JPS62114117A - Magnetic disc - Google Patents

Abstract

PURPOSE:To read surely a servo pattern by setting the width of a servo pattern in the disc radial direction written along a prescribed track larger than the track width of an initialized data written on the prescribed track. CONSTITUTION:Lots of tracks T are formed concentrically on a floppy disc. Initializing data recording areas D0-D4 according to the prescribed format have a track width TW and a data is written to the center of tracks T0-T4 so as to be made coincident. On the other hand, servo pattern recording areas S0-S5 have a width equal to a track pitch TP reaching the center of the adjacent to the center of the tracks T0-T4. That is, the relation of TP>TW exists and the width of the areas S0-S5 is wider than the width TW. Thus, the servo pattern in the high track density disc device is read surely.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic disk used in a floppy disk device or a similar magnetic disk device, and relates to a magnetic disk used in a floppy disk device or a similar magnetic disk device. In particular, the present invention relates to a magnetic disk having a servo pattern for track servo.

[Conventional technology]

A floppy disk; 1) has a large number of concentric tracks T0 to TN-4 as shown in FIG. Each track T0 to TN has a plurality of sectors (5 sectors).
and each sector has a #! As shown in Figure 4, there are an ID field, a cap (GAP), and a data field.

Information indicating the start and address of the sector is recorded in the ID field, data, CRC bits, etc. are recorded in the data field, and the gigabyte acts as a buffer zone to protect the data.

By the way, since it is practically difficult to directly write main information data onto a non-recordable disc, initialization data consisting of ID field information and necessary information in the data field is written in advance according to the format shown in FIG. In addition, the magnetic head may be inserted into the servo pattern gap for track servo to accurately follow the track.

Figure 7 shows the conventional 192'rPIt) rack node.
・inch] truck T. -%-T, data recording areas D0 to D and servo pattern recording areas 80 to 8a
Show k. Data is written in the data recording areas D0 to D so that the center thereof coincides with the center of each track To-T. The servo pattern recording area 8° ~S, is recorded by the same magnetic head as the magnetic head for recording the initialization data, and has the same width as the track width Tw of the data recording area ~D, and tracks T, -. T, placed in the center between each other. Note that the servo pattern recording area S is located outside the outermost track T0. The groove is placed in the same position as when there is a track further outside. Since the track pitch T is 2 Tw, which is 1 jersey smaller, the servo pattern recording area S. A part of ~S is a data recording area. ~
It is an extension of D. Therefore, when scanning with the magnetic head of the track @Tw, there is a data recording area. ~D and above are scanned, and at the same time, a part of the servo pattern recording area 8°~S is also scanned, and the servo pattern recording can be read. For example, in track T0, the first servo pattern recording area S0 is first read and the read output level is maintained. Next, the second servo pattern recording area SI is read, and this reading output level and the servo pattern recording area S of the island 1 that has already been read are
The read output level of 0 is compared and this comparison output (
A DC motor, voice coil motor, or linear motor for moving the magnetic head is used so that the error output) becomes zero.
m is done. It should be noted that even if a stepping motor is used, it can be controlled by a servo pattern in the case of multiple steps per track. If control is performed using the servo pattern as described above, a magnetic head track T can be obtained. ~T, can be matched to the center.

[Problem that the invention seeks to solve p]

However, in recent years, the density of floppy disk devices has increased, and for example, 384TPI disk devices and 768TPI disk devices have become more dense.
I have a disk drive. Set it.

There are cases where data recorded on a 192 TPI low track density disk device may be read and read on a 384 TPI or 768 TPI high track density disk device. In this case, if the center metal of the magnetic head of the high track density disk device is aligned with the center of the track, data can be read normally. but.

The recording areas 80 to S1 of the servo pattern are formed to have the same width as the track, 1WlC, and are spaced apart from the center of the track by an interval, so the area that is scanned by the 6B air head is reduced, and 87N becomes worse. In the worst case, it becomes impossible to read the servo pattern.

Therefore, an object of the present invention is to provide a magnetic disk that can sufficiently read servo patterns when reading data from a low track density disk with a high track density disk device. Means for Solving the above-mentioned problems and achieving the above objectives, the present invention has a method in which at least one initialization data is written in a predetermined format on a predetermined track, and a track servo is operated along the predetermined track. In the magnetic disk in which a servo pattern for the servo is written in advance, the width of the servo turn in the radial direction of the disk is set to be thicker than the track width of the initialization data. It is related to magnetic disks.

[For production]

In the above invention, the radius t of the servo pattern distribution area
Since it is made larger than the track width, even when scanning with a magnetic head with a small track width of a high track density disk device, it is possible to read the turns smoothly and perform good track servo. ◎ [Example] Next, one aspect of the present invention will be explained in detail. FIG. 1 shows data recording areas D0 to D4 and servo pattern recording areas 80 to 8. of a 192TPI floppy disk according to an embodiment of the present invention. Q
show. The initialization data recording areas D0 to D according to the 7-ohm format shown in FIG.

Each track T0~ has a track width Tw as before.
It is drilled to match the center of T.

- 10,000, servo pattern recording area S. ~S, has a width equal to the track pitch TP extending from the center of each track T0~T, to the center of the adjacent track. 9 mouths, T
Since P>Tw, the servo pattern recording area 80 to S
, is larger than the track width Tw.

The recording pattern shown in FIG. 1 can be formed by the magnetic head (2) shown in FIG. 2. This magnetic head (2) has a track width Tw corresponding to 192 TPI.
core (4) with data write gap (3) of
and a core (61
It consists of Then, the core +41+6
1 is placed and worked.

When the pattern shown in FIG. 1 is obtained using the magnetic head (2) shown in FIG.

A servo pattern recording area S0 is also formed using the gap (5) at the timing mar. Next, track T1
When forming the data recording area S, the servo pattern recording area S is also formed by adjusting the timing. That is,
Data recording area D0 is created by scanning tracks T0 to T4.
-D4 and servo pattern recording areas 80-S4, respectively. When data has been written to the innermost (maximum) track TN (not shown), the track T (N+1 in the figure, not shown) one track inside the innermost track is written, and the last servo pattern recording area SN is written.
+1 (not shown). Note that the read timing is adjusted so that the servo pattern is located in the gap between the ID field and the data field shown in FIG.

In Figure 1, data and servo pattern writing area D
0 to D, , 5o-8, are shown with diagonal lines for explanatory purposes, but in reality, they are recorded bit by bit, for example, in the MPM system. The servo pattern is formed by continuously recording a plurality of bits.

When writing initialization data as shown in FIG. 1 using the magnetic head (2) shown in FIG. 2, the data recording areas D0 to DIv and Servo pattern recording area 80-S,
can be obtained. For this j.

In the case of FIG. 7, in order to falsely form the data recording areas D0-D and the servo pattern recording areas 80-S, twice the number of tracks is required.

For example, 384TP from a disk with the pattern shown in Figure 1.
When reading data with a high track density disk device of I, the track width of the FIiJ head becomes narrow. However, the center of the gap of the magnetic head is set to tracks T0 to T1.
If you align it with the center of 6, you will have a data storage area. -D4
data can be reliably read. ! Servo pattern recording area 80 by high track density magnetic head
~S, reading and track servo are performed in the same manner as before. At this time.

Since half of the gap of the magnetic head scans the servo pattern recording areas 80 to S, 87N is not so bad. Therefore, track servo based on reading the servo pattern can be successfully achieved.

[Modified example]

The invention is not limited to the embodiments described above.

For example, the following modifications are possible.

(al As shown in FIG. 5, the width of the core (4a) constituting the data writing head and the core (6a) constituting the servo pattern writing head are made the same, and the notch (
7) By providing (8), data writing gap (3) and servo pattern writing gap (51
You may adjust the position.

The core (4b) is grown so that the width of the R/W (read/write) gap (31) is equal to the track pitch TP, as shown in FIG.

Core Qll with a pair of erase gaps 191QI'
established.

Erase gap (width T of 910Ql is (TP-Tw)/2
It may be set to In this case, the cancellation gap (9)
A current is applied to the erase head including the R/W to bring it into the erase state.
Due to the gap (3), the data recording area D0~ in FIG.
Form D4. As a result, the track of width TP written in gap (3) is erased by gap (9) and becomes 1 width Tw. Next, the erase head is turned off, the gap (31) is moved to one side of the initialization data track, and the servo pattern recording areas S0 to S are sequentially erased. In this method.

Since the entire effective area of the disk is scanned by the gap (31), there is no need to erase the entire disk before writing initialization data.

(cl In Fig. 1, servo pattern No. e area So~
S.

Although the width of i is defined as the track pitch TP, it may be made slightly smaller or larger than i.

〔Effect of the invention〕

As is clear from the above, according to the present invention, the width of the servo pattern is made wider than the track width, so that the servo pattern can be reliably read in a high track density disk device.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a recording pattern on a magnetic disk according to an embodiment of the present invention. FIG. 2 is a plan view showing a magnetic head according to an embodiment of the present invention. FIG. 3 is a plan view of the magnetic disk. #! Figure 4 shows the data format. FIG. 85 and FIG. 6 are plan views showing modified magnetic heads, respectively. Figure 1g7 is a plan view showing a conventional recording pattern. (1)...Disk, (2)...Head, (3)...
... Gap for reading data, (5) ... Gap for writing servo pattern, So-Ss ... Servo pattern recording area.

Claims (2)

[Claims] (1) In a magnetic disk in which at least initialization data is written in a predetermined format on a predetermined track, and a servo pattern for track servo is written in advance along the predetermined track, the servo pattern is arranged in the radial direction of the disk. A magnetic disk characterized in that the width of the track is set larger than the track width of the initialization data. (2) The servo pattern includes a first pattern having a width from the center of one track to the center of a track adjacent to one side, and a first pattern having a width from the center of one track to the center of a track adjacent to the other side. 2. The magnetic disk according to claim 1, wherein the magnetic disk comprises a second pattern having a width of .