| 摘要 |
PURPOSE:To prevent deterioration in positioning precision due to a defect of the servo medium layer of a magnetic double-layered medium by stacking three stages of respective transducers for data recording and reproduction, servo signal reproduction I , and servo signal reproduction II, at the same place, and obtaining a sum signal of pieces of track servo information and positioning the transducer for data recording and reproduction. CONSTITUTION:Data is recorded and reproduced by the transducer 26, and servo information for positioning this transducer is detected by the transducers 28 and 30 dedicated to servo signal reproduction to detect the difference between the sum signals of the frequencies of respective tracks of the servo signals of the transducers 28 and 30 as a position error signal. Nonmagnetic layers 27 and 29 which are 10-100mum thick are interposed among transducers 25, 28 and 30 for data recording reproduction, servo signal reproduction I , and servo signal reproduction II to reduce the influence of the transducer 26 for data recording and reproduction upon the transducer 28 for servo signal reproduction until it can be ignored. |
