Abstract: A dual PMR writer is disclosed wherein the better writer at outer diameter (OD) skew is paired with a suspension after dynamic performance (DP) spin stand testing so that the better writer is the inner writer formed closer to a recording disk center than the other writer. Accordingly, lower read write offset is achieved at OD skew and better area density capability is realized. Preferably, there is a symmetrical or substantially symmetrical air bearing surface design after lapping and spin stand testing to afford flexibility in pairing an up facing (UP) head configuration with an UP suspension, or a down facing (DN) head configuration with a DN suspension to enable the better writer to be the inner writer. The dual PMR writer may have a dual dynamic fly height heater on each side of a center plane separating the two writers to improve write gap protrusion in the better writer.

Abstract: The present invention provides a flux-guided head for use in a magnetic recording system, such as a disk drive. The head includes a write element that is capable of writing magnetic polarity transitions into the surface of a magnetic media, such as a magnetic disk, using vertical/perpendicular recording techniques. Further, a read element is provided that includes a magnetoresistive element that, when reading perpendicularly-recorded magnetic transitions from the surface of the magnetic media, produces a readback pulse signal having a substantially Lorentzian pulse shape.

Abstract: In bottom spin valves of the lead overlay type the longitudinal bias field that stabilizes the device tends to fall off well before the gap is reached. This problem has been overcome by inserting an additional antiferromagnetic layer between the hard bias plugs and the overlaid leads. This additional antiferromagnetic layer and the lead layer are etched in the same operation to define the read gap, eliminating the possibility of misalignment between them. The extra antiferromagnetic layer is also longitudinally biased so there is no falloff in bias strength before the edge of the gap is reached. A process for manufacturing the device is also described.

Abstract: In bottom spin valves of the lead overlay type the longitudinal bias field that stabilizes the device tends to fall off well before the gap is reached. This problem has been overcome by providing a manufacturing process that includes inserting an additional antiferromagnetic layer between the hard bias plugs and the overlaid leads. This additional antiferromagnetic layer and the lead layer are etched in the same operation to define the read gap, eliminating the possibility of misalignment between them. The extra antiferromagnetic layer is also longitudinally biased so there is no falloff in bias strength before the edge of the gap is reached. A process for manufacturing the device is also described.

Abstract: In bottom spin valves of the lead overlay type the longitudinal bias field that stabilizes the device tends to fall off well before the gap is reached. This problem has been overcome by inserting an additional antiferromagnetic layer between the hard bias plugs and the overlaid leads. This additional antiferromagnetic layer and the lead layer are etched in the same operation to define the read gap, eliminating the possibility of misalignment between them. The extra antiferromagnetic layer is also longitudinally biased so there is no falloff in bias strength before the edge of the gap is reached. A process for manufacturing the device is also described.

Abstract: A magnetic storage system is disclosed which has one or more rotating disks. In one embodiment, the system includes a first transducer and a second transducer operatively associated with a respective first surface or second surface. Each of the first and second surfaces has a data track with a data region and an embedded servo sector. The first transducer has a data reader which includes a first MR strip and a servo reader which includes a second MR strip. The first MR strip is electrically isolated from the second MR strip. The first transducer performs a servo reading operation of the servo sector while the second a transducer performs either a data writing operation to the data region or a data reading operation from the data region. Also disclosed is a method for reading within a magnetic storage system. The storage system includes a first magnetic surface, a data reader and a servo reader. The first magnetic surface includes a first data region and a first servo sector.

Abstract: A magnetic storage system capable of separating thermal signals from data signals is disclosed. The magnetic storage system includes a magnetic media and a head associated with the magnetic media. The head includes a magneto-resistive element which is biased by a modulated bias current. The modulated bias current modulates thermal signals to a first frequency and modulates data signals to at least a second frequency. A method of separating thermal signals from data signals read from a magnetic storage media is also disclosed. The method includes the steps of (1) providing a head for reading information from the magnetic storage media, the head having an MR element; and, (2) biasing the MR element with a modulated bias current.

Abstract: A magnetic storage device is disclosed. The magnetic storage device contains a magnetic media. Previously recorded information resides on tracks in the magnetic media. A transducer is used to read information from the magnetic media. The transducer includes a first read element and a second read element. The first and second read elements are both laterally and longitudinally offset from each other. A method of reading information stored on a track of a magnetic media is also disclosed. Information is read from the magnetic media using the first and second read elements to produce respective first and second analog read signals. The first and second analog read signals are an electrical representation of the information previously recorded on the track.

Abstract: A magnetic storage system capable of separating thermal signals from data signals is disclosed. The magnetic storage system includes a magnetic media and a head associated with the magnetic media. The head includes a magneto-resistive element which is biased by a modulated bias current. The modulated bias current modulates thermal signals to a first frequency and modulates data signals to at least a second frequency. A method of separating thermal signals from data signals read from a magnetic storage media is also disclosed. The method includes the steps of (1) providing a head for reading information from the magnetic storage media, the head having an MR element; and, (2) biasing the MR element with a modulated bias current.

