(19)
(11) EP 1 703 571 A8

(12) CORRECTED EUROPEAN PATENT APPLICATION
published in accordance with Art. 158(3) EPC

(15) Correction information:
Corrected version no 1 (W1 A1)

(48) Corrigendum issued on:
06.12.2006 Bulletin 2006/49

(43) Date of publication:
20.09.2006 Bulletin 2006/38

(21) Application number: 04807733.3

(22) Date of filing: 24.12.2004
(51) International Patent Classification (IPC): 
H01L 41/08(2006.01)
H01L 41/22(2006.01)
H04R 17/00(2006.01)
 H01L 41/187(2006.01)
H03H 9/17(2006.01)
(86) International application number:
PCT/JP2004/019376
(87) International publication number:
WO 2005/064699 (14.07.2005 Gazette 2005/28)
(84) Designated Contracting States:
DE FR GB

(30) Priority: 26.12.2003 JP 2003433017

(71) Applicants:
  • Ogawa, Toshio
    Fukuroi-shi, Shizuoka 437-8555 (JP)
  • JFE Mineral Company
    Tokyo 1000005 (JP)

(72) Inventor:
  • OGAWA, Toshio
    Fukuroi-shi, Shizuoka 4378555 (JP)

(74) Representative: HOFFMANN EITLE 
Patent- und Rechtsanwälte Arabellastrasse 4
81925 München
81925 München (DE)

   


(54) PIEZOELECTRIC DEVICE


(57) The present invention provides a piezoelectric device having an extremely good secular characteristic, which is a unimorph (or bimorph) element obtained by sticking to a metal plate a piezoelectric single crystal having a giant-lateral-effect piezoelectric performance of a lateral-vibration-mode electromechanical coupling factor k31 not smaller than 70%, the unimorph (or bimorph) element having a bending-vibration-mode electromechanical coupling factor kb not smaller than 50 % (or 60 %). A plate-form single crystal 10 of PZNT or PMNT is brought into a mono-domain in its thickness direction and in its plate surface so as to be provided with the giant-lateral-effect piezoelectric characteristic, and the single crystal 10 that does not cause secular deterioration is stuck to a metal plate 20 (shim plate) while the mono-domain quality is kept as it is, as a result of which a unimorph 1 (or bimorph 2) is fabricated.