Vibration device and imaging device

Abstract

According to the present disclosure, provided are: a vibration device capable of removing foreign matter adhered to the surface of a translucent body by a method other than atomization; and an imaging device. A vibration device (10) comprises: an outermost layer lens (1) (translucent body) that transmits light of a predetermined wavelength; a vibrating body (3) that contacts the outermost layer lens (1) and vibrates the outermost layer lens (1); a piezoelectric element (5) provided to the vibrating body (3); and a housing (2) that retains the outermost layer lens (1) and covers the vibrating body (3). The vibrating body (3) includes: a first cylindrical part (31) that has a cylindrical shape and contacts the outermost layer lens (1); a second cylindrical part (32) that is provided with the piezoelectric element (5); a spring part (33) that connects the first cylindrical part (31) and the second cylindrical part (32) and has a curved cross-sectional shape; and an unbalancing means that generates an unevenness in the vibration of the outermost layer lens (1).

Description

Vibration device and imaging device

[0001] The present disclosure relates to a vibration device and an imaging device.

[0002] In recent years, vehicles have been equipped with imaging devices at the front or rear of the vehicle to control safety devices and drive assistance controls using images obtained by the imaging devices. Such imaging devices are often installed outside the vehicle, and foreign matter such as raindrops (water droplets), mud, and dust adheres to the transparent bodies (protective covers and lenses) that cover the exterior.

[0003] If foreign matter adheres to the light-transmitting body, the foreign matter will be reflected in the image captured by the imaging device, making it difficult to obtain a clear image. Therefore, in Japanese Patent Laid-Open No. 2017-170303 (Patent Document 1), an imaging device is provided with a droplet removal device (vibration device) that vibrates the light-transmitting body in order to remove foreign matter adhered to the surface of the light-transmitting body.

[0004] Japanese Patent Application Laid-Open No. 2017-170303

[0005] When vibrating a transparent body to remove foreign matter adhering to its surface, the vibration device collects the foreign matter at the position of the transparent body where the displacement is greatest, and then atomizes and removes the collected foreign matter through vibration. However, if the foreign matter has a high viscosity and cannot be atomized and adheres to the surface of the transparent body, the foreign matter simply collects in the center of the transparent body and cannot be atomized, resulting in obstruction of the field of view. While the method of atomizing and removing foreign matter by vibrating the transparent body using a vibration device is effective, there is a need for an additional method for removing foreign matter adhering to the surface of the transparent body other than atomization.

[0006] Therefore, an object of the present disclosure is to provide a vibration device and an imaging device that can remove foreign matter adhering to the surface of a light-transmitting body by a method other than atomization.

[0007] A vibration device according to one aspect of the present disclosure includes a translucent body that transmits light of a predetermined wavelength, a vibrating body that contacts the translucent body and vibrates the translucent body, a piezoelectric element provided on the vibrating body, and a housing that holds the translucent body and covers the vibrating body. The vibrating body is cylindrical and includes a first cylindrical portion that contacts the translucent body, a second cylindrical portion that is provided with the piezoelectric element, a spring portion that connects the first cylindrical portion and the second cylindrical portion and has a curved cross-sectional shape, and imbalance means that causes a bias in the vibration of the translucent body.

[0008] An imaging device according to an embodiment of the present disclosure includes the vibration device described above and an imaging element arranged so that the light-transmitting body is in the field of view.

[0009] According to the present disclosure, the vibration device includes an imbalance means that causes a bias in the vibration of the light-transmitting body, thereby making it possible to remove foreign matter adhering to the surface of the light-transmitting body by a method other than atomization.

[0010] Fig. 1 is a cross-sectional view of an imaging device according to an embodiment. Fig. 2 is a perspective view for explaining the configuration of a vibration device according to an embodiment. Fig. 3 is a cross-sectional view for explaining displacement occurring in a vibration device according to an embodiment. Fig. 4 is a cross-sectional view for explaining displacement occurring in a vibration device according to an embodiment. Fig. 5 is a cross-sectional view of an imaging device according to a first modified example. Fig. 6 is a perspective view for explaining the configuration of a vibration device according to a second modified example. Fig. 7 is a perspective view for explaining the configuration of a vibration device according to a third modified example.

