Abstract: In cases where forthcoming recording of information on a multi-layer optical disc is first time one, test signals are recorded on trial write areas in first and second recording layers before being reproduced. First-time optimum recording powers of the laser beam for the respective first and second recording layers are decided in response to the reproduced test signals. In cases where forthcoming recording is not first time one, the test signals are recorded on only the trial write area in the first recording layer before being reproduced. A new optimum recording power for the first recording layer is described in response to the reproduced test signals. Thereafter, a new optimum recording power for the second recording layer is calculated from (1) the new optimum recording power for the first recording layer and (2) the ratio between the first-time optimum recording powers for the first and second recording layers.

Abstract: Test signals are recorded on a prescribed area in an optical disc. The prescribed area is scanned by a laser beam while the power of the laser beam is changed among different DC erasing values. The different DC erasing values are assigned to the recorded test signals, respectively. The recorded test signals are reproduced from the prescribed area to obtain reproduced signals. Parameter values of the respective reproduced signals are detected. The detected parameter values correspond to the different DC erasing values, respectively. Among the detected parameter values, a detected parameter value is decided which matches a target. One corresponding to the decided parameter value is selected from the different DC erasing values. A prescribed coefficient and the selected DC erasing value are multiplied to calculate an optimum level of an erasing power of the laser beam.

Abstract: Test signals are recorded on a prescribed area in an optical disc. The prescribed area is scanned by a laser beam while the power of the laser beam is changed among different DC erasing values. The different DC erasing values are assigned to the recorded test signals, respectively. The recorded test signals are reproduced from the prescribed area to obtain reproduced signals. Parameter values of the respective reproduced signals are detected. The detected parameter values correspond to the different DC erasing values, respectively. Among the detected parameter values, a detected parameter value is decided which matches a target. One corresponding to the decided parameter value is selected from the different DC erasing values. A prescribed coefficient and the selected DC erasing value are multiplied to calculate an optimum level of an erasing power of the laser beam.

Abstract: In cases where forthcoming recording of information on a multi-layer optical disc is first time one, test signals are recorded on trial write areas in first and second recording layers before being reproduced. First-time optimum recording powers of the laser beam for the respective first and second recording layers are decided in response to the reproduced test signals. In cases where forthcoming recording is not first time one, the test signals are recorded on only the trial write area in the first recording layer before being reproduced. A new optimum recording power for the first recording layer is decided in response to the reproduced test signals. Thereafter, a new optimum recording power for the second recording layer is calculated from (1) the new optimum recording power for the first recording layer and (2) the ratio between the first-time optimum recording powers for the first and second recording layers.

Abstract: Multi-pulse trains of a forward laser beam are applied to an optical disc to record mark areas thereon. The multi-pulse trains correspond to the mark areas respectively. The multi-pulse trains represent information to be recorded. Detection is made as to an intensity of a reflected laser beam which results from reflection of the forward laser beam by the optical disc. The detected intensity is divided by a setting intensity to get a division result. A condition of recording of each of the mark areas is detected in response to the division result. An amplitude of each of the multi-pulse trains is controlled in response to the detected condition.

Abstract: An optical disc record carrier having at least one wobbled groove that permits information recording on both groove and land tracks is provided. Each groove has a sync wobbling modulated with a continuous signal and an address wobbling. The address wobbling includes an address portion including address information of each sector. The address portion comprising presence of a first predetermined number of wobbles and absence of a second predetermined number of wobbles. The presence and absence correspond to respective logical values of binary system. The grooves and lands are substantially the same in width throughout and wobble in phase.

Abstract: Multi-pulse trains of a forward laser beam are applied to an optical disc to record mark areas thereon. The multi-pulse trains correspond to the mark areas respectively. The multi-pulse trains represent information to be recorded. Detection is made as to an intensity of a reflected laser beam which results from reflection of the forward laser beam by the optical disc. The detected intensity is divided by a setting intensity to get a division result. A condition of recording of each of the mark areas is detected in response to the division result. An amplitude of each of the multi-pulse trains is controlled in response to the detected condition.

Abstract: An optical disc record carrier having at least one wobbled groove that permits information recording on both groove and land tracks is provided. Each groove has a sync wobbling modulated with a continuous signal and an address wobbling. The address wobbling includes an address portion including address information of each sector. The address portion comprising presence of a first predetermined number of wobbles and absence of a second predetermined number of wobbles. The presence and absence correspond to respective logical values of binary system. The grooves and lands are substantially the same in width throughout and wobble in phase.

Abstract: An optical disc record carrier having at least one wobbled groove that permits information recording on both groove and land tracks is provided. Each groove has a sync wobbling modulated with a continuous signal and an address wobbling. The address wobbling includes an address portion including address information of each sector. The address portion comprising presence of a first predetermined number of wobbles and absence of a second predetermined number of wobbles. The presence and absence correspond to respective logical values of binary system. The grooves and lands are substantially the same in width throughout and wobble in phase.

Abstract: A first laser beam and a second laser beam are selectively generated. The first or the second laser beam is irradiated on an optical storage medium having a recording layer on which main data has been recorded. The main data includes data to be reproduced and reproduction management data. The laser beam selection is made according to the reproduction management data. The first laser beam has a first laser power capable of carrying the main data without erasing when reflected from the optical storage medium. On the other hand, the second laser beam has a second laser power capable of erasing the main data from the optical storage medium while carrying the main data when reflected from the optical storage medium. The data to be reproduced and carried by the first or the second laser beam is then reproduced.

Abstract: First data is divided into second data and third data which are equal in data rate. The second data and the third data are fed to first and second recording heads respectively. The second data and the third data are simultaneously recorded on the first and second recording surfaces of the optical disc by the first and second recording heads respectively in a zoned constant linear velocity technique in which each of the first and second recording surfaces of the optical disc is divided into zones, and the zones of the first recording surface and the zones of the second recording surface are grouped into pairs each having a zone of the first recording surface and a zone of the second recording surface which are opposite to each other. In addition, the second data and the third data are simultaneously recorded on zones in a pair respectively while the first and second recording heads are moved in opposite directions respectively.