JP3198115B2 - Disc chucking mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk chucking mechanism used for a disk recording and / or reproducing apparatus for chucking a disk such as an optical disk used as an information signal recording medium.

[0002]

2. Description of the Related Art Hitherto, optical disks have been used as recording media for information signals. As shown in FIG. 2, this optical disc is configured by providing a signal recording layer 102 on one main surface of a disc-shaped disc substrate 101 made of a transparent resin such as polycarbonate, glass, or the like.

In an optical disk exclusively for reading information signals, a pit pattern composed of minute unevenness corresponding to the information signal is formed on one main surface serving as a signal recording surface 102a, and aluminum or the like is formed on the pit pattern. The signal recording layer 102 is formed by providing a reflection film made of a metal thin film. In a magneto-optical disk capable of re-recording an information signal, a signal recording layer 102 is formed by providing a thin film made of a magnetic material and a reflective film made of a metal thin film on a signal recording surface 102a. On the signal recording surface 102a, recording grooves forming recording tracks substantially concentrically or spirally are formed.

[0004] At the center of the disk substrate 101, a disk hub 103 is mounted. Disc hub 10
Numeral 3 is formed in a substantially disk shape from a magnetic material, is fitted in a hub mounting hole 101a formed in the center of the disk substrate 101, and is joined to the disk substrate 101 by an adhesive. A center shaft engaging hole 110 is formed in the center of the disk hub 103.

[0005] An optical disk recording and / or reproducing apparatus using such an optical disk as a recording medium includes a disk rotation drive mechanism for holding and rotating the optical disk, and a light beam for the optical disk rotated and operated by the rotation drive mechanism. And an optical pickup device for irradiating light.
The disk rotation drive mechanism provided in the optical disk recording and / or reproducing apparatus has a chucking mechanism for chucking the optical disk. This chucking mechanism is, as shown in FIG. 2, a spindle shaft 1 of a spindle motor 104 constituting a disk rotation drive mechanism.
04a and a disk table 105 attached to the spindle shaft 104a. The disk table 105 is formed in a substantially disc shape, and has a support hole 109 in the center on the lower surface side in which the spindle shaft 104a is fitted. The disk table 105 has a support hole 109.
The spindle shaft 104a is fitted onto the spindle shaft 104a by being fitted to the lower surface side.

[0006] A peripheral edge of the upper surface of the disk table 105 is formed as an annular disk mounting portion 106. The disk mounting portion 106 supports the optical disk and supports the optical disk at the height position of the optical disk, that is, the disk substrate 1.
01 is positioned in the direction perpendicular to the main surface. Also,
A central shaft 107 protrudes from the center of the upper surface of the disk table 105. The center shaft 107 protrudes above the disk mounting portion 106. An annular magnet 108 is provided around a central shaft 107 on the inner peripheral side of the disk mounting portion 106. The magnet 108 is provided so as not to protrude above the disk mounting portion 106.

In order to chuck the optical disk with the chucking mechanism constructed as described above, the center shaft engaging hole 11 is used.
The central shaft 107 is engaged with the disk hub 103 and the disk hub 103 is placed on the disk table 105. Then, the disc hub 103 is attracted to the disc hub 103 by the magnet 108, and the periphery of the disc hub 103 is moved to the disc mounting section 1.
06, the height position is determined with reference to the disk mounting portion 106, the centering is performed with reference to the central axis 107, and the disk is chucked on the disk table 105.

[0008]

By the way, the disk chucking mechanism sufficiently chucks the disk so that the mounting portion 106 and the disk substrate 101 do not slip each other when rotating the disk. It is necessary to use a magnet 108 having a large magnetic force.

However, if the magnet 108 has a large magnetic force, the size of the magnet 108 increases, and the size of the disk table 105 using the magnet also increases. Therefore, the size of the disk recording and / or reproducing apparatus cannot be reduced.

When the magnetic force of the magnet 108 is increased, the leakage magnetic flux also increases, and there is a possibility that the magnetic flux leaks to the signal recording surface 102a of the optical disk. Signal recording surface 10
If the magnetic flux leaks to 2a, if the disk is a magneto-optical disk, it may affect the signal recording layer 102 made of a magnetic material, making it impossible to accurately record or read information signals.

Therefore, the present invention has been proposed in view of the above situation, and prevents a magnetic flux from leaking to a signal recording surface of a disk, without increasing the size of a mechanism.
An object of the present invention is to provide a disk chucking mechanism that can reliably chuck a disk.

[0012]

[Means for Solving the Problems]

[0013]

In order to solve the above problems and to achieve the above object, a disk chucking mechanism according to the present invention is provided with a magnetic material which has a center hole and covers the center hole on one main surface. A plate consisting of
A mounting portion that abuts on the other main surface of the disk having the signal recording layer on the one main surface side to position the height position of the disk, and is disposed on the inner peripheral side of the mounting portion; A centering member having an outer peripheral surface in contact with an inner peripheral surface of a center hole of the disk mounted on the mounting portion; and a disk disposed on an inner peripheral side of the centering member and supported by the mounting portion. A magnet for bringing one of the magnetic pole portions close to the plate body, and at least an inner peripheral side of the magnet so as to extend from near the other magnetic pole portion of the magnet to the plate body of the disk supported by the mounting portion. And a yoke member,
The magnet and the yoke on the inner peripheral side of the magnet
Closed by the member and the plate whose position is restricted by the mounting part
A magnetic path is formed, and the closed magnetic path has the signal recording layer.
Disposed on the inner peripheral side of the center hole provided in the disc.
The centering member is formed further on the inner peripheral side .

[0014]

A disk chucking mechanism according to the present invention comprises a magnet for attracting a plate attached to one main surface of a disk substrate and a yaw on the inner peripheral side of the magnet.
Provided on the disc whose position is regulated by the
The closed magnetic path is formed by the
Inner circumference of the center hole provided in the disc having the signal recording layer
Since it is formed further on the inner peripheral side of the centering member disposed on the side, it is possible to prevent the magnetic flux from leaking to the outer side of the magnetic path, and the magnetic force of this magnet is concentrated on the plate.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A disk chucking mechanism according to the present invention comprises:
The present invention is applied to a disk rotation drive mechanism of an optical disk recording and / or reproducing apparatus using an optical disk as a recording medium.

As shown in FIG. 1, a disk to be chucked by the disk chucking mechanism according to the present invention is a disk-shaped disk substrate 1 made of transparent resin such as polycarbonate, glass, or the like. The signal recording layer 2 is provided on the main surface. The signal recording layer 2 is formed by providing a thin film made of a magnetic material and a reflective film made of a metal thin film on the signal recording surface 2a. On the signal recording surface 2a, recording grooves forming recording tracks substantially concentrically or spirally are formed. In the case of an optical disk dedicated to reading information signals, the signal recording surface 2a
A pit pattern composed of minute unevenness corresponding to an information signal is formed on one of the main surfaces, and a reflection film made of a metal thin film such as aluminum is provided on the pit pattern to form the signal recording layer 2.

At the center of the disk substrate 1, a circular center hole 1a having a constant diameter is provided so as to penetrate from one main surface to the other main surface. The center hole 1a is formed when the disk substrate 1 is formed by, for example, injection molding. The center hole 1a is formed such that the center coincides with the center of curvature of the recording groove formed on the disk substrate 1. In order to make the center of the center hole 1a coincide with the curvature center of the recording groove, the recording groove may be formed at the same time when the disk substrate 1 is formed. That is, when the disk substrate 1 is formed by injection molding, the center of the center 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. When the recording groove is formed after the molding of the disk substrate, the recording groove may be formed with reference to the center hole 1a.

A plate 3 is attached to one main surface of the disk substrate 1 so as to cover the center hole 1a. The plate 3 is made of a magnetic material such as iron or stainless steel and has a disk shape slightly larger in diameter than the center hole 1a. Plate 3
Are bonded to the disk substrate 1 using an adhesive or the like.

The signal recording layer 2 may be interposed between the plate 3 and the disk substrate 1. Further, the signal recording layer 2 is not formed in a portion of the disk substrate 1 where the plate 3 contacts, so that these plate 3 and the disk substrate 1 are not formed.
And may directly contact with each other.

The chucking mechanism for chucking an optical disk configured as described above is applied to a disk rotation drive mechanism of an optical disk recording and / or reproducing apparatus using the optical disk as a recording medium.

