JP2001101611A - Magnetic head and magnetic reproducing device - Google Patents

Abstract

[PROBLEMS] To provide a magnetic head and a magnetic reproducing apparatus capable of reducing crosstalk from an adjacent track which accompanies narrowing tracks for higher recording density and obtaining high S / N. The purpose is to provide. SOLUTION: A unique configuration in which magnetic bias applying means is provided on both sides of a magnetic detecting unit such as a magnetic yoke or a magnetic core can surely saturate only a soft magnetic layer on a recording track to be reproduced. That is, since the signal recorded on the recording layer is reproduced while applying a magnetic bias in the track width direction, it is possible to prevent the soft magnetic layer on the adjacent recording track from being unnecessarily saturated. Crosstalk at the time can be greatly reduced, and reproduction with extremely high resolution can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a magnetic head and a magnetic reproducing apparatus. More specifically, the present invention relates to a magnetic head and a magnetic reproducing apparatus capable of narrowing tracks for high recording density by suppressing crosstalk between adjacent tracks.

[0002]

2. Description of the Related Art In a conventional magnetic recording / reproducing system of a longitudinal (in-plane) recording method and a perpendicular recording method, a signal is recorded on a recording medium by using a "ring type magnetic head" or a "single pole type magnetic head" as a recording head. Recording and reproduction were performed using a "ring-type magnetic head" or a "magnetoresistive head" as a reproducing head. However, the improvement in magnetic recording density in recent years has been remarkable, and not only the bit length in the longitudinal direction of the recording track but also the narrowing of the recording track width has been rapidly advanced.

In such a situation, various recording / reproducing head structures have been proposed for adapting to a narrow track. A "plane magnetic core-type ring-type head" and a "plane yoke-type magnetoresistive head" which define the track width by the thickness of the thin film are examples.

However, as the track narrowing progresses, even when a head corresponding to the narrow track as described above is used, the signal recorded on the adjacent track when reproducing the signal recorded on the recording layer of the recording medium is reduced. There is a problem of reproduction.

On the other hand, as a countermeasure on the medium side, a structure has been proposed in which "fringing" at the time of recording / reproducing, that is, "blur" at the boundary of recording bits, is smaller than that of a conventional recording medium. For example, a three-layer medium in which a recording layer, an intermediate layer, and a soft magnetic layer are sequentially stacked, or a two-layer medium in which a recording layer and a soft magnetic layer are sequentially stacked,
Layered media has already been proposed and is commonly known as "keepered media".

FIG. 12 is a schematic cross-sectional view illustrating the layer structure of the “keeped media”. In each of the configurations illustrated in FIGS. 6A to 6F, the recording layer 20 is formed on the substrate 201.
2 and a soft magnetic layer 206 are formed. These recording media are characterized in that "fringing" during recording and reproduction is small and a high S / N is obtained. The reason why the recording / reproducing fringing is small is that the recording layer 20
This is because the magnetic flux in the magnetization transition region of No. 2 returns to the soft magnetic layer 206, so that the demagnetizing field applied to the recording bit decreases and the recording bit stabilizes. In addition, since the transition area is reduced, the linear recording density and the track recording density are improved.

When recording magnetization information on these recording media, a normal "ring-type head" and "single-pole-type head" can be used.

FIGS. 13 (a) and 13 (b) are conceptual diagrams showing the configurations of a "ring type head" and a "single pole type head". That is, the ring-type head 3 shown in FIG.
No. 00 has a configuration in which a recording coil 304 is inserted into a ring-shaped core 302. At the time of recording, a magnetic field generated at the tip of the core 302 magnetically saturates the soft magnetic layer 206 of the medium to form a magnetization saturated portion 206A.
02, a recording bit 202A is formed.

The single pole type head 400 shown in FIG. 13B has a main pole 402 protruding toward the medium and a recording coil 404 crossing the main pole 402. At the time of recording,
The magnetic field emitted from the main pole 402 is applied to the soft magnetic layer 20 of the medium.
6 is magnetically saturated to form a magnetized saturated portion 206A,
A recording bit 202A magnetized in the perpendicular direction is formed in the recording layer 202 therebelow.

