Information recording/reproducing method, with recorded sub-data

An information recording method for use with an information recording medium for recording main data by forming a pit row or a mark row to the information recording medium by irradiating the information recording medium with a beam for recording, said information recording method comprising:

• generating a first modulating signal in correspondence with the pit row or the mark row;
• generating a second modulating signal by modulating the first modulating signal by sub-data such that a pit or a mark of the pit row or the mark row is locally changed in accordance with a logical level of the sub-data;
• and
• modulating the beam for recording by the second modulating signal;
• wherein the generating the second modulating signal generates the second modulating signal by allocating one bit of the sub-data to the pit row or the mark row, the pit row or the mark row having a predetermined minimum length to which one bit of the sub-data is allocated that is a length by which the sub-data is correctly reproduced in a case in which the main data is correctly reproduced by an error correction code and a length by which the area to which one bit of the sub-data is allocated can be detected by optical observation;
• wherein the generating the second modulating signal comprises:
• generating a binary coefficient row with the first modulating signal as a reference;
• generating a disturbing signal by disturbing the sub-data by the binary coefficient row;
• and
• generating the second modulating signal by modulating the first modulating signal by the disturbing signal;
• and
• wherein the generating the binary coefficient row generates at least a first and a second one of the binary coefficient rows, the generating the disturbing signal generates a first and a second one of the disturbing signals by disturbing a first and a second one of the bit rows by the sub-data respectively by the first and the second binary coefficient rows and generates the disturbing signal by multiplexing the first and the second ones of disturbing signals.