JPS58194122A - Combined magnetic head - Google Patents

Abstract

PURPOSE:To decrease the width of a transition section, by placing erase heads in which plural cylindrical cores are placed separately on a tape running surface vertically, at both sides of a recording and reproducing head and using a narrow erase gap even if a position error exists. CONSTITUTION:The recording and reproducing head 5 is formed with a recording and reproducing gap 6 prolonged perpendicularly in the magnetic medium running direction, and the erase heads 11, 12 are placed at both sides of the head 5. The erase heads are constructed symmetrically at both sides of the recording and reproducing head, a couple of cylindrical cores 14, 15 are imbeded partially in a nonmagnetic member 13 separately toward the magnetic medium running direction each other, the axial lines of the cores 14, 15 are parallel mutually and vertical to the magnetic medium running surface, i.e., the front surface of the magnetic head, the cylindrical cores 14, 15 are linked each other at a rear core 16, and an erase coil 17 is wound on the core 16. The nonmagnetic substance part among the cylidrical cores 14, 15 and the head 5 forms an erase gap at the side of the erase head 11, and the side of the erase head 12 is constituted similarly, allowing to constitute a nearly T-shaped erase gap as a whole.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic head that integrally combines a recording/reproducing head and an erasing head. The present invention relates to a combination type air head comprising an erasing head disposed on both sides of the recording/reproducing head and having an erasing gap covering a trunk on a magnetic medium and defining a track to be recorded or recorded.

In general, in a magnetic recording device, when reproducing a recording on a magnetic medium such as a magnetic drum, magnetic disk, or magnetic tape, a disturbance signal is generated based on positioning errors in the magnetic medium's running direction [versus the lateral direction]. Sometimes. Such interference signals occur when the recording/reproducing gap (main gap) of the magnetic head is not precisely located on the trunk to be reproduced on the magnetic medium, but is partially overlapping one trunk.

VC also occurs when the recording on this side track is reproduced, or when the previous recording is not completely erased when recording on the track. ,
In order to prevent interference signals based on positioning errors of the magnetic head, a magnetic head of the type in which an erase head is placed in a part of the recording/reproducing head has been known. The bond confines one side of the main track.

The other erase head confines the other side of the same main trunk. During a recording operation, both the recording/reproducing head and the one-corner erasing head are energized, thereby simultaneously erasing (and erasing) one track in a predetermined width at the same time as the recording operation. It depends on the positioning mechanism N[[[[] for positioning the position tII:!11m1M onto a predetermined trunk.In recent years, with the demand for ultra-miniaturization of magnetic recording/reproducing devices, the track density has also increased for high-density recording. It has become to.

As such combination type magnetic heads, there are a tunnel erase type magnetic head shown in Fig. 1 and a straddle erase type magnetic head shown in Fig. 2, each of which has advantages and disadvantages. The tunnel erase method has an erase head of 1.2 and an erase gap of 3.4.
extends in a direction perpendicular to the direction of travel of the magnetic medium. Note that the arrow indicates the running direction of a magnetic medium, for example, a magnetic tape, during recording and playback, and the recording/playback gap 6 of the recording/playback head 5 is formed at a position shifted from the erase gap 3.4 in the running direction of the magnetic medium. However, in this system, both the recording/reproducing gap 6 and the erasing gap 3.4 are parallel. The advantage of this structure is that it is slightly easier to manufacture than the straddle type book shown in FIG. 2, which will be described later. but.

