Patent US4536180A successfully refreshed from Google Patents.
US4243541A
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US
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Piezoelectric ceramics
Assignee: Hitachi Ltd
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Filing: 1978-09-06
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Granted: 1981-01-06
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Expires: 1998-09-06
Abstract
Abstract Piezoelectric ceramics containing PbO and TiO2 as its principal constituents, and further containing 0.5 to 3.7 mol-% of Nd2O3 and 0.2 to 1.5 mol-% of MnO2. Since the piezoelectric ceramics is low in the dielectric constant and is especially small in the temperature coefficient of the delay of surface acoustic waves, it is suitable for a surface acoustic wave device. Piezoelectric ceramics in which 0.3 to 3.3 mol-% of In2O3 is further added to the above-mentioned composition has a still smaller temperature coefficient of the delay of surface acoustic waves, and it is also possible to make this coefficient zero.
Inventors
- 👤 Hiroshi Takeuchi
- 👤 Yukio Ito
- 👤 Shigeru Jyomura
- 👤 Kunio Yamashita
- 👤 Kazuyuki Nagatsuma
- 👤 Sakichi Ashida
- 👤 Mitsuru Ishii
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:48
CPC Classifications
H; H10; H10N; H10N30/00; H10N30/80; H10N30/85; H10N30/853
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
70 words
Piezoelectric ceramics comprising 42.7 to 49.5 mol-% of PbO, 45.2 to 53.1 mol-% of TiO 2 , 0.5 to 3.7 mol-% of Nd 2 O 3 , 0.3 to 3.3 mol-% of In 2 O 3 , and 0.2 to 1.5 mol-% of MnO 2 , the total mol-% of PbO, TiO 2 , Nd 2 O 3 , In 2 O 3 and MnO 2 , being 100 mol-%.
Claim 2
Dependent Claim
70 words
Piezoelectric ceramics comprising 42.7 to 49.5 mol-% of PbO, 45.2 to 53.1 mol-% of TiO 2 , 0.5 to 3.7 mol-% of Nd 2 O 3 , 0.3 to 3.3 mol-% of In 2 O 3 , and 0.2 to 1.5 mol-% of MnO 2 , the total mol-% of PbO, TiO 2 , Nd 2 O 3 , In 2 O 3 and MnO 2 , being 100 mol-%.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-01-06 | 1984-07-07 | 1985-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-06 | 1988-07-07 | 1989-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-06 | 1992-07-07 | 1993-01-06 | $7700.00 | Window Closed / Lapsed |