JPS593732A - Step control system - Google Patents

Abstract

PURPOSE:To prevent deterioration in efficiency by detecting a servo signal when a step advance is made under the command of a high priority device and finding the movement extent of a capstance motor, and calculating the displacement of a head from a stripe to which the step advance is made and making corrections. CONSTITUTION:A timing generating circuit 30 generates timing pulses for fetching the movement extent of the capstan motor 31 up to when a trailing servomechanism is read from a start pulse arriving at a terminal B and sends them to a counter 21. The counter 21 counts the rotation extent of the capsten motor 31 and sends the counted value to a control part 20. The control part 20 calculates the rotation extent of the capstan motor 31 by using tachometer pulses from a capstan tachometer detecting circuit 24 in combination to correct a reference value, and sends the corrected value to a write inhibition command generating circuit 28. Thus, the reference value is corrected on the basis of the actual movement extent of a tape to evade an excessive write inhibiting command, preventing deterioration in efficiency.

Description

[Detailed Description of the Invention] tal Technical Field of the Invention Is the present invention a cylindrical magnetic tape? Relating to a magnetic recording and reproducing device that records or reproduces data on stripes formed perpendicularly or diagonally to the longitudinal direction of the magnetic tape used,
Especially data on magnetic tape? The present invention relates to a step control method for controlling the entire step operation of a magnetic tape, which enables all write operations to be performed accurately and at high speed.

(bJ Prior art and problems cylindrical magnetic tape? An example of a magnetic tape formatting system that uses a cylindrical magnetic tape and records or reproduces data entirely in stripes formed at right angles or diagonals to the longitudinal direction of the magnetic tape. "FI1" is shown in the figure. 1 is a magnetic tape, 2 is an ID) rack in which the unique number of the stripe is recorded fk3,
3 is a reading servo, 4 is a data stripe for recording data, and 5 is a stripe ringing servo used for step control of the magnetic tape I and for creating a write inhibit command according to the present invention.

FIG. 2 (When a move or read/write command is received from the host device, the capstan motor of the magnetic storage/reproducing device winds up the magnetic tape shown in FIG. 1 above and moves to the next stripe.
FIG. 4 is a diagram illustrating the operation 4. 4', 5
', 2, 3, 4, and 5 are all output waveforms of the bonding head? These are the read waveforms of the ID track 2, leading servo 3, f-ta stripe 4, and tray link servo 5 shown in FIG. The servo? Show each.

Figure 3 is a block diagram of the circuits that constitute the entire step control system of the prior art. Figures 2 and 3? I will explain using Reference numeral 6 indicates a timing waveform indicating the entire write data area, which is also a timing pulse for the control section 20 to issue a full operation command to the capstan motor 30. Reference numeral 7 indicates a start pulse for taking in the trailing servo 5' and 5 gold. A move or read/write command from a higher-level device is input to the terminal A, and a start pulse 7 for capturing trailing servo is input to the terminal B.

The amount of movement to the next stripe (abbreviated as MDG) is set in the control section 20 at the falling edge of the timing pulse 6 in FIG. When the MDG is set, counter 2
1 to the digital/analog conversion circuit 22, and the cabstan motor drive circuit 23 drives the capstan motor 30 to rotate by the standard leg movement amount. The amount of rotation of the cannon motor 30 is determined by the capstan tachometer detection circuit 24 and sent to the control unit 2 as a tacho pulse.
Reported to 0. At this time, the magnetic tape 1 is wound onto the spool driven by the drive circuit 27 and taken up by the capstan motor 30, and the write head 26 generates the waveforms shown in FIGS. the amplifier 25
The signal is sent to the servo detection circuit 29 via the servo detection circuit 29. Servo detection circuit 29
is the servo bit total control section 20 and the write inhibit command generation circuit 2
Send to 8. 8 is an example of the output waveform of the digital/analog conversion circuit 22 for driving the capstan motor.
The voltage drops instantaneously at the falling edge of the timing pulse 6, and the output of the digital I of the counter 21 causes the voltage to drop instantly.
The output of the digital/analog conversion circuit 22 rises sequentially as shown in the figure, and becomes stable when it reaches the voltage level. As described above, the output voltage of the capstan motor 3 (1: digital However, as mentioned above, the trailing servo 5 in FIG. has already started to make a rotating sound, and depending on the writing timing from the counter 20, the count value from the counter 21, and the output from the servo detection circuit 29 as shown in FIG. If there is a large deviation, use the write-protection finger 4 yen at the timing shown in Figure 2 10.
This prevents data from being recorded at a position deviated from the data stratum 4 shown in FIG. The reference value for the slippage of 1lll amount is the tray link servo 5'? The total amount of movement of the capstan motor 30 until reading was calculated statistically and determined to be approximately 1.5 QTP, which is used as the reference value.

FIG. 4 is a diagram illustrating variations in the step response when stepping the magnetic tape l, depending on the characteristics of the power booster of the analog circuit of the digital/analog conversion circuit 22 of FIG. 3. 8 due to the characteristics of the power amplifier of the analog circuit.
The characteristics shown by are changed, and the output waveform of the digital/analog converter 22 varies at startup as shown by 15°16.17.

