KR19980075473A - Apparatus and method for preventing recording errors of DVD system - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DVDR system. In the recording mode of such a DVDR system, a recording error that cannot be compensated for during playback occurs due to continuous external shocks or poor tracking adjustment. In order to prevent, the tracking error detection unit for detecting a tracking failure that the focus error signal is out of a predetermined error tolerance range; A counter for counting a time when the tracking failure is detected in the tracking failure detection unit; A memory for storing time data of a point where the tracking failure occurs in the tracking failure detection unit; If a tracking failure signal is not detected by the tracking failure detection unit, a microcomputer for comparing the time counted by the counter with a preset error failure tolerance time and generating an optical pickup driving control signal corresponding to the comparison result; The performance and reliability of the DVDR system are provided by providing a recording error prevention apparatus for a DVDR system comprising an optical pickup unit for recording data on an optical disc by the drive control signal of the microcomputer, and providing a recording error prevention method for a DVDR system using such a device. Can improve.

Description

Apparatus and method for preventing recording errors of DVD system

The present invention relates to an apparatus and method for preventing a recording error of a DVDR system (Digital Video Disc Recoder System). In particular, when an error occurs when recording data on an optical disc due to a tracking error that occurs outside a tolerance range for a predetermined time, The present invention relates to a recording error prevention device and method for a DVDR system, which is configured to record again from a recording error start point.

In general, optical discs are read-only type in which the user can only play the information according to its function and purpose, and additional recording type and repetitive recording of information that the user can record once and read the recorded information many times but cannot erase and re-record It can be divided into erasing rewritable type that can be erased and reproduced. Among such optical discs, a system capable of recording, erasing and playing on an erasable rewritable optical disc is commonly referred to as a DVDR system.

On the other hand, in order for the optical pickup unit of the DVDR system to accurately record data on the optical disc when recording certain data on such an erased rewritable optical disc, the optical pickup unit must be controlled so as to accurately follow the track of the pitch formed on the optical disc. Controlling such an optical pickup unit to accurately follow a track of a pitch formed on an optical disc is commonly referred to as a tracking servo device.

In the related art, data is recorded on an optical disc while controlling the optical pickup unit to accurately follow the track of the pitch formed on the optical disc by using such a tracking servo device.

However, if the tracking servo is not compensated for more than a certain amount of time even though a continuous shock occurs from the outside to generate a focus error outside the error tolerance for a certain time or a tracking error outside the error tolerance, There has been a problem that the optical pickup unit cannot accurately record data on the optical disc beyond the track of the pitch formed on the optical disc.

Accordingly, the present invention has been made in view of the above-described problems, and an object of the present invention is to provide a tracking error signal out of an error tolerance range when a tracking error signal out of an error tolerance range occurs for a predetermined time or more in a DVDR system. The present invention provides an apparatus and method for preventing a recording error of a DVDR system capable of accurately recording data on an optical disc by recording again from the point where the error occurred.

In order to achieve the above object, in one aspect of the present invention, a photodetector measures a tracking error signal at a current generated by detecting light reflected from the optical disk, and the optical pickup unit is mounted on the optical disk by the measured tracking error signal. A DVDR system having a tracking servo device for controlling to accurately follow a track of a formed pitch; A tracking failure detection unit for detecting a tracking failure in which the tracking error signal is outside a preset error tolerance range; A counter for counting a time when the tracking failure is detected in the tracking failure detection unit; A memory for storing time data of a point where the tracking failure occurs in the tracking failure detection unit; If a tracking failure signal is not detected by the tracking failure detection unit, a microcomputer for comparing the time counted by the counter with a preset error failure tolerance time and generating an optical pickup driving control signal corresponding to the comparison result; An optical pickup unit for recording data on an optical disc by the drive control signal of the microcomputer is provided.

In order to achieve the above object, in another aspect of the present invention, a photodetector measures a tracking error signal at a current generated by detecting light reflected from an optical disk, and the signal surface of the optical disk is determined by the measured tracking error signal. A DVDR system having a tracking servo device for controlling driving of an optical pickup unit so as to be located within a focal depth of a laser beam of an optical pickup unit; A first step of storing time data of a starting point at which the tracking error is detected when a tracking error in which the tracking error signal is out of a predetermined error tolerance range is detected; Counting a time at which the tracking fault is detected;

A second step of comparing a time when the tracking failure counted in the first step is detected with a preset tracking failure tolerance time; And a third step of recording again from the starting point of the detection of the tracking error stored in the first step, if the time when the tracking failure is detected is greater than the tracking error tolerance. Provides a method for preventing recording errors.

1 is a block diagram showing an apparatus for preventing a recording error of a DVD system according to the present invention;

2 is a flowchart illustrating a recording error prevention method of a DVD system according to the present invention;

3 is a waveform diagram showing an output of an adder for explaining the present invention.

<Description of the code | symbol about the principal part of drawing>

110: photodetector 122: first current-voltage converter

124: second current-voltage converter 130: adder

140: comparison unit 200: microcomputer

300: optical pickup unit 400: memory

500: counter

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

1 is a block diagram illustrating a recording error prevention apparatus of a DVDR system according to the present invention, wherein the photodetector 110, the first current-voltage converter 122, the second current-voltage converter 124, The adder 130, the comparator 140, the microcomputer 200, the optical pickup unit 300, the memory 400, and the counter 500 are provided.

In the figure, the functions of the structural members are as follows.

First, the photo detector 110 is composed of two photo diodes D1 and D2 divided into two, and detects the light reflected from the optical disk through the respective photo diodes D1 and D2, and the detected Generates a current corresponding to light.

Each of the first current-voltage converter 122 and the second current-voltage converter 124 includes a resistor R1 at its inverting input terminal, the non-inverting input terminal is grounded, and a loop resistance from the output terminal to the inverting input terminal. It consists of an OP amplifier in which a feedback loop with Rf) is formed.

In the current-voltage converter 122 configured as described above, the current generated from one diode D2 of the photodetector 110 divided into two is converted into a current, and the converted voltage is added to the adder 130. It is provided to one input terminal of.

In addition, the second current-voltage converter 124 also converts the current generated by the other diode D1 of the divided photodetector 110 into a constant voltage, and converts the converted voltage into the adder 300. To other inputs.

At this time, the voltage provided from the current-voltage converters 122 and 124 is output as a product of the loop resistance Rf with respect to the current I generated from the diode, and its phase is inverted. That is, the output voltage is output as -I * Rf.

The adder 130 adds the voltages provided by the first current-voltage converter 122 and the second current-voltage converter 124, and provides the added voltage to the inverting input of the comparator 140. . At this time, the waveform of the added voltage will appear as a voltage waveform having an irregular amplitude and crest with respect to the passage of time in response to a change in the amount of light detected by the photodetector as shown in FIG. 3.

The comparator 140 is composed of an OP amplifier whose inverting terminal is connected to the output terminal of the adder 130, and the non-inverting terminal is provided with the lowest voltage of the error tolerance range, and the output voltage of the adder 130 Is compared with the lowest voltage of the preset tolerance range, and the comparison result is provided to the microcomputer 200.

If the result output from the comparator 140 is 1 (or 'high'), the microcomputer 200 recognizes that a tracking failure occurs when the voltage added by the adder 130 is out of an error tolerance range, and the comparator 140 Stores the time data of the starting point at which 1 is output, that is, the starting point P1 at which the tracking error occurs, and stores the time data in the memory 400 to be described later, and controls the counter 500 to be described later to count.

On the other hand, when the microcomputer 200 outputs 0 (or 'low') from the comparator 140 during the counting in the counter 500, the microcomputer 200 recognizes that the tracking disturbance is stopped, and the tracking failure occurrence time counted by the counter 500. (T) and the error disturbance tolerance time are compared, and a control signal corresponding to the comparison result is generated. At this time, the error error tolerance time refers to a recording error compensable range capable of compensating for and reproducing a recording error during reproduction of an optical disc by a conventional method.

That is, when the tracking failure occurrence time T counted by the counter 500 is greater than the error failure allowable time, the control operation stops the recording operation of the optical pickup unit 300 and stores the tracking error failure starting point stored in the memory 400. After the time data of P1 is extracted, the optical pickup unit 300 is controlled to drive the recording error from the starting point P1.

Under the control of the microcomputer 200, the optical pickup unit 300 records predetermined data on the signal surface of the optical disc.

The memory 400 stores a preset error failure tolerance time and time data of the error failure occurrence start point P1.

The counter 500 sequentially counts the time from the start point of error occurrence P1 to the end of the error failure under the control of the microcomputer 200.

The recording error prevention method of the DVDR system according to the present invention using the recording error prevention apparatus of the DVDR system having the above-described members will be described with reference to FIGS. 1, 2 and 3 as follows.

2 is a flowchart illustrating a recording error prevention method of a DVDR system according to the present invention.

First, when an optical disc is mounted in the DVDR system, the DVDR reads out and stores the TOC information recorded in the load-in section of the optical disc.

Then, when the user through the key input unit (not shown) starts recording the predetermined data on the optical disc in response to the key signal input, the photo detector 110 divides the two photo diodes D1 and D2 divided into two. Through detecting the light reflected from the optical disk, and generates a current corresponding to the detected light.

The current generated in one diode D2 of the divided photodetector 110 is converted into a constant voltage in the first current-voltage converter 122, and the current generated in the other diode D1 is converted into a second current-. The voltage converter 124 is converted into a predetermined voltage and provided to each of two input terminals of the adder 130.

