OPTICAL DISK DEVICE

摘要

PROBLEM TO BE SOLVED: To solve the problems with a device for reproducing at least information on a recording medium that a focusing or tracking error signal which is a differential signal between reflected and transmitted light is used in order to detect whether the device is loaded with the recording medium or not and the kind of the recording medium and therefore the highly accurate judgment as to the presence or absence of the device is not possible in case of the occurrence of a change in detecting sensitivity or the circuit gain to detect the respective error signals is inadequate. SOLUTION: The reflected and transmitted light when an objective lens 7 is moved close to or distant from a disk 1 by a focus actuator 22-a across drive switching means 15 and focus driving means 16 from a focus up-down driving means 14 are detected and the presence or absence of the loading of the recording medium, the kind of the recording medium or the circuit gain for detecting the error signal is judged according to the result of the detection.