JPH07201002A - Magnetic recording/reproducing device - Google Patents

Abstract

PURPOSE:To accurately perform tracking by obtaining a sufficient S/N signal as a servo signal and recording/reproducing data while always detecting and positioning the signal. CONSTITUTION:When data is recorded, tracking is performed while detecting a servo signal recorded in an intra-plane anisotropic film 2 with a ring type magnetic head part 9 and a current is supplied to a coil 6. By this, by a magnetic field of a vertical direction of a single magnetic pole type magnetic head 10, a data signal is recorded in a vertical anisotropic film 3. Also, even at the time of reproducing, as in the case of recording, while detecting the servo signal recorded in the intra-plane anisotropic film 2 by the ring type magnetic head 9 tracking is performed based on this detected signal and the data signal recorded in the vertical anisotropic film 3 is reproduced by the head part 10. In a case where an MR film 12 is disposed, tracking is performed based on the servo signal recorded in the film 2 and the recorded data in the vertical anisotropy 3 is reproduced with a film 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus having a servo signal recording layer in addition to a data recording layer.

[0002]

2. Description of the Related Art In recent years, demands for higher recording density in hard disk devices have been increasing, and linear density and track density have been improved. In order to perform highly accurate tracking in such a situation, a data surface servo, a sector servo, etc. are conventionally used. Therefore, in order to secure the servo data area, the data cannot be recorded on the entire surface of the disk, and the data area cannot be secured sufficiently.

As a method of securing the servo area without sacrificing the data area, there is a belly servo (deep servo) in which the magnetic recording layer of the in-plane magnetic recording medium has a two-layer structure and servo information is recorded in one of the layers. However, since both are in-plane recording, it is necessary to change the data frequency region and the servo frequency region. Further, when a perpendicular recording medium is used, it is not possible to separately record and reproduce signals in the surface layer portion and the deep layer portion because of the magnetic property peculiar to perpendicular recording that magnetization is uniformly generated in the depth direction. .

Regarding the perpendicular recording medium in which the servo recording area is secured, for example, Japanese Patent Laid-Open Publication No. 60-26.
No. 3313 discloses a servo signal recorded in an in-plane recording layer disposed below a perpendicular recording layer, but cannot obtain sufficient S / N for reproducing with a single magnetic pole type magnetic head. Further improvement was required to use it as a servo signal. Further, there is a vertical recording medium in which a servo recording area is secured, which is disclosed in Japanese Patent Laid-Open Publication No. Sho 61-68723. However, even in this case, the S / N necessary as the servo signal cannot be obtained, and Improvement was needed.

[0005]

As described above, in the conventional magnetic recording / reproducing apparatus, in order to position the disk, the data surface servo is required to secure the servo area for recording the servo information. Although the sector servo is used, there is a problem that the data area for securing the servo area cannot be sufficiently obtained and the tracking accuracy is deteriorated when the track density is increased.

In a magnetic recording / reproducing apparatus which uses a perpendicular recording method for data recording, a servo method using an in-plane recording layer has been proposed as a method for performing servo without using a data surface servo or a sector servo. The conventional method has a problem that it is not possible to obtain a sufficient S / N to be used as a servo signal.

The present invention ensures a servo signal recording area without sacrificing the data area and performs high-accuracy and high-speed tracking even when a vertical recording medium suitable for high density is used. It is an object of the present invention to provide a magnetic recording / reproducing device capable of achieving the above.

[0008]

A magnetic recording / reproducing apparatus of the present invention comprises a magnetic film having anisotropy in a direction perpendicular to a recording medium surface (hereinafter referred to as a perpendicular anisotropic film) and a recording medium surface. A magnetic disk having a magnetic film having anisotropy in the in-plane direction (hereinafter referred to as an in-plane anisotropic film) and a magnetic film having soft magnetic characteristics (hereinafter referred to as a soft magnetic film) at the same time, and a perpendicular magnetic disc. A magnetic head (preferably a single magnetic pole type magnetic head and a ring type magnetic head) for independently performing recording and reproduction on the anisotropic film and the in-plane anisotropic film was provided, and the magnetic head was obtained from any one of them. A control circuit for positioning based on the servo signal is provided.