[0011] The imaging device according to the present disclosure will be described in detail below with reference to the drawings. Note that the same reference numerals in the drawings indicate the same or corresponding parts. The imaging device described below is, for example, for vehicle installation, and can vibrate a transparent body (e.g., the outermost lens) to remove foreign matter adhering to the surface of the transparent body. The imaging device is not limited to vehicle installation. For example, the imaging device can also be applied to security surveillance cameras, drones, etc.

[0012] (Embodiment) Fig. 1 is a cross-sectional view of an imaging device 100 according to an embodiment. Fig. 2 is a perspective view of a vibration device 10 according to an embodiment. Note that the X, Y, and Z directions in the figure indicate the horizontal, depth, and height directions of the imaging device 100, respectively. The imaging device 100 includes a vibration device 10 and a sensor device 20. The vibration device 10 includes an outermost lens 1, a housing 2, a vibrating body 3, and a piezoelectric element 5. The sensor device 20 includes a bracket 8 that holds an imaging element 6. Although not shown, it is preferable that the imaging device 100 has an inner lens between the outermost lens 1 and the imaging element 6.

[0013] After adjusting the alignment between the outermost lens 1 and the imaging element 6, the sensor device 20 is bonded to the vibration device 10 to form the imaging device 100. The imaging element 6 is an image sensor such as a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) sensor, and is mounted on a circuit board (not shown). The circuit board may be mounted with semiconductor elements such as a general-purpose integrated circuit (IC) or application-specific integrated circuit (ASIC) that control the imaging element 6, as well as semiconductor elements that generate signals to drive the piezoelectric element 5. The circuit board is fixed to the bracket 8 at a position where the alignment between the outermost lens 1 and the inner lens (not shown) and the imaging element 6 has been adjusted. The bracket 8 is made of, for example, aluminum (A5052).

[0014] The outermost lens 1 is a translucent body that transmits light of a predetermined wavelength (e.g., a wavelength of visible light, a wavelength that can be captured by an imaging element, etc.), and is made of, for example, borosilicate crown glass (BK7), quartz glass, crown glass, flint glass, a convex meniscus lens, etc. Note that the vibration device 10 may use a transparent member such as a protective cover instead of the outermost lens 1. The protective cover is made of glass or a resin such as transparent plastic.

[0015] The end of the outermost lens 1 is held by an end 2b of a cylindrical first portion 2a extending in the Z direction. The end 2b of the first portion 2a contacts the outermost lens 1 via a retainer 21. The retainer 21 may be made of a resin such as polyphenylene sulfide (PPS) or a metal such as stainless steel (SUS304, SUS420, SUS440). The end 2b of the first portion 2a, the retainer 21, the outermost lens 1, and the vibrating body 3 are bonded together, for example, with an adhesive. In FIG. 1 , the housing 2 indirectly holds the outermost lens 1 via the retainer 21, but the outermost lens 1 may also be held directly by the end 2b of the first portion 2a.

[0016] The housing 2 includes a first portion 2a, a cylindrical second portion 2c having a larger diameter than the first portion 2a, and a third portion 2d connecting the first portion 2a and the second portion 2c. The third portion 2d has a disk shape that extends in the radial direction (X and Y directions) of the first portion 2a. The housing 2 has a shape in which two cylinders (the first portion 2a and the second portion 2c) with different diameters are connected by a disk (the third portion 2d).

[0017] The first portion 2a has a shape that extends in the axial direction of the cylinder (Z direction), and as described below, it can elastically deform like a spring in the radial direction of the cylinder (X and Y directions) to suppress vibration in those directions. The second portion 2c is provided with a weight 2e to suppress vibration from the vibrating body 3. The first portion 2a, end portion 2b, second portion 2c, third portion 2d, and weight 2e of the housing 2 may be formed integrally or separately. The housing 2 is made of, for example, stainless steel (SUS304, SUS420, SUS440), etc.

