JPH05314645A - Rotation driving device - Google Patents

Abstract

PURPOSE:To always impart an optimum characteristic to the revolving speed of a motor and to obtain high rotation accuracy of each revolving speed. CONSTITUTION:By a frequency divider means 3, a reference signal 4 deciding the revolving speed of the motor 14 is generated from a clock signal 1 and a recording mode switching signal 2. By a speed comparator means 5, a speed signal 7 from a speed detection means 6 is compared with the reference signal 4 and the error signal 8 of the difference is outputted. By an integral filter means 9, the error signal 8 is converted to a control signal 10 by switching the frequency characteristic of the error signal by the recording mode switching signal 2. By a drive torgue control means 11, a torgue command signal 12 is generated based on the control signal 10 and by a motor drive means 13, the motor 14 is rotated properly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary drive device for a magnetic recording medium for FDD (floppy disk drive).

[0002]

2. Description of the Related Art Conventionally, a rotational driving device for a magnetic recording medium for an FDD of this type has a rotational speed for switching the rotational speed of a motor in response to a recording mode switching signal, as disclosed in Japanese Patent Laid-Open No. 60-87405. A switching unit is provided, and writing or reproduction for a plurality of recording modes can be performed by switching the rotation speed of the motor.

[0003]

However, in the conventional rotary drive device for a magnetic recording medium for FDD, only the rotational speed of the motor is switched, so that the control constant cannot always take an optimum value with respect to the rotational speed. However, there is a problem that high rotation accuracy cannot be obtained for each rotation speed.

The present invention solves such a conventional problem, and provides a rotary drive device for a magnetic recording medium for an FDD, which can always provide optimum characteristics with respect to the number of rotations and can obtain high rotation accuracy. The purpose is to provide.

[0005]

In order to achieve the above object, the present invention provides a rotation speed switching means for switching the rotation speed in response to a recording mode switching signal and a control constant in response to the recording mode switching signal. A control constant switching means capable of switching is provided, and the control constant is switched at the same time when the rotation speed is switched.

[0006]

Therefore, according to the present invention, since the control constant is switched at the same time as the rotational speed by the recording mode switching signal, the optimum control corresponding to the switching of the rotational speed can be obtained. It has the effect of improving the number.

As a result, the jitter of the write or read signal in the recording or reproducing of the FDD can be reduced, and a highly reliable FDD with few errors can be obtained.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the configuration of an embodiment of the present invention. In FIG. 1, 1 is a clock signal, 2 is a recording mode switching signal, 3 is frequency dividing means for generating a reference signal 4 of the number of rotations of the motor 14 from the clock signal 1, and the frequency dividing number is the recording mode switching signal 2. Can be switched by. Reference numeral 5 is a speed comparison means, which compares the speed signal 7 detected by the speed detection means 6 for detecting the rotation speed of the motor 14 with the reference signal 4 and outputs an error signal 8. The frequency dividing means 3, the speed comparing means 5, and the speed detecting means 6 constitute the rotation speed switching means of the present invention. Reference numeral 9 is an integral filter means corresponding to the control constant switching means of the present invention for converting the error signal 8 into a control signal 10, which has a frequency characteristic with respect to the error signal 8. This frequency characteristic can be changed by switching a plurality of preset control constants that determine the motor control characteristic according to the recording mode switching signal 2. Reference numeral 11 is a drive torque control means, which is a control signal 1
According to 0, the torque command signal 12 is output to the motor driving means 13. The motor driving means 13 applies a torque according to the torque command signal 12 to the motor 14 to apply the torque to the motor 14.
To rotate.

FIG. 2 shows the structure of the integral filter means 9.
Of. 21 is a logic circuit for switching the recording mode
Signal 2 is input. The output of the logic circuit 21 is
The parallel signal terminal A₁~ A₆Switch connected to
Circuit group S₁~ S₆Entered in. 22 corresponds to the error signal 8
With the operational amplifier that determines the frequency characteristic of the control signal 10
Yes, control constant R that sets the characteristic₁₁, R₁₂, R₂，
C₁₁, C₁₂, C_{twenty one}, C _{twenty two}Is a switch circuit group S₁~ S₆of
Connected to each switch.

Next, the operation of the above embodiment will be described.
In FIG. 1, the frequency dividing means 3 first generates a reference signal 4 for determining the number of rotations of the motor 14 by switching the number of frequency dividing stages from the clock signal 1 by the recording mode switching signal 2. Next, the speed comparison means 5 detects the rotation speed of the motor 14, and the speed signal 7 and the reference signal 4 from the speed detection means 6 are detected.
Are compared with each other, and the error signal 8 of the difference is input to the integration filter means 9. The integral filter means 9 converts the error signal 8 into the control signal 10 by switching the frequency characteristic by the recording mode switching signal 2, and the drive torque control means 11 uses the torque command signal 1 based on the control signal 10.
2 is generated, and the motor drive means 13 causes the motor 14 to rotate properly by the torque command signal 12.

Next, the operation of the integral filter means 9 will be described. In FIG. 2, when the recording mode switching signal 2 switches to H or L, the logic circuit 21 outputs a parallel signal to the parallel signal terminals A1 to A6 according to the correspondence table of (Table 1). The switch circuit groups S1 to S6 switch the control constants as shown in (Table 2) by turning on and off according to the parallel terminals A1 to A6.

[0012]

[Table 1]

[0013]

[Table 2]

FIG. 3 shows control characteristics when the motor 14 of the conventional example and the motor of the above-described embodiment are driven at two different rotational speeds. Here, the vertical axis represents the rotational fluctuation with respect to the disturbance torque, and the horizontal axis represents the frequency. As is clear from FIG. 3, it can be said that the higher the characteristic curve is, the lower the control characteristic is, and that the above-mentioned embodiment exhibits superior characteristics to the conventional example.

As described above, according to the above-described embodiment, the optimum control constants for each rotational speed are set in advance in the integral filter means 9, and these are switched in response to the recording mode switching signal 2 so that they are always switched. An optimum control constant can be given to the rotation speed, and high rotation accuracy can be obtained for each rotation speed.

[0016]

As is apparent from the above embodiment, the present invention makes it possible to switch the control constant at the same time as the rotation speed is switched in response to the recording mode switching signal. Since the optimum control characteristics can be obtained, the jitter of the write or read signal at the time of recording and reproducing in each recording mode can be reduced, and the rotation driving device of the magnetic recording medium for FDD with less error occurrence and high reliability. Can be realized.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of a rotation drive device for a magnetic recording medium for FDD showing an embodiment of the present invention.

FIG. 2 is a circuit diagram of a main part of an integration filter means in the device.

FIG. 3 is a characteristic diagram for comparing characteristics of a conventional example and an example.

[Explanation of symbols]

1 clock signal 2 recording mode switching signal 3 frequency dividing means 4 reference signal 5 speed comparing means 6 speed detecting means 7 speed signal 8 error signal 9 integration filter means 10 control signal 11 driving torque control means 12 torque command signal 13 motor driving means 14 Motor 21 Logic circuit 22 Operational amplifier A _{1 to} A ₆ Parallel signal terminal S _{1 to} S ₆ Switch circuit group R ₁₁ , R ₁₂ , R ₂ , C ₁₁ , C ₁₂ , C ₂₁ , C ₂₂ Control constant

Claims (1)

[Claims] 1. A magnetic recording for FDD, comprising rotation speed switching means for switching the rotation speed of a motor in response to a recording mode switching signal and control constant switching means for switching a control constant in response to the recording mode switching signal. Medium rotation drive.