Abstract: A method and device are disclosed for improving reliability of reading an optical storage medium, such as an optical disc (20). A disc spin speed value (31) of the optical disc (20) is provided and an unnormal value of said disc spin speed value (31), which differs from a disc spin speed value within a range of nominal disc spin speed values, is detected, indicating normal spinning operation of said optical disc (20). By using this method, the spinning loss of an optical disc, e.g. due to insufficient disc clamping force, is detected fastly and reliably, in a manner resulting in a reduced risk of damaging the disc and disc reader during such spinning loss. Further actions may be taken in both cases, including disabling the drive in order to prevent damage of the disc or to thwart such illegal usage.

Abstract: A method and device are disclosed for improving reliability of reading an optical storage medium, such as an optical disc (20). A disc spin speed value (31) of the optical disc (20) is provided and an unnormal value of said disc spin speed value (31), which differs from a disc spin speed value within a range of nominal disc spin speed values, is detected, indicating normal spinning operation of said optical disc (20). By using this method, the spinning loss of an optical disc, e.g. due to insufficient disc clamping force, is detected fastly and reliably, in a manner resulting in a reduced risk of damaging the disc and disc reader during such spinning loss. Further actions may be taken in both cases, including disabling the drive in order to prevent damage of the disc or to thwart such illegal usage.

Abstract: In a CD drive 100, a tracking subsystem comprising tracking detector 330, a control processor 310 and tracking actuator assembly 340, is coupled to photodiodes A-F, to have the lens assembly 200 track a data track 140 on a disc 105. A vibration detector subsystem comprising a vibration detector 350, the control processor 310, and the speed setting function 315, is also coupled to photodiodes A-F, and the vibration detector subsystem disables the tracking subsystem and detects vibration of the lens assembly 200 at a resonant speed.