Apparatus and method for driving an ultrasonic transducer
First Claim
1. A method for electromagnetically driving an ultrasonic acoustic transducer, said method comprising the steps of:
- operating in a first mode, wherein the step of operating in said first mode comprises the step of determining a lock-in frequency of said transducer, wherein the step of determining said lock-in frequency comprises the steps of;
exciting said transducer with a first electromagnetic tone burst at a first frequency,measuring a first response of said transducer to said first electromagnetic tone burst,exciting said transducer with a second electromagnetic tone burst at a second frequency,measuring a second response of said transducer to said second electromagnetic tone burst, andselecting said lock-in frequency based on said measured first and second responses; and
operating in a second mode, wherein the step of operating in said second mode comprises the step of driving said transducer with an electromagnetic tone burst at said determined lock-in frequency.
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Accused Products
Abstract
A method and apparatus for electronically driving an ultrasonic acoustic transducer. The transducer is operable in two modes; in a first mode, the lock-in frequency of the transducer is determined; in a second mode, the lock-in frequency determined in the first mode is used to modulate a tone-burst pulse to drive the transducer in an efficient manner. Operating in the first mode, the lock-in frequency is determined by exciting the transducer with a series of tone bursts, where each tone burst comprises an electronic pulse modulated by a tone of one frequency selected from a range of frequencies, and measuring the response of the transducer to each tone burst. In an alternative embodiment, the excitation of the transducer in the first mode is provided by a signal whose frequency is swept over a range. The response of the transducer is sampled at various times during the sweep. The lock-in frequency is chosen by examining the responses and choosing the frequency which gives the best response. Operating in the second mode, the transducer is driven with an electronic tone burst generated by modulating said an electronic pulse with a tone of the determined lock-in frequency.
25 Citations
27 Claims
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1. A method for electromagnetically driving an ultrasonic acoustic transducer, said method comprising the steps of:
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operating in a first mode, wherein the step of operating in said first mode comprises the step of determining a lock-in frequency of said transducer, wherein the step of determining said lock-in frequency comprises the steps of; exciting said transducer with a first electromagnetic tone burst at a first frequency, measuring a first response of said transducer to said first electromagnetic tone burst, exciting said transducer with a second electromagnetic tone burst at a second frequency, measuring a second response of said transducer to said second electromagnetic tone burst, and selecting said lock-in frequency based on said measured first and second responses; and operating in a second mode, wherein the step of operating in said second mode comprises the step of driving said transducer with an electromagnetic tone burst at said determined lock-in frequency. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An electromagnetic driving system for an ultrasonic transducer, said system comprising:
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means for exciting said transducer with a first electromagnetic tone burst at a first frequency; means for measuring a first response of said transducer to said first tone burst; means for exciting said transducer with a second electromagnetic tone burst at a second frequency; means for measuring a second response of said transducer to said second tone burst; and means for selecting a lock-in frequency based on said measured first and second responses. - View Dependent Claims (9, 10, 11, 12)
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13. A method for determining the lock-in frequency of an electromagnetically-driven ultrasonic acoustic transducer, said method comprising the steps of:
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coupling a first signal of a first frequency to said transducer, wherein said first signal is a first electromagnetic tone burst at said first frequency; measuring a first response of said transducer to said first signal; coupling a second signal of a second frequency to said transducer; measuring a second response of said transducer to said second signal; and selecting a lock-in frequency based on said measured first and second responses. - View Dependent Claims (14)
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15. A method for electromagnetically driving an ultrasonic acoustic transducer, said method comprising the steps of:
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operating in a first mode, wherein the step of operating in said first mode comprises the step of determining a lock-in frequency of said transducer, wherein the step of determining said lock-in frequency comprises the steps of; exciting said transducer with an electromagnetic signal swept across a range of frequencies; measuring a first response of said transducer to said electromagnetic signal at a first frequency within said range of frequencies; measuring a second response of said transducer to said electromagnetic signal at a second frequency within said range of frequencies; and selecting said lock-in frequency based on said measured first and second responses; and operating in a second mode, wherein the step of operating in said second mode comprises the step of driving said transducer with an electromagnetic tone burst at said determined lock-in frequency. - View Dependent Claims (16, 17, 18, 19, 20)
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21. An electromagnetic-driving system for an ultrasonic transducer, said system comprising:
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means for exciting said transducer with an electromagnetic signal swept across a range of frequencies; means for measuring a first response of said transducer to said electromagnetic signal at a first frequency; means for measuring a second response of said transducer to said electromagnetic signal at a second frequency; means for selecting a lock-in frequency based on said measured first and second responses; means for driving said transducer with an electromagnetic tone burst at said selected lock-in frequency; and means for receiving acoustic responses from said electromagnetic tone burst at said selected lock-in frequency. - View Dependent Claims (22, 23, 24)
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25. A method for determining the lock-in frequency of an electromagnetically-driven ultrasonic acoustic transducer, said method comprising the steps of:
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exciting said transducer with a tone-burst signal from a tone-burst signal generator at each one of a plurality of frequencies; characterizing the frequency response of said transducer to said tone burst signal; and selecting a lock-in frequency based on said characterized frequency response. - View Dependent Claims (26, 27)
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Specification