The voltages provided by the first current-voltage converter 122 and the second current-voltage converter 124 are added by the adder 130, respectively, and the added voltage is the non-inverting input terminal of the comparator 140. Is provided. At this time, the waveform of the added voltage will appear as a voltage waveform having an irregular amplitude and crest with respect to the passage of time in response to a change in the amount of light detected by the photo detector 110 as shown in FIG. 3.

The output voltage of the adder 130 is compared with the lowest voltage Vmin of the error tolerance set in the comparator 140, and as a result of the comparison, the output voltage of the adder 130 is the lowest voltage of the preset tolerance. If larger, 0 (or 'low') is output, and if the output voltage of the adder 130 is smaller than the lowest voltage of the preset error tolerance range, 1 (or 'high') is output, and the output result is It is provided to the microcomputer 200.

In this case, if the comparison result of the comparison unit 140 is 0, the focus is within the error tolerance and data is correctly recorded on the optical disc. If the comparison result is 1, the tracking error occurs when the focus error is out of the error tolerance. This means that the data is not recorded correctly on the optical disc. (S 1)

In S 1, when 1 (or 'high') is output from the comparator 140, the microcomputer 200 recognizes that a tracking failure occurs when the voltage added by the adder 130 is out of an error tolerance range, and the comparator ( In operation 140, the counter 500 stores the time data of the starting point at which 1 is output, that is, the starting point at which the tracking error occurs, in the memory 400 (S 2) and controls the counter 500 to count (S 3).

In S 3, when 0 (or 'low') is output from the comparator 140 while the counter 500 counts the tracking failure detection time, the microcomputer 200 determines that the tracking failure is stopped, and the counter ( In step 500, the control stops the count (S 4).

Thereafter, the microcomputer 200 compares the time T counted from the counter 500 at S 3 with the magnitude of the error failure tolerance time preset and stored in the memory 400 (S 5).

As a result of the comparison of S 5, when the counted tracking failure detection time is smaller than the preset error failure tolerance time, the microcomputer 200 controls the recording operation of the optical pickup unit 300 to be maintained (S 9). At this time, the recording error occurring within the error failure tolerance time among the data recorded on the optical disc may be compensated for in the subsequent reproduction of the optical disc.

On the other hand, if the counted tracking failure detection time T is greater than the preset error failure tolerance time as a result of the comparison of S 5, the microcomputer 200 controls the optical pickup unit 300 to stop the recording operation (S 6). After fetching the time data of the tracking failure starting point stored in the memory 400 (S 7), the optical pickup unit 300 is controlled to drive the optical pickup unit 300 to rewrite the data from the tracking failure starting point (S 8).

As described above, according to the present invention, in the recording mode of the DVDR system, if a recording error exceeding a range for compensating for a recording error occurs during reproduction of the optical disc, recording is stopped, the recording is resumed at the start point of the recording error, and the optical disc Accurately recording the data on the CD-ROM can improve the performance and reliability of the DVDR.

Claims (3)

A tracking servo that measures a tracking error signal at a current generated by detecting light reflected from the optical disk, and controls the optical pickup portion of the optical disk to accurately follow the track of the pitch formed on the optical disk by the measured tracking error signal. 10. A DVDR system with apparatus; A tracking failure detection unit for detecting a tracking failure in which the tracking signal is out of a predetermined error tolerance range; A counter for counting a time when the tracking failure is detected in the tracking failure detection unit; A memory for storing time data of a point where the tracking failure occurs in the tracking failure detection unit; If a tracking failure signal is not detected by the tracking failure detection unit, a microcomputer for comparing the time counted by the counter with a preset error failure tolerance time and generating an optical pickup driving control signal corresponding to the comparison result; And an optical pickup unit for recording data on the optical disc by the drive control signal of the microcomputer. The apparatus of claim 1, wherein the tracking fault detection unit; Two sets of current-voltage converters for converting and generating a current generated by the photodetector into a voltage; An adder for adding a voltage output from each of the two sets of current-voltage converters; And a comparator for comparing whether the voltage added by the adder is out of a predetermined error tolerance range. A tracking servo that measures a tracking error signal at a current generated by detecting light reflected from the optical disk, and controls the optical pickup portion of the optical disk to accurately follow the track of the pitch formed on the optical disk by the measured tracking error signal. 10. A DVDR system with apparatus; A first step of storing time data of a starting point at which the tracking error is detected when a tracking error in which the tracking error signal is out of a predetermined error tolerance range is detected; Counting a time at which the tracking fault is detected; A second step of comparing a time when the tracking failure counted in the first step is detected with a preset tracking failure tolerance time; And a third step of recording again from the starting point of the detection of the tracking error stored in the first step, if the time when the tracking failure is detected is greater than the tracking error tolerance. How to avoid recording errors.