| 摘要 |
PROBLEM TO BE SOLVED: To detect a position of a head by using a bit-patterned medium and a servo sector null pattern thereof.SOLUTION: A patterned recording medium comprises a segment and a null pattern formed in the segment. The segment comprises first and second rows of discrete magnetic elements separated by a non-magnetic material, and a row of non-magnetic material positioned between the first and second rows. The null pattern comprises consecutive groups of the discrete magnetic elements in the first and second rows of the segment. Each group in the first row has a magnetic polarity that is opposite the magnetic polarity of adjoining groups in the first row. Each group in the second row has a magnetic polarity that is opposite the magnetic polarity of adjoining groups in the second row. The sum of readback signals in these consecutive groups of the discrete magnetic elements is obtained in the first and second rows, separately. A demodulated position signal corresponding to a position of a head is generated based on the subtraction of one sum from the other. |
