Patent ID: 8000054

Claim:
A control device that controls a heater which thermally expands a head towards a surface of a storage medium configured to store information, the head approaching the surface of the storage medium and reading the information from the storage medium to generate a reading signal, the control device comprising: an acquisition module configured to acquire a reading signal from the head under a plurality of heat amounts generated by the heater; a computation module configured to compute, from the reading signal obtained by the acquisition module, two or more kinds of characteristic values representing characteristics of the reading signal for each of the plurality of generated heat amounts by using at least one kind of algorithm; a contact determination module configured to determine whether or not the head contacts the storage medium, with respect to each of the two or more kinds of characteristic values computed by the computation module, on the basis of a change of the characteristic values for the heat amount generated by the heater; and an association determination module configured to determine an association of the distance between the head and the storage medium with the heat amount generated by the heater, using the heat amount generated when the contact determination module determines that the head contacts the storage medium with respect to any of the characteristic values is used as the heat amount generated by the heater when the head contacts the storage medium so that the distance between the head and the storage medium is considered to be zero.