Abstract: In an information recording method and apparatus, a sequence of sync frames indicative of data is recorded onto tracks of an optical recording medium. In the recording medium, prepits are formed on lands between the tracks at given intervals, and sync patterns, providing synchronization on a sync-frame basis, are inserted in the sync frames such that each sync pattern has a length in a track direction larger than a length of one of the prepits and a position of each sync pattern matches with a position of at least one of the prepits. Codes that represent sync patterns for the sync frames are selected such that each sync pattern is formed as a space on the recording medium. Modulation codes are generated based on the sync frames in which the selected codes are inserted, by modulating the sync frames containing the selected codes in accordance with a predetermined modulation scheme. A sequence of recording pulses is generated by converting the modulation codes through a predetermined conversion scheme.

Abstract: A PLL clock generator generates an output signal with a frequency N times (where N?1) as high as that of an input signal. The clock generator includes: a frequency divider for dividing the frequency of a clock signal by N so as to output a frequency-divided clock signal; a phase comparator for detecting a phase difference between the input signal and the output signal of the frequency divider so as to output a phase difference signal including information representing the phase difference; a LPF for smoothing the phase difference signal; a VCO for generating the clock signal, of which the frequency is determined by the output of the LPF, and outputting the clock signal to the frequency divider; and a phase shifter for shifting the phase of the output signal of the frequency divider in accordance with the phase difference signal.

Abstract: In a demodulation process of a first modulated signal and a second modulated signal, phase adjustment is automatically performed by generating, in response to demodulation results, an optimum phase value of a second internal reference wave for demodulating the second modulated signal. A phase of a second internal reference wave for demodulating the first modulated signal is also adjusted using the optimum phase value for the automatic adjustment.

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 signal output method for reducing jitter and forming pits having stable shapes on an optical information recording medium with high recording density is provided. A write signal includes a write permission signal including a repetition of write enable and pause intervals, and a write data signal outputted during the write enable interval. The write signal satisfies the formula Tfmax?Tfmin?0.01T, where Tfmax is an output interval of a first write data signal among write data signals corresponding to a write permission signal immediately subsequent to a pause interval when the pause interval of the write signal is a maximum, Tfmin is an output interval of a first write data signal among write data signals corresponding to a write permission signal immediately subsequent to a pause interval of the write signal when the pause interval of the write signal is a minimum, and T is a reference period.

Abstract: A PLL circuit includes a wobbling detector for detecting a wobbling signal based on reflection light of an optical disk having a wobbled track, and a VCO that an oscillation frequency of its output varies according to its input. The PLL circuit controls the VCO based on a phase error between the output of the wobbling signal and the output of the VCO. In the PLL circuit, the phase error is detected by executing an arithmetic operation to the delta-sigma modulated wobbling signal at a predetermined clock and the output of the VCO.

Abstract: A wobble signal extraction circuit for extracting a wobble signal from a first optical disk signal containing a wobble signal component caused by a wobble formed on a surface of an optical disk and a second optical disk signal containing a wobble signal component of a reversed phase to that of the first optical disk signal, wherein signal level fixing sections (24a; and 24b) fix the first and second optical disk signals to a predetermined level when a discontinuity of the wobble is detected.

Abstract: In an optical disc in/from which data is recorded or reproduced by irradiating a storage area on the optical disc with a laser, information containing recording velocity information (RVI) for recording/reproduction, which represents a linear velocity different from the standard linear velocity, and write strategy information (WSI) corresponding to the recording velocity information is stored in a land pre-pit or the like on the optical disc.

Abstract: A data phase locked loop circuit includes a phase locked loop circuit, a judging circuit, a detecting circuit and a control circuit. The phase locked loop circuit outputs a reference signal according to a data signal, which is generated by an optical drive reading an optical disk. When the judging circuit judges that a jitter signal is smaller than a threshold value, the control circuit stores a frequency of the reference signal. When the detecting circuit detects a defect zone of the optical disk read by the optical drive, the phase locked loop circuit fixes the frequency of the reference signal to a latest stored one.

Abstract: A method of determining the time for executing optimal power calibration in an optical drive. First, relationships between values of a driving signal and ambient temperatures of the optical drive are recorded in look up table in a memory. According to the look up table, mappings from the values of a driving signal output by a compensator to the ambient temperature of the optical drive can be obtained. When the ambient temperature of the optical drive is higher than a predetermined temperature, an optimal power calibration is executed.

