International Business Machines Corporation

Tomoko Taketomi

Nhan Xuan Bui

Kazuhiro Tsuruta

Angeliki Pantazi

Eiji Ogura

Tsuyoshi Miyamura

Kevin Bruce Judd

Randy Clark Inch

Yutaka Oishi

Reed Alan Hancock

Mark Alfred Lantz

Norie Iwasaki

Hirokazu Nakayama

David Lee Swanson

Roger Javier Justo

Keisuke Tanaka

Armando Jesus Argumedo

David Harper

Giovanni Cherubini

Terue Watanabe

Setsuko Masuda

Yuhko Mori

Takamasa Hirata

Tsutomu Sawa

A tape drive that can select one or more wraps from any available wraps on a tape medium for writing temporary data upon detecting a flush condition. The one or more wraps selected for writing temporary data can be selected from wraps otherwise reserved for normal writing operations. Selection of the one or more wraps for temporary writing may be based on multiple considerations, including proximity to the wrap of current data writing operations and tape medium degradation. The one or more wraps selected for writing temporary data may be selected with or without regard of their assigned read/write direction. Assigning wraps based on proximity and/or degradation can lead to certain operational advantages including reducing tape write head movement in the transverse direction and spreading tape medium wear more evenly across the surface of the tape medium.

Tape drive with intelligent selection of wrap / track for temporarily storing flushed data

In one general embodiment, a method includes calculating a differential position value based on readback signals from at least two servo readers of a magnetic head reading servo tracks of a magnetic recording tape. The differential position value is compared to a previously-calculated differential position value. An action is performed in response to determining that the difference between the differential position value and the previously-calculated differential position value is in a predefined range. In another general embodiment, an apparatus includes a magnetic head having at least two servo readers, and a controller in communication with the servo readers. The controller is configured to detect a sudden change in a width of a magnetic recording tape based on a differential position value derived from relatively more current servo readback data and a second differential position value derived from relatively older servo readback data.

Tape damage detection

A method and system for a controlling a head element of a tape drive is disclosed. Y-position values based on servo bands are identified. Control adjustments for the head element are determined based on the Y-position values and the direction of the current wrap.

Safe head positioning based on y-position values in tape drive

Embodiments of the present invention provide a tape transport control system with enhanced regulation of tape tension and velocity over the entire length of the tape. The tape transport control system comprises of circuitry adapted to output and circuitry adapted to receive one or more signals representing a tape velocity, at least one radius of either the first tape reel or the second tape reel, and a tape tension, and based on the received signals, generate at least one control signal to control at least one of the first reel motor or the second reel motor so as to reduce a tension disturbance at a minimum, one frequency corresponding to a time-varying reel-rotation frequency, based on controller parameters that depend on the tape velocity and on the at least one radius of either the first tape reel or the second tape reel.

Tape transport control with suppression of time-varying tension disturbances

In one general embodiment, a method includes calculating a differential position value based on readback signals from at least two servo readers of a magnetic head reading servo tracks of a magnetic recording tape. The differential position value is compared to a previously-calculated differential position value. An action is performed in response to determining that the difference between the differential position value and the previously-calculated differential position value is in a predefined range. The differential position value is an average of differential position values for a set of samples, wherein the previously-calculated differential position value is an average of previously-calculated differential position values for a set of previously-obtained samples. In another general embodiment, an apparatus includes a magnetic head having servo readers and a controller in communication with the servo readers. The controller is configured to detect a sudden change in a width of a magnetic recording tape.

A magnetic tape head module read element array includes servo readers and read elements configured in accordance with a tape standard. Each read element includes a plurality of read sensors. A microprocessor receives the generation of the tape technology standard and identifies, based on the generation, a combination of read sensors in each read element. Data signals from each read sensor in each combination are buffered. The microprocessor performs error detection and error correction operations on the buffered signal data for each combination of read sensors to generate verified track data in accordance with the generation of tape.

Backward compatibility tape read head

A method and system for adjusting a servo head in a tape drive is disclosed. Position information for the servo head can be obtained and used to determine if an adjustment of one of the servo heads is necessary. By comparing the position of the tape against two servo heads, erroneous adjustments to the servo head can be obviated.

Dynamic head offset selection for tape drive

Some embodiments of the present invention logically eliminate an end region of a user-data area of a magnetic storage tape during formatting (or re-formatting) of the tape, if the position error signal (PES) variance corresponding to the end region exceeds a threshold. An adjacent region, having a PES variance less than the threshold is designated as a new end region, thereby shortening the user-data area of the tape and extending its usable life.

Extending usable life of magnetic storage media

For avoiding debris accumulation on a tape drive, a processor records a position error signal (PES) value and cumulative head turnaround count for each region of a plurality of regions of a magnetic tape. The processor further selects a first region in which to reverse travel of the magnetic tape relative to a tape head. In response to determining one of the PES value for the first region does not exceed a PES threshold and the cumulative head turnaround count for the first region does not exceed a count threshold, the processor reverses travel of the magnetic tape at the first region. In response to determining the PES value for the first region exceeds the PES threshold and the cumulative head turnaround count for the first region exceeds the count threshold, the processor selects a second region at which to reverse travel of the magnetic tape.

Avoiding debris accumulation on tape drive

In one embodiment, a computer-implemented method includes creating a spike in a servo channel from a predetermined start position to an end position, and storing servo data including at least a portion thereof generated during the spike. The spike has a predetermined amplitude. In another embodiment, a computer program product includes a computer readable storage medium having program instructions embodied therewith. The program instructions are executable by a controller to perform the foregoing method.

Generating defect signals in time based servo tape storage systems

A computer program product for positioning an actuator, 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. The program instructions are executable by a processing circuit to cause the processing circuit to perform a method that includes generating or receiving, by the processing circuit, a first value representative of a lateral position of a tape, and using, by the processing circuit, the first value to adjust a position of a coarse actuator for moving a magnetic head in response to determining that the first value is in a first range relative to a first threshold. An integrator value is used by the processing circuit to adjust the position of the coarse actuator in response to determining that the first value is in a second range relative to the first threshold.

Growing community of inventors

Yamato, Japan

Tomoko Taketomi