ES2713191T3 - Improved parametric transducer and related methods - Google Patents

Abstract

An ultrasonic audio speaker (6) comprising: a counterplate (104) comprising a first main surface and a conductive zone, the counterplate further comprising a plurality of textural elements disposed on the first main surface; and a flexible layer (46) disposed contiguous with the first main surface of the counterplate, the flexible layer comprising a conductive zone (46a) and an insulating zone (46b), wherein the flexible layer is disposed adjacent the counterplate so that the insulating zone is positioned between the counterplate and the conductive zone of the flexible layer, and so that there is a volume of air between the flexible layer and the surfaces of the textural elements; wherein the counterplate and the flexible layer are configured to be electrically coupled to a respective one of a pair of signal lines carrying an ultrasonic modulated audio carrier, and further where after application of the ultrasonic carrier signal modulated the layer flexible is configured to release a waveform representation of the signal from the ultrasonic carrier modulated to the air; wherein the textural elements comprise a plurality of ridges (120) disposed on the first main surface of the counterplate, the ridges being positioned parallel to each other going through all or part of the counterplate with a corresponding valley disposed between each adjacent pair of parallel ridges; wherein each ridge of the plurality of ridges comprises two surfaces extending from the adjacent valleys and a flattened portion running along a peak of the ridge; and wherein an upper surface (121) of each ridge of the plurality of ridges (121) comprises a plurality of high points (125) and depressions (127) that provide a contour to the upper surface.

Description

DESCRIPTION

Improved parametric transducer and related methods

Technical field

The present description generally refers to parametric loudspeakers. More particularly, some embodiments refer to an ultrasonic emitter.

Background of the invention

The non-linear transduction results from the introduction of audiomodulated ultrasonic signals of sufficient intensity in an air column. Self-modulation, or downward conversion, occurs along the air column that results in the production of an audible acoustic signal. This process occurs due to the well-known physical principle that when two acoustic waves with different frequencies are radiated simultaneously in the same medium, a modulated waveform that includes the sum and difference of the two frequencies is produced by the non-linear interaction (parametric ) of the two acoustic waves. When the two original acoustic waves are ultrasonic waves and the difference between them is selected to be an audio frequency, an audible sound can be generated by the parametric interaction.

The parametric systems of audio reproduction produce sound through the heterodinacion of two acoustic signals in a non-linear process that occurs in a medium such as air. The acoustic signals are typically in the frequency range of ultrasound. The non-linearity of the medium results in acoustic signals produced by the medium that are the sum and difference of the acoustic signals. In this way, two ultrasonic signals that are separated in frequency can result in a differential tone that is within the range of 60 Hz to 20,000 Hz of human hearing.

US 2005/244016 discloses an ultrasonic audio speaker having a counterplate with textural elements, and a layer having a conductive zone, in which the textural elements are ridges and valleys.

Summary

The invention provides ultrasonic speakers defined by claims 1, 6 and 10.

Preferred embodiments are defined in the dependent claims.

Other features and aspects of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate by way of example the features according to embodiments of the invention. The summary is not intended to limit the scope of the invention, which is defined solely by the appended claims.

Brief description of the drawings

The present invention, according to one or more other embodiments, is described in detail with reference to the appended figures. The drawings are given for purposes of illustration only and simply represent typical embodiments or example of the invention. These drawings are provided to facilitate reader understanding of the systems and methods described herein, and should not be construed as limiting the scope, scope, or applicability of the claimed invention.

Some of the enclosed figures illustrate various claims of the invention from different viewing angles. Although the accompanying descriptive text may refer to elements represented therein as being in the "upper part", "lower part" or "side part" of an apparatus, such references are only descriptive and do not imply or require that the invention be put into practice or used in a particular spatial orientation unless explicitly stated otherwise.

Figure 1 is a diagram illustrating an ultrasonic sound system suitable for use with the aforementioned emitter technology.

Figure 2 is a diagram illustrating another example of a signal processing system that is suitable for use with the aforementioned emitter technology.

Figure 3 is an enlarged diagram illustrating an exemplary emitter according to an example of the technology described therein.

Figure 4 is a diagram illustrating a cross-sectional view of an emitter mounted according to the example illustrated in Figure 3.

Figure 5 is a diagram illustrating another exemplary configuration of an ultrasonic emitter.

Figure 6A is a diagram illustrating an example of a simple driver circuit that can be used to drive the aforementioned emitters.

Figure 6B is a diagram illustrating an example of a simple circuit for generating a polarization voltage in the emitter that extracts the necessary voltage from the signal itself. In this example the circuit is designed to polarize at 300 V although other voltages are possible by changing the diode ZD1.

Figure 6C is a diagram illustrating a sectional view of an example of a container core that can be used to form a container core inducer.

Figure 7 is a diagram illustrating another exemplary emitter configuration according to an example of the aforementioned technology.

Figure 8 is a diagram illustrating another exemplary emitter configuration according to an example of the aforementioned technology.

Figure 9A is a diagram illustrating a cross-sectional view of a portion of an irregular surface comprising ridges according to an example of the afore-described technology.

Figure 9B is a diagram illustrating a perspective view of a plurality of rows of the surface of an example of the counterplate 104 shown in Figure 9A.

Figure 9C is a diagram illustrating a perspective view of the irregularities formed in the form of peaks (instead of elongated ridges) used to form an irregular surface.

Figure 10 is a diagram illustrating a view of a cross section of a portion of another embodiment having an irregular surface comprising ridges.

Figure 11A illustrates an exemplary dimension of a textured surface according to the embodiments described above with reference to Figures 9 and 10.

Figure 11B illustrates another exemplary dimension of a textured surface according to the embodiments described above with reference to Figures 9 and 10.

Figure 12A illustrates a cross-sectional view of a textural element according to an embodiment of the aforementioned technology.

Figure 12B illustrates a perspective view of the textural element shown in Figure 12A.

Figure 13 is a diagram illustrating an example of an outline having a plurality of textural elements such as those illustrated in Figure 12.

Figure 14 is a diagram illustrating an example of an outline in which a radiated surface is disposed between each of the contiguous ridges.

Figure 15 is a diagram illustrating exemplary dimensions of a textured surface according to the embodiments described above with reference to Figures 12-14.

Figure 16A illustrates a cross sectional view of an exemplary textured surface according to the aforementioned embodiments.

Figure 16B illustrates a perspective view of an exemplary textured surface according to the aforementioned embodiments.

Figure 17A is a diagram illustrating a top-down view of an exemplary emitter formed in an arcuate configuration.

Figure 17B illustrates a top-down view of an exemplary emitter formed in a cylindrical configuration. Figure 18A illustrates a perspective view of an exemplary emitter in an arcuate configuration.

Figure 18B illustrates a perspective view of an exemplary emitter in a cylindrical configuration.

The figures are not intended to be exhaustive or to limit the invention to the precise form described. It should be understood that the invention can be implemented with modifications and alterations, and that the invention is limited only by the claims.