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

Abstract: A demodulation method for magnetic data may include the steps of reading magnetic data with a magnetic head, generating a digital signal from a read analog signal, comparing an inversion time interval of the digital signal with a bit reference time interval, and generating bit data on the basis of comparing result of the digital signal. This demodulation method for magnetic data may further include a first step of comparing the inversion time interval of the digital signal with a bit lacking reference time interval which is set to be longer than the bit reference time interval, and a second step of discontinuing generation of the bit data when the inversion time interval of the digital signal is detected to be longer than the bit lacking reference time interval in the first step.

Abstract: A demodulator for demodulating an input signal including a predetermined modulated signal includes a multiplication fundamental wave generator for outputting a multiplication fundamental wave for the predetermined modulated signal, a calculator for multiplying the multiplication fundamental wave by the input signal and for integrating the multiplication result, a demodulated signal generator for generating a demodulated signal of the modulated signal using the output from the calculator, a phase determiner for determining a cross-phase state of the input signal and the multiplication fundamental wave on the basis of a balance of levels of a plurality of integrated values, obtained as the integration result, for an interval containing the modulated signal in the input signal, and a phase adjuster for adjusting a phase of the multiplication fundamental wave to be supplied to the calculator on the basis of the determination result of the phase determiner.

Abstract: A circuit for correcting a clock of a compact signal and a method therefor. The method comprises: receiving a data signal and a clock signal; and generating a sync pattern signal by using the clock signal to check the data signal. Then, a detection window signal according to a clock number during a timing of a last sync pattern signal and a first preset timing is generated, and the detection window signal having a second preset timing width. Finally, a clock of the sync pattern signal and the detection window signal are compared, and the clock signal is corrected.

Abstract: An apparatus and method detecting synchronization of address in pre-groove (ADIP), allowing an optical storage device to write data to an accurate location of a disc includes a bit synchronization detecting unit and a word synchronization detecting unit. The bit synchronization detecting unit determines synchronization of bits of the ADIP to be in a bit synchronization locked state when synchronization of raw bits is detected within a bit synchronization window having a first predetermined period a first predetermined number of consecutive times. The word synchronization detecting unit determines synchronization of words of the ADIP to be in a word synchronization locked state when synchronization of raw words is detected within a word synchronization window having a second predetermined period the first predetermined number of consecutive times.

Abstract: Stable playback performance is assured and data loss due to out-of-step synchronization is reduced even when playback signal quality deteriorates due to such cause as a recording medium defect. The playback method applies to a recording medium to which data is recorded in block units containing multiple fixed-length frames together with block address information. The data and the block address information are acquired from the recording medium. The recording position of each frame in a block is then predicted from the acquired block address information. Synchronization is then set to the frame level based on the acquired data, and the memory address for storing the acquired data is determined based on the predicted recording position. The acquired data is then stored at the determined memory address.

Abstract: A method for processing signals in a disk drive is provided. In the provided method, an RF signal is read at a predetermined highest reading speed, whose amplitude is adjusted with a gain. Then the level of the RF signal is adjusted by an equalizer with a predetermined parameter module. The RF signal is output if it could be read correctly. If failing to be read correctly, the amplitude of the RF signal to be read is checked. If the amplitude of the RF signal is not within a predetermined range, the gain is adjusted and then the step of reading the RF signal is re-proceeded and the procedures thereof are repeated. A further parameter module is applied by the equalizer if the amplitude of the RF signal is within the predetermined range. The procedures of the provided method are repeated after the reading speed of the disk drive is reduced if all of the parameter modules are applied.

Abstract: A phase locked loop (PLL) for generating an output signal according to an input signal is disclosed. The PLL of the present invention includes a detector for generating a detection signal according to the logical difference between the input signal and a feedback signal, a signal mixer electrically connected to the detector for generating a control signal according to the detection signal and a mixing reference signal, a filtering device electrically connected to the signal mixer for generating an adjust signal according to the control signal, a controllable oscillator electrically connected to the filtering device for generating the output signal according to the adjust signal, and a frequency divider electrically connected to the controllable oscillator for generating the feedback signal and the mixing reference signal according to the output signal. The frequency of the output signal is at least twice the frequency of the input signal.