If desired, a magnetic shield material may be provided between the two magnetic heads. Further, the distance from the surface of the magnetic recording medium of the magnetic disk to the soft magnetic film can be 0.2 μm or less.

The magnetic recording / reproducing apparatus of the present invention is a magnetic disk having a perpendicular anisotropic film, an in-plane anisotropic film and a soft magnetic film at the same time, and a magnetic disk for recording on the perpendicular anisotropic film. Head (preferably single-pole magnetic head), magnetic head including a magnetoresistive effect magnetic film (hereinafter referred to as MR film) for reproducing a signal recorded on a perpendicular anisotropic film, and in-plane anisotropy A magnetic head (preferably a ring type magnetic head) for performing recording / reproducing on the film is provided, and a control circuit for performing positioning based on a servo signal obtained from any of those magnetic heads is provided.

Further, in the magnetic recording / reproducing apparatus of the present invention, for example, a servo signal is recorded on an in-plane anisotropic film on a recording medium surface of a magnetic disk, reproduced by a ring type magnetic head, and given to a control circuit. You can also

[0012]

In the magnetic recording / reproducing apparatus of the present invention, a magnetic disk having a perpendicular anisotropic film, an in-plane anisotropic film and a soft magnetic film at the same time in the magnetic recording medium surface, a perpendicular anisotropic film and Each in-plane anisotropic film is equipped with a magnetic head for recording / reproducing independently, and a control circuit for recording / reproducing a servo signal for either the perpendicular anisotropic film or the in-plane anisotropic film is provided. By providing it, it is possible to secure a sufficient data area and perform high-accuracy and high-speed tracking even when perpendicular recording is used.

Further, by providing the soft magnetic film below the perpendicular anisotropic film, it is possible to record and reproduce a data signal of higher quality.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a perspective view of a first embodiment of a magnetic recording / reproducing apparatus of the present invention, and FIG. 2 is a sectional view thereof. In this magnetic recording / reproducing apparatus, a magnetic disk 8 having a magnetic layer provided on a substrate 1 in the order of a soft magnetic film 11, an in-plane anisotropic film 2 and a perpendicular anisotropic film 3, a magnetic core 5 and a coil 7. And a single magnetic pole type magnetic head portion 10 including a magnetic pole 4 and a coil 6.

In the magnetic layer of the magnetic disk 8, a non-magnetic film for completely separating the magnetization may be arranged between the in-plane anisotropic film 2 and the perpendicular anisotropic film 3. Further, in order to obtain a sufficient S / N ratio of the servo signal, the coercive force Hcl of the in-plane anisotropic film 2 in the in-plane direction of the medium and the coercive force Hcp of the perpendicular anisotropic film 3 in the perpendicular direction to the medium are large. Relationship is Hcl>Hcp> 80
It is preferably 0 (Oe). Table 1 shows the servo signal S / N and the data signal S / when the recording wavelength λ is 0.5 μm or less and the track pitch Tp is 3 μm or less.
N is standardized and shown in <Example A>.

[0016]

[Table 1] Hcp Hcl Servo signal Data signal (Oe) (Oe) S / N S / N <Example A> 800 1500 1 1 <Example B> 1000 1800 1.3 1.1 <Example C> 1500 2500 1.4 1.2 < Comparative Example D> 1500 700 0.4 1.2 From Table 1, Hcl = 700 (Oe) <800 (Oe) <H
If cp is set, it can be seen that the servo signal S / N is extremely lowered.

Further, as shown in FIG. 3, in order to perform sufficient recording / reproducing on the perpendicular anisotropic film 3, the distance l from the surface of the magnetic disk 8 to the surface of the soft magnetic film 11 is 0.2 μm or less. Is desirable. Further, the single magnetic pole type magnetic head unit 10 may be provided with a return path portion (auxiliary magnetic pole) for efficient recording and reproduction.

