| 摘要 |
There is described apparatus (800) to decode longitudinal position (LPOS) information from non-shifted servo elements (a1, a4, a7) and an unbroken sequence of plural shifted servo elements (a2-a3, a5-a6), variations in the relative displacement of the non-shifted and shifted elements encoding the LPOS information. The apparatus is operable to receive signals (905) from a transducer head apparatus (131) that detects the servo elements as they move past the transducer head apparatus, and to process the signals to obtain data (L1, L4, L5, L8) related to relative displacement of mutually adjacent shifted and non-shifted elements within respective ones of the servo bursts, and data (L2, L3, L6, L7) related to relative displacement of mutually non-adjacent shifted and non-shifted elements within the respective ones of the servo bursts, and also to process the data to determine LPOS bit values corresponding to the respective ones of the servo bursts. |
