Abstract: The present disclosure provides a robot and speech interaction recognition rate improvement circuit and method thereof. In the circuit, the main controller transmits a pre-recorded servo sound file to the first decoder in response to detecting the robot being in a motion state; the first decoder decodes the servo sound file to obtain a first sound analog signal of a servo sound; the analog-to-digital converter converts the first sound analog signal of the servo sound into a first sound digital signal, and converts a second sound analog signal collected by the microphone into a second sound digital signal; and the main controller further performs a suppression process on the servo sound in the second sound digital signal based on the first sound digital signal and the second sound digital signal. As a result, the influence of the sound of the servo of the robot is effectively reduced.

Abstract: A control method of an optical disc drive system is provided. Firstly, a first write command is issued to burn a first write data including plural data files to an optical disc in an optical disc drive. If a write fail message from the optical disc drive is received after a specified data block of a specified data file is transmitted to the optical disc drive, the transmission of the first write data is stopped. Then, a data amount of the specified data file that has not been transmitted to the optical disc drive is calculated, and a dummy data with the data amount is generated. Then, the dummy data and the other data files that have not been transmitted are burnt to the optical disc.

Abstract: A road furniture item or another type of road object is detected by at least one sensor. An associated geographic position associated with the road furniture item or road object is determined. After a predetermined time is reached, the geographic position is compared to a local database. A remote database is updated after the predetermined time is reached and according to the comparison with the local database. In some examples, the data indicative of the road furniture item or the road object is deleted based on a confidence level in the local database.

Abstract: Target levels in the PRML method are adaptively set under conditions of simplicity and a low cost. A method of setting a target level for reproduction of an optical information recording medium includes: a step of producing a reproduction signal from reflected light of laser light irradiated to an optical information recording medium; a step of performing waveform equalization processing, which depends on a predetermined partial response characteristic, on the reproduction signal to produce a waveform-equalized reproduction signal; a step of detecting peak levels for marks and spaces of a predetermined number of symbols from the waveform-equalized reproduction signal irrespective of a condition for a symbol adjoining each symbol; and a setting step of determining and setting values of a plurality of target levels, which is employed in Viterbi decoding and is arrayed with non-equal intervals among them, on the basis of a relative relationship among the detected peak levels.

Abstract: The present invention makes it possible to reproduce reproduction images without a break without having to use any additional identification information even when real-time recorded data is not completely continuous. A control circuit references a data identification flag (“Recording Type”) which is attached to each sector of reproduction data to indicate the type of recorded data, and counts the number of sectors to which the data identification flag representing real-time recorded data is attached. When the count is not smaller than a threshold value, the control circuit reproduces all the sectors of the target reproduction block in a real-time reproduction mode. In the real-time reproduction mode, the control circuit masks a portion of reproduction data that is found to be defective, changes the value of the defective data to 0 (zero), and transfers the resulting reproduction data to a host device.

Abstract: According to one embodiment, a method for operating log likelihood ratios in a disk apparatus is disclosed. Iterative decoding is applied to the disk apparatus. The method can set windows for a sequence of the log likelihood ratios output by a soft-decision most-likelihood decoder based on the sequence of the log likelihood ratios or an amplitude of a read signal acquired in response to read of data from a data sector on a disk carried out by a head. The method can multiply the log likelihood ratios contained in each of the windows, by a multiplier specific to each window. In addition, the method can transmit the sequence of the log likelihood ratios multiplied by the multiplier for each of the windows to a parity check decoder.

Abstract: A signal evaluation method according to the present invention is a method for evaluating a read signal, retrieved from an information recording medium, based on a binarized signal generated from the read signal by a PRML method.

Abstract: When the picture drops out in a part of video image data transmitted by a video transmitting apparatus, the video transmitting apparatus outputs a command indicating that the scene drops out, together with the video image data, to a video receiving apparatus. In accordance with this command, the video receiving apparatus displayed a predetermined indication that the scene drops out, or controls the re-recording of video image data.

