Abstract: A signal can be detected based on a level slice system and detection delay time can be reduced by setting the recording density of a header field in a linear direction lower (coarse) than that of a user data recording field. Further, a signal can be detected based on the level slice system and detection delay time can be reduced by using a mark position form having a large detection margin as an information recording system of the header field. A readout error of a sector number due to a detection error is compensated for by recording address marks AM for attaining byte synchronization of the header field in both of a head portion and tail portion of information recorded in the header field.

Abstract: A method (2) of controlling memory usage in a portable streaming device (100), a portable streaming device (100) and a computer readable medium (110). The portable streaming device (100) comprises at least one memory (102), at least one processing unit (101), and at least one storage device (103) being operatively connected with said memory (102) under control of said processing unit (101). The size of a disk scheduler buffer memory within said memory in said portable streaming device is adaptively maximised by said method (2) at all times. Free memory available within the portable streaming device is continuously allocated (50) and at least a portion of said allocated free memory is designated as disk scheduler buffer memory (60). Thus results improved solid state memory utilisation of the portable streaming device, and due to larger available disk buffer memory size, less start-stop-cycles of the storage device are initiated, which leads to a longer life-cycle of said portable streaming device.

Abstract: An optical recording method to be used for recording at a high data transfer rate length-modulated marks on a recording medium by applying a recording laser beam locally to the recording medium. The recording laser beam has a writing power Pwi, is and a bias power Pbi. A record mark has a length of nT. With respect to at least two record marks, a pulse dividing number m is at least 2, and with respect to all record marks with m being at least 2, 2.5 is smaller than or equal to n/m, in a case where plural different record mark lengths are to be respectively formed by the same pulse dividing number m.

Abstract: A signal can be detected based on a level slice system and detection delay time can be reduced by setting the recording density of a header field in a linear direction lower (coarse) than that of a user data recording field. Further, a signal can be detected based on the level slice system and detection delay time can be reduced by using a mark position form having a large detection margin as an information recording system of the header field. A readout error of a sector number due to a detection error is compensated for by recording address marks AM for attaining byte synchronization of the header field in both of a head portion and tail portion of information recorded in the header field.

Abstract: A method of adjusting channel properties of an optical storage system is disclosed to include the steps: Step 1) give a modify step, a trial step and a threshold, Step 2) give an initial point, Step 3) add an initial focus point to the trial step and measure the sum so as to obtain a first jitter value, Step 4) deduct the trial step from the initial focus point and measure the difference so as to obtain a second jitter value, Step 5) deduct the second jitter value from the first jitter value and judge if the difference is greater than the threshold or not, Step 6) deduct the modify step from the initial focus point and then return to step 3) when the difference obtained from step 5) is greater than the threshold, Step 7) deduct the first jitter value from the second jitter value and judge if the difference is greater than the threshold or not in case the difference obtained from step 5) is smaller than the threshold, Step 8) add the initial focus point to the modify step and then return to step 3) when the di

Abstract: A signal can be detected based on a level slice system and detection delay time can be reduced by setting the recording density of a header field in a linear direction lower (coarse) than that of a user data recording field. Further, a signal can be detected based on the level slice system and detection delay time can be reduced by using a mark position form having a large detection margin as an information recording system of the header field. A readout error of a sector number due to a detection error is compensated for by recording address marks AM for attaining byte synchronization of the header field in both of a head portion and tail portion of information recorded in the header field.

Abstract: A receiver is described for delivering a data sequence (ak) at a data rate 1/T from an analog signal (Sa), the receiver comprising: a) converting means (40) for generating a received sequence (rn) by sampling the analog signal (Sa) with a sample rate of 1/Ts, whereby the sample rate 1/Ts of the received sequence (rn) is controllable by a preset value (Pv); b) digital processing means (12) for delivering a processed sequence (yn) by processing the received sequence (rn); c) a first sample rate converter (13) converting the processed sequence (yn) into an equivalent processed sequence (ye) at the data rate 1/T, whereby the data rate of the equivalent processed sequence (ye) is controllable by a control signal (Sc); d) an error generator (14) for delivering an error sequence (ek) from the equivalent processed sequence (ye); e) a control signal generating means (15) for generating the control signal (Sc) dependent on the error sequence (ek); f) a detector (16) for deriving the data sequence (ak) from the equivale

Abstract: In a method of reproducing multilevel information, cell-boundary values are obtained. Each of the cell-boundary values is obtained when the center of a light spot comes at a boundary between adjacent cells. Then, on the basis of the cell-boundary values and prestored reference values for the cell-boundary value, cell-boundary-value metrics are calculated. Furthermore, on the basis of the cell-boundary-value metrics, path metrics are calculated.

Abstract: An apparatus and a method to accurately generate a bit clock synchronized with digital data. The apparatus includes an edge detecting unit, a first edge counter, a second edge counter, a first counter, and a bit clock generating unit. The edge detecting unit detects edges of the digital signal. The first edge counter counts a number of the detected edges during a first period. The second edge counter counts the number of the detected edges during a second period. The first counter is reset and counts a system clock if one of the edges is detected during the first period. The bit clock generating unit generates a bit clock based on a count value of the first counter or a channel bit interval, if one of the first edge count value and the second edge count value is equal to a first predetermined value.

Abstract: A signal can be detected based on a level slice system and detection delay time can be reduced by setting the recording density of a header field in a linear direction lower (coarse) than that of a user data recording field. Further, a signal can be detected based on the level slice system and detection delay time can be reduced by using a mark position form having a large detection margin as an information recording system of the header field. A readout error of a sector number due to a detection error is compensated for by recording address marks AM for attaining byte synchronization of the header field in both of a head portion and tail portion of information recorded in the header field.

Abstract: A laser beam from a pickup is focused on an information recording medium, such as a DVD-R/RW, to record information. When the power of the laser beam is calibrated, the laser beam emitted from the pickup is received by a light receiving unit such as an FMD. The level of the received laser beam is detected, the power ratio of the laser beam is determined based on the result, and the power of the laser beam is calibrated so that the power ratio matches a predetermined reference power ratio. This method enables information to be recorded with optimum recording characteristic because the reference power ratio shows the power ratio for recording information at the optimum characteristics.

Abstract: A controller (30) is capable of operating in two possible operative modes, each mode having a corresponding characteristic (11; 12). Said characteristics have an overlap in a range of error signal values [TLL–TN]. The controller is capable of switching from one mode to another, based on the value of the time-derivative (( ) of the input error signal (e), so that, for a certain input error signal within said range [TLL–TN], the controller can be in any of its modes.

Abstract: Embodiments of the present invention include first and second pulse trains input to a switch in synchronization. The first and second pulse trains may have a repeating high and low values at first and second frequencies, respectively, and the first pulse train may transition from the low to the high value with a first edge sharpness. The second pulse train input may have a lower than the first frequency. The switch may use a selection signal in synchronization with the first pulse train to select an output from the first or second pulse train to create an output pulse train appropriate to transition fault test an integrated circuit. The switch may switch from the second pulse train to the first pulse train and substantially maintain the first edge sharpness of the first pulse train during a low value of both the first and second pulse trains.

Abstract: A write strategy circuit and a write strategy method for capturing data are disclosed. A strategy clock generator generates a strategy clock signal based on a channel clock signal. A phase controller produces a capturing channel clock signal by controlling a phase of the channel clock signal in synchronization with the strategy clock signal. A data capturing circuit captures the data in synchronization with the capturing channel clock signal. A phase determination circuit determines whether a length of the data corresponds to a predetermined value. A strategy correction circuit applies a predetermined strategy correction to the data based on the strategy clock signal. In this case, the phase controller controls the phase of the channel clock signal based on a determination result of the phase determination circuit. An optical disk apparatus using the write strategy circuit or the write strategy method is also disclosed.

Abstract: It is an object of the present invention to provide a method of recording information to an optical recording medium that is suited to achieving high data transfer rates. The optical recording medium according to the present invention comprises a method of recording information to an optical recording medium where information is recorded by forming on the optical recording medium a plurality of recording marks selected from a group consisting of several types of recording marks each with different lengths, wherein a first recording mark and a second recording mark contained within said group are formed with the number of pulses and the pulse spacing in the laser beam set substantially equal to each other. Thus, even in the case that one clock period (T) is shortened to achieve high transfer rates, recording marks with good shapes can be formed. In addition, control is simplified and it is possible to reduce the cost of a drive to which the present invention is applied.

Abstract: An information recording method performing recording on an information recording medium having multiple rewritable recording layers each having a data area in which user data is to be recorded is disclosed. The method includes a recorded area presence or absence determination step that determines whether a recorded area exists in at least the data area of a first recording layer; and a corresponding unrecorded area data filling step that, if the recorded area exists in the first recording layer, records predetermined data in an unrecorded area in an area, corresponding to the same radial position as the recorded area, in a second recording layer except the first recording layer at a predetermined timing before completion of the recording on the information recording medium.

Abstract: Based on a recording signal, a recording pulse signal, which includes a top pulse located at a front end portion and having a first magnitude, a last pulse located at a back end portion and having the first magnitude, and an intermediate bias portion located between the top pulse and the last pulse and having a second magnitude, is generated. Based on the recording pulse signal, a light source is controlled, and a laser pulse is irradiated on a recording medium. Recording marks corresponding to the recording signal are formed on the recording medium. In generating the recording pulse signal, when the recording medium is rotationally driven, a position of the top pulse is shifted ahead of a position of the top pulse when the recording medium is rotationally driven at the first rotation speed, when the recording medium is rotationally driven at the second control speed.

Abstract: Method of recording control signals on a removable optically readable disc like recording device comprising recording control data representing the physical structure of an optically readable disc. The control data set either being a standardized set of control data corresponding to the record carrier or either being a non-standardized set of control data deviating form the standardized set of control data signals. Preferably the non-standardized set of control data relates to different values for the number of information layers present on the record carrier or the type of record carrier being of the read-only type, recordable or rewritable type. Preferably a user may select the non-standardized set of control data by selecting a corresponding type of playback and/or recording apparatus.

Abstract: When performing OPC, data including a plurality of first sequences and second sequences with specified contents are written onto the optical disk. A read result corresponding to the written data is then read. The read result is high-pass filtered such that effects corresponding to the second sequences are contained in a portion of the read result corresponding to the first sequences. Since the first sequences have specified contents, the portion of the read result corresponding to the first sequences are detected, and the beta-parameter is evaluated only according to the portion of the read result corresponding to the first sequences.

Abstract: An optical record carrier recording method forms pits and lands by directing a radiation beam (12) onto a recording surface (21) of an optical record carrier (20). The radiation beam for each pit to be recorded is set to at least one write power level (Pw) capable of forming a pit during a write power irradiation period (31) and, for each land between the pits, to at least one bottom power level (P0) incapable of forming a pit during a bottom power irradiation period (51).

Abstract: The invention provides a phase lock loop (PLL) in a controller of an optical disk system and methods therefor. According to a preferred embodiment of the invention, the PLL comprises a write phase detector, a read phase detector, and a common read/write module shared by the write and read phase detectors. Further according to the invention, the common read/write module comprises a read/write mode selector coupled to the write and read phase detectors, a charge pump coupled to the mode selector, a loop filter coupled to the charge pump, and a voltage control oscillator (VCO) coupled to the loop filter.

Abstract: A method and the related apparatus for performing optimal power control of an optical disk drive includes reading a write-in data from an optical disk and generating a corresponding read result after the write-in data is written onto the optical disk with the default power, and accumulating a beta parameter according to a portion of the filtered read result whose level is higher than a first level and lower than a second level. The first level is substantially higher than the second level.

Abstract: A signal processing circuit for eliminating noise from an input binary signal includes a measurement part and a signal output part. The measurement part measures the cumulative period of time of at least one of high-level and low-level states of the input binary signal for a predetermined period of time after the polarity of the input binary signal is inverted. The signal output part outputs at least one of high-level and low-level signals in accordance with the cumulative period of time.

Abstract: An optical recording power controlling apparatus and method, in which the determination conditions for received Non Return to Zero Inverted (NRZI) data and the varying range of the optical recording power level are set depending on the multiple-speed of recording and the type of an optical medium, and the varying range of the optical recording power level is controlled so that optical recording power provided to a light emitting device is optimal for the multiple-speed of recording and the type of an optical medium. In the optical recording power controlling apparatus, a system control unit sets the discrimination conditions of received data to be recorded and the varying range of the optical recording power level, depending on the multiple-speed of recording and the type of an optical medium.

Abstract: An optical disk device that records and reproduces information on/from a recordable optical disk is provided.

Abstract: An apparatus for generating a fingerprint of a digital medium having a partial decoder for generating a partially decoded form of a compressed datastream, feature extractor for extracting at least one invariant feature from the partially decoded form, a fingerprint calculator for computing at least one fingerprint from the extracted invariant feature. An apparatus for authenticating fingerprints and methods for generating and authenticating fingerprints.

Abstract: A key signals input apparatus and related operating method used for reducing chip I/O number is described. The key signals input apparatus has a plurality of keys and a signal conversion module. The signal conversion module converts key signals into an analog voltage before directing to the chip for further processing. An analog signal decoding module designed in the chip decodes the analog signal so as to recover a plurality of input key values such that the chip may perform further operations according to the indication of the key signals.

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. A time compensator determines the time delta between an initial write on the optical storage medium, such as formatting of the medium, and the current time, and then applies the time delta to determine a time compensation factor that adjust the write parameters of a focused laser beam that writes information to the optical storage medium.

Abstract: A write abort algorithm of a tracking and focus servo system that can abort a write operation on an optical disk drive is presented. The write abort algorithm monitors at least one of a tracking error signal or a focus error signal and indicates a write abort status when the tracking error signal or the focus error signal indicates a threshold value. In some embodiments, the write abort algorithms suspends indication of the write abort status in the presence of a defect, suspension of the write abort status occurs more than a predetermined number of times.

Abstract: A method and an apparatus establish manufacturer-specific test writing parameters for writing of a writable optical storage media in accordance with the media manufacturers, which are experimentally determined and stored into a certain storing unit; determine an optimum writing light power based on the determined optimum writing parameters; and write an input signal into the user's data region of the optical disk.

Abstract: An optical recording method for recording mark length-modulated information on a recording medium by using a plurality of recording mark lengths. The optical recording method comprises the steps of: when a time length of one recording mark is denoted nT (T is a reference clock period equal to or less than 25 ns, and n is a natural number equal to or more than 2), (i) dividing the time length of the recording mark nT into ?1T, ?1T, ?1T, ?2T, ?2T, . . . , ?iT, ?iT, . . .

Abstract: It is an object of the present invention to provide a method of recording information to an optical recording medium that is suited to achieving high data transfer rates. The optical recording medium according to the present invention comprises a method of recording information to an optical recording medium where information is recorded by forming on the optical recording medium a plurality of recording marks selected from a group consisting of several types of recording marks with different lengths each corresponding to n times (n is a natural number) the clock frequency T, wherein: taking Tr to be the transition time required for a laser beam to rise and Tf to be the transition time required for the laser beam to fall, said recording marks are formed using a laser beam made up of a number of pulses given by nT/(Tr+Tf) or less.

Abstract: A program product is used by a control computer of an optical disc apparatus. The apparatus accesses plural types of optical discs. The control computer recognizes one type of optical disc out of the plural types of optical discs based on history information including a type of optical disc used in times past according to the program. The control computer then judges whether the type of set optical disc is identified with the recognized type of optical disc.

Abstract: A method for recording information on a rewritable recording medium includes recording first synchronizing signal information in a first synchronizing signal portion on the rewritable recording medium, recording second synchronizing signal information in a second synchronizing signal portion following the first synchronizing signal portion on the rewritable recording medium, recording data information in a data portion of the rewritable recording medium after the second synchronizing signal portion by forming marks in the data portion. The data information corresponds to both ends of each the marks. The marks and spaces between the marks are substantially randomly inverted each time the information is recorded and a length of the first synchronizing signal portion changes and a start position of the first synchronizing signal portion changes. A change of the start position of the first synchronizing signal portion is smaller than a change of the length of the first synchronizing signal portion.

Abstract: A recording medium includes first information selected from a plurality of information patterns and second information selected from another plurality of information patterns for the true-false judgement. A true-false judging device performs a statistic analysis when any coincidence is found between the readout combination of the first and second information and registered combination patterns, to identify an inspected recording medium as a forged product based on the result of the statistic analysis.

Abstract: An apparatus has a plurality of rotary heads for reproducing digital data from a recording medium, and delays a reference signal phase-locked with the rotary heads on the basis of the detection output of predetermined reference data in the reproduced digital data, thereby generating a signal indicating the reproducing start timing of the digital data by the plurality of rotary heads.

Abstract: An optical disc player discriminates an attribute of tracks recorded onto a disc inserted in the player, and normally reproduces MP3 tracks recorded onto discs inserted into a plurality of disc drivers using an MP3 decoder. Also, according to a method of reproducing an optical disc, the optical disc player discriminates a kind of an inserted disc as an audio file disc, an MP3 file disc, or a general data file disc and normally performs a reproducing operation for the files or music recorded onto the inserted disc.

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 disk apparatus for recording test data onto an optical disk while changing the level of recording power and determines the optimum recording power with reference to the quality of a reproduced signal of the test data. A modulation degree or a ? value is calculated from a reproduced signal of the test data, and the gradient of a change of the modulation degree or the ? value relative to the recording power Pw is calculated. Further, a target recording power is determined utilizing an area where the gradient of the change is relatively sharp, and the optimum recording power is determined based on the target recording power.

Abstract: An apparatus which records/reproduces data with respect to an optical recording medium, includes a data processing unit which detects a phase difference between a phase reference signal and a groove wobble signal detected from the optical recording medium, and compensates for the phase difference and performs a signal processing to record data on or reproduce data from the optical recording medium in response to the phase difference being equal to or greater than a predetermined reference value. By detecting a phase difference between a phase reference signal and a wobble signal and compensating for the phase difference, a recording of data on and a reproducing of data from the optical recording medium can be more accurately performed.

Abstract: The invention relates to a method and recording device for selecting an optimal write strategy for a specific type of optical recording disk. Such an optimal write strategy is selected even when the optical recording disk is of a type that has not been previously encountered or when the optical recording disk is otherwise unrecognized by an optical disk drive. The optimal write strategy and associated settings are selected from a set of write strategies stored in a disk drive. The disk drive bases its selection of the write strategy on the performance results of test writings conducted on the optical disk. The method entails testing the write strategies first at the maximum possible write speed and if necessary, at successively lower speeds until a write strategy that achieves a minimum acceptable write quality is identified or until the minimum write speed is reached. The selected optimal write strategy may be stored in the recording device or, alternatively, on the optical recording disk itself.

Abstract: An optical disc having marks for dispersed addresses that can be easily detected with high precision. A dispersed address comprises synchronization marks, positive marks, and negative marks. Synchronization marks, positive marks, and negative marks are formed along a groove as partial discontinuities or partial modifications in the wobbled groove.

Abstract: An optical information recording method records information with respect to an optical information recording medium having a multi-layer structure recording layer formed by a plurality of recording layers each capable of recording information, and carries out an Optimum Power Control (OPC) prior to carrying out the recording. Recording conditions that are used when carrying out the OPC are read from one of the recording layers of the optical information recording medium to which the recording is to be made, where each of the recording layers is recorded with the recording conditions therefor, and the OPC is carried out using the read recording conditions.

Abstract: A laser diode drive circuit for an optical disc recording and/or reproducing apparatus includes a plurality of laser diodes to output laser beams having different wavelengths, a switch circuit for selectively connecting a required laser diode from a plurality of laser diodes, a laser diode drive power supply circuit for driving the laser diode selectively connected by the switch circuit, a photodiode for detecting at least part of laser beams emitted from the laser diode to convert a detected part of laser beams into an electrical signal, a plurality of current-to-voltage conversion amplifiers connected to an output of the photodiode and whose conversion resistance values can be adjusted and having differently designed center conversion resistance values and an automatic power control circuit connected to outputs of the current-to-voltage conversion amplifiers to output a feedback signal to the laser diode drive power supply circuit.

Abstract: A disc drive device optimally controls a speed for reading RTR-format data, such as video and audio, recorded on a DVD-format disc, thereby enabling real-time playback without interruption. In the disc drive device, information added to each sector is used for determining whether data is RTR-format data. When an error occurs at high-speed reading of RTR-format data and therefore the reading speed is changed to a low speed, the reading speed is so controlled as to be kept at the low speed for reading the following RTR-format data. Thus, for RTR-format data, overhead due to repetitive acceleration and deceleration processes can be avoided, and reading can be carried out without interfering with real-time playback. For normal data, reading can be carried out in a manner similar to that in the background art.

Abstract: First and second synchronous words having respective numbers of times of inversion different from each other in NRZI conversion are generated in a synchronous word generation portion, and first and second code word series data are generated by arranging code word data generated making reference to a run-length coding table after these two synchronous words. With respect to the first and second code word series data, DSV calculation results stored in two DSV calculation peak value memories corresponding to these data are compared with each other by a peak value comparison portion. Based on a comparison result, the code word series data having a smaller direct-current component generated in NRZI conversion is selected.

Abstract: A signal can be detected based on a level slice system and detection delay time can be reduced by setting the recording density of a header field in a linear direction lower (coarse) than that of a user data recording field. Further, a signal can be detected based on the level slice system and detection delay time can be reduced by using a mark position form having a large detection margin as an information recording system of the header field. A readout error of a sector number due to a detection error is compensated for by recording address marks AM for attaining byte synchronization of the header field in both of a head portion and tail portion of information recorded in the header field.

Abstract: Compressed audio data for 5.1 channels stored in the DVD-ROM 11A is read by the AC-3 decoder 12 of a pseudo multi-channel stereo play-back apparatus and, after expansion, stored temporarily in a buffer 13, channel by channel. Among stored audio data stored in the buffer 13, audio data for left and right channels and for a front center channel are then subjected to the phase transformation. Audio data for left and right front channels are mixed with the phase transformed audio data by first and second mixing circuits 21 and 22 and mixed audio data are converted into analog audio signals by first and second D/A converters. The apparatus is capable of pseudo reproduction of the multi-channel audio signals stored in a recording medium such as a DVD-ROM by two channel play-back with an excellent sound effect which is not obtainable by usual two-channel play-back systems.

Abstract: In a digital data reproduction apparatus for demodulating digital data from an optical recording medium, PRML (Partial Response Maximum Likelihood) signal processing effective to high-density recording/reproduction is carried out by using a half rate processing offset control means which performs data demodulation using half of the channel bit frequency, a half rate processing phase sync control means, a half rate processing adaptive equalization means, and a half rate processing maximum likelihood decoder, and the digital data recorded on the optical recording medium are reproduced while restoring signal components which are missing in the time direction, by linear interpolation or Nyquist interpolation. Therefore, digital data reproduction performance is improved, and power consumption is reduced.

Abstract: A device for demodulating position information that is recorded as track wobbling in a record medium by a BPSK scheme includes a carrier-wave-generation circuit which derives a carrier wave from a wobbling signal obtained from the record medium, a phase-adjustment circuit which generates a phase-comparison signal having a 90° phase difference relative to the carrier wave, a multiplier which multiplies the wobbling signal and the phase-comparison signal to supply a product signal, and a detection circuit which detects a phase error of the carrier wave introduced by the carrier-wave-generation circuit by detecting the phase error between the wobbling signal and the phase-comparison signal based on the product signal.