US4350917A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency-controlled scanning of ultrasonic beams
Assignee: Riverside Research Institute
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Filing: 1980-06-09
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Granted: 1982-09-21
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Expires: 2000-06-09
Abstract
Abstract An ultrasonic wave transducer is formed from a body of piezoelectric material having nonuniform thickness. Each location on the transducer is resonant at a different frequency according to the thickness at that point. By changing the frequency of the applied excitation signal, the origin and direction of the radiation can be altered.
Inventors
- 👤 Frederic L. Lizzi
- 👤 Kurt W. Weil
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:11
CPC Classifications
B; B06; B06B; B06B1/00; B06B1/02; B06B1/06; B06B1/0644; G; G10; G10K; G10K11/00; G10K11/18; G10K11/26; G10K11/34
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
122 words
A transducer, responsive to supplied electrical signals within a selected frequency range, for radiating said signals as ultrasonic waves, comprising a body of material having selected acoustic characteristics and having at least a first curved surface, a second opposite surface and a thickness between said surfaces, which thickness is different for different selected locations on said curved surface, said thickness being a resonant thickness in said material at said different locations for different frequencies in said frequency range, whereby when said electrical signals are applied to said body, said body resonates between said surfaces at locations on said curved surface according to the frequency spectrum of said electrical signals, and said body radiates ultrasonic waves from said curved surface at said locations.
Claim 2
Dependent Claim
122 words
A transducer, responsive to supplied electrical signals within a selected frequency range, for radiating said signals as ultrasonic waves, comprising a body of material having selected acoustic characteristics and having at least a first curved surface, a second opposite surface and a thickness between said surfaces, which thickness is different for different selected locations on said curved surface, said thickness being a resonant thickness in said material at said different locations for different frequencies in said frequency range, whereby when said electrical signals are applied to said body, said body resonates between said surfaces at locations on said curved surface according to the frequency spectrum of said electrical signals, and said body radiates ultrasonic waves from said curved surface at said locations.
Claim 3
Dependent Claim
13 words
A transducer as set forth in claim 1 wherein said material is piezoelectric.
Claim 4
Dependent Claim
31 words
A transducer as set forth in claim 2 wherein said curved surface and said opposite surface are metal clad, and said electrical signals are applied to said body by said cladding.
Claim 5
Dependent Claim
14 words
A transducer as set forth in claim 1 wherein said second surface is curved.
Claim 6
Dependent Claim
17 words
A transducer as set forth in claim 1 wherein all cross-sections of said curved surface are curved.
Claim 7
Dependent Claim
34 words
A transducer as set forth in claim 4 wherein one of said curved surfaces is convex and other of said curved surfaces is concave, whereby said body comprises a portion of a curved shell.
Claim 8
Dependent Claim
15 words
A transducer as set forth in claim 1 wherein said second surface interfaces with air.
Claim 9
Dependent Claim
30 words
A transducer as set forth in claim 7 wherein a selected material having acoustic characteristics simulating fluid is adjacent said first surface, whereby said body radiates into said selected material.
Claim 10
Dependent Claim
28 words
A transducer as set forth in claim 1 wherein said selected frequency range encompasses a range wherein the highest frequency is less than three times the lowest frequency.
Claim 11
Dependent Claim
27 words
A transducer as set forth in claim 9 wherein said thickness varies over a range where the greatest thickness is less than three times the smallest thickness.
Claim 12
Dependent Claim
13 words
A transducer as set forth in claim 4 wherein said surfaces are spherical.
Claim 13
Dependent Claim
109 words
A transducer as set forth in claim 1 wherein said transducer has contour lines of constant thickness, said lines being transverse to a selected path on said surface, each thickness being resonant at a particular frequency in said frequency range, whereby application of a signal at a selected frequency causes said body to radiate ultrasonic waves from all areas over said line of constant thickness corresponding to said selected frequency, and said body radiates ultrasonic waves in a pattern determined partially by the length of said line, and whereby variation of said selected frequency causes movement of said areas of radiation in a direction corresponding to said selected path.
Claim 14
Dependent Claim
25 words
A transducer as specified in claim 12 wherein said selected path is a line formed by the intersection of a plane and said curved surface.
Claim 15
Dependent Claim
15 words
A transducer as specified in claim 12 wherein said selected path is a zig-zag line.
Claim 16
Dependent Claim
49 words
A transducer as specified in claim 13 wherein said first curved surface is a first sphere, wherein said second surface is a second sphere with an offset center from said first sphere, wherein said lines comprise approximately lines of latitude, and wherein said path is a circumference of longitude.
Claim 17
Dependent Claim
35 words
A transducer as set forth in claim 6 wherein said shell is divided into a plurality of sections of constant thickness and each of said sections is resonant at a corresponding frequency of applied signals.
