Parametric array loudspeaker and sound field moving system

Abstract

The application discloses a parametric array loudspeaker and a sound field moving system, wherein the parametric array loudspeaker comprises an ultrasonic transducer array, the ultrasonic transducer array comprises a plurality of sound emission channels (1) which are arranged at intervals along a first direction, each of the sound emission channels (1) comprises at least one ultrasonic transducer (2), each of the sound emission channels (1) is independently controlled, and in operation, part of the sound emission channels (1) emit sound and part of the sound emission channels (1) do not emit sound to form a moving sound field by controlling the sound emission channels (1). The parametric array loudspeaker and the sound field moving system can realize sound field moving.

Description

Technical Field

[0001] This invention relates to the field of directional sound technology, and in particular to a parametric array loudspeaker and a sound field movement system. Background Technology

[0002] A parametric array loudspeaker is an acoustic system that uses the nonlinear acoustic effects of a medium to generate directional sound waves. It generates audible difference-frequency sound (frequency f1 to f2) by nonlinear self-demodulation of finite amplitude ultrasound (frequency f1 and f2) through air.

[0003] During forward transmission, ultrasonic frequencies f1 and f2 will demodulate virtual audible sound sources with cumulative effects at frequencies f1 to f2, forming a situation similar to an end-fire array loudspeaker, thereby achieving a highly directional audible sound beam and an ultra-long audible sound propagation distance.

[0004] In order to achieve sound field movement or directional deflection, parametric array loudspeakers are typically used to adjust the phase of each channel through signal processing for functions such as head tracking. Phase adjustment is mainly achieved using delay to compensate for the sound path difference from each channel to the directional sound source.

[0005] Adjusting the phase of each channel using multi-channel signal processing requires controlling the spacing between channels to be smaller than the wavelength corresponding to the ultrasonic frequency; otherwise, sidelobes will appear in the sound field. For example, an ultrasonic transducer array with a frequency of 40 kHz corresponds to a wavelength of approximately 8.6 mm and a width of 0.2 m, requiring at least 24 channels. Similarly, an ultrasonic transducer array with a frequency of 80 kHz corresponds to a wavelength of approximately 4.3 mm and a width of 0.2 m, requiring at least 47 channels. Therefore, using multi-channel signal processing to adjust the phase of each channel requires a large number of channels, increasing system complexity and cost.

[0006] Therefore, it is necessary to improve the existing technology to overcome the aforementioned defects. Summary of the Invention

[0007] The purpose of this invention is to provide a parametric array loudspeaker and a sound field movement system to achieve sound field movement.

[0008] To address the aforementioned technical problems, in a first aspect, the present invention proposes a parametric array loudspeaker, comprising an ultrasonic transducer array, wherein the ultrasonic transducer array includes multiple sound-emitting channels spaced apart along a first direction, each sound-emitting channel including at least one ultrasonic transducer, and each sound-emitting channel being independently controlled. During operation, a moving sound field is formed by controlling some of the multiple sound-emitting channels to emit sound and others to remain silent.

[0009] Preferably, during operation, sound is emitted by a portion of the multiple sound-emitting channels that are set at consecutive intervals, while the remaining sound-emitting channels remain silent, in order to form a moving sound field.

[0010] Preferably, the sound waves emitted by the partially sound-emitting channel at least cover the ears of the sound receiver.

[0011] Preferably, the distance between the centers of two adjacent sound-emitting channels is 1mm to 100mm.

[0012] Preferably, the plurality of sound-emitting channels spaced apart along the first direction form a sound-emitting channel group, and the ultrasonic transducer array includes one or more groups of sound-emitting channels arranged along one or more second directions.

[0013] Preferably, the distance between the centers of two adjacent sound channel groups is 1mm to 100mm.

[0014] Preferably, the first direction is perpendicular to the second direction.

[0015] Preferably, the number of sound channels in each group of sound channels is equal to the size of the ultrasonic transducer array in that direction divided by the distance between the centers of two adjacent sound channels.

[0016] Preferably, the size of the ultrasonic transducer array is 0.1m to 0.5m.

