Abstract: An ADIP decoder for decoding address in pre-groove (ADIP) of a wobble of an optical disc, has: a band pass filter that filters a wobble signal having a period corresponding to the wobble; a wobble PLL circuit that divides a frequency of a phase-locked clock signal in response to an input of the filtered wobble signal, and outputs a locked wobble signal; a timing generating circuit that generates a sampling timing signal based on the clock signal; an analog to digital converter that converts the filtered wobble signal into a digital signal in synchronization with the sampling timing signal; and an ADIP decoding circuit that counts a clock of the locked wobble signal with a counter, holds an address and one of a minimum amplitude value and a maximum amplitude value of the digital signal for each counter period, the address corresponding to a wobble clock count value where the digital signal has one of the minimum amplitude value and the maximum amplitude value, and that decodes the ADIP based on a distribution

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: A method of determining characteristics of a signal and an apparatus using the method. The apparatus for determining characteristics of a signal includes: a level detector receiving sample values of a radio frequency (RF) signal and binary data obtained by binarizing the RF signal, generating selection signals based on the binary data, classifying each of the sample values of the RF signal into one of a plurality of levels using the selection signals, and outputting average values of sample values of each level; and a signal characteristics determiner determining a characteristics value that indicates the characteristics of the RF signal using the average values of the sample values belonging to each level.

Abstract: An apparatus and method for measuring the quality of a signal on an optical disc based on level information of a viterbi decoder are provided. The signal quality measuring apparatus includes: a binary unit that generates binary signals from input RF signals; a channel identifier that receives the input RF signals and the binary signals output from the binary unit and outputs reference level values corresponding to the binary signals; and an information calculator that receives the reference level values and detects a signal quality value.

Abstract: An apparatus for light spot servo signal detection for reading an optical recording medium having a plurality of non-writable areas between writable data areas containing address information. An optical pickup provides a light spot to the non-writable areas of the optical recording medium with a predetermined state according to a control signal, and detects optical reflecting signals from the optical recording medium to generate a detection signal. A signal adjusting module offsets signal levels of the detection signal to an operating range to generate an offset shifted detection signal. An analog to digital converter digitizes the offset shifted detection signal to generate a digital signal. A detection circuit detects the servo detection signal according to the digital signal.

Abstract: A signal processing apparatus of an optical disk recording/reproducing apparatus and a signal processing method performed thereby are provided. The signal processing apparatus may include an operational data generation unit for receiving digital signals, filtering received digital signals and outputting filtered signals as operational data and a data arithmetic-operation unit for performing an arithmetic operation on the operational data output by the operational data generation unit in response to a command.

Abstract: An optical information recording/reproducing apparatus is adapted to record and/or reproduce multilevel information on/or from an optical information recording medium. The multilevel information is recorded in the form of pits in cells virtually formed at regular intervals on a track. The respective levels are represented by varying the length or the area of information pits such that a reproduced signal has a different amplitude level depending on the length or the area of information pits. A reproduced signal correction circuit corrects a reproduced signal obtained by performing sampling at the center of each cell. An error power calculation circuit calculates error power on the basis of the difference between the corrected reproduced signal and an ideal value of each level of the cell. A decoder performs decoding on the basis of the calculated error power values.

Abstract: A device for processing a radio frequency (RF) signal of an optical disk drive includes a high-pass (HP) filter, an RF variable gain amplifier (VGA), an RF analog-digital converter (ADC), and a digital module. The HP filter filters the RF signal and is capable of selectively utilizing one of a first cut-off frequency and a second cut-off frequency. The RF VGA amplifies the filtered RF signal. The RF ADC converts the amplified RF signal into a digital code. The digital module is capable of executing a first function and a second function with the digital code. The HP filter utilizes the first cut-off frequency when the digital module desires to execute the first function, and the HP filter utilizes the second cut-off frequency when the digital module desires to execute the second function.

Abstract: A parameter acquisition unit acquires parameters of a write strategy corresponding to the type of an optical disk upon which data is to be recorded, and a recording unit irradiates pulse modulated laser light upon the optical disk based upon the parameters of the write strategy acquired by the parameter acquisition unit, and forms marks corresponding to the data to be recorded in order upon the optical disk. A timing setting unit sets a sampling period, using the parameters of the write strategy acquired by the parameter acquisition unit, within the period from after the completion of formation of a mark upon the optical disk to the start of formation of the next mark. And, during this sampling period which has been set, a sampling unit performs sampling of a signal used for servo control, and a sampling servo control unit performs servo control based upon the signal which has been sampled.

