Abstract: An optical information recording medium is provided with a plurality of information layers (2, 3), each of which has a sector structure in which a data area (8, 12) is divided in the circumferential direction by a sector address (9, 13). The positions of the sector addresses (9, 13) of the respective information layers (2, 3) coincide in the circumferential direction. This can prevent errors during reproduction caused by the effect of other information layers and stabilize recording characteristics, resulting in an increased recording capacity of a rewritable recording medium having a plurality of information layers with a sector structure.

Abstract: A decoder for decreasing the load on a microcomputer. The decoder stores in a buffer memory in sector units digital data. The decoder includes a check head register for storing a first address of the buffer memory when storing the processed digital data in the buffer memory. A check sector counter counts the number of sectors of the processed digital data stored in the buffer memory to generate a count value. A command decision circuit decides whether digital data requested to be transferred is stored in the buffer memory based on the first address, the count value, and a head address of the digital data. The command decision circuit permits the decoder to transfer the processed digital data when deciding that the digital data requested to be transferred is stored in the buffer memory.

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: An optical disk playback apparatus for playing back or reproducing main data and its associated sub-code which are read from an optical recording medium comprises an interleave RAM for storing the main data. The optical disk playback apparatus performs a predefined synchronization protection on synchronization information included in the sub-code to generate a sub-code synchronization signal which is written into an empty area of the interleave RAM, and manages the addresses with a FIFO area in a manner similar to the main data, thereby causing the read sub-code synchronization signal to function in synchronization with the main data.

Abstract: A recording medium includes a plurality of signal recording layers. A head reproduces two information signals from respective places in the recording medium on a time sharing basis. The reproduced signals are stored in a buffer memory before being outputted therefrom at first and second transfer rates respectively. The reproduced signals are transmitted from the head to the buffer memory on a time sharing basis and at a third transfer rate higher than the first and second transfer rates. Information amounts of the respective reproduced signals continuously transmitted from the head to the buffer memory are decided on the basis of a given relation among parameters including intra-layer seek times and inter-layer seek times related to the head, and the first, second, and third transfer rates.

Abstract: This invention provides a method and a system to read and buffer an audio data file from an optical storage medium into a buffer memory. The data file comprises blocks sequentially stored in the medium. Each block comprises a subcode block with encoded subcodes and a corresponding main data block with encoded audio data. The method first designates a starting block where buffering starts and searches for the starting block in the blocks. After the starting block is searched, trigger a main data block decoding procedure to decode the starting block and main data blocks in later blocks. According to the timing when the main data block decoding procedure is triggered, decide the timing to trigger buffering the decoded subcodes to the buffer memory. Therefore, the subcodes and corresponding audio data belonging to the same block before decoding can be buffered into the same buffer unit after decoding.

Abstract: A data recording controller for speedily modulating input data and generating modulated data. The controller includes a modulation circuit for modulating input data and generating modulation candidates. A selection circuit is connected to the modulation circuit to receive the modulation candidates from the modulation circuit and select one of the modulation candidates as the modulated data based on a conversion parameter. A plurality of memories simultaneously store the modulation candidates, respectively. An output circuit receives the modulation candidates read from the memories and outputs the modulated data, which the selection circuit selects from the modulation candidates.

Abstract: The invention provides an optical disk recording and reproduction method which suppresses a drop of the throughput of an optical disk apparatus by retrying caused by a read error. A control section of an optical disk apparatus controls, if a read error occurs upon reading out of data from a first address of an optical disk by an optical head section, the optical head section to perform retrying of reading out from the first address. Each time retrying is performed, the control section records the number of times of retrying into a memory. Then, if reading out from the first address is performed successfully, then the control section reads out the number of times of retrying from the memory. If the number of times of retrying exceeds a prescribed number of times then the control section secures an alternative second address in place of the first address on the optical disk.

Abstract: A data recorder that prevents buffer underrun errors includes a buffer memory for temporarily storing data to be written to a recording medium and an address memory connected to a buffer memory. The address memory stores an address of the recording medium or an address of the buffer memory when data writing is interrupted. A synchronizing circuit sequentially reads data from the medium and data stored in the buffer memory prior to the interruption and synchronizes the read and stored data. A restart circuit restarts data writing when an address of data read from the medium or an address of data read from the buffer memory matches the address stored in the address memory.

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

Abstract: A method for data reproducing from an optical storage device. The method is used to improve the usage efficiency of buffer memory of the storage device. Date that is already transferred to the host computer is considered as “cache hit”. Thus, when data near one address is read again, the storage device need not do tracking, reading and decoding. Data in buffer memory is directly transferred to the host computer. It significantly improves the reproducing efficiency of the optical storage device.

Abstract: When a record decision unit 22 judges that recording has been interrupted, the recording data in a predetermined frame is ended. Data are continuously recorded onto a disk until the frame synchronous signal duration following the predetermined frame. Thereafter, the control output generated from the head output controller 14 is controlled to interrupt the recording operation. When the record decision unit 22 judges the resuming of recording, the control output from the head output controller 14 is controlled to resume the recording operation onto the disk from the frame synchronous signal duration in which the recording of data onto the disk has been interrupted.

Abstract: An apparatus and method for buffering NRZ data patterns in order to generate a recording pulse in a CD-RW/DVD-RW system are provided.

