Browse Prior Art Database

Combined Piezoelectric/Magnetic Actuator

IP.com Disclosure Number: IPCOM000122894D
Original Publication Date: 1998-Jan-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 2 page(s) / 40K

Publishing Venue

IBM

Related People

Imaino, W: AUTHOR

Abstract

A means for actuation using piezoelectric materials and magnetic circuits that result in large displacements, retain the high bandwidth of piezoelectrics, and require very low holding currents in dc operation is described.

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Combined Piezoelectric/Magnetic Actuator

      A means for actuation using piezoelectric materials and
magnetic circuits that result in large displacements, retain the high
bandwidth of piezoelectrics, and require very low holding currents in
dc operation is described.

      Fig. 1 shows the overall concept.  A piezoelectric material is
used to alter the magnetic circuit to produce flux changes.  The
change in flux causes changes in magnetic forces to produce
displacement of the  actuator.

      Fig. 2 is a simple embodiment of the concept for use as the
focus actuator for an optical storage drive.  The structure, while
the outer piece has a split pole stationary structure and a
piezoelectrically actuated pole piece vertically, flux switches
between the split poles.  This produces a magnetic force that causes
the center bobbin structure to translate vertically.  The amount of
translation is limited by either the bending stiffness of the
supporting structure or the physical dimensions of the magnetic
circuit.