Abstract: An apparatus for reading subdivided information from an optical disk, which comprises a track groove and on which information is recorded along the track groove is disclosed. The apparatus includes an optical head, which irradiates the optical disk with light and generates an electric signal responsive to part of the light that has been reflected from the optical disk, read signal processing means for generating a wobble signal which has an amplitude changing with the wobble pattern from the electric signal, rise value acquiring means for sampling and holding an absolute gradient value of the wobble signal when the signal rises, fall value acquiring means for sampling and holding an absolute gradient value of the wobble signal when the signal falls, and subdivided information detecting means for determining the subdivided information by majority by comparing the values held by the rise and fall value acquiring means with each other.

Abstract: There is provided a driving apparatus of an electric motor for a reduction roll that can improve maximization of rolling performance and a speed decrease amount by making maximal use of torque that various electric motors can generate during material entry.

Abstract: A recording medium comprising a recording area, the recording area includes a first area and a second area, the first area includes a frame area, the frame area includes an area in which a second synchronization code sequence and at least a portion of data are to be recorded, and the second area includes an area in which a third synchronization code sequence and a fourth synchronization code sequence are to be recorded.

Abstract: An optical disk includes a groove and a land. Data is recorded on either the land or the groove. A pitch of the groove and a pitch of the land are 0.32 ?m or more. The optical disk has a data efficiency of 80% or more by adopting a format in which other types of user data are added to every plural user data sets. The data efficiency is defined by a ratio of a user data capacity that can be used by a user to a total data capacity of the optical disk.

Abstract: A driving device driving motors of rolling rolls that corrects asymmetry between top and bottom roll driving systems of a twin-drive rolling mill in which top and bottom rolling rolls are driven by upper and lower motors, respectively, so that torques propagate to the top and bottom rolling rolls simultaneously. To this end, an upper/lower axis system imbalance correction section that corrects inequalities of torques propagating to the top and bottom rolling rolls is provided in either one or both of an upper motor control section that controls the upper motor and a lower motor control section that controls the lower motor in a driving device of motors for rolling rolls used in a rolling mill. The top and bottom rolling rolls are driven by the upper motor and the lower motor, respectively, and one of the upper motor and the lower motor is located on a rolled material. Thus, torques propagate to the top and bottom rolling rolls simultaneously.

Abstract: A recording medium comprising a recording area, the recording area includes a first area and a second area, the first area includes a frame area, the frame area includes an area in which a second synchronization code sequence and at least a portion of data are to be recorded, and the second area includes an area in which a third synchronization code sequence and a fourth synchronization code sequence are to be recorded.

Abstract: An optical recording medium that allows information to be recorded and played back properly, even when a type of recording medium in which information is recorded to grooves is used along with a type of recording medium in which information is recorded to lands, as well as a method for recording and playback with this medium. Recording track information is recorded in advance, indicating whether information is to be recorded in the grooves or the lands, whichever of the grooves and lands is best suited to the recording of information is selected on the basis of the recording track information that is read out, and the recording or playback of information is performed.

Abstract: A multi-layered information recording medium including a plurality of recording layers, the multi-layered information recording medium comprising: a user data area for recording user data; and a plurality of spare areas including at least one replacement region, wherein when the user data area includes at least one defect region, the at least one replacement region may be used in place of the at least one defect region, wherein a first spare area of the plurality of spare areas is positioned so as to be contiguous to a first user data area of a first recording layer, a second spare area of the plurality of spare areas is positioned so as to be contiguous to a second user data area of a second recording layer, and the first spare area and the second spare area are positioned approximately at the same radial position on the multi-layered information recording medium.

Abstract: A multi-layered information recording medium including a plurality of recording layers, the multi-layered information recording medium comprising: a user data area for recording user data; and a plurality of spare areas including at least one replacement region, wherein when the user data area includes at least one defect region, the at least one replacement region may be used in place of the at least one defect region, wherein a first spare area of the plurality of spare areas is positioned so as to be contiguous to a first user data area of a first recording layer, a second spare area of the plurality of spare areas is positioned so as to be contiguous to a second user data area of a second recording layer, and the first spare area and the second spare area are positioned approximately at the same radial position on the multi-layered information recording medium.

Abstract: An optical disk includes a land and a groove. The optical disk has a data efficiency of 80% or more. Data is recorded on both the land and the groove. A distance between the center of the land and the center of the groove adjacent to the land is 0.28 ?m or more. Thus, an optical disk having a storage capacity of 25 GB or more can be provided.