Description

Embodiments of the aforementioned systems and methods provide a HyperSonic Sound (HSS) audio system or other ultrasonic audio system for a variety of different applications. Certain embodiments provide a thin film ultrasonic emitter for ultrasonic audio carrier applications.

Figure 1 is a diagram illustrating an ultrasonic sound system suitable for use with the systems and methods described herein. In this ultrasonic system 1 as an example, the audio content from an audio source 2 is received, such as, for example, a microphone, memory, a data storage device, unidirectional flow media source, CD, DVD , or another audio source. The audio content can be decoded and converted digitally to analogically, depending on the source. The audio content received by the audio system 1 is modulated in an ultrasonic carrier of frequency f1 using a modulator. The modulator typically includes a local oscillator 3 for generating the ultrasonic carrier signal, and a multiplier 4 for modulating the audio signal on the carrier signal. The resulting signal is a double or single sideband signal with a carrier at the frequency f1. In some embodiments, the signal is a parametric ultrasonic wave or an HSS signal. In most cases the modulation scheme used is the amplitude of modulation, or AM. AM can be achieved by multiplying the ultrasonic carrier by the information transport signal, which in this case is the audio signal. The spectrum of the modulated signal has two sidebands, one upper and one lower sideband, which are symmetric with respect to the frequency of the carrier, and the carrier itself.

The modulated ultrasonic signal is provided to the transducer 6, which sends the ultrasonic wave to the air creating the ultrasonic wave 7. When it is reproduced through the transducer at a sufficiently high acoustic pressure level, due to the non-linear behavior of the air through the which is "reproduced" or transmitted, the signal carrier is mixed with the sideband (s) to demodulate the signal and reproduce the audio content. This is sometimes called a self-demodulation. Therefore, even for single-sideband applications, the carrier is included with the signal sent so that self-demodulation takes place. Although the system illustrated in Figure 3 uses a single transducer to launch a single channel of audio content, a person of ordinary skill in the art after reading this description will understand how many mixers, amplifiers and transducers can be used to transmit multiple channels. of audio using ultrasonic carriers.

An example of a signal processing system 10 that is suitable for use with the aforementioned technology is illustrated schematically in Figure 2. In this embodiment various circuits or processing components are illustrated in the order (relative to the processing path of the signal). signal) in which they are arranged according to an implementation. It is to be understood that the components of the processing circuit may vary, as may the order in which the input signal is processed by each circuit or component. Also, depending on the embodiment, the processing system 10 may include more or fewer components or circuits than shown.

Also, the example shown in Figure 1 is optimized for use in the processing of two input and output channels (eg, a "stereo" signal), with various components or circuits including adaptation components for each signal channel. . A person of ordinary skill in the art will understand after reading this description that the audio system can be implemented using a single channel (eg, a "monaural" or "mono" signal), two channels (as illustrated in FIG. Figure 2), or a greater number of channels. Referring now to Figure 2, the example signal processing system 10 may include audio inputs that may correspond to the left channels 12a and right 12b of an audio input signal. The equalization networks 14a, 14b can be included to provide the equalization of the signal. The equalization networks may, for example, boost or suppress predetermined frequencies or frequency ranges to increase the advantage naturally provided by the emitter / inductor combination of the parametric emitter set.

After the audio signals are compressed, the compressor circuits 16a, 16b can be included to compress the dynamic range of the incoming signal, which effectively raises the amplitude of certain portions of the incoming signals and lowers the amplitude of certain other portions. of the incoming signals. More particularly, compressor circuits 16a, 16b can be included to narrow the range of audio amplitudes. In one aspect, the compressors decrease the peak-to-peak amplitude of the input signals at a ratio of not less than about 2: 1. The adjustment of the input signals to a narrower amplitude range can be made to minimize the distortion, which is characteristic of the limited dynamic range of this class of modulation systems. In other embodiments the equalization networks 14a, 14b may be provided before the compressors 16a, 16b to equalize the signals after compression. In alternative embodiments the compression may take place before the equalization.

The low pass filter circuits 18a, 18b may be included to provide a cut of high portions of the signal, and of high pass filter circuits 20a, 20b that provide a cut of low portions of the audio signals. In the exemplary embodiment, the low pass filters 18a, 18b are used to cut higher signals from about 15-20 kHz, and the high pass filters 20a, 20b are used to cut lower signals of about 20-200 Hz.

The high pass filters 20a, 20b can be configured to eliminate low frequencies which, after modulation, result in the deviation of the carrier frequency (e.g., the portions of the modulated signal of Figure 6 which are the that are closer to the frequency of the carrier). Also some low frequencies are difficult for the system to reproduce efficiently and as a result, a lot of energy can be spent trying to reproduce these frequencies. Therefore, high-pass filters 20a, 20b can be configured to cut these frequencies.

The low pass filters 18a, 18b can be configured to eliminate higher frequencies which, after modulation, result in the creation of an audible pulse signal with the carrier. As an example, if a low-pass filter cuts frequencies above 15 Hz, and the carrier frequency is approximately 44 kHz, the difference signal will not be less than approximately 29 kHz, which is still outside the audible range. for humans. However, if frequencies as high as 25 kHz were allowed to pass the filter circuit, the generated difference signal could be in the 19 kHz range, which is within the range of human hearing.

In the example system 10, after passing through the low-pass and high-pass filters, the audio signals are modulated by the modulators 22a, 22b. The modulators 22a, 22b, mix or match the audio signals with a carrier signal generated by the oscillator 23. For example, in some embodiments a single oscillator (which in one embodiment is driven at a selected frequency of 40 kHz to 50 kHz, whose interval corresponds to readily available crystals that can be used in the oscillator) is used to excite both modulators 22a, 22b. Using a single oscillator for multiple modulators, an identical carrier frequency is provided to multiple channels with the output at 24a, 24b from the modulators. Using the same carrier frequency for each channel decreases the risk that any pulse frequencies can occur. The high pass filters 27a, 27b may also be included after the modulation step. The high-pass filters 27a, 27b can be used to pass the modulated ultrasonic carrier signal and ensure that audio frequencies do not enter the amplifier through the outputs 24a, 24b. Accordingly, in some embodiments, the high pass filters 27a, 27b may be configured to filter signals below about 25 kHz.

Figure 3 is an enlarged diagram illustrating an exemplary emitter according to an example of the aforementioned technology that is not part of the present invention. The exemplary emitter shown in Figure 3 includes a conductive surface 45, another conductive surface 46, an insulating layer 47 and a grid 48. In the illustrated example, the conductive layer 45 is disposed on a counterplate 49. In various embodiments the counterplate 49 is a non-conductive counter plate and serves to isolate the conductive surface 45 on the back side. For example, the conductive surface 45 and the counterplate 49 can be implemented as a metallized layer deposited on a non-conductive substrate, or of relatively low conductivity.

