Title:
PIEZOELECTRIC-TYPE ELECTROACOUSTIC CONVERSION DEVICE
Document Type and Number:
WIPO Patent Application WO/2013/121477
Kind Code:
A1
Abstract:
[Problem] To make a piezoelectric element resistant to damage even if a shock such as from a drop is received, and improve the flatness of a frequency sound pressure characteristic. [Solution] A lower-surface outer edge portion of a circular support plate (2) comprising plastic is affixed on an upper surface of a ring-shaped frame (1). A circular through-hole (3) is provided in the center portion of the support plate (2). A lower-surface outer edge portion of a circular metal plate (4) is affixed to an upper surface at the circumference of the through-hole (3) in the support plate (2). A groove (6) is provided in a ring shape on the inner side of an upper-surface outer edge portion of the metal plate (4). A shock-absorbing member (7) comprising a carbon-based material, polyurethane or another elastic material is provided within the groove (6) in the metal plate (4). A piezoelectric element (8) is provided on an upper surface of an inner edge portion of the shock-absorbing member (7) at the upper surface and circumference of the metal plate (4) in the inner side of the shock-absorbing member (7). By means of the existence of the shock-absorbing member (7), the piezoelectric element (8) is resistant to damage even if a shock such as from a drop is received, and the flatness of a frequency sound pressure characteristic is capable of being improved.
Inventors:
ONISHI YASUHARU (JP)
MURATA YUKIO (JP)
KISHINAMI YUICHIRO (JP)
KOMODA MOTOYOSHI (JP)
MURATA YUKIO (JP)
KISHINAMI YUICHIRO (JP)
KOMODA MOTOYOSHI (JP)
Application Number:
PCT/JP2012/006376
Publication Date:
August 22, 2013
Filing Date:
October 04, 2012
Export Citation:
Assignee:
NEC CASIO MOBILE COMM LTD (JP)
ONISHI YASUHARU (JP)
MURATA YUKIO (JP)
KISHINAMI YUICHIRO (JP)
KOMODA MOTOYOSHI (JP)
ONISHI YASUHARU (JP)
MURATA YUKIO (JP)
KISHINAMI YUICHIRO (JP)
KOMODA MOTOYOSHI (JP)
International Classes:
H04R17/00; H01L41/09; H01L41/187
Foreign References:
| JP2007104318A | 2007-04-19 | |||
| JP2004058668A | 2004-02-26 | |||
| JP2004364334A | 2004-12-24 | |||
| JPS5934800A | 1984-02-25 |
Other References:
See also references of EP 2816821A4
Attorney, Agent or Firm:
KASHIMA, Hidemi (JP)
Hidemi Kajima (JP)
Hidemi Kajima (JP)
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Claims: