JPH04283432A - Recording disk - Google Patents

Abstract

PURPOSE:To prevent the removing of a disk hub from a disk substrate and to obviate the generation of deformation in the disk substrate even if the disk hub and the disk substrate thermally expand or shrink differently. CONSTITUTION:Plural projecting pieces 5 and plural pawl parts 6 are provided in the circumferential part of the disk hub 4 and the circumferential part of a center hole 2 is crimped by these projecting pieces 5 and pawl parts 6, by which the disk hub 4 is mounted to the disk substrate 1.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording disk, such as a so-called optical disk or a magneto-optical disk, which serves as a recording medium for information signals.

0002

2. Description of the Related Art Conventionally, recording disks for recording and/or reproducing information signals, such as so-called optical disks and magneto-optical disks, have been proposed. This recording disk has a disk-shaped disk substrate, and one main surface of the disk substrate is configured as a signal recording surface. This disk substrate is made of a transparent synthetic resin material such as polycarbonate. A signal recording layer made of a magnetic material film, a metal film, or the like is deposited on the other main surface of the disk substrate. That is,
Writing and/or reading of information signals to and from the signal recording layer is performed by irradiating the signal recording layer with a light beam from one main surface of the disk substrate, which is the signal recording surface, through the disk substrate. be exposed.

The central portion of this recording disk is a chucked portion that is held by a so-called disk player device that writes and/or reads information signals to and from the recording disk. The chucked part is composed of a center hole provided in the center of the disk substrate, and a metal plate attached to the other main surface of the disk substrate so as to close the center hole. ing. The center hole is formed substantially concentrically and spirally on the signal recording surface, and is located at the center of curvature of the recording track on which the information signal is written.
It is formed by aligning the centers.

[0004]The recording disc is placed and held on a disc table in the disc player device. This disk table is formed into a disk shape with a larger diameter than the center hole, and is attached to the drive shaft of the spindle motor. A truncated conical centering projection having a diameter approximately corresponding to the center hole is provided on the upper surface of the disc table. Further, a magnet is provided within this centering protrusion.

[0005] When this recording disk is placed on the disk table with the center side of one main surface in contact with the disk table, the centering protrusion is located in the center hole of the recording disk. By being inserted, a so-called centering operation is performed in which the center of the center hole is aligned with the center of the centering protrusion. The recording disk is held with one main surface in contact with the upper surface of the disk table by the metal plate being attracted by the magnet.

[0006]

By the way, in the recording disk as described above, the metal plate is bonded to the disk substrate by means such as bonding using an adhesive.
installed. Since this adhesive must adhere to both the synthetic resin material such as polycarbonate forming the disk substrate and the metal material forming the metal plate, the types of adhesives that can be used are limited.

Furthermore, since the synthetic resin material forming the disk substrate and the metal material forming the metal plate have different coefficients of thermal expansion, they tend to peel off when the environmental temperature changes. On the other hand, if the disk substrate and the metal plate are firmly attached so as not to cause peeling, there is a risk that the disk substrate will be distorted due to changes in environmental temperature, and so-called birefringence will occur within the disk substrate. . If birefringence occurs within the disk substrate, it is impossible to write and/or read information signals into and/or from the signal recording layer.

The present invention has been proposed in view of the above-mentioned circumstances, and even if the plate-like body attached to the disk substrate is made of a different material from the disk substrate, It is an object of the present invention to provide a recording disk which can be reliably attached to the disk substrate and which can prevent distortion of the disk substrate due to changes in environmental temperature or the like.

[0009]

[Means for Solving the Problems] In order to solve the above-mentioned problems and achieve the above-mentioned objects, a recording disk according to the present invention is a disk in which at least one main surface is a signal recording surface and a through hole is provided in the center. It comprises a substrate, and a plate-shaped body disposed on one main surface of the disk substrate so as to close the through hole, and the plate-shaped body has a plurality of abutment pieces and a plurality of abutment pieces on the peripheral side. It has a locking claw portion, and these contact pieces are brought into contact with one main surface portion of the disk substrate, and the locking claw portions are inserted into the through hole and locked to the disk substrate. This is what happens.

0010

[Operation] The recording disk according to the present invention is arranged on one main surface of a disk substrate having at least one main surface serving as a signal recording surface and a through hole provided in the center, with the through hole closed. The provided plate-shaped body brings the plurality of abutting pieces provided on the peripheral side into contact with one main surface of the disk substrate, and the plurality of locked claws provided on the peripheral side. Since it enters the through hole and is locked to the disk substrate, it will not fall off from the disk substrate even if thermal expansion or contraction differs from that of the disk substrate due to changes in environmental temperature, etc. Moreover, no distortion is caused in the disk substrate.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below with reference to the drawings. In this example, the recording disk according to the present invention is configured as a so-called magneto-optical disk.

[0012] As shown in FIG. 1, this recording disc has the following features.
It is configured with a disk substrate 1. The disk substrate 1 is formed into a disk shape from a material such as a transparent synthetic resin such as polycarbonate. A signal recording layer made of a magnetic material is deposited on one main surface of the disk substrate 1 . The other main surface of the disc substrate 1 serves as a signal recording surface on which information signals are written and/or read by the disc player. That is, information signals are written to and/or read from the signal recording layer from the signal recording surface, which is the other main surface of the disk substrate 1, through the disk substrate 1 and into the signal recording layer. , is performed by irradiating with a light beam.

A center hole 2, which is a through hole, is provided in the center of the disk substrate 1, and a disk hub 4, which is a plate-shaped member, is attached to correspond to the center hole 2. The center hole 2 is a circular hole penetrating the disk substrate 1 from one main surface to the other main surface.

Further, as shown in FIG. 2, on the other main surface of the disk substrate 1, an annular protrusion 7 is provided around the center hole 2. The protruding portion 7 is provided so that the inner diameter, that is, the diameter of the inner wall portion 8 is slightly larger than the diameter of the center hole 2. This protrusion portion 7 serves as a positional reference when the disc player apparatus centers and holds this recording disc. That is, this protruding portion 7 is connected to the inner wall portion 8.
The center of the recording track is provided so as to coincide with the center of curvature of a recording track formed in a substantially concentric spiral shape on the signal recording layer.

The disc hub 4 is formed of a material such as a metal plate and has a disc-shaped main body having a diameter approximately equal to the center hole 2. A plurality of substantially rectangular plate-shaped contact pieces 5 are integrally provided around the main body of the disc hub 4 so as to be flush with the main surface of the main body. These contact pieces 5 are arranged radially around the main body of the disk hub 4, and are spaced apart from each other at equal angular intervals. Further, a plurality of substantially rectangular plate-shaped engaged claw portions 6 are integrally provided on the periphery of the main body of the disc hub 4 in a protruding manner. These engaged pawls 6 are substantially perpendicular to the main surface of the main body of the disc hub 4, surround the main body, and are located between the proximal ends of the contact pieces 5. It is provided with the proximal end side positioned. These engaged claw portions 6 are provided to protrude from the main body portion of the disk hub 4 in the same direction.

Each of the abutment pieces 5 and the engaged claws 6 are provided with radial notches at equal angular intervals on the peripheral side of the disc-shaped plate that becomes the disc hub 4. ,
A plurality of substantially rectangular plate-shaped portions, which are the portions between the cut portions, can be formed by bending every other portion substantially perpendicularly in the same direction.

The disk hub 4 is disposed on one main surface of the disk substrate 1 so as to close the center hole 2. A disk hub mounting recess 3 is provided on one main surface of the disk substrate 1 so as to surround the center hole 2 . This disc hub mounting recess 3 is located at the disc hub 4.
It is formed to have a diameter corresponding to the diameter of a circle circumscribing the tip of each of the abutment pieces 5 and a depth corresponding to the thickness 5 of the disk hub 4 . The disc hub 4 is disposed so as to be fitted into the disc hub mounting recess 3 together with each of the contact pieces 5. Therefore, in this disk hub 4, the upper main surface, that is, the main surface on the side opposite to the side that contacts the disk substrate 1, is flush with one main surface of the disk substrate 1. . In the disc hub 4, each of the contact pieces 5 is connected to the center hole 2 in the disc hub mounting recess 3.
By coming into contact with the peripheral side portion of the disk substrate 1, movement of the disk substrate 1 in the direction toward the other main surface portion is restricted.

