Exabyte Corporation

Steven L Magnusson

Timothy C Hughes

Wolfgang Nichtl-Pecher

New helical recording scanner architectures and transducing methods provide a consistent track pitch for helical tracks despite positional errors in placement of transducing elements (or sets of transducing elements) from their nominal positioning. The new scanners () are rotatable scanners having a vertical direction parallel to an axis of rotation of the scanner. Both first and second transducing elements are mounted on the scanner, and a tape drive () which comprises the scanner also includes a transport system for transporting magnetic tape () proximate the rotatable scanner in a manner so that information is transduced in helical tracks by the transducing elements during revolutions of the scanner. A width of the transducing elements and the nominal positioning of the transducing elements with respect to the vertical direction are selected so that the tracks transduced by the first transducing element and the second transducing element have a desired pitch regardless of an error between the nominal positioning and actual positioning of at least one of the first transducing element and the second transducing element.

Method and apparatus for maintaining consistent track pitch in helical scan recorder

A helical scan tape recorder () comprises a rotatable scanner () upon which is mounted a first set of plural transducing heads (WW) and a second set of transducing heads (WW). A transport system transports magnetic tape () proximate the rotatable scanner in a manner so that information is transduced by at least one of the transducing heads during a revolution of the scanner. The sets of transducing heads are so mounted on the scanner with respect to azimuthal orientation of the transducing heads that all tracks transduced by the transducing heads have a desired width regardless of an error in physical distance separating the sets of transducing heads. In one aspect, the first set of plural transducing heads comprises a first head (W) and a third head (W), and the second set of plural transducing heads comprises a second head (W) and a fourth head (W). The sets of transducing heads are mounted on the scanner so the first head and the third head transduce respective tracks during a first angular phase of the rotation of the scanner, and so that the second head and the fourth head transduce, during a second angular phase of the rotation of the scanner, respective tracks which partially overlap a previously-transduced track. The tracks on the tape alternate according to differing azimuthal orientation.

Alternating-azimuth angle helical track format using grouped same-azimuth angle heads

A helical scan tape drive ( ) has a cartridge compartment ( ) for accommodating a single reel cartridge ( ) of magnetic tape ( ), and a take-up reel ( ) which, with respect to a threading path ( ), is not coplanar with the cartridge compartment. A threading system ( ) grasps an end of the magnetic tape in the cartridge and transports the magnetic tape through the threading path. The threading path is configured such that the magnetic tape is at least partially wrapped around a rotatable scanner ( ) before the end of the magnetic tape is attached to the take-up reel. The rotatable scanner has one or more elements ( ) for transducing information relative to the magnetic tape. The take-up reel is situated at a location either above or below the cartridge compartment for reducing footprint of the drive. In one embodiment, the take-up reel and the compartment are in an at least partially overlapping relationship.

Direct threading helical tape path for single-reel tape cartridge

A scanner ( ) for use in a helical scan magnetic transducing apparatus has a periphery upon which plural read tranducing elements ( ) and plural write transducing elements ( ) are mounted non-symmetrically. The plural write transducing elements are physically situated on the periphery of the scanner in M number of local groups ( ), wherein the plural read transducing elements are physically situated on the periphery of the scanner in N number of local moveable groups ( ), and wherein M<N. Each of the moveable groups has a separate actuator ( ) for adjusting position of the group.

Non-symmetric helical scanner architecture for high track density

A transducing head ( ) for a magnetic tape recorder comprises a first magnetic pole ( ) and a second magnetic pole ( ) positioned to form a gap therebetween. The first magnetic pole ( ) has a first magnetic pole width H along the gap and the second magnetic pole ( ) has a second magnetic pole width H along the gap. The first magnetic pole width H and the second magnetic pole width H are formed to satisfy the relation H <H <3T<H wherein H is a physical tape contact width of the transducing head and 3T is a width of three adjacent recorded tracks traversed by the head.

Transducing head for tape drive

A pack of magnetic recording tape ( ) comprises a splicing tape ( ) which adheres a web of a magnetic tape ( ) to a leader ( ). The leader ( ) attaches to a reel hub ( ) around which the tape is to be wound. The length L of the splicing tape in a direction parallel to an elongate dimension ( ) of the magnetic tape is on the order of N&pgr;D, where D is the diameter of reel hub and N is an integer. In one embodiment, the length L of splicing tape is just slightly less than the circumference of the reel hub. The tape assembly comprising the combination of the magnetic tape, the leader, and the splicing tape greatly reduces the amount of permanent tape deformation, and provides a more efficient tape pack with smaller discontinuities. Consequentially, the stress on the magnetic tape is greatly reduced, which reduces the amount of permanent deformation and the number of magnetic tape layers that are affected by the deformations. This minimizes the area of the magnetic tape that may be rendered unusable. The tape pack ( ) can be utilized in a magnetic tape cassette or cartridge ( ), which can be either a dual reel cartridge or a single reel cartridge.

Magnetic tape splicing for reducing tape pack distortion

A dual-scan master calibration tape is prepared and used for adjusting guide elements of a magnetic tape drive. The dual-scan master calibration tape is generated by transporting the master calibration tape past a rotating drum whereon a write head is mounted and activating the write head only during every other rotation of the drum. In use, the master calibration tape is transported past a read head in a manner whereby, for a track pre-recorded on the master calibration tape, the read head separately follows a first path over the track and a second path over the track. A first path read signal is generated as the read head follows the first path over the track; a second path read signal is generated as the read head follows the second path over the track. Both the first path read signal and the second path read signal are used to determine a calibration indicia for the tape drive.

Preparation and usage of dual-scan master calibration tape for magnetic

A method of determining a vertical (e.g., axial) offset distance between a first and a second transducing element of a helical scan tape drive involves varying a ratio of a rotational velocity of the drum to a linear tape speed of the tape while transducing a magnetic pattern between at least one of the transducing elements and the tape. The pattern transduced is read and used to determine information pertaining to the vertical offset distance. In one mode of the invention, a vertical offset distance between a read transducing element and a write transducing element is determined by using a peak magnitude of a read signal. In a second mode of the invention, the linear tape speed is first set to a value at which tracks recorded by a second write transducing element are rendered unreadable, and a resultant noise signal acquired. Then the linear tape speed is slowly varied through a range of values to obtain a value at which tracks recorded by the second write transducing element are not rendered unreadable, and thereat a non-noise signal acquired. A threshold linear tape speed at which the non-noise signal begins is used to determine the vertical offset distance between the first and second write transducing elements.

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Boulder, CO, United States of America

Steven L Magnusson