Abstract: The present invention allows the usability of a write-once recording medium to be enhanced. The write-once recording medium is provided with an ordinary recording/reproduction area, an alternate area, a first alternate-address management information area (DMA) and a second alternate-address management information area (TDMA). In addition, written/unwritten state indication information (a space bitmap) is also recorded. The second alternate-address management information area is an area allowing alternate-address management information recorded therein to be renewed by adding alternate-address management information thereto. In addition, the written/unwritten state indication information indicates whether or not data has been recorded in each data unit (cluster) on the recording medium. Thus, it is possible to correctly execute management of defects and properly implement renewal of data in the write-once recording medium.

Abstract: In step S1, the address generator generates address information composed of a sync signal which is recorded on an optical disc, address data and an error correction code for the address data, pre-encodes and supplies it to a modulator. At the same time, a carrier signal generator generates a carrier signal which is to carry the address information, and supplies it to the modulator. In step S2, the modulator makes MSK modulation of the carrier signal supplied from the carrier signal generator on the basis of the pre-encoded address information supplied from the address generator, and supplies a resultant MSK modulation signal to a wobbling unit. In step S3, the wobbling unit forms, on the optical disc, a spiral groove wobbled adaptively to the MSK modulation signal supplied from the modulator. In this optical disc, a given address can be accessed quickly and accurately.

Abstract: In step S1, the address generator generates address information composed of a sync signal which is recorded on an optical disc, address data and an error correction code for the address data, pre-encodes and supplies it to a modulator. At the same time, a carrier signal generator generates a carrier signal which is to carry the address information, and supplies it to the modulator. In step S2, the modulator makes MSK modulation of the carrier signal supplied from the carrier signal generator on the basis of the pre-encoded address information supplied from the address generator, and supplies a resultant MSK modulation signal to a wobbling unit. In step S3, the wobbling unit forms, on the optical disc, a spiral groove wobbled adaptively to the MSK modulation signal supplied from the modulator. In this optical disc, a given address can be accessed quickly and accurately.

Abstract: There is provided an optical disc having preformed thereon a spiral wobbled track as a grove and/or land along with data is to be recorded. The track is wobbled for a series of predetermined signal units each composed of an FSK information bit part based on a waveform resulted from FSK modulation of information bit and a singe-frequency part based on a waveform of a single frequency. The FSK modulation uses two different frequencies of which the one is the same as the single frequency and the other is different from the single frequency. These different frequencies are in such a relation that each of them has an even number of wobbles and an odd number of wobbles alternately in a predetermined cycle.

Abstract: A reproduction signal evaluation unit includes a pattern detection section for extracting, from a binary signal, a specific state transition pattern which has a possibility of causing a bit error; a differential metric computing section for computing a differential metric based on the binary signal of the extracted state transition pattern; an error computing section for computing an error rate predicted based on an integration value that is integrated by an integration section, a count value that is counted by a pattern count section, an integration value that is integrated by another integration section, and a count value that is counted by another pattern count section, and a standard deviation computing section for computing a standard deviation based on the computed error rate.

Abstract: A reproduction signal evaluation method evaluates the quality of a reproduction signal reproduced from an information recording medium based on a binary signal generated from the reproduction signal using a PRML signal processing system. A pattern extraction step extracts, from the binary signal, a specific state transition pattern which has the possibility of causing a bit error; a step computes a differential metric based on the binary signal; an extraction step extracts the differential metric which is not greater than a predetermined signal processing threshold; a step determines a mean value of the differential metrics which are not greater than the signal processing threshold and extracted in the extraction step; a standard deviation computing step determines a standard deviation which corresponds to an error rate predicted from the mean value; and an evaluation step evaluates a quality of the reproduction signal using the standard deviation.

Abstract: The present invention provides an information recording configuration that achieves both difficulty in reading and highly accurate reading. Highly confidential additional information such as encryption key is recorded in a groove signal. During recording of the additional information, a groove signal is recorded that has an amplitude offset setting commensurate with the bit value. During reading of the additional information, a signal R0 with no offset is estimated from a signal R1 read from the groove signal for a predetermined period, after which a difference signal C=R1?R0 is calculated and integrated for each of the predetermined periods so as to determine the direction of the amplitude offset for each period. This process achieves recording and reproduction of additional information that offers enhanced difficulty in reading and highly accurate reading at the same time.

Abstract: An information recording processing constitution realizing both readout difficulty and high-precision readout is provided. Superimposition recording of highly secret additional information such as a cryptographic key in a groove signal recorded on a disk, which superimposition recording realizes both readout difficulty and high-precision readout, can be performed. The groove signal to which a phase error corresponding to a bit value is set is recorded at a time of recording of the additional information, and at a time of readout of the additional information, the phase error of the groove signal in a predetermined section is subjected to an integrating process and the direction of the phase error of the groove signal within each section is determined. The recording and reproduction of the additional information for increasing readout difficulty and realizing high-precision readout is realized by such processes.

Abstract: A recording and reproducing area and a reproduction-only area are formed by wobbling a groove formed in a spiral fashion to form a track to be tracked on a disk. The recording and reproducing area has address information recorded by wobbling of the groove and information recorded and reproduced by phase change marks on the track formed by the groove where the address information is recorded. The reproduction-only area has prerecorded information recorded by wobbling of the groove.

