JPH05314642A - Information recording and reproducing disk device - Google Patents

Abstract

PURPOSE:To eliminate the need for fixing a magnetic disk after the correction of eccentricity as the magnetic disk is prevented from being deviated by spring force even if the magnetic disk is rotated at a high speed after the correction of the eccentricity. CONSTITUTION:The magnetic disk 3 is fixed by the spring force of a wave washer 8 to a disk-mounting hub 2 fixed to a revolving shaft 1. The magnetic disk 3 is pressed and moved in a diametral direction by a micrometer head 14 after fixing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording / reproducing disk device, and more particularly, to a center of a track of an information recording disk and a rotating shaft in which an apparatus for producing a disk track and a recording / reproducing apparatus having a rotary drive shaft are different. The present invention relates to a device that corrects the eccentricity with respect to the rotation center of.

[0002]

2. Description of the Related Art A conventional technique shown in a sectional view of FIG. 3 will be described below. This structure is based on the latest magnetic recording technology and equipment / equipment editing committee, latest magnetic recording equipment / equipment 19
It is described in 84 general technology publications. The magnetic disk 3 mounted on the disk mounting hub 2 fixed to the tip of the rotary shaft 1 is rotated by the spindle motor 4, and the magnetic head 6 mounted on the actuator 5 records and reproduces information on the magnetic disk 3. The actuator 5 is installed in the case 7 and performs an access and tracking operation by a rectilinear motion or a rotary motion. Rotating shaft 1
The magnetic disk 3 is pressed and fixed by the disk clamp 9 via the spacer 10 to the disk mounting hub 2 fixed to. At this time, the disc clamp 9 is fixed to the disc mounting hub 2 by a mounting screw 11. In this magnetic disk device, since recording / reproducing is consistently performed with the magnetic disk 3 attached to the rotary shaft 1, it is possible to perform recording / reproducing work at the same center of rotation.

[0003]

DISCLOSURE OF THE INVENTION In a magnetic disk, a track pitch is shortened by separating tracks from each other by a groove to reduce magnetic mutual interference between tracks, and a discrete disc that enables high density information recording. There is a medium. In this discrete medium, the recording / reproducing track is formed by a device different from the recording / reproducing device. For this reason,
When the magnetic disk formed on the discrete medium is mounted on the rotary shaft, eccentricity occurs between the circular center of the track and the rotary center of the rotary shaft within the mounting gap between the magnetic disk inner diameter and the disk mounting hub outer diameter. When the disk is rotated at a high speed, the magnetic head must be moved rapidly and largely if the amount of eccentricity is large. This can be dealt with by improving the performance of the magnetic head actuator, but this has a manufacturing upper limit.

For example, assuming that the eccentricity is 30 μm, the track pitch is 3 μm, and the rotation speed of the rotary shaft is 7200 rpm, the required band (frequency) of the actuator for the magnetic head is set.
Is simply calculated as 30 (μm) / 3 (μm) × 120
(7200 rpm / 60 seconds) = 1200 Hz. At present, it is very difficult to manufacture an actuator for a magnetic head capable of a band of 1200 Hz when the moving stroke is 30 μm.

Therefore, it is necessary to correct the eccentricity between the center of rotation and the center of the circle of the track to reduce the required band of the magnetic head actuator. Therefore, to correct the eccentricity, there is a method of moving the magnetic disk in the radial direction within the range of the mounting gap between the magnetic disk and the disk mounting hub to reduce the eccentricity, and then fixing the disk by screwing the disk clamp. is there. However, although the eccentricity amount can be corrected by this method, when the disc clamp is fixed with a screw after the correction work, there is a new problem that the magnetic disc is displaced due to friction between the spacer and the magnetic disc.

[0006]

In order to solve the above problems, it is necessary to improve the correction work method. Therefore, the magnetic disk is clamped to the disk mounting hub mounted on the rotary shaft by an appropriate elastic force, for example, a spring force. After that, the eccentricity is corrected by moving the magnetic disk in the radial direction.

[0007]

When the rotating shaft having the magnetic disk mounted thereon is rotated at a high speed, a frictional force larger than the centrifugal force generated by the imbalance of the mounting gap between the inner diameter of the magnetic disk and the outer diameter of the disk mounting hub can be applied to the magnetic disk. Attach the magnetic disk to the disk mounting hub with a spring. In this case, the force for moving the magnetic disk in the radial direction is made larger than the frictional force between the magnetic disk and the disk mounting hub. Even if a disc or a disc mounting hub having different materials and friction coefficients is used, the spring force can be changed by changing the mounting interval of the spring for pressing the disc. In the present invention, even if the magnetic disk is rotated at a high speed after the eccentricity correction work, the magnetic disk does not shift due to the spring force, so that the work of fixing the magnetic disk after the eccentricity correction becomes unnecessary.

