JPS63127416A - Recording and reproducing device for discoid recording medium - Google Patents

Abstract

PURPOSE:To easily lead out an error signal for tracking servo and a data signal from reproduced outputs of heads by simultaneously recording a pair of servo signals with plural thin film heads. CONSTITUTION:One servo signal recording area 21 and the other servo signal recording area 22 which divide a track into two in the breadthwise direction are formed in a prescribed position of the track formed on a disk-shaped recording medium, and servo signals which are different in frequency or have phases inverted are recorded on areas 21 and 22. In this case, servo signals are simultaneously recorded by two-channel thin film heads which scan areas 21 and 22 respectively and whose one-side ends of coil conductors 3b and 4b are commonly connected. At the time of reproducing, the error signal for tracking servo is easily obtained based-on outputs obtained from prescribed terminals out of terminals 5-7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording/reproducing device for a disk-shaped recording medium that records data signals and servo signals on a recording medium such as a magnetic disk.

[Summary of the invention]

This invention relates to a recording/reproducing device for a disc-shaped recording medium that records data signals and servo signals on a recording medium such as a magnetic disk, in which two coil conductors are connected in a predetermined relationship as a magnetic head for recording/reproducing. By using a channel thin-film magnetic head, a data signal and a pair of servo signals that bisect the track in the width direction are simultaneously recorded in a predetermined area without causing track misalignment, and tracking is performed from the reproduction output of the thin-film magnetic head. This allows error signals and data signals for servo to be easily obtained.

[Conventional technology]

In general, in thin-film magnetic heads, the lower magnetic material, coil conductor, upper magnetic material, etc. that make up the head are formed by vacuum thin film forming technology such as sputtering, which makes it possible to produce heads with excellent mass production and uniform characteristics. In addition, since patterning is performed using photolithography technology, miniaturization such as narrow tracks and gaps can be easily achieved.

Therefore, in the thin film magnetic head, the head magnetic field involved in recording becomes steep, enabling high recording density recording and reproduction, high resolution recording, and further miniaturization.

Therefore, thin film magnetic heads have been put into practical use along with advances in vacuum thin film forming technology, and for example, so-called spiral thin film magnetic heads in which a coil conductor is spirally wound have been put into practical use.

The spiral type thin film magnetic head has advantages such as being able to form a large number of windings with a single layer of coil conductor and simplifying the manufacturing process. Furthermore, in order to obtain a higher magnetomotive force, so-called spiral multilayer thin film magnetic heads, in which multiple layers of spiral coil conductors are formed, have been widely put into practical use.

By the way, in a recording/reproducing apparatus for a disc-shaped recording medium such as a magnetic disk, in order to perform tracking servo, the track is divided into two in the width direction at a predetermined position.
A system is known in which a pair of servo signals having different frequencies or phases are recorded in each area.

[Problem that the invention seeks to solve]

However, in the conventional recording/reproducing apparatus for disc-shaped recording media, / Since only one magnetic head is provided for reproduction, when recording a servo signal, it is necessary to trace a predetermined position on the track twice and record the servo signal in each area. There was a drawback that it was not possible to write the data signal and the data signal continuously. Further, since the servo signal and the data signal cannot be written continuously, there is a possibility that a track shift may occur between the servo signal area and the data signal area.

Therefore, an object of the present invention is to divide the track into two in the width direction at a predetermined position on the track, so that the frequencies are different or
An object of the present invention is to provide a recording/reproducing device for a disc-shaped recording medium that can simultaneously record a pair of servo signals with opposite phases and easily obtain an error signal and data signal for tracking servo from the reproduction output of a thin-film magnetic head. .

[Means for solving problems]

This invention provides a servo signal recording area 21 (51) on one side and a servo signal recording area 22 (52) on the other side which divides the trunk into two in the width direction at a predetermined position of a track formed on a disc-shaped recording medium. In a recording/reproducing device for a disk-shaped recording medium, the servo signals having different frequencies or inverted phases are recorded in one and the other servo signal recording areas 21 and 22 (51 and 52), respectively. , scans one servo signal recording area and the other servo signal recording area, respectively, and scans each other's coil conductors 3b and 4b (
33b and 34a) A disc-shaped recording medium comprising first and second thin-film heads whose ends are commonly connected, and servo signals are simultaneously recorded by the first and second thin-film heads. This is a recording/playback device.

