JPH01122004A - Magnetic head device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic head device in which an erasing head and a recording/reproducing head are connected, and more particularly to improving crosstalk from the erasing head to the recording/reproducing head.

[Conventional technology]

With the increasing density of magnetic recording, magnetic heads using high saturation magnetic flux density materials are being developed as heads for magnetic disks (Japanese Unexamined Patent Publication No. 39907/1983). Furthermore, in order to increase the recording capacity, it is necessary to reduce the gap between the recording/reproducing head and the erasing head, and an improvement plan as shown in FIG. 3 has been proposed. That is, as is clear from the figure, the first core half 36 of the erasing head 22 is made up of only the first magnetic thin film 44 (Japanese Unexamined Patent Publication No. 63911/1983). However, as the gap distance decreases, the erase magnetic field increases due to an increase in the coercive force of the medium, and the gap length of the recording/reproducing head becomes narrower, crosstalk between the erasing head and the recording/reproducing head becomes a problem.

[Problem that the invention seeks to solve]

An object of the present invention is to solve the drawback of crosstalk that the above-mentioned magnetic head device has.

[Means to solve the problem]

In order to achieve the above object, the present invention increases the magnetic permeability in the direct current and low frequency bands by making the magnetic path of the erasing head the axis of easy magnetization, thereby improving the erasing ability and making it easier to read signals during playback. In order to minimize the amount, the domain wall movement should not follow in the signal band.

〔Example〕

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

FIG. 1 is a plan view of a composite magnetic head, which is the premise of the present invention.
FIG. 2 is a sectional view taken along line E-II in FIG. 1. This composite magnetic head is used in a magnetic disk recording/reproducing device, and includes a recording/reproducing head 21, an erasing head 22, and a non-magnetic material 23 for preventing magnetic influence between the two magnetic heads.
It is mainly composed of. These integrated bodies are attached to a head holder (not shown) so that the recording/reproducing head 21 is disposed on the upstream side in the running direction of the magnetic recording medium (N-air disk), and the erasing head 22 is disposed on the downstream side thereof. .

The recording/reproducing head 21 is mainly composed of a first core half 24, a second core half 25 opposing it, and an excitation coil 27 wound in a coil groove 26 provided in the first core half 24. There is. A reinforcing layer 28 is made of a non-magnetic material such as glass, and is provided near the joint between the first core half 24 and the second core half 25.

The first core half 24 has a first core base 3 having a chevron-shaped protrusion 29 approximately at the center of the side surface facing the magnetic gap 35.
0 and a first magnetic thin film 31 adhered to the side surface.

The first core base 30 is made of a ferrite having high magnetic permeability, such as manganese-zinc ferrite or nickel-zinc ferrite. On the other hand, for the first magnetic thin film 31, a crystalline alloy or an amorphous alloy having high saturation magnetic flux density and high magnetic permeability is used. Examples of such crystalline alloys include iron-aluminum-silicon alloys, iron-silicon alloys, and iron-nickel alloys. The amorphous alloy includes one or more elements selected from the group of iron, nickel, and cobalt, and phosphorus.

An alloy consisting of one or more elements selected from the group of carbon, boron, and silicon, or an alloy consisting of this as the main component,
Alloys with added elements such as aluminum, germanium, beryllium, tin, molybdenum, in, duium, tungsten, titanium, manganese, chromium, zirconium, hafnium, niobium, etc., or alloys containing cobalt or zirconium as the main components and containing the above-mentioned additive elements. There are also metal alloys.

Similarly to the first core half 24, the second core half 25 also has a chevron-shaped protrusion 3 approximately in the center of the side surface facing the magnetic gap 35.
a second core base 33 made of ferrite with high magnetic permeability and a second magnetic thin film 34 made of a magnetic metal material with high saturation magnetic flux density and high magnetic permeability adhered to the side surface of the second core base 33;
It is composed of. As shown in FIG. 1, the protrusion 29 and the first magnetic thin film 31 on the first core half 24 side, and the protrusion 32 and the second magnetic thin film 3 on the second core half 25
4, the shape in the vicinity of the joint portion is approximately symmetrical with respect to the magnetic gap 35. This magnetic gap 35 is
It has a length of about 20 to 140 μm.

On the other hand, the erasing head 22 mainly consists of a first core half 36 , a second core half 37 facing the first core half 36 , and an excitation coil 39 wound around a coil groove 38 provided in the second core half 37 . It is configured. A reinforcing layer 40 is made of a non-magnetic material such as glass, and is provided near the joint between the first core half 36 and the second core half 37.

The first core half-housing 36 includes a first core base 43 made of ferrite with high magnetic permeability and having two chevron-shaped protrusions 42 at a predetermined interval on the side facing the magnetic gap 41, and a first core base 43 made of ferrite with high magnetic permeability, and a first core base 43 made of ferrite having a high magnetic permeability. The first magnetic thin film 44 is made of a metallic magnetic material having a high saturation magnetic flux density and high magnetic permeability.

Like the first core half 36, the second core half 37 is also a second core made of high magnetic permeability ferrite and has two chevron-shaped protrusions 42 at a predetermined interval on the side facing the magnetic gap 41. It is composed of a base body 46 and a second magnetic thin film 47 made of a metallic magnetic material having high saturation magnetic flux density and high magnetic permeability and adhered to the side surfaces of the base body 46. Therefore, as shown in FIG. 1, the protrusions 42 and the first magnetic thin film 44 of the 36 examples of the first core half, and the protrusions 45 on the second core half 37 side.
In addition, the shape of the second magnetic thin film 47 in the vicinity of the joint portion is substantially symmetrical with respect to the magnetic gap 35 .

Magnetic gap 35 of recording/reproducing head 21 and erasing head 2
The two magnetic gaps 41 of No. 2 have a positional relationship as shown in FIG. is partially erased and the track width is regulated.

In the magnetic head device configured as described above, in order to control the magnetic anisotropy of the high saturation magnetic flux density material of the erasing head 22, a magnetic field is applied in the depth direction during magnetic film formation and glass filling. .

FIGS. 4 and 5 show the characteristics of a magnetic head device manufactured with anisotropy in an arbitrary direction.

Kukostalk is the ratio of the signal from the erase head during playback to the signal from the recording/playback head, and asymmetry is the so-called crosstalk during recording, where a bias is added to the recording magnetic field by DC magnetic flux on the erase head side during recording. This represents the left-right asymmetry of the reproduced signal that occurs due to storage. Note that the erase current was determined for each head as a current for erasing a certain amount of the reference signal. As you can see from the figure, 45
It exhibits good characteristics below the temperature.

〔Effect of the invention〕

As described above, in the present invention, by arranging the axis of easy magnetization of the erasing head in the direction of the gap forming surface, it is possible to improve the erasing efficiency and reduce crosstalk.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a composite magnetic head, which is the premise of the present invention.
Figure 2 is a cross-sectional view taken along line E-I in Figure 1, Figure 3 is a plan view of a conventional composite magnetic head, and Figures 4 and 5 are magnetic heads fabricated with anisotropy in any direction. FIG. 21... Recording/reproducing head, 22... Erasing head. Fig. 1 22: 3 Portion Fig. 2 Fig. 3 Cause Fig. 4 Gear ff 2 Face force

Claims (1)

[Claims] In a magnetic head device in which a recording/reproducing magnetic head and an erasing head are connected and the erasing head is used to erase a magnetic medium with direct current, the axis of easy magnetization of the magnetic material forming the erasing head is set at an angle of 45 degrees or less with respect to the gap forming surface. A magnetic head device characterized by: