Control method of piezoelectric actuator, position control equipment, and disk device

A position control device comprising:

• a piezoelectric actuator including a pair of electrode films and a piezoelectric film sandwiched between the electrode films;
• a power supply for applying voltage to the piezoelectric actuator;
• a position control unit for identifying a position control state in which position control is performed by displacing the piezoelectric actuator and a standby state that does not require the position control and for controlling the position;
• and
• a reverse low voltage control unit that, when the position control unit identifies the standby state of the piezoelectric actuator, sets a reverse low voltage that is directed opposite to a polarization direction of the piezoelectric film and is lower than a coercive voltage and a set time during which the reverse low voltage is applied, and transmits a power supply control signal to generate the set reverse low voltage for the set time to the power supply.

A disk device comprising:

• a disk on which information can be recorded;
• a head for performing at least one of recording and reproduction on the disk;
• and
• a position control device for controlling a position of the head on the disk,
• wherein the position control device includes:
• a piezoelectric actuator formed of a pair of electrode films and a piezoelectric film sandwiched between the electrode films;
• a power supply for applying voltage to the piezoelectric actuator;
• a position control unit for identifying a position control state in which position control is performed by displacing the piezoelectric actuator and a standby state that does not require the position control, and for controlling the position;
• and
• a reverse low voltage control unit that, when the position control unit identifies the standby state of the piezoelectric actuator, sets a reverse low voltage that is directed opposite to a polarization direction of the piezoelectric film and is lower than a coercive voltage and a set time during which the reverse low voltage is applied, and transmits a power supply control signal to generate the set reverse low voltage for the set time to the power supply,
• wherein, in the position control state of the position control device, the head is performing one of the recording and reproduction on the disk, and, in the standby state, the head is performing none of the recording and reproduction on the disk.