Dynamic carrier system for parametric arrays
First Claim
1. A method for improving performance of a parametric speaker system, comprising the steps of:
- a) delaying an audio signal prior to parametrically reproducing the audio signal;
b) monitoring a level of the audio signal during the delay; and
c) modulating a carrier envelope based on the monitored level of the audio signal to provide sufficient power to produce a desired audio output and reduce carrier energy when it is not required to reproduce the signal, combining the delayed audio signal with the modulated carrier to parametrically reproduce the audio signal, thereby improving power use efficiency.
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Accused Products
Abstract
A system configured to dynamically adjust the ultrasonic carrier level in a parametric array system in response to changing source signal input levels, and which employs a look-ahead delay strategy to enable optimal modulation of the carrier wave to eliminate constant ultrasonic carrier emission and reduce the ultrasonic carrier emission to what is actually needed to accommodate the db range of the source material, and at the same time, to also minimize noticeable distortion and sound artifacts of a high-power ultrasonic carrier, and/or distortion/artifacts arising from modulation of an ultrasonic carrier to reduce average power output; and thus it realizes advantages of carrier modulation based on source-signal level, while minimizing inherent drawbacks of carrier modulation.
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Citations
26 Claims
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1. A method for improving performance of a parametric speaker system, comprising the steps of:
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a) delaying an audio signal prior to parametrically reproducing the audio signal;
b) monitoring a level of the audio signal during the delay; and
c) modulating a carrier envelope based on the monitored level of the audio signal to provide sufficient power to produce a desired audio output and reduce carrier energy when it is not required to reproduce the signal, combining the delayed audio signal with the modulated carrier to parametrically reproduce the audio signal, thereby improving power use efficiency. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 25)
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14. A method for improving performance of a parametric speaker system, comprising the steps of:
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a) delaying an audio signal prior to parametrically reproducing the audio signal;
b) monitoring a level of the audio signal during the delay; and
c) modulating a carrier envelope to be associated with the audio signal so as to limit growth and decay ahead of and behind rapid changes in the audio signal level to smooth the carrier envelope to reduce audio artifacts resulting from corner modulations, whereby power use efficiency of parametric reproduction is increased and noticeable distortion of the audio signal is reduced. - View Dependent Claims (26)
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15. A system for optimizing carrier signal strength for dynamic audio signal reproduction in a parametric audio reproduction system, comprising:
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a) a time delay processor for delaying an audio signal to enable sensing and processing of the audio signal prior to parametrically reproducing the audio signal;
b) a signal envelope sensor configured to sense an envelope corresponding to a parameter of the audio signal; and
c) a carrier wave generator configured to generate a modulated carrier wave based on the envelope sensed by the signal envelope sensor;
d) wherein the audio signal is delayed, the signal envelope is sensed, and the carrier wave is generated and modulated to improve power use efficiency in parametric reproduction of the audio signal. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23, 24)
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Specification