
US Patent No: 6,097,559
Number of patents in Portfolio can not be more than 2000
System and method for detecting head-to-disk contact in-situ a direct access storage device using a position error signal
Stats
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Aug 1, 2000
Issued date -
Jun 26, 1998
filing date -
09/105,368
serial no -
In Force
status
Importance
Abstract
An apparatus and method for detecting low flying read/write heads provides for the detection of contact between an air bearing slider/transducer assembly and a surface feature developed on a surface of a data storage disk. The apparatus includes a transducer disposed on an air bearing slider. An actuator is coupled to the slider/transducer assembly typically by employment of a head suspension assembly. The processor, in response to position error signals developed from servo information provided on the disk surface, moves the actuator and slider/transducer assembly to prescribed disk surface locations. The processor further processes non-repeatable position error signal values developed at a plurality of disk surface locations to detect an occurrence of contact between the slider/transducer assembly and a surface feature arising from the disk surface. Detecting the occurrence of a head-to-disk contact event generally involves acquiring position error signals from a first disk location and a second disk location using a particular transducer. The processor computes a power ratio value using a first power value and a second power value respectively derived from non-repeatable position error signals acquired from the first and second disk locations. The processor then compares the power ratio value with a power ratio threshold value, such that a power ratio value exceeding the power ratio threshold value indicates an occurrence of contact between the air bearing slider and a surface feature of the disk. The head-to-disk contact detection methodology of the present invention may be field upgradable in-situ a data storage system.
First Claim
Related Publications
International Classification(s)
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Cited Art
| Patent Info | (Count) | # Cites | Year |
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| 5,831,781 Method and apparatus for detecting flying height variation of head in disk storage system | 50 | 1996 | |
| 6,014,282 Magnetic disk apparatus and method of detecting head fault | 14 | 1997 | |
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| 5,901,001 Detection of asperities in recording surface of storage medium | 25 | 1996 | |
| 6,008,640 Detection and measurement of head disc interference using read back signal (without acoustic emission sensor or laser doppler vibrometer) | 39 | 1997 | |