JPS6350765B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an improvement in a magnetic head using a Sendust core.

Use high coercive force tape like metal tape
Attempts have been made to construct magnetic heads suitable for VTRs using alloy magnetic materials with high magnetic flux density, such as Sendust. When trying to manufacture this by butting two core halves together like in a conventional ferrite magnetic head, glass cannot be used as a bonding material because the wetting properties of the senduct are not as good as those of ferrite. . Therefore,
As shown in FIG. 1, the two core halves constituting the magnetic head core were joined together by silver solder which was arranged at approximately equal intervals between their opposing surfaces. Although it is preferable to arrange the junction points at approximately equal intervals in this way in order to maintain mechanical strength, the junction points close to the winding holes cause magnetic loss for short wavelength magnetic flux in the video region, and It was found that this caused the property to deteriorate.

SUMMARY OF THE INVENTION Therefore, the present invention aims to provide a magnetic head that reduces transmission loss of high-frequency magnetic flux while maintaining sufficient mechanical strength.

FIG. 2 shows a configuration diagram of an embodiment of the present invention. 1 and 2 are core halves made by Sendust for configuring the magnetic head core, and core half 1 is
is equipped with a winding hole 3. This core has a track width of 40 [μ], and it is possible to provide reinforcing members on both sides to improve the abrasion resistance against the tape, but this is not shown because it is outside the essence of the present invention. be. Further, the gap depth 4 of this core is 40 [μ], and the gap length, which is the spacing between the opposing core halves 1 and 2, is 0.6 [μ]. Spots 5 to 11 are gold solder for joining the core halves 1 and 2, and the distribution of these spots from the lower end of the winding hole 3 to the end 12 is sparse near the winding hole as shown in the figure. Further, they are arranged densely at the ends, and in the embodiment, the spot spacing ratio is set to 7:5:3:1:1 from the spot 6 side at the lower end of the winding hole.

FIG. 3 shows a comparison of the maximum reproduction output versus frequency characteristics of the magnetic head of the present invention and the conventional example shown in FIG. 1 in which the spot spacing ratio is constant. It can be seen that the characteristics of the present invention shown by the solid line are particularly superior in the high range compared to the conventional example shown by the dotted line. This is believed to be because the magnetic head of the present invention reduces magnetic loss due to spots near the winding holes. In addition, in order to investigate the joint strength of the head, we conducted a load-bearing test on the heads of the present invention and the conventional example, and found that the head of the present invention had greater durability, partly because the joint was made using gold solder. Ta. A comparison was also made with one using silver solder instead of gold solder, but there was no significant difference in that case.

In this way, in the present invention, the spots for joining the two core halves are arranged sparsely near the winding hole and densely at the end from the lower end of the winding hole to the end. , the magnetic loss in the high frequency range can be reduced, and as a result, the high frequency characteristics can be improved, as is clear from the characteristic comparison in FIG.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a conventional magnetic head, FIG. 2 is a block diagram of an embodiment of the magnetic head of the present invention, and FIG. 3 is a diagram of maximum reproduction output versus frequency characteristics. Explanation of main drawing numbers, 1, 2... Sendust core half, 3... Winding hole, 5-11... Spot.

Claims (1)

[Claims] 1. A magnetic head constructed by joining a Sendust core half with brazing material at multiple points between opposing surfaces of the core half so that the core half has a winding hole in the middle, and the spacing between the points is equal to the winding hole. 1. A magnetic head having a structure in which wires are arranged sparsely near the winding hole and densely arranged at the end from the hole to the end.