This optical disk recording and / or reproducing apparatus comprises: a disk rotation drive mechanism having a chucking mechanism for chucking an optical disk; and an optical pickup for irradiating a light beam to the optical disk rotated by the rotation drive mechanism. It has a device and the like. In this optical disk recording and / or reproducing apparatus, a light beam emitted from the optical pickup device is applied to the optical disk so as to be focused on the signal recording layer 2 from the other main surface of the disk substrate 1. By scanning the recording groove with the light beam, the recording of the information signal or the reading of the recorded information signal is performed.

As shown in FIG. 1, the chucking mechanism for chucking the optical disk includes a spindle shaft 4 of a spindle motor constituting a disk rotation drive mechanism.
And a disk table 5 attached to the spindle shaft 4. The disk table 5 includes a spindle shaft mounting portion 5a formed of a material having high magnetic permeability and serving as a yoke member, and a table portion 5b mounted on the outer peripheral side of the spindle shaft mounting portion 5a and provided with a disk mounting portion 6. .

The spindle shaft mounting portion 5a is formed in a substantially disk shape, and a cylindrical spindle shaft insertion portion 9 through which the spindle shaft 4 is inserted is protruded at the center. The spindle shaft mounting portion 5a is mounted so that the spindle shaft 4 is press-fitted into the spindle shaft insertion portion 9 from the lower surface side and rotates integrally with the spindle shaft 4.

The table section 5b includes a spindle shaft mounting section 5
The upper surface, which is formed so as to increase in diameter from the side of the mounting portion to the front end side toward the front end and has a flat ring-like surface, is used as the disk mounting portion 6. The mounting portion 6 supports the disk substrate 1 of the disk and positions the mounting position of the disk on the disk table 5.

A centering member 7 is provided on the upper surface side of the disk table 5 and on the inner peripheral side of the table portion 5b.
Are arranged. The centering member 7 is formed in an annular shape from synthetic resin or the like, and has a tapered portion 7a formed on the outer peripheral surface on the distal end side. The tapered portion 7a is formed so as to reduce the diameter of the centering member 7 from the base end toward the distal end. The centering member 7 is supported by a ring-shaped leaf spring 10 formed of a steel plate or the like stretched between the outer peripheral surface of the centering member 7 and the inner surface of the table portion 5b of the disk table 5. At this time,
The centering member 7 is supported by the ring-shaped leaf spring 10 such that a tip end portion on which the tapered portion 7a is formed projects above the mounting portion 6 of the table portion 5b. The ring-shaped leaf spring 10 is formed with a plurality of displacement arms extending between the centering member 7 and the table 5b. These displacement arms are formed, for example, to be radially arranged. The centering member 7 moves in a direction orthogonal to the mounting portion 6 which is the axial direction of the spindle shaft 4 by the elastic displacement of the displacement arm of the ring-shaped leaf spring 10.

On the inner peripheral side of the centering member 7, a magnet 8, which is formed in a cylindrical shape coaxially with the spindle shaft mounting portion 5a, is disposed so as to be supported by the spindle shaft mounting portion 5a serving as a yoke member. . This magnet 8
Is magnetized in the thickness direction such that one end is one magnetic pole and the other end is the other magnetic pole.

In order to chuck a disk with the disk chucking mechanism according to the present invention configured as described above, the tapered portion 7a of the centering member 7 is engaged with the central hole 1a of the disk substrate 1, Disk substrate 1
Is mounted on the mounting portion 6 of the disk table 5. Then, the magnet 8 is attached to the plate 3 attached to the disk substrate 1.
And the central hole 1a on the other main surface side of the disk substrate 1
Is pressed against the mounting portion 6. At this time, the mounting height position of the disk substrate 1 with respect to the disk table 5 is determined based on the mounting portion 6.

When the disk substrate 1 is mounted on the mounting portion 6 of the disk table 5, the centering member 7
The ring-shaped leaf spring 10 is brought into contact with the peripheral end of the center hole 1a.
Is displaced toward the base end side of the spindle shaft 4. The centering member 7 returns to the initial position by the elastic force of the ring-shaped leaf spring 10 as indicated by an arrow A in FIG.
And presses the tapered portion 7a against the inner peripheral surface of the center hole 1a. As described above, the ring-shaped leaf spring 10 presses the tapered portion 7a against the inner peripheral surface of the center hole 1a, so that the disk substrate 1 is positioned between the center of the center hole 1a and the spindle shaft 4 which is the rotation center of the disk table 5. The centering is performed so that the center coincides with the center.

