JPH09231675A - Disk driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely perform the centering of a chucking pulley and to attain the miniaturization. SOLUTION: A turntable 6 is fixed to a rotary shaft 16 of a spindle motor 8, and a projecting part 20 for centering the disk 18 is formed at the center of the turntable 6. A recessed part 28 is formed at the center on the lower surface of the chucking pulley 4 and the diameter thereof is made slightly longer than the outside diameter of the projecting part 20. When the disk 18 is mounted on the turntable 6, the disk 18 is arranged on the turntable 6 in the state such as a hole of the center is fitted through the projecting part 20, and the chucking pulley 4 is engaged with the upper end part of the projecting part 20. Since the recessed part 28 of the chucking pulley 4 is fitted to the upper end part of the projecting part at this time, the chucking pulley 4 is mounted on the projecting part 20 without becoming the eccentric state. A magnet 30 of the chucking pulley 4 is attracted to a chucking yoke 26 of the projecting part 20, thus, the disk 18 is fixed to the turntable 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk drive device for rotationally driving a disc-shaped information recording medium.

[0002]

2. Description of the Related Art A disk drive for reading or writing information by accessing a disk-shaped information recording medium such as a CD-ROM (compact disk read only memory) or a magneto-optical disk (hereinafter also referred to as a disk medium or simply a disk). In the device, when the disk vibrates, it becomes difficult to correctly read / write information, or the reproduced music or video becomes deteriorated, for example. Therefore, it is necessary to minimize the vibration of the disc.

The vibration of the disk occurs due to various factors. For example, when the chucking pulley for fixing the disk to the turntable is eccentrically mounted on the turntable, the center of gravity of the whole shifts from the center of the motor rotating shaft. ,
Vibration occurs. Therefore, conventionally, a boss is provided at the center of the chucking pulley to prevent the chucking pulley from being eccentrically mounted on the turntable.

This will be described with reference to FIGS. 7 and 8. FIG. 7 is a side view showing a main part of a conventional CD-ROM drive, and FIG. 8 is a plan view of the same. The CD-ROM drive 102 includes a spindle motor 8 and a turntable 10.
4, a chucking pulley 106 (FIG. 7) and the like. The spindle motor 8 includes a rotor 10 and a stator substrate 12, and the stator substrate is a chassis 146.
It is fixed on the top by mounting screws 14. The chassis 146 is mounted on the CD-R via a rubber insulator 110 for preventing vibration from being transmitted to the disk 18.
It is mounted on the body frame of the OM drive 102.

A turntable 104 is concentrically fixed to the upper end of a rotary shaft 112 of the spindle motor, and a disc 18 is detachably mounted on the turntable 104. A disc mounting reference convex portion 114 (hereinafter, simply referred to as a convex portion 114) having a circular shape in plan view is formed in the center of the turntable 104, and the disc 18 has a circular shape in which the convex portion 114 is formed in the center of the disc 18. It is inserted into the hole and attached.

The chucking pulley 106, which is circular in plan view, has a circular recess 138 at the center of the lower surface thereof.
The convex portion 114 of the turntable 104 is housed in the turntable 104 and the disk 18.

As shown in FIG. 8, a pickup 116 for reading / writing information from / to the disc 18 is mounted on a pickup guide shaft 118 so as to be slidable in the radial direction of the disc 18, and has a sled motor 120.
Is driven via the sled gear 122.

Next, referring to FIGS. 9 and 10, the protrusion 114 of the turntable 104 and the chucking pulley 10 are shown.
6 will be described in more detail. FIG. 9 is a cross-sectional view showing details of the turntable 104, and FIG. 10 is a plan view thereof. The convex portion 114 of the turntable 104 is shown in FIG.
As shown in FIG. 10, the inner cylindrical portion 124 and the outer cylindrical portion 1
26 and a connecting portion 128. The inner cylindrical portion 124 is press-fitted to the rotary shaft 112 of the spindle motor and fixed to the rotary shaft 112. Inner cylindrical portion 124
The inner peripheral portion 130 of the upper end of the chucking pulley 1 is described below.
It is shaped like a mortar to facilitate the insertion of the 06 boss. Further, the tip of the rotating shaft 112 has an inner cylindrical portion 12
It stays in the middle part of 4. Outer cylindrical portion 126
Are arranged concentrically with the inner cylindrical portion 124, and thus concentrically with the rotating shaft 112, and are connected to the inner cylindrical portion 124 by an annular connecting portion 128. The outer diameter of the outer cylindrical portion 126 is slightly smaller than the diameter of the hole 132 formed in the center of the disk 18.

