CN219761308U

CN219761308U - Sounding system

Info

Publication number: CN219761308U
Application number: CN202321136947.6U
Authority: CN
Inventors: 辜磊; 毛峻伟; 匡正
Original assignee: Suzhou Hear Acoustic Technology Ltd
Current assignee: Suzhou Hear Acoustic Technology Ltd
Priority date: 2023-05-12
Filing date: 2023-05-12
Publication date: 2023-09-26
Anticipated expiration: 2033-05-12

Abstract

The utility model discloses a sound production system, which comprises an input signal, a pre-processing unit and a loudspeaker, wherein the input signal is directly connected with the loudspeaker and is connected with the loudspeaker through the pre-processing unit, the input signal is processed by the pre-processing unit and then outputs an ultrasonic signal, the ultrasonic signal comprises a first ultrasonic signal and a second ultrasonic signal, the input signal, the first ultrasonic signal and the second ultrasonic signal are all input to the loudspeaker, and the loudspeaker is used for superposing and outputting the input signal and the input signal which is automatically demodulated by the first ultrasonic signal and the second ultrasonic signal through air. The utility model can realize wide coverage range and increase the sound pressure level of audible sound while realizing high directivity.

Description

Sounding system

Technical Field

The utility model relates to the technical field of speakers, in particular to a sound production system integrating a traditional speaker and an ultrasonic speaker.

Background

As shown in fig. 1, the main characteristics of the conventional speaker are: 1) Based on a linear model, namely that the absorption energy of the air medium is in linear relation with the generated sound wave; 2) The sound propagation of the traditional loudspeaker is divergent and has no directivity; 3) The speaker radiates audible sound directly into the air.

With the continuous progress of society, more and more occasions require the use of a speaker having high directivity. In the exhibition hall, the audio directional loudspeaker can only hear the sound of the content displayed by the exhibition hall in a certain area in front of different exhibition halls, so that the sound interference between different exhibition halls can be eliminated, and tens or hundreds of sounds can be played in the same hall without noise pollution; in a market, for example, in a situation where local sounds are required and no interference sounds are generated between areas, such as on an automobile, an airplane, an aerospace ship, a restaurant, a game room, an internet bar, a multi-country conference, etc., different sound services are required to be provided for people in different seats or areas.

The mechanism by which an ultrasonic speaker works is quite different from a conventional speaker. It is a nonlinear, indirect device capable of producing audible sound with high directivity. The ultrasonic speaker emits ultrasonic waves of different frequencies, which have been modulated in the preprocessing, into the air, and generates low-frequency audible sound due to the interactive self-demodulation of the ultrasonic waves, which propagate non-linearly in the air, and propagates to the listener in a highly directional manner. The working principle is shown in fig. 2, f1 and f2 are limited amplitude ultrasonic waves with different frequencies (f 1 and f 2) after the audio signals are modulated in the pretreatment, when the ultrasonic waves are radiated into the air through an ultrasonic transducer and propagate along the same direction, the nonlinear interaction of two fundamental waves can generate two different components, namely the difference (f 1-f 2) between the two frequencies and the sum (f1+f2) of the two frequencies, harmonic waves are generated, and after the harmonic waves enter the air, the amplitude of the higher harmonic waves is small and the attenuation is in direct proportion to the frequency, so that the higher harmonic waves are attenuated faster than the difference frequency component signals, and only the low-frequency audible signals of the difference frequency components still exist after the transmission of a short distance, so that audible sound is formed. The specific signal conversion flow is shown in fig. 3, and it can be seen from the figure that in the forward transmitting process of the ultrasonic frequencies f1 and f2, the sound sources of virtual audible sounds with cumulative effects and frequencies f1-f2 can be demodulated differently to form a situation similar to an end-shooter loudspeaker, so that high-directivity audible sound beams and ultra-long audible sound propagation distances are realized.

The existing ultrasonic speaker has the following defects that 1, because electric energy is required to be converted into ultrasonic waves and then into audible sound, the whole electric energy is slightly low in the conversion efficiency of the audible sound, and the sound pressure level of the audible sound is slightly low when the array size is smaller; 2. ultrasonic speakers are strong in directivity but cannot cover wider directions, and in some scenarios audible sounds need to be switched between strong directivity and wide coverage.

Therefore, how to solve the problems of low efficiency, low sound pressure level and inability to cover wider directions of the existing ultrasonic speaker transducer is currently considered.

The utility model comprises the following steps:

the utility model aims to provide a sound production system integrating a traditional loudspeaker and an ultrasonic loudspeaker.

