1
Jagdeep S Buttar, David Terrill, Kenneth R Davies, Herman Ferrier, Xiaodong Che: Spin stand testing system with fine positioner for head stack assembly. Western Digital, Joshua C Harrison Esq, Carr & Ferrell, November 7, 2006: US07131346 (155 worldwide citation)

Head stack fixtures for securing head stack assemblies to spin stand testing systems, and spin stand testing systems incorporating such fixtures, are disclosed. Exemplary head stack fixtures comprise a base supporting a piezoelectric actuator. The base includes an attachment mechanism for securing t ...


2
David R Bryce: Magnetic document validator employing remanence and saturation measurements. Brandt, Shenier & O Connor, November 26, 1991: US05068519 (153 worldwide citation)

A method of and apparatus for determining the genuineness of a document such as a currency note printed at least in part with magnetizable ink in which there is produced a first signal as a measure of the saturation magnetization of a portion of the document printed with the ink and a second signal ...


3
Changhe Shang: Method and system for testing P2 stiffness of a magnetoresistance transducer at the wafer level. Western Digital, August 30, 2011: US08008912 (145 worldwide citation)

A method of testing P2 stiffness of a magnetoresistance (MR) sensor stack including a P2 pinned layer is provided. The method comprises the step of applying an external magnetic field to the MR sensor stack. The external magnetic field is oriented substantially perpendicular to a magnetic field of t ...


4
Charles S Stephens: Method and apparatus for differentiating battery types. Hewlett Packard Corporation, January 16, 1996: US05485090 (144 worldwide citation)

The cell type of a battery is determined by characterizing the series resistance behavior of various cell types to determine ranges of series resistance values exhibited by batteries of a particular cell type. The series resistance of a battery of unknown cell type is then measured. If the series re ...


5
Klaas B Klaassen, Jacobus C Leonandus van Peppen: Method and circuitry for in-situ measurement of transducer/recording medium clearance and transducer magnetic instability. International Business Machines Corporation, Henry E Otto, July 14, 1992: US05130866 (127 worldwide citation)

A method and circuitry are described for sensing the clearance between a magnetic transducer and a moving magnetic recording medium in a magnetic disk or tape storage system or alternatively sensing the degree of magnetic instability of a magnetic transducer in such a system. Magnetic transitions pr ...


6
Tim Danielson: Multi-Parameter eddy current measuring system with parameter compensation technical field. Kaman Instrumentation Corporation, McCormick Pauling & Huber, July 30, 1996: US05541510 (113 worldwide citation)

This invention uses a single eddy current coil to measure multiple parameters of conductive target simultaneously using a single fixed frequency. For example, the system consisting of the sensor coil, connecting cable, and signal conditioning electronics, can measure the thickness of a target and th ...


7
David R Bryce: Apparatus for detecting counterfeit currency using two coils to produce a saturating magnetic field. Brandt, Shenier & O Connor, August 16, 1988: US04764725 (113 worldwide citation)

Counterfeit detection apparatus in which the coils of the magnetic head are utilized to produce a saturating current for the paper currency being examined which is sufficient to bring the magnetic ink printed upon the paper currency close to the saturation point to greatly facilitate the detection o ...


8
Cyril Arthur Lee: Method and apparatus for authenticating a record medium consisting of applying two different strength magnetizing fields and monitoring the remanent fields. E M I, Fleit & Jacobson, July 26, 1977: US04038596 (110 worldwide citation)

Apparatus to examine a magnetic storage layer expected to contain a magnetic watermark includes means to magnetize the layer with a unidirectional field of a selected strength without saturating it and means to detect any distinct region of magnetic remanence. The apparatus may further include means ...


9
Shigeru Shoji: Eddy-current probe. TDK Corporation, Buchanan Ingersoll PC, March 14, 2006: US07012425 (95 worldwide citation)

An eddy-current probe according to the present invention comprises: a substrate having a first surface facing to a subject to be tested and a second surface opposite to said first surface; an exciting coil formed on the second surface, having a pair of current lines in parallel with each other throu ...


10
Tamon Kasajima, Masashi Shiraishi: Connection method for probe pins for measurement of characteristics of thin-film magnetic head and characteristic measurement method for thin-film magnetic head. SAE Magnetics, Buchanan Ingersoll PC, March 21, 2006: US07015689 (93 worldwide citation)

A method of connecting a plurality of probe pins to a plurality of first external connection pads, which are provided on a head gimbal assembly and are electrically connected to a plurality of terminal electrodes of a write magnetic head element, respectively, and a plurality of second external conn ...