JPH04232680A - Optical disk and optical disk chucking mechanism - Google Patents

Abstract

PURPOSE:To easily position an optical disk with high accuracy by fitting a plate body made of a magnetic material to a disk substrate and, at the same time, providing a tapered section and magnet in a chucking section. CONSTITUTION:A plate body 3 made of a magnetic material is fitted to an optical disk so as to close the center hole 1a of the disk substrate 1 of the optical disk and a chucking section is provided with a tapered section 7 and magnet 8. At the time of chucking the optical disk, the height of the disk is controlled in such a way that the plate body 3 of the disk is attracted by the magnet 8 and brought into contact with a placing section 6. In addition, since the inside section of the center hole 1a of the disk is brought into contact with the tapered section 7, the position of the disk is controlled in the radial direction and the disk is stably held.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc for recording information signals and an optical disc chucking mechanism for holding the optical disc in a so-called optical disc player device.

0002

2. Description of the Related Art Conventionally, optical discs have been proposed as recording media for information signals. As shown in FIG. 2, this optical disc includes a disc-shaped disc substrate 101 made of transparent resin such as polycarbonate, glass, etc.;
01 and a signal recording layer 102 provided on one main surface portion of the main surface.

[0003] The signal recording layer 102 is formed of a metal thin film such as aluminum in an optical disc for reading only information signals. Further, the signal recording layer 10
2, in the case of optical discs such as so-called magneto-optical discs on which information signals can be written and read,
It is formed from a thin film made of a predetermined magnetic material. The surface portion of this signal recording layer 102 is a signal recording surface 102a. Then, on this signal recording surface 102a,
A spiral recording groove is formed so as to be substantially concentric.

[0004] A so-called optical disc player device is used to write and/or read information signals to and from the optical disc. This optical disc player device includes a rotary drive device that holds and rotates the optical disc, and an optical pickup device that irradiates a light beam such as a laser beam onto the optical disc that is rotated by the rotary drive device. has been done.

[0005] In this optical disc player device,
By the optical pickup device, the signal recording surface 10
A light beam is condensed and irradiated onto 2a, and information signals are written and/or read out. The optical disc is irradiated with a light beam from the other main surface side of the disc substrate 101. That is, the light flux passes through the disk substrate 101 and is irradiated onto the signal recording surface 102a. Further, the light beam is irradiated by the optical pickup device so as to trace the recording groove.

The rotary drive device of the disc player device has an optical disc chucking mechanism for holding the optical disc. In order to reduce the size of the device configuration, this optical disk chucking mechanism uses an optical disk with a disk hub made of magnetic material such as iron, stainless steel, or nickel attached to the center, and this disk hub is attracted by a magnet. A device that holds the optical disc has been proposed.

This optical disc chucking mechanism is shown in FIG.
As shown in FIG.
The disc table 105 is attached to the disc table 105. The disk table 105 is formed into a substantially disk shape, and a support hole 109 into which the rotating shaft 104a is inserted is provided in the center of the lower surface. That is, the disk table 105 is attached to the rotating shaft 104a by press-fitting the rotating shaft 104a into the support hole 109 from below.

[0008] The upper peripheral edge portion of the disc table 105 is formed into an annular mounting portion 106 . This mounting portion 106 is for contacting the optical disc to regulate the height position of the optical disc, that is, the position in the direction perpendicular to the main surface of the disc substrate 101. Further, a spindle shaft 107 is provided protruding from the center of the upper surface of the disk table 105 . This spindle shaft 107 protrudes upward from the mounting portion 106 . An annular magnet 108 is provided on the inner peripheral side of the mounting portion 106, that is, around the spindle shaft 107. The upper surface of the magnet 108 is configured not to protrude upward beyond the placement portion 106 .

On the other hand, the disc substrate 10 of the optical disc
1 has a disk hub 103 attached to its center. The disk hub 103 is formed of a magnetic material into a substantially disk shape, is fitted into a hub mounting hole 101a drilled in the center of the disk substrate 101, and is further bonded using adhesive or the like. Disk board 1
It is attached to 01. A center hole 110 into which the spindle shaft 107 is inserted is bored in the center of the disk hub 103.

In order to hold the optical disc by the optical disc chucking mechanism, the center hole 1
10, and place the disk hub 103 on the disk table 105. Then, the magnet 108 attracts the disc hub 103 and presses the peripheral portion of the disc hub 103 against the mounting portion 106 . In this way, the height position of the optical disc held by the optical disc chucking mechanism is regulated with respect to the mounting section 106, and
The rotating shaft 10 is based on the spindle shaft 107.
4a so that there is no eccentricity in the horizontal direction, i.e.
The radial position of the disk substrate 101 is regulated.

[0011]

By the way, when the optical disc held by the optical disc chucking mechanism is rotated, the center of curvature of the recording groove formed on the signal recording surface 102a is aligned with the rotation axis 104a of the motor 104.
If the recording groove is eccentric with respect to the rotation center of the optical disc, the recording groove will periodically move in the radial direction of the optical disc. If the amount of movement of the recording groove is large, it becomes difficult for the optical pickup device to irradiate the recording groove with a beam of light, making it impossible to write and/or read information signals satisfactorily.

