KR20040082746A - Apparatus for optical disc record/playback and methode at the same - Google Patents

Abstract

The present invention relates to an optical disc recording and reproducing apparatus and method, wherein the optical disc recording and reproducing method comprises the steps of: extracting a wobble from a surface of an optical disc; determining the speed of recording and reproducing the optical disc; Controlling a phase-locked loop by using a wobble signal when the reproduction is low speed, controlling a phase-locked loop by using a phase inversion section signal when the optical disk is high-speed, and controlling generated from the phase-locked loop. Since the rotation of the spindle is controlled by the voltage, stable recording and reproducing can be performed according to the double speed.

Description

Apparatus for optical disc record / playback and methode at the same}

The present invention relates to an optical disc recording and reproducing apparatus and method, and more particularly, to an optical disc recording and reproducing apparatus and method capable of easily controlling the rotation of a spindle in accordance with double speed.

Generally, recordable optical discs such as DVD-RAM (Digital Versatile Disc-RAM) are provided with concentric or spiral tracks (groove tracks / land tracks). User data is recorded in the track. The method of recording information on the optical disc includes the constant linear velocity (CLV) method of recording information at a constant bit rate as the rotational speed of the optical disc changes according to the position of the track, and at the innermost circumference regardless of the position of the track. The Constant Angle Velocity (CAV) method, which records information at a constant bit rate while maintaining a constant rotation speed to the outermost circumference, is widely known.

Such a rewritable optical disc (for example, a DVD-RAM) records a lead-in area, a lead-out area, and actual data as shown in FIG. The data area is divided into zones, and the data area is divided into zones and managed.

At this time, in order to record / read user data using the optical pickup apparatus, the pickup apparatus should be able to move freely to a desired position. For this purpose, the addressing information is recorded on the optical disc 10. Here, the "addressing information" refers to "identification information given to each unit recording block when the track is divided into a plurality of unit recording blocks". The unit recording block of the DVD-RAM is a sector and the unit recording block of the DVD-RW is one ECC (Error Correction Code) block.

Therefore, such a conventional optical disk can record address information by wobbling in response to the addressing information.

Fig. 2 is a partial plan view of a conventional optical disc, in which a track 11 (land track and / or groove track), which is a user data area, is formed. The wobble signal 12 is recorded in the track 11 by using the change in the amplitude direction.

Here, the wobble signal 12 is used as a means for obtaining a recording clock signal or a reproduction clock signal during recording / reproducing. Although not shown, a predetermined area of each sector is provided with a header area in which header information is recorded as pre-pits. The pickup device provided in the recording / playback apparatus can be easily moved to a desired position through the addressing information recorded in the header area. In addition, the sector number, sector type, information track, and the like can be recognized, and servo control can be performed.

Fig. 3 is a diagram showing the structure of address information recorded corresponding to the recording / reproducing cluster of the optical disc, in which one address information indicates a sink (SYNC) 13 portion representing a synchronization signal, an address data and its error correction code, respectively. The data 14 to be shown is divided into parts.

Here, the address information is formed on the optical disc as 93 wobbles (93 wobbles), which is divided into eight phase shift sections and 85 cycle monotone sections, as shown in FIG.

5 is a general block diagram of an optical disk recording / reproducing apparatus for recording and reproducing data on a conventional optical disk, wherein the optical pickup 15 is focused on an objective lens under the control of the servo control unit 16. The light beam is placed on the signal track of the optical disc 10 (11 in FIG. 2), and the light reflected from the signal recording surface is again focused by the objective lens and then incident on the photo detector for detection of the focus error signal and the tracking error signal. do.

The photodetector is composed of a plurality of photodetectors, wherein an electrical signal proportional to the amount of light obtained by each photodetector is sent to the focus error signal detector 17, the tracking error signal detector 18, and the data processor 19. Are output respectively.

The focus error signal detector 17 detects a focus error signal FE from the electrical signal output from the photo detector and outputs it to the servo controller 16, and the tracking error signal detector 18 is output from the photo detector. The tracking error signal TE is detected from the electrical signal and output to the servo controller 16.

The servo controller 16 processes the focus error signal FE to output a driving signal for focusing control to the focus servo driver 20, and processes the tracking error signal TE to drive the signal for tracking control. Is output to the tracking servo driver 21.

At this time, the focus servo driver 20 moves the optical pickup 15 up and down by driving the focus actuator in the optical pickup 15 so that the optical disk 10 follows the vertical movement along with the rotation. That is, the focus actuator for driving the objective lens to focus up and down, that is, in the focus axis direction, keeps the distance between the objective lens and the optical disc 10 constant according to the focus control signal.

In addition, the tracking servo driver 21 drives the tracking actuator in the optical pickup 15 to move the objective lens of the optical pickup 15 in a radial direction to correct the position of the beam and track a predetermined track. do. That is, it controls so that the optical pickup 15 and the track 11 center line of the disc 301 may match.

The data processor 19 detects a radio frequency (RF) signal from the electrical signal output from the photo detector and outputs the radio frequency (RF) signal to the servo controller 16, and the servo controller 16 outputs a disc from the RF signal. Information about the rotational speed is output to the spindle servo 22. The spindle servo 22 rotates the optical disc 10 by controlling a phase locked loop (PLL) of the spindle motor 23 according to the rotation speed information. That is, the spindle motor 23 gives a rotational force to the spindle for the rotation of the disk 301, the spindle transmits the rotational force given by the spindle motor 23 to the optical disk 10 to rotate the optical disk 10 at a desired speed. .

However, the prior art optical disc recording and reproducing apparatus has the following problems.

The conventional optical disc recording and reproducing apparatus extracts the wobble signal output from the optical disc and controls the spindle by using a difference from the reference clock in the data processing unit, so that an optical disc having a high frequency of the wobble signal can be used for high speed recording and playback. The signal-to-noise ratio worsened, the spindle was not easy to control.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides an optical disc recording and reproducing apparatus and method for extracting a wobble signal at low speed, extracting a period of a phase inversion section at high speed, and increasing signal-to-noise ratio to facilitate reproduction and recording. Its purpose is to.

1 is a view showing the structure of a typical optical disk

2 is a partial plan view of a conventional optical disc.

3 is a diagram showing a structure of address information recorded corresponding to a recording / reproducing cluster of an optical disc;

4 is a diagram illustrating a wobble signal in a phase inversion section and a monotone section in a conventional optical disc.

Fig. 5 is a general block diagram of an optical disc recording / reproducing apparatus for recording and reproducing data on a conventional optical disc.

6 is a schematic cross-sectional view of a data processing unit and a servo control unit of the optical disc recording and reproducing apparatus according to the present invention.

Fig. 7 is a flowchart for explaining the optical disc recording and reproducing method of the present invention.

Explanation of symbols for main parts of the drawings

30: band filter 31: phase inversion section detection unit

32: phase inversion section correction unit 33: slicer

34: Wobble counter 35: Phase locked loop

36: phase / speed error generator

The optical disc recording and reproducing apparatus of the present invention for achieving the above object includes an optical pickup and an optical detector, a focus error signal detector, a tracking error signal detector, a data processor, a servo controller, a focus servo driver, a tracking servo driver and a spindle. In the optical disc recording and reproducing apparatus comprising a servo, the data processing section and the servo control section include a band filter for passing a wobble detection signal of the frequency band detected by the photodetector and a phase inversion section from the wobble detection signal output from the band filter. A phase inversion section detector for detecting a period of a phase and outputting a phase inversion section signal, a slicer for reducing the amplitude of the wobble detection signal to output a wobble signal, and receiving the phase inversion section signal and the wobble signal and having an arbitrary frequency; Phase synchronization to generate and output phase / speed signals And an error generator for detecting an error using the phase / speed signal and generating a normalized spindle rotation voltage to output the spindle servo voltage.

In the optical disc recording and reproducing apparatus and method of the present invention, recording and reproduction can be performed using a wobble signal when the optical disc is low speed, but it is difficult to extract the wobble signal normally at high speed, so that a lot of noise occurs in the wobble signal. Therefore, high-speed recording and reproducing can be made stable by using a period of a phase inversion section using a plurality of wobble signals.

Hereinafter, the optical disc recording and reproducing apparatus and method of the present invention will be described.

The optical disc recording and reproducing apparatus of the present invention includes an optical pickup and optical detector for directly recording and reproducing data on an optical disk, a focus error signal detector for outputting the surface state and data of the optical disk using an electrical signal output from the optical detector, and tracking. An error signal detector and a data processor, a servo controller for generating a control signal using various data of each detector and the data processor, a focus servo driver, a tracking servo driver, and a spindle controlled by a control signal output from the servo controller. Including servo.

The data processor extracts a wobble signal from the light detector and outputs the wobble signal to the servo controller, and the servo controller controls the spindle servo to rotate the optical disc according to a specific frequency output from the wobble signal.

In particular, the optical disc recording / reproducing apparatus of the present invention controls the spindle servo by using the period of the phase inversion period because the wobble signal is not stable in response to the wobble signal appearing at high speed.

That is, the wobble signal can be extracted normally at low speed, but the wobble signal is not stable at high speed, and thus has noise. Therefore, it is possible to control the rotation of the spindle by using the period of the phase inversion period among the address information represented by the wobble signal for a certain period.

Therefore, the optical disk recording and reproducing apparatus of the present invention can control the spindle by using the wobble signal at low speed, and control the rotation of the spindle by using the period of the phase inversion section at high speed.

6 is a schematic cross-sectional view of a data processing unit and a servo control unit of the optical disc recording and reproducing apparatus according to the present invention.

As shown in Fig. 6, the optical disc recording / reproducing apparatus of the present invention includes a band filter 30 that passes through a wobble detection signal of a corresponding frequency band extracted from the wobble, and a wobble detection signal output from the band filter 30. A phase inversion section detection unit 31 for detecting a period of the phase inversion section from the phase inversion section detection section 31 and a phase inversion section correction section 32 for correcting the phase inversion section signal outputted from the phase inversion section detection section 31; ), A slicer 33 for reducing the amplitude of the wobble detection signal and outputting a wobble signal, and a period of the wobble signal output from the slicer 33 is output to the phase inversion interval corrector 32. A phase locked loop (PLL) 35 that receives the phase inversion section signal and the wobble signal, and generates and outputs a phase / speed signal having an arbitrary frequency; Is configured to include a phase / speed error generator 36 for generating a spindle rotation voltage shaping finds the error by using the phase / speed signal.

Here, the phase inversion section detection unit 31 counts the wobble detection signal by a predetermined section and divides the phase inversion section into a monotone section to detect and output a period of the phase inversion section.

In addition, the phase inversion section detecting unit 31 outputs from the slicer 33 so that the phase inversion section correcting unit 32 can accurately grasp the period of the wobble signal in order to accurately grasp the period of the phase inversion section output from the phase inversion section detecting unit 31. The wobble signal may be used.

The phase synchronization loop 35 includes a phase comparator, a low pass filter, an error amplifier, and a voltage controlled oscillator, and outputs from the phase inversion section detector 31, the phase inversion section corrector 32, and the slicer 33. The phase inversion section signal and the wobble signal may be used to generate a phase / speed signal having an arbitrary frequency.

Therefore, the optical disc recording and reproducing apparatus of the present invention can generate a phase inversion signal because the signal-to-noise ratio of the wobble signal increases at high speed, thereby facilitating the rotation of the spindle even at high speed. Can be used to control the rotation of the spindle.

A driving method of the optical disc recording and reproducing apparatus of the present invention configured as described above will be described below.

7 is a flowchart for explaining the optical disc recording and reproducing method of the present invention.

As shown in Fig. 7, the optical disc recording and reproducing method of the present invention extracts a wobble by irradiating light onto the surface of the optical disc using an optical pickup and a photodetector (10S), and recording and reproducing the optical disc at double speed. It is determined according to (20S).

At this time, when recording and reproducing of the optical disc are performed at a low speed, the phase synchronization loop 35 is controlled using the wobble signal (30S).

On the other hand, when recording and reproducing of the optical disc are performed at high speed, the phase synchronization loop 35 is controlled by using a phase inversion period signal (phase inversion period period) generated by the wobble signal (40S).

Finally, by controlling the rotation of the spindle (50S) by the control voltage generated from the phase synchronization loop 35, stable recording and reproducing can be achieved according to the double speed.

Therefore, the optical disk recording and reproducing method of the present invention can perform stable recording and reproducing because the rotation of the spindle can be effectively controlled by using the wobble signal and the phase inversion section signal at low and high speeds, respectively.

As described above, the optical disc recording and reproducing apparatus and method according to the present invention have the following effects.

The optical disk recording and reproducing apparatus and method of the present invention can control the rotation voltage of the spindle by using a wobble signal and a phase inversion section signal at low and high speeds, respectively, so that stable recording and reproducing can be performed according to the double speed.

Claims (5)

In an optical disc recording and reproducing apparatus comprising an optical pickup and an optical detector, a focus error signal detector, a tracking error signal detector, a data processor, a servo controller, a focus servo driver, a tracking servo driver, and a spindle servo, The data processing unit and the servo control unit, A band pass filter for passing the wobble detection signal of the corresponding frequency band detected by the photodetector; A phase inversion section detector for detecting a period of a phase inversion section from the wobble detection signal output from the band filter and outputting a phase inversion section signal; A slicer configured to reduce an amplitude of the wobble detection signal and output a wobble signal; A phase synchronization loop for receiving the phase inversion section signal and the wobble signal and generating and outputting a phase / speed signal having an arbitrary frequency; And an error generator for detecting an error by using the phase / speed signal to generate a normalized spindle rotation voltage and output the same to the spindle servo. The method of claim 1, And a phase inversion section correcting section for correcting the phase inversion section signal outputted from the phase inversion section detecting section. The method of claim 2, And a wobble counter for counting the period of the wobble signal output from the slicer and outputting the phase inversion section correction section. The method of claim 1, And said phase locked loop comprises a low pass filter, an error amplifier and a voltage controlled oscillator. Extracting the wobble from the surface of the optical disc, Determining the speed of recording and reproducing the optical disc; Controlling a phase-locked loop using a wobble signal when the recording and reproducing are low speed; Controlling a phase-locked loop using a phase inversion section signal when the optical disk has a high speed; And rotation of the spindle is controlled by a control voltage generated from the phase locked loop.