JPH10228722A - Disk drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform rotational servo control of the CAV(constant angular velocity) system at low cost and with high accuracy. SOLUTION: A fine clock mark signal formed at fixed intervals in a wobbling groove of a disk D is extracted, and a period of a timing signal corresponding to this fine clock mark signal is counted. Then, the rotation of a spindle motor 6 is controlled with a difference value between this count value and a target value corresponding to a target revolving speed of the spindle motor 6 as a spindle motor error signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk drive for driving a disk-shaped recording medium.

[0002]

2. Description of the Related Art CDs (compact disks) are widely used as optical disk recording media, and CD-type disks are used in various fields including music applications. Music CDs are usually read-only media, but write-once discs called CD-Rs (Compact Disc-Recordable) have also been developed.

On the other hand, a DVD (Digital Versatile Disc) is used as an optical disc recording medium suitable for multimedia applications.
/ Digital Video Disc) has also been developed. It has been proposed that DVDs be adapted in a wide range of fields such as video data, audio data, and computer data. Although the DVD is a disk (diameter 12 cm) of the same size as a CD, the recording capacity has been remarkably increased due to a smaller recording track pitch and a data compression technique. And this DVD is a read-only DVD
Types such as a ROM, a DVD-R that can be written only once, and a DVD-RAM that can be rewritten any number of times have been proposed.

In a disk drive device for recording / reproducing a DVD, a so-called CAV system is employed in which the disk is rotated at a constant angular velocity in order to read or write data (main data) recorded on the disk. ing.

[0005] To perform the rotary servo control of the CAV method,
For example, rotation error information is obtained by comparing a speed detection signal obtained from a DC brushless motor used for a spindle motor for rotating a disk with a reference clock obtained from a crystal or the like. The rotation error information is fed back to a spindle motor for rotating the disk, thereby obtaining a rotation state at a constant angular velocity. Note that the speed detection signal obtained from the DC brushless motor includes a signal obtained from a Hall element provided for creating the switching timing of the three-phase coil and a signal detecting a change in the back electromotive force of the coil itself. .

[0006]

However, when a signal obtained from the DC brushless motor is used as a speed detection signal, only about 4 to 6 speed detection signals can be obtained per rotation of the disk. For this reason, assuming that four speed detection signals are obtained per rotation of the disk and the number of rotations of the disk is 2068 rpm, the sampling frequency of the speed detection signal is about 138 Hz and the servo band is narrow. Therefore, there is a disadvantage that the rotation accuracy of the spindle motor is not so good.

In order to improve the rotation accuracy of the spindle motor, an FG sensor may be mounted coaxially with the spindle motor to detect the speed of the spindle motor. Had the problem of rising.

Further, the rotation speed of the disk surface irradiated with the laser beam may be different from the actual rotation speed of the spindle motor due to the influence of the eccentricity of the disk, surface fluctuation, or the like. For this reason, when data is written to the disk once by the disk drive device, the disk is taken out and set again, for example, the linear speed of the disk becomes different from the linear speed at the time of writing the data. In some cases, the allowable error of the linear velocity is exceeded, and the PLL circuit for obtaining a reproduction clock for reproducing data cannot be locked into a locked state, so that an appropriate reproduction clock cannot be generated and data cannot be reproduced. I was afraid.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a disk drive device capable of performing high-accuracy rotational servo control without increasing costs.

[0010]

In order to achieve the above object, predetermined control information is modulated by a predetermined method, and a groove area wobbled based on a signal to which a specific mark signal is added at regular intervals. A disk drive device that performs a recording or reproducing operation on a disk-shaped recording medium having: a rotation driving unit that rotationally drives the disk-shaped recording medium; and a predetermined interval between read signals corresponding to wobbling of a groove area of the disk-shaped recording medium. A mark detection means for extracting a specific mark signal included in the mark signal and outputting a timing signal corresponding to the mark signal; a target count value setting means for setting a target count value corresponding to a target rotation speed of the rotation driving means; Outputs the difference between the count value obtained by counting the period of the timing signal and the target count value as rotation error information A rotation error information output unit that was so and a rotation control means for controlling the rotational speed of the rotary drive means on the basis of the rotation error information. The mark detecting means extracts a clock mark signal added for clock reproduction as a specific mark signal included at a predetermined interval in the read signal.

Also, a control information unit having a predetermined data length is continuously formed with control information, and the control information is wobbled based on a signal modulated by a predetermined method. A disk drive device that performs a recording or reproducing operation on the disk drive, a rotation driving unit that rotates the disk-shaped recording medium, and a read timing of each control information unit from a read signal corresponding to wobbling of a groove area of the disk-shaped recording medium. An information unit detecting means for outputting a timing signal, a target count value setting means for setting a target count value corresponding to a target rotation speed of the rotation driving means, a count value obtained by counting the period of the timing signal, and a target count value. A rotation error information output means for outputting a difference value between the rotation error information and the rotation error information, And so and a rotation control means for controlling the rotational speed of the rotary drive means. Further, the information unit detecting means detects a synchronization pattern added to each information unit as a timing signal of each control information unit.

Also, a disk drive device for performing a recording or reproducing operation on a disk-shaped recording medium having a groove area wobbled based on a signal obtained by modulating predetermined control information at a predetermined carrier frequency is provided. Rotation driving means for driving the recording medium to rotate, wobble carrier extracting means for extracting a wobbling carrier frequency in a groove area of the disc-shaped recording medium,
Target frequency setting means for setting a target frequency corresponding to a target rotation value of the rotation drive means; rotation error information output means for outputting rotation error information as a result of comparison between the carrier frequency and the target frequency; and rotation based on the rotation error information. Rotation control means for controlling the rotation speed of the driving means.

According to the present invention, the rotation error information of the rotation driving means is obtained from the various information formed in the wobbling groove area of the disk-shaped recording medium (that is, the rotation error information is obtained by using the information on the disk). Therefore, other detection mechanisms are not required, and the detection information per unit time is increased, and the rotation accuracy of the rotation drive unit can be improved.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in the following order, taking a disk drive device corresponding to a DVD-RAM as an example. 1. 1. Groove structure of DVD-RAM 2. Configuration of playback system and servo system of disk drive device 3. Configuration and operation of spindle servo system according to first embodiment 4. Configuration and operation of spindle servo system according to second embodiment Configuration and operation of a spindle servo system according to a third embodiment

1. Groove Structure of DVD-RAM FIG. 1 schematically shows a structure of an area of the DVD-RAM where data (main data and the like) is recorded. As shown in this figure, the data recordable area of the DVD-RAM has
Slightly meandering (wobbled) groove (groove) 10
1 is formed. The wobbling is set to 2880 waves per one rotation of the disk. Hereinafter, in this specification, a wobbled groove is referred to as a wobble groove.

The wobbling shape given to the groove is based on a signal obtained by FM-modulating predetermined control information including an address and the like. That is, a signal for cutting a groove at the time of cutting the disc (during production of the master) is fluctuated by a signal obtained by FM-modulating the control information described below. Therefore, control information such as an address is expressed in the groove, and information such as an address can be obtained from a signal corresponding to the wobble state of the wobble groove during disk drive.

The format of control information (wobble data) represented by a wobble groove is shown in FIGS. In addition. This is a format of wobble data, not a format of main data recorded on the groove. The format of the wobble data is, as shown in FIG.
Divided into servo segments (segment
0 to segment 7). Therefore, the wobbling per servo segment is 360 waves. Also, in the segment 0 to segment 7, 48-bit wobble data as shown in FIG. 2B is FM-modulated to form a wobble groove. The 48-bit wobble data format will be described later.

In the wobble groove, fine clock marks for generating a reference clock at the time of data recording by a PLL circuit are formed at regular intervals. 96 fine clock marks (hereinafter simply referred to as "clock marks") are formed per rotation of the disk, and therefore, 12 clock marks are formed per segment.

FIG. 3A shows the format of 48-bit wobble data expressed by the wobble groove FM modulation. Segme as shown
4-bit synchronization pattern (Sync Mark) for obtaining synchronization for each nt, 4-bit layer number (Layer Null)
mber), a 20-bit track number (Track Number) indicating the address of the track, and se within one track.
g. 0-seg. A 4-bit segment number (Segment Number) indicating the other (segment address) of 7
A 2-bit reserved area and a 14-bit error correction code (CRC) are sequentially formed.

The 4-bit synchronization pattern provided at the head of each segment is bi-phase data for forming 4-bit data with 8 channel bits as shown in FIG. 3B.

2. Configuration of Reproduction System and Servo System of Disk Drive Apparatus FIG. 4 is a diagram showing a main part of a reproduction system and a servo system block of a disk drive apparatus that drives (records / reproduces) the DVD-RAM as described above. In this figure,
The disk D is a DVD-RAM. The disk D is mounted on a turntable 7 and is rotated at a constant angular velocity (CAV) by a spindle motor 6 during a reproducing operation. Then, the data recorded in the groove of the disk D is read by the pickup 1.

The pickup 1 is provided with an optical system most suitable for a DVD. For example, the laser diode 4 serving as a laser light source has an output laser having a center wavelength of 650 nm or 635 nm, and the objective lens 2 has
A = 0.6. The objective lens 2 is held by a biaxial mechanism 3 so as to be movable in a tracking direction and a focus direction.

A data reading operation is performed on the disk D by using the pickup 1. In the pickup 1, information on light reflected from the disk D is detected by a detector 5, and an electric signal corresponding to the amount of received light is detected. And supplied to the RF amplifier 9.

The RF amplifier 9 includes a current-voltage conversion circuit, an amplification circuit, a matrix operation circuit, and the like, and generates a necessary signal based on a signal from the detector 5. For example, an RF signal as reproduction data, a push-pull signal PP for servo control, a focus error signal FE, a tracking error signal TE, a pull-in signal PI as a so-called sum signal
Generate etc.

The detector 5 has a direction as shown in FIG. 5 (a), and is divided into four detectors 5 comprising detectors A, B, C and D.
a in this case, the focus error signal F
E is the output of the detection units A, B, C, and D, (A + C)
It is generated by the operation of-(B + D). Further, the pull-in signal PI = (A + B + C + D). When the push-pull signal PP is generated by the four-divided detector 5a, as shown in FIG. 5B, the outputs of the detectors A, B, C, and D of the detector 5a are subjected to (A
+ D)-(B + C). Further, considering a so-called three-beam method, the tracking error signal TE may be generated by calculating EF by preparing detectors E and F for side spots separately from the quadrant detector shown in FIG.

Various signals generated by the RF amplifier 9 are:
The value is supplied to the value conversion circuit 11 and the servo processor 14. That is, the reproduced RF signal from the RF amplifier 9 is converted to a binarized circuit 11
To push-pull signal PP and focus error signal F
E, the tracking error signal TE, and the pull-in signal PI are supplied to the servo processor 14.

The reproduced RF signal obtained by the RF amplifier 9 is 2
The signal is binarized by the value conversion circuit 11 to be a so-called EFM + signal (8-16 modulated signal), which is supplied to the decoder 12. The decoder 12 reproduces information read from the disk D by performing EFM + demodulation, CIRC decoding, and the like. The decoded data is sent to the interface unit 1
3 to an externally connected device such as a host computer.

The servo processor 14 generates various focus, tracking, sled, and spindle servo drive signals from the focus error signal FE, the tracking error signal TE, the push-pull signal PP, and the like from the RF amplifier 9 to execute a servo operation. .

That is, a focus drive signal according to the focus error signal FE and the tracking error signal TE,
A tracking drive signal is generated, and the two-axis driver 16 is generated.
To supply. The two-axis driver 16 drives the two-axis mechanism 3 by supplying a current based on the focus drive signal and the tracking drive signal to the focus coil and tracking coil of the two-axis mechanism 3 in the pickup 1. As a result, a tracking servo loop and a focus servo loop by the pickup 1, the RF amplifier 9, the servo processor 14, and the two-axis driver 16 are formed.

The servo processor 14 supplies a spindle drive signal generated from the push-pull signal PP to the spindle motor driver 17, which will be described later. The spindle motor driver 17 applies, for example, a three-phase drive signal to the spindle motor 6 according to the spindle drive signal, and causes the spindle motor 6 to perform CAV rotation. In addition, the servo processor 14 generates a spindle drive signal in accordance with a spindle kick (acceleration) / brake (deceleration) control signal SKB from the system controller 11, and also executes operations such as starting or stopping the spindle motor 6 by the spindle motor driver 17. Let it.

The servo processor 14 generates a thread drive signal based on, for example, a thread error signal obtained from a low-frequency component of the tracking error signal TE and an access execution control from the system controller 10 and supplies the thread drive signal to the thread driver 15. . The thread driver 15 responds to the thread drive signal by the thread mechanism 8.
Drive. The sled mechanism 8 is a mechanism for moving the entirety of the pickup 1 in the radial direction of the disc. The sled driver 15 drives the sled motor 8 in accordance with a sled drive signal, so that the pickup 1 can be slid properly.

The laser diode 4 in the pickup 1 is driven by a laser driver 18 to emit laser light. The servo processor 14 controls the system controller 1
Based on the instruction from 0, a laser drive signal for causing the pickup 1 to emit laser light during reproduction or the like is generated and supplied to the laser driver 18. In response, the laser driver 18 drives the laser diode 4 to emit light.

Various operations such as servo and decoding as described above are controlled by a system controller 10 formed by a microcomputer. For example, operations such as reproduction start and end, track access, fast forward reproduction, and fast reverse reproduction are realized by the system controller 10 controlling the operation of the pickup 1 via the servo processor 14.

Next, the configuration and operation of the spindle servo system of the disk drive of the present embodiment will be specifically described. 3. Configuration and Operation of Spindle Servo System According to First Embodiment FIG. 6 shows a configuration (mainly a configuration in the servo processor 14) of a spindle servo system according to the first embodiment. Note that the same parts as those in FIG.
Further, a tracking servo system and a focus servo system which are not directly related to the present invention are simply referred to as a servo circuit 34, and detailed description thereof will be omitted.

The push-pull detection circuit 21 shown in this figure generates a push-pull signal PP from the detection signal detected by the pickup 1. The push-pull detection circuit 21 is provided, for example, in the RF circuit 9 shown in FIG.

A band-pass filter (hereinafter, referred to as "BPF") 22 extracts a clock mark from the push-pull signal PP, and therefore a high-pass filter for sufficiently reducing the frequency (2880 × disk rotation period) component of the wobble groove. It is composed of a filter and a low-pass filter that attenuates unnecessary high-frequency components.

The window generator 23 is a BPF 22
And outputs a window signal for a predetermined period when the level of the signal output from the terminal is equal to or higher than a predetermined threshold level (Th). The zero-cross detector 24 detects a zero-cross point of the signal output from the BPF 22 and outputs a zero-cross signal. The AND circuit 25 includes a window signal from the window generator 23 and the zero-cross detector 2.
And outputs the logical product of the zero-cross signals from the fourth signal.

The oscillator 26 is composed of, for example, a crystal oscillator or the like, and generates and outputs a predetermined reference clock. The counter 27 counts the reference clock from the oscillator 26, and clears the value of the counter immediately after the signal is supplied from the AND circuit 25. The capture register 28 latches the value of the counter 27 when the signal is supplied from the AND circuit 25.

The CPU 29 stores in advance target rotation speed information for rotating the spindle motor 6 at a constant angular speed, and the rotation speed of the rotation speed setting circuit 30 is set based on the target rotation speed information. The difference device 31 compares the value of the counter latched by the capture register 28 with the value set in the rotation speed setting value circuit 30 and outputs the difference value.

The D / A converter 32 converts the difference value of the differentiator 31 into an analog signal and outputs it. A low-pass filter (hereinafter, referred to as “LPF”) 33 reduces high-frequency components in order to reduce the steady-state speed deviation of the analog signal output from the D / A converter 32. The spindle driver 17 amplifies the signal output from the LPF 33 and outputs a spindle drive signal to the spindle motor 6. The servo circuit 34 controls the two-axis mechanism of the pickup 1 based on a tracking error signal and a focus signal detected by the detector of the pickup 1. The circuit blocks surrounded by broken lines are provided in the servo processor 14 in FIG.

Next, the operation of the spindle servo system shown in FIG. 6 will be described with reference to a timing chart shown in FIG. The disk D is a spindle motor 6
It is rotating at a certain rotation speed. The pickup 1 emits a laser beam to the disk from an optical system most suitable for the DVD-RAM, and information on light reflected from the disk D is detected by the detector of the pickup 1. Therefore, servo signals such as a tracking error signal and a focus error signal detected by the detector are supplied to the servo circuit 34, and the servo circuit 34 controls a two-axis mechanism and a thread mechanism provided in the pickup 1. Therefore, it is assumed that the focus servo and tracking servo of the disk D are applied.

The push-pull signal PP detected by the push-pull detection circuit 21 in the state where the focus servo and the tracking servo are applied is as shown in FIG.
The push-pull signal PP is supplied to the BPF 22.

In this case, a signal a obtained by extracting a clock mark component from the push-pull signal PP as shown in FIG. 7A is output from the BPF 22, and this signal a is output to the window generator 23 and the zero-cross detector 24. .

The window generator 23 outputs a window signal b having a predetermined width as shown in FIG. 7B when the signal a is higher than a predetermined level. That is, the window generator 23 outputs the window signal b when detecting the clock mark component included in the supplied signal a. On the other hand, the zero-cross detector 24 outputs a zero-cross signal c as shown in FIG. 7C when detecting the zero-cross point of the signal a. Accordingly, the AND circuit 25 outputs the window signal b as shown in FIG.
The signal d is output only when both the zero cross signal c and the zero cross signal c are supplied. This signal d is supplied to the counter 27 and the capture register 28.

The counter 27 receives the signal d from the AND circuit 25 and the reference clock e from the oscillator 26 as shown in FIG. 7 (e), counts the reference clock e, and outputs the signal from the AND circuit 25. The count value when d is input is output to the capture register 28. Then, after outputting the count value to the capture register 28, the value of the counter is cleared and counting is started again. That is, the counter 27 outputs the count value “B” when the signal d is input to the capture register 28 as shown in FIG. 7F, clears the counter value, starts counting again, and The count value “C” when the signal d is input is output to the capture register 28 again.

The capture register 28 latches the count value from the counter 27 and outputs the latched count value to the differentiator 31 as shown in FIG. The difference device 31 calculates the difference between the count value latched in the capture register 28 and the set value Z of the rotation speed set value 30, and calculates a difference value (A−A) as shown in FIG.
z, Bz, Cz, Dz) are sequentially output. Then, the difference value is converted into analog data by the D / A converter 32 and the spindle driver 1
7 is supplied. Therefore, a spindle drive signal obtained by amplifying the analog data is output from the spindle driver 17 to the spindle motor 6, and the spindle servo control is executed.

When the spindle drive signal for controlling the spindle motor 6 is generated by the clock mark formed on the wobbling groove of the disk D, the signal generated from the conventional spindle motor 6 is used as compared with the case where the signal obtained from the conventional spindle motor 6 is used. Since a spindle servo signal of about 16 to 24 times can be obtained, the sampling frequency as a servo operation becomes higher and the rotation accuracy of the spindle motor can be improved. Also, FG
Since there is no need to provide a detection mechanism such as a sensor, there is an advantage that the structure can be simplified and the structure can be reduced.

4. FIG. 8 shows the configuration of a spindle servo system according to a second embodiment. The same parts as those in FIG. 6 are denoted by the same reference numerals, and description thereof will be omitted.

The BPF 41 shown in this figure is a filter for extracting a wobble groove component of the push-pull signal PP and a frequency deviation due to FM modulation. FM demodulator 42 is B
The demodulator demodulates the signal extracted by the PF 41, the comparator 43 is a binarization circuit for binarizing the demodulated signal demodulated by the FM demodulator 42, and the sync detection circuit 44 is binarized by the comparator 43. This is a detection circuit that detects a sync pattern from a binary signal. The circuit blocks surrounded by broken lines are provided in the servo processor 14 in FIG.

Next, the operation of the spindle servo system shown in FIG. 8 will be described with reference to a timing chart shown in FIG. Also in this case, the two-axis mechanism and the thread mechanism provided in the pickup 1 are controlled by the servo circuit 34, so that the focus servo and the tracking servo of the disk D are applied.

The push-pull signal PP detected by the push-pull detection circuit 21 in the state where the focus servo and the tracking servo are applied is filtered by the BPF 41, and the wobble is FM-modulated as shown in FIG. A signal i obtained by extracting the groove component is output. This signal i is supplied to the FM demodulator 42,
Address data j modulated into a wobble groove as shown in FIG. 9 (j) is demodulated. The address data j is the 48-bit data shown in FIG.

This address data j is supplied to the comparator 43
, And is converted to binary data k as shown in FIG. When detecting the sync pattern from the binary data k, the sync detection circuit 44 outputs a sync detection signal 1 as shown in FIG. Then, the sync detection signal 1 is supplied to the counter 27 and the capture register 28.

The counter 27 has a sync detection signal 1 and a reference clock e from the oscillator 26 as shown in FIG.
Is supplied, the reference clock e is counted, and the count value when the sync detection signal 1 is input from the sync detection circuit 44 is output to the capture register 28. Then, after outputting the count value to the capture register 28, the value of the counter is cleared and counting is started again. That is, the counter 27 outputs the count value “F” when the sync detection signal 1 is input to the capture register 28 as shown in FIG. 9 (n), clears the counter value, and starts counting again. Then, the count value “G” when the next sync detection signal 1 is input is output to the capture register 28, and the count value is output to the capture register 28.

As shown in FIG. 9 (o), the count value from the counter 27 is latched in the capture register 28, and the latched count value is output to the differentiator 31. The difference device 31 calculates a difference between the count value latched in the capture register 28 and the set value Z of the rotation speed set value 30, and calculates a difference value (E−
z, Fz, Gz, Hz) are sequentially output. Then, the difference value is converted into analog data by the D / A converter 32 and the spindle driver 1
7 is supplied. Therefore, the spindle driver 17 outputs a spindle drive signal obtained by amplifying the analog data to the spindle motor 6 to execute the spindle servo control.

When the spindle servo signal for controlling the spindle motor 6 is generated by the sync pattern of the FM-modulated address data in the wobbling groove of the disk D, the signal obtained from the conventional spindle motor is used. Approximately 1.3 times
Since 2.6 times the rotation information can be obtained, the sampling frequency for the servo operation becomes higher and the rotation accuracy of the spindle motor can be improved. Also, since there is no need to provide a detection mechanism such as an FG sensor,
There is an advantage that the structure can be simplified and the structure can be formed at low cost.

5. Configuration and Operation of Spindle Servo System According to Third Embodiment FIG. 10 shows a configuration of a spindle servo system block according to the third embodiment. The same parts as those in FIG. 6 are denoted by the same reference numerals, and description thereof will be omitted.

The BPF 51 shown in this figure is a filter for extracting only the wobble groove carrier component of the push-pull signal PP, and the comparator 52 is a binarizing circuit for binarizing the signal extracted by the BPF 51. . The frequency divider 53 divides the frequency of the reference clock from the oscillator 26 to the same frequency as the wobble groove carrier component. The phase comparator 54 is a phase comparator that compares the phase of the clock divided by the frequency divider 53 with the phase of the binary signal binarized by the comparator 52. The circuit blocks surrounded by broken lines are provided in the servo processor 14 in FIG.

Next, the operation of the spindle servo system shown in FIG. 10 will be described with reference to a timing chart shown in FIG. Also in this case, the two-axis mechanism and the thread mechanism provided in the pickup 1 are controlled by the servo circuit 34, and the focus servo and the tracking servo of the disk D are applied.

The push-pull signal PP detected by the push-pull detection circuit 21 in the state where the focus servo and the tracking servo are applied is filtered by the BPF 51, and the carrier component of the wobble groove as shown in FIG. The signal q from which only the signal is extracted is output to the comparator 52. The comparator 52 binarizes the signal q and outputs a binarized signal r as shown in FIG.

The binary signal r and the phase comparator 54 shown in FIG.
A frequency-divided clock s divided by a frequency divider 53 as shown in (s) is supplied to compare the phase of the binary signal r with the frequency-divided clock s. (T)
Is output as shown in FIG. The phase comparison data t is converted into analog data as shown in FIG.
Supplied to Accordingly, a spindle drive signal obtained by amplifying the analog data is output from the spindle driver 17 to the spindle motor 6, and the spindle servo control is executed.

When the spindle servo signal for controlling the spindle motor 6 is generated by the carrier component of the wobbling groove of the disk D in this manner, it is about 480 to 720 times as compared with the case where the signal obtained from the conventional spindle motor is used. Because you can get twice the rotation information,
The sampling frequency as a servo operation becomes very high, which can greatly improve the rotational accuracy of the spindle motor. Further, since there is no need to provide a detection mechanism such as an FG sensor, there is an advantage that the structure can be simplified and the structure can be reduced.

[0062]

As described above, in the disk drive device of the present invention, the rotation error information of the rotation drive means is obtained from various information formed in the wobbling groove area of the disk-shaped recording medium. A large number of samples of rotation error information can be obtained, and the rotation accuracy of the rotation drive unit can be improved. In addition, since rotation error information can be obtained from various types of information formed on the disk-shaped recording medium, stable rotation servo control can be performed without being affected by eccentricity, surface shake, and the like of the disk-shaped recording medium. Furthermore, there is an advantage that the configuration can be made at a lower cost than when the FG sensor is attached to the rotation driving means.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a structure of a wobbling groove formed on a disk.

FIG. 2 is a diagram showing a format of wobble data of a wobbling groove.

FIG. 3 is a diagram showing a format of wobble data in units of 48 bits expressed by wobbling groove FM modulation.

FIG. 4 is a diagram showing a main part of a reproduction system and a servo block of the disk drive device of the present embodiment.

FIG. 5 is a diagram showing a configuration of a detector 5;

FIG. 6 is a diagram showing a configuration of a spindle servo system according to the first embodiment.

FIG. 7 is a timing chart illustrating an operation of the spindle servo system according to the first embodiment;

FIG. 8 is a diagram showing a configuration of a spindle servo system according to a second embodiment.

FIG. 9 is a timing chart illustrating an operation of a spindle servo system according to a second embodiment.

FIG. 10 is a diagram showing a configuration of a spindle servo system according to a third embodiment.

FIG. 11 is a timing chart illustrating an operation of a spindle servo system according to a third embodiment;

[Explanation of symbols]

1. Pickup, 2. Objective lens, 3. Biaxial mechanism, 4.
Laser diode, 5 detector, 6 spindle motor, 7 turntable, 8 thread mechanism, 9
RF amplifier, 10 system controller, 11 binarization circuit, 12 decoder, 13 interface, 14
Servo processor, 15 thread driver, 16 two-axis driver, 17 spindle driver, 18 laser driver, 21 push-pull detection circuit, 22 41
51 BPF, 23 Window generator, 24
Zero cross detector, 25 AND circuit, 26 oscillator, 27 counter, 28 capture register, 29
CPU, 30 rotation number setting circuit, 31 difference device, 32
D / A converter, 33 LPF, 42 FM demodulator, 43 52 comparator, 44 sync detection circuit, 53 divider, 54 phase comparator

Claims (5)

[Claims] 1. A method according to claim 1, wherein predetermined control information is modulated by a predetermined method and further recorded or recorded on a disk-shaped recording medium having a wobbled groove area based on a signal to which a specific mark signal is added at regular intervals. As a disk drive device that performs a reproducing operation, a rotation driving unit that rotationally drives the disk-shaped recording medium, and extracts a specific mark signal included at a predetermined interval in a read signal according to wobbling of a groove area of the disk-shaped recording medium, Mark detection means for outputting a timing signal corresponding to the mark signal; target count value setting means for setting a target count value corresponding to a target rotation speed of the rotation drive means; and a count value obtained by counting the cycle of the timing signal. And rotation error information output means for outputting a difference value between the target count value and the target count value as rotation error information. The disk drive apparatus characterized by comprising a rotation control means for controlling the rotational speed of the rotary drive means on the basis of the rotation error information. 2. The apparatus according to claim 1, wherein the mark detecting means detects a clock mark signal added for clock reproduction as a specific mark signal included at a predetermined interval in the read signal. Disk drive device. 3. A disk-shaped recording medium having a groove area in which control information units having a predetermined data length are continuously formed with control information, and the control information is wobbled based on a signal modulated by a predetermined method. A disk drive device that performs a recording or reproducing operation on the disk drive, a rotation driving unit that rotates the disk-shaped recording medium, and a read timing of each control information unit from a read signal corresponding to wobbling of a groove area of the disk-shaped recording medium. An information unit detection unit that outputs a timing signal that becomes a target count value setting unit that sets a target count value corresponding to a target rotation speed of the rotation driving unit; a count value obtained by counting a cycle of the timing signal; Rotation error information output means for outputting a difference value from a target count value as rotation error information; Disk drive apparatus characterized by comprising a rotation control means for controlling the rotational speed of the rotary drive means on the basis of the information. 4. The information unit detecting means detects a synchronization pattern added to each information unit as a timing signal of each control information unit.
A disk drive device according to claim 1. 5. A disk drive device for performing a recording or reproducing operation on a disk-shaped recording medium having a groove area wobbled based on a signal obtained by modulating predetermined control information at a predetermined carrier frequency. Rotation driving means for driving a recording medium to rotate; wobble carrier extraction means for extracting a wobbling carrier frequency in a groove area of a disc-shaped recording medium; and target frequency for setting a target frequency corresponding to a target rotation value of the rotation driving means. Setting means, rotation error information output means for outputting rotation error information as a comparison result of the carrier frequency and the target frequency, rotation control means for controlling the rotation speed of the rotation driving means based on the rotation error information, A disk drive device comprising: