JP2001344891A - Disk-like recording medium drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disk-like recording medium drive device which is capable of dealing with a CLV control system and a CAV control system with relatively simple constitution. SOLUTION: This drive device has an encoder which forms pulse signals proportional to the rotating speed of the disk-like recording medium, a synchronous clock forming means which forms synchronous clock signals according to the quantity of the information to be read out or written, a CLV reference signal forming means which forms the pulse signals proportional to a linear speed in accordance with the synchronous clock signals from the synchronous clock signal forming means and an FG servo circuit which controls the pulse signals inputted from the encoder and the CLV reference signal forming means so as to appear at specified intervals. The input signals to the FG servo circuit are changed over between the pulse signals from the encoder and the pulse signals from the CLV reference signal forming means in accordance with the prescribed information reading out or writing position on the disk-like recording medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk-shaped recording medium drive for reading or writing information while rotating a disk-shaped recording medium.

[0002]

2. Description of the Related Art Conventionally, a unit for controlling information reading or writing of a disk-shaped recording medium (hereinafter, referred to as a disk) for recording reproduction information at a constant density on a spiral track, such as a CD or a DVD, has been described. Track length read or written by pickup at time (so-called linear velocity)
And the CLV control method for changing the rotation speed on the inner and outer circumferences of the disk, and the CLV control method for keeping the rotation speed of the disk constant and the information read or written on the inner and outer circumferences of the disk. C to change transfer speed
An AV control method is known. In general, a disk drive device adopting the CLV control method monitors the linear velocity in real time, and adjusts the linear velocity to be constant, thereby changing the rotation speed based on the information reading or writing position on the disk. It has a configuration. On the other hand, C
A disk drive device adopting the AV control system monitors the rotation speed of a disk in real time, adjusts the rotation speed to a constant value, and adjusts the rotation speed according to the amount of information read or written per unit time. -It has a configuration to adjust the execution speed of the write signal processing.

By the way, the above-mentioned CLV control system and CA
A disk drive employing either of the V control methods
Since it does not involve a change in the control method, it has a relatively simple configuration, but each has its own problems. In the CLV control system, since the work of accelerating and decelerating the rotating shaft of the spindle motor that drives the disk to rotate is required at all times, a load is continuously applied to the rotating shaft. Power consumption increases. On the other hand, in the CAV control method,
The amount of information read or written is small, and
On the outer peripheral side of the disc, signal processing such as information transfer processing may not be able to keep up.

Conventionally, as a device for suppressing such a problem, a disk drive device capable of arbitrarily changing the CLV control system and the CAV control system, or performing CAV control on the inner peripheral side of the disk to obtain the disk radial direction. Control system that performs CLV control from the specified position in the outer circumference
2. Description of the Related Art A disk drive device that can support both the CLV control method and the CAV control method, such as a disk drive device that can execute a so-called partial CAV control method, is known. In such a disk drive device, a CLV control circuit and a CAV control circuit are usually separately provided, and these circuits are switched and used based on the information read or write position on the disk. . In connection with this, for example, JP-A-9-73715 (Japanese Patent No. 2809206), JP-A-10-92100 and JP-A-10-106136 can cope with the CLV control method and the CAV control method. A disk drive is disclosed.

[0005]

However, in a disk drive capable of supporting both the CLV control system and the CAV control system which are conventionally known, two different systems are switched based on a read or write position on a disk. At the time of switching, the rotation speed of the spindle motor may be rapidly changed. In this case, there is a possibility that a difference occurs between the information to be read or written and the synchronous clock signal generated according to the amount of the information. This is particularly inconvenient when writing information to a disk, and is difficult to use for a recording medium such as a CD-R that cannot be rewritten.

An object of the present invention is to provide a relatively simple configuration and a C
It is an object of the present invention to provide a disk-shaped recording medium driving device and method that can support the LV control method and the CAV control method. Another object of the present invention is to provide a disk-shaped recording medium driving apparatus and method capable of realizing stable reading and writing of information when switching a control method.

[0007]

The invention according to claim 1 of the present application reads or writes information while rotating a disk-shaped recording medium on which information is recorded at a constant density on a spiral track. In a disk-shaped recording medium driving device, an encoder that generates a pulse signal proportional to the rotation speed of the disk-shaped recording medium, and a synchronization that generates a synchronous clock signal in accordance with the amount of information read or written in the disk-shaped recording medium A clock generating means, and a CLV for generating a pulse signal proportional to the linear velocity based on a synchronous clock signal from the synchronous clock generating means.
A reference signal generating means, an FG servo circuit for controlling the pulse signals input from the encoder and the CLV reference signal generating means to appear at regular intervals, and an input signal to the FG servo circuit on a disk-shaped recording medium. And a switch for switching between a pulse signal from the encoder and a pulse signal from the CLV reference signal generating means based on the predetermined information reading or writing position.

According to this configuration, a pulse signal proportional to the rotation speed is input from the encoder to the FG servo circuit, and the pulse signal is controlled so as to appear at regular intervals, thereby realizing the CAV control method. . On the other hand, F
When a pulse signal proportional to the linear velocity is input from the CLV reference signal generation means to the G servo circuit, the pulse signal is controlled so as to appear at regular intervals.
The LV control method is realized. The disk-shaped recording medium driving device has a relatively simple configuration and is low in cost,
It is possible to support the control system and the CLV control system.

Further, according to a second aspect of the present invention, in the first aspect of the present invention, the switch is set so that a pulse signal from an encoder is input to an FG servo circuit, and the CAV control system is used. The pulse signal from the encoder is used to generate the CLV reference signal so that the CLV reference signal generation means operates in phase with the pulse signal from the encoder while reading or writing information from or to the disk-shaped recording medium is controlled. It is characterized by having a configuration for inputting to means.

According to this configuration, when the CAV control method is adopted on the inner peripheral side of the disk-shaped recording medium, the CLV
A reference signal generator operates to receive the pulse signal from the encoder and align it with the pulse signal. Thus, when switching to the CLV control method, the frequency of the input signal to the FG servo circuit can be maintained substantially constant, and the rotation speed of the disk can be smoothly changed.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. In the following description, as a disk-shaped recording medium, for example, CD, DV
D or the like that records information at a constant density on a spiral track is used. Embodiment 1 FIG. FIG. 1 is a block diagram illustrating a configuration of a disk drive device according to an embodiment of the present invention. The disk drive device 10 includes a spindle motor 2 that rotationally drives a disk-shaped recording medium (hereinafter, referred to as a disk) 1,
The rotation speed of the spindle motor 2, that is, the disk 1
An encoder 3 for generating a pulse signal having a frequency proportional to the rotation speed of the optical disk 1 and a pickup for reading out information recorded on the disk 1 with a laser beam (P in FIG.
U) 4, reproduction signal detecting means 5 for detecting information read by the pickup 4 as a binary signal, and synchronous clock generating means 6 for generating a synchronous clock signal according to the amount of detected information. A servo means 7 for performing tracking servo control and focusing servo control of the pickup 4 based on the information detected by the reproduction signal detection means 5; a laser driving means 8 for driving a laser device included in the pickup 4; Information signal detected by means 5 and synchronous clock generating means 6
Receiving the synchronous clock signal generated by
A reproduction / recording signal processor 9 for performing signal processing for recording.

Further, the disk drive 10 receives a synchronous clock signal from the synchronous clock generating means 6 and generates a reference clock signal used for the CLV control. 14, an FG servo circuit 13 for controlling the spin doll motor 2 based on an input signal, a reference clock signal from a CLV reference signal generator 20, and an encoder 3. A switching unit 12 for switching an input signal to the FG servo circuit 13 between the pulse signal and the rotation driving unit 17 for controlling the drive of the spindle motor 2.

The disk drive 10 having such a configuration
In accordance with the CAV control method and the CV control method, the method of controlling the information reading or writing of the disk 1 according to the setting of the switch 12 is described.
Switching is made between the LV control method. That is, when the switch 12 is set so that the pulse signal from the encoder 3 is input to the FG servo circuit 13, the disk drive device 10 controls the information reading or writing of the disk 1 by the CAV control method. At this time, the pulse signal input from the encoder 3 to the FG servo circuit 13 is shaped via the waveform shaper 14 and then the rotation speed detector 15
The rotation speed detector 15 detects the rotation speed of the spindle motor 2 (that is, the rotation speed of the disk 1) from the pulse signal. The spindle servo means 16
While referring to a predetermined rotation frequency set in advance, the interval between the input pulse signals proportional to the rotation speed of the disk 1 becomes constant, that is, the rotation speed detected by the rotation speed detector 15 becomes constant. Generate the acceleration / deceleration signal
Output to the rotation drive unit 17. The rotation drive unit 17 drives and controls the spindle motor 2 based on the input acceleration / deceleration signal.

As described above, in the disk drive device 10, when reading or writing of information on the disk 1 is controlled by the CAV control method, the rotational speed of the disk 1 is monitored and adjusted in real time, and Disc 1 regardless of the information read or write position
Can be kept constant. In this case, since the linear velocities on the inner and outer sides of the disk 1 are different from each other, the amount of information read out by the pickup 4 per unit time is different. Then, a synchronous clock signal according to the amount of information to be read is generated by the synchronous clock generating means 6, and the synchronous clock signal is used as a reference clock signal by the reproduction / recording signal processor 9. Thereby, the reproduction / recording signal processor 9 can change the processing speed of the reproduction / recording signal according to the change in the amount of information to be read.

On the other hand, when the switch 12 is set so that the reference clock signal from the CLV reference signal generator 20 is input to the FG servo circuit 13, the disk drive 10 operates in the CLV control system. It controls reading or writing of information on the disk 1. The reference clock signal input to the FG servo circuit 13 is a pulse signal generated by the CLV reference signal generator 20 and proportional to the synchronous clock signal from the synchronous clock generator 6. At this time, F
The spindle servo unit 16 in the G servo circuit 13 controls the rotation of the rotation speed detector 15 so that the interval between the pulse signals proportional to the synchronization clock signal from the synchronization clock generation unit 6 becomes constant. An acceleration / deceleration signal is generated so as to output to the rotation drive unit 17. At the time of this CLV control, the rotation speed detector 15 detects a linear speed by reading or writing information from / to the disk 1. The rotation drive unit 17 controls the drive of the spindle motor 2 based on the acceleration / deceleration signal input from the spindle servo unit 16.

As described above, in the disk drive device 10, when the information reading or writing of the disk 1 is controlled by the CLV control method, the linear velocity by reading or writing is controlled by:
By detecting the synchronous clock signal from the synchronous clock generator 6 and monitoring and adjusting the synchronous clock signal, the linear velocity can be kept constant at any information reading or writing position on the disk 1. At this time,
The reproduction / recording signal processor 9 processes the read information at a constant speed. In this case, since the linear velocity is kept constant, the rotational speed of the disk 1 is changed in accordance with the movement of the reading or writing position on the disk 1. That is, as the reading or writing position on the disk 1 approaches the inner peripheral side of the disk 1, the rotation speed of the disk 1 increases. When the reading or writing of the disk 1 is controlled by the CLV control method, the synchronous clock signal cannot be read if the disk 1 is in a rotation stop state at the start of the rotation driving of the disk 1. 1 until the rotation speed reaches a predetermined value.
A G servo circuit 13 is used.

FIG. 2 is a block diagram showing the configuration of the CLV reference signal generator 20. This CLV reference generator 2
0 is a counter 24 for counting the synchronous clock signal input from the synchronous clock generating means 6;
4 is compared with a predetermined coefficient K, and when both are equal, a predetermined pulse signal is output to the FG servo circuit 1.
And a comparator 25 for outputting the data to the comparator 3. When controlling the information reading or writing of the disk 1 by the CLV control method, the pulse signal output from the comparator 25 is converted into a pseudo signal of the pulse signal generated by the encoder 3 (a pseudo FG signal in the figure) by the FG. Input to the servo circuit 13. At this time, a part of the pulse signal output from the comparator 25 is returned to the counter 24, whereby the counting operation is reset.

Here, the predetermined information reading or writing position on the disk 1 is determined by a distance r from the center in the radial direction.
Where the rotational speed of the spindle motor 2 under the CLV control at the position r is a rotational frequency F, and the magnitude of the synchronous clock signal generated by the synchronous clock generating means 6 at the position r is a frequency f. ,
The coefficient K input to the comparator 25 is given by the following equation. K = C · F / f C is a fixed value consisting of a ratio between the rotation frequency of the spindle motor 2 and the corresponding frequency of the pulse signal from the encoder 3. When reading or writing information on the disk 1 is controlled by the CLV control method, the disk 1 is driven at a constant linear velocity based on the linear velocity at a predetermined position r. The information reading or writing position r is set on the disk 1
Any value may be taken as long as the upper recording layer exists.

As described above, in the disk drive 10, the input signal to the CLV reference signal generator 20 and the FG servo circuit is transmitted to the device operating in the CAV control system.
Only by adding a switch 12 for switching between a reference clock signal from the CLV reference signal generator 20 and a pulse signal from the encoder 3, a CAV control method and a CLV with a relatively simple configuration and at low cost. It is possible to correspond to a control method, and by changing the setting of the switch 12, these control methods can be arbitrarily switched.

Embodiment 2 FIG. 3 is a block diagram showing a configuration of the disk drive device according to Embodiment 2 of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and further description is omitted. The disk drive device 30 has substantially the same configuration as the device 10 according to the first embodiment. In the second embodiment, the disk drive device 30 further includes a switch 12 for switching an input to the FG servo circuit 13 and a CLV reference signal. For generator 40,
It has a CAV / CLV switching signal generator 50 that outputs a predetermined switching signal. In the disk drive device 30 having such a configuration, the CAV control method is adopted on the inner peripheral side of the disk 1, and a predetermined position r on the disk 1 is set in advance.
The CLV control method is adopted on the outer peripheral side from the position r with reference to
As in the case of the above, the input to the FG servo circuit 13 is supplied to the CLV reference signal generator 4 via the switch 12 based on the pulse signal from the encoder 3 and the synchronous clock signal.
By switching between the pulse signal generated by “0” and the pulse signal generated by “0”, the CAV control method and the CLV control method are switched.

First, when the switch 12 is set so that a pulse signal from the encoder 3 is input to the FG servo circuit 13, the disk drive 30 reads or writes information on the disk 1 by the CAV control method. Control.
At this time, the spindle servo means 16 in the FG servo circuit 13 refers to a predetermined rotation frequency set in advance, so that the interval between input pulse signals proportional to the rotation speed of the spindle motor 2 becomes constant. That is, an acceleration / deceleration signal is generated so that the rotation speed detected by the rotation speed detector 15 becomes constant, and is output to the rotation drive unit 17.

While the CAV control method is adopted, the above CA
The V / CLV switching signal generator 50 receives the pulse signal from the encoder 3 and the synchronous clock signal from the synchronous clock generator 6, and outputs a rotation speed detected from the pulse signal and a line detected from the synchronous clock signal. The relative speed to the speed is monitored. When information reading or writing is performed at a predetermined position r on the disk 1, the CAV / CLV switching signal generator 50 detects a predetermined relative speed set in advance, and accordingly, the switching unit 12 and a switch signal to the CLV reference signal generator 40.

FIG. 4 is a block diagram showing the configuration of the CLV reference signal generator 40. The CLV reference signal generator 40 outputs the reset input signal to the counter 24 in addition to the pulse signal from the encoder 3 and the pulse signal from the comparator 25 in addition to the counter 24 and the comparator 25 as in the first embodiment. And a switch 41 for switching between a part of the pseudo signal returned after the output of. This switching unit 4
Reference numeral 1 denotes a pulse signal (FG in the figure) from the encoder 3 when the CAV control method is adopted on the inner peripheral side of the disk 1.
Signal is set to be input to the counter 24, and when the CLV control method is employed on the outer peripheral side of the disk 1, a part of the pseudo signal returned after the output from the comparator 25 is input to the counter 24. Is set to In the CLV reference signal generator 40, the position r on the disk 1 as a reference when calculating the coefficient K input to the comparator 25 is not arbitrarily set, but is set to a switching position between the CAV control method and the CLV control method. Is done.

The CLV reference signal generator 40 having such a configuration receives the pulse signal from the encoder 3 and adjusts the phase with the pulse signal when the CAV control system is adopted on the inner peripheral side of the disk 1. Operate. Thereby, when switching to the CLV control method, the frequency of the input signal to the FG servo circuit 13 can be maintained substantially constant, and the rotation speed of the spindle motor 2 (that is, the rotation speed of the disk 1) can be smoothly changed. . as a result,
There is no synchronization deviation between the synchronization clock signal and the rotation speed,
Information reading errors and writing errors are reduced, and stable information reading and writing accuracy can be realized.

The present invention is not limited to the illustrated embodiment, and it goes without saying that various improvements and design changes can be made without departing from the spirit of the present invention.

[0026]

As is apparent from the above description, according to the first aspect of the present invention, while rotating a disk-shaped recording medium on which information is recorded at a constant density on a spiral track, In a disk-shaped recording medium drive for reading or writing information, a CAV control system and a CLV control system can be supported with a relatively simple configuration and at low cost, and the control systems can be arbitrarily switched.

According to the invention of claim 2 of the present application, when switching from the CAV control method to the CLV control method,
The frequency of the input signal to the FG servo circuit can be maintained substantially constant, and the rotation speed of the disk-shaped recording medium can be smoothly changed. As a result, there is no synchronization deviation between the synchronous clock signal and the rotation speed, and information reading errors and writing errors are reduced, and stable information reading and writing accuracy can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a disk-shaped recording medium driving device according to Embodiment 1 of the present invention.

FIG. 2 is a block diagram showing a configuration of a CLV reference signal generator included in the disk-shaped recording medium driving device according to the first embodiment.

FIG. 3 is a block diagram showing a configuration of a disk-shaped recording medium driving device according to Embodiment 2 of the present invention.

FIG. 4 is a block diagram showing a configuration of a CLV reference signal generator included in the disk-shaped recording medium driving device according to the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Disk-shaped recording medium 2 ... Spindle motor 3 ... Encoder 4 ... Pickup 6 ... Synchronous clock generation means 10 ... Disk drive 12, 41 ... Switch 13 ... FG servo circuit 20, 40 ... CLV reference signal generator 24 ... Counter 25: comparator 50: CAV / CLV switching signal generator

Claims (2)

[Claims] 1. A disk-shaped recording medium driving device for reading or writing information while rotating a disk-shaped recording medium on which information is recorded at a constant density on a spiral track, wherein: An encoder for generating a pulse signal proportional to the rotation speed; a synchronous clock generating means for generating a synchronous clock signal in accordance with the amount of information read or written on the disk-shaped recording medium; CLV reference signal generating means for generating a pulse signal proportional to the linear velocity based on a synchronous clock signal; and an FG servo circuit for controlling the pulse signals input from the encoder and the CLV reference signal generating means to appear at regular intervals. And an input signal to the FG servo circuit on a disk-shaped recording medium. A switch for switching between a pulse signal from the encoder and a pulse signal from the CLV reference signal generating means based on a fixed information reading or writing position. apparatus. 2. The switch is set so that a pulse signal from an encoder is input to an FG servo circuit.
The pulse signal from the encoder is controlled so that the CLV reference signal generation means operates in phase with the pulse signal from the encoder while information reading or writing on the disk-shaped recording medium is controlled by the V control method. 2. The disk-shaped recording medium driving device according to claim 1, wherein the disk-shaped recording medium driving device has a configuration for inputting to a reference signal generating means.