Read error recovery method and apparatus
AssigneeMaxtor Corporation
InventorsBruce Emo, Quinn Haddock
Life of this patent
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Abstract
The present invention provides a method and apparatus for recovering data in a disk drive following a read error. At least a portion of the actuator arm tip is heated. Thermal expansion reduces the read-head-to-disk spacing, increasing the likelihood of success when a re-read of the data is attempted. In one approach, a heater is operatively coupled to the tip. In one aspect, a write head is provided with write current in order to heat the tip. Data which may be modified or overwritten when providing write current to the write head is preferably read and buffered prior to the write operation, for later re-writing to the disk.
Claims94
A disk drive apparatus, comprising:
- at least a first rotatable disk having data stored thereon in a plurality of tracks and sectors;
- at least a first arm, having a tip with a read head, positionable adjacent selectable locations of said disk and defining, at any given time, a head-to-disk spacing between said read head and said disk;
- and
- circuitry configured to detect a read error with respect to target data, and, in response, to heat said tip so as to cause a decrease in said head-to-disk spacing during at least a first re-read of at least some of said target data.
A method, usable in connection with a disk drive, comprising:
- providing at least a first rotatable disk having data stored thereon in a plurality of tracks and sectors;
- providing at least a first arm, having a tip with a read head, positionable adjacent selectable locations of said disk and defining, at any given time, a head-to-disk spacing between said read head and said disk;
- detecting a read error with respect to target data;
- in response to said detecting, heating said tip so as to cause a decrease in said head-to-disk spacing;
- and
- performing at least a first re-read of at least some of said target data during said decrease in said head-to-disk spacing caused by said heating.
A method of operating a disk drive that includes a head and a disk, the method comprising:
- detecting a read error in target data read from the disk using the head at a nominal flying height;
- heating the head in response to the read error, thereby decreasing the flying height of the head due to thermal expansion of the head;
- and
- re-reading the target data from the disk using the head at a decreased flying height due to the heating.
A method of operating a disk drive that includes a head and a disk, the method comprising:
- reading data from and writing data to the disk using the head at a nominal flying height during normal read and write operations;
- detecting a read error in target data read from the disk using the head at the nominal flying height;
- applying a write current to the head in response to the read error, thereby heating the head and decreasing the flying height of the head due to thermal expansion of the head;
- and
- re-reading the target data from the disk using the head at a decreased flying height due to the heating.
A method of operating a disk drive that includes a head and a disk, the method comprising:
- reading data from and writing data to the disk using the head at a nominal flying height during normal read and write operations;
- detecting a read error in target data read from the disk using the head at the nominal flying height;
- determining a portion of the disk in response to the read error;
- reading data from the portion of the disk using the head at the nominal flying height;
- storing the data from the portion of the disk in a buffer;
- then
- applying a write current to the head in response to the read error, thereby heating the head and decreasing the flying height of the head due to thermal expansion of the head and overwriting the data on the portion of the disk;
- then
- re-reading the target data from the disk using the head at a decreased flying height due to the heating, thereby providing a significantly higher probability of recovering the target data than re-reading the target data from the disk using the head at the nominal flying height;
- and
- writing the data from the portion of the disk to the disk using the head at the nominal flying height.
Dependencies are inferred from the claim text.