| 摘要 |
PROBLEM TO BE SOLVED: To prevent the variation in head characteristics, and the geometric dimensions of the pattern on the medium, the degradation in head yield due to a defect etc., of the medium, and the degradation in device yield, in a magnetic recording and playback device mounted with a patterned medium. SOLUTION: A set ECC length when the number of sectors higher in decryption error ratio than a threshold is equal to or lower than N sectors, is assumed to be A byte, when the number is N+1 to N+M sectors, the length is assumed to be B byte, and when the length is equal to or above the N+M+1 sectors, the length is assumed to be C byte. Here is defined M≥1 and A<B<C. When the number of the sectors higher in the decryption error ratio of Zone #1 than the threshold is k1(k1>N+M+1), and the number of the sectors higher in the decryption error ratio of Zone #2 than the threshold is k2(k2<N), and the number of the sectors higher in the decryption error ratio of Zone #3 than the threshold is k3(N+1<k3<N+M), ECC lengths of the respective zones are respectively C byte, A byte, B byte. The ECC length of each zone is determined in such a manner and thereafter, each zone is formatted by the prescribed ECC length. COPYRIGHT: (C)2009,JPO&INPIT
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