[0018] As shown in Figure 1, the vibration device 10 is in contact with a vibrating body 3 to vibrate the outermost lens 1. The vibrating body 3 is cylindrical and is composed of a first cylindrical portion 31 that is in contact with the outermost lens 1, a second cylindrical portion 32 in which a piezoelectric element 5 is provided, and a spring portion 33 that connects the first cylindrical portion 31 and the second cylindrical portion 32. The cross section of the spring portion 33 is S-shaped. An inner lens (not shown) may be placed inside the cylinder of the vibrating body 3. The vibrating body 3 is made of, for example, stainless steel (SUS304, SUS420, SUS440) or the like.

[0019] First cylindrical portion 31 is a cylindrical portion that is elongated in the axial direction of the tube (Z direction), and has end portion 2b that contacts the peripheral edge of outermost lens 1, transmitting the vibration of vibrating body 3 to outermost lens 1. First cylindrical portion 31 has end portion 2b that is elongated in the radial direction of the tube (X and Y directions) to stably hold outermost lens 1.

[0020] The second cylindrical portion 32 is a portion that vibrates together with the vibration of the piezoelectric element 5, and has a thickness greater than the thicknesses of the first cylindrical portion 31 and the spring portion 33. This makes it easier to transmit the vibration of the piezoelectric element 5 to the outermost lens 1 more efficiently.

[0021] The spring portion 33 supports the first cylindrical portion 31 and transmits vibrations of the second cylindrical portion 32 to the first cylindrical portion 31. The first cylindrical portion 31, the second cylindrical portion 32, and the spring portion 33 may be formed integrally or separately. Although the cross-sectional shape of the spring portion 33 has been described as being S-shaped, any curved shape (e.g., a shape of two connected S-shapes) that can transmit vibrations of the second cylindrical portion 32 to the first cylindrical portion 31 may be used.

[0022] The imaging device 100 may be mounted on a device (e.g., a vehicle) so that the axial direction (Z direction) of the cylinder is approximately 90 degrees relative to the direction of gravity. In such cases, foreign matter (e.g., raindrops) may enter through the gap between the outermost lens 1 and the housing 2 and adhere to the vibrating body 3. Adhering foreign matter to the vibrating body 3 damps the vibration of the vibrating body 3, reducing the vibration performance of the vibration device 10. Therefore, the cross-sectional shape of the spring portion 33 in the vibration device 10 is curved, allowing any intruding foreign matter to move along the curvature of the curved shape and slide off the vibrating body 3 under its own weight. In particular, the spring portion 33 is preferably shaped to have a radially bulging portion relative to the first cylindrical portion 31 and the second cylindrical portion 32. This allows the vibration device 10 to move any intruding foreign matter in the direction of gravity along the curvature of the spring portion 33, making it easier for the foreign matter to slide off the vibrating body 3 under its own weight.

[0023] The piezoelectric element 5 is provided on the surface of the second cylindrical portion 32 opposite to the side in contact with the outermost lens 1. The piezoelectric element 5 is hollow and circular, and vibrates by being polarized in the thickness direction, for example. The piezoelectric element 5 is made of lead zirconate titanate piezoelectric ceramics. However, (K,Na)NbO ３ Other piezoelectric ceramics such as LiTaO may also be used. ３ A piezoelectric single crystal such as

[0024] The hollow circular piezoelectric element 5 vibrates in the radial direction, and this vibration is converted by the spring portion 33 of the vibrating body 3 into vibration in the Z direction (up and down in the figure), causing the outermost lens 1 to vibrate in the Z direction. The vibration device 10 vibrates the outermost lens 1 in the Z direction so that the central portion of the outermost lens 1 is displaced to the maximum extent, and thereby moves foreign matter adhering to the surface of the outermost lens 1 to the central portion of the outermost lens 1, where it is atomized and removed. However, the vibration device 10 cannot remove foreign matter with high viscosity by simply moving the foreign matter to the central portion of the outermost lens 1 and atomizing and removing the foreign matter. Therefore, in addition to atomizing and removing the foreign matter, the vibration device 10 biases the vibration of the outermost lens 1, causing the adhering foreign matter to slide off the outermost lens 1 and be removed.

