Abstract: An optical disk physical has a recording region divided into zones, each zone including physical tracks adjacent to each other. An integer number of sectors, are provided in each physical track. The angular recording density is higher in the more outward zones such that the linear recording density is substantially constant throughout the recording region, and logical tracks are formed of a predetermined number of sectors, independent of the physical tracks. The conversion between the logical track and sector addresses read from the disk and the linear logical addresses supplied from a host device is easy. The addresses written in headers of the sectors in the logical track in which data are actually recorded, including substitute sectors used in place of defect sectors, are preferably consecutive to further facilitate the conversion between the logical track and sector addresses read from the disk and the linear logical addresses supplied from the host device.

Abstract: An optical disk physical has a recording region divided into zones, each zone including physical tracks adjacent to each other. An integer number of sectors are provided in each physical track. The angular recording density is higher in the more outward zones such that the linear recording density is substantially constant throughout the recording region, and logical tracks are formed of a predetermined number of sectors, independent of the physical tracks. The conversion between the logical track and sector addresses read from the disk and the linear logical addresses supplied from a host device is easy. The addresses written in headers of the sectors in the logical track in which data are actually recorded, including substitute sectors used in place of defect sectors, are preferably consecutive to further facilitate the conversion between the logical track and sector addresses read from the disk and the linear logical addresses supplied from the host device.

Abstract: An optical disk has two sides for recording data and at least one recording area for each side. Each recording area is associated with an attribute which designates whether the corresponding recording area is an area which permits rewriting or an area which does not permit rewriting. Data representing the attribute for the at least one recording area of each side is recorded in a structure management table provided in a predetermined part of the disk of each side. The two sides of the disk have different attributes.

Abstract: When optical disk defects are managed by using non-defective areas in place of defective areas, different criteria are used for detecting the defects, depending on the type of data recorded on the disk. For example, to avoid interruptions of real-time recording, less strict criteria are used when audio or video data is recorded than when computer data is recorded. The criteria themselves may also be recorded on the disk.

Abstract: An optical disk physical has a recording region divided into zones, each zone including physical tracks adjacent to each other. An integer number of sectors, are provided in each physical track. The angular recording density is higher in the more outward zones such that the linear recording density is substantially constant throughout the recording region, and logical tracks are formed of a predetermined number of sectors, independent of the physical tracks. The conversion between the logical track and sector addresses read from the disk and the linear logical addresses supplied from a host device is easy. The addresses written in headers of the sectors in the logical track in which data are actually recorded, including substitute sectors used in place of defect sectors, are preferably consecutive to further facilitate the conversion between the logical track and sector addresses read from the disk and the linear logical addresses supplied from the host device.

Abstract: When optical disk defects are arranged by using non-defective areas in place of defective areas, different criteria are used for detecting the defects, depending on the type of data recorded on the disk. For example, to avoid interruptions of real-time recording, less strict criteria are used when audio or video data is recorded than when computer data is recorded. The criteria themselves may also be recorded on the disk.

Abstract: When optical disk defects are managed by using non-defective areas in place of defective areas, different criteria are used for detecting the defects, depending on the type of data recorded on the disk. For example, to avoid interruptions of real-time recording, less strict criteria are used when audio or video data is recorded than when computer data is recorded. The criteria themselves may also be recorded on the disk.

Abstract: When optical disk defects are managed by using non-defective areas in place of defective areas, different criteria are used for detecting the defects, depending on the type of data recorded on the disk. For example, to avoid interruptions of real-time recording, less strict criteria are used when audio or video data is recorded than when computer data is recorded. The criteria themselves may also be recorded on the disk.

Abstract: In order to enable recording and reproduction from optical disks with defect management formatted with different group configurations without changing the firmware of the conventional apparatus and to allow the size of the spare area to be specified at initialization, the position information indicating the position of the defect management area is recorded in the control data area provided in the read-only area of the optical disk, and the information indicating the first address or size of the spare area is included in the defect management area.

Abstract: An optical disk physical has a recording region divided into zones, each zone including physical tracks adjacent to each other. An integer number of sectors are provided in each physical track. The angular recording density is higher in the more outward zones such that the linear recording density is substantially constant throughout the recording region, and logical tracks are formed of a predetermined number of sectors, independent of the physical tracks. The conversion between the logical track and sector addresses read from the disk and the linear logical addresses supplied from a host device is easy. The addresses written in headers of the sectors in the logical track in which data are actually recorded, including substitute sectors used in place of defect sectors, are preferably consecutive to further facilitate the conversion between the logical track and sector addresses read from the disk and the linear logical addresses supplied from the host device.

Abstract: In order to enable recording and reproduction from optical disks with defect management formatted with different group configurations without changing the firmware of the conventional apparatus and to allow the size of the spare area to be specified at initialization, the position information indicating the position of the defect management area is recorded in the control data area provided in the read-only area of the optical disk, and the information indicating the first address or size of the spare area is included in the defect management area.

Abstract: When optical disk defects are arranged by using non-defective areas in place of defective areas, different criteria are used for detecting the defects, depending on the type of data recorded on the disk. For example, to avoid interruptions of real-time recording, less strict criteria are used when audio or video data is recorded than when computer data is recorded. The criteria themselves may also be recorded on the disk.

Abstract: An optical disk has a recording region divided into zones, each zone including physical tracks which are divided into a number of sectors. The optical disk further includes a structure management table which stores an attribute for each zone indicating whether the corresponding zone is a recording area which permits rewriting of a recording area that does not permit rewriting.

Abstract: An optical disk physical has a recording region divided into zones, each zone including physical tracks adjacent to each other. An integer number of sectors are provided in each physical track. The angular recording density is higher in the more outward zones such that the linear recording density is substantially constant throughout the recording region, and logical tracks are formed of a predetermined number of sectors, independent of the physical tracks. The conversion between the logical track and sector addresses read from the disk and the linear logical addresses supplied from a host device is easy. The addresses written in headers of the sectors in the logical track in which data are actually recorded, including substitute sectors used in place of defect sectors, are preferably consecutive to further facilitate the conversion between the logical track and sector addresses read from the disk and the linear logical addresses supplied from the host device.

Abstract: A composite web including an elastically stretchable web and an inelastically stretchable web bonded together is stretched on a course defined between at least two nip roll pairs to obtain an elastically stretchable composite sheet. The composite web is brought into contact with a peripheral surface of at least one roll of each nip roll pair over an area of the peripheral surface defined by a quadrant of this roll's circular cross section.

Abstract: In a video disk recording/playback device for converting a digital video signal or the like into high-efficiency coded data and recording the coded data on a video disk, or for restoring high-efficiency coded data recorded on the video disk and reproducing an output image, wherein said digital video signal is composed of a succession of video signals of a plurality of frames and including an I picture encoded within a frame, a P picture interframe coded by forward motion compensation with reference to said I picture and/or another P picture, and a B picture interframe coded by motion compensation in both directions with reference to said I and/or P pictures temporally preceding and succeeding the B picture, there are further provided a means for recording in an image information table set up on said video disk all of the start addresses of coded data representing selected images such as images to be retrieved and the start addresses of data containing information required for reproducing the coded data.

Abstract: An elastically stretchable composite sheet includes an elastic layer and an inelastic layer formed with stretchable fibers having a relatively small diameter and bonded to at least one surface of the elastic layer. In the inelastic layer bonded to the elastic layer is formed with thermoplastic synthetic fiber, at least 80% by weight of stretchable fibers includes thermoplastic synthetic fiber containing lubricant of 0.1˜5.0% by weight.

Abstract: When optical disk defects are managed by using nondefective areas in place of defective areas, different criteria are used for detecting the defects, depending on the type of data recorded on the disk. For example, to avoid interruptions of real-time recording, less strict criteria are used when audio or video data is recorded than when computer data is recorded. The criteria themselves may also be recorded on the disk.

Abstract: When optical disk defects are managed by using non-defective areas in place of defective areas, different criteria are used for detecting the defects, depending on the type of data recorded on the disk. For example, to avoid interruptions of real-time recording, less strict criteria are used when audio or video data is recorded than when computer data is recorded. The criteria themselves may also be recorded on the disk.

Abstract: When optical disk defects are managed by using non-defective areas in place of defective areas, different criteria are used for detecting the defects, depending on the type of data recorded on the disk. For example, to avoid interruptions of real-time recording, less strict criteria are used when audio or video data is recorded than when computer data is recorded. The criteria themselves may also be recorded on the disk.