KR100432847B1 - An apparatus and method for detecting wobble signal - Google Patents

Abstract

The present invention relates to a wobble signal detection device and a detection method, and the wobble signal detection method according to the present invention is a method for performing a recording operation by one main beam and at least one sub-beam, wherein the plurality of beams during the recording operation are performed. Detecting a reflected signal on the recording medium by the first step; And a second step of selectively outputting the detected plurality of reflected signals according to a current recording speed to generate a wobble signal, and outputting the wobble signal. It is a very useful invention that a stable and high speed recording operation is achieved by generating a noise-free wobble signal using the sub-beam reflection signal and the main beam reflection signal, and performing a spindle control operation and a recording operation based on the sub-beam reflection signal and the main beam reflection signal.

Description

An apparatus and method for detecting wobble signal

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for detecting a wobble signal, and more particularly, to an apparatus and method for performing a spindle control operation and a recording operation using a wobble signal.

In general, an Absolute Time In Pre-Groove (ATIP) frame of FIG. 1 including time information and disc recognition information of an optical disc is FM-modulated at a low frequency (22.05 kHz) by the ATIP encoder shown in FIG. It is recorded in the form of a wobble signal.

FIG. 3 shows a detailed configuration of an optical pickup 41 and a wobble signal generating unit 61 of a general optical disc apparatus. As shown in FIG. 4, the optical pickup 41 includes main beams A, B, C, Data recording is performed using D) and side beams (E, F). Accordingly, the wobble signal generating unit 61 performs a main beam of the reflected signals of the main beam and the sub-beam of the optical pickup 10 during data recording. The wobble signal is generated using only the reflected signals A, B, C, and D. Accordingly, the optical disk apparatus detects ATIP data by decoding the generated wobble signal. That is, the optical disk device detects the ATIP data by sampling a specific playback pulse section (for example, 5T) from the reflected signal of the main beam during data recording. As described above, the ATIP data is FM-modulated at low frequency. Therefore, the ATIP data can be detected even by sampling only a short playback pulse section (for example, 5T), and the optical disk apparatus performs the spindle control and recording operation based on the detected ATIP data.

However, under high speed (20 times or more), under / over shots are severely generated when the recording pulse falls, and as described above, even when a specific playback pulse section is sampled, under As shown in FIG. 5 due to the overshoot, the noise is severe and it is difficult to accurately detect ATIP data, which causes a problem in that spindle control and recording operations are not normally performed.

In addition, in order to reduce noise relatively, if sampling is performed in a section of 6T or more, ATIP data may be lost if the frequency of occurrence in the section of 6T or more is low, and in this case, the spindle control is in an inoperable state. There was a problem that could not be achieved.

Accordingly, the present invention was created to solve the above problems, and generates a wobble signal from which noise is removed from reflection signals of one main beam and a plurality of sub-beams, and uses the generated wobble signal. It is an object of the present invention to provide a wobble signal detection device and a detection method for more accurate spindle control operation and high speed recording operation.

1 shows an example of a format of an Absolute Time In Pre-Groove (ATIP) frame recorded on an optical disc,

Fig. 2 shows a detailed configuration of an ATIP encoder in a general optical disk device.

3 shows a wobble signal generation block of a general optical disc apparatus,

FIG. 4 illustrates the forms of a main beam and a side beam generated from the optical pickup of FIG.

FIG. 5 shows an example of noise generated when data is recorded by the apparatus of FIG.

FIG. 6 is a block diagram showing an exemplary embodiment of an optical disk apparatus in which a wobble signal detection apparatus according to the present invention is implemented.

FIG. 7 illustrates a detailed configuration of the optical pickup and wobble signal generation unit of FIG. 6;

FIG. 8 illustrates the shapes of the main beam and the sub-beam generated from the optical pickup of FIG. 6 as an example.

Figure 9 shows the flow of a preferred embodiment of the wobble signal detection method according to the present invention.

※ Explanation of code for main part of drawing

10: optical disc 11: spindle motor

20a: digital recording signal processor 20b: digital reproduction signal processor

30: channel bit encoder 31: optical driver

40, 41: Optical pickup 50: R / F part

60, 61: wobble signal generation unit 70: ATIP decoder

80: servo unit 81: drive unit

90: micom

A wobble signal detecting apparatus according to the present invention for achieving the above object, in the recording apparatus for performing a recording operation by one main beam and at least one sub-beam, during the recording operation, recording by the plurality of beams Optical pickup means for respectively detecting a reflected signal on the medium; Double speed detecting means for detecting a current recording double speed; And wobble signal generating means for selectively generating a wobble signal by selectively calculating the plurality of reflected signals detected according to the detected recording speed;

