Seagate Technology Incorporated

Servo Track Writer Corporation

Other

Minnesota Mining and Manufacturing Company

Dma Systems Corporation

Cambrian Consultants, Inc.

Micropolis Corporation

Data Recording Instrument Company Limited

Dri Holdings Limited

Martyn A Lewis

Elaine Unemori

Walter E Hinds

Kirk P Conrad

David A Sutton

Xinfan Huang

Steven K Penniman

Gajus Michelson

William W Valliant

Carol A Tozzi

Francis P Hammond

The invention related to methods of treating disease related to vasoconstriction that is a major factor in hypertensive vascular diseases and vasodilation, generally comprising administering to an individual an effective amount of a pharmaceutically active relaxin. Relaxin functions to increase both vasodilation and angiogenesis in males as well as females, and is useful in treating a wide variety of diseases relating to vasoconstriction.

Use of relaxin treat diseases related to vasoconstriction

A speed control system is disclosed wherein a brushless DC motor and a magneto resistive encoder are able to rotate a motor at arbitrarily low speeds. The motor is able to rotate at low speeds by having a filtered signal generated by an encoder applied to its inputs. The encoder is coupled to a series of filters which remove DC level and harmonic distortions from the resulting encoder signal. These filtered signals are then applied to the motor to control motor rotation speed.

Economical wide range speed control system

A method and apparatus for increasing the top speed of a brushless DC motor (BLDCM) or a closed loop step motor (CLSM) which are driven by substantially sinusoidal signals on each of its leads. Art additional signal is generated which has a fundamental frequency component at a harmonic of the frequency of the main sine wave signals applied to the motor leads. The additional signal is added to the normally applied signal on each motor lead. The amplitude and phase of the additional signal are chosen to increase the top speed of the motor, or alternatively, to reduce the supply voltage needed for a given speed.

Brushless motor speed control arrangement having derived common mode

A head records a track (e.g. a servo track) in a memory member outside of a clean room without using reference indices. In each of a plurality of cyclical movements (e.g. revolutions), signals (e.g. servo signals) are recorded in the track in an individual number of frames. Thereafter the distance of the unrecorded portion of the track is determined. In the next cyclical movement, the head records signals in an individual number of frames contiguous to the frames previously recorded, in a track distance dependent upon such individual number relative to the number of frames still unrecorded and upon the distance determined for the unrecorded track portion. In a last cyclical movement, the head records a single frame in a particular spatial relationship with the first and last frames. In a specific embodiment, 2.sup.N-K frames may be recorded in the K cyclical movement. Additional signals may thereafter be recorded by the head in tracks in a single cyclical movement. In another embodiment, each individual number of frames continue to be recorded in the first track in each cyclical movement until the frames occupy a distance, within particular limits, dependent upon the unrecorded length of the track and upon the individual number of frames relative to the number of frames still unrecorded. In a further embodiment, sectors and data sectors following the sectors are recorded with signals in progressive cyclical movements in a manner similar to the recording of the sectors in such revolutions in the first embodiment.

Apparatus for, and methods of, recording signals in tracks on a memory

A disk drive system with adaptive positioning employs one or more storage disks for recording data, one or more read and write heads for performing input/output operation on the disks, with at least one of the heads being used as a servo head, a head-positioning mechanism for controlling the movement of the heads, and a digital compensator for predicting the post-seek displacement of the heads due to internal accelerations and to provide a compensating control signal to the head-positioning mechanism. The compensator includes means for approximating an nth order transfer function and learning algorithms for adapting to the dynamic response characteristics of an individual disk drive unit. The positioning of the heads is adapted to minimize post-seek displacements through trial seeks executed at disk startup and continually through background processes performed during normal input/output operations.

Disk drive with adaptive positioning

A head records a track (e.g. a servo track) in a memory member outside of a clean room without using reference indices. In each of a plurality of cyclical movements (e.g. revolutions), signals (e.g. servo signals) are recorded in the track in an individual number of frames. Thereafter th e distance of the unrecorded portion of the track is determined. In the next cyclical movement, the head records signals in an individual number of frames contiguous to the frames previously recorded, in a track distance dependent upon such individual number relative to the number of frames still unrecorded and upon the distance determined for the unrecorded track portion. In a last cyclical movement, the head records a single frame in a particular spatial relationship with the first and last frames. In a specific embodiment, 2.sup.N-K frames may be recorded in the K cyclical movement. Additional signals may thereafter be recorded by the head in tracks in a single cyclical movement. In another embodiment, each individual number of frames continue to be recorded in the first track in each cyclical movement until the frames occupy a distance, within particular limits, dependent upon the unrecorded length of the track and upon the individual number of frames relative to the number of frames still unrecorded. In a further embodiment, sectors and data sectors following the sectors are recorded with signals in progressive cyclical movements in a manner similar to the recording of the sectors in such revolutions in the first embodiment.

A system and method for controlling and analyzing data storage systems, and more particularly, to systems and methods for controlling and analyzing performance and physical attributes of a sealed disk drive unit using an externally accessible but internally integral positioning system. A disk drive having a sealed housing utilizes a reflective planar mirror on the rotary actuator controlling the head drive assembly. A narrow beam directed through a window on the side wall of the housing onto the mirror is reflected off at angle dependent on the actuator position to a beam sensitive detector. A translator system driven by a positioner disposed at a distance from the rotary actuator axis which is substantially greater than the distance between the actuator axis and the head assembly, is used to vary the relationship between the directed and reflected beams. This system incorporates the rotary actuator in a closed loop servo that positions the actuator precisely at different locations relative to the recording medium, so that the data may be written and analyzed at off-track track position increments. The invention further provides, at an early or later manufacturing stage, means for calculating bias torque and friction without the need for prerecorded embedded servo information.

Method and apparatus for controlling and analyzing a data storage system

A linear induction motor system employs a driven reactive element that is oppositely influenced by a pair of spaced apart devices extending along a predetermined path. By altering the relationship between the reactive elements and devices, the net driving force on the driven element is varied so that a desired velocity profile can be established, and stable index positions can be defined. The principle is advantageously used in controlling a series of independent carts in a material conveyor system, in an arrangement which incorporates secondary positional control device along the cart path, and probe means for inhibiting interference between successive carts.

Linear induction motor systems

A method and apparatus are disclosed for providing continuous position information in a position servo system having position information signals 162, 164 coming from encoder 160 and which provide indirect position information over selected ranges, and a reference position information signal 153 coming from transducer 140 and which provides reference position information at discrete intervals. In the preferred embodiment, the distances between selected positions of two position information signals are combined, and in response to position offset information obtained from the reference position signal 153, thereafter used in selecting which of the position information signals 162, 164 will be used for determining position information. The position determination techniques are further employed in positioning the transducer apparatus 140 relative to a rotating storage medium 142 through the use of an externally commutated positioning apparatus, such as motor 100, under control of a processing element 30. A control method is combined with the positioning method and apparatus which includes an initial determination of salient parameters associated with the apparatus (such as the commutation points of the motor 100 with respect to its end stops, and the amplitude of the two signals 162, 164). Positioning of the transducing apparatus 140 is achieved through a plurality of control modes which are responsive to the determined parameters. In addition, the accuracy with which the position of the transducing apparatus 140 is determined varies among the modes with the remaining distance yet to traverse to a desired destination position.

Transducer positioning apparatus with multiple modes of motion

A method and apparatus are disclosed for positioning a transducing apparatus relative to a rotating storage medium through the use of an externally commutated positioning apparatus under control of a processing element. In addition, a control method is disclosed which includes an initial determination of salient parameters associated with the apparatus. Positioning of the transducing apparatus is achieved through a plurality of control modes which are responsive to the determined parameters. In addition, the accuracy with which position of the transducing apparatus is determined varies among the modes with the remaining distance yet to traverse to a desired destination position.

Transducer position control system for disk storage equipment

In a magnetic disc storage system and a magnetic disc therefor, the disc having opposed surfaces, at least one of the surfaces being coated with a magnetic material, the disc being adapted to be mounted on a spindle for rotation relative to a magnetic transducer positioned for recording data on and retrieving data from the disc, a plurality of concentric annular tracks being defined on the surface of the disc, each of the tracks being divided into a plurality of sectors, each sector having associated therewith prerecorded servo data for identification thereof, the improvement wherein the servo data for each sector comprises a unit distance track identification code recorded three times in succession, the code changing between adjacent sectors of adjacent tracks, and a clock shift check code recorded immediately following the last recorded one of the track identification codes, the same clock shift check code being recorded for each sector of every track.

Method and apparatus for recording transducer positioning information

A control system for a stepper motor utilized in positioning a transducer in relationship to a plurality of parallel tracks on a record media. Dual closed loop feedback systems are provided. A current control circuit is provided having a high output impedance and a voltage control circuit is provided having a low output impedance. A switch may select the control sensor when the transducer is making coarse adjustments in position and may select the voltage control sensor when the transducer is making fine adjustments in position. A seamless switchover may be achieved where the voltage control sensor has a time constant which matches the time constant of the stepper motor. Performance is further improved by providing an impedance cancellation circuit which eliminates the internal resistance of the motor in order to quickly damp motionally induced emf of the motor.

Control system for transducer positioning motor

In a disc drive including a disc having a magnetic surface and supported for rotation on a spindle, a spindle motor for driving the spindle, a linear motor having a positioner coil for radially moving a head support structure along the disc surface, and a circuit responsive to an emergency condition for causing the linear motor positioner coil to retract the head support structure, there is disclosed an improvement wherein the spindle motor is a rotating magnet DC motor and the kinetic energy stored in the rotating spindle mass is used to provide the energy required to unload the heads upon the occurrence of an emergency situation. Under emergency conditions, the spindle motor windings are switched directly to the linear motor positioner coil and the spindle motor acts as a generator to supply the head retract energy.

Emergency head retract system for magnetic disc drives

A control system for a brushless direct current motor providing linear closed loop speed control when the motor is operating near its desired speed and providing pulse width modulation closed loop speed control when the motor is not operating near its desired speed. A current sensing feedback loop is provided to drive the transistor linearly controlling the electronic commutation of the motor into pulse width modulation when the current through the motor exceeds a predetermined value. An inductor may be coupled in series with control transistor and positive feedback may be supplied to the current sensor.

Growing community of inventors

Pacific Palisades, CA, United States of America

Martyn A Lewis