JPH07320246A - Method for reducing slide noise of magnetic head and magnetic head - Google Patents

Abstract

PURPOSE:To provide a method for reducing slide noise of magnetic head and a magnetic head capable of reducing the slide noise generated by oscillation due to contact with a magnetic tape. CONSTITUTION:The magnetic head 11 reproduces the magnetic tape 1 to out-put a RF signal, and a reproducing amplifier 12 amplifier the RF signal. A foodback amplifier 13 detects the oscillation of the magnetic head 11 generated by the beat as the electrical control signal based on the RF signal. A driver 15 amplifies the control signal to drive bimorphs 14a, 14b, and the bimorphs 14a, 14b oscillate a head chip 11a so as to cancel the oscillation due to contact with the magnetic tape 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of reducing sliding noise of a magnetic head and a magnetic head, and more particularly to a method of reducing sliding noise generated when a magnetic head and a magnetic tape contact and vibrate.

[0002]

2. Description of the Related Art For example, a video tape recorder (hereinafter referred to as V
It is called TR. The magnetic head of (1) has mechanical vibration called so-called "tataki", that is, when the magnetic head comes into contact with the magnetic tape, the magnetic head vibrates. An internal magnetic field is generated in a magnetic material when mechanical vibration is applied. This is known as the inverse effect of magnetostriction.

[0003]

When an internal magnetic field is generated in the magnetic material forming the magnetic head, noise is generated in a so-called RF signal output from the magnetic head.
This noise is called so-called sliding noise, which deteriorates the so-called C / N of the RF signal and, as a result, lowers the S / N of the VTR.

The present invention has been made in view of such circumstances, and a sliding noise reducing method for a magnetic head capable of reducing sliding noise generated by vibration caused by contact with a magnetic tape, and An object is to provide a magnetic head.

[0005]

In order to solve the above problems, a method of reducing sliding noise of a magnetic head according to the present invention outputs vibration of the magnetic head caused by contact with a magnetic tape from the magnetic head. Detected as an electrical control signal based on the generated RF signal, the control signal drives a piezoelectric element that moves the magnetic head in the contact direction with the magnetic tape, and sliding noise generated by vibration of the magnetic head. Is reduced.

Further, the magnetic head according to the present invention includes a vibration detecting means for detecting the vibration of the head chip caused by the contact with the magnetic tape as an electric control signal based on the RF signal, and the vibration detecting means. A piezoelectric element that moves the head chip in the contact direction with the magnetic tape according to the control signal is provided, and sliding noise generated by vibration is reduced.

[0007]

According to the present invention, the vibration of the magnetic head is detected as a control signal based on the RF signal output from the magnetic head, and the piezoelectric element is driven by this control signal to bring the magnetic head into contact with the magnetic tape. Move in the direction.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a magnetic head sliding noise reducing method and a magnetic head according to the present invention will be described below with reference to the drawings. In this embodiment, the present invention is applied to a magnetic head of a VTR, and FIG. 1 is a block diagram showing the configuration of the main part of this VTR.

That is, as shown in FIG. 1, the main part of this VTR is caused by contact between the magnetic head 11, the reproducing amplifier 12 for amplifying the RF signal from the magnetic head 11, and the magnetic tape 1. A field back amplifier 13 that detects the vibration of the magnetic head 11 as a control signal based on the RF signal from the reproduction amplifier 12, and a piezoelectric element 14 that moves the magnetic head 11 in the contact direction with the magnetic tape 1. A driver 15 that amplifies a control signal from the field back amplifier 13 and drives the piezoelectric element 14.

The magnetic head 11 is the magnetic tape 1
To reproduce an RF signal, and the reproduction amplifier 12 outputs an RF signal.
Amplify the signal. The field back amplifier 13 detects the vibration of the magnetic head 11 caused by the contact with the magnetic tape 1, that is, the vibration of the magnetic head 11 as an electrical control signal based on the RF signal amplified by the reproduction amplifier 12.

As shown in FIG. 1 described above, the piezoelectric element 14 is composed of two bimorphs 14a and 14b using the expansion and contraction of the piezoelectric material in the longitudinal direction, and moves the magnetic head 11 in the contact direction with the magnetic tape 1. It is supposed to do. Specifically, for example, as shown in FIG. 2, the bimorph 14a,
The head chip 11a of the magnetic head 1 is attached to one end of each of the 14b.
The other end of each of b is attached to the holder 16. When a voltage is applied, the bimorphs 14a and 14b move the head chip 11a in the contact (contact) direction with the magnetic tape 1 with the other end attached to the holder 16 as a fulcrum. There is.

The driver 15 amplifies the control signal supplied from the field back amplifier 13 to generate the bimorph 1
4a and 14b are driven, and the bimorphs 14a and 14b are
The head chip 11a is moved (vibrated) so as to cancel the vibration caused by the contact with the magnetic tape 1. Thus, vibration caused by the contact of the magnetic head 11 with the magnetic tape 1 is prevented, and sliding noise generated in the RF signal can be reduced. That is, the S / N ratio of the VTR can be improved, and the wear of the magnetic head can be prevented.

By the way, the timing for detecting the control signal is VT for the cassette storing the magnetic tape 1.
Immediately after so-called threading after loading into R. Alternatively, the time may be when the area in which the video signal is not recorded is being reproduced.

Further, the above-mentioned bimorphs 14a, 14b.
The movement of the head chip 11a according to the above is based on the principle of the so-called dynamic tracking method used in the conventional VTR. That is, in the dynamic tracking method, as shown in FIG. 3, bimorphs 22a and 2a mounted on the holder 21 in parallel with each other.
By 2b, the head chip 23 is moved in the track width direction to perform tracking.

It is needless to say that the present invention is not limited to the above-mentioned embodiment of the VTR, and the present invention can be applied to, for example, an apparatus using a helical can system such as a digital VTR, a so-called DAT. In these cases, the effect is that the error rate can be improved.

[0016]

As apparent from the above description, in the present invention, the vibration of the magnetic head is detected as a control signal based on the RF signal output from the magnetic head, and the piezoelectric element is driven by this control signal. By moving the magnetic head in the contact direction with the magnetic tape, it is possible to prevent vibration caused by the contact of the magnetic head with the magnetic tape and reduce sliding noise. In other words, VTR
It is possible to improve the S / N of the magnetic head and to prevent wear of the magnetic head.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a main part of a VTR to which the present invention is applied.

FIG. 2 is a schematic diagram showing a mounting mechanism of a head chip.

FIG. 3 is a schematic diagram for explaining a dynamic tracking method.

[Explanation of symbols]

 11 magnetic head 11a head chip 13 field back amplifier 14 piezoelectric element 14a, 14b bimorph

Claims (2)

[Claims] 1. A vibration of a magnetic head caused by contact with a magnetic tape is detected as an electrical control signal based on an RF signal output from the magnetic head, and the control signal causes the magnetic head to move to a magnetic field. A method for reducing sliding noise of a magnetic head, which comprises driving a piezoelectric element that moves in the direction of contact with the tape to reduce sliding noise generated by vibration of the magnetic head. 2. A vibration detecting means for detecting vibration of a head chip caused by contact with a magnetic tape as an electric control signal based on an RF signal, and the control signal from the vibration detecting means for the head chip. And a piezoelectric element that moves in the direction of contact with the magnetic tape to reduce sliding noise generated by vibration.