JPH09219075A - Servo pattern forming method for magnetic disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a servo pattern forming method for a magnetic disk capable of writing servo pattern onto to one parts of respective tracks different in track pitch without exchanging a writing head by using a single servo track writer. SOLUTION: This magnetic disk is provided with a read/write area and a read-only area independently, and the width of the track pitch Tpn of the read-only area is formed so as to be narrower than the width of the track pitch Tps of the read/write area. At the time of forming servo patterns 7, 8 by using the servo track writer on the magnetic disk in which the servo tracks 7, 8 are written in one parts of respective tracks of the read/write area and the read-only area, a servo pattern 8 is formed by the writing of one time with respect to the track of the read-only area. Moreover, a servo pattern 7 is formed through the writing of a second time by shifting the writing to the radial direction of the magnetic disk after the writing of a first time with respect to the track of the read/write area.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a servo pattern on a magnetic disk, and more particularly to a servo track writer of one type when two tracks having different track pitches are formed on the magnetic disk. Used,
The present invention relates to a method for forming a servo pattern of a magnetic disk in which two servo patterns having different widths are written on two tracks.

[0002]

2. Description of the Related Art Generally, in a magnetic disk such as a floppy disk or a hard disk (hereinafter, simply referred to as a disk), a large number of tracks are concentrically formed over almost the entire information recordable area of the disk.
The distance between the center line of one track (track center) and the center line of the adjacent track (track center),
The so-called track pitch Tp is usually constant regardless of the inner circumference and the outer circumference of the disk, and various kinds of information such as data is written along these tracks.

By the way, in such a disc, since a large amount of information is processed by using one disc without replacing the disc, as much information as possible is stored without changing the physical size of the disc. There is a demand for a disc that can be written, that is, has a large information storage capacity.

In this case, since the information storage capacity of the disk depends on the number of tracks formed on the disk, the larger the number of tracks formed on the disk, the more
The information storage capacity of the disk increases. Therefore, in such a disc, the number of tracks formed on the disc is increased. However, when the number of tracks is increased, the track pitch Tp is inevitably narrowed, and information is written in the track or information from the track is written. At the time of reading, it becomes impossible to accurately write information to the track.

In order to improve this point, the information recording area of the disc is divided into an outer peripheral portion and an inner peripheral portion, and one area (outer peripheral portion) is formed with a narrow track pitch Tpn. Read-only area and other 1
One area (inner peripheral portion) is a read / write area in which tracks are formed with a relatively wide (standard) track pitch Tps, that is, track pitch T
A disk (hereinafter referred to as an improved disk) has been developed in which a track having a narrower pn is formed and the number of tracks is increased thereby, so that the information recording capacity is increased.

In such an improved disc, information is already written on the improved disc in the read-only area before shipment of the improved disc, and when the user uses the improved disc, only the information is read out. The read / write area is an area in which no information is written on the improved disk before shipment of the improved disk, and desired information can be written and read when the user uses it. Area.

In addition, such an improved disc is irrespective of whether the disc type is a hard disk or a floppy disc, and before the improved disc is shipped, it is recorded on one track of each of the read-only area and the read / write area. Servo patterns are written in some parts to guide the head to a desired track position, that is, to correct the tracking error of the head.
The writing of the servo pattern on the improved disk is usually performed by a servo track writer before shipping the improved disk.

[0008]

The known improved disk described above has a track pitch Tpn in the read-only area.
And the track pitch Tps in the read / write area
Are different, the full width of the servo pattern written in a part of the track of the read-only area and the full width of the servo pattern written in a part of the track of the read / write area are naturally different. .

This means that when a servo track writer is used to write a servo pattern before shipping the improved disc, the servo track writer that writes the servo pattern to a part of the track in the read-only area is Since the write head gap has a structure corresponding to a narrow track pitch Tpn, the servo track writer is used as a servo track writer for writing a servo pattern in a part of the track of the read / write area. I can't.
Similarly, a servo track writer that writes a servo pattern in a part of a track in the read / write area has a structure in which the gap part of the write head corresponds to a relatively wide track pitch Tps, and therefore the servo of that servo This means that the track writer cannot be used as a servo track writer that writes a servo pattern on a part of the track in the read-only area.