[0025] The vibration device 10 is provided with an unbalance means for adding mass to at least a portion of the vibrating body 3 in order to bias the vibration of the outermost lens 1. Specifically, as shown in Fig. 1, the vibration device 10 is provided with a weight 4 on the first cylindrical portion 31. The weight 4 is not disposed around the entire circumference of the first cylindrical portion 31, but is provided only on a portion thereof, and has a semicircular shape that extends halfway around the circumference of the first cylindrical portion 31 as shown in Fig. 2.

[0026] The weight 4 is not limited to any material as long as it can add mass to a part of the first cylindrical portion 31, and may be made of the same material as the first cylindrical portion 31 or a different material. If the specific gravity of the material of the weight 4 is greater than the specific gravity of the material of the first cylindrical portion 31, the weight 4 can be made smaller, and the space required to install the weight 4 can be reduced. The weight 4 may be made up of multiple pieces, and may be formed integrally with the first cylindrical portion 31 or formed separately.

[0027] By providing the weight 4 on a portion of the first cylindrical portion 31 of the vibration device 10, when the outermost lens 1 is vibrated in the Z direction, the displacement differs between the side with the weight 4 and the side without the weight 4, thereby generating a bias in the vibration of the outermost lens 1. FIG. 3 is a perspective view illustrating the displacement that occurs in the vibration device 10 according to the embodiment. FIG. 4 is a cross-sectional view illustrating the displacement that occurs in the vibration device 10 according to the embodiment. FIGS. 3 and 4 show the results of a simulation in which a voltage is applied to the piezoelectric element 5 in the vibration device 10 to vibrate the outermost lens 1. Note that in FIGS. 3 and 4, the magnitude of the displacement is indicated by the shade of hatching, with darker hatching indicating areas with greater displacement. In the vibration device 10 shown in FIGS. 3 and 4, the displacement at the portion with the greatest displacement is approximately 8 μm.

[0028] As can be seen from Figures 3 and 4, the vibration device 10 shows large displacement of the outermost lens 1 and first cylindrical portion 31. Specifically, the displacement of the outermost lens 1 and first cylindrical portion 31 on the side where the weight 4 is provided (the right side in the figure) is greater than the displacement of the outermost lens 1 and first cylindrical portion 31 on the side where the weight 4 is not provided (the left side in the figure). As a result, the vibration device 10 vibrates with the side where the weight 4 is not provided rising or falling relative to the side where the weight 4 is provided, causing the outermost lens 1 to tilt. By vibrating the outermost lens 1 at a tilt, any foreign matter adhering to the outermost lens 1 can be removed by sliding it off the outermost lens 1. It is preferable that a water-repellent or hydrophilic coating material be applied to the surface of the outermost lens 1.

[0029] 3 and 4, the vibration device 10 vibrates the outermost lens 1 by elastically deforming the first portion 2a and the third portion 2d of the housing 2 like a spring, while suppressing leakage of vibration to the second portion 2c of the housing 2. In particular, the first portion 2a of the housing 2 absorbs displacement in the X direction caused by tilting and vibrating the outermost lens 1 by elastically deforming like a spring, thereby suppressing vibration leakage to the second portion 2c of the housing 2. Furthermore, the third portion 2d of the housing 2 absorbs displacement in the Z direction caused by vibration of the outermost lens 1 in the Z direction by elastically deforming like a spring, thereby suppressing vibration leakage to the second portion 2c of the housing 2.

