| 摘要 |
PURPOSE:To record information with accurately set recording light power by detecting a temperature of an optical disk by a temperature detector and controlling an output of a semiconductor laser in response to the temperature. CONSTITUTION:A rotary shaft 6 is inserted into a central hole 4 of an optical disk 1. A hub 3 is attracted to be fixed to a magnet 8, the disk 1 is fixed to a table 7, and rotatably driven by a motor 5. A temperature detecting flat surface coil 14 and an oscillation coil 15 are opposed, and space-coupled. The coil 14 is varied in shape in response to a shape change due to a temperature of the disk 1, and its inductance is varied, and hence a mutual inductance M at the time of space-coupling is changed in response to the temperature of the disk 1. An oscillating frequency is varied in an oscillator 16. The temperature of the disk is obtained by a temperature calculator 17, and a recording light power operator 18 outputs a laser drive signal so corrected as to be coincident with temperature characteristics of a recording film of the disk 1. |
