JPH0124734Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a magnetic head whose core is mainly made of a metallic magnetic material, which is used in VTRs and the like.

(b) Prior art In order to record and reproduce signals containing high-frequency signal components such as television signals using a recording medium with high coercive force characteristics, a magnetic head with a core made of a magnetic metal material with a high saturation magnetic flux density is required. Are suitable. This metal magnetic material has a lower specific resistance than ferrite material, so the core thickness cannot be increased, and the wear resistance is also not high, so reinforcement is applied from both sides of the core body, which has a total thickness equivalent to the track width. The mechanical properties are improved by attaching the tape to the tape to reduce the unit load on the tape contact surface. FIG. 1 shows a typical example of this type of magnetic head, in which 1 is the main core, 2 is a reinforcing body, and 3 is a coil. Here, the coil window 1a of the core main body 1 is formed small in order to reduce the magnetic path length, while the reinforcing body 2
The coil window 2a is made large in consideration of the ease of coil winding work. Therefore, the coil window of this magnetic head is constructed such that the side surface of the core body 1 protrudes beyond the side surface of the reinforcing body 2. As is clear from the partially enlarged sectional view of FIG. 2, there was a drawback that the corner 1b of the core body 1 bit into the wound coil 3, breaking the insulation coating of the coil and causing a short circuit. This drawback is also seen when the core body 1 protrudes outward from the reinforcing body 2 on the outer side of the magnetic head. Therefore, in order to prevent this, an insulating resin part 4 is provided on this protruding part 1c of the core main body 1 as shown in FIG. 3, and a coil 3 is wound on this insulating resin part, as shown in FIG. Although this is effective, another drawback is that a space 5 is created between the coil and the main core by the thickness of the resin portion 4, which reduces the regeneration efficiency.

(c) Purpose of the invention The present invention was developed in view of the above points, and aims to provide a magnetic head that prevents short-circuit accidents between the core body and the coil, and also prevents a decrease in regeneration efficiency.

(d) Structure of the invention The invention includes a magnetic head core having a core body made of a metal magnetic material and a pair of reinforcing cores sandwiching the core body, and a coil wound around the winding hole of the magnetic head core. The magnetic head is characterized in that the main body of the core is placed in a retracted position in the area where the coil is wound so that it does not come into contact with the coil.

(E) Embodiment FIG. 4 is a partially cutaway perspective view of an embodiment of the magnetic head of the present invention, FIG. 5 is a partial sectional view of the coil winding area, and FIG. 6 is a comparative characteristic of regeneration efficiency. It is a diagram.

The magnetic head of this embodiment is a magnetic head core comprising a core main body 10 made of sendust and a set of reinforcing bodies 20 for sandwiching this core main body.
CO and a coil 30 wound around the winding hole H of the magnetic head core. This magnetic head has a tape contacting surface S rounded for alignment with the tape, and has a coil winding area D around the winding hole H.

The total thickness T of the core main body 10 corresponds to the track width.
The core halves 11 and 12, each having a diameter of about 20 μm, are butted against each other, and a front gap F is formed above a notch 13 that serves as a coil window. A spacer (not shown) made of a non-magnetic material (SiO ₂ ) is provided within this front gap.

The reinforcing bodies 20, 20 are made of a non-magnetic material (glass) so as to back the front gear F of the core main body 10.
a first portion 21 made of a magnetic material, a second portion 22 made of a magnetic material (ferrite) that acts to increase the cross-sectional area of the magnetic path and improve reproduction efficiency, and a through hole arranged to correspond to the notch 13. A hole 23 is provided.

In the coil winding area D, each core half 11,1
As shown in an exaggerated manner in FIG. 5, the outer surface of the reinforcing body 20 is set back a distance K from the outer surface of the reinforcing body 20. Therefore, when the coil 30 is wound around the magnetic leg using the coil window, the core body 10 is placed apart from the coil 30 as shown in FIG. 5, resulting in a short circuit accident between the core body and the coil. can be prevented. The outer surface of the core main body 10 is
The core main body 1 may be placed on the same plane or slightly protruding from the reinforcing body 20 instead of being placed inside the reinforcing body 20 as shown in the figure.
0 and the coil 30 can be prevented from contacting each other. This is because the coil portion stretched between the corners 24 of the reinforcing body 20 is not disposed in close contact with the outer surface of the reinforcing body 20.

FIG. 6 compares the reproduction output characteristics of the magnetic head of the present invention and a conventional magnetic head equipped with the insulating resin portion shown in FIG. This shows the reproduction output of the magnetic head of the present invention as a percentage (characteristic ). As shown in the figure, the magnetic head of the present invention exhibits good reproduction output characteristics in the entire frequency range.

(f) Effects of the invention In this invention, the main body of the core in the coil winding area is placed in a retracted position where it does not come into contact with the coil that is wound using the coil window of the magnetic head. This has the effect of preventing short circuit accidents. Further, it is possible to prevent the playback output characteristics from being significantly degraded, unlike in the case where an insulating resin portion is provided to prevent this short circuit.

[Brief explanation of the drawing]

FIG. 1 is a front view of a conventional magnetic head, and FIG. 2 is a partially enlarged sectional view of this magnetic head. FIG. 3 is a partial sectional view of another conventional example. FIG. 4 is a partially cutaway perspective view of the magnetic head of the present invention, and FIG. 5 is a partial cross-sectional view of the coil winding area. FIG. 6 is a frequency characteristic diagram of the reproduced output. Explanation of main drawing numbers, 10... Core main body, 20, 2
0...Reinforcement body, 30...Coil, D...Coil winding area.

Claims (1)

[Scope of utility model registration request] A core main body made of a metal magnetic material having a front gear and a coil window defining the lower end of the front gear is provided with a pair of reinforcing bodies each having a through hole communicating with the coil window so as to sandwich the core main body. In a magnetic head comprising a magnetic head core and a coil mounted in a winding hole of the magnetic head core, the core main body is located at a retracted position in a winding area of the coil where it does not come into contact with the coil. A magnetic head characterized by: