Vibrator, acoustic system, acoustic system control method, and acoustic system manufacturing method

Abstract

To generate a moment in a vibrating member.SOLUTION: A vibrator 120 includes a first vibration unit 101 that generates a vibration force to be applied to an attached vibration member 220, a second vibration unit 102 that is attached to the vibration member 220 and generates a vibration force to be applied to the vibration member 220, and a regulating member 109 to which the first vibration unit 101 and the second vibration unit 102 are fixed and which regulates the relative movement between the first vibration unit 101 and the second vibration unit 102.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a vibrator including a plurality of vibration units, an acoustic system, an acoustic system control method, and an acoustic system manufacturing method.

Background Art

[0002] Patent Document 1 describes a technique for effectively suppressing noise caused by a predetermined frequency by vibrating a vibrator attached to a predetermined portion of a vibration member.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in a conventional vibrator, a vibration mode in which the attachment position becomes a node of the vibration of the vibration member cannot be excited.

[0005] The present disclosure has been made in view of the above problems, and provides a vibrator capable of applying a rotational moment to a vibration member, an acoustic system including the vibrator, exciting a plurality of vibration mode vibration members including a case where the attachment position is a node, and suppressing the sound wave transmission amount, an acoustic system control method, and an acoustic system manufacturing method.

Means for Solving the Problems

[0006] A vibrator according to one aspect of the present disclosure includes a first vibration unit that generates a vibration force applied to an attached vibration member, a second vibration unit that is attached to the vibration member and generates a vibration force applied to the vibration member, and a regulation member to which the first vibration unit and the second vibration unit are fixed and that regulates a relative movement between the first vibration unit and the second vibration unit.

[0007] One of the acoustic systems according to the present disclosure includes a first vibration unit that generates a vibration force applied to an attached vibration member, a second vibration unit that is attached to the vibration member and generates a vibration force applied to the vibration member, a regulating member to which the first vibration unit and the second vibration unit are fixed and that regulates relative movement between the first vibration unit and the second vibration unit, a first correction filter that corrects an acoustic signal and outputs the corrected signal to the first vibration unit, and a second correction filter that corrects the acoustic signal and outputs the corrected signal to the second vibration unit. The acoustic system further includes a vibrator including the first correction filter and the second correction filter, and an acoustic generator that generates sound waves based on the acoustic signal. The first correction filter and the second correction filter correct the acoustic signal so as to reduce transmitted sound through which the sound waves pass through the vibration member, and output the corrected signal to the first vibration unit and the second vibration unit, respectively.

[0008] One of the acoustic system control methods of the present disclosure includes a first vibration unit that generates a vibration force applied to an attached vibration member, a second vibration unit that is attached to the vibration member and generates a vibration force applied to the vibration member, a regulating member to which the first vibration unit and the second vibration unit are fixed and that regulates the relative movement between the first vibration unit and the second vibration unit, a first correction filter that corrects an acoustic signal and outputs it to the first vibration unit, and a second correction filter that corrects the acoustic signal and outputs it to the second vibration unit. The acoustic system control method further includes a vibrator comprising these components, and an acoustic generating device that generates sound waves based on the acoustic signal. The first correction filter and the second correction filter are configured to set the filter characteristics of the correction filters included in the acoustic system that corrects the acoustic signal and outputs it to the first vibration unit and the second vibration unit respectively so as to reduce the transmitted sound of the sound waves passing through the vibration member. The method comprises arranging the acoustic generating device on one side of the vibration member to which the vibrator is attached, arranging a measuring device on the other side of the vibration member, causing the measuring device to measure at least one of the sound waves generated by the acoustic generating device based on the acoustic signal and the vibration of the vibration member caused by the sound waves generated by the acoustic generating device to obtain a target measurement signal, and setting the filter characteristics of the correction filter based on the target sound pressure transfer function between the acoustic signal and the target measurement signal.

[0009] One of the manufacturing methods of the acoustic system according to the present disclosure includes a first vibration unit that generates a vibration force applied to an attached vibration member, a second vibration unit that is attached to the vibration member and generates a vibration force applied to the vibration member, a regulating member to which the first vibration unit and the second vibration unit are fixed and that regulates the relative movement between the first vibration unit and the second vibration unit, a first correction filter that corrects an acoustic signal and outputs it to the first vibration unit, and a second correction filter that corrects the acoustic signal and outputs it to the second vibration unit. The method further includes a vibrator including these components, and an acoustic generating device that generates sound waves based on the acoustic signal. The first correction filter and the second correction filter correct the acoustic signal so as to reduce the transmitted sound through which the sound waves pass through the vibration member, and output the corrected signal to the first vibration unit and the second vibration unit respectively. The method for manufacturing an acoustic system is as follows: An acoustic generating device is arranged on one side of a vibration member to which the vibrator is attached, a measuring device is arranged on the other side of the vibration member, at least one of the sound waves generated by the acoustic generating device based on the acoustic signal and the vibration of the vibration member caused by the sound waves generated by the acoustic generating device is measured by the measuring device to obtain a target measurement signal, and filter characteristics of the correction filter are set based on a target sound pressure transfer function between the acoustic signal and the target measurement signal.

Effect of the Invention

[0010] According to the present disclosure, it is possible to provide a vibrator that can apply a rotational moment to a vibration member, and a system that effectively suppresses vibration caused by sound waves generated by the vibrator.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

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Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0012] Hereinafter, embodiments of a vibration generator, an acoustic system, an acoustic system control method, and an acoustic system manufacturing method according to the present disclosure will be described with reference to the drawings. Note that the following embodiments are examples for explaining the present disclosure and are not intended to limit the present disclosure. For example, the shapes, structures, materials, components, relative positional relationships, connection states, numerical values, mathematical formulas, the content of each step in the method, the order of each step, etc. shown in the following embodiments are examples, and may include content not described below. In addition, geometric expressions such as parallel and orthogonal may be used, but these expressions do not indicate mathematical precision and include substantially allowable errors, deviations, etc. Also, expressions such as simultaneous and identical also include a substantially allowable range.

[0013] Further, the drawings are schematic diagrams that have been appropriately emphasized, omitted, or adjusted in ratio for explaining the present disclosure, and are different from the actual shapes, positional relationships, and ratios. Also, the X-axis, Y-axis, and Z-axis that may be shown in the drawings represent orthogonal coordinates arbitrarily set for the explanation of the drawings. That is, the Z-axis does not necessarily follow the vertical direction, and the X-axis and Y-axis do not necessarily exist in the horizontal plane.

