KR20010025993A - Method for defect area processing of optical recording medium - Google Patents

Abstract

PURPOSE: A method for processing a defect area of an optical recording medium is provided to perform a normal replaying in the defect area, depending on whether an error is corrected, or to jump up to other track during the defect area to perform the normal replaying, so as to efficiently process a defect and to stably perform a servo. CONSTITUTION: If a defect is generated(303) during a normal replaying(301), a focus servo holds a tracking servo in a turned-on state and records a defect start position(303). The focus servo maintains a tracking servo state until an RF signal is normally detected, after turning off the tracking servo. If the RF signal is normally detected(304), the focus servo turns on the tracking servo and records an end position of a defect area(305). The focus servo decides whether a position of the turned-on tracking servo is an original track in a normal state(306). If the position is an outer track(307), the focus servo moves to an inner track of the original track by a backward jumping(308), and performs a normal replaying until the focus servo meets the defect area(309,310). If the focus servo meets the defect area, the focus servo decides whether data of the defect area is capable of performing an error correction(311). If not, the focus servo performs a backward jumping to the inner track(312), and performs a normal replaying during length of the defect area(313). The focus servo performs a forward jumping to the original track(314) and replays the original track(315).

Description

Method for defect area processing of optical recording medium

The present invention relates to a defect area processing method of an optical recording medium.

In general, optical recording media, in particular optical disks, can be classified into a read only ROM type, a write once type Worm type, and a rewritable type that can be repeatedly recorded, depending on whether repeat recording is possible. It is divided into three kinds.

Here, the ROM type optical disc includes a compact disc read only memory (CD-ROM) and a digital versatile disc read only memory (DVD-ROM), and a warm type optical disc is a write once compact disc. (Recordable Compact Disc; CD-R) and Recordable Digital Versatile Disc (DVD-R). In addition, freely and repeatedly rewritable discs include a rewritable compact disc (CD-RW) and a rewritable digital versatile disc (DVD-RAM, DVD-RW, DVD + RW). .

Fig. 1 is a general block diagram of such an optical disc recording / reproducing apparatus. In the optical disc 101, a signal track has a structure of lands and grooves. You can record or play back all data.

At this time, the optical pickup 102 causes the light beam focused on the objective lens to be placed on the signal track of the optical disk 101 under the control of the servo control unit 106, and also condenses the light reflected by the signal recording surface back to the objective lens. It then enters a photo detector (not shown) for detection of the focus error signal and tracking error signal.

The photo detector includes a plurality of photo detectors, and an electrical signal proportional to the amount of light obtained from each photo detector is output to the RF and servo error generator 104. The RF and servo error generator 104 detects an RF signal for data reproduction, a focus error signal FE for servo control, a tracking error signal TE, and the like from the electrical signal output from the photo detector. At this time, the RF signal is output to the decoder 105 for reproduction, servo error signals such as FE and TE are output to the servo controller 106, and a control signal for data recording is output to the encoder 103.

The encoder 103 encodes data to be recorded into recording pulses in a format required by the optical disk 101, and then records the data on the optical disk 101 through the optical pickup 102, and the decoder 105 transmits the RF. Restore the original form of data from the signal.

On the other hand, a host such as a PC may be connected to the optical disc recording and reproducing apparatus, and the host transmits a recording / reproducing command to the microcomputer 112 through the interface 111, and records to the encoder 103. The data is transmitted, and the reproduced data is transmitted from the decoder 105. The microcomputer 112 controls the encoder 103, the decoder 105, and the servo controller 106 according to a recording / reproducing command of the host.

In this case, the interface 111 typically uses ATAPI (Advanced Technology Attached Packet Interface). In other words, ATAPI is an interface standard between an optical recording / playback device such as a CD or DVD drive and a host, and it is a standard proposed to transmit data decoded by an optical recording / playback device to a host. It converts the protocol into an in-packet form and transmits it.

The servo controller 106 processes the focus error signal FE to output a driving signal for focusing control to the focus servo driver 107, and processes the tracking error signal TE to signal the tracking control. The driving signal is output to the tracking servo driver 108.

At this time, the focus servo driver 107 moves the optical pickup 102 up and down by driving the focus actuator in the optical pickup 102 so that the optical disc 101 follows the vertical movement along with the rotation.

Then, the tracking servo driver 108 corrects the position of the beam by moving the objective lens of the optical pickup 102 in the radial direction by driving the tracking actuator in the optical pickup 102, and follows a predetermined track. do.

In addition, the servo control unit 106 detects the rotational speed information of the disk from the RF signal and outputs it to the spindle servo 109. The spindle servo 109 rotates the disk 101 by controlling a phase locked loop (PLL) of the spindle motor 110 according to the rotation speed information. That is, the spindle motor 110 gives a rotational force to the spindle (not shown) for the rotation of the disk 101, the spindle transmits the rotational force given by the spindle motor 110 to the disk 101 to convey the disk 101. Rotate at the desired speed.

On the other hand, an optical disk recorded or reproduced by such an optical disk recording / reproducing apparatus may cause defects on the disk due to scratches on the surface, dust such as dust, errors in production, and the like. Also, in the case of a rewritable optical disc, the mixing ratio of the mixture constituting the recording layer differs from the initial mixing ratio depending on the degree of rewriting, and loses its characteristics. May appear.

In this case, the defect may occur across several tracks as shown in FIG. 2, or may occur long along the tracks. Usually, the former case is called a short defect and the latter case is called a long defect. That is, short scratches in the tracking direction are called short defects and long scratches are long defects.

Conventionally, the servo system is properly designed to ignore the short defect, and the long defect is processed by turning off the tracking servo and turning on the tracking servo after a certain time. In other words, when the tracking servo is turned off, the tracking servo is held at the value when the defect is encountered. This is because long defects often do not produce a signal enough to track.

However, when the tracking servo is turned off and on again in the defective area, the tracking may be turned on at a position other than the normal position (that is, the position where the defect ends). This is particularly likely to occur as the defect area is longer, and may be caused by disc eccentricity or the like.

Therefore, in this case, there may be a problem in that the data of the area where the original tracking servo should be turned on may not be recovered, thereby causing a discontinuity of the reproduction data, thereby lowering the reproduction capability. In particular, as the position where the tracking servo is turned on moves away from the original position, more data cannot be recovered and lost. In addition, if the position at which the tracking servo is turned on is the inner circumferential side than the original position, the disk may also pop. This also makes the tracking servo unstable.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a method for processing a defective area of an optical recording medium which improves the continuity of reproduction data while stably performing a servo.

1 is a block diagram of a general optical disc recording and reproducing apparatus

2 is a general view showing the structure of a defective optical disk;

3 is a flowchart for performing a defect area processing method according to the present invention.

4 is a diagram of the present invention showing a process of a defective optical disk on the disk;

According to an aspect of the present invention, there is provided a method for processing a defective area of an optical recording medium, the method comprising: identifying a defective area and detecting a length of the defective area; Performing normal playback by turning on the tracking servo and jumping to an inner track of the original track; checking whether there is an error correction of data when encountering the defect area; and normalizing in the defect area according to the error correction. Performing normal playback or jumping to another track during the defective area to perform normal playback.

In the above step, if the position when the tracking servo is turned off and on is the original track and the reproduction data is continuous, the normal reproduction is performed as it is.

If it is determined in the step that error correction is not possible, it is characterized by backward jumping to the inner track, normal playback during the defective area, and forward jumping back to the original track.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

For example, when the defective area is encountered while playing an optical disc, the tracking servo is turned off and the tracking servo is turned on at the end of the defective area. During playback, it is determined whether the data in the defective area is error correctable. If error correction is possible, the defect area is normally played back as it is. If error correction is not possible, playback is performed by jumping to another track during the defect area.

FIG. 3 is a flowchart illustrating a defect area processing method of the present invention, and FIG. 4 illustrates the defect area processing process of FIG. More effective.

That is, if a defect is found during normal playback of the #Nth track (step 301) (step 302), the focus servo holds the tracking servo in the on state and records the defect start position (step 303). For example, the defect is mainly a long defect, in particular, a case in which no signal is enough to track. If the defect is a short defect, the defect may be simply ignored at this time.

Here, there may be a number of methods for determining the defect area, the present invention, for example, is determined by using an RF signal. That is, since the RF signal is not properly detected in the defect area, in particular, if the RF signal changes abruptly, it is determined that there is a defect, and until the RF signal is normally detected, it is regarded as a defect.

At this time, the length of the defect area can be known by counting the time from the start to the end of the defect area. In addition, the length of the defect area can also be known by using a frequency generation (FG) signal generated when the spindle motor rotates. That is, the length of the defect area can be known by counting the FG signal when a defect is encountered.

Therefore, after the tracking servo is turned off in step 303, the tracking servo hold state is maintained until the RF signal is normally detected, and when the RF signal is normally detected, that is, OK (step 304), the tracking servo is turned on. The end position of the defect area is recorded (step 305). At this time, the length of the defective area can also be recorded.

Then, it is determined whether the position when the tracking servo is on and in the normal state is the original track #N (step 306). At this time, there may be various methods for determining the position when the tracking servo is turned on and in the normal state. In the case of the DVD-RAM, the header for recording the sector address may be known.

Here, if the original track #N and continuity exist in the playback data, normal playback can be performed as it is (step 315). Etc.

On the other hand, if the position when the tracking servo is on and normal is the outer track than the original track (step 307), the inner track (eg, # N-1 or # N-2) of the original track by backward jump is performed. In step 308, normal regeneration is performed until the defect area is met (steps 309 and 310).

If the position when the tracking servo is on and the normal state is a track inside the original track, normal playback is performed until the defective area is met. In this case, if the track is too far inside the original track, normal playback may be performed by moving to the track immediately inside the original track (eg, # N-1 or # N-2) by a forward jump. Here, when the position when the tracking servo is on and the normal state is not the original track, moving to the inner track of the original track to perform normal playback is because the inner track is usually safer than the outer track, and the defective area This is to accumulate data for error correction. That is, the data obtained while performing normal playback as described above is stored without discarding.

Then, when the defective area is encountered, the length of the defective area and the stored previous data are used to determine whether the data of the defective area is error correctable (step 311).

If it is determined in step 311 that error correction is possible, normal reproduction is performed in the defect area as it is (step 315).

On the other hand, if it is determined in step 311 that error correction is not possible, the tracking and hold must be performed again in the defect area. By jumping (step 312), normal reproduction is performed during the defect area length (step 313). At this time, a defect in the track direction may span several tracks, and the number of track jumps depends on the defect area.

After the above step 313 is performed, forward jump back to the original track (step 314), and normal playback of the original track #N is performed (step 315).

As described above, according to the defect area processing method of the optical recording medium according to the present invention, the servo can be stably performed by efficiently processing the defect. In addition, it is possible to improve the continuity of the reproduction data, thereby increasing the possibility of reconstruction of the video or audio. In addition, the economics can be improved by performing such an operation by an algorithm without additional hardware. In particular, the present invention is more effective for long defect processing in the track direction.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims.

Claims (3)

A method of processing a defect on an optical record carrier, Identifying a defect area and detecting a length of the defect area; Tracking and holding the skipped defect area; Turning on the tracking servo and jumping to an inner track of the original track to perform normal playback; Checking whether there is an error correction of data when the defect area is encountered; And And normal playback in the defective area or jumping to another track during the defective area in accordance with the error correction. The method of claim 1, And the normal reproduction is performed as it is if the position when the tracking servo is turned on after the off in the step is the original track and the continuity in the reproduction data is performed. The method of claim 1, And if it is determined in the step that error correction is not possible, backward jumping to the inner track, normal playback during the defective area, and forward jumping back to the original track.