As described above, the writing of the servo pattern on the known improved disk is not only necessary to use a single servo track writer, but two servo track writers having different write head gaps are prepared and read only. When writing a servo pattern in the area and the read / write area, the servo track writer has to be appropriately exchanged, so that there is a problem that it takes time to write the servo pattern and the cost becomes high.

However, if only writing is performed using a single servo track writer, a servo track writer with an interchangeable write head is used to write servo patterns in the read-only area and the read / write area, respectively. Two write heads having different gap portions may be used by appropriately exchanging them, but in this case as well, the problem that the writing of the servo pattern is troublesome and the cost is slightly increased remains.

The present invention solves the above-mentioned problems.
An object of the present invention is to provide a method for forming a servo pattern of a magnetic disk, which uses a single servo track writer and enables the writing of a servo pattern in a part of each track having different track pitches without replacing the write head. Especially.

[0013]

In order to achieve the above object,
A read / write area and a read-only area which are independent of each other, and the track pitch of the read-only area is formed narrower than the track pitch of the read / write area;
In addition, the method of forming a servo pattern of the present invention for a magnetic disk in which servo patterns are respectively written in a track of the read / write area and a part of the track of the read-only area is a servo track writer using a servo track writer as described above. When forming the pattern,
For a track with a narrow track pitch in the read-only area, a predetermined servo pattern is formed by writing once to form a track with a standard wide (relatively wide) track pitch in the read / write area. On the other hand, after forming the first servo pattern by the first writing, the second servo pattern by the second writing shifted in the radial direction of the magnetic disk is overwritten on the first servo pattern, Means for forming a predetermined servo pattern are provided.

Further, as the servo track writer in such means, one having a write head having a head gap adapted to a narrow track pitch of the read-only area is used.

According to the above means, when a servo track writer is used to write a servo pattern on each track having a different track pitch, only a single servo track writer is used and a write head is used. Since it can be performed without replacement, it does not take much time to write the servo pattern, and the servo pattern can be written at low cost.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a servo pattern forming method for a magnetic disk according to the present invention is as follows.

First, the magnetic disk of the present invention has a read / write area (usually provided in the inner peripheral area of the disk) and a read-only area (usually provided in the outer peripheral area of the disk) which are independent of each other. The track pitch of the tracks formed in the read-only area, that is, the interval between the center line of one track (track center) and the center line of the adjacent track (track center) is narrowed. , The track pitch of the tracks formed in the read / write area is standardly wide (relatively wide), and
A magnetic disk of the type in which servo patterns are written in a part of the tracks of the read / write area and the track of the read-only area, and a typical example is a high storage capacity floppy disk or hard disk. It is applicable.

Here, when the servo track writer is used to write a servo pattern to each of the read / write area track and the read-only area track of the magnetic disk, the servo track writer has a narrow track pitch. The write head is provided with a gap portion adapted to the above. When writing a servo pattern on a track having a narrow track pitch in the read-only area, a predetermined servo pattern is formed by writing the servo pattern once in a normal writing mode, while the read / write operation is performed. When writing a servo pattern on a track having a standard wide (relatively wide) track pitch in a region, the first servo pattern is written by the first servo pattern writing, and then,
The writing position is shifted in the radial direction of the magnetic disk to write the second servo pattern by the second writing of the servo pattern. At this time, the first servo pattern and the second servo pattern are overwritten, and the predetermined servo pattern is written. A servo pattern is formed.

According to such a servo pattern forming method, the respective tracks having different track pitches are
When writing a servo pattern using a servo track writer, it is possible to use a single servo track writer and without changing the write head, so there is no need to write the servo pattern. Moreover, the servo pattern can be written at low cost.

[0020]

An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view showing an example of a schematic configuration of a magnetic disk which is a target of the servo pattern forming method of the present invention, and shows an example in which the magnetic disk is a hard disk.

FIG. 2 is an enlarged plan view of a part of a track obtained by an embodiment of the method for forming a servo pattern of a magnetic disk according to the present invention, in which (a) shows a track pitch Tpn of a width knuckle. The state of the data pattern and the servo pattern formed on the track, and (b) shows the state of the data pattern and the servo pattern formed on the track having a relatively wide (standard) track pitch Tps.

As shown in FIG. 1, the hard disk 1
Has an information recording area 2 formed on almost the entire effective area. In the information recording area 2, the inner peripheral area is set as the read / write area 3 and the outer peripheral area is set as the read only area 4. Has been done. In the read / write area 3, the center line of one track (track center)
And the center line of the track adjacent to it (track center)
A large number of tracks 5 (only a small part of them are shown) are formed such that the distance between them and the track pitch Tps becomes a standard wide width, and the tracks of tracks 5 are formed in the read-only area 4. A large number of tracks 6 (similarly only a part of them are shown) are formed such that the track pitch Tpn is wider than the pitch Tps. The hard disk 1 has a servo track writer (not shown) before the hard disk 1 is shipped.
Is used to write a servo pattern 8 (not shown in FIG. 1) composed of servo information and bursts in a part of a large number of tracks 6 having a track pitch Tpn of a narrow ridge in the read-only area 4. In addition, using the same servo track writer, as will be described later, servo information and bursts are provided at a part of many tracks 5 having a standard wide (relatively wide) track pitch Tps in the read / write area 3. Servo pattern consisting of 7
(Not shown in FIG. 1) is being written.

Here, based on FIGS. 2 (a) and 2 (b),
A forming process of forming the servo patterns 7 and 8 on the hard disk 1 shown in FIG. 1 by using a servo track writer will be described.

In this case, as the servo track writer for writing the servo patterns 7 and 8, a servo track writer provided with a write head having a gap portion adapted to the track pitch Tpn of the width ridge is used.

First, when the servo pattern 8 is formed, the servo pattern 8 including the servo information 8a and the burst 8b is written in a predetermined portion of each track 6 by a normal writing mode. At this time,
Two servo information 8a are written so that the center line (information center) of the information area of the servo information 8a coincides with the center line (track center) of the track 6, and
The burst 8b is written so that the outer edge and the inner edge of the information area of the burst 8b are in contact with the center line (track center) of the adjacent track 6, respectively. Servo information 8a and burst 8 in this writing
The writing order of b is arbitrary, for example, first,
The burst 8b is written on one side of the center line (track center) of the track 6, and then the write head of the servo track writer is slightly shifted in the radial direction of the hard disk 1 by a slight amount to shift the center line of the track 6 (track center). Servo information 8a is written in a state where the center line (information center) of the information area coincides with the (center), and then the write head of the servo track writer is slightly shifted again in the radial direction of the hard disk 1 by a certain amount, and The burst 8b can be written on the other side of the center line (track center) of the track 6. At this time, in the written servo information 8a, the outer edge and the inner edge of the information area are written on the center line (track center) of the adjacent track 6 as well.
It is formed so as to contact the inner edge and the outer edge of the information area a. The written burst 8b is formed such that the outer edge and the inner edge of the information area are in contact with the center line (track center) of the track 6 adjacent to the track 6.

Next, when the servo pattern 7 is formed, the servo information 7a ₁ and 7a ₂ and the burst 7 are written in a predetermined portion of each track 5 by the writing mode described below.
The servo pattern 7 composed of b ₁ and 7b ₂ is written. That is, with respect to the center line (track center) of each track 5, the first pseudo-track 5 ₁ and the second pseudo-track 5 are arranged slightly apart in the outer and inner circumferential directions and arranged in parallel with each track 5. ₂ assumes each align the write head servo track writer in the first pseudo track 5 ₁ of the center line (track center), the first predetermined position of the pseudo tracks 5 _1, the writing of the servo pattern 8 The first servo pattern consisting of the servo information 7a ₁ and the burst 7b ₁ is written in the same normal writing mode as that performed, and subsequently, the position of the write head of the servo track writer is set to the second pseudo pattern. fit track 5 _second center line (track center), the second of the same predetermined position of the pseudo tracks 5 _2, row writing of servo patterns 8 In the same normal writing manner as described above, the second servo pattern composed of the servo information 7a ₂ and the burst 7b ₂ is written, and the servo information 7a ₁ based on the writing of the first and second servo patterns, 7a ₂ and burst 7b ₁ , 7b ₂
The servo pattern 7 is written and formed by overwriting.

