Hard disk drive idle sweep for thermal asperity avoidance

A controller circuitry for a hard disk drive wherein a band spans the data storage area of a disk medium, the controller circuitry storing or accessing one or more sequences of instructions which, when executed by one or more processors, cause performance of:

• while in an idle state not performing a data operation,
• performing a first seek operation from a particular first equivalent sub-band position that a head slider is flying over the disk medium to an adjacent second equivalent sub-band position over the disk medium;
• and
• performing a second seek operation from the second equivalent sub-band position to an adjacent third equivalent sub-band position over the disk medium.

A hard disk drive (HDD) comprising:

• a disk medium rotatably mounted on a spindle, wherein a band spans the data storage area of the disk medium;
• a head slider housing a read-write transducer configured to read from and to write to the disk medium;
• means for moving the head slider to access portions of the disk medium;
• and
• an electronic controller configured to control the means for moving, the controller configured for causing performance of:
• while in an idle state not performing a data operation,
• performing a first seek operation from a particular first equivalent sub-band position that a head slider is flying over the disk medium to an adjacent second equivalent sub-band position over the disk medium, and
• performing a second seek operation, in a same first radial direction as the first seek operation, from the second equivalent sub-band position to an adjacent third equivalent sub-band position over the disk medium.