[Effect]

Coils 3 and 4 (33 and 34) have two magnetic cores 1 and 2 (31 and 32), and are wound in a predetermined direction around the respective magnetic cores 1 and 2 (31 and 32). A two-channel thin film magnetic head connected in a predetermined relationship is used, and a drive current is applied to predetermined terminals of terminals 5°6.7 (35, 36, 37) derived from coils 3 and 4 (33 and 34). By supplying a pair of servo signals having different frequencies or inverted phases, it is possible to simultaneously record a pair of servo signals in a predetermined area of the track in a manner that divides the track into two in the width direction. Also, during playback, terminal 5. 6. 7 (
An error signal for tracking servo can be easily obtained based on the output obtained from the predetermined terminals of 35, 36, 37).

〔Example〕

a. Description of one embodiment Hereinafter, one embodiment and other embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a conceptual configuration of a thin film magnetic head in an embodiment of the present invention. In Figure 1, 1
and 2 are magnetic cores, and the thin film magnetic head is composed of two channels.

A magnetic gap 1a is formed at one end of the magnetic core 1 that comes into sliding contact with a recording medium (for example, a magnetic disk, etc.), and a coil 3 is wound around the other end. Similarly, a magnetic gap 2a is formed at one end of the magnetic core 2, and a coil 4 is wound around the other end in the same direction as the winding direction of the coil 3. magnetic core l
and 2 is set to 2 μm, for example, and the width of each of the two magnetic cores is set to 25 μm, for example, so that the track width is regulated to approximately 52 μm. A terminal 5 is led out from one end of the coil 3, and a terminal 6 is led out from one end of the coil 4. Further, the other end of the coil 3 and the other end of the coil 4 are connected, and a terminal 7 is led out from this common connection point.

For example, FIG. 2 shows a specific example of a two-channel thin film magnetic head. FIG. 2 shows a plan view of a two-channel thin film magnetic head in one embodiment. In FIG. 2, numerals 8 and 9 indicate separate lower magnetic bodies.

On one plane of the lower magnetic bodies 8 and 9, SiO is formed except for the front gap portion and the back gap portion.

A first insulating layer is formed. Lower magnetic body 8
and 9, Mn-Zn-based ferrite and N1
- Lamination of ferromagnetic metal materials such as Fe-Ni alloy (Permalloy) or Fe-Al1-3i alloy (Sendust) on a ferromagnetic oxide substrate such as Zn-based ferrite or a non-magnetic substrate such as ceramic. A composite substrate in which a ferromagnetic metal material such as permalloy or sendust is laminated on a ferromagnetic oxide substrate is used.

Further, on the first insulating layer, lower coil conductors 3a and 4a made of a metal conductor such as Cu or A1 are arranged in a spiral shape at a predetermined interval (in this case, 4 coil conductors are arranged on the left and right in different winding directions.
(turn by turn).

Further, a second insulating layer is deposited to cover the lower coil conductors 3a and 4a, and on the second insulating layer, the winding direction is set between - and between the lower coil conductors 3a and 4a, respectively. One end is electrically connected to the lower coil conductors 3a, 4a through the contact windows 10 and 11 of the second insulating layer, and the other ends are commonly connected (in this case, the left and right The upper coils 3b and 4b are formed with three turns each. Also, this upper coil conductor 3
A third insulating layer is formed on b and 4b for insulation from upper magnetic bodies 12 and 13, which will be described later. That is,
A two-channel thin film magnetic head is formed by arranging two coil conductors in parallel with each other in a spiral 2N stacked seven-turn structure.

Here, the upper coil conductors 3b and 4b are different from the lower coil conductors 3a and 4a in the vicinity of the front gap (the part where the upper magnetic bodies 12 and 13 described later are remaining).
Since the coil conductors 3a, 4a and 3b, 4b are formed so as to fill the gap between them, the surfaces of the coil conductors 3a, 4a and 3b, 4b are formed substantially flat, and as a result, the upper magnetic bodies 12 and 13 are formed substantially flat, resulting in a good performance. This makes it possible to obtain excellent magnetic properties.

Further, the lower magnetic bodies 8 and 9 are provided so as to cover the third insulating layer and the like.
A ferromagnetic metal material such as sendust or permalloy is deposited over the entire surface of the upper magnetic body 12 and 13 using a vacuum thin film forming technique such as sputtering, and pattern etching is performed to obtain a predetermined track width and shape. It is formed. Therefore, the coil conductors 3a, 4a and 3b, 4
By supplying a drive current to b, a magnetic circuit is formed by the cooperation of the lower magnetic body 8 and the upper magnetic body 12, and the lower magnetic body 9 and the upper magnetic body 13, respectively, and recording/reproduction is performed. There is.

A terminal 5 is led out from the end of the lower coil conductor 3a, and a terminal 6 is led out from the end of the lower coil conductor 4a. At the same time, the terminal 7 is led out from the common connection point of the other ends of the upper coil conductors 3b and 4b.

The two-channel thin film magnetic head shown in FIG. 2 is used to record/reproduce servo signals and data signals. When recording servo signals, the terminals 5 and 7 are used to record the frequency r+ (e.g. f+ -100ktlz).
servo signals are recorded in predetermined areas of tracks on the recording medium. At the same time, the terminals 6 and 7 are used in parallel to record a servo signal of frequency ft (for example, fg=150 kHz) in a predetermined area. When the recording of the pair of servo signals that divides the track into two in the width direction is completed, the terminals 5 and 6 are used continuously, for example, the frequency fz
A data signal (different from f+ and f2) is recorded in a predetermined area.

FIG. 3 shows an example of a servo signal detection system in one embodiment, and when reproducing a servo signal, the frequency f,
servo signal recording area (indicated by 21 in Figure 3)
and the recording area of the servo signal of frequency f2 (indicated by 22 in FIG. 3) are simultaneously traced by a two-channel thin-film magnetic head, and the output obtained between terminals 5 and 6 is passed through a band-pass filter as the output of the thin-film magnetic head. 24
25 degrees.

The bandpass filter 24 has a characteristic of passing only a frequency component of approximately frequency f in the output signal of the thin film magnetic head, and the output of the bandpass filter 24 is supplied to the detection circuit 26. In the output fW 26 , the output of the bandpass filter 24 is waveform-shaped by, for example, envelope detection, and is supplied to one input terminal of the comparison circuit 28 .

Further, the band pass filter 25 has a characteristic of passing only the frequency component of approximately frequency f2 in the output signal of the thin film magnetic head, and the output of the band pass filter 25 is supplied to the detection circuit 27. In the detection circuit 27 , the output of the bandpass filter 25 is subjected to envelope detection, for example, to form a waveform, and is supplied to the other input terminal of the comparison circuit 28 .

In the comparison circuit 28, the output of the detection circuit 26 and the output of the detection circuit 27 are compared, and a comparison output corresponding to the difference is taken out from the output terminal 29 as an error signal. In other words,
An output corresponding to the area of the magnetic gaps la and 2a that are in sliding contact with the recording area 21 is generated in the detection circuit 26, and an output corresponding to the area of the magnetic gaps la and 2a that are in sliding contact with the recording area 22 is generated.
An output corresponding to the area of is generated in the detection circuit 27,
Tracking deviation is detected by comparing the two.

For example, when the thin film magnetic head is shifted toward the recording area 21 side as shown in FIG. It is controlled so that it becomes O.

In this state, the data signal recording area (indicated by 23 in FIG. 3) is traced and the data is reproduced by the output obtained between the terminals 5 and 6.

b. Description of another embodiment FIG. 4 shows the conceptual structure of a thin film magnetic head in another embodiment of the present invention. In FIG. 4, reference numerals 31 and 32 indicate magnetic cores, and the thin film magnetic head is composed of two channels.

A magnetic gap 31a is provided at one end of the magnetic core 31 that comes into sliding contact with a recording medium (for example, a magnetic disk, etc.).
is formed, and a coil 33 is wound around the other end. Similarly, magnetic materials.

