JP3144005B2 - Optical disk and disk drive device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk used as a recording medium for information signals, and a disk drive device which mounts and rotates the optical disk.

[0002]

2. Description of the Related Art Conventionally, optical disks for recording and reproducing information signals by irradiating a laser beam include magneto-optical disks, various write-once optical disks, rewritable optical disks,
Various types such as digital audio disks and optical video disks have been put to practical use.

[0003] In a disk drive device that uses this type of optical disk as a recording medium and writes / reads information signals to / from the optical disk, further reduction in size and thickness is required.

Therefore, in order to meet such a demand, a disk-shaped chucking hub made of a metal material is attached to the optical disk, and this is magnetically attracted by a magnet built in the disk table so that the optical disk is chucked to the disk table. Configuration is adopted.

According to this structure, a complicated chucking mechanism conventionally provided on the lid of the disk drive can be omitted, so that the disk drive can be made much thinner and the number of parts can be greatly reduced. Can be reduced.

[0006]

In an optical disk having a chucking hub mounted thereon as described above, the magnetic disk is magnetically attracted by a magnet built in a disk table, and the disk is inserted into a center hole provided in a substantially central portion of the disk. Centering is performed so that the center of the disk table coincides with the center of rotation of the disk by fitting the tapered portion of the table. The disk table rotates while the optical disk is centered, and the optical disk is irradiated with a laser beam emitted from the optical pickup device to record / reproduce an information signal.

Although the above-mentioned optical disk is chucked to the disk table by the magnet in a state where the tapered portion of the disk table is fitted in the center hole, recording / reproduction gradually deteriorates as the rotation speed of the disk increases. . This is because the centering accuracy is not sufficient. For this reason, there is no problem in a low-performance disk drive device in which recording / reproduction is performed at a somewhat low rotation speed, but good recording / reproduction cannot be performed in a high-performance disk drive device in which recording / reproduction is performed at a high rotation speed. .

Accordingly, the present invention has been proposed in view of the above technical problems, and is intended to provide a highly reliable optical disk capable of performing good recording / reproducing with respect to drive devices of different models. It is an object to provide a disk drive device using this recording medium.

[0009]

An optical disk according to the present invention proposed to achieve the above object has a disk body provided with a center hole, and the disk having at least a part inserted in the center hole. A chucking member attached to the main body. The chucking member has a centering hole into which a centering pin provided on the disk table is inserted, and a centering means provided on the disk table between an inner peripheral surface of the center hole and a portion opposed to the inner peripheral surface. The disc is attached to the disc main body while maintaining a sufficient gap for fitting.

Further, the disk drive device according to the present invention has a centering means which fits into a center hole formed in a disk body of an optical disk, and a chuck which is inserted and attached at least partially into the center hole of the disk body. A centering pin fitted in a centering hole provided in the king member; and a disk table for rotating an optical disk mounted by being centered by one of the centering means and the centering pin.

In the optical disk according to the present invention, the centering means of the disk table fits into the gap provided between the center hole provided in the disk main body and the chucking member in a disk drive device having a low rotation speed. Centering is achieved. On the other hand, for a disk drive device having a high rotation speed, the centering pin of the disk table is engaged with the centering hole provided in the chucking member, thereby centering the optical disk. The optical disk according to the present invention can be used for both types of disk drive devices having a low rotation speed and a high rotation speed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below in detail with reference to the drawings. As shown in FIG. 1, the optical disc 1 of the present embodiment includes, for example, a magneto-optical disc, various write-once optical discs, a rewritable optical disc,
It has a recording layer on at least one surface, such as a digital audio disk and an optical video disk. In these optical disks 1, information signals are written to the recording layer by optical means or magneto-optical means, and the written information signals are read.

For example, in a magneto-optical disk, a recording layer including a perpendicular magnetization film having a magneto-optical effect is formed on a disk substrate constituting a disk body made of a transparent resin molded body or glass, and a recording layer is further formed thereon. And a protective film is laminated so as to cover. The recording layer is a layer on which information signals can be optically recorded / reproduced.
A dielectric base film made of 3N4, etc., a perpendicular magnetization film made of TbFeCo alloy, etc., an upper dielectric film made of Si3 N4, etc., and a metal reflection film made of Al etc. are sequentially laminated by a vacuum thin film forming technique such as sputtering. Is done.

