JPH03119506A - Magnetic head and production thereof - Google Patents

Abstract

PURPOSE:To prevent the proximate opposite edge parts of core chips from forming a pseudo gap by forming the opposite edge parts of the surfaces for sliding contact with media of the respective core chips disposed in proximity on a head base along a curved shape having a specific radius of curvature. CONSTITUTION:The opposite parts 9 of the surfaces 8 for sliding contact with media of two pieces of the core chips 2 mounted to one head base 1 in the proximate state are formed to the curved shape (m) having the radius of curvature regulated to >=1/5 the width (t) for sliding contact with media and <=1/2 the width (t) for sliding contact with media. The formation of the curved surface is difficult if the radius of curvature is smaller than 1/5 of the (t). The opposite edge parts 9 approximate to the state parallel with the gap (g) and there is the possibility that the pseudo gap is formed if the radius is larger than 1/2 the (t). The opposite edge parts 9 are formed along the curved surface by the simple means using a blade having the curve for cutting of the prescribed radius of curvature.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic head and a method for manufacturing the same, and more specifically, it is used in a double azimuth head, a VTR device having four heads, etc., in which two core chips are placed side by side and close to each other. The present invention relates to a magnetic head mounted and fixed on a head base in a state in which the magnetic head is mounted and fixed, and a method for manufacturing the same.

[Prior Art] A magnetic head used in a VTR device having a double azimuth head or four heads has a metal head base (1) with a tip (1a) attached to it, as shown in FIGS. 9 to 11.
Two core chips (2) (2) are arranged and placed and fixed in close proximity using an adhesive or the like. Although not shown, a wire is wound around the core chips (2) (2) by a predetermined number of turns, and each end is connected to the head base (1).
It is soldered to the printed wiring body above. Then, this magnetic head is assembled to a rotating drum of a VTR device using a mounting hole (3) formed in the base end of the head base (1).

Next, the core chips (2) (2) attached to the head base (1) will be specifically explained. These two core chips (2) (2) have the same structure except for the azimuth angle of the magnetic gap and the track width.
As shown in the figure, a pair of cores (4) (5) made of ferrite or other ferromagnetic material are integrally bonded with glass (6) (7) (7), and the medium sliding contact surface (8 ) is formed with a magnetic gap g having a predetermined azimuth angle and track width. The medium sliding contact surface (8) is processed into a single curved surface so that the magnetic tape, which is a magnetic recording medium, slides smoothly.
Furthermore, core chip (2) <2); b head base (1)
The edge portions (9) that face each other when attached to the frame are chamfered (10) to prevent chipping. In addition, (11) in the figure is a winding insertion hole.

The core chip (2) is manufactured through the steps shown in FIGS. 15 to 18. First, as shown in FIG. 15, a pair of rectangular parallelepiped core blocks (12) and (13) made of a ferromagnetic material such as ferrite are prepared. and,
As shown in FIG. 16, the core block (12) (
A plurality of track grooves (14), (15), etc. are cut leaving a predetermined track width at the edge portion of the inner surface of 13), and the winding is inserted into the center and bottom of each inner surface. A concave groove (16) serving as a hole and a V-groove (17) for bonding are cut, and the track grooves (14)...(15)... and V-groove (17) are molded with glass. Next, as shown in Fig. 17, both core blocks (12) and (13) are butted together with a non-magnetic film (not shown) such as 5i0□ serving as a gap spacer interposed therebetween and heated to join them together. do. Then, as shown in FIG. 18 □, the top end surfaces of the core blocks (12) and (13), which have been bonded and integrally coated, are curved and polished to form a media sliding surface (18). Apply C chamfering (19) along. Finally, the core blocks (12) and (13) are sliced at regular pitches at a predetermined azimuth angle to obtain core chips (2) shown in FIG.

[Problem to be solved by the invention]

By the way, in the magnetic head described above, since the two core chips (2) (2) are arranged side by side and close to each other on one head base (1), the core chips (2) (2)
) When writing and reading information with the magnetic tape running against the medium sliding contact surfaces (8) (8) of the core chips (2) (2), the opposing edges (9) ( 9
) is parallel to the magnetic gap g, resulting in a pseudo gap, causing a problem in that pseudo pulses are generated in the reproduction output of the magnetic head, making it difficult to obtain good output characteristics.

