Patent ID: 7417814

Claim:
A magnetic recording device comprising a magnetic recording medium; a read-write channel for modulating write data, writing it on said magnetic recording medium, reading data from said magnetic recording medium, and demodulating said read data; and a processor for supplying said write data to said read-write channel and being supplied with said read data from said read-write channel, wherein said processor supplies to said read-write channel a microdefect detection pattern having a first pattern for generating a consecutive magnetization inversion during writing and a second pattern for generating, during reading, a signal having a S/N ratio higher than the signal produced by said first pattern; said read-write channel modulates said microdefect detection pattern, writes it to said magnetic recording medium, reads said microdefect detection pattern, which was written, from said magnetic recording medium, conducts abnormality detection of a signal corresponding to said microdefect detection pattern, which was read out, and notifies the abnormality detection position on said magnetic recording medium to said processor when the abnormality was detected; and said processor registers said abnormality detection position, which was notified, as an unusable region.