JPH10222905A - Disk clamp mechanism of optical disk reproducing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a magnet as a separate component to be combined with a clamper and prevent a disk slip in a disk clamp mechanism by magnetizing only a center portion of the clamper required for clamping a disk and providing a grip member in a peripheral portion thereof. SOLUTION: This disk clamp mechanism has an iron core 63 provided on a supporting member to which a clamper 5 is attached. A stator substrate 64 having a driving coil 60 whose windings are formed on this iron core 63, a rotor 50 cylindrically formed so that its opening faces a disk 4, and a motor magnet 61 formed on a plane facing the driving coil 60 of this rotor 50 are provided so as to compose a motor. Furthermore, a cone 70 to engage with a center hole of the disk 4 and a guiding member 70a are provided to project from an upper surface of the turn table 7, with an iron plate 80a being buried on an upper surface of this guiding member 70a. A center portion of a pressing piece 52 of the clamper 5 facing the iron plate 80a is integrally molded with this pressing piece 52 by using an anisotropic magnet 52a. In addition, a peripheral portion of the pressing piece 52 is formed using a grip member 90 which grips an upper surface of the disk 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk clamp mechanism of an optical disk reproducing apparatus for recording and reproducing information by rotating a disk medium such as a so-called DVD (digital video disk) at a high speed, and more particularly to a disk clamp mechanism. In the structure of the clamper.

[0002]

2. Description of the Related Art In recent years, such a recording / reproducing apparatus has been used as a CD-RO as a disk medium as a computer auxiliary storage device.
As the demand for M increases, it is required to rotate a CD-ROM at a high speed in order to cope with high-density recording and reproduction of information. The commercial value of CD-ROMs is supported by the speeding up of disk drives, and CD-ROM drives with faster data transfer speeds and access times than ever have been awarded.

In a CD-ROM drive, the rotational speed of the disk is about 200 rpm at the standard speed with respect to the outermost circumference of the disk, and at most about 530 rpm with respect to the innermost circumference of the disk.
pm, and the difference between the inner and outer circumferences of the disk is only about 330 rpm. However, the rotational drive of the disk is one of the standard speed.
At 12x speed, which is doubled, the number of revolutions is at least about 2400
From rpm to a maximum of about 6360 rpm, the difference between the inner and outer circumferences of the disc also increases 12 times.

Further, since the moment of inertia due to the rotation of the disk is the same irrespective of the rotation speed of the disk, if the drive torque of the disk rotation drive motor is constant regardless of the rotation speed of the disk, the adjustment time of the rotation speed, that is, The access time from when the pickup moves between the inner and outer circumferences of the disk and when the rotation speed is set to an appropriate value for reproducing the disk at a predetermined position is 12 times.

However, in general, the drive torque of a disk rotation drive motor decreases as it rotates in a high rotation range, so that the actual access time becomes a value of 12 times or more.
Therefore, in order to shorten the access time of the CD-ROM drive, it is necessary to increase the drive torque of the rotary drive motor.

On the other hand, as shown in FIG. 2, a disk 4 is placed on a turntable 7 for recording and reproduction of a disk.
The turntable 7 is driven to rotate by the motor 2 and pressed by the clamper 5 from above. Generally, a laser beam is irradiated from the lower side of the disk by the pickup 3, and information is read by the reflected beam.

As described above, in order to rotate the disk 4 at a high speed and shorten the access time, it is necessary to increase the diameter of the motor 2 and improve the driving torque. In this case, the motor 2 hinders the movement of the pickup 3 and cannot have such a large diameter.

Accordingly, a motor 6 is provided on the side of the clamper mechanism for rotatably holding the disk 4, and a mechanism for pressing and holding the disk with the clamp mechanism and the turntable to rotate the disk 4 (see Japanese Patent Application Laid-Open No. 63-004642). Has been proposed, for example, as shown in FIG.

In this mechanism, a disk 4 having a hole in the center is rotatably mounted, and a turntable 7 made of a magnetic material and a turntable 7 facing the upper surface of the disk 4 are provided.
And a clamper 5 that presses the disc 4 between them. The clamper 5 is attached to a lower surface of a lid 16 provided to be freely openable and closable with respect to the turntable 7.

