JPH0240567Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a magnetic recording and reproducing device such as a video tape recorder (VTR).

(b) Prior Art In order to record information densely in a helical scan VTR, two magnetic heads with different azimuth angles are placed at two positions 180 degrees apart on a rotating body. Furthermore, in order to improve reproduction characteristics in special reproduction operations such as slow-motion reproduction, it has also been put into practice to arrange two magnetic heads having different azimuth angles close to each other (for example, at a distance corresponding to one horizontal scanning time). In particular, the two magnetic heads in the latter are called a double azimuth head.
In any of the above cases, since each magnetic head has an extremely small outer diameter, it is attached to the rotating body via a head base.

1 and 2 show the case where the double azimuth head is normally attached to the head base, FIG. 1 is a front view, and FIG. 2 is a side view seen from the direction of arrow A in FIG. 1. The magnetic heads H ₁ and H ₂ are mounted on a head base B such that tape contact surfaces H ₁₁ and H ₂₁ protrude from the outer peripheral surface B ₁ of the head base B. The magnetic head H ₁ has an operating gap g ₁ that is inclined by a constant angle −θ (−7° in the β method) with respect to the track extension direction;
H ₂ also has an operating gap g ₂ that is inclined by a constant angle +θ (+7° in the β method). Hereinafter, the former will be referred to as the A azimuth head, and the latter will be referred to as the B azimuth head, with the coil omitted for convenience of drawing (the same applies hereinafter).

It is best to install the A and B azimuth heads to the head base B while checking the operating gap using a microscope. However, if this check is omitted in consideration of work efficiency, it will cause problems if the lot control is not accurate. A defect occurs in which heads with the same azimuth are mounted on the head base B, or, as shown in FIG. 3, the A and B azimuth heads H ₁ and H ₂ are mounted on the head base B in a reversed manner.

In order to eliminate this problem, the external dimensions of the A and B azimuth heads should be made so different that they can be easily distinguished at a glance. For example, as shown in FIG. 4, the A azimuth head _H1 ' is different from the B azimuth head
Compared to H ₂ ', the height is D ₁ > D ₂ , but the width is E ₁ <
It is effective to change it so that E is as small as ₂ . However, on the other hand, it cannot be denied that there is a disadvantage in that it is necessary to prepare two types of processes that are significantly different in order to process the A and B azimuth heads.

(c) Purpose of the invention This invention was created in view of the above points.A.
It is an object of the present invention to provide a magnetic recording and reproducing apparatus equipped with a magnetic head in which the B azimuth head can be identified at a glance, while requiring no major changes in the processing steps for both heads.

(d) Structure of the invention The present invention is a magnetic recording/reproducing device equipped with two or more magnetic heads having different azimuth angles. The magnetic head is characterized in that a notch is provided on the adjacent outer surface to help distinguish the azimuth angle of the other magnetic head. When the magnetic recording/reproducing device is a helical scan VTR, one magnetic head and the other magnetic head are arranged 180 degrees apart from each other at two positions on the outer periphery of the rotating body. , and so-called double azimuth heads arranged close to each other.

(E) Embodiment FIG. 5 shows a plan view of the main structure of an embodiment of the device of the present invention. Reference numeral 1 denotes a rotary body which is arranged between upper and lower cylinders for guiding the running of the magnetic tape, and is rotated by a head motor for installing a rotating magnetic head in the gap between the two cylinders. First, second, and third magnetic heads 4, 5, and 6 are installed at two locations on the outer periphery of the rotating body 1 via head bases 2 and 3, respectively, so that the tape contact surface of each magnetic head faces outward. installed on. The first magnetic head 4 is an A azimuth head, and the second and third magnetic heads 5 and 6 are B azimuth heads. Note that the first and second magnetic heads are
They are mounted on the rotating body 1 180 degrees apart, and the third magnetic head 6 is arranged close to the first magnetic head (at a distance equivalent to one horizontal scan, for example, 556 μm).

