JPH02195556A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To reduce damage to a magnetic tape caused by tensile force at the time of stopping or starting a rotating head cylinder by rotating a motor for driving a capstan in a direction where the magnetic tape is loosened for a specified time. CONSTITUTION:In the case of stopping the rotating head cylinder 1, the motor for driving the capstan 2 is driven in the direction where the magnetic tape 3 is loosened for the specified time to form the looseness of the magnetic tape 3 on the outgoing side of the cylinder 1 at a point of time when the revolving speed of the rotating head cylinder 1 is lowered and air film is not formed. In the case of starting the rotating head cylinder, the motor for driving the capstan 2 is rotated in the direction where the magnetic tape 3 is loosened for the specified time before starting it. Thus, the damage to the magnetic tape caused by the tensile force at the time of stopping or starting the rotating head cylinder is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a magnetic recording/reproducing device, and in particular to preventing damage to a magnetic tape caused by tension.

2. Description of the Related Art A conventional magnetic recording/reproducing apparatus (hereinafter simply referred to as a VTR) will be described below with reference to the drawings. Figure 3 is a schematic plan view of a conventional VTR when loading is complete;
FIG. 4 shows a front view of the rotary head cylinder near the magnetic tape separation point (hereinafter referred to as the cylinder exit side) in the same VTR.

3 and 4, 21 is a rotating head cylinder, and the upper cylinder on the rotating side where the magnetic head 24 is located.
22 and a lower cylinder 23 on the fixed side. 25 is a magnetic tape that is wound around the rotary head cylinder 21 at a predetermined angle, and 26 is a separation point of the magnetic tape 25.

The operations of releasing the tension on the magnetic tape 25 and stopping the rotation of the upper cylinder 22 in the VTR configured as described above will be described below. First, when stopping the rotation of the upper cylinder 22, as shown in FIG. 3, the tension on the magnetic tape 25 is released from the stopped state, and then the voltage driving the upper cylinder 22 is released. By doing so, the tension on the magnetic tape 25 is released and the upper cylinder 2
A series of operations of stopping the rotation in step 2 are being performed. Next, when the upper cylinder 22 is rotated and tension is applied to the magnetic tape 25 to return it to a running state, tension is applied to the magnetic tape 25 after the upper cylinder 22 is activated. When the upper cylinder 22 is rotating, as shown in FIG. 4, the magnetic tape 25 is in contact with the lower cylinder 23 on the exit side of the cylinder, so the magnetic tape 25 is levitated by the air film. The rotating head cylinder 21 of the magnetic tape 25 has little effect.
The contact pressure is high.

Problem to be Solved by the Invention However, according to the above conventional configuration, when the tension of the magnetic tape 25 is released, on the supply reel side (hereinafter referred to as the cylinder entry side) of the rotary head cylinder 21, the upper cylinder 22 Since the area of contact between the magnetic tape 25 and the magnetic tape 25 is relatively large, as shown in FIG.
There was a problem in that the contact pressure with the magnetic tape 1 was not sufficiently lowered, and therefore the magnetic tape 25 was damaged due to tension when the rotary head cylinder 21 was stopped or started.

Therefore, an object of the present invention is to provide a magnetic recording/reproducing device that can solve the above problems.

Means for Solving the Problems In order to solve the above problems, the magnetic recording and reproducing apparatus of the present invention includes a rotary head cylinder having a magnetic head, a capstan driving motor, and a rotating head cylinder for detecting the number of rotations of the rotary head cylinder. When the number of revolutions of the rotary head cylinder falls below a predetermined value after the rotation of the take-up and supply reels has stopped, the supply reel is fixed by a brake, and the capstan drive motor is magnetized. A control circuit is provided to rotate the tape for a predetermined period of time in the direction in which the tape becomes slack. In addition, in the above configuration, when the magnetic tape and the rotating head cylinder are stopped, the control circuit releases the fixation of the take-up reel and causes the capstan drive motor to loosen the magnetic tape before starting the rotating head cylinder. It is configured to rotate in the direction for a predetermined period of time.

Operation In the above configuration, when the rotating head cylinder is stopped, the capstan driving motor is driven for a predetermined period of time in the direction in which the magnetic tape is loosened when the rotational speed of the rotating head cylinder decreases and no air film is formed. Because the magnetic tape is slack on the cylinder exit side,
Damage to the magnetic tape caused by tension immediately before the rotating head cylinder stops rotating can be reduced.

Furthermore, when starting the rotating head cylinder, the capstan drive motor is rotated for a predetermined period of time in a direction that loosens the magnetic tape before starting the rotating head cylinder, which prevents damage to the magnetic tape caused by tension immediately after starting the rotating head cylinder. It is possible to reduce the

EXAMPLE An example of the present invention will be described below with reference to FIGS. 1 and 2.

FIGS. 1(a) and 2(a) show schematic plan views of the main parts of the magnetic recording/reproducing apparatus. The magnetic recording and reproducing apparatus according to this embodiment mainly includes a rotating head cylinder 1 having a magnetic head, a brake for fixing the take-up and supply reels (not shown), and a driving motor for the capstan 2 (not shown). ) and a rotation speed detection circuit (not shown) for detecting the rotation speed of the rotary head cylinder 1, and after the rotation of the take-up and supply reels is stopped, the rotation speed of the rotary head cylinder 1 is set to a set value ( A control circuit (not shown) is provided for fixing the supply reel and rotating the capstan driving motor for a predetermined period of time in the direction in which the magnetic tape 3 is loosened when the magnetic tape 3 is below a predetermined value. Furthermore, this control circuit controls the rotary head cylinder 1 when the magnetic tape 3 and the rotary head cylinder 1 are stopped.
When the magnetic tape 3 is started, the fixation of the take-up reel is released and the capstan driving motor is rotated for a predetermined period of time in a direction in which the magnetic tape 3 is loosened.

Next, the operation will be explained.

When stopping the rotating head cylinder 1, first stop the rotation of the take-up and supply reels to stop the magnetic tape 3 (in this state, no tension is applied to the magnetic tape 3), then start the rotating head cylinder 1. stop the rotation. When the rotation speed detection circuit determines that the rotation speed of the rotary head cylinder 1 has become below the set value, the control circuit controls the direction in which the magnetic tape 3 is loosened ( A capstan driving motor is rotated on the supply reel side). In this way, the first
As shown in Figure (a), the magnetic tape 3 is placed on the cylinder exit side.
Since the slack is formed, it is possible to reduce damage to the magnetic tape 3 due to tension immediately before the rotation of the rotary head cylinder 1 stops.

When starting the rotary head cylinder 1, first the rotary head cylinder 1 is stopped and the magnetic tape 3 is turned on.
With the supply reel fixed, the take-up reel is released and the capstan 2 is rotated for a predetermined period of time in the direction in which the magnetic tape 3 is loosened (towards the supply reel) (see Fig. 2 (b).
)reference). Then, as shown in FIG. 2(a), the magnetic tape 3 becomes loose on the exit side of the cylinder.

Next, in this state, start the rotating head cylinder 1,
When the number of revolutions of the rotary head cylinder 1 exceeds a set value, tension may be applied to the magnetic tape 3 to enable it to run. In this way, the magnetic tape 3 can be loosened on the cylinder exit side immediately before the rotary head cylinder 1 is started, thereby reducing damage to the magnetic tape 3 due to tension immediately after the rotary head cylinder 1 is started. be able to.

Effects of the Invention As described above, according to the configuration of the present invention, when stopping the rotary head cylinder, when the number of revolutions of the rotary head cylinder falls below a predetermined value, the supply reel is fixed and the capstan driving motor is magnetically activated. The direction in which the tape loosens (
Since a control circuit for rotating the magnetic tape for a predetermined period of time is provided on the supply reel side, it is possible to reduce damage caused to the magnetic tape due to tension just before the rotating head cylinder stops rotating. In addition, when the above-mentioned control circuit starts the rotating head cylinder, the take-up reel is released from the fixation before starting, and the capstan drive motor is rotated for a predetermined period of time in the direction in which the magnetic tape is loosened (towards the supply reel). By doing so, it is possible to reduce damage to the magnetic tape due to tension immediately after the rotary head cylinder is started.

[Brief explanation of the drawing]

FIGS. 1 and 2 show a magnetic recording and reproducing apparatus according to an embodiment of the present invention, and FIGS.
a) is a schematic plan view of the main part showing a state in which the magnetic tape is loosened;
Figures 1(b) and 2(b) are graphs showing the relationship between the number of revolutions of the rotary head cylinder and the feed amount of the magnetic tape, and Figures 3 to 5 show conventional examples; 4 is a front view of the cylinder exit side, and FIG. 5 is a plan view of the rotary head cylinder when the tension on the magnetic tape is released. 1... Rotating head cylinder 2... Capstan, 3... Magnetic tape.

Claims (1)

[Scope of Claims] 1. A rotary head cylinder having a magnetic head, a capstan driving motor, and a rotation speed detection circuit for detecting the rotation speed of the rotary head cylinder; The magnetic head is equipped with a control circuit that uses a brake to fix the supply reel when the rotational speed of the rotary head cylinder falls below a predetermined value after the rotation has stopped, and also rotates the capstan drive motor for a predetermined period of time in a direction in which the magnetic tape is loosened. Recording and playback device. 2. When the control circuit is in a state where the magnetic tape and the rotating head cylinder are stopped, and before starting the rotating head cylinder, release the fixation of the take-up reel and move the capstan drive motor in the direction in which the magnetic tape is loosened for a predetermined period of time. The magnetic recording/reproducing device according to claim 1, configured to rotate.