Patent ID: 8174948
Filing Date: 2012-05-08
Classification: G11B

Abstract:
1. An optical disc comprising first and second recording layers configured to store or reproduce information by light with a predetermined wavelength, the information being configured to be recorded on the first or second recording layer using a mark and a space, and the first or second recording layer having a low-to-high characteristic, wherein a channel clock period is represented by T, the channel clock period T being provided for recording the mark on the first or second recording layer where the mark regarding 3T can be recorded, a plurality of pulses including a last pulse arranged at an end of the pulses are used for recording the mark regarding 3T, the mark regarding 3T being configured to be recorded with a condition that a width of the last pulse is 0T at minimum and 1.10T at maximum, in which a first subsequent level lower than a peak power level of the last pulse is arranged next to the last pulse, and a second subsequent level lower than the peak power level but higher than the first subsequent level is arranged next to the first subsequent level, and the optical disc further comprises an area configured to store information relating to a duration of the last pulse used for the first recording layer.