[0030] 3 and 4, the second portion 2c of the housing 2 hardly displaces even when the outermost lens 1 is vibrated, and it is clear that the vibration of the vibrating body 3 does not leak out. Therefore, by holding the second portion 2c of the housing 2 with a member on the vehicle side, the imaging device 100 can be attached to the vehicle without transmitting the vibration of the vibrating device 10 to the vehicle side. Note that the second portion 2c of the housing 2 has a weight 2e on the surface facing the vibrating body 3, and the weight 2e acts as inertial resistance to suppress the vibration from the vibrating body 3.

[0031] (Variation 1) As shown in Fig. 1, the vibration device 10 has the weight 4 provided on the first cylindrical portion 31. However, the position where the weight 4 is provided is not limited to the first cylindrical portion 31, and it may be at any position on the vibration body 3. Fig. 5 is a cross-sectional view of an imaging device 100a according to Variation 1. Note that in the imaging device 100a, components similar to those of the imaging device 100 shown in Fig. 1 are denoted by the same reference numerals, and description thereof will not be repeated.

[0032] The vibration device 10a is provided with an imbalance means for adding mass to at least a portion of the vibrating body 3 in order to bias the vibration of the outermost lens 1. Specifically, as shown in FIG. 5 , the vibration device 10a is provided with a weight 4 on the second cylindrical portion 32. The weight 4 is not disposed around the entire circumference of the second cylindrical portion 32 but is provided only on a portion thereof, and for example, has a semicircular shape that extends halfway around the circumference of the second cylindrical portion 32. When providing the weight 4 on the second cylindrical portion 32, it is necessary to ensure space for the weight 4 so that it does not interfere with the weight 2e provided on the second portion 2c of the housing 2. This reduces the space required for the weight 2e provided on the second portion 2c of the housing 2.

[0033] The weight 4 is not limited to any material as long as it can add mass to a portion of the second cylindrical portion 32, and may be made of the same material as the second cylindrical portion 32 or a different material. If the specific gravity of the material of the weight 4 is greater than the specific gravity of the material of the second cylindrical portion 32, the weight 4 can be made smaller, and the space required to install the weight 4 can be reduced. The weight 4 may be made up of multiple pieces, and may be formed integrally with the second cylindrical portion 32 or formed separately.

[0034] The position where the weight 4 is provided is not limited to the first cylindrical portion 31 and the second cylindrical portion 32, but may be the spring portion 33. Furthermore, the weight 4 may be provided in multiple locations, such as the first cylindrical portion 31 and the second cylindrical portion 32, respectively. In this case, the weight of the weight 4 may be changed depending on the location. Furthermore, the weight 4 is not limited to being provided on the outer surface of the vibrating body 3 (the side facing the housing 2), but may be provided on the inner surface of the vibrating body 3.

[0035] (Variation 2) In the vibration device 10, a mass is added to at least a portion of the vibrating body 3 as unbalance means. However, the unbalance means may be such that at least a portion of the mass of the vibrating body 3 is removed. Fig. 6 is a perspective view for explaining the configuration of a vibration device 10b according to Variation 2. Note that in the vibration device 10b, components similar to those of the vibration device 10 shown in Fig. 2 are given the same reference numerals, and their description will not be repeated. Furthermore, components of the vibration device 10b not shown in Fig. 6 are the same as those of the vibration device 10 shown in Fig. 1.

[0036] The vibration device 10b is in contact with the vibrating body 3a to vibrate the outermost lens 1. The vibrating body 3a is cylindrical and is composed of a first cylindrical portion 31 that is in contact with the outermost lens 1, a second cylindrical portion 32 that is provided with a piezoelectric element 5, and a spring portion 33 that connects the first cylindrical portion 31 and the second cylindrical portion 32.

