Abstract: When recording recording information by forming on a recording medium a recording mark whose mark length is an integral multiple of the reference mark length according to a recording signal generated from a recording information signal, this method performs a process of: generating, after recording compensation recording information on the recording medium, a reproduction signal by reading out the compensation recording information; generating from the reproduction signal a reproduction clock whose cycle corresponds to the reference mark length; setting a signal level suitable for binarization determination of the reproduction signal as a distribution reference level, according to the difference in variation between white and black levels of the reproduction signal; and calculating the recording correction value for correcting the compensation recording signal, so that the reproduction signal becomes closer to the distribution reference level around a target cross timing determined based on the reproduction c

Abstract: In a coupled ring oscillator including q ring oscillators each including p inverter circuits connected together to form a ring shape, and a phase coupling ring including (p×q) phase coupling circuits each of which is configured to couple an output of one of the p inverter circuits of one of the q ring oscillators to an output of one of the p inverter circuits of another one of the q ring oscillators in a predetermined phase relationship, and which are connected together to form a ring shape, for at least one group made up of one of the p inverter circuits in each of the q ring oscillators, outputs of the q inverter circuits belonging to the at least one group are fixed in phase with one another, the q ring oscillators are caused to oscillate in the in-phase fixed state, and then, the outputs of the q inverter circuits are released from the in-phase fixed state.

Abstract: The present techniques provide systems and methods for decoding a data signal with a control bit to improve bit estimation. The techniques in one embodiment involve using decoding algorithms to estimate the a posteriori state probabilities and the a posteriori transition probabilities of the data encoding, and estimating bit state probabilities. The techniques further involve using a control bit in the bit stream and comparing the estimation of the control bit state in the segment of the bit stream with a test control bit determined based on an average of bit states from the encoded segment of the bit stream. If the estimation of the control bit and the test control bit are not equal, the state of the bit estimate with the lowest confidence probability will be changed.

Abstract: There is provided an optical recording method for directing a recording pulse train to an optical disc medium to form marks thereon and for recording information as information about the edge positions of said marks and the spaces between marks, the recording pulse train having been created by modulating laser light into plural power levels. The method includes: coding to-be-recorded data into coded data consisting of the combination of marks and spaces; classifying said marks within said coded data on the basis of the mark length and the preceding or succeeding space lengths of the marks; shifting the position of the second pulse edge counted from the end portion of the recording pulse train for forming said marks, depending on the result of said classification, to adjust said recording pulse train; and directing said recording pulse train to the optical disc medium to form said marks thereon.

Abstract: A method for to restore quantization data to binary data in a system for recording and/or reproducing the binary data includes selecting a selection region predicted to include an alignment mark from the quantization data, determining a location of the alignment mark within the selection region; and converting the quantization data to the binary data based on a comparison of the determined location of the alignment mark and an original location of the alignment mark.

Abstract: The use of a multi-track format in both optical and magnetic data storage applications provides for a number of improvements to system performance including data density and data transfer rates. However, the full advantage in data density can only be achieved through the use of joint equalization and joint detection. The complexity of implementation of these functions arc addressed with a transform domain equalization architecture and a reduced complexity detection method based on a breadth first search of a time-varying trellis. The trellis results from a one dimensional representation of a two dimensional target response, obtained by arranging samples from adjacent tracks in a sequence that respects the original proximity of the samples.

Abstract: To provide an optical disk and an optical disk reproducing device capable of preventing sub information from being illegally copied and altered. An optical disk includes an optical disk substrate preliminarily provided with concave/convex recording marks in order to record the main information; and a reflection film which covers the optical disk substrate and of which the reflection coefficient is changed by irradiating laser light at or above a certain intensity. The reflection film is preliminarily provided with additional marks for recording the sub information by changing the reflection coefficient of the reflection film on a region where the concave/convex recording marks are formed and the sub information is recorded for every predetermined recording unit for recording the main information. The laser light at or above the certain intensity is irradiated onto the region where the sub information is recorded to reproduce the main information and delete the sub information.

