JPH06103996B2 - Motor controller for driving information recording disk - Google Patents

Description

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 of recording / reproducing a servo signal, which is a signal for controlling the recording / reproducing magnetic head, is recorded in a servo sector provided between data sectors on concentric recording tracks of the magnetic disk. A servo gate signal is required to obtain the servo gate signal, and this servo gate signal may be obtained from the magnetic disk drive motor.

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

As shown in FIG. 3, a data sector 4 for recording / reproducing an information signal and a servo signal which is a signal for controlling a magnetic head for recording / reproducing are provided on a concentric recording track 2 on the surface of a magnetic disk 1. 8 recording and reproducing servo sectors 3 are alternately formed.

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

A four-pole driving magnetic pole 5 formed on a disk-shaped driving magnet arranged on the rotor, a four-phase driving coil 6 facing the driving magnetic pole 5 arranged on the stator, and position detection of the driving magnetic pole 5. The motor is composed of two Hall elements 19 arranged at an electrical angle of 90 ° for use.

Then, based on the drive magnetic pole position detection signal of the Hall element 19, the brushless motor drive circuit 20 switches the drive current to the four-phase drive coil 6 to flow it,
This drive magnet is driven to rotate.

Further, this motor is provided with a frequency generator (hereinafter abbreviated as FG) for detecting the rotation speed and a pulse generator (hereinafter abbreviated as PG) for the rotation phase detection.

That is, a 16-pole FG magnetic pole 7'formed on a ring-shaped FG magnet arranged on the outer periphery of the driving magnet, and a magnetoelectric conversion element for generating a rotation speed signal facing the FG magnetic pole 7'arranged on the stator. This FG with the FG head 8 '
And a PG magnetic pole 9 of a single pole formed on a PG magnet arranged near the outer periphery of the rotor, and a PG head 10 which is a magnetoelectric conversion element for generating a rotational position signal arranged on the stator. It constitutes the PG.

And with the rotation of the rotor, the PG head 10
Once per revolution of this rotor, this PG magnetic pole 9
A PG output a as shown in FIG. 4A is generated for each rotation angle facing the head 10, and the PG output a is supplied to the waveform shaping circuit 11 as shown in FIG. The waveform shaping circuit 11 waveform-shapes the PG output a into an index signal c as shown in FIG. 4 (C), which is supplied to the constant speed / constant phase control circuit 13 'as shown in FIG. .

On the other hand, from the FG head 8 ', an FG output b'as shown in FIG. 4 (B) having a frequency proportional to the rotation speed of 8 cycles per rotation of the rotor is generated, and this FG output b'is generated. It is supplied to the waveform shaping circuit 12 'as shown in FIG. The FG output b'is shaped by the waveform shaping circuit 12 'into a rectangular wave as shown in FIG.
The constant speed / constant phase control circuit shown in FIG.
Supplied to 13 '. In the constant speed / constant phase control circuit 13 ', a constant speed / constant phase control signal which is a signal for controlling the rotor to the constant speed / constant phase is generated based on the FG signal d'and the index signal c. It is supplied to the brushless motor drive circuit 20. In the brushless motor drive circuit 20, by adjusting the drive current flowing through the drive coil 6 based on the constant speed / constant phase control signal, a loop for negatively feeding back the speed and phase is formed in the motor as described above. Therefore, the rotor is controlled to have a constant speed and a constant phase.

Further, the index signal c and the FG signal d ′ are also supplied to the servo gate signal generation circuit 21. The FG signal d'is reset by the index signal c in the servo gate signal generation circuit 21 and is a pulse corresponding to the rising edge of the servo gate as position information with respect to the rotational direction, as shown in FIG. 4 (E). It becomes the signal j. The timing of the servo gate signal j corresponds to the servo sector 3 on the magnetic disk 1, and the falling and rising edges of the pulse j correspond to the start point and the end point of the servo sector 3, respectively. This servo gate signal j provides the timing for recording / reproducing the servo signal by the recording / reproducing magnetic head in the servo sector 3 as described above.

In the above description of the conventional example, for the sake of simplification of description, the case where the number of servo sectors is 8 per recording track has been described, but in reality, 17 or 34 servo sectors are used. The same applies to the description of other examples described later.

Also, the FG has been described as an example in which the number of pulses of the FG output is the same as the number of servo sectors of 8 cycles per rotation, but the controllability of the constant speed control of the motor is such that the greater the number of pulses of this FG output, Since it is good, the number of pulses per rotation of the FG output may be selected to be twice or more the number of servo sectors. In this case, the FG output is frequency-divided by the 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.

The motor described above is an example of a so-called hall brushless motor in which a 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, but as shown in FIG. A so-called sensorless type brushless motor in which a Hall element for detecting a magnetic pole position is omitted is known.

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 for explaining the operation of the device of FIG.

