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US 7,079,450 B2Granted
System and method for eliminating audible noise for ultrasonic transducers
AssigneeAutomotive Technologies International, Inc.
InventorsDavid S. Breed, Wilbur E. DuVall, Wendell C. Johnson
Life of this patent
Estimating the term…
Abstract
Methods for reducing clicking of ultrasonic air-coupled transducers in which a mechanical filter that attenuates audible frequencies relative to ultrasonic frequencies is placed in the path of the ultrasonic waves as the travel from the transducer to a target such as an object in the vehicle compartment.
Claims24
A method for producing ultrasonic sound waves with an ultrasonic transducer to realize reduced audible noise, the method comprising:
- arranging a filter which attenuates low frequencies to a greater extent than higher frequencies in front of a wave emitting and receiving member of the ultrasonic transducer and in the path of ultrasonic sound waves being emitted from the wave emitting and receiving member;
- and
- applying a transducer drive signal as input to the ultrasonic transducer to produce ultrasonic sound waves at the wave emitting and receiving member which pass through the filter and provide filtered ultrasonic sound waves with reduced audible noise effects.
A method for producing ultrasonic sound waves with an ultrasonic transducer to realize reduced audible noise, the method comprising:
- arranging a filter that selectively attenuates audio frequencies relative to ultrasonic frequencies in front of a wave emitting and receiving member of the ultrasonic transducer and in the path of ultrasonic sound waves being emitted from the wave emitting and receiving member;
- and
- applying a transducer drive signal as input to the ultrasonic transducer to produce ultrasonic sound waves at the wave emitting and receiving member which pass through the filter and provide filtered ultrasonic sound waves with reduced audible noise effects.
An ultrasonic ranging system, comprising:
- an ultrasonic transducer for generating ultrasonic sound waves at a wave emitting and receiving member and transmitting the ultrasonic sound waves in a transmission path from said wave emitting and receiving member, said ultrasonic transducer being arranged to receive at said wave emitting and receiving member ultrasonic sound waves reflected from a target in the transmission path and convert the received reflected sound waves to an electrical signal;
- a filter for selectively filtering audible frequencies relative to ultrasonic frequencies, said filter being arranged in front of said wave emitting and receiving member of said ultrasonic transducer in the transmission path;
- and
- a processor coupled to said ultrasonic transducer for processing the electrical signal from said ultrasonic transducer into time and distance information to the target.
1 more element
A vehicle including an ultrasonic ranging system, comprising:
- an ultrasonic transducer for generating ultrasonic sound waves at a wave emitting and receiving member and transmitting the ultrasonic sound waves in a transmission path from said wave emitting and receiving member, said ultrasonic transducer being arranged to receive at said wave emitting and receiving member ultrasonic sound waves reflected from an object in an interior compartment of the vehicle in the transmission path and convert the received reflected sound waves to an electrical signal;
- a filter for selectively filtering audible frequencies relative to ultrasonic frequencies, said filter being arranged in front of said wave emitting and receiving member of said ultrasonic transducer in the transmission path;
- and
- a processor coupled to said ultrasonic transducer for processing the electrical signal from said ultrasonic transducer into time and distance information to the object.
1 more element
An ultrasonic ranging system, comprising:
- an ultrasonic transducer for generating ultrasonic sound waves and transmitting the ultrasonic sound waves in a transmission path, said ultrasonic transducer being arranged to receive ultrasonic sound waves reflected from a target in the transmission path and convert the received reflected sound waves to an electrical signal;
- a filter for selectively filtering audible frequencies relative to ultrasonic frequencies, said filter being arranged in front of said ultrasonic transducer in the transmission path;
- a housing, said ultrasonic transducer and said filter both being arranged in said housing with said filter being more proximate an opening of said housing through which the ultrasonic waves pass;
- and
- a processor coupled to said ultrasonic transducer for processing the electrical signal from said ultrasonic transducer into time and distance information to the target.
2 more elements
A vehicle including an ultrasonic ranging system, comprising:
- an ultrasonic transducer for generating ultrasonic sound waves and transmitting the ultrasonic sound waves in a transmission path, said ultrasonic transducer being arranged to receive ultrasonic sound waves reflected from an object in an interior compartment of the vehicle in the transmission path and convert the received reflected sound waves to an electrical signal;
- a filter for selectively filtering audible frequencies relative to ultrasonic frequencies, said filter being arranged in front of said ultrasonic transducer in the transmission path;
- a housing, said ultrasonic transducer and said filter both being arranged in said housing with said filter being more proximate an opening of said housing through which the ultrasonic waves pass;
- and
- a processor coupled to said ultrasonic transducer for processing the electrical signal from said ultrasonic transducer into time and distance information to the object.
2 more elements
Dependencies are inferred from the claim text.