Abstract: The present invention allows usable information to be selected by comparing information regarding encoding with conditions regarding encoding processing. When delay modes, picture structures, and pulldown modes do not match each other between previous encoding time and re-encoding time, parameters are not reused. When they match and image frames do not match, a picture type is reused. When a bit rate in the previous encoding is smaller than that in the current encoding and a chroma format is larger than the current chroma format, a picture type and a motion vector are reused. When the conditions are not satisfied, parameters are supplied and received and a determination is made as to whether or not chroma formats match each other. When the chroma formats do not match each other, picture-type information, motion-vector information, and quantization-value information are reused. When the chroma formats match each other, stream data input to a decoding unit is output.

Abstract: An optical disc apparatus implementing a PRML and capable of recording and reading a plurality of disc media with different recording densities, wherein read compatibility between drives is ensured without relying solely on the error correction capability of the ECC (error correction code). A phase comparator provided in a PLL compares each value of an input signal sequence with a designated threshold value in order to determine an edge. The optical disc apparatus can record and read a plurality of disc media with different recording densities while ensuring read compatibility.

Abstract: A method of reproducing multilevel information using a light spot. The multilevel information is recorded by defining virtual cells at regular intervals on tracks of an optical information recording medium and varying sizes of information pits in the cells. The method includes the steps of obtaining cell boundary values, each of the cell boundary values being obtained by performing sampling when the center of the light spot reaches a boundary between adjacent cells, calculating cell boundary value metrics on the basis of the cell boundary values and prestored reference values for the cell boundary values, calculating path metrics on the basis of the cell boundary value metrics, selecting a path metric having a minimum value of the path metrics, and reproducing the multilevel information on the basis of the path metric having the minimum value of the path metrics.

Abstract: A decoding apparatuses and a method utilized in an optical storage device are disclosed. The decoding apparatus includes: a level slicer for setting a plurality of adjustable boundary values to distinguish a plurality of signal regions, and outputting a set of state values in accordance with signal regions corresponding to an input value; and a Viterbi detector coupled to the level slicer for decoding a transmission data according to the state value.

Abstract: Because conditions for recording identification data of a medium vary in accordance with the structure of different media, such as a single-layer or a multiple-layer structure, stable data recording has been a difficult task. To solve this problem, an incident side of the laser beam for recording identification data on a single-layer optical disk 5 and a double-layer optical disk 6 is the opposite side of a substrate 1 upon which user data is recorded. From this structure, even in a double-layer optical disk 6, the recording is not affected by the recording layer of a second layer 12b and the like. Therefore, in the double-layer optical disk 6, identification data of the medium can be recorded under the same conditions as the single-layer optical disk 5.

Abstract: The present techniques provide systems and methods for decoding a data signal with a control bit to improve bit estimation. The techniques in one embodiment involve using decoding algorithms to estimate the a posteriori state probabilities and the a posteriori transition probabilities of the data encoding, and estimating bit state probabilities. The techniques further involve using a control bit in the bit stream and comparing the estimation of the control bit state in the segment of the bit stream with a test control bit determined based on an average of bit states from the encoded segment of the bit stream. If the estimation of the control bit and the test control bit are not equal, the state of the bit estimate with the lowest confidence probability will be changed.

Abstract: An optical medium storage device improves the usable life of re-writable optical storage mediums, such CD-RW, DVD+RW and DVD-RAM disks, by adjusting write parameters to compensate for time between an initial write on the optical storage medium and the current time, with adjusted write parameters fine-tuning signal-to-noise ratios and improving the number of reliable overwrites for the optical storage medium.

Abstract: Subversive DSV (SDSV) sequences of data symbols having a large absolute value of DSV are extremely valuable in the copy protection of optical discs as they can induce uncorrectable read errors. However, very few SDSV sequences of data symbols can be found in multimodal codes such as Eight-to-Sixteen Modulation (ESM) utilised in DVDs. It is required to select data symbols, for encoding using a multimodal code, which are capable of forcing an encoder to produce at least one subversive sequence of code words. A possible code word for a data symbol is selected if the code word has a large absolute value of DSV and there are no alternative code words, or all alternative code words are equivalent, or all alternatives except one are ruled out by RLL rules.

