JP2591856B2 - Floppy disk device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a floppy disk drive for exchanging a recording medium with another device for recording and reproducing information.

[Conventional technology]

In a floppy disk drive, the position of the magnetic head is slightly deviated from one device to another. Therefore, when a recording medium written by another device is loaded and read, the position of the read magnetic head is recorded. A so-called off-track occurs which deviates from the position of the recording track of the medium.

[Problems to be solved by the invention]

The conventional floppy disk device does not take any special measures against the above-mentioned inter-device off-track, and therefore, when information is read out by exchanging the recording medium with another device, time is lost due to off-track. There is a drawback that the margin is reduced and the ID section is erased due to side erase.

[Means for solving the problem]

In the floppy disk device of the present invention, when recording and reproducing information by exchanging a recording medium with another device, the magnetic head is automatically moved to correct off-track.

That is, the floppy disk drive of the present invention has two read / write gaps provided by dividing one head core into two and a winding wound around each of them.
Magnetic heads, two envelope detectors respectively connected to the two magnetic heads, a first monostable multivibrator for inputting a step pulse signal output from a host device, and A second monostable multivibrator for inputting an output signal of one monostable multivibrator, and inputting an output signal of the second monostable multivibrator and an output signal of each of the two envelope detectors. Sample and hold circuits, a stepper control circuit that inputs the step pulse signal and the direction signal output from the host device and outputs an excitation pattern of a stepper motor, an output signal of the stepper control circuit, and the two Input the output signal of the sample and hold circuit and compare the voltages of the output signals of the two sample and hold circuits. An error signal generation circuit that outputs two control signals, two FETs that input each of the two control signals to change the output current, and input each of the output currents of the two FETs Two H's that change the output current
A bridge circuit.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a correlation diagram showing a relationship between a track outputted from a stepper control circuit and an excitation pattern in the embodiment of FIG. 1, and FIG. 1 is a characteristic diagram showing the relationship between the off-track amount of the error signal generating circuit and the gate voltage of the FET in the embodiment of FIG. 1. FIG. 4 is a diagram showing the positional relationship between the magnetic head and the track of the recording medium in the embodiment of FIG. FIG. 5 is a plan view, and FIG. 5 is a waveform diagram showing the waveform of each signal in the embodiment of FIG.

The embodiment shown in FIG. 1 is composed of two read / write heads (magnetic heads) 9 and 10 having two read / write gaps provided by dividing one head core into two and windings wound around each of them. , Two envelope detectors 2 connected to each of the two magnetic heads 9 and 10,
A first monostable multivibrator 3 for inputting a step pulse signal 21 output from the host device, a second monostable multivibrator 4 for inputting an output signal 22 of the first monostable multivibrator 3, , Two sample-and-hold circuits 2 receiving the output signal 23 of the monostable multivibrator 4 and the output signals 33 and 34 of the two envelope detectors 1, respectively, and the step pulse signal 21 and the A stepper control circuit 6 for inputting a direction signal 24 and outputting an excitation pattern of a stepper motor; An error signal generating circuit 5 which compares the voltages of the output signals and outputs two control signals 35 and 36;
And two H-bridge circuits 7 for inputting the output currents of the two FETs and controlling the current balance by inputting the output currents of the two FETs, respectively. 8 is provided.

When the magnetic heads 9 and 10 are first moved to the designated track of the recording medium by the step pulse signal 21 output from the host device, the floppy disk device configured as described above causes the magnetic head 9 and 10 to move due to settling. Disturbed signals appear on the ten output signals 31 and 32. These signals are input to two envelope detectors 2 and become output signals 33 and 34 having waveforms as shown in FIG. The output signals 33 and 34 are input to separate sample and hold circuits 2, respectively, and are sampled and held by the monostable multivibrators 3 and 4 to which the step pulse signal 21 is input when their disturbances are stopped.

At this time, when off-tracking occurs as shown in FIG. 4, a voltage difference occurs between the output signals of the two sample and hold circuits 2. When these signals are input to the error signal generation circuit 5, the error signal generation circuit 5 determines the off-track amount based on the potential difference between them (point X in FIG. 3), and the corresponding H-bridge circuits 7 and 8 Control signals 35 and 36 for changing the current balance (V _GA and V
_GB ) are output to two FETs for changing the output currents of the H-bridge circuits 7 and 8. This changes the current balance between the two H-bridge circuits 7 and 8, and corrects off-track.

The stepper control circuit 6 receives the step pulse signal 21 and the direction signal 24 output from the host device and outputs an excitation pattern of the stepper motor.
The correspondence between the excitation pattern and the track is determined by the relationship as shown in FIG.

〔The invention's effect〕

As described above, the floppy disk device of the present invention has an effect that when a medium recorded by another floppy disk device is mounted, the magnetic head can be automatically moved to correct off-track. Therefore,
When reading information by exchanging a recording medium with another device, there is an effect that a reduction in a time margin caused by off-track and erasure of an ID portion due to side erase can be prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a correlation diagram showing a relationship between a track output from a stepper control circuit and an excitation pattern in the embodiment of FIG.
FIG. 4 is a characteristic diagram showing the relationship between the off-track amount of the error signal generating circuit and the gate voltage of the FET in the embodiment of FIG. 1, and FIG. 4 is the position of the magnetic head and the track of the recording medium in the embodiment of FIG. FIG. 5 is a plan view showing the relationship, and FIG. 5 is a waveform diagram showing the waveform of each signal in the embodiment of FIG. 1 ... Envelope detector, 2 ... Sample hold circuit, 3
4 monostable multivibrator, 5 error signal generation circuit, 6 stepper control circuit, 7 8 H bridge circuit, 9 10 magnetic head.

Claims (1)

(57) [Claims] 1. Two magnetic heads having two read / write gaps provided by dividing one head core into two and a winding wound around each of them, and connected to each of the two magnetic heads. Two envelope detectors, a first monostable multivibrator for inputting a step pulse signal output from a host device, and a second monostable multivibrator for inputting an output signal of the first monostable multivibrator. A stable multivibrator, two sample-and-hold circuits for inputting output signals of the second monostable multivibrator and output signals of the two envelope detectors,
A stepper control circuit that inputs the step pulse signal and the direction signal output from the host device and outputs an excitation pattern of a stepper motor; an output signal of the stepper control circuit and an output signal of the two sample-and-hold circuits; An error signal generating circuit that inputs and compares two output signals of the two sample and hold circuits and outputs two control signals; and an input circuit that receives each of the two control signals and changes an output current. A floppy disk drive comprising: a plurality of FETs; and two H-bridge circuits that input output currents of the two FETs and change the output current.