Vibration device

Abstract

The vibration device (100) of the present invention comprises a plate-shaped glass vibrator (G) and a plurality of exciters E attached to the glass vibrator (G) and generating vibrations in response to an input electrical signal. The aspect ratio La / Lb of the length of the long side (La) and the length of the short side (Lb) of a rectangle (Sq) inscribed in the glass vibrator (G) is 1.2 or more and 50 or less, and the number n of the exciters (E) and the minimum value S of the distance between the exciters (E) are min and the relationship value α(α=S min (n-1) / La) is 0.2 or more and 0.8 or less, and when n is 3 or more, the standard deviation Sσ of the distance between the exciters (E) is ave The value β divided by (β=Sσ / S ave ) is between 0 and 0.5.

Description

Technical Field

[0001] The present invention relates to a vibration device for exciting a glass resonator.

Background Art

[0002] As diaphragms for speakers and microphones, cone paper and resin are widely used. Since these materials have a large loss coefficient and are less likely to generate resonance vibration, they have good sound reproduction performance in the audible range. However, since these materials have a low sound velocity value of the material itself, when excited at high frequencies, it is difficult for the vibration of the material to follow the sound wave frequency, and splitting vibration is likely to occur. Therefore, it is particularly difficult to obtain a desired sound pressure in the high-frequency region.

[0003] On the other hand, in recent high-resolution (High-Resolution) sound sources and the like, reproduction in the high-frequency region, particularly above 20 kHz, which is difficult for the human ear to hear, is required. When the sound wave vibration in such a high-frequency region is faithfully reproduced, a stronger sense of presence can be felt, and something more appealing to the emotions can be obtained. Therefore, instead of cone paper and resin, materials such as metal, ceramics, and glass, which have a high sound velocity for propagation in the material, are being considered for use as diaphragms.

[0004] For example, as a diaphragm for a speaker, one made of a single glass sheet (Patent Document 1) or a laminated glass having a 0.5-mm-thick polybutyl-based polymer layer between two glass plates (Non-Patent Document 1) is known.

Prior Art Documents

Patent Documents

[0005] [[ID=3O]]

Patent Document 1

Non-Patent Documents

[0006]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] Generally, diaphragms for speakers and microphones are widely used in circular or elliptical shapes close to circular due to constraints such as acoustic efficiency. However, when the diaphragm is used in-vehicle, in-aircraft, or installed in a building, the installation space for the diaphragm is limited. In particular, when the installation space has an elongated shape with significantly different lengths in the vertical and horizontal directions, there has been almost no track record so far, and the sound reproduction performance and acoustic effects have not been sufficient either.

[0008] Therefore, when the lengths in the vertical and horizontal directions of the diaphragm are significantly different, it has been difficult to stably excite the diaphragm while maintaining sufficient acoustic performance.

[0009] Therefore, an object of the present invention is to provide a vibration device that can stably excite while maintaining sufficient acoustic performance even when the lengths in the vertical and horizontal directions are significantly different.

Means for Solving the Problems

[0010] As a result of intensive research by the present inventor, it has been found that the above problems can be solved by using a predetermined glass plate structure, and the present invention has been completed.

[0011] That is, the present invention is as follows. (1) A vibration device comprising a plate-shaped glass vibrator and a plurality of exciters attached to the glass vibrator that generate vibrations in response to an input electrical signal, The aspect ratio La / Lb of the length La of the long side and the length Lb of the short side of the quadrilateral inscribed in the glass vibrator is 1.2 or more and 50 or less, The number of the exciters is n, and the minimum distance between the exciters is S min , the number of exciters n and the minimum distance between exciters S min The relationship value is α(α=S min (n-1) / La), The α is 0.2 or more and 0.8 or less, When the number of exciters n is 3 or more, the standard deviation Sσ of the distance between the exciters is ave The value β divided by β (β = Sσ / S ave ) is between 0 and 0.5. (2) The loss factor of the glass vibrator at 25°C is 1 x 10 -2 The longitudinal wave sound velocity value in the thickness direction of the glass vibrator is 5.0 × 10 3 The vibration device according to (1), wherein the vibration velocity is m / s or more. (3) The vibrating device according to (1) or (2), wherein the glass vibrator includes two or more glass plates and includes a fluid layer containing a liquid between at least one pair of the glass plates. (4) The vibrating device according to any one of (1) to (3), further comprising a housing covering at least one surface of the glass vibrator, and the exciter is housed in an inner space of the housing. (5) The vibrating device according to (4), wherein one side of the exciter is fixed to the glass vibrating body and the other side is fixed to the housing. (6) The vibration device according to (4) or (5), wherein the housing has an air hole formed therein that connects the interior space of the housing with the outside of the housing. (7) The vibration device according to any one of (4) to (6), wherein a sound absorbing material is provided in the inner space of the housing. (8) The vibration device according to any one of (1) to (7), wherein the sound pressure fluctuation value in the frequency range of 200 Hz to 10 kHz is 20 dB or less. (9) The vibrating device according to any one of (1) to (8), wherein the glass vibrating body has at least a part of a concave or convex curved surface. (10) The vibrating device according to any one of (1) to (9), wherein the glass vibrating body has a reinforcing member provided along the longitudinal direction of the glass vibrating body.

Advantages of the Invention

[0012] According to the present invention, there is provided a vibration device capable of stably exciting while maintaining sufficient acoustic performance even when the longitudinal and lateral lengths of the diaphragm are greatly different.

Brief Description of the Drawings

[0013]

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Embodiments for Carrying Out the Invention

[0014] Hereinafter, based on the embodiments for carrying out the invention, the details and other features of the present invention will be described. In the following drawings, the same or corresponding members or parts are denoted by the same or corresponding reference numerals, and redundant descriptions are omitted. Also, the drawings are not intended to show the relative ratios between members or parts unless otherwise specified. Therefore, specific dimensions can be appropriately selected in light of the following non-limiting embodiments.

[0015] Also, in this specification, “~” indicating a numerical range is used to mean including the numerical values described before and after it as the lower limit value and the upper limit value.

[0016] <Configuration of the Vibration Device> FIG. 1 is a diagram schematically showing a vibration device, where (A) is a side view and (B) is a plan view seen from the front. The vibration device 100 includes a plate-shaped glass vibrator G having light transmissibility, and a plurality of exciters (vibrators) E attached to the glass vibrator G that generate vibrations in response to an input electrical signal.

[0017] The glass resonator G, although its detailed configuration will be described later, is excited by the vibration generated by the exciter E to produce sound. When viewed from the direction of arrow Va in Fig. 1(A), the glass resonator G may have translucency such that the back side sandwiching the glass resonator G can be seen through, or it may have light-shielding properties or selective light transmissivity (such as an optical filter like a band-pass filter or a surface treatment layer with a light-diffusing surface). The glass resonator G may be a single substrate or a structure of a glass plate including a plurality of substrates (details will be described later). The glass resonator G is preferably made of a material with a high longitudinal sound velocity value. For example, a single crystal such as a glass plate, translucent ceramics, or sapphire can be used.

[0018] The exciter E, although not shown in the figure, includes a coil part electrically connected to an external device, a magnetic circuit part, and a vibration excitation part connected to the coil part or the magnetic circuit part. When an electrical signal of sound from an external device is input to the coil part, vibration occurs in the coil part or the magnetic circuit part due to the interaction between the coil part and the magnetic circuit part. The vibration of this coil part or magnetic circuit part is transmitted to the vibration excitation part, and the vibration is transmitted from the vibration excitation part to the glass resonator G.

[0019] A plurality of exciters E are mounted on the glass resonator G. In this configuration example, three exciters E are mounted on one surface of the glass resonator G at intervals with respect to the longitudinal direction of the glass resonator G.

[0020] Fig. 2 is an explanatory diagram showing the shape of the glass resonator G of the vibration device 100. The glass resonator G is formed in an elongated polygonal shape in plan view. The glass resonator G in this configuration example is a pentagonal shape having five corner portions CS1 to CS5. The quadrilateral Sq inscribed in the glass resonator G shown in Fig. 2 is an elongated rectangular shape in contact with the corner portions CS1, CS2, and CS4. This quadrilateral Sq can be defined, for example, as having the longest side of the glass resonator G as the long side and being the smallest quadrilateral inscribed in the outer edge of the glass resonator G.

[0021] Here, when the length of the long side of the quadrilateral Sq inscribed in the glass resonator G is La and the length of the short side is Lb, the aspect ratio La / Lb, which is the aspect ratio of the vertical and horizontal dimensions of the quadrilateral Sq, is 1.2 or more and 50 or less. As the upper limit value of the aspect ratio, 45 or less is preferable, and 40 or less is more preferable. As the lower limit value of the aspect ratio, 5.0 or more is preferable, and 10 or more is more preferable.

[0022] Also, when the number of exciters E attached to the glass resonator G is n and the minimum value of the distance between the exciters E is S min , the relational value between the number n of the exciters E and the minimum value S of the distance between the exciters E min is defined as α (α = S min (n - 1) / La). In that case, α of the vibration device 100 is preferably 0.2 or more and 0.8 or less. As the upper limit of α, 0.75 or less is preferable, 0.7 or less is more preferable, and as the lower limit, 0.25 or more is preferable, 0.3 or more is more preferable.

[0023] In the glass resonator G shown in FIGS. 1 and 2, three exciters E1, E2, and E3 are provided, and the distances between these exciters E1, E2, and E3 are S1 (distance between E1 - E2), S2 (distance between E2 - E3), and S3 (distance between E3 - E1). Therefore, in this configuration, the number n of the exciters E = 3, and the minimum value S of the distance between the exciters E min = S1. Therefore, the relational value α between the number n of the exciters E and the minimum value S of the distance between the exciters E min is α = S1(3 - 1) / La, and this relational value α satisfies 0.2 ≤ α ≤ 0.8.

[0024] Also, when the number n of the exciters E of the vibration device 100 is 3 or more, the value β (β = Sσ / S ave ) obtained by dividing the standard deviation Sσ of the distances between the exciters E by the average value S ave is 0 or more and 0.5 or less. In this configuration, since the number n of the exciters E = 3, the standard deviation Sσ of the distances S1, S2, and S3 between the exciters E is divided by the average value S aveThe value obtained by dividing by [the relevant value] is 0 or more and 0.5 or less. That is, since the exciters E attached to the glass resonator G are arranged as evenly as possible along the longitudinal direction of the glass resonator G, the long and slender glass resonator G can be excited in a well-balanced manner, and a stable sound pressure can be output.

[0025] Figure 3 is a graph showing the relationship between the frequency and the sound pressure of the vibration device 100. The sound pressure fluctuation value w at frequencies from 200 Hz to 10 kHz obtained by vibrating the glass resonator G of the vibration device 100 is preferably 20 dB or less. The sound pressure fluctuation value w is preferably 10 dB or less, and more preferably 5 dB or less. Thus, since the sound pressure fluctuation value w at frequencies from 200 Hz to 10 kHz is below the above-mentioned limit value, high-quality sound with reduced noise is output from the glass resonator G with a uniform sound pressure. Here, by providing a plurality of exciters and controlling the input energy and the phase of the signal to each exciter so that the sound pressure level fluctuation is minimized, a stable sound pressure can be output. In particular, in the present invention, by adopting the configuration of the vibration device of the present invention, it is possible to easily and stably suppress the sound pressure fluctuation value to 20 dB or less. Incidentally, the method of controlling the input energy and the phase of the signal can be controlled using a known control device and control method such as a DSP.

[0026] According to the vibration device 100 of this configuration, by exciting a long and slender glass resonator G having a large aspect ratio, that is, having greatly different longitudinal and lateral dimensions, with a plurality of exciters E, stable and sufficient acoustic performance can be maintained. Therefore, this vibration device 100 can be suitably used as a member for electronic devices, a vibration member for the interior of transportation machinery such as vehicles, an in-vehicle / on-board speaker, and an opening member used in buildings and transportation machinery.

[0027] As the glass vibrating body G constituting the vibration device 100, it may be flat, but various shapes are used according to the shape of the installation location and the like. The glass vibrating body G may be, for example, a convex shape protruding in the plate thickness direction, a concave shape recessed in the plate thickness direction, a three-dimensional shape such as a twisted shape, or a shape in which these are appropriately combined. Further, such a three-dimensional shape may be formed into a smooth curved surface shape, or a large number of flat portions may be formed by being connected stepwise. Furthermore, it may be a shape that includes both the above-mentioned three-dimensional shape portion and the flat plate-shaped portion.

[0028] FIGS. 4(A) and 4(B) are schematic views showing vibration devices 110 and 120 each including a glass vibrating body G having a reinforcing member. A reinforcing member R may be provided on the glass vibrating body G. The reinforcing member R is formed in a rod shape and is provided along the longitudinal direction of the glass vibrating body G. By providing the reinforcing member R, the glass vibrating body G is reinforced over the longitudinal direction where particularly high strength is required. The reinforcing member R may be fixed to the exciter E as shown in FIG. 4(A), or may be provided at a position different from the exciter E as shown in FIG. 4(B). In that case, a separate reinforcing member R from the glass vibrating body G may be fixed to the glass vibrating body G, or a thick portion may be provided in a part of the glass vibrating body G and used as the reinforcing member R, and the reinforcing member R may be integrally formed with the glass vibrating body G.

[0029] Here, the glass vibrating body G will be described in more detail. <Glass Vibrating Body G> The glass vibrating body G constituting the vibration device 100, although details will be described later, has a loss factor at 25°C of 1×10 -2 or more, and a longitudinal wave sound velocity value in the plate thickness direction of 5.0×10 3 m / s or more, which is preferable. Note that a large loss factor means a large vibration damping ability.

[0030] The loss factor is calculated by the half-value width method. When the frequency width at the point where the peak value of the resonance frequency f and the amplitude h of the material drops by -3 dB (i.e., the point at the maximum amplitude -3 [dB]) is defined as W, the value represented by {W / f} is defined as the loss factor. To suppress resonance, the loss factor should be increased. That is, relatively speaking, the frequency width W becomes larger with respect to the amplitude h, meaning that the peak becomes broader.

[0031] The loss factor is an inherent value of the material, etc. For example, in the case of a single glass plate, it varies depending on its composition and relative density, etc. Note that the loss factor can be measured by a dynamic elastic modulus test method such as the resonance method.

[0032] The longitudinal wave sound velocity value refers to the velocity at which longitudinal waves propagate in the diaphragm. The longitudinal wave sound velocity value and Young's modulus can be measured by the ultrasonic pulse method described in Japanese Industrial Standard (JIS-R1602-1995).

[0033] Here, as a specific configuration for obtaining a high loss factor and a high longitudinal wave sound velocity value, the glass vibrator G preferably includes two or more glass plates, and a predetermined fluid layer is included between at least a pair of the glass plates.

[0034] (Fluid layer) The glass vibrator G can achieve a high loss factor by providing a fluid layer containing a liquid between at least a pair of glass plates. Among them, by setting the viscosity and surface tension of the fluid layer within a suitable range, the loss factor can be further increased. This is considered to be due to the fact that, unlike the case where a pair of glass plates are provided via an adhesive layer, the pair of glass plates are not fixed and continue to have the vibration characteristics of each glass plate. Note that the "fluid" as used in this specification means all substances containing a liquid, such as a liquid, a mixture of solid powder and liquid, and a solid gel (jelly-like substance) impregnated with a liquid.

[0035] The fluid layer has a viscosity coefficient at 25 °C of 1×10 -4 ~1×10 3It is Pa·s, and preferably has a surface tension at 25°C of 15 to 80 mN / m. If the viscosity is too low, it becomes difficult to transmit vibration. If it is too high, a pair of glass plates located on both sides of the fluid layer will adhere to each other and exhibit the vibration behavior of a single glass plate, making it difficult to attenuate resonant vibration. Also, if the surface tension is too low, the adhesion between the glass plates decreases and it becomes difficult to transmit vibration. If the surface tension is too high, a pair of glass plates located on both sides of the fluid layer will easily adhere to each other and exhibit the vibration behavior of a single glass plate, making it difficult to attenuate resonant vibration.

[0036] The viscosity coefficient of the fluid layer at 25°C is 1×10 -3 Pa·s or more is more preferable, and 1×10 -2 Pa·s or more is even more preferable. Also, 1×10 2 Pa·s or less is more preferable, and 1×10 Pa·s or less is even more preferable. The surface tension of the fluid layer at 25°C is more preferably 20 mN / m or more, and even more preferably 30 mN / m or more.

[0037] The viscosity coefficient of the fluid layer can be measured by a rotational viscometer or the like. The surface tension of the fluid layer can be measured by the ring method or the like.

[0038] If the vapor pressure of the fluid layer is too high, the fluid layer may evaporate and fail to function as a glass vibrator. Therefore, the fluid layer preferably has a vapor pressure at 25°C and 1 atm of 1×10 4 Pa or less, more preferably 5×10 3 Pa or less, and even more preferably 1×10 3 Pa or less. Also, when the vapor pressure is high, a seal or the like may be applied so that the fluid layer does not evaporate. At this time, it is necessary to ensure that the seal material does not interfere with the vibration of the glass vibrator.

[0039] The thinner the fluid layer is, the more preferable it is in terms of maintaining high rigidity and vibration transmission. Specifically, when the total thickness of the pair of glass plates is 1 mm or less, the thickness of the fluid layer is preferably 1 / 10 or less of the total thickness of the pair of glass plates, more preferably 1 / 20 or less, even more preferably 1 / 30 or less, still more preferably 1 / 50 or less, yet even more preferably 1 / 70 or less, and particularly preferably 1 / 100 or less. When the total thickness of the pair of glass plates exceeds 1 mm, the thickness of the fluid layer is preferably 100 μm or less, more preferably 50 μm or less, even more preferably 30 μm or less, still more preferably 20 μm or less, yet even more preferably 15 μm or less, and particularly preferably 10 μm or less. The lower limit of the thickness of the fluid layer is preferably 0.01 μm or more from the viewpoints of film-forming property and durability.

[0040] The fluid layer is preferably chemically stable, and it is preferable that the fluid layer and the pair of glass plates located on both sides of the fluid layer do not react with each other. Chemically stable means, for example, those with little alteration (degradation) by light irradiation, or those in which solidification, vaporization, decomposition, discoloration, chemical reaction with glass, etc. do not occur in at least the temperature range of -20 to 70 °C.

[0041] Specific examples of the components of the fluid layer include water, oil, organic solvents, liquid polymers, ionic liquids, and mixtures thereof. More specifically, propylene glycol, dipropylene glycol, tripropylene glycol, straight silicone oil (dimethyl silicone oil, methylphenyl silicone oil, methylhydrogen silicone oil), modified silicone oil, acrylic acid-based polymer, liquid polybutadiene, glycerin paste, fluorine-based solvent, fluorine-based resin, acetone, ethanol, xylene, toluene, water, mineral oil, and mixtures thereof, etc. Among them, it is preferable to contain at least one selected from the group consisting of propylene glycol, dimethyl silicone oil, methylphenyl silicone oil, methylhydrogen silicone oil, and modified silicone oil, and it is more preferable to have propylene glycol or silicone oil as the main component.

[0042] In addition to the above, a slurry in which powder is dispersed can also be used as a fluid layer. From the perspective of improving the loss coefficient, the fluid layer is preferably a uniform fluid. However, when imparting design properties or functionality such as coloring or fluorescence to the glass resonator, the slurry is effective. The powder content in the fluid layer is preferably 0 to 10% by volume, more preferably 0 to 5% by volume. The particle size of the powder is preferably 10 nm to 1 μm from the perspective of preventing sedimentation, and more preferably 0.5 μm or less.

[0043] Also, from the perspective of imparting design properties and functionality, a fluorescent material may be included in the fluid layer. In that case, it may be a slurry-like fluid layer in which the fluorescent material is dispersed as powder, or a uniform fluid layer in which the fluorescent material is mixed as a liquid. Thereby, optical functions such as light absorption and light emission can be imparted to the glass resonator.

[0044] FIG. 5 is a cross-sectional view showing a specific example of the glass resonator G. For the glass resonator G, it is preferable to provide at least a pair of glass plates 11 and 12 so as to sandwich the above-described fluid layer 16 from both sides. When the glass plate 11 resonates, the fluid layer 16 prevents the resonance of the glass plate 12 or attenuates the resonance vibration of the glass plate 12. Due to the presence of the fluid layer 16, the glass resonator G can increase the loss coefficient compared to the case of a single glass plate.

[0045] Since the greater the loss coefficient of the glass resonator G, the greater the vibration attenuation, it is preferable. The loss coefficient of the glass resonator G at 25°C is preferably 1×10 -2 or more, more preferably 2×10 -2 or more, even more preferably 5×10 -2 or more. Also, the longitudinal sound velocity value in the plate thickness direction of the glass resonator G is preferably 5.0×10 3 m / s or more because the higher the sound velocity, the better the reproducibility of high-frequency sound when used as a diaphragm. More preferably, it is 5.5×10 3 m / s or more, even more preferably 6.0×10 3 m / s or more. The upper limit is not particularly limited, but 7.0×10 3It is preferably below m / s.

[0046] When the linear transmittance of the glass resonator G is high, it can be applied as a translucent member. Therefore, the visible light transmittance determined in accordance with Japanese Industrial Standard (JIS R3106-1998) is preferably 60% or more, more preferably 65% or more, and even more preferably 70% or more. In addition, examples of the translucent member include applications such as transparent speakers, transparent microphones, building and vehicle opening members.

[0047] For the purpose of increasing the transmittance of the glass resonator G, it is also useful to match the refractive indices. That is, the closer the refractive indices of the glass plate and the fluid layer constituting the glass resonator G are, the more preferable it is because reflection and interference at the interface are prevented. Among them, the difference between the refractive index of the fluid layer and the refractive indices of the pair of glass plates in contact with the fluid layer is preferably 0.2 or less, more preferably 0.1 or less, and even more preferably 0.01 or less.

[0048] (Glass plate) It is also possible to color at least one of the glass plates constituting the glass resonator G and at least one of the fluid layers. This is useful when it is desired to give the glass resonator G a design property or when it is desired to give it functions such as IR cut, UV cut, and privacy glass.

[0049] Among the pair of glass plates 11 and 12, it is preferable that the values of the peak tops of the resonance frequencies of one glass plate 11 and the other glass plate 12 are different, and those with non-overlapping resonance frequency ranges are more preferable. However, even if the resonance frequency ranges of the glass plate 11 and the glass plate 12 overlap or the values of the peak tops are the same, due to the presence of the fluid layer 16, even if one glass plate 11 resonates, the vibration of the other glass plate 12 is not synchronized. As a result, resonance is canceled to some extent, and a higher loss coefficient can be obtained compared to the case of a single glass plate.

[0050] That is, when the resonance frequency (peak top) of the glass plate 11 is Qa, the half-value width of the resonance amplitude is wa, the resonance frequency (peak top) of the other glass plate 12 is Qb, and the half-value width of the resonance amplitude is wb, it is preferable to satisfy the following relationship of [Equation 1]. (wa + wb) / 4 < |Qa - Qb| ··· [Equation 1] The larger the value of the left side in the above [Equation 1], the larger the difference in resonance frequencies (|Qa - Qb|) between the glass plate 11 and the glass plate 12, and it is preferable because a high loss coefficient can be obtained.

[0051] Therefore, it is more preferable to satisfy the following [Equation 2], and it is more preferable to satisfy the following [Equation 3]. (wa + wb) / 2 < |Qa - Qb| ··· [Equation 2] (wa + wb) / 1 < |Qa - Qb| ··· [Equation 3] Note that the resonance frequency (peak top) and the half-value width of the resonance amplitude of the glass plate can be measured in the same manner as the loss coefficient in the glass vibrator.

[0052] The glass plate 11 and the glass plate 12 are preferably such that the mass difference is smaller, and more preferably there is no mass difference. When there is a mass difference between the glass plates, the resonance of the lighter glass plate can be suppressed by the heavier glass plate, but it is difficult to suppress the resonance of the heavier glass plate by the lighter glass plate. That is, when there is a bias in the mass ratio, the resonance vibrations cannot be canceled out by each other due to the difference in inertial forces in principle.

[0053] The mass ratio of the glass plate 11 and the glass plate 12 represented by (glass plate 11 / glass plate 12) is preferably 0.8 to 1.25 (8 / 10 to 10 / 8), more preferably 0.9 to 1.1 (9 / 10 to 10 / 9), and even more preferably 1.0 (10 / 10, mass ratio 0).

[0054] The thinner the thicknesses of the glass plates 11 and 12 are, the easier it is for the glass plates to adhere to each other through the fluid layer, and the easier it is to vibrate the glass plates with less energy. Therefore, in the case of diaphragm applications such as speakers, the thinner the thickness of the glass plates, the more preferable. Specifically, the thicknesses of the glass plates 11 and 12 are preferably 15 mm or less, more preferably 10 mm or less, still more preferably 5 mm or less, even more preferably 3 mm or less, particularly preferably 1.5 mm or less, and particularly more preferably 0.8 mm or less. On the other hand, if it is too thin, the influence of surface defects of the glass plate is likely to become prominent, cracks are likely to occur, and it becomes difficult to perform strengthening treatment. Therefore, 0.01 mm or more is preferable, and 0.05 mm or more is more preferable.

[0055] Also, in the application of building and vehicle opening members for suppressing the generation of abnormal noise caused by resonance phenomena, the thicknesses of the glass plates 11 and 12 are preferably 0.5 to 15 mm, more preferably 0.8 to 10 mm, and still more preferably 1.0 to 8 mm. In the application of glass substrates for magnetic recording media with enhanced vibration damping effect, the thicknesses of the glass plate 11 and the glass plate 12 are preferably 0.3 to 1.2 mm, more preferably 0.4 to 1.0 mm, and still more preferably 0.5 to 0.8 mm.

[0056] For at least one of the glass plates 11 and 12, the larger the loss coefficient, the greater the vibration attenuation as the glass vibrator G, which is preferable for diaphragm applications. Specifically, the loss coefficient of the glass plate at 25 °C is preferably 1×10 -4 or more, more preferably 3×10 -4 or more, and still more preferably 5×10 -4 or more. The upper limit is not particularly limited, but it is preferably 5×10 -3 or less from the viewpoints of productivity and manufacturing cost. Moreover, it is more preferable that both the glass plate 11 and the glass plate 12 have the above loss coefficient. The loss coefficient of the glass plate can be measured in the same manner as the loss coefficient in the glass vibrator G.

[0057] At least one of the glass plates 11 and 12 is preferably used as a diaphragm because the higher the longitudinal sound velocity value in the plate thickness direction, the better the sound reproducibility in the high-frequency range. Specifically, the longitudinal sound velocity value of the glass plate is preferably 5.0×10 3 m / s or more, more preferably 5.5×10 3 m / s or more, and even more preferably 6.0×10 3 m / s or more. The upper limit is not particularly limited, but from the viewpoints of the productivity of the glass plate and the raw material cost, it is preferably 7.0×10 3 m / s or less. Further, it is more preferable that both the glass plates 11 and 12 satisfy the above sound velocity value. The sound velocity value of the glass plate can be measured in the same manner as the longitudinal sound velocity value in the glass vibrator.

[0058] The compositions of the glass plates 11 and 12 are not particularly limited, but are preferably, for example, in the following ranges. SiO2: 40 to 80% by mass, Al2O3: 0 to 35% by mass, B2O3: 0 to 15% by mass, MgO: 0 to 20% by mass, CaO: 0 to 20% by mass, SrO: 0 to 20% by mass, BaO: 0 to 20% by mass, Li2O: 0 to 20% by mass, Na2O: 0 to 25% by mass, K2O: 0 to 20% by mass, TiO2: 0 to 10% by mass, and ZrO2: 0 to 10% by mass. However, the above compositions account for 95% by mass or more of the entire glass.

[0059] The compositions (compositions expressed in mol% on an oxide basis) of the glass plates 11 and 12 are more preferably in the following ranges. SiO2: 55 to 75% by mass, Al2O3: 0 to 25% by mass, B2O3: 0 to 12% by mass, MgO: 0 to 20% by mass, CaO: 0 to 20% by mass, SrO: 0 to 20% by mass, BaO: 0 to 20% by mass, Li2O: 0 to 20% by mass, Na2O: 0 to 25% by mass, K2O: 0 to 15% by mass, TiO2: 0 to 5% by mass, and ZrO2: 0 to 5% by mass. However, the above compositions account for 95% by mass or more of the entire glass.

[0060] The smaller the specific gravity of the glass plates 11 and 12, the less energy is required to vibrate the glass plates. Specifically, the specific gravity of the glass plates 11 and 12 is preferably 2.8 or less, more preferably 2.6 or less, and even more preferably 2.5 or less. The lower limit is not particularly limited, but it is preferably 2.2 or more. The specific elastic modulus, which is the value obtained by dividing the Young's modulus of the glass plates 11 and 12 by the density, increases the rigidity of the glass plates as it increases. Specifically, the specific elastic modulus of the glass plates 11 and 12 is preferably 7 m 2 / s 2 or more, more preferably 7 m 2 / s 2 or more, and even more preferably 7 m 2 / s 2 or more. The upper limit is not particularly limited, but it is preferably 7 m 2 / s 2 or less.

[0061] The glass plates constituting the glass vibrator G may be two or more. However, as shown in FIG. 6, three or more glass plates may be used. In the case of two glass plates, the glass plate 11 and the glass plate 12 are used. In the case of three or more glass plates, for example, the glass plate 11, the glass plate 12, and the glass plate 13 may all be glass plates of different compositions, may all be glass plates of the same composition, or may be used in combination with glass plates of the same composition and glass plates of different compositions. Among them, it is preferably used from the viewpoint of vibration damping property to use two or more types of glass plates having different compositions. Similarly, regarding the mass and thickness of the glass plates, they may all be different, all the same, or some may be different. Among them, it is preferably used from the viewpoint of vibration damping property that the masses of the constituent glass plates are all the same.

[0062] At least one of the glass plates constituting the glass resonator G may be a physically strengthened glass plate or a chemically strengthened glass plate. This is useful for preventing the destruction of the glass resonator G composed of the glass plate structure. When it is desired to increase the strength of the glass resonator G, it is preferable that the glass plate located on the outermost surface of the glass resonator G is a physically strengthened glass plate or a chemically strengthened glass plate, and it is more preferable that all of the constituent glass plates are physically strengthened glass plates or strengthened glass plates.

[0063] Also, using devitrified glass or phase-separated glass as the glass plate is also useful in terms of increasing the longitudinal wave velocity value and strength. In particular, when it is desired to increase the strength of the glass resonator G composed of the glass plate structure, it is preferable that the glass plate located on the outermost surface of the glass resonator G is devitrified glass or phase-separated glass.

[0064] The glass resonator G may form a coating layer 21 shown in FIG. 7(A) or a film 23 shown in FIG. 7(B) on at least one outermost surface of the glass plate structure within a range that does not impair the effects of the present invention. The application of the coating layer 21 or the attachment of the film 23 is suitable, for example, for preventing damage. The thickness of the coating layer 21 and the film 23 is preferably 1 / 5 or less of the thickness of the surface glass plate. Conventionally known ones can be used for the coating layer 21 and the film 23. As the coating layer 21, for example, a water-repellent coating, a hydrophilic coating, a water-slipping coating, an oil-repellent coating, an anti-reflection coating, a heat-insulating coating, etc. can be used. Also, as the film 23, for example, a glass splash-preventing film, a color film, a UV-cut film, an IR-cut film, a heat-insulating film, an electromagnetic wave shielding film, etc. can be used.

[0065] (Sealing material) As shown in FIG. 8, at least a part of the outer peripheral end face of the glass resonator G may be sealed with a sealing material 25 that does not interfere with the vibration of the glass resonator G. As the sealing material 25, highly elastic rubber, resin, gel, etc. can be used.

[0066] Regarding the resin used as the sealing material 25, acrylic, cyanoacrylate, epoxy, silicone, urethane, phenolic, etc. can be used. As the curing method, one-component type, two-component mixing type, heat curing, ultraviolet curing, visible light curing, etc. can be mentioned. A thermoplastic resin (hot melt bond) can also be used. Examples include ethylene vinyl acetate type, polyolefin type, polyamide type, synthetic rubber type, acrylic type, and polyurethane type. Regarding rubber, for example, natural rubber, synthetic natural rubber, butadiene rubber, styrene-butadiene rubber, butyl rubber, nitrile rubber, ethylene-propylene rubber, chloroprene rubber, acrylic rubber, chlorosulfonated polyethylene rubber (Hypalon), urethane rubber, silicone rubber, fluororubber, ethylene-vinyl acetate rubber, epichlorohydrin rubber, polysulfide rubber (Thiokol), and hydrogenated nitrile rubber can be used. If the thickness t of the sealing material 25 is too thin, sufficient strength cannot be ensured, and if it is too thick, it will hinder vibration. Therefore, the thickness of the sealing material 25 is preferably 10 μm or more and 5 times or less the total thickness of the glass components, and more preferably 50 μm or more and thinner than the total thickness of the glass components.

[0067] As shown in FIGS. 9(A) and 9(B), in the glass resonator G, a stepped portion 27 having a stepped shape in a cross-sectional view is formed by arranging the end faces of the glass plate 11 and the glass plate 12 to be displaced from each other. And in this stepped portion 27, the sealing material 25 is provided so as to seal at least the fluid layer 16.

[0068] The sealing material 25 is in close contact with the end face 11a of the glass plate 11, the end face 16a of the fluid layer 16, and the main surface 12a of the glass plate 12 at the stepped portion 27. With such a configuration, the fluid layer 16 is sealed by the sealing material 25, leakage of the fluid layer 16 is prevented, the bonding of the glass plate 11, the fluid layer 16, and the glass plate 12 is strengthened, and the strength of the glass resonator G is increased.

[0069] Further, in the stepped portion 27, the end face 11a of the glass plate 11 and the end face 16a of the fluid layer 16 are configured to be perpendicular to the main face 12a of the glass plate 12. As a result, the sealing material 25 has a contour extending in an L shape along the stepped portion 27 in a cross-sectional view. With such a configuration, the joining of the glass plate 11, the fluid layer 16, and the glass plate 12 is further strengthened, and the strength of the glass resonator G is further increased.

[0070] Furthermore, the sealing material 25 has a tapered surface 25a. Although the edge portion of the glass resonator G may be tapered or the like, by adopting such a shape of the sealing material 25, the same effect as when the glass resonator G is processed can be obtained.

[0071] Moreover, in this glass resonator G, the end faces of the glass plate 11 and the glass plate 12 are displaced from each other, and the sealing material 25 is provided at the stepped portion 27. Therefore, in this glass resonator G, when viewed from the glass plate 12 side, the sealing material 25 is disposed on the back side of the glass plate 12, so that the sealing material 25 is not visible when viewed from the glass plate 12 side. Thereby, the design property of the glass resonator G can be enhanced.

[0072] The glass resonator G may be planar, or may be a curved surface shape that curves (bends) according to the installation location, for example, as shown in FIG. 10. Also, although not shown, it may be a shape that includes both a planar portion and a curved surface portion. That is, the glass resonator G may be a three-dimensional shape having a curved portion that is bent in a concave or convex shape at least in part. In this way, by making it a three-dimensional shape according to the installation location, the appearance at the installation location can be improved, and the design property can be enhanced.

[0073] Furthermore, in the glass resonator G in which the stepped portion 27 on the outer edge is sealed with the sealing material 25, as shown in FIG. 11(A), it may be formed in a curved surface shape (three-dimensional shape) such that the glass plate 12 side is recessed. In this case, the outer edge of the glass plate 12 extends outside the glass plate 11. Also, as shown in FIG. 11(B), it may be formed in a curved surface shape obtained by inverting (A). Also in this case, the outer edge of the glass plate 12 extends outside the glass plate 11.

[0074] Also in the case of these glass resonators G, when viewed from the glass plate 12 side, since the sealing material 25 is disposed on the back side of the glass plate 12, the sealing material 25 can be made invisible and hidden from the glass plate 12 side. Thereby, the appearance at the installation location can be improved, and the design property of the glass resonator G itself can be further enhanced.

[0075] <Application Examples of the Vibration Device> Taking advantage of the fact that the vibration device 100 described above can have a wide main surface area, for example, when the glass resonator G has translucency, a display screen can be arranged on the back side in the viewing direction (Va direction in FIG. 1(A)) and used as a display. Also, a light-emitting element can be provided on the surface of the glass resonator G to provide a display function. Furthermore, a screen film can be attached to the glass resonator G to add a function of projecting and displaying an image. It can also be used as a window glass.

[0076] Hereinafter, application examples of the vibration device 100 having this configuration will be described in more detail. The vibration device 100 is, for example, as a member for an electronic device, a full-range speaker, a bass reproduction speaker in the 15 Hz to 200 Hz band, a high-frequency reproduction speaker in the 10 kHz to 100 kHz band, and the area of the diaphragm is 0.2 m 2 The above large speakers, the area of the diaphragm is 3 cm 2It can be used in the following small speakers, flat speakers, cylindrical speakers, transparent speakers, cover glasses for mobile devices that function as speakers, cover glasses for TV displays, displays where video signals and audio signals are generated from the same surface, speakers for wearable displays, electro-optical displays, lighting fixtures, etc. It can also be used as a diaphragm for microphones and as a vibration sensor.

[0077] And the vibration device 100 can be used as an interior vibration member for transportation machinery such as vehicles and as an in-vehicle / on-board speaker. For example, it can be used in side mirrors, sun visors, instrument panels, dashboards, ceilings, doors, and other various interior panels that function as speakers. Furthermore, these can also be made to function as microphones or diaphragms for active noise control.

[0078] Also, the vibration device 100 can be used, for example, as an opening member used in buildings, transportation machinery, etc. In that case, functions such as IR cut, UV cut, and coloring can also be imparted to the diaphragm.

[0079] When applying the vibration device 100 to a part of the opening member, it can be configured to mount the exciter E on one or both main surfaces of the glass vibrator G. According to this configuration, it becomes possible to easily reproduce sounds in the high-frequency range that were difficult to reproduce until now. Also, since the degree of freedom in the size, shape, color tone, etc. of the glass vibrator G is high and it is possible to apply a design, an opening member with excellent design can be obtained.

[0080] Also, by sampling sound or vibration with a microphone for sound collection or a vibration detector installed on the surface or in the vicinity of the glass vibrator G and generating vibrations in the same phase or opposite phase to this on the diaphragm, the sampled sound or vibration can be amplified or canceled out.

[0081] More specifically, the vibration device 100 can be applied to in-vehicle speakers, out-vehicle speakers, vehicle front glass, side glass, rear glass, or roof glass having a sound insulation function. Further, it can also be used as a vehicle window, a structural member, or a decorative panel whose water repellency, snow adhesion resistance, ice adhesion resistance, and antifouling property are improved by sound wave vibration. Specifically, it can be used as automotive window glass or mirrors, as well as lenses, sensors, and their cover glasses.

[0082] As building opening members, it can be used as window glass, door glass, roof glass, interior materials, exterior materials, decorative materials, structural materials, outer walls, and cover glasses for solar cells that function as diaphragms and vibration detection devices. They may function as acoustic reflection (reverberation) plates. Further, the above-mentioned water repellency, snow adhesion resistance, and antifouling property can also be improved by sound wave vibration.

[0083] (Application example of the vibration device to the speaker unit) FIG. 12 is a perspective view of a speaker unit incorporating a vibration device in a housing. FIG. 13 is a cross-sectional view taken along line XIII-XIII shown in FIG. 12. As shown in FIGS. 12 and 13, the vibration device 100 can be used as a speaker unit 200. The speaker unit 200 includes a housing 31 formed in a concave shape for holding a glass vibrator G.

[0084] The housing 31 has a bottom plate portion 33 and a peripheral wall portion 35 provided to project from the periphery of the bottom plate portion 33. The vibration device 100 is inserted into the inner space 37 of the housing 31 surrounded by the bottom plate portion 33 and the peripheral wall portion 35 from the side of the exciter E. Thereby, the housing 31 covers the outer peripheral edge of the glass vibrator G in a state where the exciter E is accommodated in the inner space 37.

[0085] The exciter E is preferably fixed to the glass resonator G on one side and to the housing 31 on the other side. As shown in FIG. 13, a support member 39 such as a metal or resin material may be provided between the exciter E and the housing 31. In this way, since the exciter E is in contact with the housing 31, the sound pressure generated on the back side of the glass resonator G can be reduced in the inner space 37 of the housing 31. Note that the other side of the exciter E does not necessarily have to be fixed to the housing 31.

[0086] By housing the vibration device 100 in the housing 31, the outer peripheral edge of the glass resonator G is arranged with a gap C from the inner peripheral surface of the peripheral wall portion 35, and the surface of the glass resonator G is arranged substantially flush with the end surface 35a of the edge portion of the peripheral wall portion 35. That is, the glass resonator G is supported by the housing 31 via the exciter E and is in a non-contact state with the housing 31. Thereby, it is possible to prevent the vibration of the glass resonator G from being attenuated due to interference with the housing 31.

[0087] Air holes 36 that communicate the inner space 37 of the housing 31 with the outside of the housing may be formed in the peripheral wall portion 35 of the housing 31. The air holes 36 reduce the differential pressure between the inner space 37 of the housing 31 and the outside of the housing during the vibration of the glass resonator G and function as a silencer for the sound generated from the back of the glass resonator G. Further, since the speaker unit 200 has a structure in which the back side of the glass resonator G is covered with the housing 31, it is possible to prevent the sound generated from the back of the glass resonator G from returning to the front side of the glass resonator G. Further, by attaching a sound-absorbing material such as felt or sponge to the inside or outside of the housing 31, the sound-absorbing effect of the housing 31 can be enhanced, and the sound leakage from the back side of the glass resonator G can be reduced.

[0088] The speaker unit 200 having the above configuration can be mounted on the door 41 of a vehicle and used as an in-vehicle speaker. As shown in FIG. 14, the door 41 of the vehicle has a metal door panel 43 that is a structural member and an interior material 51 that is attached to the inside of the vehicle of the door panel 43.

[0089] On the vehicle interior side of the interior material 51, an elbow rest 55 is provided, and an opening 53 is formed at the upper part of the elbow rest 55. Further, on the door panel 43, a mounting hole 45 is formed in a part of its vehicle interior side.

[0090] The speaker unit 200 is an assembly in which the glass vibrator G, the exciter E, and the housing 31 are integrated, and is fitted into the mounting hole 45 of the door panel 43. Then, in the opening 53 of the interior material 51, the glass vibrator G is arranged along the surface of the interior material 51.

[0091] In this way, when using the speaker unit 200 provided with the vibration device 100 as an in-vehicle speaker, it is only necessary to incorporate the assembly in which the vibration device 100 and the housing 31 are integrated into the door panel 43, and the vibration device 100 can be assembled to the door 41 with a simple operation.

[0092] The above-described arrangement mode of the speaker unit 200 is the case where the speaker unit 200 is provided in the concave portion Fd recessed toward the vehicle exterior in the interior material 51 of the door 41 shown in FIG. 15, but the speaker unit 200 may be arranged in the convex portion Fp protruding toward the vehicle interior side. Also, the speaker unit 200 may be arranged in both the concave portion Fd and the convex portion Fp. In that case, it can be made highly functional by varying specifications such as changing the range of the output frequency for each speaker unit.

[0093] When mounting the speaker unit 200 on the door 41, by making the glass vibrator G of the vibration device 100 into a concave or convex three-dimensional shape according to the surrounding shape of the mounting position, an appearance excellent in design matching the surface shape of the concave portion Fd or the convex portion Fp of the interior material 51 can be achieved. Also, since the glass vibrator G has a high degree of freedom in its size, shape, color tone, etc., and it is easy to apply design properties, an in-vehicle speaker excellent in design can be constructed.

[0094] As shown in FIG. 16, when mounting the speaker unit 200 equipped with the vibration device 100 on the door 41, the gap between the opening 53 of the interior material 51 and the speaker unit 200 may be blocked with the film 61. Thereby, intrusion of foreign matters, dust, etc. from the inside of the vehicle into the speaker unit 200 through the gap between the opening 53 and the speaker unit 200 can be prevented, and leakage of the sound generated from the back side of the glass vibrator G into the vehicle can be suppressed.

[0095] The housing 31 of the above-described speaker unit 200 can be further configured in other modes. For example, instead of the housing 31, the vibration device 100 may be housed in a recess formed in the door panel 43 shown in FIG. 14. In that case, it is preferable to arrange a sound-absorbing material such as felt or sponge on the door panel 43 facing the vibration device 100. According to this, there is no need to separately prepare the above-described housing, the manufacturing process can be simplified, and the component cost can be reduced.

[0096] Also, a part of the glass vibrator G to which the exciter E is attached may be supported on a fixed side such as the door panel 43 via an elastic body such as a rubber material or a spring material. In that case as well, the above-described housing becomes unnecessary and the configuration can be simplified.

[0097] Furthermore, when mounting the vibration device 100 on the door 41, the exciter E may be attached to the surface on the indoor side of the peripheral edge of the glass vibrator G, and this exciter E may be arranged so as to overlap the peripheral edge of the opening 53 of the interior material 51 so as not to be visible from the inside of the vehicle. In that case, since the exciter E attached to the peripheral portion of the glass vibrator G is hidden by the interior material 51, the aesthetic appearance is not impaired.

[0098] Thus, the present invention is not limited to the above-described embodiments, and it is also contemplated by the present invention that those skilled in the art can make changes and applications based on combining each configuration of the embodiments, the description of the specification, and well-known techniques, and are included in the scope for which protection is sought.

[0099] Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention. This application is based on a Japanese patent application filed on December 27, 2018 (Japanese Patent Application No. 2018-246215), the content of which is incorporated herein by reference.

Industrial Applicability

[0100] The vibration device according to the present invention can stably excite a plurality of elongated plate-shaped glass vibrators G having significantly different vertical and horizontal dimensional ratios while maintaining sufficient acoustic performance by a plurality of exciters E. Therefore, it is suitably used as a member for electronic devices, a vibration member for the interior of transportation machines such as vehicles, an in-vehicle / on-board speaker, and an opening member used in buildings, transportation machines, etc.

Explanation of Reference Numerals

[0101] 11, 12 Glass plates 16 Fluid layer 31 Housing 36 Air holes 100, 110, 120 Vibration devices E Exciter G Glass vibrator R Reinforcing member

Claims

1. A vibration device comprising a plate-shaped glass resonator and a plurality of exciters attached to the glass resonator and generating vibrations in response to an input electrical signal, wherein a reinforcing member is provided on the glass resonator, the reinforcing member is formed integrally with the glass resonator by providing a thick portion on a part of the glass resonator, and is fixed to the exciter, the aspect ratio La / Lb of the length La of the long side and the length Lb of the short side of the quadrangle inscribed by the outer edge of the glass resonator is 1.2 or more and 50 or less, Let the number of the exciters be n, and the minimum value of the distance between the exciters be S ｍｉｎ , the number n of the exciters and the minimum value S of the distance between the exciters ｍｉｎ When the relational value with is α (α = S ｍｉｎ / (n - 1) / La), then where α is 0.2 or more and 0.8 or less, When the number n of the exciters is 3 or more, a value β (β = Sσ / S) obtained by dividing the standard deviation Sσ of the distances between the exciters by the average value S ａｖｅ is a vibration device that is 0 or more and 0.5 or less. ａｖｅ ​

2. The loss factor of the glass resonator at 25 °C is 1×10 －２ or more, and the longitudinal wave velocity value in the plate thickness direction of the glass resonator is 5.0×10 ３ m / s or more. The vibration device according to claim 1.

3. The vibration device according to claim 1 or claim 2, wherein the glass resonator includes two or more glass plates, and includes a fluid layer containing a liquid between at least a pair of the glass plates.

4. The vibration device according to any one of claims 1 to 3, further comprising a housing covering at least one surface of the glass resonator, wherein the exciter is housed in the inner space of the housing.

5. The vibration device according to claim 4, wherein one side of the exciter is fixed to the glass resonator and the other side is fixed to the housing.

6. The vibration device according to claim 4 or 5, wherein the housing is formed with air holes communicating the inner space of the housing and the outside of the housing.

7. The vibration device according to any one of claims 4 to 6, wherein a sound absorbing material is provided in the inner space of the housing.

8. The vibration device according to any one of claims 1 to 7, wherein the sound pressure fluctuation value at a frequency of 200 Hz to 10 kHz is 20 dB or less.

9. The vibration device according to any one of claims 1 to 8, wherein the glass resonator has a concave or convex curved surface at least in part.

10. The reinforcing member is provided along the longitudinal direction of the glass resonator, The vibration device according to any one of claims 1 to 9.

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