In this structure, the magnetic flux generated in the effective gap of the erase head 1.2 affects the magnetic flux in the effective gap 6 caused by the recording/reproducing head 5Vc, and furthermore, setting the erase gap 3.4 at this position is due to the recording/reproducing gap 6. It is unsuitable for reproducing recorded signals. Since the magnetic fluxes of both the erasing head 1.2 and the recording/reproducing head 50 are in the same direction,
Mutual interference occurs in these amounts of magnetic flux. Furthermore, it is difficult to concentrate the erase magnetic flux due to the erase gap 3.4 on the side edges of the recording/reproducing trunk. On the other hand, the straddle erase type magnetic head shown in FIG.
An erasing head 1.2 is arranged on both sides with a non-magnetic material such as resin, glass, titanium foil, etc. for gap formation, and erasing gaps 3 and 4 are parallel to the running direction of the magnetic medium in front of the magnetic head. The magnetic flux directions of the recording/reproducing gap 6 and the erasing gap 3.4, which extend at right angles to the gap 6 of the recording/reproducing head 5, are not in the same direction but are recorded in opposite directions. The influence of the magnetic flux of the erase gap on the recorded signal and the interference with the recording/reproducing magnetic circuit are minimized. The advantage of this structure is that it is possible to form a strong core as an erase head, and the magnetic head itself is relatively easy to manufacture. However, the structure shown in FIG. 2 has a major drawback when the width of the track to be reproduced is narrow, that is, when the track is high-density. One of the trunks that was actually erased
A transition part always occurs in a11@. This part extends from the outer edge of the recording/reproducing track to at least the recording/reproducing trunk.
It extends into the recording/reproducing track by a distance equal to the width of the erase gap IIm. In this transition, the magnetization distribution of the recorded track gradually decreases towards the VC edge. The presence of this transition in the recording/playback trunk 914 has a very undesirable effect on the relative strength of the recorded signal.

The present invention takes advantage of the advantages of the above-mentioned two types of combined magnetic heads and eliminates their disadvantages, and the width of the transition region can be reduced by a narrow erase gap even if there is a first-position error. It is an object of the present invention to provide a compact combination magnetic head that can be made negligibly small compared to the width of a recording/reproducing trunk and is easy to manufacture.

In order to achieve this object, an erasing head according to the present invention is formed by a combination magnetic henode F1% in which a plurality of cylindrical cores are embedded in a non-magnetic material so as to be spaced apart from each other and perpendicular to the running surface of the magnetic medium. is placed inside the throat for recording and playback.

Embodiments of the present invention will be described below with reference to one drawing.

FIG. 3 is a schematic view of the front portion of the combination magnetic head according to the embodiment of the present invention, that is, the magnetic medium running surface. Further, FIG. 4 shows the structure of the combination type magnetic head of this embodiment.
FIG. 2 is an enlarged perspective view. The recording/reproducing head 5 has the same structure as shown in FIGS. 1 and 2, and has a recording/reproducing gap 6 extending perpendicularly to the direction of travel of the magnetic medium (indicated by an arrow). In the MM section of the recording/reproducing head 5, an erasing head generally designated by reference numeral 11.12 is arranged.

Since the erasing head of this embodiment has a symmetrical structure on both sides of the recording/reproducing head 5, only one side will be described in detail. A pair of cylindrical cores 14, 15 are partially embedded in a non-magnetic material 13, such as barium titanate porcelain, at a distance from each other in the direction of travel of the magnetic medium. As shown, the axes of the cylindrical cores 14, 15 are parallel to each other and perpendicular to the magnetic medium running surface, that is, the front surface of the magnetic head. Further, this erasing head 11 is entirely covered by the wall of the non-magnetic material 13, at least on the side facing the head portion of the recording/reproducing head 50. The cylindrical cores 14,15 are connected to each other by a rear core 16, to which an erasure coil 17 is mounted. Further, as is clear from FIG. 4, the front core of the recording/reproducing head 5 is connected to the rear core 23 of the head, and this rear core 2
As mentioned above, the erasing head is located inside the recording/reproducing head 5, and the cylindrical core is on the wake of the recording/reproducing gap 6 in the direction in which the magnetic medium runs. It is arranged like this. Furthermore, one cylindrical core 14 in the erasing head 11 on one side and one cylindrical core 14 in the erasing head 12 on the other side.
' (FIG. 3) K is a jointed core 18 which is assembled together with the other cylindrical core 15 of the erasing head 11 and the other cylindrical core 15' of the erasing head 12 (the third In FIG. 1, a separate articulating core 19 is likewise assembled into a joint 1. Each articulating core l'8
, 19 are each equipped with a coil 20, 21. Rear core 16 of '11.12, l
Coil 20.21Fif installed between the coils l 7 and 17' and the erase head 11.12 installed at 6'.
They can be connected in series or in parallel to a common 'II source. In addition, in FIG. 3, 13' is the cylindrical core 14' on the other side,
15' is surrounded by a non-magnetic material, 16' is a cylindrical core l
4', l5', and the non-magnetic material 13 of the erasing head 11 on the opposite side, respectively. Corresponds to the rear core 16.