Regardless of which head is used, the provision of the soft magnetic layer 206 on the medium causes a "slimming effect" of the recording magnetic field during recording, and the recording with little "fringing" due to the steep recording magnetic field. It can be performed.

[0011]

However, when reproducing the magnetization information recorded on such a keeper medium, the soft magnetic layer 206 on the recording layer 202 must be magnetically saturated. . In the conventional read head, the recording layer 20 is saturated while the soft magnetic layer 206 is saturated.
There is a problem that it is difficult to extract the magnetization information of No. 2 with high sensitivity.

FIG. 14 is a conceptual diagram showing a conventional reproducing method for a keyed medium. That is, in the example shown in FIG. 9A, a bias current is applied to the coil 504 to apply a DC magnetic bias to the ring-shaped core 502, thereby magnetically saturating the soft magnetic layer 206 and magnetizing the soft magnetic layer 206. The saturation portion 206A is formed, and the same ring-shaped core 502 detects magnetization information of the recording layer 202 thereunder.

In the example shown in FIG. 14B, two anisotropic magnetoresistive elements (anisotropic magnets) are used.
A dual AMR (Dual-AMR) head in which etoresistive elements (AMR elements) 602 and 604 are arranged in parallel is used. In this case, the soft magnetic layer 20 is formed using a magnetic field generated by a sense current flowing through the AMR elements 602 and 604.
6 is magnetically saturated to form a magnetization saturated portion 026A,
The magnetization information signal of the recording layer 202 thereunder is detected.

However, when the reproducing method shown in FIG. 14A is adopted, a magnetic DC
The core 502 needs to be continuously biased.
However, there has been a problem that the magnetic permeability of the sample is lowered and the reproduction sensitivity is lowered.

On the other hand, in the case of the reproducing system shown in FIG. 14B, the AMR elements 602 and 604 are provided to extend in the width direction of the recording track. Therefore, the magnetic field caused by the sense current saturates the soft magnetic layers 206 on a large number of tracks in the track width direction. As a result, when the track is narrowed, there is a problem that a signal of an adjacent track is picked up.

As described above, in the combination of a conventional reproducing head and a longitudinal (in-plane) recording medium or a perpendicular recording medium, when the recording density is increased, "fringing" occurs at the time of reproduction, and crossing from an adjacent track occurs. It was difficult to reduce the talk noise and obtain a high S / N.

The present invention has been made based on the recognition of such a problem, and an object of the present invention is to reduce crosstalk from an adjacent track which accompanies narrowing of a track for higher recording density, and to improve the high density. An object of the present invention is to provide a magnetic head and a magnetic reproducing device capable of obtaining an S / N.

[0018]

In order to achieve the above object, a magnetic head according to the present invention is a reproducing magnetic head for detecting magnetization information stored in a recording track of a recording medium, wherein the magnetic information is read. A detecting unit for detecting, and a pair of magnetic bias applying units provided on both sides of the detecting unit in a width direction of the recording track as viewed from the detecting unit, wherein the magnetic bias applying unit is provided with respect to the recording medium. A magnetic bias in the width direction of the recording track can be applied.

In particular, if the distance between the pair of magnetic bias applying means is set to be equal to or less than the width of the recording track, it is possible to reliably prevent the soft magnetic film on the adjacent track from being saturated.

More specifically, in the configuration of the magnetic head of the present invention, the detecting section includes a ring-shaped magnetic core having a magnetic gap at a tip end extending toward the recording medium; An excitation coil provided crosswise;
Wherein the pair of magnetic bias applying means are provided on both sides of the magnetic gap.

In a preferred embodiment of the magnetic head according to the present invention, the ring-shaped magnetic core is formed in the same plane substantially parallel to the substrate surface.

Alternatively, the detection unit may be a pair of magnetic yokes facing each other via a magnetic gap provided at a tip end extending toward the recording medium, and may be magnetically coupled to each of the pair of magnetic yokes. A magnetoresistive effect element,
A pair of electrodes provided at both ends of the magnetoresistive element, and the pair of magnetic bias applying means are provided on both sides of the magnetic gap.