As shown in FIG. 5, a four-pole driving magnetic pole 5 formed on a disk-shaped driving magnet arranged on the rotor, and a four-phase driving coil 6 facing the driving magnetic pole 5 arranged on the stator. It constitutes the motor unit.

In addition, a ring-shaped member arranged on the outer periphery of the drive magnet.
An FG is constituted by 32 FG magnetic poles 7 formed in the FG magnet and an FG head 8 which is a magnetoelectric conversion element for generating a rotation speed signal facing the FG magnetic pole 7 arranged in the stator,
A PG magnetic pole 9 of a single pole formed on a PG magnet arranged near the outer circumference of the rotor, and a PG head 10 which is a magnetoelectric conversion element for generating a rotational position signal arranged on the stator,
Are configured.

With the rotation of the rotor, the PG head 10 rotates once per rotation of the rotor, as shown in FIG. 6 (A), for each rotation angle at which the PG magnetic pole 9 faces the PG head 10. PG output a is generated, and this PG output a is supplied to the waveform shaping circuit 11 as shown in FIG. This waveform shaping circuit
At 11, the PG output a is waveform-shaped and becomes an index signal c as shown in FIG. 6 (C). This index signal c is supplied to the constant speed / constant phase control circuit 13 as shown in FIG.
It is supplied to the FG divider circuit 16.

On the other hand, from the FG head 8, an FG output b having a frequency proportional to the rotation speed of 16 cycles per rotation of the rotor as shown in FIG. 6 (B) is generated, and this FG output b is shown in FIG. It is supplied to the waveform shaping circuit 12 as shown in FIG. The FG output b is shaped by the waveform shaping circuit 12 into a rectangular wave as shown in FIG. 6 (D) and becomes an FG signal d. This FG signal d has a constant velocity / constant phase as shown in FIG. It is supplied to the control circuit 13, the startup confirmation circuit 14, and the FG frequency divider circuit 16.

In this motor, the function of the Hall element 19 for detecting the drive magnetic pole position of the Hall brushless motor shown in FIG.
This is performed by the oscillation starting circuit 15 and the FG frequency dividing circuit 16 shown in the figure.

When the rotor is stopped, the switch SW1 is closed and the switch SW2 is opened by the action of the start confirmation circuit 14,
The start signal generated from the oscillation start circuit 15 is supplied to the brushless motor drive circuit 17. On the basis of this start signal, the brushless motor drive circuit 17 switches the drive current to the four-phase drive coil 6 to flow,
The drive magnet is driven to rotate.

Then, based on the FG signal d, it is confirmed that the rotor has reached a predetermined number of revolutions by the action of the start confirmation circuit 14, and the switch SW1 is opened and the switch SW2 is closed, whereby the FG frequency divider circuit The output of 16 is supplied to the brushless motor drive circuit 17. In the FG frequency dividing circuit 16, the FG signal d is frequency-divided at a predetermined frequency division ratio (1/2 in this example), and is reset by the index signal c to become position information in the rotation direction. Figure (E)
The drive signal e as shown in is generated. This drive signal e
Based on this, in the brushless motor drive circuit 17, four-phase phase current signals f, g, h, i as shown in FIGS. 6 (F), (G), (H), and (I) are generated. Thus, the drive magnet is rotationally driven by switching and supplying a drive current to the four-phase drive coil 6.

Further, in the constant speed / constant phase control circuit 13, a constant speed / constant phase signal is generated based on the FG signal d and the index signal c.・ Controlled to a constant phase.

(Problems to be Solved by the Invention) In the example of the conventional motor controller for driving an information recording disk having the above-mentioned configuration, the frequency is increased in the frequency dividing circuit of the servo gate signal generation circuit 21, which leads to an increase in cost. There was a problem.

In the case of a hall brushless motor, the hall element 19
Also, due to the wiring, it is difficult to reduce the size and size, and the cost is high.

The present invention has been made by paying attention to the above points, and the frequency dividing circuit also serves as another function, and by adopting a method in which the Hall element is omitted, a compact and low cost information recording disk drive It is an object of the present invention to provide a motor control device for a vehicle.

(Means for Solving the Problems) The motor controller for driving the information recording disk of the present invention is arranged so as to face the multi-pole driving magnetic pole provided in the rotor directly connected to the information recording disk and the driving magnetic pole provided in the stator. A motor unit including a multi-phase drive coil, a rotation speed signal generator for generating a rotation speed signal having a frequency according to the rotation speed of the rotor, which is arranged in the motor unit, and a rotation position of the rotor. A rotation position signal generator for generating a rotation position signal of one pulse per rotation, and a pulse for dividing the rotation speed signal by a predetermined frequency division ratio and resetting by the rotation position signal to be position information in the rotation direction. And a rotational speed signal frequency dividing circuit for generating a drive signal for the rotor and rotating the rotor by switching and supplying a drive current to the multi-phase drive coils based on the drive signal. A moving motor drive circuit and a servo gate signal generation circuit for generating a servo gate signal which is a pulse corresponding to a servo sector for recording / reproducing a servo signal of the information recording disk based on the signal divided by the rotation speed signal dividing circuit. And is configured to include.

