Apparatus and method for generating write pulse for optical storage medium using ring oscillator

An apparatus for generating a write pulse to be written on an optical storage medium, comprising:

• a ring oscillator outputting n tap signals;
• a tap controller converting a signal to be written on the optical storage medium into a write signal having as long a cycle as an interval among the n tap signals, and converting and a channel clock signal into a channel clock signal having a cycle as long as the interval among the n tap signals, and outputting the write signal and the channel clock signal;
• a selector selecting two tap signals among the n tap signals as a write start signal and a write end signal, based on the write signal output from the tap controller, and outputting the two tap signals;
• and
• a pulse generator generating a write pulse connecting the write start signal and the write end signal by using the tap signals output from the selector and the result of comparing the write signal and the channel clock signal, which are output from the tap controller.

A method of generating a write pulse to be written on an optical storage medium, comprising:

• generating n tap signals having a predetermined phase difference;
• searching the n tap signals for a tap signal synchronized with a current channel clock signal, and calculating a tap count value and a tap interval of the tap signal in the current channel clock signal;
• calculating tap count values and tap intervals of a start signal and an end signal of a signal to be written;
• defining positions of a write start point and a write end point controlled at each of said tap intervals by using a tap count value and a tap interval of each of (a) the channel clock signal and (b) the signal to be written;
• and
• generating a write pulse connecting the write start point and the write end point.