JPH0439729B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a perpendicular magnetic head with improved recording and reproducing efficiency.

[Conventional technology]

Conventionally, this type of vertical perpendicular magnetic head
The one shown in Figure 5 was found. In the figure, 1a is an auxiliary yoke made of magnetic ferrite, etc., 2 is a main pole made of a ferromagnetic thin film made of permalloy, Co-Zr-Nb, etc. by vapor deposition or sputtering, and 3 is a coil conductor of a winding. , 4 is a non-conductive non-magnetic material such as glass, 5 is a magnetic recording medium such as a magnetic tape or a magnetic disk, and a is a pseudo gap, which is the distance between the main magnetic pole 2 and the auxiliary yoke 1a.

The conventional vertical magnetic head is constructed as described above, and magnetic flux is generated by passing current through the coil conductor 3 wound around the main pole 2. The generated magnetic flux flows inside the main magnetic pole 2 having high magnetic permeability, magnetizes the magnetic recording medium 5, and is induced into the auxiliary yoke 1a.

[Problem that the invention seeks to solve]

In the conventional perpendicular magnetic head as described above, since the pseudo gap a is several mm, the magnetic flux induced from the main pole 2 to the auxiliary yoke 1a via the magnetic recording medium 5 is weakened, resulting in a decrease in recording efficiency and reproduction efficiency. There was a problem.

The present invention was made to solve these problems, and an object of the present invention is to obtain a perpendicular magnetic head with high recording efficiency and high reproduction efficiency.

[Means for solving problems]

The perpendicular magnetic head of the present invention includes a magnetic main pole yoke, a magnetic main pole provided on the main pole yoke and whose end face faces the magnetic recording medium, and a winding window.
a magnetic auxiliary yoke that serves as a magnetic path for magnetic flux passing through the main magnetic pole and whose end face faces the magnetic recording medium;
and a winding provided through the winding window, the distance between the auxiliary yoke and the main pole at the portion facing the magnetic recording medium is 70 to 250 μm.
and the space between the end surface of the auxiliary yoke facing the magnetic recording medium and the magnetic recording medium is 50 mm.
~100μm range.

[Effect]

In this invention, by narrowing the gap between the auxiliary yoke and the main magnetic pole to 250 μm or less in the portion facing the magnetic recording medium, the magnetic flux induced in the auxiliary yoke is stronger than that in the main magnetic pole. Note that if the diameter is 70 μm or less, a large amount of magnetic flux leaks directly to the auxiliary yoke without passing through the magnetic recording medium, so by setting the magnetic flux in the range of 70 to 250 μm, the recording efficiency and reproduction efficiency of the perpendicular magnetic head can be improved. Furthermore, if the gap between the end face of the auxiliary yoke facing the magnetic recording medium and the magnetic recording medium is set to 50 μm or more, the magnetic flux density within the magnetic recording medium against noise caused by ghosts will decrease rapidly. In addition,
Since the signal reproduction efficiency decreases when the diameter exceeds 100 μm, the range is set to 50 to 100 μm, which can reduce ghosts in the reproduced waveform.

〔Example〕

FIG. 1 is a front view showing a perpendicular magnetic head according to the present invention, and numerals 2 to 5 are similar to conventional heads. 1a is an auxiliary yoke made of magnetic ferrite or the like as in the conventional case, and 1b is a main pole yoke made of magnetic ferrite or the like.
The end face of the main pole 2 faces the magnetic recording medium 5. The auxiliary yoke 1a is provided with a winding window 6, serves as a magnetic path for the magnetic flux passing through the main pole 2, and has an end face facing the magnetic recording medium. a is the magnetic recording medium 5
The gap (pseudo-gap) between the auxiliary yoke 1a and the main pole 2 at the opposing portion thereof is in the range of 70 to 250 μm, in this case 150 μm, and a non-conductive non-magnetic material such as glass is molded in between.

It should be noted that the gap b, which will be described later, is for when the vehicle is in operation and is considered to include the flying distance.

FIG. 2 shows the relationship between the magnetic field strength and the pseudo gap in the magnetic recording medium 5 directly below the main magnetic pole 2 in the perpendicular magnetic head constructed as described above.
FIG. 4 is a characteristic diagram showing the gap b (see FIG. 3) between the end face of the magnetic recording medium 5 facing the magnetic recording medium 5 and the magnetic recording medium as parameters. The vertical axis represents the magnetic flux density T, and the horizontal axis represents the pseudo gap a. Pseudo gap a
If it is less than 70 μm, the main magnetic pole 2 and the auxiliary yoke 1a
The magnetic flux that leaks without passing through the magnetic recording medium between the main magnetic poles increases, and the perpendicular magnetic field strength immediately below the main magnetic pole decreases. Further, when the pseudo gap a becomes 250 μm or more, the magnetic flux induced even to the auxiliary yoke 1a decreases. As can be seen from Figure 2, when the size of the pseudo gap a is 70 μm or more and 250 μm or less, the magnetic field strength directly under the main pole increases, and even more so when the size of the pseudo gap a is 70 μm or more and 250 μm or less.
It is largest when it is 200 μm or less, and high recording efficiency and playback efficiency can be expected.

From this result, a perpendicular magnetic head with good performance can be obtained by setting the pseudo gap a to 70 to 250 .mu.m, and an even better performance can be obtained by setting the pseudo gap a to 100 to 200 .mu.m.