The turntable 7 is pressed into a rotating shaft 22 provided rotatably on a chassis 20. The turntable 7 has a cone 70 that becomes thinner toward the tip, and a hole in the center of the disc 4 fits into the cone 70.

The clamper 5 includes a projecting piece 55 supported by supporting pieces 15, 15 projecting from the lower surface of the lid 16, and a supporting piece 1.
A shaft 51 penetrating through the opening 11 between 5 and 15;
And a motor magnet 61 provided at the lower end of the disk 4 and facing the upper surface of the disk 4. At the center of the shaft 51 and the motor magnet 61, a hole 56 that fits into the rotary shaft 22 is formed. At the periphery of the opening 11, a drive coil 60 is provided to face the motor magnet 61.

When the disk 4 is placed on the turntable 7 and recording and reproduction are performed, the lid 16 is lowered, and the hole 56 of the clamper 5 is fitted to the rotary shaft 22. The turntable 7 and the motor magnet 61 attract and hold the disk 4. When the motor magnet 61 comes into contact with the cone 70, the clamper 5 is slightly lifted, and a gap is formed between the projection 55 and the drive coil 60. In this state, when the drive coil 60 is energized, the clamper 5 rotates while pressing the disk 4 by the electromagnetic force generated between the drive coil 60 and the motor magnet 61. That is, the motor magnet 61 is attracted to the turntable 7 and presses and holds the disk 4.
Face-to-face brushless motor 6 with drive coil 60
Is configured.

Further, the applicant has previously proposed a clamper mechanism shown in FIG. 4 (see Japanese Patent Application Laid-Open No. 3-286466).

The clamper mechanism has a support plate 10 provided so as to be able to approach and separate from the disk 4.
The support plate 10 is fitted in the opening 11. A drive coil 60 is attached to the periphery of the opening 11. The clamper 5 integrally includes a motor magnet 61 facing the upper surface of the drive coil 60, a shaft 51 penetrating through the opening 11, and a pressing piece 52 provided at a lower end of the shaft and in contact with the upper surface of the disk 4. The holding piece 52 is provided with a yoke 62 facing the lower surface of the drive coil 60. A sphere 90 is provided on the upper surface of the shaft 51, and the sphere 90 is in contact with the lower surface of the elastic piece 9 that covers the clamper 5.

Disk 4 mounted on turntable 7
On the other hand, when the support plate 10 is lowered, the clamper 5 slightly lifts due to the contact between the pressing piece 52 of the clamper 5 and the disk 4. A gap is created between the drive coil 60 and the motor magnet 61, and the ball 90 contacts the lower surface of the elastic piece 9. The clamper 5 is urged toward the disk 4 by the urging force from the elastic piece 9, and the clamper 5 presses and clamps the disk 4 with the turntable 7. Drive coil 6
0, the yoke 62 and the motor magnet 61
Since the drive coil 60 is located in the magnetic field therebetween, the clamper 5 rotates together with the disk 4.

Further, the applicant has filed Japanese Patent Application No. 8-13817.
No. 0 proposes a clamper mechanism that constitutes the surface facing motor shown in FIGS. 5 and 6 or the circumferential facing motor shown in FIGS. 7 and 8.

FIG. 5 is a partially cutaway view of the clamper 5 and the turntable 7 in a state where the disk 4 is not inserted into the apparatus main body. A rotating shaft 22 is rotatably fitted in a bearing 21 provided on the sub-chassis 20, and a tip end of the rotating shaft 22 is press-fitted into a through hole 71 formed in a central portion of the turntable 7. . From the upper surface of the turntable 7, a cone 70 that fits into the center hole of the disk 4 protrudes, and a magnet 8 is embedded in the upper surface of the cone 70.

The support plate 10 has an opening 11 into which the clamper 5 fits, and a drive coil 60 is attached to the periphery of the opening.