Further, as a head section dedicated to data reproduction,
The MR film 12 may be partially disposed as shown by an imaginary line in FIG. In this case, the gap length 15 of the ring type magnetic head portion 9 is preferably wider than the film thickness 16 of the MR film 12. Also, since two types of heads are used,
When recording or reproducing, the head magnetic fields interfere with each other,
The servo signal S / N decreases. Therefore, in order to prevent magnetic field interference between the two types of head portions, magnetic films (shield films) 13 and 14 having soft magnetic characteristics are inserted between the two types of head portions as shown by phantom lines in FIG. Is desirable.
Table 2 shows the effect when the shield films 13 and 14 are inserted.

[0019]

[Table 2] Head MR film Shield film Type when recording data during data reproduction Existence Existence Existence Servo signal S / N Servo signal S / N a None None 1 1 b None Yes 1.3 1.7 c Yes None 1.1 1.1 d Yes Shield 13 1.1 1.7 Only Yes e Yes Shield 14 1.2 Only 1.7 f Yes Both shields 1.5 2 Yes In the magnetic recording / reproducing apparatus configured as described above, by passing a current through the coil 7, the ring type magnetic head 9
The servo signal is previously recorded on the in-plane anisotropic film 2 by the magnetic field in the in-plane direction. When recording data, while the servo signal recorded on the in-plane anisotropic film 2 is detected by the ring-type magnetic head unit 9, tracking is performed based on the servo signal and a current is passed through the coil 6. As a result, the perpendicular magnetic anisotropy film 3 is applied by the magnetic field in the vertical direction of the single magnetic pole type magnetic head unit 10.
Record the data signal on. At this time, since the soft magnetic film 11 is arranged below the vertical anisotropic film 3, sufficient recording can be performed on the vertical anisotropic film 3. Also, during data reproduction, as in the case of recording, while the servo signal recorded on the in-plane anisotropic film 2 is detected by the ring-type magnetic head unit 9, tracking is performed on the basis of the servo signal, and vertical misalignment occurs. The data signal recorded on the anisotropic film 3 is reproduced by the single magnetic pole type magnetic head unit 10. Further, when the MR film 12 is arranged, while the servo signal recorded on the in-plane anisotropic film 2 is detected by the ring-type magnetic head unit 9, tracking is performed based on the servo signal and the perpendicular The data signal recorded on the anisotropic film 3 is M
Reproduction is performed by the R film 12.

Next, a control circuit for positioning the magnetic head with respect to the magnetic disk having the above structure to perform magnetic recording / reproducing will be described. FIG. 4 shows an embodiment of the tracking servo system control circuit for the magnetic disk of the present invention. The tracking servo system control circuit includes a magnetic disk 20 having a magnetic layer formed of a soft magnetic film, an in-plane anisotropic film, and a perpendicular anisotropic film, and a servo head incorporated in a composite magnetic head 30. An amplifier 31 for amplifying a signal from a certain ring type magnetic head unit, a filter 32 for removing noise included in a servo signal, a timing generator 33 for capturing a servo signal, and an output from the timing generator 33. A window generator 34 that generates a window based on a signal, a servo signal detector 35 that detects a servo signal in the window, a peak hold 36 that detects a peak value of the servo signal, and two peak values in the window Comparator 37 for calculating the difference between VCM driver 38 and the comparator 37 for calculating the current value given to the VCM driver 38 based on the output signal from the comparator 37. A vessel 39, to detect the off-track amount from a signal of the comparator 37, the read-write control signal and the off-track detector 40 for generating a read-write circuit 4 of the single pole type magnetic head incorporated in the magnetic heads 30
It consists of 1.

The tracking servo operation by the control circuit having the above configuration will be described. Servo information is recorded on the in-plane anisotropic film of the magnetic disk 20 as shown in FIG. This servo information is formed in a ring shape and concentrically with a track width T.

