single-plate disk and the hub member is bonded only at the rim portion, and the rim portion and the outer diameter of the hub fixed portion are bonded. Although the gap is not bonded, there is a gap, but if this gap is intentionally pushed open, the hub can be easily separated from the optical disc. From the viewpoint of preventing mischief, it is desirable that the gap be as narrow as possible.

An object of the present invention is to solve the above-mentioned problems and to reduce raw materials for an optical recording medium and thereby reduce the weight.

[0009]

The optical recording medium of the present invention comprises:
A disk-shaped veneer disk, and a hub member attached to the center of the veneer disk. One surface of the veneer disk is defined as a first surface and the other surface is defined as a second surface. An information recording unit is provided on the first surface, and the information recording unit is irradiated with light from the second surface to record and / or read information. A hub member having a disk center hole, the hub member having a hub body member made of a synthetic resin material, and a magnetic member attached to the hub body member; and the hub body member being annularly arranged on the outer periphery of the hub body member A fixing portion, and a hub fitting portion having a shape protruding in a thickness direction of the single-plate disc in a region inside the hub fixing portion, wherein the hub member is bonded to the first surface of the single-plate disc at the hub fixing portion. And the hub member is a hub fitting portion When the optical recording medium is attached to a device that records and / or reads information by fitting into the center hole of the single-disc disk, the single-disc disc is attached by clamping on the second surface side. The outer peripheral edge of the hub fixing portion is located inside the outermost portion of a clamp area preset for single-plate disc clamping.

Here, the hub fixing portion is provided with a rim portion for ultrasonically welding the hub member to the single-plate disk, and the rim portion is located inside the outermost portion of the clamp area, which is a point of productivity. Is preferred. The optical recording medium is preferably a 3.5-type magneto-optical recording medium from the viewpoint of clampability.

[0011]

FIG. 1 is a sectional view showing the structure of an optical recording medium (optical disk) according to an embodiment of the present invention. The optical recording medium includes a single-plate disk 2 and a hub member 10. There is a first surface 2a on which the information recording unit 3 is provided and a light incident surface (second surface) 2b on which the laser light 5 is incident.

The hub member 10 has a hub body member 11 made of a synthetic resin material and a magnetic member 12 provided integrally with the hub body member. The hub body member 11 has a predetermined width in the radial direction. Hub fixing portion 11a. It is bonded to the first surface 2a of the single-plate disk at the hub fixing portion. In the example of FIG. 1, the bonding is performed by melting and fixing the rim portion 13 to the single-plate disk by ultrasonic fusion.

The hub body member 11 has a hub fitting portion 11b in a region inside the hub fixing portion 11a, the hub fitting portion 11b protruding in the thickness direction of the single disk 2. The magnetic member 12 is fixed to the tip of the hub fitting portion 11b. The hub fitting portion 11b is fitted in the disc center hole 4.
When the center hole 4 of the disk has a diameter of 15.0 mm, the outer diameter of the hub fitting portion to be fitted into the center hole is controlled within a range of 14.85 mm to 14.95 mm in diameter, and is manufactured with normal machining dimensional accuracy. You.

Reference numeral 6 in the drawing denotes a clamp area. According to ISO 10090, a range from 16 mm to 21 mm in diameter is defined as the clamp area.
In the present invention, the outer peripheral edge, that is, the outer diameter of the hub fixing portion 11a is the outermost of the clamp area, that is, the outer diameter of the clamp area (IS
The diameter is smaller than 21 mm in O standard 10090), and the inner diameter of the clamp area (diameter 1 in ISO standard 10090).
6 mm).

In particular, in the case of the ultrasonic fusion method, the rim 13
Must be located between the inner and outer diameters of the clamp area 6. The diameter of the rim is usually 18.0mm to 20.0mm
mm. When the rim has a donut-shaped width, the inner diameter of the width is larger than the inner diameter of the clamp area, and the outer diameter of the width is smaller than the outer diameter of the clamp area.

By adopting the above configuration, waste which has conventionally been unnecessarily adhered to the outside of the clamp area has been improved, and the manufacturing cost and weight of the optical disk have been reduced. In addition, sufficient reliability is ensured by the presence of the bonding portion between the clamp regions. Particularly, in the ultrasonic welding, the unnecessary portion outside the rim portion is reduced, so that the danger of peeling of the hub can be reduced even when an unexpected external force is applied.

[0017]

As described above, according to the optical recording medium of the present invention, by using a hub which is lighter than the conventional hub, it is possible to reduce the manufacturing cost of the optical disk and reduce the weight of the optical disk. And it was able to contribute to high-speed rotation and reduction of power consumption.

[Brief description of the drawings]

FIG. 1 is a cross section of an optical recording medium.

[Explanation of symbols]

 Reference Signs List 2 single disk 2a first surface 2b second surface 3 information recording portion 4 disk center hole 5 laser beam 6 clamp region 10 hub member 11 hub body member 11a hub fixing portion 11b hub fitting portion 12 magnetic member 13 rim portion

Claims (3)

[Claims] 1. A disk-shaped veneer disk and a hub member attached to the center of the veneer disk, wherein one surface of the veneer disk is a first surface and the other surface is a second surface. An optical recording medium for recording and / or reading information by irradiating an information recording portion on a first surface of a single-disc disk and irradiating the information recording portion with light from a second surface side; Has a disc center hole in the center of
The hub member has a hub body member made of a synthetic resin material and a magnetic member attached to the hub body member. Further, the hub body member has a hub fixing portion annularly arranged on the outer periphery of the hub body member, and a hub fixing portion. A hub fitting portion having a shape protruding in the thickness direction of the single-plate disc in a more inner region,
The hub member is bonded to the first surface of the single disk at the hub fixing portion, and the hub member is fitted into the disk center hole of the single disk at the hub fitting portion to record and / or read information. When the optical recording medium is mounted, it is mounted by clamping on the second surface side of the single-plate disk, and the outer peripheral edge of the hub fixing portion is positioned from the outermost side of the clamp area preset for the single-plate disk clamp. An optical recording medium characterized by being inside. 2. The hub fixing portion is provided with a rim portion for ultrasonically fusing the hub member to the single-plate disk, and the rim portion is located inside a maximum range of the clamp area. 2. The optical recording medium according to 1. 3. The optical recording medium according to claim 1, wherein the optical recording medium is a 3.5-type magneto-optical recording medium.