As a further example, the conductive surface 45 and counter plate 49 can be implemented as a printed circuit board (or other similar material) with a metallized layer deposited thereon. As another example, the conductive surface 45 can be laminated or metallized by ion bombardment on the counterplate 49, or applied to the counterplate 49 using various deposition techniques, including vapor deposition or evaporation, and thermal spraying, to name a few. few. As another example, the conductive layer 45 can be a metallized film.

The conductive surface 45 may be a continuous surface or may have slots, holes, cutouts of various shapes, or other non-conductive areas. Additionally, the conductive surface 45 may be a smooth or substantially smooth surface, or it may be rough or pitted. For example, the conductive surface 45 may be embossed, embossed, sanded, sandblasted, formed with peaks or irregularities in the surface, deposited with a desired degree of "orange peel" or otherwise provided with a texture .

The conductive surface 45 need not be disposed on a specialized counterplate 49. Instead, in some embodiments the conductive surface 45 may be deposited on a member providing another function, such as a member that is part of a speaker housing. The conductive surface 45 can also be deposited directly on a wall or other place where the emitter is to be mounted, and so on.

The conductive surface 46 provides another pole of the emitter. The conductive surface can be implemented as a metallized film, wherein a metallized layer is deposited on a substrate of the film (not illustrated separately). The substrate can be, for example, polypropylene, polyimide, polyethylene terephthalate (PET), biaxially oriented polyethylene terephthalate (for example, Mylar, Melinex or Hostaphan), Kapton, or other substrate. In some embodiments the substrate has a low conductivity and, when positioned so that the substrate is between the conductive surfaces of the layers 45 and 46, acts as an insulator between the conductive surface 45 and the conductive surface 46.

Furthermore, in some embodiments the conductive surface 46 (and its insulating substrate where it is included) is separated from the conductive surface 45 by an insulating layer 47. The insulating layer 47 can be made, for example, using PET, axially oriented polyethylene terephthalate. or biaxially, polypropylene, polyimide, or other film or insulating material.

To drive the emitter with sufficient power to achieve a sufficient level of ultrasonic pressure, sparking may occur where the separation between the conductive surface 46 and the conductive surface 45 is too small. However, where the separation is too large, the issuer will not achieve a resonance. In one embodiment, the insulating layer 47 is a layer of approximately 0.92 mil thick. In some embodiments, the insulating layer 47 is a layer of about 0.90 to about 1 mil thick. In subsequent embodiments the insulating layer 47 is a layer from about 0.75 to about 1.2 mil thick. In other embodiments, insulating layer 47 is as thin as about 0.33 or 0.25 mil thick. Other thicknesses may be used, and in some embodiments a separate insulating layer 47 is not disposed. For example, some embodiments rely on an insulating substrate of the conductive layer 46 (e.g., as in the case of a foil film) to provide insulation between the conductive surfaces 45 and 46. One advantage of including an insulating layer 47 is that it may allow the application of a higher level of polarization voltage across the first and second conductive surfaces 45, 46 without producing sparks. When considering the insulating properties of the materials between the two conductive surfaces 45, 46, one should consider the insulating value of layer 47, if included, and the insulating value of the substrate, if any, on which the deposited layer is placed. layer 46.

A grid 48 can be included in the upper part of the stack. The grid 48 can be made of a conductive or non-conductive material. In some embodiments the grid 48 may be the grid that forms the external grid of the speaker. Because the grid 48 is in contact in some embodiments with the conductive surface 46, the grid 48 can be made using a non-conductive material to protect the users from the bias voltage present on the conductive surface 46. The grid 48 can include holes 51, grooves or other openings. These openings may be uniform, or may vary throughout the area, and may be through openings extending from one surface of the grid 48 to the other. The grid 48 can be of various thicknesses. For example, the grid 48 may be approximately 60 mils, although other thicknesses may be used.

The electrical contacts 52a, 52b are used to couple the modulated carrier signal in the transmitter. An example of a driver circuit for the transmitter is described below.

Figure 4 is a diagram illustrating a cross-sectional view of an emitter mounted in accordance with the example illustrated in Figure 3. As illustrated, this embodiment includes the counterplate 49, the conductive surface 45, the conductive surface 46 ( comprising a conductive surface 46a deposited on a substrate 46b), the insulating layer 47 between the conductive surface 45 and the conductive surface 46a, and the grid 48. The dimensions in these and other figures, and particularly the thicknesses of the layers, do not They are drawn to scale. The emitter can be made for almost any dimension. In an application the emitter is of length l, 10 inches and its width or is 5 inches although other dimensions are possible, both major and minor. The practical length and width ranges can be similar lengths and widths of shelf speakers. A larger area of the emitter can lead to a greater sound output, although it may also require higher polarization voltages.

Table 1 describes examples of metallized films that can be used to provide a conductive surface 46. A low laminar strength or low Ohms / Square are preferred for the conductive surface 46. Accordingly, the films in Table 1 that have < 5 and <1 Ohm / Square showed better performance than films with a greater Ohm / Square resistor. Movies that showed 2k or more Ohms / Square did not provide high output levels in the development tests. Kapton can be a desirable material because it is relatively non-sensitive to temperature in the temperature ranges foreseen for the operation of the emitter. Polypropylene may be less desirable because of its relatively low capacitance. A lower capacitance in the emitter means that a greater inductance (and therefore a physically greater inductor) is necessary to form a resonance circuit. As illustrated in Table 1, the films used to provide a conductive surface 46 can vary from about 0.25 mil to 3 mils, including the substrate.

Table 1

Although not shown in Table 1, another pecula that can be used to provide the conductive surface 46 is the Aluminum / Polyimide DE 320 available from Dunmore Corporation. This pekcula is a product based on aluminized polyimide on both sides. It has approximately a thickness of 1 thousand and provides <1 Ohm / Square. As these examples illustrate, any of a number of different metallized films can be provided as the conductive surfaces 45, 46. The metallization is typically performed using a cathode spray or a physical vapor deposition process. Aluminum, nickel, chrome, copper or other conductive materials can be used as a metallic layer, taking into account the preference of a low Ohm / Square material.

Metallized films together with the counterplate typically have a natural resonance frequency to which they will resonate. For some film / counterplate combinations, their natural resonance frequency may be in the range of approximately 30-150 kHz. For example, with a counterplate as described above, some 0.33 mil Kapton films resonate at approximately 54 kHz, while some 1.0 mil Kapton films resonate at approximately 34 kHz. Consequently, the film and the frequency of the carrier of the ultrasonic carrier can be chosen so that the frequency of the carrier coincides with the resonance frequency of the film / counterplate combination. Selecting a carrier frequency at the resonance frequency of the film / counterplate combination can increase the emitter output.

