Ultrasonic transducers
First Claim
1. A ultrasonic emitter comprising a resonant unit including an actve element having a front surface facing in a forward direction and having a rear surface facing in a rearward direction, said active element being operative to generate ultrasonic vibrations in response to an applied signal, said resonant unit including a liquid disposed to the rear of said active element, said resonant unit being resonant at an ultrasonic frequency and adapted to emit ultrasonic vibrations at said ultrasonic frequency principally in said forward direction.
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0 Petitions
Accused Products
Abstract
A compact, high-power ultrasonic emitting transducer has an active element such as a piezoelectric element and structure defining a reflective backing interface such as an air interface behind the rear surface of the active element. A liquid is provided in the resonant unit between the backing interface and the active element.
205 Citations
24 Claims
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1. A ultrasonic emitter comprising a resonant unit including an actve element having a front surface facing in a forward direction and having a rear surface facing in a rearward direction, said active element being operative to generate ultrasonic vibrations in response to an applied signal, said resonant unit including a liquid disposed to the rear of said active element, said resonant unit being resonant at an ultrasonic frequency and adapted to emit ultrasonic vibrations at said ultrasonic frequency principally in said forward direction.
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2. An ultrasonic emitter comprising:
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(a) an active element having a front surface facing in a forward direction and a rear surface facing in a rearward direction, said active element being operative to generate ultrasonic vibrations in response to an applied signal;
(b) a rear structure defining a space disposed to the rear of said active element,; and
c) a liquid in said space, said element, said rear structure and said liquid cooperatively forming a resonant unit adapted to emit ultrasonic vibrations in said forward direction, said resonant unit including a backing interface, said liquid being disposed between said backing interface and said rear surface of said active element. - View Dependent Claims (4, 5, 7, 8, 9, 10, 11)
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3. An ultrasonic emitter comprising:
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(a) an active element having a front surface facing in a forward direction and a rear surface facing in a rearward direction, said active element being operative to generate ultrasonic vibrations in response to an applied signal;
(b) a rear structure defining a space disposed to the rear of said active element,; and
(c) a liquid in said space, said active element, said rear structure and said liquid cooperatively forming a resonant unit adapted to emit ultrasonic vibrations in said forward direction, said resonant unit including a backing interface, said liquid at least partially defining said backing interface. - View Dependent Claims (6)
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12. An ultrasonic emitter comprising:
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(a) a tubular piezoelectric element having an interior bore, an inner surface bounding said bore and an outer surface;
(b) an interior structure extending within said bore, said interior structure including a first tube substantially coaxial with said tubular piezoelectric element so that said first tube and said piezoelectric element cooperatively define an annular passageway therebetween;
(c) a gas disposed within said first tube; and
(d) means for connecting the annular passageway to a source of a liquid. - View Dependent Claims (13, 14, 15, 16, 17)
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18. A method of emitting ultrasound comprising the steps of:
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(a) providing a resonant unit including an active element having a front surface facing in a forward direction, said resonant unit including a liquid disposed to the rear of said active element, said resonant unit being resonant at an ultrasonic frequency; and
(b) driving said active element at said frequency so as to cause said active element to generate ultrasonic vibrations at said frequency, said resonant unit emitting ultrasonic vibrations principally in said forward direction. - View Dependent Claims (19, 20, 21, 22, 23)
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24. A method of emitting ultrasound comprising the steps of:
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(a) driving an active element having front and rear surfaces at an ultrasonic frequency so that said active element generates ultrasonic vibrations at said frequency;
(b) passing a liquid through a space between the rear surface of the active element and an acoustically reflective interface so that said liquid removes heat from the active element and so that ultrasonic vibrations propagated from the rear surface of the active element pass through the liquid to the reflective interface, are reflected at the interface and pass back through the liquid to the active element, said reflective interface backing said element and directing the ultrasonic vibrations out of the element substantially through said front surface.
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Specification