Patent ID: 7110197

Claim:
A method for determining a type of a head in a hard disc drive, where the head type is one of a normal head, a weak head having a poor write characteristic at a low temperature, and an ATE (Adjacent Track Erasure) head having an ATE effect, the head discrimination method comprising: writing data via the head under multiple tracks per inch (TPI) conditions, in which TPI is equal to a reference TPI, and wider and narrower than the reference TPI by respective first and second predetermined ratios, and reproducing the written data, to detect a bit error rate under each TPI condition; and comparing the bit error rates under the TPI conditions by comparing a first bit error rate under the condition of the reference TPI with a second bit error rate under the condition that the TPI is wider than the reference TPI by the first predetermined ratio, and comparing the second bit error rate with a third bit error rate under the condition that the TPI is narrower than the reference TPI by the second predetermined ratio, to determine the type of head.