Abstract: The data recording/reproducing apparatus of the present invention efficiently performs a trickplay mode operation such as fast forward reproducing and rewind reproducing and a postrecording operation by using a data recording medium storing a variable-bitrate-compressed video data. Each AV file in the video data includes chapter data and first and second pointer data. Each GOP data in the chapter data includes one independent picture data and a plurality of dependent picture data. The first pointer data includes the location data of the independent picture data, and the second pointer data includes the location data of the first pointer data. Further, each GOP data includes an audio data interleaved with the picture data. The first pointer data includes the location data of the corresponding audio data, and the second pointer data includes the location data of the corresponding first pointer data.

Abstract: A data recording medium using a format that includes: a data zone having a plurality of bands composed of at least one track, in which user data are written; and a control zone in which band control data are written. Each of the band control data corresponds to a respective one of the plurality of bands. The band control data are independent from each other. The band control data include read control data for a READ operation and write control data for a WRITE operation, which are independent from each other.

Abstract: An information device which ensures fast data transfer between a RAM and an I/O channel, between an I/O channel and another I/O channel, or between a RAM and another RAM: comprises address decoder circuit which allows the CPU to gain simultaneous access to both the RAM and the I/O channel when the CPU accesses a data transfer area mapped for data transfer, and an inverter which assures that both the RAM and the I/O channel operate in a mutually opposite manner, either in one mode in which the RAM works in a read operation with the I/O channel in a write operation or vice versa in response to the access request of read/write from the CPU. By assuring that both the RAM and the I/O channel operate in a mutually opposite manner, in response to an access from the CPU, data transfer between the RAM and the I/O channel is completed in a single access from the CPU; thus, fast data transfer is achieved.

Abstract: An optical information recording and reproducing apparatus, and a method thereof which reproduces and records data on a sector on an optical disk. The optical information recording and reproducing apparatus is connected to a host computer. The apparatus includes a normal reproducing component for reproducing the data recorded on the information recording medium under normal reproducing conditions, and a verification, reproducing component for reproducing data recorded on the information recording medium under stricter reproducing conditions than the normal reproducing conditions. Also included is a reproduction controlling component for controlling the normal reproducing component and the verifying reproducing component to perform a reproducing operation from the same sector at the same time from the optical disk, and a recovery reporting component for reporting to the host computer when either the normal reproducing component or the verifying, reproducing component can not reproduce the data correctly.

Abstract: An inspection sector area is disposed on each data sector area of the recording area of an optical disc, and predetermined reference inspection data is recorded in the inspection sector area of a new optical disc before use. The recorded inspection data is reproduced and the number (Ej) of data errors which initially occur in the optical disc is detected by comparing the reproduced inspection data with the inspection data during recording and is memorized in the optical disc. During operation, the recorded inspection data is reproduced and compared with the reference data, and the number (Em) of data errors is issued, thereby producing the number of data errors due to particulate contamination as given by a difference between the numbers (Ej) and (Em).

Abstract: A method and apparatus for recording/reproducing information on an optical disk using the UNIX operating system. The optical disk has a plurality of partitions. An open table is provided to prevent the removal of the optical disk when the optical disk device is in use. The open table manages the use situation of the plurality of partitions. The optical disk is prohibited from being removed from the optical disk device when one partition is opened earlier than the other partitions. The removal prohibition of the optical disk is released when the final partition is closed.

Abstract: In an information recording medium, wherein data are reproduced in a sector unit, a file area for recording the file systems of a plurality of operating systems and a discrimination area for recording the position data on the file systems in the file area are provided. Then, the same data recorded in the recording medium can be managed by the operating systems of different file management systems. In a recording apparatus for reproducing data from the information recording medium, the position data are reproduced from the discrimination area and the data recorded in the information recording medium can be read by converting the position data to an actual sector address in the information recording medium. Thus, a file can by reproduced from the recording medium with either of the operating systems.

Abstract: The present invention relates to an information retrieval apparatus for retrieving large quantities of the document files stored in the information recording medium by the successive matched comparison between the character string of a target and the character string in the coded document. When the retrieving result of the document file retrieved in the past is stored within the information recording medium together with the retrieving conditions and the document file is retrieved again with the same retrieving conditions, the information retrieval apparatus of the present invention makes it unnecessary to retrieve the document file itself by the reuse of the past retrieving results if the latest retrieved date and time are newer than the recording date and time of the document file so as to shorten the retrieving time.

Abstract: A multi-layered optical disk comprising a plurality of recording layers accumulated in the thickness direction wherein a light beam is focused on one of tracks of one of the layers thereby to record and reproduce data, the optical disk being characterized in that recording layers each have an identification section storing an address of the recording layer which the identification section belongs to.

Abstract: An information writing and reading apparatus for writing and reading data on a recording disk has a plurality of rewritable sectors for storing normal data and a plurality of DMA sectors for storing defect management data repeatedly in a plurality of DMAs (Defect Management Areas). The information writing and reading apparatus includes DMA register for storing condition data representing the condition of the DMA sectors, erasing device for erasing data in the recording disk by a sector, and a controller for controlling such that after one DMA sector is erased by the erasing device, a condition of the DMA sector is examined whether it is a defectless sector or a defect sector, and a flag representing the examined result is stored in the DMA register.

