| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problems that when noise of a semiconductor laser is reduced by superposing a high frequency component on a semiconductor laser driving current in a space formation period or space and mark formation period during a data recording operation, the high frequency component is overlapped with a mark formation start timing and a mark formation finish timing by a control circuit delay, etc., of the high frequency superposition, or a beginning end and finish end of the mark formed on a disk are fluctuated due to asynchronous nature of the high frequency component signal and a recording clock when the superposition is carried out till right before. <P>SOLUTION: A high frequency superposition control means is prepared, which stops the superposition of high frequency component preceding a predetermined period to the start timing and finish timing of the semiconductor laser driving current for the mark formation and again starts the superposition of high frequency component after the predetermined period. Thus, the fluctuation of the beginning end and finish end of the mark on the disk caused by the superposition of high frequency component can be evaded. As a result, prevention of jitter deterioration in high speed recording is attained. <P>COPYRIGHT: (C)2009,JPO&INPIT |
