JPH0241695A - Motor controller for driving information recording disk - Google Patents

Abstract

PURPOSE:To reduce the title controller in size and cost by utilizing an FG (frequency generator) frequency divider for generating a drive signal for rotating a motor in the divider to generate a servo gate signal. CONSTITUTION:A FG signal (d) is divided in frequency by a predetermined frequency division ratio in a FG frequency divider 16, and set by an index signal (c) to generate a driving signal (e). A driving current is switched and fed to 4-phase driving coils 6 in a brushless motor driving circuit 17 on the basis of a driving signal (e), thereby rotatably driving a driving magnet 5. The signal (e) is also supplied to a servo gate signal generator 18 to become a servo gate signal (j) corresponding to the rising edge. Since the rising and falling edges of the signal (j) respectively correspond to the starting and ending points of a servo sector 3 on a magnetic disk 1, a timing for recording/reproducing a servo signal on the sector 3 is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a control device for an information recording disk drive motor used in an information recording disk device.

(Prior Art) In recent years, information recording disk devices such as magnetic disk devices have been widely used.

In this magnetic disk device, the timing at which a servo signal, which is a signal for controlling a magnetic head for recording and reproduction, is recorded and reproduced by a servo sector provided between data sectors on concentric recording tracks of a magnetic disk by this magnetic head is determined. A servo gate signal is required to obtain the magnetic disk, and this servo gate signal may be obtained from the motor for driving the magnetic disk.

FIG. 3 is a block diagram showing an example of a conventional control device for driving an information recording disk, and FIG. 4 is a waveform diagram illustrating the operation of the device shown in FIG. This conventional example is an example of a motor control device for driving a magnetic disk.

As shown in FIG. 3, on concentric recording tracks 2 on the surface of the magnetic disk 1, there are data sectors 4 for recording and reproducing information signals, and servo signals that are signals for controlling the magnetic head for recording and reproducing. Eight servo sectors 3 for recording and reproduction are alternately formed.

This magnetic disk 1 is coaxially and directly connected to the rotor of a drive motor, and is rotationally driven by this rotor.

A four-pole drive magnetic pole 5 formed on a disc-shaped drive magnet disposed on the rotor, a four-phase drive coil 6 facing the drive magnetic pole 5 disposed on the stator, and a drive r
Two Hall elements 19 arranged at an electrical angle of 90° for detecting the position of the pole 5 constitute a motor section 9. Based on the drive magnetic pole position detection signal of one Hall element, the brushless motor drive circuit By switching the drive current to the four-phase drive coil 6 at 2°, the drive magnet is rotationally driven.

In addition, the motor has a frequency generator Km (
(hereinafter abbreviated as FC) and a pulse generator for rotational phase detection (hereinafter abbreviated as PG).

That is, 16 FG magnetic poles 7' formed in a ring-shaped FG magnet arranged around the outer periphery of the driving magnet,
An FG head 8', which is a magnetoelectric conversion element for generating a rotational speed signal, faces the FG magnetic pole 7' disposed on the stator.
This FG is constituted by a unipolar PG] I9 formed on a PG magnet placed near the outer periphery of the rotor;
This PG is constituted by a PG head 10, which is a magnetoelectric conversion element for generating rotational position signals, arranged on the stator.

As the rotor rotates, the PG magnetic pole 9 is ejected from the PG head 10 once per rotation of the rotor at each rotational angle in which it faces the PC head 10, as shown in FIG.
) is generated, and this PG output a is supplied to the waveform shaping port 1i411 as shown in FIG.
This PG output a is waveform-shaped by this waveform shaping circuit 11 and becomes an index signal C as shown in FIG. 4(C), which is supplied to a constant speed/constant phase control circuit 13' as shown in FIG. .