[0008]

FIG. 1 is a sectional view of an embodiment of an information recording / reproducing disk device according to the present invention. In this structure, the magnetic disk 3 is mounted on the disk mounting hub 2 fixed to the tip of the rotary shaft 1, and while the magnetic disk 3 is rotated by the spindle motor 4, the magnetic head 6 mounted on the actuator 5 drives the magnetic disk 3 to move. Information recording / reproduction is performed. The actuator 5 is installed in the case 7 and performs an access and tracking operation by a rectilinear motion or a rotary motion. The magnetic disk 3 formed on the discrete medium is mounted on the disk mounting hub 2 fixed to the tip of the rotary shaft 1 by the spring force of the wave washer 8. The spring force of the wave washer 8 at this time is
It can be changed depending on the distance between the disc clamp 9 and the spacer 10. At this time, the disc clamp 9 is fixed to the disc mounting hub 2 by a mounting screw 11.

While observing the discrete track of the magnetic disk 3 attached by the spring force of the wave washer 8 with the monitor 13 connected to the microscope 12, the rotary shaft 1 is rotated by the spindle motor 4 to move the discrete track to the center of rotation. Find the part with the largest amount of eccentricity. The eccentricity between the circular center of the discrete track and the rotation center of the rotary shaft 1 is corrected by pressing the outer circumference of the magnetic disk 3 at this location with the micrometer head 14 and moving the magnetic disk 3 in the radial direction. In this case, by mounting the micrometer head 14 on the rotary drive unit 15 and connecting it to the remote control 16, the outer circumference of the magnetic disk 3 can be automatically pressed.

The spring force of the wave washer 8 is 2 kgf,
Assuming that the coefficient of friction between the magnetic disk 3 and the disk mounting hub 2 is 0.1, the friction force between the magnetic disk 3 and the disk mounting hub 2 is 0.2 kgf. Friction force is 0.
The magnetic disk 3 can be moved in the radial direction by increasing the maximum pressing force of the micrometer head 14 with respect to 2 kgf. By the way, since the pressing force of the micrometer head used in this embodiment can be up to 2 kgf, it can be sufficiently dealt with. Since the discrete track groove can be manufactured with an amount of eccentricity within 30 μm with respect to the inner diameter of the magnetic disk 3 at present,
This can be corrected by setting the mounting gap between the inner diameter of the magnetic disk 3 and the outer diameter of the disk mounting hub 2 to 30 μm or more.

Here, when the magnetic disk 3 is 3.5 inches and the magnetic disk 3 is rotated at 7200 rpm,
When the centrifugal force of the magnetic disk 3 generated due to the imbalance of the mounting gap of 30 μm between the inner diameter of the magnetic disk 3 and the outer diameter of the disk mounting hub 2 is calculated, it is about 0.05 kgf.
Since the frictional force between the magnetic disk 3 and the disk mounting hub 2 is about 0.2 kgf, it is possible to prevent the magnetic disk 3 from being displaced due to the centrifugal force of 0.05 kgf.

The above structure can be applied to an apparatus in which a plurality of magnetic disks 3 are installed on the rotary shaft 1. As an example of the apparatus, FIG. 2 shows a sectional view of an apparatus in which a plurality of magnetic disks 3 are installed at intervals with respect to the rotating shaft 1. In this structure, information is recorded / reproduced on / from the magnetic disk 3 by a magnetic head 6 mounted on an actuator 5 while rotating a plurality of magnetic disks 3 mounted on a rotary shaft 1 by a spindle motor 4.

The actuator 5 is installed in the case 7, and performs an access and tracking operation by a rectilinear motion or a rotary motion. When installing a plurality of magnetic disks 3 formed on a discrete medium with respect to the rotating shaft 1,
It is necessary to correct the amount of eccentricity between the rotation center and the circular center of the discrete track for each magnetic disk 3.
On the disk mounting hub 2 fixed to the tip of the rotating shaft 1,
The magnetic disk 3 formed on the discrete medium is attached by the spring force of the wave washer 8. The spring force of the wave washer 8 at this time can be changed by the distance between the spacer 10 and the spring retainer 17. At this time, the spring retainer 17 is fixed to the disc mounting hub 2 by the mounting screw 11. While observing the discrete track of the magnetic disk 3 attached by the wave washer 8 with the monitor 13 connected to the microscope 12, the rotary shaft 1 is rotated by the spindle motor 4.
Find the point where the amount of eccentricity of the discrete track with respect to the center of rotation is the largest. The eccentricity between the circular center of the discrete track and the rotation center of the rotary shaft 1 is corrected by pressing the outer circumference of the magnetic disk 3 at this location with the micrometer head 14 and moving the magnetic disk 3 in the radial direction. Micrometer head 14 in this case
Is attached to the rotary drive unit 15 and connected to the remote control 16, the outer circumference of the magnetic disk 3 can be automatically pressed.

