Patent ID: 7098820

Claim:
A data recording method for recording digital data in accordance with a digital modulation system for converting a data symbol having a first predetermined number of bits into a code symbol having a second predetermined number of bits that is larger than the first predetermined number of bits and placing merging bits between code symbols so as to generate record data whose run length is restricted, the method comprising the steps of: recording digital-sum-variation control data that causes digital-sum-variation values to deviate in a plus direction or a minus direction and read disability of data that is reproduced to take place in at least part of a recording region; placing special control data of two symbols or more after data in which the digital-sum-variation control data cannot be recorded due to a restriction on a data format of a recording medium; and causing the start bit of a code symbol of the digital-sum-variation control data immediately preceded by the special control data to be fixed regardless of whether the value at the beginning of the code symbol of the special control data is “0” or “1” so as to deviate the digital-sum-variation values in the plus direction or minus direction.