JPH052728A - Formatting method for hard disk device - Google Patents

Abstract

PURPOSE:To operate the formatting operation of a hard disk by a disk drive single body. CONSTITUTION:A multi-gap head is used as a recording and reproducing head 403, only one gap 402 is preliminarily used for a disk outermost periphery, and a track 410 for reference is recorded. This track for reference is subjected to a servo operation while it is reproduced by a gap 401 positioned on the outside, and at the same time formatting is newly introduced by a gap 402 positioned on the inside. The operation is successively repeated toward an inner periphery, and a format writing along the entire disk is completed. Thus, a format writing device can be unnecessitated, and a required time can be shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for formatting a hard disk drive, which writes a format signal by itself.

[0002]

2. Description of the Related Art In a magnetic disk drive having a high track density, position information written on the disk surface is read by a magnetic head and servo is applied in a closed loop to accurately position the magnetic head with respect to a track. A method of radially writing information about a track servo on a recording surface in correspondence with a recording sector, and recording data in a fan-shaped area sandwiched in a portion where the information about this servo is recorded (hereinafter referred to as a servo section) ( Sector servos are often used, especially in small disk drives.

This servo information is recorded using a magnetic head in the disk device manufacturing process. For this purpose, for example, in the drive manufacturing process, while the drive device (actual device) equipped with this disk is placed on the pedestal, the arm equipped with the head is mechanically moved from the outside to make it finely compatible with tracks. Move the position,
The necessary servo information is written on the disk surface according to the movement.

The servo information relating to this position must not only indicate the position in the radial direction of the disk, but also strictly control the position in the direction along the circumference. Otherwise, when the head moves across the track at high speed, the servo signal loses regularity and causes an error.

FIG. 2 shows an example of a conventional format writing method based on this principle. In the figure,
200 is a drive base, 211 is a disk, and 201 is a clock recording / reproducing head, which is supported by an arm 210.
The drive head 204 is supported by an arm 208. A reflection mirror 207 is temporarily fixed on the center of rotation of the arm. 2
Reference numeral 05 is a laser light source, and 206 is a photodetector.

The procedure for writing a servo signal with this configuration is as follows.

(1) A reference clock and a servo signal are written on the outermost periphery of the disk 211 by using a clock signal read / write head 201 while referring to a rotation signal obtained from a rotary encoder incorporated in a spindle motor.

(2) While weakly energizing the voice coil motor 202, by gently pushing the arm 208 with the probe 203,
The magnetic head 204 is positioned slightly inside the track written in (1).

(3) While using the reproduction signal from the clock signal reading / writing head 201 as a reference clock, the signal reading / writing head 204 writes the servo signal over one revolution. (4) The light emitted from the laser light source 205 passes through the reflection mirror 207 and enters the optical sensor 206. If the optical sensor is made of CCD or the like so that the position can be detected, the rotation angle of the reflection mirror, that is, the position of the head 204 can be electrically known. By pushing the probe while electrically feeding back this, the head 204 can be sequentially positioned toward the inner circumference at a constant pitch for formatting.

Currently, most drives write servo information by the same or similar method in principle.

[0011]

In the case of the conventional example, in order to move the head arm from the outside, this work must be performed with the cover of the drive removed.
That is, the work is performed in a clean room.

For this reason, when attempting to mass-produce by this method, (1) Since one drive is mounted on the servo track writer and writing is performed for each track, it takes 10 minutes or more.

(2) A large number of complicated and expensive servo track writers must be prepared. Such a problem occurs. This in turn drives up the drive manufacturing costs.

[0014]

[Means for Solving the Problems] A head having two recording / reproducing gaps arranged at a predetermined distance in the radial direction of the disk is used, which is a track gap or a second gap at an integral multiple pitch. Is formed.
This second gap is connected to a recording / reproducing circuit different from the first gap.

Of the two gaps, the gap located on the outer peripheral side of the disk reproduces the reference clock signal while tracking based on the reference servo signal recorded on the outermost periphery. At this time, a predetermined servo signal and a reference clock signal are written in the gap located on the inner peripheral side of the disk among the two gaps.

A reference track signal is recorded in advance on the outermost circumference of the disk, and a format signal is written on the entire surface of the disk by the following procedure.

(1) Servo is applied while reproducing the reference track in the gap located on the outer peripheral side, and at the same time, a new format signal is written in the gap located on the inner peripheral side.

(2) The head is slightly moved to the inner circumference side, servo is applied while reproducing with the head located on the outer circumference side of the format signal recorded by the above (1), and a new head is located on the inner circumference side. Write the format signal.

(3) The above operation (2) is sequentially repeated in the inner circumferential direction to format the entire surface of the disk.

[0020]

1 is a schematic plan view and a sectional view showing an example of a thin film magnetic head most suitable for the present invention. This head uses alumina as a substrate to form a magnetic circuit and a coil by a sputtering process.

In the drawings, 100 is an alumina substrate, 1
01 and 102 are first and second magnetic poles, 103 and 104 are magnetic paths for the respective magnetic poles, and 105 and 106 are coils for the respective magnetic paths. 107 and 108 are return magnetic poles in each magnetic path. Reference numerals 109 to 112 are coil terminals, which are led to a signal processing circuit. Based on the principle of perpendicular magnetic recording, this head performs recording / reproduction with a recording medium facing the magnetic poles 101, 102. The magnetic path is angled at the tip so that the two magnetic poles can be provided close together. In addition,
This head is based on US Patent 4.860.139. In the figure, reference numeral 113 is referred to as a pad, and the head performs recording / reproducing while contacting the disk in this portion. In this perpendicular magnetic recording system, the "magnetic pole" functions as the recording / reproducing gap described in the specification of the present application.

FIG. 3 is a diagram showing a simplified block diagram showing how the above-mentioned thin film magnetic head is connected to a circuit. The recording / reproducing circuits are independently provided so that the two magnetic poles can simultaneously record and reproduce independently. The servo circuits may be independent or may be shared and switched.

FIGS. 4a and 4b are enlarged views of the disk and the head as viewed from above to show how the format information is sequentially written in the magnetic disk device according to the present invention having the structure shown in FIG. .. 401 is an outer peripheral side gap, and 402 is an inner peripheral side gap. These correspond to the magnetic poles 101 and 102 in FIG.

The procedure of format writing by this head will be described below.

(1) The head 403 is positioned at a predetermined position on the outermost circumference of the disk by using an optical position detecting means. While the disk is rotated three times in this state, the gap 402 is used to write the clock 404 and the “wobble” signal 406 for the servo. The head must be moved slightly in the radial direction to write the "wobble" signal, which can be achieved by moving the entire head by offsetting the optical position detection signal by a predetermined amount. This is illustrated in Figure 4a.

(2) Next, the head is moved to the inner circumference by an amount equivalent to about one track pitch, and the gap 401 is drawn by servo onto the track 404 written using the gap 402. Figure 4b illustrates this. While the disk is rotated three times in this state, the clock signal 405 and the “wobble” signal 407 for servo are written using the gap 402. Writing the "wobble" signal can be accomplished by moving the entire head by applying a predetermined amount of offset set to the position error signal obtained by the gap 401. Hereinafter, such operations are sequentially repeated until the innermost circumference.

The optical position detecting means may be a simple one such as a limit switch.

The gap located on the outer peripheral side reproduces not only the head having these two gaps on a predetermined track but also a reference for forming a format signal for writing at the gap located on the inner peripheral side. It is also used to get the clock.

Generally, it is not easy to arrange the gaps as close as possible to the track interval as in this example unless a thin film head as shown in FIG. 1 is used. FIG. 5 shows a perspective view of a head according to another embodiment of the present invention which is considered there. In the figure, 501 is a slider and 50 is
Reference numerals 2 and 503 are thin film heads, and 504 and 505 are respective magnetic gaps. These are located at a pitch four times the track width. 506 is a suspension that supports the head. The thin film head in this example is of the so-called IBM 3380 type and uses longitudinal magnetic recording, unlike that shown in the example of FIG.

FIG. 6 is a diagram showing an arrangement of format information on the magnetic disk corresponding to the head shown in FIG.
The head 503 is provided with gaps 504 and 505 at an interval four times the track interval.

