JPS6323774Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is a magnetic head that combines a recording/reproducing head and an erasing head, specifically a recording/reproducing head with a main gap for recording and reproducing on the front side, and a magnetic head that combines a recording/reproducing head and an erasing head. The present invention relates to a combination type magnetic head comprising an erasing head disposed on both sides of a magnetic medium and having an erasing gap that covers the tracks on the magnetic medium and limits the tracks to be recorded or recorded.

Generally, in a magnetic recording device, a magnetic drum,
When reproducing a recording on a magnetic medium such as a magnetic disk or magnetic tape, a disturbance signal may be generated based on positioning errors in a direction transverse to the direction of travel of the magnetic medium. Such interference signals occur when the recording/reproducing gap (main gap) of the magnetic head is not precisely positioned on the track to be reproduced on the magnetic medium, but partially covers the side tracks.
This may occur when the recording on the track on this side is played back, or when the previous recording was not completely erased when recording on the track. In order to prevent interference signals due to positioning errors of the magnetic head, magnetic heads of the type in which erasing heads are arranged on both sides of the recording/reproducing head have been known. One erase head covers the track to define one side of the main track, and the other erase head covers the other side of the same main track. During a recording operation, both the recording/reproducing head and the erasing head are energized, thereby erasing a predetermined width on both sides of the track simultaneously with the recording operation. The width to be erased by the erasing head depends on the accuracy of the positioning mechanism for positioning the magnetic head on a given track. In recent years, with the demand for miniaturization of magnetic recording/reproducing devices, track densities have been increasing for high-density recording.

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. In the tunnel erase system shown in FIG. 1, erase gaps 3 and 4 of erase heads 1 and 2 extend in a direction perpendicular to the running direction of the magnetic medium.
Note that the arrows indicate the running direction of a magnetic medium, such as a magnetic tape, during recording and reproduction. The recording/reproducing gap 6 of the recording/reproducing head 5 is formed at a position shifted upstream from the erasing gaps 3, 4 in the traveling direction of the magnetic medium, but in this system, the recording/reproducing gap 6 and the erasing gaps 3, 4 are both parallel to each other. It is. The advantage of this structure is that it is somewhat easier to manufacture than the straddle type shown in FIG. 2, which will be described later.
However, in this structure, the magnetic flux generated in the effective gap of the erasing heads 1 and 2 affects the magnetic flux in the effective gap 6 caused by the recording/reproducing head 5, and furthermore, placing the erasing gaps 3, 4 in this position does not affect the recording/reproducing gap. This is inappropriate when reproducing a signal recorded by 6. Since the magnetic fluxes of both the erasing heads 1, 2 and the recording/reproducing head 5 are in the same direction, mutual interference occurs between these magnetic fluxes. Furthermore, it is difficult to concentrate the erase magnetic flux by the erase gaps 3 and 4 on the side edges of the recording/reproducing track. On the other hand, in the straddle erase type magnetic head shown in FIG. 2, the erasing heads 1 and 2 are arranged on both sides of the recording/reproducing head 5 with a gap-forming non-magnetic material such as resin, glass, or tetan foil interposed therebetween. The erasing gaps 3 and 4 extend parallel to the running direction of the magnetic medium on the front surface of the magnetic head, and are perpendicular to the gap 6 of the recording/reproducing head 5. The magnetic flux directions of the recording/reproducing gap 6 and the erasing gaps 3, 4 are no longer in the same direction, so that the influence of the magnetic flux of the erasing gap on the recorded signal and interference with the magnetic circuit of the recording/reproducing head is 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 Figure 2 is
A major difficulty arises when the width of the track to be regenerated is narrow, ie, a high density track. In practice there are always transitions on both sides of the erased track.
This portion extends into the recording/reproducing track a distance from the outer edge of the recording/reproducing track at least equal to the width of the erasure gap adjacent the recording/reproducing track. In this transition, the magnetization distribution of the recorded track gradually decreases towards the edges. This transition on both sides of the recording/reproducing track has a very undesirable effect on the relative strength of the recorded signal.

The present invention utilizes the advantages of the above-mentioned two types of combined magnetic heads while eliminating their disadvantages.The present invention utilizes the advantages of the above-mentioned two types of combined magnetic heads while eliminating their disadvantages. It is an object of the present invention to provide a combination type magnetic head which can be made negligibly small compared to the width of a track and which is easy to manufacture.

