JPH0550063B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for transferring a flexible medium such as a tape or a wave from reel to reel,
In particular, the present invention relates to a tape transport device suitable for transporting tape or waves with high precision.

[Conventional technology]

Conventional devices, for example, as described in Japanese Patent Application Laid-Open No. 59-116951, are provided with an actuator buffer for adjusting the tape length between reels, and the actuator buffer is set to a predetermined tape tension. Adjusting the tape length between the reels and adjusting the tape tension between the reels by generating a balanced and uniform force and following the movable part of the actuator buffer according to the tape tension between the reels. A tape buffer mechanism is disclosed.

[Problem to be solved by the invention]

In the conventional tape buffer mechanism, the movable part of the actuator buffer moves voluntarily according to the tape tension due to the force balance between the tape tension between the reels and the force generated by the actuator buffer. It was hot. As a result, in conventional devices, there is a delay in operation due to the mass of the actuator buffer movable part, etc., and minute tape speed fluctuations and tension fluctuations, which are obstacles when reading and writing information on the tape at the read/write head, such as However, the frequency range in which relatively high-speed changes in tape tension such as tape vibration can be reduced was limited to low frequencies.

An object of the present invention is to reduce tape vibrations that cause tape speed fluctuations and tension fluctuations in a relatively high frequency range near the magnetic head, in order to accurately read and write information on the tape in the magnetic head. An object of the present invention is to provide a tape tension adjustment device that enables highly accurate tape transfer.

[Means to solve the problem]

In the present invention, two reels wound with magnetic tape are driven by separate motors, and the magnetic tape is transferred from one reel to the other through a magnetic head section provided between the reels. A tape tension adjustment device for adjusting the tape tension of a magnetic tape device that reads and writes information on a magnetic tape by transporting the tape, comprising means arranged between the reels for adjusting the tape tension between the reels, and means for detecting the tape tension. and means for controlling the tape tension adjustment means, the control means controlling the tape tension adjustment means using a signal from the tape tension detection means so that the tape tension becomes a predetermined value. and a means for detecting the position of the movable part of the tape tension adjusting means, and using a signal from the position detecting means, the movable part of the tape tension adjusting means returns to a predetermined position. In order to adjust the tape tension, the apparatus is characterized in that it includes a second tape tension adjustment means that controls the rotation of at least one of the motors that drive the reels.

[Effect]

First, current is supplied from the reel control means to the two motors via the reel drive means so as to apply a predetermined tension to the tape stretched between the two reels. As a result, a predetermined tension is applied to the tape.

On the other hand, a tension buffer is installed near the magnetic head and adjusts the tape tension by adjusting the tape length. Supplied from means. Further, the movable part of the tension buffer is held at a predetermined position by the reel control means via the reel drive means in response to a signal from the displacement detection means of the tension buffer.

In this state, an accelerating current is applied in response to a signal from the reel control means to drive the motor, and tape transfer between the reels is started.

When an error occurs in the tape tension near the magnetic head section from a predetermined value as the tape is transported, a signal from a tension detection means provided near the magnetic head section causes the tension buffer control means to detect this error. A correction current to eliminate the error is calculated and applied to the actuator of the tension buffer. Thereby, the tension error generated in the tape near the magnetic head section can be controlled to be instantly eliminated by actively moving the tension buffer provided near the magnetic head section.

〔Example〕

FIG. 1 shows an embodiment of the tape transport device of the present invention. In this figure, a tape transport device runs a magnetic tape at a predetermined speed, and uses a magnetic head to record information on the tape and reproduce information from the tape. 5 is a magnetic tape; 3 and 4 are reels on which the magnetic tape 5 is wound; these reels 3 and 4 are driven by motors 1 and 2, respectively. By driving the motors 1 and 2, the magnetic tape 5 is transferred from one reel 4 to the other reel 3 via a tension buffer 9, a magnetic head 6, and a speed tachometer roller 8.

In this tape transfer device, tachometers 11 and 12 have a control algorithm that detects the radius of the reels 3 and 4 in advance and determines the operating current of the motors 1 and 2 before running the tape; Detect the rotation amount of 4. On the other hand, 1
0 is a minute tachometer, which detects minute rotations of the speed tachometer roller 8. Here, reel 3
However, the length of the tape to be wound is equal to the length of the tape passed through the speed tachometer roller 8. Therefore,
The radius of the reel 3 can be determined by comparing the rotation amounts of both. The same applies to reel 4. A controller 16 receives signals from each tachometer 10, 11 and 12 and calculates the radius of the reels 3 and 4. In the control algorithm within the controller 16, once the reel radius, which is a variable, is determined, the operating currents of the motors 1 and 2 can be calculated. Controller 16 drives motors 1 and 2 via power amplifiers 14 and 15. Further, the reel radius can be detected every time a signal is generated by the tachometers 11 and 12, and each radius value is updated in the controller 16.