On the other hand, from the FG rotor 8', an FG output b as shown in FIG. is supplied to a waveform shaping circuit 12' as shown in FIG. In this waveform shaping circuit 12', this PG output b is
The waveform is shaped into a rectangular wave as shown in Figure 4 (D) and the FG
The signal d' is supplied to the constant speed/constant phase control circuit 13' as shown in FIG. In this constant speed/constant phase control circuit 13', a constant speed/constant phase side # signal, which is a signal for controlling this rotor to a constant speed/constant phase, is generated based on the FG signal d' and the index signal C. and is supplied to the brushless motor drive circuit 20. In this brushless motor drive circuit 20, by adjusting the drive current flowing through the drive coil 6 based on this constant speed/constant phase control signal, a loop that negatively feedbacks the speed and phase is formed in this motor as described above. Therefore, this rotor is controlled at constant speed and constant phase.

Further, the index signal C and the FG signal d' are also supplied to the servo gate signal generation circuit 21.

In this servo gate signal generation circuit 21, this FG signal d' is reset by this index signal C, and as position information with respect to the rotational direction, a servo gate as shown in FIG. The signal becomes j. The timing of this servo gate signal j corresponds to the servo sector 3 on the magnetic disk 1, and the falling and rising edges of this pulse j correspond to the starting point and ending point of this servo sector 3, respectively. However, this servo gate signal j provides the timing for recording and reproducing the servo signal in the servo sector 3 by the recording and reproducing magnetic head, as described above.

In the above description of the conventional example, in order to simplify the explanation, the case where the number of servo sectors is 8 per recording track is explained, but in reality, 17, 34, etc. are used. This also applies to other examples described later.

Also, the above FG is the FG ratio output pulse number or 8 per rotation.
Although we have explained an example in which the number of servo sectors in the cycle is the same as the above, the controllability of constant speed III control of the motor is better as the number of FG specific output pulses increases, so the number of pulses per one rotation of this FG specific output is: 2 of this servo sector number
In some cases, more than twice as many people are selected. In this case, this FG ratio output is frequency-divided by a frequency dividing circuit provided in the servo gate generation circuit 21, and the same number of servo gate signals as the number of servo sectors are generated.

In addition, although the above-mentioned motor has been described as an example of a so-called Hall brushless morph in which the drive current is switched and passed through the drive coil 6 based on the drive magnetic pole position detection signal of the Hall element 19, this drive as shown in FIG. BACKGROUND ART A so-called sensorless type brushless motor that does not include a Hall element for detecting a magnetic pole position is known.

FIG. 5 is a block diagram showing an example of a conventional sensorless brushless motor control device, and FIG. 6 is a waveform diagram illustrating the operation of the device shown in FIG.

As shown in FIG. 5, a four-pole drive magnetic pole 5 formed on a disc-shaped drive magnet placed on the rotor, and a four-phase drive coil 6 facing the drive wJ magnetic pole 5 placed on the stator. constitutes the motor section.

Furthermore, a 32-pole FG magnet f! is formed in a ring-shaped FG magnet placed around the outer periphery of the drive magnet. 7 and an FG head 8, which is a magnetoelectric conversion element for generating a rotational speed signal, and which faces the FGG pole 7 arranged on the stator.
G, S, PG arranged near the outer periphery of the rotor;
A PG is composed of a single PC magnetic pole formed on a magnet and a PG head 10, which is a magneto-electric conversion element for generating rotational position signals, arranged on the stator.

As the rotor rotates, the rad 10 is applied to this PG.
Once per rotation of the rotor, a PG ratio output as shown in FIG. The signal is supplied to the waveform shaping circuit 11 as shown in FIG.

This PG ratio output is waveform-shaped by this waveform shaping circuit 11 and becomes an index signal C as shown in FIG. and the FGG circuit 16.

On the other hand, the FG head 8 generates an FG ratio output as shown in FIG. The signal is supplied to the waveform shaping circuit 12 as shown in FIG.

This FG ratio output in this waveform shaping circuit 12 is as shown in FIG.
), the waveform is shaped into a rectangular wave as shown in FIG. be done.

In this motor, the function of one Hall element for detecting the driving magnetic pole position of the Hall brushless morph shown in FIG. 3 is performed by the oscillation starting circuit 15 and the FGG circuit 16 shown in FIG.

