Patent ID: 8149673

Claim:
An optical recording method for recording information by irradiating an optical disc medium with a modulated write pulse train of laser light variable over a plurality of power levels such that a plurality of marks are formed on the optical disc medium, edge positions of each of the marks and a space between adjacent two of the marks being utilized for recording of the information, the method comprising the steps of: encoding record data to generate encoded data which is a combination of marks and spaces; classifying the encoded data according to a combination of a mark length of a mark, a space length of a first space that immediately precedes the mark, and a space length of a second space that immediately succeeds the mark; generating a write pulse train for forming the mark, in which at least one of a leading end edge position, a trailing end edge position, and a pulse width of the write pulse train is changed according to a result of the classification; and irradiating the optical disc medium with the generated write pulse train to form the plurality of marks on the optical disc medium, wherein the space length of the first space is classified in M space length classes (M is an integer equal to or greater than 1) and the space length of the second space is classified in N space length classes (N is an integer equal to or greater than 1), and wherein: in the case of one of the leading end edge position and the pulse width is changed, the step of generating the write pulse train changes one of the leading end edge position and the pulse width according to the result of the classification so that M is greater than N; and in the case of the trailing end edge position is changed, the step of generating the write pulse train changes the trailing end edge position according to the result of the classification so that N is greater than M.