JPS61104356A - Tape transporting device - Google Patents

Abstract

PURPOSE:To reduce the variance of the access time and to make the high-speed access possible by detecting the time, when the tape speed reaches a prescribed value, to lead out an acceleration error and performing correction in accordance with this acceleration error signal. CONSTITUTION:Reels 2 and 3 around which a magnetic tape 1 is wound are driven by motors 4 and 5, and the tape 1 is transported from the reel 3 to the reel 2 through a tension sensor 6, a magnetic head 7, and a speed tachometer 8. A control circuit 9 generates signals S1 and S2 driving motors 4 and 5. An operating circuit 9a of the circuit 9 generates a maximum acceleration signal S3 and correcting signals S4 and S5, and a switching circuit 9d selects the signal S3 when the tape speed is lower than a target speed, and the circuit 9d selects a speed error signal between the tape speed and the target speed after the tape speed reaches a switching speed. A time counter 9g detects the switching time by the output of a speed detector 9b, and a correcting circuit 9i receives an acceleration signal corresponding to the switching time to store the signal which corrects the acceleration error. The stored value in the circuit 9i is added to signals S3 and S4.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a tape transfer device for transferring tape from reel to reel.

[Background of the invention]

2. Description of the Related Art Conventionally, as a component of an a-air storage device, a supply reel and a take-up reel are each driven by separate motors, and the magnetic tape wound on these reels is transferred to a head section. An example of this device is JP-A-52-
It is described in Japanese Patent No. 62004.

A reel-to-reel type tape transport device in this type of magnetic storage device is equipped with means for calculating and deriving the reel inertial load in order to control the movement of the tape. However, no consideration was given to correction of tape acceleration caused by errors in deriving the reel inertial load or constant errors in device components.

For this reason, in the tape transport device, when the tape is started at high acceleration to a predetermined speed, the time to reach the predetermined speed, in other words, the access time varies. moreover,
This acceleration error may induce vibrations in the mechanism.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a tape transfer device that can reduce fluctuations in access time and can perform high-speed access without inducing vibrations in the mechanism.

[Summary of the invention]

The present invention provides a reel-to-reel type tape transfer device.
Most of the mechanical vibration that occurs when the tape is started at high speed occurs in the leap that accelerates the tape at the maximum acceleration current, and focusing on the fact that it depends on the acceleration time, The apparatus is provided with means for correcting tape acceleration errors so as to eliminate fluctuations.

[Embodiments of the invention]

The present invention will be described in detail below with reference to FIGS. 1 to 5. FIG. 1 is a block diagram showing an embodiment of a tape transport device according to the present invention, in which 1 is a magnetic tape, and 2 and 3 are reels on which the magnetic tape 1 is wound.

These reels 2 and 3 are turned 1 tin by motors 4 and 5, respectively. Driven by the motors 4 and 5, the magnetic tape 1 is moved from one reel 8 to a tension sensor 6°, a magnetic head 7,
and is transferred to the other reel 2 via a speed tachometer 8.

Here, although the magnetic tape 1 is an elastic body with low rigidity made of polyester film or the like, the reel 23. Speed tachometer8. Several vibration modes are generated due to the moment of inertia of the tension sensor 6 and the springiness of the tape 1. These vibrations occur during the period when the tape 1 is being accelerated at maximum acceleration. The control circuit 9 provides control input signals 81 . to the motors 4 , 5 to control the movement of the tape l. S2, and the power amplifier 10.11 receives these signals S1°S2.
is converted into electric power to drive motors 4 and 5. Tension circuit 12
receives the signal from the tension sensor 6 and generates a tension vibration correction signal.

FIG. 2 is a block diagram showing details of the control circuit 9 described above. In FIG. 2, the arithmetic circuit 9a is a circuit (
(not shown) generates a maximum acceleration signal S3 and a first correction signal S4 for the reel load. Generate S5.

The speed detector 9b is a circuit that detects the pulse width of the speed tachometer signal S6 by counting the number of clocks from the reference clock generator 9c. The switching circuit 9d is
While the tape speed is smaller than the target speed, the maximum acceleration signal S3 is selected, and after reaching the switching speed, the speed error signal with respect to the target speed is selected. The signal of the switching circuit 9d is sent to the multiplier 9
e, 9f, the first correction signal S4. It is corrected in S5 and output to the power amplifier 10.11.

Here, the process of accelerating the tape 1 will be explained with reference to FIG. In FIG. 3, since a constant acceleration is generated until the switching speed v0 is reached, the tape speed increases linearly. Switching speed V. When the speed exceeds v0, the mode is switched to speed control mode, so that the speed approaches the target speed v0. If there is an acceleration error, the time it takes to reach the switching speed v6, the switching time 1c, changes. Furthermore, as a result, the access time required to reach the target speed also varies. If b is the speed curve when the acceleration is normal, the speed curve ma shows the case where the acceleration deviates in the positive direction, and the speed curve C shows the case where the acceleration deviates in the negative direction. Thus, acceleration errors can be detected by measuring the switching time.
- In FIG. 2, the one hour counter 9g detects the switching time by receiving the clock signal from the reference clock generator 9G and the speed signal from the speed detector 9b. Conversion table 9h
outputs the acceleration corresponding to the detected switching time. The relationship between switching time and acceleration is as shown in FIG. The correction circuit 91 receives the detected acceleration signal, calculates and stores a second correction value for eliminating the acceleration error. The output of the correction circuit 91 is added to the first correction signals S4 and S5 in an adder 9jt9 to correct the control inputs to the motors 4 and 5. here.

In the correction circuit 91, since the second correction value is stored,
Each time the tape acceleration operation is repeated, the acceleration error is eliminated. As a result, fluctuations in switching time are also eliminated.

In addition, as a result of analysis, the inventor of the present application has concluded that a servo technology that enables high-speed access without inducing vibrations in the mechanism in a servo device containing an elastic body.For example, the fall time of an input signal If is set to be an integral multiple of the period of the mechanism vibration, the tape vibration generated at the rising edge of the input signal will have a phase opposite to the tape vibration generated at the falling edge, and will be canceled out.

By applying the present invention, fluctuations in switching time can be eliminated and tape vibration can be stably reduced.

FIG. 5 is a configuration diagram showing another embodiment of the device of the present invention.
It is. In this example, the speed tachometer 8 is configured to measure the outermost peripheral speed of the reel 2.

With this configuration, speed tachometer 8 and tape 1
Tape vibrations caused by this are eliminated. Furthermore, the present invention shows that the configuration position of the speed tachometer 6 is not limited to the example shown in FIG.

〔Effect of the invention〕

As described above, according to the present invention, in a tape moving device, tape acceleration can be corrected, and fluctuations in access time can be reduced.

This has the effect of reducing tape vibration caused by tape acceleration errors. Furthermore, since fluctuations in the maximum acceleration time can be reduced, tape vibrations can be stably reduced.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing one embodiment of the device of the present invention, and FIG.
FIG. 2 is a block diagram showing details of a control circuit shown in the figure. 3 and 4 are diagrams for explaining the operation of the apparatus of the present invention, and FIG. 5 is a diagram showing another embodiment of the apparatus of the present invention. 1... Magnetic tape, 2, 3... Lee, Le, 4.5.
...Motor, 6...Tension sensor, 8...Speed tachometer, 9...Control circuit, 9a...Arithmetic circuit, 9b...
...Speed detector. 9c...Reference clock generator, 9d...Switching circuit. 9e, 9f... Multiplier, 9g... Time counter, 9
h... Conversion table, 91... Correction circuit, 9j, 9
k...$1 drawing 3 giant deaf 4 drawings

Claims (1)

[Claims] A tape transport device comprising a reel driving means for transporting the tape from one reel to the other reel, a means for detecting the time until the tape speed reaches a predetermined speed, and a means for detecting the time taken for the tape speed to reach a predetermined speed; It consists of means for deriving an acceleration error, and means for creating a correction signal for correcting the acceleration error using a signal from the deriving means, sending it to the reel driving means and storing it, and calculating the tape acceleration according to the correction signal. A tape transport device configured to perform correction.