Abstract: A recording/reproduction apparatus, comprising a first recording section for recording test information onto a medium using at least one recording power, a reproduction section for reproducing at least one test signal indicating the test information from the medium, and a second recording section for recording information onto the medium using one of the at least one recording power. The reproduction section comprises a decoding section for performing maximum likelihood decoding of the at least one test signal and generating at least one binary signal indicating a result of the maximum likelihood decoding, a calculation section for calculating a reliability of the result of the maximum likelihood decoding based on the at least one test signal and the at least one binary signal, and an adjustment section for adjusting a recording power for recording the information onto the medium to the one recording power based on the reliability.

Abstract: An address format for appropriately controlling the recording linear density and the number of information recording layers is provided in order to increase the recording capacity of an information recording medium such as an optical disc or the like in a range in which a necessary S/N ratio can be guaranteed. An optical disc includes an information recording layer having a concentric or spiral track, and has a format for describing a track address, which is pre-recorded on the track or is to be added to data that is to be recorded on the information recording layer. The format includes layer information regarding the information recording layer and address information regarding the track address.

Abstract: A big pattern for a run-in area which allows data reproduction to be performed stably even when the recording density of an optical disc is increased is provided. An optical disc according to the present invention includes tracks, each of which divided into a plurality of recording blocks. Each of the plurality of blocks includes a run-in area and a data area. In the run-in area, a prescribed run-in bit pattern is recordable; and in the data area, bit patterns having a plurality of bit lengths obtained by modulating data as a recording target in accordance with a prescribed modulation rule are recordable. In this optical disc, at least one of spatial frequencies corresponding to the bit patterns having the plurality of bit lengths is higher than a cutoff frequency. The run-in bit pattern recordable in the run-in area includes the bit patterns having the plurality of bit lengths, from which the bit pattern corresponding to the frequency higher than the OTF cutoff frequency has been excluded.

Abstract: A method for rating an information recording medium according to the present invention includes the steps of: receiving a digital read signal, which has been generated based on an analog read signal representing information that has been read from the information recording medium, and shaping the waveform of the digital read signal; subjecting the shaped digital read signal to maximum likelihood decoding, thereby generating a binarized signal showing a result of the maximum likelihood decoding; and calculating the quality of the digital read signal based on the shaped digital read signal and the binarized signal. If the quality of the read signal is calculated by a PRML method in which a number of zero-cross portions are included in a merging path of a minimum difference metric, the quality is calculated by using only a state transition pattern in which only one zero-cross portion is included in a merging path of a non-minimum difference metric.

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 position detection device, a position detection method, a position detection control device, a position detection control method, a position detection control program, an access authentication device, an access authentication method, an access authentication control device, an access authentication control method, an access authentication control program, an information storage device, and an optical disk are provided, all of which make it possible to prevent illegal copying of the information recorded in a recording medium. An information recording/playback device detects the position on an optical disk of an RFID tag provided to the optical disk, and writes the detected position on the optical disk of the RFID tag into the RFID tag as the position information.

Abstract: A waveform shaping portion receives a digital reproduced signal generated from an analog reproduced signal reproduced from an information recording medium and shapes the waveform of the digital reproduced signal. A maximum likelihood decoding portion applies maximum likelihood decoding to the digital reproduced signal in the shaped waveform and generates a binarized signal indicating the result of the maximum likelihood decoding. A phase detection portion extracts, during the maximum likelihood decoding, a phase error using state transition patterns having only a single zero cross point among differential metrics at a plurality of merging points at which a set of paths branched from a given state merges. A synchronization detection portion generates a reproduction clock signal using the phase error that has been detected and brings the digital reproduced signal into synchronization with the reproduction clock signal that has been generated.

Abstract: An address format for appropriately controlling the recording linear density and the number of information recording layers is provided in order to increase the recording capacity of an information recording medium such as an optical disc or the like in a range in which a necessary S/N ratio can be guaranteed. An optical disc includes an information recording layer having a concentric or spiral track, and has a format for describing a track address, which is pre-recorded on the track or is to be added to data that is to be recorded on the information recording layer. The format includes layer information regarding the information recording layer and address information regarding the track address.

Abstract: A big pattern for a run-in area which allows data reproduction to be performed stably even when the recording density of an optical disc is increased is provided. An optical disc according to the present invention includes tracks, each of which divided into a plurality of recording blocks. Each of the plurality of blocks includes a run-in area and a data area. In the run-in area, a prescribed run-in bit pattern is recordable; and in the data area, bit patterns having a plurality of bit lengths obtained by modulating data as a recording target in accordance with a prescribed modulation rule are recordable. In this optical disc, at least one of spatial frequencies corresponding to the bit patterns having the plurality of bit lengths is higher than a cutoff frequency. The run-in bit pattern recordable in the run-in area includes the bit patterns having the plurality of bit lengths, from which the bit pattern corresponding to the frequency higher than the OTF cutoff frequency has been excluded.