Abstract: A method and apparatus are provided for maintaining file readback performance compensating for readback errors caused by head/disk interaction used with a data detection channel in a direct access storage device. A readback signal is sensed from at least one disk surface and a data channel error rate is detected responsive to the readback signal. The detected data channel error rate is compared with a first predetermined threshold value and a gain of a phase lock loop (PLL) in the peak data detection channel is optimized responsive to an identified data channel error rate with a first predetermined threshold value. The PLL gain is adjusted until a lowest error rate is detected. A failure warning for the direct access storage device is provided to a user when the detected PLL gain is greater than a predefined loop gain value.

Abstract: A magnetic field sensor uses four individual magnetoresistive spin valve elements electrically connected in a bridge circuit. The spin valve elements are lithographically formed on the same substrate with their free layers having their magnetization axes parallel to one another. An electrically conductive fixing layer is formed on the substrate but is insulated from the spin valve elements. The application of current through the fixing conductor during fabrication of the field sensor fixes the direction of magnetization of two of the pinned layers to be antiparallel to the direction of magnetization of the other two pinned layers. The bridge circuit output voltage is responsive to an external magnetic field in the plane of the sensor. By appropriate fixing of the direction of magnetization of the pinned layers during sensor fabrication, and appropriate connection to the input and output leads, the bridge circuit output voltage is a measure of either the magnetic field or field gradient.

Abstract: A data recording disk drive has an improved head-disk interface provided by a transducer carrier which is essentially a low-flying air-bearing slider that is also able to be in contact and near contact with the lubricant film on the disk. The slider has a front air-bearing surface in the form of a pair of equally-spaced air-bearing pads, a rear air-bearing pad, and a central nonair-bearing recessed surface which separates the front and rear air-bearing pads. The two front pads have a surface area greater than that of the rear pad and thus provide a positive pitch up of the slider. This causes the rear pad to also be pitched up so that air can flow beneath the rear pad to generate an air bearing in the rear portion of the slider. The presence of the central nonair-bearing region eliminates any lift in the central part of the slider, which allows for the low-flying height. The flying height of the rear pad of the slider above the disk is controlled by the width of the rear air-bearing pad.

Abstract: A contact magnetic recording rigid disk file utilizes a magnetoresistive (MR) sensor for reading data recorded on the disk. The disk file may be of the liquid-bearing type of contact recording with the MR sensor supported on the trailing end of a carrier which rides on the liquid bearing. The performance of the disk file is enhanced by including means for minimizing the effect of a discovered baseline read signal modulation. The modulation has been determined to be caused by variable cooling of the temperature-sensitive and temperature-elevated MR sensor by the disk, with the temperature variation being directly related to the variation in head-disk spacing caused by the waviness of the surface of the disk.

Abstract: A data recording disk drive has an improved head-disk interface provided by a transducer carrier which is essentially a low-flying air-bearing slider that is also able to be in contact and near contact with the lubricant film on the disk. The slider has a front air-bearing surface in the form of a pair of equally-spaced air-bearing pads, a rear air-bearing pad, and a central nonair-bearing recessed surface which separates the front and rear air-bearing pads. The two front pads have a surface area greater than that of the rear pad and thus provide a positive pitch up of the slider. This causes the rear pad to also be pitched up so that air can flow beneath the rear pad to generate an air bearing in the rear portion of the slider. The presence of the central nonair-bearing region eliminates any lift in the central part of the slider, which allows for the low-flying height. The flying height of the rear pad of the slider above the disk is controlled by the width of the rear air-bearing pad.

Abstract: A data recording disk file of the liquid-bearing type has an improved head-disk interface provided by a transducer carrier with new properties. The carrier supports a conventional head for reading and writing data to the disk. The carrier has an air-bearing surface near its front end, a ski pad near its rear end, and a plurality of ski feet or struts which support the air-bearing surface off the liquid film of the disk when the disk file is not operating. The air-bearing surface is in the form of a pair of air-bearing rails located forward and outboard of the rear ski pad so that no air-bearing effect occurs in the rearward region of the carrier to assure the skiing action of the rear ski pad. The struts are separated from the air-bearing rails to not interfere with their air-bearing performance and support the rails away from the liquid film on the disk.

Abstract: A data recording disk file of the liquid-bearing type has an improved head-disk interface provided in by a transducer carrier with new properties. The carrier supports a conventional head for reading and writing data to the disk. The carrier has an air-bearing surface near its front end, a ski pad near its rear end, and a plurality of ski feet or struts which support the air-bearing surface off the liquid film of the disk when the disk file is not operating. The air-bearing surface is in the form of a pair of air-bearing rails located outboard of the rear ski pad so that no air-bearing effect occurs in the rearward region of the carrier to assure the skiing action of the rear ski pad. As operational speed is approached the air-bearing lifts the struts off the disk and the rear ski pad is the sole ski foot on the liquid film.