Acoustic devices for impact products
The acoustic device in percussion products adjusts the resonant frequency of the acoustic membrane using piezoelectric elements and electrical circuits to enhance sound quality and clarity, addressing the limitations of existing mechanical frequency adjustment methods.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- DE LA MFG DHORLOGERIE AUDEMARS PIGUET & CIE
- Filing Date
- 2024-06-18
- Publication Date
- 2026-07-21
AI Technical Summary
Existing percussion products, such as time-striking watches, suffer from suboptimal sound quality due to acoustic films not fully resonating under forced conditions and reliance on mechanical mechanisms for frequency adjustment, which affects sound amplification and clarity.
An acoustic device comprising a piezoelectric element and electrical circuit that adjusts the resonant frequency of an acoustic membrane to match the frequency of the gong, using multiple electrodes and switches to optimize sound production, allowing for both amplification and muting modes.
Enhances sound quality and clarity by aligning the resonant frequency of the acoustic membrane with the gong's frequency, providing improved acoustic intensity and the ability to mute sounds as needed.
Smart Images
Figure 2026524189000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to an acoustic device for a percussion product having a film capable of adjusting a resonance frequency by a piezoelectric effect. The present invention also relates to a percussion product provided with such an acoustic device, particularly to watches in general.
Background Art
[0002] Percussion products, particularly time-striking (hour-striking) watches, such as grande sonnerie or minute repeater, are well known. For example, Patent Document 1 (CH714635) and Patent Document 2 (EP2942675) disclose an hour-striking watch provided with a watch case for housing an acoustic film and a watch movement provided with an hour-striking mechanism. This mechanism includes at least one gong and one hammer for striking the gong. The sound generated by the hammer colliding with the gong vibrates the gong and the film, which contributes to the transmission of sound between the inside and outside of the watch case.
[0003] The drawback of the above watch is that the acoustic film is operated under forced conditions and does not resonate. Therefore, the film does not fully exert its potential.
[0004] Also, there are watches provided with an acoustic film with a piezoelectric element in order to adjust the resonance frequency of the acoustic film. For example, Patent Document 3 (FR2466903) discloses a mechanical watch provided with an assembly including an acoustic film and a piezoelectric element. The piezoelectric element is controlled by an electronic circuit in order to vibrate the acoustic film to generate an audible sound in a certain operation mode. This watch further includes a mechanism for adjusting the resonance frequency of the acoustic film. This mechanism is a rotating arm installed at the bottom of the case and in contact with the film, and includes a rotating arm that is movable to adjust the resonance frequency of the film. Thereby, the frequency of the assembly of the film and the piezoelectric element can be changed for sound amplification.
[0005] The drawback of the aforementioned mechanical watch lies in the sound quality emitted, which partially depends on the characteristics of the acoustic film.
Prior Art Documents
[0006] [Patent Document 1] Swiss Patent No. 714635 [Patent Document 2] European Patent Application Publication No. 2942675 [Patent Document 3] French Patent No. 2466903 [Overview of the project] [Problems that the invention aims to solve]
[0007] Therefore, the object of the present invention is to propose an acoustic device for percussion products that can produce sounds with improved sound quality.
[0008] Another object of the present invention is therefore to provide an acoustic device for percussion products that can reduce the amplitude of sound in order to obtain a mute mode. [Means for solving the problem]
[0009] At least some of these objectives are achieved by acoustic devices, particularly for percussion products. The device comprises an acoustic membrane, at least one piezoelectric element positioned to cooperate with the acoustic membrane, and at least one electrical circuit incorporating the piezoelectric element (particularly by multiple electrodes of the piezoelectric element). These electrodes may typically be formed by their maximum surface area. The acoustic device further comprises at least one gong that can be struck with a hammer. The assembly comprising the piezoelectric element and the electrical circuit is configured to tune the resonant frequency of its (acoustic) membrane according to the resonant frequency of at least one gong.
