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US 5,237,239 AGranted
Piezoelectric actuator
AssigneeNEC Corporation
InventorsYoshiki Inoue, Kaneo Uehara, Atsushi Ochi
Life of this patent
Estimating the term…
Abstract
In a piezoelectric actuator of the type which has a plurality of grooves on the outer side surface of the actuator body, mechanical reliability of the actuator is enhanced by providing grooves also in the respective layers of a material exhibiting electrostrictive effect located over and below the top and the bottom ends of the actuator. Moreover, a further improvement of mechanical strength can be attained by providing additional grooves onto the outer most grooves.
Claims11
A piezoelectric actuator comprising:
- a pillar of piezoelectric material having first and second end surfaces and side surfaces extending between the first and second end surfaces thereof, a first group of internal electrode layers embedded within said pillar, each of said first group of internal electrode layers being spaced apart from and parallel to each other and electrically connected to a first external electrode, a second group of internal electrode layers embedded within said pillar in parallel with and respectively sandwiched between said first group of internal electrode layers and commonly connected to a second external electrode, the first or second group of internal electrode layers including a first outermost internal electrode layer, and a plurality of grooves formed on said side surfaces so as to surround an elongated axis of said pillar, a first groove of said plurality of grooves being located between said first end surface and said first outermost internal electrode layer.
The piezoelectric actuator comprising:
- a plurality of electrostrictive effect layers, each of said electrostrictive effect layers having opposed principal surfaces, a plurality of internal electrode layers respectively sandwiched between said electrostrictive effect layers forming a laminated body of said electrostrictive effect layers and said internal electrode layers, said laminated body having first and second end surfaces and a side surface extending therebetween, two external electrodes alternately connected to said internal electrodes, and a plurality of grooves provided on said side surface of said laminated body such that each of said grooves extends along a direction parallel to said principal surfaces of said electrostrictive effect layers, a first groove of said plurality of grooves nearest to said first end surface being located between said first end surface and a first layer of said internal electrode layers nearest to said first end surface.
Dependencies are inferred from the claim text.