JP2002101681A - Device and method for controlling spindle motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spindle motor controller capable of preventing excessive turning on/off of servo control and converging to a target revolutions at high speed. SOLUTION: The spindle motor controller for controlling the rotation drive of a spindle motor by a servo mechanism is provided with a detection means (3) for detecting the revolutions of the spindle motor, a detection means (4) for detecting a revolution deviation for the target on the basis of the detected revolution, and control means (5, 6, 7, 12) for controlling the rotation drive of the spindle motor by turning on the servo mechanism when the revolution deviation is stayed in a second range included in a first range in the state that the servo mechanism is turned off/off the servo mechanism when the revolution deviation is out of the first range in the state that the servo mechanism is turned on.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a spindle motor control device and a spindle motor control method for controlling the rotation of a spindle motor applied to an optical disk drive or the like.

[0002]

2. Description of the Related Art In recent years, the use of optical disk drives has been remarkably widespread, and accordingly, demands for rotational drive control of a spindle motor applied to an optical disk drive have been increasing.

It is generally known that the rotation of a spindle motor is controlled by a servo mechanism, that is, an automatic feedback control system. For example, on / off of the servo control by the servo mechanism is switched based on the rotation speed of the spindle motor. Specifically, the switching is performed based on a rotational speed deviation from a target rotational speed of the spindle motor.

[0004]

However, according to the on / off switching of the servo control described above, the switching frequently occurs depending on the on / off switching level of the servo control and the accuracy of the rotation speed detector of the spindle motor. There was a problem that would.

As a simple solution to this problem, a method of setting a wider range of the on / off switching level of the servo control can be considered. In this case, the on / off switching of the servo control can be prevented from frequently occurring, but a new problem arises in that it does not readily converge to the target rotation speed.

An object of the present invention is to provide a spindle motor control device and a spindle motor control method described below in view of the above situation.

(1) A spindle motor control device capable of preventing frequent occurrence of on / off switching of servo control and converging to a target rotational speed at high speed.

(2) A spindle motor control method capable of preventing frequent occurrence of on / off switching of servo control and converging to a target rotation speed at high speed.

[0009]

SUMMARY OF THE INVENTION In order to solve the above problems and achieve the object, a spindle motor control device and a spindle motor control method according to the present invention are configured as follows.

(1) The present invention is a spindle motor control device for controlling the rotation drive of a spindle motor by a servo mechanism, wherein the rotation speed detection means for detecting the rotation speed of the spindle motor and the rotation speed detection means A rotational speed deviation detecting means for detecting a rotational speed deviation from a target rotational speed based on the detected rotational speed; and a second rotational speed deviation included in a first range when the servo mechanism is off. When within the range, the servo mechanism is turned on to control the rotation drive of the spindle motor, and in a state where the servo mechanism is on, the servo mechanism is turned on when the rotation speed deviation deviates from the first range. Control means for turning off and controlling the rotation drive of the spindle motor.

(2) The present invention is a spindle motor control device for controlling the rotation drive of a spindle motor by a servo mechanism, wherein the rotation speed detection means detects the rotation speed of the spindle motor and the rotation speed detection means. A rotational speed deviation detecting means for detecting a rotational speed deviation from a target rotational speed based on the detected rotational speed; and a second range in which the rotational speed deviation is included in a first range when the servo mechanism is off. Until the rotation speed deviation falls, the spindle motor is fully accelerated or decelerated based on the rotation speed deviation, and the rotation drive of the spindle motor is controlled. When the servo mechanism is off, the rotation speed deviation falls within the second range. When the servo mechanism is turned on, the rotational drive of the spindle motor is controlled, and when the servo mechanism is on, the Control means for turning off the servo mechanism when the rotational speed deviation deviates from the first range, and controlling the rotation drive of the spindle motor by fully accelerating or decelerating the spindle motor based on the rotational speed deviation. Have.

(3) The present invention is a spindle motor control method for controlling the rotation drive of a spindle motor by a servo mechanism. When the servo mechanism is off, the rotation speed deviation from the target rotation speed of the spindle motor is reduced. A first step of controlling the rotation drive of the spindle motor by fully accelerating or decelerating the spindle motor based on the rotation speed deviation until the rotation falls within a second range included in the first range; and By the step, when the rotation speed deviation falls within the second range,
A second step of controlling the rotation of the spindle motor by turning on the servo mechanism; and, when the rotation speed deviation is out of the first range, in a state where the servo mechanism is on, the servo mechanism is turned on. Turning off, and performing a full acceleration or a full deceleration of the spindle motor based on the rotational speed deviation to control the rotation drive of the spindle motor.