Abstract: An information recording medium is provided, which comprises a plurality of recording layers and a first disc information area for storing parameters relating to access to the plurality of recording layers and formats relating to the plurality of recording layers. The first disc information area is provided in a first recording layer which is one of the plurality of recording layers.

Abstract: A multi-layered information recording medium including a plurality of recording layers, the multi-layered information recording medium comprising: a user data area for recording user data; and a plurality of spare areas including at least one replacement region, wherein when the user data area includes at least one defect region, the at least one replacement region may be used in place of the at least one defect region, wherein a first spare area of the plurality of spare areas is positioned so as to be contiguous to a first user data area of a first recording layer, a second spare area of the plurality of spare areas is positioned so as to be contiguous to a second user data area of a second recording layer, and the first spare area and the second spare area are positioned approximately at the same radial position on the multi-layered information recording medium.

Abstract: An optical disk and a method for identifying the optical disk making it possible to identify a recording system of the optical disk easily in a short time by a recording and reproduction apparatus when a groove-recording system and a land-recording system are both employed in one kind of optical disk, such as, for example, a BD-R. Specifically, a polarity upon reproducing wobble information is made to be the same in both an optical disk of groove-recording system and the optical disk of a land-recording system. The recording system of the optical disk that shows the same wobble polarity irrespective of the recording system can be easily detected by finding a tracking polarity that can recognize the wobble information by changing the tracking polarity, whereby the start-up time of the recording and reproduction apparatus can be shortened.

Abstract: An optical disc drive having an optical pickup head emitting a light beam to an optical storage medium, detecting the light beam reflected from the optical storage medium, and outputting a signal based on the received reflected light, having a jitter measuring unit measuring jitter in signals output from the optical pickup head and having an evaluation unit determining from the measured jitter if the optical storage medium is good or defective. The jitter measuring unit measures jitter in a train of 3T or longer marks or spaces from an optical storage medium to which digital information is recorded as a train of marks or spaces of length kT based on a period T and an integer k of two or more.

Abstract: There is provided a driving apparatus of an electric motor for a reduction roll that can improve maximization of rolling performance and a speed decrease amount by making maximal use of torque that various electric motors can generate during material entry.

Abstract: A method of recording data optically to an optical disk having a plurality of sectors, in which each sector has a region to be recorded with data, the data is recorded in units of blocks, and the block includes a predetermined number of sectors and is a data unit including error correction codes. In recording data related to a content by dividing and recording the data in a plurality of sectors continuously, dummy data to be used for extracting a clock in phase lock loop (PLL) for data reproduction is recorded on a region adjacent before a sector from which data recording is started. The data related to the contents is recorded on sectors following the region recorded with the dummy data.

Abstract: An optical disk medium includes a track groove thereon. On the optical disk medium, information is recorded along the track groove on a block unit basis. The block unit has a predetermined length. The block unit having the predetermined length includes a number of sub-blocks that are arranged along the groove. A sub-block mark is provided within each of the sub-blocks and used to identify the sub-block.

Abstract: An optical disc medium comprises a track groove, along which main information is recorded. The track groove is divided into a plurality of blocks. The plurality of blocks each include a plurality of frames. The plurality of frames each include one shape of wobbles indicating sub information, among a plurality of prescribed shapes of wobbles. The plurality of blocks each have address information. The address information is represented by a string of at least one piece of sub information represented by the shape of wobbles of at least one of the plurality of frames.

Abstract: An information recording medium is provided, which comprises a plurality of recording layers and a first disc information area for storing parameters relating to access to the plurality of recording layers and formats relating to the plurality of recording layer. The first disc information area is provided in a first recording layer which is one of the plurality of recording layers.

Abstract: When recording or reading an optical disc having plural data recording layers, which data recording layer the light spot is focused on is detected to improve playback signal quality and signals written to the layer on which the light spot is focused are read more reliably. A convergent lens converges the laser beam on the optical disc, and a focus controller controls the focal point of the laser beam on the data layer. A tracking controller positions and tracks the focal point of the laser beam converged by the convergent lens on a track of the optical disc. A photodetector detects the reflected laser beam from the disc. A convergence detector then detects the convergence state of the laser beam emitted to the plural data recording layers. Based on output from the convergence detector, the laser driver is controlled to separately set beam power appropriately for each of the plural data layers of the disc during playback.