JPS61258312A - Vertical magnetic head - Google Patents

Abstract

PURPOSE:To obtain a vertical magnetic head having high recording efficiency and high reproducing efficiency by specifying the gap formed between a main magnetic pole and an auxiliary yoke set at a counter part against a magnetic recording medium. CONSTITUTION:A gap (artificial gap) (a) between a main magnetic pole 2 and an auxiliary yoke 1a set at the counter part against a magnetic recording medi um 5 is set at 150mum in this example (usually in a range of 70-250mum). Then a nonconductive magnetic material liek glass, etc. is molded into the gap (a). The magnetic flux which does not pass through the medium 5 and leaks out is increased between the pole 2 and the yoke 1a when the gap (a) is less than 70m. Then the vertical magnetic field intensity is reduced. While the magnetic flux induced up to the yoke 1a is reduced at a place right under the pole 2 when the gap (a) is larger than 250mum. The magnetic field intensity is increased at a place right under the pole 5 when the gap (a) is kept within a 70-250mum range and then becomes maximum in a 100-200mum. This secures high recording/ reproducing efficiency.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a perpendicular magnetic head (with improved recording and reproducing efficiency).
-It is related to

[Conventional technology]

Conventionally, as this type of perpendicular perpendicular magnetic head, there has been one shown in FIG. In the figure, (1a) is an auxiliary yoke made of magnetic ferrite, etc., (2) is permalloy,
The main pole consists of a ferromagnetic thin film formed by vapor deposition, sputtering, etc. of Co-Zr-Nb, etc., (3) is the coil conductor of the winding, (4) is a non-conductive non-magnetic material such as glass, +51 is A magnetic recording medium such as a magnetic tape or a magnetic disk, (a) is a pseudo gap, and the main magnetic pole (21) and the auxiliary yoke (1a)
is the distance between.

A conventional perpendicular magnetic head is constructed as described above, and a current is passed through the coil conductor wound around the main pole (2).Therefore, magnetic flux is generated. The generated magnetic flux flows inside the main magnetic pole (2) with high magnetic permeability, and is transferred to the magnetic recording medium (5).
is magnetized, and magnetic flux is induced in the auxiliary yoke (1a).

[The problem that the invention attempts to solve]

In the conventional perpendicular magnetic head as described above, since the pseudo gap (al) has several fins, the magnetic flux induced from the main magnetic pole (2) through the magnetic recording medium (51) to the auxiliary yoke (la) weakens and the recording There was a problem in that the efficiency and regeneration efficiency decreased.

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, the main pole yoke is provided with a magnetic recording medium (two opposing magnetic main poles, a winding window is provided, and the magnetic path of the magnetic flux passing through the main pole is connected to the end face of the main pole yoke). 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. 70-25
0) gn range.

[Effect]

In this invention, the gap between the auxiliary yoke and the main magnetic pole in the part facing the magnetic recording medium is narrowed to 250P or less (by which the magnetic flux induced in the auxiliary yoke is stronger than that in the main magnetic pole. Auxiliary yoke directly without passing through the magnetic recording medium! = Since more magnetic flux leaks, 70
By setting the thickness in the range of ~250 μm, the recording efficiency and reproduction efficiency of the perpendicular magnetic head are improved.

〔Example〕

′! FIG. 161 is a front view showing a perpendicular magnetic head according to an embodiment of the present invention, and (2) to (5) are similar to the conventional head. (1a) is an auxiliary yoke made of magnetic ferrite or the like as in the prior art, and (1b) is a main pole yoke made of magnetic ferrite or the like. The end surface of the main magnetic pole (21) faces the magnetic recording medium (51). is facing the magnetic recording medium. Cal represents the air gap (pseudo gap) between the auxiliary yoke (la) and the main magnetic pole (2) at the part facing the magnetic recording medium (5), and this gap is in the range of 70 to 250 μm. The case was 150P, and a non-conductive magnetic material such as glass was molded between them.

Note that the air gap (bl, which will be described later), is the one in the operating state and includes 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 (21) in the perpendicular magnetic head configured as described above. ) and the gap between the end face facing the magnetic recording medium (
FIG. 3 is a characteristic diagram showing b) (see FIG. 3) as a parameter. The vertical axis is the magnetic flux density σ), and the horizontal axis is the pseudo gap (al
It represents. When the pseudo gap (al) becomes 70PL or less, the magnetic flux that leaks between the main pole (2) and the auxiliary yoke (la) without passing through the magnetic recording medium increases, and the vertical magnetic field strength immediately below the main pole decreases.

