JPH02254604A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent the generation of a read error for the vibration of a stepping motor by providing an output stop control circuit to stop output signals from a waveform shaping circuit and an index circuit for a definite time after a step signal input to a stepping motor control circuit. CONSTITUTION:A one-shot circuit 10 to be set according to the input of the step signal to a stepping motor control circuit 8 and to be reset after the definite time is provided. When the step signal is inputted from a step signal terminal 9, a stepping motor 7 is controlled by the stepping motor control circuit 8 according to the input signal, and the positioning to the prescribed track position of a magnetic head 1 is executed. Simultaneously, the one-shot circuit 10 is set for the definite time after the step signal input, the actions of a waveform shaping circuit 2 and an index circuit 5 are controlled by the set output, and the outputs of a read data signal and an index signal are stepped for the definite time after the step signal input. Thus, a read action in an unstable condition at the time of the vibration just after the action of the stepping motor 7 can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording/reproducing device such as a flexible disk device, and particularly to an improvement of a read data signal and index signal extraction circuit thereof.

[Prior Art] Fig. 2 is a circuit diagram showing a part of a conventional magnetic recording/reproducing device. The magnetic head (2) reads data from the medium, and the magnetic head (1)
), (3) is a read data signal terminal, and (4) is an index hole (not shown) provided in the magnetic recording medium. Resistor (4a) to detect
) and a phototransistor (4b), and (5) is an index circuit that converts the signal from the index sensor (4) into an index signal that determines the reading start position by the magnetic head (1) and outputs it.

(6) is the index signal terminal, (7) is the magnetic head (
(1) a stepping motor for moving the magnetic recording medium to a predetermined track position on the magnetic recording medium; (8) a stepping motor control circuit that controls the stepping motor (7); (9)
is a step signal terminal into which a step signal for driving the stepping motor (7) is input.

Next, the operation will be explained. First, step signal terminal (
The stepping motor (7) is controlled by the stepping motor control circuit (8) in response to the stepping signal sent to the magnetic head (1), thereby moving the magnetic head (1) and positioning it at a predetermined track position on the magnetic recording medium. In addition, the index hole of the rotating magnetic recording medium is transmitted as an optical signal to the phototransistor (4a) of the index sensor (4).
is detected by the resistor (4a) and converted into an electrical signal,
It is output as an index signal from an index signal terminal (6) through an index circuit (5). Further, the magnetic head (1) positioned at a predetermined track position of the magnetic recording medium performs reading from that track position from a position corresponding to the index signal output.

This read analog waveform signal is sent to the waveform shaping circuit (2).
The signal is pulsed and output from the read data signal terminal (3) as a read data signal.

[Problems to be Solved by the Invention] The conventional magnetic recording/reproducing device is configured as described above, and after a step signal is input and the stepping motor is operated, the magnetic head position is stabilized while the stepping motor is vibrating. Since the read data signal and the index signal were output in the previous version as well, there were problems such as inability to read the read data accurately depending on the read timing.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a magnetic recording/reproducing device in which reading errors due to vibrations of a stepping motor do not occur.

[Means for Solving the Problems] A magnetic recording and reproducing device according to the present invention includes an output stop control circuit that stops output signals from a waveform shaping circuit and an index circuit for a certain period of time after inputting a step signal to a stepping motor control circuit. It was established.

[Function] The magnetic recording/reproducing device according to the present invention transmits the read data signal from the waveform shaping circuit and the index signal from the index circuit only after a certain period of time has elapsed after inputting the step signal until the operation of the stepping motor stabilizes. Operate so that it will be done.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. 1st
The figure is a circuit diagram showing a part of an embodiment of the present invention. In the figure, (1) is a magnetic head, (2) is a waveform shaping circuit, (
3) is a read data signal terminal, (4) is an index sensor, (4a) is a resistor, (4b) is a phototransistor, (5) is an index circuit, (6) is an index signal terminal, (7) is a stepping motor, (8) is the stepping motor control circuit, (9) is the step signal terminal,
The above is similar to the conventional example.

(10) is a one-shot circuit that is set in response to the step signal input to the stepping motor control circuit (8) and reset after a certain period of time. It constitutes an output stop control circuit that stops the output signal.

Next, the operation will be explained. The analog waveform signal reproduced by the magnetic head (1) is pulsed by a waveform shaping circuit (2), and the index hole of the magnetic recording medium is connected to an index sensor (4) consisting of a phototransistor (4b) and a resistor (4a). ) is detected, converted into an electrical signal, shaped by an index circuit (5), and outputted from a read data signal terminal (3) and an index signal terminal (6), respectively. Here, when a step signal is input from the step signal terminal (9), the stepping motor control circuit (8) controls the stepping motor (7) according to the input signal, and the magnetic head (1)
is positioned at a predetermined track position. At the same time, the one-shot circuit (10) is set for a certain period of time after inputting the step signal, and the set output is used by the waveform shaping circuit (2).
) and the index circuit (5) are controlled, and the output of the read data signal and index signal is stopped for a certain period of time after the step signal is input.

In this way, the output of the read data signal and index signal is stopped for a certain period of time after the stepping motor (7) is operated by the step signal, so that unstable conditions such as vibrations immediately after the stepping motor (7) operates The read operation by the magnetic head (1) is prevented.

[Effects of the Invention] As described above, according to the present invention, the read data signal and the index signal are not output for a certain period of time after the step signal is input, so that the instability such as vibrations occurring immediately after the stepping motor is operated can be avoided. This has the effect of eliminating read malfunctions and providing a high-performance magnetic recording/reproducing device.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing a part of an embodiment of the present invention, and FIG.
The figure is a circuit diagram showing part of a conventional magnetic recording/reproducing device. In the figure, (1) is a magnetic head, (2) is a waveform shaping circuit, (3) is a read data signal terminal, (4) is an index sensor, (4a) is a resistor, (4b) is a phototransistor, (5) is the index circuit, (6) is the index signal terminal, (7) is the stepping motor, (8)
(9) is a step signal terminal, and (lO) is an output stop control circuit (one-shot circuit). The same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] A waveform shaping circuit pulses the analog waveform signal reproduced by the magnetic head and outputs read data; an index circuit detects the index hole of the magnetic recording medium and outputs an index signal; In a magnetic recording and reproducing device equipped with a stepping motor control circuit that operates a stepping motor that drives a head, output signals from the waveform shaping circuit and index circuit are stopped for a certain period of time after a step signal is input to the stepping motor control circuit. A magnetic recording/reproducing device characterized by being provided with an output stop control circuit.