JP3135632B2 - Magnetic head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head, and more particularly to a magnetic head suitable for performing track alignment and azimuth adjustment of a recording / reproducing magnetic head.

[0002]

2. Description of the Related Art In recent years, demands for improving the recording density of a magnetic recording / reproducing apparatus have been increasing. In order to improve recording density, track density and linear density are required to be improved.
A narrow track is also required. As a magnetic recording medium, not only a normal in-plane recording medium but also a perpendicular recording medium and an oblique recording medium are used. In such a situation, stricter alignment of the recording / reproducing magnetic head with respect to the track on the magnetic recording medium (hereinafter, referred to as track alignment) and azimuth adjustment are required. A specific magnetic head is used for detecting a track shift and an azimuth shift required for the track alignment and the azimuth adjustment.

FIG. 25 shows an example of a conventional magnetic head having a track deviation detecting function using two inductive heads, and magnetic cores 101 and 102 made of a soft magnetic material.
Are arranged on the left and right in the direction of the track width (indicated by W) on the magnetic recording medium, and coils 103 and 104 are wound around these magnetic cores 101 and 102, respectively. Assuming that the outputs of the inductive heads are V1 and V2, when the head is located directly above the track, V1−V2 = 0, but the head is displaced from directly above the track. In this case, V1−V2 ≠ 0. Therefore, the outputs V1 and V
A track shift can be detected by an envelope difference of 2 and an azimuth can be detected by a phase difference.

[0004] However, as shown in FIG.
In a configuration in which two inductive heads having coils 103 and 104 wound around 102 are arranged adjacent to each other, coils 103 and 10
Since it is necessary to secure a space for winding the head 4, the size of the head in the track width direction increases, which is not suitable for narrowing the track.

On the other hand, as a magnetic head which does not require a coil, there is a so-called MR head using a magnetic film (MR film) having a magnetoresistance effect. FIG. 26 shows a so-called yoke type MR head configured to guide a leakage magnetic flux from a magnetic recording medium to an MR film using a yoke (magnetic core). The MR head is provided with a lower core 201, an upper core 203 and 204 disposed on the lower core 201 with a recording / reproducing gap 202 interposed therebetween, and an upper core 20.
3 and 204, an MR film 205 and an MR film 2
05 are connected to the electrodes 206 and 207 at both ends.

FIG. 27 shows a shield type MR head having a function of shielding the MR film. In FIG. 27A, the MR film 205 and the magnetic core 208 and 209 are located between the leading ends of the recording / reproducing gap. The tips of the electrodes 206 and 207 are arranged, and in FIG.
The MR film 205 and the electrodes 206 and 207 are arranged between one of the members 208 and the newly provided shield plate 200. In the case of FIG. 27B, the recording gap is formed between the tips of the magnetic cores 208 and 209, and the reproducing gap is formed between the magnetic core 208 and the shield plate 200.

[0007]

As described above, in a magnetic head provided with two inductive heads adjacent to each other in the track width direction for detecting a track shift or an azimuth shift, a space for winding a coil is provided. Therefore, there is a problem that the size of the head in the track width direction becomes large, which is not suitable for narrowing the track.

An object of the present invention is to solve such a conventional problem and to provide a magnetic head for detecting a track shift and an azimuth shift with high sensitivity even when the track is narrowed.

[0009]

According to a first aspect of the present invention, there is provided a magnetic head comprising: a magnetic film having a magnetoresistive effect disposed substantially parallel to a track width direction of a magnetic recording medium; At least a pair of current supply electrodes provided in contact with both ends in the track width direction or in the vicinity thereof, and provided between the current supply electrodes in contact with the magnetic film, and having a smaller width than the current supply electrodes. And at least one signal detection electrode. The total width of at least one signal detection electrode is preferably equal to or less than one third of the track width.

The magnetic head may further include a magnetic core for guiding a leakage magnetic flux from the magnetic recording medium to the magnetic film. It is preferable that at least a portion of the magnetic core close to the magnetic film is magnetically separated into a plurality in the track width direction.

A magnetic head according to a second aspect of the present invention comprises:
The first and second magnetic detecting elements are separated from each other in the track width direction of the magnetic recording medium, and each of the first and second magnetic detecting elements is substantially parallel to the track longitudinal direction of the magnetic recording medium. And a magnetic film having a magnetoresistive effect and at least a pair of electrodes provided in contact with both ends of the magnetic film in the track longitudinal direction or in the vicinity thereof. Further, in this magnetic head, a magnetic core for guiding a leakage magnetic flux from the magnetic recording medium to the magnetic films of the first and second magnetic detecting elements is arranged between the first and second magnetic detecting elements. It is more preferable that at least a portion of the magnetic core close to the magnetic recording medium is magnetically divided into a plurality in the track width direction of the magnetic recording medium.

[0012]

In the magnetic head according to the first aspect of the present invention, a magnetic film (MR film) having a magnetoresistive effect is arranged in the track width direction, and a constant current is supplied to the MR film by a current supply electrode. Signal detection electrodes can detect signals with a voltage difference corresponding to track deviation and azimuth deviation, eliminating the need to wind a coil as in an inductive head and allowing two heads to be adjacent in the track direction. Since there is no need, the size of the head in the track width direction (particularly, the width of the sliding surface to the recording medium) is reduced.

Moreover, in the present invention, the width of the signal detection electrode is made smaller than the width of the current supply electrode, so that the area for sensing the magnetic flux leakage from the magnetic recording medium is increased. Therefore, even when the track of the magnetic recording medium is narrowed, a track shift and an azimuth shift are detected with high sensitivity.

Further, the magnetic flux leakage from the magnetic recording medium
At least a portion of the magnetic core for leading to the film, which is close to the magnetic recording medium, is magnetically divided into a plurality of pieces in the track width direction, so that the magnetic flux leakage from the left and right sides of the track is separated and guided to the MR film. Therefore, a track shift and an azimuth shift can be detected with higher sensitivity.

In the magnetic head according to the second aspect of the present invention, the first and second magnetic heads are constituted by an MR film arranged substantially parallel to the longitudinal direction of the track and at least a pair of electrodes arranged in contact with the MR film. The detection elements are spaced apart in the track width direction, and the first and second magnetic detection elements can detect a signal having a voltage difference or a current difference corresponding to a track shift or an azimuth shift. Since there is no need to wind a coil around the magnetic sensing element as in an inductive head, the dimension of the entire head in the track width direction is reduced. In addition, since the MR film is arranged substantially in parallel with the longitudinal direction of the track, there is basically no limit on the dimension in this direction, so that a large area for sensing the magnetic flux leakage from the magnetic recording medium is secured. . Therefore, even when the track is narrowed, a track shift and an azimuth shift are detected with high sensitivity.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. First, a magnetic film (MR film) having a magnetoresistance effect
An embodiment of a magnetic head in which are arranged in the track width direction of a magnetic recording medium will be described. 1 to 14 are diagrams showing the embodiment. FIGS. 1A and 1B are perspective views of a magnetic head according to a first embodiment of the present invention, and FIG. 2 is a plan view of the vicinity of an MR film which is a main part thereof.

First, in the magnetic head shown in FIG. 1A, a lower core 11 made of a soft magnetic material and an upper core 13 (14) are arranged with a gap 12 therebetween. An MR film 1 interposed between and substantially parallel to the track width direction of a magnetic recording medium (not shown)
5, a pair of current supply electrodes 16, 17 provided at both ends of the MR film 15 in the track width direction, and an intermediate portion between the current supply electrodes 16, 17 provided in contact with the MR film 15. And a signal detection electrode 18. Here, the width of the signal detection electrode 18 is formed smaller than the width of each of the current supply electrodes 16 and 17.

