Patent ID: 7313070

Claim:
A recording method for a rewritable optical recording medium, which comprises: recording information on a rewritable optical recording medium by a plurality of record mark lengths and space lengths between record marks based on EFM or EFM+ modulations or (1,7) runlength limited (RLL) non-return-to-zero inverted (NRZI) modulation system, wherein: between record marks, a laser beam having an erasing power Pe capable of crystallizing an amorphous phase is irradiated to form spaces between record marks, and when the time length of one record mark is represented by nT (where T is the reference clock period), for a record mark of n=2m (where m is an integer of at least 1), of which the time length (n−j)T (where j is a real number from −2.0 to 2.0) is divided into m sections of α i T and β i T comprising α 1 T, β 1 T, α 2 T, β 2 T, . . . , α m T and β m T (provided that Σ i (α i +β i )=n−j), and for a record mark of n=2m+1 (where m is an integer of at least 1), of which the time length (n−k)T (where k is a real number from −2.0 to 2.0) is divided into m sections of α i ′T and β i ′T comprising α 1 ′T, β 1 ′T, α 2 ′T, β 2 ′T, . . . , α m ′T and β m ′T (provided that Σ i (α i ′+β i ′)=n−k), a laser beam having a constant writing power Pw sufficient to melt the recording layer is applied within a time of α i T and α i ′T (where i is an integer from 1 to m), and a laser beam having a bias power Pb is applied within a time of β i T and β i ′T (where i is an integer from 1 to m); and further, when m≧3, for a record mark of n=2m, when the start time for nT mark is represented by T 0 , (i) after a delay time T d1 T from T 0 , α 1 T is generated, then, (ii) within i=2 to m, β i−1 T and α i T are alternately generated in this order, while β i−1 +α i is between 1.8 and 2.2 (provided that at i=2 and/or i=m, β i−1 +α i may be deviated from about 2 within a range of ±0.5, and when m≧4, β i−1 and α i take constant values βc and αc, respectively, within i=3 to m−1), and then, (iii) β m T is generated, and for a record mark of n=2m+1, when the start time for nT mark is represented by T 0 , (i) after a delay time T d1 ′T from T 0 , α 1 ′T is generated, then, (ii) within i=2 to m, β i−1 ′T and α i ′T are alternately generated in this order, while β i−1 ′+α i ′ is between 1.8 and 2.2 (provided that at i=2 and/or i=m, β i−1 ′+α i ′ may be deviated from about 2 within a range of ±2, and when m≧4, β i−1 ′ and α i ′ take constant values βc and αc, respectively, within i=3 to m−1), and then, (iii) β m ′T is generated, and with the same m, for a record mark of n=2m and a record mark of n=2m+1, T d1 =T d1 ′, α 1 =α 1 ′, β 1 =β 1 ′ and α m ≠α m ′, and at least one set selected from (β m−1 and β m−1 ′) and (β m and β m ′) takes different values.