JPS62138094A - Floppy disk device - Google Patents

Abstract

PURPOSE:To reduce noises with the movement of a head carriage, and to shorten a settling time by conducting deexcitation processing in which an excitation sequence is returned by one step in a short time and returned to an original state. CONSTITUTION:A control circuit 8 controlling the excitation sequence of a stepping motor is controlled so that it executes deexcitation processing, in which the excitation sequence is returned by one step in a short time and returned to an original state, at every all pulse outputs, and the resonance of the stepping motor 3 is inhibited, thus reducing noises with the drive of a head carriage. When stepping pulses are fast as 3ms-5ms, on the other hand, the device is controlled so as to execute deexcitation processing only at a first and the last, and the vibrations of the stepping motor are suppressed and the motor is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a floppy disk device that reduces noise caused by vibrations caused by the movement of a disk carriage and achieves a short setting time.

2. Description of the Related Art Hereinafter, a conventional floppy disk device will be explained with reference to the drawings.

FIG. 2 shows the head carriage of a floppy disk device. In FIG. 2, 1 is a helad carriage, 2 is a guide rail, and 3 is a step motor. The operation of the 20 disk drive having the above configuration will be explained below. The head carriage is attached to a step motor 3 via a steel belt 4. When the step signal that drives the head is input to the step motor, the step angle of the motor changes by the number of step signals, and the head carriage moves back and forth on the guide rail to the target track.

As shown in Figure M8, a step pulse input circuit 5 and a step motor sequence output circuit 6 for changing the excitation voltage are connected to the step motor, and the excitation voltage is changed by the number of step pulses to rotate the motor.

FIG. 9 shows a bipolar motion sequence of two-phase excitation. When the step pulses are input to the step pulse input circuit 6, the excitation voltage of the motor changes as shown in the figure for each pulse and is output from the sequence output circuit 6 to the excitation coil of the motor.

For each change in the excitation voltage, the angle of the motor changes by one step. In this way, the step motor can only move in a stepwise manner, and its motion is vibratory.

FIG. 4 shows the displacement of the head carriage when the head carriage advances by one step, with time on the horizontal axis and displacement on the vertical axis. The head carriage driven by the step motor as described above reaches a certain target position, vibrates, and then stops. If the rate at which the step signal is sent is slow (usually 5m3 or more), the head will overshoot by △e (point A in Figure 4).
Since the excitation is switched to the next one, the head carriage moves to the final track while vibrating each track as shown in FIG. 1o.

Problems to be Solved by the Invention However, since the head carriage also vibrates via the steel belt, this vibration is transmitted through the guide rail and vibrates the frame, resulting in the problem that noise is generated as the head carriage moves. Was. On the other hand, when the step signal is fast, such as 3 mS, the next excitation occurs before overshoot (point B in Figure 4), so the step motor rotates relatively smoothly, but as shown by the solid line in Figure 7. Another drawback is that the 1 is still accompanied by vibration after moving to the final track, and the settling time is long until reading/writing is possible (/c).

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention provides a floppy disk device that can reduce noise caused by movement of a head carriage and reduce centering time.

Means for Solving the Problems In order to achieve this object, the flow and nobby disk device of the present invention includes a circuit for measuring step pulses and a 7-ken excitation voltage for the step motor for driving the head carriage. When the interval between step pulses is close to the resonant frequency of the step motor, the excitation sequence is returned one step for a short period of time, and the excitation sequence is returned to the original state. The motor is configured to control the motor so that the reverse excitation process is performed only at the first and last steps if the process is fast.

Effect: With this configuration, when driving with step pulses close to the frequency at which vibrations occur in the motor, the sequence control circuit performs all reverse excitation processing, which controls the excitation sequence to return one step for a short time and then return to the original state. Since this is done in steps and the resonance of the step motor is suppressed, the noise associated with driving the head carriage is reduced.

In addition, when the step pulse is fast, reverse excitation processing is performed only at the beginning and end, so the device starts moving smoothly and stops with less vibration, resulting in a shorter settling time.

EXAMPLE An example of the present invention will be described below with reference to the drawings. FIG. 1 shows a circuit connected to a step motor 3 for driving a head carriage 1 shown in FIG. 2 of a floppy disk device according to an embodiment of the present invention. This circuit consists of a step pulse reading circuit (hereinafter referred to as a reading circuit) 7 that measures step pulses and a step motor sequence output circuit (hereinafter referred to as an output circuit) that generates a sequence excitation voltage for a step motor for driving a helad carriage. )9 and sequence control through step sequence control circuit (
(hereinafter referred to as a control circuit).

