Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A circuit for a high-density data recording channel includes a first data detector, a second data detector, one or more multiplexers and a sequence identifier. The first data detector generates a first data detector output, and the second data detector generates a second data detector output. The multiplexers change between a first mode and a second mode to alternately receive the first data detector output and the second data detector output. The sequence identifier receives a data sequence including at least one of a first data sequence, such as VFO data, and a second data sequence, such as random data. The second data sequence includes a greater number of signal levels than the first data sequence. The sequence identifier changes the multiplexers between the first mode and the second mode based on whether the data sequence is the first data sequence or the second data sequence. The data sequence includes a plurality of timing stages.

Abstract: Method and apparatus for writing timing based (servo) tracks on magnetic recording tape using complementary servo writer pairs. A magnetic tape intended to store, for instance, computer data conventionally contains servo tracks in addition to the data tracks. Typically many servo tracks and data tracks are arranged laterally across the width of the tape. The adjacent servo tracks (bands) here are complementary in terms of the orientation of their stripes and are written (recorded) by a complementary arranged servo writer pair. This advantageously reduces the position error signal by a substantial amount, even to nearly zero. In one version the servo writers are straight in configuration and in another version they are curved or chevron shape. These complementary servo writer pairs write adjacent servo bands.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.