Further, as a preferred embodiment of the magnetic head of the present invention, a pair of magnetic yokes formed in the same plane substantially parallel to the substrate surface and opposed via a magnetic gap, a magnetization fixed layer and a magnetization free layer, and A spin valve type magnetoresistive element comprising a non-magnetic intermediate layer provided between the spin valves, wherein the spin valve type magnetoresistive element is disposed so as to be magnetically coupled to the pair of magnetic yokes. A pair of electrodes are arranged at both ends of the magnetic yoke, and magnetic bias applying means capable of applying a magnetic bias in the track width direction via a magnetic gap is provided on an upper surface portion and a lower surface portion in the thickness direction of the magnetic yoke. And

On the other hand, a magnetic reproducing apparatus of the present invention includes any one of the magnetic heads described above, and includes at least a soft magnetic layer and a magnetic recording layer for storing the magnetization information. Is magnetically saturated by a magnetic bias applied by the magnetic bias applying means, and the magnetization information stored in the recording layer can be detected by the detection unit.

Alternatively, a magnetic reproducing apparatus according to the present invention comprises a recording head for recording a signal and a magnetic recording layer in which a non-magnetic intermediate layer and a soft magnetic layer are sequentially laminated on a substrate. A magnetic recording / reproducing device having a magnetic recording / reproducing head having a reproducing head for reproducing a signal recorded on a recording medium, wherein a signal recorded on a recording layer while applying a magnetic bias in a track width direction. Is reproduced.

According to the configuration described above, the reproduction signal from the recording layer can be extracted by saturating the soft magnetic layer of the recording medium by the magnetic bias applying means. As the magnetic bias applying means, a magnetic bias mechanism in which a soft magnetic film is magnetized and fixed with an antiferromagnetic film, or a mechanism in which a magnetic bias is applied by a magnetomotive force generated by a coil current, such as a pseudo recording ring core, or There is a mechanism for applying a magnetic bias using a hard magnetic material.

Further, the above magnetic bias applying means includes:
It can also serve as a magnetic shield.

[0028]

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

FIG. 1 is a perspective view conceptually showing the structure of a reproducing magnetic head of the present invention.

FIG. 2 is a conceptual sectional view along the longitudinal direction of a recording track when the reproducing magnetic head of the present invention is applied to a longitudinal (in-plane) recording medium.

FIG. 3 is a conceptual sectional view along the recording track width direction when the reproducing magnetic head of the present invention is applied to a longitudinal (in-plane) recording medium.

The magnetic head 10 of the present invention includes a pair of magnetic yokes 12 and 12 facing a medium 200, a detecting element 14 arranged to be magnetically coupled to the magnetic yoke,
A pair of electrodes 16, 16 installed at both ends of the detection element,
Magnetic bias portions 18 provided on both sides of the magnetic yoke in the recording track width direction and capable of applying a magnetic bias.
Is provided. The pair of magnetic yokes 12 has a reproducing magnetic gap 13 at a predetermined interval at a front end portion facing the medium.

The detecting element 14 detects the magnetization information held in the medium 200, converts it into an electric signal and outputs it. As a specific example, for example, GMR (giant magn)
etoresistive) element or TMR (tunneling magnetoresis)
tive) element, a high-sensitivity reproduction can be realized.

The magnetic yoke 12 is a single-layer film made of a soft magnetic material such as a NiFe alloy or an amorphous CoZrNb alloy,
Alternatively, a laminated film of these soft magnetic films, a laminated film of these soft magnetic films and a non-magnetic intermediate layer, or a laminated film of these soft magnetic materials and an antiferromagnetic film such as IrMn or PtMn. Be composed. The magnetic anisotropy of the magnetic yoke 12 is controlled to be unidirectional or isotropic.

As the detection element 14, a spin valve element including a pinned layer, a free layer, and a nonmagnetic intermediate layer sandwiched between them can be used. A spin valve element 14 used as a detection element is magnetically coupled to the magnetic yoke 12. When the material of the magnetic yoke 12 has conductivity, it is necessary to form an insulating layer (not shown) between the magnetic yoke 12 and the spin valve element 14. For this reason, both are in an indirect magnetic coupling state, that is, a magnetostatic coupling state.

The magnetic yoke 12 is made of Co-Al-O,
A granular magnetic film such as FeCo-Al-O or F
In the case where the spin valve element 14 is made of a non-conductive material such as soft magnetic ferrite made of e-Co-O, the spin valve element 14 is arranged so as to be directly exchange-coupled to the magnetic yoke 12.