In response to such servo information, when the magnetic head 30 is completely on-track, an output as shown in FIG. 6 (b) is obtained from the ring type magnetic head portion, and the output within the window is 2 The two peak values a and b have the same value. However, when the magnetic head 30 is displaced in the inner circumferential direction, a signal as shown in FIG.
When the magnetic head 30 is displaced in the outer peripheral direction, FIG.
A signal as shown in is obtained. That is, the magnetic head 3
When 0 shifts to the inner circumference side, the signal a in the window becomes smaller and the signal b becomes larger. Further, when the magnetic head 30 shifts to the outer peripheral side, the signal a in the window increases and the signal b decreases. From these, the peak value a of the output signal from the ring type magnetic head portion incorporated in the magnetic head 30 is obtained.
The difference between b and b can take a value proportional to the off-track amount of the magnetic head 30.

FIG. 7A shows changes in the peak value a when the magnetic head 30 moves in the disk radial direction. FIG. 6B shows the change in the peak value b when the magnetic head 30 moves in the disk radial direction. The magnetic head 30 is positioned as follows using this change in peak value.
That is, the difference signal between the peak value a and the peak value b as shown in FIG. 7C is obtained. When the signal is negative, a force in the outer circumferential direction proportional to the absolute value of the value is applied to the head, and when the signal is positive, a force in the inner circumferential direction proportional to the value is applied to the magnetic head.

By such control, the magnetic head 30
Is positioned at the track center of each position Xn (here, Xn + 1 = Xn + T) at the interval T where the difference signal between the peak value a and the peak value b becomes 0. Further, at the time of seek, the seek distance of the head can be controlled by obtaining the distance traveled by the magnetic head 30 from the signal having the period T shown in FIG. Here, if the peaks or troughs of the signal in FIG. 7C are detected k times, the moving distance of the magnetic head 30 is obtained as k × T.

Next, a second embodiment of the magnetic recording / reproducing apparatus of the present invention will be described with reference to FIG. In this magnetic recording / reproducing apparatus, an in-plane anisotropic film 2 and a soft magnetic film 11 are formed on a substrate 1.
b, a magnetic disk 8 in which a magnetic layer is provided in the order of the perpendicular anisotropic film 3, a ring type magnetic head portion 9 including a magnetic core 5 and a coil 7, and a single magnetic pole type magnetic head portion 10 including a magnetic pole 4 and a coil 6. Are formed from. The servo system of this embodiment is the same as that of the embodiment of FIG. 1, and the control circuit shown in FIG. 4 is adopted.

In this embodiment as well, as in the first embodiment, the single magnetic pole type magnetic head portion 10 may be provided with a return path portion for efficient recording / reproducing. Also,
As a head exclusively for data reproduction, the MR film 12 may be partially disposed as shown by an imaginary line. In this case, the gap length 15 of the ring type magnetic head portion 9 is preferably wider than the film thickness 16 of the MR film 12. Further, in order to prevent magnetic field interference between the two types of head portions, it is desirable to insert magnetic films (shield films) 13 and 14 having soft magnetism between the two types of head portions as shown by imaginary lines. Also, the first
In the same manner as in the above embodiment, in order to obtain a sufficient S / N ratio of the servo signal, the coercive force Hcl of the in-plane anisotropic film 2 in the in-plane direction of the medium is calculated.
And the magnitude of the coercive force Hcp of the perpendicular anisotropic film 3 in the perpendicular direction to the medium are preferably Hcl>Hcp> 800 (Oe). Further, in order to perform sufficient recording / reproducing on the perpendicular anisotropic film 3, it is desirable that the distance 1 from the surface of the magnetic disk 8 to the surface of the soft magnetic film 11b is 0.2 μm or less.

In the magnetic recording / reproducing apparatus of the second embodiment, in the magnetic disk 8, by arranging the soft magnetic film 11b between the perpendicular anisotropic film 3 and the in-plane anisotropic film 2, the in-plane The signal can be recorded / reproduced on / from the vertical anisotropic film 3 without deteriorating the quality of the signal recorded on the anisotropic film 2.