[0037] Furthermore, the vibration device 10b is provided with an imbalance means for removing at least a portion of the mass of the vibrating body 3a in order to bias the vibration of the outermost lens 1. Specifically, as shown in Fig. 6, the vibrating body 3a has a notch 31a that cuts out a portion of the first cylindrical portion 31. The notch 31a is formed by cutting away a portion of the vibrating body 3a on the left side in the figure.

[0038] The side of the first cylindrical portion 31 where the cutout 31a is provided (left side in the figure) is lighter than the side where the cutout 31a is not provided (right side in the figure). Therefore, the displacement of the outermost lens 1 and first cylindrical portion 31 on the side where the cutout 31a is provided is greater than the displacement of the outermost lens 1 and first cylindrical portion 31 on the side where the cutout 31a is not provided. Therefore, in the vibration device 10b, the side where the cutout 31a is provided rises or falls more than the side where the cutout 31a is not provided, causing the outermost lens 1 to tilt and vibrate. By tilting and vibrating the outermost lens 1, any foreign matter adhering to the outermost lens 1 can be removed by sliding it off the outermost lens 1.

[0039] The position where the notch 31a is provided is not limited to the first cylindrical portion 31, but may also be the second cylindrical portion 32 or the spring portion 33. Furthermore, the notch 31a may be provided in multiple locations, for example, by providing the notch 31a in each of the first cylindrical portion 31 and the second cylindrical portion 32. In this case, the mass removed by the notch 31a may be varied depending on the location. Furthermore, the notch 31a is not limited to being provided on the outer surface (the side facing the housing 2) of the vibrating body 3a, but may also be provided on the inner surface of the vibrating body 3a. Furthermore, the vibrating body 3a may be provided with a combination of a notch and a weight. For example, the first cylindrical portion 31 may have a notch and the second cylindrical portion 32 may have a weight.

[0040] (Variation 3) As shown in FIG. 1 , the vibration device 10 employs a vibrating body 3 in which the cross-sectional shape of the spring portion 33 is S-shaped. However, the structure of the vibrating body is not limited to a structure in which the cross-sectional shape of the spring portion 33 is S-shaped. FIG. 7 is a perspective view for explaining the configuration of a vibration device 10c according to Variation 3. Note that in the vibration device 10c, components similar to those in the vibration device 10 shown in FIG. 1 are given the same reference numerals, and their description will not be repeated. Furthermore, the components of the vibration device 10c not shown in FIG. 7 are the same as those in the vibration device 10 shown in FIG. 1.

[0041] As shown in Fig. 7, the vibrating body 3b has a cylindrical shape. The vibrating body 3b is composed of a first cylindrical portion 31 that contacts the outermost lens 1, a second cylindrical portion 32 that has the piezoelectric element 5 provided therein, and a spring portion 33a that connects the first cylindrical portion 31 and the second cylindrical portion 32. The first cylindrical portion 31, the second cylindrical portion 32, and the spring portion 33a may be formed integrally or separately.

[0042] The spring portion 33a is a side portion of the vibrating body 3b, and multiple grooves 30 each having a horizontal Y shape (tuning fork shape) are formed in the spring portion 33a at equal intervals in the circumferential direction of the vibrating body 3b. The grooves 30 penetrate the spring portion 33a and are openings that penetrate the vibrating body 3b in the radial direction.

[0043] The groove 30 has a horizontal Y-shape (tuning fork shape) and is symmetrical about the radial axis of the vibrating body 3b. The groove 30 is formed so that one end contacts the first cylindrical portion 31 and the other end contacts the second cylindrical portion 32. The portion of the spring portion 33a that remains due to the provision of the groove 30 becomes a plurality of U-shaped pillars 35 that connect the first cylindrical portion 31 and the second cylindrical portion 32. The pillars 35 function as springs that vibrate the outermost lens 1 in the Z direction.

[0044] Pillar 35 has a horizontal U-shape. As shown in Fig. 7, pillar 35 has a shape in which the connection portion with first cylindrical portion 31 and the connection portion with second cylindrical portion 32 are arranged on a substantially straight line. Therefore, vibration of piezoelectric element 5 causes vibrating body 3b to narrow or widen the U-shaped portion of pillar 35, thereby vibrating outermost lens 1 in the Z direction.