In the optical disc and optical disc chucking mechanism as described above, the horizontal position of the optical disc is regulated by the fit between the spindle shaft 107 and the center hole 110. Therefore, in this optical disc, when attaching the disc hub 103 to the disc substrate 101, it is necessary to align the center of the center hole 110 with the center of curvature of the recording groove.

That is, in manufacturing the optical disc, the disc hub 103 is positioned with high precision with reference to the recording groove, and the disc hub 103 is positioned on the disc substrate 10 with high precision.
1, the process is complicated.

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above-mentioned circumstances, and provides an optical disc that can be manufactured easily and that can be well controlled in position using an optical disc chucking device, and an optical disc that can be easily manufactured. An object of the present invention is to provide an optical disc chucking mechanism that can hold an optical disc well.

[0015]

[Means for Solving the Problems] In order to solve the above-mentioned problems and achieve the above-mentioned objects, an optical disc according to the present invention includes a disc-shaped disc substrate provided with a signal recording layer, and a central part of the disc substrate. a central hole centered at the center of curvature of a recording groove formed in the signal recording layer; and a plate made of a magnetic material attached to one main surface of the disk substrate so as to close the central hole. It is equipped with the following.

In the optical disk chucking mechanism according to the present invention, a center hole is formed in the center of a disk substrate, and a plate made of a magnetic material is provided on one main surface of the disk substrate to close the center hole. an annular mounting part that comes into contact with the other main surface of the disc substrate of the mounted optical disc to regulate the height position of the optical disc; and a ring-shaped mounting part that is provided protruding from the inner circumferential side of the mounting part and the other side of the center hole. A tapered part that comes into contact with a peripheral end on the main surface side of the plate, and a magnet that is disposed on the inner peripheral side of this tapered part and attracts the plate.

[0017]

[Operation] In the optical disc and optical disc chucking mechanism according to the present invention, the optical disc is chucked by the plate attached to one main surface of the disc substrate being attracted to the magnet of the optical disc chucking mechanism. The other main surface of the disk substrate is brought into contact with the mounting portion of the mechanism to regulate the height position, and the other side of the center hole is bored in the center of the disk substrate in the tapered portion of the optical disk chucking mechanism. Since the radial position of the disk substrate is regulated by abutting the circumferential edge on the main surface side of Location is restricted.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the optical disc according to the present invention includes a disc-shaped disc substrate 1 made of transparent resin such as polycarbonate, glass, or the like. A signal recording layer 2 is provided on one main surface side of the disk substrate 1.
is provided.

The signal recording layer 2 is formed of a thin film made of a predetermined magnetic material, and is capable of writing and reading information signals. The surface portion of this signal recording layer 2 is
This is a signal recording surface 2a. A recording groove (not shown) is formed in the signal recording surface 2a in a spiral shape so as to be substantially concentric. In addition,
The signal recording layer 2 is formed of a metal thin film such as aluminum in the case of an optical disc exclusively for reading information signals.

[0020] Then, the disc substrate 1 of the optical disc
A circular central hole 1a is bored in the center. This central hole 1a is formed to penetrate from one main surface side of the disk substrate 1 to the other main surface side and have a constant diameter. The central hole 1a is formed at the same time as the disk substrate 1 is formed by, for example, injection molding. The center hole 1a is formed so that its center coincides with the center of curvature of the recording groove. In order to match the center of the central hole 1a and the center of curvature of the recording groove in this way, when forming the disk substrate 1,
The recording groove may be integrally formed. That is, when the disk substrate 1 is formed by injection molding, the center of the central hole 1a and the center of curvature of the recording groove are made to coincide with each other depending on the accuracy of the mold for forming the disk substrate 1. Further, the recording groove may be formed using the central hole 1a as a reference.

On one main surface of the disk substrate 1,
A plate 3 is attached so as to close the central hole 1a. The plate 3 is made of a magnetic material such as iron, stainless steel, or nickel, and is formed into a disk shape with a slightly larger diameter than the central hole 1a. This plate body 3 is attached to the disk substrate 1 by means such as bonding using an adhesive or adhesive.

Note that the signal recording layer 2 may be interposed between the plate body 3 and the disk substrate 1. Further, the signal recording layer 2 may not be formed on the portion of the disk substrate 1 that the plate 3 comes into contact with, and the plate 3 and the disk substrate 1 may come into direct contact with each other.

The optical disc chucking mechanism according to the present invention is applied to a so-called optical disc player device that writes and/or reads information signals to and from the optical disc. The disc player device with the above light is
It is configured to include a rotary drive device that holds and rotates the optical disk, and an optical pickup device that irradiates the optical disk, such as a laser beam, to the optical disk that is rotated by the rotary drive device.

