Cylinder servo circuit for head in disc recording arrangement

摘要

The circuit has a correction value computation stage which determines the radial deviation u of an eccentric circular head track w.r.t. the recording cylinder on a disc with a waveform u(theta) = Acos(theta) + Bsin(theta) in response to a variation in an angular variable theta for a single disc revolution. A correction variable computation stage determines the cosine and sine component amplitudes A and B from an eccentricity amplitude measured between the eccentric circular track and the recording cylinder. An Independent claim is also included for a disc recording arrangement with a cylinder servo circuit.