JPH10241275A - Disk clamper for optical disk reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize quick accessing by using a driving motor as the circumferential opposing type brushless motor of an inner rotor system for rotating a rotor part in the inner diameter side of a stator and using the rotor part also as a disk clamper. SOLUTION: A plurality of notches parts are provided in the outer peripheral part of the rotor 50 of a circumferential opposing type brushless motor. The rotor 50 rotates and moves the notched parts, gaps between the rotor 50 and an iron core 63 are adjusted to be uniform on the full circumference and thereby the centering of a rotor part during motor assembling. An iron plate 80 made of a magnetic material is buried in a turntable 7. The pressing piece 52 of a clamper 5 is molded together with a rotor magnet 61 and a disk pressing magnet 8. For recording/reproducing a disk 4, the turntable 7 is raised to bring the iron plate 80 close to the magnet 8. The magnet 8 and the iron plate 80 are attracted to each other and, by this attracting force, the disk 4 is pressed to the turntable 7 by the clamper 5.

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. The present invention relates to a disk clamp mechanism in which a rotor portion of a motor for use also serves as a disk 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. 4, the disk 4 is usually placed on a turntable 7 and the turntable 7 is driven to rotate by the motor 2 as shown in FIG.
It is pressed by the clamper 5 from above. Then, a laser beam is radiated from the lower side of the disk by the pickup 3, and the information is read by the reflected beam in general.

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 the turntable 7 made of a magnetic material is opposed to the upper surface of the disk 4 and the disk 4 is held between the turntable 7 and the turntable 7. A clamper 5 for pressing is provided. 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.
The face-to-face brushless motor 6 is configured together with the drive coil 60.

Further, the applicant has previously proposed a clamper mechanism shown in FIG. 6 (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 brushless motor shown in FIGS. 7 and 8 or the circumferentially-facing brushless motor shown in FIGS. 9 and 10.

FIG. 7 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. . A cone 70 that fits into the center hole of the disk 4 protrudes from the upper surface of the turntable 7, and a disk crimping magnet 8 that attracts an iron plate 80 described later 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
In the position facing the disk crimping magnet 8 inside,
An iron plate 80 made of a magnetic material that is attracted to the disk pressing magnet 8 is embedded. The disk pressing magnet 8 and the iron plate 80 include the clamper 5 and the driving coil 6.
0 is magnetically independent of the motor 6 and does not affect the characteristics of the motor 6 at all.
The reason why the disk pressing 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 disk pressing magnet 8 and the iron plate 80.

FIG. 8 is a diagram 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 gap 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 changes.

As the disk pressing magnet 8 approaches the iron plate 80, the disk pressing magnet 8 and the iron plate 8
0 attracts. The clamper 5 urges the disc 4 against the turntable 7 by the suction force.

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 magnetic characteristics of the motor 6 are affected by clamping the disk 4 by attracting the disk pressing magnet 8 provided separately from the motor 6 and the iron plate 80 as a magnetic material. Without changing the clamping force. Further, since the disk pressing magnet 8 and the iron plate 80 are provided at positions corresponding to the holes at the center of the disk, the diameter is small. Accordingly, the rotational inertia moment generated by providing the disk pressing magnet 8 and the iron plate 80 is small, and does not affect the recording / reproducing. The disk pressing magnet 8 may be provided on the clamper 5 side, and the iron plate 80 may be provided on the turntable 7 side.

FIG. 9 and FIG. 10 show a disk clamp mechanism when a circumferentially opposed brushless motor is employed.

The structure of the turntable 7 is the same as that in the case where a surface-facing brushless motor is employed. Support plate 10
An opening 11 into which the clamper 5 fits is opened, 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 having an opening directed toward the disk 4, and is mounted at 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 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 the upper surface of the concave portion 53, an iron plate 80 to be attracted to the disk crimping magnet 8 is embedded at a position facing the disk crimping magnet 8 in the turntable 7.

Therefore, when recording and reproducing the disk 4, the turntable 7 rises, and the disk pressing magnet 8 approaches the iron plate 80. The disk pressing magnet 8 and the iron plate 80 are attracted to each other.
The clamper 5 urges the disc 4 against the turntable 7.

In the above description, it goes without saying that the motor magnet is replaced with a rotor magnet.

[0034]

However, the disk clamp mechanism for driving a disk by forming a motor on the clamper side as described above has no limitation on the motor diameter and has a high torque required for high-speed rotation. Is possible. For this reason, it is desirable that the disk rotation drive motor be a so-called outer rotor type circumferentially opposed brushless motor in which the inner circumferential surface of the rotor magnet faces the outer circumferential surface of the iron core.

However, in the case of an outer rotor type brushless motor, the rotor magnet becomes heavier and the inertia (inertia) increases as the rotor diameter increases. For this reason, making the rotor diameter larger than that of the stator portion is disadvantageous for speeding up the response to acceleration / deceleration of motor rotation, that is, for high-speed access for motor rotation speed control.

In the outer rotor type circumferentially opposed brushless motor, since almost the entire area of the stator is covered with a structure for holding the rotor, a uniform gap is provided between the iron core and the rotor magnet when the motor is assembled. There is a problem that the working efficiency such as the adjusting work and the centering work of the rotor part is low.

Further, the pressing piece is usually formed by injection molding a thermoplastic resin such as polycarbonate, for example, and then inserting the rotor magnet into the pressing piece and performing the turntable 7 operation.
It is common practice to perform an assembling operation or the like in which a magnet is buried in a concave portion of a pressing piece facing the iron plate 80 using an adhesive or the like. However, the mounting structure of the rotor magnet and the disk crimping magnet to such a holding piece is as follows.
In addition to requiring an expensive magnet as a separate part, there is also a problem in workability in terms of improving an assembling work for bonding these magnets.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has an inner rotor type circumferentially opposed brushless motor provided on a clamper side for rotating and clamping a disk to increase the torque of the motor. A disk clamp mechanism that realizes high-speed access while providing the same. Further, the efficiency of assembling work as a disk rotation drive motor when assembling and adjusting the rotor portion to the stator portion is improved. Further, the rotor section improves the work of inserting the rotor magnet into the holding piece and the work of assembling the disk crimping magnet, which is provided facing the magnetic material on the turntable, into the holding piece.

[0039]

In order to solve the above-mentioned problems, according to the present invention, a disk rotation driving motor is an inner rotor type brushless motor of an inner rotor type in which a rotor rotates on the inner diameter side of a stator. Used a clamper to clamp the disc.

The rotor portion is provided with a plurality of notches 50b on the outer peripheral portion of the rotor 50 so that the gap between the outer peripheral edge 61a of the rotor magnet 61 and the inner peripheral edge 63a of the iron core 63 can be visually recognized by the notches. did.

Further, in the rotor portion, the holding piece 52 was integrally molded with the rotor magnet 61 and the disk crimping magnet 8 using a magnet material.

[0042]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is applied to a disk clamp mechanism of an optical disk reproducing apparatus described in the section of the prior art, and a spindle motor for driving a disk rotation by the disk clamp mechanism is used for an optical disk. The motor is arranged above, and this motor constitutes an inner rotor type circumferentially opposed brushless motor whose rotor rotates on the inner diameter side of the stator, enabling high speed access of the disk drive while achieving high torque. In addition, the present invention discloses a technique in which a rotor part also serves as a clamper for clamping a disk.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a partially cutaway view of the clamper and the turntable when the disk is clamped by the disk clamp mechanism.

First, the structure of the turntable 7 is the same as that of the conventional example. The disk clamp mechanism has a support plate 10 provided so as to be able to approach and separate from the disk 4. The clamper 5 is a support member 10 serving as a clamp member that rotatably presses the disk 4 placed on the turntable 7. In the opening 11. The center of the opening 11 is larger than the stator substrate 64, and
Is a holding member for screwing and holding the stator substrate 64 to the disk clamp mechanism.

An annular core 63 made of a magnetic material is disposed on the stator substrate 64 at the periphery of the opening 11. The inner diameter of the core 63 protrudes into the opening 11 and is formed on the stator substrate 64. Smaller than caliber. In addition, iron core 6
A drive coil 60 is wound around 3.

In the clamper 5, a circular flange-shaped rotor 50 having an outer diameter larger than the annular inner diameter of the iron core 63 is provided on the upper surface side of the iron core 63, and the rotor 50 and the opening 11 of the support plate 10 are connected to each other. A pressing piece 52 as a clamp member which penetrates and whose lower surface contacts the upper surface of the disk 4 is integrally provided.

The outer peripheral surface of the rotor 50 has a drive coil 6
A rotor magnet 61 having an outer diameter smaller than the annular inner diameter of the iron core 63 is inserted opposite to 0 (that is, the circumferential surface of the annular inner diameter of the iron core 63).

