JPS61264508A - Magnetic disc device - Google Patents

Abstract

PURPOSE:To simplify the structure of a head part by performing tracking accurately without recording a servo signal on a magnetic disc. CONSTITUTION:When data is read, switch circuits connected to auxiliary heads 1 and 5 are switched selectively, and track deviation is detected by outputs generated in auxiliary heads 1 and 5, and a head moving device 12 is operated in accordance with track deviation. When data is written, the floppy disc read state is temporarily set, and servo information concerning a track where data should be written is detected and is stored in a memory 14. Thereafter, switch circuits 2 and 6 are switched selectively, and erasing currents are supplied to auxiliary heads 1 and 5, and the width of a track formed by a recording and reproducing head 21 is controlled. A switch circuit 11 is switched selectively, and the head moving device 12 is operated on a basis of servo information stored in the memory 14, and the position of the head part is corrected to eliminate track deviation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic disk device used in a personal computer or the like, and particularly relates to a configuration for performing tracking servo of a magnetic disk.

[Summary of the invention]

In a magnetic disk device used in a personal computer or the like, the present invention causes an auxiliary head provided after a write head to function as a reproducing head when reading data, and tracks the track by the output generated by each of the auxiliary heads. Detects the deviation, corrects the head position in response to the track deviation, and at the time of writing, temporarily stores the servo information in the read state in memory, and then
By supplying erasing current to the auxiliary head to make it function as an erasing head and correcting the head position based on the servo information stored in the memory, tracking servo can be performed even if servo information is not recorded on the magnetic disk. This is what I did.

[Conventional technology]

Conventionally, large amounts of data have been stored by being recorded on hard disks or data cartridges, and floppy disks have been used for small amounts of data.

However, now that the amount of data handled by personal computers and the like has increased, the realization of a floppy disk with a capacity of about 5 to IOM bytes is awaited.

In order to increase the capacity of a floppy disk, it is necessary to increase the track density beyond the conventional track density of 135TP1. It becomes necessary to adopt tracking servo in consideration of various problems such as king accuracy.

Therefore, it is possible to perform tracking servo by recording servo information on a floppy disk at equal angular intervals and reading it, but in this case, a special servo signal must be recorded on the floppy disk, and the floppy disk data storage capacity is reduced. Additionally, there is a drawback that the tracking servo system itself is expensive.

Therefore, it has been proposed to provide a head for detecting the track position in the head section without recording servo signals on the floppy disk, and to perform tracking servo using the output of this head.

FIG. 5 shows the configuration of a head section when a track position detection head is used. In FIG. 5, 31 is a recording/playback node for reading/writing data.

A pair of detection nodules 32 and 33 for detecting the track position are provided at a position in front of the head 31, that is, at a position preceding the rotational direction of the magnetic disk 30 (indicated by an arrow in the figure). Further, at a position behind the head 31, that is, at a position trailing in the direction of rotation of the magnetic disk 30 (indicated by an arrow in the figure), a pair of erasing heads 34 and 35 for regulating track width, which are made of the same core, are installed. It is provided.

The detection heads 32 and 33 order reproduction outputs on both sides of the tracks formed on the magnetic disk 30. For example, if the centers of the track 36 and the read/write head 31 coincide with each other as shown in FIG.
Approximately equal reproduction outputs are taken from the detection heads 32,33. In addition, when the recording/reproducing head 31 is tracing outward from the track 36, the output of the detection head 33 provided on the inside becomes larger than the output of the detection head 32 provided on the outside. . On the other hand, the recording/playback head 3
1 is traced inwardly with respect to the track 36, the output of the detection head 32 provided on the outside becomes larger than the output of the detection head 33 provided on the inside.

In this way, the outputs of the detection heads 32 and 33, which vary depending on the trace state of the recording/reproducing head 31 with respect to the track 36, are supplied to the comparison circuit via an amplifier and a signal processing circuit. In the comparison circuit, the detection head 32.33
The outputs from the two are compared and the difference output is determined.

This difference output is supplied as a control signal to the head moving device, and the head section is displaced in the width direction of the track.
The outputs of the detection heads 32 and 33 are controlled to be approximately equal.

The erasing heads 34 and 35 regulate the width of the track formed by the read/write head 31 to a predetermined width, and are provided at a predetermined interval narrower than the width of the track formed by the read/write head 31. ing. Therefore, when the erase current is supplied to the head 34.35, both sides of the track traced by the head 34.35 are erased, and the width of the track 36 is made to be a specified width.

