JPH04332974A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To reduce the time required by a magnetic disk of a sector servo system for making writing and readout by preventing the occurrence of a positional deviation after recording servo information. CONSTITUTION:After writing servo information on the uppermost or lowermost magnetic disk surface of a magnetic disk 3 by removing the cover 2 of a magnetic disk device and positioning a magnetic head, another magnetic head 4 is positioned on the basis of the servo information written on the uppermost or lowermost magnetic disk surface while the cover 2 is set on the device and servo information is written on the remaining magnetic disk surface. Therefore, the occurrence of a positional device from recording position caused by the tightening of the cover 2, etc., after recording the servo information can be prevented even when no hole is provided through the cover, etc., for inserting a mirror, etc., for measuring length with a laser beam.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device used as an external storage device for a computer.

0002

2. Description of the Related Art FIG. 5 is a sectional view of a conventional magnetic disk device disclosed in, for example, Japanese Patent Laid-Open No. 2-33781. This magnetic disk device has a base 1 as shown in the figure.
and a cover 2 attached to the base 1. On the base 1, a plurality of magnetic disks 3 are arranged vertically at regular intervals, and a plurality of magnetic heads 4 are provided corresponding to each magnetic disk surface. Further, the plurality of magnetic heads 4 are held by a swing type actuator 5 whose shaft is fixed to the base 1, and the plurality of magnetic disks 3 are held by a spindle whose shaft is fixed at both ends to the base 1 and the cover 2. It is rotatably held by a motor 6. Further, the cover 2 is placed over the magnetic disk 3 and magnetic head 4 mounted on the base 1.

The above magnetic disk device is used as an external storage device for a computer, and in a servo system, one of the plurality of magnetic head surfaces is usually used as a magnetic head surface for reading servo information. By writing positional information (servo information) to this servo information, the magnetic head for reading this servo information is positioned, and other magnetic heads are also positioned, and data can be written and read. The method used will be adopted. However, with this method, when temperature changes cause deformation of the device due to the fastening of dissimilar materials, or the shaft of the actuator that holds the magnetic head or the shaft of the spindle motor that rotates the magnetic disk collapses, etc.
Even if the magnetic head for reading servo information is positioned, the magnetic head for writing and reading data may not be positioned correctly. Therefore, in order to solve this problem, servo information was written in a part of each sector (for example, a fan-shaped area divided into 32 parts of a magnetic disk) on all magnetic disk surfaces, and closed-loop control was performed for all magnetic heads. There is also a sector servo, which is generally called a sector servo.

In these servo systems, a clock head 7 of a servo clock writer is inserted from the side as shown in FIG. A mirror 8 for laser length measurement is attached to the mirror 8, and the swing angle of the actuator 5 is measured by the laser length measurement, thereby positioning the magnetic head 4 and writing servo information while maintaining synchronization. At this time, in the case of sector servo, servo information is written in each sector on all magnetic disk surfaces.

By the way, writing of the servo information as described above is normally performed with the cover 2 removed, and the cover 2 is fastened after writing the servo information. However, after writing the servo information like this, the cover 2
However, when the cover 2 is fastened, the base 1 or the cover 2 may be deformed, or the shaft of the actuator 5 or spindle motor 6 may fall. Even if the other magnetic heads are positioned correctly, a situation may arise in which the other magnetic heads are not positioned correctly. Therefore, writing data,
Each time the magnetic head 4 that performs reading is switched, the magnetic head 4 must be positioned again, which increases the time required to write and read data. Therefore, in the magnetic disk drive shown in FIG. 5, the cover 2 has a hole 11 large enough to insert the laser measurement mirror without affecting the rigidity, and a hole 11 large enough to pass the crosshead 7 through. A hole 12 of a size that does not affect the rigidity is provided so that servo information can be written while the cover 2 is fastened to the base 1. After writing the servo information, the two holes 11 and 12 are I'm trying to block it.