Therefore, the present invention has been proposed in view of the above problems, and its object is to provide a magnetic head and a magnetic head in which the adjacent opposing edge portions of the core chip do not form a pseudo gap by simple means (5). The object of the present invention is to provide a manufacturing method thereof.

[Means to solve the problem]

The technical means for achieving the above object of the present invention is to arrange two core chips in which a pair of cores made of ferromagnetic material are bonded into an integral film, and a magnetic gap is formed on the surface in contact with the medium, and the two core chips are placed side by side and close to each other. When mounted and fixed on the head base, the opposing edges of the medium sliding contact surfaces of each of the core chips are curved surfaces with a radius of curvature that is regulated to be 1/5 or more of the medium sliding contact width and less than A of the medium sliding contact width. This is a shaped magnetic head.

In addition, this method of manufacturing a magnetic head includes two parts on the head base.
When manufacturing core chips for magnetic heads that are placed and fixed in close proximity to each other, a pair of rectangular parallelepiped core blocks made of ferromagnetic material are butted together with a non-magnetic film serving as a gap spacer interposed therebetween. After the bonded integral film is applied, the edge portion along the longitudinal direction of the media sliding (6) contact surface of the core block coated with the bonded integral film is regulated to be at least the media sliding width of the core chip and less than the media sliding width A. The present invention is characterized in that each core chip is cut by a blade having a cutting surface with a radius of curvature.

[Effect]

In the magnetic head according to the present invention, since the opposing edge portions of the core chip have a curved surface shape with a radius of curvature of 1/5 or more of the medium sliding contact width and 2 or less of the medium sliding contact width, When writing and reading information to and from a magnetic recording medium that runs along the magnetic recording medium, a pseudo gap does not occur because the opposing edge portions of the core chip are non-parallel to the magnetic gap.

Further, the facing edge portions of the core chip can be formed into curved surfaces by a simple means using a blade having a cutting curved surface having the above-mentioned radius of curvature.

〔Example·〕

An embodiment of a magnetic head and a method for manufacturing the same according to the present invention will be described with reference to FIGS. 1 to 8. Note that the same or corresponding parts as in FIGS. 9 to 181 are given the same reference numerals, and redundant explanation will be omitted.

The feature of the present invention lies in the shape of the opposed edge portions (9) (9) of the medium sliding contact surfaces (8) (8) of the core chips (2) (2,) and the method of forming the same. Specifically, as shown in FIGS. 1 to 5, two core chips (2) (
2) of the media sliding contact surface (8) (8) facing edge portion (9) (
9), the media sliding contact width (1) is 1/5 or more of the media sliding contact width (1).
1) A curved surface shape (m
)(m).

Here, if the radius of curvature is smaller than 4 of the medium sliding width (1), it will be difficult to form a curved surface using the blade, which will be described later.・There is a risk that it will be necessary to add tape wrap, which will complicate the work. Also, if the curvature 1 radius is larger than the media-tangential width (1)%, the curvature will become too small and the conventional product ( Even when compared, the φ difference becomes small, and the opposing edge portions (a) (a) approach a state parallel to the magnetic gap, resulting in a pseudo gap.For the above reasons, the opposing edge portion < 9) (9) is converted into a curved surface shape (m) (m
), when the core chips (2) (2) are mounted on the head base (1) in close proximity to each other, the media sliding contact surfaces (8) (8) of the core chips (2) (2) When writing and reading information by running a magnetic tape, the opposing edge portion (9) of the core chip (2) (2)
(9) will not be non-parallel to the magnetic gap g and will not become a pseudo gap.

Next, the opposing edge part (9) of the core chip (2) (2)
The curved surface formation in (9) will be explained based on the method of manufacturing a magnetic head with reference to FIGS. 6 to 8.

