JPH03684B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic head, and relates to a recording/reproducing device that performs perpendicular magnetic recording on a magnetic recording medium having an axis of easy magnetization perpendicular to the surface of the magnetic recording medium. This relates to the magnetic head used.

[Prior Art] Unlike the conventional horizontal magnetic recording method in which magnetization is performed in a direction horizontal to the surface of a magnetic recording medium for recording, a vertical magnetic recording method in which magnetization is performed in a direction perpendicular to the surface of a magnetic recording medium is used. A magnetic recording method has been proposed.
Since this perpendicular magnetic recording system can perform magnetic recording at extremely high density, it has attracted attention as a future magnetic recording system and various structures have been proposed.

One of these methods involves aligning the magnetization of the perpendicular recording layer of a magnetic recording medium in a certain direction in advance and guiding it to a perpendicular magnetic recording head, which enables magnetic recording with a small amount of current while applying a bias magnetic field. There is something to try.

A conventional structure using this method is shown in Figure 1A.
Shown below.

That is, in FIG. 1A, the reference numeral 101 is the main magnetic pole, which is made of a high magnetic permeability material such as permalloy and is used as a thin film of about 1 μm.

What is indicated by the code 102 is the first auxiliary magnetic pole, 103
indicates a second auxiliary magnetic pole, both of which are made of a high permeability magnetic material such as MnZn ferrite.

Each of these magnetic poles 101, 102, 103 is approximately E
The other end sides of the protruding portions of the letter-shaped portions, which are arranged to sandwich the base end of the main magnetic pole 101, are arranged facing each other at a predetermined distance from the main magnetic pole 101. These two auxiliary magnetic poles can form a magnetic closed loop more efficiently than magnetic poles on only one side, and can achieve improved recording and reproducing efficiency.

The ends of the first and second auxiliary magnetic poles 102, 103 on the main magnetic pole 101 side have windings 104a, 1, respectively.
04b has been applied. These windings serve to provide a magnetomotive force to cause the magnetic recording medium to undergo magnetization reversal.

A demagnetizing pole 105 is disposed at a predetermined distance from the first auxiliary magnetic pole 102 in the direction of entry of the magnetic recording medium to align the magnetization direction of the perpendicular recording layer of the magnetic recording medium in a predetermined direction. In the illustrated example, a permanent magnet is used as the demagnetizing pole 105, and the end in the y direction shown in FIG. 1 is the north pole.

Reference numeral 109 is a magnetic recording medium, in which a high permeability magnetic layer 107 made of a thin film such as permalloy with a thickness of 0.5 to 1 μm is formed on the surface of a base 108 made of polyester, polyimide, etc. on the main pole 101 side. A perpendicular recording layer 106 having an axis of easy magnetization in the y direction is formed on the surface. Although the figure shows an embodiment in which a tape-like structure is adopted as the magnetic recording medium, in the case of a disk, the base 108 is made of aluminum alloy or the like.

The perpendicular recording layer 106 and the high permeability magnetic layer 107 perform magnetic recording in the perpendicular direction, which is a necessary condition for achieving high density recording.

The recording process in the structure shown in FIG. 1A will be explained using the hysteresis loop shown in FIG. 1B.

In FIG. 1B, the horizontal axis represents the magnitude of the magnetic field, and the vertical axis represents the magnitude of magnetization.

Assuming that the magnetic recording medium 109 is running in the x direction in FIG. 1A, the perpendicular recording layer 106
The demagnetization pole 105 aligns the magnetization in a certain direction at the opposite point C, and the demagnetization state 11
It is 0.

Next, the main magnetic pole 101 is attached to the windings 104a and 104b.
On the hysteresis loop at point B opposite to
Apply bias current so that it reaches point 111.

In addition to this bias current, windings 104a, 10
4b, the signal current is passed through the point 111, passes through the point 112, and reaches the point 113 where a reversal magnetic field is generated. As a result, B facing the main magnetic pole 101
The magnetization is opposite at the point, and the second auxiliary magnetic pole 1
After passing point D′ opposite to 03, the recording state
It has reached 114 points. In this process, at point D′,
Although there is a magnetic field in the opposite direction to the signal magnetic field at point B, it does not reach a strength that causes magnetization reversal.

If no signal current is applied to the windings 104a and 104b, the magnetization at point 110, which is in a demagnetized state, is maintained even when the point D' is reached.

Note that the directions of the currents flowing through the windings 104a and 104b are reversed so that the generated magnetic flux passes through the main magnetic pole 101.

Further, the magnetic flux generated by the windings 104a and 104b passes through the tips of the first and second auxiliary magnetic poles 102 and 103, passes through points D and D' perpendicularly, and is concentrated at point B, which faces the main magnetic pole. , a closed loop passing through point A, which is the tip of the main magnetic pole 101, is drawn.

The auxiliary magnetic poles are the first and second auxiliary magnetic poles 102 and 1
The reason why the magnetic field lines are separated into 03 is to efficiently form a closed loop of magnetic lines of force as described above, thereby improving recording efficiency and reproduction efficiency.

Also, regarding the magnetic field, the signal current is 111 in Figure 1B.
Since the magnetic field from zero to 111 points is provided by a DC bias current, the recording efficiency is further improved.

This method of recording after aligning the magnetization direction in a certain direction is extremely effective in terms of reducing the recording current.

[Problems to be Solved by the Invention] However, adopting the above structure had the following drawbacks.

1. A demagnetizing pole is required in addition to the main magnetic pole and the auxiliary magnetic pole, resulting in an increase in the number of parts.

2. The volume of the device increases as the number of demagnetizing poles increases.

3. Concentration of magnetic lines of force may occur at the corner portions of the sliding surface of the magnetic recording medium of the second auxiliary magnetic pole 103, that is, the portions indicated by symbols F1 and F2 in FIG. 1A, and written information may be erased. It is unstable.

[Means for Solving the Problems] The present invention was developed to eliminate the above-mentioned drawbacks, and it integrates the demagnetizing pole to reduce the number of parts and downsize, and significantly improves writing efficiency. It is an object of the present invention to provide a magnetic head configured to allow

In order to achieve the above object, in the present invention, a plurality of protruding magnetic poles forming a substantially E-shape are opposed to each other on one surface of a magnetic recording medium. Each is set as a first auxiliary magnetic pole, a main magnetic pole, and a second auxiliary magnetic pole,
In the magnetic head that performs perpendicular magnetic recording and reproducing by sliding on the magnetic recording medium, at least one tapered protrusion having a predetermined peak angle is formed on the first auxiliary magnetic pole, and a ridge line portion of the protrusion is formed. A structure is adopted in which the first auxiliary magnetic pole is used as a sliding portion and is used as a demagnetizing pole, and the main magnetic pole and the second auxiliary magnetic pole are used as magnetic poles for recording and reproducing.

In addition, the first auxiliary magnetic pole is used as a demagnetizing pole, and a tapered protrusion is formed along the ridge line in the portion facing the magnetic recording medium to prevent lines of magnetic force from concentrating on the corners at both ends of the second auxiliary magnetic pole. It adopts a structure that forms a curved surface.

[Function] Since the demagnetizing pole is integrally formed in the first auxiliary magnetic pole, the structure is simplified, and since the concentration of magnetic lines of force is avoided at both ends of the second auxiliary magnetic pole, erasure of written information is prevented.

[Example] The details of the present invention will be described below based on the example shown in the drawings.

FIG. 2 and subsequent figures are for explaining one embodiment of the invention. In the figures, the same or corresponding parts as in FIGS. 1A and 1B are given the same reference numerals, and the explanation thereof will be omitted.

In the embodiment shown in FIG. 2, the first auxiliary magnetic pole 1
The magnetic recording medium sliding surface of No. 02 is formed not parallel to the medium but at an angle, and each angle θ of the projection E4 is smaller than 90 degrees.

On the other hand, the corner portion F of the second auxiliary magnetic pole 103
3, F4 has a curved surface shape to prevent concentration of magnetic lines of force. The shape of this curved surface may be a curve that follows any function such as a quadratic function, an exponential function, or a logarithmic function, as long as it is a curved surface that asymptotically separates from the medium.

Next, the recording operation of this embodiment will be explained.

