Recording clock generating device and method thereof

A recording clock generating device for recording data to an optical disk having a recording groove wobbled at a specific frequency in the radial direction, and prepits formed at a unit interval including a specific number of wobble periods, said device comprising:

• a wobble signal detector for detecting recording groove wobble and outputting a wobble signal;
• a period averaging arrangement for obtaining an average period for periods of the wobble signal;
• a timer for generating a rectangular wave with a period which is substantially equal to the average period obtained by the period averaging arrangement;
• a frequency multiplying PLL for multiplying timer output and generating a recording clock;
• and
• a phase difference measuring set for measuring a phase difference Z between the wobble signal and the rectangular wave;
• wherein the period averaging arrangement has
• a set for measuring a total time of N wobble signal periods, where N is a specific integer and holding the measured total time as a cumulative period V, and
• a set for measuring a next wobble period X, subtracting (1/N) of the cumulative period V from the cumulative period V, adding X to the resultant difference, correcting the measured phase difference Z, and using the resultant sum as a new total time for the N periods.