JPH03278374A - Format decoder - Google Patents

Abstract

PURPOSE:To obtain format information with high accuracy from an optical disk with a large number of flaws by providing a circuit which outputs a discrimination result by discriminating a track address signal by decision by majority, and a circuit which outputs the discrimination result by discriminating the coincidence of the track address signal included in a signal from a decoder. CONSTITUTION:A majority circuit 19 outputs a majority signal when the coincidence of two track addresses out of track addresses recorded for three times on the optical disk, and also, a coincidence circuit 20 outputs a coincidence signal when the coincidence of all the track addresses is obtained, thereby, a microcomputer can obtain track address information with high accuracy, Also, by employing such configuration, the microcomputer can use the majority signal from the majority circuit 19 separately from the coincidence signal from the coincidence circuit 20 in address decision in a seek operation and that in a write operation, respectively. Thereby, it is possible to obtain the format information with high accuracy from the optical disk with a large number of flaws.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a format decoding device used in a device for driving a sample format optical disk.

Conventional technology Generally, an 18-hide ID as shown in Figure 2 is placed at the beginning of each sector of a sample format optical disc.
This ID field contains 2 bytes of servo byte, 1 byte of synchronization signal (SYNC), 1 byte of sector address (SEC), 1 byte of track upper address (TRKH), and 1 byte of track upper address (TRKH). Track lower address (TRKL), 1-byte track lower address complement) (TRKL) (!:, 1-byte upper track address complement) (TR, KH), and 1
Byte track lower address combination (TRK
L) and a 9-byte reserve area (Re5erve) for laser power adjustment, etc.

Conventionally, a format decoding device in a device that drives a sample format optical disk extracts the servo clock recorded on the optical disk and performs a PLL (
Phase Locked Loop) to generate a data clock, and based on this clock 4/15
The code is decoded and the sector address (SEC), track address (TRKH+RTKL), track combination (I) address (TRKH + first RTKL), track combination (II) address ( TRKH (the last RTKL) was read, and the read track address was determined by majority vote whether it was correct or not, and the address of the optical disk was detected by assuming that the sector address was correct without making any determination. .

Problems to be Solved by the Invention However, the conventional format decoding device described above detects whether or not the read track address is correct by majority vote, and regards the value of the sector address as correct without making any determination. There is a problem in that the formant of an optical disc with many defects cannot be read in order to detect the address of the optical disc.

SUMMARY OF THE INVENTION In view of the above conventional problems, it is an object of the present invention to provide a format decoding device that can obtain highly accurate format information from an optical disc with many defects.

Means for Solving the Problems In order to achieve the above object, the present invention determines and outputs a sector address based on a sector address signal included in a data clock from a PLL circuit and a signal from a decoder,
a circuit that predicts and outputs the current sector address based on the previous sector address when it cannot be determined;
A circuit that determines the track address signal included in the signal from the decoder by majority vote and outputs the determination result, and a circuit that determines whether the track address signal included in the signal from the decoder matches and outputs the determination result. It is equipped with the following.

Effect of the Invention With the above configuration, the present invention can obtain highly accurate sector address information from an optical disk with many defects in order to predict and output sector addresses. Therefore, highly accurate track address information can be obtained from an optical disk with many defects, and therefore highly accurate format information can be obtained from an optical disk with many defects.

EXAMPLES Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a format decoding device according to the present invention.

In FIG. 1, 11 extracts the servo clock recorded on the optical disk of the sample format method as shown in FIG. 2, generates and outputs a data clock, and outputs an unlock detection signal when the PLL is still unlocked. The output PLL circuit 12 performs a 4/15 code decoding of the data recorded on the optical disk (RF multiplied signal) to generate a binary signal based on the data clock from the PLL circuit 11, as shown in FIG. This is a 4/15 decoder that outputs a parallel signal decoded into .

Reference numeral 13 denotes a sector counter that counts the current sector of the optical disk using a data clock from a PLL circuit. Micro combinator (not shown)
The value given from the path 23 and the interface circuit 22 is preset.

14 is a sector register in which the value of a sector mark signal that is included in the output signal of the 4/15 decoder 12 and indicates the beginning of each sector of the optical disc is set; 15 is a track that is included in the output signal of the 4/15 decoder 12; Address (TR
16 is a trunk complement register (1) for storing track address combination (1) (TRK) included in the output signal of the 4/15 decoder 12; (1) register 17 is a 4/15 This is a track combination (n) register that stores a track address combination (■) (TRK) included in the output signal of the decoder 12.

