JPH08124110A - Magnetic head - Google Patents

Abstract

PURPOSE: To drastically decrease crosstalks while maintaining a high sensitivity. CONSTITUTION: Respective sliding parts 21, 22 are formed at nearly the same width as a track width T in a direction orthogonal with a magnetic gap (g) symmetrically with the magnetic gap (g) as a center. This magnetic head is constituted by forming a magnetic recording medium-sliding surface in such a manner that the ratio H/T of the length H of these sliding parts 21, 22 and the track width T satisfies 0<H/T<=1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head mounted on, for example, a VTR (video tape recorder), and more particularly to the shape of a sliding surface of a magnetic recording medium.

[0002]

2. Description of the Related Art Usually, a magnetic head provided in a VTR is provided as a rotary magnetic head device by being provided on a peripheral surface of a rotary drum, and a magnetic tape of a magnetic recording medium is attached to a video tape which is a magnetic recording medium. The moving surface slides to record and reproduce video and audio.

As an example of the above-mentioned magnetic head, as shown in FIG. 6, a pair of magnetic core halves 101 and 102 made of a magnetic material such as ferrite are butted against each other via a gap material and integrated to form a magnetic gap g. There is a head chip 103 having This magnetic head has a winding groove 111 and a guide groove 112 for positioning the winding material, and the winding material is wound around the winding groove 111 and the guide groove 112 a predetermined number of times to form a coil.

Here, the head chip 103 has an abutting width processing for ensuring an abutting width with respect to the magnetic recording medium to form a sliding surface a of the magnetic recording medium, and the magnetic gap g is a track. The width regulation groove 113 forms a predetermined track width T. That is, the head chip 103 has the track width regulating groove 114 provided on the abutting surface of each of the magnetic core halves 101 and 102.
The surfaces having the track width T are abutted with each other via a gap material, and are joined and integrated by the fused glass 104 to form a magnetic gap g.

In the magnetic head, the head chip 103 is adhered and fixed to a predetermined head substrate (head base), and each terminal of the coil is electrically connected to a predetermined position of the head substrate. Further, the magnetic head is mounted on the peripheral surface of the rotary drum to form a rotary magnetic head device.

[0006]

As described above, on the magnetic recording medium sliding surface a of the head chip 103, in the vicinity of the magnetic gap g, the track width regulating groove 114 causes the contact width W of the head chip 103 to be smaller than the contact width W of the head chip 103. The shape is gradually narrowed toward the magnetic gap g having the track width T. In this case, the sensitivity is satisfactory, and high-sensitivity recording / playback is possible. However, in the case where the magnetic recording medium sliding surface a is formed as in the above structure, the adjacent crosstalk between adjacent tracks is large, which is regarded as a very practical problem.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a magnetic head capable of realizing a significant reduction in crosstalk while maintaining high sensitivity. To provide.

[0008]

The object of the present invention is a magnetic head in which a pair of magnetic core halves are fused together via a gap material to form a magnetic gap.

In the magnetic head of the present invention, the magnetic recording medium sliding surface of each magnetic core half body is formed symmetrically with respect to the magnetic gap in the direction orthogonal to the magnetic gap and to have a width substantially equal to the track width T. Length of each sliding part H
And the ratio H / T to the track width T satisfies 0 <H / T ≦ 1 and more preferably 0.7 ≦ H / T ≦ 1.

When the value of the ratio H / T is 0,
The adjacent crosstalk amount becomes large and practically inconvenient. When it becomes larger than 1, the output reduction amount exceeds 0.5 dB, which is also inconvenient.

The present invention can also be applied to the magnetic head described above in which the magnetic gap has a predetermined azimuth angle in order to improve the recording density.

[0012]

In the magnetic head according to the present invention, the ratio H / T between the length H of each sliding portion and the track width T is 0 <H / T≤1 (preferably 0.7≤H / T≤ The sliding surface of the magnetic recording medium is formed so as to satisfy 1). Here, the smaller the length H of the sliding portion is, the higher the sensitivity becomes, and the maximum sensitivity is obtained when H = 0. On the other hand, the larger the length H is, the larger the adjacent crosstalk between the adjacent tracks of the magnetic recording medium becomes. , H = 0, the maximum. On the other hand, as the length H increases, the sensitivity decreases, but the adjacent crosstalk decreases. Therefore, in the present invention, since the above ratio H / T satisfies the above equation, the sensitivity and the adjacent crosstalk are balanced, and the high sensitivity is maintained to such an extent that there is practically no problem, while the adjacent crosstalk is suppressed. It will be sufficiently reduced.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the magnetic head according to the present invention will be described in detail below with reference to the drawings.

The magnetic head manufactured in this embodiment is one in which a pair of magnetic core halves are fused together via a gap material to form a magnetic gap. This magnetic head is mainly provided on the VTR, and is provided on the peripheral surface of the rotary drum to form a rotary magnetic head device.
A video tape, which is a magnetic recording medium, slides on the sliding surface of the magnetic recording medium of the magnetic head to record and reproduce video and audio.

As shown in FIG. 1, the magnetic head comprises a pair of magnetic core halves 1 made of a magnetic material such as ferrite.
In some cases, the head chips 3 having a magnetic gap g are formed by abutting and integrating the two via a gap material. This magnetic head has a winding groove 11 and a guide groove 12 for positioning the winding material, and the winding material is wound around the winding groove 11 and the guide groove 12 a predetermined number of times to form a coil.