A disk-shaped disc support portion 134 is arranged outside the outer cylindrical portion 126 concentrically with the rotating shaft 112, and is connected to the outer peripheral surface of the outer cylindrical portion 126 at the inner peripheral portion. An annular friction sheet 148 is mounted on the upper surface of the peripheral portion of the disk support portion 134.

An upper surface of the convex portion 114 is formed by an annular chucking yoke 136 which is made of, for example, an iron plate and is arranged perpendicularly to the rotating shaft 112. The chucking yoke 136 is fixed to the upper end of the inner cylindrical portion 124 at the inner peripheral portion. Further, since the upper end inner peripheral portion 130 of the inner cylindrical portion 124 has the mortar shape as described above,
The inner diameter of the chucking yoke 136 is larger than the inner diameter of the inner cylindrical portion 124.

The chucking pulley 106 is substantially disc-shaped, and has a circular recess 138 having a diameter sufficiently larger than the diameter of the convex portion 114 of the turntable 104 in the center of the lower surface as described above. A boss 140 is provided at the center of the depression 138.
The diameter of the boss 140 is slightly smaller than the inner diameter of the inner cylindrical portion 124 of the convex portion 114. An annular magnet 142 is fixed to the inner part of the recess 138 of the chucking pulley 106 so as to surround the boss 140.

The disk 18 has a hole 132 fitted in the outer cylindrical portion 126 of the projection 114, and the lower surface of the turntable 104.
It is placed in contact with the upper friction sheet. In this state, the chucking pulley 106 has a recess 1 on its lower surface.
The upper portion of the convex portion 114 is accommodated in the housing 38 and is arranged on the convex portion 114 and the disk 18. At this time, since the magnet 142 in the recess 138 of the chucking pulley 106 is attracted to the chucking yoke 136, the lower surface 144 around the recess 138 of the chucking pulley 106 has the disk 1.
The upper surface of 8 is pressed downward, and as a result, the disk 18 is sandwiched between the disk support portion 134 of the turntable 104 and the lower surface 144 of the chucking pulley 106 and fixed to the turntable 104.

At this time, the chucking pulley 10
Since the boss 140 of No. 6 is inserted into the inner cylindrical portion 124 of the convex portion 114, the chucking pulley 106 is correctly mounted on the turntable 104 without being eccentric.

[0014]

However, in such a conventional centering method for the chucking pulley 106, since the boss 140 is provided at the center of the chucking pulley 106, the area of the magnet 142 must be reduced by that amount. In addition, as a result of making the upper end inner peripheral portion 130 of the inner cylindrical portion 124 into a mortar shape to facilitate the insertion of the boss 140, the inner diameter of the chucking yoke 136 increases and the area of the chucking yoke 136 also decreases. There must be. Therefore, the attraction force of the chucking pulley 106 with respect to the chucking yoke 136 is reduced, and the force for pressing and fixing the disc 18 to the turntable 104 is reduced.

Further, since the boss 140 is inserted into the inner cylindrical portion 124 of the convex portion 114, the rotary shaft 112 of the spindle motor can be inserted only up to the middle of the inner cylindrical portion 124, and as a result, the turntable 104 is inserted. Rotating shaft 112
The adhesion force to In order to avoid this, when the inner cylindrical portion 124 is lengthened, the turntable 10
4 becomes higher, which is disadvantageous in reducing the size and thickness of the device.

In order to fix the boss 140 to the chucking pulley 106 with a required strength, the upper surface of the chucking pulley 106 must have a sufficient thickness,
As a result, the chucking pulley 106 becomes thick, which is disadvantageous in reducing the size and thickness of the device.

Further, since the number of parts is increased by one by providing the boss 140, the parts cost and the assembling cost are increased, and further the assembling time is lengthened, so that the production surplus is reduced. SUMMARY OF THE INVENTION It is an object of the present invention to provide a disk drive device capable of reliably centering a chucking pulley and being advantageous in reducing the size and cost of the device.

