JPH0887788A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE: To enable stable loose tape control without variation in a tape slackening amt. at the time of loosening the tape even when the tape winding diameter becomes different. CONSTITUTION: The number of pulses of a signal of an FG 8 of a take-up reel 3 is counted in gradually lowering rotating torque of the take-up reel 3 after fixing a supply reel 4 by a brake 13. Then, when the count value becomes a prescribed number of pulses set previously in accordance with a tape winding diameter concerned, the take-up reel 3 is braked.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art A conventional magnetic recording / reproducing apparatus will be described below with reference to the drawings.

FIG. 3 is a block diagram showing the structure of a conventional magnetic recording / reproducing apparatus. In FIG. 3, the posts 17, 18
The magnetic tape 1 wound around the drum 2 by the
It is sent out from the reel 4, is transported by the capstan motor 5 and the pinch roller 27, and is taken up by the winding reel 3. A movable post 15 connected to a spring 16 is provided between the capstan motor 5 and the take-up reel 3 to absorb the tape slack at the time of mode transition. Rotational force is applied to the supply reel 4 by the reel motor 7 and rotational force is applied to the take-up reel 3 by the reel motor 6.

The rotation speeds of the reel motors 6, 7 and the capstan motor 5 are detected by frequency signal generators (hereinafter referred to as FG) 8, 9, 10 respectively, and the waveform shaping circuit 2 is detected.
After waveform shaping at 0, 21, and 26, it is applied to the reel control circuit 24 as an FG signal. The reel control circuit 24 calculates the winding diameter of the tape wound on the take-up reel 3 and the supply reel 4 from these three FG signals, and through the drive circuits 19 and 22 so as to generate a torque corresponding to the winding diameter. The reel motors 6 and 7 are controlled. The loosening control circuit 25 is supplied with a loosening command signal a for loosening the magnetic tape as an input, and a brake solenoid control command signal f,
g, the pinch solenoid control command signal h is output.

If the magnetic tape 1 is left for a long time while the magnetic tape 1 is stopped and the tension of the magnetic tape 1 is applied to the drum 2, the magnetic tape may be scratched or the magnetic head mounted on the drum 2 may be clogged. After a certain period of time, loosen the magnetic tape and set the tension to 0 g.
You are in the losing mode.

FIG. 4 is a timing chart showing the operation of the conventional magnetic recording / reproducing apparatus when shifting to the losing mode. 4, a, e, d, f, g, and h indicate the waveforms of the signals indicated by the same symbols in FIG. 3, respectively. As shown in FIG. 4, the loosening command signal a enters the losing mode at the HIGH level, and the losing mode is released at the LOW level. The control signal e of the reel motor 7 and the control signal d of the reel motor 6 are analog signals that are proportional to the torque generated by the reel motor, and become 0V in the losing mode and the motor torque becomes 0. The brake solenoid control command f becomes the HIGH level after a certain period of time after the torque of the reel motors 6 and 7 becomes zero. The drive circuit 2 is driven at the timing when it becomes the HIGH level.
The brake solenoid 12 is operated via 9 to bring the brake pad 11 of the reel brake into contact with the reel motor 6 for braking. The brake solenoid control command g becomes HIGH level at the same timing as the brake solenoid control command f, the brake solenoid 14 is operated via the drive circuit 23, and the reel motor 7 is braked by the brake pad 13 of the reel brake. ing. The pinch solenoid control signal h operates the pinch solenoid 28 via the drive circuit 30 at the timing when the pinch solenoid 27 becomes low level, and the pinch roller 27 is removed from the capstan motor 5. As described above, after the torque of the reel motors 6 and 7 is set to 0, the springs 16 connected to the movable posts 15 are extended by allowing a certain period of time until the brakes 11 and 13 brake the reel motors 6 and 7. I put it in the loosening after setting the tape tension to 0g.

[0007]

In such a conventional magnetic recording / reproducing apparatus, the magnetic tape from the reel by the force of the spring 16 depends on the winding diameter of the magnetic tape wound on the take-up reel or the supply reel. Since the pull-out force is different, the amount of tape looseness when shifting to the loosening mode varies, the tension does not completely reach 0 g, and conversely, there is a problem that the tape sags due to excessive looseness. This tendency becomes remarkable especially when the tape running system has a movable post with a spring.

An object of the present invention is to solve the above problems and to provide a magnetic recording / reproducing apparatus in which variations in the amount of tape loosening due to the winding diameter are suppressed.