[0010] In one embodiment, each piezoelectric element is arranged to be in direct contact with the acoustic film and preferably has a shape that is at least partially complementary to the shape of the acoustic film.
[0011] In one embodiment, the acoustic film is circular. The piezoelectric element is circular or partially circular.
[0012] In one embodiment, at least one piezoelectric element is at least partially ring-shaped. The piezoelectric element is positioned along at least a portion of the periphery of the acoustic film to modulate its resonant frequency when the acoustic film is subjected to a radial tensile force by at least one piezoelectric element.
[0013] In one embodiment, at least one surface of the acoustic film is covered by at least one piezoelectric element that occupies at least 70%, preferably at least 80%, or even at least 90% of the surface area of that surface.
[0014] In one embodiment, the acoustic device includes at least one piezoelectric element configured to be driven by a power source incorporated into an electrical circuit for operation in active mode.
[0015] In one embodiment, the power source is one or more piezoelectric elements of the acoustic device.
[0016] In one embodiment, the acoustic device further comprises a peripheral element that contacts the acoustic film at its periphery. A piezoelectric element is incorporated into the peripheral element, and the expansion or contraction of the piezoelectric element causes tensile vibration of the acoustic film that changes the resonant frequency of the acoustic film.
[0017] In one embodiment, the acoustic device comprises a plurality of gongs. One electrical circuit is assigned to each gong, and the electrical circuit has a unique characteristic that allows for adjustment of the resonant frequency of the membrane according to the resonant frequency of the gong to which the electrical circuit is assigned.
[0018] In one embodiment, the acoustic device comprises a plurality of gongs. One piezoelectric element is assigned to each gong, and each piezoelectric element has a unique property that allows for adjustment of the resonant frequency of the film according to the resonant frequency of the gong to which the piezoelectric element is assigned.
[0019] In one embodiment, at least one electrical circuit includes a switch configured to open and close in order to individually operate or disconnect an electrical circuit in which at least one piezoelectric element is incorporated.
[0020] In one embodiment, an assembly including a piezoelectric element and an electrical circuit is configured to further shift and separate the resonance frequency of the film and the resonance frequency of the gong.
[0021] Another aspect of the present invention relates to a striking clock including an acoustic device and one hammer arranged to strike the gong of the acoustic device.
[0022] Another aspect of the present invention relates to a striking clock including an acoustic device provided with a plurality of hammers, the plurality of hammers being arranged to strike corresponding gongs. The switch is actuated by the movement of the hammer or a striking release member.
[0023] In one embodiment, at least one piezoelectric element is disposed on one surface of an acoustic film facing one of the gongs.
[0024] Multiple examples of embodiments of the present invention are shown in the description presented in the following attached drawings.
Brief Description of the Drawings
[0025] [Figure 1] FIG. 1 shows a perspective view of an acoustic device intended for attachment to a striking clock, related to a gong, according to one embodiment. [Figure 2] FIG. 2 shows an equivalent circuit of a control circuit including a piezoelectric element and a switch. [Figure 3] FIG. 3 schematically shows a watch case of a striking clock containing an acoustic device according to the embodiment shown in FIG. 1 or any of the embodiments described below. [Figure 4a] FIGS. 4a and 4b show one of two circuits incorporating piezoelectric elements according to two embodiments. [Figure 4b] FIG. 4b shows the other of two circuits incorporating piezoelectric elements according to two embodiments. [Figure 5] Figure 5 shows a plan view of Figure 1 with an added electrical circuit diagram showing a power source in an embodiment incorporating a modified example. [Figure 6] Figure 6 is a plan view of a clock sound device according to another embodiment incorporating a modified example. [Figure 7] Figure 7 is a cross-sectional view of the acoustic device shown in Figure 6. [Figure 8] Figure 8 is a plan view of a clock sound device according to another embodiment with a separate gong. [Figure 9] Figure 9 is a cross-sectional view of Figure 8. [Figure 10] Figure 10 shows a schematic diagram of a clock sound device according to another embodiment. [Figure 11] Figure 11 is a graph showing the resonant frequencies of the clock gong and the acoustic membrane when the amplitude of the sound produced by the gong-membrane-electrical circuit assembly is in the attenuation mode, the suboptimal mode, and the optimal mode. [Modes for carrying out the invention]
[0026] In one embodiment, referring to Figures 1 and 3, the sound device 10 is intended to be attached to a percussive product. The term “percussive product” refers to a device that produces sound or plays music by striking (for example, a striker clock, a music box, an automatic device, or any other mechanical or semi-mechanical device designed to produce both or either chimes and music). Embodiments illustrated herein refer to striking clocks, without limitation.