Abstract: The methods described herein are directed at securing information in storage media such as optical discs, magnetic disks or a combination thereof. In particular the methods describe embedding a first stream of data in a second stream of data by modulating the location of transition edges in the second stream of data. A method for writing data to a storage medium includes the steps of representing the raw (first) data to be written to the storage medium as a sequence of bits in a format appropriate for writing to a storage medium; representing second data (supplemental data) as a second sequence of bits and writing the first sequence of bits to the storage medium as a corresponding sequence of pits along a track, wherein the location of the pits along the track represents the stored first data, and while writing the first sequence of pits, modulating the locations at which transition edges of the sequence of pits are written to embed the second data in the sequence of pits.

Abstract: In simultaneous stream recording and playback, after playback catches up with real time live broadcast, a playback speed changing unit 2 smoothly changes a playback speed to single speed. Nevertheless, an output switching unit 4 continues to perform single-speed playback. During single-speed playback, a switching timing indicating unit 3 indicates a timing of switching to real time live broadcast to the output switching unit 4. Upon receiving the indication from the switching timing indicating unit 3, the output switching unit 4 switches its output to real time live broadcast. With this, in the case of catching-up playback, it is possible to prevent adverse effects caused by dropout of sound information at an instant when the output is changed from catching-up playback to real time live broadcast.

Abstract: A minimum buffer data amount and a minimum reproduction delay time are found from a line approximation graphic form approximating a media read line and used as a basis for determining whether or not data can be reproduced in a real-time manner from a recording medium at a requested reproduction rate. The media read line is a line expressing the change in cumulative amount of data read out from the recording medium. The minimum buffer data amount is the minimum of the amount of data stored in a buffer as data required in reproduction of the data in a real-time manner at the requested reproduction rate. The minimum reproduction delay time is the minimum of a reproduction delay time from the start of an operation to read out the data from the recording medium to the start of an operation to reproduce the data.

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: A circuit locks onto a frequency of data encoded on a medium, taking frequency variations in the physical travel of the medium into account. The circuit includes a disk locked clock (DLC) circuit having a synthesizer operating under digital control based on a feedback signal to produce a servo reference clock and a read reference clock that track frequency variations in the physical travel of the medium. A recovered clock signal is produced based on the servo reference clock and the read reference clock. A digital phase locked loop maintains a frequency lock of the recovered clock signal. An error measurement circuit is connected to the digital phase locked loop. The error measurement circuit produces the feedback signal for digitally controlling the digital logic circuit synthesizer to produce the servo reference clock and the read reference clock that track frequency variations in the physical travel of the medium.

Abstract: A high-definition optical disk and a high-definition optical disk drive, which record data on lands and grooves. Wobbles are formed in grooves and lands of an optical disk, and address information is embedded in the wobbles. The wobbles are formed so as to become in phase with each other in the grooves. An address of the land sandwiched between the grooves is detected from the wobble of the groove. When the wobble of the land is not an in-phase wobble but is of opposite phase, a gray code of the wobble is substituted with a binary address such that 0 is achieved when the gray code is converted into the binary address. As a result, even in the case of the wobble of opposite phase, the address information about the land is made coincident with address information about an inner-radius-side adjacent groove, thereby determining address information about the land.

Abstract: A disc recording and reproducing device disclosed herein comprises: a resuming section which resumes writing of record data; a first reproduction synchronization signal output section which reproduces the record data recorded on a recorded data region, sequentially extracts a synchronization signal from the reproduced record data, and outputs a first reproduction synchronization signal; a reliability judging section which only detects a frame having a period in accordance with a predetermined standard from the first reproduction synchronization signal, and outputs the frame as a reliability synchronization signal; a synchronization signal phase retaining section which outputs a retained phase signal that retains a phase of the frame of the reliability synchronization signal; a second reproduction synchronization signal output section which reproduces the record data recorded on an additional data region, sequentially extracts the synchronization signal, and outputs a second reproduction synchronization signal

Abstract: A synchronization circuit for an optical disc apparatus, which performs synchronization operation based on a playback signal of an optical disc, the circuit comprises a playback signal recovery timing detection circuit that detects timing corresponding to the recovery of the playback signal for a defect signal from a defect signal detection circuit, a delay counter that counts frame synchronization signals from timing at which loss of recorded data on the optical disc is not detected by the defect signal detection circuit, a delay determining circuit that determines whether a count of the frame synchronization signals by the delay counter has reached a predetermined delay count, and a circuit that starts the synchronization operation when informed by the delay determining circuit to the effect that the count of the frame synchronization signals has reached the predetermined delay count.

Abstract: The invention provides a disk playback device wherein a disk (1) is irradiated with a laser beam from an optical head (4) to reproduce signals from the disk, and which comprises an external synchronizing signal producing circuit (8) and a delay circuit (12) for producing a reproduction synchronizing signal providing reference timing at which a reproduced signal is detected by reading an output signal from the optical head (4), a circuit (7) for detecting the reproduced signal by reading the output signal from the optical head (4) based on the reproduction synchronizing signal, and a system controller (10) for determining an optimum phase for a normal reproduction operation by altering the phase of the reproduction synchronizing signal and executing a reproduction operation, the controller (10) being operable to make a phase adjustment for the reproduction synchronizing signal prepared by the delay circuit (12).

Abstract: The invention advantageously provides an apparatus and method for recovering clock signals extracted from prerecorded wobbled grooves formed in an optical storage medium such as a compact disk (CD), mini disk (MD) or digital video disk (DVD). A preferred embodiment of the method according to the invention primarily comprises the steps of extracting a series of wobble signals from the prerecorded information, demodulating the wobble signals for generating a series of demodulated clock signals, detecting a period for the clock signals, dividing each of the clock signals for acquiring a series of synchronization frames, generating compensating phases, and respectively adjusting the synchronization frames with the compensating phases for generating a series of phase compensated frames.

Abstract: Disclosed is a data search system for searching the data sync pattern by using a physical address or by detecting the falling edge of the blank area end. The data search system comprises a first data start indicator, a second data start indicator, a decision circuit, a window generator and a data sync pattern search circuit. The first data start indicator generates a first start search signal indicating a first start position. The second data start indicator generates a second start search signal indicating a second start position. The decision circuit selects to output one of the start search signals. The window generator generates a window interval starting from the start position. The data sync pattern search circuit searches a data sync pattern of the data in the window interval to determine the data following the data sync pattern.

Abstract: A laser driver drives a laser diode by producing a write strategy, that is, a recording waveform from a recording clock and a modulated signal. In one embodiment, a laser driver produces the waveform of a driving signal, which is used to drive a laser diode, using a record data signal that represents record data to be recorded on a recording medium. The laser driver comprises an internal clock production circuit that produces an internal clock synchronous with the record data signal, and a strobe circuit that strobes the record data signal according to the internal clock.

Abstract: A disk recording apparatus and method therefore including a boundary violation detector to determine whether a violation of a block boundary occurs on a disk by determining a phase difference between a block boundary signal and an encoding block synchronous signal.

Abstract: An adjusting method for a synchronous signal in an optical storage device is disclosed. The optical storage device produces a predetermined synchronous signal, and the predetermined synchronous signal normally is matched with the data synchronous signal of the data on the optical disc. The predetermined synchronous signal includes a number of predetermined synchronous impulses, and the data synchronous signal includes a number of data synchronous impulses. In the method, when the data synchronous signal is not matched to the predetermined synchronous signal, it is searched that whether or not a data synchronous impulse is outside of the predetermined window and another consecutive data synchronous impulse detected later by a distance of an image frame is detected. Also and, according to the data synchronous impulse, the predetermined synchronous impulse is adjusted, so that the data synchronous impulse is matched with the predetermined synchronous impulse.

Abstract: The present invention relates to an optical disc apparatus having a wobble signal detection circuit, an information recording method, adjustment apparatus and method for an optical disc apparatus, a fabrication method for an optical disc apparatus, and adjustment method and apparatus for a phase shift amount. In the present invention, a wobble signal based on wobbling of an information track is supplied to the input side of a filter circuit, and the current phase difference between input and output signals to/from an HPF+LPF path is detected. Then, the phase of a recording start timing signal is adjusted corresponding to the detected phase difference. As a result, it is possible to prevent adverse effect due to the phase difference in the filter circuit.