[0018]

To achieve the above object, the present invention is fixed to a motor and a rotary shaft of the motor,
A turntable on which a disc-shaped information recording medium is mounted,
A chucking pulley for fixing the information recording medium to the turntable, wherein the turntable has a convex portion at the center for positioning the information recording medium by inserting it into a hole at the center of the information recording medium, A chucking pulley is a disk drive that engages the convex portion of the turntable with the information recording medium sandwiched between the chucking pulley and the turntable. It is characterized in that it has a concave portion that fits into the convex portion of the table, and the diameter of the concave portion is slightly larger than the diameter of the convex portion of the turntable.

When mounting the information recording medium on the turntable, first, the information recording medium is placed on the turntable with the central hole inserted in the convex portion of the turntable, and then the chucking pulley is convex. And the disk is fixed to the turntable by engaging the parts. At that time, the chucking pulley has a concave portion on the lower surface, and its diameter is slightly larger than the diameter of the convex portion of the turntable, so that the concave portion fits into the convex portion, and the chucking pulley is attached to the turntable without eccentricity. It is installed.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional side view showing in detail the periphery of a turntable which constitutes a CD-ROM drive which is an example of a disk drive device according to the present invention, and FIG. 2 is a plan view of the same. The conventional C shown in FIGS.
The same components as those of the D-ROM drive are designated by the same reference numerals. Further, since the pickup and its driving mechanism are the same as the conventional ones, the description thereof will be omitted here.

As shown in FIGS. 1 and 2, the CD-ROM drive 2 according to the present embodiment has the same structure as the conventional CD-ROM drive except for the chucking pulley 4 and a part of the turntable 6. It is the same. Therefore, the spindle motor 8 is composed of the rotor 10 and the stator substrate 12 as in the conventional case, and the stator substrate 12 is fixed to the chassis (not shown) by the mounting screws 14. Like the conventional CD-ROM drive described above, the chassis is attached to the frame of the drive body via an insulator (not shown) that reduces the transmission of vibration.

A turntable 6 made of synthetic resin is concentrically fixed to the upper end of the rotary shaft 16 of the spindle motor 8.
The disc 18 is detachably mounted on the turntable 6. In the center of the turntable 6, a disk mounting reference convex portion 20 (that is, a convex portion 20) having a circular shape in plan view is provided.
The disc 18 is mounted on the turntable 6 after the protrusion 20 is inserted into a circular hole formed in the center of the disc 18 for alignment.

The turntable 6 is different from that shown in FIGS. 9 and 10 in the structure of the convex portion 20, particularly the structure of the tip portion of the convex portion. In the present embodiment, the boss is not used for aligning the chucking pulley 4, so that the protrusion 2
The upper end inner peripheral portion 24 of the inner cylindrical portion 22 forming 0 is not formed in a mortar shape as in the conventional case. Therefore, the annular chucking yoke 26 made of a ferromagnetic material attached to the upper surface of the convex portion 20 has an inner diameter smaller than that of the conventional chucking yoke, and thus has a larger area. Further, since the boss is not inserted into the inner cylindrical portion 22, the rotation shaft 16 of the spindle motor 8 is longer than in the conventional case.

The chucking pulley 4 of the present embodiment has a convex portion 2 of the turntable 6 at the center of the lower surface thereof.
It has a recess 28 that is circular in plan view and that fits into the recess 0.
The diameter of 8 is slightly larger than the diameter of the convex portion 20 of the turntable 6. The main body of the chucking pulley 4 is made of synthetic resin in this embodiment.

A disk-shaped magnet 30 attracted to a chucking yoke 26 mounted on the convex portion 20 of the turntable 6 is arranged in the inner portion of the concave portion 28 with its disc surface orthogonal to the center line of the chucking pulley 4. It is arranged. The lower surface of the magnet 30 is a wall surface 30A at the back of the recess 28, and this wall surface and the lower surface 4A of the chucking pulley 4 are provided.
And the depth of the recess 28 is
8 is arranged on the turntable 6 and is sufficiently longer than the distance from the upper surface 18A of the disk 18 to the upper surface 26A of the convex portion 20 when the chucking pulley 4 is engaged with the convex portion 20. Therefore, when the chucking pulley 4 is mounted with the disc 18 interposed therebetween, a gap is formed between the upper surface 26A of the convex portion 20 and the wall surface 30A.

