JPH0258721A - Head positioning controller - Google Patents

Abstract

PURPOSE:To prevent deviation of the center of a read head from the center of a data rack by inputting a mean amplitude value signal and calculating the corrected moving distance of the read head from the value when a magnetic tape is run in the forwarding direction and that when the tape is run in the reversing direction by using a prescribed calculation formula, and then commanding a read head position moving circuit to make a correcting movement operation. CONSTITUTION:A read head correcting distance calculation circuit 11 which inputs a mean amplitude value signal, calculates the corrected moving distance of a read head 6 from the value when a magnetic head is run in the forwarding direction and that when the tape is run in the reversing direction by using a prescribed calculating formula, and outputs a correcting movement signal which commands a read head position moving circuit 12 to make a correcting movement operation is provided. Since the deviation between the center of the read head and that of a data track on the magnetic pate is corrected in such way, the error in the position of the read head against the position of the data track can be eliminated. Therefore, the center of the read head can be positioned easily to the center of the data track written with a write head.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a magnetic tape device that writes or reads data track by track on a magnetic tape having a plurality of tracks on one magnetic tape. The present invention relates to a head position control device for controlling the positioning of a read head during data reading in order to ensure compatibility between devices.

[Conventional technology]

For magnetic tapes with multiple data tracks,
A magnetic tape device that writes or reads data on one track at a time uses one write head or one read head to write or read data on each track. An action is being taken to move the read head.

When reading data, the read head is positioned at the same position as the data track written on the magnetic tape, but conventional head positioning control devices for this purpose position the read head by moving it in the tape width direction. ,
Positioning control is performed by controlling the number of feed steps of the stepping motor.

[Problem to be solved by the invention]

The head positioning control device of the conventional magnetic tape device described above suffers from variations in mechanical accuracy of the base plate and guides used to hold the magnetic tape, and the position of the read head and write head within the stepping motor and head housing. Due to the fluctuation, the relative positional relationship between the rack where data is written to data 1 and the read head that reads it shifts, and the center of the read head shifts from the center of the data track. If there is dropout such as dust or peeling of the magnetic surface, there is a disadvantage that a part that is normally processed during writing cannot be read correctly during reading, resulting in a read error.

[Means to solve the problem]

The head positioning control device of the present invention adjusts the width of the read head (, ffR> half (ρR/2)
The average value VP of the magnitude of the read signal read from the read head when the read head is moved upward by the width of the read head when the read head is moved upward by The average value (■) of the magnitude of the read signal read from the read head after moving downward by half (ρR/2) of (ρn). By this, the difference between the center of the read head and the center of the data track written on the tape is corrected, and the error in the position of the read head with respect to the position of the data track is eliminated.

That is, the head positioning control device of the present invention includes a tape running control circuit that inputs a retention signal and sends out a forward signal or a reverse signal that causes the magnetic tape to run in the forward or reverse direction, and a tape running control circuit that sends out a forward signal or a reverse signal that causes the magnetic tape to run in the forward or reverse direction; a tape drive servo circuit that inputs and sends out a tape drive signal; a capstan motor power amplifier that inputs the tape drive signal and sends out an amplified capstan motor drive signal; a capstan motor that causes the magnetic tape to run in the forward direction or the reverse direction; a read head position movement circuit that sends out a read head movement signal to move the read head by half of the read head movement signal; a stepping motor power amplifier that sends out a stepping motor drive signal that is amplified by inputting the read head movement signal; and a stepping motor power amplifier that sends out a stepping motor drive signal that is amplified by inputting the read head movement signal a stepping motor that moves the read head by inputting it; a read amplifier that inputs and amplifies the read signal of the read head; and an amplitude average that inputs the output signal of the read amplifier and calculates the average value of the amplitude. A read signal amplitude averaging circuit outputs a value signal, and a read signal amplitude averaging circuit inputs the amplitude average value signal to calculate the value of the read head according to a predetermined calculation formula from the value when the magnetic tape is running in the forward direction and the value when the magnetic tape is running in the reverse direction. The read head correction distance calculation circuit calculates a correction movement distance and outputs a correction movement signal for instructing the read head position movement circuit to perform a correction movement operation.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention.