[0045] Furthermore, as shown in Fig. 7, the vibration device 10c has a weight 4 attached to the first cylindrical portion 31 as an unbalance means. The weight 4 is not disposed around the entire circumference of the first cylindrical portion 31, but is attached only to a portion thereof, and has a semicircular shape that runs halfway around the circumference of the first cylindrical portion 31. As a result, the side of the vibration device 10c without the weight 4 rises or falls higher or lower than the side with the weight 4, causing the outermost lens 1 to vibrate at an angle. By vibrating the outermost lens 1 at an angle, any foreign matter adhering to the outermost lens 1 can be removed by sliding it off the outermost lens 1.

[0046] The imbalance means provided in the vibration device 10c may be a notch. The structure of the vibration body 3b shown in Figure 7 is also an example, and any structure that vibrates the outermost lens 1 in the Z direction may be used.

[0047] (Other Modifications) The configurations described in the vibration device according to the above-described embodiment and the vibration device according to the above-described modification can be combined as appropriate. Furthermore, the imbalance means may cause bias in the vibration of the outermost lens 1 by a method other than a weight or a notch (for example, by forming the vibrating body 3 partially from different materials, by varying the thickness of the portion of the spring portion 33 where the cross section is curved (for example, S-shaped), or by varying the voltage applied to the piezoelectric element 5 in each region). Furthermore, the imaging device according to the above-described embodiment may include a camera, LiDAR, radar, etc. Furthermore, multiple imaging devices may be arranged side by side.

[0048] The imaging device according to the above-described embodiment is not limited to an imaging device installed in a vehicle, but can be similarly applied to any imaging device that includes an optical device and an imaging element arranged so that a light-transmitting body is in the field of view, and that requires removal of foreign matter from the light-transmitting body.

[0049] (Aspects) (1) A vibration device according to the present disclosure includes a translucent body that transmits light of a predetermined wavelength, a vibrating body that contacts the translucent body and vibrates the translucent body, a piezoelectric element provided on the vibrating body, and a housing that holds the translucent body and covers the vibrating body, wherein the vibrating body is cylindrical and includes a first cylindrical portion that contacts the translucent body, a second cylindrical portion that is provided with the piezoelectric element, a spring portion that connects the first cylindrical portion and the second cylindrical portion and has a curved cross-sectional shape, and imbalance means that causes a bias in the vibration of the translucent body.

[0050] As a result, the vibration device according to the present disclosure includes an imbalance means for causing a bias in the vibration of the light-transmitting body, and can remove foreign matter adhering to the surface of the light-transmitting body by a method other than atomization.

[0051] (2) In the vibration device described in (1), the unbalance means is a cutout portion in at least one of the first cylindrical portion, the second cylindrical portion, and the spring portion, thereby eliminating at least a portion of the mass of the vibrating body.

[0052] (3) In the vibrating device described in (1) or (2), the unbalancing means is a weight that adds mass to a portion of at least one of the first cylindrical portion, the second cylindrical portion, and the spring portion.

[0053] (4) In the vibrating device described in (3), the weight is attached to at least the first cylindrical portion. (5) In the vibrating device described in (3) or (4), the weight has a semicircular shape that extends halfway around the circumference of the first cylindrical portion.

[0054] (6) In the vibrating device according to any one of (3) to (5), the specific gravity of the material of the weight is greater than the specific gravity of the material of the vibrating body.

[0055] (7) In the vibrating device according to any one of (3) to (6), the weight is formed integrally with the vibrating body.

[0056] (8) In the vibration device according to any one of (1) to (7), the spring portion has an S-shaped cross section.

[0057] (9) In the vibration device described in any one of (1) to (8), the spring portion has a shape that has a portion that bulges out in the radial direction of the first cylindrical portion relative to the first cylindrical portion.

[0058] (10) In the vibration device described in any one of (1) to (9), the second cylindrical portion has a portion whose shape is extended in the radial direction of the second cylindrical portion, and a piezoelectric element is provided in that portion.

[0059] (11) In the vibration device described in any one of (1) to (10), the housing is cylindrical and includes a first part that holds the translucent body, a second part that has a larger diameter than the first part, and a third part that extends radially from the first part and connects the first part and the second part.

[0060] (12) In the vibrating device described in (11), the first portion has a shape that is extended in the axial direction of the tube.

[0061] (13) In the vibrating device according to (11) or (12), the third portion has a weight on a surface facing the vibrating body.

[0062] (14) An imaging device according to the present disclosure includes the vibration device according to any one of (1) to (13) and an imaging element arranged so that the light-transmitting body is in the field of view.

[0063] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0064] 1 Outermost lens, 2 Housing, 2a First portion, 2b End portion, 2c Second portion, 2d Third portion, 2e, 4 Weight, 3, 3a, 3b Vibrating body, 5 Piezoelectric element, 6 Imaging element, 8 Bracket, 10, 10a to 10c Vibration device, 20 Sensor device, 21 Retainer, 30 Groove portion, 31 First cylindrical portion, 31a Notch portion, 32 Second cylindrical portion, 33, 33a Spring portion, 35 Pillar, 100, 100a Imaging device.

Claims

1. A vibration device comprising: a translucent body that transmits light of a predetermined wavelength; a vibrating body in contact with the translucent body and vibrating the translucent body; a piezoelectric element provided on the vibrating body; and a housing that holds the translucent body and covers the vibrating body, wherein the vibrating body is cylindrical and includes a first cylindrical section in contact with the translucent body, a second cylindrical section in which the piezoelectric element is provided, a spring section that connects the first cylindrical section and the second cylindrical section and has a curved cross-sectional shape, and an imbalance means that generates a bias in the vibration of the translucent body.

2. The vibration device according to claim 1, wherein the unbalance means is a cutout portion in at least one of the first cylindrical portion, the second cylindrical portion, and the spring portion, thereby removing at least a portion of the mass of the vibrating body.

3. A vibration device as claimed in claim 1 or 2, wherein said unbalancing means is a weight that adds mass to a portion of at least one of said first cylindrical portion, said second cylindrical portion and said spring portion.

4. The vibration device according to claim 3, wherein the weight is attached to at least the first cylindrical portion.

5. A vibration device as described in claim 3 or 4, wherein the weight has a semicircular shape that extends halfway around the circumference of the first cylindrical portion.

6. A vibration device according to any one of claims 3 to 5, wherein the specific gravity of the material of said weight is greater than the specific gravity of the material of said vibrating body.

7. A vibration device according to any one of claims 3 to 6, wherein the weight is formed integrally with the vibrating body.

8. A vibration device according to any one of claims 1 to 7, wherein the spring portion has an S-shaped cross section.

9. A vibration device as described in any one of claims 1 to 8, wherein the spring portion has a shape having a portion that bulges out in the radial direction of the first cylindrical portion relative to the first cylindrical portion.

10. A vibration device as described in any one of claims 1 to 9, wherein the second cylindrical portion has a portion whose shape is extended in the radial direction of the second cylindrical portion, and the piezoelectric element is provided in said portion.

11. A vibration device as described in any one of claims 1 to 10, wherein the housing is cylindrical and includes a first portion that holds the translucent body, a second portion that has a larger diameter than the first portion, and a third portion that extends radially from the first portion and connects the first portion and the second portion.

12. The vibration device according to claim 11, wherein the first portion is shaped like a cylinder extended in the axial direction.

13. The vibration device according to claim 11 or 12, wherein the third portion has a weight on a surface facing the vibrating body.

14. An imaging device comprising: the vibration device according to any one of claims 1 to 13; and an imaging element arranged so that the light-transmitting body is in the field of view.

Images