Method and apparatus for optical disk recording capable of reducing settling time and generating an accurate channel clock signal

An optical disk recording apparatus which records information on a recordable optical disk employing constant angular velocity recording method and generates a write reference clock signal used for obtaining recording timing in a data-recording operation on the optical disk, the apparatus comprising:

• first comparing means for comparing phases and frequencies between a frequency-divided signal of a predetermined reference clock signal input from outside and a frequency-divided signal of the write reference clock signal, and for outputting a first error signal representing comparison results;
• second comparing means for comparing phases and frequencies between a first signal recorded beforehand on the optical disk and the frequency-divided signal of the write reference clock signal, and for outputting a second error signal representing comparison results and a first frequency differential signal representing a frequency difference;
• third comparing means for comparing phases and frequencies between one of the first signal and a second signal recorded beforehand on the optical disk and the frequency-divided signal of the write reference clock signal, and for outputting a third error signal representing comparison results and a second frequency differential signal representing a frequency difference;
• selection means for selecting any one of the first through third error signals output from the first through third comparing means, respectively, and for exclusively outputting the signal selected;
• control voltage generating means for generating a control voltage from the signal output from the selecting means, and for outputting the control voltage;
• voltage control oscillating means for generating and outputting the write reference clock signal having a frequency corresponding to the control voltage input from the control voltage generating means;
• and
• control means for controlling operations of the selecting means according to the first and second frequency differential signals.

A method of recording information on a recordable optical disk employing a constant angular velocity recording method and generating a write reference clock signal used for obtaining recording timing in a data-recording operation on the optical disk, the method comprising the steps of:

• first comparing phases and frequencies between a frequency-divided signal of a predetermined reference clock signal input from outside and a frequency-divided signal of the write reference clock signal to output a first error signal representing comparison results;
• second comparing phases and frequencies between a first signal recorded beforehand on the optical disk and the frequency-divided signal of the write reference clock signal to output a second error signal representing comparison results and a first frequency differential signal representing a frequency difference;
• third comparing phases and frequencies between one of the first signal and a second signal recorded beforehand on the optical disk and the frequency-divided signal of the write reference clock signal to output a third error signal representing comparison results and a second frequency differential signal representing a frequency difference;
• selecting any one of the first through third error signals output from the first through third comparing steps, respectively;
• generating a control voltage from the signal selected in the selecting step;
• generating the write reference clock signal having a frequency corresponding to the control voltage input in the controlling step;
• and
• controlling operations of the selecting step according to the first and second frequency differential signals.