JPS6227451B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotating magnetic head device, and more particularly, a magnetic head support member that supports a magnetic head at both ends and rotates within a drum is oscillated relative to the drum rotating surface by the action of an electromagnetic drive means. In a device configured to tilt dynamically and displace the magnetic head in a direction that intersects the recording track on the magnetic tape, by supporting the central portion of the magnetic head support member with an elastic member having damper properties, the resonance of the elastic member itself can be suppressed. It is an object of the present invention to provide a rotating magnetic head device configured to reduce the influence and perform tracking operations with high precision.

Currently, magnetic recording and reproducing devices employ a high-density recording method in which the track width is narrowed and the tracks are closely placed on the magnetic tape without a guard band. It is necessary to scan the recording track with high precision. Therefore, in order to improve the tracking accuracy, the present applicant previously proposed in Japanese Patent Application No. 15348/1983, etc., a magnetic head support member that supports a magnetic head at both ends and rotates against a rotating surface by the action of electromagnetic force. The present invention has proposed a device in which the magnetic head can faithfully follow even a distorted track by tilting the magnetic head and displacing the magnetic head in the track width direction.

This device is installed in a drum around which a magnetic tape runs, and includes a magnetic head support member that rotates with a magnetic head supported at both ends, and a magnetic head support member that rotates with the magnetic head supported at both ends. It is generally composed of a mechanism that swingably supports the central portion so as to be inclined with respect to a plane, and an electromagnetic drive mechanism that applies a swinging force to the magnetic head support member. Here, the swingable support mechanism is composed of a leaf spring formed into a predetermined shape. A leaf spring is a pure elastic body, and the frequency characteristics of the magnetic head support member (including the magnetic head) are as shown by the curve in Figure 6, and at resonance, it has a high Q (damper coefficient).
exhibit a value. For this reason, the influence of the high Q value at the time of resonance appears when the magnetic head support member oscillates during playback, and the movement locus of the magnetic head becomes disturbed with respect to the input signal waveform to the electromagnetic drive mechanism. However, there was a problem that accurate tracking operation was not performed.

The present invention solves the above problems, and each embodiment thereof will be described below with reference to the drawings.

FIG. 1 is a plan view of a first embodiment of a rotating magnetic head device according to the present invention with the upper rotating drum removed, and FIGS. 2 and 3 are respectively shown in FIG.
FIG. 4 is an exploded perspective view of the device shown in FIG. 1;

In each figure, a rotating magnetic head device 1 consists of a lower stationary drum 2 and an upper rotating drum 3, around which a magnetic tape 4 runs. The rotating shaft 5 is rotatably supported by bearings 6a and 6b, and a base plate 7 is fitted and fixed thereto. The rotating drum 3 is fixed to the base plate 7 with screws while being fitted onto the rotating shaft 5. The rotating transformer 8 includes a fixed winding mounting section 9 fixed to the fixed drum 2 and a rotating winding mounting section 10 fixed to the base plate 7.

The magnetic heads 11a and 11b are connected to the bracket 1, respectively.
2a and 12b, and each bracket is fixed to both ends of the head mounting body 13 with screws 14a and 14b. The head mounting body 13 has its center hole 13a fitted into the protruding flange 15c of the rotating member 15, and screws 16a, 1 are attached to the upper surface of the rotating member 15.
6b. The rotating member 15 has yoke portions 15a and 15b formed at both ends thereof.

Reference numeral 20 denotes a seesaw plate, which is loosely fitted onto the rotating shaft 5 and is slightly lifted from the fixed seesaw base 21 (dimension x) between the pair of rubber blocks 22.
a, 22b. The fixed seesaw base 21 is fixed onto the base plate 7 with screws 23a to 23d.

The rubber blocks 22a and 22b are essential parts of the present invention, and are made by cutting an elastic board made of urethane rubber or silicone rubber, which has appropriate hardness and exhibits damper properties, into a rectangular shape, and has the upper and lower ends thereof cut into a rectangular shape. Fitting holes 24a, 2 of fixed seesaw base 21
4b, and the fitting hole 25 of the seesaw plate 20
a, 25b and fixed with adhesive or the like.
Moreover, these rubber blocks 22a, 22b are
The magnetic heads 1 on both sides pass through the center of the rotating shaft 5.
1a and 11b (corresponding to the - line in Fig. 1), and are arranged on the left and right sides of the rotating shaft 5 at symmetrical positions with respect to this line. There is. Furthermore, these rubber blocks 22a, 22b have a straight line (-
line), and its thickness (t) direction is aligned with the straight line (
- line), and bends and deforms in the - line direction.

