JPH06111499A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To provide a device with little dumping amount by properly selecting timing for impressing a brake pulse matching with a using stepper motor. CONSTITUTION:A step signal and a direction signal from a system side are inputted to an intermediate value pulse and a phase pulse generation circuit 30 in a device side, and the signal containing the step signal and two kinds of phase signals is generated. The signal 32 is inputted to a brake pulse generation circuit 40, and the brake pulse (BP) is generated matching with timing of overshoot of a carriage after a prescribed time elapses whenever the excitation phase of respective phase pulses of the signal 32 is switched. On the other hand, the signal 32 is inputted to a counter 50, and a permission pulse signal 52 selected by a time setting switch 54 according to the characteristic of the stepper motor is outputted to a switch 48, and the passage of the BP is permitted. By an adding circuit 41, the BP and the signal 32 are added and supplied to the stepper motor 20, and the brake operation is executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device, and more particularly to improvement of a drive system of a stepper motor in the magnetic disk device.

[0002]

2. Description of the Related Art In the conventional stepper motor drive system, an external step pulse signal is first fetched from a system into a signal processing device in a magnetic disk device such as a floppy disk device. In this signal processing device, an intermediate value close to approximately the middle between consecutive step pulse signals from the outside is calculated. A stepper motor drive pulse (excitation phase switching pulse) is generated from this intermediate value signal and an external step pulse signal. Further, the stepper motor drive pulse output from the signal processing device is input to a drive device that drives the stepper motor, and the stepper motor is driven by the output from this drive device.

In order to suppress the damping amount of the stepper motor, a patent application (patent application No.
The invention described in (Reference No. 2202002) proposes to add a brake pulse (reversal pulse) generated in synchronization with the timing of the occurrence of the overshoot of the carriage after the generation of the intermediate value pulse to the phase pulse. is doing.

However, when stepper motors having different characteristics are used, the timing effective for damping is naturally delayed, so that the effect of suppressing the damping amount is reduced and the damping amount may be increased. Furthermore, when the seek operation is performed in a relatively short time such as 3 ms or 4 ms with a continuous step interval, there is almost no damping even if a stepper motor with different characteristics is used, and seek noise is a problematic value. However, when seeking is performed in such a relatively short time, if the brake pulse is added to the phase pulse to drive the stepper motor,
Similar to the above, the damping amount increases and seek noise also increases.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a magnetic disk drive with a small amount of damping by appropriately selecting the timing for applying a brake pulse according to the stepper motor used.

[0006]

In order to achieve the above-mentioned object, the present invention is a magnetic disk apparatus which seeks a recording head on a magnetic disk to perform recording and reproduction, and drives a stepper motor for seeking. Phase pulse generating means for generating a phase pulse for generating, a brake pulse generating means for receiving a phase pulse from the phase pulse generating means to generate a brake pulse, and a phase pulse from the phase pulse generating means are input. Generating a permission pulse signal, a time setting switch for setting the counting time of the counter, a switch for permitting passage of a brake pulse by the permission pulse signal from the counter, a brake pulse passing through the switch and a phase Adding means for adding the phase pulse from the pulse generating means It is to employ a magnetic disk apparatus characterized by having.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described with reference to the drawings. FIG. 1 is a side view of the main part of the magnetic disk device. In FIG. 1, the carriage on which the magnetic head 12 and the shield plate 16 are mounted is guided along a lead screw 14 rotated by a stepper motor 20. The shielding plate 16 is used for the magnetic head 12 mounted on the carriage 10.
When the track 00 position of a recording medium such as a floppy disk is reached, the track 00 sensor is operated and a track 00 position signal indicating the track 00 position is output.

FIG. 2 is a circuit block diagram of an embodiment of the present invention, and FIG. 3 is a detailed circuit block diagram of the intermediate value pulse / phase pulse generating circuit in the circuit block diagram of FIG. 4 is a waveform diagram of the step signal, the phase A signal, and the phase C signal, and FIG. 5 is a graph showing the displacement amount of the carriage. As shown in FIG. 2, the circuit block according to the embodiment of the present invention includes an intermediate value pulse / phase pulse generation circuit 30, a brake pulse generation circuit 40, a counter 50, a switch 48, an addition circuit 41, and a driver 44. It consists of and. A step signal and a direction signal are supplied from the system side to a magnetic disk device side such as a floppy disk drive (FDD).
The step signal and the direction signal are input to the intermediate value pulse / phase pulse generation circuit 30. In the intermediate value pulse / phase pulse generation circuit 30, the step signal which is the intermediate value pulse signal, the phase A signal, and the phase C signal are input.
A signal is generated.

More specifically, as shown in FIG. 3, the intermediate value pulse / phase pulse generating circuit 30 receives an intermediate value when a step signal (specifically, a step a signal) (see FIG. 4) is input. Pulse signal (specifically, step b
Signal) (see FIG. 4) for generating an intermediate value pulse generation circuit 3
4, an adder circuit 35 for adding the step a signal and the generated step b signal, and an output from the adder circuit 35 and a direction signal from the system are input to generate a phase A signal and a phase C signal (see FIG. 4). And a phase pulse generating circuit 36 for

FIG. 5 shows a comparatively long step time of 5 ms or 6 ms when the carriage is moved by the phase signal as shown in FIG. 4 using the magnetic disk device having the structure shown in FIG. It shows the amount of displacement with respect to time of the carriage measured by the reflection type optical measuring means when the carriage is moved over. As shown in FIG. 5, the carriage is displaced from the movement start position toward the target position, but does not move linearly by switching the excitation phase of the phase pulse, but has a substantially staircase shape with a turnback portion. It is a move. That is, every time the intermediate value pulse is generated, the carriage overshoots after the time when the intermediate value pulse is generated.

Referring again to FIG. 2, the signal 32 including the phase A signal and the phase C signal generated by the intermediate value pulse / phase pulse generating circuit 30 is input to the brake pulse generating circuit 40, and the brake pulse generating circuit 40. Four
0 generates a brake pulse (reverse pulse). The brake pulse is signal 32 (phase A signal, phase C
Each time the excitation phase of each phase pulse of the (signal) is switched, it is generated at the timing of the overshoot of the carriage after the elapse of a predetermined time from the switching. On the other hand, the signal 32 is input to the counter 50 and the counter 50
Outputs the permission pulse signal 52 in synchronization with the timing of the preset carriage overshoot from the switching of the excitation phase (prior to the generation of the brake pulse). The counter 50 is provided with a time setting switch 54 for setting the counting time corresponding to the characteristics of different stepper motors used. The permission pulse signal 52 selected by the time setting switch 54 is input to the switch 48 to permit passage of the brake pulse generated by the brake generation circuit. The brake pulse passed through the switch 48 and the signal 32 are input to the adder circuit 41, and are added by the adder circuit 41 to form a drive signal 42, which is supplied to the stepper motor 20 through the driver 44. Since the drive signal 42 includes the brake pulse as described above, the braking operation is performed at the timing of the overshoot of the carriage.

[0012]

As described above, according to the present invention,
Brake operation can be performed at the timing of overshoot of the carriage when a stepper motor is used differently, and brake operation is performed when a seek operation of a relatively short time such as 3 ms or 4 ms is performed. It was designed so that it would not exist.

[Brief description of drawings]

FIG. 1 is a side view of a main part of a magnetic disk device.

FIG. 2 is a circuit block diagram of an embodiment of the present invention.

FIG. 3 is a detailed circuit block diagram of an intermediate value pulse / phase pulse generation circuit in the circuit block diagram of FIG.

FIG. 4 is a waveform diagram of a step signal, a phase A signal, and a phase C signal.

FIG. 5 is a graph showing a displacement amount of a carriage.

FIG. 6 is a waveform diagram of a step signal, a phase A signal, and a phase C signal. FIG. 7 is a waveform diagram of a phase A signal and a phase C signal.

[Explanation of symbols]

 10 carriage 12 magnetic head 14 lead screw 16 shield plate 18 track 00 sensor 20 stepper motor 30 intermediate value pulse / phase pulse generation circuit 34 intermediate value pulse generation circuit 36 phase pulse generation circuit 40 brake pulse generation circuit 50 counter 48 switch 52 time setting switch

Claims (3)

[Claims] 1. A magnetic disk device for performing recording / reproducing by seeking a recording head on a magnetic disk, and phase pulse generating means for generating a phase pulse for driving a stepper motor for seeking, and the phase pulse. Brake pulse generating means for receiving a phase pulse from the generating means to generate a brake pulse, a counter for receiving a phase pulse from the phase pulse generating means to generate a permission pulse signal, and setting a counting time of the counter A time setting switch, a switch for permitting passage of a brake pulse by a permission pulse signal from the counter, and an adding means for adding the brake pulse passing through the switch and the phase pulse from the phase pulse generating means. Characteristic magnetic disk device. 2. The magnetic disk device according to claim 1, wherein the brake pulse is generated after the time when the intermediate value pulse is generated. 3. The magnetic disk device according to claim 1, wherein the setting of the counting time by the time setting switch is determined by the characteristics of the stepper motor.