Data storage device detecting free fall condition from disk speed variations
AssigneeWestern Digital Technologies, Inc.
InventorsWei Guo, Jianguo Zhou, Yiming Chen, Guoxiao Guo, Jie Yu
Life of this patent
Estimating the term…
Abstract
A data storage device is disclosed comprising a disk comprising data, and a head actuated over the disk. A timing signal is generated by reading the data from the disk, and a frequency generator is adjusted based on the timing signal to generate a disk locked clock substantially synchronized to a rotation speed of the disk. A free fall condition is detected based on the timing signal, and when the free fall condition is detected the head is parked.
Claims32
A data storage device comprising:
- a disk comprising data;
- a head actuated over the disk;
- and
- control circuitry configured to:
- generate a timing signal by reading the data from the disk;
- adjust a frequency generator based on the timing signal to generate a disk locked clock substantially synchronized to a rotation speed of the disk;
- detect a free fall condition based on the timing signal;
- and
- park the head when the free fall condition is detected.
A data storage device comprising:
- a disk;
- a head actuated over the disk;
- and
- control circuitry configured to:
- generate a speed signal representing a rotation speed of the disk;
- detect a free fall condition based on an absolute value of the speed signal, a derivative of the speed signal, and an integral of the speed signal;
- and
- park the head when the free fall condition is detected.
A method of operating a data storage device comprising, the method comprising:
- generating a timing signal by reading data from a disk;
- adjusting a frequency generator based on the timing signal to generate a disk locked clock substantially synchronized to a rotation speed of the disk;
- detecting a free fall condition based on the timing signal;
- and
- parking the head when the free fall condition is detected.
A method of operating a data storage device, the method comprising:
- generating a speed signal representing a rotation speed of a disk;
- detecting a free fall condition based on an absolute value of the speed signal, a derivative of the speed signal, and an integral of the speed signal;
- and
- parking the head when the free fall condition is detected.
Dependencies are inferred from the claim text.