Patent ID: 6437930
Filing Date: 2002-08-20
Classification: G11B

Abstract:
A method of detecting variations in a clearance distance between a magnetic read/write transducer and a magnetic recording medium, said magnetic recording medium having a clearance detection burst recorded thereon, the clearance detection burst comprises at least two groups of bit patterns each having different transition densities, the method comprising the steps of:obtaining a readback signal from the at least two groups of bit patterns, the readback signal being sensitive to variations in said clearance distance; detecting a first amplitude (A1) of the readback signal of a first group of said at least two groups of bit patterns, detecting a second amplitude (A2) of the readback signal of a second group of said at least tow groups of bit patterns; and calculating a difference between the first and second amplitudes, (A1âˆ’A2), of the readback signals from the first and second groups; and dividing the calculated difference by the first amplitude such that the resultant amplitude change ratio, (A1âˆ’A2/A1), is indicative of the variation in the clearance distance.