[0006]

[Problem to be Solved by the Invention] In order to write servo information with the cover fastened to the base in a magnetic disk drive using the sect servo method, it is necessary to provide a hole for inserting a laser measurement mirror into the cover as described above. Providing holes for the crosshead to pass through and closing these holes after writing servo information results in poor workability and cannot completely eliminate the intrusion of dust.

[0007] This invention was made to solve these problems, and aims to prevent positional deviation after recording servo information and shorten the time required to write and read data in the sector servo system. It is an object of the present invention to provide a magnetic disk device which is capable of providing a magnetic disk drive and which does not require making holes in the cover.

[0008]

[Means for Solving the Problems] A magnetic disk device according to the present invention writes servo information on one of the magnetic disk surfaces with the cover removed, and uses the written servo information to write the servo information on one of the magnetic disk surfaces with the cover removed. Another magnetic head is positioned to write servo information on the remaining magnetic disk surface. Here, in order to prevent the noise generated when writing servo information from propagating to the magnetic head that is reading the servo information written in advance,
It is preferable to specify the magnetic disk surface on which servo information is written with the cover removed as the uppermost or lowermost surface of the plurality of magnetic disk surfaces.

To write servo information on one of the magnetic disk surfaces with the cover removed, a laser length measuring mirror is mounted on the axis of an actuator that holds the magnetic head, and the magnetic head is positioned by laser length measurement. This can be done by

Furthermore, positioning of the magnetic head with the cover removed is possible by directly controlling the swing angle of the actuator using laser length measurement, but it is also possible to position the pins of the servo track writer using laser length measurement. The actuator may be positioned and the swing position of the actuator may be determined by this pin.

Although servo information can be written using a magnetic head of a magnetic disk device, it is also possible to write servo information using a magnetic head of a servo track writer.

0012

[Operation] In this invention, servo information is written on one of the magnetic disk surfaces with the cover of the magnetic disk drive removed, and this written servo information causes other magnetic heads to be activated with the cover on. The magnetic disk is positioned, and servo information is written on the remaining magnetic disk surface. As a result, the positioning of all magnetic heads is relatively fixed with the cover fastened. Therefore, even if the magnetic head for writing and reading data is switched, there is no need to reposition the magnetic head, and the time for writing and reading data is shortened. Moreover, there is no need to drill holes in the cover.

[0013] Furthermore, by specifying the magnetic disk surface on which servo information is written with the cover removed as the topmost or bottommost surface of a plurality of magnetic disk surfaces, one of the two magnetic heads can be placed between the magnetic disks. When pre-written servo information is read and the other magnetic head writes the servo information, the noise generated when writing the servo information is transferred to the magnetic head that is reading the pre-written servo information. It can prevent it from spreading.

[0014] Servo information can be written with the cover removed by positioning the magnetic head using a laser length measuring mirror mounted on the axis of the actuator that holds the magnetic head. It is also possible to position the pins of the servo track writer by laser length measurement, and use these pins to define the rocking position of the actuator. Furthermore, servo information can also be written using a magnetic head of a servo track writer.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a cross-sectional view showing an embodiment of a magnetic disk drive according to the present invention, and FIG. 2 is a cross-sectional view of the magnetic disk drive with its cover removed. The magnetic disk device of this embodiment basically has the same configuration as the conventional device shown in FIG. 5, and has a cover 2 attached to a base 1.
On the base 1, a plurality of magnetic disks 3 are arranged vertically at regular intervals, and a magnetic head 4 is provided corresponding to each magnetic disk surface. Also,
The plurality of magnetic heads 4 are held by a swing type actuator 5 whose shaft is fixed to the base 1, and the plurality of magnetic disks 3 are held by a spindle motor whose shaft is fixed at both ends to the base 1 and the cover 2. The magnetic disk 3 and the magnetic head 4 are covered by the cover 2.