The tension buffer 9 adjusts the tape tension necessary for recording or reproducing information on the tape, and an example of its configuration is shown in FIG. In this figure, parts with the same reference numerals as those in FIG. 1 are the same.
The magnetic tape 5 is hung on the roller 7 as shown in the figure.
The tape length can be adjusted by moving the roller 7. The rollers 7 are rotatably mounted on a roller support (not shown), which is fixed to a carriage 19. This carriage 19 is supported by a fixed block 21 so that its position can be adjusted, and is fixed to a coil 22 of a linear motor. A sensor 18 is arranged on the carriage 19 to detect the displacement of the roller 7 from the fixed block 21. The signal of the position sensor 18 is sent to the sensor circuit 1
3, the signal is returned as a position signal and sent to the controller 16.
Further, a stress sensor 20 for detecting the force that the roller 7 receives from the tape 5 is arranged on the roller support body. Similar to the position sensor 18, the signal from the stress sensor 20 is converted by the sensor circuit 13 into a signal representing tape tension and sent to the controller 16. Further, the current of the coil 22 of the linear motor is controlled by the controller 16 via the power amplifier 17.

Next, the tape tension adjustment operation will be explained.

In FIG. 1, a constant tape tension is applied to the tape 5. At this time, a bias current sufficient to balance the tape tension is flowing through the coil 22 of the linear motor of the tension buffer 9, and in a steady state, the roller 7 is set at a reference position half of its movable range from the fixed block 21. Adjustment of this reference position takes place within the controller 16. That is, a positional error of the roller 7 is detected based on a signal from the position sensor 18, and a current is applied to the motor 2 to correct this error. Along with this, the tape length between the reels 3 and 4 is adjusted by minute rotation of the reel 4, and the reference position of the roller 7 is adjusted. This is tension adjustment by the reel and motor.

On the other hand, the stress sensor 20 within the roller 7 detects the tape tension acting on the roller 7, and is adjusted within the controller 16 so that the tension is always constant. When a tension error is detected within the controller 16, a correction current is generated in the linear motor coil 22 via the power amplifier 17. The coil 22 receives thrust from the linear motor and moves the roller 7. As the roller 7 moves, the length of the tape in the tape tension buffer 9 changes and the tape tension is adjusted. For example, if the tension error is positive, the roller 7 moves in the direction of loosening the tape.
moves. This is lightweight linear motor coil 2
This is the tension adjustment according to No. 2.

As explained above, the tension buffer 9 performs two-stage tape tension adjustment. That is, high-frequency tension fluctuations are adjusted by an actuator consisting of a lightweight linear motor coil 22, and low-frequency tension fluctuations are adjusted by a reel and a motor. At this time, the controller 16
In this case, the control algorithm is configured so that both actuators do not interfere with each other.

FIG. 3 shows another configuration of the tension buffer 9 in FIG. 1, and in this figure, parts with the same symbols as those in FIGS. 1 and 2 are the same. Third
This figure differs from FIG. 2 in the tape loading method and the actuator shape. However, since the functions and operations are the same as those in FIG. 2, their explanation will be omitted.

〔Effect of the invention〕

According to the present invention, it is possible to reduce tension fluctuations with a high vibration frequency, and it is possible to cover a wide range from low to high frequencies, which was not possible in the past. Furthermore, power consumption can be reduced by using different actuators depending on the vibration frequency.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration diagram of an embodiment of the present invention, Fig. 2
3 and 3 are diagrams showing the structure of a specific example of the tension buffer shown in FIG. 1. 1, 2...Motor, 3, 4...Reel, 5...
Tape, 7...Roller, 9...Tension buffer, 1
3... Sensor circuit, 16... Controller, 18... Position sensor, 19... Carriage, 20... Stress sensor, 21... Fixed block, 22... Linear motor coil.

Claims (1)

[Claims] 1. Two reels wound with magnetic tape are driven by separate motors, and the magnetic tape is transferred from one reel to the other through a magnetic head section provided between the reels. A tape tension adjustment device that adjusts the tape tension of a magnetic tape device that reads and writes information on the magnetic tape through this transfer includes a means for adjusting the tape tension between the reels and a means for detecting the tape tension. and a means for controlling the tape tension adjustment means, the control means controlling the tape tension adjustment means using the signal from the tape tension detection means so that the tape tension becomes a predetermined value. The tape tension adjusting means includes tape tension adjusting means and means for detecting the position of the movable part of the tape tension adjusting means, and uses a signal from the position detecting means to adjust the tape between the reels so that the movable part of the tape tension adjusting means returns to a predetermined position. To adjust the tension,
A tape tension adjustment device comprising a second tape tension adjustment means for controlling rotation of at least one of the motors that drive the reel.