Figure 5 is a diagram illustrating an ultrasonic emitter according to an example of the aforementioned technology and not forming part of the present invention. The example of Figure 5 includes the conductive surfaces 45 and 46 and the grid 48. The difference between the example shown in Figure 5 and that shown in Figures 3 and 4 is that the example shown in Figure 5 does not include a layer separate insulator 47. Layers 45, 46 and 48 can be implemented using the same materials as described above with reference to Figures 3 and 4. Particularly, to avoid the formation of short circuits or the production of sparks between conductive surfaces 45, 46, the conductive surface 46 is deposited on a substrate with insulating properties. For example, the metallized Mylar or Kapton films as the films shown in Table 1 can be used to execute the conductive surface 46, with the film oriented so that the insulating substrate is positioned between the conductive surfaces 45, 46.

Figure 6A is a diagram illustrating an example of a simple driver circuit that can be used to drive the aforementioned transmitters. As appreciated by a person of ordinary skill in the art, where multiple emitters are used (eg, for stereo applications), a driver circuit 50 may be provided for each emitter. In some embodiments the driver circuit 50 is disposed in the same housing or assembly as the emitter. In other embodiments the driver circuit 50 is disposed in a separate housing. This driver circuit is only an example, and a person of ordinary skill in the art will appreciate that other driver circuits may be used with the aforementioned emitter technology.

Typically, the modulated signal from the signal processing system 10 is electronically coupled to an amplifier (not shown). The amplifier may be part of, and in the same housing or enclosure as the driver circuit 50. Alternatively, the amplifier may be housed separately. After amplification, the signal is delivered to the inputs A1, A2 of the exciter circuit 50. In the above-described embodiments, the emitter assembly includes an emitter that may be operable at ultrasonic frequencies. The emitter (not shown in Figure 6) is connected to the driver circuit 50 at the contacts D1, D2. An inductor 54 forms a resonance circuit parallel with the emitter. By configuring the inductor 54 in parallel with the emitter, the current flows through the inductor and the emitter and a parallel resonance circuit can be achieved. Therefore, the capacitance of the emitter becomes important, because the low values of the capacitance of the emitter require a greater inductance to achieve the resonance at a desired frequency. Therefore, the values of the capacitance of the layers, and of the emitter as a whole, can be an important consideration in the design of the emitter.

A polarization voltage is applied across terminals B1, B2 to provide polarization to the emitter. The full-wave rectifier 57 and the filter capacitor 58 provide a DC bias to the circuit through the inputs of the emitter D1, D2. Ideally, the polarization voltage used is approximately twice (or greater than) the inverse polarization that the emitter is expected to take. This is to ensure that the polarization voltage is sufficient to take the emitter out of a reverse polarization state. In one embodiment the bias voltage is in the order of 300-450 Volts, although voltages can be used in other ranges. For example, 350 Volts can be used. For ultrasonic emitters the polarization voltages are typically in the range of a few hundred to several hundred Volts.

Although the series arrangements can be used, by arranging the inductor 54 in parallel with the emitter, advantages can be obtained over the series arrangement. For example, in this configuration, resonance can be achieved in the inductor-emitter circuit without the direct presence of the amplifier in the current path. This can result in a more stable and predictable operation of the transmitter, and it expends less energy compared to the serial configuration.

The obtaining of the resonance in an optimal operation of the system can improve the efficiency of the system (that is, reduces the energy consumed by the system) and reduces the heat produced by the system.

With a series arrangement, the circuit causes the spent current to flow through the inductor. As is known in the art, the emitter will work best at (or close to) the point at which the electrical resonance is achieved in the circuit. However, the amplifier introduces changes in the circuit, which may vary depending on the temperature, signal variation, system operation, etc. In this way, it may be more difficult to obtain (and maintain) a stable resonance in the circuit when the inductor 54 is oriented in series with the emitter (and the amplifier). Figure 6B is a diagram illustrating an example of a simple driver circuit that can be used with the described transmitters aqrn. As noted by a person of ordinary skill in the art, where multiple emitters are used (eg, for stereo applications), a polarization circuit 53 may be provided for each emitter. In some embodiments, the polarization circuit 53 is disposed in the same housing or assembly as the emitter. In other embodiments, the polarizer circuit 53 is disposed in a separate housing. This exciter circuit is only an example, and a person of ordinary skill in the art will appreciate that other exciter circuits can be used with the aforementioned emitter technology.

Typically, the modulated signal from the signal processing system 10 is electronically coupled to an amplifier (not shown). The amplifier may be part of, and in the same housing or enclosure as the driver circuit 53. Alternatively, the amplifier may be housed separately. After the amplification, the signal is delivered to the inputs A1, A2 of the circuit 53. In the above-described embodiments, the transmitter assembly includes an emitter that may be operable at ultrasonic frequencies. The emitter is connected to the exciter circuit 53 at the contacts E1, E2. An advantage of the circuit shown in Figure 5B is that the polarization can be generated from the signal of the ultrasonic carrier and a separate polarization supply is not necessary. In operation the diodes D1-D4 in combination with the capacitors C1-C4 are configured to operate as a rectifier and voltage multiplier. Particularly, diodes D1-D4 and capacitors C1-C4 are configured as a rectifier and quadrupling voltage, which results in a DC bias voltage of up to about four times the carrier's voltage amplitude across the nodes. E1, E2. Other levels of voltage multiplication can be provided using similar known techniques of voltage multiplication.

Capacitor C5 is chosen wide enough to maintain polarization and present an open circuit to the DC voltage at E1 (ie, to prevent the DC from shorting to ground), but small enough to allow the modulated ultrasonic carrier to pass to the emitter. The resistors R1, R2 form a voltage divider, and in combination with the Zener diode ZD1 limit the bias voltage to the desired level, which in the illustrated example is 300 Volts.

The inductor 54 may be of a variety of types known to persons of ordinary skill in the art. However, the inductors generate a magnetic field that can "leak" beyond the confines of the inductor. This field may interfere with the operation and / or response of the issuer. Also, many inductor / emitter pairs used in ultrasonic sound applications operate at voltages that generate large amounts of thermal energy. The heat can also adversely affect the operation of a parametric transmitter.

For at least these reasons, in most conventional parametric sound systems the inductor is physically located at a considerable distance from the emitter. While this solution addresses the aforementioned issues, it adds another complication. The signal carried from the inductor to the emitter can be a relatively high voltage (of the order of 160 V peak to peak or greater). As such, the cables that connect the inductor to the emitter must be qualified for high voltage applications. Also, in certain installations long cable runs may be necessary, which can be expensive and dangerous, and may also interfere with communication systems not related to the parametric transmitter system.