(Embodiment) The motor controller for driving an information recording disk of the present invention employs the above-mentioned sensorless brushless motor and is configured to obtain a servo gate signal by using the drive signal of this motor.

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

As shown in FIG. 1, on a concentric recording track 2 on the surface of a magnetic disk 1, a data sector 4 for recording / reproducing an information signal and a servo signal which is a signal for controlling a recording / reproducing magnetic head. 8 recording and reproducing servo sectors 3 are alternately formed.

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

A four-pole drive magnetic pole 5 formed on a disk-shaped drive magnet disposed on the rotor and a four-phase drive coil 6 facing the drive magnetic pole 5 disposed on the stator constitute a motor unit.

In addition, a ring-shaped member arranged on the outer periphery of the drive magnet.
The FG magnetic pole 7 has 32 poles formed on the FG magnet, and the FG head 8 and the FG which are magnetic-electric conversion elements for generating a rotation speed signal facing the FG magnetic pole 7 arranged on the stator are constituted.
A single-pole PG magnetic pole 9 formed on a PG magnet arranged near the outer circumference of the rotor and a PG head 10 which is a magnetoelectric conversion element for generating a rotational position signal arranged on the stator constitute a PG. The FG magnetic pole 7 and the PG magnetic pole 9 are attached to the drive magnetic pole 5 so as to be aligned with each other in the rotational direction so that the phases of signal waveforms described later are aligned with each other.

And with the rotation of the rotor, the PG head 10
Once per revolution of this rotor, this PG magnetic pole 9
A PG output a as shown in FIG. 2 (A) is generated for each rotation angle facing the head 10, and this PG output a is supplied to the waveform shaping circuit 11 as shown in FIG. This waveform shaping circuit 11
Then, this PG output a is subjected to waveform shaping to become an index signal c as shown in FIG. 2 (C), which is supplied to the constant speed / constant phase control circuit 13 and the FG frequency dividing circuit 16 as shown in FIG. It

On the other hand, the FG head 10 produces an FG output b having a frequency proportional to the rotational speed of 16 cycles per revolution of the rotor as shown in FIG. 2 (B). It is supplied to the waveform shaping circuit 12 as shown in FIG. In the waveform shaping circuit 12, the FG output b is shaped into a rectangular wave as shown in FIG. 2 (D) and becomes an FG signal d, and the constant speed / constant phase control circuit 13, as shown in FIG. It is supplied to the startup confirmation circuit 14 and the FG frequency divider circuit 16.

In this motor, the function like the hall element 19 for detecting the drive magnetic pole position of the hall brushless motor shown in FIG.
This is performed by the oscillation starting circuit 15 and the FG frequency dividing circuit 16 shown in the figure.

When the rotor is stopped, the switch SW1 is closed and the switch SW2 is opened by the action of the start confirmation circuit 14,
A start signal generated from the oscillation start circuit 14 is supplied to the brushless motor drive circuit 17. On the basis of this start signal, the brushless motor drive circuit 17 switches the drive current to the four-phase drive coil 6 to flow,
The drive magnet is driven to rotate.

Then, based on the FG signal d, it is confirmed that the rotor has reached a predetermined number of revolutions by the action of the start confirmation circuit 14, and the switch SW1 is opened and the switch SW2 is closed, whereby the FG frequency divider circuit 16 Is supplied to the brushless motor drive circuit 17. In this FG divider circuit 16,
The FG signal d is divided by a predetermined division ratio (1/2 in this example) and is reset by the index signal c to become position information in the rotation direction as shown in FIG. 2 (E). The drive signal e is generated. Based on this drive signal e, in the brushless motor drive circuit 17, four-phase phase current signals f, g, h, i as shown in FIGS. 2 (F), (G), (H) and (I) are generated. The drive magnet is made to rotate and the drive magnet is rotated by switching the drive current to the four-phase drive coil 6.

Here, the FG (in this example 32) the number of poles P _f of the magnetic poles 7 of the number of poles of said driving magnetic pole 5 P _d (4 in this example), in the number of phases of the [Phi (this example of the drive coil 6 4) is expressed by the following equation.

P _f = N × _d × Φ (1) However, n is an integer of 1 or more (2 in this example).

Therefore, from equation (1), divide the division ratio of the FG divider circuit 16 to 1 / n
Then, the drive signal e is obtained from the FG signal d.

