JPH05314602A - Rotary drum - Google Patents

Abstract

PURPOSE:To enable stable recording and reproduction of high quality by making fluid force generated between a magnetic head and a magnetic tape uniform. CONSTITUTION:The rotational part 11 of a rotary drum has the magnetic head 1 attached in a window 14 and rotates. The rotational part 11 is rotated and supported by a fixed part 12. An electromechanical converting part 16 and a sliding part 17 are joined to a fixed part 12 side so as to fill up a gap between the boundary surfaces of the rotational part 11 and the fixed part 12. The electromechanical converting part 16 is made of piezoelectric material, electrostrictive material or the like and vibrates an ultrasonic frequency by applying an electric signal from the outside. The sliding part 17 made of wear resistance material is pressesed and brought into contact with the boundary surface of the rotational part 11 side and transmits the ultrasonic frequency of the electromechanical converting part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary drum used in a magnetic recording / reproducing apparatus.

[0002]

2. Description of the Related Art As shown in FIG. 2, a conventional rotating drum has a rotating portion 21 to which a magnetic head 23 is attached and which rotates.
And a fixed portion 22 for rotating and supporting the rotating portion.

Here, the magnetic head 23 is fixed so as to protrude from the window 24 provided on the surface of the rotating portion 21 by a few tens of microns, and the magnetic head 25 is wound around the rotating drum in a helical shape and runs. To record and reproduce the information signal.

By the way, the magnetic head 23 and the magnetic tape 2
Fluid force due to the flow of air between (5)
However, the fluid force is made constant by letting air escape through the window 24.

[0005]

In the conventional rotary drum described above, a window is provided to allow air to escape so that the fluid force generated between the magnetic head and the magnetic tape becomes constant. However, the rotating portion 21 and the fixed portion 22
Since there is a gap 26 at the boundary portion between and, and it is necessary to provide the window 24 near this gap, it is difficult to make the fluid force uniform due to the influence of the gap, and stable recording / reproduction cannot be performed. There is a problem.

An object of the present invention is to provide a rotary drum capable of removing the influence of the gap between the rotating portion and the fixed portion to make the fluid force uniform and capable of stable recording and reproduction of high quality.

[0007]

The rotary drum of the present invention comprises:
A rotating part to which the magnetic head is attached and rotates, a fixed part that rotatably supports the rotating part, and an electromechanical conversion part that is provided on the fixed part side of the boundary end surface between the rotating part and the fixed part and vibrates minutely. And a sliding portion that is in pressure contact with the boundary end surface of the rotating portion and transmits the ultrasonic vibration. In addition, the electromechanical conversion unit is configured to vibrate ultrasonically when the rotating unit rotates and stop ultrasonic vibration when the rotating unit stops rotating.

[0008]

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

FIG. 1 is a diagram showing an embodiment of the present invention.
(A) is a perspective view, (b) is sectional drawing seen from the AA cutting line.

The rotary drum is composed of a rotary portion 11 in which a magnetic head 13 is attached to a window 14 for rotation, and a fixed portion 12 for rotating and supporting the rotary portion. The rotary drum is helically wound on the rotary drum. Information signals are recorded / reproduced on / from the magnetic tape 15 running while being run over.

By the way, the electromechanical conversion portion 16 and the sliding portion 17 are joined to the fixed portion 12 side so as to fill the gap at the boundary end surface between the rotating portion 11 and the fixed portion 12. Here, the electromechanical conversion unit 16 is made of a piezoelectric material, an electrostrictive material, or the like, and an electric signal is externally applied to cause a slight vibration. Further, the sliding portion 17 is made of a wear resistant material and is pressed against the boundary end surface on the rotating portion 11 side to transmit the vibration of the electromechanical conversion portion.

As is well known, when ultrasonic vibration is applied to one of two pressure-contacted objects, the pressure-contact surface is slightly displaced to eliminate friction. Therefore, when rotating the rotating part 11, by applying an electric signal of 20 kHz or more to the electromechanical conversion part 16 to cause ultrasonic vibration, friction with the fixed part is eliminated, and the rotating part freely rotates. The rotating unit 1
When the rotation of No. 1 is stopped, the excitation of the electromechanical conversion unit is stopped so that the rotation can be rapidly stopped by the pressure contact force.

By doing so, the gap between the rotating portion 11 and the fixed portion 12 is in the unit of micron, and the air fluid is not disturbed, so that the fluid force generated between the magnetic head and the magnetic tape becomes uniform, Therefore, stable recording / reproducing is possible.

[0014]

As described above, according to the present invention, the electromechanical conversion section for ultrasonic vibration and the sliding section for transmitting ultrasonic vibration to the rotary section are provided in the gap between the rotary section and the fixed section. By making the gap small, the turbulence of the air fluid generated by the gap can be removed, the fluid force generated between the magnetic head and the magnetic tape can be made uniform, and stable high-quality recording and reproduction can be performed.

[Brief description of drawings]

1A and 1B are views showing an embodiment of the present invention, in which FIG. 1A is a perspective view and FIG. 1B is a sectional view taken along the line AA.

FIG. 2 is a perspective view showing an example of a conventional rotary drum.

[Explanation of symbols]

 13 magnetic head 11 rotating part 12 fixed part 15 magnetic tape 16 electromechanical conversion part 17 sliding part

Claims (2)

[Claims] 1. A rotary unit, to which a magnetic head is attached and rotates, a fixed unit that rotatably supports the rotary unit, and a fixed end of a boundary end face between the rotary unit and the fixed unit, which is provided with a small vibration. A rotary drum, comprising: an electromechanical conversion unit; and a sliding unit that is in pressure contact with a boundary end surface of the rotating unit to transmit the ultrasonic vibration. 2. The rotary drum according to claim 1, wherein the electromechanical conversion unit vibrates ultrasonically when the rotary unit rotates and stops the ultrasonic vibration when the rotary unit stops rotating. Rotating drum.