JPS63229609A - Both sides type magnetic head - Google Patents

Abstract

PURPOSE:To sufficiently read and write a bit of information even from and on a recording medium having a high coercive force or a recording medium having a thick magnetic film by using a ferromagnetic body to attach a magnetic material having a high permeability to a part of a slider in the vicinity of the gap of a read/write core consisting of a ferrite. CONSTITUTION:A read/write core 1 of a tunnel erase type magnetic head is provided with a read/write gap 3 and a gap nearby core 2 on the side face of the gap 3. The gap nearby core 2 consists of ferromagnetic materials having a high saturation magnetic flux density like a 'Sendust(R)', an amorphous magnetic material, or 'Permalloy(R)'. Since a ferrite is generally used as materials of the main core (read/write core 1), the high frequency characteristic and the wear resistance are satisfactory; and further, the saturation magnetic flux density is raised because ferromagnetic materials like 'Permalloy(R)' are used as materials of a read/write gap nearby core 3. Thus, the information is sufficiently written on and read from even the recording medium having a high coercive force or the recording medium having a thick magnetic film.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a double-sided magnetic head used in flexible disk devices used in computer storage devices and the like.

Conventional technology Conventionally, double-sided magnetic heads used in flexible disk devices, etc., have a core made entirely of one type of magnetic material such as ferrite and a non-magnetic slider such as barium titanate. Writing and reading were □.

Problems to be Solved by the Invention However, since the core material of conventional magnetic heads generally uses ferrite, the saturation magnetic flux density (BS) cannot be increased by more than 3,000 to 5,000 Gauss (Qauss). First, the problem was that it was not possible to write sufficiently on recording media with high coercive force (H) or with thick magnetic films.The HC of ferrite core material is limited to 800 oersted (Oe) or less. Ta.

The present invention solves these conventional problems and provides an excellent double-sided magnetic head that can write and read data satisfactorily even on recording media with high coercive force (H) and recording media with thick magnetic films. The purpose is to provide

Means for Solving the Problems In order to solve the above problems, the present invention uses a ferromagnetic material such as permalloy in the vicinity of the cap of the read/write core made of ferrite, and a part of the members constituting the slider. , the structure is such that a magnetic material with high magnetic permeability is attached.

Operation The present invention has the above-mentioned configuration, which enables sufficient writing and reading even on recording media with a high coercive force (H) or a recording medium with a thick magnetic film. This makes it possible to reduce crosstalk in which the magnetic flux of one side becomes noise in the read/write core on the other side.

EXAMPLE The structure of a double-sided magnetic head according to an example of the present invention will be described below. Fig. 1 is a perspective view showing the external appearance of this embodiment, Fig. 2 is a front view of the read/write core of this embodiment, Fig. 3 is a bottom view of the read/write core of this embodiment, and Fig. 4 is a bottom view of the read/write core of this embodiment. FIG. 3 is a front view showing an example of use of the example in this section.

In FIGS. 1 to 4, reference numeral 1 denotes a read/write core of a tunnel erase type magnetic head, which includes a read/write gap 3 and a core 2 near the gap provided on the side surface of the gap 3. The core 2 near this gap has a saturation magnetic flux density (
B3) is made of ferromagnetic materials such as sendust, amorphous magnetic material, and permalloy. 5a15
b is an erase core in which an erase gap 4 is provided. Reference numeral 7 denotes a non-magnetic slider for molding the read/write core 1 and erase cores 5a and 5b, and is made of aluminum, barium titanate, or the like. 8 is a read/write coil wound around the read/write core l, 9 is an erase core 5a15b
The erasing coil 10 is wound around the magnetic slider 11 attached to the end face of the non-magnetic slider 7, and is a recording medium that can be written on and read from the front and back sides.

Next, the operation of the present invention will be explained.

In Figures 1 to 4, the main core material (read/write core 1) is generally made of ferrite, which has good high frequency characteristics and wear resistance. Since a magnetic material is used, a large saturation magnetic flux density (B11) can be obtained, and even recording media with high coercive force (He) and recording media with thick magnetic films can be written and read sufficiently.

Further, as shown in FIG. 4, the magnetic flux of the read/write core 1 on the back side is shielded by the magnetic sliders 10a and 1o without being affected by the read/write core 1a on the front side.

These situations will be explained using characteristic diagrams. Figure 5 is a characteristic diagram of write current vs. overwrite mosilation, Figure 6
The figure is a characteristic diagram of write current vs. crosstalk, and FIG. 7 is a characteristic diagram of write current vs. resolution, in which the conventional example and the embodiment are compared.

