JPH01184765A - Optical disk device - Google Patents

Abstract

PURPOSE:To reduce unnecessary error correction in an error correcting circuit at the time of data reproduction and to shorten the processing time of data reproduction by providing the title device with a deciding circuit for deciding whether data to be reproduced are to be outputted to the error correcting circuit or not based on the compared result of a comparator circuit. CONSTITUTION:An error of data to be recorded is corrected by the error correcting circuit 26 and a synchronizing signal is added to each prescribed position of the data to be recorded to record the data. At the time of reproducing data, a synchronizing signal obtained by adding a detecting gate formed by a gate forming circuit 32 to reproduced data is detected, the detected synchronizing signal is counted by counters 33, 34 and the number of synchronizing signals counted by the counter is compared with the number of synchronizing signals to be added at the tie of recording data by the comparator circuit 35. The deciding circuit 27 decides whether the data to be reproduced are to be outputted to the error correcting circuit 26 or not based on the compared result. After obtaining the decided result, the data to be reproduced are outputted to the circuit 26 to correct the error. Consequently, time required for data reproducing can be shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical disc device that records and reproduces data on an optical disc whose recording area is divided into a plurality of sectors.

[Conventional technology]

Optical disks with concentric or spiral trunks, each of which is divided into sectors, - for boat fishing;
Data recording and reproduction is performed in sector units.

Figure 2 shows 130 (International
Organization for 5 standards
zation) is a diagram showing an example of the data format of one sector on an optical disc that is compliant with
Assuming 360 bytes, each sector consists of the trunk address, sector address, etc. of the sector, and is divided into a 52-byte address section, which is recorded in advance when the optical disc is manufactured, and a 1274-byte data section, in which user data, etc. are recorded. Separated.

FIG. 3 is a diagram showing an example of the data format of the data section, in which 1024 bytes of user data (DI to D10
24), 12 bytes of control data (PI
, 1 to P3, 4), 4-byte check data (CRC-1 to CRC-4) for detecting data correction errors, and error check code (EC
C) 160 bytes of parity bits (El, 1~
EI0.16) 10 rows X (1046+
16) It is a conceptual diagram of a data group of columns. These data are DI, D2 . D3... is recorded, so the synchronization deviation is corrected for every second column, that is, at the beginning of every 20 bytes of data, starting with the 3-byte synchronization signal (SBI to 8B3) that indicates the beginning of the data section of the sector. A 1-byte resynchronization signal (RSI to R559) is provided.

Furthermore, in ISO-compliant optical discs, 2-7 codes that are easy to modulate and demodulate (for example, data "10" is
o” ni, “010” to “100100” ni, “0010”
' to "00100100", "11" to "1000"
, “011@” to “001000”, “0011” to “00001000”, 1000” to “oootoo”
As described above, recording data to which various data are added is modulated by encoding the data into "fl KFm", but since the code is easy to modulate, burst errors occur during fl KFm.

If synchronization is disrupted due to a random error, etc., there is a possibility that all data after the error occurrence point will be erroneously demodulated. By applying a resynchronization signal (RESYNC) using a code pattern that does not exist, even if the synchronization is disrupted once, the data can be synchronized again from the point at which the RESYNC signal is detected.

In addition, error correction of recorded data when playing data is
In many cases, so-called interleaving is applied, and correction is performed using the column direction in FIG. 3, which is different from the data recording direction, as one unit. That is, 16 bytes of parity is added to 104 bytes of user data, resulting in Long Distance Cod
e is formed, and this 16-byte parity forms 10
Errors of up to 8 bytes out of 4 bytes are corrected.

In the above-described optical disk device, when reproducing data, the L
Syndrome calculation is performed using data and parity for each Distance Code, and if the syndromes obtained as a result of the calculation are all zero, no error correction is performed, and if there is a syndrome that is not zero, the demodulated data is sent to the error correction circuit. After correcting errors in data of a predetermined sector length, errors in data correction are detected by rough calculations using CRC signals, and after confirming that there are no errors in the demodulated data of the sector. , transfers the data of the sector to the system to which the optical disk device is connected.

[Problem to be solved by the invention]

By the way, as mentioned above, with data to which 16 bytes of parity are added, errors can be corrected up to 8 bytes for each Long Distance Code, but error correction of 8 bytes takes a long time.

However, when recording data in sectors, if the recording film of the optical disc is uneven or scratched, the data will not be recorded correctly and the sector at that recording position will be determined to be an error sector. Even though no data is recorded in the data, when reproducing the data, the error correction circuit is activated by first performing an output operation to the error correction circuit even for the error sector in which no data is recorded. It is determined that the sector is an error sector only after it is determined that the error cannot be corrected. Therefore, as mentioned above, Long Distance
Optical discs using eCode have a problem in that it takes a long time to process until a sector is determined to be an error sector during data reproduction.

Also, in the address part of each sector, as shown in FIG.
It has a plurality of sets of address information consisting of a track address, a sector address, and a CRC, and when recording data, data is recorded only in sectors that can be read by the plurality of sets of addresses in order to tighten the conditions for writing. However, when reproducing data, if even one set of addresses can be read, the data in that sector is reproduced. Therefore, even if data cannot be recorded in an error sector, if the address information can be read even if it is 1, the data will be read and the error correction circuit will operate.
Although error correction is performed, since no data is actually recorded, it is determined that the sector is an error sector only after error correction becomes impossible, resulting in the problem that data reproduction processing takes a long time.

The present invention has been made to solve these problems, and aims to provide an optical disc device that reduces unnecessary error correction in an error correction circuit during data reproduction and shortens data reproduction processing time. do.

[Means to solve the problem]

The optical disc device of the present invention corrects errors in data to be recorded using an error correction circuit, adds a synchronization signal to each predetermined position of the data to be recorded, and records the data. In an optical disk device that reproduces data and corrects errors in the reproduced data using an error correction circuit, a gate generation circuit generates a detection gate for detecting a synchronization signal that should be added to the data to be reproduced; a counter that counts the number of synchronization signals of the reproduced data detected by the generated detection gate; a comparison circuit that compares the number of synchronization signals counted by the counter with the number of synchronization signals that should have been applied when recording the data; The apparatus is characterized by comprising a determination circuit that determines whether or not to output data to be reproduced to an error correction circuit based on the comparison result of the comparison circuit.

[Effect]

The optical disc device of the present invention corrects errors in data to be recorded using an error correction circuit, adds a synchronization signal to each predetermined position of the data to be recorded, and records the data. The detection gate generated by the generation circuit detects the synchronization signal added to the playback data, the counter counts the detected synchronization signal, and the number of synchronization signals counted by the counter and the number of synchronization signals added at the time of data recording are calculated. A comparison circuit compares the number of synchronization signals that should be generated, and based on the comparison result, a determination circuit determines whether or not the data to be reproduced should be output to the error correction circuit. Output to the correction circuit for error correction.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on drawings showing embodiments thereof. FIG. 1 is a block diagram showing the configuration of an optical disc device according to the present invention, and numeral 23 in the figure is an optical disc. During data recording, when the address detection circuit 28 detects the address signal of a required sector of the optical disc 23 on which data is to be recorded, the system control circuit 19 sends data of a predetermined sector length to the encoder 20, and the encoder 20 receives the given data. The encoded data is given a resynchronization signal at a predetermined position, and sent to the 2-7 modulation circuit 21.
1 modulates the given data, including a resynchronization signal, with a 2-7 code and sends it to the laser modulation circuit 22, which modulates the intensity of the laser beam to be irradiated according to the given data. and gave it to Pinkup 24,
The pickup 24 irradiates a laser beam of a specified intensity onto a predetermined position on the optical disk, thereby recording data.

FIG. 2 is a diagram showing an example of the data format of l sector in an optical disc based on ISO compliance. 136
One sector consisting of 0 bytes can be roughly divided into a 52-byte address section, which is recorded in advance during disk manufacture, and a 1274-byte data section, in which user data and the like are recorded. The address part contains a sector mark (SM) indicating the beginning of the sector, multiple sets of address data (10+ cRC) consisting of a trunk address, a sector address, etc., and an address mark (AM) indicating the beginning of the address data.
, a synchronization signal (VFO), etc. are recorded in advance.

FIG. 3 is a conceptual diagram of the data format of the data section. Data consisting of 10 rows x 120 columns and 1200 bytes is 1024 bytes of user data (DI~01
024), 12-byte control data (PI,
1 to P3.4), a 4-byte CRC, and a 160-byte parity bit (El, 1 to EI0.16).This data is stored in the optical disk 23 in the row direction. It is recorded,
Furthermore, a 3-byte synchronization signal (SRI~5
B3), while a resynchronization signal (R3I to R559) is attached to every 20 bytes of data that follows, error correction for data is performed in each row in the column direction, and 16 signals are attached to each row of data. Data errors in the row can be corrected by up to 8 bytes depending on the byte's parity bit.