Abstract: An address information modulation method includes using a first characteristic of a first modulation method and a second characteristic of a second modulation method to modulate address information and/or additional information. Accordingly, a data amount of information, to access a disc, in a predetermined space of the disc is increased, and the modulated information is formed in a form of a wobble signal in a track. Here, the first characteristic of the first modulation method can be physical location information of an MSK-modulated signal, and the second characteristic of the second modulation method can be sign information of a second harmonic wave obtained by an HMW modulation, which synthesizes a cosine function of a basic frequency of a wobble signal with a sine function having a frequency that is a multiple of the basic frequency of the wobble signal.

Abstract: A record carrier of a disc-like optically inscribable type, has a preformed track in which an auxiliary signal including a sequence of codes recorded by a preformed track modulation. The codes include a sequence of address codes specifying the addresses of the track portions in which the address codes are recorded and special codes. The special codes can be distinguished from the address codes and specify control data for controlling a recording by a recording device. The record carrier is provided with an extended area preceding a program calibration area. The extended area includes special codes representing additional control information for controlling the recording.

Abstract: A recording medium comprising a recording area, the recording area includes a first area and a second area, the first area includes a frame area, the frame area includes an area in which a second synchronization code sequence and at least a portion of data are to be recorded, and the second area includes an area in which a third synchronization code sequence and a fourth synchronization code sequence are to be recorded.

Abstract: A recording condition on a media is optimized by introducing a new evaluation index. An apparatus for optical information recording and reproducing includes: a measurement means for recording codes including a specific code in a medium for optical information recording and reproducing, reproducing the codes from the medium for optical information recording and reproducing, and measuring, from a reproduced signal of the codes, a peak value of amplitude of a reproduced signal related to the specific code, the peak value being a maximum value or a minimum value of the amplitude of the reproduced signal related to the specific code; a statistic calculation means for calculating preset statistic by using a plurality of peak values at the same or different recording places, the plurality of peak value having been obtained by the measurement means; and a condition decision means for deciding at least one of a recording laser power condition and a recording pulse condition by using the statistic.

Abstract: An optical information reproducing method capable of determining multi-level information with high precision, and an apparatus for the method. Specifically, a cell having a reduced multi-level is provided in a portion of a data region to perform the level correction or automatic gain control. For example, a cell recorded with an M-value for each group including a plurality of cells, each of which is recorded with an N-value (N>3, M<N), is provided. A reproduction signal level of a cell recorded with the N-value, which follows the cell recorded with the M-value, is corrected based on a difference between a cell center value of a reproduction signal sampled when a center of a light spot is moved to a center of the cell recorded with the M-value and a reference value obtained from learning information.

Abstract: A playback apparatus plays back information from a recording medium having a data structure including sync signals added in units of data items each having a predetermined size. The information is recorded in runlength limited codes, and the signals correspond to consecutive unique run lengths. The apparatus includes an information reading unit that obtains a binary data string as read information by reading the medium, a sync detection unit that performs detection of sync signals from the data string, and a data demodulation unit that obtains played-back data from the medium by performing demodulation on the data string with timing based on the detected signals. On the basis of detection, from the data string, of one detection pattern among types of detection patterns set as patterns including at least one of the unique run lengths, the sync detection unit regards the pattern detection as the signal detection.

Abstract: A recording and reproducing system is broken down into a recording unit for producing a digital audio data signal from MIDI music data words asynchronously produced at irregular intervals and a playback unit for reproducing the MIDI music data codes from the digital audio data signal, wherein synchronous data nibbles are supplemented in the irregular intervals among the MIDI music data words for producing a data stream, and the digital audio data signal is produced from the data stream through a differential phase shift keying and a phase code modulation so as to record the MIDI messages in a digital versatile disk at high dense.

Abstract: Optical disk players include a disk spinning system that is configured to spin an optical disk at a constant linear velocity and a burst cutting area decoding system that is configured to decode data in a burst cutting area of the optical disk, while the optical disk is spinning at the constant linear velocity. The burst cutting area data decoding system may be configured to determine a rotational frequency of the optical disk while reading the data in the burst cutting area, and using the rotational frequency that was determined to decode the data in the burst cutting area that was read.