Abstract: A loss of performance of slicer adaptation at high capacities due to the mismatch between the exact bits used in the computation of the RDS for the DC-control on the one hand and the often erroneous threshold decisions that are preliminarily made based on the HF waveform on the other hand, is resolved by performing a new method of DC-control at the encoder: the RDS is modified such that it is not based on the exact channel bits, but on the threshold decisions from a synthetic HF signal waveform that is generated based on a nominal MTF (modulation transfer function) or its IRF (impulse response function) of the channel. In this way, the impact of the erroneous threshold decisions in the receiver are already taken into account at the encoder, and the slicer control is no longer negatively affected thereby.

Abstract: A high-speed mixed analog/digital PRML data detection and clock recovery apparatus and method. The high-speed mixed analog/digital PRML data detection and clock recovery apparatus includes a variable gain amplifier, an analog equalizer, an analog-to-digital (A/D) converter, a DC offset remover, a level error detector, a Viterbi decoder, and an adaptive digital controller. The adaptive digital controller separately stores the level error values by predetermined frequencies, calculates predetermined coefficient values by each frequency component based on the level error values, and D/A-converts and applies the calculated predetermined coefficient values to the variable gain amplifier and the analog equalizer.

Abstract: An optical disk apparatus has a highly accurate trial writing function corresponding to a PRML system and copes with a bad jitter of a 2Tw mark in order to realize an optical disk, the recording/reproduction of which is enabled in both a DVD and a Blu-ray Disc by a drive. After a reproducing signal is A/D-converted, error pulse generation is enabled corresponding to the PRML by detecting an edge signal level, and an error pulse is generated when the level exceeds a threshold. At the same time, trial writing that corresponds to the difference in the jitter of the 2Tw mark and a mark of 3Tw or more is enabled by providing multiple error pulse thresholds.

Abstract: In a playback signal processing device for extracting, from an analog playback signal, playback data and a clock synchronized with the playback data, a digital equalizer 2 is disposed outside a clock extraction loop formed by an interpolator 3, a timing recovery circuit 4, and a control circuit 5. The digital equalizer 2 is provided between an A/D converter 1 and the interpolator 3 and performs equalization processing on digital playback data from the A/D converter 1 in accordance with the timing of a fixed clock CLK from a synthesizer 7. The coefficients of the digital equalizer 2 are updated by the control circuit 5 by using a coefficient setting device 6 according to frequency ratio information 4a from the timing recovery circuit 4. Accordingly, the clock extraction capability is enhanced in spite of the equalization processing on the playback signal by the digital equalizer.

Abstract: A bias loop is provided for automatic threshold level adjustment in data detectors, such as a slicer detectors or threshold detectors. The bias loop monitors characteristics of the data detector's output, such as its digital sum value, to generate a signal correction term, which is used to adjust the detector's input. Alternatively, the bias loop may adjust the data detector's actual threshold value.

Abstract: An optical disc recording/playback apparatus is provided with a first AD converter 35 for shaping a push-pull signal 14 detected from an optical disc medium 1 by a light difference signal shaping circuit 21, and converting the signal into a digital sampling signal 38 using a sampling clock 37 synchronized with a channel frequency; a series of means for detecting wobble amplitude information 77 during recording from the digital sampling signal 38; a series of means for detecting address polarity information 60 and address position information during playback; and a recording laser power control circuit 113 for controlling a recording laser power to a power suited for recording on the basis of the wobble amplitude information.

Abstract: An input sampling circuit for processing a disc read back signal to generate a digital signal includes an auto gain control (AGC) unit for adjusting a gain value of the disc read back signal, a low-pass filter/equalizer (LPF/EQ) coupled to the AGC unit for low-pass filtering/equalizing the disc read back signal to generate an output signal, and an analog-to-digital converter (ADC) coupled to the LPF/EQ for performing analog-to-digital conversion on the output signal across a conversion range that is narrower than a dynamic range of the output signal to convert the output signal into the digital signal.

Abstract: An optical recording medium having a track on which data has been previously recorded, comprising on the track a plurality of data block regions each of which includes main data of a block which is divided into a predetermined number of main data pieces, each of which has data for identifying the main data, and linking regions each of which has pseudo data and is inserted between the data block regions. When the linking regions on said track are adjacent, recording patterns of the pseudo data of the adjacent linking regions are different from each other. Further provided is a recording apparatus forming the data block regions and linking regions on a recording medium.

Abstract: An optical disc reproducing device is provided which is capable of setting an optimum PR class for the comprehensive frequency characteristic of an optical disc including the recording characteristic and reproducing characteristic. An optical disc reproducing device according to the present invention relates to an optical disc reproducing device which performs reproduction from an optical disc using the PRML method. The optical disc reproducing device comprises a Viterbi decoding unit which generates binary data using maximum likelihood decoding processing based upon multi-value reproduced data obtained by sampling a reproduced signal from the optical disc. The Viterbi decoding unit generates the binary data based upon an optimum PR class determined based upon the multi-value reproduced data and the binary data in a predetermined determination period.

Abstract: A phase difference detection circuit that is formed by digital circuits having a small circuit area. In the phase difference detection circuit, the circuits for generating a tracking error signal are structured by digital circuits, and a digital tracking error signal TE is generated from digital signals output from comparators. The latest previous phase difference data are stored in a phase difference memory, and a phase difference window PW is defined from the average phase difference calculated from the stored phase differences.

Abstract: A method and apparatus in an optical disk system employing a look-ahead data detection technique is described where an optimum detection is achieved with a minimum hardware complexity. In one embodiment, the boundary functions and the corresponding boundary decisions are derived for next state determination using only the minimum distance event pair for each state over the look-ahead samples, thereby reducing the detector hardware significantly relative to the Viterbi counterpart where the most likely occurring path is searched at every state. Depending on the sample quality, the limits for the boundary decisions can be programmable to combat the channel impairments like misequalzation, signal asymmetry, etc.

Abstract: In an information recording, a first data processor divides input data into a plurality of frames so as to arrange the plurality of frames for each unit block. The unit block is a unit of error-correction with respect to the input data and the frames include first identification information, respectively. A second data processor inserts a linking block on a boundary portion between unit blocks in the record data. The unit blocks are adjacent to each other. The linking block includes a second identification information and the second identification information is different from each of the first identification information. A controller controls to record the unit block and the linking block on the information recording medium.

Abstract: The statistical circuit includes a pulse-width measuring unit, serially coupling delay units, a logical circuit and counters. The pulse-width measuring unit is for receiving a sampling signal and generating a pulse-width signal. A pulse occurs on the pulse-width signal as the sampling signal has status change. The delay units include a first delay unit for receiving the pulse-width signal and outputting delay signals according to the trigger of a reference clock. The output of the first delay unit is used as a reset signal. The logic circuit is for receiving the pulse-width signal and the reset signal and generating a counting signal. The counting signal is enabled for a period of time as a pulse occurs on the pulse-width signal. The counters are respectively for receiving the delay signals and counting the number of the received delay signals in a first status as the trigger signal is enabled.

Abstract: In an information recording, a first data processor divides input data into a plurality of frames so as to arrange the plurality of frames for each unit block. The unit block is a unit of error-correction with respect to the input data and the frames include first identification information, respectively. A second data processor inserts a linking block on a boundary portion between unit blocks in the record data. The unit blocks are adjacent to each other. The linking block includes a second identification information and the second identification information is different from each of the first identification information. A controller controls to record the unit block and the linking block on the information recording medium.

Abstract: In an information recording, a first data processor divides input data into a plurality of frames so as to arrange the plurality of frames for each unit block. The unit block is a unit of error-correction with respect to the input data and the frames include first identification information, respectively. A second data processor inserts a linking block on a boundary portion between unit blocks in the record data. The unit blocks are adjacent to each other. The linking block includes a second identification information and the second identification information is different from each of the first identification information. A controller controls to record the unit block and the linking block on the information recording medium.

Abstract: In an information recording, a first data processor divides input data into a plurality of frames so as to arrange the plurality of frames for each unit block. The unit block is a unit of error-correction with respect to the input data and the frames include first identification information, respectively. A second data processor inserts a linking block on a boundary portion between unit blocks in the record data. The unit blocks are adjacent to each other. The linking block includes a second identification information and the second identification information is different from each of the first identification information. A controller controls to record the unit block and the linking block on the information recording medium.