[0017] Secondly, the present invention also proposes a sound field movement system, comprising:

[0018] The location acquisition module is used to collect the location information of the target object;

[0019] The control module, connected to the position acquisition module and the aforementioned parametric array loudspeaker, is used to control the sound-emitting channels in the ultrasonic transducer array corresponding to the position information of the target object to emit sound, while the other sound-emitting channels do not emit sound, so as to form a moving sound field and align it with the target object.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] The parametric array loudspeaker of this invention divides an ultrasonic transducer array into multiple spaced sound channels. Each sound channel includes at least one ultrasonic transducer, and each sound channel is independently controlled. The sound field is moved by controlling the sounding or non-sounding state of each sound channel. The number of channels does not need to consider the phase and spacing of each channel. Therefore, fewer channels can be used to achieve sound field movement, which can be applied to functions such as head tracking. Moreover, compared with adjusting the phase of each channel, controlling the sounding or non-sounding state of each channel has lower overall system complexity and requires less computing resources, which can significantly reduce costs. Attached Figure Description

[0022] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the invention and are not intended to specifically limit the shapes and proportions of the components. Those skilled in the art, guided by the teachings of this invention, can select various possible shapes and proportions to implement the invention according to specific circumstances. In the drawings:

[0023] Figure 1 This is a schematic diagram of parametric array loudspeaker technology in the existing field;

[0024] Figure 2 This is a schematic diagram illustrating the principle of highly directional propagation in parametric array loudspeakers in existing technology.

[0025] Figure 3 This is a schematic diagram of a parametric array loudspeaker in this invention;

[0026] Figure 4 This is a schematic diagram showing that any ultrasonic transducer in this invention belongs to only one channel;

[0027] Figure 5 This is another structural schematic diagram of the parametric array loudspeaker in this invention;

[0028] Figure 6 This is a schematic diagram of the sound field movement system in one state in this invention;

[0029] Figure 7 This is a schematic diagram of the sound field movement system in this invention generating sound in another state;

[0030] Figure 8 This is a schematic diagram of the sound field movement system in this invention. Detailed Implementation

[0031] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0032] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0034] like Figure 3 and Figure 4 A parametric array loudspeaker, corresponding to a preferred embodiment of the present invention, includes an ultrasonic transducer array. The ultrasonic transducer array includes a plurality of sound-emitting channels 1 spaced apart along a first direction. Each sound-emitting channel 1 includes at least one ultrasonic transducer 2, which is used to emit directional sound. Each sound-emitting channel 1 is independently controlled to emit sound. During operation, a moving sound field is formed by controlling some of the multiple sound-emitting channels 1 to emit sound and others to remain silent.

[0035] In implementation, it is preferable to control the continuous, spaced-apart sound-emitting channels 1 to emit sound, while the remaining sound-emitting channels 1 remain silent to create a moving sound field. Generally, when the sound receiver is near the left side of the ultrasonic transducer array, several sound-emitting channels 1 near the left side of the array are controlled to emit sound; when the sound receiver is near the center of the array, several sound-emitting channels 1 near the center are controlled to emit sound; similarly, when the sound receiver is near the right side of the array, several sound-emitting channels 1 near the right side are controlled to emit sound. In implementation, the number of sound-emitting channels 1 emitting sound in each case is not limited, as long as it at least covers both ears of the sound receiver.

[0036] As Figure 3 Taking a specific embodiment as an example, the ultrasonic transducer array includes six sound-emitting channels 1, which are defined as the first sound-emitting channel 1 to the sixth sound-emitting channel 1 for ease of description. When the sound receiver is close to the left side of the ultrasonic transducer array, the first sound-emitting channel 1 to the third sound-emitting channel 1, which are set at continuous intervals, are activated, while the other sound-emitting channels 1 (i.e., the fourth sound-emitting channel 1 to the sixth sound-emitting channel 1) are silent. When the sound receiver moves to the middle of the ultrasonic transducer array, the second sound-emitting channel 1 to the fourth sound-emitting channel 1, which are set at continuous intervals, are activated, while the other sound-emitting channels 1 (i.e., the first sound-emitting channel 1, the fifth sound-emitting channel 1, and the sixth sound-emitting channel 1) are silent, or the fourth sound-emitting channel 1 to the sixth sound-emitting channel 1, which are set at continuous intervals, are activated, while the other sound-emitting channels 1 (i.e., the first sound-emitting channel 1 to the third sound-emitting channel 1) are silent.

[0037] like Figure 3 As shown, there is a certain distance d1 between the centers of two adjacent sound channels 1. This distance d1 is adapted to the movement accuracy of the moving sound field. For example, if the accuracy is high, the number of sound channels will increase accordingly, thus reducing the distance between the sound channels; conversely, if the accuracy is low, the distance between the sound channels will increase. The theoretical basis for setting the distance between the sound channels is that the distance between each sound channel is controlled to be less than the wavelength corresponding to the ultrasonic frequency. Sound channel 1. Preferably, the distance d1 between the centers of two adjacent sound channels 1 is set between 1mm and 100mm. It should be explained that the distance between two adjacent sound channels 1 here is... Figure 3 The distance between the longitudinal central axes of the two sound-emitting channels 1.

[0038] Furthermore, multiple sound-emitting channels 1 arranged along the second direction are defined to form a sound-emitting channel group 3, such as... Figure 6 As shown, the ultrasonic transducer array also includes one or more groups of sound-emitting channels 3 arranged along one or more second directions. The number and direction of the second directions are not limited. Preferably, there is one second direction, and the second direction is perpendicular to the first direction. In this way, the sound-emitting channels in one or more groups of sound-emitting channels 3 can be arranged in a square array along the X and Y axes, making the sound field move more uniformly. Of course, a reference point can also be selected in the first direction. The reference point and the first direction form a first reference line, and the reference point and the second direction form a second reference line. The angle between the first reference line and the second reference line is 0° to 360°, which can form an irregular arrangement of sound-emitting channels to adapt to different application scenarios. Correspondingly, the distance d2 between the centers of two adjacent sound-emitting channel groups 3 is also adapted to the movement accuracy of the moving sound field. The reason can be referred to the setting of the distance d1 between the centers of two adjacent sound-emitting channels 1, which will not be further explained here.

[0039] The arrangement of the ultrasonic transducers 2 within the ultrasonic transducer array is not limited; it can be arranged in a conventional square array, a circular array, or an irregular shape. Different arrangements adapt to different scenarios of sound channel 1 placement, making the parametric array loudspeaker more flexible. The number of sound channels 1 in each sound channel group 3 is adapted to the size of the ultrasonic transducer array in that direction and the movement accuracy of the moving sound field. The number of sound channels 1 is equal to the size of the ultrasonic transducer array in that direction divided by the distance between the centers of two adjacent sound channels 1. For example, if the ultrasonic frequency is 40kHz, the required movement accuracy of the moving sound field is 20mm, and the width of the ultrasonic transducer array in that direction is 0.2m, then the minimum number of sound channels 1 required is 10. Compared to the existing technology that uses multi-channel signal processing to adjust the phase of each channel, which requires at least 24 channels, this significantly reduces the number of sound channels, thereby effectively reducing system complexity and cost. Correspondingly, the size of the ultrasonic transducer array in any direction is adapted to the moving accuracy and sound pressure level requirements of the moving sound field. Typically, the size of the ultrasonic transducer array is between 0.1m and 0.5m.

[0040] like Figure 8 As shown, the present invention also proposes a sound field motion system, which can be applied, for example, in scenarios such as head tracking, including:

[0041] Location acquisition module 4 is used to acquire the location information of the target object. For example, a camera or ultrasonic positioning technology can be used to identify the location of the target object and transmit the location information of the target object to the control module;

[0042] The control module 5 is connected to the position acquisition module 4 and the ultrasonic transducer array. It is used to control the sound-emitting channel in the ultrasonic transducer array that corresponds to the position information of the target object to emit sound, while the other sound-emitting channels do not emit sound, so as to realize the movement of the sound field and its alignment with the target object.

[0043] In practice, the corresponding control modes can be pre-stored in the control module 5, and the corresponding control modes can be called according to the location information of the collected target object.

