| 摘要 |
PURPOSE:To obtain a correct reproduced signal even though information are recorded on or reproduced from an optical disk provided with a light transmittance variable medium layer in high density. CONSTITUTION:After recording marks are recorded at a predetermined position on an optical disk 1 based on a testing signal generated from a testing signal generating circuit 29, recorded marks are reproduced with an optimum reproducing light intensity set previously. Then, the reproduced signal is converted into a reproduced signal voltage E1 corresponding to the mark length with a mark length -to- voltage converting circuit 24 to be outputted to a comparison circuit 25, further, a reference signal voltage E2 corresponding to the mark length of the recorded testing signal is outputted from a reference voltage generating circuit 26 to the comparison circuit 25. In the comparison circuit 25, the calculated result of an E2-E1 is outputted to a control circuit 32. The control circuit 32 adjusts the light intensity of a recording laser beam so that the result approaches nearest to a zero by using a light intensity adjusting circuit 28. |
