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: The present invention is to realize a proper inner zone layout in a quadruple-layer disk. A test area is provided in the inner zone (inner circumference side area) in each of recording layers. If two test areas closer to the outer circumference, of four test areas, are defined as a first pair and two test areas closer to the inner circumference are defined as a second pair, the test areas of the first pair and the test areas of the second pair are so disposed as to be prevented from overlapping with each other in the layer direction. Two test areas of the first pair have the same consumption direction of the test area, and are so disposed that the areas to be used next hardly overlap with each other in the layer direction. Two test areas of the second pair have the same consumption direction of the test area opposite to the consumption direction of the test area in the first pair, and are so disposed that the areas to be used next hardly overlap with each other in the layer direction.

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: An optical information recording medium operated by CAV or zone CAV, wherein a groove that wobbles is formed in advance, and information is recorded in the groove and a land adjacent to the groove, an address is recorded by a wobble signal of the groove, the groove is alternately provided with a first section recording an address N by the wobble signal, and a second section recording an address (N?1) or (N+1) by the wobble signal, in two groove tracks sandwiching a land track, the first section of one of the groove tracks matches the second section of the other of the groove tracks, and an address of the groove is read from the first section, and an address of the land is read from the first and the second sections located on both sides of the land track, and recording a same address.

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: 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: 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: An optical information recording medium operated by CAV or zone CAV, wherein a groove that wobbles is formed in advance, and information is recorded in the groove and a land adjacent to the groove, an address is recorded by a wobble signal of the groove, the groove is alternately provided with a first section recording an address N by the wobble signal, and a second section recording an address (N?1) or (N+1) by the wobble signal, in two groove tracks sandwiching a land track, the first section of one of the groove tracks matches the second section of the other of the groove tracks, and an address of the groove is read from the first section, and an address of the land is read from the first and the second sections located on both sides of the land track, and recording a same address.

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: 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: A disk recording medium which can implement a recording method having a high degree of reliability for additional information is disclosed. The disk recording medium has a recording and reproduction region into and from which first data can be recorded and reproduced in accordance with a rewritable or write-once-read-many recording method and from which second data recorded in the form of wobbling of a groove can be reproduced. The second data includes address information and additional information. The additional information of the second data is coded in accordance with a first error correction method, and the coded additional information and the address information are recorded in a state coded in accordance with a second error correction method.

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 is to realize a proper inner zone layout in a quadruple-layer disk. A test area is provided in the inner zone (inner circumference side area) in each of recording layers. If two test areas closer to the outer circumference, of four test areas, are defined as a first pair and two test areas closer to the inner circumference are defined as a second pair, the test areas of the first pair and the test areas of the second pair are so disposed as to be prevented from overlapping with each other in the layer direction. Two test areas of the first pair have the same consumption direction of the test area, and are so disposed that the areas to be used next hardly overlap with each other in the layer direction. Two test areas of the second pair have the same consumption direction of the test area opposite to the consumption direction of the test area in the first pair, and are so disposed that the areas to be used next hardly overlap with each other in the layer direction.

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: 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 is to realize a proper inner zone layout in an optical disk having at least three layers. A test area is provided in the inner zone (inner circumference side area) in each of recording layers. The test areas of each layer are so disposed as to be prevented from overlapping with each other in the layer direction. Furthermore, the number of management information recording/reproduction areas overlapping with the test area in the layer direction at a position closer to the laser-incident surface than this test area is set equal to or smaller than one in each test area of each recording layer. The management information recording/reproduction areas are each so disposed as to be prevented from overlapping with the test areas in the respective recording layers in the layer direction on the disk substrate side of the test areas.

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: A ROM disk having a block data format provided with linking areas as with a rewritable disk. Main data recorded in a main data area and linking data recorded in a linking area in each block are scrambled by identical scrambling data. The scrambling data is generated by a random sequence using address information of the block as an initial value.

Abstract: To record specific information to a disk-shaped record medium and reproduce the recorded specific information without any influence on the error correction capability. Copy protection information (CPID) having an error correction code appended thereto, shuffled and otherwise treated is sent as a CPID bit block to an EDC rewrite circuit (14). The EDC rewrite circuit (14) rewrites an error detection code appended to user data in each sector in accordance with bit information in the CPID bit block. Thereafter, the data in each sector is scrambled, and an ECC block including a plurality of sectors is modulated with an error correction code and sync signal appended thereto. The modulated signal is recorded in a reserve area of a lead-in area of the disk-shaped record medium. During reproduction, CPID is restored based on the result of error detection of each sector.