Abstract: A dropout detection device, a disk reproduction apparatus, and a dropout detection method for detecting the occurrence of a dropout are provided. A low-pass filter outputs, as a signal LFENV, a low-frequency component of an envelope signal ENV generated by an envelope generation circuit, which represents an upper envelope of a first RF signal RF1 input from an RF amplifier unit. An adder adds a shift amount SH to the envelope signal ENV, and outputs a resultant signal as a shifted envelope signal SENV. A comparator outputs a dropout detection signal DET during a time period PT in which the signal LFENV is larger than the shifted envelope signal SENV. A detection control unit detects an amplitude ARF1 of the first RF signal RF1, and changes a frequency gain characteristic of the low-pass filter and the shift amount SH according to the magnitude of the detected amplitude AR1.

Abstract: Reproduced signals are equalized by the least square technique by using a predetermined number of data samples binarized by a Viterbi decoder. Even when data written on an optical disk is unknown, the data can be equalized in a stable manner and can be reproduced at a low error rate without instability factors such as divergence due to interference.

Abstract: The dropout detection circuit of the invention includes: a high-speed envelope detection circuit for detecting an envelope of a reflection signal of a light beam with a first time constant; a low-speed envelope detection circuit for detecting an envelope of the reflection signal with a second time constant larger than the first time constant; a differential circuit for generating a difference signal indicating the difference between the envelopes detected by the envelope detection circuits; and a comparator for converting the difference signal to a binary value according to a predetermined binary criterion. The high-speed envelope detection circuit makes the first time constant larger during recording than during reproduction, to enable stable dropout detection irrespective of during reproduction or during recording.

Abstract: An apparatus for preventing a writing error from occurring on an optical disc. The apparatus includes an interpolation ATIP sync signal detector, a number determiner, and a writing speed adjuster. The interpolation ATIP sync signal detector receives a wobble signal from the wobble signal generator of an optical disc drive to detect an interpolation ATIP sync signal from the wobble signal. The number determiner determines a number of interpolation ATIP sync signals and generates a writing speed transformation control signal based on the determination result. The writing speed adjuster receives the writing speed transformation control signal from the number determiner to adjust a writing speed of the optical disc drive.

Abstract: An apparatus and a method removing offset of a Phase Lock Loop (PLL) circuit in a disc drive without using a disc when data playback is performed, the apparatus including an ENDEC module and a PLL circuit. The ENDEC module outputs a binary signal if an offset removal mode is set. The PLL circuit removes the offset of the PLL circuit by comparing a phase of the binary signal with a phase of a channel bit clock signal. Therefore, a time to remove the offset of the PLL circuit is reduced and the possibility not to remove the offset of the PLL circuit due to a damaged disc is prevented.

Abstract: The invention discloses a decoding apparatus and the method thereof for decoding a signal retrieved by an optical information reproducing system from an optical information recording medium. N legal codes are predetermined. According to the invention, first, the retrieved signal is converted into a data stream. Then, in a Viterbi decoding manner, the data stream is decoded into a digital code in accordance with a level of the data stream and N reference levels. Then, the binary code is decoded by a binary array into one of the N legal codes, and each of the N legal codes corresponds to one of N reference levels. In particular, the N reference levels are corrected by various detected conditions to enhance the correctness of decoded data.

Abstract: The present invention provides highly reliable PLL without influence of variations in amplitude of a reproduced signal or variations in inclination of an edge. An information-reproducing apparatus according to the present invention includes a unit for detecting a phase difference between a reproduced signal and a reproducing clock signal, a PLL circuit for regulating a frequency of the reproducing clock signal to compensate for the detected phase difference, a unit for detecting a state of the PLL circuit, and a unit for regulating a loop gain of the PLL circuit corresponding to the detected state.

Abstract: The present invention relates to a frequency detection method for an optical disc bit data reproduction apparatus. The frequency detection method uses the optical disc bit data reproduction apparatus including an Analog to Digital Converter (ADC), an interpolator, an asymmetry compensator, a digital bit and successive bit length detector, a frequency detector, a phase detector and a Digital Controlled Oscillator (DCO). In the frequency detection method includes the primary frequency detection step and the secondary frequency detection step. In the primary frequency detection step, status of input RF digital bit data frequency versus sampling frequency is determined and the sampling frequency is corrected so as to allow the sampling frequency to be rapidly adjusted to the frequency of the RF digital bit data, thus primarily detecting frequency.