A disk-shaped synthetic resin yoke 32 is provided on the upper surface of the magnet 30 to protect the magnet 30.

In the CD-ROM drive 2 thus constructed, when the disk 18 is mounted, first, the chucking pulley 4 is removed from the convex portion 20 of the turntable 6, and the center of the disk 18 is first set. The disk 18 is placed on the turntable 6 so that the projection 20 is inserted into the hole of the chucking pulley 4
The concave portion 28 on the lower surface of the turntable 6
To the convex portion 20. Here, since the diameter of the concave portion 28 of the chucking pulley 4 is slightly larger than the diameter of the convex portion 20, the chucking pulley 4 is fitted into the convex portion 20 so that the chucking pulley 4 has the convex portion 20. Correctly aligned with respect to the convex portion 20 without eccentricity.
Attached to.

Then, the magnet 30 of the chucking pulley 4 is attracted to the chucking yoke 26 of the convex portion 20,
As a result, the lower surface of the chucking pulley 4 has the disk 18
The upper surface 18A is pressed downward. As a result, the disc 18 is fixed to the turntable 6 by being sandwiched between the chucking pulley 4 and the turntable 6 in a state where the lower surface of the disc 18 is in contact with the friction sheet 6A on the turntable 6.

As described above, the CD-ROM of the present embodiment example
In the drive 2, since the boss is not provided in the center of the chucking pulley 4 as in the conventional case, the magnet 3 is correspondingly provided.
The area of 0 expands. Further, since it is not necessary to increase the inner diameter of the chucking yoke 26 to facilitate the insertion of the boss, the area of the chucking yoke 26 can be increased. Therefore, the attraction force of the chucking pulley 4 to the chucking yoke 26 becomes strong, and the disc 18 can be pressed and fixed to the turntable 6 with sufficient force.

Further, since the boss is not inserted into the inner cylindrical portion 22 of the convex portion 20 of the turntable 6, the rotary shaft 16 of the spindle motor 8 can be inserted up to a position near the upper end of the inner cylindrical portion 22, and the turntable 6 The fixing force with respect to the rotating shaft 16 can be increased. Therefore, it is not necessary to lengthen the inner cylindrical portion 22 in order to compensate for the decrease in the fixing force as in the conventional case, which is advantageous for downsizing and thinning of the device.

Since it is not necessary to attach a boss, it is not necessary to reinforce the upper part of the chucking pulley 4, and as a result, the chucking pulley 4 can be made thin, which is advantageous for downsizing and thinning of the device. . Further, since the number of parts is reduced by one by removing the boss, the parts cost and the assembly cost are reduced, and the assembly time can be shortened, which is effective in improving the production capacity.

Next, a second embodiment of the present invention will be described with reference to the sectional side view of FIG. 3 and the plan view of FIG. In this CD-ROM drive 34, the structure of the turntable 36, particularly the structure of the convex portion 38, is different from that of the above-described embodiment. The convex portion 38 includes a base portion 40 and an upper end portion 42, and the diameter of the base portion 40 is the same as the diameter of the convex portion 20.
The value is slightly smaller than the hole diameter of the mounted disk 18. The upper end 42 formed on the base 40 is
The structure is basically the same as the upper portion of the convex portion 20, but the diameter is different and is smaller than the diameter of the convex portion 20 and thus the diameter of the base portion 40.

The chucking pulley 44 is adapted to the concave portion 7 in conformity with the small diameter of the upper end portion 42 of the convex portion 38.
The diameter of 8 is small, and is slightly larger than the diameter of the upper end portion 42. In addition, the peripheral portion 48 of the lower surface 46
A shallow recess 80 is formed continuously in the circumferential direction between the edge and the edge 50 of the recess 78.

Even in the case of such a configuration, the disk 18
When the chucking pulley 44 is mounted on the turntable 36, the concave portion 78 of the chucking pulley 44 is formed on the convex portion 3 of the turntable 36.
The disk 18 can be fixed by engaging with the convex portion 38 without eccentricity by fitting it to the upper end portion 42 of 8.

At this time, since the recess 80 is formed in the lower surface 46 of the chucking pulley 44, the edge 50 of the recess 78 does not contact the shoulder 52 of the base 40, and the chucking pulley 44 is properly turned. It is attached to 36.

Next, a third embodiment of the present invention will be described with reference to the sectional side view of FIG. 5 and the plan view of FIG. In this CD-ROM drive 54, the structure of the turntable 56, especially the structure of the convex portion 58 is different from that of the above-described embodiment. The convex portion 58 includes a base portion 60 and an upper end portion 62, and the base portion 60 has a centering mechanism for the disk 18. The base 60 includes a cylindrical portion 64 and a ring 6.
6, a coil spring 68 and the like.
The cylindrical portion 64 is formed in the center of the turntable 6 and is press-fitted to the rotary shaft 16 of the spindle motor 8. A coil spring 68 is fitted on the cylindrical portion 64, and a ring 66 is fitted on the coil spring 68.

The inner diameter of the ring 66 is slightly larger than the outer diameter of the cylindrical portion 64, and there is no play, and the inner peripheral surface of the ring 66 slides on the outer peripheral surface of the cylindrical portion 64 to allow the ring 66 to move up and down. It is formed with such dimensions. The outer peripheral surface of the ring 66 is conically inclined, so that the outer diameter of the ring 66 is smallest at the upper surface 70 and largest at the lower surface 72. The outer diameter of the intermediate portion between the upper surface 70 and the lower surface 72 is substantially equal to the diameter of the hole of the disk 18 to be mounted.

On the lower surface of the ring 66, there is formed a circular groove 74 which is continuous in the circumferential direction and which is circular in plan view.
The upper portion of the coil spring 68 is inserted into the coil 4.
The upper end of the coil spring 68 is in contact with the inner part of the groove 74 and biases the ring 66 upward.

The upper end 62 of the protrusion 58 is formed by a chucking yoke 82. Chucking yoke 8
2 is made of a ferromagnetic material such as an iron plate, has a circular shape in plan view, and is fixed to the upper end of the cylindrical portion 64. The entire periphery of the chucking yoke 82 bends downward, and the rotating shaft 1
A side surface 76 parallel to 6 is formed. The outer diameter of the chucking yoke 82 is determined by the side surface 76, and the ring 66
Is smaller than the outer diameter of.

The chucking pulley 84 has basically the same structure as the chucking pulley 44, but the diameter of the recess 86 is slightly larger than the outer diameter of the chucking yoke 82. In this embodiment, when the disc 18 is mounted on the turntable 56, the disc 1
The outer peripheral surface of the ring 66 is pressed by the edges of the holes 8 so that the ring 66 moves up and down. Therefore, even if there is a slight variation in the hole diameter of the disk 18, the variation will be
6 is moved up and down to be absorbed, and the disk 18 is prevented from being mounted on the turntable 56 in an eccentric state.

When the chucking pulley 84 is mounted, the concave portion 86 of the chucking pulley 84 is replaced by the convex portion 58 of the turntable 56.
The disk 18 can be fixed by engaging with the convex portion 58 without eccentricity by being fitted to the upper end portion 62 composed of the chucking yoke 82.

In the above embodiment, the disk drive device is the CD-ROM drive, but this is merely an example, and other than the CD-ROM drive, the present invention is a CD (compact disk) player. , C
D-R (write-once type optical disk) recorder, MD (mini disk) drive, MO (magneto-optical disk) drive, H
It can be applied to a D (hard disk) drive, an LD (laser disk) player, and the like.

[0043]

As described above, according to the present invention, the motor, the turntable fixed to the rotary shaft of the motor and having the disk-shaped information recording medium mounted thereon, and the information recording medium fixed to the turntable. And a chucking pulley for positioning the information recording medium in the center of the turntable by inserting the chucking pulley into the hole at the center of the information recording medium. In a disk drive device for engaging the convex portion of the turntable with the information recording medium sandwiched therebetween, the chucking pulley has a concave portion at the center of the lower surface thereof, which is fitted to the convex portion of the turntable. The diameter of the concave portion is slightly larger than the diameter of the convex portion of the turntable.

Therefore, in the disk drive device of the present invention,
Since no boss is provided in the center of the chucking pulley as in the conventional case, the area of the magnet is increased accordingly. Further, since it is not necessary to increase the inner diameter of the chucking yoke in order to facilitate the insertion of the boss, the area of the chucking yoke can be increased. Therefore, the attraction force of the chucking pulley with respect to the chucking yoke becomes strong, and the disc can be pressed and fixed to the turntable with sufficient force.

