JP2699546B2 - Magnetic recording / reproducing device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a magnetic recording / reproducing apparatus using a magnetic tape.

2. Description of the Related Art In a device using a magnetic tape such as a VTR, fast forward and rewind operations are frequently performed. At this time, a drive circuit may be mounted on each of the take-up reel and the supply reel in order to shorten the rewind time and reduce noise, and a mechanism that can independently control the start and stop of driving may be used. With such a mechanism, when stopping from the rewinding and fast-forwarding states, tape damage is less likely to occur, and the possibility of such damage is further increasing with the speeding up.Reel control in each operation is extremely difficult. Has become important.

Next, a conventional example is shown in FIG. In FIG. 2, reference numeral 1 denotes a magnetic tape. 2 is a supply side reel motor. Reference numeral 3 denotes a take-up reel motor. Reference numeral 4 denotes a drive circuit for the supply-side reel motor. Reference numeral 5 denotes a drive circuit for the take-up reel motor. Reference numeral 6 denotes a control circuit that can output a drive start command or a stop command for each of the two reel drive circuits independently. Reference numeral 9 denotes a brake drive circuit for applying a brake to both reel motors 2 and 3 in accordance with a designation from the control circuit 6 to stop.

The operation of the conventional reel control circuit configured as described above will be described below.

First, control specifications for stopping from the fast-forward operation will be described. During the fast-forward operation, the magnetic tape 1 is wound on the winding reel motor 3. The supply-side reel motor 2 is controlled so that a slight load is applied so that the magnetic tape 1 does not sag. First, the control circuit 6 outputs a rotation stop command 62 for the take-up reel motor 3 to the reel drive circuit 5, and the drive of the take-up reel motor 3 ends. At the same time or after a certain period of time with the rotation stop command 62, the rotation stop command 61 of the supply side reel motor 2 is transmitted to the reel drive circuit 4.
And the driving of the supply-side reel motor 2 ends. Brake drive command 63 at the same time as rotation stop command 61 or after a fixed time
Is output to stop both reel motors.

In the case of the rewind operation, the same control specifications are obtained. During the rewinding operation, the magnetic tape 1 is wound on the supply-side reel motor 2. The take-up reel motor 3 is controlled so that a slight load is applied so that the magnetic tape 1 does not sag. First, the control circuit 6 outputs a rotation stop command 61 of the supply-side reel motor 2 to the reel drive circuit 4,
The drive of the supply-side reel motor 2 ends. At the same time or after a certain period of time with the rotation stop command 61, a rotation stop command 62 of the take-up reel motor 3 is output to the reel drive circuit 4, and the drive of the take-up reel motor 3 is completed. Simultaneously with or after a certain time after the rotation stop command 62, a brake drive command 63 is output to stop both reel motors. Due to the control specifications as described above, the tape tension in the stopped state may not be constant or may be strong due to the variation in the braking force, which may cause tape damage.

As described above, in the conventional configuration, since the brake drive command is given at the same time or after a certain time after the control of the take-up reel and the supply reel drive circuit, the tape tension in the stopped state due to the variation in the braking force. However, the tension was not constant and the tension was sometimes high, which contributed to the tape damage.

Means for Solving the Problems The present invention detects a rotation speed of each of a reel drive circuit for driving a take-up reel motor and a reel drive circuit for driving a supply-side reel motor, and detects that the rotation speed is equal to or lower than a certain speed. , And a control circuit that can output a drive start command or a stop command for each of the two reel drive circuits independently of each other.

Operation The present invention having the above configuration, the control circuit controls the supply side reel motor so that a little load is applied so as not to sag the tape, and when stopping from the fast-forward or rewind state of the tape, After outputting the drive stop command of the take-up reel motor, the take-up speed is gradually decreased by the load of the supply-side reel motor, and when the output from the rotation speed detection circuit is received, the supply side The above problem can be solved by stopping the driving of the reel motor.

Embodiment An embodiment of the present invention is shown in FIG. In FIG. 1, 1
Is a magnetic tape. 2 is a supply side reel motor.
Reference numeral 3 denotes a take-up reel motor. Reference numeral 4 denotes a drive circuit for the supply-side reel motor. Reference numeral 5 denotes a drive circuit for the take-up reel motor. Reference numeral 6 denotes a control circuit that can output a drive start command or a stop command for each of the two reel drive circuits independently. Reference numeral 7 denotes a rotation speed detection circuit for detecting a rotation speed by obtaining a rotation pulse electrically, magnetically or mechanically from a supply-side reel motor. Reference numeral 8 denotes a rotation speed detection circuit for detecting a rotation speed by obtaining a rotation pulse electrically, magnetically, or mechanically from a take-up reel motor. Reference numeral 9 denotes a brake drive circuit for applying a brake to both reel motors 2 and 3 in accordance with a command from the control rotation 6 to stop.