As a format write procedure, first, the head is positioned at the outermost circumference, and the format signal is recorded on the track 601 by the outer gap 504 and the format signal is recorded on the track 605 by the inner gap 505 (FIG. 6a). reference). Then, the head is positioned on the inner circumference for one track, and the format signal is recorded on the track 602 by the outer gap 504 and the format signal is recorded on the track 606 by the inner gap 505. (See Fig. 6b) When this operation is repeated two more times, the gap 504 is the previously recorded track.
Come on 605. As a result, tracks 603, 604 and 607,
Although 608 are recorded, it is omitted to represent them by figures. Above, to record tracks 601-608,
The head must be positioned by external reference. (Details will be described later) After this, the drive alone,
Servo is applied based on the reproduction signal from the gap 504, and new formatting is performed at the gap 505. By repeating this operation in sequence, the formatting is completed over the entire surface of the disc.

First, in order to position the head four times with respect to the eight tracks 601 to 608, it is not possible to deal with the method of simply giving an offset to the output of the optical sensor as in the previous example, so at least four tracks are required. Across the width of
An optical scale having high resolution or a position detector corresponding to it is prepared. In the worst case, it is also possible to insert a probe from the outside of the drive and push the head to move the head inward by a predetermined amount.

Instead of recording in the gap 504, the tracks 601 to 604 are recorded before the disk is incorporated into the drive, or a head for recording the tracks 601 to 604 is applied from the outside of the drive. There is also.

Alternatively, the gap 504 may be exclusively used for reproduction, and recording on the tracks 601 to 604 may be stopped. The only drawback of this method is that four tracks are no longer used for recording / reproducing data on the outer peripheral portion of the disk (useless). As the means for realizing the multi-gap (or the multi-gap head), the one formed by the thin film process is the most suitable, but the one by the conventional machining can also be carried out. Further, either perpendicular recording or longitudinal recording may be used as the magnetic recording means.

Further, it is usual that the reference track is first recorded on the outermost circumference and then moved to the inner circumference side, but it is also possible to start from the inner circumference side and proceed to the outer circumference side.

[0036]

According to the present invention, once the reference track is recorded on the outer circumference of the disk, the servo signal is written by the write head on the basis of the read head while reproducing the read signal.
The signals of all tracks can be written by the drive alone.
Therefore, the servo track writer may be unnecessary or a very simple one, and the work to be performed in the clean room may be small, which greatly contributes to the improvement of the throughput, the reduction of the assembly time, and the reduction of the manufacturing cost.

[Brief description of drawings]

FIG. 1 is a schematic plan view and a sectional view showing an example of a thin film magnetic head according to the present invention.

FIG. 2 is a diagram showing an example of a conventional format signal writing method.

FIG. 3 is a simplified block diagram showing how a thin film magnetic head is connected to a circuit.

FIG. 4 is an enlarged view of the disk and the head as viewed from above to show how the format information is sequentially written in the magnetic disk device according to the present invention.

FIG. 5 is a perspective view of another embodiment of the present invention.

FIG. 6 is a diagram showing how a servo signal is written by another method according to the present invention.

[Explanation of symbols]

 100 Alumina substrate 101, 102 First and second magnetic poles 103, 104 Magnetic path 105, 106 Coil 107, 108 Return magnetic pole 200 Drive base 200 Disk 201 Clock recording / reproducing head 204 Head 207 Reflecting mirror 205 Laser light source 206 Photodetector 401 Gap on the inner circumference side 402 Gap on the outer circumference side 403 Recording / reproducing head 410 Track for reference

Claims (1)

Claim: What is claimed is: 1. A head having two recording / reproducing gaps arranged at a predetermined interval in the radial direction of the disc is used, and a reference track signal is recorded in advance on the outermost periphery of the disc. A method of formatting a hard disk drive, characterized in that a format signal is written on the entire surface of the disk by the following procedure. (A) Servo is applied while reproducing the format signal in the gap located on the outer circumference side, and at the same time, a new format signal is written in the gap located on the inner circumference side. (B) Move the head slightly inward,
The format signal recorded by is reproduced by the head located on the outer peripheral side, servo is applied, and the format signal is newly written by the head located on the inner peripheral side. (C) The above operation (b) is repeated in order toward the inner circumferential direction to format the entire surface of the disc.