The term "granular magnetic film" as used herein means a thin film made of a material having a granular structure composed of magnetic metal fine particles and a nonmagnetic material surrounding the magnetic metal fine particles. CoF
It has a structure in which magnetic particles made of e (cobalt iron) or the like are dispersed. The particle size of the magnetic particles is, for example, several nanometers to
It can be about several tens of nanometers.

Since the magnetic flux entering the spin valve element 14 largely depends on the magnetic spacing between the magnetic yoke 12 and the spin valve element 14, the magnetic gap 13 is preferably as small as possible.
It is desirable that it is not more than μm.

The magnetic bias section 18 is disposed on both sides of the reproducing magnetic gap 13 with the magnetic yoke 12 via a magnetic gap. That is, the magnetic bias unit 18 is arranged so as not to be magnetically coupled to the magnetic yoke 12. Further, the magnetic bias unit 18 can also function as a “magnetic shield”. Magnetic bias section 18
Consists of a hard magnetic film, a laminated film of an antiferromagnetic film and a soft magnetic film, or a type in which a magnetic field is generated by magnetizing a core by a coil current. Is applied. The magnetic bias applied by the magnetic bias unit 18 may be DC (DC) or AC (A
C) or a high frequency magnetic bias.

According to the present invention, the unique configuration in which the magnetic bias portions 18 are provided on both sides of the magnetic yoke 12 allows the soft magnetic layer 206 on the recording track to be reproduced as shown in FIG. Only can be reliably saturated. That is, by applying a magnetic bias between the pair of magnetic bias portions 18 as shown by the arrow M in FIG. 3, only the soft magnetic layer of the recording track to be reproduced immediately below the magnetic yoke 12 is selectively formed. And the magnetization information S of the recording layer 202 thereunder can be detected. The width Tw of the recording track is about 0.5 μm, and it is easy to arrange the magnetic bias portions 18 at such intervals.

When a magnetic bias is applied by the magnetic bias unit 18 arranged as described above, it is possible to prevent the soft magnetic layer on the adjacent recording track from being unnecessarily saturated. As a result, crosstalk during reproduction is significantly reduced, and reproduction with extremely high resolution can be realized.

Next, a more specific configuration of the magnetic head of the present invention will be described by way of example.

FIG. 4 shows a specific example of the reproducing magnetic head of the present invention, and is a perspective view seen from the medium facing surface. In this figure, the parts described above with reference to FIGS. 1 to 3 are denoted by the same reference numerals, and detailed description is omitted.

The magnetic head shown in FIG. 4 is composed of Al ₂ O ₃ -T
It is formed on a substrate 11 made of iC / Al ₂ O ₃ (an aluminum oxide layer is laminated on an AlTiC). Substrate 1
A first layer magnetic bias portion 18 is patterned and formed on 1, and its periphery is buried with an insulating layer 15.
A magnetic yoke 12 is formed thereon with a predetermined gap therebetween.
3 is also buried with an insulator. An excitation coil 19 is provided between magnetic bias units 18 provided above and below the magnetic yoke 12. When a bias current flows through the exciting coil 19, a magnetic bias is generated between the magnetic bias portions 18, 18, and a magnetic bias can be applied in the recording track width direction immediately below the magnetic yoke 12.

Next, the intensity of the bias magnetic field applied by the magnetic bias unit 18 of the present invention will be described in detail.

FIG. 5 is a conceptual diagram for explaining the dimensional relationship in the sectional direction shown in FIG. That is, the thickness of the magnetic bias portion 18 and the magnetic yoke 12 in the track width direction and the saturation magnetization per unit volume (in the case of using a hard magnetic film, replace the residual magnetization Mr per unit volume) with t ₁ , respectively. _Let t _y , M _s1 and M _sy . The distance between the magnetic bias portion 18 and the magnetic yoke 12 is g, the distance from the medium surface of the read head is h, the thickness of the soft magnetic layer 206 of the recording medium 200 is t ₂ , and the saturation magnetization thereof is M _s2 .
Further, an x-axis and a y-axis coordinate system are defined in each illustrated direction.