Abstract: An information playback apparatus which can perform random access playback, reverse playback, shuttle playback, etc. quickly and seamlessly. A signal processing unit stores audio data read out from a disc into a buffer memory, and performs information processing for audio playback based on the audio data in the buffer memory. Audio data of certain time durations respectively corresponding to a past and a future with respect to the audio data currently being subjected to audio playback is replenished and stored into the buffer memory. When a jog dial is manipulated, reverse playback, shuttle playback, etc. are performed quickly and seamlessly based on the audio data in the buffer memory.

Abstract: A circuit records data on an optical disk while the disk is rotated at a constant angular velocity. A velocity detector determines a velocity of a rotating disk as a detected velocity. A memory stores sets of write signal control values, and each set of write signal control values is associated with a predefined velocity. A control circuit retrieves at least two sets of write signal control values based on the detected velocity and selected predefined velocities of the sets of write signal control values. A write strategy circuit generates one or more write signals in accordance with the write signal control values of the selected set and write data. The control circuit designates a selected set of write signal control values from the at least two sets of write signal control values while generating the one or more write signals.

Abstract: OPC data record in an optical disk is performed at a plurality of record velocities to obtain a maximum record velocity Vlmax. A rotation number of the optical disk is calculated and set, the rotation number being determined in such a manner that the maximum record velocity Vlmax becomes equal to a linear velocity of the optical disk at a detected record position of the optical disk along the radial direction. The optical disk is rotated under a rotation control that a detected actual revolution number of the optical disk becomes equal to the calculated and set rotation number. It is monitored to check whether the record operation of the optical disk at the maximum record velocity Vlmax is normal. If it is detected that the record operation may become abnormal, the maximum record velocity is lowered by &Dgr;v1.

Abstract: To provide an optical disk drive having an enhanced replaying capability in case of an abnormality occurring in various kinds of synchronization of the optical disk drive or in replay of a defective sector.

Abstract: A disk reproducing device comprising: clock signal extracting means for extracting a regenerative clock signal from a reproduced signal; synchronization detecting means for detecting a synchronizing signal from the reproduced signal; extracted clock signal verification means for verifying that the regenerative clock signal is correctly extracted; signal processing means for performing variable linear velocity reproduction; target reproducing speed setting means for setting a target reproducing speed; reproducing speed verification means for verifying that a reproducing speed reaches the target reproducing speed; and signal processing start command generating means for outputting a signal processing start command referring outputs of said extracted clock signal verification means and said reproducing speed verification means.

Abstract: Multi-rate optical disc recording method and apparatus wherein data are recorded on the optical disc in accordance with a transfer rate of data, thereby preventing an unnecessary waste of a storage area in the optical disc and also enhancing a recording time of the optical disc. Said method and apparatus exploit a transfer rate detector for detecting a transfer rate of a digital signal generated at a digital signal source. This transfer rate detector allows a rotation velocity controller to rotate the optical disc at a speed corresponding to the transfer rate of the digital signal, in response to the transfer rate of the detected digital signal. Also, the transfer rate detector allows a recording portion to record the digital signal on the optical disc at the detected transfer rate.

Abstract: A disk reproducing apparatus is provided which can cope with the intermittent access due to track jump in the conventional CD reproducing system and which can reproduce data at N times the normal speed and produce the reproduced data at the normal speed. The disk reproducing apparatus includes a memory for storing the data and time information reproduced from the disk to match with each other, another external memory, a detection circuit detecting the time difference between the finally produced output data and the data which is being accessed, and a control circuit detecting the overflow/underflow of the external memory and controlling it to be written. The construction can absorb the time difference between the system operation speed and data output speed even during an intermittent access so that continuous data can be produced.

Abstract: In a memory control device for controlling the write-in/read-out operation for a memory of a recording/reproducing apparatus, a sector data storing area and an additive area are set in each sector-based data storing area in the memory. A prescribed data is stored in the additive area associated with the sector-based data stored in the sector data storing areas. The access addresses for the additive area are generated on the basis of the sector count value when the sector data write-in or read-out is carried out in the memory. The access addresses are calculated by the memory control device.

Abstract: A disk reproducing device comprising: clock signal extracting means for extracting a regenerative clock signal from a reproduced signal; synchronization detecting means for detecting a synchronizing signal from the reproduced signal; extracted clock signal verification means for verifying that the regenerative clock signal is correctly extracted; signal processing means for performing variable linear velocity reproduction; target reproducing speed setting means for setting a target reproducing speed; reproducing speed verification means for verifying that a reproducing speed reaches the target reproducing speed; and signal processing start command generating means for outputting a signal processing start command referring outputs of said extracted clock signal verification means and said reproducing speed verification means.

Abstract: A disc reproducing apparatus having a memory for temporary storage of data read from a disc. The memory is under the control of a memory controller which accesses data stored in the memory based on a generated address. The generated address is determined by a mode controller which can specify either the same address location, a previous location, or a later location depending upon the amount of data stored in the memory and errors which may occur in reading data from the disc.

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 disk reproducing apparatus is provided which can cope with the intermittent access due to track jump in the conventional CD reproducing system and which can reproduce data at N times the normal speed and produce the reproduced data at the normal speed. The disk reproducing apparatus includes a memory for storing the data and time information reproduced from the disk to match with each other, another external memory, a detection circuit detecting the time difference between the finally produced output data and the data which is being accessed, and a control circuit detecting the overflow/underflow of the external memory and controlling it to be written. The construction can absorb the time difference between the system operation speed and data output speed even during an intermittent access so that continuous data can be produced.