JPS6323773Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention is a magnetic head that integrally combines a recording/reproducing head and an erasing head, specifically a recording/reproducing head having a main gap for performing recording and reproduction on the contact surface with a magnetic medium. The present invention relates to a combination type magnetic head comprising a head and an erasing head disposed on both sides of the recording/reproducing head 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 due to a positioning error in a direction perpendicular to the direction of travel of the magnetic medium. Such interference signals are generated when the recording/reproducing gap (main gap) of the magnetic head is not precisely positioned over the track to be reproduced on the magnetic medium, but partially covers the track on the side. This can occur when playing back a recording on a track, or when the previous recording is not completely erased when recording on a 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 erasing magnetic flux by the erasing 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, titanium foil, etc. The erasing gaps 3 and 4 extend parallel to the running direction of the magnetic medium at the magnetic medium contact surface 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 track to be regenerated has a narrow width, 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 is a combination of a recording/reproducing head and an erasing head, in which the erasing heads are arranged on both sides of the recording/reproducing head, and the erasing gap of the erasing head is located outside of the erasing head. parallel to the recording/reproducing gap direction,
Further, the inner portion is characterized in that it is formed into a continuously curved gap shape in an approximately L-shape so as to be perpendicular to the recording/reproducing gap.

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

FIG. 3 is a schematic view of the front part of the combination magnetic head according to the embodiment of the present invention, that is, the contact surface with the magnetic tape. 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 this recording/reproducing head 5. As shown on one side of this erasing head in FIG. 5, a substantially L-shaped erasing gap 8 is formed in the core (front core) on the side that contacts the recording/reproducing head. Referring to FIG. 5, the erasing head 2 of the present invention includes a front core 10 in contact with a recording/reproducing head and a rear core 13 having an erasing coil 14 attached thereto.
It consists of A non-magnetic material such as resin, glass or titanium foil is sandwiched in the front core 10 from the outer part 10a to the inner part 10b at right angles to the running direction of the magnetic tape (in the direction of the arrow). A magnetic material is exposed and attached to a part of the inner part 10b. A connecting portion (corner portion) 8a between the non-magnetic material sandwiched between the front cores and the non-magnetic material exposed on the inner side portion 10b of the front core is smoothly curved and 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, an L-shaped erase gap 8 (see FIG. 3) is formed between the erase head 2 and the recording/reproducing head 5 by the non-magnetic material. The corner portions of the L-shaped erasing gap are curved to form R portions as described above. The same goes for the other erasing head 1, and an L-shaped erasing gap 7 is formed between it and the recording/reproducing head 5 as shown in FIG. In this way, the L-shaped erase gaps 7, 8 are arranged parallel to the direction of the recording/reproducing gap 6 in the outer parts of the erasing heads 1, 2 and at right angles to the recording/reproducing gap 6 in the inner parts of the erasing heads 1, 2, respectively. The L
The curved part of the letter is curved into an R shape. FIG. 4 is a schematic perspective view of the above-mentioned erasing heads 1 and 2 assembled to the recording/reproducing head 5. As shown in FIG. A further separate erase head core 11 is combined and joined to the erase heads 1 and 2 to form a winding 12. The coil 12 and each erasing coil 14 may be connected independently or in series or in parallel from a power source. Erasing gap 7 with this shape,
8 is due to this structure because the direction of the magnetic flux in the gap part parallel to the running direction of the magnetic tape during recording and reproduction and in the R part of the corner thereof is different from the direction of the magnetic flux in the recording and reproduction gap 6. The erase magnetic flux rarely interferes with the magnetic circuit of the recording/reproducing head 5. By making the erase gaps 7 and 8 L-shaped, higher erase efficiency can be obtained than in the straddle type shown in FIG. 2, and the erase current may be smaller, leading to a corresponding reduction in size. This combination type magnetic head is also much 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 schematically showing the internal structure of a type magnetic head, and FIG. 5 is a perspective view of an erasing head applied to the present invention. 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 the erasing gap of the erasing head is the same as the recording/reproducing gap of the recording/reproducing head at the outer side of the erasing head. A combination type magnetic head characterized in that it is formed into a gap shape that is continuously curved in a substantially L-shape parallel to the direction and perpendicular to the recording/reproducing gap at the inner side.