First, the magnetic field intensity exerted on the recording medium 200 by the magnetic bias unit 18 will be roughly estimated. Since the magnetic bias portion 18 is magnetized perpendicular to the medium surface, it is assumed that magnetizations having different positive and negative polarities are uniformly distributed at its tip. Since the magnetic bias unit 18 is magnetized in one direction, the magnetization L represented by the following equation at the tip of the magnetic bias unit is distributed. L = B = 4πM _s1 .

Here, B represents a magnetic flux from the magnetic bias unit. In this case, the magnetic field H _x exerted from the tip of the magnetic bias of the x-direction at a certain coordinate point (x, y) is
It is given by the following equation. _{H x = H 0 · 2 /} {πcot -1 (2 · y / G)} Here, a _{G = 2g + t y, H} 0 is H ₀ = L / (2 · in magnetic field at x = y = 0 u ₀ ).

Since the soft magnetic layer 206 of the medium is a thin film, the demagnetizing field is large in the film thickness direction, and it is difficult to saturate the medium. Therefore, to saturate the soft magnetic layer 206, it is necessary to apply a magnetic field in the x direction.

In order to saturate the upper soft magnetic layer 206 of the medium in the film thickness direction, the following condition may be satisfied.

That is, assuming that the susceptibility of the soft magnetic layer 206 in the x direction is A _x , the magnetization G of the soft magnetic layer 206 is given by the following equation.

G = 4π · M _s2 = A _x · H Therefore, the condition for the soft magnetic layer 206 to saturate in the x direction is given by the following equation. G ≦ A _x · H (1) On the other hand, when the soft magnetic layer 206 is magnetized, positive and negative magnetizations are generated at both ends, and a demagnetizing field _Hd is generated. The demagnetizing field _Hd is given by the following equation. H _d = −N · G Here, N is a demagnetizing field coefficient, which depends on the thickness of the soft magnetic layer 206, the magnetization pattern, and the like. Therefore, the magnetic field H is given by the following equation. _{H = H x -N · G (} 2) above (1) and from (2) the following equation relationships can be obtained. G ≦ H _x · A _x / (1 + N · A _x ) That is, assuming that the desired track width is W and the center of the track width is x = 0, the magnetic field H _x at the position of x = W / 2 is It is only necessary to satisfy the relational expression.

That is, the pair of magnetic bias units 18, 18
If the range bias magnetic field H _x is in the above equation generated by, as shown in FIG. 3, certainly saturate only the soft magnetic layer 206 corresponding to the recording track directly under the magnetic yoke 12, the crosstalk High-sensitivity reproduction can be realized while suppressing this.

FIG. 6 is a conceptual sectional view along the longitudinal direction of a recording track when the reproducing magnetic head of the present invention is applied to a perpendicular recording medium.

FIG. 7 is a conceptual sectional view along the recording track width direction when the reproducing magnetic head of the present invention is applied to a perpendicular recording medium.

In FIGS. 6 and 7, the same parts as those described above with reference to FIGS. 1 to 5 are denoted by the same reference numerals, and detailed description thereof will be omitted.

As shown in these drawings, the magnetic head of the present invention ensures that only the soft magnetic layer 206 on the recording track to be reproduced is saturated and the recording layer 202 under the magnetic recording layer 202 is reproduced even in a perpendicular recording medium. The magnetization information S can be detected. That is, crosstalk from adjacent recording tracks is prevented, and reproduction with extremely high resolution can be realized.

When the areal recording density of the medium is 40 GBPSI (gigabit / (inch) ² ) or more, when the conventional longitudinal recording method is used, magnetically recorded data disappears due to heat. There is a high possibility that a so-called thermal disturbance problem will become apparent. In this regard, the perpendicular recording method is advantageous.

That is, the resistance of the medium to thermal disturbance is:
It is proportional to the product of the magnetic anisotropy energy Ku per unit volume and the particle volume V. In order to increase the linear recording density in the longitudinal recording method, it is necessary to reduce the thickness of the medium in order to reduce the demagnetizing field of the magnetized medium. Then, the volume V is reduced, and the thermal agitation resistance is reduced. Ku is increased in order to avoid this, but then the coercive force increases and recording becomes difficult.

On the other hand, in the case of the perpendicular recording method, since the magnetization direction is in the thickness direction of the medium, it is not necessary to reduce the thickness of the medium. , It is easy to achieve higher density.

According to the present invention, it is possible to easily and surely prevent crosstalk between adjacent tracks during reproduction even for a perpendicular recording medium which is advantageous in increasing the recording density. This can greatly contribute to the realization of high density.

The magnetic head of the present invention is not limited to a magnetic head using a detecting element such as a spin valve element.

FIG. 8 is a perspective view showing a schematic structure of a reproducing magnetic head having a detection coil. About the figure,
The same parts as those described above with reference to FIGS. 1 to 7 are denoted by the same reference numerals, and detailed description thereof will be omitted. The magnetic head 20 shown in FIG. 1 has a ring-shaped magnetic core 22 and a detection coil 24 provided so as to cross the magnetic core 22. A pair of magnetic bias parts 18 are provided on both sides of the magnetic gap at the tip of the magnetic core 22. The magnet 22 and the magnetic bias unit 18 have a predetermined gap so as not to be magnetically coupled.

Even in such a magnetic head 20, it is possible to reliably saturate only the soft magnetic layer on the recording track to be reproduced and detect the magnetization information of the recording layer thereunder. That is, crosstalk from adjacent recording tracks is prevented, and reproduction with extremely high resolution can be realized.

Next, the magnetic reproducing apparatus according to the present invention will be described. The magnetic head of the present invention described with reference to FIGS. 1 to 8 can be incorporated in, for example, a recording / reproducing integrated magnetic head assembly and mounted on a magnetic reproducing apparatus.

FIG. 9 is a perspective view of an essential part illustrating a schematic configuration of such a magnetic recording apparatus. That is, the magnetic recording / reproducing device 150 of the present invention is a device using a rotary actuator. In the figure, a magnetic disk 200 for longitudinal recording or perpendicular recording has a spindle 15
2 and is rotated in the direction of arrow A by a motor (not shown) which responds to a control signal from a drive controller (not shown). The magnetic disk 200 has a configuration of “keeped media” having a recording layer for longitudinal recording or perpendicular recording, and a soft magnetic layer laminated thereon. In the magnetic disk 200, a head slider 153 for recording and reproducing information stored in the magnetic disk 200 is attached to a tip of a thin-film suspension 154. here,
The head slider 153 has, for example, the magnetic head according to any of the above-described embodiments mounted near the tip thereof.

When the magnetic disk 200 rotates, the medium facing surface (ABS) of the head slider 153 is held at a predetermined flying height from the surface of the magnetic disk 200.

The suspension 154 is connected to one end of an actuator arm 155 having a bobbin for holding a drive coil (not shown). The other end of the actuator arm 155 is provided with a voice coil motor 156, which is a type of linear motor. The voice coil motor 156 includes a drive coil (not shown) wound around a bobbin portion of the actuator arm 155, and a magnetic circuit including a permanent magnet and an opposing yoke, which are opposed to each other so as to sandwich the coil.

The actuator arm 155 has a fixed shaft 1
It is held by ball bearings (not shown) provided at two positions above and below 57, and can be freely rotated and slid by a voice coil motor 156.

FIG. 10 is an enlarged perspective view of the magnetic head assembly from the actuator arm 155 as viewed from the disk side. That is, the magnetic head assembly 1
Numeral 60 has an actuator arm 151 having a bobbin for holding a drive coil, for example. A suspension 154 is connected to one end of the actuator arm 155.

A head slider 153 having one of the reproducing magnetic heads described above with reference to FIGS. 1 to 8 is attached to the tip of the suspension 154.
A recording head may be combined. Suspension 1
54 is a lead wire 16 for writing and reading signals.
4, the lead wire 164 and the head slider 153.
Are electrically connected to the respective electrodes of the magnetic head incorporated in the device. In the figure, 165 is a magnetic head assembly 160
Electrode pads.

Here, between the medium facing surface (ABS) of the head slider 153 and the surface of the magnetic disk 200,
A predetermined flying height is set.