[0009]

In order to solve the above problems, the present invention provides first and second reel motors and first and second reels for braking the first and second reel motors. A brake, a frequency signal generator for generating a signal of a frequency proportional to the rotation speed of the first reel motor, a winding diameter detecting means for detecting the winding diameter of the magnetic tape wound on the first reel, and a loosening command. A control means for inputting a signal and controlling the torque of the first reel motor and the operation of the first reel brake is provided.

Further, a movable post that moves according to the tension of the magnetic tape is provided.

[0011]

With the above means, the control means reduces the torque of the first reel motor after braking the second reel motor and reduces the output signal of the frequency signal generator when the losing command signal is input. Is counted, and when the count value reaches a value set by the winding diameter, the first reel motor is braked to perform the loosing, so that even when the winding diameter of the magnetic tape is different, There is no variation in the looseness of the magnetic tape, and stable loosening can be performed.

Further, the control means can prevent the magnetic tape from being excessively loosened by gradually reducing the torque of the first reel motor.

Further, when the torque becomes zero, the torque in the opposite direction is gradually increased and the magnetic tape is fed out, whereby sufficient loosing can be performed.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic recording / reproducing apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a magnetic recording / reproducing apparatus according to an embodiment of the present invention. 1, the same components as those in FIG. 3 are designated by the same reference numerals. As shown in FIG. 1, the magnetic tape 1 wound around the drum 2 by the posts 17 and 18 is sent out from the supply reel 4, is transferred by the capstan motor 5 and the pinch roller 27, and is transferred to the winding reel 3. It is taken away. A movable post 15 connected to a spring 16 is provided between the capstan motor 5 and the take-up reel 3 to absorb the tape slack at the time of mode transition. Rotational force is applied to the supply reel 4 by the reel motor 7 and rotational force is applied to the take-up reel 3 by the reel motor 6.

The rotation speeds of the reel motors 6, 7 and the capstan motor 5 are detected by the FGs 8, 9, 10 respectively, and after the waveform shaping by the waveform shaping circuits 20, 21, 26, the F
It is applied to the reel control circuit 24 as a G signal. The reel control circuit 24 detects the winding diameters of the tapes wound on the take-up reel 3 and the supply reel 4 by calculating from these three FG signals, and the drive circuits 19 and 22 so that the torques corresponding to them are generated. The reel motors 6 and 7 are controlled via. The loosening control circuit 25 includes a loosening command signal a for loosening the magnetic tape, an FG signal c from the FG8,
The winding diameter information b of the tape wound on the take-up reel 3 is added as an input, and the brake solenoid control command signal f,
g, the pinch solenoid control command signal h is output.

If the magnetic tape 1 is stopped for a long time with the magnetic tape 1 being tensioned on the drum 2 while the magnetic tape 1 is stopped, the magnetic tape may be scratched or the magnetic head mounted on the drum 2 may be clogged. After a certain period of time, loosen the magnetic tape and set the tension to 0 g.
You are in the losing mode.

FIG. 2 is a timing chart showing the operation of the magnetic recording / reproducing apparatus of the present invention when shifting to the losing mode. 2, a, e, d, f, g, and h represent the waveforms of the signals indicated by the same symbols in FIG. 1, respectively. As shown in FIG. 2, the loosening command signal a enters the losing mode at the HIGH level, and the loosening mode is released at the LOW level. The control signal e of the reel motor 7 is an analog signal that is proportional to the generated torque, and becomes 0V when entering the losing mode, and the torque of the reel motor 7 becomes 0. At the same time when the torque of the reel motor 7 is set to 0, the brake solenoid control command g becomes HIGH level, the brake solenoid 14 is operated via the drive circuit 23, and the reel brake brake pad 13 causes the reel motor 7 to operate. Braking 7 Further, the pinch solenoid control command h also becomes LOW level at the same timing, and the pinch solenoid 28 is operated via the drive circuit 30 to remove the pinch roller 27 from the capstan motor 5. The control signal d of the reel motor 6 is also an analog signal proportional to the generated torque, and when the loosening mode is entered, the voltage gradually decreases and the torque also decreases. Along with this, the tape tension gradually decreases and the spring 16 connected to the movable post 15 gradually expands, whereby the take-up reel 3 rotates in the feeding direction by the amount that the tape is pulled. By gradually reducing the torque of the reel motor 6 in this way, tape slack due to excessive loosening is less likely to occur.

