Parametric audio system
First Claim
1. A parametric audio system for generating at least one airborne audio beam, comprising:
- at least one audio signal source configured to provide at least one audio signal;
at least one signal conditioner configured for receiving the at least one audio signal and for nonlinearly processing the audio signal to provide at least one pre-distorted signal;
a modulator configured to receive the pre-distorted signal and to convert the pre-distorted signal into ultrasonic frequencies; and
an acoustic transducer array including plurality of acoustic transducers, the array being configured to receive the converted signal and to project the converted signal through the air along a selected path, thereby inverting distortion in the projected signal and regenerating the audio signal along at least a portion of the selected path with reduced net distortion,wherein the acoustic transducer array has a bandwidth greater than 5 kHz, andwherein the acoustic transducer array further includes;
a backplate having a surface and a succession of depressions formed on the surface, the respective depressions having different depths; and
a membrane with at least one conductive surface adjacently disposed along the backplate,wherein the membrane and the succession of depressions define the plurality of acoustic transducers, each of the plurality of acoustic transducers having an associated center frequency determined at least in part by the depth of the respective depression;
wherein the depressions formed on the surface of the backplate alternate in succession between at least one depression having at least one first specified depth and at least one depression having at least one second specified depth, andwherein the spacing between the center frequencies determined at least in part by the at least one first specified depth and the at least one second specified depth is sufficient to obtain an aggregate frequency response of the acoustic transducer array having the bandwidth greater than 5 kHz.
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Accused Products
Abstract
A parametric audio system having increased bandwidth for generating airborne audio signals with reduced distortion. The parametric audio system includes a modulator for modulating an ultrasonic carrier signal with a processed audio signal, a driver amplifier for amplifying the modulated carrier signal, and an array of acoustic transducers for projecting the modulated and amplified carrier signal through the air along a selected projection path to regenerate the audio signal. Each of the acoustic transducers in the array is a membrane-type transducer. Further, the acoustic transducer array is a phased array capable of electronically steering, focusing, or shaping one or more audio beams.
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Citations
22 Claims
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1. A parametric audio system for generating at least one airborne audio beam, comprising:
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at least one audio signal source configured to provide at least one audio signal; at least one signal conditioner configured for receiving the at least one audio signal and for nonlinearly processing the audio signal to provide at least one pre-distorted signal; a modulator configured to receive the pre-distorted signal and to convert the pre-distorted signal into ultrasonic frequencies; and an acoustic transducer array including plurality of acoustic transducers, the array being configured to receive the converted signal and to project the converted signal through the air along a selected path, thereby inverting distortion in the projected signal and regenerating the audio signal along at least a portion of the selected path with reduced net distortion, wherein the acoustic transducer array has a bandwidth greater than 5 kHz, and wherein the acoustic transducer array further includes; a backplate having a surface and a succession of depressions formed on the surface, the respective depressions having different depths; and a membrane with at least one conductive surface adjacently disposed along the backplate, wherein the membrane and the succession of depressions define the plurality of acoustic transducers, each of the plurality of acoustic transducers having an associated center frequency determined at least in part by the depth of the respective depression; wherein the depressions formed on the surface of the backplate alternate in succession between at least one depression having at least one first specified depth and at least one depression having at least one second specified depth, and wherein the spacing between the center frequencies determined at least in part by the at least one first specified depth and the at least one second specified depth is sufficient to obtain an aggregate frequency response of the acoustic transducer array having the bandwidth greater than 5 kHz. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A parametric audio system for generating at least one airborne audio beam, comprising:
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at least one audio signal source configured to provide at least one audio signal; at least one signal conditioner configured for receiving the at least one audio signal and for nonlinearly processing the audio signal to provide at least one pre-distorted signal; a modulator configured to receive the at least one pre-distorted signal and to convert the pre-distorted signal into ultrasonic frequencies; at least one driver amplifier configured to receive the at least one converted signal, wherein the at least one converted signal is an undivided signal, the at least one driver amplifier being further configured to generate at least one amplified signal representative of the undivided converted signal; an acoustic transducer array including a plurality of acoustic transducers, the array being configured to receive the at least one amplified signal and to project the amplified signal through the air for inverting distortion in the projected signal and for subsequent regeneration of the audio signal with reduced net distortion; a matching filter configured to compensate for a frequency response of the combination of the acoustic transducer array and the driver amplifier; and a delay circuit configured to apply at least one predetermined time delay to the at least one converted signal, wherein the acoustic transducer array further includes; a backplate having a surface and a succession of depressions formed on the surface, the respective depressions having different depths; and a membrane with at least one conductive surface adjacently disposed along the backplate; wherein the membrane and the succession of depressions define the plurality of acoustic transducers, each of the plurality of acoustic transducers having an associated center frequency determined at least in part by the depth of the respective depression; wherein the depressions formed on the surface of the backplate alternate in succession between at least one depression having at least one first specified depth and at least one depression having at least one second specified depth, and wherein the spacing between the center frequencies determined at least in part by the at least one first specified depth and the at least one second specified depth is sufficient to obtain an aggregate frequency response of the acoustic transducer array having a bandwidth greater than 5 kHz. - View Dependent Claims (20, 21)
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22. An acoustic transducer array, comprising:
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a backplate including a surface and a succession of depressions formed on the surface, the respective depressions having different depths; and a membrane with at least one conductive surface adjacently disposed along the backplate, wherein the acoustic transducer array has a bandwidth greater than 5 kHz, wherein the membrane and the succession of depressions define the plurality of acoustic transducers, each of the plurality of acoustic transducers having an associated center frequency determined at least in part by the depth of the respective depression, wherein the depressions formed on the surface of the backplate alternate in succession between at least one depression having at least one first specified depth and at least one depression having at least one second specified depth, and wherein the spacing between the center frequencies determined at least in part by the at least one first specified depth and the at least one second specified depth is sufficient to obtain an aggregate frequency response of the acoustic transducer array having the bandwidth greater than 5 kHz.
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Specification