JPH03187074A - Head positioning system for magnetic disk device - Google Patents

Abstract

PURPOSE:To properly record a signal on a discrete track disk by shifting center lines of both of servo and data tracks by the extent of shift between both of reproducing and recording heads in each position of a supporting arm. CONSTITUTION:In the case of tracks others than an innermost peripheral track Ti, a reproducing head Hp and a recording head Hr are shifted in the radial direction of the disk, but the head Hr always accurately scans the data track regardless of off-track of the head Hp to record a proper recording signal free from blur, erase omission, or the like because a center line C3 of the servo track and a center line C2 of the data track are in positions shifted by the same extent as heads. Though the head Hp scans the off-track position of the data track, the width of the head is made narrower than that of the track to prevent the head from going out of the track, and reproducing is not hindered.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides a rotary support arm with a playback head and a recording head separately, and the playback head picks up a servo signal from a disk to perform track servo control. The present invention relates to a head positioning system for a magnetic disk drive.

[Summary of the Invention] The present invention provides a rotating support arm with a reproducing head and a recording head separately, a disk with a servo track and a data track, and areas other than these with a non-magnetic layer. , in a head positioning system for a magnetic disk device that performs track servo by picking up a servo signal of the servo track with the reproducing head, the amount of shift of the recording head in the disk radial direction with respect to the reproducing head at each rotational position of the support arm; By shifting the center of the servo track with respect to the center of the data track by this amount of shift in the opposite direction, bleeding during recording can be avoided because the recording head is scanned while just tracking the data track. ,
A proper recording signal can be recorded without causing any unerased data.On the other hand, the playback head is scanned off-track to the data track, but it is generally configured to have a narrower width than the data track, and in order to scan within the data track. There is no problem with playback.

[Prior Art] There is a so-called discrete track disk in which servo tracks and data tracks are alternately provided in the circumferential direction, and the servo tracks and data tracks are magnetic layers, and the rest are non-magnetic layers. This discrete track disk has the data track width narrower than the recording head width, and has the advantage that recording signals can be recorded without bleeding or unerased areas during recording.

On the other hand, as the head support means of the disk drive device, a rotary support arm is adopted to make it smaller and lighter, and as the recording and reproducing means, it is used as both a reproducing head and a recording head in order to achieve high track density. Sometimes different things are used without having to do so.

As shown in Fig. 5, a rotating support arm is used, and two heads, a playback head (Hp) and a recording head (Hr), are attached to this support arm, and a discrete track disk is used as a recording medium. By using
It is possible to manufacture a magnetic disk device that is small and lightweight, and that can perform high-density recording and reproduction without bleeding during recording.

[Problems to be Solved by the Invention] However, in the magnetic disk drive described above, for example, as shown in FIG. Hp) and the center line (C8) of the recording head (Hr) to the track center line (C8).
7), the head center line (C8) and the track center line (c=) form a skew angle (θ) at other positions, so they do not match. This angle increases as it goes toward the outer track and reaches its maximum at the outermost track (To). Therefore, the playback head (Hp)
When the track servo is applied and the recording mode is executed,
In order for the reproducing head (Hp) to just track and scan, the recording head (Hp) is
r) will scan the off-track position. If the edge of the recording head (Hr) goes off-track until it scans over the data track, smearing or unerased data will occur during recording, so there is no point in using a discrete track disk.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a head positioning system for a magnetic disk device in which a recording head just tracks scans a data track to record an appropriate recording signal even when a discrete track disk is used as a recording medium. do.

