JPS63213106A - Magnetic head - Google Patents

Abstract

PURPOSE:To obtain a high output by reducing the adverse effect of magnetic resistance and leakage at a part in the neighborhood of a magnetic gap and to improve reliability and workability, by forming the cutting plane of a winding groove on a magnetic gap side in curved structure, and selecting a tilt angle, etc., appropriately. CONSTITUTION:The cutting plane on the magnetic gap (g) side is constituted of first and second cutting planes 5a and 5b out of the cutting planes formed in the winding groove 5, and the tilt angle thetaH is set between 80-90 deg. and thetaW between 20-70 deg., and the length LH of the plane 5a is set at 0.3-1.5 times the depth DP of the magnetic gap. Therefore, it is possible to reduce the leakage keeping the core capacity of the part in the neighborhood of the gap (g), and to obtain the high output, and also, to obtain the high picture quality of a reproducing image, etc. Also, since the plane 5a is notched in a prescribed length LH in a direction almost orthogonal to a coupling plane 6, the depth DP can be measured with high accuracy in the range of the length LH even when an opaque part is generated on welding glass 8 in the neighborhood of the gap (g). Therefore, it is possible to perform the measuring work of the DP rapidly and with high accuracy. In such a way, the reliability and the workability can be improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic head installed in a magnetic recording/reproducing device such as a video tape recorder (VTR), and in particular, a winding that regulates the depth of a magnetic gap. Regarding the shape of the groove.

[Summary of the invention]

In the present invention, a pair of magnetic core halves are butted against each other to form a magnetic gap. In a magnetic head with a so-called bulk structure, among the cut surfaces on the magnetic gap side of the winding groove that regulates the depth of the magnetic gap, the cut surface on the magnetic gap side that regulates the depth is 80" to 90" with respect to the bonding surface. @ Incline the magnetic recording medium, and set the length of the magnetic recording medium in the running direction to 0 of the depth.
．． 3 to 1.5 times, and the inclination angle to the joint surface at a position further away from this is set to 20" to 70@, and by bending the cut surface on the magnetic gap side, the magnetic field in the vicinity of the magnetic gap is reduced. reduce various types of losses,
This is an attempt to realize high output of a magnetic head.

[Conventional technology]

Generally, a magnetic recording/reproducing device such as a tape recorder or a video tape recorder is equipped with a magnetic head as an electromagnetic transducer element that converts an electric signal into a magnetic signal for recording and reproduces the magnetic signal as an electric signal.

This type of magnetic head includes a pair of magnetic core halves (101), as shown in FIGS. 5(A) and 5(B), for example.
, (102) are butted together with a gap spacer (103) interposed therebetween and bonded with a fusing glass (105) to form a magnetic gap g. A winding groove (106) is formed in one magnetic core half (101) in order to wind the coil conductor (104), and the winding groove (106)
Among the cutting surfaces, the cutting surface on the side of the magnetic gear g (106a
) is configured to regulate the depth Dρ.

Conventionally, the angle α between the cutting surface (106a) and the joining surface (107) of the magnetic core half is
The angle is set to approximately 55° in consideration of the winding work etc. in 4).

[Problem that the invention seeks to solve]

Incidentally, in recent years, there has been a desire for higher quality of reproduced images, etc., and as a countermeasure to this, research aimed at improving head efficiency has been actively conducted in order to increase the output of magnetic heads.

However, in the conventional magnetic head, since the cut surface (106a) and the bonding surface (107) are close to each other, leakage magnetic flux called leakage (fifth
(Fig. CB)) marked with the symbol A] appears prominently. In particular, the leakage is large in the vicinity of the depth op, leading to a decrease in head efficiency.

Furthermore, when glass fusing the magnetic core halves (101) and (102), the fusing glass (105) reacts with the magnetic core material or the gap material, and as a result, the vicinity of the magnetic gap g is filled. The glass for fusing (105) becomes opaque. Therefore, it becomes difficult to measure the depth Op, which is important for head performance, with high precision.
This poses a problem in terms of head reliability or workability.

Therefore, the present invention has been proposed in view of the conventional situation, and has a structure in which the magnetic resistance near the magnetic gap is small, the negative effects of leakage are small, high output is possible, and the reliability and workability are excellent. The purpose of the present invention is to provide a magnetic head with improved characteristics.