The inductor 54 (which is included as a component as shown in the configurations of Figures 6A and 6B) can be implemented using a core inductor of the container. An inductor of the core of the container is housed within a core of the container that is typically formed of a ferrite material. This limits the windings of the inductor and the magnetic field generated by the inductor. Typically the core of the vessel includes two ferrite halves 59a, 59b that define a cavity 60 within which the windings of the inductor may be disposed. See Figure 6C. An air space G can be included to increase the permeability of the core of the container without affecting the protection capacity of the core. Therefore, by increasing the size of the air space G, the permeability of the core of the container can be increased. However, the increase in air gap G also requires an increase in the number of turns in the inductor (s) maintained within the core of the container in order to achieve a desired amount of inductance. Therefore, an air space can increase the permeability and at the same time reduce the heat generated by the core inductor of the container without compromising the protective properties of the core.

In the examples illustrated in Figures 6A and 6B, a dual winding riser transformer is used. However, the primary 55 and secondary windings 56 can be combined in what is commonly referred to as an autotransformer configuration. Either or both of the primary and secondary windings may be contained within the core of the container.

As discussed above, it is desirable to achieve a parallel resonance circuit with the inductor 54 and the emitter. It is also desirable to match the impedance of the inductor / emitter pair with the impedance expected by the amplifier. This generally requires increasing the impedance of the inductor / emitter pair. It may also be desirable to achieve these objectives as long as the inductor is physically located near the emitter. Therefore, in some embodiments the air gap of the core of the container is selected such that the number of turns in the primary winding 55 presents the impedance load expected by the amplifier. In this way, each circuit loop can be tuned to operate at an increased efficiency level. Increasing the air gap in the container core provides the ability to increase the number of turns in the inductor element 55 without changing the desired inductance of the inductor element 56 (which would otherwise affect the resonance in the emitter loop). In turn, this provides the ability to adjust the number of turns in the inductor element 55 to equalize the impedance load expected by the amplifier.

A further advantage of the increase in the size of the air space is that the physical size of the container core can be reduced. Therefore, a core transformer of the smaller vessel can be used insofar as it provides the same inductance to create a resonance with the emitter.

The use of a step-up transformer provides additional advantages to the present system. Because the transformer "rises" from the direction of the amplifier to the emitter, it necessarily "descends" from the direction of the emitter to the amplifier. In this way, any negative feedback that could otherwise travel from the inductor / emitter pair to the amplifier is reduced by the descent process, thus minimizing the effect of any event on the amplifier and the system in general (in particular, they are reduced the changes in the inductor / emitter pair that could affect the impedance load experienced by the amplifier).

In one embodiment a Litz 30/46 enameled metal wire is used for the primary and secondary windings. The Litz metal thread comprises many thin metal strands, individually insulated and twisted or woven together. The Litz metal wire uses a plurality of individually insulated conductors in parallel. The diameter of the individual conductors is chosen to be less than a depth of penetration in the operating frequency, so that the cords do not suffer an appreciable loss of film effect. Therefore, the Litz metal thread can allow better operation at higher frequencies.

A polarization voltage is applied across terminals B1, B2 to provide polarization to the emitter. The full wave rectifier 57 and the filter capacitor 58 provide a DC bias to the circuit through the inputs of the emitter D1, D2. Ideally, the polarization voltage used is approximately twice (or more) than the inverse polarization that the emitter is expected to take. This is to ensure that the polarization voltage is sufficient to take the emitter out of a reverse polarization state. In one embodiment the polarization voltage is in the order of 350-420 Volts. In other embodiments, other polarization voltages may be used. For ultrasonic emitters, the polarization voltages are typically in the range of a few hundred to several hundred volts.

Although not shown in the figures, when the polarization voltage is high enough, the sparking may occur between the conductive layers 45, 46. This sparking may occur through the intermediate insulation layers as well as in the edges of the emitter (around the outer edges of the insulating layers). Therefore, the insulating layer 47 can be made larger in length and width than the conductive surfaces 45, 46, to prevent sparking at the edge. Also, where the conductive layer 46 is a metallized film on an insulating substrate, the conductive layer 46 can be made greater in length and width than the conductive layer 45 to increase the distance from the edges of the conductive layer 46 to the edges of the conductive layer 46. the conductive layer 45.

The resistor R1 can be included to decrease or flatten the Q factor of the resonance circuit. The resistance R1 is not necessary in all cases and the air as a charge will naturally decrease Q. Similarly, a thinner metal wire Litz in the inductor 54 can also decrease Q so that the peak is not too sharp.

Figure 7 is a diagram illustrating another exemplary configuration of the emitter that is not part of the present invention. The emitter in this configuration includes a conductive grid 65 as the lower layer, an insulating middle layer 47 and an upper conductive layer 46. The layers 46 and 47 can be implemented using the examples for layers 46 and 47 described above with reference to Figures 3 and 4. The conductive grid 65 can be made using a conductive material, or a material with a conductive surface or coating. Because the conductive grid 65 forms one of the emitter electrodes, an input cable 52b is connected to the conductive grid 65.

The conductive grid 65 may have a pattern of holes, slots or other openings. In some embodiments the openings are approximately 50% of the area of the conductive grid 65. In other embodiments the openings may be a greater or lesser percentage of the area of the conductive grid 65. The conductive grid 65 may have approximately a thickness of 60 mils . In other embodiments, the conductive grid 65 may have different thicknesses.

Figure 8 is a diagram illustrating another example of emitter configuration that does not form part of the present invention. The emitter in this configuration includes a conductive grid 65 as the lower layer, an insulating middle layer 47 and an upper conductive layer 46 and an upper grid 48. The emitter illustrated in Figure 8 is similar to the example illustrated in Figure 7, with the addition of the grid 48.

The layers forming the aforementioned emitters can be joined together using several different techniques. For example, frames, clamps, clips, adhesives or other joining mechanisms can be used to join the layers together. The layers can be joined together at the edges to prevent interference with resonance of the emitter films.

As noted above, in various embodiments the conductive surface 45 is provided with an irregular surface. To create an uneven surface, in the above discussed embodiments the surface may be embossed, embossed, sanded, sandblasted, formed with peaks or irregularities on the surface, deposited with a desired degree of "orange peel" or "orange peel". another mode provided with a texture. In other embodiments, the conductive surface 45 may comprise a conductive plate or other member that is formed or provided with ridges or other similar textural elements to present an uneven surface to the conductive emitting film 46.

Figure 9A is a diagram illustrating a cross-sectional view of a portion of an irregular surface comprising ridges according to an example of the afore-described technology and not forming part of the present invention. In the example illustrated in Figure 9A a conductive counterplate 104 is provided with a ridged surface 105. The peaks of the ridged surface 105 support the conductive layer 46. Although the conductive layer 46 is shown as being spaced from the peaks of the ridged surface 105, the conductive layer 46 can rest on or be in contact with the peaks of the surface. 105 with ridges. In some embodiments, the conductive layer 46 comprises a conductive layer 46a and an insulating layer 46b that separates the conductive layer 46a from the peaks. Although not illustrated, when a bias voltage is applied across the emitter, the conductive layer 46 will be brought into more stable contact with the surface 105, causing the layer 46 to make contact with the peaks and, with sufficient polarization, be carried at least partially in the valleys. Preferably, the polarization is not strong enough to bring the layer 46 into full contact with the entire surface 105, since it is desired that a volume of air allow the layer 46 to move in response to the application of the serial modulated audio ultrasonic.

Figure 9B is a diagram illustrating a perspective view of a plurality of rows of the surface of an example of the counterplate 104 shown in Figure 9A. In the illustrated example the peaks of the crested surface 105 extend longitudinally along all or a portion of the counter plate 104. The sections of the counter plate 104 can be fabricated with elongated textural elements 107 (in this example, crests substantially uniforms) extending approximately parallel through all or sections of the counter plate 104. In other embodiments the irregularities 107 in the surface 105 are of shorter lengths. Figure 9C is a diagram illustrating a perspective view of irregularities formed in the form of peaks (rather than elongated ridges) used to form an irregular surface. In the example illustrated in Figure 9C the irregularities of the surface are in the form of square pyramids (with a truncated, flattened peak), although rectangular pyramids could also be used. Although the edges of the irregularities of the surface (e.g., ridges 107 of Figure 9B and pyramids 108 of Figure 9C) are shown as having sharp edges, some or all of the edges of the surface irregularities may have major radios (that is, they can be softened or less acute).

In the example shown in Figure 9 the height of each of the peaks is substantially uniform, or substantially of the same height. In alternative embodiments the peak height of the ridges may vary from row to row or from peak to peak. Figure 10 is a diagram illustrating a cross-sectional view of a portion of an embodiment having an irregular surface comprising ridges. In the embodiment illustrated in Figure 10 the peaks of the surface 111 with ridges are of different heights. In particular, there is a plurality of shorter peaks 114 limited by higher peaks 112. In this example peaks 112 are charged peaks since they support layer 46 of the emitter. The shorter peaks 114 are non-loaded peaks and can be arranged at a chosen height to provide a desired volume of air between the layer 46 of the emitter and the counter plate 104. As with the embodiment illustrated and described with reference to Figure 9B, the surface 111 may comprise a plurality of elongated ridges extending through all or sections of the counter plate 104. Alternatively, as with the embodiment illustrated and described above with reference to FIG. 9C, the surface 111 may comprise a plurality of square or rectangular pyramids arranged on or forming the surface of the counter plate 104. In this case, the loaded pyramids may be arranged in rows so that there are rows of pyramids loaded adjacent to multiple rows of non-loaded pyramids. Alternatively, the loaded pyramids may be arranged so that they are surrounded by non-loaded pyramids.

The heights of textural elements (eg, pyramids) may vary, but are preferably relatively small. Figures 11A and 11b are diagrams illustrating exemplary dimensions for a textured surface according to the embodiments described above with reference to Figures 9 and 10. In the example of Figure 11A the crests or pyramids have a height of 8 miles and they are arranged with a separation of 19 milesimas. The width of the flattened table at the top of the pyramids is 3 milesimas. The angle at the intersection formed between the side walls of the adjacent pyramids is preferably a right angle, although other angles may be used. Similarly, in the example of Figure 11B the pyramids or ridges may be arranged with similar dimensions having a distance of 19 miles, a height of the loaded pyramids is 8 miles, and a peak width is 3 miles. In the exemplary embodiment of Figure 11B the difference in height between the loaded pyramids and the uncharged pyramids can be relatively small, in the order of 0.25-4 thousandths. These dimensions are as examples and however they can be varied from application to application, these examples illustrate that the texture provided by the textural elements can be a fine texture. For example, the height of the ridges where they are pyramids can range from 5 miles to 15 miles, and the separation can range from 12 thousand miles to 100 thousand miles, although in both cases smaller or larger dimensions can be used.

Figure 12, which comprises Figures 12A and 12B, further provides another alternative embodiment for the textural elements of the counterplate. Figure 12A is a cross sectional view of a textural element according to an embodiment of the aforementioned technology, while Figure 12B presents a perspective view. Referring now to Figures 12A and 12B, in this example, a ridge 120 is provided with a cutout top surface 121. The surface 121 includes a plurality of high points 125 and depressions 127 that provide a contour to the top of the element. textural (for example, crest 120).

Also shown in Figure 12A is a conductive layer 46 positioned above the counterplate 104. Although the conductive layer 46 is shown as separate from the peaks of the peaks 120, the conductive layer 46 can rest on or contact the peaks of the pedestal. crested surface 120 provided that the conductive layer 46 comprises an insulating layer 46b between the conductive layer 46a and the counterplate 104. Although not illustrated, when a bias voltage is applied across the emitter, the conductive layer 46 will be brought to a more stable contact with the trimmed top surface 121, causing the plate 46 to contact the high points 125 and, with sufficient polarization, be lowered at least partially to the depressions 127 and valleys between the ridges. Preferably, the polarization is not strong enough to bring the layer 46 into full contact with the entire surface of the counterplate 104, since it is desired that a volume of air allow the layer 46 to move in response to the application of the signal. modulated audio ultrasonic.

Figure 13 is a diagram illustrating an example of an outline having a plurality of textural elements such as those illustrated in Figure 12. In this example the textural elements are arranged in the form of crests positioned parallel to each other going through all or part of the counterplate 104. As shown in this example, the textural elements are forming a V at the base of each textural crest. The angle of the V at the intersection formed between the side walls of the adjacent pyramids is preferably a right angle, although other angles may be used.

In alternative embodiments the textural elements are not in a V-shaped configuration in the valleys between the crests. For example, in an alternative the surface between contiguous ridges 120 is a radius surface (eg, a U-shaped configuration). An example of this is shown in Figure 14 in which a radiated surface 122 is disposed between each of the contiguous ridges 120. As another example, in another alternative, the surface between the contiguous ridges 121 has a flat or flat bottom 123 An example of this is shown in Figure 15, in which the crests 121 are sloping downward from their respective peaks (a constant slope in this example, although a curved surface can also be used) and are on a floor 123 substantially flat of the valley. The transition from the slope of the ridge to the valley floor can be abrupt, or it can be radiated.

The heights of the textural elements (for example, ridges 120) may vary, but are preferably relatively small. Figure 16 is a diagram illustrating exemplary dimensions of a textured surface according to the embodiments described above with reference to Figures 12-15. Figure 16A presents a view of the cross section looking down along the rows of ridges 120, while Figure 16B presents a perspective view looking at a single ridge 120 with a plurality of high points 125 and depressions 127. In the example of Figure 16 the crests 120 have a height of 8 miles, and a distance of 35 miles are separated. The peaks of each ridge are arranged at a distance of 35 miles; the length and width of the table being flattened at the top of the high points 125 of 3 thousands and 30 milesimas, respectively, and the depth of the depressions 127 being 0.0008 ".

These dimensions are as examples and may be varied from application to application however, these examples illustrate that the texture provided by the textural elements may be a fine texture. For example, the height of the ridges or pyramids can range from 5 miles to 15 miles, and the distance can go from 12 miles to 100 miles, although in both cases smaller or larger dimensions can be used.

