JPH05342541A - Magnetic head device - Google Patents

Abstract

PURPOSE:To maintain the contact state with a magnetic tape in a specified state at the time when the front end of the magnetic head advances toward or leaves the magnetic tape. CONSTITUTION:Displaceable projecting parts 2, 3 are provided above and below so as to hold the magnetic head 1 in-between. The sides at one end of the displaceable projecting parts 2, 3 are joined to lamination type piezoelectric elements 2a, 3a. A voltage is impressed to the lamination type piezoelectric elements 2a, 3a, by that, the front ends of the displaceable projecting parts 2, 3 are displaced in the direction to the front end of the magnetic head. A revolution position detector 11 detects the rotating position of the magnetic head 1 on a rotary drum. A displacement control circuit 12 controls the voltage to be impressed to the lamination type piezoelectric elements 2a, 3a according to the rotating position of the magnetic head.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head device,
Particularly, the present invention relates to a magnetic head device mounted on a rotary drum of a helical scan type magnetic recording / reproducing device.

[0002]

2. Description of the Related Art In a conventional helical scan type magnetic recording / reproducing apparatus, a magnetic head device as shown in FIG. 3 is fixed to a rotary drum (not shown), and the magnetic head device is wound around the rotary drum in a helical shape to run. The magnetic head 21 rotates on the magnetic tape surface to record and reproduce signals.

[0003]

In the above-described conventional magnetic head device, during recording / reproduction, when the tip of the magnetic head obliquely enters from one end of the magnetic tape and when it obliquely leaves from the other end, the magnetic head The tape may be deformed to change the contact state with the magnetic tape, or the magnetic tape may vibrate. Therefore, there is a problem that recording and reproduction are disturbed and stable high-quality recording and reproduction cannot be performed.

An object of the present invention is to provide a magnetic head device capable of maintaining a constant contact state with the magnetic tape when the tip of the magnetic head enters and leaves the magnetic tape, and enables stable high-quality recording and reproduction. To do.

[0005]

A magnetic head device according to the present invention is a magnetic head device mounted on a rotary drum for recording / reproducing signals on / from a magnetic tape surface, and a magnetic head for recording / reproducing signals. The magnetic head is sandwiched between the upper and lower parts, and the plurality of displacement protrusions are arranged in a direction normal to the surface of the magnetic tape. The displacement protrusions are respectively displaced. To be done. Further, it is provided with a control means for independently displacing the plurality of displacement protrusions according to the rotational position of the rotary drum.

[0006]

The present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the present invention. Here, the magnetic head 1 is fixed to a head base 4 to be attached to a rotary drum (not shown), and displacement protrusions 2 and 3 are provided vertically so as to sandwich the magnetic head 1. .

Further, one ends of the displacement protrusions 2 and 3 are bonded to the laminated piezoelectric elements 2a and 3a, respectively. By applying a voltage to the laminated piezoelectric elements 2a and 3a, the displacement protrusion 2 is formed. , 3 can be displaced back and forth. In this case, the tips of the displacement protrusions 2 and 3 are displaced in the tip direction to positions close to the tips of the magnetic head 1.

FIG. 2 is a diagram showing a contact state between the magnetic head device and the magnetic tape. When the magnetic head 1 obliquely enters the lower end of the magnetic tape 5, as shown in FIG. Type piezoelectric element 2a by applying voltage to the displacement protrusion 2
Is gradually displaced forward. By controlling in this way, the displacement protrusion 2 gradually pushes up the magnetic tape 5 to absorb the impact, so that the deformation and vibration of the magnetic tape can be prevented.

As the magnetic head 1 moves to the middle of the magnetic tape, as shown in FIG. 2B, a voltage is also applied to the laminated piezoelectric element 3a to gradually displace the displacement protrusion 3 forward.

As the magnetic head 1 approaches the upper end of the magnetic tape, as shown in FIG. 2C, the voltage applied to the laminated piezoelectric element 2a is lowered to gradually displace the displacement protrusion 2 rearward. By controlling in this way, the displacement protrusion 2 absorbs the impact at the time of detachment, so that the deformation and vibration of the magnetic tape can be prevented. Therefore, the contact state between the magnetic head 1 and the magnetic tape 5 can be kept constant, and stable high-quality recording / reproduction can be performed.

By the way, in order to control the laminated piezoelectric elements 2a and 3a as described above, for example, a rotational position detector 11 for detecting the rotational position of the rotary drum, and an applied voltage depending on the rotational position of the rotary drum. Displacement control circuit 1 for controlling
2 may be provided.

[0013]

As described above, according to the present invention, a plurality of displacement protrusions are arranged vertically so as to sandwich the magnetic head, and the displacement protrusions are arranged in accordance with the rotational position of the rotary drum.
By independently displacing the magnetic head in the direction normal to the magnetic tape surface, the impact when the tip of the magnetic head enters and leaves the magnetic tape can be mitigated, so that the deformation and vibration of the magnetic tape can be prevented, and therefore the magnetic The contact state between the head and the magnetic tape can be kept constant, and stable high-quality recording / reproduction can be performed.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

2A and 2B are diagrams showing the operation of the magnetic head device shown in FIG. 1, where FIG. 2A shows the magnetic head entering the lower end of the tape, and FIG. 2B shows the magnetic head in the middle of the tape. , (C) show when the magnetic head is detached from the upper end of the tape.

FIG. 3 is a perspective view showing an example of a conventional magnetic head device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic head 2 and 3 Displacement protrusion 2a and 3a Multilayer piezoelectric element 11 Rotational position detector 12 Displacement control circuit

Claims (2)

[Claims] 1. A magnetic head device mounted on a rotating drum for recording and reproducing signals on and from a magnetic tape surface,
Magnetic heads for recording / reproducing signals, a plurality of displacement protrusions arranged vertically above and below the magnetic heads and displaced in the direction normal to the surface of the magnetic tape, and a plurality of displacement protrusions. And a means for displacing the magnetic head and the magnetic head, respectively. 2. The magnetic head device according to claim 1, further comprising control means for independently displacing the plurality of displacement protrusions according to a rotational position of the rotary drum. .