FIG. 6 shows a partially enlarged plan view of FIG. 5. One magnetic head, that is, the first magnetic head 4
(In other words, A azimuth head) is the thickness of the core (approximately
190μ) is provided with a notch 7. This notch 7 has an opening 71 of approximately 225μ and a depth 72 of 200μ.
below the coil winding area 8 and on the lower surface 4
The height 9 from c is approximately 600μ. This is to prevent the coil winding work from getting in the way, and to prevent the core from being missing when the notch 7 is opened due to the bonding material-filled groove 4d provided for joining the core halves 41 and 42. It is. FIG. 7 is a perspective view showing the schematic structure of this magnetic head 4. As shown in FIG. Grooves 10 attached to both sides of each core half body 41, 42 are for defining the track width T, and each groove is filled with a glass material 11. 12 is a coil winding window.

The other magnetic head 5 has substantially the same structure as the A azimuth head, except that it is a B azimuth head and the notch 7 is not provided.

These A and B azimuth heads are obtained by slicing the head block 20 shown in FIG. 8 as indicated by broken lines 21 or 22 in FIG. However, for the A azimuth head, a groove 23 serving as the notch 7 is formed, while for the B azimuth head, slicing is performed without providing this groove. The steps up to forming this groove are common to AB azimuth heads.

FIG. 10 shows various changes in the notch for identifying the azimuth angle. A is a cutout with a V-shaped inner surface, B is a cutout with a chamfered shape, B is a cutout with a chamfered shape, C is a cutout attached to the core half side that does not have a coil window, and D is a cutout with a chamfered shape. It is equipped with multiple notches. By appropriately combining these, magnetic heads having various azimuth angles can be easily identified.

FIG. 11 shows still another embodiment, which is characterized in that a cutout is placed in the coil winding area. There is an advantage that the notch for identifying the azimuth angle also serves as a guide for the coil winding. Figures 11A and 11B show the A and B azimuth heads, respectively. The opening width of the notch is smaller in the former than in the latter.

(f) Effects of the invention The present invention allows the difference in azimuth angle to be easily distinguished by the notch provided in the core that can be discerned with the naked eye, so the efficiency of mounting to the head base can be improved. In addition, there is no need to significantly change the process of making magnetic heads with different azimuth angles, that is, the process for A and B azimuth heads is common until the final process, so
If the number of B azimuth heads becomes unbalanced, it is advantageous to be able to use A as B or B as A azimuth head.

[Brief explanation of the drawing]

Figures 1 and 2 show the mounting state (normal arrangement) of the double azimuth head on the head base.
FIG. 1 is a front view, and FIG. 2 is a side view. FIG. 3 is a front view of the incorrectly installed state, and FIG. 4 is a side view of a set of magnetic heads having different external dimensions. FIG. 5 is a plan view of the essential structure of one embodiment of the device of the present invention, and FIG. 6 is a partially enlarged plan view of FIG. 5. 7 is a schematic perspective view of the A azimuth head, FIG. 8 is a perspective view of the headblock, FIG. 9 is a plan view of the headblock, and FIG. 10 is a side view showing other embodiments of the notches. FIGS. 11A and 11B are side views of still another embodiment. Explanation of main drawing numbers, 4...One magnetic head (A
azimuth head), 5...the other magnetic head (B
azimuth head), 7...notch, 1...rotating body.

Claims (1)

[Claims for Utility Model Registration] (1) In a magnetic recording/reproducing device comprising two or more magnetic heads with different azimuth angles, one of the magnetic heads may be placed on any side surface other than the tape contact surface.
1. A magnetic recording/reproducing device characterized in that a notch is provided for identifying a difference in azimuth angle from the other magnetic head. (2) Utility model registration claim No. 1, characterized in that the one magnetic head and the other magnetic head are arranged at two positions on the outer circumferential side of the rotating body, separated by 180 degrees from each other. ) The magnetic recording and reproducing device described in item 2. (3) Utility model registration claim (1) characterized in that the one magnetic head and the other magnetic head are arranged close to each other at two positions on the outer circumferential side of the rotating body. The magnetic recording and reproducing device described above.