Jianbo He from 6861 Queenswood Way, San Jose, CA 95120, age 56

Active Damping Of Two-Stage Actuator System In A Disc Drive
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US Patent:

6791786, Sep 14, 2004
Filed:

Dec 11, 2000
Appl. No.:

09/734454
Inventors:

JianBo He - Longmont CO
Joseph Cheng-Tsu Liu - Singapore, SG
Kevin Gomez - Singapore, SG
Tao Zhang - Kingston, CA
Assignee:

Seagate Technology LLC - Scotts Valley CA
International Classification:

G11B 5596
US Classification:

360 7805, 360 75, 360 7806
Abstract:

An actuator control system for a two-stage actuator system of a disc drive has a first, or primary, stage actuator consisting of a voice coil motor that positions the head relative to a disc and a microactuator that alters the actuator system without operation of the voice coil motor. A control loop includes a controller responsive to seek commands to operate the voice coil motor, thereby moving the head relative to the disc. An active damping circuit is coupled to the head to operate the microactuator to damp resonance modes of the actuator system.

Efficient Feedforward Compensation For Repeatable Runout In A Disc Drive
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US Patent:

6867943, Mar 15, 2005
Filed:

Jun 26, 2002
Appl. No.:

10/180569
Inventors:

Brent Jay Harmer - Johnstown CO, US
Jianbo J. He - Longmont CO, US
Khalil B. Dizaji - Louisville CO, US
Hai Thanh Ho - Broomfield CO, US
Reed David Hanson - Chaska MN, US
Assignee:

Seagate Technology LLC - Scotts Valley CA
International Classification:

G11B005/596
US Classification:

360 7704
Abstract:

Method and apparatus for more accurate track following. Control circuitry rotates a data storage surface containing thousands of annular tracks. A “measured” subset of the tracks is selected so as to be interspersed with an “unmeasured” subset. The calibration profile is derived based on position error signals each obtained by reading from the measured subset and not from the unmeasured subset. Data from the unmeasured subset of tracks is ignored, in generating and/or updating the profile.

Peak To Peak Detect Method To Protect Seek/Settle Induced Encroachment
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US Patent:

6906886, Jun 14, 2005
Filed:

Sep 8, 2003
Appl. No.:

10/657792
Inventors:

Jianbo He - Longmont CO, US
Gregory Christopher Labbe - Longmont CO, US
Avanindra Annu Gupta - Louisville CO, US
Sandeep Dominic Sequeira - Longmont CO, US
Assignee:

Seagate Technology LLC - Scotts Valley CA
International Classification:

G11B005/58
US Classification:

360 7701
Abstract:

A system and method for improving write integrity of a magnetic storage system. A settling algorithm counter is reset if a position error signal of the write head indicates the head is vibrating with mechanical oscillations outside a predetermined threshold.

Dual Stage Positioning System Using A Shared Voltage Source
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US Patent:

20020057068, May 16, 2002
Filed:

May 15, 2001
Appl. No.:

09/855354
Inventors:

Hai Ho - Westminster CO, US
Margot LaPanse - Superior CO, US
Charles McHenry - Loveland CO, US
Jianbo He - Longmont CO, US
International Classification:

G05B011/01
US Classification:

318/560000
Abstract:

A system for positioning a read/write head having a voice coil suitable for coarse control and a piezoelectric transducer (PZT) suitable for fine control. A voice coil control signal and a PZT control signal are generated from a position-indicative signal, both receiving power via a shared supply having a nominal rectified voltage V. In a preferred method, control signals are both applied to the voice coil and PZT when amplified so that each has a saturation voltage smaller than |V

Jianbo He