JPS6220608B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic head that improves crosstalk between magnetic head elements of multiple channels.

Conventionally, in a magnetic head constructed by attaching a plurality of magnetic head elements formed by winding coils around a head core to a core holder, magnetic flux leaks from the magnetic head element of one channel to the magnetic head element of the other channel. As a result, unnecessary crosstalk output voltages are induced in other channels, which significantly deteriorates channel separation when obtaining a three-dimensional sound field.
In order to avoid such crosstalk, a shield plate is interposed between the head cores (including the coil portions) of each of the channels.

FIG. 1 is a partially cutaway front view showing such a conventional magnetic head, and FIG. 2 is a schematic cross-sectional view showing a state in which the head core of the magnetic head is attached.
FIG. 3 is a schematic side view showing the arrangement relationship between the head core and the shield plate. In these figures, 1 is a shield case made of permalloy etc.
A core holder 2 made of a conductive material is housed inside this shield case 1.
Inside, head cores 3 and 4 and coils 7 and 8 wound through bobbins 5 and 6 are fitted and arranged in parallel. The tips of the head cores 3 and 4 protrude from the front surface of the core holder 2 so as to face the front surface of the shield case 1. Furthermore, terminal plates 9 and 10 for leading out the coils 7 and 8 are attached to the rear portions of the bobbins 5 and 6, making it possible to safely and easily connect an external connection lead wire (not shown) to the coils 7 and 8. It is now possible to do this. 1
1 is a shield plate made of a magnetic alloy such as permalloy that is interposed between the head cores 3 and 4 and between the coils 7 and 8, and is inserted into a slot 12 cut out in the front surface of the core holder 2 from the front or rear. , its tip extends even to the surface of the shield case 1.

However, in the magnetic head constructed as described above, the shield plate 11 only covers part of the opposing surfaces of the head cores 3 and 4 and the coils 7 and 8. In addition, the shield plate 11 is inserted into the slot 12 of the core holder 2, and
As shown in FIG. 1, gaps 13 and 14 of a certain extent (approximately 1 mm) are provided between the left and right sides and between the top and bottom surfaces of the shield plate 11, respectively. These gaps 13 and 14 are provided for reasons such as avoiding the troublesome work of obtaining the mounting dimensions of the shield plate 11 to the core holder 2 with high accuracy. Therefore, the magnetic flux leaking from one of the upper and lower head cores 3, 4, especially in the vicinity of the coils 7, 8, is guided to the other through the gaps 13, 14, and the magnetic flux of the two upper and lower head cores 3, 4 is guided to the other one through the gaps 13, 14, and the magnetic flux leaks from one of the upper and lower head cores 3, 4, especially in the vicinity of the coils 7, 8. Initial signals including signals are recorded on magnetic tape and reproduced, and measures to prevent crosstalk have not yet been taken sufficiently.

The present invention was devised in view of the problems that conventional magnetic heads have, and an object of the present invention is to effectively improve the above-mentioned crosstalk.

Embodiments of the present invention will be described below with reference to the drawings.

Figure 4 shows a shield case 1 made of a magnetic alloy such as permalloy, which constitutes a magnetic head according to the present invention.
5 is a side view showing the relationship between the core holder 16 made of conductive metal, and FIG. 5 is a perspective view of only the core holder 16.
It is formed so that the core holder 16 can be accommodated from the rear opening. This shield case 15
Magnetic head elements 19 and 20, which will be described later, are attached to the core holder 16 housed in the shield case 15, with the tips of the head cores 21 and 22 facing the long holes 17 and 18 formed in the front surface of the shield case 15.

By the way, the magnetic head elements 19 and 20 attached to the core holder 16 have head cores 21 and 22, as well as the conventional magnetic head described above.
Bobbins 23 and 24 are attached to these head cores 21 and 22.
It consists of a winding section in which coils 25 and 26 are wound through the bobbins 23 and 24, and recording or reproduction signals are transmitted and received through terminal plates 27 and 28 attached to the bobbins 23 and 24, respectively.

Furthermore, 29 is the front plate 3 of the core holder 16.
This is a slit for improving crosstalk that is provided in communication with a portion of the 0 and side plates 31 and 32. This slit 29 connects the two magnetic head elements 19,
20, as shown in FIG.
The magnetic head elements 19 and 26 are formed to have a depth that reaches the winding portion in which the magnetic head elements 19 and 26 are wound, and are provided to magnetically separate the magnetic head elements 19 and 20.

As mentioned above, slit 2 for crosstalk improvement
In the magnetic head according to the present invention provided with 9, the measurement circuit shown in FIG.
When the crosstalk between the two magnetic head elements 19 and 20 was measured, the results shown in FIG. 7 were obtained. That is, in FIG. 6, a signal source 33 of a predetermined frequency and a voltmeter 34 are connected to both sides of the coil 25 of one magnetic head element 19, and a voltmeter 35 is connected to the other magnetic head element 20. , when a signal voltage is supplied from the signal source 33,
As shown in FIG. 7, the crosstalk is improved by approximately 6 dB to 13 dB at 100 Hz to 4 KHz compared to the magnetic head without the slit 29 described above. Examining the cause of this, we found that the magnetic field emitted from one magnetic head element 19 is caused by the conductive core holder 1 made of metal
A portion of the magnetic head element 20 is consumed as eddy current loss on the surface of the magnetic head element 6, but the effect of the generation of this eddy current loss on the other magnetic head element 20 appears as is, and the effect is large when the slit 29 is not provided. On the other hand, when the slit 29 is provided, the eddy current loss flow path is narrowed by the slit 29, and the eddy current loss near the other magnetic head element 20 is limited or attenuated. This is considered to be because the occurrence of crosstalk between the magnetic head elements 19 and 20 is improved.

As described above, the present invention provides a magnetic head in which a plurality of magnetic head elements are attached in parallel to a metal core holder, in which each of the magnetic head elements is magnetically positioned between the magnetic head elements of the core holder. As is clear from FIG. 7, the slit is provided with a depth extending from the front side of the core holder to the winding portion of the magnetic head element. It was possible to improve crosstalk between each magnetic head element by 6dB to 13dB. This crosstalk improvement is
This was a significant improvement compared to the conventional one with a shield plate, which could only achieve an improvement of about 3dB to 5dB.

Further, the present invention provides for improving crosstalk.
Since only the slits are provided, there is no increase in the number of parts, and furthermore, the number of assembly steps can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing a conventional magnetic head, FIG. 2 is a sectional plan view thereof, and FIG. 3 is a schematic side view. FIG. 4 is a side view showing the relationship between the shield case and the core holder of the magnetic head according to the present invention, FIG. 5 is a perspective view of the core holder, and FIG.
The figure is a crosstalk measurement circuit diagram, and FIG. 7 is a graph showing comparative values of crosstalk improvement. 15... Shield case, 16... Core holder, 19, 20... Magnetic head element, 25, 26
...Coil, 29...Slit for improving crosstalk.

Claims (1)

[Scope of Claims] 1. In a magnetic head in which a plurality of magnetic head elements are attached in parallel to a metal core holder, each of the magnetic head elements is magnetically positioned between the upper magnetic head elements of the core holder. A magnetic head characterized in that a slit for improving crosstalk is provided with a depth extending from the front side of the core holder to the winding portion of the magnetic head element.