Patent US4680499A successfully refreshed from Google Patents.
US4680499A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Piezoelectric ultrasonic transducer with acoustic matching plate
Assignee: Hitachi Healthcare Manufacturing Ltd
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Filing: 1986-04-09
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Granted: 1987-07-14
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Expires: 2006-04-09
Abstract
Abstract A monolithic array ultrasonic transducer has a plurality of transducer elements formed thereon by isolating metallized areas on a piezoelectric plate without cutting the piezoelectric plate apart for each transducer element, and an acoustic matching layer having a longitudinal wave velocity within ±25% of a longitudinal wave velocity of the piezoelectric plate and a thickness equal to one half of that of the piezoelectric plate. The acoustic matching layer suppresses the radiation to an object of a partial wave in a direction of 60° to a normal line to the plane of the piezoelectric plate.
Inventors
- 👤 Shin'ichiro Umemura
- 👤 Hiroshi Takeuchi
- 👤 Kageyoshi Katakura
- 👤 Chitose Nakaya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 12:12
CPC Classifications
G; G10; G10K; G10K11/00; G10K11/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
83 words
An ultrasonic transducer comprising: a piezoelectric plate having both surfaces thereof metallized and at least one of the surfaces having a plurality of isolated metallized areas; a backing material formed on the back surface of said piezoelectric plate; and an acoustic matching plate formed on the front surface of said piezoelectric plate, having a longitudinal wave velocity within ±25% of a longitudinal wave velocity of said piezoelectric plate and having a thickness equal to one half of a thickness of said piezoelectric plate.
Claim 2
Dependent Claim
83 words
An ultrasonic transducer comprising: a piezoelectric plate having both surfaces thereof metallized and at least one of the surfaces having a plurality of isolated metallized areas; a backing material formed on the back surface of said piezoelectric plate; and an acoustic matching plate formed on the front surface of said piezoelectric plate, having a longitudinal wave velocity within ±25% of a longitudinal wave velocity of said piezoelectric plate and having a thickness equal to one half of a thickness of said piezoelectric plate.
Claim 3
Dependent Claim
29 words
An ultrasonic transducer according to claim 1, wherein the longitudinal wave velocity of said acoustic matching plate is within ±15% of the longitudinal wave velocity of said piezoelectric plate.
Claim 4
Dependent Claim
18 words
An ultrasonic transducer according to claim 1, wherein said acoustic matching layer is made of polymethylole melamine resin.
Claim 5
Dependent Claim
129 words
An ultrasonic transducer comprising: a piezoelectric plate having both surfaces thereof metallized and at least one of the surfaces having a plurality of isolated metallized areas; a backing material formed on the back surface of said piezoelectric plate; a first acoustic matching layer formed on the front surface of said piezoelectric plate and having a longitudinal wave velocity within ±25% of a longitudinal wave velocity of said piezoelectric plate and a thickness equal to one half of a thickness of said piezoelectric plate; and a second acoustic matching layer formed between said piezoelectric plate and said backing material and having a longitudinal wave velocity within ±25% of the longitudinal wave velocity of said piezoelectric plate and a thickness no larger than 1/4 of a thickness of said piezoelectric plate.
Claim 6
Dependent Claim
129 words
An ultrasonic transducer comprising: a piezoelectric plate having both surfaces thereof metallized and at least one of the surfaces having a plurality of isolated metallized areas; a backing material formed on the back surface of said piezoelectric plate; a first acoustic matching layer formed on the front surface of said piezoelectric plate and having a longitudinal wave velocity within ±25% of a longitudinal wave velocity of said piezoelectric plate and a thickness equal to one half of a thickness of said piezoelectric plate; and a second acoustic matching layer formed between said piezoelectric plate and said backing material and having a longitudinal wave velocity within ±25% of the longitudinal wave velocity of said piezoelectric plate and a thickness no larger than 1/4 of a thickness of said piezoelectric plate.
Claim 7
Dependent Claim
32 words
An ultrasonic transducer according to claim 4, wherein the longitudinal wave velocities of said first and second acoustic matching layers are within ±15% of the longitudinal wave velocity of said piezoelectric plate.
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) | 1990-07-13 | 1991-01-12 | 1991-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-13 | 1995-01-12 | 1995-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-13 | 1999-01-12 | 1999-07-14 | $7700.00 | Window Closed / Lapsed |