G11B 5/59677

Disposition or mounting of heads {or head supports} relative to record carriers {; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed } with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for track following on disks {with optical servo tracking}