Patents by Inventor David Drouin
David Drouin has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
-
Patent number: 8606410Abstract: The resonance frequency of a forced torsionally oscillating mirror MEMS device can be controlled in the presence of perturbations by means of a closed loop feedback device and method of using it. The method is implemented through a simple algorithm, implemented in either software or hardware, that maintains the condition of resonance, or another selected frequency, by recursively determining that the center of the driving voltage pulse is positioned at a point on the measured positional waveform of the oscillating system.Type: GrantFiled: June 29, 2010Date of Patent: December 10, 2013Assignee: Headway Technologies, Inc.Inventors: David Drouin, David Hu, Sung Chung
-
Publication number: 20120085587Abstract: A modular wind turbine device mountable in a plurality of locations along the exterior of a vehicle. The device comprises a low profile air inlet, a rotatable turbine that utilizes incoming air flow for motive power, and an alternator device for transforming the rotation of the turbine into usable electric power. The air inlet is a raised air scoop that protrudes from the external surface of the vehicle, similar to forced air induction inlets or brake cooling inlets on current vehicles. The inlet is shrouded with a mesh screen to prevent discrete objects from entering or interfering with the turbine device. The turbine is an elongated cylinder with protruding fins that utilize the pressure of the incoming air flow to spin about its central axis. A side-mounted alternator provides a core that spins within a stator to produce an electric current. The electric current is fed to a power management system for controlling and powering a battery pack.Type: ApplicationFiled: April 12, 2011Publication date: April 12, 2012Inventor: David Drouin
-
Publication number: 20110320046Abstract: The resonance frequency of a forced torsionally oscillating mirror MEMS device can be controlled in the presence of perturbations by means of a closed loop feedback device and method of using it. The method is implemented through a simple algorithm, implemented in either software or hardware, that maintains the condition of resonance, or another selected frequency, by recursively determining that the center of the driving voltage pulse is positioned at a point on the measured positional waveform of the oscillating system.Type: ApplicationFiled: June 29, 2010Publication date: December 29, 2011Inventors: David Drouin, David Hu, Sung Chung
-
Publication number: 20100238588Abstract: A magnetic hard disk drive includes a method for eliminating that portion of track following error by a read/write transducer that is caused by repeatable runout of the disk tracks. The repeatable runout is eliminated by application of an iterative algorithm that calculates feed-forward correction terms based on gain coefficients iteratively calculated from the amplitude and phase portions of a Bode plot characterizing the system. The corrective coefficients can be inserted into the hard disk drive at a summing junction that redefines the centerline of the track, or at a summing junction that causes the actuator to follow the repeatable runout and make non-repeatable runout corrections relative thereto.Type: ApplicationFiled: March 17, 2009Publication date: September 23, 2010Inventors: David Drouin, Billy Wahng
-
Patent number: 7787210Abstract: A magnetic hard disk drive includes a method for eliminating that portion of track following error by a read/write transducer that is caused by repeatable runout of the disk tracks. The repeatable runout is eliminated by application of an iterative algorithm that calculates feed-forward correction terms based on gain coefficients iteratively calculated from the amplitude and phase portions of a Bode plot characterizing the system. The corrective coefficients can be inserted into the hard disk drive at a summing junction that redefines the centerline of the track, or at a summing junction that causes the actuator to follow the repeatable runout and make non-repeatable runout corrections relative thereto.Type: GrantFiled: March 17, 2009Date of Patent: August 31, 2010Assignee: Headway Technologies, Inc.Inventors: David Drouin, Billy Wahng
-
Patent number: 6369970Abstract: A method of writing data to multiple disks on a servo track writing machine comprises the steps of providing a cylindrical disk stacking tool comprising a base and a spindle, loading a first disk onto the spindle in alignment with the base, loading a second disk onto said spindle in alignment with the first disk, placing the loaded disk stacking tool on the servo track writing machine, and simultaneously writing data to the disks with the servo track writing machine. As many disks as desired may be so written to. The disk stacking tool further includes a clamp for locking the disks in place.Type: GrantFiled: May 28, 1999Date of Patent: April 9, 2002Assignee: Castlewood Systems, Inc.Inventors: Howard Steinhoff, David Drouin, Frank Morris
-
Patent number: 6353510Abstract: A system having a storage device including read/write heads for repositioning the read/write heads from a parking location to a position adjacent a surface of a magnetic disk, the storage device includes a spindle motor coupled to the magnetic disk, for accelerating the magnetic disk to at least a first number of revolutions per time period while the read/write heads are positioned at the parking location, and a solenoid control coupled to the read/write heads and to the spindle motor, for biasing the read/write heads towards the position adjacent the surface of the magnetic disk after the magnetic disk reaches the first number of revolutions per time period, wherein the spindle motor maintains a rotation of the magnetic disk at less than a second number of revolutions per time period before the read/write heads are positioned adjacent the surface of the magnetic disk, and wherein the spindle motor rotates the magnetic disk at a third number of revolutions per time period after the read/write heads are positiType: GrantFiled: April 10, 2001Date of Patent: March 5, 2002Assignee: Castlewood Systems, Inc.Inventor: David Drouin
-
Publication number: 20010043425Abstract: A system having a storage device including read/write heads for repositioning the read/write heads from a parking location to a position adjacent a surface of a magnetic disk, the storage device includes a spindle motor coupled to the magnetic disk, for accelerating the magnetic disk to at least a first number of revolutions per time period while the read/write heads are positioned at the parking location, and a solenoid control coupled to the read/write heads and to the spindle motor, for biasing the read/write heads towards the position adjacent the surface of the magnetic disk after the magnetic disk reaches the first number of revolutions per time period, wherein the spindle motor maintains a rotation of the magnetic disk at less than a second number of revolutions per time period before the read/write heads are positioned adjacent the surface of the magnetic disk, and wherein the spindle motor rotates the magnetic disk at a third number of revolutions per time period after the read/write heads are positiType: ApplicationFiled: April 10, 2001Publication date: November 22, 2001Inventor: David Drouin
-
Publication number: 20010019463Abstract: A method for repositioning a read/write head from a parking location to a position adjacent a surface of a magnetic disk, the read/write head disposed on an actuator arm having a voice coil motor, includes the receiving the read/write head load signal, applying a first current pulse to the voice coil motor in response to the read/write head load signal, the first current pulse having a first amplitude and a first duration, determining a back electro-motive force in the voice coil motor, determining a read/write head velocity in response to the back electromotive force, determining the difference between the read/write head velocity and a desired read/write head velocity, using the difference between the read/write head velocity and the desired read/write head velocity to determine a second duration for a second current pulse, and applying the second current pulse to the voice coil motor.Type: ApplicationFiled: December 29, 2000Publication date: September 6, 2001Applicant: Castlewood Systems, Inc.Inventor: David Drouin
-
Publication number: 20010012171Abstract: A method for positioning a magneto-resistive head onto an head load/unload ramp of a storage unit, the magneto-resistive head disposed upon an actuator arm, the actuator arm also having a voice coil, includes the steps of detecting a reset signal, generating a back electro-motive force voltage with a spindle motor in response to the reset signal, generating a drive voltage in response to the back electro-motive force voltage, using a switching circuit to provide the drive voltage to the voice coil in a first polarity for a first period of time, and thereafter, using the switching circuit to provide the drive voltage to the voice coil in a second polarity.Type: ApplicationFiled: November 30, 2000Publication date: August 9, 2001Applicant: Castlewood Systems, Inc.Inventors: Li-Hsin Lu, Stephen R. Jackson, David Drouin
-
Patent number: 6226142Abstract: A technique for formatting a magnetic disk for a removable magnetic cartridge includes the steps of providing the magnetic disk having a top surface and a bottom surface, writing a first servo track onto the top surface, the first servo track having a portion including a first gray code, a first position burst, and a second position burst, writing a second servo track onto the top surface adjacent to the first servo track, the second servo track having a portion including a second gray code, the second position burst, and a third position burst, and writing a third servo track onto the top surface adjacent to the second servo track, the third servo track having a portion including the second gray code, the third position burst and a fourth position burst, wherein a first data track comprises the first servo track, the second servo track and the third servo track.Type: GrantFiled: May 11, 1998Date of Patent: May 1, 2001Assignee: Castlewood Systems, Inc.Inventors: David Drouin, Vien N Nguyen, Stephen R. Jackson
-
Patent number: 6191904Abstract: A technique for reading data from a magnetic disk includes the steps of providing the magnetic disk including a cylinder having a plurality servo sectors, a plurality of data sectors, and a zone data table, the plurality of servo sectors including a first servo sector, a second servo sector, a third servo sector, a fourth servo sector, and a fifth servo sector, the zone data table including at least a nominal timing latency between the fourth servo sector and a data sector from the plurality of servo sectors, reading the first servo sector, the second servo sector, the third servo sector, and the fourth servo sector from the magnetic disk, determining a first timing deviation for the first servo sector between the first servo sector and the second servo sector, determining a second timing deviation for the second servo sector between the second servo sector and the third servo sector, predicting a predicted third timing deviation for the fourth servo sector between the fourth servo sector and the fifth servoType: GrantFiled: November 14, 1997Date of Patent: February 20, 2001Assignee: Castlewood Systems, Inc.Inventors: Vien N. Nguyen, David Drouin
-
Patent number: 6104568Abstract: A technique for determining a position of a read/write head relative to a magnetic disk includes the steps of providing the magnetic disk having a plurality of odd servo sectors and a plurality of even servo sectors, reading a first gray code pattern in an odd servo sector from the plurality of odd servo sectors on the magnetic disk, reading a second gray code pattern in an even servo sector from the plurality of even servo sectors on the magnetic disk, the even servo sector adjacent to the odd servo sector on the magnetic disk and determining the position of the read/write head only in response to the first gray code pattern and the second gray code pattern.Type: GrantFiled: November 14, 1997Date of Patent: August 15, 2000Assignee: Castlewod Systems, Inc.Inventors: David Drouin, Vien N. Nguyen, Stephen R. Jackson
-
Patent number: 6081400Abstract: A technique for method for positioning a magneto resistive head located upon an actuator arm onto a loading ramp of a storage unit. The technique includes the steps of operating a removable magnetic disk at a first number of revolutions per second, the magnetic disk having an outer diameter, positioning the magneto resistive head adjacent to the removable magnetic disk, reading data from the removable magnetic disk, detecting a reset signal, producing a back electro-motive force in response to the reset signal, biasing the magneto resistive head towards the outer diameter of the removable magnetic disk in response to the reset signal and to the back electro-motive force, reducing a number of revolutions per second for the removable magnetic disk from the first number to a second number of revolutions per second, the first number greater than the second number; thereafter using an energy storage unit to bias the magneto resistive head onto the loading ramp, in response to the reset signal.Type: GrantFiled: November 14, 1997Date of Patent: June 27, 2000Assignee: Castlewood Systems, Inc.Inventors: Li-Hsin Lu, Stephen R. Jackson, David Drouin
-
Patent number: 5886846Abstract: A method for applying an optimal seeking technique to a disk file with excessive repeatable runout includes a method of modifying a control signal for a rotary actuator arm of a disk drive. The control signal is modified during track seeking by adding a runout state that is calculated each time a servo sector of a target data track on a surface of a disk is sampled by read/write heads carried by the actuator arm. A calibration algorithm can be used during track following to determine runout magnitude and runout phase at various preselected calibration tracks on the surface of the disk. A seeking algorithm can be implemented to compensate for the relative runout magnitude and phase variations between present and target tracks.Type: GrantFiled: May 31, 1996Date of Patent: March 23, 1999Assignee: Syquest Technology, Inc.Inventors: Ich Pham, David Drouin, Evelyn Howard