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US4519260A
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Ultrasonic transducers and applications thereof
Assignee: Leland Stanford Junior University
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Filing: 1984-01-26
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Granted: 1985-05-28
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Expires: 2004-01-26
Abstract
Abstract Transducer structures for use in volume flow measurements which generate a first uniform beam and a second focused beam within the uniform beam. The transducer may include concentric elements, a linear array, or combinations thereof. In a two element concentric array, a central disc generates a uniform beam and a peripheral annular element having a lens thereon defines a second focused beam within the first beam. In a linear array a plurality of juxtaposed linear elements define a scan surface and a segmented element within the linear element array defines a focused reference sample volume within the scanned surface. A concentric array having a plurality of annular elements is driven with amplitude weighting of each element in accordance with a Fourier-Bessel approximation to the desired beam pattern thereby electronically achieving ultrasonic beam width control.
Inventors
- 👤 Chong-Cheng Fu
- 👤 Levy Gerzberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:39
CPC Classifications
G; G10; G10K; G10K11/00; G10K11/18; G10K11/26; G10K11/34; G10K11/341; G10K11/348; G01; G01F; G01F1/00; G01F1/66; G01F1/662; G01P; G01P5/00; G01P5/24
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
111 words
In a transducer structure comprising a plurality of concentric annular transducer elements, a method of energizing said transducer elements and transmitting an ultrasonic beam for use in volume flow measurements with independent amplitude and timing to achieve a Fourier-Bessel approximation, said method comprising the step of amplitude weighting each transducer element in accordance with the equation S.sub.n =b.sup.2 α.sub.n (a.sub.n -a.sub.n+1) where a 1 , a 2 , . . . , a n is the amplitude of driving signals applied to said elements, r 1 , r 2 . . . , r N are the radii of the elements from the center outward, N is the number of elements,
Claim 2
Dependent Claim
111 words
In a transducer structure comprising a plurality of concentric annular transducer elements, a method of energizing said transducer elements and transmitting an ultrasonic beam for use in volume flow measurements with independent amplitude and timing to achieve a Fourier-Bessel approximation, said method comprising the step of amplitude weighting each transducer element in accordance with the equation S.sub.n =b.sup.2 α.sub.n (a.sub.n -a.sub.n+1) where a 1 , a 2 , . . . , a n is the amplitude of driving signals applied to said elements, r 1 , r 2 . . . , r N are the radii of the elements from the center outward, N is the number of elements,
Claim 3
Dependent Claim
75 words
α 1 . α 2 , . . . , α N are positive zeroes of the Bessel function J 1 (x), b=rn/αn, and ##EQU13## where t is the integration variable g o (.) is defined by g o (v)=v·f o (v/b) f o (u) is a desired pattern of said beam, where u is (2π/λ) sin θ, and θ is the field direction of said beam with respect to the axis of said elements.
Claim 4
Dependent Claim
75 words
α 1 . α 2 , . . . , α N are positive zeroes of the Bessel function J 1 (x), b=rn/αn, and ##EQU13## where t is the integration variable g o (.) is defined by g o (v)=v·f o (v/b) f o (u) is a desired pattern of said beam, where u is (2π/λ) sin θ, and θ is the field direction of said beam with respect to the axis of said elements.
Claim 5
Dependent Claim
47 words
The method as defined in claim 1 and further including the steps of transmitting and receiving a first beam having a first width, and transmitting and receiving a second beam having a second width narrower than said first width, said second beam lying within said first beam.
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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) | 1988-05-27 | 1988-11-26 | 1989-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-27 | 1992-11-26 | 1993-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-27 | 1996-11-26 | 1997-05-28 | $7700.00 | Window Closed / Lapsed |