On the other hand, the magnetic head shown in FIG. 1 (b) has a lower core 11 made of a soft magnetic material and an upper core 11 made of a soft magnetic material, which is arranged through a gap 12 and is divided into two parts. 13, 14 and the upper cores 13 and 14, being substantially parallel to the track width direction of the magnetic recording medium (not shown) so as to be sandwiched between the lower core 11 and the upper cores 13 and 14. The disposed MR film 15 and the MR film 15
And a pair of current supply electrodes 16 and 17 provided in contact with both ends in the track width direction.
The signal detecting electrode 18 is provided between the electrodes 7 in contact with the MR film 15. (B), the signal detection electrode 1
The width of 8 is the same as that of FIG.
7 are formed narrower than the respective widths.

In the magnetic head configured as described above, when the tips of the upper core 13 and the lower core 11, which are the magnetic cores, face the magnetic recording medium, the leakage magnetic flux due to the signal recorded on the track of the magnetic recording medium is reduced. Core 11, 1
The magnetic flux flows into the MR film 15 through 3 and 14, and the electric resistance of the MR film 15 changes according to the amount of magnetic flux. Here, a constant DC current is applied through the current supply electrodes 16 and 17 to the MR film 1.
5 to detect voltages V1 and V2 between the current supply electrodes 16 and 17 and the signal detection electrode 18. The track deviation due to the envelope difference between these voltages V1 and V2 is
Further, azimuth deviation can be detected by the phase difference, and the track alignment and azimuth adjustment of the recording / reproducing magnetic head can be performed using these detection signals.

In this case, the portion of the MR film 15 to which the signal detecting electrode 18 is in contact has a change in electrical resistance of the voltage V
1, a so-called dead zone that does not contribute to V2. FIG.
Shows the relationship between the track deviation of the head and the envelope difference between the voltages V1 and V2. In FIG. 28, the track width is indicated by TW, and the width of the dead zone is indicated by β. At the time of head track alignment, servo control is performed so that this envelope difference, that is, the position signal becomes zero.

At this time, the higher the S / N of the position signal, the higher the positioning accuracy with respect to the track. Also, the wider the linear range of the position signal with respect to the track center, the higher the stiffness against disturbance and the smaller the positioning error. However, as the width β of the dead zone increases, the S / N of the position signal decreases and, as can be seen from FIG. 28, the linear range of the position signal decreases. β = TW
With / k, only a narrow linear range of 1-1 / k is obtained with respect to the linear range obtained when β = 0 (k = ∞).

It has been empirically determined that the linear range should be at least 2/3 of the track width TW in order to perform good servo control, and the width of the dead zone β, that is, the width of the signal detecting electrode 18 should be at least. It must be reduced to less than 1/3 of the track width TW. Also, in the detection of the azimuth deviation, it is preferable that the width of the signal detection electrode 18 be narrow in order to increase the S / N and perform the detection with high sensitivity.

The lower core 11 or the upper core 13,
By connecting a recording thin film coil (not shown) to the magnetic head 14, the magnetic head of this embodiment can be used as a recording / reproducing head. As a reproduction signal, for example, a sum signal of V1 and V2 may be used.

FIG. 3 is a plan view showing the vicinity of the MR film of the magnetic head according to the second embodiment.
The difference from the first embodiment is that only the portion of the film 15 close to the direction M of the magnetic recording medium is brought into contact. According to this embodiment, since the change in the electric resistance of the portion of the MR film 15 where the leakage magnetic flux from the magnetic recording medium flows in a concentrated manner is efficiently detected as the detection signal V1-V2, the track deviation and the azimuth There is an advantage that the displacement can be detected with higher sensitivity.

FIGS. 4 and 5 are a plan view and a sectional view, respectively, showing the vicinity of the MR film of the magnetic head according to the third embodiment. As shown in FIG. An insulating film 19 is interposed between the MR film 15 and the electrode 18 so that only the portion near the direction M of the magnetic recording medium is brought into contact with the magnetic recording medium. According to this embodiment, it is needless to say that the same effect as that of the second embodiment can be obtained.

As shown in FIG. 1B, the same effect can be obtained even if only the end of the signal detecting electrode 18 closer to the magnetic recording medium is made thin. In this case, there is an advantage that the area of the magnetic flux sensing portion can be widened and that the manufacturing is easier than making the entire electrode 18 thin.

FIG. 6 is a plan view showing the vicinity of the MR film of the magnetic head according to the fourth embodiment. An electrode 21 and a second signal detection electrode 22 that is in contact with the portion of the MR film 15 opposite to the direction M of the magnetic recording medium, that is, the portion farthest from the medium, are provided. In this embodiment, the voltages V1, V2 between the current supply electrodes 16, 17 and the first signal detection electrode 21 and the voltage V1, V2 between the current supply electrodes 16, 17 and the second signal detection electrode 22 are set. Are detected.

Here, when the magnetic head is not located directly above the track but is shifted in the track width direction, M
Although the amount of magnetic flux flowing into a portion of the R film 15 between the current supply electrodes 16 and 17 and the first signal detection electrode 21 on the side closer to the direction M of the magnetic recording medium is different, the current supply electrode 1
6, 17 and the amount of magnetic flux flowing into a portion between the second signal detecting electrode 22 far from the magnetic recording medium is substantially equal,
This is half of the amount of magnetic flux flowing into the entire MR film 15. Therefore, by comparing the magnitude of the voltage V1 or V2 with the magnitude of the voltage V3 or V4, it is possible to know whether or not the magnetic head is displaced in the track width direction.

FIG. 7 is a plan view showing the vicinity of the MR film of the magnetic head according to the fifth embodiment.
A plurality of, in this example, four, signal detection electrodes 23 to 26 are arranged symmetrically therebetween. Signal detection electrodes 23 to
The width of each of the electrodes 26 is smaller than the width of each of the current supply electrodes 16 and 17. In this case, a voltage V5 between the signal detection electrodes 23 and 24 when a constant DC current is applied to the MR film 15 via the current supply electrodes 16 and 17;
By detecting the voltage V6 between the signal detection electrodes 25 and 26 and using the voltage difference and the phase difference as detection signals,
Track shift and azimuth shift are detected.

According to this embodiment, the signal detection electrodes 23 to
By arranging 26 at a position where the voltages V5 and V6 are detected with higher sensitivity, it is possible to more sensitively detect a change in magnetic flux flowing from the magnetic recording medium into the MR film 15 as a voltage difference signal between V5 and V6. it can.

FIG. 8 is a plan view showing the vicinity of the MR film of the magnetic head according to the sixth embodiment.
More symmetrically between the signal detection electrodes 31 to 35
Has been arranged. The width of the signal detection electrodes 31 to 35 is smaller than the width of the current supply electrodes 16 and 17. In this case, the voltage V between the electrodes 16 and 31 when a constant DC current flows through the MR film 15 via the current supply electrodes 16 and 17
7. Detecting the voltage V8 between the electrodes 32 and 33, the voltage V9 between the electrodes 33 and 34, and the voltage V10 between the electrodes 35 and 17, and obtaining the voltage difference between V7 and V10, the voltage difference between V8 and V9, and the phase difference. Thus, a track shift and an azimuth shift are detected.

Therefore, according to the present embodiment, the difference between the pair of left and right voltages is obtained finely from the voltage difference between V7 and V10 to the voltage difference between V8 and V9. Can be detected with high sensitivity.

FIG. 9 is a plan view showing the shape of the magnetic core in the magnetic head according to the seventh embodiment.
By separating into two parts denoted by a and 13b,
The structure is such that the leakage magnetic flux flowing from the magnetic recording medium is bisected. Accordingly, the magnetic flux flowing into the MR film 15 is also bisected in the track width direction, so that V1 and V2, V3 and V4, V5 and V6, V7 and V1 described in the above embodiments.
Voltage differences such as 0, V8 and V9 and a phase difference can be detected with higher sensitivity.