At this time, the two overwritten servo information 7a ₁ and 7a ₂ are formed such that the center line (information center) of the information area thereof coincides with the center line (track center) of the track 5. , Overwritten burst 7b
₁ and 7b ₂ are formed so that the outer edge and inner edge of the information area are in contact with the center line (track center) of the track 5 and the center line (track center) of the adjacent track 5, respectively. As a result, the overwritten servo information 7a ₁ and 7a ₂ are also overwritten with the outer edge and inner edge of the information area on the center line (track center) of the track 5 adjacent to the track 5. The bursts 7b ₁ and 7b ₂ are formed so as to contact the inner and outer edges of the information areas of the servo information 7a ₁ and 7a _{2 that} are written, and the overwritten bursts 7b ₁ and 7b ₂ are the outer and inner edges of the information areas. The edge is formed so as to be in contact with the center line (track center) of the track 5 adjacent to the track 5.

It should be noted that, as shown in FIG. 2, data is appropriately written in the portions other than the portions where the servo patterns 7 and 8 are written on both the tracks 5 and 6. is there.

As described above, according to the servo pattern forming method of the present embodiment, the writing of the servo pattern 8 on the track 6 having the track pitch Tpn of the narrow knuckle in the read-only area 4 is performed by a normal servo track writer. A predetermined servo pattern 8 is formed by writing the servo pattern once in the writing mode, and the servo pattern to the track 5 having a standard wide (relatively wide) track pitch Tps in the read / write area 3 is formed. In the writing of No. 7, the same servo track writer is used to write the first servo pattern consisting of the servo information 7a ₁ and the burst 7b _{1 by} the first writing of the servo pattern, and then the writing position is set to the hard disk 1. Shifting in the radial direction and writing the second servo pattern Only the _second servo pattern consisting of the servo information 7a ₂ and the burst 7b ₂ is written by using only the servo information 7a ₂ and the required servo pattern 7 by overwriting the first servo pattern and the second servo pattern.
Are formed.

Therefore, the track pitches Tpn, Tps
When writing the servo patterns 7 and 8 by the servo track writer on the respective different tracks 5 and 6, it is possible to use the same servo track writer and without replacing the write head. It is possible to write the servo patterns 7 and 8 at low cost without the need to write the servo patterns 7 and 8.

Although the hard disk 1 is used as the magnetic disk in the above embodiment, the description has been made.
The magnetic disk targeted by the present invention is not limited to the hard disk 1, but other magnetic disks such as, for example,
It can be applied to a high storage capacity floppy disk as well.

[0033]

As described in detail above, according to the present invention, when the servo pattern is written by the servo track writer on each track having a different track pitch, the same servo track writer is used, and Since the writing can be performed without replacing the writing head, there is an effect that the writing of the servo pattern does not take time and the writing of the servo pattern can be performed at low cost.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of a schematic configuration of a magnetic disk which is a target of a servo pattern forming method of the present invention.

FIG. 2 is an enlarged plan view of a part of a track showing an embodiment of a method for forming a servo pattern of a magnetic disk according to the present invention.

[Explanation of symbols]

1 Hard Disk (Magnetic Disk) 2 Information Recording Area 3 Read / Write Area 4 Read Only Area 5 Track 5 ₁ First Pseudo Track 5 ₂ Second Pseudo Track 6 Track 7 First Servo Pattern 7a ₁ , 7a ₂ Servo Information 7b ₁ , 7b ₂ burst 8 second servo pattern 8a servo information 8b burst

Claims (4)

[Claims] 1. A read / write area and a read-only area, which are independent of each other, are formed such that the track pitch of the read-only area is narrower than the track pitch of the read / write area, and When a servo pattern is formed on a magnetic disk in which servo patterns are respectively written in a track and a part of the track in the read-only area, writing is performed once in the track in the read-only area. To form the servo pattern, the first write is performed on the track in the read / write area, and the second write is performed by shifting the track in the radial direction of the magnetic disk to form the servo pattern. Servo pattern of magnetic disk characterized by Forming method. 2. The servo of a magnetic disk according to claim 1, wherein the servo track writer has a write head having a head gap adapted to a track pitch of the read-only area having a narrow width. Pattern formation method. 3. The method for forming a servo pattern of a magnetic disk according to claim 1, wherein the magnetic disk is a high storage capacity floppy disk. 4. The method for forming a servo pattern of a magnetic disk according to claim 1, wherein the magnetic disk is a hard disk.