Patent ID: 7443775

Claim:
A method for recording data in an optical recording medium wherein data are recorded in a write-once type optical recording medium comprising a substrate and at least one recording layer formed on the substrate, comprising: projecting a laser beam through an objective lens onto the optical recording medium to record the data, the laser beam having a wavelength λ equal to or shorter than 450 nm, the objective lens having a numerical aperture (NA) operable to satisfy λ/NA≦640 nm, and a power of the laser beam is modulated by a pulse train pattern including at least a pulse whose level is set to a level corresponding to a recording power and a pulse whose level is set to a level corresponding to a first bottom power onto the at least one recording layer and forming at least two recording marks in the at least one recording layer; and modulating the power of the laser beam by the pulse train pattern further including a pulse whose level is set to a level corresponding to a second bottom power lower than the first bottom power on at least one of front and rear sides of the pulse whose level is set to the level corresponding to the recording power, wherein the pulse whose level is set to the recording level has (n−a) divided pulses when a recording mark having a length nT is formed, where n is an integer equal to or large that 2, where a is set to 2 in an 8/16 Modulation Code and a is set to 1 in a 1.7RLL modulation, and where T is a clock cycle, the at least two recording marks formed by setting a ratio of a shortest blank region interval to a linear recording velocity to be equal to or smaller than 20 nsec and the pulse whose level is set to a level corresponding to the recording level is constituted by divided pulses of a number corresponding to a length of the recording mark, and setting the power of the laser beam to the first bottom power between neighboring divided pulses.