18 stores the previous value from the sector register 14, compares this value with the current value from the sector register 14, outputs the current value if they match, and outputs one if different. It is a judgment circuit that outputs a predicted value from the previous value,
This judgment circuit 8 also constantly monitors the value of the sector counter 13 and outputs a predicted value even when no signal is input from the sector register 14 at the beginning of a sector.

19 are track register 15, track complement (1) register 16, and track complement (1)
(II) The track address (TRK1TRKx2) recorded three times on the optical disc is determined by the output signal of the register 17.
20 is a coincidence circuit that outputs a coincidence signal when all of the track addresses recorded three times on this optical disk are the same. be.

The majority signal from the majority circuit 19 is output to the microcomputer via the interface circuit 22 and the bus 23 and is used when seeking a track on the optical disk, and the coincidence signal from the -number circuit 20 is output to the microcomputer via the interface circuit 22 and the bus 23. It is used for data protection etc. when data is output to a computer and recorded on an optical disc.

Reference numeral 21 denotes a timing generation circuit that outputs basic timing signals necessary for each of the circuits 11 to 20 using the servo clock and the data clock from the PLL circuit 11.

Incidentally, microcomputers still have PLL circuit 11.
In addition to the unlock detection signal from , various error signals are inputted via the interface circuit 22 and bus 23 .

In the above configuration, the determination circuit 18 stores the previous value from the sector register 14, compares this value with the current value from the sector register 14, and predicts from the previous value if different. It also constantly monitors the value of the sector counter 13 and registers the value of the sector register 14 at the beginning of the sector.
By outputting a predicted value even when no signal is input from the optical pickup, the microconbeater can obtain highly accurate sector address information without using a sensor for detecting the position of the optical pickup.

In addition, since the current sector of the optical disk is counted by the data clock from the PLL circuit 11, the sector address can be predicted based on the predicted value. Therefore, if the sector address cannot be read due to a defect in the optical disk It is also possible to obtain highly accurate sector address information.

Furthermore, the majority decision circuit 19 outputs a majority decision signal when two of the track addresses recorded three times on the optical disk are the same, and the - number circuit 20 outputs a majority decision signal when all the track addresses are the same. In order to output the signal, the microcomputer can obtain highly accurate track address information.

Further, according to the above embodiment, the microconverter uses the majority signal from the majority decision circuit 9 and the coincidence signal from the coincidence circuit 20 to use each signal separately for address determination at seek time and address determination at write time. be able to.

Further, each of the circuits 11 to 22 described above can be constructed using an LSI, and therefore can be incorporated into an optical disc device or the like as a miniaturized device.

As described in detail, the present invention determines and outputs a sector address using a data clock from a PLL circuit and a sector address signal included in a signal from a decoder, and when the sector address cannot be determined, the previous sector address is A circuit that predicts and outputs the current sector address based on the address, a circuit that discriminates the track address signal included in the signal from the decoder by majority vote and outputs the discrimination result, and a track address signal included in the signal from the decoder 4. Since the present invention includes a circuit that determines whether or not they match and outputs the determination result, highly accurate format information can be obtained from an optical disc with many defects.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a format decoding device according to the present invention, and FIG. 2 is an explanatory diagram showing an ID section of each sector of a sample format optical disc. 11... PLL circuit, 12. 4/15 decoder,
13... Sector counter, 14... Sector register, 15... Track register, 16... Track completion (1) register, 17... Trunk completion (II) register, 18... Sector determination Circuit, 19... Multi-order circuit, 20... Coincidence circuit, 2
DESCRIPTION OF SYMBOLS 1...Timing generation circuit, 22 Interface circuit, 23 Microcomputer bus.

Claims (2)

[Claims] (1) Extract the servo clock recorded on the recording medium,
a PLL circuit that generates and outputs a data clock; a decoder that decodes a reproduction signal of data recorded on an optical disk based on the data clock from the PLL circuit; A circuit that determines and outputs a sector address based on a sector address signal included in the signal, and predicts and outputs the current sector address based on the previous sector address if the sector address cannot be determined, and a circuit that is included in the signal from the decoder. The track address signal is determined by majority vote,
A format decoding device comprising: a circuit that outputs a determination result; and a circuit that determines whether track address signals included in signals from the decoder match and outputs the determination result. (2) The format decoding device according to claim 1, further comprising a circuit for outputting the determination results of the sector address and track address to a microcomputer of the optical disc device.