Laminate-type displacement element

Claim 2

A laminate-type displacement element comprising: a plurality of thin plates having opposing surfaces made of an electromechanical conversion material laminated with internal electrodes alternately covering portions of said opposing surface of said plates, said plurality of plates stacked to form a laminate having opposing sides; a pair of external electrodes connected to said internal electrodes on each of said opposing sides of said laminate; and a buffer portion formed within the laminate extending between a non-deflecting portion located in the vicinity of each side of said laminate and a deflecting portion located within said laminate between said portions of said plate surfaces covered by the internal electrodes, said buffer portion having a deflection amount which increases gradually from 0% at a position adjacent to the non-deflecting portion to 100% at a position adjacent to the deflecting portion, and including said internal electrode at a ratio increasing gradually from 0% at a position adjacent to the non-deflecting portion to 100% at a position adjacent to the deflecting portion.

Claim 3

A laminate type displacement element comprising: a plurality of plates of an electrochemical conversion material, each said plate including opposite first and second surfaces and opposite first and second sides, said first surface being laminated with an internal electrode material extending from said first side to cover a portion of said first surface, said second surface being laminated with an internal electrode material extending from said second side to cover a portion of said second surface, defining a portion of said plate where said internal electrode material disposed on each surface overlaps, said plurality of plates being stacked together with said first and second surfaces of adjoining plates opposing one another to form a stack having opposite first and second side portions and defining a deflecting portion internal to said stack corresponding to said overlapping portions of said plurality of plates having a predetermined deflection amount; a first external electrode laminated to said first side portion of said stack, electrically contacting said internal electrodes on said first surfaces of said plurality of plates and defining a first non-deflecting portion at said first side portion of said stack having zero deflection; a second external electrode laminated to said second side portion of said stack electrically contacting said internal electrodes on said second surfaces of said plurality of plates and defining a second non-deflecting portion at said second side portion of said stack having zero deflection; a first buffer zone disposed between said deflecting portion internal to said stack and said first non-deflecting portion at said first side portion of said stack, said first buffer zone having a deflection amount increasing from zero at said first non-deflecting portion to said predetermined deflection amount at said deflecting portion; and a second buffer zone disposed between said deflecting portion internal to said stack and said second non-deflecting portion at said second side portion of said stack, said second buffer zone having a deflection amount increasing from zero at said second non-deflecting portion to said predetermined deflection amount at said deflecting portion.

Claim 4

A laminate type displacement element comprising: a plurality of plates of an electrochemical conversion material, each said plate including opposite first and second surfaces and opposite first and second sides, said first surface being laminated with an internal electrode material extending from said first side to cover a portion of said first surface, said second surface being laminated with an internal electrode material extending from said second side to cover a portion of said second surface, defining a portion of said plate where said internal electrode material disposed on each surface overlaps, said plurality of plates being stacked together with said first and second surfaces of adjoining plates opposing one another to form a stack having opposite first and second side portions and defining a deflecting portion internal to said stack corresponding to said overlapping portions of said plurality of plates having a predetermined deflection amount; a first external electrode laminated to said first side portion of said stack, electrically contacting said internal electrodes on said first surfaces of said plurality of plates and defining a first non-deflecting portion at said first side portion of said stack having zero deflection; a second external electrode laminated to said second side portion of said stack electrically contacting said internal electrodes on said second surfaces of said plurality of plates and defining a second non-deflecting portion at said second side portion of said stack having zero deflection; a first buffer zone disposed between said deflecting portion internal to said stack and said first non-deflecting portion at said first side portion of said stack, said first buffer zone having a deflection amount increasing from zero at said first non-deflecting portion to said predetermined deflection amount at said deflecting portion; and a second buffer zone disposed between said deflecting portion internal to said stack and said second non-deflecting portion at said second side portion of said stack, said second buffer zone having a deflection amount increasing from zero at said second non-deflecting portion to said predetermined deflection amount at said deflecting portion.

Claim 5

The laminate-type displacement element according to claim 2, wherein said deflection amount in said first and second buffer zones increases at a stepped rate of increase.

Claim 6

The laminate type displacement element according to claim 2, wherein said deflection amount in said first and second buffer zones increases at a gradual rate of increase.

Claim 7

The laminate-type displacement element according to claim 2, wherein said electromechanical conversion material is a piezoelectric ceramic material.

Claim 8

The laminate-type displacement element according to claim 2, wherein said electromechanical conversion material is an electrostriction material.

Claim 9

The laminate-type displacement element according to claim 2, wherein said internal electrodes are laminated on said plurality of thin plates by a screen printing method.

Claim 10

The laminate-type displacement element according to claim 2, further including an insulating layer and an electrode layer laminated on said buffer portion by a screen printing method.

Claim 11

A laminate-type displacement element, comprising: a plurality of thin plates having opposing surfaces made of an electromechanical conversion material having a piezoelectric strain constant d O and laminated with internal electrodes alternately covering portions of said opposing surfaces of said plates, said plurality of plates stacked to form a laminate having opposing sides; a pair of external electrodes connected to said internal electrode on each of said opposing sides of said laminate; and a buffer portion formed within the laminate extending between a non-deflecting portion located in the vicinity of each side of said laminate and a deflecting portion located within said laminate between said portions of said plate surfaces covered by the internal electrodes, said buffer portion having a deflection amount which increases gradually from 0% at a position adjacent to the non-deflecting portion to 100% at a position adjacent to the deflecting portion, said buffer portion further being made of a material having a piezoelectric strain constant d, with a ratio of d/d O increasing gradually from 0 at a position adjacent to the non-deflecting portion to 1 at a position adjacent to the deflecting portion.

Claim 12

A laminate-type displacement element, comprising: a plurality of thin plates having opposing surfaces made of an electromechanical conversion material having a piezoelectric strain constant d O and laminated with internal electrodes alternately covering portions of said opposing surfaces of said plates, said plurality of plates stacked to form a laminate having opposing sides; a pair of external electrodes connected to said internal electrode on each of said opposing sides of said laminate; and a buffer portion formed within the laminate extending between a non-deflecting portion located in the vicinity of each side of said laminate and a deflecting portion located within said laminate between said portions of said plate surfaces covered by the internal electrodes, said buffer portion having a deflection amount which increases gradually from 0% at a position adjacent to the non-deflecting portion to 100% at a position adjacent to the deflecting portion, said buffer portion further being made of a material having a piezoelectric strain constant d, with a ratio of d/d O increasing gradually from 0 at a position adjacent to the non-deflecting portion to 1 at a position adjacent to the deflecting portion.

Claim 13

A laminate-type displacement element, comprising: a plurality of thin plates having opposing surfaces made of an electromechanical conversion material laminated with internal electrodes having a thickness t alternately covering portions of said opposing surfaces of said plates, said plates stacked to form a laminate having opposing sides; a pair of external electrodes connected to said internal electrodes on each of said opposing sides of said laminate; and a buffer portion formed within the laminate extending between a non-deflecting portion located in the vicinity of each side surface of said laminate and a deflecting portion located within said laminate between said portions of said plate surfaces covered by the internal electrodes, said buffer portion having a deflection amount which increases gradually from 0% at a position adjacent to the non-deflecting portion to 100% at a position adjacent to the deflecting portion and is coated with an insulating layer having a thickness t 1 and an electrode layer having a thickness t 2 wherein t 1 +t 2 =t, and the thickness t 1 of said insulating layer continuously decreases from t at a position adjacent to said non-deflecting portion to 0 at a position adjacent to said deflecting portion.

Claim 14

A laminate-type displacement element, comprising: a plurality of thin plates having opposing surfaces made of an electromechanical conversion material laminated with internal electrodes having a thickness t alternately covering portions of said opposing surfaces of said plates, said plates stacked to form a laminate having opposing sides; a pair of external electrodes connected to said internal electrodes on each of said opposing sides of said laminate; and a buffer portion formed within the laminate extending between a non-deflecting portion located in the vicinity of each side surface of said laminate and a deflecting portion located within said laminate between said portions of said plate surfaces covered by the internal electrodes, said buffer portion having a deflection amount which increases gradually from 0% at a position adjacent to the non-deflecting portion to 100% at a position adjacent to the deflecting portion and is coated with an insulating layer having a thickness t 1 and an electrode layer having a thickness t 2 wherein t 1 +t 2 =t, and the thickness t 1 of said insulating layer continuously decreases from t at a position adjacent to said non-deflecting portion to 0 at a position adjacent to said deflecting portion.