Abstract: According to one embodiment, a device includes a filter which limits a frequency bandwidth of a reproduced signal from an optical disc, an AD conversion module which converts an output signal from the filter into a multilevel digital signal, an equalizing module for equalizing a waveform of the multilevel digital signal based on a predetermined partial response class and generating an equalizing playback signal, a detection module for generating binary data corresponding to data recorded on the optical disc based on the equalizing playback signal, a module for determining an amplitude value of each of an input signal to and an output signal from the equalizing module with respect to each binary data sequence output from the detection module, and a module for adjusting a high-frequency amplification amount of the filter such that an amplitude value before waveform equalization and an amplitude value after waveform equalization satisfy a predetermined relationship.

Abstract: An object of the present invention is to record or reproduce time-sequential data to/from recording media exemplified by hard disks at the transfer speed closer to that of the recording medium.

Abstract: Systems and methods for encoding/decoding are provided. The systems and methods include encoding a stream of K-bit input sequences into a stream of (G, I, M)-constrained 2N-bit output sequences by transforming each K-bit input bit sequence into two separate data paths including even and odd bits. Enumerative maximum-transition-run (eMTR) encoding of the even bits generates constrained even bits, and enumerative maximum-transition-run (MTR) encoding of the odd bits generates constrained odd bits. The constrained even and constrained odd bits are interleaved to form a stream of (G, I, M)-constrained 2N-bit output sequences where G is a global constraint, I is an interleave constraint, and M is a variable frequency oscillator constraint of a partial-response maximum-likelihood (PRML) codeword. Decoding systems and methods are also provided.

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 usable information to be selected by comparing information regarding encoding with conditions regarding encoding processing. When delay modes, picture structures, and pulldown modes do not match each other between previous encoding time and re-encoding time, parameters are not reused. When they match and image frames do not match, a picture type is reused. When a bit rate in the previous encoding is smaller than that in the current encoding and a chroma format is larger than the current chroma format, a picture type and a motion vector are reused. When the conditions are not satisfied, parameters are supplied and received and a determination is made as to whether or not chroma formats match each other. When the chroma formats do not match each other, picture-type information, motion-vector information, and quantization-value information are reused. When the chroma formats match each other, stream data input to a decoding unit is output.

Abstract: A digital signal reproducing apparatus includes an analog to digital converter for sampling and quantizing a signal read from an optical recording medium in accordance with a reproduced clock having a frequency which is one-half of a channel bit frequency and outputting an obtained digital RF signal, an offset compensation circuit for reducing an offset component in an amplitude direction from the digital RF signal, and a simplified interpolation filter for reconstructing a signal indicating a predetermined pattern recorded in the optical recording medium from the output signal of the offset compensation circuit and outputting the reconstructed signal. A control operation is performed to reduce the magnitudes of respective values shown by first phase error information on a section with the predetermined pattern and by second phase error information on a section other than the section with the predetermined pattern.

Abstract: The present invention provides a multi-level information recording/reproducing method of recording or reproducing multi-level information by virtually setting cells at constant regular intervals on a track of an optical information medium where information is recorded or reproduced with a light spot and by varying an information pit width in a direction of the track or an information pit area, comprising the steps of: detecting a reproduced signal by radiating a light spot onto the track; detecting a cell border value by sampling the reproduced signal when the center of the light spot falls on a border between one cell and its following cell; and judging multi-level information of the following cell based on the cell border value.

Abstract: A data recording method according to the present invention is a method for recording data as edge position information, including marks and spaces of multiple different lengths, on a storage medium by irradiating the storage medium with a pulsed energy beam. The method includes the steps of: (A) generating a write code sequence based on the data to be recorded; (B) determining a write pulse waveform, defining the power modulation of the energy beam, according to the code lengths of respective codes included in the write code sequence; and (C) modulating the power of the energy beam based on the write pulse waveform.

Abstract: Separate sets of optical medium identification information are embedded in separate aligned layers of the optical medium to allow an optical drive to initiate use of the optical medium with information from both layers. For instance, a first set of identification information is embedded in the data layer of the optical medium and a second set of identification information is embedded on the protective surface layer of the optical medium. The first and second sets of information align so that a mixed signal is provided when the optical medium is initially inserted in the optical drive with the optical drive reading the separate sets of information while the read head is at a single location.