After the work of correcting the eccentricity of the discrete track of the magnetic disk 3, the magnetic disk 3 formed on the discrete medium is further attached to the spring retainer 17 on the eccentricity-adjusted disk 3 by the spring force of the wave washer 8. . After that, the eccentricity is corrected as described above. By repeating this operation, it becomes possible to attach a plurality of magnetic disks 3 formed on the discrete medium and correct the eccentricity between the circle center and the rotation center of the discrete track. The topmost magnetic disk 3 among the plurality of magnetic disks 3 is attached by a disk clamp 9 via a wave washer 8 and a spacer 10. At this time, the disc clamp 9 is fixed to the spring retainer 17 by a mounting screw 11. Rotating shaft 1 with a plurality of magnetic disks 3 attached has 7200 rp
Even if the magnetic disks 3 are rotated by m, the wave washers 8 provide a frictional force capable of suppressing the centrifugal force of the magnetic disks 3 caused by the mounting imbalance of the inner diameters of the magnetic disks 3. Absent.

[0015]

According to the present invention, it is possible to reduce the amount of eccentricity between the track center and the rotation center in an information recording disc in which a device for producing tracks such as a discrete medium and a recording / reproducing device are different. Above all, this technique is effective not only for the discrete medium but also for the correction of the eccentricity amount of the magnetic disk having the servo track formed by using the laser.

Since the band of the magnetic head actuator can be reduced by the present invention, the magnetic disk can be rotated at a high speed. Therefore, it becomes possible to record and reproduce a large amount of magnetic information at high speed.

[Brief description of drawings]

FIG. 1 is a sectional view of a disk device showing an embodiment of the present invention for a device having one magnetic disk.

FIG. 2 is a sectional view of a disk device showing an embodiment of the present invention for a device having a plurality of magnetic disks.

FIG. 3 is a sectional view of a conventional magnetic disk device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rotating shaft, 2 ... Disk mounting hub, 3 ... Magnetic disk, 4 ... Spindle motor, 5 ... Actuator, 6 ... Magnetic head, 7 ... Case, 8 ... Wave washer, 9 ... Disk clamp, 10 ... Spacer, 11 ... Mounting screws,
12 ... Microscope, 13 ... Monitor, 14 ... Micrometer head, 15 ... Rotation drive part, 16 ... Remote control.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yoshifumi Matsuda 1-280 Higashi Koikeku, Kokubunji, Tokyo Metropolitan Research Center, Hitachi Ltd. (72) Inventor Akagi kyo 1-280 Higashi Koikeku, Kokubunji, Tokyo Hitachi Ltd. Central research institute

Claims (10)

[Claims] 1. A disk device comprising a disk for recording information which rotates about a rotation axis and a head for recording and reproducing information on the disk, wherein when the disk is attached to the rotation axis, elasticity is provided. An information recording / reproducing disk device characterized by being fixed via force. 2. The disk according to claim 1, wherein when the disk is rotated at a high speed by the rotary shaft, the disk is 10
An information recording / reproducing disk device that is pressed by an elastic force that does not shift with respect to the disk mounting portion even if it is decentered by 0 μm or more. 3. The information recording / reproducing disk device according to claim 1, wherein a spring force is used as an element for generating the elastic force. 4. An information recording / reproducing disk device according to claim 3, wherein the disk can be moved in the radial direction by applying a force in the radial direction to the frictional force of the disk mounted by the spring. 5. The disk according to claim 3, wherein while observing a track on the disk mounted by the spring with a microscope, the disk is slightly moved by means for applying a force from the radial direction, and the center of the rotating shaft and the track are moved. An information recording / reproducing disk device capable of correcting the amount of eccentricity. 6. A disk device comprising a plurality of information recording disks rotating about a rotation axis and a head for recording and reproducing information on the surface of the disk,
An information recording / reproducing disk device, wherein each of the disks is fixed via an elastic force when the disk is attached to the rotating shaft. 7. The disk according to claim 6, wherein when the disk is rotated at a high speed by the rotary shaft,
An information recording / reproducing disk device that is pressed by an elastic force that does not shift to the disk mounting portion even if it is decentered by 0 μm or more. 8. The information recording / reproducing disk device according to claim 6, wherein a spring force is used as an element for generating the elastic force. 9. The information recording / reproducing disk device according to claim 8, wherein a radial force is applied to the frictional force of each of the discs mounted by the spring to move the discs in the radial direction. 10. The disk according to claim 8, while observing each track on the disk mounted by the spring with a microscope, the disk is slightly moved by means for applying a force from the radial direction, and the disk is moved relative to the center of the rotating shaft. An information recording / reproducing disk device capable of correcting the amount of eccentricity of each disk track.