[0027] This clock may be a grand sonnerie or minute repeater and may have one or more gongs 12, 14. Typically, the device 10 functions particularly as a partition, dividing the internal chamber 6 of the clock to form a sealed housing 16 and an acoustic cavity 8. The housing 16 houses a watch movement with a striking mechanism. The acoustic cavity 8 has through holes 9 through which the sound generated by the striking mechanism is diffused from the inside to the outside of the watch case 100.
[0028] The acoustic device 10, in this example, is generally in the shape of a vessel and has a rim that forms a mounting flange 11. The central part of the partition forms an acoustic film 20, on which, as shown in Figure 1, for example, a first piezoelectric element 30a and a second piezoelectric element 30b are arranged. The acoustic film 20 is made of, for example, titanium. Titanium has the advantage of having a relatively low modulus of elasticity, making it ideal for the transmission of acoustic waves. Alternatively, a sapphire film may be used for aesthetic reasons. This allows the watch operator (especially when operating the striking mechanism) to see, at least partially, the watch movement on the back cover side of the watch case.
[0029] In the example shown in Figure 1, the sound device 10 further comprises a sabot 15 rigidly attached to a mounting flange 11, to which a first gong 12 and a second gong 14 are mounted. The first gong 12 and the second gong 14 are intended to be struck, respectively, by a first and second hammer of the clock's striking mechanism (not shown). Through this arrangement, the component, as a single unit, can typically produce two sounds of different tones, a low tone and a high tone. The sound device 10 is particularly adaptable to minute repeater clocks, which, according to the user's requirements, can announce the hours with a low tone, 15-minute intervals with a sequence of high and low tones, and minutes with a high tone.
[0030] The sabot 15, or the assembly consisting of gongs 12, 14 and sabot 15, does not necessarily constitute part of the sound device 10. Preferably, the sound device 10 is Acoustic membrane and, At least one piezoelectric element positioned to work in cooperation with the (acoustic) membrane, At least one electrical circuit incorporating that piezoelectric element, A frame for securing this sound device near the watch's striking mechanism (which has at least one gong) and inside the watch case. It simply provides this. This frame is adapted to support the various elements of the acoustic device mentioned above.
[0031] In a modified example not shown, the clock equipped with the sound device 10 would have only a single gong. In another variation not shown, the clock with the sound device 10 would have more than two gongs (e.g., three, four, or five gongs). This type of clock is called a carillon and features three, four, or five chime sequences (sets of bells) that sound at different frequencies, such as three, four, or five tones. This device would therefore require more gongs and hammers, namely three, four, or five in the most melodic models.
[0032] In the embodiment shown in Figure 1, the acoustic device 10 further comprises a first electrical circuit and a second electrical circuit, each of which is combined with a first piezoelectric element 30a and a second piezoelectric element 30b, respectively. Thus, this (acoustic) device 10 is adapted for a clock having two gongs 12 and 14.
[0033] To maximize the amplitude of the mechanical stress applied to the acoustic film 20 by the two piezoelectric elements 30a and 30b, at least one surface of the acoustic film is covered by these two piezoelectric elements, covering at least 70%, preferably at least 80%, or even at least 90% of the surface area of that surface. In an embodiment not shown, a single piezoelectric element is placed on one surface of the acoustic film and covers the film in the proportions described above.
