Vibration device and imaging device

Abstract

A vibration device 1 of the present invention comprises: a translucent body 10; a vibration body 20 which is a cylindrical member having one end 20a, the other end 20b, and a side wall 20c connecting the one end 20a and the other end 20b, ais coupled to the translucent body 10 at the one end 20a, and vibrates the translucent body 10; an extending part 21 that outwardly extends from the side wall 20c of the vibration body 20; and a piezo element 30 that is arranged at the other end 20b of the vibration body 20.

Description

[Technical Field]

[0001] The present invention relates to a vibration device and an imaging device. [Background technology]

[0002] A droplet removal device is known that removes droplets and the like that have adhered to a light beam passing area of ​​a drip-proof cover.

[0003] For example, Patent Document 1 discloses a droplet removal device that is equipped with a vibrating member that is connected to the end of the curved surface that forms the dome portion of an optical element and generates bending vibrations in the dome portion. The droplet removal device described in Patent Document 1 controls the vibrating member to generate predetermined vibrations in the dome portion, thereby miniaturizing and removing attached droplets, etc. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-170303 Summary of the Invention [Problem to be solved by the invention]

[0005] The droplet eliminating device described in Patent Document 1 still has room for improvement in terms of vibrating the dome portion efficiently.

[0006] Therefore, the present invention provides a vibration device that can efficiently vibrate a transparent body. [Means for solving the problem]

[0007] A vibration device according to one aspect of the present invention comprises: A transparent body; a vibrating body that is a cylindrical member having one end, the other end, and a side wall connecting the one end and the other end, the vibrating body being connected to the light-transmitting body at the one end and vibrating the light-transmitting body; an extension portion extending outward from the side wall of the vibrating body; a piezoelectric element disposed at the other end of the vibrating body; Equipped with. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a vibration device that can efficiently vibrate a transparent body. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view showing a vibration device according to a first embodiment; [Figure 2] FIG. 2 is a cross-sectional view showing an imaging device including the vibration device of FIG. 1; [Figure 3] FIG. 10 is a diagram showing a simulation result of the displacement distribution in the vibration device according to the first embodiment. [Figure 4A] Graph showing width dependency of displacement of stretched section [Figure 4B] Graph showing thickness dependency of displacement of stretched section [Figure 5] FIG. 10 is a partial cross-sectional view showing a vibration device according to a first modification of the first embodiment; [Figure 6] FIG. 10 is a partial cross-sectional view showing a vibration device according to a second modification of the first embodiment; [Figure 7] FIG. 10 is a partial cross-sectional view showing a vibration device according to a third modification of the first embodiment; [Figure 8] FIG. 10 is a partial cross-sectional view showing a vibration device according to a second embodiment. [Figure 9A] 9 shows the results of a simulation of the displacement distribution in the vibration device of FIG. 8. [Figure 9B] Figure showing the results of a resonance analysis of the vibrating body of a vibrating device [Figure 9C] Figure showing the results of a resonance analysis of the vibrating body of a vibrating device [Figure 10A] Graph showing the width dependency of weight displacement [Figure 10B] Graph showing the thickness dependency of the weight displacement [Figure 11] FIG. 10 is a partial cross-sectional view showing a vibration device according to a first modification of the second embodiment; [Figure 12]FIG. 10 is a partial cross-sectional view showing a vibration device according to a second modification of the second embodiment; [Figure 13] FIG. 10 is a perspective view showing a vibration device according to a third embodiment. [Figure 14] Exploded view of the vibration device in Figure 13 [Figure 15] AA cross section of the vibration device in FIG. [Figure 16] An enlarged view of a portion of the vibration device in Figure 15. [Figure 17] FIG. 11 is a diagram showing a simulation result of the displacement distribution in the vibration device according to the third embodiment. [Figure 18] FIG. 13 is a partial cross-sectional view showing a vibration device according to a first modification of the third embodiment. [Figure 19] FIG. 10 is a partial cross-sectional view showing a vibration device according to a second modification of the third embodiment. [Figure 20] FIG. 10 is a partial cross-sectional view showing a vibration device according to a third modification of the third embodiment. [Figure 21] FIG. 10 is a partial cross-sectional view showing a vibration device according to a fourth modification of the third embodiment. [Figure 22] 10 is a cross-sectional view showing a vibration device according to a fourth embodiment. [Figure 23] FIG. 13 is a partial cross-sectional view showing a vibration device according to a first modification of the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] (Background to the invention) Cameras used outdoors, such as in-vehicle cameras, surveillance cameras, or cameras mounted on drones, are exposed to wind and rain and therefore have covers made of glass, transparent plastic, etc. If water droplets or other foreign matter adhere to the cover, the foreign matter may appear in the image captured by the camera, obstructing the camera's view and preventing a clear image from being obtained.

[0011] Therefore, devices such as the droplet removal device described in Patent Document 1 are being considered that place a piezoelectric element on the drip-proof cover, causing the drip-proof cover to vibrate in a bending manner, thereby miniaturizing and atomizing foreign matter such as water droplets adhering to the drip-proof cover and removing them.

[0012] In the droplet removal device described in Patent Document 1, the piezoelectric element is adhesively fixed to the flange of the drip-proof cover. Therefore, vibration of the piezoelectric element also vibrates the flange of the drip-proof cover, which is outside the field of view of the imaging device. In other words, there is a problem in that the vibration of the piezoelectric element escapes to the flange of the drip-proof cover, making it difficult to vibrate the drip-proof cover efficiently.

[0013] Furthermore, due to manufacturing variations in the droplet removal device, the vibration of the piezoelectric element cannot be efficiently transmitted to the drip-proof cover, making it difficult to efficiently vibrate the drip-proof cover.

