Hitachi, Ltd.

Other

Hitachi Video and Information System, Inc.

Yasuyuki Ito

Yoshiju Watanabe

Naoki Satoh

Terumi Takashi

Mikio Suzuki

Hideaki Maeda

Akihiko Hirano

Data synchronization detection is provided between data identification and code demodulation in a data reproduction system, which performs data synchronization detection using code-modulated data. A specified bit pattern generated in a data codeword is calculated in each phase (bit), using a specified bit sequence pattern that is not generated in a specified phase of the data codeword. For example, a specified bit sequence pattern is generated only in a specified phase of the codeword. The positions of the data codeword partitions are thereby identified. Scrambling is then applied to the write data as required in order to ensure accurate synchronization detection.

Data synchronization detection device, information recording device, information reproduction device, information recording format, signal processing device, information recording and reproducing device, and information recording medium

Data synchronization detection is provided between data identification and code demodulation in a data reproduction system, which performs data synchronization detection using code-modulated data. A specified bit pattern generated in a data codeword is calculated in each phase (bit), using a specified bit sequence pattern that is not generated in a specified phase of the data codeword. For example, a specified bit sequence pattern is generated only in a specified phase of the codeword). The positions of the data codeword partitions are thereby identified. Scrambling is then applied to the write data as required in order to ensure accurate synchronization detection.

Data synchronization detection method, information recording method, and information reproduction method

The present invention enables recovery of data reading, even when thermal asperities or defective media will make it impossible to increase the number of retries or to read the data, occur in the AGC/PLL part. In a device for writing and reading information, when an error occurs in the region of the recording media where the AGC/PLL signal is written, and if that information is written continuously to several sectors, then data reading is performed by using the AGC/PLL of the following sector, without performing a retry, or by performing a minimum number of retries.

Signal processing technique for preventing delay in read time from retry operations

Data byte errors are detected by a comparator and classified into errors for respective interleaves, and the classified errors are counted by counters in an error count block. Further, at the time one sector has been read, comparators compare the counted values for the respective interleaves with an interleave threshold to detect whether nor not there are interleaves which have a number of errors exceeding the interleave threshold, and the detected results are counted by an error count block. The frequency of retries after an ECC is predicted from the counted value on the error count block and the total number of read sectors.

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Chigasaki, Japan

Yasuyuki Ito