JPH0224807A - magnetic head - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic head used in flexible magnetic disk drives, fixed magnetic disk drives, and the like.

Conventional technology FIG. 4 shows the configuration of a conventional magnetic head.

In FIG. 4, 1 is a gap for recording and reproducing, and 2
is the void to be erased. Each of the above air gaps has its own independent winding 3.4 and is also independently supplied with drive current.

Next, the operation of the above conventional example will be explained. FIG. 5 shows how the conventional magnetic head described above performs recording. In FIG. 5, reference numeral 11 indicates a track recorded by the recording gap 10. Usually, in a flexible magnetic disk drive device, the magnetic head is adjusted due to the magnetic head position adjustment error between the devices and the expansion and contraction caused by the temperature of the recording medium. A relative positional deviation (hereinafter referred to as off-track) with respect to the recording track position on the recording medium occurs.

As a result, a portion 12 of the previously recorded track may remain outside the recording track. Erasing gap 13
The remaining portion at the end of the recording track is erased, and is hereinafter referred to as trim erase. ) This is provided for the purpose of improving the SN ratio during reproduction.

In this manner, the conventional magnetic head described above achieves the above objective by providing a dedicated erasing gap in order to eliminate the influence of the previous history due to off-track.

However, since the conventional magnetic head described above has three gaps, it is difficult to ensure the track width of each gap and the relative positional accuracy of each gap. is necessary.

In particular, when track density is improved to increase recording capacity, the above constraints are extremely significant, and it is extremely difficult to mass-produce a large number of magnetic heads while ensuring the necessary dimensional tolerances. There was a problem.

The present invention solves these conventional problems,
It is an object of the present invention to provide an excellent magnetic head which has a single gap and can realize a function of trim-erasing both ends of a recording track.

Means for Solving the Problem In order to achieve the above object, the width of the track forming the gap for recording and reproduction is configured to be different on the recording medium inlet side and the recording medium outlet side. During recording, a head magnetic field is generated at the end of the gap in a direction perpendicular to the direction in which the recording medium runs, thereby realizing erasing at both ends of the track.

Effects The present invention has the following effects due to the above configuration. That is, because the previous history information in the recording medium is erased by the head magnetic field in the direction perpendicular to the direction in which the recording medium runs, it is possible to form trim-erased areas at both ends of the recording track even though it is a single gap. It has the effect of being able to.

As a result, there is no need to ensure the relative dimensional accuracy of the plurality of gaps as described above, so it is possible to provide a magnetic head that is extremely easy to manufacture.

Embodiment FIG. 1 shows the configuration of an embodiment of the present invention. In FIG. 1, 21 and 22 are cores made of soft magnetic material such as Mn-Zn7 elite, and 23 is the core 2.
1, 22 windings, and 24r/'i is an air gap filled with a non-magnetic material such as glass that magnetically separates the cores at minute intervals. In addition to the above-mentioned components, the magnetic head used in a flexible magnetic disk drive device is composed of a slider that protects the above-mentioned core made of a wear-resistant material such as ceramics, but the gist of the non-invention is Since there is no direct relationship, the explanation will be omitted.

The core is composed of a pair of members to form the gap, and these members have different track widths in the gap forming portion. That is, one side has a larger track width than the other, and as a result, the actual track width of the gap is regulated by the above-mentioned narrow track width, and a part of the above-mentioned wide track width does not form a gap at both ends. will remain in the

Next, the operation of the above embodiment will be explained. FIG. 2 conceptually illustrates the magnetic flux by enlarging the track end portion of the air gap. As shown by ^ and B in FIG. 2, the distribution of magnetic flux differs from the edge of the core having a narrow track width. That is, in the 8 parts having opposing cores, the magnetic flux is parallel to the medium running direction, but in the end part A, there is a magnetic flux having a component perpendicular to the medium running direction near the end of the narrow track width. The magnetic flux in the perpendicular direction in the above-mentioned section A has angles of 90 degrees with respect to the normal recording magnetic field vector, and its distribution is very gentle. Therefore, even if the head magnetic flux performs a switching operation in accordance with the signal and current applied to 1fsK, it is difficult to form a magnetization transition in the recording medium. Furthermore, even if a magnetization transition is formed, the magnetization vector in the medium that makes this transition is 90 degrees out of direction from the normal recording magnetization vector, so it cannot be read by the head.

As described above, when recording is performed using the head exemplified in this embodiment, the advantage that erase areas are formed at both ends of the original recording track can be realized with a head having a single cavity structure.

FIG. 4 shows the main part of the second embodiment, in which cores 40 and 41 having a track width of - between the tracks are shifted from each other in the track width direction to form a gap 42. .

In this embodiment as well, magnetic flux is generated in a direction perpendicular to the medium running direction as shown in the first embodiment, and the same effect can be obtained.

However, in the first embodiment, the recording track width is regulated by the narrow track width core, whereas in the structure of the second embodiment, the track width is determined by the amount of deviation of each core. Therefore, in the second embodiment, the assembly precision is more severe than in the first embodiment.

Note that the gist of the present invention is not limited to the material of the magnetic helad core, and is also effective for, for example, a so-called IVIIG head in which a thin film of a high saturation magnetic flux density material is coated on the air gap surface. be.

Effects of the Invention As is clear from the above embodiments, the present invention has the following effects.

(1) Since the trim erase effect can be realized with a single gap structure, stable recording against off-track can be realized with an inexpensive magnetic head.

(21) Since it has a single cavity structure, there is no need for spatial alignment of the erasing cavity and the recording/reproducing cavity, which was required in the past, and assembly is easy.

(3) Since the recording gap position and the erase position are on the same line, there is no need to adjust the timing of the start and end of recording and the start and end of erase, which was required in the past, and there is no need to consider variations in individual magnetic heads. .

(2) Conventionally, it has been difficult to process an erasing core with an extremely narrow track width for a high track density head, but since there is no erasing core, the above-mentioned difficult processing is not required.

(@ No need for an erase drive current supply circuit, simplifying the electronic circuit.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a magnetic head in an embodiment of the present invention, FIG. 2 is a conceptual diagram showing the magnetic flux distribution of the main parts of the head, and FIG. 3 is a front view of a magnetic head in a second embodiment.
FIG. 4 is a sketch of a conventional magnetic head, and FIG. 5 is a conceptual diagram showing how the conventional magnetic head writes to a recording medium. 21.22.40.41...Core, 24.42
... air gap, 23 ... winding. Name of agent: Patent attorney Shigetaka Awano and 1 other person1
Figure 2 Mortar type Figure 3 Figure

Claims (1)

[Claims] A gap made of non-magnetic material is formed by a pair of soft magnetic materials,
A magnetic head in which one or both of the track widths of each of the pair of soft magnetic materials is larger than the recording track width, and there is only one gap.