Abstract: In a method and apparatus for generating optimum write power, a control unit controls a write voltage generating unit to generate sequentially write voltages of different levels to drive an optical read/write head to generate different write powers so as to write data on a plurality of write intervals of an optical recording medium in sequence. Simultaneously, a detecting and computing circuit detects a peak value, a first level and a second level of a write reflected signal generated by each write interval for computation so as to obtain a first control parameter of each write interval, and detects a peak value, a bottom value and a direct current level of a read reflected signal generated during reading of each write interval for computation so as to obtain a second control parameter of each write interval, thereby generating an optimum write power based on optimal first and second control parameters.

Abstract: A recording and/or reproducing apparatus and method with signal quality determining device and a method thereof, with the signal quality determining device including a signal estimator determining a level corresponding to a sample value of the RF signal using binary data obtained from the RF signal and generating a selection signal corresponding to the determined level, a channel identifier classifying the sample value into a plurality of levels according to the selection signal and obtaining an average value of the sample values classified into each level, and a quality calculator outputting a signal quality value representing quality of the RF signal using each sample value output from the channel identifier and the average value of the sample values classified into each level. Accordingly, quality of an RF signal can be determined more exactly, and focus compensation, tilt compensation, detrack compensation, and recording signal optimization can be performed using the determined signal quality.

Abstract: The present invention discloses a mixed mode circuit for data slice with auto calibration and method thereof, which comprises a data slicer for converting an analog signal into a digital signal; a set of current pump for supplying a variable power supply; a microprocessor for controlling and adjusting the set of current pump; a digital sum value counter for performing an addition or a subtraction operation according to the result outputted by the data slicer; a digital signal processor for reading the internal values of the digital sum value counter and calculating the average of these internal values to obtain a parameter value. With the aforementioned structure, the invention integrates the mixed mode data slicer of analog and digital circuits so as to adopt the merits and eliminate the drawbacks of the pure analog and digital data slicer and thus achieves the objective of reading data from an optical disk better and more accurately.

Abstract: A device for processing a radio frequency (RF) signal of an optical disk drive includes a high-pass (HP) filter, an RF variable gain amplifier (VGA), an RF analog-digital converter (ADC), and a digital module. The HP filter filters the RF signal and is capable of selectively utilizing one of a first cut-off frequency and a second cut-off frequency. The RF VGA amplifies the filtered RF signal. The RF ADC converts the amplified RF signal into a digital code. The digital module is capable of executing a first function and a second function with the digital code. The HP filter utilizes the first cut-off frequency when the digital module desires to execute the first function, and the HP filter utilizes the second cut-off frequency when the digital module desires to execute the second function.

Abstract: The present invention provides a read channel and a drive capable of suppressing deterioration in performance of a PLL and a Viterbi decoder by using a DC component eliminating means capable of higher-speed operation than hitherto. The location of an edge is determined by using differential of a read signal, and a DC component is detected from the midpoint level of the edge. Detection of a pseudo-edge due to a long mark or space signal is prevented by limiting the absolute value of a maximum or minimum of a differential coefficient when the location of the edge is determined from the differential coefficient of the read signal. Internal operation of a DC component detector is controlled according to the state of the PLL and the magnitude of the DC component.

Abstract: A signal of a run-length-limited code is read out from a recording medium. The read-out signal is converted into a reproduced digital signal. A decoder subjects the reproduced digital signal to first decoding different from run length decoding to get a first decoded signal. Information bit streams are generated from the first decoded signal. The information bit streams are different in timing by 1-bit-correpsonding intervals. Run length decoders subject the information bit streams to run length decoding to get run-length-decoded bit streams respectively. Each of the run-length-decoded bit streams undergoes one of error correction and error detection. A decision is made as to which of the run-length-decoded bit streams is the smallest in error number on the basis of results of the one of error correction and error detection. The run-length-decoded bit stream being the smallest in error number is selected and outputted as a likeliest information bit stream.

Abstract: The invention relates to a recording or reproduction apparatus for optical recording media having means for increasing the resolution of a digital-to-analog converter (DA), such as, for example, a digital-to-analog converter (DA) which is provided in the servo regulating circuit of a recording or reproduction apparatus and has a smaller bit width than its digital data source (DD). In order to increase the resolution or precision of the digital-to-analog converter (DA), a method and a circuit arrangement are provided by means of which less significant bits (L) of the digital data source (DD) are quantized and the quantization result is added to the value of more significant bits (H) of the digital data source (DD) with the exception of the maximum value of the more significant bits (H) for the purpose of increasing the resolution of the output signal of the digital-to-analog converter (DA).

