KR102214788B1 - Beam forming member for controlling transmission direction of sound wave and sound wave control system of using the same - Google Patents

Abstract

Provided are a beam forming member for controlling transmission direction of a sound wave and a sound wave control system using the same. The beam forming member for controlling transmission direction of a sound wave includes a plate with a plurality of grooves arranged regularly, wherein at least some of the plurality of grooves have different depths, and in a plan view, the depths of the plurality of grooves are symmetrical in a first direction with respect to a certain center, and the depths of the plurality of grooves are configured to be asymmetrical in a second direction perpendicular to the first direction. According to the present invention, it is possible to achieve beam forming or beam steering of the sound wave intensively transmitted in a desired direction.

Description

A beam forming member for controlling the direction of sound wave transmission, and a sound wave control system using the same {BEAM FORMING MEMBER FOR CONTROLLING TRANSMISSION DIRECTION OF SOUND WAVE AND SOUND WAVE CONTROL SYSTEM OF USING THE SAME}

The present invention relates to controlling the transmission direction of sound waves. In detail, it relates to a beam forming member for controlling a sound wave transmission direction and a sound wave control system using the same.

In general, sound waves generated from a sound wave source such as an acoustic device have omnidirectionality and spread evenly in a 360-degree direction. Accordingly, as the distance from the sound wave source increases, the size of the sound wave rapidly decreases, and there is a problem in that it is difficult to deliver the sound of a desired size to a remote sound wave receiver, for example, a listener or a receiver such as a microphone.

In order to deliver a sound wave having a sufficient size to a receiver located at a distance, a method of increasing the size of the sound wave generated from the sound wave source may be considered. However, increasing the size of the sound wave in the sound wave source is limited and causes cost increase, and since the sound wave is spread evenly in all directions, there is a problem in that the sound wave is transmitted to a recipient other than the intended recipient. And from the perspective of the person who is not the intended recipient, sound waves are accepted as noise.

For this reason, research on a technology for intensively transmitting sound waves in a specific direction is being developed.

Korean Patent Publication No. 10-2018-0127226, Loudspeaker system and structure for controlling directionality and diffusion

As a method of controlling the transmission direction of the conventional sound wave, that is, to give directivity to the sound wave, a method of concentrating the transmission direction of the sound wave by placing a horn in front of the sound wave source or implementing it in a shape of a horn may be mentioned (Patent Document 1 ). The horn has an approximately funnel shape, and by using the characteristic that sound waves are reflected from the inner wall of the horn, it is possible to give approximate directivity to sound waves. Examples of the horn applied include a loudspeaker. However, it is accepted that there is a limit in the field of technology to transmit sound waves more efficiently because the directivity is not very high when the horn is used, and the loss rate of sound waves is particularly large.

In addition, there is a method of applying reinforcement and cancellation of sound waves using a plurality of sound wave sources, but this is difficult to see as giving directivity to sound waves in a strict sense, and there is a problem that the sound wave control system is enlarged and thus inefficient. In addition, in an atypical situation, that is, it is not possible to intensively transmit sound waves in a desired direction as needed, and there is a limit that can be controlled only under a predesigned situation.

Accordingly, an object to be solved by the present invention is to provide a beam forming member for controlling a sound wave transmission direction capable of intensively transmitting sound waves generated from a sound wave source in a desired direction.

Another problem to be solved by the present invention is to provide a sound wave control system capable of controlling a sound wave transmission direction by giving directivity to sound waves.

Another problem to be solved by the present invention is to provide a method of controlling a sound wave generated from a sound wave source in a desired direction.

The problems of the present invention are not limited to the technical problems mentioned above, and other technical problems that are not mentioned will be clearly understood by those skilled in the art from the following description.

A sound wave beam forming member according to an embodiment of the present invention for solving the above problem is a sound wave beam forming member including a plate in which a plurality of grooves are regularly arranged, at least some of the plurality of grooves have different depths, In a plan view, the depths of the plurality of grooves are configured to be symmetrical in a first direction based on a certain center, and the depths of the plurality of grooves are configured to be asymmetrical in a second direction perpendicular to the first direction.

In a plan view, the repeating units of the plurality of grooves may be hexagonally arranged.

Here, the arrangement pitch between adjacent grooves may be 1.4 times or more and 2 times or less of the maximum width of the grooves.

In addition, the maximum width of the groove may be smaller than the wavelength of the sound wave to be controlled.

The frequency of the sound wave to be controlled is 1 kHz to 30 kHz, and the maximum depth of the plurality of grooves may be in the range of 1.5 to 1.7 times the maximum width of the groove.

In addition, the minimum depth of the plurality of grooves may be in the range of 0.5 to 0.6 times the maximum width of the groove.

In addition, the maximum thickness of the plate may be in the range of 2 to 3.5 times the maximum width of the groove.

In the cross section of the plate cut in the second direction, grooves having a maximum depth may be defined as first grooves, and grooves having a minimum depth may be defined as second grooves.

Here, the first grooves may be spaced apart from each other and repeatedly arranged along the second direction, and the second grooves may be spaced apart from each other and repeatedly arranged along the second direction.

In addition, at least one second groove is located between the two first grooves spaced apart in the second direction and adjacent to each other, and at least one first groove is disposed between the two second grooves spaced apart in the second direction and adjacent to each other. This can be located.

The first grooves include a 1-1 groove, a 1-2 groove located on one side of the first-first groove in the second direction, and a 1-3 groove located on the other side of the first-first groove in the second direction. It may include a groove.

In this case, the minimum separation distance between the 1-1 groove and the 1-2 groove may be greater than the minimum separation distance between the 1-1 groove and the 1-3 groove.

In addition, the first grooves further include a 1-4 groove located on one side of the 1-2 groove in the second direction, and a 1-5 groove located on the other side of the first-3 groove in the second direction. can do.

In this case, the minimum separation distance between the 1-2 groove and the 1-4 groove may be greater than the minimum separation distance between the 1-1 groove and the 1-2 groove.

In addition, a minimum separation distance between the 1-3 grooves and the 1-5 grooves may be greater than a minimum separation distance between the 1-1 groove and the 1-3 groove.

In some embodiments, the second grooves are 2-1 grooves, a 2-2 groove located at one side of the 2-1 groove in the second direction, and the second groove at the other side of the 2-1 groove. And a 2-4 groove located on one side of the second direction of the 2-2 groove, and a 2-5 groove located on the other side of the second direction of the 2-3 groove. I can.

Here, the minimum separation distance between the 2-1 groove and the 2-2 groove may be greater than the minimum separation distance between the 2-1 groove and the 2-3rd groove.

In addition, a minimum separation distance between the 2-2 groove and the 2-4 groove may be greater than a minimum separation distance between the 2-1 groove and the 2-2 groove.

In addition, a minimum separation distance between the 2-3rd groove and the 2-5th groove may be greater than a minimum separation distance between the 2-1 groove and the 2-3rd groove.

In some embodiments, the base surface of the first-second groove may form an inclined surface inclined upward toward one side in the second direction, and the base surface of the first-third groove may not form a slope.

Further, at least a portion of the base surface of the second groove may form an inclined surface.

In this case, an inclination angle of the base surface of the 1-2 groove may be greater than an inclination angle of the base surface of the second groove.

Among the defined first grooves, a separation distance between the two first grooves closest to each other is defined as a first separation distance, and among the defined second grooves, a separation distance between two second grooves closest to each other is second It can be defined as the separation distance.

In this case, the first separation distance and the second separation distance may be gradually increased from the center portion to the edge portion of the sound wave beam forming member, respectively.

