JPS5952423A - Magnetic head - Google Patents

Abstract

PURPOSE:To measure gap depth and to remove variance factors of head characteristics by employing a light-transmissive prismatic member as at least of auxiliary members arranged on both sides of a magnetic gap in a track direction. CONSTITUTION:In a figure, 7 is a couple of magnetic cores made of ferrite, i.e. oxide magnetic material with the magnetic gap 8 atop and said couple of magnetic cores 7 are welded together with glass 9. The prismatic auxiliary members 11 which are made of transparent glass and have slanting surfaces 10 are arranged adjacently on both sides of the magnetic cores 7 in the track direction as usual so that the magnetic gap 8 is sandwiched, and fixed to the magnetic cores 7 with transparent adhesive. Further, the magnetic cores 7 are wound with a coil 12 to constitute a magnetic head. When the magnetic cores 7 are worked, size L5 is found previously on the basis of a surface E and they are finished to size L6 obtained by adding specific gap depth D.

Description

[Detailed description of the invention] Industrial application field.

The present invention relates to a magnetic head used for magnetic recording and reproducing.Conventional structure and problems thereof In recent years, with the improvement of recording density, the gap length accuracy and trunk width accuracy of the head have changed depending on the accuracy of the processing machine and the construction method. However, the gap depth of the heads is still unsatisfactory, with the exception of some heads (such as rotary heads for video table recorders). These are the characteristics of the head. For example, Figures 1 and 2 show conventional examples, and Figure 1 is a perspective view showing the structure of the head. 1
, has a magnetic gap 2, and the pair of magnetic cores 1 are welded with glass 3. 04 is a rectangular parallelepiped-shaped auxiliary part whose upper surface in contact with the tape is formed into a predetermined convex shape, and is adjacent to the magnetic core 1 in the trunk direction. The magnetic core 1 is fixed to the magnetic core 1 with an adhesive or the like. Also.

A coil 5 is wound around the center of the magnetic core 1 to form a magnetic head. Here, the auxiliary part 4 is the front surface 6 of the magnetic head.
It has the role of allowing a magnetic medium such as a magnetic tape to run smoothly, and when the magnetic core 1 is made of ferrite material, generally the auxiliary part 4 (is almost the same as the magnetic core 1).
An opaque ceramic coating material with a tenacity of 11 degrees (
For example, alumina.

[Forsterail, etc.] is often used, and it is impossible to directly measure the predetermined gap depth of the magnetic head when it is adhered to both sides of the magnetic core 1.

FIG. 2 is a front view seen from the direction of arrow Y in FIG.
FIG. 3 is a diagram for explaining the dimensional relationship necessary to indirectly know the predetermined gap depth D. FIG. In the figure, when machining the magnetic core 1, a dimension L1 is determined in advance using the A plane as a reference, and then a dimension L2 obtained by adding a predetermined gear knob depth D is processed and finished using the A plane as a reference. That is, similarly to the first method of determining Di from L2-L+, the dimension L4 is determined using the B plane as a reference when processing the magnetic core 1.

Processing and finishing is performed by a dimension L5, which is obtained by subtracting a predetermined cap depth D, using surface B as a reference. That is, there is a second method of finding D from L4-L5.

However, in both the first and second methods described above, there is an error in measuring the dimensions L+, L4, and L2.

It is only possible to obtain the gap depth D with an accuracy that includes errors during machining of the dimension L5. Therefore, the above-mentioned dimensional variations in the predetermined gap depth D have been one of the major causes of variations in head characteristics. However, since the head front surface 6 is mirror-finished in the final step, mechanical dimension measurement methods often cause scratches on the head front surface 6 (tape running surface).

OBJECTS OF THE INVENTION The present invention solves the above-mentioned problems of the conventional method, and provides a magnetic head that improves the precision in head manufacturing, eliminates the causes of variations in head characteristics, and improves the yield of head characteristics. That is.

Structure of the Invention In the magnetic head of the present invention, at least one of the auxiliary parts arranged in the trunk direction so as to sandwich a magnetic gap has a translucent prism shape, so that the auxiliary member having the prism shape can be passed through the auxiliary member.

This makes it possible to actually measure the gap depth.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 3 is a perspective view showing a head<ilt configuration according to an embodiment of the present invention. In the figure, 7 is a pair of magnetic cores made of ferrite, which is an oxide magnetic material.

It has a magnetic gap 8 at the top, and the pair of magnetic cores 7 are welded together with glass 9. Prism-shaped auxiliary members 11 made of transparent glass and having inclined surfaces 10 are disposed on both sides of the magnetic core 7 in the track direction across the magnetic gap 8, as in the conventional example. It is fixed. Furthermore, a coil 12 is wound around the magnetic core 7 to constitute a magnetic head.

FIG. 4 is a side view seen from the direction of arrow X in FIG.
When machining the bottom of the magnetic core, the dimension L5 is determined in advance using plane E as a reference, and then a predetermined gap depth Di is added to finish the dimension L6. In other words, L6-L5 + D is determined. but.

Here, in the conventional example, the gap depth D was determined by calculation including a measurement error, whereas in the present invention, the auxiliary part 1 having a prism shape is
1, the gap depth D can be directly measured as shown in FIG. Furthermore, since the measurement method is non-contact, there is no need to worry about damaging the front surface of the finished head.

In addition, in the above embodiment, a transparent glass prism was used as the auxiliary member 11, but when selecting the prism, transparent resin or a prism having the same level of yoke resistance as the magnetic core 7 may be used. Naturally, a material made of transparent resin mixed with glass or the like having a well-matched refractive index can also be considered as the auxiliary part 4:A11. still.

In the above embodiment, the auxiliary member 1 has the shape of a right-angled prism.
1, it goes without saying that it is possible to select an arbitrary shape for prisms of other shapes by considering the angle. Further, in the above embodiment, two auxiliary parts '4: A11, both of which have a prism shape, are adhesively fixed in the track direction across the magnetic gap 8 of the magnetic core 7.
This can only be done on one side. Further, the restrictions for the magnetic core 7 are also naturally applied to metallic magnetic materials other than ferrite.

Effects of the Invention As described above, the magnetic head of the present invention is capable of directly measuring the gap depth in addition to the calculated value, instead of determining the gap depth using only the conventional calculated value. The precision and control of different gap depths can be realized. Therefore, the cause of variations in head characteristics caused by variations in gap depth can be removed, and a highly accurate magnetic head with little variation in characteristics can be obtained.

[Brief explanation of the drawing]

1 and 2 are a perspective view and a front view of a conventional magnetic head, FIGS. 3 and 4 are a perspective view and a side view of an embodiment of the present invention, and FIG. 6 is a perspective view and a side view of an embodiment of the present invention. It is a microscopic perspective view of the main part. 7...Magnetic core, 8...Magnetic gap, 9
...Glass, 11 ... Auxiliary Department (J. Name of agent: Patent attorney Toshio Nakao and 1 other person 1st)
Figure 3v! J Fig. 4 Fig. 5FgJ

Claims (1)

[Claims] Of the auxiliary parts arranged in the track direction so as to sandwich the magnetic gap, at least one of them should have a translucent prism shape'c Q? Features a magnetic head.