Claim 18
Dependent Claim
109 words
In a transducer for radiating ultrasonic waves in response to supplied electrical signals wherein there is provided a body of material having selected acoustic characteristics, the improvement wherein said body has at least one curved surface and an opposite surface, and wherein the thickness between said surfaces is different for different selected locations on said curved surface, and resonant at different locations for different frequencies of applied signals, whereby when said electrical signals are applied to said body, said body resonates at a location on said curved surface according to the frequency of said electrical signals, and said body radiates ultrasonic waves from said curved surface at said location.
Claim 19
Dependent Claim
109 words
In a transducer for radiating ultrasonic waves in response to supplied electrical signals wherein there is provided a body of material having selected acoustic characteristics, the improvement wherein said body has at least one curved surface and an opposite surface, and wherein the thickness between said surfaces is different for different selected locations on said curved surface, and resonant at different locations for different frequencies of applied signals, whereby when said electrical signals are applied to said body, said body resonates at a location on said curved surface according to the frequency of said electrical signals, and said body radiates ultrasonic waves from said curved surface at said location.
Claim 20
Dependent Claim
93 words
Apparatus for radiating sonic waves into a medium comprising a transducer element of selected acoustic characteristics having at least one curved surface, an opposite surface, and a thickness therebetween, said thickness being different at different selected locations on said curved surface, and means connected to said transducer for generating and supplying electrical signals at various frequencies within a selected frequency range; whereby, when a signal at a particular frequency is applied to said transducer element, a location having a thickness that is resonant at said frequency will radiate sonic waves at said location.
Claim 21
Dependent Claim
93 words
Apparatus for radiating sonic waves into a medium comprising a transducer element of selected acoustic characteristics having at least one curved surface, an opposite surface, and a thickness therebetween, said thickness being different at different selected locations on said curved surface, and means connected to said transducer for generating and supplying electrical signals at various frequencies within a selected frequency range; whereby, when a signal at a particular frequency is applied to said transducer element, a location having a thickness that is resonant at said frequency will radiate sonic waves at said location.
Claim 22
Dependent Claim
17 words
Apparatus as set forth in claim 18, wherein said transducer element is a body of piezoelectric material.
Claim 23
Dependent Claim
30 words
Apparatus as set forth in claim 19, wherein said curved surface and said opposite surface are metal clad, and said electrical signals are applied to said body by said cladding.
Claim 24
Dependent Claim
16 words
Apparatus as set forth in claim 18, wherein said generating means is a variable frequency generator.
Claim 25
Dependent Claim
40 words
Apparatus as set forth in claim 21, wherein said variable frequency generator is a voltage-controlled oscillator arranged to sequentially generate a plurality of frequencies within said selected frequency resonating each said location on said curved surface in a desired sequence.
Claim 26
Dependent Claim
27 words
Apparatus as set forth in claim 18, wherein said selected frequency range encompasses a range wherein the highest frequency is less than three times the lowest freeuqncy.
Claim 27
Dependent Claim
42 words
Apparatus as set forth in claim 18 wherein said generating means is arranged to provide a broad-band signal having a plurality of simultaneous frequency components within said selected frequency range to simultaneously resonate a corresponding plurality of locations on said curved surface.
Claim 28
Dependent Claim
59 words
In a system for radiating ultrasonic waves from a transducer into an unbounded region of space, wherein a signal generator supplies electrical signals which are radiated as ultrasonic waves by a transducer, the improvement wherein said signal generator generates signals of different frequencies and said transducer radiates said signals as ultrasonic waves in different directions for different signal frequencies.
Claim 29
Dependent Claim
59 words
In a system for radiating ultrasonic waves from a transducer into an unbounded region of space, wherein a signal generator supplies electrical signals which are radiated as ultrasonic waves by a transducer, the improvement wherein said signal generator generates signals of different frequencies and said transducer radiates said signals as ultrasonic waves in different directions for different signal frequencies.
Claim 30
Dependent Claim
26 words
Apparatus as specified in claim 25 wherein said transducer includes a body having tapered thickness whereby said body resonates at different locations for said different frequencies.
Claim 31
Dependent Claim
54 words
Apparatus for radiating acoustic signals, comprising a radiating aperture, resposive to acoustic signals of different frequencies, for radiating said signals into different directions in an unbounded region of space from said aperture, the direction of radiation being determined by the frequency of said signal, and means for supplying acoustic signals to said radiating aperture.
Claim 32
Dependent Claim
54 words
Apparatus for radiating acoustic signals, comprising a radiating aperture, resposive to acoustic signals of different frequencies, for radiating said signals into different directions in an unbounded region of space from said aperture, the direction of radiation being determined by the frequency of said signal, and means for supplying acoustic signals to said radiating aperture.
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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) | 1985-09-20 | 1986-03-22 | 1986-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-09-20 | 1990-03-22 | 1990-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-09-20 | 1994-03-22 | 1994-09-21 | $7700.00 | Window Closed / Lapsed |