[0013]

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

FIG. 1 is a block diagram showing an example of a spindle motor control device according to the present invention. This spindle motor control device rotates the optical disc 1 at a predetermined speed by controlling the rotation drive of a spindle motor (SM) 2.

As shown in FIG. 1, the spindle motor control device comprises a spindle motor 2, an FG (frequency generator).
tor) 3, the rotational speed deviation detector 4, the first determiner 5, the second determiner 6, the sequence logic 7, the sign determiner 8, the integrator 9, the adder 10, the filter 11, the first switch 12,
A second switching unit 13 and a drive control unit 14 are provided.

The spindle motor 2 is driven based on a drive control signal output from a drive control unit 14. FG2
Is for detecting the rotation of the spindle motor 2,
A clock pulse signal corresponding to the number of rotations of the spindle motor 2 is output. The rotation speed deviation detection unit 4 compares the clock pulse signal output from the FG 2 with the reference clock pulse signal to detect a rotation speed deviation with respect to the target rotation speed,
It is output as a rotation speed deviation signal.

The first judging section 5 judges whether or not the level of the rotational speed deviation signal output from the rotational deviation detecting section 4 is within a first range. The second determination unit 6 determines whether or not the level of the rotation speed deviation signal output from the rotation deviation detection unit 4 is within a second range included in the first range. That is, the first determination unit 5 determines whether the level of the rotation speed deviation signal falls within a relatively wide range, and the second determination unit 6 determines that the level of the rotation speed deviation signal falls within a relatively narrow range. Is determined.

The sequence logic 7 has, for example, a configuration as shown in FIG. 2, and operates like a truth table shown in FIG. That is, the sequence logic 7
A D circuit 21, an OR circuit 22, and an AND circuit 23 are provided. The output signal (LOCK1) from the first determination unit 5 and the output signal (LOCK2) from the second determination unit 6 are input to the AND circuit 21. The output signal (signal A) from the AND circuit 21 is input to the OR circuit 22. The output signal (OUT) from the OR circuit 22 is an output signal of the sequence logic 7, and the output signal (OUT) is
It is input to the D circuit 23. Further, an output signal (LOCK1) from the first determination unit 5 is also input to the AND circuit 23. The output (signal B) from the AND circuit 23 is O
The signal is input to the R circuit 22.

Thus, when the signal levels of LOCK1 and LOCK2 are both 0, the signal levels of signal A and signal B are also 0, and the signal level of OUT is also 0.
Here, even if only the signal level of LOCK1 changes to 1, the signal levels of the signals A, B, and OUT still remain at 0. Further, when the signal level of LOCK2 changes to 1, that is, LOCK1 and LOCK2
When the signal levels of the signals A and B both change to 1, the signal levels of the signals A and B change to 1 and the signal level of OUT also changes to 1. Thereafter, when only the signal level of LOCK2 changes to 0, that is, the signal level of LOCK1 remains 1,
When only the signal level of LOCK2 changes to 0, the signal level of signal A changes to 0, but the signal level of signal B remains at 1, and the signal level of OUT also remains at 1. After that, when the signal level of LOCK1 also changes to 0,
That is, the signal levels of LOCK1 and LOCK2 are both 0.
, The signal levels of the signals A, B, and OUT all change to 0.

The sign judging unit 8 judges the sign of the rotation speed deviation signal output from the rotation speed deviation detection unit 4. By determining the sign of the rotational speed deviation signal, it is possible to determine whether the current rotational speed is lower or higher than the target rotational speed.
That is, it is possible to determine whether the current rotation speed is lower or higher than the target rotation speed. The integrator 9 integrates the rotation speed deviation signal output from the rotation speed deviation detection unit 4. The adder 10 multiplies both the rotation speed deviation signal and the integration signal of the rotation speed deviation (phase deviation signal) by an appropriate coefficient and adds them. The filter 11 performs an appropriate filtering process on the addition signal output from the adder 10.

The second switching unit 13 switches between full acceleration control and full deceleration control based on the sign judgment result output from the sign judgment unit 8. That is, when the current rotation speed is lower than the target rotation speed, the full acceleration control is selected, and when the current rotation speed is higher than the target rotation speed, the full deceleration control is selected. The first switching unit 12 inputs the addition signal output from the filter 11 to the drive control unit 14 or inputs an instruction of full acceleration control or full deceleration control based on the output signal from the sequence logic.

The drive control unit 14 controls the rotational drive of the spindle motor. When the addition signal output from the filter 11 is input to the drive control unit 14 by the switching of the first switching unit 12, the drive control unit 14 controls the rotation drive of the spindle motor 2 based on the addition signal. That is, in this state, the drive control unit 14 functions as a component of the servo mechanism and executes the servo control. When an instruction for full acceleration control or full deceleration control is input to the drive control unit 14 by switching of the first switching unit 12, the drive control unit 14 determines whether the spindle Full-acceleration or full-deceleration control is performed on the rotation of the motor.