Direct current is previously applied to the windings 104a and 104b in order to generate a bias magnetic field.
The magnetic lines of force generated within the winding are the first auxiliary magnetic pole 102,
The high permeability magnetic layer 1 passes through the second auxiliary magnetic pole 103.
07, a point H facing the main magnetic pole 101, and a point A at the tip of the demagnetizing pole, forming a closed loop.

At this time, the magnetic field becomes strongest at point G near the protrusion E4 of the tapered first auxiliary magnetic pole where magnetic flux is most likely to concentrate, and magnetization reversal of the perpendicular recording layer 106 becomes possible. In other words, even if the demagnetizing pole 105 [FIG. 1A] for magnetizing in a certain direction is omitted, the bias magnetic field 111 [FIG. 1B] is applied near the main magnetic pole, improving recording efficiency.

Further, since the main magnetic pole 101 is extremely thin, its magnetic resistance is high, and the magnetic field strength slightly decreases near the H point, and is only strong enough to serve as a bias magnetic field for magnetization reversal of the perpendicular recording layer 106. Furthermore, since there is no magnetic flux concentration at point I facing the second auxiliary magnetic pole 103,
The magnetic field strength is extremely low and will not erase the recorded magnetization.

It should be noted that each angle θ of the tapered protrusion E4 is suitably 80 degrees or less in order to prevent the tip from being magnetically saturated and to sufficiently concentrate the lines of magnetic force.

3A to 3D illustrate different embodiments of the first auxiliary magnetic pole 102, in which A is provided with a protrusion E9 approximately at the center of the medium sliding surface, and B is an example in which a protrusion E9 is provided approximately at the center of the medium sliding surface. A protrusion E5 is provided from the center of the tip of the first auxiliary magnetic pole 102 toward the tip. C
There are protrusions E on both left and right ends of the medium sliding surface of the auxiliary magnetic pole.
6 and E7, and there is a recess between them. D indicates that a projection E8 is provided at the tip of the auxiliary magnetic pole on the leading edge side.

Figures 3A to 3D only show a few examples of the shapes of the first auxiliary magnetic pole, and it is completely free to combine these shapes with curves, and which shape to adopt depends on the processing. It is determined based on the method, degree of magnetic saturation, recording/reproducing efficiency, etc.

Figures 4A and 4B show other examples of winding methods for more reliably performing the function of the demagnetizing pole, and the stronger the magnetic flux coming out of the first auxiliary magnetic pole 102, the more stable it becomes. Since the magnetization of the perpendicular recording layer can be aligned in a certain direction, the auxiliary magnetic pole 102
It is more efficient to move it as close to the tip as possible.

Therefore, as shown in FIG. 4A, the winding 401 is moved from the connecting portion 402a between the main magnetic pole 101 and the first auxiliary magnetic pole 102 to the tip of the first auxiliary magnetic pole 102.

FIG. 4B shows a diagram in which the excitation winding 401 for the demagnetizing pole and the windings 104a and 104b for the signal magnetic field are separated.This configuration is necessary to stabilize both magnetization reversal and the bias magnetic field near the main pole. is suitable.

In the previous explanation, we have explained how one of the two auxiliary magnetic poles is used as a demagnetizing pole to facilitate the formation of a magnetic closed loop, and the parts are omitted. In this case, the symbol E4 in FIG. 2, the symbol E5, E6, E in FIG.
7, E8, and E9 generate electromotive force in the windings 104a and 104b, which may cause a decrease in SN.
In response to this, the following measures are taken.

FIG. 5 shows an embodiment in which the shape of the first auxiliary magnetic pole 102 is modified in the width direction of the track. The embodiment shown in FIG. 5 is a view of the embodiment shown in FIG. 4A from the medium sliding surface side, and the symbol E10
The ridge line E10 is non-parallel to the track width direction of the main magnetic pole 101 and has an azimuth angle α. In other words, if the azimuth angle α is set between the straight line passing through the track width direction of the main magnetic pole and the ridge line E10, the signal will not be reproduced at the ridge line E10 due to azimuth loss, thereby preventing a decrease in SN. I can do it. It is sufficient that the azimuth angle is greater than 7 degrees.