The clamper 5 includes a rotor 50 facing the upper surface of the drive coil 60, a shaft 51 attached to the center of the rotor 50 and passing through the opening 11, and a presser attached to the lower end of the shaft 51. Piece 52. The tip of the shaft body 51 projects below the holding piece 52 and can be fitted into the through hole 71 of the turntable 7. A motor gnet 61 is provided on the lower surface of the rotor 50 so as to face the drive coil 60. When the disk 4 is not inserted into the apparatus main body, the motor magnet 61 and the drive coil 60 are in contact with each other.

First, the drive coil 6 is assembled.
The rotor 50 is placed on the top of the rotor 50, the shaft body 51 and the holding piece 52 are attached from below the rotor 50, and the holding piece 52 is screwed from above the rotor 50 with screws 58, 58.

The lower surface of the holding piece 52 is in contact with the upper surface of the disk 4, and the yoke 6 made of an iron plate is
2 is mounted opposite the lower surface of the drive coil 60.

The drive coil 60 is located in a magnetic field formed between the motor magnet 61 and the yoke 62. The clamper 5 and the drive coil 60 constitute a brushless motor 6 as described later.

At the center of the holding piece 52, the turntable 7
An iron plate 80 made of a magnetic material that is attracted to the magnet 8 is embedded at a position facing the magnet 8 in the inside. The magnet 8 and the iron plate 80 are magnetically independent of the motor 6 constituted by the clamper 5 and the drive coil 60, and do not affect the characteristics of the motor 6 at all. The reason why the magnet 8 and the iron plate 80 are provided at positions corresponding to the center of the disk is to reduce the size of the magnet 8 and the iron plate 80.

FIG. 6 is a view showing a state where the disk 4 is inserted into the apparatus main body. The sub-chassis 20 rotates upward, and the turntable 7 and the clamper 5 are brought together. The clamper 5 is lifted slightly with the lower surface of the holding piece 52 in contact with the upper surface of the disk 4, and a gap is formed between the drive coil 60 and the motor magnet 61. The friction between the drive coil 60 and the motor magnet 61 is released, and the magnet 61 becomes rotatable. Since the vertical distance between the motor magnet 61 and the yoke 62 is constant, the driving torque of the motor 6 is constant even if the gap between the drive coil 60 and the motor magnet 61 varies.

When the magnet 8 approaches the iron plate 80, the magnet 8 and the iron plate 80 are attracted. Due to the suction force, the clamper 5 moves the disk 4 to the turntable 7.
To be urged.

When the drive coil 60 is energized in this state, the clamper 5 and the turntable 7 attracting the clamper 5 rotate. The disc 4 pressed and held between the clamper 5 and the turntable 7 also rotates. Pickup 3
Slides in the radial direction of the disc to perform recording and reproduction.
If the lower surface of the pressing piece 52 is pressed against the turntable 7 at a position away from the center of the disk 4, the surface runout of the disk 4 can be reduced.

As described above, the clamping of the disk 4 is performed by the attraction between the magnet 8 provided separately from the motor 6 and the iron plate 80 as a magnetic material, so that the magnetic characteristics of the motor 6 are not affected. The clamping force can be changed. Further, since the magnet 8 and the iron plate 80 are provided at positions corresponding to the holes at the center of the disk, their diameters are small. Therefore, the rotational moment of inertia caused by the provision of the magnet 8 and the iron plate 80 is small, and does not affect recording and reproduction. The magnet 8 is placed on the clamper 5 side,
0 may be provided on the turntable 7 side.

FIG. 7 and FIG. 8 show a disk clamping mechanism when a circumferentially opposed motor is employed. The configuration of the turntable 7 is the same as that in the case where the surface facing type motor is adopted. The support plate 10 has an opening 1 into which the clamper 5 fits.
1, and a stator substrate 64 is attached so as to cover the periphery of the opening 11. An iron core 63 is provided on the stator substrate 64, and a drive coil 60 is wound around the iron core 63.

