| 摘要 |
PROBLEM TO BE SOLVED: To provide a detector which can reliably detect an optical disk housed or inserted in the equipment in use regardless of the thickness of the aluminum deposition formed on the optical disk. SOLUTION: In this detector of a disk 30, an optical disk 30 exists in the light path of a light emitting diode 31, and detects the presence or absence of the optical disk 30 by a change in an output of a photo-transistor 32 caused by the absence. In this case, the detector is configured so as to detect the optical disk 30 by utilizing the refraction of the optical axis of the light emitted by the light emitting diode 31 by letting the light emitting diode 31 emit light at an angleθ1 to the disk face of the optical disk 30 and also arranging a photo-transistor on the optical axis of the emitted light.
|