The FG signal c of the reel motor 6 at this time becomes a pulse train as shown in FIG. 2 and is applied to the losing control circuit 25. Further, the winding diameter information b of the take-up reel 3 is added to the loosening control circuit 25, and the FG signal c
The voltage of the control signal d continues to decrease until the value reaches a value preset according to the winding diameter information b, and when it reaches 0 V at time T, it becomes a negative voltage thereafter. Torque in the feeding direction is generated in the motor 6. When the value obtained by counting the pulses of the FG signal c reaches a preset value, the brake solenoid control command f becomes HIGH level, the brake solenoid 12 is operated via the drive circuit 29, and the brake pad of the reel brake is set. The reel motor 6 is braked by 11. At the same time, the control signal d is fixed at 0V. The torque in the feeding direction of the reel motor 6 is necessary because the tape and the head are still in contact with each other even when the tension becomes 0 g, which causes the head clogging. Until the tape and the head almost contact each other. Loosen the tape.

As described above, the routing control circuit 2
5 and the reel control circuit 24, the reading command signal a
This constitutes a control means for controlling the operation of the reel brake and the torque of the reel motor.

In the above embodiment, the supply reel is fixed and the magnetic tape is pulled out from the winding reel in the rudging mode. Fix and supply
Alternatively, the magnetic tape may be pulled out from the cable.

Further, according to the present invention, when the movable post 15 is provided as in the above-described embodiment, the magnetic tape withdrawal amount in the loosening mode increases, but the effect is particularly great.
It is also effective when the movable post 15 is not provided.

[0023]

As described above, according to the present invention, when the loosening command signal is input, the torque of the first reel motor is reduced after the second reel motor is braked, and the frequency signal generator operates. The output signal is counted, and when the count value reaches a value set by the winding diameter, the first reel motor is braked to perform the loosing, so that the loosing is performed even if the winding diameter of the magnetic tape is different. There is no variation in the amount of looseness of the magnetic tape at this time, and there is an effect that stable loosening can be performed.

Further, by gradually reducing the torque of the first reel motor, it is possible to prevent the magnetic tape from being loosened too much.

Further, when the torque becomes zero, the torque in the opposite direction is gradually increased and the magnetic tape is fed out, so that sufficient loosening can be performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a magnetic recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a timing chart showing the operation of the magnetic recording / reproducing apparatus according to the embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a conventional magnetic recording / reproducing apparatus.

FIG. 4 is a timing chart showing the operation of a conventional magnetic recording / reproducing apparatus.

[Explanation of symbols]

 1 magnetic tape 2 drum 3 take-up reel 4 supply reel 5 capstan motor 6, 7 reel motor 8, 9, 10 frequency signal generator 11 brake pad 12 brake solenoid 13 brake pad 14 brake solenoid 15 movable post 16 spring 17, 18 Post 19 Drive circuit 20, 21 Waveform shaping circuit 22, 23 Drive circuit 24 Reel control circuit 25 Loosening control circuit 26 Waveform shaping circuit 27 Pinch roller 28 Pinch solenoid 29, 30 Drive circuit

Claims (4)

[Claims] 1. A first reel motor and a second reel motor for applying a rotational force to a first reel and a second reel for winding or supplying a magnetic tape, respectively, and the first reel and the first reel motor. A drum around which the magnetic tape is wound between two reels, a first reel brake that brakes the first reel motor, and a second reel that brakes the second reel motor. A brake, a frequency signal generator for generating a signal having a frequency proportional to the rotation speed of the first reel motor, and a winding diameter detecting means for detecting a winding diameter of the magnetic tape wound on the first reel, The loosening command signal for loosening the magnetic tape wound on the drum, the output signal of the frequency signal generator, and the output signal of the winding diameter detecting means are input, and the torque of the first reel motor and the first reel motor are input. Re Control means for controlling the operation of the second reel brake, and the control means controls the operation of the second reel brake so as to brake the second reel motor when the losing command signal is input. Controlling the torque of the first reel motor and counting the output signal of the frequency signal generator, and the count value has reached a value set by the output signal of the winding diameter detecting means. At this time, the operation of the first reel brake is controlled so as to brake the first reel motor. 2. The magnetic recording / reproducing apparatus according to claim 1, further comprising a movable post that moves according to the tension of the magnetic tape. 3. The magnetic device according to claim 1, wherein the control means controls the torque of the first reel motor to gradually decrease when the losing command signal is input. Recording / playback device. 4. The control means controls to gradually decrease the torque of the first reel motor when a losing command signal is input, and gradually increase the torque in the reverse direction when the torque reaches zero. The magnetic recording / reproducing apparatus according to claim 1 or 2, which is characterized.