When the rotor is stopped, the start i recognition circuit 14 closes the switch SW1 and opens the switch SW2, so a start signal generated from the oscillation start circuit 15 is supplied to the brushless motor drive circuit 17. Based on this activation signal, the brushless motor drive circuit 17 switches a drive current to flow through the four-phase drive coil 6, thereby rotationally driving the drive magnet.

Then, based on the FG damage signal, the activation confirmation circuit 1
After confirming that the rotor has reached a predetermined rotation speed by the action of step 4, open the switch SWI and switch SW2.
By closing, the output of the FGG circuit 16 is supplied to the brushless motor drive circuit 17. This FG
In the frequency dividing circuit 16, this FG signal d is frequency-divided by a predetermined frequency division ratio (1/2 in this example), and is reset by the index signal C to provide positional information with respect to the rotational direction (FIG. 6). A drive signal e as shown in E) is generated. Based on this drive signal e, in this brushless motor drive circuit 17,
, four-phase phase current signals f, g+h, as shown in (I),
1 is created, and by switching the drive current to flow through the four-phase drive coil 6, the drive magnet is rotationally driven.

Further, in the constant speed/constant phase side leg circuit 13, the F
A constant speed/constant phase signal is generated based on the G signal d and the index signal C, and the rotor is controlled to have a constant speed/constant phase based on this signal, as in the case of the previous example.

(Problems to be Solved by the Invention) In the example of the conventional information recording disk drive motor control device configured as described above, the cost is high because the frequency dividing circuit of the servo gate signal generation circuit 21 is expensive. There was a problem with it being up.

In addition, in the case of a Hall brushless motor, the pole element 1
9 and its wiring, which takes up space, making it difficult to downsize, and increasing costs.

The present invention has been made with attention to the above points, and by making the frequency dividing circuit also serve as another function, and by adopting a method in which the pole element is omitted, it is possible to drive a small and low-cost information recording disk. The object of the present invention is to provide a motor control device for use in motor vehicles.

(Means for Solving the Problems) A motor control device for driving an information recording disk of the present invention includes a multipolar drive magnetic pole provided on a rotor directly connected to an information storage disk, and a multipolar drive magnetic pole provided on a stator, which is arranged opposite to this drive magnetic pole. a motor section including a multi-phase drive coil; a rotation speed signal generator disposed in the motor section that generates a rotation speed signal having a frequency corresponding to the rotation speed of the rotor; and 1 representing the rotational position of the rotor. a rotational position signal generator that generates a rotational position signal of one pulse per rotation, and a pulse that divides the rotational speed signal at a predetermined frequency division ratio and is reset by the rotational position signal and becomes positional information with respect to the rotational direction. a motor drive circuit that rotationally drives the rotor by switching and passing a drive current to the multiphase drive coil based on the drive signal; and a servo gate signal generation circuit that generates a servo gate signal that is a pulse corresponding to a servo sector for recording and reproducing a servo signal on the information recording disk based on a signal frequency-divided by a frequency circuit.

(Embodiment) A motor control device for driving an information recording disk according to the present invention employs the above-mentioned seven-type brushless motor and is configured to obtain a servo gate signal using a drive signal of this motor.

FIG. 1 is a block diagram showing an embodiment of the information recording disk drive motor control device of the present invention, and FIG. 2 is a waveform diagram illustrating the operation of the device shown in FIG. This embodiment is an example of a magnetic disk drive motor control device.

As shown in FIG. 1, on concentric recording tracks 2 on the surface of a magnetic disk 1, there are data sectors 4 for recording and reproducing information signals, and servo signals that are signals for controlling the magnetic head for recording and reproducing. Eight servo sectors 3 for recording and reproduction are alternately formed.

This magnetic disk 1 is coaxially and directly connected to the rotor of a drive motor, and is rotationally driven by this rotor.

A motor section is composed of four driving magnetic poles 5 formed on a disc-shaped driving magnet placed on the rotor, and a four-phase driving coil 6 facing the driving a-pole 5 placed on the stator. There is.