The clamper 5 has a cylindrical rotor 50 with an opening facing the disk 4, and is attached to the center of the rotor 50, penetrates through the opening 11 of the support plate 10, and has a lower surface in contact with the upper surface of the disk 4. The holding piece 52 is integrally provided. A motor magnet 61 is provided on the inner peripheral surface of the rotor 50 so as to face the drive coil 60.

The pressing piece 52 has a concave portion 53 formed at the center of the lower surface, and the shaft body 51 projects downward from the center of the upper surface of the concave portion 53. The shaft 51 is provided with a through hole 71 of the turntable 7.
To prevent the clamper 5 and the turntable 7 from being displaced on a horizontal plane. In a position facing the magnet 8 in the turntable 7 in the upper surface of the concave portion 53,
An iron plate 80 to be attracted to the magnet 8 is embedded.

Therefore, when recording / reproducing the disk 4, the turntable 7 rises and the magnet 8 approaches the iron plate 80. The magnet 8 and the iron plate 80 attract each other, and the clamper 5 urges the disc 4 against the turntable 7 by the attraction force.

Incidentally, the above-described motor for rotational driving does not constitute a motor by itself, but only functions as a motor when the disk 4 is inserted and clamped. For this reason, in the motor for rotational drive as described above, improvement of the clamper 5 as a drive source for rotating the disk 4 is required.

That is, the clamper is usually assembled by injection molding a thermoplastic resin such as polycarbonate, for example, and then embedding a magnet in the molded product using an adhesive or the like. However, such a structure in which the magnet is embedded in the clamper requires an expensive magnet as a separate part and has a limitation in workability in terms of improving an assembling work for bonding the magnet.

Since a drive source is provided on the clamper 5 side, the non-slip material of the disk 4 is
When the drive source rotates at an acceleration or a deceleration, the disk 4 cannot follow the rotation fluctuation, and the disk 4 cannot move between the clamper 5 and the clamper 5. Start sliding. The slip of the disk 4 becomes more conspicuous as the rotational difference between the acceleration and deceleration of the drive source increases. Therefore, it has been a problem to effectively grip the joint between the clamper 5 and the disk 4.

[0035]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and in a disk clamp mechanism, a clamper magnetizes only a central portion of the clamper itself necessary for clamping a disk. Eliminates the need for expensive separate magnets and improves workability in assembling the magnets to the clamper. Further, a gripping material is provided at the periphery of the clamper at the junction with the upper surface of the disk to prevent the disk from slipping.

[0036]

In order to solve the above-mentioned problems, a disk clamp mechanism of an optical disk reproducing apparatus according to the present invention comprises: a turntable 7 on which a recording / reproducing disk 4 is rotatably mounted; A disk clamp mechanism that is provided so as to be relatively close to and separate from the turntable and that presses and clamps the disk with the turntable; and the clamper has a motor that rotates the disk. , An iron core 63 is provided on a support member to which the clamper 5 is attached, a stator substrate 64 having a drive coil 60 wound on the iron core 63, and a cylindrical member having an opening facing the disk 4. And a driving coil 6 of the rotor 50
A motor 70 is formed by forming a motor magnet 61 on the surface opposing to the motor 0. On the upper surface of the turntable 7, a cone 70 that fits into the center hole of the disc 4 is provided with a guide member 70.
The iron plate 80a is buried and protrudes from the upper surface of the guide member 70a together with the iron plate 80a. The center of the pressing piece 52 of the clamper 5 facing the iron plate 80a is an anisotropic magnet 52a.
It is characterized in that it is integrally molded into 2.

The holding piece 52 is injection-molded with an anisotropic magnet material using a resin material as a binder, and the central portion thereof is compression-molded in a magnetic field to form an anisotropic magnet 52a. And the magnet material is bound with 6-nylon or 12-nylon.

Further, the pressing piece 52 is constituted by a gripping material 90 for gripping the upper surface of the disk 4 at its peripheral portion, and the gripping material 90 is formed in a ring shape by coating it with a rubber sheet or urethane-based resin. It is characterized by the following.

[0039]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is applied to the disk clamp mechanism of the optical disk reproducing apparatus described in the section of the prior art. It discloses a technique for preventing a disk from slipping with respect to a clamper in a state where a mold motor is incorporated in a disk clamp mechanism.