FIG. 10 is a plan view showing the shape of the magnetic core in the magnetic head according to the eighth embodiment. The superconducting film 3 is provided between the upper cores 13a and 13b of FIG.
7 are arranged. In this case, since the leakage magnetic flux flowing from the magnetic recording medium flows so as to avoid the superconducting film 37,
Eventually, the magnetic flux flowing into the upper cores 13a and 13b in two ways is more completely separated, and the effect described in the eighth embodiment can be more remarkably obtained.

FIG. 11 is a plan view showing the shape of the magnetic core in the magnetic head according to the ninth embodiment. A notch 40 is formed at the center of each of the upper cores 13 and 14. With this configuration, the end of the upper core 13 near the magnetic recording medium that is sensitive to the leakage magnetic flux flowing from the magnetic recording medium is continuous in the track width direction.
Since the notch 40 is provided at the center of 14, the leaked magnetic flux that has flowed in flows in the left and right directions in the track width direction, so that the same effect as in the seventh and eighth embodiments can be obtained.

FIG. 12 is a plan view showing the shape of the magnetic core in the magnetic head according to the tenth embodiment. Notches 40 are formed only in the upper core 13 which is sensitive to the leakage magnetic flux flowing from the magnetic recording medium. ing. According to this embodiment, the same effect as that of the ninth embodiment can be obtained.

FIG. 13 is a plan view showing the shape of the magnetic core in the magnetic head according to the eleventh embodiment.
44 and 41 and 42, and
The magnetic permeability of the magnetic material at 43 is different from the magnetic permeability of the magnetic materials at 42 and 44.

When the magnetic permeability of the magnetic core is made different in the left and right directions in the track width direction, a change occurs in the amount of magnetic flux flowing into the left and right sides in the track width direction. In the direction, it is different when you move to the left from the center and when you move to the right,
By detecting the difference signal as described in the first to sixth embodiments, it is possible to detect the direction and magnitude of the track deviation of the magnetic head.

FIG. 14 is a perspective view showing the shape of the magnetic core in the magnetic head according to the twelfth embodiment. The lower core (leading edge side) is bisected in the track width direction as 11a and 11b, and the upper core is divided into two parts. The core (trailing edge side) 13 is configured not to be divided in the track width direction. According to such a magnetic head, when the magnetic core is shared with the recording head, continuous recording can be performed in the track width direction at the time of recording, and leakage magnetic flux flowing from the magnetic recording medium can be left and right in the track width direction at the time of reproduction. Can be separated. In this case, the lower core 11 is bisected in the track width direction.
It is desirable to dispose the magnetic head such that a and 11b are located forward in the running direction of the magnetic recording medium as shown in the figure.

The embodiment of FIGS. 2 to 8 described above is applicable to either the shield type MR head as shown in FIG. 1A or the yoke type MR head as shown in FIG. 1B. Is also applicable. The embodiments shown in FIGS. 9 to 14 are applied to a yoke type MR head as shown in FIG. Next, an embodiment in which the first and second magnetic sensing elements are arranged apart from each other in the track width direction will be described. FIG.
5 to 24 are views showing the embodiment.

FIG. 15 is a perspective view of a magnetic head according to the thirteenth embodiment. The first and second magnetic sensing elements 50a and 50b spaced apart from each other in the track width direction are composed of MR films 15 arranged parallel to the track longitudinal direction.
A pair of current supply electrodes 16 and 17 provided in contact with both ends in the track longitudinal direction of the MR film 15, and a signal detection electrode provided in contact with the MR film 15 between the current supply electrodes 16 and 17. 18.

First and second magnetic sensing elements 50a, 50
0b, the magnetic cores 51 to 53 are arranged so as to form a ring as a whole. A gap 54 is formed in the magnetic cores 51 and 52 that are in contact with the magnetic recording medium. Gaps are also formed between the magnetic cores 51 and 52 and the magnetic core 53, respectively, and the MR films 15 in the magnetic sensing elements 50a and 50b are arranged so as to sandwich these gaps from both sides in the track width direction.

