International Business Machines Corporation

Other

Quantum Corporation

Alex Chliwnyj

David Lee Swanson

Steven Carter Wills

James Mitchell Karp

David Michael Davis

Dennis Hurley Byrne

William Louis Brodsky

George G Zamora

Robert Allen Hutchins

Will A Wright

John James Gniewek

Colleen Renee Stouffer

Ronald K Rhodes

Pamela Ruth Nylander-Hill

Scott Milton Fry

Christopher Robert Pandolfo

Ernest Stewart Gale

Robert Beverley Basham

Steven Ross Bentley

Steven Douglas Johnson

Sushama M Paranjape

Edward George Butt

James Francis Crossland

Dale A Christiansen

Mark Edward Hill

David C Graves

Loyal Keith Whitted

Wayne T Comeaux

James C Simkins

Robert C Baca

Habib M Torab

Katarina M Chliwnyj

Michael A Brewer

James W Wolf

Dennis Peter Rienstra

Tanya D Chliwnyj

Marco Dondi Baccigotti

John Raymond Haider

Noise in a same-gap, frequency-based servo tape system is reduced by applying correlated noise factors, generated during calibration, to filtered data write signals. The resulting noise values are subtracted from filtered servo signals, at frequencies Fand F, to generate first and second noise-compensated servo signals at frequencies Fand F. In one embodiment, the Fand Fdata signals are filtered through two SOBP filters which output the magnitudes of the signals. The Fand Fservo signals are similarly filtered. In another embodiment, the Fand Fdata signals are filtered through two Goertzel filters which output the real and imaginary components of the signals and the Fand Fservo signals are similarly filtered through two other Goertzel filters. Correlated noise factors are applied to the outputs of the write data Goertzel filters and the results subtracted from the corresponding outputs of the servo Goertzel filters.

Noise reduction in same-gap servo in frequency-based servo tape systems

A method is disclosed to calibrate a system receiving an input signal and generating an output signal. The method provides an input signal, and generates an output signal. The method establishes a sampling rate comprising a reference frequency, samples the input signal at said sampling rate, and samples the output signal at the sampling rate. The method then forms a measured input signal waveform, forms a measured output signal waveform, determines at (P) harmonics of the reference frequency the real components and the imaginary components of the measured input signal waveform, forms a filtered input signal waveform, determines at (P) harmonics of the reference frequency the real components and imaginary components of the measured output signal waveform, and forms a filtered output signal waveform. The method then calculates a transfer function comprising the mathematical relationship between the filtered output signal waveform and the filtered input signal waveform, and forms a calibration curve using that transfer function.

Apparatus and method to calibrate a system having an input signal and an output signal

An electromagnetic radiation emitting bulb, comprising a housing; one or more power input terminals disposed on that housing; a voltage converter disposed within the housing, where the voltage converter is electrically connected to the one or more power input terminals; and one or more electromagnetic radiation emitting devices disposed within the housing, where those one or more electromagnetic radiation emitting devices are electrically connected to the voltage converter. A method to emit electromagnetic radiation from a hand-carried device comprising an electromagnetic radiation emitting bulb and one or more battery cells. The method supplies first DC power having a first voltage from the one or more battery cells to the bulb, converts within the bulb the first DC power to second DC power having a second voltage, supplies within the bulb the second DC power to one or more electromagnetic radiation emitting /devices, and emits electromagnetic radiation.

Electromagnetic radiation emitting bulb and method using same in a portable device

An apparatus, system, and method are disclosed for determining brush contact with a magnetic head. A digitally generated signal is provided in a system and a first gain constant is adjusted without the brush in contact with the magnetic head until the signal achieves unity gain. A second gain constant is adjusted with the brush in contact with the magnetic head until the signal once again achieves unity gain. The difference between the first and second gain constants is calculated. If the difference satisfies a predetermined threshold, a monitoring message is provided indicating insufficient contact between the brush and the magnetic head. The message may serve to warn the user that the brush arm assembly may be inoperative or a failure message indicating that the entire brush assembly needs to be replaced.

Apparatus, system, and method for determining contact with a magnetic head in a tape drive

An electrical connection of a transfer station releasably, repeatably electrically couples with respect to a matching connection of a portable cartridge. A substrate in the portable cartridge has electrical contacts on a facing surface. In the transfer station, a matching circuitized flexible substrate has electrical contacts on a facing surface thereof, which are arranged to match the portable cartridge electrical contacts when in a face-to-face relationship. An elastomeric compression element, at the rear of the matching substrate, has individual protruding compression members contacting the rear surface and registered with corresponding individual electrical contacts. Elongated electrical contacts are registered with two adjacent individual compression members. A loader engages the portable cartridge, registering the cartridge substrate contacts in face-to-face relation with the matching flexible substrate electrical contacts, and exerting a normal force to the cartridge to compress the compression element and create non-wiping contact between the facing electrical contacts.

Releasable, repeatable electrical connection employing compression

A method to erase a magnetic tape, where the magnetic tape is first mounted in a magnetic tape in a tape drive, where that magnetic tape includes a physical beginning of tape ('PBOT'), a physical end of tape ('PEOT'), and information written thereon between the PBOT and the PEOT. The method then establishes one or more critical areas located on the magnetic tape, attempts to erase the information, and determines if each of the one or more critical areas have been erased. In the event each of said one or more critical areas have not been erased, Applicants' method provides an error message.