Abstract: In recording data on a disk-shaped information recording medium having formed thereon a plurality of concentric or spiral tracks each being divided into a plurality of sectors each having an ID field and a data field, a data mark is selected from a plurality of distinct data marks according to an address of a target sector such that the selected data mark is different from a data mark recorded in an adjacent sector which is contained in an adjacent track. The selected data mark is recorded at the start position of the data field of the target sector. In reproducing the recorded data, a data mark is selected from the plurality of distinct data marks according to an address of a target sector, and is compared with a data mark reproduced from the target sector to detect whether the reproduced data mark coincides with the selected data mark. Sector data in the target sector is reproduced only when the reproduced data mark coincides with the selected data mark.

Abstract: An information recording and reproducing apparatus has a plurality of optical disk drives including a data optical disk drive for storing data, a work or backup optical disk drive for temporarily storing the data and, preferably, a disk cache memory. The optical disk drives are coupled to a host device such as a central processing unit (CPU) through an optical disk control unit for controlling recording and reproduction of the data. The optical disk control unit writes commands and data transmitted from the host device into the work optical disk drive and the disk cache memory and, if required, writes the data of the disk cache memory into the data optical disk drive.

Abstract: A multi-layered optical disk comprising a plurality of recording layers accumulated in the thickness direction wherein a light beam is focused on one of tracks of one of the layers thereby to record and reproduce data, the optical disk being characterized in that recording layers each have an identification section storing an address of the recording layer which the identification section belongs to.

Abstract: An information recording and reproducing apparatus includes a rewritable optical disc having a plurality of sectors on which data can be rewritten. The rewritable optical disc is divided into an additionally recordable region in which the data are additionally recorded and a rewritable disc control region in which an address of a latest recorded sector in the additionally recordable region is recorded. The optical disc is used as an additionally recordable optical disc in which recording is permitted only one time and reproduction can be performed plural times. The information recording and reproducing apparatus further includes a control circuit for recording data on unrecorded sectors in the additionally recordable region and for reading the data from recorded sectors. This control circuit can rewrite and reproduce data in the disc control region.

Abstract: A disk shaped information recording medium has a virtual ROM area where data sectors, and parity sectors are recorded, and a disk definition area where management data of a virtual ROM area is recorded in a rewritable user area information recording and reproducing apparatus fabricates the information recording medium. Also, the information recording and reproducing apparatus prohibits a data recording operation with respect to the virtual ROM area and recovers a data of the defective sector detected in the virtual ROM area using a parity sector.

Abstract: A double-sided optical disc player which comprises first and second optical heads for radiating laser beams to tracks on respective sides of a double-sided optical disc; first and second ID read-out units for reading respective sector addresses out from associated sector identifiers; an ID offset detecting unit for calculating, in response to outputs from the ID read-out unit, the ID offset value descriptive of an angular displacement in sector position between the opposite sides of the optical disc traced by the associated optical heads; an ID offset retaining unit for retaining the ID offset value; a first sector recording and/or production control unit for detecting a target sector when an sector address output from the first ID read-out unit coincide with the target sector and for activating a recording or reproduction of information; an adder for adding the ID offset value to an output from the second ID read-out unit; a second sector recording and/or reproduction control unit for detecting a target obje

Abstract: An optical disk recording and/or reproducing apparatus realizes a high ability to transmit data by operating a plurality of optical disk drives in parallel. By actuating the data recording or reproducing operation in parallel after these optical disk drives all have completed seeking the target track, deviation in synchronism between these drives can be suppressed below a one track maximum, resulting in the parallel operation of a plurality of optical disk drives using a a small capacity memory. In addition, by transmitting data via a high speed FIFO memory connected to each drive interface and a host interface to a RAM, speedy data transmission using the parallel operation of the plurality of drives is made possible.

Abstract: In data recording medium used with the apparatus of the present invention, there are allocated a sequential access zone consisting of a data area for recording real time data such as sounds or video images, a C list area for recording a C defect list managing defective sectors detected in the formatting process, and a G list area for recording a G defect list managing defective sectors detected in the recording process of data, and a random access zone consisting of a data area for recording random access data such as code data, a spare area for replacing defective sectors detected in the recording process, and an R list area for recording an R defect list managing the relation between defective sectors and corresponding spare sectors. In the recording process of data in the sequential access zone, data is recorded while defective sectors registered in the C defect list and G defect list are skipped, thereby achieving recording of both the random access data and the real time data.

Abstract: A data reproducing system is provided wherein data stored in an optical disk can be read and, in accordance with a coded error detection and correction code, can have an error pointer defined in synchronization with a modulated data of one symbol. This information can be transmitted, through a time division multiplexing circuit, at a faster clock speed than a demodulating clock with which the timing of a data demodulating will be controlled.

Abstract: This invention provides an erasable optical disk, on which information is recorded and reproduced repeatedly through the irradiation of laser beams, and an optical information recording/reproduction apparatus which records and reproduces information on the erasable optical disk. In erasing and then recording information on the erasable optical disk by using an erasing laser beam and a recording/reproduction laser beam, respectively, the tracking of both laser beams on the same track is detected so as to prevent erroneous erasing. The apparatus uses the optical disk having a mark signal disposed between a sector identifier and a data field, which mark signal is capable of determining the presence of the erasing laser beam on an adjacent track on the erasable optical disk, and the apparatus reproduces and detects the mark signal by using the erasing laser beam.