On the other hand, an optical disk such as a CD is provided with a recording layer and a protection layer formed on a UV-curable resin layer having grooves and pits formed on a disk substrate made of a resin molded body made of polycarbonate or the like formed by injection molding. The film layers are sequentially laminated. Such a disk substrate is usually formed by a so-called 2P method because of its excellent mass productivity and economic efficiency.

Since these optical discs 1 are generally formed by an injection molding method in which a resin is poured into a mold, the optical disc 1 has a circular center hole 1a at a substantially central portion thereof. The center hole 1a is located between the center of the recording track and the center hole 1a.
These centers are formed so as to substantially coincide with each other, but usually these centers may be slightly shifted depending on the temperature during molding.

As shown in FIG. 2, a chucking member for chucking the optical disk 1 on a disk table of a disk drive device is provided at a position corresponding to the center hole 1a of the optical disk 1. The chucking member used here includes a chucking hub 2 made of a metal material and a hub attachment member 3 for attaching the chucking hub 2 to the optical disc 1.

The chucking hub 2 is magnetically attracted by a magnet 5 built in the disk table 4,
This is for chucking the optical disk 1 on the disk table 4. The chucking hub 2 is formed as a cylindrical body having one open side by, for example, pressing a metal plate, and a centering hole 7 is formed in the bottom 2 a so as to face a centering pin 6 provided on the disk table 4. Have been. This centering hole 7
Is provided as a small-diameter circular hole substantially at the center of the bottom 2 a of the chucking hub 2, and has a size slightly larger than the outer diameter of the centering pin 6.

On the other hand, the hub mounting member 3 is for mounting the chucking hub 2 to the optical disk 1, and has a cylindrical hub mounting portion 8 for directly holding the chucking hub 2 and one of the hub mounting portions 8. And an annular flange portion 9 provided on the periphery of the opening, and these are integrally formed. The hub mounting portion 8 is formed as a cylindrical body having an outer dimension smaller than the inner diameter of the center hole 1a of the optical disc 1. This hub mounting part 8
The flange 9 is fixed to the outer peripheral edge of the center hole 1a of the optical disc 1 with an adhesive or the like, so that the center hole 1
a. At this time, a slight gap is provided between the hub mounting portion 8 inserted into the center hole 1a and the inner peripheral surface of the center hole 1a. The tip of the hub mounting portion 8 inserted into the center hole 1a is slightly protruded from the surface of the optical disc 1 opposite to the surface on which the flange portion 9 is mounted.

Hub mounting portion 8 mounted as described above
The chucking hub 2 is held at the periphery of the opening at the other end of the chucking hub. That is, the chucking hub 2 is attached to the inner peripheral wall of the opening edge on the other end side of the hub mounting portion 8.
The outer peripheral wall 2b, which rises from the outer peripheral edge of the bottom 2a, is attached to the hub mounting portion 8 by contacting and adhesively fixing it.

The chucking member is an optical disk 1
To the center of the recording track and the chucking hub 2
Is mounted so that the center of the centering hole 7 drilled in the hole coincides with the center. In addition, the chucking member may be formed by integrally forming the chucking hub 2 and the hub mounting portion 8 from a metal plate by pressing.

The optical disk 1 configured as described above is suitable for a high-performance disk drive device that records and reproduces an information signal at a high rotation speed and a high speed seek.
As shown in FIG. 2, centering is performed by a centering hole 7 provided in the chucking hub 2. That is, the optical disk 1 is magnetically attracted to the disk table 4 by an annular magnet 5 built in the disk table 4 of the disk drive device, and a centering pin 6 protruding from a substantially central portion of the disk table 4 has a centering hole 7. And the centering is performed.

As described above, since the centering hole 7 of the chucking hub 2 is engaged with the centering pin 6 provided on the disk table 4, the center of the disk table 4 and the rotation center of the optical disk 1 coincide with high accuracy. . Therefore, even if the optical disc 1 is rotated at a high rotation speed, recording and reproduction can be performed well. In a high-performance disk drive device, the disk table 4 has a disk support surface 10 for supporting the disk surface of the optical disk 1.
Is provided, the flatness of the optical disk 1 is ensured, the surface runout during rotation can be reduced, and better recording / reproduction can be performed.

On the other hand, for a low-performance disk drive device that performs recording / recording / reproduction at a low rotation speed and a low speed seek, the centering is performed by the center hole 1 of the optical disk 1 as shown in FIG. That is, FIG.
An optical disk 1 is magnetically attracted to the disk table 4 by a magnet 5 built in the disk table 4 of the disk drive device shown in FIG. 1 and an annular centering portion 11 having a substantially trapezoidal cross section as a centering means provided on the disk table 4. Enters the gap provided between the center hole 1a of the optical disc 1 and the hub mounting portion 8 and contacts the peripheral edge of the opening of the center hole 1a to perform centering.

The centering portion 11 has a center hole 1a.
The surface 11a in contact with the peripheral edge of the opening is a tapered surface, and the surface 11b on the opposite side is substantially perpendicular to the disk surface, and is formed so as not to contact the hub mounting portion 8. In this case, it is desirable that the centering portion 11 is formed of a flexible material such as plastic so that the optical disk 1 can be easily centered on the disk table 4. Similarly, also in this disk drive device, the disk table 4 is provided with the disk support surface 10 for supporting the optical disk 1, so that the optical disk 1 is prevented from oscillating during rotation.

In the optical disc 1 described above, the inner diameter of the centering hole 7 provided in the chucking hub 2 is substantially the same as the outer diameter of the centering pin 6. Even in the case of a large so-called fool hole, recording / reproducing can be performed satisfactorily even with respect to a disk drive device with a high degree of accuracy.

That is, as shown in FIG. 4, the disc table 4 has a gap provided between the center hole 1a of the optical disc 1 magnetically attracted by the magnet 5 built in the disc table 4 and the hub mounting portion 8. The centering is performed by allowing the provided flexible annular centering portion 12 made of a plastic material or the like to enter and bringing the centering portion 12 into contact with the inner peripheral edge of the center hole 1a. In this way, even if the centering hole 7 is a stupid hole, centering is achieved by the center hole 1a provided on the disk substrate side. The centering unit 12
Is made to slide on the magnet 5, the centering of the optical disc 1 can be performed with high accuracy.

The present invention is also applicable to disks of the same format and the same shape. In particular, in this case, it is possible to cope with disk drive devices having different performances using almost the same production equipment.

[0027]

As is apparent from the above description, the present invention provides a low-performance disk drive for recording / reproducing at a low rotational speed and a high-performance disk drive for recording / reproducing at a high rotational speed. An optical disk that can be used for both can be configured, and a disk drive device that can use optical disks having different specifications with compatibility can be provided.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an optical disc to which the present invention is applied.

FIG. 2 is an enlarged sectional view of a main part showing a state where an optical disk to which the present invention is applied is mounted on a high-performance drive device.

FIG. 3 is an enlarged sectional view of a main part showing a state where an optical disk to which the present invention is applied is mounted on a low-performance drive device.

FIG. 4 is an enlarged sectional view of a main part showing a state in which an optical disk having a centering hole formed in a chucking hub as a fool hole is mounted on a drive device.

[Explanation of symbols]

Reference Signs List 1 optical disk, 1a center hole, 2 chucking hub, 3 hub mounting member, 4 disk table, 5 magnet, 6 centering pin, 7
Centering hole, 8 Hub mounting part, 11, 12
Centering part

Continuation of the front page (56) References JP-A-64-50289 (JP, A) JP-A-1-1655081 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 23 / 00 601

Claims (2)

(57) [Claims] 1. A disk body having a center hole, and a chucking member attached to the disk body having at least a part inserted in the center hole, wherein the chucking member is provided on a disk table. It has a centering hole into which the provided centering pin is inserted, and maintains a gap between the inner peripheral surface of the center hole and a portion opposed to the inner peripheral surface for fitting the centering means provided on the disk table. An optical disk, wherein the optical disk is mounted on the disk body. 2. A centering means which fits in a center hole formed in a disk body of an optical disk, and a centering hole provided in a chucking member which is inserted at least partially into the center hole of the disk body. A disk drive device comprising: a centering pin that fits with the disk; and a disk table that rotates an optical disk that is mounted by being centered by one of the centering means and the centering pin.