In FIG. 1, when a tape running control circuit 2 receives a retention signal 1, it sends out a forward signal 9 to operate a capstan motor 5 via a tape running servo circuit 3 and a capstan motor power amplifier 4, thereby controlling the magnetic tape. (run in the forward direction from the BOT mark to the EOT mark). The head position moving circuit 12 operates the stepping motor 14 for rad operation via the stepping motor power amplifier 13 to change the position of the read head 6 in the width direction of the tape - half the width (ρR) of the F head 6 ( ρR/2). The read signal amplitude averaging circuit 8 outputs a signal that averages the magnitude of the read signal read by the read head 6, and the read head correction distance calculation circuit (calculation circuit) 11 outputs a signal that averages the magnitude of the read signal read by the read head 6. At the point in time, the output signal (size Vp) of the read signal amplitude averaging circuit 8 is taken in and stored.

When the EOT mark is detected, the tape running control circuit 2 sends out a reverse signal 10 to run the magnetic tape in the opposite direction from the EOT mark to the BOT mark (reverse direction running). At this time, the head position moving circuit 12 moves the position of the read head 6 in the width direction of the tape by the width of the read head 6 ((R
) is moved down by half (ρR/2). The read signal amplitude averaging circuit 8 averages the magnitude of the read signal read by the read head 6 at this time and sends out a signal, and the arithmetic circuit 11 averages the magnitude of the read signal read at this time by the read head 6, and the arithmetic circuit 11 averages the magnitude of the read signal amplitude read at this time by the read head 6. The output signal (size VR) is captured and stored. After this, the arithmetic circuit 1] uses the following arithmetic expression <
1> Calculate the correction distance ρ' of the lift head 6,
By moving the read head 6 through the head position moving circuit 12 in the direction where the successive output signal is smaller, the center of the read head is made to coincide with the center of data 1 to rack written by the write head.

〔Effect of the invention〕

As explained above, the head positioning control device of the present invention has the advantage that the center of the read head can be easily aligned with the center of the data track written by the write head, and therefore the same magnetic tape can be The advantage is that compatibility can be maintained with a plurality of magnetic tape devices, and data can be read with high reliability.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention. ■... Retention signal, 2... Tape running control circuit 3,... Tape running servo circuit, 4... Capstan motor power amplifier, 5... Capstan motor, 6... Read head, 7...Low 1-amp, 8
... Read signal amplitude averaging circuit, 9... Forward signal, 10... Reverse signal, 11... Read head correction distance calculation circuit, 12... Read head position movement circuit, 13... Stepping motor power amplifier, 14
...Stepping motor.

Claims (1)

[Claims] A tape running control circuit that inputs a retention signal and sends out a forward signal or a reverse signal that causes the magnetic tape to run in the forward or reverse direction; and a tape running control circuit that sends out a tape drive signal by inputting the forward signal or the reverse signal. a servo circuit, a capstan motor power amplifier that inputs the tape drive signal and sends out an amplified capstan motor drive signal, and a capstan that runs the magnetic tape in a forward or reverse direction based on the capstan motor drive signal. a motor; and a read head movement signal for moving the read head upward or downward in the width direction of the magnetic tape by half the width of the read head when the magnetic tape runs in the forward direction or the reverse direction. a stepper motor power amplifier that inputs the read head movement signal and outputs an amplified stepping motor drive signal; and a stepping motor that inputs the stepping motor drive signal and moves the read head. a motor, a read amplifier that inputs and amplifies the read signal of the read head, and a read signal amplitude averaging circuit that inputs the output signal of the read amplifier and outputs an amplitude average value signal obtained by taking the average value of the amplitude. , the read head position is determined by inputting the amplitude average value signal and calculating the corrected movement distance of the read head using a predetermined calculation formula from the value when the magnetic tape is running in the forward direction and the value when the magnetic tape is running in the reverse direction. A head positioning control device comprising: a read head correction distance calculation circuit that outputs a correction movement signal that instructs a movement circuit to perform a correction movement operation.