JPS6138526B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION An object of the present invention is to provide a magnetic head device in which first and second magnetic head chips can be mounted on a single head base with high precision.

In a helical scan type video tape recorder, in order to improve the playback quality in the special playback mode, a pair of heads are installed at a 180 degree angle on the head rotating body that rotates within a cylindrical guide cylinder. A technique is used in which, together with the main magnetic head, a sub-magnetic head is placed close to the main magnetic head in order to compensate for the loss of tracking. If the spacing between the main and sub magnetic heads is sufficiently large as shown in Figure 1, each magnetic head can be attached to the head rotating body at the correct position via the head base, but the spacing is extremely large. When it is necessary to make the magnetic heads close to each other, it is extremely difficult, almost impossible, to attach the head bases to the head rotating body so that the distance between the magnetic heads falls within a permissible value. This is because each magnetic head cannot be held down with a suitable jig, and the rotational force generated when the head base is screwed to the head rotating body cannot be prevented. Therefore, two magnetic heads are attached to one head base. A conventional example of such a structure is JP-A-49-104614. In this conventional example, the front side of the core is divided into two parts by a groove, and a magnetic head is attached to each part, but the two magnetic heads are relatively far apart and are even closer together. It is not intended and is an impossible structure to do so.

The present invention connects two magnetic head chips on one head base in close proximity to each other in a correct positional relationship, and also improves the workability of attaching the head base of the head rotating body to the same level as that of a conventional single magnetic head. This is an attempt to simplify the process.

Next, the apparatus of the present invention will be explained based on illustrated embodiments. FIG. 2 shows the apparatus of this embodiment together with a head rotating body, where A is a plan view, B is a front view, and C is a sectional view from the center side. In the figure, 1 is a head rotating body, 2 is a head base, and 3 and 4 are magnetic head chips having windings 5 and 6, respectively. The rotation of the head rotating body 1 is controlled within the cylindrical guide cylinder 7, and the head base 2 is rotated every half rotation.
The magnetic tape is configured to scan a predetermined track on the magnetic tape running around the circumferential surface of the cylindrical guide cylinder 7 by each magnetic head chip disposed on a head base (not shown) provided symmetrically thereto. ing. In addition, this head rotating body 1
has screws 8 for screwing the head base 2.
It is provided with a screw hole 9 for mounting the head base, and further provided with adjustment screw holes 10 and 11 so that adjustment screws can be applied to first and second parts of the head base, which will be described later.

The head base 2 has a screw through hole 12 at its base, and a separation groove 13 extending in the radial direction at the center, and each magnetic head chip 3, 4
The first and second portions 14 and 15 are formed for the purpose. The head base 2 is made of non-magnetic metal (brass), and each end of the windings 5 and 6, which are wound after the magnetic head chip is bonded to the head base, is connected to the head base 2 and the head rotation. The lead is connected to a printed circuit board 18 on the back surface of the head rotating body 1 through lead insertion holes 16 and 17 in the body 1. Magnetic head tip 3,
4 has a shape in which narrow core halves 3a, 4a and wide core halves 3b, 4b are joined facing each other, and the magnetic head chips 3, 4 are connected to the first and second parts of the head base 2.
The parts 14 and 15 are joined with instant adhesive, but in order to accurately define the position of the magnetic head chip relative to the head base, each magnetic head chip is positioned relative to the head base 2, and then the adhesive is applied. I try to do that. At this time, the narrow core halves 3a and 4a are arranged so as to protrude from the head base 2 onto the separation groove 13. If adhesive flows into the mounting area of the other magnetic head chip during the bonding process of the first magnetic head chip, subsequent magnetic head chips must be installed with high precision only after removing this flowing adhesive that has already hardened. I can't. In the device of the present invention, the first and second portions 14,
The separation groove 13 dividing the magnetic head chips 15 extends sufficiently rearward from the rear ends of the magnetic head chips 3 and 4 to prevent the adhesive from flowing.
Each magnetic head chip can be precisely bonded to a predetermined position on the second portions 14,15. In this bonding process, it is relatively easy to regulate the position of the magnetic head chip relative to the head base in the plane direction, but when regulating the position in the height direction, the adhesive also flows between the abutting surfaces of the head base 2 and the magnetic head chips 4 and 5. It may not be done correctly due to some reasons. This adjustment in the height direction can be performed by displacing the first and/or second portions 14, 15 against their own elasticity using adjustment screws 19, 20 which are screwed into the adjustment screw holes 11. The presence of the separation groove 13 clearly contributes to making this adjustment in the height direction also independent for each magnetic head chip. Note that 21 and 22 are adhesive layers.

As described above, the apparatus of the present invention has the advantage that each magnetic head chip can be joined at the correct position, and the distance between the gap of each magnetic head chip can be significantly shortened.
The head base to which each magnetic head chip is attached can be easily attached to the head rotating body with one screw, with workability similar to that of a conventional head with a single magnetic head chip. Further, the separation groove on the head base contributes to improving the workability of attaching each magnetic head chip to the first and second parts, and further enables independent adjustment in the height direction.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a conventional device. Fig. 2 shows the device of the present invention together with a head rotating body, in which Fig. A is a plan view, Fig. B is a front view, and Fig. C is a sectional view from the center of Fig. A. 2... Head base, 3, 4... First and second magnetic head chips, 3a, 4a... Narrow core half, 3
b, 4b...wide core half, 13...separation groove, 1
4, 15...first and second parts.

Claims (1)

[Claims] 1. A magnetic head device in which first and second head chips are respectively bonded to substantially separate first and second portions of one head base,
The first and second parts are separated by a separation groove provided rearward from the front end of the head base, and the separation groove extends sufficiently rearward than the rear end of the head chip attached to the head base. the head chip has a shape in which a narrow core half and a wide core half are joined facing each other, and the wide core half is joined to the head base;
In the magnetic head device, the narrow core half protrudes from the head base onto the separation groove.