FIG. 11A is a conceptual diagram showing the relationship between the head slider 153 and the magnetic disk 200 when the flying height is a predetermined positive value. As illustrated in the figure, usually, in many magnetic recording devices, the slider 153 on which the magnetic head 10 is mounted operates while flying above the surface of the magnetic disk 200 by a predetermined distance. In the present invention, even in such a "flying traveling" type magnetic recording apparatus, reproduction with higher resolution and lower noise than before can be performed. That is, by employing any one of the magnetic heads described above with reference to FIGS. 1 to 8, only the soft magnetic layer on the track to be reproduced can be surely saturated and the magnetization information of the recording layer thereunder can be reproduced. it can. That is, since crosstalk from adjacent recording tracks can be greatly reduced, the track pitch can be reduced, and the recording density can be greatly improved.

On the other hand, when the recording density is further increased, it is necessary to read the information by lowering the flying height and gliding closer to the magnetic disk 200. For example, in order to obtain a recording density of about 40 G (giga) bits per square inch, the spacing loss due to flying is too large, and the head 10 and the magnetic disk 200 crash due to extremely low flying. Problem cannot be ignored.

For this reason, a system in which the magnetic head 10 and the magnetic disk 200 are made to travel while being positively contacted with each other in reverse is also conceivable.

FIG. 11B is a conceptual diagram showing the relationship between such a “contact traveling type” head slider 153 and the magnetic disk 200. Also in the magnetic head of the present invention, DLC (Diamond-Like-Carbon) is provided on the contact surface with the medium.
By providing a lubricating film or the like, it can be mounted on a “contact traveling type” slider. Therefore, FIG.
In the "contact running type" magnetic reproducing apparatus as exemplified in the above, recording / reproducing of a medium having a higher density by greatly reducing crosstalk from an adjacent track and significantly reducing a track pitch as compared with the related art. Can be performed stably.

The embodiments of the present invention have been described with reference to the examples. However, the present invention is not limited to these specific examples. For example, a medium that can be used as a recording medium is not limited to those illustrated in FIGS. 12A to 12F, and any medium having a recording layer and a soft magnetic layer can be used in the same manner. It works.

Further, the materials and shapes of the respective elements constituting the magnetic head are not limited to those described above as specific examples, and the same effects can be obtained by similarly using the entire range that can be selected by those skilled in the art. I can play.

Further, the magnetic reproducing device may be one that performs only reproduction or one that performs recording / reproduction. The medium is not limited to a hard disk, but may be a flexible disk or a magnetic card. It is possible to use any magnetic recording medium such as. Further, the apparatus may be a so-called "removable" type apparatus in which the magnetic recording medium is removable from the apparatus.

[0080]

The present invention is embodied in the above-described embodiment and has the following effects.

First, according to the present invention, only a soft magnetic layer on a recording track to be reproduced is ensured by a unique configuration in which magnetic bias applying means is provided on both sides of a magnetic detecting unit such as a magnetic yoke or a magnetic core. Can be saturated. That is, it is possible to prevent the soft magnetic layer on the adjacent recording track from being unnecessarily saturated, and as a result, it is possible to significantly reduce crosstalk during reproduction and realize reproduction with extremely high resolution.

According to the present invention, by greatly improving the reproduction resolution in this way, the track pitch of the medium can be greatly reduced, and the recording density can be greatly improved.

Further, according to the present invention, the magnetic bias applying means can also act as a magnetic shield, effectively shut off the magnetization information from the adjacent track, further improve the reproduction resolution, and achieve a very high reproduction resolution. A reproduction S / N ratio can be obtained.

As described above, according to the present invention,
When the track is narrowed, crosstalk noise from an adjacent track or recording fringing, which cannot be avoided by the conventional recording / reproducing system, can be reduced, and an improvement in S / N can be expected. It is possible to provide a magnetic head and a magnetic reproducing device that can respond,
The industrial benefits are enormous.

[Brief description of the drawings]

FIG. 1 is a perspective view conceptually showing a configuration of a reproducing magnetic head of the present invention.

FIG. 2 is a conceptual sectional view taken along the longitudinal direction of a recording track when the reproducing magnetic head of the present invention is applied to a longitudinal (in-plane) recording medium.

FIG. 3 is a conceptual cross-sectional view along a recording track width direction when the reproducing magnetic head of the present invention is applied to a longitudinal (in-plane) recording medium.

FIG. 4 is a specific example of a reproducing magnetic head of the present invention, and is a perspective view as viewed from a medium facing surface.

