Patent ID: 8089714
Filing Date: 2012-01-03
Classification: G11B

Abstract:
1. A deterioration detection method of a composite magnetic head having an MR (magnetoresistance effect) head as a read head in a magnetic disk inspection apparatus, the method comprising: detecting a resistance value of the MR head, wherein the resistance value is detected by a resistance value detecting circuit coupled to both terminals of the MR head; and measuring the resistance value of the MR head of the exchanged composite magnetic head through the resistance value detecting circuit, and storing a measured value into a memory as an initial value, wherein the resistance value of the MR head is measured through the resistance value detecting circuit in the inspection of the magnetic disk to compare the measured value with the initial value, and if the measured value is smaller than a predetermined value smaller than the initial value, or if the measured value is larger than a predetermined value larger than the initial value, it is determined that the head is deteriorated, wherein the resistance value of the MR head in the inspection of the magnetic disk is measured when the inspection of the magnetic disk is started by the magnetic disk inspection apparatus, when the inspection is retried during the inspection, when the inspection of the magnetic disk is completed, or after the inspection of the magnetic disk is completed, wherein the resistance value detecting circuit is provided at a reading/writing circuit of the magnetic disk inspection apparatus having a writing amplifier coupled to a writing head of the composite magnetic head and a reading amplifier coupled to the MR head, it is determined whether or not {(R−R0)/R0}×100 falls within a range of 20% where the measured initial value is R0 and the resistance value measured in the inspection of the magnetic disk is R, and it is determined if the measured value is smaller than a predetermined value smaller than the initial value, or if the measured value is larger than a predetermined value larger than the initial value.