JPS6085408A - Vertical magnetic head - Google Patents

Abstract

PURPOSE:To record signals with a high density efficiently and reproduce signals with a high sensitivity by constituting a vertical magnetic head so that signals are written with auxiliary and main magnetic poles consisting of exciting coils and high-permeability magnetic bodies and recorded signals are read out with a magnetoresistance effect element. CONSTITUTION:A magnetoresistance effect element 50 including an electrode 50P is stuck directly to an auxiliary magnetic pole 30, and they are joined into one body to constitute an auxiliary magnetic pole block. A lead wire 40L is connected electrically to a recording signal output device, and an electrode 50P is connected electrically to a constant current source and a signal reproducing device, and signals are recorded on a vertical magnetic recording medium by electromagnetic conversion of recording signals due to an exciting coil 40, and signals are reproduced from the recording medium by the magnetoresistance effect due to the magnetoresistance effect element 50. By this constitution, recorded signals are reproduced effectively and efficiently even if they are recorded with an ultrahigh density, and the constitution of a vertical magnetic recording device is simplified because the lead wire 40L and the electrode 50P are led out from the same direction.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a perpendicular magnetic head used in a perpendicular magnetic recording system, and in particular to a head structure designed to ensure sufficient reproduction sensitivity even in high-density recording and reproduction. Regarding improvements.

(Prior Art) Perpendicular magnetic recording has been actively researched and developed in recent years as a magnetic recording method that enables high-density recording incomparably with conventional magnetic recording methods.

By the way, this perpendicular magnetic recording method is a method that attempts to perform magnetic recording in the "thickness direction" of a recording medium such as a tape or disk, so it goes without saying that this recording medium as well as the recording/reproducing head, that is, the perpendicular Naturally, a magnetic head is required that has characteristics different from those of conventional magnetic heads. That is, in a perpendicular magnetic head, a) since the recording medium has perpendicular anisotropy magnetically, it is possible to generate a magnetic field with a sharp distribution and a large overlap direction to sufficiently magnetize the magnetic field. and b) It is possible to record on a recording medium with a small magnetomotive force and to extract a large playback output from the recorded recording medium.

is mainly required. It is well known that an auxiliary pole excitation type magnetic head has been proposed to meet these requirements. The structure of this auxiliary pole excitation type magnetic head is shown in FIG.

In other words, this type of magnetic head, as shown in FIG.
A main magnetic pole 1 made of a high magnetic permeability magnetic thin film such as a nickel (Ni)-iron (Fe) alloy thin film and arranged so that its tip is in sliding contact with the magnetic layer of the recording medium RM, and a non-magnetic magnetic pole that holds this main magnetic pole 1. The body holders 2a and 2b are made of a high magnetic permeability magnetic material such as ferrite and have a sufficient thickness compared to the main magnetic pole 1, and are arranged to face the tip of the main magnetic pole 1 via the recording medium RM. The structure includes an auxiliary magnetic pole 3 and an excitation coil 4 as a signal recording/reproducing coil wound around the tip of the auxiliary magnetic pole 3. By passing an appropriate current through the excitation coil 4, the auxiliary magnetic pole 3 A signal is recorded in the magnetic layer of the recording medium RM by a strong perpendicular magnetic field of the main magnetic pole 1 generated by excitation of the main magnetic pole 1, and the magnetic flux of the main magnetic pole 1 generated by the magnetic field from the magnetic layer of the recording medium RM is induced to the auxiliary magnetic pole 3. It operates to regenerate the signal.

However, such an auxiliary pole excitation type perpendicular magnetic head ζ
Since this is essentially a magnetic flux open type, when the above-mentioned signal is recorded at a particularly high density, the magnetic field loop becomes large during reproduction, causing a large energy loss, and the recording The reproduction output may decrease due to changes in the magnetic field on the medium RM being indirectly induced to the auxiliary magnetic pole 3 via the main magnetic pole 1 and used as a reproduction signal, or the thickness of the main magnetic pole 1 may be lower than the recording wavelength. So-called dip development, in which the reproduction output suddenly drops when an even number of times L is matched, occurs, and many problems still remain in the reproduction system.

[Purpose of the invention]

This invention was made in view of the above-mentioned circumstances, and is a vertical magnetic head that is simple in structure and highly practical, which can ensure sufficient reproducibility even in high-density perpendicular magnetic recording and reproduction. The purpose is to provide a magnetic head.

