Encoding unit and storage unit using the same

A storage unit which encodes and records data on a recording medium, said storage unit comprising:

• first means for inserting resynchronizing bytes between two data blocks within a data field when converting data coded by a predetermined modulation code which generates patterns having D.C. components into pulse width modulation data, said resynchronizing bytes having resynchronizing patterns and achieving synchronization when a clock slip occurs within the data field;
• second means for calculating a digital sum value for a predetermined data block, said digital sum value indicating a difference between a sum total of logic values "1" and a sum total of logic values "0" in the pulse width modulation data;
• third means for controlling said first means so that the resynchronizing bytes having resynchronizing patterns that minimize the digital sum value is inserted in a present data block;
• and
• recording means for recording the pulse width modulation data obtained by said first means on the recording medium.