To achieve the above object, the present utility model provides a sound generating system, comprising: the ultrasonic wave device comprises an input signal, a pre-processing unit and a loudspeaker, wherein the input signal is directly connected with the loudspeaker and is connected with the loudspeaker through the pre-processing unit, the input signal is processed by the pre-processing unit and then outputs an ultrasonic wave signal, the ultrasonic wave signal comprises a first ultrasonic wave signal and a second ultrasonic wave signal, the input signal, the first ultrasonic wave signal and the second ultrasonic wave signal are input to the loudspeaker, and the loudspeaker superimposes and outputs the input signal and the input signal which is demodulated by the first ultrasonic wave signal and the second ultrasonic wave signal through air.

In a preferred embodiment, the input signal is switched to the loudspeaker or the pre-processing unit, or the input signal is input to both the loudspeaker and the pre-processing unit.

In a preferred embodiment, the input signal is audible sound having a frequency in the range of 20Hz to 20 KHz.

In a preferred embodiment, the pre-processing unit includes a signal modulation unit and a power amplification unit connected to the signal modulation unit, where the signal modulation unit modulates the input signal and the ultrasonic carrier signal to generate the first ultrasonic signal and the second ultrasonic signal, and the power amplification unit amplifies the power of the first ultrasonic signal and the second ultrasonic signal and outputs the amplified first ultrasonic signal and the amplified second ultrasonic signal to the speaker.

In a preferred embodiment, the speaker is an electrostatic thin film speaker, or a piezoelectric speaker.

In a preferred embodiment, the electrostatic thin-film speaker includes a plurality of electrostatic sound generating units, each of the electrostatic sound generating units includes a vibration layer, a support column and a base material layer, the vibration layer is laminated on the base material layer, the support column is located between the vibration layer and the base material layer, an air gap for providing a vibration space of the vibration layer is formed between the vibration layer and the base material layer, and the vibration layer vibrates under the action of a loaded voltage.

In a preferred embodiment, the plurality of electrostatic sound generating units are arranged in an array to form a parametric array speaker.

In a preferred embodiment, the vibration layer includes a vibration film and a top electrode on a bottom surface of the vibration film adjacent to the substrate layer.

In a preferred embodiment, the substrate layer includes a fixed bottom plate, a bottom electrode and an insulating layer, the bottom electrode is located on a top surface of the fixed bottom plate near the vibration layer, the insulating layer is located on a top surface of the bottom electrode near the vibration layer, and the support column is located between the top electrode and the insulating layer.

In a preferred embodiment, the voltage applied to the vibration layer includes a dc bias voltage and an ac voltage.

In a preferred embodiment, the piezoelectric speaker includes a plurality of piezoelectric transducers distributed in an array.

Compared with the prior art, the utility model has the following beneficial effects:

1. the utility model integrates the traditional loudspeaker and the ultrasonic loudspeaker, and the loudspeaker outputs the directly input sound source signal and the sound source signal which is automatically demodulated by the ultrasonic signal through air by superposing the input sound source signal to the loudspeaker directly and the input sound source signal which is modulated by the ultrasonic wave to ensure that the loudspeaker can realize wide coverage range and increase the sound pressure level of audible sound while realizing high directivity.

2. The utility model can switch among the traditional loudspeaker, the ultrasonic loudspeaker, the sound emission modes of the traditional loudspeaker and the ultrasonic loudspeaker through controlling the input signals, thereby realizing the diversification of the sound emission modes.

Description of the drawings:

fig. 1 is a sound emission schematic diagram of a conventional speaker;

fig. 2 is a sound emission schematic diagram of a conventional ultrasonic speaker;

fig. 3 is a schematic diagram of sound wave transmission of a conventional ultrasonic speaker;

FIG. 4 is a block diagram of the system of the present utility model;

FIG. 5 is a block diagram of the architecture of the system of the present utility model (after refinement of the pre-processing unit);

FIG. 6 is a block diagram of the system of the present utility model with a control switch;

fig. 7 is a schematic diagram of a specific structure of a speaker according to the present utility model;

FIG. 8 is a diagram showing the simulation effect of three sound modes according to the present utility model.

The reference numerals are:

1. vibration layer, 11, vibration film, 12, top electrode, 2, support column, 3, substrate layer, 31, fixed bottom plate, 32, bottom electrode, 33, insulating layer, 4, air gap.

The specific embodiment is as follows:

the following detailed description of specific embodiments of the utility model is, but it should be understood that the utility model is not limited to specific embodiments.

Throughout the specification and claims, unless explicitly stated otherwise, the term "comprise" or variations thereof such as "comprises" or "comprising", etc. will be understood to include the stated element or component without excluding other elements or components.

As shown in FIG. 4, the sound generating system disclosed by the embodiment of the utility model comprises an input signal, a pre-processing unit and a loudspeaker, wherein the input signal is a sound source signal with the frequency range of 20 Hz-20 KHz, one path of the input signal is directly connected with the loudspeaker, and the other path of the input signal is indirectly connected with the loudspeaker through the pre-processing unit.

Specifically, in this embodiment, as shown in fig. 5, the pre-processing unit includes a signal modulation unit and a power amplification unit, where the signal modulation unit is connected to an input signal and is configured to modulate the input signal with an ultrasonic carrier signal, and at least two paths of ultrasonic signals are generated, and for convenience of description, the signals are respectively defined as a first ultrasonic signal and a second ultrasonic signal. If the input signal is 1KHz and the ultrasonic carrier signal is 40KHz, then the modulated ultrasonic signals with different frequencies are formed, if the first ultrasonic signal is 40KHz and the modulated second ultrasonic signal is 41KHz.

The input end of the power amplifying unit is connected with the output end of the signal modulating unit, the output end of the power amplifying unit is connected with the loudspeaker, and the two paths of ultrasonic signals are input to the power amplifying unit and are amplified by the power amplifying unit and then output to the loudspeaker. The two ultrasonic signals are output by the loudspeaker, and the difference frequency audible sound is demodulated in the forward transmitting process of the two ultrasonic signals.

Preferably, the input signal can be directly input to the speaker, or the input signal is switched to be input to the speaker through the pre-processing unit, or the input signal is input to the speaker through the pre-processing unit, namely when the input signal is directly input to the speaker, the speaker can be used as a traditional speaker, and the sound pressure of the speaker is high and the coverage area is wide; when an input signal is modulated and processed by the pre-processing unit and then is input to the loudspeaker, the loudspeaker can be used as an ultrasonic loudspeaker, and the directivity of the loudspeaker is strong at the moment, but the sound pressure level is slightly lower than that of the traditional loudspeaker; when input signals are input to the loudspeaker and are input to the loudspeaker through the pre-processing unit, the loudspeaker is used for superposing and outputting the input signals and the input signals which are automatically demodulated by air, at the moment, the loudspeaker is an integrated loudspeaker of a traditional loudspeaker and an ultrasonic loudspeaker, and at the moment, the loudspeaker is used for realizing high directivity, and meanwhile, compared with the existing ultrasonic loudspeaker, the loudspeaker widens the sound wave coverage range and simultaneously increases the sound pressure level of audible sound.

As shown in fig. 6, in a specific embodiment, for example, a control switch may be disposed between the input signal and the speaker and between the input signal and the pre-processing unit, and the control switches may be controlled separately, for example, when the control switch between the input signal and the speaker is closed and the control switch between the input signal and the pre-processing unit is opened, the input signal is directly input to the speaker; when the control switch between the input signal and the loudspeaker is opened and the control switch between the input signal and the pre-processing unit is closed, the input signal is processed by the pre-processing unit and then is input to the loudspeaker; for example, when the control switch between the input signal and the speaker is closed and the control switch between the input signal and the pre-processing unit is closed, the input signal is directly input to the speaker and processed by the pre-processing unit and then input to the speaker.

In addition, the present utility model focuses on how to input the input signal to the speaker, and the specific structure of the pre-processing unit is not limited, and the present utility model can be implemented by the prior art, so long as the input signal can be modulated to form two ultrasonic signals.

Further, in implementation, the speaker may be implemented in various structures, for example, an electrostatic thin film speaker, or a piezoelectric speaker. In this embodiment, the speaker is an electrostatic film speaker, and the specific structure thereof includes a plurality of electrostatic sounding units, and the plurality of electrostatic sounding units are preferably arranged in an array to form a parametric array speaker. If a piezoelectric speaker is used, the piezoelectric speaker preferably includes a plurality of piezoelectric transducers distributed in an array, where the piezoelectric transducers may be implemented by existing piezoelectric transducers, which are not described herein.

Specifically, in this embodiment, as shown in fig. 7, each electrostatic sound generating unit includes a vibration layer 1, a support column 2 and a base material layer 3, where the vibration layer 1 is laminated on the base material layer 3, specifically attached to the frame of the base material layer 3, and the support column 2 is located between the vibration layer 1 and the base material layer 3, so that an air gap 4 for providing a vibration space of the vibration layer 1 is formed between the vibration layer 1 and the base material layer 3, and the vibration layer 1 vibrates under the action of a loaded voltage to generate sound.

Wherein the vibration layer 1 specifically comprises a vibration film 11 and a top electrode 12, and the top electrode 12 is positioned on the bottom surface of the vibration film 11, which is close to the substrate layer 3; the base material layer 3 includes a fixing base plate 31, a bottom electrode 32, and an insulating layer 33, the bottom electrode 32 is located on the top surface of the fixing base plate 31 near the vibration layer 1, the insulating layer 33 is located on the top surface of the bottom electrode 32 near the vibration layer 1, and the support column 2 is located between the top electrode 12 and the insulating layer 33. The voltage applied to the vibration layer 1 includes a dc bias voltage Vdc and an ac voltage Vac, wherein the vibration layer 1 is firstly attracted to a direction close to the base material layer 3 under the application of the dc bias voltage Vdc, and then vibrates vertically to the base material layer 3 under the application of the ac voltage Vac to sound.

