JPS6020307A - Magnetic core - Google Patents

Abstract

PURPOSE:To reduce noise to an R/W core in an off-track state and eliminate noise to an erasing core by forming the 2nd magnetic body gap formation surface slanting to the 1st magnetic body gap formation surface. CONSTITUTION:The specularly polished gap formation surface 22P of the 2nd magnetic body 22 faces the specularly polished gap formation surface 21P of the 1st magnetic body 21 while a specific gap is left, and the medium contacting end part of the magnetic body 22 is made into a slanting surface 22P' by being beveled at an extremely small angle theta. Further, the magnetic body 22 is provided with the slanting surface 22P' having the extremely fine angle theta at the rear part in a medium scanning direction 7 for the erasing core. Consequently, noises to the R/W core are reduced in the off-track state, and noises to the tunnel erasing type erasing core are eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic core, and more particularly to the structure of a core of a magnetic head used in a magnetic storage device or the like.

As shown in FIG. 4, the conventional magnetic core has a gap portion in which a mirror-polished gap forming surface 11P of the magnetic body 11 and a mirror-polished gap forming surface 12P of the magnetic body 12 have a constant gap (air gap). They are formed with a structure in which they face each other with the glass 3t interposed therebetween. However, this magnetic core structure has a large drawback when used, for example, in the erase core of a tunnel erase type magnetic head of a floppy disk device.

In other words, in the tunnel erase type head, read/write (read/write) is used to record and reproduce information as shown in Figure 2.
几/W) A 几/W core 14 with a gap 14g, and adjacent to both sides of the 几/W core 14, an ise gap 15g, 15' for erasing both sides of the recorded track.
g'(r erase cores 15, 15' are slider 1
Therefore, in this type of magnetic head, track position deviation (
When an off-track occurs, the erase gap 15g, 15'g picks up the signal of the adjacent track and erases the signal from the adjacent track.
This had the disadvantage of causing noise and noise to the 4th.

SUMMARY OF THE INVENTION An object of the present invention is to provide an all-in-one core that eliminates the drawbacks of the sleepy core of conventional magnetic heads and reduces noise to the R/W core during off-track.

Another object of the present invention is to provide an erase core of a tunnel erase type one-shot head having characteristics characterized by noise to the core/W core during off-track.

According to the present invention, the gap-forming surface of the first amphoteric body and the second gap-forming surface do not come into contact with each other, thereby forming a gap in the core.

A core is obtained in which the gap forming surface of the second magnetic material is inclined with respect to the first gap forming surface, and the vicinity facing the medium is widened.

Further, according to the present invention, a core can be obtained in which the angle of inclination of the second gap forming surface is 3° or less with respect to the first gap forming surface.

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

FIG. 3 shows a gap portion of a magnetic core according to an embodiment of the present invention. In FIG. 3, this embodiment shows the first magnetic body 2
The mirror-polished gap-forming surface 21P of the first magnetic body 22 and the mirror-polished gap-forming surface 22P of the second magnetic body 22 face each other with a certain gap (gap) in between, but the gap between the magnetic bodies 22 The medium contacting end of the forming surface 22P is chamfered at a small angle θ to form a slope 22P'. The minute angle θ is desirably 3° or less in view of the voltage conversion characteristics of the magnetic core, and may be set to an optimum value as appropriate depending on the application.

FIG. 4 shows the erase gap when the five cores according to the present invention are applied to the erase core of a tunnel erase type magnetic head.

In this embodiment, a slope 22P' having a small angle θ is formed on the magnetic body 22 at the rear with respect to the medium running direction 27. The erase core of the tunnel erase magnetic head with this configuration does not reduce the output during erase.
Even if off-track occurs during information reproduction, the noise to the 几/W core can be reduced to zero. That is, the gap length g is set based on the following principle. Generally, the reproduction gap loss Lg for the gap length g is expressed by the following equation.

It can be seen that the gap loss Lg becomes infinite when the gap length g becomes an integral multiple of the recording wavelength λ.

Therefore, the gap length g of the erase core is equal to the recording wavelength λ
If it is set to an integer multiple of , even if the erase gap picks up adjacent track signals during off-track, the noise to the R/W core will be zero due to the effect of gap loss. Practically speaking, if s g>λ, a sufficient gap loss effect can be obtained. However, when the gap length g is increased, the resistance increases at once, and a sufficient write magnetic field is not generated. In one embodiment of the present invention, one method for solving this problem is to form a slope 2P'k on the gap forming surface 2P, thereby reducing the instantaneous resistance of the core drowsiness circuit. Further, in this embodiment, in the erase core of a tunnel erase type magnetic head of a floppy disk device, the sufficient effect as described above can be obtained when the gap length g is about 5 μm and θi '30' to 3 degrees.

As described above, the present invention forms an inclined surface of 3° or less at the media contacting end of one of the gap forming surfaces. It has the effect of reducing noise to zero.

[Brief explanation of drawings]

Figure 1 is an enlarged sectional view showing the gap part of the core, Figure 2
3 is a plan view showing the medium facing surface of a tunnel erase type magnetic head of a floppy disk device; FIG. 3 is an enlarged sectional view showing a gap portion of a drowsy core according to an embodiment of the present invention;
FIG. 4 is an enlarged sectional view showing the gap portion of the erase core according to the embodiment of the present invention. 21.22...R-isomer, 12P, 22P...
...gap forming surface, 22P'...slanted surface,
θ...Inclination angle. I graduated from 1st drawing twice

Claims (2)

[Claims] (1) In a magnetic core in which a gap is formed by a gap forming surface of a first magnetic body and a gap forming surface of a second magnetic body facing each other, the gap forming surface of the first magnetic body A magnetic core characterized in that a gap-forming surface of a second magnetic material is inclined with respect to the magnetic core, and the end portion facing the medium is widened. (2) The magnetic core according to claim 13, wherein the inclination angle of the second gap forming surface is 3° or less with respect to the first gap forming surface.