| 摘要 |
PURPOSE: To perform the output power control of a semiconductor laser element corresponding to an utilizing environment by controlling the driving of a laser light source according to a detection temp. based on material coated on the surface of an optical recording medium and changing its colors according to temp. CONSTITUTION: An optical recording medium 10 is irradiated with the laser power from a semiconductor element 14. At this time, the temp. display part 26 of material coated on the medium 10 and changing its color according to temp. is read with a CCD camera 30 and a table 42 is referred to based on a chrominace signal corresponding to a temp. and then a correction data coefficient corresponding to the temp. is determined and the reference laser power from a memory means 44 is corrected according to the temp. with a multiplier 48. The corrected reference laser power is compared with the output power of the element 14 by a light receiver 16 in a comparator 20 and then the element 14 is controlled by feedback. Thus, the output power of the semiconductor element corresponding to the utilizing environment is optimally controlled. |
