Abstract: The magnetic tape cartridge includes a magnetic tape, and a cartridge reel, in which, in the magnetic tape, a minimum winding deviation occurrence load measured after the magnetic tape is rewound around the cartridge reel by applying a tension of 0.20 N in a longitudinal direction of the magnetic tape is 200 N or less.

Abstract: A method according to one embodiment includes computing a radius value of a tape on an outgoing reel during unwinding of the tape from the outgoing reel, adjusting the computed radius with an offset calculated from a direct measurement of velocity from the tape position, and outputting the adjusted computed radius. A method according to another embodiment includes computing a radius value of a tape on an incoming reel during winding while the tape is being wound onto the incoming reel, adjusting the computed radius with an offset calculated from a direct measurement of velocity from the tape position, and outputting the adjusted computed radius.

Abstract: A method according to one embodiment includes selecting an initial radius value (Rfull) for an outgoing reel, where Rfull is the initial radius of a tape on the outgoing reel; unwinding the tape from the outgoing reel; computing a radius value of the tape on the outgoing reel during the unwinding; adjusting the computed radius with an offset calculated from a direct measurement of velocity from the tape position; and outputting the adjusted computed radius. A method according to another embodiment includes selecting an initial radius value (R0) for an incoming reel, where R0 is the initial radius of the incoming reel; winding the tape onto the incoming reel; computing a radius value of the tape on the incoming reel during the winding; adjusting the computed radius with an offset calculated from a direct measurement of velocity from the tape position; and outputting the adjusted computed radius.

Abstract: A rotational torque adjustment apparatus is used to adjust the rotational torque of a rotational member secured to a rotational shaft for integrally rotating with the rotational shaft. The rotational torque adjustment apparatus includes a friction member for contacting with the rotational member to apply a frictional load to the rotational member, a brake member for holding the frictional member thereon, a pressing member for pressing the friction member held on the brake member with a predetermined pressure against the rotational member, and a guide section for holding the brake member for movement thereon. The brake member is moved in a radial direction of the rotational member along the guide section to vary the rotational torque of the rotational member.

Abstract: Methods and systems of controlling transport of film are disclosed. In one embodiment, a method of controlling a supply platter motor in a no-rewind film transport system, comprises receiving take-up platter control signal information from a take-up platter controller, processing the take-up platter control signal information, and controlling the supply platter motor based at least in part on the processed take-up platter control signal information.

Abstract: A stop command detecting unit detects an operation transition from fast forwarding/rewinding modes to a stop mode, a take-up side reel braking unit and a supply side reel braking unit start a braking operation based on the stop command, and a driving motor of the take-up side reel is driven at a specified current value set by a motor current value setting unit for a specified time set by a current adding time setting unit to provide the take-up side reel with rotary torque in the winding direction. Hence, the supply side reel rotates together with the take-up side reel until the supply side reel is stopped, thereby preventing occurrence of a slack on the tape.

Abstract: In general, the invention is directed to techniques for reducing deformation of tape in data tape cartridges during storage to promote dimensional stability and increased tape longevity. The techniques involve controlling the winding tension applied to a tape during a final winding pass prior to unloading a data tape cartridge containing the tape from a drive. Excessive winding tensions can produce strain and compression on a tape pack, causing the tape to deform over time. Applications of reduced winding tension during the final pass provide reduced tape pack tension during periods in which the data tape cartridge is not used.

Abstract: A system for measuring a length of tape available for a record operation has both a tape supply reel which rotates as a tape leaves the supply reel during a tape transfer process, and a tape take-up reel which receives tape from the supply reel, and the tape take-up reel also rotates as it receives the tape during the tape transfer process. There are provided an encoder responsive to movement of the tape, a first angular position transducer to measure an angular position of the tape supply reel, a second angular position transducer to measure an angular position of the tape take-up reel, and a third transducer responsive to the encoder. A Kalman filter, responsive to an angular position measurement by the first angular position transducer, the second angular position transducer, and also the third angular position transducer, calculates the length of tape available for a record operation.

Abstract: The present invention provides two methods, apparatus, and computer instructions for controlling tape movement in a tape drive system. In the first method, the direction of tape movement is determined with respect to a file reel and a machine reel. If the direction of tape movement is toward the file reel, the tape is moved using machine reel control, and if the direction of tape movement is toward the machine reel, the tape is moved using file reel control. In the second method, the size of a file reel, designated as the file radius, and the size of a machine reel, designated as the machine radius, are determined. If the machine radius is smaller than the file radius, tape motion is carried out using machine reel control, and if the file radius is equal to or smaller than the machine radius, tape motion is carried out using file reel control.

Abstract: A method and apparatus for varying track recording speed to maximize host-to-tape data transfer rates is presented. Variable data transfer rates of host systems and networks are accommodated by continually adjusting the tape speed to match the tape drive to the host's actual transfer rate. jThe speed of the tape is adjusted according to both the level of data present in the tape drive data buffer and whether the current mode of the drive is write mode or read mode. In the preferred embodiment, when the tape speed is accelerated or decelerated while writing a number of data track pairs to tape, a predetermined number of dummy track pairs are first written to tape at the current speed. On the next write head phase after the speed is increased or decreased as appropriate while the read heads are over the track, a predetermined number of dummy track pairs followed by more data track pairs are written to the tape at the new speed.

Abstract: A reel-to-reel tape system stops movement of the tape during a power loss situation without overrun by one of the tape reels and without causing undue stress upon the tape itself. If rotational momentum of the supply reel is sensed to be disproportionately larger than the momentum of the take-up reel, supply motor back emf for dynamically braking the supply reel is applied while also driving the take-up reel in the direction of rotation in which it operated when the power source was discontinued. An appropriate amount of tension is maintained on the tape until the tape motion has come to a complete stop. A capacitor large enough to supply the power needed to provide current to the power bridge of the motor drivers is provided. The capacitor is charged upon power up of the drive and is not tapped unless and until the normal supply voltage of the motor drivers is turned off.