[0044] For example, in the specific embodiment above, the ultrasonic transducer array has a total of 6 sound transmission channels. The control module 5 has four pre-stored modes: Mode 1: sound transmission channels 1, 2, and 3 are on, and sound transmission channels 4, 5, and 6 are off; Mode 2: sound transmission channels 2, 3, and 4 are on, and sound transmission channels 1, 5, and 6 are off; Mode 3: sound transmission channels 3, 4, and 5 are on, and sound transmission channels 1, 2, and 6 are off; Mode 4: sound transmission channels 4, 5, and 6 are on, and sound transmission channels 1, 2, and 3 are off. When the target object approaches channels 1, 2, and 3, Mode 1 is activated; when the target object approaches channels 2, 3, and 4, Mode 2 is activated, and so on.

[0045] like Figure 7 and Figure 8 As shown, taking a head tracking scenario as an example, the location of the head is typically identified using a camera or ultrasonic positioning technology, and the location is transmitted to the control module 5. The corresponding sound channel is then controlled to emit sound. When the head moves, the location acquisition module 4 updates the target's position in real time, and the control module 5 controls the corresponding sound channel to emit sound while other sound channels remain silent, thus achieving sound field movement and alignment with the target. In implementation, the distance between the parametric array speaker and the head is preferably between 0.5m and 3m, ensuring good reception of the sound emitted by the parametric array speaker. The width of the sound channel 1 is preferably between 15cm and 30cm, matching the width of the head, thus reducing interference to other areas and providing point-to-point alerts. Furthermore, preferably, the entire parametric array speaker has a width of 300mm, with a total of 16 sound channels 1, and the distance between adjacent sound channels 1 is between 10mm and 100mm. This approach effectively controls cost, achieves optimal sound pressure levels, and provides good sound field movement accuracy.

[0046] It should be understood that the above description is for illustrative purposes and not for limitation. Many embodiments and applications beyond the provided examples will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of this teaching should not be determined by reference to the above description, but rather by reference to the foregoing claims and the full scope of their equivalents. For purposes of completeness, all articles and references, including patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended as a waiver of that subject matter, nor should it be construed as an indication that the applicant has not considered that subject matter as part of the disclosed inventive subject matter.

Claims

1. A parametric array loudspeaker, characterized in that, The system includes an ultrasonic transducer array, which includes multiple sound-emitting channels (1) spaced apart along a first direction. Each sound-emitting channel (1) includes multiple ultrasonic transducers (2) arranged in an array. Each sound-emitting channel (1) is independently controlled. The distance between the centers of two adjacent sound-emitting channels (1) is 1mm to 100mm. During operation, a moving sound field is formed by controlling some of the sound-emitting channels (1) to emit sound and others to not emit sound.

2. The parametric array loudspeaker according to claim 1, characterized in that, During operation, sound is emitted by a portion of the sound channels (1) that are set at continuous intervals among multiple sound channels (1), while the remaining sound channels (1) do not emit sound, in order to form a moving sound field.

3. The parametric array loudspeaker according to claim 1, characterized in that, The sound waves emitted by the partially emitting sound channel (1) at least cover the ears of the sound receiver.

4. The parametric array loudspeaker according to claim 1, characterized in that, The plurality of sound-emitting channels (1) spaced apart along the first direction form a sound-emitting channel group (3), and the ultrasonic transducer array includes one or more groups of sound-emitting channels (3) arranged along one or more second directions.

5. The parametric array loudspeaker according to claim 4, characterized in that, The distance between the centers of two adjacent sound channel groups (3) is 1mm to 100mm.

6. The parametric array loudspeaker according to claim 4, characterized in that, The first direction is perpendicular to the second direction.

7. The parametric array loudspeaker according to claim 4, characterized in that, The number of sound channels (1) in each group of sound channels (3) is equal to the size of the ultrasonic transducer array in that direction divided by the distance between the centers of two adjacent sound channels (1).

8. The parametric array loudspeaker according to claim 7, characterized in that, The size of the ultrasonic transducer array is 0.1m to 0.5m.

9. A sound field movement system, characterized in that, include: The location acquisition module (4) is used to acquire the location information of the target object; The control module (5) is connected to the position acquisition module (4) and the parametric array loudspeaker as described in any one of claims 1 to 8. It is used to control the sound-emitting channel in the ultrasonic transducer array corresponding to the position information to emit sound according to the position information of the target object, while the other sound-emitting channels do not emit sound, so as to form a moving sound field and be aligned with the target object.

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