JPH02287958A - Recording and reproducing device - Google Patents

Abstract

PURPOSE:To control and prevent the transverse vibration of a tape by giving lower negative pressure than air pressure to the air suction hole of a guide which is separated from the tape. CONSTITUTION:Air sucked by a negative pressure generation means 18 is generated to the suction ports 14 and 15 of the guide 13 through a negative pressure supplying pipe 17. Thus, the negative pressure is generated near the suction ports 14 and 15 and suction force acts on the tape 16. Then, the tape is attracted in the direction of the guide 13. The tape 16 is attracted in the direction of the guide 13 by a displacement quantity that tensile force and the suction force which are received by the tape 16 are well-balanced. In such a way, the transverse vibration of the tape is prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a recording/reproducing apparatus in which a tape is guided and run by a guide.

As is well known in the art, in recording and reproducing devices that run a tape by guiding it through guides, as the running system becomes more complex and the distance between the guides increases, transverse vibrations tend to occur in the tape stretched between them. . In addition, when a pair of guides are not parallel to each other and have a three-dimensional twist, uneven tension tends to occur in the tape width direction, resulting in a so-called single tension state, which further induces tape lateral vibration. It becomes easier.

Such tape transverse vibration is converted into tape longitudinal vibration by reflection and absorption by guides, etc., and in VTRs, etc., it ultimately becomes a time u (ff axis error), so-called audio signal wow platter, video signal jitter.

As a method of reducing such vibrations, a method has already been proposed in which a guide is installed at a distance of several 11 meters from the tape.

A conventional example will be explained below with reference to FIG. In FIG. 5, 21 and 22 indicate tape guides that guide the tape, 24 the tape stretched between them, and 23 the tape 2.
4, the guide is placed parallel to the tape 24 and spaced apart from it by a distance of approximately several μm.

Next, its operation will be explained. The minute transverse vibrations generated in the tape 24 cause a change in the distance between the guide 23 and the tape 24 of the order of number/Jm, causing a change in the distance between the guide 23 and the tape 24.
This causes a change in pressure in the air existing between the tape 24 and the tape 24. Since air has viscosity in response to this change in pressure, it generates a force opposing the displacement of the vibration of the tape 24 as a reaction. This is the so-called "air damping effect."

Transverse vibrations are thus damped.

Problems to be Solved by the Invention However, such a guide 23 has the following problems.

(7) The distance range between the tape 24 and the guide, which is effective in attenuating lateral vibration, is as small as several meters per meter, making adjustment and installation difficult.

(a) Uneven distribution of tension in the tape 24 in the tape width direction;
When there is so-called overhang, sufficient damping of tape lateral vibration cannot be obtained.

The present invention has a sufficient vibration damping effect even when the tension of the tape is uneven in the width direction, and the setting range between the tape and the guide is increased to several times, making installation and adjustment easy. The purpose is to

Means for Solving the Problems To achieve this object, the recording and reproducing apparatus of the present invention includes a guide that is spaced apart from the tape at a predetermined distance and has an air intake port on a surface facing the tape; and negative pressure generating means for supplying negative pressure to the guide so as to apply a negative pressure lower than atmospheric pressure to the mouth.

Function: With this configuration, suction force is applied to the tape stretched between a pair of tape guides by the guide having an air suction port installed between the tape guides, so that the tape can be pulled out in a non-contact manner. This gives a restraining force to the tape and prevents lateral vibrations occurring in the tape.

Also, the size of the negative pressure, the size and shape of the inlet.

By adjusting the number, arrangement, etc., the range of the suction force on the tape can be increased to several heads.

Furthermore, even when the tape tension is uneven in the tape width direction (unilateral tension state), the displacement due to the suction force from the suction port is large in areas where the tape tension is weak, and the displacement due to the suction force from the suction port is large in areas where the tape tension is strong. Balance is achieved at a position where the unevenness of the tension in the width direction of the tape is reduced by reducing the displacement due to the suction force of υ. Therefore, the vibration damping force is increased by limiting and attenuating tape lateral vibration throughout the entire width of the tape, instead of limiting and damping the lateral vibration of the tape only in areas where the tape tension is high or low in the tape width direction.

As described above, by applying a suction force due to negative pressure to the tape, installation and adjustment are facilitated, and a sufficient vibration effect can be achieved even when the tape has uneven tension.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a recording/reproducing apparatus according to a first embodiment of the present invention, in which a guide having an air intake port is installed between a pair of guides to prevent and reduce lateral vibration of the tape.

In FIG. 1, reference numerals 11 and 12 are guides for guiding the tape running.

13 is a guide having an air suction port, 14 is a circular suction port, 16 is a null-shaped suction port, 16 is a tape, 1
7 is a negative pressure supply pipe, and 18 is a negative pressure generating means.

The operation of the guide having the suction port configured as described above will be described below.

First, a negative pressure generating means 18 such as an air pump is connected to the internal cavity of the guide 13 having an inlet through a negative pressure supply pipe 17, so that a constant amount of air is sucked into the inlet 14 and 15 at all times. .

Due to this air suction, negative pressure is generated near the suction hole 14.15, and a suction force acts on the tape 16 running facing the guide 13 having the suction port, and the tape 16 is pulled toward the guide 13 having a . At this time, since the tape 16 is controlled by a constant tension, the tape 16 is displaced by the amount of displacement that matches the resultant force of the tension and the suction force.
6 is pulled toward the guide 13 having the suction port,
You can interact without contact.

