Patent ID: 6175541
Filing Date: 2001-01-16
Classification: G11B

Abstract:
A data recording medium having a plurality of tracks for recording information represented as marks and spaces between the marks in a data recording area of the data recording medium, the marks being formed by an optical beam modulated by one or a plurality of drive pulses comprising a first pulse, a last pulse and one or more multiple pulses between the first and last pulses, where a number of the drive pulses is determined according to a length of a mark part in the input signal to be recorded on the track, said data recording medium comprising:a control information recording area storing:last pulse movements (TL) for modifying the last pulse of the drive pulses, said last pulse movements (TL) being separated at least into nine groups determined by a combination of three groups of different lengths of a mark and three groups of different lengths of a space immediately following the mark, the three groups of different mark lengths being a group with only the first pulse, a group with the first pulse and the last pulse, and a group with the first pulse, the multiple pulse and the last pulse, wherein said last pulse movements (TL) indicate either a pulse shift amount for shifting the first pulse without changing a pulse width, or a pulse width amount for changing the pulse width of the last pulse; anda code indicating a method for using said last pulse movements (TL) either as the pulse shift amount or as the pulse width amount.