Hereinafter, an embodiment in which the disk clamp mechanism of the present invention is applied to a circumferentially opposed motor will be described with reference to the drawings.

FIG. 1 is a diagram showing a state in which the disk 4 is clamped by the clamper 5 and showing a positional relationship between the clamper and the turntable.

First, the configuration of the turntable 7 is such that a cone 70 in which the center hole of the disc 4 is fitted is provided on the upper surface thereof, and a guide member 70a for guiding the disc 4 to the cone 70 is provided in the recess of the cone 70. It is fitted into the cone 70 and provided integrally. An iron plate 80a is embedded in the upper surface of the guide member 70a. And these cones 7
0 and the guide member 70a protrude from the center hole of the disk 4.

An opening 11 in which the clamper 5 fits is formed in the support plate 10, and a stator substrate 64 is attached so as to cover the periphery of the opening 11. An iron core 63 is provided on the stator substrate 64, and a drive coil 60 is wound around the iron core 63.

The clamper 5 integrally includes a cylindrical rotor 50 having an opening facing the disk 4 and a pressing piece 52 attached to the center of the rotor 50 and having a lower surface in contact with the disk 4 surface. . A motor magnet 61 is provided on the inner peripheral surface of the rotor 50 so as to face the drive coil 60.

The pressing piece 52 has a concave portion 53 at the center of the lower surface, and the shaft body 51 projects downward from the center of the upper surface of the concave portion 53. The shaft 51 is provided with a through hole 71 of the turntable 7.
To prevent the clamper 5 and the turntable 7 from being displaced on a horizontal plane.

Here, the pressing piece 52 has a central portion facing the iron plate 80a on the guide member 70a, and is formed of an anisotropic magnet 52a. That is, the holding piece 52 is formed by injection molding itself with an anisotropic magnet material, and a resin material such as 6-nylon or 12-nylon is used as a binder of the magnet material. Then, when injection molding the holding piece 52,
In the molding step, the anisotropic magnet 52a is formed by compression molding only the central portion of the pressing piece 52 in a magnetic field.

As a result, the clamping of the disk 4 can be performed without affecting the magnetic characteristics of the motor 6 because the anisotropic magnet 52a molded integrally with the pressing piece 52 and the iron plate 80a attract each other. Obtainable.

Next, a grip member 90 for preventing the disk 4 from slipping with the upper surface of the disk 4 is provided around the pressing piece 52. The grip material 90 is formed in a ring shape around the entire periphery of the pressing piece 52, and a rubber sheet is adhered or coated with a urethane-based resin to strengthen the bonding with the upper surface of the disk 4.

Thus, the disk 4 follows the rotation fluctuation due to the acceleration / deceleration rotation of the motor, and the clamper 5 and the disk 4
The joining force between them can be effectively increased.

The description of the above embodiments is for the purpose of illustrating the present invention and should not be construed as limiting the invention described in the appended claims or reducing the scope thereof. In addition, the configuration of each part of the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made within the technical scope described in the claims.

[0051]

As described above, according to the disc clamping mechanism of the optical disc reproducing apparatus of the present invention, the turntable 7 on which the recording / reproducing disc 4 is rotatably mounted,
A disk clamp mechanism that is provided so as to be relatively close to and separate from the turntable and that presses and clamps the disk with the turntable; and the clamper has a motor that rotates the disk. , An iron core 63 is provided on a support member to which the clamper 5 is attached, a stator substrate 64 having a drive coil 60 wound on the iron core 63, and a cylindrical shape having an opening facing the disk 4. A motor is formed by forming a motor 50 on a surface of the rotor 50 provided on the rotor 50 and facing the drive coil 60 of the rotor 50, and a motor is formed on the upper surface of the turntable 7. A round cone 70 is buried on the upper surface of the guide member 70a together with the guide member 70a so as to protrude therefrom, and holds the clamper 5 facing the iron plate 80a. Anisotropic magnet 52a a central portion of 52
Since the pressing piece 52 is formed integrally with the pressing piece 52, an expensive magnet provided as a disc clamper is not required, and workability in assembling the magnet to the clamper can be improved.

The pressing piece 52 is formed by injection molding an anisotropic magnet material using a resin material as a binder, and the central portion thereof is formed into a compression molded anisotropic magnet 52a in a magnetic field. By simply passing through, molding can be easily performed.

Further, the pressing piece 52 is constituted by a gripping material 90 for gripping the periphery of the pressing piece 52 on the upper surface of the disk 4.
Since the grip material 90 is coated with a rubber sheet or urethane-based resin to form a ring, the disk 4 follows the rotation fluctuation due to the acceleration / deceleration rotation of the motor, and the joining force between the clamper 5 and the disk 4 is reduced. In addition, the disk can be prevented from slipping.

[Brief description of the drawings]

FIG. 1 is a diagram showing a state in which a disk is clamped by a clamper and showing a positional relationship between the clamper and a turntable.

FIG. 2 is a side view of a disk recording / reproducing apparatus in which a normal motor is arranged on a pickup side.

FIG. 3 is a sectional view of a conventional clamper and a turntable.

FIG. 4 is a sectional view of a clamper and a turntable in another conventional example.

FIG. 5 is a diagram showing a positional relationship between a clamper and a turntable in a disk insertion standby state in another conventional surface-facing motor.

FIG. 6 is a diagram showing a positional relationship between a clamper and a turntable at the time of recording and reproducing a disk in another conventional surface-facing motor.

FIG. 7 is a diagram showing a positional relationship between a clamper and a turntable in a disk insertion standby state in another conventional circumferentially opposed motor.

FIG. 8 is a diagram showing a positional relationship between a clamper and a turntable at the time of recording / reproducing a disk in another conventional circumferentially opposed motor.

[Explanation of symbols]

 Reference Signs List 4 disc 5 clamper 6 motor 7 turntable 50 rotor 51 shaft 52 holding member 52a anisotropic magnet 60 drive coil 61 motor magnet 63 iron core 64 stator substrate 70 cone 71 through hole 70a guide member 80a iron plate 90 grip material

Claims (5)

[Claims] 1. A turntable 7 on which a recording / reproducing disk 4 is rotatably mounted, and the turntable 7
And a clamper 5 that is provided so as to be relatively close to and separated from the turntable, and presses and holds the disk 4 with the turntable 7.
The clamper 5 is a disk clamp mechanism having a motor 6 for rotating the disk 4, wherein an iron core 63 is provided on a support member to which the clamper 5 is attached, and a drive coil 60 wound around the iron core 63. And a rotor 50 provided in a cylindrical shape with an opening facing the disk 4 side, and a motor magnet 61 formed on a surface of the rotor 50 facing the drive coil 60 to form a motor. On the upper surface of the turntable 7, a cone 70 which fits into a hole in the center of the disk 4 projects along with a guide member 70a with an iron plate 80a buried in the upper surface of the guide member 70a, and the clamper 5 facing the iron plate 80a. Presser piece 52
The center portion of the disk clamp mechanism of the optical disk reproducing device is characterized in that a central portion thereof is formed integrally with the holding piece 52 by an anisotropic magnet 52a. 2. The anisotropic magnet 5 according to claim 1, wherein said holding piece 52 is injection-molded with an anisotropic magnet material using a resin material as a binder, and a central portion thereof is compression-molded in a magnetic field.
2a. A disk clamp mechanism of an optical disk reproducing apparatus, wherein the disk clamp mechanism is 2a. 3. A disc clamping mechanism for an optical disc reproducing apparatus, wherein the resin material for binding the magnet material according to claim 2 is 6-nylon or 12-nylon. 4. The disc clamping mechanism of an optical disc reproducing apparatus according to claim 1, wherein said pressing piece (52) is constituted by a grip member (90) for gripping an upper surface of said disc (4). 5. A disc clamping mechanism for an optical disc reproducing apparatus, wherein the grip member 90 according to claim 4 is formed in a ring shape coated with a rubber sheet or a urethane-based resin.