Inventor

DUNFIELD JOHN C

US40 patents

⚠️ This page may combine multiple inventors who share the name “DUNFIELD JOHN C”. Patents are grouped by organization below to help distinguish them — per-person disambiguation is on the roadmap.

DUNFIELD JOHN C

SEAGATE TECHNOLOGY

Position detection for a brushless DC motor without Hall effect devices using a mutual inductance detection method

Position detection for a brushless DC motor without hall effect devices using a time differential method

Detection of starting motor position in a brushless DC motor

Detection of starting motor position in a brushless DC motor

Passive magnetic bearings for a spindle motor

Stator isolation for spindle motor

Method for starting and commutating a permanent-magnet direct current motor having a single phase winding

Integrated passive magnetic bearing system and spindle magnet for use in an axial magnet spindle motor

Integrated passive magnetic bearing system and spindle magnet for use in an axial magnet spindle motor

Ironless spindle motor for disc drive

Integrated passive magnetic bearing system and spindle permanent magnet for use in a spindle motor

Passive magnetic bearings for a spindle motor

Floating electrical contact for spindle motor

Disc drive spindle motor with rotor isolation and controlled resistance electrical pathway from disc to ground

Low leakage actuator for high performance

Passive magnetic bearings for a spindle motor

Hydrodynamic spindle motor having distributed windings

Integrated passive magnetic bearing system and spindle permanent magnet for use in a spindle motor

Fluid thermal compensation and containment for hydrodynamic bearings

Method of magnetizing a ring-shaped magnet

Slotless spindle motor for disc drive

Disc drive spindle motor with controlled resistance pathway from disc to ground

Support flange having electrical contacts to provide electrical continuity upon spindle motor mounting to base

High resistivity bearing balls for spindle motor isolation

Wire guide and adhesive retaining ring for disc drive spindle motor

Magnetic crash stop and latch in a disc drive

Space optimization voice coil motor for disc drives

Hydrodynamic bearing including means for monitoring the capacitance between the rotor and stator of a hydrodynamic bearing

Small form factor actuator for improved functionality and linearity

Particle containment and fluid retention with barrier seal in magnetic disc drive

Apparatus for electrically grounding a rotor hub in a disc drive motor

Small form factor actuator for improved functionality and linearity

XEROX CORP

Adaptive print hammer damper

Quiet impact printer

Print tip contact sensor for quiet impact printer

Impact mechanism for quiet impact printer

MICROVISION INC

Frequency tunable resonant scanner

Frequency tunable resonant scanner

Frequency tunable resonant scanner

SEAGATETECHNOLOGY INC

Passive magnetic bearings for a spindle motor