[Structure of the invention]

That is, in this invention, a magnetoresistive element head (M
R head) as a perpendicular magnetic reproducing head, it is possible to obtain a large reproducing output with a high S/N ratio even in the case of high-density recording, and it is possible to obtain a large reproducing output with a high S/N ratio. Focusing on avoiding various inconveniences that occur in the reproduction system, when recording signals on a recording medium, the excitation coil and an auxiliary magnetic pole and a main magnetic pole made of a high permeability magnetic material are used to write signals. In addition, when reproducing signals from a recording medium, the above-mentioned magnetoresistive element is used to read the recorded signal, and furthermore, the structure is simplified, the reproduction output is increased, and the high reproduction output is maintained during high-density recording. In consideration of the above, the magnetoresistive element is arranged on the side of the auxiliary magnetic pole, and preferably formed integrally with the auxiliary magnetic pole (4).

〔Effect of the invention〕

Therefore, according to the perpendicular magnetic head according to the present invention,
Not only the structure of the head itself, but also the device equipped with the head has a simple configuration that requires only the addition of a means for applying a constant current to the magnetoresistive element, allowing for highly efficient and high-density recording of the recording medium. Signal recording and highly sensitive signal reproduction from recording media can be performed.

〔Example〕

First, the signal reproduction principle of the magnetoresistive element used in the perpendicular magnetic head of the present invention will be briefly explained with reference to FIG.

In FIG. 2, 5 is the magnetoresistive element, 6 is a constant current source that supplies a constant current through the electrodes at both ends of the magnetoresistive element 50, and the magnetoresistive element 5 in such a state is When some kind of magnetic field acts on it, its electrical resistance changes due to heat. That is, as shown in FIG. 2, when the magnetoresistive effect cable 5 to which the constant electric current KI is applied, a magnetic flux corresponding to the recorded content of the medium is induced from the main magnetic pole (not shown) during reproduction, and a magnetic field H is generated. By disposing it near the auxiliary magnetic pole 3 where the auxiliary magnetic pole 3 is generated, the magnetic field H of the auxiliary magnetic pole 3 acts to generate magnetization M in the magnetoresistive element 5, and the electric resistance value changes accordingly. do. therefore,
By monitoring the change in the voltage V between the electrodes at both ends of the magnetoresistive element 5, changes in the magnetic field on the recording medium 1M can be detected, and the electromagnetic conversion recording signal to the recording medium RM described above can be detected as described above. It is effectively regenerated by the voltage ■.

Next, the reason why signal reproduction using the above magnetoresistive element is advantageous in a perpendicular magnetic head will be explained with reference to FIG.

FIG. 3 shows an example of the input/output characteristics of the auxiliary pole excitation type perpendicular magnetic head as shown in FIG. 1 above.
In particular, here, the main magnetic pole thickness is 0.8μ as the characteristic curve A1.
m and the data recording density on the perpendicular magnetic recording medium is 5Kbpi
(bit/1nch) (The input/output characteristics of the same perpendicular magnetic head at time D are the characteristic side !l!A2, where the main magnetic pole thickness is the same <0.8 μm and the above data recording density is 3QKbpi.
Characteristic curve B1 shows the input/output characteristics of the same perpendicular magnetic head when the main magnetic pole thickness is 0.3 μm and data recording density is 5 Kbpi, and characteristic curve B2 shows the input/output characteristics of the same perpendicular magnetic head when the main magnetic pole thickness is 0.3 μm and the data recording density is 5 Kbpi. The input/output characteristics of the perpendicular magnetic head when the thickness is 0.3 μm and the data recording density is 30 Kbpi are shown as characteristic curve B3, and the main pole thickness is 0.3 μm.
It shows the input/output characteristics of the same perpendicular magnetic head when the data recording density is 5QKbpi in μm.