The present invention provides a magnetic head that combines a recording/reproducing head and an erasing head, in which the erasing head is arranged on both sides of the recording/reproducing head, and the erasing head is arranged between the recording/reproducing head and the erasing head at least on the magnetic medium running surface in front of the magnetic head. The erasing gap is formed in a part of the erasing head parallel to the direction of travel of the magnetic medium, and the erasing gap extends in an arcuate manner to the outside of the erasing head.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 3 is a schematic diagram of the front portion of the combination type magnetic head according to the embodiment of the present invention, that is, the magnetic tape running surface. 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 running direction of the magnetic tape (indicated by the arrow). Erasing heads 1 and 2 are arranged on both sides of the recording/reproducing head 5. Further, a core 11 of the erase head is separately joined to the erase heads 1 and 2,
A winding 12 is formed on the core 11 . The coil 12 and each coil 14 may be connected independently or in series or in parallel from a power source. This erase head has a core 10 having an erase gap 8 and a rear core 13 to which an erase coil 14 is attached, as shown on one side in FIG.
It consists of A non-magnetic material such as resin, glass or titanium foil is sandwiched in the front core 10 in an arc shape from the outer part 10a to the inner part 10b, and the same non-magnetic material is then placed in a part of the inner part 10b. Exposed and pasted. The connecting portion between the non-magnetic material sandwiched between the front core and the non-magnetic material exposed on the inner side portion 10b of the front core is smoothly joined as shown in the figure. The inner side 10b of the front core 10 is polished to a flat surface and fixed to the side of the recording/reproducing head 5. In this state, as shown in FIG. 3, the erasing head 2 has an erasing gap parallel to the running direction of the magnetic tape made of the non-magnetic material between it and the recording/reproducing head 5, and an arc-shaped erasing gap in the front core. will be formed. The same goes for the other erasing head 1, and as shown in FIG.
A gap parallel to the running direction of the magnetic tape and an arcuate gap following the gap are formed between the magnetic tape and the magnetic tape. FIG. 4 is a schematic perspective view of the above-mentioned erasing heads 1 and 2 assembled into the recording/reproducing head 5. As shown in FIG.

In the embodiments shown in FIGS. 3 to 5, the arc-shaped erase gap formed in the front core of the erase head is convex in the direction facing the running magnetic tape during recording and reproduction, and this arc-shaped erase gap is formed in the front core of the erase head. Although this is an example in which an erasing gap extends from the gap parallel to the downstream side with respect to the running direction of the magnetic tape, the present invention is not limited to this embodiment, and as shown in FIG. Following the recording/reproducing gap 6, a parallel erasing gap is formed on the traveling side in the magnetic tape running direction, and arc-shaped erasing gaps 7, 8 are formed from this parallel erasing gap toward the outside of the erasing heads 1, 2. You may.

In the erasing gaps 7 and 8 according to the present invention, the direction of the erasing magnetic flux is different from the direction of the magnetic flux of the recording/reproducing gap 6 in both the portion parallel to the magnetic tape running direction and the arc-shaped portion, so that the erasing magnetic flux is There is little interference with the magnetic circuit of the recording/reproducing head 5. By making the erase gap arc-shaped, the effective gap length can be made longer than that of a linear gap, and magnetic flux with a correspondingly higher density can be obtained, resulting in a smaller overall structure. The erase current may also be small. Since the erase magnetic flux is concentrated on the sides of the read/write head, it does not affect adjacent tracks, providing a noiseless and effective erase function. This combination type magnetic head is easier to manufacture than the tunnel erase type one shown in FIG.

[Brief explanation of drawings]

1 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 showing an example of a combination type magnetic head according to the present invention. FIG. 5 is a perspective view of an erasing head applied to the present invention, and FIG. 6 is similar to FIG. 3 showing another embodiment of the present invention. This is a schematic diagram. 1, 2... Erasing head, 5... Recording/reproducing head, 6... Recording/reproducing gap, 7, 8... Erasing gap, 10... Front core of erasing head, 13...
...Erasing head rear core.

Claims (1)

[Scope of utility model registration request] In a magnetic head that combines a recording/reproducing head and an erasing head, erasing heads are arranged on both sides of the recording/reproducing head, and an erasing gap is formed in a part between the recording/reproducing head and the erasing head parallel to the direction in which the magnetic medium runs. A combination magnetic head characterized in that the erasing gap extends in an arc shape to the outside of the erasing head.