Patent ID: 7382708

Claim:
A data recording device which records a multi-level data to a recording medium, comprising: a modulator modulating the multi-level data into two or more data blocks; an inverter reversing a most significant bit of each data block output from the modulator; a first DC level calculation unit computing a DC level in each data block output from the modulator; a second DC level calculation unit computing a DC level in each data block output from the inverter; a DC level accumulation unit outputting a selected one of the DC level from the first DC level calculation unit and the DC level from the second DC level calculation unit; and a level determination unit determining an accumulated sum value of each DC level of the first and second DC level calculation units and the selected DC level of the accumulation unit, wherein the level determination unit causing a selected one of the modulator and the inverter to output a corresponding data block as an output data block, based on a result of comparison of a first accumulated sum value of the DC level of the first DC level calculation unit and the accumulation unit and a second accumulated sum value of the DC level of the second DC level calculation unit and the accumulation unit, and the level determination unit outputting a selected one of the first and second accumulated sum values to the accumulation unit as a new selected DC level, based on the result of comparison.