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 bottom surface of the concave portion 53. The cone 70 of the turntable 7 fits into the recess 53. The shaft body 51 is fitted into the rotation center hole 50a of the rotor 50. The shaft body 51 is fitted into the through hole 71 of the turntable 7, and the clamper 5 and the turntable 7
Prevents displacement on a horizontal plane. Further, in the bottom surface of the concave portion 53, an iron plate 8 made of a magnetic material in the turntable 7 is provided.
A magnet 8 for pressing a disk for adsorbing the iron plate 80 is embedded in a position opposing 0.

When recording / reproducing the disk 4, the turntable 7 rises and the iron plate 80 approaches the disk pressing magnet 8, as in the conventional example. The disk pressing magnet 8 and the iron plate 80 attract each other, and the clamper 5 urges the disk 4 against the turntable 7 by the attraction force.

FIG. 2 is a top view of a circumferentially opposed brushless motor of the inner rotor type.

In the figure, the rotor 50 is provided with a plurality of U-shaped cutouts 50b at its outer peripheral portion, and the cutouts 50b form a gap between the outer peripheral edge 61a of the rotor magnet 61 and the inner peripheral edge 63a of the iron core 63. I can look directly. The notch 50b may be provided in a U-shape as long as the gap can be confirmed. The rotor 50 rotates the notch 50b and uniformly adjusts the gap between the notch 50b and the iron core 63 over the entire circumference, thereby facilitating the centering operation of the rotor portion at the time of assembling the motor. Can be.

Next, another embodiment in which the holding piece 52 of the rotor portion is formed of a magnet material together with the rotor magnet 61 and the disk pressing magnet 8 will be described.

FIG. 3 is a partially cutaway view of the clamper and the turntable in a state where the disk is clamped by the disk clamp mechanism.

In the drawing, an iron plate 80 made of a magnetic material is embedded in the turntable 7 as in the embodiment shown in FIG.

In the clamper 5, the holding piece 52 is formed integrally with the conventional rotor magnet 61 and the disk pressing magnet 8 by an anisotropic magnet. That is, the holding piece 52 is formed by injection molding itself with an anisotropic magnet material,
A resin material such as nylon or 12-nylon is used. When the presser piece 52 is injection-molded, the presser piece 52 is compression-molded in a magnetic field in the molding step to form an anisotropic magnet.

As a result, it is not necessary to prepare expensive magnets such as the rotor magnet 61 and the disk crimping magnet 8 which are conventionally formed as separate parts. In addition, the work of assembling the disk crimping magnet 8 can be omitted.

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 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.

[0059]

As described above, according to the present invention, in a disk clamping mechanism for rotating and clamping the disk 4 by arranging the motor on the clamper side, the rotation driving motor rotates the rotor on the inner diameter side of the stator. Inner rotor type brushless motor of the inner rotor type, and the rotor part also serves as a clamper for clamping the disk 4,
High-speed access can be realized while increasing the torque of the motor.

The rotor portion is provided with a plurality of notches 50b on the outer peripheral portion of the rotor 50 so that the gap between the outer peripheral edge 61a of the rotor magnet 61 and the inner peripheral edge 63a of the iron core 63 can be visually recognized. Therefore, the notch 50b is rotationally moved to uniformly adjust the gap between the notch 50b and the iron core 63 over the entire circumference, so that the motor as a disk rotation driving motor when assembling and adjusting the rotor unit to the stator unit. The workability of the assembling work and the centering work can be easily and improved, and the work efficiency can be improved.

Further, since the holding portion 52 is integrally formed of a magnet material together with the rotor magnet 61 and the disk crimping magnet 8 in the rotor portion, such a part can be formed as one part.
The conventional magnet assembling work can be omitted as the individual pressing pieces 52.

Furthermore, the presser piece 52 simply passes through a general-purpose processing step of injection-molding an anisotropic magnet material using a resin material as a binder and processing it into a compression-molded anisotropic magnet in a magnetic field. Therefore, it is possible to easily perform the shaping process, so that there is a unique effect that it is inexpensive as compared with the cost of parts using the rotor magnet 61 and the disk crimping magnet 8 as in the related art.

[Brief description of the drawings]

FIG. 1 shows a positional relationship between a clamper and a turntable at the time of recording / reproducing a disk in an inner rotor type circumferentially opposed brushless motor in which a rotor portion rotates in a circumferentially opposed manner on the inner diameter side of a stator portion in an embodiment of the present invention. FIG.

