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US4431936A
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Transducer structure for generating uniform and focused ultrasonic beams and applications thereof
Assignee: Leland Stanford Junior University
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Filing: 1982-02-18
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Granted: 1984-02-14
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Expires: 2002-02-18
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
2026-10-23 23:23
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/66; G01F1/662; G01P; G01P5/00; G01P5/24; G10; G10K; G10K11/00; G10K11/18; G10K11/26; G10K11/34; G10K11/341; G10K11/348; G01N; G01N2291/00; G01N2291/02; G01N2291/028; G01N2291/02836
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
59 words
A transducer structure for use in ultrasonic flow measurements comprising a first planar disc-shaped transducer element for generating and receiving a first uniform ultrasonic beam, a second annular transducer element about said first transducer element, and lens means on one surface of said second transducer element for receiving a second ultrasonic beam which is focused within said first beam.
Claim 2
Dependent Claim
59 words
A transducer structure for use in ultrasonic flow measurements comprising a first planar disc-shaped transducer element for generating and receiving a first uniform ultrasonic beam, a second annular transducer element about said first transducer element, and lens means on one surface of said second transducer element for receiving a second ultrasonic beam which is focused within said first beam.
Claim 3
Dependent Claim
19 words
The transducer structure as defined by claim 1 and further including insulation between said first and second transducer elements.
Claim 4
Dependent Claim
29 words
The transducer structure as defined by claim 1 or 2 wherein the thickness of said first transducer element is on the order of one-half an ultrasonic operating frequency wavelength.
Claim 5
Dependent Claim
94 words
A transducer structure for use in ultrasonic flow measurements and like applications where uniform and focused beams are required comprising a plurality of concentric transducer elements, a central element of said plurality of transducer elements being a disc, an outer element of said plurality of transducer elements including a lens for defining said focused beam, and a linear array of elements centrally disposed through said plurality of transducer elements, said plurality of concentric elements generating a first uniform beam and a second narrow beam and said linear array generating a scan beam for imaging.
Claim 6
Dependent Claim
94 words
A transducer structure for use in ultrasonic flow measurements and like applications where uniform and focused beams are required comprising a plurality of concentric transducer elements, a central element of said plurality of transducer elements being a disc, an outer element of said plurality of transducer elements including a lens for defining said focused beam, and a linear array of elements centrally disposed through said plurality of transducer elements, said plurality of concentric elements generating a first uniform beam and a second narrow beam and said linear array generating a scan beam for imaging.
Claim 7
Dependent Claim
90 words
A transducer structure for use in ultrasonic flow measurements and like applications where uniform and focused beams are required comprising a plurality of concentric transducer elements, said plurality of transducer elements being selectively energizable to define a focused beam, a central element of said plurality of transducer elements being a disc, and a linear array of elements centrally disposed through said plurality of transducer elements, said plurality of concentric elements generating a first uniform beam and a second narrow beam and said linear array generating a scan beam for imaging.
Claim 8
Dependent Claim
90 words
A transducer structure for use in ultrasonic flow measurements and like applications where uniform and focused beams are required comprising a plurality of concentric transducer elements, said plurality of transducer elements being selectively energizable to define a focused beam, a central element of said plurality of transducer elements being a disc, and a linear array of elements centrally disposed through said plurality of transducer elements, said plurality of concentric elements generating a first uniform beam and a second narrow beam and said linear array generating a scan beam for imaging.
Claim 9
Dependent Claim
139 words
The transducer structure as defined by claim 4 or 5 wherein each concentric transducer element is amplitude weighted 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 the driving signals r 1 , r 2 . . . , r N are the radii of the elements from the center outward N is the number of elements α 1 , α 2 , . . . , α N are positive zeroes of the Bessel function J 1 (x) b=r n /α n and ##EQU13## where t is integration variable g o (·) is defined by g o (v)=v·f o (v/b) f o (u) is the desired beam pattern where u is (2π/λ sin θ, and θ is the field direction.
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) | 1987-02-13 | 1987-08-15 | 1988-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-13 | 1991-08-15 | 1992-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-13 | 1995-08-15 | 1996-02-14 | $7700.00 | Window Closed / Lapsed |