In these and other embodiments, the depth of the channel between the ridges or pyramids may be an important factor in determining the resonance of the film / counterplate emitter system. Preferably, the frequency of the carrier of the modulated ultrasonic signal is chosen to be at or near the resonance frequency of the emitting system for efficient operation. In various embodiments, the resonant frequency preferably is greater than 35 kHz. In other embodiments, the resonance frequency is preferably greater than 50 kHz. In some embodiments the emitter layer 46 may have a natural resonance frequency of any in the range of 30 to 150 kHz, although alternatives above and below this range are possible. In one embodiment, a film / counterplate emitter with a resonance frequency of 80 kHz is used.

Similarly, the volume of air between the film 46 and the counter plate 104 can be adjusted to form a resonance system in the range of 30 to 150 kHz, although other higher and lower frequencies of this range are possible. In one embodiment, a carrier frequency of 80 kHz is used and the air volume is set to give the resonance frequency of the 80 kHz system. In various applications, the volume of air will be the dominant factor in the determination of the resonance frequency. In other configurations the stiffness of the film will dominate and the volume of air can be chosen arbitrarily. In other configurations both contribute in almost equal amounts. Therefore, concessions may be considered in the design and less than ideal frequency matches may be used.

In the embodiment described above with reference to Figures 9 to 16, as well as in other similar embodiments, the counter plate 104 may be made of aluminum or other conductive material. Aluminum is desirable because of its light weight and corrosion resistance. The aluminum or other conductive material can be machined (e.g., ground), cast, stamped, or otherwise fabricated to form the desired surface pattern for the counterplate 104. Additionally, the counterplate can be made of plastic or other non-plastic material. conductor and then coated with a conductive material such as nickel or aluminum. This non-conductive counterplate may be injection molded, cast, stamped or otherwise manufactured to form the pattern of the desired surface.

The emitter can be manufactured using several different fabrication techniques to join the layer 46 to the counter plate 104. For example, in one embodiment the layer 46 is tensioned along its length and width and fixedly attached to the counter plate 104 using adhesives, mechanical fasteners, or other fixation techniques. By way of another example, a relatively flat area may be arranged around the periphery of the counterplate 104 to present a flat area to which the film 46 may be glued or otherwise secured to the counterplate 104. The film 46 may be glued or otherwise secured to the counter plate 104 along the entire periphery of the counter plate 104 or at selected locations. Additionally, the film 46 can be glued or otherwise secured to the counter plate 104 at selected points or locations within the periphery. The tension applied to the film during manufacture is preferably sufficient tension to soften the film to prevent wrinkles or unnecessarily excess material. Sufficient tension is desirable to allow the film to be brought to the plate after the uniform application of a polarization voltage across the area of the counterplate. In some applications the amount of tension can be of the order of 10 PSI, although other voltages can be used.

To prevent unwanted entry of air between the film 46 and the counterplate 104 during joining operations, one or more air holes may be provided on the back of the counterplate 104 to allow the air to escape. This can prevent the formation of unwanted pressure in the air cavity and prevent "swelling" of the film after assembly.

Additionally, in some embodiments the textured conductive surface of the counterplate may be anodized or otherwise provided with a thin coating of insulating material on the upper surface. As noted above, in some embodiments the film 46 may be a metalized or kapton mylar film with a conductive surface applied to a polymer or other insulating film. When the surface of the counterplate 104 is anodized, a bilayer film (eg, the layers 46a, 46b) is not required to insulate the film 46 from the counterplate 104, and a conductive film (without an insulating layer) can be used.

The conductive and non-conductive layers forming the various aforementioned emitters can be made using flexible materials. For example, the above-described embodiments use flexible metallized films to form conductive layers, and non-metallized films to form resistive layers. Due to the flexible nature of these materials, they can be molded to form desired shapes and shapes. In other embodiments, the layers that can integrate the emitters can be formed using molded or patterned materials to arrive at the desired shape or shape.

For example, as illustrated in Figure 17A, the layers may be applied to a substrate 74 in an arcuate configuration. Figure 18A provides a perspective view of an emitter formed in an arcuate configuration. In this example a backing material 71 is molded or formed with an arched shape and the layers 72 of the emitter attached thereto. Other examples include cylindrical (Figures 17b and 18b) and spherical. As will be apparent to a person of ordinary skill in the art after reading this description, other forms of backup materials can be used on which to form ultrasonic emitters in accordance with the aforementioned technology.

Mylar, kapton and other metallic films can be tensioned or stretched to some extent. The stretching of the film, and the use of the film in a stretched configuration can provide a greater degree of directionality to the emitter. Ultrasonic signals by their nature tend to be directional in nature. However, the stretching of the films gives a higher level of directionality.

Similarly, the conductive layers can be made using any of several conductive materials. Among the common conductive materials that can be used are aluminum, nickel, chromium, gold, germanium, copper, silver, titanium, tungsten, platinum, and tantalum. Alloys of conductive metals can also be used.

As noted above, the conductive layers 45, 46 can be made using metallized films. These include Mylar, Kapton and other similar movies. Such metallized films are available by varying the degrees of transparency from substantially completely transparent to opaque. Similarly, the insulating layer 47 can be made using a transparent film. Accordingly, the aforementioned emitters can be made of transparent materials resulting in a transparent emitter. Such an emitter can be configured to be placed on various objects to form an ultrasonic speaker. For example, one or a pair (or more) of transparent emitters can be placed as a transparent film on a television screen. This can be advantageous because as televisions become thinner there is less space available for large speakers. By placing the emitter (s) on the television screen, the speakers can be placed without requiring additional box space. As another example, an emitter can be placed on a frame of frame, converting a frame into an ultrasonic emitter. Also, because the metallized films can also be highly reflective, the ultrasonic emitter can be made in a mirror.

While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not of limitation. Likewise, the various diagrams may represent an architectural example or other configuration for the invention, which is made to help understand the features and functionality that may be included in the invention. The invention is not limited to the example architectures or configurations illustrated, but the desired features can be implemented using a variety of alternative architectures and configurations. Indeed, it will be apparent to a person skilled in the art as partitioning and alternative functional, logical or physical configurations can be put into practice to put into practice the desired features of the present invention. Also, a multitude of different names of the constituent modules of the present invention. Also a multitude of names of the constituent modules other than the represented aqrn can be applied to the various partitions. Additionally, with respect to the flow charts, the operative descriptions and the method claims, the order in which the steps are presented will not require that various embodiments be put into practice to perform the aforementioned functionality in the same order unless the context demands it in another way.

Although the invention is described above in terms of various embodiments and implementations as an example, it should be understood that the various features, aspects and functionality described in one or more of the individual embodiments are not limited in their applicability to the particular embodiment with which are described, but instead can be applied, alone or in various combinations, to one or more of the other embodiments of the invention, whether or not such embodiments are described and whether or not such features are presented as being a part of an embodiment. described. In this way, the amplitude and scope of the present invention are not limited by any of the exemplary embodiments described above.

