International Business Machines Corporation

W Stanley Czarnecki

Robert G Biskeborn

Calvin S Lo

Jason Liang

Ernest Stewart Gale

Philipp Herget

Icko E T Iben

Wayne Isami Imaino

David Berman

Said Abdullah Ahmad

Josephine F Kubista

Eric Rolf Christensen

Icko E Iben

Icko F Iben

Venus Hipolito

In one embodiment, a computer program product for determining a wrap angle includes a computer readable storage medium having program instructions embodied therewith, wherein the computer readable storage medium is not a transitory signal per se. The program instructions are executable by a processor to cause the processor to perform a method that includes receiving, by the processor, a measurement of a distance from an edge to a transducer, receiving, by the processor, a predefined height of tenting of a magnetic recording tape above the transducer, and determining, by the processor, a wrap angle for inducing tenting of the magnetic recording tape above the transducer at the predefined height when the magnetic recording tape passes over the edge in a direction of tape travel thereacross.

Methods for selecting wrap angle for inducing tape tenting above transducer

An apparatus according to one embodiment includes a magnetic head having at least two tunneling magnetoresistance sensors, where a resistance of a tunnel barrier of each of the tunneling magnetoresistance sensors of the magnetic head is about 25 ohms or less, a drive mechanism for passing a magnetic medium over the magnetic head, and a controller electrically coupled to the magnetic head. In addition, the controller includes a biasing circuit, where the biasing circuit restricts a maximum voltage drop across the tunnel barrier.

Shorting tolerant tunnel valve head and circuit

A tape drive, according to one embodiment, includes: a processor, and logic which is integrated with the processor, executable by the processor, or integrated with and executable by the processor. The logic is configured to: determine whether a difference between information and corresponding design values is in a range. The information corresponds to how an array of writers write and/or are expected to write to a magnetic medium during shingled recording. Moreover, the logic is configured to: compute, using the information, data describing a lateral writing position to use during writing such that shingled track edges are aligned according to a format in response to determining that the difference between the information and corresponding design values is not in the range.

Aligned shingled writing for magnetic recording media and media having shingle edge positioned tracks

In one embodiment, a method includes determining a distance from a to an edge closest thereto and selecting a wrap angle based on the determined distance for inducing tenting of a moving magnetic recording tape in a region above the transducer whereby a resulting tent of the moving tape extends from the edge closest thereto to a minima with a tent apex therebetween. In response to a determination to move the tape over the tape bearing surface, the method includes moving the tape over the tape bearing surface, and checking for changes in the tenting characteristics. In response to determining changes are present, the method includes sequentially selecting a different wrap angle based on the determined distance for inducing a desired tenting characteristic, and checking for changes in the tenting characteristics. Moreover, the method includes selecting a final wrap angle in response to determining no significant changes are present.

A method according to one embodiment includes running a magnetic recording tape over a tape bearing surface of a module having at least one edge, detecting signals from the tape at differing wrap angles for estimating a height of tenting of the tape above a transducer at each of the wrap angles, and selecting a wrap angle to provide about a predefined height of tenting of the tape above the transducer. A resulting tent of the moving magnetic recording tape extends from the edge of the module closest thereto to a minima with a tent apex therebetween, where the minima is at a first point of closest approach of the moving magnetic recording tape to the tape bearing surface of the module nearest the tent apex.

In one general embodiment, a method includes determining a distance from a transducer of a module to an edge of the module closest thereto, and selecting a wrap angle based on the determined distance for inducing tenting of a moving magnetic recording tape in a region above the transducer. In another general embodiment, a method includes running a magnetic recording tape over a tape bearing surface having at least one edge, and detecting signals from the tape at differing wrap angles for estimating a height of tenting of the tape above a transducer at each of the wrap angles. A wrap angle is selected to provide about a predefined height of tenting of the tape above the transducer.

A computer-implemented method, according to one embodiment, includes: determining, by the computer, whether a difference between information and corresponding design values is in a range. The information corresponds to how an array of writers write and/or are expected to write to a magnetic medium during shingled recording. Moreover, the computer-implemented method further includes: computing, by the computer and using the information, data describing a lateral writing position to use during writing such that shingled track edges are aligned according to a format in response to determining that the difference between the information and corresponding design values is not in the range.