FIG. 9 shows a third embodiment of the magnetic recording / reproducing apparatus of the present invention.
3 is a cross-sectional view of the embodiment of FIG. This magnetic recording / reproducing apparatus includes a magnetic disk 8 in which a magnetic layer is provided on a substrate 1 in the order of a soft magnetic film 11, an in-plane anisotropic film 2, a soft magnetic film 11b, and a perpendicular anisotropic film 3, and a magnetic core. 5 and a coil 7 and a single magnetic pole type magnetic head 10 composed of a magnetic pole 4 and a coil 6. The servo system of this embodiment is the same as that of the embodiment of FIG. 1, and the control circuit shown in FIG. 4 is adopted.

Also in the third embodiment, as in the first embodiment, the single magnetic pole type magnetic head portion 10 may be provided with a return path portion for efficiently performing recording and reproduction. Further, as a head exclusively for data reproduction, the MR film 12 may be partially disposed as shown by an imaginary line. In this case, the gap length 15 of the ring-type magnetic head unit 9
Is preferably wider than the film thickness 16 of the MR film 12. Further, in order to prevent magnetic field interference between the two types of head portions, it is desirable to insert magnetic films (shield films) 13 and 14 having soft magnetism between the two types of head portions as shown by imaginary lines. Further, as in the first embodiment, the S of the servo signal is
In order to obtain sufficient / N, the relationship between the coercive force Hcl of the in-plane anisotropic film 2 in the in-plane direction of the medium and the coercive force Hcp of the perpendicular anisotropic film 3 in the medium perpendicular direction is Hcl>Hcp> 800
It is desirable that it is (Oe). In addition, the vertical anisotropic film 3
In order to perform sufficient recording and reproduction, the distance l from the surface of the magnetic disk 8 to the surface of the soft magnetic film 11b is preferably 0.2 μm or less.

In the magnetic recording / reproducing apparatus of the third embodiment, in the magnetic disk 8, the soft magnetic film 11b is provided between the perpendicular anisotropic film 3 and the in-plane anisotropic film 2 in the in-plane anisotropic film 2. By arranging the soft magnetic film 11 underneath, the S / N signal which is sufficient for the perpendicular anisotropic film 3 is recorded and reproduced without deteriorating the quality of the signal recorded on the in-plane anisotropic film 3. can do.

FIG. 10 is a sectional view of the fourth embodiment of the magnetic recording / reproducing apparatus of the present invention. This magnetic recording / reproducing device
A magnetic disk 8 having a magnetic layer provided on a substrate 1 in the order of a soft magnetic film 11, an in-plane anisotropic film 2, a perpendicular anisotropic film 3 and a soft magnetic film 11c, a ring composed of a magnetic core 5 and a coil 7. The magnetic head unit 9 includes a magnetic head unit 9 and a single magnetic pole unit 10 including a magnetic pole 4 and a coil 6. The servo system of this embodiment is the same as that of the embodiment of FIG. 1, and the control circuit shown in FIG. 4 is adopted.

Also in the fourth embodiment, as in the first embodiment, the single magnetic pole type magnetic head portion 10 may be provided with a return path portion for efficient recording / reproducing. Further, as a head exclusively for data reproduction, the MR film 12 may be partially disposed as shown by an imaginary line. In this case, the gap length 15 of the ring-type magnetic head unit 9
Is preferably wider than the film thickness 16 of the MR film 12. Further, in order to prevent magnetic field interference between the two types of head portions, it is desirable to insert a magnetic film (shield film) having soft magnetism between the two types of head portions as shown by an imaginary line. Further, as in the first embodiment, in order to obtain a sufficient S / N of the servo signal, the coercive force Hcl of the in-plane anisotropic film 2 in the in-plane direction of the medium and the perpendicularity of the perpendicular anisotropic film 3 to the medium are obtained. Direction coercive force Hcp
It is desirable that the relationship of the magnitudes of Hcl>Hcp> 800 (Oe).

In the magnetic recording / reproducing apparatus of the fourth embodiment, the soft magnetic film 11c is arranged between the perpendicular anisotropic film 3 and the in-plane anisotropic film 2 in the magnetic disk 8 so that the perpendicular magnetic field changes. A high quality signal can be recorded / reproduced on / from the anisotropic film 3.

