| 摘要 |
PROBLEM TO BE SOLVED: To normally control the recording power of a light source to be an optimum value in spite of change of environment when recording without using a high speed sampling circuit. SOLUTION: When an optical disk 20 is irradiated with light emitted from the light source before recording information, the signal level value of the reflection light is detected and is recoded/held as a reference level value, the signal level value of a reflection light from the optical disk 20 concerning the light from the light source is detected after information recording is started and the signal level value is compared with the reference level value, to adjust a driving current for emitting the light source based on the compared result, a CPU 13 selects so that the second light quantity level value of the reflection light from the optical disk 20 concerning the light from the light source is detected at a low digital modulation speed of the light source and the average value of the signal level values concerning the light from the light source is detected at a high digital modulation speed in the light source. |