In the magnetic head constructed as described above, when the lower end surfaces of the magnetic cores 51 and 52 are brought into contact with the magnetic recording medium, the leakage magnetic flux due to the signals recorded on the tracks of the magnetic recording medium is reduced. Flows into the MR films 15 of the magnetic sensing elements 50a and 50b through the interface, and the electric resistance of the MR films 15 changes according to the amount of magnetic flux. In this case, the MR film 1 in the magnetic sensing elements 50a and 50b
5, the magnetic flux leaking from the left and right in the track width direction is separated and allowed to flow, and the amounts of these magnetic fluxes can be independently detected. Therefore, it is possible to detect track slippage and azimuth deviation with higher accuracy.

Here, a constant DC current is supplied to the MR film 15 via the current supply electrodes 16 and 17 to detect a voltage or current between the current supply electrodes 16 and 17 and the signal detection electrode 18. Further, when a difference between these voltages or a difference between the currents detected from the magnetic detection elements 50a and 50b is obtained as a detection signal, the MR element 15 in the magnetic detection elements 50a and 50b corresponding to the track shift and the azimuth shift is obtained. The polarity and magnitude of the detection signal change due to the difference in the change in the electrical resistance. Therefore, the track alignment and azimuth adjustment of the recording / reproducing magnetic head can be performed using the detection signal.

FIG. 16 is a perspective view of a magnetic head according to the fourteenth embodiment. The MR film 15 shown in FIG. 15 is divided into two parts 15a and 15b in the track longitudinal direction, and a signal detection electrode 18 is provided. The two ends of the MR film 15a are brought into contact with one branch of the current supply electrode 16 and the signal detection electrode 18, respectively.
5b are connected to the current supply electrode 17 and the signal detection electrode 18 at both ends.
To the other branch. According to this embodiment, the same effect as that of the embodiment of FIG. 15 can be obtained.

FIG. 17 is a perspective view of a magnetic head according to the fifteenth embodiment, in which the electrode 17 in FIG.
The electrodes 16, 18 of both the magnetic sensing elements 50a, 50b are MR
Both ends of the film 15 are in contact with each other. The magnetic core 53 in FIG. 15 is integrated with the magnetic core 52. In this case, the electrodes 16 and 18 also serve as current supply electrodes and signal detection electrodes.

In this embodiment, a constant DC current is applied to the MR film 15 through the electrodes 16 and 18 to cause the electrodes 16 and 18 to rotate.
18 is detected, and the magnetic detecting elements 50a, 50
By obtaining a difference between these voltages detected from the respective signals b as a detection signal, it is possible to detect a track shift and an azimuth shift.

FIG. 18 is a perspective view of a magnetic head according to the sixteenth embodiment. Compared with the embodiment of FIG. 17, the length of the MR film 15 in the track longitudinal direction in the magnetic sensing elements 50a and 50b is shorter. The MR film 15 is arranged so as to sandwich only the gap formed between the magnetic cores 51 and 52 and the vicinity thereof from both sides in the track width direction. According to this embodiment, the same effect as that of the embodiment of FIG. 17 can be obtained.

FIG. 19 is a perspective view of a magnetic head according to the seventeenth embodiment, and shows magnetic cores 51 to 53 in FIG.
Are divided into two in the track width direction, and a non-magnetic film (or a superconducting film) 55 is arranged between them.

According to this embodiment, the magnetic cores 51 to 53
Is magnetically divided into two in the track width direction, so that the leakage magnetic fluxes from the left and right sides in the track width direction are separated and flow into the MR elements 15 in the magnetic detection elements 50a and 50b.
These magnetic flux amounts can be independently detected.
Therefore, it is possible to detect track slippage and azimuth deviation with higher accuracy.

FIG. 20 is a perspective view of a magnetic head according to the eighteenth embodiment. The magnetic cores 51 to 53 in FIG.
To the non-magnetic film (or superconducting film) as in the embodiment of FIG.
Magnetically divided into two via each of 55.

FIG. 21 is a perspective view of a magnetic head according to the nineteenth embodiment. The magnetic cores 51 and 52 shown in FIG.
Is also magnetically divided into two via a non-magnetic film (or superconductive film) 55 in the same manner.

FIG. 22 is a perspective view of a magnetic head according to the twentieth embodiment, and shows magnetic cores 51 to 53 in FIG.
Of these, only the magnetic cores 51 and 52 close to the magnetic recording medium are magnetically divided into two via a non-magnetic film (or superconductive film) 55, respectively.

FIG. 23 is a perspective view of a magnetic head according to the twenty-first embodiment, and shows magnetic cores 51 to 53 in FIG.
Among them, only the magnetic cores 51 and 52 which are close to the magnetic recording medium are magnetically divided into two via a non-magnetic film (or superconductive film) 55 as in FIG.

FIG. 24 is a perspective view of a magnetic head according to the twenty-second embodiment, and shows magnetic cores 51 and 52 in FIG.
Core 5 consisting of only a portion close to the magnetic recording medium
Similarly, 1 is magnetically divided into two via a non-magnetic film (or superconductive film) 55.

According to the embodiments shown in FIGS. 20 to 24, it is needless to say that the same effect as in the embodiment shown in FIG. 19 can be expected in that the magnetic core is magnetically divided in the track width direction.

The magnetic head of the present invention can be used in combination with various magnetic recording media such as a perpendicular recording medium and an oblique recording medium as well as an in-plane recording medium. In addition, the present invention can be variously modified and implemented without departing from the gist.

[0058]

According to the present invention, an MR film is arranged substantially parallel to the track width direction, and at least a pair of current supply electrodes are provided in contact with both ends of the MR film in the track width direction or in the vicinity thereof. At least one signal detection electrode narrower in width than the current supply electrode is provided in contact with the MR film between the current supply electrodes, and a constant current flows through the MR film by the current supply electrode. Signal that has a voltage difference or current difference corresponding to the track shift or azimuth shift can be detected, making it possible to take advantage of the magnetic head using the MR film while maintaining track or azimuth shift even when the track is narrowed. Can be detected with high sensitivity.

In this case, at least a portion of the magnetic core for guiding the leakage magnetic flux from the magnetic recording medium to the magnetic film, which is close to the magnetic recording medium, is magnetically separated into a plurality of pieces in the track width direction, so that higher sensitivity is achieved. Can be detected.

According to the present invention, the first and second magnetic detecting elements are provided apart from each other in the track width direction of the magnetic recording medium, and each of the first and second magnetic detecting elements is mounted on the magnetic recording medium. And an at least one pair of electrodes respectively provided in contact with or near both ends of the MR film in the track longitudinal direction, and a first and a second magnetic field. By enabling the detection element to detect a signal having a voltage difference or a current difference corresponding to track deviation or azimuth deviation,
The size of the entire head in the track width direction can be reduced, and the area for sensing the magnetic flux leakage from the magnetic recording medium in the MR film can be sufficiently ensured. Can be detected.

In this case, the leakage magnetic flux from the magnetic recording medium is applied between the first and second magnetic sensing elements.
A magnetic core for guiding the magnetic film of the magnetic sensing element is arranged, and at least a portion of the magnetic core close to the magnetic recording medium is magnetically divided into a plurality of pieces in the track width direction, so that the track can be detected with higher sensitivity. A shift and an azimuth shift can be detected.

[Brief description of the drawings]

FIG. 1 is a perspective view of a magnetic head according to a first embodiment of the present invention.

FIG. 2 is a plan view of a main part of the embodiment.

FIG. 3 is a plan view of a main part of a magnetic head according to a second embodiment of the present invention.

FIG. 4 is a plan view of a main part of a magnetic head according to a third embodiment of the present invention.

FIG. 5 is a sectional view of a main part of the embodiment.

FIG. 6 is a plan view of a main part of a magnetic head according to a fourth embodiment of the present invention.

FIG. 7 is a plan view of a main part of a magnetic head according to a fifth embodiment of the present invention.

FIG. 8 is a plan view of a main part of a magnetic head according to a sixth embodiment of the present invention.

FIG. 9 is a plan view of a main part of a magnetic head according to a seventh embodiment of the present invention.

FIG. 10 is a plan view of a main part of a magnetic head according to an eighth embodiment of the present invention.

FIG. 11 is a plan view of a main part of a magnetic head according to a ninth embodiment of the present invention.

FIG. 12 is a plan view of a main part of a magnetic head according to a tenth embodiment of the present invention.

FIG. 13 is a plan view of a main part of a magnetic head according to an eleventh embodiment of the present invention.

FIG. 14 is a perspective view of a main part of a magnetic head according to a twelfth embodiment of the present invention.

FIG. 15 is a perspective view of a main part of a magnetic head according to a thirteenth embodiment of the present invention.

FIG. 16 is a perspective view of a main part of a magnetic head according to a fourteenth embodiment of the present invention.

FIG. 17 is a perspective view of a main part of a magnetic head according to a fifteenth embodiment of the present invention.

FIG. 18 is a perspective view of a main part of a magnetic head according to a sixteenth embodiment of the present invention.

FIG. 19 is a perspective view of a main part of a magnetic head according to a seventeenth embodiment of the present invention.

FIG. 20 is a perspective view of a main part of a magnetic head according to an eighteenth embodiment of the present invention.

FIG. 21 is a perspective view of a main part of a magnetic head according to a nineteenth embodiment of the present invention.

FIG. 22 is a perspective view of a main part of a magnetic head according to a twentieth embodiment of the present invention.

FIG. 23 is a perspective view of a main part of a magnetic head according to a twenty-first embodiment of the present invention.

FIG. 24 is a perspective view of a main part of a magnetic head according to a twenty-second embodiment of the present invention.

FIG. 25 is a perspective view showing a conventional example using an induction type head.

FIG. 26 is a perspective view showing an example of a conventional yoke type MR head.

FIG. 27 is a perspective view showing an example of a conventional shield type MR head.

FIG. 28 is a diagram showing a relationship between a head track deviation and an envelope difference in the present invention.

[Explanation of symbols]

11 Lower core 12 Gap 13, 13a, 13b, 14 Upper core 15, 15
a, 15b MR film 16, 17 Current supply electrode 18 Signal detection electrode 19 Insulating film 21-26
Signal detection electrodes 31-35 ... Signal detection electrodes 37 ... Superconducting film 40 ... Notches 41-44 ...
Magnetic cores 50a, 50b ... magnetic detecting elements 51 to 53 ...
Magnetic core 54: gap 55: non-magnetic film or superconducting film

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Tetsuo Inoue 1 Toshiba Research Institute, Komukai, Kawasaki-shi, Kanagawa Prefecture (56) References JP-A-3-134810 (JP, A) JP-A-3-134810 Hei 4-121809 (JP, A) Japanese Utility Model Showa 52-155519 (JP, U) Special Table 62-502923 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 5 / 39

Claims (1)

(57) [Claims] 1. A magnetic film (MR ) having a magnetoresistive effect and arranged substantially parallel to a track width direction of a magnetic recording medium.
A film), the magnetic recording medium of the at least a pair of current supply electrodes provided in contact with both ends or in the vicinity thereof in the track width direction, said magnetic film between said current supply electrodes of said magnetic film
; And a signal detecting electrode provided in contact with the tip portion to the portion near the body, distribution of the insulating film between said signal detecting electrode and the magnetic film
A magnetic head characterized by being placed .