When reading data recorded on the floppy disk, tracking servo is applied by the outputs of the aforementioned detection heads 32 and 33 for detecting track positions, and the recording/reproducing head 31 reads the data. When recording data on a floppy disk, tracking servo is similarly applied by the outputs of the detection heads 32 and 33, data is written by the recording/reproducing head 31, and the erasing head 3 for regulating the track width
An erase current is supplied to 4.35, and both sides of the track are erased so that the width of the track becomes a predetermined width.

[Problem that the invention seeks to solve]

The conventional configuration in which tracking servo is performed using the above-mentioned track position detection head has a problem in that the head portion has a complicated structure and is accordingly expensive.

Therefore, an object of the present invention is to provide a magnetic disk device that can perform accurate tracking without recording servo signals on the magnetic disk, and can perform tracking servo with a simple structure without making the head section complicated. It is in.

[Means to solve problems]

The present invention includes: a write head 21; a pair of track width regulating heads 1.5 which follow the write head 21 and are provided at a predetermined interval in the width direction of the track formed by the write head 21; means 2 and 6 for supplying an erase current to the track width regulating head 1.5 at the time of reading, and means 1 for detecting a track deviation from the output of the track width regulating head 1.5 and correcting the track deviation during reading.
1. A magnetic disk device characterized by comprising: 2.

[Effect]

A pair of auxiliary heads 1 and 5 are arranged in a head portion having a read/write recording/reproducing head 21 and are located close to the recording/reproducing head and trailing in the direction of rotation of the magnetic disk.
They are provided at predetermined intervals narrower than the track width formed by. When reading data, the auxiliary heads 1 and 5
Switch circuits 2.6 connected to each of the auxiliary heads 1 and 5 are selectively switched, track deviation is detected by the outputs generated in the auxiliary heads 1 and 5, and the head moving device 12 is operated in response to the track deviation. Further, when writing data, the floppy disk is temporarily put into a read state, servo information regarding the track to be written is detected, and this servo information is stored in the memo IJ 14. Thereafter, this switch circuit 2.6 is selectively switched, an erase current is supplied to the auxiliary heads 1 and 5, and the track width formed by the recording/reproducing head 21 is regulated.
The switch circuit 11 is selectively switched, and the head moving device 1 is switched based on the servo information stored in the memory 14.
2 operates, the position of the head section is corrected, and the track deviation is removed.

〔Example〕

a. Configuration of the head section of one embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment in which the present invention is applied to a magnetic disk device that uses, for example, a stepping motor, voice coil, bimorph, etc. as a drive source for a head moving device.

In FIG. 1, the forces indicated by 1 and 5 are a pair of auxiliary heads.The auxiliary heads 1 and 5 are located close to the read/write recording head 21 as shown in FIG. It is mounted on a common base with the recording/reproducing head 21, and the position behind the recording/reproducing head 21, that is, the magnetic disk 2
They are provided at predetermined intervals narrower than the track width formed by the recording/reproducing head 21 at positions trailing Q with respect to the rotational direction of the recording/reproducing head 21 (arrow in the figure).

One auxiliary head 1 is connected to the terminal 2a of the switch circuit 2, and the other auxiliary head 5 is connected to the terminal 6a of the switch circuit 6.
It is connected to the. A terminal 2b of the switch circuit 2 is connected to an input terminal of an amplifier 3, and a terminal 6b of the switch circuit 6 is connected to an input terminal of an amplifier 7. In addition, terminals 2C and 6C of switch circuits 2 and 6 are connected to the erase signal generator 16.
is connected to the output terminal of

b. Description of read mode in one embodiment The switch circuits 2 and 6 are switched in conjunction. In the read mode for reproducing data recorded on the magnetic disk 20, the terminals 2a and 2b of the switch circuit 2 are connected, and the terminals 6a and 6b of the switch circuit 6 are connected.

In this case, the auxiliary heads 1 and 5 function as reproducing heads, and the auxiliary heads 1 and 5 reproduce data recorded on the magnetic disk 20. For example, as shown in FIG. 2, when the head traces so as to always be centered on a predetermined track 22, the auxiliary heads 1 and 5 generate outputs of approximately equal small levels.

However, if the head section deviates outward with respect to the track 22 and traces, the auxiliary head 5 generates a playback output at a level corresponding to the amount of deviation, and the auxiliary head 1 produces almost no playback output. do not have. On the other hand, track 22
When the head part shifts inward and traces, the auxiliary head 1 generates a playback output at a level corresponding to the amount of shift, and the auxiliary head 5 generates a playback output. do not.

In this way, the reproduction output of the auxiliary head 1 that changes depending on the tracing state of the head section with respect to the track 22 is supplied to the amplifier 3, and the reproduction output of the auxiliary head 5 is supplied to the amplifier 7.

The output of the amplifier 3 is supplied to a signal processing circuit 4, envelope detection is performed, and an output corresponding to the peak level is supplied to a comparison circuit 9. Further, the output of the amplifier 7 is supplied to a signal processing circuit 8, where envelope detection is performed, and an output corresponding to the peak level is supplied to a comparison circuit 9.

In the comparison circuit 9, the output of the signal processing circuit 4 and the output of the signal processing circuit 8 are compared. The difference output of the comparison circuit 9 is supplied to an integrator, and a control signal is taken out at the output of the integrator IO. This control signal is supplied to one input terminal tia of the switch circuit 11 and is also supplied to the A/D converter 13.

The switch circuit 11 is switched in conjunction with the switch circuits 2 and 6, and in the read mode, one input terminal 11a of the switch circuit 11 and the output terminal 11C are connected.

One input terminal 11a of the switch circuit 11 and the output terminal 1
1C, a control signal is sent to the head moving device 12.
supplied to Drive source of head moving device ■2, e.g.
A bimorph formed by pasting together two piezoelectric elements is operated by a control signal, the head section is displaced in the width direction of the track, and the reproduction outputs of the auxiliary heads 1 and 5 are controlled so as to be approximately equal. , tracking deviation is removed.

Description of write mode in one embodiment of C8 When recording data on a predetermined track of a magnetic disk,
At the time of access, the read mode is temporarily set and the track is accessed. During this temporary write mode, tracking servo information during the write mode is detected.

At this time, the tracking control signal supplied to the A/D converter 13 is converted from analog to digital and supplied to the memory 14 as a digital signal. Further, in a magnetic disk rotation angle detector 15 such as a rotary encoder, an address corresponding to the rotation angle of the magnetic disk is generated, and this address signal is supplied to the memory 14 as a write address.

The memory 14 has a control terminal 14a, and at the time of access, for example, a high level signal is supplied to the control terminal 14a, and the memory 14 is placed in a write state. Therefore, tracking control signals for the head moving device 12 are sequentially stored in the memory 14 as digital data as the magnetic disk rotates.

For example, as shown in FIG. 3, when the magnetic disk is rotated by a predetermined angle with respect to the position where the index is recorded on the magnetic disk, the rotation angle detector 15 generates an address θ. When this address θ1 occurs, the difference between the predetermined track (solid line 23 in the figure) and the head scanning locus (solid '1IA24 in the figure), that is, the head movement amount ΔR1 required to correct the track deviation.
A tracking control signal corresponding to the above is taken into the memory 14 as digital data. Furthermore, as the magnetic disk rotates, the address (θ2...θ
n) are sequentially generated, and a tracking control signal corresponding to the head movement amount (ΔRt, "ΔR,,") required to correct the track deviation is taken into the memory 14 as digital data, and a tracking control signal corresponding to the head movement amount (ΔRt, "ΔR,,") required for correcting the track deviation is taken into the memory 14 and is moved to a predetermined track 23. A tracking control signal for the entire area is stored in the memory 14.

Then, the light mode is set, and the other input terminal 11b and output terminal 11c of the switch circuit 11 are connected. A low level signal is supplied to the control terminal 14 of the memory 140, and the memory 14 is placed in a read state. The tracking control signals written as described above are sequentially read out from the memory 14 by addresses sequentially generated in the rotation angle detector 15 as the magnetic disk rotates. This tracking control signal is converted into an analog tracking control signal by the D/A converter 17, and is supplied to the head moving device 12. The head moving device 12 is displaced by a tracking control signal, the head section is displaced in the width direction of the track, and data is written to a predetermined track 23 by the recording/reproducing head 21.

Further, when the write mode is set, the terminal 2a and the terminal 2C of the switch circuit 2 are connected, the terminal 6a and the terminal 6C of the switch circuit 6 are connected, and the erase signal generator 16 is connected to the auxiliary heads 1 and 5. Erase current is supplied from Therefore, the auxiliary heads 1 and 5 function as erasing heads, and both sides of the track are erased so that the track width formed by the recording/reproducing head 21 is regulated to a predetermined width.

d. Other Embodiments FIG. 4 shows another embodiment in which the present invention is applied to a magnetic disk drive in which, for example, a DC motor is used as a drive source for a head moving device.

In other embodiments, a movement amount detector 18 such as a rotary encoder for digitally detecting the movement amount of the head portion is provided in association with the head portion.
8 to obtain servo information, and the same reference numerals are given to the parts corresponding to those in the above-mentioned embodiment.

When the read mode is set to reproduce the data of a predetermined track recorded on the magnetic disk, the auxiliary heads 1 and 5 function as reproduction heads as in the above-mentioned embodiment; A tracking deviation is detected by the output, and the head moving device 12 is displaced in accordance with the tracking deviation, thereby eliminating the tracking deviation.

In the write mode in which data is recorded on the magnetic disk, the read mode is temporarily set when the I-rack is accessed, and the memory 14 is placed in the write state. Servo information corresponding to the amount of movement of the head generated in the movement amount detector 8 is supplied to the memory 14, and
The data are sequentially fetched into the memory 14 in accordance with the addresses from . When the servo information for the entire track is captured, the write mode is entered.

When the write mode is set, the other input terminal 11b and output terminal 11c of the switch circuit 11 are connected, and the memory 14 is placed in a read state, as in the first embodiment. As the magnetic disk rotates, the rotation angle detector 15
According to the addresses generated by , sequentially from the memory 14,
Servo information is read. This servo information is the comparison circuit 1
9.

The comparator circuit 19 is supplied with servo information from the movement amount detector I8, and the two are digitally compared, and the difference output is converted into a tracking control signal by D/A conversion, and is used as a tracking control signal for the head moving device. 12. The head moving device 12 operates according to the tracking control signal,
Tracking deviation is removed and data is written by the recording/reproducing head 21.

In addition, when the write mode is set, the erasing current is supplied to the auxiliary heads 1 and 5 as in the first embodiment, the auxiliary heads 1 and 5 function as erasing heads, and the tracks formed by the recording/reproducing head 21 are erased. Both sides of are erased.

e. Modified Example In one embodiment and other embodiments of the present invention, a configuration in which a rotary encoder is used as the rotation angle detector 15 has been described. It is also possible to use a configuration in which addresses are generated temporally.

〔Effect of the invention〕

In this invention, a pair of auxiliary heads are provided in a head section having a read/write recording/reproducing head, the pair of auxiliary heads being close to the recording/reproducing head and trailing in the direction of rotation of the magnetic disk, and formed by the recording/reproducing head. They are provided at predetermined intervals narrower than the track width. When reading data, this auxiliary head functions as a head for detecting track position,
Track misalignment is detected by the output obtained from the auxiliary head, and the head position is corrected in response to the track misalignment. Also, when writing data, the system temporarily enters the read state, stores the servo information in the memory, and then writes the data using the recording/playback head while correcting the head position based on the servo information stored in the memory. , an erase current is supplied to the auxiliary head to cause the auxiliary head to function as a head for regulating track width. Therefore, according to this invention,
Even if no servo signals are recorded on the magnetic disk, accurate tracking can be performed, and tracking servo can be performed during recording and reproduction without complicating the structure of the head section.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of this invention, FIG. 2 is a route map used to explain an embodiment of this invention, FIG. 3 is a route map used to explain an embodiment of this invention, and FIG. The figure is a block diagram of another embodiment of the present invention, and FIG. 5 is a route map used to explain the conventional technology. Explanation of main symbols in the drawings ■, 5: Auxiliary head, 2, 6.11: Switch circuit,
9: comparison circuit, 12 two-head moving device, 14: memory, 15: rotation angle Ml output, 16: erasure signal generator. Agent Patent Attorney Tadashi Sugiura Go to Figure 1 - Tsurh's 1J1 Ya - Figure 2 Drac rE Figure 3 Figure 4

Claims (1)

[Scope of Claims] A write head; a pair of track width regulating heads that follow the write head and are provided at a predetermined interval in the width direction of the track formed by the write head; A magnetic disk device comprising: means for supplying an erase current to a width regulating head; and means for detecting a track misalignment from the output of the track width regulating head during reading and correcting the track misalignment.