JPS6271047A - Capstan control system - Google Patents

Abstract

PURPOSE:To shorten a delay time when a capstan is turned reversely so as to prevent processing time from being increased, by extending the time of stopping/reversely actuating the capstan when the capstan is turned reversely by a half or more of the reel motor actuating time. CONSTITUTION:Only when a capstan is turned reversely, the time for stopping/ reversely actuating the capstan is extended by a half or more of the reel motor actuating time. When the capstan is controlled in such a way, more time is required for actuating/stopping the capstan, but the turnaround delay is made unnecessary, and the actuating/stopping time becomes shorter than the turnaround delay.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a magnetic tape device, and more particularly to a capstan control method suitable for shortening the delay time during capstan reversal.

[Background of the invention]

Conventional magnetic tape device IF equipped with a vacuum column
, for example, Hitachi's H-8487-Al2
O The area between the data blocks on the magnetic tape is not written as described in the operation manual (IBG).
), the capstan is started/stopped.

On the other hand, when controlling the tape reel that takes up and supplies the tape conveyed by the cabstan, the inertia of the reel including the tape to be controlled is much larger than the inertia of the capstan, so the capstan starts/stops. In some cases, a stone vacuum is used as a buffer to absorb errors in the tape feed rate and winding (or supply) caused by the reel's tape winding (or supply) not being able to sufficiently follow changes in the capstan's tape feed rate. The argument is that tape loose movement must be suppressed in the column.

The most severe capstan operation (large tape loop movement) for reel control that requires such conditions is turnaround, which involves reversing the tape without the tape feeding direction. However, since it is not possible to make the column long in small equipment, the capstan operation is limited by a certain stop time (turn/around delay) before the column is reversed. For this reason, the above-mentioned stop time becomes loss time, leading to an increase in processing time.

[Purpose of the invention]

The purpose of the present invention is to shorten the delay time when reversing the capstan without increasing the length of the vacuum column or increasing the torque of the motor, without affecting the size of the device. The purpose is to provide a capstan control method.

[Summary of the invention]

In a $K tape device, the information on the tape is read,
'When writing, the tape is run and started/stopped within the IBG in order to keep the speed of the tape passing through the head at a predetermined speed. vinegar.

In other words, it occurs while the IBG passes over the head.

A movement/stop is in progress. In normal processing when a read/write error does not occur, startup/stop within the IBG is necessary because the startup timing from the magnetic tape control device cannot be predicted, but when an error occurs, the next processing is Since it is determined that the block where the error occurred is to be read (or rewritten), the block where the error occurred is
Once the location is clear, start the capstan in the IBG/
There is no need to stop it. Now start the capstan/
If there is no need to stop IBG, ^, the start/stop acceleration can be reduced, and by bringing it closer to the reel control acceleration, the moving distance in the tape loose vacuum column can be reduced. . Using this type of capstan control takes time to start/stop, but no turnaround delay is required and the start/stop time is shorter than a turn/around delay, reducing loss time. I can do it.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In Fig. 1, the rotation speed of the gear stan motor (4) is determined by a counter (6) using pulses generated by an encoder (5) and a constant period pulse CL OK (8).
When starting is started, it is compared with a constant value n, and the error signal is the starting time of the capstan motor/ms. ) and drives the motor via a power amplifier (3). On the other hand, if the next operation is to try again in response to the occurrence of an error, the control signal RK T
5W (10) is switched by RY (7) and the error signal is a constant circuit [2] with a gain Ks of 1/30 of 1.
) is supplied to the power amplifier C3) Ic.

Therefore, the stop/start time increases by 30 times, as shown in Figure 2 (a).
The capstan stop/start characteristics are as follows.

The tape feed speed of the reel is 5 as shown in g2@(b), and the tape loop movement amount is It's small. In contrast,
As shown by the broken line in Figure 2, stop at 5 Urns and 110
ms, i.e. 70rns tar/
In the conventional method of adding around, Fig. 2(c) K
As shown by the broken line, the amount of tape loop movement increases and exceeds the amount of movement at startup, so repeating the same reversal increases the amount of tape loop movement and causes it to jump out of the vacuum column.

When performing capstan control according to the present invention, it is necessary to clearly indicate the data block position where an error has occurred. ),
Detecting data block position.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, the capstan reversal delay time for performing a retry operation when an error occurs can be shortened by about 30 -, so an increase in tape processing time can be suppressed. .

[Brief explanation of drawings]

Figure 1 is a block diagram showing one embodiment of the present invention - Figure 2 (
a) to (C) are characteristic diagrams for explaining the operation of the above embodiment. 1.2...Constant circuit, 3...Amplification circuit, 4...Capstan motor, 5...Encoder, 6...Pulse Φ counter, 9...Position counter.

Claims (1)

[Claims] In the capstan control of a magnetic tape device that has a vacuum column, the tape is fed by the capstan, and the start and stop of the capstan is started and stopped within the IBG. A capstan control method that lengthens the startup time by more than half.