[0014] The present inventor(s) have studied a vibration device that can efficiently vibrate a transparent body, and have arrived at the following invention.

[0015] The vibration device according to the first aspect of the present invention comprises: A transparent body; a vibrating body that is a cylindrical member having one end, the other end, and a side wall connecting the one end and the other end, the vibrating body being connected to the light-transmitting body at the one end and vibrating the light-transmitting body; an extension portion extending outward from the side wall of the vibrating body; a piezoelectric element disposed at the other end of the vibrating body; Equipped with.

[0016] With this configuration, it is possible to provide a vibration device that can efficiently vibrate the light-transmitting body.

[0017] In the vibration device according to the second aspect of the present invention, The extension portion may be bent toward the one end or the other end.

[0018] With this configuration, a guide for letting water droplets and the like flow out can be formed, and water droplets and the like can be efficiently removed.

[0019] In the vibration device according to the third aspect of the present invention, The extension portion may extend outward from the one end of the vibrating body.

[0020] With this configuration, the extensions become vibration nodes, further improving vibration efficiency.

[0021] In the vibration device according to the fourth aspect of the present invention, The extension may extend outward from the one end of the vibrating body.

[0022] With this configuration, the extensions become vibration nodes, so that adhesion of foreign matter such as water droplets does not affect vibration performance.

[0023] A vibration device according to a fifth aspect of the present invention comprises: moreover, a retainer including: a cylindrical first member disposed on the one end side of the vibrating body and attached to the side wall of the vibrating body; and a second member extending inward from an inner surface of the first member and contacting a surface of the light-transmitting body opposite to a surface connected to the vibrating body; Equipped with The extension may be provided to extend outward from an outer surface of the first member of the retainer.

[0024] With this configuration, the light-transmitting body can be firmly held, and the reliability of the vibration device can be improved.

[0025] In the vibration device according to the sixth aspect of the present invention, One or more weights may be disposed on at least one of a first surface on the one end side and a second surface on the other end side of the extension portion.

[0026] With this configuration, the weight portion as well as the extension portion becomes a vibration node, thereby further improving vibration efficiency.

[0027] In the vibration device according to the seventh aspect of the present invention, The weights may be arranged at equal intervals on the extension portion when viewed in the axial direction of the vibrating body.

[0028] With this configuration, the vibration efficiency of the vibration device can be further improved.

[0029] A vibration device according to an eighth aspect of the present invention comprises: Further, a cover is provided, in which a hole exposing the light-transmitting body is formed, the cover is disposed outside the light-transmitting body, is attached to the extension portion, and is in contact with a surface of the one weight; The one weight is formed in a ring shape, The one weight may have a seal member disposed in a groove provided on the surface.

[0030] This configuration prevents foreign matter such as water droplets from entering the inside of the vibration device while maintaining the vibration performance of the vibration device, thereby improving the reliability of the vibration device, specifically its waterproof performance.

[0031] In the vibration device according to the ninth aspect of the present invention, The end of the cover on the hole side may be tapered so that the thickness decreases toward the light-transmitting body.

[0032] With this configuration, it is possible to improve both the performance and reliability of the vibration device.

[0033] In a vibration device according to a tenth aspect of the present invention, the vibrator has a first protruding portion that protrudes inward from the one end and a second protruding portion that protrudes inward from the other end, The vibration device may further include a holder connected to the second protrusion and configured to hold the vibrating body.

[0034] With this configuration, the second protrusion of the vibrating body becomes a node, so the holder can be connected to the vibration device without affecting vibration performance. Also, the effective volume of the vibration device can be reduced, resulting in a compact vibration device.

[0035] An imaging device according to an eleventh aspect of the present invention comprises: Any of the vibration devices described above; an imaging element disposed inside the vibration device; Equipped with.

[0036] With this configuration, it is possible to provide a highly reliable imaging device.

[0037] An embodiment of the present invention will be described below with reference to the accompanying drawings. Note that the following description is merely illustrative in nature and is not intended to limit the present invention, its applications, or its uses. Furthermore, the drawings are schematic, and the ratios of the dimensions do not necessarily correspond to the actual ones.

[0038] (Embodiment 1) [Overall configuration] FIG. 1 is a cross-sectional view showing a vibration device 1 according to a first embodiment.

[0039] 1, the vibration device 1 includes a light-transmitting body 10, a vibration body 20, an extension portion 21, and a piezoelectric element 30. The vibration device 1 can be used as an imaging device by accommodating an imaging element therein.

[0040] The vibration device 1 is a device that transmits vibrations caused by a piezoelectric element 30 arranged on a vibrating body 20 to a light-transmitting body 10 via the vibrating body 20 to vibrate the light-transmitting body 10 and removes foreign matter such as water droplets or mud adhering to the light-transmitting body 10. The vibration device 1 may be provided with a conductor (not shown) that applies an electric potential to the piezoelectric element 30.

[0041] FIG. 2 is a cross-sectional view showing an imaging device 100 including the vibration device 1 of FIG. 1. As shown in FIG. 2, the vibration device 1 can be used as the imaging device 100 by accommodating an imaging element 60 inside. In other words, the imaging device 100 includes the vibration device 1 and the imaging element 60. The imaging element 60 is connected to, for example, a substrate 61. The imaging element 60 can capture an image of an object to be imaged outside the vibration device 1 through the light-transmitting body 10 of the vibration device 1. In FIG. 2, the vibration device 1 is fixed to the substrate 61 via a holding portion 50.

[0042] Each of the components that make up the vibration device 1 will be described in detail below.

