Dynamic track pitch control for shingled magnetic recording (SMR)

A method of operating a Shingled Magnetic Recording disk drive comprising:

• measuring a current magnetic write width by performing test writes and reads in the thin film magnetic media on a disk;
• and
• selecting a track pitch for a next shingled write operation, the track pitch being a positive function of the current magnetic write width that compensates for increases in the current magnetic write width by increasing the track pitch up to a maximum track pitch that is selected for a maximum current magnetic write width and compensates for decreases in the current magnetic write width by decreasing the track pitch to a minimum track pitch that is selected for a minimum current magnetic write width, wherein the selected track pitch compensates for changes in the current magnetic write width.

A method of operating a Shingled Magnetic Recording disk drive comprising:

• measuring a current magnetic write width by performing test writes and reads in the thin film magnetic media on a disk using a first set of writing parameters;
• and
• adjusting the current magnetic write width to conform to a predetermined value by adjusting one or more writing parameters.

A Shingled Magnetic Recording disk drive comprising:

• temperature sensor for measuring a selected temperature representing magnetic media temperature on a disk;
• and
• a track pitch adjustment unit that adjust the track pitch by selecting a track pitch value for a next write operation using the selected temperature, the selected track pitch value being a positive function of the selected temperature up to a maximum track pitch value that is selected for a maximum temperature and wherein a minimum track pitch value is selected for a minimum temperature, and the selected track pitch value results in a partial overlapping of a previously written track by the next write operation.

A Shingled Magnetic Recording disk drive comprising:

• magnetic media on a disk organized into at least one unshingled region and one shingled region;
• and
• a track pitch adjustment unit that adjusts the track pitch by selecting a track pitch value for a next shingled write operation in the shingled region using a measured magnetic write width value determined by writing and reading test data in the magnetic media, the selected track pitch value being a positive function of the measured magnetic write width value up to a maximum track pitch that is selected for a maximum measured magnetic write width value and where a minimum track pitch is selected for a minimum measured magnetic write width, wherein the selected track pitch value compensates at least in part for changes in the magnetic write width value.

A Shingled Magnetic Recording disk drive comprising:

• magnetic media on a disk organized into at least one unshingled region and one shingled region;
• and
• a magnetic write width adjustment unit that adjusts the magnetic write width by selecting write parameters for a next shingled write operation in the shingled region by measuring a first magnetic write width value determined by writing and reading test data in the magnetic media using a first set of write parameters, and then selecting a second set of write parameters to adjust the magnetic write width value to correspond to a predetermined target value.