[0034] The piezoelectric elements or each piezoelectric element 30a, 30b preferably have a shape that is at least partially complementary to the shape of the acoustic film. The acoustic film 20 is circular, and the piezoelectric elements or each piezoelectric element 30a, 30b may be circular or partially circular. For example, as shown in Figure 1, the two piezoelectric elements 30a, 30b may each be semicircular, and each may have linear sides facing each other.
[0035] In one embodiment, the characteristics of the first electrical circuit 40a, preferably at least its impedance z, are selected based on at least one resonant frequency of the first gong 12. The selection of the impedance of the first circuit thus allows for adjustment of the resonant frequency of the film 20 by excitation of the first piezoelectric element 30a, depending on the resonant frequency of the first gong 12. Similar to the first circuit, the characteristics of the second electrical circuit 40b, preferably at least its impedance, are selected based on at least one resonant frequency of the second gong 14. The impedance of the second circuit differs from that of the first circuit, allowing for adjustment of the resonant frequency of the film 20 by excitation of the second piezoelectric element 30b, depending on the resonant frequency of the second gong 14.
[0036] As shown in Figure 5, the first electrical circuit 40a and the second electrical circuit 40b each include switches 70a and 70b, respectively, which have a mechanical coupling such that when one is open, the other is closed. These function as changeover switches. This allows the first and second electrical circuits 40a and 40b to alternately excite, accelerate, or actuate the piezoelectric element in order to adjust the resonant frequency of the acoustic diaphragm 20 according to the resonant frequency of the gong that is about to be struck by the corresponding hammer of the striking mechanism of the clock incorporating the acoustic device 10.
[0037] When the first circuit 40a is open and the second circuit 40b is closed, the excitation or operation of the first piezoelectric element 30a changes the stiffness of the acoustic film 20, modulating its resonant frequency according to the resonant frequency of the first gong 12 while the second piezoelectric element is in a non-operating state. Conversely, when the first circuit 40a is closed and the second circuit 40b is open, the excitation or operation of the second piezoelectric element 30b changes the stiffness of the acoustic film 20, thereby modulating its resonant frequency according to the resonant frequency of the first gong 12. During this time, the first piezoelectric element 30a is in a non-operating state.
[0038] This significantly increases the acoustic intensity of the sound produced by the vibrations of the first and second gongs, caused by the impact of the hammers of the gongs belonging to the clock's striking mechanism. The switches 70a and 70b of each circuit 40a and 40b are switched directly or indirectly by, for example, the movement of the clock's first and second hammers, and the stiffness of the acoustic membrane can be changed depending on which gong is about to be struck by the associated hammer. By changing at least one of the acoustic membrane's resonant frequencies to match the fundamental frequencies of the two gongs, an improvement in clarity can also be obtained.
[0039] Referring to Figure 11, the amplitude (loudness) of the sound from the gong and membrane system is optimal when the membrane's resonant frequency matches the gong's resonant frequency. While it is difficult to perfectly match the resonant frequency of the acoustic membrane to the gong's resonant frequency by adjusting its rigidity, getting as close as possible allows for a significant increase in volume.
[0040] In the alternative embodiment, the characteristics of the first electrical circuit 40a and the second electrical circuit 40b are the same, while the characteristics of the first piezoelectric element 30a and the second piezoelectric element 30b are different. This allows the resonance frequency of the acoustic film 20 to be adjusted according to the resonance frequencies of the first gong 12 and the second gong 14 by the excitation of the first circuit 40a and the second circuit 40b, respectively. The characteristics of each piezoelectric element 30a and 30b are selected individually or in combination, particularly based on characteristics such as the capacitance of the piezoelectric element, the contact area with the acoustic film, the thickness, and the mass.
[0041] In another embodiment, the characteristics of the first and second electrical circuits 40a, 40b and the characteristics of the first piezoelectric element 30a and the second piezoelectric element 30b are selected such that the excitation of the piezoelectric elements by the specific electrical circuits is adjusted to bring the resonant frequency of the acoustic film as close as possible to the resonant frequency of the timbre to which the piezoelectric elements are associated.
[0042] Generally, the selection of characteristics of the electrical circuits and piezoelectric elements related to the above-described acoustic device circuitry can be applied to acoustic devices intended for integration into the mechanism of a clock with one, three, four, or, in the case of a clock with the most melodic chimes, five gongs. In this case, the acoustic device may have three, four, or five electrical circuits associated with a common piezoelectric element, or three, four, or five separate piezoelectric elements, respectively.
[0043] More specifically, in the case of clocks and the like where the striking mechanism has only a single gong, the characteristics of the circuit, especially That impedance z and, The characteristics of the piezoelectric element (for example, the capacitance of the piezoelectric element, the contact area with the acoustic film, the thickness, and the mass, or any combination thereof) and Both or one of these is determined based on at least one of the gong's resonant frequencies. In the case of clocks and the like that, which have a striking mechanism with three, four, or five gongs, The characteristics of three, four, or five electrical circuits, The characteristics of a common piezoelectric element or each piezoelectric element associated with each gong Both or one of these are selected similarly according to the resonant frequencies of the third, fourth, and fifth gongs, respectively.
[0044] Figures 4a and 4b show two different electrical circuits incorporating piezoelectric elements, respectively. For example, the stiffness of the membrane can be changed by varying the capacitance value of the circuit in Figure 4a. In contrast, the circuit in Figure 4b is suitable for damping vibrations of the acoustic membrane 20 by dissipating the electrical energy generated within the circuit through the circuit's resistance. This allows the acoustic device 10 to be set to a silenced mode. In this mode, the user can activate a piezoelectric element (individually) or each piezoelectric element to suppress or at least dampen the sound emitted from the acoustic device using a switch, for example, implemented via a push button. In this operating mode, the stiffness of the acoustic membrane is changed so that its resonant frequency is as far away as possible from the resonant frequency of the timbre, as schematically shown in Figure 11.
[0045] In situations where piezoelectric elements or individual piezoelectric elements are used to amplify the vibration of a membrane in order to increase acoustic intensity, the acoustic device 10 may have a switch for when the user wants to disable the piezoelectric effect on the membrane in order to obtain a lower volume. In the disabled mode, sound transmission is equivalent to that of a conventional striking clock, etc. Conversely, if the user desires greater amplification, the acoustic device circuit may be equipped with a power source 60 that allows the piezoelectric elements or individual piezoelectric elements to be operated in active mode to apply greater stress to the membrane.
[0046] The power source 60 housed within the watch case can typically take the form of a battery, a micro-generator, a capacitor, or any combination of these elements. For example, a micro-generator may be installed to convert a portion of the mechanical energy resulting from the user acting on a trigger (for resetting the mainspring) intended to reset the mainspring in the barrel of the striking mechanism.
[0047] In another embodiment, referring to Figures 6 and 7, the sound device 10 is: Acoustic membrane 20 and A piezoelectric element 30 having at least a partially ring-shaped (loop-shaped) form and arranged along at least a portion of the periphery of the acoustic film 20, An acoustic membrane and an integrated frame, provided together with a mounting flange 11 for assembling the acoustic device to the watch case, or a frame constituting the mounting flange. It is equipped with.
[0048] This particular configuration allows for a change in the resonant frequency of the film 20, particularly a reduction in the resonant frequency, when the film 20 is subjected to radial stress due to the deformation of the piezoelectric element 30. Preferably, the piezoelectric element 30 is a ring mounted in its plane relative to the circular edge of the acoustic film 20. The vibration of the film 20 electrically biases the piezoelectric ring 30, and its deformation applies radial stress to the film. Preferably, for operation in active mode, the piezoelectric ring is driven by a power source 60.
[0049] According to another embodiment shown in Figures 8 and 9, the acoustic device 10 comprises an acoustic film 20 and a piezoelectric element 30c, the piezoelectric element 30c being at least partially ring-shaped and positioned along at least a portion of the periphery of the film 20. Preferably, the piezoelectric element is a ring positioned in the same or similar manner as in the previously described embodiments. The piezoelectric ring 30c may be intended to operate in either passive or active mode.
[0050] For this purpose, the acoustic device 10 further comprises at least one or more piezoelectric elements 30a, 30b arranged on the surface of the acoustic film 20, covering at least 70%, preferably at least 80%, or at least 90%, of its surface area, particularly as in the embodiment shown in Figure 1. In active mode, the piezoelectric elements 30a, 30b individually or each piezoelectric element is electrically connected to the piezoelectric ring 30c.
[0051] As a result, when the clock's striking mechanism is activated, the acoustic membrane 20 vibrates due to the vibrations generated when the hammer strikes the gong, causing each piezoelectric element 30a and 30b to generate vibration resistance, which in turn supplies power to the piezoelectric ring 30c. In active mode, a greater stress can be applied from the periphery of the acoustic membrane 20. This allows the rigidity of the acoustic membrane 20 to be varied over a wider range. Therefore, the reduction in the resonant frequency of the acoustic membrane 20 can be made greater compared to embodiments operated in passive mode.
[0052] In any of the above embodiments, the piezoelectric elements 30a and 30b may be in the form of thin layers (multiple layers) with a thickness of, for example, several tens to several hundred micrometers, typically about 0.2 mm or more. These layers are fixed to at least one surface of the acoustic film 20, preferably the gong side. The piezoelectric layers 30a and 30b are fixed, for example, by adhesive. Alternatively, the piezoelectric layers 30a and 30b are deposited by CVD or PVD. The piezoelectric layers 30a and 30b can be made from a variety of materials, particularly quartz, ferroelectric oxides, or III-V semiconductors.
[0053] Each piezoelectric element 30a, 30b, or each piezoelectric element, typically comprises two electrodes with opposite polarities. These electrodes may be plate-like, for example, plate-like, arranged on both sides of the piezoelectric element if it is in a thin-layer form.
[0054] According to another embodiment shown in Figure 10, the acoustic device 10 comprises an acoustic membrane 20 and a peripheral element 50 connected to the acoustic membrane 20 by its periphery. The peripheral element may take the form of a ring 50 that surrounds the acoustic membrane 20 and is connected to it by a fixing means 34. The acoustic device 10 also comprises a piezoelectric element 32 incorporated into the ring, the expansion of which increases the tensile force of the acoustic membrane 20 and raises its resonant frequency. Conversely, the contraction of which compresses the membrane and lowers its resonant frequency. In general, both the expansion and contraction of the piezoelectric element change the tensile force of the acoustic membrane, thereby changing its resonant frequency.
[0055] The piezoelectric element 32 may be intended to operate in passive or active mode. For example, it may be driven by the power source 60 as described above, or by at least one other piezoelectric element of the acoustic device 10.
[0056] In the illustrated embodiment, the contour of the film is circular, but it may be of other shapes. In this case, the shape and arrangement of at least one piezoelectric element on the film are adapted according to the shape in order to maximize the surface area in contact with the piezoelectric element and the film.
[0057] Various modifications may be made to the above embodiments without departing from the scope of the invention as defined in the appended claims. For example, the partition plate that functions as a frame fixed to the watch case may take on various shapes. Furthermore, as described above, the gong may be integrated with a striking mechanism located inside the watch case, rather than being the illustrated sound device.
