| 摘要 |
PURPOSE: To stably record a signal regardless of the temp. of an optical disk. CONSTITUTION: When a signal is recorded on the optical disk 3, a chopper 18 is rotated, and the signal from a pyroelectric element 17 is supplied to a sensor amplifier 55, and is made a disk relative temp. signal TR to be supplied to a signal processing part 61. A device inside temp. signal TD is supplied from a device inside temp. detection sensor 59 to the processing part 61 through a sensor amplifier 60. A temp. detection signal TM is generated by the processing part 61 based on the signal TR and the signal TD. A switch 62 is turned on, and the signal TM is supplied to a reference control signal generation part 52. A reference control signal BC is generated by the generation part 52 based on a reference signal RE and the signal TM to be supplied to an output control part 51. A laser drive signal DR is generated by the control part 51 based on the signal BC and a monitor signal PM from a photodetector 37 to be supplied to a laser drive amplifier 53. A laser diode LD is driven by the signal DR. The output of the laser diode LD is controlled according to the disk temp. of the optical disk 3. |
