Patent ID: 8023380
Filing Date: 2011-09-20
Classification: G11B

Abstract:
1. A data storage medium comprising a recording area on which a plurality of recording marks and spaces having lengths defined by a predetermined modulation method are formed by emitting a pulsed light beam to the data storage medium, wherein at least two of the plurality of recording marks comprise: a first pulse which is disposed at a front and forms a leading edge of the recording mark, a last pulse which is disposed at a backend and forms a trailing edge of the recording mark, and a multi-pulse train which is disposed between the first pulse and the last pulse and forms a center of the recording mark, the multi-pulse train has a pulse period longer than T, T representing a reference period of the recording modulation code, the number of pulses in each of the recording marks is increased by one as the recording mark is increased in length by 2 T, the plurality of recording marks have different lengths differing by T or multiples thereof from one another, the shortest recording mark and the second shortest recording mark are each constituted by a single pulse, and the third shortest recording mark and the fourth shortest recording mark are each constituted by two pulses, a last pulse rising timing an n the multi-pulse trains of the plurality of recording marks have an equal pulse width with each other, and the multi-pulse trains of the plurality of recording marks have an equal pulse period with each other.