Devices and methods for determining a critical rotation speed of an optical data carrier, monitoring a condition of an optical data carrier, and generating a reference signal

摘要

A device determines a critical rotation speed of an optical data carrier at which a critical deflection of said optical data carrier may occur. The device includes a drive unit, a measurement unit and a determination unit. The drive unit rotates the optical data carrier according to a sweep covering a predetermined range of rotation speeds. The measurement unit generates a measurement signal indicative of a distance between a surface of the optical data carrier and a reference position corresponding to the sweep. The determination unit determines the critical rotation speed of the optical data carrier by processing the measurement signal on the basis of at least one characteristic of the measurement signal.