FIG. 11 is a sectional view of the fifth embodiment of the magnetic recording / reproducing apparatus of the present invention. This magnetic recording / reproducing device
A magnetic disk 8 in which a magnetic layer is provided on a substrate 1 in the order of a soft magnetic film 11, a perpendicular anisotropic film 3, and an in-plane anisotropic film 2, and a ring type magnetic head portion 9 including a magnetic core 5 and a coil 7. When,
It is formed of a single magnetic pole type magnetic head portion 10 including a magnetic pole 4 and a coil 6. In the magnetic layer of the magnetic disk 8, a nonmagnetic film for completely separating the magnetization may be arranged between the in-plane anisotropic film 2 and the perpendicular anisotropic film 3. The servo system of this embodiment is the same as that of the first embodiment, and the control circuit shown in FIG. 4 is adopted.

Also in the fifth embodiment, as in the first embodiment, the single magnetic pole type magnetic head portion 10 may be provided with a return path portion for efficient recording / reproducing. Further, as a head exclusively for data reproduction, the MR film 12 may be partially disposed as shown by an imaginary line. In this case, in order to prevent magnetic field interference between the two types of head portions, magnetic films (shield films) 13 and 14 having soft magnetism may be inserted between the two types of head portions as indicated by imaginary lines. desirable. Further, as in the first embodiment, in order to obtain a sufficient S / N of the servo signal, the in-plane anisotropic film 2 is used.
The relationship between the coercive force Hcl in the in-plane direction of the medium and the magnitude of the coercive force Hcp of the perpendicular anisotropic film 3 in the medium perpendicular direction is Hcl>Hcp> 8.
It is desirable that it is 00 (Oe). Further, in order to perform sufficient recording / reproducing on the perpendicular anisotropic film 3, the distance l from the surface of the magnetic disk 8 to the surface of the soft magnetic film 11 is 0.2 μ.
It is preferably m or less.

FIG. 12 is a sectional view of the sixth embodiment of the magnetic recording / reproducing apparatus of the present invention. This magnetic recording / reproducing device
A magnetic disk 8 in which a magnetic layer is provided on a substrate 1 in the order of a soft magnetic film 11, a perpendicular anisotropic film 3, an in-plane anisotropic film 2, and a soft magnetic film 11c, a ring composed of a magnetic core 5 and a coil 7. The magnetic head unit 9 includes a magnetic head unit 9 and a single magnetic pole unit 10 including a magnetic pole 4 and a coil 6. In the magnetic layer of the magnetic disk 8, a nonmagnetic film for completely separating the magnetization may be arranged between the in-plane anisotropic film 2 and the perpendicular anisotropic film 3. The servo system of this embodiment is the same as that of the embodiment of FIG. 1, and the control circuit shown in FIG. 4 is adopted.

Also in the sixth embodiment, as in the first embodiment, the single magnetic pole type magnetic head portion 10 may be provided with a return path portion for efficient recording / reproducing. Further, as a head exclusively for data reproduction, the MR film 12 may be partially disposed as shown by an imaginary line. In this case, in order to prevent magnetic field interference between the two types of head portions, magnetic films (shield films) 13 and 14 having soft magnetism may be inserted between the two types of head portions as indicated by imaginary lines. desirable. Further, as in the first embodiment, in order to obtain a sufficient S / N ratio of the servo signal, the coercive force Hcl of the in-plane anisotropic film 2 in the in-plane direction of the medium and the perpendicularity of the perpendicular anisotropic film 3 to the medium are obtained. The relationship of the magnitude of the coercive force Hcp in the direction is Hcl>Hcp>
It is preferably 800 (Oe).

FIG. 13 is a perspective view of the seventh embodiment of the magnetic recording / reproducing apparatus of the present invention. This magnetic recording / reproducing device
A soft magnetic film 11 is arranged on the substrate 1, and an in-plane anisotropic film 2 formed in a stripe shape in the track direction is arranged on the soft magnetic film 11.
Further, a magnetic disk 8 composed of a perpendicular anisotropic film 3 formed so as to cover the in-plane anisotropic film 2, a ring type magnetic head part 9 composed of a magnetic core 5 and a coil 7, and a magnetic pole 4. It is formed of a single magnetic pole type magnetic head portion 10 including a coil 6. Here, the track center of the ring type magnetic head unit 9 is relatively displaced from the track center of the single magnetic pole type magnetic head unit 10.