Therefore, is the output with such a large difference in fluctuation? Since the amount of rotation (QTP) of the capstan motor 30 that is received naturally fluctuates, the reference value is 1.5 QTP, but within the range shown by 12, if it is 15, it will be several QTP in the positive direction, and if it is 17, it will be in the negative direction. is shifted by several QTP. Therefore, the write inhibit command occurs at a value exceeding α above the standard value, but is it the standard value? Is it inappropriate to set 1.5QTP, and a step operation that is not originally an error is determined to be an error and a write prohibition command is issued? This has the drawback of reducing the efficiency of the fragrance operation.

tel Purpose of the Invention Is the purpose of the present invention to solve the above drawbacks? How much did the capstan motor actually move before reading the trailing servo sound? Accurately recognize, read the true QTPp, correct the reference value, and check the reference value? An object of the present invention is to provide a step control system that improves the efficiency of writing operations by making it variable according to the amount of rotation of a capstan motor.

ldl Structure of the Invention The structure of the present invention is to record or reproduce 7 lines using head sound on stripes formed perpendicularly or diagonally to the longitudinal direction of the recording medium, and to receive movement commands or read/write from a host device. In a magnetic recording/reproducing device that steps to the next stripe in response to a write command, from when a step command is issued to the servo signal detection means and the capstan motor until the servo signal detection means detects all the corresponding servo signals. How much did it move? A detecting means is provided to calculate the amount of movement of the capstan motor and the deviation between the head and the stripe to be stepped.

te+ Embodiment of the Invention FIG. 5 is a block diagram of a circuit according to an embodiment of the invention. A timing generation circuit 30i is added to the circuit shown in Fig. 3,
The timing generating circuit 30 generates a timing pulse 13 that captures the amount of movement of the capstan motor 30 until reading the trailing servo 51 + shown in FIG. 4 from the start pulse 7 (FIGS. 2 and 4) input from terminal B. , is sent to the counter 21. The counter 21 counts the amount of rotation t of the capstan motor 30 for the time shown in FIG. The control unit 20 sends the signal to the capstan tachometer detection circuit 24 and to the circuit 28 . That is, the range shown in FIG. 4 12? Please fix it.
From the read servo pit value, capstan motor 30
The amount of rotation (QTP) is subtracted by 4.

Is Figure 6 another example? FIG. 2 is a block diagram of the circuit shown in FIG. Is there a timing generation circuit 30 and a capstan motor rotation amount detection circuit 31 in the circuit shown in FIG. It was added. The capstan motor rotation amount detection circuit 31 uses the output tacho pulse of the capstankometer detection circuit 24 and the servo detection circuit 2.
9 and the output of the timing generation circuit 30, the fourth
14 (capstan motor movement amount = x
QTP), detects the true amount of deviation of the magnetic tape, calculates it, and sends it to the control section 20. Is the control unit 20 the reference value? It is corrected and sent to the write inhibit command generation circuit 28.

(fl) As described in detail, the present invention is based on the characteristics of the capstan/amplifier that fully drives the capstan/motor so that the amount of rotation of the conventional capstan motor, that is, the amount of movement of the magnetic tape, is determined by the characteristics of the capstan/amplifier that fully drives the motor. Items whose movement amount fluctuates
Since the line movement 41 is set as a constant value as the criterion value for sending the write prohibition command, efficiency decreases due to the write prohibition command being issued even though the positions of the RAD and the magnetic tape stripe are originally aligned. ? This can be prevented by changing the reference value kOJ depending on the actual amount of movement of the magnetic tape, and this has a great effect.

[Brief explanation of drawings]

Figure 1 shows an example of the magnetic tape format in Figure 87, and Figure 2 shows the previous step of the capstan motor? Control timing and characteristic diagram of the analog circuit. Figure 3 is a block diagram of the circuits that make up the conventional step control method. Figure 4 is a diagram explaining the characteristics of the analog circuit for driving the capstan motor and variations in step operation. 5 is a block diagram of a circuit showing one embodiment of the present invention, and FIG. 6 is a block diagram of a circuit showing another embodiment. 1 is a magnetic tape, 2 is an ID track, 3 is a leading servo, 4 is a data stripe, 5 is a trailing servo, 20 is a control section, 21 is a counter, 22 is a digital/analog conversion circuit, 23 is a capstan drive circuit, 2
4 is a capstan tachometer detection circuit (QTP generation circuit), 25 is an amplifier, 26 is a write head, 27 is a spool I drive circuit, 28 is a write inhibit command generation circuit, 29 is a servo detection circuit, 30 is a timing generation circuit , 31 is a capstan motor rotation amount detection circuit.

Claims (1)

[Claims] A magnetic recording medium that uses a head to record or reproduce all the stripes formed perpendicularly or diagonally to the longitudinal direction of the recording medium, and then steps to the next stripe in response to a movement command or read/write command from a host device. In the recording and reproducing device, there is a +J''-bore number detection means and a means for detecting the gk that is worked from the time when the capstan motor step command is issued until the servo signal detection means detects the corresponding servo signal. In general, the step control system is characterized by the friction between the moving hair of the capstan motor and the stripe that should be used for the step.