JPH09251708A - Device and method for controlling rotation of disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to use a circuit used only for a CAV(constant angular velocity) control mode also for a CLV(constant linear velocity) control and to rapidly lead in a high revolution speed in a rotation controller for a disk capable of selectively performing an operation in the CAV control mode or the CLV control mode for an optical disk. SOLUTION: A CAV rotation error detection circuit 8 detecting an error of the actual number of revolution from the reference number of revolution of a spindle motor 22 rotating the optical disk 21 and a CAV control voltage output circuit 9 converting the error to a control voltage which are used for execution of the CAV control mode are used even in the execution of the CLV control mode. The voltage from an MPU 7 equivalent to a rotation error signal as a reference from the target number of revolution of a track is compared with the control voltage from the CAV control voltage output circuit 9 by a comparator 11, and the control voltage is outputted from the comparator 11 to an adder 10 so as to allow a maximum current to flow through the spindle motor 22 until its difference becomes within a prescribed threshold value.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a CAV (Constant Angular Velocit) for rotating a disc at a constant angular velocity.
y) CLV that rotates the mode and the disc at a constant linear velocity
The present invention relates to a rotation control device for a disc and a rotation control method for the disc that are compatible with both (Constant Linear Velocity) mode.

[0002]

2. Description of the Related Art An optical disk as a recording medium on which information such as a video signal and an audio signal is recorded is a disk such as an MO (CAV disk) whose rotation speed is constant, and a disk whose constant linear velocity is constant. CD- whose rotational speed varies depending on the direction
There is a disk such as a ROM (CLV disk). In the optical disk device which is capable of reproducing any of these types of optical disks, that is, in an optical disk device having two modes of CAV mode and CLV mode, two rotation control systems, that is, a CAV rotation control system and a CLV rotation control system are provided. I have it.

A conventional rotation control device having these two rotation control systems will be described. FIG. 3 is a block diagram showing the configuration example. In FIG. 3, reference numeral 21 is an optical disk to be reproduced, and the optical disk 21 is a spindle motor 22.
Is rotated by. Below the optical disc 21, an optical head 1 for irradiating a converged spot of a laser beam onto the optical disc 21 and obtaining a reproduction signal from the reflected light is provided in an actuator 23. The actuator 23 is M
The optical head 1 is moved to the optical disk 21 under the control of the PU 7.
To move in the radial direction.

The optical head 1 uses the read reproduction signal as a PL
Output to the L circuit 2. The PLL circuit 2 extracts a data pattern synchronization signal from the read data reproduction signal on the optical disc 21 and outputs it to the CLV rotation error detection circuit 3. The CLV rotation error detection circuit 3 obtains an error signal between this synchronization signal and a predetermined CLV reference signal and outputs it to the CLV control voltage output circuit 4. The CLV control voltage output circuit 4 converts this error signal into a control voltage and outputs it to the spindle motor drive circuit 5 via the control voltage selection circuit 6. The spindle motor drive circuit 5 drives the spindle motor 22 according to this control voltage to control the rotation speed of the optical disk 21. The optical head 1, the PLL circuit 2, the CLV rotation error detection circuit 3, the CLV control voltage output circuit 4, the spindle motor drive circuit 5, and the control voltage selection circuit 6 CL
It constitutes a V rotation control system.

The spindle motor drive circuit 5 outputs a rotation signal indicating the rotation speed of the spindle motor 22 to the CAV rotation error detection circuit 8. The CAV rotation error detection circuit 8 obtains an error signal between this rotation signal and the CAV reference signal, and CA
Output to the V control voltage output circuit 9. The CAV control voltage output circuit 9 converts this error signal into a control voltage and outputs it to the spindle motor drive circuit 5 via the control voltage selection circuit 6. The spindle motor drive circuit 5 drives the spindle motor 22 according to this control voltage to control the rotation speed of the optical disk 21. The spindle motor drive circuit 5, control voltage selection circuit 6, CAV rotation error detection circuit 8 and CAV control voltage output circuit 9 constitute a CAV rotation control system.

Next, the operation will be described. When the MPU 7 issues a command to move the optical head 1, the actuator 23 moves the optical head 1 to the target track. The PLL circuit 2 extracts a data pattern synchronization signal from the data reproduction signal on the optical disc 21 output from the optical head 1. After the error signal is obtained by the CLV rotation error detection circuit 3 from the synchronization signal and the rotation reference signal, it is converted into a control voltage by the CLV control voltage output circuit 4, and the spindle motor is driven via the control voltage selection circuit 6. It is input to the circuit 5. At this time, the MPU 7 is connected to C of the control voltage selection circuit 6.
The LV control side is selected. In this way, the optical head 1
The loop of the PLL circuit 2, the CLV rotation error detection circuit 3, the CLV control voltage output circuit 4, the control voltage selection circuit 6, and the spindle motor drive circuit 5 shows the flow of the CLV rotation control system.

After the CAV rotation error detection circuit 8 obtains an error signal from the spindle rotation signal and the reference signal output from the spindle motor drive circuit 5, the CAV control voltage output circuit 9 converts the error signal into a control voltage. It is input to the spindle motor drive circuit 5 via the control voltage selection circuit 6. At this time, the MPU 7 selects the CAV control side of the control voltage selection circuit 6. In this way, the loop of the spindle motor drive circuit 5-> CAV rotation error detection circuit 8-> CAV control voltage output circuit 9-> control voltage selection circuit 6-> spindle motor drive circuit 5 shows the flow of the CAV rotation control system.

[0008]

In the conventional rotation control device capable of coping with the two rotation modes as described above, the CL
The V rotation control system and the CAV rotation control system are independent, and while one rotation control system is operating, the other rotation control system is completely unused and there is a problem that efficiency is poor. Further, in the case of a CLV disk, since the rotation speed differs depending on the radial position, when the optical head 1 is moved, it is necessary to quickly pull in to the rotation speed that matches the radial position, but control using only the CLV rotation error signal. However, there is a problem that it takes a long time to pull in the rotation speed.

The present invention has been made in view of the above circumstances, and the CAV rotation error detection circuit, which has been unused in the past, can be used during the operation of the CLV rotation control, and moreover, compared with the conventional example. An object of the present invention is to provide a disk rotation control device and a rotation control method thereof, which can quickly pull in the rotation speed.

[0010]

According to a first aspect of the present invention, there is provided a disk rotation control device which selectively performs CAV rotation control or CLV rotation control on a disk and which is used when the CAV rotation control is executed. In a disk rotation control device having an error detection circuit for detecting an error between the disk rotation speed and a predetermined rotation speed, the error detection circuit is used even when the CLV rotation control is executed. Is characterized by.

A rotation control method for a disk rotation control device according to a second aspect of the present invention is a rotation control method for a disk rotation control device for selectively performing CAV rotation control or CLV rotation control on a disk. In doing so, the difference between the actual number of revolutions of the disc and the predetermined number of revolutions is calculated, and while the absolute value of the difference is greater than the predetermined value, the disc is rotated to increase or decrease the predetermined number of revolutions. It is characterized by controlling rotation.

In the present invention, the CAV rotation error detection circuit for detecting the error between the actual rotation speed of the optical disk and the reference rotation speed, which is used during the CAV rotation control operation, is provided as CLV.
It is also used during rotation control operation. Specifically, when the difference obtained by the rotation error detection circuit for CAV is larger than a threshold value during the operation of the CLV rotation control, the control voltage is set so that the maximum current is supplied to the spindle motor, When the difference becomes smaller than the threshold value, the same C as in the conventional example based on the error between the synchronization signal synchronized with the data pattern of the optical disc and the CLV reference rotation signal.
The control is switched to the control using the rotation error detection circuit for LV.
Therefore, the rotation error detection circuit for CAV is also used for CLV rotation control to perform rotation control. This makes it possible to use the unused portion of the circuit and quickly pull in the rotation speed.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below with reference to the drawings showing the embodiments thereof.

(First Embodiment) FIG. 1 is a block diagram showing a configuration example of a rotation control device according to a first embodiment of the present invention. In FIG. 1, reference numeral 21 is an optical disc to be reproduced,
The optical disc 21 is rotated by a spindle motor 22.
Below the optical disc 21, an optical head 1 for irradiating a converged spot of a laser beam onto the optical disc 21 and obtaining a reproduction signal from the reflected light is provided in an actuator 23. The actuator 23 moves the optical head 1 in the radial direction of the optical disc 21 under the control of the MPU 7.

The optical head 1 uses the read reproduction signal as a PL.
Output to the L circuit 2. The PLL circuit 2 extracts a data pattern synchronization signal from the read data reproduction signal on the optical disc 21 and outputs it to the CLV rotation error detection circuit 3. The CLV rotation error detection circuit 3 uses this synchronization signal and CL
An error signal from the V reference signal is obtained and output to the CLV control voltage output circuit 4. The CLV control voltage output circuit 4 converts this error signal into a control voltage and outputs it to the adder 10. Adder
Reference numeral 10 adds the input from the CLV control voltage output circuit 4 and the input from the comparator 11 described later, and outputs the addition result to the control voltage selection circuit 6.

The spindle motor drive circuit 5 outputs a rotation signal indicating the rotation speed of the spindle motor 22 to the CAV rotation error detection circuit 8. The CAV rotation error detection circuit 8 obtains an error signal between this rotation signal and the CAV reference signal, and CA
Output to the V control voltage output circuit 9. The CAV control voltage output circuit 9 converts the error signal into a control voltage, and the converted control voltage is used in the control voltage selection circuit 6 during the CAV rotation control.
In addition, during CLV rotation control, it outputs to the comparator 11, respectively. Further, the MPU 7 outputs to the comparator 11 a voltage corresponding to the reference rotation error signal from the rotation speed of the target track during CLV rotation control.

The comparator 11 has a CAV during CLV rotation control.
The input voltage from the control voltage output circuit 9 and the input voltage from the MPU 7 are compared with each other to determine whether the difference between the input voltages is within a predetermined threshold value. , A control voltage that causes the maximum current to flow through the spindle motor 22 is output to the adder 10. When the difference between these input voltages is within a predetermined threshold value, the comparator 11 outputs nothing to the adder 10.

Under the control of the MPU 7, the control voltage selection circuit 6 selects the output (control voltage) from the adder 10 during CLV rotation control, and the output (control voltage) from the CAV control voltage output circuit 9 during CAV rotation control. ) Is selected, and the selected control voltage is output to the spindle motor drive circuit 5. The spindle motor drive circuit 5 drives the spindle motor 22 according to this control voltage to control the rotation speed of the optical disk 21.

Therefore, in the first embodiment, these optical head 1, PLL circuit 2, CLV rotation error detection circuit 3, CLV control voltage output circuit 4, spindle motor drive circuit 5, control voltage selection circuit shown in FIG. 6, MPU7, C
AV rotation error detection circuit 8, CAV control voltage output circuit 9,
The adder 10 and the comparator 11 form a CLV rotation control system. On the other hand, the spindle motor drive circuit 5, control voltage selection circuit 6, MPU 7, CAV rotation error detection circuit 8 and CAV control voltage output circuit 9 constitute a CAV rotation control system. The basic configuration of this CAV rotation control system is the same as the conventional example.

Next, the operation will be described. First, the operation of CLV rotation control, which is a characteristic part of the present invention, will be described.

When the MPU 7 outputs a command to move the optical head 1 to the actuator 23, the actuator 23 moves the optical head 1 to the target track. At this time, a voltage corresponding to a reference rotation error signal based on the rotation speed of the target track is output from the MPU 7 to the comparator 11. Also,
An error signal is obtained from the spindle rotation pulse signal output from the spindle motor drive circuit 5 by the CAV rotation error detection circuit 8, and the error signal is converted into a voltage by the CAV control voltage output circuit 9 and output to the comparator 11. It Comparator 11
The two inputs are compared with each other, and the control voltage that allows the maximum current to flow through the spindle motor 22 is output from the comparator 11 to the adder 10 until the difference becomes within a predetermined threshold value.
When the difference is within a predetermined threshold value, nothing is output from the comparator 11 to the adder 10.

On the other hand, the PLL circuit 2 extracts a data pattern synchronization signal from the data reproduction signal on the optical disk 21 output from the optical head 1. An error signal is obtained by the CLV rotation error detection circuit 3 from the synchronization signal and the rotation reference signal, then converted into a control voltage by the CLV control voltage output circuit 4, and input to the adder 10. And the comparator
11 and the control voltage from the CLV control voltage output circuit 4 are added. Here, the MPU 7 is the CL of the control voltage selection circuit 6.
The V control side (the output of the adder 10) is selected, and the added value is output to the spindle motor drive circuit 5 via the control voltage selection circuit 6 for controlling the rotation of the spindle motor 22.

As described above, when the difference between the reference voltage from the MPU 7 and the voltage from the CAV control voltage output circuit 9 is larger than the threshold value during the CLV rotation control operation,
If the control voltage is set so that the maximum current flows to the spindle motor 22, and the difference becomes smaller than the threshold value,
The control is switched to the control using the CLV rotation error detection circuit 3 and the CLV control voltage output circuit 4 similar to the conventional example based on the error between the signal synchronized with the data pattern of the optical disk 21 and the reference rotation signal. During the CLV rotation control, the CAV rotation error detection circuit 8 and the CAV control voltage output circuit 9, which have not been used in the conventional example, can be used to quickly pull in the rotation speed during the movement of the optical head 1.

Next, the operation of CAV rotation control will be described. An error signal is obtained in the CAV rotation error detection circuit 8 from the spindle rotation signal output from the spindle motor drive circuit 5 and the reference signal. Then, the error signal is converted into a control voltage by the CAV control voltage output circuit 9. Here, the MPU 7 selects the CAV control side (output of the CAV control voltage output circuit 9) of the control voltage selection circuit 6, and the control voltage is input to the spindle motor drive circuit 5 via the control voltage selection circuit 6. It The operation of the CAV rotation control is the same as that of the conventional example described above.

(Second Embodiment) FIG. 2 is a block diagram showing a configuration example of a rotation control device according to a second embodiment of the present invention. In FIG. 2, parts given the same numbers as in FIG. 1 indicate the same or corresponding parts, and therefore their explanations are omitted.

In the second embodiment shown in FIG. 2, the difference between the rotation speed of the spindle motor 22 and the target rotation speed is directly obtained by the MPU 7 during the CLV rotation control operation, and the difference is a predetermined threshold value. When it exceeds, a control voltage that causes the maximum current to flow to the spindle motor 22 is directly output from the MPU 7 to the adder 10.

The operation of CLV rotation control in the second embodiment will be described. When the MPU 7 outputs a command to move the optical head 1 to the actuator 23, the actuator 23 moves the optical head 1 to the target track. A spindle rotation pulse signal is input from the spindle motor drive circuit 5 to the MPU 7, and the current rotation speed is calculated.
The difference between the calculated rotation speed and the target rotation speed is MPU.
The MPU 7 outputs to the adder 10 a control voltage that causes a maximum current to flow through the spindle motor 22 until the difference is within a predetermined threshold value. When the difference is within a predetermined threshold value, the MPU 7 outputs nothing to the adder 10.

On the other hand, as in the case of the above-described first embodiment, the control voltage corresponding to the CLV rotation error signal is added by the adder 10.
Is input to Then, the control voltages from the MPU 7 and the CLV control voltage output circuit 4 are added. Where MPU
7 selects the CLV control side (output of the adder 10) of the control voltage selection circuit 6, and the added value is the spindle motor 22.
Is output to the spindle motor drive circuit 5 via the control voltage selection circuit 6 for controlling the rotation of the.

Since the operation of the CAV rotation control in the second embodiment is the same as that in the above-described first embodiment and the conventional example, the description thereof will be omitted.

In the second embodiment, the MPU 7 finds the difference between the actual rotation signal of the spindle motor 22 and the rotation reference signal during the CLV rotation control operation. If the difference is larger than the threshold value, Maximum current to spindle motor 22
When the control voltage is set so as to flow to the CLV and the difference becomes smaller than the threshold value, the CLV rotation error similar to the conventional example based on the error between the signal synchronized with the data pattern of the optical disk 21 and the reference rotation signal. The control is switched to the control using the detection circuit 3 and the CLV control voltage output circuit 4.

Therefore, like the first embodiment, it becomes possible to quickly pull in the rotation speed during the movement of the optical head 1, and instead of the CAV rotation error detection circuit 8, the CAV control voltage output circuit 9 and the comparator 11. In addition, since the control voltage is output using the existing MPU 7, the first embodiment
It is possible to reduce the circuit scale as compared with. However, since the load on the MPU 7 is larger than that of the first embodiment,
The access time as a whole does not necessarily become short.

[0032]

As described above, in the present invention, the rotation control can be performed by using the circuit which has been conventionally used only for the CAV rotation control, also for the CLV control, so that the rotation control can be performed. It is possible to quickly pull in the rotation speed by using the unused portion of the conventional. In addition, the existing M
If the control voltage is calculated by the internal calculation of PU, the circuit can be downsized.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a configuration example of a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration example of a second embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration example of a conventional rotation control device.

[Explanation of symbols]

 1 Optical Head 2 PLL Circuit 3 CLV Rotation Error Detection Circuit 4 CLV Control Voltage Output Circuit 5 Spindle Motor Drive Circuit 6 Control Voltage Selection Circuit 7 MPU 8 CAV Rotation Error Detection Circuit 9 CAV Control Voltage Output Circuit 10 Adder 11 Comparator 21 Optical Disk 22 Spindle motor 23 Actuator

Claims (2)

[Claims] 1. A CAV rotation control or a CLV rotation control is selectively performed on a disk to detect an error between an actual disk rotation speed and a predetermined rotation speed used when the CAV rotation control is executed. A disk rotation control device having an error detection circuit, wherein the error detection circuit is configured to be used even when the CLV rotation control is executed. 2. In a rotation control method of a disk rotation control device for selectively performing CAV rotation control or CLV rotation control on a disk, when the CLV rotation control is performed, the actual number of rotations of the disk and a predetermined value. A rotation control device for a disc, characterized in that the rotation of the disc is controlled so as to increase or decrease the predetermined rotation speed while the absolute value of the difference is larger than a predetermined value. Rotation control method.