Abstract: An optical medium reproduction device includes: a detection unit configured to form detection signals of respective channels by dividing a cross-section of a beam returning from the optical medium into a plurality of regions and performing division into at least one channel corresponding to the region at an outer side in a radial direction, at least one channel corresponding to the region that is different in position in a tangential direction, and a channel corresponding to the other regions, and, in a case of forming the detection signals of the channels, form the detection signal of at least one of the channels by weighting and adding a signal in a predetermined region among the plurality of regions; a multi-input equalizer unit configured to include a plurality of equalizer units to which the respective detection signals of the plurality of channels are supplied, and configured to form an equalized signal on the basis of the detection signals of the plurality of channels; and a binarization unit configure

Abstract: The present disclosure relates to a reproduction apparatus. The reproduction apparatus may comprise an optical filter and electric filters. The optical filter may be configured to provide electrical signals corresponding to regions of an optical beam returning from an optical medium, the optical beam being incident on the optical filter, the regions of the optical beam corresponding to different bands in a line density direction and/or a track density direction. The electric filters may be configured to provide outputs based, at least in part, on the electrical signals provided by the optical filter, wherein the reproduction apparatus is configured to obtain a reproduced signal by combining the outputs of the electric filters.

Abstract: Provided is a signal quality evaluation apparatus, including an error pattern detection unit to which binarized data obtained by performing a PRML decoding process on a reproduced signal of bit information by partial response equalization and maximum likelihood decoding is input, the error pattern detection unit configured to detect at least one specific error pattern that is a bit pattern that is longer than a constraint length of the PRML decoding process, a metric difference calculation unit configured to calculate a metric difference of the at least one specific error pattern that has been detected by the error pattern detection unit, and an index value generation unit configured to generate an index value of a reproduced signal quality by using a distribution of the metric difference obtained by the metric difference calculation unit.

Abstract: There is provided an optical medium reproduction device that optically reproduces an optical medium in which a plurality of tracks are provided, the optical medium reproduction device including: a detection unit configured to divide a cross-section of a beam returning from the optical medium into at least one channel corresponding to an outer region in a radial direction, at least one channel corresponding to a region that is different in position in a tangential direction, and a channel corresponding to the other region, and form detection signals of the channels; a multi-input equalizer unit including a plurality of equalizer units to which the detection signals of the plurality of channels are supplied, respectively, the multi-input equalizer unit being configured to calculate outputs of the plurality of equalizer units and output the outputs as an equalized signal in a manner that a phase difference between two of the regions is set to be a predetermined phase difference; and a binarization unit configure

Abstract: The present disclosure relates to a reproduction apparatus. The reproduction apparatus may comprise an optical filter and electric filters. The optical filter may be configured to provide electrical signals corresponding to regions of an optical beam returning from an optical medium, the optical beam being incident on the optical filter, the regions of the optical beam corresponding to different bands in a line density direction and/or a track density direction. The electric filters may be configured to provide outputs based, at least in part, on the electrical signals provided by the optical filter, wherein the reproduction apparatus is configured to obtain a reproduced signal by combining the outputs of the electric filters.

Abstract: A data processing device includes a signal processing unit that performs timing recovery of sampling timing, in such a manner that a sampled value is obtained at sampling timing which is set as a target by phase interpolation processing according to a feed-forward control, with respect to sampling data which is obtained from a recovery signal.

Abstract: Provided is a signal quality evaluation apparatus, including an error pattern detection unit to which binarized data obtained by performing a PRML decoding process on a reproduced signal of bit information by partial response equalization and maximum likelihood decoding is input, the error pattern detection unit configured to detect at least one specific error pattern that is a bit pattern that is longer than a constraint length of the PRML decoding process, a metric difference calculation unit configured to calculate a metric difference of the at least one specific error pattern that has been detected by the error pattern detection unit, and an index value generation unit configured to generate an index value of a reproduced signal quality by using a distribution of the metric difference obtained by the metric difference calculation unit.

Abstract: A data detecting device includes a multi-input adaptive equalizer, a binarizing unit, and an equalization error calculating unit. The multi-input adaptive equalizer includes a plurality of adaptive equalizers and outputs a reproduction information signal from a target track and a reproduction information signal from a close track close to the target track as equalization signals by calculating outputs of the adaptive equalizers, the reproduction information signals being input to the adaptive equalizers, respectively as reproduction information signals. The binarizing unit obtains binarized data by performing a binarization process on the equalization signals.

Abstract: There is provided a skew detection method including supplying reproduction signals, which are respectively reproduced approximately simultaneously from at least two tracks including a first adjacent track and a second adjacent track located on both sides of a main track, to first and second filters, causing a combining unit to combine output signals of the first and second filters with a reproduction signal which is reproduced from the main track approximately simultaneously with the first adjacent track and the second adjacent track so as to cancel crosstalk, causing a coefficient control unit to obtain an error with a target value of the output signal of the combining unit and control coefficients of the first and second filters so as to reduce the error, and detecting a skew of an optical disc from values of coefficients of predetermined taps of the first and second filters.

Abstract: There is provided a skew detection method including supplying reproduction signals, which are respectively reproduced approximately simultaneously from at least two tracks including a first adjacent track and a second adjacent track located on both sides of a main track, to first and second filters, causing a combining unit to combine output signals of the first and second filters with a reproduction signal which is reproduced from the main track approximately simultaneously with the first adjacent track and the second adjacent track so as to cancel crosstalk, causing a coefficient control unit to obtain an error with a target value of the output signal of the combining unit and control coefficients of the first and second filters so as to reduce the error, and detecting a skew of an optical disc from values of coefficients of predetermined taps of the first and second filters.

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: A recording medium and apparatus enable the number of data units of recording pulse information to be reduced. The recording medium includes an information area for recording set values of a recording pulse for forming recording marks. The set values include preceding space-based set values having a first reference value as a set value of a recording pulse corresponding to a predetermined preceding space and a first difference set value of a recording pulse corresponding to a space other than the predetermined preceding space; and trailing space-based set values having a second reference value as a set value of a recording pulse corresponding to a predetermined trailing space and a second difference set value of a recording pulse corresponding to a space other than the predetermined trailing space and which is expressed as a difference from the second reference value.

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 a recording medium and a recording/reproducing apparatus which enable the number of data units of recording pulse information to be reduced by dividing the recording pulse information into 1 byte-parameter information and differences from a value thereof, and the recording pulse information to be recorded on an existing DI area.

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: A data detecting device includes a multi-input adaptive equalizer, a binarizing unit, and an equalization error calculating unit. The multi-input adaptive equalizer includes a plurality of adaptive equalizers and outputs a reproduction information signal from a target track and a reproduction information signal from a close track close to the target track as equalization signals by calculating outputs of the adaptive equalizers, the reproduction information signals being input to the adaptive equalizers, respectively as reproduction information signals. The binarizing unit obtains binarized data by performing a binarization process on the equalization signals.

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 reproducing apparatus for reproducing channel data from a recording medium using the ITR includes a reading unit reading an information signal recorded on the recording medium; a phase interpolator interpolating a phase of the information signal read on the basis of a phase error signal sent as a feedback; a first waveform equalizer equalizing a waveform of the phase-interpolated information signal while keeping the phase of the information signal fixed; a phase-error-signal generator generating the phase error signal to be sent as a feedback to the phase interpolator on the basis of the information signal whose waveform has been equalized by the first waveform equalizer; a second waveform equalizer equalizing the waveform of the phase-interpolated information signal without limiting a phase change; and a decoder generating the channel data by decoding the information signal whose waveform has been equalized by the second waveform equalizer.

Abstract: A reproducing apparatus includes the following elements. A reproducing head unit irradiates an optical disk with a laser beam to obtain a reproduced signal. An offset cancellation circuit cancels an offset element of the reproduced signal. An automatic gain control circuit adjusts the amplitude of the reproduced signal processed through the offset cancellation circuit. A band switching control unit detects a fingerprint period during which the reproduced signal is affected by a fingerprint on the surface of the optical disk and, for the fingerprint period, switches a frequency band in which the offset cancellation circuit and the automatic gain control circuit function to a higher frequency band than that associated with a non-fingerprint period. A decoding unit decodes the reproduced signal processed through the automatic gain control circuit to output binary data. A data reproduction processing unit performs reproduction processing on the binary data to obtain reproduced data.