Abstract: A data reproduction device for sampling a signal reproduced from a recording medium based on a synchronization clock signal synchronized with the reproduced signal includes: an analog-to-digital conversion part converting the reproduced signal into a first digital signal based on a first clock signal; an interpolation part interpolating the first digital signal so that the first digital signal is equalized with a second digital signal sampled based on a second clock signal having a frequency n times the frequency of the first clock signal; an optimum phase detection part receiving the output of the interpolation part and detecting the phase error between the optimum point of the reproduced signal and the synchronization clock signal; a phase correction part correcting the phase of the reproduced signal based on the phase error; and an information data start detection part detecting the start of information data based on the phase error.

Abstract: A data recording/reproducing apparatus for use with a disc recording medium having a plurality of either concentric or spiral tracks formed thereon, each of the tracks being divided into a plurality of sectors is provided. The apparatus includes a seeking element for seeking a target track; a data accessing element for accessing data on the target track reached by the seek; and an error correcting element for correcting error in the data based on an error correction code generated by the error correcting element for error correction purposes.

Abstract: An optical disk reproducing device has a defect-signal generating circuit including a peak-holding-signal generating circuit for generating a peak-hold signal based on an RF signal read from a recording medium, an intermediate-signal generating circuit for generating an intermediate signal based on the peak-hold signal, a signal-level adjusting circuit for generating a threshold signal based on the intermediate signal, a threshold-signal adjusting circuit for adjusting the level of the threshold signal, and a comparator for generating a defect signal based on the peak-hold signal and threshold signal. The threshold-signal adjusting circuit includes at least one of: a first adjusting circuit for raising the threshold signal in the event the peak-hold signal falls below the threshold signal due to the peak-hold signal and the threshold signal being reversed; and a second adjusting circuit for lowering the threshold signal in the event the peak-hold signal exceeds the threshold signal, due to the reversal.

Abstract: A method for generating a wobble clock signal. When the wobble signal becomes deformed or a defect on the optical disc is found, the present invention provides a stable wobble clock signal, which is used to maintain a stable rotation speed when the optical disc is processed. In addition, the present invention also determines whether the wobble signal is deformed according to the result of comparing the width of the wobble signal at different status with the average of the half cycle width of the wobble signal.

Abstract: A read channel apparatus is disclosed for reading data recorded on an optical storage system at a predetermined baud rate. The apparatus asynchronously samples an analog read signal generating from the optical storage system and subtracts an estimated DC offset from the asynchronous sample values to generate a sequence of asynchronous DC-removed sample values. The asynchronous DC-removed sample values are separately interpolated by two interpolators to generate a sequence of synchronous even-time sample values and a sequence of synchronous odd-time sample values respectively. The synchronous even-time and odd-time sample values are separately equalized by two equalizers in accordance with a target spectrum to generate a sequence of even-time equalized sample values and a sequence of odd-time equalized sample values respectively. A DC offset estimator generates the estimated DC offset from the even-time equalized sample values and the odd-time equalized sample values.

Abstract: A frame synchronization signal detection apparatus includes a synchronization signal detector, a main frame synchronization signal generator, a sub frame synchronization signal generator, and an output unit. The synchronization signal detector detects and outputs a synchronization signal from a digital data signal. The main frame synchronization signal generator detects and outputs a first valid synchronization signal from the synchronization signal, as an internal frame synchronization signal, and generates and outputs a first insertion synchronization signal, as the internal frame synchronization signal, if the first valid synchronization signal is not detected in a predetermined first time period. The sub frame synchronization signal generator detects and outputs a second valid synchronization signal from a synchronization signal. The output unit outputs a frame synchronization signal.

