KR20040004734A - Method for detecting a defect area in optical disc driver - Google Patents

Abstract

PURPOSE: A defect area detecting method for an optical disc system is provided to detect a defect area of an optical disc on the basis of level of signals reflected and photoelectric transformation by a space section formed by deletion light power level, thereby detecting the defect area precisely and preventing the data recording error for the defect areas. CONSTITUTION: A defect area detecting method for an optical disc system includes the steps of setting a data recording mode by a control part(S10), and encoding and modulating external input data to proper recording signals by controlling the operation of a recording waveform generating part, a modulation part and an encoder(S11). A recording light power level and deletion light power level of laser diodes of an optical pickup are variably controlled for carrying out data recording operation for forming marks and spaces on tracks of the optical disc(S12). If an RF signal detected and photoelectrically transformed from a photo detector is received via a low pass filter, level of the signal is detected(S13). The RF signal level is used for determining whether the RF signal is reflected by a space section of the optical disc(S14). The RF signal level is compared with a preset reference level corresponding to the deletion light power level(S15). If a difference between the levels exceeds an allowable error level range(S16), the recording position is determined to be in a defect area(S17). A defect compensation recording operation is carried out for recording data to normal data recording area except the defect area(S18).

Description

Method for detecting a defect area in optical disc driver

The present invention is directed to an optical disc apparatus for detecting a defect area of an optical disc when performing a data recording operation for recording external input data on an optical disc such as a CD-RW (CD-Rewritable) or the like. It relates to a method for detecting a defect area.

Recently, an optical recording medium capable of recording and storing high quality digital video data and high quality digital audio data for a long time, for example, an optical disc such as a rewritable CD (RW-RW), has been widely used and commercialized.

On the other hand, in an optical disc device such as a CD-RW driver capable of recording or storing data on a rewritable CD-RW, such as a CD-RW driver, external input data such as video and audio data may be used. After encoding and modulating the recording signal into a recording signal suitable for recording, the optical power level of the laser diode included in the optical pickup is variably adjusted to determine a mark and a space corresponding to the recording signal. It is formed and recorded on the track of the optical disc.

In the optical disk apparatus, while performing a data recording operation, the level of the signal reflected and photoelectrically converted by the mark and space is detected and confirmed, and then the defect area of the optical disk is detected based on the signal level.

For example, when the level of the signal reflected and photoelectrically converted by the mark and space is lower than a predetermined reference signal level, the recording position is changed to a defect area in which foreign matter or scratches exist. By detecting and recording the data in the normal data recording area excluding the defect area, data recording errors can be prevented in advance.

However, since the level of the signal reflected and photoelectrically converted by the mark formed on the optical disk is detected as an irregular signal level according to the waveform of the recording signal, a problem that frequently causes an error in the defect area detection operation is caused. have.

Accordingly, the present invention has been made to solve the above problems, and the present invention is directed to a level of a signal reflected and photoelectrically converted by a space section formed on a track of an optical disc such as a rewritable CD-RW or the like. SUMMARY OF THE INVENTION An object of the present invention is to provide a defect area detection method in an optical disk device for more accurately detecting a defect area of an optical disk.

1 illustrates a configuration of an optical disk apparatus to which the defect area detecting method according to the present invention is applied.

FIG. 2 shows Marks and Spaces recorded on tracks of a rewritable optical disc;

3 shows the waveform and the optical power level of the HF recording signal corresponding to the waveform of the EFM signal,

4 is a flowchart illustrating a defect area detection method in the optical disk device according to the present invention.

※ Explanation of code for main part of drawing

10: optical disc 11: optical pickup

12: LD drive unit 13: recording waveform generation unit

14 modulator 15 encoder

16 control unit 17 low pass filter

Defect area detection method in the optical disk apparatus according to the present invention for achieving the above object, by encoding and modulating the external input data into a signal suitable for recording, and recording on the optical disk while recording as a mark and a space on the optical disk, Detecting a level of the signal reflected and photoelectrically converted by the first step; And detecting the defect area of the optical disc based on the level of the signal when the photoelectrically converted signal is a signal reflected by the space section.

Hereinafter, a preferred embodiment of a defect area detection method in an optical disk device according to the present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 shows a configuration of an optical disk device to which the defect area detecting method according to the present invention is applied. For example, a rewritable optical disk 10 may be used in an optical disk device such as a CD-RW driver. ) May include an optical pickup 11 for recording data, a laser diode (LD) driver 12, a recording waveform generator 13, a modulator 14, and an encoder 15.

Also, a low pass filter for removing high frequency components of a signal detected and photoelectrically converted from a control unit 16 for controlling the operation of the components and a photo detector (not shown) included in the optical pickup. 17 may be configured to include.

And. The control unit 16 controls the respective constituent means, encodes and modulates external input data such as video and audio data into a recording signal suitable for recording, and then stores the optical power of the laser diode included in the optical pickup ( Optical Power) level is variably adjusted to form and record marks and spaces corresponding to the recording signals on the tracks of the optical disc.

On the other hand, the marks and spaces formed on the tracks of the optical disc have a run-length length of 3 T to 11 T, as shown in Fig. 2, and the recording light set to form the marks. The write power (Pw) is higher than the erase optical power level (Pe: Erase Power) set to form the space, and the erase optical power level (Pe) is a bias optical power level (Pb: Bias Power). It is set higher.

In the LD driver 12, as shown in FIG. 3, the recording optical power level Pw of the laser diode included in the optical pickup according to the waveform of the recording signal modulated by the EFM (Eight to Fourteen) method. ) And erase optical power level Pe are variably adjusted to form and record marks and spaces on the tracks of the optical disc, respectively.

On the other hand, the control unit 16 detects the level of the relatively stable RF signal reflected and photoelectrically converted by the space section, and then detects the defect area of the optical disk accurately based on the RF signal level. The detection operation is performed, which will be described in detail below.

Fig. 4 shows an operation flowchart of the defect area detection method in the optical disc apparatus according to the present invention, for example, requesting recording of external input data on an optical disc such as the rewritable CD (CD-RW). When a user key is input, the controller 16 sets a data recording mode (S10), and controls the recording waveform generator 13, the modulator 14, and the encoder 15 to operate. The external input data is encoded and modulated into a recording signal suitable for recording (S11).

Then, the LD driver 12 is operatively controlled to variably adjust the recording optical power level Pw and the erasing optical power level Pe of the laser diode included in the optical pickup 11 to mark on the track of the optical disc. And a series of data recording operations for respectively forming and recording spaces (S12).

On the other hand, in the control unit 16, the RF signal that is reflected by the mark and space that is recorded and formed through the above-described process, and detected and photoelectrically converted from the photo detector PD included in the optical pickup, passes through the low pass. When the input is received through the filter 17, the level of the RF signal is detected (S13).

In addition, it is checked whether the level of the RF signal is the RF signal reflected by the space section of the optical disk (S14). For example, in the LD driver 12, the optical power level for data recording is deleted. The RF signal detected in the state of being variably adjusted to the optical power level Pe is identified and identified as the RF signal reflected by the space section.

In addition, the controller 16 compares the level of the RF signal with a predetermined reference level preset, for example, the reference level corresponding to the erase optical power level Pe (S15). When the difference value between these exceeds the tolerance level range (S16), it detects and discriminates as the defect area | region where a scratch or a foreign material exists in the recording position (S17).

As a result, the normal defect compensation recording operation for recording data in the normal data recording area excluding the defect area is performed (S18), so that the defect area can be detected more accurately, resulting in the defect area. It is possible to prevent a recording error of recording data in advance.

For reference, the present invention is applicable to another optical disk device other than the CD-RW driver (CD = RW Driver) and another rewritable optical disk other than the CD-RW.

As mentioned above, preferred embodiments of the present invention are disclosed for the purpose of illustration, and those skilled in the art can improve and change various other embodiments within the spirit and technical scope of the present invention disclosed in the appended claims below. , Replacement or addition would be possible.

The defect area detection method in the optical disk apparatus according to the present invention as described above comprises a mark and a space formed on a track of an optical disk such as a rewritable CD (RW-RW) or the like. Defect area of the optical disc is detected based on the level of the signal reflected and photoelectrically converted by the space section formed and recorded by the erased optical power level Pe, which is more stable than the recording optical power level Pw for forming. By doing so, it is possible to detect the defect area more accurately, and it is a very useful invention that it is possible to prevent a recording error of recording data in the defect area in advance.

Claims (2)

Encoding and modulating external input data into a signal suitable for recording, detecting the level of a signal reflected and photoelectrically converted by the optical disk while recording in marks and spaces on the optical disk; And And when the photoelectrically converted signal is a signal reflected by the space section, detecting the defect area of the optical disk based on the level of the signal. How to adjust the recording speed. The method of claim 1, In the second step, when the level of the photoelectric conversion signal detected while the level of the laser light power is adjusted to a preset erasure light power level exceeds the preset tolerance level, the optical disc is detected as a defect area of the optical disc. A data recording speed control method in an optical disk device, characterized in that.