JPS6159613A - Magnetic head - Google Patents

Abstract

PURPOSE:To work a magnetic head easily similarly to a single gap head without causing the reduction of an effective track width by constituting gap parts wider than a gap part of a magnetic head on both sides of this gap part of the magnetic head. CONSTITUTION:Gap parts which are larger than a minimum gap and have a uniform or varying width are formed on both sides of the minimum gap of the magnetic head having three gap parts. Data is written on a medium by the trailing edge of the head gap. If different data are written because of the occurrence of off track, the read output due to the wider gap parts of the head is zero, and only new data due to the narrow gap part is read out. Thus, the effective track width related to reading is determined by the narrow gap part independently of the off track quantity, and the head is worked easily similarly to a single gap head.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a magnetic head.

[Conventional technology]

In the past, in a magnetic recording apparatus without a tracking servo mechanism, a magnetic input/drive having a structure as schematically shown in FIG. 2 was required. In the figure, the densely shaded area schematically shows part of the core. The gap in the center is the writing/retracting φ
The gaps placed on both sides of the gear knob indicate the erase (2)) gap.

Consider, for example, the case where such a structure is necessary, as shown in FIG. 3, in which the RAW gap is connected to a magnet head. In other words, as shown in FIG. 3(A), this magnetic head writes certain data, and then the third
If different data are written on a surface where off-track occurs, as shown in FIG. 3(B), the result will be a scratch where two different data exist on the same track. As a result, in the worst case, the magnetic head will read two different data at the same time, as shown in FIG. 3(a). With this, accurate magnetic recording cannot be performed.

Let us consider the same thing regarding the magnetic head having the structure shown in FIG. In this case, even if off-track occurs as shown in FIG. 2 ω), unnecessary data is erased in the E gap. Therefore, as shown in FIG. 2 (cl), unnecessary data is not read out as in the case of FIG. 3 (C).

For the above-mentioned reasons, conventionally it was necessary to have a magnetic head with a structure as schematically shown in Fig. 2. [Problem that the invention aims to solve] However, there were the following problems. it is.

1> Complicated processing is required: manufacturing five independent magnetic heads, processing them into a predetermined shape, inserting silk, and joining them.

2) As shown in FIG. 2(C), although different data cannot compete with each other, the effective track width becomes narrower, resulting in a decrease in head output.

It's like saying.

The present invention is intended to solve these problems, and its purpose is to provide a single-gap head that is as easy to process as the single-gap head shown in FIG. There are some FCs that introduce magnetic fields that do not involve a reduction in the effective drag/I margin.

[Means for solving problems]

In the present invention, a gap is provided in a part of a magnetic circuit, and magnetic recording is performed on a medium using a magnetic field generated in the gap.

Alternatively, in a magnetic head for positioning and reproduction, the gap is made up of at least three parts, and the part with the smallest gap has constant or variable gaps larger than the gap on both sides. This magnetic head is characterized by having one or more structures.

[Effect]

An example of the operation of the magnetic head according to the above configuration of the present invention [
I will explain further.

FIG. 1 conceptually shows the operation of an embodiment of the magnetic head according to the present invention in the same way as FIGS. 2 and 3.

First, as shown in FIG. 1(A), consider writing data to a medium using this head. At this time, data is written to the medium at the trailing edge of the write head gap.

After that, assume that different data is written in a state where off-track occurs. Then, as shown in FIG. 1(B)K, two pieces of data are written as in the case of FIG. 3.

Let us consider reading out this data in the state shown in FIG. 1 (0). First, FIG. 4 schematically shows the relationship between the recording wavelength λ on the medium and the reproduction output V. In the figure, the solid line indicates the case of a head with a narrow gap, and the broken line indicates the case of a head with a wide gap. As is clear from the figure, the output indicated by the broken line is generally lower than that indicated by the solid line.

Furthermore, there are cases in which the solid line indicates an output, and there are cases in which the broken line indicates almost zero output. This f'L is the case where the head gap shown by the broken line is an integral multiple of the recording wavelength. - If the above-mentioned conditions are satisfied, the reading/reading output due to the wide part of the gear knob of the magnetic head in FIG. 1(0) becomes zero. In other words, although there are two pieces of data, new and old, on the track, the data that is output by the reader is the narrow part of the gap, that is, the input of new data. Further, the effective track width involved in this readout is determined only by the width of the narrow portion of the gap, regardless of the amount of off-track.

As described above, according to the structure of the present invention, the problems of the conventional magnetic head described above can be solved.

〔Example〕

FIG. 5 schematically shows some structures of a magnetic head according to the present invention.

FIG. 5 (+) is given as an example of the above, and shows a structure in which each of the three has a fixed gap.

FIG. 5(B) I-t is an example configured with a constant gap and a continuously changing gap portion.

FIG. 5(C) is an example in which the structure of Q3) is arranged axially symmetrically. In addition to this, a structure in which (A) is made axially symmetrical is also possible.

FIG. 5(D) is an example in which the structure according to the present invention consists of four or more parts.

In addition to these, more complex versions with their own combinations of lectures are also possible.

Figures 1 to 5 show the requirements of the present invention conceptually and schematically.
This is a representation, and the dimensional ratio of each part does not correspond to the actual one.

〔Effect of the invention〕

As described above, according to the present invention, although it is structurally a single head, it has the same effect as the conventional combined Mw head, E head, and E head. This has the effect that it is possible to realize a magnetic head in which the effective track width does not change from the off-track '1rkVc.

[Brief explanation of drawings]

FIG. 1 schematically shows the relative positional relationship between a head and a track during magnetic writing and reading according to the present invention. In the figure, the shaded area indicates the core, the arrow indicates the direction of movement of the head, and (A) 1-t data writing λ
(B) shows the rewriting of data when there is an off-track, and (C) shows the case when a reader is sent out. FIG. 2 schematically shows the relative positional relationship between the head and the tractor in a conventional head having an erase gap. In the figure, arrows and (Al(Bl, (01
is based on Figure 1. Figure 3 is a diagram showing the case of a conventional head without an erase gap, (A), (B), and (c) are diagrams of Figures 1 and 2.
Be busy. FIG. 4 is a diagram schematically showing the relationship between the recording wavelength on the medium and the read/output output. In the figure, the solid line indicates the case of a narrow gear knob.
The dashed line indicates the case of a wide gap. FIGS. 5A, 5B, 5C, and 5D schematically show magnetic heads according to the present invention. In the figure, the shaded part schematically shows the core part. Above λ Fig. 4 □ Near Z Mouth Z Otori Z = CD) % Decoy Z Wa Z Ko Z Ko Z Coff feather

Claims (1)

[Claims] In a magnetic head that provides a gap in a part of a magnetic circuit and performs magnetic recording on a medium using a magnetic field generated in the gap, or detects and records/reproduces the magnetic field generated by the medium using the gap, The void portion is comprised of substantially three portions in terms of void spacing, and on both sides of the portion having the substantially smallest void spacing, the void portion is larger than the void spacing and has a constant or varying spacing. A magnetic head characterized by having a structure in which each gap has one or more.