Inventor · disambiguated record
John C. Dunfield
Also filed as: DUNFIELD JOHN · DUNFIELD JOHN C · DUNFIELD JOHN C G · DUNFIELD JOHN CHARLES
46 granted patents·2,123 citations·filing 1990–2000
99Inventor score
Top patents by PatentIndex Score
46 records- 0198US5254914APosition detection for a brushless DC motor without Hall effect devices using a mutual inductance detection methodSEAGATE TECHNOLOGY·Filed 1990·Granted Oct 19, 1993·184 cites·28 claims
- 0298US5028852APosition detection for a brushless DC motor without hall effect devices using a time differential methodSEAGATE TECHNOLOGY·Filed 1990·Granted Jul 2, 1991·158 cites·22 claims
- 0397US5598048AIntegrated passive magnetic bearing system and spindle magnet for use in an axial magnet spindle motorSEAGATE TECHNOLOGY·Filed 1994·Granted Jan 28, 1997·73 cites·16 claims
- 0496US5541460APassive magnetic bearings for a spindle motorSEAGATE TECHNOLOGY·Filed 1994·Granted Jul 30, 1996·60 cites·8 claims
- 0595US5694268ASpindle motor having overmolded statorSEAGATE TECHNOLOGY·Filed 1995·Granted Dec 2, 1997·103 cites·31 claims
- 0695US5569990ADetection of starting motor position in a brushless DC motorSEAGATE TECHNOLOGY·Filed 1995·Granted Oct 29, 1996·104 cites·46 claims
- 0793US5841252ADetection of starting motor position in a brushless DC motorSEAGATE TECHNOLOGY·Filed 1995·Granted Nov 24, 1998·89 cites·14 claims
- 0893US5619083APassive magnetic bearings for a spindle motorSEAGATE TECHNOLOGY·Filed 1995·Granted Apr 8, 1997·62 cites·18 claims
- 0993US5587617AIntegrated passive magnetic bearing system and spindle magnet for use in an axial magnet spindle motorSEAGATE TECHNOLOGY·Filed 1995·Granted Dec 24, 1996·75 cites·18 claims
- 1092US6538836B1Microactuator for fine positioning in a disc driveSEAGATE TECHNOLOGY LLC·Filed 1995·Granted Mar 25, 2003·75 cites·29 claims
- 1192US5561335AIntegrated passive magnetic bearing system and spindle permanent magnet for use in a spindle motorSEAGATE TECHNOLOGY·Filed 1994·Granted Oct 1, 1996·49 cites·4 claims
- 1291US6335850B1Microactuator for fine positioning in a disc driveSEAGATE TECHNOLOGY·Filed 2000·Granted Jan 1, 2002·30 cites·4 claims
- 1391US5579188AIronless spindle motor for disc driveSEAGATE TECHNOLOGY·Filed 1995·Granted Nov 26, 1996·79 cites·24 claims
- 1491US5454724AFloating electrical contact for spindle motorSEAGATE TECHNOLOGY·Filed 1994·Granted Oct 3, 1995·55 cites·57 claims
- 1589US5619389AStator isolation for spindle motorSEAGATE TECHNOLOGY·Filed 1995·Granted Apr 8, 1997·56 cites·20 claims
- 1688US5729404ADisc drive spindle motor with rotor isolation and controlled resistance electrical pathway from disc to groundSEAGATE TECHNOLOGY·Filed 1996·Granted Mar 17, 1998·46 cites·41 claims
- 1787US5598071AMethod for starting and commutating a permanent-magnet direct current motor having a single phase windingSEAGATE TECHNOLOGY·Filed 1995·Granted Jan 28, 1997·71 cites·4 claims
- 1886US5956204AMagnetic disc drive having magnetic particle trap for hydrodynamic bearingSEAGATE TECHNOLOGY·Filed 1995·Granted Sep 21, 1999·46 cites·12 claims
- 1985US5610463APassive magnetic bearings for a spindle motorSEAGATE TECHNOLOGY·Filed 1995·Granted Mar 11, 1997·29 cites·10 claims
- 2084US5581424AMagnetic crash stop and latch in a disc driveSEAGATE TECHNOLOGY·Filed 1994·Granted Dec 3, 1996·38 cites·17 claims
- 2183US5633568AMethod and apparatus for dynamic low voltage spindle motor operationSEAGATE TECHNOLOGY·Filed 1995·Granted May 27, 1997·41 cites·11 claims
- 2282US5844748ADisc drive spindle motor with controlled resistance pathway from disc to groundSEAGATE TECHNOLOGY·Filed 1996·Granted Dec 1, 1998·32 cites·25 claims
- 2382US5545937AIntegrated passive magnetic bearing system and spindle permanent magnet for use in a spindle motorSEAGATE TECHNOLOGY·Filed 1995·Granted Aug 13, 1996·31 cites·32 claims
- 2481US5548458ASupport flange having electrical contacts to provide electrical continuity upon spindle motor mounting to baseSEAGATE TECHNOLOGY·Filed 1994·Granted Aug 20, 1996·41 cites·1 claims
- 2581US5485331AHigh resistivity bearing balls for spindle motor isolationSEAGATE TECHNOLOGY·Filed 1993·Granted Jan 16, 1996·30 cites·27 claims
- 2680US5578882APassive magnetic bearings for a spindle motorSEAGATETECHNOLOGY INC·Filed 1995·Granted Nov 26, 1996·26 cites·11 claims
- 2779US5949613ADisk drive spindle motor assembly with stator having a resilient covering with a routing means, an attaching means and a connecting means to operatively connect stator to a baseSEAGATE TECHNOLOGY·Filed 1996·Granted Sep 7, 1999·52 cites·1 claims
- 2878US5524985AFluid thermal compensation and containment for hydrodynamic bearingsSEAGATE TECHNOLOGY·Filed 1995·Granted Jun 11, 1996·32 cites·21 claims
- 2977US5815345ASupport flange having electrical contacts to provide electrical continuity upon spindle motor mounting to baseSEAGATE TECHNOLOGY·Filed 1996·Granted Sep 29, 1998·26 cites·40 claims
- 3077US5698911ALow leakage actuator for high performanceSEAGATE TECHNOLOGY·Filed 1995·Granted Dec 16, 1997·30 cites·13 claims
- 3172US5850318ASlotless spindle motor for disc driveSEAGATE TECHNOLOGY·Filed 1996·Granted Dec 15, 1998·38 cites·18 claims
- 3271US6029978AGrounding and conductivity improvement for ferrofluid sealsSEAGATE TECHNOLOGY·Filed 1997·Granted Feb 29, 2000·22 cites·3 claims
- 3370US5473484AApparatus for electrically grounding a rotor hub in a disc drive motorSEAGATE TECHNOLOGY·Filed 1994·Granted Dec 5, 1995·18 cites·13 claims
- 3466US5808839ADisc drive cartridge including magnetic bearingsSEAGATE TECHNOLOGY·Filed 1996·Granted Sep 15, 1998·19 cites·31 claims
- 3564US5481144AWire guide and adhesive retaining ring for disc drive spindle motorSEAGATE TECHNOLOGY·Filed 1994·Granted Jan 2, 1996·23 cites·15 claims
- 3663US6080352AMethod of magnetizing a ring-shaped magnetSEAGATE TECHNOLOGY·Filed 1997·Granted Jun 27, 2000·26 cites·10 claims
- 3761US5938343AOil filling seal for hydrodynamic motor utilizing a movable sealing elementSEAGATE TECHNOLOGY·Filed 1997·Granted Aug 17, 1999·18 cites·8 claims
- 3860US5774974ARetaining ring for disc drive spindle motorSEAGATE TECHNOLOGY·Filed 1995·Granted Jul 7, 1998·20 cites·7 claims
- 3960US5675230AMethod and apparatus for dynamic low voltage spindle motor operationSEAGATE TECHNOLOGY·Filed 1996·Granted Oct 7, 1997·15 cites·13 claims
- 4058US5600511AParticle containment and fluid retention with barrier seal in magnetic disc driveSEAGATE TECHNOLOGY·Filed 1995·Granted Feb 4, 1997·13 cites·20 claims
- 4157US5590003AHydrodynamic spindle motor having distributed windingsSEAGATE TECHNOLOGY·Filed 1995·Granted Dec 31, 1996·21 cites·15 claims
- 4253US5260618ASpace optimization voice coil motor for disc drivesSEAGATE TECHNOLOGY·Filed 1991·Granted Nov 9, 1993·18 cites·6 claims
- 4352US5459362ASmall form factor actuator for improved functionality and linearitySEAGATE TECHNOLOGY·Filed 1994·Granted Oct 17, 1995·17 cites·22 claims
- 4451US5659215ASmall form factor actuator for improved functionality and linearitySEAGATE TECHNOLOGY·Filed 1995·Granted Aug 19, 1997·17 cites·11 claims
- 4540US5936410AHydrodynamic bearing including means for monitoring the capacitance between the rotor and stator of a hydrodynamic bearingSEAGATE TECHNOLOGY·Filed 1997·Granted Aug 10, 1999·9 cites·9 claims
- 4636US5907455ADistributed spindle motor integrated with discSEAGATE TECHNOLOGY·Filed 1996·Granted May 25, 1999·6 cites·27 claims
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Identity basis: PatentsView inventor disambiguation (2025Q4-odp release). How scoring works →