Further, in the constant speed / constant phase control circuit 13, a constant speed / constant phase signal is generated based on the FG signal d and the index signal c, and the rotor is controlled based on this signal as in the case of the above-mentioned conventional example. Controlled by speed and constant phase.

The drive signal e is also supplied to the servo gate signal generation circuit 18 as shown in FIG. In the servo gate signal generation circuit 18, the drive signal e becomes a servo gate signal j as shown in FIG. 2 (J) which is a pulse corresponding to its rising edge. This servo gate signal j
Timing corresponds to the servo sector 3 on the magnetic disk 1, and the falling edge and the rising edge of the pulse j correspond to the start point and the end point of the servo sector 3, respectively.
As a result, the timing at which the servo signal is recorded / reproduced by the recording / reproducing magnetic head can be obtained as described above.

Here, the number S of the servo sectors 3 per recording track (8 in this example) and the number of poles P _f of the FG magnetic pole 7 (32 in this example) are expressed by the following equation.

P _f = 2 × m × S (2) However, m is an integer of 1 or more (2 in this example).

If the number of poles P _f of the FG magnetic pole 7 is selected so as to satisfy the above equations (1) and (2), the signal from which the servo gate signal generating circuit 18 generates the servo gate signal j is Since the frequency dividing signal of the FG frequency dividing circuit 16 for generating the drive signal e for rotating the rotor can be used, the cost can be reduced.

Further, since the method in which the Hall element for detecting the drive magnetic pole position is omitted is adopted, downsizing and cost reduction can be realized.

Further, the constant speed / constant phase control circuit 13, the start confirmation circuit 14,
The oscillation starting circuit 15, the FG frequency dividing circuit 16, the servo gate signal generating circuit 18, and the like can be integrated into a single chip IC, so that the cost does not increase.

In the above description, the case where the drive signal e is generated by using the FG signal d has been described, but it is also possible to generate the drive signal e by using the servo signal.
In this case, the number of servo signals per rotation (equal to the number of servo sectors) S may satisfy the following equation according to the equation (1).

S = n × P _d × Φ / 2 (3) Further, the constant speed control by the constant speed / constant phase control circuit 13 is a constant speed in one recording track, and is constant in other recording tracks. The speed may change.

Also, in a magnetic disk device using this motor,
By using the servo gate signal j, when the recording / reproducing magnetic head is on the data sector 4 and is not in the recording / reproducing state, the power of the information signal recording / reproducing circuit can be turned off. As a result, low power consumption can be achieved.

In the present embodiment, an example of a motor control device for driving a magnetic disk has been described, but 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.

(Effect of the Invention) In the information recording disk drive motor control device of the present invention having the above-described configuration, the frequency dividing circuit for generating the servo gate signal is provided with the FG frequency dividing circuit for generating the drive signal for rotating the motor. Since it is used, the cost can be reduced.

Further, since the method in which the Hall element for detecting the drive magnetic pole position is omitted is adopted, the size and cost can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a motor control device for driving an information recording disk of the present invention, FIG. 2 is a waveform diagram for explaining the operation of the device of FIG. 1, and FIG. 3 is a conventional information recording disk. 4 is a block diagram showing an example of a drive motor control device, FIG.
FIG. 5 is a waveform diagram for explaining the operation of the device of FIG. 3, FIG. 5 is a block diagram showing an example of a conventional sensorless brushless motor control device, and FIG. 6 is a waveform diagram for explaining the operation of the device of FIG. 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 ′ …… Wave shaping circuit, 13,13 ′ …… Constant speed / constant phase control circuit, 14
...... Startup confirmation circuit, 15 …… Oscillation start circuit, 16 …… FG divider circuit, 17,20 …… Brushless motor drive circuit, 18,21 …… Servo gate signal generation circuit, 19 …… Hall element, SW1, SW2 …… Switch.

Claims (1)

[Claims] 1. A motor unit comprising a multi-pole drive magnetic pole provided on a rotor directly connected to an information recording disk and a multi-phase drive coil disposed on the stator so as to face the drive magnetic pole.
A rotation speed signal generator for generating a rotation speed signal having a frequency corresponding to the rotation speed of the rotor, which is arranged in the motor unit, and a rotation position signal of one pulse per one rotation indicating the rotation position of the rotor. Rotating position signal generator,
A rotation speed signal frequency dividing circuit that divides the rotation speed signal by a predetermined frequency division ratio and resets the rotation speed signal by the rotation position signal to generate a drive signal of a pulse that becomes position information with respect to a rotation direction, and based on the drive signal, A servo signal of the information recording disk is recorded / reproduced on the basis of a signal divided by a motor drive circuit for rotationally driving the rotor by switching and supplying a drive current to a multi-phase drive coil and the rotation speed signal frequency dividing circuit. An information recording disk drive motor control device comprising: a servo gate signal generation circuit that generates a servo gate signal that is a pulse corresponding to a servo sector.