Patent ID: 7512050

Claim:
An information recording method of recording information by forming recording marks by emitting light, from a light source on a record medium, modulated according to record information and rules by use of n (n: integer more than one) type data length sets which are classified by a data length of record information such that the rules of recording waveforms thereof are different, comprising: a first trial write step of writing as a trial a predetermined first test pattern in a trial write area of the record medium while changing a recording power for emitting in a stepwise manner, so as to obtain an optimum recording power from a reproduced signal of recorded trial write data; and a second trial write step of performing trial write in the trial write area of the record medium by use of the optimum recording power by using a second test pattern corresponding to each of the data length sets while changing pulse width or pulse edge position of recording waveform for each of the data length sets in a stepwise manner, and obtaining an optimum pulse width or optimum pulse edge position of the recording waveform corresponding to each of the data length sets from a reproduced signal of each recorded second test pattern, wherein information is recorded based on the optimum recording power obtained in said first trial write step and the optimum pulse width or optimum pulse edge position obtained in the second trial write step; and wherein said first trial write step includes: a first test pattern generating step of generating the first test pattern for performing trial write in the trial write area of the record medium; and an optimum recording power obtaining step of obtaining the optimum recording power from the reproduced signal of the recorded trial write data, and wherein said second trial write step includes: a second test pattern generating step of generating the second test pattern corresponding to each of the data length sets for performing of trial write; a trial write processing step of performing trial write in the trial write area of the record medium by using the optimum recording power and the second test pattern while maintaining fixed pulse width and fixed pulse edge position of recording waveform for one or more particular data length sets and while changing pulse width or pulse edge position of recording waveform for other data length sets in a stepwise manner; and an optimum recording waveform obtaining step of obtaining the optimum pulse width or optimum pulse edge position of recording waveform corresponding to the data length sets from the reproduced signal of the second test pattern corresponding to said other data length sets by using a reference asymmetry value derived from a reproduced signal of recorded trial write data corresponding to the second test pattern corresponding to said one or more particular data sets.