The terms and phrases used in this document, and the variations thereof, unless otherwise expressly stated, should be construed as open to the contrary as limiting. As examples of the above: the term "including" must be interpreted as meaning "including, without limitation" or similar; the term "example" is used to provide cases as an example of the subject under discussion, not an exhaustive or limiting list thereof; the terms "a" must be interpreted as meaning "at least one", "one or more" or similar; and adjectives such as "conventional", "traditional", "normal", "patron", "known" and terms of similar meaning should not be construed as limiting the subject described to a given period of time or to a subject available as a given time, but instead should be interpreted to encompass conventional, traditional, normal, or type technologies that may be available or known now or at any time in the future. Likewise, when this document refers to technologies that are obvious or known to a person of ordinary skill in the art, such technologies encompass those that are obvious or known to the skilled artisan now or at any time in the future.

The presence of extended words and phrases such as "one or more", "at least", "but not limited to" or other similar phrases in some cases should not be construed as meaning that the more limited case is intended or required in cases in which such extended phrases may be absent. The use of the term "module" does not imply that the components or functionality described or claimed as part of the module are all configured in a common set. In effect, any or all of the various components of a module, whether the control logic or other components, can be combined in a single set or separately maintained, and can also be distributed in multiple groups or sets or through multiple locations .

Additionally, the various embodiments disclosed herein are described in terms of block diagrams, flowcharts and other illustrations as an example. As will be apparent to a person of ordinary skill in the art after reading this document, the illustrated embodiments and their various alternatives may be put into practice without limitation to the illustrated examples. For example, block diagrams and their accompanying description should not be interpreted as requiring a particular architecture or configuration.

Claims (12)

1. An ultrasonic audio speaker (6) comprising: a counterplate (104) comprising a first main surface and a conductive zone, the counterplate further comprising a plurality of textural elements disposed on the first main surface; and a flexible layer (46) disposed adjacent to the first main surface of the counterplate, the flexible layer comprising a conductive zone (46a) and an insulating zone (46b), wherein the flexible layer is disposed adjacent to the counterplate so that the insulating zone is positioned between the counterplate and the conductive zone of the flexible layer, and so that there is a volume of air between the flexible layer and the surfaces of the textural elements; wherein the counterplate and the flexible layer are configured to be electrically coupled to a respective one of a pair of serial lines that carry an ultrasonic carrier of modulated audio, and furthermore where after the application of the serial of the ultrasonic carrier modulated the layer flexible is configured to release a representation of the pressure wave of the serial of the ultrasonic carrier modulated to the air; wherein the textural elements comprise a plurality of ridges (120) disposed on the first main surface of the counterplate, the ridges being positioned parallel to each other going through all or part of the counterplate with a corresponding valley disposed between each adjacent pair of parallel ridges; wherein each ridge of the plurality of ridges comprises two surfaces extending from adjacent valleys and a flattened portion running along a peak of the ridge; Y wherein an upper surface (121) of each ridge of the plurality of ridges (121) comprises a plurality of high points (125) and depressions (127) that provide an outline to the upper surface. 2. The ultrasonic audio speaker of claim 1, wherein a valley disposed between a contiguous pair of ridges comprises an intersection of contiguous surfaces of the pair of contiguous ridges. 3. The ultrasonic audio speaker of claim 1, wherein a valley disposed between a contiguous pair of ridges comprises a radiated surface between the contiguous surfaces of a pair of contiguous ridges. 4. The ultrasonic audio speaker of claim 1, wherein a valley disposed between a contiguous pair of ridges comprises a flat surface between the contiguous surfaces of the pair of contiguous ridges. 5. The ultrasonic audio speaker of claim 1, wherein the flexible layer comprises a metallized film (45). 6. An electronic transmitter, comprising: a first pole (46) comprising a conductive element having a textured surface; Y a second pole (45) comprising a metallized film disposed adjacent to the textured surface of the pole; wherein, after the application of an audiomodulated ultrasonic carrier the second pole is configured to resonate in response to an audiomodulated serial and to launch a representation of the pressure wave of the serial of the ultrasonic carrier modulated to the air; wherein the textured surface comprises a plurality of ridges (121) disposed on a main surface of a counterplate, wherein the ridges are positioned parallel to each other by going through all or part of the counterplate with a corresponding valley disposed between each adjacent pair. of ridges; wherein each ridge of the plurality of ridges comprises two surfaces extending from adjacent valleys and a flattened portion running along a peak of the ridge; Y wherein an upper surface (121) of each ridge of the plurality of ridges comprises a plurality of high points (125) and depressions (127) that provide a contour to the upper surface. The electronic emitter of claim 6, wherein a valley disposed between a pair of contiguous ridges comprises an intersection of contiguous surfaces of the pair of contiguous ridges. The electronic emitter of claim 6, wherein a valley disposed between a contiguous pair of ridges comprises a radiated surface between the contiguous surfaces of the pair of contiguous ridges. The electronic emitter of claim 6, wherein a valley disposed between a pair of contiguous ridges comprises a planar surface between the contiguous surfaces of the pair of contiguous ridges. 10. An ultrasonic audio speaker comprising: a first layer having a first major surface, a second major surface and a conductive zone; a second layer arranged adjacent the first layer and having a first main surface, a second main surface and a conductive zone; Y an insulating zone disposed between the first and the second layer; wherein the second layer comprises a counterplate and the counterplate comprises a plurality of textural elements; wherein the textural elements comprise a plurality of ridges (120) disposed on a main surface of the counterplate, wherein the ridges are positioned parallel to each other by going through all or part of the counterplate with a corresponding valley disposed between each adjacent pair. of parallel ridges; wherein each ridge of the plurality of ridges (120) comprises two surfaces extending from adjacent valleys and a flattened portion running along a peak of the ridge; Y wherein an upper surface (121) of each ridge of the plurality of ridges comprises a plurality of high points (125) and depressions (127) that provide a contour to the upper surface. The ultrasonic audio speaker of claim 10, wherein the first layer comprises a flexible layer disposed adjacent to the textural elements of the counterplate, the flexible layer having a conductive zone and an insulating zone, wherein the flexible layer is disposed adjacent to the counterplate so that the insulating zone is positioned between the counterplate and the conductive zone of the flexible layer and so that there is a volume of air between the flexible layer and the surfaces of the external elements. 12. The ultrasonic audio speaker of claim 10, wherein the arc of the first and second layers is each configured to be coupled to a respective one of a pair of signal lines carrying an ultrasonic modulated audio carrier, and also , wherein, after the application of the audio modulated ultrasonic carrier, the first layer is configured to launch a representation of a pressure wave of the signal of the ultrasonic carrier modulated to the air.