Hitachi Global Storage Technologies Netherlands B.v.

Western Digital Technologies, Inc.

Panasonic Corporation of North America

Mike Wang

Jing Zhang

Jean-Claude Junqua

Yong Shen

Youping Deng

David Ernest Call

Ricardo Teixeira

Heng Gong

David Koo

A magnetic recording slider test system includes a host to collect test results and initiate concurrent testing of a plurality of magnetic recording sliders. Each of a plurality of first processing units is configured to test at least one element of a respective magnetic recording slider. In one aspect, the plurality of first processing units concurrently tests at least one element of respective magnetic recording sliders. In another aspect, a plurality of first signals is analyzed at respective first processing units, with each of the first signals representing a Direct Current (DC) output from one or more elements of a magnetic recording slider. Results determined from analyzing the first signals are sent to the host. In another aspect, a plurality of second processing units is configured to analyze second signals that each represent an Alternating Current (AC) output from one or more elements of the plurality of magnetic recording sliders.

Parallel testing of magnetic recording sliders

The patient device, designed for use by patients of reduced cognitive or physical ability, integrates with the network-based portal, designed for use by family members or nursing staff to customize the user experience of the patient. Using the portal the family member pushes user interface customizations as well as content and applications to be run on the patient device. The family member can also control the patient device remotely via the portal. The patient device collects usage data on the set of customizable interface components, and on the pushed content and applications. These data are sent as feedback to the portal, allowing the portal to show the family member which user interface features, content and applications are being used and which are not. Aggregate data collected via the portal generate ranking metrics used to aid in user interface feature selection.

Context dependent application/event activation for people with various cognitive ability levels

A triple track test for determining respective erase band widths associated with a read/write head involves writing first and second data tracks in each direction and at a certain distance from an origin, and erasing a track having a center at the origin. Based on a triple track test profile (3T) corresponding to the three tracks, a first distance is measured in one direction from the origin to one of the modified data tracks and a first erase band width is computed based thereon. The other side erase band width is computable similarly. A side erase amplitude loss measurement procedure, for determining the amount of signal amplitude lost by an adjacent track due to the respective erase bands, involves constructing a side-erase profile based on a composite of the 3T profile and a full-track profile, from which respective amplitude losses are computed for the respective erase bands.

Triple track test for side erase band width and side erase amplitude loss of a recording head

A method for calibrating a fly height adjustment device comprises flying a magnetic transducer coupled with a head gimbal assembly at a fly height from a magnetic recording data track. The magnetic transducer is coupled with a fly height adjustment device. Read-back signal amplitude is read from the magnetic recording data track with the magnetic transducer. The fly height is decreased with the fly height adjustment device. A linear fly height prediction is generated from the read-back signal amplitude and from power delivered to the fly height adjustment device as the fly height is decreased. The power delivered to the fly height adjustment device is compared with a difference between the linear fly height prediction and an implied fly height from the read-back signal amplitude, thereby calibrating the fly height adjustment device.

Fly height adjustment device calibration

One embodiment in accordance with the invention is a method for measuring a track width for a magnetic recording head comprising writing a first track and a second track on a disk at two different positions. Note that the first track is written at a frequency plus a frequency shift value while the second track is written at the frequency minus the frequency shift value.

Track width measurement for magnetic recording heads

A method for operating a tester for testing heads and disks of a magnetic recording disk drive during manufacturing calculates the readback signal amplitude asymmetry in the frequency domain without the need for measurement in the time domain with a peak detection channel. The tester first signals the write head to write a first pattern on the disk to generate a readback signal with positive pulses. The read head then detects this first recorded pattern and sends the readback signal to a spectrum analyzer connected to the tester. The tester then signals the write head to write a second pattern on the disk to generate a readback signal with negative pulses. The read head then detects this second recorded pattern and sends the readback signal to the spectrum analyzer. The spectrum analyzer measures the amplitudes of the first and second readback signals in the frequency domain using a bandpass filter. A controller in the tester calculates readback signal amplitude asymmetry from the measured amplitudes of the first and second readback signals.

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San Jose, CA, United States of America

Mike Wang