[0014] In addition, in the following, there may be cases where a plurality of inventions are comprehensively described as one embodiment. Also, a part of the content described below is explained as an arbitrary component related to the present disclosure.

[0015] FIG. 1 is a perspective view showing the appearance of the vibrator 120 with a part of the suspension 127 cut away. FIG. 2 is a cross-sectional view showing the internal structure of the vibrator 120. The vibrator 120 is a so-called actuator (exciter) that is attached to the vibrating member 220 and vibrates the vibrating member 220 based on the input acoustic signal, and is composed of a vibration unit that generates a vibration force and a reaction force generation mechanism that generates a reaction force opposing the vibration force. The vibrator 120 includes a first vibration unit 101, a second vibration unit 102, and a regulating member 109.

[0016] The first vibration unit 101 is a device that generates a vibration force to be applied to the attached vibrating member 220 (described later). The type of the vibration unit of the vibrator 120 is not limited, and examples include those using a piezoelectric element and those using a magnetostrictive element. Also, as the reaction force generation mechanism, examples include those using an inertial force generated by the mass effect of a movable part including a magnet and a regulating member, and those using a structural reaction force generated by connecting one end of the movable part to another structural member. In the case of the present embodiment, the first vibration unit 101 is a magnet type voice coil motor including a magnet 121, a top plate 122, a bottom plate 123, a voice coil 124, a suspension 127, and an attachment member 126.

[0017] The magnet 121 is a magnetized cylindrical permanent magnet.

[0018] The top plate 122 is attached to one end surface of the magnet 121. In the case of the present embodiment, the top plate 122 is circular plate-shaped, larger than the diameter of the cylindrical magnet 121, and the central axis of the magnet 121 and the central axis of the top plate coincide.

[0019] The bottom plate 123 is attached to the other end face of the magnet 121 and is a yoke that guides the magnetic flux emerging from the other end face of the magnet 121 to the vicinity of the circumferential surface of the top plate 122. In the case of the present embodiment, the bottom plate 123 has a bottomed cylindrical shape, and an annular flange portion 128 extends outward. The bottom plate 123 coaxially houses the magnet 121 and the top plate 122, and an annular magnetic gap 129 is formed between the top plate 122 and the bottom plate 123.

[0020] The voice coil 124 is a coil disposed in the magnetic gap 129 to which an acoustic signal 201 is input. Due to the interaction between the fluctuating magnetic force generated in the voice coil 124 and the stationary magnetic force existing in the magnetic gap 129, a vibration force corresponding to the acoustic signal 201 is generated in the winding axis direction of the voice coil 124 (the Z-axis direction in the figure). In the case of the present embodiment, the voice coil 124 is wound around the outer circumference of a cylindrical bobbin 125.

[0021] The suspension 127 is a member that elastically connects between the bobbin 125 and the flange portion 128. The suspension 127 supports the voice coil 124 and the bobbin 125 to vibrate linearly in the winding axis direction of the voice coil 124 (the Z-axis direction in the figure).

[0022] The attachment member 126 is an annular member attached to the vibration member 220. The attachment member 126 is attached to the voice coil 124 via the bobbin 125 and transmits the vibration of the voice coil 124 to the vibration member 220.

[0023] With the above configuration, the vibrator 120 reciprocates the magnetic circuit having the magnet 121, the top plate 122, and the bottom plate 123 and the voice coil body having the voice coil 124, the bobbin 125, and the mounting member 126 relative to each other in the winding axis direction of the voice coil 124 to generate vibration. The vibrator 120 can apply vibration corresponding to the acoustic signal 201 to the vibration member 220 joined to the mounting member 126 by adhesion. As a result, sound waves corresponding to the acoustic signal 201 are generated from the vibration member 220. In the above, the first vibration unit 101 includes an internal magnetic type magnetic circuit, but the first vibration unit 101 may include an external magnetic type magnetic circuit.

[0024] The second vibration unit 102 is attached to the vibration member 220 to which the first vibration unit 101 is attached and generates a vibration force applied to the vibration member 220. In the case of this embodiment, since the second vibration unit 102 is of the same type as the first vibration unit 101, the description thereof is omitted. Note that the second vibration unit 102 does not have to be of the same type as the first vibration unit 101.

[0025] The regulating member 109 is a structural member to which the first vibration unit 101 and the second vibration unit 102 are fixed and that regulates the relative movement between the first vibration unit 101 and the second vibration unit 102. Even when different acoustic signals 201 are input to each of the first vibration unit 101 and the second vibration unit 102 attached to the vibration member 220, the regulating member 109 maintains the parallelism of the winding axes of the respective voice coils 124 and has rigidity capable of regulating relative movements such that the two winding axes are in a twisted arrangement or the distance between the two winding axes changes. Further, the regulating member 109 has a predetermined mass and generates an inertial force that becomes a driving force reaction due to the mass effect together with the magnets 121, yokes 123, etc. of the first vibration unit 101 and the second vibration unit 102 connected to the regulating member 109. The shape of the regulating member 109 is not limited. As the shape of the regulating member 109, not only a disc shape as shown in FIG. 1 but also any shape such as a rectangle or a triangle can be adopted.

[0026] FIG. 3 is a diagram showing an acoustic system 100. The acoustic system 100 generates sound waves in a predetermined first space 211, and in a second space 212 separated from the first space 211 by a vibrating member 220, there is a system for reducing the volume of the transmitted sound that has passed through the vibrating member 220, that is, a system for reducing the vibration of the vibrating member 220 caused by the sound waves generated in the first space 211, and includes an acoustic generating device 110, a vibrator 120, a first correction filter 131, and a second correction filter 132. In the case of this embodiment, the acoustic system 100 includes a delay filter 140, a common filter 150, a first drive amplifier 161, a second drive amplifier 162, and a third drive amplifier 163.

[0027] The first space 211 is a space in which sound waves are emitted by the acoustic generating device 110. The first space 211 is not limited. For example, as shown in FIG. 4, the first space 211 may be the internal space of a moving body such as a vehicle, a ship, or an aircraft, and when the acoustic generating device 110 emits sound waves into the passenger compartment space 213 of the moving body, it may function as a space that blocks the intrusion of the rear sound of the speaker unit of the acoustic generating device 110. Furthermore, it may be the internal space of a general speaker system enclosure.