Abstract: An optical recording medium provided with one or a plurality of recording layers includes an adjustment data recording area for recording therein adjustment data used for adjusting focus or spherical aberration of laser light used for recording/reproduction, the adjustment data recording area being disposed at a predetermined position on each of the one or plurality of recording layers, and a determination information recording area for recording therein determination information indicating whether or not the adjustment data has been recorded in the adjustment data recording area in each of the one or plurality of recording layers.

Abstract: A reproduction signal evaluation method evaluates the quality of a reproduction signal reproduced from an information recording medium based on a binary signal generated from the reproduction signal using a PRML signal processing system. The method includes a pattern extraction step of extracting, from the binary signal, a specific state transition pattern which has the possibility of causing a bit error; a step of computing a differential metric based on the binary signal; an extraction step of extracting the differential metric which is not greater than a predetermined signal processing threshold; a step of determining a mean value of the differential metrics which are not greater than the signal processing threshold and extracted in the extraction step; a standard deviation computing step of determining a standard deviation which corresponds to an error rate predicted from the mean value; and an evaluation step of evaluating a quality of the reproduction signal using the standard deviation.

Abstract: An optical recording medium provided with one or a plurality of recording layers includes an adjustment data recording area for recording therein adjustment data used for adjusting focus or spherical aberration of laser light used for recording/reproduction, the adjustment data recording area being disposed at a predetermined position on each of the one or plurality of recording layers, and a determination information recording area for recording therein determination information indicating whether or not the adjustment data has been recorded in the adjustment data recording area in each of the one or plurality of recording layers.

Abstract: A recording and reproducing area and a reproduction-only area are formed by wobbling a groove formed in a spiral fashion to form a track to be tracked on a disk. The recording and reproducing area has address information recorded by wobbling of the groove and information recorded and reproduced by phase change marks on the track formed by the groove where the address information is recorded. The reproduction-only area has prerecorded information recorded by wobbling of the groove.

Abstract: The present invention allows the usability of a write-once recording medium to be enhanced. The write-once recording medium is provided with an ordinary recording/reproduction area, an alternate area, a first alternate-address management information area (DMA) and a second alternate-address management information area (TDMA). In addition, written/unwritten state indication information (a space bitmap) is also recorded. The second alternate-address management information area is an area allowing alternate-address management information recorded therein to be renewed by adding alternate-address management information thereto. In addition, the written/unwritten state indication information indicates whether or not data has been recorded in each data unit (cluster) on the recording medium. Thus, it is possible to correctly execute management of defects and properly implement renewal of data in the write-once recording medium.

Abstract: Address information that has been error correction encoded is recorded on a second version of a recording medium after being transformed such that such that the address decoding cannot be performed by a playback device that is not compatible with the second version of the recording medium. The address decoding for the second version of the recording medium cannot be performed by the incompatible playback device (for example, a playback device that was manufactured to be compatible only with a first version of the recording medium). In other words, in the playback device that is not compatible with the second version of the recording medium, a state is created in which address errors cannot be corrected, so access is impossible (recording and playback are impossible).

Abstract: The present invention aims to provide a reproduced signal evaluation method and a write adjustment method for offering a Blu-ray disc having a large storage capacity with excellent media compatibility. An evaluation index L-SEAT is calculated through signed addition using a Euclidean distance difference calculated from at least one of target signals in which a focused edge is shifted to the right and left, and the quality of the reproduced signal is evaluated based on the evaluation index. Write condition adjustment using the index enables write adjustment not depending on SNR and achieving high adjustment accuracy.

Abstract: A recording and reproducing area and a reproduction-only area are formed by wobbling a groove formed in a spiral fashion to form a track to be tracked on a disk. The recording and reproducing area has address information recorded by wobbling of the groove and information recorded and reproduced by phase change marks on the track formed by the groove where the address information is recorded. The reproduction-only area has prerecorded information recorded by wobbling of the groove.

Abstract: The present invention allows the usability of a write-once recording medium to be enhanced. The write-once recording medium is provided with an ordinary recording/reproduction area, an alternate area, a first alternate-address management information area (DMA) and a second alternate-address management information area (TDMA). In addition, written/unwritten state indication information (a space bitmap) is also recorded. The second alternate-address management information area is an area allowing alternate-address management information recorded therein to be renewed by adding alternate-address management information thereto. In addition, the written/unwritten state indication information indicates whether or not data has been recorded in each data unit (cluster) on the recording medium. Thus, it is possible to correctly execute management of defects and properly implement renewal of data in the write-once recording medium.

Abstract: In step S1, the address generator generates address information composed of a sync signal which is recorded on an optical disc, address data and an error correction code for the address data, pre-encodes and supplies it to a modulator. At the same time, a carrier signal generator generates a carrier signal which is to carry the address information, and supplies it to the modulator. In step S2, the modulator makes MSK modulation of the carrier signal supplied from the carrier signal generator on the basis of the pre-encoded address information supplied from the address generator, and supplies a resultant MSK modulation signal to a wobbling unit. In step S3, the wobbling unit forms, on the optical disc, a spiral groove wobbled adaptively to the MSK modulation signal supplied from the modulator. In this optical disc, a given address can be accessed quickly and accurately.

Abstract: There is provided an optical disc having preformed thereon a spiral wobbled track as a grove and/or land along with data is to be recorded. The track is wobbled for a series of predetermined signal units each composed of an FSK information bit part based on a waveform resulted from FSK modulation of information bit and a singe-frequency part based on a waveform of a single frequency. The FSK modulation uses two different frequencies of which the one is the same as the single frequency and the other is different from the single frequency. These different frequencies are in such a relation that each of them has an even number of wobbles and an odd number of wobbles alternately in a predetermined cycle.