Abstract: A multi-level information reproducing method is provided which can increase the degree of separation between distributions of cell boundary values to thereby improve the accuracy of reproduction. Specifically, in a method of reproducing multi-level information recorded on a track of an optical information recording medium by virtually providing cells at equal intervals and by varying a width of an information pit in a track direction or an area of an information pit, a cell boundary value (a value obtained by sampling a reproduced signal when a center of a light spot is located at a boundary of cells) is corrected based on cell center values of two cells adjacent to the boundary (a value obtained by sampling a reproduced signal when the center of the light spot is located at a center of a cell), and the multi-level information is reproduced based on the corrected cell boundary value.

Abstract: To provide a highly user-friendly content moving device which prevents unauthorized copying of content and, when content that has been irreversibly converted and moved to a recording medium is moved back to a move source, can use the content in its form before irreversible conversion. A partial information extraction unit extracts, from content stored on a content storage unit, partial data necessary for playback of the content, and a write/read unit writes the partial data to a partial information storage unit and overwrites a portion of the content corresponding to the partial data with different data, while a conversion unit transcodes the content and writes the transcoded content and the partial data to the recording medium.

Abstract: A data recording method according to the present invention is a method for recording data as edge position information, including marks and spaces of multiple different lengths, on a storage medium by irradiating the storage medium with a pulsed energy beam. The method includes the steps of: (A) generating a write code sequence based on the data to be recorded; (B) determining a write pulse waveform, defining the power modulation of the energy beam, according to the code lengths of respective codes included in the write code sequence; and (C) modulating the power of the energy beam based on the write pulse waveform.

Abstract: A sampling rate for extracting information encoded on an optical disk is determined. First and second instances of a signal representing data encoded on the disk is detected, from which a disk rotation speed is determined. Based on the disk rotation speed, a sampling rate is determined.

Abstract: A data recording method according to the present invention is a method for recording data as edge position information, including marks and spaces of multiple different lengths, on a storage medium by irradiating the storage medium with a pulsed energy beam. The method includes the steps of: (A) generating a write code sequence based on the data to be recorded; (B) determining a write pulse waveform, defining the power modulation of the energy beam, according to the code lengths of respective codes included in the write code sequence; and (C) modulating the power of the energy beam based on the write pulse waveform.

Abstract: A recordable optical information recording medium having an address t for each sector, comprises: an area A1 starting from an address t1 to which access is made only when a recording apparatus performs recording operation; an area A2 starting from an address t2 to which access is made either when the recording apparatus performs the recording operation or when the recording apparatus performs reproducing operation; and an area A3 starting from an address t3 to which access is made either when either the recording apparatus or a reproducing apparatus performs recording or when either the recording apparatus or the reproducing apparatus performs reproducing. The addresses t are set consecutively with respect to a physical arrangement of the sectors in each of the areas A2 and A3, and the area A1 has at least one inconsecutive part at which the addresses t are not consecutive with respect to the physical arrangement of the sectors.

Abstract: A partial response is utilized to record information on a medium and then regenerate the information from the medium. A regenerating system undergoes equalization including subjecting a regeneration signal from the medium to the convolution of (k?s·D) (where D is one (1) bit delay operator, and k and s are positive integer). Such convolution is performed in the regenerating system so that low-frequency band noises are reduced with an improved error rate. The information is decoded from the equalized signal by use of maximum-likelihood detection.

Abstract: A method of modulating a source data to a code data under condition of a given code rate and run length limited (rll). The method including (a) inputting the source data, and (b) modulating the source data into code data by converting source data of 2 bits into code data of 3 bits under a condition of a given code rate. Further, the modulating step (b) further includes converting source data of 4 bits into code data of 6 bits, source data of 6 bits into code data of 9 bits, and source data of 8 bits into code data of 12 bits, based on a bit sequence of the source data.