[0028] The second space 212 is a space separated from the first space 211 by the vibration member 220. The second space 212 is a space in which it is desired to minimize as much as possible the transmission of sound waves emitted into the first space 211 by the acoustic generator 110 through the vibration member. Note that the first space 211 and the second space 212 may be separated by the vibration member 220, or may be separated by the vibration member 220 but may be spatially connected. Also, in the case where the first space 211 is the internal space of the cabinet (enclosure) of the speaker system, etc., the second space 212 may be spatially connected to or an equivalent space to the interior space 213 of the vehicle cabin where the acoustic generator 110 emits sound waves. Note that the interior space 213 of the vehicle cabin is not limited. For example, when the first space 211 is the internal space of the cabinet (enclosure) of a general speaker system, it may be an indoor or outdoor non-mobile space where sound waves are emitted from the acoustic generator 110.

[0029] The vibration member 220 is a member to which vibration is applied by the vibrator 120. The vibration member 220 is not limited. For example, as shown in FIG. 4, the vibration member 220 may be part or all of the door of a moving body such as a vehicle, ship, or aircraft, or part or all of the body. Also, the vibration member 220 may be a wall, fence, etc. provided to separate the first space 211 and the second space 212. Also, in the case where the first space 211 is the internal space of the cabinet (enclosure) of the speaker system, etc., the vibration member 220 may be a structural member of the cabinet (enclosure).

[0030] The sound generating device 110 is a device that generates sound waves in the first space 211 based on the acoustic signal 201 output from the signal source 200. The type of the sound generating device 110 is not limited. For example, the sound generating device 110 can be exemplified by a speaker unit, an acoustic vibration generator that vibrates an object to emit sound, and the like. Further, the sound generating device 110 may include a cabinet (enclosure) that houses the speaker unit, a vibration member 220 to which the acoustic vibration generator is attached, and the like. Further, the sound generating device 110 may include a plurality of speaker units, a plurality of acoustic vibration generators, or may be a multi-way speaker including a plurality of types of speaker units.

[0031] In the acoustic system 100, the vibration generator 120 is the vibration generator 120 described above, and includes a first vibration unit 101, a second vibration unit 102, and a regulating member 109. The acoustic signal 201 output to the vibration generator 120 and the acoustic signal 201 output to the sound generating device 110 are acoustic signals 201 output from the same source, and the acoustic signal 201 output from the same signal source 200 is branched into three and output to the sound generating device 110, the first vibration unit 101 of the vibration generator 120, and the second vibration unit 102, respectively. Note that the type of the vibration unit is not limited, and it may be one using a piezoelectric element, one using a magnetostrictive element, or the like. Further, as the reaction force generating mechanism, one using the inertial force generated by the mass effect of the movable part including a magnet and a regulating member or the like, or one using the structural reaction force generated by connecting one end of the movable part to another structural member may be used.

[0032] The first correction filter 131 corrects one of the branched acoustic signals 201 and outputs it to the first vibration unit 101 of the vibration generator 120. In the case of the present embodiment, the first correction filter 131 has filter characteristics unique to the acoustic system 100. The filter characteristics of the first correction filter 131 are characteristics determined by at least the sound generating device 110, the vibration generator 120, and the vibration member 220 to which the vibration generator 120 is attached. Note that a method for setting the filter characteristics of the specific first correction filter 131 will be described later.

[0033] The second correction filter 132 corrects one of the branched acoustic signals 201 and outputs it to the second vibration unit 102 of the vibrator 120. In the case of the present embodiment, the second correction filter 132 has filter characteristics specific to the acoustic system 100. The filter characteristics of the second correction filter 132 are characteristics determined by at least the acoustic generator 110, the vibrator 120, and the vibration member 220 to which the vibrator 120 is attached. Note that a method for setting the specific filter characteristics of the second correction filter 132 will be described later.

[0034] The first correction filter 131 and the second correction filter 132 correct the two branched acoustic signals 201 output to the vibrator 120 so as to reduce the transmitted sound of the sound wave generated in the first space 211 by the acoustic generator 110 and transmitted through the vibration member 220 to reach the second space 212.

[0035] The delay filter 140 is a filter that delays the acoustic signal 201 output to the acoustic generator 110 by Δt (a fixed value) compared to the acoustic signal 201 output to the vibrator 120. Note that "t" represents time.

[0036] The common filter 150 is a filter that corrects the acoustic signals 201 output to the vibrator 120 and the acoustic generator 110, respectively. The common filter 150 cuts signal components that cannot completely suppress the amount of sound waves generated by the acoustic generator 110 and transmitted through the vibration member 220 only by the first correction filter 131 and the second correction filter 132, or only by the first correction filter 131, the second correction filter 132, and the delay filter 140. In the case of the present embodiment, the common filter 150 corrects the acoustic signal 201 output from the signal source 200 and before being branched. Note that the common filter 150 may correct each of the branched acoustic signals 201.

[0037] The first drive amplifier 161 amplifies the acoustic signal 201 output from the signal source 200 until the acoustic generating device 110 can be driven to emit sound into the first space 211. In the case of this embodiment, the first drive amplifier 161 amplifies the acoustic signal 201 corrected by the common filter 150 and corrected by the delay filter 140.

[0038] The second drive amplifier 162 amplifies the acoustic signal 201 output from the signal source 200 so as to drive the first vibration unit 101 to vibrate the vibration member 220. In the case of this embodiment, the second drive amplifier 162 amplifies the acoustic signal 201 corrected by the common filter 150 and corrected by the first correction filter 131.

[0039] The third drive amplifier 163 amplifies the acoustic signal 201 output from the signal source 200 so as to drive the second vibration unit 102 to vibrate the vibration member 220. In the case of this embodiment, the third drive amplifier 163 amplifies the acoustic signal 201 corrected by the common filter 150 and corrected by the second correction filter 132.

[0040] The second drive amplifier 162 and the third drive amplifier 163 amplify the acoustic signal 201 to such an extent that the amount of sound waves emitted into the first space 211 by the acoustic generating device 110 transmitted into the second space 212 can be suppressed.