First, a pair of core blocks (12,) (13) are coated with a non-magnetic film (not shown (9)) such as Sin, which serves as a gap substrate, as in the conventional manufacturing method, as shown in Figure 6. They are butted together to form an integral membrane. Then the seventh
As shown in the figure, the top end surface is polished into a curved surface and the media sliding contact surface (
18) and the medium sliding contact width (1) of the core chip (2)
A blade (21) having a cutting surface (20) with a radius of curvature that is regulated to be 1/5 or more of A and less than A of the media sliding width (1).
are arranged opposite to one edge portion (22) of the core blocks (12) (13) from diagonally above. From this state, move the blade (21) to the core block (12) (
13), cut the edge portion (22) with the cutting curved surface (20) of the blade (21) to form a curved surface shape (m) as shown in FIG.
The above-mentioned cutting process is performed while moving the core blocks (12) (13) in the longitudinal direction at a fixed pitch, that is, in units of core chips. After that, the above core block (12)
The core chip (2) shown in Fig. 3 is obtained by slicing (13) at a predetermined pitch at a predetermined azimuth angle.
get.

〔Effect of the invention〕

According to the present invention, the (10) opposing edge portion of the medium sliding contact surface of the core chip has a curved shape with a radius of curvature restricted to 1/5 or more of the medium sliding contact width and 2 or less of the medium sliding width. Therefore, when writing and reading information by running the magnetic recording medium against the sliding contact surface of the medium, the opposing edge portions become non-parallel to the magnetic gap, so there is no pseudo-gap, and reproduction is possible. Since no spurious pulses are generated in the output, good output characteristics can be obtained and a high quality and highly reliable magnetic head can be provided. In addition, the opposing edges of the core chip can be easily formed with a blade having a cutting curved surface with a radius of curvature that is regulated to be 1/5 or more of the medium sliding contact width and 2 or less of the medium sliding contact width. It is easy to manufacture by suitable means.

[Brief explanation of drawings]

FIG. 1 is an enlarged plan view of essential parts showing an embodiment of the magnetic head according to the present invention, FIG. 2 is a front view of FIG. 1, and FIGS. 3 and 1 are perspective views showing the core chip of FIG. 1. , FIG. 4, ・T is a front view of FIG. 3, and FIG. 5 is a plan view of FIG. 3, and FIGS. 9 is a perspective view showing a conventional example of a magnetic head, FIG. 10 is an enlarged front view of the main part of FIG. 9, and FIG. 11 is a plan view of FIG. 10, and FIG. 12 is a perspective view showing the core chip of FIG. 9;
The figure is a front view of Fig. 12, Fig. 14 is a plan view of Fig. 12,
FIGS. 15 to 18 are perspective views showing a core block for explaining a conventional method of manufacturing a magnetic head. (1) - Head base, (2) - Core chip, (4
) (5) - core, (8) - medium sliding contact surface, (9) one opposing edge, (g) - magnetic gap, (m) - curved surface shape, (t) - medium sliding contact width, (1, 2)
(li3) - core block, (18) -'-medium sliding surface, (20)--cutting curved surface, (21) blade - (22),'-edge portion. Patent applicant: Kansai NEC Co., Ltd.
Rihito Ebara, Shogo = 5
:

Claims (1)

[Claims] (1) A core chip with a pair of cores made of ferromagnetic material joined together and a magnetic gap formed on the surface where the medium slides.
When the core chips are mounted and fixed on a head base in close proximity to each other, the opposing edges of the medium sliding contact surfaces of each of the above core chips should be at least 1/5 of the medium sliding contact width and no more than 1/2 of the medium sliding contact width. A magnetic head characterized by having a curved surface shape with a radius of curvature regulated by . (2) When manufacturing core chips for magnetic heads that are placed and fixed on the head base in close proximity, a pair of rectangular parallelepiped core blocks made of ferromagnetic material is coated with a non-magnetic film that serves as a gap spacer. After they are butted together and joined together with glass, the edge part along the longitudinal direction of the media sliding contact surface of the joined and integrated core block has a media sliding contact width of 1/5 or more of the media sliding contact width of the core chip. 1/ of
1. A method of manufacturing a magnetic head, characterized in that each core chip is cut by a blade having a cutting surface with a radius of curvature regulated to be 2 or less.