Apparatus for detecting whether information is recorded on a storage device.

摘要

In an apparatus for detecting whether or not an information signal is recorded on a storage disk, a light beam is allowed to scan an information track of the disk. The light beam is wobbled in a direction perpendicular to a longitudinal direction of the track (2) in response to a wobbling signal. A reproduced signal is derived from the light beam which was affected by the disk (1). A variation in amplitude of the reproduced signal is derived. A difference between the derived amplitude variation and the vibration signal is detected. A detection signal is generated which represents the detected difference.