Apparatus and method to erase a magnetic tape

A system, method and an article of manufacture to provide more accurate magnetic tape servo operation are disclosed. Accurate measurements of the width of the servo pattern written on the magnetic tape are accomplished in the presence of relatively large motion of the magnetic tape. The accurate measurements of the width of the servo pattern are used to produce a corrected position error signal that provides improved servo track following to maintain the tape head at an optimal alignment for writing and reading data tracks on the tape.

Tape drive servo operation by use of servo pattern width measurements

A method and apparatus to calibrate a servo sensor disposed on a tape head located adjacent a moving magnetic tape is disclosed where that magnetic tape includes at least one servo edge comprising an interface between a first recorded signal and a second recorded signal, and where the servo sensor provides a servo signal, and where an independent position sensor provides an IPS signal. The method first samples the servo signal and the IPS signal, calculates a transfer function, and forms a first calibration curve. The method then forms an average residual error value. If that average residual error exceeds the maximum allowable residual error, then the method applies an offset to the first calibration curve to form a second calibration curve. That second calibration curve is saved for subsequent use during, for example, read/write/erase operations.

Apparatus and method to calibrate servo sensors in a noisy environment

An electrical connection releasably, repeatably electrically couples with respect to a matching connection of a portable cartridge. A substrate in the portable cartridge has electrical contacts on a facing surface of a flex cable termination mounted on a backing plate. A matching circuitized flexible substrate has electrical contacts on a facing surface thereof, which are arranged to match the portable cartridge electrical contacts when in a face-to-face relationship, and is mounted on a compression element with protruding compression members. Elongated electrical contacts are registered with two adjacent individual compression members. A loader exerts a normal force to the cartridge to compress the compression element and create non-wiping contact between the facing electrical contacts.

A data storage magnetic tape uses a volume control region (VCR) that contains all of the control information for the tape. There is a large span of blank tape after the VCR region before the actual data storage region of the tape. When a tape drive spools the tape between the VCR and data storage region, the tape motion is continued past the VCR region, after the VCR region is updated, into the region of tape where there is no data of any kind. Just before reaching the data storage region, the motion of the tape is reversed and the tape is rewound into the cartridge. The portion of the tape that experiences the motion reversal is prone to be thrown such that it protrudes from the other layers of uniformly layered tape. Even if these thrown wraps are damaged, this portion of the tape has no stored data, which increases the overall reliability of the information stored on the tape.

Apparatus and method for reducing data loss in tape media due to media edge damage on thrown wraps

Width of a write track for a magnetic tape head is measured by writing a foreground magnetic track signal on a magnetic tape having a dissimilar background signal. A magnetic tape read head is moved from beyond one edge, laterally across, and beyond the opposite edge of the foreground track signal. Logic detects the read head encountering the one edge and the opposite edge of the foreground track signal; and determines, from an independent position sensor, the width of the foreground track signal as the lateral distance between the lateral position of the read head at one edge, and at the opposite edge of the foreground track signal.

Measurement of write track width for magnetic tape head

A method to calibrate a transducer, whereby the transducer provides a first signal, and whereby a reference provides a reference signal. The first signal is sampled at a sampling rate comprising a reference frequency, and a digital measured first signal waveform is formed. The reference signal is sampled at the sampling rate, and a digital measured reference signal waveform is formed. The real and imaginary components of the measured first signal waveform are determined at (P) harmonics of the reference frequency. A filtered first signal waveform is formed using those real and imaginary components. The real and imaginary components of the measured reference signal waveform are determined at (P) harmonics of the reference frequency. A filtered reference signal waveform is formed using those real and imaginary components. A transfer function is formed using the filtered first signal waveform and the filtered reference signal waveform. A calibration curve is formed using that transfer function.

Apparatus and method to calibrate one or more transducers in a noisy environment

An electrical connection releasably, repeatably electrically couples with respect to a matching connection of a portable cartridge. A substrate in the portable cartridge has electrical contacts on a facing surface of a flex cable mounted on a backing plate. A matching circuitized flexible substrate has electrical contacts on a facing surface thereof, which are arranged to match the portable cartridge electrical contacts when in a face-to-face relationship, and is mounted on a compression element with protruding compression members. Elongated electrical contacts are registered with two adjacent individual compression members. A loader exerts a normal force to the cartridge to compress the compression element and create non-wiping contact between the facing electrical contacts.

A method to calibrate a servo sensor disposed on a magnetic tape head disposed adjacent a magnetic tape, where that magnetic tape includes at least one servo edge comprising an interface between a first recorded signal and a second recorded signal, whereby the servo sensor is capable of detecting that first recorded signal and that second recorded signal, and whereby an independent position sensor provides an IPS signal comprising the position of the tape head with respect to the tape path. Applicants' method determines and uses initial servo signal information and initial IPS signal information to determine an initial transfer function. That initial transfer function is used to determine a positioning signal where the tape head is alternatingly moved in a first direction and an opposing second direction along a first axis as the tape moves along a tape path such that the position of the magnetic head along the first axis as a function of time comprises a periodic function having the positioning signal. Additional servo signals and additional IPS signals are sampled. Those sampled signals are used to determine a second transfer function.

Apparatus and method to calibrate a servo sensor

A method to calibrate a servo sensor disposed on a magnetic tape head disposed adjacent a magnetic tape moving along a tape path. The method measures a maximum and a minimum servo signal ratio, establishes target maximum and minimum servo signal ratios, and determines if the measured servo signal ratios include the target ratios. If the measured servo signal ratios include the target servo signal ratios, then the method forms a filtered servo signal waveform using the measured servo signal waveform. The method then uses the filtered servo signal waveform to calculate a transfer function which is saved for subsequent track following.

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Tucson, AZ, United States of America

Alex Chliwnyj