Dan J Hunter, 79213 Deer Trail Cir, Boulder, CO 80302

4811132, Mar 7, 1989

Sep 26, 1986

6/912935

Dan A. Hunter - Lafayette CO
Lawrence F. Opperman - Littleton CO
George Gooras - Longmont CO

G11B 1548
B65H 5938

360 743

An early end of tape sensing subsystem for a data processing system, including a host computer, a cache buffer, and a magnetic tape drive subsystem utilizes outputs dependent upon the movement of a capstan wheel, swing arm, and file reel of the magnetic tape drive subsystem, determining the net movement of tape therein in order to measure the circumference of the file reel plus tape thereon. Whenever a series of valid readings from a conventional sensor are obtained indicating that the circumference of the file reel plus tape is approaching that of the circumference of the file reel itself (i. e. , no tape on the file reel), a signal is sent to the microprocessor controlling the cache buffer, said signal indicating that the end of the tape is approaching.

5559648, Sep 24, 1996

Aug 13, 1993

8/106264

Dan A. Hunter - Boulder CO
Michael R. Utenick - Niwot CO
James H. Morehouse - Jamestown CO
Nelson Chenkin - Ft. Collins CO

Integral Peripherals, Inc. - Boulder CO

G11B 5596

360 75

A method for optimizing the storage capacity of miniature disk drives without affecting reliability or yields of the disk drives uses an iterative seek process to define track zero. Initially, a physical reference point is defined and a transducer is moved in coarse steps from the physical reference point until interference with a stationery loading ramp or other mechanical component, hereinafter, "ramp," is detected. Upon detection of interference, the transducer is moved one coarse step away from the ramp and then the transducer is moved in fine steps towards the ramp until interference is again detected. Upon detection of interference, the transducer is moved away from the ramp a predetermined distance. After the transducer is moved the predetermined distance, a check is made for interference. If interference is detected, the transducer is moved in fine step towards the center of the disk until interference is no longer detected.

6097564, Aug 1, 2000

Jun 5, 1996

8/658772

Dan A. Hunter - Boulder CO

Mobile Storage Technology Inc. - Boulder CO

G11B 5596

360 7804

A velocity-controlled actuator system and method are usable in low velocity, high load situations such as those encountered in dynamic head loading, and in normal situations. The velocity-controlled actuator system utilizes a self-tuning estimator that is calibrated during operation of said disk drive. Consequently, parameters, characteristics, and any other features of the disk drive that affect operation of the actuator system are compensated for in real time by the calibration process. The velocity-controlled actuator system dynamically adjusts the actuator resistance utilized in the reconstruction of the back EMF voltage by utilizing a self-tuning estimate of the actuator resistance that compensates for any changes in the actuator resistance over time.

5969899, Oct 19, 1999

Apr 2, 1997

8/832029

Michael R. Utenick - Niwot CO
Dan A. Hunter - Boulder CO
James M. Jones - Boulder CO
Thomas L. Andrews - Boulder CO

Mobile Storage Technology, Inc. - Boulder CO
Samsung Electronics Co., Ltd. - Seoul

G11B 5596

360 7804

An enhanced method and system for unloading magnetic heads are disclosed. The system limits the maximum and minimum speed of the actuator while unloading the heads during a power failure. A BEMF control circuit monitors the velocity of the actuator using the BEMF of the actuator as a gauge of the velocity. The BEMF control circuit uses a sense resistor to remove the inherent resistive component of the actuator from its BEMF measurement. If the velocity of the actuator increases above a safe level the BEMF control circuit decreases actuator current to prevent further acceleration. If the velocity of the actuator decreases below a safe level the BEMF control circuit increases the actuator current to accelerate the actuator to a safe level.

5949608, Sep 7, 1999

Jun 5, 1996

8/659204

Dan A. Hunter - Boulder CO

Mobile Storage Technology Inc. - Boulder CO

G11B 5596

360 7809

A velocity-controlled actuator system and method are usable in low velocity, high load situations such as those encountered in dynamic head loading, and in normal situations. The velocity-controlled actuator system utilizes a self-tuning estimator that is calibrated during operation of said disk drive. Consequently, parameters, characteristics, and any other features of the disk drive that affect operation of the actuator system are compensated for in real time by the calibration process. The velocity-controlled actuator system dynamically adjusts the actuator resistance utilized in the reconstruction of the back EMF voltage by utilizing a self-tuning estimate of the actuator resistance that compensates for any changes in the actuator resistance over time.