The simulation is performed with the loudspeaker of one embodiment, and the simulation comparison of directivity at 1m with the input signal of 1kHz is performed in three cases where the input signal is switched to be input to the loudspeaker, and is simultaneously directly input to the loudspeaker and indirectly input to the loudspeaker after being processed by the pre-processing unit. As shown in fig. 8, the solid line in the figure represents the sound emission mode of the conventional speaker, the dotted line represents the sound emission mode of the ultrasonic speaker, and the dash-dot line represents the sound emission mode of the conventional speaker and the ultrasonic speaker as a whole. Simulation data show that the directivity of the sounding mode of the ultrasonic speaker is strongest, the sounding mode of the traditional speaker can achieve wide coverage, the sound pressure level of the sounding mode of the traditional speaker and the ultrasonic speaker is largest, and the sound pressure level of the sound in front of the traditional speaker is increased by 6dB.

The utility model has the advantages that 1, the utility model integrates the traditional loudspeaker and the ultrasonic loudspeaker, and the loudspeaker outputs the directly input sound source signal and the sound source signal which is automatically demodulated by the ultrasonic signal through the air in a superposition way by directly inputting the input sound source signal into the loudspeaker and modulating the input sound source signal by the ultrasonic wave into the loudspeaker, so that the loudspeaker can realize wide coverage range and increase the sound pressure level of audible sound while realizing high directivity. 2. The utility model can switch among the traditional loudspeaker, the ultrasonic loudspeaker, the sound emission modes of the traditional loudspeaker and the ultrasonic loudspeaker through controlling the input signals, thereby realizing the diversification of the sound emission modes.

The foregoing descriptions of specific exemplary embodiments of the present utility model are presented for purposes of illustration and description. It is not intended to limit the utility model to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain the specific principles of the utility model and its practical application to thereby enable one skilled in the art to make and utilize the utility model in various exemplary embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the utility model be defined by the claims and their equivalents.

Claims

1. The sound production system is characterized by comprising an input signal, a pre-processing unit and a loudspeaker, wherein the input signal is directly connected with the loudspeaker and is connected with the loudspeaker through the pre-processing unit, the input signal is processed by the pre-processing unit and then outputs an ultrasonic signal, the ultrasonic signal comprises a first ultrasonic signal and a second ultrasonic signal, the input signal, the first ultrasonic signal and the second ultrasonic signal are input to the loudspeaker, and the loudspeaker superimposes and outputs the input signal and the input signal which is demodulated by the first ultrasonic signal and the second ultrasonic signal through air.

2. A sound generating system according to claim 1, characterized in that the input signal is switched to be input to a loudspeaker or to the pre-processing unit, or the input signal is input to both the loudspeaker and to the pre-processing unit.

3. The sound generating system as claimed in claim 1, wherein the pre-processing unit comprises a signal modulating unit and a power amplifying unit connected to the signal modulating unit, the signal modulating unit modulates the input signal with an ultrasonic carrier signal to generate the first ultrasonic signal and the second ultrasonic signal, and the power amplifying unit amplifies the power of the first ultrasonic signal and the second ultrasonic signal and outputs the amplified power to the speaker.

4. A sound generating system according to claim 1, wherein said speaker is an electrostatic thin film speaker or a piezoelectric speaker.

5. The sound generating system as claimed in claim 4, wherein the electrostatic thin film speaker comprises a plurality of electrostatic sound generating units, each of the electrostatic sound generating units comprises a vibration layer, a support column and a base material layer, the vibration layer is laminated on the base material layer, the support column is located between the vibration layer and the base material layer, an air gap for providing a vibration space of the vibration layer is formed between the vibration layer and the base material layer, and the vibration layer vibrates under the action of a loaded voltage.

6. The sound generating system as claimed in claim 5, wherein the plurality of electrostatic sound generating units are arranged in an array to form a parametric array speaker.

7. The sound generating system of claim 5, wherein the vibrating layer comprises a vibrating membrane and a top electrode, the top electrode being located on a bottom surface of the vibrating membrane adjacent to the substrate layer.

8. The sound generating system of claim 7, wherein the substrate layer comprises a fixed base plate, a bottom electrode and an insulating layer, the bottom electrode is positioned on a top surface of the fixed base plate adjacent to the vibration layer, the insulating layer is positioned on a top surface of the bottom electrode adjacent to the vibration layer, and the support posts are positioned between the top electrode and the insulating layer.

9. The sound generating system of claim 5, wherein the voltage applied to the vibration layer comprises a dc bias voltage and an ac voltage.

10. The sound generating system of claim 4, wherein the piezoelectric speaker comprises a plurality of piezoelectric transducers distributed in an array.