Abstract: An offset adjusting circuit for an optical disc comprises an offset-adjustment differential operational amplifier having an input terminal to which an output signal of an optical pickup is input and the other input terminal to which a control voltage is applied, an A/D converter that outputs a digital signal based on an output signal of the offset-adjustment differential operational amplifier, and a control voltage adjuster that varies the control voltage applied to the offset-adjustment differential operational amplifier based on the digital signal so as to remove an offset.

Abstract: A read channel apparatus is disclosed for reading data recorded on an optical storage system. An exemplary sampling device samples an analog read signal generating from the optical storage system to generate a sequence of sample values. A subtractor subtracts an estimated DC offset from the sample values to generate a sequence of DC-removed sample values. An equalizer equalizes DC-removed sample values in accordance with a target spectrum to generate a sequence of equalized sample values. First and second interpolators interpolate the equalized sample values to respectively generate sequences of even-time sample values and odd-time sample values. A data sequence composed of the even-time and the odd-time sample values is substantially synchronized to the baud rate. A timing recovery controller controls the interpolators to synchronize the even-time and odd-time sample values to the baud rate.

Abstract: A read channel apparatus is disclosed for reading data recorded on an optical storage system at a predetermined baud rate. The apparatus asynchronously samples an analog read signal generating from the optical storage system and subtracts an estimated DC offset from the asynchronous sample values to generate a sequence of asynchronous DC-removed sample values. The asynchronous DC-removed sample values are separately interpolated by two interpolators to generate a sequence of synchronous even-time sample values and a sequence of synchronous odd-time sample values respectively. The synchronous even-time and odd-time sample values are separately equalized by two equalizers in accordance with a target spectrum to generate a sequence of even-time equalized sample values and a sequence of odd-time equalized sample values respectively. A DC offset estimator generates the estimated DC offset from the even-time equalized sample values and the odd-time equalized sample values.

Abstract: A first set of data is detected in a signal having synchronous samples and interpolated samples, wherein the first set of data is detected asynchronously as corresponding to one of the samples. A time to transmit a data-found signal is determined based on an offset between the data-detected sample and one of the synchronous samples, and the data-found signal is transmitted at the determined time to enable the synchronous processing of the synchronous samples. In one implementation, the synchronous samples correspond to a readback signal read from a data recording channel, the first set of data corresponds to servo address mark (SAM) data in a servo sector in the readback signal, and the synchronous processing is demodulation of burst data in the servo sector.

Abstract: A method of estimation parameter adaptability adjustment of an optical storage device. The method determines an estimation parameter according to a current data recording location of the optical storage device to estimate a channel bit rate. The method includes providing a two-dimensional estimation parameter table. The two-dimensional estimation parameter table includes a plurality of estimation parameters corresponding to linear velocities and data recording locations. The method further includes determining a linear velocity estimation value; and determining the estimation parameter according to the linear velocity estimation value, the current data recording location, and the two-dimensional estimation parameter table to estimate the channel bit rate.

Abstract: The invention proposes an appliance for recording or playing back information having means for signal generation from a wobble signal which is scanned from the undulating track on a recording medium, such as a DVD+RW. According to the invention, a signal scanned from the undulating recording track on the recording medium is supplied to a circuit arrangement for generating a clock signal which is both a square-wave voltage whose phase is synchronous with that of the signal and a signal with an even-numbered multiple of the frequency of the wobble signal contained in the signal. In this regard, the invention provides a phase locked loop which is synchronized with the signal and contains a frequency divider for actuating a digital phase shifter and for providing a clock signal which is a phase-synchronous square-wave voltage having the frequency of the wobble signal. The phase comparator provided is a multiplier which is formed using a changeover switch to which the signal and the inverted signal are applied.

Abstract: The dropout detection circuit of the invention includes: a high-speed envelope detection circuit for detecting an envelope of a reflection signal of a light beam with a first time constant; a low-speed envelope detection circuit for detecting an envelope of the reflection signal with a second time constant larger than the first time constant; a differential circuit for generating a difference signal indicating the difference between the envelopes detected by the envelope detection circuits; and a comparator for converting the difference signal to a binary value according to a predetermined binary criterion. The high-speed envelope detection circuit makes the first time constant larger during recording than during reproduction, to enable stable dropout detection irrespective of during reproduction or during recording.

