US 2003/0067698 A1 · Fly height measurement for a disc drive

Abstract

A method of measuring fly height of a read/write head to form a fly height profile for use in measuring fly height of the read/write head relative to a disc of a disc drive. A fixed source write signal is applied to an inductive element of the read/write head, generating a magnetic flux field with a stray magnetic flux field portion. A magnetoresistive element of the read/write head couples with the magnetic flux field producing an initial field strength signal. As the disc rotates, the read/write head flies there above decreasing the density of the stray magnetic flux field portion thereby decreasing the amplitude of the field strength signal. The decreasing amplitude of the field strength signal is calibrated to a predetermined operating fly height profile to correlate fly height of the read/write head to the decreasing amplitude of the field strength field, which forms the fly height profile.

Claims24

Dependent claims

A method for measuring a fly height of a read/write head using a magnetic flux field including a stray magnetic flux field portion generated by a reader of the read/write head coupled to a writer of the read/write head to provide a fly height profile for a data storage device comprising steps of:

(a) providing a write signal to the writer;
(b) establishing an initial field strength value of the magnetic flux field;
(c) monitoring an intermediate field strength value of the magnetic flux field based on a change in flux density of the stray magnetic flux field portion of the magnetic flux field;
(d) detecting a final field strength value of the magnetic flux field;
(e) determining a field strength profile based on the initial field strength value, the intermediate field strength value and the final field strength value of the magnetic flux field;
and
(f) calibrating the field strength profile to a predetermined operating fly height profile to provide the fly height profile of the read/write head for the data storage device.

4 more elements

A data storage device comprising:

a basedeck supporting a spindle motor assembly;
a disc having a recording surface with an information track attached to the spindle motor assembly, the information track being for data storage;
an actuator assembly supported by the basedeck and having a read/write head rotationally positionable adjacent the recording surface, the read/write head comprising a read element for reading data from the information track and a write element for writing data to the information track;
and
a fly height profile of a read/write head determined by steps for measuring a fly height of the read/write head to provide the fly height profile for the data storage device.

2 more elements

Dependencies are inferred from the claim text.

Fly height measurement for a disc drive

Life of this patent

Fly height measurement for a disc drive

Life of this patent

Abstract

Claims24