Victor Company of Japan, Limited

Tsuyoshi Oki

Atsushi Hayami

Toshio Kuroiwa

A pattern of an input sync signal is compared with sub patterns in a first sync pattern. The sub patterns in the first sync pattern are equal to the patterns of true sync signals, respectively. When the pattern of the input sync signal agrees with none of the sub patterns in the first sync pattern, the pattern of the input sync signal is compared with sub patterns in a second sync pattern. The sub patterns in the second sync pattern have temporal fluctuations with respect to the patterns of the true sync signals. Each of the sub patterns in the second sync pattern is assigned to only one of the true sync signals. It is determined that a sync signal is detected when the pattern of the input sync signal agrees with one of the sub patterns in the first and second sync patterns.

Method of detecting sync signals

A method and apparatus for detecting information recorded as a phase-modulated wobble along a track of an optical disk, whereby a reference phase section is recorded with wobble having a predetermined reference phase and whereby respective polarities of phase integration values obtained by synchronous detection of phase-modulated unit sections following the reference phase section, in a playback wobble signal, are compared with the polarity of a reference phase integration value obtained for the reference phase section, to thereby detect respective bit states expressed by the phase-modulated unit sections.

Wobble information detection method and wobble information detection apparatus for optical recording medium

First and second synchronous words having respective numbers of times of inversion different from each other in NRZI conversion are generated in a synchronous word generation portion, and first and second code word series data are generated by arranging code word data generated making reference to a run-length coding table after these two synchronous words. With respect to the first and second code word series data, DSV calculation results stored in two DSV calculation peak value memories corresponding to these data are compared with each other by a peak value comparison portion. Based on a comparison result, the code word series data having a smaller direct-current component generated in NRZI conversion is selected.

Digital signal modulation method, digital signal modulation apparatus, encoding method, encoding apparatus, storage medium, transmission apparatus and program

There is disclosed a recording method for performing a DSV control while recording a recording signal generated by inserting a synchronous signal for decoding reproduction data into every predetermined number of code words in a code word string satisfying a predetermined run length restriction rule and to be outputted into a recording medium, when a plurality of coding tables are used to convert an input data word of p-bits to a code word of q-bits (q&#x3e;p), and the code word string obtained by directly coupling the code words is recorded and reproduced in a recording medium such as an optical disk and magnetic disk, or transmitted via a transmitting portion, wherein the p-bits are 8 bits, the q-bits are 15 bits, and the predetermined run length restriction rule stipulates that a minimum run length of the signal obtained by NRZI-converting the code word excluding the synchronous signal is 3T, and a maximum run length is any one of 11T, 12T, 13T, and 14T.

Recording method, recording apparatus, transmitting apparatus, reproducing method, reproducing apparatus, receiving apparatus, recording medium, and transmission medium

There is disclosed a synchronous signal generating method, recording apparatus, transmitting apparatus, recording medium and transmission medium in which a plurality of coding tables is used to convert an input data word of p-bits to a code word of q-bits (q&#x3e;p), and a code word string obtained by directly coupling the code words is recorded and reproduced in a recording medium such as an optical disk and magnetic disk, or transmitted via a transmitting portion. A synchronous frame consists of a synchronous signal and the cord word string satisfying restriction on minimum run length and maximum run length. The synchronous signal is separable from the code word string satisfying a predetermined run length restriction rule, and is constituted with a specific code for identifying its position in one sector, and a synchronous pattern consisting of a first bit pattern having a run length longer than the maximum run length of the predetermined run length restriction rule by 1T or more, and a following second bit pattern having a run length longer than the minimum run length.

Synchronous signal generating method, recording apparatus, transmitting apparatus, recording medium, and transmission medium

A data estimating circuit outputs estimation data which estimates input data at a time earlier by a predetermined bit cycle than the input data based on decoded data series outputted from a path memory. A target value computing circuit corrects the target value with a difference between the estimation data and input data as a target value error and outputs obtained plural first target values to a branchmetric operating circuit as plural target values. Because the branchmetric operating circuit can conduct branchmetric operation based on plural first target values near plural averages having the highest incidence (having peaks in histogram), decoding performance can be improved more as compared to using fixed target values.

Viterbi decoder and Viterbi decoding method

There is disclosed a modulation method in which a four bit unit of a plurality of continuous input data words is encoded into a six bit unit of a plurality of continuous output code words by referring to a plurality of coding tables including output code words corresponding to input data words, and coding table designation information in which a coding table for use in encoding the next input data word is designated. The plurality of coding tables includes at least a first coding table and a second coding table, and first and second signals respectively obtained by subjecting a first output code word of said first coding table corresponding to a predetermined input data word and a second output code word of said second coding table corresponding to said predetermined input data word to NRZI modulation are reverse to each other in polarity. Further, in particular, two redundant bits are inserted into the plurality of continuous output code words for each predetermined number of corresponding data words. Even with such redundant bits, a DSV control is performed in any section, k satisfies 9 in a (1, k) RLL rule, and a repetition frequency of a minimum run is limited.

Modulation method, modulation apparatus, demodulation method, demodulation apparatus, information recording medium, information transmission method, and information transmission apparatus

A coding table portion includes six coding tables each storing a code word and status information indicating a coding table for use in modulating a next input data word in order to obtain a next code word which satisfies a predetermined run length restriction rule even if the next code word is coupled directly with the preceding code word, corresponding to each input data word. In the coding table portion, the code words and status informations allocated corresponding to input data words of a number set up preliminarily in succession from the highest appearance frequency to a lower one in one or more coding tables of the plural coding tables are replaced with code words having smaller RDSs and status informations allocated corresponding to other input data words in the same coding table. Consequently, the input data word is modulated using the six coding tables.

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Kanagawa-ken, Japan

Tsuyoshi Oki