[0041] Next, a characteristic creation system 300 that can set the filter characteristics of the first correction filter 131 included in the acoustic system 100 will be described. FIG. 5 is a diagram showing the characteristic creation system 300. The characteristic creation system 300 is a system that creates the filter characteristics of the first correction filter 131 included in the acoustic system 100, and includes a measurement acoustic generating device 310, a measurement vibrator 320, a measurement vibration member 329, a measurement sound source 330, a characteristic creation unit 340, a measurement device 350, a first measurement amplifier 361, a second measurement amplifier 362, a third measurement amplifier 363, a first changeover switch 371, a second changeover switch 372, a third changeover switch 373, and a fourth changeover switch 374.

[0042] The acoustic generating device 310 for measurement is a device that generates sound waves in the first measurement space 311 based on the measurement acoustic signal S output from the measurement sound source 330. It is desirable that the acoustic generating device 310 for measurement is the same as or of the same type as the acoustic generating device 110. Also, it is desirable that the mode in which the acoustic generating device 310 for measurement is attached to a cabinet or the like is the same as or substantially the same as the mode in which the acoustic generating device 110 is attached. Further, it is desirable that the position, posture, etc. of the measurement vibration member 329 of the acoustic generating device 310 for measurement are the same as or substantially the same as the position, posture, etc. of the vibration member 220 of the acoustic generating device 110.

[0043] The vibration exciter 320 for measurement is a device that vibrates the measurement vibration member 329 based on the measurement acoustic signal S output from the measurement sound source 330. It is desirable that the vibration exciter 320 for measurement is the same as or of the same type as the vibration exciter 120. Also, it is desirable that the mode in which the vibration exciter 320 for measurement is attached to the measurement vibration member 329 is the same as or substantially the same as the mode in which the vibration exciter 120 is attached to the vibration member 220.

[0044] The measurement sound source 330 outputs a measurement acoustic signal S for measurement. The measurement acoustic signal S for measurement does not have to be the acoustic signal 201 output to the acoustic system 100. For example, as the measurement acoustic signal S for measurement, a predetermined acoustic signal 201, a sine curve signal, a sweep sine signal, an impulse signal, a random noise signal, a colored noise signal, an M-sequence signal, a TSP (time stretch pulse) signal, etc. can be exemplified.

[0045] The measuring device 350 is a device that measures sound waves generated in the second measurement space 312 by driving the measurement acoustic generator 310 or the measurement shaker 320, or vibrations generated in the measurement vibration member 329 by driving the measurement acoustic generator 310 or the measurement shaker 320. As the measuring device 350 for measuring sound waves, a microphone can be exemplified. As the measuring device 350 for measuring vibrations, a displacement sensor, a velocity sensor, and an acceleration sensor can be exemplified. Note that the characteristic creation system 300 may include a plurality of measuring devices 350.

[0046] The characteristic creation unit 340 derives the filter characteristics of the first correction filter 131 included in the acoustic system 100 based on the target sound pressure transfer function between the target measurement signal Ps obtained by measuring the sound waves generated by the measurement acoustic generator 310 based on the measurement acoustic signal S or the vibrations of the measurement vibration member 329 caused by the sound waves in the second measurement space 312, which is not the first measurement space 311 where the measurement acoustic generator 310 of the measurement vibration member 329 is placed, and the measurement acoustic signal S. Also, the characteristic creation unit 340 derives the filter characteristics of the first correction filter 131 included in the acoustic system 100 based on the target sound pressure transfer function between the target measurement signal Ps obtained by measuring the sound waves generated by the measurement acoustic generator 310 based on the measurement acoustic signal S or the vibrations of the measurement vibration member 329 caused by the sound waves in the second measurement space 312 and the measurement acoustic signal S.

[0047] In the case of this embodiment, the characteristic creation unit 340 adds the corresponding sound pressure transfer functions between the sound waves generated by vibrating the measurement vibration member 329 separately by the first vibration unit 101 and the second vibration unit 102 of the measurement vibrator 320, or the corresponding measurement signals Pv1 and Pv2 obtained by measuring the vibration of the measurement vibration member 329, and the measurement acoustic signal S, at the same position as the position where the target measurement signal Ps is measured, and also derives the filter characteristics of the first correction filter 131 and the filter characteristics of the second correction filter 132, respectively. The characteristic creation unit 340 derives the filter characteristics using Fourier transform. The specific derivation method will be described later. The characteristic creation unit 340 is a processing unit realized by causing a processor included in a dedicated or general-purpose computer to execute a characteristic creation program.

[0048] The first measurement amplifier 361 amplifies the measurement acoustic signal S output from the measurement sound source 330 until the measurement sound generating device 310 is driven to emit sound into the first measurement space 311. The first measurement amplifier 361 is preferably the same as or of the same type as the first drive amplifier 161.

[0049] The second measurement amplifier 362 amplifies the measurement acoustic signal S output from the measurement sound source 330 until the first vibration unit 101 of the measurement vibrator 320 is driven to vibrate the measurement vibration member 329. The second measurement amplifier 362 is preferably the same as or of the same type as the second drive amplifier 162.

[0050] The third measurement amplifier 363 amplifies the measurement acoustic signal S output from the measurement sound source 330 until the second vibration unit 102 of the measurement vibrator 320 is driven to vibrate the measurement vibration member 329. The third measurement amplifier 363 is preferably the same as or of the same type as the third drive amplifier 163.

[0051] Note that, as shown in FIG. 8, the characteristic creation system 300 may create filter characteristics using a part of the acoustic system 100 attached to the moving body 210 or the like.

[0052] Next, a method for manufacturing the acoustic system 100 using the characteristic creation system 300 will be described. As shown in FIG. 5, the acoustic generator 310 for measurement is arranged at a predetermined position in the first measurement space 311. The vibration exciter 320 for measurement is attached to a predetermined position of the vibration member 329 for measurement. The vibration member 329 for measurement is arranged in the first measurement space 311 on one side of the vibration member 329 for measurement to which the vibration exciter 320 for measurement is attached. The measuring device 350 is arranged at a predetermined position in the second measurement space 312 on the other side of the vibration member 329 for measurement. When measuring the sound wave in the second measurement space 312, the measuring device 350 is arranged at a position away from the vibration member 329 for measurement. When measuring the vibration of the vibration member 329 for measurement, the measuring device 350 is arranged so as to be in contact with the vibration member 329 for measurement. In this case, the measuring device 350 may be in the first measurement space 311.

[0053] The first switch 371 and the second switch 372 are switched so that the acoustic generator 310 for measurement generates a sound wave based on the acoustic signal S for measurement (see FIG. 5). At this time, at least one (both in this embodiment) of the third switch 373 and the fourth switch 374 is switched so that the vibration exciter 320 for measurement is short-circuited.

[0054] The measuring device 350 measures the sound wave generated by the acoustic generator 310 for measurement or the vibration of the vibration member 329 for measurement caused by the sound wave to obtain the target measurement signal Ps. At this stage, based on the target sound pressure transfer function Hs between the acoustic signal S for measurement and the target measurement signal Ps, the characteristic creation unit 340 may derive the filter characteristic G of the first correction filter 131.

[0055] In this embodiment, next, the first switch 371 and the third switch 373 are switched so that the vibration member 329 for measurement vibrates the first vibration unit 101 of the vibration exciter 320 for measurement based on the acoustic signal S for measurement (see FIG. 6). At this time, the fourth switch 374 is switched so that the second vibration unit 102 is short-circuited. Note that the second switch 372 may be switched so that the acoustic generator 310 for measurement is short-circuited.

[0056] Without changing the position of the measuring device 350 that measures the target measurement signal Ps, the sound wave generated by vibrating the measurement vibration member 329 by the first vibration unit 101 based on the measurement acoustic signal S, or the vibration of the measurement vibration member 329 is measured by the measuring device 350 to measure the corresponding measurement signal Pv1. The characteristic creation unit 340 derives the corresponding sound pressure transfer function Hv1 between the measurement acoustic signal S and the corresponding measurement signal Pv1, and derives the filter characteristic G of the first correction filter 131 based on the previously derived target sound pressure transfer function Hs according to the following formula.

[0057] Hs = Ps / S Hv1 = Pv1 / S Inverse function calculation: Hs×S + Hv1×G1×S = 0 From the above: G1 = -Hs / Hv1

[0058] Next, the first changeover switch 371 and the fourth changeover switch 374 are switched so that the second vibration unit 102 of the measurement vibrator 320 vibrates the measurement vibration member 329 based on the measurement acoustic signal S (see FIG. 7). At this time, the third changeover switch 373 is switched so that the first vibration unit 101 is short-circuited. The second changeover switch 372 may be switched so that the measurement acoustic signal generator 310 is short-circuited.

[0059] Without changing the position of the measuring device 350 that measures the target measurement signal Ps, the sound wave generated by vibrating the measurement vibration member 329 by the second vibration unit 102 based on the measurement acoustic signal S, or the vibration of the measurement vibration member 329 is measured by the measuring device 350 to measure the corresponding measurement signal Pv2. The characteristic creation unit 340 derives the corresponding sound pressure transfer function Hv2 between the measurement acoustic signal S and the corresponding measurement signal Pv2, and derives the second filter characteristic G2 of the second correction filter 132 based on the previously derived target sound pressure transfer function Hs according to the following formula.

[0060] Hs = Ps / S Hv2 = Pv2 / S Inverse function calculation: Hs×S + Hv2×G2×S = 0 From the above: G2 = -Hs / Hv2

[0061] By setting the first filter characteristic G1 of the first correction filter 131 and the second filter characteristic G2 of the second correction filter 132 created by the characteristic creation unit 340 in the first correction filter 131 and the second correction filter 132 provided in the acoustic system 100, the acoustic system 100 can be manufactured.

[0062] When measuring the target measurement signal Ps, the following effects can be obtained by short-circuiting the first vibration unit 101 and the second vibration unit 102 of the measurement exciter 320. That is, the measurement vibration member 329 vibrates due to the sound wave generated by the measurement acoustic generator 310, and an induced current is generated in the internal wiring of the measurement exciter 320 due to the vibration. The generated induced current consumes electrical energy by the internal resistance of each of the first vibration unit 101 and the second vibration unit 102. Due to the consumption of this electrical energy, the first vibration unit 101 and the second vibration unit 102 behave as if the attenuation of the mechanical vibration system has increased. This state is the same as the state in which the exciter 120 suppresses the vibration of the vibration member 220 due to the sound wave generated by the acoustic generator 110 in the acoustic system 100, improving the accuracy of the first filter characteristic G1 and the second filter characteristic G2 derived by the characteristic creation system 300, and effectively suppressing the amount of the sound wave generated by the acoustic generator 110 that passes through the vibration member 220.

[0063] Note that the present invention is not limited to the above-described embodiments. For example, another embodiment realized by arbitrarily combining the components described in this specification and excluding some of the components may also be an embodiment of the present invention. Further, modification examples obtained by making various modifications conceivable by those skilled in the art without departing from the gist of the present invention, that is, the meaning indicated by the language described in the claims with respect to the above-described embodiments, are also included in the present invention.

[0064] For example, as shown in FIG. 9, the vibrator 120 may include a third vibration unit 103 in addition to the first vibration unit 101 and the second vibration unit 102 in one regulating member 109. When the vibrator 120 includes three vibration units, it becomes possible to generate moments about all axes in a plane parallel to the regulating member 109.

[0065] Also, as shown in FIG. 10, the vibrator 120 may include a fourth vibration unit 104 in one regulating member 109 in addition to the first vibration unit 101, the second vibration unit 102, and the third vibration unit 103, and five or more vibration units may be attached to the regulating member 109. When four or more vibration units are provided, it becomes possible to easily generate moments about all axes in a plane parallel to the regulating member 109. Further, the four or more vibration units may be arranged at positions equivalent to the positional relationship between the sun gear and the planet gears in the planetary gear mechanism. For example, the first vibration unit 101 may be arranged at the center position of the regulating member 109, and the second vibration unit 102, the third vibration unit 103, and the fourth vibration unit 104 may be arranged circumferentially around the outside of the first vibration unit 101. In this case, the vibrator 120 can easily generate a moment capable of exciting a vibration mode having a concentric pitch line centered on the first vibration unit 101 on the vibration member 220. Further, the four or more vibration units may be arranged at three-dimensional positions that are not on the same plane.

[0066] Also, although the case where the acoustic system 100 is manufactured by setting the filter characteristics derived based on the characteristic creation system 300 in the first correction filter 131 and the second correction filter 132 has been illustrated, the filter characteristics of the first correction filter 131 and the filter characteristics of the second correction filter 132 are derived by numerical analysis simulations such as FEM (finite element method) and LEM (equivalent circuit analysis method using lumped constant elements), and the first correction filter 131 and the second correction filter 132 of the acoustic system 100 may be set.

[0067] Also, the case where the target measurement signal Ps and the corresponding measurement signal Pv are measured by the measurement device 350 in which they are arranged in one place, and the first filter characteristic G1 for the first correction filter 131 and the second filter characteristic G2 for the second correction filter 132 are derived has been described. However, a plurality of measurement devices 350 may be arranged at a plurality of locations, or the measurement device 350 may be moved to measure a plurality of target measurement signals Ps and a plurality of corresponding measurement signals Pv1, Pv2, and the first filter characteristics G1, G2 may be derived based on these. In this case, the first filter characteristics G1, G2 may be derived using one target measurement signal Ps and one corresponding measurement signal Pv respectively calculated by subjecting the plurality of target measurement signals Ps and the plurality of corresponding measurement signals Pv1, Pv2 to statistical processing such as the least squares method.

[0068] Also, the case where the acoustic system operates based on an acoustic signal reproduced in real time has been described. However, a signal obtained by passing or convolving the original acoustic signal through a correction filter and a signal obtained by adding a fixed delay corresponding to the correction filter to the original acoustic signal may be prepared in advance in the storage device, and both may be reproduced synchronously, with the former supplied to the vibrator and the latter supplied to the acoustic generator.

[0069] Also, the case where the characteristic creation system 300 arranges the second changeover switch 372, the third changeover switch 373, and the fourth changeover switch 374 on the output terminal side of the first measurement amplifier 361, the second measurement amplifier 362, and the third measurement amplifier 363 has been described. However, they may be arranged on the input terminal side. In this case, if a voltage drive type amplifier with a sufficiently low output impedance is used as the measurement amplifier, the same effect as short-circuiting the changeover switch arranged on the output terminal side can be obtained by short-circuiting the measurement amplifier input terminal to the ground potential.

[0070] The vibrator 120 according to the first aspect of the present disclosure includes a first vibration unit 101 that generates a vibration force applied to the attached vibration member 220, a second vibration unit 102 that is attached to the vibration member 220 and generates a vibration force applied to the vibration member 220, and a regulation member 109 to which the first vibration unit 101 and the second vibration unit 102 are fixed and that regulates the relative movement between the first vibration unit 101 and the second vibration unit 102.

[0071] According to the first aspect, a moment can be given to the vibration member 220 as one of the vibration forces, and even when the vibrator 120 is located at a node of a wave, it is possible to generate the wave in the vibration member 220.

[0072] The vibrator 120 according to the second aspect includes the first aspect, and a first correction filter that corrects the acoustic signal 201 and outputs it to the first vibration unit 101, and a second correction filter that corrects the acoustic signal 201 and outputs it to the second vibration unit 102.

[0073] According to the second aspect, the vibration member 220 can be appropriately vibrated with respect to the acoustic signal 201.

[0074] The acoustic system 100 according to the third aspect includes the vibrator 120 according to the second aspect, and an acoustic generator 110 that generates sound waves based on the acoustic signal 201. The first correction filter 131 and the second correction filter 132 correct the acoustic signal 201 so as to reduce the transmitted sound through which the sound waves pass through the vibration member 220, and output them to the first vibration unit 101 and the second vibration unit 102, respectively.

[0075] According to the third aspect, the amount of sound waves generated by the acoustic generator 110 passing through the vibration member 220 can be reduced by the vibration of the vibrator 120.

[0076] The acoustic system 100 according to the fourth aspect includes the third aspect, and includes a delay filter that delays the acoustic signal 201 and outputs it to the acoustic generator 110.

[0077] According to the fourth aspect, it is possible to effectively reduce the amount of sound passing through the vibration member 220 by correcting a delay caused by, for example, a difference between the path through which the acoustic signal 201 output to the acoustic generator 110 passes and the path through which the acoustic signal 201 output to the vibrator 120 passes.

[0078] The acoustic system 100 of the fifth aspect includes the third aspect or the fourth aspect, and includes a common filter that corrects both the acoustic signal 201 output to the vibrator 120 and the acoustic signal 201 output to the acoustic generator 110.

[0079] According to the fifth aspect, it is possible to cut signal components that cannot be completely reduced by the vibration of the vibration member 220 by the vibrator 120, and suppress the amount of sound passing through the vibration member 220.

[0080] The acoustic system 100 of the sixth aspect includes any one of the third aspect to the fifth aspect. Each of the first correction filter 131 and the second correction filter 132 has filter characteristics derived based on a target sound pressure transfer function between a target measurement signal obtained by measuring at least one of a sound wave generated by the acoustic generator 110 based on the acoustic signal 201 and the vibration of the vibration member 220 caused by the sound wave generated by the acoustic generator 110, and the acoustic signal 201, on the side of the vibration member 220 where the acoustic generator 110 is not placed.

[0081] According to the sixth aspect, it is possible to introduce the first correction filter 131 and the second correction filter 132 that conform to the actual situation into the acoustic system 100, and effectively suppress the amount of sound passing through the vibration member 220.

[0082] The acoustic system 100 of the seventh aspect includes the sixth aspect. The first correction filter 131 has first filter characteristics derived based on the first corresponding sound pressure transfer function between the sound wave generated by vibrating the vibration member 220 by the vibrator 120 based on the acoustic signal 201 and at least one of the vibrations, and the first corresponding measurement signal obtained by measuring at least one of the sound wave and the vibrations at the position where the target measurement signal is measured. The second correction filter 132 has second filter characteristics derived based on the second corresponding sound pressure transfer function between the sound wave generated by vibrating the vibration member 220 by the vibrator 120 based on the acoustic signal 201 and at least one of the vibrations, and the second corresponding measurement signal obtained by measuring at least one of the sound wave and the vibrations at the position where the target measurement signal is measured.

[0083] According to the seventh aspect, the acoustic system 100 can include the first correction filter 131 and the second correction filter 132 with filter characteristics that correctly reflect the actual state, and can effectively suppress the transmission of the sound wave generated by the acoustic generator 110 when the vibrator 120 vibrates the vibration member 220.

[0084] The acoustic system control method of the eighth aspect is an acoustic system control method for setting the filter characteristics of the correction filter included in the acoustic system 100 according to any one of the third aspect to the seventh aspect. The acoustic generator 110 is arranged on one side of the vibration member 220 to which the vibrator 120 is attached, the measuring device is arranged on the other side of the vibration member 220, and at least one of the sound wave generated by the acoustic generator 110 based on the acoustic signal 201 and the vibration of the vibration member 220 caused by the sound wave generated by the acoustic generator 110 is measured by the measuring device to obtain a target measurement signal, and the filter characteristics of the correction filter are set based on the target sound pressure transfer function between the acoustic signal 201 and the target measurement signal.

[0085] According to the eighth aspect, the amount of the sound wave generated by the acoustic generator 110 passing through the vibration member 220 can be suppressed.

[0086] The method for manufacturing an acoustic system according to the ninth aspect includes the eighth aspect, and measures, using a measuring device, a sound wave generated by vibrating a vibrating member 220 by a first vibration unit 101 based on an acoustic signal 201 at a position where a target measurement signal is measured, to obtain a first corresponding measurement signal, sets first filter characteristics of a first correction filter 131 based on a first corresponding sound pressure transfer function between the acoustic signal 201 and the first corresponding measurement signal, measures, using the measuring device, a sound wave generated by vibrating the vibrating member 220 by a second vibration unit 102 based on the acoustic signal 201 at the position where the target measurement signal is measured, to obtain a second corresponding measurement signal, and sets second filter characteristics of a second correction filter 132 based on a second corresponding sound pressure transfer function between the acoustic signal 201 and the second corresponding measurement signal.

[0087] According to the ninth aspect, an acoustic system 100 including a correction filter 130 with filter characteristics that correctly reflect the actual state can be manufactured.

[0088] The method for manufacturing an acoustic system according to the tenth aspect includes the eighth aspect or the ninth aspect, and obtains a target measurement signal in a state where at least one of the first vibration unit 101 and the second vibration unit 102 in the vibrator 120 is short-circuited.

[0089] According to the tenth aspect, high-precision first filter characteristics G1 and second filter characteristics G2 can be generated.

[0090] The method for manufacturing an acoustic system according to the eleventh aspect includes any one of the eighth aspect to the tenth aspect, and sets filter characteristics of the first correction filter 131 and the second correction filter 132 based on a processing sound pressure transfer function between a processing signal obtained by statistically processing target measurement signals measured at a plurality of different positions and the acoustic signal 201.

[0091] According to the eleventh aspect, the sound transmitted through the vibrating member 220 can be captured in terms of a plane, and the transmitted sound in a desired region can be effectively suppressed.

[0092] The method for manufacturing an acoustic system according to the twelfth aspect is a method for manufacturing an acoustic system 100 according to any one of the third aspect to the seventh aspect, wherein an acoustic generating device 110 is arranged on one side of a vibration member 220 to which a vibrator 120 is attached, a measuring device is arranged on the other side of the vibration member 220, and at least one of the sound wave generated by the acoustic generating device 110 based on the acoustic signal 201 and the vibration of the vibration member 220 caused by the sound wave generated by the acoustic generating device 110 is measured by the measuring device to obtain a target measurement signal, and the filter characteristics of the correction filter are set based on the target sound pressure transfer function between the acoustic signal 201 and the target measurement signal.

[0093] According to the twelfth aspect, it is possible to manufacture an acoustic system 100 capable of suppressing the amount of the sound wave generated by the acoustic generating device 110 passing through the vibration member 220.

[0094] The method for manufacturing an acoustic system according to the thirteenth aspect includes the twelfth aspect, and at the position where the target measurement signal is measured, the sound wave generated by vibrating the vibration member 220 by the first vibration unit 101 based on the acoustic signal 201 is measured by the measuring device to obtain a first corresponding measurement signal, and the first filter characteristics of the first correction filter 131 are set based on the first corresponding sound pressure transfer function between the acoustic signal 201 and the first corresponding measurement signal, and at the position where the target measurement signal is measured, the sound wave generated by vibrating the vibration member 220 by the second vibration unit 102 based on the acoustic signal 201 is measured by the measuring device to obtain a second corresponding measurement signal, and the second filter characteristics of the second correction filter 132 are set based on the second corresponding sound pressure transfer function between the acoustic signal 201 and the second corresponding measurement signal.

[0095] According to the thirteenth aspect, it is possible to manufacture an acoustic system 100 provided with a correction filter 130 having filter characteristics that correctly reflect the actual state.

[0096] The method for manufacturing an acoustic system according to the fourteenth aspect includes the twelfth aspect or the thirteenth aspect, and a target measurement signal is obtained in a state where at least one of the first vibration unit 101 and the second vibration unit 102 in the vibrator 120 is short-circuited.

[0097] According to the fourteenth aspect, high-precision first filter characteristics G1 and second filter characteristics G2 can be generated.

[0098] The method for manufacturing an acoustic system according to the fifteenth aspect includes any one of the twelfth aspect to the thirteenth aspect, and sets the filter characteristics of the first correction filter 131 and the second correction filter 132 based on the processing sound pressure transfer function between the processing signal obtained by statistically processing the target measurement signals measured at a plurality of different positions and the acoustic signal 201.

[0099] According to the fifteenth aspect, the sound transmitted through the vibrating member 220 can be captured on a surface, and the transmitted sound in a desired region can be effectively suppressed.

Industrial Applicability

[0100] The present disclosure can be used in a moving body, a building, etc. having a space in which it is desired to suppress the amount of sound waves generated in the first space from passing through the vibrating member 220 and leaking into the second space.

Explanation of Reference Numerals

[0101] 100 Acoustic system 101 First vibration unit 102 Second vibration unit 103 Third vibration unit 104 Fourth vibration unit 109 Regulation member 110 Acoustic generator 120 Vibrator 121 Magnet 122 Top plate 123 Bottom plate 124 Voice coil 125 Bobbin 126 Mounting member 127 Suspension 128 Flange portion 129 Magnetic gap 130 Correction filter 131 First correction filter 132 Second correction filter 140 Delay filter 150 Common filter 161 First drive amplifier 162 Second drive amplifier 163 Third drive amplifier 200 Signal source 201 Acoustic signal 210 Moving body 211 First space 212 Second space 213 Interior space of vehicle 220 Vibration member 300 Characteristic creation system 310 Acoustic generating device for measurement 311 First measurement space 312 Second measurement space 313 Interior space of vehicle 320 Vibration exciter for measurement 329 Vibration member for measurement 330 Sound source for measurement 340 Characteristic creation unit 350 Measuring device 361 First measurement amplifier 362 Second measurement amplifier 363 Third measurement amplifier 371 First switching switch 372 Second switching switch 373 Third switching switch 374 Fourth switching switch G1 First filter characteristic G2 Second filter characteristic Hs Target sound pressure transfer function Ps Target measurement signal Hv1 Corresponding sound pressure transfer function Hv2 Corresponding sound pressure transfer function Pv1 Corresponding measurement signal Pv2 Corresponding measurement signal

Claims

1. A first vibration unit that generates a vibration force applied to an attached vibration member; A second vibration unit that is attached to the vibration member and generates a vibration force applied to the vibration member; A regulating member to which the first vibration unit and the second vibration unit are fixed and that regulates relative movement between the first vibration unit and the second vibration unit; A vibrator comprising the same.

2. A first correction filter that corrects an acoustic signal and outputs the corrected signal to the first vibration unit; A second correction filter that corrects the acoustic signal and outputs the corrected signal to the second vibration unit; The vibrator according to claim 1, comprising the same.

3. The vibrator according to claim 2; An acoustic generating device that generates sound waves based on the acoustic signal; and The first correction filter and the second correction filter correct the acoustic signal so as to reduce transmitted sound through which the sound waves pass through the vibration member and output the corrected signal to the first vibration unit and the second vibration unit, respectively An acoustic system.

4. A delay filter that delays the acoustic signal and outputs the delayed signal to the acoustic generating device The acoustic system according to claim 3, comprising the same.

5. A common filter that corrects both the acoustic signal output to the vibrator and the acoustic signal output to the acoustic generating device The acoustic system according to claim 3 or 4, comprising the same.

6. Each of the first correction filter and the second correction filter On a side of the vibration member where the acoustic generator is not placed, it has filter characteristics derived based on a target sound pressure transfer function between a target measurement signal obtained by measuring at least one of a sound wave generated by the acoustic generator based on an acoustic signal and vibration of the vibration member caused by the sound wave generated by the acoustic generator, and the acoustic signal. The acoustic system according to claim 3 or 4.

7. The first correction filter has first filter characteristics derived based on a first corresponding sound pressure transfer function between a first corresponding measurement signal obtained by measuring at least one of a sound wave generated by the shaker vibrating the vibration member based on an acoustic signal and the vibration at a position where the target measurement signal is measured, and the acoustic signal. The second correction filter has second filter characteristics derived based on a second corresponding sound pressure transfer function between a second corresponding measurement signal obtained by measuring at least one of a sound wave generated by the shaker vibrating the vibration member based on an acoustic signal and the vibration at a position where the target measurement signal is measured, and the acoustic signal. The acoustic system according to claim 6.

8. An acoustic system control method for setting filter characteristics of a correction filter included in the acoustic system according to claim 3 or 4, arranging an acoustic generator on one side of a vibration member to which a shaker is attached, arranging a measuring device on the other side of the vibration member, causing the measuring device to measure at least one of a sound wave generated by the acoustic generator based on an acoustic signal and vibration of the vibration member caused by the sound wave generated by the acoustic generator to obtain a target measurement signal, setting filter characteristics of a correction filter based on a target sound pressure transfer function between the acoustic signal and the target measurement signal Acoustic system control method.

9. At the position where the target measurement signal is measured, the measuring device measures the sound wave generated by vibrating the vibrating member by the first vibration unit based on the acoustic signal to obtain a first corresponding measurement signal. Set the first filter characteristic of the first correction filter based on the first corresponding sound pressure transfer function between the acoustic signal and the first corresponding measurement signal. At the position where the target measurement signal is measured, the measuring device measures the sound wave generated by vibrating the vibrating member by the second vibration unit based on the acoustic signal to obtain a second corresponding measurement signal. Set the second filter characteristic of the second correction filter based on the second corresponding sound pressure transfer function between the acoustic signal and the second corresponding measurement signal. The acoustic system control method according to claim 8.

10. Obtain the target measurement signal in a state where at least one of the first vibration unit and the second vibration unit in the vibrator is short-circuited. The acoustic system control method according to claim 8 or claim 9.

11. Set the filter characteristics of the first correction filter and the second correction filter based on the processing sound pressure transfer function between the processing signal obtained by statistically processing the target measurement signals measured at a plurality of different positions and the acoustic signal. The acoustic system control method according to claim 8 or claim 9.

12. An acoustic system manufacturing method for manufacturing the acoustic system according to claim 3 or 4, Arrange an acoustic generating device on one side of the vibrating member to which the vibrator is attached. Arrange a measuring device on the other side of the vibrating member. The measuring device measures at least one of the sound wave generated by the acoustic generating device based on the acoustic signal and the vibration of the vibrating member caused by the sound wave generated by the acoustic generating device to obtain a target measurement signal. Set the filter characteristic of the correction filter based on the target sound pressure transfer function between the acoustic signal and the target measurement signal. Method for manufacturing an audio system.

13. At the position where the target measurement signal is measured, causing the measurement device to measure the sound wave generated by vibrating the vibration member by the first vibration unit based on the acoustic signal, and obtaining a first corresponding measurement signal; Setting the first filter characteristics of the first correction filter based on the first corresponding sound pressure transfer function between the acoustic signal and the first corresponding measurement signal; At the position where the target measurement signal is measured, causing the measurement device to measure the sound wave generated by vibrating the vibration member by the second vibration unit based on the acoustic signal, and obtaining a second corresponding measurement signal; Setting the second filter characteristics of the second correction filter based on the second corresponding sound pressure transfer function between the acoustic signal and the second corresponding measurement signal The method for manufacturing an audio system according to claim 12.

14. Obtaining the target measurement signal in a state where at least one of the first vibration unit and the second vibration unit in the vibrator is short-circuited The method for manufacturing an audio system according to claim 12 or claim 13.

15. Setting the filter characteristics of the first correction filter and the second correction filter based on the processing sound pressure transfer function between the processing signal obtained by statistically processing the target measurement signals measured at a plurality of different positions and the acoustic signal The method for manufacturing an audio system according to claim 12 or claim 13.

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