Abstract: A transversal filter subjects a reproduced signal to partial-response waveform equalization responsive to tap coefficients to generate an equalization-resultant signal. There is generated 0-point information representing whether or not the reproduced signal corresponds to a zero-cross point. A temporary decision device calculates a temporary decision value of the equalization-resultant signal on the basis of a PR mode signal, an RLL mode signal, at least four successive samples of the 0-point information, and at least four successive samples of the equalization-resultant signal. Calculation is made as to a difference between the temporary decision value of the equalization-resultant signal and an actual value thereof. An error signal is generated in response to the calculated difference. The tap coefficients of the transversal filter are controlled in response to the generated error signal. The partial-response waveform equalization is PR(a, b, b, b, a).

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 timing recovery method samples, equalizes and detects a signal reproduced from a recording medium and to output a detection signal, controls sampling positions based on a phase error between the equalized signal and the detection signal, and obtains likelihood information which is related to a bit having a probability of error which exceeds a predetermined value, based on the equalized signal. The control of the sampling positions is suppressed during a time which is based on the likelihood information.

Abstract: A data slicer includes a comparator coupled with an input signal and a reference signal for generating a sliced signal, a waveform generator for generating a calibration signal, a pulse extension device coupled to the comparator and the waveform generator for modifying the duty cycle of the sliced signal or the calibration signal to output, a charge pump coupled between the pulse extension device and a first node for charging and discharging the first node according to the signal output from the pulse extension device, a determining circuit for adjusting the data slicer according to the level change at the first node, and a feedback device coupled between the first node and the comparator for generating the reference signal.

Abstract: An optical recording medium having a track on which data has been previously recorded, comprising on the track a plurality of data block regions each of which includes main data of a block which is divided into a predetermined number of main data pieces, each of which has data for identifying the main data, and linking regions each of which has pseudo data and is inserted between the data block regions. When the linking regions on said track are adjacent, recording patterns of the pseudo data of the adjacent linking regions are different from each other. Further provided is a recording apparatus forming the data block regions and linking regions on a recording medium.

Abstract: A disk drive device capable of satisfactorily detecting address information recorded by land prepits even after data is recorded is provided. When address information recorded by land prepits is detected from a disk on which lands and grooves as recording tracks are formed and address information is recorded as land prepits on the lands, a window signal is generated by binarizing a push-pull signal (window generation circuit 31), the push-pull signal is integrated in a period based on the window signal (integration circuit 32), and the address information by the land prepits is extracted from the integrated signal (33, 34, 35, and 26).

Abstract: An optical storage device and a blank detection method thereof are disclosed. An RF signal is obtained from an optical disc. A various gain amplifier amplifies the RF signal based on a control signal. An analog to digital converter samples the amplified RF signal to obtain a data signal. An auto gain controller updates the control signal based on amplitude of the data signal. A blank detector detects blankness of the data signal based on a threshold. The threshold is provided by a threshold generator based on the control signal. If the amplitude of the data signal does not exceed the threshold, the blank detector sends a hold signal to suspend update of the control signal.

Abstract: An error pulse is generated from a PRML circuit, and reproduction compatibility with a conventional apparatus is established. After a reproducing signal output from an optical head is equalized by an analog equalizer, sampled by an A/D converter at every clock, and digitally equalized by a FIR filter, the signal is binarized by a PRNL decoder. On the other hand, with regard to an error pulse, a level at an edge point is detected from an output signal of the A/D converter by an edge level detector, and the level at the edge point and an error pulse detection threshold are compared by an error pulse generator, and the error pulse is generated. Even when an optical apparatus having a trial writing function using conventional error pulse is provided with a PRML reproducing system for enabling high speed, the optical apparatus can execute trial writing using the error pulse as it is.

Abstract: A wobble signal is generated from at least two elementary signals (A,B,C,D) detected by scanning a wobbled track of a data carrier. The invention proposes a solution for eliminating the noise of various origins in the wobble signal, notably the high frequency data leakage into the wobble signal due to radial asymmetry introduced in the diffraction pattern on the detector, whatever the reason for this radial asymmetry. According to the invention, the at least two elementary signals are filtered with at least an adaptive filter (40), and said filtered elementary signals are subtracted (44) from said wobble signal (PP) thereby generating an improved wobble signal.