[Means for Solving the Problems] To achieve the above object, a head positioning system for a magnetic disk drive according to the present invention has a support arm rotatably supported at its proximal end, which has a reproducing head and a recording head at its distal end. and ' are provided separately, and the rotation of the support arm moves the reproducing head and the recording head approximately in the radial direction of the disk, and the disk has a servo track for recording servo signals and a data track for recording data signals. The data signal is picked up by the reproducing head, and the rotational position of the support arm is changed based on the picked up servo signal to generate a track servo. In a head positioning system for a magnetic disk drive, the amount of shift of the recording head in the disk radial direction with respect to the reproducing head at each rotational position of the support arm is determined, and the center line of the servo track is moved in the opposite direction by the amount of shift. This is provided by being shifted with respect to the center line of the data trap.

[Function] The playback head picks up the servo signal of the disk, track servo is applied, and the playback head scans the just track position of the servo track, but the center line of the servo track and the center line of the data track are aligned with the playback head. Since the recording head is shifted by the amount of shift in the disk radial direction, the recording head scans the just track position of the data track and records a recording signal during recording. on the other hand,
The playback head scans the off-track position of the data track, but since the playback head is configured to be narrower than the data track width, even if the playback head goes off-track, it scans within the data track enough to interfere with playback. will not occur.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

An embodiment of the present invention is shown in FIGS. 1(a) to 4. FIG.

FIG. 2 shows a schematic configuration diagram of a magnetic disk device. In FIG. 2, the base end of the support arm 1 is connected to the rotating shaft 1a.
It is rotatably supported.

This rotating shaft 1a is rotated by an arm driving means (not shown) to drive a reproducing head (Hp) and a recording head (Hr) as described below.
) are the innermost track (Ti) and the outermost track (To)
move in the radial direction of the disk. A slider body 2 is attached to the tip of the support arm l, and the slider body 2 is provided with a magnetoresistive reproducing head (Hp) and a wire-wound recording head (Hr) as shown in FIG. There is. The reproducing head (Hp) and the recording head (Hr) are arranged on the center line (C8) of the support arm 1 with an interval of - feet apart, with the recording head (Hr) at the front position and the reproducing head (Hp) at the rear position. It is provided. Recording head (H
The width (d,) of r) is configured to be sufficiently larger than the width (d,) of the reproducing head (Hp). Then, the center line of the support arm I (
C□), that is, the playback head (Hp) and the recording head (Hr
) is arranged so that its center line (cl) coincides with the track center line (C1).

FIG. 3 shows a format diagram of the disc 3. In FIG. 3, track areas with different radii are formed on the disk 3 at constant pick intervals around the center of rotation, and each track area has a servo area (C8).
and data areas (Eo) are formed alternately. As shown in Figures 1(a) and (b), the servo area (C5
) has a servo track (T5) and a data area (ED
) is provided with a data track (TD), and a servo track (TS) and a data track (TD)
is a magnetic layer, and the rest is a non-magnetic layer. The servo track ('rs) has a track address section (TA) and three fine address sections (A) and (B).
, (C). A track address signal is recorded in the track address area (TA), and burst signals of the same frequency are recorded in the fine address areas (A), (B), and (C).

From the picked up burst signal output (A-B)/C
Servo track ('rs) by calculating the formula of
The off-track amount with respect to the center line (C8) of the fine address portions (A) and (B) is calculated.

The width (d3) of (C) is the width (d, ) of the playback head (Hp)
It is preferable to make it the same as this because it improves the servo characteristics.

The data track (TD) is an area where a data signal is recorded, and its width is narrower than the width (d+) of the recording head (Hr) and wider than the width (d,) of the reproducing head (Hp). As shown in Figure 1(b), the innermost track (T
In i), the center line (C3) of the servo track (Ts) is configured to coincide with the center line (C1) of the data track ('ro), but as shown in Figure 1 (b), For tracks other than (T i ), the center line (C8) of the servo track (TS) is the data track ('rD)
It is arranged at a position shifted with respect to the center line (C9) of. As shown in FIG. 4, this shift position is determined by the shift amount (X
) is determined, and the position (S) is set at a position (S) shifted by this shift amount (X) in the reflection direction. The shift amount (X) is
The distance between the playback head (Hp) and the recording head (Hr) is f
f, ) If the skew angle between the rack centerline (C2) and the centerline (cl) of the support arm l is θ, then X=(sinθ
The value increases as you move toward the outer track.

