Patent ID: 8400725

Claim:
A storage device, comprising: a recording medium for recording data; a driving module configured to drive and rotate the recording medium; a head comprising a reader for reading data from the recording medium and a writer for writing data to the recording medium, and configured to float over the recording medium, wherein the recording medium is configured to be driven and rotated by the driving module; a conductor on the head and configured to change a projection amount of the head relative to the recording medium by thermally expanding the head with heat due to an electrical current passing through the conductor; a write-verify module configured to check whether content written in an location on the recording medium by the head is correct, after the driving module starts rotating the recording medium from a rotation-stopped state; and a projection amount controller configured to control the projection amount of the head by adding a value corresponding to the check by the write-verify module to an electrical current in a steady state passing through the conductor, wherein the projection amount controller is configured to control the projection amount of the head by adding a first value to the electrical current in the steady state passing through the conductor if the content is correct according to the check by the write-verify module, and configured to control the projection amount of the head by adding a second value greater than the first value to the electrical current in the steady state passing through the conductor if the content is not correct according to the check by the write-verify module.