FIG. 5 is a conceptual diagram for explaining a dimensional relationship in a sectional direction shown in FIG. 3;

FIG. 6 is a conceptual sectional view along the longitudinal direction of a recording track when the reproducing magnetic head of the present invention is applied to a perpendicular recording medium.

FIG. 7 is a conceptual sectional view along the recording track width direction when the reproducing magnetic head of the present invention is applied to a perpendicular recording medium.

FIG. 8 is a perspective view illustrating a schematic structure of a reproducing magnetic head including a detection coil.

FIG. 9 is a perspective view of an essential part illustrating a schematic configuration of a magnetic reproducing apparatus of the present invention.

FIG. 10 is an enlarged perspective view of the magnetic head assembly ahead of the actuator arm 155 as viewed from the disk side.

11A is a conceptual diagram illustrating a relationship between a head slider 153 and a magnetic disk 200 when a flying height is a predetermined positive value, and FIG. 11B is a conceptual diagram illustrating a “contact traveling type” head slider. FIG. 15 is a conceptual diagram illustrating a relationship between the magnetic disk 200 and the magnetic disk 200.

FIG. 12 is a schematic cross-sectional view illustrating a layer configuration of “keeped media”.

FIGS. 13A and 13B are conceptual diagrams showing the configuration of a “ring-type head” and a “single-pole-type head”.

FIG. 14 is a conceptual diagram showing a conventional reproduction method for a kept medium. FIG. 1 is a perspective view conceptually showing a configuration of a magnetoresistive head according to a first embodiment of the present invention, and also showing a relationship with a recording medium.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10, 20 Magnetic head 11 Substrate 12 Magnetic yoke 13 Magnetic gap 14 Detecting element 15 Insulating layer 16 Electrode 18 Magnetic bias part (magnetic bias applying means) 19 Excitation coil 22 Magnetic core 24 Coil 150 Magnetic recording / reproducing device 152 Spindle 153 Head slider 154 Suspension 155 Actuator arm 156 Voice coil motor 160 Magnetic head assembly 200 Medium (magnetic recording disk) 201 Substrate 202 Recording layer 202A Recording bit 204 Intermediate layer 206 Soft magnetic layer 206A Magnetization saturation section 300, 400, 500, 600 Magnetic head 302 Magnetic core 304 coil 402 main magnetic pole 404 coil 502 magnetic core 504 coil 602, 604 AMR element 604

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Yuichi Osawa 72 Horikawa-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Prefecture Inside the Toshiba Kawasaki Works Co., Ltd. 72 Toshiba Kawasaki Works, Inc. (72) Inventor Akio Hori 72 Toshiba, Kawasaki Works, Kawasaki City, Kanagawa Prefecture 72 Toshiba Kawasaki Works, Ltd. No. 72 F-term in Toshiba Kawasaki Office (reference)

Claims (4)

[Claims] 1. A reproducing magnetic head for detecting magnetization information stored in a recording track of a recording medium, comprising: a detection unit for detecting the magnetization information; and a width direction of the recording track as viewed from the detection unit. A pair of magnetic bias applying means provided on both sides of the detection unit, wherein the magnetic bias applying means is capable of applying a magnetic bias in a width direction of the recording track to the recording medium. Magnetic head. 2. The detecting section comprises: a ring-shaped magnetic core having a magnetic gap at a tip end extending toward the recording medium; and an exciting coil provided to cross the magnetic core. 2. The magnetic head according to claim 1, wherein the pair of magnetic bias applying units are provided on both sides of the magnetic gap. 3. A pair of magnetic yokes facing each other via a magnetic gap provided at a tip end extending toward the recording medium, and a magnetic coupling with each of the pair of magnetic yokes. And a pair of electrodes provided on both ends of the magnetoresistive element, wherein the pair of magnetic bias applying means are provided on both sides of the magnetic gap. 2. The magnetic head according to claim 1, wherein: 4. The recording medium according to claim 1, further comprising: a soft magnetic layer; and a magnetic recording layer for storing the magnetization information. A magnetic reproducing apparatus, wherein the magnetic information stored in the recording layer can be detected by the detection unit while being magnetically saturated by a magnetic bias applied by a magnetic bias applying unit.