Abstract: An information processing device for processing specific information recorded to a recording medium that has a characteristic identification unit and a processing unit. The characteristic identification unit identifies the reflection characteristic of the recording medium. The processing unit processes the specific information recorded to the recording medium according to the identified reflection characteristic. The reflection characteristic is either a first characteristic such that the reflectance of light reflected by a recorded region of the recording medium (referred to as first reflectance) is greater than the reflectance of light reflected by an unrecorded region of the recording medium (referred to as second reflectance), or a second characteristic such that the first reflectance is less than the second reflectance.

Abstract: A reproduction signal evaluation method according to the present invention includes a step of generating a binary signal from an information recording medium on which a data sequence including marks and spaces in combination is recordable, using a PRML signal processing method from a signal obtained by reproducing the data sequence; and a differential calculation step of calculating a differential metric using a first state transition path having a maximum likelihood and a second state transition path having a second maximum likelihood, and a reproduction signal, the first state transition path and the second state transition path being obtained based on the binary signal.

Abstract: In an optical disc, a track on which data is recordable is divided into a plurality of blocks, and each block includes L pieces of sub blocks. On each sub block, M-bit first digital information specifying a block address of a block including the each sub block and N-bit second digital information capable of representing a numerical value equal to or larger than L are recorded.

Abstract: A big pattern for a run-in area which allows data reproduction to be performed stably even when the recording density of an optical disc is increased is provided. An optical disc according to the present invention includes tracks, each of which divided into a plurality of recording blocks. Each of the plurality of blocks includes a run-in area and a data area. In the run-in area, a prescribed run-in bit pattern is recordable; and in the data area, bit patterns having a plurality of bit lengths obtained by modulating data as a recording target in accordance with a prescribed modulation rule are recordable. In this optical disc, at least one of spatial frequencies corresponding to the bit patterns having the plurality of bit lengths is higher than a cutoff frequency. The run-in bit pattern recordable in the run-in area includes the bit patterns having the plurality of bit lengths, from which the bit pattern corresponding to the frequency higher than the OTF cutoff frequency has been excluded.

Abstract: A reproduction signal evaluation unit has: 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: An optical head 12 reproduces information recorded on an optical disc 11, a BCA detector 21 and a medium discriminating circuit 22 acquire waveform distortion information for specifying a waveform distortion of a reproduction signal reproduced by the optical head 12, and a variable waveform equalizer 16 changes a parameter used in a distortion reduction processing for reducing the waveform distortion of the reproduction signal based on the waveform distortion information.

Abstract: A clock signal generator according to the present invention includes: a wobble phase error detecting section for detecting a wobble phase error that is a difference in phase between a wobble signal, representing a wobbled shape of a track on an optical disk medium, and a clock signal; a data phase error detecting section for detecting a data phase error that is a difference in phase between a data signal, representing data that has been written on the optical disk medium, and the clock signal; a frequency control section for generating a frequency control signal to control the frequency of the clock signal based on the wobble phase error and the data phase error; and a clock oscillation section for generating the clock signal with its frequency controlled in accordance with the frequency control signal.

Abstract: A reproduction signal evaluation method according to the present invention includes a step of generating a binary signal from an information recording medium on which a data sequence including marks and spaces in combination is recordable, using a PRML signal processing method from a signal obtained by reproducing the data sequence; and a differential calculation step of calculating a differential metric using a first state transition path having a maximum likelihood and a second state transition path having a second maximum likelihood, and a reproduction signal, the first state transition path and the second state transition path being obtained based on the binary signal.

Abstract: The present invention has an object of evaluating a recording and reproduction signal quality of a high density information recording medium by providing an index representing, in a detection signal including a plurality of pieces of edge shift information, how each edge is shifted.

Abstract: A recording/reproduction apparatus, comprising a first recording section for recording test information onto a medium using at least one recording power, a reproduction section for reproducing at least one test signal indicating the test information from the medium, and a second recording section for recording information onto the medium using one of the at least one recording power. The reproduction section comprises a decoding section for performing maximum likelihood decoding of the at least one test signal and generating at least one binary signal indicating a result of the maximum likelihood decoding, a calculation section for calculating a reliability of the result of the maximum likelihood decoding based on the at least one test signal and the at least one binary signal, and an adjustment section for adjusting a recording power for recording the information onto the medium to the one recording power based on the reliability.

Abstract: A most probable path is selected from a number n (where n?2) of paths of state transitions occurring from a first state Sk?j (where k?3 and j?2) at a time k?j into a second state Sk at a time k. The method includes the steps of detecting predetermined combinations of the first and second states Sk?j and Sk defining the n probable paths in a predetermined period j between the times k?j and k, and evaluating the reliability of a read signal, decoded in the period j, by |Pa?Pb|. Pa and Pb indicate the probabilities of state transition of first and second state transition paths in the period j. The first and second state transition paths are estimated to be the most probable and the second most probable, respectively, among the n probable paths defined by the combinations detected.