In addition, the wobble signal detection method according to the present invention is a method for performing a recording operation by one main beam and at least one sub-beam, comprising: a first signal for detecting a reflected signal on a recording medium by the plurality of beams during a recording operation; step; And a second step of generating a wobble signal by selectively performing a predetermined operation on the detected plurality of reflected signals in accordance with the current recording double speed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a wobble signal detecting apparatus and a detecting method according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 6 is a block diagram illustrating an exemplary embodiment of an optical disk device in which a wobble signal detection device is implemented according to the present invention. The error correction code (ECC) is added to digital data input from an external host. A digital recording signal processing unit 20a for converting to a recording format; A channel bit encoder (30) for reconverting the data converted into the recording format into a bitstream; An optical driver 31 for outputting a light quantity driving signal according to the input signal; An optical pickup (40) for recording a signal on the optical disc (10) in accordance with the light quantity driving signal and for detecting a recording signal from the recording surface; An R / F unit 50 for outputting a servo signal (focus error signal (F.E) and tracking error signal (T.E)) and a high frequency reproduction signal from the signal detected by the optical pickup 40; A digital reproduction signal processor (20b) for restoring the output high frequency reproduction signal to original data; A wobble signal generation unit 60 generating and outputting a wobble signal from the reflected signals of the main beam and the sub-beams output from the optical pickup 40; ATIP decoder 70 for decoding ATW (Absolute Time In Pre-Groove) data by decoding the wobble signal output from the R / F 50 at the time of detecting a specific playback pulse section (for example, 5T) during data recording. ); A drive unit 81 for driving the optical pickup 40 and the spindle motor 11; A servo unit (80) for controlling driving of the drive unit (81) from the output servo signal and ATIP data and the rotational speed of the optical disc (10); And a microcomputer 90 for controlling and performing recording and reproducing operations.

FIG. 7 shows a detailed configuration of the optical pickup 40 and the wobble signal generating unit 60. The optical pickup 40 uses a two-part photo detector, and the main beam as shown in FIG. And a sub-beam to perform a recording operation. During the recording operation, the wobble signal generation unit 60 reflects the sub-beam reflected signal and the main beam reflected signal from the two-segment photodetector of the optical pickup 40. Generate a push-pull signal from the, which will be described in detail later.

9A and 9B illustrate the flow of a preferred embodiment of the wobble signal detection method according to the present invention. Hereinafter, the wobble signal detection of FIGS. 9A and 9B according to the present invention will be described with reference to the configurations of FIGS. 6 and 7. The method will be described in detail.

First, when the optical disc 10 is inserted into a tray (not shown), and the recording request for data input from the outside through the microcomputer 90 is received, the microcomputer 90 is The spindle motor 11 is driven by the servo unit 80 and the drive unit 81 to rotate and drive the optical disc 10, and the optical pickup 40 is moved to the corresponding recording area on the optical disc 10. The recording operation is performed by moving to. The recording operation is as follows.

The digital recording signal processing unit 20a generates an error correction code (ECC Block) by adding an encoding and an error correction parity for reliability of recording / reproducing the input coded data, and the channel bit encoder. 30 converts the digital bitstream output from the digital recording signal processing unit 20a into a pulse width modulated signal form for recording on the optical disc 10, and applies the signal to the optical driver 31. 90 controls the optical driver 31 so that the recording signal is output by the optical driving current corresponding to the detected optimal recording optical power value. Accordingly, the optical driver 31 outputs a signal for recording data at an optical driving power corresponding to the applied pulse width modulated signal, so that the optical pickup 40 is applied to a program area of the optical disc 10. The data is to be recorded. At this time, the optical pickup 40 performs a recording operation while generating a main beam and a sub-beam on the optical disk 10 as shown in FIG.

According to the recording operation, the optical pickup 40 detects the reflected signals of the main beam and the sub-beam, respectively, and outputs them to the wobble signal generation unit 60. In this case, the optical pickup 40 includes A, B, A reflection signal of the sub-beams of E1, E2, F1, and F2 is output to the wobble signal generation unit 60 by using a two-segment photodetector together with the reflection signals of the C, D main beams.

However, if the recording operation is recording at the normal speed (20 times or less), since the switch SW in the wobble signal generation unit 60 is connected to the b terminal by the microcomputer 90, The wobble signal generation unit 60 generates and outputs a wobble signal from the reflection signals A, B, C, and D of the main beam output from the optical pickup 40, and the reflection signals E1, Offset adjustment signal is output from E2, F1, F2). As described above, the wobble signal generation unit 60 uses the reflection signal of the sub-beam only at the normal speed as the offset adjustment signal. This is because the sub-beam power is about 1/20 of the main beam power at the normal speed, and thus the ATIP data This is because it cannot be detected (S21).

Subsequently, the ATIP decoder 70 samples and decodes the wobble signal output from the wobble signal generation unit 60 at the time of detecting a specific playback pulse section (for example, 5T) of the R / F unit 50 to perform ATIP. The data is detected, and the microcomputer 90 performs a recording operation while appropriately controlling the spindle motor 11 based on the detected ATIP data.

By the way, if the above recording operation is high-speed recording (more than 20 times speed) recording (S20), the switch SW in the wobble signal generation unit 60 is connected to terminal a by the microcomputer 90, The wobble signal generation unit 60 is a wobble signal from the reflection signal (A, B, C, D) of the main beam and the reflection signal (E1, E2, F1, F2) of the sub-beam output from the optical pickup 40 That is, the wobble signal generation unit 60 generates a push-pull signal of (A + D)-(B + C) by calculating a predetermined reflection signal of the output main beam, and also the optical The reflection signals E1, E2, F1, and F2 of the sub-beams respectively output from the two two-segment photodetectors of the pickup 40 are subjected to a predetermined operation, gain, and phase adjustment to (E1-E2) + (F1-F2). A push-pull signal is generated (S30).

As such, when the push-pull signal is generated from the reflected signals of the main beam and the sub-beams, the wobble signal generation unit 60 performs a predetermined operation on the push-pull signal by the generated main beam and the push-pull signal by the sub-beam. That is, by summing, the noise is canceled and the signal component generates and outputs the amplified wobble signal (S31).

Accordingly, as described above, the ATIP decoder 70 outputs the wobble signal output from the wobble signal generation unit 60 at the time of detecting a specific reproduction pulse section (for example, 5T) of the R / F unit 50. Sampling and decoding to detect ATIP data (S32), the microcomputer 90 performs a more stable spindle control and recording operation based on the detected ATIP data (S32), such a recording operation is completed recording It continues to be made until (S40).

As described above, since the LD output power of the optical pickup 40 is large in high-speed recording, the ATIP data can be detected even if only the specific reproduction pulse section is sampled even though the subbeam power is about 1 / 20th of the main beam power. As a result, more stable spindle control and high speed recording operation can be performed.

The above-described preferred embodiments of the present invention are disclosed for purposes of illustration, and those skilled in the art can improve, change, and substitute various other embodiments within the technical spirit and scope of the present invention disclosed in the appended claims below. Or addition may be possible.

The wobble signal detection device and method according to the present invention configured as described above generate a noise-free wobble signal by using a sub-beam reflection signal and a main beam reflection signal output from a two-part photodetector of an optical pickup. By performing the spindle control operation and the recording operation on the basis, it is a very useful invention that a more stable high speed recording operation is achieved.

Claims (8)

A recording apparatus for performing a recording operation by one main beam and at least one sub beam, Optical pickup means for detecting a reflected signal on a recording medium by the plurality of beams during a recording operation; Double speed detecting means for detecting a current recording double speed; And And a wobble signal generating means for selectively generating and outputting a wobble signal by selectively performing a predetermined operation on the detected plurality of reflected signals according to the detected recording speed. The method of claim 1, And a control means for controlling spindle rotation during a recording operation based on the generated wobble signal. The method of claim 1, The generation of the wobble signal is a wobble signal detection apparatus, characterized in that the predetermined reading section is made. The method of claim 1, The one or more sub-beams each wobble signal detection device characterized in that consisting of a split detector. The method of claim 1, When the detected recording speed is a normal speed, the wobble signal generating means generates and outputs a wobble signal by performing a predetermined operation on the reflection signal of the plurality of detected reflection signals and a reflection signal of the subbeam by a predetermined operation. And a signal processing to generate and output an offset adjustment signal. In the method for performing a recording operation by one main beam and at least one sub-beam, Detecting a reflected signal on the recording medium by the plurality of beams during a recording operation; And And a second step of selectively outputting the detected plurality of reflected signals according to a current recording speed to generate and output a wobble signal. The method of claim 1, And the wobble signal generating means generates and outputs a wobble signal by predetermined operation of the reflected signal by the detected main beam and the reflected signal by the sub-beam when the detected recording speed is high. The method of claim 7, wherein The wobble signal generating means generates a push-pull signal by performing a predetermined operation on the detected reflection signal of the main beam, and generates a push-pull signal by performing a predetermined operation, gain, and phase adjustment on the reflection signal of the sub-beam. The wobble signal detection device, characterized in that for generating the output of the wobble signal by the predetermined operation of each push pull signal again.