Further, the sound wave forming member may impart directivity so that the sound wave incident in the thickness direction of the plate is inclined toward the second direction side.

A sound wave beam forming member according to another embodiment of the present invention for solving the above problem is a sound wave beam forming member including a plate in which a plurality of grooves are regularly arranged, at least some of the plurality of grooves have different depths, At least some of them have the same depth, but the relationship between the depth d of a groove and the position on the plane (x, y) is configured to satisfy the following equation.

[Equation]

Here, A ₁ , A ₂ , A ₃ , A ₄ , A ₅ and A ₆ are positive numbers each having a predetermined value, B is a positive number between 0.8 and 1.5, M is a positive number between 0.5 and 0.7, λ Is the wavelength of the sound wave to be modulated, n is a positive number between 1.3 and 1.5, θ is the angle to be refracted, d is the depth of the groove, and x and y are each first based on an arbitrary center. It is a direction and a coordinate value in a second direction perpendicular to the first direction.

The sound wave forming member may impart directivity so that the sound wave incident in the thickness direction of the plate is inclined toward the one direction side.

A sound wave control system according to an embodiment of the present invention for solving the above other problems includes a sound wave source; And a sound wave beam forming member. Here, the sound wave beam forming member may be according to the present invention.

The sound wave beam forming member may have one surface on which the groove is formed and the other flat surface, and the sound wave beam forming member may be disposed such that the other surface faces the sound wave source.

Details of other embodiments are included in the detailed description.

According to embodiments of the present invention, using a beam forming member having a plurality of grooves but having a surface admittance controlled using the depth of the grooves, sound wave forming or beam steering intensively transmitted in a desired direction (steering) can be achieved.

Through this, directivity is given to sound waves generated from a sound wave source to function like a sound wave antenna, and transmission of sound waves to a long distance may be possible without substantial loss of sound waves compared to the prior art. In addition, compared to the conventional acoustic control device and control system, it can be more efficiently, particularly downsized, leading to a promising application in the field of sound wave control.

Effects according to the embodiments of the present invention are not limited by the contents illustrated above, and more various effects are included in the present specification.

1 is a perspective view of a sound wave beam forming member according to an embodiment of the present invention.
2 is a layout showing a groove arrangement of the sound wave beam forming member of FIG. 1.
3 is a cross-sectional perspective view taken along line III-III' of FIG. 1.
4 is a cross-sectional view of FIG. 3.
5 is a cross-sectional perspective view taken along line V-V' of FIG. 1.
6 is a cross-sectional view of FIG. 5.
7 is a diagram showing a surface admittance contour line of the sound wave beam forming member of FIG. 1.
8 is a cross-sectional view of a sound wave beam forming member according to another embodiment of the present invention.
9 is a cross-sectional view of an acoustic beam forming member according to another embodiment of the present invention.
10 is a cross-sectional view of a sound wave beam forming member according to another embodiment of the present invention.
11 and 12 are schematic diagrams showing a sound wave control system according to an embodiment of the present invention.
13 to 15 are schematic diagrams showing a sound wave control system according to another embodiment of the present invention.
16 and 17 are schematic diagrams showing a sound wave control system according to another embodiment of the present invention.
18 is a schematic diagram showing a sound wave control system according to another embodiment of the present invention.
19 to 21 are images showing planar surface admittance patterns of sound wave beam forming members according to Examples 1, 2, and 3, respectively.
22 to 24 are images obtained by simulating sound pressure levels in the sound wave control systems according to the first, second and third embodiments, respectively.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms different from each other, and only the embodiments make the disclosure of the present invention complete, and those skilled in the art to which the present invention pertains. It is provided to fully inform the person of the scope of the invention, and the invention is only defined by the scope of the claims. That is, various changes may be made to the embodiments suggested by the present invention. The embodiments described below are not intended to be limited to the embodiments, and should be understood to include all changes, equivalents, and substitutes thereto.

The size, thickness, width, length, etc. of the components shown in the drawings may be exaggerated or reduced for convenience and clarity of description, so the present invention is not limited to the illustrated form.

Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used as meanings that can be commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in a commonly used dictionary are not interpreted ideally or excessively unless explicitly defined specifically.

Spatially relative terms such as'above','upper','on','below','beneath', and'lower' are As shown, it may be used to easily describe the correlation between one device or components and other devices or components. Spatially relative terms should be understood as terms including different directions of the device when used in addition to the directions shown in the drawings. For example, when an element shown in the figure is turned over, an element described as'below or beneath' another element may be placed'above' another element. Therefore, the exemplary term'below' may include both the lower and upper directions.

As used herein,'most adjacent' means the closest or closest among a plurality of elements in the case of repeated arrangements. For example, when there is no component that can be classified or referred to as being substantially the same as the component between a plurality of adjacent components, the plurality of components are closest to each other.

In this specification,'and/or' includes each and every combination of one or more of the recited items. In addition, the singular form also includes the plural form unless otherwise stated in the text. As used herein,'comprises' and/or'comprising' does not exclude the presence or addition of one or more other elements other than the mentioned elements. Numerical ranges indicated using'to' represent numerical ranges including the values listed before and after them as lower and upper limits, respectively. "About" or "approximately" means a value or numerical range within 20% of the value or numerical range described thereafter.

In addition, in the present specification, the first direction (X) refers to an arbitrary direction in the plane, and the second direction (Y) refers to another direction in the plane that intersects the first direction (X). In addition, the third direction Z means a direction perpendicular to the plane. Here, the second direction Y is meant to include one side Y1 in the second direction toward one direction and the other side Y2 in the second direction toward the opposite direction. Unless otherwise defined, a'plane' means a plane to which the first direction X and the second direction Y belong. Further, unless otherwise defined, "overlapping" means overlapping in the third direction (Z) from the plane viewpoint.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view of a sound wave beam forming member 11 according to an embodiment of the present invention. 2 is a layout showing the arrangement of the grooves 200 of the sound wave beam forming member 11 of FIG. 1.

1 and 2, the sound wave beam forming member 11 according to the present embodiment includes a plate 101 having a groove formed on one surface thereof. 1 illustrates a case in which the plate 101 has a circular shape in a plane, but the present invention is not limited thereto, and the plate 101 may have an elliptical shape in a plane or an eccentric ellipse shape. In addition, the plate 101 may have a polygonal shape such as a rectangular shape on a plane.

A groove 200 may be provided on an upper surface (one surface) of the plate 101. The groove 200 may form a surface admittance distribution of the plate 101. The groove 200 may be recessed from the top side to the other side to form a predetermined depth. Although not shown in the drawings, the rear surface (the other surface) of the plate 101 may be in a flat state. Hereinafter, the shape and arrangement of the groove 200 will be described.

In an exemplary embodiment, the grooves 200 may have a regular arrangement on a plane to which the first direction X and the second direction Y belong. For example, the grooves 200 may be repeatedly arranged along a first direction X, and the grooves 200 may be repeatedly arranged along a diagonal direction in which the first direction X and the second direction Y intersect. An angle formed by the first direction X and the diagonal direction may be about 60 degrees. That is, the plurality of grooves 200 are regularly arranged, but the repeating unit of the grooves 200 may have a hexagonal arrangement. More specifically, the center of the groove 200 may be located at a position corresponding to each vertex of the regular hexagon, and the center of the groove 200 may be located at a position corresponding to the center point of the regular hexagon. Accordingly, when the centers of the three grooves 200 closest to each other are connected, an equilateral triangle may be formed.

In a plan view, the groove 200 may have a circular shape. However, the present invention is not limited thereto, and the groove 200 may have a shape that is easy to form a regular arrangement by forming a repeating unit. For example, the groove 200 may have a square shape, a hexagonal shape, or the like.

As will be described later, the groove 200 is designed to have a specific maximum width (W), a separation distance (D), an arrangement pitch (P), a depth (not shown), and the like, so as to impart directivity to a sound wave. The maximum width (W) of the groove 200 is about 1.5 times or less, or about 1.4 times or less, or about 1.3 times or less, or about 1.2 times or less, or about 1.1 times or less of the wavelength of the sound wave to be controlled, or It may be less than or equal to the wavelength of the sound wave. Preferably, the maximum width W is preferably smaller than the wavelength of the sound wave to be controlled in terms of gain, but the present invention is not necessarily limited thereto. On the other hand, when the maximum width W exceeds 1.5 times the wavelength, it may not function as a wave modulation structure. For example, the maximum width W may be about 1.3 mm to 1.5 mm, or about 1.4 mm. Here, when the groove 200 is circular in plan, the maximum width W may be expressed as the diameter of the circle.

In particular, when the sound wave to be controlled is an audible frequency having a frequency in the range of 1 kHz to 30 kHz, the range of the maximum width W is preferable. In some embodiments, the sound wave to be controlled may be about 10 kHz to 30 kHz, or about 15 kHz to 25 kHz, or about 20 kHz.

In addition, the arrangement pitch P between the two grooves 200 closest to each other may be about 1.4 times or more and 2 times or less of the maximum width W. For example, the arrangement pitch P may be about 1.8 mm to about 2.8 mm, or about 1.9 mm to about 2.5 mm, or about 2.0 mm. Here, the arrangement pitch P may be expressed as a distance between the centers of the groove 200 on the plane. The arrangement pitch P may also be smaller than the wavelength of the sound wave to be controlled.

In addition, the separation distance D between the two adjacent grooves 200 may be expressed as a length excluding the maximum width W from the arrangement pitch P. That is, the separation distance D may be about 0.5mm to 1.3mm, or about 0.4mm to 1.0mm, or about 0.6mm, but the present invention is not limited thereto.

As in this embodiment, the plurality of grooves 200 having a maximum width W, an arrangement pitch P, a depth, etc. may have a repetitive and regular structure so that the plate 101 functions like a meta material. In the present specification, the term'meta material' or'meta structure' is meant to include artificial materials, structures, structures, and systems for implementing properties different from those of naturally occurring atoms or molecules. The characteristics include permittivity, permeability, refractive index, and scattering parameter. In particular, various studies are being conducted on metamaterials to control energy having wave characteristics such as light, electromagnetic waves, and sound waves.

FIG. 1 illustrates a case in which hundreds of grooves 200 are formed in the plate 101 for convenience of expression, but the present invention is not limited thereto. In another embodiment, the plate 101 has thousands of levels of grooves 200, tens of thousands of levels of grooves 200, hundreds of thousands of levels of grooves 200, or millions of levels It may have a groove 200 of.

Hereinafter, the depth of the groove 200 will be described with further reference to FIGS. 3 to 7.

3 is a cross-sectional perspective view taken along line III-III' of FIG. 1. 4 is a cross-sectional view of FIG. 3, which is a cross-sectional view of the plate 101 taken along a first direction X. 5 is a cross-sectional perspective view taken along line V-V' of FIG. 1. FIG. 6 is a cross-sectional view of FIG. 5, which is a cross-sectional view of the plate 101 taken along the second direction Y. 7 is a diagram showing a surface admittance contour line of the sound wave beam forming member 11 of FIG. 1.

3 to 7, at least some of the grooves 200 of the plate 101 of the sound wave beam forming member 11 according to the present embodiment have different depths, and at least some of the grooves 200 are substantially Can have the same depth. The grooves 200 may have inner walls in a direction perpendicular to the plane, that is, in the third direction Z.

First, as shown in FIGS. 3 and 4, in the cross section of the plate 101 cut in the first direction (X), the plurality of grooves 200 are at least one first groove 210 and at least one second Includes a groove 220. The first groove 210 is defined as a groove having a maximum depth in a cross section cut in the first direction (X), and the second groove 220 is a groove having a minimum depth in a cross section cut in the first direction (X). Is defined as

In addition, the depths of the plurality of grooves 200 may be configured to be symmetrical in the first direction X. In the present specification, "symmetrical in one direction" means that a structure located at one side in one direction and a structure located at the other side in one direction are symmetrical around a virtual center line perpendicular to the one direction.

That is, as illustrated in FIG. 4, when the center of the plate 101 in the first direction (X) approximately coincides with the point where the sound wave is generated, the first groove 210 is located at a position corresponding to the center, Based on a corresponding position, one side of the first direction X (right side in the drawing) and the other side of the first direction X (left side in the drawing) may have substantially the same structure.

The depth T ₁ of the first groove 210, that is, the maximum depth T ₁ of the groove 200 may be about 1.5 to 1.7 times, or about 1.6 times the maximum width W. For example, the depth T ₁ of the first groove 210 may be in the range of about 1.9mm to 2.3mm, or about 2.0mm to 2.2mm. The first grooves 210 may be spaced apart from each other and may be repeatedly arranged along the first direction X. In addition, at least one second groove 220 may be positioned between the two first grooves 210 that are spaced apart in the first direction X and adjacent to each other.

In addition, the depth T ₂ of the second groove 220, that is, the minimum depth T ₂ of the groove 200 may be about 0.5 to 0.6 times the maximum width W. For example, the depth T ₂ of the second groove 220 may be in a range of about 0.7 mm to 0.8 mm. The second grooves 220 may be spaced apart from each other and may be repeatedly arranged along the first direction X. In addition, at least one first groove 210 may be positioned between the two second grooves 220 that are spaced apart in the first direction X and adjacent to each other.

One or more third grooves having a depth smaller than the first groove 210 and a greater depth than the second groove 220 may be located between the first groove 210 and the second groove 220 which are closest to each other. . Accordingly, in the cross section cut along the first direction X, the plurality of grooves 200 may have a depth in which the increase or decrease is repeated.

Sound waves can be classified as elastic waves in which energy is transmitted due to changes in the disturbing state of the medium within the medium. That is, energy can be transferred through the medium of sound waves. In general, sound waves have omni-directional properties and can evenly spread in a 360-degree direction from the source. In the case where the grooves 200 regularly arranged with a predetermined depth as in this embodiment are provided, the upper surface of the plate 101 may have a predetermined sinusoidal modulated admittance, and proceeds along the upper surface of the plate 101. A surface wave or a leaky wave is converted into a field wave by the modulated admittance surface to be refracted in a specific direction and maintain high gain.

For the intended sinusoidal modulated surface admittance design for a sound wave having a predetermined wavelength λ, the surface admittance of the upper surface of the plate 101 must be continuously changed in a range of about 0.2 to 1.8. To this end, it is possible to achieve this by configuring the depths T ₁ and T _{2 of the first} and second grooves 210 and 220 as described above.

As in the present embodiment, the sound wave beam forming member 11 including the plate 101 having a symmetrical structure in the first direction X does not substantially form a radiation wave refracted toward the first direction X, or At least, as will be described later, only a lesser level of radiation may be formed than the radiation wave refracted toward the second direction Y.

Next, as shown in FIGS. 5 and 6, in a cross section in which the plate 101 is cut in the second direction (Y), the plurality of grooves 200 may include one or more first grooves 210 and one or more first grooves. It includes 2 grooves 220. The first groove 210 is defined as a groove having a maximum depth in a cross section cut in the second direction (Y), and the second groove 220 is a groove having a minimum depth in a cross section cut in the second direction (Y). Is defined as The first groove 210 of the cross-section cut in the second direction (Y) has substantially the same depth as the first groove 210 of the cross-section cut in the first direction (X), and in the second direction (Y). The second groove 220 of the cut-out cross section may have substantially the same depth as the second groove 220 of the cut-out cross-section in the first direction (X), but the present invention is not limited thereto.

The depth T ₁ of the first groove 210, that is, the maximum depth T ₁ of the groove 200 may be about 1.5 to 1.7 times, or about 1.6 times the maximum width W. For example, the depth T ₁ of the first groove 210 may be in the range of about 1.9mm to 2.3mm, or about 2.0mm to 2.2mm. The first grooves 210 may be spaced apart from each other and may be repeatedly arranged along the second direction Y. In addition, at least one second groove 220 may be positioned between the two first grooves 210 that are spaced apart in the second direction Y and adjacent to each other.

In addition, the depth T ₂ of the second groove 220, that is, the minimum depth T ₂ of the groove 200 may be about 0.5 to 0.6 times the maximum width W. For example, the depth T ₂ of the second groove 220 may be in a range of about 0.7 mm to 0.8 mm. The second grooves 220 may be spaced apart from each other and may be repeatedly arranged along the second direction Y. In addition, at least one first groove 210 may be positioned between the two second grooves 220 that are spaced apart in the second direction Y and adjacent to each other.

One or more third grooves having a depth smaller than the first groove 210 and a greater depth than the second groove 220 may be located between the first groove 210 and the second groove 220 which are closest to each other. . Accordingly, in a cross section cut along the second direction Y, the plurality of grooves 200 may have a depth in which the increase or decrease is repeated. In some embodiments, the third groove may be located on one side Y1 in the second direction of the center, but may not be located on the other side Y2 in the second direction.

In addition, the depths of the plurality of grooves 200 may be configured to be asymmetric in the second direction Y.

In an exemplary embodiment, the first grooves 210 include the 1-1 groove 211, the 1-2 groove 212, and the 1-3 groove 213, and the 1-4 groove 214 ) May be further included.

The 1-1st groove 211 may be a groove whose center substantially coincides with a point of sound wave generation. That is, it may be a groove located in the center of the plate 101, but the present invention is not limited thereto, and if the groove is a reference in the position of the 1-2 grooves 212 to 1-4 grooves 214 to be described later It's okay.

The 1-2th groove 212 may be a groove located on one side Y1 in the second direction of the 1-1st groove 211. For example, the 1-2nd groove 212 is spaced apart from one side (Y1) in the second direction of the 1-1 groove 211, and the first groove 210 closest to the 1-1 groove 211 ) Can be. Further, the 1-3th groove 213 may be a groove located on the other side Y2 in the second direction of the 1-1st groove 211. For example, the 1-3th groove 213 is spaced apart from the other side Y2 in the second direction of the 1-1 groove 211, and the first groove 210 closest to the 1-1 groove 211 ) Can be.

In this case, the minimum separation distance L ₁₂ between the 1-1 groove 211 and the 1-2 groove 212 is the minimum separation distance between the 1-1 groove 211 and the 1-3 groove 213 It may be greater than the distance L ₁₃ .

Likewise, although not indicated by reference numerals, the second groove 220 is a 2-1 groove, a 2-2 groove located on one side Y1 in the second direction of the 2-1 groove, and a second groove of the 2-1 groove. It includes a 2-3rd groove located on the other side (Y2) in the direction, and the minimum separation distance between the 2-1 groove and the 2-2 groove is greater than the minimum separation distance between the 2-1 groove and the 2-3rd groove. I can. Here, the 2-2 groove may be the second groove 220 closest to the 2-1 groove, and the 2-3 groove may be the second groove 220 closest to the 2-1 groove.

In addition, the 1-4th groove 214 may be a groove located on one side Y1 of the 1-2nd groove 212 in the second direction. For example, the 1-4 groove 214 is spaced apart from one side (Y1) in the second direction of the 1-2 groove 212, and the first groove 210 closest to the 1-2 groove 212 ) Can be.

In this case, the minimum separation distance L ₂₄ between the 1-2 groove 212 and the 1-4 groove 214 is the minimum separation between the 1-1 groove 211 and the 1-2 groove 212 It may be greater than the distance L ₁₂ .

Likewise, although not indicated by reference numerals, the second groove 220 may further include a 2-4 groove located on one side Y1 in the second direction of the 2-2 groove. Here, the 2-4 groove may be the second groove 220 closest to the 2-2 groove, but the present invention is not limited thereto. Further, the minimum separation distance between the 2-2 groove and the 2-4 groove may be greater than the minimum separation distance between the 2-1 groove and the 2-2 groove.

That is, in the cross section of the plate 101 cut along the second direction (Y), the plurality of grooves 200 include a plurality of first grooves 210 and a plurality of second grooves 220, and the increase or decrease is repeated. However, an approximate repetition period to one side Y1 in the second direction may be larger than an approximate repetition period to the other side Y2 in the second direction.

In other words, in the cross section of the plate 101 cut in the second direction (Y), the separation distance between the two first grooves 210 closest to each other among the first grooves 210 is the first separation distance. In the case where the separation distance between the two second grooves 220 closest to each other among the second grooves 220 is defined as the second separation distance, the first separation distance and the second separation distance are respectively plate The sound wave beam forming member 11 including 101 may have a tendency to gradually increase from the center portion to the edge portion.

Furthermore, the first separation distance and the second separation distance gradually increase in the direction of one side Y1 in the second direction, but do not change in the direction of the other side Y2 in the second direction, and a substantially regular arrangement and separation distance may be maintained.

As described above, when the grooves 200 regularly arranged with a predetermined depth are provided, the upper surface of the plate 101 may have a predetermined sinusoidal modulated admittance. In addition, the surface wave traveling along the upper surface of the plate 101 may be refracted in a specific direction by the modulated admittance surface.

As in the present embodiment, the sound wave beam forming member 11 including the plate 101 having an asymmetric structure in the second direction Y may form a radiation wave refracted toward the second direction Y. In particular, a radiation wave inclined toward one side Y1 in the second direction with respect to a normal direction (ie, a third direction Z) with respect to a plane to which the first direction X and the second direction Y belong may be formed. . Accordingly, sound waves incident and traveling in the third direction Z, which is the thickness direction of the plate 101, may be refracted to one side Y1 in the second direction to form a directivity sound wave beam.

To this end, the thickness T of the plate 101 in the third direction Z may have a predetermined relationship with the maximum width W and the depths T ₁ and T ₂ of the groove 200. In an exemplary embodiment, the maximum thickness (T) of the plate 101 is about 2 to 3.5 times, or about 2 to 3 times, or about 2 to 2.5 times the maximum width (W) of the groove 200 Can be in range. Accordingly, the remaining thickness (T ₃ ) in which the groove 200 does not penetrate the plate 101 is about 0.3 to 2 times, or about 0.3 to 1.5 times, or about 0.3 to 1 times of the maximum width (W). Can be in range. In particular, when the maximum width (W) of the groove is in the range of about 1.3mm to 1.5mm, the remaining thickness (T ₃ ) may be in the range of about 0.45mm to 2.0mm, or about 0.45mm to 1.5mm. If the residual thickness T ₃ is too large, the size of the surface wave increases, so that the directivity imparting efficiency decreases, and the size of the radiation wave traveling to an unintended position may increase. On the other hand, if the remaining thickness T ₃ is too small, the directivity imparting efficiency may be lowered, and the magnitude of the sound wave traveling in the third direction Z may increase.

In the sound wave beam forming member 11 according to the present embodiment, a contour line of a surface admittance value is defined based on an arbitrary center as shown in FIG. 7, but the contour line may be approximately elliptical or eccentric elliptical or oval. . That is, the contour line may have a closed curve shape rather than a completely circular shape. For example, a position represented by a solid line in FIG. 7 may be a contour line of a maximum surface admittance value, and a position represented by a dotted line may be a contour line of a minimum surface admittance value.

In addition, the surface admittance contour line of a predetermined value may be repeated in the radial direction based on the center point. In addition, the approximate repetition period in the radial direction of the surface admittance contour line having a predetermined value may have a tendency to gradually increase from the center portion to the edge portion of the sound wave beam forming member 11.

In an exemplary embodiment, the surface admittance of the upper surface of the plate 101 of the sound wave beam forming member 11 is formed through Equation 1 below, and the admittance may be controlled through the depth of the groove 200 at the corresponding position. The surface admittance value and the depth of the groove 200 may be proportional. In other words, the contour line of the admittance value represented in FIG. 7 may approximately coincide with the contour line regarding the depth of the groove.

[Equation 1]

Here, the left side is a function of the depth of the groove 200, and the right side is a function of the position of the groove 200 on a plane.

In addition, the left side of Equation 1 may be expressed by Equation 2 below.

[Equation 2]

Here, A ₁ , A ₂ , A ₃ , A ₄ , A _5, and A ₆ are positive constants each having a predetermined value. For example, A ₁ is a positive number between 5 and 6, A ₂ is a positive number between 20 and 25, A ₃ is a positive number between 25 and 30, A ₄ is a positive number between 20 and 25, A ₅ Is a positive number between 6 and 8, and A ₆ may be a positive number between 0 and 1. Also, d is the depth of the groove.

In Equation 2, properties related to the medium such as the density of the plate 101 and/or the thickness T of the plate 101 may be reflected.

In addition, the right side of Equation 1 may be expressed by Equation 3 below.

[Equation 3]

Here, B is an average surface admittance constant, which is a positive number between 0.8 and 1.5, and M is a modulation constant and is a positive number between 0.5 and 0.7. In addition, λ is the wavelength (m) of the sound wave to be modulated, n is a positive number between 1.3 and 1.5, θ is the angle to be refracted, and is the angle to the normal direction of the sound wave beam forming member. In addition, x and y are coordinate values m using the center point of the sound wave beam forming member as the origin at a plane viewpoint, and are positive or negative values, respectively. For example, coordinates spaced from the origin in the first direction (X) in one side (right as in FIG. 4) have a positive x value, and coordinates in the first direction (X) in the other side (as in FIG. 4) are negative. It can have x value of. In addition, a coordinate spaced apart from the origin to one side Y1 in the second direction may have a positive y value, and a coordinate spaced apart from the origin to the other side Y2 may have a negative y value.

In Equation 3, properties related to the medium such as the density of the plate 101 and/or the thickness T of the plate 101 may be reflected.

By matching Equation 2 and Equation 3, the depth of the groove at a specific coordinate can be derived, and based on this, an admittance contour line and a contour line related to the depth of the groove as shown in FIG. 7 can be derived.

The sound wave beam forming member 11 including the plate 101 according to the present embodiment may be implemented in various forms such as a super-directional speaker, a long-range ultrasonic sensor, an acoustic microfluidic device, and a sonar, but the present invention is limited thereto. It is not.

Hereinafter, a sound wave beam forming member according to another embodiment of the present invention will be described. However, a description of the same or similar configuration as the sound wave beam forming member 11 according to the above-described embodiment will be omitted, and this will be clearly understood by those of ordinary skill in the art from the accompanying drawings.

8 is a cross-sectional view of the sound wave beam forming member 12 according to another embodiment of the present invention, and is a cross-sectional view of the plate 102 of the sound wave beam forming member 12 cut along the second direction Y.

Referring to FIG. 8, the plate 102 of the sound wave beam forming member 12 according to the present embodiment is at the center when the center of the plate 102 in the second direction (Y) substantially coincides with the point of generation of the sound wave. The point in which the second groove 220 rather than the first groove 210 is positioned at a corresponding position is different from the sound wave beam forming member 11 according to the exemplary embodiment of FIG. 1 and the like.

That is, in the cross-sectional view of the plate 102 cut in the second direction (Y), a first groove 210 having a maximum depth and a second groove 220 having a minimum depth are defined, and the first groove 210 and Each of the second grooves 220 may be repeatedly arranged along the second direction Y. In this case, the second groove 220 may be located at a position corresponding to the center.

In addition, in one side (Y1) in the second direction, the first separation distance between the first grooves 210 closest to each other and the second separation distance between the second grooves 220 closest to each other may have a tendency to gradually increase. have. On the other hand, on the other side Y2 in the second direction, the first separation distance between the first grooves 210 closest to each other and the second separation distance between the second grooves 220 closest to each other may be substantially the same. Accordingly, the depths of the grooves 210 and 220 may have an asymmetric structure along the second direction Y.

On the other hand, the cross-sectional view of the plate 102 cut along the first direction X is not shown, but the depth of the grooves 210 and 220 along the first direction X is the same as described above. Therefore, redundant descriptions are omitted.

9 is a cross-sectional view of the acoustic beam forming member 13 according to another embodiment of the present invention, a cross-sectional view of the plate 103 of the acoustic beam forming member 13 cut along the second direction Y.

Referring to FIG. 9, in a cross-sectional view cut in the second direction (Y), in the other side (Y2) in the second direction, a first separation distance between the first grooves 210 that are closest to each other and a second groove that is closest to each other The point that the second separation distance between the 220 is gradually increased is different from the sound wave beam forming member 11 according to the exemplary embodiment of FIG. 1 and the like.

In the cross-sectional view of the plate 103 cut in the second direction (Y), a first groove 210 having a maximum depth and a second groove 220 having a minimum depth are defined, and the first groove 210 and the second groove Each of the grooves 220 may be repeatedly arranged along the second direction Y. In this case, the first groove 210 may be located at a position corresponding to the center, but the present invention is not limited thereto, and the second groove 220 may be located in another embodiment. In addition, one or more third grooves having a depth smaller than the first groove 210 and a greater depth than the second groove 220 may be located between the first groove 210 and the second groove 220 that are closest to each other. May be. Accordingly, in a cross section cut along the second direction Y, the plurality of grooves 210 and 220 may have a depth in which the increase or decrease is repeated. In addition, the depths of the plurality of grooves 210 and 220 may be configured to be asymmetric in the second direction Y.

In an exemplary embodiment, the first grooves 210 include the 1-1 groove 211, the 1-2 groove 212, the 1-3 groove 213 and the 1-4 groove 214 And, it may further include a 1-5th groove 215.

Here, the minimum separation distance L ₁₂ between the 1-1 groove 211 and the 1-2 groove 212 is the minimum separation distance between the 1-1 groove 211 and the 1-3 groove 213 May be greater than (L ₁₃ ). In addition, the minimum separation distance L ₂₄ between the 1-2 groove 212 and the 1-4 groove 214 is the minimum separation between the 1-1 groove 211 and the 1-2 groove 212 It may be greater than the distance L ₁₂ . Since the 1-1 groove 211 to the 1-4 groove 214 have been described above with reference to FIGS. 5 and 6, overlapping descriptions will be omitted.

The 1-5th groove 215 may be a groove located on the other side Y2 in the second direction of the 1-3th groove 213. For example, the 1-5 groove 215 is spaced apart from the other side (Y2) in the second direction of the 1-3 groove 213, and the first groove 210 closest to the 1-3 groove 213 ) Can be.

In this case, the minimum separation distance L ₃₅ between the 1-3 groove 213 and the 1-3 groove 215 is between the 1-1 groove 211 and the 1-3 groove 213 A point greater than the minimum separation distance L ₁₃ is different from the sound wave beam forming member 11 according to the embodiment of FIG. 1 and the like.

In addition, the minimum separation distance L ₂₄ between the 1-2 groove 212 and the 1-4 groove 214 is the minimum separation distance between the 1-3 groove 213 and the 1-5 groove 215 It may be greater than (L ₃₅ ).

Likewise, although not represented by reference numerals, the second groove 220 includes a 2-1 groove, a 2-2 groove, a 2-3 groove, and a 2-4 groove, and further includes a 2-5 groove. Can include. The 2-5th groove may be a second groove 220 closest to the 2-3rd groove and the other side Y2 in the second direction.

Here, the minimum separation distance between the 2-1 groove and the 2-2 groove is greater than the minimum separation distance between the 2-1 groove and the 2-3 groove, and the minimum distance between the 2-2 groove and the 2-4 groove The separation distance may be greater than the minimum separation distance between the 2-1 groove and the 2-2 groove.

In addition, the minimum separation distance between the 2-3rd groove and the 2-5 groove is greater than the minimum separation distance between the 2-1 groove and the 2-3rd groove, and between the 2-2 groove and the 2-4 groove The minimum separation distance may be greater than the minimum separation distance between the 2-3rd groove and the 2-5th groove.

That is, in the cross section of the plate 103 cut along the second direction (Y), the plurality of grooves 210 and 220 increase or decrease, including the plurality of first grooves 210 and the plurality of second grooves 220 This repetition depth is formed, but an approximate repetition period toward one side Y1 in the second direction may be greater than an approximate repetition period toward the other side Y2 in the second direction.

In other words, in the first separation distance and the second separation distance defined above, the first separation distance and the second separation distance are respectively from the center of the sound wave beam forming member 13 including the plate 103 toward the edge. It may have a tendency to grow gradually.

Furthermore, the first separation distance and the second separation distance may gradually increase in the direction of one side Y1 in the second direction and the other side Y2 in the second direction, respectively.

On the other hand, the cross-sectional view of the plate 103 cut along the first direction X is not represented, but the depth of the grooves 210 and 220 along the first direction X has a symmetrical structure as described above. Therefore, redundant descriptions are omitted.

10 is a cross-sectional view of the sound wave beam forming member 14 according to another embodiment of the present invention, and is a cross-sectional view of the plate 104 of the sound wave beam forming member 14 taken along the second direction Y.

Referring to FIG. 10, at least some of the grooves formed in the plate 104 of the acoustic beam forming member 14 according to the present embodiment have an inclined base surface. The acoustic beam forming member 13 according to the embodiment of FIG. 9 Is different.

In the cross-sectional view of the plate 104 cut in the second direction (Y), the first groove is the 1-1 groove 211, the 1-2 groove 212, the 1-3 groove 213, the first It may include -4 grooves 214 and 1-5 grooves 215. The positional relationship between the 1-1 groove 211 to the 1-5 groove 215 is as described above. That is, the 1-1 groove 211 is a first groove located approximately at the center, and the 1-2 groove 212 and the 1-4 groove 214 are the second groove 211 compared to the 1-1 groove 211. It is a first groove located on one side (Y1) in the direction, and the 1-3th groove 213 and the first-5 groove 215 are located on the other side (Y2) in the second direction compared to the first-first groove 211. It can be 1 groove.

In an exemplary embodiment in which the shape of the plate 104 is circular in plan, at least some of the base surfaces of the grooves located on the semicircular surface of the second direction (Y1) have an inclined surface, but the other side (Y2) in the second direction has a semicircular surface. The base surfaces of the located grooves may have a flat base surface that does not have a slope.

For example, the base surface of the 1-2 groove 212 and the 1-4 groove 214 has a base surface inclined upward toward one side Y1 in the second direction, but the 1-3 groove 213 and The base surface of the 1-5th groove 215 may have a base surface parallel to a plane to which the first direction X and the second direction Y belong. The base surface of the 1-1st groove 211 located in the center of the plane may also have a base surface that is inclined upward toward one side Y1 in the second direction. In another embodiment, the base surface of the first-first groove 211 may not have an inclination.

For another example, although not indicated by reference numerals, the base surfaces of the 2-2 grooves and the 2-4 grooves have a base surface inclined upward toward one side (Y1) in the second direction, but the 2-3 groove and the second -5 The base surface of the groove may not have a slope.

The sound wave forming member 14 according to the present exemplary embodiment may refract sound waves incident and traveling in the third direction Z so as to be inclined toward one side Y1 in the second direction with respect to a plane normal. In this case, the base surface of the grooves located on one side in the second direction (Y1) is configured to be inclined upward toward one side in the second direction (Y1), so that a high gain can be achieved in converting the surface wave traveling along the surface of the plate 104 into a radiation wave. I can.

In some embodiments, the angle of inclination of the inclined base surface of the grooves may be partially different. For example, the inclination angle of the base surface of the deep groove may be greater than the inclination angle of the base surface of the small depth groove. In this specification, the inclination angle of the inclined surface refers to an angle formed by the inclined surface with respect to a plane to which the first direction (X) and the second direction (Y) belong.

That is, the first inclination angle θ ₁ of the base surface of the first groove including the 1-2 groove 212 and the 1-4 groove 214 is the second inclination angle θ of the base surface of the second groove 220 _It can be greater than ₂ ). In addition, the third inclination angle θ ₃ of the base surface of the third groove 230 having a depth smaller than the first groove and having a greater depth than the second groove 220 is smaller than the first inclination angle θ ₁ and the second inclination angle It can be greater than (θ ₂ ).

As described above, a surface wave or a subsurface wave traveling along the surface of the plate 104 may be converted to a radiation wave due to a surface admittance determined by the depth of the groove while traveling radially from the center of the plate 104. In this case, the conversion efficiency can be increased by using the angle of the base surface of the groove in the intended area.

On the other hand, the cross-sectional view of the plate 104 cut along the first direction X is not shown, but the depth of the grooves 210 and 220 along the first direction X is the same as described above. Therefore, redundant descriptions are omitted.

Hereinafter, a sound wave control system using the aforementioned sound wave beam forming members will be described.

11 and 12 are schematic diagrams illustrating a sound wave control system 1 according to an embodiment of the present invention, and FIG. 11 is a schematic diagram illustrating a case where the sound wave beam forming members 11 are not overlapped, and FIG. 12 is a sound wave It is a schematic diagram showing the case where the beam forming member 11 is superimposed.

11 and 12, the sound wave control system 1 according to the present embodiment may include a sound wave source 20 and a sound wave beam forming member 11 disposed on the sound wave source 20. In an exemplary embodiment, the sound wave beam forming member 11 may be configured to move along the second direction Y on the sound wave source 20.

Here, the sound wave beam forming member 11 may have one surface in which a groove is formed and the other flat surface, and the sound wave beam forming member 11 may be disposed such that the other flat surface faces the sound wave source 20.

When the sound wave beam forming member 11 is not disposed as shown in FIG. 11, sound waves generated from the sound wave source 20 may be approximately evenly spread toward the front. On the other hand, as shown in FIG. 12, when the sound wave beam forming member 11 moves in one side of the third direction (Z) of the sound wave source 20 and is disposed, the sound wave is inclined toward one side (Y1) in the second direction to form a sound wave beam. have. Accordingly, the magnitude of the sound wave toward the other direction, for example, the other side Y2 in the second direction and the third direction Z may be significantly reduced.

In the present embodiment, the case of using the sound wave beam forming member according to the embodiment of FIG. 1 as the sound wave beam forming member 11 is illustrated, but the present invention is not limited thereto.

13 to 15 are schematic diagrams showing a sound wave control system 2 according to another embodiment of the present invention, FIG. 13 is a schematic diagram showing a case where the sound wave beam forming members are not overlapped, and FIG. 14 is a second sound wave beam It is a schematic diagram showing a case where the forming members 11' are superimposed, and FIG. 15 is a schematic diagram showing a case where the first sound wave beam forming members 11 are superposed.

13 to 15, the sound wave control system 2 according to the present embodiment includes a sound wave source 20 and a plurality of sound wave beam forming members 11 and 11 ′, and a first sound wave beam forming member 11 ) And the second sound wave beam forming member 11 ′ may be configured to move along the second direction Y on the sound wave source 20. Here, in the first sound wave beam forming member 11 and the second sound wave beam forming member 11 ′, each of the sound waves traveling in the third direction Z reaches one side in the second direction (Y1) and the other side in the second direction (Y2). It may be in a state of admittance patterned so as to be refracted with an inclination toward.

When the sound wave beam forming members are not overlapped as shown in FIG. 13, sound waves generated from the sound wave source 20 may be approximately evenly spread toward the front.

On the other hand, as shown in FIG. 14, when the second sound wave beam forming member 11 ′ is disposed to overlap the sound wave source 20 in the third direction (Z), the sound wave is inclined toward the other side (Y2) in the second direction to form a sound wave beam. can do.

In addition, as shown in FIG. 15, when the first sound wave beam forming member 11 is disposed to overlap the sound wave source 20 in the third direction (Z), the sound wave is inclined to one side (Y1) in the second direction to form a sound wave beam. I can.

That is, the sound wave control system 2 according to the present embodiment includes a plurality of sound wave beam forming members configured to form sound wave beams in different directions, so that the traveling direction of the sound wave can be freely changed. In particular, since the sound wave control system 2 can be miniaturized, various applications can be expected.

In the present embodiment, a case in which the sound wave beam forming member according to the exemplary embodiment of FIG. 1 is used as the sound wave beam forming members 11 and 11 ′ is exemplified, but the present invention is not limited thereto.

16 and 17 are schematic diagrams showing a sound wave control system 3 according to another embodiment of the present invention, and FIG. 16 is a schematic diagram showing a case where the sound wave beam forming member 11 is superimposed on a sound wave source, 17 is a schematic diagram showing a state in which the sound wave beam forming member 11 is rotated.

16 and 17, the sound wave control system 3 according to the present embodiment may be configured such that the sound wave beam forming member 11 is rotatable on the sound wave source 20. In some embodiments, the sound wave beam forming member 11 may be configured to be movable along the second direction Y as well as rotation.

As shown in FIG. 16, when the sound wave beam forming member 11 is overlapped on the sound wave source 20, the sound wave generated from the sound wave source 20 may be inclined toward one side Y1 in the second direction to form a sound wave beam.

On the other hand, as shown in FIG. 17, when the sound wave beam forming member 11 rotates within the plane to which the first direction (not shown) and the second direction (Y) belong, the sound wave generated from the sound wave source 20 is the other side in the second direction ( It can be tilted to Y2) to form a sound wave beam.

That is, since the sound wave control system 3 according to the present embodiment includes only one sound wave beam forming member 11 and can freely change the traveling direction of the sound wave, the sound wave control system 3 can be further downsized.

18 is a schematic diagram showing a sound wave control system 4 according to another embodiment of the present invention, and is a schematic diagram showing a state in which the sound wave beam forming member 11 is disposed on a sound wave source but is tilted.

Referring to FIG. 18, the sound wave control system 4 according to the present embodiment includes a sound wave source 20 and a sound wave beam forming member 11, and the sound wave beam forming member 11 is at an angle on the sound wave source 20. It may be configured to be adjustable or tiltable. That is, the degree of inclination of the sound wave may vary according to the angle formed by the normal line on the sound wave source 20 and the top surface (pattern surface) of the sound wave beam forming member 11.

In some embodiments, the sound wave control system 4 may be configured such that the sound wave beam forming member 11 is not only controlled to be tilted, but also rotates or linearly moves, as in this embodiment.

In the present embodiment, the case of using the sound wave beam forming member according to the embodiment of FIG. 1 as the sound wave beam forming member 11 is illustrated, but the present invention is not limited thereto.

Hereinafter, the present invention will be described in more detail with reference to experimental examples.

[Example 1]

A sound wave beam forming member having regular grooves was manufactured using a 3D printer. The sound wave beam forming member was manufactured in the form of a disk having a diameter of 100 mm.

The groove was formed in a circular shape with a diameter of about 1.42 mm. And a plurality of circular grooves were hexagonally arranged. In the hexagonal arrangement, the arrangement pitch between adjacent grooves was 2 mm.

The depth of the groove was designed through the following process. That is, for a sound wave having a frequency of 30 kHz (wavelength: about 11.43 mm), the wave number according to the depth of the groove was calculated, and the admittance change at this time was estimated by a 5th-order polynomial regression method to derive Equation 1 below.

[Equation 1]

And the following Equation 2 was derived to design an admittance pattern that is refracted in a direction inclined in the direction of 30 degrees with respect to the normal.

[Equation 2]

In Equations 1 and 2, each constant and variable are as defined above.

In addition, by matching Equations 1 and 2, d values according to x and y were derived. Each of x and y was a value according to a Cartesian coordinate system with the center of the disk as an origin. The depth of the groove was determined according to the derived d, and it was configured to have the depth determined at the corresponding coordinates.

Then, the surface admittance value represented by Equation 3 was calculated and imaged and shown in FIG. 19. In FIG. 19, the admittance of the red area was about 1.8 and the admittance of the purple area was about 0.2. In Equation 3 below, Y ₀ is the admittance of air.

[Equation 3]

[Example 2]

A disk-shaped acoustic beam forming member was manufactured in the same manner as in Example 1, except that the admittance pattern refracted in the direction inclined in the direction of 45 degrees to the normal was designed and the depth of the groove was adjusted.

That is, the depth of the groove was adjusted by applying Equation 2 differently from Example 1 as follows and matching Equations 1 and 2 to derive d values according to x and y.

[Equation 2]

In addition, the surface admittance value was calculated according to Equation 3 described above, and the image was imaged and shown in FIG. 20.

[Example 3]

A disk-shaped acoustic beam forming member was manufactured in the same manner as in Example 1, except that an admittance pattern that was refracted in a direction inclined in a direction inclined to a normal line was designed and the depth of the groove was adjusted.

That is, the depth of the groove was adjusted by applying Equation 2 differently from Example 1 as follows and matching Equations 1 and 2 to derive d values according to x and y.

[Equation 2]

Then, the surface admittance value was calculated according to Equation 3 described above, and the image was imaged and shown in FIG. 21.

[Experimental Example]

A 300mm×300mm×300mm type of enclosed space was constructed. In addition, a speaker was attached as a sound wave source in the center of one wall, and a previously manufactured sound wave forming member was placed in front of the speaker. The coordinates of the speaker's space were defined as (0,150). And the sound pressure level (SPL) at each coordinate position from spatial coordinates (0,0) to (300,300) was measured using a microphone. The measurement of the sound pressure level was performed in units of 1 mm for each of the x coordinate and y coordinate. Based on the measured results, a planar sound pressure distribution in a 300mm×300mm space was simulated, and the results are shown in FIGS. 22 to 24. 22 to 24 are results of simulations of sound pressure levels in the sound wave control systems according to Examples 1, 2, and 3, respectively.

First, referring to FIG. 22, it can be seen that the sound pressure is concentrated in a direction inclined by about 30 degrees with respect to the normal based on the position (0,150) of the speaker and the sound wave forming member. In addition, it can be seen that sound pressure can be transmitted to a long distance without loss of sound waves as it exhibits a uniform sound pressure even over a relatively long distance.

In the upper view of FIG. 22, the vertical axis means x coordinate and the horizontal axis means y coordinate. In addition, the closer to red, the higher the sound pressure, that is, indicating that a sound wave beam is formed. In the lower view of FIG. 22, the closer to light green, the higher the sound pressure.

Next, referring to FIG. 23, it can be seen that the sound pressure is concentrated in a direction inclined by about 45 degrees with respect to the normal. In addition, it can be seen that sound waves can be transmitted to a long distance without loss of sound waves.

In the upper drawing of FIG. 23, the vertical axis means the x coordinate, and the horizontal axis means the y coordinate. Also, the closer to red, the higher the sound pressure. In the lower drawing of FIG. 23, the closer to light green, the higher the sound pressure.

Next, referring to FIG. 24, it can be seen that the sound pressure is concentrated in a direction inclined by about 60 degrees with respect to the normal. In addition, it can be seen that sound waves can be transmitted to a long distance without loss of sound waves.

In the upper drawing of FIG. 24, the vertical axis indicates the x coordinate and the horizontal axis indicates the y coordinate. Also, the closer to red, the higher the sound pressure. In the lower drawing of FIG. 24, the closer to light green, the higher the sound pressure.

The embodiments of the present invention have been described above, but these are only examples and do not limit the present invention, and those of ordinary skill in the field to which the present invention pertains should not depart from the essential characteristics of the embodiments of the present invention. It will be appreciated that various modifications and applications not illustrated above are possible.

Therefore, the scope of the present invention should be understood to include modifications, equivalents, or substitutes of the technical idea exemplified above. For example, each component specifically shown in the embodiment of the present invention can be modified and implemented. And differences related to these modifications and applications should be construed as being included in the scope of the present invention defined in the appended claims.

1: sound wave control system
11: sound wave beam forming member
101: plate
200: home
210: first groove
220: second groove

Claims (18)

A sound wave beam forming member including a plate in which a plurality of grooves are regularly arranged, at least some of the plurality of grooves have different depths, the frequency of the sound wave to be controlled is 1 kHz to 30 kHz, and the maximum depth of the plurality of grooves Is in the range of 1.5 to 1.7 times the maximum width of the groove, and the minimum depth of the plurality of grooves is in the range of 0.5 to 0.6 times the maximum width of the groove. The method of claim 1,
In a plan view, the repeating units of the plurality of grooves are hexagonally arranged,
An arrangement pitch between adjacent grooves is 1.4 times or more and less than 2 times the maximum width of the grooves. The method of claim 1,
The maximum width of the groove is a sound wave forming member smaller than the wavelength of the sound wave to be controlled. The method of claim 1,
In the plane view,
A sound wave beam forming member configured such that the depths of the plurality of grooves are symmetrical in a first direction with respect to a center, and the depths of the plurality of grooves are asymmetrical in a second direction perpendicular to the first direction. The method of claim 1,
The maximum thickness of the plate is a sound wave beam forming member in the range of 2 to 3.5 times the maximum width of the groove. A sound wave beam forming member including a plate in which a plurality of grooves are arranged, the depth of the plurality of grooves is symmetrical in a first direction based on a certain center, but is asymmetric in a second direction crossing the first direction,
In the cross section of the plate cut in the second direction, grooves having a maximum depth are defined as first grooves, grooves having a minimum depth are defined as second grooves, and the first groove and the second groove are the Arranged spaced apart along the second direction,
At least one second groove is located between the two first grooves spaced apart in the second direction and adjacent to each other,
A sound wave beam forming member in which at least one first groove is positioned between the two second grooves spaced apart in the second direction and adjacent to each other. delete The method of claim 6,
The first grooves,
A 1-1 groove, a 1-2 groove located on one side of the first-first groove in the second direction, and a 1-3 groove located on the other side of the first-first groove in the second direction,
A minimum separation distance between the 1-1 groove and the 1-2 groove is greater than the minimum separation distance between the 1-1 groove and the 1-3 groove. The method of claim 8,
The first grooves further include a 1-4 groove located on one side of the 1-2 groove in the second direction, and a 1-5 groove located on the other side of the 1-3 groove in the second direction, ,
The minimum separation distance between the 1-2 groove and the 1-4 groove is greater than the minimum separation distance between the 1-1 groove and the 1-2 groove,
A minimum separation distance between the 1-3 grooves and the 1-5 grooves is greater than the minimum separation distance between the 1-1 grooves and the 1-3 grooves. The method of claim 9,
The second grooves,
2-1 groove,
A 2-2 groove located on one side of the 2-1 groove in the second direction,
A 2-3rd groove located on the other side in the second direction of the 2-1 groove,
A 2-4 groove located on one side of the 2-2 groove in the second direction, and
It includes a 2-5 groove located on the other side of the second direction of the 2-3 groove,
The minimum separation distance between the 2-1 groove and the 2-2 groove is greater than the minimum separation distance between the 2-1 groove and the 2-3 groove,
The minimum separation distance between the 2-2 groove and the 2-4 groove is greater than the minimum separation distance between the 2-1 groove and the 2-2 groove,
A minimum separation distance between the 2-3rd groove and the 2-5th groove is greater than a minimum separation distance between the 2-1 groove and the 2-3rd groove. The method of claim 8,
The base surface of the 1-2 groove forms an inclined surface inclined upward toward one side in the second direction,
A sound wave beam forming member that does not form an inclined base surface of the first-3 groove. The method of claim 11,
At least a portion of the base surface of the second groove forms an inclined surface,
An inclination angle of the base surface of the 1-2 groove is larger than the inclination angle of the base surface of the second groove. The method of claim 6,
Among the first grooves defined above, a separation distance between the two first grooves closest to each other is defined as a first separation distance,
Among the defined second grooves, a separation distance between the two second grooves closest to each other is defined as a second separation distance,
The first separation distance and the second separation distance are each of the sound wave forming member gradually increasing from the center portion to the edge portion of the sound wave forming member. The method of claim 6,
The sound wave beam forming member,
A sound wave forming member for imparting directivity so that the sound waves incident in the thickness direction of the plate are inclined toward the second direction. A sound wave beam forming member comprising a plate in which a plurality of grooves are regularly arranged, wherein at least some of the plurality of grooves have different depths, and at least some have the same depth,
The relationship between the depth (d) of the groove and the position (x, y) on the plane is a sound wave beam forming member configured to satisfy the following equation.
[Equation]

(Where A ₁ , A ₂ , A ₃ , A ₄ , A ₅ and A ₆ are each positive number having a predetermined value, B is a positive number between 0.8 and 1.5, M is a positive number between 0.5 and 0.7, λ is the wavelength of the sound wave to be modulated, n is a positive number between 1.3 and 1.5, θ is the angle to be refracted, d is the depth of the groove, and x and y are the first values based on an arbitrary center, respectively. 1 direction and the coordinate value in the second direction perpendicular to the first direction) delete Sound wave source; And
A sound wave control system comprising a sound wave beam forming member according to any one of claims 1 to 6 and 8 to 15 disposed adjacent to the sound wave source. delete

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