Next, when reproducing data, the address detection circuit 28 detects a required address from the optical disk 23 based on the address information given from the system control circuit 19, and sends the detected address data to the waveform shaping circuit 25, where it is waveform shaped. The circuit 25 shapes the waveform of the given data to 2-71
Summer tone circuit 29. The signal is sent to the RESYNC circuit 30 and the sector mark detection circuit 31. 2-7ffit) 1 circuit 29 demodulates the data modulated by the 2-7 code and sends it to the address detection circuit 28 or error correction circuit 26, and the address detection circuit 28 detects the address of the demodulated address data. , are sent to the RESYNC detection gate generation circuit 32 and the system control circuit 19. Also,
The sector mark detection circuit 31 detects the sector mark of the given address data and sends it to the RESYNC detection gate generation circuit 32, and the RESYNC detection gate generation circuit 32 receives the sector mark and address detection circuit from the sector mark detection circuit 31. Based on the address given from the 2nd, a RESYNC detection gate is generated by identifying the address where the RESYNC signal is recorded on the optical disk 23, and the generated detection gate is RESYNC.
C4* is sent to the output circuit 30, and the generated detection gate is sent to the counter A33, and the RESYNC detection circuit 3
0 detects the RESYNC signal from the data on the optical disk 23 and converts the detected RESYNC signal to 2-7.
The signal is sent to the demodulation circuit 29 to synchronize the data, and the detected RESYNC signal is sent to the counter B34.

Counter A33 and counter B34 are given l? E
The sYNc detection gates and RESYNC signals are each counted, and the number of generated gates and the number of detection gates are sent to the comparator 35. The comparator 35 compares these and sends a signal based on the comparison result to the error sector determination circuit 27.

The error sector determination circuit 27 determines whether the sector from which data has been read is an error sector based on the signal provided from the comparator 35, and sends the determination result to the system control circuit 19. Based on the result, the data subjected to Iff modulation by the 2-7 demodulation circuit 29 is sent to the error correction circuit 26, or the sector from which the data is read is determined as an error sector, and the processing for the read data is completed.

After error correcting the supplied data, the error correction circuit 26 sends the corrected data to the system control circuit 19.
The system control circuit 19 sends correct error-corrected data from the optical disk device to the system to which the optical disk device is connected, for example, in units of sectors.

In the present invention, the number of synchronization signals detected during data reproduction is compared with the number of synchronization signals that should have been provided, using synchronization signals and resynchronization signals given during data recording, and reading is performed according to the comparison result. This is to determine whether or not to send data to the error correction circuit. For example, if the physical recording conditions of a sector in which data is recorded are poor due to a media defect, etc., it can be assumed that not only the recorded data but also the synchronization signal recorded together with the data is in a poor recording state. Therefore, the read rate of the synchronization signal during data reproduction is often low, and if the data demodulation is synchronized by the synchronization signal, if the synchronization signal is detected incorrectly, the demodulation of the read data will not be performed correctly. It won't happen. Further, regarding sectors in which a medium defect is found during data recording, not only data but also a synchronization signal is not recorded in the sector.

FIG. 4 is a time chart of output signals during data reproduction. FIG. 4 (al is the data format of the read data, the mountain) is the RE S'l N CJ0 output gate, +C) is when the RESYNC signal is detected correctly,
+dl is not detected correctly, (el is RES
This is an error signal that is output when the YNC signal is not detected correctly.

In this embodiment, the error correction circuit can correct up to 8 bytes of errors using 16 bytes of parity bits added to each row of data in the format example shown in FIG. On the other hand, if each resynchronization signal RESYNC is defective in reading, there is a possibility that the 20 bytes of data that are read out in synchronization with the RESYNC signal will be read out incorrectly, and if the reading of the 20 bytes of data becomes defective. , an error occurs in 2-byte data in each row in the column direction where error correction is performed. Therefore, if five RESYNC signals are erroneously read, there is a possibility that an error will occur in 10 bytes of data, which is beyond the correction ability of the error correction circuit.

Next, the procedure for data reproduction will be explained. Based on the address information given from the system control circuit 19, the address detection circuit 28 detects a required address from the optical disk 23, and the detected address data is waveform-shaped by the waveform shaping circuit 25 and the 2-7 demodulation circuit 29. RESY
The signal is sent to the NC circuit 30 and the sector mark detection circuit 31. The 2-7 demodulation circuit 29 demodulates the address data modulated by the 2-7 code and outputs the address data to the address detection circuit 28.
The address detection circuit 28 detects the lfi-adjusted address and sends it to the RESYNC detection gate generation circuit 32.

