Seagate Technology Incorporated

Lin Zhou

Dongming Liu

Huiwen Liu

Dale E Egbert

Huazhou Lou

Peter John Gunderson

Jonathan Arland Nelson

Jianxin Zhu

Michael Thomas Johnson

Kenneth A Haapala

Scott Edward Ryun

Adam Karl Himes

Lee Clifford Knippenberg

Vincent Engelkes

John L Ibele

Lance Eugene Stover

Jason Wayne Riddering

Charles H Tolman

Shawn Stephen Silewski

Juil Lee

Kah Choong Loo

Cing Siong Ling

Apparatus and associated method that contemplates performing a first atomic force microscope (AFM) scan of a first region of a sample centered at a first position at a first angle to produce a first scan image, the first AFM scan including a first component scan at a first speed and a second component scan at a second speed; performing a second AFM scan of the first region of the sample at a second angle to produce a second scan image, the second AFM scan including performing a third component scan at the first speed and a fourth component scan at the second speed; and correcting a first error in the first scan image based on the second scan image to produce a corrected image output.

Atomic force microscopy of scanning and image processing

Using a high sample rate dPES, together with pulsed heater and lock-in technique, to improve dPES SNR for contact detection between the head and media surface. Steps of powering a transducing head actuator with pulsed input signal at a select data track offset from a previously-written to data track of the storage medium, where the pulsed input signal has select amplitude and duty cycle to simulate a response signal, and further locking in an amplitude with respect to the heater frequency, can lead to a determination of level of heater power for initiating contact between the transducing head and the storage medium.

High sample rate dPES to improve contact detection signal to noise ratio

An apparatus comprises a heat-assisted magnetic recording (HAMR) head, a sensor, and a controller. The HAMR head is configured to interact with a magnetic storage medium. The sensor is configured to produce a signal indicating the occurrence of head-medium contact. The controller is configured to receive the signal and concurrently determine from the signal if the occurrence of head-medium contact is caused by a first contact detection parameter, a second contact detection parameter, or both the first and second contact detection parameters.

Concurrent modulation and frictional heating head disk contact detection

In certain embodiments, a probe scans a surface to produce a first scan. The first scan is used to estimate a vertical offset for scanning the surface to produce a second scan. In certain embodiments, an AFM device engages a probe to a surface using a piezo voltage. The probe scans the surface to produce a first scan. The first scan is used to estimate a vertical offset such that the probe uses the piezo voltage to engage the surface for a second scan at a different vertical position.

Methods and devices for correcting errors in atomic force microscopy

A method and apparatus are provided for positioning a transducer relative to a track of a data storage medium and inducing lateral modulation of transducer the relative to the track. An element of the transducer is actuated toward the storage medium during the lateral modulation, and atomic interaction is detected between the element and the storage medium because of a change in a response to the lateral modulation of the transducer due to the atomic interaction.

Method and apparatus for detecting proximity contact between a transducer and a medium

The application discloses a sensor device to measure friction force at a head-media interface. As disclosed, the sensor device has a transducer element oriented to provide an electrical output responsive to force or strain imparted to the transducer element along an in-plane axis. Sensor circuitry is coupled to the transducer element to process the electrical output to provide an output measure of friction force. In illustrated embodiments, the head includes an actuator element which is powered on/off at an on/off frequency to cyclically protrude a localized portion of the head. The on/off frequency of the actuator is used by the sensor circuitry to detect excitation of the sensor device due to friction force at the head-media interface.

Friction force measurement assembly and method

A topographic profile of a structure is generated using atomic force microscopy. The structure is scanned such that an area of interest of the structure is scanned at a higher resolution than portions of the structure outside of the area of interest. An profile of the structure is then generated based on the scan. To correct skew and tilt of the profile, a first feature of the profile is aligned with a first axis of a coordinate system. The profile is then manipulated to align a second feature of the profile with a second axis of the coordinate system.

A method of detecting a contact between a transducing head and a storage medium is provided. The method applies an input signal, having a select power level and known frequency, to an actuator for actuating the head. An output signal is obtained in response to the input signal. At least one signal component is extracted from the output signal at the same or a harmonic of the same known frequency as the input signal applied to the actuator. Whether the at least one extracted signal component indicates a contact between the head and the medium is determined. The power level of the applied wave pattern is increased incrementally until the extracted signal component indicates a contact between the head and the storage medium.

Contact detection

In certain embodiments, a head-suspension assembly includes a resonator attached to either a head or gimbal. The resonator is configured to resonate at a predefined resonant frequency. In certain embodiments, disc drives includes a recording medium, a head-suspension assembly, and a resonator. The resonator is attached to either a head or gimbal of the head-suspension assembly. The resonator is configured to resonate at a predefined resonant frequency.

Methods and devices for head-media contact detection

An apparatus includes a head transducer configured to interact with a magnetic recording medium and a heater configured to thermally actuate the head transducer. A thermal sensor at or near the head transducer is configured to produce a sensor signal. Circuitry is coupled to the heater and configured to cause an oscillation in heater power. The heater power oscillation causes an oscillation in the sensor signal. A detector is coupled to the thermal sensor and configured to detect head-medium contact using the oscillating sensor signal and heater power.

Head-medium contact detection using introduced heat oscillation

A system that is capable of monitoring tribological data, such as friction, in a data storage device. In accordance with various embodiments, a magnetoresistive head is separated from a rotating data storage media by an air bearing and attached to a slider that is adjusted through deformation controlled by a heating element. A measurement circuit concurrently monitors friction from the head and power applied to the heating element to determine an MR head clearance. The measurement circuit includes at least a phase filter that eliminates off-phase friction from contributing to the determination of the MR head clearance.

Tribological monitoring of a data storage device

A method and associated apparatus for topographically characterizing a workpiece. The workpiece is scanned with a scanning probe along a first directional grid, thereby scanning a reference surface and an area of interest subportion of the reference surface, at a variable pixel density including a first pixel density outside the area of interest and a second pixel density inside the area of interest to derive a first digital file characterizing topography of the workpiece. The workpiece is further scanned along the reference surface and the area of interest with the scanning probe along a second directional grid that is substantially orthogonal to the first directional grid and at a constant pixel density to derive a second digital file characterizing topography of the workpiece. A processor executes computer-readable instructions stored in memory that generate a topographical profile of the workpiece in relation to the first and second digital files.

Variable pixel density imaging

An apparatus and associated method for topographically characterizing a workpiece. A scanning probe obtains topographical data from the workpiece. A processor controls the scanning probe to scan a reference surface of the workpiece to derive a first digital file and to scan a surface of interest that includes at least a portion of the reference surface to derive a second digital file. Correlation pattern recognition logic integrates the first and second digital files together to align the reference surface with the surface of interest.

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Eagan, MN, United States of America

Lin Zhou