As shown in Figure 4, a reinforcing material 22 made of a non-magnetic material is fixed to the recording head 5 to reinforce its front core.

In such a configuration, in the erasing head 11, the non-magnetic material portion between the nine cylindrical cores 14 and 15 spaced apart from each other and between the cylindrical core 14 and the recording/reproducing head 5 is used as the recording/reproducing head. 50 is an erasing gap formed on one side, and on the other erasing head 12, there is a gap between the cylindrical cores 14 and 15' as well as a gap between the cylindrical cores 14' and 15'.
The non-magnetic material portion between 5' and the recording/reproducing head 5 becomes an erasing gap on the other side of the recording/reproducing head 5. With such a configuration, an approximately T-shaped erase gap is formed on both sides of the recording/reproducing head 50 as a whole.

In the combination magnetic head of the present invention, since the direction of the erasing magnetic flux due to the erasing gap is different from the direction of the magnetic flux of the sickle reading gap 6, the erasing magnetic flux does not interfere with the magnetic circuit of the recording/reproducing head 5. By making the erase gap into a modified T-shape made of a combination of circular arcs and straight lines, the effective gap length can be made longer than the conventional OL1 linear gap, and a magnetic flux crab with a higher density can be obtained. As a result, the overall structure can be made extremely compact. Since the erasing efficiency is good, the erasing current may also be small.

Because the erase magnetic flux is centered on the side of the recording/reproducing head.

This combined magnetic head provides an effective, noise-free ablation function without affecting adjacent trunks, and is also easier to manufacture than the tunnel erase method shown in Figure 1. .

The overall strength can also be increased. Although the illustrated embodiment shows an example in which two cylindrical cores are arranged on each side of the recording/reproducing head, the present invention does not necessarily require such a uniform arrangement.
However, two or more cylindrical cores of sea bream may be arranged. In addition, in the *m example shown, the cylindrical core is partially embedded in the non-magnetic material, and a part of it is exposed, but one cylindrical core is completely buried in the non-magnetic material. may be configured.

[Brief explanation of drawings]

41 and 2 are schematic diagrams showing an example of a conventional combination type magnetic head, FIG. 3 is a schematic diagram of a combination type magnetic head according to an embodiment of the present invention, and FIG. 4 is a schematic diagram of a combination type magnetic head according to an embodiment of the present invention. FIG. 2 is an enlarged perspective view showing the internal structure of the magnetic head in more detail. 1.2.11.12 -- Erasing head, 5 -- Recording/reproducing head. 6... Recording/playback gap. 13...Nonmagnetic material. 14, 14', 15, 15'... Cylindrical core, 16, 16'... Rear core of erase head, 18.
19...Connecting core, 17.17', 20.21.24...Coil. 23... Rear core of recording/reproducing head, 22... Reinforcement material. Agent Patent Attorney Toshiyoshi Somekawa Figure 1 Figure 2 1 Figure 3 Figure 4 Figure 9

Claims (1)

[Claims] A combination magnetic head characterized in that an erasing head in which a plurality of cylindrical cores are spaced apart from each other and embedded in a non-aqueous material is arranged on both sides of a recording/reproducing head.