JPS6110393Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a magnetic recording/reproducing device equipped with a rotating magnetic head device.

Generally, this type of magnetic recording and reproducing device, such as a video tape recorder (hereinafter simply referred to as VTR), is commonly used.
Since the recording/reproducing magnetic head disposed on the rotating drum of the rotating magnetic head device is always in sliding contact with the magnetic tape, there is a problem in that the magnetic head and the magnetic tape are subject to significant wear and tear. ing.

In addition to the normal recording/playback mode, it also has special playback modes that switch the running speed of the magnetic tape, such as still playback, slow-motion playback, or fast-motion playback.
In a VTR, it is necessary to enable a magnetic head disposed in a rotating magnetic head device to accurately trace recording tracks formed on a magnetic tape in response to various tape running speeds.
Simply changing the running speed of the magnetic tape will not work.
As shown by the dashed line in FIG. 1, the magnetic head is traced over the recording tracks TR ₁ and TR ₂ , resulting in significant deterioration of image quality due to so-called guard band noise. Conventionally, in order to prevent the occurrence of guard band noise in the above-mentioned special reproduction mode, the magnetic head disposed in a rotating magnetic head device is
A wobbling method is used in which the device is movable using an electromechanical transducer such as a bimorph and controlled to trace the correct recording track TRa. The trace state of the magnetic head when the above wobbling method is applied is as follows.
Indicated by a broken line in the figure. The above wobbling method is
Conventionally, it has been applied only to special playback modes as described above.

A rotating magnetic head having a pair of fixed magnetic heads on a rotating drum used for recording or normal reproduction of signals, and a pair of movable magnetic heads on the rotating drum used for special reproduction of signals supported by electromechanical transducers. The head device includes a recording operation and a normal reproducing operation using the pair of fixed magnetic heads while slightly vibrating the pair of movable magnetic heads, and special reproducing operations such as a still reproducing operation are performed by moving the pair of movable magnetic heads. By creating a magnetic recording and reproducing device that uses this movable magnetic head to perform both the tracking operation by bling, damage caused by friction between the magnetic head and the magnetic tape can be reduced, and a special reproducing operation can also be performed. It is an object of the present invention to provide a magnetic recording and reproducing device with a novel configuration that can perform image quality without deterioration due to guard band noise or the like.

Hereinafter, the present invention will be described in detail with reference to the drawings showing one embodiment.

FIG. 2 shows a perspective view of the main parts of an embodiment of the magnetic recording/reproducing apparatus according to the present invention.

In this embodiment, the rotating magnetic head device 1
includes a fixed drum 2 and a rotating drum 3, each of which is formed into a substantially cylindrical shape, and the rotating drum 3 is driven to rotate at a constant speed by a drum motor 4. The magnetic tape 5 is guided by tape guides 6 and 7 disposed in the tape running path, and is wound around the rotating magnetic head device 1 in a substantially Ω shape at a predetermined angle of inclination, as shown in the figure. The vehicle is driven at a constant speed by means of pinching means such as capstan and pinch rollers. Note that arrow A in FIG. 2 indicates the rotation direction of the rotary drum 3, and arrow B indicates the running direction of the magnetic tape 5. The rotating magnetic head device 1 has four magnetic heads 8A, 8B, 9A, and 9B arranged on the rotating drum 3 as shown in FIG. The above four magnetic heads 8A,
Two magnetic heads 8A out of 8B, 9A, 9B,
8B are fixed to the outer peripheral edge portion of the rotating drum 3 with a positional relationship of about 180° to each other,
Performs video signal recording and video signal playback in normal playback mode. The other two magnetic heads 9A and 9B are located at the outer peripheral edge of the rotary drum 3 at a positional relationship of about 180 degrees to each other, and are connected to each other via electromechanical transducers 10A and 10B such as bimorph plates. It is installed and performs video signal playback in special playback modes such as field still playback, slow playback, and fast playback. Each of the magnetic heads 9A and 9B is constantly subjected to minute vibrations in the direction of the rotation axis of the rotating magnetic head device 1, that is, in the tape width direction of the magnetic tape 5 (in the direction of arrow C in the figure) by electromechanical transducers 10A and 10B. It is given. The electromechanical transducers 10A, 1 are controlled by feedback control so that the reproduced video signal obtained in the special reproduction mode has the maximum signal level.
The micro-vibration drive state of each magnetic head 9A, 9B by 0B is controlled, and an auto-tracking operation is performed so that each magnetic head 9A, 9B correctly traces the recording track TRa (see FIG. 1) of the magnetic tape 5. It's on. Further, in the normal reproduction mode and recording mode, the electromechanical transducer 10
A, 10B connect each magnetic head 9A, 9B to 2~
The magnetic tape 5 is vibrated with a minute amplitude of about 3 μm to generate an air film phenomenon between the magnetic tape 5 and the rotating magnetic head device 1, and the magnetic tape 5 is subjected to minute vibrations, thereby producing a vibration transport effect. Magnetic tape 5 and each magnetic head 8A, 8
This prevents the so-called sticking phenomenon and abrasion damage of B, 9A, and 9B.

In an embodiment configured as described above, the electromechanical transducer 10 is activated during all operating modes: recording mode, normal playback mode, and special playback mode.
Since the magnetic heads 9A and 9B are slightly vibrated by the magnetic heads A and 10B, the magnetic tape 5 and each magnetic head are 8A, 8B, 9A, 9B can be sufficiently reduced, and a special reproduction mode can also be used to eliminate guard band noise etc. using the wobbling method using each magnetic head 9A, 9B given the above-mentioned minute vibrations. Therefore, it is possible to obtain a high-quality reproduced video signal with extremely little amount of noise.

Therefore, according to the present invention, the intended purpose can be fully achieved.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing recording tracks formed on a magnetic tape in a VTR. FIG. 2 is an external perspective view of essential parts showing an embodiment of the present invention.
FIG. 3 is an external perspective view of the rotating drum provided with each magnetic head in the above embodiment. 1... Rotating magnetic head device, 2... Fixed drum, 3... Rotating drum, 4... Drum motor, 5
...Magnetic tape, 8A, 8B... Fixed magnetic head, 9A, 9B... Movable magnetic head, 10A, 1
0B...Electromechanical conversion element.

Claims (1)

[Scope of utility model registration request] A rotating magnetic head having a pair of fixed magnetic heads on a rotating drum used for recording or normal reproduction of signals, and a pair of movable magnetic heads on the rotating drum used for special reproduction of signals supported by electromechanical transducers. A head device is provided, and recording and normal reproduction operations are performed by the pair of fixed magnetic heads while slightly vibrating the pair of movable magnetic heads, and special reproduction operations such as still reproduction are performed by the pair of movable magnetic heads. A magnetic recording and reproducing device characterized in that the movable magnetic head performs a tracking operation using bling.