In addition, when the pseudo gap (a) is 250 prL or more (2), the magnetic flux induced even to the auxiliary yoke (1a) decreases. When (the magnetic field strength directly under the two main magnetic poles increases and further increases from 100P to 200P) an
It becomes the largest in the following cases, and high recording efficiency and playback efficiency can be expected.

From this result, it is possible to set the pseudo gap (a) to 70 to 250P (- to create a perpendicular magnetic head with better performance;
By setting the value to 00 to 200P, a product with even better performance can be obtained.

In the above embodiment, the ghost of the reproduced waveform becomes a big problem when long wavelength recording and reproduction is performed, and appears as noise.

FIG. 3 is a front view showing a perpendicular magnetic head according to another embodiment of the present invention, in which the distance between the end surface of the auxiliary yoke (1a) facing the magnetic recording medium and the magnetic recording medium +51 sliding surface is 5Q7m or more and 100P or less. A gap (b) is provided and the auxiliary yoke (1a)
End face 1 facing the magnetic recording medium: A parallel portion is provided. In the figure, (1)) is the auxiliary yoke (1a)
and the distance to the magnetic recording medium (5) sliding surface, (C) is the length of the magnetic recording medium sliding surface of the auxiliary yoke (the length of the two parallel parts,
To the extent that the magnetic flux is not saturated (- provided).

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 and the end surface of the auxiliary yoke (1a) facing the magnetic recording medium (51). It is a characteristic diagram showing the relationship between the air gap (distance b) of the magnetic recording medium (5) using 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; The axis represents the air gap CI) between the auxiliary yoke and the magnetic recording medium. The solid line represents the magnetic flux density within the magnetic recording medium for the recording signal, and the broken line represents the magnetic flux density within the magnetic recording medium for the ghost (=noise 1:
If the value exceeds 100%, the magnetic flux density for the signal will only slightly decrease, but the magnetic flux density in the magnetic recording medium for noise caused by ghost 1 will decrease rapidly. (bl is 5
0 to 100μ is suitable.

Note that this noise occurs because the magnetic flux concentrates on a portion of the tip of the auxiliary yoke (1a), and the number of magnetic fluxes interlinking the coils changes rapidly. In order to prevent this large noise from occurring, it is preferable to further provide a magnetic recording medium sliding surface (parallel portion) on the end face 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 the end face of the magnetic recording medium (including two opposing magnetic auxiliary yokes and a winding provided through the winding window), the auxiliary yoke and the main By setting the gap between the magnetic poles to a range of 70 to 250 μm, it is possible to obtain a perpendicular magnetic head with high recording efficiency and high reproduction efficiency.

Furthermore, by setting the air gap between the end face of the auxiliary yoke facing the magnetic recording medium and the magnetic recording medium in the range of 50 to 100/a, ghosts in the reproduced waveform can be reduced, and as a result, the occurrence of noise can be prevented in the perpendicular magnetic head. is obtained.

[Brief explanation of drawings]

FIG. 1 is a front view showing a perpendicular magnetic head according to an embodiment of the present invention, and FIG. 2 is a front view showing a perpendicular magnetic head 1 according to an embodiment of the present invention.
Figure 3 is a front view showing a perpendicular magnetic head according to another embodiment of the present invention, and Figure i4 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. A characteristic diagram showing the relationship between the magnetic field strength in the magnetic recording medium directly under the main pole and the gap between the end face of the auxiliary yoke facing the magnetic recording medium and the magnetic recording medium in a perpendicular magnetic head of another embodiment. FIG. 3 is a front view showing a perpendicular magnetic head of FIG. In the figure, (1a) is the auxiliary yoke, (1b) is the main pole yoke, (21 is the main pole, (31 is the winding, (51 is the magnetic recording medium, (6) is the winding window, (al is the magnetic The air gap (pseudo gap) between the auxiliary yoke and the main magnetic pole at the part facing the recording medium, (bl is the air 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 refer to the same - or a corresponding portion.

Claims (3)

[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 window for winding, which serves as a magnetic path for the magnetic flux passing through the main pole, and whose end face faces the magnetic recording medium. In a device comprising a magnetic auxiliary yoke facing the magnetic recording medium and a winding provided through the winding window, the air gap between the auxiliary yoke and the main magnetic pole at the portion facing the magnetic recording medium is 70 to 70. A perpendicular magnetic head characterized in that the magnetic field is in the range of 250 μm. (2) The perpendicular magnetic head according to claim 1, characterized in that the gap 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. (3) The perpendicular magnetic head according to claim 1 or 2, characterized in that 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.