Summarizing the characteristics shown in FIG. 3, it can be said that even if the main magnetic pole thickness becomes thinner and the data recording density increases to 60 Kbpi, the magnetomotive force at which the reproduction output is saturated remains almost constant. That is, even when the main pole is thin and ultra-high density recording is being performed, the perpendicular magnetic recording medium is almost saturated with recording. Therefore, the main reason why the reproduction output decreases when such ultra-high density recording is performed is the loss in the reproduction system of the perpendicular magnetic head itself. One of the causes of this loss in the reproduction system is the low signal reproduction efficiency of the excitation coil that is wound around the auxiliary magnetic pole and performs the electromagnetic conversion described above. In this regard, the magnetoresistive element, which reproduces signals using the magnetoresistive effect described above, has almost no signal reproduction loss as in the electromagnetic conversion method described above, so it is difficult to reproduce signals even when ultra-high-density recording is performed. Recorded signals can be effectively and highly efficiently reproduced without reducing the output level.

FIG. 4 shows an embodiment of a superimposed magnetic head according to the present invention, which is equipped with such a magnetoresistive element. however,
In FIG. 4, only the auxiliary magnetic pole portion of this embodiment head is shown for convenience, and it is arranged so as to sandwich the perpendicular magnetic recording medium and face the auxiliary magnetic pole (in FIG. 4, it is arranged above the auxiliary magnetic pole). ) The illustration of the main magnetic pole portion is omitted.

Now, in FIG. 4, 30 is an auxiliary magnetic pole, 40 is an excitation coil wound around this auxiliary magnetic pole 30J, 40L is a lead wire of the excitation coil 40, 50 is a magnetoresistive element, 50P
is a constant current applying electrode of the magnetoresistive element 50, and in the same embodiment, the magnetoresistive element 50 including the electrode 50P is directly fixed to the auxiliary magnetic pole 30.
Together with this, it forms an auxiliary magnetic pole block. In this embodiment head, the lead wire 40L is electrically connected to a recording signal output device (not shown), and the electrode 50P is electrically connected to a constant current source and a signal reproducing device (not shown) to perform perpendicular magnetic recording. When recording a signal on a medium, magnetic recording is performed on the recording medium by electromagnetic conversion of the recording signal by the excitation coil 40, and when reproducing a signal from the recording medium, the aforementioned magnetoresistive element 50 performs magnetic recording. The same signal is reproduced by the magnetoresistance effect.

By configuring the perpendicular magnetic head in this manner, even when ultra-high-density recording is performed as described above, the recorded signal can be effectively and highly efficiently reproduced, and the read! Since I4<)L and the electrode 50P can be drawn out from the same direction, the configuration of the perpendicular magnetic recording device is also simplified.

In the above embodiment, since it is assumed that Ni-Zn ferrite or the like having a large resistivity l is used as the auxiliary magnetic pole 3°, the magnetoresistive element 50 and this constant current applying electrode 50P are connected to the auxiliary magnetic pole 30. However, this auxiliary magnetic pole 30 is made of Mn, which has a small resistivity ρ.
- When using Zn ferrite etc. l moss, #! As shown in FIG. 5, it is desirable to fix the magnetoresistive element 50 and the constant current applying electrode 50P to the auxiliary magnetic pole 30 via a suitable insulating thin film 70.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the basic configuration of an auxiliary pole excitation type perpendicular magnetic head, FIG.
4 is a perspective view showing an embodiment of the perpendicular magnetic head according to the present invention, and FIG. FIG. 7 is a perspective view showing another embodiment of the magnetic head. 1... Main magnetic pole, 2... Non-magnetic material holder, 3, 30...
Auxiliary magnetic pole, 4, 40... Excitation coil, 40L... Excitation coil lead wire, 5, 50... Magnetoresistive element,
50P... Constant current applying electrode, 6... Constant current source, 7o
...Insulator thin film. Figure 4 Figure 5 0L

Claims (1)

[Claims] (IJ) A main magnetic pole arranged perpendicularly to a perpendicular magnetic recording medium, and an excitation coil arranged to face the main magnetic pole with the perpendicular magnetic recording medium interposed therebetween. The main magnetic pole, which is generated by exciting the auxiliary magnetic pole, includes an auxiliary magnetic pole, a magnetoresistive element disposed close to the auxiliary magnetic pole, and an electrode for applying a constant current to the magnetoresistive element. a perpendicular magnetic head that records signals on the perpendicular magnetic recording medium based on a perpendicular magnetic field of the perpendicular magnetic recording medium and reproduces signals from the perpendicular magnetic recording medium based on voltage changes occurring between constant current applying electrodes of the magnetoresistive element; (2) The magnetoresistive element and the constant current applying electrode are integrally formed with the auxiliary magnetic pole.
1) The overlapping magnetic head described in item 1).