The operation of the reel control circuit configured as described above will be described below.

First, control specifications for stopping from the fast-forward operation will be described. During the fast-forward operation, the magnetic tape 1 is wound on the winding reel motor 3. The supply-side reel motor 2 is controlled so that a slight load is applied so that the magnetic tape 1 does not sag. First, the control circuit 6 outputs a rotation stop command 62 for the take-up reel motor 3 to the reel drive circuit 5, and the drive of the take-up reel motor 3 ends. The magnetic tape 1 is wound by inertia, and the winding speed gradually decreases due to the load of the supply-side reel motor 2. At this time, the rotation speed detection circuit 7 or 8
Detects the rotation speed of each of the reel motors 2 and 3, and outputs an output 71 or 81 when the rotation speed becomes lower than a certain speed. When the control circuit 6 detects the command 71 or 81,
Immediately, the rotation stop command 61 of the supply-side reel motor 2 is output to the reel drive circuit 4, and the drive of the supply-side reel motor 2 is completed. Then, a brake drive command 63 is output at the same time as the rotation stop command 61 or after a fixed time, to stop both reel motors.

In the case of the rewind operation, the same control specifications are obtained. During the rewinding operation, the magnetic tape 1 is wound on the supply-side reel motor 2. The take-up reel motor 3 is controlled so that a slight load is applied so that the magnetic tape 1 does not sag. First, the control circuit 6 outputs a rotation stop command 61 of the supply-side reel motor 2 to the reel drive circuit 4,
The drive of the supply-side reel motor 2 ends. The magnetic tape 1
The winding is performed by inertia, and the winding speed gradually decreases due to the load of the winding-side reel motor 3. At this time,
The rotation speed detection circuit 7 or 8 detects the rotation speed of each of the reel motors 2 and 3, and outputs an output 71 or 81 when the rotation speed becomes equal to or lower than a certain speed. In the control circuit 6,
As soon as the command 71 or 81 is detected, a rotation stop command 62 of the take-up reel motor 3 is output to the reel drive circuit 4 and the drive of the take-up reel motor 3 is completed. Then, at the same time as the rotation stop command 62 or after a fixed time, the brake drive command 63
Is output to stop both reel motors.

By controlling in this manner, tape damage in a stopped state does not become constant or becomes strong due to a variation in braking force, and tape damage can be prevented.

As described above, according to the present invention, the rotation speeds of the reel drive circuit that drives the take-up reel motor and the reel drive circuit that drives the supply-side reel motor are detected, and the fact that the rotation speeds are equal to or less than the certain speed is detected. A control circuit that can output a drive start command or a stop command for each of the two reel drive circuits independently of each other, and the control circuit prevents the supply-side reel motor from sagging the tape. Controlling to apply a little load, and when stopping from the fast-forward or rewinding state of the tape, after outputting the drive stop command of the winding-side reel motor, the winding speed is gradually increased by the load of the supply-side reel motor. The drive of the supply reel motor is stopped when there is an output from the rotation speed detection circuit, so that the Can prevent the occurrence of loop damage.

[Brief description of the drawings]

FIG. 1 is a block diagram of a reel control circuit in an embodiment of the magnetic recording / reproducing apparatus of the present invention, and FIG. 2 is a block diagram of a conventional reel control circuit. 1 ... magnetic tape, 2 ... supply side reel motor, 3 ...
Take-up reel motor, 4 ... Drive circuit for supply-side reel motor, 5 ... Drive circuit for take-up reel motor, 6 ...
... Control circuit, 7 ... Rotation speed detection circuit, 8 ... Rotation speed detection circuit, 9 ... Brake drive circuit

Claims (1)

(57) [Claims] 1. A reel drive circuit for driving a take-up reel motor and a reel drive circuit for driving a supply-side reel motor, and a rotational speed capable of detecting the respective rotational speeds and detecting that the speed has become equal to or lower than a predetermined speed. A detection circuit and a control circuit that can output a drive start command or a stop command for each of the two reel drive circuits independently of each other are provided, and the control circuit applies a little load so that the supply reel motor does not sag the tape. When the tape is fast-forwarded or stopped from the rewind state, after outputting a drive stop command of the winding-side reel motor, the winding speed is gradually reduced by the load of the supply-side reel motor. And a step of stopping the drive of the supply-side reel motor when there is an output from the rotation speed detection circuit.