A 32i FG magnet lff17 formed in a ring-shaped FG magnet placed on the outer periphery of the drive magnet, and an FG magnetoelectric conversion element for generating a rotational speed signal facing the FG magnetic pole 7 placed on the stator. The head 8 constitutes an FG, and a single PG magnetic pole formed on a PG magnet placed near the outer periphery of the rotor, and a PG head 10 which is a magnetoelectric conversion element for generating a rotational position signal placed on the stator. This constitutes the PG. This FG
The G pole 7 and the PGG pole 9 are aligned with each other in the rotational direction and attached so that the phases of signal waveforms, which will be described later, are aligned with the drive magnetic pole 5.

2 (A
) is generated, and this PG ratio a is supplied to the waveform shaping circuit 11 as shown in FIG. This PG ratio output a is waveform-shaped by this waveform shaping circuit 11 and becomes an index signal C as shown in FIG.
The signal is supplied to the G circuit 16.

On the other hand, the FG head 10 outputs a second signal having a frequency proportional to the rotational speed of 16 cycles per rotation of the rotor.
An FG ratio as shown in FIG. 1B is generated, and this FG ratio is supplied to the waveform shaping circuit 12 as shown in FIG. The waveform shaping circuit 12 outputs the FG ratio by shaping the waveform into a rectangular wave as shown in FIG. , the activation confirmation circuit 14, and the FGG circuit 16.

In the motor, the function similar to that of the Hall element 19 for detecting the driving magnetic pole position of the Hall brushless motor shown in FIG. 3 is performed by the oscillation starting circuit 15 and the FGG circuit 16 shown in FIG.

When the rotor is stopped, the activation confirmation circuit 14 closes the switch SWI and opens the switch SW2, so that the activation signal generated from the oscillation activation circuit 14 is supplied to the brushless motor drive circuit 17. Based on this activation signal, this brushless morph drive cycle f! @17 causes the driving magnet to be rotationally driven by switching the driving current to flow through the four-phase driving coil 6.

Then, based on the FG multiplication signal, the activation confirmation circuit 14
After confirming that the rotor has reached the predetermined rotation speed, open the switch SW1 and switch SW2.
By closing, the output of the FGG circuit 16 is supplied to the brushless motor drive circuit 17. This FG
In the G frequency circuit 16, the frequency of this FG signal is divided by a predetermined frequency division ratio (1/2 in this example) and
A drive signal e as shown in FIG. 2(E), which is reset by the yx signal C and serves as position information in the rotational direction, is generated. Based on this drive signal e, in this brushless motor drive circuit 17, (F), (G), (H
), 4-phase phase current signal f+ g+ as shown in (I)
h+' is created, and by switching the drive current to flow through the four-phase drive coil 6, the drive magnet throat is rotationally driven.

Here, the number of poles Pf of the FG magnetic pole 7 (32 in this example)
is expressed by the following equation, assuming that the number of poles of the driving magnetic pole 5 is P (C is 4 in this example), and the number of phases of the driving coil 6 is Φ (4 in this example).

P f= n X P dXΦ (1) where n is an integer of 1 or more (2 in this example).

Therefore, from equation (1), if the frequency division ratio of the FGG circuit 16 is 1/n, the drive signal e can be obtained from the FG multiplied signal.

Further, in the constant speed/constant phase control circuit 13, the F
A constant speed/constant phase signal is generated based on the G multiplied signal and the index signal C, and the rotor is controlled to have a constant speed/constant phase based on this signal, as in the case of the conventional example described above.

Further, the drive signal e is also supplied to a servo gate signal generation circuit 18 as shown in FIG. This servo game-1
In the signal generating circuit 18, this drive signal e becomes a servo gate signal j as shown in FIG. 2(J), which is a pulse corresponding to the rising edge of the drive signal e. The timing of this servo gate signal j corresponds to the servo sector 3 on the magnetic disk 1, and the falling and rising edges of this pulse j correspond to the start and end points of this servo sector 3, respectively. This servo gate signal j provides the timing for recording and reproducing the servo signal in the servo sector 3 by the recording and reproducing magnetic head, as described above.

Here, the number S of servo sectors 3 per one recording track (8 in this example) is the number Pf of the FG magnetic poles 7.
(32 in this example) is expressed by the following equation.

Pf=2xmxS - (2) Add, m is 1
This is an integer greater than or equal to (2 in this example).

If the number of poles of the FG magnetic pole 7 is selected to be 21 so as to satisfy the above formulas (1) and f2), the signal that is the source of generating the servo gate signal j in the servo gate signal generation circuit 18 will be Since the frequency division signal of the FG frequency division circuit 16 for generating the drive signal e for rotation can be used, costs can be reduced.

Also, since a method is adopted in which the Hall element for detecting the drive magnetic pole position is omitted, it is possible to reduce the size and cost.

Further, the constant speed/constant phase control circuit 13 and the startup confirmation circuit 1
4. The oscillation starting circuit 15, the FG frequency dividing circuit 16, the servo gate signal generation port #r18, etc. can be implemented as a single chip IC, so there is no increase in cost.

Although the above description has been made regarding the case where the drive signal e is generated using the FG multiplied signal, it is also possible to generate the drive signal e using the servo signal. In this case, the number S of servo signals per revolution (equal to the number of servo sectors) may satisfy the following equation according to equation (1) above.

5 = n There is also.

In addition, in a magnetic tisf device using this motor,
Using the servo gate signal j, when the magnetic head for recording and reproducing is located on the data sector 4 and is not in the recording and reproducing state, the power of the circuit for recording and reproducing the information signal can be turned off. Since it can be done, it is possible to reduce power consumption.

Although this embodiment has been described as an example of a motor control device for driving a magnetic disk, the present invention can be applied to a motor control device for driving various information recording disks such as optical disks and magneto-optical disks.

(Effects of the Invention) The information recording disk drive motor control device of the present invention having the above configuration includes an FG for generating a drive signal for rotating the motor in a frequency dividing circuit for generating a servo gate signal.
By using a frequency dividing circuit, costs can be reduced.

Furthermore, since a method is adopted that does not require a Hall element for detecting the drive magnetic pole position, it is possible to reduce the size and cost.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the information recording disk drive mode control device of the present invention, FIG. 2 is a waveform diagram explaining the operation of the device in FIG. 1, and FIG. 3 is a conventional information recording disk drive mode control device. Block diagram illustrating an example of a disk drive motor control device, No. 4
The figure is a waveform diagram explaining the operation of the device shown in FIG. 3, FIG. 5 is a block diagram showing an example of a conventional sensorless type brushless motor control device, and FIG. 6 is a waveform diagram explaining the operation of the device shown in FIG. It is. 1... Magnetic disk, 2... Recording track, 3...
・Servo sector, 4... Data sector, 5... Drive magnetic pole, 6... Drive coil, 7, 7'... FG magnetic pole, 8° 8'... FG head, 9... PG magnetic pole, 10
...PG head, 11,12.12'...Waveform shaping circuit, 13゜13'...Constant speed/constant phase control circuit, 1
4... Start confirmation circuit, 15... Oscillation start circuit, 16
...FG frequency dividing circuit, 17.20...Brushless motor drive circuit, 18.21...Servo gate signal generation circuit, one...Hall element, SWI, SW2...Switch. Patent applicant: Kunio Kakiki, representative of Victor Japan Co., Ltd.

Claims (1)

[Claims] A motor section including multi-polar drive magnetic poles provided on a rotor directly connected to an information recording disk and multi-phase drive coils provided on a stator and arranged opposite to the drive magnetic poles, and the rotor disposed in the motor section. a rotational speed signal generator that generates a rotational speed signal with a frequency corresponding to the rotational speed of the rotor; a rotational position signal generator that generates a rotational position signal of one pulse per rotation representing the rotational position of the rotor; a rotational speed signal frequency dividing circuit that divides the speed signal at a predetermined frequency division ratio, resets it using the rotational position signal, and generates a pulse drive signal serving as positional information with respect to the rotational direction; a motor drive circuit that rotationally drives the rotor by switching and passing a drive current through the drive coil; and a servo sector that records and reproduces a servo signal of the information recording disk based on a signal frequency-divided by the rotational speed signal frequency dividing circuit. 1. A motor control device for driving an information recording disk, comprising: a servo gate signal generation circuit that generates a servo gate signal that is a corresponding pulse.