JPH048854B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to the arrangement of a magnetic head in a head drum device used for magnetic recording.

Conventional configurations and their problems Head drum devices have been widely used with the development of VTRs, and in recent years, a recording system in which luminance signals and color signals are recorded using separate magnetic recording heads has been put into practical use, especially in broadcast VTRs. ing. In such a recording system, a head drum device is used in which a plurality of magnetic heads are arranged in a set close to each other at predetermined intervals on one head drum.

FIG. 1 shows the shape of a magnetic head (hereinafter simply referred to as head) used in a conventional head drum device. Head 1 is provided with a gap 2;
The front surface 3 is processed into an arcuate surface so that the gap 2 protrudes the most.

FIG. 2 shows a first example of a conventional head drum device in which the heads 1 shown in FIG. 1 are arranged in pairs on a head drum 4 at a predetermined interval 5 as described above. In this example, the two heads 1 are mounted symmetrically with respect to a line 8 passing through the center of rotation 9 of the head drum 4, the gap 2 of each head 1 and the side surface of the head are parallel to the line 8, and the bottom surface of the head is parallel to the line 8. It is perpendicular to 8. In a head drum device having such a structure, even when the heads 1 are worn out, the distance 5 between the heads hardly changes, and the distance 5 between the two heads 1
Since they are parallel, there is no need to determine the mounting angle of the head 1, and there is an advantage that assembly is easy. However, as shown in FIG.
Since the centers 10 of the circles of the arcuate surfaces do not overlap, a distance 6 deviates between the most protruding position 3' of the head 1 and the gap 2, which makes the contact between the gap 2 and the magnetic recording tape unstable, and the head In addition, the shoulder portion 7 of the head protrudes outward from the head drum 4, causing impactful contact between the head and the tape, resulting in worsening of jitter.

FIG. 4 shows a second conventional example different from the first example explained with reference to FIGS. 2 and 3 above. In this example, two heads 1 are used as in the first example above.
are arranged on the head drum 4 at a predetermined distance 5, with the gap 2 of each head 1 facing the rotation center 9 of the head drum 4.
In this case, as shown in FIG. 5, the center 10 of the circle of the arcuate surface of the front surface 3 of the head is on the line connecting the gap 2 and the center 9 of the head drum 4, so the position of the gap 2 and the arcuate surface are Since the most protruding positions from the head drum coincide, the problem like the first conventional example does not occur, but since the directions of the gap 2 of each head 1 are attached to the head drum 4 at a relative angle, two Due to the wear of the heads 1, the spacing 5 between the heads changes at twice the rate of the displacement 11 caused by the wear of a single head. Also, head 1
When installing the head, the head must be installed at a relative angle as described above, so the angle must be determined, making the head installation work complicated.

Purpose of the Invention The present invention solves the problems in the first and second conventional examples described above, and provides stable contact between the heads and the tape, the spacing between the heads does not change even if the heads wear out, and The object of the present invention is to provide a head drum device that is easy to install.

Structure of the Invention The present invention provides a head drum device in which a plurality of magnetic heads are arranged close to each other at predetermined intervals, and the center of the circle on the front surface of each magnetic head is connected to the gap between the gap and the head drum. The position of the part of the magnetic head that protrudes most from the head drum is aligned with the position of the gap so that it is on a line connecting the centers, and the direction of each gap is aligned between the midpoint between the gap of the adjacent magnetic head and the head drum. It is arranged so that it is parallel to the line connecting the centers of.

DESCRIPTION OF THE EMBODIMENTS FIG. 6 shows the relative position of the magnetic head with respect to the head drum of an embodiment of the head drum device of the present invention. In the figure, a pair of two magnetic heads 1 are mounted on a head drum 4 with a predetermined distance 5 between them. A plurality of heads are provided parallel to each other so that the gap 2 of each head 1 is parallel to a line connecting the midpoint between the gaps of two adjacent heads and the rotation center 9 of the head drum, and The center 10 of the circle of the arcuate surface 3 on the front surface of each head is the gap 2 of that head.
The outer surface of the head 1 other than the front surface 3 is substantially parallel to or perpendicular to the line 8.

When the relative positions of the head 1 and the head drum 4 are set in this manner, the position where the head 1 protrudes from the head drum coincides with the position of the gap 2, and the contact between the head 1 and the tape is stabilized. Furthermore, even if the heads 1 wear out, the spacing 5 between the heads does not change much.
The protrusion of the shoulder portion 7 of the head 1 from the head drum 4 is reduced, and the effect that the beginning of contact between the head and the tape becomes smooth can be obtained. Furthermore, the direction of the gap 2 can be formed parallel or at right angles to the outer surface of the head 1, and the plurality of heads can also be arranged almost parallel to the outer surface, which is advantageous in terms of increasing the precision of processing and assembly. It is.

Effects of the Invention As described above, according to the present invention, by making the outermost protruding position of the head coincide with the position of the gap, and by making the gap direction of a plurality of heads the same, the head and the tape can be separated. It is possible to stabilize the contact, to reduce fluctuations in the gap between the gaps of each head even when the heads are worn, and to easily assemble the head drum and the head with high precision.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the shape of a conventional magnetic head, Fig. 2 is a first example of a conventional head drum device equipped with a plurality of magnetic heads, Fig. 3 is an enlarged view of its main parts, and Fig. 4 is a diagram showing the shape of a conventional magnetic head. FIG. 5 is an enlarged view of the main parts of a second example of a conventional head drum apparatus, and FIG. 6 is a diagram showing the main parts of an embodiment of the head drum apparatus of the present invention. 1... Magnetic head, 2... Gap, 3... Arc surface on the front of the head, 4... Head drum, 7...
Shoulder of the magnetic head, 9... Center of rotation of the head drum, 10... Center of the arcuate surface 3.

Claims (1)

[Claims] 1. In a head drum device in which a plurality of magnetic heads are arranged as a set on a single head drum in close proximity to each other, the center of the circle on the front surface of each magnetic head in the set is located between the gap of the magnetic head and the head drum. On the line connecting the rotation centers of
A head drum device characterized in that the direction of the gap of each magnetic head is parallel to a line connecting the center of rotation of the head drum and the midpoint between the gaps of adjacent magnetic heads.