International Business Machines Corporation

Quantum Corporation

Terralux, Inc.

John Alexander Koski

Nhan Xuan Bui

Kazuhiro Tsuruta

Akimitsu Sasaki

Timothy C Hughes

Glen Alan Jaquette

James Mitchell Karp

Anthony W Catalano

Steven Carter Wills

Junichi Fukuda

Jay Eunsuk Lee

Daniel Stewart Husky

Keisuke Tanaka

Randy Clark Inch

Paul Y Hu

Brett James Pardikes

James E Smith

Brian Eldin Brandt

James J Howarth

James Francis Crossland

Don G East

Spencer D Roberts

Rudolf W Lissner

Matthew V Ball

Joe L Garcia

Richard B Weaver

Various systems and methods facilitate internal communication within a lighting module as well as intercommunication among lighting modules over an external network. The network may be a conventional network managed by a central network controller or may be an ad hoc or 'mesh' network&#x2014;i.e., a scalable network architecture in which any lighting module is a node that can communicate with any other module or network-connected device.

Communication with lighting units over a power bus

A first entity communicates with a second entity over a shared power bus by switching the bus to a high-impedance state and modifying the voltage on the power bus, in accordance with an outgoing communication, such that the modified voltage is detected by the second entity and the communication is received thereto.

An apparatus and method for providing a unique identifier for data storage media is disclosed herein. The servo track of the data storage media is encoded one or more times with media manufacturer's data. The media manufacturer's data includes a variety of information including the unique identifier. The unique identifier differentiates among different media manufacturers, different spools or pancakes from which a given media comes from, and different media within a given spool or pancake. The unique identifier scheme is configured to facilitate standardization among media manufacturers while providing error correction and flexibility for future changes in format.

Unique media identifier

Methods and systems for sensing a position of a transducer head with respect to a storage medium. One method includes generating a read signal from a servo track stored on a magnetic storage medium. The servo track includes servo frames of magnetic flux transitions forming detectable servo marks, the servo marks forming a tone field of repeating servo marks oriented at a first azimuth angle and a mid-frame synchronization mark incorporated within the tone field, wherein the tone field provides a metric reference for dimensional measurements between features within the servo frame(s). The number of servo marks in the tone field of each servo frame along a longitudinal direction of the servo track before the mid-frame synchronization mark and after the mid-frame synchronization mark varies with lateral position.

Servo track having periodic frames of tone field and embedded synchronization marks

A method and apparatus for compensating for media shift due to spiral groove roller tape guide is disclosed. The lateral tape shift is measured. Then the control of the coarse actuator is adjusted for the lateral tape shift so that the movement of the coarse actuator follows the tape shift.

Method and apparatus for compensating for media shift due to tape guide

Calibration logic separately operates DC motors of a tape drive at a steady state estimated velocity (Omega C) for at least one full revolution without a tape; senses Hall sensor(s) to indicate a full revolution of each motor, measuring the time of the full revolution; determines the actual velocity (Omega A) of each motor employing the measured time; compares Omega C to Omega A to determine a calibration constant (K calib) for each motor; to calibrate the motor velocity of each motor, for determining the velocity for a mounted tape by averaging the tape velocity generated by each motor based on the calibrated motor velocity.

Calibration of tape drive velocity employing DC motor hall sensor

Dynamic tension control for tape transported along a tape path between supply and take-up reels, driven by supply and take-up motors, and having tachometers for determining linear speed of the tape. A controller accelerates the tape toward a target speed, initially operating the motors in static acceleration tension control; and if the linear speed of the tape is within a predetermined range of the target tape speed, operating the motors in composite tension control employing static tension control and delta velocity control.

Combined tension control for tape

An apparatus and method for the controlled dynamic braking of a DC motor in a tape transport device are provided. A PWM state device includes a plurality of state transition paths, each path having an initial state, representative of a tape profile, including a predetermined range of tape velocities, relative amounts of tape on each reel and an initial tape tension, and at least one subsequent state. When a low power event is detected, one of the state transition paths is selected, based upon a current tape profile, and an associated PWM signal is transmitted to the motor. An energy storage device provides power to the PWM state device during the low power event. The PWM signals follow the selected transition path to modulate the current generated by the motion of the motor and thereby create a decelerating force while substantially maintaining the initial tape tension.

Dynamic braking of a tape motor

A method and apparatus for providing linear position (LPOS) estimations. If valid LPOS data may be detected from the tape, then a first method for LPOS estimation is performed using the Hall effect sensors. If valid LPOS data may not be detected from the tape, then an error recovery procedure (ERP) is invoked so that a second method for LPOS estimation is used to provide accurate LPOS information which is synchronized to a validly detected LPOS from tape within about 1 meter prior to the desired data record.

Method and apparatus for providing linear position (LPOS) estimations

Verification system logic operates PWM motor drivers for DC motors of a tape drive, and verifies the on time duty cycle period and offset of the PWM motor drivers; verifies DAC current reference and amplifier sense signals against thresholds; and verifies Hall sensor state sequence of the DC motors during rotation. If the verifications are successful, the logic rotates the DC motors, and, for each motor, verifies the time of acceleration at a desired torque; verifies a computed velocity based on a measured velocity to a reference velocity; and verifies an actual rotation rate to a computed velocity.

Verification of operational capability of a tape drive

Method and apparatus for performing position error signal conditioning of LTO media servo format written-in velocity variation

A method for calibrating a tape transport servo system for a tape drive is disclosed. The tape reel motors are excited when the tape drive is not being controlled by the tape transport servo system. Then, calibration data is collected for the motor torque, motor friction, DAC offsets, and pulse width modulator control signal timing.

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Tucson, AZ, United States of America

John Alexander Koski