Regarding the operation of the floppy disk device with the above configuration,
This will be explained below. Head carriage 1 has steel belt 4
It is attached to the step motor 3 via. When the step signal that drives the head is input to the step motor 3, the step motor 3 changes the step angle and the angle by the number of step signals, and the head carriage 1
moves to the desired trunk. Now, when a step pulse is input to the reading circuit 7, the reading circuit 7 measures the interval between the step pulses using the first two step pulses. When the step motor moves in an oscillatory manner at a slow interval of more than ems, the
The excitation of the step motor is controlled by the control circuit 8 as in the sequence. That is, when the second pulse is input, the first excitation changes after a short time delay for determination and preprocessing. Then, after a time ts, the excitation is changed to tm before the second excitation changes.
After reversing the time, reverse excitation is performed to return to the original excitation. This is done for each step pulse. By doing this, the step motor is energized when it is about to overshoot, as shown by the dotted line in Figure 4, so the brake is applied and the motor is displaced without vibration. .

Therefore, as shown in FIG. 5, the head carriage moves to the last track without vibrating from track to track.

On the other hand, the interval between step pulses is short. That is, during a fast head seek, since no vibration occurs during inter-track movement, the control circuit performs reverse excitation processing only during the first and last steps as shown in FIG. Therefore, the head carriage stops immediately after reaching the target track as indicated by the dotted line in FIG. That is, the centering time becomes shorter.

As described above, according to this embodiment, when the excitation sequence of the step motor is driven by step pulses close to the frequency at which vibrations of the motor occur, the control circuit 8 that controls the sequence changes the excitation sequence in one short step. The reverse excitation process of returning and returning to the original state is controlled to be performed for every pulse output, suppressing the resonance of the step motor, thereby reducing the noise associated with driving the head carriage. On the other hand, the step pulse is 3
When the speed is fast, such as from mS to sms, the step motor is controlled to perform reverse excitation processing only at the beginning and end, thereby suppressing vibration and stopping the step motor.

Therefore, there is an effect of reducing the time required for stable reading after head seek, that is, the settling time.

Effects of the Invention The present invention is composed of a circuit for measuring step pulses, a circuit for generating a sequence excitation voltage for a step motor to drive a head carriage, and a circuit for controlling the sequence. When driving with step pulses close to the frequency at which motor vibration occurs, the circuit that controls the sequence returns the excitation sequence one step for a short time and then returns it to the original state.The circuit controls the excitation sequence so that it performs reverse excitation processing for every step pulse. However, since the resonance of the step motor is suppressed, the noise associated with the movement of the head carriage can be reduced. In addition, when the step pulse is fast, only the first and last step outputs are reversely excited, and after reaching the target track, they are quickly stopped, making it possible to shorten the settling time. This makes it possible to realize an excellent floppy disk device.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a drive circuit for a step motor of a floppy disk device in an embodiment of the present invention;
Figure 2 is a configuration diagram showing the Herad carriage, Figure 3 is a timing chart showing the drive sequence of the step motor when the step pulse is slow, Figure 4 is a characteristic diagram showing the step response circuit of the step motor, and Figure 6 is a diagram showing the step motor drive sequence when the step pulse is slow. Figure, 7th
The figure is a response characteristic diagram of the Herad carriage, Figure 6 is a timing chart showing the step motor drive sequence when the step pulse is fast, Figure 8 is a block diagram of a conventional drive circuit, and Figure 9 is a two-phase step motor drive sequence. Timing chart showing the bibo 2 drive sequence of the ping motor, 1st
FIG. 0 is a characteristic diagram showing the response of a conventional Herad carriage. 1... Head carriage, 3... Step motor, 7... Step pulse reading circuit, 8... Step sequence control circuit, 9...・Step motor sequence output circuit. Figure 1. Ward. , Meditation＼ Fig. 5 埒 r etζ imitation 0 Fig. 6 Z34s6 Fig. 7 Fig. 8 Fig. 9

Claims (1)

[Claims] It is equipped with a circuit that measures step pulses, a circuit that generates a sequence excitation voltage for the step motor to drive the head carriage, and a circuit that controls the excitation sequence. When the interval between step pulses is short, the floppy disk device performs all the reverse excitation processing to return the excitation sequence one step to the original state, and when the interval between step pulses is fast, the reverse excitation processing is performed only on the first and last outputs.