A computer-implemented method for screening a multichannel head, according to one embodiment, includes measuring a channel signal to noise ratio value for each read transducer over a plurality of sense currents, wherein each transducer is one of a plurality of transducers in a multichannel head. The measured channel signal to noise ratio values are compared to a specification of a pre-defined value. The multichannel head is dispositioned to enable the multichannel head to perform to the specification of the pre-defined value, if possible.

Method for screening tunnel valve tape heads for magnetic noise

In one general embodiment, an apparatus includes a magnetic head having at least one tunneling magnetoresistance sensor. The resistance of the tunnel barrier of each tunneling magnetoresistance sensor is about 25 ohms or less. In another general embodiment, an apparatus includes a magnetic head having at least one tunneling magnetoresistance sensor. The resistivity of the tunnel barrier of each tunneling magnetoresistance sensor is less than a product of a target resistance of the tunnel barrier and an area of the tunnel barrier. The target resistance is about 25 ohms or less.

A method according to one embodiment includes recessing a portion of a media facing side of a module, the module having first and second transducers of different magnetic transducer types positioned towards the media facing side of the module, wherein the different transducer types are selected from a group consisting of data reader transducers, servo reader transducers, write transducers, piggyback read-write transducers and merged read-write transducers; wherein the recess is positioned towards one of the first transducers, wherein the recess forms a first protection structure for protecting the first transducer; and wherein the second transducer has either no protection or is protected by a second protection structure that is different than the first protection structure.

Method of forming magnetic recording head having protected reader sensors and near zero recession writer poles

A computer-implemented method, according to one embodiment, includes: collecting performance data corresponding to a tape drive and/or a magnetic tape head, storing the performance data in memory, and using the data to perform problem analysis. The performance data includes a resistance of the tape drive and/or magnetic tape head and a resolution of the tape drive and/or the magnetic tape head. Moreover, performing the problem analysis includes: determining a condition of the tape drive and/or the magnetic tape head, wherein the condition is selected from a group consisting of: wear, corrosion, defective leads and wire bonds. Other systems, methods, and computer program products are described in additional embodiments.

Using head and/or drive performance information for predicting and/or ascertaining failures

A computer program product, according to one embodiment, includes a computer readable storage medium having program instructions embodied therewith. The computer readable storage medium is not a transitory signal per se. Moreover, the program instructions readable and/or executable by a controller to cause the controller to perform a method which includes: determining, by the controller, whether a difference between information and corresponding design values is in a range; and computing, by the controller and using the information, data describing a lateral writing position to use during writing such that shingled track edges are aligned according to a format in response to determining that the difference between the information and corresponding design values is not in the range. The information corresponds to how an array of writers write and/or are expected to write to a magnetic medium during shingled recording.

A method according to one embodiment includes gathering information about how an array of writers write and/or are expected to write to a magnetic medium during shingled recording, and computing, using the gathered information, data describing a lateral writing position to use during writing such that shingled track edges are aligned according to a format. A method according to another embodiment includes obtaining a lateral offset from a nominal writing position, and applying the lateral offset for repositioning a writing position of an array of writers relative to a nominal writing position during writing in a first direction. A product according to one embodiment includes a magnetic recording medium; and data indicative of whether a lateral writing position offset was used while writing.

An apparatus according to one embodiment includes a module having first and second transducers of different transducer types positioned towards a media facing side of the module. The apparatus also includes a first protection structure for protecting the first transducer. The first protection structure includes a recessed portion of the media facing side adjacent the first transducer. The second transducer is protected by a second protection structure that is different than the first protection structure. The second protection structure includes a recessed portion of the media facing side adjacent the second transducer. An extent of recession of the recessed portion of the media facing side adjacent the second transducer is not as great as an extent of recession of the recessed portion of the media facing side adjacent the first transducer.

Magnetic recording head having protected reader sensors and near zero recession writer poles

A computer-implemented method according to one embodiment includes collecting, by the computer, performance data corresponding to a tape drive and/or a magnetic tape head. The performance data is stored in memory, and used by the computer to perform problem analysis. A computer-implemented method according to another embodiment includes collecting, by the computer, performance data corresponding to a tape drive and/or a magnetic tape head. The collected performance data is condensed to reduce a size of the collected performance data. The condensed performance data is stored in memory, and used to perform problem analysis.

Growing community of inventors

Palo Alto, CA, United States of America

W Stanley Czarnecki