That is, the switching of the first switching section 12 switches on / off of the servo mechanism. The state in which the addition signal output from the filter 11 is input to the drive control unit 14 by the switching of the first switching unit 12 is a state in which the servo mechanism is on, and the instruction of the full acceleration control or the full deceleration control is the drive control. The state input to the unit 14 is a state where the servo mechanism is off.

Next, a method of controlling a spindle motor according to the present invention will be described with reference to FIG. FIG. 4 is a flowchart showing a spindle motor control method according to the present invention.

When the start of the spindle motor 2 is requested from the state where the spindle motor 2 is stopped (the state where the servo mechanism is off) (S1 → S2), the rotational speed deviation becomes the second.
The spindle motor 2 is fully accelerated until it falls within the range (S2). In other words, when the motor is stopped,
The level of the rotational speed deviation signal output from the rotational speed deviation detection unit 4 is out of the first range (a large deviation from the target rotational speed). At this time, the first determination unit 5 outputs level 0, and the second determination unit 6 also outputs level 0. Accordingly, the sequence logic 7 outputs level 0 (see the truth table shown in FIG. 3). When the level 0 is output from the sequence logic 7, the first switching unit 12 switches so that an instruction for full acceleration or full deceleration is input to the drive control unit 14. That is, the servo mechanism remains off. On the other hand, the sign determination unit 8 determines from the determined sign that the current rotational speed is lower than the target rotational speed.
Accordingly, the second switching unit 13 selects the full acceleration.
That is, an instruction for full acceleration is input to the drive control unit 14, and the drive control unit 14 controls the spindle motor 2 for full acceleration.

With the above-described full acceleration control, the level of the rotational speed deviation signal eventually falls within the first range. However, it is assumed that it is still outside the second range. At this time, the first determination unit 5 outputs level 1 and the second determination unit 6 outputs level 0. Accordingly, the sequence logic 7 is at level 0
(See the truth table shown in FIG. 3). When the level 0 is output from the sequence logic 7, the first switching unit 12 switches so that an instruction for full acceleration or full deceleration is input to the drive control unit 14. That is, the servo mechanism remains off. At this time, for example, if the sign determination unit 8 determines that the current rotation speed is lower than the target rotation speed, the second switching unit 13 selects full acceleration. That is, the instruction of the full acceleration is continuously input to the drive control unit 14, and the drive control unit 14
Accordingly, full acceleration control of the spindle motor 2 is continued.

Further, if the above-described full acceleration control is continued, the level of the rotational speed deviation signal falls within the second range (S
2 → S3). That is, the rotation speed of the spindle motor approaches the target rotation speed. At this time, the first determination unit 5 outputs level 1, and the second determination unit 6 also outputs level 1. Accordingly, the sequence logic 7 outputs the level 1 (see the truth table shown in FIG. 3). When the level 1 is output from the sequence logic 7, the first switching unit 12 switches so that the addition signal output from the filter 11 is input to the drive control unit 14. That is, the servo mechanism is turned on, and the drive control unit 14 controls the rotation drive of the spindle motor 2 based on the addition signal output from the filter 11 (servo control starts).

Thereafter, the level of the rotational speed deviation signal is changed to the second level.
Even if it falls outside the range, if it falls within the first range,
The servo mechanism keeps on (servo control continues). That is, once the rotation speed of the spindle motor approaches the target rotation speed (after falling within the second range), even if it slightly deviates from this target rotation speed (if it falls within the first range), The servo mechanism keeps on. That is, even if the first determination unit 5 outputs the level 1 and the second determination unit 6 also outputs the level 1, the first determination unit 5 outputs the level 1 and the second determination unit 6 outputs the level 0. , The sequence logic 7 keeps outputting the level 1 (see the truth table shown in FIG. 3). That is, the servo mechanism is kept turned on.

Thereafter, when the level of the rotational speed deviation signal is out of the first range (S3 → S2 or S3 → S
5) The servo mechanism is turned off, and full acceleration (S2) or full deceleration (S5) is performed. That is, the first determination unit 5 outputs level 0, and the second determination unit 6 also outputs level 0. Accordingly, the sequence logic 7 outputs level 0 (see the truth table shown in FIG. 3). When the level 0 is output from the sequence logic 7, the first switching unit 12 switches so that an instruction for full acceleration or full deceleration is input to the drive control unit 14. That is, the servo mechanism is turned off. On the other hand, when the sign determining unit 8 determines that the current rotational speed is lower than the target rotational speed based on the determined code, the second switching unit 13 selects full acceleration accordingly. Conversely, when it is determined that the current rotational speed is higher than the target rotational speed, the second switching unit 13 selects full deceleration accordingly. That is, an instruction for full acceleration or full deceleration is input to the drive control unit 14, and the drive control unit 14 performs full acceleration or full deceleration control of the spindle motor 2. When both the first determination unit 5 and the second determination unit 6 output level 0, the sequence logic 7 outputs a reset signal to the integrator 9.

As described above, according to the spindle motor control device and the spindle motor control method of the present invention, the servo control is started when the current rotational speed sufficiently approaches the target rotational speed. After approaching the rotation speed, the servo control is continued even if the rotation speed slightly deviates from the target rotation speed, and the servo control is terminated only when the rotation speed largely deviates from the target rotation speed. This makes it possible to achieve both convergence with respect to the target rotational speed and stability of servo control.

It should be noted that the present invention is not limited to the above-described embodiment, and that various modifications can be made in the implementation stage without departing from the scope of the invention. In addition, the embodiments may be implemented in appropriate combinations as much as possible, in which case the combined effects can be obtained. Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriate combinations of a plurality of disclosed constituent elements. For example, even if some components are deleted from all the components shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effects described in the column of the effect of the invention can be solved. If you get
A configuration from which this configuration requirement is deleted can be extracted as an invention.

[0032]

According to the present invention, the following spindle motor control device and spindle motor control method can be provided.

(1) A spindle motor control device capable of preventing frequent on / off switching of servo control and converging to a target rotational speed at high speed.

(2) A spindle motor control method capable of preventing frequent occurrence of on / off switching of servo control and converging to a target rotation speed at high speed.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of a spindle motor control device according to the present invention.

FIG. 2 is a diagram illustrating a configuration example of a sequence logic illustrated in FIG. 1;

FIG. 3 is a diagram showing an operation of the sequence logic shown in FIG. 2;

FIG. 4 is a flowchart illustrating an example of a spindle motor control method according to the present invention.

[Explanation of symbols]

 2 ... Spindle motor 3 ... FG 4 ... Rotation speed deviation detection unit 5 ... First judgment unit 6 ... Second judgment unit 7 ... Sequence logic 8 ... Sign judgment unit 9 ... Integrator 10 ... Adder 11 ... Filter 12 ... First Switching unit 13: Second switching unit 14: Drive control unit

Claims (3)

[Claims] 1. A spindle motor control device for controlling the rotation drive of a spindle motor by a servo mechanism, comprising: a rotation speed detection means for detecting a rotation speed of the spindle motor; and a rotation speed detected by the rotation speed detection means. Based on
A rotational speed deviation detecting means for detecting a rotational speed deviation with respect to a target rotational speed; and the servo mechanism when the rotational speed deviation falls within a second range included in a first range when the servo mechanism is off. Is turned on to control the rotation drive of the spindle motor, and in a state where the servo mechanism is on, when the rotation speed deviation deviates from the first range, the servo mechanism is turned off to rotate the spindle motor. A spindle motor control device, comprising: control means for controlling driving. 2. A spindle motor control device for controlling a rotation drive of a spindle motor by a servo mechanism, comprising: a rotation number detecting means for detecting a rotation number of the spindle motor; and a rotation number detected by the rotation number detecting means. Based on
Rotation speed deviation detection means for detecting a rotation speed deviation with respect to a target rotation speed; and when the servo mechanism is off, the rotation speed deviation until the rotation speed deviation falls within a second range included in the first range. Control the rotation drive of the spindle motor by full acceleration or full deceleration of the spindle motor based on
In the state where the servo mechanism is off, when the rotation speed deviation falls within the second range, the servo mechanism is turned on to control the rotation drive of the spindle motor, and in the state where the servo mechanism is on, the Control means for turning off the servo mechanism when the rotational speed deviation deviates from the first range, and controlling the rotational drive of the spindle motor by fully accelerating or decelerating the spindle motor based on the rotational speed deviation; A spindle motor control device comprising: 3. A spindle motor control method for controlling a rotation drive of a spindle motor by a servo mechanism, wherein a deviation of a rotation number of the spindle motor from a target rotation number is in a first range when the servo mechanism is off. A first step in which the spindle motor is fully accelerated or decelerated based on the rotational speed deviation to control the rotation drive of the spindle motor until the rotation falls within a second range included in the first step; Number deviation is the second
A second step of turning on the servo mechanism to control the rotation drive of the spindle motor when the servo mechanism is turned on; and the rotation speed deviation deviating from the first range when the servo mechanism is on. A third step of controlling the rotation of the spindle motor by fully accelerating or decelerating the spindle motor based on the rotational speed deviation when the servo mechanism is turned off. Motor control method.