(Means for solving the problems) In order to achieve the above-mentioned object, the magnetic head of the present invention has the following features:
In a magnetic head in which a pair of magnetic core halves are butted against each other to form a magnetic gap, and the depth of the magnetic gap is regulated by a winding groove provided on the joint surface of one of the magnetic core halves. , of the cut surface on the magnetic gap side of the S-line groove, the inclination angle of the portion near the magnetic gap that regulates the depth is 80'' to 90'' with respect to the bonding surface, and the length thereof in the running direction of the magnetic recording medium. is 0.3 to 1.5 times the depth, and the angle of inclination at a position further away than this is 2 to the joining surface.
0° to 70″, and is characterized in that the cut surface on the side of the magnetic gap is bent.

[Effect]

In the present invention, the cut surface on the magnetic gap side of the winding groove has a bent structure, the inclination angle of the cut surface that regulates the depth with respect to the bonding surface is 80'' to 90'', and the length in the running direction of the magnetic recording medium is the depth. Since the tlJI slope angle at a position further away from this is set to 0.3 to 1°5 times the angle of 20° to 70'', the distance between these cutting surfaces and the joint surface is secured.In particular, Since the distance between the cutting surface and the bonding surface can be secured in the vicinity of the magnetic gap, the decrease in Rad efficiency due to leakage is significantly reduced.
High output of the head is realized.

〔Example〕

Embodiments to which the present invention is applied will be described below with reference to the drawings.

The magnetic head of this example is shown in FIGS. 1(A) and 1(B).
), the magnetic core halves (1) and (2) are made of a soft magnetic material such as Mn-Zn ferrite,
The predetermined joint surfaces of these magnetic core halves (1) and (2) are butted together via a gap spacer (3) and fixed with a glass for fusing (8) to form a magnetic gap g involved in recording and reproduction. This is what happens. Further, the magnetic recording medium sliding surface (7) where the magnetic gap g is exposed is subjected to cylindrical polishing, so that good sliding contact with the magnetic recording medium can be obtained.

Of the magnetic core halves (1) and (2),
On the joint surface of one magnetic core half (1), the depth Dp of the magnetic gap g is regulated, and a coil conductor (4) is provided.
A winding groove (5) for winding the magnetic core is formed, and the joint surface (6) of the other magnetic core half (2) has a flat structure.

In this embodiment, the winding groove (5) has a first cutting surface (5a) located on the side of the magnetic gear g and regulating the depth Op;
a second cutting surface (5b) located further from the magnetic gap g than the first cutting surface (5a); a third cutting surface (5c) disposed opposite to the bonding surface (6); and a fourth cutting surface (5d) located on the gap side, and has a substantially trapezoidal appearance when viewed as a whole.

Here, among the cutting surfaces formed by the winding groove (5), the first cutting surface (5a) located on the magnetic gear g side
and the second cutting surface (5b) have inclination angles θ□ and θ1 with respect to the joint surface (6), respectively, set within the ranges of 80"≦08≦90"20°≦01≦70", and at the same time the above-mentioned First cutting surface (5a
) is the length of the magnetic recording medium in the running direction X, and I is 0.3X
It is set so that op≦L++≦1.5Xop.

That is, in this embodiment, the cut surface of the winding groove (5) on the magnetic gear g side is the first and second cut surfaces (5a),
(5b), and the first cutting surface (5a) is the joint surface (
6) a predetermined length and a tall notch in a direction substantially perpendicular to
A major feature is that the inclination angle θ8 of the second cutting surface (5b) is controlled at the same time. If the winding groove (5) is set as described above, these cutting surfaces (5a), (
5b) and the bonding surface (6), the glue cage in the vicinity of the magnetic gap is reduced and the head efficiency is improved. Even if the inclination angle θ1 of the second cutting surface (5b) is smaller than that of the conventional helad (α=55') and the leakage is about the same as the conventional one, in this case, the core volume near the magnetic gear g As the magnetic resistance increases and the magnetic resistance decreases, the head efficiency improves.

Here, the inclination angle θ of the first cutting surface (5a).

When the angle is less than 80°, the joint surface (6) and the cutting surface (5a) are close to each other, and the glue cage becomes noticeable in this part, making it difficult to improve the head efficiency. Conversely, the above inclination angle θ is 90@
If the depth OP is exceeded, the magnetic resistance at the bent portion (5^) formed by the first and second cutting surfaces increases as the depth OP decreases, causing a problem in terms of head performance. Therefore, it is preferable that the inclination angle θ8 is set within the range of 80'' to 90''. In addition, from the viewpoint of the accuracy of the depth Dlp, the workability of the winding groove, etc., it is more preferable that the above-mentioned inclination angle θa is 90''.

Furthermore, if the length -L9 of the first cut surface (5a) is less than 0.3 times the depth op, the effect of forming this cut surface (5a) will be weakened, and it will be bonded to the second cut surface (5b). As the surface (6) approaches, the cage becomes more noticeable and the induced magnetic flux decreases. Conversely, the above length is the depth [11]
If it exceeds 1.5 times, the core volume near the magnetic gear g decreases, resulting in a decrease in head efficiency. Therefore, the length □ is set to 0.3 to 1.5 times the depth Op.