Each of the engaged claw portions 6 is inserted into the center hole 2 along the periphery of the center hole 2, respectively. The distal end portions of these engaged claw portions 6 protrude toward the other main surface of the disk substrate 1, and the distal end portions are bent toward the outside of the center hole 2. The disc hub 4 is thus configured such that the distal end portion of each engaged claw portion 6 is bent toward the outside of the center hole 2 on the other main surface side of the disc substrate 1. , is locked by the peripheral side of the center hole 2 of the disk substrate 1, and movement of the disk substrate 1 in the side direction of one main surface is restricted. That is, the disc hub 4 is configured such that the peripheral side of the center hole 2 of the disc substrate 1 is held between the contact pieces 5 and the distal end portions of the engaged claws 6. , attached to the disk substrate 1. This disk hub 4 holds the peripheral side of the center hole 2 of the disk substrate 1 in a slightly loose state so that a slight gap is created.

Note that, as mentioned above, each of the engaged claw portions 6
In order to bend the tip end portion of the disk substrate 1 toward the outer periphery of the center hole 2 on the other main surface side of the disk substrate 1, first, as shown in FIG.
It is inserted into the center hole 2 with the distal end portion unbent. Then, the disk hub 4 is held between the first and second pressing jigs 101 and 102, and the disk substrate 1 is held as shown by the arrow P in FIG.
Pressing is performed in the direction perpendicular to the main surface.

The first jig 101 is formed into a cylindrical shape having a diameter approximately equal to the diameter of the main body of the disk hub 4. The distal end surface of the first jig 101 that is brought into contact with the disk hub 4 is made into a flat surface, and the peripheral portion is chamfered to form a tapered portion 1.
01a. This first jig 101 is disposed on the other main surface side of the disk substrate 1 with its central axis corresponding to the center of the disk substrate 1. Further, the second jig 102 is formed into a cylindrical shape having a diameter approximately equal to the diameter of the circumscribed circle of the tip of each of the abutment pieces 5, and the tip surface that comes into contact with the disk hub 4 is a flat surface. It is said that This second jig 102 is disposed on one main surface side of the disk substrate 1 with its central axis approximately corresponding to the center of the disk substrate 1.

The disk hub 4 held between the jigs 101 and 102 is connected to the main body and the contact pieces 5.
is brought into contact with the distal end surface of the second jig 102 and its position is regulated, and the distal end side of each of the engaged claw portions 6 is brought into contact with the distal end surface of the second jig 102.
01 taper portion 101a. Then, due to the pressing force in the direction in which these jigs 101 and 102 approach,
The tip side portion of each of the engaged claw portions 6 is connected to the tapered portion 10.
1a, and is bent along the center hole 2.
It is bent outward.

In the recording disk according to the present invention configured as described above, the disk hub 4 is connected to the disk substrate by the respective abutting pieces 5 and the distal end portions of the respective engaged claw portions 6. Since it is attached to the disk substrate 1 so as to loosely sandwich the peripheral side of the center hole 2 of the disk substrate 1, even if the disk substrate 1 undergoes thermal expansion or contraction different from that of the disk substrate 1 due to changes in environmental temperature, etc. It will not fall off from the disk substrate 1 and will not cause distortion to the disk substrate 1.

[0023] During use, this recording disc is placed on a disc table attached to the drive shaft of the spindle motor of the disc player. The disk table is formed into a disk shape having a larger diameter than the inner wall portion 8 of the protrusion portion 7, and is supported by the drive shaft. The above-mentioned protrusion 7 is provided on the upper surface of this disc table.
The tip of the is placed.

A centering protrusion is provided on the disk table. This centering protrusion is formed into a substantially truncated cone shape with a diameter smaller on the distal end side than on the proximal end side supported by the disk table,
It has an outer diameter that allows it to be inserted halfway into the protruding portion 7. This centering protrusion is provided on the disk table with its center aligned with the axis of the drive shaft of the spindle motor. Further, a magnet for attracting the disk hub 4 is built into this centering protrusion.

When the disk substrate 1 is placed on the disk table, the magnet built into the centering protrusion attracts the disk hub 4.
The centering projection brings its outer peripheral surface into contact with the inner wall 8 of the protrusion 7. This centering protrusion allows a so-called centering operation in which the center of the protrusion 7 is brought into alignment with the center of the centering protrusion by bringing the outer circumferential surface into contact with the inner wall 8 of the protrusion 7. conduct. In this way, the disk substrate 1 is positioned at a predetermined position relative to the disk table by the upper surface of the disk table and the centering protrusion.

As described above, in the recording disk according to the present invention mounted in the disk player device, the disk substrate 1 is rotated together with the disk table by the disk table being rotated by the spindle motor. be done.

[0027] In the disc player device, the optical pickup device writes and/or reads information signals to and from the signal recording layer. This optical pickup device faces the signal recording surface and is operated to move over the inner and outer peripheries of the signal recording surface, corresponding to at least the signal recording area. This optical pickup device includes an objective lens, and irradiates the signal recording layer with a beam of light through the objective lens through the disk substrate 1 to send an information signal to the signal recording layer. Write and/or read data.

Note that the recording disk according to the present invention is not limited to that configured as a so-called magneto-optical disk as shown in the above embodiments, but may also be a so-called optical disk,
Alternatively, it may be configured as a magnetic disk.

Further, the recording disk according to the present invention is rotatably housed in a thin housing-like cartridge having a rectangular main surface portion whose length on one side is slightly longer than the diameter of the disk substrate 1, and the recording disk is rotatably housed in a cartridge. It may also be used as a recording disk constituting a.

[0030]

As described above, in the recording disk according to the present invention, at least one main surface is a signal recording surface, and a through hole is provided in the center of the disk substrate. The plate-shaped body disposed to close the hole brings the plurality of contact pieces provided on the peripheral side into contact with one main surface of the disk substrate, and also contacts the plurality of contact pieces provided on the peripheral side with one main surface of the disk substrate. The latched claw portion of the disc is inserted into the through hole and is latched to the disk substrate.

[0031] Therefore, in this recording disc,
Even if the plate-like body and the disk substrate undergo different thermal expansions or contractions due to changes in environmental temperature or the like, the plate-like body will not fall off from the disk substrate. Further, even when such a temperature change occurs, the plate-like body does not generate stress in the disk substrate, but does not cause distortion in the disk substrate that would cause birefringence in the disk substrate. There is no.

That is, the present invention allows the plate-shaped body to be attached to the disk substrate to be securely attached to the disk substrate even when the plate-shaped body is made of a different material from the disk substrate, and to maintain the environmental temperature. It is possible to provide a recording disk in which distortion is prevented from occurring in the disk substrate due to changes in the temperature.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing a part of the configuration of a recording disk according to the present invention.

FIG. 2 is an enlarged vertical cross-sectional view of a main part showing the structure of the main part of the recording disk.

FIG. 3 is an enlarged longitudinal cross-sectional view of a main part showing a state in which the recording disk is in the middle of being manufactured.

[Explanation of symbols]

1......Disk board 2...
・・・・・・Center Hall 4・・・・・・・・・・・・
・・Disc hub 5・・・・・・・・・・・・Abutting piece part

Claims (1)

[Claims] Claim 1: A disk substrate having at least one main surface serving as a signal recording surface and a through hole provided in the center, and a disk substrate with the through hole closed and disposed on one of the main surfaces of the disk substrate. The plate-like body has a plurality of abutting pieces and a plurality of locked pawls on the peripheral side, and these abutting pieces are attached to one main surface of the disk substrate. The recording disk is configured such that the locking claws enter the through holes and lock onto the disk substrate.