The assembly consisting of the head mounting body 13 and the rotating member 15 is fixed on the seesaw plate 20 with screws 26a to 26d, with the magnetic heads 11a and 11b aligned in the direction of curvature of the rubber blocks 22a and 22b. There is. As a result, the head mounting body 13 etc. can be attached to the rubber blocks 22a, 22b.
With bending deformation, the magnetic heads 11a, 11
A seesaw movement is performed with respect to the drum rotating surface centering on the rotating shaft portion so that b is respectively displaced in the vertical direction.

In addition, 27a and 27b are height adjustment screws, which are screwed into the rotating member 15 at symmetrical positions with respect to the linear-linear rotating shaft 5, and the lower end portions are connected to the seesaw plate 20 and the fixed seesaw base 20.
holes 28a, 28 of the base plate 7
b, and protrudes below the base plate 7 by loosely fitting through it.

Further, inside the rotating magnetic head device 1, a first electromagnetic drive mechanism 30 for operating the magnetic head seesaw, and a second electromagnetic drive mechanism 31 for fixing the magnetic head are provided.
is incorporated.

The first electromagnetic drive mechanism 30 is provided in relation to the rotating member 15, and each of the yoke portions 15a, 15
Permanent magnet pieces 32a and 32b are provided in the yoke portions 15a and 15b to generate magnetic fields of opposite polarity within the yoke portions 15a and 15b. It has a built-in structure. The coil winding frame 33 is fixed to the lower fixed drum 2.

The second electromagnetic drive mechanism 31 includes a base plate 7
A magnetic circuit section 36 is disposed inside the magnetic circuit section 36 and is supported by the base plate 7 via an annular damper member 35. It consists of a drive coil 38 located at. Magnetic circuit section 3
6 is a position regulating member 39 and an annular permanent magnet 40
and a magnetic path forming member 41.

Next, the operation of the rotating magnetic head device having the above structure will be explained with reference to FIGS. 5 and 6.

In the recording mode, a direct current is applied to the drive coil 38 to put the second electromagnetic drive mechanism 31 into operation. That is, the magnetic circuit section 36 is displaced upward, and the flange section 39a of the position regulating member 39 is pressed against the lower surface 7a of the base plate 7. At this time, the lower ends of the height adjustment screws 27a, 27b are pushed by the flange portion 39a, the position of the rotating member 15 is regulated, and the magnetic heads 11a, 11b are fixed at the reference positions. The magnetic heads 11a and 11b rotate in this fixed state and form tracks on the magnetic tape 4.

In the playback mode, the second electromagnetic drive mechanism 31 is inactive, and the first electromagnetic drive mechanism 30 is in the active state. A tracking control signal corresponding to the tracking error of the magnetic head is sent to the drive coil 3.
4, each yoke portion 1 of the rotating member 15
5a and 15b are subjected to forces in opposite directions, and the rotating member 15 is rotated against the rubber blocks 22a and 22.
With the bending deformation of b, the seesaw plate 20,
It swings together with the head mounting body 13. This results in
The magnetic heads 11a and 11b are displaced in the track width direction and scan the curved video track to follow it.

FIG. 5 shows that the head mounting body 13 is attached to the rubber block 2.
This is a diagram schematically showing a state in which 2a and 22b swing with bending deformation.

Here, the rubber blocks 22a and 22b themselves have the property of acting as dampers.
The frequency characteristics of the oscillating magnetic head support part are as follows.
As shown by the curve in the figure, the Q value at resonance is considerably reduced compared to the conventional one. Therefore, the degree of influence of the Q value during the swinging motion of the head mounting body 13 is almost eliminated, and the head mounting body 13 swings faithfully in accordance with the tracking control signal. , 11b faithfully scan the curved video track, and the tracking operation is performed with high precision.

Note that when the tracking control signal is zero and the first electromagnetic drive mechanism 30 is not operating, the head mounting body 13 always elastically returns to a predetermined position due to the elastic force of the rubber blocks 22a and 22b.