A magnetic gap 32a is formed at one end of the core 32, and a coil 34 is wound around the other end in a direction different from the winding direction of the coil 33.

The size and spacing of the magnetic cores 31 and 32 are, for example, the same as in one embodiment, and the track width is regulated. coil 3
A terminal 35 is led out from one end of the coil 34, and a terminal 36 is led out from one end of the coil 34. Further, the other end of the coil 33 and the other end of the coil 34 are connected, and a terminal 37 is led out from this common connection point.

For example, FIG. 5 shows a specific example of a two-channel thin film magnetic head. FIG. 5 shows a plan view of a two-channel thin film head in another embodiment, in which the same materials as in the first embodiment are used, and coil conductors 33a and 33b are used.
, 34a, and 34b have substantially the same configuration except for the electrical connection relationship between them.

A first insulating layer is formed on one plane of the separate lower magnetic bodies 38 and 39 except for the front gap portion and the pack gap portion. On this first insulating layer, lower coil conductors 33a and 34a are arranged in a spiral shape at a predetermined interval (in this case, four turns each on the left and right in different winding directions).
is formed.

Further, a second insulating layer is formed to cover the lower coil conductors 33a and 34a, and the second insulating layer is wound in the same direction as the lower coil conductors 33a and 34a, respectively. A spiral shape (in this case Then 3 turns)
upper coil 33b and contact window 4 of the second insulating layer.
A spiral (three turns in this case) upper coil conductor 34b is electrically connected at one end to the lower coil conductors 3 and 4a via the coil conductor 34b.

That is, a two-channel thin-film magnetic head is formed by arranging two coil conductors in parallel with each other in a spiral two-layer seven-coun structure.

Here, the upper coil conductors 33b and 34b are arranged in the vicinity of the front gap (the upper magnetic body 4 described later) as in the embodiment.
3 and 44 remain, the surfaces of these coil conductors 33a, 34a and 33b, 34b are approximately As a result, the upper magnetic bodies 43 and 44 are formed substantially flat, and good magnetic properties can be obtained.

Further, the lower magnetic bodies 38 and 3 are provided so as to cover the third insulating layer.
A thin ferromagnetic metal film is deposited over the entire surface of the upper magnetic bodies 43 and 44 by sputtering, etc., and pattern etched to obtain a predetermined track width and shape.
is formed.

Thus, coil conductors 33a, 34a and 33b.

By supplying a drive current to 34b, the lower magnetic body 3
8 and the upper magnetic body 43 and the lower magnetic body 39 and the upper magnetic body 4
In cooperation with 4, a magnetic circuit is constructed, and recording/reproduction is performed.

A terminal 35 is led out from the end of the lower coil conductor 33a,
A terminal 36 is led out from the other end of the upper coil conductor 34b. At the same time, a terminal 37 is led out from the connection point between the other end of the upper coil conductor 33b and the end of the lower coil conductor 34a.

A two-channel thin film magnetic field shown in FIG. 5 is used to record and reproduce servo signals and data signals. When recording a servo signal, the terminals 35 and 36 are used to record a servo signal of a predetermined frequency in a predetermined area of a track on the recording medium. In other words, coil 33
And since the winding direction of the coil 34 is reversed, 18
A pair of servo signals with a 0° phase shift are simultaneously recorded in a predetermined area in the form of a portion of the trunk in the width direction. When the recording of the servo signal is completed, the terminals 35 and 37 and the terminals 36 and 37 are continuously used, and a recording current is supplied in parallel to record the data signal in a predetermined area.

FIG. 6 shows an example of a servo signal detection system in another embodiment. When reproducing a servo signal, the recording area of the normal phase servo signal (indicated by 51 in FIG. 6) and the recording area of the reverse phase servo signal are Signal recording area (indicated by 52 in Figure 6)
and are simultaneously traced by a two-channel thin film magnetic head, and the output obtained between terminals 35 and 37 is supplied to a detection circuit 55, and the output obtained between terminals 37 and 36 is supplied to a detection circuit 54.

In each of the detection circuits 54 and 55, one and the other output from the thin film magnetic head are waveform-shaped by, for example, envelope detection, and are supplied to one and the other input terminals of a comparison circuit 56.

