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US4939403A
Expired / Lapsed
US
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Energy-trapping-by-frequency-lowering-type piezoelectric resonance device
Assignee: Murata Manufacturing Co Ltd
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Filing: 1988-12-29
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Granted: 1990-07-03
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Expires: 2008-12-29
Abstract
Abstract An energy trapping type piezoelectric resonance device utilizing higher-order harmonics of the thickness extensional vibration mode comprising a body formed of a piezoelectric material and three or more electrodes arranged overlapping with each other and separated by the piezoelectric material layers in the direction of thickness of the body, wherein respective portions of the piezoelectric material layers interposed between the electrodes are polarized and at least respective portions of the piezoelectric material layers which are not interposed between the electrodes is polarized.
Inventors
- 👤 Toshihiko Kittaka
- 👤 Akira Ando
- 👤 Yukio Sakabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:28
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/15; H03H9/17; H03H9/178
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
126 words
An energy-trapping-by-frequency-lowering-type piezoelectric resonance device utilizing higher order harmonics above the fundamental wave of a thickness extensional mode of vibration, said device comprising: a plate-shaped body formed of piezoelectric material layers; and electrodes arranged so as to be separated by said piezoelectric material layers in a direction of thickness of said body and to trap vibration energy by lowering the resonance frequency; wherein the portions of the piezoelectric material layers sandwiched by said electrodes are polarized; at least portions of the piezoelectric material layers which are not interposed between said electrodes are polarized; and said piezoelectric material has such an effective Poisson's ratio that the piezoelectric material is not usable for fundamental mode energy trapping of the thickness extensional vibration mode by lowering the resonance frequency.
Claim 2
Dependent Claim
126 words
An energy-trapping-by-frequency-lowering-type piezoelectric resonance device utilizing higher order harmonics above the fundamental wave of a thickness extensional mode of vibration, said device comprising: a plate-shaped body formed of piezoelectric material layers; and electrodes arranged so as to be separated by said piezoelectric material layers in a direction of thickness of said body and to trap vibration energy by lowering the resonance frequency; wherein the portions of the piezoelectric material layers sandwiched by said electrodes are polarized; at least portions of the piezoelectric material layers which are not interposed between said electrodes are polarized; and said piezoelectric material has such an effective Poisson's ratio that the piezoelectric material is not usable for fundamental mode energy trapping of the thickness extensional vibration mode by lowering the resonance frequency.
Claim 3
Dependent Claim
38 words
A piezoelectric resonance device according to claim 1, wherein the number of said electrodes is three or more, and the piezoelectric material layers interposed between said electrodes are polarized in alternating directions in the direction of the thickness.
Claim 4
Dependent Claim
39 words
A piezoelectric resonance device according to claim 1, wherein the number of said electrodes is three or more; and the piezoelectric material layers interposed between said electrodes are polarized in the same direction in the direction of the thickness.
Claim 5
Dependent Claim
74 words
A piezoelectric resonance device according to claim 1, further comprising connection conductive portions extending from said electrodes to side edges of the body formed of said piezoelectric material layers; said connection conductive portions having respective potentials when said piezoelectric resonance device is driven; and wherein at least those of said connection conductive portions which have potentials opposite to each other when driven are formed not overlapping with each other in the direction of thickness.
Claim 6
Dependent Claim
22 words
A piezoelectric resonance device according to claim 1, wherein the number of said electrodes is odd and an even-number harmonic is utilized.
Claim 7
Dependent Claim
21 words
A piezoelectric resonance device according to claim 5, wherein the piezoelectric material has an effective Poisson's ratio of less than 1/3.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-07-02 | 1994-01-01 | 1994-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-02 | 1998-01-01 | 1998-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-02 | 2002-01-01 | 2002-07-03 | $7700.00 | Window Closed / Lapsed |