As described above, according to this embodiment, negative pressure is generated in the suction ports 14 and 15 of the guide 13 having the suction ports in response to the transverse vibration of the tape 16, and air flows from the suction ports 14 and 15 into the internal cavity. By constantly flowing in, the tape 16 facing the front surface of the suction ports 14, 1f5 is attracted, and by constantly exerting a constant restraint force, it is possible to prevent the tape 16 from generating lateral vibration.

Furthermore, since the lateral displacement of the tape is determined by the balance between the suction force due to the negative air pressure generated by the suction ports 14 and 15 and the tension of the tape, in the case where the tension is uneven in the width direction of the tape, The area of weak tension is largely displaced, and the area of strong tension is displaced small, which balances the suction force and, as a result, reduces uneven tension in the tape width direction.

Furthermore, the suction force is applied to each part irrespective of the unevenness of the tape tension, and the force for allocating tape lateral vibrations is applied to the entire tape width direction. Therefore, even when the tension is uneven in the tape width direction, sufficient effectiveness is exhibited.

A second embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows a second embodiment of the present invention in which a guide having a suction port is used to reduce lateral vibration of a tape caused by a head attached to a rotating drum.

In the figure, 31 is a guide for guiding tape running, 33 is a guide having a suction port, 36 is a rotating drum, and 33 is a head attached to the drum.

Further, FIG. 3 is a perspective view of the guide 32 having the suction port as seen from the front direction. 4a to 4e are circular suction ports, and 42 is a slit-shaped suction port.

The effects of the guide having the suction port configured as described above will be explained below.

In FIG. 2, the drum 36 rotates, and the tape 34 wound around the drum 36 by the head 33 attached thereto is struck at the point where the head 33 separates from the tape 34, generating transverse waves.

This transverse wave is transmitted to the guide 31 if there is no guide 32 having an inlet. This transverse wave is attenuated by the guide 32Vc having an inlet. Waves that form a solitary wave as shown in the figure will be attenuated unless absorbed by a system with an impedance sufficiently smaller than the characteristic impedance of the wave propagation medium (in this case, the impedance of the transverse wave of the tape). The waves are reflected, and the waves repeat back and forth between the guide 31 and the drum 36.

A guide 32 having an inlet for such transverse waves K
By generating a restraining force against the tape by using negative air pressure, and gradually decreasing the distance between the tape 34 and the guide 32 having the suction port, the restraining force against transverse waves is gradually increased. By lowering the upper impedance, a vibration damping system is constructed in which there is no reflection of transverse waves.

This uses the suction force created by negative air pressure, so
Even when there is a distance between the tape 34 and the guide 32 having the suction port, the vibration damping effect due to air flow can be obtained.

Note that the guide with the suction port has the fourth section as shown in Fig. 4.
It may be a cylindrical guide as shown in Figure A, a flat guide as shown in Figure 4B, or a semicircular guide as shown in Figure 4. Furthermore, the shape of the inlet also has a fourth effect.
It may be a circular suction port as shown in Figure A, a slit-shaped suction port as shown in Figure 4C, or a circular suction port as shown in the fourth diagram. A mixture of circular, circular, and slit-shaped intake ports may also be used.

Effects of the Invention As described above, the present invention counteracts the transverse vibrations generated in the tape by installing a guide having an air suction port in a state separated from the tape, and utilizing the negative pressure of the air generated at the suction port. This dampens and dampens tape lateral vibration. Since negative air pressure is used, the set distance between the tape and the guide can be set as large as several heads, and in order to apply a restraining force to the tape due to the balance between the negative pressure and the tape tension, it is possible to Even when there is unevenness in the tension, sufficient restraining force is exerted over the entire width of the tape, and its practical effects are great.

[Brief explanation of drawings]

FIG. 1 is a perspective view, top view, and cross-sectional view of a case where a guide having an air intake port is provided between a pair of tape guides according to a first embodiment of the present invention, and FIG. 2 is a diagram showing a second embodiment of the present invention. FIG. 3 is a perspective view of the guide having an air suction port in the second embodiment, and FIG. FIG. 6 is a perspective view and a top view showing the configuration of a conventional tape guide. 11.12...Tape guide, 13...
・Guide, 14...Circular suction port, 16...
... Slit-shaped inlet, 16 ... Tape, 17 ... Negative pressure supply pipe, 18 ...
・Negative pressure generating means, 32.41...Guide. Name of agent: Patent attorney Shigetaka Awano and 1 other person 1st
Figure 31- Tape no id i-m= YOλ口! It has idΩ-e+o1. . 4th Figure Ditch 3 K 4a~4e---@ ＾ 0 4I-Inlet entrance 3 no Ido-Slit town-shaped Yo λ mouth (AJ 11d2---Tape guide 13-Inlet O mo available) Tape guide 14- Inlet port I5- Slit type Oj slot

Claims (1)

[Claims] a guide that is spaced a predetermined distance from the tape and has an air intake port on a surface facing the tape; and a negative pressure that supplies negative pressure to the guide so as to apply a negative pressure lower than atmospheric pressure to the air intake port. 1. A recording and reproducing device comprising a generating means.