When the disk is mounted on the disk table 5, the cylindrical spindle shaft insertion portion 9 protruding from the center of the spindle shaft mounting portion 5a and one end of the magnet 8 are
It faces the plate 3 attached to the disk substrate 1 with a slight gap. The magnet 8 forms a closed magnetic path from the magnet 8 through the spindle shaft insertion portion 9 provided on the spindle shaft mounting portion 5a and the plate 3. That is, the magnetic flux from the magnet 8 passes through the spindle shaft mounting portion 5a, reaches the plate 3 from the spindle shaft insertion portion 9 close to the plate 3, and forms a closed magnetic path returning to the magnet 8 from the plate 3. I do. As described above, the magnetic flux from the magnet 9 is prevented from leaking to the disk placed on the disk table 5 by passing through the closed magnetic path, and the information signal recorded on the signal recording layer 2 of the disk is prevented. Will not be affected. Further, since almost all of the magnetic flux of the magnet 8 passes through the closed magnetic circuit, it can be effectively used for attracting the plate 3.

The plate 3 attached to the disk substrate 1 is preferably formed to have a thickness of, for example, about 0.3 mm or more so that the magnetic flux of the magnet 8 can be transmitted without leaking outward.

In the optical disk chucked by the chucking mechanism according to the present invention, the disk substrate 1 is supported by the mounting portion 6, the mounting height position is determined, and the centering is performed by the centering member 7. Since the disk is mounted on the disk table 5, the disk is positioned at the mounting height position with reference to the disk substrate 1 regardless of the mounting position of the plate 3 with respect to the disk substrate 1, and the rotation center is positioned at the rotation center of the disk table. Centering is achieved.

The optical disk held by the chucking mechanism is rotated integrally with the disk table 5 by the rotation of the spindle motor 4. Then, the optical disk is irradiated with a light beam by the optical pickup device to record or read information signals.

[0033]

As described above, the disk chucking mechanism according to the present invention comprises a magnet for attracting a plate attached to a disk substrate and an inner periphery of the magnet.
The yoke member on the side and the disc whose position is
Since the closed magnetic path is formed by the provided plate, the leakage of the magnetic flux from the magnet can be reduced, and the disk can be concentrated on the plate of the disk substrate. Can be king.

Further, since the magnetic flux of the magnet can be concentrated on the plate of the disk substrate, a small magnet can be used, and the size of the mechanism can be reduced, and recording and / or recording using the disk chucking mechanism can be achieved. The size of the playback device can be reduced.

Further, since the leakage of the magnetic flux from the magnet can be reduced, the recording or reading of the information signal is performed.
Magnetic pickup device
Minimize the effect and ensure accurate operation of the optical pickup device.
In other words, accurate information signal recording or reading can be performed.
it can. When a disk that magnetically records information signals is used , information signals can be recorded or read accurately without being affected by magnetic flux leakage.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a disk chucking mechanism according to the present invention.

FIG. 2 is a longitudinal sectional view showing a conventional disk chucking mechanism.

[Explanation of symbols]

1 disk board, 1a center hole, 3 plate, 5
Disk table, 5a spindle shaft mounting part, 5
b table part, 6 mounting part, 7 centering member, 8 magnet.

──────────────────────────────────────────────────続 き Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G11B 17/00 G11B 23/00

Claims (1)

(57) [Claims] 1. A center hole is provided, and a plate made of a magnetic material covering the center hole is attached to one main surface, and the other main surface of a disk having a signal recording layer on the one main surface side is provided on the other main surface. A mounting portion that abuts and positions the height position of the disk; and a mounting portion that is disposed on an inner peripheral side of the mounting portion and that has an outer periphery on an inner peripheral surface of a center hole of the disk mounted on the mounting portion. A centering member to which a surface abuts; a magnet disposed on the inner peripheral side of the centering member, the magnet having one magnetic pole portion approaching the plate of the disk supported by the mounting portion; and the other of the magnet A yoke member disposed at least on the inner peripheral side of the magnet so as to extend from the vicinity of the magnetic pole portion to the vicinity of the plate body of the disk supported by the mounting portion, wherein the yoke member is provided on the inner peripheral side of the magnet. yoke
Closed by the member and the plate whose position is restricted by the mounting part
A magnetic path is formed, and the closed magnetic path has the signal recording layer.
Disposed on the inner peripheral side of the center hole provided in the disc.
Formed on the inner peripheral side of the centering member
A disc chucking mechanism.