Further, since the boss is not inserted in the hole for inserting the rotary shaft of the motor in the convex portion of the turntable, the rotary shaft of the spindle motor can be inserted up to a position close to the upper end of the convex portion, and is fixed to the rotary shaft of the turntable. You can improve your wearing power. Therefore, it is not necessary to elevate the convex portion in order to compensate for the decrease in the fixing force as in the conventional case, which is advantageous for downsizing and thinning of the device.

Since it is not necessary to attach a boss, it is not necessary to strengthen the upper part of the chucking pulley, and as a result, the chucking pulley can be made thin.
This is advantageous for downsizing and thinning the device. Further, since the number of parts is reduced by one by removing the boss, the parts cost and the assembly cost are reduced, and the assembly time can be shortened, which is effective in improving the production capacity.

[Brief description of drawings]

FIG. 1 is a CD- which is an example of a disk drive device of the present invention.
It is a cross-sectional side view which shows the turntable periphery which comprises a ROM drive.

FIG. 2 is a plan view showing the periphery of the turntable shown in FIG.

FIG. 3 is a sectional side view showing the periphery of a turntable of a CD-ROM drive according to a second embodiment.

FIG. 4 is a plan view showing the periphery of the turntable shown in FIG.

FIG. 5 is a cross-sectional side view showing the periphery of a turntable of a CD-ROM drive according to a third embodiment.

FIG. 6 is a plan view showing the periphery of the turntable shown in FIG.

FIG. 7 is a side view showing a main part of a conventional CD-ROM drive.

FIG. 8 is a plan view showing a main part of the CD-ROM drive of FIG.

9 is a sectional side view showing the periphery of a turntable of the CD-ROM drive of FIG.

FIG. 10 is a plan view showing the periphery of a turntable of the CD-ROM drive of FIG.

[Explanation of symbols]

2, 34, 54 ... CD-ROM drive, 4, 44,
84 ... Chucking pulley, 6, 36, 56 ... Turntable, 8 ... Spindle motor, 10 ... Rotor, 12 ... Stator substrate, 16 ... Rotating shaft, 18 ...
Disc, 20, 38, 58 ... Disc mounting reference convex portion (convex portion), 22 ... Inner cylindrical portion, 26, 82 ... Chucking yoke, 28, 78, 86 ... Recessed portion, 30 ...
… Magnet, 32 …… York, 40, 60 …… Base,
42, 62 ... upper end portion, 64 ... cylindrical portion, 66 ... ring, 68 ... coil spring

Claims (7)

[Claims] 1. A motor, a turntable fixed to a rotary shaft of the motor and having a disk-shaped information recording medium mounted thereon, and a chucking pulley for fixing the information recording medium to the turntable. The turntable has a convex portion at the center for positioning the information recording medium by inserting it into the hole at the center of the information recording medium, and the chucking pulley sandwiches the information recording medium with the turntable. In the state, in the disk drive device that engages with the convex portion of the turntable, the chucking pulley has a concave portion at the center of the lower surface thereof that fits into the convex portion of the turntable, and the diameter of the concave portion is A disk drive device, which is slightly larger than the diameter of the convex portion of the turntable. 2. The turntable includes a base portion for positioning the information recording medium and an upper end portion, the upper end portion having a diameter smaller than that of the base portion, and the concave portion of the chucking pulley. The disk drive device according to claim 1, wherein a diameter is slightly larger than a diameter of the upper end portion of the turntable convex portion. 3. The base of the turntable protrusion is
The ring includes a ring and a spring, the ring is arranged concentrically with the rotation axis of the motor so as to be movable along the rotation axis, has an outer peripheral surface inclined in a conical shape, and has an intermediate position between an upper end and a lower end. An outer diameter at a position is substantially equal to a diameter of the hole of the information recording medium, the spring is arranged below the ring, and urges the ring upward.
The disk drive as described. 4. The disk drive device according to claim 1, wherein the protrusion is made of synthetic resin. 5. The disk drive device according to claim 1, wherein the chucking pulley is made of synthetic resin. 6. The disk drive device according to claim 1, wherein a tip of the convex portion is made of a ferromagnetic material, and the chucking pulley has a magnet mounted in the concave portion. 7. A CD player, a CD-ROM drive,
CD-R recorder, MD drive, MO drive, HD
A drive or an LD player, which constitutes either one.
The disk drive as described.