Next, a second embodiment of the rotating magnetic head device according to the present invention will be described with reference to FIG. The present device is constructed so that when the head mounting body 13 swings, the rubber block does not bend but twists. In FIG. 7, components that are substantially the same as those shown in FIGS. 1 to 4 are given the same reference numerals, and their explanations will be omitted.

The rubber blocks 50a and 50b are elongated rectangular blocks that can be torsionally deformed in the direction of the arrow.
It is fitted into the U-shaped recesses 52a and 52b of 51b and fixed with adhesive. Each holder member 51a, 51b
is fixed on the base plate 7.

That is, the rubber blocks 50a and 50b have their torsional axes aligned with a line that passes through the center of the rotating shaft 5 and is perpendicular to the straight line connecting the magnetic heads 11a and 11b on both sides, and are symmetrical about the rotating shaft 5. It is placed in a certain position.

The rotating member 15, as in the above embodiment,
Due to the action of electromagnetic force, the magnetic heads 11a, 11b
The rubber blocks 50a and 50b are torsionally deformed and oscillate relative to the drum rotating surface. The frequency characteristics of the oscillating parts are the same as those of the rubber blocks 50a, 5.
0b is used, as in the case of the above embodiment, as shown by the curve in FIG. , 11b scan by faithfully following the video track.

As described above, according to the rotating magnetic head device according to the present invention, the magnetic tape is disposed inside the drum that runs while being attached to the periphery of the magnetic tape.
A rotating magnetic head support member with magnetic heads attached at 180-degree symmetrical positions, and a mechanism that swingably supports the central portion of the magnetic head support member so as to be inclined with respect to a plane orthogonal to the rotation axis. and an electromagnetic drive mechanism that applies a rocking force to the magnetic head support member, and since the central part of the magnetic head support member is supported by a rubber member, the rocking force is reduced. The Q value when the system resonates has been significantly reduced compared to the conventional system, and the magnetic head support member can be oscillated faithfully by an electromagnetic drive mechanism in response to, for example, a tracking control signal, making it possible to perform tracking operations with high precision. Since it is a rubber member, it has the advantage of being able to reduce costs.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a first embodiment of a rotating magnetic head device according to the present invention with the upper rotating drum removed, and FIGS. 2 and 3 are respectively shown in FIG.
Fig. 4 is an exploded perspective view of the device shown in Fig. 1, and Fig. 5 is a longitudinal sectional view taken along the line and - line, Fig. 5 is a see-saw movement of the head mounting body in Figs. Fig. 6 is a diagram showing the frequency characteristics of the oscillating system of the device of the present invention in comparison with the frequency characteristics of the oscillating system of the conventional device, and Fig. 7 is a diagram showing the frequency characteristics of the oscillating system of the device of the present invention. FIG. 7 is an exploded perspective view of main parts of the second embodiment. DESCRIPTION OF SYMBOLS 1... Rotating magnetic head device, 2... Fixed drum, 3... Rotating drum, 4... Magnetic tape, 5...
...Rotating shaft, 7... Base plate, 8... Rotating transformer, 11a, 11b... Magnetic head, 13...
... Head mounting body, 15 ... Rotating member, 15a, 1
5b... Yoke part, 15d, 15e... Notch part,
20... Seesaw plate, 21... Fixed seesaw base, 22a, 22b... Rubber block, 2
4a, 24b, 25a, 25b...fitting hole, 30
...First electromagnetic drive mechanism, 32a, 32b...Permanent magnet piece, 33...Coil winding frame, 34...Drive coil, 50a, 50b...Rubber block, 51
a, 51b...Holder member, 52a, 52b...
...U-shaped recess.

Claims (1)

[Claims] 1. A rotating magnetic head support member, which is provided in a drum around which a magnetic tape runs, and which rotates with magnetic heads attached at positions 180 degrees symmetrical about the center of rotation; a mechanism that swingably supports the central part of the member so as to be inclined with respect to a plane perpendicular to the rotation axis;
A rotating magnetic head device comprising an electromagnetic drive mechanism for applying a rocking force to the magnetic head support member, the rotating magnetic head device characterized in that a central portion of the magnetic head support member is supported by a rubber member. .