In the magnetic disk device of this embodiment,
Writing of servo information is performed as follows. That is, first, as shown in FIG. 2, with the cover 2 removed, a mirror 8 for laser length measurement is mounted on the shaft of the actuator 5, and the swing angle of the actuator 5 is controlled by the laser length measurement, and the magnetic head is 4, and the magnetic head 4 writes servo information in a part of each sector (a fan-shaped area obtained by dividing the magnetic disk surface into 32) on one magnetic disk surface of the specified magnetic disk 3. Further, a clock is recorded on the magnetic disk 3 by the clock head 7, and synchronization is achieved when writing servo information. After servo information is written on a specific magnetic disk surface in this way, after covering and fastening the cover 2 as shown in FIG.
The previously written servo information is read out, the magnetic head corresponding to the other magnetic disk surface is positioned, and the servo information is sequentially written to the remaining magnetic disk surfaces while maintaining synchronization.

If the servo information is first written on the top or bottom magnetic disk surface with the cover 2 removed, two magnetic heads will be inserted between the magnetic disks 3 with the cover 2 on. 4. Those who read the pre-written servo information and the noise generated when writing the servo information is reading the pre-written servo information, such as when the other magnetic head writes the servo information. This can prevent the magnetic head from propagating to the magnetic head.

[0018] Even if the servo information is first written on the top or bottom magnetic disk surface as described above, the noise generated when writing the servo information may be read out from the pre-written servo information. If propagation to the magnetic head 4 cannot be completely prevented, it is necessary to provide a ferrite 9 adjacent to the magnetic head 4 as shown in FIG.

Furthermore, in the above embodiment, a mirror is mounted on the shaft of the actuator and the swing angle of the actuator is controlled by laser length measurement to position the magnetic head. As shown, the swing angle of the actuator 5 may be defined by the pin 10 of the servo track writer controlled by laser length measurement, and the magnetic head 4 may be positioned. In this case as well, the same effect as in the above embodiment can be obtained. play.

Further, in the above embodiment, servo information is written in a part of each sector on each magnetic disk surface using the magnetic head 4 of the magnetic disk device, but it is possible to write servo information in a part of each sector on each magnetic disk surface. The servo track writer may be provided with a magnetic head, and the servo information may be written by moving the magnetic head. In this case, the same effects as in the above embodiment can be obtained.

[0021]

As described above, according to the present invention, the positioning of all magnetic heads is relatively fixed when the cover is fastened, so that it is possible to easily record servo information in the case of a sector servo type magnetic disk drive. Later deviations can be avoided, and the time required to write and read from the disc is shortened. Moreover, since no holes are provided in the cover, there is no deterioration in workability and the intrusion of dust can be suppressed as much as possible.

[0022] Furthermore, by first writing the servo information on the top or bottom magnetic disk surface,
It is possible to prevent noise generated when writing servo information on another magnetic disk surface from propagating to the magnetic head that is reading out the previously written servo information.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of a magnetic disk device according to the present invention.

[Fig. 2] A sectional view showing the same embodiment with the cover removed.

[
FIG. 3 is a sectional view showing another embodiment of the magnetic disk device according to the present invention.

FIG. 4 is a top view showing still another embodiment of the magnetic disk device according to the present invention with the cover removed.

[Fig. 5] Cross-sectional view showing a conventional magnetic disk device

[Explanation of symbols]

1 Base 2 Cover 3 Magnetic disk 4 Magnetic head 5 Actuator 6 Spindle motor 7 Clock head 8 Mirror for laser length measurement 10 pin

Claims (8)