[0024] In this optical disc player device,
The optical pickup device allows the signal recording surface 2a to
A light beam is focused and irradiated onto the signal recording layer 2.
Information signals are written to and/or read from. The optical disc is irradiated with a light beam from the other main surface side of the disc substrate 1. That is, the light beam passes through the disk substrate 1 and is irradiated onto the signal recording surface 2a. Further, the light beam is irradiated by the optical pickup device so as to trace the recording groove.

The optical disc chucking mechanism is used in the rotary drive device to hold an optical disc. This optical disc chucking mechanism, as shown in FIG.
The disc table 5 is attached to a. The disk table 5 is formed into a substantially disk shape, and is provided with a support hole 9 in the center thereof into which the rotation shaft 4a is inserted. That is, in this disc table 5, the rotating shaft 4a is press-fitted into the supporting hole 9 from the lower surface side,
It is attached to the rotating shaft 4a.

The upper peripheral edge portion of the disk table 5 is formed into a flat annular mounting portion 6. As shown in FIG. This mounting section 6 is a disc substrate 1 for the optical disc.
This is for regulating the height position of the optical disc, that is, the position in the direction perpendicular to the main surface of the disc substrate 1. Further, a tapered portion 7 is provided protruding from the inner circumferential side of the mounting portion 6 on the upper surface side of the disk table 5 . This tapered part 7 is formed to protrude upward from the above-mentioned mounting part 6, and is gradually reduced in diameter from the lower proximal end to the upper distal end, and is formed into a substantially conical shape. has been done. An annular magnet 8 is provided on the inner peripheral side of the tapered portion 7, that is, around the support hole 9. The upper surface of the magnet 8 is configured not to protrude upward beyond the tip of the tapered portion 7.

In order to hold the optical disc configured as described above by the optical disc chucking mechanism, the tapered portion 7 is inserted into the central hole 1a, and the disc substrate 1 is placed on the disc table 5. Place it on. Then, the magnet 8 attracts the plate 3 and presses the area around the central hole 1a on the other main surface side of the disk substrate 1 to the mounting portion 6. At this time, the tapered portion 7 is in contact with the peripheral end portion of the center hole 1a on the other main surface side. Further, the tip of the tapered portion 7 and the upper end surface of the magnet 8 face the plate 3 with a slight gap therebetween.

The height of the optical disc thus held by the optical disc chucking mechanism is regulated by the disc substrate 1 coming into contact with the mounting portion 6, and the tapered portion 7 has the center hole 1a. The radial position of the disk substrate 1 is regulated by abutting the peripheral end on the other main surface side. Therefore, the position of the optical disc is regulated with respect to the disc substrate 1, regardless of the attachment position of the plate 3 to the disc substrate 1.

The optical disc held by the optical disc chucking mechanism is rotated integrally with the disc table 5 by rotationally driving the motor 4. Information signals are written to and/or read from this optical disc by the optical pickup device in the optical disc player device.

[0030]

As described above, in the optical disc and optical disc chucking mechanism according to the present invention, the plate attached to one main surface of the disc substrate is attracted to the magnet of the optical disc chucking mechanism. As a result, the other main surface of the disk substrate is brought into contact with the mounting portion of the optical disk chucking mechanism to regulate the height position, and the tapered portion of the optical disk chucking mechanism is provided with a hole in the center of the disk substrate. The radial position of the disk substrate is regulated by abutting the peripheral end of the other main surface of the provided center hole.

That is, the position of the optical disc is regulated by the optical disc chucking mechanism with respect to the disc substrate, regardless of the attachment position of the plate body to the disc substrate. Therefore, the above plate is
There is no need for highly accurate positioning and attachment to the disc substrate, and the manufacturing of this optical disc does not become complicated.

That is, the present invention provides an optical disc that can be easily manufactured and that can properly control the position using an optical disc chucking device, and an optical disc chucking mechanism that can properly hold the optical disc. It is something that can be done.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing the configuration of an optical disc and an optical disc chucking mechanism according to the present invention.

FIG. 2 is a vertical cross-sectional view showing the configuration of a conventional optical disc and an optical disc chucking mechanism.

[Explanation of symbols]

1......Disk board 1a...
・・・・・・Center hole 2・・・・・・・・・Signal recording layer 3・・・・・・
...Plate body 6 ...... Placement part 7 ...... Taper part

Claims (2)

[Claims] 1. A disk-shaped disk substrate provided with a signal recording layer; a center hole bored in the center of the disk substrate and centered at the center of curvature of a recording groove formed in the signal recording layer; and a plate made of a magnetic material attached to one main surface of the disk substrate so as to close the center hole. 2. The other side of the disk substrate of an optical disk, in which a center hole is bored in the center of the disk substrate, and a plate made of a magnetic material is attached to one main surface of the disk substrate to close the center hole. an annular mounting part that comes into contact with the main surface and regulates the height position of the optical disc; and a peripheral end on the other main surface side of the center hole that protrudes from the inner circumferential side of the mounting part. An optical disc chucking mechanism comprising: a tapered part that comes into contact with the plate; and a magnet that is disposed on the inner circumferential side of the tapered part and attracts the plate.