Patent ID: 8054567
Filing Date: 2011-11-08
Classification: G11B

Abstract:
1. A measuring method for measuring a write width and/or a read width of a composite magnetic head having a write head and a read head by obtaining a read characteristics of the composite magnetic head, comprising the steps of writing test data over at least two tracks corresponding to an eccentricity by the write head by positioning the composite magnetic head under an ON track servo control by reading a servo information from a designated track of a rotating magnetic recording medium of a discrete track system, a rotating magnetic recording medium of a bit pattern system or a rotating magnetic recording medium having other uneven recording layer and driving the composite magnetic head by giving the eccentricity for accessing at least two tracks for one revolution to the composite magnetic head, reading the test data in the at least two tracks by the read head under the ON track servo control while rotating the magnetic recording medium and moving the composite magnetic head in the radial direction by a pitch smaller than a distance between the two tracks by the one revolution from before the designated track to after or vice versa to cover an area in which the test data is written by the writing, and calculating the write sensitive width or the read sensitive width by obtaining a read characteristics profile having a peak of a read voltage for the moving distance of the composite magnetic head in the radial direction on the basis of the read signal of the read head.