In manufacturing the magnetic disk 8 of this embodiment, the soft magnetic film 11 is formed by sputtering or plating, the in-plane anisotropic film 2 is sputtered, and a stripe-shaped mask is applied and then etching is performed. The vertical anisotropic film 3
It is possible to adopt a method in which the vertical anisotropic film 3 is uniformly formed by sputtering after filling in the etched portion.

In the seventh embodiment as well, the first
As in the embodiment described above, the MR film 12 can be partially disposed as shown in FIG. 2 as a head dedicated to data reproduction. The servo system of this embodiment is the same as that of the embodiment of FIG. 1, and the control circuit shown in FIG. 4 is adopted.

FIG. 14 is a perspective view of the eighth embodiment of the magnetic recording / reproducing apparatus of the present invention. The structure of the magnetic disk 8 and the structures of the ring type magnetic head section 9 and the single magnetic pole type magnetic head section 10 of this magnetic recording / reproducing apparatus are the same as those of the seventh embodiment shown in FIG. Head part 9
And the track centers of the single pole type magnetic head portion 10 are made substantially equal to each other.

Also in this embodiment, the MR film 12 may be partially disposed as shown in FIG. 2 as a head exclusively for data reproduction. The servo system of this embodiment is the same as that of the embodiment of FIG. 1, and the control circuit shown in FIG. 4 is adopted.

FIG. 15 is a sectional view of the ninth embodiment of the magnetic recording / reproducing apparatus of the present invention. In this magnetic recording / reproducing apparatus, the ring type magnetic head portion 9 and the single magnetic pole type magnetic head portion 10 constituting the composite type magnetic head are the same as those in the embodiment of FIG. 13, but the soft magnetic film of the magnetic disk 8 is used. An in-plane anisotropic film 2 having a stripe shape in the track width direction on a part of 11
Is formed.

Even in this embodiment, the MR film 12 may be partially disposed as shown in FIG. 2 as a head exclusively for data reproduction.

FIG. 16 is a sectional view of the magnetic recording / reproducing apparatus according to the tenth embodiment of the present invention. In this magnetic recording / reproducing apparatus, the ring type magnetic head portion 9 and the single magnetic pole type magnetic head portion 10 constituting the composite type magnetic head are the same as those in the embodiment of FIG. 13, but the soft magnetic film of the magnetic disk 8 is used. 11
The in-plane anisotropic film 2 is formed in a stripe shape in the track width direction on a part of the vertical anisotropic film 3. Even in this embodiment, the MR film 12 may be partially disposed as shown in FIG. 2 as a head exclusively for data reproduction.

FIG. 17 shows the output from the single magnetic pole type magnetic head portion 10 when reproducing is performed by the first embodiment of the magnetic recording / reproducing apparatus of the present invention configured as described above. The output from 9 is shown in FIG. Looking at the output of the single magnetic pole type magnetic head unit 10 shown in FIG. 17, since the contribution of the servo signal from the in-plane anisotropic film 2 is small,
The data signal recorded on the vertical anisotropic film 3 can be reproduced without damaging it. Further, looking at the output of the ring type magnetic head portion 9 shown in FIG. 18, since the contribution of the data signal from the vertical anisotropic film 3 is small, the servo signal recorded in the in-plane anisotropic film 2 is It can be regenerated without damage.

As described above, according to the magnetic recording / reproducing apparatus of the present invention, since the data signal and the servo signal can be reliably separated, both the data signal and the servo signal can be detected with good S / N.

[0048]

According to the present invention, a perpendicular anisotropic film for recording a data signal of a magnetic disk, an in-plane anisotropic film for recording a servo signal, and a soft magnetic layer for ensuring a sufficient S / N at the time of recording / reproducing. A film, a magnetic head for recording (reproducing) a data signal, a magnetic head for recording and reproducing a servo signal, and a control circuit for detecting and positioning a servo signal obtained from the magnetic head for recording and reproducing a servo signal are provided. Therefore, a sufficient S / N signal can be obtained as a servo signal, and high-precision tracking is possible by always recording and reproducing data while detecting the servo signal and performing positioning.