Claims
1. Acoustic membrane (20) and At least one piezoelectric element (30; 30a, 30b; 30c; 32) is arranged to cooperate with the acoustic film (20), At least one electrical circuit (40a, 40b) incorporating the piezoelectric element In an acoustic device (10) for a sound-making product equipped with, The sound device (10) further comprises at least one gong (12, 14) that can be struck with a hammer, The assembly includes the piezoelectric element, The electrical circuits (40a, 40b) are set to adjust the resonant frequency of the film (20) according to the resonant frequency of at least one gong (12, 14). An acoustic device (10) for percussion products, characterized by the above.
2. The acoustic device (10) according to claim 1, wherein each piezoelectric element (30; 30a, 30b) is arranged in direct contact with the acoustic film (20) and preferably has a shape that is at least partially complementary to the shape of the acoustic film (20).
3. The acoustic device (10) according to claim 2, wherein the acoustic film (20) is circular, and the at least one piezoelectric element (30a, 30b, 30c) is circular or partially circular.
4. The acoustic device (10) according to claim 3, wherein the at least one piezoelectric element (30c) is at least partially ring-shaped, and is arranged along at least a portion of the periphery of the acoustic film (20) to modulate its resonant frequency when the acoustic film (20) is subjected to a radial tensile force by the at least one piezoelectric element (30c).
5. The acoustic device (10) according to any one of claims 1 to 3, wherein at least one surface of the acoustic film (20) is covered by at least one piezoelectric element that occupies at least 70%, preferably at least 80%, or at least 90% of the surface area of that surface.
6. The acoustic device (10) according to any one of claims 1 to 5, comprising at least one piezoelectric element (30; 30a, 30b; 30c; 32) configured to be driven by a power source (60) incorporated into the electrical circuit (40a, 40b) for operation in active mode.
7. The sound device (10) according to claim 6, wherein the power source (60) is one or more other piezoelectric elements of the sound device (10).
8. The acoustic film (20) is further provided with peripheral elements (50) that are in contact with the acoustic film (20) at its periphery, The acoustic device (10) according to claim 1 or 2, wherein the piezoelectric element (32) is incorporated into the peripheral element (50), and the expansion or contraction of the piezoelectric element (32) causes tensile vibration of the acoustic film (20) to change the resonant frequency of the acoustic film (20).
9. In the sound device (10) equipped with multiple gongs (12, 14), One electrical circuit is assigned to each gong. The acoustic device (10) according to any one of claims 1 to 8, wherein the one electrical circuit has a unique characteristic that allows the resonant frequency of the membrane (20) to be adjusted according to the resonant frequency of the gong to which the one electrical circuit is assigned.
10. In the sound device (10) equipped with multiple gongs (12, 14), One piezoelectric element (30a, 30b) is assigned to each gong. The acoustic device (10) according to any one of claims 1 to 9, wherein the piezoelectric element has a unique characteristic that allows the resonant frequency of the film (20) to be adjusted according to the resonant frequency of the gong to which the piezoelectric element is assigned.
11. At least one electrical circuit (40a, 40b) includes a switch (70) set to open or close to activate or disconnect the electrical circuit, each of which incorporates at least one piezoelectric element. The acoustic device (10) according to any one of claims 1 to 10.
12. The acoustic device (10) according to any one of claims 1 to 11, wherein the assembly comprising the piezoelectric element and the electrical circuit is configured to further shift and separate the resonant frequency of the membrane and the resonant frequency of the gong.
13. A striker clock comprising an acoustic device (10) according to any one of claims 1 to 8, and a hammer provided for striking the gongs (12, 14) of the acoustic device (10).
14. A striker clock comprising an acoustic device (10) according to claim 9 or 10 and claim 11, and a plurality of the hammers arranged to strike gongs corresponding to the hammers, wherein the switch (70) is activated by the movement of the hammers or by a strike release member. A striking clock.
15. The striker clock according to claim 13 or 14, wherein the at least one piezoelectric element (30; 30a, 30b; 30c; 32) is positioned on one surface of the acoustic film (20) facing one of the gongs (12, 14).