Abstract: The present invention relates to method and apparatus of recording an audio signal composed of several tracks on a recording medium in a manner that the tracks can be distinguished each other in a recorded audio signal. The present track-synchronous recording method detects a no-sound interval longer than a predetermined time that is included in an input audio signal during recording the input audio signal, and records an audio signal following the detected no-sound interval with a different track number from that of recorded audio signal preceding the detected no-sound interval. Therefore, it is possible to individually distinguish tracks on a copy medium even though those not having any track information are copied thereto from an original at a time.

Abstract: Optimizing storage and retrieval of monitoring data. In one aspect of this disclosure, there is a system, method and computer readable medium that stores instructions for instructing a computer system, to optimize storage and retrieval of data. In this embodiment, a transfer manager component acquires the data from an archive and assigns predetermined storage values to specified parameters that form the data structure of the acquired data. A database stores the data acquired by the transfer manager component in accordance with the predetermined storage values. A middle tier component extracts the data in the database and interpolates the data in accordance with the predetermined storage values.

Abstract: A control system for an optical disc for optical media with a premastered area that cannot be overwritten and a user-writeable area that can be overwritten, comprises a first processor operable to communicate with a second processor via a status register. The first processor sequences and monitors functions performed in the second processor and the second processor issues an interrupt when an error condition is detected in the second processor. The first processor detects the interrupt, and disables detecting further interrupts until the interrupt is serviced. Servicing the interrupt includes recording the error state and changing focus and tracking parameters based on the error condition detected.

Abstract: An optical disk apparatus capable of suppressing displacement of a servo system from a track even when a track defect is caused on an optical disk and achieving appropriate data recording and reproduction. In the case where any track defect is detected on an optical disk, a pulse width modulation signal, rather than a tracking servo signal created based on a tracking error signal, is used as a servo signal to drive an optical pick-up. The pulse width modulation signal is modulated such that its DC level becomes identical to a DC level of a tracking servo signal obtained immediately before detection of the track defect.

Abstract: A read channel apparatus is disclosed for reading data recorded on an optical storage system at a predetermined baud rate. The apparatus asynchronously samples an analog read signal generating from the optical storage system and subtracts an estimated DC offset from the asynchronous sample values to generate a sequence of asynchronous DC-removed sample values. The asynchronous DC-removed sample values are separately interpolated by two interpolators to generate a sequence of synchronous even-time sample values and a sequence of synchronous odd-time sample values respectively. The synchronous even-time and odd-time sample values are separately equalized by two equalizers in accordance with a target spectrum to generate a sequence of even-time equalized sample values and a sequence of odd-time equalized sample values respectively. A DC offset estimator generates the estimated DC offset from the even-time equalized sample values and the odd-time equalized sample values.

Abstract: A servo control apparatus of an optical pickup includes an extractor for extracting an error signal from a read signal; an equalizer including a phase compensator for equalizing the error signal to generate a drive signal; a driver for changing the servo position of the optical pickup in response to the drive signal; a dropout detector for extracting an envelope signal from the read signal to detect a dropout of the read signal; and a controller. The controller changes an equalization characteristics of the equalizer in accordance with an amplitude of the envelope signal during the period of time when the dropout occurs or in response to an occurrence of the dropout.

Abstract: Bits in a first binary signal are compared with one or more first binary patterns. For each first binary patterns, if the comparison meets a predetermined criteria for the first binary pattern, than an evaluation value is calculated for that first binary pattern and for one or more secondary binary patterns that correspond to that first binary pattern, the evaluation value indicating the likelihood that each respective binary pattern corresponds with a portion of a run length limited binary signal represented by the bits of the first binary signal. The first binary signal is corrected to correspond with the binary pattern that was determined most likely to be a portion of the run length limited binary signal.

