JPH0612779A - Floppy disk device - Google Patents

Abstract

PURPOSE:To improve reliability, to miniaturize an electric circuit and to reduce cost by making an oscillator for a spindle motor and the oscillator for controlling a mechanism in common. CONSTITUTION:A frequency output circuit 30 for the spindle motor generating a signal having a necessary frequency for the spindle motor from a frequency divider circuit part 4 and the output terminal 31 of the circuit 4 are provided in an LSI for controlling the mechanism, and a frequency signal necessary for a frequency divider circuit part 20 in the LSI 13 for the spindle motor is supplied. That is, when power source is supplied to a floppy disk device, the oscillator oscillates. In the circuit 30, the frequency equal to that of the oscillator 27 for the spindle motor is made from the output of the frequency divider circuit 4 and supplied to the frequency divider circuit part 20 of the LSI 13. Thus, the signal is supplied to two pieces of LSIs by one piece of oscillator and then reliability is improved and the cost, as well is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a floppy disk device used for an external storage device such as a personal computer and a word processor.

[0002]

2. Description of the Related Art Conventionally, a floppy disk device of this type has a mechanism control circuit, a spindle motor circuit, and two oscillators for each circuit.

First, the mechanism control circuit will be described. FIG. 2 is a block diagram when the mechanism control circuit 1, the R / W analog circuit 2, and the stepping motor driver circuit 3 are integrated in one LSI. The mechanism control circuit 1 is roughly divided into 6 parts. Frequency divider circuit 4, I / O signal section 5,
An R / W signal section 6, a step signal section 7, and a spindle motor signal section 8. The mechanism control circuit 1 takes in a signal of a specific frequency output from the mechanism control oscillator 9 outside the LSI, and generates a clock required in each circuit in the frequency dividing circuit unit 4. The I / O signal section 5 processes an interface signal 10 with a system such as a computer or a word processor and various sensor signals 11 in the floppy disk drive, and an R / W signal section 6, a step signal section 7,
Signals are exchanged with the spindle motor signal unit 8 and signals for operating the mechanism of the floppy disk device are produced. The R / W signal unit 6, the step signal unit 7, and the spindle motor signal unit 8 respectively use the clock generated in the frequency dividing circuit unit 4 to read the R / W analog circuit 2, the stepping motor driver circuit 3, and the spindle motor, respectively. Signals are exchanged with the dedicated LSI 13.

Next, the spindle motor circuit will be described.
3 is a sectional view of the spindle motor, and FIG. 4 is a constant speed control circuit diagram of the spindle motor. In the spindle motor circuit, the constant speed control is related to the oscillator signal. There are several methods for detecting the rotation speed of the spindle motor, but the FG coil 14 is used here. When the spindle motor is rotating, the FG coil 14 detects a change in the magnetic field generated by the FG magnet 16 attached to the rotor 15, and the FG signal processing unit 23 converts the change in the magnetic field into a signal. On the other hand, spindle motor oscillator 2
From the output signal of No. 7, the frequency selection signal 2
The frequency signal corresponding to the rotation speed selected in 9 is taken out,
The speed comparison unit 21 compares the current rotation speed with the target rotation speed. Based on the result and the phase information from the Hall element 28, the matrix 22 determines the amplification factor of the output amplifier 26, and the current flowing through the stator coil 17 is changed.
Control the number of rotations.

The conventional circuit requires two oscillators respectively dedicated to the mechanism control circuit 1 and the spindle motor circuit, resulting in a circuit as shown in FIG.

[0006]

However, in the above-mentioned conventional circuit, since the number of parts on the substrate is large, there are limits to miniaturization of the electric circuit and improvement of reliability.

The present invention solves the above-mentioned conventional problems, and in addition to downsizing an electric circuit and improving reliability,
It is an object of the present invention to provide a floppy disk device that can reduce costs by reducing the number of parts.

[0008]

In order to achieve the above object, the present invention provides a spindle motor frequency output circuit for producing a frequency signal required for a spindle motor from a frequency dividing circuit section in a mechanism control circuit, It is configured to supply a signal of a required frequency to the frequency dividing circuit section in the motor constant speed control circuit.

[0009]

With the above-described structure, the present invention operates so that the spindle motor oscillator can be substituted with the spindle motor frequency generated by the frequency dividing circuit means in the mechanism control circuit.

[0010]

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

FIG. 1 is a block diagram showing the configuration of a floppy disk device according to an embodiment of the present invention. As shown in FIG. 1, a frequency output circuit 30 for the spindle motor that produces a signal having a frequency required for the spindle motor from the frequency dividing circuit unit 4 and an output of the frequency output circuit 30 for the spindle motor are drawn to the mechanism control LSI. There is provided a spindle motor frequency output terminal 31 for supplying a signal of a required frequency to the frequency dividing circuit section 20 in the spindle motor LSI 13. That is, when the floppy disk device is powered on, the oscillator starts oscillating. In the spindle motor frequency output circuit 30, a frequency equal to that of the spindle motor oscillator 27 is created from the output of the frequency dividing circuit unit 4 and supplied to the frequency dividing circuit unit 20 of the spindle motor LSI 13.

As described above, according to this embodiment, a single oscillator can supply a signal to two LSIs, so that the reliability can be improved and the cost can be reduced.

[0013]

As is apparent from the above embodiment, the present invention shares the spindle motor oscillator and the mechanism control oscillator with each other, so that the reliability is improved and the electric circuit is downsized.
It is possible to provide a floppy disk device having effects such as cost reduction.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a floppy disk device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a conventional mechanism control circuit and its periphery.

FIG. 3 is a sectional view showing a structure of a spindle motor.

FIG. 4 is a block diagram showing a configuration of a conventional constant speed control circuit for a spindle motor.

FIG. 5 is a block diagram showing a configuration of a conventional floppy disk device.

[Explanation of symbols]

 30 Spindle motor frequency output circuit

Claims (1)

[Claims] 1. A frequency output for a spindle motor which generates a signal for controlling a spindle motor from an output signal of a frequency dividing circuit section in a mechanism control circuit and supplies the signal to a frequency dividing circuit section in a spindle motor constant speed control circuit. Floppy disk drive with circuit.