The operation of the above configuration will be explained below.

During recording and reproduction, when the reproduction head (Hp) scans over the servo track (TS), the reproduction head (Hp) picks up the track address signal and the burst signal. The track address at the time of current travel is recognized from the picked up track address signal, and the amount of off-track is recognized from the burst signal, and the reproducing head (Hp) is driven just on the servo track (T, . . . ).

As shown in FIG. 1(a), on the innermost track (Ti), the reproducing head (Hp) and the recording head (Hr) are not shifted in the disk radial direction, and the center line (C1) of the servo track (TS) is ) and the center line ('ro) of the data track ('ro)
C7) is in the same position as the playback head (Hp
) and the recording head (Hr) are both data tracks (TD).
Scanned with just track. As shown in Fig. 1(b), in the tracks other than the innermost track (Tf), the reproducing head (Hp) and recording head (Hr) are shifted in the disk radial direction by the same amount of shift. Since the center line (C5) of the servo track (T8) and the center line (C2) of the data track (TD) are at shifted positions, the reproducing head (Hp) scans the off-track position, but the recording head (Hr) Scan just track position. Therefore, the recording head (Hr) is always on the data track (
In order to scan the just track position of the data track (TD), a proper recording signal is recorded on the data track (TD) without causing any bleeding or unerased areas during recording. On the other hand, the playback head (Hp) scans the off-track position of the data track (TD), but since the playback head (Hp) is configured to be narrower than the data track width, the playback head (Hp) scans the off-track position of the data track (TD).
The end of the data track (TD) does not protrude outside the data track (TD), and there is no problem in playback.

[Effects of the Invention] As described above, according to the present invention, a reproducing head and a recording head are provided separately on a rotating support arm, and a magnetic disk head positioning system using a discrete track disk as a recording medium is provided. , determining a shift amount of the recording head in the disk radial direction with respect to the read head at each rotational position of the support arm, and shifting the center of the servo track with respect to the center of the data track in the opposite direction by this shift amount. Because the recording head is scanned while just tracking the data track, it is possible to record a proper recording signal without causing bleeding or unerased areas during recording, while the playback head can be scanned just on the data track. Generally, the width of the data track is narrower than that of the data track, and since the data track is scanned, there is no problem in reproduction.

[Brief explanation of drawings]

FIG. 1(a) to FIG. 4 show embodiments of the present invention.
Figure (a) is a pattern diagram of the innermost track, Figure 1 (b)
2 is a diagram of the pattern of tracks other than the innermost track, FIG. 2 is a schematic configuration diagram of a magnetic disk device, FIG. 3 is a diagram of a disk format, FIG. 4 is a diagram showing calculation of shift amount, and FIG. FIG. 2 is a diagram showing the head arrangement state at each rotational position of a conventional support arm. 1... Support arm, 3... Disk, Hp... Playback head, Hr... Recording head, T5... Servo track, TD... Data track, C1... Center line of data track. cl: Center line of servo track. Figure 2 Figure 8 Figure 4

Claims (1)

[Claims] (1) A reproducing head and a recording head are separately provided at the distal end of a support arm whose proximal end is rotatably supported, and rotation of the support arm moves the reproducing head and the recording head approximately in the radial direction of the disk. The disk is provided with a servo track for recording a servo signal and a data track for recording a data signal, and the rest other than the servo track and the data track is made of a non-magnetic layer, and the data signal is read by the reproducing head. In a head positioning system for a magnetic disk drive that performs track servo by displacing the rotational position of the support arm based on the picked-up servo signal, A head positioning system for a magnetic disk drive, characterized in that a shift amount in the disk radial direction is determined, and the center line of the servo track is shifted in the opposite direction by the shift amount with respect to the center line of the data track.