Compensating track variation in magnetic disc systems

摘要

A number of magnetic discs (16) is arranged in a single stack and servo heads (12) and data heads (13) are moved radially by a positioning mechanism (9) using drive signals generated by a controller (CNT). The controller has a read/write unit (3), a track variation compensating unit (7a), a non-volatile memory (38A) and a head servo (5a). The servo control track head centre (12) provides a reference position which is used for positioning the data heads (14) over the discs. The servo data signals are compared to provide the centre and compensating values are determined.