Patent ID: 8144418
Filing Date: 2012-03-27
Classification: G11B

Abstract:
1. A test device for a magnetic storage device, comprising: a signal level receiver configured to receive a signal level corresponding with a level of a signal read from a magnetic disk through a magnetic head of the magnetic storage device from the magnetic storage device, at a first time when a power of an initial electric power amount substantially equal to or greater than 0 is supplied to a heater in the magnetic head and at a second time when the electric power supplied to the heater comprises the initial electric power after the electric power supplied to the heater has been increased from the initial electric power amount, a periphery of a head element in the magnetic head has been expanded due to heat from the heater, and the head element has been protruded toward a side of the magnetic disk of the magnetic storage device; wherein the signal level receiver is configured to request the magnetic storage device to read a signal from different positions on a same cylinder in the magnetic disk using the magnetic head at the first and the second time, to receive the signal levels corresponding with the signals read from the different positions at the first time and the second time, and to calculate an average value of the received signal levels at the time first time and the second time, and a determiner configured to determine whether plastic deformation has occurred in the periphery of the head element based on a difference between the average values calculated at the first and second times.