Quantum Corporation

Certance LLC

Jerry Hodges

Turguy Goker

Ming-Chih Weng

Jaewook Lee

Patrick McCormack

James P Peng

Umang Mehta

Kempton William Redhead

Harold O Ellison

Mark Decot

A method for inhibiting cycle slip in a tape drive having at least three channels that each utilizes a corresponding numerically controlled oscillator includes establishing a reference clock that is based on an output of the numerically controlled oscillators for at least two of the channels, comparing the output of the numerically controlled oscillator for one of the three channels with the reference clock to determine a first channel phase delta value for the one channel, and generating an error signal for the one channel if the channel phase delta value exceeds a threshold phase delta value for the one channel. The method may also include applying an inhibition loop filter to the error signal for the one channel if the first channel phase delta value exceeds the threshold phase delta value, adjusting a gain of the inhibition loop filter based at least partially upon one of the first channel phase delta value and the threshold phase delta value, and/or feeding back the error signal to the numerically controlled oscillator of the one channel.

System and method for detecting and inhibiting cycle slip for multi-channel media drive

In one embodiment, an interpolator-based timing recovery system improves accuracy by calculating additional sampled signals of a digital signal and generating an interpolation based on the additional sampled signals and the digital signal, while employing a parallel architecture to maintain system clock frequency and a pipeline architecture to minimize sampled data memory requirement.

Waveform interpolator architecture for accurate timing recovery based on up-sampling technique

The present invention, in particular embodiments, is directed to methods, apparatuses and systems that facilitate recording of servo signals on a recording medium such as magnetic tape with high accuracy. Variation of inter-frame and intra-frame placement is substantially reduced by writing successive frames or sub-frames based on a detection of a previously-written frame or sub-frame by a read element. Appropriate placement of the read element in relation to servo write elements, on a multi-gap servo write head, ensures the correct placement of subsequent frames on the recording medium.

Servo writing and decoding position error signal for linear tape drives

An example embodiment provides for an apparatus and method, for use in a tape drive system, that supplies tape azimuth error information transduced from servo read elements that are located on differing bumps of a magnetic read/write head. Non-azimuth error information is also transduced from servo read elements located on a read bump. The azimuth error and non-azimuth are utilized to correctly place the magnetic head at a currently selected track of the tape for which data is being written. In one implementation, the servo read elements utilized for transducing the azimuth information are substantially aligned with each other relative to a tape path and disposed on separate bumps. In another implementation, the servo read elements utilized for transducing the azimuth information are not substantially aligned with each other and are disposed diagonally on opposite bumps.

Azimuth compensation using combination bump pes detection

A system and method for damping the motion of the head of a tape drive is disclosed. The method includes measuring the position of the head over time with a position sensor; damping the motion of the head based on the measured position of the head over time; and tuning the damping by varying a parameter of the position sensor.

System and method for tape drive control

A sensor for measuring the position of the head of a tape drive is disclosed. The sensor includes a light emitter movably connected to the head; a light sensor movably connected to the head and rigidly connected to the light emitter and located to receive a beam of light from said light emitter; and, a light interrupter rigidly connected to the head and located for interrupting the light beam.

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Riverside, CA, United States of America

Jerry Hodges