Abstract: A method for replacing a defective block with a good block in an optical disk allows data recording operations to be effectively performed. The method temporarily stores data that would have otherwise been recorded in a defective area of an optical disc in a temporary buffer. The method then stores the data in the temporary buffer in a spare area of the optical disc after the normal data recording operation is completed, or if the amount of data in the buffer exceeds a predetermined memory capacity. The method can continuously and quickly perform a general data recording operation, effectively avoid a system load increase due to frequent track movements on an optical disc, and appropriately record real-time data without the loss of data.

Abstract: In a slew rate limiter, a slew rate is limited so as not to pass a signal varying more abruptly than a wobble signal included in a difference signal generated by a differential amplifier, and this limited slew rate is used to process the difference signal to be outputted. That is, the slew rate limiter removes a signal varying more abruptly than a wobble signal included in a difference signal DIFO, and then outputs only the wobble signal. A DAC generates an offset voltage. An adder is used to add this offset voltage to the wobble signal from the slew rate limiter. The signal obtained by this addition as a slice level is compared by a comparator with the difference signal, thereby reproducing an LPP signal.

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: In a land pre-pit address demodulating device DM for detecting land pre-pit address information during recording to a DVD-R/RW-disc, a tracking error signal TE is muted by a first reference potential Vref1 during a period in which the tracking error signal TE is generated from a reflected laser beam having a power for recording a mark, an RF residual component is removed from the tracking error signal TE, and the tracking error signal TE from which the RF residual component has been removed is compared with a second reference potential Vref2, thereby detecting a land pre-pit address signal.

Abstract: A method and an apparatus for providing digital quality transmission of audio and non-audio information using low cost components and arrangement. The present invention provides for the transmission of the audio and non-audio transmission by first converting the data to conform to the CD standard format and conditioning the converted signal to thereby generate a conditioned EFM signal. The conditioned EFM signal is used to frequency modulate a carrier. By converting the audio and non-audio information to conform to the CD standard format, the present method provides a low cost means of transmitting the data with error detection and correction. Another aspect of the present invention relates to embedding the non-audio information in the SUBCODE block of the data frame according to the CD standard. The non-audio information may be unrelated to the audio information, and the audio and non-audio information may be transmitted to separate devices.

Abstract: There is provided an optical disc having preformed thereon a spiral wobbled track as a grove and/or land along with data is to be recorded. The track is wobbled for a series of predetermined signal units each composed of an FSK information bit part based on a waveform resulted from FSK modulation of information bit and a singe-frequency part based on a waveform of a single frequency. The FSK modulation uses two different frequencies of which the one is the same as the single frequency and the other is different from the single frequency. These different frequencies are in such a relation that each of them has an even number of wobbles and an odd number of wobbles alternately in a predetermined cycle.

Abstract: A data recorder for recording data that records data in a continuous manner regardless of interruptions. An encoder encodes data that is to be written to a recording medium. A synchronizing circuit synchronizes the data read from the recording medium with the encoded data when the writing of data to the recording medium is interrupted. A first retry determination circuit determines whether an address of the data read from the recording medium and an address of the data provided to the encoder match. A second retry determination circuit determines whether the timing for reading data from recording medium and the timing for encoding data match. A restart circuit restarts the writing of data to the recording medium based on the determinations of the first and second retry determination circuits.

Abstract: A controller for a data recorder for recording data that records data in a continuous manner regardless of interruptions. An encoder encodes data that is to be written to a recording medium. A synchronizing circuit synchronizes the data read from the recording medium with the encoded data when the writing of data to the recording medium is interrupted. A first retry determination circuit determines whether an address of the data read from the recording medium and an address of the data provided to the encoder match. A second retry determination circuit determines whether the timing for reading data from recording medium and the timing for encoding data match. A restart circuit restarts the writing of data to the recording medium based on the determinations of the first and second retry determination circuits.

Abstract: An optical disk and a method of recording data in the optical disk are provided. When data is overwritten on a recordable and/or reproducible optical disk, the method includes performing linking in front of a physical cluster from which overwriting starts. According to the method, when overwriting is performed on a portion of an optical disk in which data has been recorded, or when overwriting is performed on a portion including a defective area, linking is performed in front of the portion on which the overwriting is performed or behind the defective area, thereby realizing reliable data recording and reproducing.