[Claims] 1. A magnetic disk device comprising a plurality of magnetic disks and magnetic heads mounted on a base, having servo information on the surfaces of the plurality of magnetic disks, and a cover covering the magnetic disks and magnetic heads. Servo information is written by a magnetic head on one of the plurality of magnetic disk surfaces with the cover removed, and servo information written on the one magnetic disk surface with the cover covered. 1. A magnetic disk device characterized in that another magnetic head is positioned by the servo controller, and servo information is written on the remaining magnetic disk surface. 2. A magnetic disk device comprising a plurality of magnetic disks and magnetic heads mounted on a base, having servo information on the surfaces of the plurality of magnetic disks, and a cover covering the magnetic disks and magnetic heads. Servo information is written by a magnetic head on the top or bottom surface of the plurality of magnetic disk surfaces with the cover removed, and servo information is written on the top or bottom surface with the cover on. A magnetic disk device characterized in that another magnetic head is positioned based on the written servo information, and the servo information is written on the remaining magnetic disk surface. 3. A magnetic disk device comprising a plurality of magnetic disks and magnetic heads mounted on a base, having servo information on the surfaces of the plurality of magnetic disks, and a cover covering the magnetic disks and magnetic heads. With the cover removed, a mirror for laser length measurement is mounted on the axis of the actuator that holds the magnetic head, and the magnetic head is positioned by laser length measurement to measure the surface of the plurality of magnetic disks. Servo information is written on one of the magnetic disks, and with the cover covered, another magnetic head is positioned by the servo information written on the one magnetic disk surface, and servo information is written on the remaining magnetic disk surface. A magnetic disk device characterized by: 4. A magnetic disk device comprising a plurality of magnetic disks and magnetic heads mounted on a base, having servo information on the surfaces of the plurality of magnetic disks, and a cover covering the magnetic disks and magnetic heads. With the cover removed, a mirror for laser length measurement is mounted on the axis of the actuator that holds the magnetic head, and the magnetic head is positioned by laser length measurement to measure the surface of the plurality of magnetic disks. Servo information is written on the top or bottom surface of the disk, and with the cover covered, other magnetic heads are positioned based on the servo information written on the top or bottom surface, and then the magnetic head is placed on the remaining magnetic disk surface. A magnetic disk device characterized in that servo information is written therein. 5. A magnetic disk device comprising a plurality of magnetic disks and magnetic heads mounted on a base, having servo information on the surfaces of the plurality of magnetic disks, and a cover covering the magnetic disks and magnetic heads. With the cover removed, pins of the servo track writer are positioned by laser length measurement, and the pins define the swinging position of an actuator that holds the magnetic head, and the magnetic head is positioned. Then, servo information is written on one of the plurality of magnetic disk surfaces, and with the cover covered, another magnetic head is positioned by the servo information written on the one magnetic disk surface, and the remaining magnetic heads are positioned. A magnetic disk device characterized in that servo information is written on a magnetic disk surface. 6. A magnetic disk device comprising a plurality of magnetic disks and magnetic heads mounted on a base, having servo information on the surfaces of the plurality of magnetic disks, and a cover covering the magnetic disks and magnetic heads. With the cover removed, pins of the servo track writer are positioned by laser length measurement, and the pins define the swinging position of an actuator that holds the magnetic head, and the magnetic head is positioned. Servo information is written on the top or bottom surface of the plurality of magnetic disk surfaces, and with the cover covered, other magnetic heads are positioned using the servo information written on the top or bottom surface. A magnetic disk device characterized in that servo information is written on the remaining magnetic disk surface. 7. A magnetic disk device comprising a plurality of magnetic disks and magnetic heads mounted on a base, having servo information on the surfaces of the plurality of magnetic disks, and a cover covering the magnetic disks and magnetic heads. With the cover removed, servo information is written on one of the plurality of magnetic disk surfaces by a magnetic head of a servo track writer, and with the cover covered, servo information is written on one of the plurality of magnetic disk surfaces. Other magnetic heads are positioned by the written servo information,
A magnetic disk device characterized in that servo information is written to the remaining magnetic disk surface. 8. A magnetic disk device comprising a plurality of magnetic disks and magnetic heads mounted on a base, having servo information on the surfaces of the plurality of magnetic disks, and a cover covering the magnetic disks and magnetic heads. With the cover removed, servo information is written on the top or bottom surface of the plurality of magnetic disk surfaces by a magnetic head of a servo track writer, and with the cover on, the servo information is written on the top or bottom surface of the plurality of magnetic disk surfaces. A magnetic disk device characterized in that another magnetic head is positioned by servo information written on the top surface or the bottom surface, and servo information is written on the remaining magnetic disk surface.