Here, the head chip 3 has an abutting width process for securing an abutting width W against a magnetic recording medium such as a video tape, and a magnetic recording medium sliding surface a is formed on the upper portion of the head chip 3. The magnetic gap g is the track width regulation groove 1
3 has a predetermined track width T. That is, in the head chip 3, the surfaces having the track width T are abutted through the gap material by the track width regulating grooves 13 provided on the abutting surfaces of the magnetic core halves 1 and 2, and the fused glass is formed. 4, the magnetic gap g is formed by being joined and integrated by 4.

In particular, on the sliding surface a of the magnetic recording medium, as shown in FIG. 2, the track width T is substantially equal to the track width T in a direction symmetrical to the magnetic gap g with respect to the magnetic gap g. The sliding portions 21 and 22 are formed, and the ratio H / T between the length H of these sliding portions 21 and 22 and the track width T is 0 <H / T ≦ 1 (1 ), The sliding surface a of the magnetic recording medium is formed.

In the magnetic head, the head chip 3 is adhesively fixed to a predetermined head substrate (head base), and each terminal of the coil is electrically connected to a predetermined position on the head substrate. Further, the magnetic head is mounted on the peripheral surface of the rotary drum to form a rotary magnetic head device.

Here, one experimental example will be described.
In this experiment, in the magnetic head of the above-mentioned embodiment, the length H of the sliding portions 21 and 22, here, the ratio H / T between the length H and the track width T of the magnetic gap g is different. The reproduction output and the adjacent crosstalk were investigated by using a magnetic head of a kind. That is, in this experiment, as shown in FIG. 3, the ratio H / T was 4 from the magnetic head having the length of 0 (the structure of the conventional magnetic head).
Several types of magnetic heads were used as samples.

In the above experiment, the track width T of the magnetic recording medium sliding surface a of each magnetic head was 20 μm,
The gap length was 0.2 μm, and the width of the track width regulating groove 13 in the direction parallel to the magnetic gap g was 20 μm. Further, the reproduction wavelength was set to 3 μm, which most affects adjacent crosstalk.

The respective measurement results are shown in FIGS. 4 and 5. Regarding the reproduction output, as shown in FIG.
It decreases almost monotonically as the value of / T (length H above) increases. Practically, it is considered that the output decrease to about 0.5 dB compared with the maximum output value when H / T = 0 is within the allowable range. Therefore, in this case, it is understood that the value of the ratio H / T should be 1 or less.

Adjacent crosstalk is practically H /
Compared to the case where the adjacent crosstalk at T = 0 is maximum −
It is ideal if it is 35 dB or less, but as shown by the envelope (shown by the broken line) in FIG. 5, this condition can be satisfied if the value of the ratio H / T is approximately 0.7 or more. I understand.

In the magnetic head, as described above,
The smaller the length H of each of the sliding portions 21 and 22, the higher the sensitivity becomes, and the maximum sensitivity is obtained when H = 0. On the other hand, the larger the length H is, the larger the distance between adjacent tracks of the video tape as a magnetic recording medium becomes. Adjacent crosstalk is large, and becomes maximum when H = 0. On the other hand, as the length H increases, the sensitivity decreases, but the adjacent crosstalk decreases.

Therefore, in this embodiment, the ratio H /
The value of T is 0 <H / T ≦ 1, preferably 0.7 ≦ H / T
In order to satisfy ≦ 1, the sensitivity and the adjacent crosstalk are balanced, and the adjacent crosstalk is sufficiently reduced while maintaining the high sensitivity to the extent that practically no problem occurs.

The present invention is not limited to the above embodiment, but can be applied to, for example, an azimuth recording type magnetic head having a magnetic gap g having a predetermined azimuth angle, and a pair of magnetic core halves. It can also be applied to a so-called metal-in-gap (MIG) type magnetic head in which a required metal thin film is formed on the abutting surface of the body and these magnetic core halves are butted.

[0026]

As is apparent from the above description, according to the magnetic head of the present invention, it is possible to significantly reduce crosstalk while maintaining high sensitivity.

[Brief description of drawings]

FIG. 1 is a perspective view schematically showing a head chip of a magnetic head of this embodiment.

FIG. 2 is a plan view schematically showing a sliding surface of a magnetic recording medium of the magnetic head.

FIG. 3 is a plan view schematically showing a sliding surface of a magnetic recording medium when the sliding portion has a length of zero.

FIG. 4 is a ratio H / T of the length H of the sliding portion and the track width T.
FIG. 3 is a characteristic diagram showing the relationship between the output and the reproduction output (relative value).

[FIG. 5] Ratio H / T of the length H of the sliding portion and the track width T
FIG. 6 is a characteristic diagram showing a relationship between (and a sliding portion length H) and an adjacent crosstalk value (relative value).

FIG. 6 is a perspective view schematically showing a head chip of a conventional magnetic head.

[Explanation of symbols]

 1, 2 Magnetic core half body 3 Head chip 13 Track width regulation groove 21, 22 Sliding part g Magnetic gap T Track width H Length of each sliding part

Claims (3)

[Claims] 1. A pair of magnetic core halves are fused together via a gap material to form a magnetic gap, and the magnetic recording medium sliding surfaces of the magnetic core halves are symmetrical about the magnetic gap. The ratio H / T of the length H of each sliding portion formed to have a width substantially equal to the track width T in the direction orthogonal to the magnetic gap and the track width T is 0 <H / T ≦ 1. A magnetic head characterized by satisfying: 2. The magnetic head according to claim 1, wherein the ratio H / T between the length H of each sliding portion and the track width T satisfies 0.7 ≦ H / T ≦ 1. 3. The magnetic head according to claim 1, wherein the magnetic gap has a predetermined azimuth angle.