Although all of the above-mentioned embodiments have been shown only for recording using a DC bias magnetic field, the same effects as those of the above-mentioned embodiments can be expected in the case of recording using an AC bias magnetic field. Even if the second auxiliary magnetic pole is omitted, almost the same effect can be expected.

[Effects of the Invention] As is clear from the above description, according to the present invention, a plurality of protruding magnetic poles forming a substantially E-shape are opposed to each other on one surface of a magnetic recording medium, and the entrance side of the magnetic recording medium is and set them as a first auxiliary magnetic pole, a main magnetic pole, and a second auxiliary magnetic pole toward the exit side, respectively.
In the magnetic head that performs perpendicular magnetic recording and reproducing by sliding on the magnetic recording medium, at least one tapered protrusion having a predetermined peak angle is formed on the first auxiliary magnetic pole, and a ridge line portion of the protrusion is formed. Since the sliding part of the first auxiliary magnetic pole is used as a demagnetizing pole, and the main magnetic pole and the second auxiliary magnetic pole are used as recording and reproducing magnetic poles, the first auxiliary magnetic pole is used as a demagnetizing pole. It is possible to omit the demagnetizing pole which was required separately as in the conventional case, and the number of parts can be reduced and the size of the magnetic head can be reduced. Furthermore, the second
If the corner of the auxiliary magnetic pole is made into a curved surface to avoid concentration of magnetic lines of force, erroneous erasure can be significantly reduced. Further, if the ridge line of the protruding portion of the first auxiliary magnetic pole is set at an azimuth angle with respect to the main magnetic pole, signal reproduction from the auxiliary magnetic pole can be prevented and a good S/N ratio can be maintained.

[Brief explanation of the drawing]

FIGS. 1A and 1B are a schematic diagram of a conventional magnetic head and a diagram of a hysteresis loop explaining the recording state, FIG. 2 is a schematic diagram of an embodiment of the present invention, and FIGS. 3A to D 4A and 4B are schematic configuration diagrams showing different embodiments of the present invention, and FIG. 5 is a front view illustrating the azimuth angle of the ridge line. 101...Main magnetic pole, 102...First auxiliary magnetic pole,
103...Second auxiliary magnetic pole, 104a, 104b,
401... Winding wire, 109... Magnetic recording medium.

Claims (1)

[Scope of Claims] 1. A plurality of protruding magnetic poles forming a substantially E-shape are opposed to each other on one surface of a magnetic recording medium, and each is arranged as a first auxiliary magnetic pole from the entrance side to the exit side of the magnetic recording medium. , a main magnetic pole, a second auxiliary magnetic pole,
In the magnetic head that performs perpendicular magnetic recording and reproducing by sliding on the magnetic recording medium, at least one tapered protrusion having a predetermined peak angle is formed on the first auxiliary magnetic pole, and a ridge line portion of the protrusion is formed. A magnetic head characterized in that the sliding portion of the first auxiliary magnetic pole is used as a demagnetizing pole, and the main magnetic pole and the second auxiliary magnetic pole are used as recording/reproducing magnetic poles. 2. The magnetic head according to claim 1, wherein the peak angle of the protrusion formed on the magnetic recording medium sliding surface side of the first auxiliary magnetic pole is 80 degrees or less. 3. The magnetic head according to claim 1, wherein the number of protrusions formed on the magnetic recording medium sliding surface side of the first auxiliary magnetic pole is two. 4. The magnetic head according to any one of claims 1 to 3, wherein the ridge lines of the protrusion are non-parallel to a straight line passing through the track width direction of the main pole. 5. Any one of claims 1 to 4, characterized in that the corner portions at both ends of the second auxiliary magnetic pole on the magnetic recording medium sliding surface side are curved to avoid concentration of magnetic lines of force. magnetic head. 6. A winding according to any one of claims 1 to 5, characterized in that the winding through which the demagnetizing pole current is applied is provided near the medium sliding surface of the first auxiliary magnetic pole. magnetic head. 7. Claim 1, characterized in that the signal magnetic field windings are provided at two locations: between the first auxiliary magnetic pole and the main magnetic pole and between the main magnetic pole and the second auxiliary magnetic pole. 5. The magnetic head according to any one of items 1 to 5.