Furthermore, the inclination angle θ of the second cutting surface (5b).

If the angle is less than 20", the cut surface (5b) and the joint surface (6) will face each other in close proximity, and the adverse effects of leakage will be significant. On the other hand, if it exceeds 70 degrees, the magnetic gear g
The volume of the core in the vicinity becomes smaller, making it difficult to improve head efficiency in either case. Therefore, the above inclination angle θ8
is set to 20” to 70@.

As described above, in this embodiment, among the cutting surfaces formed by the winding groove (5), the cutting surface on the side of the magnetic gear g is composed of the first and second cutting surfaces (5a) and (5b). , since the inclination angle θ1110- of these cutting surfaces (5a) and (5b) and the length LH of the first cutting surface (5a) are set within the above range, the core volume near the magnetic gear g is secured. Leakage can be reduced while maintaining the

Therefore, in the magnetic head of this embodiment, various magnetic losses such as leakage caused by the shape of the winding groove (5) can be minimized, and even higher output can be achieved. . As a result, a magnetic head suitable for improving the quality of reproduced images and the like can be provided.

In addition, since the first cut surface (5a) is cut out to a predetermined length LSI in a direction substantially perpendicular to the joint surface (6), an opaque portion is not generated in the fusion glass (8) near the magnetic gear g. However, the depth op can be measured accurately within the range of the length L described above. Therefore, the depth measurement work can be performed quickly and with high precision, and the reliability and workability of the head are greatly improved.

Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and can take various structures without departing from the spirit of the present invention. In addition, in Figure 2 (A) and Figure 2 (B), Figure 3 (A) and Figure 3 (B), Figure 4 (A) and Figure 4 (B) cited in the following explanation. In the magnetic head shown, the same members as those of the magnetic heads shown in FIGS. 1(A) and 1(B) are given the same reference numerals, and detailed explanation thereof will be omitted.

For example, as shown in FIG. 2(A) and FIG. 2(B),
Prepare two magnetic core halves (1) in which the winding grooves (5) in the previous embodiment are perforated, and
, (1) may be integrated into a magnetic head via a gap spacer (3). If winding grooves are provided in both magnetic core halves in this way, the opposing cutting surfaces (5b),
(5b) becomes larger, and the adverse effects of leakage can be further reduced.

In this case, the first cutting surfaces (5a) and (5a) do not necessarily need to be configured in a straight line, and the second
Even if the magnetic core halves are arranged with some deviation in the depth direction as shown in Figure (B), leakage can be improved if the winding grooves of the magnetic core halves that regulate the depth OP satisfy the above requirements.

Alternatively, as shown in FIGS. 3(A) and 3(B), the pair of magnetic core halves (1) and (2) are each made of an oxide magnetic material such as Mn-Zn ferrite. parts (la), (2a), and this magnetic core part (
It is composed of a composite magnetic material with ferromagnetic metal thin films (lb) and (2b) arranged on the contact surfaces of La) and (2a), and these ferromagnetic metal thin films (lb) and (2b) are butted against each other. The present invention is also applicable to a so-called composite type magnetic head whose surface is a magnetic gear g.

However, when the magnetic core halves (1) and (2) are made of a composite magnetic material as described above, the length of the first cutting surface (5a) in the medium running direction X is 'A magnetic metal thin film ( 11
) of the first and second cutting surfaces (5a).

(5b) to the bent part (5A).

Furthermore, as shown in FIGS. 4(A) and 4(B),
A composite magnetic head may be used in which the above-described composite magnetic material is used as the core material of the magnetic helad shown in FIGS. 2(A> and 2(B)).

As described above, if the present invention is applied to a magnetic head using a composite magnetic material for the magnetic core halves (1) and (2), various losses caused by the shape of the winding groove (5) can be reduced. Needless to say, a magnetic head is provided that can exhibit excellent recording and reproducing characteristics for high coercive force magnetic recording media such as metal tapes that are compatible with high-density recording.

In addition, in the above composite magnetic head, the structure of the magnetic recording medium sliding contact surface (7), that is, the ferromagnetic metal thin film (Ib)
, (2b) can take various conventionally known structures for this type of composite magnetic head.

Here, as the ferromagnetic metal thin film (lb), (2b), an alloy having a high saturation magnetic flux density and excellent soft magnetic properties is used. Specifically, an amorphous magnetic material such as an amorphous alloy is used. material or Fe-A (1-3i alloy).

Fe-Al-Ge alloy + Fe Ga S
i-based alloy.