Abstract: A control circuit for an optical disk drive includes a frequency detector, a phase detector, a low pass filter, a voltage-controlled oscillator (VCO), and a controller. The frequency detector and the phase detector both receive an eight-to-fourteen modulation (EFM) signal and a data phase-locked loop (DPLL) signal. The controller can calculate a target frequency and control the VCO to output the DPLL signal according to the target frequency. During a non-seek mode, the VCO outputs the DPLL signal according to output of the frequency detector, phase detector, and low pass filter. During a seek mode or when spindle speed of the optical disk drive changes, the VCO outputs the DPLL signal according to the target frequency. The controller further outputs charge pump currents for the frequency detector and the phase detector and sets an RF equalizer signal and a differential phase detector (DPD) equalizer signal according to the target frequency.

Abstract: A phase difference detection circuit (270) and a gain adjusting circuit (280) are provided in an optical disc recording apparatus (200). When the phase difference detection circuit detects a phase difference between an ATIP synchronization signal and a recording synchronization signal, this phase difference detection circuit activates an internal counter (271). Then, when phase difference information including a result of a counting operation performed by the internal counter is outputted from the phase difference detection circuit to the gain adjusting circuit, the gain adjusting circuit suitably adjust the frequency division ratio of a (1/N)-frequency-divider (242) according to the received phase difference information. Thus, the phase of a recording clock signal to be supplied from a PLL circuit (240) to a data encoder (260) through a frequency divider (250) is controlled.

Abstract: An information recording medium for recording main information and auxiliary information is provided. The auxiliary information is recorded on the information recording medium in a manner that edge positions of the pits or the recording marks indicating the main information are shifted either in a phase advancing direction or in a phase delaying direction along the track direction. A predetermined frequency is used to determine whether the edge position is shifted in the phase advancing direction or in the phase delaying direction in order to record the auxiliary information. The predetermined frequency is substantially consistently lower than ½ of a reference frequency of a recording clock for creating the pits or the recording marks and is higher than a response frequency of a PLL for generating a reproduction clock for reproducing the main information.

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: The present invention relates to a storage unit comprising: a channel control portion for receiving a data input/output request; a cache memory for storing data; a disk control portion for performing input/output processing on data in accordance with the data input/output request; and a plurality of disk drives for storing data, wherein at least two of the disk drives input data to and output it from the disk control portion at different communication speeds. Further, the storage unit has a plurality of communication paths provided to connect at least one of the disk drives in such a manner as to constitute a loop defined by the FC-AL fiber channel standards, so that the communication speeds can be set differently for these different communication paths.

Abstract: An information storage apparatus records, reproduces and/or erases information with respect to a recording medium. The apparatus includes a servo error generation detector for detecting a generation of a servo error based on at least one of servo signals including a focus error signal and a tracking error signal which are derived from output signals of a light receiving element, and a data recording resuming section for temporarily interrupting a data recording with respect to the recording medium, temporarily turning OFF a servo and then turning ON the servo again, to thereafter synchronize recording data to recorded data already recorded on the recording medium, and resume recording of the recording data continuing without a discontinuity to an end of the recorded data recorded immediately before the interruption of the data recording, when the generation of the servo error is detected while recording data on the recording medium.

Abstract: A method for controlling an optical drive to record data onto a disc. The optical recorder has a pick up head for emitting laser onto the disc to record data onto the disc. The method includes adjusting a write power and a write strategy of the optical drive according to a linear velocity of the disc when passing by the pick up head.

Abstract: There is generated a rhythm corresponding to a designated tempo and meter of a music piece to be recorded. Performance of a musical instrument is started at specific timing according to the generated rhythm, and the musical information resulting from the performance is recorded onto an MD (Mini Disk). The address on the MD read out when the performance of the music piece is started is retrieved as a start address of the music piece. After the recording, the retrieved start address is recorded onto the UTOC (User's-table-of-contents) area of the disk along with the designated tempo and meter. By reading out the start address, tempo and meter to calculate a measure number and start address of a desired measure on the basis of the read out information, display of a measure number being currently reproduced and quick access to the starting point of any desired measure can be achieved.