Further, since the servo information is recorded in the depth direction, it is not necessary to provide a servo surface and a servo sector separately from the data surface, and the recording capacity of the magnetic disk can be increased.

[Brief description of drawings]

FIG. 1 is a perspective view of a first embodiment of the present invention.

FIG. 2 is a sectional view of the first embodiment of the present invention.

FIG. 3 is a graph showing a change in a data signal obtained from a single magnetic pole type head portion according to the distance from the surface of the magnetic disk to the surface of the soft magnetic film in the first embodiment of the invention.

FIG. 4 is a block diagram of a control circuit adopted in the first embodiment of the present invention.

FIG. 5 is an explanatory diagram of a servo pattern recorded by the ring type magnetic head unit according to the first embodiment of the present invention.

FIG. 6 is a waveform diagram of a positioning signal reproduced by the ring type magnetic head unit in the first embodiment of the invention.

FIG. 7 is a waveform diagram of a servo signal obtained from the ring type magnetic head unit in the first embodiment of the invention.

FIG. 8 is a sectional view of a second embodiment of the present invention.

FIG. 9 is a sectional view of a third embodiment of the present invention.

FIG. 10 is a sectional view of a fourth embodiment of the present invention.

FIG. 11 is a sectional view of a fifth embodiment of the present invention.

FIG. 12 is a sectional view of a sixth embodiment of the present invention.

FIG. 13 is a perspective view of a seventh embodiment of the present invention.

FIG. 14 is a perspective view of an eighth embodiment of the present invention.

FIG. 15 is a perspective view of a ninth embodiment of the present invention.

FIG. 16 is a perspective view of a tenth embodiment of the present invention.

FIG. 17 is a graph of reproduction output from the ring type magnetic head unit in the first embodiment of the present invention.

FIG. 18 is a graph of reproduction output from the single magnetic pole type magnetic head unit according to the first embodiment of the invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Substrate 2 ... In-plane anisotropic film 3 ... Vertical anisotropic film 4 ... Main magnetic pole 5 ... Core 6,7 ... Coil 8 ... Magnetic disk 9 ... Ring type magnetic head part 10 ... Single magnetic pole type magnetic head part 12 ... MR film 13, 14 ... Shield film 15 ... Gap 16 ... Film thickness

Claims (3)

[Claims] 1. A magnetic film having anisotropy in the direction perpendicular to the recording medium surface, a magnetic film having anisotropy in the in-plane direction of the recording medium surface, and a magnetic film having soft magnetic characteristics at the same time. And a magnetic head for recording / reproducing on / from a magnetic film having anisotropy in the direction perpendicular to the recording medium surface, and magnetic having anisotropy in the in-plane direction of the recording medium surface. A magnetic recording / reproducing apparatus comprising: a magnetic head for recording / reproducing on / from a film; and a control circuit for recording / reproducing a servo signal on at least one of the magnetic films. . 2. The magnetic recording / reproducing apparatus according to claim 1, wherein the distance from the surface of the magnetic disk to the magnetic film having soft magnetic characteristics is 0.2 μm or less. 3. A magnetic film having anisotropy in the direction perpendicular to the recording medium surface, a magnetic film having anisotropy in the in-plane direction of the recording medium surface, and a magnetic film having soft magnetic characteristics at the same time. A magnetic disk, a magnetic head for recording on a magnetic film having anisotropy in the direction perpendicular to the recording medium surface, and a magnetic film having anisotropy in the direction perpendicular to the recording medium surface. A magnetoresistive effect type magnetic head for reproducing a recorded signal; a magnetic head for recording / reproducing on / from a magnetic film having anisotropy in the in-plane direction of the recording medium surface; A magnetic recording / reproducing apparatus comprising: a control circuit for recording / reproducing a servo signal for at least one of the two.