[0043] <Translucent body> The light-transmitting body 10 functions as a cover for protecting the imaging element housed in the vibration device 1 from adhesion of foreign matter. The light-transmitting body 10 may also function as an optically designed lens. The light-transmitting body 10 has a translucency that allows energy rays or light of a wavelength detected by the imaging element to pass through. In this embodiment, as shown in FIG. 1, the light-transmitting body 10 is formed in a dome shape.

[0044] Examples of materials that can be used for the light-transmitting body 10 include glass such as soda glass, borosilicate glass, aluminosilicate glass, and quartz glass, light-transmitting plastic, light-transmitting ceramic, and synthetic resin. The strength of the light-transmitting body 10 can be increased by forming the light-transmitting body 10 from tempered glass whose strength has been improved by, for example, chemical strengthening.

[0045] <Vibration body> The vibrating body 20 vibrates the light-transmitting body 10 upon receiving vibrations from the piezoelectric element 30. As shown in FIG. 1 , the vibrating body 20 is a cylindrical member having one end 20a, the other end 20b, and a side wall 20c connecting the one end 20a and the other end 20b. One end of the vibrating body 20 is connected to the light-transmitting body 10. The light-transmitting body 10 and the vibrating body 20 can be connected by, for example, an adhesive or the like.

[0046] 1, in this embodiment, a recess 20d for placing the light-transmitting body 10 is formed at one end 20a of the vibrating body 20. Alternatively, the one end 20a of the vibrating body 20 may be formed flat, and the light-transmitting body 10 may be fixed to the one end 20a with an adhesive or the like.

[0047] In this embodiment, vibrating body 20 has first protruding portion 24 protruding inward from one end 20a and second protruding portion 25 protruding inward from the other end 20b. Because vibrating body 20 has such a shape, extension portion 21 and a part of second protruding portion 25 become nodes where the amount of displacement of vibrating body 20 due to vibration is small.

[0048] The vibrating body 20 can be made of, for example, metal or ceramic. Examples of metals that can be used include stainless steel, 42 alloy, 50 alloy, invar, super invar, kovar, aluminum, and duralumin. Alternatively, the vibrating body 20 may be made of ceramics such as alumina or zirconia. The vibrating body 20 may be made of a semiconductor such as Si. The vibrating body 20 may also be subjected to an insulating coating such as anodized aluminum.

[0049] <Extension part> As shown in FIG. 1 , the extension 21 extends outward from the side wall 20c of the vibrating body 20. In the vibration device 1, the extension 21 is formed to extend outward from one end 20a of the vibrating body 20. The extension 21 is a portion that serves as a node where the amount of displacement due to vibration is zero when the vibrating body 20 is vibrating. By having the extension 21 serve as a vibration node, the vibration of the vibrating body 20 can be efficiently transmitted to the translucent body 10 without escaping to the extension 21. Furthermore, even if foreign matter such as water droplets or mud adheres to the extension 21, the impact on the vibration performance of the vibrating body 20 can be reduced.

[0050] In this embodiment, the extension 21 is a flange formed on the side wall of the vibrating body 20 on the one end 20a side. Therefore, the extension 21 has a ring-like shape when viewed from the axial direction (Z direction) of the vibrating body 20. The extension 21 and the vibrating body 20 are formed integrally. The extension 21 is formed in a plate shape having a first surface 21a on the one end 20a side of the vibrating body 20 and a second surface 21b on the other end 20b side of the vibrating body 20.

[0051] The thickness t1 of the extension 21 is preferably, for example, 0.25 mm or more and 1 mm or less. More preferably, the thickness t1 of the extension 21 is 0.5 mm. In this case, the amount of displacement of the extension 21 can be reduced, allowing the vibration of the vibrating body 20 to be efficiently transmitted to the translucent body 10. The width w1 of the extension 21 is preferably, for example, 4 mm or more and 6 mm or less. More preferably, the width w1 of the extension 21 is 4.6 mm. In this case, the amount of displacement of the extension 21 can be reduced, allowing the vibration of the vibrating body 20 to be efficiently transmitted to the translucent body 10. The width w1 of the extension 21 indicates the length of the extension 21 protruding from the side wall 20c of the vibrating body 20.

[0052] In this embodiment, the extension 21 is provided in a direction perpendicular to the axial direction (Z direction) of the vibrating body 20 from one end 20a of the vibrating body 20. That is, in the axial direction of the vibrating body 20, the extension 21 is provided so that the one end 20a of the vibrating body 20 and the first surface 21a of the extension 21 are at approximately the same height. Part 2 1 is formed.

[0053] By forming the extension 21 and one end 20a of the vibrating body 20 at approximately the same height, the amount of displacement caused by vibration of the extension 21 can be reduced, and the vibration performance of the vibrating device 1 can be improved.

[0054] <Piezoelectric element> The piezoelectric element 30 is disposed at the other end 20b of the vibrating body 20. In this embodiment, the piezoelectric element 30 is formed in a ring shape when viewed from the axial direction (Z direction) of the vibrating body 20. The piezoelectric element 30 can be fixed to the other end 20b of the vibrating body 20 by, for example, an adhesive. The shape of the piezoelectric element 30 is not limited to a ring shape, and may be any shape that can vibrate the vibrating body 20.

[0055] The piezoelectric element 30 has a piezoelectric body and electrodes. Examples of materials for forming the piezoelectric body include barium titanate (BaTiO), lead zirconate titanate (PZT: PbTiO.PbZrO), lead titanate (PbTiO), lead metaniobate (PbNbO), and bismuth titanate (BiTiO). 12 Suitable piezoelectric ceramics such as (K,Na)NbO3, or suitable piezoelectric single crystals such as LiTaO3, LiNbO3, etc. can be used.

[0056] The electrode may be, for example, a Ni electrode. The electrode may be an electrode made of a thin metal film such as Ag or Au formed by a sputtering method. Alternatively, the electrode may be formed by plating or vapor deposition in addition to the sputtering method.

[0057] The piezoelectric element 30 is controlled by, for example, a control unit. The control unit has, for example, an excitation circuit for applying a drive signal that generates vibration. The excitation circuit is connected to the piezoelectric element 30 via, for example, a power supply conductor. The piezoelectric element 30 vibrates the vibrating body 20 in the thickness direction (Z direction) of the vibration device 1 based on the drive signal from the excitation circuit. When the piezoelectric element 30 vibrates, the vibrating body 20 vibrates in the thickness direction (Z direction). In the vibration device 1, when the vibrating body 20 is vibrated, the translucent body 10 vibrates, and foreign matter such as water droplets adhering to the translucent body 10 is removed.

[0058] FIG. 3 is a diagram showing the results of a simulation of the displacement distribution in the vibration device 1 of the first embodiment. The simulation was performed by piezoelectric analysis (resonance analysis) using Femtet manufactured by Murata Software Co., Ltd. The calculation conditions for the simulation of FIG. 3 are as follows: The material of the translucent body 10 is equivalent to soda glass with a density of 2.48 g / cm3 and a Young's modulus of 73 GPa. The diameter of the translucent body 10 is 14 mm. The material of the vibration body 20 is equivalent to SUS420J2 with a density of 7.75 g / cm3 and a Young's modulus of 200 GPa. The density of the piezoelectric element 30 is 7.83 g / cm3, and a voltage of 60 Vp-p is applied to the top and bottom surfaces of the piezoelectric element 30 (the surface in contact with the vibration body 20 and the surface opposite thereto). The piezoelectric element has an external diameter 16 mm, inner diameter 10 mm, and thickness 1 mm. 3 In the graph, the lighter the color, the greater the displacement.

[0059] As shown in FIG. 3, the extension 21 has a displacement close to 0 and barely vibrates. This indicates that the extension 21 is a vibration node. On the other hand, the displacement is greatest near the center of the translucent body 10. This shows that the vibration of the vibrating body 20 is transmitted to the translucent body 10 without escaping to the extension 21. This makes it possible to efficiently remove foreign matter such as water droplets or mud adhering to the translucent body 10.

[0060] FIG. 4A is a graph showing the width dependency of the displacement of the stretched portion 21. FIG. 4B is a graph showing the thickness dependency of the displacement of the stretched portion 21. FIG. 4A shows the dependency of the displacement of the stretched portion 21 on the width w1 (see FIG. 1) when the thickness t1 (see FIG. 1) of the stretched portion 21 is fixed at 0.5 mm. FIG. 4B shows the dependency of the displacement of the stretched portion 21 on the thickness t1 when the width w1 of the stretched portion 21 is fixed at 4.6 mm. The displacement in the graphs of FIGS. 4A and 4B was calculated as the maximum displacement of the stretched portion 21.

[0061] As shown in FIG. 4A, when the width w1 of the extension 21 is 4 mm or more and 6 mm or less, the amount of displacement of the extension 21 can be kept small. Therefore, the width w1 of the extension 21 is preferably 4 mm or more and 6 mm or less. In addition, when the width w1 of the extension 21 is 4.6 mm, the amount of displacement of the extension 21 can be kept small. Part 2 Therefore, the amount of displacement of the stretched film 1 was the smallest. Part 2 The width w1 of 1 is preferably 4.6 mm.

[0062] As shown in FIG. 4B, when the thickness t1 of the extension portion 21 is 0.25 mm or more and 1 mm or less, the amount of displacement of the extension portion 21 can be kept small. Therefore, the thickness t1 of the extension portion 21 is preferably 0.25 mm or more and 1 mm or less. Furthermore, when the thickness t1 of the extension portion 21 is 0.5 mm, the amount of displacement of the extension portion 21 is smallest. Therefore, it is more preferable that the thickness t1 of the extension portion 21 is 0.5 mm.

[0063] [effect] The vibration device 1 according to the first embodiment can provide the following effects.

[0064] The vibration device 1 includes a light-transmitting body 10, a vibrating body 20, an extension portion 21, and a piezoelectric element 30. The vibrating body 20 is a cylindrical member having one end 20a, the other end 20b, and a sidewall 20c connecting the one end 20a and the other end 20b. The one end 20a is connected to the light-transmitting body 10 and vibrates the light-transmitting body 10. The extension portion 21 extends outward from the sidewall 20c of the vibrating body 20. The piezoelectric element 30 is disposed at the other end 20b of the vibrating body 20.

[0065] With this configuration, it is possible to provide a vibration device that can efficiently vibrate the light-transmitting body 10. The extensions 21 serve as vibration nodes, allowing the light-transmitting body 10 to be vibrated efficiently. Furthermore, even if foreign matter such as water droplets adheres to the extensions 21, the influence on the vibration of the light-transmitting body 10 can be reduced because the extensions 21 serve as vibration nodes. Furthermore, even if there is manufacturing variation, forming nodes in the extensions 21 allows vibration to be transmitted to the light-transmitting body 10 efficiently.

[0066] The extension 21 extends outward from one end 20a of the vibrating body 20. With this configuration, the amount of displacement of the extension 21 due to vibration can be reduced, and the vibration performance of the vibrating device 1 can be improved.

[0067] In the above-described embodiment, an example in which the extension portion 21 is ring-shaped has been described, but the shape of the extension portion 21 is not limited to this. The extension portion 21 may have any shape as long as it spreads outward from the side wall 20c of the vibrating body 20.

[0068] The imaging device 100 includes a vibration device 1 and an imaging element 60 disposed inside the vibration device 1.

[0069] With this configuration, it is possible to provide a highly reliable imaging device 100.

[0070] [Variations] 5 is a partial cross-sectional view showing a vibration device 1A according to a first modification of the first embodiment. As shown in FIG. 5, the extension 121 may be bent toward the other end 120b of the vibrating body 120. Alternatively, the vibrating body 120 may be formed in a cylindrical shape without the first protrusion and the second protrusion. Furthermore, the light-transmitting body 110 may be formed in a plate shape. In this case, the same effect as that of the first embodiment can be achieved with a simple configuration.

[0071] Fig. 6 is a partial cross-sectional view showing a vibration device 1B according to a second modification of the first embodiment. As shown in Fig. 6, the extension 221 may be bent toward one end 220a of the vibrating body 220. In this case, the same effect as in the first embodiment can be achieved with a simple configuration.

[0072] FIG. 7 is a partial cross-sectional view showing a vibration device 1C according to a third modification of the first embodiment. As shown in FIG. 7, the extension portion 321 may be formed to extend outward from one end 320a of the vibrating body 320. In the vibration device 1C, the extension portion 321 extends outward from a sidewall 320c on the one end 320a side of the vibrating body 320. The extension portion 321 is further composed of a first portion 321c, a second portion 321d, and a third portion 321e. The first portion 321c extends from the sidewall 320c of the vibrating body 320 in a direction perpendicular to the axial direction (Z direction) of the vibrating body 320. The second portion 321d extends from the first portion 321c toward the one end 320a. The third portion 321e extends from the second portion 321d in a direction perpendicular to the axial direction (Z direction) of the vibrating body 320. This configuration makes it easier for water droplets and the like adhering to the extension portion 321 to flow out. The second portion 321d may extend from the first portion 321c toward the other end 320b.

[0073] 7, the vibrating body 320 has a first protrusion 324 that protrudes inward from one end 320a and a second protrusion 325 that protrudes inward from the other end 320b. In the vibrating device 1C, the extension 321 and a part of the second protrusion 325 become vibration nodes. Therefore, a member such as a holder can be connected to the second protrusion 325 without affecting the vibration of the light-transmitting body 10.

[0074] (Embodiment 2) A vibration device according to a second embodiment of the present invention will be described. In the second embodiment, differences from the first embodiment will be mainly described. In the second embodiment, the same or equivalent configurations as in the first embodiment will be denoted by the same reference numerals. In the second embodiment, descriptions that overlap with the first embodiment will be omitted.

[0075] 8 is a partial cross-sectional view showing a vibration device 2 according to embodiment 2. Embodiment 2 differs from embodiment 1 in that weight 422 is disposed at the tip of extension portion 421.

[0076] In this embodiment, a weight 422 is arranged along the outer periphery of the second surface 421b of the extension portion 421. The weight 422 is formed in a ring shape along the outer periphery of the second surface 421b of the extension portion 421. The weight can be made of, for example, the same material as the extension portion 421. In this embodiment, the extension portion 421 and the weight 422 are integrally formed, but 4 The extension portion 421 and the weight 422 may be formed of different materials. In this case, the weight 422 formed of a different material may be attached to the extension portion 421.

[0077] By disposing the weight 422 on the extension portion 421, the amount of displacement of the extension portion 421 can be further reduced, and the vibration of the vibrating body 420 can be efficiently transmitted to the light-transmitting body 10. By disposing the weight 422 on the extension portion 421 formed in a plate shape to add weight, the amount of displacement of the extension portion 421 can be reduced. As a result, the vibration performance of the vibration device 2 can be improved.

[0078] As shown in Fig. 8, the vibration device 2 has a configuration in which a weight 422 is disposed on an extension 421 extending from one end 420a of a vibration body 420. Fig. 9A is a diagram showing the results of a simulation of the displacement distribution in the vibration device 2 of Fig. 8. The simulation was performed by piezoelectric analysis (resonance analysis) using Femtet manufactured by Murata Software Co., Ltd. The calculation conditions for the simulation of Fig. 9A are as follows: The material of the translucent body 10 is a piezoelectric material with a density of 2.48 g / cm 3 The material of the vibrating body 420 has a density of 7.75 g / cm3 and a Young's modulus of 73 GPa, which corresponds to soda glass. The diameter of the transparent body 10 is 14 mm. 3 and corresponds to SUS420J2 with a Young's modulus of 200 GPa. The piezoelectric element 30 has a density of 7.83 g / cm 3 A voltage of 60 Vp-p is applied to the top and bottom surfaces of piezoelectric element 30 (the surface in contact with vibrating body 420 and the surface opposite thereto). Piezoelectric element 30 has an outer diameter of 16 mm, an inner diameter of 10 mm, and a thickness of 1 mm. In FIG. 9A, the lighter the color, the greater the amount of displacement.

[0079] 9A, it can be seen that in the vibration device 2, the extension 421 and the weight 422 are vibration nodes. Furthermore, by disposing the weight 422 in the extension 421, the amount of displacement of the extension 421 can be further reduced compared to when the extension 421 does not have a weight. Furthermore, since the weight 422, in addition to the extension 421, serves as a vibration node, the vibration of the vibrating body 420 can be transmitted more efficiently to the translucent body 10. Furthermore, since the weight 422 also serves as a vibration node, even if a foreign object adheres to the weight 422, the vibration of the vibration device 2 is not affected and the vibration performance can be maintained.

[0080] 9B and 9C are diagrams showing the results of resonance analysis of vibrating body 420 of vibration device 2. FIG. 9B shows the case where the phase is 0°, and FIG. 9C shows the case where the phase is 180°. When vibrating body 420 has a configuration including first protruding portion 424 and second protruding portion 425, vibrating body 420 vibrates in a tuning fork resonance mode. In this case, two nodes are formed in vibrating body 420, symmetrical with respect to intermediate position in1 (see FIG. 8) between first protruding portion 424 and second protruding portion 425. One of the two nodes is extension portion 421 and weight 422, and the other node is a part of second protruding portion 425.

[0081] FIG. 10A is a graph showing the width dependency of the displacement of weight 422. FIG. 10B is a graph showing the thickness dependency of the displacement of weight 422. FIG. 10A shows the dependency on width w2 (see FIG. 8) of weight 422 when thickness t2 (see FIG. 8) of weight 422 is fixed at 3.5 mm. FIG. 10B shows the dependency on thickness t2 of weight 422 when width w2 of weight 422 is fixed at 2.5 mm. The displacement in the graphs of FIGS. 10A and 10B was calculated as the maximum displacement of weight 422. Width w2 of weight 422 is the length of weight 422 in the direction outward from side wall 420c of vibrating body 420. Thickness t2 of weight 422 is the length from first surface 421a of extension portion 421 to bottom end 422a (see FIG. 8) of weight 422.

[0082] As shown in FIG. 10A, when the width w2 of the weight 422 is 1 mm or more and 5 mm or less, the displacement of the weight 422 can be kept small. Therefore, the width w2 of the weight 422 is preferably 1 mm or more and 5 mm or less. Furthermore, when the width w2 of the weight 422 is 2.5 mm, the displacement of the weight 422 is smallest. Therefore, more preferably, the width w2 of the weight 422 is 2.5 mm It would be good if that were the case.

[0083] 10B, as the thickness t2 of weight 422 increases, the amount of displacement of weight 422 decreases. Therefore, the greater the thickness t2 of weight 422, the smaller the amount of displacement can be, and a good node can be formed. Therefore, the thickness t2 of weight 422 can be set to any value by trading off the size and vibration performance of vibration device 2.

[0084] [effect] According to the vibration device 2 of the second embodiment, the following effects can be achieved.

[0085] In the vibration device 2, a weight 422 is disposed on a second surface 421b of the extension part 421 on the side of the other end 420b of the vibrating body 420.

[0086] With this configuration, vibration nodes can be easily formed in the extensions 421, further improving vibration efficiency.

[0087] By disposing the weight 422 on the extension portion 421, it becomes easier to form a vibration node in the extension portion 421, and therefore the vibration of the vibrating body 420 can be transmitted more efficiently to the transparent body 10. Furthermore, because the weight 422 also becomes a vibration node, even if a foreign object adheres to the weight 422, it is possible to maintain the vibration performance without affecting the vibration of the vibrating device 2.

[0088] In the above-described embodiment, the weight 422 is disposed on the second surface 421b of the extension portion 421, but the present invention is not limited to this. In the extension portion 421, Vibration body4 20 on either the first surface 421a at one end 420a side or the second surface 421b at the other end 420b side.

[0089] In the above-described embodiment, an example in which one weight 422 is arranged on extension portion 421 has been described, but the present invention is not limited to this. A plurality of weights may be arranged on either first surface 421a or second surface 421b of extension portion 421. In this case, it is preferable that the weights are arranged at equal intervals.

[0090] [Variations] Fig. 11 is a partial cross-sectional view showing a vibration device 2A according to a first modification of the second embodiment. As shown in Fig. 11, weight 522 may be disposed at a position other than the tip of extension portion 521. Even with such a configuration, the same effects as those of the second embodiment can be achieved.

[0091] Fig. 12 is a partial cross-sectional view showing a vibration device 2B according to Modification 2 of Embodiment 2. As shown in Fig. 12, extension portion 621 has a configuration including first portion 621c, second portion 621d, and third portion 621e, and weight 622 may be disposed in third portion 621e. With this configuration, water droplets and the like adhering to extension portion 621 can easily flow outward.

[0092] (Embodiment 3) A vibration device 3 according to a third embodiment of the present invention will be described. In the third embodiment, differences from the second embodiment will be mainly described. In the third embodiment, the same or equivalent configurations as those in the second embodiment will be denoted by the same reference numerals. In the third embodiment, descriptions that overlap with those in the second embodiment will be omitted.

[0093] Fig. 13 is a perspective view showing a vibration device 3 according to a third embodiment. Fig. 14 is an exploded view of the vibration device 3 of Fig. 13. Fig. 15 is a cross-sectional view of the vibration device 3 of Fig. 13 taken along line AA. Fig. 16 is an enlarged view of a part of the vibration device 3 of Fig. 15.

[0094] 13 to 16, the vibration device 3 according to the third embodiment differs from the second embodiment in that it includes a cover 40 and a holding portion 50. The vibration device 3 according to the third embodiment also differs from the second embodiment in that a groove 723 is formed in a weight 722 and a seal member 62 is disposed in the groove 723.

[0095] 16, a groove 723 is formed in the surface of weight 722 (first surface 721a of extension portion 721). Groove 723 is formed in a ring shape along the outer periphery of weight 722 when viewed from the axial direction (Z direction) of vibrating body 720. A seal member 62 is disposed in groove 723. Sealing member 62 is, for example, an elastic member such as an O-ring.

[0096] <Cover> The cover 40 is a member that prevents foreign matter from entering the inside of the vibration device 3. The cover 40 has a hole 40a that exposes the light-transmitting body 10. The cover 40 is disposed outside the light-transmitting body 10, attached to the extension portion 721, and in contact with the surface of the weight 722.

[0097] 14, in this embodiment, cover 40 is formed in a plate shape having hole 40a. In this embodiment, cover 40 is brought into contact with extension 721, thereby making vibration device 3 waterproof.

[0098] 16, the end 40b of the cover 40 on the hole 40a side is formed in a tapered shape that reduces in thickness toward the light-transmitting body 10. By forming the end 40b of the cover 40 in such a shape, it is possible to cover the vibration device 3 without impairing the viewing angle of the imaging element, and the vibration device 3 This makes it possible to achieve both high performance and reliability.

[0099] Fig. 17 is a diagram showing the results of a simulation of the displacement distribution in the vibration device 3 of the third embodiment. The simulation was performed by piezoelectric analysis (resonance analysis) using Femtet manufactured by Murata Software Co., Ltd. The calculation conditions for the simulation of Fig. 17 are as follows: The material of the translucent body 10 is a piezoelectric material with a density of 2.48 g / cm 3 The material of the vibrating body 20 is equivalent to soda glass with a Young's modulus of 73 GPa. The diameter of the transparent body 10 is 14 mm. The material of the vibrating body 20 has a density of 7.75 g / cm. 3 and corresponds to SUS420J2 with a Young's modulus of 200 GPa. The piezoelectric element 30 has a density of 7.83 g / cm 3 A voltage of 60 Vp-p is applied to the top and bottom surfaces of the piezoelectric element 30 (the surface in contact with the vibrating body 20 and the surface opposite thereto). The piezoelectric element has an outer diameter of 16 mm, an inner diameter of 10 mm, and a thickness of 1 mm. In FIG. 17, the lighter the color, the greater the amount of displacement.

[0100] As shown in FIG. 17, the extension 721 and weight 722 have a displacement close to zero and barely vibrate. On the other hand, the displacement is greatest near the center of the translucent body 10. This shows that the vibration of the vibrating body 20 is prevented from escaping to the extension 721 and is transmitted to the translucent body 10. This makes it possible to efficiently remove foreign matter such as water droplets adhering to the translucent body 10. In this way, the extension 721 serves as a vibration node. In this embodiment, the cover 40 is brought into contact with the portion that serves as the vibration node, thereby achieving a waterproof structure while maintaining the vibration performance of the vibrating device 3.

[0101] 17, a part of the second protrusion 725 of the vibrating body 720 also serves as a vibration node. Therefore, by connecting the holding part 50 to a part of the second protrusion 725, it is possible to create a structure that holds the vibration device 3 while minimizing the impact on the vibration performance of the vibration device 3.

[0102] [effect] According to the vibration device 3 of the third embodiment, the following effects can be achieved.

[0103] The vibration device 3 further includes a cover 40 having a hole 40a that exposes the light-transmitting body 10, and is disposed outside the light-transmitting body 10, attached to the extension 721, and in contact with one weight 722. One weight 722 is formed in an annular shape. One weight 722 has a groove 723 formed in its surface in which a sealing member 62 is disposed.

[0104] This configuration prevents foreign matter such as water droplets from entering the inside of the vibration device 3 while maintaining the vibration performance of the vibration device 3, thereby improving the reliability of the vibration device 3, specifically its waterproof performance.

[0105] The end 40b of the cover 40 on the hole 40a side may be tapered so that the thickness decreases toward the light-transmitting body 10.

[0106] Depending on the viewing angle of the imaging element disposed inside the vibration device 3, the end 40b of the cover 40 can be formed in an appropriate shape.

[0107] [Variations] 18 is a partial cross-sectional view showing a vibration device 3A according to a first modification of the third embodiment. As shown in FIG. 18, the holding part 52 may have a base part 53 that protrudes outward from the other end 52b. In this case, the vibration device 3 A The vibration device 3 can be stably arranged on a substrate or the like. A The reliability of the system can be improved.

[0108] Fig. 19 is a partial cross-sectional view showing a vibration device 3B according to a second modification of the third embodiment. As shown in Fig. 19, the end 41b of the cover 41 on the hole side does not have to be tapered. The end 41b of the cover 41 can be shaped appropriately depending on the viewing angle of the imaging element placed inside the vibration device 3B.

[0109] FIG. 20 is a partial cross-sectional view showing a vibration device 3C according to a third modification of the third embodiment. 20As shown in Fig. 1, the cover 42 may be formed to be curved. By forming the cover 42 to be curved, the waterproof performance of the vibration device 3C can be improved, and the reliability can be increased.

[0110] Fig. 21 is a partial cross-sectional view showing a vibration device 3D according to Modification 4 of Embodiment 3. As shown in Fig. 21, a groove 723a may be formed in a side surface 722b of a weight 722, and a seal member 62 may be disposed in the groove 723a.

[0111] (Fourth embodiment) A vibration device according to a fourth embodiment of the present invention will be described. In the fourth embodiment, differences from the first embodiment will be mainly described. In the fourth embodiment, the same or equivalent configurations as those in the first embodiment will be denoted by the same reference numerals. In the fourth embodiment, descriptions that overlap with those in the first embodiment will be omitted.

[0112] 22 is a cross-sectional view showing a vibration device 4 according to embodiment 4. Embodiment 4 differs from embodiment 1 in that vibration device 4 includes a retainer 826. Embodiment 4 also differs from embodiment 1 in that retainer 826 is provided with an extension 821.

[0113] 22, the vibration device 4 includes a retainer 826 arranged on one end 820a side of the vibrating body 820. The retainer 826 is a member for fixing the light-transmitting body 810 to the vibrating body 820. The light-transmitting body 810 can be fixed by sandwiching it between the retainer 826 and the vibrating body 820.

[0114] The retainer 826 has a first member 826a and a second member 826c. The first member 826a is a cylindrical member attached to a side wall 820c of the vibrating body 820. In this embodiment, the first member 826a is formed to extend inward from one end 826e of the retainer 826. The second member 826c extends inward from an inner surface 826b of the first member 826a and comes into contact with a surface 810b of the light-transmitting body 810 opposite to a surface 810a that connects to the vibrating body.

[0115] In this embodiment, the extension 821 is provided at the other end 826f of the retainer 826, extending outward from the outer surface 826d of the first member 826a. 8 8. In the axial direction (Z direction) of vibrating body 820, extension portion 821 is positioned at approximately the same height as one end 820a of vibrating body 820. Therefore, in the axial direction (Z direction) of vibrating body 820, one end 820a of vibrating body 820 and extension portion 821 are disposed at approximately the same height. In addition, weight 822 is provided at the tip of extension portion 821.

[0116] [effect] The vibration device 4 according to the fourth embodiment can provide the following effects.

[0117] The vibration device 4 includes a retainer 826 disposed on one end 820a side of the vibrating body 820. The retainer 826 has a first member 826a and a second member 826c. The first member 826a is a cylindrical member attached to a side wall 820c of the vibrating body 820. The second member 826c extends inward from an inner surface 826b of the first member 826a and is connected to a surface 810a of the light-transmitting body 810 opposite to a surface 810a that connects to the vibrating body 820. 1 The extension 821 is provided so as to extend outward from an outer surface 826d of the first member 826a of the retainer 826.

[0118] With this configuration, the light-transmitting body 810 can be firmly held, and the vibration of the vibrating body 820 can be efficiently transmitted to the light-transmitting body 810.

[0119] [Variations] Fig. 23 is a partial cross-sectional view showing a vibration device 4A according to a first modification of the fourth embodiment. As shown in Fig. 23, the extension 921 may be provided outward from any position on the outer surface 926d of the first member 926a of the retainer 926. Even in this case, the extension 921 and the weight 922 become vibration nodes, and the same effect as in the fourth embodiment can be achieved. [Industrial Applicability]

[0120] The vibration device of the present invention can be applied to an in-vehicle camera used outdoors, a surveillance camera, or an optical sensor such as a LiDAR. [Explanation of symbols]

[0121] 1, 1A~1B, 2, 2A~2C, 3, 3A~3B, 4, 4A Vibration device 10, 210, 810 Translucent body 20, 120, 220, 320, 420, 520, 820 vibrator 21, 121, 221, 321, 421, 521, 621, 721, 821, 921 Extension part 4 22, 522, 622, 722, 822, 922 weights twenty four, 324、424 1st protrusion twenty five, 325、425、725 2nd protrusion 30 Piezoelectric element 40, 41, 42 Cover 40 a hole 50, 52 Holding part 60 image sensor 62 Sealing material 100 Imaging device 826, 926 retainer

Claims

1. A transparent body; a vibrating body that is a cylindrical member having one end, the other end, and a side wall connecting the one end and the other end, the vibrating body being connected to the light-transmitting body at the one end and vibrating the light-transmitting body; an extension portion extending outward from the side wall of the vibrating body; a piezoelectric element disposed at the other end of the vibrating body; Equipped with a plurality of weights are arranged on at least one of a first surface on the one end side or a second surface on the other end side of the extension portion; The plurality of weights are disposed at equal intervals on the extension portion when viewed from the axial direction of the vibrating body. Vibration device.

2. A transparent body, a vibrating body that is a cylindrical member having one end, the other end, and a side wall connecting the one end and the other end, the vibrating body being connected to the light-transmitting body at the one end and vibrating the light-transmitting body; an extension portion extending outward from the side wall of the vibrating body; a piezoelectric element disposed at the other end of the vibrating body; a weight disposed on at least one of a first surface on the one end side and a second surface on the other end side of the extension portion; a cover having a hole for exposing the light-transmitting body, the cover being disposed outside the light-transmitting body, attached to the extension portion, and in contact with a surface of the one weight; Equipped with The one weight is formed in a ring shape, The one weight has a seal member disposed in a groove provided on the surface. Vibration device.

3. The extension portion is bent toward the one end side or the other end side. The vibration device according to claim 1 or 2.

4. The extension portion extends outward from the one end side of the vibrating body. The vibration device according to claim 1 or 2.

5. The extension portion extends outward from the one end of the vibrating body. The vibration device according to claim 1 or 2.

6. moreover, a retainer including: a cylindrical first member disposed on the one end side of the vibrating body and attached to the side wall of the vibrating body; and a second member extending inward from an inner surface of the first member and contacting a surface of the light-transmitting body opposite to a surface connected to the vibrating body; Equipped with The extension portion is provided to extend outward from an outer surface of the first member of the retainer. The vibration device according to claim 1 or 2.

7. The end of the cover on the hole side is formed in a tapered shape so that the thickness decreases toward the light-transmitting body. The vibration device according to claim 2 .

8. The vibrator has a first protruding portion protruding inward from the one end and a second protruding portion protruding inward from the other end. The vibration device according to claim 1 or 2.

9. A transparent body; a vibrating body that is a cylindrical member having one end, the other end, and a side wall connecting the one end and the other end, the vibrating body being connected to the light-transmitting body at the one end and vibrating the light-transmitting body; an extension portion extending outward from the side wall of the vibrating body; a piezoelectric element disposed at the other end of the vibrating body; Equipped with the extension portion is located on the one end side of the vibrating body and is located outside the light-transmitting body when viewed from the axial direction of the vibrating body. Vibration device.

10. A vibration device according to claim 1, 2 or 9; an imaging element disposed inside the vibration device; Equipped with Imaging device.

Images