Abstract: A quality-testing apparatus is disclosed for an optical disk of the type that stores optically readable information in the form of a spiral or annular pattern defining a plurality of essentially concentric tracks. The apparatus has a laser light source and a drive mechanism which projects a laser beam spot from the laser light source onto a surface of the optical disk and moves the projected laser beam spot radically over a portion of the disc surface across at least some of the tracks. A light detector detects a reflection from the projected laser beam spot during its movement. The light detector produces a time variant measurement signal (HF) being associated with passages of the moving laser beam spot across respective tracks. A processing device measures the signal amplitude of selected parts of the optical disk and provides an output comprising key parameters such as symmetry and relative signal strength for the annular pattern of pits and lands.

Abstract: The recording strategy is optimized by determining a pulse response so as to minimize the difference between the reproduced waveform obtained by recording and reproducing the recording pulse signal wherein the record data is superposed with a high-frequency pulse and the waveform calculated by convolution of the record data and pulse responses. In this process, a single recording pulse waveform is recorded on a single track of the optical recording medium for three or more times, and sampled values zp,1, . . . , zp+3,1, . . . , . . . , zp,2, . . . , zp+3,2, . . . , zp,3, . . . , zp+3,3, . . . , of the reproduced waveforms reproduced therefrom are averaged in the order of the sampling to be used as the data for the reproducing waveform. Here, the first suffix for z represents the order of the sampling, whereas the second suffix represents the number of iterated times. The use of the averaged data can remove the influence by the random noise on the reproduced waveform.

Abstract: An optical information recording/reproducing apparatus is adapted to record and/or reproduce multilevel information on/or from an optical information recording medium. The multilevel information is recorded in the form of pits in cells virtually formed at regular intervals on a track. The respective levels are represented by varying the length or the area of information pits such that a reproduced signal has a different amplitude level depending on the length or the area of information pits. A reproduced signal correction circuit corrects a reproduced signal obtained by performing sampling at the center of each cell. An error power calculation circuit calculates error power on the basis of the difference between the corrected reproduced signal and an ideal value of each level of the cell. A decoder performs decoding on the basis of the calculated error power values.

Abstract: An adaptive level-cutting method of a radio frequency ripple signal for a CD-ROM drive is proposed. A digital signal processor is added to accomplish adaptive cutting of the central level of the radio frequency ripple signal for generating an accurate radio frequency zero cross signal, thereby accomplishing tracking control, short seeking control and long seeking control of an optical disc when regions with data and regions without data of the optical disc are staggered.

Abstract: A DVD audio data structure following high-sound-quality specifications is realized, making the best use of the audio data structure standard in DVD video. A first sample data string created by digitizing a first channel audio signal at a first sampling frequency in a first number of quantization bits, a second sample data string created by digitizing a second channel audio signal at a second sampling frequency in a second number of quantization bits, and header data including timing data to synchronize the first sample data string with the second sample data string are recorded on a recording medium.

Abstract: An optical disc reproducing apparatus includes an analog-to-digital (A/D) converter which converts an analog signal obtained from an optical disc to a digital signal; an asymmetry compensator which detects and corrects an offset of the digital signal; a phase locked loop (PLL) which estimates a clock of the digital signal and compensates for a frequency error; a binary module which converts the digital signal to binary data; an equalizer which equalizes a particular frequency of the digital signal; and a channel identifier which detects a reference level of the binary module, based on an input signal of the equalizer.

Abstract: A sample-and-hold interface circuit of a pickup head uses a circuit switch to control a voltage divider. When the circuit switch receives a signal Break, a voltage divider does not consume extra power to decrease the driving power consumption of a pickup head. And a controller can sample an unattenuated input signal to increase the signal/noise ratio.

Abstract: An encoded-bit-string generating unit generates a bit string encoded by scrambling an input bit string. A direct-current-component evaluating unit selects a bit string having a predetermined width in the bit string generated by the encoded-bit-string generating unit, while shifting bits one by one, and evaluates the direct-current component in the selected bit string. A bit-string extracting unit extracts a bit string with suppressed direct-current component, based on a result of an evaluation by the direct-current-component evaluating unit.

Abstract: An optical recording system includes a laser light source that provides an incident recording light signal for recording information on an optical recording medium, an optical detector for detecting a reflected write pulse from the optical recording medium, and a light source controller for controlling recording laser beam power of the laser light source according to a mark formation effectiveness signal generated by a signal generating device. The signal generating device includes an analog peak value detector for detecting a peak value of the reflected write pulse from the optical detector, at least one sample-hold circuit for sampling the reflected write pulse to obtain at least one amplitude value, and a processor for generating the mark formation effectiveness signal according to the peak value and the amplitude value.