Seagate Technology Incorporated

Subrahmanyan Nagarajan

Zine-Eddine Boutaghou

Mark James Schaenzer

Dallas W Meyer

Ramesh Sundaram

Peter Raymond Segar

John L Brand

Jing Gui

Bruno Jean Marchon

Walter Wong

Joel William Hoehn

Daniel Paul Burbank

Beat G Keel

Huan H Tang

Bo Wei

Mary Cynthia Hipwell

Andreas Argyros Polycarpou

Dale E Egbert

David Gerard Wobbe

Jeffery K Berkowitz

Li Li

James Rex Staggers, Jr

Ramesh Sundram

A reader portion (,) of a magnetoresistive head is disclosed. The reader portion (,) includes a magnetoresistive read element (,) for reading information from a magnetic media (,) and a non-magnetic element (,) to detect and cancel thermal changes in the read head. A spacer (,) is positioned between the magnetoresistive read element (,) and the non-magnetic element (,). A plurality of electrical contacts (,) connect the magnetoresistive read element (,) and the non-magnetic element (,) to external circuitry.

Reader for a low-flying magnetoresistive sensor

A disc storage system includes a rotating disc and a transducer. The transducer is carried on a slider which is supported by an armature. The armature is used to move the slider radially across the disc surface whereby information may be read from or written to the disc surface of the transducer. The slider includes an air bearing surface which faces the disc surface. As the disc rotates, the air bearing surface causes the slider to &ldquo;fly&rdquo; over the disc surface. Pads are provided on the air bearing surface to improve operational characteristics of the system.

Slider having air bearing surface which includes pads for disk storage system

A disc drive, includes a base, a disc stack rotatably attached to the base, and an actuator assembly movably attached to the base. The actuator assembly also includes a bearing housing, head mounting arms, head suspensions attached to the head mounting arms and a head assembly attached to the head suspension. The disc drive also includes a hub having a cylindrical body. The hub includes a disc mounting flange on one end of the hub. A disc has an opening therein sufficient to allow the hub to fit within the opening of the disc. The disc has two substantially flat data surfaces. The disc also includes a disc clamping portion located near the opening in the disc. A clamp is used to attach the disc to the hub. At least one disc is placed onto the hub and onto the mounting flange of the hub. The clamp is then used to clamp the disc to the hub. The disc clamping portion includes features for accommodating differences in flatness between the disc surfaces, the mounting flange of the hub and the clamp. The features include a first raised feature which extends above the first data surface of the disc, and a second raised feature which extends above the second data surface of the disc. The features are either bumps or annular rings positioned on the disc mounting surface. The bumps or rings may be formed using a laser. The ring may also include a multiplicity of individual bumps. As the disc is clamped to the hub, the raised feature deforms to accommodate the mismatch in flatness between the disc surfaces, the mounting flange of the hub, and the clamp. The clamp may include a roughened disc clamping surface. The upper surface of the disc mounting flange may also be roughened.

Magnetic discs with raised features in the clamping area

An apparatus for detecting surface variations on a rotating disc includes a slider, suspension assembly, first surface variation sensor, second surface variation sensor, and a controller. The slider is adapted to fly over the disc. The suspension assembly is coupled to the slider to position the slider over the disc. The first surface variation sensor is disposed on the slider, and provides a first sensor signal based upon slider contact with one of the surface variations. The second surface variation sensor is disposed on the slider and spaced from the first surface variation sensor. The second surface variation sensor provides a second sensor signal based upon slider contact with the surface variation. The controller receives the first and second signals and calculates a position of the surface variation based upon the first and second sensor signals.

Thermal asperity detection head

Disc drive servo system employing thermal signals

A head slider for use in a disc drive data storage system includes a slider body substrate having a cavity formed therein. A transducer is positioned in the head slider such that walls of the cavity in the slider body substrate protect the transducer from contact with asperities on a surface of a data storage disc.

Head slider with partially recessed magnetoresistive element

A data storage disc having an improved landing zone for supporting a head gimbal assembly for takeoff and landing. The improved landing zone having a landing surface formed of a patterned surface structure. The patterned surface structure including contact surfaces formed generally flush with a disc surface and depressions formed into the disc surface at predefined spaced location and extending below the disc surface. The patterned surface structure reducing stiction for 'takeoff' of a slider from the disc surface and reducing interference of the slider and disc surface while flying over a transition zone at the edge of the data zone and landing zone.

Landing zone design for a magnetic disc

A tester for use in detecting asperities in a disc surface of a storage system includes a load arm having a proximal end and a distal end. The distal end of the load arm is positioned adjacent the disc surface. A slider is carried on the distal end of the load arm adjacent the disc surface. A thermal sensor is coupled to the slider and provides an electrical output in response to a thermal input due to interaction between the thermal sensor and asperity on the disc surface. Detection circuitry coupled to the thermal sensor detects the electrical output from the thermal sensor and responsively provides a detection output indicating the occurrence of an asperity on the disc surface.

Detection of asperities in recording surface of storage medium

A device for testing smoothness of a rotatable disc is disclosed. A slider body has a trailing edge surface and an air-bearing surface for gliding over a surface of the disc when the disc is rotating. A piezoelectric sensor is formed in the slider body, and a thermal asperity sensor is formed in the slider body and at least partially exposed to the air-bearing surface. A plurality of conductive vias extend from the trailing edge surface of the slider body into the slider body to contact the piezoelectric and thermal asperity sensors. A plurality of conductive bond pads are disposed on the trailing edge surface in contact with respective conductive vias.

Integrated piezoelectric and thermal asperity transducers for testing

An asperity height sensing head and method of using the same are disclosed. The head includes multiple magnetoresistive (MR) sensors carried by a first rail of a slider adjacent to the air bearing surface (ABS) and positioned a distance L.sub.p from each other. Asperity height estimating circuitry coupled to each of the multiple MR sensors detects a number N of the MR sensors which exhibit a change in resistance as a result of contact between the ABS and a first asperity on the surface of the disc. The asperity height estimating circuitry estimates the height H.sub.A of the first asperity as a function of the number N, as a function of the pitch angle .theta..sub.p , and as a function of the distance L.sub.p.

Growing community of inventors

Burnsville, MN, United States of America

Subrahmanyan Nagarajan