In Figure 5, a magnetic head with a gap length of 0.9 μm and a magnetic film thickness of 2.0 μm THC = 650 Oersted (Oe)
It shows the survival rate of old signals when a signal is written on the medium and a new signal is overwritten on top of it. As shown in Figure 5, in the conventional example, write current =
At 10mA the override modulation is -24
In terms of dB, it cannot meet the standard of less than 26 dB, which is the practical value.

On the other hand, in the example, -40 dB can be secured, which fully satisfies the practical value.

In addition, crosstalk in FIG. 6 refers to the magnetic flux of the write signal of the read/write core 1 on the back side of the recording medium 11, which affects the read/write core 1a on the front side, causing noise and noise, as indicated by arrow A in FIG. It is the degree to which it appears. A conventional example in which the in-gap magnetic body 2 and the magnetic slider 10 are not configured has a crosstalk of about -84 dB to -80 dB depending on the write current. Next, in an example in which only the in-gap magnetic body 2 is formed without the magnetic slider 10, the above-mentioned crosstalk is also worsened due to the strengthening of the magnetic flux density of the in-gap magnetic body 2. However, when the magnetic slider 10 is provided, the crosstalk is dramatically improved, and the embodiment can eliminate crosstalk even more than the conventional example. For example, the crosstalk for a write current of 10 mA is -82 dB in the conventional example.
, -21 dB in the progress example.

In the example, it is -44 dB.

Note that, as shown in FIG. 7, the resolution with respect to the write current is the same in both the conventional example and the embodiment.

As described above, in this example, the magnetic material in the gap allows
Even recording media with high coercive force (H) and recording media with thick magnetic films can be written and read sufficiently, and by providing a magnetic slider, crosstalk that occurs when using double-sided floppy disks can be reduced. Figure 8 shows the second embodiment.
FIG. 9 is a front view of the read/write core and the erase core in a bulk type configuration, and is a front view of the third embodiment, and is a front view of the same configuration in a straddle head type. In either case of FIG. 8 or FIG. 9, an in-gap magnetic body may be provided on the side surface of the IJ-dry gap 3.

FIG. 10 shows a fourth embodiment, in which the shape of the magnetic slider 10 is enlarged to further reduce crosstalk. FIG. 11 shows a fifth embodiment of the magnetic slider 1.
0 shape is formed in the center of the magnetic head to facilitate assembly. FIGS. 12(a) and 12(b) show the sixth embodiment, showing the inside of the gear knob.

By attaching magnetic bodies 2a12b to both sides of the gear, it is possible to record even on recording media with high coercive force (He).

In these second to sixth embodiments, characteristics equivalent to or better than those of the first embodiment can be obtained.

Effects of the Invention As is clear from the above embodiments, the present invention uses a ferromagnetic material such as permalloy in the vicinity of the gap of a read/write core made of ferrite, and a part of the members constituting the slider has high magnetic permeability. Because the structure is attached with a magnetic material, it is possible to write and read data sufficiently even on recording media with high coercive force (He) and recording media with thick magnetic films.Moreover, even when using a double-sided floppy disk, the read/write core on one side can be used. This has the effect of reducing crosstalk in which magnetic flux becomes noise in the read/write core on the other side.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a double-sided magnetic head according to an embodiment of the present invention, FIG. 2 is a front view of a read/write core of this embodiment,
Fig. 3 is a bottom view of the read/write core of this embodiment, Fig. 4 is a front view showing an example of use of this embodiment, Figs. 5 to 7 are characteristic diagrams of this embodiment, and Figs. Figure 12 (a), (b)
are front views or bottom views of the second to sixth embodiments, respectively. DESCRIPTION OF SYMBOLS 1... Read/write core, 2... Gap vicinity core, 3... Read/write gap, 4... Erase gap, 5.5a, 5b... Erase core, 6... Center core, 7. ...Non-magnetic slider, 8...Read/write coil, 9...Erasing coil, 10...Magnetic slider, 11...Double-sided flexible disk. Name of agent: Patent attorney Toshio Nakao and 1 other person
4 Figure 5 Storage seven included curvature J Rokusho↑ Overwrite moshrege paddle sign/1 raw map 146 δ to Iz
Overwriting current [Practice 4] Figure 8 Figure 9x Figure 10 Decomposition party

Claims (1)

[Claims] It is equipped with a read/write core which is installed in a non-magnetic slider and whose main core is made of a first ferromagnetic material, and a core near the gap which is made of a second ferromagnetic material and which is provided on the side surface of the gap of this ferrite core. When placed on both sides via a magnetic recording medium, the magnetic flux generated from one read/write core propagates to the other read/write core, and is located within the nonmagnetic slider. A double-sided magnetic head with a magnetic slider attached to the .