Abstract: In order to stably carry out reproduction of information in an optical disc medium (10) using a PRML (partial-response maximum-likelihood) method for reproducing the signal, the optical disc medium (10) has not only a data recording area (14) where data is recorded at high density but also a system information recording area (16) where information is recorded at low density and binary equalizing/reproducing can be easily made. Information required to circuit setting is recorded in the system information recording area.

Abstract: A basic data structure in a lead-in area is made coincident with each other in all of a read only type, write once type, and a rewritable type. The lead-in area is divided into a system lead-in area and a data lead-in area. A track pit and a pit pitch of pits in the system lead-in area are made longer than those in the data lead-in area. In the system lead-in area, a reproduction signal from a bit is detected in accordance with a Level Slice technique, and, in the data lead-in area and data area, a signal is detected in accordance with a PRML technique. In this manner, in any of the read only type, write once type, and rewritable type, there can be provided an information recording medium and an information reproducing apparatus or information recording and reproducing apparatus therefor, capable of a stable reproduction signal from a lead-in area of the write once type recording medium while maintaining format compatibility.

Abstract: In the case of a method of detecting a signal edge in a signal with temporally successive signal edges, there are performed, after triggering by an interrupt signal (IS) generated in an analog/digital converter (13), detection of a rise-representing rise value between two detected amplitude values with subsequent assessment of the rise value together with detection of signal edge direction information and signal edge occurrence information. Further use of this signal edge information is dependent on an additionally detected and assessed signal strength value, which signal strength value is formed from a sum of further amplitude values.

Abstract: A wave-shaping apparatus includes a first detection circuit for detecting a reproduction signal reproduced from an optical disk by an optical pickup circuit using a first detection time constant to detect an upper envelope of the reproduction signal; a second detection circuit for detecting the reproduction signal using a second detection time constant to detect a lower envelope of the reproduction signal; an averaging circuit for putting a weight represented by a weighting coefficient to each of the upper envelope and the lower envelope to calculate an average value of each of the upper envelope and the lower envelope; and a subtraction circuit for subtracting a signal corresponding to the average value from the reproduction signal to output a wave-shaped signal.

Abstract: A selective disturbance compensating apparatus for use in reproduction from an optical recording medium, and a 3T-correcting method. A DC offset canceller extracts a DC offset from a reproduction signal to cancel the DC offset. An equalizer equalizes the offset-cancelled signal. A switching unit selects between the offset-canceled signal and the equalized signal according to whether distortion caused by asymmetry of the signal is above or below a predetermined reference level. A 3-T correcting unit corrects asymmetry of the selected signal. In another embodiment, a second switching unit selects between the 3-T corrected signal and a Viterbi corrected signal.

Abstract: A PLL circuit is disclosed which extracts phase difference information of a high S/N ratio from a readout signal uses the phase difference information for PLL control. An A/D converter samples the input signal to produce a digital signal. A pattern string detector identifies a type of an input pattern string formed from a plurality of successive sample values successively outputted from the A/D converter and outputs pattern string identification information which indicates an identification result. A phase difference generator outputs phase difference information which indicates a phase error of the output of the A/D converter based on the pattern string identification information and the output of the A/D converter. A loop filter, a D/A converter and a voltage controlled oscillator generate a clock signal from the phase difference information to control the sampling timing of the A/D converter.

Abstract: In an apparatus for recording continuous information of sound or the like, when a disk device generating a seek sound is used as recording means, such state is prevented that seek sound is mixed as noise and is recorded. In an input processing system of an audio signal in an apparatus for performing sound recording to storage means generating seek noise of the disk or the like, cut-off period 203 is provided by the period when the seek noise 201 is generated, and mixing of the seek noise 201 in the audio signal is prevented, and at the same time, the audio signal during the cut-off period 203 is interpolated by other means or the seek noise level previously set is subtracted.