Further, the sector mark detection circuit 3 detects the sector mark of the given address data, sends it to the RESYNC detection gate generation circuit 32, and Rf! The 5YNC detection gate generation circuit 32 specifies the position on the optical disc 23 where the RESYNC signal is recorded based on the sector mark given from the sector mark detection circuit 31 and the address given from the address detection circuit 28, and at the specified position,
RESYN that can detect both the 3-byte synchronization signal 5YNC indicating the beginning of the data section and the resynchronization signal RESYNC
Generate a C detection gate and RESY the generated detection gate.
It is sent to the NC detection circuit 30 and the generated number of detection gates is sent to the counter A33. The RESYNC detection circuit 30 detects RESYNC from the data on the optical disk 23.
The C signal is detected and the detected RESYNC signal is sent to the 2-7 demodulation circuit 29 to synchronize the data, and the number of detected RESYNC signals is sent to the counter B34. The number of generated gates sent to the counter A33 and the number of detected gates sent to the counter B34 are calculated by the comparator 35.
If the difference between the numbers is 5 or more, there is a possibility that an error will occur in the 10 bytes of data that exceeds the 8 bytes of error correction circuit's correction capacity, so the error signal is sent to is sent to the error sector determination circuit 27.

When the error sector determination circuit 27 receives an error signal from the comparator 35, it determines the sector as an error sector and sends the determination result to the system control circuit 19. When the error sector determination circuit 27 determines that the sector is an error sector, the system control circuit 19 does not send the data demodulated by the 2-7 demodulation circuit 29 to the error correction circuit 26, and instead sends the data of the next sector to the error correction circuit 26. Shift to read processing.

If the comparison result by the comparator 35 is 4 or less, the data is read from the optical disk 23, waveform shaped by the waveform shaping circuit 25, and the waveform shaped data is passed to the 2-7 demodulation circuit 29.
The demodulated data is demodulated into encoded data such as a binary code, and the demodulated data is sent to the error correction circuit 26.

The error correction circuit 26 corrects the errors of the given data based on the ECC, detects correction errors using the CRC, and sends the correct data to the system control circuit 19, and the system control circuit 19 corrects the error corrected data. is sent from the optical disk device to the system to which the optical disk device is connected, for example, in units of sectors.

〔Effect of the invention〕

The optical disc device of the present invention generates a detection gate when reproducing data recorded by adding a synchronization signal to an optical disc, before reading the data from the optical disc and sending it to an error correction circuit that takes a relatively long time to process. The synchronization signal, which is the basis of data reading, is detected, and if the number of data that can be erroneous due to the number of synchronization signals that cannot be detected exceeds the correction ability of the error correction circuit, or if it is found to be a bad sector during data recording and the data is not recorded. If it is not, the data recorded in that sector is not sent to the error correction circuit and the next reproduction process is started, which has the excellent effect of shortening the time required for data reproduction.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of an optical disc device according to the present invention, Fig. 2 is a data format diagram of one sector, Fig. 3 is a data format diagram of the data section, and Fig. 4 is a time diagram during data reproduction. It is a chart. 19... System control circuit 23... Optical disc 2
6...Error correction circuit 27...Error sector determination circuit 28...Address detection circuit 30...RESYNC
Detection circuit 31... Sector mark detection circuit 32...
RESYNC detection gate generation circuit 33... Counter A 34... Counter B35... Comparator patent Applicant Sanyo Electric Co., Ltd. agent Patent attorney Noboru Kono Mistake 3 Figure

Claims (1)

[Claims] 1. Errors in data to be recorded are corrected by an error correction circuit, and a synchronization signal is added to each predetermined position of the data to be recorded to record the data, while recording is performed based on the synchronization signal. In an optical disk device that reproduces data and corrects errors in the reproduced data using an error correction circuit, a gate generation circuit that generates a detection gate that detects a synchronization signal that should be added to the data to be reproduced; and the gate generation circuit. a counter that counts the number of synchronization signals of the reproduced data detected by the detection gate generated by the detection gate; and a comparison circuit that compares the number of synchronization signals counted by the counter with the number of synchronization signals that should have been given at the time of data recording. , and a determination circuit that determines whether or not to output data to be reproduced to an error correction circuit based on the comparison result of the comparison circuit.