FIG. 2 is a diagram of the inner rotor type circumferentially opposed brushless motor of the embodiment as viewed from above.

FIG. 3 is a view showing an inner rotor type circumferentially opposed brushless motor in which a rotor part also serves as a clamper in another embodiment of the present invention.

FIG. 4 is a side view of a disk recording / reproducing apparatus in which a normal motor is arranged on a pickup side.

FIG. 5 is a sectional view of a conventional clamper and a turntable.

FIG. 6 is a sectional view of a clamper and a turntable in another conventional example.

FIG. 7 is a diagram showing a positional relationship between a clamper and a turntable in a disk insertion standby state in another conventional surface-facing brushless motor.

FIG. 8 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 brushless motor.

FIG. 9 is a diagram showing a positional relationship between a clamper and a turntable in a disk insertion standby state in another conventional circumferentially opposed brushless motor.

FIG. 10 is a diagram showing a positional relationship between a clamper and a turntable at the time of recording / reproducing a disk in another conventional example of a circumferentially opposed brushless motor.

[Explanation of symbols]

 Reference Signs List 4 disk 5 clamper 6 motor 7 turntable 8 disk crimping magnet 10 support plate (holding member) 11 opening 50 rotor 50b notch 51 shaft body 52 holding piece 60 drive coil 61 rotor magnet 61a outer peripheral edge (rotor magnet) 63 iron core 63a Inner peripheral edge (iron core) 64 Stator substrate 70 Cone 71 Through hole 80 Iron plate

Claims (5)

[Claims] 1. A clamper is provided at a position above a turntable on which a disk for recording and reproduction is to be mounted,
An optical disc reproducing apparatus that clamps a disc on a turntable by rotating the turntable and drives the disc to rotate, wherein the center of the turntable is opened at a certain height above the turntable, and the center of the disc is screwed to a holding member. A stator portion is formed from the stator substrate thus formed, an iron core formed of an annular magnetic material and having an inner diameter protruding toward the opening side on the stator substrate, and a drive coil wound around the core. A rotor having a diameter larger than the annular inner diameter of the iron core and disposed on the iron core; a pressing piece screwed to a lower surface of the rotor and disposed rotatably and vertically movable; A rotor portion is formed by a rotor magnet having a diameter smaller than the annular inner diameter of the iron core and inserted on the outer peripheral surface of a holding piece facing the iron core. Configure the circumference opposed type motor of inner rotor type rotating at the inner diameter side of the stator portion, the disc clamp mechanism of the optical disk reproducing apparatus in which the rotor unit is characterized in that also serves as a clamper for clamping the disk. 2. The rotor according to claim 1, wherein a plurality of U-shaped or U-shaped notches are provided on an outer peripheral portion of the rotor, and the notches define an outer peripheral edge of a rotor magnet and an inner peripheral edge of an iron core. A disc clamp mechanism for an optical disc reproducing apparatus, wherein a gap between the discs is made visible. 3. A clamper is provided at a position above a turntable on which a disk for recording and reproduction is to be mounted,
An optical disc reproducing apparatus that clamps a disc on a turntable by rotating the turntable and drives the disc to rotate, wherein the center of the turntable is opened at a certain height above the turntable, and the center of the disc is screwed to a holding member. A stator portion is formed from the stator substrate thus formed, an iron core formed of an annular magnetic material and having an inner diameter protruding toward the opening side on the stator substrate, and a drive coil wound around the core. A rotor having a diameter larger than the annular inner diameter of the core and disposed on the core, and a rotor screwed to a lower surface of the rotor and having a diameter smaller than the annular inner diameter of the core; An inner rotor type circumferentially opposed motor in which a rotor portion is formed by a presser piece arranged so as to be movable and vertically movable, wherein the rotor portion rotates on the inner diameter side of the stator portion. Form, disc clamp mechanism of the optical disk reproducing apparatus, characterized in that integrally molded the pressing piece with a magnet material. 4. The anisotropic magnet according to claim 3, wherein the holding piece is injection-molded with an anisotropic magnet material using a resin material as a binder, and compression-molded in a magnetic field. Disc clamp mechanism for optical disc player. 5. A disc clamping mechanism for an optical disc reproducing apparatus, wherein the resin material for binding the magnet material according to claim 4 is 6-nylon or 12-nylon.