Real-time head-to-disk clearance measuring method and apparatus
AssigneeInternational Business Machines Corporation
InventorsHal Hjalmar Ottesen, Gordon James Smith
Life of this patent
Estimating the term…
Abstract
A method and apparatus for detecting changes in clearance between a read/write transducer and a data storage medium involves acquiring a readback signal from the data storage medium using the transducer, the readback signal comprising one or more isolated pulses, and detecting a change in spacing defined between the transducer and the data storage medium using a slope of an edge of one or more of the isolated pulses.
Claims36
A method of detecting changes in clearance between a read/write transducer and a data storage medium, the method comprising:
- acquiring a readback signal from the data storage medium using the transducer, the readback signal comprising one or more isolated pulses obtained from one or more Gray code locations of the data storage medium;
- and
- detecting a change in spacing defined between the transducer and the data storage medium using an area, a width or a slope of an edge of one or more of the isolated pulses.
An apparatus for detecting changes in a spacing defined between a transducer and a data storage medium, comprising:
- an analog-to-digital converter (ADC), the ADC converting an analog readback signal obtained from the data storage medium using the transducer to a corresponding digitized readback signal, the readback signal comprising one or more isolated pulses obtained from one or more Gray code locations of the data storage medium;
- a digital filter configured to filter the digitized isolated pulses;
- and
- a processor that computes the spacing change using an area, a width or a slope of an edge of one or more of the filtered isolated pulses.
A data storing system, comprising:
- a data storage disk;
- a plurality of transducers each supported by a support structure in proximity with the disk;
- an actuator that provides relative movement between the transducers and the disk, a spacing defined between the transducers and the data storage disk;
- an analog-to-digital converter (ADC), the ADC converting an analog readback signal obtained from the data storage disk using a selected one of the transducers to a corresponding digitized readback signal, the readback signal comprising one or more isolated pulses obtained from one or more Gray code locations of the data storage medium;
- a digital filter configured to differentiate the digitized isolated pulses;
- and
- a processor that computes the spacing change associated with each of the transducers using an area, a width or a slope of an edge of one or more of the isolated pulses.
A method of detecting changes in clearance between a read/write transducer and a data storage medium, the method comprising:
- acquiring a readback signal from the data storage medium using the transducer, the readback signal comprising one or more isolated pulses;
- and
- detecting a change in spacing defined between the transducer and the data storage medium using a slope of an edge of one or more of the isolated pulses.
Dependencies are inferred from the claim text.