In addition, in the perpendicular magnetic head shown in Fig. 1, the ghost of the reproduced waveform occurs when recording and reproducing a long wavelength.
This becomes a big problem and appears as noise.

FIG. 3 is a front view showing a perpendicular magnetic head according to an embodiment of the present invention, in which there is a gap between the end surface of the auxiliary yoke 1a facing the magnetic recording medium and the sliding surface of the magnetic recording medium 5.
A gap b of 50 μm or more and 100 μm or less is provided, and a parallel portion is provided on the end surface of the auxiliary yoke 1a facing the magnetic recording medium. In the figure, b is the distance between the auxiliary yoke 1a and the sliding surface of the magnetic recording medium 5, and C is the length of the portion of the auxiliary yoke 1a parallel to the sliding surface of the magnetic recording medium, which is set to an extent that the magnetic flux is not saturated. .

FIG. 4 shows the magnetic field strength within the magnetic recording medium 5 directly below the main magnetic pole 2 in the perpendicular magnetic head configured as described above, the end face of the auxiliary yoke 1a facing the magnetic recording medium 5, and the gap between the magnetic recording medium 5 ( FIG. 7 is a characteristic diagram showing the relationship between the distance b) and the pseudo gap a as a parameter. The vertical axis represents the magnetic flux density T for signals and the magnetic flux density T for noise, and the horizontal axis represents the air gap b between the auxiliary yoke and the magnetic recording medium. Note that the solid line represents the magnetic flux density within the magnetic recording medium for recording signals, and the broken line represents the magnetic flux density within the magnetic recording medium for noise due to ghosts. When the gap b between the auxiliary yoke 1a and the magnetic recording medium becomes 50 μm or more, the magnetic flux density for the signal decreases only slightly, but the magnetic flux density in the magnetic recording medium for noise caused by ghosts decreases rapidly. The gap b should be 50 to 100 μm because the regeneration efficiency will decrease.
is suitable.

Note that this noise occurs because the magnetic flux concentrates on a part of the tip of the auxiliary yoke 1a, and the number of magnetic fluxes interlinking the coils changes rapidly. In order to prevent the generation of this large noise, it is preferable to further provide a portion parallel to the sliding surface of the magnetic recording medium on the end surface of the auxiliary yoke 1a facing the magnetic recording medium 5 to such an extent that the magnetic flux is not saturated.

〔Effect of the invention〕

As explained above, the present invention includes a magnetic main pole yoke, a magnetic main pole provided on the main pole yoke and whose end face faces the magnetic recording medium, and a winding window, and a magnetic path for magnetic flux passing through the main pole. and a magnetic auxiliary yoke whose end face faces the magnetic recording medium, and a winding provided through the winding window, wherein the auxiliary yoke and the main magnetic pole at the portion facing the magnetic recording medium. the void of
By setting the distance between the end face of the auxiliary yoke facing the magnetic recording medium and the space between the magnetic recording medium and the magnetic recording medium to be within the range of 50 to 100 μm, high recording efficiency and high playback efficiency can be achieved. This has the effect of providing a perpendicular magnetic head that can hold the magnetic head and reduce ghosts in the reproduced waveform, thereby preventing the generation of noise.

Furthermore, by setting the gap between the end surface of the auxiliary yoke 1a facing the magnetic recording medium and the magnetic recording medium in the range of 50 to 100 μm, ghosts in the reproduced waveform can be reduced, and as a result, a perpendicular magnetic head that can prevent the generation of noise can be realized. can get.

[Brief explanation of drawings]

FIG. 1 is a front view showing a perpendicular magnetic head according to the present invention, and FIG. 2 is a characteristic diagram showing the relationship between the magnetic field strength and the pseudo gap in the magnetic recording medium directly under the main magnetic pole in the perpendicular magnetic head according to the present invention. Third
The figure is a front view showing a perpendicular magnetic head according to an embodiment of the present invention, and FIG. 4 is a diagram showing the magnetic field strength within the magnetic recording medium immediately below the main pole and the magnetic recording medium of the auxiliary yoke in the perpendicular magnetic head according to an embodiment of the present invention. FIG. 5 is a characteristic diagram showing the relationship between the end face facing the magnetic recording medium and the air gap of the magnetic recording medium. FIG. 5 is a front view showing a conventional perpendicular magnetic head. In the figure, 1a is an auxiliary yoke, 1b is a main magnetic pole yoke, 2 is a main magnetic pole, 3 is a winding, 5 is a magnetic recording medium, 6 is a winding window, and a is an auxiliary yoke at the part facing the magnetic recording medium. The gap (pseudo gap) between the main pole and b is the gap between the end face of the auxiliary yoke facing the magnetic recording medium and the magnetic recording medium. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. A magnetic main pole yoke, which is provided with a magnetic main pole whose end face faces the magnetic recording medium, and a winding window, which serves as a magnetic path for magnetic flux passing through the main pole. and a magnetic auxiliary yoke whose end face faces the magnetic recording medium, and a winding provided through the winding window, wherein the auxiliary yoke and the main magnetic pole are connected at the portion facing the magnetic recording medium. 1. A perpendicular magnetic head, characterized in that the gap is in the range of 70 to 250 μm, and the gap between the end face of the auxiliary yoke facing the magnetic recording medium and the magnetic recording medium is in the range of 50 to 100 μm. 2. The perpendicular magnetic head according to claim 1, characterized in that the space between the auxiliary yoke and the main magnetic pole at the portion facing the magnetic recording medium is in the range of 100 to 200 μm.