Abstract: Data having a basic data length of m bits is modulated to a variable-length code having a basic code length of n bits. A sync signal is added to the data after a minimum bit-run in the data. The sync signal exhibits two or more patterns, each pattern breaking a maximum bit-run and having six channel bits for identifying each sync signal. The two or more patterns are distinguished from one another, with a detection distance of at least two therebetween.

Abstract: A waveform equalization control device includes a waveform equalizer that has a filter provided with a plurality of taps, updates the tap coefficient of each of the plurality of taps in accordance with a tap coefficient signal inputted thereto, causes the plurality of taps to respectively receive a plurality of values sampled at different time points from an input signal, performs waveform equalization with respect to the input signal, and outputs the signal after the waveform equalization, an equalization target value generation unit for determining an equalization target value, an error estimation unit for obtaining the error between the equalization target value and the signal after the waveform equalization, and a coefficient update unit for determining an amount of updating the coefficient of each of the taps of the filter of the waveform equalizer based on the error signal and on the input value to each of the taps and outputting the amount of updating the tap coefficient as the tap coefficient signal.

Abstract: Signal quality evaluation is performed using a predetermined reproduction signal, a first pattern corresponding to a signal waveform pattern of the reproduction signal, and a given pattern corresponding to the signal waveform pattern of the reproduction signal and being different from the first pattern.

Abstract: An ADIP (address in pre-groove) signal detection circuit is capable of correctly and quickly detecting discontinuous points in a wobble signal, and has a simple configuration in a wobble detection system of an optical disc device such as a DVD+R/RW, and an ADIP signal detection method thereof. The ADIP signal detection circuit performing the ADIP signal detection method includes one or two window comparators, two edge detection circuits each consisting of an exclusive OR circuit and an AND circuit, and two discontinuous point determination circuits each consisting of a flip-flop and a counter. Therefore, the ADIP signal detection circuit has a simple configuration so that it can be easily implemented. Also, since the ADIP signal detection circuit has a fast operation speed, the ADIP signal detection circuit detects discontinuous points correctly and quickly.

Abstract: A recording medium comprising a recording area, the recording area includes a first area and a second area, the first area includes a frame area, the frame area includes an area in which a second synchronization code sequence and at least a portion of data are to be recorded, and the second area includes an area in which a third synchronization code sequence and a fourth synchronization code sequence are to be recorded.

Abstract: A recording medium comprising a recording area, the recording area includes a first area and a second area, the first area includes a frame area, the frame area includes an area in which a second synchronization code sequence and at least a portion of data are to be recorded, and the second area includes an area in which a third synchronization code sequence and a fourth synchronization code sequence are to be recorded.

Abstract: It has been discovered that inaccurate representations of content read from an optical disc can be restored. A representation of content read from a damaged optical disc may include data that corresponds to misread data sections. The data for the misread data sections can be replaced with portions of an accurate representation of the content. The portions can be extracted from an accurate representation maintained online or at a local repository of digital representations of content.

Abstract: It has been discovered that damage to an optical disc can be used as a damage signature for that optical disc. The damage signature can be digitally represented to uniquely identify the optical disc in combination with other identifying information that identifies the optical disc. Services, such as a restore service, can be provided to a user after validation of a digital damage signature of an optical disc.

Abstract: In an optical disk of HD-DVD, data is recorded in both grooves and lands. A groove track includes its own data region called a groove (G) track address system formed therein and a land track includes its own data region called a land (L) track address system formed therein. One bit of address data is composed of four redundant wobble waves. When only three or two of the four wobble waves can be detected, an error is determined. When an error is determined in tracing of a groove track, bit data of the L track address system is used to correct the error. When an error is determined in tracing of a land track, bit data of the G track address system is used to correct the error.

Abstract: The present invention relates to method for recording program specific information (PSI) for a recorded data stream in an optical disk such as a high-density digital versatile disk (HD-DVD) and providing the recorded PSI to a presenting device such as a digital television. This method writes program or stream specific information in a management data recording area of a high-density disk, and when the recorded data stream is reproduced, determines whether it is time to send the stream specific information, obtains stream specific information corresponding to a stream object being reproduced, or to be reproduced based on the determination result, and transmits the obtained stream specific information.