Abstract: A servo control apparatus of an optical pickup includes an extractor for extracting an error signal from the read signal; a driver for changing the servo position; an equalizer for equalizing the error signal to generate a drive signal; a calculator for calculating an integral value of the error signal for each predetermined angular section of rotation; a memory for storing each of the integral values for one rotation of the recording medium; a detector to detect an occurrence of a dropout; a calculator for calculating a variation by comparing the integral value for an angular section of rotation where the dropout occurred with a stored integral value for the identical angular section of rotation prior to the occurrence of the dropout; and a controller for changing an equalization characteristics of the equalizer in accordance with the variation.

Abstract: A reproducing apparatus for reproducing an audio signal from a record carrier having a first digital audio signal (a PCM encoded audio signal) recorded on it in a first format and a second digital audio signal (an MPEG encoded multi channel audio signal) recorded on it in a second format. The apparatus includes a read unit for reading an information signal from the record carrier, a decoding unit for channel decoding the information signal read from the record carrier into a decoded information signal, a keyboard for receiving a selection signal and an output terminal for supplying an output signal which comprises either the first digital audio signal or the second digital audio signal in response to said selection signal. An output circuit is available to add an identification signal (bit b1) into the output signal, indicating that the output signal includes either the first digital audio signal or another audio signal.

Abstract: A method for optical data recording and readout includes scanning a blank region of an optical recording medium while recording a data band including a plurality of adjacent data tracks; synchronizing the recording on all tracks to a common data clock; and simultaneously recording control tracks with the band of data tracks, each control track having a well-defined track center and a repetitive pattern of marks that is synchronized to the data clock. The method further includes optically sensing the cross-scan positions and clock offsets of at least one control track on either side of the data band; interpolating between the control track cross-scan positions to predict the cross-scan positions of each data track and compensate for magnification errors; interpolating between the control track clock offsets to predict the clock offset of each data track and compensate for skew errors; and simultaneously reading and decoding information recorded on all tracks of the data band.

Abstract: A signal of a run-length-limited code is reproduced from a recording medium. A transversal filter subjects the reproduced signal to a partial-response waveform equalization responsive to tap coefficients. Detection is made as to whether or not the reproduced signal corresponds to a peak point. Peak-point information is generated in response to a result of the detection. A delay circuit outputs at least three successive samples of the peak-point information. A temporary decision device operates for calculating a temporary decision value of the equalization-resultant signal on the basis of the successive samples of the peak-point information. A difference between the temporary decision value of the equalization-resultant signal and an actual value thereof is calculated, and an error signal is generated in response to the calculated difference. The tap coefficients of the transversal filter are controlled in response to the error signal so as to minimize the error signal.

Abstract: In an information detecting circuit, an equalizer equalizes an output from an A/D converter as an A/D converting information. A first interpolation circuit generates an interpolating value. A delay circuit delays the A/D converting information with a delay quantity equivalent to an output delay quantity of the equalizer. A second interpolation circuit generates an interpolating value. An interpolating position generating circuit produces an interpolating position information for generating an interpolating value synchronized in phase with the channel clock and supplies the interpolating position information into the first interpolation circuit and the second interpolation circuit. A binary encoder converts the output of the first interpolation circuit. A tap coefficient controller generates a tap coefficient from interpolating value outputs of the first and second interpolations. A rate correcting circuit converts the tap coefficient to be fed-back to the equalizer.

Abstract: An optical disk reproducing device, comprises a judgement circuit which, under an operating condition in which demodulated data amounting for one frame are being stored in a memory in synchronism with internally supplemented synchronous signals, and when an external first synchronous signal is detected from read-out signals, judges whether the external first synchronous signal appears in the first half or in the second half in the period of the internally supplemented synchronous signal, and when the judgement circuit judges that the external first synchronous signal appeared in the first half of the period of the internally supplemented synchronous signal, the demodulated data amounting for one frame are stored in the memory at a memory position for the immediately previous frame.

Abstract: A data read method includes a steps of reading identical data from one region on a recording medium a plurality of times, a step of comparing the data read the plurality of times in units of one or a plurality of bits to obtain comparison results, and generating read data made up of data values having a highest frequency for each unit based on the comparison results, and a step of carrying out an error detecting and correcting process with respect to the read data.