Abstract: A method for reproducing information from an optical medium including a substrate with grooves and lands alternately formed on the substrate in a radial direction. The grooves and the lands both serve as tracks which are divided into units in the circumferential direction. Each unit has a prepit area in a non-groove portion of the substrate with a first prepit being represented as VFO information in the prepit area and a second prepit being represented as address information in the prepit area. The first prepit and second prepit are located on both sides of a center line of one track and are arranged with respect to one another. The method includes irradiating an optical spot on the optical medium, detecting address information, controlling the irradiation position of the optical spot on the basis of the address information and reproducing information.

Abstract: The present invention provides a method of determining a distance for moving an optical pick-up from a current track to a target track based on a distance from an exact single track width formed on an optical disc. According to the present invention, a method of determining a single track width of an optical disc by an optical pick-up includes the steps of a) calculating a number of tracks crossed by the pick-up using a detection of an initial track position information of an initial track when performing an initial loading of the disc, and track position information of a predetermined track located away the predetermined distance form the initial track; and b) calculating a single track width depending on the predetermined distance and the calculated number of tracks to be crossed by the pick-up. In the present invention, the access time of various optical discs is identical regardless of the size of a single track width of an optical disc.

Abstract: An optical pickup applies five different light beams at the same time to every second five tracks on a signal plane of a CD-ROM. A record data read system reads record data independently for each light beam system in accordance with outputs of respective light beams reflected from the signal plane, and stores the read record data in the record order. Under the control of a system controller, the optical pickup and record data read system read the record data of the CD-ROM by alternately performing an operation of continuously reading the record data with the five light beam systems during approximately two rotations of the CD-ROM and a track jump operation by seven tracks in a forward direction after the continuous reading operation with a combination of the five light beam systems shows no omission of the record data of the CD-ROM.

Abstract: A user can designate a track for program reservation of a Carousel player capable of loading both a CD and DVD-Audio, smoothly irrespective of the type of a disk. It is first checked whether a track corresponding to the disk number entered by a user is a track of CD or DVD-Audio. If the track is a track of a CD, after the disk number input, the user is immediately requested to enter a track number, whereas if the track is a track of a DVD-Audio, the user is requested to enter a group number and then the user is requested to enter a track number.

Abstract: In a CD-ROM reader system wherein five adjacent tracks of a CD-ROM are separately illuminated by five light beams of an optical pickup, a recorded data readout system simultaneously reads the recorded data of the separate tracks by detecting the received light outputs of the returned beams, and outputs the data in the sequence in which it was recorded. For example, if one light beam becomes unreadable by the recorded data readout system, the system will read the recorded data using the remaining four light beams. This readout is performed in recurring operations in which data is read for approximately one revolution of the CD-ROM; then, after there are no longer any gaps in the combined data, the pickup is track-jumped forward by approximately two tracks. At this point the recorded data is again read for one revolution, and the process repeats.

Abstract: When controlling a search for a target track on an optical disk having tracks on which data are recorded, the track-search control apparatus determines whether or not the optical disk is a DVD-RW disk. Then the apparatus calculates the number of tracks between the position of the currently detected track and the position of the target track, and calculates the number of correction tracks with which to correct the calculated number of tracks when the optical disk is determined to be a DVD-RW disk. Further, the apparatus executes the search for the target track based on the calculated corrected number of tracks.

Abstract: Physical addresses of the recording areas provided on an optical disc are represented in the first format that is time-axis data and the second format that is binary data. The physical address value gradually increases from the inner most part toward the outermost part of this disc, while the first format and the second format remains in one-to-one correspondence over the entire recording areas. The distance the optical head must move to reach the target recording area can therefore be calculated easily, no matter where on the disc the optical is located at present. This enables the optical head to make a fast access to the target recording area.

Abstract: Pieces of address information are recorded on an optical disc such that they are successively continuous addresses within each zone but discontinuous at a beginning of a zone next to the previous zone, and an address after repeating the addresses of the previous zone for two rounds becomes the forefront address of the zone next to the previous zone. Access to the land tracks is performed by returning to the first address position in a zone after the addresses of the groove tracks become the last address of the zone, and the access is performed by recognizing an address continued from the last address of the groove tracks suppositionally on the pieces of address information recorded on the groove tracks, and then the access is successively performed to move to the next zone after the addresses of the land tracks become the last address of the zone.

Abstract: An information recording medium in which bottoms of a guide groove and a pit array formed on a disc substrate are allocated on a same flat plane and shaped in flat. Further, in a transition area from a pit array to a guide groove or from a guide groove to a pit array, the information recording medium is provided with an intermediate area composed of a pit array of which height changes from a height between a bottom and a side of a groove to another height between the bottom and a side of the pit array.

Abstract: An optical record carrier comprises substantially parallel tracks being divided into recording units having an address area (23,24), adjacent address areas of adjacent tracks (43,44) comprising shared address marks (48). Shared address marks (47,48) are positioned in between adjacent tracks and arranged in sharing portions (40,41) of the address area, each sharing portion sharing address marks only to one side. The address area also comprises a free portion (39) which is free from shared address marks, which free portion is aligned with a sharing portion (42) of an adjacent address area. This is advantageous for reducing crosstalk in the address read signal. The sequence of the free and sharing portions within an address area differs so as to be matching in adjacent address areas.