Fe-Ga-Ge alloy + F a G e S
A crystalline magnetic material such as an i-based alloy is used.

The present inventors constructed each magnetic head described above by constructing a magnetic core half of Mn-Zn ferrite, having a track width of 25 μm, a depth op of 25 μm, and a gap length of 0.
．． The thickness was unified to 25 μm, and magnetic heads were manufactured under the same conditions. Note that in the magnetic heads shown in FIGS. 3(A) and 4(A), a ferromagnetic metal thin film (lb)
As (2b), a Fe-Ga-3i alloy thin film having a thickness of 3 μm was formed.

Next, the inductance, Q, and reproduction output of each of these magnetic heads at 5 MHz were measured.

In addition, in order to compare with the heads shown in FIGS. 1(A) and 2(A), the magnetic properties of the magnetic head shown in FIG. 5(A) were also measured, and the magnetic characteristics shown in FIGS. Figure 4 (A)
In order to compare with the head shown in FIG. 5A, a magnetic head having the same structure as that shown in FIG. 5(A) and having a magnetic core half made of the above-mentioned composite magnetic material was prepared, and the above-mentioned magnetic properties were also measured for this magnetic head. These measurement results are summarized in Table 1.

However, the measured values in the table are the average values obtained by producing 10 magnetic heads of each type.

Table 1 As is clear from Table 1, the magnetic head to which the present invention is applied has a reduction in leakage, which improves the playback output (
5MHz) was confirmed to be improved by about 0.6 to 1.0 dB. Also, the Q (5MHz) of the head is 3 to 1.
It was found that the improvement was 0%. Therefore, it has been found that by applying the present invention, a high output magnetic head can be realized and a high quality reproduced image can be obtained.

〔Effect of the invention〕

As is clear from the above description, in the present invention, among the cut surfaces of the winding groove, the cut surface on the magnetic gap side has a bent structure,
In addition to regulating the inclination angle of these cut surfaces with respect to the bonding surface, the length of the cut surface near the magnetic gap that regulates the depth in the running direction of the magnetic recording medium is set to 0.3 to 0.3 of the depth.
Since it is set to 1.5 times, the distance between the cut surface on the magnetic gap side and the bonding surface is ensured. As a result, leakage is reduced and various magnetic losses due to the shape of the winding grooves are reduced, so that high output of the head can be realized.

Furthermore, since the angle of inclination of the cutting surface that regulates the depth is approximately perpendicular to the joint surface, the depth can be measured quickly and with high precision, and the performance and workability of the head are improved at the same time.

Furthermore, the present invention can be easily realized using existing equipment without major changes to the conventional head manufacturing process, and its practical value can be said to be extremely high.

[Brief explanation of the drawing]

FIG. 1(A) is a cross-sectional view showing one embodiment of a magnetic head to which the present invention is applied, and FIG. 1(B) is an enlarged schematic diagram showing the vicinity of the magnetic gap of the magnetic head shown in FIG. 1(A). It is a diagram. FIG. 2(A) is a sectional view showing another embodiment of the present invention;
FIG. 2(B) is an enlarged schematic diagram showing the vicinity of the magnetic gap of the magnetic head shown in FIG. 2(A). FIG. 3(A) is a cross-sectional view showing still another embodiment of the present invention, and FIG. 3(B) is an enlarged schematic diagram showing the vicinity of the magnetic gap of the magnetic head shown in FIG. 3(A). . FIG. 4(A) is a sectional view showing still another embodiment of the present invention, and FIG. 4(B) is a schematic diagram showing an enlarged view of the vicinity of the magnetic gap of the magnetic head shown in FIG. 4(A). (A) is a cross-sectional view showing a conventional magnetic head, and Figure 5 (B) is Figure 5 (A).
FIG. 2 is an enlarged schematic diagram showing the vicinity of the magnetic gap of the magnetic head shown in FIG. 1.2... Magnetic core half 3... Gap spacer 5... Winding groove 5a... First cutting surface

Claims (1)

[Scope of Claims] A magnetic gap is formed by abutting a pair of magnetic core halves, and the depth of the magnetic gap is regulated by a winding groove provided on the joint surface of at least one of the magnetic core halves. In the magnetic head, of the cut surface of the winding groove on the magnetic gap side, a portion near the magnetic gap that regulates the depth has an inclination angle of 80° to 90° with respect to the bonding surface, and the magnetic recording medium travels. The length in the direction is set to 0.3 to 1.5 times the depth, and the inclination angle at a position further away from this is set to 20° to 70° with respect to the joint surface, and cutting on the magnetic gap side is performed. A magnetic head characterized by a curved surface.