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Patent US4057324A successfully refreshed from Google Patents.
US4057324A
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Method of making a transparent ferroelectric ceramic element
Assignee: Panasonic Holdings Corp
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Filing: 1975-09-12
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Granted: 1977-11-08
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Expires: 1995-09-12
Abstract
Abstract A method of making an electrooptical system including a transparent ferroelectric ceramic element which possesses memory in that a birefringence corresponding to an applied electric field remains after the field is removed. The electrooptical element is hot-pressed from a family of materials which comprises solid solution of the ternary system, lead magnesium niobate-lead titanate-lead zirconate, and the hot-pressed material may additionally contain a small amount of lanthanum oxide (La2O3).
Inventors
- 👤 Syunichiro Kawashima
- 👤 Masamitsu Nishida
- 👤 Yoshihiro Matsuo
- 👤 Hiromu Ouchi
- 👤 Shigeru Hayakawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:49
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/48; C04B35/49; C04B35/491; C04B35/493; G; G02; G02F; G02F1/00; G02F1/0009; G02F1/0018; G02F1/0027; G02F1/01; G02F1/03; G02F1/055
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
86 words
A method of making a transparent ferroelectric ceramic element, comprising the steps of: forming a solid solution of a material of the formula Pb.sub.1-(3/2)t La.sub.t (Mg.sub.160 Nb.sub.2/3).sub.x Zr.sub.y Ti.sub.z O.sub.e +αPbO, where t=0.04-0.15, x=0.03-0.60, y=0.10-0.95, z=0.05-0.90, x+y+z=1, and α=0.00 -0.20; grinding said solid solution to form a ferroelectric powder; and hot-pressing said powder at a temperature between 900° C and 1300° C and at a pressure of at least 1000 p.s.i. for a period of time which is sufficient to form a transparent ferroelectric ceramic element.
Claim 2
Independent Claim
86 words
A method of making a transparent ferroelectric ceramic element, comprising the steps of: forming a solid solution of a material of the formula Pb.sub.1-(3/2)t La.sub.t (Mg.sub.160 Nb.sub.2/3).sub.x Zr.sub.y Ti.sub.z O.sub.e +αPbO, where t=0.04-0.15, x=0.03-0.60, y=0.10-0.95, z=0.05-0.90, x+y+z=1, and α=0.00 -0.20; grinding said solid solution to form a ferroelectric powder; and hot-pressing said powder at a temperature between 900° C and 1300° C and at a pressure of at least 1000 p.s.i. for a period of time which is sufficient to form a transparent ferroelectric ceramic element.
Claim 3
Dependent Claim
24 words
A method in accordance with claim 1, wherein the step of hot-pressing is performed for a period of time of at least 1 hour.
Claim 4
Dependent Claim
12 words
The transparent ferroelectric ceramic element made by the method of claim 1.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-11-07 | 1981-05-09 | 1981-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-11-07 | 1985-05-09 | 1985-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-11-07 | 1989-05-09 | 1989-11-08 | $7700.00 | Window Closed / Lapsed |