In the comparison circuit 56, the output of the detection circuit 54 and the output of the detection circuit 55 are compared, and a comparison output corresponding to the difference is taken out from the output terminal 57 as an error signal. In other words,
The output corresponding to the area of the magnetic gap 32a that is in sliding contact with the recording areas 51 and 52 (for example, when sliding in contact with both the recording areas 51 and 52, the phase is shifted by 180 degrees, so the output is canceled out according to the area of sliding contact with each other) matching) is the detection circuit 54
At the same time, an output similar to the former corresponding to the area of the magnetic gap 31a in sliding contact with the recording areas 51 and 52 is generated in the detection circuit 55, and by comparing the two, the tracking deviation is detected.

For example, if the thin film magnetic head is displaced toward the recording area 51 as shown in FIG. It is controlled so that it becomes O.

In this state, the data signal recording area (indicated by 53 in FIG. 3) is traced, and the data is reproduced by the output obtained between the terminals 35 and 37 and the output obtained between the terminals 37 and 36.

In other embodiments of the present invention, the case where the data signal is recorded using the terminals 35 and 37 and between the terminals 36 and 37 has been described, but the data signal may be recorded using the terminals 35 and 36. However, during playback, terminals 35 and 3
Data may be reproduced based on the output obtained from 6.

Further, in other embodiments of the present invention, in particular, servo signals are recorded! ! It is possible to obtain an error signal for tracking servo from the data signal recording area without providing an area. In this case, the data signal is recorded using the terminals 35 and 36, and during playback, the error signal between the terminals 35 and 37 is An error signal can be obtained by comparing the output obtained between the terminals 37 and 36, and the data can be reproduced based on the output obtained between the terminals 35 and 36.

〔Effect of the invention〕

In this invention, a two-channel thin film magnetic head is used, which has two magnetic cores, each coil being wound in a predetermined direction around each magnetic core and connected in a predetermined relationship. By supplying a drive current to predetermined terminals of the three terminals derived from the coil, a pair of servo signals with different frequencies or inverted phases are applied to predetermined areas of the track in the width direction of the track. Can be recorded simultaneously.

Therefore, according to the present invention, it is not necessary to trace a predetermined position of a track twice when recording a servo signal as in a conventional recording/reproducing device for a disc-shaped recording medium, and track deviation occurs after recording a servo signal. Data signals can be recorded continuously without causing any problems. Further, according to the present invention, during reproduction, the 3
An error signal for tracking servo can be easily obtained based on the output obtained from a predetermined terminal of the terminals.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a thin film magnetic head according to an embodiment of the invention, FIG. 2 is a plan view showing a specific example of a thin film magnetic head according to an embodiment of the invention, and FIG. 3 is a schematic diagram of a thin film magnetic head according to an embodiment of the invention. A block diagram used to explain the operation of the embodiment, FIG. 4 is a schematic diagram of a thin film magnetic head in another embodiment of the present invention,
FIG. 5 is a plan view showing a specific example of a thin film magnetic head according to another embodiment of the invention, and FIG. 6 is a block diagram used to explain the operation of another embodiment of the invention. Explanation of main symbols in the drawings 1.2, 31, 32: magnetic core, la, 2a, 31a, 32a: magnetic gap, 3.4.
33, 34: Coil, 3a, 4a, 33a, 34a:
Lower coil conductor, 3b, 4b. 33b, 34b: Upper coil conductor, 5, 6, 7° 35
．． 36.31: @ko.

Claims (1)

[Scope of Claims] One servo signal recording area and the other servo signal recording area that divide the track in the width direction are formed at a predetermined position of a track formed on a disc-shaped recording medium, In a recording/reproducing device for a disc-shaped recording medium, the servo signals having different frequencies or having opposite phases are recorded in the other servo signal recording area, wherein the one servo signal recording area and the other servo signal The recording area is scanned respectively, and the first and second thin film heads are connected in common to one end of each other's coil conductors, and the servo signal is simultaneously recorded by the first and second thin film heads. A recording/reproducing device for a disk-shaped recording medium, characterized in that: