| 摘要 |
PROBLEM TO BE SOLVED: To control writing light in such a manner that the improvement in recording and reproducing characteristics may be realized when an information recording medium is subjected to information writing. SOLUTION: When the information recording medium DVD-R is irradiated with writing light from a semiconductor laser LD, a photodetector PD detects this writing light and a binarization circuit 5 outputs a signal D5 to indicate the actual change in the intensity with time of the writing light. A recording signal D7 corresponding to the intrinsic writing information D6 from a strategy data extraction section 6 is formed and outputted. A phase comparison section 8 detects the phase difference between the signals D5 and D7 and a data forming section 1 for regulating recording pulses which is a regulating means regulates the information on the time width of the intrinsic writing information Din in accordance with the phase difference detection outputs D8 to D11 and forms compensation information D1. A laser drive section 3 drives the semiconductor laser LD in accordance with the compensation information D1. The semiconductor laser LD is most adequately driven by such feedback regulation so as not to be affected by the change in the environmental temperature and the change with lapse of time, by which the recording and reproducing characteristics to and from the information recording medium are improved. |
