KR19990012357A - Servo control method and apparatus for disc reproducing apparatus - Google Patents

Abstract

The present invention relates to a servo control method and apparatus for a disc reproducing apparatus, and more particularly, to detect and store an error amount due to disc and deck assembly for a plurality of tracks during initial disc loading, and to control a value corresponding to the error amount during reproduction. It is an object of the present invention to stabilize the reproducing operation and to improve the reproducing ability by inputting and compensating the circuit. The present invention for this purpose is a tracking error (TE) and focusing in the output signal of the PG / FG detection unit 207 and the pickup 202 for detecting the frequency (FG) and phase (PG) generated in each revolution of the spindle motor The high frequency amplifier 203 detects an error FE, and the PG / FG detection unit 207 of the tracking error TE and focusing error FE from the high frequency amplifier 203 during the disc reproducing operation. The servo control unit 205 predicts and controls the tracking and focusing of the pickup 201 by compensating for the tracking error amount and the focusing error amount stored on the basis of the frequency detection pulse FG, and data transmission / reception with the servo control unit 205. The microcomputer 206 stores the focusing error amount and tracking error amount during initial loading of the disc and outputs the stored focusing error amount and tracking error amount to the servo controller 205 during the disc reproduction operation.

Description

Servo control method and apparatus for disc reproducing apparatus

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc reproducing apparatus, and more particularly, to a servo control method and apparatus for a disc reproducing apparatus, which is adapted to optimally control tracking and focusing during reproduction.

FIG. 1 is a block diagram of a conventional disc reproducing apparatus, as shown therein, for a pickup 102 detecting information recorded on an optical disc 101, and a tracking error (amplifying an output signal of the pickup 102). A high frequency amplifier 103 for detecting TE) and a focusing error FE, and a digital signal processor 104 for receiving digital output signals of the high frequency amplifier 103 and performing digital signal processing such as error correction to output digital data. ), A servo controller 105 which receives the tracking error (TE) and the focusing error (FE) from the high frequency amplifier 103 and controls tracking and focusing of the pickup 102, and the digital signal processor 104. ) And a microcomputer 106 for outputting a driving control signal to the servo controller 105 while performing data transmission / reception.

Referring to the operation of the conventional device as follows.

When the regeneration mode is set, the servo controller 105 controls the tracking and focusing of the pickup 102, and the pickup 102 detects the data recorded on the disc 101.

At this time, the high frequency amplifier 103 amplifies the reproduction signal from the pickup 102 and outputs it to the digital signal processing unit 104, and simultaneously detects the tracking error (TE) and the focusing error (FE) and outputs it to the servo controller 105. Done.

Accordingly, the servo control unit 105 corrects the tracking and focusing of the pickup 102 in response to the tracking error TE and the focusing error FE from the high frequency amplifier 103 so that the pickup 102 can detect the disc 101. The recording data can be stably detected.

However, such a conventional technique has a deflection amount of a disc generated during or during use of a disc, a focusing error caused by deck assembly (flatness of a spindle motor, etc.), and a tracking error amount due to bending of a pit row generated during a disc production. There is a problem that an abnormal regeneration or a non-regeneration state may occur due to the size of.

In particular, the error by the amount of warpage of the disk is more likely to occur.

This is a block for processing phase / frequency (PG / FG) signals in the phase / frequency (PG / FG) detection circuit and servo control circuit without the sensors (PG, FG) attached to the spindle motor to detect phase and frequency. This is because even if the error amount of the disk and spindle motor flatness, which can have a very serious effect on the regeneration operation, can not be compensated for.

Therefore, in order to improve the conventional problem, the present invention detects, stores, and reproduces an error amount due to disc and deck assembly for a predetermined section of a plurality of discrete tracks during initial loading of an error. It is an object of the present invention to provide a servo control method and apparatus for a disc reproducing apparatus, which is designed to stabilize a reproducing operation and to improve reproducing ability by inputting and compensating a value corresponding to the servo control circuit.

The present invention for this purpose is to prevent as much as possible from normal playback, including the amount of focusing and tracking errors that occur during disc production, deck assembly or disc playback.

The present invention can improve the quality of the product by improving the playback ability for various types of disc compared to other products.

That is, the present invention detects the focusing error and the tracking error amount in a predetermined section of a plurality of discrete tracks from the inner circumference to the outer circumference of the disc and stores them in synchronization with an arbitrary reference signal in the predetermined period of the disc before the normal playback. Focusing error and tracking error during driving take the tracking / focusing error data stored in synchronization with the arbitrary reference signal to perform predictive control so that the focusing and tracking drive actuator can be operated quickly so that abnormal playback or playback is impossible. The purpose is to resolve the condition as much as possible.

1 is a block diagram of the prior art;

2 is a block diagram according to the present invention;

3 is a block diagram showing a specific embodiment of FIG.

4 is an operational waveform diagram of FIG. 3.

5 is an exemplary view showing a correlation between a detection pulse and an error amount in the present invention.

6 is a signal flow diagram for a storage operation in the present invention.

7 is a signal flowchart for servo control in the present invention.

Explanation of symbols on the main parts of the drawings

201: disc 202: pickup

203: high frequency amplifier 204: digital signal processing unit

205: servo control unit 206: microcomputer

The present invention provides a pickup for detecting information recorded on an optical disc, a high frequency amplifier for amplifying an output signal of the pickup and detecting a tracking error and a focusing error, and an output signal of the high frequency amplifier. Digital signal processing unit for performing digital signal processing such as error correction and outputting digital data, and compensating tracking error and focusing error from the high-frequency amplifier during reproducing operation with the amount of tracking error and focusing error stored at the time of initial loading. A servo controller for resetting the tracking and focusing gain of the pickup, a PG / FG detector for outputting a frequency detection pulse and a phase detection pulse according to driving of the pickup to the servo controller, and data transmission / reception with the digital signal processor and servo controller To focusing during initial disc loading Storing the tracking error amount and the amount, based on the frequency detection pulse and is characterized in that the configuration of the focusing error and the tracking error amount of the amount stored in the event of a disk playback system controller for output to the servo control section.

In addition, the present invention to determine the initial loading or playback of the disc in order to achieve the above object, in the case of the initial loading of the disc, the step of dividing the entire track into a predetermined track amount, and the corresponding track divided Detecting and storing the tracking error and the focusing error of the signal, determining the playback position from the phase detection pulse in the case of the playback, and calculating a predicted control amount from the pre-stored tracking and focusing errors of the determined position. And resetting the tracking and focusing gain by adding the predicted control amount to the control amount due to the current tracking and focusing error.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 2 is a block diagram of the present invention, as shown therein, of a pickup 202 for detecting information recorded on an optical disc 201, and a spindle motor (not shown) in accordance with driving of the pickup 202. As shown in FIG. PG / FG detection unit 207 for detecting frequency pulses (FG) and phase pulses (PG) generated at each rotation, and amplifying the output signal of the pickup (202), while tracking error (TE) and focusing error (FE) ), A digital signal processing unit 204 for receiving digital signal processing such as error correction by receiving the output signal of the high frequency amplifier 203 and outputting digital data; The tracking error (TE) and the focusing error (FE) from the high frequency amplifier 203 are compensated by the tracking error amount and the focusing error amount stored on the basis of the frequency detection pulse FG of the PG / FG detector 207 during initial loading. And tracking of the pickup 201 Saves the focusing error amount and tracking error amount during initial disk loading while performing data transmission / reception with the servo control unit 205 and the digital signal processing unit 204 and the servo control unit 205. The microcomputer 206 outputs the stored focusing error amount and tracking error amount to the servo control unit 205.

Referring to the operation and effect of the present invention configured as described above are as follows.

When the disc is initially loaded onto the deck, if the pickup 202 detects the data recorded on the disc 201, the high frequency amplifier 203 detects the tracking error (TE) and the focusing error (FE) and sends it to the servo control unit 205. The digital signal processing unit 204 receives the output signal of the high frequency amplifier 203 and transmits the track position information or the disc time information recorded on the disc 201 to the microcomputer 206.

At this time, the microcomputer 206 outputs a drive control signal to the servo control unit 205 to detect the tracking error (TE) and the focusing error (FE) for each track by dividing the entire track of the disc 201 by a predetermined value. do.

Accordingly, the servo controller 205 drives the pickup 202 and the tracking error TE and focusing error FE detected by the high frequency amplifier 203 and the frequency detection pulse detected by the PG / FG detector 207. FG) and the phase detection pulse PG are output to the microcomputer 206.

Therefore, the microcomputer 206 receives the focusing error FE and the tracking error TE from the high frequency amplifier 203 and receives the error amount between each rotation by the frequency detection pulse FG of the PG / FG detector 207. Will be stored in synchronization with the sequence number).

Subsequently, when the regeneration operation is started, the servo control unit 205 starts the tens to hundreds of frequency detection pulses FG and one phase detection pulse PG generated during one rotation of the disk 201 from the FG / PG detection unit 207. ) Determines the playback track position of the disc 201, receives the focusing error (FE) and the tracking error (TE) input from the high frequency amplifier 203, calculates the gain, and simultaneously obtains the gain from the microcomputer 206. A tracking error amount and a tracking error amount corresponding to the track position determined in step s are input to predict the tracking and focusing gain for the next track.

Accordingly, the servo control unit 205 adds the control amount calculated from the high frequency amplifier 203 as the input of the tracking error TE and the focusing error FE, and the estimated tracking and focusing control amounts, respectively, to track the pickup 202. And by controlling the focusing gain, the pickup 202 performs stable playback operation by detecting recorded data while accurately estimating the corresponding track on the disc 201, so that the playback characteristics are good.

3 is a block diagram showing a specific embodiment of the present invention, as shown therein, a spindle motor 341 for driving the disk 301 and a spindle motor driving circuit for driving the spindle motor 341. 310, a sled motor 344 for moving the pickup 302 to the inner circumference or the outer circumference, a sled motor driving circuit 330 for driving the sled motor 344, and the pickup 302 A tracking drive actuator 342 and a focusing drive actuator 343 for adjusting tracking and focusing, a tracking / focusing drive circuit 320 for driving the tracking drive actuator 342 and a focusing drive actuator 343, and the pickup A high frequency amplifier 303 which amplifies the optical signal at 302 and detects a tracking error TE and a focusing error FE and a high frequency output signal RF of the high frequency amplifier 303 are synchronized with each other. In addition to separating the signal (SYNC) A data slicer 309 that is divided into blocks and the output data of the data slicer 309 are input to perform digital signal processing, such as error correction, to output track position information and disk time information, and to output digital data. A digital signal processor 304, a PG / FG detector 307 for detecting a frequency detection pulse FG and a phase detection pulse PG according to the drive of the spindle motor 341, and the high frequency amplifier during a regeneration operation. The tracking error (TE) and the focusing error (FE) from 303 are compensated by the tracking error amount and the focusing error amount stored on the basis of the frequency detection pulse FG of the PG / FG detector 307 at the time of initial loading. The tracking / focusing driving circuit 320 for resetting the tracking and focusing gain signal of the pickup 301, a signal for driving the spindle motor 341, and a signal for driving the sled motor 344. During initial disk loading while performing data transmission / reception with the servo control unit 305 and the digital signal processing unit 304 and the servo control unit 305 respectively outputting to the spindle motor driving circuit 310 and the sled motor driving circuit 330. A microcomputer that stores the focusing error amount and the tracking error amount of the controller and outputs the focusing error amount and the tracking error amount during playback, and the drive control signals of the spindle motor 341 and the sled motor 344 to the servo controller 305. It consists of 306.

When described in detail the operation and effect of the embodiment of the present invention configured as described above.

When the disk 301 is mounted on the deck, the pickup 302 detects the data recorded on the disk 301 and the high frequency amplifier 303 causes the pickup 302 to detect a tracking error (TE) and a focusing error (FE). The data slicer 309 receives the output signal of the high frequency amplifier 303, detects the synchronization signal SYNC, and outputs the same to the servo controller 305. Will be separated.

The digital signal processor 304 receives the output signal of the data slicer 309 and transmits the track position information or the disc time information recorded on the disk 301 to the microcomputer 306.

At this time, the microcomputer 306 outputs a drive control signal to the servo control unit 305 to detect the tracking error (TE) and the focusing error (FE) for each track by dividing the entire track of the disc 301 by a predetermined value. do.

Accordingly, the servo controller 305 converts the spindle motor drive control signal and the sled motor drive control signal from the microcomputer 306 to drive the spindle motor 341 and the sled motor 344 respectively. The tracking / focusing driving control signal, which is analog converted, is output to the furnace 310 and the sled motor driving circuit 330, respectively, and outputs to the tracking / focusing driving circuit 320 to track and focus the pickup 302. The tracking drive actuator 342 and the focusing drive actuator 343 for adjustment are driven.

At this time, the servo controller 305 digitally converts the tracking error (TE) and the focusing error (FE) detected by the high frequency amplifier 303 and outputs them to the microcomputer 306 and at the PG / FG detection unit 307. The detected frequency detection pulse FG and the phase detection pulse PG are output to the microcomputer 306.

Accordingly, the microcomputer 306 receives the digitally converted signal of the focusing error FE and the tracking error TE in the high frequency amplifier 303 and receives the error amount between each rotation of the PG / FG detector 307. The data is stored in synchronization with the order of the frequency detection pulse FG.

That is, the microcomputer 306 is made up of the components of Fig. 4 (c) (d) detected from the disk 301 in synchronization with the frequency detection pulse FG as shown in Fig. 4 (b) while the spindle motor 341 is rotated once. The same tracking error amount and focusing error amount are stored.

If the error amount of each rotation of the stored spindle motor 341 is kept below the reference value, the microcomputer 306 generates a new error amount by calculating a correlation according to the error amount of the adjacent tracks. Is stored by updating the error amount of the corresponding track, and storing only one of the two data when the detected error amount is similar to the error amount of the adjacent track.

If the error amount is taken for only a predetermined number of tracks without taking the error amount of all tracks of the disc 301, the time taken for the initial error data amount and the storage capacity are reduced.

This is because the tracks formed on the disc 301 correlate with the error amounts between adjacent tracks.

That is, when the entire track is divided from the inner circumference to the outer circumference at predetermined intervals, as shown in the exemplary diagram of FIG. 5, the frequency detection pulse FG and the phase detection pulse PG generated during one rotation of the spindle motor 341. This is because the errors detected in each track with respect to each other are correlated with each other.

The above operation is performed in the same process as the signal flow of FIG.

After that, when the regeneration operation is set by the key input unit 308 and the microcomputer 306 outputs a driving control signal to the servo control unit 305, the servo control unit 305 is the spindle motor drive circuit 310, tracking / focusing. The drive circuit 320 and the sled motor drive circuit 340 are controlled to rotate the disk 301 by the spindle motor 341 to pick up 302 by the tracking drive actuator 342 and the focusing drive actuator 343. Tracking and focusing adjustment and the movement of the pickup 302 by the sled motor 344 to start the playback operation.

At this time, the PG / FG detector 307 detects a frequency and phase change caused by the rotation of the spindle motor 341, and the high frequency amplifier 303 amplifies the signal detected by the pickup 302 on the disk 301. In addition, the tracking error (TE) and the focusing error (FE) are detected and the data slicer 309 separates the sync signal SYNC from the high frequency amplified signal RF of the high frequency amplifier 303, and in units of sync blocks. Will be separated.

Accordingly, the digital data processing unit 304 receives the output signal separated in units of blocks in the data slicer 309, extracts the track position information or the disc time information recorded on the disc 301, and sends the same to the microcomputer 306. The microcomputer 306 outputs a tracking and focusing error amount corresponding to the current track among the error amounts stored at the initial loading of the disk 301 and drive control for the spindle motor 341 and the sled motor 344. The signal is output to the servo controller 305.

At this time, the servo controller 305 receives from the FG / PG detection unit 307 a disk of several tens to hundreds of frequency detection pulses (FG) and one phase detection pulse (PG) generated during one revolution of the spindle motor 341. Determining the playback track position of the 301 and receiving the focusing error (FE) and the tracking error (TE) input from the high frequency amplifier 203 and at the same time, the previously stored track position corresponding to the track position determined above from the microcomputer 206 is received. The amount of focusing error and tracking error is input to predict a gain for tracking and focusing control for the next track.

That is, the servo controller 305 generates the tracking control amount and the focusing control amount as shown in FIG. 4 (f) (h) by inputting the tracking error TE and the focusing error FE of the high frequency amplifier 303, and the microcomputer. The prediction tracking control amount and the prediction focusing control amount as shown in FIG. 4 (e) (g) are generated by inputting the tracking error and the focusing error as shown in FIG. 4 (c) (d) stored at 306 to FIG. a gain value for tracking control is synthesized by synthesizing the control amount of f), and a gain value for focusing control is generated by synthesizing the control amount of FIG. To 320).

Here, the predicted gain value is output before the existing tracking / focusing loop for a predetermined time.

Accordingly, the servo controller 305 analog converts the drive control signal from the microprocessor 306 to drive the spindle motor drive circuit 310 and the sled motor drive circuit based on the synchronization signal SYNC in the data slicer 309. Each output to the furnace 330 and the analog to the gain value for tracking and focusing control to output to the tracking / focusing driving circuit (320).

At this time, when the low pass filter 311 passes only a predetermined low-pass component of the spindle motor driving signal from the servo controller 305, the spindle motor driving circuit 310 receives the input through the buffer 312. When the disk 301 is rotated by driving the spindle motor 341, and the sled motor driving circuit 330 passes only a predetermined low-pass component of the sled motor driving signal from the servo controller 305, the low-pass filter 331 passes. The sled motor driver 333 received through the buffer 332 drives the sled motor 344 to move the pickup 302 from the inner circumference to the outer circumference or from the outer circumference to the inner circumference.

The tracking / focusing driving circuit 320 generates a buffer 322 and 324 when the low pass filters 321 and 323 pass driving signals for tracking and focusing in the microcomputer 306, respectively, only a predetermined low pass component. The tracking / focusing drive unit 325 received through the control unit drives the tracking drive actuator 342 and the focusing drive actuator 343 to control the tracking and focusing operation of the pickup 302.

Therefore, under the control of the servo control unit 305, the pickup 302 accurately detects the recording data while accurately estimating the corresponding track on the disc 301, thereby performing a stable reproducing operation, thereby improving the reproduction characteristics.

The above process for servo control is performed in the same manner as the signal flow of FIG.

As described in detail above, the present invention stores the tracking and focusing error amounts for any track during initial disc loading, and then compensates for the tracking and focusing errors for the current track position during playback with the stored tracking and focusing error amounts. By predicting the control amount for the track, it is possible to improve the reproduction ability and at the same time improve the reliability of the product.

In particular, the DVD has a smaller track pitch and a smaller focusing and tracking error margin than the conventional CD-DA, video CD, CD-ROM, etc., but the present invention can be applied.

Claims (8)

A first step of detecting a signal generated according to motor rotation in at least one discrete track, a second step of detecting an amount of servo signal error generated in synchronization with the detected signal, and the servo signal detected above And a fourth step of storing an error amount and a fourth step of outputting a control signal according to the stored servo signal error amount at the synchronization point of time. The servo control method of claim 1, wherein the signal generated according to the rotation of the motor is a frequency (FG) and a phase (PG) signal generated at each rotation of the motor. The method of claim 1, wherein the detected servo error signal is a tracking and focusing error signal. A first step of detecting a signal generated according to motor rotation in at least one discrete track, a second step of detecting an amount of servo signal error generated in synchronization with the detected signal, and the servo signal detected above And a fourth step of storing an error amount and a fourth step of outputting a control signal according to the stored servo signal error amount in advance of the servo gain change point divided by the discrete tracks. Servo control method. A first step of detecting an amount of servo signal error generated in at least one discrete track; a second step of storing the detected servo signal error amount; and a servo gain change point divided by the discrete track. And a third step of outputting a control signal according to the stored amount of the servo signal error. The disk reproducing apparatus according to claim 1, wherein the third step of storing the servo signal error amount compares the stored servo error amounts and stores only one of two compared error amounts when the similar servo error amounts are similar. Servo control method. Servo gain change start point detecting means for detecting a signal generated by the rotation of the motor in at least one discrete track, storage means for storing the amount of servo signal error generated in synchronization with the detected signal, and in the discrete track And control means for outputting a control signal in accordance with the stored servo signal error amount prior to the servo gain change point divided by section. 8. The servo control apparatus of claim 7, wherein the control means outputs a control signal corresponding to the stored servo signal error amount at a servo gain change point divided by a discrete track.