Ultrasound based parametric loudspeaker system
First Claim
1. A process for controlling a parametric loudspeaker system, comprising:
- driving one or more resonant transducer elements for ultrasound to produce an AM-signal, which during propagation in a gaseous medium produces an audible signal by self demodulation,providing one or more amplifiers associated with these transducer elements, andproviding one or more modulators associated therewith, which receive an input signal from a signal source,wherein the transducer elements are driven with an FM-modulated signal (FM-modulation) only in the area of the slope of their resonant characteristic lines.
2 Assignments
0 Petitions
Accused Products
Abstract
A parametric loudspeaker system is described which is based upon the FM-modulation of an ultrasound carrier. Known systems work with AM-modulation. The FM-modulation produces a good matching to the resonant transducer such as the conventionally employed piezo-ceramic transducers. The resonance slope of the transducers is used for FM/AM-conversion. This FM-resonance principle can advantageously be employed in a multi-path loudspeaker system, in which the transducer works in the optimal resonance range in each of the paths. With the conventional AM-modulation this is not possible. The FM-resonance principle can also be used in resonance-free or resonance-poor transducers, such as for example electrostatic transducers.
-
Citations
29 Claims
-
1. A process for controlling a parametric loudspeaker system, comprising:
-
driving one or more resonant transducer elements for ultrasound to produce an AM-signal, which during propagation in a gaseous medium produces an audible signal by self demodulation, providing one or more amplifiers associated with these transducer elements, and providing one or more modulators associated therewith, which receive an input signal from a signal source, wherein the transducer elements are driven with an FM-modulated signal (FM-modulation) only in the area of the slope of their resonant characteristic lines. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
-
14. A device for controlling a parametric loudspeaker system, comprising:
-
one or more resonant transducer elements for ultrasound, which can be driven to produce an AM-signal, which during propagation in a gaseous medium produces an audible signal by self demodulation, one or more amplifiers associated with these transducer elements, and one or more modulators associated therewith, which receive an input signal from a signal source, wherein means are provided for driving the transducer elements with an FM-modulated signal (FM-modulation) only in the area of the slope of their resonant characteristic lines. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
-
-
28. A process for controlling a parametric loudspeaker system, comprising:
-
modulating an input signal received from a signal source by at least one FM-modulator having a modulator characteristic line; providing at least one transducer element for ultrasound, the transducer element being capable of producing an AM-signal which during propagation in a gaseous medium produces an audible signal by self demodulation, the transducer dement having a transducer characteristic line that cooperates with the modulator characteristic line to result in a 1;
1 translation of flue input signal; andproviding at lease one amplifier associated with the transducer element, wherein the transducer elements are driven with an FM-modulated signal (FM-modulation) only in the area of the slope of their resonant characteristic lines.
-
-
29. A device for controlling a parametric loudspeaker system, comprising:
-
at least one FM-modulator having a modulator characteristic line for modulating an input signal received from a signal source; at least one transducer element for ultrasound, the transducer element being capable of producing an AM-signal which during propagation in a gaseous medium produces an audible signal by self demodulation, the transducer element having a transducer characteristic line that cooperates with the modulator characteristic line to result in a 1;
1 translation of the input signal; andat lease one amplifier associated with the transducer element, wherein the transducer elements are driven with an FM-modulated signal (FM-modulation) only in the area of the slope of their resonant characteristic lines.
-
Specification